WorldWideScience

Sample records for caulking

  1. Determination of levels of polychlorinated biphenyls (PCBs) present in caulk and window glazing material samples from older buildings

    Science.gov (United States)

    Levels of polychlorinated biphenyls (PCBs) in caulk and window glazing material samples from older buildings were determined, using a method developed for this purpose. This method was evaluated by analyzing a combination of 47 samples of caulk, glazing materials, including quali...

  2. PEMBUATAN SISTEM KONTROL MESIN CAULKING ROD GUIDE OTOMATIS MENGGUNAKAN PLC OMRON CPM1A

    Directory of Open Access Journals (Sweden)

    Syahril Ardi

    2015-02-01

    Full Text Available Kenaikan tingkat produksi shock absorber perusahaan manufaktur membuat proses produksi harus berjalan dengan baik . Pipa proses pemotongan pada mendempul panduan mesin batang memiliki beberapa masalah yang harus diatasi . Untuk mengatasi masalah tersebut kemudian melakukan modifikasi mesin batang mendempul yang secara otomatis dapat mengurangi waktu siklus pada proses mendempul batang dari 4,5 detik per potong sehingga tingkat produksi memotong garis pipa dapat ditingkatkan . Sistem kontrol otomatis mendempul mesin batang panduan ini dirancang untuk menggunakan Programmable Logic Controller (PLC

  3. 7 CFR Exhibit D to Subpart A of... - Thermal Performance Construction Standards

    Science.gov (United States)

    2010-01-01

    ..., gasketed, weatherstripped, or otherwise sealed. Caulking shall be silicone rubber base or butyl rubber base...) Wrap outside corners of wall sheathing with 15 lb. asphalt impregnated building felt before...

  4. Evaluation of resins for provisional restorations.

    Science.gov (United States)

    Burgess, J O; Haveman, C W; Butzin, C

    1992-06-01

    An in vivo study of two resin materials (Barricaid and Caulk Temporary Crown and Bridge Resin) was done to determine the retention, post-operative sensitivity, and fabrication time of provisional restorations made from these materials. Following the placement of these resins in 67 intracoronal cavity preparations of 19 adult patients, a baseline evaluation was made which included a clinical examination and color slides. Twenty-four hours after the temporary restorations were placed, the patients completed evaluations of the post-operative sensitivity experienced. There was no difference in post-operative sensitivity between the teeth restored with Barricaid or Caulk Temporary Crown and Bridge Resin. At the insertion appointment of the final restoration, the interim restoration's success rate was determined. There was no difference between the retention of the two provisional materials. Fabrication time was significantly different with Barricaid restorations requiring less than one-half the fabrication time of the Caulk Temporary Crown and Bridge Resin material. PMID:1388950

  5. Estudio comparativo de tres sistemas adhesivos de grabado total, con diferentes solventes en condiciones de dentina húmeda y seca. (Estudio in Vitro)

    OpenAIRE

    Orellana Jaimes, Noé

    2009-01-01

    El objetivo de esta investigación fue evaluar el comportamiento de los sistemas adhesivos de grabado total XP Bond (Caulk- Dentsply), Prime & Bond NT (Caulk-Dentsply) y Excite (Ivoclar/Vivadent), en las pruebas de monitoreo in Vitro de microtensión pre y post envejecido, micro-filtración, evaluación de la zona de interdifusiòn y simulación de interacción química de elementos básicos. Materiales y Métodos: Con el propósito de valorar el desempeño de los sistemas adhesivos de grabado tot...

  6. 29 CFR 1910.254 - Arc welding and cutting.

    Science.gov (United States)

    2010-07-01

    ... terminal which is intended to be used exclusively for connection to the work is connected to the grounded... is not carried through threaded joints, flanged bolted joints, or caulked joints and that special precautions are used to avoid sparking at connection of the work-lead cable. (iii) Chains, wire ropes,...

  7. 49 CFR 192.275 - Cast iron pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Cast iron pipe. 192.275 Section 192.275... Cast iron pipe. (a) Each caulked bell and spigot joint in cast iron pipe must be sealed with mechanical leak clamps. (b) Each mechanical joint in cast iron pipe must have a gasket made of a...

  8. 7 CFR 3560.103 - Maintaining housing projects.

    Science.gov (United States)

    2010-01-01

    .... Kitchen counter, vanity tops, and back splashes must be properly caulked. (xxvii) Water closets. The... malfunctions of equipment or damages to building systems such as a furnace breakdown or a water leak; and (iii... reflect anticipated needs of the housing project for replacement of capital equipment and systems....

  9. Cytotoxicity of polyurethane dimethacrylate derived from palm oil polyol.

    OpenAIRE

    Abu Kasim, N.H.; AL-Sanabani, F.; Muhamad, S.; Gan, SN

    2010-01-01

    Objective: The aim of this study was to investigate the cytotoxicity effect of polyurethane dimethacrylate monomer derived from palm oil polyol (PUDMA) and 2 experimental composite resins based on these monomer PUDMA- based composites) compared to an experimental Bis-GMA/TEGDMA-based composite and EsthetX flowable composite (Dentsply, Caulk, USA). Methods: The experimental composite resins were prepared by mixing 0.25 and 0.75 by weight camphorquinone and ethyl (4-dimethyl amino) benzoate wit...

  10. Electromagnetic shielding

    International Nuclear Information System (INIS)

    Electromagnetic interference (EMI) shielding materials are well known in the art in forms such as gaskets, caulking compounds, adhesives, coatings and the like for a variety of EMI shielding purposes. In the past, where high shielding performance is necessary, EMI shielding has tended to use silver particles or silver coated copper particles dispersed in a resin binder. More recently, aluminum core silver coated particles have been used to reduce costs while maintaining good electrical and physical properties. (author). 8 figs

  11. INFILTRAÇÃO MARGINAL DE CIMENTOS IONOMÉRICOS MODIFICADOS POR RESINA MICROLEAKAGE OF RESIN-MODIFIED GLASS IONOMER CEMENT

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo CARRARA

    1997-04-01

    Full Text Available Comparou-se a infiltração marginal de dois cimentos restauradores que liberam flúor, o Vitremer/3M e o Variglass/Caulk Dentsply. Cavidades classe II foram confeccionadas nas faces mesiais e distais de pré-molares extraídos. Cada dente recebeu uma restauração de cada material. Procedeu-se, então, a termociclagem em solução de fucsina básica a 0,5%. Nenhum material foi capaz de evitar a infiltração marginal, porém, esta foi menor nas restaurações de Vitremer/3M (pThe microleakage behavior of two hybrid glass ionomer cements used as restorative materials (Variglass/Caulk Dentsply and Vitremer/3M was compared. Separate class II cavities were prepared on the mesial and distal aspects of thirteen extracted premolars. One restoration of each material was placed on every tooth. The cervical margins of the restorations were left one millimeter below the cementoenamel junction. Thermocycling was conduced in a 0.5% basic fuchsin solution. The teeth were washed and sectioned for microleakage analysis under a dissecting microscope. None of the materials tested were able to inhibit dye penetration at the cervical margin. Vitremer/3M was more effective than Variglass/Caulk Dentsply in reducing microleakage.

  12. Best Practices Case Study: David Weekley Homes - Eagle Springs and Waterhaven, Houston, TX

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2011-04-01

    Case study describing David Weekley Homes, Houston Division, has qualified more than 1,240 homes for the DOE Builders Challenge. Advanced framed 2x6 walls with open headers and two-stud corners allow more room for R-20 damp sprayed cellulose wall cavity insulation that is covered with R-5 rigid XPS foam. A radiant barrier cuts heat gain in the R-38 insulated vented attics. Draft stopping at fireplace and duct chases and behind tubs, gluing sheetrock to framing, and extensive caulking make for air-tight homes at 3.0 ACH50.

  13. Primjena ljepljenih (»Maryland«) mostova

    OpenAIRE

    Žgombić, Ante; Braut, Zvonimir; Kraljević, Krešimir; Vukovojac, Stanko

    1988-01-01

    U 50 pacijenata primijenjena je tehnika jetkanja za retenciju mostova. Korištena je slitina Rexillium III (Jenevie Industries, Wallingford Co) i vezivo Comspan (L. D. Caulk Co., M ilfo rd Del.). Terapijski rezultati adhezivnih (jetkanih) mostova ovise o različitim faktorima: pažljive i pravilne indikacije, točnog plana rada, minimalne preparacije zuba nosača, odgovarajuće metode retencije metalnog dijela nadomjestka te vrste veziva i dentalne slitine. Klinička primjena mostova za lijepljenje...

  14. 体育%Sport

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    美国“走钢索的人”百尺高空徒手挑战极限 Walking on "the Mexican Caulk Gun" 近日,在美国加州死亡谷国家公园,探险爱好者Andy Lewis在没有任何安全装备的情况下,赤脚走过一条离地面约百尺高、长达45英尺的松线式索道。

  15. Bronchoalveolar casting using formalin-fixed canine lungs and a low viscosity silicone rubber.

    Science.gov (United States)

    Nettum, J A

    1993-06-01

    A method for creating tough, flexible, bronchoalveolar casts from formalin-fixed canine lung is described. A lung was washed using simple methods and fixed in 10% neutral-buffered formalin. While still wet with formalin, an intact lobe was injected with silicone sealant, Silastic 734 RTV (Room Temperature Vulcanizing), using a caulk gun. Following digestion with protease and corrosion with potassium hydroxide, a bronchoalveolar cast was recovered giving detail as shown using scanning electron microscopy or conveniently seen by stereo light microscopy. This method should be useful for micro-anatomy studies of normal and diseased lungs. PMID:8393308

  16. Thermionic plasma injection for the Lockheed Martin T4 Compact Fusion Reactor experiment

    Science.gov (United States)

    Heinrich, Jonathon

    2015-11-01

    Lockheed Martin's Compact Fusion Reactor (CFR) concept relies on diamagnetic confinement in a magnetically encapsulated linear ring cusp geometry. Plasma injection into cusp field configurations requires careful deliberation. Previous work has shown that axial injection via a plasma gun is capable of achieving high-beta conditions in cusp configurations. We present a pulsed, high power thermionic plasma source and the associated magnetic field topology for plasma injection into the caulked-cusp magnetic field. The resulting plasma fueling and cross-field diffusion is discussed.

  17. DNA Damage, Cell Cycle Arrest, and Apoptosis Induction Caused by Lead in Human Leukemia Cells

    OpenAIRE

    Yedjou, Clement G.; Tchounwou, Hervey M.; Tchounwou, Paul B.

    2015-01-01

    In recent years, the industrial use of lead has been significantly reduced from paints and ceramic products, caulking, and pipe solder. Despite this progress, lead exposure continues to be a significant public health concern. The main goal of this research was to determine the in vitro mechanisms of lead nitrate [Pb(NO3)2] to induce DNA damage, apoptosis, and cell cycle arrest in human leukemia (HL-60) cells. To reach our goal, HL-60 cells were treated with different concentrations of Pb(NO3)...

  18. Evaluation of PCB sources and releases for identifying priorities to reduce PCBs in Washington State (USA).

    Science.gov (United States)

    Davies, Holly; Delistraty, Damon

    2016-02-01

    Polychlorinated biphenyls (PCBs) are ubiquitously distributed in the environment and produce multiple adverse effects in humans and wildlife. As a result, the purpose of our study was to characterize PCB sources in anthropogenic materials and releases to the environment in Washington State (USA) in order to formulate recommendations to reduce PCB exposures. Methods included review of relevant publications (e.g., open literature, industry studies and reports, federal and state government databases), scaling of PCB sources from national or county estimates to state estimates, and communication with industry associations and private and public utilities. Recognizing high associated uncertainty due to incomplete data, we strived to provide central tendency estimates for PCB sources. In terms of mass (high to low), PCB sources include lamp ballasts, caulk, small capacitors, large capacitors, and transformers. For perspective, these sources (200,000-500,000 kg) overwhelm PCBs estimated to reside in the Puget Sound ecosystem (1500 kg). Annual releases of PCBs to the environment (high to low) are attributed to lamp ballasts (400-1500 kg), inadvertent generation by industrial processes (900 kg), caulk (160 kg), small capacitors (3-150 kg), large capacitors (10-80 kg), pigments and dyes (0.02-31 kg), and transformers (expansion of environmental monitoring and public education, and research to identify specific PCB congener profiles in human tissues. PMID:26071980

  19. STS-114 Flight Day 5 Highlights

    Science.gov (United States)

    2005-01-01

    Highlights of Day 5 of the STS-114 Return to Flight mission (Commander Eileen Collins, Pilot James Kelly, Mission Specialists Soichi Noguchi, Stephen Robinson, Andrew Thomas, Wendy Lawrence, and Charles Camarda) include video coverage of an extravehiclular activity (EVA) by Noguchi and Robinson. The other crew members of Discovery are seen on the flight deck and mid-deck helping the astronauts to suit-up. The objectives of the EVA are to test repair techniques on sample tiles in the shuttle's payload bay, to repair electrical equipment for a gyroscope on the International Space Station (ISS), and to install a replacement GPS antenna on the ISS. Noguchi and Robinson use a caulk gun and a putty knife to repair the sample tiles. The video contains several Earth views, including one of Baja California.

  20. Measurement of PCB emissions from building surfaces using a novel portable emission test cell

    DEFF Research Database (Denmark)

    Lyng, Nadja; Gunnarsen, Lars Bo; Andersen, Helle Vibeke;

    2016-01-01

    and there is a need to prioritise remediation measures on different materials. An inexpensive and portable emission test cell was developed to resemble indoor conditions in relation to the area specific ventilation rate. Emissions were measured using the test cell in the laboratory on freshly made PCB......Polychlorinated biphenyls (PCBs) were used in building materials like caulks and paints from 1930 e1970s and in some cases that caused elevated PCB concentrations in the indoor air at levels considered harmful to occupant health. PCBs are semivolatile organic compounds and capable of spreading from...... the original source to adjacent materials, indoor air and via adsorption from the air to indoor surfaces, causing secondary contaminations. Remediation of buildings with unsatisfactory indoor air concentrations is a complex and difficult task due to the secondary contamination of building materials...

  1. Passive solar construction handbook

    Energy Technology Data Exchange (ETDEWEB)

    Levy, E.; Evans, D.; Gardstein, C.

    1981-08-01

    Many of the basic elements of passive solar design are reviewed. The unique design constraints presented in passive homes are introduced and many of the salient issues influencing design decisions are described briefly. Passive solar construction is described for each passive system type: direct gain, thermal storage wall, attached sunspace, thermal storage roof, and convective loop. For each system type, important design and construction issues are discussed and case studies illustrating designed and built examples of the system type are presented. Construction details are given and construction and thermal performance information is given for the materials used in collector components, storage components, and control components. Included are glazing materials, framing systems, caulking and sealants, concrete masonry, concrete, brick, shading, reflectors, and insulators. The Load Collector Ratio method for estimating passive system performance is appended, and other analysis methods are briefly summarized. (LEW)

  2. Influence of dentin contamination by temporary cements on the bond strength of adhesive systems

    Directory of Open Access Journals (Sweden)

    Josimeri Hebling

    2009-01-01

    Full Text Available Objective: The aim of this study was to assess the bond strength of adhesive systems to dentin contaminated by temporary cements with or without eugenol. Method: Flat dentin surfaces were obtained from twenty-four human third molars. With exception of the control group (n=8, the surfaces were covered with Interim Restorative Material (Caulk Dentsplay, Milford, DE, USA or Cavit (3M ESPE, St. Paul, MN, USA and kept in an oven at 37oC for seven days. After removing the cements, the adhesive systems Adper Single Bond (3M ESPE, St. Paul, MN, USA or Clearfil SE Bond (Kuraray Co. Ltd., Osaka, Japan were applied in accordance with the manufacturers’ recommendations, and then the crowns were constructed in of resin composite. The teeth were sectioned into specimens with a cross-sectional bond area of 0.81mm2, which were sub mitted to microtensile testing in a mechanical test machine at an actuator speed of 0.5mm/min. The data were analyzed by t- and ANOVA tests, complemented by Tukey tests (α=0.05. Results: For Adper Single Bond (3M ESPE, St. Paul, MN, USA, bond strength did not differ statistically (p>0.05 for all the experimental conditions. For Clearfil SE Bond (Kuraray Co. Ltd., Osaka, Japan, only the Interim Restorative Material (Caulk Dentsplay, Milford, DE, USA Group showed significantly lower bond strength (30.1±13.8 MPa in comparison with the other groups; control (38.9±13.5 MPa and Cavit (3M ESPE, St. Paul, MN, USA (42.1±11.0 MPa, which showed no significant difference between them.Conclusion: It was concluded that the previous covering of dentin with temporary cement containing eugenol had a deleterious effect on the adhesive performance of the self-etching system only.

  3. STUDI ALTERNATIF PENGGUNAAN SERAT KELAPA (COCOFIBER UNTUK KEKEDAPAN SAMBUNGAN KULIT PADA KAPAL KAYU TRADISIONAL DENGAN PENGUJIAN HIDROSTATIS

    Directory of Open Access Journals (Sweden)

    Parlindungan Manik

    2012-03-01

    Full Text Available This study explains about the use of coco fiber as an alternative material in ship impermeability process. At impermeability process of traditional wooden ship is applied by bark gelam or by twisted jute fiber as component of caulk for impermeability of junction bark of ship, where at this caulker still leak on bark of wooden ship.Impermeability technology by using bark gelam or by twisted jute fiber which was caulked at junction bark of ship. There is still leak on bark of ship, so this research was applied lay-up coco-fiber with resin as alternative material to overcome leak problem bark of wooden ship.The methodological study was started with make specimen test, after that the putty process with lay up coco fiber with resin and catalyst, and than doing hydrostatic testing. Finally, we analyze the result of research can be used in putty of wooden ship.The result of research, it was concluded that in general pressure maximum each bevel specimen which could endure burden on the bark of ship i.e. : for board joint design 150 is 99,67 lbf/in2 , for board joint design 300 is 91,67 lbf/in2 and for board joint design 450 is 66 lbf/in2. With the result in general pressure maximum above, the bark can receive burden at draft (T i.e. : for bevel 150 is 68,38 meter (m, for bevel 300 is 62,86 meter (m, and for bevel 450 is 45,16 meter (m.The Putty technology used variety bevel specimen i.e. bevel 150, 300 end 450 could be applicated for impermeability of junction bark of traditioanl vessel

  4. 掺加粉煤灰和矿粉对嵌缝加固胶泥性能的试验研究%Experimental research on admixture of fly ash and mineral powder on the properties of reinforced cement sealing

    Institute of Scientific and Technical Information of China (English)

    胡向阳; 何忠茂; 何廷树

    2014-01-01

    In order to study the fly ash and mineral powder on the properties of cement sealing,Experimental research on different age, different content of fly ash and mineral powder to cement caulking compressive strength.And use the SEM ,mercury injection apparatus to analyze its microcosmic mechanism.Experiment shows that the fly ash and mineral powder after sealing isometric substitute cement in the cement caulking, the flexural compressive strength with the increase of the dosage of admixture showed a trend of decline.Double mixing fly ash mineral powder group of microscopic test results show that the most probable aperture smaller than single mixing fly ash mineral group,and double mixing group later hydration products is rich,is conducive to the growth of the late strength.%为了研究粉煤灰、矿粉对嵌缝胶泥性能的影响,对粉煤灰、矿粉不同龄期不同掺量的嵌缝胶泥进行抗折、抗压强度试验。并使用SEM、压汞仪分析其微观机理。试验表明:粉煤灰、矿粉在等量取代嵌缝胶泥中的水泥之后,其抗折抗压强度随掺合料掺量的增加呈现下降趋势。双掺粉煤灰矿粉组的微观测试结果显示其最可几孔径小于单掺粉煤灰矿粉组,且双掺组后期的水化产物丰富,有利于后期强度的增长。

  5. The effect of one-step and multi-step polishing systems on surface texture of two different resin composites

    Directory of Open Access Journals (Sweden)

    Bashetty Kusum

    2010-01-01

    Full Text Available Objective: The purpose of this in-vitro study was to evaluate the surface roughness of two direct resin composites polished with one-step and multi-step polishing systems. Materials and Methods: The resin composites examined in this study include minifill-hybrid composite Esthet-X (DENTSPLY/Caulk, Milford, DE, USA and packable composite Solitaire II (Heraeus Kulzer, Inc., Southbend. A total of 42 discs (10 3 2 mm, 21 specimens of each restorative material were fabricated. Seven specimens per composite group received no polishing treatment and served as control. For each composite group, the specimens were randomly divided into two polishing systems: One-step PoGo (Dentsply/Caulk, Milford, DE, USA and multi-step Super Snap (Shofu, Inc. Kyoto, Japan. Polishing systems were applied according to the manufacturer′s instructions after being ground wet with 1200 grit silicon carbide paper. The surface roughness values were determined using a profilometer. Results: Data was subjected to student′s t test at a significance level of 0.05. The smoothest surfaces were achieved under Mylar strips in both the composite groups. Mean Ra values ranged from 0.09 to 0.3 mm for Esthet-X group and from 0.18 to 0.3 mm for Solitaire II with different polishing systems. The ranking of the order of surface roughness on the basis of the type of composite was as follows: Esthet-X , Solitaire II for PoGo system and Esthet-X 5 Solitaire II for Super Snap; and the ranking for the polishing system was: PoGo , Super Snap (P # 0.05. Conclusion: The one-step polishing system (PoGo produced better surface quality in terms of roughness than the multi-step system (Super Snap for minifill-hybrid composite (Esthet-X, and it was equivalent to Super Snap for packable composites (Solitaire II. Minifill-hybrid presented a better surface finish than Solitaire II when PoGo polishing system was used. No significant difference was present in surface roughness between both

  6. Investigation of infiltration and indoor air quality

    International Nuclear Information System (INIS)

    A multitask study was performed in the State of New York to provide information for guiding home energy conservation programs while maintaining acceptable indoor air quality. During the study, the statistical distribution of radon concentrations inside 2,400 homes was determined. The relationships among radon levels, house characteristics, and sources were also investigated. The direct impact that two specific air infiltration reduction measures--caulking and weatherstripping of windows and doors, and installation of storm windows and storm doors--have on house air leakage was investigated in 60 homes. The effect of house age on the impact of weatherization was also evaluated. Indoor and outdoor measurements of NO2, CO, SO2, and respirable suspended particulates (RSP) were made for 400 homes to determine the effect of combustion sources on indoor air quality and to characterize the statistical distribution of the concentrations. Finally, the combustion source data were combined with the information on air infiltration reduction measures to estimate the potential impact of these measures on indoor air quality

  7. Energy use test facility: CAC-DOE solar air heater test report

    Science.gov (United States)

    1981-11-01

    The solar air heater testing demonstrated an attractive application for residential space heating, especially appealing to the do-it-yourself market. Simple improvements in construction, such as caulking of the glazing, could increase collector performance at little cost. The operating cost of the fan was insignificant, being less than $0.05/week. Tested in its as-shipped configuration at 96.1 cfm (3 cfm/ft (2)), the useful energy delivered averaged 20,000 Btu/day for six days in December. The electrical consumption of the fan was approximately 1 kWh. Doubling the flowrate did not increase collector performance appreciably. A TRNSYS computer simulation model for this solar air heater design was validated by comparing the measured test data on Jaunary 4, 1981 with calculated values. TRNSYS predicted that measured collector outlet temperatures within +- 1.20F and the energy delivered within +- 3%. The excellent agreement was obtained by adjusting the collector loss coefficient to an unrealistically low value; therefore, a parametric study is recommended to determine the model sensitivity to varying different parameters. A first-order collector efficiency curve was derived from the TRNSYS simulations which compared well with the curve defined by the clear-day measured data.

  8. Analysis on the Covering Technique of Medium and Large Coach Outer Skin%大中型客车外蒙皮覆盖技术分析

    Institute of Scientific and Technical Information of China (English)

    陈伟

    2013-01-01

    国内大客车的外蒙皮一般采用玻璃钢或冲压件,蒙皮之间的接缝都是采用填充玻璃钢树脂或刮腻子来解决。这种填缝结构容易开裂、漏水,而且在生产过程中粉尘污染比较大。国外的客车普遍都采用冲压件蒙皮,接缝处采用填缝胶来处理,能很好地避免这些问题。%The outer skin of large coaches is domestically made of fiberglass or stamping parts, the seam between outer skins is filled with fiberglass or putty powder. This structure is easy to crack and leaking,and the dust pollution in the production process is relatively remarkable. The coach outer skin abroad is widely made of stamping parts and the seam is filled with caulking glue, this structure can be very helpful to avoid above problems.

  9. Indoor air quality issues related to the acquisition of conservation in commercial buildings

    Energy Technology Data Exchange (ETDEWEB)

    Baechler, M.C.; Hadley, D.L.; Marseille, T.J.

    1990-09-01

    The quality of indoor air in commercial buildings is dependent on the complex interaction between sources of indoor pollutants, environmental factors within buildings such as temperature and humidity, the removal of air pollutants by air-cleaning devices, and the removal and dilution of pollutants from outside air. To the extent that energy conservation measures (ECMs) may affect a number of these factors, the relationship between ECMs and indoor air quality is difficult to predict. Energy conservation measures may affect pollutant levels in other ways. Conservation measures, such as caulking and insulation, may introduce sources of indoor pollutants. Measures that reduce mechanical ventilation may allow pollutants to build up inside structures. Finally, heating, ventilation, and air-conditioning (HVAC) systems may provide surface areas for the growth of biogenic agents, or may encourage the dissemination of pollutants throughout a building. Information about indoor air quality and ventilation in both new and existing commercial buildings is summarized in this report. Sick building syndrome and specific pollutants are discussed, as are broader issues such as ventilation, general mitigation techniques, and the interaction between energy conservation activities and indoor air quality. Pacific Northwest Laboratory (PNL) prepared this review to aid the Bonneville Power Administration (Bonneville) in its assessment of potential environmental effects resulting from conservation activities in commercial buildings. 76 refs., 2 figs., 19 tabs.

  10. An investigation of infiltration and indoor air quality

    Energy Technology Data Exchange (ETDEWEB)

    1990-09-01

    A multitask study was performed in the State of New York to provide information for guiding home energy conservation programs while maintaining acceptable indoor air quality. During this study, the statistical distribution of radon concentrations inside 2400 homes was determined. The relationships among radon levels, house characteristics, and sources were also investigated. The direct impact that two specific air infiltration reduction measures -- caulking and weatherstripping of windows and doors, and installation of storm windows and storm doors -- have on house air leakage was investigated in 60 homes. The effect of house age on the impact of weatherization was also evaluated. Indoor and outdoor measurements of NO{sub 2}, CO, SO{sub 2}, and respirable suspended particulates (RSP) were made for 400 homes to determine the effect of combustion sources on indoor air quality and to characterize the statistical distribution of the concentrations. Finally, the combustion source data were combined with the information on air infiltration reduction measures to estimate the potential impact of these measures on indoor air quality. 87 tabs.

  11. Polymerization shrinkage evaluation of three packable composite resins using a gas pycnometer

    Directory of Open Access Journals (Sweden)

    Amore Ricardo

    2003-01-01

    Full Text Available Modern restorative dentistry has been playing an outstanding role lately since composite resins, allied to adhesive systems, have been widely applied on anterior and posterior teeth restorations. The evolution of composite resins has mostly been verified due to the improvement of their aesthetic behavior and the increase in their compressive and abrasive strengths. In spite of these developments, the polymerization shrinkage inherent to the material has been a major deficiency that, so far, has been impossible to avoid. Using a gas pycnometry, this research investigated the polymerization shrinkage of three packable composite resins: Filtek P60 (3M, Prodigy Condensable (Kerr, and SureFil (Dentsply/Caulk, varying the distance from the light source to the surface of the resins (2 mm or 10 mm. The pycnometer Accupyc 1330 (Micromeritics, USA precisely records helium displacement, allowing fast and reliable measurements of the volume of composite resin immediately before and after polymerization, without interference of temperature or humidity. Results were not found to be statistically different for the three tested resins, either for 2 mm or 10 mm-distance from the light source to the composite surface.

  12. Preparation and using phantom lesions to practice fine needle aspiration biopsies.

    Science.gov (United States)

    Shidham, Vinod B; Varsegi, George M; D'Amore, Krista; Shidham, Anjani

    2009-01-01

    Currently, health workers including residents and fellows do not have a suitable phantom model to practice the fine- needle aspiration biopsy (FNAB) procedure. In the past, we standardized a model consisting of latex glove containing fresh cattle liver for practicing FNAB. However, this model is difficult to organize and prepare on short notice, with the procurement of fresh cattle liver being the most challenging aspect. Handling of liver with contamination-related problems is also a significant draw back. In addition, the glove material leaks after a few needle passes, with resulting mess. We have established a novel simple method of embedding a small piece of sausage or banana in a commercially available silicone rubber caulk. This model allows the retention of vacuum seal and aspiration of material from the embedded specimen, resembling an actual FNAB procedure on clinical mass lesions. The aspirated material in the needle hub can be processed similar to the specimens procured during an actual FNAB procedure, facilitating additional proficiency in smear preparation and staining. PMID:19893483

  13. Complexation-Coprecipitation Synthesis and Characterization of Neodymium and Antimony Doped SnO2 Conductive Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Nd and Sb doped SnO2 conductive nanoparticles were prepared by the complexation-coprecipitation method with Sn, Sb2O3 and Nd2O3 as the raw materials. Thermal behavior, crystal phase, and structure of the prepared conductive nanoparticles were characterized by TG/DSC/DTG, FTIR, XRD and TEM techniques, respectively. The resistivity of the prepared conductive nanoparticles was 0.12 Ω·cm. TG/DSC/DTG curves show that the precursors lose weight completely before 750 ℃. FTIR spectrum shows that the vibration peaks are wide peaks in 731~617 cm-1, and the Nd and Sb doped SnO2 conductive nanoparticles have intense absorption in 4000~2000 cm-1. Nd and Sb doped SnO2 have a structure of tetragonal rutile, and complex doping is achieved well by complexation-coprecipitation method and is recognized as replacement doping or caulking doping. TME shows that the particles are weakly agglomerated, and the size of the particles calcined at 1000 ℃ ranges about 10 nm to 30 nm.

  14. Long term durability and performance of radon mitigation subslab depressurization systems

    International Nuclear Information System (INIS)

    Subslab depressurization (SSD) systems have become the most popular radon mitigation technique used by professional mitigators. Readily available supplies and equipment from other trades are commonly utilized in the installation of these systems. What is not currently known is the long-term performance of some of the caulks or sealants and the mechanical devices such as fans or controls. The operating environment for the fans is often different from that for which they were designed. Specifically, this involves studying whether the fans are still operating as installed, whether there has been an increase or decrease in the radon levels after several years of operation, and whether the homeowners are operating the systems the way the systems were originally designed. To answer these questions, the authors have tested eight of the Piedmont Study homes as well as homes in which post-mitigation measurements done by New Jersey Dept. of Environmental Protection have shown readings that were above the U.S. EPA guideline of 4 pCi/L. This paper presents the findings of this research and discusses some of the durability aspects of SSD systems and their interaction with the house substructure

  15. Project report: Tritiated oil repackaging highlighting the ISMS process. Historical radioactive and mixed waste disposal request validation and waste disposal project

    Energy Technology Data Exchange (ETDEWEB)

    Schriner, J.A. [Automated Solutions of Albuquerque, Inc., NM (United States)

    1998-08-01

    The Integrated Safety Management System (ISMS) was established to define a framework for the essential functions of managing work safely. There are five Safety Management Functions in the model of the ISMS process: (1) work planning, (2) hazards analysis, (3) hazards control, (4) work performance, and (5) feedback and improve. Recent activities at the Radioactive and Mixed Waste Management Facility underscored the importance and effectiveness of integrating the ISMS process to safely manage high-hazard work with a minimum of personnel in a timely and efficient manner. This report describes how project personnel followed the framework of the ISMS process to successfully repackage tritium-contaminated oils. The main objective was to open the boxes without allowing the gaseous tritium oxide, which had built up inside the boxes, to release into the sorting room. The boxes would be vented out the building stack until tritium concentration levels were acceptable. The carboys would be repackaged into 30-gallon drums and caulked shut. Sealing the drums would decrease the tritium off-gassing into the RMWMF.

  16. Development of electrical cable penetration for secondary containment vessel of BWR type nuclear power plants

    International Nuclear Information System (INIS)

    The penetration holes in the walls and floors of the secondary containment vessel of the nuclear power plants must be air-tight, shielded against the radiation, and fire-resistant. At present, the penetration holes are air-tightened with iron plates and sealing material after the cables are laid. However, installation of a number of cables and its sealing work now pose a serious problem in nuclear power plant construction in relation to the installation of reactor system components. The authors have recently developed a method for electric wall penetration in an attempt to solve this problem. This method is provided with prefabricated cable portions for wall penetration, reducing field work, saving labor in wiring work through use of multicore cables, and increasing the reliability of the sealing and caulking work. This wall penetration consists of an iron sleeves to be embedded into the wall, a header-plate, and an assembly of modules in which a specified number of insulated conductors are set up, and furthermore termination boxes are installed on both ends of the penetration holes. This paper deals with the design standard and construction of the wall penetration and the results of tests which were performed under various environmental conditions, which has shown excellent properties, such as sealing quality and electric characteristics, of the wall penetration. (author)

  17. Radon penetration of concrete slab cracks, joints, pipe penetrations, and sealants.

    Science.gov (United States)

    Nielson, K K; Rogers, V C; Holt, R B; Pugh, T D; Grondzik, W A; de Meijer, R J

    1997-10-01

    Radon movement through 12 test slabs with different cracks, pipe penetrations, cold joints, masonry blocks, sealants, and tensile stresses characterized the importance of these anomalous structural domains. Diffusive and advective radon transport were measured with steady-state air pressure differences controlled throughout the deltaP = 0 to 60 Pa range. Diffusion coefficients (deltaP = 0) initially averaged 6.5 x 10(-8) m2 s(-1) among nine slabs with only 8% standard deviation, but increased due to drying by 0.16% per day over a 2-y period to an average of 2.0 x 10(-7) m2 s(-1). An asphalt coating reduced diffusion sixfold but an acrylic surface sealant had no effect. Diffusion was 42 times higher in solid masonry blocks than in concrete and was not affected by small cracks. Advective transport (deltaP pipe penetrations, and caulked gaps, but was significant for cracks, disturbed pipe penetrations, cold joints, masonry blocks, and concrete under tensile stress. Crack areas calculated to be as small as 10(-7) m2 significantly increased radon advection. Algebraic expressions predict air velocity and effective crack width from enhanced radon transport and air pressures. Masonry blocks, open cracks, and slab cold joints enhance radon penetration but stressed slabs, undisturbed pipe penetrations, and sealed cracks may not. PMID:9314229

  18. Modular glovebox connector and associated good practices for control of radioactive and chemically toxic materials

    International Nuclear Information System (INIS)

    Design and associated good practices are described for a modular glovebox connector to improve control of radioactive and chemically toxic materials. The connector consists of an anodized aluminum circular port with a mating spacer, gaskets, and retaining rings for joining two parallel ends of commercially available or custom-manufactured glovebox enclosures. Use of the connector allows multiple gloveboxes to be quickly assembled or reconfigured in functional units. Connector dimensions can be scaled to meet operational requirements for access between gloveboxes. Options for construction materials are discussed, along with recommendations for installation of the connector in new or retrofitted systems. Associated good practices include application of surface coatings and caulking, use of disposable glovebags, and proper selection and protection of gasket and glove materials. Use of the connector at an inhalation toxicology research facility has reduced the time and expense required to reconfigure equipment for changing operational requirements, the dispersion of contamination during reconfigurations, and the need for decommissioning and disposal of contaminated enclosures

  19. The effect of spiked boots on logger safety, productivity and workload.

    Science.gov (United States)

    Kirk, P; Parker, R

    1994-04-01

    Analysis of 1657 lost-time logging accidents in the New Zealand logging industry (1985-1991) indicates that 17.5% were as a result of slips, trips and falls and a total of 2870 days were lost. Most (56%) of these slipping, tripping and falling accidents occurred in the felling and delimbing phase of the logging operation, where 37% of the workforce are employed. In an attempt to reduce the number of slipping injuries to loggers employed in felling and delimbing, a study of the effectiveness of spike-soled (caulk) boots was undertaken. Four loggers were intensively observed at work, by continuous time-study methods, while wearing their conventional rubber-soled boots and then spike-soled boots. The number of slips, work methods used, physiological workload and productivity were compared for loggers wearing the two footwear types. Results indicated that spike-soled boots were associated with a significant reduction in the frequency of slips and had no adverse effect on work methods, physiological workload or productivity. Spike-soled boots are now being promoted for use by loggers in New Zealand as a simple method to reduce slipping, tripping and falling accidents. PMID:15676957

  20. Mechanical Properties of Surface-Charged Poly(Methyl Methacrylate as Denture Resins

    Directory of Open Access Journals (Sweden)

    Sang E. Park

    2009-01-01

    Full Text Available The aim of this study was to examine the mechanical properties of a new surface-modified denture resin for its suitability as denture base material. This experimental resin is made by copolymerization of methacrylic acid (MA to poly(methyl methacrylate (PMMA to produce a negative charge. Four experimental groups consisted of Orthodontic Dental Resin (DENTSPLY Caulk as a control and three groups of modified PMMA (mPMMA produced at differing ratios of methacrylic acid (5 : 95, 10 : 90, and 20 : 80 MA : MMA. A 3-point flexural test using the Instron Universal Testing Machine (Instron Corp. measured force-deflection curves and a complete stress versus strain history to calculate the transverse strength, transverse deflection, flexural strength, and modulus of elasticity. Analysis of Variance and Scheffe Post-test were performed on the data. Resins with increased methacrylic acid content exhibited lower strength values for the measured physical properties. The most significant decrease occurred as the methacrylic acid content was increased to 20% mPMMA. No significant differences at P<.05 were found in all parameters tested between the Control and 5% mPMMA.

  1. Catchment science on a shoestring -- Luddites, labor, and a little high-tech

    Science.gov (United States)

    Shanley, J. B.; Denner, J. C.; Clark, S. F.; Chalmers, A.; Smith, T. E.; Sebestyen, S. D.; McGlynn, B.; Hjerdt, K. N.; McDonnell, J. J.

    2004-05-01

    At Sleepers River Research Watershed in northeastern Vermont, the USGS has operated a long-term global change hydrology site with a limited equipment budget for more than 12 years. Most of the research takes place at a remote 41-ha catchment without A/C power, 15-minutes walk from the nearest road. The overall approach of the project is the combined use of hydrologic, chemical, and isotopic measurements to understand hydrologic flow paths and biogeochemical evolution of waters. Measurements and water samples are taken at various nodes in the system. Some of our cost-effective ways to conduct these measurements include: (1) a horse to pull a drill rig for installing wells in the catchment; (2) small stream V-notch weirs fashioned from plywood and plexiglas (12 years and going strong); (3) a knocking pole penetrometer to determine soil depths and infer soil properties; (4) solar panels to charge batteries; (5) frost depth measurements using methylene blue solution in flexible tubing suspended within PVC housing (6) two versions of snowmelt lysimeters constructed of PVC pipe and plexiglas (both silicone caulk and duct tape were used on the latter); (7) arrays of washing machine peepers, which are small inexpensive on/off float sensors mounted at land surface to determine surface saturation (recorded with a datalogger). These creative low-cost solutions to "getting the job done" have helped to keep this long-term site operating during budget shortfalls.

  2. Kissing Bug (Triatoma spp.) Intrusion into Homes: Troublesome Bites and Domiciliation.

    Science.gov (United States)

    Klotz, Stephen A; Shirazi, F Mazda; Boesen, Keith; Beatty, Norman L; Dorn, Patricia L; Smith, Shannon; Schmidt, Justin O

    2016-01-01

    Kissing bugs (Triatoma spp.) frequently enter homes and bite human and pet occupants. Bites may lead to severe allergic reactions and, in some cases, death. Kissing bugs are also vectors of Trypanosoma cruzi, the cause of Chagas disease. In general, modern houses in the United States are not conducive to domiciliation of kissing bugs (bugs living out their entire life within the home with the presence of eggs, nymphs, adults, and exuviae). Construction features such as concrete foundations, solid walls and ceilings, window screens, tight thresholds for doors and windows, and other measures impede bug entry into homes, and air conditioning reduces the need for open doors and windows. Where Chagas disease is endemic in Mexico and Central and South America, homes often have thatch roofs, adobe walls, and open doors and windows. We investigated numerous instances of kissing bug intrusions into homes in Southern Arizona, California, and Louisiana and documented the reactions to kissing bug bites. Our work confirms the importance of modern home construction in limiting kissing bug intrusions. Older homes, especially those lacking modern screening, caulking, and weather stripping to reduce air leakage, may be subject to kissing bug intrusions and domiciliation. We describe a community in Southern Arizona where domiciliation of homes by Triatoma recurva is common. We also provide recent data regarding kissing bug bites and allergic reactions to the bites. PMID:27042091

  3. One-bottle adhesives: in vitro analysis of solvent volatilization and sealing ability Adesivos de frasco único: análise in vitro da volatilização do solvente e do selamento marginal

    Directory of Open Access Journals (Sweden)

    Fábio Garcia Lima

    2005-12-01

    Full Text Available The aim of this study was to compare the solvent volatilization rate and evaluate the sealing ability of different one-bottle adhesives that were in constant clinical use - an ethanol/water-based adhesive (Single Bond, 3M/ESPE - SB and an acetone-based adhesive (Prime & Bond 2.1, Dentsply/Caulk - PB. Nine bottles of each agent were collected from the clinics of a dental school, and new ones were used as controls. The weight of all bottles and of empty bottles was determined using an analytical balance. A drop of each solution was dispensed onto the balance, taking its initial weight (IW and, after 10 min, its final weight (FW. The IW/FW ratio was used to determine the solvent’s volatilization rate. The bottles with the highest evaporation levels (SB Control and PB Control and with the lowest evaporation levels (SB Test and PB Test of each agent were applied in Class V restorations with margins in dentin. Specimens were thermocycled and immersed in a 0.5% basic fuchsin solution. Dye penetration was evaluated under magnification and the data were submitted to the Kruskal-Wallis test. Solvent volatilization was faster for the acetone-based adhesive. IW/FW ratios ranged from 1.239 to 1.515 for SB, and from 3.488 to 6.476 for PB. The PB-Control and SB-Control groups exhibited similar microleakage patterns. The highest dye penetration scores were found for the PB-Test group (p O objetivo deste estudo foi comparar a taxa de volatilização do solvente e a capacidade de selamento de diferentes adesivos de frasco único que estavam em constante uso clínico - um à base de etanol/água (Single Bond, 3M/ESPE e um à base de acetona (Prime & Bond 2.1, Dentsply/Caulk. Nove frascos de cada agente foram coletados das clínicas da faculdade e outros novos foram utilizados como controle. Os pesos de todos os frascos e de frascos vazios foram determinados em uma balança analítica. Uma gota de cada solução foi dispensada na balança, tomando-se seu peso

  4. Remediation Technologies Eliminate Contaminants

    Science.gov (United States)

    2012-01-01

    groundwater tainted by chlorinated solvents once used to clean rocket engine components. The award-winning innovation (Spinoff 2010) is now NASA s most licensed technology to date. PCBs in paint presented a new challenge. Removing the launch stand for recycling proved a difficult operation; the toxic paint had to be fully stripped from the steel structure, a lengthy and costly process that required the stripped paint to be treated before disposal. Noting the lack of efficient, environmentally friendly options for dealing with PCBs, Quinn and her colleagues developed the Activated Metal Treatment System (AMTS). AMTS is a paste consisting of a solvent solution containing microscale particles of activated zero-valent metal. When applied to a painted surface, the paste extracts and degrades the PCBs into benign byproducts while leaving the paint on the structure. This provides a superior alternative to other methods for PCB remediation, such as stripping the paint or incinerating the structure, which prevents reuse and can release volatized PCBs into the air. Since its development, AMTS has proven to be a valuable solution for removing PCBs from paint, caulking, and various insulation and filler materials in older buildings, naval ships, and former munitions facilities where the presence of PCBs interferes with methods for removing trace explosive materials. Miles of potentially toxic caulking join sections of runways at airports. Any of these materials installed before 1979 potentially contain PCBs, Quinn says. "This is not just a NASA problem," she says. "It s a global problem."

  5. Endocrine disrupting chemicals in indoor and outdoor air

    Science.gov (United States)

    Rudel, Ruthann A.; Perovich, Laura J.

    The past 50 years have seen rapid development of new building materials, furnishings, and consumer products and a corresponding explosion in new chemicals in the built environment. While exposure levels are largely undocumented, they are likely to have increased as a wider variety of chemicals came into use, people began spending more time indoors, and air exchange rates decreased to improve energy efficiency. As a result of weak regulatory requirements for chemical safety testing, only limited toxicity data are available for these chemicals. Over the past 15 years, some chemical classes commonly used in building materials, furnishings, and consumer products have been shown to be endocrine disrupting chemicals - that is they interfere with the action of endogenous hormones. These include PCBs, used in electrical equipment, caulking, paints and surface coatings; chlorinated and brominated flame retardants, used in electronics, furniture, and textiles; pesticides, used to control insects, weeds, and other pests in agriculture, lawn maintenance, and the built environment; phthalates, used in vinyl, plastics, fragrances, and other products; alkylphenols, used in detergents, pesticide formulations, and polystyrene plastics; and parabens, used to preserve products like lotions and sunscreens. This paper summarizes reported indoor and outdoor air concentrations, chemical use and sources, and toxicity data for each of these chemical classes. While industrial and transportation-related pollutants have been shown to migrate indoors from outdoor sources, it is expected that indoor sources predominate for these consumer product chemicals; and some studies have identified indoor sources as the predominant factor influencing outdoor ambient air concentrations in densely populated areas. Mechanisms of action, adverse effects, and dose-response relationships for many of these chemicals are poorly understood and no systematic screening of common chemicals for endocrine disrupting

  6. Collector sealants and breathing. Mid-term report, September 25, 1978-May 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Mendelsohn, M. A.; Yeoman, F. A.; Luck, R. M.; Navish, Jr, F. W.; Meier, J. F.

    1978-01-01

    The objectives of this program are: (1) to investigate the pertinent properties of a variety of possible sealants for solar collectors and identify the most promising candidates and to study the effect of breathing in flat-plate, thermal solar collector units. The study involves two types of sealants, Class PS which includes performed seals or gaskets and Class SC which includes sealing compounds or caulks. It is the intent of the study to obtain data regarding initial properties of candidate elastomers from manufacturers and from the technical literature and to use those sources to provide data pertaining to endurance of these materials under environmental service conditions. Where necessary, these data are being augmented by experimental measurements. Environmental stresses to be evaluated by these measuremets include elevated temperatures, moisture, ultraviolet light, ozone and oxygen, and fungus. The second major area of the work involves a study of the effects of materials used and design on the durability of solar collectors. Factors such as design, fabrication, materials of construction, seals and sealing techniques and absorber plate coatings were observed on actual field units removed from service. Such phenomena as leakage, corrosion and formation of deposits on glazing and absorber plate were noted. An evaluation of the properties of several desiccants is being made in order to provide means to mitigate the deleterious effects of water on collector life.Absorbents for organic degradation products of sealants are also being investigated in order to protect the glazing and absorber plate from deposited coatings. Since adsorbents and desiccants in general tend to take up both waer and organic decomposition products, relative affinities of a number of these agents for water and for organic compounds are being determined.

  7. Formula for the Removal and Remediation of Polychlorinated Biphenyls in Painted Structures

    Science.gov (United States)

    Quinn, Jacqueline; Loftin, Kathleen; Geiger, Cherie

    2010-01-01

    An activated metal treatment system (AMTS) removes and destroys polychlorinated biphenyls (PCBs) found in painted structures or within the binding or caulking material on structures. It may be applied using a "paint-on and wipe-off" process that leaves the structure PCB-free and virtually unaltered in physical form. AMTS is used in conjunction with a solvent solution capable of donating hydrogen atoms. AMTS as a treatment technology has two functions: first, to extract PCBs from the material, and second, to degrade the extracted PCBs. The process for removing PCBs from structures is accomplished as an independent step to the degradation process. The goal is to extract the PCBs out of the paint, without destroying the paint, and to partition the PCBs into an environmentally friendly solvent. The research to date indicates this can be accomplished within the first 24 hours of AMTS contact with the paint. PCBs are extremely hydrophobic and prefer to be in the AMTS over the hardened paint or binder material. The solvent selected must be used to open, but not to destroy, the paint s polymeric lattice structure, allowing pathways for PCB movement out of the paint and into the solvent. A number of solvent systems were tested and are available for use within the AMTS. The second process of the AMTS is the degradation or dehalogenation of the PCBs. The solvent selection for this process is limited to solvents that are capable of donating a hydrogen atom to the PCB structure. Additional AMTS formulation properties that must be addressed for each site-specific application include viscosity and stability. The AMTS must be thick enough to remain where it is applied. Several thickening agents have been tested. Adding a stabilizing agent ensures that the AMTS will not evaporate and leave unprotected, activated metal exposed. During AMTS formulation testing, a number of reagents were evaluated to ensure the rate of dehalogenation was not inhibited by its addition to the system.

  8. PCB-containing wood floor finish is a likely source of elevated PCBs in residents' blood, household air and dust: a case study of exposure

    Directory of Open Access Journals (Sweden)

    Seryak Liesel M

    2008-01-01

    Full Text Available Abstract Background Polychlorinated biphenyls (PCBs are persistent pollutants identified worldwide as human blood and breast milk contaminants. Because they bioaccumulate, consumption of meat, fish, and dairy products predicts human blood concentrations. PCBs were also used widely in building materials, including caulks and paints, but few studies have evaluated the contribution of these exposures to body burden. Methods In an earlier study, we detected PCBs in indoor air in 31% of 120 homes on Cape Cod, MA. Two of the homes had much higher concentrations than the rest, so we retested to verify the initial finding, evaluate blood PCB concentrations of residents, and identify the PCB source. Results Air and dust concentrations remained elevated over 5 years between initial and follow-up sampling. Blood serum concentrations of PCBs in residents of the homes were generally elevated above the 95th percentile of a representative sample of the US population. Serum concentrations in residents and air and dust concentrations were especially high in a home where a resident reported use of PCB-containing floor finish in the past, and where the floor of one room was sanded and refinished just prior to sample collection. Conclusion This case-study suggests that PCB residues in homes may be more significant contributors to overall exposure than diet for some people, and that use of a commercially-available PCB-containing wood floor finish in residences during the 1950s and 1960s is an overlooked but potentially important source of current PCB exposure in the general population.

  9. Engineering Application of Lightweight Slab with Steel Frame%钢骨架轻型板的工程应用

    Institute of Scientific and Technical Information of China (English)

    陈剑峰

    2014-01-01

    从材料性能、施工工艺与经济性等方面,对新型建筑材料钢骨架轻型板与轻钢结构、传统钢筋混凝土结构材料作了对比分析,阐述了钢骨架轻型板的产品优势。在此基础上,结合某工程应用实例,从安装工艺、嵌缝施工、质量保证措施等方面,探讨了钢骨架轻型板施工的关键质量控制点。实践证明,钢骨架轻型板能满足现代建筑对轻质、节能、环保的要求,同时能缩短施工工期,节约工程造价,值得推广。%This paper conducts a comparative analysis on new building material lightweight slab with steel frame and traditional reinforced concrete structural materials from the aspects of construction technology and economy, and elaborates product advantages of the lightweight slab with steel frame. On this basis, it studies the key quality control points of the construction of lightweight slab with steel frame, with an engineering ap-plication example, in terms of the installation process, caulking construction, quality assurance measures. Practice has proved that the lightweight slab with steel frame can meet modern building for lightweight, ener-gy-saving, environmental protection requirements, and can shorten the construction period, reduce the project cost, and worth promoting.

  10. Repair of amalgam restorations with conventional and bonded amalgam: an in vitro study = Reparo de restaurações de amálgama com amálgama adesivo e convencional: estudo in vitro

    Directory of Open Access Journals (Sweden)

    Popoff, Daniela Araújo Veloso

    2010-01-01

    Full Text Available Objetivo: Avaliar a microinfiltração em restaurações de amálgama com reparo em amálgama ou amálgama adesivo. Métodos: Trinta pré-molares humanos extraídos foram restaurados com amálgama. Simu- lou-se um defeito nas restaurações reparado com: G1 - amálgama (n=15 (Permite C-SDI; G2 - amálgama adesivo (n=15 (Caulk 34% Condicionador dentário Gel – Dentsply + Prime & Bond 2. 1 – Dentsply + Permite C-SDI. Os dentes foram imersos em solução de nitrato de prata a 50%, termociclados e então, secionados longitudinalmente através da restauração e examinados por três examinadores usando um estereomicroscópio. A microinfiltração foi avaliada pela penetração de corante com uma escala de 0 a 4. Diferenças entre os grupos foram verificadas pelos testes Kruskal Wallis e Dunn. Resultados: Na interface reparo/dente, a técnica de reparo com amálgama adesivo foi signi- ficativamente mais efetiva, apresentando menor microinfiltração (escore 0=53. 3%, P= 0,0012. Já na interface reparo/restauração, houve menor microinfiltração nas restaurações reparadas com amálgama convencional (escore 0=86. 7%, P<0,001. Conclusão: Nenhum dos materiais eliminou a microinfiltração completamente. O uso de sistemas adesivos tem efeito significativo no selamento da interface reparo/dente, entretanto para interface reparo/restauração, ele pode aumentar a microinfiltração

  11. DNA Damage, Cell Cycle Arrest, and Apoptosis Induction Caused by Lead in Human Leukemia Cells.

    Science.gov (United States)

    Yedjou, Clement G; Tchounwou, Hervey M; Tchounwou, Paul B

    2016-01-01

    In recent years, the industrial use of lead has been significantly reduced from paints and ceramic products, caulking, and pipe solder. Despite this progress, lead exposure continues to be a significant public health concern. The main goal of this research was to determine the in vitro mechanisms of lead nitrate [Pb(NO₃)₂] to induce DNA damage, apoptosis, and cell cycle arrest in human leukemia (HL-60) cells. To reach our goal, HL-60 cells were treated with different concentrations of Pb(NO₃)₂ for 24 h. Live cells and necrotic death cells were measured by the propidium idiode (PI) assay using the cellometer vision. Cell apoptosis was measured by the flow cytometry and DNA laddering. Cell cycle analysis was evaluated by the flow cytometry. The result of the PI demonstrated a significant (p rupture by Pb(NO₃)₂ compared to the control. Data generated from the comet assay indicated a concentration-dependent increase in DNA damage, showing a significant increase (p < 0.05) in comet tail-length and percentages of DNA cleavage. Data generated from the flow cytometry assessment indicated that Pb(NO₃)₂ exposure significantly (p < 0.05) increased the proportion of caspase-3 positive cells (apoptotic cells) compared to the control. The flow cytometry assessment also indicated Pb(NO₃)₂ exposure caused cell cycle arrest at the G₀/G₁ checkpoint. The result of DNA laddering assay showed presence of DNA smear in the agarose gel with little presence of DNA fragments in the treated cells compared to the control. In summary, Pb(NO₃)₂ inhibits HL-60 cells proliferation by not only inducing DNA damage and cell cycle arrest at the G₀/G₁ checkpoint but also triggering the apoptosis through caspase-3 activation and nucleosomal DNA fragmentation accompanied by secondary necrosis. We believe that our study provides a new insight into the mechanisms of Pb(NO₃)₂ exposure and its associated adverse health effects. PMID:26703663

  12. Conceptual design and technology development of containment structure in Fusion Experimental Reactor (FER)

    International Nuclear Information System (INIS)

    A conceptual design of FER (Fusion Experimental Reactor) containment structure and its associated R and D activities, conducted from '89 to '90, are described. The FER containment structure system which mainly consists of a vacuum vessel, shielding structures, in-vessel replaceable components, ports, a cooling pipe system, has been developed to fullfil the required function. As an initial stage of R and D activities, the elemental technologies common to a tokamak reactor have been developed. Among them, a locking mechanism for supporting in-vessel replaceable components and a technique for insulation/conduction are described. For the locking mechanism, a caulking cotter driven by hydraulic pressure has been employed. Three kinds of hydraulic driving mechanism have been manufactured by trial: a 'piston jack' type, a 'bellows' type and a 'flexible tube' type. In the latter type, the stroke is obtained by changing the cross section of the flexible tube from a flat racetrack shape to a fat shape by hydraulic pressure. As the result of preliminary performance test, the shape of 'flexible tube' has been found to be improved. For the insulation coating, Al2O3 has been selected as the material and a plasma spray method has been applied as the coating procedure. For the conduction coating, Cr3C2 has been selected as the material and JET-KOTE method has been applied as the coating procedure. Both methods have been successfully developed and have been confirmed to be applicable the actual machine. A one fifth scale model has been fabricated in order to verify the design feasibility, mainly geometrical consistency. Then some design modifications were found to be needed for some of the components based on the manufacturing experience. (author)

  13. Preliminary experiences with 222Rn gas in Arizona homes

    International Nuclear Information System (INIS)

    Results of a survey of 222Rn gas using four-day charcoal canister tests in 759 Arizona homes are reported. Although the study was not random with respect to population or land area, it was useful in identifying areas at risk and locating several homes having elevated indoor 222Rn air concentrations. Approximately 18% of the homes tested exceeded 150 Bq m-3 (4 pCi L-1), with 7% exceeding 300 Bq m-3 (8 pCi L-1). Several Arizona cities had larger fractions of homes exceeding 150 Bq m-3 (4 pCi L-1), such as Carefree and Cave Creek (23%), Paradise Valley (30%), Payson (33%), and Prescott (31%). The Granite Dells and Groom Creek areas of Prescott had in excess of 40-60% of the houses tested exceeding 150 Bq m-3 (4 pCi L-1). Elevated 222Rn concentrations were measured for a variety of home types having different construction materials. Private well water was identified as a potentially significant source of 222Rn gas in Prescott homes, with water from one well testing over 3.5 MBq m-3 (94,000 pCi L-1). A 222Rn concentration in air exceeding 410,000 Bq m-3 (11,000 pCi L-1) was measured using a four-day charcoal canister test in a house in Prescott which had a well opening into a living space. Additional measurements in this 150-m3 dwelling revealed a strikingly heterogeneous 222Rn concentration. The excessive 222Rn level in the dwelling was reduced to less than 190 Bq m-3 (5.2 pCi L-1) by sealing the well head with caulking and providing passive ventilation through a pipe

  14. Flexural and diametral tensile strength of composite resins

    Directory of Open Access Journals (Sweden)

    Álvaro Della Bona

    2008-03-01

    Full Text Available This study evaluated the flexural strength (sf and the diametral tensile strength (st of light-cured composite resins, testing the hypothesis that there is a positive relation between these properties. Twenty specimens were fabricated for each material (Filtek Z250- 3M-Espe; AM- Amelogen, Ultradent; VE- Vit-l-escence, Ultradent; EX- Esthet-X, Dentsply/Caulk, following ISO 4049 and ANSI/ADA 27 specifications and the manufacturers’ instructions. For the st test, cylindrical shaped (4 mm x 6 mm specimens (n = 10 were placed with their long axes perpendicular to the applied compressive load at a crosshead speed of 1.0 mm/min. The sf was measured using the 3-point bending test, in which bar shaped specimens (n = 10 were tested at a crosshead speed of 0.5 mm/min. Both tests were performed in a universal testing machine (EMIC 2000 recording the fracture load (N. Strength values (MPa were calculated and statistically analyzed by ANOVA and Tukey (a = 0.05. The mean and standard deviation values (MPa were Z250-45.06 ± 5.7; AM-35.61 ± 5.4; VE-34.45 ± 7.8; and EX-42.87 ± 6.6 for st; and Z250-126.52 ± 3.3; AM-87.75 ± 3.8; VE-104.66 ± 4.4; and EX-119.48 ± 2.1 for sf. EX and Z250 showed higher st and sf values than the other materials evaluated (p < 0.05, which followed a decreasing trend of mean values. The results confirmed the study hypothesis, showing a positive relation between the material properties examined.

  15. Collector sealants and breathing. Final Report, 25 September 1978-31 December 1979

    Energy Technology Data Exchange (ETDEWEB)

    Mendelsohn, M A; Luck, R M; Yeoman, F A; Navish, Jr, F W

    1980-02-20

    The objectives of this program were: (1) to investigate the pertinent properties of a variety of possible sealants for solar collectors and identify the most promising candidates, and (2) to study the effect of breathing in flat-plate, thermal solar collector units. The study involved two types of sealants, Class PS which includes preformed seals or gaskets and Class SC which includes sealing compounds or caulks. It was the intent of the study to obtain data regarding initial properties of candidate elastomers from manufacturers and from the technical literature and to use those sources to provide data pertaining to endurance of these materials under environmental service conditions. Where necessary, these data were augmented by experimental measurements. Environmental stresses evaluated by these measurements included elevated temperatures, moisture, ultraviolet light, ozone and oxygen, and fungus. The second major area of the work involved a study of the effects of materials used and design on the durability of solar collectors. Factors such as design, fabrication, materials of construction, seals and sealing techniques and absorber plate coatings were observed on actual field units removed from service. Such phenomena as leakage, corrosion and formation of deposits on glazing and absorber plate were noted. An evaluation of the properties of several desiccants was made in order to providemeans to mitigate the deleterious effects of water on collector life. Adsorbents for organic degradation products of sealants were also investigated in order to protect the glazing and absorber plate from deposited coatings. Since adsorbents and desiccants in general tend to take up both water and organic decomposition products, relative affinities of a number of these agents for water and for organic compounds were determined . Results are presented in detail.

  16. Design and Delivery of a Filter for Removal of Siloxanes from the ISS Atmosphere

    Science.gov (United States)

    Carter, Layne; Kayatin, Matthew; Perry, Jay; Agui, Juan; Green, Robert; Gentry, Gregory; Bowman, Elizabeth; Wilson, Mark; Rector, Tony

    2016-01-01

    Dimethylsilanediol (DMSD) has been identified as a problematic chemical contaminant aboard ISS. This contaminant was initially identified in the ISS condensate and in the Water Processor Assembly (WPA) product water in 2010 when an increasing total organic carbon (TOC) trend was detected in the water produced by the WPA. DMSD is not a crew health hazard at the levels observed in the product water, but it may degrade the performance of the Oxygen Generation System (OGS) which uses product produced by the WPA for electrolysis. In addition, DMSD can prevent the effective operation of the WPA catalytic reactor, and necessitates early replacement of Multifiltration Beds in the WPA. An investigation into the source of DMSD has determined that polydimethylsiloxanes (PDMSs) are hydrolyzing in the Condensing Heat Exchanger (CHX) to form DMSD. PDMSs are prevalent aboard ISS from a variety of sources, including crew hygiene products, adhesives, caulks, lubricants, and various nonmetallics. TPDMSs are also implicated in CHX hydrophilic coating degradation, rendering it hydrophobic and adversely affecting its ability to effectively transmit water to the condensate bus. Eventually this loss in performance results in water droplets in the air flow out of the CHX core, which can lead to microbial growth in the air ducts and can impact the performance of downstream systems. Design concepts have now been developed for removing PDMS in the air stream before it can reach the CHX core, thus preventing degradation of the coating and decomposition of the PDMS to DMSD. This paper summarizes the current status of the effort to deliver filters to ISS for removing PDMSs from the atmosphere before they can adversely impact the performance of the CHX coating and the WPA.

  17. Analysis on Key Points for Construction of V-type Filter%V型滤池施工要点分析

    Institute of Scientific and Technical Information of China (English)

    黄建华

    2012-01-01

    结合参与裕园工业区净水厂V型滤池施工的实际情况,针对V型滤池的关键部位,探讨了V型滤池施工过程的技术要点及施工措施.在此工程施工实践中,总结了滤板、滤梁的施工及注意事项,H型槽及槽下的配气孔、配水孔施工,V型槽下表冲孔的施工方法,排水槽施工注意事项,确保滤板之间及滤板与池壁之间的缝隙密封严密,滤池内部尺寸的控制,滤池施工中的防渗漏处理,滤板安装嵌缝前必须注重对滤池底部的清洁等.%Combining with the actual construction of V-type filter in water purification plant of Yuyuan Industrial Zone, the technical main points and construction measures for the key positions of V-type filter were discussed. During the construction practice, some aspects were summarized as follows; filter board and filter beam construction and matters needing attention, construction of H groove and air and water distribution holes under the groove, construction of surface sweeping holes under V-type groove, points for attention in drainage channel construction, assurance of a tight seal between filter boards and between filter board and filter wall, control of internal filter size, seepage prevention treatment during filter construction, cleaning of filter bottom before caulking and so on.

  18. One-bottle adhesives: in vitro analysis of solvent volatilization and sealing ability.

    Science.gov (United States)

    Lima, Fábio Garcia; Moraes, Rafael Ratto de; Demarco, Flávio Fernando; Del Pino, Francisco Augusto Burkert; Powers, John

    2005-01-01

    The aim of this study was to compare the solvent volatilization rate and evaluate the sealing ability of different one-bottle adhesives that were in constant clinical use--an ethanol/water-based adhesive (Single Bond, 3M/ESPE-SB) and an acetone-based adhesive (Prime & Bond 2.1, Dentsply/Caulk-PB). Nine bottles of each agent were collected from the clinics of a dental school, and new ones were used as controls. The weight of all bottles and of empty bottles was determined using an analytical balance. A drop of each solution was dispensed onto the balance, taking its initial weight (IW) and, after 10 min, its final weight (FW). The IW/FW ratio was used to determine the solvents volatilization rate. The bottles with the highest evaporation levels (SB Control and PB Control) and with the lowest evaporation levels (SB Test and PB Test) of each agent were applied in Class V restorations with margins in dentin. Specimens were thermocycled and immersed in a 0.5% basic fuchsin solution. Dye penetration was evaluated under magnification and the data were submitted to the Kruskal-Wallis test. Solvent volatilization was faster for the acetone-based adhesive. IW/FW ratios ranged from 1.239 to 1.515 for SB, and from 3.488 to 6.476 for PB. The PB-Control and SB-Control groups exhibited similar microleakage patterns. The highest dye penetration scores were found for the PB-Test group (p < 0.05). Results indicate that the sealing ability can be affected by the repeated opening of acetone-based adhesive bottles. PMID:16491256

  19. Color Changing Hydrogen Sensors

    Science.gov (United States)

    Roberson, Luke B.; Williams, Martha; Captain, Janine E.; Mohajeri, Nahid; Raissi, Ali

    2015-01-01

    During the Space Shuttle Program, one of the most hazardous operation that occurred was the loading of liquid hydrogen (LH2) during fueling operations of the spacecraft. Due to hydrogen's low explosive limit, any amount leaked could lead to catastrophic event. Hydrogen's chemical properties make it ideal as a rocket fuel; however, the fuel is deemed unsafe for most commercial use because of the inability to easily detect the gas leaking. The increased use of hydrogen over traditional fossil fuels would reduce greenhouse gases and America's dependency on foreign oil. Therefore a technology that would improve safety at NASA and in the commercial sector while creating a new economic sector would have a huge impact to NASA's mission. The Chemochromic Detector for sensing hydrogen gas leakage is a color-changing detector that is useful in any application where it is important to know not only the presence but also the location of the hydrogen gas leak. This technology utilizes a chemochromicpigment and polymer matrix that can be molded or spun into rigid or pliable shapes useable in variable temperature environments including atmospheres of inert gas, hydrogen gas, or mixtures of gases. A change in color of the detector material indicates where gaseous hydrogen leaks are occurring. The irreversible sensor has a dramatic color change from beige to dark grey and remains dark grey after exposure. A reversible pigment changes from white to blue in the presence of hydrogen and reverts back to white in the presence of oxygen. Both versions of the sensor's pigments were comprised of a mixture of a metal oxide substrate and a hydro-chromic compound (i.e., the compound that changed color in the presence of hydrogen) and immediately notified the operator of the presence of low levels of hydrogen. The detector can be used in a variety of formats including paint, tape, caulking, injection molded parts, textiles and fabrics, composites, and films. This technology brings numerous

  20. MULTIDISCIPLINARY RESEARCH ON SHOREA JAVANICA

    Directory of Open Access Journals (Sweden)

    E.F. TORQUEBIAU*

    1987-01-01

    establishment of a permanent tree plantation, constitutes an efficient agroforestry system which is extensively described by Michon 1984, 1985; Michon et al 1984; and Torquebiau 1984. The resin of Shorea javanica is traditionally used for torches, caulking boats, batik coloring, etc., and is now exported to industrial countries where there is market for uses such as food additives, cosmetics, paints, varnishes a

  1. DNA Damage, Cell Cycle Arrest, and Apoptosis Induction Caused by Lead in Human Leukemia Cells

    Directory of Open Access Journals (Sweden)

    Clement G. Yedjou

    2015-12-01

    Full Text Available In recent years, the industrial use of lead has been significantly reduced from paints and ceramic products, caulking, and pipe solder. Despite this progress, lead exposure continues to be a significant public health concern. The main goal of this research was to determine the in vitro mechanisms of lead nitrate [Pb(NO32] to induce DNA damage, apoptosis, and cell cycle arrest in human leukemia (HL-60 cells. To reach our goal, HL-60 cells were treated with different concentrations of Pb(NO32 for 24 h. Live cells and necrotic death cells were measured by the propidium idiode (PI assay using the cellometer vision. Cell apoptosis was measured by the flow cytometry and DNA laddering. Cell cycle analysis was evaluated by the flow cytometry. The result of the PI demonstrated a significant (p < 0.05 increase of necrotic cell death in Pb(NO32-treated cells, indicative of membrane rupture by Pb(NO32 compared to the control. Data generated from the comet assay indicated a concentration-dependent increase in DNA damage, showing a significant increase (p < 0.05 in comet tail-length and percentages of DNA cleavage. Data generated from the flow cytometry assessment indicated that Pb(NO32 exposure significantly (p < 0.05 increased the proportion of caspase-3 positive cells (apoptotic cells compared to the control. The flow cytometry assessment also indicated Pb(NO32 exposure caused cell cycle arrest at the G0/G1 checkpoint. The result of DNA laddering assay showed presence of DNA smear in the agarose gel with little presence of DNA fragments in the treated cells compared to the control. In summary, Pb(NO32 inhibits HL-60 cells proliferation by not only inducing DNA damage and cell cycle arrest at the G0/G1 checkpoint but also triggering the apoptosis through caspase-3 activation and nucleosomal DNA fragmentation accompanied by secondary necrosis. We believe that our study provides a new insight into the mechanisms of Pb(NO32 exposure and its associated adverse

  2. Current developments in laser ablation-inductively coupled plasma-mass spectrometry for use in geology, forensics, and nuclear nonproliferation research

    Energy Technology Data Exchange (ETDEWEB)

    Messerly, Joshua D. [Iowa State Univ., Ames, IA (United States)

    2008-08-26

    This dissertation focused on new applications of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The diverse fields that were investigated show the versatility of the technique. In Chapter 2, LA-ICP-MS was used to investigate the rare earth element (REE) profiles of garnets from the Broken Hill Deposit in New South Wales, Australia. The normalized REE profiles helped to shed new light on the formation of deposits of sulfide ores. This information may be helpful in identifying the location of sulfide ore deposits in other locations. New sources of metals such as Pg, Zn, and Ag, produced from these ores, are needed to sustain our current technological society. The application of LA-ICP-MS presented in Chapter 3 is the forensics analysis of automotive putty and caulking. The elemental analysis of these materials was combined with the use of Principal Components Analysis (PCA). The PCA comparison was able to differentiate the automotive putty samples by manufacturer and lot number. The analysis of caulk was able to show a differentiation based on manufacturer, but no clear differentiation was shown by lot number. This differentiation may allow matching of evidence in the future. This will require many more analyses and the construction of a database made up of many different samples. The 4th chapter was a study of the capabilities of LA-ICP-MS for fast and precise analysis of particle ensembles for nuclear nonproliferation applications. Laser ablation has the ability to spatially resolve particle ensembles which may contain uranium or other actinides from other particles present in a sample. This is of importance in samples obtained from air on filter media. The particle ensembles of interest may be mixed in amongst dust and other particulates. A problem arises when ablating these particle ensembles directly from the filter media. Dust particles other than ones of interest may be accidentally entrained in the aerosol of the ablated particle

  3. POLYCHLORINATED BIPHENYL COMPLIANCE ISSUES IN THE 21ST CENTURY: POORLY RECOGNIZED AND POTENTIALLY DEVASTATING-8162

    International Nuclear Information System (INIS)

    Thirty-one years have passed since the United States Congress passed the Toxic Substances Control Act (TSCA) [1]. The 1976 law essentially eliminated future production of polychlorinated biphenyls (PCBs) within the United States and greatly limited the use of previously manufactured PCBs and PCB products. The ultimate objective of the law was the complete elimination of these chemicals due to concerns about their potentially toxic effects on health and the environment. PCBs were manufactured in the United States between 1929 and 1977. They were highly valued for their fire and heat-resistance properties and for their chemical stability. As a result, PCBs were used in a variety of thermally and/or chemically stressful applications. They did not conduct electricity and therefore were particularly well-suited for use as insulating fluids in high-voltage electric equipment. PCBs were also used in various other applications, such as in hydraulic and heat transfer fluids. Strict controls on the use and disposal of PCBs were imposed by the TSCA implementing regulations at 40 CFR 761 [2]. As a result, most heavy users of PCB products worked hard to curtail their PCB use. Many organizations that once used substantial amounts of PCBs, subsequently declared themselves ''PCB free''. Unfortunately, in many cases, these ''PCB-free'' declarations were premature, as PCBs were used in many more applications than insulating fluids. From the 1990s and to the present day, PCBs increasingly have been discovered in non-liquid forms. These materials were used or installed in facilities constructed before the 1979 ''PCB ban''. Examples include applied paints and coatings, caulking, pre-formed joint filler, and plastic or rubber wire and cable insulation. Proper identification of these materials is necessary for appropriate and compliant waste management during decommissioning and deactivation (D and D) activities. PCBs can pose other significant waste management issues for D and D

  4. Polychlorinated Biphenyl Compliance Issues in the 21. Century: Poorly Recognized and Potentially Devastating

    International Nuclear Information System (INIS)

    Thirty-one years have passed since the United States Congress passed the Toxic Substances Control Act (TSCA). The 1976 law essentially eliminated future production of polychlorinated biphenyls (PCBs) within the United States and greatly limited the use of previously manufactured PCBs and PCB products. The ultimate objective of the law was the complete elimination of these chemicals due to concerns about their potentially toxic effects on health and the environment. PCBs were manufactured in the United States between 1929 and 1977. They were highly valued for their fire and heat-resistance properties and for their chemical stability. As a result, PCBs were used in a variety of thermally and/or chemically stressful applications. They did not conduct electricity and therefore were particularly well-suited for use as insulating fluids in high-voltage electric equipment. PCBs were also used in various other applications, such as in hydraulic and heat transfer fluids. Strict controls on the use and disposal of PCBs were imposed by the TSCA implementing regulations at 40 CFR 761. As a result, most heavy users of PCB products worked hard to curtail their PCB use. Many organizations that once used substantial amounts of PCBs, subsequently declared themselves 'PCB free'. Unfortunately, in many cases, these 'PCB-free' declarations were premature, as PCBs were used in many more applications than insulating fluids. From the 1990's and to the present day, PCBs increasingly have been discovered in non-liquid forms. These materials were used or installed in facilities constructed before the 1979 'PCB ban'. Examples include applied paints and coatings, caulking, pre-formed joint filler, and plastic or rubber wire and cable insulation. Proper identification of these materials is necessary for appropriate and compliant waste management during deactivation and decommissioning (D and D) activities. PCBs can pose other significant waste management issues for D and D projects

  5. POLYCHLORINATED BIPHENYL COMPLIANCE ISSUES IN THE 21ST CENTURY: POORLY RECOGNIZED AND POTENTIALLY DEVASTATING-8162

    Energy Technology Data Exchange (ETDEWEB)

    Lowry, N

    2007-11-20

    Thirty-one years have passed since the United States Congress passed the Toxic Substances Control Act (TSCA) [1]. The 1976 law essentially eliminated future production of polychlorinated biphenyls (PCBs) within the United States and greatly limited the use of previously manufactured PCBs and PCB products. The ultimate objective of the law was the complete elimination of these chemicals due to concerns about their potentially toxic effects on health and the environment. PCBs were manufactured in the United States between 1929 and 1977. They were highly valued for their fire and heat-resistance properties and for their chemical stability. As a result, PCBs were used in a variety of thermally and/or chemically stressful applications. They did not conduct electricity and therefore were particularly well-suited for use as insulating fluids in high-voltage electric equipment. PCBs were also used in various other applications, such as in hydraulic and heat transfer fluids. Strict controls on the use and disposal of PCBs were imposed by the TSCA implementing regulations at 40 CFR 761 [2]. As a result, most heavy users of PCB products worked hard to curtail their PCB use. Many organizations that once used substantial amounts of PCBs, subsequently declared themselves ''PCB free''. Unfortunately, in many cases, these ''PCB-free'' declarations were premature, as PCBs were used in many more applications than insulating fluids. From the 1990s and to the present day, PCBs increasingly have been discovered in non-liquid forms. These materials were used or installed in facilities constructed before the 1979 ''PCB ban''. Examples include applied paints and coatings, caulking, pre-formed joint filler, and plastic or rubber wire and cable insulation. Proper identification of these materials is necessary for appropriate and compliant waste management during decommissioning and deactivation (D&D) activities. PCBs can pose other

  6. Properties of Waste from Coal Gasification in Entrained Flow Reactors in the Aspect of Their Use in Mining Technology / Właściwości odpadów ze zgazowania węgla w reaktorach dyspersyjnych w aspekcie ich wykorzystania w technologiach górniczych

    Science.gov (United States)

    Pomykała, Radosław

    2013-06-01

    Most of the coal gasification plants based of one of the three main types of reactors: fixed bed, fluidized bed or entrained flow. In recent years, the last ones, which works as "slagging" reactors (due to the form of generated waste), are very popular among commercial installations. The article discusses the characteristics of the waste from coal gasification in entrained flow reactors, obtained from three foreign installations. The studies was conducted in terms of the possibilities of use these wastes in mining technologies, characteristic for Polish underground coal mines. The results were compared with the requirements of Polish Standards for the materials used in hydraulic backfill as well as suspension technology: solidification backfill and mixtures for gob caulking. Większość przemysłowych instalacji zgazowania węgla pracuje w oparciu o jeden z trzech głównych typów reaktorów: ze złożem stałym, dyspersyjny lub fluidalny. W zależności od rodzaju reaktora oraz szczegółowych rozwiązań instalacji, powstające uboczne produkty zgazowania mogą mieć różną postać. Zależy ona w dużej mierze od stosunku temperatury pracy reaktora do temperatury topnienia części mineralnych zawartych w paliwie, czyli do temperatury mięknienia i topnienia popiołu. W ostatnich latach bardzo dużą popularność wśród instalacji komercyjnych zdobywają reaktory dyspersyjne "żużlujące". W takich instalacjach żużel jest wychwytywany i studzony po wypłynięciu z reaktora. W niektórych przypadkach oprócz żużla powstaje jeszcze popiół lotny, wychwytywany w systemach odprowadzania spalin. Może być on pozyskiwany oddzielnie lub też zawracany do komory reaktora, gdzie ulega stopieniu. Wszystkie z analizowanych odpadów - trzy żużle oraz popiół pochodzą właśnie z tego typu instalacji. Tylko z jednej z nich pozyskano zarówno żużel jak i popiół, z pozostałych dwóch jedynie żużel. Odpady te powstały, jako uboczny produkt zgazowania w