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Sample records for bevalac 1977-1980 lead

  1. Biological and medical research with accelerated heavy ions at the Bevalac, 1977-1980. [Lead abstract

    Energy Technology Data Exchange (ETDEWEB)

    Pirruccello, M.C.; Tobias, C.A. (eds.)

    1980-11-01

    Separate abstracts were prepared for the 46 papers presented in this progress report. This report is a major review of studies with accelerated heavy ions carried out by the Biology and Medicine Division of Lawrence Berkeley Laboratory from 1977 to 1980. (KRM)

  2. Bevalac extraction

    Energy Technology Data Exchange (ETDEWEB)

    Kalnins, J.G.; Krebs, G.; Tekawa, M.; Cowles, D.; Byrne, T.

    1992-02-01

    This report will describe some of the general features of the Bevatron extraction system, primarily the dependence of the beam parameters and extraction magnet currents on the Bevalac field. The extraction magnets considered are: PFW, XPl, XP2, XS1, XS2, XM1, XM2, XM3, XQ3A and X03B. This study is based on 84 past tunes (from 1987 to the present) of various ions (p,He,O,Ne,Si,S,Ar,Ca,Ti,Fe,Nb,La,Au and U), for Bevalac fields from 1.749 to 12.575 kG, where all tunes included a complete set of beam line wire chamber pictures. The circulating beam intensity inside the Bevalac is measured with Beam Induction Electrodes (BIE) in the South Tangent Tank. The extracted beam intensity is usually measured with the Secondary Emission Monitor (SEM) in the F1-Box. For most of the tunes the extraction efficiency, as given by the SEM/BIE ratio, was not recorded in the MCR Log Book, but plotting the available Log Book data as a function of the Bevalac field, see Fig.9, we find that the extraction efficiency is typically between 30->60% with feedback spill.

  3. Bevalac operations update

    Energy Technology Data Exchange (ETDEWEB)

    1991-02-01

    The Bevalac passed the recent Tiger Team assessment with flying colors, thanks to the unremitting effort of countless people over the last several months, pulling miles of cables, sending tons of valuable'' junk to salvage, painting, pushing brooms, writing operating procedures. It is time to look ahead now and plan for doing science again; however, it is not business as usual. The Bevalac survived, but not without changes. There are more procedures to be followed, safety appraisals to be made, training to be gone through. The primary goal is not just to get a task done, but to get it done in a safe manner according to code. If this means a delay in a run because enough time wasn't allotted for making a change in the setup, then the experiment will be delayed. Many of the obvious changes you will find the next time you come to work here are summarized in this newsletter. We will inform you of others as they are forthcoming. Also we will discuss these changes at our We Survived the Tigers, but{hor ellipsis}'' Users' Information Meeting at the Washington APS meeting. Details are inside this report.

  4. Relativistic uranium beams - the Bevalac experience

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, J.

    1983-03-01

    This paper will address areas where relativistic heavy ion accelerators differ from proton facilities. Salient areas are: (1) the specialized injectors for heavy ions; ion sources, structures for very low charge-to-mass ratio (q/A) ions, and stripper optimization; (2) special requirements for the synchrotron ring; ultrahigh vacuum, flexible controls and instrumentation. These areas are discussed in the context of the Bevalac, as well as our idea for a next-generation relativistic heavy ion accelerator.

  5. Bevatron/Bevalac user's handbook: biology and medicine. Revision

    Energy Technology Data Exchange (ETDEWEB)

    1985-04-01

    The Bevalac Biomedical Facility develops a source of near-relativistic heavy ions for applications to radiation biology, radiation therapy and diagnostic radiology. Pulsed beams of high LET heavy ions with variable pulse width, frequency, intensity and energy are produced and delivered to the Biomedical Facility by the Bevatron/Bevalac accelerator complex. Dosimetry equipment under computer control provides accurate determinations of absorbed doses in all regions of the Bragg curve. Depth-dose modifying devices and precise specimen positioning equipment are available. Animal housing and tissue culture facilities are convenient to the experimenter. This handbook is designed to provide the user with the relevant information for planning, proposing and executing an experiment.

  6. Comprehensive progress report, 1977-1980

    Energy Technology Data Exchange (ETDEWEB)

    Suyama, Y

    1980-01-01

    Research accomplishments and activities during the past three year period are described. Specific projects were: (1) restriction endonuclease studies of tetrahymena mtDNA; (2) biosynthesis of mitochondrial tRNA; and (3) structure and synthesis of tRNA charging enzymes. (ACR)

  7. Lead

    Science.gov (United States)

    ... found? Who is at risk? What are the health effects of lead? Get educational material about lead Get certified as a Lead Abatement Worker, or other abatement discipline Lead in drinking water Lead air pollution Test your child Check and maintain your home ...

  8. Biological and medical research with accelerated heavy ions at the Bevalac, 1974--1977. [Planning for use for radiotherapy and as radiation source for diagnostic radiography

    Energy Technology Data Exchange (ETDEWEB)

    Elam, S. (ed.)

    1977-04-01

    The Bevalac, a versatile high-energy heavy-ion accelerator complex, has been in operation for less than two years. A major purpose for which the Bevalac was constructed was to explore the possibility of heavy-ion teams for therapy for certain forms of cancer. Significant progress has been made in this direction. The National Cancer Institute has recognized the advantages that these and other accelerated particles offer, and heavy ions have been included in a long-term plan for particle therapy that will assess by means of controlled therapeutic tests the value of various modalities. Since accelerated heavy ions became available, the possibility of other contributions, not planned, became apparent. We are developig a new diagnostic method known as heavy-ion radiography that has greatly increased sensitivity for soft-tissue detail and that may become a powerful tool for localizing early tumors and metastases. We have discovered that radioactive beams are formed from fragmentation of stable deflected beams. Use of these autoradioactive beams is just beginning; however, we know that these beams will be helpful in localizing the region in the body where therapy is being delivered. In addition, it has been demonstrated that instant implantation of the radioactive beam allows direct measurements of blood perfusion rates in inaccessible parts of the body, and such a technique may become a new tool for the study of fast hot atom reactions in biochemistry, tracer biology and nuclear medicine. The Bevalac will also be useful for the continuation of previously developed methods for the control of acromegaly, Cushing's disease and, on a research basis, advanced diabetes mellitus with vascular disease. The ability to make small bloodless lesions in the brain and elsewhere with heavy-ion beams has great potential for nervous-system studies and perhaps later for radioneurosurgery.

  9. Heavy ion therapy: Bevalac epoch

    Energy Technology Data Exchange (ETDEWEB)

    Castro, J.R.

    1993-10-01

    An overview of heavy ion therapy at the Bevelac complex (SuperHILac linear accelerator + Bevatron) is given. Treatment planning, clinical results with helium ions on the skull base and uveal melanoma, clinical results with high-LET charged particles, neon radiotherapy of prostate cancer, heavy charged particle irradiation for unfavorable soft tissue sarcoma, preliminary results in heavy charged particle irradiation of bone sarcoma, and irradiation of bile duct carcinoma with charged particles and-or photons are all covered. (GHH)

  10. Reappraising Defense Organization: An Analysis Based on the Defense Organization Study of 1977-1980,

    Science.gov (United States)

    1983-01-01

    or all of the current structure and there- by presents the opportunity for some external entity to begin, like Moses, with a tabula rasa , the...fundamental role of the Department of Defense (DOD) has been to "provide for the common defence," as described in the US Constitution. This...be strengthened. Chapter 5 focuses on the military depart- ments, with particular emphasis on the role of the service secretar- ies. It recommends

  11. The Joint Chiefs of Staff and National Policy, 1977-1980

    Science.gov (United States)

    2015-01-01

    Joint Chiefs, it was up to the JDA, a component of REDCOM, to recommend concepts and procedures that elements of the unified and specified commands...1977 for their tenth Security Con- sultative Meeting ( SCM ). The SCM confirmed the interest of both the United States and South Korea in preserving...adopted at the SCM was virtually a carbon copy of a JCS-proposed command change which the Chiefs had long argued was needed to provide alternative

  12. Lead Poisoning

    Science.gov (United States)

    Lead is a metal that occurs naturally in the earth's crust. Lead can be found in all parts of our ... from human activities such as mining and manufacturing. Lead used to be in paint; older houses may ...

  13. Lead Toxicity

    Science.gov (United States)

    ... including some imported jewelry. What are the health effects of lead? • More commonly, lower levels of lead in children over time may lead to reduced IQ, slow learning, Attention Deficit Hyperactivity Disorder (ADHD), or behavioral issues. • Lead also affects other ...

  14. Lead Test

    Science.gov (United States)

    ... months, and at 3, 4, 5, and 6 years of age. A blood lead level test should be done only if the risk ... recommended if the person is symptomatic at any level below 70 mcg/dL. Because lead will pass through the blood to an unborn child, pregnant ...

  15. Lead Poisoning

    Science.gov (United States)

    ... menopause.) Once the lead is released from the mother's bones, it re-enters the blood stream and ... drinks. Avoid eating off any colorfully painted ceramic plates, and avoid drinking from any ceramic mugs unless ...

  16. Lead Poisoning

    Science.gov (United States)

    ... Topics Environment & Health Healthy Living Pollution Reduce, Reuse, Recycle Science – How It Works The Natural World Games ... OTHERS: Lead has recently been found in some plastic mini-blinds and vertical blinds which were made ...

  17. Ecotoxicology: Lead

    Science.gov (United States)

    Scheuhammer, A.M.; Beyer, W.N.; Schmitt, C.J.; Jorgensen, Sven Erik; Fath, Brian D.

    2008-01-01

    Lead (Pb) is a naturally occurring metallic element; trace concentrations are found in all environmental media and in all living things. However, certain human activities, especially base metal mining and smelting; combustion of leaded gasoline; the use of Pb in hunting, target shooting, and recreational angling; the use of Pb-based paints; and the uncontrolled disposal of Pb-containing products such as old vehicle batteries and electronic devices have resulted in increased environmental levels of Pb, and have created risks for Pb exposure and toxicity in invertebrates, fish, and wildlife in some ecosystems.

  18. Lead grids

    CERN Multimedia

    1974-01-01

    One of the 150 lead grids used in the multiwire proportional chamber g-ray detector. The 0.75 mm diameter holes are spaced 1 mm centre to centre. The grids were made by chemical cutting techniques in the Godet Workshop of the SB Physics.

  19. Leading men

    DEFF Research Database (Denmark)

    Bekker-Nielsen, Tønnes

    2016-01-01

    Through a systematic comparison of c. 50 careers leading to the koinarchate or high priesthood of Asia, Bithynia, Galatia, Lycia, Macedonia and coastal Pontus, as described in funeral or honorary inscriptions of individual koinarchs, it is possible to identify common denominators but also...

  20. Evaluation of problems and needs of veteran lower-limb amputees in the San Francisco Bay Area during the period 1977-1980.

    Science.gov (United States)

    Hoaglund, F T; Jergesen, H E; Wilson, L; Lamoreux, L W; Roberts, R

    1983-07-01

    From 1977 through 1980, 251 veterans from the San Francisco Bay Area received permanent lower-extremity prostheses at the two local Veterans Administration hospitals. For a survey, 213 of the 251 were contacted and 179 of them (84%) responded to written or telephone questionnaires concerning their prosthetic problems and complaints and their recommendations regarding prosthetic care. Seventy-four percent of the patients were traumatic amputees and 23 percent were dysvascular amputees. Eighty-six percent of the traumatic amputees said they wore their limbs all day, compared with only 51 percent of the dysvascular group. Seventy-one percent of traumatic and 43 percent of dysvascular amputees engaged in some form of recreational activity. There was a high incidence of complaints of pain in the residual limb: 55 percent among the dysvascular group and 44 percent among the traumatic group. Half of the patients had socket problems. Fifty-four of the 178 patients received a physical examination, a prosthetic evaluation, and a gait analysis. Among this group, 59 percent of the below-knee prostheses and 78 percent of the above-knee prostheses had inadequate socket fitting. Improper shaping of socket margins was the most frequently observed deficiency. Moreover, 41 percent of below-knee and 22 percent of above-knee amputees had mechanical skin irritation or skin breakdown in the examined residual limbs. Faulty suspension and alignment in addition to improper socket fit and construction contributed to this problem. Excessive stiffness of SACH foot heel cushions was the most common prosthetic foot problem and contributed to gait abnormalities.

  1. ALGUNS ASPECTOS DA REORGANIZAÇÃO DO MOVIMENTO DOS PROFESSORES PÚBLICOS DO ESTADO DO RIO DE JANEIRO (1977-1980

    Directory of Open Access Journals (Sweden)

    Sobreira Henrique Garcia

    2001-01-01

    Full Text Available O trabalho trata do movimento dos professores públicos conduzido pelo Centro Estadual de Profissionais de Ensino do Rio de Janeiro, entre 1977 e 1980. Resgatar a história da Entidade por meio de seus registros e documentos e investigar a possibilidade de as organizações docentes se configurarem como "educadoras do educador", inaugurando uma nova etapa na profissionalização do magistério, foram os objetivos da Dissertação de Mestrado que deu origem ao presente texto. Do confronto entre os documentos de partidos políticos (analisando o movimento e as entrevistas com diversos participantes do movimento, foi reconstruída a história dos primeiros anos da entidade. O papel do sindicato como Aparelho de Hegemonia (no sentido gramsciano, organizador político para além de defensor dos interesses econômico-corporativos é posto em dúvida diante dos resultados atingidos.

  2. Lead Poisoning Prevention Tips

    Science.gov (United States)

    ... or removed safely. How are children exposed to lead? Lead-based paint and lead contaminated dust are ... What can be done to prevent exposure to lead? It is important to determine the construction year ...

  3. Lead (Pb) Air Pollution

    Science.gov (United States)

    ... States Environmental Protection Agency Search Search Lead (Pb) Air Pollution Share Facebook Twitter Google+ Pinterest Contact Us As ... and protect aquatic and terrestrial ecosystems. Lead (Pb) Air Pollution Lead Air Pollution Basics How does lead get ...

  4. Lead and the Romans

    Science.gov (United States)

    Reddy, Aravind; Braun, Charles L.

    2010-01-01

    Lead poisoning has been a problem since early history and continues into modern times. An appealing characteristic of lead is that many lead salts are sweet. In the absence of cane and beet sugars, early Romans used "sugar of lead" (lead acetate) to sweeten desserts, fruits, and sour wine. People most at risk would have been those who consumed the…

  5. Lead and the Romans

    Science.gov (United States)

    Reddy, Aravind; Braun, Charles L.

    2010-01-01

    Lead poisoning has been a problem since early history and continues into modern times. An appealing characteristic of lead is that many lead salts are sweet. In the absence of cane and beet sugars, early Romans used "sugar of lead" (lead acetate) to sweeten desserts, fruits, and sour wine. People most at risk would have been those who…

  6. Jinde Lead lead smelting project starts construction

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>On Dec.20,the lead smelting project of Jiangxi Jinde Lead started construction in Dexin as a technical renovation project on environmental treatment of Jiangxi Metallurgical Group.The project is the one with the largest investment of Provincial Metallurgical Group in non-ferrous

  7. Lead - nutritional considerations

    Science.gov (United States)

    Lead poisoning - nutritional considerations; Toxic metal - nutritional considerations ... Markowitz M. Lead poisoning. In: Kliegman RM, Behrman RE, Jenson HB, ... Emergency Medicine: Concepts and Clinical Practice . 8th ed. ...

  8. Cryogenic current leads

    Energy Technology Data Exchange (ETDEWEB)

    Zizek, F.

    1982-01-01

    Theoretical, technical and design questions are examined of cryogenic current leads for SP of magnetic systems. Simplified mathematical models are presented for the current leads. To illustrate modeling, the calculation is made of the real current leads for 500 A and three variants of current leads for 1500 A for the enterprise ''Shkoda.''

  9. Rapid Lead Screening Test

    Science.gov (United States)

    ... Vitro Diagnostics Tests Used In Clinical Care Rapid Lead Screening Test Share Tweet Linkedin Pin it More ... reducing the need for a follow-up visit. Lead Risk Links Centers for Disease Control and Prevention ( ...

  10. Lead and tap water

    Science.gov (United States)

    Water contaminated with lead ... The Environmental Protection Agency (EPA) monitors drinking water in the United States. It requires water suppliers to produce annual water quality reports. These reports include information about lead amounts, and they ...

  11. Exposures to lead.

    Science.gov (United States)

    Callan, Anna C; Hinwood, Andrea L

    2011-01-01

    The Pacific Basin Consortium for Environment and Health hosted a workshop on Exposures to Lead. Speakers from Australia and the United States of America addressed current research knowledge on lead exposures and health effects in children, risk assessment and communication issues in dealing with lead exposure sources, different methods for assessing exposure, and the variety of scenarios where lead still remains a pollutant of concern. Mining continues to be a source of lead for many communities, and approaches to reducing exposures in these settings present particular challenges. A Perth Declaration for the Global Reduction of Childhood Lead Exposure was signed by participants of the meeting and is aimed at increasing attention to the need to continue to assess lead in the environment and to develop strategies to reduce lead in the environment and exposure by communities.

  12. Lead and Your Baby

    Science.gov (United States)

    ... who works with lead, like in auto repair, construction or in a plant that makes paint, batteries, ... who works with lead, like in auto repair, construction or in a plant that makes paint, batteries, ...

  13. Lead Poisoning (For Parents)

    Science.gov (United States)

    ... organs and tissues that need it, thus causing anemia. Most lead ends up in the bone, where it causes ... vomiting or nausea constipation pallor (pale skin) from ... look for lead poisoning or other health problems. Treatment Treatment for ...

  14. Occupational lead poisoning

    OpenAIRE

    Ramírez, Augusto V; Médico del Trabajo. American College of Occupational and Environmental Medicine.

    2013-01-01

    Lead, a ubiquitous heavy metal, has been found in places as unlikely as Greenland’s fossil ice. Egyptians and Hebrews used it. In Spain, Phoenicians c. 2000 BC worked ores of lead. At the end of the XX century, occupational lead’s poisoning became a public health problem in developed countries. In non-developed countries occupational lead poisoning is still frequent. Diagnosis is directed to recognize lead existence at the labor environment and good clinical and occupational documentation. Di...

  15. NA49: lead-lead collision

    CERN Document Server

    1996-01-01

    This is an image of an actual lead ion collision taken from tracking detectors on the NA49 experiment, part of the heavy ion project at CERN. These collisions produce a very complicated array of hadrons as the heavy ions break up. It is hoped that one of these collisions will eventually create a new state of matter known as quark-gluon plasma.

  16. Lead Poisoning in Children.

    Science.gov (United States)

    Drummond, A. H., Jr.

    1981-01-01

    Early symptoms of lead poisoning in children are often overlooked. Lead poisoning has its greatest effects on the brain and nervous system. The obvious long-term solution to the lead poisoning problem is removal of harmful forms of the metal from the environment. (JN)

  17. ALICE: Simulated lead-lead collision

    CERN Document Server

    2003-01-01

    This track is an example of simulated data modelled for the ALICE detector on the Large Hadron Collider (LHC) at CERN, which will begin taking data in 2008. ALICE will focus on the study of collisions between nuclei of lead, a heavy element that produces many different particles when collided. It is hoped that these collisions will produce a new state of matter known as the quark-gluon plasma, which existed billionths of a second after the Big Bang.

  18. Lead-Free Piezoelectrics

    CERN Document Server

    Nahm, Sahn

    2012-01-01

    Ecological restrictions in many parts of the world are demanding the elimination of Pb from all consumer items. At this moment in the piezoelectric ceramics industry, there is no issue of more importance than the transition to lead-free materials. The goal of Lead-Free Piezoelectrics is to provide a comprehensive overview of the fundamentals and developments in the field of lead-free materials and products to leading researchers in the world. The text presents chapters on demonstrated applications of the lead-free materials, which will allow readers to conceptualize the present possibilities and will be useful for both students and professionals conducting research on ferroelectrics, piezoelectrics, smart materials, lead-free materials, and a variety of applications including sensors, actuators, ultrasonic transducers and energy harvesters.

  19. Lead Poison Detection

    Science.gov (United States)

    1976-01-01

    With NASA contracts, Whittaker Corporations Space Science division has developed an electro-optical instrument to mass screen for lead poisoning. Device is portable and detects protoporphyrin in whole blood. Free corpuscular porphyrins occur as an early effect of lead ingestion. Also detects lead in urine used to confirm blood tests. Test is inexpensive and can be applied by relatively unskilled personnel. Similar Whittaker fluorometry device called "drug screen" can measure morphine and quinine in urine much faster and cheaper than other methods.

  20. Lead toxicity: Current concerns

    Energy Technology Data Exchange (ETDEWEB)

    Goyer, R.A. (Univ. of Western Ontario, London (Canada))

    1993-04-01

    Over the 20-year period since the first issue of Environmental Health Perspectives was published, there has been considerable progress in the understanding of the potential toxicity of exposure to lead. Many of these advances have been reviewed in published symposia, conferences, and review papers in EHP. This brief review identifies major advances as well as a number of current concerns that present opportunities for prevention and intervention strategies. The major scientific advance has been the demonstration that blood lead (PbB) levels of 10-15 micrograms/dL in newborn and very young infants result in cognitive and behavioral deficits. Further support for this observation is being obtained by prospective or longitudinal studies presently in progress. The mechanism(s) for the central nervous system effects of lead is unclear but involve lead interactions within calcium-mediated intracellular messenger systems and neurotransmission. Effects of low-level lead exposure on blood pressure, particularly in adult men, may be related to the effect of lead on calcium-mediated control of vascular smooth muscle contraction and on the renin-angiotensin system. Reproductive effects of lead have long been suspected, but low-level effects have not been well studied. Whether lead is a carcinogen or its association with renal adenocarcinoma is a consequence of cystic nephropathy is uncertain. Major risk factors for lead toxicity in children in the United States include nutrition, particularly deficiencies of essential metals, calcium, iron, and zinc, and housing and socioeconomic status. A goal for the year 2000 is to reduce prevalence of blood lead levels exceeding 15 micrograms/dL. 97 refs.

  1. Lead Time Study,

    Science.gov (United States)

    1982-05-01

    AD-A128 318 LEAD TIME STUDY (U) ARMY ARMAMENT RESEARCH AND DEVELOPMENT CDMMAND DOVER NJ SYSTEMS ANALYSIS DIV dI-T~~ CHU MAY 82 ARRAA 82- 3/ /l N...EhhEEE--E 1111.0 U 1 - I 1120 1.25I1,,-. 11.6 MICROCOPY RESOLUTION TESI CHARI NATIONAL BUREAU 01 STANDARDt 19t,3 A co LEAD TIME STUDY c*A JULIE CHU MAY...188 D I.-f . . .... .. - r - .. " ’- -~ L - - _ _ __ ARRAA 82-3 LEAD TIME STUDY Prepared by:_ JL CHU Reviewed by:Li t’ ( LAWRENCE J. QWUNI Chief, Sys

  2. Lead effects on fungi

    Energy Technology Data Exchange (ETDEWEB)

    Gullino, M.L.; Fiussello, N.

    1976-01-01

    Addition of 0.01M lead nitrate to media caused complete inhibition of most of a group of 80 strains of fungi of several genera. Those which did grow at all had an extended lag period in comparison to controls. At 0.001M all the fungi grew, but had thinner-than-normal mycelia and delayed fruiting body formation. Fusarium species and members of Class Basidiomycetes were among the most sensitive, and Penicillium and Aspergillus species were the most tolerant. Lead uptake rates varied positively with lead nitrate concentration in the media. 9 references, 2 figures, 3 tables.

  3. Learn about Lead

    Science.gov (United States)

    Jump to main content US EPA United States Environmental Protection Agency Search Search Lead Share Facebook Twitter Google+ ... 2 pp, 291 K, About PDF ) The most important step parents, doctors, and others can take is ...

  4. Lead levels - blood

    Science.gov (United States)

    Blood lead levels ... A blood sample is needed. Most of the time blood is drawn from a vein located on the inside ... may be used to puncture the skin. The blood collects in a small glass tube called a ...

  5. Lead User Innovation

    DEFF Research Database (Denmark)

    Brem, Alexander; Larsen, Henry

    2015-01-01

    , deliver and capture the value of an innovatively new device together. From the perspective of the lead user, we show antecedents and effects of social interaction between organizational actors and the lead user on the development of social capital, especially trust and shared imagination. The second case......User innovation and especially the integration of lead users is a key topic in the innovation management literature of recent years. This paper contributes by providing a rare perspective into what easily could be seen as innovation failure, shown from two perspectives. We show how a lack of shared...... imagination hampers participation and kills innovation between interdependent stakeholders at the threshold between invention and innovation in practice. We present a first case in the fun-sport industry where an external lead user and diverse firm representatives in different functions fail to create...

  6. Lead-210 contamination

    Energy Technology Data Exchange (ETDEWEB)

    Gray, P. [Peter Gray and Associates, Tulsa, OK (United States)

    1997-12-31

    Nearly all scrap dealers, smelters and other recyclers routinely monitor for radioactivity in shipments entering their facility. These sensitive radiation gate monitors easily detect radium-226 and most other radioactive nuclides. However, the type of detector normally used, sodium iodide scintillation crystals, will not detect the low energy gamma radiation emitted by lead-210 and its progeny. Since lead-210 is a common radioactive contaminant in certain industries, contaminated scrap metal from these industries may avoid detection at the recycler. Lead-210 is a decay product of radon-222 which is produced in small concentrations with natural gas. As the natural gas liquids, particularly ethane and propane, are separated from the natural gas, the radon concentrates in the ethane/propane fraction. The natural gas industry, particularly gas processing facilities and industries using ethane and propane as feed stocks can be significantly contaminated with the radon decay products, especially lead-210, bismuth-210 and polonium-210. Unless the scrap metal is decontaminated before sending to the recycler, the lead-210 contaminated scrap may be processed, resulting in some degree of radioactive contamination of the recycling facilities. Methods of detecting the low energy gamma radiation associated with lead-210 include the pancake G-M detector and the thin crystal-thin window scintillation detector.

  7. Magnesium Diboride Current Leads

    Science.gov (United States)

    Panek, John

    2010-01-01

    A recently discovered superconductor, magnesium diboride (MgB2), can be used to fabricate conducting leads used in cryogenic applications. Dis covered to be superconducting in 2001, MgB2 has the advantage of remaining superconducting at higher temperatures than the previously used material, NbTi. The purpose of these leads is to provide 2 A of electricity to motors located in a 1.3 K environment. The providing environment is a relatively warm 17 K. Requirements for these leads are to survive temperature fluctuations in the 5 K and 11 K heat sinks, and not conduct excessive heat into the 1.3 K environment. Test data showed that each lead in the assembly could conduct 5 A at 4 K, which, when scaled to 17 K, still provided more than the required 2 A. The lead assembly consists of 12 steelclad MgB2 wires, a tensioned Kevlar support, a thermal heat sink interface at 4 K, and base plates. The wires are soldered to heavy copper leads at the 17 K end, and to thin copper-clad NbTi leads at the 1.3 K end. The leads were designed, fabricated, and tested at the Forschungszentrum Karlsruhe - Institut foer Technische Physik before inclusion in Goddard's XRS (X-Ray Spectrometer) instrument onboard the Astro-E2 spacecraft. A key factor is that MgB2 remains superconducting up to 30 K, which means that it does not introduce joule heating as a resistive wire would. Because the required temperature ranges are 1.3-17 K, this provides a large margin of safety. Previous designs lost superconductivity at around 8 K. The disadvantage to MgB2 is that it is a brittle ceramic, and making thin wires from it is challenging. The solution was to encase the leads in thin steel tubes for strength. Previous designs were so brittle as to risk instrument survival. MgB2 leads can be used in any cryogenic application where small currents need to be conducted at below 30 K. Because previous designs would superconduct only at up to 8 K, this new design would be ideal for the 8-30 K range.

  8. Leading healthcare in complexity.

    Science.gov (United States)

    Cohn, Jeffrey

    2014-12-01

    Healthcare institutions and providers are in complexity. Networks of interconnections from relationships and technology create conditions in which interdependencies and non-linear dynamics lead to surprising, unpredictable outcomes. Previous effective approaches to leadership, focusing on top-down bureaucratic methods, are no longer effective. Leading in complexity requires leaders to accept the complexity, create an adaptive space in which innovation and creativity can flourish and then integrate the successful practices that emerge into the formal organizational structure. Several methods for doing adaptive space work will be discussed. Readers will be able to contrast traditional leadership approaches with leading in complexity. They will learn new behaviours that are required of complexity leaders, along with challenges they will face, often from other leaders within the organization.

  9. Relational Perspectives on Leading

    DEFF Research Database (Denmark)

    Larsen, Mette Vinther; Rasmussen, Jørgen Gulddahl

    2015-01-01

    Relational Perspectives on Leading discusses leadership from a relational and social constructionism perspective as practiced on an everyday basis between people. The book pursues a fast growing, practice-based approach - particularly within the Anglo-Saxon parts of the world - to organization...... studies and organizational phenomena....

  10. Change, Lead, Succeed

    Science.gov (United States)

    Munger, Linda; von Frank, Valerie

    2010-01-01

    Redefine leadership in your school, and create capacity through school leadership teams that successfully coordinate professional learning. "Change, Lead, Succeed" shows school leaders and teachers in leadership roles what they need to know to effectively create a culture for change. Find out what distinguishes a school leadership team from other…

  11. lead glass brick

    CERN Multimedia

    As well as accelerators to boost particles up to high energy, physicists need detectors to see what happens when those particles collide. This lead glass block is part of a CERN detector called OPAL. OPAL uses some 12 000 blocks of glass like this to measure particle energies.

  12. Leading Generation Y

    Science.gov (United States)

    2008-04-01

    ensure the success of their child, failure is not often experienced. These successes and the ease of childhood lead to not only confidence but an...Messaging, chatting on the cell phone and working on homework is a common place scene for teens and college students. “The level of multiprocessing...to Gen Yers entering the workforce with unrealistic expectations and a sense of entitlement. Barbara Dwyer, CEO of the Job Journey, states that

  13. Superconductivity of lead

    Energy Technology Data Exchange (ETDEWEB)

    Boorse, H.A.; Cook, D.B.; Zemansky, W.M.

    1950-06-01

    Numerous determinations of the zero-field transition temperature of lead have been made. All of these observations except that of Daunt were made by the direct measurement of electrical resistance. Daunt`s method involved the shielding effect of persistent currents in a hollow cylinder. In the authors work on columbium to be described in a forthcoming paper an a.c. induction method was used for the measurement of superconducting transitions. The superconductor was mounted as a cylindrical core of a coil which functioned as the secondary of a mutual inductance. The primary coil was actuated by an oscillator which provided a maximum a.c. field within the secondary of 1.5 oersteds at a frequency of 1000 cycles per second. The secondary e.m.f. which was dependent for its magnitude on the permeability of the core was amplified, rectifie, and observed on a recording potentiometer. During the application of this method to the study of columbium it appeared that a further check on the zero-field transition temperature of lead would be worth while especially if agreement between results for very pure samples could be obtained using this method. Such result would help in establishing the lead transition temperature as a reasonably reproducible reference point in the region between 4 deg and 10 deg K.

  14. lead glass brick

    CERN Multimedia

    When you look through the glass at a picture behind, the picture appears raised up because light is slowed down in the dense glass. It is this density (4.06 gcm-3) that makes lead glass attractive to physicists. The refractive index of the glass is 1.708 at 400nm (violet light), meaning that light travels in the glass at about 58% its normal speed. At CERN, the OPAL detector uses some 12000 blocks of glass like this to measure particle energies.

  15. Leading change: 2--planning.

    Science.gov (United States)

    Kerridge, Joanna

    National initiatives have outlined the importance of involving frontline staff in service improvement, and the ability to influence and manage change has been identified as an essential skill for delivering new models of care. Nurses often have to take the lead in managing change in clinical practice. The second in a three-part series is designed to help nurses at all levels develop the knowledge and skills to function as change agents within their organisations. This article focuses on planning the change and dealing with resistance.

  16. Optimization leads to symmetry

    Institute of Scientific and Technical Information of China (English)

    Chenghong WANG; Yuqian GUO; Daizhan CHENG

    2004-01-01

    The science of complexity studies the behavior and properties of complex systems in nature and human society.Particular interest has been put on their certain simple common properties.Symmetry is one of such properties.Symmetric phenomena can be found in many complex systems.The purpose of this paper is to reveal the internal reason of the symmetry.Using some physical systems and geometric objects,the paper shows that many symmetries are caused by optimization under certain criteria.It has also been revealed that an evolutional process may lead to symmetry.

  17. Turning lead into gold

    DEFF Research Database (Denmark)

    Jensen, Steffen Moltrup Ernø

    For years the field of entrepreneurship has been blinded by the alchemical promise of turning lead into gold, of finding the ones most likely to become the next Branson, Zuckerberg or Gates. The promise has been created in the midst of political and scientific agendas where certain individuals...... is not to accumulate state or market wealth, but for entrepreneurial skills to become tools towards the liberation of the individual from oppressive systems of control – essentially to add public value rather than economic value. In this presentation I will sketch an anarchist perspective on entrepreneurship, looking...

  18. Cofilin takes the lead.

    Science.gov (United States)

    DesMarais, Vera; Ghosh, Mousumi; Eddy, Robert; Condeelis, John

    2005-01-01

    Cofilin has emerged as a key regulator of actin dynamics at the leading edge of motile cells. Through its actin-severing activity, it creates new actin barbed ends for polymerization and also depolymerizes old actin filaments. Its function is tightly regulated in the cell. Spatially, its activity is restricted by other actin-binding proteins, such as tropomyosin, which compete for accessibility of actin filament populations in different regions of the cell. At the molecular level, it is regulated by phosphorylation, pH and phosphatidylinositol (4,5)-bisphosphate binding downstream of signaling cascades. In addition, it also appears to be regulated by interactions with 14-3-3zeta and cyclase-associated protein. In vivo, cofilin acts synergistically with the Arp2/3 complex to amplify local actin polymerization responses upon cell stimulation, which gives it a central role in setting the direction of motility in crawling cells.

  19. Lead telluride alloy thermoelectrics

    Directory of Open Access Journals (Sweden)

    Aaron D. LaLonde

    2011-11-01

    Full Text Available The opportunity to use solid-state thermoelectrics for waste heat recovery has reinvigorated the field of thermoelectrics in tackling the challenges of energy sustainability. While thermoelectric generators have decades of proven reliability in space, from the 1960s to the present, terrestrial uses have so far been limited to niche applications on Earth because of a relatively low material efficiency. Lead telluride alloys were some of the first materials investigated and commercialized for generators but their full potential for thermoelectrics has only recently been revealed to be far greater than commonly believed. By reviewing some of the past and present successes of PbTe as a thermoelectric material we identify the issues for achieving maximum performance and successful band structure engineering strategies for further improvements that can be applied to other thermoelectric materials systems.

  20. Polymorphism of lead oxoborate

    Energy Technology Data Exchange (ETDEWEB)

    Tyulyupa, A.G. [Middle School, Sablinskoe, Stavropol region, 356322 (Russian Federation); Voronov, V.V. [A.M. Prokhorov General Physics Institute RAS, 38 Vavilov Street, Moscow 119991 (Russian Federation); Fedorov, P.P., E-mail: ppfedorov@yandex.ru [A.M. Prokhorov General Physics Institute RAS, 38 Vavilov Street, Moscow 119991 (Russian Federation)

    2015-07-20

    Highlights: • Pb{sub 4}B{sub 2}O{sub 7} melt undergoes statistical undercooling. • Orthorhombic nonlinear optical crystal Pb{sub 4}O(BO{sub 3}){sub 2} is the metastable γ-polymorph. • Temperature of metastable melting of γ-Pb{sub 4}O(BO{sub 3}){sub 2} is equal to 530 °C. - Abstract: The study of lead borate melt crystallization by differential thermal analysis (DTA) and X-ray diffraction analysis has shown that, for Pb{sub 4}O(BO{sub 3}){sub 2} (or 4PbO·B{sub 2}O{sub 3}) stoichiometric compound, its well-known orthorhombic modification (non-centrosymmetric Aba2 space symmetry group (SSG), a = 15.472(1), b = 10.802(1), c = 9.9486(6) Å unit cell parameters) is metastable. It forms from the undercooled melt and has a melting point of 530 ± 5 °C.

  1. A SURVEY ON LEAD INTOXICATION IN LEAD MINERS

    Directory of Open Access Journals (Sweden)

    P. Meshgi

    1972-12-01

    Full Text Available A survey on lead intoxication in lead mine workers was carried out among Khanehsorme, lead miners in NajafAabad and also in Ab-bagh lead miners in Shahreza, both located in district of Esfahan, Iran. The studies were carried out on 62 miners out of 82 employees in Khanehsorme, 25 miners out of 27 employees in Ab-bagh lead miners and 47 rural inhabitants in the surroundings of mines were selected as the Control group. Clinical examinations were done. Age and sex group, working hours, type of work, and duration of service and previous occupation of workers were questioned. The determination of lead in urine was done according to Truhaut et Boudene's method and the content of blood Hemoglobin was performed according to Sali method. Results obtained in lead miners in comparison with the control group showed the absorption of lead and consequently lead intoxication was observed some extent.

  2. Leading Your Leaders

    Science.gov (United States)

    Hale, Wayne N.

    2008-01-01

    life is good. More often when an unbelievably difficult test fails, we are left with a very long discussion of why and what was wrong in the design or execution of the test. Make sure that the test is well defined. Even then, it is important to explain to your leaders what inherent accuracy (or error) the test conditions or equipment have and what the assumptions or initial conditions were for the test. Test results without a good understanding of the test's accuracy or the pedigree of the test assumptions are worth very little. Finally, there is flight test data. Always limited, never at the edge of the envelope, it still shows how the real hardware works in a combined environment. Flight experience is dangerous because it typically doesn't show how close to the edge of the cliff the equipment is operating, but it does demonstrate how the hardware really works. A flight test is the ultimate test, again taken with the knowledge that it is probably not the extreme but something more like the middle of the environmental and systems performance. Good understanding of a problem and its solution always relies on a combination of all these methods. Be sure to lead your leaders by using all the tools you have at your disposal. At the end of the day, decisions in space flight always come down to a risk trade. Our business is not remotely safe, not in the sense that the public, the media, or our legislators use the term. Everything we do has a risk, cost, schedule, or performance trade-off. For your leaders to make an appropriate decision, you need to educate them, lead them, talk with them, and engage them in the discussion until full understanding takes place. It's your job. *

  3. Drowning: a leading killer!

    Directory of Open Access Journals (Sweden)

    Nuno Domingos Garrido

    2016-10-01

    Full Text Available Drowning kills at least 372,000 people worldwide every year and is the 3rd leading cause of unintentional death, accounting for 7% of all deaths stemming from accidents (WHO, 2014. Conceptually, “drowning” is a complex and multi-faceted phenomenon, characterized as a chain of events (Bierens, 2006. Drowning is defined as the process of experiencing respiratory impairment from immersion or submersion in liquid. Research on drowning as a phenomenon presents several difficulties - most of all, that global data concerning the number of occurrences are not accurate. Nevertheless, detailed analysis of the registered incidents allows the identification of risk factors of drowning. An in-depth analysis of the risk factors is the basis for the creation of targeted and effective strategies to prevent drowning. Due to variability of situations which could lead to a drowning episode, experts suggest the adoption of a multi-layer prevention model, rather than opting for isolated measures, since no single measure can prevent all deaths and injuries caused by submersion. Among the preventive measures we would like to emphasize instruction in swimming and water safety. So, what does "knowing how to swim" really mean? Some authors define mastery of this competence as swimming a given distance, while others put the emphasis on how this/any given distance is swum (Stallman, Junge, & Blixt, 2008. It has long been realized that there is no contradiction between learning those competencies which make a person less susceptible to drowning and those competencies which prepare the path towards higher levels of performance and competition. Aquatic movement researchers and practitioners and drowning prevention researchers and practitioners, share in the responsibility for drowning prevention though they are often unaware of it. The question “What should be taught to children?” is too infrequently asked. There remains great variation in what is taught and programs

  4. Current issues in human lead exposure and regulation of lead.

    Science.gov (United States)

    Davis, J M; Elias, R W; Grant, L D

    1993-01-01

    Concern about lead as a significant public health problem has increased as epidemiological and experimental evidence has mounted regarding adverse health effects at successively lower levels of lead exposure. This concern has led to downward revision of criteria for acceptable blood lead concentrations to the 10 micrograms/dL mark now designated by EPA as a target level for regulatory development and enforcement/clean-up purposes. Much progress has been made in reducing lead exposures during the past 10-15 years, with marked declines evident both in air lead and blood lead concentrations in parallel to the phase-down of lead in gasoline and notable decreases in food lead exposure due to elimination of lead soldered cans by U.S. food processors. With the lessening of exposure from these sources, the importance of other components of multimedia exposure pathways has grown and stimulated increasing regulatory attention and abatement efforts to reduce health risks associated with lead exposure from drinking water, from lead-based paint, and from household dust and soil contaminated by deteriorating paint, smelter emissions, or various other sources. Increasing attention is also being accorded to reduction of occupational lead exposures (including those related to lead abatement activities), with particular concern for protection of men and women during their reproductive years.

  5. Lead in School Drinking Water.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC. Office of Water Programs.

    Lead levels in school drinking water merit special concern because children are more at risk than adults from exposure to lead. This manual provides ways in which school officials can minimize this risk. It assists administrators by providing: (1) general information on the significance of lead in school drinking water and its effects on children;…

  6. Lead exposure among lead-acid battery workers in Jamaica.

    Science.gov (United States)

    Matte, T D; Figueroa, J P; Burr, G; Flesch, J P; Keenlyside, R A; Baker, E L

    1989-01-01

    To assess lead exposure in the Jamaican lead-acid battery industry, we surveyed three battery manufacturers (including 46 production workers) and 10 battery repair shops (including 23 battery repair workers). Engineering controls and respiratory protection were judged to be inadequate at battery manufacturers and battery repair shops. At manufacturers, 38 of 42 air samples for lead exceeded a work-shift time-weighted average concentration of 0.050 mg/m3 (range 0.030-5.3 mg/m3), and nine samples exceeded 0.50 mg/m3. Only one of seven air samples at repair shops exceeded 0.050 mg/m3 (range 0.003-0.066 mg/m3). Repair shop workers, however, had higher blood lead levels than manufacturing workers (65% vs. 28% with blood lead levels above 60 micrograms/dl, respectively). Manufacturing workers had a higher prevalence of safe hygienic practices and a recent interval of minimal production had occurred at one of the battery manufacturers. Workers with blood lead levels above 60 micrograms/dl tended to have higher prevalences of most symptoms of lead toxicity than did workers with lower blood lead levels, but this finding was not consistent or statistically significant. The relationship between zinc protoporphyrin concentrations and increasing blood lead concentrations was consistent with that described among workers in developed countries. The high risk of lead toxicity among Jamaican battery workers is consistent with studies of battery workers in other developing countries.

  7. Lead resistant bacteria: lead resistance mechanisms, their applications in lead bioremediation and biomonitoring.

    Science.gov (United States)

    Naik, Milind Mohan; Dubey, Santosh Kumar

    2013-12-01

    Lead (Pb) is non-bioessential, persistent and hazardous heavy metal pollutant of environmental concern. Bioremediation has become a potential alternative to the existing technologies for the removal and/or recovery of toxic lead from waste waters before releasing it into natural water bodies for environmental safety. To our best knowledge, this is a first review presenting different mechanisms employed by lead resistant bacteria to resist high levels of lead and their applications in cost effective and eco-friendly ways of lead bioremediation and biomonitoring. Various lead resistant mechanisms employed by lead resistant bacteria includes efflux mechanism, extracellular sequestration, biosorption, precipitation, alteration in cell morphology, enhanced siderophore production and intracellular lead bioaccumulation.

  8. Lead levels of Culex mosquito larvae inhabiting lead utilizing factory

    Institute of Scientific and Technical Information of China (English)

    Kitvatanachai S; Apiwathnasorn C; Leemingsawat S; Wongwit W; Overgaard HJ

    2011-01-01

    Objective: To determine lead level primarily in Culex quinquefasciatus (Cx. quinquefasciatus), and Culex gelidus (Cx. gelidus) larvae inhabiting lead consuming factories, and to putatively estimate eco-toxicological impact of effluents from the firms. Methods: Third instars larvae were sampled by standard dipping method and lead concentrations in the larvae and their respective surrounding factory aquatic environments were determined through standard atomic absorption spectrophotometry (AAS). Results: Cx. quinquefasciatus was the most abundant species followed by Cx. gelidus. The levels of lead were higher in the Cx. quinquefasciatus (1.08-47.47 μg/g), than in the wastewaters surface (0.01-0.78 μg/mL) from the factories or closer areas around factories. Other species were not reaching the criteria for lead determination. Conclusions: The Cx.quinquefasciatus larvae can bio-accumulate the metal and can potentially serve as a biomarker of lead contamination, to complemente conventional techniques.

  9. Prevalence of lead disease among secondary lead smelter workers and biological indicators of lead exposure

    Energy Technology Data Exchange (ETDEWEB)

    Lilis, R. (City Univ. of New York); Fischbein, A.; Eisinger, J.

    1977-10-01

    The report concerns itself primarily with the assessment of medical and biochemical effects of chronic lead exposure and comparing the usefulness of various biological screening parameters. In addition it appraises the effects of chelation therapy to control blood lead levels in lead workers, which have recently attracted critical attention. It is of considerable importance to ascertain whether such a therapeutic approach may, under some circumstances, in fact contribute to the deleterious effects of undue lead exposure.

  10. Chronic lead poisoning in horses

    Energy Technology Data Exchange (ETDEWEB)

    Knight, H.D.; Burau, R.G.

    1973-05-01

    Chronic lead poisoning in horses was manifested as anorexia, loss of body weight, muscular weakness, anemia, laryngeal hemiplegia, and, terminally, inhalation pneumonia. Some deaths were sudden and unexplained. The lead content in liver specimens from 10 horses was greater than that considered indicative of lead intoxication; however, the lead content of blood was equivocal. The most conclusive laboratory finding was increased urine lead concentration after chelation therapy. The concentration of lead in a sample of vegetation considered to be representative of what a horse would eat if he was grazing in the area sampled was 325 ppM (oven-dry basis). It was determined that a 450-kg horse grazing grass of this lead content would consume 2.9 Gm of lead daily (6.4 mg/kg of body weight), an amount considered toxic for horses. Leaching lowered the calcium content of the forage but failed to reduce the lead concentration of the plants significantly, thus opening the possibility that winter rains might have influenced the onset of poisoning. Airborne fallout from a nearby lead smelter was proposed as the primary mode of pasture contamination.

  11. Combined processing of lead concentrates

    Science.gov (United States)

    Kubasov, V. L.; Paretskii, V. M.; Sidorin, G. N.; Travkin, V. F.

    2013-06-01

    A combined scheme of processing of lead concentrates with the production of pure metallic lead and the important components containing in these concentrates is considered. This scheme includes sulfating roasting of the lead concentrates and two-stage leaching of the formed cinder with the formation of a sulfate solution and lead sulfate. When transformed into a carbonate form, lead sulfate is used for the production of pure metallic lead. Silver, indium, copper, cadmium, nickel, cobalt, and other important components are separately extracted from a solution. At the last stage, zinc is extracted by either extraction followed by electrolytic extraction of a metal or the return of the forming solution of sulfuric acid to cinder leaching.

  12. Lead Levels in Utah Eagles

    Science.gov (United States)

    Arnold, Michelle

    2006-10-01

    Lead is a health hazard to most animals, causing adverse effects to the nervous and reproductive systems if in sufficient quantity. Found in most fishing jigs and sinkers, as well as some ammunition used in hunting, this metal can poison wildlife such as eagles. Eagles are raptors, or predatory birds, and their lead exposure would most likely comes from their food -- a fish which has swallowed a sinker or lead shot in carrion (dead animal matter). As part of an ongoing project to investigate the environment lead levels in Utah, the bone lead levels in the wing bones of eagles have been measured for eagle carcasses found throughout Utah. The noninvasive technique of x-ray fluorescence was used, consisting of a Cd-109 radioactive source to activate lead atoms and a HPGe detector with digital electronics to collect the gamma spectra. Preliminary results for the eagles measured to date will be presented.

  13. Undue Lead Absorption and Lead Poisoning in Children: An Overview.

    Science.gov (United States)

    Lin-Fu, J. S.

    The toxic effects of lead, a useful metal ubiquitous in the human environment, have long been known. The occupational hazards of lead poisoning were well established by the early 19th century, but plumbism in children caused by paint ingestion was not reported until the turn of the century. Even in 1924, the child was said to live in a "lead…

  14. Taking the Lead : Gender, Social Context and Preference to Lead

    NARCIS (Netherlands)

    Hong, A.P.C.I.; Schaafsma, J.; van der Wijst, P.J.

    2014-01-01

    Previous research has demonstrated that women tend to emerge as leaders less often than men. In the present study, we examined to what extent women's and men's preference to lead is influenced by social context. It was hypothesized that women have a less strong preference to lead than men in a compe

  15. Archives of Atmospheric Lead Pollution

    Science.gov (United States)

    Weiss, Dominik; Shotyk, William; Kempf, Oliver

    Environmental archives such as peat bogs, sediments, corals, trees, polar ice, plant material from herbarium collections, and human tissue material have greatly helped to assess both ancient and recent atmospheric lead deposition and its sources on a regional and global scale. In Europe detectable atmospheric lead pollution began as early as 6000years ago due to enhanced soil dust and agricultural activities, as studies of peat bogs reveal. Increased lead emissions during ancient Greek and Roman times have been recorded and identified in many long-term archives such as lake sediments in Sweden, ice cores in Greenland, and peat bogs in Spain, Switzerland, the United Kingdom, and the Netherlands. For the period since the Industrial Revolution, other archives such as corals, trees, and herbarium collections provide similar chronologies of atmospheric lead pollution, with periods of enhanced lead deposition occurring at the turn of the century and since 1950. The main sources have been industry, including coal burning, ferrous and nonferrous smelting, and open waste incineration until c.1950 and leaded gasoline use since 1950. The greatest lead emissions to the atmosphere all over Europe occurred between 1950 and 1980 due to traffic exhaust. A marked drop in atmospheric lead fluxes found in most archives since the 1980s has been attributed to the phasing out of leaded gasoline. The isotope ratios of lead in the various archives show qualitatively similar temporal changes, for example, the immediate response to the introduction and phasing out of leaded gasoline. Isotope studies largely confirm source assessments based on lead emission inventories and allow the contributions of various anthropogenic sources to be calculated.

  16. Teratogen update: lead and pregnancy.

    Science.gov (United States)

    Bellinger, David C

    2005-06-01

    This review focuses on the impacts of lead exposure on reproductive health and outcomes. High levels of paternal lead exposure (>40 microg/dl or >25 microg/dl for a period of years) appear to reduce fertility and to increase the risks of spontaneous abortion and reduced fetal growth (preterm delivery, low birth weight). Maternal blood lead levels of approximately 10 microg/dl have been linked to increased risks of pregnancy hypertension, spontaneous abortion, and reduced offspring neurobehavioral development. Somewhat higher maternal lead levels have been linked to reduced fetal growth. Some studies suggest a link between increased parental lead exposure and congenital malformations, although considerable uncertainty remains regarding the specific malformations and the dose-response relationships. Common methodological weaknesses of studies include potential exposure misclassifications due to the frequent unavailability of exposure biomarker measurements at biologically appropriate times and uncertainty regarding the best exposure biomarker(s) for the various outcomes. A special concern with regard to the pregnant woman is the possibility that a fetus might be exposed to lead mobilized from bone stores as a result of pregnancy-related metabolic changes, making fetal lead exposure the result of exposure to exogenous lead during pregnancy and exposure to endogenous lead accumulated by the woman prior to pregnancy. By reducing bone resorption, increased calcium intake during the second half of pregnancy might reduce the mobilization of lead from bone compartments, even at low blood lead levels. Subgroups of women who incurred substantial exposures to lead prior to pregnancy should be considered to be at increased risk.

  17. Recovery of indium and lead from lead bullion

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Lead and indium were recovered by electrolysis and nonequilibrium solvent extraction process from lead bullion.The effects of current density,electrolytic period and circle amnant of electrolyte on the electrochemical dissolution of lead and indium were investigated.The effects of extraction phase ratio and mixing time on solvent extraction of indium and striping phase ratio and stripping stage on the loaded organic phase stripping were also investigated.The experimental results indicate that under optimum conditions,the purity of lead deposited on cathode is 98.5% and the deposit rate of lead is 99.9%,the dissolution rate of indium is 94.28%,the extraction rate of indium is 98.69%,the stripping rate of indium is almost 100%,and the impurity elements,such as Zn,Fe and Sn can be removed.

  18. Safe Leads and Lead Changes in Competitive Team Sports

    CERN Document Server

    Clauset, A; Redner, S

    2015-01-01

    We investigate the time evolution of lead changes within individual games of competitive team sports. Exploiting ideas from the theory of random walks, the number of lead changes within a single game follows a Gaussian distribution. We show that the probability that the last lead change and the time of the largest lead size are governed by the same arcsine law, a bimodal distribution that diverges at the start and at the end of the game. We also determine the probability that a given lead is "safe" as a function of its size $L$ and game time $t$. Our predictions generally agree with comprehensive data on more than 1.25 million scoring events in roughly 40,000 games across four professional or semi-professional team sports, and are more accurate than popular heuristics currently used in sports analytics.

  19. Lead Poisoning in Wild Birds

    Science.gov (United States)

    Lahner, Lesanna L.; Franson, J. Christian

    2009-01-01

    Lead in its various forms has been used for thousands of years, originally in cooking utensils and glazes and more recently in many industrial and commercial applications. However, lead is a potent, potentially deadly toxin that damages many organs in the body and can affect all animals, including humans. By the mid 1990s, lead had been removed from many products in the United States, such as paint and fuel, but it is still commonly used in ammunition for hunting upland game birds, small mammals, and large game animals, as well as in fishing tackle. Wild birds, such as mourning doves, bald eagles, California condors, and loons, can die from the ingestion of one lead shot, bullet fragment, or sinker. According to a recent study on loon mortality, nearly half of adult loons found sick or dead during the breeding season in New England were diagnosed with confirmed or suspected lead poisoning from ingestion of lead fishing weights. Recent regulations in some states have restricted the use of lead ammunition on certain upland game hunting areas, as well as lead fishing tackle in areas frequented by common loons and trumpeter swans. A variety of alternatives to lead are available for use in hunting, shooting sports, and fishing activities.

  20. High temperature superconductor current leads

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. (Hinsdale, IL); Poeppel, Roger B. (Glen Ellyn, IL)

    1995-01-01

    An electrical lead having one end for connection to an apparatus in a cryogenic environment and the other end for connection to an apparatus outside the cryogenic environment. The electrical lead includes a high temperature superconductor wire and an electrically conductive material distributed therein, where the conductive material is present at the one end of the lead at a concentration in the range of from 0 to about 3% by volume, and at the other end of the lead at a concentration of less than about 20% by volume. Various embodiments are shown for groups of high temperature superconductor wires and sheaths.

  1. Lead-free primary explosives

    Science.gov (United States)

    Huynh, My Hang V.

    2010-06-22

    Lead-free primary explosives of the formula (cat).sub.Y[M.sup.II(T).sub.X(H.sub.2O).sub.6-X].sub.Z, where T is 5-nitrotetrazolate, and syntheses thereof are described. Substantially stoichiometric equivalents of the reactants lead to high yields of pure compositions thereby avoiding dangerous purification steps.

  2. Experience with intravascular lead extraction

    Institute of Scientific and Technical Information of China (English)

    MA Jian; TANG Kai; WANG Fang-zheng; ZHANG Shu; HUANG Cong-xin

    2005-01-01

    @@ With the increase of clinical use of cardiac pacemaker, a certain kinds of severe leads-related complications (especially infection) have presented in a few patients who underwent pacemaker implantation. The best way to manage this problem is to remove the transvenous leads.1,2 The technique for percutaneous removal of transvenous leads have undergone considerable development in western countries over the past 2 decades. However, there was scarce data on the application of this technique in China. This article reports the results of transvenous extraction of 171 permanent pacemaker leads with the standard lead extraction devices and intravascular countertraction technique during the period from January 1996 to May 2005 in the Center of Arrhythmia Diagnosis and Treatment, Fu Wai Hospital, Beijing, China.

  3. Lead arthropathy: a cause of delayed onset lead poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Peh, W.C.G. [Dept. of Diagnostic Radiology, Univ. of Hong Kong, Queen Mary Hospital (Hong Kong); Reinus, W.R. [Mallinckrodt Inst. of Radiology, Univ. School of Medicine, St. Louis, MO (United States)

    1995-07-01

    Patients who suffer gun shot wounds often have retained bullet fragments within their bodies. These are usually of no clinical consequence. We describe three patients with retained bullets within their hip joints. One of these patients, who had extensive ground intra-articular bullet fragments and secondary osteoarthritis of the hip, presented with signs, symptoms, and laboratory data consistent with lead intoxication. The bullet und metallic fragments were removed surgically with good clinical response. Two patients whose bullets were implanted entirely within the femoral head and whose joints showed smaller degrees of lead fragmentation had no symptoms of lead intoxication. The degree of intra-articular fragmentation of the bullet and the surface area of lead exposed to synovial fluid are emphasized as decisive factors with respect to appropriate therapy. (orig.)

  4. Lead levels of Culex mosquito larvae inhabiting lead utilizing factory

    Institute of Scientific and Technical Information of China (English)

    Kitvatanachai; S; Apiwathnasorn; C; Leemingsawat; S; Wongwit; W; Overgaard; HJ

    2011-01-01

    Objective:To determine lead level primarily in Culex quinquefasciatus(Cx.quinquefasciatus), and Culex gelidus(Cx.gelidus) larvae inhabiting lead consuming factories,and to putatively estimate eco-toxicological impact of effluents from the firms.Methods:Third instars larvae were sampled by standard dipping method and lead concentrations in the larvae and their respective surrounding factory aquatic environments were determined through standard atomic absorption spectrophotometry(AAS).Results:Cx.quinquefasciatus was the most abundant species followed by Cx.gelidus.The levels of lead were higher in the Cx.quinquefasciatus(1.08-47.47μg/g),than in the wastewaters surface(0.01-0.78 μg/mL) from the factories or closer areas around factories. Other species were not reaching the.criteria for lead determination.Conclusions:The Cx. quinquefasciatus larvae can bio-accumulate the metal and can potentially serve as a biomarker of lead contamination,to complemente conventional techniques.

  5. Lead- induced genotoxicity in wheat

    Directory of Open Access Journals (Sweden)

    Elena Truta

    2010-02-01

    Full Text Available The changes induced in cytogenetic parameters from root meristems of Triticum aestivum cv. Maruca seedlings have been studied after treatment with lead acetate and lead nitrate solutions, at four concentrations (10, 25, 50, 100 μM containing 2.07, 5.18, 10.36, respectively 20.72 μg ml-1 Pb2+. Lead induced mitosis disturbances in root meristematic cells of wheat seedlings, expressed mainly in decrease of mitotic index and changes in preponderance of division phases. This heavy metal has genotoxic effects, expressed in the occurrence of many chromosomal aberrations in all Pb2+ treated variants. Pb2+ nitrate shows a more pronounced genotoxic potential than lead acetate trihydrate.

  6. Lead outside your comfort zone.

    Science.gov (United States)

    Frisina, M E

    2001-11-01

    Successful leaders use their passion, values, and personal mission to create and maintain influence. Learn to define and develop a context that allows you to successfully lead nursing and non-nursing departments.

  7. Determination of Lead by Electrochemistry

    Institute of Scientific and Technical Information of China (English)

    HE YuFeng; ZHANG Zhang; MA YongJun; KANG JingWan

    2001-01-01

    @@ Lead is one of the poisonous trace element for human body. It is important to find a way for measuring content of lead. Deternination of lead by electrochemistry is one of a method[1]. In this paper, lead is determined by single-sweep polarography. The absorption behavior of meso-tetra (4-sulfonylphenyl) porphyrin (H2TPPS4) complex with lead ion has also been studied.In Na2B4O7-NaOH solution with pH=l 0.5, the reduction peaks of the ligand are P1 (Ep1=-0.38V), P2 (Ep2=-1.04V), which potentials are obtained vs. S.C.E. When lead ion has been added into above solution. The peak current of P1 and P2 decrease, and a new reduction peak P3 (Ep3=-1.10 V) appears. It shows that the TPPS4-Pb(Ⅱ) complex forms,and this method can be applied to study the complex.

  8. Determination of Lead by Electrochemistry

    Institute of Scientific and Technical Information of China (English)

    HE; YuFeng

    2001-01-01

    Lead is one of the poisonous trace element for human body. It is important to find a way for measuring content of lead. Deternination of lead by electrochemistry is one of a method[1]. In this paper, lead is determined by single-sweep polarography. The absorption behavior of meso-tetra (4-sulfonylphenyl) porphyrin (H2TPPS4) complex with lead ion has also been studied.In Na2B4O7-NaOH solution with pH=l 0.5, the reduction peaks of the ligand are P1 (Ep1=-0.38V), P2 (Ep2=-1.04V), which potentials are obtained vs. S.C.E. When lead ion has been added into above solution. The peak current of P1 and P2 decrease, and a new reduction peak P3 (Ep3=-1.10 V) appears. It shows that the TPPS4-Pb(Ⅱ) complex forms,and this method can be applied to study the complex.……

  9. Leading to distraction: Driver distraction, lead car, and road environment.

    Science.gov (United States)

    Kountouriotis, G K; Merat, N

    2016-04-01

    Driver distraction is strongly associated with crashes and near-misses, and despite the attention this topic has received in recent years, the effect of different types of distracting task on driving performance remains unclear. In the case of non-visual distractions, such as talking on the phone or other engaging verbal tasks that do not require a visual input, a common finding is reduced lateral variability in steering and gaze patterns where participants concentrate their gaze towards the centre of the road and their steering control is less variable. In the experiments presented here, we examined whether this finding is more pronounced in the presence of a lead car (which may provide a focus point for gaze) and whether the behaviour of the lead car has any influence on the driver's steering control. In addition, both visual and non-visual distraction tasks were used, and their effect on different road environments (straight and curved roadways) was assessed. Visual distraction was found to increase variability in both gaze patterns and steering control, non-visual distraction reduced gaze and steering variability in conditions without a lead car; in the conditions where a lead car was present there was no significant difference from baseline. The lateral behaviour of the lead car did not have an effect on steering performance, a finding which indicates that a lead car may not necessarily be used as an information point. Finally, the effects of driver distraction were different for straight and curved roadways, indicating a stronger influence of the road environment in steering than previously thought.

  10. Lead extraction. Indications and techniques.

    Science.gov (United States)

    Byrd, C L; Schwartz, S J; Hedin, N

    1992-11-01

    Each of the extraction techniques and their ancillary tools was reported as used successfully; however, until now, no technique has been successful when used in more than a few isolated instances. The technique for intravascular countertraction and the associated tools described in this paper were devised and selected in an attempt to develop one technique to be used on all patients, with all types of leads, and with a very low complication rate. Its versatility permitted single or multiple lead extractions combined with the precision of selecting and extracting a specific lead. In our experience, as well as the experience of others, the techniques described in this paper have proved to be superior by minimizing the inherent risk and morbidity, allowing us to expand the indications for lead removal beyond septicemia and free-floating leads, to include infection, abandonment of pockets, and replacement of malfunctioning or fractured leads. Intravascular countertraction was a consistently safe and efficacious method of removing transvenous pacemaker leads regardless of the duration of the implant, thus permitting extractions in patients not considered candidates for a more extensive surgical procedure. Intravascular countertraction encompasses surgical and fluoroscopic techniques possessed by most physicians experienced in pacemaker and automatic implantable cardioverter defibrillator implants. However, there is a learning curve, predicating caution for the inexperienced physician. In addition, advanced surgical skills may be needed in handling associated conditions such as debridement and primary closure of chronically inflamed tissues, especially in submuscular pockets and sinus tracts in the neck. Although the potential for a cardiovascular complication is small, it does exist, and cardiovascular surgical backup is a recommended precaution.

  11. Lead poisoning by contaminated flour.

    Science.gov (United States)

    Hershko, C; Eisenberg, A; Avni, A; Grauer, F; Acker, C; Hamdallah, M; Shahin, S; Moreb, J; Richter, E; Weissenberg, E

    1989-01-01

    Between October 1982 and June 1983, 43 patients were identified with symptomatic lead poisoning in three Arab villages of the Nablus district. Because of the clustering of clinical poisoning by household units, investigation was focussed on potential sources common to all members of the households. After excluding water, olive oil and a variety of foodstuff, lead in high concentrations was discovered in locally ground flour in all affected households. The source of poisoning was lead poured into the fissures between the metal housing and the driveshaft of the millstone. Significant lead contamination of freshly ground flour was demonstrated in 23% of the 146 community flour mills operating in West Bank villages. Since the completion of these studies, similar outbreaks of lead poisoning caused by contaminated flourmills have been identified in the Upper Galilee and in Spain. As the methods of milling in the Mediterranean area are similar, a coordinated international effort is needed in order to eliminate this health hazard from countries where similar community stone mills are still in use.

  12. Efficient and lightweight current leads

    Science.gov (United States)

    Bromberg, L.; Dietz, A. J.; Michael, P. C.; Gold, C.; Cheadle, M.

    2014-01-01

    Current leads generate substantial cryogenic heat loads in short length High Temperature Superconductor (HTS) distribution systems. Thermal conduction, as well as Joule losses (I2R) along the current leads, comprises the largest cryogenic loads for short distribution systems. Current leads with two temperature stages have been designed, constructed and tested, with the goal of minimizing the electrical power consumption, and to provide thermal margin for the cable. We present the design of a two-stage current lead system, operating at 140 K and 55 K. This design is very attractive when implemented with a turbo-Brayton cycle refrigerator (two-stage), with substantial power and weight reduction. A heat exchanger is used at each temperature station, with conduction-cooled stages in-between. Compact, efficient heat exchangers are challenging, because of the gaseous coolant. Design, optimization and performance of the heat exchangers used for the current leads will be presented. We have made extensive use of CFD models for optimizing hydraulic and thermal performance of the heat exchangers. The methodology and the results of the optimization process will be discussed. The use of demountable connections between the cable and the terminations allows for ease of assembly, but require means of aggressively cooling the region of the joint. We will also discuss the cooling of the joint. We have fabricated a 7 m, 5 kA cable with second generation HTS tapes. The performance of the system will be described.

  13. Chronic lead intoxication; Chronische Bleiintoxikation

    Energy Technology Data Exchange (ETDEWEB)

    Wieseler, B.; Leng, G. [Duesseldorf Univ. (Germany). Inst. fuer Hygiene; Lenz, S.; Schultz, C. [Klinikum Remscheid GmbH, Remscheid (Germany); Wilhelm, M. [Bochum Univ. (Germany). Inst. fuer Hygiene, Sozial- und Umweltmedizin

    1999-02-01

    The case of a female 68 years old patient is described. Here, a chronic lead intoxication was diagnosed after a two year old medical history with increasing attacks of colic-like abdominal pain often described as life-threatening. After repeated hospitalizations and intensive search for the cause of the symptoms, porphyria and anemia was found to be a sign of a chronic lead poisoning. The blood lead concentrations were always about a level of 600 {mu}g/L. The source of exposure could not be found by now. Neither home inspection nor environmental investigations have shown a recent source of lead intake by the patient. However, a possible occupational source of lead exposure at a blast furnace was established by anamnesis for 1952 to 1962. Thus, osteoporosis induced lead mobilisation was suspected. Noticeable are the results of the six abdominal survey radiographies taken during hospitalization within one year; three radiographies were taken following clinical admission and three before discharge of the patient. In comparison, the course shows a chronic relapsing alimentary supply from metallic particles of unknown genesis. The patient was treated with the sodium salt of 2,3-dimercapto-1-propansulfonic acid (DMPS, Dimaval{sup TM}). She was free of complain afterwards. Following therapy, the blood lead concentrations fell under a level of 400 {mu}m/L, but after several weeks the lead level raised up to the original level of 600 {mu}g/L. (orig.) [Deutsch] Es wird eine 68jaehrige Patientin vorgestellt, bei der nach fast zweijaehriger Krankengeschichte, die gekennzeichnet war durch rezidivierende, teils als lebensbedrohlich geschilderte Bauchkoliken, eine chronische Bleiintoxikation diagnostiziert wurde. Erst nach wiederholten stationaeren Krankenhausaufenthalten mit intensiver Suche nach der Krankheitsursache wurden das Krankheitsbild und die Laborwerte durch Zusatzuntersuchungen ergaenzt, so dass sich in der festgestellten Porphyrie und Anaemie die Diagnose der

  14. OPAL 96 Blocks Lead Glass

    CERN Multimedia

    This array of 96 lead glass bricks formed part of the OPAL electromagnetic calorimeter. One half of the complete calorimeter is shown in the picture above. There were 9440 lead glass counters in the OPAL electromagnetic calorimeter. These are made of Schott type SF57 glass and each block weighs about 25 kg and consists of 76% PbO by weight. Each block has a Hamamatsu R2238 photomultiplier glued on to it. The complete detector was in the form of a cylinder 7m long and 6m in diameter. It was used to measure the energy of electrons and photons produced in LEP interactions.

  15. OPAL Various Lead Glass Blocks

    CERN Multimedia

    These lead glass blocks were part of a CERN detector called OPAL (one of the four experiments at the LEP particle detector). OPAL uses some 12 000 blocks of glass like this to measure particle energies in the electromagnetic calorimeter. This detector measured the energy deposited when electrons and photons were slowed down and stopped.

  16. How to lead complex situations

    DEFF Research Database (Denmark)

    Hansen, Michael Pingel

    2013-01-01

    The military leader is experiencing increasingly more complex situations, whether it is as leader in a foreign combat environment or in the home-based public administration. Complex situations like these call for a special set of managerial responses and a special way of leading organisations...

  17. Leading in a Technological Age

    Science.gov (United States)

    Yadgir, Sheri A.

    2011-01-01

    Technology is advancing more rapidly than at any time in history since the beginning of the Industrial Revolution. In fact, experts say that the world is leaving the Industrial Age of the 20th century and entering an Information Age that will lead into the future. These advances mean that important changes are being made in all areas of life--and…

  18. Electrokinetics removal of lead from lead-contaminated red soils

    Institute of Scientific and Technical Information of China (English)

    刘云国; 李欣; 曾光明; 黄宝荣; 张慧智

    2003-01-01

    Ex-situ electroremediation tests were conducted on the lead-contaminated red soils to find out the optimum condition for the most efficient removal of lead pollution from the red soil,and to examine the relation of the pH of the soil with the electroremediation efficiency.The results show that the electroremediation technology is efficient to remedy Pb contaminated red soils,and the removal efficiency can be enhanced by controlling pH value in the cathode reservoir with HNO3.The average removal efficiency of Pb is enhanced from 24.5% to 79.5%,and the energy consumption reaches 285kW·h per m3 red soil.

  19. IMPORTANCE OF 15 LEAD ECG

    Directory of Open Access Journals (Sweden)

    Bhargav

    2014-10-01

    Full Text Available BACKGROUND AND OBJECTIVES: Posterior wall myocardial infarction is not uncommon acute myocardial infarction and has got its own therapeutic and prognostic implications. Management of Posterior wall myocardial infarction differs from inferior wall myocardial infarction alone. The presence of posterior wall myocardial infarction is known to increase the incidence of cardiogenic shock, arrhythmias and conduction blocks in case of myocardial infarction. Hence the present study was taken up to find out the incidence, clinical profile and complications of posterior wall myocardial infarction in a rural hospital using simple non-invasive investigations like 15 lead electrocardiography and echocardiography. METHODS: A prospective study was conducted on 50 patients of inferior wall myocardial infarction out of 228 Acute Myocardial Infarction proved by ECG standard and posterior leads (v7, v8, v9 were taken at the time of admission and repeated as necessary. A detailed case history was taken and a detailed physical examination was done at the time of admission and during follow up. For recording ECG 12 lead (3 standard leads, 3 augmented limb leads, 6 precordial leads machine was used. The recordings were made at 25 mm/ sec. speed and 1mV=10mm. Posterior leads were taken by using 3 precordial leads fixing on the posterior axillary (v7, infrascapular (v8 and paraspinal (v9 regions all in a same line with the 5th ICS anteriorly. RESULTS: Out of 50 cases of inferior wall myocardial infarction (IWMI studied only 13 (26% had ST elevation in posterior leads indicating posterior wall myocardial infarction (PWMI. Our study showed that complications and mortality was higher in patients of IWMI with PWMI compared to IWMI without PWMI. Out of 50 patients 33 (66% were males indicating a male predominance. Syncope was present in 18% of PWMI and 14% in overall IWMI. Palpitation was seen in 53% of PWMI and 21% of IWMI without PWMI. Smoking history was present in 14% of

  20. Lead time TTO: leading to better health state valuations?

    Science.gov (United States)

    Attema, Arthur E; Versteegh, Matthijs M; Oppe, Mark; Brouwer, Werner B F; Stolk, Elly A

    2013-04-01

    Preference elicitation tasks for better than dead (BTD) and worse than dead (WTD) health states vary in the conventional time trade-off (TTO) procedure, casting doubt on uniformity of scale. 'Lead time TTO' (LT-TTO) was recently introduced to overcome the problem. We tested different specifications of LT-TTO in comparison with TTO in a within-subject design. We elicited preferences for six health states and employed an intertemporal ranking task as a benchmark to test the validity of the two methods. We also tested constant proportional trade-offs (CPTO), while correcting for discounting, and the effect of extending the lead time if a health state is considered substantially WTD. LT-TTO produced lower values for BTD states and higher values for WTD states. The validity of CPTO varied across tasks, but it was higher for LT-TTO than for TTO. Results indicate that the ratio of lead time to disease time has a greater impact on results than the total duration of the time frame. The intertemporal ranking task could not discriminate between TTO and LT-TTO.

  1. Lead and Drinking Water from Private Wells

    Science.gov (United States)

    ... type="submit" value="Submit" /> Healthy Water Home Lead and Drinking Water from Private Wells Recommend on ... remove lead from my drinking water? What is lead? Lead is a naturally occurring bluish-gray metal ...

  2. Leading Hadron Production at HERA

    Directory of Open Access Journals (Sweden)

    Buniatyan Armen

    2013-06-01

    Full Text Available Data from the recent measurements of very forward baryon and photon production with the H1 and ZEUS detectors at electron-proton collider HERA are presented and compared to the theoretical calculations and Monte Carlo models. Results are presented of the production of leading protons, neutrons and photons in deep inelastic scattering (ep → e' pX, ep → e'nX, ep → e'γX as well as the leading neutron production in the photoproduction of dijets (ep → ejjXn. The forward baryon and photon results from the H1 and ZEUS Experiments are compared also with the models of the hadronic interactions of high energy Cosmic Rays. The sensitivity of the HERA data to the differences between the models is demonstrated.

  3. Leading Edge Device Aerodynamic Optimization

    Directory of Open Access Journals (Sweden)

    Marius Gabriel COJOCARU

    2015-12-01

    Full Text Available Leading edge devices are conventionally used as aerodynamic devices that enhance performances during landing and in some cases during takeoff. The need to increase the efficiency of the aircrafts has brought the idea of maintaining as much as possible a laminar flow over the wings. This is possible only when the leading edge of the wings is free from contamination, therefore using the leading edge devices with the additional role of shielding during takeoff. Such a device based on the Krueger flap design is aerodynamically analyzed and optimized. The optimization comprises three steps: first, the positioning of the flap such that the shielding criterion is kept, second, the analysis of the flap size and third, the optimization of the flap shape. The first step is subject of a gradient based optimization process of the position described by two parameters, the position along the line and the deflection angle. For the third step the Adjoint method is used to gain insight on the shape of the Krueger flap that will extend the most the stall limit. All these steps have been numerically performed using Ansys Fluent and the results are presented for the optimized shape in comparison with the baseline configuration.

  4. Lead Isotopes in Highway Runoff

    Science.gov (United States)

    Ferreira, M.; Lau, S.; Green, P. G.; Stenstrom, M. K.

    2011-12-01

    Lead (Pb) isotopes have been used extensively to study the provenance of lead pollution on air, water, and sediments. In this study, we measured Pb isotopes and Pb aqueous concentration in highway runoff in three west Los Angeles sites. Those three sites, part of a long-term study sponsored by the California Department of Transportation, represent small catchment areas, and host heavy traffic. In addition, there were no inputs of sand or salt to the highway because the sites are almost completely impervious and also due to the lack of snow to be controlled. Highway runoff from the three sites was collected for 7 storms during the 2004-2005 Winter. Grab samples were collected every 15 minutes during the first hour, and hourly afterwards. A total of 202 samples were collected and filtered into five size fractions (100μm). Aqueous concentration of Pb range from 0.08μg/L to 46.95μg/L (7.98±10.89μg/L) and it is not correlated with any of the lead isotope ratios. The 208Pb/206Pb ratio ranges from 1.983 to 2.075 (2.024±0.026) and there is no statistical difference for the mean value of the 208Pb/206Pb ratio for the four particulate size fractions (0.45-8μm, 8-20μm, 20-100μm, >100μm). However, the 208Pb/206Pb ratio of nearby soils yield 2.060±0.021 and it is statistically different from the ratios obtained for the highway runoff. This hints that the lead present in highway runoff does not come from local soils. The 207Pb/206Pb ratio ranges from 0.804 to 0.847 (0.827±0.011) and there is no statistical difference for the mean value of the 207Pb/206Pb ratio for the four particulate size fractions (0.45-8μm, 8-20μm, 20-100μm, >100μm). Surprisingly, there is also no statistical difference with the 207Pb/206Pb ratio of nearby soils (0.833±0.009).

  5. Relational Leading and Dialogic Process

    DEFF Research Database (Denmark)

    Hansen, Lone Hersted

    and knowledge building as related to relational leading. The practices developed in the thesis research demonstrate that it is possible to create organizational learning and development through collaborative, dialogic practices in groups and teams, for instance combined with the use of roleplaying. In the work...... with the thesis, dialogically based practices inspired by action research with the aim to enhance collaborative knowledge building, reflexivity and dialogical skills in groups and teams were carried out, analyzed and documented. Participants included school principals, leaders of kindergartens, teachers...

  6. All Roads Lead To Rome

    CERN Document Server

    Li, Xin

    2011-01-01

    This short article presents a class of projection-based solution algorithms to the problem considered in the pioneering work on compressed sensing - perfect reconstruction of a phantom image from 22 radial lines in the frequency domain. Under the framework of projection-based image reconstruction, we will show experimentally that several old and new tools of nonlinear filtering (including Perona-Malik diffusion, Total-Variation diffusion, Translation-Invariant thresholding and SA-DCT thresholding) all lead to perfect reconstruction of the phantom image.

  7. Current leads and magnetic bearings

    Science.gov (United States)

    Hull, J. R.

    1993-10-01

    Since the discovery of high temperature superconductors (HTS's), Argonne National Laboratory (ANL) has been active in a broad spectrum of activities in developing these materials for applications. Work at every stage of development has involved industrial collaboration in order to accelerate commercialization. While most of the development work has been devoted to improving the properties of current-carrying wires, some effort has been devoted to applications that can utilize HTS's with properties available now or in the near future. In this paper, advances made in the area of current leads and magnetic bearings are discussed.

  8. Lead-nickel electrochemical batteries

    CERN Document Server

    Glaize, Christian

    2012-01-01

    The lead-acid accumulator was introduced in the middle of the 19th Century, the diverse variants of nickel accumulators between the beginning and the end of the 20th Century. Although old, these technologies are always very present on numerous markets. Unfortunately they are still not used in optimal conditions, often because of the misunderstanding of the internal electrochemical phenomena.This book will show that batteries are complex systems, made commercially available thanks to considerable amounts of scientific research, empiricism and practical knowledge. However, the design of

  9. Target engagement in lead generation.

    Science.gov (United States)

    Durham, Timothy B; Blanco, Maria-Jesus

    2015-03-01

    The pharmaceutical industry is currently facing multiple challenges, in particular the low number of new drug approvals in spite of the high level of R&D investment. In order to improve target selection and assess properly the clinical hypothesis, it is important to start building an integrated drug discovery approach during Lead Generation. This should include special emphasis on evaluating target engagement in the target tissue and linking preclinical to clinical readouts. In this review, we would like to illustrate several strategies and technologies for assessing target engagement and the value of its application to medicinal chemistry efforts.

  10. All roads lead to Rome

    DEFF Research Database (Denmark)

    Ottosen, Thorsten Jørgen; Vomlel, Jiri

    2012-01-01

    for existing methods to use the treewidth criterion for optimality of a triangulation. However, this criterion may lead to a somewhat harder inference problem than the total table size criterion. We therefore investigate new methods for depth-first search and best-first search for finding optimal total table...... is generic in the sense that it can be used with other algorithms than just Bron-Kerbosch. The algorithms for finding optimal triangulations are mainly supposed to be off-line methods, but they may form the basis for efficient any-time heuristics. Furthermore, the methods make it possible to evaluate...

  11. All roads lead to Meyrin

    CERN Multimedia

    Communication locale

    2011-01-01

    Tous les chemins mènent à Meyrin - All roads lead to Meyrin From 29 September to 16 October, 2011, come to the Salle Antoine Verchère in Meyrin for Tous les chemins mènent à Meyrin. The celebration will include an exposition as well as a theatrical performance about Meyrin, the first satellite city in Switzerland. With the help of the memories and testimonies from the people of Meyrin, Tous les chemins mènent à Meyrin is putting the collective memories of the commune on display. It is an occasion for everyone, whether you're from near or far, to find out how all the roads lead to Meyrin.  Salle Antoine-Verchère Route de Meyrin 294 – 1217 Meyrin Tram 18 – Stop: Meyrin Village Thursdays / Fridays / Saturdays at 8pm Sundays at 5pm Regular ticket: CHF 15.- Concession ticket (students, chômeurs, AVS, AI): CHF 12.- Children up to 16: CHF 10.- Family ticket: CHF 35.-

  12. Distribution of lead and silver under lead blast furnace conditions

    Directory of Open Access Journals (Sweden)

    Pérez, M.

    2012-06-01

    Full Text Available Two experimental studies of metal solubility in slags were carried out at 1473 K (1200 °C. In the first one the solubility of lead in the PbO-ZnO-CaO-SiO2-“Fe2O3” slag system under a reducing atmosphere (PCO/PCO2 = 2.45 was studied. In the second part, slags of the CaO-SiO2-“Fe2O3” system were equilibrated with Pb - 1.3 mass % Ag alloys under an inert atmosphere. In both cases the CaO/SiO2 mass ratio was from 1.0 to 1.6 and Fe/SiO2 mass ratio was 1.1 and 1.7. The lead solubility in the slags of both experimental parts diminishes with increasing the slag basicity (CaO/SiO2 and diminishing the Fe/SiO2 ratio. Lead oxide is the only compound that can be reduced under the reducing atmosphere and at the temperature at the tuyeres level, 1473 K. Silver solubility in slags decreases with increasing both CaO/SiO2 and Fe/SiO2 ratios in the slags of the CaO-SiO2-“Fe2O3” system.

    Se realizaron dos estudios experimentales de solubilidad de metal en escorias a 1.473 K (1.200 °C. En el primero se estudió la solubilidad de plomo en el sistema PbO-ZnO-CaO-SiO2-“Fe2O3” bajo una atmósfera reductora (PCO/PCO2 = 2,45. En la segunda parte, escorias del sistema CaO-SiO2-“Fe2O3” fueron equilibradas con aleaciones Pb - 1,3 % Ag en atmósfera inerte. En ambos casos la relación CaO/SiO2 fue variada de 1.0 a 1.6 y la relación Fe/SiO2 fue de 1,1 y 1,7. La solubilidad de plomo en las escorias de ambas etapas experimentales disminuye con el incremento de la basicidad (CaO/SiO2 y la disminución de la relación Fe/SiO2. El óxido de plomo es el único compuesto que puede ser reducido bajo la atmósfera reductora y a la temperatura en el nivel de las toberas del horno alto, 1.473 K. La solubilidad de la plata en la escoria decrece con el aumento de las relaciones CaO/SiO2 y Fe/SiO2 en las escorias del sistema CaO-SiO2-“Fe2O3”.

  13. Anti-cancer Lead Molecule

    KAUST Repository

    Sagar, Sunil

    2014-04-17

    Derivatives of plumbagin can be selectively cytotoxic to breast cancer cells. Derivative `A` (Acetyl Plumbagin) has emerged as a lead molecule for testing against estrogen positive breast cancer and has shown low hepatotoxicity as well as overall lower toxicity in nude mice model. The toxicity of derivative `A` was determined to be even lower than vehicle control (ALT and AST markers). The possible mechanism of action identified based on the microarray experiments and pathway mapping shows that derivative `A` could be acting by altering the cholesterol-related mechanisms. The low toxicity profile of derivative `A` highlights its possible role\\'as future anti-cancer drug and/or as an adjuvant drug to reduce the toxicity of highly toxic chemotherapeutic\\'drugs

  14. Lead sulphide nanocrystal photodetector technologies

    Science.gov (United States)

    Saran, Rinku; Curry, Richard J.

    2016-02-01

    Light detection is the underlying principle of many optoelectronic systems. For decades, semiconductors including silicon carbide, silicon, indium gallium arsenide and germanium have dominated the photodetector industry. They can show excellent photosensitivity but are limited by one or more aspects, such as high production cost, high-temperature processing, flexible substrate incompatibility, limited spectral range or a requirement for cryogenic cooling for efficient operation. Recently lead sulphide (PbS) nanocrystals have emerged as one of the most promising new materials for photodetector fabrication. They offer several advantages including low-cost manufacturing, solution processability, size-tunable spectral sensitivity and flexible substrate compatibility, and they have achieved figures of merit outperforming conventional photodetectors. We review the underlying concepts, breakthroughs and remaining challenges in photodetector technologies based on PbS nanocrystals.

  15. [XANES study of lead speciation in duckweed].

    Science.gov (United States)

    Chu, Bin-Bin; Luo, Li-Qiang; Xu, Tao; Yuan, Jing; Sun, Jian-Ling; Zeng, Yuan; Ma, Yan-Hong; Yi, Shan

    2012-07-01

    Qixiashan lead-zinc mine of Nanjing was one of the largest lead zinc deposits in East China Its exploitation has been over 50 years, and the environmental pollution has also been increasing. The lead concentration in the local environment was high, but lead migration and toxic mechanism has not been clear. Therefore, biogeochemistry research of the lead zinc mine was carried out. Using ICP-MS and Pb-L III edge XANES, lead concentration and speciation were analyzed respectively, and duckweed which can tolerate and enriched heavy metals was found in the pollution area. The results showed that the lead concentration of duckweed was 39.4 mg x kg(-1). XANES analysis and linear combination fit indicated that lead stearate and lead sulfide accounted for 65% and 36.9% respectively in the lead speciation of duckweed, suggesting that the main lead speciation of duckweed was sulfur-containing lead-organic acid.

  16. The identification of lead ammunition as a source of lead exposure in First Nations: The use of lead isotope ratios

    Energy Technology Data Exchange (ETDEWEB)

    Tsuji, Leonard J.S. [Department of Environment and Resource Studies, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada)], E-mail: ljtsuji@fes.uwaterloo.ca; Wainman, Bruce C. [Faculty of Health Sciences, McMaster University, Hamilton, Ontario, L8N 3Z5 (Canada); Martin, Ian D. [Department of Environment and Resource Studies, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Sutherland, Celine [Attawapiskat First Nation Health Services, Attawapiskat, Ontario, P0L 1A0 (Canada); Weber, Jean-Philippe; Dumas, Pierre [Centre de toxicologie, Institut national de sante publique du Quebec, Quebec City, Quebec, G1V 5B3 (Canada); Nieboer, Evert [Faculty of Health Sciences, McMaster University, Hamilton, Ontario, L8N 3Z5 (Canada); Institute of Community Medicine, University of Tromso, Tromso N-9037 (Norway)

    2008-04-15

    The use of lead shotshell to hunt water birds has been associated with lead-contamination in game meat. However, evidence illustrating that lead shotshell is a source of lead exposure in subsistence hunting groups cannot be deemed definitive. This study seeks to determine whether lead shotshell constitutes a source of lead exposure using lead isotope ratios. We examined stable lead isotope ratios for lichens, lead shotshell and bullets, and blood from residents of Fort Albany and Kashechewan First Nations, and the City of Hamilton, Ontario, Canada. Data were analyzed using ANOVA and regression analyses. ANOVA of isotope ratios for blood revealed significant differences with respect to location, but not sex. Hamilton differed from both Kashechewan and Fort Albany; however, the First Nations did not differ from each other. ANOVA of the isotope ratios for lead ammunition and lichens revealed no significant differences between lichen groups (north and south) and for the lead ammunition sources (pellets and bullets). A plot of {sup 206}Pb/{sup 204}Pb and {sup 206}Pb/{sup 207}Pb values illustrated that lichens and lead ammunition were distinct groupings and only the 95% confidence ellipse of the First Nations group overlapped that of lead ammunition. In addition, partial correlations between blood-lead levels (adjusted for age) and isotope ratios revealed significant (p < 0.05) positive correlations for {sup 206}Pb/{sup 204}Pb and {sup 206}Pb/{sup 207}Pb, and a significant negative correlation for {sup 208}Pb/{sup 206}Pb, as predicted if leaded ammunition were the source of lead exposure. In conclusion, lead ammunition was identified as a source of lead exposure for First Nations people; however, the isotope ratios for lead shotshell pellets and bullets were indistinguishable. Thus, lead-contaminated meat from game harvested with lead bullets may also be contributing to the lead body burden.

  17. The identification of lead ammunition as a source of lead exposure in First Nations: the use of lead isotope ratios.

    Science.gov (United States)

    Tsuji, Leonard J S; Wainman, Bruce C; Martin, Ian D; Sutherland, Celine; Weber, Jean-Philippe; Dumas, Pierre; Nieboer, Evert

    2008-04-15

    The use of lead shotshell to hunt water birds has been associated with lead-contamination in game meat. However, evidence illustrating that lead shotshell is a source of lead exposure in subsistence hunting groups cannot be deemed definitive. This study seeks to determine whether lead shotshell constitutes a source of lead exposure using lead isotope ratios. We examined stable lead isotope ratios for lichens, lead shotshell and bullets, and blood from residents of Fort Albany and Kashechewan First Nations, and the City of Hamilton, Ontario, Canada. Data were analyzed using ANOVA and regression analyses. ANOVA of isotope ratios for blood revealed significant differences with respect to location, but not sex. Hamilton differed from both Kashechewan and Fort Albany; however, the First Nations did not differ from each other. ANOVA of the isotope ratios for lead ammunition and lichens revealed no significant differences between lichen groups (north and south) and for the lead ammunition sources (pellets and bullets). A plot of (206)Pb/(204)Pb and (206)Pb/(207)Pb values illustrated that lichens and lead ammunition were distinct groupings and only the 95% confidence ellipse of the First Nations group overlapped that of lead ammunition. In addition, partial correlations between blood-lead levels (adjusted for age) and isotope ratios revealed significant (pleaded ammunition were the source of lead exposure. In conclusion, lead ammunition was identified as a source of lead exposure for First Nations people; however, the isotope ratios for lead shotshell pellets and bullets were indistinguishable. Thus, lead-contaminated meat from game harvested with lead bullets may also be contributing to the lead body burden.

  18. The Solar System primordial lead

    Science.gov (United States)

    Blichert-Toft, Janne; Zanda, Brigitte; Ebel, Denton S.; Albarède, Francis

    2010-11-01

    Knowledge of the primordial isotope composition of Pb in the Solar System is critical to the understanding of the early evolution of Earth and other planetary bodies. Here we present new Pb isotopic data on troilite (FeS) nodules from a number of different iron meteorites: Canyon Diablo, Mundrabilla, Nantan, Seeläsgen, Toluca (IAB-IIICD), Cape York (IIIA), Mt Edith (IIIB), and Seymchan (pallasite). Lead abundances and isotopic compositions typically vary from one troilite inclusion to another, even within the same meteorite. The most primitive Pb was found in three leach fractions of two exceptionally Pb-rich Nantan troilite nodules. Its 204Pb/ 206Pb is identical to that of Canyon Diablo troilite as measured by Tatsumoto et al. [M. Tatsumoto, R.J. Knight, C.J. Allègre, Time differences in the formation of meteorites as determined from the ratio of lead-207 to lead-206, Science 180(1973) 1279-1283]. However, our measurements of 207Pb/ 206Pb and 208Pb/ 206Pb are significantly higher than theirs, as well as other older literature data obtained by TIMS, while consistent with the recent data of Connelly et al. [J.N. Connelly, M. Bizzarro, K. Thrane, J.A. Baker, The Pb-Pb age of Angrite SAH99555 revisited, Geochim. Cosmochim. Acta 72(2008) 4813-4824], a result we ascribe to instrumental mass fractionation having biased the older data. Our current best estimate of the Solar System primordial Pb is that of Nantan troilite, which has the following isotopic composition: 204Pb/ 206Pb = 0.107459(16), 207Pb/ 206Pb = 1.10759(10), and 208Pb/ 206Pb = 3.17347(28). This is slightly less radiogenic than the intercept of the bundle of isotopic arrays formed in 207Pb/ 206Pb- 204Pb/ 206Pb space by our measurements of Canyon Diablo, Nantan, Seeläsgen, Cape York, and Mundrabilla, as well as literature data, which, in spite of rather large uncertainties, suggests a common primordial Pb component for all of these meteorites. The radiogenic Pb present in most of these irons is dominantly

  19. Results from the Cooler and Lead Tests

    Energy Technology Data Exchange (ETDEWEB)

    Green, Michael A

    2010-06-10

    The report presents the results of testing MICE spectrometer magnet current leads on a test apparatus that combines both the copper leads and the high temperature superconducting (HTS) leads with a single Cryomech PT415 cooler and liquid helium tank. The current is carried through the copper leads from 300 K to the top of the HTS leads. The current is then carried through the HTS leads to a feed-through from the vacuum space to the inside of a liquid helium tank. The experiment allows one to measure the performance of both cooler stages along with the performance of the leads. While the leads were powered we measured the voltage drops through the copper leads, through the HTS leads, through spliced to the feed-through, through the feed-through and through the low-temperature superconducting loop that connects one lead to the other. Measurements were made using the leads that were used in spectrometer magnet 1A and spectrometer magnet 2A. These are the same leads that were used for Superbend and Venus magnets at LBNL. The IL/A for these leads was 5.2 x 10{sup 6} m{sup -1}. The leads turned out to be too long. The same measurements were made using the leads that were installed in magnet 2B. The magnet 2B leads had an IL/A of 3.3 x 10{sup 6} A m{sup -1}. This report discusses the cooler performance and the measured electrical performance of the lead circuit that contains the copper leads and the superconducting leads. All of the HTS leads that were installed in magnet 2B were current tested using this apparatus.

  20. Industrial flow of lead in China

    Institute of Scientific and Technical Information of China (English)

    MAO Jian-su; YANG Zhi-feng; LU Zhong-wu

    2007-01-01

    The rules on industrial flow of lead were studied for theoretical foundation of nonrenewable resource conservation and environmental improvement. A model of lead flow in lead product life cycle was developed through lead flow analysis and was used to analyze the relationship between lead product system and its environment, thus the rules on industrial flow of lead were obtained. The results show that increasing eco-efficiency will favor both resource conservation and environmental improvement. Several indices were proposed to evaluate the lead flow. As for application, the lead-flow for China in 1999 was analyzed and the reasons for low eco-efficiency were identified. In the end, some countermeasures were proposed to improve eco-efficiency, and the future lead ore consumption and environment quality were forecasted.

  1. Lead poisoning in captive wild animals

    Energy Technology Data Exchange (ETDEWEB)

    Zook, B.C.; Sauer, R.M.; Garner, F.M.

    1972-07-01

    Lead poisoning was diagnosed post-mortem in 34 simian primates, 11 parrots, and 3 Australian fruit bats at the National Zoological Park. Diagnoses were made by the finding of acid-fast intranuclear inclusion bodies in renal epithelia or hepatocytes and, in most cases, by finding excess lead in samples of liver. The estimated prevalence of lead intoxication among autopsied primates and parrots was 44% and 50% respectively. Leaded paint was found in many animal enclosures at this zoo and it was available to all the lead-poisoned animals in this study. The finding of renal intranuclear inclusion bodies in animals at several zoos, scattered reports of lead intoxication of animals dwelling in various zoos, the occurrence of leaded paint in many zoos and the high incidence of lead poisoning at this zoo, indicated that lead poisoning of zoo animals is much more common than was previously thought.

  2. Lead-Binding Proteins: A Review

    Directory of Open Access Journals (Sweden)

    Harvey C. Gonick

    2011-01-01

    Full Text Available Lead-binding proteins are a series of low molecular weight proteins, analogous to metallothionein, which segregate lead in a nontoxic form in several organs (kidney, brain, lung, liver, erythrocyte. Whether the lead-binding proteins in every organ are identical or different remains to be determined. In the erythrocyte, delta-aminolevulinic acid dehydratase (ALAD isoforms have commanded the greatest attention as proteins and enzymes that are both inhibitable and inducible by lead. ALAD-2, although it binds lead to a greater degree than ALAD-1, appears to bind lead in a less toxic form. What may be of greater significance is that a low molecular weight lead-binding protein, approximately 10 kDa, appears in the erythrocyte once blood lead exceeds 39 μg/dL and eventually surpasses the lead-binding capacity of ALAD. In brain and kidney of environmentally exposed humans and animals, a cytoplasmic lead-binding protein has been identified as thymosin β4, a 5 kDa protein. In kidney, but not brain, another lead-binding protein has been identified as acyl-CoA binding protein, a 9 kDa protein. Each of these proteins, when coincubated with liver ALAD and titrated with lead, diminishes the inhibition of ALAD by lead, verifying their ability to segregate lead in a nontoxic form.

  3. Kinetics of oil saponification by lead salts in ancient preparations of pharmaceutical lead plasters and painting lead mediums.

    Science.gov (United States)

    Cotte, M; Checroun, E; Susini, J; Dumas, P; Tchoreloff, P; Besnard, M; Walter, Ph

    2006-12-15

    Lead soaps can be found in archaeological cosmetics as well as in oil paintings, as product of interactions of lead salts with oil. In this context, a better understanding of the formation of lead soaps allows a follow-up of the historical evolution of preparation recipes and provides new insights into conservation conditions. First, ancient recipes of both pharmaceutical lead plasters and painting lead mediums, mixtures of oil and lead salts, were reconstructed. The ester saponification by lead salts is determined by the preparation parameters which were quantified by FT-IR spectrometry. In particular, ATR/FT-IR spectrometer was calibrated by the standard addition method to quantitatively follow the kinetics of this reaction. The influence of different parameters such as temperature, presence of water and choice of lead salts was assessed: the saponification is clearly accelerated by water and heating. This analysis provides chemical explanations to the historical evolution of cosmetic and painting preparation recipes.

  4. Mineral resource of the month: lead

    Science.gov (United States)

    Smith, Gerald R.

    2004-01-01

    The United States is a major producer and consumer of refined lead, representing almost one quarter of total world production and consumption. Two mines in Alaska and six in Missouri accounted for 97 percent of domestic lead production in 2002. The United States also imports enough refined lead to satisfy almost 20 percent of domestic consumption. Other major producers or consumers of refined lead in the world are Australia, Canada, China, France, Germany, Italy, Japan and the United Kingdom.

  5. Lead exposure from aluminum cookware in Cameroon

    Energy Technology Data Exchange (ETDEWEB)

    Weidenhamer, Jeffrey D.; Kobunski, Peter A. [Department of Chemistry, Geology and Physics, 401 College Ave., Ashland University, Ashland, OH 44805 (United States); Kuepouo, Gilbert [Research and Education Centre for Development (CREPD), Yaounde (Cameroon); Corbin, Rebecca W. [Department of Chemistry, Geology and Physics, 401 College Ave., Ashland University, Ashland, OH 44805 (United States); Gottesfeld, Perry, E-mail: pgottesfeld@okinternational.org [Occupational Knowledge International, San Francisco, CA (United States)

    2014-10-15

    Blood lead levels have decreased following the removal of lead from gasoline in most of the world. However, numerous recent studies provide evidence that elevated blood lead levels persist in many low and middle-income countries around the world at much higher prevalence than in the more developed countries. One potential source of lead exposure that has not been widely investigated is the leaching of lead from artisanal aluminum cookware, which is commonly used in the developing world. Twenty-nine samples of aluminum cookware and utensils manufactured by local artisans in Cameroon were collected and analyzed for their potential to release lead during cooking. Source materials for this cookware included scrap metal such as engine parts, radiators, cans, and construction materials. The lead content of this cookware is relatively low (< 1000 ppm by X-ray fluorescence), however significant amounts of lead, as well as aluminum and cadmium were released from many of the samples using dilute acetic acid extractions at boiling and ambient temperatures. Potential exposures to lead per serving were estimated to be as high as 260 μg, indicating that such cookware can pose a serious health hazard. We conclude that lead, aluminum and cadmium can migrate from this aluminum cookware during cooking and enter food at levels exceeding recommended public health guidelines. Our results support the need to regulate lead content of materials used to manufacture these pots. Artisanal aluminum cookware may be a major contributor to lead poisoning throughout the developing world. Testing of aluminum cookware in other developing countries is warranted. - Highlights: • Cookware is manufactured in Cameroon from scrap aluminum including car parts. • Twenty-nine cookware samples were evaluated for their potential to leach lead. • Boiling extractions to simulate the effects of cooking released significant lead. • Potential lead exposures per serving are estimated as high as 260 μg.

  6. Lead sources in human diet in Greenland

    DEFF Research Database (Denmark)

    Bjerregaard, Peter; Johansen, Poul; Mulvad, Gert

    2004-01-01

    Although blood lead levels have declined in Greenland, they are still elevated despite the fact that lead levels in the Greenland environment are very low. Fragments of lead shot in game birds have been suggested as an important source of dietary exposure, and meals of sea birds, particularly eid...

  7. Status of Lead Resources in China

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>In the global context, China boasts rich reserve of lead resources, up till 2009 China’s reserve of lead resources ranks second in the world,accounting for 15.19% of global total reserve.By the end of 2009, there were 1634 lead mines nationwide, up by 127 over the figure in 2008.

  8. 29 CFR 1910.1025 - Lead.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 6 2010-07-01 2010-07-01 false Lead. 1910.1025 Section 1910.1025 Labor Regulations...) OCCUPATIONAL SAFETY AND HEALTH STANDARDS (CONTINUED) Toxic and Hazardous Substances § 1910.1025 Lead. (a) Scope and application. (1) This section applies to all occupational exposure to lead, except as provided...

  9. Electrical polarization of lead bromide crystals. I

    NARCIS (Netherlands)

    Schoonman, A.; Macke, A.J.H.

    1972-01-01

    An attempt was made to measure electronic conductivity in lead bromide in equilibrium with lead, since experimental data on the cell −Pb/PbBr2/C+ in the literature are not consistent with existing theories. Combination of our results with published data for bromine-induced hole conduction in lead br

  10. Is Your Child Safe from Lead Poisoning?

    Centers for Disease Control (CDC) Podcasts

    2008-10-02

    In this podcast, Dr. Mary Jean Brown, chief of CDC's Lead Poisoning and Prevention Program, discusses the importance of testing children for lead poisoning, who should be tested, and what parents can do to prevent lead poisoning.  Created: 10/2/2008 by National Center for Environmental Health (NCEH).   Date Released: 10/2/2008.

  11. Eryptosis in lead-exposed workers

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Dorado, Itzel-Citlalli [Biochemistry Department, Centro de Investigación y Estudios Avanzados IPN, México, DF (Mexico); Hernández, Gerardo [Section of Methodology of Science, Centro de Investigación y Estudios Avanzados IPN, México, DF (Mexico); Quintanar-Escorza, Martha-Angelica [Faculty of Medicine, UJED, Durango, DGO (Mexico); Maldonado-Vega, María [CIATEC, León, GTO (Mexico); Rosas-Flores, Margarita [Biochemistry Department, Centro de Investigación y Estudios Avanzados IPN, México, DF (Mexico); Calderón-Salinas, José-Víctor, E-mail: jcalder@cinvestav.mx [Biochemistry Department, Centro de Investigación y Estudios Avanzados IPN, México, DF (Mexico)

    2014-12-01

    Eryptosis is a physiological phenomenon in which old and damaged erythrocytes are removed from circulation. Erythrocytes incubated with lead have exhibited major eryptosis. In the present work we found evidence of high levels of eryptosis in lead exposed workers possibly via oxidation. Blood samples were taken from 40 male workers exposed to lead (mean blood lead concentration 64.8 μg/dl) and non-exposed workers (4.2 μg/dl). The exposure to lead produced an intoxication characterized by 88.3% less δ-aminolevulinic acid dehydratase (δALAD) activity in lead exposed workers with respect to non-lead exposed workers. An increment of oxidation in lead exposed workers was characterized by 2.4 times higher thiobarbituric acid-reactive substance (TBARS) concentration and 32.8% lower reduced/oxidized glutathione (GSH/GSSG) ratio. Oxidative stress in erythrocytes of lead exposed workers is expressed in 192% higher free calcium concentration [Ca{sup 2+}]{sub i} and 1.6 times higher μ-calpain activity with respect to non-lead exposed workers. The adenosine triphosphate (ATP) concentration was not significantly different between the two worker groups. No externalization of phosphatidylserine (PS) was found in non-lead exposed workers (< 0.1%), but lead exposed workers showed 2.82% externalization. Lead intoxication induces eryptosis possibly through a molecular pathway that includes oxidation, depletion of reduced glutathione (GSH), increment of [Ca{sup 2+}], μ-calpain activation and externalization of PS in erythrocytes. Identifying molecular signals that induce eryptosis in lead intoxication is necessary to understand its physiopathology and chronic complications. - Graphical abstract: Fig. 1. (A) Blood lead concentration (PbB) and (B) phosphatidylserine externalization on erythrocyte membranes of non-lead exposed (□) and lead exposed workers (■). Values are mean ± SD. *Significantly different (P < 0.001). - Highlights: • Erythrocytes of lead exposed workers

  12. The relationship between environmental lead and blood lead in children: a study in environmental epidemiology

    NARCIS (Netherlands)

    Brunekreef, B.

    1985-01-01

    This study deals with the relationship between environmental lead and blood lead in children.Chapter 1 provides a summary of the environmental health aspects of lead. The occurrence of lead in the environment and in man is described; children are discussed as a population at risk for undue lead abso

  13. Lead resistance in micro-organisms.

    Science.gov (United States)

    Jarosławiecka, Anna; Piotrowska-Seget, Zofia

    2014-01-01

    Lead (Pb) is an element present in the environment that negatively affects all living organisms. To diminish its high toxicity, micro-organisms have developed several mechanisms that allow them to survive exposure to Pb(II). The main mechanisms of lead resistance involve adsorption by extracellular polysaccharides, cell exclusion, sequestration as insoluble phosphates, and ion efflux to the cell exterior. This review describes the various lead resistance mechanisms, and the regulation of their expression by lead binding regulatory proteins. Special attention is given to the Pbr system from Cupriavidus metallidurans CH34, which involves a unique mechanism combining efflux and lead precipitation.

  14. Lead toxicity update. A brief review.

    Science.gov (United States)

    Papanikolaou, Nikolas C; Hatzidaki, Eleftheria G; Belivanis, Stamatis; Tzanakakis, George N; Tsatsakis, Aristidis M

    2005-10-01

    Lead is a metal which has been associated with human activities for the last 6000 years. In ancient civilizations, uses of lead included the manufacture of kitchen utensils, trays, and other decorative articles. However, lead is also toxic to humans, with the most deleterious effects on the hemopoietic, nervous, reproductive systems and the urinary tract. The main sources of lead exposure are paints, water, food, dust, soil, kitchen utensils, and leaded gasoline. The majority of cases of lead poisoning are due to oral ingestion and absorption through the gut. Lead poisoning in adults occurs more frequently during exposure in the workplace and primarily involves the central nervous system. Symptoms of hemopoietic system involvement include microcytic, hypochromic anemia with basophilic stippling of the erythrocytes. Hyperactivity, anorexia, decreased play activity, low intelligence quotient, and poor school performance have been observed in children with high lead levels. Lead crosses the placenta during pregnancy and has been associated with intrauterine death, prematurity, and low birth weight. In 1991, the Centers for Disease Control and Prevention in the USA redefined elevated blood lead levels as those > or = 10 microg/dl and recommended a new set of guidelines for the treatment of lead levels > or =15 microg/dl.

  15. High-temperature superconducting current leads

    Science.gov (United States)

    Hull, J. R.

    1992-07-01

    The use of high-temperature superconductors (HTSs) for current leads to deliver power to devices at liquid helium temperature is near commercial realization. The use of HTSs in this application has the potential to reduce refrigeration requirements and helium boiloff to values significantly lower than the theoretical best achievable with conventional leads. Considerable advantage is achieved by operating these leads with an intermediate temperature heat sink. The HTS part of the lead can be made from pressed and sintered powder. Powder-in-tube fabrication is also possible, however, the normal metal part of the lead acts as a thermal short and cannot provide much stabilization without increasing the refrigeration required. Lead stability favors designs with low current density. Such leads can be manufactured with today's technology, and lower refrigeration results from the same allowable burnout time. Higher current densities result in lower boiloff for the same lead length, but bumout times can be very short. In comparing experiment to theory, the density of helium vapor needs to be accounted for in calculating the expected boiloff. For very low-loss leads, two-dimensional heat transfer and the state of the dewar near the leads may play a dominant role in lead performance.

  16. Validation of defibrillator lead performance registry data

    DEFF Research Database (Denmark)

    Kristensen, Anders Elgaard; Larsen, Jacob Moesgaard; Nielsen, Jens Cosedis

    2017-01-01

    intervention. The validity of the less detailed overall reasons for lead interventions commonly used to report lead performance is also excellent. These findings indicate high registry data quality appropriate for scientific analysis and industry-independent post-marketing surveillance.......AIMS: The validity of registry data on defibrillator lead performance is described only sparsely, despite its clinical importance. This study investigated the validity of defibrillator lead performance registry data in a nationwide and population-based registry. METHODS AND RESULTS: We identified.......9% (95% CI: 85.2-90.2%) with a κ value of 0.82 (95% CI:0.78-0.86) representing an almost perfect match. CONCLUSION: The validity of data on defibrillator lead performance recorded in the DPIR is excellent for the specific types of lead intervention and good for the specific reasons for defibrillator lead...

  17. Editorial: Lead Risk Assessment and Health Effects.

    Science.gov (United States)

    Mielke, Howard W

    2016-06-14

    In 1980, Clair C. Patterson stated: "Sometime in the near future it probably will be shown that the older urban areas of the United States have been rendered more or less uninhabitable by the millions of tons of poisonous industrial lead residues that have accumulated in cities during the past century". We live in the near future about which this quote expressed concern. This special volume of 19 papers explores the status of scientific evidence regarding Dr. Patterson's statement on the habitability of the environments of communities. Authors from 10 countries describe a variety of lead issues in the context of large and small communities, smelter sites, lead industries, lead-based painted houses, and vehicle fuel treated with lead additives dispersed by traffic. These articles represent the microcosm of the larger health issues associated with lead. The challenges of lead risk require a concerted global action for primary prevention.

  18. Editorial: Lead Risk Assessment and Health Effects

    Directory of Open Access Journals (Sweden)

    Howard W. Mielke

    2016-06-01

    Full Text Available In 1980, Clair C. Patterson stated: “Sometime in the near future it probably will be shown that the older urban areas of the United States have been rendered more or less uninhabitable by the millions of tons of poisonous industrial lead residues that have accumulated in cities during the past century”. We live in the near future about which this quote expressed concern. This special volume of 19 papers explores the status of scientific evidence regarding Dr. Patterson’s statement on the habitability of the environments of communities. Authors from 10 countries describe a variety of lead issues in the context of large and small communities, smelter sites, lead industries, lead-based painted houses, and vehicle fuel treated with lead additives dispersed by traffic. These articles represent the microcosm of the larger health issues associated with lead. The challenges of lead risk require a concerted global action for primary prevention.

  19. Experimental oral lead toxicity in young dogs

    Energy Technology Data Exchange (ETDEWEB)

    Stowe, H.D.; Goyer, R.A.; Krigman, M.M.; Wilson, M.; Cates, M.

    1973-02-01

    Litter-mate male pups were fed a calcium-and-phosphorus-low purified diet with and without 100 ppm of lead as lead acetate from age 6 to 18 weeks. Lead-toxic dogs exhibited cyclic but terminally severe anorexia and cachexia, significant anemia, normoblastocytosis and leukopenia within six weeks, hypoproteinemia, decreased serum albumin, ..cap alpha../sub 1/-globulin, ..beta../sub 2/-globulin, alkaline phosphatase and lactic dehydrogenase 1, elevated serum glutamic oxaloacetic and pyruvic transaminases, delayed closure of the thoracic vertebral epiphyses, lead lines in the distal radii and thoracic spinous processes, enlargement of liver, kidney, and brain, hepatic fatty metamorphosis, focal proximal renal tubular necrosis, hydropic degeneration of spermatognia, and lead inclusion body formation. Approximately 97% of the tissue lead was estimated to be skeletal; the greatest concentration of lead in the brain was found in the occipital gray matter.

  20. The lead and lead-acid battery industries during 2002 and 2007 in China

    Science.gov (United States)

    Chen, H. Y.; Li, A. J.; Finlow, D. E.

    In the past 15 years, the center of the international lead market has shifted to China. China has become the largest producer of raw and refined lead, plus the largest consumer. This paper reviews the status of the lead and lead-acid battery industries in China, including lead mining, lead refining, secondary lead production, the lead-acid battery industry, new opportunities for lead-acid batteries, and the environmental problems associated with lead and lead-acid batteries. The output of raw and refined lead has increased annually in China, and now accounts for more than 30% of the world total. As a result of a change in the Chinese government's policy regarding the export of lead, plus an increase in the price of lead, the profits of Chinese lead manufacturers were significantly reduced, the trade deficit of the Chinese lead industry increased, the operating rates of lead smelter enterprises greatly reduced, and some small enterprises were forced to shut down. At the present time, an increasing number of enterprises have begun to produce secondary lead, and the scale of production has expanded from tens of tons to tens of thousands of tons. In 2006, the output of secondary lead in China reached 700,000 tons, but outdated technology and equipment limited development of the secondary lead industry. Because of serious pollution problems, raw material shortages, and fierce price competition in the battery market, changes in the development of the lead-acid battery industry have been dramatic; approximately one thousand medium-sized and small lead-acid battery producers have been closed in the past 3 years. The output of large lead-acid battery enterprises has not been reduced, however, as a result of their manufacturing technology and equipment being comparable to those in other advanced industrial countries. In China, the flourishing development of electric bicycles, electric tricycles, and photovoltaic energy systems should provide ongoing opportunities for the

  1. Effect of subclinical lead intake on calves

    Energy Technology Data Exchange (ETDEWEB)

    Dinius, D.A.; Brinsfield, T.H.; Williams, E.E.

    1973-01-01

    Sixteen bull calves were fed a 70% concentrate diet containing no added lead, 10 ppM lead from newsprint, or 10 and 100 ppM lead from lead chromate. The diets were pelleted and fed ad libitum for 100 days. Fecal and urine samples were collected and EKG and respiration rates were monitored at 25-day intervals. At the end of the 100-day feeding trial, the calves were sacrificed and samples of skeletal muscle, cerebral cortex, liver and kidney were collected for lead analysis. Supplemental lead did not affect feed consumption nor weight gain; however, newsprint depressed both intake and gain. Neither EKG patterns, heart rate nor respiration rate were affected by dietary treatment. The percentage of ingested lead excreted in feces and urine was not significantly different among treatments. There were no significant tissue accumulations of lead from feeding newsprint or 10 ppM lead chromate; however, feeding 100 ppM lead chromate resulted in accumulations of the element in liver and kidney. Samples of cerebral cortex, liver and kidney cortex were examined by electron microscopy. Changes were not detected in the cellular ultrastructure of these tissues from either control or treated animals.

  2. Exploring How Lead Users Develop Radical Innovation

    DEFF Research Database (Denmark)

    Lettl, Christopher; Hienerth, Christoph; Gemuenden, Hans Georg

    2008-01-01

    In this study, we explore how lead users develop radical innovations outside of manufacturing firms. We analyze the transition from a very early stage of activities to the ultimate commercialization of these innovations. The focus in this context is on the initiatives undertaken by lead users...... lead users as surgeons launch entrepreneurial activities and bridge periods in which established medical equipment manufacturers would not risk investing in radical innovations. By doing so, lead users create the conditions usually provided in manufacturer-initiated lead user projects, including...... the supply of diversified knowledge, the development and coordination of a network for further development of the innovation, and initial tests of technical or market feasibility. Our findings have implications for manufacturing firms that wish to design radical innovation projects with (individual) lead...

  3. Individual variability in human tibia lead concentration.

    OpenAIRE

    Todd, A. C.; Parsons, P J; Tang, S.; Moshier, E L

    2001-01-01

    Our aims in this study were to determine proximal-distal variability in adult human tibia lead concentration via electrothermal atomization atomic absorption spectrometry (ETAAS) and to determine whether there were any differences between core and surface tibia lead concentrations. We analyzed duplicate core and surface tibia samples for lead at multiple proximal-distal sections on 10 adult human cadaver legs. Dried bone samples were digested in nitric acid using microwave-assisted heating, a...

  4. PROGRESS ON LEAD PHOTOCATHODES FOR SUPERCONDUCTING INJECTORS.

    Energy Technology Data Exchange (ETDEWEB)

    SMEDLEY, J.; RAO, T.; SEKUTOWICZ, J.; KNEISEL, P.; LANGNER, J.; STRZYZEWSKI, P.; LEFFERTS, R.; LIPSKI, A.

    2005-05-16

    We present the results of our investigation of bulk lead, along with various types of lead films, as suitable photocathode materials for superconducting RF injectors. The quantum efficiency of each sample is presented as a function of the photon energy of the incident light, from 3.9 eV to 6.5 eV. Quantum efficiencies of 0.5% have been obtained. Production of a niobium cavity with a lead-plated cathode is underway.

  5. Progress on lead photocathodes for superconducting injectors

    Energy Technology Data Exchange (ETDEWEB)

    Smedley, John; Rao, Triveni; Sekutowicz, Jacek; Kneisel, Peter; Langner, J; Strzyzewski, P; Lefferts, Richard; Lipski, Andrzej

    2005-05-16

    We present the results of our investigation of bulk lead, along with various types of lead films, as suitable photocathode materials for superconducting RF injectors. The quantum efficiency of each sample is presented as a function of the photon energy of the incident light, from 3.9 eV to 6.5 eV. Quantum efficiencies of 0.5% have been obtained. Production of a niobium cavity with a lead plated cathode is underway.

  6. Applications of Hydrofoils with Leading Edge Protuberances

    Science.gov (United States)

    2012-03-30

    APPLICATIONS OF HYDROFOILS WITH LEADING EDGE PROTUBERANCES Final Technical Report for Office of Naval Research contract...To) 03/30/2012 Final Technical Report 01-08-2008 to 31-12-2011 4. TITLE AND SUBTITLE Sa. CONTRACT NUMBER Applications of Hydrofoils with Leading...AVAILABILITY STATEMENT Approved for public release; distribution is unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT The leading edge modified hydrofoils

  7. Measurement of Lead In Drinking Water

    Science.gov (United States)

    2016-06-13

    easily monitor remediation efforts on-site in a cost effective and timely manner. 1.2 Official DoD Requirement Statement The measurement of lead in...Other Technologies Costs are best compared with current practice for determining lead levels in drinking water. Typically samples are collected and... Measurement of Lead In Drinking Water Naval Command, Control and Ocean Surveillance Center Research, Development, Test and

  8. Lead Poisoning in the World and Iran

    Directory of Open Access Journals (Sweden)

    F Azizi

    2010-03-01

    Full Text Available Lead is a relatively ubiquitous heavy metal with particular features such as resistance to corrosion, high malleability and wide variety of industrial applications. In medicine, however, it is considered as a slow-acting toxic substance affecting multiple body systems, specifically functioning as a potent neurotoxin in the central nervous system. Lead poisoning may be acute or chronic and can be due to occupational or environmental exposures. The history of lead poisoning dates back to ancient times. The present paper briefly describes the worldwide historical accounts of lead poisoning with a special focus on Iran.

  9. Advantage of a lead swimmer in drafting

    CERN Document Server

    Westerweel, J; Pennings, P; Yilmaz, B

    2016-01-01

    We present results from model tests to investigate the effect of drafting in swimming, in particular for the lead swimmer. The drag for scaled-model passive swimmers was determined accurately at Froude numbers comparable to conditions for actual human swimmers. Several positions of a draft swimmer at different separations behind and alongside the lead swimmer were investigated. It was found that a lead swimmer can experience an advantage from a draft swimmer. Several other positions of the draft swimmer relative to the frontal wave generated by the lead swimmer were also considered. These results indicate favourable and undesirable positions during passing.

  10. The energy efficiency of lead selfsputtering

    DEFF Research Database (Denmark)

    Andersen, Hans Henrik

    1968-01-01

    The sputtering efficiency (i.e. ratio between sputtered energy and impinging ion energy) has been measured for 30–75‐keV lead ions impinging on polycrystalline lead. The results are in good agreement with recent theoretical estimates. © 1968 The American Institute of Physics......The sputtering efficiency (i.e. ratio between sputtered energy and impinging ion energy) has been measured for 30–75‐keV lead ions impinging on polycrystalline lead. The results are in good agreement with recent theoretical estimates. © 1968 The American Institute of Physics...

  11. Secondary Item Procurement Lead Time Study.

    Science.gov (United States)

    1984-03-01

    NONEhhhhhh % I - 15 III& 1-- -NAION&°I° oI Ai OF .° NAIU REUONF TEST CANA -~~ 7 .. SECONDARY ITEM PROCUREMENT LEAD TIME STUDY __ LOGISTICS SYSTEMS...ASSISTANT SECRETARY OF THE AIR FORCE (RD&L) DIRECTOR, DEFENSE LOGISTICS AGENCY SUBJECT: Secondary Item Procurement Lead Time Study A recent report by the...determination of procurement lead time. A plan for the study is enclosed. In order to achieve the objectives of the procurement lead time study as well as the

  12. Analysis of lead toxicity in human cells

    Directory of Open Access Journals (Sweden)

    Gillis Bruce S

    2012-07-01

    Full Text Available Abstract Background Lead is a metal with many recognized adverse health side effects, and yet the molecular processes underlying lead toxicity are still poorly understood. Quantifying the injurious effects of lead is also difficult because of the diagnostic limitations that exist when analyzing human blood and urine specimens for lead toxicity. Results We analyzed the deleterious impact of lead on human cells by measuring its effects on cytokine production and gene expression in peripheral blood mononuclear cells. Lead activates the secretion of the chemokine IL-8 and impacts mitogen-dependent activation by increasing the secretion of the proinflammatory cytokines IL-6 and TNF-α and of the chemokines IL-8 and MIP1-α in the presence of phytohemagglutinin. The recorded changes in gene expression affected major cellular functions, including metallothionein expression, and the expression of cellular metabolic enzymes and protein kinase activity. The expression of 31 genes remained elevated after the removal of lead from the testing medium thereby allowing for the measurement of adverse health effects of lead poisoning. These included thirteen metallothionein transcripts, three endothelial receptor B transcripts and a number of transcripts which encode cellular metabolic enzymes. Cellular responses to lead correlated with blood lead levels and were significantly altered in individuals with higher lead content resultantly affecting the nervous system, the negative regulation of transcription and the induction of apoptosis. In addition, we identified changes in gene expression in individuals with elevated zinc protoporphyrin blood levels and found that genes regulating the transmission of nerve impulses were affected in these individuals. The affected pathways were G-protein mediated signaling, gap junction signaling, synaptic long-term potentiation, neuropathic pain signaling as well as CREB signaling in neurons. Cellular responses to lead were

  13. The problem of lead in mexican pottery.

    Science.gov (United States)

    Spielholtz, G I; Kaplan, F S

    1980-11-01

    Much public attention has been focused in the United States on utilitarian Mexican pottery as a source of lead poisoning. Our work demonstrates that, if a firing temperature of at least 1150 degrees is used, lead-glazed earthenware is made safe for the storage and preparation of foods. Examination by d.c. arc emission spectroscopy and X-ray diffraction shows that the lead then remains in crystalline form. An exchange-equilibrium for lead between solutions and earthenware material is postulated.

  14. Lead level in mallard (Anas platyrhynchos

    Directory of Open Access Journals (Sweden)

    Ioan Macinic

    2012-12-01

    Full Text Available The study was carried out on a hunting ground belonging to AJVPS Arad, county Arad. Lead (Pb was determined in Mallard (Anas platyrhynchos tissues (muscles and organs (liver, kidneys to see the contamination level of this tissues and organs and also the impact on humans health because in our days more and more wild game meat take a increasing percentage in humans food ratio. The Mallard is one of the most widespread duck species. Mallard has 50-62 cm length, 800-1400 g weight and lives about 11 years. It prefers rivers and shallow pounds with a lot of reed. It is a migratory species that is flying long distances to find food and unfrozen water, so it is a exposed to lead contamination that is under dust form in atmosphere. But another reason why lead level in Mallard can be higher that in other flying specie (pheasant, woodcock, quail, and pigeons are the lead shot shells that are used for duck hunting. It is known that the ducks can ingest these lead shot shells and so they are often exposed to lead intoxications. This is why in our days more ammunition for waterfowl are steel made or different type of alloys. Lead is known to be one of the most common pollutants with a large range of effects on human health: lead affects nervous system, digestive tract, kidneys, bones, enzymes. Lead has also mutagenic effect, carcinogenic effect, teratogenic effect.

  15. Lead & zinc output of Yuguang Gold & Lead in 2015 may reach 1.20 million tonnes

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>Henan Yuguang Gold & Lead Group Co., Ltd said on December 6 that it would strive to increase lead & zinc output to 1.20 million tonnes in 2015.As the world’s largest lead smelting enterprise,Yuguang Gold & Lead is the largest silver

  16. Evaluation of the use of salivary lead levels as a surrogate of blood lead or plasma lead levels in lead exposed subjects

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Fernando [Universidade de Sao Paulo, Departamento de Analises Clinicas, Toxicologicas e Bromatologicas, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, Ribeirao Preto, SP (Brazil); Correa Rodrigues, Maria H.; Buzalaf, Maria R. [Universidade de Sao Paulo, Departamento de Ciencias Biologicas/Bioquimica, Faculdade de Odontologia de Bauru, Bauru, SP (Brazil); Krug, Francisco J. [Universidade de Sao Paulo, Centro de Energia Nuclear na Agricultura, Piracicaba, SP (Brazil); Gerlach, Raquel F. [Universidade de Sao Paulo, Departamento de Morfologia, Estomatologia e Fisiologia, Faculdade de Odontologia de Ribeirao Preto, Ribeirao Preto, SP (Brazil); Tanus-Santos, Jose E. [Universidade de Sao Paulo, Departamento de Farmacologia, Faculdade de Medicina de Ribeirao Preto, Ribeirao Preto, SP (Brazil)

    2006-10-15

    We conducted a study to evaluate the use of parotid salivary lead (Pb-saliva) levels as a surrogate of the blood lead (Pb-B) or plasma lead levels (Pb-P) to diagnose lead exposure. The relationship between these biomarkers was assessed in a lead exposed population. Pb-saliva and Pb-P were determined by inductively coupled plasma mass spectrometry, while in whole blood lead was determined by graphite furnace atomic absorption spectrometry. We studied 88 adults (31 men and 57 women) from 18 to 60 years old. Pb-saliva levels varied from 0.05 to 4.4 {mu}g/l, with a mean of 0.85 {mu}g/l. Blood lead levels varied from 32.0 to 428.0 {mu}g/l in men (mean 112.3 {mu}g/l) and from 25.0 to 263.0 {mu}g/l (mean 63.5 {mu}g/l) in women. Corresponding Pb-Ps were 0.02-2.50 {mu}g/l (mean 0.77 {mu}g/l) and 0.03-1.6 {mu}g/l (mean 0.42 {mu}g/l) in men and women, respectively. A weak correlation was found between Log Pb-saliva and Log Pb-B (r=0.277, P<0.008), and between Log Pb-saliva and Log Pb-P (r=0.280, P=0.006). The Pb-saliva/Pb-P ratio ranged from 0.20 to 18.0. Age or gender does not affect Pb-saliva levels or Pb-saliva/Pb-P ratio. Taken together, these results suggest that salivary lead may not be used as a biomarker to diagnose lead exposure nor as a surrogate of plasma lead levels at least for low to moderately lead exposed population. (orig.)

  17. Influence of social and environmental factors on dust, lead, hand lead, and blood lead levels in young children

    Energy Technology Data Exchange (ETDEWEB)

    Bornschein, R.L.; Succop, P.; Dietrich, K.N.; Clark, C.S.; Que Hee, S.; Hammond, P.B.

    1985-10-01

    The roles of environmental and behavioral factors in determining blood lead levels were studied in a cohort of young children living in an urban environment. The subjects were observed at 3-month intervals from birth to 24 months of age. Repeated measurements were made of the children's blood lead levels, environmental levels of lead in house dust, and in the dust found on the children's hands. A qualitative rating of the residence and of the socioeconomic status of the family was obtained. Interviews and direct observation of parent and child at home were used to evaluate various aspects of caretaker-child interactions. Data analysis consisted of a comparison of results obtained by (a) simple correlational analysis, (b) multiple regression analysis, and (c) structural equations analysis. The results demonstrated that structural equation modeling offers a useful approach to unraveling the complex interactions present in the data set. In this preliminary analysis, the suspected relationship between the levels of lead in house dust and on hands and the blood lead level was clearly demonstrated. Furthermore, the analyses indicated an important interplay between environmental sources and social factors in the determination of hand lead and blood lead levels in very young children.

  18. Production Planning with Load Dependent Lead Times

    DEFF Research Database (Denmark)

    Pahl, Julia

    2005-01-01

    Lead times impact the performance of the supply chain significantly. Although there is a large literature concerning queuing models for the analysis of the relationship between capacity utilization and lead times, and there is a substantial literature concerning control and order release policies...

  19. The future challenge of lead toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Needleman, H.L. (Univ. of Pittsburgh, PA (USA))

    1990-11-01

    Five decades ago, lead toxicity in childhood was thought in nonlethal cases to be without residual effect. This misconception was corrected in 1943 by Randolph Byers, who began the modern era of lead neurotoxicology by asserting that lead not only killed cells, but interfered with the normal development of central nervous system neurons. The human data from Byers forward is reviewed, with particular attention on methodological issues that have emerged. The papers on human neurotoxicology presented at the NIEHS lead conference held in Research Triangle Park, NC, in 1974 are examined to demonstrate the progress made over the last 15 years. Seven methodological solecisms have clouded judgment over the question of lead toxicity at low dose: worship of the sacrament of p = 0.05; inaccurate causal modeling;drawing conclusions from studies with inadequate power; positing phantom covariates; underestimating the importance of small effects; demanding proof of causality; and evaluating studies in isolation. The principles behind these errors are discussed. Lead exposure is associated with hyperactivity, and hyperactivity is a risk factor for antisocial behavior. The relationship between lead exposure and antisocial behavior is estimated. A plan for the effective removal of one major lead source, housing stock, is presented.

  20. 29 CFR 1915.1025 - Lead.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Lead. 1915.1025 Section 1915.1025 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED... Lead. Note: The requirements applicable to shipyard employment under this section are identical...

  1. Leading chiral logarithms for the nucleon mass

    Energy Technology Data Exchange (ETDEWEB)

    Vladimirov, Alexey A.; Bijnens, Johan [Department of Astronomy and Theoretical Physics, Lund University, Sölvegatan 14A, SE 223 62 Lund (Sweden)

    2016-01-22

    We give a short introduction to the calculation of the leading chiral logarithms, and present the results of the recent evaluation of the LLog series for the nucleon mass within the heavy baryon theory. The presented results are the first example of LLog calculation in the nucleon ChPT. We also discuss some regularities observed in the leading logarithmical series for nucleon mass.

  2. Leading Learning: Science Departments and the Chair

    Science.gov (United States)

    Melville, Wayne; Campbell, Todd; Jones, Doug

    2016-01-01

    In this article, we have considered the role of the chair in leading the learning necessary for a department to become effective in the teaching and learning of science from a reformed perspective. We conceptualize the phrase "leading learning" to mean the chair's constitution of influence, power, and authority to intentionally impact…

  3. Effects of magnetic field applied on leads

    OpenAIRE

    Yamamoto, M.; Ohtsuki, T.; Slevin, K.

    2002-01-01

    The two terminal conductance for two dimensional systems is calculated in the presence of the spin-orbit scattering. The level statistics of the transmission eigenvalue is shown to be sensitive to the asymmetry of the spin population in the lead. The nearest neighbor spacing is GUE instead of GSE when sufficiently large Zeeman splitting is assumed in one of the lead.

  4. Certification and Career Success: A LEADS Project

    Science.gov (United States)

    Russ-Eft, Darlene; Dickison, Phil; Levine, Roger

    2008-01-01

    This study examines the relationship between certification examination test results and Emergency Medical Technician (EMT) career success. The sample was drawn from the Longitudinal Emergency Medical Technician Attributes and Demographics Study (LEADS). LEADS participants were matched with National Registry of Emergency Medical Technician (NREMT)…

  5. A lattice for a lead storage battery

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, S.; Fukunaga, K.; Kumano, Y.

    1983-07-13

    Lattices for a lead storage cell are made of a lead alloy which contains (in percent by mass): 0.05 to 0.3 strontium; 0.02 to 0.1 aluminum; 0.05 to 3.0 tin and 0.01 to 3.0 cadmium. The storage cell has low autodischarge and a long service life.

  6. Tracing changes in atmospheric sources of lead contamination using lead isotopic compositions in Australian red wine.

    Science.gov (United States)

    Kristensen, Louise Jane; Taylor, Mark Patrick; Evans, Andrew James

    2016-07-01

    Air quality data detailing changes to atmospheric composition from Australia's leaded petrol consumption is spatially and temporally limited. In order to address this data gap, wine was investigated as a potential proxy for atmospheric lead conditions. Wine spanning sixty years was collected from two wine regions proximal to the South Australian capital city, Adelaide, and analysed for lead concentration and lead and strontium isotopic composition for source apportionment. Maximum wine lead concentrations (328 μg/L) occur prior to the lead-in-air monitoring in South Australia in the later 1970s. Wine lead concentrations mirror available lead-in-air measurements and show a declining trend reflecting parallel reductions in leaded petrol emissions. Lead from petrol dominated the lead in wine ((206)Pb/(207)Pb: 1.086; (208)Pb/(207)Pb: 2.360) until the introduction of unleaded petrol, which resulted in a shift in the wine lead isotopic composition closer to vineyard soil ((206)Pb/(207)Pb: 1.137; (208)Pb/(207)Pb: 2.421). Current mining activities or vinification processes appear to have no impact with recent wine samples containing less than 4 μg/L of lead. This study demonstrates wine can be used to chronicle changes in environmental lead emissions and is an effective proxy for atmospherically sourced depositions of lead in the absence of air quality data.

  7. Health care of people at work. Workers exposed to lead. I. Inorganic lead

    Energy Technology Data Exchange (ETDEWEB)

    Waldron, H.A.

    1978-01-01

    The risks associated with exposure to inorganic lead and the means by which these risks can be minimized are outlined. Lead is used to make a variety of metal products, the grids and oxides in storage batteries, pigments, chemicals, and also for lead plating. In the United States about 70% of the total lead consumption is related to transportation. Uptake of inorganic lead is by ingestion and inhalation. About 90% of the total body burden of lead is contained within the skeletal tissues. Lead is excreted in the kidney, in sweat, and in milk. Toxic effects are directed against the blood, the nervous system, and the kidney. Symptoms of lead poisoning are abdominal pain, constipation, vomiting, asthenia, paresthesia, psychological symptoms, and diarrhea. Physical and biological monitoring can serve to protect workers. Diagnosis of lead poisoning is not easy. Treatment involves removal from exposure and/or treatment with a chelating agent.

  8. The differences of electrochemical performance between the purchased lead carbonate and the prepared lead carbonate

    Institute of Scientific and Technical Information of China (English)

    包有富

    2005-01-01

    The differences of electrochemistry performance between the purchased lead carbonate and the prepared lead carbonate were studied by the methods of cycle voltammogram, electrochemical impedance spectroscope (EIS), constant current discharge, thermal gravimetric analysis, and scan electron microscope (SEM) etc. in the paper. It was showed that the reacting activity of the prepared lead carbonate was higher than that of the purchased lead carbonate. And several points of view were concluded as follows. (1) The prepared lead carbonate contains chemical structure water, but the purchased lead carbonate doesn't contain chemical structure water. (2) The main chemical substance in the purchased lead carbonate powder is PbCO3, while the one in the prepared lead carbonate is smaller than that of the pur-chased lead carbonate.

  9. Vector boson and Charmonium production in proton-lead and lead-lead collisions with ATLAS at the LHC

    CERN Document Server

    Citron, Zvi Hirsh; The ATLAS collaboration

    2016-01-01

    Electroweak bosons do not interact strongly with the dense and hot medium formed in nuclear collisions, and thus should be sensitive to the nuclear modification of parton distribution functions (nPDFs). The in-medium modification of heavy charmonium states plays an important role in studying the hot and dense medium. The ATLAS detector, optimized to search for new physics in proton-proton collisions, is well equipped to measure Z and W bosons as well as quarkonium in the high occupancy environment produced in heavy ion collisions. Results from the ATLAS experiment on W and Z boson yields as a function of centrality, transverse momentum and rapidity, in lead-lead and proton-lead collisions are presented. Quarkonium results from proton-lead collisions are also presented.

  10. Neurohumoral blood pressure regulation in lead exposure

    Energy Technology Data Exchange (ETDEWEB)

    Boscolo, P.; Carmignani, M.

    1988-06-01

    Previous human studies demonstrated that lead exposure may modify the metabolism of catecholamines and of hormones controlled by the hypothalamo-pituitary axis and may affect the kallikrein-kinin system. This paper reports unpublished data on the plasma renin activity of lead-exposed workers; these results are in agreement with those of previous human and experimental studies suggesting that the synthesis or release of renin is increased after short and moderate exposure to inorganic lead and reduced whenever the exposure is prolonged. Previous experimental investigations demonstrated that lead may act on the cardiovascular system, with effects on the renin-angiotensin system, on the reactivity to stimulation of peripheral catecholaminergic receptors, on sympathetic and vagal tone, and on reactivity to the stimulation of baroreceptors. This paper reports the results of a study on male Sprague-Dawley rats that received 0, 15, 30, and 60 ..mu..g/mL of lead in drinking water for 18 months. Blood pressure was increased in the rats receiving 30 and 60 ppm of lead; cardiac inotropism was augmented only in those receiving the higher dose of the metal, and heart rate was not modified. Cardiovascular responses to agonists indicated that lead exposure affects the renin-angiotensin system and induces sympathetic hyperactivity be acting on central and peripheral sympathetic junctions increasing the responsiveness to stimulation of ..cap alpha../sub 2/-adrenoreceptors and by increasing the reactivity to stimulation of cardiac and vascular ..beta..-adrenergic and dopaminergic receptors.

  11. Lead removal in rats using calcium alginate.

    Science.gov (United States)

    Savchenko, Olga V; Sgrebneva, Marina N; Kiselev, Vladimir I; Khotimchenko, Yuri S

    2015-01-01

    Lead (Pb) exposure, even at low levels, causes a variety of health problems. The aims of this study were to investigate the tissue distribution of lead in the bodies of rats, to evaluate lead removal from the internal organs and bones using calcium alginate in doses of 500, 200 and 100 mg/kg per day for 28 days and to assess the impact of calcium alginate on the level of essential elements. Lead (Pb), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu) and zinc (Zn) levels in the blood, hearts, kidneys, livers and femurs of the experimental animals were measured using mass spectrometry with inductively coupled plasma. The results revealed that lead acetate exposure increased the levels of Pb in the blood and organs of the animals and significantly reduced contents of Ca, Mn, Fe, Cu and Zn. Treatment with calcium alginate in dose 500 mg/kg contributed to significant decreases in the amount of lead in the kidney, heart and bones of animals and a slight increase in the content of essential elements in the liver, kidneys and heart, although these changes were not significant. Decreasing of lead was not significant in the internal organs, bones and blood of animals treated with calcium alginate 200 and 100 mg/kg. Consequently, calcium alginate dose of 500 mg/kg more efficiently removes lead accumulated in the body. Calcium alginate does not have negative effect on level of essential elements quite the contrary; reducing the levels of lead, calcium alginate helps normalize imbalances of Ca, Mn, Fe, Cu and Zn. The results of this study suggest that calcium alginate may potentially be useful for the treatment and prevention of heavy metal intoxications.

  12. Pb Neurotoxicity: Neuropsychological Effects of Lead Toxicity

    Directory of Open Access Journals (Sweden)

    Lisa H. Mason

    2014-01-01

    Full Text Available Neurotoxicity is a term used to describe neurophysiological changes caused by exposure to toxic agents. Such exposure can result in neurocognitive symptoms and/or psychiatric disturbances. Common toxic agents include heavy metals, drugs, organophosphates, bacterial, and animal neurotoxins. Among heavy metal exposures, lead exposure is one of the most common exposures that can lead to significant neuropsychological and functional decline in humans. In this review, neurotoxic lead exposure's pathophysiology, etiology, and epidemiology are explored. In addition, commonly associated neuropsychological difficulties in intelligence, memory, executive functioning, attention, processing speed, language, visuospatial skills, motor skills, and affect/mood are explored.

  13. Lead hepatotoxicity: Selected aspects of pathobiochemistry

    Directory of Open Access Journals (Sweden)

    Mateusz Labudda

    2013-08-01

    Full Text Available Lead (Pb that belongs to heavy metals is one of the major pollution components of the environment. Occupational and environmental exposure to lead can cause its absorption by the body and consequently exert toxic effects in the liver. In this paper biochemical determinants of hepatotoxicity caused by lead are presented. Generation of reactive oxygen species, disturbances in the cellular antioxidant system, lipid peroxidation, inhibition of enzymatic proteins and intercellular signaling are also discussed. Med Pr 2013;64(4:565–568

  14. Peltier Current Leads with conical configuration

    Science.gov (United States)

    Hakimi, I.; Nikulshin, Y.; Wolfus, S.; Yeshurun, Y.

    2016-04-01

    Current leads in cryogenic systems are a major heat source which eventually affects the entire system. It has been shown in recent years that Peltier elements are useful in reducing incoming heat into the cold system. In this article we present a new tapered cone-like configuration of the Peltier Current Leads which increases the power saving. This configuration is compared to the standard cylindrical configuration utilizing advanced ANSYS simulations. The simulations show an additional power saving of 4% when using the tapered lead configuration.

  15. Cavitation on hydrofoils with sinusoidal leading edge

    Science.gov (United States)

    Johari, H.

    2015-12-01

    Cavitation characteristics of hydrofoils with sinusoidal leading edge were examined experimentally at a Reynolds number of 7.2 × 105. The hydrofoils had an underlying NACA 634-021 profile and an aspect ratio of 4.3. The sinusoidal leading edge geometries included three amplitudes of 2.5%, 5%, and 12% and two wavelengths of 25% and 50% of the mean chord length. Results revealed that cavitation on the leading edge-modified hydrofoils existed in pockets behind the troughs whereas the baseline hydrofoil produced cavitation along its entire span. Moreover, cavitation on the modified hydrofoils appeared at consistently lower angles of attack than on the baseline hydrofoil.

  16. Psychiatric epidemiologic study of occupational lead exposure

    Energy Technology Data Exchange (ETDEWEB)

    Parkinson, D.K.; Ryan, C.; Bromet, E.J.; Connell, M.M.

    1986-02-01

    The association of occupational lead exposure with neuropsychiatric functioning was evaluated using data collected in 1982 in eastern Pennsylvania from 288 lead-exposed workers and 181 nonexposed subjects. Both current and cumulative exposure indices were used. After controlling for age, education, and income, few meaningful differences between exposed and control workers were found on either neuropsychologic or psychosocial variables. Dose-response analyses indicated that among lead-exposed workers, cumulative and current exposure were unrelated to neuropsychologic performance. The only meaningful associations occurred between exposure and level of conflict in interpersonal relationships. The results thus give evidence against hypotheses suggesting adverse neuropsychologic effects.

  17. 29 CFR 1926.62 - Lead.

    Science.gov (United States)

    2010-07-01

    ... used to determine methods selected for controlling exposure to lead; (C) A report of the technology... contamination of the employee and the employee's garments such as, but not limited to: (i) Coveralls or...

  18. Semiautomatic device tests components with biaxial leads

    Science.gov (United States)

    Marshall, T. C.

    1966-01-01

    Semiautomatic device with a four-terminal network tests quantities of components having biaxial leads. The four-terminal network permits the testing of components in different environments. This device is easily modified for completely automatic operation.

  19. Treating Lead Toxicity: Possibilities beyond Synthetic Chelation

    Directory of Open Access Journals (Sweden)

    Shambhavi Tannir

    2013-01-01

    Full Text Available Lead, a ubiquitous metal, is one of the most abundant elements present on earth. Its easy availability and cost effectiveness made it an extremely popular component in the industrial revolution. However, its hazardous health effects were not considered at the time. Over the last few decades, with the adverse effects of lead coming to the forefront, nations across the world have started to recognize and treat lead toxicity. The most reliable and used method until now has been chelation therapy. Recent research has suggested the use of natural products and sources to treat lead poisoning with minimal or no side effects. This review has tried to summarize a few of the natural products/sources being investigated by various groups.

  20. FDA Suggests Limits on Lead in Cosmetics

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_162726.html FDA Suggests Limits on Lead in Cosmetics Agency notes ... the authority to enforce such a limit, the FDA recommended in a draft guidance issued Thursday that ...

  1. Superconducting Current Leads for Cryogenic Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Space flight cryocoolers will be able to handle limited heat loads at their expected operating temperatures and the current leads may be the dominant contributor to...

  2. Ayurvedic herbal medicine and lead poisoning

    Directory of Open Access Journals (Sweden)

    Gunturu Krishna S

    2011-12-01

    Full Text Available Abstract Although the majority of published cases of lead poisoning come from occupational exposures, some traditional remedies may also contain toxic amounts of lead. Ayurveda is a system of traditional medicine that is native to India and is used in many parts of world as an alternative to standard treatment regimens. Here, we report the case of a 58-year-old woman who presented with abdominal pain, anemia, liver function abnormalities, and an elevated blood lead level. The patient was found to have been taking the Ayurvedic medicine Jambrulin prior to presentation. Chemical analysis of the medication showed high levels of lead. Following treatment with an oral chelating agent, the patient's symptoms resolved and laboratory abnormalities normalized. This case highlights the need for increased awareness that some Ayurvedic medicines may contain potentially harmful levels of heavy metals and people who use them are at risk of developing associated toxicities.

  3. Lead levels on traffic-less islands.

    Science.gov (United States)

    Elwood, P C; Blaney, R; Robb, R C; Essex-Cater, A J; Davies, B E; Toothill, C

    1985-09-01

    Surveys were conducted on three traffic-less islands: Tory and Aran, off the coast of Ireland, and Sark, one of the Channel Islands off the coast of France. Identical methods were used in surveys in three other areas, all of which have heavy gasoline driven traffic. These were Jersey, another of the Channel Islands, Ebbw Vale--a mixed industrial area, and Cardiff--the capital city of Wales. Environmental lead levels were very low in two of the traffic-less islands, but on the third, house dust lead levels were comparable with levels found throughout Wales. Blood lead levels on one of the islands were similar to those which have been reported for unaccultured remote tribes, but on the other two traffic-less islands blood lead levels were comparable with those of areas on the mainland of Wales.

  4. Education review lead backs compulsory preceptorship.

    Science.gov (United States)

    Mckew, Matthew

    2017-03-29

    All new nurses should complete a mandatory preceptorship year to help them meet new Nursing and Midwifery Council (NMC) requirements, an academic leading the regulator's 'radical' overhaul of education standards has said.

  5. Relationship between soil lead and airborne lead concentrations at Springfield, Missouri, USA

    Energy Technology Data Exchange (ETDEWEB)

    Sheets, R.W.; Kyger, J.R.; Biagioni, R.N.; Probst, S. [Department of Chemistry, Southwest Missouri State University, 65804 Springfield, MO (United States); Boyer, R.; Barke, K. [Greene County Health Department, 65802 Springfield, MO (United States)

    2001-04-23

    This study tests whether lead deposited to soil from automobiles during past years in a medium-sized US city (population 150000) may present a current health risk. It examines the relationship between current soil lead concentrations at nine locations within the city of Springfield, Missouri, and airborne lead levels measured at the same locations during years (1975-1981) when lead emissions from automobiles were much greater than at present. A strong, significant correlation is found between soil and airborne lead levels at eight of the sites (r=0.91, P<0.005 for soil lead vs. 1979 airborne lead), in low-traffic areas as well as in areas adjacent to heavy traffic flow. Residual lead concentrations in these soils are relatively low, even for the high-traffic sites, as expected for a medium sized city.

  6. Investigations on organolead compounds V. Lead---lead bond cleavage reactions of hexaphenyldilead

    NARCIS (Netherlands)

    Willemsens, L.C.; Kerk, G.J.M. van der

    1968-01-01

    It has been shown that a number of nucleophilic and weakly electrophilic reagents (organolithium and organomagnesium compounds, metallic lithium, potassium permanganate, sodium ethoxide, diaryl disulphides, sulphur, ozone, hypochlorous acid and iodine/iodide) selectively cleave the lead---lead bond

  7. Corrosion by liquid lead and lead-bismuth: experimental results review and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jinsuo [Los Alamos National Laboratory

    2008-01-01

    Liquid metal technologies for liquid lead and lead-bismuth alloy are under wide investigation and development for advanced nuclear energy systems and waste transmutation systems. Material corrosion is one of the main issues studied a lot recently in the development of the liquid metal technology. This study reviews corrosion by liquid lead and lead bismuth, including the corrosion mechanisms, corrosion inhibitor and the formation of the protective oxide layer. The available experimental data are analyzed by using a corrosion model in which the oxidation and scale removal are coupled. Based on the model, long-term behaviors of steels in liquid lead and lead-bismuth are predictable. This report provides information for the selection of structural materials for typical nuclear reactor coolant systems when selecting liquid lead or lead bismuth as heat transfer media.

  8. Production LHC HTS power lead test results

    CERN Document Server

    Tartaglia, M; Fehér, S; Huang, Y; Orris, D F; Pischalnikov, Y; Rabehl, Roger Jon; Sylvester, C D; Zbasnik, J

    2005-01-01

    The Fermilab Magnet test facility has built and operated a test stand to characterize the performance of HTS power leads. We report here the results of production tests of 20 pairs of 7.5 kA HTS power leads manufactured by industry for installation in feed boxes for the LHC Interaction Region quadrupole strings. Included are discussions of the thermal, electrical, and quench characteristics under "standard" and "extreme" operating conditions, and the stability of performance across thermal cycles.

  9. Who's in the Lead?

    Science.gov (United States)

    Flores, Alfinio

    2014-01-01

    Tossing a fair coin 1000 times can have an unexpected result. In the activities presented here, players keep track of the accumulated total for heads and tails after each toss, noting which player is in the lead or whether the players are tied. The winner is the player who was in the lead for the higher number of turns over the course of the game.…

  10. Lead, mercury, and cadmium in breast milk

    OpenAIRE

    Kadriye Yurdakök

    2015-01-01

    Toxic heavy metals are the major source of environmental pollution in this new millennium. Lead, mercury, and cadmium are the most common toxic heavy metals in the environment. There is no known function of these toxic heavy metals in the human body. In females, toxic heavy metals can be accumulated in maternal body before pregnancy and may be transferred to fetus through placenta and later, via breast milk. Lead previously accumulated in maternal bones can be mobilized along with calcium in ...

  11. Information from leading neutrons at HERA

    CERN Document Server

    Khoze, V A; Ryskin, M G

    2006-01-01

    In principle, leading neutrons produced in photoproduction and deep-inelastic scattering at HERA have the potential to determine the pion structure function, the neutron absorptive cross section and the form of the pion flux. To explore this potential we compare theoretical predictions for the x_L and p_t spectra of leading neutrons, and the Q^2 dependence of the cross section, with the existing ZEUS data.

  12. Lead Toxicity Risks in Gunshot Victims.

    Directory of Open Access Journals (Sweden)

    Gabriel Costa Serrão de Araújo

    Full Text Available Gunshot wounds require surgeons to decide whether to remove or leave bullet fragments in the body. Surgeons also decide how to follow up with patients who have lead fragments retained in their body. Current literature recommends to remove only intra-articular fragments without the need for a follow-up for patients with the metal retained. Therefore, this study investigates chronic lead toxicity for gunshot wounds.The study was performed in the metropolitan area of Rio de Janeiro/Brazil, between 2013 and 2015. It was a case-control study that included 45 victims of gunshot lesions with metallic fragments retained for more than 6 months. The 45 controls were matched for gender, age, and race. We compared the lead blood levels and frequency of symptoms.The control group had average blood lead levels of 2.17 μg/dL (95% Confidence Interval [CI]; 1.71-2.63 and median 2.1 μg/dL. The case group had average values of 9.01 μg/dL (CI; 6.07-11.96 and median values of 6.5 μg/dL with p-values < = 0.001. The case group reported the following more frequently: irritancy, bad mood, headache, memory losses, daylight drowsiness, myalgia, weakness, abdominal pain, joint pain, trembling, tingling limbs. There was statistical significance for the differences of symptoms frequencies and for odds ratio between groups.Although the mean lead levels found were lower than the current laboratory references, low levels have been associated with both rising morbidity and mortality. The WHO stated: "There is no known level of lead exposure that is considered safe". In conclusion, this work showed that bullets retained in the body are not innocuous. There are impacts in the blood lead levels and symptoms related to it, even with few fragments, extra-articular located or existing with low blood lead levels.

  13. Connecting to Thermocouples with Fewer Lead Wires

    Science.gov (United States)

    Goldsby, Jon C.

    2003-01-01

    A simple technique has been devised to reduce the number of lead wires needed to connect an array of thermocouples to the instruments (e.g., voltmeters) used to read their output voltages. Because thermocouple wires are usually made of expensive metal alloys, reducing the number of lead wires can effect a considerable reduction in the cost of such an array. Reducing the number of wires also reduces the number of terminals and the amount of space needed to accommodate the wires.

  14. Understanding innovation drive of leading Serbian companies

    Directory of Open Access Journals (Sweden)

    Ljubomir Pupovac

    2010-10-01

    Full Text Available Innovation oriented business will lead to faster growth, increased market share and better corporate positioning and thus is viewed as the prime strategy. The paper discusses the effectiveness of innovation in chosen leading companies in Serbian market in confectionery, dairy and meat processing industry. Companies, having more than 50 years of continuous production are the absolute market leaders and pioneers in their industries. Understanding their drive, sources of innovation and effectiveness is the concern of this paper.

  15. Renovate Right: Prevent Lead Poisoning in Children

    Centers for Disease Control (CDC) Podcasts

    2008-10-02

    In this podcast, Dr. Maria Doa, Director of the Environmental Protection Agency's (EPA) National Program Chemicals Division, discusses EPA's new rule for renovations, repairs, and painting activities. The new rule includes information on lead-safe work practices when conducting renovations, repairs, and painting in pre-1978 homes and schools to prevent the spread of lead dust.  Created: 10/2/2008 by National Center for Environmental Health (NCEH).   Date Released: 10/2/2008.

  16. Blood lead levels and chronic blood loss

    Energy Technology Data Exchange (ETDEWEB)

    Manci, E.A.; Cabaniss, M.L.; Boerth, R.C.; Blackburn, W.R.

    1986-03-01

    Over 90% of lead in blood is bound to the erythrocytes. This high affinity of lead for red cells may mean that chronic blood loss is a significant means for excretion of lead. This study sought correlations between blood lead levels and clinical conditions involving chronic blood loss. During May, June and July, 146 patients with normal hematocrits and red cell indices were identified from the hospital and clinic populations. For each patient, age, race, sex and medical history were noted, and a whole blood sample was analyzed by flameless atomic absorption spectrophotometry. Age-and race-matched pairs showed a significant correlation of chronic blood loss with lead levels. Patients with the longest history of blood loss (menstruating women) had the lowest level (mean 6.13 ..mu..g/dl, range 3.6-10.3 ..mu..g/dl). Post-menopausal women had levels (7.29 ..mu..g/dl, 1.2-14 ..mu..g/dl) comparable to men with peptic ulcer disease, or colon carcinoma (7.31 ..mu..g/dl, 5.3-8.6 ..mu..g/dl). The highest levels were among men who had no history of bleeding problems (12.39 ..mu..g/dl, 2.08-39.35 ..mu..g/dl). Chronic blood loss may be a major factor responsible for sexual differences in blood lead levels. Since tissue deposition of environmental pollutants is implicated in diseases, menstruation may represent a survival advantage for women.

  17. Environmentally sound technologies for recycling secondary lead

    Science.gov (United States)

    Andrews, D.; Raychaudhuri, A.; Frias, C.

    Advances in hydrometallurgy are providing increasingly simple means for controlling the entire lead chain from concentrate to recycled lead. Used in parallel with pyrometallurgy, these processes allow furnace temperatures to be reduced to the minimum, which is essential for casting or alloying. Fumes and atmospheric pollution are minimized, furnace slags are digested, and most residues (other than purification cements) are non-toxic and convertible into marketable products. These new processes provide the cleanest and healthiest practicable means for recycling lead from batteries. By substituting melting for smelting, the heat requirement and cycle time per charge are reduced by more than half. A new hydrometallurgical plant could be installed alongside an existing pyrometallurgical plant without interference, doubling its potential capacity when operational (and more, if electrowinning is used). Over 99.5% of the lead originally present is recovered in tests of a combined PLACID-pyro plant. The average purity of electrowon PLACID lead is 99.995%. Results from the PLINT process should be similar. The purity of the lead chain can thereby be sustained through recycling. Perfect solid/paste separation is not mandatory, and PLINT-type plant units can be of any size. Such processes constitute a good basis for development of clean processes, which are suitable for use in Asian societies.

  18. Lead isotopes as a supplementary tool in the routine evaluation of household lead hazards.

    OpenAIRE

    Gwiazda, R H; Smith, D. R.

    2000-01-01

    The advent of magnetic sector inductively coupled plasma-mass spectrometry (ICP-MS) allows rapid, accurate, and precise measurement of lead isotopes in environmental and biological samples at a lower cost than traditional methods. This may increase the feasibility of including lead isotope measurements as a routine tool to identify household sources of lead exposure to children. Here, we present three household case studies to illustrate how lead hazard evaluations by an environmental special...

  19. Association of defects in lead chloride and lead bromide: Ionic conductivity and dielectric loss measurements

    NARCIS (Netherlands)

    Brom, W.E. van den; Schoonman, J.; Wit, J.H.W. de

    1972-01-01

    The ionic conductivity data of pure and doped lead bromide without associated defects are used in order to explain the anomalous conductivity behaviour of copper (I) bromide and lead oxide-doped lead-bromide crystals. In these crystals precipitated dopant and associated defects are present. The asso

  20. 76 FR 4641 - Children's Products Containing Lead; Technological Feasibility of 100 ppm for Lead Content...

    Science.gov (United States)

    2011-01-26

    ... of meeting the 100 ppm lead content limit for children's products and associated public health... children's products. Section 101(d) of the CPSIA (15 U.S.C. 1278a(d)) provides that a lead limit shall be... children's products in the market now that meet the 100 ppm lead content limits, and that it is not...

  1. 78 FR 41298 - Children's Products Containing Lead; Procedures and Requirements for Exclusions From Lead Limits...

    Science.gov (United States)

    2013-07-10

    ... COMMISSION 16 CFR Part 1500 Children's Products Containing Lead; Procedures and Requirements for Exclusions From Lead Limits Under Section 101(b) of the Consumer Product Safety Improvement Act AGENCY: Consumer... for exclusions from lead limits under section 101(b) of the Consumer Product Safety Improvement Act...

  2. 76 FR 12944 - Children's Products Containing Lead; Technological Feasibility of 100 ppm for Lead Content...

    Science.gov (United States)

    2011-03-09

    ... of January 26, 2011 (76 FR 4641), we published a notice (``hearing notice'') announcing that the... COMMISSION Children's Products Containing Lead; Technological Feasibility of 100 ppm for Lead Content; Notice... feasibility of meeting the 100 ppm lead content limit for children's products and associated public...

  3. 75 FR 43942 - Children's Products Containing Lead; Technological Feasibility of 100 ppm for Lead Content...

    Science.gov (United States)

    2010-07-27

    ... COMMISSION Children's Products Containing Lead; Technological Feasibility of 100 ppm for Lead Content... content limit for children's products. DATES: Written comments and submissions in response to this notice... for children 12 years old and younger, the total lead content limit by weight in any part of...

  4. Site-specific lead exposure from lead pellet ingestion in sentinel mallards

    Science.gov (United States)

    Rocke, T.E.; Brand, C.J.; Mensik, John G.

    1997-01-01

    We monitored lead poisoning from the ingestion of spent lead pellets in sentinel mallards (Anas platyhrynchos) at the Sacramento National Wildlife Refuge (SNWR), Willows, California for 4 years (1986-89) after the conversion to steel shot for waterfowl hunting on refuges in 1986. Sentinel mallards were held in 1.6-ha enclosures in 1 hunted (P8) and 2 non-hunted (T19 and TF) wetlands. We compared site-specific rates of lead exposure, as determined by periodic measurement of blood lead concentrations, and lead poisoning mortality between wetlands with different lead pellet densities, between seasons, and between male and female sentinels. In 1986, the estimated 2-week rate of lead exposure was significantly higher (P 2,000,000 pellets/ha), than in those with lower densities of lead pellets, T19 (18.1%; 173,200 pellets/ha) and TF (0.9%; 15,750 pellets/ha). The probability of mortality from lead poisoning was also significantly higher (P < 0.01) in sentinel mallards enclosed in P8 (0.25) than T19 (0) and TF (0) in 1986 and remained significantly higher (P < 0.001) during the 4-year study. Both lead exposure and the probability of lead poisoning mortality in P8 were significantly higher (P < 0.001) in the fall of 1986 (43.8%; 0.25), before hunting season, than in the spring of 1987 (21.6%; 0.04), after hunting season. We found no significant differences in the rates of lead exposure or lead poisoning mortality between male and female sentinel mallards. The results of this study demonstrate that in some locations, lead exposure and lead poisoning in waterfowl will continue to occur despite the conversion to steel shot for waterfowl hunting.

  5. Children's Blood Lead Seasonality in Flint, Michigan (USA), and Soil-Sourced Lead Hazard Risks.

    Science.gov (United States)

    Laidlaw, Mark A S; Filippelli, Gabriel M; Sadler, Richard C; Gonzales, Christopher R; Ball, Andrew S; Mielke, Howard W

    2016-03-25

    In Flint; MI; USA; a public health crisis resulted from the switching of the water supply from Lake Huron to a more corrosive source from the Flint River in April 2014; which caused lead to leach from water lines. Between 2010 and 2015; Flint area children's average blood lead patterns display consistent peaks in the third quarter of the year. The third quarter blood lead peaks displayed a declining trend between 2010 and 2013; then rose abruptly between the third quarters of 2013 from 3.6% blood lead levels ≥5 µg/dL to a peak of about 7% in the third quarter of 2014; an increase of approximately 50%. The percentage of blood lead level ≥5 µg/dL in the first quarter of 2015 then dropped to 2.3%; which was the same percentage as the first quarter of 2014 (prior to the Flint River water source change). The Flint quarterly blood lead level peak then rose to about 6% blood lead levels ≥ 5 µg/dL in the third quarter of 2015; and then declined to about 2.5% in the fourth quarter of 2015. Soil lead data collected by Edible Flint food collaborative reveal generally higher soil lead values in the metropolitan center for Flint; with lower values in the outskirts of the city. The questions that are not being asked is why did children's blood lead levels display a seasonal blood lead pattern before the introduction of the new water supply in Flint; and what are the implications of these seasonal blood lead patterns? Based upon previous findings in Detroit and other North American cities we infer that resuspension to the air of lead in the form of dust from lead contaminated soils in Flint appears to be a persistent contribution to lead exposure of Flint children even before the change in the water supply from Lake Huron to the Flint River.

  6. Studies on the Analysis of Lead and Silica in Lead Processing Samples

    Directory of Open Access Journals (Sweden)

    R. Ravichandra Babu

    2014-01-01

    Full Text Available In Practice two samples have to be proceeded separately to determine both lead and silica in lead process samples like concentrates, coarse sinter etc. In the present recommended procedure, the lead and silica are precipitated together by using acid fuming, but, instead of using ammonium acetate treatment to separate lead and silica, a mixture of hydrochloric acid-sodium chloride is used to achieve the same purpose. This helps in determine all the components of lead process samples from the same solution without loss of accuracy in any of the components. This method saves considerable time and especially useful for routine analysis in process control lab.

  7. Influence of Slippery Pacemaker Leads on Lead-Induced Venous Occlusion

    Science.gov (United States)

    Yang, Weiguang; Bhatia, Sagar; Obenauf, Dayna; Resse, Max; Esmaily-Moghadam, Mahdi; Feinstein, Jeffrey; Pak, On Shun

    2016-11-01

    The use of medical devices such as pacemakers and implantable cardiac defibrillators have become commonplace to treat arrhythmias. Pacing leads with electrodes are used to send electrical pulses to the heart to treat either abnormally slow heart rates, or abnormal rhythms. Lead induced vessel occlusion, which is commonly seen after placement of pacemaker or ICD leads, may result in lead malfunction and/or SVC syndrome, and makes lead extraction difficult. The association between the anatomic locations at risk for thrombosis and regions of venous stasis have been reported previously. The computational studies reveal obvious flow stasis in the proximity of the leads, due to the no-slip boundary condition imposed on the lead surface. With the advent of recent technologies capable of creating slippery surfaces that can repel complex fluids including blood, we explore computationally how local flow structures may be altered in the regions around the leads when the no-slip boundary condition on the lead surface is relaxed using various slip lengths. The findings evaluate the possibility of mitigating risks of lead-induced thrombosis and occlusion by implementing novel surface conditions (i.e. theoretical coatings) on the leads.

  8. Modeling of Blood Lead Levels in Astronauts Exposed to Lead from Microgravity-Accelerated Bone Loss

    Science.gov (United States)

    Garcia, H.; James, J.; Tsuji, J.

    2014-01-01

    Human exposure to lead has been associated with toxicity to multiple organ systems. Studies of various population groups with relatively low blood lead concentrations (adults. Cognitive effects are considered by regulatory agencies to be the most sensitive endpoint at low doses. Although 95% of the body burden of lead is stored in the bones, the adverse effects of lead correlate with the concentration of lead in the blood better than with that in the bones. NASA has found that prolonged exposure to microgravity during spaceflight results in a significant loss of bone minerals, the extent of which varies from individual to individual and from bone to bone, but generally averages about 0.5% per month. During such bone loss, lead that had been stored in bones would be released along with calcium. The effects on the concentration of lead in the blood (PbB) of various concentrations of lead in drinking water (PbW) and of lead released from bones due to accelerated osteoporosis in microgravity, as well as changes in exposure to environmental lead before, during, and after spaceflight were evaluated using a physiologically based pharmacokinetic (PBPK) model that incorporated exposure to environmental lead both on earth and in flight and included temporarily increased rates of osteoporosis during spaceflight.

  9. Lead dietary exposure in the European population

    Directory of Open Access Journals (Sweden)

    European Food Safety Authority

    2012-07-01

    Full Text Available

    Lead is a natural environmental contaminant, but its use in the past in water pipes, paint and petrol increased its general presence. Food is the major source of human exposure to lead. Lead accumulates in the body and most seriously affects the developing central nervous system in young children. There is no recommended tolerable intake level as there is no evidence of thresholds for a number of critical health effects. Legislative measures have been gradually introduced to reduce exposure by removing lead from paint, food cans, water pipes and petrol. The current study examined 144,206 analytical results for lead in food collected during a nine-year period. More than half of the foods tested had levels of lead at less than detection or quantification limits. The mean lead levels varied between 0.3 µg/kg for infant follow-on formulae to 4,300 µg/kg for dietetic products with an overall median across all categories of 21.4 µg/kg. Food lead levels decreased by about 23 % between 2003 and 2010, although this should be interpreted cautiously. Mean lifetime dietary exposure was estimated at 0.68 µg/kg b.w. per day in the European population based on middle bound mean lead occurrence. Exposure was highest for toddlers and other children with 1.32 and 1.03 µg/kg b.w. per day, respectively, while the two infant surveys ranged between 0.83 and 0.91 µg/kg b.w. per day. Adult exposure was estimated at 0.50 µg/kg b.w. per day. The elderly and very elderly population groups had similar profiles to the adult age group, while adolescents had slightly higher estimated dietary exposure. Important food category contributors include bread and rolls (8.5 %, tea (6.2 %, tap water (6.1 %, potatoes and potato products (4.9 %, fermented milk products (4.2% and beer and beer-like beverages (4.1 %, although this will vary between age groups and surveys.

  10. Lead contamination and transfer in urban environmental compartments analyzed by lead levels and isotopic compositions.

    Science.gov (United States)

    Hu, Xin; Sun, Yuanyuan; Ding, Zhuhong; Zhang, Yun; Wu, Jichun; Lian, Hongzhen; Wang, Tijian

    2014-04-01

    Lead levels and isotopic compositions in atmospheric particles (TSP and PM2.5), street dust and surface soil collected from Nanjing, a mega city in China, were analyzed to investigate the contamination and the transfer of lead in urban environmental compartments. The lead contents in TSP and PM2.5 are significantly higher than them in the surface soil and street dust (p atmospheric particles. The plots of (206)Pb/(207)Pb vs.(208)Pb/(206)Pb and (206)Pb/(207)Pb vs. 1/Pb imply that the street dust and atmospheric particles (TSP and PM2.5) have very similar lead sources. Coal emissions and smelting activities may be the important lead sources for street dust and atmospheric particles (TSP and PM2.5), while the deposition of airborne lead is an important lead source for urban surface soil.

  11. Lead sorption-desorption from organic residues.

    Science.gov (United States)

    Duarte Zaragoza, Victor M; Carrillo, Rogelio; Gutierrez Castorena, Carmen M

    2011-01-01

    Sorption and desorption are mechanisms involved in the reduction of metal mobility and bioavailability in organic materials. Metal release from substrates is controlled by desorption. The capacity of coffee husk and pulp residues, vermicompost and cow manure to adsorb Pb2+ was evaluated. The mechanisms involved in the sorption process were also studied. Organic materials retained high concentrations of lead (up to 36,000 mg L(-1)); however, the mechanisms of sorption varied according to the characteristics of each material: degree of decomposition, pH, cation exchange capacity and percentage of organic matter. Vermicompost and manure removed 98% of the Pb from solution. Lead precipitated in manure and vermicompost, forming lead oxide (PbO) and lead ferrite (PbFe4O7). Adsorption isotherms did not fit to the typical Freundlich and Langmuir equations. Not only specific and non-specific adsorption was observed, but also precipitation and coprecipitation. Lead desorption from vermicompost and cow manure was less than 2%. For remediation of Pb-polluted sites, the application of vermicompost and manure is recommended in places with alkaline soils because Pb precipitation can be induced, whereas coffee pulp residue is recommended for acidic soils where Pb is adsorbed.

  12. The effect of lead in bone densitometry

    Science.gov (United States)

    Popovic, Marija; McNeill, Fiona E.; Webber, Colin E.; Chettle, David R.

    2004-01-01

    Dual energy X-ray absorptiometry (DXA) is presently considered the standard technique for diagnosis of osteoporosis. It has been suggested that the presence of lead interferes with the accurate measurement of bone mineral density (BMD) by DXA because of the increased attenuation and that an accurate measurement of BMD cannot be determined unless the patient's bone lead content of patients is known. We performed DXA measurements on plaster of Paris phantoms and a Hologic Spine phantom in combination with polyester resin doped with various concentrations of lead. At lead levels which correspond to bone concentrations in occupationally exposed individuals, the suggested increase in densitometric BMD was not detected. Numerical calculations show that the effect of the lead depends upon the two energies of the X-ray beam of a particular device. The discrepancy between the actual and the densitometric BMD increases linearly and is about 0.3% at 100 ppm. Such change cannot be detected by the Hologic QDR 4500A, the device used for this experiment.

  13. The Identification and Synthesis of Lead Apatite Minerals Formed in Lead Water Pipes

    Directory of Open Access Journals (Sweden)

    Jeremy D. Hopwood

    2016-01-01

    Full Text Available Phosphate is added to drinking water in the UK to minimise the release of lead from lead water pipes. The phosphate encourages the formation of insoluble lead apatites on the walls of the pipe. Hydroxylpyromorphite Pb5(PO43OH is the lead apatite that is most often used to model lead levels in tap water; however, its presence has not been confirmed. Our aims were to identify the lead pipe apatite and synthesise it. The synthetic mineral would then be used in future solubility studies to produce better predictions of lead levels in tap water. XRD and FTIR were used to characterise the minerals on a range of lead pipes. Pyromorphite and hydroxylpyromorphite were absent and instead a range of mixed calcium lead apatites were present. For every five lead ions in the general formula Pb5(PO43X between one and two ions were replaced with calcium and there was evidence of substitution of PO43- by either CO32- or HPO42-. Calcium lead apatites with similar unit cell dimensions to those found on lead water pipes were then synthesised. The calcium : lead ratio in these reaction mixtures was in excess of 500 : 1 and the resulting crystals were shown by TEM to be nanosized rods and flakes. The synthetic apatites that most closely resembled the unit cell dimensions of the apatites on lead water pipes were shown to be Pb3.4Ca1.3(PO43Cl0.03OH0.97, Pb3.6Ca1.2(PO43Cl0.07OH0.93, and Pb3.6Ca1.2(PO43Cl0.27OH0.73.

  14. Stable lead isotopic analyses of historic and contemporary lead contamination of San Francisco Bay estuary

    Science.gov (United States)

    Ritson, P.I.; Bouse, R.M.; Flegal, A.R.; Luoma, S.N.

    1999-01-01

    Variations in stable lead isotopic composition (240Pb, 206Pb, 207Pb, 208Pb) in three sediment cores from the San Francisco Bay estuary document temporal changes in sources of lead during the past two centuries. Sediment, with lead from natural geologic sources, and relatively homogeneous lead isotopic compositions are overlain by sediments whose isotopic compositions indicate change in the sources of lead associated with anthropogenic modification of the estuary. The first perturbations of lead isotopic composition in the cores occur in the late 1800s concordant with the beginning of industrialization around the estuary. Large isotopic shifts, toward lower 206Pb/207Pb, occur after the turn of the century in both Richardson and San Pablo Bays. A similar relationship among lead isotopic compositions and lead concentrations in both Bays suggest contamination from the same source (a lead smelter). The uppermost sediments (post 1980) of all cores also have a relatively homogenous lead isotopic composition distinct from pre-anthropogenic and recent aerosol signatures. Lead isotopic compositions of leachates from fourteen surface sediments and five marsh samples from the estuary were also analyzed. These analyses suggest that the lead isotopic signature identified in the upper horizons of the cores is spatially homogeneous among recently deposited sediments throughout the estuary. Current aerosol lead isotopic compositions [Smith, D.R., Niemeyer, S., Flegal, A.R., 1992. Lead sources to California sea otters: industrial inputs circumvent natural lead biodepletion mechanisms. Environmental Research 57, 163-175] are distinct from the isotopic compositions of the surface sediments, suggesting that the major source of lead is cycling of historically contaminated sediments back through the water column. Both the upper core sediments and surface sediments apparently derive their lead predominantly from sources internal to the estuary. These results support the idea that

  15. Thermoforming plastic in lead shield construction

    Energy Technology Data Exchange (ETDEWEB)

    Abrahams, M.E.; Chow, C.H.; Loyd, M.D. (Univ. of Texas Medical Branch, Galveston (USA))

    1989-09-01

    Radiation treatments using low energy X-rays or electrons frequently require a final field defining shield to be placed on the patient's skin. A custom made lead cut-out is used to provide a close fit to a particular patient's surface contours. We have developed a procedure which utilizes POLYFORM thermoplastic to obtain a negative mold of the patient instead of the traditional plaster bandage or dental impression gel. The Polyform is softened in warm water, molded carefully over the patient's surface, and is removed when set or hardened, usually within five minutes. Then lead sheet cut-outs can be formed within this negative. For shielding cut-outs requiring thicker lead sheet, a positive is made from dental stone using this Polyform negative. We have found this procedure to be neat, fast and comfortable for both patient and the dosimetrist.

  16. Thermoforming plastic in lead shield construction.

    Science.gov (United States)

    Abrahams, M E; Chow, C H; Loyd, M D

    1989-09-01

    Radiation treatments using low energy X-rays or electrons frequently require a final field defining shield to be placed on the patient's skin. A custom made lead cut-out is used to provide a close fit to a particular patient's surface contours. We have developed a procedure which utilizes POLYFORM thermoplastic to obtain a negative mold of the patient instead of the traditional plaster bandage or dental impression gel. The Polyform is softened in warm water, molded carefully over the patient's surface, and is removed when "set" or hardened, usually within five minutes. Then lead sheet cut-outs can be formed within this negative. For shielding cut-outs requiring thicker lead sheet, a positive is made from dental stone using this Polyform negative. We have found this procedure to be neat, fast and comfortable for both patient and the dosimetrist.

  17. Fast charging of lead/acid batteries

    Energy Technology Data Exchange (ETDEWEB)

    Calasanzio, D. (FIAMM SpA, Montecchio Maggiore (Italy)); Maja, M. (Polytechnical Univ., Turin (Italy). Dept. of Materials Science and Chemical Engineering); Spinelli, P. (Polytechnical Univ., Turin (Italy). Dept. of Materials Science and Chemical Engineering)

    1993-10-15

    A key point in the development of storage batteries for electric vehicles (EVs) is the possibility for fast recharging. It is widely recognized that the lead/acid system represents an excellent candidate for EVs because of the low cost, durability, and expectance of improvements in the near future. The viability of the lead/acid battery for EV applications would be greatly enhanced if fast recharging could be applied to the system without shortening its life. The present paper reports the results obtained by simulating the charging behaviour with a mathematical model that is capable of predicting the behaviour of nonconventional lead/acid cells both on discharge and recharge. The effects of important parameters such as plate dimensions, acid distribution, and porosity of the active mass are taken into account. The data obtained with the simulation are compared with results got from fast-recharge testing of commercial batteries. (orig.)

  18. Industrial dynamics beyond the lead firms

    DEFF Research Database (Denmark)

    Haakonsson, Stine Jessen; Slepniov, Dmitrij

    for market access or on innovation, capability building and technology transfer in the industry. The main objective of this paper is to look ‘beyond the lead firms’. We seek to advance the understanding of how the recent changes in the industry affect producers of key components and their role...... to develop new strategies, which involve internationalization. Our initial findings suggest that sub-suppliers get an initial impetus for internationalization from the lead firms. However, over time the sub-suppliers strategy changes as get more independent and driven by new business opportunities in China...... and link up with domestic lead firms. In pursuing the principal objectives of the paper, we combine two analytical frameworks for the outside-in perspectives of economic geography with the more inside-out perspective from international business and organizational studies. On the one hand, this combination...

  19. Industrial Dynamics Beyond the Lead Firms

    DEFF Research Database (Denmark)

    Haakonsson, Stine Jessen; Slepniov, Dmitrij

    2013-01-01

    for market access or on innovation, capability building and technology transfer in the industry. The main objective of this paper is to look ‘beyond the lead firms’. We seek to advance the understanding of how the recent changes in the industry affect producers of key components and their role...... to develop new strategies, which involve internationalization. Our initial findings suggest that sub-suppliers get an initial impetus for internationalization from the lead firms. However, over time the sub-suppliers strategy changes as get more independent and driven by new business opportunities in China...... and link up with domestic lead firms. In pursuing the principal objectives of the paper, we combine two analytical frameworks for the outside-in perspectives of economic geography with the more inside-out perspective from international business and organizational studies. On the one hand, this combination...

  20. Different Pathways Leading to Integrase Inhibitors Resistance

    Science.gov (United States)

    Thierry, Eloïse; Deprez, Eric; Delelis, Olivier

    2017-01-01

    Integrase strand-transfer inhibitors (INSTIs), such as raltegravir (RAL), elvitegravir, or dolutegravir (DTG), are efficient antiretroviral agents used in HIV treatment in order to inhibit retroviral integration. By contrast to RAL treatments leading to well-identified mutation resistance pathways at the integrase level, recent clinical studies report several cases of patients failing DTG treatment without clearly identified resistance mutation in the integrase gene raising questions for the mechanism behind the resistance. These compounds, by impairing the integration of HIV-1 viral DNA into the host DNA, lead to an accumulation of unintegrated circular viral DNA forms. This viral DNA could be at the origin of the INSTI resistance by two different ways. The first one, sustained by a recent report, involves 2-long terminal repeat circles integration and the second one involves expression of accumulated unintegrated viral DNA leading to a basal production of viral particles maintaining the viral information. PMID:28123383

  1. Thermodynamic modeling of lead blast furnace

    Institute of Scientific and Technical Information of China (English)

    TAN Peng-fu

    2005-01-01

    A thermodynamic model was developed to predict the distribution behavior of Cu,Fe,S,O,Pb,Zn,As,and the heat balance in a lead blast furnace.The modeling results are validated by the plant data of a lead smelter in Kazakhstan.The model can be used to predict any set of controllable process parameters such as feed composition,smelting temperature,degree of oxygen enrichment and volume of oxygen-enriched air.The effects of the blast air,industrial oxygen,and coke charge on the distribution of Cu,Fe,S,O,Pb,Zn,As,the heat balance,and the lead loss in slag,were presented and discussed.

  2. Sources for Leads: Natural Products and Libraries.

    Science.gov (United States)

    van Herwerden, Eric F; Süssmuth, Roderich D

    2016-01-01

    Natural products have traditionally been a major source of leads in the drug discovery process. However, the development of high-throughput screening led to an increased interest in synthetic methods that enabled the rapid construction of large libraries of molecules. This resulted in the termination or downscaling of many natural product research programs, but the chemical libraries did not necessarily produce a larger amount of drug leads. On one hand, this chapter explores the current state of natural product research within the drug discovery process. On the other hand it evaluates the efforts made to increase the amount of leads generated from chemical libraries and considers what role natural products could play here.

  3. Growth and characterization of lead bromide crystals

    Science.gov (United States)

    Singh, N. B.; Gottlieb, M.; Henningsen, T.; Hopkins, R. H.; Mazelsky, R.; Glicksman, M. E.; Coriell, S. R.; Santoro, G. J.; Duval, W. M. B.

    1992-01-01

    Lead(II) bromide was purified by a combination of directional freezing and zone-refining methods. Differential thermal analysis of the lead bromide showed that a destructive phase transformation occurs below the melting temperature. This transformation causes extensive cracking, making it very difficult to grow a large single crystal. Energy of phase transformation for pure lead bromide was determined to be 24.67 cal/g. To circumvent this limitation, crystals were doped by silver bromide which decreased the energy of phase transformation. The addition of silver helped in achieving the size, but enhanced the inhomogeneity in the crystal. The acoustic attenuation constant was almost identical for the pure and doped (below 3000 ppm) crystals.

  4. Lead Leached into Water from Select Plumbing Fixtures” Could Lead to Health Hazard

    Directory of Open Access Journals (Sweden)

    Ramsey Coles

    2014-01-01

    Full Text Available Background: Lead is an inert metal and is resistant to corrosion. It also increases tensile strength of many common materials in daily use. Lead was used during the Roman period to transport water (hence the name plumbing/plumber is common terminology even in the present day. Lead enters the biological system through the air, water, and dust. Fine particles of lead, having diameter less than 5 nm are directly absorbed by lungs. Inorganic lead is absorbed by the gastrointestinal tract, and organic lead is absorbed by the skin. Lead has long been known to be a toxic heavy metal and exposure is associated with many deleterious health effects. Still, lead remains a popular ingredient in products ranging from paint to batteries. The lead content in any given material is estimated using various methods. The least cumbersome method is found to be X-Ray Fluorescence technique (XRF. A portable XRF device was used in the present study. Aim: The main aim of this study to investigate whether lead is present in various commonly used plumbing materials. Material and Methods: All types of branded and commonly used pipes were gathered from a market in Bangalore and tested using the XRF machine. In order to evaluate to what extent lead from the pipes could leach into water, seven pipes were randomly selected and filled with Aquafina water (having undetectable level of lead for a 24 hour period. This water was tested at an NABL accredited laboratory in Bangalore, India for lead content. Result: It was determined that lead was present in many of the samples, at an unacceptable levels ranging from, well above the globally accepted level of 0.01 mg/L proof that lead was able to leach from the samples into water. Conclusions: As lead in drinking water represents a direct pathway for human exposure, the authors recommend that significant measures be taken to prevent use of lead in the plumbing industry for prevention of it’s deleterious effects. Authors have also

  5. Embryotoxicity of lead on Bufo arenarum

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Coll, C.S.; Herkovits, J.; Salibian, A.

    1988-08-01

    Lead, one of the oldest and more widely distributed pollutants, produces serious toxicological effects. From an ecotoxicological point of view, amphibians are useful as indicators of environmental contamination because they are sensitive to a great variety of toxic agents. Considering that Bufo arenarum is one of the most widely distributed toads in South America, in the present work the authors study the LC50 and teratogenical effects of lead on Bufo arenarum embryos obtained from different couples of parents exposing them from the 2-cell stage onwards. A differential susceptibility to this heavy metal in embryos obtained from five different couples of parents is described.

  6. Lead Speciation in remote Mountain Lakes

    Science.gov (United States)

    Plöger, A.; van den Berg, C. M. G.

    2003-04-01

    In natural waters trace metals can become complexed by organic matter. This complexation can change the geochemistry of the metals by preventing them being scavenged, thereby increasing their residence time in the water column. The chemical speciation of trace metals also affects the bioavalability and their toxicological impact on organisms. It is therefore important to determine the chemical speciation of trace metals as well as their concentrations. Mountain lakes have been less studied in the past than other lakes- partly because of their remoteness and partly because they were perceived to be unpolluted and undisturbed. But work so far on mountain lakes has shown that most sites are affected and threatened, for example by transboundary air pollutants like trace metals. One of the important features that distinguishes these lakes from lowland lakes at similar latitudes is the fact that they may be isolated from the atmosphere for six months or more during the winter by a thick ice cover. Also, as these lakes are remote from direct anthropogenic influences, they reflect the regional distribution of pollutants transferred via the atmosphere. For this work, under the framework of the EMERGE (European Mountain lake Ecosystems: Regionalisation, diaGnostic and socio-economic Evaluation) programme, two remote mountain lakes have been studied in detail, with water sampling taking place at different times of the year to investigate possible seasonal differences in lead concentrations and speciation. Results so far have shown that lead-complexing ligand concentrations are in excess to dissolved lead concentrations, indicating that dissolved lead probably occurs fully complexed in these lakes. Therefore the toxic fraction is likely to be less than the dissolved lead concentration. Also, lead concentrations at the time of the spring thaw are higher than autumn concentrations just before ice cover, indicating that a significant proportion of fallout onto the lake catchment

  7. Asbestos, lead, and the family: household risks

    Energy Technology Data Exchange (ETDEWEB)

    Fischbein, A.; Cohn, J.; Ackerman, G.

    1980-06-01

    Although the intrafamilial transmission of infectious diseases has long been recognized, the induction of environmental disease in household contacts is being increasingly documented and requires a higher index of suspicion. An incidental radiographic finding, such as pleural thickening or calcification, or even interstitial pulmonary fibrosis in a young person without obvious occupational exposure to asbestos, should prompt the physician to clarify the parental occupational history. Likewise, unexpected evidence of lead induced abnormalities, such as elevated blood lead and/or erythrocyte protoporphyrin levels, should focus the examiner's attention on possible intrafamilial transmission, treatment, and prevention.

  8. Soil is an important pathway of human lead exposure.

    OpenAIRE

    Mielke, H W; Reagan, P L

    1998-01-01

    This review shows the equal or greater importance of leaded gasoline-contaminated dust compared to lead-based paint to the child lead problem, and that soil lead, resulting from leaded gasoline and pulverized lead-based paint, is at least or more important than lead-based paint (intact and not pulverized) as a pathway of human lead exposure. Because lead-based paint is a high-dose source, the biologically relevant dosage is similar to lead in soil. Both lead-based paint and soil lead are asso...

  9. Lead shot from hunting as a source of lead in human blood

    Energy Technology Data Exchange (ETDEWEB)

    Johansen, Poul [National Environmental Research Institute, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)]. E-mail: poj@dmu.dk; Pedersen, Henning Sloth [Primary Health Care Center, DK-3900 Nuuk (Greenland); Asmund, Gert [National Environmental Research Institute, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Riget, Frank [National Environmental Research Institute, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)

    2006-07-15

    This study investigates the relationship between the intake of birds hunted with lead shot and the lead concentration in human blood. Fifty adult men from Nuuk, Greenland took part in the study. From September 2003 to June 2004 they regularly gave blood samples and recorded how many birds they ate. We found a clear relationship between the number of bird meals and blood lead and also a clear seasonal variation. The concentration was highest in mid-winter when bird consumption is at its highest. Blood lead was low (15 {mu}g/L, mean concentration) among the participants reporting not eating birds. Among those reporting to eat birds regularly, blood lead was significantly higher, up to 128 {mu}g/L (mean concentration). Concentrations depended on the frequency of bird meals: the more the bird meals, the higher the resulting blood lead. This clear relationship points to lead shot as the dominating lead source to people in Greenland. - Birds hunted with lead shot and consumed are a source of lead in human blood.

  10. Effect of flow rate and lead/copper pipe sequence on lead release from service lines.

    Science.gov (United States)

    Cartier, Clément; Arnold, Roger B; Triantafyllidou, Simoni; Prévost, Michèle; Edwards, Marc

    2012-09-01

    A pilot experiment examined lead leaching from four representative configurations of service lines including: (1) 100% lead (Pb), (2) 100% copper (Cu), (3) 50% Pb upstream of 50% Cu, and (4) 50% Pb-downstream of 50% Cu using a range of flow rates. The cumulative mass of lead release indicated that a typical partial replacement configuration (50% lead downstream of copper) did not provide a net reduction in lead when compared to 100% lead pipe (85 mg for 50% Pb-downstream versus 83 mg for 100%-Pb) due to galvanic and deposition corrosion. The partially replaced service line configuration also had a much greater likelihood of producing water with "spikes" of lead particulates at higher flow rates, while tending to produce lower levels of lead at very low flow rates. After the first 214 days the galvanic current between copper and lead was only reduced by 34%, proving that galvanic impacts can be highly persistent even in water with optimized corrosion control by dosing of zinc orthophosphate. Finally, this experiment raises concern about the low flow rates used during some prior home sampling events, which may underestimate exposure to lead during normal water use, especially when galvanic Pb:Cu connections are present.

  11. Chronic lead poisoning in steers eating silage contaminated with lead shot - diagnostic criteria

    Energy Technology Data Exchange (ETDEWEB)

    Rice, D.A.; McLoughlin, M.F.; Blanchflower, W.J.; Thompson, T.R.

    1987-10-01

    Lead ingestion is one of the most common causes of poisoning in cattle. Toxicity results most commonly from the consumption of a single high dose of lead although cumulative toxicity resulting from the ingestion of small doses over a prolonged time also occurs. The sources of lead most commonly involved in disease outbreaks are paint, batteries, felt, linoleum and oil. It has traditionally been held that ingested metallic lead does not present a major toxicity risk to cattle because of its low solubility in the rumen and reticulum. More recent evidence suggests that lead shot, if present in silage, can induce toxicity when such silage is eaten by cattle. This communication describes a poisoning outbreak in steers eating lead shot contaminated grass silage. It presents and discusses the limitations of the criteria used for arriving at a diagnosis, including the use of whole blood amino levulinic acid dehydratase (ALAD) concentrations in fresh whole blood and after reactivation with dithiothreitol. Three are differences of opinion, in the literature, regarding the response of erythrocyte ALAD to ingested lead in the bovine. Consequently the results of a small lead feeding trial are also reported here. These results demonstrate a large ALAD response to lead ingestion and justify the use of this test in the confirmation of field cases of lead poisoning in cattle such as the one reported here.

  12. Effect of lead foam grid on performance of lead-acid battery

    Institute of Scientific and Technical Information of China (English)

    DAI Chang-song; WANG Dian-long; HU Xin-guo; JIANG Zhao-hua; YAN Zhi-gang

    2005-01-01

    In order to increase the specific energy and specific power of a lead-acid battery, lead foam grid was prepared by electrodepositing Pb-Sn alloy on a copper foam substrate and used as negative current collector for a lead acid battery whose capacity was limited by the negative plate. Comparing the effect of the cast grid, under the same conditions, the mass of lead foam grid decreases by 35% , and the area of lead foam contacted with active material increases by about 20 times. Under 2 h rate discharge condition, with a high current (3.0 I2 ) e and low-temperature ( - 10 ℃, I2 ) discharge system, the lead foam grid markedly boosts the discharge performance of lead acid battery. It increases not only the negative electrode mass specific capacity by 27% ,37%and 29% ,but also the utilization efficiency of the negative active material by 5%. Compared with the negative electrode of cast grid, XRD and SEM results show that after 20 cycles at the state of charge, the sponge lead in the negative lead foam electrode has smaller crystals and less PbSO4 on its surface. Meanwhile, at the state of full discharge, the PbSO4 crystals are smaller and occur less on the surface of lead foam electrode. This indicates its active material reacts more uniformly.

  13. Blood Lead Levels and Health Problems of Lead Acid Battery Workers in Bangladesh

    Directory of Open Access Journals (Sweden)

    Sk. Akhtar Ahmad

    2014-01-01

    Full Text Available Introduction. Use of lead acid battery (LAB in Bangladesh has risen with sharp rise of motor vehicles. As result, manufacture of LAB is increasing. Most of the lead used by these industries comes from recycling of LAB. Workers in LAB industry are at risk of exposure lead and thus development of lead toxicity. Objective. The objective of this study was to measure the blood lead concentration and to assess the magnitude of health problems attributable to lead toxicity among the LAB manufacturing workers. Methods. A cross-sectional study was conducted among the workers of LAB manufacturing industries located in Dhaka city. Result. Mean blood lead level (BLL among the workers was found to be high. They were found to be suffering from a number of illnesses attributable to lead toxicity. The common illnesses were frequent headache, numbness of the limbs, colic pain, nausea, tremor, and lead line on the gum. High BLL was also found to be related to hypertension and anemia of the workers. Conclusion. High BLL and illnesses attributable to lead toxicity were prevalent amongst workers of the LAB manufacturing industries, and this requires attention especially in terms of occupational hygiene and safety.

  14. High medical consultation rates of lead workers after industrial dispute over lead effects

    Energy Technology Data Exchange (ETDEWEB)

    Araki, S.; Murata, K.; Yanagihara, S.; Ushio, K.

    1982-02-01

    Medical consultation rates were compared between a group of lead workers and two groups of non-lead workers in a newspaper company where a serious industrial dispute took place over health effects of lead three years before this study. The comparison was also made within the group of lead workers. Maximal blood lead concentrations (PbBs) ranged from 0.1 ..mu..mol/kg to 3.6 ..mu..mol/kg with an average of 1.3 ..mu..mol/kg in the past three years. The consultation rate of lead workers was significantly higher than that of both the non-lead workers, when the number of workers who consulted physicians or dentists once or more for a year per 100 workers was compared. Disease-specific consultation rates were also higher in lead workers for seven categories of diseases and injuries such as hypertensive disease and peptic ulcers. When lead workers were divided into three groups by PbB or erythrocytes delta-aminolevulinic acid dehydratase (ALAD) levels, however, no significantly high rate was found in the higher PbB groups nor lower ALAD groups in terms of general and disease-specific consultation rates. It was concluded that the industrial dispute might have been a major cause of the high consultation rate of lead workers.

  15. Communication as Relational Practice of Leading

    DEFF Research Database (Denmark)

    Hansen, Lone Hersted; Larsen, Mette Vinther; Rasmussen, Jørgen Gulddahl

    2015-01-01

    This chapter highlights how communication, especially leadership communication, can be understood and practised within a relational perspective. An analysis of a specific example of communication forms the basis for a discussion of six central themes that we consider significant in a relational...... understanding of communication and leading. The chapter ends with a discussion of how leadership communication can be understood as polyphony of voices....

  16. NIH Research Leads to Cervical Cancer Vaccine

    Science.gov (United States)

    ... Current Issue Past Issues Sexually Transmitted Diseases NIH Research Leads to Cervical Cancer Vaccine Past Issues / Fall 2008 Table of Contents For ... mystery. Most important, however, is to have a vaccine which potentially can ... focusing their research on helping to produce second-generation HPV vaccines ...

  17. Lead free solder mechanics and reliability

    CERN Document Server

    Pang, John Hock Lye

    2012-01-01

    Lead-free solders are used extensively as interconnection materials in electronic assemblies and play a critical role in the global semiconductor packaging and electronics manufacturing industry. Electronic products such as smart phones, notebooks and high performance computers rely on lead-free solder joints to connect IC chip components to printed circuit boards. Lead Free Solder: Mechanics and Reliability provides in-depth design knowledge on lead-free solder elastic-plastic-creep and strain-rate dependent deformation behavior and its application in failure assessment of solder joint reliability. It includes coverage of advanced mechanics of materials theory and experiments, mechanical properties of solder and solder joint specimens, constitutive models for solder deformation behavior; numerical modeling and simulation of solder joint failure subject to thermal cycling, mechanical bending fatigue, vibration fatigue and board-level drop impact tests. This book also: Discusses the mechanical prope...

  18. Leading-Edge Vortex lifts swifts

    NARCIS (Netherlands)

    Videler, JJ; Stamhuis, EJ; Povel, GDE

    2004-01-01

    The current understanding of how birds fly must be revised, because birds use their hand-wings in an unconventional way to generate lift and drag. Physical models of a common swift wing in gliding posture with a 60degrees sweep of the sharp hand-wing leading edge were tested in a water tunnel. Inter

  19. Cross-stimulation during lead impedance monitoring

    NARCIS (Netherlands)

    Beaufort-Krol, GCM; Bink-Boelkens, MTE; Nagelkerke, D; van Gelder, BM

    2001-01-01

    At the age of 4 years, a total cavopulmonary connection was performed in a boy with a complex congenital heart defect. On addition, a DDDR pacemaker was implanted for sick sinus syndrome. Atrial and ventricular leads were epicardially placed at the left atrium and left ventricle. At the age of 10 ye

  20. Proton beam modification of lead white pigments

    Energy Technology Data Exchange (ETDEWEB)

    Beck, L., E-mail: lucile.beck@cea.fr [CEA, DEN, Service de Recherches de Métallurgie Physique, Laboratoire JANNUS, 91191 Gif-sur-Yvette (France); Centre de recherche et de restauration des musées de France (C2RMF), Palais du Louvre – Porte des Lions, 14 quai François Mitterrand, 75001 Paris (France); Gutiérrez, P.C. [Centre de recherche et de restauration des musées de France (C2RMF), Palais du Louvre – Porte des Lions, 14 quai François Mitterrand, 75001 Paris (France); Centro de Micro-Análisis de Materiales (CMAM), Universidad Autónoma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain); Miserque, F. [CEA, DEN, DPC/SCCME/LECA, 91191 Gif-sur-Yvette (France); Thomé, L. [Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), CNRS/IN2P3 et Université Paris-Sud, Bât. 108, 91405 Orsay (France)

    2013-07-15

    Pigments and paint materials are known to be sensitive to particle irradiation. Occasionally, the analysis of paintings by PIXE can induce a slight or dark stain depending on the experimental conditions (beam current, dose, particle energy). In order to understand this discoloration, we have irradiated various types of art white pigments – lead white (hydrocerussite and basic lead sulfate), gypsum, calcite, zinc oxide and titanium oxide – with an external 3 MeV proton micro-beam commonly used for PIXE experiments. We have observed various sensitivities depending on the pigment. No visible change occurs for calcite and titanium oxide, whereas lead white pigments are very sensitive. For the majority of the studied compounds, the discoloration is proportional to the beam current and charge. The damage induced by proton beam irradiation in lead white pigments was studied by micro-Raman and XPS spectroscopies. Structural modifications and dehydration were detected. Damage recovery was investigated by thermal treatment and UV-light irradiation. The discoloration disappeared after one week of UV illumination, showing that PIXE experiments could be safely undertaken for pigments and paintings.

  1. 30 CFR 18.37 - Lead entrances.

    Science.gov (United States)

    2010-07-01

    ... against loosening. (d) Compressed packing material shall be in contact with the cable jacket for a length... cable jacket and the nominal inside diameter of the packing material shall not exceed 1/32-inch, based... § 18.37 Lead entrances. (a) Insulated cable(s), which must extend through an outside wall of...

  2. Improved light yield of lead tungstate scintillators

    CERN Document Server

    Annenkov, A N; Hofstäetter, A; Korzhik, M V; Ligun, V; Lecoq, P; Missevitch, O V; Novotny, R; Peigneux, J P

    2000-01-01

    The application at medium and low energies of lead tungstate scintillators, so far optimized for the ECAL calorimeter of CMS for the future LHC, is strongly limited by their poor light yield. Suitable dopants like molybdenum and terbium can help to overcome this problem. Concepts, results, advantages and drawbacks of this approach are discussed. (11 refs).

  3. When Teachers Lead. UCEA Monograph Series.

    Science.gov (United States)

    Astuto, Terry A., Ed.

    This document contains six chapters that examine the role of teacher leadership in the school-restructuring process. Chapter 1, "When--Teachers Lead" (Bruce S. Cooper), provides a general introduction to the content and purpose of the monograph. Chapter 2, "When--Teachers Share School-Level Decision-Making" (Sharon Conley and Justo Robles),…

  4. Easier Said than Done: Leading Technology Integration

    Science.gov (United States)

    Bleakley, David A.; Mangin, Melinda M.

    2013-01-01

    In this case, Mr. Phuture, a district administrator, attempts to lead a diverse team of educators and community members in an effort to develop a district-wide action plan for the integration of instructional technology in K-12 classrooms. Along the way, Mr. Phuture confronts ambiguities in the superintendent's directives, passionate contradicting…

  5. Leading-Edge Learning: Two Views.

    Science.gov (United States)

    Abernathy, Donna J.

    1999-01-01

    Peter Senge and Jack Welch share thoughts about what it means to learn and lead into the next century. Senge urges leaders to be aware of the economic and the natural environment. Welch asserts that an organization's ability to learn and translate learning into action is the ultimate competitive advantage. (JOW)

  6. Energy transfer phenomena in lead sulphate

    NARCIS (Netherlands)

    Blasse, G.

    1975-01-01

    It is shown that lead sulphate, PbSO4, shows Pb2+ emission with a large Stokes shift. Energy transfer has been observed from the Pb2+ ions to several luminescent centres, viz., tungstate, molybdate, vanadate and rare earths. No transfer occurs to the Pr3+ ion.

  7. Performance of lead-free versus lead-based hunting ammunition in ballistic soap.

    Directory of Open Access Journals (Sweden)

    Felix Gremse

    Full Text Available BACKGROUND: Lead-free hunting bullets are an alternative to lead-containing bullets which cause health risks for humans and endangered scavenging raptors through lead ingestion. However, doubts concerning the effectiveness of lead-free hunting bullets hinder the wide-spread acceptance in the hunting and wildlife management community. METHODS: We performed terminal ballistic experiments under standardized conditions with ballistic soap as surrogate for game animal tissue to characterize dimensionally stable, partially fragmenting, and deforming lead-free bullets and one commonly used lead-containing bullet. The permanent cavities created in soap blocks are used as a measure for the potential wound damage. The soap blocks were imaged using computed tomography to assess the volume and shape of the cavity and the number of fragments. Shots were performed at different impact speeds, covering a realistic shooting range. Using 3D image segmentation, cavity volume, metal fragment count, deflection angle, and depth of maximum damage were determined. Shots were repeated to investigate the reproducibility of ballistic soap experiments. RESULTS: All bullets showed an increasing cavity volume with increasing deposited energy. The dimensionally stable and fragmenting lead-free bullets achieved a constant conversion ratio while the deforming copper and lead-containing bullets showed a ratio, which increases linearly with the total deposited energy. The lead-containing bullet created hundreds of fragments and significantly more fragments than the lead-free bullets. The deflection angle was significantly higher for the dimensionally stable bullet due to its tumbling behavior and was similarly low for the other bullets. The deforming bullets achieved higher reproducibility than the fragmenting and dimensionally stable bullets. CONCLUSION: The deforming lead-free bullet closely resembled the deforming lead-containing bullet in terms of energy conversion

  8. High medical consultation rates of lead workers after industrial dispute over lead effects

    Energy Technology Data Exchange (ETDEWEB)

    Araki, S.; Murata, K.; Yanagihara, S.; Ushio, K.

    1982-02-01

    Medical consultation rates were compared between a group of lead workers (346 males) and two groups of non-lead workers (317 and 329 males) in a newspaper company where a serious industrial dispute took place over health effects of lead three years before this study. The comparison was also made within the group of lead workers. Maximal blood lead concentrations (PbBs) ranged from 0.1 mumol/kg to 3.6 mumol/kg (74 microgram/100 g) with an average of 1.3 mumol/kg in the past three years. Ages averaged 35 years in lead workers, and 34 and 30 years in non-lead workers, the ranges being 19-55 years in all. The consultation rate of lead workers was significantly higher than that of both the non-lead workers (P less than 0.001), when the number of workers who consulted physicians or dentists once or more for a year per 100 workers (general consultation rate) was compared. Disease-specific consultation rates were also higher in lead workers for seven categories of diseases and injuries such as hypertensive disease and peptic ulcers. When lead workers were divided into three groups by PbB or erythrocytes delta-aminolevulinic acid dehydratase (ALAD) levels, however, no significantly high rate was found in the higher PhB groups not lower ALAD groups in terms of general and disease-specific consultation rates. It was concluded that the industrial dispute might have been a major cause of the high consultation rate of lead workers.

  9. Antiviral lead compounds from marine sponges

    KAUST Repository

    Sagar, Sunil

    2010-10-11

    Marine sponges are currently one of the richest sources of pharmacologically active compounds found in the marine environment. These bioactive molecules are often secondary metabolites, whose main function is to enable and/or modulate cellular communication and defense. They are usually produced by functional enzyme clusters in sponges and/or their associated symbiotic microorganisms. Natural product lead compounds from sponges have often been found to be promising pharmaceutical agents. Several of them have successfully been approved as antiviral agents for clinical use or have been advanced to the late stages of clinical trials. Most of these drugs are used for the treatment of human immunodeficiency virus (HIV) and herpes simplex virus (HSV). The most important antiviral lead of marine origin reported thus far is nucleoside Ara-A (vidarabine) isolated from sponge Tethya crypta. It inhibits viral DNA polymerase and DNA synthesis of herpes, vaccinica and varicella zoster viruses. However due to the discovery of new types of viruses and emergence of drug resistant strains, it is necessary to develop new antiviral lead compounds continuously. Several sponge derived antiviral lead compounds which are hopedto be developed as future drugs are discussed in this review. Supply problems are usually the major bottleneck to the development of these compounds as drugs during clinical trials. However advances in the field of metagenomics and high throughput microbial cultivation has raised the possibility that these techniques could lead to the cost-effective large scale production of such compounds. Perspectives on biotechnological methods with respect to marine drug development are also discussed. 2010 by the authors; licensee MDPI.

  10. Lead and cadmium in breast milk

    Energy Technology Data Exchange (ETDEWEB)

    Sternowsky, H.J.; Wessolowski, R.

    1985-04-01

    Breast milk from 10 women each from the city of Hamburg and from a rural area was analyzed by atomic absorption spectrometry for contamination with lead and cadmium. Samples were examined at regular intervals for 3 months after birth. On day 5 a diurnal profile was analyzed; on the other days milk was taken before and after the morning feed. For breast milk as the main source of nutrition in infants, this study shows values of 9.1 +- 2.5 (SD) ..mu..g/l for lead in the rural population, with a tendency to decrease towards the end of lactation. Urban mothers had 13.3 +- 5.5 (SD) ..mu..g/l, with a tendency to increase. Mean cadmium content in rural mothers was 17.3 +- 4.9 ..mu..g/l, with much higher values in the colostrum and a decrease after 15 days. Urban mothers had 24.6 +- 7.3 ..mu..g/l, again with high colostrum values and a subsequent decrease. Calculated daily intake according to these values is presented, based on 840 ml breast milk for a 5.5 kg infant per day. Rural infants ingested 0.9-1.3 ..mu..g/kg/day of lead, and in the city 1.5-2.3 ..mu..g/kg/day. Cadmium intake in rural infants amounted from 1.2-1.8 ..mu..g/kg/day; in Hamburg it was 1.6-2.2 ..mu..g/kg/day. Thus the daily ingestion of lead was just below the DPI, cadmium ingestion was higher than the DPI for adults. The rural population had lower values in breast milk for both heavy metals than the urban population, although not statistically significant. Compared to earlier reports there was a slight increase in lead concentration and a more significant increase for cadmium.

  11. Blood lead levels of British competitive cyclists.

    Science.gov (United States)

    Atkinson, G; Maclaren, D; Taylor, C

    1994-01-01

    This study examined the extent to which the potentially toxic lead particulates emitted from motor vehicles are absorbed by competitive cyclists. A time trial (n = 5), a road race (n = 5), and a sedentary control group (n = 5) were examined with respect to blood lead (PbB) levels. In the two cycling groups, the PbB levels were measured before and after (1) a time trial (80 km) held on a dual carriageway; and (2) a road race (120 km) which took place in a rural area. Mean (+/- SE) resting PbB levels for the sedentary subjects, time trialists, and road racers were 0.442 +/- 0.041, 0.490 +/- 0.111 and 0.384 +/- 0.061 mumol l-1 respectively (p > 0.05). Mean post-race PbB levels of the time trialists (0.528 +/- 0.046 mumol l-1) and road racers (0.346 +/- 0.024 mumol l-1) did not differ significantly from the pre-race levels (p > 0.05). However, after their respective races, the mean PbB level of the time trialists was higher than that of the road racers (p cycling (70% VO2 max) in a laboratory containing approximately 1 microgram m3 of airborne lead did not affect blood lead levels. All PbB levels compiled with EC regulations regarding lead exposure. Despite a positive relationship between the amount of training and the PbB levels (r = 0.64, p road racing.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Performance characteristics of lead oxides in pasted lead/acid battery electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Afifi, S.E. (Electrometallurgy Lab., Central Metallurgical Research and Development Inst., Cairo (Egypt)); Saba, A.E. (Electrometallurgy Lab., Central Metallurgical Research and Development Inst., Cairo (Egypt)); Shenouda, A.Y. (Electrometallurgy Lab., Central Metallurgical Research and Development Inst., Cairo (Egypt))

    1993-10-15

    The performance characteristics of lead oxides used for the pasted type of lead/acid battery plate have been investigated. The [alpha]- and [beta]-PbO polymorphs have been prepared carefully and used for pasting model electrodes. The factors that may affect the electrical capacity of such electrodes have been studied. These are: the type of oxide; percentage of free lead; additives such as carboxymethyl cellulose, zeolite and graphite. Lead hydroxide has also been studied with special attention. Photomicrographs have been taken to examine the crystal forms that develop on the electrode surface. Finally, some industrial samples have been investigated. (orig.)

  13. Investigation and Evaluation of Children's Blood Lead Levels around a Lead Battery Factory and Influencing Factors.

    Science.gov (United States)

    Zhang, Feng; Liu, Yang; Zhang, Hengdong; Ban, Yonghong; Wang, Jianfeng; Liu, Jian; Zhong, Lixing; Chen, Xianwen; Zhu, Baoli

    2016-05-28

    Lead pollution incidents have occurred frequently in mainland China, which has caused many lead poisoning incidents. This paper took a battery recycling factory as the subject, and focused on measuring the blood lead levels of environmental samples and all the children living around the factory, and analyzed the relationship between them. We collected blood samples from the surrounding residential area, as well as soil, water, vegetables. The atomic absorption method was applied to measure the lead content in these samples. The basic information of the generation procedure, operation type, habit and personal protect equipment was collected by an occupational hygiene investigation. Blood lead levels in 43.12% of the subjects exceeded 100 μg/L. The 50th and the 95th percentiles were 89 μg/L and 232 μg/L for blood lead levels in children, respectively, and the geometric mean was 94 μg/L. Children were stratified into groups by age, gender, parents' occupation, distance and direction from the recycling plant. The difference of blood lead levels between groups was significant (p factory, the higher the value of BLL and lead levels in vegetable and environment samples. The lead level in the environmental samples was higher downwind of the recycling plant.

  14. Lead pellet ingestion and liver-lead concentrations in upland game birds from southern Ontario, Canada.

    Science.gov (United States)

    Kreager, N; Wainman, B C; Jayasinghe, R K; Tsuji, L J S

    2008-02-01

    One-hundred twenty-three gizzards from upland game birds (chukar, Alectoris chukar; and common pheasant, Phasianus colchicus) harvested by hunters in southern Ontario, Canada, were examined for lead pellet ingestion by manual examination of gizzard contents and by radiography. Lead pellets were found to be ingested by chukars (6/76; 8%) and the common pheasant (16/47; 34%). Further, 13% (17/129) of the bird (wild turkey, Meleagris gallopavo; Hungarian partridge, Perdix perdix; chukar; and common pheasant) livers analyzed had elevated lead concentrations (> or =6 microg/g wet weight [ww]). Liver-lead concentrations above Health Canada's guideline for human consumption of fish protein (shotshell for hunting.

  15. Lead hazard among ironworkers: dismantling lead-painted elevated subway line in New York City

    Energy Technology Data Exchange (ETDEWEB)

    Fischbein, A.; Daum, S.M.; Davidow, B.

    1978-07-01

    Flame cutting of lead-painted steel structures may be associated with considerable lead exposure. In this study, an outbreak of lead poisoning among ironworkers dismantling an elevated subway line in New York City is described. Industrial hygiene evaluation of the respirators showed that inadequate equipment was the cause of the subsequent occupational disease. In the assessment of the lead-induced effects on the hematopoietic system, a new screening test--erythrocyte zinc protoporphyrin determination--was employed, utilizing a portable field device (hematofluorometer) on which an instantaneous reading of ZPP (zinc protoporphyrin) concentration is obtained. Correlative data between ZPP and blood lead are presented, demonstrating that ZPP determinations may improve and simplify the task of screening and monitoring populations chronically exposed to lead. The effect of lead on the biosynthesis of heme was also assessed in five workers, by investigating the functional capacity of the hepatic cytochrome P-450 system through drug metabolism studies before and after chelation therapy. The effect on this system was considered minimal. Environmental studies showed that very high amounts of lead dusts were generated by the demolition process, but did not present any significant hazard to people residing in the vicinity. It is emphasized that combined medical and industrial hygiene surveillance is essential for the safe management of such work operation, and workers engaged in such operations require proper respiratory equipment to minimize the risk of increased lead absorption.

  16. Preparation, Structural, Electrical, and Ferroelectric Properties of Lead Niobate–Lead Zirconate–Lead Titanate Ternary System

    Directory of Open Access Journals (Sweden)

    Rashmi Gupta

    2015-01-01

    Full Text Available A ternary system of lead niobate–lead zirconate–lead titanate with composition xPN–yPZ–(x-yPT where x=0.5 and y=0.15, 0.25, and 0.35 known as PNZT has been prepared by conventional mixed oxide route at a temperature of 1100°C. The formation of the perovskite phase was established by X-ray diffraction analysis. The surface morphology studied by scanning electron microscopy shows the formation of fairly dense grains and elemental composition was confirmed by energy dispersive X-ray analysis. Dielectric properties like dielectric constant and dielectric loss (ε′ and tan⁡δ indicate poly-dispersive nature of the material. The temperature dependent dielectric constant (ε′ curve indicates relaxor behaviour with two dielectric anomalies. The poly-dispersive nature of the material was analysed by Cole-Cole plots. The activation energy follows the Arrhenius law and is found to decrease with increasing frequency for each composition. The frequency dependence of ac conductivity follows the universal power law. The ac conductivity analysis suggests that hopping of charge carriers among the localized sites is responsible for electrical conduction. The ferroelectric studies reveal that these ternary systems are soft ferroelectric.

  17. Blood Lead Levels in Children and Environmental Lead Contamination in Miami Inner City, Florida

    Directory of Open Access Journals (Sweden)

    Theophile Niyonsenga

    2006-09-01

    Full Text Available Studies have shown that the environmental conditions of the home are important predictors of health, especially in low-income communities. Understanding the relationship between the environment and health is crucial in the management of certain diseases. One health outcome related to the home environment among urban, minority, and low-income children is childhood lead poisoning. The most common sources of lead exposure for children are lead paint in older, dilapidated housing and contaminated dust and soil produced by accumulated residue of leaded gasoline. Blood lead levels (BLL as low as 10 μg/dL in children are associated with impaired cognitive function, behavior difficulties, and reduced intelligence. Recently, it is suggested that the standard for intervention be lowered to BLL of 5 μg /dl. The objectives of our report were to assess the prevalence of lead poisoning among children under six years of age and to quantify and test the correlations between BLL in children and lead exposure levels in their environment. This cross-sectional analysis was restricted to 75 children under six years of age who lived in 6 zip code areas of inner city Miami. These locations exhibited unacceptably high levels of lead dust and soil in areas where children live and play. Using the 5 μg/dL as the cutoff point, the prevalence of lead poisoning among the study sample was 13.33%. The study revealed that lead levels in floor dust and window sill samples were positively and significantly correlated with BLL among children (p < 0.05. However, the correlations between BLL and the soil, air, and water samples were not significant. Based on this pilot study, a more comprehensive environmental study in surrounding inner city areas is warranted. Parental education on proper housecleaning techniques may also benefit those living in the high lead-exposed communities of inner city Miami.

  18. Australian atmospheric lead deposition reconstructed using lead concentrations and isotopic compositions of archival lichen and fungi.

    Science.gov (United States)

    Wu, Liqin; Taylor, Mark Patrick; Handley, Heather K; Wu, Michael

    2016-01-01

    Lead concentrations and their isotopic compositions were measured in lichen genera Cladonia and Usnea and fungi genus Trametes from the Greater Sydney region (New South Wales, Australia) that had been collected and archived over the past 120 years. The median lead contents were elevated in lichens and fungi prior to the introduction of leaded petrol (Cladonia 12.5 mg/kg; Usnea 15.6 mg/kg; Trametes 1.85 mg/kg) corresponding to early industrial development. During the use of leaded petrol for automobiles in Australia from 1932 to 2002, total median lead concentrations rose: Cladonia 18.8 mg/kg; Usnea 21.5 mg/kg; Trametes 4.3 mg/kg. Following the cessation of leaded petrol use, median total lead concentrations decreased sharply in the 2000s: Cladonia 4.8 mg/kg; Usnea 1.7 mg/kg. The lichen and fungi isotopic compositions reveal a significant decrease in (206)Pb/(207)Pb values from the end of 19th century to the 1970s. The following decades were characterised by lower allowable levels of lead additive in fuel and the introduction of unleaded petrol in 1985. The environmental response to these regulatory changes was that lichen and fungi (206)Pb/(207)Pb values increased, particularly from 1995 onwards. Although the lead isotope ratios of lichens continued to increase in the 2000s they do not return to pre-leaded petrol values. This demonstrates that historic leaded petrol emissions, inter alia other sources, remain a persistent source of anthropogenic contamination in the Greater Sydney region.

  19. Environmental lead exposure among preschool children in Shanghai, China: blood lead levels and risk factors.

    Directory of Open Access Journals (Sweden)

    Jia Cao

    Full Text Available OBJECTIVE: To determine blood lead levels and to identify related risk factors among children in Shanghai; to explore the lead change trend of children after industrial transformation and to provide data for policy development to control environmental lead pollution in Shanghai. METHODS: A stratified-clustered-random sampling method was used. A tungsten atomizer absorption spectrophotometer was employed to determine blood lead levels. RESULTS: The arithmetic mean, geometric mean and median of blood lead levels of 0- to 6-year-old children from Shanghai were 22.49 µg/L, 19.65 µg/L and 19.5 µg/L, including 0.26% (6/2291 with concentrations ≥100 µg/L and 2.7% (61/2291 with concentrations ≥50 µg/L. Boys' levels (23.57 µg/L were greater than those of girls (21.2 µg/L. The blood lead levels increased with age. This survey showed that the Chongming district was the highest and Yangpu district was the lowest, this result is completely opposite with the earlier survey in Shanghai. Risk factors for lead contamination included housing environment, parents' education levels, social status, hobbies, and children's nutritional status. CONCLUSIONS: The blood lead levels of children in Shanghai were lower than the earlier data of Shanghai and those of published studies in China, but higher than the blood lead levels of developed countries. The blood lead levels of urban districts are higher than the central districts with the industrial transformation. Society and the government should take an active interest in childhood lead poisoning of urban areas.

  20. Blood lead levels in children and environmental lead contamination in Miami inner city, Florida.

    Science.gov (United States)

    Gasana, Janvier; Hlaing, WayWay M; Siegel, Kristy A; Chamorro, Armando; Niyonsenga, Theophile

    2006-09-01

    Studies have shown that the environmental conditions of the home are important predictors of health, especially in low-income communities. Understanding the relationship between the environment and health is crucial in the management of certain diseases. One health outcome related to the home environment among urban, minority, and low-income children is childhood lead poisoning. The most common sources of lead exposure for children are lead paint in older, dilapidated housing and contaminated dust and soil produced by accumulated residue of leaded gasoline. Blood lead levels (BLL) as low as 10 microg/dL in children are associated with impaired cognitive function, behavior difficulties, and reduced intelligence. Recently, it is suggested that the standard for intervention be lowered to BLL of 5 microg/dl. The objectives of our report were to assess the prevalence of lead poisoning among children under six years of age and to quantify and test the correlations between BLL in children and lead exposure levels in their environment. This cross-sectional analysis was restricted to 75 children under six years of age who lived in 6 zip code areas of inner city Miami. These locations exhibited unacceptably high levels of lead dust and soil in areas where children live and play. Using the 5 microg/dL as the cutoff point, the prevalence of lead poisoning among the study sample was 13.33%. The study revealed that lead levels in floor dust and window sill samples were positively and significantly correlated with BLL among children (p air, and water samples were not significant. Based on this pilot study, a more comprehensive environmental study in surrounding inner city areas is warranted. Parental education on proper housecleaning techniques may also benefit those living in the high lead-exposed communities of inner city Miami.

  1. Towards modeling gadolinium-lead-borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Rada, S., E-mail: Simona.Rada@phys.utcluj.ro [Department of Physics, Technical University of Cluj-Napoca, 400641 Cluj-Napoca (Romania); Ristoiu, T. [Department of Physics, Technical University of Cluj-Napoca, 400641 Cluj-Napoca (Romania); Rada, M. [Department of Mechatronic, Technical University of Cluj-Napoca, 400641 Cluj-Napoca (Romania); Coroiu, I. [Department of Physics, Technical University of Cluj-Napoca, 400641 Cluj-Napoca (Romania); Maties, V. [Department of Mechatronic, Technical University of Cluj-Napoca, 400641 Cluj-Napoca (Romania); Culea, E. [Department of Physics, Technical University of Cluj-Napoca, 400641 Cluj-Napoca (Romania)

    2010-01-15

    Infrared spectra of gadolinium-lead-borate glasses of the xGd{sub 2}O{sub 3}.(100 - x)[3B{sub 2}O{sub 3}.PbO] system, where x = 0, 5, 10, 15, 25, 35 and 50 mol.%, have been recorded to explore the role of content of gadolinium ions behaving as glass modifier. The FTIR spectroscopy data for the xGd{sub 2}O{sub 3}.(1 - x)[3B{sub 2}O{sub 3}.PbO] glasses show the structural role of lead ions as a network-formers and of the gadolinium ions network modifiers. Adding of the rare earth ion up to 35 mol.% into the glass matrix, the IR bands characteristic to the studied glasses become sharper and more pronounced. Structural changes, as recognized by analyzing band shapes of IR spectra, revealed that Gd{sub 2}O{sub 3} causes a change from the continuous borate network to the continuous lead-borate network interconnected through Pb-O-B and B-O-B bridges and the transformation of some tetrahedral [BO{sub 4}] units into trigonal [BO{sub 3}] units. Then, gadolinium ions have affinity towards [BO{sub 3}] structural units which contain non-bridging oxygens necessary for the charge compensation because the more electronegative [BO{sub 3}] structural units were implied in the formation of B-O-Gd bonds and the transformation of glass network into a glass ceramic. We propose a possible structural model of building blocks for the formation of continuous random 3B{sub 2}O{sub 3}.PbO network glass used by density functional theory (DFT) calculations. DFT calculations show that lead atoms occupy three different sites in the proposed model. The first is coordinated with six oxygen atoms forming distorted octahedral geometries. The second lead atom has an octahedral oxygen environment and the five longer Pb-O bonds are considered as participating in the metal coordination scheme. The third lead atom has ionic character. In agreement with the results offered by the experimental FTIR data, the theoretical IR data confirm that our proposed structure is highly possible.

  2. Children's blood lead levels in the lead smelting town of Port Pirie, South Australia.

    Science.gov (United States)

    Wilson, D; Esterman, A; Lewis, M; Roder, D; Calder, I

    1986-01-01

    This survey included 1,239 children, representing 50% of the elementary school population of the lead smelting town of Port Pirie. Of these children, 7% had a capillary blood lead level equal to or greater than 30 micrograms/dl, which is the Australian National Health and Medical Research Council's "level of concern." There was a statistically significant difference in capillary lead levels by area of residence that was independent of age, sex, soil lead, rainwater tank lead, and school attended. A case-control study indicated that the following subset of factors was most predictive of an elevated blood lead level: household members who worked with lead in their occupations; living in a house with flaking paint on the outside walls; biting finger nails; eating lunch at home on school days; when at school, appearing to have relatively dirty clothing; when at school, appearing to have relatively dirty hands; and living on a household block with a large area of exposed dirt. A program to reduce the risk of elevated blood lead levels in Port Pirie children has been introduced.

  3. Leading Workers to Lead Themselves: The External Leadership of Self-Managing Work Teams.

    Science.gov (United States)

    Manz, Charles C.; Sims, Henry P., Jr.

    1987-01-01

    Explores the paradoxical role of external leaders of self-managing work teams in a medium-sized manufacturing plant. External leaders' most important behaviors are those facilitating the team's management through self-observation, self-evaluation, and self-reinforcement. Leaders' dominant role is to lead others to lead themselves. Contains 6…

  4. Lead and zinc dust depositions from ore trains characterised using lead isotopic compositions.

    Science.gov (United States)

    Kristensen, L J; Taylor, M P; Morrison, A L

    2015-03-01

    This study investigates an unusual source of environmental lead contamination - the emission and deposition of lead and zinc concentrates along train lines into and out of Australia's oldest silver-lead-zinc mine at Broken Hill, Australia. Transport of lead and zinc ore concentrates from the Broken Hill mines has occurred for more than 125 years, during which time the majority was moved in uncovered rail wagons. A significant amount of ore was lost to the adjoining environments, resulting in soil immediately adjacent to train lines elevated with concentrations of lead (695 mg kg(-1)) and zinc (2230 mg kg(-1)). Concentrations of lead and zinc decreased away from the train line and also with depth shown in soil profiles. Lead isotopic compositions demonstrated the soil lead contained Broken Hill ore in increasing percentages closer to the train line, with up to 97% apportioned to the mined Broken Hill ore body. SEM examination showed ceiling dusts collected from houses along the train line were composed of unweathered galena particles, characteristic of the concentrate transported in the rail wagons. The loss of ore from the uncovered wagons has significantly extended the environmental footprint of contamination from local mining operations over an area extending hundreds of kilometres along each of the three train lines.

  5. Lead isotopes in soils near five historic American lead smelters and refineries.

    Science.gov (United States)

    Rabinowitz, Michael B

    2005-06-15

    This survey of soil lead in the vicinity of old industrial sites examines how the stable isotope patterns vary among the sites according to the sources of the lead ore processed at each site. Lead smelters and refineries, which closed down decades ago, are the basis of this investigation. Samples were taken from near five old factory sites in Collinsville and Alton (Illinois), Ponderay (Idaho), East Chicago (Indiana) and Omaha (Nebraska). Historical records were searched for accounts of the sources of the lead. Lead concentrations were measured by atomic absorption flame spectrophotometry, and stable isotopic analysis was done by plasma ionization mass spectrometry. At every site visited, remnants of the old factories, in terms of soil lead pollution, could be found. In spite of potential complications of varying smelter feedstock sourced from mines of different geological age, it was possible to match the isotopic patterns in the soils with the documented sources of the ores. The Collinsville and Alton sites resembled Missouri lead. The Ponderay value was higher than major Bunker Hill, Idaho deposits, but closer to the minor, nearby Oreille County, Washington ores. Mostly Utah ore was used in East Chicago. The Omaha soil reflects lead from Mexico, Colorado and Montana.

  6. Determination of Lead in Human Calculi and Its Effects on Renal Function of Lead Occupational Workers

    Directory of Open Access Journals (Sweden)

    F. Memon

    2016-06-01

    Full Text Available Seventy five samples of renal and eighteen samples of supra gingival calculi of lead recycling workers were collected over the period of seven years (2008-2014 and studied for the accumulation of lead. The results were compared with those of non exposed subjects. The lead content of calculi was investigated for its dependence on type and composition of calculi, blood lead, job status and duration of exposure. The effect of blood lead and renal calculi was also investigated in relation to kidney function of respective subjects. The mean lead levels of various types of calculi were found to follow the order as phosphate > oxalate > urate .> cystine while single principal group of supra gingival calculi resulted in lower levels of metal. The lead content of calculi positively correlated with phosphate content of both of the renal (r = 0.655 and supra gingival calculi (r= 0.866, Impaired renal function was more pronounced in active workers and depended on blood lead levels in addition to presence of metal in renal calculi

  7. Dielectric relaxation losses in lead chloride and lead bromide: Localized dipoles

    NARCIS (Netherlands)

    Brom, W.E. van den; Volger, J.

    1974-01-01

    A further analysis of previous reported measurements of dielectric relaxation losses in lead chloride and lead bromide crystals shows that the dipoles may occupy several energetically different positions, giving rise to localization of the dipoles and anomalous behaviour of the susceptibility. This

  8. Leading logarithms for the nucleon mass

    Directory of Open Access Journals (Sweden)

    Johan Bijnens

    2015-02-01

    Full Text Available Within the heavy baryon chiral perturbation theory approach, we have studied the leading logarithm behavior of the nucleon mass up to four-loop order exactly and we present some results up to six-loop order as well as an all-order conjecture. The same methods allow to calculate the main logarithm multiplying the terms with fractional powers of the quark mass. We calculate thus the coefficients of m2n+1log(n−1⁡(μ2/m2 and m2n+2logn⁡(μ2/m2, with m the lowest-order pion mass. A side result is the leading divergence for a general heavy baryon loop integral.

  9. When municipalities lead co-production

    DEFF Research Database (Denmark)

    Tortzen, Anne

    2015-01-01

    This article explores the role played by municipalities as ‘key leaders’ in co-production processes initiated by local governments. The aim is to produce new insights into the challenges faced by public agencies leading co-production processes in practice. Drawing on an analytical framework deriv...... points to the significant role played by municipalities as hands-off leaders of co-production processes, and identifies leadership dynamics which merit further exploration.......This article explores the role played by municipalities as ‘key leaders’ in co-production processes initiated by local governments. The aim is to produce new insights into the challenges faced by public agencies leading co-production processes in practice. Drawing on an analytical framework derived...

  10. Spectrochemical determination of lead in wines

    Directory of Open Access Journals (Sweden)

    DRAGAN MARKOVIC

    2000-06-01

    Full Text Available The determination of lead in wines of different origin was performed by means of atomic emission spectroscopy with argon stabilized DC. U-shaped arc and electrothermal atomic absorption spectrometry. The comparison of the results obtained by the direct and standard addition method has indicated the presence of a depressive effect of the complex organic matrix. The effect is avoided successfully by mineralization, as well as by dissolution of the samples. Thus, a relative simple but precise and sensitive method involving the application of a stabilized arc and photoelectric detection with time integration of the emission signals is recommended for the determination of low concentrations of lead in wines. The complex organic matrix was investigated by recording the IR spectra of different wine fractions.

  11. III Lead ECG Pulse Measurement Sensor

    Science.gov (United States)

    Thangaraju, S. K.; Munisamy, K.

    2015-09-01

    Heart rate sensing is very important. Method of measuring heart pulse by using an electrocardiogram (ECG) technique is described. Electrocardiogram is a measurement of the potential difference (the electrical pulse) generated by a cardiac tissue, mainly the heart. This paper also reports the development of a three lead ECG hardware system that would be the basis of developing a more cost efficient, portable and easy to use ECG machine. Einthoven's Three Lead method [1] is used for ECG signal extraction. Using amplifiers such as the instrumentation amplifier AD620BN and the conventional operational amplifier Ua741 that would be used to amplify the ECG signal extracted develop this system. The signal would then be filtered from noise using Butterworth filter techniques to obtain optimum output. Also a right leg guard was implemented as a safety feature to this system. Simulation was carried out for development of the system using P-spice Program.

  12. Devastating penile mycosis leading to penile gangrene.

    Science.gov (United States)

    Hombalkar, N N; Vaze, Dhananjay; Guha, Poonam; Dhandore, Priya D; Gurav, Prakash D

    2013-09-01

    Infective penile gangrene is a rare but known complication of circumcision. The causes may vary from neutropenia, diabetes mellitus, and human immunodeficiency virus infection to lymphoproliferative malignancy. Penile mycosis leading to penile gangrene is a rare entity. Only 1 case has been reported in an adult. Juvenile diabetes mellitus is a peculiar predisposing factor for mycotic infections. We report a case of mycotic penile gangrene in a diabetic child to highlight its potentially preventable disastrous outcome.

  13. Healthy Foodservice Benchmarking and Leading Practices

    Science.gov (United States)

    2012-07-01

    reduction in weight status, the prevalence of high waist circumference values, and fasting insulin as compared to the control group. The high- risk portion...whole experienced a slight reduction in weight status (BMI z-score), the prevalence of high waist circumference values, and fasting insulin as... risk for contamination with pesticide residues was 30% lower for organically grown Healthy Foodservice Benchmarking and Leading Practices | 32

  14. Symmetric Wilson Loops beyond leading order

    CERN Document Server

    Chen-Lin, Xinyi

    2016-01-01

    We study the circular Wilson loop in the symmetric representation of U(N) in $\\mathcal{N} = 4$ super-Yang-Mills (SYM). In the large N limit, we computed the exponentially-suppressed corrections for strong coupling, which suggests non-perturbative physics in the dual holographic theory. We also computed the next-to-leading order term in 1/N, and the result matches with the exact result from the k-fundamental representation.

  15. Chronic Heroin Dependence Leading to Adrenal Insufficiency

    Directory of Open Access Journals (Sweden)

    Gautam Das

    2014-01-01

    Full Text Available Opioids have been the mainstay for pain relief and palliation over a long period of time. They are commonly abused by drug addicts and such dependence usually imparts severe physiologic effects on multiple organ systems. The negative impact of opioids on the endocrine system is poorly understood and often underestimated. We describe a patient who developed severe suppression of the hypothalamic-pituitary adrenal (HPA axis leading to secondary adrenal insufficiency due to long standing abuse of opioids.

  16. Electrorheology leads to healthier and tastier chocolate

    OpenAIRE

    Tao, Rongjia; TANG, HONG; Tawhid-Al-Islam, Kazi; Du, Enpeng; Kim, Jeongyoo

    2016-01-01

    Chocolate is one of the most popular food types and flavors in the world. Unfortunately, at present, chocolate products contain too much fat, leading to obesity. Although this issue was called into attention decades ago, no actual solution was found. To bypass this critical outstanding problem, two manufacturers introduced some low-calorie fats to substitute for cocoa butter. Somehow, their fats are forbidden in most countries. Here we show that, by applying an electric field to liquid chocol...

  17. Yili Group: Leading Diary Brand in China

    Institute of Scientific and Technical Information of China (English)

    Xu; Yuxuan; Sun; Yongjian

    2005-01-01

      Inner mongolia Yili Ltd. is one of the leading dairy processing enterprises in China. The company is also one of the top 520 industrial enterprises and the top 151 agricultural enterprises in China. Yili Ltd. has exclusivity as dairy processor in support of the 2008 Beijing Olympic Games. Inner Mongolia Yili Ltd.Sponsorship of the 2008 Olympic Games, heralds it as the first ever Chinese foodbrand to be involved as a sponsor of Olympic Games.……

  18. Yili Group: Leading Diary Brand in China

    Institute of Scientific and Technical Information of China (English)

    Xu Yuxuan; Sun Yongjian

    2005-01-01

    @@ Inner mongolia Yili Ltd. is one of the leading dairy processing enterprises in China. The company is also one of the top 520 industrial enterprises and the top 151 agricultural enterprises in China. Yili Ltd. has exclusivity as dairy processor in support of the 2008 Beijing Olympic Games. Inner Mongolia Yili Ltd.Sponsorship of the 2008 Olympic Games, heralds it as the first ever Chinese foodbrand to be involved as a sponsor of Olympic Games.

  19. Problem Definition Study: Lead Beta-Resorcylate

    Science.gov (United States)

    1979-02-01

    Preteperphyrtn IX (PROTO 9) • Hamt tynthttaw Ft T Mama 7Pb«—e* Iron utilization Fa transferrin (»arum) Into reticulocytes Pb Fb GlObin...in their study of tumor induction by lead acetate. 4. Teratogenicty and Mutagenicity Several studies have been conducted on the teratogenicity of... tumors in experimental animals has been reported by several authors (Van Each et al.t 1962; Van Esch and Kroes, 1969; Waszynski, 1977). In their

  20. Lead in the Japanese living environment

    OpenAIRE

    YOSHINAGA, Jun

    2012-01-01

    Lead has long been known to be a neurotoxic heavy metal, particularly in the context of occupational health. However, its adverse effect on the cognitive development of children at lower exposure levels has only recently received attention. Although the exposure level of contemporary Japanese children is among the lowest in the world, it is desirable to reduce exposure as much as reasonably possible due to the absence of a threshold of exposure for adverse effects. In this review, information...

  1. Leading and managing organizational change initiatives

    OpenAIRE

    Peus, Claudia; Frey, Dieter; Gerkhardt, Marit; Fischer, Peter; Traut-Mattausch, Eva

    2009-01-01

    Although indispensable for long-term economic growth, organizational changes are usually met with resistance. This article draws on psychological theories and empirical evidence to highlight why and under what conditions changes lead to resistance and what likely consequences of resistance are. Furthermore, the article discusses the variables that have been identified as success factors for organizational change initiatives. These include individual difference variables and objective characte...

  2. Leading with integrity: a qualitative research study.

    Science.gov (United States)

    Storr, Loma

    2004-01-01

    This research paper gives an account of a study into the relationship between leadership and integrity. There is a critical analysis of the current literature for effective, successful and ethical leadership particularly, integrity. The purpose and aim of this paper is to build on the current notions of leadership within the literature, debate contemporary approaches, focussing specifically on practices within the UK National Health Service in the early 21st century. This leads to a discussion of the literature on ethical leadership theory, which includes public service values, ethical relationships and leading with integrity. A small study was undertaken consisting of 18 interviews with leaders and managers within a District General HospitaL Using the Repertory Grid technique and analysis 15 themes emerged from the constructs elicited, which were compared to the literature for leadership and integrity and other studies. As well as finding areas of overlap, a number of additional constructs were elicited which suggested that effective leadership correlates with integrity and the presence of integrity will improve organisational effectiveness. The study identified that perceptions of leadership character and behaviour are used to judge the effectiveness and integrity of a leader. However, the ethical implications and consequences of leaders' scope of power and influence such as policy and strategy are somewhat neglected and lacking in debate. The findings suggest that leaders are not judged according to the ethical nature of decision making, and leading and managing complex change but that the importance of integrity and ethical leadership correlated with higher levels of hierarchical status and that it is assumed by virtue of status and success that leaders lead with integrity. Finally, the findings of this study seem to suggest that nurse leadership capability is developing as a consequence of recent national investment.

  3. Gluon saturation beyond (naive) leading logs

    Energy Technology Data Exchange (ETDEWEB)

    Beuf, Guillaume

    2014-12-15

    An improved version of the Balitsky–Kovchegov equation is presented, with a consistent treatment of kinematics. That improvement allows to resum the most severe of the large higher order corrections which plague the conventional versions of high-energy evolution equations, with approximate kinematics. This result represents a further step towards having high-energy QCD scattering processes under control beyond strict Leading Logarithmic accuracy and with gluon saturation effects.

  4. Lead-Time Reductions in SME s

    Institute of Scientific and Technical Information of China (English)

    D; Ashall; B; Parkinson

    2002-01-01

    Background: Over recent years many manufacturing or ga nisations have focussed their attention on improving operational effectiveness. Whilst improvements made have increased the level of manufacturing efficiency in many cases these have not been reflected within SME's by their response in me eting customer lead times. Aims: Whilst considerable efficiency gains have been made in the manufacturing e nvironment the improvements achieved have not necessarily been reflected in the attainment of customer d...

  5. Strand misalignments lead to quasipalindrome correction

    DEFF Research Database (Denmark)

    van Noort, V.; Worning, Peder; Ussery, David

    2003-01-01

    Quasipalindromes, or imperfect inverted repeats, undergo spontaneous mutation to more-perfect inverted repeats. These mutations have been observed in many organisms, ranging from bacteria to humans, where they are associated with mutations leading to disease. We determined the relative frequency...... of quasi palindromes and perfect palindromes in more than 100 sequenced prokaryotic genomes. In nearly all cases, perfect palindromes were relatively more frequent than quasipalindromes, suggesting that quasipalindrome correction is a general mechanism for mutation in prokaryotes....

  6. Low level exposures to lead and neurobehavioral development: the Sydney lead study

    Energy Technology Data Exchange (ETDEWEB)

    Cooney, G.H.; Bell, A.; McBride, W.; Carter, C.

    1988-01-01

    The Sydney lead study is a prospective five year study investigating the relationship between low level lead exposures and neurobehavioral development during the first five years of life. From an initial cohort of 318 children, 207 remained at the end of the fourth year. Average blood lead levels at 42 and 48 months were 10.6 ug/dL and 10.1 ug/dL respectively, with only a minority of the observations exceeding 15 ug/dL. The series of regression analyses reported in this paper support earlier findings from the study, that exposures to lead which give rise to the range of blood lead levels found in this cohort of children are not associated with cognitive or motor deficits in the preschool years.

  7. Influences and trends in lead/acid battery demand, lead supply and prices

    Science.gov (United States)

    Hawkes, N.

    This study examines: (i) the historical trends and influences in Western World lead demand, paying particular attention to the battery sector; (ii) the historical trends in Western World lead production in both the primary and secondary sectors, highlighting key influences; (iii) the long-term relationship between consumption and both primary and secondary lead production, and (iv) the lead price and stock history, before summarizing the current situation in the lead market. Finally suggestions are given for a few points to watch for in the future. Most of the paper refers separately to 'Western World' and 'Eastern Bloc' countries. The definition of Western World includes all countries except the following: PR China, all CIS republics (the former USSR), Mongolia, North Korea, Cuba, Cambodia, Laos, Vietnam, and the Eastern European countries of Poland, Bulgaria, Romania, Czech and Slovak Republics, Hungary and Albania. These countries are collectively referred to as 'Eastern Bloc'.

  8. Impacts of converting from leaded to unleaded gasoline on ambient lead concentrations in Jakarta metropolitan area

    Institute of Scientific and Technical Information of China (English)

    Akira KONDO; Esrom HAMONANGAN; Satoshi SODA; Akikazu KAGA; Yoshio INOUE; Masaharu EGUCHI; Yuta YASAKA

    2007-01-01

    Total suspended particulate mater (TSP) concentrations were monitored for one year from July 2000 and for one year from April 2003 in Jakarta City. Thirteen elemental TSP components, aluminum (Al), sodium (Na), iron (Fe), lead (Pb), potassium (K), zinc (Zn), titanium (Ti), manganese (Mn), bromine (Br), copper (Cu), chromium (Cr), nickel (Ni), and vanadium (Ⅴ) were analyzed by a sequential X-ray fluorescence spectrometer. Al, Na, Fe, K, and Pb were major components at most of the sampling locations in 2000. However, only Pb in 2003 dramatically decreased to one tenth. The phase-out of leaded gasoline began on July 1, 2001 in Jakarta City and lead content in gasoline decreased to one tenth, too. The decrease in Pb concentration was a result of the phase-out of leaded gasoline, as lead emissions mainly are exhaust gas from vehicles.

  9. Impacts of converting from leaded to unleaded gasoline on ambient lead concentrations in Jakarta metropolitan area.

    Science.gov (United States)

    Kondo, Akira; Hamonangan, Esrom; Soda, Satoshi; Kaga, Akikazu; Inoue, Yoshio; Eguchi, Masaharu; Yasaka, Yuta

    2007-01-01

    Total suspended particulate mater (TSP) concentrations were monitored for one year from July 2000 and for one year from April 2003 in Jakarta City. Thirteen elemental TSP components, aluminum (Al), sodium (Na), iron (Fe), lead (Pb), potassium (K), zinc (Zn), titanium (Ti), manganese (Mn), bromine (Br), copper (Cu), chromium (Cr), nickel (Ni), and vanadium (V) were analyzed by a sequential X-ray fluorescence spectrometer. Al, Na, Fe, K, and Pb were major components at most of the sampling locations in 2000. However, only Pb in 2003 dramatically decreased to one tenth. The phase-out of leaded gasoline began on July 1, 2001 in Jakarta City and lead content in gasoline decreased to one tenth, too. The decrease in Pb concentration was a result of the phase-out of leaded gasoline, as lead emissions mainly are exhaust gas from vehicles.

  10. Lead tolerance in plants: strategies for phytoremediation.

    Science.gov (United States)

    Gupta, D K; Huang, H G; Corpas, F J

    2013-04-01

    Lead (Pb) is naturally occurring element whose distribution in the environment occurs because of its extensive use in paints, petrol, explosives, sludge, and industrial wastes. In plants, Pb uptake and translocation occurs, causing toxic effects resulting in decrease of biomass production. Commonly plants may prevent the toxic effect of heavy metals by induction of various celular mechanisms such as adsorption to the cell wall, compartmentation in vacuoles, enhancement of the active efflux, or induction of higher levels of metal chelates like a protein complex (metallothioneins and phytochelatins), organic (citrates), and inorganic (sulphides) complexes. Phyotochelains (PC) are synthesized from glutathione (GSH) and such synthesis is due to transpeptidation of γ-glutamyl cysteinyl dipeptides from GSH by the action of a constitutively present enzyme, PC synthase. Phytochelatin binds to Pb ions leading to sequestration of Pb ions in plants and thus serves as an important component of the detoxification mechanism in plants. At cellular level, Pb induces accumulation of reactive oxygen species (ROS), as a result of imbalanced ROS production and ROS scavenging processes by imposing oxidative stress. ROS include superoxide radical (O2(.-)), hydrogen peroxide (H2O2) and hydroxyl radical ((·)OH), which are necessary for the correct functioning of plants; however, in excess they caused damage to biomolecules, such as membrane lipids, proteins, and nucleic acids among others. To limit the detrimental impact of Pb, efficient strategies like phytoremediation are required. In this review, it will discuss recent advancement and potential application of plants for lead removal from the environment.

  11. Iodide-assisted total lead measurement and determination of different lead fractions in drinking water samples.

    Science.gov (United States)

    Zhang, Yuanyuan; Ng, Ding-Quan; Lin, Yi-Pin

    2012-07-01

    Lead and its compounds are toxic and can harm human health, especially the intelligence development in children. Accurate measurement of total lead present in drinking water is crucial in determining the extent of lead contamination and human exposure due to drinking water consumption. The USEPA method for total lead measurement (no. 200.8) is often used to analyze lead levels in drinking water. However, in the presence of high concentration of the tetravalent lead corrosion product PbO(2), the USEPA method was not able to fully recover particulate lead due to incomplete dissolution of PbO(2) particles during strong acid digestion. In this study, a new procedure that integrates membrane separation, iodometric PbO(2) measurement, strong acid digestion and ICP-MS measurement was proposed and evaluated for accurate total lead measurement and quantification of different lead fractions including soluble Pb(2+), particulate Pb(II) carbonate and PbO(2) in drinking water samples. The proposed procedure was evaluated using drinking water reconstituted with spiked Pb(2+), spiked particulate Pb(II) carbonate and in situ formed or spiked PbO(2). Recovery tests showed that the proposed procedure and the USEPA method can achieve 93-112% and 86-103% recoveries respectively for samples containing low PbO(2) concentrations (0.018-0.076 mg Pb per L). For samples containing higher concentrations of PbO(2) (0.089-1.316 mg Pb per L), the USEPA method failed to meet the recovery requirement for total lead (85-115%) while the proposed method can achieve satisfactory recoveries (91-111%) and differentiate the soluble Pb(2+), particulate Pb(II) carbonate and PbO(2).

  12. Ancient Greek lead findings in Ukraine

    Energy Technology Data Exchange (ETDEWEB)

    Danevich, F.A. [Institute for Nuclear Research, MSP 03680 Kyiv (Ukraine)], E-mail: danevich@kinr.kiev.ua; Kim, S.K. [DMRC and School of Physics, Seoul National University, Seoul 151-742 (Korea, Republic of); Kim, H.J. [Physics Department, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Kim, Y.D. [Sejong University, Seoul 143-747 (Korea, Republic of); Kobychev, V.V. [Institute for Nuclear Research, MSP 03680 Kyiv (Ukraine); Kostezh, A.B. [Institute for Hydrometeorology Research, MSP 03650 Kyiv (Ukraine); Kropivyansky, B.N. [Institute for Nuclear Research, MSP 03680 Kyiv (Ukraine); Laubenstein, M. [Laboratori Nazionali del Gran Sasso, I-67010 Assergi (AQ) (Italy); Mokina, V.M.; Nagorny, S.S.; Nikolaiko, A.S. [Institute for Nuclear Research, MSP 03680 Kyiv (Ukraine); Nisi, S. [Laboratori Nazionali del Gran Sasso, I-67010 Assergi (Italy); Poda, D.V.; Tretyak, V.I. [Institute for Nuclear Research, MSP 03680 Kyiv (Ukraine); Voronov, S.A. [Department of Underwater Heritage, Institute of Archaeology, 04210 Kyiv (Ukraine)

    2009-05-21

    In June-August 2006 an expedition with the aim to look for archaeological lead with low levels of {sup 210}Pb was organised by a Korean-Ukrainian collaboration on the shelf of the Black Sea, near the Crimean Peninsula. The first samples with {approx}0.2 ton of total mass were found at a depth of 28 m among the relics of an ancient Greek ship. Their age has been dated to the first century BC. The element composition of the samples was measured by means of X-ray fluorescence and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) analyses. The radiopurity of the lead was tested using low-level and ultra-low-level {gamma}-spectrometry at a surface laboratory in Kyiv, at the Solotvina Underground Laboratory (Ukraine), and deep underground at the Laboratori Nazionali del Gran Sasso (LNGS, Italy). The samples have been assessed at the LNGS also by means of {alpha}-spectroscopy. For all investigated radionuclides, only upper limits could be obtained. Limits on activities of radionuclides in the lead after melting were set at the level of <(0.2-0.3) mBq kg{sup -1} ({sup 60}Co), <(0.2-0.7) mBq kg{sup -1} ({sup 137}Cs), <(0.2-0.9) mBq kg{sup -1} ({sup 226}Ra), <(0.1-0.9) mBq kg{sup -1} ({sup 228}Th), <(5-7) mBq kg{sup -1} ({sup 40}K), <(0.3-1.4) Bq kg{sup -1} ({sup 210}Po), and <(12-13) Bq kg{sup -1} ({sup 210}Pb). Any {sup 210}Pb present in the lead after it was produced ca. 2000 years ago has decayed away. Assuming secular equilibrium in the {sup 238}U chain in the lead, the activity of {sup 210}Pb due to {sup 238}U can be restricted to <(5-17) mBq kg{sup -1} before melting, and <(0.2-0.9) mBq kg{sup -1} after melting.

  13. Modified natural clinoptilolite detoxifies small mammal's organism loaded with lead I. Lead disposition and kinetic model for lead bioaccumulation.

    Science.gov (United States)

    Beltcheva, Michaela; Metcheva, Roumiana; Popov, Nikolay; Teodorova, Svetla E; Heredia-Rojas, J Antonio; Rodríguez-de la Fuente, Abraham O; Rodríguez-Flores, Laura E; Topashka-Ancheva, Margarita

    2012-06-01

    Zeolites, especially clinoptilolites, have wide application in removing heavy metals from different solutions and wastewater. The detoxification capacity of the clinoptilolite sorbent KLS-10-MA, a modified natural Bulgarian zeolite, applied as a food supplement in conditions of an ecotoxicological experiment with conventional food and lead was demonstrated for the first time. Laboratory mice, inbred imprinting control region strain, were used in a 90-day ecotoxicological experiment. Animals were divided into four experimental groups. Lead bioaccumulations in exposed and non-supplemented/supplemented with KLS-10-MA animals were compared. As additional control, healthy animals non-exposed to Pb were fed with conventional forage mixed with 12.5% KLS-10-MA. The dietary inclusion of the sorbent reduced Pb concentrations in exposed and supplemented mice by 84%, 89%, 91%, 77%, and 88% in carcass, liver, kidneys, bones, and feces, respectively. A mathematical model was proposed to outline the common trends of bone Pb bioaccumulation in exposed and non-supplemented/supplemented animals. Characteristic parameters of the kinetics of Pb concentrations were determined. Based on the model, the coefficient of absorption of Pb by gastrointestinal mucosa in the supplemented mice was found-η = 3.53% (versus η = 15% in non-supplemented ones). The present study clearly indicates that there is a realistic perspective to create a new drug based on modified natural clinoptilolites in cases of chronic heavy metal intoxication, without negatively affecting the environment.

  14. The leaching of lead from lead-based paint in landfill environments.

    Science.gov (United States)

    Wadanambi, Lakmini; Dubey, Brajesh; Townsend, Timothy

    2008-08-30

    Lead leaching from lead-based paint (LBP) was examined using standardized laboratory protocols and tests with leachate from actual and simulated landfill environments. Two different LBP samples were tested; leaching solutions included leachates from three municipal solid waste (MSW) landfills and three construction and demolition (C&D) debris landfills. The toxicity characteristic leaching procedure (TCLP) and the synthetic precipitation leaching procedure (SPLP) were also performed. Lead concentrations were many times higher using the TCLP compared to the SPLP and the landfill leachates. No significant difference (alpha=0.05) was observed in leached lead concentrations from the MSW landfill and C&D debris landfill leachates. The impact of other building materials present in LBP debris on lead leaching was examined by testing mixtures of LBP (2%) and different building materials (98%; steel, wood, drywall, concrete). The type of substrate present impacted lead leaching results, with concrete demonstrating the most dramatic impact; the lowest lead concentrations were measured in the presence of concrete under both TCLP and SPLP extractions.

  15. Cellular and molecular toxicology of lead. I. Effect of lead on cultured cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Kusell, M.; O' Cheskey, S.; Gerschenson, L.E.

    1978-01-01

    Growth studies were done on a cultured rat liver cell line (RLC-GAI) grown in a chemically defined medium in the presence of lead nitrate. Lead reversibly inhibited the growth of these cells even after 6 d of exposure to the heavy metal. To compare lead sensitivity in various cell lines, GI50 and LD50 values were determined in the RLC-GAI cells as well as two glioma cell lines (B82 and C/sub 6/) and a neuroblastoma cell line (N18). The LD50 values paralleled but were consistently lower than the GI50 values. Since lead is known to affect heme synthesis, hemin was added to test the possibility of preventing the growth-inhibitory effect of the lead. The growth capacity of lead-treated cells did not change with the addition of hemin. It is thought that differentiated cultured cell lines such as these could be useful in examining the molecular mechanism of lead toxicity.

  16. Lead contamination in the homes of employees of secondary lead smelters

    Energy Technology Data Exchange (ETDEWEB)

    Rice, C.; Fischbein, A.; Lilis, R.; Sarkozi, L.; Kon, S.; Selikoff, I.J.

    1978-06-01

    The lead content of particulates in 33 homes of employees of two secondary lead smelters in different geographical areas of the country was investigated. Employees generally showered before going home and work clothes were laundered by the companies. Despite these hygiene measures, the lead content of particulates in the workers' homes was found to be significantly greater than in samples collected in control homes in the same or similar neighborhoods. Samples were collected by the Vostal method. In one area, a geometric mean of 79.3 ..mu..g of lead/towel was found in the workers' homes, compared with 28.8 ..mu..g/towel in the homes of workers with no history of lead exposure. In the second area studied, a geometric mean of 112.0 ..mu..g was determined in the workers' homes, compared with 9.7 ..mu..g in the homes of controls. In the latter area, paint chips, particulates from the sidewalk curb, and settled dust were also collected and analyzed for lead content. Elevated zinc protoporphyrin levels were found in some children of lead-exposed workers, but not among children in control homes.

  17. Experimental study of blood lead kinetics in estuarine crocodiles (Crocodylus porosus) exposed to ingested lead shot.

    Science.gov (United States)

    Hammerton, K M; Jayasinghe, N; Jeffree, R A; Lim, R P

    2003-10-01

    A previous study of lead (Pb) contamination in estuarine crocodiles (Crocodylus porosus) in Kakadu National Park, Australia, found elevated Pb levels in bone and flesh from individuals caught in habitats where hunting with lead ammunition had occurred. Lead shot was suspected as the potential source of Pb in these animals. An investigation was designed to determine if crocodiles are capable of retaining and dissolving lead shot in their stomachs and absorbing the ionic Pb into the blood. Four of the six juvenile crocodiles (C. porosus) used in the experiment were fed an initial dose of five or ten lead shot each. Most of the lead shot were retained in the stomach over the 20-week experimental period, as confirmed by stomach lavage and radiography of the stomach region. From 13 to 30% of the original weight of individual lead shot had been eroded in that time. In vitro experiments confirmed that lead shot could be dissolved under conditions simulating those known for the crocodilian stomach. Blood Pb concentrations increased by an order of magnitude within a week after dosing three crocodiles with five lead shot each, and then attained steady-state equilibrium 5-20 weeks after dosing, with blood Pb steady-state levels ranging from 278 to 363 microg/dL. The blood Pb concentration-time curves in these crocodiles followed a one-compartment model with first-order loss kinetics that yielded an apparent biological half-life for Pb in blood of about 3.4 days. Throughout the experiment, the crocodiles remained in apparent good physical condition and displayed no clinical signs of Pb toxicosis. These observations, together with the very high blood Pb levels that were sustained for several months, suggest that crocodilians may possess a relatively high degree of resistance to Pb toxicity.

  18. XRD, lead equivalent and UV-VIS properties study of Ce and Pr lead silicate glasses

    Science.gov (United States)

    Alias, Nor Hayati; Abdullah, Wan Shafie Wan; Isa, Norriza Mohd; Isa, Muhammad Jamal Md; Muhammad, Azali; Zali, Nurazila Mat; Abdullah, Nuhaslinda Ee

    2014-02-01

    In this work, Cerium (Ce) and Praseodymium (Pr) containing lead silicate glasses were produced with 2 different molar ratios low (0.2 wt%) and high (0.4wt%). These types of glasses can satisfy the characteristics required for radiation shielding glasses and minimize the lead composition in glass. The radiation shielding properties of the synthesized glasses is explained in the form of lead equivalent study. The XRD diffraction and UV-VIS analysis were performed to observe the structural changes of the synthesis glasses at 1.5 Gy gamma radiation exposures.

  19. Failure modes of lead/acid batteries

    Science.gov (United States)

    Culpin, B.; Rand, D. A. J.

    The delivery and storage of electrical energy in lead/acid batteries via the conversion of lead dioxide and lead to, and from, lead sulphate is deceptively simple. In fact, battery performance depends upon the cell design, the materials of construction, a complex interplay between the multitudinous parameters involved in plate preparation, the chemical composition/structure of the active materials, and the duty/conditions of battery operation. It is not surprising, therefore, that the factors responsible for the degradation of battery performance, and eventual failure, are many and varied. Apart from occasional field surveys of automotive batteries in the U.S.A., comprehensive failure analyses of units removed from service are rarely published. In general, the information is kept proprietary, or appears as a post mortem report that is subsidiary to some other topic of interest. By contrast, the literature abounds with detailed laboratory investigations of phenomena that are likely to contribute, wholly or in part, to the demise of batteries. In broad terms, this review draws together the fragmented and scattered data presently available on the failure mechanisms of lead/acid batteries in order to provide a platform for further exploration of the phenomena, and for the planning of remedial strategies. The approach taken is to classify, first, the different lead/acid technologies in terms of required duty (i.e., float, cycling and automotive applications), unit design (i.e., flat or tubular plate, flooded or immobilized electrolyte), and grid alloy (i.e., leadantimony or leadcalcium system). A distinction is then made between catastrophic failure, as characterized by a sudden inability of the battery to function, and progressive failure, as demonstrated by some more subtle deviation from optimum performance. Catastrophic failure is attributed to incorrect cell design, poor manufacturing practice, abuse, or misuse. These problems are obvious and, accordingly

  20. Making and Breaking of Lead Halide Perovskites.

    Science.gov (United States)

    Manser, Joseph S; Saidaminov, Makhsud I; Christians, Jeffrey A; Bakr, Osman M; Kamat, Prashant V

    2016-02-16

    A new front-runner has emerged in the field of next-generation photovoltaics. A unique class of materials, known as organic metal halide perovskites, bridges the gap between low-cost fabrication and exceptional device performance. These compounds can be processed at low temperature (typically in the range 80-150 °C) and readily self-assemble from the solution phase into high-quality semiconductor thin films. The low energetic barrier for crystal formation has mixed consequences. On one hand, it enables inexpensive processing and both optical and electronic tunability. The caveat, however, is that many as-formed lead halide perovskite thin films lack chemical and structural stability, undergoing rapid degradation in the presence of moisture or heat. To date, improvements in perovskite solar cell efficiency have resulted primarily from better control over thin film morphology, manipulation of the stoichiometry and chemistry of lead halide and alkylammonium halide precursors, and the choice of solvent treatment. Proper characterization and tuning of processing parameters can aid in rational optimization of perovskite devices. Likewise, gaining a comprehensive understanding of the degradation mechanism and identifying components of the perovskite structure that may be particularly susceptible to attack by moisture are vital to mitigate device degradation under operating conditions. This Account provides insight into the lifecycle of organic-inorganic lead halide perovskites, including (i) the nature of the precursor solution, (ii) formation of solid-state perovskite thin films and single crystals, and (iii) transformation of perovskites into hydrated phases upon exposure to moisture. In particular, spectroscopic and structural characterization techniques shed light on the thermally driven evolution of the perovskite structure. By tuning precursor stoichiometry and chemistry, and thus the lead halide charge-transfer complexes present in solution, crystallization

  1. Making and Breaking of Lead Halide Perovskites

    KAUST Repository

    Manser, Joseph S.

    2016-02-16

    A new front-runner has emerged in the field of next-generation photovoltaics. A unique class of materials, known as organic metal halide perovskites, bridges the gap between low-cost fabrication and exceptional device performance. These compounds can be processed at low temperature (typically in the range 80–150 °C) and readily self-assemble from the solution phase into high-quality semiconductor thin films. The low energetic barrier for crystal formation has mixed consequences. On one hand, it enables inexpensive processing and both optical and electronic tunability. The caveat, however, is that many as-formed lead halide perovskite thin films lack chemical and structural stability, undergoing rapid degradation in the presence of moisture or heat. To date, improvements in perovskite solar cell efficiency have resulted primarily from better control over thin film morphology, manipulation of the stoichiometry and chemistry of lead halide and alkylammonium halide precursors, and the choice of solvent treatment. Proper characterization and tuning of processing parameters can aid in rational optimization of perovskite devices. Likewise, gaining a comprehensive understanding of the degradation mechanism and identifying components of the perovskite structure that may be particularly susceptible to attack by moisture are vital to mitigate device degradation under operating conditions. This Account provides insight into the lifecycle of organic–inorganic lead halide perovskites, including (i) the nature of the precursor solution, (ii) formation of solid-state perovskite thin films and single crystals, and (iii) transformation of perovskites into hydrated phases upon exposure to moisture. In particular, spectroscopic and structural characterization techniques shed light on the thermally driven evolution of the perovskite structure. By tuning precursor stoichiometry and chemistry, and thus the lead halide charge-transfer complexes present in solution, crystallization

  2. Available: lead plate from COMPASS experiment

    CERN Multimedia

    The COMPASS collaboration

    2014-01-01

    The COMPASS collaboration would like to offer the possibility to take over a large and thick lead plate, since it is not required anymore in the spectrometer.   It has the following dimensions: thickness 100 mm, width 4.4 m and height 2.0 m, with a square hole in the middle with dimensions of 40 cm x 40 cm. The measured weight including the metal frame it is housed in is 10,180 kg. The CERN stores reference is 44.13.30.100.9. Please contact Erwin Bielert (erwin.bielert@cern.ch or 160539) for further information and details.

  3. Leading order QCD in Coulomb gauge

    CERN Document Server

    Watson, Peter

    2011-01-01

    Coulomb gauge QCD in the first order formalism can be written in terms of a ghost-free, nonlocal action that ensures total color charge conservation via Gauss' law. Making an Ansatz whereby the nonlocal term (the Coulomb kernel) is replaced by its expectation value, the resulting Dyson-Schwinger equations can be derived. With a leading order truncation, these equations reduce to the gap equations for the static gluon and quark propagators obtained from a quasi-particle approximation to the canonical Hamiltonian approach. Moreover a connection to the heavy quark limit can be established, allowing an intuitive explanation for the charge constraint and infrared divergences.

  4. Research Update: Luminescence in lead halide perovskites

    Science.gov (United States)

    Srimath Kandada, Ajay Ram; Petrozza, Annamaria

    2016-09-01

    Efficiency and dynamics of radiative recombination of carriers are crucial figures of merit for optoelectronic materials. Following the recent success of lead halide perovskites in efficient photovoltaic and light emitting technologies, here we review some of the noted literature on the luminescence of this emerging class of materials. After outlining the theoretical formalism that is currently used to explain the carrier recombination dynamics, we review a few significant works which use photoluminescence as a tool to understand and optimize the operation of perovskite based optoelectronic devices.

  5. Adsorption of lead over graphite oxide.

    Science.gov (United States)

    Olanipekun, Opeyemi; Oyefusi, Adebola; Neelgund, Gururaj M; Oki, Aderemi

    2014-01-24

    The adsorption efficiency and kinetics of removal of lead in presence of graphite oxide (GO) was determined using the Atomic Absorption Spectrophotometer (AAS). The GO was prepared by the chemical oxidation of graphite and characterized using FTIR, SEM, TGA and XRD. The adsorption efficiency of GO for the solution containing 50, 100 and 150 ppm of Pb(2+) was found to be 98%, 91% and 71% respectively. The adsorption ability of GO was found to be higher than graphite. Therefore, the oxidation of activated carbon in removal of heavy metals may be a viable option to reduce pollution in portable water.

  6. Transcriptional networks leading to symbiotic nodule organogenesis.

    Science.gov (United States)

    Soyano, Takashi; Hayashi, Makoto

    2014-08-01

    The symbiosis with nitrogen-fixing bacteria leading to root nodules is a relatively recent evolutionary innovation and limited to a distinct order of land plants. It has long been a mystery how plants have invented this complex trait. However, recent advances in molecular genetics of model legumes has elucidated genes involved in the development of root nodules, providing insights into this process. Here we discuss how the de novo assembly of transcriptional networks may account for the predisposition to nodulate. Transcriptional networks and modes of gene regulation from the arbuscular mycorrhizal symbiosis, nitrate responses and aspects of lateral root development have likely all contributed to the emergence and development of root nodules.

  7. Electronic and optical properties of lead iodide

    DEFF Research Database (Denmark)

    Ahuja, R.; Arwin, H.; Ferreira da Silva, A.

    2002-01-01

    The electronic properties and the optical absorption of lead iodide (PbI2) have been investigated experimentally by means of optical absorption and spectroscopic ellipsometry, and theoretically by a full-potential linear muffin-tin-orbital method. PbI2 has been recognized as a very promising...... detector material with a large technological applicability. Its band-gap energy as a function of temperature has also been measured by optical absorption. The temperature dependence has been fitted by two different relations, and a discussion of these fittings is given. ©2002 American Institute of Physics....

  8. Lead Slowing Down Spectrometer Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Glen A.; Anderson, Kevin K.; Bonebrake, Eric; Casella, Andrew M.; Danon, Yaron; Devlin, M.; Gavron, Victor A.; Haight, R. C.; Imel, G. R.; Kulisek, Jonathan A.; O' Donnell, J. M.; Weltz, Adam

    2012-06-07

    This report documents the progress that has been completed in the first half of FY2012 in the MPACT-funded Lead Slowing Down Spectrometer project. Significant progress has been made on the algorithm development. We have an improve understanding of the experimental responses in LSDS for fuel-related material. The calibration of the ultra-depleted uranium foils was completed, but the results are inconsistent from measurement to measurement. Future work includes developing a conceptual model of an LSDS system to assay plutonium in used fuel, improving agreement between simulations and measurement, design of a thorium fission chamber, and evaluation of additional detector techniques.

  9. Research Update: Luminescence in lead halide perovskites

    Directory of Open Access Journals (Sweden)

    Ajay Ram Srimath Kandada

    2016-09-01

    Full Text Available Efficiency and dynamics of radiative recombination of carriers are crucial figures of merit for optoelectronic materials. Following the recent success of lead halide perovskites in efficient photovoltaic and light emitting technologies, here we review some of the noted literature on the luminescence of this emerging class of materials. After outlining the theoretical formalism that is currently used to explain the carrier recombination dynamics, we review a few significant works which use photoluminescence as a tool to understand and optimize the operation of perovskite based optoelectronic devices.

  10. China Leading in Clean Energy Spending

    Institute of Scientific and Technical Information of China (English)

    Wu Zhenjun

    2010-01-01

    @@ China has taken the lead in investments in clean energy,spending nearly double what the US did in 2009,as it ramps up projects in both renewable and traditional energy.China's investment and financing for clean energy rose to US$34.6 billion in 2009,out of US$162 billion invested globally,according to the report by the nonprofit Pew Charitable Trusts.US spending ranked second,at US$18.6 billion,with European nations also recording strong growth.

  11. LEADING EFFECTIVE MEETINGS IN A HOSPITALITY ORGANIZATION

    Directory of Open Access Journals (Sweden)

    Slobodan Ivanovic

    2010-06-01

    Full Text Available Today’s business environment demands of the individual manager to lead effective meetings. This is a skill which has to be studied and to be used and constantly optimized in order to keep the team focused on the goals that were set. Meetings keep track of a teams and the organizations goals that are being met or not being met. The specific focus of a certain meeting depends on what on what is to be achieved, whether that be setting goals or keeping evidence of what is being done, and to do this one needs the proper information tolead it correctly and efficiently.

  12. Structural evolution and metallicity of lead clusters

    Science.gov (United States)

    Götz, Daniel A.; Shayeghi, Armin; Johnston, Roy L.; Schwerdtfeger, Peter; Schäfer, Rolf

    2016-05-01

    The evolution of the metallic state in lead clusters and its structural implications are subject to ongoing discussions. Here we present molecular beam electric deflection studies of neutral PbN (N = 19-25, 31, 36, 54) clusters. Many of them exhibit dipole moments or anomalies of the polarizability indicating a non-metallic state. In order to resolve their structures, the configurational space is searched using the Pool Birmingham Cluster Genetic algorithm based on density functional theory. Spin-orbit effects on the geometries and dipole moments are taken into account by further relaxing them with two-component density functional theory. Geometries and dielectric properties from quantum chemical calculations are then used to simulate beam deflection profiles. Structures are assigned by the comparison of measured and simulated beam profiles. Energy gaps are calculated using time-dependent density functional theory. They are compared to Kubo gaps, which are an indicator of the metallicity in finite particles. Both, experimental and theoretical data suggest that lead clusters are not metallic up to at least 36 atoms.The evolution of the metallic state in lead clusters and its structural implications are subject to ongoing discussions. Here we present molecular beam electric deflection studies of neutral PbN (N = 19-25, 31, 36, 54) clusters. Many of them exhibit dipole moments or anomalies of the polarizability indicating a non-metallic state. In order to resolve their structures, the configurational space is searched using the Pool Birmingham Cluster Genetic algorithm based on density functional theory. Spin-orbit effects on the geometries and dipole moments are taken into account by further relaxing them with two-component density functional theory. Geometries and dielectric properties from quantum chemical calculations are then used to simulate beam deflection profiles. Structures are assigned by the comparison of measured and simulated beam profiles. Energy gaps

  13. Who Gets to Lead the Multinational Team?

    DEFF Research Database (Denmark)

    Paunova, Minna

    2016-01-01

    This article examines the emergence of informal leadership in multinational teams. Building on and extending status characteristics theory, the article proposes and tests a model that describes how global inequalities reproduce in multinational teams, and accounts for who gets to lead these teams...... of their core self-evaluations. A study of over 230 individuals from 46 nationalities working in 36 self-managing teams generally supports the expected main and moderation effects. Individual core self-evaluations enhance an otherwise weak effect of English proficiency, but compensate for low levels of national...

  14. Does Education Lead to Higher Generalized Trust?

    DEFF Research Database (Denmark)

    Charron, Nicholas; Rothstein, Bo

    2016-01-01

    Generalized trust has become a prominent concept at the nexus of several disciplines, and the wide differences in trust between different societies continue to puzzle the social sciences. In this study, we explore the effects of micro and macro level factors in explaining an individual's propensity...... to ‘trust others'. We hypothesize that higher levels of education will lead to higher social trust in individuals, given that the context (country or regions within countries) in which they reside has a sufficiently impartial and non-corrupt institutional setting. However, the positive effect of education...

  15. Lead user identification in online communities

    DEFF Research Database (Denmark)

    Ormrod, Robert P.; Søndergaard, Helle Alsted

    Presents results of an exploratory study into the online identification of Lead Users (LU). Integrates three approaches to identifying LU and specifically aims to provide managers with a straightforward method of detecting this group. Four theoretically-derived clusters are investigated, based...... experience with developing web-based media. Results: four-cluster conceptualisation is generally supported; no significant difference between clusters concerning contribution to chat/fora; significantly more LU than by chance who contribute to a specific feedback forum and who have experience...

  16. Leading a Recovery-oriented Social Enterprise.

    Science.gov (United States)

    Raeburn, Toby; Hungerford, Catherine; Sayers, Jan; Escott, Phil; Lopez, Violeta; Cleary, Michelle

    2015-05-01

    Recovery-oriented mental health services promote the principles of recovery, such as hope and optimism, and are characterized by a personalized approach to developing consumer self-determination. Nurse leaders are increasingly developing such services as social enterprises, but there is limited research on the leadership of these programs. Leading a recovery-oriented mental health nurse social enterprise requires visionary leadership, collaboration with consumers and local health providers, financial viability, and commitment to recovery-focused practice. This article describes the framework of an Australian mental health nursing social enterprise, including the service attributes and leadership lessons that have been learned from developing program sustainability.

  17. Lead in water sources and lead and organochlorines in supplemental food items for the California condor

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — All but one water sample had lead concentrations below the detection limit (Table 1). The water sample collected from Ventucopa, located in Santa Barbara County, had...

  18. Nanostructured Lead Compounds in Electrode Materials of a Lead-Acid Battery

    Directory of Open Access Journals (Sweden)

    A.P. Kuzmenko

    2016-11-01

    Full Text Available The nanostructure and phase composition of the electrode material of lead-acid batteries, formed by chemical transformations with involvement of sulfuric acid solutions of various concentrations, water and carbon dioxide have been studied.

  19. Compatibility tests on steels in molten lead and lead-bismuth

    Energy Technology Data Exchange (ETDEWEB)

    Fazio, C. E-mail: concetta@netbra.brasimone.enea.it; Benamati, G.; Martini, C.; Palombarini, G

    2001-07-01

    The compatibility of steels with liquid lead and liquid lead-bismuth is a critical issue for the development of accelerator-driven system (ADS). In this work the results of a set of preliminary tests carried out in stagnant molten lead at 737 K and in lead-bismuth at 573, 673 and 749 K are summarised. The tests were conducted for 700, 1200, 1500 and 5000 h. Three steels were tested: two martensitic steels (mod. F82H and MANET II) and one austenitic steel (AISI 316L). The martensitic steels underwent oxidation phenomena at the higher testing temperature, due to oxygen dissolved in the melts. At a lower test temperature (573 K) and higher exposure time (5000 h) the oxidation rate of the martensitic steel seems to be lower and the developed oxide layer protective against liquid metal corrosion. The austenitic steel, in turn, exhibited an acceptable resistance to corrosion-oxidation under the test conditions.

  20. Lead sources and transfer in the coastal Mediterranean: evidence from stable lead isotopes in marine particles

    Science.gov (United States)

    Alleman, L. Y.; Hamelin, B.; Véron, A. J.; Miquel, J.-C.; Heussner, S.

    Time series of settling and suspended particles have been collected by sediment traps and in situ pumps respectively, under contrasted hydrographic conditions in the Gulf of Lions and the Ligurian Sea, northwestern Mediterranean. Lead concentrations measured in sediment trap samples vary from 41±7 ppm in the Ligurian Sea to 58±10 ppm in the Gulf of Lions. These concentrations, 2-10 times lower than those measured previously in the Gulf of Lions, reflect the reduction of lead fallout from gasoline during the last decade. While atmospheric lead still originates mainly from anthropogenic emissions (automotive and industrial exhausts), stable lead isotopes demonstrate that anthropogenic and lithogenic lead are in similar proportions in the marine particles from the northwestern Mediterranean. Sequential extraction analyses performed on trap samples suggest that the isotopic variations can be explained by a three-component mixing between anthropogenic, natural soluble, and natural refractory sources. In the suspended particulate matter from the Gulf of Lions, lead concentrations range from 0.2 to 30 ng/ l, with isotopic compositions comparable to those of the settling particles ( 206Pb/ 207Pb from 1.165 to 1.178). This indicates a common origin in these two types of particles, probably mainly controlled by the Rhône River discharge and by resuspension processes on the continental shelf. By contrast, lead concentrations are lower in the suspended matter samples from the Ligurian Sea (0.5 to 1.7 ng/ l). In this case, the isotopic signature (1.165±0.002) is in equilibrium with the dissolved fraction, as previously found in other oligotrophic sites in the open ocean, where the suspended particles are mainly of biological origin and lead essentially authigenic in these particles.

  1. The Prevalence of Longevity Among Leading Brands

    Directory of Open Access Journals (Sweden)

    Bradford T. Hudson

    2014-10-01

    Full Text Available The longevity of brands is embedded in scholarship involving brand processes that evolve over time such as brand equity, loyalty, nostalgia, and lifecycle. It is also an important conceptual element in the emerging topic of brand heritage. This paper offers new insight regarding the prevalence of brand longevity in a variety of industries, based on historical research about 148 leading brands ranked in prior studies by the consulting firm Interbrand. The author finds that a significant proportion (64 brands representing 43% of the total number are aged 100 years or more. The oldest brands are grouped in the food industry, while some of the youngest brands are grouped in the hospitality industry. The author applies the principles of scale and scope from the work of business historian Alfred Chandler to explain the timing of this industry emergence. The advanced age of many leading brands suggests the need for stewardship to preserve and protect the equity that resides in historic brands, and supports the argument that further attention should be directed toward the study of brand heritage effects.

  2. Innovation Management, Lead Users and Social Media

    DEFF Research Database (Denmark)

    Ernst, M.; Brem, Alexander; Voigt, K.-I.

    2013-01-01

    Purpose — With the rise of social media, the practice of innovation management is changing rapidly as well. While the opening up of corporate innovation processes can be observed in literature as well as in practice (commonly known as “Open Innovation”), we draw the reader’s attention to the stra......Purpose — With the rise of social media, the practice of innovation management is changing rapidly as well. While the opening up of corporate innovation processes can be observed in literature as well as in practice (commonly known as “Open Innovation”), we draw the reader’s attention...... to the strategic potential of social media in innovation management. For this, a conceptual framework will be introduced. Design/methodology/approach — In this chapter, we compare established concepts of knowledge management to potentials of social media in this field, which offer more efficient and promising ways...... to integrate external knowledge into innovation processes. This approach is discussed by considering the integration of customers and especially Lead-Users into corporate product development. Based on the concept of Open Innovation, we reflect the role of Lead-Users in the innovation process critically...

  3. Devitrification properties of lead borate glasses

    Science.gov (United States)

    Bajaj, Anu; Khanna, Atul; Krishnan, K.; Aggarwal, Suresh K.

    2013-06-01

    Lead borate glasses containing 30 to 60 mol% PbO were prepared by melt quenching technique and devitrified by long duration heat treament in the supercooled region. Glasses crystallized on heating above their glass transition temperature, and the crystalline phases produced on devitrification were characterized by XRD and DSC analyses. Glass with 30 mol% PbO slowly formed a solid solution of Pb6B10O21 and Pb5B8O17 crystalline phases, while glasses with 40 and 50 mol% PbO formed a mixture of Pb6B10O21, Pb5B8O17 and the remanent glassy phase. Glasses with higher PbO concentration of 56 to 60 mol% devitrified completely and produced only Pb5B8O17 crystalline phase. Lead borate glasses with PbO concentration of 40 to 50 mol% showed maximum thermal stability against devitrification, the ease of crystallization of glasses was correlated with the fraction of tetrahedral borons in them.

  4. Lead removal by Spirulina platensis biomass.

    Science.gov (United States)

    Al-Homaidan, Ali A; Al-Abbad, Aljawharah F; Al-Hazzani, Amal A; Al-Ghanayem, Abdullah A; Alabdullatif, Jamila A

    2016-01-01

    In this investigation, we report on the biosorption of Pb (II) from aqueous solutions by the nonliving biomass of the micro-alga (cyanobacterium) Spirulina platensis. Propagation of the micro-alga was carried out in outside oblong raceway ponds. The biomass was cleaned, dried and used for the investigation. The effects of pH, adsorbent dose, temperature, initial concentration of Pb (II), and contact time on the adsorption of lead by the dry biomass were studied. The experiments were carried out in 250 ml conical flasks containing 100 ml of test solutions using an orbital incubator at 150 rpm. Concentrations of the metal before and after the experiments were measured using Atomic Absorption Spectrophotometer. Very high levels of Pb (II) removal (>91%) were obtained. The optimum conditions for maximal adsorption by S. platensis were found to be pH 3; 2 g of adsorbent dose; incubation at 26°C; 100 mg/l of lead initial concentration and 60 minutes of contact time. The experimental data fitted well with Freundlich isotherm equation with R(2) values greater than 0.97. Based on our results, we recommend the utilization of S. platensis biomass for heavy metal removal from aqueous solutions.

  5. Exploring minijets beyond the leading power

    CERN Document Server

    Kotko, P; Strikman, M

    2016-01-01

    The crucial parameter of the current Monte Carlo models of high energy hadron-hadron interaction is the transverse momentum cutoff $p_{T0}$ for parton-parton interactions which slowly grows with energy and regularizes the cross section. This modification of the collinear factorization formula goes beyond the leading power and thus a natural question arises if such cutoff can be extracted from a formalism which takes into account power corrections. In this work, we consider the High Energy Factorization (HEF) valid at small $x$ and a new model, based on a similar principle to HEF, which in addition has a limit respecting the Dokshitzer-Dyakonov-Troyan formula for the dijet momentum disbalance spectrum. Minijet cross section and its suppression is then analyzed in two ways. First, we study minijets directly in the low-$p_T$ region, and demonstrate that higher twist corrections do generate suppression of the inclusive jet production cross section though these effects are not leading to the increase of the cutoff...

  6. Processes That Leading to Medical Malpractice

    Directory of Open Access Journals (Sweden)

    Özlem Yıldırım

    2012-12-01

    Full Text Available The new Turkish Penal Code which came into force in June 2005 has brought some changes in the definitions of the legal and penal responsibilities of physicians. On the other hand, the changing conditions of the current health practices and the commercial concerns taking the lead have brought serious doubts about a physician-patient relationship based on trust. As a result, in our country, medical malpractice claims against physicians have significantly increased in recent years. In the last 10 years, the subject has been discussed in various platforms and there is a dynamic process that continues the search for solutions. To date, considering the emerging cases of medical malpractice statistics, it is remarkable that the most frequent claim against both physicians and other health personnel is the complaint about "not fulfilling their obligation of duty of care". In this review, we examined the basic concepts and processes leading to medical malpractice, which has become a serious threat to physicians, in order to improve physicians' knowledge about this phenomenon. (Turk J Ophthalmol 2012; 42: Supplement 78-81

  7. Proatherogenic pathways leading to vascular calcification

    Energy Technology Data Exchange (ETDEWEB)

    Mazzini, Michael J. [Department of Cardiology, Boston University Medical Center, Boston, MA (United States); Schulze, P. Christian [Department of Medicine, Boston University Medical Center, Boston, MA (United States)]. E-mail: christian.schulze@bmc.org

    2006-03-15

    Cardiovascular disease is the leading cause of morbidity and mortality in the western world and atherosclerosis is the major common underlying disease. The pathogenesis of atherosclerosis involves local vascular injury, inflammation and oxidative stress as well as vascular calcification. Vascular calcification has long been regarded as a degenerative process leading to mineral deposition in the vascular wall characteristic for late stages of atherosclerosis. However, recent studies identified vascular calcification in early stages of atherosclerosis and its occurrence has been linked to clinical events in patients with cardiovascular disease. Its degree correlates with local vascular inflammation and with the overall impact and the progression of atherosclerosis. Over the last decade, diverse and highly regulated molecular signaling cascades controlling vascular calcification have been described. Local and circulating molecules such as osteopontin, osteoprogerin, leptin and matrix Gla protein were identified as critical regulators of vascular calcification. We here review the current knowledge on molecular pathways of vascular calcification and their relevance for the progression of cardiovascular disease.

  8. Precipitation in a lead calcium tin anode

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Gonzalez, Francisco A., E-mail: fco.aurelio@inbox.com [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon (Mexico); Centro de Innovacion, Investigacion y Desarrollo en Ingenieria y Tecnologia, Universidad Autonoma de Nuevo Leon (Mexico); Camurri, Carlos G., E-mail: ccamurri@udec.cl [Departamento de Ingenieria de Materiales, Universidad de Concepcion (Chile); Carrasco, Claudia A., E-mail: ccarrascoc@udec.cl [Departamento de Ingenieria de Materiales, Universidad de Concepcion (Chile); Colas, Rafael, E-mail: rafael.colas@uanl.edu.mx [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon (Mexico); Centro de Innovacion, Investigacion y Desarrollo en Ingenieria y Tecnologia, Universidad Autonoma de Nuevo Leon (Mexico)

    2012-02-15

    Samples from a hot rolled sheet of a tin and calcium bearing lead alloy were solution heat treated at 300 Degree-Sign C and cooled down to room temperature at different rates; these samples were left at room temperature to study natural precipitation of CaSn{sub 3} particles. The samples were aged for 45 days before analysing their microstructure, which was carried out in a scanning electron microscope using secondary and backscattered electron detectors. Selected X-ray spectra analyses were conducted to verify the nature of the precipitates. Images were taken at different magnifications in both modes of observation to locate the precipitates and record their position within the images and calculate the distance between them. Differential scanning calorimeter analyses were conducted on selected samples. It was found that the mechanical properties of the material correlate with the minimum average distance between precipitates, which is related to the average cooling rate from solution heat treatment. - Highlights: Black-Right-Pointing-Pointer The distance between precipitates in a lead alloy is recorded. Black-Right-Pointing-Pointer The relationship between the distance and the cooling rate is established. Black-Right-Pointing-Pointer It is found that the strengthening of the alloy depends on the distance between precipitates.

  9. Peltier cooling of superconducting current leads

    Science.gov (United States)

    Gehring, F. K.; Hüttner, M. E.; Huebener, R. P.

    2001-07-01

    An interesting application of Peltier cooling based on the Peltier materials presently available arises for the cooling of current leads connected to superconducting power electronics. By inserting n-doped and p-doped Peltier tablets at the warm end into the circuit, at their warm side the remaining current leads can be Peltier cooled about 50-60 K below room temperature. We have developed an experimental test apparatus for dc operation up to a current of 200 A. Our experiments, performed with Peltier tablets fabricated from n-doped and p-doped Bi 2Te 3, well confirmed the expected Peltier cooling. From our results we estimate the reduction of the thermal losses (by typically 13%) and of the electric power losses (by typically 10%) due to the insertion of the Peltier tablets. In addition to the dc experiments, we have also carried out similar experiments using 50 Hz ac and a bridge circuit yielding a rectified output current. Minimization of the electric contact resistance generated at the surfaces of the Peltier tablets (and of the rectifying diodes required for ac operation) represents an important issue.

  10. Defect Tolerance in Methylammonium Lead Triiodide Perovskite

    Energy Technology Data Exchange (ETDEWEB)

    Steirer, K. Xerxes; Schulz, Philip; Teeter, Glenn; Stevanovic, Vladan; Yang, Mengjin; Zhu, Kai; Berry, Joseph J.

    2016-08-12

    Photovoltaic applications of perovskite semiconductor material systems have generated considerable interest in part because of predictions that primary defect energy levels reside outside the bandgap. We present experimental evidence that this enabling material property is present in the halide-lead perovskite, CH3NH3PbI3 (MAPbI3), consistent with theoretical predictions. By performing X-ray photoemission spectroscopy, we induce and track dynamic chemical and electronic transformations in the perovskite. These data show compositional changes that begin immediately with exposure to X-ray irradiation, whereas the predominant electronic structure of the thin film on compact TiO2 appears tolerant to the formation of compensating defect pairs of VI and VMA and for a large range of I/Pb ratios. Changing film composition is correlated with a shift of the valence-band maximum only as the halide-lead ratio drops below 2.5. This delay is attributed to the invariance of MAPbI3 electronic structure to distributed defects that can significantly transform the electronic density of states only when in high concentrations.

  11. Microhardness studies of nanocrystalline lead molybdate

    Energy Technology Data Exchange (ETDEWEB)

    Anandakumar, V.M. [Department of Physics, University of Kerala, Kariavattom P.O., Thiruvananthapuram 695581 (India); Department of Physics, Mahatma Gandhi College, Pattom Palace P.O., Thiruvananthapuram 695004 (India); Abdul Khadar, M., E-mail: mabdulkhadar@rediffmail.com [Department of Physics, University of Kerala, Kariavattom P.O., Thiruvananthapuram 695581 (India); Centre for Nanoscience and Nanotechnology, University of Kerala, Kariavattom P.O., Thiruvananthapuram 695581 (India)

    2009-08-30

    Nanocrystalline lead molybdate (PbMoO{sub 4}) of four different grain sizes were synthesized through chemical precipitation technique and the grain sizes and crystal structure are determined using the broadening of X-ray diffraction patterns and transmission electron microscopy. The microhardness of nanocrystalline lead molybdate (PbMoO{sub 4}) with different grain sizes were measured using a Vicker's microhardness tester for various applied loads ranging from 0.049 to 1.96 N. The microhardness values showed significant indentation size effect at low indentation loads. The proportional specimen resistance model put forward by Li and Bradt and energy balance model put forward by Gong and Li were used to analyze the behaviour of measured microhardness values under different indentation loads. The microhardness data obtained for samples of different grain sizes showed grain size dependent strengthening obeying normal Hall-Petch relation. The dependence of compacting pressure and annealing temperature on microhardness of the nanostructured sample with grain size of {approx}18 nm were also studied. The samples showed significant increase in microhardness values as the compacting pressure and annealing time were increased. The variation of microhardness of the material with pressure of pelletization and annealing time are discussed in the light of change of pore size distribution of the samples.

  12. Effect of Glycine on Lead Mobilization, Lead-Induced Oxidative Stress, and Hepatic Toxicity in Rats

    Directory of Open Access Journals (Sweden)

    Yolanda Alcaraz-Contreras

    2011-01-01

    Full Text Available The effectiveness of glycine in treating experimental lead intoxication was examined in rats. Male Wistar rats were exposed to 3 g/L lead acetate in drinking water for 5 weeks and treated thereafter with glycine (100 and 500 mg/kg, orally once daily for 5 days or glycine (1000 mg/kg, orally once daily for 28 days. The effect of these treatments on parameters indicative of oxidative stress (glutathione and malondialdehyde levels, the activity of blood -aminolevulinic acid dehydratase, and lead concentration in blood, liver, kidney, brain, and bone were investigated. Liver samples were observed for histopathological changes. Glycine was found to be effective in (1 increasing glutathione levels; (2 reducing malondialdehyde levels; (3 decreasing lead levels in bone with the highest dose. However, glycine had no effect on lead mobilization when 100 and 500 mg/kg glycine were administered. In microscopic examination, glycine showed a protective effect against lead intoxication.

  13. Characterization of nano-lead-doped active carbon and its application in lead-acid battery

    Science.gov (United States)

    Hong, Bo; Jiang, Liangxing; Xue, Haitao; Liu, Fangyang; Jia, Ming; Li, Jie; Liu, Yexiang

    2014-12-01

    In this paper, nano-lead-doped active carbon (nano-Pb/AC) composite with low hydrogen evolution current for lead-acid battery was prepared by ultrasonic-absorption and chemical-precipitate method. The nano-Pb/AC composite was characterized by SEM, EDS and TEM. The electrochemical characterizations are performed by linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) in a three-electrode system. Since intermediate adsorption is the rate-determining step, the hydrogen evolution reaction (HER) is markedly inhibited as the intermediate adsorption impedance of nano-Pb/AC increased. Meanwhile, the working potential of nano-Pb/AC is widened to the whole potential region of Pb negative plate (from -1.36 V to -0.86 V vs. Hg/HgSO4) in lead-acid battery. In addition, nano-Pb can improve the interfacial compatibility between AC and Pb paste, accordingly relieve the symptoms of carbon floatation. Finally, 2.0 V single-cell flooded lead-acid batteries with 1.0 wt.% nano-Pb/AC or 1.0 wt.% AC addition in negative active materials are assembled. The cell performances test results show that the 3 h rate capacity, quick charging performance, high current discharging performance and cycling performance of nano-Pb/AC modified battery are all improved compared with regular lead-acid battery and AC modified lead-acid battery.

  14. Learning to Lead School Turnaround: The Mississippi LEADS Professional Development Model

    Directory of Open Access Journals (Sweden)

    Matthew Clifford

    2013-03-01

    Full Text Available The focus of this paper is on a systematic principal professional development program called “Mississippi LEADS,” which is designed to provide current school principals the technical and practical knowledge that they need to enact comprehensive school turnaround efforts. The Mississippi LEADS professional development program is a year-long training experience that includes executive coaching and establishes a state-wide and district-wide professional support system for principals. The goal of Mississippi LEADS is to turnaround chronically low performing schools by investing in leadership development, rather than replacing the school principal. Although many turnaround efforts begin by replacing principals, Mississippi LEADS administrators view principal replacement as impractical for many rural, impoverished school districts that face educator recruitment challenges. The Mississippi LEADS program theory of action is discussed, which includes formalized classroom work, enactment of ambitious school improvement plans, one-on-one executive coaching, and data monitoring. Early data from the evaluation study indicates that Mississippi LEADS is having expected impacts.

  15. Environmental Lead Pollution and Elevated Blood Lead Levels Among Children in a Rural Area of China

    Science.gov (United States)

    Lin, Sihao; Yu, Ignatius Tak Sun; Tang, Wenjuan; Miao, Jianying; Li, Jin; Wu, Siying; Lin, Xing

    2011-01-01

    Objectives. We investigated environmental lead pollution and its impact on children's blood lead levels (BLLs) in a rural area of China. Methods. In 2007, we studied 379 children younger than 15 years living in 7 villages near lead mines and processing plants, along with a control group of 61 children from another village. We determined their BLLs and collected environmental samples, personal data, and information on other potential exposures. We followed approximately 86% of the children who had high BLLs (> 15 μg/dL) for 1 year. We determined factors influencing BLLs by multivariate linear regression. Results. Lead concentrations in soil and household dust were much higher in polluted villages than in the control village, and more children in the polluted area than in the control village had elevated BLLs (87%, 16.4 μg/dL vs 20%, 7.1 μg/dL). Increased BLL was independently associated with environmental lead levels. We found a significant reduction of 5 micrograms per deciliter when we retested children after 1 year. Conclusions. Our data show that the lead industry caused serious environmental pollution that led to high BLLs in children living nearby. PMID:21421950

  16. 40 CFR 52.58 - Control strategy: Lead.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy: Lead. 52.58 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Alabama § 52.58 Control strategy: Lead. The lead plan... the lead standard throughout Alabama. The lead plan submitted by the State on October 7, 1985,...

  17. Dislocation of an infected and abandoned pacemaker lead.

    Science.gov (United States)

    Kostopoulou, Anna G; Kyrzopoulos, Stamatios D; Livanis, Efthimios G

    2012-11-01

    We present a case of pacemaker lead dislodgment in an 83-year-old patient with a pacemaker infection. Initially, the generator and the proximal part of the leads were removed, and the remaining leads were severed and abandoned. Twenty-five days later, dislodgment of both abandoned leads and systemic infection were documented. The leads were then surgically removed without further complications.

  18. Reducing Lead in Drinking Water: A Manual for Minnesota's Schools.

    Science.gov (United States)

    Minnesota State Dept. of Health, St. Paul.

    This manual was designed to assist Minnesota's schools in minimizing the consumption of lead in drinking water by students and staff. It offers step-by-step instructions for testing and reducing lead in drinking water. The manual answers: Why is lead a health concern? How are children exposed to lead? Why is lead a special concern for schools? How…

  19. Blood lead levels and risk factors for lead poisoning among children in Jakarta, Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Albalak, Rachel; Noonan, Gary; Buchanan, Sharunda; Flanders, W. Dana; Gotway-Crawford, Carol; Blumenthal, Wendy; Curtis, Gerald; McGeehin, Michael A. [Division of Environmental Hazards and Health Effects, National Center for Environmental Health, Centers for Disease Control and Prevention, 1600 Clifton Rd. Mailstop E-19, Atlanta, GA 30333 (United States); Kim, Dennis; Tan, Regina [Epidemic Intelligence Service, Epidemiology Program Office, Centers for Disease Control and Prevention, 1600 Clifton Rd. Mailstop D-18, Atlanta, GA 30333 (United States); Jones, Robert L. [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 1600 Clifton Rd. Mailstop F-18, Atlanta, GA 30333 (United States); Sulaiman, Rini [Swisscontact, Jl. Wijaya XII No. 44, Jakarta (Indonesia) 12160

    2003-01-01

    The phase-out of leaded gasoline began in Jakarta, Indonesia on July 1, 2001. We evaluated mean blood lead levels (BLLs) and the prevalence of elevated BLLs of Jakarta school children and assessed risk factors for lead exposure in these children before the beginning of the phase-out activities. The study involved a population-based, cross-sectional blood lead survey that included capillary blood lead sampling and a brief questionnaire on risk factors for lead poisoning. A cluster survey design was used. Forty clusters, defined as primary schools in Jakarta, and 15 2nd- and 3rd-grade children in each cluster were randomly selected for participation in the study. The average age of children in this study was 8.6 years (range 6-12) and the geometric mean BLL of the children was 8.6 {mu}g/dl (median: 8.6 {mu}g/dl; range: 2.6-24.1 {mu}g/dl) (n=397). Thirty-five percent of children had BLLs {>=}10 {mu}g/dl and 2.4% had BLLs {>=}20 {mu}g/dl. Approximately one-fourth of children had BLLs 10-14.9 {mu}g/dl. In multivariate models, level of education of the child's primary caregiver, water collection method, home varnishing and occupational recycling of metals, other than lead, by a family member were predictors of log BLLs after adjustment for age and sex. BLLs of children who lived near a highway or major intersection were significantly higher than those of children who lived near a street with little or no traffic when level of education was not included in the model. Water collection method was a significant predictor of BLLs {>=}10 {mu}g/dl after adjustment for age and sex. BLLs in children in this study were moderately high and consistent with BLLs of children in other countries where leaded gasoline is used. With the phase-out of leaded gasoline, BLLs of children in Jakarta are expected to rapidly decline as they have in other countries that have phased lead out of gasoline.

  20. Results of transvenous lead extraction of coronary sinus leads in patients with cardiac resynchronization therapy

    Institute of Scientific and Technical Information of China (English)

    Christoph T.Starck; Etem Caliskan; Holger Klein; Jan Steffel; Felix Schoenrath; Volkmar Falk

    2013-01-01

    Background The need for transvenous lead extraction procedures of coronary sinus (CS) leads is increasing due to rising numbers of implanted cardiac resynchronization therapy devices during the past decade.Methods From January 2009 to June 2013,27 CS leads were scheduled for extraction in 27 patients (mean age (63.1±14.6) years).Indications for lead extraction were infection in 13 and lead dysfunction in 14 cases.Isolated extraction of CS leads was performed in eight,extraction of multiple leads in 19 cases.Among leads with an implant time of >12months (n=19) mean implant duration (MID) was (46.4±15.2) (12-76) months.Groups were formed depending on infectious or non-infectious indications (INF vs.Non-INF),and the use or non-use of extraction tools (ET1 vs.ET0).Results Among patients with an implant duration of >12 months,complete procedural success was 94.7% and clinical success 100%.Operative mortality was zero.In the INF versus NON-INF groups complete procedural success (100%vs.91.7%,P=0.43),mean number of required extraction tools (0.7 (0-2) vs.0.9 (0-3),P=0.65) and MID (49.1±15.0 vs.44.7±15.8,P=0.83) did not differ significantly.Comparing the groups ET1 and ET0 showed no significant differences in complications (n=1 vs.n=1,P=0.81) and MID (47.0±17.5 vs.45.5±12.6,P=0.71).Conclusions In specialized centers transvenous lead extraction of coronary sinus leads with a mean implant duration of almost four years can be performed safely and effectively.Neither non-infectious indications nor the use of extraction tools negatively affected the outcome of the procedure.

  1. Lead, mercury, and cadmium in breast milk

    Directory of Open Access Journals (Sweden)

    Kadriye Yurdakök

    2015-10-01

    Full Text Available Toxic heavy metals are the major source of environmental pollution in this new millennium. Lead, mercury, and cadmium are the most common toxic heavy metals in the environment. There is no known function of these toxic heavy metals in the human body. In females, toxic heavy metals can be accumulated in maternal body before pregnancy and may be transferred to fetus through placenta and later, via breast milk. Lead previously accumulated in maternal bones can be mobilized along with calcium in order to meet increased calcium needs of the fetus in pregnant women and for the calcium needs in human milk during lactation. Human fetus and infants are susceptible to heavy metal toxicity passing through placenta and breastmilk due to rapid growth and development of organs and tissues, especially central nervous system. However most of the damage is already done by the time the infant is born. Intrauterine lead exposure can cause growth retardation, cognitive dysfunction, low IQ scores on ability tests, and low performance in school. Biological samples, such as umbilical cord blood and breast milk, and less commonly infant hair, are used for biomonitoring of intra-uterine exposure to these toxic chemicals. Although toxic metals and other pollutants may be excreted into breast milk, their effects are unknown and this topic is subject of a growing body of research. Despite the possibility of harm from environmental contaminants in breast milk, breastfeeding is still recommended as the best infant feeding method. In fact, the species-specific components present in breast milk protect infants against infections; promote immune and neurologic system development; and may decrease the risk of disease, including allergies, obesity, insulin-dependent diabetes mellitus, inflammatory bowel disease, and sudden infant death syndrome. Breastfeeding also facilitates maternal-infant attachment. The potential risk of environmental contaminants that can be transferred from

  2. [Reasons for the changes in anthropogenic lead flows of China].

    Science.gov (United States)

    Ma, Lan; Mao, Jian-Su

    2014-08-01

    In recent years, accompanied by a series of comprehensive improvement actions on lead pollution, anthropogenic lead flows of China have somewhat changed; by exploring the reasons, some references can be provided for further improvement in resource utilization and environment quality. In this paper, based on the framework of lead flow analysis, the causes of changes in lead flows were identified and divided into scale factors and technical factors. Based on that and taking indices such as the quantities of lead production and recovered lead scraps, and lead recycling rate and emission rates as the scale and technical indices, respectively, the reasons for the changes of lead flow in our country were analyzed from the aspects of consumption, trade, technology, management and so on. The results showed: the domestic consumption of lead products has been gro wing quickly at an average annual rate of 24.7%, which pulled the growth of domestic lead consumption; The growth of lead consumption further increased the growth of lead production at an average annual rate of 14.2%, which finally pulled the growth of domestic lead ore resource consumption, lead concentrates net imports and lead scraps recovering; The increases in domestic consumption ratio of final lead products promoted the improvement of the lead recycling rate; As national management was strengthened, most lead-enterprises with small scale and old-dated technologies were closed, meanwhile, some advanced technologies were encouraged to be employed, thus the general resource utilization rate was improved and environmental lead emissions rate was reduced.

  3. Novel lead-graphene and lead-graphite metallic composite materials for possible applications as positive electrode grid in lead-acid battery

    Science.gov (United States)

    Yolshina, L. A.; Yolshina, V. A.; Yolshin, A. N.; Plaksin, S. V.

    2015-03-01

    Novel lead-graphene and lead-graphite metallic composites which melt at temperature of the melting point of lead were investigated as possible positive current collectors for lead acid batteries in sulfuric acid solution. Scanning electron microscopy, Raman spectroscopy, difference scanning calorimetry, cyclic voltammetry and prolonged corrosion tests were employed to characterize the effect of the newly proposed lead-carbon metallic composites on the structure and electrochemical properties of positive grid material. Both lead-graphene and lead-graphite metallic composite materials show the similar electrochemical characteristics to metallic lead in the voltage range where the positive electrodes of lead acid batteries operate. It has been shown that carbon both as graphene and graphite does not participate in the electrochemical process but improve corrosion and electrochemical characteristics of both metallic composite materials. No products of interaction of lead with sulfuric acid were formed on the surface of graphene and graphite so as it was not found additional peaks of carbon discharge on voltammograms which could be attributed to the carbon. Graphene inclusions in lead prevent formation of leady oxide nanocrystals which deteriorate discharge characteristics of positive electrode of LAB. Both lead-graphene alloy and lead-graphite metallic composite proved excellent electrochemical and corrosion behavior and can be used as positive grids in lead acid batteries of new generation.

  4. A systematic review on food lead concentration and dietary lead exposure in China

    Institute of Scientific and Technical Information of China (English)

    Jin Yingliang; Liu Pei; Wu Yongning; Min Jie; Wang Cannan; Sun Jinfang; Zhang Yafei

    2014-01-01

    Background By synthesizing results from primary studies,systematic review can provide empirical information of concerned problems.This study aimed to review the available surveillance data from studies reporting the contamination surveillance of food lead in China.Methods Relevant studies were identified by systematically searching Chinese Biological Medicine Database and China National Knowledge Infrastructure using the key term of "lead" for surveillance data published in Chinese between 2006 and 2012.To avoid potential selection bias,all articles were evaluated by two independent reviewers,and the disagreements were resolved by discussion or the third author was asked to arbitrate.Results Among 269 identified publications on surveillance data of lead in food,43 articles met the defined inclusion criteria.The food samples were divided into 11 groups (cereal grains and pulses,fish,eggs,vegetables,meat,edible fungi,milk and dairy products,fruits,offal,tea and preserved egg).Surveillance data of publications were reviewed to calculate the weighted mean and rate exceeding maximum levels.Our results indicated that the highest lead concentration was 1.937 mg/kg in tea.The total pementage of samples exceeding the maximum levels was 5.57%.Dietary exposure to lead was assessed by combining the weighted mean concentration of surveillance data with national consumption data in 2002.In this review,dietary intake of lead was 1.232 μg/kg b.w./day.Conclusion Further control measures should be taken to reduce exposure to lead,from both dietary and non-dietary sources.

  5. Comparative value of phosphate sources on the immobilization of lead, and leaching of lead and phosphorus in lead contaminated soils.

    Science.gov (United States)

    Park, Jin Hee; Bolan, Nanthi; Megharaj, Mallavarapu; Naidu, Ravi

    2011-01-15

    The mobility and bioavailability of lead (Pb) in soils can be mitigated by its immobilization using both soluble and insoluble phosphate (P) compounds. The effectiveness of insoluble P sources on Pb immobilization depends on their rate of dissolution which can be enhanced by phosphate solubilizing bacteria (PSB). In this study, the effect of soluble (potassium dihydrogen phosphate) and insoluble (rock phosphate in the presence and absence of PSB) P compounds on the immobilization of Pb, and leaching of Pb and P was examined using both naturally contaminated (SR soil: NH₄NO₃ extractable Pb: 28.7 mg/kg, pH: 5.88, organic matter: 0.7%) and Pb spiked (AH soil: NH(4)NO(3) extractable Pb: 42.7 mg/kg, pH: 5.23, organic matter: 10.9%) soils. Phosphate compounds were added at the rate of 200 mg P/kg and 800 mg P/kg for SR and AH soils, respectively. Soluble P treatment immobilized 80% and 57% of Pb in SR and AH soils, respectively. Insoluble rock phosphate immobilized 40% and 9% of Pb without PSB, and 60% and 17% with PSB in SR and AH soils, respectively. Lead leaching was the lowest when soils were amended with rock phosphate in the presence of PSB, which reduced Pb leaching by 36% for SR soil and 18% for AH soil compared to the control. The leaching of Pb increased when the soils were amended with soluble P because soluble P treatment increased dissolved organic carbon (DOC) concentration of soil, thereby increasing Pb mobility. Soluble P treatment significantly increased P leaching and 9% of total added P was leached from low P retaining AH soil. The optimum level of P amendment is a critical issue when soluble P is used as a Pb immobilizing agent because of eutrophication resulting from excessive P leaching to surface and ground water. While the soluble P compound was effective in the immobilization of Pb, it resulted in P leaching which increased with increasing levels of P addition. However, rock phosphate amendment with PSB achieved the immobilization of Pb with

  6. Leading the implementation of ICT innovations

    DEFF Research Database (Denmark)

    Hansen, Morten Balle; Nørup, Iben

    2017-01-01

    This article analyzes the associations between leadership, implementation of information and communications technology (ICT) innovations, and performance. Reviewing theories and empirical evidence from the literature on leading change, ICT innovations and performance hypotheses are formulated...... and tested in an analysis of the implementation of an ICT innovation in a Danish multi-site hospital. In a quasi-experimental research design using panel data, survey responses from more than 2000 employees before and after the implementation were generated as well as qualitative interviews with change...... agents. The findings indicate how differences in leadership during the ICT implementation process can have an important impact on performance after the ICT implementation process. The mobilization of initial support; directive leadership through information and technical assistance; participative...

  7. Esophageal stent migration leads to intestinal obstruction

    Directory of Open Access Journals (Sweden)

    Oguzhan Karatepe

    2009-07-01

    Full Text Available Background: Self-expanding metallic stents are the devices of choice in the treatment of malign or benign strictures of esophagus. Stent migration is a well-known complication of this procedure. Aims: We report a case of intestinal obstruction caused by esophageal stent migration, in which surgical intervention was used. Methods: A 65-year-old woman, who had a medical history of gastric cancer operation and esophageal stent application admitted to our emergeny department with a 48-hour history of abdominal pain, nausea and vomiting. An emergeny laparotomy was performed and the migrated stent leading to intestinal obstruction was removed. Results: The patient recovered without incident and was discharged on postoperative day 3. Conclusion: This case illustrates that esophageal stent migration has to be considered as a potential life-threatening complication.

  8. Optimization of propafenone analogues as antimalarial leads.

    Science.gov (United States)

    Lowes, David J; Guiguemde, W Armand; Connelly, Michele C; Zhu, Fangyi; Sigal, Martina S; Clark, Julie A; Lemoff, Andrew S; Derisi, Joseph L; Wilson, Emily B; Guy, R Kiplin

    2011-11-10

    Propafenone, a class Ic antiarrythmic drug, inhibits growth of cultured Plasmodium falciparum. While the drug's potency is significant, further development of propafenone as an antimalarial would require divorcing the antimalarial and cardiac activities as well as improving the pharmacokinetic profile of the drug. A small array of propafenone analogues was designed and synthesized to address the cardiac ion channel and PK liabilities. Testing of this array revealed potent inhibitors of the 3D7 (drug sensitive) and K1 (drug resistant) strains of P. falciparum that possessed significantly reduced ion channel effects and improved metabolic stability. Propafenone analogues are unusual among antimalarial leads in that they are more potent against the multidrug resistant K1 strain of P. falciparum compared to the 3D7 strain.

  9. A gingival manifestation of histoplasmosis leading diagnosis

    Directory of Open Access Journals (Sweden)

    Marco Tullio Brazão-Silva

    2013-01-01

    Full Text Available Histoplasmosis is a world-wide distributed deep mycosis caused by Histoplasma capsulatum which has been endemic in many countries. We present a case involving an immunocompetent man evidencing the necessity of a multidisciplinary approach and rational requisition of exams. The disease has started as a pulmonary disease mimicking tuberculosis, although the exams have been negative. Immunodiffusion test indicate histoplasmosis, not confirmed by culture of sputum. After days the patient was forwarded by a private doctor for evaluation of oral lesions at our Department of Stomatology. An incisional biopsy revealed a nonspecific granulomatous inflammation and the Grocott-Gomori methenamine silver stain identified scarce oval structures that could represent fungal yeast. Sampling oral lesions with swab, it was observed the typical growth of H. capsulatum on culture. This case highlights the importance of doctor′s integration diagnosing histoplasmosis, while a wide spectrum of clinical manifestations should be expected. Oral lesions may be the critical manifestation leading diagnosis.

  10. Surprise Leads to Noisier Perceptual Decisions

    Directory of Open Access Journals (Sweden)

    Marta I Garrido

    2011-02-01

    Full Text Available Surprising events in the environment can impair task performance. This might be due to complete distraction, leading to lapses during which performance is reduced to guessing. Alternatively, unpredictability might cause a graded withdrawal of perceptual resources from the task at hand and thereby reduce sensitivity. Here we attempt to distinguish between these two mechanisms. Listeners performed a novel auditory pitch—duration discrimination, where stimulus loudness changed occasionally and incidentally to the task. Responses were slower and less accurate in the surprising condition, where loudness changed unpredictably, than in the predictable condition, where the loudness was held constant. By explicitly modelling both lapses and changes in sensitivity, we found that unpredictable changes diminished sensitivity but did not increase the rate of lapses. These findings suggest that background environmental uncertainty can disrupt goal-directed behaviour. This graded processing strategy might be adaptive in potentially threatening contexts, and reflect a flexible system for automatic allocation of perceptual resources.

  11. Hydrail : a parade Canada can lead

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, S. [Mooresville-South Iredell Economic Development Corp., NC (United States). Hydrogen Economy Advancement Team

    2007-07-01

    This paper suggested that Canada can play a leading role in the development of hydrogen railways. Canadian scientists were among the first to test and develop the world's first hydrogen locomotive, and Canadian rail firms are now in a position to play a prominent role in the passenger hydrogen rail equipment market. A hydrogen railway will be built as part of Vancouver's 2010 winter olympics infrastructure. The Fraser Valley Heritage Railway Society is planning to use hydrogen to power vintage inter-urban trolley cars connecting Surrey communities. A Canadian manufactured hybrid locomotive will be modified to create the world's first hydrogen rail switch engine. It was concluded that hydrogen's storage capacity makes it an enabling technology for other other renewable energy technologies. Future hydrogen storage technologies will probably be hybridized with fuel cells in highly efficient applications. 1 ref.

  12. Thermal expansion in lead zirconate titanate

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The volume anomalies with temperature variations in tin-modified lead zirconate titanate ceramics are investigated. Experimental results show that the volume changes are related to the phase transitions induced with temperature. The magnitude and orientation of crystal volume changes are dependent on the particular phase transition. When antiferroelectrics is transformed to ferroelectrics or paraelectrics the volume expands. Oppositely when ferroelectrics is transformed to antiferroelectrics or paraelectrics the volume contracts. In the transition of antiferroelectric orthorhombic structure to tetragonal structure or ferroelectric low-temperature rhombohedral structure to high-tem- perature rhombohedral structure, there are also revealed apparent anomalies in the curves of thermal expansion. Among them, the volume strain caused by the transition between antiferroelectrics and ferroelectrics is the biggest in magnitude, and the linear expansion dL/L0 and the expansion coefficient (dL/L0)/dT can reach 2.810?3 and 7.5 × 10?4 K?1 respectively.

  13. Tsunami focusing and leading wave height

    Science.gov (United States)

    Kanoglu, Utku

    2016-04-01

    and Synolakis, 1994, Proc. R. Soc. A: Math. Phys. Eng. Sci., 445, 99-112) with a finite crest length, which is most common tsunami initial waveform. We fit earthquake initial waveform calculated through Okada (1985, Bull. Seismol. Soc. Am. 75, 1135-1040) to the N-wave form presented by Tadepalli and Synolakis (1994). First, we investigate focusing phenomena as presented by Kanoglu et al. (2013, Proc. R. Soc. A: Math. Phys. Eng. Sci., 469, 20130015) and compare our results with their non-dispersive and dispersive linear analytical solutions. We confirm focusing phenomena, which amplify the wave height in the leading depression side. We then study sequencing of an N-wave profile with a finite crest length. Our preliminary results show that sequencing is more pronounced on the leading depression side. We perform parametric study to understand sequencing in terms of N-wave, hence earthquake, parameters. We then discuss the results both in terms of tsunami focusing and leading wave amplitude. Acknowledgment: The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no 603839 (Project ASTARTE - Assessment, Strategy and Risk Reduction for Tsunamis in Europe).

  14. Effect of lead on root growth.

    Science.gov (United States)

    Fahr, Mouna; Laplaze, Laurent; Bendaou, Najib; Hocher, Valerie; Mzibri, Mohamed El; Bogusz, Didier; Smouni, Abdelaziz

    2013-01-01

    Lead (Pb) is one of the most widespread heavy metal contaminant in soils. It is highly toxic to living organisms. Pb has no biological function but can cause morphological, physiological, and biochemical dysfunctions in plants. Plants have developed a wide range of tolerance mechanisms that are activated in response to Pb exposure. Pb affects plants primarily through their root systems. Plant roots rapidly respond either (i) by the synthesis and deposition of callose, creating a barrier that stops Pb entering (ii) through the uptake of large amounts of Pb and its sequestration in the vacuole accompanied by changes in root growth and branching pattern or (iii) by its translocation to the aboveground parts of plant in the case of hyperaccumulators plants. Here we review the interactions of roots with the presence of Pb in the rhizosphere and the effect of Pb on the physiological and biochemical mechanisms of root development.

  15. Ferroelastic Fingerprints in Methylammonium Lead Iodide Perovskite

    KAUST Repository

    Hermes, Ilka M.

    2016-02-12

    Methylammonium lead iodide (MAPbI3) perovskite materials show an outstanding performance in photovoltaic devices. However, certain material properties, especially the possible ferroic behavior, remain unclear. We observed distinct nanoscale periodic domains in the piezoresponse of MAPbI3(Cl) grains. The structure and the orientation of these striped domains indicate ferroelasticity as their origin. By correlating vertical and lateral piezoresponse force microscopy experiments performed at different sample orientations with x-ray diffraction, the preferred domain orientation was suggested to be the a1-a2-phase. The observation of these ferroelastic fingerprints appears to strongly depend on the film texture and thus the preparation route. The formation of the ferroelastic twin domains could be induced by internal strain during the cubic-tetragonal phase transition.

  16. Novel thermal expansion of lead titanate

    Institute of Scientific and Technical Information of China (English)

    XING Xianran; DENG Jinxia; CHEN Jun; LIU Guirong

    2003-01-01

    Lattice parameters of lead titanate were precisely re-determined in the ternperature range of-150-950℃ by high precision XRPD measurements. It was clarified that there was no any evidence for a new phase transition at low temperatures. Tetragonal distortion strain decreases with temperature increasing. A novel thermal expansion was observed, positive thermal expansion from-150℃ to room temperature (RT) and above 490℃, and the negative thermal expansion in the temperature range of RT-490℃. A big jump of thermal expansion coefficient is attributed to the tetragonal-cubic phase transition. A rationalization for the negative thermal expansion of PbTiO3 is due to the decrease of anion-anion repulsion as polyhedra become more regular at heating. The mechanisms of positive and negative thermal expansions were elucidated as the same nature in the homogenous tetragonal phase at present case.

  17. Parallel Error Detection for Leading Zero Anticipation

    Institute of Scientific and Technical Information of China (English)

    Ge Zhang; Wei-Wu Hu; Zi-Chu Qi

    2006-01-01

    The algorithm and its implementation of the leading zero anticipation (LZA) are very vital for the performance of a high-speed floating-point adder in today's state of art microprocessor design. Unfortunately, in predicting "shift amount"by a conventional LZA design, the result could be off by one position. This paper presents a novel parallel error detection algorithm for a general-case LZA. The proposed approach enables parallel execution of conventional LZA and its error detection, so that the error-indication signal can be generated earlier in the stage of normalization, thus reducing the critical path and improving overall performance. The circuit implementation of this algorithm also shows its advantages of area and power compared with other previous work.

  18. 77 FR 64997 - Advisory Committee on Childhood Lead Poisoning Prevention

    Science.gov (United States)

    2012-10-24

    ... HUMAN SERVICES Centers for Disease Control and Prevention Advisory Committee on Childhood Lead Poisoning... poisoning prevention efforts. The committee also reviews and reports regularly on childhood lead poisoning prevention practices and recommends improvements in national childhood lead poisoning prevention...

  19. Manganese incorporation into ferroelectric lead titanate

    Science.gov (United States)

    Stoupin, Stanislav

    Substitution with 3d magnetic transition elements in ABO 3 ferroelectric perovskite host media is widely utilized to produce relaxor ferroelectrics. Many resulting solid solutions exhibit magnetoelectric properties affected by concentration levels of the introduced magnetic ions. For conventional material preparation techniques such as firing of mechanically mixed oxides, incorporation is often limited by 5 mol% concentration level. Doping at higher concentrations requires introduction of other substituents to compensate charge within the unit cell to promote formation of the perovskite phase. In contrast, molecular mixing of precursor materials at the initial phase of preparation procedure offers an advantage of achieving higher incorporation levels of the 3d elements without additional charge-compensating ions. Presented in this thesis is a new sol-gel procedure utilized for high level incorporation of 3d magnetic ions into ferroelectric lead titanate. The technique was applied to produce PbTi1-xMnxO 3 solid solution, a perovskite system promising for high degree of magnetoelectric coupling. Concentration dependent studies were performed to characterize structural, thermal, ferroelectric and magnetic properties of the material. The solubility limit of Mn has been found to be 20 mol% and the material remains tetragonally distorted. X-ray Absorption Spectroscopy confirms that local structural environment of Mn, Ti, and Pb is consistent with tetragonal symmetry of the unit cell. Increase in Mn concentration leads to reduction in melting point, broadening of the ferroelectric transition, reduction of the transition temperature and increase in dielectric constant of the material. At the solubility limit the system was found to be ferromagnetic below 50 K.

  20. Lead poisoning in six captive avian species

    Science.gov (United States)

    Beyer, W.N.; Spann, J.W.; Sileo, L.; Franson, J.C.

    1988-01-01

    Red-winged blackbirds (Agelaius phoeniceus), brown-headed cowbirds (Molothrus ater), common grackles (Quiscalus quiscula), mallards (Anas platyrhynchos), northern bobwhites (Colinus virginianus), and eastern screech-owls (Otus asio) were poisoned with a concentration of lead (Pb) acetate in the diet which was increased by 60% each week until half of the birds in each treatment group died; surviving birds and all control birds except screech-owls were then killed by euthanasia. An additional group of mallards was poisoned with Pb shot. The gizzards of mallards poisoned either way usually were stained with bile; some of these birds also had proventricular impaction. Most poisoned birds of the other species were emaciated but lacked other gross lesions caused by Pb poisoning. In birds other than mallards, Pb poisoning could not be diagnosed without histological or hematological examinations or analysis of tissues. Poisoned birds of all six species could be reliably separated from control birds by an increase in the protoporphyrin concentrations in the blood and by a decrease in the activity of delta-aminoievulinic acid dehydratase (ALAD) in red blood cells. Hepatic iron (Fe) concentrations varied so much among individual birds that even though median hepatic Fe concentrations increased in poisoned birds, hepatic Fe concentrations were not useful in identifying poisoned birds. Renal intranuclear inclusion bodies occurred in 83% of all birds dying from Pb poisoning. Nephrosis, myocardial necrosis, and arterial fibrinoid necrosis were occasionally present. Median hepatic Pb concentrations varied from 20 ppm (wet wt) in male red-winged blackbirds to III ppm in female northern bobwhites. Median renal Pb concentrations varied from 22 ppm in red-winged blackbirds to 190 ppm in female northern bobwhites. Hepatic and renal Pb concentrations varied substantially among birds within each species. Median hepatic and renal Pb concentrations of birds that died were not statistically

  1. Peripheral blood signatures of lead exposure.

    Directory of Open Access Journals (Sweden)

    Heather G LaBreche

    Full Text Available BACKGROUND: Current evidence indicates that even low-level lead (Pb exposure can have detrimental effects, especially in children. We tested the hypothesis that Pb exposure alters gene expression patterns in peripheral blood cells and that these changes reflect dose-specific alterations in the activity of particular pathways. METHODOLOGY/PRINCIPAL FINDING: Using Affymetrix Mouse Genome 430 2.0 arrays, we examined gene expression changes in the peripheral blood of female Balb/c mice following exposure to per os lead acetate trihydrate or plain drinking water for two weeks and after a two-week recovery period. Data sets were RMA-normalized and dose-specific signatures were generated using established methods of supervised classification and binary regression. Pathway activity was analyzed using the ScoreSignatures module from GenePattern. CONCLUSIONS/SIGNIFICANCE: The low-level Pb signature was 93% sensitive and 100% specific in classifying samples a leave-one-out crossvalidation. The high-level Pb signature demonstrated 100% sensitivity and specificity in the leave-one-out crossvalidation. These two signatures exhibited dose-specificity in their ability to predict Pb exposure and had little overlap in terms of constituent genes. The signatures also seemed to reflect current levels of Pb exposure rather than past exposure. Finally, the two doses showed differential activation of cellular pathways. Low-level Pb exposure increased activity of the interferon-gamma pathway, whereas high-level Pb exposure increased activity of the E2F1 pathway.

  2. 77 FR 16796 - Lead Requirements for Lead-Based Paint Activities in Target Housing and Child-Occupied Facilities...

    Science.gov (United States)

    2012-03-22

    ... AGENCY 40 CFR Part 745 Lead Requirements for Lead-Based Paint Activities in Target Housing and Child... requirements, training program accreditation requirements, and work practice standards for lead-based paint... the Arkansas lead-based paint program and passed a new statute establishing a State lead-based...

  3. Research of Toxic Mechanism on Anaerobic Digestion by Lead

    Institute of Scientific and Technical Information of China (English)

    Han Jianhong; Wang Zhe; Zhang Lianke; Han Jintao

    2008-01-01

    The paper analyzes the influence of lead toxicity by anaerobic granule sludge inhibition and recovering experiments.The result shows that there are different inhibition types at differ ent lead contents.Higher lead content leads to more inhibition granular sludge,and at the same time,the time of gas recovery is different.Lower lead content per microorganism results in sooner sludge recovery.Microorganisms have a good ability to resist lead toxicity.

  4. Antibiotic impregnated catheter coverage of deep brain stimulation leads facilitates lead preservation after hardware infection.

    Science.gov (United States)

    Dlouhy, Brian J; Reddy, Ambur; Dahdaleh, Nader S; Greenlee, Jeremy D W

    2012-10-01

    Deep brain stimulation (DBS) has become a reliable and effective treatment for many disorders. However, the risk of long-term hardware-related complications is notable, and most concerning is hardware-related infections. Given the risk of hardware removal in the setting of infection, we retrospectively examined the implementation of a novel technique using antibiotic covered catheter protection of DBS leads after infection. The effect on hardware salvage and ease of reimplantation of the DBS extension and implantable pulse generator (IPG) was examined. A total of nine (9%) out of 100 DBS patients met the inclusion criteria with 11 DBS hardware-related infections at either the frontal, parietal, or IPG sites, from June 2003 to November 2010, at our institution. Subsequent to the initial patient in the series, a total of eight patients had placement of a short segment (approx. 4 cm long) of antibiotic impregnated catheter (Bactiseal, Codman, Johnson & Johnson, Raynham, MA, USA) over the distal end of the DBS leads at the parietal incision. Seven of these eight patients presented with pus and deep tissue infections around the hardware at either the frontal, parietal, or chest incisions. In seven of these eight patients (87.5%) we were able to protect and salvage their DBS leads without need for removal. In conclusion, this novel technique provides a simple reimplantation operation, with a decreased risk of DBS lead damage. It may improve the preservation of DBS leads when hardware infection occurs, is inexpensive, and confers no additional risks to patients.

  5. [Use of urine lead level as an exposure indicator and its relationship to blood lead].

    Science.gov (United States)

    Moreira, Maria de Fátima Ramos; Neves, Eduardo Borba

    2008-09-01

    The aim of this work was to verify whether there are statistically significant correlation between the concentrations of lead in blood (Pb-B) and urine (Pb-U). Electrothermal atomic absorption spectrometry was used in the determination of lead concentration in biological material. Venous blood and spot urine were collected from workers occupationally exposed (95), adults (130) and children up to 15 years old (22) environmentally exposed. After a test showing significant differences between Pb-U and the three categories previously determined, cutting points for Pb-U were established to predict Pb-B values by the ROC curve. Thus, it is expected that Pb-B is lower than 10 microg.dL-(1) with Pb-U up to 0.55 microg.dL-(1), whereas lead levels in blood below 27.6 microg.dL-(1) are expected when the amount of the metal in urine is lower than 2.05 microg.dL-(1). So, urine can be used to replace blood for the assessment of the occupational exposure to lead. However, caution is advised in the case of environmental exposure, since urinary lead should be used just as an estimation of the metal content in blood.

  6. Lead shot poisoning of a Pacific loon in Alaska

    Science.gov (United States)

    Wilson, H.M.; Oyen, J.L.; Sileo, L.

    2004-01-01

    Lead poisoning, associated with ingestion of spent lead shot, was diagnosed in an adult female Pacific loon (Gavia pacifica) observed with partial paralysis on 13 June 2002 and found dead on 16 June 2002 on Kigigak Island, Yukon Delta National Wildlife Refuge, western Alaska, USA. A necropsy revealed three pellets of ingested lead shot in the loona??s gizzard and a lead liver concentration of 31 ppm wet weight, which was consistent with metallic lead poisoning. This is the first report of lead poisoning in a Pacific loon and is the only account of lead toxicosis associated with ingestion of lead shot in any loon species breeding in Alaska.

  7. The Yugoslavia Prospective Lead Study: contributions of prenatal and postnatal lead exposure to early intelligence.

    Science.gov (United States)

    Wasserman, G A; Liu, X; Popovac, D; Factor-Litvak, P; Kline, J; Waternaux, C; LoIacono, N; Graziano, J H

    2000-01-01

    To investigate associations between the timing of lead (Pb) exposure on early intelligence, we examined the results of psychometric evaluations at ages 3, 4, 5, and 7 years, from 442 children whose mothers were recruited during pregnancy from a smelter town and a non-lead-exposed town in Yugoslavia. We compared the relative contribution of prenatal blood lead (BPb) with that of relative increases in BPb in either the early (0-2 years) or the later (from 2 years on) postnatal period to child intelligence measured longitudinally at ages 3 and 4 (McCarthy GCI), 5 (Wechsler Preschool and Primary Scale of Intelligence-Revised, WPPSI-R IQ), and 7 (Wechsler Intelligence Scale for Children-version III, WISC-III IQ), controlling for: Home Observation for Measurement of the Environment (HOME) quality; maternal age, intelligence, education, and ethnicity; and birthweight and gender. Elevations in both prenatal and postnatal BPb were associated with small decrements in young children's intelligence.

  8. Primary Prevention of Lead Exposure—Blood Lead Results at Age Two Years

    Directory of Open Access Journals (Sweden)

    Tine Hansen-Turton

    2012-04-01

    Full Text Available Objectives: The Philadelphia Lead Safe Homes (LSH Study was designed to evaluate whether educational and environmental interventions in the first year of life for families of newborns increased knowledge of lead exposure prevention and were associated with less elevation of blood lead levels (BLLs for these children, when compared to children receiving standard care. Methods: The current study performed descriptive statistics on the second-year BLL data for both groups and compared these using chi-square tests for proportions and unpaired t-tests for means. Results: A BLL result was found for 159 (50.6% of the 314 LSH cohort children and 331 (52.7% of the 628 control children (p = 0.1. Mean and standard deviation for age at draw was 23.8 (3.4 months versus 23.6 (3.1 months (P = 0.6. Geometric mean BLLs were 3.7 versus 3.5 µg/dL (P = 0.4. The percentages of the cohort group with a BLL of ≥20, ≥10 and ≥5 μg/dL, respectively, were 0.6%, 5% and 30%; for the controls 1.2%, 6.6%, and 25%. These percentages were not significantly different between groups. Conclusion: A comparison of geometric mean BLLs and percentages above several BLL cut points drawn at age two years in a group of urban newborns benefitting from study interventions versus a group of similar urban children did not yield statistically significant differences. Both groups had relatively lower lead levels when compared to historical cohort groups, which may reflect a continuing downward trend in BLLs in U.S. children. The interventions did result in benefits to the families such as an increase in parental knowledge about lead exposure prevention and in-home wet cleaning activity, and a decrease in lead dust levels in study homes.

  9. Factors affecting lead release in sodium silicate-treated partial lead service line replacements.

    Science.gov (United States)

    Zhou, Emily; Payne, Sarah Jane O; Hofmann, Ron; Andrews, Robert C

    2015-01-01

    Water quality parameters affecting sodium silicate performance in partial lead service line replacements were examined using a fractional factorial experimental design and static pipe systems. An external copper wire was used to create a galvanic connection between a former lead service line and a new copper pipe. The pipe systems were filled with lab prepared water made to mimic real water quality. Water was changed on a three times per week basis. A 2(4-1) fractional factorial design was used to evaluate the impact of alkalinity (15 mg L(-1) or 250 mg L(-1) as CaCO3), nitrate (1 mg L(-1) or 7 mg L(-1) as N), natural organic matter (1 mg L(-1) or 7 mg L(-1) as dissolved organic carbon), and disinfectant type (1 mg L(-1) chlorine or 3 mg L(-1) monochloramine), resulting in eight treatment conditions. Fractional factorial analysis revealed that alkalinity, natural organic matter and monochloramine had a significant positive effect on galvanic current. Natural organic matter and monochloramine also had a significant positive effect with respect to both total and dissolved lead release. For the treatment conditions examined, 67-98% of the lead released through galvanic currents was stored as corrosion scales and predominantly comprised of particulate lead (96.1-99.9%) for all eight treatments. The use of monochloramine and the presence of natural organic matter (7 mg L(-1)) were not favourable for corrosion control in sodium silicate-treated partial lead service line replacements, although further studies would be required to characterize optimal water quality parameters for specific water quality types. For utilities operating with sodium silicate as a corrosion inhibitor, this work offers further evidence regarding the consideration of chlorine as a secondary disinfectant instead of monochloramine, as well as the value of controlling natural organic matter in distributed water.

  10. Formation of lead-aluminate ceramics: Reaction mechanisms in immobilizing the simulated lead sludge.

    Science.gov (United States)

    Lu, Xingwen; Shih, Kaimin

    2015-11-01

    We investigated a strategy of blending lead-laden sludge and an aluminum-rich precursor to reduce the release of hazardous lead from the stabilized end products. To quantify lead transformation and determine its incorporation behavior, PbO was used to simulate the lead-laden sludge fired with γ-Al2O3 by Pb/Al molar ratios of 1/2 and 1/12 at 600-1000 °C for 0.25-10 h. The sintered products were identified and quantified using Rietveld refinement analysis of X-ray diffraction data from the products generated under different conditions. The results indicated that the different crystallochemical incorporations of hazardous lead occurred through the formation of PbAl2O4 and PbAl12O19 in systems with Pb/Al ratios of 1/2 and 1/12, respectively. PbAl2O4 was observed as the only product phase at temperature of 950 °C for 3h heating in Pb/Al of 1/2 system. For Pb/Al of 1/12 system, significant growth of the PbAl12O19 phase clearly occurred at 1000 °C for 3 h sintering. Different product microstructures were found in the sintered products between the systems with the Pb/Al ratios 1/2 and 1/12. The leaching performances of the PbO, Pb9Al8O21, PbAl2O4 and PbAl12O19 phases were compared using a constant pH 4.9 leaching test over 92 h. The leachability data indicated that the incorporation of lead into PbAl12O19 crystal is a preferred stabilization mechanism in aluminate-ceramics.

  11. Baryon and antibaryon production in lead-lead collisions at 158 A GeV/c

    Science.gov (United States)

    Newmass (NA52) Collaboration; Ambrosini, G.; Arsenescu, R.; Baglin, C.; Beringer, J.; Bohm, C.; Borer, K.; Bussière, A.; Dittus, F.; Elsener, K.; Frei, D.; Gorodetzky, Ph.; Guillaud, J. P.; Hess, P.; Hugentobler, E.; Kabana, S.; Klingenberg, R.; Lindén, T.; Lohmann, K. D.; Mommsen, R.; Moser, U.; Pal, T.; Pretzl, K.; Schacher, J.; Selldén, B.; Stoffel, F.; Tuominiemi, J.; Weber, M.; Zhang, Q. P.

    1998-01-01

    We report on baryon and antibaryon as well as K+ and K- production cross sections measured in lead-lead collisions at 158 GeV/c per nucleon. The presented data were taken at zero degree production angle with a minimum bias trigger. The measurements covered a wide range of rapidity 1.4

  12. Health hazards by lead exposure: evaluation using ASV and XRF.

    Science.gov (United States)

    Herman, D'Souza Sunil; Geraldine, Menezes; Scott, Clark C; Venkatesh, Thuppil

    2006-07-01

    Globally, of many toxic heavy metals, lead is the most widely used for various purposes, resulting in a variety of health hazards due to environmental contamination. Lead in the workplace enters the workers through inhalation of lead-contaminated air, by ingestion, and sometimes through dermal exposure. Furthermore, exposure outside the workplace can occur from inhalation of lead-contaminated air, ingestion of lead-contaminated dust and soil, consumption of lead polluted water, lead adulterated food and lead supplemented medicine. In the present study, an evaluation of blood lead was carried out with the aid of a 3010 B lead analyser, based on the principle of anodic stripping voltametry (ASV), and environmental lead in paint, soil and dust samples by a field portable X-ray fluorescence (XRF) analyser. This revealed a high incidence of lead toxicity in most of the lead-based industrial workers in the four facilities tested in India and high levels of lead in the environmental samples. Developed countries have complied with the global standards for regulating environmental lead poisoning in the workplace, eliminating to some degree excessive exposure to lead. A developing country, such as India, can tackle this problem by implementing national and international policies. The US Occupational Safety and Health Administration (OSHA) and Environmental Protection Agency (EPA) regulations, which are of prime importance, or similar regulations, can be adapted for use in India and implemented to minimize lead exposure and to reduce the resultant health hazards.

  13. Lead shot contribution to blood lead of First Nations people: The use of lead isotopes to identify the source of exposure

    Energy Technology Data Exchange (ETDEWEB)

    Tsuji, Leonard J.S. [Department of Environment and Resource Studies, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada)], E-mail: ljtsuji@fes.uwaterloo.ca; Wainman, Bruce C. [Faculty of Health Sciences, McMaster University, Hamilton, Ontario, L8N 3Z5 (Canada); Martin, Ian D. [Department of Environment and Resource Studies, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Sutherland, Celine [Attawapiskat First Nation Health Services, Attawapiskat, Ontario, P0L 1A0 (Canada); Weber, Jean-Philippe; Dumas, Pierre [Centre de toxicologie, Institut national de sante publique du Quebec, Quebec City, Quebec, G1V 5B3 (Canada); Nieboer, Evert [Faculty of Health Sciences, McMaster University, Hamilton, Ontario, L8N 3Z5 (Canada); Institute of Community Medicine, University of Tromso, Tromso N-9037 (Norway)

    2008-11-01

    Although lead isotope ratios have been used to identify lead ammunition (lead shotshell pellets and bullets) as a source of exposure for First Nations people of Canada, the actual source of lead exposure needs to be further clarified. Whole blood samples for First Nations people of Ontario, Canada, were collected from participants prior to the traditional spring harvest of water birds, as well as post-harvest. Blood-lead levels and stable lead isotope ratios prior to, and after the harvest were determined by ICP-MS. Data were analyzed by paired t-tests and Wilcoxon Signed-Ranks tests. All participants consumed water birds harvested with lead shotshell during the period of study. For the group excluding six males who were potentially exposed to other sources of lead (as revealed through a questionnaire), paired t-tests and Wilcoxon Signed-Ranks tests showed consistent results: significant (p < 0.05) increases in blood-lead concentrations and blood levels of {sup 206}Pb/{sup 204}Pb and {sup 206}Pb/{sup 207}Pb towards the mean values we previously reported for lead shotshell pellets; and a significant decrease in {sup 208}Pb/{sup 206}Pb values towards the mean for lead shotshell pellets. However, when we categorized the group further into a group that did not use firearms and did not eat any other traditional foods harvested with lead ammunition other than waterfowl, our predictions for {sup 206}Pb/{sup 204}Pb, {sup 206}Pb/{sup 207}Pb and {sup 208}Pb/{sup 206}Pb hold true, but there was not a significant increase in blood-lead level after the hunt. It appears that the activity of hunting (i.e., use of a shotgun) was also an important route of lead exposure. The banning of lead shotshell for all game hunting would eliminate a source of environmental lead for all people who use firearms and/or eat wild game.

  14. Coauthorship trends in the leading radiological journals.

    Science.gov (United States)

    Mussurakis, S

    1993-07-01

    Coauthorship trends have received limited attention in radiology. This paper examines the author inflation phenomenon in 12 leading radiological peer-reviewed journals and seeks explanations for the rise in multiple authorship. MEDLINE was searched from 1966 through 1991, and the indexed scientific material (67,758 articles) of the eligible core journals was analysed. During this 26-year period the average number of authors per original article (including case reports) doubled, increasing from 2.2 in 1966 to 4.4 in 1991. The linear regression model fitting the data was strongly significant, although since the late 1980s the rate of the coauthorship rise started to decrease. There was considerable variation in coauthorship patterns between journals. Other factors, such as the contributors' country, were also noted to influence coauthorship. The increasing complexity of radiological research explains in part the rise in multiple-author papers, but the main cause must undoubtedly be the excessive pressure to publish. Among the topics discussed are the incentives that stimulate radiologists to write, the dynamics of coauthorship, and the proposals made to standardize the requirements for authorship and to shift the emphasis from quantity of publication to quality.

  15. Antifilarial Lead Molecules Isolated from Trachyspermum ammi

    Directory of Open Access Journals (Sweden)

    Kalyanasundaram Muthuswamy

    2008-09-01

    Full Text Available Lymphatic filariasis is caused by infection with the parasitic filarial nematodes Wuchereria bancrofti, Brugia malayi and B. timori, transmitted by mosquitoes. The lack of an adulticidal drug poses a challenge to filariasis elimination, hence it is essential to develop an effective antifilarial drug which could either kill or permanently sterilize the adult worms. In the reported work the in vitro activity of a methanolic extract of fruits of Trachyspermum ammi (Apiaceae against adult bovine filarial Setaria digitata worms has been investigated. A bioassay-guided fractionation was carried out by subjecting the crude extract to flash chromatography. HPLC analysis was done for the crude extract and active fraction. The crude extract and the active fraction showed significant activity against the adult S. digitata by both a worm motility and MTT [3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide] reduction assays. The isolated active principle was chemically characterized by IR, 1H-NMR and MS analysis and identified as a phenolic monoterpene. It was screened for in vivo antifilarial activity against the human filarial worm B. malayi in Mastomys coucha, showing macrofilaricidal activity and female worm sterility in vivo against B. malayi. The findings thus provide a new lead for development of a macrofilaricidal drug from natural products

  16. Electrorheology leads to healthier and tastier chocolate.

    Science.gov (United States)

    Tao, Rongjia; Tang, Hong; Tawhid-Al-Islam, Kazi; Du, Enpeng; Kim, Jeongyoo

    2016-07-05

    Chocolate is one of the most popular food types and flavors in the world. Unfortunately, at present, chocolate products contain too much fat, leading to obesity. Although this issue was called into attention decades ago, no actual solution was found. To bypass this critical outstanding problem, two manufacturers introduced some low-calorie fats to substitute for cocoa butter. Somehow, their products are not allowed in most countries. Here we show that this issue is deeply related to the basic science of soft matter, especially to the viscosity of liquid suspension and maximally random jammed (MRJ) density. When the concentration of cocoa solid is high, close to the MRJ density, removing a small amount of fat will jam the chocolate flow. Applying unconventional electrorheology to liquid chocolate with applied field in the flow direction, we aggregate the cocoa particles into prolate spheroids in micrometers. This microstructure change breaks the rotational symmetry, reduces liquid chocolate's viscosity along the flow direction, and increases its MRJ density significantly. Hence the fat level in chocolate can be effectively reduced. We are expecting a new class of healthier and tastier chocolate soon.

  17. Lead effects on postural balance of children

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, A.; Shukla, R.; Bornschein, R.L.; Dietrich, K.N. (Univ. of Cincinnati, OH (USA)); Keith, R. (Univ. of Cincinnati Medical Center, OH (USA))

    1990-11-01

    The postural sway responses of 63 children with a mean age of 5.74 years were quantified with a Force Platform technique. The average maximum (max) blood lead (PbB) of these children during the first 5 years of life was 20.7 {mu}g/dL (range 9.2 to 32.5). The backward stepwise regression analysis for sway area response during the eyes-closed, no-foam test with all the covariates and confounders and the PbB parameters showed a significant relationship with peak or max PbB during the second year of life. These results are consistent with their previous study with a smaller group of children. The data have been analyzed to provide some insight into the role of various afferents for the maintenance of postural balance. The results suggests a hypothesis that if the max PbB had caused some level of impairment in the functional capacities or interconnectivity of the vestibular and/or proprioception systems at 2 years of age, then it is reasonable to assume that the redundancy in the postural afferent systems would naturally adapt to rely more on the remaining intact afferent system (in this case, vision).

  18. Designing Lead Optimisation of MMP-12 Inhibitors

    Directory of Open Access Journals (Sweden)

    Matteo Borrotti

    2014-01-01

    Full Text Available The design of new molecules with desired properties is in general a very difficult problem, involving heavy experimentation with high investment of resources and possible negative impact on the environment. The standard approach consists of iteration among formulation, synthesis, and testing cycles, which is a very long and laborious process. In this paper we address the so-called lead optimisation process by developing a new strategy to design experiments and modelling data, namely, the evolutionary model-based design for optimisation (EDO. This approach is developed on a very small set of experimental points, which change in relation to the response of the experimentation according to the principle of evolution and insights gained through statistical models. This new procedure is validated on a data set provided as test environment by Pickett et al. (2011, and the results are analysed and compared to the genetic algorithm optimisation (GAO as a benchmark. The very good performance of the EDO approach is shown in its capacity to uncover the optimum value using a very limited set of experimental points, avoiding unnecessary experimentation.

  19. Valve-regulated lead-acid batteries

    Science.gov (United States)

    Berndt, D.

    Valve-regulated lead-acid (VRLA) batteries with gelled electrolyte appeared as a niche market during the 1950s. During the 1970s, when glass-fiber felts became available as a further method to immobilize the electrolyte, the market for VRLA batteries expanded rapidly. The immobilized electrolyte offers a number of obvious advantages including the internal oxygen cycle which accommodates the overcharging current without chemical change within the cell. It also suppresses acid stratification and thus opens new fields of application. VRLA batteries, however, cannot be made completely sealed, but require a valve for gas escape, since hydrogen evolution and grid corrosion are unavoidable secondary reactions. These reactions result in water loss, and also must be balanced in order to ensure proper charging of both electrodes. Both secondary reactions have significant activation energies, and can reduce the service life of VRLA batteries, operated at elevated temperature. This effect can be aggravated by the comparatively high heat generation caused by the internal oxygen cycle during overcharging. Temperature control of VRLA batteries, therefore, is important in many applications.

  20. Phosphate removal by lead-exhausted bioadsorbents simultaneously achieving lead stabilization.

    Science.gov (United States)

    Wan, Shunli; Wu, Jiayu; He, Feng; Zhou, Shanshan; Wang, Rui; Gao, Bin; Chen, Jianmeng

    2017-02-01

    Low-cost adsorbents have been continuously developed for heavy metal removal, but little information is available concerning the follow-up treatment of the toxic metal-laden adsorbents. In this study, an optional strategy was provided for the further treatment of heavy metal-impregnated low-cost adsorbents through employing them for phosphate retention. The enhancement of phosphate adsorption by the sorbed lead was first validated using several types of raw or modified waste biomass. Tea waste-supported hydrated manganese dioxide (HMO-TW) with the highest Pb sorption capability was then chosen to systematically evaluate phosphate retention. Phosphate adsorption onto lead-laden HMO-TW (HMO-TW(Pb)) was pH-insensitive with only slight decline at pH > 8.5, and was barely affected by competing anions owing to the specific surface precipitation mechanism. Moreover, no signs of lead leakage from HMO-TW(Pb) were observed during phosphate adsorption at a wide pH range (4.2-11.3) and high ion strength (0-250 mg L(-1) NaNO3). The lead on HMO-TW(Pb) was greatly stabilized through phosphate retention, which also reduced the environmental risks of their following treatment such as solidification and landfill. Additionally, the phosphate adsorption onto HMO-TW(Pb) was quick (with equilibrium time phosphate from water.

  1. Leading Charters: How Charter School Administrators Define Their Roles and Their Ability to Lead

    Science.gov (United States)

    Carpenter, Dick Michael, II; Peak, Charity

    2013-01-01

    Charter schools have been studied from numerous perspectives. One topic that remains under-researched, however, is charter school leadership. Therefore, we examine how charter administrators define their leadership roles and their ability to lead. Results indicate that charter principals see three primary functions in their leadership--building…

  2. 90° Neutron emission from high energy protons and lead ions on a thin lead target

    Science.gov (United States)

    Agosteo, S.; Birattari, C.; Foglio Para, A.; Mitaroff, A.; Silari, M.; Ulrici, L.

    2002-01-01

    The neutron emission from a relatively thin lead target bombarded by beams of high energy protons/pions and lead ions was measured at CERN in one of the secondary beam lines of the Super Proton Synchrotron for radiation protection and shielding calculations. Measurements were performed with three different beams: 208Pb 82+ lead ions at 40 GeV/ c per nucleon and 158 GeV/ c per nucleon, and 40 GeV/ c mixed protons/pions. The neutron yield and spectral fluence per incident ion on target were measured at 90° with respect to beam direction. Monte-Carlo simulations with the FLUKA code were performed for the case of protons and pions and the results found in good agreement with the experimental data. A comparison between simulations and experiment for protons, pions and lead ions have shown that—for such high energy heavy ion beams—a reasonable estimate can be carried out by scaling the result of a Monte-Carlo calculation for protons by the projectile mass number to the power of 0.80-0.84.

  3. Cumulant generating function formula of heat transfer in ballistic systems with lead-lead coupling

    Science.gov (United States)

    Li, Huanan; Agarwalla, Bijay Kumar; Wang, Jian-Sheng

    2012-10-01

    Based on a two-time observation protocol, we consider heat transfer in a given time interval tM in a lead-junction-lead system taking coupling between the leads into account. In view of the two-time observation, consistency conditions are carefully verified in our specific family of quantum histories. Furthermore, its implication is briefly explored. Then using the nonequilibrium Green's function method, we obtain an exact formula for the cumulant generating function for heat transfer between the two leads, valid in both transient and steady-state regimes. Also, a compact formula for the cumulant generating function in the long-time limit is derived, for which the Gallavotti-Cohen fluctuation symmetry is explicitly verified. In addition, we briefly discuss Di Ventra's repartitioning trick regarding whether the repartitioning procedure of the total Hamiltonian affects the nonequilibrium steady-state current fluctuation. All kinds of properties of nonequilibrium current fluctuations, such as the fluctuation theorem in different time regimes, could be readily given according to these exact formulas.

  4. Lead exposure in Canada geese of the Eastern Prairie Population

    Science.gov (United States)

    DeStefano, S.; Brand, C.J.; Rusch, D.H.; Finley, Daniel L.; Gillespie, M.M.

    1991-01-01

    We monitored lead exposure in Eastern Prairie Population Canada geese during summer-winter, 1986-1987 and 1987-1988 at 5 areas. Blood lead concentrations in geese trapped during summer at Cape Churchill Manitoba were below levels indicative of recent lead exposure (0.18 ppm). Geese exposed to lead (≥0.18 ppm blood lead) increased to 7.6% at Oak Hammock Wildlife Management Area (WMA), southern Manitoba, where lead shot was still in use, and to 10.0% at Roseau River WMA, northern Minnesota, when fall-staging geese were close to a source of lead shot in Manitoba. Proportion of birds exposed to lead dropped to <2% at Lac Qui Parle WMA, Minnesota, a steel shot zone since 1980. On the wintering grounds at Swan Lake National Wildlife Refuge in Missouri, 4.9% of all geese showed exposure to lead before the hunting season. Lead exposure rose to 10.0% after hunting ended and then decreased to 5.2% in late winter. Incidence of lead shot in gizzards and concentrations of lead in livers supported blood assay data. Soil samples indicated that lead shot continues to be available to geese at Swan Lake, even though the area was established as a non-toxic shot zone in 1978. Steel shot zones have reduced lead exposure in the Eastern Prairie Population, but lead shot persists in the environment and continues to account for lead exposure and mortality in Eastern Prairie Population Canada geese.

  5. 40 CFR 52.1375 - Control strategy: Lead.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Lead. 52.1375 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Montana § 52.1375 Control strategy: Lead. Determination—EPA has determined that the East Helena Lead nonattainment area has attained the lead...

  6. 24 CFR 35.135 - Use of paint containing lead.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Use of paint containing lead. 35... Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES General Lead-Based Paint Requirements and Definitions for All Programs. § 35.135 Use of paint containing lead....

  7. Design of a magnetic lead screw for wave energy conversion

    DEFF Research Database (Denmark)

    Holm, Rasmus Koldborg; Berg, Nick Ilsø; Rasmussen, Peter Omand

    2012-01-01

    This paper deals with the development of a magnetic lead screw (MLS) for wave energy conversion. Initially, a brief state-of-the-art regarding linear PM generators and magnetic lead screws is given, leading to an introduction of the magnetic lead screw and a presentation of the results from...

  8. Lead shot contribution to blood lead of First Nations people: the use of lead isotopes to identify the source of exposure.

    Science.gov (United States)

    Tsuji, Leonard J S; Wainman, Bruce C; Martin, Ian D; Sutherland, Celine; Weber, Jean-Philippe; Dumas, Pierre; Nieboer, Evert

    2008-11-01

    Although lead isotope ratios have been used to identify lead ammunition (lead shotshell pellets and bullets) as a source of exposure for First Nations people of Canada, the actual source of lead exposure needs to be further clarified. Whole blood samples for First Nations people of Ontario, Canada, were collected from participants prior to the traditional spring harvest of water birds, as well as post-harvest. Blood-lead levels and stable lead isotope ratios prior to, and after the harvest were determined by ICP-MS. Data were analyzed by paired t-tests and Wilcoxon Signed-Ranks tests. All participants consumed water birds harvested with lead shotshell during the period of study. For the group excluding six males who were potentially exposed to other sources of lead (as revealed through a questionnaire), paired t-tests and Wilcoxon Signed-Ranks tests showed consistent results: significant (plead concentrations and blood levels of (206)Pb/(204)Pb and (206)Pb/(207)Pb towards the mean values we previously reported for lead shotshell pellets; and a significant decrease in (208)Pb/(206)Pb values towards the mean for lead shotshell pellets. However, when we categorized the group further into a group that did not use firearms and did not eat any other traditional foods harvested with lead ammunition other than waterfowl, our predictions for (206)Pb/(204)Pb, (206)Pb/(207)Pb and (208)Pb/(206)Pb hold true, but there was not a significant increase in blood-lead level after the hunt. It appears that the activity of hunting (i.e., use of a shotgun) was also an important route of lead exposure. The banning of lead shotshell for all game hunting would eliminate a source of environmental lead for all people who use firearms and/or eat wild game.

  9. Optimal lead time for dengue forecast.

    Directory of Open Access Journals (Sweden)

    Yien Ling Hii

    Full Text Available BACKGROUND: A dengue early warning system aims to prevent a dengue outbreak by providing an accurate prediction of a rise in dengue cases and sufficient time to allow timely decisions and preventive measures to be taken by local authorities. This study seeks to identify the optimal lead time for warning of dengue cases in Singapore given the duration required by a local authority to curb an outbreak. METHODOLOGY AND FINDINGS: We developed a Poisson regression model to analyze relative risks of dengue cases as functions of weekly mean temperature and cumulative rainfall with lag times of 1-5 months using spline functions. We examined the duration of vector control and cluster management in dengue clusters > = 10 cases from 2000 to 2010 and used the information as an indicative window of the time required to mitigate an outbreak. Finally, we assessed the gap between forecast and successful control to determine the optimal timing for issuing an early warning in the study area. Our findings show that increasing weekly mean temperature and cumulative rainfall precede risks of increasing dengue cases by 4-20 and 8-20 weeks, respectively. These lag times provided a forecast window of 1-5 months based on the observed weather data. Based on previous vector control operations, the time needed to curb dengue outbreaks ranged from 1-3 months with a median duration of 2 months. Thus, a dengue early warning forecast given 3 months ahead of the onset of a probable epidemic would give local authorities sufficient time to mitigate an outbreak. CONCLUSIONS: Optimal timing of a dengue forecast increases the functional value of an early warning system and enhances cost-effectiveness of vector control operations in response to forecasted risks. We emphasize the importance of considering the forecast-mitigation gaps in respective study areas when developing a dengue forecasting model.

  10. Recent Advances in the Clinical Management of Lead Poisoning.

    Directory of Open Access Journals (Sweden)

    Sina Kianoush

    2015-06-01

    Full Text Available Lead poisoning is a historic universal disease. Acute or chronic lead exposure may cause reversible or even permanent damages in human beings. Environmental lead exposure is a global health concern in children. Occupational lead poisoning is still a health issue, particularly in developing countries. During the last decades, new methods and medications have been advocated for the prevention and treatment of lead poisoning. This review deals mainly with recent developments in the management of lead poisoning. Sources of lead exposure are introduced, and methods for the primary prevention of lead poisoning are discussed. Details for the screening of adults and children are also explained to serve as a practical guideline for the secondary prevention. Standard chelation therapy in different groups and up-to-date less toxic new medications for the treatment of lead poisoning are finally discussed. Our published clinical research on the therapeutic effects of garlic tablets in mild to moderate occupational lead poisoning will also be discussed.

  11. Inherent variability in lead and copper collected during standardized sampling.

    Science.gov (United States)

    Masters, Sheldon; Parks, Jeffrey; Atassi, Amrou; Edwards, Marc A

    2016-03-01

    Variability in the concentration of lead and copper sampled at consumers' taps poses challenges to assessing consumer health threats and the effectiveness of corrosion control. To examine the minimum variability that is practically achievable, standardized rigs with three lead and copper containing plumbing materials (leaded brass, copper tube with lead solder, and a lead copper connection) were deployed at five utilities and sampled with regimented protocols. Variability represented by relative standard deviation (RSD) in lead release was high in all cases. The brass had the lowest variability in lead release (RSD = 31 %) followed by copper-solder (RSD = 49%) and lead-copper (RSD = 80%). This high inherent variability is due to semi-random detachment of particulate lead to water, and represents a modern reality of water lead problems that should be explicitly acknowledged and considered in all aspects of exposure, public education, and monitoring.

  12. Reductions in blood lead overestimate reductions in brain lead following repeated succimer regimens in a rodent model of childhood lead exposure.

    Science.gov (United States)

    Stangle, Diane E; Strawderman, Myla S; Smith, Donald; Kuypers, Mareike; Strupp, Barbara J

    2004-03-01

    Although many studies have demonstrated the efficacy of succimer chelation in reducing blood and brain lead levels, the relative efficacy of the drug in the two tissues is less well understood. This issue is important because blood lead levels after chelation are used clinically to estimate reductions in the brain, the most critical organ in considering lead-induced neurotoxicity. The present study was designed to further investigate this issue, using multiple chelation regimens. Long-Evans rats were exposed to one of three lead exposure regimens from birth until postnatal day 40, followed by treatment with succimer (one or two 3-week regimens) or vehicle. The results indicated that one succimer regimen was significantly superior to vehicle treatment in lowering lead levels in both blood and brain across the entire 8-week follow-up period. Similarly, a second succimer regimen offered significant additional benefit relative to one regimen for both blood and brain across the 4-week follow-up period. However, several findings revealed that succimer-induced reductions in brain lead lagged behind reductions in blood lead and were generally smaller in magnitude. Furthermore, a rebound was detected in blood, but not brain, lead levels after both succimer regimens. Given the results of this study, we urge caution in using blood lead as a surrogate for brain lead levels, particularly during and immediately after chelation treatment when reductions in blood lead levels overestimate reductions in brain lead levels. The present results suggest that, in clinical use, succimer treatment may need to extend beyond the point at which blood lead levels have dropped to an "acceptable" target value in order to effectively reduce brain lead levels and minimize neurotoxicity.

  13. The effect of lead content and surface roughness on wetting and spreading of low-lead and no-lead solders on copper-clad FR-4 laminates

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, J.O.; Roberts, J.L.; Davidson, R.N.; Yost, F.G.; Hosking, F.M.

    1997-02-01

    Environmental and health concerns pertaining to lead have encouraged research into low-lead alloys for electronic soldering. The development of solder alloys containing lower amounts of lead than Sn/Pb eutectic (37 wt.% lead), but possessing similar properties, is an industry-wide goal. To determine the wettability of low-lead solders, 21 alloys each of Sn/Ag and Sn/Cu eutectic (containing 0 to 10 wt.% lead and/or indium) were tested on as-received copper-clad FR-4. Contact angles for the alloys ranged from 12.5 to 38.9{degrees} and area of spread measurements ranged from 5.2 to 17.3 mm{sup 2} compared with 5 to 150 and {approximately}19 mm{sup 2}, respectively, for Sn/Pb eutectic. Alloys with 8 to 10 wt.% lead showed contact angles and areas of spread similar to Sn/Pb eutectic under similar conditions. The best results on the as-received substrates, compared to the Sn/Pb eutectic, were obtained from the Sn/Ag eutectic with 10 wt.% lead. The very low-lead (less than 10 wt.% lead) and lead-free alloys, however, failed to achieve the performance level of eutectic Sn/Pb solders. A desire to improve the spreading of very low-lead and lead-free solders provided the impetus for these efforts to produce {open_quotes}engineered{close_quotes} rough surfaces. In an attempt to improve the wettability and spreading behavior of very low-lead and lead-free alloys, the very low-lead and lead-free members of the Sn/Ag system were tested on roughened copper-clad FR-4. Every alloy in the test suite demonstrated improvement in area of spread on the roughened substrates. The best results on the roughened substrates, compared to the Sn/Pb eutectic, were obtained from the Sn/Ag eutectic with 8 wt.% lead. The effects of surface roughness on the wettability and flow behavior of solder alloys has provided insight into surface morphologies that lead to improved solderability.

  14. Adverse health effects of lead exposure on children and exploration to internal lead indicator

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Q.; Zhao, H.H. [Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030 (China); Chen, J.W.; Gu, K.D.; Zhang, Y.Z.; Zhu, Y.X.; Zhou, Y.K. [Minitry of Environmental Protection Key Lab of Environment, Wuhan 430030 (China); Ye, L.X., E-mail: yelx2004@163.com [Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030 (China)

    2009-11-15

    Our research on adverse effects of lead exposures on physical and neurobehavioral health of children aged 6-12 years in 4 villages, labeled as K, M, L, and X, in rural China, was reported in this article. Lead in blood (PbB), urine (PbU), hairs (PbH), and nails (PbN) were measured by graphite furnace atomic absorption spectrometry. Abbreviated Symptom Questionnaire of Conner's instruments and Revised Raven's Standard Progressive Matrices were applied to evaluate childhood attention deficit/hyperactivity disorders (ADHD) and intelligences. Geometric means (SD) of PbB, PbU, PbH and PbN concentrations were 71.2 {mu}g/L (1.56), 11.7 {mu}g/g (1.75), 12.5 {mu}g/g (2.82), and 25.3 {mu}g/g (2.79), respectively. 54 (17.0%) children had PbB levels of {>=} 100 {mu}g/L. Boys, the 6-10 years old, and living in village K were 2.11, 2.48, and 9.16 times, respectively, more likely to be poisoned by lead than girls, aged 11-12 years, and residing in X. 18 (5.7%) and 37 (11.7%) subjects had ADHD and mental retardations, respectively. Inverse relationships between intelligences and natural log transformed PbU and PbH levels were observed with respective odds ratios (95%CI) of 1.79 (1.00-3.22) and 1.46 (1.06-2.03) or 1.28 (1.04-1.58) and 1.73 (1.18-2.52) by binary or ordinal logistic regression modeling. ADHD prevalence was different by gender and age of subjects. PbU, PbH, and PbN related to PbB positively with respective correlation coefficients of 0.530, 0.477, and 0.181. Receiver operating characteristic (ROC) curves of the three measurements reveled areas under curves (AUCs) being 0.829, 0.758, and 0.687, respectively. In conclusion, children had moderate levels of lead exposures in this rural area. Intelligence declines were associated with internal lead levels among children. ROC analysis suggests PbU an internal lead indicator close to PbB.

  15. Distant hybridization leads to different ploidy fishes

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Distant hybridization makes it possible to transfer the genome of one species to another, which results in changes in phenotypes and genotypes of the progenies. This study shows that distant hybridization or the combination of this method with gynogenesis or androgenesis lead to different ploidy fishes with genetic variation, including fertile tetraploid hybrids, sterile triploid hybrids, fertile diploid hybrids, fertile diploid gynogenetic fish, and their derived progenies. The formations of the different ploidy fishes depend on the genetic relationship between the parents. In this study, several types of distant hybridization, including red crucian carp (Carassius auratus red var.) (2n=100, abbreviated as RCC) (♀)×common carp (Cyprinus carpio L.) (2n=100, abbreviated as CC) (♂), and RCC (2n=100) (♀)×blunt snout bream (Megalobrama amblycephala) (2n=48, abbreviated as BSB) (♂) are described. In the distant hybridization of RCC (♀)×CC (♂), bisexual fertile F3–F18 allotetraploid hybrids (4n=200, abbreviated as 4nAT) were formed. The diploid hybrid eggs and diploid sperm generated by the females and males of 4nAT developed into diploid gynogenetic hybrids and diploid androgenetic hybrids, respectively, by gynogenesis and androgenesis, without treatment for doubling the chromosome. Improved tetraploid hybrids and improved diploid fishes with genetic variation were derived from the gynogenetic hybrid line. The improved diploid fishes included the high-body RCC and high-body goldfish. The formation of the tetraploid hybrids was related to the occurrence of unreduced gametes generated from the diploid hybrids, which involved in premeiotic endoreduplication, endomitosis, or fusion of germ cells. The sterile triploid hybrids (3n=150) were produced on a large scale by crossing the males of tetraploid hybrids with females of diploid fish (2n=100). In another distant hybridization of RCC (♀)×BSB (♂), different ploidy fishes were obtained, including

  16. Distant hybridization leads to different ploidy fishes.

    Science.gov (United States)

    Liu, ShaoJun

    2010-04-01

    Distant hybridization makes it possible to transfer the genome of one species to another, which results in changes in phenotypes and genotypes of the progenies. This study shows that distant hybridization or the combination of this method with gynogenesis or androgenesis lead to different ploidy fishes with genetic variation, including fertile tetraploid hybrids, sterile triploid hybrids, fertile diploid hybrids, fertile diploid gynogenetic fish, and their derived progenies. The formations of the different ploidy fishes depend on the genetic relationship between the parents. In this study, several types of distant hybridization, including red crucian carp (Carassius auratus red var.) (2n=100, abbreviated as RCC) (female) x common carp (Cyprinus carpio L.) (2n=100, abbreviated as CC) (male), and RCC (2n=100) (female) x blunt snout bream (Megalobrama amblycephala) (2n=48, abbreviated as BSB) (male) are described. In the distant hybridization of RCC (female) x CC (male), bisexual fertile F(3)-F(18) allotetraploid hybrids (4n=200, abbreviated as 4nAT) were formed. The diploid hybrid eggs and diploid sperm generated by the females and males of 4nAT developed into diploid gynogenetic hybrids and diploid androgenetic hybrids, respectively, by gynogenesis and androgenesis, without treatment for doubling the chromosome. Improved tetraploid hybrids and improved diploid fishes with genetic variation were derived from the gynogenetic hybrid line. The improved diploid fishes included the high-body RCC and high-body goldfish. The formation of the tetraploid hybrids was related to the occurrence of unreduced gametes generated from the diploid hybrids, which involved in premeiotic endoreduplication, endomitosis, or fusion of germ cells. The sterile triploid hybrids (3n=150) were produced on a large scale by crossing the males of tetraploid hybrids with females of diploid fish (2n=100). In another distant hybridization of RCC (female) x BSB (male), different ploidy fishes were

  17. Antihelium-3 production in lead-lead collisions at 158 A GeV/c

    CERN Document Server

    Arsenescu, R; Beck, H P; Borer, K; Bussière, A; Elsener, K; Gorodetzky, P; Guillaud, J P; Kabana, S; Klingenberg, R; Lehmann, G; Lindén, T; Lohmann, K D; Mommsen, R K; Moser, U; Pretzl, K; Schacher, J; Spiwoks, R; Tuominiemi, J; Weber, M

    2003-01-01

    The NA-52 experiment measured particle and antiparticle yields at 0 deg production angle over a wide range in rapidity in lead-lead (Pb-Pb) collisions at 158 A GeV/c with a minimum bias trigger. Besides O(10 sup 6) antiprotons and O(10 sup 3) antideuterons a total of five antihelium-3 were found. The resulting invariant differential production cross sections at p sub t approx =0 GeV/c turn out to be E (d sup 3 sigma)/(dp sup 3) = (2.5 +- 1.8) x 10 sup - sup 7 bc sup 3 GeV sup - sup 2 at a rapidity of y = 3.4 in the laboratory system and (5.9 +- 3.4) x 10 sup - sup 8 bc sup 3 GeV sup - sup 2 at y = 4.0. The results are discussed in the framework of a simple coalescence model.

  18. Antihelium-3 production in lead-lead collisions at 158 A GeV/c

    Science.gov (United States)

    Arsenescu, R.; Baglin, C.; Beck, H. P.; Borer, K.; Bussière, A.; Elsener, K.; Gorodetzky, Ph; Guillaud, J. P.; Kabana, S.; Klingenberg, R.; Lehmann, G.; Lindén, T.; Lohmann, K. D.; Mommsen, R.; Moser, U.; Pretzl, K.; Schacher, J.; Spiwoks, R.; Tuominiemi, J.; Weber, M.

    2003-01-01

    The NA52 experiment measured particle and antiparticle yields at 0° production angle over a wide range in rapidity in lead-lead (Pb-Pb) collisions at 158 A GeV/c with a minimum bias trigger. Besides Script O(106) antiprotons (bar-p) and Script O(103) antideuterons (bar-d) a total of five antihelium-3 (overline-3He) were found. The resulting invariant differential overline-3He production cross sections at ptsimeq0 GeV/c turn out to be E (d3sigma)/(dp3) = (2.5 ± 1.8) × 10-7 bc3 GeV-2 at a rapidity of y = 3.4 in the laboratory system and (5.9 ± 3.4) × 10-8 bc3 GeV-2 at y = 4.0. The results are discussed in the framework of a simple coalescence model.

  19. Antihelium-3 production in lead-lead collisions at 158 A GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Arsenescu, R [Laboratory for High Energy Physics, University of Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Baglin, C [CNRS-IN2P3, LAPP Annecy, F-74941 Annecy-le-Vieux (France); Beck, H P [Laboratory for High Energy Physics, University of Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Borer, K [Laboratory for High Energy Physics, University of Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Bussiere, A [CNRS-IN2P3, LAPP Annecy, F-74941 Annecy-le-Vieux (France); Elsener, K [CERN, SL Division, CH-1211 Geneva (Switzerland); Gorodetzky, Ph [SPCC - College de France, 11 Place Marcellin Berthelod, 75005 Paris (France); Guillaud, J P [CNRS-IN2P3, LAPP Annecy, F-74941 Annecy-le-Vieux (France); Kabana, S [Laboratory for High Energy Physics, University of Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Klingenberg, R [Laboratory for High Energy Physics, University of Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Lehmann, G [Laboratory for High Energy Physics, University of Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Linden, T [Helsinki Insitute of Physics, PO Box 9, FIN-00014 Helsinki (Finland); Lohmann, K D [CERN, SL Division, CH-1211 Geneva (Switzerland); Mommsen, R [Laboratory for High Energy Physics, University of Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Moser, U [Laboratory for High Energy Physics, University of Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Pretzl, K [Laboratory for High Energy Physics, University of Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Schacher, J [Laboratory for High Energy Physics, University of Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Spiwoks, R [Laboratory for High Energy Physics, University of Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Tuominiemi, J [Helsinki Insitute of Physics, PO Box 9, FIN-00014 Helsinki (Finland); Weber, M [Laboratory for High Energy Physics, University of Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland)

    2003-01-01

    The NA-52 experiment measured particle and antiparticle yields at 0 deg production angle over a wide range in rapidity in lead-lead (Pb-Pb) collisions at 158 A GeV/c with a minimum bias trigger. Besides O(10{sup 6}) antiprotons and O(10{sup 3}) antideuterons a total of five antihelium-3 were found. The resulting invariant differential production cross sections at p{sub t}{approx_equal}0 GeV/c turn out to be E (d{sup 3}{sigma})/(dp{sup 3}) = (2.5 {+-} 1.8) x 10{sup -7} bc{sup 3} GeV{sup -2} at a rapidity of y = 3.4 in the laboratory system and (5.9 {+-} 3.4) x 10{sup -8} bc{sup 3} GeV{sup -2} at y = 4.0. The results are discussed in the framework of a simple coalescence mode000.

  20. Extrinsic Contribution and Instability Properties in Lead-Based and Lead-Free Piezoceramics

    Directory of Open Access Journals (Sweden)

    José Eduardo García

    2015-11-01

    Full Text Available Piezoceramic materials generally exhibit a notable instability of their functional properties when they work under real external conditions. This undesirable effect, known as nonlinear behavior, is mostly associated with the extrinsic contribution to material response. In this article, the role of the ferroelectric domain walls’ motion in the nonlinear response in the most workable lead-based and lead-free piezoceramics is reviewed. Initially, the extrinsic origin of the nonlinear response is discussed in terms of the temperature dependence of material response. The influence of the crystallographic phase and of the phase boundaries on the material response are then reviewed. Subsequently, the impact of the defects created by doping in order to control the extrinsic contribution is discussed as a way of tuning material properties. Finally, some aspects related to the grain-size effect on the nonlinear response of piezoceramics are surveyed.

  1. Erythrophagocytosis of Lead-Exposed Erythrocytes by Renal Tubular Cells: Possible Role in Lead-Induced Nephrotoxicity

    OpenAIRE

    Kwon, So-Youn; Bae, Ok-Nam; Noh, Ji-Yoon; Kim, Keunyoung; Kang, Seojin; Shin, Young-Jun; Lim, Kyung-Min; Chung, Jin-Ho

    2014-01-01

    Background: Nephrotoxicity associated with lead poisoning has been frequently reported in epidemiological studies, but the underlying mechanisms have not been fully described. Objectives: We examined the role of erythrocytes, one of the major lead reservoirs, in lead-associated nephrotoxicity. Methods and results: Co-incubation of lead-exposed human erythrocytes with HK-2 human renal proximal tubular cells resulted in renal tubular cytotoxicity, suggesting a role of erythrocytes in lead-induc...

  2. Fabrication and performance of a single-crystal lead magnesium niobate-lead titanate cylindrical hydrophone.

    Science.gov (United States)

    Brown, Jeremy A; Dunphy, Kevin; Leadbetter, Jeff R; Adamson, Robert B A; Beslin, Olivier

    2013-08-01

    The development of a piezoelectric hydrophone based on lead magnesium niobate-lead titanate [PbMg1/3Nb2/3O3-PbTiO3 (PMN-PT)] single-crystal piezoelectric as the hydrophone substrate is reported. Although PMN-PT can possess much higher piezoelectric sensitivity than traditional lead zirconate titanate (PZT) piezoelectrics, it is highly anisotropic and therefore there is a large gain in sensitivity only when the crystal structure is oriented in a specific direction. Because of this, simply replacing the PZT substrate with a PMN-PT cylinder is not an optimal solution because the crystal orientation does not uniformly align with the circumferential axis of the hydrophone. Therefore, a composite hydrophone that maintains the optimal crystal axis around the hydrophone circumference has been developed. An 11.3 mm diameter composite hydrophone cylinder was fabricated from a single cut PMN-PT rectangular plate. Solid end caps were applied to the cylinder and the sensitivity was directly compared with a solid PZT-5A cylindrical hydrophone of equal dimensions in a hydrophone test tank. The charge sensitivity showed a 9.1 dB improvement over the PZT hydrophone and the voltage sensitivity showed a 3.5 dB improvement. This was in good agreement with the expected theoretical improvements of 10.1 and 4.5 dB, respectively.

  3. QCD analysis and effective temperature of direct photons in lead-lead collisions at the LHC

    CERN Document Server

    Klasen, M; König, F; Wessels, J P

    2014-01-01

    We present a systematic theoretical analysis of the ALICE measurement of low-$p_T$ direct-photon production in central lead-lead collisions at the LHC with a centre-of-mass energy of $\\sqrt{s_{NN}}=2.76$ TeV. Using next-to-leading order of perturbative QCD, we compute the relative contributions to prompt-photon production from different initial and final states and the theoretical uncertainties coming from independent variations of the renormalisation and factorisation scales, the nuclear parton densities and the fragmentation functions. Based on different fits to the unsubtracted and prompt-photon subtracted ALICE data, we consistently find an exponential, possibly thermal, photon spectrum from the quark-gluon plasma (or hot medium) with slope $T=304\\pm 58$ MeV and $309\\pm64$ MeV at $p_T\\in[0.8;2.2]$ GeV and $p_T\\in[1.5;3.5]$ GeV as well as a power-law ($p_T^{-4}$) behavior for $p_T>4$ GeV as predicted by QCD hard scattering.

  4. A lead isotopic assessment of tree bark as a biomonitor of contemporary atmospheric lead

    Energy Technology Data Exchange (ETDEWEB)

    Patrick, Gavin J. [School of GeoSciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3JN, Scotland (United Kingdom); Farmer, John G. [School of GeoSciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3JN, Scotland (United Kingdom)], E-mail: J.G.Farmer@ed.ac.uk

    2007-12-15

    The outermost bark layer of trees, predominantly Scots pine (Pinus sylvestris), was sampled at 82 non-urban locations from six arbitrarily designated areas (Northwest, Northeast, Central Highlands, Central and East, Central and Southwest, Southeast), throughout Scotland during 2002-2003 and analysed for lead concentration and stable lead isotopes by flame atomic absorption spectrometry (AAS) and inductively coupled plasma-mass spectrometry (ICP-MS), respectively. The mean lead concentration and mean {sup 206}Pb/{sup 207}Pb ratio ({+-} 1 standard deviation, SD) for bark samples from the areas were as follows: Northwest (8.0 mg kg{sup -1}, 1.121 {+-} 0.014, n = 17), Northeast (8.9 mg kg{sup -1}, 1.117 {+-} 0.012, n = 12), Central Highlands (11.3 mg kg{sup -1}, 1.130 {+-} 0.010, n = 11), Central and East (35.3 mg kg{sup -1}, 1.120 {+-} 0.007, n = 10), Central and Southwest (20.6 mg kg{sup -1}, 1.125 {+-} 0.018, n = 22) and Southeast (34.4 mg kg{sup -1}, 1.120 {+-} 0.005, n = 10), with an overall mean lead concentration of 18.5 mg kg{sup -1} (range 0.6-146 mg kg{sup -1}, median 8.4 mg kg{sup -1}) and an overall mean {sup 206}Pb/{sup 207}Pb ratio of 1.122 {+-} 0.014 (range 1.089-1.168, median 1.122). The overall mean {sup 206}Pb/{sup 207}Pb ratio for bark was therefore significantly lower (p < 0.01, t test) than the mean atmospheric {sup 206}Pb/{sup 207}Pb ratio of 1.154 {+-} 0.006 (range 1.144-1.167, n = 50) and 1.154 {+-} 0.010 (range 1.134-1.171, n = 26) as determined in rainwater collected routinely at Glensaugh, Central Highlands, during 2002 and 2003, respectively. The bark {sup 206}Pb/{sup 207}Pb values, 90% of which lay between 1.10 and 1.14, were more akin to those recorded for the atmosphere (via rainwater, atmospheric particulates, moss, etc.) at various locations throughout Scotland during the 1990s, a decade over which the use of leaded petrol (mean {sup 206}Pb/{sup 207}Pb ratio = 1.076 {+-} 0.011) declined markedly before its complete withdrawal in 2000

  5. Exchangeable lead from prediction models relates to vetiver lead uptake in different soil types.

    Science.gov (United States)

    Andra, Syam S; Sarkar, Dibyendu; Saminathan, Sumathi K M; Datta, Rupali

    2011-12-01

    Prediction models for exchangeable soil lead, published earlier in this journal (Andra et al. 2010a), were developed using a suite of native lead (Pb) paint-contaminated residential soils from two US cities heavily populated with homes constructed prior to Pb ban in paints. In this study, we tested the feasibility and practical applications of these prediction models for developing a phytoremediation design using vetiver grass (Vetiveria zizanioides), a Pb-tolerant plant. The models were used to estimate the exchangeable fraction of Pb available for vetiver uptake in four lead-spiked soil types, both acidic and alkaline, with varying physico-chemical properties and that are different from those used to build the prediction models. Results indicate a strong correlation for predictable exchangeable Pb with the observed fraction and as well with total Pb accumulated by vetiver grass grown in these soils. The correlation coefficient for the predicted vs. observed exchangeable Pb with p vetiver grass with p < 0.001 was 0.948, 0.983, 0.929, and 0.969 for each soil type, respectively. This study suggests that the success of a phytoremediation design could be assessed upfront by predicting the exchangeable Pb fraction in a given soil type based on its properties. This helps in modifying the soil conditions to enhance phytoextraction of Pb from contaminated soils.

  6. Water-Induced Degradation in Lead Zinc Niobate-Lead Zirconate Titanate Soft Piezoelectric Ceramics

    Institute of Scientific and Technical Information of China (English)

    JIANG Xiang-Ping; CHEN Wan-Ping; PENG Zhi; ZENG Min; CHANWANG Li-Hua; YIN Qing-Rui

    2005-01-01

    @@ Water-induced degradation of lead zinc niobate-lead zirconate titanate (Pb(Zn1/3Nb2/3)O3-Pb(ZrTi)O3) soft piezoelectric ceramics is studied using electrochemical hydrogen charging, in which the silver electrodes of the piezoelectric ceramics constitute a cathode in 0.01-M NaOH solution to evolve hydrogen by electrolysis of water.It is found that with the increasing hydrogen charging time, the resonance impedance increases, the difference between the resonance frequency and the anti-resonance frequency decreases, the spontaneous polarization, the remanent polarization and the piezoelectric coefficient d33 decrease. The degradation behaviour of the soft piezoelectric ceramics can be explained to hydrogen incorporating into the lattice and forming hydroxy (OH-)bonds in the perovskite structure, which prevents the Ti ions from switching and increases the coercive field Ec.The degradation characteristics of the soft piezoelectric ceramics are quite different from that of lead zirconate titanate hard piezoelectric ceramics.

  7. Polymer Coats Leads on Implantable Medical Device

    Science.gov (United States)

    2008-01-01

    Langley Research Center s Soluble Imide (LaRC-SI) was discovered by accident. While researching resins and adhesives for advanced composites for high-speed aircraft, Robert Bryant, a Langley engineer, noticed that one of the polymers he was working with did not behave as predicted. After putting the compound through a two-stage controlled chemical reaction, expecting it to precipitate as a powder after the second stage, he was surprised to see that the compound remained soluble. This novel characteristic ended up making this polymer a very significant finding, eventually leading Bryant and his team to win several NASA technology awards, and an "R&D 100" award. The unique feature of this compound is the way that it lends itself to easy processing. Most polyimides (members of a group of remarkably strong and incredibly heat- and chemical-resistant polymers) require complex curing cycles before they are usable. LaRC-SI remains soluble in its final form, so no further chemical processing is required to produce final materials, like thin films and varnishes. Since producing LaRC-SI does not require complex manufacturing techniques, it has been processed into useful forms for a variety of applications, including mechanical parts, magnetic components, ceramics, adhesives, composites, flexible circuits, multilayer printed circuits, and coatings on fiber optics, wires, and metals. Bryant s team was, at the time, heavily involved with the aircraft polymer project and could not afford to further develop the polymer resin. Believing it was worth further exploration, though, he developed a plan for funding development and submitted it to Langley s chief scientist, who endorsed the experimentation. Bryant then left the high-speed civil transport project to develop LaRC-SI. The result is an extremely tough, lightweight thermoplastic that is not only solvent-resistant, but also has the ability to withstand temperature ranges from cryogenic levels to above 200 C. The thermoplastic

  8. Comparison of the radiological and chemical toxicity of lead

    Energy Technology Data Exchange (ETDEWEB)

    Beitel, G.A.; Mott, S.

    1995-03-01

    This report estimates the worst-case radiological dose to an individual from ingested lead containing picocurie levels of radionuclides and then compares the calculated radiological health effects to the chemical toxic effects from that same lead. This comparison provides an estimate of the consequences of inadvertently recycling, in the commercial market, lead containing nominally undetectable concentrations of radionuclides. Quantitative expressions for the radiological and chemical toxicities of lead are based on concentrations of lead in the blood stream. The result shows that the chemical toxicity of lead is a greater health hazard, by orders of magnitude, than any probable companion radiation dose.

  9. Histopathology of mallards dosed with lead and selected substitute shot

    Science.gov (United States)

    Locke, L.N.; Irby, H.D.; Bagley, G.E.

    1967-01-01

    The histopathological response of male game farm mallards fed lead, three types of plastic-coated lead, two lead-magnesium alloys, iron, copper, zinc-coated iron, and molybdenum-coated iron shot was studied. Mallards fed lead, plastic-coated lead, or lead-magnesium alloy shot developed a similar pathological response, including the formation of acid-fast intranuclear inclusion bodies in the kidneys. Birds fed iron or molybdenum-coated iron shot developed hemosiderosis of the liver. Two of four mallards fed zinc-coated iron shot also developed hemosiderosis of the liver. No lesions were found in mallards fed copper shot.

  10. Recent results on electroweak probes in lead-lead and proton-lead collisions from the ATLAS Detector at the LHC

    CERN Document Server

    Brooks, William; The ATLAS collaboration

    2015-01-01

    Photons and weak bosons do not interact strongly with the dense and hot medium formed in nuclear collisions, and thus they should be sensitive to the nuclear modification of parton distribution functions (nPDFs). In particular, proton-lead collisions provide an excellent opportunity to test nPDFs in a less dense environment than lead-lead. The ATLAS detector, optimized for searching new physics in proton-proton collisions, is especially well equipped to measure photons, Z and W bosons in the high occupancy environment produced in heavy ion collisions. Using the full data samples of 2.76 TeV lead-lead and 5.02 TeV proton-lead collisions we will present recent results on the prompt photon, Z and W boson yields as a function of centrality, transverse momentum and rapidity, from the ATLAS experiment. The binary collision scaling of the yields will be discussed in detail.

  11. An evaluation of lead concentrations in imported hot sauces.

    Science.gov (United States)

    Berger Ritchie, Jennifer A; Gerstenberger, Shawn L

    2013-01-01

    In the last decade, the U.S. Food and Drug Administration (FDA) has issued several warnings and recalls for food products that exceed FDA standards for lead. Products containing chili peppers and salt were often suspected as sources of lead contamination, and included items such as candy that are routinely investigated. However, products such as hot sauces that contain similar ingredients have not been the focus of evaluations. This study quantified lead concentrations in imported hot sauces, evaluated product compliance to existing United States standards, and calculated potential dietary lead exposure for children using the Integrated Exposure Uptake Biokinetic Model. Finally, recommendations for reducing the risk of lead exposure from hot sauces are provided. Twenty-five (25) bottles of imported hot sauces manufactured in Mexico and South America were purchased in Clark County, Nevada. All hot sauces were analyzed for lead concentrations, pH, and leaded packaging. Hot sauces were analyzed by inductively coupled plasma mass spectrometry and packaging was analyzed using x-ray fluorescence technology. Four brands of hot sauces (16%) exceeded 0.1 ppm lead, the current FDA action level for lead in candy. Hot sauces with lead concentrations >0.1 ppm lead contained salt and were manufactured in Mexico. Subsequent analysis of additional lots of hot sauces exceeding 0.1 ppm lead revealed inconsistent lead concentrations between and within manufacturer lots. The lead concentrations of the plastic hot sauce lids ranged from below the limit of detection to 2,028 ppm lead. There was no association between lead concentrations in hot sauces and pepper type. These results indicate the need for more rigorous screening protocols for products imported from Mexico, the establishment of an applicable standard for hot sauce, and resources to allow for the enforcement of existing food safety policies. The data reported herein represent the first known investigation of lead

  12. Prenatal lead exposure and bone growth. Doctoral thesis

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, J.D.; O' Flaherty, E.J.

    1990-07-24

    An experimental system of lead (7439921) related prenatal and postnatal growth retardation in rats was developed. Sprague-Dawley-rats and Long-Evans-rats were used in these studies. Rats were exposed to lead in their drinking water at up to 1000 parts per million. A significant effect on fetal bone mineralization could not be excluded and there was a definite effect on fetal body weight following maternal lead exposure. Reduced food intake during the first week of lead exposure was the primary determinant of reduced body and skeletal growth in the lead exposed weanling female rats. When maternal lead exposure was continued during lactation a greater degree of lead related growth retardation in rat offspring occurred than when maternal lead exposure was terminated at parturition. Combined prenatal and postnatal lead exposure impaired bone resorption and increased growth plate widths. In studies using matrix induced endochondral bone plaques, locally applied lead enhanced plaque mineralization through comineralization of lead with calcium. When lead was administered in drinking water, plaque mineralization was also enhanced through the comineralization of lead with calcium.

  13. Toxicity of Lead and Proposed Substitute Shot to Mallards

    Science.gov (United States)

    Longcore, J.R.; Andrews, R.; Locke, L.N.; Bagley, G.E.; Young, L.T.

    1974-01-01

    Poisoning of North American waterfowl resulting from the ingestion of lead shot by ducks, geese, and swans causes an estimated annual mortality of 2 to 3% of the population (Bellrose 1959). To alleviate this problem the search for a suitable substitute for lead has been underway since the early 1950's. Proposed substitutes for lead shot were evaluated in a series of acute toxicity tests with pen-reared mallards (Anas platyrhynchos). Most candidate materials were as toxic to ducks as commercial lead shot. Coating or alloying lead with other metals only delayed mortality among dosed ducks. The reputedly 'disintegrable' lead shot with the water-soluble binder and the lead containing biochemical additives were also as toxic to mallards as the commercial lead shot. Mortality was not significantly different among lead-dosed adult or first-year hen and drake pen-reared mallards; lead-dosed adult, wild mallards of both sexes; and lead-dosed adult, male black ducks (Anas rubripes). The ingestion of one lead shot, size 4, by each of 80 pen-reared mallards caused an average 19% mortality. The presence and type of grit in the gizzard had a measurable effect on erosion of ingested shot and on shot retention among dosed mallards. Significantly fewer lead-dosed ducks died when fed crushed oystershell grit than when fed either quartz grit or no grit.

  14. Assessment of leaching potential of highly leaded jewelry.

    Science.gov (United States)

    Weidenhamer, Jeffrey D; Newman, Breinn E; Clever, Ashley

    2010-05-15

    Lead is a potent neurotoxin particularly toxic to young children, and in response to recent poisonings of children and high levels of lead contamination in children's jewelry, US regulatory standards for lead content in these items have become much more stringent. Parents are often advised to throw out suspect items in the trash. While household wastes are generally exempt from consideration as hazardous waste, the potential for leaching of hazardous quantities of lead from such items is unknown. A modified Toxicity Characteristic Leaching Procedure (TCLP), in which intact jewelry components were subjected to leaching, was used to evaluate the potential for leaching of lead from highly leaded jewelry. Of 62 jewelry components tested, 61 exceeded the US regulatory standard for lead of 5mg/L, and leachate lead concentrations averaged 1460 mg/L. Twenty-six of the component items tested yielded TCLP lead concentrations exceeding 1000 mg/L. These results demonstrate that highly leaded jewelry items may leach significant amounts of lead, and provide another reason to remove lead from these products. Furthermore, these results suggest that while the volume of such items in the municipal solid waste (MSW) stream is small, they have the potential to contribute significant quantities of lead to MSW leachates.

  15. Lead stress effects on physiobiochemical activities of higher plants.

    Science.gov (United States)

    Sengar, Rakesh Singh; Gautam, Madhu; Sengar, Rajesh Singh; Garg, Sanjay Kumar; Sengar, Kalpana; Chaudhary, Reshu

    2008-01-01

    Lead is a metallic pollutant emanating from various environmental sources including industrial wastes, combustion of fossil fuels, and use of agrochemicals. Lead may exist in the atmosphere as dusts, fumes, mists, and vapors, and in soil as a mineral. Soils along roadsides are rich in lead because vehicles burn leaded gasoline, which contributes to environmental lead pollution. Other important sources of lead pollution are geological weathering, industrial processing of ores and minerals, leaching of lead from solid wastes, and animal and human excreta. Lead is nondegradable, readily enters the food chain, and can subsequently endanger human and animal health. Lead is one of the most important environment pollutants and deserves the increasing attention it has received in recent decades. The present effort was undertaken to review lead stress effects on the physiobiochemical activity of higher plants. Lead has gained considerable attention as a potent heavy metal pollutant because of growing anthropogenic pressure on the environment. Lead-contaminated soils show a sharp decline in crop productivity. Lead is absorbed by plants mainly through the root system and in minor amounts through the leaves. Within the plants, lead accumulates primarily in roots, but some is translocated to aerial plant parts. Soil pH, soil particle size, cation-exchange capacity, as well as root surface area, root exudation, and mycorrhizal transpiration rate affect the availability and uptake of lead by plants. Only a limited amount of lead is translocated from roots to other organs because there are natural plant barriers in the root endodermis. At lethal concentrations, this barrier is broken and lead may enter vascular tissues. Lead in plants may form deposits of various sizes, present mainly in intercellular spaces, cell walls, and vacuoles. Small deposits of this metal are also seen in the endoplasmic reticulum, dictyosome, and dictyosome-derived vesicles. After entering the cells, lead

  16. The elephant in the playground: confronting lead-contaminated soils as an important source of lead burdens to urban populations.

    Science.gov (United States)

    Filippelli, Gabriel M; Laidlaw, Mark A

    2010-01-01

    Although significant headway has been made over the past 50 years in understanding and reducing the sources and health risks of lead, the incidence of lead poisoning remains shockingly high in urban regions of the United States. At particular risk are poor people who inhabit the polluted centers of our older cities without the benefits of adequate nutrition, education, and access to health care. To provide a future with fewer environmental and health burdens related to lead, we need to consider the multiple pathways of lead exposure in children, including their continued contact with dust derived from inner-city soils. Recent research into the causes of seasonal variations in blood-lead levels among children has confirmed the importance of soil in lead exposure. "Capping" lead-contaminated soil with lead-free soil or soil amendment appears to be a simple and cost-effective way to reduce the lead load for urban youth.

  17. Using Lead Concentrations and Stable Lead Isotope Ratios to Identify Contamination Events in Alluvial Soils

    Directory of Open Access Journals (Sweden)

    Diane Saint-Laurent

    2010-01-01

    Full Text Available Soils contaminated with hydrocarbons (C10–C50, polycyclic aromatic hydrocarbons (PAHs, and other contaminants (e.g., As, Cd, Cu, Pb were recently discovered on the banks of the Saint-François and Massawippi rivers. Alluvial soils are contaminated over a distance of 100 kilometers, and the level of the contaminated-hydrocarbon layer in the soil profiles is among the highest at the Windsor and Richmond sites. Concentrations of lead and stable lead isotope ratios (204Pb/206Pb, 207Pb/206Pb, 208Pb/206Pb are also used to identify contamination events. The maximum and minimum values detected in soil profiles for arsenic, cadmium, and lead vary from 3.01 to 37.88 mg kg-1 (As, 0.11 to 0.81 mg kg-1 (Cd 12.32 to 149.13 mg kg-1 (Pb, respectively, while the 207Pb/206Pb isotopic ratio values are between 0.8545 and 0.8724 for all the profiles. The highest values of trace elements (As, Pb and Zn were detected in the hydrocarbon layer (C10–C50, most often located at the bottom of the profiles (160, 200, and 220 cm in depth. The various peaks recorded in the soils and the position of the profiles suggest that various contaminants were transported by the river on several occasions and infiltrated the soil matrix or deposited on floodplains during successive floods. Atmospheric particles which entered the river or deposited on riverbanks must also be considered as another source of pollution recorded in soils.

  18. Biological index of environmental lead pollution: accumulation of lead in liver and kidney in mice.

    Science.gov (United States)

    Takano, T; Okutomi, Y; Mochizuki, M; Ochiai, Y; Yamada, F; Mori, M; Ueda, F

    2015-12-01

    Lead (Pb) is known to be highly poisonous, and the acute poisoning of Cd causes the abdominal pains, vomiting, and shock. The digestive and nervous symptom is observed in the chronic lead poisoning. It was also known that the defect in hemoglobin synthesis by Pb produce anemia. The release of Pb into the environment presents a source of exposure for wild animals. In this study, we examined the utility of a new Pb-monitoring index in mice administered Pb. A solution containing 0.02, 0.2, 2, or 4 ppm lead chloride (PbCl2) was administered intraperitoneally to mice, and the Pb contents of the kidney and liver were determined at designated time points. The mean Pb content of both organs increased depending on the administered Pb dosage. Although the results of control was near the detection limits, the administration of 4 ppm in 4 weeks resulted in Pb levels of 260 mg ppm/wet weight and 110 ppm wet weight in the kidney and liver, respectively. However, there were no significant relationships among administered dose, duration of Pb treatment, and liver or kidney Pb content. Then, values in all mice administered control or 0.02 mg Pb were located inside the ellipse, representing the confidence area of the new index, and values in all mice administered more than 2 mg Pb were located outside the ellipse. These results confirm that animals exposed to high concentrations of Pb would be detected by this new index.

  19. Leaded gasoline to Be Phased out in China

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    @@ China is taking measures to phase out leaded gasoline and ensure less emission from motor vehicles. The government will implement pricing reforms so that unleaded gasoline costs less than leaded fuel.

  20. Effect of particle size on lead absorption from the gut

    Energy Technology Data Exchange (ETDEWEB)

    Barltrop, D.; Meek, F.

    1979-07-01

    The relationship between particle size and absorption of lead particles from the gastrointestinal tract of the rat has been investigated. Preparations of metallic lead of particle size between 0. and 250..mu.. were incorporated in laboratory rat diets and absorption determined by measurement of tissue lead concentrations attained under standard conditions. An inverse relationship was found between particle size and lead absorption; this relationship was most marked in the 0 to 100..mu.. range. A five-fold enhancement of absorption was observed from the diet with lead particles of mean size 6..mu.., compared with 197..mu.. particle size. Lead absorption from dried paint films containing lead chromate and lead octoate was measured using a similar technique. a marked enhancement of absorption was observed for both paints when particle size was reduced from 500 to 1000..mu.. to < 50..mu...

  1. Protect Your Family from Lead in Your Home

    Science.gov (United States)

    ... Hazards Deteriorating lead-based paint (peeling, chipping, chalking, cracking, or damaged paint) is a hazard and needs ... Housing Rule, which protects families in pre-1978 assisted housing, and for the lead hazard control and ...

  2. Smoking Thickens Heart Wall, Leading to Heart Failure: Study

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_160932.html Smoking Thickens Heart Wall, Leading to Heart Failure: Study ... 13, 2016 TUESDAY, Sept. 13, 2016 (HealthDay News) -- Smoking leads to heart failure by causing thickened heart ...

  3. How lead consultants approach educational change in postgraduate medical education.

    NARCIS (Netherlands)

    Fokkema, J.P.; Westerman, M.; Teunissen, P.W.; Lee, N.; Scherpbier, A.J.J.A.; Vleuten, C.P.M. van der; Dorr, P.J.; Scheele, F.

    2012-01-01

    CONTEXT: Consultants in charge of postgraduate medical education (PGME) in hospital departments ('lead consultants') are responsible for the implementation of educational change. Although difficulties in innovating in medical education are described in the literature, little is known about how lead

  4. The Lead-Safe Certified Guide to Renovate Right

    Science.gov (United States)

    ... EPA’s website at epa.gov/getleadsafe or by calling the National Lead Information Center at 1-800- ... reducing lead hazards. If your state or local government has requirements more stringent than those described in ...

  5. Neurotoxicity and Biomarkers of Lead Exposure:a Review

    Institute of Scientific and Technical Information of China (English)

    Kang-sheng Liu; Jia-hu Hao; Yu Zeng; Fan-chun Dai; Ping-qing Gu

    2013-01-01

    Appropriate selection and measurement of lead biomarkers of exposure are critically important for health care management purposes, public health decision making, and primary prevention synthesis. Lead is one of the neurotoxicants that seems to be involved in the etiology of psychologies. Biomarkers are generally classified into three groups:biomarkers of exposure, effect, and susceptibility.The main body compartments that store lead are the blood, soft tissues, and bone;the half-life of lead in these tissues is measured in weeks for blood, months for soft tissues, and years for bone. Within the brain, lead-induced damage in the prefrontal cerebral cortex, hippocampus, and cerebellum can lead to a variety of neurological disorders, such as brain damage, mental retardation, behavioral problems, nerve damage, and possibly Alzheimer’s disease, Parkinson’s disease, and schizophrenia. This paper presents an overview of biomarkers of lead exposure and discusses the neurotoxic effects of lead with regard to children and adults.

  6. US EPA Nonattainment Areas and Designations-Lead (2008 NAAQS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — This web service contains the following layers: Lead NAA 2008 NAAQS and Lead NAA Centroids 2008 NAAQS. Full FGDC metadata records for each layer may be found by...

  7. Recycling of waste lead storage battery by vacuum methods.

    Science.gov (United States)

    Lin, Deqiang; Qiu, Keqiang

    2011-07-01

    Waste lead storage battery is the most important recyclable lead material not only in various European and other OECD countries but also in China. Pollution control of lead has become the focus of people's attention in the world. A vacuum process for recycling waste lead storage battery was developed in this work. The experimental results showed that all the valuable materials in waste lead storage battery could be satisfactorily recycled by vacuum technologies. The vacuum melting of lead grids and the vacuum reduction of lead pastes produce the lead bullion with the direct recovery ratio of 96.29% and 98.98%, respectively. The vacuum pyrolysis of plastics can produce pyrolysis oil with yield of more than 93 wt.%. These vacuum recycling technologies offer improvements in metallurgical and environmental performance.

  8. Elimination of Airborne Lead Contamination from Caliber .22 Ammunition.

    Science.gov (United States)

    1987-06-01

    composition is comprised of the toxic heavy metals: lead and barium . The barium , however, is considered a minor contributor to the contamination...lead styphnate priming mixture and 2.9 grains of Winchester (WC371) propellant. This propellant quantity resulted in near the maximum recommended...standard lead styphnate primer mixture to four times the volume of the lead styphnate primer mixture. The amount of new primer mixture which produced

  9. Medium Caliber Lead-Free Electric Primer. Version 2

    Science.gov (United States)

    2012-09-01

    eliminate the lead styphnate and barium nitrate components in the current 20mm electric primer for the purposes of protecting our troops, production...Lead nitrate is added to the magnesium bis(trinitroresorcinol) to form lead styphnate and magnesium nitrate. The additional ingredient, barium ...conventional lead styphnate primers. On small scale samples, outstanding all-up round action times (AUR-ATs) were obtained for ambient (2.92 ms) and

  10. Childhood Lead Exposure from Battery Recycling in Vietnam

    OpenAIRE

    Daniell, William E.; Lo Van Tung; Wallace, Ryan M.; Havens, Deborah J.; Karr, Catherine J; Nguyen Bich Diep; Croteau, Gerry A.; Beaudet, Nancy J.; Nguyen Duy Bao

    2015-01-01

    Background. Battery recycling facilities in developing countries can cause community lead exposure. Objective. To evaluate child lead exposure in a Vietnam battery recycling craft village after efforts to shift home-based recycling outside the village. Methods. This cross-sectional study evaluated 109 children in Dong Mai village, using blood lead level (BLL) measurement, parent interview, and household observation. Blood samples were analyzed with a LeadCare II field instrument; highest BLLs...

  11. Research of lead extract method from accumulator scrap

    Directory of Open Access Journals (Sweden)

    Віктор Юрійович Кушнеров

    2016-12-01

    Full Text Available The analysis of production and consumption of lead from primary and secondary raw material is executed. It is determined that approximately 56 % general world lead production consists of lead-content secondary raw material processing – scrap and wastes of lead and accumulator scrap. Using thermodynamic analysis, it is determined that potassium bicarbonate has an advantage at processing of sulfate constituent of secondary raw material

  12. 77 FR 5247 - Draft Integrated Science Assessment for Lead

    Science.gov (United States)

    2012-02-02

    ... AGENCY Draft Integrated Science Assessment for Lead AGENCY: Environmental Protection Agency (EPA). ACTION..., ``Second External Review Draft Integrated Science Assessment for Lead'' (EPA/600/R-10/075B). The document... lead (Pb). EPA is releasing this draft document to seek review by the Clean Air Scientific...

  13. 77 FR 70776 - Draft Integrated Science Assessment for Lead

    Science.gov (United States)

    2012-11-27

    ... AGENCY Draft Integrated Science Assessment for Lead AGENCY: Environmental Protection Agency (EPA). ACTION..., ``Third External Review Draft Integrated Science Assessment for Lead'' (EPA/600/R-10/075C). The document... lead (Pb). EPA is releasing this draft document to seek review by the Clean Air Scientific...

  14. 76 FR 38650 - Draft Integrated Science Assessment for Lead

    Science.gov (United States)

    2011-07-01

    ... AGENCY Draft Integrated Science Assessment for Lead AGENCY: Environmental Protection Agency. ACTION... Draft Integrated Science Assessment for Lead'' (EPA/600/R-10/075A). The original Federal Register notice... Development as part of the review of the National Ambient Air Quality Standards (NAAQS) for Lead. DATES:...

  15. Lead Oxides Used in the Treatment of Empacho.

    Science.gov (United States)

    Ackerman, Alan

    Many Mexican Americans regard "Azarcon," a lead tetroxide powder, and "Greta," a lead monoxide powder, as desired medical treatments for empacho, a perceived intestinal blockage. The folk medicines, available in Mexico but not in the United States, can cause lead poisoning, which can result in brain swelling, coma, permanent mental retardation,…

  16. 40 CFR 51.117 - Additional provisions for lead.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Additional provisions for lead. 51.117... Additional provisions for lead. In addition to other requirements in §§ 51.100 through 51.116 the following requirements apply to lead. To the extent they conflict, there requirements are controlling over those of...

  17. Access Management of Secondary Lead Industry Becomes More Standardized

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>The Ministry of Environmental Protection and The Ministry of Industry and Information Technology promulgated policies and regulations including the"Access Condition for Secondary Lead Industry"(The Condition"),and"Opinions on Promoting Standardized Development of Lead-acid Battery and Secondary Lead Industries"in August 2012,

  18. 40 CFR 52.2236 - Control strategy; lead.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy; lead. 52.2236 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Tennessee § 52.2236 Control strategy; lead... on October 6, 1994. These revisions address the requirements necessary to change a lead...

  19. 40 CFR 52.1681 - Control strategy: Lead.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Lead. 52.1681 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) New York § 52.1681 Control strategy: Lead. As part of the attainment demonstration for lead, the State of New York has committed to rate all...

  20. 40 CFR 60.372 - Standards for lead.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for lead. 60.372 Section 60...) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Lead-Acid Battery Manufacturing Plants § 60.372 Standards for lead. (a) On and after the date on which the performance...

  1. 78 FR 38318 - Integrated Science Assessment for Lead

    Science.gov (United States)

    2013-06-26

    ... AGENCY Integrated Science Assessment for Lead AGENCY: Environmental Protection Agency (EPA). ACTION..., ``Integrated Science Assessment for Lead'' (EPA/600/R-10/075F). The document was prepared by the National... review of the national ambient air quality standards (NAAQS) for lead (Pb). DATES: The document will...

  2. Lead batteries. Citations from the NTIS data base

    Science.gov (United States)

    Cavagnaro, D. M.

    1980-07-01

    The design, development, components, fabrication, chemistry, and testing of lead batteries are cited in this compilation of federally-funded research. Specific applications for spacecraft, consumer products, and electric vehicles are covered. Studies on lead recovery from battery scrap are covered. Several abstracts on lead toxicity in industrial plants are also cited.

  3. 76 FR 70975 - Petition Requesting Exception From Lead Content Limits

    Science.gov (United States)

    2011-11-16

    ... COMMISSION Petition Requesting Exception From Lead Content Limits AGENCY: Consumer Product Safety Commission...'') has received a petition requesting an exception from the 100 ppm lead content limit under section 101... 101(b)(1) of the CPSIA provides for a functional purpose exception from lead content limits...

  4. Lead-Tungstate Crystal of the ALICE Photon Spectrometer (PHOS)

    CERN Multimedia

    2003-01-01

    The photon spectrometer (PHOS) is designed to measure the temperature of collisions by detecting photons emerging from them. It will be made of lead tungstate crystals like these. When high-energy photons strike lead tungstate, they make it glow, or scintillate, and this glow can be measured. Lead tungstate is extremely dense (denser than iron), stopping most photons that reach it.

  5. Reducing Lead in School Drinking Water: A Case Study.

    Science.gov (United States)

    Odell, Lee

    1991-01-01

    The Seattle School District began a program in 1990 to identify lead levels in the district's drinking water and to implement measures to lower any high lead levels. Recounts each of the seven steps of the program, discusses what the district found, and explains how it lowered lead levels in the drinking water. (MLF)

  6. [Anemia in workers exposed to lead: update on differential diagnosis].

    Science.gov (United States)

    Di Lorenzo, L; Soleo, L; Cassano, F; Elia, G; Schiavulli, N; Martino, M G; Corfiati, M; Bulfaro, D; Apostoli, P

    2005-01-01

    Occupational lead exposure can cause anemia at blood lead levels >50 microg/dl, as high as rarely occurs in industrialized countries nowadays. Whereas other forms of anemia are fairly probable to be found in lead exposed workers, especially in areas highly endemicfor extraoccupational anemias, such as beta thalassemia and iron deficiency anemia. The etiology of anemias has to be correctly defined in order to assess suitable therapeutical approaches and medicolegal consequences. The objective of this study is to verify in male lead exposed workers whether an accurate evaluation of hemocromocytometric parameters and of usual biological indices of lead exposure and effect on heme can differentiate the most common forms of anemia in Southern Italy. 68 workers occupationally exposed to low to moderate lead doses were studied and 59 workers of an alimentary plant have been taken as control group. On venous blood samples collected from these workers a complete hemocromocytometric test was performed and blood lead and erythrocytic zincoprotoporphyrin were determined. Anemia (Hb lead exposed workers and in a nonexposed worker. The reasoned evaluation of laboratory parameters led to identify among lead exposed workers four subjects with high probability of beta-thalassemic trait and two with lead poisoning anemia. Moreover a diagnostic algorithm was developed based on literature that seems to be able to discriminate lead poisoning from other causes of anemia in lead exposed workers in this study.

  7. Phytoremediation Potential of Lead-Contaminated Soil Using Tropical Grasses

    Science.gov (United States)

    The global problem concerning contamination of the environment because of human activities is increasing. Most of the environmental contaminants are chemical by-products and heavy metals such as lead (Pb). Lead released into the environment makes its way into the air, soil and water. Lead contribute...

  8. Impact of the California lead ammunition ban on reducing lead exposure in golden eagles and turkey vultures.

    Directory of Open Access Journals (Sweden)

    Terra R Kelly

    Full Text Available Predatory and scavenging birds may be exposed to high levels of lead when they ingest shot or bullet fragments embedded in the tissues of animals injured or killed with lead ammunition. Lead poisoning was a contributing factor in the decline of the endangered California condor population in the 1980s, and remains one of the primary factors threatening species recovery. In response to this threat, a ban on the use of lead ammunition for most hunting activities in the range of the condor in California was implemented in 2008. Monitoring of lead exposure in predatory and scavenging birds is essential for assessing the effectiveness of the lead ammunition ban in reducing lead exposure in these species. In this study, we assessed the effectiveness of the regulation in decreasing blood lead concentration in two avian sentinels, golden eagles and turkey vultures, within the condor range in California. We compared blood lead concentration in golden eagles and turkey vultures prior to the lead ammunition ban and one year following implementation of the ban. Lead exposure in both golden eagles and turkey vultures declined significantly post-ban. Our findings provide evidence that hunter compliance with lead ammunition regulations was sufficient to reduce lead exposure in predatory and scavenging birds at our study sites.

  9. Diphoton production in lead-lead and proton-proton UPC

    CERN Document Server

    Klusek-Gawenda, Mariola

    2016-01-01

    We discuss diphoton semi(exclusive) production in ultraperipheral $PbPb$ collisions at energy of $\\sqrt{s_{NN}}=$ 5.5 TeV (LHC). The nuclear calculations are based on equivalent photon approximation in the impact parameter space. The cross sections for elementary $\\gamma \\gamma \\to \\gamma \\gamma$ subprocess are calculated including three different mechanisms: box diagrams with leptons and quarks in the loops, a VDM-Regge contribution with virtual intermediate hadronic excitations of the photons and the two-gluon exchange contribution (formally three-loops) to elastic photon-photon scattering in the high-energy approximation. We got relatively high cross sections in $PbPb$ collisions ($306$ nb). This opens a possibility to study the $\\gamma \\gamma \\to \\gamma \\gamma$ (quasi)elastic scattering at the LHC. We find that the cross section for elastic $\\gamma\\gamma$ scattering could be measured in the lead-lead collisions for the diphoton invariant mass up to $W_{\\gamma\\gamma} \\approx 15-20$ GeV. We identify region(...

  10. Toxic exposure of songbirds to lead in the Southeast Missouri Lead Mining District.

    Science.gov (United States)

    Beyer, W Nelson; Franson, J Christian; French, John B; May, Thomas; Rattner, Barnett A; Shearn-Bochsler, Valerie I; Warner, Sarah E; Weber, John; Mosby, David

    2013-10-01

    Mining and smelting in the Southeast Missouri Lead Mining District has caused widespread contamination of soils with lead (Pb) and other metals. Soils from three study sites sampled in the district contained from approximately 1,000-3,200 mg Pb/kg. Analyses of earthworms [33-4,600 mg Pb/kg dry weight (dw)] collected in the district showed likely high Pb exposure of songbirds preying on soil organisms. Mean tissue Pb concentrations in songbirds collected from the contaminated sites were greater (p toxic effects, and 4 (12%) with life-threatening toxic effects. Acid-fast renal intranuclear inclusion bodies, which are indicative of Pb poisoning, were detected in kidneys of two robins that had the greatest renal Pb concentrations (952 and 1,030 mg/kg dw). Mean activity of the enzyme delta-aminolevulinic acid dehydratase (ALAD) in red blood cells, a well-established bioindicator of Pb poisoning in birds, was decreased by 58-82% in songbirds from the mining sites. We conclude that habitats within the mining district with soil Pb concentrations of ≥1,000 mg Pb/kg are contaminated to the extent that they are exposing ground-feeding songbirds to toxic concentrations of Pb.

  11. Chronic Lead Poisoning in Iran; a Silent Disease

    Directory of Open Access Journals (Sweden)

    Omid Mahrpour

    2012-08-01

    Full Text Available Lead poisoning is one of the oldest, permanent hazards in the world and Iran is not excluded and has the same risk of lead toxicity. Humans have known about the potential hazards of lead poisoning for centuries. Lead is widespread in natural substances, and almost all people are in touch with this insidiously toxic heavy metal in different ways either in workplace or at homes. The level of exposure is higher in most of countries because of extensive use of lead containing materials in normal life and the environment.

  12. Mechanical Reliability of Aged Lead-­Free Solders

    OpenAIRE

    Lewin, Susanne

    2012-01-01

    The usage of lead-­free solder joints in electronic packaging is of greatest concern to the electronic industry due to the health and environmental hazards arising with the use of lead. As a consequence, lead is legally prohibited in the European Union and the industry is aiming to produce lead-free products.            The reliability of solder joints is an important issue as the failure could destroy the whole function of a product. SnAgCu is a commonly used alloy for lead-­free solders. Co...

  13. Lead-induced peripheral neuropathy following ayurvedic medication

    Directory of Open Access Journals (Sweden)

    Singh Surjit

    2009-09-01

    Full Text Available Lead poisoning following intake of Ayurvedic medication is one of the recent areas of concern. We report a case of a 58-year-old type II diabetic man who was stable with diet control and 30 mg pioglitazone per day. He took Ayurvedic medication for generalized weakness and developed peripheral neuropathy following its intake. He was found to have high blood and urinary lead levels and was diagnosed to have subacute lead poisoning. He was treated with d-Penicillamine for 8 weeks, following which his lead levels became normal. The use of d-Penicillamine was proved highly effective in treating a case of lead poisoning.

  14. Environmental lead toxicity: Nutrition as a component of intervention

    Energy Technology Data Exchange (ETDEWEB)

    Mahaffey, K.R. (National Institute of Environmental Health Sciences, Research Triangle Park, NC (USA))

    1990-11-01

    The influence of nutritional status on susceptibility to the toxicity of lead is discussed. Emphasis is given to dietary factors of substantial clinical importance. Subtle changes in susceptibility are difficult to evaluate under conditions of overwhelming lead exposure. It is clear that subtle effects of lead exposure on neurobehavioral and cognitive development are a major concern. The role of nutrition is considered to be an adjunct to reduction of environmental lead exposure, which is the primary means of reducing adverse health effects of lead. Nutrition should be evaluated as a component of strategies to address this broad societal issue.

  15. Lead-acid battery technologies fundamentals, materials, and applications

    CERN Document Server

    Jung, Joey; Zhang, Jiujun

    2015-01-01

    Lead-Acid Battery Technologies: Fundamentals, Materials, and Applications offers a systematic and state-of-the-art overview of the materials, system design, and related issues for the development of lead-acid rechargeable battery technologies. Featuring contributions from leading scientists and engineers in industry and academia, this book:Describes the underlying science involved in the operation of lead-acid batteriesHighlights advances in materials science and engineering for materials fabricationDelivers a detailed discussion of the mathematical modeling of lead-acid batteriesAnalyzes the

  16. Knowledge-Based, Central Nervous System (CNS) Lead Selection and Lead Optimization for CNS Drug Discovery.

    Science.gov (United States)

    Ghose, Arup K; Herbertz, Torsten; Hudkins, Robert L; Dorsey, Bruce D; Mallamo, John P

    2012-01-18

    The central nervous system (CNS) is the major area that is affected by aging. Alzheimer's disease (AD), Parkinson's disease (PD), brain cancer, and stroke are the CNS diseases that will cost trillions of dollars for their treatment. Achievement of appropriate blood-brain barrier (BBB) penetration is often considered a significant hurdle in the CNS drug discovery process. On the other hand, BBB penetration may be a liability for many of the non-CNS drug targets, and a clear understanding of the physicochemical and structural differences between CNS and non-CNS drugs may assist both research areas. Because of the numerous and challenging issues in CNS drug discovery and the low success rates, pharmaceutical companies are beginning to deprioritize their drug discovery efforts in the CNS arena. Prompted by these challenges and to aid in the design of high-quality, efficacious CNS compounds, we analyzed the physicochemical property and the chemical structural profiles of 317 CNS and 626 non-CNS oral drugs. The conclusions derived provide an ideal property profile for lead selection and the property modification strategy during the lead optimization process. A list of substructural units that may be useful for CNS drug design was also provided here. A classification tree was also developed to differentiate between CNS drugs and non-CNS oral drugs. The combined analysis provided the following guidelines for designing high-quality CNS drugs: (i) topological molecular polar surface area of <76 Å(2) (25-60 Å(2)), (ii) at least one (one or two, including one aliphatic amine) nitrogen, (iii) fewer than seven (two to four) linear chains outside of rings, (iv) fewer than three (zero or one) polar hydrogen atoms, (v) volume of 740-970 Å(3), (vi) solvent accessible surface area of 460-580 Å(2), and (vii) positive QikProp parameter CNS. The ranges within parentheses may be used during lead optimization. One violation to this proposed profile may be acceptable. The

  17. Sublethal effects of chronic lead ingestion in mallard ducks

    Science.gov (United States)

    Finley, M.T.; Dieter, M.P.; Locke, L.N.

    1976-01-01

    Mallard drakes (Anas platyrhynchos) fed 1, 5, or 25 ppm lead nitrate were bled and sacrificed at 3-wk intervals. No mortality occurred, and the pathologic lesions usually associated with lead poisoning were not found. Changes in hematocrit and hemoglobin concentration did not occur. After 3-wk ducks fed 25 ppm lead exhibited a 40% inhibition of blood delta-aminolevulinic acid dehydratase activity that persisted through 12 wk exposure. After 12 wk treatment similar enzyme inhibition was present in the ducks fed 5 ppm lead. At 3 wk there was a small accumulation of lead (less than 1 ppm) in the liver and kidneys of ducks fed 25ppm lead; no further increases occurred throughout the exposure. No significant accumulation of lead occurred the the tibiae or wing bones. Groups of ducks fed 5 and 25 ppm diets for 12 wk were placed on clean feed and examined through a 12 wk posttreatment period. After 3 wk on clean diet delta-aminolevulinic acid dehydratase activity and lead concentrations in the blood had returned to pretreatment levels. Even though lead concentrations in the blood, soft organs and bone were low, a highly significant negative correlation between blood lead and blood enzyme activity was obtained. This enzyme bioassay should provide a sensitive and precise estimate for monitoring lead in the blood for waterflow.

  18. Tunable heat pump by modulating the coupling to the leads.

    Science.gov (United States)

    Cuansing, Eduardo C; Wang, Jian-Sheng

    2010-08-01

    We follow the nonequilibrium Green's function formalism to study time-dependent thermal transport in a linear chain system consisting of two semi-infinite leads connected together by a coupling that is harmonically modulated in time. The modulation is driven by an external agent that can absorb and emit energy. We determine the energy current flowing out of the leads exactly by solving numerically the Dyson equation for the contour-ordered Green's function. The amplitude of the modulated coupling is of the same order as the interparticle coupling within each lead. When the leads have the same temperature, our numerical results show that modulating the coupling between the leads may direct energy to either flow into the leads simultaneously or flow out of the leads simultaneously, depending on the values of the driving frequency and temperature. A special combination of values of the driving frequency and temperature exists wherein no net energy flows into or out of the leads, even for long times. When one of the leads is warmer than the other, net energy flows out of the warmer lead. For the cooler lead, however, the direction of the energy current flow depends on the values of the driving frequency and temperature. In addition, we find transient effects to become more pronounced for higher values of the driving frequency.

  19. Assessing the sustainability of lead utilization in China.

    Science.gov (United States)

    Sun, Lingyu; Zhang, Chen; Li, Jinhui; Zeng, Xianlai

    2016-12-01

    Lead is not only one of heavy metals imposing environment and health risk, but also critical resource to maintain sustainable development of many industries. Recently, due to the shortage of fossil fuels, clean energy vehicles, including electric bicycle, have emerged and are widely adopted soon in the world. China became the world's largest producer of primary lead and a very significant consumer in the past decade, which has strained the supplies of China's lead deposits from lithosphere and boost the anthropogenic consumption of metallic lead and lead products. Here we summarize that China's lead demand will continually increase due to the rapid growth of electric vehicle, resulting in a short carrying duration of lead even with full lead recycling. With these applications increasing at an annual rate of 2%, the carrying duration of lead resource until 2030 will oblige that recycling rate should be not less than 90%. To sustain lead utilization in China, one approach would be to improve the utilization technology, collection system and recycling technology towards closed-loop supply chain. Other future endeavors should include optimizing lead industrial structure and development of new energy.

  20. Removal of lead contaminated dusts from hard surfaces.

    Science.gov (United States)

    Lewis, Roger D; Condoor, Sridhar; Batek, Joe; Ong, Kee Hean; Backer, Denis; Sterling, David; Siria, Jeff; Chen, John J; Ashley, Peter

    2006-01-15

    Government guidelines have widely recommended trisodium phosphate (TSP) or "lead-specific" cleaning detergents for removal of lead-contaminated dust (LCD) from hard surfaces, such as floors and window areas. The purpose of this study was to determine if low-phosphate, non-lead-specific cleaners could be used to efficiently remove LCD from 3 types of surfaces (vinyl flooring, wood, and wallpaper). Laboratory methods were developed and validated for simulating the doping, embedding, and sponge cleaning of the 3 surface types with 4 categories of cleaners: lead-specific detergents, nonionic cleaners, anionic cleaners, and trisodium phosphate (TSP). Vinyl flooring and wood were worn using artificial means. Materials were ashed, followed by ultrasound extraction, and anodic stripping voltammetry (ASV). One-way analysis of variance approach was used to evaluate the surface and detergent effects. Surface type was found to be a significant factor in removal of lead (p < 0.001). Vinyl flooring cleaned better than wallpaper by over 14% and wood cleaned better than wallpaper by 13%. There was no difference between the cleaning action of vinyl flooring and wood. No evidence was found to support the use of TSP or lead-specific detergents over all-purpose cleaning detergents for removal of lead-contaminated dusts. No-phosphate, non-lead-specific detergents are effective in sponge cleaning of lead-contaminated hard surfaces and childhood lead prevention programs should consider recommending all-purpose household detergents for removal of lead-contaminated dust after appropriate vacuuming.

  1. Relation between blood lead levels and childhood anemia in India.

    Science.gov (United States)

    Jain, Nitin B; Laden, Francine; Guller, Ulrich; Shankar, Anoop; Kazani, Shamsah; Garshick, Eric

    2005-05-15

    Lead pollution is a substantial problem in developing countries such as India. The US Centers for Disease Control and Prevention has defined an elevated blood lead level in children as > or = 10 microg/dl, on the basis of neurologic toxicity. The US Environmental Protection Agency suggests a threshold lead level of 20-40 microg/dl for risk of childhood anemia, but there is little information relating lead levels anemia. Therefore, the authors examined the association between lead levels as low as 10 mug/dl and anemia in Indian children under 3 years of age. Anemia was divided into categories of mild (hemoglobin level 10-10.9 g/dl), moderate (hemoglobin level 8-9.9 g/dl), and severe (hemoglobin level Lead levels lead levels > or = 10-19.9 microg/dl and 97 (9%) had levels > or = 20 microg/dl. After adjustment for child's age, duration of breastfeeding, standard of living, parent's education, father's occupation, maternal anemia, and number of children in the immediate family, children with lead levels > or = 10 microg/dl were 1.3 (95% confidence interval: 1.0, 1.7) times as likely to have moderate anemia as children with lead levels anemia was 1.7 (95% confidence interval: 1.1, 2.6). Health agencies in India should note the association of elevated blood lead levels with anemia and make further efforts to curb lead pollution and childhood anemia.

  2. 24 CFR 35.1320 - Lead-based paint inspections, paint testing, risk assessments, lead-hazard screens, and...

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Lead-based paint inspections, paint testing, risk assessments, lead-hazard screens, and reevaluations. 35.1320 Section 35.1320 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development LEAD-BASED...

  3. A study on lead toxicity among the workers in an unorganized sector of lead-acid battery industry

    Directory of Open Access Journals (Sweden)

    Partha Sarathy Naidana

    2013-10-01

    Full Text Available Aims of the study: (1-To study various manifestations of lead toxicity at different levels of exposure among the Lead-Acid battery workers and (2-To study various factors contributing to the toxicity of lead among the workers. Results: High amounts of lead were detected in the blood samples of the workers. The commonest lead related symptoms observed among the workers were malaise (32.1%, fatigue (25.9%, arthralgia (20.9%, abdominal colic (16% and headache (13.6%. Smoking found to be an important contributory factor in the lead related manifestations. An inverse association of practice of hygiene with mean blood lead value was observed among heavily exposed workers. A statistically significant difference was observed between heavily exposed and moderately exposed to lead regarding presence of pallor, malaise symptom, presence of one or more lead related symptoms, blood lead levels, haemoglobin values, etc. Conclusion: A majority of Lead-Acid battery workers (64.19% were highly exposed to lead by their nature of work. The prevalence of toxicity was more among the heavily exposed than the moderately exposed. Minimizing the exposure during the work is very important factor to protect the health of the workers.

  4. Low Contribution of PbO2-Coated Lead Service Lines to Water Lead Contamination at the Tap

    Science.gov (United States)

    To determine if field experience corroborates that formation of stable PbO2 coatings on lead service lines (LSLs) provides an effective lead contamination control strategy, lead profile sampling was undertaken at eight home kitchen taps in three US cities (Newport, Rhode Island; ...

  5. 75 FR 36034 - Advance Notice of Proposed Rulemaking on Lead Emissions From Piston-Engine Aircraft Using Leaded...

    Science.gov (United States)

    2010-06-24

    ...-Engine Aircraft Using Leaded Aviation Gasoline; Extension of Comment Period AGENCY: Environmental... Rulemaking on Lead Emissions From Piston-Engine Aircraft Using Leaded Aviation Gasoline (hereinafter referred...-engine aircraft, or if insufficient information exists, to commence a study. In addition to...

  6. Evaluating the Effects of Full and Partial Lead Service Line Replacement on Lead Levels in Drinking Water.

    Science.gov (United States)

    Trueman, Benjamin F; Camara, Eliman; Gagnon, Graham A

    2016-07-19

    Lead service line replacement (LSLR) is an important strategy for reducing lead exposure via drinking water, but jurisdictional issues can sometimes interfere with full replacement of the lead line. The effects of full and partial LSLR on lead levels were assessed using 5 × 1-L sample profiles collected at more than 100 single-unit residences. Profiles comprised four sequential standing samples (L1-L4) and a free-flowing sample (L5) drawn after a 5 min flush of the outlet. At 45 sites with full lead service lines, 90th percentile lead levels in standing samples ranged from 16.4 to 44.5 μg L(-1) (L1 and L4, respectively). In the free-flowing sample (L5), 90th percentile lead was 9.8 μg L(-1). Within 3 days, full LSLR had reduced L3-L5 lead levels by more than 50%, and within 1 month, lead levels were significantly lower in every liter of the sample profile. Conversely, partial LSLR more than doubled premises plumbing (L1, L2) lead release in the short term and did not reduce L1, L2 lead release in the long term. Even 6 months after partial LSLR, 27% of first-draw lead levels were greater than 15 μg L(-1) (the U.S. EPA action level), compared with 13% pre-replacement.

  7. Influence of social factors on lead exposure and child development

    Energy Technology Data Exchange (ETDEWEB)

    Bornschein, R.L.

    1985-10-01

    A brief overview of current views of child development is provided, with particular attention given to the role the child's physical and social environment plays in influencing the developmental process. Examples from the recent literature are used to illustrate how these factors can influence lead exposure and most importantly how they might interact with lead to ameliorate or exacerbate possible lead effects. An example is provided which demonstrates that failure to control adequately and to adjust the data statistically to correct for the influence of these factors can lead one erroneously to attribute cognitive and behavioral changes to lead. Finally, data from the Cincinnati Prospective Lead Study are presented to illustrate the application of structural equation modeling as a means for unraveling the complex web of sociodemographic, environmental and behavioral influences on childhood lead exposure.

  8. Regional distribution of lead in human milk from Egypt.

    Science.gov (United States)

    Saleh, M A; Ragab, A A; Kamel, A; Jones, J; el-Sebae, A K

    1996-05-01

    Bioaccumulation of lead during chronic exposure and its mobilization and secretion with mother's milk constitute a serious health hazard to the newly born children. Lead levels in human breast milk of 120 Egyptian women representing 20 different governorates throughout Egypt were determined using a graphite furnace Atomic Absorption spectrometer. According to the daily permissible intake (DPI) value established by the WHO of 5.0 micrograms/kg/d in mother's milk, the mean values of lead were around the permissible level in most of the Egyptian governorates. However, lead levels in mother's milk from Alexandria, Assiut and Cairo were significantly higher than the permissible value. Higher lead levels in mother's milk from these governorates may be attributed to heavy automobile traffic using leaded gasoline in addition to the use of lead water pipelines in these areas.

  9. Nucleation and electrolytic deposition of lead on model carbon electrodes

    Science.gov (United States)

    Cericola, D.; Spahr, M.

    2016-08-01

    There is a general consensus in the lead acid battery industry for the use of carbon additives as a functional component in the negative paste to boost the battery performance with regards to charge acceptance and cycle life especially for upcoming automotive and energy storage applications. Several mechanisms are discussed in the scientific literature and the affinity of the carbon surfaces to lead species seems to play a key role. With a set of experiments on model carbon electrodes we gave evidence to the fact that some carbon materials promote spontaneous nucleation of lead crystals. We propose a mechanism such that the carbon, as soon as in a lead containing environment, immobilizes some lead on its surface. Such immobilized lead acts as nucleation seed for the deposition of lead when a current is passed through the material. It is therefore possible to differentiate and select the carbon materials based on their ability to form nucleation seeds.

  10. High temperature superconducting current leads for the Large Hadron Collider

    CERN Document Server

    Ballarino, A

    1999-01-01

    The large hadron collider (LHC) will be equipped with about 8000 superconducting magnets. Some 3380 leads will feed the currents ranging from 60 to 13000 A. To reduce the heat inleak into the liquid helium, CERN aims to use high temperature superconducting material for leads having current ratings between 600 and 13000 A. Specifications have been written for 13000 A current leads, incorporating a high temperature superconducting section, for the main of the LHC, and contracts have been placed with several firms for the supply of prototypes for comparative testing. The leads used for feeding locally the 60 and 120 A dipole orbit correctors will be conventional conduction cooledmagnets resistive leads. An optimized lead of variable cross section has been tested, and an integral design has been initiated. This report describes the design status of the current leads for the LHC, emphasizing, for the different solutions, the principle of optimization and the choice of cooling methods. (8 refs).

  11. Appendectomy due to lead poisoning: a case-report

    Directory of Open Access Journals (Sweden)

    Aghilinejad M

    2008-10-01

    Full Text Available Abstract Background Lead poisoning is a common occupational health hazard in developing countries and many misdiagnoses and malpractices may occur due to unawareness of lead poisoning symptoms. Case presentation We report a case of occupational lead poisoning in an adult battery worker with abdominal colic who initially underwent appendectomy with removal of normal appendix. Later on he was diagnosed with lead poisoning and was treated appropriately with lead chelator (CaNa2EDTA. Conclusion Lead poisoning is frequently overlooked as the differential diagnosis of acute abdomen which may result in unnecessary surgery. Appropriate occupational history taking is helpful in making a correct diagnosis. Occupational lead poisoning is a preventable disorder and a serious challenge for the health and labor authorities in developing countries.

  12. Nano Coated Lead Free Solders for Sustainable Electronic Waste Management

    Directory of Open Access Journals (Sweden)

    K. Arun Vasantha Geethan

    Full Text Available ABSTRACT Lead has been used in a wide range of applications, but in the past decades it became clear that its high toxicity could cause various problems. Studies indicate that exposure to high concentrations of lead can cause harmful damages to humans. To eliminate the usage of lead in electronic products as an initiative towards electronic waste management (e waste, lead free solders were produced with suitable methods by replacing lead. But lead free solders are not preferred as a substitute of lead because they are poor in their mechanical properties such as tensile strength, shear strength and hardness which are ultimately required for a material to resist failure.Nano-Structured materials and coatings offer the potential for Vital improvements in engineering properties based on improvements in physical and mechanical properties resulting from reducing micro structural features by factors of 100 to 1000 times compared to current engineering materials.

  13. Optimization of high-temperature superconductor current leads

    Science.gov (United States)

    Seol, S. Y.; Hull, J. R.; Chyu, M. C.

    Methods to improve the performance of high-temperature superconducting current leads are analyzed. Designs are considered that are inherently safe from burnup, even if the lead enters the normal state. The effect of a tapered lead that takes advantage of the increase in critical current density with decreasing temperature will decrease helium boiloff by about a factor of two for an area ratio of four. A new concept, in which Ag powder is distributed in increasing concentration from the cold end to the hot end of the lead in sintered YBCO, is shown to have comparable performance to that of leads made with Ag-alloy sheaths. Performance of the best inherently safe designs is about one order of magnitude better than that of optimized nonsuperconducting leads. BSCCO leads with Ag-alloy sheaths show improved performance for Au fractions up to about 3%, after which increases in Au fraction yield negligible performance improvement.

  14. Magnetoelectric Interactions in Lead-Based and Lead-Free Composites

    Directory of Open Access Journals (Sweden)

    Shashank Priya

    2011-04-01

    Full Text Available Magnetoelectric (ME composites that simultaneously exhibit ferroelectricity and ferromagnetism have recently gained significant attention as evident by the increasing number of publications. These research activities are direct results of the fact that multiferroic magnetoelectrics offer significant technological promise for multiple devices. Appropriate choice of phases with co-firing capability, magnetostriction and piezoelectric coefficient, such as Ni-PZT and NZFO-PZT, has resulted in fabrication of prototype components that promise transition. In this manuscript, we report the properties of Ni-PZT and NZFO-PZT composites in terms of ME voltage coefficients as a function of frequency and magnetic DC bias. In order to overcome the problem of toxicity of lead, we have conducted experiments with Pb-free piezoelectric compositions. Results are presented on the magnetoelectric performance of Ni-NKN, Ni-NBTBT and NZFO-NKN, NZFO-NBTBT systems illustrating their importance as an environmentally friendly alternative.

  15. Expansion of chemical space for collaborative lead generation and drug discovery: the European Lead Factory Perspective.

    Science.gov (United States)

    Karawajczyk, Anna; Giordanetto, Fabrizio; Benningshof, Jorg; Hamza, Daniel; Kalliokoski, Tuomo; Pouwer, Kees; Morgentin, Remy; Nelson, Adam; Müller, Gerhard; Piechot, Alexander; Tzalis, Dimitrios

    2015-11-01

    High-throughput screening (HTS) represents a major cornerstone of drug discovery. The availability of an innovative, relevant and high-quality compound collection to be screened often dictates the final fate of a drug discovery campaign. Given that the chemical space to be sampled in research programs is practically infinite and sparsely populated, significant efforts and resources need to be invested in the generation and maintenance of a competitive compound collection. The European Lead Factory (ELF) project is addressing this challenge by leveraging the diverse experience and know-how of academic groups and small and medium enterprises (SMEs) engaged in synthetic and/or medicinal chemistry. Here, we describe the novelty, diversity, structural complexity, physicochemical characteristics and overall attractiveness of this first batch of ELF compounds for HTS purposes.

  16. Lead in Drinking Water in Slovenian Kindergartens and Schools

    Directory of Open Access Journals (Sweden)

    Bitenc K.

    2013-04-01

    Full Text Available The purpose of the work is to determine how high are the concentrations of lead in drinking water in older Slovenian kindergartens and primary schools and to demonstrate that lead can also migrate from newer materials used for the construction of water distribution networks. To determine the concentrations of lead in drinking water, it is needed to take 250 ml of drinking water that stood in the pipes from 8 to 18hours. It is also applied a method for determining the migration from different materials. An old lead pipe is utilized, as well as new materials (PEX-Al-PEX, copper, galvanized pipes and stainless steel pipes. Sampling showed that 6 samples of 39 had levels of lead higher than 10 µg/l, two of them highly exceeded that level. Negative correlation between the level of pH and concentration of lead in drinking water is moderate. Implementation of lead migration from various types of pipes demonstrated the migration from galvanized pipes in all simulants. Furthermore, the migration of lead from galvanized pipes is dependent on water temperature. The migration was confirmed from the lead pipe as expected. Study points to a problem with elevated concentrations of lead in drinking water faced by older kindergartens and primary schools in Slovenia. All concentrations of lead after flushing the pipes were below the 10 µg/l, which shows that the most effective action to lower the concentrations of lead is flushing the water pipes. For the purposes of national monitoring of drinking water is necessary to apply a better method for determining lead levels in drinking water namely the sampling of water that stood in the pipes at least 8 to 18 hours. This study has demonstrated the migration of lead from galvanized pipes. This material is also installed in 54 % of kindergartens and primary schools that participated in the study.

  17. Lead--the toxic metal to stay with human.

    Science.gov (United States)

    Srianujata, S

    1998-07-01

    Lead has been known to be toxic to most living things at high dose. It is found naturally in earth and present in almost all parts of the environment, such as foods, air, water, dust, soil, paint, and tissues of living organisms including human. This metal is being used in various aspects including the manufacturing of storage batteries, production of chemicals, paints and gasoline additives. It is also used to make various metal products, e.g. sheet lead, solder, and pipes. Human exposure to lead is mainly from foods and other environments. However, it is expected that exposure to environmental lead is normally excessive and produces toxic effects. The well-known and excessive environmental exposures are air of industrial and heavy traffic areas. Use of leaded gasoline has caused the main lead pollution for years in almost every big city. Therefore, city inhabitants normally exposed to lead much more than those who live in the rural area. The most vulnerable groups at risk to lead exposure are fetuses and preschool age children. Young children in the 2-3 year-old age may be the most at risk for exposure to contaminated soil. Adults are affected when exposure is excessive in the working place and causing lead poisoning. Toxicities are mainly on heme biosynthesis, neurological effects including encepharopathy, peripheral neuropathy, and most importantly on I.Q. deficits. It also affects renal tissues to produce acute and chronic nephropathy and elevated blood pressure. There are studies of lead exposure of various means and the effects on human health, both in children and adults. Lead in environment and human exposure are expected to stay with us for long to come, due the still required lead use in many fields, particularly the use of lead in storage batteries and others. The magnitude of exposure will depend solely on the control of use by not allowing the contamination of lead in our environment to be excessive.

  18. The importance of lead-free electronics processes

    Energy Technology Data Exchange (ETDEWEB)

    Meltzer, M

    1999-10-21

    The Environmental Protection Agency (EPA) is placing increased importance on reducing lead-bearing wastes. Toward this end, the EPA has proposed that reporting thresholds for the Toxic Release Inventory (TRI) be lowered to ten pounds of lead content per year. The US electronics industry is also placing a high priority on lead reduction or elimination. The Association of Connecting Electronics Industries, which is the major trade association for electronics packaging, including printed circuit (PC) board manufacturers, has launched a lead-free initiative that seeks to eliminate lead in solder, in PC board etch resists and finish coats, and as tinning for component leads. Europe and Japan are also considering various regulations that will phase out lead in the next few years. In response to EPA and electronics industry priorities, the DOE complex will soon need to address lead phase-out issues. LLNL is now developing approaches for eliminating lead from PC board etch-resist operations. LLNL is seeking funding to continue this work and to eliminate other major uses of lead in electronics operations, particularly in hot-air solder leveling as a PC board finish, and tin-lead solder for component assembly operations. LLNL seeks to take a proactive leadership role in the DOE complex with respect to the elimination of lead. The envisioned lead-elimination project will be approximately two years in length. During the first year, lead-free etch resists and finish coats will be analyzed, and the best ones identified for electronics assembly and PC board fabrication. During the second year, lead-free solders will be examined and tested for compatibility with alternative PC board finish coats. Cost avoidance opportunities resulting from lead elimination include avoided TRI reporting expenses and reduction in PC board fabrication-related wastes through implementation of more efficient fabrication processes. Integrated Safety Management considerations are also relevant. Handling

  19. Toxic exposure of songbirds to lead in the Southeast Missouri Lead Mining District

    Science.gov (United States)

    Beyer, W. Nelson; Franson, J. Christian; French, John B.; May, Thomas; Rattner, Barnett A.; Shearn-Bochsler, Valerie I.; Warner, Sarah E.; Weber, John; Mosby, David

    2013-01-01

    Mining and smelting in the Southeast Missouri Lead Mining District has caused widespread contamination of soils with lead (Pb) and other metals. Soils from three study sites sampled in the district contained from approximately 1,000–3,200 mg Pb/kg. Analyses of earthworms [33–4,600 mg Pb/kg dry weight (dw)] collected in the district showed likely high Pb exposure of songbirds preying on soil organisms. Mean tissue Pb concentrations in songbirds collected from the contaminated sites were greater (p < 0.05) than those in songbirds from reference sites by factors of 8 in blood, 13 in liver, and 23 in kidney. Ranges of Pb concentrations in livers (mg Pb/kg dw) were as follows: northern cardinal (Cardinalis cardinalis) = 0.11–3.0 (reference) and 1.3–30 (contaminated) and American robin (Turdus migratorius) = 0.43–8.5 (reference) and 7.6–72 (contaminated). Of 34 adult and juvenile songbirds collected from contaminated sites, 11 (32 %) had hepatic Pb concentrations that were consistent with adverse physiological effects, 3 (9 %) with systemic toxic effects, and 4 (12 %) with life-threatening toxic effects. Acid-fast renal intranuclear inclusion bodies, which are indicative of Pb poisoning, were detected in kidneys of two robins that had the greatest renal Pb concentrations (952 and 1,030 mg/kg dw). Mean activity of the enzyme delta-aminolevulinic acid dehydratase (ALAD) in red blood cells, a well-established bioindicator of Pb poisoning in birds, was decreased by 58–82 % in songbirds from the mining sites. We conclude that habitats within the mining district with soil Pb concentrations of ≥1,000 mg Pb/kg are contaminated to the extent that they are exposing ground-feeding songbirds to toxic concentrations of Pb.

  20. Vector boson production in proton-lead and lead-lead collisions at the LHC and its impact on nCTEQ15 PDFs

    CERN Document Server

    Kusina, A; Clark, D B; Godat, E; Jezo, T; Kovarik, K; Olness, F I; Schienbein, I; Yu, J Y

    2016-01-01

    We provide a comprehensive comparison of W/Z vector boson production data in proton-lead and lead-lead collisions at the LHC with predictions obtained using the nCTEQ15 PDFs. We identify the measurements which have the largest potential impact on the PDFs, and estimate the effect of including these data using a Monte Carlo reweighting method. We find this data set can provide information about both the nuclear corrections and the heavy flavor (strange) PDF components. As the proton flavor determination is dependent on nuclear corrections (from heavy target DIS, for example), this information can also help improve the proton PDFs.

  1. The scientific basis for chelation: animal studies and lead chelation.

    Science.gov (United States)

    Smith, Donald; Strupp, Barbara J

    2013-12-01

    This presentation summarizes several of the rodent and non-human studies that we have conducted to help inform the efficacy and clinical utility of succimer (meso-2,3-dimercaptosuccincinic acid) chelation treatment. We address the following questions: (1) What is the extent of body lead, and in particular brain lead reduction with chelation, and do reductions in blood lead accurately reflect reductions in brain lead? (2) Can succimer treatment alleviate the neurobehavioral impacts of lead poisoning? And (3) does succimer treatment, in the absence of lead poisoning, produce neurobehavioral deficits? Results from our studies in juvenile primates show that succimer treatment is effective at accelerating the elimination of lead from the body, but chelation was only marginally better than the complete cessation of lead exposure alone. Studies in lead-exposed adult primates treated with a single 19-day course of succimer showed that chelation did not measurably reduce brain lead levels compared to vehicle-treated controls. A follow-up study in rodents that underwent one or two 21-day courses of succimer treatment showed that chelation significantly reduced brain lead levels, and that two courses of succimer were significantly more efficacious at reducing brain lead levels than one. In both the primate and rodent studies, reductions in blood lead levels were a relatively poor predictor of reductions in brain lead levels. Our studies in rodents demonstrated that it is possible for succimer chelation therapy to alleviate certain types of lead-induced behavioral/cognitive dysfunction, suggesting that if a succimer treatment protocol that produced a substantial reduction of brain lead levels could be identified for humans, a functional benefit might be derived. Finally, we also found that succimer treatment produced lasting adverse neurobehavioral effects when administered to non-lead-exposed rodents, highlighting the potential risks of administering succimer or other metal

  2. Assessment of soil lead exposure in children in Shenyang, China.

    Science.gov (United States)

    Ren, H M; Wang, J D; Zhang, X L

    2006-11-01

    Soil lead pollution is serious in Shenyang, China. The paper brings together the soil work, the bioaccessibility, and the blood lead data to assess the soil lead exposure in children in Shenyang, China. Approximately 15.25% of the samples were above China Environment Protection Agency guideline concentration for soil Pb to protect human from health risk (350 mgkg(-1)). Pb concentrations varied among use scenarios. The main lead contamination sources are industry emission and automobile exhaust. Bioaccessibility also varied among use scenarios. Children, who ingested soil from industrial area, public parks, kindergarten playground, and commercial area, are more susceptible to soil lead toxicity. The industrial area soil samples presented higher bioaccessibility compared to the other use scenario soil samples contaminated by automobile exhaust. The result also suggested a most significant linear relationship between the level of Pb contamination and the amount of Pb mobilized from soil into ingestion juice. Soil pH seemed to have insignificant influence on bioaccessibility in the present study. Bioaccessibility was mainly controlled by other factors that are not investigated in this study. A linear relationship between children blood lead and soil intestinal bioaccessibility was present in the study. Children who are 4-5 years old are more likely to demonstrate the significant relationship between soil lead bioaccessibility and blood lead as their behaviors place them at greatest risk of soil lead toxicity, and their blood lead levels are more likely to represent recent exposure.

  3. Significance of lead aVR in acute coronary syndrome

    Institute of Scientific and Technical Information of China (English)

    Akira; Tamura

    2014-01-01

    The 12-lead electrocardiogram(ECG)is a crucial tool in the diagnosis and risk stratification of acute coronary syndrome(ACS).Unlike other 11 leads,lead aVR has been long neglected until recent years.However,recent investigations have shown that an analysis of ST-segment shift in lead aVR provides useful information on the coronary angiographic anatomy and risk stratification in ACS.ST-segment elevation in lead aVR can be caused by(1)transmural ischemia in the basal part of the interventricular septum caused by impaired coronary blood flow of the first major branch originating from the left anterior descending coronary artery;(2)transmural ischemia in the right ventricular outflow tract caused by impaired coronary blood flow of the large conal branch originating from the right coronary artery;and(3)reciprocal changes opposite to ischemic or non-ischemic ST-segment depression in the lateral limb and precordial leads.On the other hand,ST-segment depression in lead aVR can be caused by transmural ischemia in the inferolateral and apical regions.It has been recently shown that an analysis of T wave in lead aVR also provides useful prognostic information in the general population and patients with prior myocardial infarction.Cardiologists should pay more attention to the tracing of lead aVR when interpreting the12-lead ECG in clinical practice.

  4. Costs of IQ Loss from Leaded Aviation Gasoline Emissions.

    Science.gov (United States)

    Wolfe, Philip J; Giang, Amanda; Ashok, Akshay; Selin, Noelle E; Barrett, Steven R H

    2016-09-06

    In the United States, general aviation piston-driven aircraft are now the largest source of lead emitted to the atmosphere. Elevated lead concentrations impair children's IQ and can lead to lower earnings potentials. This study is the first assessment of the nationwide annual costs of IQ losses from aircraft lead emissions. We develop a general aviation emissions inventory for the continental United States and model its impact on atmospheric concentrations using the community multi-scale air quality model (CMAQ). We use these concentrations to quantify the impacts of annual aviation lead emissions on the U.S. population using two methods: through static estimates of cohort-wide IQ deficits and through dynamic economy-wide effects using a computational general equilibrium model. We also examine the sensitivity of these damage estimates to different background lead concentrations, showing the impact of lead controls and regulations on marginal costs. We find that aircraft-attributable lead contributes to $1.06 billion 2006 USD ($0.01-$11.6) in annual damages from lifetime earnings reductions, and that dynamic economy-wide methods result in damage estimates that are 54% larger. Because the marginal costs of lead are dependent on background concentration, the costs of piston-driven aircraft lead emissions are expected to increase over time as regulations on other emissions sources are tightened.

  5. Environmental lead exposure as a risk for childhood aplastic anemia.

    Science.gov (United States)

    Ahamed, M; Akhtar, M J; Verma, S; Kumar, A; Siddiqui, M K J

    2011-01-01

    Concern about environmental lead exposure as a significant public health threat has increased as evidence has accumulated regarding adverse health effects at successively lower levels. Aplastic anemia is a hematological disorder of unknown etiology with a high lethality rate. Lead is a known toxicant for the hematopoietic system. Oxidative stress appears to be the possible mode of lead toxicity. We evaluated the effects of blood lead level on oxidative stress parameters in children suffering from aplastic anemia disease. Seventeen children with aplastic anemia disease (15 male and 2 female, age 3-12 y) were recruited in the study group. Fifty one healthy children (45 male and 6 female, age 3-12 y) having normal blood profiles and not suffering from any chronic disease(s) were used as controls. Blood lead level and oxidative stress parameters were determined. Mean blood lead level was significantly higher while δ-aminolevulinic acid dehydratase (δ-ALAD) activity, a biomarker for lead exposure was significantly lower in the study group as compared to the control group (p lead levels with δ-ALAD (r = -0.45; p lead induces oxidative stress in children suffering from aplastic anemia. Lead-induced oxidative stress as an underlying mechanism for aplastic anemia warrants further research.

  6. Correlation between biochemical indicators of lead exposure and semen quality in a lead-poisoned firearms instructor

    Energy Technology Data Exchange (ETDEWEB)

    Fisher-Fischbein, J.; Fischbein, A.; Melnick, H.D.; Bardin, C.W.

    1987-02-13

    Lead poisoning is a disease of great public health concern, particularly because of the hazards that lead can pose to children as a result of ingestion of lead-based paint and perhaps as a consequence of the effects of lead pollution of the ambient air. However, lead poisoning is also a common occupational disease among adults. Persons who work as instructors at indoor firing ranges are likewise at high risk for occupational lead poisoning. The typical biochemical features of lead poisoning include inhibition of heme synthesis manifested by elevated levels of erythrocyte protoporphyrin and decreased activity of sigma-aminolevulinic acid dehydratase. Reproductive effects of lead have been reported in both men and women, but these effects rarely present themselves as practical clinical problems in occupational medicine practice. The current Department of Labor standard for occupational exposure to inorganic lead has been promulgated with special emphasis on the protection of the worker from damage to the reproductive system. The authors had the opportunity of measuring biologic indicators of lead exposure and of assessing semen quality in a firearms instructor with lead poisoning and infertility, who was treated and who fathered a child. They report herein the results of these longitudinal observations.

  7. Effects of lead-contaminated sediment on Rana sphenocephala tadpoles

    Science.gov (United States)

    Sparling, D.W.; Krest, S.K.; Ortiz-Santaliestra, M.

    2006-01-01

    We exposed larval southern leopard frogs (Rana sphenocephala) to lead-contaminated sediments to determine the lethal and sublethal effects of this metal. Tadpoles were laboratory-raised from early free-swimming stage through metamorphosis at lead concentrations of 45, 75, 180, 540, 2360, 3940, 5520, and 7580 mg/kg dry weight in sediment. Corresponding pore water lead concentrations were 123, 227, 589, 1833, 8121, 13,579, 19,038, and 24,427 ug/L. Tadpoles exposed to lead concentrations in sediment of 3940 mg/kg or higher died within 2 to 5 days of exposure. At lower concentrations, mortality through metamorphosis ranged from 3.5% at 45 mg/kg lead to 37% at 2360 mg/kg lead in sediment. The LC50 value for lead in sediment was 3728 mg/kg (95% CI=1315 to 72,847 mg/kg), which corresponded to 12,539 ug/L lead in pore water (95% CI= 4000 to 35,200 ug/L). Early growth and development were depressed at 2,360 mg/kg lead in sediment (8100 ug/L in pore water) but differences were not evident by the time of metamorphosis. The most obvious effect of lead was its pronounced influence on skeletal development. Whereas tadpoles at 45 mg/kg lead in sediment did not display permanent abnormalities, skeletal malformations increased in frequency and severity at all higher lead concentrations. By 2360 mg/kg, 100% of surviving metamorphs displayed severe spinal problems, reduced femur and humerus lengths, deformed digits, and other bone malformations. Lead concentrations in tissues correlated positively with sediment and pore water concentrations.

  8. The “curved lead pathway” method to enable a single lead to reach any two intracranial targets

    Science.gov (United States)

    Ding, Chen-Yu; Yu, Liang-Hong; Lin, Yuan-Xiang; Chen, Fan; Lin, Zhang-Ya; Kang, De-Zhi

    2017-01-01

    Deep brain stimulation is an effective way to treat movement disorders, and a powerful research tool for exploring brain functions. This report proposes a “curved lead pathway” method for lead implantation, such that a single lead can reach in sequence to any two intracranial targets. A new type of stereotaxic system for implanting a curved lead to the brain of human/primates was designed, the auxiliary device needed for this method to be used in rat/mouse was fabricated and verified in rat, and the Excel algorithm used for automatically calculating the necessary parameters was implemented. This “curved lead pathway” method of lead implantation may complement the current method, make lead implantation for multiple targets more convenient, and expand the experimental techniques of brain function research.

  9. Influence of experimental distemper infection on the distribution of lead in dogs previously subacutely intoxicated with lead carbonate

    Energy Technology Data Exchange (ETDEWEB)

    White, D.J.; Marshall, A.J.; McLeod, S.

    1975-01-01

    The ability of experimental canine distemper infection to mobilize body lead deposits has been studied in Beagle dogs previously subacutely intoxicated with lead carbonate. For comparative purposes dogs were included which had either received lead only or distemper only or remained undosed. It was found that in dogs predosed with lead, distemper infection resulted in a significant increase in lead levels in blood and urine; this coincided with the peak body temperatures reached on the third day post infection. It was also found that the lead content of the liver and bone of these dogs was considerably higher than that of dogs receiving lead alone; at the same time bone phosphorus showed a marked decrease while bone calcium values remained similar to undosed controls.

  10. Lead contamination in Uruguay: the "La Teja" neighborhood case.

    Science.gov (United States)

    Mañay, Nelly; Cousillas, Adriana Z; Alvarez, Cristina; Heller, Teresa

    2008-01-01

    Lead, ubiquitous in the environment as a result of mining and industrialization, is found as a contaminant in humans although it has no known physiological function there. Lead-exposed children are known to be the population with the highest potential health risks. The recommended biomarker to assess environmental lead exposure in animals is lead level in blood. Before 2001, the Department of Toxicology and Environmental Hygiene was the only team to produce human monitoring data on Uruguayan populations (Manay 2001a,b; Mañay et al. 1999). Lead pollution in Uruguay first received official attention during the 2001 La Teja poisoning episode. It was in the La Teja neighbourhood of Montevideo that high BLL were found in children (as high as 20 microg/dL), prompting corrective responses from Health and Environmental authorities. Growing awareness of environmental lead pollution and consequential human health effects from that event, resulted in public debate and demands for solutions from Health and Environmental authorities. Citizens demanded public disclosure of information concerning lead pollution and wanted action to address contaminated Uruguayan sites. In response, the Ministry of Health assembled an interinstitutional multidisciplinary committee, with delegates from health, environmental, labor, educational, and social security authorities, as well as community nongovernmental organizations (NGOs), among others. The University of the Republic was designated to serve as the main responsible entity for technical advice and support. After 2001, new research on lead pollution was undertaken and included multidisciplinary studies with communities in response to health risk alerts. The main emphasis was placed on children exposed to environmental lead. Major sources of Uruguayan lead contamination, similar to those in other developing countries, result from metallurgical industries, lead-acid battery processing, lead wire and pipe factories, metal foundries, metal

  11. Identification of sources of lead exposure in French children by lead isotope analysis: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Lucas Jean-Paul

    2011-08-01

    Full Text Available Abstract Background The amount of lead in the environment has decreased significantly in recent years, and so did exposure. However, there is no known safe exposure level and, therefore, the exposure of children to lead, although low, remains a major public health issue. With the lower levels of exposure, it is becoming more difficult to identify lead sources and new approaches may be required for preventive action. This study assessed the usefulness of lead isotope ratios for identifying sources of lead using data from a nationwide sample of French children aged from six months to six years with blood lead levels ≥25 μg/L. Methods Blood samples were taken from 125 children, representing about 600,000 French children; environmental samples were taken from their homes and personal information was collected. Lead isotope ratios were determined using quadrupole ICP-MS (inductively coupled plasma - mass spectrometry and the isotopic signatures of potential sources of exposure were matched with those of blood in order to identify the most likely sources. Results In addition to the interpretation of lead concentrations, lead isotope ratios were potentially of use for 57% of children aged from six months to six years with blood lead level ≥ 25 μg/L (7% of overall children in France, about 332,000 children, with at least one potential source of lead and sufficiently well discriminated lead isotope ratios. Lead isotope ratios revealed a single suspected source of exposure for 32% of the subjects and were able to eliminate at least one unlikely source of exposure for 30% of the children. Conclusions In France, lead isotope ratios could provide valuable additional information in about a third of routine environmental investigations.

  12. Microdistribution of lead in bone: A new approach

    Energy Technology Data Exchange (ETDEWEB)

    Jones, K.W. [Brookhaven National Lab., Upton, NY (United States); Bockman, R.S. [Cornell Univ., New York, NY (United States). Medical Coll.; Bronner, F. [Connecticut Univ. Health Center, Farmington, CT (United States)

    1991-12-31

    A knowledge of the microdistribution of lead in bone is important in order to understand the mechanisms for accumulation and release of lead. The availability of the synchrotron x-ray microscope for sensitive measurements of bone content and distribution of lead provides a valuable tool which, when combined with kinetic, balance, and tissue measurements, can lead to better evaluation of lead toxicity. It may also provide the basis for the development of a suitable model of how lead behaves in the human body. An outline of an experimental protocol for exploitation of the x-ray microscope is given, along with synchrotron x-ray microscope measurements of the distribution of gallium in rat bone that demonstrate the feasibility of the experimental approach.

  13. Microdistribution of lead in bone: A new approach

    Energy Technology Data Exchange (ETDEWEB)

    Jones, K.W. (Brookhaven National Lab., Upton, NY (United States)); Bockman, R.S. (Cornell Univ., New York, NY (United States). Medical Coll.); Bronner, F. (Connecticut Univ. Health Center, Farmington, CT (United States))

    1991-01-01

    A knowledge of the microdistribution of lead in bone is important in order to understand the mechanisms for accumulation and release of lead. The availability of the synchrotron x-ray microscope for sensitive measurements of bone content and distribution of lead provides a valuable tool which, when combined with kinetic, balance, and tissue measurements, can lead to better evaluation of lead toxicity. It may also provide the basis for the development of a suitable model of how lead behaves in the human body. An outline of an experimental protocol for exploitation of the x-ray microscope is given, along with synchrotron x-ray microscope measurements of the distribution of gallium in rat bone that demonstrate the feasibility of the experimental approach.

  14. Identifying Lead Markets in the European Automotive Industry

    DEFF Research Database (Denmark)

    Cleff, Thomas; Grimpe, Christoph; Rammer, Christian

    2015-01-01

    of excellence in technology and interaction among users and producers, the lead market approach focuses on the role of demand characteristics. Based on the concept of innovation design, a lead market is defined as a country where customers prefer that design which subsequently becomes the globally dominant......This paper presents an indicator-based methodology to identify lead markets in the European automotive industry. The lead market approach tries to explain why certain countries are better positioned than others for developing and launching new products. While much research stresses the role...... design. We use an indicator-based approach which has been successfully employed for individual products as well as for various industries in order to identify lead markets in the European automotive industry. Employing five lead market factors, our results show that the EU is by far no homogeneous market...

  15. Nephrotoxic effects of lead nitrate in Rana ridibunda.

    Science.gov (United States)

    Loumbourdis, N S

    2003-09-01

    The impact of lead (Pb) on kidney histopathology of the frog Rana ridibunda was investigated. Female frogs were exposed for 4, 10 and 30 days to 14 ppm lead (as lead nitrate). All the lead concentrations and many histological changes were time dependent. Light microscopy of kidney revealed morphological changes mainly in the proximal convoluted tubule (PCT) cells. The most severe changes such as vacuolation, Perl's stained material, infiltration, brush border destruction and proximal tubule damage were detected in the animals exposed for 10 and 30 days. Karyomegaly was highest at 10-days exposure, probably as a result of intense stress caused by the lead. Some PCT in the 30-days-exposed animals were von Kossa's method positive, suggesting the presence of calcium. The possibility is discussed that some of these changes, such as karyomegaly and intranuclear inclusions, might be preneoplastic if lead was supplied at high concentrations and for long time.

  16. Psychological performance of subjects with low exposure to lead

    Energy Technology Data Exchange (ETDEWEB)

    Haenninen, H.; Hernberg, S.; Mantere, P.; Vesanto, R.; Jalkanen, M.

    1978-10-01

    In a study of the effects of low lead exposure on psychological performance, 49 exposed workers and 24 controls were given a psychological test battery. All the lead workers had been under regular monitoring during their entire exposure time, and only workers whose maximal blood lead concentration had never exceeded 70 microgram/100 ml were included in the study. The most important finding was a significant relationship between impaired psychological performance and lead uptake within the exposed group. The performances that were most affected by lead depended on visual intelligence and visual-motor functions. Age and neuroticism did not explain these relationships. Considering that no single blood lead concentration had ever exceeded 70 microgram/100 ml, these findings indicate that the threshold for impaired performance lies below that level.

  17. Nephrotoxic effects of lead nitrate in Rana ridibunda

    Energy Technology Data Exchange (ETDEWEB)

    Loumbourdis, N.S. [Department of Zoology, University of Thessaloniki, 54124, Thessaloniki (Greece)

    2003-09-01

    The impact of lead (Pb) on kidney histopathology of the frog Rana ridibunda was investigated. Female frogs were exposed for 4, 10 and 30 days to 14 ppm lead (as lead nitrate). All the lead concentrations and many histological changes were time dependent. Light microscopy of kidney revealed morphological changes mainly in the proximal convoluted tubule (PCT) cells. The most severe changes such as vacuolation, Perl's stained material, infiltration, brush border destruction and proximal tubule damage were detected in the animals exposed for 10 and 30 days. Karyomegaly was highest at 10-days exposure, probably as a result of intense stress caused by the lead. Some PCT in the 30-days-exposed animals were von Kossa's method positive, suggesting the presence of calcium. The possibility is discussed that some of these changes, such as karyomegaly and intranuclear inclusions, might be preneoplastic if lead was supplied at high concentrations and for long time. (orig.)

  18. Progress in engineering high strain lead-free piezoelectric ceramics

    Directory of Open Access Journals (Sweden)

    Serhiy O Leontsev and Richard E Eitel

    2010-01-01

    Full Text Available Environmental concerns are strongly driving the need to replace the lead-based piezoelectric materials currently employed as multilayer actuators. The current review describes both compositional and structural engineering approaches to achieve enhanced piezoelectric properties in lead-free materials. The review of the compositional engineering approach focuses on compositional tuning of the properties and phase behavior in three promising families of lead-free perovskite ferroelectrics: the titanate, alkaline niobate and bismuth perovskites and their solid solutions. The 'structural engineering' approaches focus instead on optimization of microstructural features including grain size, grain orientation or texture, ferroelectric domain size and electrical bias field as potential paths to induce large piezoelectric properties in lead-free piezoceramics. It is suggested that a combination of both compositional and novel structural engineering approaches will be required in order to realize viable lead-free alternatives to current lead-based materials for piezoelectric actuator applications.

  19. Experimental lead poisoning in Turkey Vultures, Cathartes aura

    Science.gov (United States)

    Carpenter, J.W.; Pattee, O.H.; Fritts, S.H.; Rattner, B.A.; Wiemeyer, Stanley N.; Royle, J. Andrew; Smith, M.R.

    2003-01-01

    Lead-induced mortality appears to have been a major factor in the decline of the California condor, Gymnogyps californianus. We orally dosed turkey vultures (Cathartes aura) with BB-sized lead shot from January 1988 through July 1988 to determine physiological response (delta-aminolevulinic acid dehydratase inhibition, erythrocyte protoporphyrin levels, anemia), diagnostic tissue lead concentrations (blood, liver, and kidney), and comparative sensitivity of this species. Two turkey vultures died and two became so intoxicated they were euthanized. Overall, responses of measured parameters were comparable to other species exposed to lead although there was considerable individual variation. Survival time (143-211 days), even with the large number of shot and constant redosing, was much longer than reported for other species of birds, suggesting considerable tolerance by turkey vultures to the deleterious effects of lead ingestion. Based on these observations, turkey vultures appear to be poor models for assessing the risk of lead poisoning to California condors or predicting their physiological response.

  20. Lead Tolerance and Accumulation in White Poplar Cultivated In Vitro

    Directory of Open Access Journals (Sweden)

    Branislav Kovačević

    2013-06-01

    Full Text Available Background and Purpose: This paper analyses the lead tolerance and accumulation in white poplar genotypes in vitro, in order to optimize genotype evaluation and other procedures in their implementation in phytoremediation projects and landscaping in areas endangered by lead accumulation. Material and Methods: The lead tolerance and accumulation of five white poplar genotypes after 35 days in vitro cultivation on media supplemented with lead was examined. The following Pb(NO32 concentrations were used: 0, 10-6, 10-5, 10-4 and 10-3 M. Tolerance analysis (described by tolerance indices was based on morphological parameters, biomass accumulation and the content of photosynthetic pigments, while lead accumulation was described by shoot lead accumulation and shoot lead content. Results and Conclusions: The chosen lead concentrations appeared not to be lethal. Moreover, the obtained results showed that the tested lead concentrations had a positive effect on: number of formed roots, shoot moisture content and shoot height. The best differentiation among the examined genotypes was gained by the tolerance index based on the shoot height on 10-4 M Pb(NO32. The shoot lead accumulation and shoot lead content significantly increased on 10-4 and 10-3 M Pb(NO32 media. Thus, the concentration of 10-4 M Pb(NO32 is recommended for further research. Two examined genotypes of horticultural value (LCM and LBM achieved a significantly higher lead shoot content compared to the wide spread genotype “Villafranca” (almost 200% and 125% higher, respectively.