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Sample records for synthetic studies leading

  1. In vitro and in vivo studies of lead immobilization by synthetic hydroxyapatite

    International Nuclear Information System (INIS)

    Arnich, Nathalie; Lanhers, Marie-Claire; Laurensot, Franck; Podor, Renaud; Montiel, Antoine; Burnel, Daniel

    2003-01-01

    Lead immobilization by solid hydroxyapatite significantly reduces lead concentration and bioavailability in water. - Apatite appears a useful compound for removing lead from water, due to its ability to immobilize the metal by precipitation. In dilute solution, dissolved hydroxyapatite [HA, Ca 10 (PO 4 ) 6 (OH) 2 ] provided phosphates that were reactive with aqueous lead (molar ratio HA/Pb=1/10) forming precipitates at around pH 6. These dissolved at a more acidic pH (3). Solid HA in contact with Pb 2+ ions, led to the formation of pyromorphite [Pb 10 (PO 4 ) 6 (OH) 2 ], identified by X-ray diffraction and insoluble at pH tested (3-8). The amount of pyromorphite increased with the weight ratio of HA/Pb. When this one increased from 1 to 1000, lead precipitated as pyromorphite rose from 19 to 99%. In vivo experiments on rats confirmed the in vitro results. In fact, lead bioavailability assessed by intestinal perfusion was unchanged in the presence of dissolved HA, whereas it was significantly lower in the presence of solid HA, evaluated by gastric intubation, at a weight ratio equal to 10 (amount of lead absorbed decreased by 60%). Apatite could be an effective means of immobilizing lead in drinking or sewage, since accidental pyromorphite ingestion does not yield bioavailable lead

  2. News: Synthetic biology leading to specialty chemicals

    Science.gov (United States)

    Synthetic biology can combine the disciplines of biology, engineering, and chemistry productively to form molecules of great scientific and commercial value. Recent advances in the new field are explored for their connection to new tools that have been used to elucidate productio...

  3. News: Synthetic biology leading to specialty chemicals ...

    Science.gov (United States)

    Synthetic biology can combine the disciplines of biology, engineering, and chemistry productively to form molecules of great scientific and commercial value. Recent advances in the new field are explored for their connection to new tools that have been used to elucidate production pathways to a wide variety of chemicals generated by microorganisms. The selection and enhancement of microbiological strains through the practice of strain engineering enables targets of design, construction, and optimization. This news column aspires to cover recent literature relating to the development and understanding of clean technology.

  4. 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.

  5. Optimization of Lead Removal via Napier Grass in Synthetic Brackish Water using Response Surface Model

    Science.gov (United States)

    Hongsawat, P.; Suttiarporn, P.; Wutsanthia, K.; Kongsiri, G.

    2018-03-01

    The efficiency of the lead (Pb) phytoremediation by Napier grass was studied on the plant’s growth and plant’s tolerance on the Pb toxicity in synthetic brackish water. It was found that the plant was high tolerance to high level of Pb concentration (10 mg/l) in synthetic brackish water. Which revealed on the possibilities of plant’s growth under the presence of Pb contaminated condition. According to the Pb removal efficiency, the highest one (88.63±4.9%) was found at 10 ppm Pb concentration, 0.3 g/l NaCl concentration during the period 45 day. However, this study investigated the optimum condition for lead (Pb) removal from synthetic brackish water using phytoremediation treatment with Napier grass through a Box-Behnken Design. Three operational variables, i.e. Pb concentration (1, 5.5, 10 mg/l), NaCl (0.1, 0.3, 0.5 g/l) and period time (7, 26, 45 day), were determined. The results were provided evidence that the highest Pb removal efficiency (93.56%) from synthetic brackish water via Napier grass was Pb and NaCl concentration at 10 mg/l and 0.5 g/l during 45 day.

  6. Study of seed for synthetical quartz

    International Nuclear Information System (INIS)

    Suzuki, C.K.; Torikai, D.

    1988-01-01

    Natural quartz blocks for seed (synthetic quartz technology) were studied by using various characterization techniques, such as X-ray topography, optical micrography, inspectoscopy, polariscopy and conoscopy, and etching. One of the most commonly found defect is the electrical or Dauphine twin. In The present research, we have developed a methodology to obtain a highly perfect seed for the synthetic quartz industries. (author) [pt

  7. Evaluation of dum palm kernel activated carbon in chromium and lead adsorption from synthetic waste water

    Directory of Open Access Journals (Sweden)

    HI Mohammed

    2016-09-01

    Full Text Available This study aimed at the co-current removal of chromium and lead ions from synthetic waste water using dum palm kernel activated carbon. The adsorption experiment was conducted by varying time, pH and concentrations of the simulated solution. The data obtained were analyzed, and the best conditions for the uptake were at pH of 6, equilibrium time of 40 minutes. The two best isotherms models for the adsorption system were Sip, and Dubinin–Radushkevich, models respectively. Based on the Temkin adsorption energy calculated as 9.5793 and 0.4997 J/mol, the uptake of lead and chromium were chemisorption and physico-sorption, respectively. The maximum uptake calculated from Dubinin–Radushkevich plots were 14.1696 and 7.7191 mg/g, for lead and chromium, respectively.International Journal of Environment Vol.5(3 2016, pp.104-118

  8. Evaluation of natural clay Brasgel as adsorbent in removal of lead in synthetic waste water

    International Nuclear Information System (INIS)

    Lima, W.S.; Rodrigues, M.G.F.; Mota, M.F.; Patricio, A.C.L.; Silva, M.M.

    2012-01-01

    The smectite clays have high adsorption capacity and cation exchange. Due to its chemical and physical characteristics, they can be effectively used as adsorbent of pollutants (such as metal ions). The initial objective of this study was to characterize the clay Brasgel through the techniques of X-Ray Diffraction (XRD), X-Ray Spectrometry by Energy Dispersive (EDX) and nitrogen adsorption (BET method), seeking its use in removing lead (Pb 2+ ) from synthetic effluents. System was used in finite bath to assess the potential removal of lead (Pb 2+ ), following a 2 2 factorial experimental design with three center point experiments, taking as input variables: pH and initial concentrations of lead (Pb 2+ ). The clay has Brasgel clay in its composition that characterize it as a smectite clay. By having a large surface area, this clay showed great potential on the adsorption of metal ions. (author)

  9. Synthetic vision display evaluation studies

    Science.gov (United States)

    Regal, David M.; Whittington, David H.

    1994-01-01

    The goal of this research was to help us understand the display requirements for a synthetic vision system for the High Speed Civil Transport (HSCT). Four experiments were conducted to examine the effects of different levels of perceptual cue complexity in displays used by pilots in a flare and landing task. Increased levels of texture mapping of terrain and runway produced mixed results, including harder but shorter landings and a lower flare initiation altitude. Under higher workload conditions, increased texture resulted in an improvement in performance. An increase in familiar size cues did not result in improved performance. Only a small difference was found between displays using two patterns of high resolution texture mapping. The effects of increased perceptual cue complexity on performance was not as strong as would be predicted from the pilot's subjective reports or from related literature. A description of the role of a synthetic vision system in the High Speed Civil Transport is provide along with a literature review covering applied research related to perceptual cue usage in aircraft displays.

  10. Mammalian synthetic biology for studying the cell.

    Science.gov (United States)

    Mathur, Melina; Xiang, Joy S; Smolke, Christina D

    2017-01-02

    Synthetic biology is advancing the design of genetic devices that enable the study of cellular and molecular biology in mammalian cells. These genetic devices use diverse regulatory mechanisms to both examine cellular processes and achieve precise and dynamic control of cellular phenotype. Synthetic biology tools provide novel functionality to complement the examination of natural cell systems, including engineered molecules with specific activities and model systems that mimic complex regulatory processes. Continued development of quantitative standards and computational tools will expand capacities to probe cellular mechanisms with genetic devices to achieve a more comprehensive understanding of the cell. In this study, we review synthetic biology tools that are being applied to effectively investigate diverse cellular processes, regulatory networks, and multicellular interactions. We also discuss current challenges and future developments in the field that may transform the types of investigation possible in cell biology. © 2017 Mathur et al.

  11. Removal of lead from the industrial and synthetic Cu-Pb-Fe alloy with argon barbotage

    Directory of Open Access Journals (Sweden)

    B. Oleksiak

    2012-01-01

    Full Text Available Results of research on removal of lead from synthetic and industrial Cu-Pb-Fe alloy with argon barbotage are presented. For examinations was taken a synthetic alloy and industrial alloy coming “Glogow II” Copperworks. As basic research equipment was used a pipe resistance furnace enabling heating of samples up to 1 473 K. Examinations were made in 2 test series. The 1 series was performed on the synthetic alloy, while in 2 series was used an industrial alloy. All series were conducted at 1 473 K and with gas fl ow 5,55•10-6, 6,94•10-6, 8,33•10-6, 9,72•10-6 m3•s-1.

  12. Lead Time Study,

    Science.gov (United States)

    1982-05-01

    1979, the number of titanium fabrications dropped from 16 to 4, primarily because of the sponge shortage and EPA and OSHA requirements. Non-military...East - Taiwan, Korea, Singapore, Malaysia and Hong Kong. In addition, a significant amount of ceramic parts, lead frames and high technology

  13. Optical studies of high quality synthetic diamond

    International Nuclear Information System (INIS)

    Sharp, S.J.

    1999-01-01

    This thesis is concerned with the study of fundamental and defect induced optical properties of synthetic diamond grown using high pressure, high temperature (HPHT) synthesis or chemical vapour deposition (CVD). The primary technique used for investigation is cathodoluminescence (including imaging and decay-time measurements) in addition to other forms of optical spectroscopy. This thesis is timely in that the crystallinity and purity of synthetic diamond has increased ten fold over the last few years. The diamond exciton emission, which is easily quenched by the presence of defects, is studied in high quality samples in detail. In addition the ability now exists to engineer the isotopic content of synthetic diamond to a high degree of accuracy. The experimental chapters are divided as follows: Chapter 2: High resolution, low temperature spectra reveal a splitting of the free-exciton phonon recombination emission peaks and the bound-exciton zero phonon line. Included are measurements of the variation in intensity and decay-time as a function of temperature. Chapter 3: The shift in energy of the phonon-assisted free-exciton phonon replicas with isotopic content has been measured. The shift is in agreement with the results of interatomic force model for phonon scattering due to isotope disorder. Chapter 4: A study of the shift in energy with isotopic content of the diamond of the GR1 band due to the neutral vacancy has allowed a verification of the theoretical predictions due to the Jahn Teller effect. Chapter 5: The spatial distribution of the free-exciton luminescence is studied in HPHT synthetic and CVD diamond. A variation in intensity with distance from the surface is interpreted as a significant non-radiative loss of excitons to the surface. Chapter 6: The decay-times of all known self-interstitial related centres have been measured in order to calculate the concentration of these centres present in electron irradiated diamond. (author)

  14. Removal of Lead from Wastewater Contaminated with Chemical Synthetic Dye by Aspergillus terreus

    Directory of Open Access Journals (Sweden)

    Lamyai Neeratanaphan

    2015-07-01

    Full Text Available Novel isolated microorganisms have been demonstrated to efficiently remove lead from wastewater contaminated with chemical synthetic dye. In this study, the physical and chemical parameters of wastewater samples (including Pb concentrations were analyzed before and after treatment with microorganisms. The highest Pb concentration detected in wastewater was 0.788 mg/l. Investigations of the Pb tolerance and removal capacities of microorganism strains isolated from the wastewater sediment resulted in the selection of three fungal isolates (F102, F203 and F302. Interestingly, isolate F203 had a Pb tolerance of up to 100 mg/l. Using DNA barcoding and morphological characteristics, fungal isolate F203 was identified as Aspergillus terreus. Wastewater characteristics before treatment included a grayish black color with pH, TDS, BOD, COD and Pb concentrations higher than the Thailand standard values. Wastewater qualities after treatment with A. terreus showed definite improvement; however, the values of certain parameters were still higher than the allowed values based on the Thailand standard. The only improvement that fell within the allowed standard was the Pb concentration. Next, A. terreus was used for Pb adsorption in wastewater with an initial Pb concentration of 0.788 mg/l at time points corresponding to 0, 24, 48, 72, 96, 120, 144 and 168 h of incubation. The results showed that A. terreus could adsorb and remove higher amounts of Pb from wastewater than the other fungal isolates. Time course adsorption analysis showed the remaining Pb concentrations as 0.788, 0.213, 0.162, 0.117, 0.100, 0.066, 0.042 and 0.032 mg/l, respectively; the percentage of Pb removal could be estimated as 0, 72.97, 79.44, 85.15, 87.31, 91.62, 94.67 and 95.94%, respectively. In conclusion, A. terreus possessed the ability to adsorb up to 96% of Pb from chemical synthetic dye within 168 h. Thus, A. terreus might be suitable for adaptation and use in Pb treatment.

  15. A study on lead equivalent

    International Nuclear Information System (INIS)

    Lin Guanxin

    1991-01-01

    A study on the rules in which the lead equivalent of lead glass changes with the energy of X rays or γ ray is described. The reason of this change is discussed and a new testing method of lead equivalent is suggested

  16. Dissolution studies of synthetic soddyite and uranophane

    International Nuclear Information System (INIS)

    Casas, I.; Perez, I.; Torrero, E.; Bruno, J.; Cera, E.; Duro, L.

    1997-09-01

    The dissolution of synthetically obtained soddyite and uranophane has been studied in solutions of low ionic strength. These are the likely final phases of the oxidative alternation pathway of uranium dioxide. The thermodynamic and kinetic dissolution properties of these phases have been determined at different bicarbonate concentrations. The solubilities determined in the experiments with soddyite correspond fairly well to the theoretical model calculated with a log K 0 s0 =3.9±0.7. For uranophane, the best fitting was obtained for a log K 0 s0 =11.7±0.6. The dissolution rate in the presence of bicarbonate gave for soddyite an average value of 6.8(±4.4) 10 -10 mol m -2 s -1 . For uranophane, under the same experimental conditions, the following dissolution rate equation has been derived: r 0 (mol m -2 s -1 )=10 -9±2. [HCO 3 - ] 0.69±0.09 2

  17. Synthetic

    Directory of Open Access Journals (Sweden)

    Anna Maria Manferdini

    2010-06-01

    Full Text Available Traditionally materials have been associated with a series of physical properties that can be used as inputs to production and manufacturing. Recently we witnessed an interest in materials considered not only as ‘true matter’, but also as new breeds where geometry, texture, tooling and finish are able to provoke new sensations when they are applied to a substance. These artificial materials can be described as synthetic because they are the outcome of various qualities that are not necessarily true to the original matter, but they are the combination of two or more parts, whether by design or by natural processes. The aim of this paper is to investigate the potential of architectural surfaces to produce effects through the invention of new breeds of artificial matter, using micro-scale details derived from Nature as an inspiration.

  18. Synthetic Medicinal Chemistry in Chagas' Disease: Compounds at The Final Stage of "Hit-To-Lead" Phase.

    Science.gov (United States)

    Cerecetto, Hugo; González, Mercedes

    2010-03-25

    Chagas' disease, or American trypanosomosiasis, has been the most relevant illness produced by protozoa in Latin America. Synthetic medicinal chemistry efforts have provided an extensive number of chemodiverse hits at the "active-to-hit" stage. However, only a more limited number of these have been studied in vivo in models of Chagas' disease. Herein, we survey some of the cantidates able to surpass the "hit-to-lead" stage discussing their limitations or merit to enter in clinical trials in the short term.

  19. Smoking synthetic marijuana leads to self-mutilation requiring bilateral amputations.

    Science.gov (United States)

    Meijer, Karim A; Russo, Russell R; Adhvaryu, Dhaval V

    2014-04-01

    Synthetic cannabinoids have become a worldwide epidemic because they provide a sometimes legal, easily accessible, and presumably safe alternative to marijuana. Recently published reports have linked acute psychosis, myocardial infarctions, convulsions, self-harm, and even terrorist organizations to these designer substances. This case report outlines the first reported case of Black Diamond, a synthetic cannabis, leading to a self-inflicted burn to the bilateral upper extremities requiring a transradial amputation of the right arm and a toe transfer procedure of the left hand after loss of all digits. The patient presented to the emergency department with self-inflicted fourth-degree burns to the bilateral hands and forearms with second-degree burns of the face, for a total body surface area of 14.5%. The patient was found by firefighters with his hands aflame on his kitchen stove. With no previous medical or psychiatric history and collateral information to confirm the patient's mental status prior to use of Black Diamond, the patient's acute psychotic episode was attributed to Black Diamond. After multiple procedures and a lengthy recovery, the patient completed his post-graduate education and entered the professional world. As orthopedic surgeons, we should be involved in educating the public on the harm of these designer drugs, including self-mutilation. The popularity of synthetic drugs in the United States will continue to present a major challenge to all health care providers. Orthopedists are on the front lines of this epidemic because these drugs push patients into risky, traumatic behavior. Copyright 2014, SLACK Incorporated.

  20. Visualization study of hybrid synthetic jets

    Czech Academy of Sciences Publication Activity Database

    Broučková, Zuzana; Trávníček, Zdeněk

    2015-01-01

    Roč. 18, č. 4 (2015), s. 581-593 ISSN 1343-8875 R&D Projects: GA ČR GA14-08888S Institutional support: RVO:61388998 Keywords : synthetic jet * efficiency * flow visualization Subject RIV: JU - Aeronautics, Aerodynamics, Aircrafts Impact factor: 0.720, year: 2015 http://link.springer.com/article/10.1007/s12650-014-0256-8

  1. Ultrastructural studies of synthetic apatite crystals.

    Science.gov (United States)

    Arends, J; Jongebloed, W L

    1979-03-01

    In this paper a survey is given of some ultrastructural properties of synthetic hydroxyapatite. The preparation method by which single crystals with a length in the range of 0.1-3.0mm and a defined purity and stoïchiometry can be produced is given. Two groups of materials are considered in detail: carbonate-rich (greater than 0.1% CO3) and low-carbonate hydroxyapatites. The experiments on carbonate-rich material, being the most interesting from a biological point of view, show that acids attack at an active site in the hexagonal basal-plane of the crystals. Later on the crystals dissolve in the center of the crystal parallel to the c-axis forming tube-like structures. The active site can be protected from dissolution if the crystals are pretreated by EHDP or MFP. A comparison with lattice defect theory shows that most likely dislocations of the "hollow-core" type are responsible for the preferential dissolution.

  2. Numerical study of circular synthetic jets at low Reynolds numbers

    International Nuclear Information System (INIS)

    Xia, Qingfeng; Lei, Shenghui; Ma, Jieyan; Zhong, Shan

    2014-01-01

    Highlights: • Parameter maps depicting different flow regimes of synthetic jets are produced. • Boundaries separating these regimes are defined using quantitative criteria. • The Reynolds number is most appropriate for classifying different flow regimes. • A use of high suction cycle factors enhances the effectiveness of synthetic jets. - Abstract: In this paper, the flow patterns of circular synthetic jets issuing into a quiescent flow at low Reynolds numbers are studied numerically. The results confirm the presence of the three jet flow regimes, i.e. no jet formation, jet flow without rollup and jet flow with rollup reported in the literature. The boundaries of the different jet flow regimes are determined by tracking the structures produced by the synthetic jets in the near field of the jet orifice over several actuation cycles and examining the cycle-averaged streamwise velocity profiles along the jet central axis. When the Stokes number is above a certain threshold value appropriate for the corresponding flow regime, a good correlation between the flow patterns and the jet Reynolds number defined using the jet orifice diameter, Re Do , is also found. Furthermore, the flow structures of synthetic jets with different suction duty cycle factors are compared. The use of a high suction duty cycle factor strengthens the synthetic jet resulting in a greater penetration depth into the surrounding fluid. Overall, the finding from this study enables the flow regimes, in which a synthetic jet actuator with a circular orifice operates, to be determined. It also provides a way of designing more effective synthetic jet actuators for enhancing mass and momentum transfer at very low Reynolds numbers

  3. Study of synthetic ferrimagnet-synthetic antiferromagnet structures for magnetic sensor application

    Science.gov (United States)

    Guedes, A.; Mendes, M. J.; Freitas, P. P.; Martins, J. L.

    2006-04-01

    There has been a growing interest in using both synthetic ferrimagnet (SF) free and synthetic antiferromagnet (SAF) pinned layers for head and memory applications. In particular, for linear sensor applications, these structures lower the magnetostatic fields present at the free layer through the reduction of its effective thickness (teffSF). This allows higher sensitivity but at the expense of an increased offset field H0(Néel coupling field Hf+interlayer demagnetizing field HdSAF). In this work, results on a series of patterned 3×1 and 6×2 μm2 top-pinned SF-SAF spin valves are analyzed and compared with a three-dimensional micromagnetic simulation in order to clarify the role of the different ferromagnetic layers in the overall offset field and sensitivity. H0 varies as 1/teffSF[teffSF=(Mata-Mbtb)/MeffSF]. The magnetostatic field acting on the SF coming from the SAF (HdSAF) can act as a biasing field, partially counterbalancing the Néel coupling field (Hf) leading to a reduction of H0. In this work the offset field was reduced from an initial value of 25 Oe in a quasicompensated SAF to a value of -6 Oe, by unbalancing the SAF and consequently increasing its effective moment (teffSF=15 A˚).

  4. Mortality study of lead workers

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, W C; Gaffey, W R

    1975-01-01

    The mortality of 7,032 men employed for one or more years in lead production facilities or battery plants was followed over a 23-year period, 1947-70. Lead absorption in many of these men was greatly in excess of currently accepted standards based upon urinary and blood lead concentrations available for a portion of the group. There were 1,356 deaths reported. The standardized mortality ratio (SMR) for all causes was 107 for smelter workers and 99 for battery plant workers. Death from neoplasms were in slight excess in smelters, but not significantly increased in battery plants. There were no excess deaths from kidney tumors. The SMR for cardiovascular-renal disease was 96 for smelter workers and 101 for battery plant workers. There was definitely no excess in deaths from either stroke or hypertensive heart disease; however, deaths classified as other hypertensive disease and unspecified nephritis or renal sclerosis were higher than expected. The life expectancy of lead workers was calculated to be approximately the same as that of all U.S. males.

  5. Comparative study of the electronic structure of natural and synthetic ...

    Indian Academy of Sciences (India)

    ... have studied the Cr–K-edge XANES and EXAFS in natural Indian rubies from two sources and a synthetic ruby at ESRF. Weight % of various constituents in them is determined using EDAX measurements. Taking the results from the three techniques together we are able to demonstrate their feasibility in quantitative study ...

  6. Stability notions in synthetic graph generation: a preliminary study

    NARCIS (Netherlands)

    van Leeuwen, W.; Fletcher, G.H.L.; Yakovets, N.; Bonifati, A.; Markl, Volker; Orlando, Salvatore; Mitschang, Bernhard

    2017-01-01

    With the rise in adoption of massive graph data, it be- comes increasingly important to design graph processing algorithms which have predictable behavior as the graph scales. This work presents an initial study of stability in the context of a schema-driven synthetic graph generation. Specifically,

  7. A Preliminary Trypanocidal Study of Natural and Synthetic ...

    African Journals Online (AJOL)

    Eighty healthy Wistar albino rats were used to investigate the trypanocidal effect of natural and synthetic supplements of zinc and magnesium in combination with diminazene aceturate in Trypanosoma congolense-inoculated rats. The rats were randomly divided into eight groups in study '1' (involving the natural ...

  8. Comparative study of the electronic structure of natural and synthetic ...

    Indian Academy of Sciences (India)

    Unknown

    We have studied the Cr–K-edge XANES and EXAFS in natural Indian rubies from two sources and a synthetic ... mineral in a wide variety of quality spread all over the world e.g. Burma ... using Si diode pairs oriented toward the sample. The.

  9. Norbadione A: synthetic approach and cesium complexation studies

    International Nuclear Information System (INIS)

    Desage - El Murr, M.

    2003-10-01

    This work was dedicated to the study of the synthesis and complexation studies of norbadione A: a pigment originating from a mushroom. A synthetic approach, based on a double Suzuki-Miyaura coupling, was developed. This strategy was applied with high yields to the synthesis of various norbadione A analogues, as well as to the synthesis of simple pulvinic acids. Access to functionalized precursors of the molecule was also studied and the final coupling remains to be done. Besides, a speciation study based on electro-spray ionization mass spectrometry was conducted with norbadione A and one of the analogues. This study allowed the assessment of the cesium complexation abilities of each molecule. Structural data was also obtained and complexation constants were calculated. Finally, norbadione A and various synthetic products have been tested via high-throughput screening methods and strong antioxidant properties were observed. Other biological results are also reported. (author)

  10. Synthesis and study of the synthetic hydroxyapatite doped with aluminum

    Science.gov (United States)

    Goldberg, M.; Smirnov, V.; Antonova, O.; Konovalov, A.; Fomina, A.; Komlev, V. S.; Barinov, S.; Rodionov, A.; Gafurov, M.; Orlinskii, S.

    2018-05-01

    Powders of synthetic hydroxyapatite doped with aluminium (Al) ions in concentrations 0 and 20 mol. % were synthesized by the precipitation method from the nitrate solutions and investigated by atomic emission spectrometry with inductively coupled plasma (AES-ICP), X-ray diffraction (XRD), scanning electron microscopy (SEM), gas absorption and conventional electron paramagnetic resonance (EPR). It is shown that for the chosen synthesis route an introduction of Al provokes formation of highly anisotropic phase, leads to the decrease in the crystallinity while no significant changes in the EPR spectra of the radiation-induced defects is observed. The results could be used for understanding the structural transformations with Al doping of the mineralized materials for geological and biomedical applications.

  11. Synthetic strategies for plant signalling studies: molecular toolbox and orthogonal platforms

    KAUST Repository

    Braguy, Justine

    2016-05-26

    Plants deploy a wide array of signalling networks integrating environmental cues with growth, defence and developmental responses. The high level of complexity, redundancy and connection between several pathways hampers a comprehensive understanding of involved functional and regulatory mechanisms. The implementation of synthetic biology approaches is revolutionizing experimental biology in prokaryotes, yeasts and animal systems and can likewise contribute to a new era in plant biology. This review gives an overview on synthetic biology approaches for the development and implementation of synthetic molecular tools and techniques to interrogate, understand and control signalling events in plants, ranging from strategies for the targeted manipulation of plant genomes up to the spatiotemporally resolved control of gene expression using optogenetic approaches. We also describe strategies based on the partial reconstruction of signalling pathways in orthogonal platforms, like yeast, animal and in vitro systems. This allows a targeted analysis of individual signalling hubs devoid of inter-connectivity with endogenous interacting components. Implementation of the interdisciplinary synthetic biology tools and strategies is not exempt of challenges and hardships but simultaneously most rewarding in terms of the advances in basic and applied research. As witnessed in other areas, these original theoretical-experimental avenues will lead to a breakthrough in the ability to study and comprehend plant signalling networks. This article is protected by copyright. All rights reserved.

  12. Parametric Study of Synthetic-Jet-Based Flow Control on a Vertical Tail Model

    Science.gov (United States)

    Monastero, Marianne; Lindstrom, Annika; Beyar, Michael; Amitay, Michael

    2015-11-01

    Separation control over the rudder of the vertical tail of a commercial airplane using synthetic-jet-based flow control can lead to a reduction in tail size, with an associated decrease in drag and increase in fuel savings. A parametric, experimental study was undertaken using an array of finite span synthetic jets to investigate the sensitivity of the enhanced vertical tail side force to jet parameters, such as jet spanwise spacing and jet momentum coefficient. A generic wind tunnel model was designed and fabricated to fundamentally study the effects of the jet parameters at varying rudder deflection and model sideslip angles. Wind tunnel results obtained from pressure measurements and tuft flow visualization in the Rensselaer Polytechnic Subsonic Wind Tunnel show a decrease in separation severity and increase in model performance in comparison to the baseline, non-actuated case. The sensitivity to various parameters will be presented.

  13. In vivo x-ray fluorescence of bone lead in the study of human lead metabolism: Serum lead, whole blood lead, bone lead, and cumulative exposure

    International Nuclear Information System (INIS)

    Cake, K.M.; Chettle, D.R.; Webber, C.E.; Gordon, C.L.

    1995-01-01

    Traditionally, clinical studies of lead's effect on health have relied on blood lead levels to indicate lead exposure. However, this is unsatisfactory because blood lead levels have a half-life of approximately 5 weeks, and thus reflect recent exposure. Over 90% of the lead body burden is in bone, and it is thought to have a long residence time, thus implying that measurements of bone lead reflect cumulative exposure. So, measurements of bone lead are useful in understanding the long-term health effects of lead. Ahlgren reported the first noninvasive measurements of bone lead in humans, where γ-rays from 57 Co were used to excite the K series x-rays of lead. The lead detection system at McMaster University uses a 109 Cd source which is positioned at the center of the detector face (HPGe) and a near backscatter (∼160 degrees) geometry. This arrangement allows great flexibility, since one can sample lead in a range of different bone sites due to a robust normalization technique which eliminates the need to correct for bone geometry, thickness of overlying tissue, and other related factors. The effective radiation dose to an adult during an x-ray fluorescence bone lead measurement is extremely low, being 35 nSv. This paper addresses the issue of how bone, whole blood, and serum lead concentrations can be related in order to understand a person's lead exposure history

  14. Vectoring of parallel synthetic jets: A parametric study

    Science.gov (United States)

    Berk, Tim; Gomit, Guillaume; Ganapathisubramani, Bharathram

    2016-11-01

    The vectoring of a pair of parallel synthetic jets can be described using five dimensionless parameters: the aspect ratio of the slots, the Strouhal number, the Reynolds number, the phase difference between the jets and the spacing between the slots. In the present study, the influence of the latter four on the vectoring behaviour of the jets is examined experimentally using particle image velocimetry. Time-averaged velocity maps are used to study the variations in vectoring behaviour for a parametric sweep of each of the four parameters independently. A topological map is constructed for the full four-dimensional parameter space. The vectoring behaviour is described both qualitatively and quantitatively. A vectoring mechanism is proposed, based on measured vortex positions. We acknowledge the financial support from the European Research Council (ERC Grant Agreement No. 277472).

  15. First studies of lead pollution in Guanabara

    International Nuclear Information System (INIS)

    Silveira Branquinho, C.L. da.

    1973-01-01

    The main sources of direct lead intake are studied, and metal concentrations in several medium are examined. Lead was extracted by dithizone in C Cl 4 , being determined by optical spectrophotometry. 2 1 2 Pb was used as a radioactive tracer in low concentration measurements of the metal, and analysis of its 239 KeV peak was done by a Ge-Li detector. In blood samples, the metal was complexed and extracted with APDC in MIBK, being measured by flame less atomic absorption spectrophotometry. Air samples were also collected for periods of 24 hours and 90 minutes. Representative street dust samples were examined, showing a strict correlation with lead in air. It was also estimated the amount of lead in some human blood samples. (author)

  16. The relevance of polymeric synthetic membranes in topical formulation assessment and drug diffusion study.

    Science.gov (United States)

    Ng, Shiow-Fern; Rouse, Jennifer J; Sanderson, Francis D; Eccleston, Gillian M

    2012-03-01

    Synthetic membranes are composed of thin sheets of polymeric macromolecules that can control the passage of components through them. Generally, synthetic membranes used in drug diffusion studies have one of two functions: skin simulation or quality control. Synthetic membranes for skin simulation, such as the silicone-based membranes polydimethylsiloxane and Carbosil, are generally hydrophobic and rate limiting, imitating the stratum corneum. In contrast, synthetic membranes for quality control, such as cellulose esters and polysulfone, are required to act as a support rather than a barrier. These synthetic membranes also often contain pores; hence, they are called porous membranes. The significance of Franz diffusion studies and synthetic membranes in quality control studies involves an understanding of the fundamentals of synthetic membranes. This article provides a general overview of synthetic membranes, including a brief background of the history and the common applications of synthetic membranes. This review then explores the types of synthetic membranes, the transport mechanisms across them, and their relevance in choosing a synthetic membrane in Franz diffusion cell studies for formulation assessment purposes.

  17. Autonomy and Fear of Synthetic Biology: How Can Patients' Autonomy Be Enhanced in the Field of Synthetic Biology? A Qualitative Study with Stable Patients.

    Science.gov (United States)

    Rakic, Milenko; Wienand, Isabelle; Shaw, David; Nast, Rebecca; Elger, Bernice S

    2017-04-01

    We analyzed stable patients' views regarding synthetic biology in general, the medical application of synthetic biology, and their potential participation in trials of synthetic biology in particular. The aim of the study was to find out whether patients' views and preferences change after receiving more detailed information about synthetic biology and its clinical applications. The qualitative study was carried out with a purposive sample of 36 stable patients, who suffered from diabetes or gout. Interviews were transcribed verbatim, translated and fully anonymized. Thematic analysis was applied in order to examine stable patients' attitudes towards synthetic biology, its medical application, and their participation in trials. When patients were asked about synthetic biology in general, most of them were anxious that something uncontrollable could be created. After a concrete example of possible future treatment options, patients started to see synthetic biology in a more positive way. Our study constitutes an important first empirical insight into stable patients' views on synthetic biology and into the kind of fears triggered by the term "synthetic biology." Our results show that clear and concrete information can change patients' initial negative feelings towards synthetic biology. Information should thus be transmitted with great accuracy and transparency in order to reduce irrational fears of patients and to minimize the risk that researchers present facts too positively for the purposes of persuading patients to participate in clinical trials. Potential participants need to be adequately informed in order to be able to autonomously decide whether to participate in human subject research involving synthetic biology.

  18. Elastic FWI for VTI media: A synthetic parameterization study

    KAUST Repository

    Kamath, Nishant; Tsvankin, Ilya; Diaz, Esteban

    2016-01-01

    A major challenge for multiparameter full-waveform inversion (FWI) is the inherent trade-offs (or cross-talk) between model parameters. Here, we perform FWI of multicomponent data generated for a synthetic VTI (transversely isotropic with a vertical

  19. Moessbauer Study of Discoloration of Synthetic Resin Covered Electric Switches

    International Nuclear Information System (INIS)

    Kuzmann, E.; Muzsay, I.; Homonnay, Z.; Vertes, A.

    2002-01-01

    57 Fe Moessbauer spectroscopy and X-ray diffractometry were used to investigate brown discoloration and sediments formed on the surface of synthetic resin product covered electronic switches. The Moessbauer measurement revealed that alloyed steels and iron-containing corrosion products are associated with the discolored layers. Iron, and iron corrosion products were shown by both MS and XRD in the sediments formed eventually during the finishing of the synthetic resin products after machining and washing with water solution.

  20. Synthetic study of reactor irradiation for medical use

    International Nuclear Information System (INIS)

    An, Shigehiro; Furuhashi, Akira; Kanda, Keiji; Sumita, Kenji; Kakihana, Hidetake.

    1978-01-01

    This report is described on the results of the study on the reactor irradiation for medical use shared by the Nuclear Engineering Research Laboratory, Faculty of Engineering, University of Tokyo, and other seventeen facilities. Boron neutron-capturing therapy developed in Japan is extremely significant treating method for tumors by destroying tumor cells of encephaloma, etc. selectively. This is the synthetic study for promoting the above therapeutic method. Two existing reactors were reconstructed into the thermal neutron reactors for boron neutron-capturing therapy. The various preparatory and physical researches were made with the reconstruction, and the therapy was tried on eleven cases. Further experiments were made on the following points: (1) To promote treatment on encephaloma by boron neutron-capturing therapy. (2) To develop its application to malignant tumors other than encephaloma. (3) Animal irradiation experiments. (4) The basic experiments on the cellular level. (5) The study of remote controlled anesthesia. (6) To control irradiated dose. (7) To improve boron compounds. (8) To condense radioisotopes. (Kobatake, H.)

  1. Spectroscopy Study of Synthetic Forsterite Obtained from Zeolite Precursors

    Directory of Open Access Journals (Sweden)

    Subotić, B.

    2008-02-01

    Full Text Available Important ceramics materials are prepared from aluminosilicate based precursors using novel methods, offering at the same time a better control over many important properties. Forsterite, due to its good refractoriness with melting point at 2163 K, excellent electrical insulation properties even at high temperatures, low dielectric permittivity, thermal expansion and chemical stability, is a material of interest to engineers and designers especially as an active medium for tuneable laser and is also a material of interest to SOFC (Solid oxide fuel cells manufacturers. The aim of this study is to investigate the synthesis of crystalline forsterite using different zeolite precursors previously activated by ball milling. Synthetic forsterite was synthesized from different zeolite precursors and MgO combining highenergy ball milling and thermal treatment of the mixture under determined conditions of time and temperature for each operation. In this research are studied the solid-state phase transformations taking place at temperatures below 1273 K. The obtained products were characterized using different spectroscopy techniques in comparison with surface analysis method and X-ray diffraction.

  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. A study of porosity of synthetic polymer nanoparticles using PALS

    Energy Technology Data Exchange (ETDEWEB)

    Pham, B; Smith, S V [Centre for Antimatter-Matter Studies, Australian Nuclear Science and Technology Organisation (ANSTO) NSW 2232 (Australia); Guagliardo, P; Williams, J; Samarin, S, E-mail: binh.pham@ansto.gov.au, E-mail: svs@ansto.gov.au [Centre for Antimatter-Matter Studies, School of Physics, University of Western Australia, WA 6009 (Australia)

    2011-01-01

    Positron annihilation lifetime spectroscopy (PALS) has been used to study the free volume in dry synthetic polymer nanoparticles of various sizes. A series of poly(styrene/divinyl benzene) particles with diameters in the range of 100 to 500 nm were synthesized and then carefully chemically treated using the sulfonation process, to increase their porosity. The particles were characterised by Scanning Electron Microscopy (SEM), light scattering and PALS. Light scattering gave larger size for the treated particles, reflecting the hydration effect and therefore the increase in porosity. PALS spectra of untreated and treated particles gave four and three life-time components, respectively. Analysis by PAScual version 1.3.0 program indicated there was a reduction in the intensity and the type of the micropores in the treated particles. The data suggest PALS is a sensitive tool for detecting changes in microporosity in particles. The conflicting results obtained for light scattering compared to PALS for chemically treated particles is difficult to resolve and suggests sample preparation of polymeric materials for PALS is the critical factor.

  4. Spectroscopic study of synthetic hydrothermal Fe3+-bearing beryl

    Science.gov (United States)

    Taran, Michail N.; Dyar, M. Darby; Khomenko, Vladimir M.

    2018-05-01

    A synthetic hydrothermal beryl Fe-4-51, investigated previously by Taran and Rossman (Am Miner 86:973-980, 2001), was additionally studied by microprobe, Mössbauer, optical absorption, Raman and IR spectroscopy. For comparison, polarized spectra of natural blue aquamarine and Cr3+, Fe3+-bearing alexandrite, both from Brazil, are also presented. Fe-4-51 is a nearly pure Fe3+-bearing beryl, with a homogeneous composition as shown by electron microprobe. Averaging over 22 points gives a formula of Be3.07(Al1.94,{Fe}_{{{0.07}}}^{{{3}+}})Σ=2.01Si5.95O18, with Fe3+ replacing Al3+ in the octahedral site of the structure. The Mössbauer spectrum is dominated by a broad disordered pattern with beryl-suitable parameters; for Fe2+, IS = 1.21 mm/s, QS = 2.71 mm/s, area ≈ 5% and for Fe3+, IS = 0.34 mm/s, QS = 0.71 mm/s, and area ≈ 67%—are distinguished overlying a broad disordered continuum. The optical absorption spectrum is typical of octahedral Fe3+. From it, the crystal field strength Dq is derived as 1520 cm-1 and the values of Racah parameters of interelectronic repulsion B and C are found to be 665 and 3415 cm-1, respectively. This rather low B value, compared with that of a free Fe3+ ion, 814 cm-1, suggests a comparatively high degree of covalency in the octahedral Fe3+-O bond. Infrared spectra show the presence of channel H2O of both I and II structural type in comparable quantities, about 0.5 and 1 mass%, respectively. Raman data show the expected five bands in the energy range from 300 to 1200 cm-1.

  5. Synthetic food colourings and 'hyperactivity': a double-blind crossover study.

    Science.gov (United States)

    Rowe, K S

    1988-04-01

    Of 220 children referred for suspected 'hyperactivity', 55 were subjected to a 6 week trial of the Feingold diet. Forty (72.7%) demonstrated improved behaviour and 26 (47.3%) remained improved following liberalization of the diet over a period of 3-6 months. The parents of 14 children claimed that a particular cluster of behaviours was associated with the ingestion of foods containing synthetic colourings. A double-blind crossover study, employing a single-subject repeated measures design was conducted, using eight of these children. Subjects were maintained on a diet free from synthetic additives and were challenged daily for 18 weeks with either placebo (during lead-in and washout periods) or 50 mg of either tartrazine or carmoisine, each for 2 separate weeks. Two significant reactors were identified whose behavioural pattern featured extreme irritability, restlessness and sleep disturbance. One of the reactors did not have inattention as a feature. The findings raise the issue of whether the strict criteria for inclusion in studies concerned with 'hyperactivity' based on 'attention deficit disorder' may miss children who indicate behavioural changes associated with the ingestion of food colourings. Moreover, for further studies, the need to construct a behavioural rating instrument specifically validated for dye challenge is suggested.

  6. Radioactive lead studies in the human

    International Nuclear Information System (INIS)

    Blake, K.C.H.

    1980-08-01

    The differing susceptibility of individuals to the toxic effects of chronic lead exposure has never been fully understood. As the major intake of lead in the human is from food and beverages, any variation between individuals of the quantity of lead absorbed from the gut, and of the distribution and excretion of this lead, may account for the differences in individual susceptibility. The food and beverages themselves may have an influence, and to investigate their effects on absorption, distribution and excretion of lead, experiments were performed on normal subjects using a short lived radionuclide of lead, 203 Pb, and instruments generally available in Nuclear Medicine. Lead absorption between different individuals showed a wide variation when 203 Pb was taken as a single dose between meals. Minerals were found to be mainly responsible for affecting absorption when one subject ingested 203 Pb in control meals from which one dietary constituent at a time was omitted. Calcium and phosphorous were found to reduce the absorption of 203 Pb to approximately the same level as that produced by the total minerals. Calcium reduced absorption more than phosphorous when these minerals were ingested separately with 203 Pb. It was concluded that the calcium and phosphorous in the diet could influence susceptibility to lead toxicity through changes in the absorption of food and water lead and in the distribution of lead in the body. The results suggest that the prophylactic effect of calcium on lead absorption should be recognised and applied in this time of increased environmental levels of lead

  7. Morphology and thermal degradation study of poly(lactic acid)/synthetic mica composites

    International Nuclear Information System (INIS)

    Souza, D.H.S.; Dias, M.L.

    2010-01-01

    Poly(lactic acid) (PLA)/synthetic mica composites has been little studied in the literature. In this work, an organophilic synthetic mica was used to prepare PLA nanocomposites. The composites were obtained at an internal mixer containing 3, 5, 7 and 10 wt% of mica. The materials were analyzed by x-ray diffraction, thermogravimetric analysis and gel permeation chromatography. (author)

  8. X-ray studies of synthetic radiation-counting diamonds

    Energy Technology Data Exchange (ETDEWEB)

    Yacoot, Andrew; Moore, Moreton (Royal Holloway and Bedford New Coll., Egham (UK). Dept. of Physics); Makepeace, Anthony (Bristol Univ. (UK). Dept. of Physiology)

    1990-10-01

    Synthetic diamonds with a nitrogen content less than 100 ppm may be used as radiation dosemeters in a conduction counting mode, and are especially useful in medical applications. Crystal imperfections, revealed by x-ray diffraction topography, were found to affect counting performance. The best quality diamond gave the highest photocurrent (500 nA at 50 V mm{sup -1} and 2.75 Gy min{sup -1}). Diamonds containing dislocations had lower photocurrents but had the advantage of shorter settling times (seconds rather than minutes). Placing contacts on two opposite cube {l brace}100{r brace} faces gave a higher photocurrent than on a pair of octahedral {l brace}111{r brace} faces. Higher photocurrents were also achieved when the majority of dislocations were perpendicular rather than parallel, to the electric field. Some recommendations for selecting synthetic diamonds for dosemeters are given. (author).

  9. Mathematical modeling of synthetic unit hydrograph case study: Citarum watershed

    Science.gov (United States)

    Islahuddin, Muhammad; Sukrainingtyas, Adiska L. A.; Kusuma, M. Syahril B.; Soewono, Edy

    2015-09-01

    Deriving unit hydrograph is very important in analyzing watershed's hydrologic response of a rainfall event. In most cases, hourly measures of stream flow data needed in deriving unit hydrograph are not always available. Hence, one needs to develop methods for deriving unit hydrograph for ungagged watershed. Methods that have evolved are based on theoretical or empirical formulas relating hydrograph peak discharge and timing to watershed characteristics. These are usually referred to Synthetic Unit Hydrograph. In this paper, a gamma probability density function and its variant are used as mathematical approximations of a unit hydrograph for Citarum Watershed. The model is adjusted with real field condition by translation and scaling. Optimal parameters are determined by using Particle Swarm Optimization method with weighted objective function. With these models, a synthetic unit hydrograph can be developed and hydrologic parameters can be well predicted.

  10. Oxide nanomaterials: synthetic developments, mechanistic studies, and technological innovations.

    Science.gov (United States)

    Patzke, Greta R; Zhou, Ying; Kontic, Roman; Conrad, Franziska

    2011-01-24

    Oxide nanomaterials are indispensable for nanotechnological innovations, because they combine an infinite variety of structural motifs and properties with manifold morphological features. Given that new oxide materials are almost reported on a daily basis, considerable synthetic and technological work remains to be done to fully exploit this ever increasing family of compounds for innovative nano-applications. This calls for reliable and scalable preparative approaches to oxide nanomaterials and their development remains a challenge for many complex nanostructured oxides. Oxide nanomaterials with special physicochemical features and unusual morphologies are still difficult to access by classic synthetic pathways. The limitless options for creating nano-oxide building blocks open up new technological perspectives with the potential to revolutionize areas ranging from data processing to biocatalysis. Oxide nanotechnology of the 21st century thus needs a strong interplay of preparative creativity, analytical skills, and new ideas for synergistic implementations. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Microhardness studies of nanocrystalline lead molybdate

    International Nuclear Information System (INIS)

    Anandakumar, V.M.; Abdul Khadar, M.

    2009-01-01

    Nanocrystalline lead molybdate (PbMoO 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 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 ∼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. 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

  13. Study of Wide Swath Synthetic Aperture Ladar Imaging Techology

    Directory of Open Access Journals (Sweden)

    Zhang Keshu

    2017-02-01

    Full Text Available Combining synthetic-aperture imaging and coherent-light detection technology, the weak signal identification capacity of Synthetic Aperture Ladar (SAL reaches the photo level, and the image resolution exceeds the diffraction limit of the telescope to obtain high-resolution images irrespective to ranges. This paper introduces SAL, including the development path, technology characteristics, and the restriction of imaging swath. On the basis of this, we propose to integrate the SAL technology for extending its swath. By analyzing the scanning-operation mode and the signal model, the paper explicitly proposes that the former mode will be the developmental trend of the SAL technology. This paper also introduces the flight demonstrations of the SAL and the imaging results of remote targets, showing the potential of the SAL in long-range, high-resolution, and scanning-imaging applications. The technology and the theory of the scanning mode of SAL compensates for the defects related to the swath and operation efficiency of the current SAL. It provides scientific foundation for the SAL system applied in wide swath, high resolution earth observation, and the ISAL system applied in space-targets imaging.

  14. Synthetic Cannabinoids

    Directory of Open Access Journals (Sweden)

    Aslihan Okan Ibiloglu

    2017-09-01

    Full Text Available Synthetic cannabinoids which is a subgroup of cannabinoids are commonly used for recreational drug use throughout the whole world. Although both marijuana and synthetic cannabinoids stimulate the same receptors, cannabinoid receptor 1 (CB1 and cannabinoid receptor 2 (CB2, studies have shown that synthetic cannabinoids are much more potent than marijuana. The longer use of synthetic cannabinoids can cause severe physical and psychological symptoms that might even result in death, similar to many known illicit drugs. Main treatment options mostly involve symptom management and supportive care. The aim of this article is to discuss clinical and pharmacological properties of the increasingly used synthetic cannabinoids. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2017; 9(3.000: 317-328

  15. Shock induced melting of lead (experimental study)

    International Nuclear Information System (INIS)

    Mabire, Catherine; Hereil, Pierre L.

    2002-01-01

    To investigate melting on release of lead, two shock compression measurements have been carried out at 51 GPa. In the first one, a pyrometric measurement has been performed at the Pb/LiF interface. In the second one, the Pb/LiF interface velocity has been recorded using VISAR measurement technique. VISAR and radiance profile are in good agreement and seem to show melting on release of lead

  16. Experimental study of cooling performance of pneumatic synthetic jet with singular slot rectangular orifice

    Science.gov (United States)

    Yu, Roger Ho Zhen; Ismail, Mohd Azmi bin; Ramdan, Muhammad Iftishah; Mustaffa, Nur Musfirah binti

    2017-03-01

    Synthetic Jet generates turbulence flow in cooling the microelectronic devices. In this paper, the experiment investigation of the cooling performance of pneumatic synthetic jet with single slot rectangular orifices at low frequency motion is presented. The velocity profile at the end of the orifice was measured and used as characteristic performance of synthetic jet in the present study. Frequencies of synthetic jet and the compressed air pressure supplied to the pneumatic cylinder (1bar to 5bar) were the parameters of the flow measurement. The air velocity of the synthetic jet was measured by using anemometer air flow meter. The maximum air velocity was 0.5 m/s and it occurred at frequency motion of 8 Hz. The optimum compressed air supplied pressure of the synthetic jet study was 4 bar. The cooling performance of synthetic jet at several driven frequencies from 0 Hz to 8 Hz and heat dissipation between 2.5W and 9W were also investigate in the present study. The results showed that the Nusselt number increased and thermal resistance decreased with both frequency and Reynolds number. The lowest thermal resistance was 5.25°C/W and the highest Nusselt number was 13.39 at heat dissipation of 9W and driven frequency of 8Hz.

  17. Elastic FWI for VTI media: A synthetic parameterization study

    KAUST Repository

    Kamath, Nishant

    2016-09-06

    A major challenge for multiparameter full-waveform inversion (FWI) is the inherent trade-offs (or cross-talk) between model parameters. Here, we perform FWI of multicomponent data generated for a synthetic VTI (transversely isotropic with a vertical symmetry axis) model based on a geologic section of the Valhall field. A horizontal displacement source, which excites intensive shear waves in the conventional offset range, helps provide more accurate updates to the SV-wave vertical velocity. We test three model parameterizations, which exhibit different radiation patterns and, therefore, create different parameter trade-offs. The results show that the choice of parameterization for FWI depends on the availability of long-offset data, the quality of the initial model for the anisotropy coefficients, and the parameter that needs to be resolved with the highest accuracy.

  18. Fixation of tibial plateau fractures with synthetic bone graft versus natural bone graft: a comparison study.

    LENUS (Irish Health Repository)

    Ong, J C Y

    2012-06-01

    The goal of this study was to determine differences in fracture stability and functional outcome between synthetic bone graft and natural bone graft with internal fixation of tibia plateau metaphyseal defects.

  19. Synthetic cannabinoid JWH-018 and psychosis: an explorative study.

    Science.gov (United States)

    Every-Palmer, Susanna

    2011-09-01

    Aroma, Spice, K2 and Dream are examples of a class of new and increasingly popular recreational drugs. Ostensibly branded "herbal incense", they have been intentionally adulterated with synthetic cannabinoids such as JWH-018 in order to confer on them cannabimimetic psychoactive properties while circumventing drug legislation. JWH-018 is a potent cannabinoid receptor agonist. Little is known about its pharmacology and toxicology in humans. This is the first research considering the effects of JWH-018 on a psychiatric population and exploring the relationship between JWH-018 and psychotic symptoms. This paper presents the results of semi-structured interviews regarding the use and effects of JWH-018 in 15 patients with serious mental illness in a New Zealand forensic and rehabilitative service. All 15 subjects were familiar with a locally available JWH-018 containing product called "Aroma" and 86% reported having used it. They credited the product's potent psychoactivity, legality, ready availability and non-detection in drug testing as reasons for its popularity, with most reporting it had replaced cannabis as their drug of choice. Most patients had assumed the product was "natural" and "safe". Anxiety and psychotic symptoms were common after use, with 69% of users experiencing or exhibiting symptoms consistent with psychotic relapse after smoking JWH-018. Although psychological side effects were common, no one reported becoming physically unwell after using JWH-018. Three subjects described developing some tolerance to the product, but no one reported withdrawal symptoms. It seems likely that JWH-018 can precipitate psychosis in vulnerable individuals. People with risk factors for psychosis should be counseled against using synthetic cannabinoids. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  20. Studies on the specificity of immunological reactions of synthetic and natural Thomsen-Friedenreich antigens

    International Nuclear Information System (INIS)

    Hoeppner, W.

    1982-01-01

    A number of derivatives of disaccharide β-D-Gal-(1,3)-D-GalNAc, the carbohydrate component of T-antigen, and four different synthetic antigens having this disaccharide structure have been investigated. The immunological reactions with native human antibodies and rabbit immune antibodies have been studied in the haemagglutination inhibition test and in RIA. The findings are relevant to the use of synthetic carbohydrate antigens as model substances for immunological studies. (orig./MG) [de

  1. Using XAFS, EDAX and AFM in comparative study of various natural and synthetic emeralds

    International Nuclear Information System (INIS)

    Parikh, P.; Saini, N.L.; Dalela, S.; Bhardwaj, D.M.; Fernandes, S.; Gupta, R.P.; Garg, K.B.

    2003-01-01

    We have performed XAFS, EDAX and AFM studies on some natural and synthetic emeralds. While the XAFS results yield information on changes in the valence of the Cr ion and the n-n distance the AFM is used to determine the areal atomic density on surface of the crystals. It is a pilot study to explore if the three techniques can offer a possible way of distinguishing between the natural and synthetic emeralds and the results are promising

  2. WETTABILITY STUDIES OF LEAD-FREE SOLDERS

    African Journals Online (AJOL)

    2012-03-01

    Mar 1, 2012 ... other industries due to its low cost and unique material properties like low melting point, avail- ability etc. However, the toxicity of lead during industrial production of components and the ... Companies in other countries. (for instance, many in the Japanese electronics in- dustries) began to introduce some ...

  3. Synthetic lead bromapatite: X-ray structure at ambient pressure and compressibility up to about 20 GPa

    Science.gov (United States)

    Liu, Xi; Fleet, Michael E.; Shieh, Sean R.; He, Qiang

    2011-05-01

    Lead bromapatite [Pb10(PO4)6Br2] has been synthesized via solid-state reaction at pressures up to 1.0 GPa, and its structure determined by single-crystal X-ray diffraction at ambient temperature and pressure. The large bromide anion is accommodated in the c-axis channel by lateral displacements of structural elements, particularly of Pb2 cations and PO4 tetrahedra. The compressibility of bromapatite was also investigated up to about 20.7 GPa at ambient temperature, using a diamond-anvil cell and synchrotron X-ray radiation. The compressibility of lead bromapatite is significantly different from that of lead fluorapatite. The pressure-volume data of lead bromapatite ( P < 10 GPa) fitted to the third-order Birch-Murnaghan equation yield an isothermal bulk modulus ( K T ) of 49.8(16) GPa and first pressure derivative ( KT^' } ) of 10.1(10). If KT^' } is fixed at 4, the derived K T is 60.8(11) GPa. The relative difference of the bulk moduli of these two lead apatites is thus about 12%, which is about two times the relative difference of the bulk moduli (~5%) of the calcium apatites fluorapatite [Ca10(PO4)6F2], chlorapatite [Ca10(PO4)6Cl2] and hydroxylapatite [Ca10(PO4)6(OH)2]. Another interesting feature apparently related to the replacement of F by Br in lead apatite is the switch in the principle axes of the strain ellipsoid: the c-axis is less compressible than the a-axis in lead bromapatite but more compressible in lead fluorapatite.

  4. Adsorption of copper, nickel and lead ions from synthetic semiconductor industrial wastewater by palm shell activated carbon

    International Nuclear Information System (INIS)

    Onundi, Y. B.; Mamun, A. A.; Al Khatib, M. F.; Ahmad, Y. M.

    2010-01-01

    Granular activated carbon produced from palm kernel shell was used as adsorbent to remove copper, nickel and lead ions from a synthesized industrial wastewater. Laboratory experimental investigation was carried out to identify the effect of p H and contact time on adsorption of lead, copper and nickel from the mixed metals solution. Equilibrium adsorption experiments at ambient room temperature were carried out and fitted to Langmuir and Freundlich models. Results showed that p H 5 was the most suitable, while the maximum adsorbent capacity was at a dosage of 1 g/L, recording a sorption capacity of 1.337 mg/g for lead, 1.581 mg/g for copper and 0.130 mg/g for nickel. The percentage metal removal approached equilibrium within 30 minutes for lead, 75 minutes for copper and nickel, with lead recording 100 p ercent , copper 97 p ercent a nd nickel 55 p ercent r emoval, having a trend of Pb 2+ > Cu 2+ > Ni 2+ . Langmuir model had higher R 2 values of 0.977, 0.817 and 0.978 for copper, nickel and lead respectively, which fitted the equilibrium adsorption process more than Freundlich model for the three metals.

  5. Systems studies of dual purpose electric/synthetic fuels fusion plants

    International Nuclear Information System (INIS)

    Beardsworth, E.; Powell, J.

    1975-02-01

    A reactor power plant is proposed that can meet base load electrical demand, while the remainder can generate synthetic fuels and meet intermittent electrical demands. Two principal objectives of this study are: (1) to examine how strongly various economic demand and resource factors affect the amount of installed CTR capacity, and (2) to examine what increase in CTR capacity can be expected with dual purpose electric/synthetic fuel fusion plants, and also the relative importance of the different production modes

  6. Study of sorption processes of copper on synthetic hydroxyapatite

    International Nuclear Information System (INIS)

    Rosskopfova, O.; Galambos, M.; Ometakova, J.; Rajec, P.; Caplovicova, M.

    2012-01-01

    The sorption of copper on synthetic hydroxyapatite was investigated using a batch method and radiotracer technique. The hydroxyapatite sample prepared by a wet precipitation process was of high crystallinity with Ca/P ratio of 1.688. The sorption of copper on hydroxyapatite was pH independent ranging from 4 to 6 as a result of buffering properties of hydroxyapatite. The adsorption of copper was rapid and the percentage of Cu sorption was >98% during the first 15-30 min of the contact time. The experimental data for sorption of copper have been interpreted in the term of Langmuir isotherm. The sorption of Cu 2+ ions was performed by ion-exchange with Ca 2+ cations on the crystal surface of hydroxyapatite under experimental conditions. The competition effect of Zn 2+ , Fe 2+ and Pb 2+ towards Cu 2+ sorption was stronger than that of Co 2+ , Ni 2+ and Ca 2+ ions. The ability of the bivalent cations to depress the sorption of copper on hydroxyapatite was in the following order Pb 2+ > Fe 2+ > Zn 2+ > Co 2+ ∼ Ni 2+ . (author)

  7. Study of sorption processes of strontium on the synthetic hydroxyapatite

    International Nuclear Information System (INIS)

    Rosskopfova, O.; Galambos, M.; Rajec, P.

    2011-01-01

    The sorption of strontium on synthetic hydroxyapatite was investigated using batch method and radiotracer technique. The hydroxyapatite samples were prepared by a wet precipitation process followed by calcination of calcium phosphate that precipitated from aqueous solution. Also, commercial hydroxyapatites were used. The sorption of strontium on hydroxyapatite depended on the method of preparation and it was pH independent ranging from 4 to 9 as a result of buffering properties of hydroxyapatite. The distribution coefficient K d was significantly decreased with increasing concentration of Sr 2+ and Ca 2+ ions in solution with concentration above 1 x 10 -3 mol dm -3 . The percentage strontium sorption for commercial and by wet method prepared hydroxyapatite was in the range of 83-96%, while calcined hydroxyapatite was ranging from 10 to 30%. The experimental data for sorption of strontium have been interpreted in the term of Langmuir isotherm. The sorption of Sr 2+ ions was performed by ion-exchange with Ca 2+ cations on the crystal surface of hydroxyapatite. Although calcined hydroxyapatite is successfully used as biomaterial for hard tissues repair, it is not used for the treatment of liquid wastes. (author)

  8. Numerical generation and study of synthetic bainitic microstructures

    International Nuclear Information System (INIS)

    Osipov, N.; Gourgues-Lorenzon, A.F.; Cailletaud, G.; Diard, O.; Marini, B.

    2006-01-01

    Models classically used to describe the probability of brittle fracture in nuclear power plants are written on the macroscopic scale. Its is not easy to surely capture the physical phenomena in such a type of approach, so that the application of the models far from their identification domain (temperature history, loading path) may become questionable. To improve the quality of the prediction of resistance and life time, microstructural information, describing the heterogeneous character of the material and its deformation mechanisms has to be taken into consideration. This paper is devoted to 16MND5 bainitic steel. Bainitic packets grow in former austenitic grains, and are not randomly oriented. Knowing the macroscopic stress is thus not sufficient to describe the stress-strain state in ferrite. An accurate model must take into account the actual microstructure, in order to provide realistic local stress and strain fields, to be used as inputs of a new class of cleavage models based on the local behavior. The paper shows the approach used to generate a synthetic microstructure and demonstrates that the resulting morphologies present a quantitative agreement with the experimental images. (authors)

  9. Thermodynamic studies on charge-coupled substituted synthetic monazite

    Energy Technology Data Exchange (ETDEWEB)

    Rawat, D. [Product Development Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Phapale, S. [Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Mishra, R., E-mail: mishrar@barc.gov.in [Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Dash, S. [Product Development Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2017-04-15

    Phosphate-based monazite ceramic is considered worldwide as a potential crystalline host matrix for immobilization of long-lived tri- and tetra-valent actinides present in high-level nuclear waste. Monazite is chemically stable with respect to the leaching processes and has high radiation stability. The present paper describes the influence of charged coupled (Ca{sup 2+}, Th{sup 4+}) substitution in place of La{sup 3+} on thermodynamic stability of synthetic monazite ceramics. XRD-analysis of Ca, Th substituted LaPO{sub 4} viz., La{sub 1-x}Ca{sub x/2}Th{sub x/2}PO{sub 4} (0 ≤ x ≤ 1) points to the formation of ideal solid-solution in the entire range of composition. However, thermodynamic analysis indicates deviation from ideal solid-solution with a minima at x = 0.25. The substituted La{sub 1-x}Ca{sub x/2}Th{sub x/2}PO{sub 4} system is found to be iso-entropic and stabilized mainly by enthalpy. Enthalpies of formation as a function of Ca{sup 2+}, Th{sup 4+} substitution were analysed to provide insights into the development of thermodynamically stable nuclear waste matrix.

  10. Full-thickness skin graft vs. synthetic mesh in the repair of giant incisional hernia: a randomized controlled multicenter study.

    Science.gov (United States)

    Clay, L; Stark, B; Gunnarsson, U; Strigård, K

    2018-04-01

    Repair of large incisional hernias includes the implantation of a synthetic mesh, but this may lead to pain, stiffness, infection and enterocutaneous fistulae. Autologous full-thickness skin graft as on-lay reinforcement has been tested in eight high-risk patients in a proof-of-concept study, with satisfactory results. In this multicenter randomized study, the use of skin graft was compared to synthetic mesh in giant ventral hernia repair. Non-smoking patients with a ventral hernia > 10 cm wide were randomized to repair using an on-lay autologous full-thickness skin graft or a synthetic mesh. The primary endpoint was surgical site complications during the first 3 months. A secondary endpoint was patient comfort. Fifty-three patients were included. Clinical evaluation was performed at a 3-month follow-up appointment. There were fewer patients in the skin graft group reporting discomfort: 3 (13%) vs. 12 (43%) (p = 0.016). Skin graft patients had less pain and a better general improvement. No difference was seen regarding seroma; 13 (54%) vs. 13 (46%), or subcutaneous wound infection; 5 (20%) vs. 7 (25%). One recurrence appeared in each group. Three patients in the skin graft group and two in the synthetic mesh group were admitted to the intensive care unit. No difference was seen for the primary endpoint short-term surgical complication. Full-thickness skin graft appears to be a reliable material for ventral hernia repair producing no more complications than when using synthetic mesh. Patients repaired with a skin graft have less subjective abdominal wall symptoms.

  11. 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...Genderen, H. and Vink, H.H. (1972), Br. J, Cancer , 16, 219. Van Esch, G.J. and Kroes, R. (1969), "The Induction of Renal Tumours by Feeding Basic...Lead Acetate to Mice and Hamsters," Br, J. Cancer , 23(4), 765-771. » Verberk, M.M. (1976), "Motor Nerve Conduction Velocity in Volunteers Ingest

  12. Evaluation of natural clay Brasgel as adsorbent in removal of lead in synthetic waste water; Avaliacao da argila Brasgel natural como adsorvente na remocao de chumbo de efluentes sinteticos

    Energy Technology Data Exchange (ETDEWEB)

    Lima, W.S.; Rodrigues, M.G.F.; Mota, M.F.; Patricio, A.C.L.; Silva, M.M., E-mail: wsl_20@yahoo.com.br [Universidade Federal de Campina Grande (LABNOV/UFCG), PB (Brazil). Unidade Academica de Engenharia Quimica. Lab. de Desenvolvimento de Novos Materiais

    2012-07-01

    The smectite clays have high adsorption capacity and cation exchange. Due to its chemical and physical characteristics, they can be effectively used as adsorbent of pollutants (such as metal ions). The initial objective of this study was to characterize the clay Brasgel through the techniques of X-Ray Diffraction (XRD), X-Ray Spectrometry by Energy Dispersive (EDX) and nitrogen adsorption (BET method), seeking its use in removing lead (Pb{sup 2+}) from synthetic effluents. System was used in finite bath to assess the potential removal of lead (Pb{sup 2+}), following a 2{sup 2} factorial experimental design with three center point experiments, taking as input variables: pH and initial concentrations of lead (Pb{sup 2+}). The clay has Brasgel clay in its composition that characterize it as a smectite clay. By having a large surface area, this clay showed great potential on the adsorption of metal ions. (author)

  13. Effects of confinement on rock mass modulus: A synthetic rock mass modelling (SRM study

    Directory of Open Access Journals (Sweden)

    I. Vazaios

    2018-06-01

    Full Text Available The main objective of this paper is to examine the influence of the applied confining stress on the rock mass modulus of moderately jointed rocks (well interlocked undisturbed rock mass with blocks formed by three or less intersecting joints. A synthetic rock mass modelling (SRM approach is employed to determine the mechanical properties of the rock mass. In this approach, the intact body of rock is represented by the discrete element method (DEM-Voronoi grains with the ability of simulating the initiation and propagation of microcracks within the intact part of the model. The geometry of the pre-existing joints is generated by employing discrete fracture network (DFN modelling based on field joint data collected from the Brockville Tunnel using LiDAR scanning. The geometrical characteristics of the simulated joints at a representative sample size are first validated against the field data, and then used to measure the rock quality designation (RQD, joint spacing, areal fracture intensity (P21, and block volumes. These geometrical quantities are used to quantitatively determine a representative range of the geological strength index (GSI. The results show that estimating the GSI using the RQD tends to make a closer estimate of the degree of blockiness that leads to GSI values corresponding to those obtained from direct visual observations of the rock mass conditions in the field. The use of joint spacing and block volume in order to quantify the GSI value range for the studied rock mass suggests a lower range compared to that evaluated in situ. Based on numerical modelling results and laboratory data of rock testing reported in the literature, a semi-empirical equation is proposed that relates the rock mass modulus to confinement as a function of the areal fracture intensity and joint stiffness. Keywords: Synthetic rock mass modelling (SRM, Discrete fracture network (DFN, Rock mass modulus, Geological strength index (GSI, Confinement

  14. Lead preconcentration in synthetic samples with triton x-114 in the cloud point extraction and analysis by atomic absorption (EAAF)

    International Nuclear Information System (INIS)

    Zegarra Pisconti, Marixa; Cjuno Huanca, Jesus

    2015-01-01

    A methodology was developed about lead preconcentration in water samples that were added dithizone as complexing agent, previously dissolved in the nonionic surfactant Triton X-114, until the formation of the critical micelle concentration and the cloud point temperature. The centrifuged system gave a precipitate with high concentrations of Pb (II) that was measured by atomic absorption spectroscopy with flame (EAAF). The method has proved feasible to be implemented as a method of preconcentration and analysis of Pb in aqueous samples with concentrations less than 1 ppm. Several parameters were evaluated to obtain a percentage recovery of 89.8%. (author)

  15. [Study on lead absorption in pumpkin by atomic absorption spectrophotometry].

    Science.gov (United States)

    Li, Zhen-Xia; Sun, Yong-Dong; Chen, Bi-Hua; Li, Xin-Zheng

    2008-07-01

    A study was carried out on the characteristic of lead absorption in pumpkin via atomic absorption spectrophotometer. The results showed that lead absorption amount in pumpkin increased with time, but the absorption rate decreased with time; And the lead absorption amount reached the peak in pH 7. Lead and cadmium have similar characteristic of absorption in pumpkin.

  16. Some studies of maternal and infant lead exposure in Glasgow

    Energy Technology Data Exchange (ETDEWEB)

    Moore, M.R.; Goldberg, A.; Pocock, S.J.; Meredith, A.; Stewart, I.M.; MacAnespie, H.; Lees, R.; Low, A.

    1982-04-01

    In two studies in the city of Glasgow, 236 mothers and their newly born infants and 117 mothers and their 6-weeks old children's environmental lead exposure were examined. In both studies blood lead concentrations were found to correlate significantly with the cube root of the domestic water lead concentrations. In the first study, multiple regression analyses of maternal blood lead and cord blood lead concentrations on other variables showed a significant negative correlation with gestational age. It was also noted that there was an annual fluctuation in maternal blood lead concentration with highest values in the autumn. In the second study, similar relationships were found. Although there was no association between blood lead and sex, age, place of birth or feeding method, as in the previous study, a significant association between social class and blood lead was found. This could be explained on the basis of the significant correlation between water lead and social class. In those mothers who breast fed, breast milk lead concentrations were found to correlate significantly with blood lead concentrations where breast milk lead was around one tenth of blood lead concentration. These studies emphasise the importance of water lead in the economy of environmental lead exposure to mothers and their unborn and newly born infants.

  17. Atomic force microscopy analysis of synthetic membranes applied in release studies

    Energy Technology Data Exchange (ETDEWEB)

    Olejnik, Anna, E-mail: annamar@amu.edu.pl; Nowak, Izabela

    2015-11-15

    Graphical abstract: - Highlights: • We compare eight synthetic membranes by atomic force microscopy. • We predict the behavior of membranes in the release experiments. • The polymeric synthetic membranes varied in shape and size. • We detect substructures in pores of cellulose esters and nylon membranes. • Substructures limit the release rate of active compound. - Abstract: Synthetic membranes are commonly used in drug release studies and are applied mostly in quality control. They contain pores through which the drug can be diffused directly into the receptor fluid. Investigation of synthetic membranes permits determination of their structure and characterization of their properties. We suggest that the preliminary characterization of the membranes can be relevant to the interpretation of the release results. The aim of this study was to compare eight synthetic membranes by using atomic force microscopy in order to predict and understand their behavior in the release experiments. The results proved that polytetrafluoroethylene membrane was not suitable for the release study of tetrapeptide due to its hydrophobic nature, thickness and the specific structure with high trapezoid shaped blocks. The additional substructures in pores of mixed cellulose esters and nylon membranes detected by AFM influenced the diffusion rate of the active compound. These findings indicate that the selection of the membrane for the release studies should be performed cautiously by taking into consideration the membrane properties and by analyzing them prior the experiment.

  18. Atomic force microscopy analysis of synthetic membranes applied in release studies

    International Nuclear Information System (INIS)

    Olejnik, Anna; Nowak, Izabela

    2015-01-01

    Graphical abstract: - Highlights: • We compare eight synthetic membranes by atomic force microscopy. • We predict the behavior of membranes in the release experiments. • The polymeric synthetic membranes varied in shape and size. • We detect substructures in pores of cellulose esters and nylon membranes. • Substructures limit the release rate of active compound. - Abstract: Synthetic membranes are commonly used in drug release studies and are applied mostly in quality control. They contain pores through which the drug can be diffused directly into the receptor fluid. Investigation of synthetic membranes permits determination of their structure and characterization of their properties. We suggest that the preliminary characterization of the membranes can be relevant to the interpretation of the release results. The aim of this study was to compare eight synthetic membranes by using atomic force microscopy in order to predict and understand their behavior in the release experiments. The results proved that polytetrafluoroethylene membrane was not suitable for the release study of tetrapeptide due to its hydrophobic nature, thickness and the specific structure with high trapezoid shaped blocks. The additional substructures in pores of mixed cellulose esters and nylon membranes detected by AFM influenced the diffusion rate of the active compound. These findings indicate that the selection of the membrane for the release studies should be performed cautiously by taking into consideration the membrane properties and by analyzing them prior the experiment.

  19. A PLIF and PIV study of liquid mixing enhanced by a lateral synthetic jet pair

    International Nuclear Information System (INIS)

    Xia Qingfeng; Zhong Shan

    2012-01-01

    Highlights: ► Enhancement of mixing between two water streams in a planar channel by means of a lateral synthetic jet pair is studied using PLIF and PIV. ► The excellent mixing observed is largely caused by a strong interaction between the opposing vortex pairs produced by the lateral synthetic jets. ► The synthetic jet operating conditions, at which a nearly homogenous mixing is achieved, are also identified and they are expressed in terms of a functional relationship. - Abstract: In this paper, enhancement of mixing between two water streams of the same flow rate in a planar channel by means of a lateral synthetic jet pair is studied at a net flow Reynolds number of 83 using PLIF and PIV. The synthetic jet pair is operated 180° out-of-phase at a range of actuation frequencies and displacements, with the latter being characterized by the dimensionless stroke length. The extent of mixing is evaluated using PLIF data at a location further downstream in the mixing channel. It is found that at a fixed actuation frequency a higher dimensionless stroke length produces a better mixing, and as the actuation frequency increases a lower dimensionless stroke length is required to achieve a given mixing degree. At a sufficiently high frequency or dimensionless stroke length, a nearly homogenous mixing with a mixing degree greater than 0.9 can be obtained. A functional relationship between actuation frequency and dimensionless stroke length is also obtained by best fitting the experimental data, which can be used for selecting the synthetic jet operating conditions to ensure a good mixing. Furthermore, both PLIF and PIV results show that each synthetic jet actuation cycle produce two opposing vortex pairs, which play an important role in prompting mixing between the two fluid streams. The excellent mixing obtained at a high frequency or a high dimensionless stroke length is found to be largely caused by a strong interaction between these opposing vortex pairs.

  20. ATM loss leads to synthetic lethality in BRCA1 BRCT mutant mice associated with exacerbated defects in homology-directed repair.

    Science.gov (United States)

    Chen, Chun-Chin; Kass, Elizabeth M; Yen, Wei-Feng; Ludwig, Thomas; Moynahan, Mary Ellen; Chaudhuri, Jayanta; Jasin, Maria

    2017-07-18

    BRCA1 is essential for homology-directed repair (HDR) of DNA double-strand breaks in part through antagonism of the nonhomologous end-joining factor 53BP1. The ATM kinase is involved in various aspects of DNA damage signaling and repair, but how ATM participates in HDR and genetically interacts with BRCA1 in this process is unclear. To investigate this question, we used the Brca1 S1598F mouse model carrying a mutation in the BRCA1 C-terminal domain of BRCA1. Whereas ATM loss leads to a mild HDR defect in adult somatic cells, we find that ATM inhibition leads to severely reduced HDR in Brca1 S1598F cells. Consistent with a critical role for ATM in HDR in this background, loss of ATM leads to synthetic lethality of Brca1 S1598F mice. Whereas both ATM and BRCA1 promote end resection, which can be regulated by 53BP1, 53bp1 deletion does not rescue the HDR defects of Atm mutant cells, in contrast to Brca1 mutant cells. These results demonstrate that ATM has a role in HDR independent of the BRCA1-53BP1 antagonism and that its HDR function can become critical in certain contexts.

  1. Synthetic tambjamine analogues induce mitochondrial swelling and lysosomal dysfunction leading to autophagy blockade and necrotic cell death in lung cancer.

    Science.gov (United States)

    Rodilla, Ananda M; Korrodi-Gregório, Luís; Hernando, Elsa; Manuel-Manresa, Pilar; Quesada, Roberto; Pérez-Tomás, Ricardo; Soto-Cerrato, Vanessa

    2017-02-15

    Current pharmacological treatments for lung cancer show very poor clinical outcomes, therefore, the development of novel anticancer agents with innovative mechanisms of action is urgently needed. Cancer cells have a reversed pH gradient compared to normal cells, which favours cancer progression by promoting proliferation, metabolic adaptation and evasion of apoptosis. In this regard, the use of ionophores to modulate intracellular pH appears as a promising new therapeutic strategy. Indeed, there is a growing body of evidence supporting ionophores as novel antitumour drugs. Despite this, little is known about the implications of pH deregulation and homeostasis imbalance triggered by ionophores at the cellular level. In this work, we deeply analyse for the first time the anticancer effects of tambjamine analogues, a group of highly effective anion selective ionophores, at the cellular and molecular levels. First, their effects on cell viability were determined in several lung cancer cell lines and patient-derived cancer stem cells, demonstrating their potent cytotoxic effects. Then, we have characterized the induced lysosomal deacidification, as well as, the massive cytoplasmic vacuolization observed after treatment with these compounds, which is consistent with mitochondrial swelling. Finally, the activation of several proteins involved in stress response, autophagy and apoptosis was also detected, although they were not significantly responsible for the cell death induced. Altogether, these evidences suggest that tambjamine analogues provoke an imbalance in cellular ion homeostasis that triggers mitochondrial dysfunction and lysosomal deacidification leading to a potent cytotoxic effect through necrosis in lung cancer cell lines and cancer stem cells. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Imouraren mining exploitation : Complementary studies Synthetic report Volum B - Mines

    International Nuclear Information System (INIS)

    1980-01-01

    The object of the current study is to determine the main technical characteristics of the reference project of a mine that can supply the necessary ore quantity at a production of 3000 tonnes uranium per year, along 10 years. The project is one of the possible solutions for exploiting the mine. The current study permits to establish : investment and functioning cost estimation, overall project of the mining exploitation program, necessary strength estimation, average ore grades evaluation and variations of these grades, utilities needs, production vizing program, main exploitation methods and necessary materials. Reference project study of the mine serves as base to the economics studies and studies optimization [fr

  3. Influencing Gameplay in Support of Early Synthetic Prototyping Studies

    Science.gov (United States)

    2016-06-01

    Action Review AI Artificial Intelligence AR Army Regulation ARCIC Army Capabilities Integration Center ASA(ALT) Assistant Secretary of the Army...actions of the participant and the performance of artificial intelligence (AI). The study attempted to control unwanted variability from study...wheeled armored transportation with a 25mm cannon. Your armor can provide protection against direct fire up to .50-caliber ammunition. Intelligence

  4. Preliminary study of synthetic aperture tissue harmonic imaging on in-vivo data

    DEFF Research Database (Denmark)

    Rasmussen, Joachim Hee; Hemmsen, Martin Christian; Sloth Madsen, Signe

    2013-01-01

    . Results from the image quality study show, that in the current configuration on the UltraView system, where no transmit apodization was applied, SASB-THI and DRF-THI produced equally good images. It is expected that given the use of transmit apodization, SASB-THI could be further improved.......A method for synthetic aperture tissue harmonic imaging is investigated. It combines synthetic aperture sequential beamforming (SASB) with tissue harmonic imaging (THI) to produce an increased and more uniform spatial resolution and improved side lobe reduction compared to conventional B......-mode imaging. Synthetic aperture sequential beamforming tissue harmonic imaging (SASB-THI) was implemented on a commercially available BK 2202 Pro Focus UltraView ultrasound system and compared to dynamic receive focused tissue harmonic imaging (DRF-THI) in clinical scans. The scan sequence...

  5. A study of positron properties in quartz crystals and synthetic silica glass

    International Nuclear Information System (INIS)

    Anwand, W.; Brauer, G.; Hesegawa, M.; Dersch, O.; Rauch, F.

    2001-01-01

    The monoenergetic positron beamline 'SPONSOR' at Rossendorf has been used to investigate the positron behaviour in a naturally grown Brasilian quartz, two synthetic quartz crystals of different origin, and synthetic silica glass. The measurements allow us to obtain the positron diffusion length of free positrons and Bloch para-positronium, if formed, in these materials. In addition, hydrothermal treatment of a synthetic quartz has been used to introduce hydrogen into the crystal up to a certain depth. The presence of hydrogen is found to influence the formation of para-positronium. The depth distribution of hydrogen has been measured independently by the nuclear reaction analysis, and will be discussed in comparison with the results deduced from the positron studies. (author)

  6. Synthetic Study on the Geological and Hydrogeological Model around KURT

    International Nuclear Information System (INIS)

    Park, Kyung Woo; Kim, Kyung Su; Koh, Yong Kwon; Choi, Jong Won

    2011-01-01

    To characterize the site specific properties of a study area for high-level radioactive waste disposal research in KAERI, the several geological investigations such as surface geological surveys and borehole drillings were carried out since 1997. Especially, KURT (KAERI Underground Research Tunnel) was constructed to understand the further study of geological environments in 2006. As a result, the first geological model of a study area was constructed by using the results of geological investigation. The objective of this research is to construct a hydrogeological model around KURT area on the basis of the geological model. Hydrogeological data which were obtained from in-situ hydraulic tests in the 9 boreholes were estimated to accomplish the objective. And, the hydrogeological properties of the 4 geological elements in the geological model, which were the subsurface weathering zone, the log angle fracture zone, the fracture zones and the bedrock were suggested. The hydrogeological model suggested in this study will be used as input parameters to carry out the groundwater flow modeling as a next step of the site characterization around KURT area

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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

  8. Radioisotopic and synthetic studies related to caroxazone metabolism in man

    International Nuclear Information System (INIS)

    Bernardi, L.; Coda, S.; Nicolella, V.; Vicario, G.P.; Gioia, B.; Minghetti, A.; Vigevani, A.; Arcamone, F.

    1979-01-01

    Labelled 2-oxo-2H-1,3-benzoxazine-3(4H)-acetamide (caroxazone), has been synthesized by condensing N-(2-hydroxylbenzyl) glycinamide with 14 C phosgene. Metabolic studies were performed administering the labelled drug to man and recovering metabolites were identified and confirmed by synthesis, namely (3,4-dihydro - 3-carboxamidomethyl-2-oxo-2H - 1,3-benzoxazin-4-yl) urea (IX), N-carboxamidomethyl o-hydroxymethylphenyl carbamate (V), 4-methoxy-2-oxo-2H - 1,3-benzoxazine-3(4H) acetamide (VIIIa), 2-oxo-2H - 1,3-benzoxazine-3(4H) acetic acid (III) and 4-hydroxy-2-oxo-2H-1,3-benzoxazine-3(4H) acetamide (IV). (orig.) 891 AJ/orig. 892 GR [de

  9. Impinging jet study of the deposition of colloidal particles on synthetic polymer (Zeonor)

    DEFF Research Database (Denmark)

    Vlček, Jakub; Lapčík, Lubomír; Cech, Jiri

    2014-01-01

    In this study, an impinging jet deposition experiments were performed on synthetic polymer (Zeonor) original and by micro-embossing modified substrates with exactly defined topology as confirmed by AFM and SEM. Deposition experiments were performed at ambient temperature and at selected flow regi...

  10. Oral two-generation reproduction toxicity study with NM-200 synthetic amorphous silica in Wistar rats

    NARCIS (Netherlands)

    Wolterbeek, A.; Oosterwijk, T.; Schneider, S.; Landsiedel, R.; Groot, D. de; Ee, R. van; Wouters, M.; Sandt, H. van de

    2015-01-01

    Synthetic amorphous silica (SAS) like NM-200 is used in a wide variety of technological applications and consumer products. Although SAS has been widely investigated the available reproductive toxicity studies are old and do not cover all requirements of current OECD Guidelines. As part of a

  11. Methodological issues related to studies of lead mobilization during menopause

    Directory of Open Access Journals (Sweden)

    Berkowitz Gertrud S.

    1999-01-01

    Full Text Available While there has been a substantial decline in lead exposure in the United States during the past two decades, mobilization of existing lead stored in bone potentially represents an important endogenous source of exposure for menopausal women. It has been hypothesized that lead may be mobilized from skeletal stores during conditions of high bone turnover, such as during menopause. However, such mobilization has not been documented in prospective studies. This discussion is focussed on some of the methodological difficulties to be anticipated in longitudinal studies of lead mobilization specific to menopause and the issues that need to be taken into account when evaluating the results of such studies. To evaluate whether lead mobilization occurs during menopause, a prospective repeated measures design is needed using X-ray fluorescence analysis of lead in bone and serial measurements of blood lead. Potential confounders and effect modifiers also need to be taken into account in the statistical analysis.

  12. An Experimental Study on Active Flow Control Using Synthetic Jet Actuators over S809 Airfoil

    International Nuclear Information System (INIS)

    Gul, M; Uzol, O; Akmandor, I S

    2014-01-01

    This study investigates the effect of periodic excitation from individually controlled synthetic jet actuators on the dynamics of the flow within the separation and re-attachment regions of the boundary layer over the suction surface of a 2D model wing that has S809 airfoil profile. Experiments are performed in METUWIND's C3 open-loop suction type wind tunnel that has a 1 m × 1 m cross-section test section. The synthetic jet array on the wing consists of three individually controlled actuators driven by piezoelectric diaphragms located at 28% chord location near the mid-span of the wing. In the first part of the study, surface pressure, Constant Temperature Anemometry (CTA) and Particle Image Velocimetry (PIV) measurements are performed over the suction surface of the airfoil to determine the size and characteristics of the separated shear layer and the re-attachment region, i.e. the laminar separation bubble, at 2.3x10 5 Reynolds number at zero angle of attack and with no flow control as a baseline case. For the controlled case, CTA measurements are carried out under the same inlet conditions at various streamwise locations along the suction surface of the airfoil to investigate the effect of the synthetic jet on the boundary layer properties. During the controlled case experiments, the synthetic jet actuators are driven with a sinusoidal frequency of 1.45 kHz and 300Vp-p. Results of this study show that periodic excitation from the synthetic jet actuators eliminates the laminar separation bubble formed over the suction surface of the airfoil at 2.3x10 5 Reynolds number at zero angle of attack

  13. Synthetic activity of rat blood lymphocytes under acute and continuous gamma-irradiation - fluorescent microspectral study

    International Nuclear Information System (INIS)

    Karnaukhova, N.A.; Sergiyevich, L.A.; Aksenova, G.Y.; Karnaukhov, V.N.

    1999-01-01

    The effects of different doses of acute and continuous gamma-irradiation on the synthetic activity of rat blood lymphocytes stained with acridine orange were studied by fluorescent microspectrometry. Male rats were exposed to acute gamma-irradiation with doses of 7.5, 4 and 3 Gy, or to continuous irradiation with dose rates of 14.4, 2.1, 1.1 and 0.43 cGy/day, respectively. The changes of the synthetic activity of blood lymphocytes occurred in three main stages after acute gamma-irradiation and in four stages under continuous irradiation. The stages reflect the processes of depression and activation of the immune system under irradiation. Essential differences between the acute and continuous effects were observed in the first stage. After acute gamma-irradiation, the synthetic activity decreased sharply, indicating the predominant contribution of the damaging effect of irradiation, whereas under continuous irradiation, as a result of the stimulatory effect of low-dose irradiation, the synthetic activity increased during the first stage. (orig.)

  14. Drop amalgam voltammetric study of lead complexation by natural ...

    African Journals Online (AJOL)

    A study of inorganic complexation of lead using drop amalgam voltammetry is described. The study has been carried out in simulated salt lake water and at ionic strength of 7.35 M, the predetermined ionic strength of Lake Katwe. The complexation of lead with the simple ligands (Cl-, CO32-) created anodic waves and the ...

  15. Towards a synthetic chloroplast.

    Directory of Open Access Journals (Sweden)

    Christina M Agapakis

    2011-04-01

    Full Text Available The evolution of eukaryotic cells is widely agreed to have proceeded through a series of endosymbiotic events between larger cells and proteobacteria or cyanobacteria, leading to the formation of mitochondria or chloroplasts, respectively. Engineered endosymbiotic relationships between different species of cells are a valuable tool for synthetic biology, where engineered pathways based on two species could take advantage of the unique abilities of each mutualistic partner.We explored the possibility of using the photosynthetic bacterium Synechococcus elongatus PCC 7942 as a platform for studying evolutionary dynamics and for designing two-species synthetic biological systems. We observed that the cyanobacteria were relatively harmless to eukaryotic host cells compared to Escherichia coli when injected into the embryos of zebrafish, Danio rerio, or taken up by mammalian macrophages. In addition, when engineered with invasin from Yersinia pestis and listeriolysin O from Listeria monocytogenes, S. elongatus was able to invade cultured mammalian cells and divide inside macrophages.Our results show that it is possible to engineer photosynthetic bacteria to invade the cytoplasm of mammalian cells for further engineering and applications in synthetic biology. Engineered invasive but non-pathogenic or immunogenic photosynthetic bacteria have great potential as synthetic biological devices.

  16. SMM-chemokines: a class of unnatural synthetic molecules as chemical probes of chemokine receptor biology and leads for therapeutic development.

    Science.gov (United States)

    Kumar, Santosh; Choi, Won-Tak; Dong, Chang-Zhi; Madani, Navid; Tian, Shaomin; Liu, Dongxiang; Wang, Youli; Pesavento, James; Wang, Jun; Fan, Xuejun; Yuan, Jian; Fritzsche, Wayne R; An, Jing; Sodroski, Joseph G; Richman, Douglas D; Huang, Ziwei

    2006-01-01

    Chemokines and their receptors play important roles in numerous physiological and pathological processes. To develop natural chemokines into receptor probes and inhibitors of pathological processes, the lack of chemokine-receptor selectivity must be overcome. Here, we apply chemical synthesis and the concept of modular modifications to generate unnatural synthetically and modularly modified (SMM)-chemokines that have high receptor selectivity and affinity, and reduced toxicity. A proof of the concept was shown by transforming the nonselective viral macrophage inflammatory protein-II into new analogs with enhanced selectivity and potency for CXCR4 or CCR5, two principal coreceptors for human immunodeficiency virus (HIV)-1 entry. These new analogs provided insights into receptor binding and signaling mechanisms and acted as potent HIV-1 inhibitors. These results support the concept of SMM-chemokines for studying and controlling the function of other chemokine receptors.

  17. Studies of Cell-Mediated Immunity Against Immune Disorders Using Synthetic Peptides and Rotating Bioreactor System

    Science.gov (United States)

    Sastry, Jagannadha K.

    1997-01-01

    Our proposed experiments included: (1) immunzing mice with synthetic peptides; (2) preparing spleen and lymph node cells; (3) growing them under conventional conditions as well as in the rotatory vessel in appropriate medium reconstituting with synthetic peptides and/or cytokines as needed; and (4) comparing at regular time intervals the specific CTL activity as well as helper T-cell activity (in terms of both proliferative responses and cytokine production) using established procedures in my laboratory. We further proposed that once we demonstrated the merit of rotatory vessel technology to achieve desired results, these studies would be expanded to include immune cells from non-human primates (rhesus monkeys and chimpanzees) and also humans. We conducted a number of experiments to determine CTL induction by the synthetic peptides corresponding to antigenic proteins in HIV and HPV in different mouse strains that express MHC haplotypes H-2b or H-2d. We immunized mice with 100 ug of the synthetic peptide, suspended in sterile water, and emulsified in CFA (1:1). The immune lymph node cells obtained after 7 days were restimulated by culturing in T25 flask, HARV-10, or STLV-50, in the presence of the peptide at 20 ug/ml. The results from the 5'Cr-release assay consistently revealed complete abrogation of CTL activity of cells grown in the bioreactors (both HARV and STLV), while significant antigen-specific CTL activity was observed with cells cultured in tissue culture flasks. Thus, overall the data we generated in this study proved the usefulness of the NASA-developed developed technology for understanding the known immune deficiency during space travel. Additionally, this ex vivo microgravity technology since it mimics effectively the in vivo situation, it is also useful in understanding immune disorders in general. Thus, our proposed studies in TMC-NASA contract round II application benefit from data generated in this TMC-NASA contract round I study.

  18. Comparative Study of the Electrochemical, Biomedical, and Thermal Properties of Natural and Synthetic Nanomaterials

    Science.gov (United States)

    Ghaemi, Ferial; Abdullah, Luqman Chuah; Kargarzadeh, Hanieh; Abdi, Mahnaz M.; Azli, Nur Farhana Waheeda Mohd; Abbasian, Maryam

    2018-04-01

    In this research, natural nanomaterials including cellulose nanocrystal (CNC), nanofiber cellulose (NFC), and synthetic nanoparticles such as carbon nanofiber (CNF) and carbon nanotube (CNT) with different structures, sizes, and surface areas were produced and analyzed. The most significant contribution of this study is to evaluate and compare these nanomaterials based on the effects of their structures and morphologies on their electrochemical, biomedical, and thermal properties. Based on the obtained results, the natural nanomaterials with low dimension and surface area have zero cytotoxicity effects on the living cells at 12.5 and 3.125 μg/ml concentrations of NFC and CNC, respectively. Meanwhile, synthetic nanomaterials with the high surface area around 15.3-21.1 m2/g and significant thermal stability (480 °C-600 °C) enhance the output of electrode by creating a higher surface area and decreasing the current flow resistance.

  19. Sintering study in vertical fixed bed reactor for synthetic aggregate production

    International Nuclear Information System (INIS)

    Quaresma, D.S.; Neves, A.S.S.; Melo, A.O.; Pereira, L.F.S.; Bezerra, P.T.S.; Macedo, E.N.; Souza, J.A.S.

    2017-01-01

    The synthetic aggregates are being employed in civil construction for the reduction of mineral extraction activities. Within this context, the recycling of industrial waste is the basis of the majority of processes to reduce the exploitation of mineral resources. In this work the sintering in a vertical fixed bed reactor for synthetic aggregate production using 20% pellets and 80% charcoal was studied. The pellets were prepared from a mixture containing clay, charcoal and fly ash. Two experiments varying the speed of air sucking were carried out. The material produced was analyzed by X-ray diffraction, scanning electron microscopy, measures of their ceramic properties, and particle size analysis. The results showed that the solid-state reactions, during the sintering process, were efficient and the produced material was classified as coarse lightweight aggregate. The process is interesting for the sintering of aggregates, and can be controlled by composition, particle size, temperature gradient and gaseous flow. (author)

  20. A Canine Arthroscopic Anterior Cruciate Ligament Reconstruction Model for Study of Synthetic Augmentation of Tendon Allografts.

    Science.gov (United States)

    Cook, James L; Smith, Pat; Stannard, James P; Pfeiffer, Ferris; Kuroki, Keiichi; Bozynski, Chantelle C; Cook, Cristi

    2017-09-01

    Novel graft types, fixation methods, and means for augmenting anterior cruciate ligament (ACL) reconstructions require preclinical validation prior to safe and effective clinical application. The objective of this study was to describe and validate a translational canine model for all-inside arthroscopic complete ACL reconstruction using a quadriceps tendon allograft with internal brace (QTIB). With institutional approval, adult research hounds underwent complete transection of the native ACL followed by all-inside ACL reconstruction using the novel QTIB construct with suspensory fixation ( n  = 10). Contralateral knees were used as nonoperated controls ( n  = 10). Dogs were assessed over a 6-month period using functional, diagnostic imaging, gross, biomechanical, and histologic outcome measures required for preclinical animal models. Study results suggest that the novel QTIB construct used for complete ACL reconstruction can provide sustained knee stability and function without the development of premature osteoarthritis in a rigorous and valid preclinical model. The unique configuration of the QTIB construct-the combination of a tendon allograft with a synthetic suture tape internal brace-allowed for an effective biologic-synthetic load-sharing ACL construct. It prevented early failure, allowed for direct, four-zone graft-to-bone healing, and functional graft remodeling while avoiding problems noted with use of all-synthetic grafts. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  1. Preliminary study of synthetic aperture tissue harmonic imaging on in-vivo data

    Science.gov (United States)

    Rasmussen, Joachim H.; Hemmsen, Martin C.; Madsen, Signe S.; Hansen, Peter M.; Nielsen, Michael B.; Jensen, Jørgen A.

    2013-03-01

    A method for synthetic aperture tissue harmonic imaging is investigated. It combines synthetic aperture sequen- tial beamforming (SASB) with tissue harmonic imaging (THI) to produce an increased and more uniform spatial resolution and improved side lobe reduction compared to conventional B-mode imaging. Synthetic aperture sequential beamforming tissue harmonic imaging (SASB-THI) was implemented on a commercially available BK 2202 Pro Focus UltraView ultrasound system and compared to dynamic receive focused tissue harmonic imag- ing (DRF-THI) in clinical scans. The scan sequence that was implemented on the UltraView system acquires both SASB-THI and DRF-THI simultaneously. Twenty-four simultaneously acquired video sequences of in-vivo abdominal SASB-THI and DRF-THI scans on 3 volunteers of 4 different sections of liver and kidney tissues were created. Videos of the in-vivo scans were presented in double blinded studies to two radiologists for image quality performance scoring. Limitations to the systems transmit stage prevented user defined transmit apodization to be applied. Field II simulations showed that side lobes in SASB could be improved by using Hanning transmit apodization. Results from the image quality study show, that in the current configuration on the UltraView system, where no transmit apodization was applied, SASB-THI and DRF-THI produced equally good images. It is expected that given the use of transmit apodization, SASB-THI could be further improved.

  2. Physical, optical and structural studies of copper-doped lead ...

    Indian Academy of Sciences (India)

    2018-05-23

    May 23, 2018 ... Physical, optical and structural studies of copper-doped lead oxychloro ... to the borate glass system increases the Raman scattering cross-section by ..... equations (6) and (7), molar refraction and electronic polariz- ability are ...

  3. Synthetic Rock Analogue for Permeability Studies of Rock Salt with Mudstone

    Directory of Open Access Journals (Sweden)

    Hongwu Yin

    2017-09-01

    Full Text Available Knowledge about the permeability of surrounding rock (salt rock and mudstone interlayer is an important topic, which acts as a key parameter to characterize the tightness of gas storage. The goal of experiments that test the permeability of gas storage facilities in rock salt is to develop a synthetic analogue to use as a permeability model. To address the permeability of a mudstone/salt layered and mixed rock mass in Jintan, Jiangsu Province, synthetic mixed and layered specimens using the mudstone and the salt were fabricated for permeability testing. Because of the gas “slippage effect”, test results are corrected by the Klinkenberg method, and the permeability of specimens is obtained by regression fitting. The results show that the permeability of synthetic pure rock salt is 6.9 × 10−20 m2, and its porosity is 3.8%. The permeability of synthetic mudstone rock is 2.97 × 10−18 m2, with a porosity 17.8%. These results are close to those obtained from intact natural specimens. We also find that with the same mudstone content, the permeability of mixed specimens is about 40% higher than for the layered specimens, and with an increase in the mudstone content, the Klinkenberg permeability increases for both types of specimens. The permeability and mudstone content have a strong exponential relationship. When the mudstone content is below 40%, the permeability increases only slightly with mudstone content, whereas above this threshold, the permeability increases rapidly with mudstone content. The results of the study are of use in the assessment of the tightness of natural gas storage facilities in mudstone-rich rock salt formations in China.

  4. Custom-Made Synthetic Scaffolds for Bone Reconstruction: A Retrospective, Multicenter Clinical Study on 15 Patients

    Directory of Open Access Journals (Sweden)

    Fabrizia Luongo

    2016-01-01

    Full Text Available Purpose. To present a computer-assisted-design/computer-assisted-manufacturing (CAD/CAM technique for the design, fabrication, and clinical application of custom-made synthetic scaffolds, for alveolar ridge augmentation. Methods. The CAD/CAM procedure consisted of (1 virtual planning/design of the custom-made scaffold; (2 milling of the scaffold into the exact size/shape from a preformed synthetic bone block; (3 reconstructive surgery. The main clinical/radiographic outcomes were vertical/horizontal bone gain, any biological complication, and implant survival. Results. Fifteen patients were selected who had been treated with a custom-made synthetic scaffold for ridge augmentation. The scaffolds closely matched the shape of the defects: this reduced the operation time and contributed to good healing. A few patients experienced biological complications, such as pain/swelling (2/15: 13.3% and exposure of the scaffold (3/15: 20.0%; one of these had infection and complete graft loss. In all other patients, 8 months after reconstruction, a well-integrated newly formed bone was clinically available, and the radiographic evaluation revealed a mean vertical and horizontal bone gain of 2.1±0.9 mm and 3.0±1.0 mm, respectively. Fourteen implants were placed and restored with single crowns. The implant survival rate was 100%. Conclusions. Although positive outcomes have been found with custom-made synthetic scaffolds in alveolar ridge augmentation, further studies are needed to validate this technique.

  5. Comparative Study of Ashwagandha and Commercial Synthetic Compound on Performance of Broilers during Hot Weather

    Directory of Open Access Journals (Sweden)

    J. M. Shisodiya

    Full Text Available The trial was conducted for a period of six weeks on 225 day old broiler chicks, uniformly distributed into four groups of 75 chicks in each T1, T2 and T3 group. The chicks were fed with standard starter mash which contained crude protein 22.84% and metabolizable energy 2852.5 Kcal / kg (calculated value up to three weeks of age. For next 3 weeks i.e. from 4 to 6 weeks of age with finisher mash which contained crude protein 20% and metabolizable energy 2966 Kcal / kg (calculated value. Group T1 received standard broiler diet. Group T2 and T3 received standard broiler diet supplemented with Ashwagandha and commercial synthetic compound @ 0.05 % of feed respectively. The experimental birds were reared on deep litter system and rice husk was used as litter material.The supplementation of Aswagandha and commercial synthetic compound recorded significant improvement in all studied growth parameter i.e. live body weights, weekly gain in body weights and feed conversion ratio was observed in all the supplemented groups over the control group. However, feed consumption in control group was significantly higher than supplemented group. The economic returns of supplemented groups are more than the unsupplemented group. The net profit per bird was maximum in the commercial synthetic compound supplemented group followed by Ashwagandha supplemented group and lowest was recorded in control group (T1. [Veterinary World 2008; 1(10.000: 310-311

  6. Adherence to synthetic disease-modifying Antirheumatic Drugs in Rheumatoid Arthritis: Results of the OBSERVAR Study.

    Science.gov (United States)

    Juan Mas, Antonio; Castañeda, Santos; Cantero Santamaría, José I; Baquero, José L; Del Toro Santos, Francisco J

    2017-12-27

    Treatment compliance with disease-modifying antirheumatic drugs (DMARD) is essential to achieve the therapeutic goals in rheumatoid arthritis (RA). However, despite the need for good compliance, there is evidence that patients with RA frequently fail to use DMARD for the control of RA. Thus, the main objective of the OBSERVAR study is to evaluate the reasons for the lack of therapeutic adherence to synthetic DMARD in these patients. A Delphi process involving 18 randomly selected Spanish rheumatologists determined the level of agreement with 66 causes of noncompliance selected from the literature in relation to synthetic DMARD in RA. The reasons for noncompliance were consistent in 75.7%, although 3 reasons (4.5%) were highly consistent: 1) not knowing what to do in the case of an adverse event with DMARD; 2) not having undergone adherence screening by health personnel for early detection of "noncompliant patients"; and 3) not having undergone interventions or strategies that improve adherence. In order to improve adherence to RA treatment with synthetic DMARD, the patient should be adequately informed of each new treatment introduced, the patient's compliance profile should be incorporated into the clinical routine and the patient's motivation for therapeutic compliance be reinforced through the methods available to us. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

  7. Stuck fermentation: development of a synthetic stuck wine and study of a restart procedure.

    Science.gov (United States)

    Maisonnave, Pierre; Sanchez, Isabelle; Moine, Virginie; Dequin, Sylvie; Galeote, Virginie

    2013-05-15

    Stuck fermentation is a major problem in winemaking, resulting in large losses in the wine industry. Specific starter yeasts are used to restart stuck fermentations in conditions determined essentially on the basis of empirical know-how. We have developed a model synthetic stuck wine and an industrial process-based procedure for restarting fermentations, for studies of the conditions required to restart stuck fermentations. We used a basic medium containing 13.5% v/v ethanol and 16 g/L fructose, pH 3.3, to test the effect of various nutrients (vitamins, amino acids, minerals, oligoelements), with the aim of developing a representative and discriminative stuck fermentation model. Cell growth appeared to be a key factor for the efficient restarting of stuck fermentations. Micronutrients, such as vitamins, also strongly affected the efficiency of the restart procedure. For the validation of this medium, we compared the performances of three wine yeast strains in the synthetic stuck fermentation and three naturally stuck wine fermentations. Strain performance was ranked similar in the synthetic medium and in the "Malbec" and "Sauvignon" natural stuck wines. However, two strains were ranked differently in the "Gros Manseng" stuck wine. Nutrient content seemed to be a crucial factor in fermentation restart conditions, generating differences between yeast strains. However, the specific sensitivity of yeast strains to the composition of the wine may also have had an effect. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Impact of home carpets on childhood lead intervention study

    International Nuclear Information System (INIS)

    Yiin, L.-M.; Lioy, P.J.; Rhoads, G.G.

    2003-01-01

    Blood lead data for a childhood lead exposure study have been reanalyzed to examine the impact of carpets on the effectiveness of a cleaning intervention in 39 New Jersey urban houses. All eligible houses in the study were classified as carpeted and uncarpeted depending on the number of rooms that were carpeted. The cleaning protocol was associated with a significant reduction in the blood lead concentrations for the uncarpeted homes (P=0.004), whereas no significant change was found for the carpeted homes (P=0.566). We also completed correlation analyses between the number of cleaning visits and the percentage reduction in blood lead for the carpeted/uncarpeted houses. There was a significant correlation (r=0.67) between the number of cleanings and blood lead reduction for the uncarpeted homes, but no correlation (r=0.04) for the carpeted homes. In a multiple regression model that took confounding variables into account, the carpet status (carpeted or uncarpeted) remained a factor of the effect of cleaning on blood lead (P=0.05). We conclude that the presence of contaminated carpets inhibits the effectiveness of home cleaning despite a high-efficiency particulate air filtered vacuum protocol that removes a substantial amount of lead dust

  9. Optical Studies on Sol-Gel Derived Lead Chloride Crystals

    OpenAIRE

    Rejeena, I; Lillibai, B; Nithyaja, B; Nampoori, P.N V; Radhakrishnan, P

    2013-01-01

    Optical characterization of lead chloride crystals prepared by sol-gel method is reported. The relevant sol-gel technique is used for the preparation of PbCl2 samples with five different types. In this paper, we report the absorption and fluorescence behaviour of pure, UV& IR irradiated and electric & magnetic field applied lead chloride crystal samples in solution phase at two different concentrations. Optical bandgap and emission studies of these crystals are also done.

  10. Enhanced heavy oil recovery for carbonate reservoirs integrating cross-well seismic–a synthetic Wafra case study

    KAUST Repository

    Katterbauer, Klemens; Arango, Santiago; Sun, Shuyu; Hoteit, Ibrahim

    2015-01-01

    reservoir history matching framework using ensemble based techniques incorporating seismic data for enhancing reservoir characterization and improving history matches. Examining the performance on a synthetic field study of the Wafra field, we could

  11. Combined X-ray and neutron fibre diffraction studies of biological and synthetic polymers

    International Nuclear Information System (INIS)

    Parrot, I.M.; Urban, V.; Gardner, K.H.; Forsyth, V.T.

    2005-01-01

    The fibrous state is a natural one for polymer molecules which tend to assume regular helical conformations rather than the globular structures characteristic of many proteins. Fibre diffraction therefore has broad application to the study of a wide range of biological and synthetic polymers. The purpose of this paper is to illustrate the general scope of the method and in particular to demonstrate the impact of a combined approach involving both X-ray and neutron diffraction methods. While the flux of modern X-ray synchrotron radiation sources allows high quality datasets to be recorded with good resolution within a very short space of time, neutron studies can provide unique information through the ability to locate hydrogen or deuterium atoms that are often difficult or impossible to locate using X-ray methods. Furthermore, neutron fibre diffraction methods can, through the ability to selectively label specific parts of a structure, be used to highlight novel aspects of polymer structure that can not be studied using X-rays. Two examples are given. The first describes X-ray and neutron diffraction studies of conformational transitions in DNA. The second describes structural studies of the synthetic high-performance polymer poly(p-phenylene terephthalamide) (PPTA), known commercially as Kevlar[reg] or Twaron[reg

  12. Combined X-ray and neutron fibre diffraction studies of biological and synthetic polymers.

    Energy Technology Data Exchange (ETDEWEB)

    Parrot, I. M. [Institut Laue-Langevin (ILL); Urban, Volker S [ORNL; Gardner, K. H. [DuPont Experimental Station; Forsyth, V. T. [Institut Laue Langevin and Keele University

    2005-04-01

    The fibrous state is a natural one for polymer molecules which tend to assume regular helical conformations rather than the globular structures characteristic of many proteins. Fibre diffraction therefore has broad application to the study of a wide range of biological and synthetic polymers. The purpose of this paper is to illustrate the general scope of the method and in particular to demonstrate the impact of a combined approach involving both X-ray and neutron diffraction methods. While the flux of modern X-ray synchrotron radiation sources allows high quality datasets to be recorded with good resolution within a very short space of time, neutron studies can provide unique information through the ability to locate hydrogen or deuterium atoms that are often difficult or impossible to locate using X-ray methods. Furthermore, neutron fibre diffraction methods can, through the ability to selectively label specific parts of a structure, be used to highlight novel aspects of polymer structure that can not be studied using X-rays. Two examples are given. The first describes X-ray and neutron diffraction studies of conformational transitions in DNA. The second describes structural studies of the synthetic high-performance polymer poly(p-phenylene terephthalamide) (PPTA), known commercially as Kevlar{reg_sign} or Twaron{reg_sign}.

  13. Combined X-ray and neutron fibre diffraction studies of biological and synthetic polymers

    Science.gov (United States)

    Parrot, I. M.; Urban, V.; Gardner, K. H.; Forsyth, V. T.

    2005-08-01

    The fibrous state is a natural one for polymer molecules which tend to assume regular helical conformations rather than the globular structures characteristic of many proteins. Fibre diffraction therefore has broad application to the study of a wide range of biological and synthetic polymers. The purpose of this paper is to illustrate the general scope of the method and in particular to demonstrate the impact of a combined approach involving both X-ray and neutron diffraction methods. While the flux of modern X-ray synchrotron radiation sources allows high quality datasets to be recorded with good resolution within a very short space of time, neutron studies can provide unique information through the ability to locate hydrogen or deuterium atoms that are often difficult or impossible to locate using X-ray methods. Furthermore, neutron fibre diffraction methods can, through the ability to selectively label specific parts of a structure, be used to highlight novel aspects of polymer structure that can not be studied using X-rays. Two examples are given. The first describes X-ray and neutron diffraction studies of conformational transitions in DNA. The second describes structural studies of the synthetic high-performance polymer poly(p-phenylene terephthalamide) (PPTA), known commercially as Kevlar® or Twaron®.

  14. Combined X-ray and neutron fibre diffraction studies of biological and synthetic polymers

    Energy Technology Data Exchange (ETDEWEB)

    Parrot, I.M. [Institut Laue Langevin, 6 Rue Jules Horowitz, 38042 Grenoble Cedex 9 (France); Institute of Science and Technology in Medicine, Keele University Medical School, Staffordshire ST4 7QB (United Kingdom); Urban, V. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6100 (United States); Gardner, K.H. [Department of Materials Science and Engineering University of Delaware, Newark, DE 19719 (United States); Forsyth, V.T. [Institut Laue Langevin, 6 Rue Jules Horowitz, 38042 Grenoble Cedex 9 (France) and Institute of Science and Technology in Medicine, Keele University Medical School, Staffordshire ST4 7QB (United Kingdom)]. E-mail: tforsyth@ill.fr

    2005-08-15

    The fibrous state is a natural one for polymer molecules which tend to assume regular helical conformations rather than the globular structures characteristic of many proteins. Fibre diffraction therefore has broad application to the study of a wide range of biological and synthetic polymers. The purpose of this paper is to illustrate the general scope of the method and in particular to demonstrate the impact of a combined approach involving both X-ray and neutron diffraction methods. While the flux of modern X-ray synchrotron radiation sources allows high quality datasets to be recorded with good resolution within a very short space of time, neutron studies can provide unique information through the ability to locate hydrogen or deuterium atoms that are often difficult or impossible to locate using X-ray methods. Furthermore, neutron fibre diffraction methods can, through the ability to selectively label specific parts of a structure, be used to highlight novel aspects of polymer structure that can not be studied using X-rays. Two examples are given. The first describes X-ray and neutron diffraction studies of conformational transitions in DNA. The second describes structural studies of the synthetic high-performance polymer poly(p-phenylene terephthalamide) (PPTA), known commercially as Kevlar[reg] or Twaron[reg].

  15. Radiochemical and thermal studies of the cation-exchanged forms of synthetic zeolite Linde sieve A

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, S P [Saugar Univ. (India). Dept. of Chemistry

    1976-02-01

    The compositions of the cobalt and silver-exchanged forms of synthetic zeolite Sieve A have been determined by radiochemical and TGA studies and correspond to Co/sub 6/A.19.8H/sub 2/O and Ag/sub 12/..cap alpha... 20H/sub 2/O respectively (A=Al/sub 12/Si/sub 12/O/sub 48//sup 12/-). Heating of these zeolites inhibits their capacity for cation exchange and water absorption. No evidence of occluded NaAlO/sub 2/ has been found.

  16. ESR studies of high-energy phosphorus-ion implanted synthetic diamond crystals

    Energy Technology Data Exchange (ETDEWEB)

    Isoya, J [University of Library and Information Science, Tsukuba, Ibaraki (Japan); Kanda, H; Morita, Y; Ohshima, T

    1997-03-01

    Phosphorus is among potential n-type dopants in diamond. High pressure synthetic diamond crystals of type IIa implanted with high energy (9-18 MeV) phosphorus ions have been studied by using electron spin resonance (ESR) technique. The intensity and the linewidth of the ESR signal attributed to the dangling bond of the amorphous phase varied with the implantation dose, suggesting the nature of the amorphization varies with the dose. The ESR signals of point defects have been observed in the low dose as-implanted crystals and in the high dose crystals annealed at high temperature and at high pressure. (author)

  17. Bacteriophage-based synthetic biology for the study of infectious diseases

    Science.gov (United States)

    Lu, Timothy K.

    2014-01-01

    Since their discovery, bacteriophages have contributed enormously to our understanding of molecular biology as model systems. Furthermore, bacteriophages have provided many tools that have advanced the fields of genetic engineering and synthetic biology. Here, we discuss bacteriophage-based technologies and their application to the study of infectious diseases. New strategies for engineering genomes have the potential to accelerate the design of novel phages as therapies, diagnostics, and tools. Though almost a century has elapsed since their discovery, bacteriophages continue to have a major impact on modern biological sciences, especially with the growth of multidrug-resistant bacteria and interest in the microbiome. PMID:24997401

  18. Selectivity in ligand binding to uranyl compounds: A synthetic, structural, thermodynamic and computational study

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, John [Univ. of California, Berkeley, CA (United States)

    2015-01-21

    The uranyl cation (UO₂²⁺) is the most abundant form of uranium on the planet. It is estimated that 4.5 billion tons of uranium in this form exist in sea water. The ability to bind and extract the uranyl cation from aqueous solution while separating it from other elements would provide a limitless source of nuclear fuel. A large body of research concerns the selective recognition and extraction of uranyl. A stable molecule, the cation has a linear O=U=O geometry. The short U-O bonds (1.78 Å) arise from the combination of uranium 5f/6d and oxygen 2p orbitals. Due to the oxygen moieties being multiply bonded, these sites were not thought to be basic enough for Lewis acidic coordination to be a viable approach to sequestration. The goal of this research is thus to broaden the coordination chemistry of the uranyl ion by studying new ligand systems via synthetic, structural, thermodynamic and computational methods. It is anticipated that this fundamental science will find use beyond actinide separation technologies in areas such as nuclear waste remediation and nuclear materials. The focus of this study is to synthesize uranyl complexes incorporating amidinate and guanidinate ligands. Both synthetic and computational methods are used to investigate novel equatorial ligand coordination and how this affects the basicity of the oxo ligands. Such an understanding will later apply to designing ligands incorporating functionalities that can bind uranyl both equatorially and axially for highly selective sequestration. Efficient and durable chromatography supports for lanthanide separation will be generated by (1) identifying robust peptoid-based ligands capable of binding different lanthanides with variable affinities, and (2) developing practical synthetic methods for the attachment of these ligands to Dowex ion exchange resins.

  19. Selectivity in ligand binding to uranyl compounds: A synthetic, structural, thermodynamic and computational study

    International Nuclear Information System (INIS)

    Arnold, John

    2015-01-01

    The uranyl cation (UO 2 2+ ) is the most abundant form of uranium on the planet. It is estimated that 4.5 billion tons of uranium in this form exist in sea water. The ability to bind and extract the uranyl cation from aqueous solution while separating it from other elements would provide a limitless source of nuclear fuel. A large body of research concerns the selective recognition and extraction of uranyl. A stable molecule, the cation has a linear O=U=O geometry. The short U-O bonds (1.78 Å) arise from the combination of uranium 5f/6d and oxygen 2p orbitals. Due to the oxygen moieties being multiply bonded, these sites were not thought to be basic enough for Lewis acidic coordination to be a viable approach to sequestration. The goal of this research is thus to broaden the coordination chemistry of the uranyl ion by studying new ligand systems via synthetic, structural, thermodynamic and computational methods. It is anticipated that this fundamental science will find use beyond actinide separation technologies in areas such as nuclear waste remediation and nuclear materials. The focus of this study is to synthesize uranyl complexes incorporating amidinate and guanidinate ligands. Both synthetic and computational methods are used to investigate novel equatorial ligand coordination and how this affects the basicity of the oxo ligands. Such an understanding will later apply to designing ligands incorporating functionalities that can bind uranyl both equatorially and axially for highly selective sequestration. Efficient and durable chromatography supports for lanthanide separation will be generated by (1) identifying robust peptoid-based ligands capable of binding different lanthanides with variable affinities, and (2) developing practical synthetic methods for the attachment of these ligands to Dowex ion exchange resins.

  20. Evaluation of synthetic hydrocarbons for mark-recapture studies on the red milkweed beetle.

    Science.gov (United States)

    Ginzel, Matthew D; Hanks, Lawrence M

    2002-05-01

    This study evaluates the potential for using blends of synthetic hydrocarbons in mark-recapture studies of insects. To test the durability of hydrocarbons, we applied a blend of five straight-chain hydrocarbons (C24, C21, C26. C28, C30) to detached elytra of the red milkweed beetle, Tetraopes tetrophthalmus (Forster) (Coleoptera: Cerambycidae), mounted the elytra on pins, and placed them in an exposed location outdoors. The amount of hydrocarbons on the elytra did not change over time, even after two months of exposure to sun and rain. Synthetic hydrocarbons applied to the elytra of living beetles did not significantly influence their longevity or mating success in a laboratory study. and the amounts of hydrocarbons did not change with age. The invariability of hydrocarbon ratios over time suggests that blends could provide a nearly infinite variety of ratios to mark individual insects uniquely and indelibly with a hydrocarbon "fingerprint." This technique offers a convenient, safe, and durable means of individually marking insects and may find application in field studies of larger bodied insects that are long-lived and sedentary.

  1. A randomised cross-over pharmacokinetic bioavailability study of synthetic versus kiwifruit-derived vitamin C.

    Science.gov (United States)

    Carr, Anitra C; Bozonet, Stephanie M; Vissers, Margreet C M

    2013-11-11

    Kiwifruit are a rich source of vitamin C and also contain numerous phytochemicals, such as flavonoids, which may influence the bioavailability of kiwifruit-derived vitamin C. The aim of this study was to compare the relative bioavailability of synthetic versus kiwifruit-derived vitamin C using a randomised cross-over pharmacokinetic study design. Nine non-smoking males (aged 18-35 years) received either a chewable tablet (200 mg vitamin C) or the equivalent dose from gold kiwifruit (Actinidia chinensis var. Sungold). Fasting blood and urine were collected half hourly to hourly over the eight hours following intervention. The ascorbate content of the plasma and urine was determined using HPLC with electrochemical detection. Plasma ascorbate levels increased from 0.5 h after the intervention (P = 0.008). No significant differences in the plasma time-concentration curves were observed between the two interventions (P = 0.645). An estimate of the total increase in plasma ascorbate indicated complete uptake of the ingested vitamin C tablet and kiwifruit-derived vitamin C. There was an increase in urinary ascorbate excretion, relative to urinary creatinine, from two hours post intervention (P vitamin C tablet and kiwifruit arms, respectively. Overall, our pharmacokinetic study has shown comparable relative bioavailability of kiwifruit-derived vitamin C and synthetic vitamin C.

  2. Molecular dynamics modeling the synthetic and biological polymers interactions pre-studied via docking

    Science.gov (United States)

    Tsvetkov, Vladimir B.; Serbin, Alexander V.

    2014-06-01

    In previous works we reported the design, synthesis and in vitro evaluations of synthetic anionic polymers modified by alicyclic pendant groups (hydrophobic anchors), as a novel class of inhibitors of the human immunodeficiency virus type 1 ( HIV-1) entry into human cells. Recently, these synthetic polymers interactions with key mediator of HIV-1 entry-fusion, the tri-helix core of the first heptad repeat regions [ HR1]3 of viral envelope protein gp41, were pre-studied via docking in terms of newly formulated algorithm for stepwise approximation from fragments of polymeric backbone and side-group models toward real polymeric chains. In the present article the docking results were verified under molecular dynamics ( MD) modeling. In contrast with limited capabilities of the docking, the MD allowed of using much more large models of the polymeric ligands, considering flexibility of both ligand and target simultaneously. Among the synthesized polymers the dinorbornen anchors containing alternating copolymers of maleic acid were selected as the most representative ligands (possessing the top anti-HIV activity in vitro in correlation with the highest binding energy in the docking). To verify the probability of binding of the polymers with the [HR1]3 in the sites defined via docking, various starting positions of polymer chains were tried. The MD simulations confirmed the main docking-predicted priority for binding sites, and possibilities for axial and belting modes of the ligands-target interactions. Some newly MD-discovered aspects of the ligand's backbone and anchor units dynamic cooperation in binding the viral target clarify mechanisms of the synthetic polymers anti-HIV activity and drug resistance prevention.

  3. Fatigue studies in compensated bulk lead zirconate titanate

    International Nuclear Information System (INIS)

    Verdier, Cyril; Morrison, Finlay D.; Lupascu, Doru C.; Scott, James F.

    2005-01-01

    Impedance analysis studies were carried out on compensated bulk lead zirconate titanate samples. Fatigue is concomitant with the onset of dielectric loss. This is shown to be dominantly due to an irreversibly modified near-surface layer that can be polished off. The highly compensated nature of these samples minimizes the role of oxygen vacancies

  4. Learning through Leading: A Self-Study in District Administration

    Science.gov (United States)

    Collins, Christina

    2016-01-01

    There is little research in the area of understanding educational leaders' psychological processes. This lack of understanding leaves educational leaders to develop their own sense-making practices while in the complex and stressful act of leading. This self-study, conducted over more than half a school year in 2014-2015, was my own effort to do…

  5. Process optimization and mechanistic studies of lead (II): Aspergillus ...

    African Journals Online (AJOL)

    The lead (II) accumulation potential of various biosorbent had been widely studied in the last few years, but an outstanding Pb(II) accumulating biomass still seems crucial for bringing the process to a successful application stage. This investigation describes the use of non-living biomass of Aspergillus caespitosus for ...

  6. A scenario study of seismically induced landsliding in Seattle using broadband synthetic seismograms

    Science.gov (United States)

    Allstadt, Kate E.; Vidale, John E.; Frankel, Arthur D.

    2013-01-01

    We demonstrate the value of utilizing broadband synthetic seismograms to assess regional seismically induced landslide hazard. Focusing on a case study of an Mw 7.0 Seattle fault earthquake in Seattle, Washington, we computed broadband synthetic seismograms that account for rupture directivity and 3D basin amplification. We then adjusted the computed motions on a fine grid for 1D amplifications based on the site response of typical geologic profiles in Seattle and used these time‐series ground motions to trigger shallow landsliding using the Newmark method. The inclusion of these effects was critical in determining the extent of landsliding triggered. We found that for inertially triggered slope failures modeled by the Newmark method, the ground motions used to simulate landsliding must have broadband frequency content in order to capture the full slope displacement. We applied commonly used simpler methods based on ground‐motion prediction equations for the same scenario and found that they predicted far fewer landslides if only the mean values were used, but far more at the maximum range of the uncertainties, highlighting the danger of using just the mean values for such methods. Our results indicate that landsliding triggered by a large Seattle fault earthquake will be extensive and potentially devastating, causing direct losses and impeding recovery. The high impact of landsliding predicted by this simulation shows that this secondary effect of earthquakes should be studied with as much vigor as other earthquake effects.

  7. Lead (Pb) isotopic fingerprinting and its applications in lead pollution studies in China: a review.

    Science.gov (United States)

    Cheng, Hefa; Hu, Yuanan

    2010-05-01

    As the most widely scattered toxic metal in the world, the sources of lead (Pb) observed in contamination investigation are often difficult to identify. This review presents an overview of the principles, analysis, and applications of Pb isotopic fingerprinting in tracing the origins and transport pathways of Pb in the environment. It also summarizes the history and current status of lead pollution in China, and illustrates the power of Pb isotopic fingerprinting with examples of its recent applications in investigating the effectiveness of leaded gasoline phase-out on atmospheric lead pollution, and the sources of Pb found in various environmental media (plants, sediments, and aquatic organisms) in China. The limitations of Pb isotopic fingerprinting technique are discussed and a perspective on its development is also presented. Further methodological developments and more widespread instrument availability are expected to make isotopic fingerprinting one of the key tools in lead pollution investigation. Copyright 2009 Elsevier Ltd. All rights reserved.

  8. Neuropsychological studies in children with elevated tooth-lead concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Winneke, G.; Hrdina, K.G.; Brockhaus, A.

    1982-12-01

    Tooth-lead concentrations (PbT) provide retrospective information about longterm, cumulative childhood lead-intake. From a basic sample of 458 school age children from the city of Duisburg (FRG), whose lead-concentrations in shed incisor teeth had been measured (anti x = 4.6 ppm; range: 1.4 - 12.7 ppm), two extreme groups of 26 children each (mean age: 8,5 years) with low (anti x = 2.4 ppm) and elevated (anti x = 9.2 ppm) PbT were selected. After pair-matching both groups for age, sex, and father's occupational status, these children were tested under double-blind precautions for intellectual performance (German WISC), for perceptual-motor integration (Goettinger Formreproduktionstest = GFT, Diagnostikum fuer Cerebralschaedigung = DCS, Benton-Test), and for gross motor-coordination (Koerper-Koordinationstest fuer Kinder = KTK). Significant (P < 0.05) inferiority of the lead-children was found in two tests of perceptual-motor integration (increased GFT-errors; lower success rate for DCS). In addition a near significant (P < 0.1) reduction of 5-7 IQ-points was determined in these children. Although this pilot study has provided some evidence for an association between childhood lead-exposure and neuropsychological impairment, this association cannot yet be considered proven, because the observed effects were discrete and statistically confirmed only in part, and because there was a slight prevalence of perinatal risk factors in the lead group. Further research to clarify the issue is necessary.

  9. Neuropsychological studies in children with elevated tooth-lead concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Winneke, G; Hrdina, K G; Brockhaus, A

    1982-12-01

    Tooth-lead concentrations (PbT) provide retrospective information about longterm, cumulative childhood lead-intake. From a basic sample of 458 school age children from the city of Duisburg (FRG), whose lead-concentrations in shed incisor teeth had been measured (anti x = 4.6 ppm; range: 1.4 - 12.7 ppm), two extreme groups of 26 children each (mean age: 8,5 years) with low (anti x = 2.4 ppm) and elevated (anti x = 9.2 ppm) PbT were selected. After pair-matching both groups for age, sex, and father's occupational status, these children were tested under double-blind precautions for intellectual performance (German WISC), for perceptual-motor integration (Goettinger Formreproduktionstest = GFT, Diagnostikum fuer Cerebralschaedigung = DCS, Benton-Test), and for gross motor-coordination (Koerper-Koordinationstest fuer Kinder = KTK). Significant (P < 0.05) inferiority of the lead-children was found in two tests of perceptual-motor integration (increased GFT-errors; lower success rate for DCS). In addition a near significant (P < 0.1) reduction of 5-7 IQ-points was determined in these children. Although this pilot study has provided some evidence for an association between childhood lead-exposure and neuropsychological impairment, this association cannot yet be considered proven, because the observed effects were discrete and statistically confirmed only in part, and because there was a slight prevalence of perinatal risk factors in the lead group. Further research to clarify the issue is necessary.

  10. Lead theft--a study of the "uniqueness" of lead from church roofs.

    Science.gov (United States)

    Bond, John W; Hainsworth, Sarah V; Lau, Tien L

    2013-07-01

    In the United Kingdom, theft of lead is common, particularly from churches and other public buildings with lead roofs. To assess the potential to distinguish lead from different sources, 41 samples of lead from 24 church roofs in Northamptonshire, U.K, have been analyzed for relative abundance of trace elements and isotopes of lead using X-ray fluorescence (XRF) and inductively coupled plasma mass spectrometry, respectively. XRF revealed the overall presence of 12 trace elements with the four most abundant, calcium, phosphorus, silicon, and sulfur, showing a large weight percentage standard error of the mean of all samples suggesting variation in the weight percentage of these elements between different church roofs. Multiple samples from the same roofs, but different lead sheets, showed much lower weight percentage standard errors of the mean suggesting similar trace element concentrations. Lead isotope ratios were similar for all samples. Factors likely to affect the occurrence of these trace elements are discussed. © 2013 American Academy of Forensic Sciences.

  11. Synthetic Cannabinoids.

    Science.gov (United States)

    Mills, Brooke; Yepes, Andres; Nugent, Kenneth

    2015-07-01

    Synthetic cannabinoids (SCBs), also known under the brand names of "Spice," "K2," "herbal incense," "Cloud 9," "Mojo" and many others, are becoming a large public health concern due not only to their increasing use but also to their unpredictable toxicity and abuse potential. There are many types of SCBs, each having a unique binding affinity for cannabinoid receptors. Although both Δ-tetrahydrocannabinol (THC) and SCBs stimulate the same receptors, cannabinoid receptor 1 (CB1) and cannabinoid receptor 2 (CB2), studies have shown that SCBs are associated with higher rates of toxicity and hospital admissions than is natural cannabis. This is likely due to SCBs being direct agonists of the cannabinoid receptors, whereas THC is a partial agonist. Furthermore, the different chemical structures of SCBs found in Spice or K2 may interact in unpredictable ways to elicit previously unknown, and the commercial products may have unknown contaminants. The largest group of users is men in their 20s who participate in polydrug use. The most common reported toxicities with SCB use based on studies using Texas Poison Control records are tachycardia, agitation and irritability, drowsiness, hallucinations, delusions, hypertension, nausea, confusion, dizziness, vertigo and chest pain. Acute kidney injury has also been strongly associated with SCB use. Treatment mostly involves symptom management and supportive care. More research is needed to identify which contaminants are typically found in synthetic marijuana and to understand the interactions between different SBCs to better predict adverse health outcomes.

  12. Synthetic hydrogeological study on Beishan preselected area for high-level radioactive waste repository in China

    International Nuclear Information System (INIS)

    Guo Yonghai; Su Rui; Ji Ruili; Wang Hailong; Liu Shufen; Zong Zihua; Dong Jiannan; Zhang Ming

    2014-01-01

    On the basis of large scale field hydrogeological investigation, synthetic hydrogeological studies related to groundwater system characteristics, permeability of rock bodies, groundwater dynamic, hydrogeochemistry, isotopic hydrology, CFC's of groundwater and groundwater flow field simulation were carried out for Beishan area, Gansu province. According to analysis on a large amount of hydrogeological data, the characteristics of groundwater circulation, groundwater hydrodynamics and hydrgeochemistry were described and the suitability of Beishan area as the potential area of high-level radioactive waste disposal was evaluated in the paper. Through this study, the hydrogeological study and evaluation methods in the siting of China's high level radioactive waste repository were set up. Furthermore, the important hydrogeological scientific evidence was provided for optimal site filtration of China's high-level radioactive waste repository in Beishan area. (authors)

  13. Lead isotope ratios as a tracer for lead contamination sources: A lake Andong case study

    Directory of Open Access Journals (Sweden)

    Kim Y. H

    2013-04-01

    Full Text Available The objective of this study was to evaluate stable Pb isotope signatures as a tracer for Pb contamination in Lake Andong. For Pb isotope analysis, we collected water and sediment from Lake Andong, particles in the air, soils, and stream water, mine tailings, sludge and wastewater from zinc smelting around lake Andong watershed. The results showed that Pb isotope ratios (206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb for zinc concentrate were 18.809 ± 0.322, 15.650 ± 0.062, and 38.728 ± 0.421, respectively. In wastewater, isotopic ratio values (206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb were 17.363 ± 0.133, 15.550 ± 0.025, and 37.217 ± 0.092, respectively. Additionally, isotopic ratio values (206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb for sludge were 17.515 ± 0.155, 15.537 ± 0.018, and 37.357 ± 0.173, respectively. These values were similar to those in zinc and lead concentrate originated from Canada and South America. In contrast, Pb isotope ratios of soil, tailings and sediment from Lake Andong were similar to those of Korean ore. Atmospheric particles showed different patterns of Pb isotope ratios from sediments, soils, and zinc smelting and this needs further investigation in order to identify atmospheric Pb sources.

  14. Lead (Pb) isotopic fingerprinting and its applications in lead pollution studies in China: A review

    International Nuclear Information System (INIS)

    Cheng Hefa; Hu Yuanan

    2010-01-01

    As the most widely scattered toxic metal in the world, the sources of lead (Pb) observed in contamination investigation are often difficult to identify. This review presents an overview of the principles, analysis, and applications of Pb isotopic fingerprinting in tracing the origins and transport pathways of Pb in the environment. It also summarizes the history and current status of lead pollution in China, and illustrates the power of Pb isotopic fingerprinting with examples of its recent applications in investigating the effectiveness of leaded gasoline phase-out on atmospheric lead pollution, and the sources of Pb found in various environmental media (plants, sediments, and aquatic organisms) in China. The limitations of Pb isotopic fingerprinting technique are discussed and a perspective on its development is also presented. Further methodological developments and more widespread instrument availability are expected to make isotopic fingerprinting one of the key tools in lead pollution investigation. - This review presents an overview of the principles, applications, and limitations of Pb isotopic fingerprinting in lead pollution investigation, and provides a perspective on its future development.

  15. Continuing Studies on Lead/Scintillating Fibres Calorimetry (LFC)

    CERN Multimedia

    2002-01-01

    Starting from the results obtained in the framework of the LAA Project~2B, we propose a continuation of the R&D on lead/scintillating fibres calorimetry (``spaghetti calorimetry''), including further tests on the old calorimeter prototypes and the construction and testing of new prototypes. The main results we pursue concern the performances of a projective calorimeter built with new, cheaper, techniques and the radiation hardness of the scintillating fibres, the optimization of a preshower detector system is also studied.

  16. Leading and leadership: Reflections on a case study.

    OpenAIRE

    Joyce, Pauline

    2010-01-01

    Aim: The aim of this case study was to explore if observing leaders in the context of their day-to-day work can provide an insight into how they lead in particular circumstances. Background: The study was carried out in small organisation which was set up five years ago. Methods: A case study methodology was used. Data was collected by field notes of non-participant and participant observations. Follow-up interviews were transcribed and analysed to contextualise the observations. A refl...

  17. Histomorphormetric studies on lactational lead intoxication in testes

    African Journals Online (AJOL)

    2018-02-28

    Feb 28, 2018 ... This research work was designed to investigate the impact of lactational lead exposure on ..... How did lead get into our gasoline:retrieved from www. ... Supplementation against Damage Caused by Lead in the Testes of Mice.

  18. Numerical study of nozzle design for the hybrid synthetic jet actuator

    Czech Academy of Sciences Publication Activity Database

    Hsu, S.-S.; Chou, Y.-J.; Trávníček, Zdeněk; Lin, C.-F.; Wang, A. B.; Yen, R.H.

    2015-01-01

    Roč. 232, August (2015), s. 172-182 ISSN 0924-4247 R&D Projects: GA ČR GA14-08888S Institutional support: RVO:61388998 Keywords : synthetic jet * hybrid synthetic jet * numerical simulation Subject RIV: JU - Aeronautics, Aerodynamics, Aircrafts Impact factor: 2.201, year: 2015 http://www.sciencedirect.com/science/article/pii/S0924424715300091

  19. NATO Advanced Study Institute on Synthetic Membranes : Science, Engineering and Applications

    CERN Document Server

    Lonsdale, H; Pinho, M

    1986-01-01

    The chapters in this book are based upon lectures given at the NATO Advanced Study Institute on Synthetic Membranes (June 26-July 8, 1983, Alcabideche, Portugal), which provided an integrated presentation of syn­ thetic membrane science and technology in three broad areas. Currently available membrane formation mechanisms are reviewed, as well as the manner in which synthesis conditions can be controlled to achieve desired membrane structures. Membrane performance in a specific separa­ tionprocess involves complex phenomena, the understanding of which re­ quires a multidisciplinary approach encompassing polymer chemistry, phys­ ical chemistry, and chemical engineering. Progress toward a global understanding of membrane phenomena is described in chapters on the principles of membrane transport. The chapters on membrane processes and applications highlight both established and emerging membrane processes, and elucidate their myriad applications. It is our hope that this book will be an enduring, comprehensi...

  20. Pneumatically Powered Drilling of Carbon Fibre Composites Using Synthetic Biodegradable Lubricating Oil: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Corydon M. J. Morrell

    2018-01-01

    Full Text Available Carbon fibre composites are a key component of aircraft structures because of their enhanced material properties such as favourable strength to weight ratios when compared to metal alloys. During the assembly process of an aircraft, carbon fibre components are joined to other structures using rivets, bolts, and fasteners, and as part of the joining process, the components will need to be machined or drilled. Unlike metal alloys, composites are sensitive to heat and are vulnerable to internal structural damage from machining tools. They are also susceptible to a reduction in strength when fibres are exposed to moisture. In the machining process, carbon fibre composites may be drilled using oils to lubricate carbide machining tools. In this study, a description of the experimental apparatus is provided along with an investigation to determine the influence synthetic biodegradable lubricating oil has on drill rotational speed, drilling load, and drilling temperature when using a pneumatic drill to machine carbon fibre composite material.

  1. Generation of synthetic influent data for performing (micro) pollutant wastewater treatment modelling studies

    DEFF Research Database (Denmark)

    Snip, L. J. P.; Aymerich, I.; Flores-Alsina, X.

    2015-01-01

    The use of Activated Sludge Models (ASM) (Henze et al., 2000) is constantly growing and both industry and academia are increasingly applying these tools when performing wastewater treatment plant (WWTP) engineering studies. Besides describing the behaviour of traditional pollutants such as organic...... carbon (C), nitrogen(N) and phosphorus(P), ASM models have been successfully upgraded to predict the fate of different types of micro-pollutants (Benedetti et al., 2013). Indeed, the potential adverse effects of micro-pollutants in aquatic environments have been an object of intensive research during...... (Gernaey et al., 2011). This is an important point since realistic data representing the influent wastewater dynamics are crucial to accomplish any WWTP modelling project (Rieger et al., 2012). For this reason, model-based influent generators/synthetic data are an alternative that has recently gained...

  2. Modeling induced polarization effects in helicopter time domain electromagnetic data: Synthetic case studies

    DEFF Research Database (Denmark)

    Viezzoli, Andrea; Kaminskiy, Vladislav; Fiandaca, Gianluca

    2017-01-01

    constrained multiparametric inversion was evaluated, including recovery of chargeability distributions from shallow and deep targets based on analysis of induced polarization (IP) effects, simulated in airborne TDEM data. Different scenarios were studied, including chargeable targets associated...... processing and the effect of constraints, and a priori information. We have used a 1D layered earth model approximation and lateral constraints. Synthetic simulations were performed for several models and the corresponding Cole-Cole parameters. The possibility to recover these models by means of laterally...... the airborne electromagnetic is most sensitive (e.g., approximately 1 ms), it is possible to recover deep chargeable targets (to depths more than 130 m) in association with high electrical conductivity and in resistive environments. Furthermore, it was found that the recovery of a deep conductor, masked...

  3. Studies of alkaline mediated phosphate migration in synthetic phosphoethanolamine l-glycero-d-manno-heptoside derivatives

    International Nuclear Information System (INIS)

    Stewart, A.; Martin, A.; Richards, J.C.; Bernlind, C.; Oscarson, S.; Schweda, E.K.H.

    1998-01-01

    Synthetic 2-, 3-, 4- and 6-monophosphate derivatives of methyl α-d-mannopyranosides, the 4-, 6- and 7-monophosphate derivatives of methyl l-glycero-α-d-manno-heptopyranosides and the corresponding phosphoethanolamine derivatives and a 6,7-cyclic phosphate analogue of methyl l-glycero-α-d-manno-heptopyranoside were used to study phosphate migration and hydrolysis when subjected to strong alkaline conditions (4 M KOH, 120 C, 18 h). The resulting products were analyzed by 1 H NMR spectroscopy and electrospray mass spectrometry. It was found that phosphate substituents were stable under these conditions and neither migration nor hydrolysis was observed except for the heptose 7-phosphate, which gave a substantial amount of phosphate hydrolysis. In phosphoethanolamine-substituted compounds migration to adjacent positions with concomitant loss of ethanolamine was found together with hydrolysis. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  4. Synthetical bone-like and biological hydroxyapatites: a comparative study of crystal structure and morphology

    Energy Technology Data Exchange (ETDEWEB)

    Markovic, Smilja; Veselinovic, Ljiljana; Lukic, Miodrag J; Ignjatovic, Nenad; Uskokovic, Dragan [Institute of Technical Sciences of the Serbian Academy of Sciences and Arts, Knez Mihailova 35/IV, 11001 Belgrade (Serbia); Karanovic, Ljiljana [Laboratory for Crystallography, Faculty of Mining and Geology, University of Belgrade, Dusina 7, 11000 Belgrade (Serbia); Bracko, Ines, E-mail: dragan.uskokovic@itn.sanu.ac.rs [Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia)

    2011-08-15

    Phase composition, crystal structure and morphology of biological hydroxyapatite (BHAp) extracted from human mandible bone, and carbonated hydroxyapatite (CHAp), synthesized by the chemical precipitation method, were studied by x-ray powder diffraction (XRD), Fourier transform infrared (FTIR) and Raman (R) spectroscopy techniques, combined with transmission electron microscopy (TEM). Structural and microstructural parameters were determined through Rietveld refinement of recorded XRD data, performed using the FullProf computing program, and TEM. Microstructural analysis shows anisotropic extension along the [0 0 l] crystallographic direction (i.e. elongated crystallites shape) of both investigated samples. The average crystallite sizes of 10 and 8 nm were estimated for BHAp and CHAp, respectively. The FTIR and R spectroscopy studies show that carbonate ions substitute both phosphate and hydroxyl ions in the crystal structure of BHAp as well as in CHAp, indicating that both of them are mixed AB-type of CHAp. The thermal behaviour and carbonate content were analysed using thermogravimetric and differential thermal analysis. The carbonate content of about 1 wt.% and phase transition, at near 790 {sup 0}C, from HAp to {beta}-tricalcium phosphate were determined in both samples. The quality of synthesized CHAp powder, particularly, the particle size distribution and uniformity of morphology, was analysed by a particle size analyser based on laser diffraction and field emission scanning electron microscopy, respectively. These data were used to discuss similarity between natural and synthetic CHAp. Good correlation between the unit cell parameters, average crystallite size, morphology, carbonate content and crystallographic positions of carbonate ions in natural and synthetic HAp samples was found.

  5. Impact of different synthetic bone fillers on healing of extraction sockets: an experimental study in dogs.

    Science.gov (United States)

    Hong, Ji-Youn; Lee, Jung-Seok; Pang, Eun-Kyoung; Jung, Ui-Won; Choi, Seong-Ho; Kim, Chong-Kwan

    2014-02-01

    The objective of this study was to elucidate the socket healing process and biodegradation of incorporating synthetic bone fillers followed by grafting of the fresh extraction socket. Third premolars in four quadrants of eight beagle dogs were extracted and randomly treated with either one of hydroxyapatite (HA), biphasic calcium phosphate (BCP), β-tricalcium phosphate (β-TCP), or no graft (C). Histologic observations and histomorphometric analysis at three zones (apical, middle, and coronal) of the socket were performed. Socket area (S) and the proportions of newly formed bone (%NB), residual biomaterials (%RB), and fibrovascular connective tissue (%FCT) at 2, 4, and 8 weeks were measured. The numbers of osteoclast-like multinucleated cells (No.OC) were also determined at the three zones. %NB was significantly higher in control group compared with the grafted groups at all healing periods. %NB of HA and BCP increased with time, whereas %RB showed different patterns that decreased in BCP, unlike the minimal change observed in HA. %NB of β-TCP showed smallest portion compared with other grafted groups at 2 and 4 weeks, however, significantly increased at 8 weeks. %RB of β-TCP was less than HA and BCP at all healing periods. Numbers of multinucleated cells were greater in BCP and β-TCP, followed by HA and smallest in control group. Within the limit of this study, bone formation of the extraction socket was delayed in the sockets grafted with synthetic bone fillers and showed different healing process according to the biodegradation patterns. © 2012 John Wiley & Sons A/S.

  6. Synthetical bone-like and biological hydroxyapatites: a comparative study of crystal structure and morphology

    International Nuclear Information System (INIS)

    Markovic, Smilja; Veselinovic, Ljiljana; Lukic, Miodrag J; Ignjatovic, Nenad; Uskokovic, Dragan; Karanovic, Ljiljana; Bracko, Ines

    2011-01-01

    Phase composition, crystal structure and morphology of biological hydroxyapatite (BHAp) extracted from human mandible bone, and carbonated hydroxyapatite (CHAp), synthesized by the chemical precipitation method, were studied by x-ray powder diffraction (XRD), Fourier transform infrared (FTIR) and Raman (R) spectroscopy techniques, combined with transmission electron microscopy (TEM). Structural and microstructural parameters were determined through Rietveld refinement of recorded XRD data, performed using the FullProf computing program, and TEM. Microstructural analysis shows anisotropic extension along the [0 0 l] crystallographic direction (i.e. elongated crystallites shape) of both investigated samples. The average crystallite sizes of 10 and 8 nm were estimated for BHAp and CHAp, respectively. The FTIR and R spectroscopy studies show that carbonate ions substitute both phosphate and hydroxyl ions in the crystal structure of BHAp as well as in CHAp, indicating that both of them are mixed AB-type of CHAp. The thermal behaviour and carbonate content were analysed using thermogravimetric and differential thermal analysis. The carbonate content of about 1 wt.% and phase transition, at near 790 0 C, from HAp to β-tricalcium phosphate were determined in both samples. The quality of synthesized CHAp powder, particularly, the particle size distribution and uniformity of morphology, was analysed by a particle size analyser based on laser diffraction and field emission scanning electron microscopy, respectively. These data were used to discuss similarity between natural and synthetic CHAp. Good correlation between the unit cell parameters, average crystallite size, morphology, carbonate content and crystallographic positions of carbonate ions in natural and synthetic HAp samples was found.

  7. Association of tibia lead and blood lead with end-stage renal disease: A pilot study of African-Americans

    International Nuclear Information System (INIS)

    Muntner, Paul; Menke, Andy; Batuman, Vecihi; Rabito, Felicia A.; He Jiang; Todd, Andrew C.

    2007-01-01

    The association between body lead burden and kidney disease remains controversial. Fifty-five African-American end-stage renal disease (ESRD) cases and 53 age- and sex-matched African-American controls without known renal disease were recruited from Tulane University-affiliated dialysis clinics and out-patient clinics, respectively. Blood lead was measured via atomic absorption spectrophotometry and tibia lead (a measure of body lead) was measured via 109 Cd-based K shell X-ray fluorescence. Median blood lead levels were significantly higher among ESRD cases (6 μg/dL) compared to their control counterparts (3 μg/dL; P<0.001). Although no participants had overt lead poisoning (blood lead ≥25 μg/dL), seven cases but no controls had blood lead levels above 10 μg/dL (P=0.006). The median tibia lead level was 17 micrograms of lead per gram of bone mineral (μg/g) and 13 μg/g among ESRD cases and their control counterparts, respectively (P=0.134). Four ESRD cases (7%), but no controls, had a tibia lead level above 40 μg/g (P=0.115) while a similar proportion of cases and controls had tibia lead between 20 and 39 μg/g (33% and 32%, respectively; P=0.726). After adjustment for potential confounders, the odds ratios of ESRD associated with a tibia lead ≥20 μg/g and each four-fold higher tibia lead (e.g., 5-20 μg/g) were 1.55 (95% CI: 0.55, 4.41) and 1.88 (95% CI: 0.53, 6.68), respectively. These findings support the need for prospective cohort studies of body lead burden and renal disease progression

  8. XAFS studies of nickel-doped lead telluride

    International Nuclear Information System (INIS)

    Radisavljevic, Ivana; Novakovic, Nikola; Ivanovic, Nenad; Romcevic, Nebojsa; Manasijevic, Miodrag; Mahnke, Heinz-Eberhard

    2009-01-01

    The problem of impurities and defect states in lead telluride-based semiconductors is of crucial importance for their practical applications. X-ray absorption fine structure (XAFS) techniques are capable to address some of the key issues regarding impurities position, their valent state, as well as the local structural changes of the host lattice in the immediate surrounding of the impurity atoms. In this paper we present the results of the Ni K-absorption edge XAFS studies of Ni-doped PbTe at different temperatures. Analysis of near edge and extended XAFS regions of the measured spectra provided information about exact local environment and lattice ordering around Ni atoms.

  9. Stable lead isotopes and lake sediments. A useful combination for the study of atmospheric lead pollution history

    Energy Technology Data Exchange (ETDEWEB)

    Renberg, I.; Braennvall, M.-L.; Bindler, R. [Department of Ecology and Environmental Science, Umea University, SE-901 87 Umea (Sweden); Emteryd, O. [Department of Forest Ecology, Swedish University of Agricultural Sciences, SE-901 83 Umea (Sweden)

    2002-06-20

    Analysis of stable lead isotopes and lead concentrations in lake-sediment deposits, not least in varved (annually-laminated) sediments, is a useful method to study lead pollution history. This paper presents details from a study of 31 lakes in Sweden. Using a strong acid digestion of sediment samples and ICP-MS analyses, we have found that Swedish lake sediments have a high natural (pre-pollution) 206[Pb]/207[Pb] ratio (mean 1.52{+-}0.18, range 1.28-2.01, n=31 lakes). In contrast, atmospheric lead pollution derived from metal smelting processes, coal burning and from alkyl-lead added to petrol has a lower ratio (<1.2). Consequently, when pollution lead deposition began approximately 3500 years ago, the lead isotope ratio of the sediments started to decline, and in modern sediments it is typically <1.2. Using the isotope and concentration values and a mixing model, the relative contribution of pollution and natural lead in sediment samples can be calculated. The pollution lead records of the Swedish lake sediments show a consistent picture of the atmospheric lead pollution history. Some noticeable features are the Roman peak, the large and permanent Medieval increase, peaks at approximately 1200 and 1530 ad, the rapid increase after World War II, the peak in the 1970s, and the large modern decline.

  10. Effect of lead pollution control on environmental and childhood blood lead level in Nantong, China: an interventional study.

    Science.gov (United States)

    Chen, Kai; Huang, Lei; Yan, Beizhan; Li, Hongbo; Sun, Hong; Bi, Jun

    2014-11-04

    Children's blood lead levels and prevalence of lead poisoning in China are significantly higher than in developed countries, though a substantial decrease has been observed. Since 2011, strict lead control policies in lead-related industries have been implemented in China, but the success of these policies is unknown. In this study, we collected environmental samples, questionnaire data, and blood samples from 106 children from 1 to 14 years old, before and after implementation of lead-usage control policy in wire rope factories by local government in Zhuhang, Nantong in 2012. Results showed that, one year after the lead control, lead concentrations sharply decreased in both environmental and biological samples with a decrease of 0.43 μg/m3 (-84.3%) in ambient air samples, 0.22 mg/kg (-36.1%) in vegetable samples, 441.1 mg/kg (-43.7%) in dust samples, and 6.24 μg/dL (-51.5%) in childhood blood lead levels (BLL). This study demonstrates the success of lead control policies in promoting the prevention and control of childhood lead poisoning in Nantong, China.

  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. System design study of small lead-bismuth cooled reactor

    International Nuclear Information System (INIS)

    Chikazawa, Yoshitaka; Hori, Toru; Konomura, Mamoru

    2003-07-01

    In phase II of the feasibility study of JNC, we will make a concept of a dispersion power source reactor with various requirements, such as economical competitiveness and safety. In the study of a small lead-bismuth cooled reactor, a concept whose features are long life core, inherent safety, natural convection of cooling system and steam generators in the reactor vessel has been designed since 2000. The investigations which have been done in 2002 are shown as follows; Safety analysis of UTOP considering uncertainty of reactivity. Possibility of reduction of number of control rods. Estimation of construction cost. Transient analyses of UTOP have been done in considering uncertainty of reactivity in order to show the inherent safety in the probabilistic method. And the inherent safety in UTOP is realized under the condition of considering uncertainty. Transient analyses of UTOP with various numbers of control rods have been done and it is suggested that there is possibility of reduction of the number of control rods considering accident managements. The method of cost estimation is a little modified. The cost of reactor vessel is estimated from that of medium sized lead-bismuth cooled reactor and the estimation of a purity control system is by coolant volume flow rate. The construction cost is estimated 850,000yen/kWe. (author)

  13. A comparative thermoluminescence and electron spin resonance study of synthetic carbonated A-type hydroxyapatite

    International Nuclear Information System (INIS)

    Oliveira, L.C.; Rossi, A.M.; Baffa, O.

    2012-01-01

    Intensity of the 150 °C thermoluminescence peak of beta-irradiated carbonated synthetic A-type hydroxyapatite is approximately 12 times higher than that of the noncarbonated material. Deconvolution of the glow curve showed that this peak is a result of a trap distribution. An attempt was made to relate this thermoluminescence peak enhanced by carbonation with the ESR signal of the CO 2 − radical in natural or synthetic hydroxyapatite. - Highlights: ► Synthetic hydroxyapatite was carbonated with CO 2 . ► TL enhanced by 12 times in carbonated synthetic A-type hydroxyapatite. ► EPR and TL were performed to find out a relation between CO 2 − center and the TL. ► No direct relation was found between the CO 2 − center and TL enhancement.

  14. Study of the immunological relatedness of goldfish MSH in an RIA for synthetic mammalian α MSH

    International Nuclear Information System (INIS)

    Follenius, Ernest; Schmitt, Gabrielle; Meunier, Annie

    1980-01-01

    α MSH from the neuro-intermediate lobe of the pituitary gland of the goldfish displays a competitive behaviour in an RIA for synthetic α MSH. The inhibition curves from neuro-intermediate homogenates parallel the standard curve (P [fr

  15. Synthetic strategies for plant signalling studies: molecular toolbox and orthogonal platforms

    KAUST Repository

    Braguy, Justine; Zurbriggen, Matias D.

    2016-01-01

    of involved functional and regulatory mechanisms. The implementation of synthetic biology approaches is revolutionizing experimental biology in prokaryotes, yeasts and animal systems and can likewise contribute to a new era in plant biology. This review gives

  16. Fortification of yogurts with different antioxidant preservatives: A comparative study between natural and synthetic additives.

    Science.gov (United States)

    Caleja, Cristina; Barros, Lillian; Antonio, Amilcar L; Carocho, Márcio; Oliveira, M Beatriz P P; Ferreira, Isabel C F R

    2016-11-01

    Consumers demand more and more so-called "natural" products and, therefore, the aim of this work was to compare the effects of natural versus synthetic antioxidant preservatives in yogurts. Matricaria recutita L. (chamomile) and Foeniculum vulgare Mill. (fennel) decoctions were tested as natural additives, while potassium sorbate (E202) was used as a synthetic additive. The fortification of yogurts with natural and synthetic antioxidants did not cause significant changes in the yoghurt pH and nutritional value, in comparison with control samples (yogurt without any additive). However, the fortified yogurts showed higher antioxidant activity, mainly the yogurts with natural additives (and among these, the ones with chamomile decoction). Overall, it can be concluded that plant decoctions can be used to develop novel yogurts, by replacing synthetic preservatives and improving the antioxidant properties of the final product, without changing the nutritional profile. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Study of the Properties of Bentonites for their use in Clay Geo synthetic Barriers

    International Nuclear Information System (INIS)

    Leiro Lopez, A.; Mateo Sanz, B.; Garcia Cidoncha, H.; Blanco Fernandez, M.

    2014-01-01

    Bentonites used for the production of clay geo synthetic barriers need to meet some properties so that they can be a waterproofing system. among the bentonites used in industry, sodium bentonite has the lowest permeability due to its high water absorption capacity in the inter-laminar space, causing it to swell and form a barrier to water flow. this paper provides the study of the properties of four bentonite to evaluate their quality the study of the properties of four bentonite to evaluate their quality. For this study, the main properties have been tested: water absorption, swelling index, fluid loss, cation exchange capacity and montmorillonite content. In order to optimize the procedure for the characterization of bentonites, correlations between different tests have been done, to identify the most suitable ones. Finally, a compatibility test has been carried out to study the performance of bentonites in water containing a high amount of sales, because in this case, an ion exchange between the interlayer sodium ions of bentonite and cations dissolved in the water can take, resulting in a decrease swell of the bentonite. (Author)

  18. Ion and electron beam studies and applications of natural and synthetic diamonds

    International Nuclear Information System (INIS)

    Sellschop, J.P.F.; Connell, S.H.; Sideras-Haddad, E.; Stemmet, M.C.; Naidoo, S.; Bharuth-Ram, K.; Haricharun, H.

    1992-01-01

    'Nuclear' probes are shown to be powerful diagnostic analytical tools for the interrogation of diamond, whether natural or synthetic. The full sweep of such probes ranges from electrons to heavy ions, and spans energies over the keV to GeV range. Neutrons are singularly appropriate for the bulk trace element analysis of diamond, while charged particle (activation) analysis is appropriate for lighter element determination, and for surface and depth profiling specification. Energetic ions are effectively deployed for the study of the amorpisation and extrusion of diamond, and for ion implantation with the view to the production of devices in diamond. Resonant nuclear reactions are used effectively in establishing the 'macroscopic' distribution of dopants, while the used of pulsed ion beams in time dependent perturbed angular distribution studies gives information on 'microscopic' lattice location of impurities. Ion channeling in diamond sets near-theoretical parameterization of Lindhard channeling theory. Electron and positron channeling is interesting in its own right, and in the former case is shown to give rise to channeling radiation for few-MeV electron energies. At GeV electron energies, channeling is important as a powerful, polarized monochromatic photon source. Muons are an elegant tool in diamond studies, and the formation of muonium permits of (radiation damage-free) hydrogen-equivalent studies. Two relatively unused nuclear techniques, Moessbauer spectroscopy and Positron Annihilation, are shown to give unique information on diamond. Finally the use of diamond as a detector of radiation is indicated. (author)

  19. Dynamic Tunnel Usability Study: Format Recommendations for Synthetic Vision System Primary Flight Displays

    Science.gov (United States)

    Arthur, Jarvis J., III; Prinzel, Lawrence J., III; Kramer, Lynda J.; Bailey, Randall E.

    2006-01-01

    A usability study evaluating dynamic tunnel concepts has been completed under the Aviation Safety and Security Program, Synthetic Vision Systems Project. The usability study was conducted in the Visual Imaging Simulator for Transport Aircraft Systems (VISTAS) III simulator in the form of questionnaires and pilot-in-the-loop simulation sessions. Twelve commercial pilots participated in the study to determine their preferences via paired comparisons and subjective rankings regarding the color, line thickness and sensitivity of the dynamic tunnel. The results of the study showed that color was not significant in pilot preference paired comparisons or in pilot rankings. Line thickness was significant for both pilot preference paired comparisons and in pilot rankings. The preferred line/halo thickness combination was a line width of 3 pixels and a halo of 4 pixels. Finally, pilots were asked their preference for the current dynamic tunnel compared to a less sensitive dynamic tunnel. The current dynamic tunnel constantly gives feedback to the pilot with regard to path error while the less sensitive tunnel only changes as the path error approaches the edges of the tunnel. The tunnel sensitivity comparison results were not statistically significant.

  20. A neurological and biochemical study of early lead poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Ashby, J A.S.

    1980-05-01

    Motor nerve conduction velocities in 194 workers exposed to lead in a battery factory were compared with those of 94 age-matched controls. Changes in nerve conduction velocities of the 94 lead workers were found to have occurred. All mean maximum motor nerve conducting velocities measured were significantly lower in the lead-exposed group than in the control group. There was no statistically significant correlation to indicate that progressive slowing of nerve conduction was associated with increasing exposure to lead or with the commonly measured biochemical changes associated with disturbed haemopoiesis in lead exposure. Results suggest that the onset of nerve conduction changes occurs within two years.

  1. Microbial strategy for potential lead remediation: a review study.

    Science.gov (United States)

    Pan, Xiaohong; Chen, Zhi; Li, Lan; Rao, Wenhua; Xu, Zhangyan; Guan, Xiong

    2017-02-01

    The extensive exploitation and usage of lead compounds result in severe lead(II) pollution in water and soil environments, even in agricultural land, threatening the health of animals and humans via food chains. The recovery and remediation of lead(II) from water and soil environments have been intensively concerned in recent years. Compared with the traditional physic-chemistry treatment, microbial remediation strategy is a promising alternative to remediate lead(II)-contaminated environments due to its cost-effective and environmentally-friendly properties. Various microorganisms are capable of removing or immobilizing lead(II) from water and soil environments through bioaccumulation, precipitation or accelerated transformation of lead(II) into a very stable mineral, resulting in significant effects on lead(II) mobility and bioavailability. In the present review, we investigated a wide diversity of lead(II) bioremediation induced by different microbes and its multi-mechanisms. Moreover, we also discussed the progress and limitations, summarized the common rules of lead(II)-microbe interaction, and evaluated the environmental significance of microbes in lead biogeochemistry process. In addition, we further deliberated the feasibility and potential application of microbes in developing cost-effective, eco-friendly bioremediation or long-term management strategy for lead(II) contaminated repositories.

  2. Experimental study on the adsorptive-distillation for dehydration of ethanol-water mixture using natural and synthetic zeolites

    Science.gov (United States)

    Megawati, Wicaksono, D.; Abdullah, M. S.

    2017-03-01

    This research studied adsorptive-distillation (AD) for dehydration of ethanol-water mixture using natural and synthetic zeolites as adsorbent for ethanol purification. Especially, the effect of purification time is recorded and studied to evaluate performance of designed AD equipment. This AD was performed in a batch condition using boiling flask covered with heating mantle and it was maintained at 78°C temperature and 1 atm pressure. The initial ethanol volume was 300 mL with 93.8% v/v concentration. The synthetic zeolite type used was zeolite 3A. The flowed vapour was condensed using water as a cooling medium. Every 5 minutes of time duration the samples were collected until the vapour could not be condensed in that condition and then be analyzed its concentration using Gas-Chromatography. Experiment shows that the designed AD equipment could increase ethanol concentration at first 5 minutes with highest ethanol concentration achieved using synthetic zeolite (97.47% v/v). However, ethanol concentration from AD process using natural zeolite only reached 96.5% v/v. Thus, synthetic zeolite as adsorbent could pass azeotropic point, but natural zeolite fail. The ratio of adsorbed water per adsorbent for natural and synthetic zeolites are about 0.023 and 0.056 gwater/gads, respectively, at 50 minutes of time. Finally, synthetic zeolite (at 55 minutes the value of C/C0 is about 0.85 and the average outlet water concentration is 4.70 mole/L) as adsorbent for AD of ethanol water is better than natural zeolite (at 55 minutes the value of C/C0 is about 0.63 and the average outlet water concentration is 6.43 mole/L).

  3. Struvite Precipitation and Phosphorous Removal from Urine Synthetic Solution: Reaction Kinetic Study

    Directory of Open Access Journals (Sweden)

    Marwa Saied Shalaby

    2015-03-01

    Full Text Available Phosphorus, like oil, is a non-renewable resource that must be harvested from finite resources in the earth’s crust. An essential element for life, phosphorus is becoming increasingly scarce, contaminated, and difficult to extract. Struvite or magnesium ammonium phosphate (MgNH4PO4.6H2O is a white, crystalline phosphate mineral that can be used as a bio-available fertilizer. The main objective of this research is to indicate the most important operating parameters affecting struvite precipitation by means of chemical reaction kinetics. The present study explores struvite precipitation by chemical method under different starting molar ratios, pH and SSR. It is shown that an increase of starting Mg: PO4: NH4 with respect to magnesium (1.6:1:1 strongly influences the growth rate of struvite and so the efficiency of the phosphate removal. This was attributed to the effect of magnesium on the struvite solubility product and on the reached supersaturation Super Saturation Ratio at optimum starting molar ratio and pH. It was also shown, by using chemical precipitation method that the determined Super Saturation Ratio (SSR values of struvite, at 8, 8.5, 9, 9.5 and 10 are 1.314, 4.29, 8.89, 9.87 and 14.89 respectively are close to those presented in the literature for different origins of wastewater streams. The results show that SSR , pH, and starting molar ratio strongly influences the kinetics of precipitation and so phosphorous removal to reach 93% removal percent , 5.95 mg/lit as a minimum PO4 remained in solution, and 7.9 gm precipitated struvite from feed synthetic solution of 750 ml . The product was subjected to chemical analysis by means of EDIX-FTIR, SEM and XRD showing conformity with published literature. First-order kinetics was found to be sufficient to describe the rate data. The rates increased with increasing pH and so SSR and the apparent rate constants for the reaction were determined. © 2015 BCREC UNDIP. All rights reserved

  4. The Effect of Loading Rate on Hydraulic Fracturing in Synthetic Granite - a Discrete Element Study

    Science.gov (United States)

    Tomac, I.; Gutierrez, M.

    2015-12-01

    Hydraulic fracture initiation and propagation from a borehole in hard synthetic rock is modeled using the two dimensional Discrete Element Method (DEM). DEM uses previously established procedure for modeling the strength and deformation parameters of quasi-brittle rocks with the Bonded Particle Model (Itasca, 2004). A series of simulations of laboratory tests on granite in DEM serve as a reference for synthetic rock behavior. Fracturing is enabled by breaking parallel bonds between DEM particles as a result of the local stress state. Subsequent bond breakage induces fracture propagation during a time-stepping procedure. Hydraulic fracturing occurs when pressurized fluid induces hoop stresses around the wellbore which cause rock fracturing and serves for geo-reservoir permeability enhancement in oil, gas and geothermal industries. In DEM, a network of fluid pipes and reservoirs is used for mathematical calculation of fluid flow through narrow channels between DEM particles, where the hydro-mechanical coupling is fully enabled. The fluid flow calculation is superimposed with DEM stress-strain calculation at each time step. As a result, the fluid pressures during borehole pressurization in hydraulic fracturing, as well as, during the fracture propagation from the borehole, can be simulated. The objective of this study is to investigate numerically a hypothesis that fluid pressurization rate, or the fluid flow rate, influences upon character, shape and velocity of fracture propagation in rock. The second objective is to better understand and define constraints which are important for successful fracture propagation in quasi-brittle rock from the perspective of flow rate, fluid density, viscosity and compressibility relative to the rock physical properties. Results from this study indicate that not only too high fluid flow rates cause fracture arrest and multiple fracture branching from the borehole, but also that the relative compressibility of fracturing fluid and

  5. Lead-Related Genetic Loci, Cumulative Lead Exposure and Incident Coronary Heart Disease: The Normative Aging Study

    Science.gov (United States)

    Weisskopf, Marc G.; Sparrow, David; Schwartz, Joel; Hu, Howard; Park, Sung Kyun

    2016-01-01

    Background Cumulative exposure to lead is associated with cardiovascular outcomes. Polymorphisms in the δ-aminolevulinic acid dehydratase (ALAD), hemochromatosis (HFE), heme oxygenase-1 (HMOX1), vitamin D receptor (VDR), glutathione S-transferase (GST) supergene family (GSTP1, GSTT1, GSTM1), apolipoprotein E (APOE),angiotensin II receptor-1 (AGTR1) and angiotensinogen (AGT) genes, are believed to alter toxicokinetics and/or toxicodynamics of lead. Objectives We assessed possible effect modification by genetic polymorphisms in ALAD, HFE, HMOX1, VDR, GSTP1, GSTT1, GSTM1, APOE, AGTR1 and AGT individually and as the genetic risk score (GRS) on the association between cumulative lead exposure and incident coronary heart disease (CHD) events. Methods We used K-shell-X-ray fluorescence to measure bone lead levels. GRS was calculated on the basis of 22 lead-related loci. We constructed Cox proportional hazard models to compute adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for incident CHD. We applied inverse probability weighting to account for potential selection bias due to recruitment into the bone lead sub-study. Results Significant effect modification was found by VDR, HMOX1, GSTP1, APOE, and AGT genetic polymorphisms when evaluated individually. Further, the bone lead-CHD associations became larger as GRS increases. After adjusting for potential confounders, a HR of CHD was 2.27 (95%CI: 1.50–3.42) with 2-fold increase in patella lead levels, among participants in the top tertile of GRS. We also detected an increasing trend in HRs across tertiles of GRS (p-trend = 0.0063). Conclusions Our findings suggest that lead-related loci as a whole may play an important role in susceptibility to lead-related CHD risk. These findings need to be validated in a separate cohort containing bone lead, lead-related genetic loci and incident CHD data. PMID:27584680

  6. Electrochemical Studies of Lead Telluride Behavior in Acidic Nitrate Solutions

    Directory of Open Access Journals (Sweden)

    Rudnik E.

    2015-04-01

    Full Text Available Electrochemistry of lead telluride stationary electrode was studied in nitric acid solutions of pH 1.5-3.0. E-pH diagram for Pb-Te-H2O system was calculated. Results of cyclic voltammetry of Pb, Te and PbTe were discussed in correlation with thermodynamic predictions. Anodic dissolution of PbTe electrode at potential approx. -100÷50 mV (SCE resulted in tellurium formation, while above 300 mV TeO2 was mainly produced. The latter could dissolve to HTeO+2 under acidic electrolyte, but it was inhibited by increased pH of the bath.

  7. Feasibility Study of Synthetic Aperture Radar - Adaptability of the Payload to KOMPSAT Platform

    Directory of Open Access Journals (Sweden)

    Young-Soo Kim

    2002-09-01

    Full Text Available Synthetic Aperture Radar (SAR has been used for mapping the surface geomorphology of cloudy planets like Venus as well as the Earth. The cloud-free Mars is also going to be scanned by SAR in order to detect buried water channels and other features under the very shallow subsurface of the ground. According to the 'Mid and Long-term National Space Development Plan' of Korea, SAR satellites, in addition to the EO (Electro-Optical satellites, are supposed to be developed in the frame of the KOMPSAT (Korean Multi-Purpose Satellite program. Feasibility of utilizing a SAR payload on KOMPSAT platform has been studied by KARI in collaboration with Astrium U.K. The purpose of the SAR program is Scientific and Civil applications on the Earth. The study showed that KOMPSAT-2 platform can accommodate a small SAR like Astrium's MicroSAR. In this paper, system aspects of the satellite design are presented, such as mission scenario, operation concept, and capabilities. The spacecraft design is also discussed and conclusion is followed.

  8. A study on expelling lead with a traditional Chinese medicine

    International Nuclear Information System (INIS)

    Sun Aizhen; Guo Ruixin; Zhou Jieyan; Wang Dongfeng; Wang Huifang

    1993-01-01

    The rat model poisoned by lead acetate was treated with either EDTA or a traditional Chinese medicine (TCM) with the ability of 'relieving toxin and strengthening spleen'. In EDTA group, lead contents in blood fell to normal; the other parameters apparently improved but did not return to normal(p 0.05). But in TCM group, all the parameters returned to normal (p > 0.05) and the contents of essential trace elements in urine did not obviously change (p < 0.05). The curative effect of TCM is therefore better than that of EDTA. The mechanism probably lies in following points: (1) TCM can expedite excretion of lead in feces and decrease the lead accumulation in liver; (2) FEP returns to normal, showing that the lead expelling effect of TCM is relatively complete; (3) TCM does not disturb the interior equilibrium of essential trace elements while expelling lead

  9. Radiochemical and thermal studies of the copper(II)-exchanged form of synthetic zeolite linde sieve A

    International Nuclear Information System (INIS)

    Banerjee, S.P.

    1978-01-01

    Synthetic zeolite Linde Sieve A displays a double ion-sieve action. Only small cations can penetrate the single 6-rings into the beta cages. The radiochemical and thermal studies of copper(II)-exchanges form of 4A shows evidence of hydrated copper(II) ions in the zeolite structure. (author)

  10. An Internet Study of User's Experiences of the Synthetic Cathinone 4-Methylethcathinone (4-MEC).

    Science.gov (United States)

    Van Hout, Marie Claire

    2014-01-01

    Abstract A synthetic cathinone called 4-methylethcathinone (4-MEC) emerged online in 2010, and was cyber-marketed to be a replacement for mephedrone. The study aimed to present user experiences of 4-MEC as reported on the Internet, with a focus on user profiles, sourcing and product characteristics, routes of administration, dosage, positive and undesirable effects, and comparisons to mephedrone. Twenty-three individual, anonymous trip reports of the sole use of 4-MEC, and 112 screenshots of general 4-MEC user discussion boards, were taken from a purposeful sample of public drug-related sites. A content textual analysis was conducted on extracted qualitative information and produced 41 categories compiled into five general themes: "Type of 4-MEC user"; "Sourcing, informed decision making, product characteristics, and quality assurance"; "Routes of administration, gauging of dosage, and consumption of other drugs"; "Time course effects and outcomes"; and "Comparisons with mephedrone." 4-MEC is sold as white beads, crystalline shards, or green balls. User motives centered on curiosity, pricing, and ease of web sourcing. Oral, nasal, injecting, eyeball, and rectal routes of administration were described. Testing for purity, "allergy testing," and gauging of dosage were common. Users described euphoric but short-lived effects, with little comedown. Continued research is vital to inform harm reduction.

  11. Full Polarimetric Synthetic Aperture Radar (SAR) Data for ionosphere observation - A comparative study

    Science.gov (United States)

    Mohanty, S.; Singh, G.

    2017-12-01

    Ionosphere, predominantly, govern the propagation of radio waves, especially at L-band and lower frequencies. Small-scale, rapid fluctuations in the electron density, termed as scintillation phenomenon, cause rapid variations in signal amplitude and phase. Scintillation studies have been done using ground-based radio transmitter and beacon GPS signals. In this work, attempt has been made to utilize full polarimetric synthetic aperture radar (SAR) satellite signal at L-band (1.27 GHz) to develop a new measurement index for SAR signal intensity fluctuation. Datasets acquired from Japan's latest Advanced Land Observation Satellite (ALOS)-2 over the Indian subcontinent on two different dates, with varying ionospheric activities, have been utilized to compare the index. A 20% increase in the index values for a scintillation-affected day has been observed. The result coincides with the nature of ionospheric scintillation pattern typically observed over the equatorial belt. Total electron content values, for the two dates of acquisition, obtained from freely available Ionosphere Exchange (IONEX) data have been used to validate the varying ionospheric activities as well as the trend in index results. Another interesting finding of the paper is the demarcation of the equatorial anomaly belt. The index values are comparatively higher at these latitudes on a scintillation-affected day. Furthermore, the SAR signal intensity fluctuation index has great potential in being used as a preliminary measurement index to identify low frequency SAR data affected by ionospheric scintillation.

  12. Study on sorption capacity and characterization of Sr2+ on synthetic zeolite

    International Nuclear Information System (INIS)

    Wang Jinming; Yi Facheng

    2010-01-01

    Sr 2+ adsorption capacity of synthetic zeolite(ZF) are studied with the intermittence method, and ZF adsorbed the Sr 2+ is characterized and analyzed by XRD, as a reference for the evaluation of the disposal effectiveness of low and medium radwastes. The results show that Sr 2+ adsorption capacity of ZF is good, and the equilibrium time for ZF to adsorb Sr 2+ is in range of 5-14 days. Sr 2+ concentration has the greatest effect on ZF adsorption capacity,and the medium,temperature and pH value of the solution also have effect on ZF adsorption capacity. With the augment of Sr 2+ concentration,the Sr 2+ equilibrium adsorption quantity of ZF increases,but the equilibrium adsorption rate and equilibrium adsorption ratio decreases. Sr 2+ adsorption capacity of ZF improves with the augment of pH value. Sr 2+ adsorption capacity of ZF is complicate and varies with the different ion, concentration and other components in the medium solution. Sr 2+ adsorption capacity of ZF increases with the augment of temperature. As a whole, when Sr 2+ concentration in the solution is 0.005mol/L, the pH value of the solution, and the temperature of medium and solution have less effect on the Sr 2+ adsorption capacity of ZF, and the unit cell parameter of ZF adsorbed Sr 2+ decreases. (authors)

  13. Acromioclavicular joint reconstruction using the LockDown synthetic implant: a study with cadavers.

    Science.gov (United States)

    Taranu, R; Rushton, P R P; Serrano-Pedraza, I; Holder, L; Wallace, W A; Candal-Couto, J J

    2015-12-01

    Dislocation of the acromioclavicular joint is a relatively common injury and a number of surgical interventions have been described for its treatment. Recently, a synthetic ligament device has become available and been successfully used, however, like other non-native solutions, a compromise must be reached when choosing non-anatomical locations for their placement. This cadaveric study aimed to assess the effect of different clavicular anchorage points for the Lockdown device on the reduction of acromioclavicular joint dislocations, and suggest an optimal location. We also assessed whether further stability is provided using a coracoacromial ligament transfer (a modified Neviaser technique). The acromioclavicular joint was exposed on seven fresh-frozen cadaveric shoulders. The joint was reconstructed using the Lockdown implant using four different clavicular anchorage points and reduction was measured. The coracoacromial ligament was then transferred to the lateral end of the clavicle, and the joint re-assessed. If the Lockdown ligament was secured at the level of the conoid tubercle, the acromioclavicular joint could be reduced anatomically in all cases. If placed medial or 2 cm lateral, the joint was irreducible. If the Lockdown was placed 1 cm lateral to the conoid tubercle, the joint could be reduced with difficulty in four cases. Correct placement of the Lockdown device is crucial to allow anatomical joint reduction. Even when the Lockdown was placed over the conoid tubercle, anterior clavicle displacement remained but this could be controlled using a coracoacromial ligament transfer. ©2015 The British Editorial Society of Bone & Joint Surgery.

  14. A molecular dynamics and circular dichroism study of a novel synthetic antimicrobial peptide

    International Nuclear Information System (INIS)

    Rodina, N P; Yudenko, A N; Terterov, I N; Eliseev, I E

    2013-01-01

    Antimicrobial peptides are a class of small, usually positively charged amphiphilic peptides that are used by the innate immune system to combat bacterial infection in multicellular eukaryotes. Antimicrobial peptides are known for their broad-spectrum antimicrobial activity and thus can be used as a basis for a development of new antibiotics against multidrug-resistant bacteria. The most challengeous task on the way to a therapeutic use of antimicrobial peptides is a rational design of new peptides with enhanced activity and reduced toxicity. Here we report a molecular dynamics and circular dichroism study of a novel synthetic antimicrobial peptide D51. This peptide was earlier designed by Loose et al. using a linguistic model of natural antimicrobial peptides. Molecular dynamics simulation of the peptide folding in explicit solvent shows fast formation of two antiparallel beta strands connected by a beta-turn that is confirmed by circular dichroism measurements. Obtained from simulation amphipatic conformation of the peptide is analysed and possible mechanism of it's interaction with bacterial membranes together with ways to enhance it's antibacterial activity are suggested

  15. Study on sorption capacity of synthetic zeolite for simulated nuclide Cs+

    International Nuclear Information System (INIS)

    Wang Jinming; Yi Facheng

    2006-01-01

    For the sake of understanding the functionary order of simulated nuclide Cs + and Synthetic Zeolite (ZF), the sorption equilibrium time and sorption capacity of simulated nuclide Cs + on ZF are studied with the intermittence method. The difference of temperature, pH value, Cs + concentration and medium on sorption capacity and sorption ratio are investigated. The results show that the sorption complexion of simulated nuclide Cs + on ZF in the same concentration solution are sorption equilibrium quantity in range of 155-190 mg/g in different temperatures and that in range of 165-190 mg/g in different pH values and that in range of 120-210 mg/g in different media; and changing order of equilibrium adsorption ratio is the same to that of sorption equilibrium quantity, but their changing range are wider than that of sorption equilibrium quantity; equilibrium adsorption quantity in range of 180-380 mg/g in different concentration solutions, and changing order of equilibrium adsorption ratio is opposite to that of sorption equilibrium quantity, and more-over, their changing range are wider than that of the sorption equilibrium quantity. Sorption equilibrium time of simulated nuclide Cs + on ZF is about ten to fifteen days. So the changing range of sorption capacity of simulated nuclide Cs + on ZF with conditions effects is smaller and the sorption equilibrium time is also less and ZF preferably absorbs Cs in radiation wastes and thus consumedly reduces the effect of radwaste on the environment. (authors)

  16. Synthetic Brassica napus L.: Development and Studies on Morphological Characters, Yield Attributes, and Yield

    Directory of Open Access Journals (Sweden)

    M. A. Malek

    2012-01-01

    Full Text Available Brassica napus was synthesized by hybridization between its diploid progenitor species B. rapa and B. oleracea followed by chromosome doubling. Cross with B. rapa as a female parent was only successful. Among three colchicine treatments (0.10, 0.15, and 0.20%, 0.15% gave the highest success (86% of chromosome doubling in the hybrids (AC; 2=19. Synthetic B. napus (AACC, 2=38 was identified with bigger petals, fertile pollens and seed setting. Synthetic B. napus had increased growth over parents and exhibited wider ranges with higher coefficients of variations than parents for morphological and yield contributing characters, and yield per plant. Siliqua length as well as beak length in synthetic B. napus was longer than those of the parents. Number of seeds per siliqua, 1000-seed weight and seed yield per plant in synthetic B. napus were higher than those of the parents. Although flowering time in synthetic B. napus was earlier than both parents, however the days to maturity was little higher over early maturing B. rapa parent. The synthesized B. napus has great potential to produce higher seed yield. Further screening and evaluation is needed for selection of desirable genotypes having improved yield contributing characters and higher seed yield.

  17. An exploratory study of lead recovery in lead-acid battery lifecycle in US market: An evidence-based approach

    International Nuclear Information System (INIS)

    Genaidy, A.M.; Sequeira, R.; Tolaymat, T.; Kohler, J.; Rinder, M.

    2008-01-01

    Background: This research examines lead recovery and recycling in lead-acid batteries (LAB) which account for 88% of US lead consumption. We explore strategies to maximize lead recovery and recycling in the LAB lifecycle. Currently, there is limited information on recycling rates for LAB in the published literature and is derived from a single source. Therefore, its recycling efforts in the US has been unclear so as to determine the maximum opportunities for metal recovery and recycling in the face of significant demands for LAB particularly in the auto industry. Objectives: The research utilizes an evidence-based approach to: (1) determine recycling rates for lead recovery in the LAB product lifecycle for the US market; and (2) quantify and identify opportunities where lead recovery and recycling can be improved. Methods: A comprehensive electronic search of the published literature was conducted to gather information on different LAB recycling models and actual data used to calculate recycling rates based on product lifecycle for the US market to identify strategies for increasing lead recovery and recycling. Results: The electronic search yielded five models for calculating LAB recycling rates. The description of evidence was documented for each model. Furthermore, an integrated model was developed to identify and quantify the maximum opportunities for lead recovery and recycling. Results showed that recycling rates declined during the period spanning from 1999 to 2006. Opportunities were identified for recovery and recycling of lead in the LAB product lifecycle. Concluding remarks: One can deduce the following from the analyses undertaken in this report: (1) lead recovery and recycling has been stable between 1999 and 2006; (2) lead consumption has increased at an annual rate of 2.25%, thus, the values derived in this study for opportunities dealing with lead recovery and recycling underestimate the amount of lead in scrap and waste generated; and (3) the

  18. Lead arthritis and lead poisoning following bullet wounds: a clinicopathologic, ultrastructural, and microanalytic study of two cases.

    Science.gov (United States)

    Slavin, R E; Swedo, J; Cartwright, J; Viegas, S; Custer, E M

    1988-02-01

    Bullet wounds causing lead synovitis in the wrist and knee are reported in two patients, one of whom also developed clinical plumbism. Very high lead levels in the synovial fluid are believed to be responsible for toxicity changes that occurred in the synovium and bone. Ultrastructurally, these alterations included the formation of nuclear lead inclusions, dilation, and degranulation of the rough endoplasmic reticulum and deposition of crystalline precipitates in the matrix of the mitochondria in macrophages, osteoclasts, and synoviocytes, as well as the development of cytoplasmic lead inclusions in osteoclasts. Energy-dispersive x-ray elemental analysis (EDXEA) indicated that the nuclear inclusions contained only lead, whereas precipitates within the mitochondria and elsewhere in the cytoplasm were composed of complexes containing lead, calcium, and phosphorus. Similarly constituted extracellular complexes were incorporated into newly formed trabecular bone laid down as a physiologic response to the bullet lodged within the wrist bones. This bone subsequently exhibited defects in bone resorption, which were characterized by depressed osteoclastic function and a unique lesion termed incomplete osteocytic osteolysis. The genesis of this latter lesion is uncertain. The sequestration of the partially degraded bone fragments containing lead complexes into the marrow and eventually into the joint spaces and synovium permitted the recycling of bone lead, and this may have played an important role in inducing clinical plumbism in one of the patients in this study.

  19. A lead isotopic study of the human bioaccessibility of lead in urban soils from Glasgow, Scotland

    International Nuclear Information System (INIS)

    Farmer, John G.; Broadway, Andrew; Cave, Mark R.; Wragg, Joanna; Fordyce, Fiona M.; Graham, Margaret C.; Ngwenya, Bryne T.; Bewley, Richard J.F.

    2011-01-01

    The human bioaccessibility of lead (Pb) in Pb-contaminated soils from the Glasgow area was determined by the Unified Bioaccessibility Research Group of Europe (BARGE) Method (UBM), an in vitro physiologically based extraction scheme that mimics the chemical environment of the human gastrointestinal system and contains both stomach and intestine compartments. For 27 soils ranging in total Pb concentration from 126 to 2160 mg kg -1 (median 539 mg kg -1 ), bioaccessibility as determined by the 'stomach' simulation (pH ∼ 1.5) was 46-1580 mg kg -1 , equivalent to 23-77% (mean 52%) of soil total Pb concentration. The corresponding bioaccessibility data for the 'stomach + intestine' simulation (pH ∼ 6.3) were 6-623 mg kg -1 and 2-42% (mean 22%) of soil Pb concentration. The soil 206 Pb/ 207 Pb ratios ranged from 1.057 to 1.175. Three-isotope plots of 208 Pb/ 206 Pb against 206 Pb/ 207 Pb demonstrated that 206 Pb/ 207 Pb ratios were intermediate between values for source end-member extremes of imported Australian Pb ore (1.04) - used in the manufacture of alkyl Pb compounds (1.06-1.10) formerly added to petrol - and indigenous Pb ores/coal (1.17-1.19). The 206 Pb/ 207 Pb ratios of the UBM 'stomach' extracts were similar ( 206 Pb/ 207 Pb ratio was discernible in the UBM. However, the source of Pb appeared to be less important in determining the extent of UBM-bioaccessible Pb than the overall soil total Pb concentration and the soil phases with which the Pb was associated. The significant phases identified in a subset of samples were carbonates, manganese oxides, iron-aluminium oxyhydroxides and clays. - Highlights: → We determined the human bioaccessibility of Pb in urban soils by in vitro extraction. → We determined the isotopic composition of Pb in soils and simulated stomach extracts. → Soil stable Pb isotope ratios (e.g. 206 Pb/ 207 Pb) indicated a range of sources of Pb. → 206 Pb/ 207 Pb ratios in soils and their simulated stomach extracts were very similar

  20. A lead isotopic study of the human bioaccessibility of lead in urban soils from Glasgow, Scotland

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, John G., E-mail: J.G.Farmer@ed.ac.uk [School of GeoSciences, University of Edinburgh, Edinburgh, EH9 3JN, Scotland (United Kingdom); Broadway, Andrew [School of GeoSciences, University of Edinburgh, Edinburgh, EH9 3JN, Scotland (United Kingdom); Cave, Mark R.; Wragg, Joanna [British Geological Survey, Keyworth, Nottingham NG12 5GG, England (United Kingdom); Fordyce, Fiona M. [British Geological Survey, Edinburgh, EH9 3LA, Scotland (United Kingdom); Graham, Margaret C.; Ngwenya, Bryne T. [School of GeoSciences, University of Edinburgh, Edinburgh, EH9 3JN, Scotland (United Kingdom); Bewley, Richard J.F. [URS Corporation Ltd, Manchester, M1 6HS, England (United Kingdom)

    2011-11-01

    The human bioaccessibility of lead (Pb) in Pb-contaminated soils from the Glasgow area was determined by the Unified Bioaccessibility Research Group of Europe (BARGE) Method (UBM), an in vitro physiologically based extraction scheme that mimics the chemical environment of the human gastrointestinal system and contains both stomach and intestine compartments. For 27 soils ranging in total Pb concentration from 126 to 2160 mg kg{sup -1} (median 539 mg kg{sup -1}), bioaccessibility as determined by the 'stomach' simulation (pH {approx} 1.5) was 46-1580 mg kg{sup -1}, equivalent to 23-77% (mean 52%) of soil total Pb concentration. The corresponding bioaccessibility data for the 'stomach + intestine' simulation (pH {approx} 6.3) were 6-623 mg kg{sup -1} and 2-42% (mean 22%) of soil Pb concentration. The soil {sup 206}Pb/{sup 207}Pb ratios ranged from 1.057 to 1.175. Three-isotope plots of {sup 208}Pb/{sup 206}Pb against {sup 206}Pb/{sup 207}Pb demonstrated that {sup 206}Pb/{sup 207}Pb ratios were intermediate between values for source end-member extremes of imported Australian Pb ore (1.04) - used in the manufacture of alkyl Pb compounds (1.06-1.10) formerly added to petrol - and indigenous Pb ores/coal (1.17-1.19). The {sup 206}Pb/{sup 207}Pb ratios of the UBM 'stomach' extracts were similar (< 0.01 difference) to those of the soil for 26 of the 27 samples (r = 0.993, p < 0.001) and lower in 24 of them. A slight preference for lower {sup 206}Pb/{sup 207}Pb ratio was discernible in the UBM. However, the source of Pb appeared to be less important in determining the extent of UBM-bioaccessible Pb than the overall soil total Pb concentration and the soil phases with which the Pb was associated. The significant phases identified in a subset of samples were carbonates, manganese oxides, iron-aluminium oxyhydroxides and clays. - Highlights: {yields} We determined the human bioaccessibility of Pb in urban soils by in vitro extraction. {yields} We

  1. Study of lead pollution from automobile emissions in Khartoum

    International Nuclear Information System (INIS)

    Ibrahim, A.S.

    2002-07-01

    Aerosol and soil samples were collected from places near the main roads in Khartoum area. The samples were analyzed by energy Dispersive x-ray fluorescence (EDXRF) technique, to study the lead (Pb) concentration in air and soil near roadsides due to automobile emissions. The aim of the study was also to make a comparison with the results of previous measurements made in the same field (Ahmed, 1983) . Thee aerosol samples were taken from three sites in Khartoum area. Tuti island taken as a control area, central Khartoum as a commercial area and south of Khartoum as a residential area. Soil samples were taken from a place near Al Gurashi Park and another near Abu Hamama traffic junction in Khartoum area. The data obtained of (Pb) concentrations in the roadside air were statistically analyzed. Comparisons were made between the concentrations at the various times of the day and correlation were made with meteorological parameters. The (Pb) concentrations in the roadside soil were observed to be inversely proportional to the distance from the road and the depth from the layer of the earth. Finally, the results obtained are discussed and some recommendations are suggested. (Author)

  2. Removal of phenol from synthetic wastewater using carbon-mineral composite: Batch mechanisms and composition study

    Science.gov (United States)

    Kamaruddin, Mohamad Anuar; Alrozi, Rasyidah; Aziz, Hamidi Abdul; Han, Tan Yong; Yusoff, Mohd Suffian

    2017-09-01

    This study investigates the treatability of composite adsorbent made from waste materials and minerals which is widely available in Malaysia. The composite adsorbent was prepared based on wet attrition method which focuses on the determination of optimum dosage of each of raw materials amount by conventional design of experiment work. Zeolite, activated carbon, rice husk and limestone were ground to obtained particle size of 150 µm. 45.94% zeolite, 15.31% limestone, 4.38% activated carbon, 4.38% rice husk carbon and 30% of ordinary Portland cement (OPC). The mixture was mixed together under pre-determined mixing time. About 60% (by weight) of water was added and the mixture paste was allowed to harden for 24 hours and then submersed in water for three days for curing. Batch experimental study was performed on synthetic dissolving a known amount of solid crystal phenol with distilled water into the volumetric flasks. From the batch experimental study, it was revealed that the optimum shaking speed for removal of phenol was 200 rpm. The removal efficiency was 65%. The optimum shaking time for removing phenol was 60 minutes; the percentage achieved was 55%. The removal efficiency increased with the increased of the amount of composite adsorbent. The removal efficiency for optimum adsorbent dosage achieved 86%. Furthermore, the influence of pH solution was studied. The optimum pH for removing phenol was pH 6, with the removal percentage of 95%. The results implies that carbon-mineral based composite adsorbent is promising replacement for commercial adsorbent that provides alternative source for industrial adsorption application in various types of effluent treatment system.

  3. EPR spectra of synthetic, and natural Australian opals - A pilot study

    International Nuclear Information System (INIS)

    Hutton, D.R.; Troup, G.J.

    1996-01-01

    Full text: The EPR spectra of some synthetic opals, and of some Australian natural opals of various provenance, have been obtained, with the use of a Varian E-12 EPR spectrometer operating at ∼9.2 Ghz. The synthetic opals, from Swiss Gilson showed here a broad ESR signal in the g =2 region, with little identifiable structure . The natural Australian opals from Coober Pedy, Lightning Ridge, and Mintabie all showed the clear presence of Fe 3+ , Mn 2+ and a free radical like signal, suspected to be localised on an Al atom. Examples of the various spectra will be presented. It is not yet certain how the spectra correlate with provenance, but the synthetic spectra are quite different from the natural ones

  4. Biogeochemical studies of lead isotopes near a smelter

    International Nuclear Information System (INIS)

    Landrigan, P.J.; Baker, E.L. Jr.; Earl, J.L.; Chow, T.J.

    1975-01-01

    Ninety-nine percent of 1 to 9 year-old children living within 1 mile of a primary lead smelter in Idaho were found to have whole blood lead levels equal to or greater than 40μg/100 ml, a level indicative of excess lead absorption. To define the sources of this lead, isotope ratios were determined in lead from human and environmental samples obtained near the smelter; determinations were performed using a 30-cm radius, solid-source mass spectrometer with an electron multiplier. The Idaho ore is a pre-Cambrian lead deposit with 206 Pb/ 204 Pb = 16.43, 206 Pb = 1.0543 and 206 Pb/ 208 Pb = 0.4518. An ingot smelted in 1974 showed isotope ratios of 206 Pb/ 204 Pb = 17.66, 206 Pb/ 207 Pb = 1.1312 and 206 Pb/ 208 Pb = 0.4694, indicating a mixture of ore sources. Three surface soil samples from within 2 miles of the smelter had lead ratios similar to those in the ingot. A fourth soil sample from beside an interstate highway 32 miles east of the smelter showed different ratios: 206 Pb/ 204 Pb = 18.47, 206 Pb/ 207 Pb = 1.1826 and 206 Pb/ 208 Pb = 0.4823. Aerosol samples collected from October 4, 1974, to February 1, 1975, near the smelter showed considerable variation in ratios; these variations resulted from smelting of ores from differing sources

  5. Micropipette Technique Study of Natural and Synthetic Lung Surfactants at the Air–Water Interface

    DEFF Research Database (Denmark)

    Ortiz, Elisa Parra; Kinoshita, K.; Needham, D.

    2016-01-01

    at microscopic air-water interfaces in real time and upon compression. Here, we characterized a series of animal-derived and synthetic lung surfactant formulations, including native surfactant obtained from porcine lungs (NS); the commercial Curosurf, Infasurf, and Survanta; and a synthetic Super Mini-B (SMB...... of myelin figures, proposing a combined mechanism between dehydration-rehydration of the lipid bilayers and induction of mechanical defects by SMB that would act as nucleation sites for the tubes. The formation of tubes was also observed in Infasurf, and in NS only after subsequent expansion and compression...

  6. CUSTOMER PERCEIVED QUALITY IMPROVEMENT OF SYNTHETIC FIBER USING FUZZY QFD: A CASE STUDY

    OpenAIRE

    Golam Kabir; M. Ahsan Akhtar Hasin

    2011-01-01

    The performance of the ready-made garment (RMG) industry has been one of the most notable success stories of the Bangladesh economy over two decades. To meet the growing demand of synthetic yarns, Bangladesh has to import it from foreign countries which cost a substantial amount of foreign currency for the country. It is a pressing need for local manufacturers to come forward, produce quality synthetic yarn and fulfill the demand of the local market. The purpose of this paper is to present a ...

  7. Synthetic environments

    Science.gov (United States)

    Lukes, George E.; Cain, Joel M.

    1996-02-01

    The Advanced Distributed Simulation (ADS) Synthetic Environments Program seeks to create robust virtual worlds from operational terrain and environmental data sources of sufficient fidelity and currency to interact with the real world. While some applications can be met by direct exploitation of standard digital terrain data, more demanding applications -- particularly those support operations 'close to the ground' -- are well-served by emerging capabilities for 'value-adding' by the user working with controlled imagery. For users to rigorously refine and exploit controlled imagery within functionally different workstations they must have a shared framework to allow interoperability within and between these environments in terms of passing image and object coordinates and other information using a variety of validated sensor models. The Synthetic Environments Program is now being expanded to address rapid construction of virtual worlds with research initiatives in digital mapping, softcopy workstations, and cartographic image understanding. The Synthetic Environments Program is also participating in a joint initiative for a sensor model applications programer's interface (API) to ensure that a common controlled imagery exploitation framework is available to all researchers, developers and users. This presentation provides an introduction to ADS and the associated requirements for synthetic environments to support synthetic theaters of war. It provides a technical rationale for exploring applications of image understanding technology to automated cartography in support of ADS and related programs benefitting from automated analysis of mapping, earth resources and reconnaissance imagery. And it provides an overview and status of the joint initiative for a sensor model API.

  8. Synthetic peptides for antibody production

    NARCIS (Netherlands)

    Zegers, N.D.

    1995-01-01

    Synthetic peptides are useful tools for the generation of antibodies. The use of antibodies as specific reagents in inununochemical assays is widely applied. In this chapter, the application of synthetic peptides for the generation of antibodies is described. The different steps that lead to the

  9. Pulse radiolysis for the study of lead salt solutions

    International Nuclear Information System (INIS)

    Breitenkamp, M.

    1976-01-01

    The Pb + ions are produced from Pb 2 + in lead perchlorate solutions by reduction with hydrated electrons, and the absorption spectrum of this ion has been measured together with a time differential observation in the micro- and millisecond range of the disparation of these ions from the solution in the presence of different substances. For these studies the method of pulsed radiolysis has been applied, detecting the short lifed intermediate reaction products by optical absorption and electric conductivity measurements. First an attempt has been made to produce the Pb + ions also by reduction of Pb 2 + with H-atoms. If Pb + and H is produced simultaneously in an aqueous solution the reaction Pb + + H -> PbH + can occur. The absorption spectrum of the short lifed species PbH + has been studied together with the second order evanescence. In addition Pb 2 + has been reduced by i-propanol radicals at high Pb 2 + concentrations. The second order evanescence has been observed and the rate constant of the reaction 2Pb + -> Pb + Pb 2 + has been measured. The Pb 2 + ions can also be reduced by CO 2- radicals, which are formed in the presence of formiate. The observations can be interpreted by the assumption of the primary reaction Pb 2 + + CO 2- -> PbCO 2+ . the spectrum of the product PbCO 2+ has been measured. A second order reaction of PbCO 2+ is observed with a resulting unstable particle of the structure Pb 2 CO 2 2 + . Finally the oxidation of Pb + by the OH-radical and by hydrogen peroxide has been studied. (orig./HK) [de

  10. Selectivity in Ligand Binding to Uranyl Compounds: A Synthetic, Structural, Thermodynamic and Computational Study

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, John [Univ. of California, Berkeley, CA (United States)

    2017-12-06

    The uranyl cation (UO22+) is the most abundant form of uranium on the planet. It is estimated that 4.5 billion tons of uranium in this form exist in sea water. The ability to bind and extract the uranyl cation from aqueous solution while separating it from other elements would provide a limitless source of nuclear fuel. A large body of research concerns the selective recognition and extraction of uranyl. A stable molecule, the cation has a linear O=U=O geometry. The short U-O bonds (1.78 Å) arise from the combination of uranium 5f/6d and oxygen 2p orbitals. Due to the oxygen moieties being multiply bonded, these sites were not thought to be basic enough for Lewis acidic coordination to be a viable approach to sequestration. We believe that the goal of developing a practical system for uranium separation from seawater will not be attained without new insights into our existing fundamental knowledge of actinide chemistry. We posit that detailed studies of the kinetic and thermodynamic factors that influence interactions between f-elements and ligands with a range of donor atoms is essential to any major advance in this important area. The goal of this research is thus to broaden the coordination chemistry of the uranyl ion by studying new ligand systems via synthetic, structural, thermodynamic and computational methods. We anticipate that this fundamental science will find use beyond actinide separation technologies in areas such as nuclear waste remediation and nuclear materials.

  11. Lead macro-encapsulation conceptual and experimental studies

    International Nuclear Information System (INIS)

    Orebaugh, E.G.

    1993-01-01

    Macro-encapsulation, the regulatory treatment for radioactively contaminated lead (mixed) waste has been conceptually and experimentally evaluated for practical application. Epoxy encapsulants molded around lead billets have proven to be exceptionally rugged, easily applied, have high radiation and chemical stability, and minimize required process equipment and production of secondary wastes. This technology can now be considered developed, and can be applied as discussed in this report

  12. Studies of synthetic single crystal diamonds as reliable dosimeters for electromagnetic ionizing radiation fields

    International Nuclear Information System (INIS)

    Pillon, Mario; Angelone, Maurizio; Almaviva, Salvatore; Marinelli, Marco; Milani, Enrico; Prestopino, Giuseppe; Tucciarone, Aldo; Verona, Claudio; Verona-Rinati, Gianluca; Baccaro, Stefania

    2008-01-01

    Full text: Spatial high resolution dosimetry is very important in all areas of radiation therapy and, in particular, whenever narrow photon beams are required for Stereotactic Radiotherapy (SRT) and small field segments are used for Intensity Modulated Radiotherapy (IMRT). The available detectors are often too large with respect to the beam size considered, which is characterized by high dose gradients and lack of charged particle equilibrium. An ideal solution is represented by single crystal diamond detectors, which are small solid state devices, radiation hard, tissue equivalent and capable of real time response. In the present work, synthetic CVD single crystal diamond dosimeters (SCD), fabricated at Rome 'Tor Vergata' University Laboratories, have been characterized. The devices consist of a p-type/intrinsic/metal layered structure. They have been analyzed in terms of reproducibility, linearity, depth dose distributions, energy, dose rate and field size dependence by using 6 and 10 MV Bremsstrahlung x-ray beams, produced by a CLINAC DHX Varian accelerator and the gamma irradiation facility CALLIOPE. The gamma Calliope plant is a pool-type irradiation facility equipped with the 60 Co γ-source in a high-volume (7 x 6 x 3.9m 3 ). Maximum dose rate is 9400 Gy/h. The measurements have been compared with a calibrated ionization chamber and a Fricke dosimeter. The SCD's response is shown to be linearly correlated with the ionization chamber output over the whole dose range explored. Reproducibility, energy and dose rate dependency lower than 1% were observed. A depth dose distribution and irradiation field dependence in agreement with those obtained by reference dosimeters within 2% of accuracy were demonstrated as well. The results of this study are very encouraging about the suitability of SCD for clinical dosimetry with photon beams. (author)

  13. Synthetic Defects for Vibrothermography

    Science.gov (United States)

    Renshaw, Jeremy; Holland, Stephen D.; Thompson, R. Bruce; Eisenmann, David J.

    2010-02-01

    Synthetic defects are an important tool used for characterizing the performance of nondestructive evaluation techniques. Viscous material-filled synthetic defects were developed for use in vibrothermography (also known as sonic IR) as a tool to improve inspection accuracy and reliability. This paper describes how the heat-generation response of these VMF synthetic defects is similar to the response of real defects. It also shows how VMF defects can be applied to improve inspection accuracy for complex industrial parts and presents a study of their application in an aircraft engine stator vane.

  14. Heating stage Raman and infrared emission spectroscopic study of the dehydroxylation of synthetic Mg-hydrotalcite

    International Nuclear Information System (INIS)

    Kloprogge, J.T.; Hickey, L.; Frost, R.L.

    1998-01-01

    Full text: Hydrotalcites, also described as anionic clays or layered double hydroxides (LDH), form an important group of compounds because of their catalytic (basic) activity, as a precursor for the preparation of oxidic catalysts as for other specific powder properties such as filler, UV-radiation stabiliser, chloride scavenger and thermal stabiliser (Titulaer, 1993). The structure of hydrotalcites can be visualised as positively charged hydroxide layers comparable to the hydroxide layers in brucite, Mg(OH) 2 , in which a part of the divalent metal is substituted by a trivalent metal separated by charge compensating mostly hydrated anions in a so-called interlayer between the hydroxide layers. In both naturally occurring and synthetic hydrotalcites a broad range of compositions are possible of the type [M 2+ 1-x M 3+ x (OH) 2 ][A n- ] x/n. yH 2 O, where M 2+ and M 3+ are the di- and trivalent cations in the octahedral positions within the hydroxide layers with x normally between 0.17 and 0.33. A n- is an exchangeable interlayer anion. The thermal behaviour of hydrotalcites is of importance for a number of applications indicated above. For example, when a hydrotalcite is used as a precursor for the preparation of mixed metal oxide catalysts the dehydration, decarbonisation and dehydroxylation reactions must be well known in order to control the final reaction product. The hydrotalcite Mg 6 Al 2 (OH) 16 CO 3 .nH 2 O was synthesised according to the method described before by Kloprogge and Frost (1999a,b). This method comprises the slow simultaneous addition of a mixed aluminium nitrate (0.25M)-magnesium nitrate (0.75M), aluminium nitrate (0.25M)-solutions and a mixed NaOH (2.00M)-Na 2 CO 3 (0.125M) solution under vigorous stirring buffering the pH at approximately 10. The product was washed to eliminate excess salt and dried at 60 deg C. The thermal behaviour of synthetic hydrotalcite, Mg 6 Al 2 (OH)O 16 CO 3 .nH 2 O, has been studied by Infrared Emission

  15. Lead Apron Inspection Using Infrared Light: A Model Validation Study.

    Science.gov (United States)

    McKenney, Sarah E; Otero, Hansel J; Fricke, Stanley T

    2018-02-01

    To evaluate defect detection in radiation protective apparel, typically called lead aprons, using infrared (IR) thermal imaging. The use of IR lighting eliminates the need for access to x-ray-emitting equipment and radiation dose to the inspector. The performance of radiation workers was prospectively assessed using both a tactile inspection and the IR inspection with a lead apron phantom over a 2-month period. The phantom was a modified lead apron with a series of nine holes of increasing diameter ranging from 2 to 35 mm in accordance with typical rejection criteria. Using the tactile method, a radiation worker would feel for the defects in the lead apron. For the IR inspection, a 250-W IR light source was used to illuminate the lead apron phantom; an IR camera detected the transmitted radiation. The radiation workers evaluated two stills from the IR camera. From the 31 participants inspecting the lead apron phantom with the tactile method, only 2 participants (6%) correctly discovered all 9 holes and 1 participant reported a defect that was not there; 10 of the 20 participants (50%) correctly identified all 9 holes using the IR method. Using a weighted average, 5.4 defects were detected with the tactile method and 7.5 defects were detected with the IR method. IR light can penetrate an apron's protective outer fabric and illuminate defects below the current standard rejection size criteria. The IR method improves defect detectability as compared with the tactile method. Copyright © 2017 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  16. Study on lead extrusion damper as a seismic support

    International Nuclear Information System (INIS)

    Nomura, T.; Kojima, N.; Fujita, K.; Ito, T.

    1989-01-01

    The fundamental characteristics of two types of lead extrusion dampers (cylinder type, rotary type) for use as the nuclear power plant piping support of the elasto-plastic of damper are clarified. As a result, these lead extrusion dampers are found to have the following dynamic characteristics: hysteresis loop is both rectangular shape and bi-linear shape; maximum reaction force is independent of velocity and frequency but it increases as displacement exceeds the specified value; and the dissipated energy is very large and is independent of velocity, frequency and initial displacement (i.e., thermal expansion of pipings) in the range of test

  17. Study of neutron and gamma shielding by lead borate and bismuth lead borate glasses: transparent radiation shielding

    International Nuclear Information System (INIS)

    Singh, Vishwanath P.; Badiger, N.M.

    2013-01-01

    Radiation shielding for gamma and neutron is the prominent area in nuclear reactor technology, medical application, dosimetry and other industries. Shielding of these types of radiation requires an appropriate concrete with mixture of low-to-high Z elements which is an opaque medium. The transparent radiation shielding in visible light for gamma and neutron is also extremely essential in the nuclear facilities as lead window. Presently various types of lead equivalent glass oxides have been invented which are transparent as well as provide protection from radiation. In our study we have assessment of effectiveness of neutron and gamma radiation shielding of xPbO.(1-x) B 2 O 3 (x=0.15 to 0.60) and xBi 2 O 3 .(0.80-x) PbO.0.20 B 2 O 3 (x=0.10 to 0.70) transparent borate and bismuth glasses by NXCOM program. The neutron effective mass removal cross section, Σ R /ρ (cm 2 /g) of the lead, bismuth and boron oxides are given. We found invariable Σ R /ρ of various combinations of the lead borate glass for x=0.15 to 0.60 and bismuth lead borate glass for x=0.10 to 0.70. It is observed that the effective removal cross-section for fast neutron (cm -1 ) of lead borate reduces significantly whereas roughly constant for bismuth borate. The gamma mass attenuation coefficients (μ/ρ) of the glasses were also compared with possible experimental values and found comparable. High (μ/ρ) for gamma radiation of the bismuth glasses shows that it is better gamma shielding compared with lead containing glass. However lead borate glasses are better neutron shielding as the neutron removal coefficient are higher. Our investigation is very useful for nuclear reactor technology where prompt neutron of energy 17 MeV and gamma photon up to 10 MeV produced. (author)

  18. Synthetic Rutile

    International Nuclear Information System (INIS)

    Burastero, J.

    1975-01-01

    This work is about the laboratory scale investigation of the conditions in the rutile synthetic production from one me nita in Aguas Dulces reservoir. The iron mineral is chlorinated and volatilized selectively leaving a residue enriched in titanium dioxide which can be used as a substitute of rutile mineral

  19. A laboratory study of removing Arsenic from a synthetic copper concentrate

    International Nuclear Information System (INIS)

    Tajadod, J.

    2000-01-01

    Arsenic is the 20th most abundant element if the earth's crust at a level of about 2 ppm. It is a constituent of over 300 minerals and is commonly found in non-ferrous ores such as copper, lead, zinc, gold and uranium. Efficient separation of arsenic minerals from other sulphide minerals is of great importance for the metallurgical performance of flotation processes. This work was undertaken to study the separation of engirt, an arsenic-bearing mineral from chalcopyrite in copper concentrates. To achieve this aim the possible depression of engirt using some sulphide depressants was studied

  20. New Synthetic Methods for Hypericum Natural Products

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Insik [Iowa State Univ., Ames, IA (United States)

    2006-01-01

    Organic chemistry has served as a solid foundation for interdisciplinary research areas, such as molecular biology and medicinal chemistry. An understanding of the biological activities and structural elucidations of natural products can lead to the development of clinically valuable therapeutic options. The advancements of modern synthetic methodologies allow for more elaborate and concise natural product syntheses. The theme of this study centers on the synthesis of natural products with particularly challenging structures and interesting biological activities. The synthetic expertise developed here will be applicable to analog syntheses and to other research problems.

  1. Rubidium-strontium and uranium-lead isotopic age studies

    International Nuclear Information System (INIS)

    Loveridge, W.D.

    1980-01-01

    Rubidium-strontium whole rock isochron ages and initial 87 Sr/ 86 Sr ratios and uranium-lead ages on zircon from suites of samples selected from localities across Canada are presented. Descriptions of the geological probelms and interpretations of the measured ages are included. Laboratory age determination methods and techniques are described or referenced. (auth)

  2. Simulation Study of Real Time 3-D Synthetic Aperture Sequential Beamforming for Ultrasound Imaging

    DEFF Research Database (Denmark)

    Hemmsen, Martin Christian; Rasmussen, Morten Fischer; Stuart, Matthias Bo

    2014-01-01

    in the main system. The real-time imaging capability is achieved using a synthetic aperture beamforming technique, utilizing the transmit events to generate a set of virtual elements that in combination can generate an image. The two core capabilities in combination is named Synthetic Aperture Sequential......This paper presents a new beamforming method for real-time three-dimensional (3-D) ultrasound imaging using a 2-D matrix transducer. To obtain images with sufficient resolution and contrast, several thousand elements are needed. The proposed method reduces the required channel count from...... Beamforming (SASB). Simulations are performed to evaluate the image quality of the presented method in comparison to Parallel beamforming utilizing 16 receive beamformers. As indicators for image quality the detail resolution and Cystic resolution are determined for a set of scatterers at a depth of 90mm...

  3. Comparative study of hydroxyapatite from eggshells and synthetic hydroxyapatite for bone regeneration.

    Science.gov (United States)

    Lee, Sang-Woon; Kim, Seong-Gon; Balázsi, Csaba; Chae, Weon-Sik; Lee, Hee-Ok

    2012-03-01

    The objective of this study was to evaluate the physical properties of synthetic hydroxyapatite (sHA) and hydroxyapatite from eggshells (eHA) by Fourier-transform infrared (FT-IR) and x-ray diffraction (XRD) and to compare the regenerative ability of the bone using sHA and eHA in a rabbit calvarial defect model. FT-IR and XRD were used to compare the physical properties of sHA and eHA. sHA was purchased from Sigma, and eHA was kindly donated from the Hungarian academy of science. Sixteen New Zealand white rabbits were used for the animal study. After the formation of a bilateral parietal bony defect (diameter 8.0 mm), either sHA or eHA was grafted into the defect. The defect in the control was left unfilled. Bone regeneration was evaluated by histomorphometry at 4 and 8 weeks after the operation. The peak broadening of the XRD experiments were in agreement with scanning electron microscope observation; the sHA had a smaller granule size than the eHA. The eHA had impurities phases of CaO (International Center for Diffraction Data (ICDD) 075-0264) and Ca(OH)(2) (ICDD 072-0156). Total new bone was 17.11 ± 10.24% in the control group, 28.81 ± 12.63% in sHA group, and 25.68 ± 10.89% in eHA group at 4 weeks after the operation. The difference was not statistically significant (P > .05). Total new bone at 8 weeks after the operation was 27.50 ± 10.89% in the control group, 38.62 ± 17.42% in sHA group, and 41.99 ± 8.44% in the eHA group. When comparing the sHA group to the control group, the difference was not statistically significant (P > .05). However, the eHA group was significantly different from the control group (P = .038). When comparing the eHA group to the sHA group, the difference was not statistically significant (P > .05). Both types of HA showed higher bone formation than the unfilled control. However, eHA had significantly higher bone formation than the unfilled control at 8 weeks after operation. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Magnetic studies on synthetic phosphoferrite Fe2+3(H2O)3(PO4)2

    International Nuclear Information System (INIS)

    Moreira, L.F.; Diehl, L.M.A.; Torres-Tapia, E.C.; Domingues, P.H.; Mattievich, E.

    1994-01-01

    Synthetic crystals of phosphoferrite were studied by Moessbauer spectroscopy for temperatures ranging from 4.2 to 17.5 K. The analysis of the behaviour of the hyperfine fields for the two unequivalent sites near the Neel temperature (17.4 K) allowed the determination of the critical exponent β for each site as β 1 = 0.171 and β 2 = 0.314. (orig.)

  5. CUSTOMER PERCEIVED QUALITY IMPROVEMENT OF SYNTHETIC FIBER USING FUZZY QFD: A CASE STUDY

    Directory of Open Access Journals (Sweden)

    Golam Kabir

    2011-06-01

    Full Text Available The performance of the ready-made garment (RMG industry has been one of the most notable success stories of the Bangladesh economy over two decades. To meet the growing demand of synthetic yarns, Bangladesh has to import it from foreign countries which cost a substantial amount of foreign currency for the country. It is a pressing need for local manufacturers to come forward, produce quality synthetic yarn and fulfill the demand of the local market. The purpose of this paper is to present a Fuzzy Quality Function Deployment (FQFD model to indentify customer requirements and also demonstrate how these requirements can be used to prioritize the design requirements for manufacturing of synthetic yarns. In this system, Fuzzy set theory is integrated into house of quality (HOQ to overcome the shortcomings of the traditional QFD and to capture the inherent impreciseness and vagueness of customer requirements and facilitate to prioritize QFD information. Improving high priority design requirements will ultimately increase customer satisfaction and as a result customer perceived quality will soar.

  6. Study on the effect of lead and lead compounds as pollutants on traffic air and traffic policemen

    International Nuclear Information System (INIS)

    Abd Alrhman, Heba Elyas Khider

    2009-05-01

    This study was conducted in Khartoum state to determine the magnitude of air pollution, resulting from traffic density, due to lead and lead compounds which had been used as additives for gasoline in the form of tetra-ethyl and tetra methyl lead. The level of lead in ambient air and SPM was determined in 14 samples taken randomly at the intersections and entrances to the bridges using personal sampler (Cassella. UK). The mean concentration of suspended particulate matter (SPM) was found to be 5.77+4.04 mg/m 3 . with range between 0.85-12.50 mg/m 3 including three sites above the limit of 10 mg/m 3 allowed. The samples were analyzed with Atomic Absorption Spectrophotometer for their lead content. The average concentration of lead in the sites is found to be 0.1937±0.1768 mg/m 3 . With range between 0.000-0.5166 mg/m 3 . The concentrations in seven sites were above the limit of 0.15 mg/m 3 permitted internationally. The impact of lead pollution on traffic police men was measured by analyzing blood lead concentration of 30 members exposed to traffic air pollution, from the three cities and (10 samples) from non-exposed ( control). It was found to be 2.4601±1.4065μg/100 ml and 0.3944±1.2471 μg/ 100 ml respectively. The data analysis by used SPSS program. There is no significant difference between the two groups. A questionnaire was designed to find out some data about the exposed members including their knowledge of impact, range of age, duration of their service as traffic police, their previous work, and complaints from some of the health effects. The findings were: average age mean of 35.9 ±7.7 years, 47.48% worked for periods of more than 20 years, 74.19% did not work before joining the traffic police, 51.6% of them believe that there is a problem of high level of air pollution, 45.2% medium and 3.2%, pollution is low. As habits 38.71% are smokers. As for health complains, 61.29% have various complains of headaches, fatigue, abdominal, hypertension and anemia

  7. Small scale lithium-lead/water-interaction studies

    International Nuclear Information System (INIS)

    Kranert, O.; Kottowski, H.

    1991-01-01

    One current concept in fusion blanket design is to utilize water as the coolant and liquid lithium-lead as the breeding/neutron multiplier material. Considering the complex design of the blanket module, it is likely that a water leakage into the liquid alloy may occur due to a tube rupture provoking an intolerable pressure increase in the blanket module. The pressure increase is caused by the combined chemical and thermohydraulic reaction of lithium-lead with water. Experiments which simulate such a transient event are necessary to obtain information which is important for the blanket module design. The interaction has been investigated by conducting small-scale experiments at various injection pressures, alloy- and coolant temperatures. Besides using eutectic Li 17 Pb 83 , Li 7 Pb 2 , lithium and lead have been used. Among other results, the experiments indicate increasing chemical reaction with increasing lithium concentration. At the same time, the chemical reaction inhibits violent thermohydaulic reactions due to the attenuating effect of the hydrogen produced. The preliminary epxerimental results from Li 17 Pb 83 and Li 7 Pb 2 reveal that the pressure- and temperature transients caused by the chemical and thermohydraulic reactions lie within technically manageable limits. (orig.)

  8. A synthetic study on constaining a 2D density-dependent saltwater intrusion model using electrical imaging data

    DEFF Research Database (Denmark)

    Antonsson, Arni Valur; Nguyen, Frederic; Engesgaard, Peter Knudegaard

    of the synthetic model, basically a salinity distribution in the coastal aquifer, was converted to resistivity distribution by assuming a certain petrophysical relation between water salinity and electrical conductivity. The obtained resistivity distribution was then used when electrical data acquisition...... was simulated. By applying an advanced inversion approach, electrical images of resistivity were obtained and based on the assumed petrophysical model the salinity distribution was derived. A number of different intrusion simulations were conducted with the aim of assessing the applicability of the method under....... Compared to conventional methods, which only give (few) point information, electrical images can give data over large spatial distances but that can be of great value for groundwater modeling purposes. The aim of this study is to investigate in a synthetic way, the applicability of using electrical images...

  9. Study of different coupling agents in the conjugation of a V3-based synthetic MAP to carrier proteins.

    Science.gov (United States)

    Cruz, L J; Iglesias, E; Aguilar, J C; Quintana, D; Garay, H E; Duarte, C; Reyes, O

    2001-09-01

    The conjugation of synthetic peptides to carrier proteins is a widely used method for immunological studies. Different coupling agents have been described to form the conjugate with carrier proteins. In this paper, we demonstrate that the antibody response toward V3-based synthetic MAPs derived from HIV-1, JY1 isolate, conjugated to two different carrier proteins using either m-maleimidobenzoyl-N-hydroxysuccinimide ester (MBS) or beta-maleimidopropionic acid N-hydroxysuccinimide ester (MPS), or succinic anhydride (SA) show different behaviors. An excellent anti-JY1 response without a strong response to the coupling agent is observed in the case of succinic anhydride spacer. In contrast, MBS produces total abrogation of the antibody response with a high response toward the coupling agent.

  10. Lead isotopic studies of the Samail ophiolite, Oman

    Energy Technology Data Exchange (ETDEWEB)

    Chen, J.H.; Pallister, J.S.

    1981-04-10

    The isotopic composition of Pb and the concentrations of U, Th, and Pb have been determined for samples from various lithologic units and massive sulfides of the Samail ophiolite. The observed /sup 206/Pb//sup 204/Pb ratios range from 17.90 to 19.06, /sup 207/Pb//sup 204/Pb ratios from 15.43 to 15.63, and /sup 208/Pb//sup 204/Pb from 37.66 to 38.78. In Pb isotopic evolution diagrams, the initial Pb isotopic compositions of most of the samples from the Samail ophiolite plot within the field of oceanic basalt, clearly distinct from island arc data, and define some of the least radiogenic Pb observed from oceanic rocks. Lead data from the Samail are compatible with a model involving magma generation from an oceanic mantle source and formation of the ophiolite at an oceanic spreading center. U--Th--Pb isotopic systematics demonstrate that vertical heterogeneity in the oceanic crust can be created through differential concentration of U, Th, and Pb during crystal fractionation and alteration at, or near, the spreading ridge. Calcite form amygdules in the ophiolite basalt has similar Pb isotopic composition to the igneous rocks, suggesting precipitation of the calcite from seawater which contained Pb derived mostly from the oceanic crust. Lead isotopic data on Fe--Cu sulfides are also similar to the results from the igneous suite suggesting that the source of the sulfides is predominently from the oceanic crust. Lead data from serpentinized peridotite and a galena sample from below the ophiolite suggest that part of the serpentinization process and the formation of galena could involve addition of radiogenic Pb from either a continental source or from oceanic sediments.

  11. Lead Exposure: A Summary of Global Studies and the Need for New Studies from Saudi Arabia

    Directory of Open Access Journals (Sweden)

    A. P. Shaik

    2014-01-01

    Full Text Available Lead poisoning (plumbism can cause irreversible genetic and reproductive toxicity, hematological effects, neurological damage, and cardiovascular effects. Despite many efforts to minimize lead poisoning, it continues to be a major health concern in many developing and developed countries. Despite efforts to control lead exposure and toxicity, serious cases of lead poisoning increasingly occur as a result of higher vehicular traffic and industrialization. The biomarkers for identification of genetic susceptibility to a particular disease are useful to identify individuals who are at risk for lead poisoning. Although many such studies have been taken up elsewhere, very few studies were performed in Saudi Arabia to assess susceptibility to lead poisoning. This indicates an urgent need for testing of susceptible individuals. The present paper was planned to understand the genetic susceptibility to lead toxicity in the various population studies conducted worldwide and also to correlate it with the current scenario in Saudi Arabia. Such studies are necessary for appropriate precautions in terms of diet and avoiding exposure to be used in order to prevent adverse health effects.

  12. Mass spectrometric study of thermodynamic properties of gaseous lead tellurates. Estimation of formation enthalpies of gaseous lead polonates

    Energy Technology Data Exchange (ETDEWEB)

    Shugurov, S.M., E-mail: s.shugurov@spbu.ru; Panin, A.I.; Lopatin, S.I.; Emelyanova, K.A.

    2016-10-15

    Gaseous reactions involving lead oxides, tellurium oxide and lead tellurates were studied by the Knudsen effusion mass spectrometry. Equilibrium constants and reaction enthalpies were evaluated. Structures, molecular parameters and thermodynamic functions of gaseous PbTeO{sub 3} and Pb{sub 2}TeO{sub 4} were calculated by quantum chemistry methods. The formation enthalpies Δ{sub f}H{sup 0} (298.15) = −294 ± 13 for gaseous PbTeO{sub 3} and Δ{sub f}H{sup 0} (298.15) = −499 ± 12 for gaseous Pb{sub 2}TeO{sub 4} were obtained. On the base of these results the formation enthalpies of gaseous PbPoO{sub 3} and Pb{sub 2}PoO{sub 4} were estimated as −249 ± 34 and −478 ± 38, respectively. - Highlights: • Gaseous lead tellurates PbTeO{sub 3}, Pb{sub 2}TeO{sub 4} were discovered. • Their thermodynamic properties were studied using both high temperature mass spectrometry and quantum chemistry computations. • The obtained data allows to predict the formation enthalpies of gaseous lead polonates PbPoO{sub 3}, Pb{sub 2}PoO{sub 4}.

  13. Numerical modeling of block structure dynamics: Application to the Vrancea region and study of earthquakes sequences in the synthetic catalogs

    International Nuclear Information System (INIS)

    Soloviev, A.A.; Vorobieva, I.A.

    1995-08-01

    A seismically active region is represented as a system of absolutely rigid blocks divided by infinitely thin plane faults. The interaction of the blocks along the fault planes and with the underlying medium is viscous-elastic. The system of blocks moves as a consequence of prescribed motion of boundary blocks and the underlying medium. When for some part of a fault plane the stress surpasses a certain strength level a stress-drop (''a failure'') occurs. It can cause a failure for other parts of fault planes. The failures are considered as earthquakes. As a result of the numerical simulation a synthetic earthquake catalogue is produced. This procedure is applied for numerical modeling of dynamics of the block structure approximating the tectonic structure of the Vrancea region. By numerical experiments the values of the model parameters were obtained which supplied the synthetic earthquake catalog with the space distribution of epicenters close to the real distribution of the earthquake epicenters in the Vrancea region. The frequency-magnitude relations (Gutenberg-Richter curves) obtained for the synthetic and real catalogs have some common features. The sequences of earthquakes arising in the model are studied for some artificial structures. It is found that ''foreshocks'', ''main shocks'', and ''aftershocks'' could be detected among earthquakes forming the sequences. The features of aftershocks, foreshocks, and catalogs of main shocks are analysed. (author). 5 refs, 12 figs, 16 tabs

  14. Transport of electrons in lead oxide studied by CELIV technique

    International Nuclear Information System (INIS)

    Semeniuk, O; Juska, G; Oelerich, J O; Jandieri, K; Baranovskii, S D; Reznik, A

    2017-01-01

    Although polycrystalline lead oxide (PbO) has a long history of application in optoelectronics and imaging, the transport mechanism for electrons in this material has not yet been clarified. Using the photo-generated charge extraction by linear increasing voltage (photo-CELIV) technique, we provide the temperature- and field-dependences of electron mobility in poly-PbO. It is found that electrons undergo dispersive transport, i.e. their mobility decreases in the course of time. Multiple trapping of electrons from the conduction band into the developed band tail is revealed as the dominant transport mechanism. This differs dramatically from the dispersive transport of holes in the same material, dominated by topological factors and not by energy disorder. (paper)

  15. A parametric study of rate of advance and area coverage rate performance of synthetic aperture radar.

    Energy Technology Data Exchange (ETDEWEB)

    Raynal, Ann Marie [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Hensley, Jr., William H. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Burns, Bryan L. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Doerry, Armin Walter [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2014-11-01

    The linear ground distance per unit time and ground area covered per unit time of producing synthetic aperture radar (SAR) imagery, termed rate of advance (ROA) and area coverage rate (ACR), are important metrics for platform and radar performance in surveillance applications. These metrics depend on many parameters of a SAR system such as wavelength, aircraft velocity, resolution, antenna beamwidth, imaging mode, and geometry. Often the effects of these parameters on rate of advance and area coverage rate are non-linear. This report addresses the impact of different parameter spaces as they relate to rate of advance and area coverage rate performance.

  16. Synthetic Study of 2.5-D ATEM Based on Finite Element Method

    DEFF Research Database (Denmark)

    Qiang, Jianke; Zhou, Junjie; Cai, Hongzhu

    2013-01-01

    be amplified in the process of Laplace transform and Fourier transform. In order to get accurate result, the error should be well controlled in every procedure. The induced electromagnetic force can be computed accurately from vertical magnetic component by applying Lagrange interpolation. The synthetic model...... to the anomalous field which can avoid the singularity problem caused by the source which can excite the anomalous EM field. The EM source can be imposed to our process by incorporate the background EM field. The computation error can be accumulated due to the large variation of EM field and it can also...

  17. Monitoring of aquifer pump tests with Magnetic Resonance Sounding (MRS): a synthetic case study

    DEFF Research Database (Denmark)

    Herckenrath, Daan; Auken, E.; Bauer-Gottwein, Peter

    2011-01-01

    Magnetic Resonance Sounding (MRS) can provide valuable data to constrain and calibrate groundwater flow and transport models. With this non-invasive geophysical technique, measurements of water content and hydraulic conductivity can be obtained. We developed a hydrogeophyiscal forward method, which...... calculates the MRS-signal generated by an aquifer pump test. A synthetic MRS-dataset was subsequently used to determine the hydrogeological parameters in an inverse parameter estimation approach. This was done for a virtual pump test with a partially and a fully penetrating well. With the MRS data we were...

  18. Radiation damage studies on natural and synthetic rock salt utilizing measurements made during electron irradiation

    International Nuclear Information System (INIS)

    Swyler, K.J.; Levy, P.W.

    1977-01-01

    The numerous radiation damage effects which will occur in the rock salt surrounding radioactive waste disposal canisters are being investigated with unique apparatus for making optical and other measurements during 1 to 3 MeV electron irradiation. This equipment, consists of a computer controlled double beam spectrophotometer which simultaneously records 256 point absorption and radioluminescence spectra, in either the 200 to 400 or 400 to 800 nm region, every 40 seconds. Most often the measurements commence as the irradiation is started and continue after it is terminated. This procedure provides information on the kinetics and other details of the damage formation process and, when the irradiation is terminated, on both the transient and stable damage components. The exposure rates may be varied between 10 2 or 10 3 to more than 10 8 rad per hour and the sample temperature maintained between 25 and 800 or 900 0 C. Although this project was started recently, measurements have been made on synthetic NaCl and on natural rock salt from two disposal sites and two mines. Both unstrained and purposely strained samples have been used. Most recently, measurements at temperatures between 25 and 200 0 C have been started. The few measurements completed to date indicate that the damage formation kinetics in natural rock salt are quite different from those observed in synthetic NaCl

  19. High resolution three-dimensional robotic synthetic tracked aperture ultrasound imaging: feasibility study

    Science.gov (United States)

    Zhang, Haichong K.; Fang, Ting Yun; Finocchi, Rodolfo; Boctor, Emad M.

    2017-03-01

    Three dimensional (3D) ultrasound imaging is becoming a standard mode for medical ultrasound diagnoses. Conventional 3D ultrasound imaging is mostly scanned either by using a two dimensional matrix array or by motorizing a one dimensional array in the elevation direction. However, the former system is not widely assessable due to its cost, and the latter one has limited resolution and field-of-view in the elevation axis. Here, we propose a 3D ultrasound imaging system based on the synthetic tracked aperture approach, in which a robotic arm is used to provide accurate tracking and motion. While the ultrasound probe is moved by a robotic arm, each probe position is tracked and can be used to reconstruct a wider field-of-view as there are no physical barriers that restrict the elevational scanning. At the same time, synthetic aperture beamforming provides a better resolution in the elevation axis. To synthesize the elevational information, the single focal point is regarded as the virtual element, and forward and backward delay-andsum are applied to the radio-frequency (RF) data collected through the volume. The concept is experimentally validated using a general ultrasound phantom, and the elevational resolution improvement of 2.54 and 2.13 times was measured at the target depths of 20 mm and 110 mm, respectively.

  20. Inputs and distributions of synthetic musk fragrances in an estuarine and coastal environment; a case study

    Energy Technology Data Exchange (ETDEWEB)

    Sumner, Nicola R. [School of Earth, Ocean and Environmental Science, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL1 3DH (United Kingdom); Guitart, Carlos, E-mail: guitart.carlos@gmail.co [Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL1 3DH (United Kingdom); Fuentes, Gustavo [Instituto Universitario de Tecnologia del Mar (IUTEMAR), Fundacion La Salle de Ciencias Naturales, Margarita Island (Venezuela, Bolivarian Republic of); Readman, James W. [Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL1 3DH (United Kingdom)

    2010-01-15

    Synthetic musks are ubiquitous contaminants in the environment. Compartmental distributions (dissolved, suspended particle associated and sedimentary) of the compounds throughout an axial estuarine transect and in coastal waters are reported. High concentrations of Galaxolide (HHCB) and Tonalide (AHTN) (987-2098 ng/L and 55-159 ng/L, respectively) were encountered in final effluent samples from sewage treatment plants (STPs) discharging into the Tamar and Plym Estuaries (UK), with lower concentrations of Celestolide (ADBI) (4-13 ng/L), Phantolide (AHMI) (6-9 ng/L), musk xylene (MX) (4-7 ng/L) and musk ketone (MK) (18-30 ng/L). Rapid dilution from the outfalls is demonstrated with resulting concentrations of HHCB spanning from 5 to 30 ng/L and those for AHTN from 3 to 15 ng/L. The other musks were generally not detected in the estuarine and coastal waters. The suspended particulate matter (SPM) and sedimentary profiles and compositions (HHCB:AHTN ratios) generally reflect the distribution in the water column with highest concentrations adjacent to sewage outfalls. - Synthetic musks were determined in coastal environmental compartments along an estuarine transect indicating their ubiquitous occurrence in transitional waters.

  1. Inputs and distributions of synthetic musk fragrances in an estuarine and coastal environment; a case study

    International Nuclear Information System (INIS)

    Sumner, Nicola R.; Guitart, Carlos; Fuentes, Gustavo; Readman, James W.

    2010-01-01

    Synthetic musks are ubiquitous contaminants in the environment. Compartmental distributions (dissolved, suspended particle associated and sedimentary) of the compounds throughout an axial estuarine transect and in coastal waters are reported. High concentrations of Galaxolide (HHCB) and Tonalide (AHTN) (987-2098 ng/L and 55-159 ng/L, respectively) were encountered in final effluent samples from sewage treatment plants (STPs) discharging into the Tamar and Plym Estuaries (UK), with lower concentrations of Celestolide (ADBI) (4-13 ng/L), Phantolide (AHMI) (6-9 ng/L), musk xylene (MX) (4-7 ng/L) and musk ketone (MK) (18-30 ng/L). Rapid dilution from the outfalls is demonstrated with resulting concentrations of HHCB spanning from 5 to 30 ng/L and those for AHTN from 3 to 15 ng/L. The other musks were generally not detected in the estuarine and coastal waters. The suspended particulate matter (SPM) and sedimentary profiles and compositions (HHCB:AHTN ratios) generally reflect the distribution in the water column with highest concentrations adjacent to sewage outfalls. - Synthetic musks were determined in coastal environmental compartments along an estuarine transect indicating their ubiquitous occurrence in transitional waters.

  2. A study on the C-peptide radioimmunoassay with synthetized connecting peptide

    International Nuclear Information System (INIS)

    Nakagawa, Shoichi; Sasaki, Takashi; Nakayama, Hidetaka; Watanabe, Takuji; Aoki, Shin

    1976-01-01

    A method of C-peptide radioimmunoassay with the synthetized connecting peptide by Yanaihara was tested for the determination of serum C-peptide immunoreactivity (CPR) in normal people and in diabetics with or without insulin treatment. The CPR value obtained by this method was not interfered with by the presence of serum proteins or by the insulin of people with or without insulin treatment judged by the dilution test and the recovery test. The normal fasting CPR was 2.80 +- 0.78 ng/ml with the synthetized C-peptide as a standard. The CPR value increased and reached a maximum 90 minutes after the ingestion of 50 g of glucose. The increase after the glucose loading reduced corresponding to the severity of diabetes, and some juvenile-onset diabetes showed no response. Adult-type diabetics under insulin treatment, however, showed weak but significant CPR response. The increment of CPR and immunoreactive insulin after glucose loading in normal people and non-treated diabetics was well correlated (γ=0.8262). Judged from the above mentioned results, CPR determination in insulin-treated diabetics was thought to be a useful method for the assessment of the insulin-secreting ability of beta-cells of the pancreas. (J.P.N.)

  3. Study on the C-peptide radioimmunoassay with synthetized connecting peptide

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, S; Sasaki, T; Nakayama, H; Watanabe, T; Aoki, S [Hokkaido Univ., Sapporo (Japan). School of Medicine

    1976-01-01

    A method of C-peptide radioimmunoassay with the synthetized connecting peptide by Yanaihara was tested for the determination of serum C-peptide immunoreactivity (CPR) in normal people and in diabetics with or without insulin treatment. The CPR value obtained by this method was not interfered with by the presence of serum proteins or by the insulin of people with or without insulin treatment judged by the dilution test and the recovery test. The normal fasting CPR was 2.80 +- 0.78 ng/ml with the synthetized C-peptide as a standard. The CPR value increased and reached a maximum 90 minutes after the ingestion of 50 g of glucose. The increase after the glucose loading reduced corresponding to the severity of diabetes, and some juvenile-onset diabetes showed no response. Adult-type diabetics under insulin treatment, however, showed weak but significant CPR response. The increment of CPR and immunoreactive insulin after glucose loading in normal people and non-treated diabetics was well correlated (..gamma..=0.8262). Judged from the above mentioned results, CPR determination in insulin-treated diabetics was thought to be a useful method for the assessment of the insulin-secreting ability of beta-cells of the pancreas.

  4. Open questions in origin of life: experimental studies on the origin of nucleic acids and proteins with specific and functional sequences by a chemical synthetic biology approach

    DEFF Research Database (Denmark)

    Adamala, K.; Anella, F.; Wieczorek, R.

    2014-01-01

    sequences among a vast array of possible ones, the huge "sequence space", leading to the question "why these macromolecules, and not the others?" We have recently addressed these questions by using a chemical synthetic biology approach. In particular, we have tested the catalytic activity of small peptides...

  5. Synthetic observations of molecular clouds in a galactic centre environment - I. Studying maps of column density and integrated intensity

    Science.gov (United States)

    Bertram, Erik; Glover, Simon C. O.; Clark, Paul C.; Ragan, Sarah E.; Klessen, Ralf S.

    2016-02-01

    We run numerical simulations of molecular clouds, adopting properties similar to those found in the central molecular zone (CMZ) of the Milky Way. For this, we employ the moving mesh code AREPO and perform simulations which account for a simplified treatment of time-dependent chemistry and the non-isothermal nature of gas and dust. We perform simulations using an initial density of n0 = 103 cm-3 and a mass of 1.3 × 105 M⊙. Furthermore, we vary the virial parameter, defined as the ratio of kinetic and potential energy, α = Ekin/|Epot|, by adjusting the velocity dispersion. We set it to α = 0.5, 2.0 and 8.0, in order to analyse the impact of the kinetic energy on our results. We account for the extreme conditions in the CMZ and increase both the interstellar radiation field (ISRF) and the cosmic ray flux (CRF) by a factor of 1000 compared to the values found in the solar neighbourhood. We use the radiative transfer code RADMC-3D to compute synthetic images in various diagnostic lines. These are [C II] at 158 μm, [O I] (145 μm), [O I] (63 μm), 12CO (J = 1 → 0) and 13CO (J = 1 → 0) at 2600 and 2720 μm, respectively. When α is large, the turbulence disperses much of the gas in the cloud, reducing its mean density and allowing the ISRF to penetrate more deeply into the cloud's interior. This significantly alters the chemical composition of the cloud, leading to the dissociation of a significant amount of the molecular gas. On the other hand, when α is small, the cloud remains compact, allowing more of the molecular gas to survive. We show that in each case the atomic tracers accurately reflect most of the physical properties of both the H2 and the total gas of the cloud and that they provide a useful alternative to molecular lines when studying the interstellar medium in the CMZ.

  6. Regional-scale geostatistical inverse modeling of North American CO2 fluxes: a synthetic data study

    Directory of Open Access Journals (Sweden)

    A. M. Michalak

    2010-07-01

    Full Text Available A series of synthetic data experiments is performed to investigate the ability of a regional atmospheric inversion to estimate grid-scale CO2 fluxes during the growing season over North America. The inversions are performed within a geostatistical framework without the use of any prior flux estimates or auxiliary variables, in order to focus on the atmospheric constraint provided by the nine towers collecting continuous, calibrated CO2 measurements in 2004. Using synthetic measurements and their associated concentration footprints, flux and model-data mismatch covariance parameters are first optimized, and then fluxes and their uncertainties are estimated at three different temporal resolutions. These temporal resolutions, which include a four-day average, a four-day-average diurnal cycle with 3-hourly increments, and 3-hourly fluxes, are chosen to help assess the impact of temporal aggregation errors on the estimated fluxes and covariance parameters. Estimating fluxes at a temporal resolution that can adjust the diurnal variability is found to be critical both for recovering covariance parameters directly from the atmospheric data, and for inferring accurate ecoregion-scale fluxes. Accounting for both spatial and temporal a priori covariance in the flux distribution is also found to be necessary for recovering accurate a posteriori uncertainty bounds on the estimated fluxes. Overall, the results suggest that even a fairly sparse network of 9 towers collecting continuous CO2 measurements across the continent, used with no auxiliary information or prior estimates of the flux distribution in time or space, can be used to infer relatively accurate monthly ecoregion scale CO2 surface fluxes over North America within estimated uncertainty bounds. Simulated random transport error is shown to decrease the quality of flux estimates in under-constrained areas at the ecoregion scale, although the uncertainty bounds remain realistic. While these synthetic

  7. Rubidium-strontium and uranium-lead isotopic age studies

    International Nuclear Information System (INIS)

    Loveridge, W.D.

    1981-01-01

    The results of five Rb-Sr isotopic age studies predominantly on whole-rock samples, and six U-Pb studies on zircon monazite concentrates are presented. Descriptions of the geological problems and interpretations of the measured ages are included. Laboratory age determination methods and techniques are described or referenced

  8. Natural - synthetic - artificial!

    DEFF Research Database (Denmark)

    Nielsen, Peter E

    2010-01-01

    The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life.......The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life....

  9. A study of the thermal activation of synthetic zeolites (molecular sieve) for gas-solid chromatography

    International Nuclear Information System (INIS)

    Walker, J.A.J.

    1978-10-01

    The thermal activation of synthetic zeolites from two sources has been investigated with reference to the adsorption chromatography of inorganic gases. It was found that the heats of adsorption for oxygen and carbon monoxide increased with activation temperatures. Limits of detection for oxygen in argon and conversely argon in oxygen were determined as well as the chromatographic stability of the activated zeolite. The practical implications and importance of the results are discussed and the application to the analysis of fast reactor blanket gas is mentioned. An explanation is proposed for the adsorption behaviour of these activated materials, based on an electrostatic mechanism, and this has suggested a reason for the separation characteristics of oxygen and argon on polar zeolites. Further work is identified including the investigation of energy states of the oxygen molecule adsorbed on activated zeolite by means of ultra-violet photoelectron spectroscopy. (author)

  10. Polyhydroxyalkanoate-based natural-synthetic hybrid copolymer films: A small-angle neutron scattering study

    International Nuclear Information System (INIS)

    Foster, L. John R.; Knott, Robert; Sanguanchaipaiwong, Vorapat; Holden, Peter J.

    2006-01-01

    Polyhydroxyalkanoates have attracted attention as biodegradable alternatives to conventional thermoplastics and as biomaterials. Through modification of their biosynthesis using Pseudomonas oleovorans, we have manipulated the material properties of these biopolyesters and produced a natural-synthetic hybrid copolymer of polyhydroxyoctanoate-block-diethylene glycol (PHO-b-DEG). A mixture of PHO and PHO-DEG were solvent cast from analytical grade chloroform and analysed using small-angle neutron scattering. A scattering pattern, easily distinguished above the background, was displayed by the films with a diffraction ring at q∼0.12 A -1 . This narrow ring of intensity is suggestive of a highly ordered system. Analysis of the diffraction pattern supported this concept and showed a d-spacing of approximately 50 A. In addition, conformation of the hybrid polymer chains can be manipulated to support their self-assembly into ordered microporous films

  11. A study of the thermal activation of synthetic zeolites (molecular sieve) for gas-solid chromatography

    International Nuclear Information System (INIS)

    Walker, J.A.J.

    1978-10-01

    The thermal activation of synthetic zeolites from two sources has been investigated with reference to the adsorption chromatography of inorganic gases. It was found that the heats of adsorption for oxygen and carbon monoxide increased with activation temperature. Limits of detection for oxygen in argon and conversely argon in oxygen were determined as well as the chromatographic stability of the activated zeolite. The practical implications and importance of the results are discussed and the application to the analysis of fast reactor blanket gas is mentioned. An explanation is proposed for the adsorption behaviour of these activated materials, based on an electrostatic mechanism, and this has suggested a reason for the separation characteristics of oxygen and argon on polar zeolites. Further work is identified including the investigation of energy states of the oxygen molecule adsorbed on activated zeolite by means of ultra-violet photoelectron spectroscopy. (author)

  12. Theoretical Study of Phosphoethanolamine: A Synthetic Anticancer Agent with Broad Antitumor Activity

    Directory of Open Access Journals (Sweden)

    Vitor Prates Lorenzo

    2016-01-01

    Full Text Available Cancer is a major public health problem with limited success of available treatments, pointing to the need for new strategies to be developed. Phosphoethanolamine exhibits broad antitumor activity in a variety of tumor cells and potent inhibitor effects on tumor progress in vivo. Once-used organophosphates inhibit acetylcholinesterase (AChE, resulting in toxic effects to the user. As this group is present in phosphoethanolamine, we perform prediction of the in silico metabolism of phosphoethanolamine and submit this series to a docking study on AChE. A total of 10 metabolites were indicated by the prediction, including ammonia and hydroxylamine, which were not included in the study. Using a group of 8 organophosphorus whose pIC50 values ranged from 5.92 to 9.47 as template, we observed that no compound present in the phosphoethanolamine series had a binding energy lower than that of organophosphorus, suggesting that the series has low inhibitory power on AChE. In light of this, we conclude that phosphoethanolamine and its predicted metabolites do not significantly inhibit AChE to cause a cholinergic crisis. This finding highlights the importance of investigating this compound as lead for potential anticancer agents.

  13. Seismic microzoning from synthetic ground motion parameters: Case study, Santiago de Cuba

    International Nuclear Information System (INIS)

    Alvarez, Leonardo; Vaccari, Franco; Panza, Giuliano F.; Pico, Ramon

    2003-08-01

    Synthetic seismograms (P - SV and SH waves) have been calculated along 6 profiles in Santiago de Cuba basin, with a cutoff frequency of 5 Hz, by using the hybrid approach (modal summation for a regional (ID) structure plus finite differences for a local (2D) structure embedded in the first). They correspond to a scenario earthquake of M S = 7 that may occur in Oriente fault zone, directly south of the city. As initial data for a seismic microzoning, the characterisation of earthquake effects has been made considering several relative (2D/1D) quantities (PGDR, PGVR, PGAR, DGAR, I A R etc.) and functions representative of the ground motion behaviour in soil (2D) with respect to bedrock (ID). The functions are the response spectra ratio RSR(f), already routinely used in this kind of work, and the elastic energy input ratio E I R(f), defined, for the first time, in this paper. These data, sampled at 105 sites within all the profiles have been classified in two steps, using logical combinatory algorithms: connected sets and compact sets. In the first step, from the original ground motion parameters or functions extracted from the synthetic seismograms, 9 sets have been classified and the partial results show the spatial distribution of the soil behaviour as function of the component of motion. In the second step, the results of the classification of the 9 sets have been used as input for a further classification that shows a spatial distribution of sites with a quasi-homogeneous integral ground motion behaviour. By adding the available geological surface data, a microzoning scheme of Santiago de Cuba basin has been obtained. (author)

  14. Infrared spectroscopic study of the synthetic Mg-Ni talc series

    Science.gov (United States)

    Blanchard, Marc; Méheut, Merlin; Delon, Louise; Poirier, Mathilde; Micoud, Pierre; Le Roux, Christophe; Martin, François

    2018-05-01

    Five talc samples [(Mg,Ni)3Si4O10(OH)2] covering the entire Mg-Ni solid solution were synthesized following a recently developed and patented process (Dumas et al., Process for preparing a composition comprising synthetic mineral particles and composition, 2013a; Procédé de préparation d'une composition comprenant des particules minérales synthétiques et composition, 2013b), which produces sub-micron talc particles replying to industrial needs. Near- and mid-infrared spectra were collected and compared to infrared spectra modeled from first-principles calculations based on density functional theory. The good agreement between experimental and theoretical spectra allowed assigning unambiguously all absorption bands. We focused in particular on the four main OH stretching bands, which represent good probes of their local physical and chemical environment. The description of the vibrational modes at the origin of these absorption bands and the theoretical determination of absorption coefficients provide a firm basis for quantifying the talc chemical composition from infrared spectroscopy and for discussing the distribution of divalent cations in the octahedral sheet. Results confirm that these synthetic talc samples have a similar structure as natural talc, with a random distribution of Mg and Ni atoms. They only differ from natural talc by their hydrophilic character, which is due to their large proportion of reactive sites on sheet edges due to sub-micronic size of the particles. Therefore, the contribution on infrared spectra of hydroxyls adsorbed on edge sites has also been investigated by computing the infrared signature of hydroxyls of surface models.

  15. Leading and Managing: A Study of Style and Perception.

    Science.gov (United States)

    Harris, Thomas E.

    A study examined the management style of non-Fortune 500 business leaders and its relationship to their organizations' environment in order to provide a profile of a cross-section of these leaders. The presidents or CEOs of 65 randomly selected Indiana companies with annual sales of at least $5 million were surveyed about situational leadership…

  16. Radiation damage studies on synthetic NaCl crystals and natural rock salt for waste disposal applications

    International Nuclear Information System (INIS)

    Klaffky, R.W.; Swyler, K.J.; Levy, P.W.

    1979-01-01

    Radiation damage studies are being made on synthetic NaCl and natural rock salt crystals from various localities, including potential repository sites. Measurements are being made with equipment for recording the radiation induced F-center and colloid particle absorption bands during irradiation with 1.5 MeV electrons at various temperatures. A technique has been developed to resolve the overlapping F-center and colloid bands. The resulting spectra and curves of absorption vs. dose provide information on colloid particle size and concentration, activation energies for processes occurring during colloid formation, and additional data suggesting that both strain and radiation induced dislocations contribute to the colloid formation process

  17. Structural design study of tritium breeding blanket with a lead layer as a neutron multiplier

    International Nuclear Information System (INIS)

    Iida, Hiromasa; Kitamura, Kazunori; Minato, Akio; Sakamoto, Hiroki; Yamamoto, Takashi

    1980-12-01

    Thermal and structural design study of a tritium breeding blanket with a lead layer for a International Tokamak Reactor (INTOR) is carried out. Tube in shell type blanket with a lead layer is found to be promising. The volume fraction of structural material in the lead layer can be small enough to keep the neutron multiplication effect of lead. Reasonable value of shell effect is attainable due to lead layer in the front part of the blanket. (author)

  18. Conceptual design study of small lead-bismuth cooled reactor

    International Nuclear Information System (INIS)

    Chikazawa, Yoshitaka; Hori, Toru; Kida, Masanori; Konomura, Mamoru

    2004-11-01

    In phase 2 of the feasibility study of commercialized fast reactor cycle systems of JNC, we make a concept of a small sodium cooled reactor for a power source of a city with various requirements, such as, safety and economical competitiveness. various reactor concepts are surveyed and a tank type reactor whose intermediate heat exchanger and primary main pumps are arranged in series is selected. In this study, a compact long life core and a simple reactor structure designs are pursued. The core type is three regional Zr concentration with one Pu enrichment core, the reactor outlet temperature achieves 550degC and the reactor electric output increases from 150 MWe to 165 MWe. The construction cost is much higher than the economical goal in the case of FOAK. But the construction cost in the case of NOAK is estimated to be 85.6% achieving the economical goal. (author)

  19. Leading teams during simulated pediatric emergencies: a pilot study

    Science.gov (United States)

    Coolen, Ester H; Draaisma, Jos M; den Hamer, Sabien; Loeffen, Jan L

    2015-01-01

    Purpose Leadership has been identified as a key variable for the functioning of teams and as one of the main reasons for success or failure of team-based work systems. Pediatricians often function as team leaders in the resuscitation of a critically ill child. However, pediatric residents often report having little opportunity to perform in the role of team leader during residency. In order to gain more insight into leadership skills and behaviors, we classified leadership styles of pediatric residents during simulated emergencies. Methods We conducted a prospective quantitative study to investigate leadership styles used by pediatric residents during simulated emergencies with clinical deterioration of a child at a pediatric ward. Using videotaped scenarios of 48 simulated critical events among 12 residents, we were able to classify verbal and nonverbal communication into different leadership styles according to the situational leadership theory. Results The coaching style (mean 54.5%, SD 7.8) is the most frequently applied by residents, followed by the directing style (mean 35.6%, SD 4.1). This pattern conforms to the task- and role-related requirements in our scenarios and it also conforms to the concept of situational leadership. We did not find any significant differences in leadership style according to the postgraduate year or scenario content. Conclusion The model used in this pilot study helps us to gain a better understanding of the development of effective leadership behavior and supports the applicability of situational leadership theory in training leadership skills during residency. PMID:25610010

  20. Synthetic Brainbows

    KAUST Repository

    Wan, Y.

    2013-06-01

    Brainbow is a genetic engineering technique that randomly colorizes cells. Biological samples processed with this technique and imaged with confocal microscopy have distinctive colors for individual cells. Complex cellular structures can then be easily visualized. However, the complexity of the Brainbow technique limits its applications. In practice, most confocal microscopy scans use different florescence staining with typically at most three distinct cellular structures. These structures are often packed and obscure each other in rendered images making analysis difficult. In this paper, we leverage a process known as GPU framebuffer feedback loops to synthesize Brainbow-like images. In addition, we incorporate ID shuffing and Monte-Carlo sampling into our technique, so that it can be applied to single-channel confocal microscopy data. The synthesized Brainbow images are presented to domain experts with positive feedback. A user survey demonstrates that our synthetic Brainbow technique improves visualizations of volume data with complex structures for biologists.

  1. Synthetic Botany.

    Science.gov (United States)

    Boehm, Christian R; Pollak, Bernardo; Purswani, Nuri; Patron, Nicola; Haseloff, Jim

    2017-07-05

    Plants are attractive platforms for synthetic biology and metabolic engineering. Plants' modular and plastic body plans, capacity for photosynthesis, extensive secondary metabolism, and agronomic systems for large-scale production make them ideal targets for genetic reprogramming. However, efforts in this area have been constrained by slow growth, long life cycles, the requirement for specialized facilities, a paucity of efficient tools for genetic manipulation, and the complexity of multicellularity. There is a need for better experimental and theoretical frameworks to understand the way genetic networks, cellular populations, and tissue-wide physical processes interact at different scales. We highlight new approaches to the DNA-based manipulation of plants and the use of advanced quantitative imaging techniques in simple plant models such as Marchantia polymorpha. These offer the prospects of improved understanding of plant dynamics and new approaches to rational engineering of plant traits. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

  2. The chick embryo: a leading model in somitogenesis studies.

    Science.gov (United States)

    Pourquié, Olivier

    2004-09-01

    The vertebrate body is built on a metameric organization which consists of a repetition of functionally equivalent units, each comprising a vertebra, its associated muscles, peripheral nerves and blood vessels. This periodic pattern is established during embryogenesis by the somitogenesis process. Somites are generated in a rhythmic fashion from the presomitic mesoderm and they subsequently differentiate to give rise to the vertebrae and skeletal muscles of the body. Somitogenesis has been very actively studied in the chick embryo since the 19th century and many of the landmark experiments that led to our current understanding of the vertebrate segmentation process have been performed in this organism. Somite formation involves an oscillator, the segmentation clock whose periodic signal is converted into the periodic array of somite boundaries by a spacing mechanism relying on a traveling threshold of FGF signaling regressing in concert with body axis extension.

  3. Leading teams during simulated pediatric emergencies: a pilot study

    Directory of Open Access Journals (Sweden)

    Coolen EH

    2015-01-01

    Full Text Available Ester H Coolen,1 Jos M Draaisma,2 Sabien den Hamer,3 Jan L Loeffen2 1Department of Pediatric Surgery, Amalia Children’s Hospital, Radboud University Medical Center, 2Department of Pediatrics, Amalia Children’s Hospital, Radboud University Medical Center, 3Department of Communication Science, Radboud University, Nijmegen, the Netherlands Purpose: Leadership has been identified as a key variable for the functioning of teams and as one of the main reasons for success or failure of team-based work systems. Pediatricians often function as team leaders in the resuscitation of a critically ill child. However, pediatric residents often report having little opportunity to perform in the role of team leader during residency. In order to gain more insight into leadership skills and behaviors, we classified leadership styles of pediatric residents during simulated emergencies. Methods: We conducted a prospective quantitative study to investigate leadership styles used by pediatric residents during simulated emergencies with clinical deterioration of a child at a pediatric ward. Using videotaped scenarios of 48 simulated critical events among 12 residents, we were able to classify verbal and nonverbal communication into different leadership styles according to the situational leadership theory. Results: The coaching style (mean 54.5%, SD 7.8 is the most frequently applied by residents, followed by the directing style (mean 35.6%, SD 4.1. This pattern conforms to the task- and role-related requirements in our scenarios and it also conforms to the concept of situational leadership. We did not find any significant differences in leadership style according to the postgraduate year or scenario content. Conclusion: The model used in this pilot study helps us to gain a better understanding of the development of effective leadership behavior and supports the applicability of situational leadership theory in training leadership skills during residency. Keywords

  4. Phase transition in lead titanate thin films: a Brillouin study

    International Nuclear Information System (INIS)

    Kuzel, P; Dugautier, C; Moch, P; Marrec, F Le; Karkut, M G

    2002-01-01

    The elastic properties of both polycrystalline and epitaxial PbTiO 3 (PTO) thin films are studied using Brillouin scattering spectroscopy. The epitaxial PTO films were prepared by pulsed laser ablation on (1) a [0 0 1] single crystal of SrTiO 3 (STO) doped with Nb and (2) a [0 0 1] STO buffered with a layer of YBa 2 Cu 3 O 7 . The polycrystalline PTO films were prepared by sol-gel on a Si substrate buffered with TiO 2 and Pt layers. The data analysis takes into account the ripple and the elasto-optic contributions. The latter significantly affects the measured spectra since it gives rise to a Love mode in the p-s scattering geometry. At room temperature, the spectra of the epitaxially grown samples are interpreted using previously published elastic constants of PTO single crystals. Sol-gel samples exhibit appreciable softening of the effective elastic properties compared to PTO single crystals: this result is explained by taking into account the random orientation of the microscopic PTO grains. For both the polycrystalline and the epitaxial films we have determined that the piezoelectric terms do not contribute to the spectra. The temperature dependence of the spectra shows strong anomalies of the elastic properties near the ferroelectric phase transition. Compared to the bulk, T C is higher in the sol-gel films, while in the epitaxial films the sign of the T C shift depends on the underlying material

  5. Study of core flow distribution for small modular natural circulation lead or lead-alloy cooled fast reactors

    International Nuclear Information System (INIS)

    Chen, Zhao; Zhao, Pengcheng; Zhou, Guangming; Chen, Hongli

    2014-01-01

    Highlights: • A core flow distribution calculation code for natural circulation LFRs was developed. • The comparison study between the channel method and the CFD method was conducted. • The core flow distribution analysis and optimization design for a 10MW natural circulation LFR was conducted. - Abstract: Small modular natural circulation lead or lead-alloy cooled fast reactor (LFR) is a potential candidate for LFR development. It has many attractive advantages such as reduced capital costs and inherent safety. The core flow distribution calculation is an important issue for nuclear reactor design, which will provide important input parameters to thermal-hydraulic analysis and safety analysis. The core flow distribution calculation of a natural circulation LFR is different from that of a forced circulation reactor. In a forced circulation reactor, the core flow distribution can be controlled and adjusted by the pump power and the flow distributor, while in a natural circulation reactor, the core flow distribution is automatically adjusted according to the relationship between the local power and the local resistance feature. In this paper, a non-uniform heated parallel channel flow distribution calculation code was developed and the comparison study between the channel method and the CFD method was carried out to assess the exactness of the developed code. The core flow distribution analysis and optimization design for a 10MW natural circulation LFR was conducted using the developed code. A core flow distribution optimization design scheme for a 10MW natural circulation LFR was proposed according to the optimization analysis results

  6. Study of mechanical properties and fracture mechanisms of synthetic fibers nylon-and-polyester type, used in engineering products

    International Nuclear Information System (INIS)

    Cardoso, Sergio Gomes

    2009-01-01

    Fibers are groups formed by molecular-chain-oriented filaments. Fibers play a fundamental role in human being's daily life and they can be found in several forms and geometries, such as filaments, yarns, beams, rope, fabric, composite, coatings, others. They are used in various segments such as civil, mechanical, electrical, electronics, military, naval, nautical, aviation, health, medicine, environment, communications, safety, space, others. Fibers are divided into two distinct classes: natural and chemical ones, which cover synthetic and man-made sub-classes. They can be produced from several materials, such as wool, cotton, rayon, flax, silk, rock, nylon, polyester, polyethylene, poly-propylene, aramid, glass, carbon, steel, ceramic, others. Globally, the participation of chemical fibers corresponds to approximately 59,9%, and the synthetic fiber polyester, the most used one, represents approximately 63% of the world market. Vital needs have led to the development of multi-function fibers and the focus has changed in the last 10 years with the use of nano technology for environmental responsibility and smart fibers. The study of mechanical properties and fracture mechanisms of fibers is of great relevance for characterization and understanding of causes as consequence of failures. For such reason, it was selected technical fabrics made of high performance synthetic fiber nylon-and-polyester type, used in engineered products such as tires, belts, hoses and pneumatic springs, which have been analyzed in each processing phase. Fiber samples were extracted after each processing phase to be analyzed, by traction destructive tests and scanning electron microscopy. The results of analysis of mechanical properties showed loss of resistance to temperature and multi axial stress during fiber processing phase. Through microscopy tests, it was possible to find contamination, surface stains, plastic deformations, scaling, variations in the fracture faces of the filaments and

  7. In vitro studies of copper release from powder particles in synthetic biological media

    International Nuclear Information System (INIS)

    Midander, Klara; Wallinder, Inger Odnevall; Leygraf, Christofer

    2007-01-01

    The aim of this paper is to provide quantitative data on copper release from powder particles of different copper materials, including artificial copper patina, Cu 2 O and metallic Cu, when exposed to different synthetic biological media to simulate an inhalation scenario and/or skin contact. Generated data may contribute in risk assessment of potential health effects following exposure to and handling of various copper materials. All tests were performed in vitro to determine total copper concentrations, release rates of total copper, and to elucidate its time-dependence. The copper release process was interpreted in terms of specific surface area, surface morphology-, and composition. All powder materials show a time-dependent release process with total copper release rates less than 3 μg/cm 2 per hour at steady state conditions, for all media investigated. The importance of using relevant test media when simulating different interstitial lung conditions and difficulties encountered when comparing powder particles of essentially different properties are thoroughly discussed. - Copper release rates from particles are essential to assess potential health aspects

  8. Synthesis, Characterization and In Vitro Study of Synthetic and Bovine-Derived Hydroxyapatite Ceramics: A Comparison

    Directory of Open Access Journals (Sweden)

    July Andrea Rincón-López

    2018-02-01

    Full Text Available The physicochemical properties and biological behavior of sintered-bovine-derived hydroxyapatite (BHAp are here reported and compared to commercial synthetic-HAp (CHAp. Dense ceramics were sintered for 2 h and 4 h at 1200 °C to investigate their microstructure–structure–in-vitro behavior relationship for both HAp ceramics. Densification was directly proportional to sintering time, showing a grain coarsening behavior with a greater effect on BHAp. Lattice parameters, crystallite size, cell volume and Ca/P ratio were determined by Rietveld refinement of X-ray diffraction (XRD patterns using GSAS®. Ionic substitutions (Na+, Mg2+, CO32− related to BHAp structure were associated with their position changes in the vibrational modes and correlated with the structural parameters obtained from the XRD analysis. Variations in the structural parameters and surface morphology were also evaluated after different soaking periods in simulated body fluid, which is associated with the formation of bone-like apatite layer and thus bioactivity. Mitochondrial activity (MTS and lactate dehydrogenase (LDH assays showed that the material released by the ceramics does not induce toxicity after exposure in human fetal osteoblastic (hFOB cells. Furthermore, no statistically significant differences were found between the HAp obtained from different sources. These results show that BHAp can be used with no restrictions for the same biomedical applications as CHAp.

  9. Understanding reactivity of two newly synthetized imidazole derivatives by spectroscopic characterization and computational study

    Science.gov (United States)

    Hossain, Mossaraf; Thomas, Renjith; Mary, Y. Sheena; Resmi, K. S.; Armaković, Stevan; Armaković, Sanja J.; Nanda, Ashis Kumar; Vijayakumar, G.; Van Alsenoy, C.

    2018-04-01

    Two newly synthetized imidazole derivatives (1-(4-methoxyphenyl)-4,5-dimethyl-1H-imidazole-2-yl acetate (MPDIA) and 1-(4-bromophenyl)-4,5-dimethyl-1H-imidazole-2-yl acetate (BPDIA)) have been prepared by solvent-free synthesis pathway and their specific spectroscopic and reactive properties have been discussed based on combined experimental and computational approaches. Aside of synthesis, experimental part of this work included measurements of IR, FT-Raman and NMR spectra. All of the aforementioned spectra were also obtained computationally, within the framework of density functional theory (DFT) approach. Additionally, DFT calculations have been used in order to investigate local reactivity properties based on molecular orbital theory, molecular electrostatic potential (MEP), average local ionization energy (ALIE), Fukui functions and bond dissociation energy (BDE). Molecular dynamics (MD) simulations have been used in order to obtain radial distribution functions (RDF), which were used for identification of the atoms with pronounced interactions with water molecules. MEP showed negative regions are mainly localized over N28, O29, O35 atoms, it is represent with red colour in rainbow color scheme for MPDIA and BPDIA (which are most reactive sites for electrophilic attack). The first order hyperpolarizabilities of MPDIA and BPDIA are 20.15 and 6.10 times that of the standard NLO material urea. Potential interaction with antihypertensive protein hydrolase.

  10. Seismic microzoning from synthetic ground motion parameters Case study, Santiago de Cuba

    CERN Document Server

    Alvarez, L; Pico, R; Vaccari, F

    2003-01-01

    Synthetic seismograms (P - SV and SH waves) have been calculated along 6 profiles in Santiago de Cuba basin, with a cutoff frequency of 5 Hz, by using the hybrid approach (modal summation for a regional (ID) structure plus finite differences for a local (2D) structure embedded in the first). They correspond to a scenario earthquake of M sub S = 7 that may occur in Oriente fault zone, directly south of the city. As initial data for a seismic microzoning, the characterisation of earthquake effects has been made considering several relative (2D/1D) quantities (PGDR, PGVR, PGAR, DGAR, I sub A R etc.) and functions representative of the ground motion behaviour in soil (2D) with respect to bedrock (ID). The functions are the response spectra ratio RSR(f), already routinely used in this kind of work, and the elastic energy input ratio E sub I R(f), defined, for the first time, in this paper. These data, sampled at 105 sites within all the profiles have been classified in two steps, using logical combinatory algorith...

  11. Removal of zearalenone toxin from synthetics gastric and body fluids using talc and diatomite: a batch kinetic study.

    Science.gov (United States)

    Sprynskyy, Myroslav; Gadzała-Kopciuch, Renata; Nowak, Karolina; Buszewski, Bogusław

    2012-06-01

    Adsorption kinetics of zearalenone (ZEA) toxin from synthetic gastric fluid (SGF) and synthetic body fluid (SBF) by talc and diatomite was studied in the batch experiments. Chemical composition, morphology and structure of the used adsorbents were examined by scanning electron microscopy, FTIR spectroscopy and low-temperature nitrogen adsorption/desorption method. High performance liquid chromatography (HPLC) method was used for ZEA determining. The study results showed that ZEA is more effectively adsorbed on the talc (73% and 54% from SGF and SBF respectively). The efficiency on the diatomite was lower (53% and 42% from SGF and SBF respectively). The first order kinetics model was applied to describe the adsorption process. Rate of the ZEA adsorption from SGF is very rapid initially with about 95% of amount of the toxin adsorbed during first 5 min, while ZEA is adsorbed from SBF in two steps. The values of determined Gibbs free energy of adsorption (from -13 to -17 kJ/mol) indicated that adsorption of ZEA toxin by the both adsorbents are spontaneous and exothermic. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Building synthetic cellular organization

    OpenAIRE

    Polka, Jessica K.; Silver, Pamela A.

    2013-01-01

    The elaborate spatial organization of cells enhances, restricts, and regulates protein–protein interactions. However, the biological significance of this organization has been difficult to study without ways of directly perturbing it. We highlight synthetic biology tools for engineering novel cellular organization, describing how they have been, and can be, used to advance cell biology.

  13. Synthetic Metabolic Pathways

    DEFF Research Database (Denmark)

    topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Authoritative and practical, Synthetic Metabolic Pathways: Methods and Protocols aims to ensure successful results in the further study...

  14. Experimental study and calculations of the near critical behavior of a synthetic fluid in nitrogen injection

    International Nuclear Information System (INIS)

    Coronado Parra, Carlos Alberto; Escobar Remolina, Juan Carlos M

    2005-01-01

    In recent years, the use of nitrogen has increased as gas injection to recover oil fluids near the critical point. The behavior of hydrocarbon mixture phases in the critical region shows very interesting complex phenomena when facing a recovery project with nitrogen. Therefore, it is important to have experimental information of the PVTx thermodynamic variable, often scarce, for this type of critical phenomena. This paper reports the experimental measures of the volumetric behavior and phases of synthetic fluid in a nitrogen injection process. The experiment was performed at laboratory scale, and it obtained variations on the saturation pressure, gas oil ratio, density and composition of the hydrocarbon phase when nitrogen was injected at molars of 10,20,30 and 40% on different volumetric portions of the mother sample. In addition, the data obtained experimentally was used to demonstrate the capacity of tune to compositional models. The data provided represents a valuable contribution to the understanding of phenomena associated with retrograde and near critical regions, as well as their use in tuning and developing more elaborate models such as Cubic Equations of State (EOS). It is worth highlighting the importance of this data in the potential processes of nitrogen, CO 2 , and lean gas injection, which require knowledge of the gas-oil ratio, saturation pressures, density and composition of the fluid in current production. The identification of the phenomena shown, represent a potential application to the modeling of displacements and maintaining the pressure in the improved recovery when scaling up the laboratory data to the field / reservoir conditions

  15. Synthetic Astrobiology

    Science.gov (United States)

    Rothschild, Lynn J.

    2017-01-01

    "Are we alone?" is one of the primary questions of astrobiology, and whose answer defines our significance in the universe. Unfortunately, this quest is hindered by the fact that we have only one confirmed example of life, that of earth. While this is enormously helpful in helping to define the minimum envelope for life, it strains credulity to imagine that life, if it arose multiple times, has not taken other routes. To help fill this gap, our lab has begun using synthetic biology - the design and construction of new biological parts and systems and the redesign of existing ones for useful purposes - as an enabling technology. One theme, the "Hell Cell" project, focuses on creating artificial extremophiles in order to push the limits for Earth life, and to understand how difficult it is for life to evolve into extreme niches. In another project, we are re-evolving biotic functions using only the most thermodynamically stable amino acids in order to understand potential capabilities of an early organism with a limited repertoire of amino acids.

  16. Do US Ambient Air Lead Levels Have a Significant Impact on Childhood Blood Lead Levels: Results of a National Study

    Directory of Open Access Journals (Sweden)

    LuAnn L. Brink

    2013-01-01

    Full Text Available Introduction. Although lead paint and leaded gasoline have not been used in the US for thirty years, thousands of US children continue to have blood lead levels (BLLs of concern. Methods. We investigated the potential association of modeled air lead levels and BLLs ≥ 10 μg/dL using a large CDC database with BLLs on children aged 0–3 years. Percent of children with BLLs ≥ 10 μg/dL (2000–2007 by county and proportion of pre-50 housing and SES variables were merged with the US EPA's National Air Toxics Assessment (NATA modeled air lead data. Results. The proportion with BLL ≥ 10 μg/dL was 1.24% in the highest air lead counties, and the proportion with BLL ≥ 10 μg/dL was 0.36% in the lowest air lead counties, resulting in a crude prevalence ratio of 3.4. Further analysis using multivariate negative binomial regression revealed that NATA lead was a significant predictor of % BLL ≥ 10 μg/dL after controlling for percent pre-l950 housing, percent rural, and percent black. A geospatial regression revealed that air lead, percent older housing, and poverty were all significant predictors of % BLL ≥ 10 μg/dL. Conclusions. More emphasis should be given to potential sources of ambient air lead near residential areas.

  17. Novel studies of molecular orientation in synthetic polymeric membranes for gas separation

    International Nuclear Information System (INIS)

    Ismail, Ahmad Fauzi

    1998-01-01

    The main objective of this investigation was to produce a super-selective asymmetric membrane for gas separation. To achieve this, molecular orientation induced by rheological conditions during membrane fabrication was investigated and related to the gas separation performance of flat sheet and hollow fiber membranes. Infrared dichroism, a spectroscopic technique, was developed in the first phase of the research to directly measure molecular orientation in flat sheet membranes. The degree of molecular orientation was found to increase with increasing shear during fabrication which enhanced both pressure-normalised flux and selectivity of the coated membranes. The rheology of polymer solutions and the mechanism of molecular orientation have been treated in detail for membrane production. This is a novel approach since previous fundamental work has focused on the phase inversion process. The current study showed that rheological conditions during membrane fabrication have the utmost importance in enhancing membrane selectivity. The effects of molecular orientation at greater shear, as experienced by hollow fiber membranes during extrusion through the spinneret channel, were investigated in the second phase of this research. In order to produce a good quality fiber, a unique tube-in-orifice spinneret and a modified hollow fiber spinning rig were designed and fabricated. Thus the combined effects of reduced water activity in the bore coagulant during hollow fiber spinning and rheologically induced molecular orientation were investigated. The selectivity of the coated high shear hollow fiber membranes was heightened and even surpassed the recognised intrinsic selectivity of the polymer. Pressure-normalised flux also increased with increasing shear rate. In the third phase of this research phase inversion conditions were further optimised to give a superior skin layer and thus provide an even better platform for the advantageous effects of molecular orientation. These

  18. More evidence of unpublished industry studies of lead smelter/refinery workers

    Science.gov (United States)

    2015-01-01

    Background Lead smelter/refinery workers in the US have had significant exposure to lead and are an important occupational group to study to understand the health effects of chronic lead exposure in adults. Recent research found evidence that studies of lead smelter/refinery workers have been conducted but not published. This paper presents further evidence for this contention. Objectives To present further evidence of industry conducted, unpublished epidemiologic studies of lead smelter/refinery workers and health outcomes. Methods Historical research relying on primary sources such as internal industry documents and published studies. Results ASARCO smelter/refinery workers were studied in the early 1980s and found to have increased risk of lung cancer and stroke in one study, but not in another. Conclusions Because occupational lead exposure is an on-going concern for US and overseas workers, all epidemiologic studies should be made available to evaluate and update occupational health and safety standards. PMID:26070220

  19. Slurry growth, gas retention, and flammable gas generation by Hanford radioactive waste tanks: Synthetic waste studies, FY 1991

    International Nuclear Information System (INIS)

    Bryan, S.A.; Pederson, L.R.; Ryan, J.L.; Scheele, R.D.; Tingey, J.M.

    1992-08-01

    Of 177 high-level waste storage tanks on the Hanford Site, 23 have been placed on a safety watch list because they are suspected of producing flammable gases in flammable or explosive concentrate. One tankin particular, Tank 241-SY-101 (Tank 101-SY), has exhibited slow increases in waste volume followed by a rapid decrease accompanied by venting of large quantities of gases. The purpose of this study is to help determine the processes by which flammable gases are produced, retained, and eventually released from Tank 101-SY. Waste composition data for single- and double-shell waste tanks on the flammable gas watch listare critically reviewed. The results of laboratory studies using synthetic double-shell wastes are summarized, including physical and chemical properties of crusts that are formed, the stoichiometry and rate ofgas generation, and mechanisms responsible for formation of a floating crust

  20. A study on synthetic method and material characteristics of magnesium ammine chloride as ammonia transport materials for solid SCR

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jong Kook; Yoon, Cheon Seog [Dept. of Mechanical Engineering, Hannam University, Daejeon (Korea, Republic of); Kim, Hong Suk [Engine Research Center, Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

    2015-11-15

    Among various ammonium salts and metal ammine chlorides used as solid materials for the sources of ammonia with solid SCR for lean NOx reduction, magnesium ammine chloride was taken up for study in this paper because of its ease of handling and safety. Lab-scale synthetic method of magnesium ammine chloride were studied for different durations, temperatures, and pressures with proper ammonia gas charged, as a respect of ammonia gas adsorption rate(%). To understand material characteristics for lab-made magnesium ammine chloride, DA, IC, FT-IR, XRD and SDT analyses were performed using the published data available in literature. From the analytical results, the water content in the lab-made magnesium ammine chloride can be determined. A new test procedure for water removal was proposed, by which the adsorption rate of lab-made sample was found to be approximately 100%.

  1. A study on synthetic method and material characteristics of magnesium ammine chloride as ammonia transport materials for solid SCR

    International Nuclear Information System (INIS)

    Shin, Jong Kook; Yoon, Cheon Seog; Kim, Hong Suk

    2015-01-01

    Among various ammonium salts and metal ammine chlorides used as solid materials for the sources of ammonia with solid SCR for lean NOx reduction, magnesium ammine chloride was taken up for study in this paper because of its ease of handling and safety. Lab-scale synthetic method of magnesium ammine chloride were studied for different durations, temperatures, and pressures with proper ammonia gas charged, as a respect of ammonia gas adsorption rate(%). To understand material characteristics for lab-made magnesium ammine chloride, DA, IC, FT-IR, XRD and SDT analyses were performed using the published data available in literature. From the analytical results, the water content in the lab-made magnesium ammine chloride can be determined. A new test procedure for water removal was proposed, by which the adsorption rate of lab-made sample was found to be approximately 100%

  2. Ga(III) chelates of amphiphilic DOTA-based ligands: synthetic route and in vitro and in vivo studies

    International Nuclear Information System (INIS)

    Fontes, Andre; Prata, M. Isabel M.; Geraldes, Carlos F.G.C.; Andre, Joao P.

    2011-01-01

    In this work, we report on a synthetic strategy using amphiphilic DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid)-based chelators bearing a variable-sized α-alkyl chain at one of the pendant acetate arms (from 6 to 14 carbon atoms), compatible with their covalent coupling to amine-bearing biomolecules. The amphiphilic behavior of the micelles-forming Ga(III) chelates (critical micellar concentration), their stability in blood serum and their lipophilicity (logP) were investigated. Biodistribution studies with the 67 Ga-labeled chelates were performed in Wistar rats, which showed a predominant liver uptake with almost no traces of the radiochelates in the body after 24 h.

  3. High-pressure optical spectroscopy and X-ray diffraction studies on synthetic cobalt aluminum silicate garnet

    DEFF Research Database (Denmark)

    N. Taran, Michail; Nestola, Fabrizio; Ohashi, Haruo

    2007-01-01

    The pressure-induced behavior of spin-allowed dd-bands of VIIICo2+ in the absorption spectra of synthetic Co3Al2Si3O12 garnet was studied from 10-4 to 13 GPa. The plots of the peak energy vs. pressure for the three sharpest well resolved bands at ca. 5160, 17 680, and 18 740 cm-1 display small...... but discernible breaks in linear relations between 4 and 5 GPa. Datafromsingle-crystalX-raydiffractionData from single-crystal X-ray diffraction likewise show discontinuities in trends of CoO8 polyhedral volume and distortion, and Co-O and Si-O bond distances over this pressure range. These effects are related...... to a pressure-induced phase transition from the ß- to a-isostructural polymorph of Co3Al2Si3O12....

  4. Ga(III) chelates of amphiphilic DOTA-based ligands: synthetic route and in vitro and in vivo studies

    Energy Technology Data Exchange (ETDEWEB)

    Fontes, Andre [Centro de Quimica, Campus de Gualtar, Universidade do Minho, 4710-057, Braga (Portugal); Prata, M. Isabel M. [IBILI, Faculdade de Medicina, Universidade de Coimbra, 3548, Coimbra (Portugal); Geraldes, Carlos F.G.C. [Departamento de Ciencias da Vida, Faculdade de Ciencias e Tecnologia, Universidade de Coimbra, 3001-401, Coimbra (Portugal); Centro de Neurociencias e Biologia Celular, Universidade de Coimbra, 3001-401, Coimbra (Portugal); Andre, Joao P., E-mail: jandre@quimica.uminho.p [Centro de Quimica, Campus de Gualtar, Universidade do Minho, 4710-057, Braga (Portugal)

    2011-04-15

    In this work, we report on a synthetic strategy using amphiphilic DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid)-based chelators bearing a variable-sized {alpha}-alkyl chain at one of the pendant acetate arms (from 6 to 14 carbon atoms), compatible with their covalent coupling to amine-bearing biomolecules. The amphiphilic behavior of the micelles-forming Ga(III) chelates (critical micellar concentration), their stability in blood serum and their lipophilicity (logP) were investigated. Biodistribution studies with the {sup 67}Ga-labeled chelates were performed in Wistar rats, which showed a predominant liver uptake with almost no traces of the radiochelates in the body after 24 h.

  5. [Diversity of Plants Belonging to the Genus Ligularia (Asteraceae) Based on Terpenoids and Synthetic Studies on Some Terpenoids].

    Science.gov (United States)

    Tori, Motoo

    2016-01-01

    The terpenoid constituents of Ligularia virgaurea (30 samples), Ligularia pleurocaulis (8 samples), Ligularia dictyoneura (8 samples), Ligularia brassicoides (5 samples), Ligularia lingiana (1 sample), and Ligularia liatroides (1 sample)(all belonging to section Senecillis of Ligularia, Asteraceae and collected in Yunnan, Sichuan, Qinghai, and Gansu provinces, China), from which 220 compounds were isolated, including 113 novel ones, are reviewed. Five chemotypes were identified in L. virgaurea based on their chemical constituents, while three clades were detected from the base sequences. Although intra-specific diversity was found in L. virgaurea, more samples were needed of other species in order to reach a definite conclusion. Inter-specific diversity was also examined in section Senecillis but was restricted due to the scarcity of samples. Synthetic studies on chiral natural products to determine their absolute configurations, especially those of riccardiphenols A and B as well as crispatanolide, which were all isolated from the liverwort, are briefly reviewed.

  6. What can robots tell us about brains? A synthetic approach towards the study of learning and problem solving.

    Science.gov (United States)

    Voegtlin, T; Verschure, P F

    1999-01-01

    This paper argues for the development of synthetic approaches towards the study of brain and behavior as a complement to the more traditional empirical mode of research. As an example we present our own work on learning and problem solving which relates to the behavioral paradigms of classical and operant conditioning. We define the concept of learning in the context of behavior and lay out the basic methodological requirements a model needs to satisfy, which includes evaluations using robots. In addition, we define a number of design principles neuronal models should obey to be considered relevant. We present in detail the construction of a neural model of short- and long-term memory which can be applied to an artificial behaving system. The presented model (DAC4) provides a novel self-consistent implementation of these processes, which satisfies our principles. This model will be interpreted towards the present understanding of the neuronal substrate of memory.

  7. Vectoring of parallel synthetic jets

    Science.gov (United States)

    Berk, Tim; Ganapathisubramani, Bharathram; Gomit, Guillaume

    2015-11-01

    A pair of parallel synthetic jets can be vectored by applying a phase difference between the two driving signals. The resulting jet can be merged or bifurcated and either vectored towards the actuator leading in phase or the actuator lagging in phase. In the present study, the influence of phase difference and Strouhal number on the vectoring behaviour is examined experimentally. Phase-locked vorticity fields, measured using Particle Image Velocimetry (PIV), are used to track vortex pairs. The physical mechanisms that explain the diversity in vectoring behaviour are observed based on the vortex trajectories. For a fixed phase difference, the vectoring behaviour is shown to be primarily influenced by pinch-off time of vortex rings generated by the synthetic jets. Beyond a certain formation number, the pinch-off timescale becomes invariant. In this region, the vectoring behaviour is determined by the distance between subsequent vortex rings. We acknowledge the financial support from the European Research Council (ERC grant agreement no. 277472).

  8. Ultrastructural study of liver and lead tissue concentrations in young mallard ducks (Anas platyrhynchos) after ingestion of single lead shot.

    Science.gov (United States)

    Pineau, Alain; Fauconneau, Bernard; Plouzeau, Eric; Fernandez, Béatrice; Quellard, Nathalie; Levillain, Pierre; Guillard, Olivier

    2017-01-01

    Lead (Pb) represents a serious threat to wildlife and ecosystems. The aim of this study was to examine the subcellular effects of dietary Pb pellet ingestion on mallard (Anas platyrhynchos) livers. After ingestion of a single Pb shot (LS4 size class: 0.177 ± 0.03 g) in 41 mallard ducks (22 males and 19 females) versus 10 controls (5 males and 5 females), all 7-week old, a morphologic study was conducted by TEM (transmission electron microscopy) of liver at the subcellular level. The results in treated mallards showed at a magnification of 2500 X that hepatic parenchyma was altered as evidenced by intralysosomal electron-dense deposits, which are compatible with Pb deposits. Further, at a higher magnification (15,000 X) in both genders, deterioration of mitochondria was observed in which the crests and, to a lesser extent, outer membrane were lysed. While the rough endoplasmic reticulum was fragmented, intracytoplasmic electron-dense material compatible with Pb deposits was maximally visible, thereby underscoring the deeply destructive effect of this metal on the subcellular architecture of the liver. In addition, applying an optimized and validated method in a clean room using electrothermal atomic absorption spectrophotometer (ETAAS) with Zeeman background correction, the objective was to improve and refine certain indispensable measurements pertaining to Pb impregnation in tissues other than liver such as kidneys, bones, and feathers of mallards. Data demonstrated show that compared with controls, Pb accumulation increases significantly, not only in the liver (3-fold), but also in the bones and the feathers (14-fold). No significant difference was noted between males and females. Bearing in mind the marked subcellular toxicity attributed to Pb, this study reinforces present-day arguments advocating limitation of game consumption.

  9. [Ridge preservation with synthetic nanocrystalline hydroxyapatite reduces the severity of gingival invaginations-a prospective clinical study].

    Science.gov (United States)

    Reichert, Christoph; Wenghoefer, Matthias; Kutschera, Eric; Götz, Werner; Jäger, Andreas

    2014-01-01

    Gingival invaginations develop after tooth extraction and subsequent orthodontic space closure. Aetiological factors and long-term effects of gingival invaginations on oral health are nearly unknown. In addition, preventive or therapeutic strategies are rare. This prospective clinical study employing the split mouth technique was performed to investigate the effect of extraction socket augmentation with a synthetic nanocrystalline hydroxyapatite (NanoBone(®) Artoss, Rostock, Germany) on the incidence and degree of gingival invaginations. A total of 10 orthodontic patients with need for symmetric premolar extractions offering a total of 28 extractions were included in this trial. The study plan provided one extraction site to be augmented with synthetic nanocrystalline hydroxyapatite (NanoBone(®)), the other served as control. After primary wound healing, space closure was performed under defined biomechanical conditions. After space closure was accomplished, occurrence and degree of gingival invaginations as well as probing depths of the adjacent teeth mesial and distal to the extractions were determined and dental radiographs were taken. The degree of gingival invaginations and probing depths mesial and distal of the extraction were significantly reduced on NanoBone(®) augmented extraction sites. In addition, 70% of the radiographs revealed translucent and hyperdense areas on the intervention side after space closure. Apical root resorption was found in 2 patients on both the NanoBone(®) side and the control side. Ridge preservation with NanoBone(®) appeared to reduce the severity of gingival invaginations. Further investigation on long-term effects is mandatory to eliminate the appearance of adverse effects.

  10. BIOACCUMULATION AND DEPURATION STUDIES OF LEAD NITRATE ON ECONOMICALLY IMPORTANT SHRIMP PENAEOUS MONODON

    OpenAIRE

    S.Palani Kumar; A.S.Sharadhamma

    2013-01-01

    Current study of Bioaccumulation and Depuration of Lead nitrate on marine shrimp Penaeous monodon shows Lead nitrate accumulation more in hepatopancreas compared to muscle and the depuration level of heavy metal Lead nitrate was more through hepatopancreas comparing to muscle tissues, when comparing to the control animals.This shows the major role of Hepatopacreas in Bioaccumulation and depuration in this study on muscle tissues and hepatopancreas tissues

  11. Synthetic Studies Towards the Core Structure of Nakadomarin A by a Thioamide-Based Strategy

    Science.gov (United States)

    Chavda, Jai K; Procopiou, Panayiotis A; Horton, Peter N; Coles, Simon J; Porter, Michael J

    2014-01-01

    The tricyclic BCD substructure of the marine natural product nakadomarin A has been synthesised. The strategy utilised a key carbon–carbon bond-forming reaction between a furan and an N-acyliminium ion derived from a secondary thiolactam. In addition, a novel three-component coupling reaction between a thioamide, an allylic bromide and an isocyanate, leading to the establishment of two new stereogenic centres, is reported. Two key steps in a projected total synthesis of nakadomarin A have been realised by using the unique chemistry of thioamides. Formation of the carbocyclic B ring can be effected by nucleophilic attack of a furan on a thiolactam-derived iminium ion, and the key quaternary centre can be established by a novel three-component coupling reaction. PMID:24829538

  12. Comparative study of measured heart cycle phase durations: standard lead ECG versus original ascending aorta lead ECG

    Directory of Open Access Journals (Sweden)

    Sergey V. Kolmakov

    2012-11-01

    Full Text Available Aims The present paper aims at evaluating the existing difference in duration measurements of the same heart cycle phases in the standard V3, V4, V5, V6 leads ECG versus original HDA lead ECG of the ascending aorta. Materials and methods The method of changing the filter pass band is used. Its essence is in artificial changing of the conditions of the signal recording carrying the informative indications of the initial information used in hemodynamic equations. The method also enables calculating the percentage deviation from the initial values. The principle of balance of the blood volume entering the heart and the blood volume leaving the heart is used to trace the minimal deviations and their respective recording conditions. Results In each of the V3, V4, V5, V6 ECG leads durations of the same phases have different values. The values measured on the ECG of the ascending aorta and those measured using the standard V4 ECG lead differ slightly. Conclusion For heart cycle phase analysis it is possible to use only the ECG of the ascending aorta and V4 standard lead ECG. Using conventional standard ECG leads causes an error up to 25%.

  13. Synthetic Molecular Machines for Active Self-Assembly: Prototype Algorithms, Designs, and Experimental Study

    Science.gov (United States)

    Dabby, Nadine L.

    behaviors. This class of behaviors includes any behavior where a passive physical system simply does not have enough physical energy to perform the specified tasks in the requisite amount of time. As we will demonstrate and prove, a sufficiently expressive implementation of an "active" molecular self-assembly approach can achieve these behaviors. Using an external source of fuel solves part of the problem, so the system is not "energetically incomplete." But the programmable system also needs to have sufficient expressive power to achieve the specified behaviors. Perhaps surprisingly, some of these systems do not even require Turing completeness to be sufficiently expressive. Building on a large variety of work by other scientists in the fields of DNA nanotechnology, chemistry and reconfigurable robotics, this thesis introduces several research contributions in the context of active self-assembly. We show that simple primitives such as insertion and deletion are able to generate complex and interesting results such as the growth of a linear polymer in logarithmic time and the ability of a linear polymer to treadmill. To this end we developed a formal model for active-self assembly that is directly implementable with DNA molecules. We show that this model is computationally equivalent to a machine capable of producing strings that are stronger than regular languages and, at most, as strong as context-free grammars. This is a great advance in the theory of active self-assembly as prior models were either entirely theoretical or only implementable in the context of macro-scale robotics. We developed a chain reaction method for the autonomous exponential growth of a linear DNA polymer. Our method is based on the insertion of molecules into the assembly, which generates two new insertion sites for every initial one employed. The building of a line in logarithmic time is a first step toward building a shape in logarithmic time. We demonstrate the first construction of a synthetic

  14. Integrating CHWs as part of the team leading diabetes group visits: A randomized controlled feasibility study

    Science.gov (United States)

    The purpose of the study was to evaluate the feasibility of integrating Community Health Workers (CHWs) as part of the team leading diabetes group visits. This was a randomized controlled study that integrated CHWs as part of the team leading diabetes group visits for low-income Hispanic adults (n=5...

  15. [Isolation, identification and lead adsorption study of lead-resistant Lactobacillus casei strains from feces of healthy newborns].

    Science.gov (United States)

    Shen, Wei; Yu, Qin-Fei; Wang, Yu-Hao; Zhang, Yi-Duo; Meng, Xiao-Jing; Fan, Hong-Ying

    2016-12-20

    To isolate and identify lead-resistant Lactobacillus casei strains with lead adsorption ability from the stool of healthy newborns as a new source of bacteria for developing lead-eliminating food products. MRS was used to isolate lead-resistant bacteria from the feces of 30 healthy and full-term neonates. A phylogenetic tree was constructed based on the morphological characteristics and 16S rRNA sequences of the isolated bacteria. Physiological and biochemical characterizations of the bacteria were performed according to the Berger's Systematic Bacteriology Handbook, followed by antimicrobial susceptibility test and acid-tolerant bile salt test. The adsorption capacity of Pb 2+ of the bacteria was determined by inductively coupled plasma-optical emission spectroscopy (ICP-OES). Three strains of Lactobacillus casei were isolated, which were resistant to penicillin and ceftriaxone and could tolerate the exposure to 500 mg/L Pb 2+ . Acid-tolerant bile salt test showed that the bacteria were resistant to culture in the presence of artificial gastric juice (pH 2.0) for 3 h, and their survival rate reached 62.5% following exposure to 0.3% bile salt for 8 h. The bacteria showed a Pb 2+ adsorption rate of 90.4% at a low Pb 2+ concentration (1 mg/L) and of 86.27% at a high Pb 2+ concentration (50 mg/L). Three Lactobacillus casei strains lead adsorption ability were isolated from the feces of newborns. These bacterial strains provide a new solution to alleviate lead poisoning by probiotic dietary.

  16. Direct interaction of natural and synthetic catechins with signal transducer activator of transcription 1 affects both its phosphorylation and activity

    KAUST Repository

    Menegazzi, Marta; Mariotto, Sofia; Dal Bosco, Martina; Darra, Elena; Vaiana, Nadia; Shoji, Kazuo; Safwat, Abdel Azeim; Marechal, Jean Didier; Perahia, David; Suzuki, Hisanori; Romeo, Sergio

    2013-01-01

    Our previous studies showed that (-)-epigallocatechin-3-gallate (EGCG) inhibits signal transducer activator of transcription 1 (STAT1) activation. Since EGCG may be a promising lead compound for new anti-STAT1 drug design, 15 synthetic catechins

  17. Study of lead phytoavailability for atmospheric industrial micronic and sub-micronic particles in relation with lead speciation

    Energy Technology Data Exchange (ETDEWEB)

    Uzu, G. [EcoLab UMR 5245 CNRS-INPT-UPS, ENSAT BP 32607 Auzeville Tolosane, 31326 Castanet Tolosan (France)], E-mail: gaelle.uzu@ensat.fr; Sobanska, S. [LASIR UMR 8516, Universite des Sciences et Technologies de Lille, Batiment C5, 59655 Villeneuve d' Ascq Cedex (France)], E-mail: Sophie.Sobanska@univ-lille1.fr; Aliouane, Y. [EcoLab UMR 5245 CNRS-INPT-UPS, ENSAT BP 32607 Auzeville Tolosane, 31326 Castanet Tolosan (France); Pradere, P. [Chemical Metal Treatment Company, STCM, 30-32 chemin de Fondeyre, 31200 Toulouse (France)], E-mail: p.pradere@stc-metaux.com; Dumat, C. [EcoLab UMR 5245 CNRS-INPT-UPS, ENSAT BP 32607 Auzeville Tolosane, 31326 Castanet Tolosan (France)], E-mail: camille.dumat@ensat.fr

    2009-04-15

    Particles from channelled emissions of a battery recycling facility were size-segregated and investigated to correlate their speciation and morphology with their transfer towards lettuce. Microculture experiments carried out with various calcareous soils spiked with micronic and sub-micronic particles (1650 {+-} 20 mg Pb kg{sup -1}) highlighted a greater transfer in soils mixed with the finest particles. According to XRD and Raman spectroscopy results, the two fractions presented differences in the amount of minor lead compounds like carbonates, but their speciation was quite similar, in decreasing order of abundance: PbS, PbSO{sub 4}, PbSO{sub 4}.PbO, {alpha}-PbO and Pb{sup 0}. Morphology investigations revealed that PM{sub 2.5} (i.e. Particulate Matter 2.5 composed of particles suspended in air with aerodynamic diameters of 2.5 {mu}m or less) contained many Pb nanoballs and nanocrystals which could influence lead availability. The soil-plant transfer of lead was mainly influenced by size and was very well estimated by 0.01 M CaCl{sub 2} extraction. - The soil-lettuce lead transfer from atmospheric industrial sub-micronic and micronic particles depends on particle size.

  18. Study of lead phytoavailability for atmospheric industrial micronic and sub-micronic particles in relation with lead speciation

    International Nuclear Information System (INIS)

    Uzu, G.; Sobanska, S.; Aliouane, Y.; Pradere, P.; Dumat, C.

    2009-01-01

    Particles from channelled emissions of a battery recycling facility were size-segregated and investigated to correlate their speciation and morphology with their transfer towards lettuce. Microculture experiments carried out with various calcareous soils spiked with micronic and sub-micronic particles (1650 ± 20 mg Pb kg -1 ) highlighted a greater transfer in soils mixed with the finest particles. According to XRD and Raman spectroscopy results, the two fractions presented differences in the amount of minor lead compounds like carbonates, but their speciation was quite similar, in decreasing order of abundance: PbS, PbSO 4 , PbSO 4 .PbO, α-PbO and Pb 0 . Morphology investigations revealed that PM 2.5 (i.e. Particulate Matter 2.5 composed of particles suspended in air with aerodynamic diameters of 2.5 μm or less) contained many Pb nanoballs and nanocrystals which could influence lead availability. The soil-plant transfer of lead was mainly influenced by size and was very well estimated by 0.01 M CaCl 2 extraction. - The soil-lettuce lead transfer from atmospheric industrial sub-micronic and micronic particles depends on particle size

  19. Porosity study of synthetic sandstones by non-destructive nuclear techniques

    International Nuclear Information System (INIS)

    Marques, Leonardo Carmezini

    2008-01-01

    In this paper, nuclear techniques have been used to describe structural characteristics of ceramic samples. These samples were produced to serve as simulates of sandstones and their mainly component was silica (SiO 2 ). Three sets of these samples with different characteristics were analyzed with the gamma ray transmission and the X-ray microtomography. They had the function to describe parameters as porosity point to point and total average porosity, for the transmission case, and 2D sections average porosity, total average porosity and size porous distribution for microtomography, as well as to investigate possible irregularities in bulk sample. The experimental set up for the Gamma Ray Transmission technique consisted of: a 2'' x 2'' crystal NaI(Tl) detector, an 241 Am radioactive source (59.54 keV, 100 mCi), an automatic micrometric table for the sample XZ movement and standard gamma spectrometry electronics. Lead collimators with 2 mm diameter were placed on the source way out and on the detector entrance. The microtomographic measurements were done with a Skyscan system, model 1172, with a X -ray tube with 20 - 100 kV of voltage range and a CCD camera. Employing gamma ray transmission method was possible to obtain overall porosity values from 25.8 to 34.0 % and from 24.8 to 29.2 % for samples with parallelepiped and cylinder shape, respectively, for ceramic I set; from 58.5 to 61.0 % and from 57.1 to 61.7 % for the same geometric shape of ceramic II set. The samples analyzed by the microtomography achieved resolutions of 1.73 μm, 0.64 μm and 1.28 μm for samples of ceramic set I, II and III, respectively. This methodology provided average total porosity values from 26.6 to 29.4 %, from 48.4 to 51.0 % and from 28.2 to 30.6 % to I, II and III ceramic sets, respectively. The porous size profiles of each ceramic sample were also measured. (author)

  20. Study of the porosity of synthetic sandstones by nondestructive nuclear techniques

    International Nuclear Information System (INIS)

    Marques, Leonardo Carmezini

    2008-01-01

    In this paper, nuclear techniques have been used to describe structural characteristics of ceramic samples. These samples were produced to serve as simulates of sandstones and their mainly component was silica (SiO 2 ). Three sets of these samples with different characteristics were analyzed with the gamma ray transmission and the X-ray microtomography. They had the function to describe parameters as porosity point to point and total average porosity, for the transmission case, and 2D sections average porosity, total average porosity and size porous distribution for microtomography, as well as to investigate possible irregularities in bulk sample. The experimental set up for the gamma ray transmission technique consisted of: a 2 x 2 crystal NaI(Tl) detector, an 241 Am radioactive source (59.54 keV, 100 mCi), an automatic micrometric table for the sample XZ movement and standard gamma spectrometry electronics. Lead collimators with 2 mm diameter were placed on the source way out and on the detector entrance. The microtomographic measurements were done with a Skyscan system, model 1172, with a X-ray tube with 20-100 kV of voltage range and a CCD camera. Employing gamma ray transmission method was possible to obtain overall porosity values from 25.8 to 34.0 % and from 24.8 to 29.2 % for samples with parallelepiped and cylinder shape, respectively, for ceramic I set; from 58.5 to 61.0 % and from 57.1 to 61.7 % for the same geometric shape of ceramic II set. The samples analyzed by the microtomography achieved resolutions of 1.73 μm, 0.64 μm and 1.28 μm for samples of ceramic set I, II and III, respectively. This methodology provided average total porosity values from 26.6 to 29.4 %, from 48.4 to 51.0 % and from 28.2 to 30.6 % to I, II and III ceramic sets, respectively. The porous size profiles of each ceramic sample were also measured. (author)

  1. Reporting on the case study of synthetic meat:summary of findings and policy considerations

    OpenAIRE

    Gunnarsdottir, Kristrun; Strand, Roger; Stephens, Neil; O'Riordan, Kate; Fotopoulou, Aristea; Giampietro, Mario; Kovacic, Zora; Lemkow Zetterling, Louis; Di Masso Tarditti, Marina

    2015-01-01

    The in-vitro meat (IVM) research field remains small with perhaps 50 or so scientists active globally. These scientists are in the Netherlands, the US, the UK, Sweden, Israel and Norway, with some interest expressed in Denmark and by a group of bioreactor engineers in Portugal.The aim of the Epinet case study was to explore and interact with these epistemic communities / networks that have been developing, implementing, supporting and promoting IVM technologies. The study team consisted of ex...

  2. In vivo evaluation of biofunctionalized implant surfaces with a synthetic peptide (P-15) and its impact on osseointegration. A preclinical animal study.

    Science.gov (United States)

    Schmitt, Christian M; Koepple, Markus; Moest, Tobias; Neumann, Konrad; Weisel, Tamara; Schlegel, Karl Andreas

    2016-11-01

    The overall aim of the study was to investigate a biofunctionalized implant surface with electrochemically deposition of hydroxyapatite and the synthetic peptide (P-15) and its effect on osseointegration. Three modified implant types of ANKYLOS ® C/X implants were used; (1) machined implants used as negative control (M, n = 20), (2) implants with the FRIADENT ® plus surface (grit blasted and acid-etched) used as positive control (P, n = 20), and (3) implants with a biomimetic surface consisting of hydroxyapatite and the synthetic 15 aminoacids containing peptide P-15 (BP, n = 40). The implants were randomly inserted in the mandibles of 10 beagle dogs following 4 months after tooth extraction (P1-P4). Three animals were sacrificed 2 and 7 days after implant insertion, respectively, and four animals were sacrificed 6 months post implant insertion. Bone-to-implant contacts (BICs) were analyzed via histomorphometrical analyses at five different region of interests (ROIs); two at the middle part on either side of the implant (ROI 1/4), two at the apical part of the implant at each side (ROI 2/3), and one at the tip of the implant (ROI 5). All implant surfaces showed a high level of osseointegration and osteoconductivity. The cumulative implant survival rate (CSR) was 93.8%, 100% in the M, 85% in the P, and 95% in the BP group. No statistical difference in BICs at ROI 1/4, 2/3, and 5 could be shown between implant types following 2 and 7 days of healing. BIC values increased in all groups over time. After 6 months of healing the BP group showed superiority in BIC in ROI 2/3 (73.2 ± 15.6%) compared to the P (48.3 ± 10.6%) and M group (66.3 ± 30.2%) with a significant difference between BP and P (P = 0.002). It is hypothesized, that the surface biofunctionalization improves peri-implant bone formation and remodeling, leading to an increased bone-to implant contact. However, within the limitations of the study set-up no benefit in the early phase of

  3. Synthetic prions and other human neurodegenerative proteinopathies.

    Science.gov (United States)

    Le, Nhat Tran Thanh; Narkiewicz, Joanna; Aulić, Suzana; Salzano, Giulia; Tran, Hoa Thanh; Scaini, Denis; Moda, Fabio; Giachin, Gabriele; Legname, Giuseppe

    2015-09-02

    Transmissible spongiform encephalopathies (TSE) are a heterogeneous group of neurodegenerative disorders. The common feature of these diseases is the pathological conversion of the normal cellular prion protein (PrP(C)) into a β-structure-rich conformer-termed PrP(Sc). The latter can induce a self-perpetuating process leading to amplification and spreading of pathological protein assemblies. Much evidence suggests that PrP(Sc) itself is able to recruit and misfold PrP(C) into the pathological conformation. Recent data have shown that recombinant PrP(C) can be misfolded in vitro and the resulting synthetic conformers are able to induce the conversion of PrP(C) into PrP(Sc)in vivo. In this review we describe the state-of-the-art of the body of literature in this field. In addition, we describe a cell-based assay to test synthetic prions in cells, providing further evidence that synthetic amyloids are able to template conversion of PrP into prion inclusions. Studying prions might help to understand the pathological mechanisms governing other neurodegenerative diseases. Aggregation and deposition of misfolded proteins is a common feature of several neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and other disorders. Although the proteins implicated in each of these diseases differ, they share a common prion mechanism. Recombinant proteins are able to aggregate in vitro into β-rich amyloid fibrils, sharing some features of the aggregates found in the brain. Several studies have reported that intracerebral inoculation of synthetic aggregates lead to unique pathology, which spread progressively to distal brain regions and reduced survival time in animals. Here, we review the prion-like features of different proteins involved in neurodegenerative disorders, such as α-synuclein, superoxide dismutase-1, amyloid-β and tau. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Case Studies of Leading Edge Small Urban High Schools. Relevance Strategic Designs: 4. Boston Arts Academy

    Science.gov (United States)

    Shields, Regis Anne; Ireland, Nicole; City, Elizabeth; Derderian, Julie; Miles, Karen Hawley

    2008-01-01

    This report is one of nine detailed case studies of small urban high schools that served as the foundation for the Education Resource Strategies (ERS) report "Strategic Designs: Lessons from Leading Edge Small Urban High Schools." These nine schools were dubbed "Leading Edge Schools" because they stand apart from other high…

  5. Case Studies of Leading Edge Small Urban High Schools. Relevance Strategic Designs: 6. Perspectives Charter School

    Science.gov (United States)

    Shields, Regis Anne; Ireland, Nicole; City, Elizabeth; Derderian, Julie; Miles, Karen Hawley

    2008-01-01

    This report is one of nine detailed case studies of small urban high schools that served as the foundation for the Education Resource Strategies (ERS) report "Strategic Designs: Lessons from Leading Edge Small Urban High Schools." These nine schools were dubbed "Leading Edge Schools" because they stand apart from other high…

  6. The kinetics of ulvoespinel reduction - Synthetic study and applications to lunar rocks.

    Science.gov (United States)

    Mccallister, R. H.; Taylor, L. A.

    1973-01-01

    The kinetics of Fe2TiO4 reduction to FeTiO3 + Fe were studied using CO-CO2 gas mixtures with fO2 measured by a solid ceramic (calcia-zirconia) oxygen electrolyte cell. Isothermal rate studies at 900 C suggest that the mechanism of Fe2TiO4 reduction is one of nucleation and growth, where the growth stage may be controlled by the diffusion of the reactant through the product layer or volume diffusion. The activation energy for the growth stage of the process was determined to be 46 plus or minus 4 kcal/mole.

  7. Comparative study between bioapatite and synthetic hydroxyapatite obtained by chemical precipitation and mechanochemical synthesis

    International Nuclear Information System (INIS)

    Quispe M, J.; Moreno, M.; Montano, J.; Pillaca, M.; Guzman, A.; Cavero, A.; Arce, M.

    2009-01-01

    A comparative study between the inorganic component of a human bone tissue with respect of apatite synthesized by chemical precipitation, mechanochemical synthesis and a sample of commercial hidroxyapatite are shown. The samples were studied by X-ray diffraction, atomic absorption spectroscopy and Fourier transform infrared spectroscopy. The results show similar structural characteristics among all samples identifying that sample prepared by mechanochemical synthesis is a kind of hydroxyapatite which has substitutions of carbonate in its crystalline structure, similar to the inorganic component of bone tissue. (author).

  8. STUDIES ON NATURAL AND SYNTHETIC POLYMERS FOR CONTROLLED RELEASE MATRIX TABLET OF ACECLOFENAC

    OpenAIRE

    Abhishek S. Joshi *, Deepak A. Joshi , Avinash V. Dhobale , Sandhya S. Bundel , Vijay R. Chakote, Gunesh N. Dhembre

    2018-01-01

    The present study was aimed to design new oral controlled release matrix tablets of new NSAID Aceclofenac for once a day by using 10, 15, 20 and 25% of GG:HPMC and XG:HPMC mixture in the ratio 1:1 by wet granulation method. The prepared tablets subjected to in vitro drug release studies in pH 7.4 buffer solution. All the formulation meets the pre-compression and compression characteristics. All the tablets prepared with 10, 15, 20 and 25% of HPMC: XG mixture in the ratio 1:1 fails to meet the...

  9. A synthetic medical and sociological study on twins exposed by atomic bomb, 8

    International Nuclear Information System (INIS)

    Satow, Yukio; Watanabe, Shoji; Kyo, Taiichi

    1984-01-01

    The relationship between immunoglobulin (IgG, IgA, IgM) levels and the exposure status was examined in 13 enzygotic twin pairs who had been exposed to atomic bomb under the same or different conditions and who had no disease showing changes in immunoglobulin levels. The difference in immunoglobulin levels tended to be smaller between the twins exposed under the same conditions and to be larger between the twins exposed under the different conditions. This should be further studied because there were some exceptions in this study. (Namekawa, K.)

  10. Monopolar Stimulation of the Implanted Cochlea: A Synthetic Population-Based Study

    DEFF Research Database (Denmark)

    Mangado Lopez, Nerea; Ceresa, Mario; Dejea Velardo, Hector

    2016-01-01

    Cochlear implantation is carried out to recover the sense of hearing. However, its functional outcome varies highly between patients. In the current work, we present a study to assess the functional outcomes of cochlear implants considering the inter-variability found among a population of patien...

  11. The study of synthetic food dyes by positron annihilation lifetime spectroscopy

    International Nuclear Information System (INIS)

    Pivtsaev, A A; Razov, V I

    2015-01-01

    By method of positron annihilation lifetime spectroscopy (PALS), substances are food dyes were studied: E-102 (Tartrazine), E-124 (Ponso 4R), E 132 (Indigo carmine), E-133 (Brilliant Blue), E-151 (Black Shiny). They are examined for the presence of carcinogenic properties. The difference between dyes having explicit carcinogenic properties and mutagenic properties (non-explicit carcinogens) is established. (paper)

  12. The study of synthetic food dyes by positron annihilation lifetime spectroscopy.

    Science.gov (United States)

    Pivtsaev, A. A.; Razov, V. I.

    2015-06-01

    By method of positron annihilation lifetime spectroscopy (PALS), substances are food dyes were studied: E-102 (Tartrazine), E-124 (Ponso 4R), E 132 (Indigo carmine), E-133 (Brilliant Blue), E-151 (Black Shiny). They are examined for the presence of carcinogenic properties. The difference between dyes having explicit carcinogenic properties and mutagenic properties (non-explicit carcinogens) is established.

  13. Distribution of take-home opioid antagonist kits during a synthetic opioid epidemic in British Columbia, Canada: a modelling study

    Directory of Open Access Journals (Sweden)

    Michael A Irvine, PhD

    2018-05-01

    Full Text Available Summary: Background: Illicit use of high-potency synthetic opioids has become a global issue over the past decade. This misuse is particularly pronounced in British Columbia, Canada, where a rapid increase in availability of fentanyl and other synthetic opioids in the local illicit drug supply during 2016 led to a substantial increase in overdoses and deaths. In response, distribution of take-home naloxone (THN overdose prevention kits was scaled up (6·4-fold increase throughout the province. The aim of this study was to estimate the impact of the THN programme in terms of the number of deaths averted over the study period. Methods: We estimated the impact of THN kits on the ongoing epidemic among people who use illicit opioids in British Columbia and explored counterfactual scenarios for the provincial response. A Markov chain model was constructed explicitly including opioid-related deaths, fentanyl-related deaths, ambulance-attended overdoses, and uses of THN kits. The model was calibrated in a Bayesian framework incorporating population data between Jan 1, 2012, and Oct 31, 2016. Findings: 22 499 ambulance-attended overdoses and 2121 illicit drug-related deaths (677 [32%] deaths related to fentanyl were recorded in the study period, mostly since January, 2016. In the same period, 19 074 THN kits were distributed. We estimate that 298 deaths (95% credible interval [CrI] 91–474 were averted by the THN programme. Of these deaths, 226 (95% CrI 125–340 were averted in 2016, following a rapid scale-up in distribution of kits. We infer a rapid increase in fentanyl adulterant at the beginning of 2016, with an estimated 2·3 times (95% CrI 2·0–2·9 increase from 2015 to 2016. Counterfactual modelling indicated that an earlier scale-up of the programme would have averted an additional 118 deaths (95% CrI 64–207. Our model also indicated that the increase in deaths could parsimoniously be explained through a change in the fentanyl

  14. H2O removal from diesel and JP8 fuels: A comparison study between synthetic and natural dehydration agents

    Directory of Open Access Journals (Sweden)

    E. P. Favvas

    2014-08-01

    Full Text Available The comparison between Thermal Polyaspartate Anion, TPA, and natural resin in their effect on the improvement of the physicochemical properties of both conventional diesel and JP8 fuels is the main scope of this work. Specifically, both studied materials were used dehydration agents in order to increase the physicochemical properties of both treated fuels. The higher amount of the removed water was obtained when used the natural resin as adsorbent material. In this case the water concentration decreased into diesel up to 68.66 % and more than 30 % in the case of jet fuel (JP8. This water removal improves the studied physicochemical properties of both studied fuels, diesel and JP8, for example up to 633 J/g (using natural resin as dehydration agent (removable additive and 1040 J/g (using TPA as dehydration agent for the heat of combustion. Overall, the proposed method can be used in a simple fuel cleaning process using a metal mesh vessel of synthetic TPA polymer or natural resin. The higher water/humidity removal amount in conjunction with the very low price of the natural resin makes this material more promising for the up scaling of the proposed technique in the near future.

  15. Study of Baryon and Antibaryon Spectra in Lead Lead Interactions at 160 GeV/c per Nucleon

    CERN Multimedia

    2002-01-01

    % WA97 \\\\ \\\\ Hyperons are expected to be a useful probe for the dynamics of hadronic matter under extreme conditions. In particular the onset of a Quark-Gluon Plasma phase in a heavy ion collision is expected to enhance the hyperon yield with respect to normal hadronic interactions. \\\\ \\\\WA97 aims to measure the spectra of strange particles and in particular of hyperons and antihyperons produced in ultrarelativistic lead-lead interactions and to compare them with those from proton initiated reactions. The experiment covers central rapidity down to transverse momenta of a few hundred MeV/c. The experimental setup consists of: an array of multiplicity counters, a silicon based decay detector made of pixels, located in the CERN-OMEGA Spectrometer, an array of pad cathode MWPCs used as lever arm detectors and a zero degree hadron calorimeter. \\\\ \\\\

  16. Analysis of economic convergence through synthetic development indicators: the chilean case study

    Directory of Open Access Journals (Sweden)

    Víctor Fernando Figueroa Arcila

    2003-01-01

    Full Text Available This paper defends the use of convergence models to study the temporary evolution of the Chilean communes’ socioeconomic development. To do so, we will use an indicator made up of using multivariate analysis techniques. By means of regression models of transversal section and models of distributional dynamics we will outline, on the basis of the historic function of communal economies, the behaviour expected for those economies in future and, therefore, the tendencial evolution of Chilean territorial economic model.

  17. Defluoridation chemistry of synthetic hydroxyapatite at nano scale: Equilibrium and kinetic studies

    International Nuclear Information System (INIS)

    Sundaram, C. Sairam; Viswanathan, Natrayasamy; Meenakshi, S.

    2008-01-01

    This study describes the advantages of nano-hydroxyapatite (n-HAp), a cost effective sorbent for fluoride removal. n-HAp possesses a maximum defluoridation capacity [DC] of 1845 mg F - /kg which is comparable with that of activated alumina, a defluoridation agent commonly used in the indigenous defluoridation technology. A new mechanism of fluoride removal by n-HAp was proposed in which it is established that this material removes fluoride by both ion-exchange and adsorption process. The n-HAp and fluoride-sorbed n-HAp were characterized using XRD, FTIR and TEM studies. The fluoride sorption was reasonably explained with Langmuir, Freundlich and Redlich-Peterson isotherms. Thermodynamic parameters such as ΔG o , ΔH o , ΔS o and E a were calculated in order to understand the nature of sorption process. The sorption process was found to be controlled by pseudo-second-order and pore diffusion models. Field studies were carried out with the fluoride containing water sample collected from a nearby fluoride endemic area in order to test the suitability of n-HAp material as a defluoridating agent at field condition

  18. INVERSION OF FULL ACOUSTIC WAVEFIELD IN LOCAL HELIOSEISMOLOGY: A STUDY WITH SYNTHETIC DATA

    International Nuclear Information System (INIS)

    Cobden, L. J.; Warner, M. R.; Tong, C. H.

    2011-01-01

    We present the first results from the inversion of full acoustic wavefield in the helioseismic context. In contrast to time-distance helioseismology, which involves analyzing the travel times of seismic waves propagating into the solar interior, wavefield tomography models both the travel times and amplitude variations present in the entire seismic record. Unlike the use of ray-based, Fresnel-zone, Born, or Rytov approximations in previous time-distance studies, this method does not require any simplifications to be made to the sensitivity kernel in the inversion. In this study, the acoustic wavefield is simulated for all iterations in the inversion. The sensitivity kernel is therefore updated while lateral variations in sound-speed structure in the model emerge during the course of the inversion. Our results demonstrate that the amplitude-based inversion approach is capable of resolving sound-speed structures defined by relatively sharp vertical and horizontal boundaries. This study therefore provides the foundation for a new type of subsurface imaging in local helioseismology that is based on the inversion of the entire seismic wavefield.

  19. Study of the effects induced by lead on the emulsion films of the OPERA experiment

    CERN Document Server

    Anokhina, A.; Ariga, A.; Arrabito, L.; Autiero, D.; Badertscher, A.; Bay, F.; Bergnoli, A.; Bersani Greggio, F.; Besnier, M.; Bick, D.; Bozza, C.; Brugiere, T.; Brugnera, R.; Brunetti, G.; Buontempo, S.; Carrara, E.; Cazes, A.; Chaussard, L.; Chernyavsky, M.; Chiarella, V.; Chon-Sen, N.; Chukanov, A.; Consiglio, L.; Cozzi, M.; Dal Corso, F.; D'Amato, G.; D'Ambrosio, N.; De Lellis, G.; Declais, Y.; De Serio, M.; Di Capua, F.; Di Ferdinando, D.; Di Giovanni, A.; Di Marco, N.; Di Troia, C.; Dmitrievski, S.; Dominjon, A.; Dracos, M.; Duchesneau, D.; Dulach, B.; Dusini, S.; Ebert, J.; Egorov, O.; Enikeev, R.; Ereditato, A.; Esposito, L.S.; Favier, J.; Felici, G.; Ferber, T.; Fini, R.; Franceschi, A.; Fukuda, T.; Fukushima, C.; Galkin, V.I.; Galkin, V.A.; Garfagnini, A.; Giacomelli, G.; Giorgini, M.; Goellnitz, C.; Golubkov, D.; Gornoushkin, Y.; Grella, G.; Grianti, F.; Guler, M.; Gusev, G.; Gustavino, C.; Hagner, Caren; Hara, T.; Hierholzer, M.; Hiramatsu, S.; Hoshino, Kaoru; Ieva, M.; Jakovcic, K.; Janicsko Csathy, J.; Janutta, B.; Jollet, C.; Juget, F.; Kawai, T.; Kazuyama, M.; Kim, S.H.; Kimura, M.; Knuesel, J.; Kodama, K.; Komatsu, M.; Kose, U.; Kreslo, I.; Laktineh, I.; Lazzaro, C.; Lenkeit, J.; Ljubicic, A.; Longhin, Andrea; Lutter, G.; Manai, K.; Mandrioli, G.; Manzoor, S.; Marotta, A.; Marteau, J.; Matsuoka, H.; Mauri, N.; Meisel, F.; Meregaglia, A.; Messina, M.; Migliozzi, P.; Miyamoto, S.; Monacelli, P.; Morishima, K.; Moser, U.; Muciaccia, M.T.; Naganawa, N.; Naka, T.; Nakamura, M.; Nakamura, T.; Nakano, T.; Nikitina, V.; Niwa, K.; Nonoyama, Y.; Ogawa, S.; Osedlo, V.; Ossetski, D.; Paoloni, A.; Park, B.D.; Park, I.G.; Pastore, A.; Patrizii, L.; Pennacchio, E.; Pessard, H.; Pistillo, C.; Polukhina, N.; Pozzato, M.; Pretzl, K.; Publichenko, P.; Pupilli, F.; Roganova, T.; Rosa, G.; Rostovtseva, I.; Rubbia, A.; Russo, A.; Ryazhskaya, O.; Ryzhikov, D.; Sato, Y.; Sato, O.; Saveliev, V.; Sazhina, G.; Schembri, A.; Scotto Lavina, L.; Shibuya, H.; Simone, S.; Sioli, M.; Sirignano, C.; Sirri, G.; Song, J.S.; Spinetti, M.; Stanco, L.; Starkov, N.; Stipcevic, M.; Strauss, T.; Strolin, Paolo Emilio; Sugonyaev, V.; Taira, Y.; Takahashi, S.; Tenti, M.; Terranova, F.; Tioukov, V.; Togo, V.; Tolun, P.; Tsarev, V.; Tufanli, S.; Ushida, N.; Valieri, C.; Vilain, P.; Vladimirov, M.; Votano, L.; Vuilleumier, J.L.; Wilquet, G.; Wonsak, B.; Wurtz, J.; Yoon, C.S.; Yoshida, J.; Zaitsev, Y.; Zemskova, S.; Zghiche, A.; Zimmermann, R.

    2008-01-01

    The OPERA neutrino oscillation experiment is based on the use of the Emulsion Cloud Chamber (ECC). In the OPERA ECC, nuclear emulsion films acting as very high precision tracking detectors are interleaved with lead plates providing a massive target for neutrino interactions. We report on studies related to the effects occurring from the contact between emulsion and lead. A low radioactivity lead is required in order to minimize the number of background tracks in emulsions and to achieve the required performance in the reconstruction of neutrino events. It was observed that adding other chemical elements to the lead, in order to improve the mechanical properties, may significantly increase the level of radioactivity on the emulsions. A detailed study was made in order to choose a lead alloy with good mechanical properties and an appropriate packing technique so as to have a low enough effective radioactivity.

  20. Exploring the Binding of Barbital to a Synthetic Macrocyclic Receptor; a Charge Density Study

    DEFF Research Database (Denmark)

    Du, Jonathan J.; Hanrahan, Jane Rouse; Solomon, V. Raja

    2018-01-01

    Experimental charge density distribution studies, complemented by quantum mechanical theoretical calculations, of a host-guest system comprised of a macrocycle (1) and barbital (2) in a 1:1 ratio (3) have been carried out via high resolution single crystal X-ray diffraction. The data was modelled...... molecule. Visual comparison of the conformations of the macrocyclic ring shows the rotation by 180° of an amide bond attributed to competitive hydrogen bonding. It was found the intraannular and extraannular molecules inside were orientated to maximise the number of hydrogen bonds present...

  1. Blood lead levels in children with neurological disorders: a single centre preliminary study.

    Science.gov (United States)

    Mahmoudian, Touran; Modaresi, Mohamadreza; Zarei, Ali; Poursafa, Parinaz; Kelishadi, Roya

    2009-11-01

    Lead poisoning is a potentially devastating problem among young children. Chronic low level lead exposure can lead to learning disabilities and behavior changes such as colic, insomnia, hyperactivity, impaired growth, hearing loss and upper extremity weakness. The purpose of this cross sectional study was to determine the blood lead level in children with neurological disorders in comparison with healthy controls. Blood lead concentrations were measured by flame atomic absorption spectrometry in 100 children aged 1-10 years and suffering from various neurological disorders. One hundred age and sex-matched healthy children served as controls. The mean blood lead concentration was higher in children with neurological disorders than in controls (113.2 + or - 47.5 microg/L vs 84.7 + or - 38.0 microg/L; pchildren with neurological disorders and 19% of controls were found to have increased blood lead levels, i.e.>100 microg/L. An increase in blood lead level in children might be related to neurological disorders. The measurement of blood lead level might be included in diagnostic eveluation of children with neurological disorders.

  2. A study on the treatment of radioactive liquid wastes using synthetic by air intake system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, T. G.; Lee, Y. H.; An, S. J.; Son, J. S.; Hong, K. P. [KAERI, Taejon (Korea, Republic of)

    2003-07-01

    In this study based on the mass transfer theory, experiments for the evaporation rates depending on various conditions were carried out through the operation of the existing Natural Evaporation Facility in KAERI. Evaporation media were made of the cotton and polyester. Air circulation in the facility was forced by exhausting fans. The evaporation rate and the decontamination factor were calculated by the result of experiment. The evaporation rate increased as the flow rate of air supply, the feed rate of liquid waste, and the temperature of supplied air increased. As for the humility of supplied air, the evaporation rate was getting higher as the humidity was getting lower. As the result of this study, operation conditions of the Natural Evaporation Facility are optimized as follows; The air temperature above 8C .deg., the air humidity below 70%, the air flow rate 1.14-1.47 m/sec, and the liquid waste feed rate 4.6l/hr.m{sup 2}. The decontamination factor and the radioactivity are 5.1x10{sup 3} and 4.7x10{sup -13}{mu}Ci/ml respectively, at the above mentioned optimum operation conditions. The air factor in the Dalton's equation for evaporation was determined from results of experiment on the temperature, the humidity, and the flow rate of supplied air as following; Eh=(0.0168+0.0141V){delta}H.

  3. A study on the treatment of radioactive liquid wastes using synthetic by air intake system

    International Nuclear Information System (INIS)

    Kim, T. G.; Lee, Y. H.; An, S. J.; Son, J. S.; Hong, K. P.

    2003-01-01

    In this study based on the mass transfer theory, experiments for the evaporation rates depending on various conditions were carried out through the operation of the existing Natural Evaporation Facility in KAERI. Evaporation media were made of the cotton and polyester. Air circulation in the facility was forced by exhausting fans. The evaporation rate and the decontamination factor were calculated by the result of experiment. The evaporation rate increased as the flow rate of air supply, the feed rate of liquid waste, and the temperature of supplied air increased. As for the humility of supplied air, the evaporation rate was getting higher as the humidity was getting lower. As the result of this study, operation conditions of the Natural Evaporation Facility are optimized as follows; The air temperature above 8C .deg., the air humidity below 70%, the air flow rate 1.14-1.47 m/sec, and the liquid waste feed rate 4.6l/hr.m 2 . The decontamination factor and the radioactivity are 5.1x10 3 and 4.7x10 -13 μCi/ml respectively, at the above mentioned optimum operation conditions. The air factor in the Dalton's equation for evaporation was determined from results of experiment on the temperature, the humidity, and the flow rate of supplied air as following; Eh=(0.0168+0.0141V)ΔH

  4. Study on manufacturing technique of synthetic shock-absorbers for underground disposal of high-level radioactive wastes

    International Nuclear Information System (INIS)

    Iwasaki, Takashi; Onodera, Yoshio; Hayashi, Hiromichi; Ebina, Takeo; Nagase, Takako; Torii, Kazuo

    1997-01-01

    On the cse of underground disposal of high level radioactive wastes, natural bentonite is planned to be used for artificial barrier shock-absorber. This is due to expectation of sealing water or adsorbing nuclear materials using swelling and ion-exchanging capacities of smectite, which is a main component of bentonite. In this study, some swelling laminar compounds with various compositions and structures are synthesized to investigate their water sealing and nuclear adsorbing properties. And, according to their results, an optimum material is selected to develop its economic manufacturing method and investigate its alternative possibility for natural bentonite. From such reason, following two titled studies have been executed; 1) Synthesis of the swelling laminar compounds, and 2) Development of manufacturing technique of artificial shock-absorber. In 1995 FY, 1) Detail investigation on synthetic condition of double octahedral type smectite and 2) modeling of the smectite and stability of same type displacement for base of inducing the computer simulation for estimating creation process of optimum materials, were conducted. (G.K.)

  5. Analysis of ERS 1 synthetic aperture radar data of frozen lakes in northern Montana and implications for climate studies

    Science.gov (United States)

    Hall, Dorothy K.; Fagre, Daniel B.; Klasner, Fritz; Linebaugh, Gregg; Liston, Glen E.

    1994-01-01

    Lakes that freeze each winter are good indicators of regional climate change if key parameters, such as freeze-up and breakup date and maximum ice thickness, are measured over a decade-scale time frame. Synthetic aperture radar (SAR) satellite data have proven to be especially useful for measurement of climatologically significant parameters characteristic of frozen lakes. In this paper, five lakes in Glacier National Park, Montana, have been studied both in the field and using Earth Remote-Sensing Satellite (ERS) 1 SAR data during the 1992-1993 winter. The lakes are characterized by clear ice, sometimes with tubular or rounded bubbles, and often with a layer of snow ice on top of the clear ice. They are also often snow covered. Freeze-up is detected quite easily using ERS 1 SAR data as soon as a thin layer of ice forms. The effect of snow ice on the backscatter is thought to be significant but is, as yet, undetermined. On the five lakes studied, relative backscatter was found to increase with ice thickness until a maximum was reached in February. Breakup, an often ill-defined occurrence, is difficult to detect because surface water causes the SAR signal to be absorbed, thus masking the ice below. Comparison of the bubble structure of thaw lakes in northern Alaska with lakes in northern Montana has shown that the ice structure is quite different, and this difference may contribute to differential SAR signature evolution in the lakes of the two areas.

  6. Adsorption studies on fruits of Gular (Ficus glomerata): Removal of Cr(VI) from synthetic wastewater

    International Nuclear Information System (INIS)

    Rao, Rifaqat A.K.; Rehman, Fouzia

    2010-01-01

    The adsorption of Cr(VI) was studied in batch system using fruits of Ficus glomerata as adsorbent. The effect of temperature, pH, initial Cr(VI) concentration and time was investigated. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) was used to investigate surface morphology and active functional groups present on the adsorbent surface. Thermodynamic parameters like free energy change (ΔG 0 ), enthalpy (ΔH 0 ) and entropy (ΔS 0 ) indicate the spontaneous, endothermic and increased randomness nature of Cr(VI) adsorption. Equilibrium data were fitted well with Langmuir isotherm at 50 deg. C. The magnitude of mean free energy indicates chemical nature of adsorption. The breakthrough and exhaustive capacities were found to be 5 and 23.1 mg g -1 respectively. The applicability of the adsorbent has been demonstrated by removing Cr(VI) from electroplating wastewater.

  7. Quantitative structure-toxicity relationship study of some natural and synthetic coumarins using retention parameters

    Directory of Open Access Journals (Sweden)

    Rabtti El Hadi M.A.

    2012-01-01

    Full Text Available Four lipophilicity descriptors (RM0, b, C0, PC1 for twelve coumarine derivatives were determined by reversed-phase thin-layer chromatography in order to analyze which descriptor best describes the lipophilicity of coumarines investigated. Moreover, possible chemical toxicity of coumarins, expressed as the probability of a compound to cause organ-specific health effects, was calculated using ACD/Tox Suite program. The quantitative relationships between toxicity and molecular descriptors, including experimentally determined lipophilicity descriptors obtained in current study, were investigated using partial least square regression. The best models were obtained for kidney and liver health effects. Quantitative structure-toxicity relationship models revealed the importance of electric polarization descriptors, size descriptors and lipophilicity descriptors. Obtained models were used for the selection of the structural features of the compounds that are significantly affecting their absorption, distribution, metabolism, excretion, and toxicity. [Acknowledgements. This work has been supported by the Ministry of Education and Science of Serbia, Grant 172017.

  8. Synthesis, characterization and computational study of the newly synthetized sulfonamide molecule

    Science.gov (United States)

    Murthy, P. Krishna; Suneetha, V.; Armaković, Stevan; Armaković, Sanja J.; Suchetan, P. A.; Giri, L.; Rao, R. Sreenivasa

    2018-02-01

    A new compound N-(2,5-dimethyl-4-nitrophenyl)-4-methylbenzenesulfonamide (NDMPMBS) has been derived from 2,5-dimethyl-4-nitroaniline and 4-methylbenzene-1-sulfonyl chloride. Structure was characterized by SCXRD studies and spectroscopic tools. Compound crystallized in the monoclinic crystal system with P21/c space group a = 10.0549, b = 18.967, c = 8.3087, β = 103.18 and Z = 4. Type and nature of intermolecular interaction in crystal state investigated by 3D-Hirshfeld surface and 2D-finger print plots revealed that title compound stabilized by several interactions. The structural and electronic properties of title compound have been calculated at DFT/B3LYP/6-311G++(d,p) level of theory. Computationally obtained spectral data was compared with experimental results, showing excellent mutual agreement. Assignment of each vibrational wave number was done on the basis of potential energy distribution (PED). Investigation of local reactivity descriptors encompassed visualization of molecular electrostatic potential (MEP) and average local ionization energy (ALIE) surfaces, visualization of Fukui functions, natural bond order (NBO) analysis, bond dissociation energies for hydrogen abstraction (H-BDE) and radial distribution functions (RDF) after molecular dynamics (MD) simulations. MD simulations were also used in order to investigate interaction of NDMPMBS molecule with 1WKR and 3ETT proteins protein.

  9. An Insight into the Pharmacophores of Phosphodiesterase-5 Inhibitors from Synthetic and Crystal Structural Studies

    Energy Technology Data Exchange (ETDEWEB)

    Chen,G.; Wang, H.; Robinson, H.; Cai, J.; Wan, Y.; Ke, H.

    2008-01-01

    Selective inhibitors of cyclic nucleotide phosphodiesterase-5 (PDE5) have been used as drugs for treatment of male erectile dysfunction and pulmonary hypertension. An insight into the pharmacophores of PDE5 inhibitors is essential for development of second generation of PDE5 inhibitors, but has not been completely illustrated. Here we report the synthesis of a new class of the sildenafil derivatives and a crystal structure of the PDE5 catalytic domain in complex with 5-(2-ethoxy-5-(sulfamoyl)-3-thienyl)-1-methyl-3-propyl-1, 6-dihydro-7H-pyrazolo[4, 3-d]pyrimidin-7-one (12). Inhibitor 12 induces conformational change of the H-loop (residues 660-683), which is different from any of the known PDE5 structures. The pyrazolopyrimidinone groups of 12 and sildenafil are well superimposed, but their sulfonamide groups show a positional difference of as much as 1.5 Angstroms . The structure-activity analysis suggests that a small hydrophobic pocket and the H-loop of PDE5 are important for the inhibitor affinity, in addition to two common elements for binding of almost all the PDE inhibitors: the stack against the phenylalanine and the hydrogen bond with the invariant glutamine. However, the PDE5-12 structure does not provide a full explanation to affinity changes of the inhibitors. Thus alternatives such as conformational change of the M-loop are open and further structural study is required.

  10. Acid production potentials of massive sulfide minerals and lead-zinc mine tailings: a medium-term study.

    Science.gov (United States)

    Çelebi, Emin Ender; Öncel, Mehmet Salim; Kobya, Mehmet

    2018-01-01

    Weathering of sulfide minerals is a principal source of acid generation. To determine acid-forming potentials of sulfide-bearing materials, two basic approaches named static and kinetic tests are available. Static tests are short-term, and easily undertaken within a few days and in a laboratory. In contrast, kinetic tests are long-term procedures and mostly carried out on site. In this study, experiments were conducted over a medium-term period of 2 months, not as short as static tests and also not as long as kinetic tests. As a result, pH and electrical conductivity oscillations as a function of time, acid-forming potentials and elemental contents of synthetically prepared rainwater leachates of massive sulfides and sulfide-bearing lead-zinc tailings from abandoned and currently used deposition areas have been determined. Although the lowest final pH of 2.70 was obtained in massive pyrite leachate, massive chalcopyrite leachate showed the highest titrable acidity of 1.764 g H 2 SO 4 /L. On the other hand, a composite of currently deposited mine tailings showed no acidic characteristic with a final pH of 7.77. The composite abandoned mine tailing leachate had a final pH of 6.70, close to the final pH of massive galena and sphalerite leachates, and produced a slight titrable acidity of 0.130 g H 2 SO 4 /L.

  11. Comparative study of lead borate and bismuth lead borate glass systems as gamma-radiation shielding materials

    International Nuclear Information System (INIS)

    Singh, Narveer; Singh, Kanwar Jit; Singh, Kulwant; Singh, Harvinder

    2004-01-01

    Gamma-ray mass attenuation coefficients have been measured experimentally and calculated theoretically for PbO-B 2 O 3 and Bi 2 O 3 -PbO-B 2 O 3 glass systems using narrow beam transmission method. These values have been used to calculate half value layer (HVL) parameter. These parameters have also been calculated theoretically for some standard radiation shielding concretes at same energies. Effect of replacing lead by bismuth has been analyzed in terms of density, molar volume and mass attenuation coefficient

  12. On the study of wavy leading-edge vanes to achieve low fan interaction noise

    Science.gov (United States)

    Tong, Fan; Qiao, Weiyang; Xu, Kunbo; Wang, Liangfeng; Chen, Weijie; Wang, Xunnian

    2018-04-01

    The application of wavy leading-edge vanes to reduce a single-stage axial fan noise is numerically studied. The aerodynamic and acoustic performance of the fan is numerically investigated using a hybrid unsteady Reynolds averaged Navier-Stokes (URANS)/acoustic analogy method (Goldstein equations). First, the hybrid URANS/Goldstein method is developed and successfully validated against experiment results. Next, numerical simulations are performed to investigate the noise reduction effects of the wavy leading-edge vanes. The aerodynamic and acoustic performance is assessed for a fan with vanes equipped with two different wavy leading-edge profiles and compared with the performance of conventional straight leading-edge vanes. Results indicate that a fan with wavy leading-edge vanes produces lower interaction noise than the baseline fan without a significant loss in aerodynamic performance. In fact, it is demonstrated that wavy leading-edge vanes have the potential to lead to both aerodynamic and acoustic improvements. The two different wavy leading-edge profiles are shown to successfully reduce the fan tone sound power level by 1.2 dB and 4.3 dB, respectively. Fan efficiency is also improved by about 1% with one of the tested wavy leading-edge profiles. Large eddy simulation (LES) is also performed for a simplified fan stage model to assess the effects of wavy leading-edge vanes on the broadband fan noise. Results indicate that the overall sound power level of a fan can be reduced by about 4 dB with the larger wavy leading-edge profile. Finally, the noise reduction mechanisms are investigated and analysed. It is found that the wavy leading-edge profiles can induce significant streamwise vorticity around the leading-edge protuberances and reduce pressure fluctuations (especially at locations of wavy leading-edge hills) and unsteady forces on the stator vanes. The underlying mechanism of the reduced pressure fluctuations is also discussed by examining the magnitude

  13. Guided bone regeneration with a synthetic biodegradable membrane: a comparative study in dogs.

    Science.gov (United States)

    Jung, Ronald E; Kokovic, Vladimir; Jurisic, Milan; Yaman, Duygu; Subramani, Karthikeyan; Weber, Franz E

    2011-08-01

    The aim of the present study was to compare a newly developed biodegradable polylactide/polyglycolide/N-methyl-2-pyrrolidone (PLGA/NMP) membrane with a standard resorbable collagen membrane (RCM) in combination with and without the use of a bone substitute material (deproteinized bovine bone mineral [DBBM]) looking at the proposed tenting effect and bone regeneration. In five adult German sheepdogs, the mandibular premolars P2, P3, P4, and the molar M1 were bilaterally extracted creating two bony defects on each site. A total of 20 dental implants were inserted and allocated to four different treatment modalities within each dog: PLGA/NMP membrane only (Test 1), PLGA/NMP membrane with DBBM (Test 2), RCM only (negative control), and RCM with DBBM (positive control). A histomorphometric analysis was performed 12 weeks after implantation. For statistical analysis, a Friedman test and subsequently a Wilcoxon signed ranks test were applied. In four out of five PLGA/NMP membrane-treated defects, the membranes had broken into pieces without the support of DBBM. This led to a worse outcome than in the RCM group. In combination with DBBM, both membranes revealed similar amounts of area of bone regeneration and bone-to-implant contact without significant differences. On the level of the third implant thread, the PLGA/NMP membrane induced more horizontal bone formation beyond the graft than the RCM. The newly developed PLGA/NMP membrane performs equally well as the RCM when applied in combination with DBBM. Without bone substitute material, the PLGA/NMP membrane performed worse than the RCM in challenging defects, and therefore, a combination with a bone substitute material is recommended. © 2010 John Wiley & Sons A/S.

  14. Comparative study on in vitro biocompatibility of synthetic octacalcium phosphate and calcium phosphate ceramics used clinically.

    Science.gov (United States)

    Morimoto, Shinji; Anada, Takahisa; Honda, Yoshitomo; Suzuki, Osamu

    2012-08-01

    The present study was designed to investigate the extent to which calcium phosphate bone substitute materials, including osteoconductive octacalcium phosphate (OCP), display cytotoxic and inflammatory responses based on their dissolution in vitro. Hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) ceramics, which are clinically used, as well as dicalcium phosphate dihydrate (DCPD) and synthesized OCP were compared. The materials were well characterized by chemical analysis, x-ray diffraction and Fourier transform infrared spectroscopy. Calcium and phosphate ion concentrations and the pH of culture media after immersion of the materials were determined. The colony forming rate of Chinese hamster lung fibroblasts was estimated with extraction of the materials. Proliferation of bone marrow stromal ST-2 cells and inflammatory cytokine TNF-α production by THP-1 cells grown on the material-coated plates were examined. The materials had characteristics that corresponded to those reported. DCPD was shown to dissolve the most in the culture media, with a marked increase in phosphate ion concentration and a reduction in pH. ST-2 cells proliferated well on the materials, with the exception of DCPD, which markedly inhibited cellular growth. The colony forming capacity was the lowest on DCPD, while that of the other calcium phosphates was not altered. In contrast, TNF-α was not detected even in cells grown on DCPD, suggesting that calcium phosphate materials are essentially non-inflammatory, while the solubility of the materials can affect osteoblastic and fibroblastic cellular attachment. These results indicate that OCP is biocompatible, which is similar to the materials used clinically, such as HA. Therefore, OCP could be clinically used as a biocompatible bone substitute material.

  15. Treatability Study Report for In SITU Lead Immobilization Using Phosphate-Based Binders

    National Research Council Canada - National Science Library

    Bricka, R. M; Marwaha, Anirudha; Fabian, Gene L

    2008-01-01

    .... The treatability study described in this report was designed to develop the information necessary to support the immobilization of lead contaminants in soil by in situ treatment with phosphate-based binders...

  16. Blood Lead Concentrations in 1–3 Year Old Lebanese Children: A Cross-sectional study

    OpenAIRE

    Salem George; Mikati Mohamed; Kouzi Sarah; Muwakkit Samar; Nabulsi Mona; Nuwayhid Iman; Ariss Majd

    2003-01-01

    Abstract Background Childhood lead poisoning has not made the list of national public health priorities in Lebanon. This study aims at identifying the prevalence and risk factors for elevated blood lead concentrations (B-Pb ≥ 100 μg/L) among 1–3 year old children. It also examines the need for universal blood lead screening. Methods This is a cross-sectional study of 281 well children, presenting to the pediatric ambulatory services at the American University of Beirut Medical Center in 1997–...

  17. Comparative Study on Performance and Organic Fouling of ZrO2 Ceramic Membranes in Ultrafiltration of Synthetic Water and Wastewater Treatment Plant Effluent

    KAUST Repository

    Li, Cen

    2011-07-01

    Adsorption of organic matter on ceramic membrane can lead to hydraulic-irreversible fouling, which decreases the permeate flux and the cost-efficiency of membrane devices. In order to optimize the filtration process, detailed information is necessary about the organic fouling mechanisms on ceramic membranes. In this study, dead-end filtration experiments of both synthetic water and secondary effluent from a wastewater treatment plant (WWTP) were conducted on a ZrO2 ceramic membrane. The experiment results of synthetic water showed that humic acid (HA) was able to be adsorbed by the ZrO2 membrane and cause permeate flux decline; and that HA-tryptophan mixture, at the same DOC level, promoted the filtration flux decline; DOC removal in the case of HA-tryptophan was lower than that of HA alone. It seems that hydrophilic organic matter with low molecular weight have some specific contribution to the organic fouling of the ZrO2 membrane. The results also suggest that tryptophan molecules were preferentially adsorbed on the membrane at the beginning, exposing their hydrophobic sides which might further adsorb HA from the feed water. During the filtration of WWTP effluent, protein-like substances (mainly tryptophan-like) were also preferentially adsorbed on the membrane compared with humic-like ones in the initial few cycles of filtration. More humic-like substances were adsorbed in the following filtration cycles due to the increase of membrane hydrophobicity. A significant rise in hydraulic-irreversible flux decline was obtained by decreasing pH from near pHpzc to below pHpzc of the membrane. It suggests that a positively charged surface is preferred for HA adsorption. Ionic strength increase did not affect the filtration of HA, but it lessened the hydraulic-irreversible flux decline of HA-tryptophan filtration. The adsorption of HA-tryptophan can be attributed to outersphere interaction while HA adsorption is mainly caused by inner-sphere interaction. The results of

  18. Studies of lead pollution in the air of Shanghai by multiple techniques

    International Nuclear Information System (INIS)

    Tan, M.G.; Zhang, G.L.; Li, X.L.; Zhang, Y.X.; Yue, W.S.; Chen, J.M.; Wang, Y.S.; Li, A.G.; Li, Y.; Zhang, Y.M.; Shan, Z.C.

    2005-01-01

    Lead pollution in atmosphere has been one of the worrisome environmental problems since the tetraethyl lead was used as an antiknock agent in combustion engines. The presence of lead in urban air, even at low doses, may cause neurological impairments of fetuses and young children. Studies also show that lead may be a factor in high blood pressure and subsequent heart disease. Atmospheric lead has various origins, such as gasoline, industrial emissions and coal burning etc. The present work reports the lead levels in air particulate matter samples of PM 10 collected in recent years to evaluate the effect of the use of unleaded gasoline in Shanghai since 1997. The chemical species of lead in PM 10 and their origins were also studied. To our knowledge it is a first time to give an estimation of lead contribution to air in a city from different emission sources quantitatively. Proton-induced X-ray emission analysis (PIXE), proton microprobe (μ-PIXE), inductively coupled plasma-mass spectrometry (ICP-MS) and X-ray absorption fine structure (XAFS) techniques were used to study the concentration, the chemical species and the source assignment of Pb in the atmospheric aerosol particles of PM 10 . Average values of 369±74. ng/m 3 and 237±45 ng/m 3 of Pb concentration were obtained from the 19 monitor sites in Shanghai in the winter of 2002 and 2003, respectively. Comparing with the earlier data of 466 ng/m 3 in 1997 and 515 ng/m 3 in 2001, it can be observed that the yearly mean lead levels in PM 10 decline significantly. However, it is also found that rather high levels of lead still remain. in the air of Shanghai after the use of unleaded gasoline. The results of XAFS showed that PbCl 2 , PbSO 4 and PbO were probably the main chemical forms of Pb in atmospheric particulate matter. Based on the lead isotope ratios technique and chemical mass balance analysis, the calculation showed that the main emission sources of Pb in the atmosphere of Shanghai were coal combustors

  19. Study of influence of various factors on electrochemical signal of lead in water solutions

    Science.gov (United States)

    Zhikharev, Yu N.; Andrianova, L. I.; Ogudova, E. V.

    2018-05-01

    The conditions for obtaining a reproducible signal of lead in water solutions of indifferent electrolytes on various substrates (working electrodes) for analytical purposes were studied. Attention was also paid to studying the regularities of the initial stage of formation of lead sediments by the method of inversion voltammetry. The possibility of using different working electrodes to obtain stable current-potential curves is shown depending on the conditions of electrolysis, pH of the medium, the electrolysis potential and impurities.

  20. Synthetic biology, inspired by synthetic chemistry.

    Science.gov (United States)

    Malinova, V; Nallani, M; Meier, W P; Sinner, E K

    2012-07-16

    The topic synthetic biology appears still as an 'empty basket to be filled'. However, there is already plenty of claims and visions, as well as convincing research strategies about the theme of synthetic biology. First of all, synthetic biology seems to be about the engineering of biology - about bottom-up and top-down approaches, compromising complexity versus stability of artificial architectures, relevant in biology. Synthetic biology accounts for heterogeneous approaches towards minimal and even artificial life, the engineering of biochemical pathways on the organismic level, the modelling of molecular processes and finally, the combination of synthetic with nature-derived materials and architectural concepts, such as a cellular membrane. Still, synthetic biology is a discipline, which embraces interdisciplinary attempts in order to have a profound, scientific base to enable the re-design of nature and to compose architectures and processes with man-made matter. We like to give an overview about the developments in the field of synthetic biology, regarding polymer-based analogs of cellular membranes and what questions can be answered by applying synthetic polymer science towards the smallest unit in life, namely a cell. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  1. BNL Building 650 lead decontamination and treatment feasibility study. Final report

    International Nuclear Information System (INIS)

    Kalb, P.D.; Cowgill, M.G.; Milian, L.W.

    1995-10-01

    Lead has been used extensively at Brookhaven National Laboratory (BNL) for radiation shielding in numerous reactor, accelerator and other research programs. A large inventory of excess lead (estimated at 410,000 kg) in many shapes and sizes is currently being stored. Due to it's toxicity, lead and soluble lead compounds are considered hazardous waste by the Environmental Protection Agency. Through use at BNL, some of the lead has become radioactive, either by contamination of the surface or through activation by neutrons or deuterons. This study was conducted at BNL's Environmental and Waste Technology Center for the BNL Safety and Environmental Protection Division to evaluate feasibility of various treatment options for excess lead currently being stored. The objectives of this effort included investigating potential treatment methods by conducting a review of the literature, developing a means of screening lead waste to determine the radioactive characteristics, examining the feasibility of chemical and physical decontamination technologies, and demonstrating BNL polyethylene macro-encapsulation as a means of treating hazardous or mixed waste lead for disposal. A review and evaluation of the literature indicated that a number of physical and chemical methods are available for decontamination of lead. Many of these techniques have been applied for this purpose with varying degrees of success. Methods that apply mechanical techniques are more appropriate for lead bricks and sheet which contain large smooth surfaces amenable to physical abrasion. Lead wool, turnings, and small irregularly shaped pieces would be treated more effectively by chemical decontamination techniques. Either dry abrasion or wet chemical methods result in production of a secondary mixed waste stream that requires treatment prior to disposal

  2. Performance comparison of independent component analysis algorithms for fetal cardiac signal reconstruction: a study on synthetic fMCG data

    International Nuclear Information System (INIS)

    Mantini, D; II, K E Hild; Alleva, G; Comani, S

    2006-01-01

    Independent component analysis (ICA) algorithms have been successfully used for signal extraction tasks in the field of biomedical signal processing. We studied the performances of six algorithms (FastICA, CubICA, JADE, Infomax, TDSEP and MRMI-SIG) for fetal magnetocardiography (fMCG). Synthetic datasets were used to check the quality of the separated components against the original traces. Real fMCG recordings were simulated with linear combinations of typical fMCG source signals: maternal and fetal cardiac activity, ambient noise, maternal respiration, sensor spikes and thermal noise. Clusters of different dimensions (19, 36 and 55 sensors) were prepared to represent different MCG systems. Two types of signal-to-interference ratios (SIR) were measured. The first involves averaging over all estimated components and the second is based solely on the fetal trace. The computation time to reach a minimum of 20 dB SIR was measured for all six algorithms. No significant dependency on gestational age or cluster dimension was observed. Infomax performed poorly when a sub-Gaussian source was included; TDSEP and MRMI-SIG were sensitive to additive noise, whereas FastICA, CubICA and JADE showed the best performances. Of all six methods considered, FastICA had the best overall performance in terms of both separation quality and computation times

  3. Enhanced heavy oil recovery for carbonate reservoirs integrating cross-well seismic–a synthetic Wafra case study

    KAUST Repository

    Katterbauer, Klemens

    2015-07-14

    Heavy oil recovery has been a major focus in the oil and gas industry to counter the rapid depletion of conventional reservoirs. Various techniques for enhancing the recovery of heavy oil were developed and pilot-tested, with steam drive techniques proven in most circumstances to be successful and economically viable. The Wafra field in Saudi Arabia is at the forefront of utilizing steam recovery for carbonate heavy oil reservoirs in the Middle East. With growing injection volumes, tracking the steam evolution within the reservoir and characterizing the formation, especially in terms of its porosity and permeability heterogeneity, are key objectives for sound economic decisions and enhanced production forecasts. We have developed an integrated reservoir history matching framework using ensemble based techniques incorporating seismic data for enhancing reservoir characterization and improving history matches. Examining the performance on a synthetic field study of the Wafra field, we could demonstrate the improved characterization of the reservoir formation, determining more accurately the position of the steam chambers and obtaining more reliable forecasts of the reservoir’s recovery potential. History matching results are fairly robust even for noise levels up to 30%. The results demonstrate the potential of the integration of full-waveform seismic data for steam drive reservoir characterization and increased recovery efficiency.

  4. Biosorption of lead ions on biosorbent prepared from plumb shells (spondias mombin): kinetics and equilibrium studies

    International Nuclear Information System (INIS)

    Adeogen, A.I.; Bello, O.S.; Adeboye, M.D.

    2010-01-01

    Plumb shell was used to prepare an adsorbent for biosorption of lead ions in aqueous solution at 25 degree C. The adsorption capacity of the adsorbent at equilibrium was found to increase from 2.8 to 49.0 mg/g with an increase in the initial lead ion concentration from 50 to 200 mg/L. Using the equilibrium and kinetics studies, isotherm of the lead ions on the biosorbent was determined and correlated with common isotherm equations. The equilibrium data for lead ion adsorption fitted well into the Freundlich equation, with a value of 0.76 (R2 = 0.9), with distribution coefficient of 4.90. The biosorption of lead ions on the adsorbent from plumb shells could best be described by the pseudo-second-order equation. The kinetic parameters of this best-fit model were calculated and discussed. (author)

  5. US Competitiveness in Synthetic Biology.

    Science.gov (United States)

    Gronvall, Gigi Kwik

    2015-01-01

    Synthetic biology is an emerging technical field that aims to make biology easier to engineer; the field has applications in strategically important sectors for the US economy. While the United States currently leads in synthetic biology R&D, other nations are heavily investing in order to boost their economies, which will inevitably diminish the US leadership position. This outcome is not entirely negative--additional investments will expand markets--but it is critical that the US government take steps to remain competitive: There are applications from which the US population and economy may benefit; there are specific applications with importance for national defense; and US technical leadership will ensure that US experts have a leading role in synthetic biology governance, regulation, and oversight. Measures to increase competitiveness in S&T generally are broadly applicable for synthetic biology and should be pursued. However, the US government will also need to take action on fundamental issues that will affect the field's development, such as countering anti-GMO (genetically modified organism) sentiments and anti-GMO legislation. The United States should maintain its regulatory approach so that it is the product that is regulated, not the method used to create a product. At the same time, the United States needs to ensure that the regulatory framework is updated so that synthetic biology products do not fall into regulatory gaps. Finally, the United States needs to pay close attention to how synthetic biology applications may be governed internationally, such as through the Nagoya Protocol of the Convention on Biological Diversity, so that beneficial applications may be realized.

  6. Study of lead pollution in air, soil and water samples of Quetta city

    International Nuclear Information System (INIS)

    Khan, M.; Khan, G.M.; Akbar, S.; Panezai, M.A.; Haq, Z.U.

    2011-01-01

    This study briefly presents the collected data of lead pollution in the environment of Quetta City in Balochistan, Pakistan. The samples were collected from different sites. The analysis of lead was carried out in underground water samples, the exhaust of different vehicles, roadside and sewage soils from selected points of Quetta City. The average discharge resulted in deposition by motorcycles (29.12 g/h), cars (44.47 g/h), wagons (176.54 g/h) and buses (141.52 g/h). The maximum deposition was 222.96 g/h from auto-rickshaws. The value for lead in smoke of different vehicles seems quite high when extrapolated to the large number of such vehicles for a longer time. The concentration of lead in roadside soil varied from 73.3 mg/kg (T and T closed colony) to 731.9 mg/kg (Sirki road bus-stop). The average content of lead in sewage soil of City Nala is 1250.6 mg/kg. The level of lead was more than WHO standards for such soils. The lead quantity in all 24 tube- well water samples, was slightly above the WHO standards (10 macro g/L).The results of this study were comparable to similar study in twin cities of Rawalpindi and islamabad. (author)

  7. Determinants of maternal and umbilical blood lead levels: a cross-sectional study, Mosul, Iraq

    Directory of Open Access Journals (Sweden)

    Al-Jomard Raghad A

    2009-03-01

    Full Text Available Abstract Background The populations who are most sensitive to lead exposure from various sources are pregnant women and their newborns. Aiming to explore the presence of correlation between maternal and cord blood lead levels and to identify potential predictors that may influence both levels, the present study has been conducted. Methods A cross-sectional study was conducted covering 350 full terms maternal-newborns pairs from Mosul maternity hospitals. Data were obtained directly from women just before delivery by the use of a detailed questionnaire form. Maternal and umbilical blood lead levels were estimated using LEADCARE® Blood Lead Testing System and Kits. Results A positive significant correlation was found between maternal and cord blood lead values (r = 0.856, p = 0.001. By backward stepwise logistic regression analysis the followings emerged as significant potential predictors of high maternal blood lead: low parity, smoking and Hb level Conclusion Study results have provided baseline data needed to be transformed to decision makers to implement measures to eliminate lead from the environment and protect future generation from its deleterious effects.

  8. Study on corrosion test techniques in lead bismuth eutectic flow. Joint research report in JFY2002

    International Nuclear Information System (INIS)

    Takahashi, Minoru; Sekimoto, Hiroshi

    2003-03-01

    The evaluation of corrosion behaviors of core and structural materials in lead bismuth eutectic is one of the key issues for the utilization of lead bismuth eutectic as a coolant of the primary loops of lead bismuth cooled fast breeder reactors (FBRs) and the intermediate heat transport media of new-type steam generators of the sodium cooled FBRs. The purpose of the present study is to establish corrosion test techniques in lead bismuth eutectic flow. The techniques of steel corrosion test and oxygen control in flowing lead bismuth eutectic, and the technologies of a lead bismuth flow test at high temperature and high velocity were developed through corrosion test using a lead bismuth flow test loop of the Tokyo Institute of Technology in JFY2002. The major results are summarized as follows: (1) Techniques of fabrication, mount and rinse of corrosion specimens, measurement method of weight loss, and SEM/EDX analysis method have been established through lead bismuth corrosion test. (2) Weight losses were measured, corrosion and lead bismuth-adhered layers and eroded parts were observed in two 1000 hr-corrosion tests, and the results were compared with each other for twelve existing steels including ODS, F82H and SUH-3. (3) An oxygen sensor made of zirconia electrolyte structurally resistant to thermal stress and thermal shock was developed and tested in the lead bismuth flow loop. Good performance has been obtained. (4) An oxygen control method by injecting argon and hydrogen mixture gas containing steam into lead bismuth was applied to the lead bismuth flow loop, and technical issues for the development of the oxygen control method were extracted. (5) Technical measures for freezing and leakage of lead bismuth in the flow loop were accumulated. (6) Technical measures for flow rate decrease/blockage due to precipitation of oxide and corrosion products in a low temperature section of the lead bismuth flow loop were accumulated. (7) Electromagnetic flow meters with MI

  9. A Pilot Study of Children’s Blood Lead Levels in Mount Isa, Queensland

    Directory of Open Access Journals (Sweden)

    Donna Green

    2017-12-01

    Full Text Available Mount Isa, Queensland, is one of three Australian cities with significant lead emissions due to nonferrous mining and smelting. Unlike the two other cities with lead mines or smelters, Mount Isa currently has no system of annual, systematic, community-wide blood lead level testing; and testing rates among Indigenous children are low. In previous screenings, this group of children has been shown to have higher average blood lead levels than non-Indigenous children. The first aim of this study was to assess whether parents and children would participate in less invasive, rapid point-of-care capillary testing. The second aim was to measure blood lead levels among a range of children that roughly reflected the percentage of the Indigenous/non-Indigenous population. This pilot study is based on a convenience sample of children between the ages of 12 and 83 months who were recruited to participate by staff at a Children and Family Centre. Over three half-days, 30 children were tested using capillary blood samples and the LeadCare II Point-of-Care testing system. Rapid point-of-care capillary testing was well tolerated by the children. Of 30 children tested, 40% (n = 12 had blood lead levels ≥5 µg/dL and 10% had levels ≥10 µg/dL. The highest blood lead level measured was 17.3 µg/dL. The percentage of children with blood lead levels ≥5 µg/dL was higher among Indigenous children compared to non-Indigenous (64.2% compared to 18.8% as was the geometric mean level (6.5 (95% CI, 4.7, 9.2 versus 2.4 (95% CI, 1.8, 3.1, a statistically significant difference. Though based on a small convenience sample, this study identified 12 children (40% of the sample with blood lead levels ≥5 µg/dL. Due to historical and ongoing heavy metal emissions from mining and smelting in Mount Isa, we recommend a multi-component program of universal blood lead level testing, culturally appropriate follow-up and intervention for children who are identified with blood lead

  10. A Pilot Study of Children's Blood Lead Levels in Mount Isa, Queensland.

    Science.gov (United States)

    Green, Donna; Sullivan, Marianne; Cooper, Nathan; Dean, Annika; Marquez, Cielo

    2017-12-13

    Mount Isa, Queensland, is one of three Australian cities with significant lead emissions due to nonferrous mining and smelting. Unlike the two other cities with lead mines or smelters, Mount Isa currently has no system of annual, systematic, community-wide blood lead level testing; and testing rates among Indigenous children are low. In previous screenings, this group of children has been shown to have higher average blood lead levels than non-Indigenous children. The first aim of this study was to assess whether parents and children would participate in less invasive, rapid point-of-care capillary testing. The second aim was to measure blood lead levels among a range of children that roughly reflected the percentage of the Indigenous/non-Indigenous population. This pilot study is based on a convenience sample of children between the ages of 12 and 83 months who were recruited to participate by staff at a Children and Family Centre. Over three half-days, 30 children were tested using capillary blood samples and the LeadCare II Point-of-Care testing system. Rapid point-of-care capillary testing was well tolerated by the children. Of 30 children tested, 40% ( n = 12) had blood lead levels ≥5 µg/dL and 10% had levels ≥10 µg/dL. The highest blood lead level measured was 17.3 µg/dL. The percentage of children with blood lead levels ≥5 µg/dL was higher among Indigenous children compared to non-Indigenous (64.2% compared to 18.8%) as was the geometric mean level (6.5 (95% CI, 4.7, 9.2) versus 2.4 (95% CI, 1.8, 3.1)), a statistically significant difference. Though based on a small convenience sample, this study identified 12 children (40%) of the sample with blood lead levels ≥5 µg/dL. Due to historical and ongoing heavy metal emissions from mining and smelting in Mount Isa, we recommend a multi-component program of universal blood lead level testing, culturally appropriate follow-up and intervention for children who are identified with blood lead levels ≥5

  11. Determination of 6258-70, a new semi-synthetic taxane, in rat plasma and tissues: Application to the pharmacokinetics and tissue distribution study

    Directory of Open Access Journals (Sweden)

    Simin Zhao

    2016-08-01

    Full Text Available Cancer is the leading cause of death all over the world. Among the chemotherapy drugs, taxanes play an important role in cancer treatment. 6258-70 is a new semi-synthetic taxane which has a broad spectrum of antitumor activity. A fast and reliable high performance liquid chromatography-tandem mass spectrometry (HPLC–MS/MS method was developed for quantification of 6258-70 in rat plasma and tissues in this paper. After extraction by liquid-liquid extraction method with methyl tert-butyl ether, the samples were separated on a Kinetex C18 column (50 mm×2.1 mm, 2.6 µm, Phenomenex, USA within 3 min. The method was fully validated with the matrix effect between 87.7% and 99.5% and the recovery ranging from 80.3% to 90.1%. The intra- and inter-day precisions were less than 9.5% and the accuracy ranged from −3.8% to 6.5%. The reliable method was successfully applied to the pharmacokinetics and tissue distribution studies of 6258-70 after intravenous administration in rats. The pharmacokinetic results indicated that the pharmacokinetic behavior of 6258-70 in rats was in accordance with linear features within tested dosage of 1 to 4 mg/kg, and there was no significant difference between the two genders. The tissue distribution study showed that 6258-70 had an effective penetration, spread widely and rapidly and could cross blood-brain barrier. The results of pharmacokinetics and tissue distribution may provide a guide for future study.

  12. Leaching studies of natural and synthetic titanite, a potential host for wastes from the reprocessing of Canadian nuclear fuel

    International Nuclear Information System (INIS)

    Hayward, P.J.; Doern, F.E.; Cecchetto, E.V.; Mitchell, S.L.

    1983-01-01

    Glass ceramics (i.e., glasses subjected to controlled crystallization) with synthetic titanite as the major crystalline phase are being considered as potential hosts for the radioactive wastes arising from possible future reprocessing of nuclear fuel in Canada. In order to assess the stability of titanite in the anticipated environment of a disposal vault sited 500-1000 m deep within a granitic pluton in the Canadian Shield, leaching experiments have been performed with natural and synthetic titanite, using a synthetic groundwater whose composition is based on findings from a recent borehole-survey. The results are in qualitative agreement with calculations of solution equilibria for titanite and its main alteration products, and indicate that titanite should be stable and suffer no net leaching under anticipated conditions in the vault

  13. Blood lead concentrations in 1-3 year old Lebanese children: a cross-sectional study.

    Science.gov (United States)

    Nuwayhid, Iman; Nabulsi, Mona; Muwakkit, Samar; Kouzi, Sarah; Salem, George; Mikati, Mohamed; Ariss, Majd

    2003-04-15

    Childhood lead poisoning has not made the list of national public health priorities in Lebanon. This study aims at identifying the prevalence and risk factors for elevated blood lead concentrations (B-Pb >or= 100 microg/L) among 1-3 year old children. It also examines the need for universal blood lead screening. This is a cross-sectional study of 281 well children, presenting to the pediatric ambulatory services at the American University of Beirut Medical Center in 1997-98. Blood was drawn on participating children for lead analysis and a structured questionnaire was introduced to mothers asking about social, demographic, and residence characteristics, as well as potential risk factors for lead exposure. Children with B-Pb >or= 100 microg/L were compared to those with B-Pb or= 100 microg/L. Logistic regression analysis showed that elevated B-Pb was associated with paternal manual jobs (odds ratio [OR]: 4.74), residence being located in high traffic areas (OR: 4.59), summer season (OR: 4.39), using hot tap water for cooking (OR: 3.96), exposure to kohl (OR: 2.40), and living in older buildings (OR: 2.01). Lead screening should be offered to high-risk children. With the recent ban of leaded gasoline in Lebanon, emphasis should shift to other sources of exposure in children.

  14. Experimental study on the effect of ingested lead shot on Estuarine crocodiles: significance for Finniss River field studies

    International Nuclear Information System (INIS)

    Hammerton, K.M.

    2002-01-01

    Lead has long been recognised as a cumulative metabolic poison in humans, domestic animals and wildlife. Because of the many industrial activities that have brought about its widespread distribution, lead is ubiquitous in the environment. For example, uranium mining at the Rum Jungle site on the Finniss River, Northern Territory, resulted in contamination of river sediments with lead. Today, lead levels remain at about 250 mg kg-1 of wet river sediment within the immediate vicinity of the mine. Another potential source of lead poisoning in wildlife is the use of lead gunshot for hunting. Mortality in wild waterfowl caused by the ingestion of spent lead shot has been recognised in North America and Europe for over a century. An experimental study was undertaken to assess the above hypothesis on the effects of lead in the environs of crocodiles. The specific effects of lead intoxication arise mainly from the interaction of lead with the enzymatic processes in the haem biosynthetic pathway. One of these enzymes, δ-aminolevulinic acid dehydratase (ALAD), catalyses the condensation of two molecules of aminolevulinic acid to produce the pyrrole, porphobilinogen, the building block of the haem molecule. ALAD is a metalloenzyme requiring zinc for activity and is inhibited by lead displacing the essential zinc. This inhibition of ALAD by lead has been used as a specific biomarker for lead poisoning in fish, birds and mammals. An assay system was developed for the measurement of ALAD activity in crocodilian blood. It was found that ALAD was inhibited by up to 90% during the first week after exposure of the crocodiles to lead shot. There was an inverse correlation between BPb and ALAD activity throughout the 42 week experimental period. BPb concentrations greater than 100 mg dL-1 produced significant inhibition of ALAD. The results indicated that ALAD inhibition could be used as a specific biomarker of lead toxicity in crocodiles

  15. A Comparative Outcome Study of Hamstring Versus Tibialis Anterior and Synthetic Grafts for Deltoid to Triceps Transfers.

    Science.gov (United States)

    Dunn, Jennifer A; Mohammed, Khalid D; Beadel, Gordon P; Rothwell, Alastair G; Simcock, Jeremy W

    2017-10-01

    To assess elbow extension strength and complications after deltoid-triceps transfers using hamstring tendon graft compared with tibialis anterior and synthetic tendon grafts. A retrospective review of deltoid-triceps transfers in patients with tetraplegia performed between 1983 and 2014. Seventy-five people (136 arms) had surgery performed, with the majority undergoing simultaneous bilateral surgery (n = 61; 81%). Tibialis anterior tendon grafts were used in 68 arms, synthetic grafts in 23 arms, and hamstring tendon grafts in 45 arms. The average age at surgery was 31 years. Sixty-three arms (46%) were assessed between 12 and 24 months after surgery. Seventy percent of the group (n = 54) were able to extend their elbow against gravity (grade 3 of 5 or greater) following surgery. Seventy-nine percent of those with hamstring grafts achieved grade 3 of 5 or more compared with 77% with tibialis anterior and 33% with synthetic grafts. There was a statistically significant difference in postsurgery elbow extension between the tibialis anterior group and the synthetic graft group and the hamstring and the synthetic graft group but not between the tibialis anterior and the hamstring group. Complications occurred in 19 arms (14%), the majority occurring immediately after surgery and associated with the wounds. The remaining complications were with the synthetic graft group in which dehiscence of the proximal attachment occurred in 30% of the arms. Autologous tendon grafting is associated with achievement of antigravity elbow extension in a greater proportion of individuals than with prosthetic grafting. Therapeutic IV. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  16. Plant synthetic biology.

    Science.gov (United States)

    Liu, Wusheng; Stewart, C Neal

    2015-05-01

    Plant synthetic biology is an emerging field that combines engineering principles with plant biology toward the design and production of new devices. This emerging field should play an important role in future agriculture for traditional crop improvement, but also in enabling novel bioproduction in plants. In this review we discuss the design cycles of synthetic biology as well as key engineering principles, genetic parts, and computational tools that can be utilized in plant synthetic biology. Some pioneering examples are offered as a demonstration of how synthetic biology can be used to modify plants for specific purposes. These include synthetic sensors, synthetic metabolic pathways, and synthetic genomes. We also speculate about the future of synthetic biology of plants. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Synthetic Cathinones ("Bath Salts")

    Science.gov (United States)

    ... Alcohol Club Drugs Cocaine Fentanyl Hallucinogens Inhalants Heroin Marijuana MDMA (Ecstasy/Molly) Methamphetamine Opioids Over-the-Counter Medicines Prescription Medicines Steroids (Anabolic) Synthetic Cannabinoids (K2/Spice) Synthetic Cathinones (Bath Salts) Tobacco/ ...

  18. Leading Short-Term Study Abroad Courses: Motivations and Outcomes for Community College Faculty

    Science.gov (United States)

    Hull, Melinda Leigh

    2013-01-01

    This case study explored faculty motivations for choosing to lead short-term study abroad courses and the personal and professional outcomes of the undertaking as reported by the faculty members themselves. This study also identified specific instances of internationalized practice in the development and implementation of the course. Three faculty…

  19. Synthetic Scenarios from CMIP5 Model Simulations for Climate Change Impact Assessments in Managed Ecosystems and Water Resources: Case Study in South Asian Countries

    Science.gov (United States)

    Anandhi, A.; Omani, N.; Chaubey, I.; Horton, R.; Bader, D.; Nanjundiah, R. S.

    2017-01-01

    Increasing population, urbanization, and associated demand for food production compounded by climate change and variability have important implications for the managed ecosystems and water resources of a region. This is particularly true for south Asia, which supports one quarter of the global population, half of whom live below the poverty line. This region is largely dependent on monsoon precipitation for water. Given the limited resources of the developing countries in this region, the objective of our study was to empirically explore climate change in south Asia up to the year 2099 using monthly simulations from 35 global climate models (GCMs) participating in the fifth phase of the Climate Model Inter-comparison Project (CMIP5) for two future emission scenarios (representative concentration pathways RCP4.5 and RCP8.5) and provide a wide range of potential climate change outcomes. This was carried out using a three-step procedure: calculating the mean annual, monsoon, and non-monsoon precipitation and temperatures; estimating the percent change from historical conditions; and developing scenario funnels and synthetic scenarios. This methodology was applied for the entire south Asia region; however, the percent change information generated at 1.5deg grid scale can be used to generate scenarios at finer spatial scales. Our results showed a high variability in the future change in precipitation (-23% to 52%, maximum in the non-monsoon season) and temperature (0.8% to 2.1%) in the region. Temperatures in the region consistently increased, especially in the Himalayan region, which could have impacts including a faster retreat of glaciers and increased floods. It could also change rivers from perennial to seasonal, leading to significant challenges in water management. Increasing temperatures could further stress groundwater reservoirs, leading to withdrawal rates that become even more unsustainable. The high precipitation variability (with higher propensity for

  20. X-band EPR studies of ferroelectric lead titanate (PT), piezoelectric lead magnesium niobate (PMN), and PMN/PT powders at 10 and 85 K

    International Nuclear Information System (INIS)

    Huang, J.; Fitzgerald, J.J.; Chasteen, N.D.

    1998-01-01

    X-band EPR spectra of lead titanate (PT) and lead magnesium niobate (PMN) powders prepared by different synthetic methods and a PMN/PT powder of the composition 0.9 PMN/01 PT were obtained at 85 and 10 K. Several EPR signals due to adventitious Fe 3+ ion impurities, a signal due to the Ti 3+ ion, and a signal due to the Pb 3+ ion are observed for PT, PMN, and PMN/PT powders. The EPR signals observed at g = 2.0 and 6.0 are assigned to Fe 3+ ions in the B-sites of the perovskite lattice structure of lad titanate with axial symmetry. The EPR signals observed at g = 1.99 and 4.25 are assigned to Fe 3+ ions in the B-sites of the perovskite lattice structure of PMN and 0.9 PMN/0.1 PT materials with cubic and rhombic symmetries, respectively. The sharp EPR signal observed at g = 1.94 is assigned to Ti 3= ion for PT and 0.9 PMN/0.1 PT powders. In addition, a broader EPR signal at g = 2.28--2.30 for PMN obtained by the molten salt method is assigned to axial Pb 3+ ion sites in this PMN material. EPR results obtained here for the e 3+ ions in the B-sites of the PMN materials, in particular, suggest that both cubic and rhombic symmetry sites corresponding to a range of Nb(OMg) x (ONb) 6-x site configurations exist in the PMN. These EPR results indicate that PMN likely exists with partial B-site cation (Mg/Nb) ordering in the perovskite lattice structure

  1. Recent studies of lead neurotoxicity in children: old metal, new questions

    Directory of Open Access Journals (Sweden)

    David C. Bellinger

    2011-09-01

    Full Text Available Many times in the history of lead toxicology the view has prevailed that „the problem” has been solved, and that exposure to lead is no longer a major public health concern. Each time, additional research has demonstrated the prematurity of this judgment. In the last decade, an extraordinary number of new studies have illustrated that „the problem” remains, and that it has dimensions never before considered. Children’s intelligence has traditionally been considered to be the most sensitive endpoint and used as the basis for risk assessment and standard setting. For IQ, the dose-effect relationship appears to be supra-linear, with greater deficits per μg/L increment below than above 100 μg/L. Recent studies have found that greater lead exposure in early childhood is also associated with a wide variety of other outcomes, with some associations evident at biomarker levels comparable to those at which IQ deficits are observed. Among these endpoints are poorer academic achievement, ADHD, conduct disorder, and antisocial behavior. In animals, early life lead exposure has been implicated in neurodegenerative disorders later in life, perhaps via epigenetic mechanisms. Studies employing neuroimaging modalities such as volumetric, diffusion tensor, and functional MRI are providing insights into the neural bases of the cognitive impairments associated with greater lead exposure. Several recent risk assessments (e.g., EFSA, JECFA have concluded that research has yet to identify a threshold level below which lead can be considered „safe”.

  2. Contribution to the study of the geophysical behaviour of lead-210 by application of alpha spectrometry

    International Nuclear Information System (INIS)

    Nezami, M.

    1965-06-01

    A study of the changes in the lead-210 contents of rain-water and of water produced by melting polar ice has required the development of a method for dosing lead-210, an α emitter. This method is 40 times more sensitive than that which measures the lead-210 by bismuth-210, a (β emitter. The first part of the report presents the study of a spectrometry using semiconductor detectors; a catalogue of a spectra shows the advantages of this method. In the second part will be found at first a new chemical separation method for polonium-210 and the results obtained with this method. The main results obtained on the geophysical behaviour of lead-210 are the following: - the monthly lead-210 and polonium-210 contents in rain water are approximately constant with time. - in the Gif-sur-Yvette region, the clean-up by 'dry fall-out' can attain 40 to 50 per cent of the total fall-out. - a study of Antarctic ice samples makes it possible to determine an annual accumulation rate equivalent to 13.8 cm of water and to show discrepancies in the periodic concentrations which correspond to the latest maxima of solar activity. - a balance is drawn up between the radon produced by the continents and the lead-210 fall-out. (author) [fr

  3. FTIR imaging in diffusion studies: CO2 and H2O in a synthetic sector-zoned beryl

    Directory of Open Access Journals (Sweden)

    Giancarlo eDella Ventura

    2015-06-01

    Full Text Available In this work we investigate the strongly inhomogeneous distribution of CO2 and H2O in a synthetic beryl having a peculiar hourglass zoning of Cr due to the crystal growth. The sample was treated at 800°C, 500 MPa, in a CO2-rich atmosphere. High-resolution FESEM images revealed that the hourglass boundary is not correlated to physical discontinuities, at least at the scale of tens of nanometers. Polarized FPA-FTIR imaging, on the other side, revealed that the chemical zoning acts as a fast pathway for carbon dioxide diffusion, a feature never observed so far in minerals. The hourglass zone boundary may be thus considered as a structural defect possibly due to the mismatch induced by the different growth rates of each sector. High-resolution synchrotron-light FTIR imaging, in addition, also allows enhancement of CO2 diffusion along the hourglass boundary to be distinguished from diffusion along fractures in the grain. Therefore, FTIR imaging provides evidence that different diffusion mechanisms may locally combine, suggesting that the distribution of the target molecules needs to be be carefully characterized in experimental studies. This piece of information is mandatory when the study is aimed at extracting diffusion coefficients from analytical profiles. Combination of TOF-SIMS and FPA data shows a significant depletion of type II H2O along the hourglass boundary, indicating that water diffusion could be controlled by the distribution of alkali cations within channels, coupled to a plug effect of CO2.

  4. Blood lead levels, iron metabolism gene polymorphisms and homocysteine: a gene-environment interaction study.

    Science.gov (United States)

    Kim, Kyoung-Nam; Lee, Mee-Ri; Lim, Youn-Hee; Hong, Yun-Chul

    2017-12-01

    Homocysteine has been causally associated with various adverse health outcomes. Evidence supporting the relationship between lead and homocysteine levels has been accumulating, but most prior studies have not focused on the interaction with genetic polymorphisms. From a community-based prospective cohort, we analysed 386 participants (aged 41-71 years) with information regarding blood lead and plasma homocysteine levels. Blood lead levels were measured between 2001 and 2003, and plasma homocysteine levels were measured in 2007. Interactions of lead levels with 42 genotyped single-nucleotide polymorphisms (SNPs) in five genes ( TF , HFE , CBS , BHMT and MTR ) were assessed via a 2-degree of freedom (df) joint test and a 1-df interaction test. In secondary analyses using imputation, we further assessed 58 imputed SNPs in the TF and MTHFR genes. Blood lead concentrations were positively associated with plasma homocysteine levels (p=0.0276). Six SNPs in the TF and MTR genes were screened using the 2-df joint test, and among them, three SNPs in the TF gene showed interactions with lead with respect to homocysteine levels through the 1-df interaction test (plead levels. Blood lead levels were positively associated with plasma homocysteine levels measured 4-6 years later, and three SNPs in the TF gene modified the association. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  5. Effects of Synthetic Speech Output on Requesting and Natural Speech Production in Children with Autism: A Preliminary Study

    Science.gov (United States)

    Schlosser, Ralf W.; Sigafoos, Jeff; Luiselli, James K.; Angermeier, Katie; Harasymowyz, Ulana; Schooley, Katherine; Belfiore, Phil J.

    2007-01-01

    Requesting is often taught as an initial target during augmentative and alternative communication intervention in children with autism. Speech-generating devices are purported to have advantages over non-electronic systems due to their synthetic speech output. On the other hand, it has been argued that speech output, being in the auditory…

  6. Enhancement of synthetic jets by means of an integrated valve-less pump, Part II: Numerical and experimental studies

    Czech Academy of Sciences Publication Activity Database

    Trávníček, Zdeněk; Tesař, Václav; Wang, A.

    2005-01-01

    Roč. 125, č. 1 (2005), s. 50-58 ISSN 0924-4247 R&D Projects: GA AV ČR(CZ) KSK2076106 Institutional research plan: CEZ:AV0Z20760514 Keywords : periodic jets * synthetic jets Subject RIV: BK - Fluid Dynamics Impact factor: 1.363, year: 2005

  7. 2,6-Lutidine-isatinecate, a semi-synthetic pyrrolizidine alkaloid: X-ray and N. M. R. studies

    Energy Technology Data Exchange (ETDEWEB)

    Drewes, S.E.; Field, J.S.; Pitchford, A.T.; Van Rooyen, P.H.; Dillen, J.L.M.

    1985-09-01

    A semi-synthetic pyrrolizidine alkaloid has been prepared from a necic acid and a pyridine base moiety. N.M.R. and X-ray analyses of this compound were carried out in order to establish the relationship between the structure and chemical shift.

  8. Synthetic tsunami waveform catalogs with kinematic constraints

    Science.gov (United States)

    Baptista, Maria Ana; Miranda, Jorge Miguel; Matias, Luis; Omira, Rachid

    2017-07-01

    In this study we present a comprehensive methodology to produce a synthetic tsunami waveform catalogue in the northeast Atlantic, east of the Azores islands. The method uses a synthetic earthquake catalogue compatible with plate kinematic constraints of the area. We use it to assess the tsunami hazard from the transcurrent boundary located between Iberia and the Azores, whose western part is known as the Gloria Fault. This study focuses only on earthquake-generated tsunamis. Moreover, we assume that the time and space distribution of the seismic events is known. To do this, we compute a synthetic earthquake catalogue including all fault parameters needed to characterize the seafloor deformation covering the time span of 20 000 years, which we consider long enough to ensure the representability of earthquake generation on this segment of the plate boundary. The computed time and space rupture distributions are made compatible with global kinematic plate models. We use the tsunami empirical Green's functions to efficiently compute the synthetic tsunami waveforms for the dataset of coastal locations, thus providing the basis for tsunami impact characterization. We present the results in the form of offshore wave heights for all coastal points in the dataset. Our results focus on the northeast Atlantic basin, showing that earthquake-induced tsunamis in the transcurrent segment of the Azores-Gibraltar plate boundary pose a minor threat to coastal areas north of Portugal and beyond the Strait of Gibraltar. However, in Morocco, the Azores, and the Madeira islands, we can expect wave heights between 0.6 and 0.8 m, leading to precautionary evacuation of coastal areas. The advantages of the method are its easy application to other regions and the low computation effort needed.

  9. Lead Pollution Remanence in an Urban River System: A multi-scale temporal and spatial study

    Directory of Open Access Journals (Sweden)

    Ayrault S.

    2013-04-01

    Full Text Available This work aims at studying the fate of sediments contaminated with tetraethyl Pb from leaded gasoline using a two-dimension upscaling approach, from a small urban subcatchment, the Orge River (900 km2 to the whole Seine River basin (64700 km2, in France. In France, the leaded gasoline reduction started in 1986 and leaded gasoline was completely banned after 2000. This work aims at assessing whether the ban of leaded gasoline is related to changes in Pb contamination sources of these river suspended sediment particles (SPM and bed sediment. Sediment cores and samples collected in the course of previous research projects of the Seine River contamination were used as temporal archives. The study of the isotopic lead ratio showed the fast decrease of the contamination of urban river suspended particulate matter due to the “gasoline” lead source from 2000 to 2011. This source mostly disappeared in the SPM from the Seine River basin that includes urban areas but also agricultural and industrial activities. Nevertheless, it is still present in the small urban catchment of the Orge River. The results on bed sediments showed a different pattern, where the “gasoline” source is still active in densely populated areas, either in the Seine River in the 20 km downstream Paris, or along the Orge River.

  10. Experimental studies on the distribution, retention and excretion of lead with labeled lead nitrate in guinea pigs

    International Nuclear Information System (INIS)

    Mukai, Tetsuro

    1981-01-01

    Labeled lead ( 210 Pb) nitrate was administered once to male, mature guinea pigs by three routes of i.v. (intravenous injection), intratracheal and oral admin. (administration). Uptake of 210 Pb by whole blood (dose %) reached its peak one day after administration in the case of i.v. and intratracheal admin., the peak value being 5.0% and 3.4% respectively. On the 5th day, the uptake reduced to about 1/5 of the initial dose and the decrease was rapid thereafter. In the case of oral admin. the uptake on the first day was low at 0.19%, kept increasing until the 15th day after administration and decreased thereafter. In any mode of administration the uptake by the bone system of 210 Pb showed a high value from the beginning, and a tendency to accumulate was found thereafter. In any mode of administration the uptake by the liver of 210 Pb was high initially, but then started to decrease rather rapidly. As to the skin and hair, the uptake ratio was low but an appreciable uptake of 210 Pb was noted in terms of dose %, while uptake of 210 Pb was invariably low in the soft tissues investigated except for the spleen in which 210 Pb uptake ratio was relatively high in any mode of administration, this being a lasting tendency. The excretion of 210 Pb in every mode of administration was shown as total of exponential functions. Total excretion of 210 Pb in 30 days was, in the case of i.v., 19.4% into urine and 37.4% into feces, in the case of intratracheal admin., 22.0% into urine and 58.1% into feces and in the case of oral admin., 7.1% into urine and 77.0% into feces. Accumulation in the body of 210 Pb 30 days after admin., namely i.v., intratracheal and oral admin., were 42.9%, 20.2% and 15.1% respectively. The highest was the uptake by the bone system. (author)

  11. A Study of the Central Auditory Function in Stutters by Masking Level Difference and Synthetic Sentence Identification Tests

    Directory of Open Access Journals (Sweden)

    Afsaneh Rajab

    2007-06-01

    Full Text Available Background and Aim: There are evidences that indicate a relationship between auditory processing disor¬ders and stuttering,¬ and any disorder in the central auditory function can be at least one of the underly¬ing causes of stuttering. Even though, using the most state of the art radiographic technologies, i.e. MRI, no definitive answer has been given in relative to this question. In this research, using Mask-ing Level Difference (MLD and Synthetic Sentence Identification (SSI tests, the central auditory func¬tion of stutters and normal group was evaluated.Materials and Methods: In this study was analytic cross-sectional, fifteen male patients with stutter-ing and 15 male normal cases with the age range from 16 to 40 years (average age 26.78 year were evalu¬ated. SSI-ICM, SSI-CCM and MLD tests were performed. The results were compared in both groups.Results: Although stutterers mean MLD was less than that of normal group, the different was not signifi¬cant between stutters and normal group in SSI test in right ear at negative MCRs. There was a signifi¬cant difference in ICM state, but in CCM state, there was no significant difference between the aver¬age score of two groups in various MCRs.Conclusion: The findings of this research is compatible with those of similar researches about the SSI test and the pattern of results, probably indicates a partial dysfunction of brainstem in some of the stutters.

  12. Improvement of Atrophic Acne Scars in Skin of Color Using Topical Synthetic Epidermal Growth Factor (EGF) Serum: A Pilot Study.

    Science.gov (United States)

    Stoddard, Marie Alexia; Herrmann, Jennifer; Moy, Lauren; Moy, Ronald

    2017-04-01

    BACKGROUND: Atrophic scarring in skin of color is a common, permanent, and distressing result of uncontrolled acne vulgaris. Ablative lasers and chemical peels are frequently used to improve the appearance of atrophic scars, primarily through the stimulation of collagen and elastin; however, these treatment modalities are associated with risks, such as dyspigmentation and hypertrophic scarring, especially in patients with darker skin. OBJECTIVE: We evaluated the efficacy of topically applied synthetic epidermal growth factor (EGF) serum in reducing the appearance of atrophic acne scars in skin of color. METHODS: A single-center clinical trial was performed on twelve healthy men and women (average age 32.5) with Fitzpatrick Type IV-V skin and evidence of facial grade II-IV atrophic acne scars. Subjects applied topical EGF serum to the full-face twice daily for 12 weeks. Scar improvement was investigated at each visit using an Investigator Global Assessment (IGA), a Goodman grade, clinical photography, and patient self-assessment. RESULTS: Eleven subjects completed the trial. Compared to baseline, there was an improvement in mean IGA score from 3.36 (SEM = 0.15) to 2.18 (SEM = 0.33). Mean Goodman grade was reduced from 2.73 (SEM = 0.19) to 2.55 (SEM = 0.21). Of the eleven pairs of before and after photographs, nine were correctly chosen as the post-treatment image by a blind investigator. On self-assessment, 81% reported a "good" to "excellent" improvement in their scars compared to baseline (P = 0.004). CONCLUSION: Topical EGF may improve the appearance of atrophic acne scars in skin of color. Additional, larger studies should be conducted to better characterize improvement. J Drugs Dermatol. 2017;16(4):322-326..

  13. The Physical Significance of the Synthetic Running Correlation Coefficient and Its Applications in Oceanic and Atmospheric Studies

    Science.gov (United States)

    Zhao, Jinping; Cao, Yong; Wang, Xin

    2018-06-01

    In order to study the temporal variations of correlations between two time series, a running correlation coefficient (RCC) could be used. An RCC is calculated for a given time window, and the window is then moved sequentially through time. The current calculation method for RCCs is based on the general definition of the Pearson product-moment correlation coefficient, calculated with the data within the time window, which we call the local running correlation coefficient (LRCC). The LRCC is calculated via the two anomalies corresponding to the two local means, meanwhile, the local means also vary. It is cleared up that the LRCC reflects only the correlation between the two anomalies within the time window but fails to exhibit the contributions of the two varying means. To address this problem, two unchanged means obtained from all available data are adopted to calculate an RCC, which is called the synthetic running correlation coefficient (SRCC). When the anomaly variations are dominant, the two RCCs are similar. However, when the variations of the means are dominant, the difference between the two RCCs becomes obvious. The SRCC reflects the correlations of both the anomaly variations and the variations of the means. Therefore, the SRCCs from different time points are intercomparable. A criterion for the superiority of the RCC algorithm is that the average value of the RCC should be close to the global correlation coefficient calculated using all data. The SRCC always meets this criterion, while the LRCC sometimes fails. Therefore, the SRCC is better than the LRCC for running correlations. We suggest using the SRCC to calculate the RCCs.

  14. Interferometric synthetic aperture radar study of Okmok volcano, Alaska, 1992-2003: Magma supply dynamics and postemplacement lava flow deformation

    Science.gov (United States)

    Lu, Z.; Masterlark, Timothy; Dzurisin, Daniel

    2005-01-01

    Okmok volcano, located in the central Aleutian arc, Alaska, is a dominantly basaltic complex topped with a 10-km-wide caldera that formed circa 2.05 ka. Okmok erupted several times during the 20th century, most recently in 1997; eruptions in 1945, 1958, and 1997 produced lava flows within the caldera. We used 80 interferometric synthetic aperture radar (InSAR) images (interferograms) to study transient deformation of the volcano before, during, and after the 1997 eruption. Point source models suggest that a magma reservoir at a depth of 3.2 km below sea level, located beneath the center of the caldera and about 5 km northeast of the 1997 vent, is responsible for observed volcano-wide deformation. The preeruption uplift rate decreased from about 10 cm yr−1 during 1992–1993 to 2 ∼ 3 cm yr−1 during 1993–1995 and then to about −1 ∼ −2 cm yr−1 during 1995–1996. The posteruption inflation rate generally decreased with time during 1997–2001, but increased significantly during 2001–2003. By the summer of 2003, 30 ∼ 60% of the magma volume lost from the reservoir in the 1997 eruption had been replenished. Interferograms for periods before the 1997 eruption indicate consistent subsidence of the surface of the 1958 lava flows, most likely due to thermal contraction. Interferograms for periods after the eruption suggest at least four distinct deformation processes: (1) volcano-wide inflation due to replenishment of the shallow magma reservoir, (2) subsidence of the 1997 lava flows, most likely due to thermal contraction, (3) deformation of the 1958 lava flows due to loading by the 1997 flows, and (4) continuing subsidence of 1958 lava flows buried beneath 1997 flows. Our results provide insights into the postemplacement behavior of lava flows and have cautionary implications for the interpretation of inflation patterns at active volcanoes.

  15. Developing a synthetic national population to investigate the impact of different cardiovascular disease risk management strategies: A derivation and validation study.

    Science.gov (United States)

    Knight, Josh; Wells, Susan; Marshall, Roger; Exeter, Daniel; Jackson, Rod

    2017-01-01

    Many national cardiovascular disease (CVD) risk factor management guidelines now recommend that drug treatment decisions should be informed primarily by patients' multi-variable predicted risk of CVD, rather than on the basis of single risk factor thresholds. To investigate the potential impact of treatment guidelines based on CVD risk thresholds at a national level requires individual level data representing the multi-variable CVD risk factor profiles for a country's total adult population. As these data are seldom, if ever, available, we aimed to create a synthetic population, representing the joint CVD risk factor distributions of the adult New Zealand population. A synthetic population of 2,451,278 individuals, representing the actual age, gender, ethnicity and social deprivation composition of people aged 30-84 years who completed the 2013 New Zealand census was generated using Monte Carlo sampling. Each 'synthetic' person was then probabilistically assigned values of the remaining cardiovascular disease (CVD) risk factors required for predicting their CVD risk, based on data from the national census national hospitalisation and drug dispensing databases and a large regional cohort study, using Monte Carlo sampling and multiple imputation. Where possible, the synthetic population CVD risk distributions for each non-demographic risk factor were validated against independent New Zealand data sources. We were able to develop a synthetic national population with realistic multi-variable CVD risk characteristics. The construction of this population is the first step in the development of a micro-simulation model intended to investigate the likely impact of a range of national CVD risk management strategies that will inform CVD risk management guideline updates in New Zealand and elsewhere.

  16. Neuropsychological studies in children with elevated tooth-lead concentrations. II. Extended study

    Energy Technology Data Exchange (ETDEWEB)

    Winneke, G; Kraemer, U; Brockhaus, A; Ewers, U; Kujanek, G; Lechner, H; Janke, W

    1983-01-01

    Results from neuropsychological tests, collected under double-blind-precautions, were evaluated for 115 schoolage children (mean age: 9.4 years) living in a lead smelter area (Stolberg, FRG). Tooth-lead concentrations (PbT) from shed incisor teeth as measures of longtime lead-exposure were available for these children (mean . 6.16 ppm; range: 1.9-38.5 ppm), and for 83 of them blood-lead concentrations (PbB) were available as well (mean . 14.3 micrograms/dl; range: 6.8-33.8 micrograms/dl). The following functional capacities were tested: intelligence (German WISC), perceptual-motor integration (Goettinger Formreproduktionstest . GFT, Diagnosticum for Cerebralschaedigung . DCS), reaction performance (Wiener Determinationsgeraet), finger-wrist tapping-speed, and repetitive cancellation-performance (Differentieller Leistungstest). In addition standardized behavior ratings were obtained by the examiners, the mothers, and the teachers. Multiple stepwise regression-analysis (forced solution) was calculated for outcome-variables and Pb-tooth, including age, sex, duration of labor, and socio-hereditary background as covariates. The results are discussed within the framework of attention-deficit disorder, and compared to neurobehavioral Pb-effects from animal-experiments, which provide suggestive evidence for a causal relationship between developmental lead-exposure and certain neurobehavioral deficits.

  17. Studies of corrosion resistance of Japanese steels in liquid lead-bismuth

    International Nuclear Information System (INIS)

    Kamata, Kin-ya; Ono, Hiroshi; Kitano, Teruaki; Ono, Mikinori

    2003-01-01

    Liquid lead-bismuth has attractive characteristics as a coolant in future fast reactors and Accelerator Driven Sub-critical Systems (ADS) applications. The corrosion behavior of structural materials in lead-bismuth eutectic is one of key problems in developing nuclear power plants and installations using lead-bismuth coolant. Our experiences with heat exchangers using liquid lead-bismuth and the results of corrosion tests of Japanese steels are reported in this paper. A series of corrosion tests was carried out in collaboration with the Institute of Physics and Power Engineering (IPPE). Test specimens of various Japanese steels were exposed in a non-isothermal forced circulation loop. The influence of maximum temperature and oxygen content in lead bismuth were chosen for study as the primary causes of corrosion in Japanese steels. After the corrosion tests, corrosion behavior was analyzed by visual inspection, measurement of weight loss and metallurgical examination of the microstructure of the corroded zone. The corrosion mechanism in liquid lead bismuth is discussed on the basis of the metallurgical examination of the corroded zone. (author)

  18. Study of x-ray medical mitigation with lead and aluminium shield

    International Nuclear Information System (INIS)

    Malheiros, Emiliane A.; Ramos, Roberto Paulo B.; Oliveira, Ezequias Fernandes

    2016-01-01

    In this work, lead and aluminum as shielding materials and their variations in the spectra emitted by the X-ray equipment through the use of a computer program that determines the photon fluence . The study of the primary beam for power spectra used in the practice of diagnostic radiology allows you to analyze data representative of the average transmission and fluency for the studied materials. So we seek to analyze the transmission curves of lead and aluminum, as well as its influence on the thickness of shielding and changing the radiation spectrum characteristics X in the transmission of photons. (author)

  19. Space Synthetic Biology Project

    Science.gov (United States)

    Howard, David; Roman, Monsi; Mansell, James (Matt)

    2015-01-01

    Synthetic biology is an effort to make genetic engineering more useful by standardizing sections of genetic code. By standardizing genetic components, biological engineering will become much more similar to traditional fields of engineering, in which well-defined components and subsystems are readily available in markets. Specifications of the behavior of those components and subsystems can be used to model a system which incorporates them. Then, the behavior of the novel system can be simulated and optimized. Finally, the components and subsystems can be purchased and assembled to create the optimized system, which most often will exhibit behavior similar to that indicated by the model. The Space Synthetic Biology project began in 2012 as a multi-Center effort. The purpose of this project was to harness Synthetic Biology principals to enable NASA's missions. A central target for application was to Environmental Control & Life Support (ECLS). Engineers from NASA Marshall Space Flight Center's (MSFC's) ECLS Systems Development Branch (ES62) were brought into the project to contribute expertise in operational ECLS systems. Project lead scientists chose to pursue the development of bioelectrochemical technologies to spacecraft life support. Therefore, the ECLS element of the project became essentially an effort to develop a bioelectrochemical ECLS subsystem. Bioelectrochemical systems exploit the ability of many microorganisms to drive their metabolisms by direct or indirect utilization of electrical potential gradients. Whereas many microorganisms are capable of deriving the energy required for the processes of interest (such as carbon dioxide (CO2) fixation) from sunlight, it is believed that subsystems utilizing electrotrophs will exhibit smaller mass, volume, and power requirements than those that derive their energy from sunlight. In the first 2 years of the project, MSFC personnel conducted modeling, simulation, and conceptual design efforts to assist the

  20. Blood Lead Concentrations in 1–3 Year Old Lebanese Children: A Cross-sectional study

    Directory of Open Access Journals (Sweden)

    Salem George

    2003-04-01

    Full Text Available Abstract Background Childhood lead poisoning has not made the list of national public health priorities in Lebanon. This study aims at identifying the prevalence and risk factors for elevated blood lead concentrations (B-Pb ≥ 100 μg/L among 1–3 year old children. It also examines the need for universal blood lead screening. Methods This is a cross-sectional study of 281 well children, presenting to the pediatric ambulatory services at the American University of Beirut Medical Center in 1997–98. Blood was drawn on participating children for lead analysis and a structured questionnaire was introduced to mothers asking about social, demographic, and residence characteristics, as well as potential risk factors for lead exposure. Children with B-Pb ≥ 100 μg/L were compared to those with B-Pb Results Mean B-Pb was 66.0 μg/L (median 60.0; range 10–160; standard deviation 26.3 with 39 (14% children with B-Pb ≥ 100 μg/L. Logistic regression analysis showed that elevated B-Pb was associated with paternal manual jobs (odds ratio [OR]: 4.74, residence being located in high traffic areas (OR: 4.59, summer season (OR: 4.39, using hot tap water for cooking (OR: 3.96, exposure to kohl (OR: 2.40, and living in older buildings (OR: 2.01. Conclusion Lead screening should be offered to high-risk children. With the recent ban of leaded gasoline in Lebanon, emphasis should shift to other sources of exposure in children.

  1. Blood Lead Concentrations in 1–3 Year Old Lebanese Children: A Cross-sectional study

    Science.gov (United States)

    Nuwayhid, Iman; Nabulsi, Mona; Muwakkit, Samar; Kouzi, Sarah; Salem, George; Mikati, Mohamed; Ariss, Majd

    2003-01-01

    Background Childhood lead poisoning has not made the list of national public health priorities in Lebanon. This study aims at identifying the prevalence and risk factors for elevated blood lead concentrations (B-Pb ≥ 100 μg/L) among 1–3 year old children. It also examines the need for universal blood lead screening. Methods This is a cross-sectional study of 281 well children, presenting to the pediatric ambulatory services at the American University of Beirut Medical Center in 1997–98. Blood was drawn on participating children for lead analysis and a structured questionnaire was introduced to mothers asking about social, demographic, and residence characteristics, as well as potential risk factors for lead exposure. Children with B-Pb ≥ 100 μg/L were compared to those with B-Pb < 100 μg/L. Results Mean B-Pb was 66.0 μg/L (median 60.0; range 10–160; standard deviation 26.3) with 39 (14%) children with B-Pb ≥ 100 μg/L. Logistic regression analysis showed that elevated B-Pb was associated with paternal manual jobs (odds ratio [OR]: 4.74), residence being located in high traffic areas (OR: 4.59), summer season (OR: 4.39), using hot tap water for cooking (OR: 3.96), exposure to kohl (OR: 2.40), and living in older buildings (OR: 2.01). Conclusion Lead screening should be offered to high-risk children. With the recent ban of leaded gasoline in Lebanon, emphasis should shift to other sources of exposure in children. PMID:12780938

  2. One century of studies on lead poisoning in papers published in La Medicina del Lavoro.

    Science.gov (United States)

    Alessio, L; Cortesi, I; Materzanini, P; Barenghi, M

    2000-09-01

    One century of papers published in the Italian journal of occupational medicine, La Medicina del Lavoro, shows clearly that the study of lead is an exemplary topic for occupational physicians, enabling them to observe the evolution of research in the field of occupational health. The numerous pathological features of lead poisoning, doctors' successive therapeutic responses, and their gradual development of preventive techniques, form a paradigm that has subsequently been applied to all other fields of industrial toxicology. The evolution of the study of lead poisoning during this century is a complete example in the field of occupational toxicology for medical students: it will stimulate them in applying both clinical and preventive knowledge in the field of industrial toxicology. Copyright 2000 Wiley-Liss, Inc.

  3. Study on the dual-synthetic antiferromagnetic property using the Co2FeAl Heulser electrodes

    International Nuclear Information System (INIS)

    Zhang, D L; Xu, X G; Wu, Y; Li, X Q; Miao, J; Jiang, Y

    2011-01-01

    In this paper, we present the experimental results of dual-synthetic antiferromagnets (DSyAFs) with Co 2 FeAl (CFA) Heusler electrodes. It is shown that when the thicknesses of Ru layers are (0.45, 0.65) and (0.45, 1.00) (in nm), the CFA-based DSyAFs have a strong synthetic antiferromagnetic coupling among three CFA layers at room temperature, with a large saturation magnetic field Hs of ∼11000 Oe, a low saturation magnetization Ms of ∼708 emu/cm 3 and a switching field Hsw of ∼2.0 Oe, respectively. It is exciting that the CFA-based DSyAFs have an excellent thermal stability up to 400 0 C. Therefore, the CFA-based DSyAFs are favourable for applications in future spintronic devices.

  4. The relationship of radioimmunoassay to bioassay: In vitro studies with synthetic lysine vasopressin in aqueous solution inactivated by heat

    International Nuclear Information System (INIS)

    Loeve Lemboel, H.

    1978-01-01

    The relationship of radioimmunoassay to pressor assay and antidiuretic assay was investigated in a simple in vitro system of synthetic lysine vasopressin in aqueous solution inactivated by heating at 100 deg C for 9, 18, 27, 36, 54 and 72 h. An apparent dissociation between radioimmunoassay and bioassay was demonstrated, with biological activity being lost more rapidly than immunological activity. The half-times were 32 h for radioimmunoassay, 23 h for antidiuretic assay and 22 h for pressor assay. However, ion-exchange chromatography showed immunological heterogeneity but biological homogeneity of the lysine vasopressin used, and indicated that the presence of impurities in the vasopressin might to some extent explain the discrepancy between assay results. Synthetic arginine vasopressin and arginine vasopressin of pituitary origin showed a similar immunological heterogeneity by ion-exchange chromatography. (author)

  5. Sky View Factors from Synthetic Fisheye Photos for Thermal Comfort Routing—A Case Study in Phoenix, Arizona

    Directory of Open Access Journals (Sweden)

    Ariane Middel

    2017-03-01

    Full Text Available The Sky View Factor (SVF is a dimension-reduced representation of urban form and one of the major variables in radiation models that estimate outdoor thermal comfort. Common ways of retrieving SVFs in urban environments include capturing fisheye photographs or creating a digital 3D city or elevation model of the environment. Such techniques have previously been limited due to a lack of imagery or lack of full scale detailed models of urban areas. We developed a web based tool that automatically generates synthetic hemispherical fisheye views from Google Earth at arbitrary spatial resolution and calculates the corresponding SVFs through equiangular projection. SVF results were validated using Google Maps Street View and compared to results from other SVF calculation tools. We generated 5-meter resolution SVF maps for two neighborhoods in Phoenix, Arizona to illustrate fine-scale variations of intra-urban horizon limitations due to urban form and vegetation. To demonstrate the utility of our synthetic fisheye approach for heat stress applications, we automated a radiation model to generate outdoor thermal comfort maps for Arizona State University’s Tempe campus for a hot summer day using synthetic fisheye photos and on-site meteorological data. Model output was tested against mobile transect measurements of the six-directional radiant flux density. Based on the thermal comfort maps, we implemented a pedestrian routing algorithm that is optimized for distance and thermal comfort preferences. Our synthetic fisheye approach can help planners assess urban design and tree planting strategies to maximize thermal comfort outcomes and can support heat hazard mitigation in urban areas.

  6. Studies on Aculeines: Synthetic Strategy to the Fully Protected Protoaculeine B, the N-Terminal Amino Acid of Aculeine B.

    Science.gov (United States)

    Shiozaki, Hiroki; Miyahara, Masayoshi; Otsuka, Kazunori; Miyako, Kei; Honda, Akito; Takasaki, Yuichi; Takamizawa, Satoshi; Tukada, Hideyuki; Ishikawa, Yuichi; Sakai, Ryuichi; Oikawa, Masato

    2018-05-23

    A synthetic strategy for accessing protoaculeine B (1), the N-terminal amino acid of the highly modified peptide toxin aculeine, was developed via the synthesis of the fully protected natural homologue of 1 with a 12-mer poly(propanediamine). The synthesis of mono(propanediamine) analog 2, as well as core amino acid 3, was demonstrated by this strategy. New amino acid 3 induced convulsions in mice; however, compound 2 showed no such activity.

  7. Psychostimulant Effect of the Synthetic Cannabinoid JWH-018 and AKB48: Behavioral, Neurochemical, and Dopamine Transporter Scan Imaging Studies in Mice

    OpenAIRE

    Ossato, Andrea; Uccelli, Licia; Bilel, Sabrine; Canazza, Isabella; Di Domenico, Giovanni; Pasquali, Micol; Pupillo, Gaia; De Luca, Maria Antonietta; Boschi, Alessandra; Vincenzi, Fabrizio; Rimondo, Claudia; Beggiato, Sarah; Ferraro, Luca; Varani, Katia; Borea, Pier Andrea

    2017-01-01

    JWH-018 and AKB48 are two synthetic cannabinoids (SCBs) belonging to different structural classes and illegally marketed as incense, herbal preparations, or chemical supply for theirs psychoactive cannabis-like effects. Clinical reports from emergency room reported psychomotor agitation as one of the most frequent effects in people assuming SCBs. This study aimed to investigate the psychostimulant properties of JWH-018 and AKB48 in male CD-1 mice and to compare their behavioral and biochemica...

  8. Transport of lead and diesel fuel through a peat soil near Juneau, AK: a pilot study.

    Science.gov (United States)

    Julian Deiss; Carl Byers; Dave Clover; Dave D' Amore; Alan Love; Malcolm A. Menzies; J. Powell; Todd M. Walter

    2004-01-01

    A set of peat column experiments was used to determine the transport potential of lead (Pb) and diesel range organics (DRO) in palustrine slope wetlands near Juneau, AK. This project is important to southeast Alaskan communities because limited land resources are forcing development of regional wetlands. This study was instigated by concerns that proposed modifications...

  9. Paths Leading to Teenage Psychiatric Symptoms and Substance Use: Developmental Epidemiological Studies in Woodlawn.

    Science.gov (United States)

    Kellam, Sheppard G.; And Others

    Early predictors of two major areas of teenage outcome -- substance use and psychiatric symptoms -- were analyzed and specific developmental paths leading to each teenage outcome were identified in this long-term, follow-up study. Substance "use" rather than "abuse" and psychiatric "symptoms" rather than…

  10. Forces affecting employment dynamics in Drenthe; Case study in a leading rural region in the Netherlands

    NARCIS (Netherlands)

    Terluin, I.J.; Post, J.H.; Wisselink, A.J.; Overbeek, M.M.M.

    1999-01-01

    In this report the focus is on employment dynamics in Drenthe since the beginning of the 1980s. This study is part of an EU wide research project on employment development in leading and lagging rural regions of the EU. Total employment in Drenthe increased by 24,500 jobs or with over 20% in the

  11. Leading Integrated Schools: A Study of the Multicultural Perspectives of Northern Irish Principals

    Science.gov (United States)

    McGlynn, Claire

    2008-01-01

    This article is concerned with the sustained peace education initiative of integrated schooling and in particular with leadership responses to cultural diversity. Using a case study group of principals of integrated (mixed Catholic, Protestant and other) schools in Northern Ireland, the author explores how principals perceive and lead their…

  12. Synthetic structural and biochemical studies of coordination compounds of Bismuth (III) with Schiff bases of sulpha drugs

    International Nuclear Information System (INIS)

    Khan, Shahina; Gupta, M.K.; Varshney, S; Varshney, A.K.

    2006-01-01

    The reactions of Bismuth trichloride with Schiff's bases derived from sulpha drugs in 1:1 molar ratio leads to the formation of a new series of coordination compound of Bismuth (III). Their structures have been confirmed on the basis of elemental analysis, ultraviolet, infrared and multinuclear magnetic resonance (1H 13C) spectral studies. The antimicrobial activities of the ligands and their coordination compound have been screened in vitro against the organism Escherichia coli, Stuplhylococus crureus, Prouteus mirabilis, Bacillus thuren giensis, penicilliurn cf.vsogenum, Aspergillns raiger and Fusarium Oxysporum. (author)

  13. A study of copper, lead and cadmium speciation in some estuarine and coastal marine waters

    Energy Technology Data Exchange (ETDEWEB)

    Batley, G E; Gardner, D

    1978-07-01

    The significance of the measured changes in heavy metal distribution for different sampled environments was ascertained. The potential of a heavy metal speciation scheme to reflect differences in marine metal distributions was evaluated in a study of soluble copper, lead, and cadmium speciation in water samples from Port Hacking Estuary and one coastal Pacific station in Australia. In all samples, the percentages of metals associated with colloidal matter were high40-60% of total copper, 45-75% of total lead, and 15-35% of total cadmium. (1 map, 26 references, 4 tables)

  14. Studying the iodine leaching from the compositions based on epoxide resin and lead iodide

    International Nuclear Information System (INIS)

    Kalinin, N.N.; Elizarova, A.N.

    1988-01-01

    When studying iodine leaching, the possibility to use solid compositions, produced by incorporation of dry powdered lead iodide and its aqueous suspension into epoxide resin for long-term immobilization of iodine-129 under conditions of monitored storage, is evaluated. Analysis of the results obtained has shown that leaching rate in the first 4 days has the maximum value and constitutes (4.2 - 2700.0) x 10 -6 cm/day. Then the process of leaching is determined by diffusion mechanism. For samples, prepared by wet lead iodide incorporation the rate of leaching is higher than that of the corresponding samples prepared by dry compound incorporation

  15. Effects of Lead Intoxication on Intervertebral Disc (Experimental Study

    Directory of Open Access Journals (Sweden)

    V.Ye. Maltseva

    2012-02-01

    Full Text Available The article presents the results of experimental study of the effectы of lead intoxication on the intervertebral disc of laboratory rats. It was revealed that in lead intoxication degenerative disorders occur in all parts of the intervertebral disc of rats, affecting both the structure of the annulus fibrosus and the nucleus pulposus. At the same time degenerative changes of the annulus fibrosus can be expressed in disturbance of foliation, due to the appearance of cracks in plates and between them, banding of collagen fibers, reducing the density of fibrochondrocytes. In the nucleus pulposus fragmentation of syncytium structure occurs as well as disturbance of the interconnection between notochordal cells.

  16. Study on the Activation of Scheelite and Wolframite by Lead Nitrate

    Directory of Open Access Journals (Sweden)

    Gang Zhao

    2015-04-01

    Full Text Available The activation of scheelite and wolframite by lead nitrate with benzohydroxamic acid (BHA as collector was investigated by means of micro flotation test, zeta potential measurement, X-ray photoelectron spectroscopy (XPS analyses and density functional theory (DFT calculation. The flotation results confirmed that the addition of lead nitrate can markedly enhance the recovery of scheelite and wolframite. In the zeta potential curves obvious positive shifts were observed with the presence of lead nitrate. Lead was detected on mineral surface in microscopic analysis and the survey XP spectra. Both the electrokinetic study and XPS analyses indicated that lead ion can be adsorbed onto mineral surface. In DFT calculation, the coordination model of BHA with metal hydroxyl ions (Ca(OH+, Mn(OH+, Fe(OH+ and Pb(OH+ was simulated and their binding energy were also calculated. The calculated results revealed that the binding ability of BHA and Pb(OH+ is the strongest, indicating that BHA can preferentially coordinate with Pb ion compared with Ca, Mn and Fe ions.

  17. Biosorption of cadmium (II) and lead (II) from aqueous solutions using mushrooms: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Vimala, R., E-mail: vimararagu@yahoo.co.in [School of Biotechnology, Chemical and Biomedical Engineering, VIT University, Vellore 632014, Tamil Nadu (India); Das, Nilanjana [School of Biotechnology, Chemical and Biomedical Engineering, VIT University, Vellore 632014, Tamil Nadu (India)

    2009-08-30

    Sorption capacity of oyster mushroom (Pleurotus platypus), button mushroom (Agaricus bisporus) and milky mushroom (Calocybe indica) were evaluated on biosorption of heavy metals, viz. cadmium (II) and lead (II) from aqueous solutions. The optimum sorption conditions were studied for each metal separately. The desired pH of the aqueous solution was found to be 6.0 for the removal of cadmium (II) and 5.0 for removal of lead (II) for all the mushrooms. The percent removal of both the metals was found to increase with the increase in biosorbent dosage and contact time. The fitness of the biosorption data for Langmuir and Freundlich adsorption models was investigated. It was found that biosorption of cadmium (II) and lead (II) ions onto the biomass of the three mushrooms were better suitable to Langmuir than Freundlich adsorption model. P. platypus showed the highest metal uptake potential for cadmium (q{sub max} 34.96 mg/g) whereas A. bisporus exhibited maximum potential for lead (q{sub max} 33.78 mg/g). Milky mushroom showed the lowest metal uptake capacity for both the metals. The present data confirms that mushrooms may be used as efficient biosorbent for the removal of cadmium (II) and lead (II) ions from aqueous solution.

  18. Some studies of lead and iron adsorption on the W(100) surface by field emission microscopy

    International Nuclear Information System (INIS)

    Jones, J.P.; Roberts, E.W.

    1978-01-01

    The behaviour of lead and iron adsorbed on the W(100) surface has been studied by probe hole field emission microscopy, field desorption, and by measurement of the total energy distribution (TED) of field-emitted electrons. Lead adsorbed at 300 K which reduces the work function of W(100) can be completely removed at 78 K by field desorption below 3.2 V A -1 and the resulting surface has both the work function and TED, which are characteristic of the clean plane. Condensation at 800 K followed by field desorption, results in a plane surface of work function 4.17 eV and an altered TED. This effect is attributed to the microfacetting, which is observed by LEED. The Swanson peak in the W(100) TED which is removed by submonolayer amounts of lead re-emerges at monolayer coverage when lead adopts the (1 X 1) structure. Such behaviour is consistent with the model proposed by Kar and Soven. A spectral peak observed when lead is adsorbed on the reconstructed W(100) surface is thought to derive for the atomic 1 D state. Adsorption of iron on a W(100) surface reduces phi considerably due to dipole formation and efficiently quenches the Swanson peak. (Auth.)

  19. Multicollinearity may lead to artificial interaction: an example from a cross sectional study of biomarkers.

    Science.gov (United States)

    Sithisarankul, P; Weaver, V M; Diener-West, M; Strickland, P T

    1997-06-01

    Collinearity is the situation which arises in multiple regression when some or all of the explanatory variables are so highly correlated with one another that it becomes very difficult, if not impossible, to disentangle their influences and obtain a reasonably precise estimate of their effects. Suppressor variable is one of the extreme situations of collinearity that one variable can substantially increase the multiple correlation when combined with a variable that is only modestly correlated with the response variable. In this study, we describe the process by which we disentangled and discovered multicollinearity and its consequences, namely artificial interaction, using the data from cross-sectional quantification of several biomarkers. We showed how the collinearity between one biomarker (blood lead level) and another (urinary trans, trans-muconic acid) and their interaction (blood lead level* urinary trans, trans-muconic acid) can lead to the observed artificial interaction on the third biomarker (urinary 5-aminolevulinic acid).

  20. Micro-analytical study of interactions between oil and lead compounds in paintings

    International Nuclear Information System (INIS)

    Cotte, M.; Checroun, E.; Susini, J.; Walter, P.

    2007-01-01

    Oil paintings are complex hybrid materials, made of organic binders associated with inorganic minerals, susceptible to evolving over centuries. In particular, interactions of oil with lead compounds may give rise to the formation of lead soap aggregates, so-called protrusions. This phenomenon is studied here via X-ray and FTIR micro-analysis of an ancient painting dated from 1610. In complement, the synthesis of modern preparations, reconstructed from ancient recipes was assessed. Molecular and atomic images are obtained by combining synchrotron-based FTIR and X-ray fluorescence microscopies. Protrusions are identified in both ancient and modern samples, more particularly, in the ground layer of the paintings, below the colored layer. These observations imply that lead oxide, introduced as a siccative and not as a pigment, may be the element mainly responsible for the protrusions formation, and that this degradation may appear very rapidly on paintings. (orig.)

  1. An Influence Study of Hydrogen Evolution Characteristics on the Negative Strap Corrosion of Lead Acid Battery

    Directory of Open Access Journals (Sweden)

    Zhong Guobin

    2015-01-01

    Full Text Available Negative strap corrosion is an important reason for the failure of valve regulated lead acid battery. This paper selected the Pb-Sb alloy material and Pb-Sn alloy material, made an investigation on the negative corrosion resistance and hydrogen evolution of these two alloy materials by scanning electron microscope analysis, metallographic analysis, chemical study and linear sweep voltammetry, and discussed the influence of lead alloy hydrogen evolution on the negative strap corrosion. The results showed that the hydrogen evolution reaction rates of the alloys had an impact on the corrosion areas with the maximum thickness of the alloys and the depth of corrosion layers. Greater hydrogen evolution reaction rate can lead to shorter distance between the corrosion area with the maximum thickness and the liquid level; whereas the greater corrosion layer thickness can bring aggravated risk of negative strap corrosion failure.

  2. Sintering study in vertical fixed bed reactor for synthetic aggregate production; Estudo da sinterizacao em reator vertical de leito fixo para producao de agregado sintetico

    Energy Technology Data Exchange (ETDEWEB)

    Quaresma, D.S.; Neves, A.S.S.; Melo, A.O.; Pereira, L.F.S.; Bezerra, P.T.S.; Macedo, E.N.; Souza, J.A.S., E-mail: danysq@gmail.com [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Faculdade de Engenharia Quimica

    2017-04-15

    The synthetic aggregates are being employed in civil construction for the reduction of mineral extraction activities. Within this context, the recycling of industrial waste is the basis of the majority of processes to reduce the exploitation of mineral resources. In this work the sintering in a vertical fixed bed reactor for synthetic aggregate production using 20% pellets and 80% charcoal was studied. The pellets were prepared from a mixture containing clay, charcoal and fly ash. Two experiments varying the speed of air sucking were carried out. The material produced was analyzed by X-ray diffraction, scanning electron microscopy, measures of their ceramic properties, and particle size analysis. The results showed that the solid-state reactions, during the sintering process, were efficient and the produced material was classified as coarse lightweight aggregate. The process is interesting for the sintering of aggregates, and can be controlled by composition, particle size, temperature gradient and gaseous flow. (author)

  3. Preliminary study of flotation behavior of Besham Lead-Zinc ore

    International Nuclear Information System (INIS)

    Khan, M.M.; Din, F.; Rafiq, M.

    2001-01-01

    This preliminary study examines the flotation behavior of the mineral galena from Besham Lead-Zinc ore samples with reference to the particle size, collector types such as Ethyl and Propyl xanthates and depressants. The comminution of the as mined ore was carried out in the laboratory jaw crusher and disc mill as well as in a laboratory ball mill. The material having size range between-90 microns and +63 microns was selected for flotation studies. (author)

  4. Learning and Leading with Technology: A Case Study of Centennial Campus Magnet Middle School

    Science.gov (United States)

    Morris-Bryant, Edye Darlene

    2012-01-01

    The purpose of this single case study is to describe and document the implementation of a 1:1 laptop program for a middle school with a unique school-university partnership. The goal of this study is two-fold; one being to describe the implementation of a 1:1 laptop program and to document the lessons learned in leading a 1:1 laptop program. This…

  5. Evolvable synthetic neural system

    Science.gov (United States)

    Curtis, Steven A. (Inventor)

    2009-01-01

    An evolvable synthetic neural system includes an evolvable neural interface operably coupled to at least one neural basis function. Each neural basis function includes an evolvable neural interface operably coupled to a heuristic neural system to perform high-level functions and an autonomic neural system to perform low-level functions. In some embodiments, the evolvable synthetic neural system is operably coupled to one or more evolvable synthetic neural systems in a hierarchy.

  6. [From synthetic biology to synthetic humankind].

    Science.gov (United States)

    Nouvel, Pascal

    2015-01-01

    In this paper, we propose an historical survey of the expression "synthetic biology" in order to identify its main philosophical components. The result of the analysis is then used to investigate the meaning of the notion of "synthetic man". It is shown that both notions share a common philosophical background that can be summed up by the short but meaningful assertion: "biology is technology". The analysis allows us to distinguish two notions that are often confused in transhumanist literature: the notion of synthetic man and the notion of renewed man. The consequences of this crucial distinction are discussed. Copyright © 2015 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  7. Occupational lead exposure among automotive garage workers – a case study for Jimma town, Ethiopia

    Directory of Open Access Journals (Sweden)

    Adela Yalemsew

    2012-07-01

    Full Text Available Abstract Background In Ethiopia, although there are numerous small-scale and medium industries which use lead-based raw materials that may pose health risks to workers, there are no workplace regulations for lead exposure. Moreover, there are no studies carried out on the blood lead levels (BLLs of workers or on the contribution of common workplace practices to lead poisoning. Method A cross-sectional study on the BLLs of 45 automotive garage workers and 40 non-garage workers was carried out in the town of Jimma, Ethiopia. In addition to BLL analysis, data on some risk factors such as smoking, and chewing ‘khat’ (the leaves of Catha adulis were gathered through structured questionnaires and interviews and data analysis was performed using SPSS (version 16. The t-test was used to compare mean BLLs of study groups. The analysis of variance (ANOVA, Kruskal-Wallis, Pearson chi-square and odds ratio tests were used to investigate the associations between specific job type, smoking and/or ‘khat’ chewing, service years and occurrence of non-specific symptoms with BLLs. Results The mean BLL of the automotive-garage workers was found to be significantly greater than that of the controls. The BLLs of all the lead-exposed individuals were found to be over 10 μg/dL, and 53% of them had BLLs ranging 12 – 20 μg/dL, with the remaining 47% having over 20 μg/dL. The BLL of the workers increased with the duration of working in an automotive garage. Individuals involved in manual car painting comprise a larger percentage (58% of those with the highest BLLs (≥ 20 μg/dL. Lead accumulation in individuals who chew ‘khat’ in the work place was found to be faster than in those who are not used to chewing ‘khat’. ‘Khat’ is an evergreen shrub native to tropical East Africa, with dark green opposite leaves which are chewed when fresh for their stimulating effects. Conclusion The findings of the study have clearly demonstrated that the

  8. Potential of Opuntia ficus-indica for air pollution biomonitoring: a lead isotopic study.

    Science.gov (United States)

    El Hayek, Eliane; El Samrani, Antoine; Lartiges, Bruno; Kazpard, Veronique; Benoit, Mathieu; Munoz, Marguerite

    2015-11-01

    Opuntia ficus-indica (Ofi) is a long-domesticated cactus that is widespread throughout arid and semiarid regions. Ofi is grown for both its fruits and edible cladodes, which are flattened photosynthetic stems. Young cladodes develop from mother cladodes, thus forming series of cladodes of different ages. Therefore, successive cladodes may hold some potential for biomonitoring over several years the local atmospheric pollution. In this study, cladodes, roots, dust deposited onto the cladodes, and soil samples were collected in the vicinity of three heavily polluted sites, i.e., a fertilizer industry, the road side of a highway, and mine tailings. The lead content was analyzed using atomic absorption spectroscopy (AAS) and inductively coupled plasma-mass spectrometry (ICP-MS). Scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX) was used to characterize the cladode surfaces and the nature of dust deposit, and the lead isotopes were analyzed to identify the origin of Pb. The results show that (i) Ofi readily bioaccumulates Pb, (ii) the lead isotopic composition of cladodes evidences a foliar pathway of lead into Ofi and identifies the relative contributions of local Pb sources, and (iii) an evolution of air quality is recorded with successive cladodes, which makes Ofi a potential biomonitor to be used in environmental and health studies.

  9. Levels of lead in foods from the first French total diet study on infants and toddlers.

    Science.gov (United States)

    Guérin, Thierry; Le Calvez, Emilie; Zinck, Julie; Bemrah, Nawel; Sirot, Véronique; Leblanc, Jean-Charles; Chekri, Rachida; Hulin, Marion; Noël, Laurent

    2017-12-15

    Infants and toddlers are highly vulnerable to exposure to lead due to its higher absorption in small children than in adults. This study describes the optimisation and validation of a very sensitive method for the determination of low levels of lead in foods mostly consumed by infants and toddlers. This method, based on inductively coupled plasma-mass spectrometry with a programmable temperature cyclonic spray chamber, attained a limit of quantification (LOQ) of 0.6 or 0.9µgPbkg -1 for a liquid or a solid sample, that was improved by a factor 5.6-8.3 compared to the previous method (LOQ: 5µgkg -1 ). The analytical method was then applied to 291 food samples from the first French total diet study on infants and toddlers. Lead was detected in most samples at relatively low concentrations (range 0.0-16µgkg -1 ). The highest lead concentrations were mainly found in processed food products (e.g. products containing chocolate). Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. An analytical study of prehistoric lead and silver objects from the Aegean

    International Nuclear Information System (INIS)

    Pernicka, E.; Wagner, G.A.; Assimenos, K.; Doumas, C.; Begemann, F.; Todt, W.

    1983-01-01

    In the course of an archaeometallurgical study on the metal sources of archaic silver coinage it was discovered that lead-silver mines on the Cycladic island of Siphnos, which were known to Herodotus (III, 57) and exploited in archaic times, were already worked in the Early Bronze Age (EBA). In addition, new excavations in Thorikos have shown that the well-known lead-silver deposit of Laurion on Attika was also exploited as early as the EBA. In order to assess the role which these two mining districts and other possible ore sources played in the Bronze Age for the supply of lead and silver, we analyzed prehistoric lead and silver objects from the Aegean region. The methods employed were the same as have been used to characterize the ore deposits. In addition we wanted to study to what extent cupellation was practised in these early periods. Bulk composition and trace element concentrations were determined by instrumental and radiochemical neutron activation and atomic absorption spectrometry. Isotope abundance analyses were performed on a VARIAN MAT 261 mass spectrometer. Experimental details are given. Results are presented and discussed. (U.K.)

  11. Study of the contamination of forages and legumes by lead and heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Delcarte, E; Impens, R; Kirchmann, R; Nangniot, P; Fagniart, E

    1975-01-01

    A description of the methods used by the authors for their study of contamination of the environment and of the food chain by heavy metals is presented with particular reference to lead, cadmium and zinc. The first phase consists of taking samples, in industrial and urban areas and in the vicinity of highways, of soil and various common plants, including Plantago major L. (greater plantain), Ligustrum sp. (privet), Trifolium repens L. (white clover) and Tussilago farfara L. (coltsfoot). Concentrations of metal substances in these samples are measured by means of oscillopolarography at a set voltage. Risk areas are thus demarcated where fodder, vegetable and fruit samples are taken regularly throughout the vegetation period. A watch is kept on the progress and extent of Zn, Cd, Pb, Ni, Co and Cu fall-out in vegetable gardens and orchards in the vicinity of smelters in the Meuse valley. The results are compared with those obtained in the suburbs of Brussels near highway intersections and in a control area, away from any source of pollution. These results reveal that there is a serious risk of chronic poisoning in human beings and animals which feed on contaminated plants. Parallel laboratory tests are being carried out on the absorption, retention and toxicity of these metal substances in plants. The results obtained using stable lead and /sup 210/lead in Zea mays L. (maize) are discussed. Finally, dairy cattle are being experimentally fed on fodder which has been artificially enriched with stable lead and /sup 210/lead. The aim is to calculate the rate of alimentary lead transfer to the milk, urine and feces.

  12. Predictors of environmental lead exposure among pregnant women – a prospective cohort study in Poland

    Directory of Open Access Journals (Sweden)

    Kinga Polańska

    2014-03-01

    Full Text Available Blood lead levels (BLL in women of child-bearing age have been decreasing in recent decades, but still remains a concern for long-term effects of child psychomotor development. The aim of the study was to characterize lead exposure among Polish pregnant women and assess the relationship between BLL and selected socio-demographic, economic and lifestyle factors. The study population consisted of 594 pregnant women who had been the subjects of the prospective Polish Mother and Child Cohort Study (REPRO_PL. The women were interviewed three times during pregnancy (once in each trimester. Lead concentration in the blood collected during the second trimester of pregnancy was analyzed using graphite furnace atomic absorption spectrometry (GF-AAS, or inductively coupled plasma mass spectrometry (ICP-MS. Active and passive smoking was analyzed by the cotinine level in saliva using liquid chromatography with tandem mass spectrometry (LC-MS/MS. The lead level in the blood ranged from 0.3 – 5.7 μg/dL, with a geometric mean (GM of 1.1 μg/dL (GSD }0.2 μg/dL. Statistically significant associations were found between BLL and factors such as maternal age (β=0.01; p=0.02, education (β=0.08; p=0.04 and prepregnancy BMI (β=0.1; p=0.001. Additionally, BLL increased with increasing cotinine level in saliva (β=0.02; p=0.06 and decreased with the increasing distance from the copper smelter (β=-0.1; p=0.009. Public health interventions, especially in regions with a higher level of exposure to lead, among women with lower SES and among smokers, are still reasonable.

  13. Synthetic biology, metaphors and responsibility.

    Science.gov (United States)

    McLeod, Carmen; Nerlich, Brigitte

    2017-08-29

    Metaphors are not just decorative rhetorical devices that make speech pretty. They are fundamental tools for thinking about the world and acting on the world. The language we use to make a better world matters; words matter; metaphors matter. Words have consequences - ethical, social and legal ones, as well as political and economic ones. They need to be used 'responsibly'. They also need to be studied carefully - this is what we want to do through this editorial and the related thematic collection. In the context of synthetic biology, natural and social scientists have become increasingly interested in metaphors, a wave of interest that we want to exploit and amplify. We want to build on emerging articles and books on synthetic biology, metaphors of life and the ethical and moral implications of such metaphors. This editorial provides a brief introduction to synthetic biology and responsible innovation, as well as a comprehensive review of literature on the social, cultural and ethical impacts of metaphor use in genomics and synthetic biology. Our aim is to stimulate an interdisciplinary and international discussion on the impact that metaphors can have on science, policy and publics in the context of synthetic biology.

  14. Temporal Decorrelation Effect in Carbon Stocks Estimation Using Polarimetric Interferometry Synthetic Aperture Radar (PolInSAR (Case Study: Southeast Sulawesi Tropical Forest

    Directory of Open Access Journals (Sweden)

    Laode M Golok Jaya

    2017-07-01

    Full Text Available This paper was aimed to analyse the effect of temporal decorrelation in carbon stocks estimation. Estimation of carbon stocks plays important roles particularly to understand the global carbon cycle in the atmosphere regarding with climate change mitigation effort. PolInSAR technique combines the advantages of Polarimetric Synthetic Aperture Radar (PolSAR and Interferometry Synthetic Aperture Radar (InSAR technique, which is evidenced to have significant contribution in radar mapping technology in the last few years. In carbon stocks estimation, PolInSAR provides information about vertical vegetation structure to estimate carbon stocks in the forest layers. Two coherence Synthetic Aperture Radar (SAR images of ALOS PALSAR full-polarimetric with 46 days temporal baseline were used in this research. The study was carried out in Southeast Sulawesi tropical forest. The research method was by comparing three interferometric phase coherence images affected by temporal decorrelation and their impacts on Random Volume over Ground (RvoG model. This research showed that 46 days temporal baseline has a significant impact to estimate tree heights of the forest cover where the accuracy decrease from R2=0.7525 (standard deviation of tree heights is 2.75 meters to R2=0.4435 (standard deviation 4.68 meters and R2=0.3772 (standard deviation 3.15 meters respectively. However, coherence optimisation can provide the best coherence image to produce a good accuracy of carbon stocks.

  15. Genomics-Based Discovery of Plant Genes for Synthetic Biology of Terpenoid Fragrances: A Case Study in Sandalwood oil Biosynthesis.

    Science.gov (United States)

    Celedon, J M; Bohlmann, J

    2016-01-01

    Terpenoid fragrances are powerful mediators of ecological interactions in nature and have a long history of traditional and modern industrial applications. Plants produce a great diversity of fragrant terpenoid metabolites, which make them a superb source of biosynthetic genes and enzymes. Advances in fragrance gene discovery have enabled new approaches in synthetic biology of high-value speciality molecules toward applications in the fragrance and flavor, food and beverage, cosmetics, and other industries. Rapid developments in transcriptome and genome sequencing of nonmodel plant species have accelerated the discovery of fragrance biosynthetic pathways. In parallel, advances in metabolic engineering of microbial and plant systems have established platforms for synthetic biology applications of some of the thousands of plant genes that underlie fragrance diversity. While many fragrance molecules (eg, simple monoterpenes) are abundant in readily renewable plant materials, some highly valuable fragrant terpenoids (eg, santalols, ambroxides) are rare in nature and interesting targets for synthetic biology. As a representative example for genomics/transcriptomics enabled gene and enzyme discovery, we describe a strategy used successfully for elucidation of a complete fragrance biosynthetic pathway in sandalwood (Santalum album) and its reconstruction in yeast (Saccharomyces cerevisiae). We address questions related to the discovery of specific genes within large gene families and recovery of rare gene transcripts that are selectively expressed in recalcitrant tissues. To substantiate the validity of the approaches, we describe the combination of methods used in the gene and enzyme discovery of a cytochrome P450 in the fragrant heartwood of tropical sandalwood, responsible for the fragrance defining, final step in the biosynthesis of (Z)-santalols. © 2016 Elsevier Inc. All rights reserved.

  16. Study on homogenization of synthetic GNSS-retrieved IWV time series and its impact on trend estimates with autoregressive noise

    Science.gov (United States)

    Klos, Anna; Pottiaux, Eric; Van Malderen, Roeland; Bock, Olivier; Bogusz, Janusz

    2017-04-01

    A synthetic benchmark dataset of Integrated Water Vapour (IWV) was created within the activity of "Data homogenisation" of sub-working group WG3 of COST ES1206 Action. The benchmark dataset was created basing on the analysis of IWV differences retrieved by Global Positioning System (GPS) International GNSS Service (IGS) stations using European Centre for Medium-Range Weather Forecats (ECMWF) reanalysis data (ERA-Interim). Having analysed a set of 120 series of IWV differences (ERAI-GPS) derived for IGS stations, we delivered parameters of a number of gaps and breaks for every certain station. Moreover, we estimated values of trends, significant seasonalities and character of residuals when deterministic model was removed. We tested five different noise models and found that a combination of white and autoregressive processes of first order describes the stochastic part with a good accuracy. Basing on this analysis, we performed Monte Carlo simulations of 25 years long data with two different types of noise: white as well as combination of white and autoregressive processes. We also added few strictly defined offsets, creating three variants of synthetic dataset: easy, less-complicated and fully-complicated. The 'Easy' dataset included seasonal signals (annual, semi-annual, 3 and 4 months if present for a particular station), offsets and white noise. The 'Less-complicated' dataset included above-mentioned, as well as the combination of white and first order autoregressive processes (AR(1)+WH). The 'Fully-complicated' dataset included, beyond above, a trend and gaps. In this research, we show the impact of manual homogenisation on the estimates of trend and its error. We also cross-compare the results for three above-mentioned datasets, as the synthetized noise type might have a significant influence on manual homogenisation. Therefore, it might mostly affect the values of trend and their uncertainties when inappropriately handled. In a future, the synthetic dataset

  17. Recent studies on radiation damage formation in synthetic NaCl and natural rock salt for radioactive waste disposal applications

    International Nuclear Information System (INIS)

    Swyler, K.J.; Klaffky, R.W.; Levy, P.W.

    1980-01-01

    Radiation damage formation in natural rock salt is described as a function of irradiation temperature and plastic deformation. F-center formation decreases with increasing temperature while significant colloidal sodium formation occurs over a restricted temperature range around 150 0 C. Plastic deformation increases colloid formation; it is estimated that colloid concentrations may be increased by a factor of 3 if the rock salt near radioactive waste disposal canisters is heavily deformed. Optical bandshape analysis indicates systematic differences between the colloids formed in synthetic and natural rock salts

  18. Antimalarial activity of synthetic 1,2,4-trioxanes and cyclic peroxy ketals, a quantum similarity study

    Science.gov (United States)

    Gironés, X.; Gallegos, A.; Carbó-Dorca, R.

    2001-12-01

    In this work, the antimalarial activity of two series of 20 and 7 synthetic 1,2,4-trioxanes and a set of 20 cyclic peroxy ketals are tested for correlation search by means of Molecular Quantum Similarity Measures (MQSM). QSAR models, dealing with different biological responses (IC90, IC50 and ED90) of the parasite Plasmodium Falciparum, are constructed using MQSM as molecular descriptors and are satisfactorily correlated. The statistical results of the 20 1,2,4-trioxanes are deeply analyzed to elucidate the relevant structural features in the biological activity, revealing the importance of phenyl substitutions.

  19. The improved biological response of shark tooth bioapatites in a comparative in vitro study with synthetic and bovine bone grafts.

    Science.gov (United States)

    López-Álvarez, M; Pérez-Davila, S; Rodríguez-Valencia, C; González, P; Serra, J

    2016-06-07

    Autologous bone is considered to be the gold standard for bone tissue regeneration, providing more highly efficient functional responses compared to synthetic materials, and avoiding the rejection risks of allogenic grafts. However, it presents limitations for certain types of surgery due to its high resorption levels and donor site morbidity. Different biphasic synthetic composites, based onnon-apatitic calcium phosphates enriched with apatitic phases-such as hydroxyapatite, and bioderived bone grafts of bovine and porcine origin-are proposed as lower resorption materials due to their higher crystalline structure. The present work proposes two new sources of bioapatites for bone filler applications obtained from the dentine and enameloid of shark teeth, respectively. These bioapatites each present a characteristic apatite-based composition and additional enrichments of specific trace elements, such as magnesium and fluorine, with proven roles in bone metabolism. Their processing and physicochemical characterization (SEM, FT-Raman and XRD) is presented, together with an in vitro evaluation of osteogenic activity compared to a commercial bovine mineralized matrix and synthetic HA/β TCP grafts. The results proved the globular morphology (0.5-1.5 μm) and porosity (~50 μm and ~0.5-1 μm) of shark dentine bioapatites with biphasic composition: apatitic (hydroxyapatite and apatite-(CaF)), non-apatitic (whitlockite), and an apatitic phase (fluorapatite), organized in oriented crystals in enameloid bioapatites. An evaluation of the pre-osteoblast MC3T3-E1 morphology revealed the colonization of pores in dentine bioapatites and an aligned cell growth in the oriented enameloid crystals. A higher proliferation (p  <  0.01) was detected at up to 21 d in both the shark bioapatites and synthetic biphasic graft with respect to the bovine mineralized matrix. Finally, the great potential of porous biphasic dentine bioapatites enriched with Mg and the aligned

  20. Synthetic neurosteroids on brain protection

    Directory of Open Access Journals (Sweden)

    Mariana Rey

    2015-01-01

    Full Text Available Neurosteroids, like allopregnanolone and pregnanolone, are endogenous regulators of neuronal excitability. Inside the brain, they are highly selective and potent modulators of GABA A receptor activity. Their anticonvulsant, anesthetics and anxiolytic properties are useful for the treatments of several neurological and psychiatric disorders via reducing the risks of side effects obtained with the commercial drugs. The principal disadvantages of endogenous neurosteroids administration are their rapid metabolism and their low oral bioavailability. Synthetic steroids analogues with major stability or endogenous neurosteroids stimulation synthesis might constitute promising novel strategies for the treatment of several disorders. Numerous studies indicate that the 3α-hydroxyl configuration is the key for binding and activity, but modifications in the steroid nucleus may emphasize different pharmacophores. So far, several synthetic steroids have been developed with successful neurosteroid-like effects. In this work, we summarize the properties of various synthetic steroids probed in trials throughout the analysis of several neurosteroids-like actions.

  1. A study of leading indicators for occupational health and safety management systems in healthcare.

    Science.gov (United States)

    Almost, Joan M; VanDenKerkhof, Elizabeth G; Strahlendorf, Peter; Caicco Tett, Louise; Noonan, Joanna; Hayes, Thomas; Van Hulle, Henrietta; Adam, Ryan; Holden, Jeremy; Kent-Hillis, Tracy; McDonald, Mike; Paré, Geneviève C; Lachhar, Karanjit; Silva E Silva, Vanessa

    2018-04-23

    In Ontario, Canada, approximately $2.5 billion is spent yearly on occupational injuries in the healthcare sector. The healthcare sector has been ranked second highest for lost-time injury rates among 16 Ontario sectors since 2009 with female healthcare workers ranked the highest among all occupations for lost-time claims. There is a great deal of focus in Ontario's occupational health and safety system on compliance and fines, however despite this increased focus, the injury statistics are not significantly improving. One of the keys to changing this trend is the development of a culture of healthy and safe workplaces including the effective utilization of leading indicators within Occupational Health and Safety Management Systems (OHSMSs). In contrast to lagging indicators, which focus on outcomes retrospectively, a leading indicator is associated with proactive activities and consists of selected OHSMSs program elements. Using leading indicators to measure health and safety has been common practice in high-risk industries; however, this shift has not occurred in healthcare. The aim of this project is to conduct a longitudinal study implementing six elements of the Ontario Safety Association for Community and Healthcare (OSACH) system identified as leading indicators and evaluating the effectiveness of this intervention on improving selected health and safety workplace indicators. A quasi-experimental longitudinal research design will be used within two Ontario acute care hospitals. The first phase of the study will focus on assessing current OHSMSs using the leading indicators, determining potential facilitators and barriers to changing current OHSMSs, and identifying the leading indicators that could be added or changed to the existing OHSMS in place. Phase I will conclude with the development of an intervention designed to support optimizing current OHSMSs in participating hospitals based on identified gaps. Phase II will pilot test and evaluate the tailored

  2. Mobile Phone Use, Blood Lead Levels, and Attention Deficit Hyperactivity Symptoms in Children: A Longitudinal Study

    Science.gov (United States)

    Byun, Yoon-Hwan; Ha, Mina; Kwon, Ho-Jang; Hong, Yun-Chul; Leem, Jong-Han; Sakong, Joon; Kim, Su Young; Lee, Chul Gab; Kang, Dongmug; Choi, Hyung-Do; Kim, Nam

    2013-01-01

    Background Concerns have developed for the possible negative health effects of radiofrequency electromagnetic field (RF-EMF) exposure to children’s brains. The purpose of this longitudinal study was to investigate the association between mobile phone use and symptoms of Attention Deficit Hyperactivity Disorder (ADHD) considering the modifying effect of lead exposure. Methods A total of 2,422 children at 27 elementary schools in 10 Korean cities were examined and followed up 2 years later. Parents or guardians were administered a questionnaire including the Korean version of the ADHD rating scale and questions about mobile phone use, as well as socio-demographic factors. The ADHD symptom risk for mobile phone use was estimated at two time points using logistic regression and combined over 2 years using the generalized estimating equation model with repeatedly measured variables of mobile phone use, blood lead, and ADHD symptoms, adjusted for covariates. Results The ADHD symptom risk associated with mobile phone use for voice calls but the association was limited to children exposed to relatively high lead. Conclusions The results suggest that simultaneous exposure to lead and RF from mobile phone use was associated with increased ADHD symptom risk, although possible reverse causality could not be ruled out. PMID:23555766

  3. Mobile phone use, blood lead levels, and attention deficit hyperactivity symptoms in children: a longitudinal study.

    Directory of Open Access Journals (Sweden)

    Yoon-Hwan Byun

    Full Text Available BACKGROUND: Concerns have developed for the possible negative health effects of radiofrequency electromagnetic field (RF-EMF exposure to children's brains. The purpose of this longitudinal study was to investigate the association between mobile phone use and symptoms of Attention Deficit Hyperactivity Disorder (ADHD considering the modifying effect of lead exposure. METHODS: A total of 2,422 children at 27 elementary schools in 10 Korean cities were examined and followed up 2 years later. Parents or guardians were administered a questionnaire including the Korean version of the ADHD rating scale and questions about mobile phone use, as well as socio-demographic factors. The ADHD symptom risk for mobile phone use was estimated at two time points using logistic regression and combined over 2 years using the generalized estimating equation model with repeatedly measured variables of mobile phone use, blood lead, and ADHD symptoms, adjusted for covariates. RESULTS: The ADHD symptom risk associated with mobile phone use for voice calls but the association was limited to children exposed to relatively high lead. CONCLUSIONS: The results suggest that simultaneous exposure to lead and RF from mobile phone use was associated with increased ADHD symptom risk, although possible reverse causality could not be ruled out.

  4. [Blood lead levels during pregnancy in th the newborn period. Study of the population of Bari].

    Science.gov (United States)

    Carbone, R; Laforgia, N; Crollo, E; Mautone, A; Iolascon, A

    1998-01-01

    Blood lead levels during pregnancy and in neonates immediately after birth have been evaluated, showing higher values in mothers compared to neonates (5.81 +/- 3.05 vs 4.87 +/- 3.60 micrograms/100 ml) and a positive correlation between maternal and neonatal levels (r = 0.82). On the basis of the results derived from the population examined, it has been observed that 6% of newborns have blood lead levels higher than 10 micrograms/100 ml a value recently identified by the Centers for Disease Control (CDC, Atlanta, USA) as a limit for toxicity in children. Moreover, neonatal Pb levels were higher than those found in infants from 6 to 12 months (4.87 +/- 3.60 vs 2.24 +/- 0.54 micrograms/100 ml). During the first week of life there is a steady decrease of blood lead levels, together with increasing renal lead excretion. This study was carried out at the "Dipartimento di Biomedicina dell'Età Evolutiva" University of Bari, southern Italy.

  5. Kinetic study on recovery of metal values in anode slime from used lead batteries

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, S.; Nagasaka, T. [Tohoku Univ., Sendai (Japan). Dept. of Environmental Studies; Ono, J.; Hino, M. [Tohoku Univ., Sendai (Japan). Dept. of Metallurgy

    2004-07-01

    Oxidation experiments were conducted with pure antimony and antimony-lead bismuth alloys to examine the oxidation kinetics and mechanisms used to treat the anode slime produced during lead electrorefining and recovery of antimony from used lead batteries. In order to recycle and recover valuable metals from the used lead batteries, the oxidation experiments were conducted with pure liquid antimony at temperatures between 973 and 1373 K. The study showed that the gas phase mass transfer step is the basic mechanisms that controls the oxidation rate for pure antimony. It was noted that the oxidation rate of the alloy was identical to that of the pure antimony, suggesting that an oxidation reaction of the anode slime proceeds at the same rate as pure antimony. This is one of the advantages of treating anode slime through oxidation. Mass transfer in the gas phase was the rate-determining step in the alloy oxidation reaction. It was concluded that a higher oxygen partial pressure and sufficient gas flow rate at temperature of 1073 K is needed to conserve energy and recovery antimony oxide. 13 refs., 2 tabs., 12 figs.

  6. Coupled study of radionuclides and stable lead isotopes in Western Mediterranean

    International Nuclear Information System (INIS)

    Miralles, J.

    2004-05-01

    The aim of this work is to identified an environmental deposit able to have stored the atmospheric signal over large time-scale leaning our investigations on lead stable isotopes ( 206 Pb, 207 Pb, 208 Pb) and radionuclide ( 210 Pb, 137 Cs, 239 Pu, 240 Pu) analysis. Owing to prior studies on anthropogenic lead sources, emission intensity and sedimentary accumulation, we choose to investigate the marine sediments of the Western Mediterranean. In the Gulf of Lions, the sedimentary accumulation is 110 ± 7 μg.cm -2 high in good agreement with the atmospheric inventory estimate we made from salt marshes of Camargue (99 μg.cm -2 ). The reconstructed lead accumulation through a modelling step coupling 210 Pb and stable isotopes corroborates the regional anthropogenic emissions (Ferrand, 1996). Briefly, in this context of the marine sediments are a relevant proxy to study past lead atmospheric concentration over the last hundred years. In the Alboran Sea, the study area is less constrained and more complex in terms of climatic, meteorological and hydrological conditions. The sedimentary inventory is of 153 ± 47 μg.cm -2 , 1,5 higher than in the margin sediments of the Gulf of Lions. The analysis of aerosols, sediments and settling particles evidences a continuity between the atmospheric signal and the sedimentary record. In spite of this encouraging results, the knowledge of the Alboran system is still too restricted in order to unambiguously conclude on accuracy of deep marine sediments of this area to study past atmospheric fallouts. (author)

  7. Pharmacological and spectral studies of synthetic biomimetic copper complexes derived from 3-hydroxyflavone derivatives as anti-inflammatory agents

    Directory of Open Access Journals (Sweden)

    K. Nagashri

    2016-09-01

    Full Text Available Novel biomimetic ligands were synthesized by the condensation of 3-hydroxyflavone, 2-aminophenol(L1/2-aminobenzoic acid (L2 and-aminothiazole (L3. Their Cu(II complexes have also been synthesized and characterized on the basis of 1H NMR, IR, UV–Vis spectra, elemental analyses, molar conductivity, ESR, electrochemical behaviour and thermal analyses. The antimicrobial activities (MIC values of the ligands, copper complexes and standard drugs have been evaluated using the serial dilution technique against the bacterial species Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris and Pseudomonas aeruginosa and fungal species Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans. The anti-inflammatory and SOD activities of the investigated compounds are also promising and allow the selection of a lead compound for further biological studies.

  8. Structure-Activity Relationship Study of Sesquiterpene Lactones and Their Semi-Synthetic Amino Derivatives as Potential Antitrypanosomal Products

    Directory of Open Access Journals (Sweden)

    Stefanie Zimmermann

    2014-03-01

    Full Text Available Sesquiterpene lactones (STLs are natural products that have potent antitrypanosomal activity in vitro and, in the case of cynaropicrin, also reduce parasitemia in the murine model of trypanosomiasis. To explore their structure-antitrypanosomal activity relationships, a set of 34 natural and semi-synthetic STLs and amino-STLs was tested in vitro against T. b. rhodesiense (which causes East African sleeping sickness and mammalian cancer cells (rat bone myoblast L6 cells. It was found that the α-methylene-γ-lactone moiety is necessary for both antitrypanosomal effects and cytotoxicity. Antitrypanosomal selectivity is facilitated by 2-(hydroxymethylacrylate or 3,4-dihydroxy-2-methylenebutylate side chains, and by the presence of cyclopentenone rings. Semi-synthetic STL amines with morpholino and dimethylamino groups showed improved in vitro activity over the native STLs. The dimethylamino derivative of cynaropicrin was prepared and tested orally in the T. b. rhodesiense acute mouse model, where it showed reduced toxicity over cynaropicrin, but also lost antitrypanosomal activity.

  9. Designing synthetic biology.

    Science.gov (United States)

    Agapakis, Christina M

    2014-03-21

    Synthetic biology is frequently defined as the application of engineering design principles to biology. Such principles are intended to streamline the practice of biological engineering, to shorten the time required to design, build, and test synthetic gene networks. This streamlining of iterative design cycles can facilitate the future construction of biological systems for a range of applications in the production of fuels, foods, materials, and medicines. The promise of these potential applications as well as the emphasis on design has prompted critical reflection on synthetic biology from design theorists and practicing designers from many fields, who can bring valuable perspectives to the discipline. While interdisciplinary connections between biologists and engineers have built synthetic biology via the science and the technology of biology, interdisciplinary collaboration with artists, designers, and social theorists can provide insight on the connections between technology and society. Such collaborations can open up new avenues and new principles for research and design, as well as shed new light on the challenging context-dependence-both biological and social-that face living technologies at many scales. This review is inspired by the session titled "Design and Synthetic Biology: Connecting People and Technology" at Synthetic Biology 6.0 and covers a range of literature on design practice in synthetic biology and beyond. Critical engagement with how design is used to shape the discipline opens up new possibilities for how we might design the future of synthetic biology.

  10. Apparent Consumption vs. Total Consumption--A Lead-Acid Battery Case Study

    Science.gov (United States)

    Wilburn, David R.; Buckingham, David A.

    2006-01-01

    Introduction: This report compares estimates of U.S. apparent consumption of lead with estimates of total U.S. consumption of this mineral commodity from a materials flow perspective. The difference, attributed to the amount of lead contained in imported and exported products, was found to be significant for this sector. The study also assesses the effects of including mineral commodities incorporated in manufactured products on the interpretation of observed trends in minerals consumption and trade. Materials flow is a systems approach to understanding what happens to the materials we use from the time a material is extracted, through its processing and manufacturing, to its ultimate disposition. The U.S. Geological Survey (USGS) provides accurate and detailed mineral production and mineral commodity consumption statistics that are essential for government, nongovernment organizations, and the public to gain a better understanding of how and where materials are used and their effect on the environment and society. Published statistics on mineral apparent consumption are limited to estimates of consumption of raw material forms (ore, concentrate, and [or] refined metal). For this study, apparent consumption is defined as mine production + secondary refined production + imports (concentrates and refined metal) ? exports (concentrates and refined metal) + adjustments for government and industry stock changes. These estimates do not account for the amount of mineral commodities contained in manufactured products that are imported to the United States, nor do they deduct the amount of these mineral commodities contained in manufactured products that are exported from the United States. When imports or exports of manufactured products contribute significantly to the total use of a particular raw material, an estimate of consumption that does not consider the incorporated forms of these mineral commodities within imported or exported manufactured products can be either

  11. Experimental studies of dynamic impact response with scale models of lead shielded radioactive material shipping containers

    International Nuclear Information System (INIS)

    Robinson, R.A.; Hadden, J.A.; Basham, S.J.

    1978-01-01

    Preliminary experimental studies of dynamic impact response of scale models of lead-shielded radioactive material shipping containers are presented. The objective of these studies is to provide DOE/ECT with a data base to allow the prediction of a rational margin of confidence in overviewing and assessing the adequacy of the safety and environmental control provided by these shipping containers. Replica scale modeling techniques were employed to predict full scale response with 1/8, 1/4, and 1/2 scale models of shipping containers that are used in the shipment of spent nuclear fuel and high level wastes. Free fall impact experiments are described for scale models of plain cylindrical stainless steel shells, stainless steel shells filled with lead, and replica scale models of radioactive material shipping containers. Dynamic induced strain and acceleration measurements were obtained at several critical locations on the models. The models were dropped from various heights, attitudes to the impact surface, with and without impact limiters and at uniform temperatures between -40 and 175 0 C. In addition, thermal expansion and thermal gradient induced strains were measured at -40 and 175 0 C. The frequency content of the strain signals and the effect of different drop pad compositions and stiffness were examined. Appropriate scale modeling laws were developed and scaling techniques were substantiated for predicting full scale response by comparison of dynamic strain data for 1/8, 1/4, and 1/2 scale models with stainless steel shells and lead shielding

  12. Ischemic heart disease risk factors in lead exposed workers: research study.

    Science.gov (United States)

    Ghiasvand, Masoumeh; Aghakhani, Kamran; Salimi, Ahmad; Kumar, Ranjit

    2013-01-01

    Review of other epidemiological studies reveal inconsistent results of relationships between high blood lead level and risk of hypertension, hyperlipidemia and hyperglycemia. In this study we wanted to find if there is a relationship between blood lead level and these ischemic heart disease risk factors. This cross-sectional study was conducted in a battery recycling plant, and 497 male workers with the mean age of 41.7 (±6.50) years were recruited from all over the plant (those from the products and maintenance sections were classed as "high lead exposed group" and those from amongst the office, laboratory, security services and food services sections as "low lead exposed group"). Personal information such as demographics and work history was obtained through a questionnaire. Mean (±Standard deviation) for quantitative variables, Frequency (Percent) for qualitative variables, and Odd's ratio (OR) with 95% confidence interval (95% CI) for estimating the effect of blood lead level on lipid profile[triglyceride (TG), cholesterol(CHOL), low density lipoprotein - Cholesterol(LDL-C),high density lipoprotein -Cholesterol(HDL-C)], hypertension(HTN) and fasting blood sugar (FBS) level. Logistic regression modeling was used for multivariate analysis and adjusting the effect of different variables (age, body mass index(BMI), eating habits, cigarette smoking). The mean Blood Lead Level (BLL) was >40 μg/dl in 281 (56.6%) subjects, ≤40 μg in 216 (43.4%) subjects and the mean BLL was 43.3 μg/dl (n = 497). The mean job experience involving lead exposure was 13 years. There was no significant correlation between BLL and FBS (p = 0.68), between BLL and TG (P = 0.32), between BLL and HDL-C (p = 0.49), between BLL and LDL-C (p = 0.17), between BLL and CHOL(p = 0.96), between BLL and systolic blood pressure (p = 0.12). The adjusted Odd's ratio for the effect of BLL >40.0 μg/dl on diastolic blood pressure was1.03 (95% CI: 1.01-1.05) with p

  13. A Comparative Study of Lithium Ion to Lead Acid Batteries for use in UPS Applications

    DEFF Research Database (Denmark)

    Stan, Ana-Irina; Swierczynski, Maciej Jozef; Stroe, Daniel Ioan

    2014-01-01

    Uninterruptible power supply (UPS) systems have incorporated in their structure an electrochemical battery which allows for smooth power supply when a power failure occurs. In general, UPS systems are based on lead acid batteries; mainly a valve regulated lead acid (VRLA) battery. Recently, lithium...... ion batteries are getting more and more attention for their use in the back-up power systems and UPSs, because of their superior characteristics, which include increased safety and higher gravimetric and volumetric energy densities. This fact allows them to be smaller in size and weight less than VRLA...... batteries, which are currently used in UPS applications. The main purpose of this paper is to analyze how Li-ion batteries can become a useful alternative to present VRLA. In this study, three different electrochemical battery technologies were investigated; two of the most appealing Li-ion chemistries...

  14. Public sector accounting in the education syllabi of leading chartered accountant professional bodies: A comparative study

    Directory of Open Access Journals (Sweden)

    Ahmed Mohammadali-Haji

    2016-05-01

    Full Text Available Public sector accounting has emerged as an area of concern within the sphere of professional accounting education. The International Federation of Accountants (IFAC allows its member bodies to apply discretion in the application of public sector accounting education requirements. This study explored the nature and extent to which public sector accounting features in the education syllabi of the leading chartered accountant professional bodies that form part of the IFAC contingent. By following an explorative approach, the study identified international trends within the ambit of public sector accounting education and provides guidance for other professional bodies in assessing the nature and extent of their public sector accounting education requirements

  15. Metal immobilization in soils using synthetic zeolites

    NARCIS (Netherlands)

    Osté, L.A.; Lexmond, T.M.; Riemsdijk, van W.H.

    2002-01-01

    In situ immobilization of heavy metals in contaminated soils is a technique to improve soil quality. Synthetic zeolites are potentially useful additives to bind heavy metals. This study selected the most effective zeolite in cadmium and zinc binding out of six synthetic zeolites (mordenite-type,

  16. Quantum transport in coupled resonators enclosed synthetic magnetic flux

    International Nuclear Information System (INIS)

    Jin, L.

    2016-01-01

    Quantum transport properties are instrumental to understanding quantum coherent transport processes. Potential applications of quantum transport are widespread, in areas ranging from quantum information science to quantum engineering, and not restricted to quantum state transfer, control and manipulation. Here, we study light transport in a ring array of coupled resonators enclosed synthetic magnetic flux. The ring configuration, with an arbitrary number of resonators embedded, forms a two-arm Aharonov–Bohm interferometer. The influence of magnetic flux on light transport is investigated. Tuning the magnetic flux can lead to resonant transmission, while half-integer magnetic flux quantum leads to completely destructive interference and transmission zeros in an interferometer with two equal arms. -- Highlights: •The light transport is investigated through ring array of coupled resonators enclosed synthetic magnetic field. •Aharonov–Bohm ring interferometer of arbitrary configuration is investigated. •The half-integer magnetic flux quantum leads to destructive interference and transmission zeros for two-arm at equal length. •Complete transmission is available via tuning synthetic magnetic flux.

  17. Increasing synthetic serum substitute (SSS) concentrations in P1 glucose/phosphate-free medium improves implantation rate: a comparative study.

    Science.gov (United States)

    Ben-Yosef, D; Yovel, I; Schwartz, T; Azem, F; Lessing, J B; Amit, A

    2001-11-01

    To assess the comparative efficacy of IVF medium (MediCult, with 5.2 mM glucose) and a glucose/phosphate-free medium, P1 (Irvine Scientific), and to investigate the influence of increasing the serum supplementation (synthetic serum substitute; SSS; Irvine Scientific) to P1 on embryo development and implantation. Patients were randomly assigned to IVF medium (Group 1, cycles n = 172) or P1 supplemented with 10% SSS (Group 2, cycles n = 229) according to the medium scheduled for use on the day of oocyte retrieval. Another 555 IVF consequent cycles (Group 3) were performed using increased SSS concentrations (20%) in P1 medium. In this large series of IVF cycles, we herein demonstrate that significantly higher pregnancy and implantation rates were found when embryos were cultured in glucose/phosphate-free medium P1 supplemented with 20% SSS compared to supplementation with the lower SSS concentration and with IVF medium.

  18. LEADING WITH LEADING INDICATORS

    International Nuclear Information System (INIS)

    PREVETTE, S.S.

    2005-01-01

    This paper documents Fluor Hanford's use of Leading Indicators, management leadership, and statistical methodology in order to improve safe performance of work. By applying these methods, Fluor Hanford achieved a significant reduction in injury rates in 2003 and 2004, and the improvement continues today. The integration of data, leadership, and teamwork pays off with improved safety performance and credibility with the customer. The use of Statistical Process Control, Pareto Charts, and Systems Thinking and their effect on management decisions and employee involvement are discussed. Included are practical examples of choosing leading indicators. A statistically based color coded dashboard presentation system methodology is provided. These tools, management theories and methods, coupled with involved leadership and employee efforts, directly led to significant improvements in worker safety and health, and environmental protection and restoration at one of the nation's largest nuclear cleanup sites

  19. A new lead from genetic studies in depressed siblings: assessing studies of chromosome 3.

    Science.gov (United States)

    Hamilton, Steven P

    2011-08-01

    Studies by Breen et al. and Pergadia et al. find evidence for genetic linkage between major depressive disorder and the same region on chromosome 3. The linked region contains the gene GRM7, which encodes a protein for the metabotropic glutamate receptor 7 (mGluR7). Both studies used affected sibling pairs, and neither was able to replicate its finding using association studies in individuals from larger population-based studies. Other family-based studies have also failed to find a signal in this region. Furthermore, there are some differences in how the phenotype was classified, with Breen et al. finding evidence only in the most severely affected patients. Nonetheless, the finding is not without other substantive support. A meta-analysis of 3,957 case subjects with major depressive disorder and 3,428 control subjects from the Sequenced Treatment Alternatives to Relieve Depression (STAR*D), Genetics of Recurrent Early-onset Depression (GenRED), and the Genetic Association Information Network-MDD (GAIN-MDD) data sets demonstrated a region of association for major depressive disorder within GRM7. Thus, the significance of this finding remains uncertain, although it points to a gene that might hold significant promise for further developments in studying the pathophysiology and treatment of major depressive disorder.

  20. Isotopically labeled sulfur compounds and synthetic selenium and tellurium analogues to study sulfur metabolism in marine bacteria

    Directory of Open Access Journals (Sweden)

    Nelson L. Brock

    2013-05-01

    Full Text Available Members of the marine Roseobacter clade can degrade dimethylsulfoniopropionate (DMSP via competing pathways releasing either methanethiol (MeSH or dimethyl sulfide (DMS. Deuterium-labeled [2H6]DMSP and the synthetic DMSP analogue dimethyltelluriopropionate (DMTeP were used in feeding experiments with the Roseobacter clade members Phaeobacter gallaeciensis DSM 17395 and Ruegeria pomeroyi DSS-3, and their volatile metabolites were analyzed by closed-loop stripping and solid-phase microextraction coupled to GC–MS. Feeding experiments with [2H6]DMSP resulted in the incorporation of a deuterium label into MeSH and DMS. Knockout of relevant genes from the known DMSP demethylation pathway to MeSH showed in both species a residual production of [2H3]MeSH, suggesting that a second demethylation pathway is active. The role of DMSP degradation pathways for MeSH and DMS formation was further investigated by using the synthetic analogue DMTeP as a probe in feeding experiments with the wild-type strain and knockout mutants. Feeding of DMTeP to the R. pomeroyi knockout mutant resulted in a diminished, but not abolished production of demethylation pathway products. These results further corroborated the proposed second demethylation activity in R. pomeroyi. Isotopically labeled [2H3]methionine and 34SO42−, synthesized from elemental 34S8, were tested to identify alternative sulfur sources besides DMSP for the MeSH production in P. gallaeciensis. Methionine proved to be a viable sulfur source for the MeSH volatiles, whereas incorporation of labeling from sulfate was not observed. Moreover, the utilization of selenite and selenate salts by marine alphaproteobacteria for the production of methylated selenium volatiles was explored and resulted in the production of numerous methaneselenol-derived volatiles via reduction and methylation. The pathway of selenate/selenite reduction, however, proved to be strictly separated from sulfate reduction.

  1. Spectroscopic studies of copper doped alkaline earth lead zinc phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Sastry, S. Sreehari, E-mail: sreeharisastry@yahoo.com [Department of Physics, Acharya Nagarjuna University, Nagarjunanagar 522510 (India); Rao, B. Rupa Venkateswara [Department of Physics, Acharya Nagarjuna University, Nagarjunanagar 522510 (India); Department of Physics, V.R. Siddhartha Engineering College, Vijayawada 52007 (India)

    2014-02-01

    In this paper spectroscopic investigation of Cu{sup 2+} doped alkaline earth lead zinc phosphate glasses was done through the spectroscopic techniques like X-ray diffraction, Ultra Violet (UV) absorption Spectroscopy, Electron Paramagnetic Resonance (EPR – X band), Fourier Transform Infra Red (FTIR) and Raman Spectroscopy. Alkaline earth lead zinc phosphate glasses containing 0.1% copper oxide (CuO) were prepared by the melt quenching technique. Spectroscopic studies indicated that there is a greater possibility for the copper ions to exist in Cu{sup 2+} state in these glasses. The optical absorption spectra indicated that the absorption peak of Cu{sup 2+} is a function of composition. The maxima absorption peak was reported at 862 nm for strontium lead zinc phosphate glass. Bonding parameters were calculated for the optical and EPR data. All these spectral results indicated clearly that there are certain structural changes in the present glass system with different alkaline earth contents. The IR and Raman spectra noticed the breaking of the P–O–P bonds and creating more number of new P–O–Cu bonds.

  2. Spectroscopic studies of copper doped alkaline earth lead zinc phosphate glasses

    International Nuclear Information System (INIS)

    Sastry, S. Sreehari; Rao, B. Rupa Venkateswara

    2014-01-01

    In this paper spectroscopic investigation of Cu 2+ doped alkaline earth lead zinc phosphate glasses was done through the spectroscopic techniques like X-ray diffraction, Ultra Violet (UV) absorption Spectroscopy, Electron Paramagnetic Resonance (EPR – X band), Fourier Transform Infra Red (FTIR) and Raman Spectroscopy. Alkaline earth lead zinc phosphate glasses containing 0.1% copper oxide (CuO) were prepared by the melt quenching technique. Spectroscopic studies indicated that there is a greater possibility for the copper ions to exist in Cu 2+ state in these glasses. The optical absorption spectra indicated that the absorption peak of Cu 2+ is a function of composition. The maxima absorption peak was reported at 862 nm for strontium lead zinc phosphate glass. Bonding parameters were calculated for the optical and EPR data. All these spectral results indicated clearly that there are certain structural changes in the present glass system with different alkaline earth contents. The IR and Raman spectra noticed the breaking of the P–O–P bonds and creating more number of new P–O–Cu bonds

  3. Long term mortality study of chromate pigment workers who suffered lead poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Davies, J.M.

    1984-05-01

    Long term mortality was studied in a group of 57 chromate pigment workers who suffered clinical lead poisoning, mostly between 1930 and 1945. One death was attributed to lead poisoning and there were significant excesses of deaths from nephritis (observed/expected 3/0.24) and cerebrovascular disease (9/2.20), as well as non-significant excesses for respiratory diseases (7/3.59) and accidents and violence (3/1.13). The deaths from nephritis followed long spells of service exceeding 10 years. Poisoning appeared to have more adverse long term effects on older workers: 15 men aged 40 or over at the time of acute poisoning experienced generally high mortality, and 30 years later or by the end of 1981 only two survived instead of the seven expected. The risk of cerebrovascular disease appeared to be unrelated to duration of exposure and affected even men employed for under one year. Excluding the 57 lead poisoned men, other contemporary workers at the factories showed no excess mortality from cerebrovascular disease.

  4. A cohort mortality study of lead-exposed workers in the USA, Finland and the UK.

    Science.gov (United States)

    Steenland, Kyle; Barry, Vaughn; Anttila, Ahti; Sallmén, Markku; McElvenny, Damien; Todd, A C; Straif, Kurt

    2017-11-01

    To investigate further whether inorganic lead is a carcinogen among adults, or associated with increased blood pressure and kidney damage, via a large mortality study. We conducted internal analyses via Cox regression of mortality in three cohorts of lead-exposed workers with blood lead (BL) data (USA, Finland, UK), including over 88 000 workers and over 14 000 deaths. Our exposure metric was maximum BL. We also conducted external analyses using country-specific background rates. The combined cohort had a median BL of 26 µg/dL, a mean first-year BL test of 1990 and was 96% male. Fifty per cent had more than one BL test (mean 7). Significant (p40 µg/dL; for bladder, lung and larynx cancer; and for COPD. In a small subsample of the US cohort (n=115) who were interviewed, we found no association between smoking and BL. We found strong positive mortality trends, with increasing BL level, for several outcomes in internal analysis. Many of these outcomes are associated with smoking, for which we had no data. A borderline trend was found for brain cancer, not associated with smoking. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  5. Synthetic food coloring and behavior: a dose response effect in a double-blind, placebo-controlled, repeated-measures study.

    Science.gov (United States)

    Rowe, K S; Rowe, K J

    1994-11-01

    To establish whether there is an association between the ingestion of synthetic food colorings and behavioral change in children referred for assessment of "hyperactivity." From approximately 800 children referred to the Royal Children's Hospital (Melbourne) for assessment of suspected hyperactivity, 200 were included in a 6-week open trial of a diet free of synthetic food coloring. The parents of 150 children reported behavioral improvement with the diet, and deterioration on the introduction of foods noted to contain synthetic coloring. A 30-item behavioral rating inventory was devised from an examination of the clinical histories of 50 suspected reactors. Thirty-four other children (23 suspected reactors, 11 uncertain reactors) and 20 control subjects, aged 2 to 14 years, were studied. A 21-day, double-blind, placebo-controlled, repeated-measures study used each child as his or her own control. Placebo, or one of six dose levels of tartrazine (1, 2, 5, 10, 20, 50 mg), was administered randomly each morning, and behavioral ratings were recorded by parents at the end of each 24 hours. The study identified 24 children as clear reactors (19 of 23 "suspected reactors," 3 of 11 "uncertain reactors," and 2 of 20 "control subjects"). They were irritable and restless and had sleep disturbance. Significant reactions were observed at all six dose levels. A dose response effect was obtained. With a dose increase greater than 10 mg, the duration of effect was prolonged. Behavioral changes in irritability, restlessness, and sleep disturbance are associated with the ingestion of tartrazine in some children. A dose response effect was observed.

  6. Experimental and theoretical studies on radiation protective effect of a lighter non-lead protective apron

    International Nuclear Information System (INIS)

    Takano, Yoshihisa; Ono, Koji; Okazaki, Keiichiro

    2005-01-01

    Non-lead aprons using composite materials are often used for radiation protective aprons instead of heavy lead aprons. However, the protective effect of the lighter, non-lead aprons has not been well evaluated, and it is not yet clear how they compare with lead aprons. Therefore, we investigated the protective performance of non-lead aprons theoretically and experimentally by comparing them with lead aprons under clinical conditions. We measured the energy spectra for direct and scattered-rays passing through protective aprons or not, and measured doses with glass dosimeters for validation of theoretical calculations based on the energy spectra. We found that the protective effect of non-lead aprons was higher than that of lead aprons at X-ray of tube voltages of 70-100 kV, which are often used for radiography and fluorography. This demonstrated that the non-lead aprons are more useful in many situations than heavy lead aprons. (author)

  7. Synthetic Developments of Nontoxic Quantum Dots.

    Science.gov (United States)

    Das, Adita; Snee, Preston T

    2016-03-03

    Semiconductor nanocrystals, or quantum dots (QDs), are candidates for biological sensing, photovoltaics, and catalysis due to their unique photophysical properties. The most studied QDs are composed of heavy metals like cadmium and lead. However, this engenders concerns over heavy metal toxicity. To address this issue, numerous studies have explored the development of nontoxic (or more accurately less toxic) quantum dots. In this Review, we select three major classes of nontoxic quantum dots composed of carbon, silicon and Group I-III-VI elements and discuss the myriad of synthetic strategies and surface modification methods to synthesize quantum dots composed of these material systems. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. The effects of lead time and visual aids in TTO valuation: a study of the EQ-VT framework

    NARCIS (Netherlands)

    N. Luo (Nan); M. Li (Minghui); E.A. Stolk (Elly); N. Devlin (Nancy)

    2013-01-01

    markdownabstract__Abstract__ __Background__ The effect of lead time in time trade-off (TTO) valuation is not well understood. The purpose of this study was to investigate the effects on health-state valuation of the length of lead time and the way the lead-time TTO task is displayed visually.

  9. Technological study report on synthetic evaluation for FBR cycle. The report of the feasibility studies on commercialized FBR cycle system. Phase 1

    International Nuclear Information System (INIS)

    Shinoda, Yoshihiko; Ohtaki, Akira; Kofuji, Hirohide; Ono, Kiyoshi; Hirao, Kazunori

    2001-03-01

    This report is intended to explain the outline of the characteristic evaluation work on various FR cycle system concepts, following the design work, in the 1st phase of the JNC's 'Feasibility Study on Commercialized Fast Reactor Cycle System (the F/S)' (from 1999 to March 2001). The purpose of this characteristic evaluation is to reveal the performance of candidate FR cycle systems. For this synthetic estimation, six viewpoints, such as Economics, Effective utilization of uranium resource, Reduction of environmental impact, Safety, Proliferation resistance, and Technological feasibility, are selected. In addition, aiming at the practical use in phase 2, we examined an application to FBR research and development of cost benefit analysis method used for the policy evaluation. Furthermore, long-term nuclear material mass flow was analyzed and the scenario of 'FBR application for the hydrogen production' is proposed, considering how FBR would be utilized for the 21st century. And, a database including the various documents and data used for evaluation was constructed. (author)

  10. Synthetic biological networks

    International Nuclear Information System (INIS)

    Archer, Eric; Süel, Gürol M

    2013-01-01

    Despite their obvious relationship and overlap, the field of physics is blessed with many insightful laws, while such laws are sadly absent in biology. Here we aim to discuss how the rise of a more recent field known as synthetic biology may allow us to more directly test hypotheses regarding the possible design principles of natural biological networks and systems. In particular, this review focuses on synthetic gene regulatory networks engineered to perform specific functions or exhibit particular dynamic behaviors. Advances in synthetic biology may set the stage to uncover the relationship of potential biological principles to those developed in physics. (review article)

  11. CFD study on NACA 4415 airfoil implementing spherical and sinusoidal Tubercle Leading Edge.

    Science.gov (United States)

    Aftab, S M A; Ahmad, K A

    2017-01-01

    The Humpback whale tubercles have been studied for more than a decade. Tubercle Leading Edge (TLE) effectively reduces the separation bubble size and helps in delaying stall. They are very effective in case of low Reynolds number flows. The current Computational Fluid Dynamics (CFD) study is on NACA 4415 airfoil, at a Reynolds number 120,000. Two TLE shapes are tested on NACA 4415 airfoil. The tubercle designs implemented on the airfoil are sinusoidal and spherical. A parametric study is also carried out considering three amplitudes (0.025c, 0.05c and 0.075c), the wavelength (0.25c) is fixed. Structured mesh is utilized to generate grid and Transition SST turbulence model is used to capture the flow physics. Results clearly show spherical tubercles outperform sinusoidal tubercles. Furthermore experimental study considering spherical TLE is carried out at Reynolds number 200,000. The experimental results show that spherical TLE improve performance compared to clean airfoil.

  12. BATCH AND FIXED BED ADSORPTION STUDIES OF LEAD (II CATIONS FROM AQUEOUS SOLUTIONS ONTO GRANULAR ACTIVATED CARBON DERIVED FROM MANGOSTANA GARCINIA SHELL

    Directory of Open Access Journals (Sweden)

    Zaira Zaman Chowdhury,

    2012-05-01

    Full Text Available The feasibility of granular activated carbon (GAC derived from Mangostene (Mangostana garcinia fruit shell to remove lead, Pb2+ cations was investigated in batch and fixed bed sorption systems. Batch experiments were carried out to study equilibrium isotherms, kinetics, and thermodynamics by using an initial lead (Pb2+ ions concentration of 50 to 100 mg/L at pH 5.5. Equilibrium data were fitted using Langmuir, Freundlich, and Temkin linear equation models at temperatures 30°C, 50°C, and 70°C. Langmuir maximum monolayer sorption capacity was 25.00 mg/g at 30°C. The experimental data were best represented by pseudo-second-order and Elovich models. The sorption process was found to be feasible, endothermic, and spontaneous. In column experiments, the effects of initial cation concentration (50 mg/L, 70 mg/L, and 100 mg/L, bed height (4.5 cm and 3 cm, and flow rate (1 mL/min and 3 mL/min on the breakthrough characteristics were evaluated. Breakthrough curves were further analyzed by using Thomas and Yoon Nelson models to study column dynamics. The column was regenerated and reused consecutively for four cycles. The result demonstrated that the prepared activated carbon was suitable for removal of Pb2+ from synthetic aqueous solution using batch, as well as fixed bed sorption systems.

  13. A Comprehensive Study on Fast Dispersible and Slow-Releasing Characteristic of Orange Peel Pectin in Relation to Established Synthetic Polymer.

    Science.gov (United States)

    Srivastava, Pranati; Singh, Mahendra; Bhargava, Shilpi

    2017-10-01

    In the present work, the method to extract, isolate, and characterize orange peel pectin using soxhlation, and thereafter, the use of this polymer-polymer in the formulation of fast dispersable and slow-releasing tablet has been studied. Thereafter, the evaluation and comparison of fast dispersible/slow-releasing tablets using orange peel pectin versus prepared using sodium starch glycolate (SSG) were carried out. In the present investigation, extraction methodology was employed for isolation of pectin from orange peels. Four different batches with each polymer were prepared with varying concentration of superdisintegrant and bulking agent using diclofenac sodium as model drug. Diclofenac sodium stands as easily available, cheap, and good candidate to demonstrate disintegrant property. The formulation involved wet granulation method for the preparation of tablets of each batch. The tablets were evaluated for hardness, friability, thickness, wetting time, deaggregation time, and in vitro release characteristic data. It was observed that parameters for batch O2* were comparable with that of synthetic superdisintegrant. This batch gave around 92.12% drug release in period of 90 min. The study showed that orange peel pectin could be a potential candidate for formulation of orodispersible dosage forms in competence to SSG, which is established superdisintegrant. The results led to the conclusion that the use of natural polymers in formulation of pharmaceutical dosage form can be put into practice on industrial scale meeting the similar requirements as done by synthetic polymers. The present work aims to demonstrate and establish the use of naturally derived polymer, i.e., orange peel pectin as a superdisintegrant. The extraction methodology has been discussed followed by comparative analysis with a synthetic polymer. Abbreviations used: O1-O2: Batches Containing Orange peel pectin, S1-S2: Batches containing SSG, SSG: Sodium starch glycolate, NDDS: Novel drug delivery

  14. Synthetic hydroxyapatites doped with Zn(II) studied by X-ray diffraction, infrared, Raman and thermal analysis

    Science.gov (United States)

    Guerra-López, José R.; Echeverría, Gustavo A.; Güida, Jorge A.; Viña, Raúl; Punte, Graciela

    2015-06-01

    Calcium hydroxyapatite (CaHap) formation when different amounts of Zn(II) are present in the mother solution has been investigated by atomic absorption, infrared and Raman spectroscopies, X-ray diffraction and thermal analysis (DTA and TG). The studied samples have been synthesized at T=95 °C and pH 9 in air. The analysis of the results have shown that the pure CaHap sample crystallizes in the monoclinic form P21/b. Concentrations up to 20% of Zn(II) in the mother solution, equivalent to smaller concentrations in solid (up to 9.1% in wt), favor the formation of the hexagonal apatite, P63/m, while Zn(II) concentrations higher than 20% in solution help an amorphous phase development where vibrational spectra indicated coexistence of two phases: an apatite and ZnNH4PO4·H2O. Infrared data of thermal treated samples endorse that HPO42- ion had not been incorporated in Zn(II) doped samples during the synthesis process. Present results also allow to conclude that Zn(II) cation exhibits a preference to occupy the Ca2 site of the apatite structure and induces water adsorption and a small quantity of CO32- cation incorporation, leading to formation of a less crystalline Ca deficient apatite.

  15. Part I: A comparative study of bismuth-modified screen-printed electrodes for lead detection

    Energy Technology Data Exchange (ETDEWEB)

    Calvo Quintana, Josefina [Dipartimento di Scienze e Tecnologie Chimiche, Universita di Roma Tor Vergata, Via della Ricerca Scientifica, 00133 Rome (Italy); Consorzio Interuniversitario Biostrutture e Biosistemi ' INBB' , Viale Medaglie d' Oro 305, 00136 Rome (Italy); Arduini, Fabiana, E-mail: fabiana.arduini@uniroma2.it [Dipartimento di Scienze e Tecnologie Chimiche, Universita di Roma Tor Vergata, Via della Ricerca Scientifica, 00133 Rome (Italy); Consorzio Interuniversitario Biostrutture e Biosistemi ' INBB' , Viale Medaglie d' Oro 305, 00136 Rome (Italy); Amine, Aziz [Faculte des Sciences et Techniques, B.P.146, Mohammadia, Morocco, Rome (Italy); Punzo, Francesco; Destri, Giovanni Li [LAMSUN and CSGI at Dipartimento di Scienze Chimiche, Universita degli Studi di Catania, Viale A. Doria 6, 95125, Catania (Italy); Bianchini, Chiara [Dipartimento di Ingegneria Chimica Materiali Ambienti dell' Universita degli Studi ' La Sapienza' di Roma, via Eudossiana 18, 00184 Rome (Italy); Zane, Daniela; Curulli, Antonella [Istituto per lo Studio dei Materiali Nanostrutturati (ISMN)-CNR,via del Castro Laurenziano 7, 00161 Rome (Italy); Palleschi, Giuseppe; Moscone, Danila [Dipartimento di Scienze e Tecnologie Chimiche, Universita di Roma Tor Vergata, Via della Ricerca Scientifica, 00133 Rome (Italy); Consorzio Interuniversitario Biostrutture e Biosistemi ' INBB' , Viale Medaglie d' Oro 305, 00136 Rome (Italy)

    2011-11-30

    Highlights: Black-Right-Pointing-Pointer 'In situ' Bi-SPE has higher sensitivity than 'ex situ' Bi-SPE and 'Bi{sub 2}O{sub 3} bulk' SPE. Black-Right-Pointing-Pointer Electrochemical treatment of SPE before Bi film deposition allows one to reach low LOD. Black-Right-Pointing-Pointer The linearity of Pb{sup 2+} in HCl and HClO{sub 4} is greatly affected by the ionic strength. Black-Right-Pointing-Pointer Satisfactory values of the recovery percentage were obtained in drinking water samples. - Abstract: Lead determination was carried out in the frame of the European Union project Biocop ( (www.biocop.org)) using a bismuth-modified screen-printed electrode (Bi-SPE) and the stripping analysis technique. In order to choose a sensitive Bi-SPE for lead detection, an analytical comparative study of electrodes modified by Bi using 'in situ', 'ex situ' and 'bulk' procedures was carried out. On the basis of the results obtained, we confirmed that the 'in situ' procedure resulted in better analytical performances with respect to not only 'ex situ' but also to 'Bi{sub 2}O{sub 3} bulk' modified electrodes, allowing for a linear range of lead ion concentration from 0.5 to 100 {mu}g L{sup -1} and a detection limit of 0.15 {mu}g L{sup -1}. We demonstrated that, before the Bi film deposition, an oxidative electrochemical pre-treatment of the working electrode could be useful because it eliminates traces of lead in the graphite-ink, as shown with stripping measurements. It also improves the electrochemical performance of the electrodes as demonstrated with Electrochemical Impedance Spectroscopy (EIS) measurements. The influence of different analytical parameters, such as the electrolyte solution composition (acetate buffer, chloridric acid, nitric acid, perchloric acid) and the ionic strength was investigated in order to evaluate how to treat the sample before the analysis. The morphology of

  16. Part I: A comparative study of bismuth-modified screen-printed electrodes for lead detection

    International Nuclear Information System (INIS)

    Calvo Quintana, Josefina; Arduini, Fabiana; Amine, Aziz; Punzo, Francesco; Destri, Giovanni Li; Bianchini, Chiara; Zane, Daniela; Curulli, Antonella; Palleschi, Giuseppe; Moscone, Danila

    2011-01-01

    Highlights: ► “In situ” Bi-SPE has higher sensitivity than “ex situ” Bi-SPE and “Bi 2 O 3 bulk” SPE. ► Electrochemical treatment of SPE before Bi film deposition allows one to reach low LOD. ► The linearity of Pb 2+ in HCl and HClO 4 is greatly affected by the ionic strength. ► Satisfactory values of the recovery percentage were obtained in drinking water samples. - Abstract: Lead determination was carried out in the frame of the European Union project Biocop ( (www.biocop.org)) using a bismuth-modified screen-printed electrode (Bi-SPE) and the stripping analysis technique. In order to choose a sensitive Bi-SPE for lead detection, an analytical comparative study of electrodes modified by Bi using “in situ”, “ex situ” and “bulk” procedures was carried out. On the basis of the results obtained, we confirmed that the “in situ” procedure resulted in better analytical performances with respect to not only “ex situ” but also to “Bi 2 O 3 bulk” modified electrodes, allowing for a linear range of lead ion concentration from 0.5 to 100 μg L −1 and a detection limit of 0.15 μg L −1 . We demonstrated that, before the Bi film deposition, an oxidative electrochemical pre-treatment of the working electrode could be useful because it eliminates traces of lead in the graphite-ink, as shown with stripping measurements. It also improves the electrochemical performance of the electrodes as demonstrated with Electrochemical Impedance Spectroscopy (EIS) measurements. The influence of different analytical parameters, such as the electrolyte solution composition (acetate buffer, chloridric acid, nitric acid, perchloric acid) and the ionic strength was investigated in order to evaluate how to treat the sample before the analysis. The morphology of prepared “in situ” Bi-SPEs was also characterized by Atomic Force Microscopy (AFM). Finally, the Bi-SPEs were used to determine the concentration of lead ions in tap and commercial water

  17. Where Synthetic Biology Meets ET

    Science.gov (United States)

    Rothschild, Lynn J.

    2016-01-01

    Synthetic biology - the design and construction of new biological parts and systems and the redesign of existing ones for useful purposes - has the potential to transform fields from pharmaceuticals to fuels. Our lab has focused on the potential of synthetic biology to revolutionize all three major parts of astrobiology: Where do we come from? Where are we going? and Are we alone? For the first and third, synthetic biology is allowing us to answer whether the evolutionary narrative that has played out on planet earth is likely to have been unique or universal. For example, in our lab we are re-evolving the biosynthetic pathways of amino acids in order to understand potential capabilities of an early organism with a limited repertoire of amino acids and developing techniques for the recovery of metals from spent electronics on other planetary bodies. And what about the limits for life? Can we create organisms that expand the envelope for life? In the future synthetic biology will play an increasing role in human activities both on earth, in fields as diverse as human health and the industrial production of novel bio-composites. Beyond earth, we will rely increasingly on biologically-provided life support, as we have throughout our evolutionary history. In order to do this, the field will build on two of the great contributions of astrobiology: studies of the origin of life and life in extreme environments.

  18. Stereoscopy in cinematographic synthetic imagery

    Science.gov (United States)

    Eisenmann, Jonathan; Parent, Rick

    2009-02-01

    In this paper we present experiments and results pertaining to the perception of depth in stereoscopic viewing of synthetic imagery. In computer animation, typical synthetic imagery is highly textured and uses stylized illumination of abstracted material models by abstracted light source models. While there have been numerous studies concerning stereoscopic capabilities, conventions for staging and cinematography in stereoscopic movies have not yet been well-established. Our long-term goal is to measure the effectiveness of various cinematography techniques on the human visual system in a theatrical viewing environment. We would like to identify the elements of stereoscopic cinema that are important in terms of enhancing the viewer's understanding of a scene as well as providing guidelines for the cinematographer relating to storytelling. In these experiments we isolated stereoscopic effects by eliminating as many other visual cues as is reasonable. In particular, we aim to empirically determine what types of movement in synthetic imagery affect the perceptual depth sensing capabilities of our viewers. Using synthetic imagery, we created several viewing scenarios in which the viewer is asked to locate a target object's depth in a simple environment. The scenarios were specifically designed to compare the effectiveness of stereo viewing, camera movement, and object motion in aiding depth perception. Data were collected showing the error between the choice of the user and the actual depth value, and patterns were identified that relate the test variables to the viewer's perceptual depth accuracy in our theatrical viewing environment.

  19. Using synthetic biology to make cells tomorrow's test tubes.

    Science.gov (United States)

    Garcia, Hernan G; Brewster, Robert C; Phillips, Rob

    2016-04-18

    The main tenet of physical biology is that biological phenomena can be subject to the same quantitative and predictive understanding that physics has afforded in the context of inanimate matter. However, the inherent complexity of many of these biological processes often leads to the derivation of complex theoretical descriptions containing a plethora of unknown parameters. Such complex descriptions pose a conceptual challenge to the establishment of a solid basis for predictive biology. In this article, we present various exciting examples of how synthetic biology can be used to simplify biological systems and distill these phenomena down to their essential features as a means to enable their theoretical description. Here, synthetic biology goes beyond previous efforts to engineer nature and becomes a tool to bend nature to understand it. We discuss various recent and classic experiments featuring applications of this synthetic approach to the elucidation of problems ranging from bacteriophage infection, to transcriptional regulation in bacteria and in developing embryos, to evolution. In all of these examples, synthetic biology provides the opportunity to turn cells into the equivalent of a test tube, where biological phenomena can be reconstituted and our theoretical understanding put to test with the same ease that these same phenomena can be studied in the in vitro setting.

  20. Models for synthetic biology.

    Science.gov (United States)

    Kaznessis, Yiannis N

    2007-11-06

    Synthetic biological engineering is emerging from biology as a distinct discipline based on quantification. The technologies propelling synthetic biology are not new, nor is the concept of designing novel biological molecules. What is new is the emphasis on system behavior. The objective is the design and construction of new biological devices and systems to deliver useful applications. Numerous synthetic gene circuits have been created in the past decade, including bistable switches, oscillators, and logic gates, and possible applications abound, including biofuels, detectors for biochemical and chemical weapons, disease diagnosis, and gene therapies. More than fifty years after the discovery of the molecular structure of DNA, molecular biology is mature enough for real quantification that is useful for biological engineering applications, similar to the revolution in modeling in chemistry in the 1950s. With the excitement that synthetic biology is generating, the engineering and biological science communities appear remarkably willing to cross disciplinary boundaries toward a common goal.

  1. Technical Assessment: Synthetic Biology

    Science.gov (United States)

    2015-01-01

    Pfizer, Bausch & Lomb, Coca - Cola , and other Fortune 500 companies 8 Data estimated by the... financial prize for ideas to drive forward the production of a sensor relying on synthetic organisms that can detect exposure to 500 specific chemicals

  2. Comparative Study of Breakdown Voltage of Mineral, Synthetic and Natural Oils and Based Mineral Oil Mixtures under AC and DC Voltages

    Directory of Open Access Journals (Sweden)

    Abderrahmane Beroual

    2017-04-01

    Full Text Available This paper deals with a comparative study of AC and DC breakdown voltages of based mineral oil mixtures with natural and synthetic esters mainly used in high voltage power transformers. The goal was to analyze the performances of oil mixtures from the dielectric withstand point of view and to predict the behavior of transformers originally filled with mineral oil and re-filled with synthetic or natural ester oils when emptied for maintenance. The study concerns mixtures based on 20%, 50%, and 80% of natural and synthetic ester oils. AC breakdown voltages were measured using a sphere-sphere electrode system according to IEC 60156 specifications; the same specification was adopted for DC measurements since there is no standard specifications for this voltage waveform. A statistical analysis of the mean values, standard deviations, and histograms of breakdown voltage data was carried out. The Normal and Weibull distribution functions were used to analyze the experimental data and the best function that the data followed was used to estimate the breakdown voltage with risk of 1%, 10%, and 50% probability. It was shown that whatever the applied voltage waveforms, ester oils always have a significantly higher breakdown voltage than mineral oil. The addition of only 20% of natural or synthetic ester oil was sufficient to considerably increase the breakdown voltage of mineral oil. The dielectric strength of such a mixture is much higher than that of mineral oil alone and can reach that of ester oils. From the point of view of dielectric strength, the mixtures constitute an option for improving the performance of mineral oil. Thus, re-filling of transformers containing up to 20% mineral oil residues with ester oils, does not present any problem; it is even advantageous when considering only the breakdown voltage. Under AC, the mixtures with natural ester always follow the behavior of vegetable oil alone. With the exception of the 20% mixture of natural

  3. A comparative study of two statistical approaches for the analysis of real seismicity sequences and synthetic seismicity generated by a stick-slip experimental model

    Science.gov (United States)

    Flores-Marquez, Leticia Elsa; Ramirez Rojaz, Alejandro; Telesca, Luciano

    2015-04-01

    The study of two statistical approaches is analyzed for two different types of data sets, one is the seismicity generated by the subduction processes occurred at south Pacific coast of Mexico between 2005 and 2012, and the other corresponds to the synthetic seismic data generated by a stick-slip experimental model. The statistical methods used for the present study are the visibility graph in order to investigate the time dynamics of the series and the scaled probability density function in the natural time domain to investigate the critical order of the system. This comparison has the purpose to show the similarities between the dynamical behaviors of both types of data sets, from the point of view of critical systems. The observed behaviors allow us to conclude that the experimental set up globally reproduces the behavior observed in the statistical approaches used to analyses the seismicity of the subduction zone. The present study was supported by the Bilateral Project Italy-Mexico Experimental Stick-slip models of tectonic faults: innovative statistical approaches applied to synthetic seismic sequences, jointly funded by MAECI (Italy) and AMEXCID (Mexico) in the framework of the Bilateral Agreement for Scientific and Technological Cooperation PE 2014-2016.

  4. Degradation patterns of natural and synthetic textiles on a soil surface during summer and winter seasons studied using ATR-FTIR spectroscopy

    Science.gov (United States)

    Ueland, Maiken; Howes, Johanna M.; Forbes, Shari L.; Stuart, Barbara H.

    2017-10-01

    Textiles are a valuable source of forensic evidence and the nature and condition of textiles collected from a crime scene can assist investigators in determining the nature of the death and aid in the identification of the victim. Until now, much of the knowledge of textile degradation in forensic contexts has been based on the visual inspection of material collected from soil environments. The purpose of the current study was to investigate the potential of a more quantitative approach to the understanding of forensic textile degradation through the application of infrared spectroscopy. Degradation patterns of natural and synthetic textile materials as they were subjected to a natural outdoor environment in Australia were investigated. Cotton, polyester and polyester - cotton blend textiles were placed on a soil surface during the summer and winter seasons and were analysed over periods 1 and 1.5 years, respectively, and examined using attenuated total reflectance (ATR) spectroscopy. Statistical analysis of the spectral data obtained for the cotton material correlated with visual degradation and a difference in the onset of degradation between the summer and winter season was revealed. The synthetic material did not show any signs of degradation either visually or statistically throughout the experimental period and highlighted the importance of material type in terms of preservation. The cotton section from the polyester - cotton blend samples was found to behave in a similar manner to that of the 100% cotton samples, however principal component analysis (PCA) demonstrated that the degradation patterns were less distinct in both the summer and winter trial for the blend samples. These findings indicated that the presence of the synthetic material may have inhibited the degradation of the natural material. The use of statistics to analyse the spectral data obtained for textiles of forensic interest provides a better foundation for the interpretation of the data

  5. Molecular dynamics modeling the synthetic and biological polymers interactions pre-studied via docking: anchors modified polyanions interference with the HIV-1 fusion mediator.

    Science.gov (United States)

    Tsvetkov, Vladimir B; Serbin, Alexander V

    2014-06-01

    In previous works we reported the design, synthesis and in vitro evaluations of synthetic anionic polymers modified by alicyclic pendant groups (hydrophobic anchors), as a novel class of inhibitors of the human immunodeficiency virus type 1 (HIV-1) entry into human cells. Recently, these synthetic polymers interactions with key mediator of HIV-1 entry-fusion, the tri-helix core of the first heptad repeat regions [HR1]3 of viral envelope protein gp41, were pre-studied via docking in terms of newly formulated algorithm for stepwise approximation from fragments of polymeric backbone and side-group models toward real polymeric chains. In the present article the docking results were verified under molecular dynamics (MD) modeling. In contrast with limited capabilities of the docking, the MD allowed of using much more large models of the polymeric ligands, considering flexibility of both ligand and target simultaneously. Among the synthesized polymers the dinorbornen anchors containing alternating copolymers of maleic acid were selected as the most representative ligands (possessing the top anti-HIV activity in vitro in correlation with the highest binding energy in the docking). To verify the probability of binding of the polymers with the [HR1]3 in the sites defined via docking, various starting positions of polymer chains were tried. The MD simulations confirmed the main docking-predicted priority for binding sites, and possibilities for axial and belting modes of the ligands-target interactions. Some newly MD-discovered aspects of the ligand's backbone and anchor units dynamic cooperation in binding the viral target clarify mechanisms of the synthetic polymers anti-HIV activity and drug resistance prevention.

  6. Longitudinal Emergency Medical Technician Attributes and Demographic Study (LEADS) Design and Methodology.

    Science.gov (United States)

    Levine, Roger

    2016-12-01

    The objective of this study is to describe the Longitudinal Emergency Medical Technician (EMT) Attributes and Demographic Study (LEADS) design, instrument development, pilot testing, sampling procedures, and data collection methodology. Response rates are provided, along with results of follow-up surveys of non-responders (NRs) and a special survey of Emergency Medical Services (EMS) professionals who were not nationally certified. Annual surveys from 1999 to 2008 were mailed out to a random, stratified sample of nationally registered EMT-Basics and Paramedics. Survey weights were developed to reflect each respondent's probability of selection. A special survey of NRs was mailed out to individuals who did not respond to the annual survey to estimate the probable extent and direction of response bias. Individuals who indicated they were no longer in the profession were mailed a special exit survey to determine their reasons for leaving EMS. Given the large number of comparisons between NR and regular (annual) survey respondents, it is not surprising that some statistically significant differences were found. In general, there were few differences. However, NRs tended to report higher annual EMS incomes, were younger, healthier, more physically fit, and were more likely to report that they were not practicing EMS. Comparisons of the nationally certified EMS professionals with EMS professionals who were not nationally certified indicated that nationally certified EMS providers were younger, had less EMS experiences, earned less, were more likely to be female and work for private EMS services, and less likely to work for fire-based services. These differences may reflect state and local policy and practice, since many states and local agencies do not require maintenance of national certification as a requirement to practice. When these differences were controlled for statistically, there were few systematic differences between non-nationally certified and nationally

  7. Atmospheric deposition study in the area of Kardzhali lead-zinc plant based on moss analysis

    International Nuclear Information System (INIS)

    Hristozova, G.; Marinova, S.; Strelkova, L.P.; Goryajnova, Z.; Frontas'eva, M.V.; Stafilov, T.

    2015-01-01

    For the first time the moss biomonitoring technique was used to assess the environmental situation in the area affected by the lead-zinc plant as one of the most hazardous enterprises in Bulgaria. 77 Hypnum cupressiforme moss samples were collected in the Kardzhali municipality in the summer and autumn of 2011. The concentrations of a total of 47 elements were determined by means of instrumental epithermal neutron activation analysis (ENAA), atomic absorption spectrometry (AAS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). Multivariate statistics was applied to characterize the sources of elements detected in the samples. Four groups of elements were found. In comparison to the data averaged for the area outside of the town, the atmospheric deposition loads for the elements of industrial origin in Kardzhali, where the smelter chimney is located, were found to be much higher. Median levels of the measured concentrations of the most toxic metals (Pb, Zn, Cd, As, Cu, In, Sb) were extremely high in this hot spot when compared to the median Bulgarian cross-country data from the 2010-2011 European moss survey. GIS technology was used to produce element distribution maps illustrating deposition patterns of element pollutants in the study area. The results obtained contribute to the Bulgarian environmental research used to study and control the manufacturing processes of the lead-zinc plant in the town of Kardzhali.

  8. Integrating CHWs as Part of the Team Leading Diabetes Group Visits: A Randomized Controlled Feasibility Study.

    Science.gov (United States)

    Vaughan, Elizabeth M; Johnston, Craig A; Cardenas, Victor J; Moreno, Jennette P; Foreyt, John P

    2017-12-01

    Purpose The purpose of the study was to evaluate the feasibility of integrating Community Health Workers (CHWs) as part of the team leading diabetes group visits. Methods This was a randomized controlled study that integrated CHWs as part of the team leading diabetes group visits for low-income Hispanic adults (n = 50). Group visits met for 3 hours each month for a 6-month duration. Main measures included baseline and 6-month clinical outcomes (ie, A1C, lipids), concordance with 8 standard of care guidelines (ie, screens for cervical, breast, and colon cancer) from the US Preventive Task Force and American Diabetes Association, and participant acceptability. Results Compared to control participants, the intervention group resulted in significantly better clinical outcomes or guideline concordance for the following areas: target A1C levels, retinal eye exams, diabetes foot exams, mammograms, and urine microalbumin. Significantly more individuals in the control group gained weight, whereas a greater number of participants in the intervention group lost weight. Intervention participants found the group visits highly acceptable. Conclusions Integrating CHWs as part a comprehensive diabetes group visit program is a feasible and effective system-level intervention to improve glycemic control and achieve guideline concordance.

  9. Studying the shielding properties of lead glass composites using neutrons and gamma rays

    International Nuclear Information System (INIS)

    Osman, A.M.; El-Sarraf, M.A.; Abdel-Monem, A.M.; El-Sayed Abdo, A.

    2015-01-01

    Highlights: • Samples of sodalime silica glass loaded with different ratios of PbO were prepared. • Leaded glass composites were investigated for radiation shielding. • Experimental and theoretical attenuation parameters were studied. • Experimental and theoretical (MCNP5) results were in good agreement. - Abstract: The present work deals with the shielding properties of lead glass composites to find out its integrity for practical shielding applications and radiological safety. Composites of different lead oxide ratios (x = 0, 5, 10, 15 and 25 wt.%) have been prepared by the Nasser Glass and Crystal Company (Egypt). Attenuation measurements have been carried out using a collimated emitted beam from a fission 252 Cf (100 μg) neutron source, and the neutron–gamma spectrometer with stilbene scintillator. The pulse shape discriminating (P.S.D.) technique based on the zero cross-over method was used to discriminate between neutron and gamma-ray pulses. Thermal neutron fluxes were measured using the BF3 detector and thermal neutron detection system. The attenuation relations were used to evaluate fast neutron macroscopic effective removal cross-section Σ R-Meas (cm −1 ), gamma rays total attenuation coefficient μ (cm −1 ) and thermal neutron macroscopic cross-section Σ Meas (cm −1 ). Theoretical calculations have been achieved using MCNP5 code to calculate the same two parameters. Also, MERCSF-N program was used to calculate fast neutron macroscopic removal cross-section Σ R-MER (cm −1 ). Measured and MCNP5 calculated results have been compared and were found to be in reasonable agreement

  10. Synthetic biology: programming cells for biomedical applications.

    Science.gov (United States)

    Hörner, Maximilian; Reischmann, Nadine; Weber, Wilfried

    2012-01-01

    The emerging field of synthetic biology is a novel biological discipline at the interface between traditional biology, chemistry, and engineering sciences. Synthetic biology aims at the rational design of complex synthetic biological devices and systems with desired properties by combining compatible, modular biological parts in a systematic manner. While the first engineered systems were mainly proof-of-principle studies to demonstrate the power of the modular engineering approach of synthetic biology, subsequent systems focus on applications in the health, environmental, and energy sectors. This review describes recent approaches for biomedical applications that were developed along the synthetic biology design hierarchy, at the level of individual parts, of devices, and of complex multicellular systems. It describes how synthetic biological parts can be used for the synthesis of drug-delivery tools, how synthetic biological devices can facilitate the discovery of novel drugs, and how multicellular synthetic ecosystems can give insight into population dynamics of parasites and hosts. These examples demonstrate how this new discipline could contribute to novel solutions in the biopharmaceutical industry.

  11. A longitudinal study of the effects of long-term exposure to lead among lead battery factory workers in Taiwan (1989-1999)

    Energy Technology Data Exchange (ETDEWEB)

    Hsiao, Chun-Yin; Wu, Hong-Dar Isaac; Lai, Jim-Shoung; Kuo, Hsien-Wen [Institute of Environmental Health, China Medical College, No 91, Hsueh-Shin Rd., Taichung, Taiwan (China)

    2001-11-12

    The objective of this study was to assess the relationship between blood-lead levels (BLL), hematological, liver and renal indicators among workers in a lead battery factory in Taiwan over a 10-year period. Blood samples were taken periodically from 30 workers and BLL, HGB (hemoglobin), RBC (red blood cells), WBC (white blood cells) and HCT (hematocrit) were measured. Levels of GPT (alanine aminotransferase) and Crea (creatinine) in the blood were assessed to indicate liver and renal function, respectively. The results showed that there was a general decrease in BLL over the 10-year period (except for 1993). There was a similar trend for HCT, RBC and Crea. There was no significant trend for the other health indicators. Four generalized estimating equation (GEE) models [correlation model (A), threshold correlation model (B), instant change model (C) and lag change model (D)] were set up to demonstrate the causal relationship between BLL and the other health indicators. Models A and C showed that BLL correlated positively with RBC, but negatively with Crea. Model B showed that BLL correlated positively with GPT. There were no significant correlations of BLL with the other indicators. Models C and D, (GEE with logit link function to analyze the association between changes BLL and the other health indicators) showed that when BLL increased, RBC and HCT increased, both longitudinally and cross-sectionally. The authors conclude that long-term exposure to lead stimulates production of RBC and HCT, but the effect on liver and renal function was unclear.

  12. Mass Spectrometric Analysis of Synthetic Organic Pigments.

    Science.gov (United States)

    Sugaya, Naeko; Takahashi, Mitsuko; Sakurai, Katsumi; Tanaka, Nobuko; Okubo, Ichiro; Kawakami, Tsuyoshi

    2018-04-18

    Though synthetic organic colorants are used in various applications nowadays, there is the concern that impurities by-produced during the manufacturing and degradation products in some of these colorants are persistent organic pollutants and carcinogens. Thus, it is important to identify the synthetic organic colorants in various products, such as commercial paints, ink, cosmetics, food, textile, and plastics. Dyes, which are soluble in water and other solvents, could be analyzed by chromatographic methods. In contrast, it is difficult to analyze synthetic organic pigments by these methods because of their insolubility. This review is an overview of mass spectrometric analysis of synthetic organic pigments by various ionization methods. We highlight a recent study of textile samples by atmospheric pressure solid analysis probe MS. Furthermore, the mass spectral features of synthetic organic pigments and their separation from other components such as paint media and plasticizers are discussed.

  13. Making synthetic mudstone: Parametric resedimentation studies at high effective stress to determine controls on breakthrough pressure and permeability

    Science.gov (United States)

    Guiltinan, E. J.; Cardenas, M. B.; Cockrell, L.; Espinoza, N.

    2017-12-01

    The geologic sequestration of CO2 is widely considered a potential solution for decreasing anthropogenic atmospheric CO2 emissions. As CO2 rises buoyantly within a reservoir it pools beneath a caprock and a pressure is exerted upon the pores of the caprock proportionally to the height of the pool. The breakthrough pressure is the point at which CO2 begins to flow freely across the caprock. Understanding the mineralogical and grain size controls on breakthrough pressure is important for screening the security of CO2 sequestration sites. However, breakthrough pressure and permeability measurements on caprocks are difficult to conduct in a systematic manner given the variability in and heterogeneity of naturally occurring mudstones and shales causing significant noise and scatter in the literature. Recent work has even revealed the ability for CO2 to pass through thin shale beds at relatively low pressures. To broaden the understanding of shale breakthrough and permeability, we developed an approach that allows for the creation of resedimented mudstones at high effective stresses. Resedimented samples also include calcium carbonate cement. Using this technique, we explore the controls on entry pressure, breakthrough pressure, and permeability of synthetic mudstones. Understanding the effect of mineralogy and grain size on the permeability and breakthrough pressure of mudstones at reservoir stresses will help in the selection and uncertainty quantification of secure CO2 storage sites.

  14. RUNOFF HYDROGRAPHS USING SNYDER AND SCS SYNTHETIC UNIT HYDROGRAPH METHODS: A CASE STUDY OF SELECTED RIVERS IN SOUTH WEST NIGERIA

    Directory of Open Access Journals (Sweden)

    Wahab Adebayo Salami

    2017-01-01

    Full Text Available This paper presents the development of runoff hydrographs for selected rivers in Ogun-Osun river catchment, south west, Nigeria using Snyder and Soil Conservation Service (SCS methods of synthetic unit hydrograph to determine the ordinates. The Soil Conservation Service (SCS curve Number method was used to estimate the excess rainfall from storm of different return periods. The peak runoff hydrographs were determined by convoluting the unit hydrographs ordinates with the excess rainfall and the value of peak flows obtained by both Snyder and SCS methods observed to vary from one river watershed to the other. The peak runoff hydrograph flows obtained based on the unit hydrograph ordinate determined with Snyder method for 20-yr, 50-yr, 100-yr, 200-yr and 500-yr, return period varied from 112.63m3/s and 13364.30m3/s, while those based on the SCS method varied from 304.43m3/s and 6466.84m3/s for the eight watersheds. However, the percentage difference shows that for values of peak flows obtained with Snyder and SCS methods varies from 13.14% to 63.30%. However, SCS method is recommended to estimate the ordinate required for the development of peak runoff hydrograph in the river watersheds because it utilized additional morphometric parameters such as watershed slope and the curve number (CN which is a function of the properties of the soil and vegetation cover of the watershed.

  15. A parameterization study for elastic VTI Full Waveform Inversion of hydrophone components: synthetic and North Sea field data examples

    KAUST Repository

    Guitton, Antoine

    2017-08-15

    Choosing the right parameterization to describe a transversely isotropic medium with a vertical symmetry axis (VTI) allows us to match the scattering potential of these parameters to the available data in a way that avoids potential tradeoff and focus on the parameters to which the data are sensitive. For 2-D elastic full waveform inversion in VTI media of pressure components and for data with a reasonable range of offsets (as with those found in conventional streamer data acquisition systems), assuming that we have a kinematically accurate NMO velocity (vnmo) and anellipticity parameter η (or horizontal velocity, vh) obtained from tomographic methods, a parameterization in terms of horizontal velocity vh, η and ε is preferred to the more conventional parameterization in terms of vh, δ and ε. In the vh, η, ε parameterization and for reasonable scattering angles (<60o), ε acts as a “garbage collector” and absorbs most of the amplitude discrepancies; between modeled and observed data, more so when density ρ and shear-wave velocity vs are not inverted for (a standard practice with streamer data). On the contrary, in the vv, δ, ε parameterization, ε is mostly sensitive to large scattering angles, leaving vv exposed to strong leakages from ρ mainly. There assertions will be demonstrated on the synthetic Marmousi II as well as a North Sea OBC dataset, where inverting for the horizontal velocity rather than the vertical velocity yields more accurate models and migrated images.

  16. A parameterization study for elastic VTI Full Waveform Inversion of hydrophone components: synthetic and North Sea field data examples

    KAUST Repository

    Guitton, Antoine; Alkhalifah, Tariq Ali

    2017-01-01

    Choosing the right parameterization to describe a transversely isotropic medium with a vertical symmetry axis (VTI) allows us to match the scattering potential of these parameters to the available data in a way that avoids potential tradeoff and focus on the parameters to which the data are sensitive. For 2-D elastic full waveform inversion in VTI media of pressure components and for data with a reasonable range of offsets (as with those found in conventional streamer data acquisition systems), assuming that we have a kinematically accurate NMO velocity (vnmo) and anellipticity parameter η (or horizontal velocity, vh) obtained from tomographic methods, a parameterization in terms of horizontal velocity vh, η and ε is preferred to the more conventional parameterization in terms of vh, δ and ε. In the vh, η, ε parameterization and for reasonable scattering angles (<60o), ε acts as a “garbage collector” and absorbs most of the amplitude discrepancies; between modeled and observed data, more so when density ρ and shear-wave velocity vs are not inverted for (a standard practice with streamer data). On the contrary, in the vv, δ, ε parameterization, ε is mostly sensitive to large scattering angles, leaving vv exposed to strong leakages from ρ mainly. There assertions will be demonstrated on the synthetic Marmousi II as well as a North Sea OBC dataset, where inverting for the horizontal velocity rather than the vertical velocity yields more accurate models and migrated images.

  17. [The primary stability between manual and robot assisted implantation of hip prostheses: A biomechanical study on synthetic femurs].

    Science.gov (United States)

    Decking, J; Gerber, A; Kränzlein, J; Meurer, A; Böhm, B; Plitz, W

    2004-01-01

    We investigated the initial stability of cementless stems implanted with robotic milling and conventional manual broaching. Proximally porous structured stems (G2, ESKA-Implants, Luebeck, Germany) were implanted into synthetic femora. In one group, the femoral cavity was prepared by a CT-based robot (CASPAR, URS-Ortho, Germany) with a high-speed milling head. In the other group, femora were rasped manually with broaches. The broaches had 1 mm proximal press-fit, the robotic cavities 1.5 mm. The implants were exposed to 15 000 loading cycles with 1 000 +/- 500 N. The direction of forces on the implant head were chosen to simulate stair climbing. Internal rotation and translation (caudal, dorsal and lateral) of the implants were measured by linear transducers. The robotic group showed significantly less reversible motion regarding translation in caudal, dorsal and lateral directions. The standard deviations of implant motions were smaller in the robotic group. Using robotic preparation of the femur, initial stability was higher and more consistent than with manual broaching, but differences in undersizing of the cavities created in the femur in relation to the implant may have contributed to these differences for the most part. In-vitro-loading experiments focusing on femoral cavities with varying press-fits are recommended before the introduction of new implants or operating procedures.

  18. Adsorption Studies of Lead by Enteromorpha Algae and Its Silicates Bonded Material

    Directory of Open Access Journals (Sweden)

    Hassan H. Hammud

    2014-01-01

    Full Text Available Lead adsorption by green Enteromorpha algae was studied. Adsorption capacity was 83.8 mg/g at pH 3.0 with algae (E and 1433.5 mg/g for silicates modified algae (EM. FTIR and thermal analysis of algae materials were studied. Thomas and Yoon-Nelson column model were best for adsorbent (E and algae after reflux (ER and Yan model for (EM with capacity 76.2, 71.1, and 982.5 mg/g, respectively. (ER and (EM show less swelling and better flow rate control than (E. Nonlinear methods are more appropriate technique. Error function calculations proved valuable for predicting the best adsorption isotherms, kinetics, and column models.

  19. Intercomparison study of inductively coupled plasma mass spectrometry, thermal ionization mass spectrometry and fission track analysis of μBq quantities of 239Pu in synthetic urine

    International Nuclear Information System (INIS)

    Inn, K.G.W.; McCurdy, D.; Kuruvilla, L.; Barss, N.M.; Bell III, R.T.; Pietrzak, R.; Kaplan, E.; Inkret, W.; Efurd, W.; Rokop, D.; Lewis, D.; Gautier, P.

    2001-01-01

    Even today, some Marshall Islanders are looking forward to permanently resettling their islands after five decades. The U.S. Department of Energy and the resettled residents require reasonable but cost-prudent assurance that the doses to resident from residual 239 Pu will not exceed recognized international standards or recommendations, as estimated from the excretion of 239 Pu in urine. The goal of this study was to evaluate the bias, uncertainty and sensitivity of analytical techniques that measure 3-56 μBq 239 Pu in synthetic urine. The analytical techniques studied in this work included inductively coupled plasma mass spectrometry, thermal ionization mass spectrometry and fission track analysis. The results of the intercomparison demonstrated that all three techniques were capable of marking the measurements, although not with equal degree of bias and uncertainty. The estimated minimum detectable activity was 1 μBq of 239 Pu per synthetic urine sample. This exercise is also the first effort to certify test materials of plutonium in the nBqxg -1 range. (author)

  20. Feasibility study on commercialization of fast breeder reactor cycle system. Interim report of phase 2. Technical study report on synthetic evaluation for FBR cycle

    International Nuclear Information System (INIS)

    Shiotani, Hiroki; Ohtaki, Akira; Ono, Kiyoshi; Yasumatsu, Naoto; Kubota, Sadae; Heta, Masanori

    2004-09-01

    This report presents the outline of the development and the results of Synthetic evaluation on the candidate Fast Reactor (FR) cycle system concepts, scenario study on FR cycle deployment and cost-benefit analysis on the candidate FR cycle system concepts in the interim evaluation (FY2001 through FY2003) of the phase 2 of the Japanese 'Feasibility Study on Commercialization of Fast Reactor Cycle System (FS)'. The characteristic evaluation extended to evaluate a new view point of social acceptance besides the viewpoints of safety, economics, reduction of environmental burden, efficient utilization of uranium resource, proliferation resistance, and technical feasibility, which has been considered since the phase 1 of FS. As for the six view points, hierarchy structures and utility functions for quantitative evaluation have been developed and/or improved. Furthermore, the methodology for weighing the viewpoints, which was also developed, made it possible to examine the characteristics of the candidate concepts from all the seven viewpoints. Generally, the FR cycles with sodium-cooled FR were highly evaluated. The characteristic evaluation for alternative power supply systems was also tried in this report for the first time. FR cycle deployment scenarios clarified the necessity of FR cycle deployment and the desirable core features, etc. through the long-term mass flow analysis, which includes comparison among other nuclear fuel cycle schemes and analysis for evaluating the degree to meet future needs, on the typical FR cycle systems. Regarding cost-benefit analysis, both the amount of the cost estimated by the past R and D and the cost in the Road map of FS are used as the investment for FR cycle research and development (R and D), the results showed that the benefit derived from the commercialization of FR cycle will be more than the investment. (author)

  1. Study by lead isotope method of a vein : Sobrado of the Boquira mine (Bahia State, Brazil)

    International Nuclear Information System (INIS)

    Cassedanne, J.P.; Duthou, J.-L.; Clermont-Ferrand Univ., 63

    1981-01-01

    Fourteen samples of galena from the Sobrado vein, Boquira mine (Bahia) are analysed. Lead isotope compositions show an irregular variation from the central part to the extremidades. They are the result of a mixture of lead from normal galenas and lead which aparent U/Pb ratio are higher. (ARHC) [pt

  2. Who Leads China's Leading Universities?

    Science.gov (United States)

    Huang, Futao

    2017-01-01

    This study attempts to identify the major characteristics of two different groups of institutional leaders in China's leading universities. The study begins with a review of relevant literature and theory. Then, there is a brief introduction to the selection of party secretaries, deputy secretaries, presidents and vice presidents in leading…

  3. Study on the properties of leading protons and antiprotons from exclusive anti pp reactions at 32 GeV/c

    International Nuclear Information System (INIS)

    Bogolyubskij, M.Yu.; Borovikov, A.A.; Boos, Eh.G.

    1986-01-01

    The leading properties of protons and antiprotons from the nondiffractive events are studied for p-barp-exclusive reactions at 32 GeV/c. It is found that the relative leading effect of protons and antiprotons does not depend on the final-state multiplicity and that the longitudinal moments of the leading hadrons are uncorrelated, but a significant part of the transverse momentum of a leading hadron is compensated by the transverse momentum of another leading hadron. It is shown that these experimental facts are described well by a statistical jet-independent model but contradict the Lund string-fragmentation model

  4. A study of the use of lead fluoride for electromagnetic calorimetry

    International Nuclear Information System (INIS)

    Woody, C.L.; Kierstead, J.A.; Levy, P.W.; Stoll, S.; Weingarten, A.B.; Anderson, D.F.; Ramberg, E.J.; Kuno, Y.; Macdonald, J.A.; Konaka, A.; Hutcheon, D.A.

    1992-01-01

    A study has been made on the properties of lead fluoride as a Cherenkov material for use in electromagnetic calorimetry. A prototype calorimeter module consisting of a 5 x 5 array of 2.1 x 2.1 x 18.5 cm 3 crystals has been built and tested in a test beam at the Brookhaven AGS. Results are given on energy resolution, shower size and e/π separation for electrons and pions in the range from 1--4 GeV. The light output has been measured to give approx-gt 1000 photoelectrons per MeV in good quality crystals, and to provide useful signals down to as low as 32 MeV. Measurements were also made on radiation damage in lead fluoride using 60 Co gamma rays and high energy ionizing particles, as well as on thermoluminescence after irradiation. It was found that only modest damage occurs up to a level of ∼ 30 Krad in large, calorimeter size crystals, and that the damage can be easily removed by optical bleaching

  5. Soil microbial respiration and PICT responses to an industrial and historic lead pollution: a field study.

    Science.gov (United States)

    Bérard, Annette; Capowiez, Line; Mombo, Stéphane; Schreck, Eva; Dumat, Camille; Deola, Frédéric; Capowiez, Yvan

    2016-03-01

    We performed a field investigation to study the long-term impacts of Pb soil contamination on soil microbial communities and their catabolic structure in the context of an industrial site consisting of a plot of land surrounding a secondary lead smelter. Microbial biomass, catabolic profiles, and ecotoxicological responses (PICT) were monitored on soils sampled at selected locations along 110-m transects established on the site. We confirmed the high toxicity of Pb on respirations and microbial and fungal biomasses by measuring positive correlations with distance from the wall factory and negative correlation with total Pb concentrations. Pb contamination also induced changes in microbial and fungal catabolic structure (from carbohydrates to amino acids through carboxylic malic acid). Moreover, PICT measurement allowed to establish causal linkages between lead and its effect on biological communities taking into account the contamination history of the ecosystem at community level. The positive correlation between qCO2 (based on respiration and substrate use) and PICT suggested that the Pb stress-induced acquisition of tolerance came at a greater energy cost for microbial communities in order to cope with the toxicity of the metal. In this industrial context of long-term polymetallic contamination dominated by Pb in a field experiment, we confirmed impacts of this metal on soil functioning through microbial communities, as previously observed for earthworm communities.

  6. Feasibility Study On Using Crystalline Lead As a Neutron and Gamma Ray Filter

    International Nuclear Information System (INIS)

    Adib, M.; Naguib, K.; Ashry, A.; Fathalla, M.

    2000-01-01

    A generalized formula is given which allows to calculate the contribution of the total neutron cross- section including the Bragg scattering from different (hkI) planes to the neutron transmission through a solid crystalline material. The formula takes into account the crystalline form of the material (poly- or mono- crystal ) and crystal parameters. A computer program ISCANF-II was developed to provide the required calculations. The calculated values of the neutron transmission through a lead single crystal cut along the (311) plane were compared with the previously measured ones in the wavelength range 0.03-0.52 nm. The measured and calculated values were found to be in reasonable agreement within the statistical accuracy. The feasibility study on using a poly crystalline lead as a cold neutron filter and monocrystalline as a thermal neutron one is given. The optimum crystal thickness, temperature and characteristics for efficiently transmitting the thermal reactor neutrons, while removing simultaneously fast neutrons and gamma rays accompanying the thermal ones for the both cases are given

  7. What motivates occasional faculty developers to lead faculty development workshops? A qualitative study.

    Science.gov (United States)

    O'Sullivan, Patricia S; Irby, David M

    2015-11-01

    The demand for faculty development is ongoing, and many medical schools will need to expand their pool of faculty developers to include physicians and scientists whose primary expertise is not education. Insight into what motivates occasional faculty developers can guide recruitment and retention strategies. This study was designed to understand the motivations of faculty developers who occasionally (one to three times each year) lead faculty development workshops. Qualitative data were collected in March and April 2012 from interviews with faculty developers who occasionally taught workshops from 2007 to 2012 in the University of California, San Francisco, School of Medicine's faculty development program. The interviews were audiotaped and transcribed. The authors thematically analyzed the transcripts using a general inductive approach and developed codes sensitized by motivation theories. The authors interviewed 29/30 (97%) occasional faculty developers and identified five themes: mastery (desire to learn and develop professionally), relatedness (enjoyment of working with and learning from others), duty (sense of obligation to give back and be a good academic citizen), purpose (commitment to improving local teaching and ultimately patient care), and satisfaction (fun and enjoyment). Four of the themes the authors found are well addressed in motivation theory literature: mastery, relatedness, duty, and purpose. Whereas these four are motivators for occasional faculty developers, it is the fifth theme-satisfaction-that the authors feel is foundational and links the others together. Armed with this understanding, individuals leading faculty development programs can develop strategies to recruit and retain occasional faculty developers.

  8. Quantifying lead-time bias in risk factor studies of cancer through simulation.

    Science.gov (United States)

    Jansen, Rick J; Alexander, Bruce H; Anderson, Kristin E; Church, Timothy R

    2013-11-01

    Lead-time is inherent in early detection and creates bias in observational studies of screening efficacy, but its potential to bias effect estimates in risk factor studies is not always recognized. We describe a form of this bias that conventional analyses cannot address and develop a model to quantify it. Surveillance Epidemiology and End Results (SEER) data form the basis for estimates of age-specific preclinical incidence, and log-normal distributions describe the preclinical duration distribution. Simulations assume a joint null hypothesis of no effect of either the risk factor or screening on the preclinical incidence of cancer, and then quantify the bias as the risk-factor odds ratio (OR) from this null study. This bias can be used as a factor to adjust observed OR in the actual study. For this particular study design, as average preclinical duration increased, the bias in the total-physical activity OR monotonically increased from 1% to 22% above the null, but the smoking OR monotonically decreased from 1% above the null to 5% below the null. The finding of nontrivial bias in fixed risk-factor effect estimates demonstrates the importance of quantitatively evaluating it in susceptible studies. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Studies in the determination of lead isotope ratios by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Date, A.R.; Yuk Ying Cheung

    1987-01-01

    The application of ICP-MS to the determination of lead isotope ratios in geological materials is described. Data presented for a series of lead mineral concentrates are compared with reference values obtained by conventional solid source thermal ionisation mass spectrometry. The simultaneous determination of lead isotope ratios and trace elements is carried out in a rapid analysis mode. The application of an electrothermal vaporisation technique for small solution aliquots is described. Lead isotope ratio data for the United States Geological Survey standard reference silicate rock BCR-1, obtained without separation of lead from the matrix, are compared with previously published values obtained after separation. (author)

  10. Removal of lead(II) by adsorption using treated granular activated carbon: batch and column studies.

    Science.gov (United States)

    Goel, Jyotsna; Kadirvelu, Krishna; Rajagopal, Chitra; Kumar Garg, Vinod

    2005-10-17

    In the present study, a deeper understanding of adsorption behavior of Pb(II) from aqueous systems onto activated carbon and treated activated carbon has been attempted via static and column mode studies under various conditions. It probes mainly two adsorbents that is, activated carbon (AC) and modified activated carbon (AC-S). Characterization of both the adsorbents was one of the key focal areas of the present study. This has shown a clear change or demarcation in the various physical and chemical properties of the modified adsorbent from its precursor activated carbon. Both the adsorbents are subjected to static mode adsorption studies and then after a comparison based on isotherm analysis; more efficient adsorbent is screened for column mode adsorption studies. The lead removal increased for sample of treated carbon. The extent of Pb(II) removal was found to be higher in the treated activated carbon. The aim of carrying out the continuous-flow studies was to assess the effect of various process variables, viz., of bed height, hydraulic loading rate and initial feed concentration on breakthrough time and adsorption capacity. This has helped in ascertaining the practical applicability of the adsorbent. Breakthrough curves were plotted for the adsorption of lead on the adsorbent using continuous-flow column operation by varying different operating parameters like hydraulic loading rate (3.0-10.5 m3/(hm2)), bed height (0.3-0.5 m) and feed concentrations (2.0-6.0 mg/l). At the end, an attempt has also been made to model the data generated from column studies using the empirical relationship based on Bohart-Adams model. This model has provided an objective framework to the subjective interpretation of the adsorption system and the model constant obtained here can be used to achieve the ultimate objective of our study that is, up scaling and designing of adsorption process at the pilot plant scale level. AC-S column regeneration using 0.5 and 1.0M concentration of

  11. Biomechanical study: resistance comparison of posterior antiglide plate and lateral plate on synthetic bone models simulating Danis-Weber B malleolar fractures

    Directory of Open Access Journals (Sweden)

    Bruna Buscharino

    2013-06-01

    Full Text Available OBJECTIVE : The purpose of this study was to compare different positions of plates in lateral malleolar Danis-Weber B fractures on synthetic bone: a lateral plate and a posterior antiglide plate. METHODS : Short oblique fractures of distal fibula at the level of the syndesmosys were simulated with a fibular osteotomy in sixteen synthetic fibula bones (Synbone®. Eight fractures were fixed with lateral plating associated with an independent lag screw, and the other eight were fixed with posterior antiglide plating with a lag screw through the plate. A strain gage was installed at the center of each plate at the osteotomy site. Supination and external rotation forces were applied to each of the two groups at the bend. RESULTS : The lateral position plate group suffered more deformity in response to supination forces compared to the group with the posterior antiglide plate, but this result was not statistically significant. In the tests with external rotation forces, the posterior antiglide plating group had significantly higher resistance (p < 0.05. CONCLUSION : When subjected to external rotation forces, osteosynthesis with posterior antiglide plate models simulating type B fractures of the lateral malleolus of the ankle is more resistant than that of the neutralization plate.

  12. Studies on cluster decay from trans-lead nuclei using different versions of nuclear potentials

    Energy Technology Data Exchange (ETDEWEB)

    Santhosh, K.P.; Sukumaran, Indu [Kannur University, School of Pure and Applied Physics, Payyanur, Kerala (India)

    2017-06-15

    The cluster decays from various isotopes of trans-lead nuclei have been studied using 12 different nuclear potentials by evaluating decay half-lives and are then compared with the available experimental data. The study has shown that the barrier penetrability as well as the decay half-lives varies with the nuclear potential used. The standard deviation of the estimated half-lives is also calculated for these twelve nuclear potentials in comparison with the experimental data. The potential Bass 1980 is found to be the most appropriate potential for studying cluster radioactivity as the standard deviation obtained is least. Among the different proximity potential versions; proximity 1977, proximity 1988, proximity 2000, and modified proximity 2000, the minimum standard deviation is for proximity 1988. The Geiger-Nuttall (G-N) plots studied for different cluster emissions from various parents are observed to show linear behavior but with different slopes and intercepts. Again, the G-N plots obtained are linear with different slopes and intercepts when plotted for different nuclear potentials. So it is observed that with the inclusion of different nuclear potentials, the linearity of the G-N plot remains unaltered. Irrespective of the nuclear potential used, the universal curve (log{sub 10}T{sub 1/2} vs. -ln P) studied for various clusters emitted from various parents are obtained as linear with same slope and intercept. (orig.)

  13. The IUGA/ICS classification of synthetic mesh complications in female pelvic floor reconstructive surgery: a multicenter study.

    Science.gov (United States)

    Miklos, John R; Chinthakanan, Orawee; Moore, Robert D; Mitchell, Gretchen K; Favors, Sheena; Karp, Deborah R; Northington, Gina M; Nogueiras, Gladys M; Davila, G Willy

    2016-06-01

    The objective was to report patterns of sling and transvaginal mesh-related complications using the IUGA/ICS classification of prosthesis-related complications. This was a retrospective chart review of all patients who underwent surgical removal of sling, transvaginal mesh, and sacrocolpopexy for mesh-related complications from 2011 to 2013 at three tertiary referral centers. The International Urogynecological Association (IUGA)/International Continence Society (ICS) classification system was utilized. We identified 445 patients with mesh complications, 506 pieces of synthetic mesh were removed, and 587 prostheses-related complications were classified. 3.7 % of patients had viscus organ penetration or vaginal exposure as their presenting chief complaint and 59.7 % were classified as not having any vaginal epithelial separation or category 1. The most common category was spontaneous pain (1Be: 32.5 %) followed by dyspareunia (1Bc: 14.7 %). The sling group was 20 % more likely to have pain compared with the pelvic organ prolapse (POP) mesh group (OR 1.2, 95 % CI 0.8-1.6). The most commonly affected site (S2) was away from the suture line (49 %). Compared with the sling group, the POP group had a higher rate of mesh exposure, which mostly occurred at the suture line area. The majority of patients presented with mesh-related complications more than 1 year post-insertion (T4; average 3.68 ± 2.47 years). Surgeons should be aware that patients with vaginal mesh complications routinely exhibit complications more than 1 year after the implantation with pain as the most common presenting symptom.

  14. STUDY OF INTERACTION BETWEEN LEAD AND GASTRIC MUCOSAL PROTEIN OF RATS WITH FORENSIC TOXICOLOGY APPROACH

    Directory of Open Access Journals (Sweden)

    Iwan Aflanie

    2017-09-01

    Full Text Available Abstract: Recently, forensic toxicology has been an interesting concern, especially in exposing the phenomena associated with the law. Using the forensic toxicology approach, several cases of lead (Pb poisoning have been widely revealed. In this present study will be investigate the interaction between Pb and amino acid gastric mucosal constituent proteins, especially cysteine and tyrosine groups. This research is a pure experimental research with posttest control group design, which is divided into 4 groups with 6 rats (Rattus novergicus in each group. Treatment in each group as follows; P0 was control group were given 2 ml of distilled water; P1 = administration of Pb 0.1 g/L; P2 = Pb administration of 1 mg/L; and P3 = Pb administration of 10 g/L for 4 weeks repectively. According to the results, it can be concluded that Pb-Protein interaction tends to binding of Pb-Cysteine rather than Pb-Tyrosine

  15. Synthesis and Structural Studies of Er3+ Containing Lead Cadmium Fluoroborate Glasses and Glass-Ceramics

    Directory of Open Access Journals (Sweden)

    Silva Maurício A.P.

    2002-01-01

    Full Text Available The vitreous domain was established in the PbF2-CdF2-B2O 3 system from melting and quenching experiments. Er3+ containing glasses were prepared and glass ceramics were obtained by selected heat-treatments. Lead fluoride was identified (beta-PbF2 as the crystalline phase. Structural studies were performed in some glassy and partially crystallized samples by means of X-ray Diffraction (XRD and Extended X-ray Absorption Fine Structure (EXAFS measurements. The role of Cd2+ and Pb2+ atoms on the glass network formation and also on the crystallization behavior was put forward by these techniques. After crystallization Er3+ atoms segregated in the crystal phase.

  16. Experimental Study of the Lead Tungstate Scintillator Proton-Induced Damage and Recovery

    CERN Document Server

    Auffray, Etiennette; Singovski , A

    2011-01-01

    Lead tungstate (PbWO4, or PWO) scintillating crystals are used by two of the four experiments at the Large Hadron Collider (LHC): 75848 in CMS and 17920 in ALICE. For the CMS electromagnetic calorimeter, one of the most important crystal properties is its radiation hardness. With the increase of luminosity, the radiation level will increase drastically, particularly in the high pseudorapidity regions of the calorimeter. Beside the effects of color-centre formation caused by gamma-radiation, additional measurable effect originated by hadron irradiation could appear, which will further deteriorate the optical transmission of the crystals and therefore their efficiency. In this paper, we will present results of the proton-induced damage in PWO and a study of optical transmission recovery at different temperatures and under different light-induced "bleaching" conditions for proton-irradiated crystals.

  17. Performance study of the wearable one-lead wireless electrocardiographic monitoring system.

    Science.gov (United States)

    Hong, Sungyoup; Yang, Yougmo; Kim, Seunghwan; Shin, Seungcheol; Lee, Inbum; Jang, Yongwon; Kim, Kiseong; Yi, Hwayeon

    2009-03-01

    This study attempts to compare and assess the performance of a wearable electrocardiogram (ECG) using a sensing fabric electrode and a Bluetooth network with a conventional ECG. A one-lead ECG examination was performed using Bioshirt and an iWorx 214 while walking or running at 3, 6, and 9 km per hour. A correlation coefficient of a heart rate variability (HRV) between these two devices was higher than 0.96 and power spectral density of HRV measured also showed an excellent agreement. Thus, both of these two ECG devices showed similar detection capability for R peaks. The measured values for wave duration and intervals of both devices concur with each other. The intensity of noise is controversial. The ECG device using a sensing fabric electrode and a wireless network showed an ECG signal detection and transmission capability similar to that of a conventional ECG device.

  18. Study of beauty quark production and next-to-leading order at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Nuncio Quiroz, Adriana Elizabeth

    2008-08-15

    In this thesis a study on the production and evolution of beauty quarks in ep collisions at HERA is presented. The emphasis is put on the corresponding Quantum Chromodynamics predictions including next-to-leading order corrections. In the context of this work the FMNR x Pythia interface was developed, which calculates next-to-leading order Quantum Chromodynamics predictions at visible level for heavy-flavour processes in the photoproduction regime. This is achieved using the RedStat routines which transform the FMNR program into a Monte Carlo-like event generator. The parton-level events obtained are interfaced to Pythia using the Le Houches accord routines. All branching ratios and decay channels of the heavy quarks implemented in the Pythia framework are used, and therefore complex cuts on the nal state can be applied. The FMNR x Pythia interface is applied in this thesis to obtain next-to-leading order predictions for the recently finished heavy flavour ZEUS analyses: the ep {yields} b anti bX {yields} D{sup *}{mu}X' and ep {yields} b anti bX {yields} {mu}{sup +}{mu}{sup -}X' channels. A comparison with the H1 D{sup *}{mu} measurement is also performed. Since the use of such double tagging techniques to identify events where heavy flavours are present proved to be very convenient when the nal state is a pair of leptons, another part of this thesis work deals with the implementation of an electron finder, the {sup G}Elec finder. This finder is tested on the reconstruction of the J/{psi} {yields} e{sup +}e{sup -} signal. Finally, a heavy-flavour analysis has been started, namely the ep {yields} b anti bX {yields} e{mu}X' dilepton channel, using an integrated luminosity of 114 pb{sup -1} gated by the ZEUS detector in the years 1996-2000. Compared to previous analyses the study of beauty quark production in this channel extends the phase space of the measurement closer to the kinematic threshold, since electrons provide access to lower p{sub T} values

  19. Study of beauty quark production and next-to-leading order effects at HERA

    International Nuclear Information System (INIS)

    Nuncio Quiroz, Adriana Elizabeth

    2008-08-01

    In this thesis a study on the production and evolution of beauty quarks in ep collisions at HERA is presented. The emphasis is put on the corresponding Quantum Chromodynamics predictions including next-to-leading order corrections. In the context of this work the FMNR x Pythia interface was developed, which calculates next-to-leading order Quantum Chromodynamics predictions at visible level for heavy-flavour processes in the photoproduction regime. This is achieved using the RedStat routines which transform the FMNR program into a Monte Carlo-like event generator. The parton-level events obtained are interfaced to Pythia using the Le Houches accord routines. All branching ratios and decay channels of the heavy quarks implemented in the Pythia framework are used, and therefore complex cuts on the nal state can be applied. The FMNR x Pythia interface is applied in this thesis to obtain next-to-leading order predictions for the recently finished heavy flavour ZEUS analyses: the ep → b anti bX → D * μX' and ep → b anti bX → μ + μ - X' channels. A comparison with the H1 D * μ measurement is also performed. Since the use of such double tagging techniques to identify events where heavy flavours are present proved to be very convenient when the nal state is a pair of leptons, another part of this thesis work deals with the implementation of an electron finder, the G Elec finder. This finder is tested on the reconstruction of the J/ψ → e + e - signal. Finally, a heavy-flavour analysis has been started, namely the ep → b anti bX → eμX' dilepton channel, using an integrated luminosity of 114 pb -1 gated by the ZEUS detector in the years 1996-2000. Compared to previous analyses the study of beauty quark production in this channel extends the phase space of the measurement closer to the kinematic threshold, since electrons provide access to lower p T values than muons do. The technical part of this thesis consisted in the calibration, maintenance and data

  20. Sources of dissolved mine drainage and atmospheric transported lead: A comparative case study in Japan and Sweden

    International Nuclear Information System (INIS)

    Aberg, Goeran; Satake, Kenichi

    2009-01-01

    A comparative case study in Naganobori Japan and Falun Sweden of runoff water from copper mines shows that the water and its particulates, filtered with a cutoff of 0.45 μm, have different lead isotope ratios pointing to different origins for the lead. While the larger particles have a lead ratio indicative of the atmospheric anthropogenic pollution the soluble lead has that of the copper ores. The domestic atmospheric lead ratio in Japan is homogeneous and characteristic of emissions from the incineration of waste. Lead pollution transported from the Asian continent by westerly winds can be distinguished from the Japanese pollution by its more thorogenic lead ratios, in for example analyses of copper moss from Naganobori.

  1. Comparative study for "36 V" vehicle applications: advantages of lead-acid batteries

    Science.gov (United States)

    Lailler, Patrick; Sarrau, Jean-François; Sarrazin, Christian

    From thermal engine equipped vehicles to completely electric ones, evolution of light weight vehicles in the future will take several steps in so far as there is no adequate battery or fuel cell presently available to power these vehicles for "on the road" driving. On the other hand, for city driving, vehicles can be improved a lot in terms of fuel efficiency as well as air pollution, if partly or totally electric propulsion can be developed, manufactured and marketed for appropriate applications. The 36-42 V battery is part of this orientation towards improving the efficiency of thermal vehicles in city driving, while keeping adequate autonomy on the roads. Actually, in city traffic, thermal engines are idle most of the time and stop periods represent a large part of the time spent "driving", using up fuel and polluting air for no use at all. The idea of stopping the engine during these periods, if appropriately managed, might potentially lead to a large improvement in fuel economy as well as air pollution reduction. The association of a higher voltage battery to an alternator-starter device in thermal vehicles, seems to be an interesting way towards that end. In this paper, we are presenting our results of a study we have just completed in relationship with RENAULT & VALEO, supported by the French Ministry of Industry, concerning a comparative evaluation of different automobile energy storage systems, and the definition of specifications as the final step of this study. The main conclusion is that lead-acid will still remain dominant in this role, since its operational cost versus efficiency is by far the lowest of every battery presently considered, more particularly in the less expensive car segments.

  2. Covellite CuS as a matrix for "invisible" gold: X-ray spectroscopic study of the chemical state of Cu and Au in synthetic minerals

    Science.gov (United States)

    Tagirov, Boris R.; Trigub, Alexander L.; Kvashnina, Kristina O.; Shiryaev, Andrey A.; Chareev, Dmitriy A.; Nickolsky, Maximilian S.; Abramova, Vera D.; Kovalchuk, Elena V.

    2016-10-01

    Geological processes leading to formation of sulfide ores often result in precipitation of gold-bearing sulfides which can contain high concentrations of this metal in ;invisible; (or ;refractory;) state. Covellite (CuS) is ubiquitous mineral in many types of the ore deposits, and numerous studies of the natural ores show that covellite can contain high concentrations of Au. At the same time, Au-bearing covellite withstands cooling in contrast to other minerals of the Cu-Fe-S system (chalcocite, bornite, chalcopyrite), where Au exsolves at low temperatures. This makes covellite a convenient model system for investigation of the chemical state (local environment and valence) of the ;invisible; Au in copper-sulfide ores (copper-porphyry, epithermal, volcanogenic massive sulfide, SEDEX deposits). Therefore, it is necessary to determine the location of Au in the covellite matrix as it will have important implications for the methods employed by mineral processing industry to extract Au from sulfide ores. Here we investigate the chemical state of Cu and Au in synthetic covellite containing up to 0.3 wt.% of Au in the ;invisible; state. The covellite crystals were synthesized by hydrothermal and salt flux methods. Formation of the chemically bound Au is indicated by strong dependence of the concentration of Au in covellite on the sulfur fugacity in the experimental system (d(log C(Au))/d(log f(S2)) ∼ 0.65). The Au concentration of covellite grows with increasing temperature from 400 to 450 °C, whereas further temperature increase to 500 °C has only minor effect. The synthesized minerals were studied using X-ray absorption fine structure spectroscopy (XAFS) in high energy resolution fluorescence detection (HERFD) mode. Ab initio simulations of Cu K edge XANES spectra show that the Cu oxidation state in two structural positions in covellite (tetrahedral and triangular coordination with S atoms) is identical: the total loss of electronic charge for the 3d shell is ∼0

  3. Regional lead isotope study of a polluted river catchment: River Wear, Northern England, UK

    International Nuclear Information System (INIS)

    Shepherd, Thomas J.; Chenery, Simon R.N.; Pashley, Vanessa; Lord, Richard A.; Ander, Louise E.; Breward, Neil; Hobbs, Susan F.; Horstwood, Matthew; Klinck, Benjamin A.; Worrall, Fred

    2009-01-01

    High precision, lead isotope analyses of archived stream sediments from the River Wear catchment, northeast England (1986-88), provide evidence for three main sources of anthropogenic lead pollution; lead mining, industrial lead emissions and leaded petrol. In the upper catchment, pollution is totally controlled and dominated by large lead discharges from historic mining centres in the North Pennine Orefield ( 208 Pb/ 206 Pb, 207 Pb/ 206 Pb ratios range from 2.0744-2.0954 and 0.8413-0.8554 respectively). In the lower catchment, co-extensive with the Durham Coalfield and areas of high population density, pollution levels are lower and regionally more uniform. Isotope ratios are systematically higher than in the upper catchment ( 208 Pb/ 206 Pb, 207 Pb/ 206 Pb ratios range from 2.0856-2.1397 and 0.8554-0.8896 respectively) and far exceed values determined for the geogenic regional background. Here, the pollution is characterised by the atmospheric deposition of industrial lead and petrol lead. Lead derived from the combustion of coal, although present, is masked by the other two sources. Recent sediments from the main channel of the River Wear are isotopically indistinguishable from older, low order stream sediments of the North Pennine Orefield, indicating that contamination of the river by lead mining waste (up to several 1000 mg/kg Pb at some locations) continues to pose an environmental problem; a pattern that can be traced all the way to the tidal reach. Using within-catchment isotope variation and sediment lead concentrations, estimates can be made of the discharges from discrete mines or groups of mines to the overall level of lead pollution in the River Wear. As well as providing information pertinent to source apportionment and on-going catchment remediation measures, the database is a valuable resource for epidemiologists concerned with the health risks posed by environmental lead.

  4. Regional lead isotope study of a polluted river catchment: River Wear, Northern England, UK

    Energy Technology Data Exchange (ETDEWEB)

    Shepherd, Thomas J., E-mail: shepherdtj@aol.com [Department of Earth Sciences, University of Durham, Science Laboratories, Durham DH1 3LE (United Kingdom); Chenery, Simon R.N. [British Geological Survey, Nicker Hill, Keyworth, Nottingham NG12 5GG (United Kingdom); Pashley, Vanessa [NERC Isotope Geosciences Laboratory, Kingsley Dunham Centre, Keyworth, Nottingham NG12 5GG (United Kingdom); Lord, Richard A. [School of Science and Technology, University of Teesside, Middlesbrough, Tees Valley TS1 3BA (United Kingdom); Ander, Louise E.; Breward, Neil; Hobbs, Susan F. [British Geological Survey, Nicker Hill, Keyworth, Nottingham NG12 5GG (United Kingdom); Horstwood, Matthew [NERC Isotope Geosciences Laboratory, Kingsley Dunham Centre, Keyworth, Nottingham NG12 5GG (United Kingdom); Klinck, Benjamin A. [British Geological Survey, Nicker Hill, Keyworth, Nottingham NG12 5GG (United Kingdom); Worrall, Fred [Department of Earth Sciences, University of Durham, Science Laboratories, Durham DH1 3LE (United Kingdom)

    2009-08-15

    High precision, lead isotope analyses of archived stream sediments from the River Wear catchment, northeast England (1986-88), provide evidence for three main sources of anthropogenic lead pollution; lead mining, industrial lead emissions and leaded petrol. In the upper catchment, pollution is totally controlled and dominated by large lead discharges from historic mining centres in the North Pennine Orefield ({sup 208}Pb/{sup 206}Pb, {sup 207}Pb/{sup 206}Pb ratios range from 2.0744-2.0954 and 0.8413-0.8554 respectively). In the lower catchment, co-extensive with the Durham Coalfield and areas of high population density, pollution levels are lower and regionally more uniform. Isotope ratios are systematically higher than in the upper catchment ({sup 208}Pb/{sup 206}Pb, {sup 207}Pb/{sup 206}Pb ratios range from 2.0856-2.1397 and 0.8554-0.8896 respectively) and far exceed values determined for the geogenic regional background. Here, the pollution is characterised by the atmospheric deposition of industrial lead and petrol lead. Lead derived from the combustion of coal, although present, is masked by the other two sources. Recent sediments from the main channel of the River Wear are isotopically indistinguishable from older, low order stream sediments of the North Pennine Orefield, indicating that contamination of the river by lead mining waste (up to several 1000 mg/kg Pb at some locations) continues to pose an environmental problem; a pattern that can be traced all the way to the tidal reach. Using within-catchment isotope variation and sediment lead concentrations, estimates can be made of the discharges from discrete mines or groups of mines to the overall level of lead pollution in the River Wear. As well as providing information pertinent to source apportionment and on-going catchment remediation measures, the database is a valuable resource for epidemiologists concerned with the health risks posed by environmental lead.

  5. CFD study on NACA 4415 airfoil implementing spherical and sinusoidal Tubercle Leading Edge.

    Directory of Open Access Journals (Sweden)

    S M A Aftab

    Full Text Available The Humpback whale tubercles have been studied for more than a decade. Tubercle Leading Edge (TLE effectively reduces the separation bubble size and helps in delaying stall. They are very effective in case of low Reynolds number flows. The current Computational Fluid Dynamics (CFD study is on NACA 4415 airfoil, at a Reynolds number 120,000. Two TLE shapes are tested on NACA 4415 airfoil. The tubercle designs implemented on the airfoil are sinusoidal and spherical. A parametric study is also carried out considering three amplitudes (0.025c, 0.05c and 0.075c, the wavelength (0.25c is fixed. Structured mesh is utilized to generate grid and Transition SST turbulence model is used to capture the flow physics. Results clearly show spherical tubercles outperform sinusoidal tubercles. Furthermore experimental study considering spherical TLE is carried out at Reynolds number 200,000. The experimental results show that spherical TLE improve performance compared to clean airfoil.

  6. Crust growth and gas retention in synthetic Hanford waste

    International Nuclear Information System (INIS)

    Bryan, S.A.; Pederson, L.R.; Scheele, R.D.

    1992-03-01

    The focus of the work described here is to examine the principal contributing factors leading to slurry growth and gas retention within waste from a particular high-level waste tanks on the Hanford Site. Laboratory studies of aged synthetic waste have shown that the waste retains gases in the form of bubble attachment to solid particles. This attachment phenomenon is related to the presence of organic constituents (HEDTA, EDTA, and citrate) added to the waste matrix. The mechanism for bubble attachment is related to the hydrophobic surface produced by the organic complexant. The formation of a stable gas bubble/solid interaction is believed to be responsible for crust flotation and gas retention in the synthetic waste used here

  7. Study on damage of DNA in mice induced by mercury cadmium and/or lead

    International Nuclear Information System (INIS)

    Hu Xiaopan; Zhou Jianhua; Shi Xijing; Yan Liping

    2004-01-01

    Objective: To explore the joint injury actions of mercury, cadmium and/or lead on DNA in peripheral blood lymphocytes of mice. Methods: The blood specimens were obtained from mice at the 2 day after the peritoneal injections. DNA damages were determined by single cell gel electrophoresis (SCGE) and 3 H-TdR incorporation. Results: Acquired by SCGE technique, tail movement of DNA in mercury-cadmium-lead group was significantly greater than that in the single exposure group, the difference was significant too between mercury-cadmium group and cadmium group, cadmium-lead group and cadmium group. The results of 3 H-TdR incorporation showed: the values of DPM in mercury-cadmium group and cadmium-lead group were lower than that in the single exposure group and the value of DPM lowered more significantly after exposure to mercury-cadmium-lead. Conclusion: The combined effects of mercury, cadmium, lead on DNA damage are more significant. (author)

  8. Reasons for Synthetic THC Use among College Students

    Science.gov (United States)

    Vidourek, Rebecca A.; King, Keith A.; Burbage, Michelle L.

    2013-01-01

    Synthetic THC, also known as fake marijuana, is used by college students in the United States. The present study examined reasons for recent synthetic THC use among college students (N = 339). Students completed a 3-page survey during regularly scheduled class times. Results indicated students reported using synthetic THC for curiosity, to get…

  9. Efficacy of bio and synthetic pesticides against the American ...

    African Journals Online (AJOL)

    Management for the bollworm complex in Uganda is largely synthetic chemical use with little or no biopesticide use which reduces natural enemies population and resistance development to continuous use of a single synthetic pesticide product. Therefore this study aimed at determining the efficacy of bio and synthetic ...

  10. Study of calcium-dependent lead-tolerance on plants differing in their level of Ca-deficiency tolerance

    International Nuclear Information System (INIS)

    Antosiewicz, Danuta Maria

    2005-01-01

    The main aim of the study was to determine the role of calcium in the amelioration of lead toxic effects in plants with accordingly high/low level of Pb-tolerance and high/low Ca-deficiency tolerance. The study was performed on maize, rye, tomato and mustard. Plants were cultivated in modified Knop's solution. They were subjected to Ca-deficiency, and to lead nitrate administered in the presence of four calcium nitrate concentrations 3.0, 2.4, 1.2, 0.3 mM. Lead-tolerance and tolerance to Ca-deficiency were determined, as were concentration of the studied elements in plant tissues, and the Pb deposition pattern at the ultrastructural level (electron microscopy study, X-ray microanalysis). In all studied plants, lead toxicity increased as medium calcium content decreased, however, only in the Ca-deficiency sensitive mustard with low Pb-tolerance was it accompanied by a rise in tissue lead concentration. In contrast, lead root and shoot levels did not increase in the highly Ca-deficiency tolerant tomato, mustard and rye with high Pb-tolerance irrespective of the Ca 2+ regimens applied. Thus, in these plants, lead's unfavourable effects resulted only from the higher toxicity of the same amount of lead in tissues at low calcium in the medium. Of particular relevance is the finding by electron microscopy and X-ray microanalysis, that under low calcium in both highly Ca-deficiency tolerant and Ca-deficiency sensitive plants, less efficient Pb 2+ detoxification was accompanied by the restriction of the formation of large lead deposits in cell walls. Obtained results are novel in demonstrating calcium involvement in the lead deposition in the cell wall, thus in the regulation of the internal lead detoxification. - Calcium regulated lead deposition in cell walls of plants

  11. Designer Drugs: A Synthetic Catastrophe

    OpenAIRE

    Fratantonio, James; Andrade, Lawrence; Febo, Marcelo

    2015-01-01

    Synthetic stimulants can cause hallucinations, aggressive behaviors, death and are sometimes legal. These substances are sold as plant food and bath salts that are "Not for Human Consumption", therefore skirting the 1986 Federal Analogue Act and giving a false pretense of safety. Studies have proved that these substances are toxic, have a high abuse potential, and are becoming extremely prevalent in the United States. This creates a dilemma for law enforcement agents, hospitals, and substance...

  12. SU-E-T-531: Large--Scale DVH Quality Study: Correlated Aims Lead Relaxations

    Energy Technology Data Exchange (ETDEWEB)

    Nohadani, O; Roy, A [Northwestern University, Evanston, IL (United States); Das, I [Indiana University- School of Medicine, Indianapolis, IN (United States)

    2015-06-15

    Purpose: Intensity modulated radiation therapy plans are designed to optimally target a tumor while sparing surrounding tissue. Desired dose distributions are iteratively approached via inverse planning. This leads to tradeoffs between clinical objectives for the planning target volume (PTV), organs at risk, and normal tissues. Dose volume histogram (DVHs) related aims are followed that are either institutional or internationally recommended. We analyze common goals and identify potential reasons that often lead to tradeoffs. Methods: 524 IMRT plans for various tumor sites were analyzed based on the main institutional DVH goal for PTV (D95) and the recommendations by ICRU-83 (D2, D50, and D98). Robust statistical tools are developed and applied to ensure that the results are immune to data uncertainties. The probability of violation was measured for each of the DVH goals based on the frequency of not meeting recommended doses. Conditional probabilities for satisfying and/or violating DVH aims were computed to test the hypothesized pair-wise relations between DVH aims. For example, for plans that satisfied D50, the probability of violating D98 was computed via P(D98 < 95% | 98% ≤ D50 ≤ 102%). The equality constraint D50 = 100% was relaxed to encompass the range [98,102]%. Results: A large majority of cases (88%) satisfied the institutional goal for PTV of D95 ≤ 95%. Similar consensus existed for D98. 51% of cases satisfied D2 ≥ 107%. However, only 18% of cases satisfied D50. The conditional probability showed correlations amongst the studied DVH goals. In fact, a negative correlation was revealed between D50 and D95 (and D98), suggesting that these competing goals cannot be satisfied concurrently. Conclusion: The majority of plans followed the institutional guidelines. The reason for their deviation from international recommendations seems to be that the latter goals are competing and cannot be satisfied concurrently in clinical practice.

  13. Nuclear PDF studies with proton-lead measurements with the ALICE detector

    CERN Document Server

    Mischke, André

    2018-01-01

    The proton-lead programme at CERN’s Large Hadron Collider allowed the study of cold-nuclear matter effects from the initial state, such as Cronin enhancement, nuclear shadowing and gluon saturation. They result in a modification of the production cross section and thus provide crucial tests of predictions from perturbative Quantum-Chromodynamics. Furthermore, these control measurements are needed to characterise the extent to which initial-state effects can be differentiated from effects due to final-state interactions in the so-called quark-gluon plasma, produced in high-energy collisions of heavy atomic nuclei. In this contribution, recent results from the ALICE experiment on the measurements of lightflavour production and jets will be presented. Especially, the multi-strange baryon yields allow the study of the canonical suppression in small systems, whereas jets have been studied in term of the acoplanarity between full and charged jets and the nuclear modification factor as a function of collision cent...

  14. Nuclear PDF studies with proton-lead measurements with the ALICE detector

    CERN Document Server

    Mischke, André

    2017-01-01

    The proton-lead programme at CERN’s Large Hadron Collider allowed the study of cold-nuclear matter effects from the initial state, such as Cronin enhancement, nuclear shadowing and gluon saturation. They result in a modification of the production cross section and thus provide crucial tests of predictions from perturbative Quantum-Chromodynamics. Furthermore, these control measurements are needed to characterise the extent to which initial-state effects can be differentiated from effects due to final-state interactions in the so-called quark-gluon plasma, produced in high-energy collisions of heavy atomic nuclei. In this contribution, recent results from the ALICE experiment on the measurements of lightflavour production and jets will be presented. Especially, the multi-strange baryon yields allow the study of the canonical suppression in small systems, whereas jets have been studied in term of the acoplanarity between full and charged jets and the nuclear modification factor as a function of collision cent...

  15. Growing together: a qualitative study of leading nurse scholars in Thailand.

    Science.gov (United States)

    Turale, S; Klunklin, A; Chontawan, R

    2010-06-01

    Asia-Pacific nursing education and research is growing but little is known about the nature and development of nursing scholarship in the region. This qualitative study explored the perspectives of 14 leading Thai scholars about the development, facilitators and barriers relating to Thailand's nursing scholarship. In-depth interviews were digitally recorded, and data were subjected to content analysis. Five themes arose: (1) growing together, (2) visionary leadership, (3) external support to grow nurse scholars, (4) developing nursing through research, and (5) barriers to scholarship. A history of visionary nursing leadership was revealed, underpinned by leaders' values of growing nursing together. Resource sharing among universities, and a significant number of scholarships for study abroad were major facilitators of scholarship growth. Barriers to scholarship included high teaching loads, especially for newly graduated faculty; a low rate of research publications; not enough mentorship for research and changes to teaching practice; and a wide range of different agencies providing courses for entry to practice. Scholarship development in Thailand is a role model for a number of South-East Asian countries, with inclusiveness and collaboration to facilitate the growth of nursing education inside and outside of the country as a hallmark of its character. However, against a backdrop of nursing shortages, Thai scholars are challenged, in the future, to produce meaningful research outcomes, including publications of studies; to collaborate with other health professionals; change practices to overcome high teaching loads; and provide the much needed mentorship for young scholars.

  16. Parametric analyses of summative scores may lead to conflicting inferences when comparing groups: A simulation study.

    Science.gov (United States)

    Khan, Asaduzzaman; Chien, Chi-Wen; Bagraith, Karl S

    2015-04-01

    To investigate whether using a parametric statistic in comparing groups leads to different conclusions when using summative scores from rating scales compared with using their corresponding Rasch-based measures. A Monte Carlo simulation study was designed to examine between-group differences in the change scores derived from summative scores from rating scales, and those derived from their corresponding Rasch-based measures, using 1-way analysis of variance. The degree of inconsistency between the 2 scoring approaches (i.e. summative and Rasch-based) was examined, using varying sample sizes, scale difficulties and person ability conditions. This simulation study revealed scaling artefacts that could arise from using summative scores rather than Rasch-based measures for determining the changes between groups. The group differences in the change scores were statistically significant for summative scores under all test conditions and sample size scenarios. However, none of the group differences in the change scores were significant when using the corresponding Rasch-based measures. This study raises questions about the validity of the inference on group differences of summative score changes in parametric analyses. Moreover, it provides a rationale for the use of Rasch-based measures, which can allow valid parametric analyses of rating scale data.

  17. Zinc and lead transfer in a contaminated roadside soil: Experimental study and modeling

    International Nuclear Information System (INIS)

    Hanna, K.; Lassabatere, L.; Bechet, B.

    2009-01-01

    The application of a surface complexation model to simulate the sorption of metals on single sorbents is very well investigated, but very little is known regarding the use of surface complexation modeling to simulate the metal mobility in contaminated roadside soils. The overall objective of this study was to examine whether the use of the surface complexation model (SCM) could correctly describe the migration of zinc and lead in roadside soil under various physicochemical conditions. The release and transport of Zn and Pb was studied by means of batch reactors and saturated chromatography columns. Soil batch experiments were conducted to evaluate the effects of pH variation and ionic strength on the metal mobility from soil. Elution of Pb and Zn was examined in column experiments by using acetic acid at pH5 and EDTA at pH7. The modeling work has focused on the development of a SCM using MINTEQ2 database incorporated in PHREEQC-2 to describe the interactions between trace metals and the main mineral soil components (quartz, iron and aluminum oxides). In this study, it was found that the SCM was able to simulate the mobility of metals from soil by assuming one mononuclear surface reaction between one solution species (Me 2+ ) and one type of site on the surface of soil dominant sorbents

  18. Clinical trial and in-vitro study comparing the efficacy of treating bony lesions with allografts versus synthetic or highly-processed xenogeneic bone grafts

    DEFF Research Database (Denmark)

    Kubosch, Eva Johanna; Bernstein, Anke; Wolf, Laura

    2016-01-01

    BACKGROUND: Our study aim was to compare allogeneic cancellous bone (ACB) and synthetic or highly-processed xenogeneic bone substitutes (SBS) in the treatment of skeletal defects in orthopedic surgery. METHODS: 232 patients treated for bony lesions with ACB (n = 116) or SBS (n = 116) within a 10......-year time period were included in this case-control study. Furthermore, both materials were seeded with human osteoblasts (hOB, n = 10) and analyzed by histology, for viability (AlamarBlue®) and protein expression activity (Luminex®). RESULTS: The complication rate was 14.2 %, proportion of defects....... Histological examination revealed similar bone structures, whereas cell remnants were apparent only in the allografts. Both materials were biocompatible in-vitro, and seeded with human osteoblasts. The cells remained vital over the 3-week culture period and produced microscopically typical bone matrix. We...

  19. Non-Linear Optical Studies On Sol-Gel Derived Lead Chloride Crystals Using Z-Scan Technique

    OpenAIRE

    Rejeena, I; Lillibai, B; Toms, Roseleena; Nampoori, VP N; Radhakrishnan, P

    2014-01-01

    In this paper we report the preparation, optical characterization and non linear optical behavior of pure lead chloride crystals. Lead chloride samples subjected to UV and IR irradiation and electric and magnetic fields have also been investigated Optical nonlinearity in these lead chloride samples were determined using single beam and high sensitive Z-scan technique. Non linear optical studies of these materials in single distilled water show reverse saturable absorption which makes th...

  20. Comparative study for the removal of Sr2+ and Pb2+ from waste solutions using synthetic and natural cow bone apatite

    International Nuclear Information System (INIS)

    Ezz El-Din, M.R.

    2007-01-01

    The aim of this study is to develop the cow bone derived apatite as a new sorbent for Sr 2+ and Pb 2+ ions from their aqueous waste solutions. In this respect, four different types of apatite (Ca 10 (PO 4 )6(OH) 2 ) were investigated. The first was natural cow bone apatite (raw bone). The second was cow bone derived apatite after treatment at 700 degree C. The third was synthetic apatite and the last was commercial apatite supplied from Bio Rad company, USA. Removal of Sr 2+ and Pb 2+ by the studied samples was investigated using batch experiments. The different parameters affecting sorption process such as contact time, metal ion concentration and hydrogen ion concentration of the aqueous phase were studied. Desorption of the investigated ions from the loaded samples was also studied. The results obtained showed that the raw cow bone was more effective than the other investigated HAP for adsorbing both Sr 2+ and Pb 2+ ions since the removal percentage of Sr 2+ and Pb 2+ by natural cow bone apatite were 85% and 98%, respectively, while the removal of Sr 2+ and Pb 2+ by the synthetic apatite were 71% and 62%, respectively. From the obtained data, it can be concluded that the natural (raw) cow bone apatite can be used as an ion exchanger for removal of some radioactive elements that may present in radioactive waste solutions as well as it could be considered as a new competitor of the other natural absorbents. Therefore, it is recommended that the natural cow bone apatite could be used for removal of both Sr 2+ and Pb 2+ from radioactive waste solutions as well as other wastewater