WorldWideScience

Sample records for synthetic chemicals measurement

  1. Synthetic Biology for Specialty Chemicals.

    Science.gov (United States)

    Markham, Kelly A; Alper, Hal S

    2015-01-01

    In this review, we address recent advances in the field of synthetic biology and describe how those tools have been applied to produce a wide variety of chemicals in microorganisms. Here we classify the expansion of the synthetic biology toolbox into three different categories based on their primary function in strain engineering-for design, for construction, and for optimization. Next, focusing on recent years, we look at how chemicals have been produced using these new synthetic biology tools. Advances in producing fuels are briefly described, followed by a more thorough treatment of commodity chemicals, specialty chemicals, pharmaceuticals, and nutraceuticals. Throughout this review, an emphasis is placed on how synthetic biology tools are applied to strain engineering. Finally, we discuss organism and host strain diversity and provide a future outlook in the field.

  2. Bioinspired Chemical Communication between Synthetic Nanomotors.

    Science.gov (United States)

    Chen, Chuanrui; Chang, Xiaocong; Teymourian, Hazhir; Ramírez-Herrera, Doris E; Esteban-Fernández de Ávila, Berta; Lu, Xiaolong; Li, Jinxing; He, Sha; Fang, Chengcheng; Liang, Yuyan; Mou, Fangzhi; Guan, Jianguo; Wang, Joseph

    2018-01-02

    While chemical communication plays a key role in diverse natural processes, the intelligent chemical communication between synthetic nanomotors remains unexplored. The design and operation of bioinspired synthetic nanomotors is presented. Chemical communication between nanomotors is possible and has an influence on propulsion behavior. A chemical "message" is sent from a moving activator motor to a nearby activated (receiver) motor by release of Ag + ions from a Janus polystyrene/Ni/Au/Ag activator motor to the activated Janus SiO 2 /Pt nanomotor. The transmitted silver signal is translated rapidly into a dramatic speed change associated with the enhanced catalytic activity of activated motors. Selective and successive activation of multiple nanomotors is achieved by sequential localized chemical communications. The concept of establishing chemical communication between different synthetic nanomotors paves the way to intelligent nanoscale robotic systems that are capable of cooperating with each other. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Visualizing Chemical Bonds in Synthetic Molecules

    Science.gov (United States)

    Collins, Laura C.; Ruth, Anthony; Green, David B.; Janko, Boldizsar; Gomes, Kenjiro K.

    The use of synthetic quantum systems makes it possible to study phenomena that cannot be probed by conventional experiments. We created synthetic molecules using atomic manipulation and directly imaged the chemical bonds using tunneling spectroscopy. These synthetic systems allow us to probe the structure and electronic properties of chemical bonds in molecules, including those that would be unstable in nature, with unprecedented detail. The experimental images of electronic states in our synthetic molecules show a remarkable match to the charge distribution predicted by density functional theory calculations. The statistical analysis of the spectroscopy of these molecules can be adapted in the future to quantify aromaticity, which has been difficult to quantify universally thus far due to vague definitions. We can also study anti-aromatic molecules which are unstable naturally, to illuminate the electronic consequences of antiaromaticity.

  4. 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.

  5. Challenges and opportunities in synthetic biology for chemical engineers

    Energy Technology Data Exchange (ETDEWEB)

    Luo, YZ; Lee, JK; Zhao, HM

    2013-11-15

    Synthetic biology provides numerous great opportunities for chemical engineers in the development of new processes for large-scale production of biofuels, value-added chemicals, and protein therapeutics. However, challenges across all scales abound. In particular, the modularization and standardization of the components in a biological system, so-called biological parts, remain the biggest obstacle in synthetic biology. In this perspective, we will discuss the main challenges and opportunities in the rapidly growing synthetic biology field and the important roles that chemical engineers can play in its advancement. (C) 2012 Elsevier Ltd. All rights reserved.

  6. 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...

  7. [Prevalences of allergic diseases among synthetic chemical workers].

    Science.gov (United States)

    Chida, T; Uehata, T

    1987-09-01

    We studied the prevalence of allergic diseases among synthetic chemical workers, using a cross-sectional questionnaire, to clarify the epidemiological evidence of occupational allergy due to chemicals which workers were handling and manufacturing. A file, registered in 1981, of 6,819 person, was used to calculate the prevalence during the preceding 12 months of "allergy," "asthma," and "skin disease," and to analyze the relationship between the prevalence and the exposure risks such as the work or the chemicals being manufactured. The main results were: 1) In workers who were exposed to the various chemicals, the prevalence of "allergy," "asthma," and "skin disease" were 3.2, 1.9, and 9.0%, respectively. 2) Among the workers who were engaged in the manufacturing of synthetic resins, paints, films, titania or pharmaceuticals, the prevalence of "allergy" was significantly higher than among others. The rates of "asthma" were significantly higher than others among workers in cosmetics, synthetic resins, or fertilizers. The rates of "skin disease" were significantly higher among those working with cosmetics, synthetic resins, paints, dyes, or organic solvents. The results indicate that allergy research should be concentrated on workers engaged in manufacturing the above chemicals.

  8. Opportunities for synthetic biology in antibiotics: expanding glycopeptide chemical diversity.

    Science.gov (United States)

    Thaker, Maulik N; Wright, Gerard D

    2015-03-20

    Synthetic biology offers a new path for the exploitation and improvement of natural products to address the growing crisis in antibiotic resistance. All antibiotics in clinical use are facing eventual obsolesce as a result of the evolution and dissemination of resistance mechanisms, yet there are few new drug leads forthcoming from the pharmaceutical sector. Natural products of microbial origin have proven over the past 70 years to be the wellspring of antimicrobial drugs. Harnessing synthetic biology thinking and strategies can provide new molecules and expand chemical diversity of known antibiotic scaffolds to provide much needed new drug leads. The glycopeptide antibiotics offer paradigmatic scaffolds suitable for such an approach. We review these strategies here using the glycopeptides as an example and demonstrate how synthetic biology can expand antibiotic chemical diversity to help address the growing resistance crisis.

  9. Physical and chemical characterization of synthetic calcined sludge

    International Nuclear Information System (INIS)

    Slates, R.V.; Mosley, W.C. Jr.; Tiffany, B.; Stone, J.A.

    1982-03-01

    Calcined synthetic sludge was chemically characterized in support of engineering studies to design a processing plant to solidify highly radioactive waste at the Savannah River Plant. An analytical technique is described which provides quantitative data by mass spectrometric analysis of gases evolved during thermogravimetric analysis without measurements of gas flow rates or mass spectrometer sensitivities. Scanning electron microprobe analysis, Mossbauer spectroscopy, and several other common analytical methods were also used. Calcined sludge consists primarily of amorphous particles of hydrous oxides with iron, manganese, nickel, and calcium distributed fairly uniformly throughout the powder. Iron, manganese, nickel, and calcium exist in forms that are highly insoluble in water, but aluminum, sulfate, nitrate, and sodium exhibit relative water solubilities that increase in the given order from 60% to 94%. Evolved gas analysis in a helium atmosphere showed that calcined sludge is completely dehydrated by heating to 400 0 C, carbon dioxide is evolved between 100 to 700 0 C with maximum evolution at 500 0 C, and oxygen is evolved between 400 and 1000 0 C. Evolved gas analyses are also reported for uncalcined sludge. A spinel-type oxide similar to NiFe 2 O 4 was detected by x-ray diffraction analysis at very low-level in calcined sludge

  10. Motion measurement for synthetic aperture radar

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-01-01

    Synthetic Aperture Radar (SAR) measures radar soundings from a set of locations typically along the flight path of a radar platform vehicle. Optimal focusing requires precise knowledge of the sounding source locations in 3-D space with respect to the target scene. Even data driven focusing techniques (i.e. autofocus) requires some degree of initial fidelity in the measurements of the motion of the radar. These requirements may be quite stringent especially for fine resolution, long ranges, and low velocities. The principal instrument for measuring motion is typically an Inertial Measurement Unit (IMU), but these instruments have inherent limi ted precision and accuracy. The question is %22How good does an IMU need to be for a SAR across its performance space?%22 This report analytically relates IMU specifications to parametric requirements for SAR. - 4 - Acknowledgements Th e preparation of this report is the result of a n unfunded research and development activity . Although this report is an independent effort, it draws heavily from limited - release documentation generated under a CRADA with General Atomics - Aeronautical System, Inc. (GA - ASI), and under the Joint DoD/DOE Munitions Program Memorandum of Understanding. Sandia National Laboratories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of En ergy's National Nuclear Security Administration under contract AC04-94AL85000.

  11. Study of chemical and physical properties of synthetic carbonaceous materials

    Energy Technology Data Exchange (ETDEWEB)

    Kaloc, M.; Lesko, J.; Martineg, P.; Rojak, A.; Roubicek, V.; Weiss, Z.

    1980-01-01

    Results are presented of studying the chemical and physical properties of 17 samples of synthetic carbonaceous materials (''carbons'') of different origin and with different degree of thermal treatment, and for comparison two samples of natural graphite were tested. For all the samples an analysis was made of the element composition and they were studied by the methods DTA, TGA, IR-spectrometry, x-ray analysis and electron screen microscopy. The studies indicated that proper combination of these methods can provide a high quality evaluation of the initial materials and the processes of their processing, and also the attained carbonaceous materials from the viewpoint of using them in the modern sectors of technology: electrical metallurgy, electrical chemistry and electrothermal production, nuclear technology, production of semiconductor materials, etc.

  12. Synthetic and systems biology for microbial production of commodity chemicals.

    Science.gov (United States)

    Chubukov, Victor; Mukhopadhyay, Aindrila; Petzold, Christopher J; Keasling, Jay D; Martín, Héctor García

    2016-01-01

    The combination of synthetic and systems biology is a powerful framework to study fundamental questions in biology and produce chemicals of immediate practical application such as biofuels, polymers, or therapeutics. However, we cannot yet engineer biological systems as easily and precisely as we engineer physical systems. In this review, we describe the path from the choice of target molecule to scaling production up to commercial volumes. We present and explain some of the current challenges and gaps in our knowledge that must be overcome in order to bring our bioengineering capabilities to the level of other engineering disciplines. Challenges start at molecule selection, where a difficult balance between economic potential and biological feasibility must be struck. Pathway design and construction have recently been revolutionized by next-generation sequencing and exponentially improving DNA synthesis capabilities. Although pathway optimization can be significantly aided by enzyme expression characterization through proteomics, choosing optimal relative protein expression levels for maximum production is still the subject of heuristic, non-systematic approaches. Toxic metabolic intermediates and proteins can significantly affect production, and dynamic pathway regulation emerges as a powerful but yet immature tool to prevent it. Host engineering arises as a much needed complement to pathway engineering for high bioproduct yields; and systems biology approaches such as stoichiometric modeling or growth coupling strategies are required. A final, and often underestimated, challenge is the successful scale up of processes to commercial volumes. Sustained efforts in improving reproducibility and predictability are needed for further development of bioengineering.

  13. EVALUATION OF CHEMICALLY BONDED PHOSPHATE CERAMICS FOR MERCURY STABILIZATION OF A MIXED SYNTHETIC WASTE

    Science.gov (United States)

    This experimental study was conducted to evaluate the stabilization and encapsulation technique developed by Argonne National Laboratory, called the Chemically Bonded Phosphate Ceramics technology for Hg- and HgCl2-contaminated synthetic waste materials. Leachability ...

  14. Chemically reduced graphene contains inherent metallic impurities present in parent natural and synthetic graphite.

    Science.gov (United States)

    Ambrosi, Adriano; Chua, Chun Kiang; Khezri, Bahareh; Sofer, Zdeněk; Webster, Richard D; Pumera, Martin

    2012-08-07

    Graphene-related materials are in the forefront of nanomaterial research. One of the most common ways to prepare graphenes is to oxidize graphite (natural or synthetic) to graphite oxide and exfoliate it to graphene oxide with consequent chemical reduction to chemically reduced graphene. Here, we show that both natural and synthetic graphite contain a large amount of metallic impurities that persist in the samples of graphite oxide after the oxidative treatment, and chemically reduced graphene after the chemical reduction. We demonstrate that, despite a substantial elimination during the oxidative treatment of graphite samples, a significant amount of impurities associated to the chemically reduced graphene materials still remain and alter their electrochemical properties dramatically. We propose a method for the purification of graphenes based on thermal treatment at 1,000 °C in chlorine atmosphere to reduce the effect of such impurities on the electrochemical properties. Our findings have important implications on the whole field of graphene research.

  15. Chemical vapour deposition synthetic diamond: materials, technology and applications

    International Nuclear Information System (INIS)

    Balmer, R S; Brandon, J R; Clewes, S L; Dhillon, H K; Dodson, J M; Friel, I; Inglis, P N; Madgwick, T D; Markham, M L; Mollart, T P; Perkins, N; Scarsbrook, G A; Twitchen, D J; Whitehead, A J; Wilman, J J; Woollard, S M

    2009-01-01

    Substantial developments have been achieved in the synthesis of chemical vapour deposition (CVD) diamond in recent years, providing engineers and designers with access to a large range of new diamond materials. CVD diamond has a number of outstanding material properties that can enable exceptional performance in applications as diverse as medical diagnostics, water treatment, radiation detection, high power electronics, consumer audio, magnetometry and novel lasers. Often the material is synthesized in planar form; however, non-planar geometries are also possible and enable a number of key applications. This paper reviews the material properties and characteristics of single crystal and polycrystalline CVD diamond, and how these can be utilized, focusing particularly on optics, electronics and electrochemistry. It also summarizes how CVD diamond can be tailored for specific applications, on the basis of the ability to synthesize a consistent and engineered high performance product.

  16. 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.

  17. Metabolic Engineering for Production of Biorenewable Fuels and Chemicals: Contributions of Synthetic Biology

    Directory of Open Access Journals (Sweden)

    Laura R. Jarboe

    2010-01-01

    Full Text Available Production of fuels and chemicals through microbial fermentation of plant material is a desirable alternative to petrochemical-based production. Fermentative production of biorenewable fuels and chemicals requires the engineering of biocatalysts that can quickly and efficiently convert sugars to target products at a cost that is competitive with existing petrochemical-based processes. It is also important that biocatalysts be robust to extreme fermentation conditions, biomass-derived inhibitors, and their target products. Traditional metabolic engineering has made great advances in this area, but synthetic biology has contributed and will continue to contribute to this field, particularly with next-generation biofuels. This work reviews the use of metabolic engineering and synthetic biology in biocatalyst engineering for biorenewable fuels and chemicals production, such as ethanol, butanol, acetate, lactate, succinate, alanine, and xylitol. We also examine the existing challenges in this area and discuss strategies for improving biocatalyst tolerance to chemical inhibitors.

  18. SYNBIOCHEM Synthetic Biology Research Centre, Manchester – A UK foundry for fine and speciality chemicals production

    Directory of Open Access Journals (Sweden)

    Le Feuvre RA

    2016-12-01

    Full Text Available The UK Synthetic Biology Research Centre, SYNBIOCHEM, hosted by the Manchester Institute of Biotechnology at the University of Manchester is delivering innovative technology platforms to facilitate the predictable engineering of microbial bio-factories for fine and speciality chemicals production. We provide an overview of our foundry activities that are being applied to grand challenge projects to deliver innovation in bio-based chemicals production for industrial biotechnology.

  19. An investigation of synthetic fuel production via chemical looping.

    Science.gov (United States)

    Zeman, Frank; Castaldi, Marco

    2008-04-15

    Producing liquid hydrocarbon fuels with a reduced greenhouse gas emissions profile would ease the transition to a carbon-neutral energy sector with the transportation industry being the immediate beneficiary followed by the power industry. Revolutionary solutions in transportation, such as electricity and hydrogen, depend on the deployment of carbon capture and storage technologies and/or renewable energy systems. Additionally, high oil prices may increase the development of unconventional sources, such as tar sands, that have a higher emissions profile. One process that is gaining interest is a system for producing reduced carbon fuels though chemical looping technologies. An investigation of the implications of such a process using methane and carbon dioxide that is reformed to yield methanol has been done. An important aspect of the investigation is the use of off-the-shelf technologies to achieve the results. The ability of the process to yield reduced emissions fuels depends on the source for the feed and process heat. For the range of conditions considered, the emissions profile of methanol produced in this method varies from 0.475 to 1.645 moles carbon dioxide per mole methanol. The upper bound can be lowered to 0.750 by applying CCS and/ or using nonfossil heat sources for the reforming. The process provides an initial pathway to incorporate CO2 into fuels independent of electrolytic hydrogen or developments in other sectors of the economy.

  20. Comparing measurement errors for formants in synthetic and natural vowels.

    Science.gov (United States)

    Shadle, Christine H; Nam, Hosung; Whalen, D H

    2016-02-01

    The measurement of formant frequencies of vowels is among the most common measurements in speech studies, but measurements are known to be biased by the particular fundamental frequency (F0) exciting the formants. Approaches to reducing the errors were assessed in two experiments. In the first, synthetic vowels were constructed with five different first formant (F1) values and nine different F0 values; formant bandwidths, and higher formant frequencies, were constant. Input formant values were compared to manual measurements and automatic measures using the linear prediction coding-Burg algorithm, linear prediction closed-phase covariance, the weighted linear prediction-attenuated main excitation (WLP-AME) algorithm [Alku, Pohjalainen, Vainio, Laukkanen, and Story (2013). J. Acoust. Soc. Am. 134(2), 1295-1313], spectra smoothed cepstrally and by averaging repeated discrete Fourier transforms. Formants were also measured manually from pruned reassigned spectrograms (RSs) [Fulop (2011). Speech Spectrum Analysis (Springer, Berlin)]. All but WLP-AME and RS had large errors in the direction of the strongest harmonic; the smallest errors occur with WLP-AME and RS. In the second experiment, these methods were used on vowels in isolated words spoken by four speakers. Results for the natural speech show that F0 bias affects all automatic methods, including WLP-AME; only the formants measured manually from RS appeared to be accurate. In addition, RS coped better with weaker formants and glottal fry.

  1. Hazardous chemicals in synthetic turf materials and their bioaccessibility in digestive fluids.

    Science.gov (United States)

    Zhang, Junfeng Jim; Han, In-Kyu; Zhang, Lin; Crain, William

    2008-11-01

    Many synthetic turf fields consist of not only artificial grass but also rubber granules that are used as infill. The public concerns about toxic chemicals possibly contained in either artificial (polyethylene) grass fibers or rubber granules have been escalating but are based on very limited information available to date. The aim of this research was to obtain data that will help assess potential health risks associated with chemical exposure. In this small-scale study, we collected seven samples of rubber granules and one sample of artificial grass fiber from synthetic turf fields at different ages of the fields. We analyzed these samples to determine the contents (maximum concentrations) of polycyclic aromatic hydrocarbons (PAHs) and several metals (Zn, Cr, As, Cd, and Pb). We also analyzed these samples to determine their bioaccessible fractions of PAHs and metals in synthetic digestive fluids including saliva, gastric fluid, and intestinal fluid through a laboratory simulation technique. Our findings include: (1) rubber granules often, especially when the synthetic turf fields were newer, contained PAHs at levels above health-based soil standards. The levels of PAHs generally appear to decline as the field ages. However, the decay trend may be complicated by adding new rubber granules to compensate for the loss of the material. (2) PAHs contained in rubber granules had zero or near-zero bioaccessibility in the synthetic digestive fluids. (3) The zinc contents were found to far exceed the soil limit. (4) Except one sample with a moderate lead content of 53 p.p.m., the other samples had relatively low concentrations of lead (3.12-5.76 p.p.m.), according to soil standards. However, 24.7-44.2% of the lead in the rubber granules was bioaccessible in the synthetic gastric fluid. (5) The artificial grass fiber sample showed a chromium content of 3.93 p.p.m., and 34.6% and 54.0% bioaccessibility of lead in the synthetic gastric and intestinal fluids, respectively.

  2. Prediction of novel synthetic pathways for the production of desired chemicals

    Directory of Open Access Journals (Sweden)

    Park Jin

    2010-03-01

    Full Text Available Abstract Background There have been several methods developed for the prediction of synthetic metabolic pathways leading to the production of desired chemicals. In these approaches, novel pathways were predicted based on chemical structure changes, enzymatic information, and/or reaction mechanisms, but the approaches generating a huge number of predicted results are difficult to be applied to real experiments. Also, some of these methods focus on specific pathways, and thus are limited to expansion to the whole metabolism. Results In the present study, we propose a system framework employing a retrosynthesis model with a prioritization scoring algorithm. This new strategy allows deducing the novel promising pathways for the synthesis of a desired chemical together with information on enzymes involved based on structural changes and reaction mechanisms present in the system database. The prioritization scoring algorithm employing Tanimoto coefficient and group contribution method allows examination of structurally qualified pathways to recognize which pathway is more appropriate. In addition, new concepts of binding site covalence, estimation of pathway distance and organism specificity were taken into account to identify the best synthetic pathway. Parameters of these factors can be evolutionarily optimized when a newly proven synthetic pathway is registered. As the proofs of concept, the novel synthetic pathways for the production of isobutanol, 3-hydroxypropionate, and butyryl-CoA were predicted. The prediction shows a high reliability, in which experimentally verified synthetic pathways were listed within the top 0.089% of the identified pathway candidates. Conclusions It is expected that the system framework developed in this study would be useful for the in silico design of novel metabolic pathways to be employed for the efficient production of chemicals, fuels and materials.

  3. Engineering the bioconversion of methane and methanol to fuels and chemicals in native and synthetic methylotrophs.

    Science.gov (United States)

    Bennett, R Kyle; Steinberg, Lisa M; Chen, Wilfred; Papoutsakis, Eleftherios T

    2018-04-01

    Methylotrophy describes the ability of organisms to utilize reduced one-carbon compounds, notably methane and methanol, as growth and energy sources. Abundant natural gas supplies, composed primarily of methane, have prompted interest in using these compounds, which are more reduced than sugars, as substrates to improve product titers and yields of bioprocesses. Engineering native methylotophs or developing synthetic methylotrophs are emerging fields to convert methane and methanol into fuels and chemicals under aerobic and anaerobic conditions. This review discusses recent progress made toward engineering native methanotrophs for aerobic and anaerobic methane utilization and synthetic methylotrophs for methanol utilization. Finally, strategies to overcome the limitations involved with synthetic methanol utilization, notably methanol dehydrogenase kinetics and ribulose 5-phosphate regeneration, are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Synthetic Pulse Dilation - PMT Model for high bandwidth gamma measurements

    Science.gov (United States)

    Geppert-Kleinrath, H.; Herrmann, H. W.; Kim, Y. H.; Zylstra, A. B.; Meaney, K. D.; Lopez, F. E.; Khater, H.; Horsfield, C. J.; Gales, S.; Leatherland, A.; Hilsabeck, T.; Kilkenny, J. D.; Hares, J. D.; Dymoke-Bradshaw, T.; Milnes, J.

    2017-10-01

    The Cherenkov mechanism used in Gas Cherenkov Detectors (GCD) is exceptionally fast. However, the temporal resolution of GCDs, such as the Gamma Reaction History diagnostic (GRH), is limited by the current state-of-the-art photomultiplier tube (PMT) to 100 ps. The new pulse dilation - PMT (PD-PMT) for NIF allows for a temporal resolution comparable to that of the gas cell, or of 10ps. Enhanced resolution will contribute to the quest for ignition in a crucial way through precision measurement of reaction history and areal density (ρ R) history, leading to better constrained models. Features such as onset of alpha heating, shock reverberations and burn truncation due to dynamically evolving failure modes will become visible for the first time. PD-PMT will be deployed on GCD-3 at NIF in 2018. Our synthetic PD-PMT model evaluates the capabilities of these future measurements, as well as minimum yield requirements for measurements performed in a well at 3.9 m from target chamber center (TCC), and within a diagnostic inserter at 0.2m from TCC.

  5. Mapping the patent landscape of synthetic biology for fine chemical production pathways.

    Science.gov (United States)

    Carbonell, Pablo; Gök, Abdullah; Shapira, Philip; Faulon, Jean-Loup

    2016-09-01

    A goal of synthetic biology bio-foundries is to innovate through an iterative design/build/test/learn pipeline. In assessing the value of new chemical production routes, the intellectual property (IP) novelty of the pathway is important. Exploratory studies can be carried using knowledge of the patent/IP landscape for synthetic biology and metabolic engineering. In this paper, we perform an assessment of pathways as potential targets for chemical production across the full catalogue of reachable chemicals in the extended metabolic space of chassis organisms, as computed by the retrosynthesis-based algorithm RetroPath. Our database for reactions processed by sequences in heterologous pathways was screened against the PatSeq database, a comprehensive collection of more than 150M sequences present in patent grants and applications. We also examine related patent families using Derwent Innovations. This large-scale computational study provides useful insights into the IP landscape of synthetic biology for fine and specialty chemicals production. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  6. Application of synthetic biology for production of chemicals in yeast Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Borodina, Irina; Li, Mingji

    2015-01-01

    Synthetic biology and metabolic engineering enable generation of novel cell factories that efficiently convert renewable feedstocks into biofuels, bulk, and fine chemicals, thus creating the basis for biosustainable economy independent on fossil resources. While over a hundred proof-of-concept ch......Synthetic biology and metabolic engineering enable generation of novel cell factories that efficiently convert renewable feedstocks into biofuels, bulk, and fine chemicals, thus creating the basis for biosustainable economy independent on fossil resources. While over a hundred proof...... computational tools for the prediction of biochemical pathways, molecular biology methods for assembly of DNA parts into pathways, and for introducing the pathways into the host, and finally approaches for optimizing performance of the introduced pathways....

  7. Application of synthetic biology for production of chemicals in yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Li, Mingji; Borodina, Irina

    2015-02-01

    Synthetic biology and metabolic engineering enable generation of novel cell factories that efficiently convert renewable feedstocks into biofuels, bulk, and fine chemicals, thus creating the basis for biosustainable economy independent on fossil resources. While over a hundred proof-of-concept chemicals have been made in yeast, only a very small fraction of those has reached commercial-scale production so far. The limiting factor is the high research cost associated with the development of a robust cell factory that can produce the desired chemical at high titer, rate, and yield. Synthetic biology has the potential to bring down this cost by improving our ability to predictably engineer biological systems. This review highlights synthetic biology applications for design, assembly, and optimization of non-native biochemical pathways in baker's yeast Saccharomyces cerevisiae We describe computational tools for the prediction of biochemical pathways, molecular biology methods for assembly of DNA parts into pathways, and for introducing the pathways into the host, and finally approaches for optimizing performance of the introduced pathways. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

  8. Biomass characteristics in three sequencing batch reactors treating a wastewater containing synthetic organic chemicals

    DEFF Research Database (Denmark)

    Hu, Z.Q.; Ferraina, R.A.; Ericson, J.F.

    2005-01-01

    The physical and biochemical characteristics of the biomass in three lab-scale sequencing batch reactors (SBR) treating a synthetic wastewater at a 20-day target solids retention time (SRT) were investigated. The synthetic wastewater feed contained biogenic compounds and 22 organic priming...... compounds, chosen to represent a wide variety of chemical structures with different N, P and S functional groups. At a two-day hydraulic retention time (HRT), the oxidation-reduction potential (ORP) cycled between -100 (anoxic) and 100mV (aerobic) in the anoxic/aerobic SBR, while it remained in a range...... of 126 +/- 18 and 249 +/- 18 mV in the aerobic sequencing batch biofilm reactor (SBBR) and the aerobic SBR reactor, respectively. A granular activated sludge with excellent settleability (SVI = 98 +/- 31 L mg(-1)) developed only in the anoxic/aerobic SBR, compared to a bulky sludge with poor settling...

  9. Synthetic biology to access and expand nature’s chemical diversity

    Science.gov (United States)

    Smanski, Michael J.; Zhou, Hui; Claesen, Jan; Shen, Ben; Fischbach, Michael; Voigt, Christopher A.

    2016-01-01

    Bacterial genomes encode the biosynthetic potential to produce hundreds of thousands of complex molecules with diverse applications, from medicine to agriculture and materials. Economically accessing the potential encoded within sequenced genomes promises to reinvigorate waning drug discovery pipelines and provide novel routes to intricate chemicals. This is a tremendous undertaking, as the pathways often comprise dozens of genes spanning as much as 100+ kiliobases of DNA, are controlled by complex regulatory networks, and the most interesting molecules are made by non-model organisms. Advances in synthetic biology address these issues, including DNA construction technologies, genetic parts for precision expression control, synthetic regulatory circuits, computer aided design, and multiplexed genome engineering. Collectively, these technologies are moving towards an era when chemicals can be accessed en mass based on sequence information alone. This will enable the harnessing of metagenomic data and massive strain banks for high-throughput molecular discovery and, ultimately, the ability to forward design pathways to complex chemicals not found in nature. PMID:26876034

  10. Synthetic nat- or ent-steroids in as few as five chemical steps from epichlorohydrin

    Science.gov (United States)

    Kim, Wan Shin; Du, Kang; Eastman, Alan; Hughes, Russell P.; Micalizio, Glenn C.

    2018-01-01

    Today, more than 100 Food and Drug Administration-approved steroidal agents are prescribed daily for indications including heart failure, inflammation, pain and cancer. While triumphs in organic chemistry have enabled the establishment and sustained growth of the steroid pharmaceutical industry, the production of highly functionalized synthetic steroids of varying substitution and stereochemistry remains challenging, despite the numerous reports of elegant strategies for their de novo synthesis. Here, we describe an advance in chemical synthesis that has established an enantiospecific means to access novel steroids with unprecedented facility and flexibility through the sequential use of two powerful ring-forming reactions: a modern metallacycle-mediated annulative cross-coupling and a new acid-catalysed vinylcyclopropane rearrangement cascade. In addition to accessing synthetic steroids of either enantiomeric series, these steroidal products have been selectively functionalized within each of the four carbocyclic rings, a synthetic ent-steroid has been prepared on a multigram scale, the enantiomer of a selective oestrogen has been synthesized, and a novel ent-steroid with growth inhibitory properties in three cancer cell lines has been discovered.

  11. Radiation Dose Measurement Using Chemical Dosimeters

    International Nuclear Information System (INIS)

    Lee, Min Sun; Kim, Eun Hee; Kim, Yu Ri; Han, Bum Soo

    2010-01-01

    The radiation dose can be estimated in various ways. Dose estimates can be obtained by either experiment or theoretical analysis. In experiments, radiation impact is assessed by measuring any change caused by energy deposition to the exposed matter, in terms of energy state (physical change), chemical production (chemical change) or biological abnormality (biological change). The chemical dosimetry is based on the implication that the energy deposited to the matter can be inferred from the consequential change in chemical production. The chemical dosimetry usually works on the sample that is an aqueous solution, a biological matter, or an organic substance. In this study, we estimated absorbed doses by quantitating chemical changes in matter caused by radiation exposure. Two different chemical dosimeters, Fricke and ECB (Ethanol-Chlorobenzene) dosimeter, were compared in several features including efficacy as dose indicator and effective dose range

  12. Toxicogenomic responses in rainbow trout (Oncorhynchus mykiss) hepatocytes exposed to model chemicals and a synthetic mixture

    Energy Technology Data Exchange (ETDEWEB)

    Finne, E.F. [Norwegian Institute for Water Research, Gaustadalleen 21, N-0349 Oslo (Norway) and University of Oslo, Department of Biology, P.O. Box 1066, Blindern, N-0316 Oslo (Norway)]. E-mail: eivind.finne@niva.no; Cooper, G.A. [Centre for Biomedical Research, University of Victoria, BC V8P5C2 (Canada); Koop, B.F. [Centre for Biomedical Research, University of Victoria, BC V8P5C2 (Canada); Hylland, K. [Norwegian Institute for Water Research, Gaustadalleen 21, N-0349 Oslo (Norway); University of Oslo, Department of Biology, P.O. Box 1066, Blindern, N-0316 Oslo (Norway); Tollefsen, K.E. [Norwegian Institute for Water Research, Gaustadalleen 21, N-0349 Oslo (Norway)

    2007-03-10

    As more salmon gene expression data has become available, the cDNA microarray platform has emerged as an appealing alternative in ecotoxicological screening of single chemicals and environmental samples relevant to the aquatic environment. This study was performed to validate biomarker gene responses of in vitro cultured rainbow trout (Oncorhynchus mykiss) hepatocytes exposed to model chemicals, and to investigate effects of mixture toxicity in a synthetic mixture. Chemicals used for 24 h single chemical- and mixture exposures were 10 nM 17{alpha}-ethinylestradiol (EE2), 0.75 nM 2,3,7,8-tetrachloro-di-benzodioxin (TCDD), 100 {mu}M paraquat (PQ) and 0.75 {mu}M 4-nitroquinoline-1-oxide (NQO). RNA was isolated from exposed cells, DNAse treated and quality controlled before cDNA synthesis, fluorescent labelling and hybridisation to a 16k salmonid microarray. The salmonid 16k cDNA array identified differential gene expression predictive of exposure, which could be verified by quantitative real time PCR. More precisely, the responses of biomarker genes such as cytochrome p4501A and UDP-glucuronosyl transferase to TCDD exposure, glutathione reductase and gammaglutamyl cysteine synthetase to paraquat exposure, as well as vitellogenin and vitelline envelope protein to EE2 exposure validated the use of microarray applied to RNA extracted from in vitro exposed hepatocytes. The mutagenic compound NQO did not result in any change in gene expression. Results from exposure to a synthetic mixture of the same four chemicals, using identical concentrations as for single chemical exposures, revealed combined effects that were not predicted by results for individual chemicals alone. In general, the response of exposure to this mixture led to an average loss of approximately 60% of the transcriptomic signature found for single chemical exposure. The present findings show that microarray analyses may contribute to our mechanistic understanding of single contaminant mode of action as

  13. Toxicogenomic responses in rainbow trout (Oncorhynchus mykiss) hepatocytes exposed to model chemicals and a synthetic mixture

    International Nuclear Information System (INIS)

    Finne, E.F.; Cooper, G.A.; Koop, B.F.; Hylland, K.; Tollefsen, K.E.

    2007-01-01

    As more salmon gene expression data has become available, the cDNA microarray platform has emerged as an appealing alternative in ecotoxicological screening of single chemicals and environmental samples relevant to the aquatic environment. This study was performed to validate biomarker gene responses of in vitro cultured rainbow trout (Oncorhynchus mykiss) hepatocytes exposed to model chemicals, and to investigate effects of mixture toxicity in a synthetic mixture. Chemicals used for 24 h single chemical- and mixture exposures were 10 nM 17α-ethinylestradiol (EE2), 0.75 nM 2,3,7,8-tetrachloro-di-benzodioxin (TCDD), 100 μM paraquat (PQ) and 0.75 μM 4-nitroquinoline-1-oxide (NQO). RNA was isolated from exposed cells, DNAse treated and quality controlled before cDNA synthesis, fluorescent labelling and hybridisation to a 16k salmonid microarray. The salmonid 16k cDNA array identified differential gene expression predictive of exposure, which could be verified by quantitative real time PCR. More precisely, the responses of biomarker genes such as cytochrome p4501A and UDP-glucuronosyl transferase to TCDD exposure, glutathione reductase and gammaglutamyl cysteine synthetase to paraquat exposure, as well as vitellogenin and vitelline envelope protein to EE2 exposure validated the use of microarray applied to RNA extracted from in vitro exposed hepatocytes. The mutagenic compound NQO did not result in any change in gene expression. Results from exposure to a synthetic mixture of the same four chemicals, using identical concentrations as for single chemical exposures, revealed combined effects that were not predicted by results for individual chemicals alone. In general, the response of exposure to this mixture led to an average loss of approximately 60% of the transcriptomic signature found for single chemical exposure. The present findings show that microarray analyses may contribute to our mechanistic understanding of single contaminant mode of action as well as

  14. Impact of synthetic biology and metabolic engineering on industrial production of fine chemicals.

    Science.gov (United States)

    Jullesson, David; David, Florian; Pfleger, Brian; Nielsen, Jens

    2015-11-15

    Industrial bio-processes for fine chemical production are increasingly relying on cell factories developed through metabolic engineering and synthetic biology. The use of high throughput techniques and automation for the design of cell factories, and especially platform strains, has played an important role in the transition from laboratory research to industrial production. Model organisms such as Saccharomyces cerevisiae and Escherichia coli remain widely used host strains for industrial production due to their robust and desirable traits. This review describes some of the bio-based fine chemicals that have reached the market, key metabolic engineering tools that have allowed this to happen and some of the companies that are currently utilizing these technologies for developing industrial production processes. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Impact of synthetic biology and metabolic engineering on industrial production of fine chemicals

    DEFF Research Database (Denmark)

    Jullesson, David; David, Florian; Pfleger, Brian

    2015-01-01

    Industrial bio-processes for fine chemical production are increasingly relying on cell factories developed through metabolic engineering and synthetic biology. The use of high throughput techniques and automation for the design of cell factories, and especially platform strains, has played...... an important role in the transition from laboratory research to industrial production. Model organisms such as Saccharomyces cerevisiae and Escherichia coli remain widely used host strains for industrial production due to their robust and desirable traits. This review describes some of the bio-based fine...... chemicals that have reached the market, key metabolic engineering tools that have allowed this to happen and some of the companies that are currently utilizing these technologies for developing industrial production processes....

  16. Direct measurements of intermolecular forces by chemical force microscopy

    Science.gov (United States)

    Vezenov, Dmitri Vitalievich

    1999-12-01

    Detailed description of intermolecular forces is key to understanding a wide range of phenomena from molecular recognition to materials failure. The unique features of atomic force microscopy (AFM) to make point contact force measurements with ultra high sensitivity and to generate spatial maps of surface topography and forces have been extended to include measurements between well-defined organic molecular groups. Chemical modification of AFM probes with self-assembled monolayers (SAMs) was used to make them sensitive to specific molecular interactions. This novel chemical force microscopy (CFM) technique was used to probe forces between different molecular groups in a range of environments (vacuum, organic liquids and aqueous solutions); measure surface energetics on a nanometer scale; determine pK values of the surface acid and base groups; measure forces to stretch and unbind a short synthetic DNA duplex and map the spatial distribution of specific functional groups and their ionization state. Studies of adhesion forces demonstrated the important contribution of hydrogen bonding to interactions between simple organic functionalities. The chemical identity of the tip and substrate surfaces as well as the medium had a dramatic effect on adhesion between model monolayers. A direct correlation between surface free energy and adhesion forces was established. The adhesion between epoxy polymer and model mixed SAMs varied with the amount of hydrogen bonding component in the monolayers. A consistent interpretation of CFM measurements in polar solvents was provided by contact mechanics models and intermolecular force components theory. Forces between tips and surfaces functionalized with SAMs terminating in acid or base groups depended on their ionization state. A novel method of force titration was introduced for highly local characterization of the pK's of surface functional groups. The pH-dependent changes in friction forces were exploited to map spatially the

  17. 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.

  18. Direct spectroscopic observation of singlet oxygen quenching and kinetic studies of physical and chemical singlet oxygen quenching rate constants of synthetic antioxidants (BHA, BHT, and TBHQ) in methanol.

    Science.gov (United States)

    Lee, Jun Hyun; Jung, Mun Yhung

    2010-08-01

    Singlet oxygen quenching by synthetic antioxidants (BHA, BHT, and TBHQ) was directly observed by spectroscopic monitoring of luminescence at 1268 nm. The luminescence data showed unambiguous evidence of singlet oxygen quenching by synthetic phenolic antioxidants with the highest activity for TBHQ, followed by BHA and BHT. The protective activities of these synthetic antioxidants on alpha-terpinene oxidation with chemically-induced singlet oxygen under dark further confirmed their singlet oxygen quenching abilities. Total singlet oxygen quenching rate constants (k(r) + k(q)) of BHA, BHT, and TBHQ were determined in a system containing alpha-terpinene (as a singlet oxygen trap) and methylene blue (as a sensitizer) during light irradiation, and the values were 5.14 x 10(7), 3.41 x 10(6), and 1.99 x 10(8) M(-1)s(-1), respectively. After the k(r) value of alpha-terpinene was first determined, the k(r) values of the synthetic antioxidants were calculated by measuring their relative reaction rates with singlet oxygen to that of alpha-terpinene under the identical conditions. The k(r) values of the BHA, BHT, and TBHQ were 3.90 x 10(5), 1.23 x 10(5), and 2.93 x 10(6), M(-1)s(-1). The percent partition of chemical quenching over total singlet oxygen quenching (k(r) x 100)/(k(r) + k(q)) for BHA, BHT, and TBHQ were 0.76%, 3.61%, and 1.47%, respectively. The results showed that the synthetic antioxidants quench singlet oxygen almost exclusively through the mechanism of physical quenching. This represents the first report on the singlet oxygen quenching mechanism of these synthetic antioxidants. Practical Application: The synthetic antioxidants, especially TBHQ, have been found to have a strong singlet oxygen quenching ability. This article also clearly showed that singlet oxygen quenching by synthetic antioxidants was mainly by the physical quenching mechanism. The results suggested that these synthetic antioxidants, especially TBHQ, could be used practically for the protection

  19. Synthetic Aperture Interferometry: In-Process Measurement of Aspheric Optics

    Science.gov (United States)

    Tomlinson, Richard; Coupland, Jeremy M.; Petzing, Jon

    2003-02-01

    A scanning probe consisting of a source and receive fiber pair is used to measure the phase difference between wave fronts scattered from the front and rear surfaces of an aspheric optic. This system can be thought of as a classical interferometer with an aperture synthesized from the data collected along the path of the probe. If the form of either surface is known, the other can be deduced. In contrast with classical interferometers, the method does not need test or null plates and has the potential to be integrated into the manufacturing process.

  20. Physical, chemical, and metabolic state sensors expand the synthetic biology toolbox for Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Immethun, Cheryl M; DeLorenzo, Drew M; Focht, Caroline M; Gupta, Dinesh; Johnson, Charles B; Moon, Tae Seok

    2017-07-01

    Many under-developed organisms possess important traits that can boost the effectiveness and sustainability of microbial biotechnology. Photoautotrophic cyanobacteria can utilize the energy captured from light to fix carbon dioxide for their metabolic needs while living in environments not suited for growing crops. Various value-added compounds have been produced by cyanobacteria in the laboratory; yet, the products' titers and yields are often not industrially relevant and lag behind what have been accomplished in heterotrophic microbes. Genetic tools for biological process control are needed to take advantage of cyanobacteria's beneficial qualities, as tool development also lags behind what has been created in common heterotrophic hosts. To address this problem, we developed a suite of sensors that regulate transcription in the model cyanobacterium Synechocystis sp. PCC 6803 in response to metabolically relevant signals, including light and the cell's nitrogen status, and a family of sensors that respond to the inexpensive chemical, l-arabinose. Increasing the number of available tools enables more complex and precise control of gene expression. Expanding the synthetic biology toolbox for this cyanobacterium also improves our ability to utilize this important under-developed organism in biotechnology. Biotechnol. Bioeng. 2017;114: 1561-1569. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  1. Removal of a synthetic organic chemical by PAC-UF systems. II: Model application.

    Science.gov (United States)

    Matsui, Y; Colas, F; Yuasa, A

    2001-02-01

    This paper describes several application potentials with a recently developed model for predicting the synthetic organic chemical (SOC) removal by powdered activated carbon (PAC) adsorption during ultrafiltration (UF) and discusses the removal mechanism. The model was successfully applied, without any modification, to dead-end mode operation as well as to cross-flow mode operation, validating the assumption of the internal diffusion control mechanism and the continuously-stirred-tank-reactor (CSTR) concept. Even when UF was operated in a cross-flow mode, PAC added was re-circulating in suspension for only a short time. Then, solute uptake took place mostly by PAC immobilized in membrane tubes not only for dead-end operation but also for cross-flow operation. Therefore, cross-flow operation did not have any advantage regarding the SOC mass transfer on PAC in UF loop over dead-end operation. The model simulation implied that pulse PAC addition at the beginning of filtration cycle resulted better SOC removal than continuous PAC addition. However, for the pulse PAC addition mode, the model predicted somewhat lower effluent SOC concentration than the observed values, and the benefit of pulse PAC application in terms of reducing SOC over its continuous dosage was not confirmed. Longer detention time of PAC dosed in a pulse than continuously dosed PAC could possibly further decrease internal diffusivity.

  2. Synthetic oils

    Science.gov (United States)

    Hatton, R. E.

    1973-01-01

    Synthetic lubricants are discussed by chemical class and their general strengths and weaknesses in terms of lubrication properties are analyzed. Comparative ratings are given for 14 chemical classes and are used as a guide for lubricant selection. The effects of chemical structure on the properties of the lubricant are described with special emphasis on thermal stability. The diversity of synthetic lubricants which is provided by the wide range of properties permits many applications, some of which are reported.

  3. Limitations of using synthetic blood clots for measuring in vitro clot capture efficiency of inferior vena cava filters.

    Science.gov (United States)

    Robinson, Ronald A; Herbertson, Luke H; Sarkar Das, Srilekha; Malinauskas, Richard A; Pritchard, William F; Grossman, Laurence W

    2013-01-01

    The purpose of this study was first to evaluate the clot capture efficiency and capture location of six currently-marketed vena cava filters in a physiological venous flow loop, using synthetic polyacrylamide hydrogel clots, which were intended to simulate actual blood clots. After observing a measured anomaly for one of the test filters, we redirected the focus of the study to identify the cause of poor clot capture performance for large synthetic hydrogel clots. We hypothesized that the uncharacteristic low clot capture efficiency observed when testing the outlying filter can be attributed to the inadvertent use of dense, stiff synthetic hydrogel clots, and not as a result of the filter design or filter orientation. To study this issue, sheep blood clots and polyacrylamide (PA) synthetic clots were injected into a mock venous flow loop containing a clinical inferior vena cava (IVC) filter, and their captures were observed. Testing was performed with clots of various diameters (3.2, 4.8, and 6.4 mm), length-to-diameter ratios (1:1, 3:1, 10:1), and stiffness. By adjusting the chemical formulation, PA clots were fabricated to be soft, moderately stiff, or stiff with elastic moduli of 805 ± 2, 1696 ± 10 and 3295 ± 37 Pa, respectively. In comparison, the elastic moduli for freshly prepared sheep blood clots were 1690 ± 360 Pa. The outlying filter had a design that was characterized by peripheral gaps (up to 14 mm) between its wire struts. While a low clot capture rate was observed using large, stiff synthetic clots, the filter effectively captured similarly sized sheep blood clots and soft PA clots. Because the stiffer synthetic clots remained straight when approaching the filter in the IVC model flow loop, they were more likely to pass between the peripheral filter struts, while the softer, physiological clots tended to fold and were captured by the filter. These experiments demonstrated that if synthetic clots are used as a surrogate for animal or human blood

  4. Limitations of using synthetic blood clots for measuring in vitro clot capture efficiency of inferior vena cava filters

    Directory of Open Access Journals (Sweden)

    Robinson RA

    2013-05-01

    Full Text Available Ronald A Robinson, Luke H Herbertson, Srilekha Sarkar Das, Richard A Malinauskas, William F Pritchard, Laurence W GrossmanOffice of Science and Engineering Laboratories, Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, MD, USAAbstract: The purpose of this study was first to evaluate the clot capture efficiency and capture location of six currently-marketed vena cava filters in a physiological venous flow loop, using synthetic polyacrylamide hydrogel clots, which were intended to simulate actual blood clots. After observing a measured anomaly for one of the test filters, we redirected the focus of the study to identify the cause of poor clot capture performance for large synthetic hydrogel clots. We hypothesized that the uncharacteristic low clot capture efficiency observed when testing the outlying filter can be attributed to the inadvertent use of dense, stiff synthetic hydrogel clots, and not as a result of the filter design or filter orientation. To study this issue, sheep blood clots and polyacrylamide (PA synthetic clots were injected into a mock venous flow loop containing a clinical inferior vena cava (IVC filter, and their captures were observed. Testing was performed with clots of various diameters (3.2, 4.8, and 6.4 mm, length-to-diameter ratios (1:1, 3:1, 10:1, and stiffness. By adjusting the chemical formulation, PA clots were fabricated to be soft, moderately stiff, or stiff with elastic moduli of 805 ± 2, 1696 ± 10 and 3295 ± 37 Pa, respectively. In comparison, the elastic moduli for freshly prepared sheep blood clots were 1690 ± 360 Pa. The outlying filter had a design that was characterized by peripheral gaps (up to 14 mm between its wire struts. While a low clot capture rate was observed using large, stiff synthetic clots, the filter effectively captured similarly sized sheep blood clots and soft PA clots. Because the stiffer synthetic clots remained straight when approaching the

  5. Laboratory measurements of P- and S-wave anisotropy in synthetic rocks by 3D printing

    Science.gov (United States)

    Kong, L.; Ostadhassan, M.; Tamimi, N.; Li, C.; Alexeyev, A.

    2017-12-01

    Synthetic rocks have been widely used to realize the models with controlled factors in rock physics and geomechanics experiments. Additive manufacturing technology, known as 3D printing, is becoming a popular method to produce the synthetic rocks as the advantages of timesaving, economics, and control. In terms of mechanical properties, the duplicability of 3D printed rock towards a natural rock has been studied whereas the seismic anisotropy still remains unknown as being the key factor in conducting rock physics experiments. This study utilized a 3D printer with gypsum as the ink to manufacture a series of synthetic rocks that have the shapes of octagonal prisms, with half of them printed from lateral and another half from the bottom. An ultrasonic investigation system was set up to measure the P- and S- wave velocities at different frequencies while samples were under dry conditions. The results show the impact of layered property on the P- and S- wave velocities. The measurement results were compared with the predicted results of Hudson model, demonstrating that the synthetic rock from 3D printing is a transverse isotropic model. The seismic anisotropy indicates that the availability of using 3D printed rocks to duplicate natural rocks for the purpose of recreating the experiments of rock physics. Future experiments will be performed on the dependence of seismic anisotropy on fracture geometry and density in 3D printed synthetic rocks.

  6. Influence of pre-measurement thermal treatment on OSL of synthetic quartz measured at room temperature

    International Nuclear Information System (INIS)

    Kale, Y.D.; Gandhi, Y.H.

    2008-01-01

    Much effort has been made to study the influence of pre-measurement thermal treatment and ionizing radiation on quartz specimens owing to its use in a large number of applications. Optically stimulated luminescence (OSL) being a structured and sensitive phenomenon promises to correlate the responsible color center and luminescence emission. OSL studies on quartz with such conditions can reveal many significant results. The aim of the present investigation is to understand the effect of annealing temperature on OSL characteristics of synthetic quartz recorded at room temperature. At identical annealing duration and β-dose, the shape of OSL decay curve remains non-exponential; when specimens annealed at lower temperature (∼400 deg. C). The shape of decay curve changes to exponential in nature along with rise in OSL intensity when the specimen was given higher temperature of annealing (>400 deg. C). The effects of such protocol on pattern of OSL sensitivity as well as area under the OSL decay curve are also presented here. The presence of shallow traps, when OSL decay curve was recorded at room temperature seems to be responsible for the changes in OSL pattern. The influence of shallow traps is attributed to non-exponential decay of OSL recorded at room temperature

  7. Synthetic methylotrophy: engineering the production of biofuels and chemicals based on the biology of aerobic methanol utilization.

    Science.gov (United States)

    Whitaker, William B; Sandoval, Nicholas R; Bennett, Robert K; Fast, Alan G; Papoutsakis, Eleftherios T

    2015-06-01

    Synthetic methylotrophy is the development of non-native methylotrophs that can utilize methane and methanol as sole carbon and energy sources or as co-substrates with carbohydrates to produce metabolites as biofuels and chemicals. The availability of methane (from natural gas) and its oxidation product, methanol, has been increasing, while prices have been decreasing, thus rendering them as attractive fermentation substrates. As they are more reduced than most carbohydrates, methane and methanol, as co-substrates, can enhance the yields of biologically produced metabolites. Here we discuss synthetic biology and metabolic engineering strategies based on the native biology of aerobic methylotrophs for developing synthetic strains grown on methanol, with Escherichia coli as the prototype. Copyright © 2015. Published by Elsevier Ltd.

  8. Experimental and quantum chemical studies of a novel synthetic prenylated chalcone

    Directory of Open Access Journals (Sweden)

    Espinoza-Hicks José C

    2013-01-01

    Full Text Available Abstract Background Chalcones are ubiquitous natural compounds with a wide variety of reported biological activities, including antitumoral, antiviral and antimicrobial effects. Furthermore, chalcones are being studied for its potential use in organic electroluminescent devices; therefore the description of their spectroscopic properties is important to elucidate the structure of these molecules. One of the main techniques available for structure elucidation is the use of Nuclear Magnetic Resonance Spectroscopy (NMR. Accordingly, the prediction of the NMR spectra in this kind of molecules is necessary to gather information about the influence of substituents on their spectra. Results A novel substituted chalcone has been synthetized. In order to identify the functional groups present in the new synthesized compound and confirm its chemical structure, experimental and theoretical 1H-NMR and 13C-NMR spectra were analyzed. The theoretical molecular structure and NMR spectra were calculated at both the Hartree-Fock and Density Functional (meta: TPSS; hybrid: B3LYP and PBE1PBE; hybrid meta GGA: M05-2X and M06-2X levels of theory in combination with a 6-311++G(d,p basis set. The structural parameters showed that the best method for geometry optimization was DFT:M06-2X/6-311++G(d,p, whereas the calculated bond angles and bond distances match experimental values of similar chalcone derivatives. The NMR calculations were carried out using the Gauge-Independent Atomic Orbital (GIAO formalism in a DFT:M06-2X/6-311++G(d,p optimized geometry. Conclusion Considering all HF and DFT methods with GIAO calculations, TPSS and PBE1PBE were the most accurate methods used for calculation of 1H-NMR and 13C-NMR chemical shifts, which was almost similar to the B3LYP functional, followed in order by HF, M05-2X and M06-2X methods. All calculations were done using the Gaussian 09 software package. Theoretical calculations can be used to predict and confirm the structure of

  9. Measures to implement the Chemical Weapons Convention

    International Nuclear Information System (INIS)

    Tanzman, E.; Kellman, B.

    1999-01-01

    This seminar is another excellent opportunity for those involved in preventing chemical weapons production and use to learn from each other about how the Chemical Weapons Convention (CWC) can become a foundation of arms control in Africa and around the world. The author is grateful to the staff of the Organization for the Prohibition of Chemical Weapons (OPCW) for inviting him to address this distinguished seminar. The views expressed in this paper are those of the authors alone, and do not represent the position of the government of the US nor or of any other institution. In 1993, as the process of CWC ratification was beginning, concerns arose that the complexity of integrating the treaty with national law would cause each nation to implement the Convention without regard to what other nations were doing, thereby causing inconsistencies among States Parties in how the Convention would be carried out. As a result the Manual for National Implementation of the Chemical Weapons Convention was prepared and presented it to each national delegation at the December 1993 meeting of the Preparatory Commission in The Hague. During its preparation, the Manual was reviewed by the Committee of Legal Experts on National Implementation of the Chemical Weapons Convention, a group of distinguished international jurists, law professors, legally-trained diplomats, government officials, and Parliamentarians from every region of the world, including Mica. In February 1998, the second edition of the Manual was published in order to update it in light of developments since the CWC entered into force on 29 April 1997. The second edition 1998 clarified the national implementation options to reflect post-entry-into-force thinking, added extensive references to national implementing measures that had been enacted by various States Parties, and included a prototype national implementing statute developed by the authors to provide a starting point for those whose national implementing

  10. Measures to implement the Chemical Weapons Convention

    Energy Technology Data Exchange (ETDEWEB)

    Tanzman, E.; Kellman, B.

    1999-11-05

    This seminar is another excellent opportunity for those involved in preventing chemical weapons production and use to learn from each other about how the Chemical Weapons Convention (CWC) can become a foundation of arms control in Africa and around the world. The author is grateful to the staff of the Organization for the Prohibition of Chemical Weapons (OPCW) for inviting him to address this distinguished seminar. The views expressed in this paper are those of the authors alone, and do not represent the position of the government of the US nor or of any other institution. In 1993, as the process of CWC ratification was beginning, concerns arose that the complexity of integrating the treaty with national law would cause each nation to implement the Convention without regard to what other nations were doing, thereby causing inconsistencies among States Parties in how the Convention would be carried out. As a result the Manual for National Implementation of the Chemical Weapons Convention was prepared and presented it to each national delegation at the December 1993 meeting of the Preparatory Commission in The Hague. During its preparation, the Manual was reviewed by the Committee of Legal Experts on National Implementation of the Chemical Weapons Convention, a group of distinguished international jurists, law professors, legally-trained diplomats, government officials, and Parliamentarians from every region of the world, including Mica. In February 1998, the second edition of the Manual was published in order to update it in light of developments since the CWC entered into force on 29 April 1997. The second edition 1998 clarified the national implementation options to reflect post-entry-into-force thinking, added extensive references to national implementing measures that had been enacted by various States Parties, and included a prototype national implementing statute developed by the authors to provide a starting point for those whose national implementing

  11. Heavy ion measurement by chemical detectors

    International Nuclear Information System (INIS)

    Huebner, K.; Erzgraeber, G.; Eichhorn, K.

    1979-02-01

    In testing the applicability of the threshold system polyvinyl alcohol/methyl orange/chloral hydrate/sodium tetraborate to the quantitative detection of single particles, the chemical detector was irradiated with 4 He, 12 C, 18 O, 22 He ions of different LET. Detectors with 4 different borax concentrations (chloral hydrate concentration kept constant) have been irradiated. The dose causing the colour change increased linearly with the borax concentration. For equal borax concentrations this dose increases with increasing LET due to the decreasing G value of the HCl. The fluence ranges measurable with the various detector compositions are given. 4 He and 18 O ion ranges have been determined. The measured depth dose curves have been corrected because the dose is LET-dependent. The experimentally determined ranges are in good agreement with values calculated for the detector material

  12. Physical and chemical characteristics of synthetic asphalt produced from liquefaction of sewage sludge

    Science.gov (United States)

    Donovan, J. M.; Batter, T. R.; Miller, R. K.; Lottman, R. P.

    1981-10-01

    Direct thermochemical liquefaction of primary undigested municipal sewage sludge was carried out to produce a low molecular weight steam volatile oil, a high molecular weight synthetic asphalt, and a residual char cake. The latter product is capable of supplying the thermal energy requirements of the conversion process. The steam volatile oil has immediate value as a synthetic fuel oil. The synthetic asphalt may prove to be a useful cement for paving or for fuel or coking stock. The thermochemical liquefaction process should be capable of operating technically and in an environmentally acceptable manner in conjunction with many existing waste water treatment facilities. The overall feasibility of the process depends on the value of the oil and synthetic asphalt products as petroleum replacements, and on the costs associated with disposal of sludge.

  13. Synthetic organic chemicals in earthworms from agriculture soil amended with municipal biosolids

    Science.gov (United States)

    Introduction: Biosolids resulting from municipal wastewater treatment are known to contain residues of pharmaceuticals, personal care products (PPCPs) and other synthetic organic compounds. Many of these are contaminants of emerging concern for their potential endocrine disruption of fish and wildli...

  14. On the evaluation of synthetic and natural ilmenite using syngas as fuel in chemical-looping combustion (CLC)

    Energy Technology Data Exchange (ETDEWEB)

    Azis, M.M.; Jerndal, E.; Leion, H.; Mattisson, T.; Lyngfelt, A. [Chalmers, Gothenburg (Sweden)

    2010-11-15

    Chemical-looping combustion (CLC) is a combustion technique where the CO{sub 2} produced is inherently separated from the rest of the flue gases with a considerably low energy penalty. For this reason, CLC has emerged as one of the more attractive options to capture CO{sub 2} from fossil fuel combustion. When applying CLC with solid fuels, the use of a low cost oxygen carrier is highly important, and one such low cost oxygen carrier is the mineral ilmenite. The current work investigates the reactivity of several ilmenites, some which are synthetically produced by freeze granulation and two natural minerals, one Norwegian ilmenite and one South African ilmenite. A laboratory fluidized bed reactor made of quartz was used to simulate a two reactor CLC system by alternating the reduction and oxidation phase. The fuel was syngas containing 50% CO and 50% H{sub 2}. A mixture of 6g of ilmenite with 9 g inert quartz of diameter 125-180 {mu} m was exposed to a flow of 900mL{sup n}/min syngas in the reduction phase. During the oxidation phase, a 900mL/{sub n}min flow of 10% O{sub 2} diluted in N{sub 2} was used. The experimental results showed that all ilmenites give higher conversion of H{sub 2} than of CO. Generally, synthetic ilmenites have better CO and H{sub 2} conversion than natural ilmenites and synthetic ilmenites prepared with an excess of Fe generally showed higher total conversion of CO than synthetic ilmenites with an excess of Ti. Most synthetic ilmenites and the Norwegian ilmenite showed good fluidization properties during the experiments. However, for two of the synthetically produced materials, and for the South African ilmenite, particle agglomerations were visible at the end of the experiment.

  15. Investigations of the Effects of Synthetic Chemicals on the Endocrine System of Common Carp in Lake Mead, Nevada and Arizona

    Science.gov (United States)

    Rosen, Michael R.; Goodbred, Steven L.; Patiño, Reynaldo; Leiker, Thomas A.; Orsak, Erik

    2006-01-01

    Introduction: Lake Mead is the largest reservoir by volume in the United States and was created by the construction of the 221-meter high Hoover Dam in 1935 at Black Canyon on the lower Colorado River between Nevada and Arizona (fig. 1). Inflows of water into the lake include three rivers, Colorado, Virgin, and Muddy; as well as Las Vegas Wash, which is now perennial because of discharges from municipal wastewater treatment plants (Covay and Leiker, 1998) and urban stormwater runoff. As the population within the Las Vegas Valley began to increase in the 1940s, the treated effluent volume also has increased and in 1993 it constituted about 96 percent of the annual discharge of Las Vegas Wash (Bevans and others, 1996). The mean flow of Las Vegas Wash into Las Vegas Bay from 1992 to 1998 was about 490,000 m3/d (Preissler and others, 1999) and in 2001 increased to 606,000 m3/d (U.S. Bureau of Reclamation, 2001). The nutrient concentration in most areas of the lake is low, but wastewater discharged into Las Vegas Bay has caused an increased level of nutrients and primary productivity (aquatic plant and algal production) in this area of the lake (LaBounty and Horn, 1997). A byproduct of this increase in productivity has been the establishment of an important recreational fishery in Las Vegas Bay. However, concentrations of chlorophyll a (a measure of algal biomass) have also increased (LaBounty and Horn, 1997). In the spring of 2001, parts of Lake Mead experienced massive algal blooms. In addition to nutrient loading by wastewater, the presence of numerous synthetic chemicals in water, bottom sediments, and in fish tissue also has been reported (Bevans and others, 1996). Synthetic chemicals discharging into Las Vegas Bay and Lake Mead (fig. 1) originate from several sources that include surplus residential-irrigation water runoff, stormwater runoff, subsurface inflow, and tertiary treated sewage effluent discharging from three sewage-treatment plants. Chemicals detected

  16. Chemical and Physical Analysis Methods for Characterizing Tire Crumb Rubber Used in Synthetic Turf Fields

    Science.gov (United States)

    Tire crumb rubber from recycled tires is widely used as infill material in synthetic turf fields in the United States. Recycled crumb rubber is a complex and potentially variable matrix with many metal, VOC, and SVOC constituents, presenting challenges for characterization and ex...

  17. SALE, Quality Control of Analytical Chemical Measurements

    International Nuclear Information System (INIS)

    Bush, W.J.; Gentillon, C.D.

    1985-01-01

    1 - Description of problem or function: The Safeguards Analytical Laboratory Evaluation (SALE) program is a statistical analysis program written to analyze the data received from laboratories participating in the SALE quality control and evaluation program. The system is aimed at identifying and reducing analytical chemical measurement errors. Samples of well-characterized materials are distributed to laboratory participants at periodic intervals for determination of uranium or plutonium concentration and isotopic distributions. The results of these determinations are statistically evaluated and participants are informed of the accuracy and precision of their results. 2 - Method of solution: Various statistical techniques produce the SALE output. Assuming an unbalanced nested design, an analysis of variance is performed, resulting in a test of significance for time and analyst effects. A trend test is performed. Both within- laboratory and between-laboratory standard deviations are calculated. 3 - Restrictions on the complexity of the problem: Up to 1500 pieces of data for each nuclear material sampled by a maximum of 75 laboratories may be analyzed

  18. Elastohydrodynamic film thickness formula based on X-ray measurements with a synthetic paraffinic oil

    Science.gov (United States)

    Loewenthal, S. H.; Parker, R. J.; Zaretsky, E. V.

    1973-01-01

    An empirical elastohydrodynamic film thickness formula for heavily loaded contacts based upon X-ray film thickness measurements made with a synthetic paraffinic oil is presented. The deduced relation was found to adequately reflect the high load dependence exhibited by the measured minimum film thickness data at high Hertizian contact stresses, that is, above 1.04 x 10 to the ninth N/sq m (150,000 psi). Comparisons were made with the numerical results from a theoretical isothermal film thickness formula. The effects of changes in contact geometry, material, and lubricant properties on the form of the empirical model are also discussed.

  19. Correction of motion measurement errors beyond the range resolution of a synthetic aperture radar

    Science.gov (United States)

    Doerry, Armin W [Albuquerque, NM; Heard, Freddie E [Albuquerque, NM; Cordaro, J Thomas [Albuquerque, NM

    2008-06-24

    Motion measurement errors that extend beyond the range resolution of a synthetic aperture radar (SAR) can be corrected by effectively decreasing the range resolution of the SAR in order to permit measurement of the error. Range profiles can be compared across the slow-time dimension of the input data in order to estimate the error. Once the error has been determined, appropriate frequency and phase correction can be applied to the uncompressed input data, after which range and azimuth compression can be performed to produce a desired SAR image.

  20. 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

  1. Measurement of 238U and 232Th radionuclides in ilmenite and synthetic rutile

    Science.gov (United States)

    Idris, M. I.; Siong, K. K.; Fadzil, S. M.

    2018-01-01

    The only factory that currently processes ilmenite to produce synthetic rutile is Tor Minerals in Ipoh, Perak, Malaysia. These two minerals contain radioactive elements such as uranium and thorium. Furthermore, this factory was built close to the residential areas. Thus, the primary issues are radiation exposure attributed to the decay of the radionuclides. Hence, the objectives of this study are to measure the dose and to evaluate activity levels of uranium and thorium. Dose rates from surrounding area of factory indicate the normal range for both on the surface and 1 meter above the ground (0.3-0.7 μSv/hr) lower than the global range of 0.5-1.3 μSv/hr set by UNSCEAR. The mean activity levels of uranium and thorium for ilmenite are 235 Bq/kg and 503 Bq/kg while for synthetic rutile are 980 Bq/kg and 401 Bq/kg, respectively. The result shows that uranium activity levels of synthetic rutile is 4 times higher than ilmenite but it is still lower than the regulatory exemption limit of 1000 Bq/kg set by IAEA Basic Safety Standards. Even though the dose rates at the factory and the activity levels are within safe limits, safety precautions must be followed by the factory management to prevent any unwanted accident to occur.

  2. Chemical protein synthesis: Inventing synthetic methods to decipher how proteins work.

    Science.gov (United States)

    Kent, Stephen

    2017-09-15

    Total chemical synthesis of proteins has been rendered practical by the chemical ligation principle: chemoselective condensation of unprotected peptide segments equipped with unique, mutually reactive functional groups, enabled by formation of a non-native replacement for the peptide bond. Ligation chemistries are briefly described, including native chemical ligation - thioester-mediated, amide-forming reaction at Xaa-Cys sites - and its extensions. Case studies from the author's own works are used to illustrate the utility and applications of chemical protein synthesis. Selected recent developments in the field are briefly discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Comparison of the chemical reactivity of synthetic peroxynitrite with that of the autoxidation products of nitroxyl or its anion.

    Science.gov (United States)

    Jorolan, Joel H; Buttitta, Lisa Ann; Cheah, Cheryl; Miranda, Katrina M

    2015-01-30

    Donors of nitroxyl (HNO) exhibit pharmacological properties that are potentially favorable for treatment of a variety of diseases. To fully evaluate the pharmacological utility of HNO, it is therefore important to understand its chemistry, particularly involvement in deleterious biological reactions. Of particular note is the cytotoxic species formed from HNO autoxidation that is capable of inducing double strand DNA breaks. The identity of this species remains elusive, but a conceivable product is peroxynitrous acid. However, chemical comparison studies have demonstrated that HNO autoxidation leads to a unique reactive nitrogen oxide species to that of synthetic peroxynitrite. Here, we extend the analysis to include a new preparation of peroxynitrite formed via autoxidation of nitroxyl anion (NO(-)). Both peroxynitrite preparations exhibited similar chemical profiles, although autoxidation of NO(-) provided a more reliable sample of peroxynitrite. Furthermore, the observed dissimilarities to the HNO donor Angeli's salt substantiate that HNO autoxidation produces a unique intermediate from peroxynitrite. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Attraction and antennal response of the common wasp, Vespula vulgaris (L.), to selected synthetic chemicals in New Zealand beech forests.

    Science.gov (United States)

    El-Sayed, Ashraf M; Manning, Lee-Anne; Unelius, C Rikard; Park, Kye Chung; Stringer, Lloyd D; White, Nicola; Bunn, Barry; Twidle, Andrew; Suckling, David M

    2009-09-01

    The common wasp, Vespula vulgaris (L.), and the German wasp, Vespula germanica (F.), are significant problems in New Zealand beech forests (Nothofagus spp.), adversely affecting native birds and invertebrate biodiversity. This work was undertaken to develop synthetic attractants for these species to enable more efficient monitoring and management. Seven known wasp attractants (acetic acid, butyl butyrate, isobutanol, heptyl butyrate, octyl butyrate and 2,4-hexadienyl butyrate) were field tested, and only heptyl butyrate and octyl butyrate attracted significantly higher numbers of wasps than a non-baited trap. Accordingly, a series of straight-chain esters from methyl to decyl butyrate were prepared and field tested for attraction of social wasps. Peak biological activity occurred with hexyl butyrate, heptyl butyrate, octyl butyrate and nonyl butyrate. Polyethylene bags emitting approximately 18.4-22.6 mg day(-1) of heptyl butyrate were more attractive than polyethylene bags emitting approximately 14.7-16.8 mg day(-1) of heptyl butyrate in the field. Electroantennogram (EAG) studies indicated that queens and workers of V. vulgaris had olfactory receptor neurons responding to various aliphatic butyrates. These results are the first to be reported on the EAG response and the attraction of social wasps to synthetic chemicals in New Zealand beech forests and will enable monitoring of social wasp activity in beech forests. Copyright 2009 Society of Chemical Industry.

  5. Synthetic biology and occupational risk.

    Science.gov (United States)

    Howard, John; Murashov, Vladimir; Schulte, Paul

    2017-03-01

    Synthetic biology is an emerging interdisciplinary field of biotechnology that involves applying the principles of engineering and chemical design to biological systems. Biosafety professionals have done an excellent job in addressing research laboratory safety as synthetic biology and gene editing have emerged from the larger field of biotechnology. Despite these efforts, risks posed by synthetic biology are of increasing concern as research procedures scale up to industrial processes in the larger bioeconomy. A greater number and variety of workers will be exposed to commercial synthetic biology risks in the future, including risks to a variety of workers from the use of lentiviral vectors as gene transfer devices. There is a need to review and enhance current protection measures in the field of synthetic biology, whether in experimental laboratories where new advances are being researched, in health care settings where treatments using viral vectors as gene delivery systems are increasingly being used, or in the industrial bioeconomy. Enhanced worker protection measures should include increased injury and illness surveillance of the synthetic biology workforce; proactive risk assessment and management of synthetic biology products; research on the relative effectiveness of extrinsic and intrinsic biocontainment methods; specific safety guidance for synthetic biology industrial processes; determination of appropriate medical mitigation measures for lentiviral vector exposure incidents; and greater awareness and involvement in synthetic biology safety by the general occupational safety and health community as well as by government occupational safety and health research and regulatory agencies.

  6. Cerium oxide for the destruction of chemical warfare agents: A comparison of synthetic routes

    International Nuclear Information System (INIS)

    Janoš, Pavel; Henych, Jiří; Pelant, Ondřej; Pilařová, Věra; Vrtoch, Luboš; Kormunda, Martin; Mazanec, Karel

    2016-01-01

    Highlights: • Four synthetic routes were compared to prepare the nanoceria-based reactive sorbents. • The sorbents prepared by homogeneous hydrolysis destroy efficiently the soman and VX nerve agents. • Toxic organophosphates are converted to less-dangerous products completely within a few minutes. • Surface non-stoichiometry and −OH groups promote the destruction by the S N 2 mechanism. - Abstract: Four different synthetic routes were used to prepare active forms of cerium oxide that are capable of destroying toxic organophosphates: a sol–gel process (via a citrate precursor), homogeneous hydrolysis and a precipitation/calcination procedure (via carbonate and oxalate precursors). The samples prepared via homogeneous hydrolysis with urea and the samples prepared via precipitation with ammonium bicarbonate (with subsequent calcination at 500 °C in both cases) exhibited the highest degradation efficiencies towards the extremely dangerous nerve agents soman (O-pinacolyl methylphosphonofluoridate) and VX (O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate) and the organophosphate pesticide parathion methyl. These samples were able to destroy more than 90% of the toxic compounds in less than 10 min. The high degradation efficiency of cerium oxide is related to its complex surface chemistry (presence of surface −OH groups and surface non-stoichiometry) and to its nanocrystalline nature, which promotes the formation of crystal defects on which the decomposition of organophosphates proceeds through a nucleophilic substitution mechanism that is not dissimilar to the mechanism of enzymatic hydrolysis of organic phosphates by phosphotriesterase.

  7. Cerium oxide for the destruction of chemical warfare agents: A comparison of synthetic routes

    Czech Academy of Sciences Publication Activity Database

    Janos, P.; Henych, Jiří; Pelant, O.; Pilařová, V.; Vrtoch, L.; Kormunda, M.; Mazanec, K.; Štengl, Václav

    2016-01-01

    Roč. 304, MAR (2016), s. 259-268 ISSN 0304-3894 Institutional support: RVO:61388980 Keywords : Cerium oxide * Chemical warfare agents * Organophosphate compounds * Decontamination Subject RIV: CA - Inorganic Chemistry Impact factor: 6.065, year: 2016

  8. Comparison of Chemical Coagulation and Electrocoagulation for Boron Removal from Synthetic Wastewater Using Aluminium

    OpenAIRE

    Kartikaningsih Danis; Yao-Hui Huang

    2016-01-01

    Various techniques including conventional and advanced have been employed for the boron treatment from water and wastewater. The electrocoagulation involves an electrolytic reactor for coagulation/flotation with aluminium as anode and cathode. There is aluminium as coagulant to be used for removal which may induce secondary pollution in chemical coagulation. The purpose of this study is to investigate and compare the performance between electrocoagulation and chemical coagulation on boron rem...

  9. Chemical Microsensor Instrument for UAV Airborne Atmospheric Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Makel Engineering, Inc. (MEI) proposes to develop a miniaturized Airborne Chemical Microsensor Instrument (ACMI) suitable for real-time, airborne measurements of...

  10. Accurate measurements of the acoustical physical constants of synthetic alpha-quartz for SAW devices.

    Science.gov (United States)

    Kushibiki, Juin-ichi; Takanaga, Izumi; Nishiyama, Shouichi

    2002-01-01

    Accurate measurements of the acoustical physical constants (elastic constants, piezoelectric constants, dielectric constants, and density) of commercially available and widely used surface acoustic wave (SAW)-grade synthetic a-quartz are reported. The propagation directions and modes of bulk waves optimal for accurately determining the constants were selected through numerical calculations, and three principal X-, Y-, and Z-cut specimens and several rotated Y-cut specimens were prepared from a single crystal ingot to determine the constants and to confirm their accuracy. All of the constants were determined through highly accurate measurements of the longitudinal velocities, shear velocities, dielectric constants, and density. The velocity values measured for the specimens that were not used to determine the constants agreed well with those calculated from the determined constants, within a difference of +/- 0.20 m/s (+/- 0.004%).

  11. Fluxes of chemically reactive species inferred from mean concentration measurements

    NARCIS (Netherlands)

    Galmarini, S.; Vilà-Guerau De Arellano, J.; Duyzer, J.H.

    1997-01-01

    A method is presented for the calculation of the fluxes of chemically reactive species on the basis of routine measurements of meteorological variables and chemical species. The method takes explicity into account the influence of chemical reactions on the fluxes of the species. As a demonstration

  12. Chemical composition of natural colophony from Pinus brutia and comparison with synthetic colophony.

    Science.gov (United States)

    Gören, Ahmet C; Bilsel, Gökhan; Oztürk, Alp Hakan; Topçu, Gülaçti

    2010-11-01

    The compositions of colophony resins obtained from Pinus brutia Ten trees by three different methods (acid paste, carved hole and scraping) from Ayvacik, Gökova and Kemalpaşa in Turkey were analyzed by capillary GC-MS. The main components were the monoterpenes alpha-pinene, beta-pinene, and delta3-carene, and the diterpenic resin acids palustric, abietic, kaur-9(11)-16-en-18-oic and neoabietic acid. The synthetic colophony resins exhibited similar contents to those of the natural resins obtained from the Gökova and Kemalpaşa regions of Turkey. However, colophony resins from Ayvacik exhibited only half the diterpenic acid content as those of the Gökova and Kemalpaşa resins. Out of the three techniques, the carved hole method caused rather different percentages in the constituents of the essential oils.

  13. 1,5-Dimethylhexylamine (octodrine) in sports and weight loss supplements: Natural constituent or synthetic chemical?

    Science.gov (United States)

    Wang, Mei; Haider, Saqlain; Chittiboyina, Amar G; Parcher, Jon F; Khan, Ikhlas A

    2018-04-15

    In the past years, there has been a mounting trend toward the addition of sympathomimetic stimulants in sports and weight loss supplements sold in the US and claimed to be from natural constituents. The latest among those pharmaceutical stimulants is 1,5-dimethylhexylamine (1,5-DMHA or octodrine), an ingredient in newly introduced sports and weight loss supplements with its 'natural' origin being cited from Aconitum or Kigelia plants. In order to validate the natural existence of 1,5-DMHA, two GC/MS methods were developed. One method involved using thick film megabore capillary columns to analyze the underivatized 1,5-DMHA. The second method was to determine enantiomeric distribution of 1,5-DMHA. Fifteen Aconitum or Kigelia plant samples originating from various locations were analyzed, and none of them contained 1,5-DMHA within the limit of detection (25 ng/mL) of the method. In contrast, although 1,5-DMHA was listed on the labels or website for all the 13 dietary supplements, only four products were found to contain this compound, with the highest quantity being reported as 112 mg per serving size. This is equivalent to more than three times the highest pharmaceutical dose established in Europe. The enantiomeric ratios of 1,5-DMHA in these products were determined to be between 0.9-1.0 (expressed as peak area ratio of one enantiomer over another), suggesting racemic nature. Interestingly, two byproducts from 1,5-DMHA synthesis were identified in commercial supplements containing 1,5-DMHA, indicating that 1,5-DMHA indeed originated from a poor quality source. Overall, the significant amount of 1,5-DMHA observed in the supplements, the enantiomeric distribution and the presence of the synthetic byproducts all suggested the synthetic origin of 1,5-DMHA in the commercial products. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. WORKSHOP ON NEW DEVELOPMENTS IN CHEMICAL SEPARATIONS FROM COMBINATORIAL CHEMISTRY AND RELATED SYNTHETIC STRATEGIES

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Stephen G. [University of Pittsburgh, Pittsburgh, Pennsylvania

    1998-08-22

    The power of combinatorial chemistry and related high throughput synthetic strategies is currently being pursued as a fruitful way to develop molecules and materials with new properties. The strategy is motivated, for example in the pharmaceutical industry, by the difficulty of designing molecules to bind to specific sites on target biomolecules. By synthesizing a variety of similar structures, and then finding the one that has the most potent activity, new so-called lead structures will be found rapidly. Existing lead structures can be optimized. This relatively new approach has many implications for separation science. The most obvious is the call for more separations power: higher resolution, lower concentrations, higher speed. This pressure butresses the traditional directions of research into the development of more useful separations. The advent of chip-based, electroosmotically pumped systems1 will certainly accelerate progress in this traditional direction. The progress in combinatorial chemistry and related synthetic strategies gives rise to two other, broadly significant possibilities for large changes in separation science. One possibility results from the unique requirements of the synthesis of a huge number of products simultaneously. Can syntheses and separations be designed to work together to create strategies that lead to mixtures containing only desired products but without side products? The other possibility results from the need for molecular selectivity in separations. Can combinatorial syntheses and related strategies be used in the development of better separations media? A workshop in two parts was held. In one half-day session, pedagogical presentations educated across the barriers of discipline and scale. In the second half-day session, the participants broke into small groups to flesh out new ideas. A panel summarized the breakout discussions.

  15. Synthetic surface for expansion of human mesenchymal stem cells in xeno-free, chemically defined culture conditions.

    Directory of Open Access Journals (Sweden)

    Paula J Dolley-Sonneville

    Full Text Available Human mesenchymal stem cells (HMSCS possess three properties of great interest for the development of cell therapies and tissue engineering: multilineage differentiation, immunomodulation, and production of trophic factors. Efficient ex vivo expansion of hMSCs is a challenging requirement for large scale production of clinical grade cells. Low-cost, robust, scalable culture methods using chemically defined materials need to be developed to address this need. This study describes the use of a xeno-free synthetic peptide acrylate surface, the Corning® Synthemax® Surface, for culture of hMSCs in serum-free, defined medium. Cell performance on the Corning Synthemax Surface was compared to cells cultured on biological extracellular matrix (ECM coatings in xeno-free defined medium and in traditional conditions on tissue culture treated (TCT plastic in fetal bovine serum (FBS supplemented medium. Our results show successful maintenance of hMSCs on Corning Synthemax Surface for eight passages, with cell expansion rate comparable to cells cultured on ECM and significantly higher than for cells in TCT/FBS condition. Importantly, on the Corning Synthemax Surface, cells maintained elongated, spindle-like morphology, typical hMSC marker profile and in vitro multilineage differentiation potential. We believe the Corning Synthemax Surface, in combination with defined media, provides a complete synthetic, xeno-free, cell culture system for scalable production of hMSCs.

  16. Novel synthetic approach to the prion protein: Kinetic study optimization of a native chemical ligation

    Czech Academy of Sciences Publication Activity Database

    Zawada, Zbigniew; Šebestík, Jaroslav; Bouř, Petr; Hlaváček, Jan; Stibor, Ivan

    2008-01-01

    Roč. 14, č. 8 (2008), s. 76-77 ISSN 1075-2617. [European Peptide Symposium /30./. 31.08.2008-05.09.2008, Helsinki] R&D Projects: GA ČR GA203/07/1517 Institutional research plan: CEZ:AV0Z40550506 Keywords : prion protein * neurodegenerative diseases * chemical synthesis * ligation conditions Subject RIV: CC - Organic Chemistry

  17. Synthetic study on prion protein fragments using a SPPS and native chemical ligation

    Czech Academy of Sciences Publication Activity Database

    Zawada, Z.; Šebestík, Jaroslav; Bednárová, Lucie; Bouř, Petr; Hlaváček, Jan; Stibor, Ivan

    2009-01-01

    Roč. 37, Suppl. 1 (2009), s. 44-44 ISSN 0939-4451. [International Congress on Amino Acids, Peptides and Proteins /11./. 03.08.2009-07.08.2009, Vienna] Institutional research plan: CEZ:AV0Z40550506 Keywords : prion protein * SPPS * native chemical ligation * fragments Subject RIV: CC - Organic Chemistry

  18. Dissolution of synthetic uranium dibutyl phosphate deposits in oxidizing and reducing chemical formulations

    Energy Technology Data Exchange (ETDEWEB)

    Rufus, A.L.; Sathyaseelan, V.S.; Narasimhan, S.V.; Velmurugan, S., E-mail: svelu@igcar.gov.in

    2013-06-15

    Graphical abstract: SEM of the U-DBP coated stainless steel coupon before and after exposure to chemical formulation containing acid permanganate at 80 °C. -- Highlights: •Combination of oxidation and reduction processes efficiently dissolves U-DBP deposits. •NP and NAC formulations are compatible with SS-304. •Dissolved uranium and added chemicals are effectively removed via ion exchangers. -- Abstract: Permanganate and nitrilotriacetic acid (NTA) based dilute chemical formulations were evaluated for the dissolution of uranium dibutyl phosphate (U-DBP), a compound that deposits over the surfaces of nuclear reprocessing plants and waste storage tanks. A combination of an acidic, oxidizing treatment (nitric acid with permanganate) followed by reducing treatment (NTA based formulation) efficiently dissolved the U-DBP deposits. The dissolution isotherm of U-DBP in its as precipitated form followed a logarithmic fit. The same chemical treatment was also effective in dissolving U-DBP coated on the surface of 304-stainless steel, while resulting in minimal corrosion of the stainless steel substrate material. Investigation of uranium recovery from the resulting decontamination solutions by ion exchange with a bed of mixed anion and cation resins showed quantitative removal of uranium.

  19. PROMYS – Programming synthetic networks for bio-based production of value chemicals – FP7 project

    DEFF Research Database (Denmark)

    Sommer, Morten Otto Alexander

    2017-01-01

    The global chemical industry is transitioning from petrochemical production processes to bio-based production processes. This transition creates a clear market need for technologies that reduce the development time and cost of cell factories. PROMYS will develop, validate and implement a novel...... synthetic biology platform technology termed ligand responsive regulation and selection systems. Ligand responsive regulation and selection systems are biological devices that integrate biological sensing modules, within larger regulatory networks to control cellular programs. This technology...... will drastically accelerate the construction, optimization and performance of cell factories by enabling industrial users to impose non-natural objectives on the engineered cell factory. PROMYS will address three major challenges in metabolic engineering that limit the development of new cell factories: 1...

  20. Synthetic surfactant containing SP-B and SP-C mimics is superior to single-peptide formulations in rabbits with chemical acute lung injury

    Directory of Open Access Journals (Sweden)

    Frans J. Walther

    2014-05-01

    Full Text Available Background. Chemical spills are on the rise and inhalation of toxic chemicals may induce chemical acute lung injury (ALI/acute respiratory distress syndrome (ARDS. Although the pathophysiology of ALI/ARDS is well understood, the absence of specific antidotes has limited the effectiveness of therapeutic interventions.Objectives. Surfactant inactivation and formation of free radicals are important pathways in (chemical ALI. We tested the potential of lipid mixtures with advanced surfactant protein B and C (SP-B and C mimics to improve oxygenation and lung compliance in rabbits with lavage- and chemical-induced ALI/ARDS.Methods. Ventilated young adult rabbits underwent repeated saline lung lavages or underwent intratracheal instillation of hydrochloric acid to induce ALI/ARDS. After establishment of respiratory failure rabbits were treated with a single intratracheal dose of 100 mg/kg of synthetic surfactant composed of 3% Super Mini-B (S-MB, a SP-B mimic, and/or SP-C33 UCLA, a SP-C mimic, in a lipid mixture (DPPC:POPC:POPG 5:3:2 by weight, the clinical surfactant Infasurf®, a bovine lung lavage extract with SP-B and C, or synthetic lipids alone. End-points consisted of arterial oxygenation, dynamic lung compliance, and protein and lipid content in bronchoalveolar lavage fluid. Potential mechanism of surfactant action for S-MB and SP-C33 UCLA were investigated with captive bubble surfactometry (CBS assays.Results. All three surfactant peptide/lipid mixtures and Infasurf equally lowered the minimum surface tension on CBS, and also improved oxygenation and lung compliance. In both animal models, the two-peptide synthetic surfactant with S-MB and SP-C33 UCLA led to better arterial oxygenation and lung compliance than single peptide synthetic surfactants and Infasurf. Synthetic surfactants and Infasurf improved lung function further in lavage- than in chemical-induced respiratory failure, with the difference probably due to greater capillary

  1. Absolute distance measurement with micrometer accuracy using a Michelson interferometer and the iterative synthetic wavelength principle.

    Science.gov (United States)

    Alzahrani, Khaled; Burton, David; Lilley, Francis; Gdeisat, Munther; Bezombes, Frederic; Qudeisat, Mohammad

    2012-02-27

    We present a novel system that can measure absolute distances of up to 300 mm with an uncertainty of the order of one micrometer, within a timeframe of 40 seconds. The proposed system uses a Michelson interferometer, a tunable laser, a wavelength meter and a computer for analysis. The principle of synthetic wave creation is used in a novel way in that the system employs an initial low precision estimate of the distance, obtained using a triangulation, or time-of-flight, laser system, or similar, and then iterates through a sequence of progressively smaller synthetic wavelengths until it reaches micrometer uncertainties in the determination of the distance. A further novel feature of the system is its use of Fourier transform phase analysis techniques to achieve sub-wavelength accuracy. This method has the major advantages of being relatively simple to realize, offering demonstrated high relative precisions better than 5 × 10(-5). Finally, the fact that this device does not require a continuous line-of-sight to the target as is the case with other configurations offers significant advantages.

  2. Post-Synthetic Anisotropic Wet-Chemical Etching of Colloidal Sodalite ZIF Crystals.

    Science.gov (United States)

    Avci, Civan; Ariñez-Soriano, Javier; Carné-Sánchez, Arnau; Guillerm, Vincent; Carbonell, Carlos; Imaz, Inhar; Maspoch, Daniel

    2015-11-23

    Controlling the shape of metal-organic framework (MOF) crystals is important for understanding their crystallization and useful for myriad applications. However, despite the many advances in shaping of inorganic nanoparticles, post-synthetic shape control of MOFs and, in general, molecular crystals remains embryonic. Herein, we report using a simple wet-chemistry process at room temperature to control the anisotropic etching of colloidal ZIF-8 and ZIF-67 crystals. Our work enables uniform reshaping of these porous materials into unprecedented morphologies, including cubic and tetrahedral crystals, and even hollow boxes, by an acid-base reaction and subsequent sequestration of leached metal ions. Etching tests on these ZIFs reveal that etching occurs preferentially in the crystallographic directions richer in metal-ligand bonds; that, along these directions, the etching rate tends to be faster on the crystal surfaces of higher dimensionality; and that the etching can be modulated by adjusting the pH of the etchant solution. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Consecutive native chemical ligation-route to synthetic mouse prion protein

    Czech Academy of Sciences Publication Activity Database

    Zawada, Zbigniew; Šebestík, Jaroslav; Šafařík, Martin; Březinová, Anna; Bouř, Petr; Hlaváček, Jan; Stibor, Ivan

    2009-01-01

    Roč. 103, č. 11 (2009), s. 1001-1001 ISSN 0009-2770. [Pokroky v organické, bioorganické a farmaceutické chemii /44./. 27.11.2009-29.11.2009, Liblice] R&D Projects: GA ČR GA203/07/1517 Institutional research plan: CEZ:AV0Z40550506 Keywords : prion * chemical ligation Subject RIV: CC - Organic Chemistry

  4. Synthetic cannabinoids: new matrix addiction

    Directory of Open Access Journals (Sweden)

    Antsyborov A.V.

    2017-04-01

    Full Text Available the majority of synthetic cannabinoids (SC, belongs to the group of so-called designer drugs distributed through illegal online shopping. The first reports of this group of psychoactive substances appeared in the 70s of the last century. Today, according to various estimates, there are over 160 varieties of synthetic cannabinoids, and this figure is increasing annually due to the synthesis of new substances in the group. This group of substances is designed to «copy» the psychoactive effects of cannabis. Initially, these substances were created solely for research purposes, to study the endocannabinoid system of the person. Natural THC is a partial agonist of cannabinoid receptors. Synthetic cannabinoids are full agonists CB1R and CB2R types of cannabinoid receptors. Most countries in the world, including Russia, at the legislative level have taken restrictive measures for preventing the spread of this group of substances. In order to circumvent the legislative measures, the producers of synthetic cannabinoids regularly changing the chemical formula. Each year, an increasing number of emergency hospital admissions associated with the use of synthetic cannabinoids in the peer-reviewed literature describes the deaths directly attributable to medical complications after taking synthetic cannabinoids. Numerous studies have proven the possibility of developing psychological dependence due to the use of synthetic cannabinoids. The proposed review of the literature is presented for the purpose of organizing data in the field of synthetic cannabinoids.

  5. Pulse-to-pulse alignment technique based on synthetic-wavelength interferometry of optical frequency combs for distance measurement.

    Science.gov (United States)

    Wu, Guanhao; Takahashi, Mayumi; Inaba, Hajime; Minoshima, Kaoru

    2013-06-15

    A synthetic-wavelength interferometry of optical frequency combs is proposed for the pulse-to-pulse alignment in absolute distance measurement. The synthetic wavelength derived from the virtual second harmonic and the real second harmonic is used to bridge the interference intensity peak-finding method and the heterodyne interferometric phase measurement, so that the pulse-to-pulse alignment can be linked directly to single-wavelength heterodyne interferometry. The experimental results demonstrate that the distance measured by the peak-finding method with micrometer accuracy can be improved to the nanometer level by applying the method proposed.

  6. Comparison of a synthetic chemical lure and standard fermented baits for trapping Drosophila suzukii (Diptera: Drosophilidae).

    Science.gov (United States)

    Cha, Dong H; Hesler, Stephen P; Cowles, Richard S; Vogt, Heidrun; Loeb, Gregory M; Landolt, Peter J

    2013-10-01

    We determined the attractiveness of a new chemical lure compared with fermented food baits in use for trapping Drosophila suzukii Matsumura, spotted wing drosophila (Diptera: Drosophilidae), in Connecticut, New York, and Washington in the United States and at Dossenheim in Germany. The chemical lure (SWD lure) and food baits were compared in two types of traps: the dome trap and a cup trap. Regardless of trap type, numbers of male and female D. suzukii trapped were greater with the SWD lure compared with apple cider vinegar (ACV) baits at the Washington and New York sites, and were comparable with numbers of D. suzukii captured with a wine plus vinegar bait (W + V) at Germany site and a combination bait meant to mimic W + V at the Connecticut site. Averaged over both types of attractants, the numbers of D. suzukii captured were greater in dome traps than in cup traps in New York and Connecticut for both male and female D. suzukii and in Washington for male D. suzukii. No such differences were found between trap types at the Washington site for female and Germany for male and female D. suzukii. Assessments were also made of the number of large (>0.5 cm) and small (attractant for D. suzukii and could be used in place of fermented food-type baits.

  7. Interactions between structural and chemical biomimetism in synthetic stem cell niches.

    Science.gov (United States)

    Nava, Michele M; Raimondi, Manuela T; Credi, Caterina; De Marco, Carmela; Turri, Stefano; Cerullo, Giulio; Osellame, Roberto

    2015-01-16

    Advancements in understanding stem cell functions and differentiation are of key importance for the clinical success of stem-cell-based therapies. 3D structural niches fabricated by two-photon polymerization are a powerful platform for controlling stem cell growth and differentiation. In this paper, we investigate the possibility of further controlling stem cell fate by tuning the mechanical properties of such niches through coating with thin layers of biomimetic hyaluronan-based and gelatin-based hydrogels. We first assess the biocompatibility of chemical coatings and then study the interactions between structural and chemical biomimetism on the response of MSCs in terms of proliferation and differentiation. We observed a clear effect of the hydrogel coating on otherwise identical 3D scaffolds. In particular, in gelatin-coated niches we observed a stronger metabolic activity and commitment toward the osteo-chondral lineage with respect to hyaluronan-coated niches. Conversely, a reduction in the homing effect was observed in all the coated niches, especially in gelatin-coated niches. This study demonstrates the feasibility of controlling independently different mechanical cues, in bioengineered stem cell niches, i.e. the 3D scaffold geometry and the surface stiffness. This will allow, on the one hand, understanding their specific role in stem cell proliferation and differentiation and, on the other hand, finely tuning their synergistic effect.

  8. Kinetic measurements and quantum chemical calculations on low ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 127; Issue 7. Kinetic measurements and quantum chemical calculations on low spin Ni(II)/(III) macrocyclic complexes in aqueous and sulphato medium. Anuradha Sankaran E J Padma Malar Venkatapuram Ramanujam Vijayaraghavan. Regular Articles Volume 127 ...

  9. Raising awareness of new psychoactive substances: chemical analysis and in vitro toxicity screening of 'legal high' packages containing synthetic cathinones.

    Science.gov (United States)

    Araújo, Ana Margarida; Valente, Maria João; Carvalho, Márcia; Dias da Silva, Diana; Gaspar, Helena; Carvalho, Félix; de Lourdes Bastos, Maria; Guedes de Pinho, Paula

    2015-05-01

    The world's status quo on recreational drugs has dramatically changed in recent years due to the rapid emergence of new psychoactive substances (NPS), represented by new narcotic or psychotropic drugs, in pure form or in preparation, which are not controlled by international conventions, but that may pose a public health threat comparable with that posed by substances listed in these conventions. These NPS, also known as 'legal highs' or 'smart drugs', are typically sold via Internet or 'smartshops' as legal alternatives to controlled substances, being announced as 'bath salts' and 'plant feeders' and is often sought after for consumption especially among young people. Although NPS have the biased reputation of being safe, the vast majority has hitherto not been tested and several fatal cases have been reported, namely for synthetic cathinones, with pathological patterns comparable with amphetamines. Additionally, the unprecedented speed of appearance and distribution of the NPS worldwide brings technical difficulties in the development of analytical procedures and risk assessment in real time. In this study, 27 products commercialized as 'plant feeders' were chemically characterized by gas chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy. It was also evaluated, for the first time, the in vitro hepatotoxic effects of individual synthetic cathinones, namely methylone, pentedrone, 4-methylethcathinone (4-MEC) and 3,4-methylenedioxypyrovalerone (MDPV). Two commercial mixtures ('Bloom' and 'Blow') containing mainly cathinone derivatives were also tested, and 3,4-methylenedioxymethamphetamine (MDMA) was used as the reference drug. The study allowed the identification of 19 compounds, showing that synthetic cathinones are the main active compounds present in these products. Qualitative and quantitative variability was found in products sold with the same trade name in matching or different 'smartshops'. In the toxicity studies performed in

  10. Hazardous air pollutant emissions from process units in the synthetic organic chemical manufacturing industry: Background information for proposed standards. Volume 1A. National impacts assessment. Draft report

    International Nuclear Information System (INIS)

    1992-11-01

    A draft rule for the regulation of emissions of organic hazardous air pollutants (HAP's) from chemical processes of the synthetic organic chemical manufacturing industry (SOCMI) is being proposed under the authority of Sections 112, 114, 116, and 301 of the Clean Air Act, as amended in 1990. The volume of the Background Information Document presents the results of the national impacts assessment for the proposed rule

  11. Hazardous air pollutant emissions from process units in the synthetic organic chemical manufacturing industry: Background information for proposed standards. Volume 1B. Control technologies. Draft report

    International Nuclear Information System (INIS)

    1992-11-01

    A draft rule for the regulation of emissions of organic hazardous air pollutants (HAP's) from chemical processes of the synthetic organic chemical manufacturing industry (SOCMI) is being proposed under the authority of Sections 112, 114, 116, and 301 of the Clean Air Act, as amended in 1990. The volume of the Background Information Document presents discussions of control technologies used in the industry and the costs of those technologies

  12. 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...

  13. Qualitative/Chemical Analyses of Ankaferd Hemostat and Its Antioxidant Content in Synthetic Gastric Fluids

    Directory of Open Access Journals (Sweden)

    Ahmet Koluman

    2016-01-01

    Full Text Available Introduction. Ankaferd hemostat (ABS is the first topical haemostatic agent involving the red blood cell-fibrinogen interactions. The antihemorrhagic efficacy of ABS has been tested in controlled clinical trials. The drug induces the formation of an encapsulated complex protein web with vital erythroid aggregation. The aim of this study is to detect the essential toxicity profile and the antioxidant molecules inside ABS. Methods. The pesticides were analyzed by GC-MS and LC-MS. The determination by ICP-MS after pressure digestion was performed for the heavy metals. HPLC was used for the detection of mycotoxins. Dioxin Response Chemically Activated Luciferase Gene Expression method was used for the dioxin evaluation. TOF-MS and spectra data were evaluated to detect the antioxidants and other molecules. Results. TOF-MS spectra revealed the presence of several antioxidant molecules (including tocotrienols, vitamin E, tryptophan, estriol, galangin, apigenin, oenin, 3,4-divanillyltetrahydrofuran, TBHQ, thymol, BHA, BHT, lycopene, glycyrrhetinic acid, and tomatine, which may have clinical implications in the pharmacobiological actions of ABS. Conclusion. The safety of ABS regarding the presence of heavy metals, pesticides, mycotoxins, GMO and dioxins, and PCBs was demonstrated. Thus the present toxicological results indicated the safety of ABS. The antioxidant content of ABS should be investigated in future studies.

  14. CHEMICAL AND PHYSICAL PROPERTIES OF THE FORTIFIED WHEAT FLOUR WITH SYNTHETIC FENAEDTA COMPLEX

    Directory of Open Access Journals (Sweden)

    Ali Hussein Abed-Al-Kareem

    2013-08-01

    Full Text Available This study includes fortification of two type of flour 70 and 80 % extraction with two sources of non-haem iron sodium iron EDTA (FeNaEDTA which was synthesis in laboratory and ferrous sulfate in level of 30 mg iron/kg flour. The synthesis FeNaEDTA has been identified in several methods, infra red spectrophotometry, C.H.N analyzer and inductively coupled plasma optical emission spectrometry (ICP- OES. NaFeEDTA is the only non-haem source that has good bioavailability as it is relatively independent of flour composition and withstands the inhibitory effects of phytates. Chemical analysis of the two type of the flour before and after fortification with FeNaEDTA was done (moisture, ash , protein , fat and wet gluten% and the amount of iron as mg/100g.The falling number was not affected by the above fortificants.The values of falling Number of 70% extraction for non-fortified and fortified flour by FeNaEDTA and ferrous sulfate were ( 425,426,427 second respectively, while for 80% extracted flour were (445,446,448 second respectively. The color test showed an increasing of color degree upon fortified by iron sulfate and decreasing of upon fortified by FeNaEDTA in both type of flour.

  15. A large scale analysis of information-theoretic network complexity measures using chemical structures.

    Directory of Open Access Journals (Sweden)

    Matthias Dehmer

    Full Text Available This paper aims to investigate information-theoretic network complexity measures which have already been intensely used in mathematical- and medicinal chemistry including drug design. Numerous such measures have been developed so far but many of them lack a meaningful interpretation, e.g., we want to examine which kind of structural information they detect. Therefore, our main contribution is to shed light on the relatedness between some selected information measures for graphs by performing a large scale analysis using chemical networks. Starting from several sets containing real and synthetic chemical structures represented by graphs, we study the relatedness between a classical (partition-based complexity measure called the topological information content of a graph and some others inferred by a different paradigm leading to partition-independent measures. Moreover, we evaluate the uniqueness of network complexity measures numerically. Generally, a high uniqueness is an important and desirable property when designing novel topological descriptors having the potential to be applied to large chemical databases.

  16. An infrared measurement of chemical desorption from interstellar ice analogues

    Science.gov (United States)

    Oba, Y.; Tomaru, T.; Lamberts, T.; Kouchi, A.; Watanabe, N.

    2018-03-01

    In molecular clouds at temperatures as low as 10 K, all species except hydrogen and helium should be locked in the heterogeneous ice on dust grain surfaces. Nevertheless, astronomical observations have detected over 150 different species in the gas phase in these clouds. The mechanism by which molecules are released from the dust surface below thermal desorption temperatures to be detectable in the gas phase is crucial for understanding the chemical evolution in such cold clouds. Chemical desorption, caused by the excess energy of an exothermic reaction, was first proposed as a key molecular release mechanism almost 50 years ago1. Chemical desorption can, in principle, take place at any temperature, even below the thermal desorption temperature. Therefore, astrochemical network models commonly include this process2,3. Although there have been a few previous experimental efforts4-6, no infrared measurement of the surface (which has a strong advantage to quantify chemical desorption) has been performed. Here, we report the first infrared in situ measurement of chemical desorption during the reactions H + H2S → HS + H2 (reaction 1) and HS + H → H2S (reaction 2), which are key to interstellar sulphur chemistry2,3. The present study clearly demonstrates that chemical desorption is a more efficient process for releasing H2S into the gas phase than was previously believed. The obtained effective cross-section for chemical desorption indicates that the chemical desorption rate exceeds the photodesorption rate in typical interstellar environments.

  17. Quantification of synthetic organic chemicals in biological treatment process effluent using solid-phase microextraction and gas chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Magbanua, B.S. Jr.; Mitchell, D.R.; Fehniger, S.M.; Bowyer, R.L.; Grady, C.P.L. Jr.

    2000-02-01

    Solid-phase microextraction (SPME), a technique that uses a polymer-coated, fused-silica fiber to selectively extract organic analyses from a sample matrix, followed by gas chromatography (GC), was used to quantify selected synthetic organic chemicals (SOCs) in biological reactor effluent. By selecting an appropriate combination of SPME fiber, GC column, and GC detector, assays to quantify either a suite of SOCs or single selected SOCs were developed. Phenol, 4-chlorophenol, 2-nitrophenol, 4-nitrophenol, 2,4,-dinitrophenol, isophorone, m-toluate, m-sylene, and di-n-butylphthalate were quantified simultaneously using an 85-{micro}m polyacrylate SPME fiber, a 5% diphenyl-95% dimethyl polysiloxane capillary column, and a flame ionization detector. m-Xylene was quantified using a 100-{micro}m polydimethylsiloxane SPME fiber, a 5% diphenyl-95% dimethyl polysiloxane capillary column, and a mass spectrometric detector. Dichloromethane was quantified using an 85-{micro}m polyacrylate SPME fiber, a Carbopack B/1% SP-1000 packed column, and an electron capture detector. All three assays enabled detection of the target analyses to low concentrations ({micro}g/L) with minimal sample volume and processing requirements.

  18. Sensory and chemical stability in coated peanuts with the addition of essential oils and synthetic antioxidants

    Directory of Open Access Journals (Sweden)

    Olmedo, R. H.

    2012-03-01

    Full Text Available The objective of this work was to evaluate the antioxidant effect of essential oils on the oxidative stability of coated peanuts. Untreated coated peanuts (CP and treated coated peanuts with the addition of rosemary (CP-R, oregano (CP-O and laurel (CP-L essential oils and BHT (CPBHT were prepared. Peroxide values (PV and p-anisidine values (AV and the intensity ratings of sensory attributes by descriptive analysis were measured during 112 days of storage at room temperature (23°C. CP-BHT exhibited the lowest PV and AV increase. CP-R, CP-O and CP-L showed lower rates of increase in PV and AV than CP. The oxidized and cardboard flavor intensity ratings increased much more in CP during storage than the other studied products. CPBHT also showed the lowest increase in the intensity ratings of these sensory attributes. Three essential oils, namely, laurel, oregano and rosemary showed antioxidant activity and increased the shelf life of coated peanuts.

    El objetivo de este trabajo fue evaluar el efecto antioxidante de aceites esenciales sobre la estabilidad oxidativa en maní recubiertos. Se prepararon maníes recubiertos sin agregados (CP, y con el agregado de aceites esenciales de romero (CP-R, orégano (CP-O y laurel (CP-L y BHT (CPBHT. Se midieron, durante 112 días de almacenamiento, los valores de peróxidos (PV y p-anisidina (AV, y las intensidades de atributos sensoriales mediante análisis descriptivo. CP-BHT presentó el menor valor de PV y AV. CP-R, CP-O y CP-L tuvieron mayor PV y AV respecto a CP. Los valores de intensidad del sabor oxidado y cartón tuvieron un mayor incremento en CP durante el almacenamiento con respecto a los otros productos estudiados. La muestra CP-BHT también mostró los menores valores de intensidad de estos atributos sensoriales. Los aceites esenciales de laurel, orégano y romero presentaron actividad antioxidante e incrementaron la vida útil del maní recubierto.

  19. Chemical application of positron annihilation through triple coincidence measurement

    International Nuclear Information System (INIS)

    Yegnasubramanian, S.; Gangadharan, S.

    1982-01-01

    This report summarises the work on the application of triple coincidence measurement of annihilation radiation for providing chemical state information; the observations have been corroborated by angular correlation and Doppler broadening measurements and supplemented by the magnetic quenching in the angular correlation and peak-to-valley ratio in the Ge(Li) singles spectrum for the 511 keV line. (author)

  20. Measurements of radon and chemical elements: Popocatepetl volcano

    International Nuclear Information System (INIS)

    Pena, P.; Segovia, N.; Lopez, B.; Reyes, A.V.; Armienta, M.A.; Valdes, C.; Mena, M.; Seidel, J.L.; Monnin, M.

    2002-01-01

    The Popocatepetl volcano is a higher risk volcano located at 60 Km from Mexico City. Radon measurements on soil in two fixed seasons located in the north slope of volcano were carried out. Moreover the radon content, major chemical elements and tracks in water samples of three springs was studied. The radon of soil was determined with solid detectors of nuclear tracks (DSTN). The radon in subterranean water was evaluated through the liquid scintillation method and it was corroborated with an Alpha Guard equipment. The major chemical elements were determined with conventional chemical methods and the track elements were measured using an Icp-Ms equipment. The radon on soil levels were lower, indicating a moderate diffusion of the gas across the slope of the volcano. The radon in subterranean water shown few changes in relation with the active scene of the volcano. The major chemical elements and tracks showed a stable behavior during the sampling period. (Author)

  1. [EQA-17: proposing a synthetic indicator to measure the outcomes of primary care teams in people over 14 years].

    Science.gov (United States)

    Vila Córcoles, Angel; Ansa Echevarría, Xabier; Gómez Sorribes, Albert; Fort Sabaté, Joan; Llorens, Jordi Grifoll; Pascual Morón, Ignacio

    2006-01-01

    There are many indicators to measure different aspects of the Primary Health Care activities. However, the interpretation of most of them it is difficult because the majority give partial information. This work proposes a standardised model to calculation of a synthetic indicator to measure the product of primary care teams. We made this work based on the sequential realization of a bibliographical review, a retrospective study to know registered morbidity, and the consent of a working group. For the design of the synthetic indicator we carried out a sequential working methodology in six phases: (1) identification and selection of components for the indicator; (2) determination of theoretical prevalences and coverages; (3) ponderation of the components; (4) establishment of standards; (5) formulation of the components; (6) application of the scale and calculation of the indicator. Ten health problems were selected; that supposed a standardised scale of 17 items (EQA-17). The 10 problems of health which composed this synthetic indicator contemplate the realization of activities of promotion of the health (smoking cessation), activities of primary prevention (tetanus and influenza vaccination), care of acute problems (prescription of antibiotics), and care of chronic diseases (diabetes, chronic obstructive pulmonary disease, hypertension, patients with high-risk cardiovascular index, atrial fibrillation, and heart failure). The concept of a synthetic indicator to measure the level of quality of the product generated by the primary care teams could be useful for the improvement of the current evaluation models in primary care services.

  2. Hydration of Portoguese cements, measurement and modelling of chemical shrinkage

    DEFF Research Database (Denmark)

    Maia, Lino; Geiker, Mette Rica; Figueiras, Joaquim A.

    2008-01-01

    form of the dispersion model. The development of hydration varied between the investigated cements; based on the measured data the degree of hydration after 24 h hydration at 20 C varied between 40 and 50%. This should be taken into account when comparing properties of concrete made from the different......Development of cement hydration was studied by measuring the chemical shrinkage of pastes. Five types of Portuguese Portland cement were used in cement pastes with . Chemical shrinkage was measured by gravimetry and dilatometry. In gravimeters results were recorded automatically during at least...... seven days, dilatometers were manually recorded during at least 56 days. The dispersion model was applied to fit chemical shrinkage results and to estimate the maximum (or ultimate) value for calculation of degree of hydration. Except for a pure Portland cement best fits were obtained by the general...

  3. Synthetic ultraviolet light filtering chemical contamination of coastal waters of Virgin Islands National Park, St. John, U.S. Virgin Islands

    Science.gov (United States)

    Bargar, Timothy A.; Alvarez, David; Garrison, Virginia H.

    2015-01-01

    Contamination of surface waters by synthetic ultraviolet light (UV) filtering chemicals is a concern for the Virgin Islands National Park (VINP). Discrete water samples were collected from VINP bays to determine UV filter chemical presence in the coastal waters. Spatial distribution and the potential for partitioning between subsurface waters and the sea surface microlayer (SML) were also examined. The UV filter chemicals 4-methylbenzylidene camphor, benzophenone-3, octinoxate, homosalate, and octocrylene were detected at concentrations up to 6073 ng/L (benzophenone-3). Concentrations for benzophenone-3 and homosalate declined exponentially (r2 = 0.86 to 0.98) with distance from the beach. Limited data indicate that some UV filter chemicals may partition to the SML relative to the subsurface waters. Contamination of VINP coastal waters by UV filter chemicals may be a significant issue, but an improved understanding of the temporal and spatial variability of their concentrations would be necessary to better understand the risk they present.

  4. FBX aqueous chemical dosimeter for measurement of dosimetric parameters.

    Science.gov (United States)

    Moussous, O; Medjadj, T; Benguerba, M

    2011-02-01

    We investigated the ferrous sulphate-benzoic acid-xylenol orange (FBX) aqueous chemical dosimeter for measurement of dosimetric parameters such as the output factor, backscatter factor and lateral beam profiles for different square fields sizes for (60)Co γ-rays. A water phantom was employed to measure these parameters. An ionization chamber (IC) was used for calibration and comparison. A comparison of the resulting measurements with an ionization chamber's measured parameters showed good agreement. We thus believe that the tissue equivalent FBX dosimetry system can measure the dosimetric parameters for (60)Co with reasonable accuracy. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. In situ measurements of the compressibility of pure and trace element doped synthetic zircon

    Science.gov (United States)

    van Westrenen, W.; Frank, M. R.; Fei, Y.; Hanchar, J. M.; Finch, R. J.; Zha, C.-S.

    2003-04-01

    The ability of zircon to incorporate and retain trace elements and isotopic information makes it an indispensable tool for geochemists and geochronologists. In recent years, it has become apparent that trace element uptake is often limited mainly by mineral structure and compressibility (e.g. Blundy and Wood, Nature 1994). Understanding the uptake of trace elements into zircon therefore requires accurate knowledge of crystal-structural changes as a function of pressure, temperature, and trace element doping levels (e.g. Finch et al., Am Min 2001). We have determined the room temperature compressibility of pure, synthetic zircon (ZrSiO_4) and zircon doped with around 10 wt% of (REE + P) impurities. Samples were grown from a Li-Mo flux (Hanchar et al., Am Min 2001). Room temperature unit cell volumes of powdered samples were measured in situ in a diamond anvil cell at pressures up to 30 GPa, using angle-dispersive synchrotron X-ray diffraction techniques at CHESS. A third order Birch-Murnaghan equation of state was fitted to our data. The best fit room temperature bulk modulus for pure zircon K = 201 ± 1 GPa, with K' = 4.0 ± 0.2 and room pressure unit cell volume V_0 = 260.76 ± 0.04 Å^3. This bulk modulus is over 11% lower than suggested by earlier studies on natural (Hf-bearing) zircon samples (e.g. Hazen and Finger, Am Min 1979), which only covered pressures up to 4.8 GPa. In addition, we observe the start of the transformation of zircon to reidite (scheelite-structured ZrSiO_4) at a pressure of 19.7 GPa, over 3 GPa lower than previously measured for natural (impure) zircon (Knittle and Williams, Am Min 1993). Results for trace element doped zircon are significantly different, with K = 184 ± 1 GPa, K' = 4.8 ± 0.2, and V_0 = 263.94 ± 0.08 Å^3. In this case the reidite structure does not appear until P exceeds 22.5 GPa. Our results suggest that trace element concentration levels may have a significant effect on the compressibility and phase transition

  6. [Quality assurance of the chemical analysis measurements of foods].

    Science.gov (United States)

    Matsuda, Rieko

    2012-01-01

    This document outlined the quality assurance of measurements in the chemical analysis practiced in the food testing in Japan. The quality required for a measurement is the confidence, but necessary degree of confidence is dependent on the intended use of the measurement. The recognition of the purpose of measurement is important in quality assurance of measurements. Once the required quality is decided, the quality of the measurement is assured by various quality assurance means. The international documents about quality assurance of measurement are introduced in this document, as well as the domestic notifications enforced in Japan. Means such as the validation of analytical method and the internal quality control are explained. The concept of the measurement uncertainty is also introduced.

  7. Simultaneous quantitative measurement of biodegradability and toxicity of environmental chemicals

    International Nuclear Information System (INIS)

    Kayser, G.; Koch, M.; Ruck, W.

    1994-01-01

    Investigations were made on the biodegradability and bacterial toxicity of chemicals. The intention was to obtain data necessary for estimating and judging the behaviour of these chemicals during aerobic biological waste water treatment. The course of biodegradation and toxicity with time and concentration could be measured, quantified and described. As test procedure, the respirometric dilution method was used. This method is based on a die away test with continuous measuring of the oxygen used for biochemical oxidation processes. The course of the oxygen demand with time and concentration shows the biodegradation and toxicity patterns of the tested chemical. A variety of household and industrial chemicals were investigated. One group of substances were microbiocides, some of which showed toxic effects at concentrations less than 20 mg/l while others were biodegradable even at concentrations of 200 mg/l. Another group of test chemicals were anionic and nonionic detergents. Unexpectedly, some of these substances were toxic at concentrations as little as 50 mg/l. (orig.) [de

  8. River Delta Subsidence Measured with Interferometric Synthetic Aperture Radar (InSAR)

    Science.gov (United States)

    Higgins, Stephanie

    This thesis addresses the need for high-resolution subsidence maps of major world river deltas. Driven by a combination of rising water, sediment compaction, and reduced sediment supply due to damming and flood control, many deltas are sinking relative to sea level. A lack of data constraining rates and patterns of subsidence has made it difficult to determine the relative contributions of each factor in any given delta, however, or to assess whether the primary drivers of land subsidence are natural or anthropogenic. In recent years, Interferometric Synthetic Aperture Radar (InSAR) has emerged as a satellite-based technique that can map ground deformation with mm-scale accuracy over thousands of square kilometers. These maps could provide critical insight into the drivers of subsidence in deltas, but InSAR is not typically applied to non-urban delta areas due to the difficulties of performing the technique in wet, vegetated settings. This thesis addresses those difficulties and achieves high-resolution measurements of ground deformation in rural deltaic areas. Chapter 1 introduces the processes that drive relative sea level rise in river deltas and investigates open questions in delta subsidence research. Chapter 2 assesses the performance of InSAR in delta settings and reviews interferogram generation in the context of delta analysis, presenting delta-specific processing details and guiding interpretation in these challenging areas. Chapter 3 applies Differential (D-) InSAR to the coast of the Yellow River Delta in China. Results show that subsidence rates are as high as 250 mm/y due to groundwater extraction at aquaculture facilities, a rate that exceeds local and global average sea level rise by nearly two orders of magnitude and suggests a significant hazard for Asian megadeltas. Chapter 4 applies interferometric stacking and Small Baseline Subset (SBAS)-InSAR to the Ganges-Brahmaputra Delta, Bangladesh. Results show that stratigraphy controls subsidence in

  9. Small-Chamber Measurements of Chemical-Specific Emission Factors for Drywall

    Energy Technology Data Exchange (ETDEWEB)

    Maddalena, Randy; Russell, Marion; Apte, Michael G.

    2010-06-01

    Imported drywall installed in U.S. homes is suspected of being a source of odorous and potentially corrosive indoor pollutants. To support an investigation of those building materials by the Consumer Products Safety Commission (CPSC), Lawrence Berkeley National Laboratory (LBNL) measured chemical-specific emission factors for 30 samples of drywall materials. Emission factors are reported for 75 chemicals and 30 different drywall samples encompassing both domestic and imported stock and incorporating natural, synthetic, or mixed gypsum core material. CPSC supplied all drywall materials. First the drywall samples were isolated and conditioned in dedicated chambers, then they were transferred to small chambers where emission testing was performed. Four sampling and analysis methods were utilized to assess (1) volatile organic compounds, (2) low molecular weight carbonyls, (3) volatile sulfur compounds, and (4) reactive sulfur gases. LBNL developed a new method that combines the use of solid phase microextraction (SPME) with small emission chambers to measure the reactive sulfur gases, then extended that technique to measure the full suite of volatile sulfur compounds. The testing procedure and analysis methods are described in detail herein. Emission factors were measured under a single set of controlled environmental conditions. The results are compared graphically for each method and in detailed tables for use in estimating indoor exposure concentrations.

  10. Chemical measurements with optical fibers for process control.

    Science.gov (United States)

    Boisde, G; Blanc, F; Perez, J J

    1988-02-01

    Several aspects of remote in situ spectrophotometric measurement by means of optical fibers are considered in the context of chemical process control. The technique makes it possible to measure a species in a particular oxidation state, such as plutonium(VI), sequentially, under the stringent conditions of automated analysis. For the control of several species in solution, measurements at discrete wavelengths on the sides of the absorption peaks serve to increase the dynamic range. Examples are given concerning the isotopic separation of uranium in the Chemex process. The chemical control of complex solutions containing numerous mutually interfering species requires a more elaborate spectral scan and real-time processing to determine the chemical kinetics. Photodiode array spectrophotometers are therefore ideal for analysing the uranium and plutonium solutions of the Purex process. Remote on-line control by ultraviolet monitoring exhibits limitations chiefly due to Rayleigh scattering in the optical fibers. The measurement of pH in acidic (0.8-3.2) and basic media (10-13) has also been attempted. Prior calibration, signal processing and optical spectra modeling are also discussed.

  11. A Synthetic Method for Atmospheric Diffusion Simulation and Environmental Impact Assessment of Accidental Pollution in the Chemical Industry in a WEBGIS Context

    Directory of Open Access Journals (Sweden)

    Haochen Ni

    2014-09-01

    Full Text Available The chemical industry poses a potential security risk to factory personnel and neighboring residents. In order to mitigate prospective damage, a synthetic method must be developed for an emergency response. With the development of environmental numeric simulation models, model integration methods, and modern information technology, many Decision Support Systems (DSSs have been established. However, existing systems still have limitations, in terms of synthetic simulation and network interoperation. In order to resolve these limitations, the matured simulation model for chemical accidents was integrated into the WEB Geographic Information System (WEBGIS platform. The complete workflow of the emergency response, including raw data (meteorology information, and accident information management, numeric simulation of different kinds of accidents, environmental impact assessments, and representation of the simulation results were achieved. This allowed comprehensive and real-time simulation of acute accidents in the chemical industry. The main contribution of this paper is that an organizational mechanism of the model set, based on the accident type and pollutant substance; a scheduling mechanism for the parallel processing of multi-accident-type, multi-accident-substance, and multi-simulation-model; and finally a presentation method for scalar and vector data on the web browser on the integration of a WEB Geographic Information System (WEBGIS platform. The outcomes demonstrated that this method could provide effective support for deciding emergency responses of acute chemical accidents.

  12. A synthetic method for atmospheric diffusion simulation and environmental impact assessment of accidental pollution in the chemical industry in a WEBGIS context.

    Science.gov (United States)

    Ni, Haochen; Rui, Yikang; Wang, Jiechen; Cheng, Liang

    2014-09-05

    The chemical industry poses a potential security risk to factory personnel and neighboring residents. In order to mitigate prospective damage, a synthetic method must be developed for an emergency response. With the development of environmental numeric simulation models, model integration methods, and modern information technology, many Decision Support Systems (DSSs) have been established. However, existing systems still have limitations, in terms of synthetic simulation and network interoperation. In order to resolve these limitations, the matured simulation model for chemical accidents was integrated into the WEB Geographic Information System (WEBGIS) platform. The complete workflow of the emergency response, including raw data (meteorology information, and accident information) management, numeric simulation of different kinds of accidents, environmental impact assessments, and representation of the simulation results were achieved. This allowed comprehensive and real-time simulation of acute accidents in the chemical industry. The main contribution of this paper is that an organizational mechanism of the model set, based on the accident type and pollutant substance; a scheduling mechanism for the parallel processing of multi-accident-type, multi-accident-substance, and multi-simulation-model; and finally a presentation method for scalar and vector data on the web browser on the integration of a WEB Geographic Information System (WEBGIS) platform. The outcomes demonstrated that this method could provide effective support for deciding emergency responses of acute chemical accidents.

  13. Chemical Composition Measurements of LAWA44 Glass Samples

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Riley, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-11-15

    DOE is building the Hanford Tank Waste Treatment and Immobilization Plant (WTP) at the Hanford Site in Washington to remediate 55 million gallons of radioactive waste that is temporarily stored in 177 underground tanks. Both low-activity and high-level wastes will then be vitrified into borosilicate glass using Joule-heated ceramic melters. Efforts are being made to increase the loading of Hanford tank wastes in the glass. One area of work is enhancing waste glass composition/property models and broadening the compositional regions over which those models are applicable. In this report, the Savannah River National Laboratory provides chemical analysis results for several samples of a simulated low-activity waste glass, LAWA44, provided by the Pacific Northwest National Laboratory as part of an ongoing development task. The measured chemical composition data are reported and compared with the targeted values for each component for each glass. A detailed review showed no indications of errors in the preparation or measurement of the study glasses. All of the measured sums of oxides for the study glasses fell within the interval of 97.9 to 102.6 wt %, indicating acceptable recovery of the glass components. Comparisons of the targeted and measured chemical compositions showed that the measured values for the glasses met the targeted concentrations within 10% for those components present at more than 5 wt %. It was noted that the measured B2O3 concentrations are somewhat above the targeted values for the study glasses. No obvious trends were observed with regard to the multiple melting steps used to prepare the study glasses, indicating that any potential effects of volatility were below measurable thresholds.

  14. Kinetic Analyses of Cation Exchange Rates in Synthetic Birnessite Measured by Time- Resolved Synchrotron X-ray Diffraction

    Science.gov (United States)

    Lopano, C. L.; Heaney, P. J.; Post, J. E.; Bandstra, J.; Brantley, S. L.

    2006-05-01

    Birnessite is the most abundant and chemically important layer-structure Mn-oxide phase found in soils, desert varnishes, and ocean nodules. It also is industrially important for use in battery technology and octahedral sieves. Due to the poorly crystalline nature of natural birnessite, synthetic analogues typically have been employed in studies that explore the structural response of birnessite to variations in interlayer composition. For this work, we measured changes in unit-cell parameters over time to quantify the degree of cation exchange as a function of concentration. Aqueous K+, Cs+, and Ba2+ cations at varying concentrations at pH 7 were exchanged for interlayer Na+ in synthetic birnessite (Na0.58(Mn4+1.42,Mn3+0.58)O4·1.5H2O) using a simple flow- through cell, and the exchange products were monitored via time-resolved X-ray powder diffraction at the National Synchrotron Light Source. Powder X-ray diffraction patterns were collected every 2-3 minutes. Rietveld analyses of X-ray diffraction patterns for K- and Ba-exchanged birnessite revealed a decrease in unit- cell volume over time. In contrast, Cs+ substitution increased cell volume. For all three cations, the crystallographic data indicate that exchange occurred in two stages. A rapid and dramatic change in unit-cell volume was followed by a modest adjustment over longer timescales. Fourier electron difference syntheses revealed that the rapid, initial stage of exchange was marked by re-configuration of the interlayer species, whereas the second, protracted phase of substitution represented ordering into the newly established interlayer positions. For the first time, we have modeled the kinetics of interlayer substitution in Na-birnessite. For purposes of comparison, we have employed a simple one-stage reaction (i.e., Na-birnessite → K-birnessite) and a two stage reaction (i.e,. Na-birnessite → K-birnessitedisordered → K- birnessiteordered). For exchange with 0.01 M KCl solutions, the single

  15. Louisiana SIP: LAC 33:III Ch 21 Subchap J, 2147--Limiting Volatile Organic Compound (VOC) Emissions from Reactor Processes and Distillation Operations in Synthetic Organic Chemical manufacturing Industry (SOCMI); SIP effective 1998-02-02 (LAc74) to more..

    Science.gov (United States)

    Louisiana SIP: LAC 33:III Ch 21 Subchap J, 2147--Limiting Volatile Organic Compound (VOC) Emissions from Reactor Processes and Distillation Operations in Synthetic Organic Chemical manufacturing Industry (SOCMI); SIP effective 1998-02-02 (LAc74) more...

  16. Louisiana SIP: LAC 33:III Ch 2147. Limiting Volatile Organic Compound (VOC) Emissions from Reactor Processes and Distillation Operations in Synthetic Organic Chemical manufacturing Industry (SOCMI); SIP effective 2011-08-04 (LAd34) to 2017-09-27

    Science.gov (United States)

    Louisiana SIP: LAC 33:III Ch 2147. Limiting Volatile Organic Compound (VOC) Emissions from Reactor Processes and Distillation Operations in Synthetic Organic Chemical manufacturing Industry (SOCMI); SIP effective 2011-08-04 (LAd34) to 2017-09-27

  17. Precision measurement of refractive index of air based on laser synthetic wavelength interferometry with Edlén equation estimation.

    Science.gov (United States)

    Yan, Liping; Chen, Benyong; Zhang, Enzheng; Zhang, Shihua; Yang, Ye

    2015-08-01

    A novel method for the precision measurement of refractive index of air (n(air)) based on the combining of the laser synthetic wavelength interferometry with the Edlén equation estimation is proposed. First, a n(air_e) is calculated from the modified Edlén equation according to environmental parameters measured by low precision sensors with an uncertainty of 10(-6). Second, a unique integral fringe number N corresponding to n(air) is determined based on the calculated n(air_e). Then, a fractional fringe ε corresponding to n(air) with high accuracy can be obtained according to the principle of fringe subdivision of laser synthetic wavelength interferometry. Finally, high accurate measurement of n(air) is achieved according to the determined fringes N and ε. The merit of the proposed method is that it not only solves the problem of the measurement accuracy of n(air) being limited by the accuracies of environmental sensors, but also avoids adopting complicated vacuum pumping to measure the integral fringe N in the method of conventional laser interferometry. To verify the feasibility of the proposed method, comparison experiments with Edlén equations in short time and in long time were performed. Experimental results show that the measurement accuracy of n(air) is better than 2.5 × 10(-8) in short time tests and 6.2 × 10(-8) in long time tests.

  18. Measurement of chemical diffusion coefficients in liquid binary alloys

    International Nuclear Information System (INIS)

    Keita, M.; Steinemann, S.; Kuenzi, H.U.

    1976-01-01

    New measurements of the chemical diffusion coefficient in liquid binary alloys are presented. The wellknown geometry of the 'capillary-reservoir' is used and the concentration is obtained from a resistivity measurement. The method allows to follow continuously the diffusion process in the liquid state. A precision of at least 10% in the diffusion coefficient is obtained with a reproductibility better than 5%. The systems Hg-In, Al-Sn, Al-Si have been studied. Diffusion coefficients are obtained as a function of temperature, concentration, and geometrical factors related to the capillary (diameter, relative orientation of density gradient and gravity). (orig.) [de

  19. Direct measurement of the reaction front in chemically amplified photoresists.

    Science.gov (United States)

    Lin, Eric K; Soles, Christopher L; Goldfarb, Dario L; Trinque, Brian C; Burns, Sean D; Jones, Ronald L; Lenhart, Joseph L; Angelopoulos, Marie; Willson, C Grant; Satija, Sushil K; Wu, Wen-Li

    2002-07-19

    The continuing drive by the semiconductor industry to fabricate smaller structures using photolithography will soon require dimensional control at length scales comparable to the size of the polymeric molecules in the materials used to pattern them. The current technology, chemically amplified photoresists, uses a complex reaction-diffusion process to delineate patterned areas with high spatial resolution. However, nanometer-level control of this critical process is limited by the lack of direct measurements of the reaction front. We demonstrate the use of x-ray and neutron reflectometry as a general method to measure the spatial evolution of the reaction-diffusion process with nanometer resolution. Measuring compositional profiles, provided by deuterium-labeled reactant groups for neutron scattering contrast, we show that the reaction front within the material is broad rather than sharply defined and the compositional profile is altered during development. Measuring the density profile, we directly correlate the developed film structure with that of the reaction front.

  20. Case–control study of breast cancer and exposure to synthetic environmental chemicals among Alaska Native women

    Directory of Open Access Journals (Sweden)

    Adrianne K. Holmes

    2014-11-01

    Full Text Available Background: Exposure to environmental chemicals may impair endocrine system function. Alaska Native (AN women may be at higher risk of exposure to these endocrine disrupting chemicals, which may contribute to breast cancer in this population. Objective: To measure the association between exposure to select environmental chemicals and breast cancer among AN women. Design: A case–control study of 170 women (75 cases, 95 controls recruited from the AN Medical Center from 1999 to 2002. Participants provided urine and serum samples. Serum was analyzed for 9 persistent pesticides, 34 polychlorinated biphenyl (PCB congeners, and 8 polybrominated diethyl ether (PBDE congeners. Urine was analyzed for 10 phthalate metabolites. We calculated geometric means (GM and compared cases and controls using logistic regression. Results: Serum concentrations of most pesticides and 3 indicator PCB congeners (PCB-138/158; PCB-153, PCB-180 were lower in case women than controls. BDE-47 was significantly higher in case women (GM=38.8 ng/g lipid than controls (GM=25.1 ng/g lipid (p=0.04. Persistent pesticides, PCBs, and most phthalate metabolites were not associated with case status in univariate logistic regression. The odds of being a case were higher for those with urinary mono-(2-ethylhexyl phthalate (MEHP concentrations that were above the median; this relationship was seen in both univariate (OR 2.16, 95% CI 1.16–4.05, p=0.02 and multivariable (OR 2.43, 95% CI 1.13–5.25, p=0.02 logistic regression. Women with oestrogen receptor (ER–/progesterone receptor (PR-tumour types tended to have higher concentrations of persistent pesticides than did ER+/PR+ women, although these differences were not statistically significant. Conclusions: Exposure to the parent compound of the phthalate metabolite MEHP may be associated with breast cancer. However, our study is limited by small sample size and an inability to control for the confounding effects of body mass index

  1. Chemical, Biological, and Explosive Sensors for Field Measurements

    International Nuclear Information System (INIS)

    Kyle, Kevin; Manard, Manuel; Weeks, Stephan

    2009-01-01

    Special Technologies Laboratory (STL) is developing handheld chemical, biological, and explosive (CBE) detection systems and sensor motes for wireless networked field operations. The CBE sensors are capable of detecting and identifying multiple targeted toxic industrial chemicals (TICs) and high-explosive vapor components. The CBE devices are based on differential mobility spectrometry (DMS) coupled with fast gas chromatography (GC) or mass spectrometry. The systems all include the concepts of: (1) Direct air/particulate 'smart' sampling; (2) Selective, continuous real-time (∼1 sec) alert monitoring using DMS; and (3) Highly selective, rapid dual technology separation/verification analysis The biosensor technology is based on Raman aerosol particle flow cytometry for target detection and identification. Monitoring and identifying trace level chemical vapors directly from ambient air will allow First Responders to quickly adapt situational response strategies and personal protective equipment needs to the specific response scenario being encountered. First Responders require great confidence in the measurements and ability of a given system to detect CBE below threshold levels without interferences. The concept of determining the background matrix in near real-time to allow subsequent automated field-programmable method selection and cueing of high-value assets in a wide range of environs will be presented. This provides CBE information for decisions prior to First Responders entering the response site or sending a portable mobile unit for a remote site survey of the hazards. The focus is on real-time information needed by those responsible for emergency response and national security

  2. Chemical, Biological, and Explosive Sensors for Field Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Kyle, Manuel Manard, Stephan Weeks

    2009-01-31

    Special Technologies Laboratory (STL) is developing handheld chemical, biological, and explosive (CBE) detection systems and sensor motes for wireless networked field operations. The CBE sensors are capable of detecting and identifying multiple targeted toxic industrial chemicals (TICs) and high-explosive vapor components. The CBE devices are based on differential mobility spectrometry (DMS) coupled with fast gas chromatography (GC) or mass spectrometry. The systems all include the concepts of: 1. Direct air/particulate “smart” sampling 2. Selective, continuous real-time (~1 sec) alert monitoring using DMS 3. Highly selective, rapid dual technology separation/verification analysis The biosensor technology is based on Raman aerosol particle flow cytometry for target detection and identification. Monitoring and identifying trace level chemical vapors directly from ambient air will allow First Responders to quickly adapt situational response strategies and personal protective equipment needs to the specific response scenario being encountered. First Responders require great confidence in the measurements and ability of a given system to detect CBE below threshold levels without interferences. The concept of determining the background matrix in near real-time to allow subsequent automated field-programmable method selection and cueing of high-value assets in a wide range of environs will be presented. This provides CBE information for decisions prior to First Responders entering the response site or sending a portable mobile unit for a remote site survey of the hazards. The focus is on real-time information needed by those responsible for emergency response and national security.

  3. Synthetic Base Fluids

    Science.gov (United States)

    Brown, M.; Fotheringham, J. D.; Hoyes, T. J.; Mortier, R. M.; Orszulik, S. T.; Randles, S. J.; Stroud, P. M.

    The chemical nature and technology of the main synthetic lubricant base fluids is described, covering polyalphaolefins, alkylated aromatics, gas-to-liquid (GTL) base fluids, polybutenes, aliphatic diesters, polyolesters, polyalkylene glycols or PAGs and phosphate esters.Other synthetic lubricant base oils such as the silicones, borate esters, perfluoroethers and polyphenylene ethers are considered to have restricted applications due to either high cost or performance limitations and are not considered here.Each of the main synthetic base fluids is described for their chemical and physical properties, manufacture and production, their chemistry, key properties, applications and their implications when used in the environment.

  4. Palladium Mediated Rapid Deprotection of N-Terminal Cysteine under Native Chemical Ligation Conditions for the Efficient Preparation of Synthetically Challenging Proteins.

    Science.gov (United States)

    Jbara, Muhammad; Maity, Suman Kumar; Seenaiah, Mallikanti; Brik, Ashraf

    2016-04-20

    Facilitating the process of chemical protein synthesis is an important goal in order to enable the efficient preparation of large and novel protein analogues. Native chemical ligation, which is widely used in the synthesis and semisynthesis of proteins, has been going through several developments to expedite the synthetic process and to obtain the target protein in high yield. A key aspect of this approach is the utilization of protecting groups for the N-terminal Cys in the middle fragments, which bear simultaneously the two reactive groups, i.e., N-terminal Cys and C-terminal thioester. Despite important progress in this area, as has been demonstrated in the use of thiazolidine protecting group in the synthesis of over 100 proteins, finding optimal protecting group(s) remains a challenge. For example, the thiazolidine removal step is very slow (>8 h), and in some cases the applied conditions lead to undesired side reactions. Here we show that water-soluble palladium(II) complexes are excellent reagents for the effective unmasking of thiazolidine, enabling its complete removal within 15 min under native chemical ligation conditions. Moreover, palladium is also able to rapidly remove propargyloxycarbonyl-protecting group from the N-terminal Cys in a similar efficiency. The utility of the new removal conditions for both protecting groups is exemplified in the rapid and efficient synthesis of Lys34-ubiquitinated H2B and for the first time neddlyated peptides derived from cullin1. The current approach expands the use of palladium in protein chemistry and should significantly facilitate the chemical and semisynthesis of synthetically challenging proteins from multiple fragments.

  5. [Measurement of chemical agents in metallurgy field: electric steel plant].

    Science.gov (United States)

    Cottica, D; Grignani, E; Ghitti, R; Festa, D; Apostoli, P

    2012-01-01

    The steel industry maintains its important position in the context of the Italian production involving thousands of workers. The iron and steel processes are divided into primary steel industry, production of intermediate minerals, and secondary steel, scrap from the production of semi-finished industrial and consumer sector (metal inserted into components and metal used for dissipative uses, primarily coatings) and industrial waste. The paper presents the results of environmental monitoring carried out in some electric steel plant for the measurement of airborne chemicals that characterize the occupational exposure of workers employed in particular area like electric oven, to treatment outside the furnace, continuous casting area. For the sampling of the pollutants were used both personal and in fixed positions samplers. The pollutants measured are those typical of steel processes inhalable dust, metals, respirable dust, crystalline silica, but also Polycyclic Aromatic Hydrocarbons (PAH), polychlorinated dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs).

  6. Hydrogeology, Chemical and Microbial Activity Measurement Through Deep Permafrost

    Science.gov (United States)

    Stotler, R.L.; Frape, S.K.; Freifeld, B.M.; Holden, B.; Onstott, T.C.; Ruskeeniemi, T.; Chan, E.

    2011-01-01

    Little is known about hydrogeochemical conditions beneath thick permafrost, particularly in fractured crystalline rock, due to difficulty in accessing this environment. The purpose of this investigation was to develop methods to obtain physical, chemical, and microbial information about the subpermafrost environment from a surface-drilled borehole. Using a U-tube, gas and water samples were collected, along with temperature, pressure, and hydraulic conductivity measurements, 420 m below ground surface, within a 535 m long, angled borehole at High Lake, Nunavut, Canada, in an area with 460-m-thick permafrost. Piezometric head was well above the base of the permafrost, near land surface. Initial water samples were contaminated with drill fluid, with later samples values ???5??? lower than the local surface water. The fluid isotopic composition was affected by the permafrost-formation process. Nonbacteriogenic CH4 was present and the sample location was within methane hydrate stability field. Sampling lines froze before uncontaminated samples from the subpermafrost environment could be obtained, yet the available time to obtain water samples was extended compared to previous studies. Temperature measurements collected from a distributed temperature sensor indicated that this issue can be overcome easily in the future. The lack of methanogenic CH4 is consistent with the high sulfate concentrations observed in cores. The combined surface-drilled borehole/U-tube approach can provide a large amount of physical, chemical, and microbial data from the subpermafrost environment with few, controllable, sources of contamination. ?? 2010 The Author(s). Journal compilation ?? 2010 National Ground Water Association.

  7. Measurements and Models for Hazardous chemical and Mixed Wastes

    Energy Technology Data Exchange (ETDEWEB)

    Laurel A. Watts; Cynthia D. Holcomb; Stephanie L. Outcalt; Beverly Louie; Michael E. Mullins; Tony N. Rogers

    2002-08-21

    Mixed solvent aqueous waste of various chemical compositions constitutes a significant fraction of the total waste produced by industry in the United States. Not only does the chemical process industry create large quantities of aqueous waste, but the majority of the waste inventory at the DOE sites previously used for nuclear weapons production is mixed solvent aqueous waste. In addition, large quantities of waste are expected to be generated in the clean-up of those sites. In order to effectively treat, safely handle, and properly dispose of these wastes, accurate and comprehensive knowledge of basic thermophysical properties is essential. The goal of this work is to develop a phase equilibrium model for mixed solvent aqueous solutions containing salts. An equation of state was sought for these mixtures that (a) would require a minimum of adjustable parameters and (b) could be obtained from a available data or data that were easily measured. A model was developed to predict vapor composition and pressure given the liquid composition and temperature. It is based on the Peng-Robinson equation of state, adapted to include non-volatile and salt components. The model itself is capable of predicting the vapor-liquid equilibria of a wide variety of systems composed of water, organic solvents, salts, nonvolatile solutes, and acids or bases. The representative system o water + acetone + 2-propanol + NaNo3 was selected to test and verify the model. Vapor-liquid equilibrium and phase density measurements were performed for this system and its constituent binaries.

  8. Atmospheric measurements of peroxy radicals by chemical amplification

    Science.gov (United States)

    Duncianu, Marius; Lahib, Ahmad; Tomas, Alexandre; Dusanter, Sébastien

    2017-04-01

    Peroxy radicals (HO2 and RO2) are key species in atmospheric chemistry. They are produced during the oxidation of volatile organic compounds (VOCs) and are involved in the formation of ozone and secondary organic aerosols. However, ambient measurements of these reactive species are still considered challenging and only a few techniques have been used for field measurements. Among these techniques, the PEroxy Radical Chemical Amplifier (PERCA) implementing the classical NO/CO reagent approach has been hardly used for field measurements due to the strong dependence of the radical chain length on Relative Humidity (RH). However, Wood et al. (ES&T 2016) recently showed that using ethane instead of CO allows reducing this RH-dependence and helps going around other drawbacks of the CO based amplification chemistry. This new approach has been explored in our laboratory by building a PERCA instrument that will be used for both laboratory kinetics and field measurements. In this presentation, we will describe (i) the measurement setup and (ii) experiments conducted to quantify the radical chain length for HO2 and several RO2 radicals, including those produced during the OH-oxidation of isoprene, toluene, cyclohexane, and others. It will be shown that the detection efficiency of organic peroxy radicals, via their NO conversion to HO2, mainly depends on their organic nitrate (RONO2) formation yields. In this context, box modelling of the PERCA chemistry will be discussed.

  9. Experimental Measurements of Journal Bearing Friction Using Mineral, Synthetic, and Bio-Based Lubricants

    Directory of Open Access Journals (Sweden)

    Pantelis G. Nikolakopoulos

    2015-04-01

    Full Text Available The environmental impact of many industrial and naval applications is becoming increasingly important. Journal bearings are crucial components related with the reliable, safe and environmentally friendly operation of rotating machinery in many applications, e.g., in hydroplants, ships, power generation stations. The maintenance activities in certain cases also have considerable environmental impact. Fortunately, it is relatively easy to reduce the impact by changing the way lubricants are being used. Selecting the proper lubricant is important to sharply reduce long-term costs. The best-fit product selection can mean longer lubricant life, reduced machine wear, reduced incipient power losses and improved safety. Suitable basestocks and additives reduce environmental impact. In this paper, three types of lubricants are used in order to examine their effects on the tribological behavior of journal bearings. A mineral oil, a synthetic oil and a bio-based lubricant are experimentally and analytically examined for several configurations of load and journal rotational velocity. The friction forces and the hydrodynamic friction coefficients are calculated and compared. This investigation can assist the correct choice of lubricant in journal bearings with minimized environmental footprint.

  10. A Short Review of Chemical Reaction Database Systems, Computer-Aided Synthesis Design, Reaction Prediction and Synthetic Feasibility.

    Science.gov (United States)

    Warr, Wendy A

    2014-06-01

    This article is the text for a pedagogical lecture to be given at the Strasbourg Summer School in Chemoinformatics in June 2104. It covers a very wide range of reaction topics including structure and reaction representation, reaction centers, atom-to-atom mapping, reaction retrieval systems, computer-aided synthesis design, retrosynthesis, reaction prediction and synthetic feasibility. In the time available the coverage of each topic can only be cursory; the main usefulness of this article to the research community is the extensive bibliography. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  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. Improved measurements of mean sea surface velocity in the Nordic Seas from synthetic aperture radar

    Science.gov (United States)

    Wergeland Hansen, Morten; Johnsen, Harald; Engen, Geir; Øie Nilsen, Jan Even

    2017-04-01

    The warm and saline surface Atlantic Water (AW) flowing into the Nordic Seas across the Greenland-Scotland ridge transports heat into the Arctic, maintaining the ice-free oceans and regulating sea-ice extent. The AW influences the region's relatively mild climate and is the northern branch of the global thermohaline overturning circulation. Heat loss in the Norwegian Sea is key for both heat transport and deep water formation. In general, the ocean currents in the Nordic Seas and the North Atlantic Ocean is a complex system of topographically steered barotropic and baroclinic currents of which the wind stress and its variability is a driver of major importance. The synthetic aperture radar (SAR) Doppler centroid shift has been demonstrated to contain geophysical information about sea surface wind, waves and current at an accuracy of 5 Hz and pixel spacing of 3.5 - 9 × 8 km2. This corresponds to a horizontal surface velocity of about 20 cm/s at 35° incidence angle. The ESA Prodex ISAR project aims to implement new and improved SAR Doppler shift processing routines to enable reprocessing of the wide swath acquisitions available from the Envisat ASAR archive (2002-2012) at higher resolution and better accuracy than previously obtained, allowing combined use with Sentinel-1 and Radarsat-2 retrievals to build timeseries of the sea surface velocity in the Nordic Seas. Estimation of the geophysical Doppler shift from new SAR Doppler centroid shift retrievals will be demonstrated, addressing key issues relating to geometric (satellite orbit and attitude) and electronic (antenna mis-pointing) contributions and corrections. Geophysical Doppler shift retrievals from one month of data in January 2010 and the inverted surface velocity in the Nordic Seas are then addressed and compared to other direct and indirect estimates of the upper ocean current, in particular those obtained in the ESA GlobCurrent project.

  13. Heavy ion measurements by use of chemical detectors

    International Nuclear Information System (INIS)

    Huebner, K.; Erzgraeber, G.; Eichhorn, K.

    1980-01-01

    In order to test whether the threshold system polyvinyl alcohol/methyl organe/chloral hydrate/sodium tetraborate permits quantitative detection of individual particles, the chemical detector was irradiated at the JINR U-200 cyclotron with 4 He, 12 C, 18 O, 22 Ne ions having different LET. Irradiations were performed with detectors of four different borax concentrations (the chloral hydrate concentration being constant). The colour change dose Dsub(u) increases linearly with increasing borax concentration and at constant borax concentration with increasing LET. Hence it follows that the G value of dehydrochlorination decreases with increasing LET. Fluence ranges measurable with detectors of different composition are given for the heavy ions studied. (author)

  14. Measurement of gas transport properties for chemical vapor infiltration

    Energy Technology Data Exchange (ETDEWEB)

    Starr, T.L.; Hablutzel, N. [Georgia Inst. of Tech., Atlanta, GA (United States). School of Materials Science and Engineering

    1996-12-01

    In the chemical vapor infiltration (CVI) process for fabricating ceramic matrix composites (CMCs), transport of gas phase reactant into the fiber preform is a critical step. The transport can be driven by pressure or by concentration. This report describes methods for measuring this for CVI preforms and partially infiltrated composites. Results are presented for Nicalon fiber cloth layup preforms and composites, Nextel fiber braid preforms and composites, and a Nicalon fiber 3-D weave composite. The results are consistent with a percolating network model for gas transport in CVI preforms and composites. This model predicts inherent variability in local pore characteristics and transport properties, and therefore, in local densification during processing; this may lead to production of gastight composites.

  15. Chemical Thermodynamics of Aqueous Atmospheric Aerosols: Modeling and Microfluidic Measurements

    Science.gov (United States)

    Nandy, L.; Dutcher, C. S.

    2017-12-01

    Accurate predictions of gas-liquid-solid equilibrium phase partitioning of atmospheric aerosols by thermodynamic modeling and measurements is critical for determining particle composition and internal structure at conditions relevant to the atmosphere. Organic acids that originate from biomass burning, and direct biogenic emission make up a significant fraction of the organic mass in atmospheric aerosol particles. In addition, inorganic compounds like ammonium sulfate and sea salt also exist in atmospheric aerosols, that results in a mixture of single, double or triple charged ions, and non-dissociated and partially dissociated organic acids. Statistical mechanics based on a multilayer adsorption isotherm model can be applied to these complex aqueous environments for predictions of thermodynamic properties. In this work, thermodynamic analytic predictive models are developed for multicomponent aqueous solutions (consisting of partially dissociating organic and inorganic acids, fully dissociating symmetric and asymmetric electrolytes, and neutral organic compounds) over the entire relative humidity range, that represent a significant advancement towards a fully predictive model. The model is also developed at varied temperatures for electrolytes and organic compounds the data for which are available at different temperatures. In addition to the modeling approach, water loss of multicomponent aerosol particles is measured by microfluidic experiments to parameterize and validate the model. In the experimental microfluidic measurements, atmospheric aerosol droplet chemical mimics (organic acids and secondary organic aerosol (SOA) samples) are generated in microfluidic channels and stored and imaged in passive traps until dehydration to study the influence of relative humidity and water loss on phase behavior.

  16. Hydrogeology, chemical and microbial activity measurement through deep permafrost.

    Science.gov (United States)

    Stotler, Randy L; Frape, Shaun K; Freifeld, Barry M; Holden, Brian; Onstott, Tullis C; Ruskeeniemi, Timo; Chan, Eric

    2011-01-01

    Little is known about hydrogeochemical conditions beneath thick permafrost, particularly in fractured crystalline rock, due to difficulty in accessing this environment. The purpose of this investigation was to develop methods to obtain physical, chemical, and microbial information about the subpermafrost environment from a surface-drilled borehole. Using a U-tube, gas and water samples were collected, along with temperature, pressure, and hydraulic conductivity measurements, 420 m below ground surface, within a 535 m long, angled borehole at High Lake, Nunavut, Canada, in an area with 460-m-thick permafrost. Piezometric head was well above the base of the permafrost, near land surface. Initial water samples were contaminated with drill fluid, with later samples <40% drill fluid. The salinity of the non-drill fluid component was <20,000 mg/L, had a Ca/Na ratio above 1, with δ(18) O values ∼5‰ lower than the local surface water. The fluid isotopic composition was affected by the permafrost-formation process. Nonbacteriogenic CH(4) was present and the sample location was within methane hydrate stability field. Sampling lines froze before uncontaminated samples from the subpermafrost environment could be obtained, yet the available time to obtain water samples was extended compared to previous studies. Temperature measurements collected from a distributed temperature sensor indicated that this issue can be overcome easily in the future. The lack of methanogenic CH(4) is consistent with the high sulfate concentrations observed in cores. The combined surface-drilled borehole/U-tube approach can provide a large amount of physical, chemical, and microbial data from the subpermafrost environment with few, controllable, sources of contamination. Copyright © 2010 The Author(s). Journal compilation © 2010 National Ground Water Association.

  17. Hydrogeology, chemical and microbial activity measurement through deep permafrost

    Energy Technology Data Exchange (ETDEWEB)

    Stotler, R.L.; Frape, S.K.; Freifeld, B.M.; Holden, B.; Onstott, T.C.; Ruskeeniemi, T.; Chan, E.

    2010-04-01

    Little is known about hydrogeochemical conditions beneath thick permafrost, particularly in fractured crystalline rock, due to difficulty in accessing this environment. The purpose of this investigation was to develop methods to obtain physical, chemical, and microbial information about the subpermafrost environment from a surface-drilled borehole. Using a U-tube, gas and water samples were collected, along with temperature, pressure, and hydraulic conductivity measurements, 420 m below ground surface, within a 535 m long, angled borehole at High Lake, Nunavut, Canada, in an area with 460-m-thick permafrost. Piezometric head was well above the base of the permafrost, near land surface. Initial water samples were contaminated with drill fluid, with later samples <40% drill fluid. The salinity of the non-drill fluid component was <20,000 mg/L, had a Ca/Na ratio above 1, with {delta}{sup 18}O values {approx}5{per_thousand} lower than the local surface water. The fluid isotopic composition was affected by the permafrost-formation process. Nonbacteriogenic CH{sub 4} was present and the sample location was within methane hydrate stability field. Sampling lines froze before uncontaminated samples from the subpermafrost environment could be obtained, yet the available time to obtain water samples was extended compared to previous studies. Temperature measurements collected from a distributed temperature sensor indicated that this issue can be overcome easily in the future. The lack of methanogenic CH{sub 4} is consistent with the high sulfate concentrations observed in cores. The combined surface-drilled borehole/U-tube approach can provide a large amount of physical, chemical, and microbial data from the subpermafrost environment with few, controllable, sources of contamination.

  18. Measurement and Model for Hazardous Chemical and Mixed Waste

    Energy Technology Data Exchange (ETDEWEB)

    Michael E. Mullins; Tony N. Rogers; Stephanie L. Outcalt; Beverly Louie; Laurel A. Watts; Cynthia D. Holcomb

    2002-07-30

    Mixed solvent aqueous waste of various chemical compositions constitutes a significant fraction of the total waste produced by industry in the United States. Not only does the chemical process industry create large quantities of aqueous waste, but the majority of the waste inventory at the Department of Energy (DOE) sites previously used for nuclear weapons production is mixed solvent aqueous waste. In addition, large quantities of waste are expected to be generated in the clean-up of those sites. In order to effectively treat, safely handle, and properly dispose of these wastes, accurate and comprehensive knowledge of basic thermophysical properties is essential. The goal of this work is to develop a phase equilibrium model for mixed solvent aqueous solutions containing salts. An equation of state was sought for these mixtures that (a) would require a minimum of adjustable parameters and (b) could be obtained from a available data or data that were easily measured. A model was developed to predict vapor composition and pressure given the liquid composition and temperature. It is based on the Peng-Robinson equation of state, adapted to include non-volatile and salt components. The model itself is capable of predicting the vapor-liquid equilibria of a wide variety of systems composed of water, organic solvents, salts, nonvolatile solutes, and acids or bases. The representative system of water + acetone + 2-propanol + NaNO3 was selected to test and verify the model. Vapor-liquid equilibrium and phase density measurements were performed for this system and its constituent binaries.

  19. Synthetic thermosphere winds based on CHAMP neutral and plasma density measurements

    NARCIS (Netherlands)

    Gasperini, F; Forbes, J. M.; Doornbos, E.N.; Bruinsma, S. L.

    2016-01-01

    Meridional winds in the thermosphere are key to understanding latitudinal coupling and thermosphere-ionosphere coupling, and yet global measurements of this wind component are scarce. In this work, neutral and electron densities measured by the Challenging Minisatellite Payload (CHAMP) satellite

  20. Development of an enzyme-linked immunosorbent assay-based method for measuring galactosyltransferase activity using a synthetic glycopolymer acceptor substrate.

    Science.gov (United States)

    Oubihi, M; Kitajima, K; Kobayashi, K; Adachi, T; Aoki, N; Matsuda, T

    1998-03-15

    A lectin-assisted enzyme-linked immunosorbent assay (ELISA)-based method using a synthetic glycopolymer as an acceptor substrate was developed for measuring beta 1,4-galactosyltransferase (GalT) activity. A polyacrylamide derivative having a beta-linked N-acetylglucosamine (GlcNAc beta) moiety on each monomeric unit was synthesized chemically and immobilized on a polystyrene microtiter plate as an acceptor substrate for GalT. After the plate was incubated with bovine GalT, the enzyme reaction product, beta-linked Gal residue on the polyacrylamide-bound GlcNAc residue, was detected by using Ricinus communis agglutinin 1 (RCA1), rabbit anti-RCA1 antibody, and a peroxidase-labeled anti-rabbit IgG. The lowest GalT concentration detectable by this method was about 0.5 mU/ml, which is comparable to those by the previously reported ELISA-based assays. The unique property of the glycopolymer, PAP(GlcNAc beta), of binding noncovalently but tightly to the polystyrene microtiter plate allowed the use of this acceptor substrate for the GalT activity measurement even in the presence of 1% Triton CF-54 and X-100. Our system was successfully applied to assess GalT activity in milk of various mammals.

  1. Lagrangian modelling of ocean surface waves and synthetic aperture radar wave measurements

    Energy Technology Data Exchange (ETDEWEB)

    Fouques, Sebastien

    2005-07-01

    The present thesis is concerned with the estimation of the ocean wave spectrum from synthetic aperture radar imaging and the modelling of ocean surface waves using the Lagrangian formalism. The first part gives a short overview of the theories of ocean surface waves and synthetic aperture radar (SAR) whereas the second part consists of five independent publications. The first two articles investigate the influence of the radar backscatter model on the SAR imaging of ocean waves. In Article I, Monte Carlo simulations of SAR images of the ocean surface are carried out using a nonlinear backscatter model that include both specular reflection and Bragg scattering and the results are compared to simulations from the classical Hasselmann integral transform (Hasselmann and Hasselmann, 1991). It is shown that nonlinearities in the backscatter model strongly influence the imaging of range-travelling waves and that the former can suppress the range-splitting effect (Bruning et al., 1988). Furthermore, in Article II a database of Envisat-ASAR Wave Mode products co-located with directional wave spectra from the numerical model WAM and which contains range-travelling wave cases only, is set up. The WAM spectra are used as input to several ocean-to-SAR integral transforms, with various real aperture radar (RAR) models and the obtained SAR image cross-spectra are compared to the Envisat-ASAR observations. A first result is that the use of a linear backscatter model leads to a high proportion of non-physical negative backscatter values in the RAR image, as suggested by Schulz-Stellenfleth (2001). Then, a comparison between the observed SAR cross-spectra and the ones simulated through Hasselmann's integral transform reveals that only twenty percents of the observations show a range-splitting effect as strong as in the simulations. A much better agreement is obtained when using the integral transform by Schulz-Stellenfleth (2003), which is based on a nonlinear hackscatter model

  2. Comparison of 3D Synthetic Aperture Imaging and Explososcan using Phantom Measurements

    DEFF Research Database (Denmark)

    Rasmussen, Morten Fischer; Férin, Guillaume; Dufait, Rémi

    2012-01-01

    by using tissue and wire phantom measurements. The measurements are carried out using a 1024 element 2D transducer and the 1024 channel experimental ultrasound scanner SARUS. To make a fair comparison, the two imaging techniques use the same number of active channels, the same number of emissions per frame...... of Explososcan. From wire phantom measurements the point spread functions of both techniques were measured. At 40mm depth Explososcan achieves a main lobe width (FWHM) of 2.5mm while SAI’s FWHM is 2.2 mm. At 80mm the FWHM is 5.2mm for Explososcan and 3.4mm for SAI, which is a difference of 35 %. Another metric...

  3. 1,5-Anhydro-D-fructose: biocatalytic and chemical synthetic methods for the preparation, transformation and derivatization

    DEFF Research Database (Denmark)

    Lundt, Inge; Yu, Shukun

    2010-01-01

    1,5-Anhydro-D-fructose (1,5AnFru) is a monoketosaccharide that can be prepared enzymatically from starch by a-1,4-glucan lyase or chemically from D-glucose or D-fructose in a few steps with high yields. The formed 1,5AnFru can be derivatized both enzymatically and chemically to interesting new ca...... like 1-deoxymannonojirimycin and Clavulazine. 1,5AnFru disaccharides (glycosyl 1?4 1,5AnFru) have been prepared as well as glycosyl 1?4 1,5-anhydro-D-tagatose....

  4. Hazard Assessment of Chemical Air Contaminants Measured in Residences

    Energy Technology Data Exchange (ETDEWEB)

    Logue, J.M.; McKone, T.E.; Sherman, M. H.; Singer, B.C.

    2010-05-10

    Identifying air pollutants that pose a potential hazard indoors can facilitate exposure mitigation. In this study, we compiled summary results from 77 published studies reporting measurements of chemical pollutants in residences in the United States and in countries with similar lifestyles. These data were used to calculate representative mid-range and upper bound concentrations relevant to chronic exposures for 267 pollutants and representative peak concentrations relevant to acute exposures for 5 activity-associated pollutants. Representative concentrations are compared to available chronic and acute health standards for 97 pollutants. Fifteen pollutants appear to exceed chronic health standards in a large fraction of homes. Nine other pollutants are identified as potential chronic health hazards in a substantial minority of homes and an additional nine are identified as potential hazards in a very small percentage of homes. Nine pollutants are identified as priority hazards based on the robustness of measured concentration data and the fraction of residences that appear to be impacted: acetaldehyde; acrolein; benzene; 1,3-butadiene; 1,4-dichlorobenzene; formaldehyde; naphthalene; nitrogen dioxide; and PM{sub 2.5}. Activity-based emissions are shown to pose potential acute health hazards for PM{sub 2.5}, formaldehyde, CO, chloroform, and NO{sub 2}.

  5. Chemical Carcinogen (Hydrazine, Polynuclear Hydrocarbon and/or Synthetic Jet Fuel Components) Induced Carcinogenesis of Human Cells, In Vitro

    Science.gov (United States)

    1981-08-01

    Helth John Donance, Inge Noyes, Steven Weisbrode, Dorothy Seaumm and r * :.,rol .na Z�. George Milo. Depts of Physiological Chemistry, Veterinary Ii...With the current technology to transform human cells in vitro with physical carcinogens and chemical carcinogens we can now evaluate the neoplastic

  6. Chemical recycling of carbon dioxide to methanol and dimethyl ether: from greenhouse gas to renewable, environmentally carbon neutral fuels and synthetic hydrocarbons.

    Science.gov (United States)

    Olah, George A; Goeppert, Alain; Prakash, G K Surya

    2009-01-16

    Nature's photosynthesis uses the sun's energy with chlorophyll in plants as a catalyst to recycle carbon dioxide and water into new plant life. Only given sufficient geological time can new fossil fuels be formed naturally. In contrast, chemical recycling of carbon dioxide from natural and industrial sources as well as varied human activities or even from the air itself to methanol or dimethyl ether (DME) and their varied products can be achieved via its capture and subsequent reductive hydrogenative conversion. The present Perspective reviews this new approach and our research in the field over the last 15 years. Carbon recycling represents a significant aspect of our proposed Methanol Economy. Any available energy source (alternative energies such as solar, wind, geothermal, and atomic energy) can be used for the production of needed hydrogen and chemical conversion of CO(2). Improved new methods for the efficient reductive conversion of CO(2) to methanol and/or DME that we have developed include bireforming with methane and ways of catalytic or electrochemical conversions. Liquid methanol is preferable to highly volatile and potentially explosive hydrogen for energy storage and transportation. Together with the derived DME, they are excellent transportation fuels for internal combustion engines (ICE) and fuel cells as well as convenient starting materials for synthetic hydrocarbons and their varied products. Carbon dioxide thus can be chemically transformed from a detrimental greenhouse gas causing global warming into a valuable, renewable and inexhaustible carbon source of the future allowing environmentally neutral use of carbon fuels and derived hydrocarbon products.

  7. Chemical composition and in vitro digestibility of whole-crop maize fertilized with synthetic fertilizer or digestate and harvested at two maturity stages in Boreal growing conditions

    Directory of Open Access Journals (Sweden)

    Mahmoud F. Seleiman

    2017-04-01

    Full Text Available Maize cultivation for silage could be a sustainable option in Boreal conditions, especially when combined with nutrient recycling. Effects of digestate (sludge from biogas of domestic origin application in comparison with synthetic fertilizer and two maturity stages on chemical composition and in vitro digestibility of whole-crop maize were investigated. Starch, neutral detergent fiber, water soluble carbohydrate (WSC and digestible organic matter (DOM contents of maize did not differ in response to the two fertilizer treatments. However, starch, DOM and metabolizable energy of maize increased, while ash, crude protein and WSC contents decreased with increasing maize maturity. Heavy metals in maize fertilized with digestate remained low. The results indicate that whole-crop maize fertilized with digestate and harvested at 150 days after sowing is a promising feed and has good nutritive value, even in Boreal conditions.

  8. 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

    Directory of Open Access Journals (Sweden)

    Katarzyna Adamala

    2014-02-01

    We have recently addressed these questions by using a chemical synthetic biology approach. In particular, we have tested the catalytic activity of small peptides, like Ser-His, with respect to peptide- and nucleotides-condensation, as a realistic model of primitive organocatalysis. We have also set up a strategy for exploring the sequence space of random proteins and RNAs (the so-called “never born biopolymer” project with respect to the production of folded structures. Being still far from solved, the main aspects of these “open questions” are discussed here, by commenting on recent results obtained in our groups and by providing a unifying view on the problem and possible solutions. In particular, we propose a general scenario for macromolecule formation via fragment-condensation, as a scheme for the emergence of specific sequences based on molecular growth and selection.

  9. CHEMICALS

    CERN Multimedia

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  10. A Tailor-Made Synthetic Polymer for Cell Encapsulation: Design Rationale, Synthesis, Chemical-Physics and Biological Characterizations.

    Science.gov (United States)

    Gerges, Irini; Tamplenizza, Margherita; Rossi, Eleonora; Tocchio, Alessandro; Martello, Federico; Recordati, Camilla; Kumar, Deepak; Forsyth, Nicholas R; Liu, Yang; Lenardi, Cristina

    2016-06-01

    This study presents a custom-made in situ gelling polymeric precursor for cell encapsulation. Composed of poly((2-hydroxyethyl)methacrylate-co-(3-aminopropyl)methacrylamide) (P(HEMA-co-APM) mother backbone and RGD-mimicking poly(amidoamine) (PAA) moiteis, the comb-like structured polymeric precursor is tailored to gather the advantages of the two families of synthetic polymers, i.e., the good mechanical integrity of PHEMA-based polymers and the biocompatibility and biodegradability of PAAs. The role of P(HEMA-co-APM) in the regulation of the chemico-physical properties of P(HEMA-co-APM)/PAA hydrogels is thoroughly investigated. On the basis of obtained results, namely the capability of maintaining vital NIH3T3 cell line in vitro for 2 d in a 3D cell culture, the in vivo biocompatibility in murine model for 16 d, and the ability of finely tuning mechanical properties and degradation kinetics, it can be assessed that P(HEMA-co-APM)/PAAs offer a cost-effective valid alternative to the so far studied natural polymer-based systems for cell encapsulation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. A synthetic aperture microwave radiometer to measure soil moisture and ocean salinity from space

    Science.gov (United States)

    Le Vine, D. M.; Hilliard, L. M.; Swift, C. T.; Ruf, C. S.; Garrett, L. B.

    1991-01-01

    A concept is presented for a microwave radiometer in space to measure soil moisture and ocean salinity as part of an 'Earth Probe' mission. The measurements could be made using an array of stick antennas. The L-band channel (1.4 GHz) would be the primary channel for determining soil moisture, with the S-band (2.65-GHz) and C-band (5.0-GHz) channels providing ancillary information to help correct for the effects of the vegetation canopy and possibly to estimate a moisture profile. A preliminary study indicates that an orbit at 450 km would provide coverage of better than 95 percent of the earth every 3 days. A 10-km resolution cell (at nadir) requires stick antennas about 9.5-m long at L-band. The S-band and C-band sticks would be substantially shorter (5 m and 2.7 m, respectively).

  12. SimShiftDB; local conformational restraints derived from chemical shift similarity searches on a large synthetic database

    International Nuclear Information System (INIS)

    Ginzinger, Simon W.; Coles, Murray

    2009-01-01

    We present SimShiftDB, a new program to extract conformational data from protein chemical shifts using structural alignments. The alignments are obtained in searches of a large database containing 13,000 structures and corresponding back-calculated chemical shifts. SimShiftDB makes use of chemical shift data to provide accurate results even in the case of low sequence similarity, and with even coverage of the conformational search space. We compare SimShiftDB to HHSearch, a state-of-the-art sequence-based search tool, and to TALOS, the current standard tool for the task. We show that for a significant fraction of the predicted similarities, SimShiftDB outperforms the other two methods. Particularly, the high coverage afforded by the larger database often allows predictions to be made for residues not involved in canonical secondary structure, where TALOS predictions are both less frequent and more error prone. Thus SimShiftDB can be seen as a complement to currently available methods

  13. Using X-band Weather Radar Measurements to Monitor the Integrity of Digital Elevation Models for Synthetic Vision Systems

    Science.gov (United States)

    Young, Steve; UijtdeHaag, Maarten; Sayre, Jonathon

    2003-01-01

    Synthetic Vision Systems (SVS) provide pilots with displays of stored geo-spatial data representing terrain, obstacles, and cultural features. As comprehensive validation is impractical, these databases typically have no quantifiable level of integrity. Further, updates to the databases may not be provided as changes occur. These issues limit the certification level and constrain the operational context of SVS for civil aviation. Previous work demonstrated the feasibility of using a realtime monitor to bound the integrity of Digital Elevation Models (DEMs) by using radar altimeter measurements during flight. This paper describes an extension of this concept to include X-band Weather Radar (WxR) measurements. This enables the monitor to detect additional classes of DEM errors and to reduce the exposure time associated with integrity threats. Feature extraction techniques are used along with a statistical assessment of similarity measures between the sensed and stored features that are detected. Recent flight-testing in the area around the Juneau, Alaska Airport (JNU) has resulted in a comprehensive set of sensor data that is being used to assess the feasibility of the proposed monitor technology. Initial results of this assessment are presented.

  14. Measurement of chemical sputtering yields of various types of carbon

    International Nuclear Information System (INIS)

    Yamada, R.; Nakamura, K.; Sone, K.; Saidoh, M.

    1980-01-01

    The methane formation from carbon due to the bombardment with hydrogen ions has been studied. The influences of the dose of incident ions and the types of carbon on methane production rate under the careful pretreatment of carbon are described in this paper. The incident energy of the hydrogen ions used was in the range from 0.1 to 6 keV for the purpose of filling the lack of the chemical sputtering coefficient for low energy hydrogen ions. The samples used were two kinds of pyrolytic graphite. Both basal and edge planes which were cut perpendicularly and in parallel to c-axis, respectively, were used as the surfaces of targets for the bombardment with H + ions. Other kinds of carbon used were isotropic atomic grade graphite and glassy carbon. A quadrupole mass spectrometer was used for the measurement of the methane formation. The methane production rate increased with dose, and gradually reached a constant value. The samples which were pre-bombarded with hydrogen ions showed the very different dose dependence of methane production rate. The anomalous rate can be explained by the particle-induced desorption of super-saturated hydrogen concentration in the target. The energy and temperature dependences of the methane production rate were almost same for the various carbon materials. (Kato, T.)

  15. Prenatal exposures to perfluorinated chemicals and anthropometric measures in infancy

    DEFF Research Database (Denmark)

    Andersen, Camilla Schou; Fei, Chunyuan; Gamborg, Michael

    2010-01-01

    Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) are persistent chemicals that may affect growth early in life. The authors estimated the associations between maternal plasma levels of PFOS and PFOA and infants' weight, length, and body mass index development during the first year....... Multiple linear regression models were used for analyses, and maternal PFOS and PFOA concentrations (ng/mL) were inversely related to children's weight in the first year of life: adjusted regression coefficients: -1.1 g (95% confidence interval (CI): -4.6, 2.3) at 5 months and -5.8 g (95% CI: -10.4, -1.......2) at 12 months for PFOS; -10.6 g (95% CI: -30.2, 8.9) at 5 months and -19.7 g (95% CI: -45.9, 6.5) at 12 months for PFOA. A similar pattern was observed for body mass index measurements, and no associations with length were found. After sex stratification, the inverse associations with weight and body...

  16. Prediction of Wine Sensorial Quality by Routinely Measured Chemical Properties

    Directory of Open Access Journals (Sweden)

    Bednárová Adriána

    2014-12-01

    Full Text Available The determination of the sensorial quality of wines is of great interest for wine consumers and producers since it declares the quality in most of the cases. The sensorial assays carried out by a group of experts are time-consuming and expensive especially when dealing with large batches of wines. Therefore, an attempt was made to assess the possibility of estimating the wine sensorial quality with using routinely measured chemical descriptors as predictors. For this purpose, 131 Slovenian red wine samples of different varieties and years of production were analysed and correlation and principal component analysis were applied to find inter-relations between the studied oenological descriptors. The method of artificial neural networks (ANNs was utilised as the prediction tool for estimating overall sensorial quality of red wines. Each model was rigorously validated and sensitivity analysis was applied as a method for selecting the most important predictors. Consequently, acceptable results were obtained, when data representing only one year of production were included in the analysis. In this case, the coefficient of determination (R2 associated with training data was 0.95 and that for validation data was 0.90. When estimating sensorial quality in categorical form, 94 % and 85 % of correctly classified samples were achieved for training and validation subset, respectively.

  17. Electron microscopic and physico-chemical studies of DNA complexes with synthetic oligopeptides: binding specificity and DNA compact structures.

    Science.gov (United States)

    Vengerov, Y Y; Semenov, T E; Surovaya, A N; Sidorova NYu; Streltsov, S A; Khorlin, A A; Zhuze, A L; Gursky, G V

    1988-10-01

    Binding to DNA of two synthetic peptides, Val-Thr-Thr-Val-Val-NH-NH-Dns and Thr-Val-Thr-Lys-Val-Gly-Thr-Lsy-Val-Gly-Thr-Val-Val-NH-NH-Dns (where Dns is a residue of 5-dimethylaminonaphthalene-1-sulfonic acid), has been studied by circular dichroism, electron microscopy and fluorescence methods. It has been found that these two peptides can self-associate in aqueous solution as follows from the fact that concentration-dependent changes are observed in the UV absorbance and fluorescence spectra. The two peptides can bind to DNA both in self-associated and monomeric forms. The pentapeptide in the beta-associated form binds more strongly to poly(dG).poly(dC) than to poly[d(A-C)].poly[d(G-T)] and poly(dA).poly(dT) whereas the tridecapeptide exhibits an opposite order of preferences binding more strongly to poly[d(A-C)].poly[d(G-T)] and poly(dA).poly(dT) than to poly(dG).poly(dC). Binding is a cooperative process which is accompanied by the DNA compaction at peptide/DNA base pair ratios greater than 1. At the initial stage of the compaction process, the coalescence of DNA segments covered by bound peptide molecules leads to the formation of DNA loops stabilized by the interaction between peptide molecules bound to different DNA segments. Further increase in the peptide/DNA ratio leads to the formation of rod-like structures each consisting of two or more double-stranded DNA segments. The final stage of the compaction process involves folding of fibrillar macromolecular complexes into a globular structure containing only one DNA molecule.

  18. Synthetic hematocrit derived from the longitudinal relaxation of blood can lead to clinically significant errors in measurement of extracellular volume fraction in pediatric and young adult patients.

    Science.gov (United States)

    Raucci, Frank J; Parra, David A; Christensen, Jason T; Hernandez, Lazaro E; Markham, Larry W; Xu, Meng; Slaughter, James C; Soslow, Jonathan H

    2017-08-02

    Extracellular volume fraction (ECV) is altered in pathological cardiac remodeling and predicts death and arrhythmia. ECV can be quantified using cardiovascular magnetic resonance (CMR) T1 mapping but calculation requires a measured hematocrit (Hct). The longitudinal relaxation of blood has been used in adults to generate a synthetic Hct (estimate of true Hct) but has not been validated in pediatric populations. One hundred fourteen children and young adults underwent a total of 163 CMRs with T1 mapping. The majority of subjects had a measured Hct the same day (N = 146). Native and post-contrast T1 were determined in blood pool, septum, and free wall of mid-LV, avoiding areas of late gadolinium enhancement. Synthetic Hct and ECV were calculated and intraclass correlation coefficient (ICC) and linear regression were used to compare measured and synthetic values. The mean age was 16.4 ± 6.4 years and mean left ventricular ejection fraction was 59% ± 9%. The mean measured Hct was 41.8 ± 3.0% compared to the mean synthetic Hct of 43.2% ± 2.9% (p measured mid-free wall ECV was 30.5% ± 4.8% and mean synthetic mid-free wall ECV of local model was 29.7% ± 4.6% (p measured and synthetic ECV ranged from -8.4% to 4.3% in the septum and -12.6% to 15.8% in the free wall. Using our laboratory's normal cut-off of 28.5%, 59 patients (37%) were miscategorized (53 false negatives, 6 false positives) with published model ECV. The local model had 37 miscategorizations (20 false negatives, 17 false positives), significantly fewer but still a substantial number (23%). Our data suggest that use of synthetic Hct for the calculation of ECV results in miscategorization of individual patients. This difference may be less significant once synthetic ECV is calculated and averaged over a large research cohort, making it potentially useful as a research tool. However, we recommend formal measurement of Hct in children and young adults for clinical CMRs.

  19. Spatial response of synthetic microDiamond and diode detectors measured with kilovoltage synchrotron radiation.

    Science.gov (United States)

    Butler, Duncan J; Beveridge, Toby; Lehmann, Joerg; Oliver, Christopher P; Stevenson, Andrew W; Livingstone, Jayde

    2018-02-01

    To map the spatial response of four solid-state radiation detectors of types commonly used for radiotherapy dosimetry. PTW model 60016 Diode P, 60017 Diode E, 60018 Diode SRS, and 60019 microDiamond detectors were radiographed using a high resolution conventional X-ray system. Their spatial response was then investigated using a 0.1 mm diameter beam of 95 keV average energy photons generated by a synchrotron. The detectors were scanned through the beam while their signal was recorded as a function of position, to map the response. These 2D response maps were created in both the end-on and side-on orientations. The results show the location and size of the active region. End-on, the active area was determined to be centrally located and within 0.2 mm of the manufacturer's specified diameter. The active areas of the 60016 Diode P, 60017 Diode E, 60018 Diode SRS detectors are uniform to within approximately 5%. The 60019 microDiamond showed local variations up to 30%. The extra-cameral signal in the microDiamond was calculated from the side-on scan to be approximately 8% of the signal from the active element. The spatial response of four solid-state detectors has been measured. The technique yielded information about the location and uniformity of the active area, and the extra-cameral signal, for the beam quality used. © 2017 Commonwealth of Australia. Medical Physics © 2017 American Association of Physicists in Medicine. This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced without prior written permission. Requests and enquiries concerning reproduction and rights should be directed in the first instance to John Wiley & Sons Ltd of The Atrium, Southern Gate, Chichester, West Sussex P019 8SQ UNITED KINGDOM; alternatively to ARPANSA.

  20. Method validation and measurement uncertainty for the simultaneous determination of synthetic phenolic antioxidants in edible oils commonly consumed in Korea.

    Science.gov (United States)

    Kim, Jae-Min; Choi, Seung-Hyun; Shin, Gi-Hae; Lee, Jin-Ha; Kang, Seong-Ran; Lee, Kyun-Young; Lim, Ho-Soo; Kang, Tae Seok; Lee, Ok-Hwan

    2016-12-15

    This study investigated a method for the validation and determination of measurement uncertainty for the simultaneous determination of synthetic phenolic antioxidants (SPAs) such as propyl gallate (PG), octyl gallate (OG), dodecyl gallate (DG), 2,4,5-trihydroxy butyrophenone (THBP), tert-butylhydroquinone (TBHQ), butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT) in edible oils commonly consumed in Korea. The validated method was able to extract SPA residues under the optimized HPLC-UV and LC-MS/MS conditions. Furthermore, the measurement of uncertainty was evaluated based on the precision study. For HPLC-UV analysis, the recoveries of SPAs ranged from 91.4% to 115.9% with relative standard deviations between 0.3% and 11.4%. In addition, the expanded uncertainties of the SPAs ranged from 0.15 to 5.91. These results indicate that the validated method is appropriate for the extraction and determination of SPAs and can be used to verify the safety of edible oil products containing SPAs residues. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Forecasting slope failures from space-based synthetic aperture radar (SAR) measurements

    Science.gov (United States)

    Wasowski, J.; Bovenga, F.; Nutricato, R.; Nitti, D. O.; Chiaradia, M. T.; Tijani, K.; Morea, A.

    2017-12-01

    New space-borne radar sensors enable multi-scale monitoring of potentially unstable slopes thanks to wide-area coverage (tens of thousands km2), regular long-term image acquisition schedule with increasing re-visit frequency (weekly to daily), and high measurement precision (mm). In particular, the recent radar satellite missions e.g., COSMO-SkyMed (CSK), Sentinel-1 (S-1) and improved multi-temporal interferometry (MTI) processing techniques allow timely delivery of information on slow ground surface displacements. Here we use two case study examples to show that it is possible to capture pre-failure slope strains through long-term MTI-based monitoring. The first case is a retrospective investigation of a huge 500ML m3 landslide, which occurred in Sept. 2016 in a large, active open-cast coal mine in central Europe. We processed over 100 S-1 images acquired since Fall 2014. The MTI results showed that the slope that failed had been unstable at least since 2014. Importantly, we detected consistent displacement trends and trend changes, which can be used for slope failure forecasting. Specifically, we documented significant acceleration in slope surface displacement in the two months preceding the catastrophic failure. The second case of retrospectively captured pre-failure slope strains regards our earlier study of a small 50 m long landslide, which occurred on Jan. 2014 and caused the derailment of a train on the railway line connecting NW Italy to France. We processed 56 CSK images acquired from Fall 2008 to Spring 2014. The MTI results revealed pre-failure displacements of the engineering structures on the slope subsequently affected by the 2014 slide. The analysis of the MTI time series further showed that the displacements had been occurring since 2009. This information could have been used to forewarn the railway authority about the slope instability hazard. The above examples indicate that more frequent and consistent image acquisitions by the new radar

  2. Simultaneous incorporation of carbonate and fluoride in synthetic apatites: Effect on crystallographic and physico-chemical properties.

    Science.gov (United States)

    Yao, Fang; LeGeros, John P; LeGeros, Racquel Z

    2009-07-01

    The mineral in bone is an impure hydroxyapatite, with carbonate as the chief minor substituent. Fluoride has been shown to stimulate osteoblastic activity and inhibit osteoclastic resorption in vitro. CO(3)- and F-substituted apatite (CFA) has been considered as potential bone graft material for orthopedic and dental applications. The objective of this study was to determine the effects of simultaneously incorporated CO(3) and F on the crystallographic physico-chemical properties of apatite. The results showed that increasing CO(3) and Na content in apatites with relatively constant F concentration caused a decrease in crystallite size and an increase in the extent of calcium release; increasing F content in apatites with relatively constant CO(3) concentration caused an increase in crystallite size and a decrease in the extent of Ca release. These findings suggest that CFAs as bone graft materials of desired solubility can be prepared by manipulating the relative concentrations of CO(3) and F incorporated in the apatite.

  3. UV radiation, vitamin D, and cancer: how to measure the vitamin D synthetic capacity of UV sources?

    Science.gov (United States)

    Terenetskaya, Irina; Orlova, Tatiana

    2005-09-01

    UV irradiation is widely used in phototherapy. Regardless of the fact that UV overexposure is liable to cause adverse health effect, in appropriate doses UV radiation initiates synthesis of vitamin D in skin that is absolutely essential for human health. As it proved, most people in northern industrial countries have a level of vitamin D in their bodies that is insufficient for optimum health, especially in winter. These low levels of vitamin D are now known to be associated with a wide spectrum of serious disease much of which leads on to premature death. The diseases associated with D deficiency involve more than a dozen types of cancer including colon, breast and prostate, as well as the classic bone diseases: rickets, osteoporosis and osteomalacia. Irradiation with artificial UV sources can prevent the vitamin D deficiency. However, in view of different irradiation spectra of UV lamps, their ability to initiate vitamin D synthesis is different. The reliable method based on an in vitro model of vitamin D synthesis has been developed for direct measurement in situ of the vitamin D synthetic capacity of artificial UV sources during a phototherapeutic procedure

  4. GIS-Based Synthetic Measurement of Sustainable Development in Loess Plateau Ecologically Fragile Area—Case of Qingyang, China

    Directory of Open Access Journals (Sweden)

    Chenyu Lu

    2015-02-01

    Full Text Available Synthetic measurement of regional sustainable development has been one of the key issues in the research field of sustainability. In this paper, Qingyang City located in the Loess Plateau ecologically fragile area of Northwest China is used for a case study, and the present study aims to investigate the degree of sustainable development by conducting temporal- and spatial-scale based analysis, with the assessment index system, assessment model and GIS approach well integrated. The results show that the development pattern of Qingyang generally fits the mode of unsustainable development, even in the presence of certain levels of spatial differences. The sustainable development state in ecologically fragile area of China’s Loess Plateau is non-optimistic, which is an uncoordinated status among subsystems of regional sustainable development. Although the level and tendency of regional sustainable development keeps increasing, such enhancement is abnormal. With the rapid deterioration of environmental and natural resources, their inhibitory effect on the economy and society would expand, eventually leading to the slow development rate or the recession of the entire system. The only solution is to change the traditional mode of economic development, to follow the guide of ecological economic conception so that the goal of achieving regional sustainable development strategies could be met ultimately. Meanwhile, the characteristics of different regions should be taken into account in order to achieve optimal spatial structure.

  5. Measurement standards and the general problem of reference points in chemical analysis

    International Nuclear Information System (INIS)

    Richter, W.; Dube, G.

    2002-01-01

    Besides the measurement standards available in general metrology in the form of the realisations of the units of measurement, measurement standards of chemical composition are needed for the vast field of chemical measurement (measurements of the chemical composition), because it is the main aim of such measurements to quantify non-isolated substances, often in complicated matrices, to which the 'classical' measurement standards and their lower- level derivatives are not directly applicable. At present, material artefacts as well as standard measurement devices serve as chemical measurement standards. These are measurement standards in the full metrological sense only, however, if they are firmly linked to the SI unit in which the composition represented by the standard is expressed. This requirement has the consequence that only a very restricted number of really reliable chemical measurement standards exist at present. Since it is very difficult and time consuming to increase this number substantially and, on the other hand, reliable reference points are increasingly needed for all kinds of chemical measurements, primary methods of measurement and high-level reference measurements will play an increasingly important role for the establishment of worldwide comparability and hence mutual acceptance of chemical measurement results. (author)

  6. Measurement of Hepatic Protein Fractional Synthetic Rate with Stable Isotope Labeling Technique in Thapsigargin Stressed HepG2 Cells

    Science.gov (United States)

    Song, Juquan; Zhang, Xiao-jun; Boehning, Darren; Brooks, Natasha C.; Herndon, David N.; Jeschke, Marc G.

    2012-01-01

    Severe burn-induced liver damage and dysfunction is associated with endoplasmic reticulum (ER) stress. ER stress has been shown to regulate global protein synthesis. In the current study, we induced ER stress in vitro and estimated the effect of ER stress on hepatic protein synthesis. The aim was two-fold: (1) to establish an in vitro model to isotopically measure hepatic protein synthesis and (2) to evaluate protein fractional synthetic rate (FSR) in response to ER stress. Human hepatocellular carcinoma cells (HepG2) were cultured in medium supplemented with stable isotopes 1,2-13C2-glycine and L-[ring-13C6]phenylalanine. ER stress was induced by exposing the cells to 100 nM of thapsigargin (TG). Cell content was collected from day 0 to 14. Alterations in cytosolic calcium were measured by calcium imaging and ER stress markers were confirmed by Western blotting. The precursor and product enrichments were detected by GC-MS analysis for FSR calculation. We found that the hepatic protein FSR were 0.97±0.02 and 0.99±0.05%/hr calculated from 1,2-13C2-glycine and L-[ring-13C6]phenylalanine, respectively. TG depleted ER calcium stores and induced ER stress by upregulating p-IRE-1 and Bip. FSR dramatically decreased to 0.68±0.03 and 0.60±0.06%/hr in the TG treatment group (pisotope tracer incorporation technique is a useful method for studying the effects of ER stress on hepatic protein synthesis. PMID:22298954

  7. 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

  8. One-step green synthetic approach for the preparation of multicolor emitting copper nanoclusters and their applications in chemical species sensing and bioimaging.

    Science.gov (United States)

    Bhamore, Jigna R; Jha, Sanjay; Mungara, Anil Kumar; Singhal, Rakesh Kumar; Sonkeshariya, Dhanshri; Kailasa, Suresh Kumar

    2016-06-15

    One-step green microwave synthetic approach was developed for the synthesis of copper nanoclusters (Cu NCs) and used as a fluorescent probe for the sensitive detection of thiram and paraquat in water and food samples. Unexpectedly, the prepared Cu NCs exhibited strong orange fluorescence and showed emission peak at 600 nm, respectively. Under optimized conditions, the quenching of Cu NCs emission peak at 600 nm was linearly proportional to thiram and paraquat concentrations in the ranges from 0.5 to 1000 µM, and from 0.2 to 1000 µM, with detection limits of 70 nM and 49 nM, respectively. In addition, bioimaging studies against Bacillus subtilis through confocal fluorescence microscopy indicated that Cu NCs showed strong blue and green fluorescence signals, good permeability and minimum toxicity against the various bacteria species, which demonstrates their potential feasibility for chemical species sensing and bioimaging applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. A pilot scale trickling filter with pebble gravel as media and its performance to remove chemical oxygen demand from synthetic brewery wastewater.

    Science.gov (United States)

    Habte Lemji, Haimanot; Eckstädt, Hartmut

    2013-10-01

    Evaluating the performance of a biotrickling filter for the treatment of wastewaters produced by a company manufacturing beer was the aim of this study. A pilot scale trickling filter filled with gravel was used as the experimental biofilter. Pilot scale plant experiments were made to evaluate the performance of the trickling filter aerobic and anaerobic biofilm systems for removal of chemical oxygen demand (COD) and nutrients from synthetic brewery wastewater. Performance evaluation data of the trickling filter were generated under different experimental conditions. The trickling filter had an average efficiency of (86.81±6.95)% as the hydraulic loading rate increased from 4.0 to 6.4 m(3)/(m(2)∙d). Various COD concentrations were used to adjust organic loading rates from 1.5 to 4.5 kg COD/(m(3)∙d). An average COD removal efficiency of (85.10±6.40)% was achieved in all wastewater concentrations at a hydraulic loading of 6.4 m(3)/(m(2)∙d). The results lead to a design organic load of 1.5 kg COD/(m(3)∙d) to reach an effluent COD in the range of 50-120 mg/L. As can be concluded from the results of this study, organic substances in brewery wastewater can be handled in a cost-effective and environmentally friendly manner using the gravel-filled trickling filter.

  10. What Are Synthetic Cannabinoids?

    Science.gov (United States)

    ... market and are intended to produce the same effects as illegal drugs. Some of these substances may have been around for years but have reentered the market in altered chemical forms, or due to renewed popularity. False Advertising Synthetic cannabinoid products are often labeled "not for ...

  11. Measurement of Lung Cancer Tumor Markers in a Glass Wool Company Workers Exposed to Respirable Synthetic Vitreous Fiber and Dust

    Directory of Open Access Journals (Sweden)

    Shabnam Abtahi

    2018-01-01

    Full Text Available Background: Occupational exposures to respirable synthetic vitreous fiber (SVF and dust are associated with many lung diseases including lung cancer. Low-dose computed tomography is used for screening patients who are highly suspicious of having lung carcinoma. However, it seems not to be cost-effective. Serum biomarkers could be a useful tool for the surveillance of occupational exposure, by providing the possibility of diagnosing lung cancer in its early stages. Objective: To determine if serum carcinoembryonic antigen (CEA and cytokeratin fragment (CYFRA 21-1 levels in workers exposed more than normal population to respirable SVF and dust may be used as indicators of progression towards lung cancer. Methods: An analytic cross-sectional study, including 145 personnel of a glass wool company, along with 25 age-matched healthy individuals, was conducted to investigate the relationship between occupational exposure to respirable SVFs and dust and serum levels of two lung/pleura serum tumor markers, CEA and CYFRA 21-1, measured by ELISA. Results: Individuals exposed to higher than the recommended levels of respirable SVF had higher serum concentrations of CEA and CYFRA 21-1, compared to controls (p=0.008 and 0.040, respectively, as well as in comparison to those exposed to lower than recommended OSHA levels (p=0.046 and 0.033, respectively. Workers with >9 years work experience, had significantly (p=0.045 higher levels of serum CYFRA 21-1 than those with ≤9 years of experience. Conclusion: It seems that working for >9 years in sites with detectable levels of respirable SVF and dust would increase the levels of known lung cancer serum tumor markers. Transferring these workers to sites with respirable SVF concentrations lower than the limit of detection in the air is recommended.

  12. Prenatal exposures to perfluorinated chemicals and anthropometric measures in infancy

    DEFF Research Database (Denmark)

    Andersen, Camilla Schou; Fei, Chunyuan; Gamborg, Michael

    2010-01-01

    Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) are persistent chemicals that may affect growth early in life. The authors estimated the associations between maternal plasma levels of PFOS and PFOA and infants' weight, length, and body mass index development during the first year....... Multiple linear regression models were used for analyses, and maternal PFOS and PFOA concentrations (ng/mL) were inversely related to children's weight in the first year of life: adjusted regression coefficients: -1.1 g (95% confidence interval (CI): -4.6, 2.3) at 5 months and -5.8 g (95% CI: -10.4, -1...

  13. Synthetic biology: lessons from the history of synthetic organic chemistry.

    Science.gov (United States)

    Yeh, Brian J; Lim, Wendell A

    2007-09-01

    The mid-nineteenth century saw the development of a radical new direction in chemistry: instead of simply analyzing existing molecules, chemists began to synthesize them--including molecules that did not exist in nature. The combination of this new synthetic approach with more traditional analytical approaches revolutionized chemistry, leading to a deep understanding of the fundamental principles of chemical structure and reactivity and to the emergence of the modern pharmaceutical and chemical industries. The history of synthetic chemistry offers a possible roadmap for the development and impact of synthetic biology, a nascent field in which the goal is to build novel biological systems.

  14. Exploration of the topology of chemical spaces with network measures.

    Science.gov (United States)

    Krein, Michael P; Sukumar, N

    2011-11-17

    Discontinuous changes in molecular structure (resulting from continuous transformations of molecular coordinates) lead to changes in chemical properties and biological activities that chemists attempt to describe through structure-activity or structure-property relationships (QSAR/QSPR). Such relationships are commonly envisioned in a continuous high-dimensional space of numerical descriptors, referred to as chemistry space. The choice of descriptors defining coordinates within chemistry space and the choice of similarity metrics thus influence the partitioning of this space into regions corresponding to local structural similarity. These are the regions (known as domains of applicability) most likely to be successfully modeled by a structure-activity relationship. In this work the network topology and scaling relationships of chemistry spaces are first investigated independent of a specific biological activity. Chemistry spaces studied include the ZINC data set, a qHTS PubChem bioassay, as well as the space of protein binding sites from the PDB. The characteristics of these networks are compared and contrasted with those of the bioassay SALI subnetwork, which maps discontinuities or cliffs in the structure-activity landscape. Mapping the locations of activity cliffs and comparing the global characteristics of SALI subnetworks with those of the underlying chemistry space networks generated using different representations, can guide the choice of a better representation. A higher local density of SALI edges with a particular representation indicates a more challenging structure-activity relationship using that fingerprint in that region of chemistry space.

  15. Emittance Measurements at the Langley Chemical Physics Laboratory

    Science.gov (United States)

    Lewis, B. W.

    1960-01-01

    Total hemispherical emittance measurements are made routinely for materials which may be heated by electrical resistance methods over the temperature range of 600 degrees to 2,000 F by using a black-body reference method. This employs a conical black body and a thermopile detector with a calcium fluoride lens. Emittance is obtained by measuring the radiant flux from the specimen strip and comparing it with the flux from an equal area of the black-body cone at the same temperature. The temperature measurements are made by use of thermocouples. It is planned to extend the temperature range of this type of measurement to temperatures above 2,000 F. Another technique has been investigated for measuring emittance of materials not amenable to electrical heating or thermocouple attachment. This method uses a black-body-cavity furnace similar to that used in reference 5 to measure emittance of transparent materials such as glass. The method employs a heated black-body cavity in which the semicircular specimen is allowed to come to the equilibrium temperature of the cavity and then is rotated in front of a water-cooled viewing port where a sensitive thermistor detector alternately views the specimen surface and the black-body cavity. The ratio of the two readings gives the specimen emittance directly, for the temperature of the black body. The detector output is recorded on a fast Brown self-balancing potentiometer. The furnace is provided with a water-cooled blackened shutter which may be inserted behind the specimen to eliminate any transmitted black-body radiation if the specimen is transparent. This apparatus is capable of measuring total normal emittance over the temperature range of 1,000 degrees to 2,000 F. Preliminary data for boron nitride specimens of two thicknesses are shown where total normal emittance is plotted against temperature for two experimental conditions: (1) black-body radiation incident on the back of the specimen and (2) no black-body radiation

  16. 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.

  17. Chemical Hygiene Plan for Onsite Measurement and Sample Shipping Facility Activities

    International Nuclear Information System (INIS)

    Price, W.H.

    1998-01-01

    This chemical hygiene plan presents the requirements established to ensure the protection of employee health while performing work in mobile laboratories, the sample shipping facility, and at the onsite radiological counting facility. This document presents the measures to be taken to promote safe work practices and to minimize worker exposure to hazardous chemicals. Specific hazardous chemicals present in the mobile laboratories, the sample shipping facility, and in the radiological counting facility are presented in Appendices A through G

  18. Size distribution measurements and chemical analysis of aerosol components

    Energy Technology Data Exchange (ETDEWEB)

    Pakkanen, T.A.

    1995-12-31

    The principal aims of this work were to improve the existing methods for size distribution measurements and to draw conclusions about atmospheric and in-stack aerosol chemistry and physics by utilizing size distributions of various aerosol components measured. A sample dissolution with dilute nitric acid in an ultrasonic bath and subsequent graphite furnace atomic absorption spectrometric analysis was found to result in low blank values and good recoveries for several elements in atmospheric fine particle size fractions below 2 {mu}m of equivalent aerodynamic particle diameter (EAD). Furthermore, it turned out that a substantial amount of analyses associated with insoluble material could be recovered since suspensions were formed. The size distribution measurements of in-stack combustion aerosols indicated two modal size distributions for most components measured. The existence of the fine particle mode suggests that a substantial fraction of such elements with two modal size distributions may vaporize and nucleate during the combustion process. In southern Norway, size distributions of atmospheric aerosol components usually exhibited one or two fine particle modes and one or two coarse particle modes. Atmospheric relative humidity values higher than 80% resulted in significant increase of the mass median diameters of the droplet mode. Important local and/or regional sources of As, Br, I, K, Mn, Pb, Sb, Si and Zn were found to exist in southern Norway. The existence of these sources was reflected in the corresponding size distributions determined, and was utilized in the development of a source identification method based on size distribution data. On the Finnish south coast, atmospheric coarse particle nitrate was found to be formed mostly through an atmospheric reaction of nitric acid with existing coarse particle sea salt but reactions and/or adsorption of nitric acid with soil derived particles also occurred. Chloride was depleted when acidic species reacted

  19. Insights from Synthetic Star-forming Regions. II. Verifying Dust Surface Density, Dust Temperature, and Gas Mass Measurements with Modified Blackbody Fitting

    Science.gov (United States)

    Koepferl, Christine M.; Robitaille, Thomas P.; Dale, James E.

    2017-11-01

    We use a large data set of realistic synthetic observations (produced in Paper I of this series) to assess how observational techniques affect the measurement physical properties of star-forming regions. In this part of the series (Paper II), we explore the reliability of the measured total gas mass, dust surface density and dust temperature maps derived from modified blackbody fitting of synthetic Herschel observations. We find from our pixel-by-pixel analysis of the measured dust surface density and dust temperature a worrisome error spread especially close to star formation sites and low-density regions, where for those “contaminated” pixels the surface densities can be under/overestimated by up to three orders of magnitude. In light of this, we recommend to treat the pixel-based results from this technique with caution in regions with active star formation. In regions of high background typical in the inner Galactic plane, we are not able to recover reliable surface density maps of individual synthetic regions, since low-mass regions are lost in the far-infrared background. When measuring the total gas mass of regions in moderate background, we find that modified blackbody fitting works well (absolute error: + 9%; -13%) up to 10 kpc distance (errors increase with distance). Commonly, the initial images are convolved to the largest common beam-size, which smears contaminated pixels over large areas. The resulting information loss makes this commonly used technique less verifiable as now χ 2 values cannot be used as a quality indicator of a fitted pixel. Our control measurements of the total gas mass (without the step of convolution to the largest common beam size) produce similar results (absolute error: +20%; -7%) while having much lower median errors especially for the high-mass stellar feedback phase. In upcoming papers (Paper III; Paper IV) of this series we test the reliability of measured star formation rate with direct and indirect techniques.

  20. Comparing range data across the slow-time dimension to correct motion measurement errors beyond the range resolution of a synthetic aperture radar

    Science.gov (United States)

    Doerry, Armin W.; Heard, Freddie E.; Cordaro, J. Thomas

    2010-08-17

    Motion measurement errors that extend beyond the range resolution of a synthetic aperture radar (SAR) can be corrected by effectively decreasing the range resolution of the SAR in order to permit measurement of the error. Range profiles can be compared across the slow-time dimension of the input data in order to estimate the error. Once the error has been determined, appropriate frequency and phase correction can be applied to the uncompressed input data, after which range and azimuth compression can be performed to produce a desired SAR image.

  1. In Situ Measurement of the Infrared Spectral Extinction for Various Chemical, Biological, and Background Aerosols

    National Research Council Canada - National Science Library

    Gurton, Kristan

    2003-01-01

    We conducted a series spectral extinction measurements on a variety of aerosolized chemical and biological simulants over the spectral range 3-13 microns using conventional Fourier transform infrared (FTIR...

  2. 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

  3. Electron Scale Turbulence and Transport in an NSTX H-mode Plasma Using a Synthetic Diagnostic for High-k Scattering Measurements

    Science.gov (United States)

    Ruiz Ruiz, Juan; Guttenfelder, Walter; Loureiro, Nuno; Ren, Yang; White, Anne; MIT/PPPL Collaboration

    2017-10-01

    Turbulent fluctuations on the electron gyro-radius length scale are thought to cause anomalous transport of electron energy in spherical tokamaks such as NSTX and MAST in some parametric regimes. In NSTX, electron-scale turbulence is studied through a combination of experimental measurements from a high-k scattering system and gyrokinetic simulations. Until now most comparisons between experiment and simulation of electron scale turbulence have been qualitative, with recent work expanding to more quantitative comparisons via synthetic diagnostic development. In this new work, we propose two alternate, complementary ways to perform a synthetic diagnostic using the gyrokinetic code GYRO. The first approach builds on previous work and is based on the traditional selection of wavenumbers using a wavenumber filter, for which a new wavenumber mapping was implemented for general axisymmetric geometry. A second alternate approach selects wavenumbers in real-space to compute the power spectra. These approaches are complementary, and recent results from both synthetic diagnostic approaches applied to NSTX plasmas will be presented. Work supported by U.S. DOE contracts DE-AC02-09CH11466 and DE-AC02-05CH11231.

  4. Chemical composition measurements of the low activity waste (LAW) EPA-Series glasses

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-01

    In this report, the Savannah River National Laboratory provides chemical analysis results for a series of simulated low activity waste glasses provided by Pacific Northwest National Laboratory as part of an ongoing development task. The measured chemical composition data are reported and compared with the targeted values for each component for each glass. A detailed review showed no indications of errors in the preparation or measurement of the study glasses. All of the measured sums of oxides for the study glasses fell within the interval of 100.2 to 100.8 wt %, indicating recovery of all components. Comparisons of the targeted and measured chemical compositions showed that the measured values for the glasses met the targeted concentrations within 10% for those components present at more than 5 wt %.

  5. Synthetic Plant Defense Elicitors

    Directory of Open Access Journals (Sweden)

    Yasemin eBektas

    2015-01-01

    Full Text Available To defend themselves against invading pathogens plants utilize a complex regulatory network that coordinates extensive transcriptional and metabolic reprogramming. Although many of the key players of this immunity-associated network are known, the details of its topology and dynamics are still poorly understood. As an alternative to forward and reverse genetic studies, chemical genetics-related approaches based on bioactive small molecules have gained substantial popularity in the analysis of biological pathways and networks. Use of such molecular probes can allow researchers to access biological space that was previously inaccessible to genetic analyses due to gene redundancy or lethality of mutations. Synthetic elicitors are small drug like molecules that induce plant defense responses, but are distinct from known natural elicitors of plant immunity. While the discovery of the some synthetic elicitors had already been reported in the 1970s, recent breakthroughs in combinatorial chemical synthesis now allow for inexpensive high-throughput screens for bioactive plant defense-inducing compounds. Along with powerful reverse genetics tools and resources available for model plants and crop systems, comprehensive collections of new synthetic elicitors will likely allow plant scientists to study the intricacies of plant defense signaling pathways and networks in an unparalleled fashion. As synthetic elicitors can protect crops from diseases, without the need to be directly toxic for pathogenic organisms, they may also serve as promising alternatives to conventional biocidal pesticides, which often are harmful for the environment, farmers and consumers. Here we are discussing various types of synthetic elicitors that have been used for studies on the plant immune system, their modes-of-action as well as their application in crop protection.

  6. Fluorescence spectroscopy of synthetic melanin in solution

    Energy Technology Data Exchange (ETDEWEB)

    Perna, G.; Frassanito, M.C. [Dipartimento di Scienze Biomediche, Universita di Foggia, Viale Pinto, 71100 Foggia (Italy); Palazzo, G. [Dipartimento di Chimica, Universita di Bari, Via Orabona 4, 70126 Bari (Italy); Gallone, A. [Dipartimento di Scienze Biomediche, Universita di Foggia, Viale Pinto, 71100 Foggia (Italy); Mallardi, A. [ICPS-CNR, Via Orabona 4, 70126 Bari (Italy); Biagi, P.F. [Dipartimento Interateneo di Fisica, Universita di Bari, Via Amendola 173, 70126 Bari (Italy); Capozzi, V. [Dipartimento di Scienze Biomediche, Universita di Foggia, Viale Pinto, 71100 Foggia (Italy)], E-mail: v.capozzi@unifg.it

    2009-01-15

    We report a detailed investigation of fluorescence properties of synthetic eumelanin pigment in solution. A complete set of fluorescence spectra in the near-UV and visible range is analysed. Excitation spectra at a few selected emission energies are also investigated. Our measurements support the hypothesis that fluorescence in eumelanin is related to chemically distinct oligomeric units that can be selectively excited. Fluorescence due to large oligomer systems is spectrally differentiated from that due to monomers and small oligomer systems. Fluorescence excitation measurements show the contribution of 5,6-dihydroxyndole-2-carboxylic acid and 5,6-dihydroxyndole monomers to the emission of small-size oligomers.

  7. Carpet-dust chemicals as measures of exposure: Implications of variability

    Directory of Open Access Journals (Sweden)

    Whitehead Todd P

    2012-03-01

    Full Text Available Abstract Background There is increasing interest in using chemicals measured in carpet dust as indicators of chemical exposures. However, investigators have rarely sampled dust repeatedly from the same households and therefore little is known about the variability of chemical levels that exist within and between households in dust samples. Results We analyzed 9 polycyclic aromatic hydrocarbons, 6 polychlorinated biphenyls, and nicotine in 68 carpet-dust samples from 21 households in agricultural communities of Fresno County, California collected from 2003-2005. Chemical concentrations (ng per g dust ranged from Conclusions Our findings suggest that attenuation bias should be relatively modest when using these semi-volatile carpet-dust chemicals as exposure surrogates in epidemiologic studies.

  8. Enhanced measurement of residual chemical shift anisotropy for small molecule structure elucidation.

    Science.gov (United States)

    Liu, Yizhou; Cohen, Ryan D; Gustafson, Kirk R; Martin, Gary E; Williamson, R Thomas

    2018-03-05

    A method is introduced to measure residual chemical shift anisotropies conveniently and accurately in the mesophase of poly-γ-(benzyl-l-glutamate). The alignment amplitude is substantially enhanced over common methods which greatly benefits measurements particularly on sp 3 carbons. The approach offers significant improvements in data accuracy and utility for small molecule structure determination.

  9. Measurements of radon and chemical elements: Popocatepetl volcano; Mediciones de radon y elementos quimicos: Volcan Popocatepetl

    Energy Technology Data Exchange (ETDEWEB)

    Pena, P.; Segovia, N.; Lopez, B.; Reyes, A.V. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Armienta, M.A.; Valdes, C.; Mena, M. [IGFUNAM, Ciudad Universitaria, 04510 Mexico D.F. (Mexico); Seidel, J.L.; Monnin, M. [UMR 5569 CNRS Hydrosciences, Montpellier (France)

    2002-07-01

    The Popocatepetl volcano is a higher risk volcano located at 60 Km from Mexico City. Radon measurements on soil in two fixed seasons located in the north slope of volcano were carried out. Moreover the radon content, major chemical elements and tracks in water samples of three springs was studied. The radon of soil was determined with solid detectors of nuclear tracks (DSTN). The radon in subterranean water was evaluated through the liquid scintillation method and it was corroborated with an Alpha Guard equipment. The major chemical elements were determined with conventional chemical methods and the track elements were measured using an Icp-Ms equipment. The radon on soil levels were lower, indicating a moderate diffusion of the gas across the slope of the volcano. The radon in subterranean water shown few changes in relation with the active scene of the volcano. The major chemical elements and tracks showed a stable behavior during the sampling period. (Author)

  10. In vivo ultrasound and biometric measurements predict the empty body chemical composition in Nellore cattle.

    Science.gov (United States)

    Castilhos, A M; Francisco, C L; Branco, R H; Bonilha, S F M; Mercadante, M E Z; Meirelles, P R L; Pariz, C M; Jorge, A M

    2018-03-06

    Evaluation of the body chemical composition of beef cattle can only be measured postmortem and those data cannot be used in real production scenarios to adjust nutritional plans. The objective of this study was to develop multiple linear regression equations from in vivo measurements, such as ultrasound parameters [backfat thickness (uBFT, mm), rump fat thickness (uRF, mm), and ribeye area (uLMA, cm2)], shrunk body weight (SBW, kg), age (AG, d), hip height (HH, m), as well as from postmortem measurements (composition of the 9th to 11th rib section) to predict the empty body and carcass chemical composition for Nellore cattle. Thirty-three young bulls were used (339 ± 36.15 kg and 448 ± 17.78 d for initial weight and age, respectively). Empty body chemical composition (protein, fat, water, and ash in kg) was obtained by combining non-carcass and carcass components. Data were analyzed using the PROC REG procedure of SAS software. Mallows' Cp values were close to the ideal value of number of independent variables in the prediction equations plus one. Equations to predict chemical components of both empty body and carcass using in vivo measurements presented higher R2 values than those determined by postmortem measurements. Chemical composition of the empty body using in vivo measurements was predicted with R2 > 0.73. Equations to predict chemical composition of the carcass from in vivo measurements showed R2 lower (R2Chemical compounds from components of the empty body of Nellore cattle can be calculated by the following equations: Protein (kg) = 47.92 + 0.18 × SBW × 1.46 × uRF - 30.72 × HH (R2 = 0.94, RMSPE = 1.79); Fat (kg) = 11.33 + 0.16 × SBW + 2.09 × uRF - 0.06 × AG (R2 = 0.74, RMSPE = 4.18); Water (kg) = 34.00 + 0.55 × SBW + 0.10 × AG 2.34 × uRF (R2 = 0.96, RMSPE = 5.47). In conclusion, the coefficients of determination (for determining the chemical composition of the empty body) of the equations derived from in vivo measures were higher than those

  11. Small-Chamber Measurements of Chemical-Specific Emission Factors for Drywall

    OpenAIRE

    Maddalena, Randy; Russell, Marion; Apte, Michael G.

    2010-01-01

    Imported drywall installed in U.S. homes is suspected of being a source of odorous and potentially corrosive indoor pollutants. To support an investigation of those building materials by the Consumer Products Safety Commission (CPSC), Lawrence Berkeley National Laboratory (LBNL) measured chemical-specific emission factors for 30 samples of drywall materials. Emission factors are reported for 75 chemicals and 30 different drywall samples encompassing both domestic and imported stock and incorp...

  12. Synthetic biology and metabolic engineering.

    Science.gov (United States)

    Stephanopoulos, Gregory

    2012-11-16

    Metabolic engineering emerged 20 years ago as the discipline occupied with the directed modification of metabolic pathways for the microbial synthesis of various products. As such, it deals with the engineering (design, construction, and optimization) of native as well as non-natural routes of product synthesis, aided in this task by the availability of synthetic DNA, the core enabling technology of synthetic biology. The two fields, however, only partially overlap in their interest in pathway engineering. While fabrication of biobricks, synthetic cells, genetic circuits, and nonlinear cell dynamics, along with pathway engineering, have occupied researchers in the field of synthetic biology, the sum total of these areas does not constitute a coherent definition of synthetic biology with a distinct intellectual foundation and well-defined areas of application. This paper reviews the origins of the two fields and advances two distinct paradigms for each of them: that of unit operations for metabolic engineering and electronic circuits for synthetic biology. In this context, metabolic engineering is about engineering cell factories for the biological manufacturing of chemical and pharmaceutical products, whereas the main focus of synthetic biology is fundamental biological research facilitated by the use of synthetic DNA and genetic circuits.

  13. Effect of Esters on the Permeation of Chemicals with Different Polarities through Synthetic Artificial Membranes Using a High-Throughput Diffusion Cell Array.

    Science.gov (United States)

    Uchida, Takashi; Nishioka, Keisuke; Motoki, Anzu; Yakumaru, Masafumi; Sano, Tomohiko; Todo, Hiroaki; Sugibayashi, Kenji

    2016-01-01

    This study investigated the effects of 25 kinds of esters that are used in cosmetics on the permeation of four model compounds with different polarities (caffeine [CF], aminopyrine [AMP], benzoic acid [BA], and flurbiprofen [FP]). The amount of each model compound that permeated through two types of artificial membrane (silicone and Strat-M ® ) was measured and correlated with the physicochemical properties of the esters, including their solubility, viscosity, wettability, surface tension, and uptake. The amount of each model compound that permeated through the silicone membrane was not significantly correlated with the solubility of the esters but was significantly correlated with all other measured physical properties of the esters. Similar correlations were observed for the amounts of AMP, BA, and FP that passed through the Strat-M ® membrane. However, the amount of CF that permeated through the Strat-M ® membrane also correlated with the solubility of the esters. There was a highly significant correlation between the amount permeating through the silicone and Strat-M ® membranes because the model compounds had high lipophilicity. These findings demonstrated that to control the permeation of various chemicals through artificial membranes, it is important to consider the uptake of the esters and that the solubility of the esters is also an important consideration when using a more complex membrane.

  14. Quantification of in vitro wear of a synthetic meniscus implant using gravimetric and micro-CT measurements.

    Science.gov (United States)

    Elsner, Jonathan J; Shemesh, Maoz; Shefy-Peleg, Adaya; Gabet, Yankel; Zylberberg, Eyal; Linder-Ganz, Eran

    2015-09-01

    A synthetic meniscus implant was recently developed for the treatment of patients with mild to moderate osteoarthritis with knee pain associated with medial joint overload. The implant is distinctively different from most orthopedic implants in its pliable construction, and non-anchored design, which enables implantation through a mini-arthrotomy without disruption to the bone, cartilage, and ligaments. Due to these features, it is important to show that the material and design can withstand knee joint conditions. This study evaluated the long-term performance of this device by simulating loading for a total of 5 million gait cycles (Mc), corresponding to approximately five years of service in-vivo. All five implants remained in good condition and did not dislodge from the joint space during the simulation. Mild abrasion was detected by electron microscopy, but µ-CT scans of the implants confirmed that the damage was confined to the superficial surfaces. The average gravimetric wear rate was 14.5 mg/Mc, whereas volumetric changes in reconstructed µ-CT scans point to an average wear rate of 15.76 mm(3)/Mc (18.8 mg/Mc). Particles isolated from the lubricant had average diameter of 15 µm. The wear performance of this polycarbonate-urethane meniscus implant concept under ISO-14243 loading conditions is encouraging. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. 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.

  16. Comparison of sodium content of workplace and homemade meals through chemical analysis and salinity measurements.

    Science.gov (United States)

    Shin, Eun-Kyung; Lee, Yeon-Kyung

    2014-10-01

    Most Koreans consume nearly 70-80% of the total sodium through their dishes. The use of a salinometer to measure salinity is recommended to help individuals control their sodium intake. The purpose of this study was to compare sodium content through chemical analysis and salinity measurement in foods served by industry foodservice operations and homemade meals. Workplace and homemade meals consumed by employees in 15 cafeterias located in 8 districts in Daegu were collected and the sodium content was measured through chemical analysis and salinity measurements and then compared. The foods were categorized into 9 types of menus with 103 workplace meals and 337 homemade meals. Workplace meals did not differ significantly in terms of sodium content per 100 g of food but had higher sodium content via chemical analysis in roasted foods per portion. Homemade meals had higher broth salt content and higher salt content by chemical analysis per 100 g of roasted foods and hard-boiled foods. One-dish workplace meals had higher salinity (P content (P content per 100 g of foods was higher in one-dish workplace meals (P content in foods and control one's sodium intake within the daily intake target as a way to promote cooking bland foods at home. However, estimated and actual measured values may differ.

  17. Surface deformation measured with interferometric synthetic aperture radar: Case studies of basin and range and Garlock-San Andreas fault

    Science.gov (United States)

    Greene, Fernando

    Interferometric Synthetic Aperture Radar (InSAR) and Global Positioning System (GPS) is widely used to detect ground deformation from varieties of geophysical origins. However, most studies lack the spatial and temporal resolutions to better characterize such observations. The purpose of this research is to use multi-track satellite radar imagery to generate time series to study and monitor vertical ground deformation over large regions such as the Nevada portion of the Basin and Range Province and the western end of the Mojave Desert. We developed an innovative method to remove horizontal movements from InSAR line-of-sight (LOS) observations using a GPS velocity field and subsequently combine the multi-track imagery resulting in one single high spatial resolution map of observed vertical crustal and surface movements. By implementing this technique we detect vertical deformation signals with short and intermediate wavelength signals associated to tectonic processes such as interseismic and postseismic deformation. In Central Nevada Seismic Belt we detect in three independent orbits a broad area of uplift that confirms results of previous studies that associate the origin of this signal to post-seimic deformation of the historic earthquakes at this region. In south-central Nevada we detect several valleys that show a gradual eastward tilt of the valley floors due to deep geodynamical processes. The valleys located at the eastern side of Ruby Mountains show a range decrease that could indicate uplift related to magma intrusion or post-seismic deformation due to older, unrecognized earthquakes. In the Big Bend segment in southern California we detect vertical uplift as expected by mechanical models of interseismic deformation. Additionaly all our velocity maps reveal small wavelength deformation signals of anthropogenic origin.

  18. Effects of ultrasonic and thermo-chemical pre-treatments on methane production from fat, oil and grease (FOG) and synthetic kitchen waste (KW) in anaerobic co-digestion.

    Science.gov (United States)

    Li, Chenxi; Champagne, Pascale; Anderson, Bruce C

    2013-02-01

    The effects of ultrasonic and thermo-chemical pre-treatments on the methane production potential of anaerobic co-digestion with synthetic kitchen waste (KW) or fat, oil and grease (FOG) were investigated. Non-linear regressions were fitted to accurately assess and compare the methane production from co-digestion under the various pre-treatment conditions and to achieve representative simulations and predictions. Ultrasonic pre-treatment was not found to improve methane production effectively from either FOG co-digestion or KW co-digestions. Thermo-chemical pre-treatment could increase methane production yields from both FOG and KW co-digestions. COD solubilization was found to effectively represent the effects of pre-treatment. A comprehensive evaluation indicated that the thermo-chemical pre-treatments of pH=10, 55°C and pH=8, 55°C provided the best conditions to increase methane production from FOG and KW co-digestions, respectively. The most effective enhancement of biogas production (288±0.85mLCH(4)/g TVS) was achieved from thermo-chemically pre-treated FOG co-digestion, which was 9.9±1.5% higher than FOG co-digestion without thermo-chemical pre-treatment. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Confocal detection of Rayleigh scattering for residual stress measurement in chemically tempered glass

    Energy Technology Data Exchange (ETDEWEB)

    Hödemann, S., E-mail: siim.hodemann@ut.ee; Möls, P.; Kiisk, V.; Saar, R.; Kikas, J. [Institute of Physics, University of Tartu, Wilhelm Ostwald st., Tartu 50411 (Estonia); Murata, T. [Nippon Electric Glass Co., 7-1 Seiran 2-chome, Otsu-shi, Shiga 520-8639 (Japan)

    2015-12-28

    A new optical method is presented for evaluation of the stress profile in chemically tempered (chemically strengthened) glass based on confocal detection of scattered laser beam. Theoretically, a lateral resolution of 0.2 μm and a depth resolution of 0.6 μm could be achieved by using a confocal microscope with high-NA immersion objective. The stress profile in the 250 μm thick surface layer of chemically tempered lithium aluminosilicate glass was measured with a high spatial resolution to illustrate the capability of the method. The confocal method is validated using transmission photoelastic and Na{sup +} ion concentration profile measurement. Compositional influence on the stress-optic coefficient is calculated and discussed. Our method opens up new possibilities for three-dimensional scattered light tomography of mechanical imaging in birefringent materials.

  20. 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.

  1. 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.

  2. Note: X-ray radiography for measuring chemical diffusion in metallic melts

    Energy Technology Data Exchange (ETDEWEB)

    Griesche, A.; Zhang, B. [Institut fuer Materialphysik im Weltraum, Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), Linder Hoehe, 51170 Koeln (Germany); Solorzano, E.; Garcia-Moreno, F. [Institute of Applied Materials, Helmholtz-Zentrum Berlin (HZB), Hahn-Meitner Platz 1, 14109 Berlin (Germany)

    2010-05-15

    A x-ray radioscopy technique for measuring in situ chemical diffusion coefficients in metallic melts is presented. The long-capillary diffusion measurement method is combined with imaging techniques using microfocus tubes and flat panel detectors in order to visualize and quantitatively analyze diffusive mixing of two melts of different chemical composition. The interdiffusion coefficient as function of temperature and time is obtained by applying Fick's diffusion laws. Tracking the time dependence of the mean square penetration depth of the mixing process allows to detect changes in the mass transport caused by convective flow. The possibility to sort out convective mass transport contributions from analysis enhances significantly the accuracy compared to the conventional long-capillary diffusion measurement method with postmortem analysis. The performance of this novel diffusion measurement method with x-ray radiography technique is demonstrated by a diffusion experiment in an Al-Ni melt.

  3. Measurement of small-signal gain on COIL with chemically generated molecular iodine

    Czech Academy of Sciences Publication Activity Database

    Jirásek, Vít; Špalek, Otomar; Čenský, Miroslav; Kodymová, Jarmila

    2010-01-01

    Roč. 46, č. 9 (2010), s. 1350-1353 ISSN 0018-9197 Institutional research plan: CEZ:AV0Z10100523 Keywords : chemical laser s * iodine * gain measurement Subject RIV: BH - Optics, Masers, Laser s Impact factor: 2.477, year: 2010

  4. Synthetic Biology and Personalized Medicine

    Science.gov (United States)

    Jain, K.K.

    2013-01-01

    Synthetic biology, application of synthetic chemistry to biology, is a broad term that covers the engineering of biological systems with structures and functions not found in nature to process information, manipulate chemicals, produce energy, maintain cell environment and enhance human health. Synthetic biology devices contribute not only to improve our understanding of disease mechanisms, but also provide novel diagnostic tools. Methods based on synthetic biology enable the design of novel strategies for the treatment of cancer, immune diseases metabolic disorders and infectious diseases as well as the production of cheap drugs. The potential of synthetic genome, using an expanded genetic code that is designed for specific drug synthesis as well as delivery and activation of the drug in vivo by a pathological signal, was already pointed out during a lecture delivered at Kuwait University in 2005. Of two approaches to synthetic biology, top-down and bottom-up, the latter is more relevant to the development of personalized medicines as it provides more flexibility in constructing a partially synthetic cell from basic building blocks for a desired task. PMID:22907209

  5. Chemical composition of wildland and agricultural biomass burning particles measured downwind during the BBOP study

    Science.gov (United States)

    Onasch, T. B.; Shilling, J. E.; Wormhoudt, J.; Sedlacek, A. J., III; Fortner, E.; Pekour, M. S.; Chand, D.; Zhou, S.; Collier, S.; Zhang, Q.; Kleinman, L. I.; Lewis, E. R.; Yokelson, R. J.; Adachi, K.; Buseck, P. R.; Freedman, A.; Williams, L. R.

    2017-12-01

    The Biomass Burning Observation Project (BBOP), a Department of Energy (DOE) sponsored study, measured emissions from wildland fires in the Pacific Northwest and agricultural burns in the Central Southeastern US from the DOE Gulfstream-1 airborne platform over a four month period in 2013. Rapid physical, chemical and optical changes in biomass burning particles were measured downwind (tar balls and SP-AMS OA quantification while operating with both laser and tungsten vaporizers.

  6. Development of a biofluid chemical measurement system using liquid core optical fiber Raman spectroscopy

    Science.gov (United States)

    Qi, Dahu

    Near Infrared (NIR) Raman spectroscopy can provide compositional information about chemicals dissolved in biological fluids. The Raman intensity is proportional to the amount of chemicals. It has been developed for years as a tool to measure biofluid chemical concentrations by illuminating sample and collecting Raman intensity holding the sample in a cuvette geometry. It has been found that the Raman intensity can be enhanced by increasing the excitation and collection sample volume in a liquid core optical fiber (LCOF) geometry. In this thesis, we present a biofluid chemical concentration measurement system using LCOF Raman spectroscopy. A home-built LCOF Raman spectroscopy system designed for this purpose using 830 nm illumination is described in the thesis. The system is switchable between LCOF and traditional cuvette geometry. The system was characterized using aqueous solutions. The Raman intensities of aqueous solutions from the two geometries were compared in both theory and experiment. The results agreed well with each other. As high as 15 fold Raman enhancement was observed. The Raman spectra of biological chemicals in aqueous solution and spiked urine samples were acquired from LCOF and cuvette geometries. The concentrations were predicted using partial least squares (PLS) leave one out cross validation. The results from the two geometries were compared. Concentrations of creatinine were measured in both setups. The LCOF geometry had an advantage at shorter integration times because of Raman enhancement while the cuvette geometry gave better results at longer integration times due to a better system reproducibility. The LCOF Raman intensity varies from sample to sample with sample absorption coefficient as well as the chemical concentration. This effect can add uncertainty to the concentration measurement. Biofluid samples from multiple patients vary a lot in absorption coefficient, which could cause as much as 20% uncertainty in concentration measurement

  7. When synthetic chemicals degrade in the environment: What are the absolute fate, effects, and potential risks to humans and the ecosystem?

    Science.gov (United States)

    Boxall, Alistair; Sinclair, C.; Fenner, Kathrin; Kolpin, Dana W.; Maund, S.

    2004-01-01

    Various processes degrade synthetic chemicals—pesticides, pharmaceuticals, biocides, and industrials—in the environment (1, 2). Consequently, the environment may be exposed to a mixture of the parent compounds and any resulting degradation products (degradates). Recent advances in analytical methodology and greater access to analytical standards have advanced degradates research (3, 4). Specifically, research on pesticides has found degradates in surface water (5–10), groundwater (11–13), precipitation (14–16), air (17, 18), and sediment (19, 20). Pharmaceuticals and detergent degradates also exist in the environment (21–23). Figure 1 shows that degradates were detected as often as or more frequently than the parent compound.

  8. Protocol for Measuring the Thermal Properties of a Supercooled Synthetic Sand-water-gas-methane Hydrate Sample.

    Science.gov (United States)

    Muraoka, Michihiro; Susuki, Naoko; Yamaguchi, Hiroko; Tsuji, Tomoya; Yamamoto, Yoshitaka

    2016-03-21

    Methane hydrates (MHs) are present in large amounts in the ocean floor and permafrost regions. Methane and hydrogen hydrates are being studied as future energy resources and energy storage media. To develop a method for gas production from natural MH-bearing sediments and hydrate-based technologies, it is imperative to understand the thermal properties of gas hydrates. The thermal properties' measurements of samples comprising sand, water, methane, and MH are difficult because the melting heat of MH may affect the measurements. To solve this problem, we performed thermal properties' measurements at supercooled conditions during MH formation. The measurement protocol, calculation method of the saturation change, and tips for thermal constants' analysis of the sample using transient plane source techniques are described here. The effect of the formation heat of MH on measurement is very small because the gas hydrate formation rate is very slow. This measurement method can be applied to the thermal properties of the gas hydrate-water-guest gas system, which contains hydrogen, CO2, and ozone hydrates, because the characteristic low formation rate of gas hydrate is not unique to MH. The key point of this method is the low rate of phase transition of the target material. Hence, this method may be applied to other materials having low phase-transition rates.

  9. Estimating air chemical emissions from research activities using stack measurement data.

    Science.gov (United States)

    Ballinger, Marcel Y; Duchsherer, Cheryl J; Woodruff, Rodger K; Larson, Timothy V

    2013-03-01

    &D facilities using chemical inventory data. Air emissions from research operations are difficult to estimate because of the changing nature of research processes and the small quantity and wide variety of chemicals used. Analysis of stack measurements taken over multiple facilities and a 10-year period using a Monte Carlo technique provided a method to quantify the low emissions and to estimate release fractions based on chemical inventories. The variation in release fractions did not correlate well with factors investigated, confirming the complexities in estimating R&D emissions.

  10. Measurement of discrete energy-level spectra in individual chemically synthesized gold nanoparticles

    DEFF Research Database (Denmark)

    Kuemmeth, Ferdinand; Bolotin, Kirill I; Shi, Su-Fei

    2008-01-01

    We form single-electron transistors from individual chemically synthesized gold nanoparticles, 5-15 nm in diameter, with monolayers of organic molecules serving as tunnel barriers. These devices allow us to measure the discrete electronic energy levels of individual gold nanoparticles that are......, by virtue of chemical synthesis, well-defined in their composition, size and shape. We show that the nanoparticles are nonmagnetic and have spectra in good accord with random-matrix-theory predictions taking into account strong spin-orbit coupling....

  11. A rail system for circular synthetic aperture sonar imaging and acoustic target strength measurements: design/operation/preliminary results.

    Science.gov (United States)

    Kennedy, J L; Marston, T M; Lee, K; Lopes, J L; Lim, R

    2014-01-01

    A 22 m diameter circular rail, outfitted with a mobile sonar tower trolley, was designed, fabricated, instrumented with underwater acoustic transducers, and assembled on a 1.5 m thick sand layer at the bottom of a large freshwater pool to carry out sonar design and target scattering response studies. The mobile sonar tower translates along the rail via a drive motor controlled by customized LabVIEW software. The rail system is modular and assembly consists of separately deploying eight circular arc sections, measuring a nominal center radius of 11 m and 8.64 m arc length each, and having divers connect them together in the underwater environment. The system enables full scale measurements on targets of interest with 0.1° angular resolution over a complete 360° aperture, without disrupting target setup, and affording a level of control over target environment conditions and noise sources unachievable in standard field measurements. In recent use, the mobile cart carrying an instrumented sonar tower was translated along the rail in 720 equal position increments and acoustic backscatter data were acquired at each position. In addition, this system can accommodate both broadband monostatic and bistatic scattering measurements on targets of interest, allowing capture of target signature phenomena under diverse configurations to address current scientific and technical issues encountered in mine countermeasure and unexploded ordnance applications. In the work discussed here, the circular rail apparatus is used for acoustic backscatter testing, but this system also has the capacity to facilitate the acquisition of magnetic and optical sensor data from targets of interest. A brief description of the system design and operation will be presented along with preliminary processed results for data acquired from acoustic measurements conducted at the Naval Surface Warfare Center, Panama City Division Test Pond Facility. [Work Supported by the U.S. Office of Naval Research and

  12. Three-dimensional laser-induced fluorescence measurements of turbulent chemical plumes

    Science.gov (United States)

    True, Aaron; Crimaldi, John

    2017-11-01

    In order to find prey, mates, and suitable habitat, many organisms must navigate through complex chemical plume structures in turbulent flow environments. In this context, we investigate the spatial and temporal structure of chemical plumes released isokinetically into fractal-grid-generated turbulence in an open channel flow. We first utilized particle image velocimetry (PIV) to characterize flow conditions (mean free stream velocities, turbulence intensities, turbulent kinetic energy dissipation rates, Taylor Reynolds numbers). We then implemented a newly developed high-resolution, high-speed, volumetric scanning laser-induced fluorescence (LIF) system for near time-resolved measurements of three-dimensional chemical plume structures. We investigated cases with and without a cylinder wake, and compare statistical (mean, variance, intermittency, probability density functions) and spectral (power spectrum of concentration fluctuations) characteristics of the chemical plume structure. Stretching and folding of complex three-dimensional filament structures during chaotic turbulent mixing is greatly enhanced in the cylinder wake case. In future experiments, we will implement simultaneous PIV and LIF, enabling computation of the covariance of the velocity and chemical concentration fluctuations and thus estimation of turbulent eddy diffusivities. NSF PHY 1555862.

  13. Measuring binding and speciation of hydrophobic organic chemicals at controlled freely dissolved concentrations and without phase separation

    DEFF Research Database (Denmark)

    Gouliarmou, Varvara; Smith, K E C; de Jonge, Lis Wollesen

    2012-01-01

    The binding and speciation of hydrophobic organic chemicals (HOCs) in aqueous solutions were determined by controlling chemical activity and measuring total concentrations. Passive dosing was applied to control chemical activities of HOCs in aqueous solutions by equilibrium partitioning from a poly...

  14. Effect of dimethylamine on the gas phase sulfuric acid concentration measured by Chemical Ionization Mass Spectrometry

    CERN Document Server

    Rondo, L.; Kürten, A.; Adamov, A.; Bianchi, F.; Breitenlechner, M.; Duplissy, J.; Franchin, A.; Dommen, J.; Donahue, N. M.; Dunne, E. M.; Flagan, R. C.; Hakala, J.; Hansel, A.; Keskinen, H.; Kim, J.; Jokinen, T.; Lehtipalo, K.; Leiminger, M.; Praplan, A.; Riccobono, F.; Rissanen, M. P.; Sarnela, N.; Schobesberger, S.; Simon, M.; Sipilä, M.; Smith, J. N.; Tomé, A.; Tröstl, J.; Tsagkogeorgas, G.; Vaattovaara, P.; Winkler, P. M.; Williamson, C.; Wimmer, D.; Baltensperger, U.; Kirkby, J.; Kulmala, M.; Petäjä, T.; Worsnop, D. R.; Curtius, J.

    2016-01-01

    Sulfuric acid is widely recognized as a very important substance driving atmospheric aerosolnucleation. Based on quantum chemical calculations it has been suggested that the quantitative detectionof gas phase sulfuric acid (H2SO4) by use of Chemical Ionization Mass Spectrometry (CIMS) could be biased inthe presence of gas phase amines such as dimethylamine (DMA). An experiment (CLOUD7 campaign) was setup at the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber to investigate the quantitative detection ofH2SO4in the presence of dimethylamine by CIMS at atmospherically relevant concentrations. For the first time inthe CLOUD experiment, the monomer sulfuric acid concentration was measured by a CIMS and by two CI-APi-TOF(Chemical Ionization-Atmospheric Pressure interface-Time Of Flight) mass spectrometers. In addition, neutralsulfuric acid clusters were measured with the CI-APi-TOFs. The CLOUD7 measurements show that in the presenceof dimethylamine (<5 to 70 pptv) the sulfuric acid monomer measured by the CIMS...

  15. Bromide as chemical tracer to measure the liquid effluent flow at IPEN-CNEN/SP

    International Nuclear Information System (INIS)

    Silva, Douglas B.; Faustino, Mainara G.; Monteiro, Lucilena R.; Cotrim, Marycel E.B.; Pires, Maria Aparecida F.

    2013-01-01

    Due to recent changes in CONAMA Resolution 357, which occurred through the publication of Resolution 430, on May 13, 2011 that now set standards about the effluent release, IPEN-CNEN/SP initiated several actions to improve the Environmental Monitoring Program (PMA-Q) of stable chemical compounds. Besides various parameters (physical and chemical) established by CONAMA, the submission of an annual pollution inventory report became necessary. The liquid effluent flow measurement is required to implement this inventory. Thereby, this paper describes a study that uses bromide as a chemical tracer. This paper presents the results of 6 tracer releases in IPEN wastewater collection network between 2011 and 2012. Two tracer releases designs were performed: single pulse and continuous releases performed with 1 to 6 hours duration, done by using one single piston pump manufactured by DIONEX. After the release, one fraction of the effluent was collected every 15 minutes at IPEN effluent monitoring station. The tracer concentration in the effluent was analyzed by ion chromatography and flow was calculated considering the dilution in the system and pump flow set up for the release. The flow values were measured in 6 events were determined and evaluated as per Brazilian regulation requirements. Experimental designs to be implemented during 2013 monitoring were also discussed in this paper, contributing to legal compliance and to improve IPEN's Environmental Monitoring Program for stable chemical compounds (PMA-Q). (author)

  16. Iodine flow rate measurement for COIL with the chemical iodine generator based on absorption spectroscopy

    Science.gov (United States)

    Zhao, Weili; Zhang, Yuelong; Zhang, Peng; Xu, Mingxiu; Jin, Yuqi; Sang, Fengting

    2015-02-01

    A dual-components absorption method based on absorption spectroscopy was described in the paper. It can easily eliminate the influence of the serious contamination and aerosol scattering on IFR measurement by utilizing the absorptions of iodine vapor and chlorine on two different wavelengths respectively. According to the character that there is no other gaseous product in the reaction besides iodine vapor, IFR in real time can be obtained by the connections of the pressure and the flow rate among chlorine remainder, iodine vapor, and the buffer gas. We used this method to measure IFR for the first time at the exit of a chemical iodine generator. The average of IFR is coincident with that calculated by chemical weighting mass.

  17. Quantitative determination of methanol and ethanol with synthetic calibration spectra in passive Fourier transform infrared remote sensing measurements.

    Science.gov (United States)

    Guo, Qiaohan; Small, Gary W

    2013-08-01

    A spectral synthesis strategy is introduced to help obtain estimates of path-integrated concentrations in passive Fourier transform infrared (FT-IR) remote sensing measurements conducted during field-monitoring experiments. Obtaining quantitative information from passive infrared data is challenging because of the joint effects of temperature and concentration on spectral intensities. The collection of calibration data for use in modeling spectral intensities for a given set of experimental conditions is also costly and labor intensive. In the work presented here, a radiance model is defined for use in synthesizing calibration spectra that serve as inputs to partial least-squares (PLS) models that relate spectral intensities to path-integrated concentrations. The field data for which quantitative estimates are desired are used to estimate the background temperature associated with a given time and set of experimental conditions. Sample temperatures can be obtained through either experimental measurement or by estimating one calibration release. Given these temperatures, calibration data can be synthesized and the PLS model developed. This methodology is tested with stack monitoring data obtained from controlled releases of pure and mixture samples of heated ethanol and methanol. Experiments were conducted across 6 days with stack temperatures of 150 to 200 °C and with path-integrated concentrations in the range of 10 to 300 parts per million meters. Median relative errors in the estimates of path-integrated concentration were typically in the range of 20% or less, with the best results observed at the higher stack temperatures.

  18. Rate and Temperature Dependence of Adhesion Measured by a Jkr Method on Synthetically Modified Acrylic Pressure Sensitive Adhesives

    Science.gov (United States)

    Garif, Yev; Gerberich, William; Macosko, Christopher; Pocius, Alphonsus

    2003-03-01

    The goal of this study is to model mechanisms of interfacial separation in soft polymers based on experimental results obtained from normal mechanical contacts (JKR test). For the JKR test, cylindrically shaped samples of acrylic pressure sensitive adhesives (PSAs) were synthesized in capillary tubes in presence of a cross-linking agent in order to obtain an elastic PSA-like network (PSA-LN). Surface characteristics of individual samples were altered by co-polymerizing small amounts of polar side-groups such as acrylic acid (AA), dimethylaminoethylacrylate (DMAEA), and acrylonitrile (AN). The measurement was conducted in a ventilated chamber at three different temperatures (0, 25, and 50 degrees Celcius) and zero humidity with a sub-micron-per-second range of contact rates. Within this range, measured adhesion exhibits a transition from nearly rate-independent behavior to power law behavior at higher rates. Power law index matches that from the peel test data of similarly synthesized adhesive tapes. Accordingly, the transition is linked to the characteristic length scale of the process zone at the interface, as opposed to the bulk, ahead of the slowly advancing crack tip.

  19. Subclinical Synovitis Measured by Ultrasound in Rheumatoid Arthritis Patients With Clinical Remission Induced by Synthetic and Biological Modifying Disease Drugs.

    Science.gov (United States)

    Cruces, Marcos; Al Snih, Soham; Serra-Bonett, Natalí; Rivas, Juan C

    2017-10-09

    Rheumatoid arthritis (RA) patients with disease in clinical remission might show subclinical synovitis, which can be related to the progress of structural joint damage. To determine and compare the degree of synovial inflammation by ultrasound (US) in patients with RA in clinical remission, treated with DMARD or combination therapy with DMARD and anti-TNF. Hospital-based cross-sectional study of 58 patients with RA in sustained remission for at least 6 months by DAS28 <2.6, who attended the Rheumatology Service at the Hospital Universitario de Caracas. Patients underwent clinical, functional, and laboratory assessments. Ultrasound was performed in hands measuring synovial effusion, synovial hypertrophy and power Doppler signal; using a semiquantitative 4-point scale of 0=none to 3=severe. Chi-square and t-test were used to compare the clinical, functional, laboratory and US assessments between the DMARD (N=37) and combination therapy with DMARD and anti-TNF (N=21) groups. A p-value <0.05 was considered statistically significant. Out of 58 patients, 25.9% had remission by US and 74.1% had synovial effusion or hypertrophy or positive power Doppler signal. Non-significant differences in US synovitis between the two groups were found. Persistent US activity was evident in a high percentage of rheumatoid arthritis patients in clinical remission by DAS28. No differences in subclinical synovitis measured by US were found between patients with DMARD and anti-TNF-induced clinical remission. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

  20. First satellite measurements of chemical changes in coincidence with sprite activity

    Science.gov (United States)

    Arnone, Enrico; São Sabbas, Fernanda; Kero, Antti; Soula, Serge; Carlotti, Massimo; Chanrion, Olivier; Dinelli, Bianca Maria; Papandrea, Enzo; Castelli, Elisa; Neubert, Torsten

    2010-05-01

    The last twenty years have seen the discovery of electric discharges in the Earth's atmosphere above thunderstorms, the so-called sprites and jets. It has been suggested that they impact the atmospheric chemistry and possibly affect the ozone layer through their repeated occurrence. Whereas theoretical studies and laboratory experiments suggest enhancement of such gasses as nitrogen oxides by up to hundreds of percent within sprites, a definitive detection of their chemical effects have to date been unsuccessful. In this paper, we report on the first measurements of atmospheric chemical perturbations recorded in coincidence with sprite activity. A striking event occurred on 25 August 2003 when the MIPAS spectrometer onboard the Envisat satellite recorded spectroscopic measurements soon after a sequence of 11 sprites observed above Corsica (France) by Eurosprite ground facilities (details of the convective system are discussed in a companion paper by São Sabbas et al.). The measurements show an enhancement of ambient nitrous oxide by 80% at 52 km altitude in the region above the parent thunderstorm. The recorded chemical changes imply sprites can exert significant modification of the atmospheric chemistry at a regional scale, confirming model and laboratory predictions of sprite-chemistry, and requiring a new estimate of their global impact. The results of the analysis and their implications are discussed.

  1. Effect of dimethylamine on the gas phase sulfuric acid concentration measured by Chemical Ionization Mass Spectrometry

    Science.gov (United States)

    Rondo, L.; Ehrhart, S.; Kürten, A.; Adamov, A.; Bianchi, F.; Breitenlechner, M.; Duplissy, J.; Franchin, A.; Dommen, J.; Donahue, N. M.; Dunne, E. M.; Flagan, R. C.; Hakala, J.; Hansel, A.; Keskinen, H.; Kim, J.; Jokinen, T.; Lehtipalo, K.; Leiminger, M.; Praplan, A.; Riccobono, F.; Rissanen, M. P.; Sarnela, N.; Schobesberger, S.; Simon, M.; Sipilä, M.; Smith, J. N.; Tomé, A.; Tröstl, J.; Tsagkogeorgas, G.; Vaattovaara, P.; Winkler, P. M.; Williamson, C.; Wimmer, D.; Baltensperger, U.; Kirkby, J.; Kulmala, M.; Petäjä, T.; Worsnop, D. R.; Curtius, J.

    2016-03-01

    Sulfuric acid is widely recognized as a very important substance driving atmospheric aerosol nucleation. Based on quantum chemical calculations it has been suggested that the quantitative detection of gas phase sulfuric acid (H2SO4) by use of Chemical Ionization Mass Spectrometry (CIMS) could be biased in the presence of gas phase amines such as dimethylamine (DMA). An experiment (CLOUD7 campaign) was set up at the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber to investigate the quantitative detection of H2SO4 in the presence of dimethylamine by CIMS at atmospherically relevant concentrations. For the first time in the CLOUD experiment, the monomer sulfuric acid concentration was measured by a CIMS and by two CI-APi-TOF (Chemical Ionization-Atmospheric Pressure interface-Time Of Flight) mass spectrometers. In addition, neutral sulfuric acid clusters were measured with the CI-APi-TOFs. The CLOUD7 measurements show that in the presence of dimethylamine (growth. Although it was found that the addition of dimethylamine dramatically changes the H2SO4 cluster distribution compared to binary (H2SO4-H2O) conditions, the CIMS detection efficiency does not seem to depend substantially on whether an individual H2SO4 monomer is clustered with a DMA molecule. The experimental observations are supported by numerical simulations based on A Self-contained Atmospheric chemistry coDe coupled with a molecular process model (Sulfuric Acid Water NUCleation) operated in the kinetic limit.

  2. Integrated automation for continuous high-throughput synthetic chromosome assembly and transformation to identify improved yeast strains for industrial production of biofuels and bio-based chemicals

    Science.gov (United States)

    An exponential increase in our understanding of genomes, proteomes, and metabolomes provides greater impetus to address critical biotechnological issues such as sustainable production of biofuels and bio-based chemicals and, in particular, the development of improved microbial biocatalysts for use i...

  3. Paterno`-Bu¨chi Reaction as a Demonstration of Chemical Kinetics and Synthetic Photochemistry Using a Light Emitting Diode Apparatus

    Science.gov (United States)

    Thompson, Matthew P.; Agger, Jonathan; Wong, Lu Shin

    2015-01-01

    The Paterno`-Bu¨chi photocycloaddition reaction is used as the basis for physical-organic final-year undergraduate laboratory experiments designed to emphasize the multidisciplinary approach to modern-day chemical practice. These reactions are performed using commercially available LED-based light sources, which offer a convenient and safe tool…

  4. Synthetic methodologies for carbon nanomaterials.

    Science.gov (United States)

    Liu, Zhaoping; Zhou, Xufeng; Qian, Yitai

    2010-05-04

    Carbon nanomaterials have advanced rapidly over the last two decades and are among the most promising materials that have already changed and will keep on changing human life. Development of synthetic methodologies for these materials, therefore, has been one of the most important subjects of carbon nanoscience and nanotechnology, and forms the basis for investigating the physicochemical properties and applications of carbon nanomaterials. In this Research News article, several synthetic strategies, including solvothermal reduction, solvothermal pyrolysis, hydrothermal carbonization, and soft-chemical exfoliation are specifically discussed and highlighted, which have been developed for the synthesis of novel carbon nanomaterials over the last decade.

  5. Chemical Processing and Transport in the Stratospheric Vortex and Subvortex from Satellite Measurements and Modeling

    Science.gov (United States)

    Santee, Michelle; Manney, Gloria; MacKenzie, Ian; Chipperfield, Martyn; Feng, Wuhu; Sander, Stanley; Froidevaux, Lucien; Livesey, Nathaniel; Bernath, Peter; Walker, Kaley; Boone, Chris

    A suite of atmospheric composition measurements from the Microwave Limb Sounder (MLS) on NASA's Aura satellite and the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) on Canada's SCISAT-1 mission is used to study chemical processing in and dispersal of chemically-processed air from the lower stratospheric polar vortices. In particular, interannual and interhemispheric variability in chlorine activation and deactivation are investigated using measurements of ClO, HCl, and ClONO2. Theoretical understanding is assessed by comparing measurements to customized runs of the SLIMCAT 3D chemical transport model. Results are shown from a newly-updated version of the model that incorporates a sophisticated microphysical scheme as a fully-coupled module, allowing polar stratospheric cloud formation and sedimentation to be calculated interactively in full-chemistry simulations. The impact of recently-published ClOOCl absorption cross sections, which yield a stratospheric ClOOCl photolysis rate substantially lower than previous estimates, on the agreement between modelled and measured chlorine species is evaluated. In addition, measurements of HNO3 and O3 and SLIMCAT results are related to mixing diagnostics to track the springtime export of denitrified, ozone-depleted air from the "subvortex", the transition zone (potential temperatures of 350-450 K) between the region above of strong confinement inside the polar vortex and the region below of less restricted exchange with lower-latitude air. Particularly over Antarctica, such mixing of processed air out of the subvortex may significantly affect the composition of the midlatitude lowermost stratosphere and upper troposphere.

  6. The influence of oscillating electromagnetic fields on membrane structure and function: Synthetic liposome and natural membrane bilayer systems with direct application to the controlled delivery of chemical agents

    Energy Technology Data Exchange (ETDEWEB)

    Liburdy, R.P.; de Manincor, D.; Fingado, B.

    1989-09-01

    Investigations have been conducted to determine if an imposed electromagnetic field can influence membrane transport, and ion and drug permeability in both synthetic and natural cell membrane systems. Microwave fields enhance accumulation of sodium in the lymphocyte and induce protein shedding at Tc. Microwaves also trigger membrane permeability of liposome systems under specific field exposure conditions. Sensitivity varies in a defined way in bilayers displaying a membrane structural phase transition temperature, Tc; maximal release was observed at or near Tc. Significantly, liposome systems without a membrane phase transition were also found to experience permeability increases but, in contrast, this response was temperature independent. The above results indicate that field-enhanced drug release occurs in liposome vesicles that possess a Tc as well as non-Tc liposomes. Additional studies extend non-Tc liposome responses to the in vivo case in which microwaves trigger Gentamicin release from a liposome depot'' placed subcutaneously in the rat hind leg. In addition, evidence is provided that cell surface sequestered liposomes can be triggered by microwave fields to release drugs directly into target cells. 24 refs., 6 figs.

  7. The influence of oscillating electromagnetic fields on membrane structure and function: Synthetic liposome and natural membrane bilayer systems with direct application to the controlled delivery of chemical agents

    International Nuclear Information System (INIS)

    Liburdy, R.P.; de Manincor, D.; Fingado, B.

    1989-09-01

    Investigations have been conducted to determine if an imposed electromagnetic field can influence membrane transport, and ion and drug permeability in both synthetic and natural cell membrane systems. Microwave fields enhance accumulation of sodium in the lymphocyte and induce protein shedding at Tc. Microwaves also trigger membrane permeability of liposome systems under specific field exposure conditions. Sensitivity varies in a defined way in bilayers displaying a membrane structural phase transition temperature, Tc; maximal release was observed at or near Tc. Significantly, liposome systems without a membrane phase transition were also found to experience permeability increases but, in contrast, this response was temperature independent. The above results indicate that field-enhanced drug release occurs in liposome vesicles that possess a Tc as well as non-Tc liposomes. Additional studies extend non-Tc liposome responses to the in vivo case in which microwaves trigger Gentamicin release from a liposome ''depot'' placed subcutaneously in the rat hind leg. In addition, evidence is provided that cell surface sequestered liposomes can be triggered by microwave fields to release drugs directly into target cells. 24 refs., 6 figs

  8. Quantum chemical calculation and experimental measurement of the 13C chemical shift tensors of vanillin and 3,4-dimethoxybenzaldehyde

    Science.gov (United States)

    Zheng, Guang; Hu, Jianzhi; Zhang, Xiaodong; Shen, Lianfang; Ye, Chaohui; Webb, Graham A.

    1997-03-01

    The principal values of the 13C nuclear magnetic resonance chemical shift tensors in vanillin and 3,4-dimethoxybenzaldehyde are reported. Theoretical results of the 13C chemical shift tensors were obtained by employing the gauge included atomic orbital (GIAO) approach. The geometrical parameters were optimized by using the MNDO method. The observed chemical shifts of these two compounds were determined in powders by using the recently introduced magic angle turning (MAT) experiment. The results presented in this paper clearly demonstrate the importance of using tensor information in the study of molecular structures.

  9. Single particle measurements of the chemical composition of cirrus ice residue during CRYSTAL-FACE

    Science.gov (United States)

    Cziczo, D. J.; Murphy, D. M.; Hudson, P. K.; Thomson, D. S.

    2004-02-01

    The first real-time, in situ, investigation of the chemical composition of the residue of cirrus ice crystals was performed during July 2002. This study was undertaken on a NASA WB-57F high-altitude research aircraft as part of CRYSTAL-FACE, a field campaign which sought to further our understanding of the relation of clouds, water vapor, and climate by characterizing, among other parameters, anvil cirrus formed about the Florida peninsula. A counter flow virtual impactor (CVI) was used to separate cirrus ice from the unactivated interstitial aerosol particles and evaporate condensed-phase water. Residual material, on a crystal-by-crystal basis, was subsequently analyzed using the NOAA Aeronomy Laboratory's Particle Analysis by Laser Mass Spectrometry (PALMS) instrument. Sampling was performed from 5 to 15 km altitude and from 12° to 28° north latitude within cirrus originating over land and ocean. Chemical composition measurements provided several important results. Sea salt was often incorporated into cirrus, consistent with homogeneous ice formation by aerosol particles from the marine boundary layer. Size measurements showed that large particles preferentially froze over smaller ones. Meteoritic material was found within ice crystals, indicative of a relation between stratospheric aerosol particles and tropospheric clouds. Mineral dust was the dominant residue observed in clouds formed during a dust transport event from the Sahara, consistent with a heterogeneous freezing mechanism. These results show that chemical composition and size are important determinants of which aerosol particles form cirrus ice crystals.

  10. In situ laser measurement of oxygen concentration and flue gas temperature utilizing chemical reaction kinetics.

    Science.gov (United States)

    Viljanen, J; Sorvajärvi, T; Toivonen, J

    2017-12-01

    Combustion research requires detailed localized information on the dynamic combustion conditions to improve the accuracy of the simulations and, hence, improve the performance of the combustion processes. We have applied chemical reaction kinetics of potassium to measure the local temperature and O 2 concentration in flue gas. An excess of free atomic potassium is created in the measurement volume by a photofragmenting precursor molecule such as potassium chloride or KOH which are widely released from solid fuels. The decay of the induced potassium concentration is followed with an absorption measurement using a narrow-linewidth diode laser. The temperature and O 2 concentration are solved from the decay curve features using equations obtained from calibration measurements in a temperature range of 800°C-1000°C and in O 2 concentrations of 0.1%-21%. The local flue gas temperature and O 2 concentration were recorded in real time during devolatilization, char burning, and ash cooking phases of combustion in a single-particle reactor with a 5 Hz repetition rate. The method can be further extended to other target species and applications where the chemical dynamics can be disturbed with photofragmentation.

  11. Measuring the chemical and cytotoxic variability of commercially available kava (Piper methysticum G. Forster.

    Directory of Open Access Journals (Sweden)

    Amanda C Martin

    Full Text Available Formerly used world-wide as a popular botanical medicine to reduce anxiety, reports of hepatotoxicity linked to consuming kava extracts in the late 1990s have resulted in global restrictions on kava use and have hindered kava-related research. Despite its presence on the United States Food and Drug Administration consumer advisory list for the past decade, export data from kava producing countries implies that US kava imports, which are not publicly reported, are both increasing and of a fairly high volume. We have measured the variability in extract chemical composition and cytotoxicity towards human lung adenocarcinoma A549 cancer cells of 25 commercially available kava products. Results reveal a high level of variation in chemical content and cytotoxicity of currently available kava products. As public interest and use of kava products continues to increase in the United States, efforts to characterize products and expedite research of this potentially useful botanical medicine are necessary.

  12. Observation operator for the assimilation of aerosol type resolving satellite measurements into a chemical transport model

    Directory of Open Access Journals (Sweden)

    M. Schroedter-Homscheidt

    2010-11-01

    Full Text Available Modelling of aerosol particles with chemical transport models is still based mainly on static emission databases while episodic emissions cannot be treated sufficiently. To overcome this situation, a coupling of chemical mass concentration modelling with satellite-based measurements relying on physical and optical principles has been developed. This study deals with the observation operator for a component-wise assimilation of satellite measurements. It treats aerosol particles classified into water soluble, water insoluble, soot, sea salt and mineral dust containing aerosol particles in the atmospheric boundary layer as separately assimilated aerosol components. It builds on a mapping of aerosol classes used both in observation and model space taking their optical and chemical properties into account. Refractive indices for primary organic carbon particles, anthropogenic particles, and secondary organic species have been defined based on a literature review. Together with a treatment of different size distributions in observations and model state, this allows transforming the background from mass concentrations into aerosol optical depths. A two-dimensional, variational assimilation is applied for component-wise aerosol optical depths. Error covariance matrices are defined based on a validation against AERONET sun photometer measurements. Analysis fields are assessed threefold: (1 through validation against AERONET especially in Saharan dust outbreak situations, (2 through comparison with the British Black Smoke and Sulphur Dioxide Network for soot-containing particles, and (3 through comparison with measurements of the water soluble components SO4, NH4, and NO3 conducted by the EMEP (European Monitoring and Evaluation Programme network. Separately, for the water soluble, the soot and the mineral dust aerosol components a bias reduction and subsequent a root mean square error reduction is observed in the

  13. Effect of dimethylamine on the gas phase sulfuric acid concentration measured by Chemical Ionization Mass Spectrometry.

    Science.gov (United States)

    Rondo, L; Ehrhart, S; Kürten, A; Adamov, A; Bianchi, F; Breitenlechner, M; Duplissy, J; Franchin, A; Dommen, J; Donahue, N M; Dunne, E M; Flagan, R C; Hakala, J; Hansel, A; Keskinen, H; Kim, J; Jokinen, T; Lehtipalo, K; Leiminger, M; Praplan, A; Riccobono, F; Rissanen, M P; Sarnela, N; Schobesberger, S; Simon, M; Sipilä, M; Smith, J N; Tomé, A; Tröstl, J; Tsagkogeorgas, G; Vaattovaara, P; Winkler, P M; Williamson, C; Wimmer, D; Baltensperger, U; Kirkby, J; Kulmala, M; Petäjä, T; Worsnop, D R; Curtius, J

    2016-03-27

    Sulfuric acid is widely recognized as a very important substance driving atmospheric aerosol nucleation. Based on quantum chemical calculations it has been suggested that the quantitative detection of gas phase sulfuric acid (H 2 SO 4 ) by use of Chemical Ionization Mass Spectrometry (CIMS) could be biased in the presence of gas phase amines such as dimethylamine (DMA). An experiment (CLOUD7 campaign) was set up at the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber to investigate the quantitative detection of H 2 SO 4 in the presence of dimethylamine by CIMS at atmospherically relevant concentrations. For the first time in the CLOUD experiment, the monomer sulfuric acid concentration was measured by a CIMS and by two CI-APi-TOF (Chemical Ionization-Atmospheric Pressure interface-Time Of Flight) mass spectrometers. In addition, neutral sulfuric acid clusters were measured with the CI-APi-TOFs. The CLOUD7 measurements show that in the presence of dimethylamine (sulfuric acid monomer measured by the CIMS represents only a fraction of the total H 2 SO 4 , contained in the monomer and the clusters that is available for particle growth. Although it was found that the addition of dimethylamine dramatically changes the H 2 SO 4 cluster distribution compared to binary (H 2 SO 4 -H 2 O) conditions, the CIMS detection efficiency does not seem to depend substantially on whether an individual H 2 SO 4 monomer is clustered with a DMA molecule. The experimental observations are supported by numerical simulations based on A Self-contained Atmospheric chemistry coDe coupled with a molecular process model (Sulfuric Acid Water NUCleation) operated in the kinetic limit.

  14. Rigorous evaluation of chemical measurement uncertainty: liquid chromatographic analysis methods using detector response factor calibration

    Science.gov (United States)

    Toman, Blaza; Nelson, Michael A.; Bedner, Mary

    2017-06-01

    Chemical measurement methods are designed to promote accurate knowledge of a measurand or system. As such, these methods often allow elicitation of latent sources of variability and correlation in experimental data. They typically implement measurement equations that support quantification of effects associated with calibration standards and other known or observed parametric variables. Additionally, multiple samples and calibrants are usually analyzed to assess accuracy of the measurement procedure and repeatability by the analyst. Thus, a realistic assessment of uncertainty for most chemical measurement methods is not purely bottom-up (based on the measurement equation) or top-down (based on the experimental design), but inherently contains elements of both. Confidence in results must be rigorously evaluated for the sources of variability in all of the bottom-up and top-down elements. This type of analysis presents unique challenges due to various statistical correlations among the outputs of measurement equations. One approach is to use a Bayesian hierarchical (BH) model which is intrinsically rigorous, thus making it a straightforward method for use with complex experimental designs, particularly when correlations among data are numerous and difficult to elucidate or explicitly quantify. In simpler cases, careful analysis using GUM Supplement 1 (MC) methods augmented with random effects meta analysis yields similar results to a full BH model analysis. In this article we describe both approaches to rigorous uncertainty evaluation using as examples measurements of 25-hydroxyvitamin D3 in solution reference materials via liquid chromatography with UV absorbance detection (LC-UV) and liquid chromatography mass spectrometric detection using isotope dilution (LC-IDMS).

  15. Synthetic Biology of Cyanobacteria: Unique Challenges and Opportunities

    Directory of Open Access Journals (Sweden)

    Bertram M Berla

    2013-08-01

    Full Text Available Photosynthetic organisms, and especially cyanobacteria, hold great promise as sources of renewably-produced fuels, bulk and specialty chemicals, and nutritional products. Synthetic biology tools can help unlock cyanobacteria’s potential for these functions, but unfortunately tool development for these organisms has lagged behind that for S. cerevisiae and E. coli. While these organisms may in many cases be more difficult to work with as ‘chassis’ strains for synthetic biology than certain heterotrophs, the unique advantages of autotrophs in biotechnology applications as well as the scientific importance of improved understanding of photosynthesis warrant the development of these systems into something akin to a ‘green E. coli’. In this review, we highlight unique challenges and opportunities for development of synthetic biology approaches in cyanobacteria. We review classical and recently developed methods for constructing targeted mutants in various cyanobacterial strains, and offer perspective on what genetic tools might most greatly expand the ability to engineer new functions in such strains. Similarly, we review what genetic parts are most needed for the development of cyanobacterial synthetic biology. Finally, we highlight recent methods to construct genome-scale models of cyanobacterial metabolism and to use those models to measure properties of autotrophic metabolism. Throughout this paper, we discuss some of the unique challenges of a diurnal, autotrophic lifestyle along with how the development of synthetic biology and biotechnology in cyanobacteria must fit within those constraints.

  16. 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 ...

  17. Determination of low isotopic enrichment of L-[1-C-13]valine by gas chromatography combustion isotope ratio mass spectrometry : a robust method for measuring protein fractional synthetic rates in vivo

    NARCIS (Netherlands)

    Reijngoud, DJ; Hellstern, G; Elzinga, H; de Sain-van der Velden, MG; Okken, A; Stellaard, F

    A method was developed for measuring protein fractional synthetic rates using the N-methoxycarbonylmethyl ester (MCM) derivative of L-[1-C-13]valine and on-line gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). The derivatization procedure can be performed rapidly and GC

  18. Comparison of the two-dimensional directional wave spectra retrieved from spaceborne synthetic aperture radar images using the MPI scheme against directional buoy measurements

    Directory of Open Access Journals (Sweden)

    Nelson Violante-Carvalho

    2004-09-01

    Full Text Available Spaceborne Synthetic Aperture Radar (SAR is to date the only source of two-dimensional directional wave spectra with continuous and global coverage when operated in the so-called SAR Wave Mode (SWM. Since the launch in 1991 of the first European Remote Sensing Satellite ERS-1, and more recently with ENVISAT, millions of SWM imagettes containing detailed spectral information are now available in quasi-real time. This huge amount of directional wave data has opened up many exciting possibilities for the improvement of our knowledge of the dynamics of ocean waves. However, the retrieval of wave spectra from SAR images is not a trivial exercise due to the nonlinearities involved in the mapping mechanism. In this paper we review the main features of the SAR ocean wave imaging mechanisms and give a detailed description of the Max-Planck Institut (MPI retrieval algorithm which is running operationally at the European Centre for Medium-Range Weather Forecasts (ECMWF. Some examples of retrieved spectra are compared against directional buoy measurements obtained in deep water in the South Atlantic and against WAM spectra. The main characteristics of the MPI retrieval scheme are discussed and some of its deficiencies and strengths are identified.

  19. Suitability of Optical, Physical and Chemical Measurements for Detection of Changes in Bacterial Drinking Water Quality

    Science.gov (United States)

    Ikonen, Jenni; Pitkänen, Tarja; Miettinen, Ilkka T.

    2013-01-01

    In this study, different optical, physical and chemical measurements were tested for their capacity to detect changes in water quality. The tests included UV-absorbance at 254 nm, absorbance at 420 nm, turbidity, particle counting, temperature, pH, electric conductivity (EC), free chlorine concentration and ATP concentration measurements. Special emphasis was given to investigating the potential for measurement tools to detect changes in bacterial concentrations in drinking water. Bacterial colony counts (CFU) and total bacterial cell counts (TBC) were used as reference methods for assessing the bacterial water quality. The study consists of a series of laboratory scale experiments: monitoring of regrowth of Pseudomonas fluorescens, estimation of the detection limits for optical measurements using Escherichia coli dilutions, verification of the relationships by analysing grab water samples from various distribution systems and utilisation of the measurements in the case of an accidentally contaminated distribution network. We found significant correlations between the tested measurements and the bacterial water quality. As the bacterial contamination of water often co-occurs with the intrusion of matrixes containing mainly non-bacterial components, the tested measurement tools can be considered to have the potential to rapidly detect any major changes in drinking water quality. PMID:24284353

  20. Measuring the Chemical Potential of the Martian Regolith to Generate and Sustain Life

    Science.gov (United States)

    Kounaves, S. P.; Buehler, M. G.; Kuhlman, K. R.

    1999-01-01

    such, requires an aqueous environment. Deciphering die chemical speciation of this aqueous environment is the key to recognizing therein the biosignatures of any extinct or present life forms. Identifying the soluble (ionic and nonionic) components by reacting a currently dormant environment can provide a "picture" of the thermodynamics and chemical components of a possibly bioactive environment. The only devices which can provide such information are electrochemical sensors based on the potentiometric ion selective electrodes (ISEs) and on dynamic techniques such as cyclic voltammetry (CV) and stripping voltammetry (SV). Such an array of devices can provide not only the chemical composition of a water-soluble Martian soil sample, but also several other vital chemical parameters such as pH, conductivity, redox potential, and dissolved gases. To address these issues we have been investigating the possible use of an electrochemically-based ion sensor array as a new integrated approach to quantitative analytical and chemometric electrochemical measurements. The sensor array will consist of specific and semispecific ion selective and amperometric transducers, which can simultaneously and continuously identify and semiquantitatively determine over 50 organic and inorganic analytes in water-based environments. Several individual sensors, based on the same principle, have been flight-tested and have been installed as part of the MECA instrumentation on the Mars 2001 Lander for in-situ analyses. However, the microfabrication, integration and multiplexing of such a large number of these sensors on a single substrate have not been previously attempted.

  1. Chemical composition of aerosol measurements in the air pollution plume during KORUS-AQ

    Science.gov (United States)

    Park, T.; Lee, J. B.; Lim, Y. J.; Ahn, J.; Park, J. S.; Soo, C. J.; Kim, J.; Park, S.; Lee, Y.; Desyaterik, Y.; Collett, J. L., Jr.; Lee, T.

    2017-12-01

    The Korean peninsula is a great place to study different sources of the aerosols: urban, rural and marine. In addition, Seoul is one of the large metropolitan areas in the world and has a variety of sources because half of the Korean population lives in Seoul, which comprises only 12% of the country's area. To understand the chemical composition of aerosol form long-range transport and local sources better, an Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) was deployed on an airborne platform (NASA DC-8 aircraft). The HR-ToF-AMS is capable of measuring non-refractory size resolved chemical composition of submicron particle(NR-PM1) in the air pollution plume, including mass concentration of organic carbon, nitrate, sulfate, and ammonium with 10 seconds time resolution. The measurements were performed twenty times research flight for understanding characteristic of the air pollution from May to June, 2016 on the South Korean peninsula during KORUS-AQ 2016 campaign. The scientific goal of this study is to characterize aerosol chemical properties and mass concentration in order to understand the role of the long-range transport from northeast Asia to South Korea, and influence of the local sources. To brief, organics dominated during all of flights. Also, organics and nitrate were dominant around energy industrial complex near by Taean, South Korea. The presentation will provide an overview of the composition of NR-PM1 measured in air pollution plumes, and deliver detail information about width, depth and spatial distribution of the pollutant in the air pollution plumes. The results of this study will provide high temporal and spatial resolved details on the air pollution plumes, which are valuable input parameters of aerosol properties for the current air quality models.

  2. A Brine Shrimp Bioassay for Measuring Toxicity and Remediation of Chemicals

    Science.gov (United States)

    Lieberman, Marya

    1999-12-01

    A bioassay using Artemia franciscana (brine shrimp) was adapted to measure the toxicity of household chemicals. One project is described in which students collect dose-response curves for seven commercial flea-killing products. Next, groups of students researched the insecticidal ingredients of the flea products. On the basis of the structures of the active ingredients, they chose remediation methods to make the flea product less toxic to brine shrimp; procedures included copper-catalyzed hydrolysis, adsorption onto activated charcoal, bleach treatment, and photodegradation. No special equipment or supplies are necessary for the bioassay other than the brine shrimp eggs, which can be obtained at any aquarium store.

  3. Simulation of the Battery Pack Exploitation Based on Real Measurement Data of Applied Chemical Cells

    Directory of Open Access Journals (Sweden)

    Koniak Marcin

    2016-01-01

    Full Text Available Authors of following article present the method of battery work simulation based on real measurement data of applied chemical cells and workload data. Description of method as its assumptions are presented. Next authors present workplace designed and constructed for acquiring operating characteristics according to assumed research plan. Article introduces computer system responsible for running simulations. At the end of publication results of selected runs are presented. Also described are types of tested cells and means of acquiring data concerning battery workload. Article ends with summarization and approximate plans of method development.

  4. Measurements and models for hazardous chemical and mixed wastes. 1998 annual progress report

    International Nuclear Information System (INIS)

    Holcomb, C.; Louie, B.; Mullins, M.E.; Outcalt, S.L.; Rogers, T.N.; Watts, L.

    1998-01-01

    'Aqueous waste of various chemical compositions constitutes a significant fraction of the total waste produced by industry in the US. A large quantity of the waste generated by the US chemical process industry is waste water. In addition, the majority of the waste inventory at DoE sites previously used for nuclear weapons production is aqueous waste. Large quantities of additional aqueous waste are expected to be generated during the clean-up of those sites. In order to effectively treat, safely handle, and properly dispose of these wastes, accurate and comprehensive knowledge of basic thermophysical property information is paramount. This knowledge will lead to huge savings by aiding in the design and optimization of treatment and disposal processes. The main objectives of this project are: Develop and validate models that accurately predict the phase equilibria and thermodynamic properties of hazardous aqueous systems necessary for the safe handling and successful design of separation and treatment processes for hazardous chemical and mixed wastes. Accurately measure the phase equilibria and thermodynamic properties of a representative system (water + acetone + isopropyl alcohol + sodium nitrate) over the applicable ranges of temperature, pressure, and composition to provide the pure component, binary, ternary, and quaternary experimental data required for model development. As of May, 1998, nine months into the first year of a three year project, the authors have made significant progress in the database development, have begun testing the models, and have been performance testing the apparatus on the pure components.'

  5. Printability of Synthetic Papers by Electrophotography

    Directory of Open Access Journals (Sweden)

    Rozália Szentgyörgyvölgyi

    2010-04-01

    Full Text Available This paper deals with the printability of synthetic papers by the electrophotography technique. Prints of cmyk colour fields from 20% to 100% raster tone values were printed on three types of synthetic papers (one film synthetic paper and two fiber synthetic papers. The investigation of the appearance included densitometric measurement of the cmyk prints. The results have shown differences in the optical density and optical tone value between cmyk prints made on various synthetic papers. The highest optical density and the increase of the optical tone value were observed on the film synthetic paper, where cmyk prints were more saturated. The highest abrasion resistance of cmyk prints was obtained from the fibre synthetic paper.

  6. Introductory lecture: atmospheric organic aerosols: insights from the combination of measurements and chemical transport models.

    Science.gov (United States)

    Pandis, Spyros N; Donahue, Neil M; Murphy, Benjamin N; Riipinen, Ilona; Fountoukis, Christos; Karnezi, Eleni; Patoulias, David; Skyllakou, Ksakousti

    2013-01-01

    The formation, atmospheric evolution, properties, and removal of organic particulate matter remain some of the least understood aspects of atmospheric chemistry despite the importance of organic aerosol (OA) for both human health and climate change. Here, we summarize our recent efforts to deal with the chemical complexity of the tens of thousands of organic compounds in the atmosphere using the volatility-oxygen content framework (often called the 2D-Volatility Basis Set, 2D-VBS). Our current ability to measure the ambient OA concentration as a function of its volatility and oxygen to carbon (O:C) ratio is evaluated. The combination of a thermodenuder, isothermal dilution and Aerosol Mass Spectrometry (AMS) together with a mathematical aerosol dynamics model is a promising approach. The development of computational modules based on the 2D-VBS that can be used in chemical transport models (CTMs) is described. Approaches of different complexity are tested against ambient observations, showing the challenge of simulating the complex chemical evolution of atmospheric OA. The results of the simplest approach describing the net change due to functionalization and fragmentation are quite encouraging, reproducing both the observed OA levels and O : C in a variety of conditions. The same CTM coupled with source-apportionment algorithms can be used to gain insights into the travel distances and age of atmospheric OA. We estimate that the average age of OA near the ground in continental locations is 1-2 days and most of it was emitted (either as precursor vapors or particles) hundreds of kilometers away. Condensation of organic vapors on fresh particles is critical for the growth of these new particles to larger sizes and eventually to cloud condensation nuclei (CCN) sizes. The semivolatile organics currently simulated by CTMs are too volatile to condense on these tiny particles with high curvature. We show that chemical aging reactions converting these semivolatile

  7. Science with Synthetic Stellar Surveys

    Science.gov (United States)

    Sanderson, Robyn Ellyn

    2018-04-01

    A new generation of observational projects is poised to revolutionize our understanding of the resolved stellar populations of Milky-Way-like galaxies at an unprecedented level of detail, ushering in an era of precision studies of galaxy formation. In the Milky Way itself, astrometric, spectroscopic and photometric surveys will measure three-dimensional positions and velocities and numerous chemical abundances for stars from the disk to the halo, as well as for many satellite dwarf galaxies. In the Local Group and beyond, HST, JWST and eventually WFIRST will deliver pristine views of resolved stars. The groundbreaking scale and dimensionality of this new view of resolved stellar populations in galaxies challenge us to develop new theoretical tools to robustly compare these surveys to simulated galaxies, in order to take full advantage of our new ability to make detailed predictions for stellar populations within a cosmological context. I will describe a framework for generating realistic synthetic star catalogs and mock surveys from state-of-the-art cosmological-hydrodynamical simulations, and present several early scientific results from, and predictions for, resolved stellar surveys of our Galaxy and its neighbors.

  8. The geographical origin and chemical composition in phellinus mushrooms measured by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Lim, J.M.; Sun, G.M.; Moon, J.H.; Chung, Y.S.; Lee, J.H.; Kim, K.H.

    2012-01-01

    In order to expand the utilization of phellinus mushrooms as a dietary supplement, we attempted to evaluate the chemical composition by measuring its inorganic elemental content with the aid of instrumental neutron activation analysis (INAA). Twenty seven phellinus mushrooms samples were collected from Korea, Cambodia, and Vietnam. A total of 28 elements were analyzed in the phellinus mushroom samples using the INAA. The concentrations of Ca, K, and Mg are much higher than those of other elements in phellinus mushroom samples. The sum of determined elemental concentration in Cambodia samples was about 2-6 times higher than those in Korea and Vietnam samples, respectively. Based on our measurement data, we attempted to discriminate the geographical origin using principal components analysis (PCA) and linear discriminant analysis (LDA). The geographical origins of all samples were clearly classified with correct classification rate of 100%. (author)

  9. Technical Note: Quantification of interferences of wet chemical HONO LOPAP measurements under simulated polar conditions

    Directory of Open Access Journals (Sweden)

    J. Kleffmann

    2008-11-01

    Full Text Available In the present pilot study, an optimized LOPAP instrument (LOng Path Absorption Photometer for the detection of nitrous acid (HONO in the atmosphere (DL 0.2 pptV was tested at the high alpine research station Jungfraujoch at 3580 m altitude in the Swiss Alps under conditions comparable to polar regions. HONO concentrations in the range <0.5–50 pptV with an average of 7.5 pptV were observed at the Jungfraujoch. The diurnal profiles obtained exhibited clear maxima at noon and minima with very low concentration during the night supporting the proposed photochemical production of HONO. In good agreement with recent measurements at the South Pole, it was demonstrated, that interferences of chemical HONO instruments can significantly influence the measurements and lead to considerable overestimations, especially for low pollution level. Accordingly, the active correction of interferences is of paramount importance for the determination of reliable HONO data.

  10. Passivation of mechanically polished, chemically etched and anodized zirconium in various aqueous solutions: Impedance measurements

    International Nuclear Information System (INIS)

    Abo-Elenien, G.M.; Abdel-Salam, O.E.

    1987-01-01

    Zirconium and its alloys are finding increasing applications especially in water-cooled nuclear reactors. Because of the fact that zirconium is electronegative (E 0 = -1.529V) its corrosion resistance in aqueous solutions is largely determined by the existence of a thin oxide film on its surface. The structure and properties of this film depend in the first place on the method of surface pre-treatment. This paper presents an experimental study of the nature of the oxide film on mechanically polished, chemically etched and anodized zirconium. Ac impedance measurements carried out in various acidic, neutral and alkaline solutions show that the film thickness depends on the method of surface pre-treatment and the type of electrolyte solution. The variation of the potential and impedance during anodization of zirconium at low current density indicates that the initial stages of polarization consist of oxide build-up at a rate dependent on the nature of the electrode surface and the electrolyte. Oxygen evolution commences at a stage where oxide thickening starts to decline. The effect of frequency on the measured impedance indicates that the surface reactivity, and hence the corrosion rate, decreases in the following order: mechanically polished > chemically etched > anodized

  11. Final Report for SERDP Project RC-1649: Advanced Chemical Measurements of Smoke from DoD-prescribed Burns

    Science.gov (United States)

    T.J. Johnson; R.J. Yokelson; S.K. Akagi; I.R. Burling; D.R. Weise; S.P. Urbanski; C.E. Stockwell; J. Reardon; E.N. Lincoln; L.T.M. Profeta; A. Mendoza; M.D.W. Schneider; R.L. Sams; S.D. Williams; C.E. Wold; D.W.T. Griffith; M. Cameron; J.B. Gilman; C. Warneke; J.M. Roberts; P. Veres; W.C. Kuster; J de Gouw

    2014-01-01

    Project RC-1649, "Advanced Chemical Measurement of Smoke from DoD-prescribed Burns" was undertaken to use advanced instrumental techniques to study in detail the particulate and vapor-phase chemical composition of the smoke that results from prescribed fires used as a land management tool on DoD bases, particularly bases in the southeastern U.S. The statement...

  12. A millifluidic calorimeter with InfraRed thermography for the measurement of chemical reaction enthalpy and kinetics

    OpenAIRE

    Hany, Cindy; Pradere, Christophe; Toutain, Jean; Batsale, Jean-Christophe

    2012-01-01

    International audience; The aim of this work is to present an infrared calorimeter for the measurement of the kinetics and the enthalpy of high exothermic chemical reactions. The main idea is to use a millifluidic chip where the channel acts as a chemical reactor. An infrared camera is used to deduce the heat flux produced by the chemical reaction from the processing of temperature fields. Due to the size of the microchannel, a small volume of reagents (ml) is used. As the chemical reagents a...

  13. In vitro root caries progression measured by 125I absorptiometry: comparison with chemical analysis

    International Nuclear Information System (INIS)

    Almqvist, H.; Wefel, J.S.; Lagerloef, F.E.; Ekstrand, J.; Henrikson, C.O.

    1988-01-01

    Radiation from a 125 I source and a non-image-forming detector was used for non-destructive measurements of root caries progression. Blocks were cut parallel to the cementum surface of unexposed human roots. These blocks were then individually demineralized in under-saturated calcium phosphate solutions over an 84-hour period. In order for the in vitro root surface demineralization to be followed, the changes in transmission (delta T) through the blocks were measured, by 125 I absorptiometry, eight times during the course of the experiment. Chemical analyses of the calcium output (delta Ca) from the blocks into the demineralizing solutions were also performed, and the rate of demineralization (Vdem) was calculated from these values. The precision of 125 I absorptiometry was calculated from 176 duplicate transmission measurements, and the coefficient of variation was found to be 0.20%. The correlation coefficient between delta T and total delta Ca for each of 22 cementum/dentin blocks ranged between r = 0.934 and r = 0.998. The progression of root hard-tissue lesions observed by these two methods and by the calculated Vdem was found to be proportional to the square and cubic roots of time. The study shows that 125 I absorptiometry can be used for continuous non-destructive measurements of root hard-tissue demineralization in vitro

  14. A reliable control system for measurement on film thickness in copper chemical mechanical planarization system

    Science.gov (United States)

    Li, Hongkai; Qu, Zilian; Zhao, Qian; Tian, Fangxin; Zhao, Dewen; Meng, Yonggang; Lu, Xinchun

    2013-12-01

    In recent years, a variety of film thickness measurement techniques for copper chemical mechanical planarization (CMP) are subsequently proposed. In this paper, the eddy-current technique is used. In the control system of the CMP tool developed in the State Key Laboratory of Tribology, there are in situ module and off-line module for measurement subsystem. The in situ module can get the thickness of copper film on wafer surface in real time, and accurately judge when the CMP process should stop. This is called end-point detection. The off-line module is used for multi-points measurement after CMP process, in order to know the thickness of remained copper film. The whole control system is structured with two levels, and the physical connection between the upper and the lower is achieved by the industrial Ethernet. The process flow includes calibration and measurement, and there are different algorithms for two modules. In the process of software development, C++ is chosen as the programming language, in combination with Qt OpenSource to design two modules' GUI and OPC technology to implement the communication between the two levels. In addition, the drawing function is developed relying on Matlab, enriching the software functions of the off-line module. The result shows that the control system is running stably after repeated tests and practical operations for a long time.

  15. An electrospray chemical ionization source for real-time measurement of atmospheric organic and inorganic vapors

    Science.gov (United States)

    Zhao, Yue; Chan, Jeremy K.; Lopez-Hilfiker, Felipe D.; McKeown, Megan A.; D'Ambro, Emma L.; Slowik, Jay G.; Riffell, Jeffrey A.; Thornton, Joel A.

    2017-10-01

    We present an electrospray ion source coupled to an orthogonal continuous-flow atmospheric pressure chemical ionization region. The source can generate intense and stable currents of several specific reagent ions using a range of salt solutions prepared in methanol, thereby providing both an alternative to more common radioactive ion sources and allowing for the generation of reagent ions that are not available in current chemical ionization mass spectrometry (CIMS) techniques, such as alkaline cations. We couple the orthogonal electrospray chemical ionization (ESCI) source to a high-resolution time-of-flight mass spectrometer (HR-ToF-MS), and assess instrument performance through calibrations using nitric acid (HNO3), formic acid (HCOOH), and isoprene epoxydiol (trans-β-IEPOX) gas standards, and through measurements of oxidized organic compounds formed from ozonolysis of α-pinene in a continuous-flow reaction chamber. When using iodide as the reagent ion, the HR-ToF-ESCIMS prototype has a sensitivity of 11, 2.4, and 10 cps pptv-1 per million counts per second (cps) of reagent ions and a detection limit (3σ, 5 s averaging) of 4.9, 12.5, and 1.4 pptv to HNO3, HCOOH, and IEPOX, respectively. These values are comparable to those obtained using an iodide-adduct HR-ToF-CIMS with a radioactive ion source and low-pressure ion-molecule reaction region. Applications to the α-pinene ozonolysis system demonstrates that HR-ToF-ESCIMS can generate multiple reagent ions (e.g., I-, NO3-, acetate, Li+, Na+, K+, and NH4+) having different selectivity to provide a comprehensive molecular description of a complex organic system.

  16. An electrospray chemical ionization source for real-time measurement of atmospheric organic and inorganic vapors

    Directory of Open Access Journals (Sweden)

    Y. Zhao

    2017-10-01

    Full Text Available We present an electrospray ion source coupled to an orthogonal continuous-flow atmospheric pressure chemical ionization region. The source can generate intense and stable currents of several specific reagent ions using a range of salt solutions prepared in methanol, thereby providing both an alternative to more common radioactive ion sources and allowing for the generation of reagent ions that are not available in current chemical ionization mass spectrometry (CIMS techniques, such as alkaline cations. We couple the orthogonal electrospray chemical ionization (ESCI source to a high-resolution time-of-flight mass spectrometer (HR-ToF-MS, and assess instrument performance through calibrations using nitric acid (HNO3, formic acid (HCOOH, and isoprene epoxydiol (trans-β-IEPOX gas standards, and through measurements of oxidized organic compounds formed from ozonolysis of α-pinene in a continuous-flow reaction chamber. When using iodide as the reagent ion, the HR-ToF-ESCIMS prototype has a sensitivity of 11, 2.4, and 10 cps pptv−1 per million counts per second (cps of reagent ions and a detection limit (3σ, 5 s averaging of 4.9, 12.5, and 1.4 pptv to HNO3, HCOOH, and IEPOX, respectively. These values are comparable to those obtained using an iodide-adduct HR-ToF-CIMS with a radioactive ion source and low-pressure ion–molecule reaction region. Applications to the α-pinene ozonolysis system demonstrates that HR-ToF-ESCIMS can generate multiple reagent ions (e.g., I−, NO3−, acetate, Li+, Na+, K+, and NH4+ having different selectivity to provide a comprehensive molecular description of a complex organic system.

  17. 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.

  18. A comparison of plastic cable ties based on physical, chemical and stable isotopic measurements.

    Science.gov (United States)

    Nienaber, Lisa M; Cresswell, Sarah L; Carter, James F; Peter, Tony

    2018-01-01

    Plastic cable ties can be utilised in a range of serious criminal activities and a comparison of cable ties, or fragments, may form part of the physical evidence presented to a Court of law. This research assessed the potential value of evidence based on the analysis of plastic cable ties. Twenty packets of black coloured plastic cable ties (nominally 200mm×4.8mm) were purchased in pack sizes ranging from 25 to 100 individual cable ties (Brisbane, Australia, March 2015). Representative samples from each packet were visually examined, compared and tested to determine their physical dimensions, chemical compositions and stable isotopic compositions (δ 2 H, δ 13 C and δ 15 N). All of the individual cable ties from a given packet were found to be indistinguishable with respect to appearance, physical, chemical and isotopic measurements (within-batch variability). Individual cable ties were also found to be isotopically homogeneous with respect to hydrogen, carbon and nitrogen. All of the cable ties analysed were found to have very similar chemical compositions and to be manufactured predominantly from nylon 6,6. The elemental compositions of composite samples, prepared from each packet, were found to be highly variable and, as such, were of very limited value. Cable ties from ten of the twenty packets were uniquely characterised by physical appearance (between-batch variability). Physical measurements such as the width, thickness and tooth-count of the grip section did not provide additional discrimination. Cable ties from nineteen of the twenty packets were uniquely characterised by isotopic composition, based on δ 2 H and δ 15 N measurements. Samples from two packets of Crescent brand cable ties were found to be indistinguishable with respect to all of the tests applied in this study. These two packets were inadvertently purchased from the same retailer and had the same barcode and batch number. It was considered a reasonable assumption that these two packets

  19. Synthetic antifreeze peptide

    OpenAIRE

    1991-01-01

    A synthetic antifreeze peptide and a synthetic gene coding for the antifreeze peptide have been produced. The antifreeze peptide has a greater number of repeating amino acid sequences than is present in the native antifreeze peptides from winter flounder upon which the synthetic antifreeze peptide was modeled. Each repeating amino acid sequence has two polar amino acid residues which are spaced a controlled distance apart so that the antifreeze peptide may inhibit ice formation. The synthetic...

  20. Kinetics of Natural Attenuation: Review of the Critical Chemical Conditions and Measurements at Bore Scale

    Directory of Open Access Journals (Sweden)

    O. Atteia

    2002-01-01

    Full Text Available This paper describes the chemical conditions that should favour the biodegradation of organic pollutants. Thermodynamic considerations help to define the reaction that can occur under defined chemical conditions. The BTEX (benzene, toluene, ethylbenzene, and xylene degradation is focused on benzene, as it is the most toxic oil component and also because it has the slowest degradation rate under most field conditions. Several studies on benzene degradation allow the understanding of the basic degradation mechanisms and their importance in field conditions. The use of models is needed to interpret field data when transport, retardation, and degradation occur. A detailed comparison of two existing models shows that the limits imposed by oxygen transport must be simulated precisely to reach correct plumes shapes and dimensions, and that first-order kinetic approaches may be misleading. This analysis led us to develop a technique to measure directly biodegradation in the field. The technique to recirculate water at the borehole scale and the CO2 analysis are depicted. First results of biodegradation show that this technique is able to easily detect the degradation of 1 mg/l of hydrocarbons and that, in oxic media, a fast degradation rate of mixed fuel is observed.

  1. Chemical characterization and source apportionment of submicron aerosols measured in Senegal during the 2015 SHADOW campaign

    Science.gov (United States)

    Rivellini, Laura-Hélèna; Chiapello, Isabelle; Tison, Emmanuel; Fourmentin, Marc; Féron, Anaïs; Diallo, Aboubacry; N'Diaye, Thierno; Goloub, Philippe; Canonaco, Francesco; Prévôt, André Stephan Henry; Riffault, Véronique

    2017-09-01

    The present study offers the first chemical characterization of the submicron (PM1) fraction in western Africa at a high time resolution, thanks to collocated measurements of nonrefractory (NR) species with an Aerosol Chemical Speciation Monitor (ACSM), black carbon and iron concentrations derived from absorption coefficient measurements with a 7-wavelength Aethalometer, and total PM1 determined by a TEOM-FDMS (tapered element oscillating microbalance-filtered dynamic measurement system) for mass closure. The field campaign was carried out over 3 months (March to June 2015) as part of the SHADOW (SaHAran Dust Over West Africa) project at a coastal site located in the outskirts of the city of Mbour, Senegal. With an averaged mass concentration of 5.4 µg m-3, levels of NR PM1 in Mbour were 3 to 10 times lower than those generally measured in urban and suburban polluted environments. Nonetheless the first half of the observation period was marked by intense but short pollution events (NR PM1 concentrations higher than 15 µg m-3), sea breeze phenomena and Saharan desert dust outbreaks (PM10 up to 900 µg m-3). During the second half of the campaign, the sampling site was mainly under the influence of marine air masses. The air masses on days under continental and sea breeze influences were dominated by organics (36-40 %), whereas sulfate particles were predominant (40 %) for days under oceanic influence. Overall, measurements showed that about three-quarters of the total PM1 were explained by NR PM1, BC (black carbon) and Fe (a proxy for dust) concentrations, leaving approximately one-quarter for other refractory species. A mean value of 4.6 % for the Fe / PM1 ratio was obtained. Source apportionment of the organic fraction, using positive matrix factorization (PMF), highlighted the impact of local combustion sources, such as traffic and residential activities, which contribute on average to 52 % of the total organic fraction. A new organic aerosol (OA) source

  2. Chemical characterization and source apportionment of submicron aerosols measured in Senegal during the 2015 SHADOW campaign

    Directory of Open Access Journals (Sweden)

    L.-H. Rivellini

    2017-09-01

    Full Text Available The present study offers the first chemical characterization of the submicron (PM1 fraction in western Africa at a high time resolution, thanks to collocated measurements of nonrefractory (NR species with an Aerosol Chemical Speciation Monitor (ACSM, black carbon and iron concentrations derived from absorption coefficient measurements with a 7-wavelength Aethalometer, and total PM1 determined by a TEOM-FDMS (tapered element oscillating microbalance–filtered dynamic measurement system for mass closure. The field campaign was carried out over 3 months (March to June 2015 as part of the SHADOW (SaHAran Dust Over West Africa project at a coastal site located in the outskirts of the city of Mbour, Senegal. With an averaged mass concentration of 5.4 µg m−3, levels of NR PM1 in Mbour were 3 to 10 times lower than those generally measured in urban and suburban polluted environments. Nonetheless the first half of the observation period was marked by intense but short pollution events (NR PM1 concentrations higher than 15 µg m−3, sea breeze phenomena and Saharan desert dust outbreaks (PM10 up to 900 µg m−3. During the second half of the campaign, the sampling site was mainly under the influence of marine air masses. The air masses on days under continental and sea breeze influences were dominated by organics (36–40 %, whereas sulfate particles were predominant (40 % for days under oceanic influence. Overall, measurements showed that about three-quarters of the total PM1 were explained by NR PM1, BC (black carbon and Fe (a proxy for dust concentrations, leaving approximately one-quarter for other refractory species. A mean value of 4.6 % for the Fe ∕ PM1 ratio was obtained. Source apportionment of the organic fraction, using positive matrix factorization (PMF, highlighted the impact of local combustion sources, such as traffic and residential activities, which contribute on average to 52 % of the total organic

  3. [SYNTHETIC PEPTIDE VACCINES].

    Science.gov (United States)

    Sergeyev, O V; Barinsky, I F

    2016-01-01

    An update on the development and trials of synthetic peptide vaccines is reviewed. The review considers the successful examples of specific protection as a result of immunization with synthetic peptides using various protocols. The importance of conformation for the immunogenicity of the peptide is pointed out. An alternative strategy of the protection of the organism against the infection using synthetic peptides is suggested.

  4. Cell-free biology: exploiting the interface between synthetic biology and synthetic chemistry.

    Science.gov (United States)

    Harris, D Calvin; Jewett, Michael C

    2012-10-01

    Just as synthetic organic chemistry once revolutionized the ability of chemists to build molecules (including those that did not exist in nature) following a basic set of design rules, cell-free synthetic biology is beginning to provide an improved toolbox and faster process for not only harnessing but also expanding the chemistry of life. At the interface between chemistry and biology, research in cell-free synthetic systems is proceeding in two different directions: using synthetic biology for synthetic chemistry and using synthetic chemistry to reprogram or mimic biology. In the coming years, the impact of advances inspired by these approaches will make possible the synthesis of nonbiological polymers having new backbone compositions, new chemical properties, new structures, and new functions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Detection and measurement of land subsidence using interferometric synthetic aperture radar and Global Positioning System, San Bernardino County, Mojave Desert, California

    Science.gov (United States)

    Sneed, Michelle; Ikehara, Marti E.; Stork, Sylvia V.; Amelung, Falk; Galloway, Devin L.

    2003-01-01

    Land subsidence associated with ground-water-level declines has been recognized as a potential problem in parts of the Mojave Desert, California. Ground water has been the primary source of domestic, agricultural, and municipal water supplies in the desert since the early 1900s. Pumping of ground water from the Mojave River and Morongo ground-water basins in the southwestern Mojave Desert resulted in water-level declines of more than 30 meters (100 feet) between the 1950s and the 1990s. A Global Positioning System (GPS) survey of a geodetic network was used to determine the location, extent, and magnitude of vertical land-surface changes in Lucerne Valley in the Morongo ground-water basin. The GPS survey was conducted in 1998 to estimate historical elevation changes by comparing GPS-derived elevations with historical elevations (which were available for some of the monuments in the network as early as 1944) and to establish baseline values that can be used for comparisons with future GPS surveys. The GPS measurements indicated that about 600 millimeters (2 feet) [plus or minus 1,500 millimeters (5 feet)] of subsidence occurred at three of the monuments between 1969 and 1998 but that very little to no vertical change in position occurred at seven other monuments in the network. Water levels in the area of subsidence in Lucerne Valley declined about 15 meters (50 feet) during 1970-98. Interferometric synthetic aperture radar (InSAR) methods were used to characterize vertical land-surface changes in the Mojave River and Morongo ground-water basins during various intervals of time between 1992 and 1999. Interferograms, InSAR-generated displacement maps, show that subsidence ranging from 45 to 90 mm (0.15 to 0.3 ft) occurred in four areas of these two ground-water basins--the El Mirage, Lockhart-Harper Lake (dry), Newberry Springs, and Lucerne Valley areas. Some of the InSAR measurements were affected by the earthquakes at Landers and Hector Mine, California, and by

  6. Direct measurement of chemical composition of SOx in impact vapor using a laser gun

    Science.gov (United States)

    Ohno, Sohsuke; Kadono, Toshihiko; Kurosawa, Kosuke; Hamura, Taiga; Sakaiya, Tatsuhiro; Sugita, Seiji; Shigemori, Keisuke; Hironaka, Yoichiro; Watari, Takeshi; Matsui, Takafumi

    2011-06-01

    The SO3/SO2 ratio of the impact vapor cloud is a key parameter for understanding the environmental perturbation caused by the impact-induced SOx and the killing mechanism of. the mass extinction at the K-Pg boundary. We conducted hypervelocity impact experiments using a high-speed laser gun (GEKKO XII-HIPER, ILE, Osaka University) and measured the chemical compositions of the SOx released from CaSO4. The experimental result indicates that SOx are dominated by SO3. It implies that the SOx generated by the K-Pg impact would have been also dominated by SO3, because the SO3/SO2 ratio of natural planetary scale impact vapor clouds would have been larger than that of the experimental result of this study.

  7. A Novel Thermal Sensor for the Sensitive Measurement of Chemical Oxygen Demand.

    Science.gov (United States)

    Yao, Na; Liu, Zhuan; Chen, Ying; Zhou, Yikai; Xie, Bin

    2015-08-19

    A novel rapid methodology for determining the chemical oxygen demand (COD) based on a thermal sensor with a flow injection analysis system was proposed and experimentally validated. The ability of this sensor to detect and monitor COD was based on the degree of enthalpy increase when sodium hypochlorite reacted with the organic content in water samples. The measurement results were correlated with COD and were compared against the conventional method using potassium dichromate. The assay required only 5-7 min rather than the 2 h required for evaluation by potassium dichromate. The linear range was 5-1000 mg/L COD, and the limit of detection was very low, 0.74 mg/L COD. Moreover, this method exhibited high tolerance to chloride ions; 0.015 mol/L chloride ions had no influence on the response. Finally, the sensor was used to detect the COD of different water samples; the results were verified by the standard dichromate method.

  8. Speculative synthetic chemistry and the nitrogenase problem

    Science.gov (United States)

    Lee, Sonny C.; Holm, Richard H.

    2003-01-01

    There exist a limited but growing number of biological metal centers whose properties lie conspicuously outside the realm of known inorganic chemistry. The synthetic analogue approach, broadly directed, offers a powerful exploratory tool that can define intrinsic chemical possibilities for these sites while simultaneously expanding the frontiers of fundamental inorganic chemistry. This speculative application of analogue study is exemplified here in the evolution of synthetic efforts inspired by the cluster chemistry of biological nitrogen fixation. PMID:12642670

  9. Measurement of peroxy radicals by chemical ionization mass spectrometry with a corona ion source

    Science.gov (United States)

    Wang, Weihao; Tham, Yee Jun; Wang, Zhe; Tanner, David; Yu, Chuan; Wang, Tao

    2017-04-01

    Peroxy radicals including hydroperoxyl (HO2) and organic peroxy (RO2) radicals play key roles in atmospheric radical chemistry. However, accurate measurement of these radicals remains a challenge due to low concentration, strong activity and not well known intereference. Here we present the measurement of ambient peroxy (HO2+RO2) radicals at an urban site in Hong Kong using chemical ionization mass spectrometry (CIMS) with a corona ion source. The peroxy radicals are titrated by NO into OH and further converted into H2SO4, which is detected by the CIMS through the reaction with NO3- ions. Although the corona ion source has advantages as a non-radiative source and with a low cost, it has a higher background and is less stable compared to the widely used radioactive source. We have improved the design of the corona ion source. The detection limit for the corona ion source is 1×108 molecules/cm3 for an integration time of 1 min. Hexafluoropropylene (C3F6), which is widely used as OH scavenger, has been shown to produce HO2 through its reaction with OH in presence of high concentrations of NO, leading to high instrument background for HO2. The measurement results of ambient HO2 and RO2 during a photochemical episode will be presented.

  10. Assessment of insulation degradation of I and C cables from chemical and mechanical measurements

    International Nuclear Information System (INIS)

    Santhosh, T.V.; Ghosh, A.K.; Fernandes, B.G.

    2015-01-01

    Instrumentation and control (I and C) cables used in nuclear power plants (NPPs) are exposed to various deteriorative environmental effects during their operational lifetime. The factors consisting of long-term irradiation (at rather low dose rates, in the presence of oxygen), and enhanced temperature eventually result in insulation degradation. Monitoring of the actual state of the cable insulation and the prediction of their residual service life consist of the measurement of the properties that are directly proportional to the functionality of the cables (usually the elongation at break is used as the critical parameter). In view of this, accelerated thermal and radiation ageing of I and C cable insulation materials have been carried out and the degradation due to thermal and radiation ageing has been assessed using oxidation induction time (OIT) and oxidation induction temperature (OITp) measurements by differential scanning calorimetry (DSC). As elongation at break (EAB) is considered to be a benchmark characterization technique for polymeric materials, tensile tests have also been carried out on these cable materials to measure EAB for correlating with DSC findings. The scanning electron microscopy (SEM) performed on fresh and aged samples support relatively good correlation between chemical and mechanical properties. (author)

  11. A reference electrode based on polyvinyl butyral (PVB) polymer for decentralized chemical measurements

    International Nuclear Information System (INIS)

    Guinovart, Tomàs; Crespo, Gastón A.; Rius, F. Xavier; Andrade, Francisco J.

    2014-01-01

    Highlights: • A disposable solid-contact reference electrode for potentiometry is presented. • The device shows unsensitivity to most ions, redox potential and light. • Low-cost and good stability, ideal to build disposable potentiometric sensors. • Nanopores formed in the membrane control the flux of ions with the solution. - Abstract: A new solid-state reference electrode using a polymeric membrane of polyvinyl butyral (PVB), Ag/AgCl and NaCl to be used in decentralized chemical measurements is presented. The electrode is made by drop-casting the membrane cocktail onto a glassy carbon (GC) substrate. A stable potential (less than 1 mV dec −1 ) over a wide range of concentrations for the several chemical species tested is obtained. No significant influence to changes in redox potential, light and pH are observed. The response of this novel electrode shows good correlation when compared with a conventional double-junction reference electrode. Also good long-term stability (90 ± 33 μV/h) and a lifetime of approximately 4 months are obtained. Aspects related to the working mechanisms are discussed. Atomic Force Microscopy (AFM) studies reveal the presence of nanopores and channels on the surface, and electrochemical impedance spectroscopy (EIS) of optimized electrodes show low bulk resistances, usually in the kΩ range, suggesting that a nanoporous polymeric structure is formed in the interface with the solution. Future applications of this electrode as a disposable device for decentralized measurements are discussed. Examples of the utilization on wearable substrates (tattoos, fabrics, etc) are provided

  12. A reference electrode based on polyvinyl butyral (PVB) polymer for decentralized chemical measurements

    Energy Technology Data Exchange (ETDEWEB)

    Guinovart, Tomàs [Departament de Química Orgànica i Química Analítica, Universitat Rovira i Virgili, Carrer Marcellí Domingo s/n 43007 Tarragona (Spain); Crespo, Gastón A. [Department of Inorganic and Analytical Chemistry, University of Geneva, Quai Ernest-Ansermet 30, CH-1211 Geneva (Switzerland); Rius, F. Xavier [Departament de Química Orgànica i Química Analítica, Universitat Rovira i Virgili, Carrer Marcellí Domingo s/n 43007 Tarragona (Spain); Andrade, Francisco J., E-mail: franciscojavier.andrade@urv.cat [Departament de Química Orgànica i Química Analítica, Universitat Rovira i Virgili, Carrer Marcellí Domingo s/n 43007 Tarragona (Spain)

    2014-04-01

    Highlights: • A disposable solid-contact reference electrode for potentiometry is presented. • The device shows unsensitivity to most ions, redox potential and light. • Low-cost and good stability, ideal to build disposable potentiometric sensors. • Nanopores formed in the membrane control the flux of ions with the solution. Abstract: A new solid-state reference electrode using a polymeric membrane of polyvinyl butyral (PVB), Ag/AgCl and NaCl to be used in decentralized chemical measurements is presented. The electrode is made by drop-casting the membrane cocktail onto a glassy carbon (GC) substrate. A stable potential (less than 1 mV dec⁻¹ over a wide range of concentrations for the several chemical species tested is obtained. No significant influence to changes in redox potential, light and pH are observed. The response of this novel electrode shows good correlation when compared with a conventional double-junction reference electrode. Also good long-term stability (90 ± 33 μV/h) and a lifetime of approximately 4 months are obtained. Aspects related to the working mechanisms are discussed. Atomic Force Microscopy (AFM) studies reveal the presence of nanopores and channels on the surface, and electrochemical impedance spectroscopy (EIS) of optimized electrodes show low bulk resistances, usually in the kΩ range, suggesting that a nanoporous polymeric structure is formed in the interface with the solution. Future applications of this electrode as a disposable device for decentralized measurements are discussed. Examples of the utilization on wearable substrates (tattoos, fabrics, etc) are provided.

  13. Combining color chart, colorimetric measurement and chemical compounds for postharvest quality of white wine grapes.

    Science.gov (United States)

    Sollazzo, Marco; Baccelloni, Simone; D'Onofrio, Claudio; Bellincontro, Andrea

    2018-01-03

    This paper provides data for the potential use of a color chart to establish the best quality of white wine grapes destined for postharvest processing. Grechetto, Vermentino and Muscat of Alexandria white wine grape varieties were tested by sampling berries at different dates during their quality attribute evolution. A color chart and reflectance spectrocolorimeter were used in combination with analyses of total carotenoids and chlorophylls in all three varieties and of volatile organic compounds (VOCs) in Grechetto alone. Total carotenoids decreased from 0.85 to 0.76 µg g -1 in Grechetto berries and from 0.70 to 0.46 µg g -1 in Vermentino berries while increased from 0.70 to 0.80 µg g -1 in Muscat berries during ripening. Total chlorophylls decreased in all varieties, and a strict correlation was found between hue angle (measured by color chart or spectrocolorimeter) and chlorophyll disappearance, with R 2 ranging from 0.81 to 0.95 depending on the variety. VOCs were only measured in Grechetto grapes, and a significant increase in glycosylation was found with ripening. The concentration of different classes of VOCs exhibited a clear decrease during ripening, except for terpenoids and esters which showed a peak at the beginning. The benzenoid class reached the highest concentration, which was almost 50% of the total. Cluster analysis using Ward's method enabled the best grape quality to be identified. This experimental work highlights that a color chart is cheap and easy to use to define the right quality stage for white wine grapes. The color chart enabled the enochemical features to be matched with the VOC results for the aromatic maturity of Grechetto. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  14. Prescription launching related to the chemical measurement methods in the waste and environmental field with regards to the regulation framework dedicated to the NPP chemical releases

    Energy Technology Data Exchange (ETDEWEB)

    Pierre, M.; Dupin, M.; Cosse, C.; Lepetit, D.; Gacon, A. [EDF/Ceidre/DLAB, Avoine (France)

    2010-07-01

    At the present time, chemical analytical methods are elaborated by EDF Corporate Laboratories and then transmitted to the NPP laboratories for them to decline these procedures to fit with their own analytical devices. In fact, the feedback linked to the exceedings of the regulatory release thresholds pointed out that some differences in the chemical releases regarding several chemical substances could be attributed to the measurement channel. In some cases, one can exhibit a significant increase concerning some NPP chemical releases which can be due to modifications inherent to preservation methods and/or sample analyses. In 2004, this context lead EDF Nuclear Generation Corporate Division supported by NPP Representatives to prescribe the chemical analytical methods in the effluents and environment field and to standardise the dedicated chemical analytical devices. Several goals are carried on : To develop reliable, simple, rapid and applicable on site procedures which are congruent with the existing standards or with a simple adaptation of the standardised method when the standard is not directly applicable or does not fit; To standardise the dedicated analytical devices already available or available at a reasonable investment; To encourage an optimisation of the human resources; and, Health potential problems are also taken into account in the choice of the chemical reagents to be used in the analytical procedures. Other positive consequences can be pointed out concerning the regulatory framework, that is to say a consolidation with regards to the documents linked to the new requests exhibited in the NPP new licences for waste releases and water supply. For the citizens, it reinforces the confidence in the efficiency of the releases surveillance. (author)

  15. Prescription launching related to the chemical measurement methods in the waste and environmental field with regards to the regulation framework dedicated to the NPP chemical releases

    International Nuclear Information System (INIS)

    Pierre, M.; Dupin, M.; Cosse, C.; Lepetit, D.; Gacon, A.

    2010-01-01

    At the present time, chemical analytical methods are elaborated by EDF Corporate Laboratories and then transmitted to the NPP laboratories for them to decline these procedures to fit with their own analytical devices. In fact, the feedback linked to the exceedings of the regulatory release thresholds pointed out that some differences in the chemical releases regarding several chemical substances could be attributed to the measurement channel. In some cases, one can exhibit a significant increase concerning some NPP chemical releases which can be due to modifications inherent to preservation methods and/or sample analyses. In 2004, this context lead EDF Nuclear Generation Corporate Division supported by NPP Representatives to prescribe the chemical analytical methods in the effluents and environment field and to standardise the dedicated chemical analytical devices. Several goals are carried on : To develop reliable, simple, rapid and applicable on site procedures which are congruent with the existing standards or with a simple adaptation of the standardised method when the standard is not directly applicable or does not fit; To standardise the dedicated analytical devices already available or available at a reasonable investment; To encourage an optimisation of the human resources; and, Health potential problems are also taken into account in the choice of the chemical reagents to be used in the analytical procedures. Other positive consequences can be pointed out concerning the regulatory framework, that is to say a consolidation with regards to the documents linked to the new requests exhibited in the NPP new licences for waste releases and water supply. For the citizens, it reinforces the confidence in the efficiency of the releases surveillance. (author)

  16. Synergistic Synthetic Biology: Units in Concert

    Science.gov (United States)

    Trosset, Jean-Yves; Carbonell, Pablo

    2013-01-01

    Synthetic biology aims at translating the methods and strategies from engineering into biology in order to streamline the design and construction of biological devices through standardized parts. Modular synthetic biology devices are designed by means of an adequate elimination of cross-talk that makes circuits orthogonal and specific. To that end, synthetic constructs need to be adequately optimized through in silico modeling by choosing the right complement of genetic parts and by experimental tuning through directed evolution and craftsmanship. In this review, we consider an additional and complementary tool available to the synthetic biologist for innovative design and successful construction of desired circuit functionalities: biological synergies. Synergy is a prevalent emergent property in biological systems that arises from the concerted action of multiple factors producing an amplification or cancelation effect compared with individual actions alone. Synergies appear in domains as diverse as those involved in chemical and protein activity, polypharmacology, and metabolic pathway complementarity. In conventional synthetic biology designs, synergistic cross-talk between parts and modules is generally attenuated in order to verify their orthogonality. Synergistic interactions, however, can induce emergent behavior that might prove useful for synthetic biology applications, like in functional circuit design, multi-drug treatment, or in sensing and delivery devices. Synergistic design principles are therefore complementary to those coming from orthogonal design and may provide added value to synthetic biology applications. The appropriate modeling, characterization, and design of synergies between biological parts and units will allow the discovery of yet unforeseeable, novel synthetic biology applications. PMID:25022769

  17. Synergistic Synthetic Biology: Units in Concert

    International Nuclear Information System (INIS)

    Trosset, Jean-Yves; Carbonell, Pablo

    2013-01-01

    Synthetic biology aims at translating the methods and strategies from engineering into biology in order to streamline the design and construction of biological devices through standardized parts. Modular synthetic biology devices are designed by means of an adequate elimination of cross-talk that makes circuits orthogonal and specific. To that end, synthetic constructs need to be adequately optimized through in silico modeling by choosing the right complement of genetic parts and by experimental tuning through directed evolution and craftsmanship. In this review, we consider an additional and complementary tool available to the synthetic biologist for innovative design and successful construction of desired circuit functionalities: biological synergies. Synergy is a prevalent emergent property in biological systems that arises from the concerted action of multiple factors producing an amplification or cancelation effect compared with individual actions alone. Synergies appear in domains as diverse as those involved in chemical and protein activity, polypharmacology, and metabolic pathway complementarity. In conventional synthetic biology designs, synergistic cross-talk between parts and modules is generally attenuated in order to verify their orthogonality. Synergistic interactions, however, can induce emergent behavior that might prove useful for synthetic biology applications, like in functional circuit design, multi-drug treatment, or in sensing and delivery devices. Synergistic design principles are therefore complementary to those coming from orthogonal design and may provide added value to synthetic biology applications. The appropriate modeling, characterization, and design of synergies between biological parts and units will allow the discovery of yet unforeseeable, novel synthetic biology applications.

  18. Steel desulphurization with synthetic slag

    Energy Technology Data Exchange (ETDEWEB)

    Heput, T.; Ardelean, E.; Socalici, A.; Maksay, S.; Gavanescu, A.

    2007-07-01

    Generally speaking, sulfur is considered a harmful element for steel quality, reason why all the technological steps are being taken in order to eliminate it from the metal bath. This paper deals with the influence of the chemical composition, on the slag quantity and of the batch stirring condition upon the desulfurization process in the casting ladle by treatment with synthetic slag. The experiments were made at an open-hearth plant with the steel tapping in two ladles (the desulfurization was made with synthetic slag at one ladle while the other one was considered standard) and at the electric steel plant and for the synthetic slag formation a mix was used, made, according to several receipts, of : lime (50-75%), fluorine (0-17%); bauxite (0-32%) and aluminous slag (8-22%). The data were processed in the calculation programs EXCEL and MATLAB, which resulted in a series of correlations between the desulfurization degree and the chemical composition of the slag, respectively the slag quantity both for the charges bubbled with Argon and the un bubbled ones. (Author) 5 refs.

  19. Laboratory Measurements of Synthetic Pyroxenes and their Mixtures with Iron Sulfides as Inorganic Refractory Analogues for Rosetta/VIRTIS' Surface Composition Analysis of 67P/CG

    Science.gov (United States)

    Markus, Kathrin; Arnold, Gabriele; Moroz, Ljuba; Henckel, Daniela; Kappel, David; Capaccioni, Fabrizio; Filacchione, Gianrico; Schmitt, Bernard; Tosi, Federico; Érard, Stéphane; Bockelee-Morvan, Dominique; Leyrat, Cedric; VIRTIS Team

    2016-10-01

    The Visible and InfraRed Thermal Imaging Spectrometer VIRTIS on board Rosetta provided 0.25-5.1 µm spectra of 67P/CG's surface (Capaccioni et al., 2015). Thermally corrected reflectance spectra display a low albedo of 0.06 at 0.65 µm, different red VIS and IR spectral slopes, and a broad 3.2 µm band. This absorption feature is due to refractory surface constituents attributed to organic components, but other refractory constituents influence albedo and spectral slopes. Possible contributions of inorganic components to spectral characteristics and spectral variations across the surface should be understood based on laboratory studies and spectral modeling. Although a wide range of silicate compositions was found in "cometary" anhydrous IDPs and cometary dust, Mg-rich crystalline mafic minerals are dominant silicate components. A large fraction of silicate grains are Fe-free enstatites and forsterites that are not found in terrestrial rocks but can be synthesized in order to provide a basis for laboratory studies and comparison with VIRTIS data. We report the results of the synthesis, analyses, and spectral reflectance measurements of Fe-free low-Ca pyroxenes (ortho- and clinoenstatites). These minerals are generally very bright and almost spectrally featureless. However, even trace amounts of Fe-ions produce a significant decrease in the near-UV reflectance and hence can contribute to slope variations. Iron sulfides (troilite, pyrrhotite) are among the most plausible phases responsible for the low reflectance of 67P's surface from the VIS to the NIR. The darkening efficiency of these opaque phases is strongly particle-size dependent. Here we present a series of reflectance spectra of fine-grained synthetic enstatite powders mixed in various proportions with iron sulfide powders. The influence of dark sulfides on reflectance in the near-UV to near-IR spectral ranges is investigated. This study can contribute to understand the shape of reflectance spectra of 67P

  20. Measurement of natural radioactivity in chemical fertilizer and agricultural soil: evidence of high alpha activity.

    Science.gov (United States)

    Ghosh, Dipak; Deb, Argha; Bera, Sukumar; Sengupta, Rosalima; Patra, Kanchan Kumar

    2008-02-01

    People are exposed to ionizing radiation from the radionuclides that are present in different types of natural sources, of which phosphate fertilizer is one of the most important sources. Radionuclides in phosphate fertilizer belonging to 232Th and 238U series as well as radioisotope of potassium (40K) are the major contributors of outdoor terrestrial natural radiation. The study of alpha activity in fertilizers, which is the first ever in West Bengal, has been performed in order to determine the effect of the use of phosphate fertilizers on human health. The data have been compared with the alpha activity of different types of chemical fertilizers. The measurement of alpha activity in surface soil samples collected from the cultivated land was also performed. The sampling sites were randomly selected in the cultivated land in the Midnapore district, which is the largest district in West Bengal. The phosphate fertilizer is widely used for large agricultural production, mainly potatoes. The alpha activities have been measured using solid-state nuclear track detectors (SSNTD), a very sensitive detector for alpha particles. The results show that alpha activity of those fertilizer and soil samples varies from 141 Bq/kg to 2,589 Bq/kg and from 109 Bq/kg to 660 Bq/kg, respectively. These results were used to estimate environmental radiation exposure on human health contributed by the direct application of fertilizers.

  1. Carbon-14, tritium, stable isotope and chemical measurements on thermal waters from the Tauranga region

    International Nuclear Information System (INIS)

    Stewart, M.K.; McGill, R.C.; Taylor, C.B.; Whitehead, N.E.; Downes, C.J.

    1984-03-01

    The chemical compositions of groundwater from the Tauranga region are affected to varying degrees by reducing conditions due to buried organic matter. The levels of some dissolved constituents are also affected by mixing with sea water contained within the rocks and by rock-water interaction. Dissolved gas compositions range from oxygen-bearing to methane-bearing reflecting the varying redox conditions. Excess air may be present but further experiments are necessary to confirm this. Apparent ages deduced from carbon-14 measurements (corrected using 12C dilution and 13C fractionation methods) range from 2-25,000 years, suggesting that some of the waters were recharged during late Pleistocene or early Holocene time. ΔD and Δ18 O values of the oldest waters are slightly more negative than those of younger samples; this may indicate recharge during a cooler climate, in agreement with the 14C ages. Very low but significantly non-zero tritium contents (TR=(0.007-0.059)+-0.007) were measured using the high tritium-enrichment facilities at INS and the very low-background counters at the University of Bern. The tritium is thought to derive from contamination or nuclear reactions in the aquifer rocks rather than from recharge water

  2. Chemically-Resolved Volatility Measurements of Organic Aerosol from Different Sources

    Science.gov (United States)

    Huffman, J. A.; Docherty, K. S.; Mohr, C.; Ulbrich, I. M.; Ziemann, P. J.; Onasch, T. B.; Jimenez, J. L.

    2009-04-01

    A newly modified fast temperature-stepping thermodenuder (TD) was coupled to a High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) for rapid quantification of chemically-resolved volatility of organic aerosols (OA) emitted from individual sources. The TD-AMS system was used to characterize primary OA (POA) from biomass burning, trash burning surrogates (paper and plastic), and meat cooking as well as chamber-generated secondary OA (SOA) from a-pinene and gasoline vapor. Almost all atmospheric models represent POA as non-volatile, with no allowance for evaporation upon heating or dilution, or condensation upon cooling. Our results indicate that all OAs observed show semi-volatile behavior and that most POAs are at least as volatile as SOA measured in urban environments. Biomass-burning OA (BBOA) exhibited a wide range of volatilities, but more often showed volatility similar to urban OA. Paper-burning resembles BBOA because of its high volatility and intermediate atomic oxygen-to-carbon (O/C) ratio, while meat-cooking OAs (MCOA) have consistently lower volatility than ambient OA. Chamber-generated SOA was significantly more volatile than urban SOA, challenging extrapolation of traditional laboratory volatility measurements to the atmosphere. Most OAs sampled show increasing O/C ratio and decreasing H/C (hydrogen-to-carbon) ratio with temperature, further indicating that more oxygenated OA components are less volatile.

  3. Long-term measurement of aerosol chemical composition in Athens, Greece.

    Science.gov (United States)

    Paraskevopoulou, Despina; Liakakou, Eleni; Theodosi, Christina; Gerasopoulos, Evangelos; Mihalopoulos, Nikolaos

    2014-05-01

    The collection of our samples was conducted for a period of five years (2008 - 2013) in Athens, Greece. The site is situated at the premises of the National Observatory of Athens on Penteli Hill, northeast Athens suburbs, and is considered an urban background station. The aim of our study was a first long-term estimation of the chemical mass closure of aerosol. For the purposes of the study, we applied three filter samplers during the sampling period: two Partisol FRM Model 2000 air samplers (one of them collecting PM10 and the other PM2.5 fractions of aerosol) and one Dichotomous Partisol auto-sampler (with PM2.5 and PM2.5-10 inlet). Aerosols were collected on Whatman QM-A quartz fiber filters and the mass of the collected samples was estimated by weighing the pre-combusted filters before and after sampling, under controlled conditions, using a microbalance. All quartz filters were analysed for organic (OC) and elemental carbon (EC) by a thermal - optical transmission technique. The concentration of water soluble organic carbon (WSOC) was defined for each filter using a total organic carbon analyzer, while the content in main water soluble ions (Cl-, Br-, NO-3, SO4-2, PO4-3, C2O4-2, NH4+, K+, Na+, Mg+2, Ca+2) was determined by ion chromatography. Additionally the filters were analyzed for trace metals by inductively coupled plasma optical emission spectrometry (ICP-OES). Aerosol chemical mass closure calculations were conducted for the PM2.5 fraction. The area of Athens is characterized by aged aerosol that can originate from the marine boundary layer, the European mainland and occasionally from North African desert areas. The contribution of dust and particulate organic matter on PM levels was estimated taking into consideration the location of the sampling site, while identification and evaluation of sources was performed. Additionally, non-sea salt concentrations of the main ions were estimated to complete the chemical closure in the extended area. According to

  4. Physico-chemical characterisation and sorption measurements of Cs, Sr, Ni, Eu, Th, Sn and Se on Opalinus clay from Mont Terri

    International Nuclear Information System (INIS)

    Lauber, Matthias; Baeyens, Bart; Bradbury, Michael H.

    2000-12-01

    Opalinus Clay is currently under investigation as a potential host rock for the disposal of high level and long-lived intermediate radioactive waste. A throughout physico-chemical characterisation was carried out on a bore core sample from the underground rock laboratory Mont Terri (Canton Jura). The results of these investigations indicate that the major characteristics (mineralogy, cation exchange capacity, cation occupancies, selectivity coefficients, chloride and sulphate inventories) were very similar to a different core sample, previously used for pore water modelling studies. It was concluded that the pore water compositions derived in the earlier studies were reliable and could be used in this work. The organic matter which dissolved from the Opalinus Clay rock was not humic or fulvic acids and the concentration remaining in the liquid phase in the sorption experiments was < 0.5 ppm C. The organic matter is therefore considered to have little or no influence on the sorption behaviour of the studied radionuclides. Redox potential measurements of the Opalinus Clay/synthetic pore water system inside the glove boxes indicated anoxic conditions. The main focus of the experimental work presented here is on the sorption behaviour of Cs (I), Sr (II), Ni (II), Eu (III), Th (IV), Sn (IV) and Se (IV) on Opalinus Clay equilibrated with synthetic pore waters at pH 6.3 and 8. Sorption isotherms were measured for Cs, Ni, Eu, Th and Se. Single point data were measured for Sr and Sn. For all radionuclides studied the sorption kinetics were measured first. The times required to complete the sorption on the Opalinus Clay varied between one day for Th and one month for Ni and Se. Within the concentration ranges under study the uptake of Cs, Ni, Eu and Se on Opalinus Clay was non-linear, whereas for Th a linear sorption behaviour was observed. For Ni, Eu and Th the sorption increased with increasing pH. For Cs a pH independent sorption behaviour was observed. The concentration

  5. A technique using high-flow, dichotomous filter packs for measuring major atmospheric chemical constituents

    Science.gov (United States)

    Bardwell, C. A.; Maben, J. R.; Hurt, J. A.; Keene, W. C.; Galloway, J. N.; Boatman, J. F.; Wellman, D. L.

    1990-06-01

    We developed a high-resolution technique to measure major reactive trace gases and the chemical composition of size-segregated aerosols in the troposphere as part of the 1988 Global Change Expedition/Coordinated Air-Sea Experiment/Western Atlantic Ocean Experiment. We sampled air over the western North Atlantic Ocean from the NOAA King Air research aircraft and NOAA ship Mt. Mitchell during July. Our system used filter packs containing an upstream, 90-mm quartz filter to collect particles followed by two 90-mm rayon filters impregnated with 10% K2C03-10% glycerol to collect alkaline reactive gases. Paired filter packs were exposed when the aircraft sampled the boundary layer. An upstream cyclone with a 50% aerodynamic cut radius of approximately 0.4 μm removed large particles from one of the filter-pack inlets. Air was sampled at an average rate of 0.12 m3 STP min-1 for the fine filter packs and 0.26 m3 STP min-1 for the total over intervals of 45 min to 90 min. Particulate-phase concentrations of major anions (SO42-, CH3SO3-, NO3-, Cl-) and organic species (HCOOt [HCOO- and HCOOH] and CH3COOt [CH3COO- and CH3COOH]) were measured by gradient elution ion chromatography; base cations (Ca2+, Mg2+, Na+, K+) by atomic-absorption spectroscopy; NH4+ by automated colorimetry; and H+ by glass electrode. We quantified SO2, HNO3, and HCl using two isocratic ion chromatography methods. This technique provided higher signal-to-noise ratios allowing increased temporal and spatial resolution, pH determination of particulate-phase filter extracts, and measurement of HCl on gas-phase filters.

  6. Eddy covariance flux measurements of ammonia by high temperature chemical ionisation mass spectrometry

    Directory of Open Access Journals (Sweden)

    J. Sintermann

    2011-03-01

    Full Text Available A system for fast ammonia (NH3 measurements with chemical ionisation mass spectrometry (CIMS based on a commercial Proton Transfer Reaction-Mass Spectrometer (PTR-MS is presented. It uses electron transfer reaction as ionisation pathway and features a drift tube of polyetheretherketone (PEEK and silica-coated steel. Heating the instrumental inlet and the drift tube to 180 °C enabled an effective time resolution of ~1 s and made it possible to apply the instrument for eddy covariance (EC measurements. EC fluxes of NH3 were measured over two agricultural fields in Oensingen, Switzerland, following fertilisations with cattle slurry. Air was aspirated close to a sonic anemometer at a flow of 100 STP L min−1 and was directed through a 23 m long 1/2" PFA tube heated to 150 °C to an air-conditioned trailer where the gas was sub-sampled from the large bypass stream. This setup minimised damping of fast NH3 concentration changes between the sampling point and the actual measurement. High-frequency attenuation loss of the NH3 fluxes of 20 to 40% was quantified and corrected for using an empirical ogive method. The instrumental NH3 background signal showed a minor interference with H2O which was characterised in the laboratory. The resulting correction of the NH3 flux after slurry spreading was less than 1‰. The flux detection limit of the EC system was about 5 ng m−2 s−1 while the accuracy of individual flux measurements was estimated 16% for the high-flux regime during these experiments. The NH3 emissions after broad spreading of the slurry showed an initial maximum of 150 μg m−2 s−1 with a fast decline in the following hours.

  7. Chemical Reductive Transformations of Synthetic Organic Compounds

    National Research Council Canada - National Science Library

    Peyton, Gary

    2001-01-01

    .... A kinetic model that was previously developed to describe the results of batch AOP treatment by H2O2/UV did not give satisfactory predictive results obtained when extended to describe flow experiments...

  8. A Measurement and Modeling Study of Hair Partition of Neutral, Cationic, and Anionic Chemicals.

    Science.gov (United States)

    Li, Lingyi; Yang, Senpei; Chen, Tao; Han, Lujia; Lian, Guoping

    2018-04-01

    Various neutral, cationic, and anionic chemicals contained in hair care products can be absorbed into hair fiber to modulate physicochemical properties such as color, strength, style, and volume. For environmental safety, there is also an interest in understanding hair absorption to wide chemical pollutants. There have been very limited studies on the absorption properties of chemicals into hair. Here, an experimental and modeling study has been carried out for the hair-water partition of a range of neutral, cationic, and anionic chemicals at different pH. The data showed that hair-water partition not only depends on the hydrophobicity of the chemical but also the pH. The partition of cationic chemicals to hair increased with pH, and this is due to their electrostatic interaction with hair increased from repulsion to attraction. For anionic chemicals, their hair-water partition coefficients decreased with increasing pH due to their electrostatic interaction with hair decreased from attraction to repulsion. Increase in pH did not change the partition of neutral chemicals significantly. Based on the new physicochemical insight of the pH effect on hair-water partition, a new quantitative structure property relationship model has been proposed, taking into account of both the hydrophobic interaction and electrostatic interaction of chemical with hair fiber. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  9. Physico-chemical measurements of CL-20 for environmental applications. Comparison with RDX and HMX.

    Science.gov (United States)

    Monteil-Rivera, Fanny; Paquet, Louise; Deschamps, Stéphane; Balakrishnan, Vimal K; Beaulieu, Chantale; Hawari, Jalal

    2004-01-30

    CL-20 is a polycyclic energetic nitramine, which may soon replace the monocyclic nitramines RDX and HMX, because of its superior explosive performance. Therefore, to predict its environmental fate, analytical and physico-chemical data must be made available. An HPLC technique was thus developed to measure CL-20 in soil samples based on the US Environmental Protection Agency method 8330. We found that the soil water content and aging (21 days) had no effect on the recoveries (>92%) of CL-20, provided that the extracts were kept acidic (pH 3). The aqueous solubility of CL-20 was poor (3.6 mg l(-1) at 25 degrees C) and increased with temperature to reach 18.5 mg l(-1) at 60 degrees C. The octanol-water partition coefficient of CL-20 (log KOW = 1.92) was higher than that of RDX (log KOW = 0.90) and HMX (log KOW = 0.16), indicating its higher affinity to organic matter. Finally, CL-20 was found to decompose in non-acidified water upon contact with glass containers to give NO2- (2 equiv.), N2O (2 equiv.), and HCOO- (2 equiv.). The experimental findings suggest that CL-20 should be less persistent in the environment than RDX and HMX.

  10. NSAID Antinociception Measured in a Chemical and a Thermal Assay in Mice

    Directory of Open Access Journals (Sweden)

    HF Miranda

    2001-01-01

    Full Text Available The antinociceptive activity of several nonsteroidal anti-inflammatory drugs (NSAIDs that were administered either intraperitoneally or intrathecally was assessed in mice by two algesiometric tests. The first was the writhing test, which assessed the abdominal constrictions that were induced by intraperitoneal acetic acid (a chemical test, and the second was the tail flick test, which measured pain responses to heat stimuli. The corresponding effective doses and their relative potencies were compared because these tests use different nociceptive stimuli with different transmission pathways. The intraperitoneal and intrathecal dose-response curves for the antinociception induced by every NSAID that was tested were parallel in the writhing test. In the tail flick test, however, only the intraperitoneal and intrathecal dose-response curves for ketoprofen, piroxicam, naproxen, nimesulide, paracetamol and diclofenac were parallel. The results obtained in this study confirm that NSAIDs possess different abilities to induce inhibition of cyclooxygenase, and they can be indirectly assessed by their different antinociceptive activities, depending on the algesiometric assays that are used. The antinociception of most NSAIDs might involve central mechanisms. The findings demonstrate the increasing importance of the spinal cord in processing and modulating nociceptive input, because intrathecal administration of NSAIDs is always more effective (in terms of potency than systemic administration; thus, the antinociceptive efficacy of NSAIDs strongly depends on the algesiometric assay that is used and on the type of the nociceptive stimulus to which the test subject is exposed.

  11. Le Châtelier's conjecture: Measurement of colloidal eigenstresses in chemically reactive materials

    Science.gov (United States)

    Abuhaikal, Muhannad; Ioannidou, Katerina; Petersen, Thomas; Pellenq, Roland J.-M.; Ulm, Franz-Josef

    2018-03-01

    Volume changes in chemically reactive materials, such as hydrating cement, play a critical role in many engineering applications that require precise estimates of stress and pressure developments. But a means to determine bulk volume changes in the absence of other deformation mechanisms related to thermal, pressure and load variations, is still missing. Herein, we present such a measuring devise, and a hybrid experimental-theoretical technique that permits the determination of colloidal eigenstresses. Applied to cementitious materials, it is found that bulk volume changes in saturated cement pastes at constant pressure and temperature conditions result from a competition of repulsive and attractive phenomena that originate from the relative distance of the solid particles - much as Henry Louis Le Châtelier, the father of modern cement science, had conjectured in the late 19th century. Precipitation of hydration products in confined spaces entails a repulsion, whereas the concurrent reduction in interparticle distance entails activation of attractive forces in charged colloidal particles. This cross-over from repulsion to attraction can be viewed as a phase transition between a liquid state (below the solid percolation) and the limit packing of hard spheres, separated by an energy barrier that defines the temperature-dependent eigenstress magnitude.

  12. 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.

  13. [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.

  14. Synthetic Cathinones ("Bath Salts")

    Science.gov (United States)

    ... cathinones? Behavioral therapy can be used to treat addiction to synthetic cathinones. Examples include: cognitive-behavioral therapy contingency management, or motivational incentives—providing rewards to ...

  15. Studies by nuclear and physico-chemical methods of tissue's metallic contamination located around biomaterials. Toxicity measurements of several biomaterials residual radioactivity

    International Nuclear Information System (INIS)

    Guibert, Geoffroy

    2004-01-01

    Implants used as biomaterials fulfill conditions of functionality, compatibility and occasionally bio-activity. There are four main families of biomaterials: metals and metal alloys, polymers, bio-ceramics and natural materials. Because of corrosion and friction in the human body, implants generate debris. These debris develop different problems: toxicity, inflammatory reactions, prosthetic unsealing by osseous dissolution. Nature, size, morphology and amount of debris are the parameters which have an influence on tissue response. We characterize metallic contamination coming from knee prosthesis into surrounding capsular tissue by depth migration, in vivo behaviours, content, size and nature of debris. The PIXE-RBS and STEM-EDXS methods, that we used, are complementary, especially about characterization scale. Debris contamination distributed in the whole articulation is very heterogeneous. Debris migrate on several thousands μm in tissue. Solid metallic particles, μm, are found in the most polluted samples, for both kinds of alloys TA6V and CrCoMo. In the mean volume analysed by PIXE, the in vivo mass ratios [Ti]/[V] and [Co]/[Cr] confirm the chemical stability of TA6V debris and chemical evolution of CrCoMo debris. Complementary measures of TA6V grains, on a nano-metric scale by STEM-EDXS, show a dissolution of coarse grain (μm) in smaller grains (nm). Locally, TA6V grains of a phase are detected and could indicate a preferential dissolution of β phase (grain boundaries) with dropping of Al and V, both toxic and carcinogenic elements. A thin target protocol development correlates PIXE and histological analysis on the same zone. This protocol allows to locate other pathologies in relationship with weaker metal contamination, μg/g, thanks to the great sensitivity of PIXE method. Harmlessness with respect to the residual radioactivity of several natural or synthetic biomaterials is established, using ultra low background noise γ detection system. (author)

  16. Physical and chemical characterization of urban winter-time aerosols by mobile measurements in Helsinki, Finland

    Science.gov (United States)

    Pirjola, Liisa; Niemi, Jarkko V.; Saarikoski, Sanna; Aurela, Minna; Enroth, Joonas; Carbone, Samara; Saarnio, Karri; Kuuluvainen, Heino; Kousa, Anu; Rönkkö, Topi; Hillamo, Risto

    2017-06-01

    A two-week measurement campaign by a mobile laboratory van was performed in urban environments in the Helsinki metropolitan area, Finland, in winter 2012, to obtain a comprehensive view on aerosol properties and sources. The abundances and physico-chemical properties of particles varied strongly in time and space, depending on the main sources of aerosols. Four major types of winter aerosol were recognized: 1) clean background aerosol with low particle number (Ntot) and lung deposited surface area (LDSA) concentrations due to marine air flows from the Atlantic Ocean; 2) long-range transported (LRT) pollution aerosol due to air flows from eastern Europe where the particles were characterized by the high contribution of oxygenated organic aerosol (OOA) and inorganic species, particularly sulphate, but low BC contribution, and their size distribution possessed an additional accumulation mode; 3) fresh smoke plumes from residential wood combustion in suburban small houses, these particles were characterized by high biomass burning organic aerosol (BBOA) and black carbon (BC) concentrations; and 4) fresh emissions from traffic while driving on busy streets in the city centre and on the highways during morning rush hours. This aerosol was characterized by high concentration of Ntot, LDSA, small particles in the nucleation mode, as well as high hydrocarbon-like organic aerosol (HOA) and BC concentrations. In general, secondary components (OOA, NO3, NH4, and SO4) dominated the PM1 chemical composition during the LRT episode accounting for 70-80% of the PM1 mass, whereas fresh primary emissions (BC, HOA and BBOA) dominated the local traffic and wood burning emissions. The major individual particle types observed with electron microscopy analysis (TEM/EDX) were mainly related to residential wood combustion (K/S/C-rich, soot, other C-rich particles), traffic (soot, Si/Al-rich, Fe-rich), heavy fuel oil combustion in heat plants or ships (S with V-Ni-Fe), LRT pollutants (S

  17. Chemically-resolved aerosol volatility measurements from two megacity field studies

    Directory of Open Access Journals (Sweden)

    J. A. Huffman

    2009-09-01

    Full Text Available The volatilities of different chemical species in ambient aerosols are important but remain poorly characterized. The coupling of a recently developed rapid temperature-stepping thermodenuder (TD, operated in the range 54–230°C with a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS during field studies in two polluted megacities has enabled the first direct characterization of chemically-resolved urban particle volatility. Measurements in Riverside, CA and Mexico City are generally consistent and show ambient nitrate as having the highest volatility of any AMS standard aerosol species while sulfate showed the lowest volatility. Total organic aerosol (OA showed volatility intermediate between nitrate and sulfate, with an evaporation rate of 0.6%·K−1 near ambient temperature, although OA dominates the residual species at the highest temperatures. Different types of OA were characterized with marker ions, diurnal cycles, and positive matrix factorization (PMF and show significant differences in volatility. Reduced hydrocarbon-like OA (HOA, a surrogate for primary OA, POA, oxygenated OA (OOA, a surrogate for secondary OA, SOA, and biomass-burning OA (BBOA separated with PMF were all determined to be semi-volatile. The most aged OOA-1 and its dominant ion, CO2+, consistently exhibited the lowest volatility, with HOA, BBOA, and associated ions for each among the highest. The similar or higher volatility of HOA/POA compared to OOA/SOA contradicts the current representations of OA volatility in most atmospheric models and has important implications for aerosol growth and lifetime. A new technique using the AMS background signal was demonstrated to quantify the fraction of species up to four orders-of-magnitude less volatile than those detectable in the MS mode, which for OA represent ~5% of the non-refractory (NR OA signal. Our results strongly imply that all OA types should be considered

  18. Integrated analysis of seaweed components during seasonal fluctuation by data mining across heterogeneous chemical measurements with network visualization.

    Science.gov (United States)

    Ito, Kengo; Sakata, Kenji; Date, Yasuhiro; Kikuchi, Jun

    2014-01-21

    Biological information is intricately intertwined with several factors. Therefore, comprehensive analytical methods such as integrated data analysis, combining several data measurements, are required. In this study, we describe a method of data preprocessing that can perform comprehensively integrated analysis based on a variety of multimeasurement of organic and inorganic chemical data from Sargassum fusiforme and explore the concealed biological information by statistical analyses with integrated data. Chemical components including polar and semipolar metabolites, minerals, major elemental and isotopic ratio, and thermal decompositional data were measured as environmentally responsive biological data in the seasonal variation. The obtained spectral data of complex chemical components were preprocessed to isolate pure peaks by removing noise and separating overlapping signals using the multivariate curve resolution alternating least-squares method before integrated analyses. By the input of these preprocessed multimeasurement chemical data, principal component analysis and self-organizing maps of integrated data showed changes in the chemical compositions during the mature stage and identified trends in seasonal variation. Correlation network analysis revealed multiple relationships between organic and inorganic components. Moreover, in terms of the relationship between metal group and metabolites, the results of structural equation modeling suggest that the structure of alginic acid changes during the growth of S. fusiforme, which affects its metal binding ability. This integrated analytical approach using a variety of chemical data can be developed for practical applications to obtain new biochemical knowledge including genetic and environmental information.

  19. Use of near infrared spectroscopy to measure the chemical and mechanical properties of solid wood

    Science.gov (United States)

    Stephen S. Kelley; Timothy G. Rials; Rebecca Snell; Leslie H. Groom; Amie Sluiter

    2004-01-01

    Near infrared (NIR) spectroscopy (500 nm-2400 nm), coupled with multivariate analytic (MVA) statistical techniques, have been used to predict the chemical and mechanical properties of solid loblolly pine wood. The samples were selected from different radial locations and heights of three loblolly pine trees grown in Arkansas. The chemical composition and mechanical...

  20. Use of near infared spectroscopy to measure the chemical and mechanical properties of solid wood

    Science.gov (United States)

    Stephen S. Kelley; Timothy G. Rials; Rebecca Snell; Leslie H. Groom; Amie Sluiter

    2004-01-01

    Near infrared (NIR) spectroscopy (500 nm-2400 nm), coupled with multivariate analytic (MVA) statistical techniques, have been used to predict the chemical and mechanical properties of solid loblolly pine wood. The samples were selected from different radial locations and heights of three loblolly pine trees grown in Arkansas. The chemical composition and mechanical...

  1. Chemical Abundance Measurements of Ultra-Faint Dwarf Galaxies Discovered by the Dark Energy Survey

    Science.gov (United States)

    Nagasawa, Daniel; Marshall, Jennifer L.; Simon, Joshua D.; Hansen, Terese; Li, Ting; Bernstein, Rebecca; Balbinot, Eduardo; Drlica-Wagner, Alex; Pace, Andrew; Strigari, Louis; Pellegrino, Craig; DePoy, Darren L.; Suntzeff, Nicholas; Bechtol, Keith; Dark Energy Suvey

    2018-01-01

    We present chemical abundance analysis results derived from high-resolution spectroscopy of ultra-faint dwarfs discovered by the Dark Energy Survey. Ultra-faint dwarf galaxies preserve a fossil record of the chemical abundance patterns imprinted by the first stars in the Universe. High-resolution spectroscopic observations of member stars in several recently discovered Milky Way satellites reveal a range of abundance patterns among ultra-faint dwarfs suggesting that star formation processes in the early Universe were quite diverse. The chemical content provides a glimpse not only of the varied nucleosynthetic processes and chemical history of the dwarfs themselves, but also the environment in which they were formed. We present the chemical abundance analysis of these objects and discuss possible explanations for the observed abundance patterns.

  2. Synthetic Biology Guides Biofuel Production

    Directory of Open Access Journals (Sweden)

    Michael R. Connor

    2010-01-01

    Full Text Available The advancement of microbial processes for the production of renewable liquid fuels has increased with concerns about the current fuel economy. The development of advanced biofuels in particular has risen to address some of the shortcomings of ethanol. These advanced fuels have chemical properties similar to petroleum-based liquid fuels, thus removing the need for engine modification or infrastructure redesign. While the productivity and titers of each of these processes remains to be improved, progress in synthetic biology has provided tools to guide the engineering of these processes through present and future challenges.

  3. Synthetic carbonaceous fuels and feedstocks

    Science.gov (United States)

    Steinberg, Meyer

    1980-01-01

    This invention relates to the use of a three compartment electrolytic cell in the production of synthetic carbonaceous fuels and chemical feedstocks such as gasoline, methane and methanol by electrolyzing an aqueous sodium carbonate/bicarbonate solution, obtained from scrubbing atmospheric carbon dioxide with an aqueous sodium hydroxide solution, whereby the hydrogen generated at the cathode and the carbon dioxide liberated in the center compartment are combined thermocatalytically into methanol and gasoline blends. The oxygen generated at the anode is preferably vented into the atmosphere, and the regenerated sodium hydroxide produced at the cathode is reused for scrubbing the CO.sub.2 from the atmosphere.

  4. Synthetic Biology Guides Biofuel Production

    Science.gov (United States)

    Connor, Michael R.; Atsumi, Shota

    2010-01-01

    The advancement of microbial processes for the production of renewable liquid fuels has increased with concerns about the current fuel economy. The development of advanced biofuels in particular has risen to address some of the shortcomings of ethanol. These advanced fuels have chemical properties similar to petroleum-based liquid fuels, thus removing the need for engine modification or infrastructure redesign. While the productivity and titers of each of these processes remains to be improved, progress in synthetic biology has provided tools to guide the engineering of these processes through present and future challenges. PMID:20827393

  5. Synthetic analogs of bacterial quorum sensors

    Energy Technology Data Exchange (ETDEWEB)

    Iyer, Rashi [Los Alamos, NM; Ganguly, Kumkum [Los Alamos, NM; Silks, Louis A [Los Alamos, NM

    2011-12-06

    Bacterial quorum-sensing molecule analogs having the following structures: ##STR00001## and methods of reducing bacterial pathogenicity, comprising providing a biological system comprising pathogenic bacteria which produce natural quorum-sensing molecule; providing a synthetic bacterial quorum-sensing molecule having the above structures and introducing the synthetic quorum-sensing molecule into the biological system comprising pathogenic bacteria. Further is provided a method of targeted delivery of an antibiotic, comprising providing a synthetic quorum-sensing molecule; chemically linking the synthetic quorum-sensing molecule to an antibiotic to produce a quorum-sensing molecule-antibiotic conjugate; and introducing the conjugate into a biological system comprising pathogenic bacteria susceptible to the antibiotic.

  6. Synthetic analogs of bacterial quorum sensors

    Energy Technology Data Exchange (ETDEWEB)

    Iyer, Rashi S.; Ganguly, Kumkum; Silks, Louis A.

    2013-01-08

    Bacterial quorum-sensing molecule analogs having the following structures: ##STR00001## and methods of reducing bacterial pathogenicity, comprising providing a biological system comprising pathogenic bacteria which produce natural quorum-sensing molecule; providing a synthetic bacterial quorum-sensing molecule having the above structures and introducing the synthetic quorum-sensing molecule into the biological system comprising pathogenic bacteria. Further is provided a method of targeted delivery of an antibiotic, comprising providing a synthetic quorum-sensing molecule; chemically linking the synthetic quorum-sensing molecule to an antibiotic to produce a quorum-sensing molecule-antibiotic conjugate; and introducing the conjugate into a biological system comprising pathogenic bacteria susceptible to the antibiotic.

  7. Prospects for applying synthetic biology to toxicology

    DEFF Research Database (Denmark)

    Behrendorff, James Bruce Yarnton H; Gillam, Elizabeth M.J.

    2017-01-01

    The 30 years since the inception of Chemical Research in Toxicology, game-changing advances in chemical and molecular biology, the fundamental disciplines underpinning molecular toxicology, have been made. While these have led to important advances in the study of mechanisms by which chemicals...... damage cells and systems, there has been less focus on applying these advances to prediction, detection, and mitigation of toxicity. Over the last ∼15 years, synthetic biology, the repurposing of biological "parts" in systems engineered for useful ends, has been explored in other areas of the biomedical...... and life sciences, for such applications as detecting metabolites, drug discovery and delivery, investigating disease mechanisms, improving medical treatment, and producing useful chemicals. These examples provide models for the application of synthetic biology to toxicology, which, for the most part, has...

  8. Comparison of natural and synthetic diamond X-ray detectors.

    Science.gov (United States)

    Lansley, S P; Betzel, G T; Metcalfe, P; Reinisch, L; Meyer, J

    2010-12-01

    Diamond detectors are particularly well suited for dosimetry applications in radiotherapy for reasons including near-tissue equivalence and high-spatial resolution resulting from small sensitive volumes. However, these detectors have not become commonplace due to high cost and poor availability arising from the need for high-quality diamond. We have fabricated relatively cheap detectors from commercially-available synthetic diamond fabricated using chemical vapour deposition. Here, we present a comparison of one of these detectors with the only commercially-available diamond-based detector (which uses a natural diamond crystal). Parameters such as the energy dependence and linearity of charge with dose were investigated at orthovoltage energies (50-250 kV), and dose-rate dependence of charge at linear accelerator energy (6 MV). The energy dependence of a synthetic diamond detector was similar to that of the natural diamond detector, albeit with slightly less variation across the energy range. Both detectors displayed a linear response with dose (at 100 kV) over the limited dose range used. The sensitivity of the synthetic diamond detector was 302 nC/Gy, compared to 294 nC/Gy measured for the natural diamond detector; however, this was obtained with a bias of 246.50 V compared to a bias of 61.75 V used for the natural diamond detector. The natural diamond detector exhibited a greater dependency on dose-rate than the synthetic diamond detector. Overall, the synthetic diamond detector performed well in comparison to the natural diamond detector.

  9. Changes of brain metabolite concentrations during maturation in different brain regions measured by chemical shift imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bueltmann, Eva; Lanfermann, Heinrich [Hannover Medical School, Institute of Diagnostic and Interventional Neuroradiology, Hannover (Germany); Naegele, Thomas [University of Tuebingen, Department of Diagnostic and Interventional Neuroradiology, Radiological University Hospital, Tuebingen (Germany); Klose, Uwe [University of Tuebingen, Section of Experimental MR of the CNS, Department of Neuroradiology, Radiological University Hospital, Tuebingen (Germany)

    2017-01-15

    We examined the effect of maturation on the regional distribution of brain metabolite concentrations using multivoxel chemical shift imaging. From our pool of pediatric MRI examinations, we retrospectively selected patients showing a normal cerebral MRI scan or no pathologic signal abnormalities at the level of the two-dimensional 1H MRS-CSI sequence and an age-appropriate global neurological development, except for focal neurological deficits. Seventy-one patients (4.5 months-20 years) were identified. Using LC Model, spectra were evaluated from voxels in the white matter, caudate head, and corpus callosum. The concentration of total N-acetylaspartate increased in all regions during infancy and childhood except in the right caudate head where it remained constant. The concentration of total creatine decreased in the caudate nucleus and splenium and minimally in the frontal white matter and genu. It remained largely constant in the parietal white matter. The concentration of choline-containing compounds had the tendency to decrease in all regions except in the parietal white matter where it remained constant. The concentration of myoinositol decreased slightly in the splenium and right frontal white matter, remained constant on the left side and in the caudate nucleus, and rose slightly in the parietal white matter and genu. CSI determined metabolite concentrations in multiple cerebral regions during routine MRI. The obtained data will be helpful in future pediatric CSI measurements deciding whether the ratios of the main metabolites are within the range of normal values or have to be considered as probably pathologic. (orig.)

  10. Changes of brain metabolite concentrations during maturation in different brain regions measured by chemical shift imaging

    International Nuclear Information System (INIS)

    Bueltmann, Eva; Lanfermann, Heinrich; Naegele, Thomas; Klose, Uwe

    2017-01-01

    We examined the effect of maturation on the regional distribution of brain metabolite concentrations using multivoxel chemical shift imaging. From our pool of pediatric MRI examinations, we retrospectively selected patients showing a normal cerebral MRI scan or no pathologic signal abnormalities at the level of the two-dimensional 1H MRS-CSI sequence and an age-appropriate global neurological development, except for focal neurological deficits. Seventy-one patients (4.5 months-20 years) were identified. Using LC Model, spectra were evaluated from voxels in the white matter, caudate head, and corpus callosum. The concentration of total N-acetylaspartate increased in all regions during infancy and childhood except in the right caudate head where it remained constant. The concentration of total creatine decreased in the caudate nucleus and splenium and minimally in the frontal white matter and genu. It remained largely constant in the parietal white matter. The concentration of choline-containing compounds had the tendency to decrease in all regions except in the parietal white matter where it remained constant. The concentration of myoinositol decreased slightly in the splenium and right frontal white matter, remained constant on the left side and in the caudate nucleus, and rose slightly in the parietal white matter and genu. CSI determined metabolite concentrations in multiple cerebral regions during routine MRI. The obtained data will be helpful in future pediatric CSI measurements deciding whether the ratios of the main metabolites are within the range of normal values or have to be considered as probably pathologic. (orig.)

  11. Mixed butanols addition to gasoline surrogates: Shock tube ignition delay time measurements and chemical kinetic modeling

    KAUST Repository

    AlRamadan, Abdullah S.

    2015-10-01

    The demand for fuels with high anti-knock quality has historically been rising, and will continue to increase with the development of downsized and turbocharged spark-ignition engines. Butanol isomers, such as 2-butanol and tert-butanol, have high octane ratings (RON of 105 and 107, respectively), and thus mixed butanols (68.8% by volume of 2-butanol and 31.2% by volume of tert-butanol) can be added to the conventional petroleum-derived gasoline fuels to improve octane performance. In the present work, the effect of mixed butanols addition to gasoline surrogates has been investigated in a high-pressure shock tube facility. The ignition delay times of mixed butanols stoichiometric mixtures were measured at 20 and 40bar over a temperature range of 800-1200K. Next, 10vol% and 20vol% of mixed butanols (MB) were blended with two different toluene/n-heptane/iso-octane (TPRF) fuel blends having octane ratings of RON 90/MON 81.7 and RON 84.6/MON 79.3. These MB/TPRF mixtures were investigated in the shock tube conditions similar to those mentioned above. A chemical kinetic model was developed to simulate the low- and high-temperature oxidation of mixed butanols and MB/TPRF blends. The proposed model is in good agreement with the experimental data with some deviations at low temperatures. The effect of mixed butanols addition to TPRFs is marginal when examining the ignition delay times at high temperatures. However, when extended to lower temperatures (T < 850K), the model shows that the mixed butanols addition to TPRFs causes the ignition delay times to increase and hence behaves like an octane booster at engine-like conditions. © 2015 The Combustion Institute.

  12. Quantum synthetic aperture radar

    Science.gov (United States)

    Lanzagorta, Marco; Jitrik, Oliverio; Uhlmann, Jeffrey; Venegas-Andraca, Salvador E.

    2017-05-01

    Synthetic aperture radar (SAR) uses sensor motion to generate finer spatial resolution of a given target area. In this paper we explore the theoretical potential of quantum synthetic aperture quantum radar (QSAR). We provide theoretical analysis and simulation results which suggest that QSAR can provide improved detection performance over classical SAR in the high-noise low-brightness regime.

  13. 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.

  14. Synthetic drugs with anti-ageing effects.

    Science.gov (United States)

    Kapoor, Vijay K; Dureja, Janhvi; Chadha, Renu

    2009-09-01

    Although ageing is a natural wear and tear phenomenon, it can at least be postponed or prevented by certain approaches. Some chemicals that are present in the diet or in dietary supplements have been documented to have anti-ageing effects. Recently, a number of synthetic drugs used for other therapeutic indications have been shown to have anti-ageing potential.

  15. Immunization with a synthetic robustoxin derivative lacking ...

    Indian Academy of Sciences (India)

    Prakash

    has 42 amino acid residues and four disulphide bridges. If these bridges are broken, the resulting polypeptide is non- toxic. Robustoxin was chemically synthesized with all of its eight cysteine residues protected with acetamidomethyl groups in ...... G L, Moss B, Miller L H and Berzofsky J A 1987 Construction of synthetic ...

  16. SUPPLEMENTARY INFORMATION Green synthetic route for ...

    Indian Academy of Sciences (India)

    GDY13

    Green synthetic route for perfumery compound (2-methoxyethyl) benzene using. Li/MgO catalyst. POOJA R TAMBE and ... A mixture containing fuel and oxidizer was taken in a silica crucible and heated to form highly .... Fogler H 1995 Elements of Chemical Reaction Engineering 2nd edn. Prentice-Hall,. New Delhi, India. (3).

  17. Synthetic biology advances for pharmaceutical production

    Science.gov (United States)

    Breitling, Rainer; Takano, Eriko

    2015-01-01

    Synthetic biology enables a new generation of microbial engineering for the biotechnological production of pharmaceuticals and other high-value chemicals. This review presents an overview of recent advances in the field, describing new computational and experimental tools for the discovery, optimization and production of bioactive molecules, and outlining progress towards the application of these tools to pharmaceutical production systems. PMID:25744872

  18. Compounding in synthetic aperture imaging

    DEFF Research Database (Denmark)

    Hansen, J. M.; Jensen, J. A.

    2012-01-01

    from multiple spherical emissions to synthesize multiple transmit and receive apertures, corresponding to imaging the tissue from multiple directions. The many images are added incoherently, to produce a single compound image. Using a 192-element, 3.5-MHz, λ-pitch transducer, it is demonstrated from...... tissue-phantom measurements that the speckle is reduced and the contrast resolution improved when applying synthetic aperture compound imaging. At a depth of 4 cm, the size of the synthesized apertures is optimized for lesion detection based on the speckle information density. This is a performance...... measure for tissue contrast resolution which quantifies the tradeoff between resolution loss and speckle reduction. The speckle information density is improved by 25% when comparing synthetic aperture compounding to a similar setup for compounding using dynamic receive focusing. The cystic resolution...

  19. Low-frequency electromagnetic measurements as a zero-time discriminant of nuclear and chemical explosions - OSI research final report

    International Nuclear Information System (INIS)

    Sweeney, J.J.

    1996-12-01

    This is the final report on a series of investigations of low frequency (1-40 Hz) electromagnetic signals produced by above ground and underground chemical explosions and their use for confidence building under the Comprehensive Test-Ban Treaty. I conclude that low frequency electromagnetic measurements can be a very powerful tool for zero-time discrimination of chemical and nuclear explosions for yields of 1 Kt or greater, provided that sensors can be placed within 1-2 km of the suspected detonation point in a tamper-proof, low noise environment. The report includes descriptions and analyses of low frequency electromagnetic measurements associated with chemical explosions carried out in a variety of settings (shallow borehole, open pit mining, underground mining). I examine cavity pressure data from the Non-Proliferation Experiment (underground chemical explosion) and present the hypothesis that electromagnetic signals produced by underground chemical explosions could be produced during rock fracturing. I also review low frequency electromagnetic data from underground nuclear explosions acquired by Lawrence Livermore National Laboratory during the late 1980s. (author)

  20. Low-frequency electromagnetic measurements as a zero-time discriminant of nuclear and chemical explosions -- OSI research final report

    Energy Technology Data Exchange (ETDEWEB)

    Sweeney, J. J.

    1996-12-01

    This is the final report on a series of investigations of low frequency (1-40 Hz) electromagnetic signals produced by above ground and underground chemical explosions and their use for confidence building under the Comprehensive Test-Ban Treaty. I conclude that low frequency electromagnetic measurements can be a very powerful tool for zero-time discrimination of chemical and nuclear explosions for yields of 1 Kt or greater, provided that sensors can be placed within 1-2 km of the suspected detonation point in a tamper-proof, low noise environment. The report includes descriptions and analyses of low frequency electromagnetic measurements associated with chemical explosions carried out in a variety of settings (shallow borehole, open pit mining, underground mining). I examine cavity pressure data from the Non-Proliferation Experiment (underground chemical explosion) and present the hypothesis that electromagnetic signals produced by underground chemical explosions could be produced during rock fracturing. I also review low frequency electromagnetic data from underground nuclear explosions acquired by Lawrence Livermore National Laboratory during the late 1980s.

  1. 129Xe chemical shift in human blood and pulmonary blood oxygenation measurement in humans using hyperpolarized 129Xe NMR

    Science.gov (United States)

    Norquay, Graham; Leung, General; Stewart, Neil J.; Wolber, Jan

    2016-01-01

    Purpose To evaluate the dependency of the 129Xe‐red blood cell (RBC) chemical shift on blood oxygenation, and to use this relation for noninvasive measurement of pulmonary blood oxygenation in vivo with hyperpolarized 129Xe NMR. Methods Hyperpolarized 129Xe was equilibrated with blood samples of varying oxygenation in vitro, and NMR was performed at 1.5 T and 3 T. Dynamic in vivo NMR during breath hold apnea was performed at 3 T on two healthy volunteers following inhalation of hyperpolarized 129Xe. Results The 129Xe chemical shift in RBCs was found to increase nonlinearly with blood oxygenation at 1.5 T and 3 T. During breath hold apnea, the 129Xe chemical shift in RBCs exhibited a periodic time modulation and showed a net decrease in chemical shift of ∼1 ppm over a 35 s breath hold, corresponding to a decrease of 7–10 % in RBC oxygenation. The 129Xe‐RBC signal amplitude showed a modulation with the same frequency as the 129Xe‐RBC chemical shift. Conclusion The feasibility of using the 129Xe‐RBC chemical shift to measure pulmonary blood oxygenation in vivo has been demonstrated. Correlation between 129Xe‐RBC signal and 129Xe‐RBC chemical shift modulations in the lung warrants further investigation, with the aim to better quantify temporal blood oxygenation changes in the cardiopulmonary vascular circuit. Magn Reson Med 77:1399–1408, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. PMID:27062652

  2. Living GenoChemetics by hyphenating synthetic biology and synthetic chemistry in vivo.

    Science.gov (United States)

    Sharma, Sunil V; Tong, Xiaoxue; Pubill-Ulldemolins, Cristina; Cartmell, Christopher; Bogosyan, Emma J A; Rackham, Emma J; Marelli, Enrico; Hamed, Refaat B; Goss, Rebecca J M

    2017-08-09

    Marrying synthetic biology with synthetic chemistry provides a powerful approach toward natural product diversification, combining the best of both worlds: expediency and synthetic capability of biogenic pathways and chemical diversity enabled by organic synthesis. Biosynthetic pathway engineering can be employed to insert a chemically orthogonal tag into a complex natural scaffold affording the possibility of site-selective modification without employing protecting group strategies. Here we show that, by installing a sufficiently reactive handle (e.g., a C-Br bond) and developing compatible mild aqueous chemistries, synchronous biosynthesis of the tagged metabolite and its subsequent chemical modification in living culture can be achieved. This approach can potentially enable many new applications: for example, assay of directed evolution of enzymes catalyzing halo-metabolite biosynthesis in living cells or generating and following the fate of tagged metabolites and biomolecules in living systems. We report synthetic biological access to new-to-nature bromo-metabolites and the concomitant biorthogonal cross-coupling of halo-metabolites in living cultures.Coupling synthetic biology and chemical reactions in cells is a challenging task. The authors engineer bacteria capable of generating bromo-metabolites, develop a mild Suzuki-Miyaura cross-coupling reaction compatible with cell growth and carry out the cross-coupling chemistry in live cell cultures.

  3. 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)

  4. Sorption of a diverse set of organic chemical vapors onto XAD-2 resin: Measurement, prediction and implications for air sampling

    Science.gov (United States)

    Hayward, Stephen J.; Lei, Ying D.; Wania, Frank

    2011-01-01

    The wide-spread use of styrene-divinylbenzene-copolymeric resin (XAD-2) in air sampling necessitates a quantitative understanding of its sorption characteristics for organic chemicals. Inverse Gas Chromatography (IGC) was used to measure the sorption of a diverse set of 52 organic chemicals to XAD-2 at temperatures between 40 °C and 100 °C and at relative humidities between 0 and 87%. Even though relative humidity has been shown to influence sorption to other sorbents, it did not significantly influence most chemicals' sorption to XAD-2, indicating that water does not form a strong physical barrier to sorption on XAD-2 at high relative humidity. The resin-air partition coefficients ( KXAD) determined by IGC and the enthalpies of sorption derived from them were regressed against solute descriptors to derive poly-parameter Linear Free Energy Relationships (ppLFERs) which allow the estimation of KXAD for chemicals which are not sufficiently volatile to be amenable to IGC and for temperatures outside the experimental range. KXAD values at 20 °C estimated for a set of 296 chemicals for which solute descriptors are available, including polychlorinated biphenyls, polycyclic aromatic hydrocarbons, and pesticides, indicate that for many of the substances commonly found in the atmosphere sorption is higher to XAD-2 than to poly-urethane foam, another popular air sampling sorbent.

  5. Synthetic Biological Membrane (SBM)

    Data.gov (United States)

    National Aeronautics and Space Administration — The ultimate goal of the Synthetic Biological Membrane project is to develop a new type of membrane that will enable the wastewater treatment system required on...

  6. Control of Rhizoctonia solani in potato by biological, chemical and integrated measures

    NARCIS (Netherlands)

    Jager, G.; Velvis, H.; Lamers, J.G.; Mulder, A.; Roosjen, J.

    1991-01-01

    The effects of biological, chemical and integrated control on the formation of selerotia ofRhizoctonia solani on new potato tubers were studied in experimental fields. Sprouts of seed tubers, sprouted in daylight, were inoculated withVerticillium biguttatum, an ecologically obligate mycoparasite

  7. Performance of the In Situ Microcosm Technique for Measuring the Degradation of Organic Chemicals in Aquifers

    DEFF Research Database (Denmark)

    Nielsen, Per H.; Christensen, Thomas Højlund; Albrechtsen, Hans-Jørgen

    1996-01-01

    chemicals in polluted and pristine aquifers representing different redox environments. The ISM technique has great potential for providing field-relevant degradation potentials and rate constants, but care must be taken in using the equipment and interpreting the results. This paper provides details...

  8. Synthetic greenhouse gases under control

    International Nuclear Information System (INIS)

    Horisberger, B.; Karlaganis, G.

    2003-01-01

    This article discusses new Swiss regulations on the use of synthetic materials that posses a considerable greenhouse-warming potential. Synthetic materials such as hydro-chlorofluorocarbons HCFCs, perfluoride-hydrocarbons and sulphur hexafluoride have, in recent years, replaced chlorofluorocarbons CFCs, which were banned on account of their ozone depletion characteristics. The use of these persistent substances is now being limited to applications where more environment-friendly alternatives are not available. The measures decreed in the legislation, which include a general ban on HCFCs as of 2004 and a ban on the export of installations and equipment that use ozone-depleting refrigerants are described. Details on the legislation's effects on the Swiss refrigeration industry are listed and discussed

  9. Hybridization with synthetic oligonucleotides

    Energy Technology Data Exchange (ETDEWEB)

    Szostak, J.W.; Stiles, J.I.; Tye, B.K.; Sherman, F.; Wu, R.

    1978-01-01

    Procedures are described for the use of synthetic oligonucleotides for Southern blot experiments and gene bank screening, and the effect of various mismatches on the efficiency of hybridization is demonstrated. The following topics are discussed: sensitivity vs. specificity, hybridization of a 12-mer to the lambda endolysin gene; hybridization of oligonucleotide probes to the E. coli lac operator; hybridization of synthetic probes to the CYC1 gene of yeast; and cloning eucaryotic genes. (HLW)

  10. Mammalian Synthetic Biology

    OpenAIRE

    Martella, Andrea; Pollard, Steven M; Dai, Junbiao; Cai, Yizhi

    2016-01-01

    The enabling technologies of synthetic biology are opening up new opportunities for engineering and enhancement of mammalian cells. This will stimulate diverse applications in many life science sectors such as regenerative medicine, development of biosensing cell lines, therapeutic protein production, and generation of new synthetic genetic regulatory circuits. Harnessing the full potential of these new engineering-based approaches requires the design and assembly of large DNA constructs-pote...

  11. Guidelines for measuring the physical, chemical, and biological condition of wilderness ecosystems

    Science.gov (United States)

    Douglas G Fox; J. Christopher Bernabo; Betsy Hood

    1987-01-01

    Guidelines include a large number of specific measures to characterize the existing condition of wilderness resources. Measures involve the atmospheric environment, water chemistry and biology, geology and soils, and flora. Where possible, measures are coordinated with existing long-term monitoring programs. Application of the measures will allow more effective...

  12. Synthetic Fourier transform light scattering.

    Science.gov (United States)

    Lee, Kyeoreh; Kim, Hyeon-Don; Kim, Kyoohyun; Kim, Youngchan; Hillman, Timothy R; Min, Bumki; Park, Yongkeun

    2013-09-23

    We present synthetic Fourier transform light scattering, a method for measuring extended angle-resolved light scattering (ARLS) from individual microscopic samples. By measuring the light fields scattered from the sample plane and numerically synthesizing them in Fourier space, the angle range of the ARLS patterns is extended up to twice the numerical aperture of the imaging system with unprecedented sensitivity and precision. Extended ARLS patterns of individual microscopic polystyrene beads, healthy human red blood cells (RBCs), and Plasmodium falciparum-parasitized RBCs are presented.

  13. Wettability determination by contact angle measurements: hvbB coal-water system with injection of synthetic flue gas and CO2.

    Science.gov (United States)

    Shojai Kaveh, Narjes; Rudolph, E Susanne J; Wolf, Karl-Heinz A A; Ashrafizadeh, Seyed Nezameddin

    2011-12-01

    Geological sequestration of pure carbon dioxide (CO(2)) in coal is one of the methods to sequester CO(2). In addition, injection of CO(2) or flue gas into coal enhances coal bed methane production (ECBM). The success of this combined process depends strongly on the wetting behavior of the coal, which is function of coal rank, ash content, heterogeneity of the coal surface, pressure, temperature and composition of the gas. The wetting behavior can be evaluated from the contact angle of a gas bubble, CO(2) or flue gas, on a coal surface. In this study, contact angles of a synthetic flue gas, i.e. a 80/20 (mol%) N(2)/CO(2) mixture, and pure CO(2) on a Warndt Luisenthal (WL) coal have been determined using a modified pendant drop cell in a pressure range from atmospheric to 16 MPa and a constant temperature of 318 K. It was found that the contact angles of flue gas on WL coal were generally smaller than those of CO(2). The contact angle of CO(2) changes from water-wet to gas-wet by increasing pressure above 8.5 MPa while the one for the flue gas changes from water-wet to intermediate-wet by increasing pressure above 10 MPa. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. An overview of human biomonitoring of environmental chemicals in the Canadian Health Measures Survey: 2007-2019.

    Science.gov (United States)

    Haines, Douglas A; Saravanabhavan, Gurusankar; Werry, Kate; Khoury, Cheryl

    2017-03-01

    Human biomonitoring (HBM) is used to indicate and quantify exposure by measuring environmental chemicals, their metabolites or reaction products in biological specimens. The biomonitoring component of the Canadian Health Measures Survey (CHMS) is the most comprehensive initiative providing general population HBM data in Canada. The CHMS is an ongoing cross-sectional direct measures survey implemented in 2-year cycles. It provides nationally-representative data on health, nutritional status, environmental exposures, and related risks and protective characteristics. The survey follows a robust planning, design and sampling protocol as well as a comprehensive quality assurance and quality control regime implemented for all aspect of the survey to ensure the validity of the HBM results. HBM blood and urine data are available for CHMS cycles 1 (2007-2009), 2 (2009-2011) and 3 (2012-2013). Field collection has been completed for cycle 4 (2014-2015), with cycle 5 (2016-2017) in progress and cycle 6 planning (2018-2019) being finalized. Biomonitoring results for 279 chemicals are expected over the six cycles of the CHMS (220 in individual blood, urine or hair samples, and 59 in pooled serum samples). The chemicals include metals and trace elements, polychlorinated biphenyls (PCBs), organochlorines, flame retardants, perfluoroalkyl substances, volatile organic compounds (VOCs) and metabolites, environmental phenols, triclocarban, acrylamide, pesticides (e.g., triazines, carbamates, organophosphates, phenoxy, pyrethroids) and/or their metabolites, chlorophenols, polycyclic aromatic hydrocarbon (PAH) metabolites, phthalates and alternate plasticizer metabolites, and tobacco biomarkers. Approximately one half of the chemicals measured in individual blood and urine samples over the first three cycles were detected in more than 60% of samples. CHMS biomonitoring data have been used to establish baseline HBM concentrations in Canadians; inform public health, regulatory risk

  15. Measurements of physical-chemical characteristics of dairy plant waste waters

    OpenAIRE

    Stefanović Dragoslav; Vojnović-Miloradov Mirjana; Lemić Jovan; Kurajica Milorad; Kovačević Dragana

    2008-01-01

    Characteristics of waste waters of the dairy industry are specific and differ essentially from waste waters of other branches of the food industry. The complexity of production in dairy plants with several units for different products render the problem of waste waters of this industry particularly complex. Waste waters of the AD Imlek dairy plant were sampled and their chemical characteristics were determined at different seasons of the year and at different times of the day in the years 200...

  16. Synthetic approaches to uniform polymers.

    Science.gov (United States)

    Ali, Monzur; Brocchini, Steve

    2006-12-30

    Uniform polymers are characterised by a narrow molecular weight distribution (MWD). Uniformity is also defined by chemical structure in respect of (1) monomer orientation, sequence and stereo-regularity, (2) polymer shape and morphology and (3) chemical functionality. The function of natural polymers such as polypeptides and polynucleotides is related to their conformational structure (e.g. folded tertiary structure). This is only possible because of their high degree of uniformity. While completely uniform synthetic polymers are rare, polymers with broad structure and MWD are widely used in medicine and the biomedical sciences. They are integral components in final dosage forms, drug delivery systems (DDS) and in implantable devices. Increasingly uniform polymers are being used to develop more complex medicines (e.g. delivery of biopharmaceuticals, enhanced formulations or DDS's for existing actives). In addition to the function imparted by any new polymer it will be required to meet stringent specifications in terms of cost containment, scalability, biocompatibility and performance. Synthetic polymers with therapeutic activity are also being developed to exploit their polyvalent properties, which is not possible with low molecular weight molecules. There is need to utilise uniform polymers for applications where the polymer may interact with the systemic circulation, tissues or cellular environment. There are also potential applications (e.g. stimuli responsive coatings) where uniform polymers may be used for their more defined property profile. While it is not yet practical to prepare synthetic polymers to the same high degree of uniformity as proteins, nature also effectively utilises many polymers with lower degrees of uniformity (e.g. polysaccharides, poly(amino acids), polyhydroxyalkanoates). In recent years it has become possible to prepare with practical experimental protocols sufficient quantities of polymers that display many aspects of uniformity. This

  17. A study on diffusion and migration processes of ions in sedimentary rock matrix: Measurements and evaluations of physical and chemical properties of Horonobe Mudstone

    International Nuclear Information System (INIS)

    Sato, Haruo

    2003-06-01

    The physical and chemical properties of Horonobe mudstone (HDB-1 borehole) were measured and evaluated as a function of depth from ground surface (8 points). Micropore structural observations by SEM, constituent element analyses by EDS, mode analyses and the measurements of swelling properties and exchangeable cations (EC) in addition to the measurements of porosity, dry density, solid density, pore-size distribution and the specific surface area of pores were measured as the physical and chemical properties. It is considered that clearly physical gap exists between mudstone samples 4 (depth: 288.33 m) and 5 (depth: 370.95 m), and that geological formations with different properties neighbor between those depths, judging synthetically the results of measurements by water saturation method and Hg porosimetry, the results of the measurements of swelling properties and the results of micropore structural observations by SEM. In the results of the measurements of EC, the sum total of EC was in the range of about 10-35 meq/100 g in Koetoi formation, and showed a tendency to increase with an increase of depth. On the other hand, it was in the range of about 30-40 meq/100 g in Wakkanai formation, and were approximately constant. This indicates that cation exchangeability is potentially high in Wakkanai formation. The results of mode analyses indicated that rock is diatomaceous earth in whole Koetoi formation and in the upper part of Wakkanai formation (mudstone samples 1-5: ∼370.95 m), and is tuffaceous mudstone in area deeper than there. It was found that diatomaceous earth is composed of mainly some kinds of diatom fossils. Moreover, from the results of SEM observations and EDS analyses, many diatom fossils were found in Koetoi formation and in the upper part of Wakkanai formation (mudstone samples 1-5: ∼370.95 m), but the number of diatom fossil decreased in mudstone sample 6 (depth: 453.28 m), and diatom fossils were few found in mudstone sample 7 (depth:528.77 m

  18. In situ chemical composition measurement of individual cloud residue particles at a mountain site, southern China

    Science.gov (United States)

    Lin, Qinhao; Zhang, Guohua; Peng, Long; Bi, Xinhui; Wang, Xinming; Brechtel, Fred J.; Li, Mei; Chen, Duohong; Peng, Ping'an; Sheng, Guoying; Zhou, Zhen

    2017-07-01

    To investigate how atmospheric aerosol particles interact with chemical composition of cloud droplets, a ground-based counterflow virtual impactor (GCVI) coupled with a real-time single-particle aerosol mass spectrometer (SPAMS) was used to assess the chemical composition and mixing state of individual cloud residue particles in the Nanling Mountains (1690 m a. s. l. ), southern China, in January 2016. The cloud residues were classified into nine particle types: aged elemental carbon (EC), potassium-rich (K-rich), amine, dust, Pb, Fe, organic carbon (OC), sodium-rich (Na-rich) and Other. The largest fraction of the total cloud residues was the aged EC type (49.3 %), followed by the K-rich type (33.9 %). Abundant aged EC cloud residues that mixed internally with inorganic salts were found in air masses from northerly polluted areas. The number fraction (NF) of the K-rich cloud residues increased within southwesterly air masses from fire activities in Southeast Asia. When air masses changed from northerly polluted areas to southwesterly ocean and livestock areas, the amine particles increased from 0.2 to 15.1 % of the total cloud residues. The dust, Fe, Pb, Na-rich and OC particle types had a low contribution (0.5-4.1 %) to the total cloud residues. Higher fraction of nitrate (88-89 %) was found in the dust and Na-rich cloud residues relative to sulfate (41-42 %) and ammonium (15-23 %). Higher intensity of nitrate was found in the cloud residues relative to the ambient particles. Compared with nonactivated particles, nitrate intensity decreased in all cloud residues except for dust type. To our knowledge, this study is the first report on in situ observation of the chemical composition and mixing state of individual cloud residue particles in China.

  19. Enhanced anti-counterfeiting measures for additive manufacturing: coupling lanthanide nanomaterial chemical signatures with blockchain technology

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Zachary C.; Stephenson, David E.; Christ, Josef F.; Pope, Timothy R.; Arey, Bruce W.; Barrett, Christopher A.; Warner, Marvin G.

    2017-08-18

    The significant rise of additive manufacturing (AM) in recent years is in part due to the open sourced nature of the printing processes and reduced cost and capital barriers relative to traditional manufacturing. However, this democratization of manufacturing spurs an increased demand for producers and end-users to verify the authenticity and quality of individual parts. To this end, we introduce an anti-counterfeiting method composed of first embedding engineered nanomaterials into features of a 3D-printed part followed by non-destructive interrogation of these features to quantify a chemical signature profile. The part specific chemical signature data is then linked to a securitized, distributed, and time-stamped blockchain ledger entry. To demonstrate the utility of this approach, lanthanide-aspartic acid nanoscale coordination polymers (Ln3+- Asp NCs) / poly(lactic) acid (PLA) composites were formulated and transformed into a filament feedstock for fused deposition modeling (FDM) 3D printing. In the present case, a quick-response (QR) code containing the doped Ln3+-Asp NCs was printed using a dual-extruder FDM printer into pure PLA parts. The QR code provides a searchable reference to an Ethereum-based blockchain entry. The QR code physical features also serve as defined areas to probe the signatures arising from the embedded Ln3+-Asp NCs. Visible fluorescence emission with UV-excitation was quantified in terms of color using a smartphone camera and incorporated into blockchain entries. Ultimately, linking unique chemical signature data to blockchain databases is anticipated to make the costs of counterfeiting AM materials significantly more prohibitive and transactions between those in the supply chain more trustworthy.

  20. Use of molecular beams for kinetic measurements of chemical reactions on solid surfaces

    Science.gov (United States)

    Zaera, Francisco

    2017-05-01

    In this review we survey the contributions that molecular beam experiments have provided to our understanding of the dynamics and kinetics of chemical interactions of gas molecules with solid surfaces. First, we describe the experimental details of the different instrumental setups and approaches available for the study of these systems under the ultrahigh vacuum conditions and with the model planar surfaces often used in modern surface-science experiments. Next, a discussion is provided of the most important fundamental aspects of the dynamics of chemical adsorption that have been elucidated with the help of molecular beam experiments, which include the development of potential energy surfaces, the determination of the different channels for energy exchange between the incoming molecules and the surface, the identification of adsorption precursor states, the understanding of dissociative chemisorption, the determination of the contributions of corrugation, steps, and other structural details of the surface to the adsorption process, the effect to molecular steering, the identification of avenues for assisting adsorption, and the molecular details associated with the kinetics of the uptake of adsorbates as a function of coverage. We follow with a summary of the work directed at the determination of kinetic parameters and mechanistic details of surface reactions associated with catalysis, mostly those promoted by late transition metals. This discussion we initiate with an overview of what has been learned about simple bimolecular reactions such as the oxidation of CO and H2 with O2 and the reaction of CO with NO, and continue with the review of the studies of more complex systems such as the oxidation of alcohols, the conversion of organic acids, the hydrogenation and isomerization of olefins, and the oxidative activation of alkanes under conditions of short contact times. Sections 6 and 7 of this review deal with the advances made in the use of molecular beams with

  1. Wettability of porous media after exposure to synthetic gasolines

    Science.gov (United States)

    Powers, Susan E.; Tamblin, Michael E.

    1995-08-01

    The wettability of a porous medium plays a critical role in the capillary phenomena governing the migration of a nonaqueous-phase liquid (NAPL) and subsequent efforts to recover this type of pollutant source from the subsurface. Although it is usually assumed that water-wetting conditions occur, limited field evidence at NAPL sites suggests that wettability characteristics can change to intermediate or organic-phase wetting, especially for complex NAPL's containing polar or surfactant molecules. The focus of this work was an assessment of potential wettability conditions for quartz mineral surfaces after exposure to synthetic gasolines. Many of the chemicals added to gasoline to increase engine performance have polar or surfactant characteristics. It is hypothesized that these additives could sorb to the quartz, causing the surface to become less hydrophilic. Four gasoline additives were added to isooctane, the base chemical for the synthetic gasoline. Following the exposure of the mineral surfaces to the organic phases, wettability was measured by three different techniques: oil-water contact angles, air-water imbibition rates and oil-water capillary pressure curves coupled with calculation of the USBM wettability index. Results show a change to intermediate-wetting conditions for two of the additives considered. Both concentration and the molecular structure of the additives affect the extent of these alterations.

  2. Synthetic biology platform technologies for antimicrobial applications.

    Science.gov (United States)

    Braff, Dana; Shis, David; Collins, James J

    2016-10-01

    The growing prevalence of antibiotic resistance calls for new approaches in the development of antimicrobial therapeutics. Likewise, improved diagnostic measures are essential in guiding the application of targeted therapies and preventing the evolution of therapeutic resistance. Discovery platforms are also needed to form new treatment strategies and identify novel antimicrobial agents. By applying engineering principles to molecular biology, synthetic biologists have developed platforms that improve upon, supplement, and will perhaps supplant traditional broad-spectrum antibiotics. Efforts in engineering bacteriophages and synthetic probiotics demonstrate targeted antimicrobial approaches that can be fine-tuned using synthetic biology-derived principles. Further, the development of paper-based, cell-free expression systems holds promise in promoting the clinical translation of molecular biology tools for diagnostic purposes. In this review, we highlight emerging synthetic biology platform technologies that are geared toward the generation of new antimicrobial therapies, diagnostics, and discovery channels. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Repurposing ribosomes for synthetic biology.

    Science.gov (United States)

    Liu, Yi; Kim, Do Soon; Jewett, Michael C

    2017-10-01

    The translation system is the cell's factory for protein biosynthesis, stitching together hundreds to thousands of amino acids into proteins, which are required for the structure, function, and regulation of living systems. The extraordinary synthetic capability of this system, which includes the ribosome and its associated factors required for polymerization, has driven extensive efforts to harness it for societal use in areas as diverse as energy, materials, and medicine. A powerful example is recombinant protein production, which has impacted the lives of patients through the synthesis of biopharmaceuticals such as insulin. In nature, however, only limited sets of monomers are utilized, thereby resulting in limited sets of biopolymers (i.e., proteins). Expanding nature's repertoire of ribosomal monomers could yield new classes of enzymes, therapeutics, materials, and chemicals with diverse, genetically encoded chemistry. Here, we discuss recent progress towards engineering ribosomes both in vivo and in vitro. These fundamental and technical breakthroughs open doors for advanced applications in biotechnology and synthetic biology. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. DNA recognition by synthetic constructs.

    Science.gov (United States)

    Pazos, Elena; Mosquera, Jesús; Vázquez, M Eugenio; Mascareñas, José L

    2011-09-05

    The interaction of transcription factors with specific DNA sites is key for the regulation of gene expression. Despite the availability of a large body of structural data on protein-DNA complexes, we are still far from fully understanding the molecular and biophysical bases underlying such interactions. Therefore, the development of non-natural agents that can reproduce the DNA-recognition properties of natural transcription factors remains a major and challenging goal in chemical biology. In this review we summarize the basics of double-stranded DNA recognition by transcription factors, and describe recent developments in the design and preparation of synthetic DNA binders. We mainly focus on synthetic peptides that have been designed by following the DNA interaction of natural proteins, and we discuss how the tools of organic synthesis can be used to make artificial constructs equipped with functionalities that introduce additional properties to the recognition process, such as sensing and controllability. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. The Gas-Absorption/Chemical-Reaction Method for Measuring Air-Water Interfacial Area in Natural Porous Media

    Science.gov (United States)

    Lyu, Ying; Brusseau, Mark L.; El Ouni, Asma; Araujo, Juliana B.; Su, Xiaosi

    2017-11-01

    The gas-absorption/chemical-reaction (GACR) method used in chemical engineering to quantify gas-liquid interfacial area in reactor systems is adapted for the first time to measure the effective air-water interfacial area of natural porous media. Experiments were conducted with the GACR method, and two standard methods (X-ray microtomographic imaging and interfacial partitioning tracer tests) for comparison, using model glass beads and a natural sand. The results of a series of experiments conducted under identical conditions demonstrated that the GACR method exhibited excellent repeatability for measurement of interfacial area (Aia). Coefficients of variation for Aia were 3.5% for the glass beads and 11% for the sand. Extrapolated maximum interfacial areas (Am) obtained with the GACR method were statistically identical to independent measures of the specific solid surface areas of the media. For example, the Am for the glass beads is 29 (±1) cm-1, compared to 32 (±3), 30 (±2), and 31 (±2) cm-1 determined from geometric calculation, N2/BET measurement, and microtomographic measurement, respectively. This indicates that the method produced accurate measures of interfacial area. Interfacial areas determined with the GACR method were similar to those obtained with the standard methods. For example, Aias of 47 and 44 cm-1 were measured with the GACR and XMT methods, respectively, for the sand at a water saturation of 0.57. The results of the study indicate that the GACR method is a viable alternative for measuring air-water interfacial areas. The method is relatively quick, inexpensive, and requires no specialized instrumentation compared to the standard methods.

  6. Synthetic guide star generation

    Science.gov (United States)

    Payne, Stephen A [Castro Valley, CA; Page, Ralph H [Castro Valley, CA; Ebbers, Christopher A [Livermore, CA; Beach, Raymond J [Livermore, CA

    2008-06-10

    A system for assisting in observing a celestial object and providing synthetic guide star generation. A lasing system provides radiation at a frequency at or near 938 nm and radiation at a frequency at or near 1583 nm. The lasing system includes a fiber laser operating between 880 nm and 960 nm and a fiber laser operating between 1524 nm and 1650 nm. A frequency-conversion system mixes the radiation and generates light at a frequency at or near 589 nm. A system directs the light at a frequency at or near 589 nm toward the celestial object and provides synthetic guide star generation.

  7. Synthetic Aperture Sequential Beamforming

    DEFF Research Database (Denmark)

    Kortbek, Jacob; Jensen, Jørgen Arendt; Gammelmark, Kim Løkke

    2008-01-01

    A synthetic aperture focusing (SAF) technique denoted Synthetic Aperture Sequential Beamforming (SASB) suitable for 2D and 3D imaging is presented. The technique differ from prior art of SAF in the sense that SAF is performed on pre-beamformed data contrary to channel data. The objective...... is stored. The second stage applies the focused image lines from the first stage as input data. The SASB method has been investigated using simulations in Field II and by off-line processing of data acquired with a commercial scanner. The performance of SASB with a static image object is compared with DRF...

  8. Synthetic aperture interferometry: error analysis

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Amiya; Coupland, Jeremy

    2010-07-10

    Synthetic aperture interferometry (SAI) is a novel way of testing aspherics and has a potential for in-process measurement of aspherics [Appl. Opt.42, 701 (2003)].APOPAI0003-693510.1364/AO.42.000701 A method to measure steep aspherics using the SAI technique has been previously reported [Appl. Opt.47, 1705 (2008)].APOPAI0003-693510.1364/AO.47.001705 Here we investigate the computation of surface form using the SAI technique in different configurations and discuss the computational errors. A two-pass measurement strategy is proposed to reduce the computational errors, and a detailed investigation is carried out to determine the effect of alignment errors on the measurement process.

  9. Synthetic aperture interferometry: error analysis

    International Nuclear Information System (INIS)

    Biswas, Amiya; Coupland, Jeremy

    2010-01-01

    Synthetic aperture interferometry (SAI) is a novel way of testing aspherics and has a potential for in-process measurement of aspherics [Appl. Opt.42, 701 (2003)].APOPAI0003-693510.1364/AO.42.000701 A method to measure steep aspherics using the SAI technique has been previously reported [Appl. Opt.47, 1705 (2008)].APOPAI0003-693510.1364/AO.47.001705 Here we investigate the computation of surface form using the SAI technique in different configurations and discuss the computational errors. A two-pass measurement strategy is proposed to reduce the computational errors, and a detailed investigation is carried out to determine the effect of alignment errors on the measurement process.

  10. Conditioning of Si-interfaces by wet-chemical oxidation: Electronic interface properties study by surface photovoltage measurements

    Science.gov (United States)

    Angermann, Heike

    2014-09-01

    The field-modulated surface photovoltage (SPV) method, a very surface sensitive technique, was utilized to determine electronic interface properties on wet-chemically oxidized and etched silicon (Si) interfaces. The influence of preparation-induced surface micro-roughness and un-stoichiometric oxides on the resulting the surface charge, energetic distribution Dit(E), and density Dit,min of rechargeable states was studied by simultaneous, spectroscopic ellipsometry (SE) measurements on polished Si(111) and Si(100) substrates. Based on previous findings and new research, a study of conventional and newly developed wet-chemical oxidation methods was established, correlating the interactions between involved oxidizing and etching solutions and the initial substrate morphology to the final surface conditioning. It is shown, which sequences of wet-chemical oxidation and oxide removal, have to be combined in order to achieve atomically smooth, hydrogen terminated surfaces, as well as ultra-thin oxide layers with low densities of rechargeable states on flat, saw damage etched, and textured Si substrates, as commonly applied in silicon device and solar cell manufacturing. These conventional strategies for wet-chemical pre-treatment are mainly based on concentrated solutions. Therefore, special attention was put on the development of more environmentally acceptable processes, utilizing e.g. hot pure water with low contents of oxygen or hydrochloric acid, and of ozone, working at ambient temperatures. According to our results, these methods could be a high quality and low cost alternative to current approaches with liquid chemicals for the preparation of hydrophobic Si substrate surfaces and ultra-thin passivating oxide layers. As demonstrated for selected examples, the effect of optimized wet-chemical pre-treatments can be preserved during subsequent soft plasma enhanced chemical vapor depositions of Si oxides (SiOx), or amorphous materials such as Si (a-Si:H), Si nitride (a

  11. Process Analytical Technology and On-Line Spectroscopic Measurements of Chemical Meat Quality

    DEFF Research Database (Denmark)

    Sørensen, Klavs Martin

    This thesis deals with process analytical technology and how it can be implemented in the meat industry through on-line grading of chemical meat quality. The focus will be on two applications, namely the rapid quality control of fat quality and the development of a method for on-line detection...... more time than is available on a slaughter line, it is obviously not very applicable for on-line use when thousands of carcasses need to be classified in full production speed. This thesis presents the research into several spectroscopic methods (IR, NIR, Raman), each promising candidates for rapid...... quality, but also with environmental issues such as energy and water use and animal welfare. Future research into the technologies will ultimately allow broad on-line screening of biomarkers, leading to on-line metabolomics...

  12. Process Analytical Technology and On-Line Spectroscopic Measurements of Chemical Meat Quality

    DEFF Research Database (Denmark)

    Sørensen, Klavs Martin

    more time than is available on a slaughter line, it is obviously not very applicable for on-line use when thousands of carcasses need to be classified in full production speed. This thesis presents the research into several spectroscopic methods (IR, NIR, Raman), each promising candidates for rapid...... of the compounds and subsequent quantification by GC-MS or LC-MS analysis. On-line detection with sub-ppm sensitivity is a major challenge and thus spectroscopic candidates with the required capabilities in speed and sensitivity are researched. Thus, a Surface Enhanced Raman Scatter method is presented capable......This thesis deals with process analytical technology and how it can be implemented in the meat industry through on-line grading of chemical meat quality. The focus will be on two applications, namely the rapid quality control of fat quality and the development of a method for on-line detection...

  13. Submicrometer fiber-optic chemical sensors: Measuring pH inside single cells

    Science.gov (United States)

    Kopelman, R.

    Starting from scratch, we went in two and a half years to 0.04 micron optical microscopy resolution. We have demonstrated the application of near-field scanning optical microscopy to DNA samples and opened the new fields of near-field scanning spectroscopy and submicron opto-chemical sensors. All of these developments have been important steps towards in-situ DNA imaging and characterization on the nanoscale. Our first goal was to make NSOM (near-field scanning optical microscopy) a working enterprise, capable of 'zooming-in' towards a sample and imaging with a resolution exceeding that of traditional microscopy by a factor of ten. This has been achieved. Not only do we have a resolution of about 40 nm but we can image a 1 x 1 micron object in less than 10 seconds. Furthermore, the NSOM is a practical instrument. The tips survive for days or weeks of scanning and new methods of force feedback will soon protect the most fragile samples. Reproducible images of metal gratings, gold particles, dye balls (for calibration) and of several DNA samples have been made, proving the practicality of our approach. We also give highly resolved Force/NSOM images of human blood cells. Our second goal has been to form molecular optics (e.g., exciton donor) tips with a resolution of 2-10 nm for molecular excitation microscopy (MEM). We have produced such tips, and scanned with them, but only with a resolution comparable to that of our standard NSOM tips. However, we have demonstrated their potential for high resolution imaging capabilities: (1) An energy transfer (tip to sample) based feedback capability. (2) A Kasha (external heavy atom) effect based feedback. In addition, a novel and practical opto-chemical sensor that is a billion times smaller than the best ones available has been developed as well. Finally, we have also performed spatially resolved fluorescence spectroscopy.

  14. Global contamination trends of persistent organic chemicals

    National Research Council Canada - National Science Library

    Loganathan, Bommanna G; Lam, Paul K. S

    2012-01-01

    "Composed by a diverse group of experts, this reference covers the history, present status, and projected future trends of environmental contamination from highly toxic synthetic chemical pollutants...

  15. Optimisation of elevated radon concentration measurement by using electro-chemical etching of nuclear track detectors

    International Nuclear Information System (INIS)

    Celikovic, I.; Ujic, P.; Fujimoto, K.; Tommasino, L.; Demajo, A.; Zunic, Z.; Celikovic, I.)

    2007-01-01

    In the paper, two methods for adjusting of passive radon-thoron discriminative dosimeters (UFO detector) for enhanced radon concentration measurement are presented. Achieved upper limit of detection is 5.94 MBq m-3 d [sr

  16. Efficacy of monitoring the sensory taste characteristics in pomegranate juice with electronic tongue, and chemical measurements

    Science.gov (United States)

    In addition to flavor attributes, pomegranate juices have sweet, sour, bitter tastes, astringent, and toothetch feeling factors. Many factors influence tastes and feeling factors. Measuring these attributes without a sensory panel makes economic sense. This investigation compares descriptive sensory...

  17. Chemically-resolved aerosol eddy covariance flux measurements in urban Mexico City during MILAGRO 2006

    Science.gov (United States)

    Zalakeviciute, R.; Alexander, M. L.; Allwine, E.; Jimenez, J. L.; Jobson, B. T.; Molina, L. T.; Nemitz, E.; Pressley, S. N.; VanReken, T. M.; Ulbrich, I. M.; Velasco, E.; Lamb, B. K.

    2012-08-01

    As part of the MILAGRO 2006 field campaign, the exchange of atmospheric aerosols with the urban landscape was measured from a tall tower erected in a heavily populated neighborhood of Mexico City. Urban submicron aerosol fluxes were measured using an eddy covariance method with a quadrupole aerosol mass spectrometer during a two week period in March, 2006. Nitrate and ammonium aerosol concentrations were elevated at this location near the city center compared to measurements at other urban sites. Significant downward fluxes of nitrate aerosol, averaging -0.2 μg m-2 s-1, were measured during daytime. The urban surface was not a significant source of sulfate aerosols. The measurements also showed that primary organic aerosol fluxes, approximated by hydrocarbon-like organic aerosols (HOA), displayed diurnal patterns similar to CO2 fluxes and anthropogenic urban activities. Overall, 47% of submicron organic aerosol emissions were HOA, 35% were oxygenated (OOA) and 18% were associated with biomass burning (BBOA). Organic aerosol fluxes were bi-directional, but on average HOA fluxes were 0.1 μg m-2 s-1, OOA fluxes were -0.03 μg m-2 s-1, and BBOA fluxes were -0.03 μg m-2 s-1. After accounting for size differences (PM1 vs PM2.5) and using an estimate of the black carbon component, comparison of the flux measurements with the 2006 gridded emissions inventory of Mexico City, showed that the daily-averaged total PM emission rates were essentially identical for the emission inventory and the flux measurements. However, the emission inventory included dust and metal particulate contributions, which were not included in the flux measurements. As a result, it appears that the inventory underestimates overall PM emissions for this location.

  18. Advanced Chemical Measurements of Smoke from DoD-prescribed Burns

    Science.gov (United States)

    2014-04-01

    Least Squares The determination of component concentrations and ILS parameters from measured spectra is an inverse problem without a unique solution ... deforestation fires and thus consumed significant amounts of large diameter logs. Figure 7.5 Emission factors (g kg-1) as a function of MCE for the...fires (Yokelson et al., 2011) are fairly close to our fit line, but two are much higher. The high Mexican EF measurements were on deforestation

  19. A 3-step framework for understanding the added value of surface soil moisture measurements for large-scale runoff prediction via data assimilation - a synthetic study in the Arkansas-Red River basin

    Science.gov (United States)

    Mao, Y.; Crow, W. T.; Nijssen, B.

    2017-12-01

    Soil moisture (SM) plays an important role in runoff generation both by partitioning infiltration and surface runoff during rainfall events and by controlling the rate of subsurface flow during inter-storm periods. Therefore, more accurate SM state estimation in hydrologic models is potentially beneficial for streamflow prediction. Various previous studies have explored the potential of assimilating SM data into hydrologic models for streamflow improvement. These studies have drawn inconsistent conclusions, ranging from significantly improved runoff via SM data assimilation (DA) to limited or degraded runoff. These studies commonly treat the whole assimilation procedure as a black box without separating the contribution of each step in the procedure, making it difficult to attribute the underlying causes of runoff improvement (or the lack thereof). In this study, we decompose the overall DA process into three steps by answering the following questions (3-step framework): 1) how much can assimilation of surface SM measurements improve surface SM state in a hydrologic model? 2) how much does surface SM improvement propagate to deeper layers? 3) How much does (surface and deeper-layer) SM improvement propagate into runoff improvement? A synthetic twin experiment is carried out in the Arkansas-Red River basin ( 600,000 km2) where a synthetic "truth" run, an open-loop run (without DA) and a DA run (where synthetic surface SM measurements are assimilated) are generated. All model runs are performed at 1/8 degree resolution and over a 10-year period using the Variable Infiltration Capacity (VIC) hydrologic model at a 3-hourly time step. For the DA run, the ensemble Kalman filter (EnKF) method is applied. The updated surface and deeper-layer SM states with DA are compared to the open-loop SM to quantitatively evaluate the first two steps in the framework. To quantify the third step, a set of perfect-state runs are generated where the "true" SM states are directly inserted

  20. 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.

  1. 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...

  2. Synthetic growth reference charts

    NARCIS (Netherlands)

    Hermanussen, Michael; Stec, Karol; Aßmann, Christian; Meigen, Christof; Van Buuren, Stef

    2016-01-01

    Objectives: To reanalyze the between-population variance in height, weight, and body mass index (BMI), and to provide a globally applicable technique for generating synthetic growth reference charts. Methods: Using a baseline set of 196 female and 197 male growth studies published since 1831, common

  3. A formidable synthetic challenge

    Indian Academy of Sciences (India)

    Isolation and characterization of maoecrystal V, a C19 terpenoid, having potent and selective cytotoxicity towards HeLa cells was recently reported. Unusually complex pentacyclic molecular structure, presence of spirofused rings and several stereogenic centres posed a great synthetic challenge. In this short review, efforts ...

  4. Synthetic antiferromagnetic spintronics

    Science.gov (United States)

    Duine, R. A.; Lee, Kyung-Jin; Parkin, Stuart S. P.; Stiles, M. D.

    2018-03-01

    Spintronic and nanomagnetic devices often derive their functionality from layers of different materials and the interfaces between them. We discuss the opportunities that arise from synthetic antiferromagnets consisting of two or more ferromagnetic layers that are separated by metallic spacers or tunnel barriers and have antiparallel magnetizations.

  5. Applications of synthetic polymers in clinical medicine

    OpenAIRE

    Maitz, M.F.

    2015-01-01

    Multiple biological, synthetic and hybrid polymers are used for multiple medical applications. A wide range of different polymers is available, and they have further the advantage to be tunable in physical, chemical and biological properties in a wide range to match the requirements of specific applications. This review gives a brief overview about the introduction and developments of polymers in medicine in general, addressing first stable polymers, then polymers with degradability as a firs...

  6. Measurement and Modelling of Phase Equilibrium of Oil - Water - Polar Chemicals

    DEFF Research Database (Denmark)

    Frost, Michael Grynnerup

    with the measurement of newexperimental data, but through the development of new experimental equipment for the study ofmulti-phase equilibrium. In addition to measurement of well-defined systems, LLE have beenmeasured for North Sea oils with MEG and water. The work can be split up into two parts: Experimental: VLE......-waterflooding process act primarily as thickeners. The main purpose of this work, focusing on the phase equilibrium of complex systems containingthermodynamic gas hydrate inhibitors, is to give a solid contribution in bridging the existing gaps inwhat experimental data is concerned. This was achieved not just...... systems presented, confirming the quality of theequipment. The equipment is used for measurement of VLE for several systems of interest; methane+ water, methane + methanol, methane + methanol + water and methane + MEG. Details dealing with the design, assembling and testing of new experimental equipment...

  7. Synthetic Sling Failure - Evaluations and Recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, C. S. [Washington River Protection Solutions, Richland, WA (United States); Mackey, Thomas C. [Washington River Protection Solutions, Richland, WA (United States)

    2009-10-26

    The information and evaluations provided in this report were compiled to address the recurring problem of synthetic sling failure. As safety is the number one priority in all work aspects, a solution must be devised to prevent accidents from occurring. A total of thirteen cases regarding synthetic sling failure were evaluated in order to determine their causes, effects, and preventative measures. From the collected data, it was found that all cases in which the synthetic sling contacted the edge of its load resulted in sling failure. It is required that adequate synthetic sling protection devices be used to protect slings in any lift where the sling comes in direct contact with the edge or corner of its load. However, there are no consensus codes or standards stating the type, material, or purpose of the type of protective device used to protect the sling from being cut. Numerous industry standards and codes provide vague descriptions on how to protect synthetic slings. Without a clear, concise statement of how to protect synthetic slings, it is common for inadequate materials and sling protection devices to be used in an attempt to meet the intent of these requirements. The use of an inadequate sling protection device is the main cause of synthetic sling failure in all researched cases. Commercial sling protection devices come in many shapes and sizes, and have a variety of names, as well as advertised uses. 'Abrasion pads' and 'wear protectors' are two different names for products with the same intended purpose. There is no distinguishable way to determine the extent of sling protection which these devices will provide, or what specific scenarios they are made for. This creates room for error in a field where error is unacceptable. This report provides a recommended action for hoisting and rigging activities which require synthetic slings to contact a load, as well as recommended changes to industry standards which will benefit overall

  8. Investigation of discharged aerosol nanoparticles during chemical precipitation and spray pyrolysis for developing safety measures in the nano research laboratory.

    Science.gov (United States)

    Kolesnikov, Еvgeny; Karunakaran, Gopalu; Godymchuk, Anna; Vera, Levina; Yudin, Andrey Grigorjevich; Gusev, Alexander; Kuznetsov, Denis

    2017-05-01

    Nowadays, the demands for the nanoparticles are increasing due to their tremendous applications in various fields. As a consequence, the discharge of nanoparticles into the atmosphere and environment is also increasing, posing a health threat and environmental damage in terms of pollution. Thus, an extensive research is essential to evaluate the discharge of these nanoparticles into the environment. Keeping this in mind, the present investigation aimed to analyze the discharge of aerosol nanoparticles that are synthesized in the laboratory via chemical precipitation and spray pyrolysis methods. The results indicated that the chemical precipitation method discharges a higher concentration of nanoparticles in the work site when compared to the spray pyrolysis method. The aerosol concentration also varied with the different steps involved during the synthesis of nanoparticles. The average particle's concentration in air for chemical precipitation and spray pyrolysis methods was around 1,037,476 and 883,421particles/cm 3 . In addition, the average total discharge of nanoparticles in the entire laboratory was also examined. A significant variation in the concentration of nanoparticles was noticed, during the processing of materials and the concentration of particles (14-723nm) exceeding the daily allowed concentration to about 70-170 times was observed over a period of 6 months. Thus, the results of the present study will be very useful in developing safety measures and would help in organizing the rules for people working in nanotechnology laboratories to minimize the hazardous effects. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. In situ laser-induced breakdown spectroscopy measurements of chemical compositions in stainless steels during tungsten inert gas welding

    Science.gov (United States)

    Taparli, Ugur Alp; Jacobsen, Lars; Griesche, Axel; Michalik, Katarzyna; Mory, David; Kannengiesser, Thomas

    2018-01-01

    A laser-induced breakdown spectroscopy (LIBS) system was combined with a bead-on-plate Tungsten Inert Gas (TIG) welding process for the in situ measurement of chemical compositions in austenitic stainless steels during welding. Monitoring the weld pool's chemical composition allows governing the weld pool solidification behavior, and thus enables the reduction of susceptibility to weld defects. Conventional inspection methods for weld seams (e.g. ultrasonic inspection) cannot be performed during the welding process. The analysis system also allows in situ study of the correlation between the occurrence of weld defects and changes in the chemical composition in the weld pool or in the two-phase region where solid and liquid phase coexist. First experiments showed that both the shielding Ar gas and the welding arc plasma have a significant effect on the selected Cr II, Ni II and Mn II characteristic emissions, namely an artificial increase of intensity values via unspecific emission in the spectra. In situ investigations showed that this artificial intensity increase reached a maximum in presence of weld plume. Moreover, an explicit decay has been observed with the termination of the welding plume due to infrared radiation during sample cooling. Furthermore, LIBS can be used after welding to map element distribution. For austenitic stainless steels, Mn accumulations on both sides of the weld could be detected between the heat affected zone (HAZ) and the base material.

  10. Aerosol direct radiative effects over the northwest Atlantic, northwest Pacific, and North Indian Oceans: estimates based on in-situ chemical and optical measurements and chemical transport modeling

    Directory of Open Access Journals (Sweden)

    T. S. Bates

    2006-01-01

    Full Text Available The largest uncertainty in the radiative forcing of climate change over the industrial era is that due to aerosols, a substantial fraction of which is the uncertainty associated with scattering and absorption of shortwave (solar radiation by anthropogenic aerosols in cloud-free conditions (IPCC, 2001. Quantifying and reducing the uncertainty in aerosol influences on climate is critical to understanding climate change over the industrial period and to improving predictions of future climate change for assumed emission scenarios. Measurements of aerosol properties during major field campaigns in several regions of the globe during the past decade are contributing to an enhanced understanding of atmospheric aerosols and their effects on light scattering and climate. The present study, which focuses on three regions downwind of major urban/population centers (North Indian Ocean (NIO during INDOEX, the Northwest Pacific Ocean (NWP during ACE-Asia, and the Northwest Atlantic Ocean (NWA during ICARTT, incorporates understanding gained from field observations of aerosol distributions and properties into calculations of perturbations in radiative fluxes due to these aerosols. This study evaluates the current state of observations and of two chemical transport models (STEM and MOZART. Measurements of burdens, extinction optical depth (AOD, and direct radiative effect of aerosols (DRE – change in radiative flux due to total aerosols are used as measurement-model check points to assess uncertainties. In-situ measured and remotely sensed aerosol properties for each region (mixing state, mass scattering efficiency, single scattering albedo, and angular scattering properties and their dependences on relative humidity are used as input parameters to two radiative transfer models (GFDL and University of Michigan to constrain estimates of aerosol radiative effects, with uncertainties in each step propagated through the analysis. Constraining the radiative

  11. Accuracy, Precision, and Reliability of Chemical Measurements in Natural Products Research

    Science.gov (United States)

    Betz, Joseph M.; Brown, Paula N.; Roman, Mark C.

    2010-01-01

    Natural products chemistry is the discipline that lies at the heart of modern pharmacognosy. The field encompasses qualitative and quantitative analytical tools that range from spectroscopy and spectrometry to chromatography. Among other things, modern research on crude botanicals is engaged in the discovery of the phytochemical constituents necessary for therapeutic efficacy, including the synergistic effects of components of complex mixtures in the botanical matrix. In the phytomedicine field, these botanicals and their contained mixtures are considered the active pharmaceutical ingredient (API), and pharmacognosists are increasingly called upon to supplement their molecular discovery work by assisting in the development and utilization of analytical tools for assessing the quality and safety of these products. Unlike single-chemical entity APIs, botanical raw materials and their derived products are highly variable because their chemistry and morphology depend on the genotypic and phenotypic variation, geographical origin and weather exposure, harvesting practices, and processing conditions of the source material. Unless controlled, this inherent variability in the raw material stream can result in inconsistent finished products that are under-potent, over-potent, and/or contaminated. Over the decades, natural products chemists have routinely developed quantitative analytical methods for phytochemicals of interest. Quantitative methods for the determination of product quality bear the weight of regulatory scrutiny. These methods must be accurate, precise, and reproducible. Accordingly, this review discusses the principles of accuracy (relationship between experimental and true value), precision (distribution of data values), and reliability in the quantitation of phytochemicals in natural products. PMID:20884340

  12. High Altitude Pollution Program Stratospheric Measurement System Laboratory Performance Capability Report Chemical Conversion Techniques.

    Science.gov (United States)

    1980-02-01

    characteristic fluorescence can be measured. Also, the technique could be extended to NO by first converting NO to NO2 as is done in the chemilumine- scent ...bimolecular reactions with k7>> k9 , the differential rate equation for the intermediary, NO3 is given by d [NO3]l dt 2k19 [No2] [No3] + 2 k2 0 [NO3

  13. ChemDuino: Adapting Arduino for Low-Cost Chemical Measurements in Lecture and Laboratory

    Science.gov (United States)

    Kubínova´, S?te?pa´nka; S?le´gr, Jan

    2015-01-01

    In everyday praxis, we often need demonstration measuring devices (thermometers, pH meters, etc.), with large enough displays to be easily readable from every point in the classroom. Here, we present some of the capabilities of the Arduino platform for the school environment. This microprocessor board can be used for inexpensive construction of…

  14. Capabilities for measuring physical and chemical properties of rocks at high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Durham, W.B. (comp.)

    1990-01-01

    The Experimental Geophysics Group of the Earth Sciences Department at Lawrence Livermore National Laboratory (LLNL) has experimental equipment that measures a variety of physical properties and phase equilibria and kinetics on rocks and minerals at extreme pressures (to 500 GPa) and temperatures (from 10 to 2800 K). These experimental capabilities are described in this report in terms of published results, photographs, and schematic diagrams.

  15. Measurement of chemical activities of rare earths (RE: Ce, Pr, Sm and Eu) in cadmium alloy

    International Nuclear Information System (INIS)

    Ghosh, Sajal; Ganesan, Rajesh; Sridharan, R.; Gnanasekaran, T.

    2015-01-01

    Activity of rare earth (RE) elements, Ce, Pr, Sm and Eu is measured in each of the cadmium rich binary alloys of RE, by making use of a molten salt based electrochemical cell. The binary alloy consists of a mixture of cadmium rich intermetallic compound and a liquid phase of known composition. Four independent cells are constructed; one for each of the rare earth elements and electromotive force (EMF) is measured as a function of temperature for each cell, respectively. Partial molar Gibbs energy of these rare earth metals in liquid cadmium is derived from the EMF output over a temperature range. Gibbs energy of formation of CeCd 11 , PrCd 11, SmCd 6 and EuCd 11 are deduced from the measured EMF values and the reported literature data on the solubility of rare earth elements in liquid cadmium. - Highlights: • Activities of rare earth (RE) elements such as Ce, Pr, Sm and Eu were measured as a function of temperature in cadmium rich biphasic mixture. • Partial molar Gibbs energies of these rare earths in liquid cadmium were derived over a temperature range. • Gibbs energy of formation of CeCd 11 , PrCd 11, SmCd 6 and EuCd 11 were derived.

  16. Chemical Experiments Measuring ph and Gases on "Planetary" Soil by the HUSAR-5 NXT-based Rover Model

    Science.gov (United States)

    Lang, Agota; Bérczi, Szaniszló; Erdélyi, Soma; Nickl, Istvan; Kiss, Daniel; Erdősi, Ferenc; Panyi, Tamas; Szalay, Kristof

    2010-05-01

    Introduction: We report two chemical experiments studying the soil on the surface of a planet. Both experiments are built on the HUSAR-5 rover model (Hungarian University Surface Analyser Rover) in a Hungarian high school. In the first experiment our rover uses optical lens as classical heating experiment and gas-sensor to measure the chemical components liberated by the heating. In the second experiment we measure chemical characteristics of the soil by using the indicator method. We report the constructions and experiments carried out by our rover. The task of the first mission: The main goal of the experiment is to move and fix the lens so that the plane of the lens should be perpendicular to the axis of the incident solar light. It is important that the focus of the lens should reach the soil exactly, and it should be operated at any incidence position. We solved this problem using three motors. Two move the lens around horizontal axes, and the third one around a vertical one. The technological structure of HUSAR-5 instruments has been built from LEGO elements, driven by LEGO Mindstorms motors and controlled by NXT "brain". We used a photoresistor, whose signal was lead into the NXT. The steps of the measuring process are the followings I. For focusing: 1. Basic position: The lens is in resting position exactly a focus distance above the soil. The holding arm is horizontal, and the plane of the lens is also horizontal, parallel to the soil. 2. After selecting the location of the measurement, the NXT first moves the lens and finds the position (with the help of the lightsensor) where the intensity of the light is the largest. 3. The other motor moves the arm up and down and positions the lens plane perpendicular to the solar lights. The program takes into the memory both measured angles. 4. The forth step is lifting up the arm into the necessary position. From the initial position the lifting motor states the arm to this position which is calculated by the

  17. Inter-laboratory comparison on the size and stability of monodisperse and bimodal synthetic reference particles for standardization of extracellular vesicle measurements

    NARCIS (Netherlands)

    Nicolet, Anais; Meli, Felix; van der Pol, Edwin; Yuana, Yuana; Gollwitzer, Christian; Krumrey, Michael; Cizmar, Petr; Buhr, Egbert; Petry, Jasmine; Sebaihi, Noham; de Boeck, Bert; Fokkema, Vincent; Bergmans, Rob; Nieuwland, Rienk

    2016-01-01

    In future, measurements of extracellular vesicles in body fluids could become a standard diagnostic tool in medicine. For this purpose, reliable and traceable methods, which can be easily applied in hospitals, have to be established. Within the European Metrological Research Project (EMRP)

  18. Synthetic strategies for studying embryonic development.

    Science.gov (United States)

    Ouyang, Xiaohu; Chen, James K

    2010-06-25

    Developmental biology has evolved from a descriptive science to one based on genetic principles and molecular mechanisms. Although molecular biology and genetic technologies have been the primary drivers of this transformation, synthetic strategies have been increasingly utilized to interrogate the mechanisms of embryonic patterning with spatial and temporal precision. In this review, we survey how chemical tools and engineered proteins have been used to perturb developmental processes at the DNA, RNA, protein, and cellular levels. We discuss the design principles, experimental capabilities, and limitations of each method, as well as future challenges for the chemical and developmental biology communities.

  19. Synthetic antifreeze peptide and synthetic gene coding for its production

    OpenAIRE

    1991-01-01

    A synthetic antifreeze peptide and a synthetic gene coding for the antifreeze peptide have been produced. The antifreeze peptide has a greater number of repeating amino acid sequences than is present in the native antifreeze peptides from winter flounder upon which the synthetic antifreeze peptide was modeled. Each repeating amino acid sequence has two polar amino acid residues which are spaced a controlled distance apart so that the antifreeze peptide may inhibit ice formation. The synthetic...

  20. Meeting the measurement uncertainty and traceability requirements of ISO/AEC standard 17025 in chemical analysis.

    Science.gov (United States)

    King, B

    2001-11-01

    The new laboratory accreditation standard, ISO/IEC 17025, reflects current thinking on good measurement practice by requiring more explicit and more demanding attention to a number of activities. These include client interactions, method validation, traceability, and measurement uncertainty. Since the publication of the standard in 1999 there has been extensive debate about its interpretation. It is the author's view that if good quality practices are already in place and if the new requirements are introduced in a manner that is fit for purpose, the additional work required to comply with the new requirements can be expected to be modest. The paper argues that the rigour required in addressing the issues should be driven by customer requirements and the factors that need to be considered in this regard are discussed. The issues addressed include the benefits, interim arrangements, specifying the analytical requirement, establishing traceability, evaluating the uncertainty and reporting the information.

  1. Using an Array of Ion Mobility Spectrometers in the Field for Real-Time Reporting of Chemical Vapor Concentration Measurements

    National Research Council Canada - National Science Library

    Blethen, Gretchen E; Harden, Charles S; McHugh, Vincent M; Shoff, Donal B; Ince, Brian S; Harper, Stephen E; Schafer, Robert J; Arnold, Paul D; Pavitt, Simon W; Thomas, Martin A; Espander, William R; Ciborowski, Steven M

    2004-01-01

    Field tests were carried out where hundreds of kilograms of chemical agent surrogates were explosively disseminated to gather real time chemical concentration information at specific ground locations...

  2. X-ray microprobe measurements of the chemical compositions of ALH84001 carbonate globules

    International Nuclear Information System (INIS)

    Flynn, G.J.; Sutton, S.R.; Keller, L.P.

    2004-01-01

    We measured minor element contents of carbonate from ALH84001 and report trends in tbe Ca, V, Mn and Sr in carbonate and the associated magnetite bands. McKay et al. suggested that carbonate globules in the ALH84001 meteorite from Mars contained evidence consistent with the development of bacterial life early in the history of Mars. This result provoked an extensive study of the ALH84001 meteorite. More recently Thomas-Keprta et al. have published a study showing that the magnetite associated with carbonate rims are of the size and shape produced by terrestrial bacteria. This paper has revived interest in ALH84001. The typical ALH84001 carbonate globule consists of four regions: a core of Fe-rich carbonate, a thin magnetite-rich band, a rim of Mn-rich carbonate, and another thin magnetite-rich band. Trace element analysis of each of these phases may allow us to address several important questions about these carbonates: (1) The origin of the magnetite-rich bands in the ALH84001 carbonate globules. If the magnetites are derived from the underlying carbonate through thermal decomposition (as proposed by Golden et al.), then we expect to see 'inherited' trace elements in these magnetite bands. (2) The origin of the rim carbonate, by determining whether the carbonate in the core has the same trace elements as the rim carbonates. (3) The age of the rim carbonate. Borg et al. dated the formation of the rim carbonate using the Rb/Sr chronometer. Borg et al. performed their measurements on an aliquot of what they called a high-Rb, low-Sr carbonate separate from the rim. We previously measured the trace element contents of chips from core and rim carbonates from an ALH84001 carbonate globule using an X-Ray Microprobe on Beamline X26A at the National Synchrotron Light Source. These measurements showed the rim carbonate had a very low Rb content, with Sr>>Rb, inconsistent with the ∼5 ppm Rb reported by Borg et al. in the sample they dated by the Rb/Sr chronometer. The large

  3. Inverse modeling of CO2 sources and sinks using satellite data: a synthetic inter-comparison of measurement techniques and their performance as a function of space and time

    Directory of Open Access Journals (Sweden)

    S. Houweling

    2004-01-01

    Full Text Available Currently two polar orbiting satellite instruments measure CO2 concentrations in the Earth's atmosphere, while other missions are planned for the coming years. In the future such instruments might become powerful tools for monitoring changes in the atmospheric CO2 abundance and to improve our quantitative understanding of the leading processes controlling this. At the moment, however, we are still in an exploratory phase where first experiences are collected and promising new space-based measurement concepts are investigated. This study assesses the potential of some of these concepts to improve CO2 source and sink estimates obtained from inverse modelling. For this purpose the performance of existing and planned satellite instruments is quantified by synthetic simulations of their ability to reduce the uncertainty of the current source and sink estimates in comparison with the existing ground-based network of sampling sites. Our high resolution inversion of sources and sinks (at 8°x10° allows us to investigate the variation of instrument performance in space and time and at various temporal and spatial scales. The results of our synthetic tests clearly indicate that the satellite performance increases with increasing sensitivity of the instrument to CO2 near the Earth's surface, favoring the near infra-red technique. Thermal infrared instruments, on the contrary, reach a better global coverage, because the performance in the near infrared is reduced over the oceans owing to a low surface albedo. Near infra-red sounders can compensate for this by measuring in sun-glint, which will allow accurate measurements over the oceans, at the cost, however, of a lower measurement density. Overall, the sun-glint pointing near infrared instrument is the most promising concept of those tested. We show that the ability of satellite instruments to resolve fluxes at smaller temporal and spatial scales is also related to surface sensitivity. All the satellite

  4. Characterizing the Asian Tropopause Aerosol Layer (ATAL) Using Satellite Observations, Balloon Measurements and a Chemical Transport Model

    Science.gov (United States)

    Fairlie, T. D.; Vernier, J.-P.; Liu, H.; Deshler, T.; Natarajan, M.; Bedka, K.; Wegner, T.; Baker, N.; Gadhavi, H.; Ratnam, M. V.; hide

    2016-01-01

    Satellite observations and numerical modeling studies have demonstrated that the Asian Summer Monsoon (ASM) provide a conduit for gas-phase pollutants in south Asia to reach the lower stratosphere. Now, observations from the CALIPSO satellite have revealed the Asian Tropopause Aerosol Layer (ATAL), a summertime accumulation of aerosols in the upper troposphere and lower stratosphere (UTLS), associated with the ASM anticyclone. The ATAL has potential implications for regional cloud properties, climate, and chemical processes in the UTLS. Here, we show in situ measurements from balloon-borne instruments, aircraft, and satellite observations, together with trajectory and chemical transport model (CTM) simulations to explore the origin, composition, physical, and optical properties of aerosols in the ATAL. In particular, we show balloon-data from our BATAL-2015 field campaign to India and Saudi Arabia in summer 2015, which includes in situ backscatter measurements from COBALD instruments, and the first observations of size and volatility of aerosols in the ATAL layer using optical particle counters (OPCs). Back trajectory calculations initialized from CALIPSO observations point to deep convection over North India as a principal source of ATAL aerosols. Available aircraft observations suggest significant sulfur and carbonaceous components to the ATAL, which is supported by simulations using the GEOS-Chem CTM. Source elimination studies conducted with the GEOS-Chem indicate that ATAL aerosols originate primary from south Asian sources, in contrast with some earlier studies.

  5. Chemical Composition of Diagenetic Features at Lower Aeolis Mons, Mars as Measured by Curiosity's APXS

    Science.gov (United States)

    Berger, J. A.; Schmidt, M. E.; Gellert, R.; Boyd, N.; Campbell, J. L.; Desouza, E.; Fisk, M. R.; Perrett, G. M.; Thompson, L. M.; VanBommel, S.; Yen, A. S.

    2015-12-01

    Curiosity's APXS investigation of the Murray Fm. (sols 755 - 950) at lower Aeolis Mons (Mt. Sharp) in Gale Crater, Mars has revealed (Mg, Ni)-sulfate diagenetic features and dark gray Ca-rich veins. The (Mg, Ni)-sulfate features occur as ~2 cm wide dendritic and botryoidal concretions that stand out in relief ~1 cm above the mudstone surface. APXS rasters over the features (Moenkopi, Mammoth, Morrison, Rosamond, Potatoe; sols 758 - 810) resulted in 1:1 molar variation of S and Mg consistent with a MgSO4 phase. The sulfate is not pure; the features are a mixture of 10 - 15% MgSO4 with the host mudstone. This mixture suggests the sulfates precipitated within pre-existing pore spaces, or were partially dissolved and replaced by sediment, preserving the crystal morphology. The sulfate features are enriched in Ni (2000 - 4250 ppm), indicating Ni-sulfate. The Murray Fm. mudstones that host the diagenetic features range to high SiO2 (60-73 wt%) and have bulk elemental signatures that are consistent with alteration by acid leaching. Low MgO (3.0 wt%) and low Ni (100 - 300 ppm) in the most apparently altered (highest SiO2) mudstones may link the acidic alteration with the fluids that formed the (Mg, Ni)-sulfates. Diagenetic Ca-sulfate-bearing veins that were abundant across Aeolis Palus persist at lower Aeolis Mons. A new vein type containing dark gray material as a separate crystalline phase within white Ca-sulfate veins was discovered in a cluster of veins in the Murray Fm. (Coalville, Alvord Mt., Amboy; sols 930 - 948). APXS rasters of the dark-toned material indicate high CaO (20 - 30 wt%) without concomitant increases in SO3. Ge (up to 650 ppm; 6.5X surrounding bedrock) and MnO (up to 1.0 wt%; 4X surrounding bedrock) are both enriched in the dark veins. These chemical observations are consistent with fluorite, although F (L.O.D. >5%) is not detectable in APXS spectra. The diagenetic features indicate that Ca, Mg, and Ni were mobilized with S in aqueous fluids, and that

  6. Synthetic Biology: Engineering Living Systems from Biophysical Principles.

    Science.gov (United States)

    Bartley, Bryan A; Kim, Kyung; Medley, J Kyle; Sauro, Herbert M

    2017-03-28

    Synthetic biology was founded as a biophysical discipline that sought explanations for the origins of life from chemical and physical first principles. Modern synthetic biology has been reinvented as an engineering discipline to design new organisms as well as to better understand fundamental biological mechanisms. However, success is still largely limited to the laboratory and transformative applications of synthetic biology are still in their infancy. Here, we review six principles of living systems and how they compare and contrast with engineered systems. We cite specific examples from the synthetic biology literature that illustrate these principles and speculate on their implications for further study. To fully realize the promise of synthetic biology, we must be aware of life's unique properties. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  7. Chemical and microbiological investigations on mineral-oil contaminated soils following on-site regeneration measures

    International Nuclear Information System (INIS)

    Hollerbach, A.; Teschner, M.; Bosecker, K.; Wehner, H.; Kassner, H.

    1992-01-01

    In the site of a former petroleum refinery, where bombing during the second World War has caused in part deep-down contamination of the ground with petroleum and its products, a pilot study with five on-site biological treatment beds was carried through by different firms with the aim to reduce the hydrocarbon content of the soil to 1 gramme per kilogramme of dry weight. Thus, good comparability of the different regeneration measures was given. Sampling was done at the end of the regeneration experiments by obtaining an average sample. (orig.) [de

  8. Standardization in synthetic biology.

    Science.gov (United States)

    Müller, Kristian M; Arndt, Katja M

    2012-01-01

    Synthetic Biology is founded on the idea that complex biological systems are built most effectively when the task is divided in abstracted layers and all required components are readily available and well-described. This requires interdisciplinary collaboration at several levels and a common understanding of the functioning of each component. Standardization of the physical composition and the description of each part is required as well as a controlled vocabulary to aid design and ensure interoperability. Here, we describe standardization initiatives from several disciplines, which can contribute to Synthetic Biology. We provide examples of the concerted standardization efforts of the BioBricks Foundation comprising the request for comments (RFC) and the Registry of Standardized Biological parts as well as the international Genetically Engineered Machine (iGEM) competition.

  9. Inter-laboratory comparison on the size and stability of monodisperse and bimodal synthetic reference particles for standardization of extracellular vesicle measurements

    Science.gov (United States)

    Nicolet, Anaïs; Meli, Felix; van der Pol, Edwin; Yuana, Yuana; Gollwitzer, Christian; Krumrey, Michael; Cizmar, Petr; Buhr, Egbert; Pétry, Jasmine; Sebaihi, Noham; de Boeck, Bert; Fokkema, Vincent; Bergmans, Rob; Nieuwland, Rienk

    2016-03-01

    In future, measurements of extracellular vesicles in body fluids could become a standard diagnostic tool in medicine. For this purpose, reliable and traceable methods, which can be easily applied in hospitals, have to be established. Within the European Metrological Research Project (EMRP) ‘Metrological characterization of micro-vesicles from body fluids as non-invasive diagnostic biomarkers’ (www.metves.eu), various nanoparticle reference materials were developed and characterized. We present results of an international comparison among four national metrology institutes and a university hospital. The size distributions of five monodisperse and two bimodal spherical particle samples with diameters ranging from 50 nm to 315 nm made out of silica and polystyrene were compared. Furthermore, the stability of the samples was verified over a period of 18 months. While monodisperse reference particle samples above a certain size level lead to good agreements of the size measurements among the different methods, small and bimodal samples show the limitations of current ‘clinical’ methods. All samples proved to be stable within the uncertainty of the applied methods.

  10. Inter-laboratory comparison on the size and stability of monodisperse and bimodal synthetic reference particles for standardization of extracellular vesicle measurements

    International Nuclear Information System (INIS)

    Nicolet, Anaïs; Meli, Felix; Van der Pol, Edwin; Yuana, Yuana; Nieuwland, Rienk; Gollwitzer, Christian; Krumrey, Michael; Cizmar, Petr; Buhr, Egbert; Pétry, Jasmine; Sebaihi, Noham; De Boeck, Bert; Fokkema, Vincent; Bergmans, Rob

    2016-01-01

    In future, measurements of extracellular vesicles in body fluids could become a standard diagnostic tool in medicine. For this purpose, reliable and traceable methods, which can be easily applied in hospitals, have to be established. Within the European Metrological Research Project (EMRP) ‘Metrological characterization of micro-vesicles from body fluids as non-invasive diagnostic biomarkers’ (www.metves.eu), various nanoparticle reference materials were developed and characterized. We present results of an international comparison among four national metrology institutes and a university hospital. The size distributions of five monodisperse and two bimodal spherical particle samples with diameters ranging from 50 nm to 315 nm made out of silica and polystyrene were compared. Furthermore, the stability of the samples was verified over a period of 18 months. While monodisperse reference particle samples above a certain size level lead to good agreements of the size measurements among the different methods, small and bimodal samples show the limitations of current ‘clinical’ methods. All samples proved to be stable within the uncertainty of the applied methods. (paper)

  11. Final Report for SERDP Project RC-1649: Advanced Chemical Measurements of Smoke from DoD-prescribed Burns

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Timothy J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weise, David [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lincoln, E. N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sams, Robert L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cameron, Melanie [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Veres, Patrick [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Yokelson, Robert J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Urbanski, Shawn [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Profeta, Luisa T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Williams, S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gilman, Jessica [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kuster, W. C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Akagi, Sheryl [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stockwell, Chelsea E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mendoza, Albert [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wold, Cyle E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Warneke, Carsten [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); de Gouw, Joost A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burling, Ian R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Reardon, James [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schneider, Matthew D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Griffith, David W.T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Roberts, James M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-12-17

    Objectives: Project RC-1649, “Advanced Chemical Measurement of Smoke from DoD-prescribed Burns” was undertaken to use advanced instrumental techniques to study in detail the particulate and vapor-phase chemical composition of the smoke that results from prescribed fires used as a land management tool on DoD bases, particularly bases in the southeastern U.S. The statement of need (SON) called for “(1) improving characterization of fuel consumption” and “(2) improving characterization of air emissions under both flaming and smoldering conditions with respect to volatile organic compounds, heavy metals, and reactive gases.” The measurements and fuels were from several bases throughout the southeast (Camp Lejeune, Ft. Benning, and Ft. Jackson) and were carried out in collaboration and conjunction with projects 1647 (models) and 1648 (particulates, SW bases). Technical Approach: We used an approach that featured developing techniques for measuring biomass burning emission species in both the laboratory and field and developing infrared (IR) spectroscopy in particular. Using IR spectroscopy and other methods, we developed emission factors (EF, g of effluent per kg of fuel burned) for dozens of chemical species for several common southeastern fuel types. The major measurement campaigns were laboratory studies at the Missoula Fire Sciences Laboratory (FSL) as well as field campaigns at Camp Lejeune, NC, Ft. Jackson, SC, and in conjunction with 1648 at Vandenberg AFB, and Ft. Huachuca. Comparisons and fusions of laboratory and field data were also carried out, using laboratory fuels from the same bases. Results: The project enabled new technologies and furthered basic science, mostly in the area of infrared spectroscopy, a broadband method well suited to biomass burn studies. Advances in hardware, software and supporting reference data realized a nearly 20x improvement in sensitivity and now provide quantitative IR spectra for potential detection of ~60 new

  12. Optical synthetic aperture radar

    Science.gov (United States)

    Ilovitsh, Asaf; Zach, Shlomo; Zalevsky, Zeev

    2013-06-01

    A method is proposed for increasing the resolution of an object and overcoming the diffraction limit of an optical system installed on top of a moving imaging system, such as an airborne platform or satellite. The resolution improvement is obtained via a two-step process. First, three low resolution differently defocused images are captured and the optical phase is retrieved using an improved iterative Gershberg-Saxton based algorithm. The phase retrieval allows numerical back propagation of the field to the aperture plane. Second, the imaging system is shifted and the first step is repeated. The obtained optical fields at the aperture plane are combined and a synthetically increased lens aperture is generated along the direction of movement, yielding higher imaging resolution. The method resembles a well-known approach from the microwave regime called the synthetic aperture radar in which the antenna size is synthetically increased along the platform propagation direction. The proposed method is demonstrated via Matlab simulation as well as through laboratory experiment.

  13. Rural measurements of the chemical composition of airborne particles in the Eastern United States

    International Nuclear Information System (INIS)

    Wolff, G.T.; Kelly, N.A.; Ferman, M.A.; Morrissey, M.L.

    1983-01-01

    Quantitative measurements of particulate composition was made at three rural sites: in central South Dakota, on the Louisiana Gulf Coastal, and in the Blue Ridge Mountains of Virginia. The first two sites were selected to determine background concentrations in continental polar and maritime tropical air masses, respectively, which affect the eastern United State during the summer. The Virginia site was selected as a receptor site, downwind of the midwestern source area. The South Dakota data established the background concentrations. These concentrations were similar to the levels in Louisiana when air parcels arrived from the Gulf of Mexico, without recently passing over the United States. Levels of fine particles (diameters less than 2.5 μm) were highest in Virginia and were due chiefly to sulfate. Using trajectory and statistical analyses, it is shown that the residence time of an air parcel over the midwestern source area was the most important variable in determining the sulface levels in the Blue Ridge Mountains

  14. Link between aerosol optical, microphysical and chemical measurements in an underground railway station in Paris

    Science.gov (United States)

    Raut, J.-C.; Chazette, P.; Fortain, A.

    Measurements carried out in Paris Magenta railway station in April-May 2006 underlined a repeatable diurnal cycle of aerosol concentrations and optical properties. The average daytime PM 10 and PM 2.5 concentrations in such a confined space were approximately 5-30 times higher than those measured in Paris streets. Particles are mainly constituted of dust, with high concentrations of iron and other metals, but are also composed of black and organic carbon. Aerosol levels are linked to the rate at which rain and people pass through the station. Concentrations are also influenced by ambient air from the nearby streets through tunnel ventilation. During daytime approximately 70% of aerosol mass concentrations are governed by coarse absorbing particles with a low Angström exponent (˜0.8) and a low single-scattering albedo (˜0.7). The corresponding aerosol density is about 2 g cm -3 and their complex refractive index at 355 nm is close to 1.56-0.035 i. The high absorption properties are linked to the significant proportion of iron oxides together with black carbon in braking systems. During the night, particles are mostly submicronic, thus presenting a greater Angström exponent (˜2). The aerosol density is lower (1.8 g cm -3) and their complex refractive index presents a lower imaginary part (1.58-0.013 i), associated to a stronger single-scattering albedo (˜0.85-0.90), mostly influenced by the ambient air. For the first time we have assessed the emission (deposition) rates in an underground station for PM 10, PM 2.5 and black carbon concentrations to be 3314 ± 781(-1164 ± 160), 1186 ± 358(-401 ± 66) and 167 ± 46(-25 ± 9) μg m -2 h -1, respectively.

  15. The spectral and chemical measurement of pollutants on snow near South Pole, Antarctica

    Science.gov (United States)

    Casey, K. A.; Kaspari, S. D.; Skiles, S. M.; Kreutz, K.; Handley, M. J.

    2017-06-01

    Remote sensing of light-absorbing particles (LAPs), or dark colored impurities, such as black carbon (BC) and dust on snow, is a key remaining challenge in cryospheric surface characterization and application to snow, ice, and climate models. We present a quantitative data set of in situ snow reflectance, measured and modeled albedo, and BC and trace element concentrations from clean to heavily fossil fuel emission contaminated snow near South Pole, Antarctica. Over 380 snow reflectance spectra (350-2500 nm) and 28 surface snow samples were collected at seven distinct sites in the austral summer season of 2014-2015. Snow samples were analyzed for BC concentration via a single particle soot photometer and for trace element concentration via an inductively coupled plasma mass spectrometer. Snow impurity concentrations ranged from 0.14 to 7000 part per billion (ppb) BC, 9.5 to 1200 ppb sulfur, 0.19 to 660 ppb iron, 0.013 to 1.9 ppb chromium, 0.13 to 120 ppb copper, 0.63 to 6.3 ppb zinc, 0.45 to 82 parts per trillion (ppt) arsenic, 0.0028 to 6.1 ppb cadmium, 0.062 to 22 ppb barium, and 0.0044 to 6.2 ppb lead. Broadband visible to shortwave infrared albedo ranged from 0.85 in pristine snow to 0.62 in contaminated snow. LAP radiative forcing, the enhanced surface absorption due to BC and trace elements, spanned from snow to 70 W m-2 for snow with high BC and trace element content. Measured snow reflectance differed from modeled snow albedo due to specific impurity-dependent absorption features, which we recommend be further studied and improved in snow albedo models.

  16. Brain imaging with synthetic MR in children: clinical quality assessment

    Energy Technology Data Exchange (ETDEWEB)

    Betts, Aaron M.; Serai, Suraj [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Leach, James L.; Jones, Blaise V. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); University of Cincinnati College of Medicine, Cincinnati, OH (United States); Zhang, Bin [Cincinnati Children' s Hospital Medical Center, Biostatistics and Epidemiology, Cincinnati, OH (United States)

    2016-10-15

    Synthetic magnetic resonance imaging is a quantitative imaging technique that measures inherent T1-relaxation, T2-relaxation, and proton density. These inherent tissue properties allow synthesis of various imaging sequences from a single acquisition. Clinical use of synthetic MR imaging has been described in adult populations. However, use of synthetic MR imaging has not been previously reported in children. The purpose of this study is to report our assessment of diagnostic image quality using synthetic MR imaging in children. Synthetic MR acquisition was obtained in a sample of children undergoing brain MR imaging. Image quality assessments were performed on conventional and synthetic T1-weighted, T2-weighted, and FLAIR images. Standardized linear measurements were performed on conventional and synthetic T2 images. Estimates of patient age based upon myelination patterns were also performed. Conventional and synthetic MR images were evaluated on 30 children. Using a 4-point assessment scale, conventional imaging performed better than synthetic imaging for T1-weighted, T2-weighted, and FLAIR images. When the assessment was simplified to a dichotomized scale, the conventional and synthetic T1-weighted and T2-weighted images performed similarly. However, the superiority of conventional FLAIR images persisted in the dichotomized assessment. There were no statistically significant differences between linear measurements made on T2-weighted images. Estimates of patient age based upon pattern of myelination were also similar between conventional and synthetic techniques. Synthetic MR imaging may be acceptable for clinical use in children. However, users should be aware of current limitations that could impact clinical utility in the software version used in this study. (orig.)

  17. Green chemistry for chemical synthesis

    Science.gov (United States)

    Li, Chao-Jun; Trost, Barry M.

    2008-01-01

    Green chemistry for chemical synthesis addresses our future challenges in working with chemical processes and products by inventing novel reactions that can maximize the desired products and minimize by-products, designing new synthetic schemes and apparati that can simplify operations in chemical productions, and seeking greener solvents that are inherently environmentally and ecologically benign. PMID:18768813

  18. Green chemistry for chemical synthesis

    OpenAIRE

    Li, Chao-Jun; Trost, Barry M.

    2008-01-01

    Green chemistry for chemical synthesis addresses our future challenges in working with chemical processes and products by inventing novel reactions that can maximize the desired products and minimize by-products, designing new synthetic schemes and apparati that can simplify operations in chemical productions, and seeking greener solvents that are inherently environmentally and ecologically benign.

  19. Green chemistry for chemical synthesis.

    Science.gov (United States)

    Li, Chao-Jun; Trost, Barry M

    2008-09-09

    Green chemistry for chemical synthesis addresses our future challenges in working with chemical processes and products by inventing novel reactions that can maximize the desired products and minimize by-products, designing new synthetic schemes and apparati that can simplify operations in chemical productions, and seeking greener solvents that are inherently environmentally and ecologically benign.

  20. An aircraft-borne chemical ionization – ion trap mass spectrometer (CI-ITMS for fast PAN and PPN measurements

    Directory of Open Access Journals (Sweden)

    H. Schlager

    2011-02-01

    Full Text Available An airborne chemical ionization ion trap mass spectrometer instrument (CI-ITMS has been developed for tropospheric and stratospheric fast in-situ measurements of PAN (peroxyacetyl nitrate and PPN (peroxypropionyl nitrate. The first scientific deployment of the FASTPEX instrument (FASTPEX = Fast Measurement of Peroxyacyl nitrates took place in the Arctic during 18 missions aboard the DLR research aircraft Falcon, within the framework of the POLARCAT-GRACE campaign in the summer of 2008. The FASTPEX instrument is described and characteristic properties of the employed ion trap mass spectrometer are discussed. Atmospheric data obtained at altitudes of up to ~12 km are presented, from the boundary layer to the lowermost stratosphere. Data were sampled with a time resolution of 2 s and a 2σ detection limit of 25 pmol mol−1. An isotopically labelled standard was used for a permanent on-line calibration. For this reason the accuracy of the PAN measurements is better than ±10% for mixing ratios greater than 200 pmol mol−1. PAN mixing ratios in the summer Arctic troposphere were in the order of a few hundred pmol mol−1 and generally correlated well with CO. In the Arctic boundary layer and lowermost stratosphere smaller PAN mixing ratios were observed due to a combination of missing local sources of PAN precursor gases and efficient removal processes (thermolysis/photolysis. PPN, the second most abundant PAN homologue, was measured simultaneously. Observed PPN/PAN ratios range between ~0.03 and 0.3.

  1. Measurement of chemical leaching potential of sulfate from landfill disposed sulfate containing wastes.

    Science.gov (United States)

    Sun, Wenjie; Barlaz, Morton A

    2015-02-01

    A number of sulfate-containing wastes are disposed in municipal solid wastes (MSW) landfills including residues from coal, wood, and MSW combustion, and construction and demolition (C&D) waste. Under anaerobic conditions that dominate landfills, the sulfate can be reduced to hydrogen sulfide which is problematic for several reasons including its low odor threshold, toxicity, and corrosive nature. The overall objective of this study was to evaluate existing protocols for the quantification of total leachable sulfate from solid samples and to compare their effectiveness and efficiency with a new protocol described in this study. Methods compared include two existing acid extraction protocols commonly used in the U.S., a pH neutral protocol that requires multiple changes of the leaching solution, and a new acid extraction method. The new acid extraction method was shown to be simple and effective to measure the leaching potential of sulfate from a range of landfill disposed sulfate-containing wastes. However, the acid extraction methods do not distinguish between sulfate and other forms of sulfur and are thus most useful when sulfate is the only form of sulfur present. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Optical fiber sensor technique for strain measurement during materials deposition, chemical reaction, and relaxation

    Science.gov (United States)

    Butler, M.A.; Ginley, D.S.

    1988-01-21

    Laser light from a common source is split and conveyed through two similar optical fibers and emitted at their respective ends to form an interference pattern, one of the optical fibers having a portion thereof subjected to a strain. Changes in the strain cause changes in the optical path length of the strain fiber, and generate corresponding changes in the interference pattern. The interference pattern is received and transduced into signals representative of fringe shifts corresponding to changes in the strain experienced by the strained one of the optical fibers. These signals are then processed to evaluate strain as a function of time, typical examples of the application of the apparatus including electrodeposition of a metallic film on a conductive surface provided on the outside of the optical fiber being strained, so that strains generated in the optical fiber during the course of the electrodeposition are measurable as a function of time. In one aspect of the invention, signals relating to the fringe shift are stored for subsequent processing and analysis, whereas in another aspect of the invention the signals are processed for real-time display of the strain changes under study. 9 figs.

  3. Synthetic Biology: Applications in the Food Sector.

    Science.gov (United States)

    Tyagi, Ashish; Kumar, Ashwani; Aparna, S V; Mallappa, Rashmi H; Grover, Sunita; Batish, Virender Kumar

    2016-08-17

    Synthetic biology also termed as "genomic alchemy" represents a powerful area of science that is based on the convergence of biological sciences with systems engineering. It has been fittingly described as "moving from reading the genetic code to writing it" as it focuses on building, modeling, designing and fabricating novel biological systems using customized gene components that result in artificially created genetic circuitry. The scientifically compelling idea of the technological manipulation of life has been advocated since long time. Realization of this idea has gained momentum with development of high speed automation and the falling cost of gene sequencing and synthesis following the completion of the human genome project. Synthetic biology will certainly be instrumental in shaping the development of varying areas ranging from biomedicine, biopharmaceuticals, chemical production, food and dairy quality monitoring, packaging, and storage of food and dairy products, bioremediation and bioenergy production, etc. However, potential dangers of using synthetic life forms have to be acknowledged and adoption of policies by the scientific community to ensure safe practice while making important advancements in the ever expanding field of synthetic biology is to be fully supported and implemented.

  4. [Exogenous surfactant therapy: new synthetic surfactants].

    Science.gov (United States)

    Lacaze-Masmonteil, Th

    2008-06-01

    There are numerous pulmonary conditions in which qualitative or quantitative anomalies of the surfactant system have been demonstrated. In premature newborns with immature lungs, a functional deficit in surfactant is the main physiopathologic mechanism of the neonatal respiratory distress syndrome (RDS). Since the landmark pilot study of Fujiwara, published more than 20 years ago, the efficacy of exogenous surfactant for the treatment of neonatal RDS has been established by numerous controlled studies and meta-analyses. Enlightened by a growing insight into both the structure and function of the different surfactant components, a new generation of synthetic surfactants has been developed. Various complementary approaches have confirmed the fundamental role of the two hydrophobic proteins, SP-B and SP-C, in the surfactant system, thus opening the way to the design of analogues, either by chemical synthesis or expression in a prokaryotic system. An example of these peptide-containing synthetic surfactant preparations, lucinactant (Surfaxin), has been recently tested in comparison to a synthetic surfactant that does not contain protein as well as to animal derived surfactant preparations. Major clinical outcomes between lucinactant and animal-derived surfactant preparations were fund similar in two randomized controlled trials, opening the way to a new generation of synthetic surfactants in the near future.

  5. Semiquantitative and quantitative measurements for EDXRF in elemental chemical composition of pigments

    International Nuclear Information System (INIS)

    Costa, Elizabeth Cristina Soares da

    2005-02-01

    X-Ray fluorescence technique is largely used in the characterization of art and archaeological objects for restoration and conservation, allowing a multi-elemental, simultaneous and non destructive analysis. In this work it was used a portable XRF equipment of XRF that consists of a 238 Pu source ( 13,6 and 17,2 keV; 95 mCi) and a SI-PIN detector coupled to a 8 k multichannel analyser. The results were collected by a palmtop computer and later analysed in a PC, through the program AXIL-QXAS. The acquisition time for each measurement was 500 s. The measurements were accomplished in a wood sculpture (Santa Luzia image, number 164) from the collection of the Museu de Etnologia da Universidade de Sao Paulo (MAE-USP), in the following regions: (STL1) inferior side of the wood base exposed without finishing, (STL2) frontal inferior base of the pedestal (dark blue) (STL3), inferior part of the frontal dress (gold), (STL4) medium part of the dress (clear blue) (STL5) mantle (red), (STL6) back central lock of the hair in the backs (black), (STL7) right cheek (flesh-coloured) and (STL8) mantle (gold). The elements found in the STL1 region were: Al, Ca, Fe and a high concentration of Zn. In the region STL2 were found Al, C, Fe, Zn and the key element Cu. In the region STL3 - Ca, Zn and the key element Au. In the region STL4 it was found Zn and the key element Cu. In the region STL5 the key element S and Hg. In the region STL6 were found Fe, Ca, S and Hg. In the region STL 7 were found Al, Cu, Hg and Zn. In the region STL8 were found Ca, Al and Au, with high concentration. It was concluded that the possible pigments would be: STL2 and STL4 - CuCO 3 . Cu(OH) 2 + ZnO; STL3 and STL8 - Au; STL5 - HgS, STL6 - HgS mixed with other oxides, possibly of Fe and Mn, and STL 7 - HgS + ZnO. Standard samples of wood painted with pigments of the colors white, blue, red, rose, flesh color and green were also made. Through the XRF method it was verified that the white pigment is TiO 2 , the

  6. Synthetic cannabis and respiratory depression.

    Science.gov (United States)

    Jinwala, Felecia N; Gupta, Mayank

    2012-12-01

    In recent years, synthetic cannabis use has been increasing in appeal among adolescents, and its use is now at a 30 year peak among high school seniors. The constituents of synthetic cannabis are difficult to monitor, given the drug's easy accessibility. Currently, 40 U.S. states have banned the distribution and use of some known synthetic cannabinoids, and have included these drugs in the Schedule I category. The depressive respiratory effect in humans caused by synthetic cannabis inhalation has not been thoroughly investigated in the medical literature. We are the first to report, to our knowledge, two cases of self-reported synthetic cannabis use leading to respiratory depression and necessary intubation.

  7. Surface-Satellite Measurements for Atmospheric Radiative Transfer (SMART)and Chemical, Optical and Microphysical Measurements of In-Situ Troposphere (COMMIT) Research Activities

    Science.gov (United States)

    Tsay, Si-Chee

    2004-01-01

    The GSFC SMART consists of a suite of remote sensing instruments, including many commercially available radiometers, spectrometer, interferometer, and three in-house developed inskuments: micro-pulse lidar (MPL), scanning microwave radiometer (SMiR), and sun-sky-surface photometer (S(sup 3)). SMART cover the spectral range from UV to microwave, and passive to active remote sensing. This is to enrich the EOS-like research activities (i.e., EOS validation, innovative investigations, and long-term local environmental observations). During past years, SMART has been deployed in many NASA supported field campaigns to collocate with satellite nadir overpass for intercomparisons, and for initializing model simulations. Built on the successful experience of SMART, we are currently developing a new ground-based in-situ sampling package, COMMIT, including measurements of trace gases (CO, SO2, NOx, and O3,) concentrations, fine/coarse particle sizers and chemical composition, single- and three-wavelength nephelometers, and surface meteorological probes. COMMIT is built for seeking a relationship between surface in-situ measurements and boundary layer characteristics. This is to enrich EOS-like research on removing boundary layer signal from the entire column from space observation - to deduce the stable (less variability) free-troposphere observations. The COMMIT will try its best to link the chemical, microphysical, and optical properties of the boundary layer with radiation. The next major activities for SMART-COMMIT are scheduled for 2004-2006 in BASE-ASIA and EAST-AIRE. The expected close collaboration of BASE-ASIA with various research projects in Asia (i.e., ABC in South Asia, led by Ramanathan et al.; EAST-AIRE in East Asia, led by Li et al.; and APEX in Northeast Asia, led by Nakajima et al.) will definitely provide a better understanding of the impact of the biomass burning and air pollutants on regional-to-global climate, hydrological and carbon cycles, and

  8. Wind energy applications of synthetic aperture radar

    DEFF Research Database (Denmark)

    Badger, Merete

    Synthetic aperture radars (SAR), mounted on satellites or aircraft, have proven useful for ocean wind mapping. Wind speeds at the height 10 m may be retrieved from measurements of radar backscatter using empirical model functions. The resulting windfields are valuable in offshore wind energy...

  9. Synthetic quorum sensing in model microcapsule colonies

    Science.gov (United States)

    Shum, Henry; Balazs, Anna C.

    2017-08-01

    Biological quorum sensing refers to the ability of cells to gauge their population density and collectively initiate a new behavior once a critical density is reached. Designing synthetic materials systems that exhibit quorum sensing-like behavior could enable the fabrication of devices with both self-recognition and self-regulating functionality. Herein, we develop models for a colony of synthetic microcapsules that communicate by producing and releasing signaling molecules. Production of the chemicals is regulated by a biomimetic negative feedback loop, the “repressilator” network. Through theory and simulation, we show that the chemical behavior of such capsules is sensitive to both the density and number of capsules in the colony. For example, decreasing the spacing between a fixed number of capsules can trigger a transition in chemical activity from the steady, repressed state to large-amplitude oscillations in chemical production. Alternatively, for a fixed density, an increase in the number of capsules in the colony can also promote a transition into the oscillatory state. This configuration-dependent behavior of the capsule colony exemplifies quorum-sensing behavior. Using our theoretical model, we predict the transitions from the steady state to oscillatory behavior as a function of the colony size and capsule density.

  10. 3rd congress on applied synthetic biology in Europe (Costa da Caparica, Portugal, February 2016).

    Science.gov (United States)

    Cueva, Miguel

    2017-03-25

    The third meeting organised by the European Federation of Biotechnology (EFB) on advances in Applied Synthetic Biotechnology in Europe (ASBE) was held in Costa da Caparica, Portugal, in February 2016. Abundant novel applications in synthetic biology were described in the six sessions of the meeting, which was divided into technology and tools for synthetic biology (I, II and III), bionanoscience, biosynthetic pathways and enzyme synthetic biology, and metabolic engineering and chemical manufacturing. The meeting presented numerous methods for the development of novel synthetic strains, synthetic biological tools and synthetic biology applications. With the aid of synthetic biology, production costs of chemicals, metabolites and food products are expected to decrease, by generating sustainable biochemical production of such resources. Also, such synthetic biological advances could be applied for medical purposes, as in pharmaceuticals and for biosensors. Recurrent, linked themes throughout the meeting were the shortage of resources, the world's transition into a bioeconomy, and how synthetic biology is helping tackle these issues through cutting-edge technologies. While there are still limitations in synthetic biology research, innovation is propelling the development of technology, the standardisation of synthetic biological tools and the use of suitable host organisms. These developments are laying a foundation to providing a future where cutting-edge research could generate potential solutions to society's pressing issues, thus incentivising a transition into a bioeconomy. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Hydrothermal synthetic strategies of inorganic semiconducting nanostructures.

    Science.gov (United States)

    Shi, Weidong; Song, Shuyan; Zhang, Hongjie

    2013-07-07

    Because of their unique chemical and physical properties, inorganic semiconducting nanostructures have gradually played a pivotal role in a variety of research fields, including electronics, chemical reactivity, energy conversion, and optics. A major feature of these nanostructures is the quantum confinement effect, which strongly depends on their size, shape, crystal structure and polydispersity. Among all developed synthetic methods, the hydrothermal method based on a water system has attracted more and more attention because of its outstanding advantages, such as high yield, simple manipulation, easy control, uniform products, lower air pollution, low energy consumption and so on. Precise control over the hydrothermal synthetic conditions is a key to the success of the preparation of high-quality inorganic semiconducting nanostructures. In this review, only the representative hydrothermal synthetic strategies of inorganic semiconducting nanostructures are selected and discussed. We will introduce the four types of strategies based on exterior reaction system adjustment, namely organic additive- and template-free hydrothermal synthesis, organic additive-assisted hydrothermal synthesis, template-assisted hydrothermal synthesis and substrate-assisted hydrothermal synthesis. In addition, the two strategies based on exterior reaction environment adjustment, including microwave-assisted and magnetic field-assisted hydrothermal synthesis, will be also described. Finally, we conclude and give the future prospects of this research area.

  12. LEVELS OF SYNTHETIC MUSKS COMPOUNDS IN AQUATIC ...

    Science.gov (United States)

    Synthetic musk compounds are consumer chemicals manufactured as fragrance materials Due to their high worldwide usage and release, they frequently occur in the aquatic and marine environments. The U.S. EPA (ORD, Las Vegas) developed surface-water monitoring methodology and conducted a one-year monthly monitoring of synthetic musks in water and biota from Lake Mead (Nevada) as well as from combined sewage effluent streams feeding Lake Mead. Presented are the overview of the chemistry, the monitoring methodology, and the significance of synthetic musk compounds in the aquatic environment. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than p

  13. Synthetic biology approaches to fluorinated polyketides.

    Science.gov (United States)

    Thuronyi, Benjamin W; Chang, Michelle C Y

    2015-03-17

    The catalytic diversity of living systems offers a broad range of opportunities for developing new methods to produce small molecule targets such as fuels, materials, and pharmaceuticals. In addition to providing cost-effective and renewable methods for large-scale commercial processes, the exploration of the unusual chemical phenotypes found in living organisms can also enable the expansion of chemical space for discovery of novel function by combining orthogonal attributes from both synthetic and biological chemistry. In this context, we have focused on the development of new fluorine chemistry using synthetic biology approaches. While fluorine has become an important feature in compounds of synthetic origin, the scope of biological fluorine chemistry in living systems is limited, with fewer than 20 organofluorine natural products identified to date. In order to expand the diversity of biosynthetically accessible organofluorines, we have begun to develop methods for the site-selective introduction of fluorine into complex natural products by engineering biosynthetic machinery to incorporate fluorinated building blocks. To gain insight into how both enzyme active sites and metabolic pathways can be evolved to manage and select for fluorinated compounds, we have studied one of the only characterized natural hosts for organofluorine biosynthesis, the soil microbe Streptomyces cattleya. This information provides a template for designing engineered organofluorine enzymes, pathways, and hosts and has allowed us to initiate construction of enzymatic and cellular pathways for the production of fluorinated polyketides.

  14. Cfd modeling of a synthetic jet actuator

    International Nuclear Information System (INIS)

    Dghim, Marouane; Ben Chiekh, Maher; Ben Nasrallah, Sassi

    2009-01-01

    Synthetic jet actuators show good promise as an enabling technology for innovative boundary layer flow control applied to external surfaces, like airplane wings, and to internal flows, like those occurring in a curved engine inlet. The appealing characteristics of a synthetic jet are zero-net-mass flux operation and an efficient control effect that takes advantages of unsteady fluid phenomena. The formation of a synthetic jet in a quiescent external air flow is only beginning to be understood and a rational understanding of these devices is necessary before they can be applied to the control of flows outside of the laboratory. The synthetic jet flow generated by a planar orifice is investigated here using computational approach. Computations of the 2D synthetic jet are performed with unsteady RANS modeled with the Realizable κ - ε turbulence model available in FLUENT environment. In this present work, the ability of the first order turbulence model, employed in our computations, to model the formation of the counter-rotating-vortex pair (CVP) that appears in the flow-field was investigated. Computational results were in good agreement with experimental measurements. The effectiveness of such control actuator was tested on separated boundary layer. Preliminary investigation were presented and discussed

  15. RESULTS OF A DATING ATTEMPT -CHEMICAL AND PHYSICAL MEASUREMENTS RELEVANT TO THE CASE OF THE CRETACEOUS TERTIARY EXTINCTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Asaro, Frank; Michel, Helen V.; Alvarez, Luis W.; Alvarez, Walter

    1980-09-01

    In Gubbio, Italy, a l em layer of clay between extensive limestone formations marks the boundary between the Cretaceous and Tertiary Periods. This clay layer was known to have been deposited about 65 million years ago when many life forms became extinct, but the length of time associated with the deposition was not known. In an attempt to measure this time with normally deposited meteoritic material as a clock, extensive measurements of iridium abundances (and those of many other elements) were made on the Gubbio rocks. Neutron activation analysis was the principal tool used in these studies. About 50 elements are searched for in materials like the earth's crust, about 40 are detected and about 30 are measured with useful precision. We were not able to determine exactly how long the clay deposition took. Instead the laboratory studies on the chemical and physical nature of the Cretaceous-Tertiary boundary led to the theory that an asteroid collision with the earth was responsible for the extinction of many forms of life including the dinosaurs.

  16. Influence of the chemical shift artifact on measurements of compact bone thickness in equine distal limb MR images.

    Science.gov (United States)

    Dimock, Abigail N; Spriet, Mathieu

    2010-01-01

    The effect of the chemical shift artifact, resulting from misregistration or phase cancellation at the interface between compact and trabecular bone, on apparent bone thickness was quantified in six isolated equine limbs. Sagittal T1-weighted spin echo (SE) and in-phase three-dimensional spoiled gradient echo (SPGR) images were acquired twice with a 1.5 T magnetic resonance (MR) unit, switching the frequency encoding direction between acquisitions. Out-of-phase SPGR images were also obtained. MR images with different frequency encoding directions were compared with each other and to radiographs made from corresponding 3-mm-bone sections. Compact bone thickness was significantly different when comparing images acquired with different frequency encoding directions for both SE and SPGR sequences. Significant differences were identified in the frequency but not the phase encoding direction when measurements of compact bone in MR images were compared with measurements obtained from thin section radiographs for the majority of surfaces studied (P 0.05). Measurements of compact bone from out-of-phase SPGR sequences were significantly different than from in-phase sequences (P echo sequences.

  17. Airborne hydrogen cyanide measurements using a chemical ionisation mass spectrometer for the plume identification of biomass burning forest fires

    Directory of Open Access Journals (Sweden)

    M. Le Breton

    2013-09-01

    Full Text Available A chemical ionisation mass spectrometer (CIMS was developed for measuring hydrogen cyanide (HCN from biomass burning events in Canada using I− reagent ions on board the FAAM BAe-146 research aircraft during the BORTAS campaign in 2011. The ionisation scheme enabled highly sensitive measurements at 1 Hz frequency through biomass burning plumes in the troposphere. A strong correlation between the HCN, carbon monoxide (CO and acetonitrile (CH3CN was observed, indicating the potential of HCN as a biomass burning (BB marker. A plume was defined as being 6 standard deviations above background for the flights. This method was compared with a number of alternative plume-defining techniques employing CO and CH3CN measurements. The 6-sigma technique produced the highest R2 values for correlations with CO. A normalised excess mixing ratio (NEMR of 3.68 ± 0.149 pptv ppbv−1 was calculated, which is within the range quoted in previous research (Hornbrook et al., 2011. The global tropospheric model STOCHEM-CRI incorporated both the observed ratio and extreme ratios derived from other studies to generate global emission totals of HCN via biomass burning. Using the ratio derived from this work, the emission total for HCN from BB was 0.92 Tg (N yr−1.

  18. Measurements of atmospheric carbonyl sulfide during the NASA Chemical Instrumentation Test and Evaluation Project: Implications for the global COS budget

    Science.gov (United States)

    Johnson, James E.; Bandy, Alan R.; Thornton, Donald C.; Bates, Timothy S.

    1993-01-01

    Atmospheric carbonyl sulfide COS concentrations were measured by three analytical systems during the Chemical Instrumentation Test and Evaluation (CITE 3) project. The three systems all used cryogenic sample preconcentration and gas chromatographic (GC) separation but differed in the method of detection. The FPD system used a flame photometric detector, the MS system used a mass selective detector, and the ECD-S system used a fluorinating catalyst followed by an electron capture detector. With the FPD system, we found a mean COS concentration of 510 ppt over the North Atlantic and 442 ppt over the Tropical Atlantic. With the ECD-S system, we found a mean COS concentration of 489 ppt over the North Atlantic and 419 ppt over the Tropical Atlantic. All three systems registered a latitudinal gradient in atmospheric COS of between 1.6 and 2.0 ppt per degree of latitude, with increasing COS concentrations northward which was similar to the gradient measured by Bingemer et al. (1990). It is difficult to reconcile the measured latitudinal concentration gradient with present theories of the global COS budget since the largest sink of COS is thought to be a flux to land plants, most of which are in the northern hemisphere.

  19. Measurements of atmospheric carbonyl sulfide during the NASA Chemical Instrumentation Test and Evaluation Project: Implications for the global COS budget

    Science.gov (United States)

    Johnson, James E.; Bandy, Alan R.; Thornton, Donald C.; Bates, Timothy S.

    1993-12-01

    Atmospheric COS concentrations were measured by three analytical systems during the Chemical Instrumentation Test and Evaluation (CITE 3) project. The three systems all used cryogenic sample preconcentration and gas chromatographic (GC) separation but differed in the method of detection. The FPD system used a flame photometric detector, the MS system used a mass selective detector, and the ECD-S system used a fluorinating catalyst followed by an electron capture detector. With the FPD system, we found a mean COS concentration of 510 ppt over the North Atlantic and 442 ppt over the Tropical Atlantic. With the ECD-S system, we found a mean COS concentration of 489 ppt over the North Atlantic and 419 ppt over the Tropical Atlantic. All three systems registered a latitudinal gradient in atmospheric COS of between 1.6 and 2.0 ppt per degree of latitude, with increasing COS concentrations northward which was similar to the gradient measured by Bingemer et al. (1990). It is difficult to reconcile the measured latitudinal concentration gradient with present theories of the global COS budget since the largest sink of COS is thought to be a flux to land plants, most of which are in the northern hemisphere.

  20. Chemical Characterization and Single Scattering Albedo of Atmospheric Aerosols Measured at Amami-Oshima, Southwest Japan, During Spring Seasons

    Science.gov (United States)

    Tsuruta, H.; Yabuki, M.; Takamura, T.; Sudo, S.; Yonemura, S.; Shirasuna, Y.; Hirano, K.; Sera, K.; Maeda, T.; Hayasaka, T.; Nakajima, T.

    2008-12-01

    An intensive field program was performed to measure atmospheric aerosols at Amami-Oshima, a small island located at southwest Japan, in the spring season of 2001, 2003, and 2005 under the ACE-Asia, APEX and ABC-EAREX2005 projects. Chemical analysis of the fine and coarse aerosols was made for elemental carbon (EC) and organic carbon, water soluble ions, and trace elements. Single scattering albedo (SSA) of aerosols was independently estimated by two methods. The one (SSAc) is by chemical compositions assuming a half internal mixture between EC and non sea-salt sulfate, and the other (SSAo) is by optical measurements of scattering coefficient and absorption coefficient. The backward trajectory analysis showed that the aerosol concentrations in the air masses arrived at Amami, were much higher from the Asian Continent than from other regions, and two types of aerosol enhancement were observed. The one was caused by polluted air masses from the urban-industrial area of east-coast China, the other was by high mineral dusts due to large- scale dust storms in the desert regions of northwest China. The SSAc was in a range of 0.87-0.98, and in good agreement with the SSAo after some corrections for original scattering and absorption coefficients. The SSAc showed no significant difference between the air masses from the polluted area and the desert regions. The negative correlation between the SSAc and EC was divided into two groups depending on the concentration of non sea-salt sulfate, while the increase in mineral dusts did not show any correlation with the SSAc.

  1. Use of simple body measurements and allometry to predict the chemical growth and feed intake in pigs

    Directory of Open Access Journals (Sweden)

    Andrea Piva

    2010-01-01

    Full Text Available The paper provides a practical procedure to estimate the chemical composition of pigs, their compositional growth and the expected feed intake from measurements of body weight (BW and backfat thickness (P2 serially performed in vivo. A farm data set provided information on 920 individuals including BW, measured at 71 ± 4 (t1, 126 ± 5 (t2 and 184 ± 5 (t3 days of age, of P2 at t2 and t3, and of voluntary daily feed intake (FI, recorded over the period from t2 to t3 by automated IVOG feeders. Body lipid mass was estimated as L= (9.17 + 0.70*P2 *BW/100 and the other chemical constituents were predicted from fat free empty body mass using Gompertz growth functions and allometry. Using individual changes of body composition from age t2 to t3, energy requirements for maintenance and growth and the corresponding predicted feed intakes (PFI were estimated. Measured FI were analysed for the effects of month, batch (within month, BWt2, P2t2, average metabolic weight, average daily gain and variation of P2 from t2 to t3. The same model was run again replacing the direct simple body measurements (BW and P2 with the estimated values of PFI as source of variation. Results. The Gompertz estimates of mature protein mass (Pm, relative growth rate parameter (B and lipid to protein ratio at maturity were 43.5 ± 5.8 kg, 0.0116 ± 0.0011 d-1 and 1.81 ± 0.30, respectively. The current protein mass averaged 18.5 + 1.6 kg and the daily retentions of protein and lipid were 177 ± 21 and 239 ± 62 g/d, respectively. FI and PFI averaged 2.824 ± 0.448 and 2.814 ± 0.393 kg/d, respectively. In the ANOVA of the FI data, the replacement of direct body measurements by PFI did not change the proportion of variance explained (83% and the RSD (0.199 g/d. The two sets of residual feed intake values obtained from the two ANOVA were highly correlated (RSD = 0.043 kg/d; R2= 0.961. Agreement between predicted and determined feed intakes provided a reasonable guarantee to the

  2. Radionuclide, scintillation cocktail and chemical/color quench influence on discriminator setting in gross alpha/beta measurements by LSC.

    Science.gov (United States)

    Stojković, Ivana; Tenjović, Branislava; Nikolov, Jovana; Todorović, Nataša

    2015-06-01

    Gross alpha/beta measurements in drinking waters enable radiochemical composition analysis in environmental studies providing efficient screening method that can indicate whether water contains elevated levels of any radionuclide. Routine gross alpha/beta activity monitoring in drinking waters has been carried out for a few years in laboratory for low-level radioactivity measurements in Novi Sad according to ASTM method, performing measurements on liquid scintillation counter Quantulus 1220 which can simultaneously generate alpha/beta spectra of samples by Pulse Shape Analysis (PSA circuit). In this paper, PSA discriminator impact was investigated to ensure obtaining of accurate and reliable alpha/beta activities. One novelty of presented work is PSA parameter setup with two combinations of radionuclides ((241)Am, (226)Ra and (90)Sr/(90)Y) with varying activity concentrations. Performed experiments also make contribution to investigations on the manner in which chemical and color quench affect optimal PSA parameter setting and further on, their altogether influence on gross alpha/beta activity measurements. Nitromethane, 15.8 M nitric acid and water, as well as yellow and yellow-orange dye, were used as quenching agents in order to test PSA/interference factor behavior in the presence of quenchers with different quenching strengths. Variation of PSA setting in quenched samples with two different commercially available cocktails (Ultima Gold LLT and OptiPhase HiSafe 3) was also tested. Lastly, application i.e. assessment of obtained PSA-SQP(E) correlation on the obtained results of activity concentrations of few artesian well water samples and colored spiked samples, based on the measured SQP(E) value of samples, has been demonstrated. Copyright © 2015. Published by Elsevier Ltd.

  3. Synthetic cannabinoids revealing adrenoleukodystrophy.

    Science.gov (United States)

    Fellner, Avi; Benninger, Felix; Djaldetti, Ruth

    2016-02-01

    We report a 41-year-old man who presented with a first generalized tonic-clonic seizure after recent consumption of a synthetic cannabinoid. MRI showed extensive bilateral, mainly frontal, white matter lesions. Blood analysis for very long chain fatty acids was compatible with adrenoleukodystrophy, and a missense mutation in the ABCD1 gene confirmed the diagnosis. We hypothesize that cannabinoid use might have contributed to metabolic decompensation with subacute worsening of the underlying condition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. CASH vs. SYNTHETIC CDOs

    Directory of Open Access Journals (Sweden)

    Silviu Eduard Dinca

    2015-12-01

    Full Text Available During the past few years, in the recent post-crisis aftermath, global asset managers are constantly searching new ways to optimize their investment portfolios while financial and banking institutions around the world are exploring new alternatives to better secure their financing and refinancing demands altogether with the enhancement of their risk management capabilities. We will exhibit herewith a comparison between the true-sale and synthetic CDO securitizations as financial markets-based funding, investment and risks mitigation techniques, highlighting certain key structuring and implementation specifics on each of them.

  5. Long-term cloud condensation nuclei number concentration, particle number size distribution and chemical composition measurements at regionally representative observatories

    Science.gov (United States)

    Schmale, Julia; Henning, Silvia; Decesari, Stefano; Henzing, Bas; Keskinen, Helmi; Sellegri, Karine; Ovadnevaite, Jurgita; Pöhlker, Mira L.; Brito, Joel; Bougiatioti, Aikaterini; Kristensson, Adam; Kalivitis, Nikos; Stavroulas, Iasonas; Carbone, Samara; Jefferson, Anne; Park, Minsu; Schlag, Patrick; Iwamoto, Yoko; Aalto, Pasi; Äijälä, Mikko; Bukowiecki, Nicolas; Ehn, Mikael; Frank, Göran; Fröhlich, Roman; Frumau, Arnoud; Herrmann, Erik; Herrmann, Hartmut; Holzinger, Rupert; Kos, Gerard; Kulmala, Markku; Mihalopoulos, Nikolaos; Nenes, Athanasios; O'Dowd, Colin; Petäjä, Tuukka; Picard, David; Pöhlker, Christopher; Pöschl, Ulrich; Poulain, Laurent; Prévôt, André Stephan Henry; Swietlicki, Erik; Andreae, Meinrat O.; Artaxo, Paulo; Wiedensohler, Alfred; Ogren, John; Matsuki, Atsushi; Yum, Seong Soo; Stratmann, Frank; Baltensperger, Urs; Gysel, Martin

    2018-02-01

    Aerosol-cloud interactions (ACI) constitute the single largest uncertainty in anthropogenic radiative forcing. To reduce the uncertainties and gain more confidence in the simulation of ACI, models need to be evaluated against observations, in particular against measurements of cloud condensation nuclei (CCN). Here we present a data set - ready to be used for model validation - of long-term observations of CCN number concentrations, particle number size distributions and chemical composition from 12 sites on 3 continents. Studied environments include coastal background, rural background, alpine sites, remote forests and an urban surrounding. Expectedly, CCN characteristics are highly variable across site categories. However, they also vary within them, most strongly in the coastal background group, where CCN number concentrations can vary by up to a factor of 30 within one season. In terms of particle activation behaviour, most continental stations exhibit very similar activation ratios (relative to particles > 20 nm) across the range of 0.1 to 1.0 % supersaturation. At the coastal sites the transition from particles being CCN inactive to becoming CCN active occurs over a wider range of the supersaturation spectrum. Several stations show strong seasonal cycles of CCN number concentrations and particle number size distributions, e.g. at Barrow (Arctic haze in spring), at the alpine stations (stronger influence of polluted boundary layer air masses in summer), the rain forest (wet and dry season) or Finokalia (wildfire influence in autumn). The rural background and urban sites exhibit relatively little variability throughout the year, while short-term variability can be high especially at the urban site. The average hygroscopicity parameter, κ, calculated from the chemical composition of submicron particles was highest at the coastal site of Mace Head (0.6) and lowest at the rain forest station ATTO (0.2-0.3). We performed closure studies based on κ-Köhler theory

  6. Fusion as a source of synthetic fuels

    International Nuclear Information System (INIS)

    Powell, J.R.; Fillo, J.A.; Steinberg, M.

    1981-01-01

    In the near-term, coal derived synthetic fuels will be used; but in the long-term, resource depletion and environmental effects will mandate synthetic fuels from inexhaustible sources - fission, fusion, and solar. Of the three sources, fusion appears uniquely suited for the efficient production of hydrogen-based fuels, due to its ability to directly generate very high process temperatures (up to approx. 2000 0 C) for water splitting reactions. Fusion-based water splitting reactions include high temperature electrolysis (HTE) of steam, thermochemical cycles, hybrid electrochemical/thermochemical, and direct thermal decomposition. HTE appears to be the simplest and most efficient process with efficiencies of 50 to 70% (fusion to hydrogen chemical energy), depending on process conditions

  7. Steel desulphurization with synthetic slag

    Directory of Open Access Journals (Sweden)

    Heput, T.

    2007-02-01

    Full Text Available Generally speaking, sulphur is considered a harmful element for steel quality, reason why all the technological steps are being taken in order to eliminate it from the metal bath. This paper deals with the influence of the chemical composition, on the slag quantity and of the bath stirring condition upon the desulphurization process in the casting ladle by treatment with synthetic slag. The experiments were made at an open-hearth plant with the steel tapping in two ladles (the desulphurization was made with synthetic slag at one ladle while the other one was considered standard and at the electric steel plant and for the synthetic slag formation a mix was used, made, according to several receipts, of: lime (50-75%, fluorine (0-17%, bauxite (0-32% and aluminous slag (8-22%. The data were processed in the calculation programs EXCEL and MATLAB, which resulted in a series of correlations between the desulphurization degree and the chemical composition of the slag, respectively the slag quantity both for the charges bubbled with Argon and the unbubbled ones.

    En general, el azufre es considerado un elemento nocivo para la calidad del acero y, por eso, en la práctica, se toman todas las medidas de orden tecnológico para su eliminación del baño metálico. En este trabajo se analiza la influencia de la composición química, de la cantidad de escoria y del estado de agitación del baño sobre el proceso de desulfuración en la cuchara para fundir por tratamiento con escoria sintética. Los experimentos se han realizado en una acería evacuando el acero en dos ollas (en una cuchara se efectuó la desulfuración con escoria sintética y a la otra se consideró como patrón y en un acería eléctrica y para la formación de la escoria sintética se utilizó una mezcla producida según muchas recetas, formada por: cal (50-75%, fluorina (0-17%, bauxita (0-32% y escoria aluminosa (8-22%. Los datos han sido procesados en los programas de c

  8. Synthetic collective intelligence.

    Science.gov (United States)

    Solé, Ricard; Amor, Daniel R; Duran-Nebreda, Salva; Conde-Pueyo, Núria; Carbonell-Ballestero, Max; Montañez, Raúl

    2016-10-01

    Intelligent systems have emerged in our biosphere in different contexts and achieving different levels of complexity. The requirement of communication in a social context has been in all cases a determinant. The human brain, probably co-evolving with language, is an exceedingly successful example. Similarly, social insects complex collective decisions emerge from information exchanges between many agents. The difference is that such processing is obtained out of a limited individual cognitive power. Computational models and embodied versions using non-living systems, particularly involving robot swarms, have been used to explore the potentiality of collective intelligence. Here we suggest a novel approach to the problem grounded in the genetic engineering of unicellular systems, which can be modified in order to interact, store memories or adapt to external stimuli in collective ways. What we label as Synthetic Swarm Intelligence defines a parallel approach to the evolution of computation and swarm intelligence and allows to explore potential embodied scenarios for decision making at the microscale. Here, we consider several relevant examples of collective intelligence and their synthetic organism counterparts. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. What Are Synthetic Cannabinoids?

    Science.gov (United States)

    ... that they contain "natural" material taken from a variety of plants. However, the only parts of these products that are natural are the dried plant materials. Chemical tests show that the active, mind-altering ingredients are cannabinoid ...

  10. Exploratory Data Analysis of Synthetic Aperture Radar (SAR Measurements to Distinguish the Sea Surface Expressions of Naturally-Occurring Oil Seeps from Human-Related Oil Spills in Campeche Bay (Gulf of Mexico

    Directory of Open Access Journals (Sweden)

    Gustavo de Araújo Carvalho

    2017-12-01

    Full Text Available An Exploratory Data Analysis (EDA aims to use Synthetic Aperture Radar (SAR measurements for discriminating between two oil slick types observed on the sea surface: naturally-occurring oil seeps versus human-related oil spills—the use of satellite sensors for this task is poorly documented in scientific literature. A long-term RADARSAT dataset (2008–2012 is exploited to investigate oil slicks in Campeche Bay (Gulf of Mexico. Simple Classification Algorithms to distinguish the oil slick type are designed based on standard multivariate data analysis techniques. Various attributes of geometry, shape, and dimension that describe the oil slick Size Information are combined with SAR-derived backscatter coefficients—sigma-(σo, beta-(βo, and gamma-(γo naught. The combination of several of these characteristics is capable of distinguishing the oil slick type with ~70% of overall accuracy, however, the sole and simple use of two specific oil slick’s Size Information (i.e., area and perimeter is equally capable of distinguishing seeps from spills. The data mining exercise of our EDA promotes a novel idea bridging petroleum pollution and remote sensing research, thus paving the way to further investigate the satellite synoptic view to express geophysical differences between seeped and spilled oil observed on the sea surface for systematic use.

  11. Outdoor Synthetic Aperture Acoustic Ground Target Measurements

    Science.gov (United States)

    2010-04-19

    Dolphin Echolocation Clicks For Target Discrimination,” The Journal Of The Acoustical Society Of America 124(1), 657-666 (2008). [20] Y. Nakamura...22] H. Uberall, "History Of Resonance Scattering Theory In Acoustics And Its Applications To Target Recognition." Proc. SPIE 1960, 350-361 (1993

  12. Portable digital lock-in instrument to determine chemical constituents with single-color absorption measurements for Global Health Initiatives

    Science.gov (United States)

    Vacas-Jacques, Paulino; Linnes, Jacqueline; Young, Anna; Gerrard, Victoria; Gomez-Marquez, Jose

    2014-03-01

    Innovations in international health require the use of state-of-the-art technology to enable clinical chemistry for diagnostics of bodily fluids. We propose the implementation of a portable and affordable lock-in amplifier-based instrument that employs digital technology to perform biochemical diagnostics on blood, urine, and other fluids. The digital instrument is composed of light source and optoelectronic sensor, lock-in detection electronics, microcontroller unit, and user interface components working with either power supply or batteries. The instrument performs lock-in detection provided that three conditions are met. First, the optoelectronic signal of interest needs be encoded in the envelope of an amplitude-modulated waveform. Second, the reference signal required in the demodulation channel has to be frequency and phase locked with respect to the optoelectronic carrier signal. Third, the reference signal should be conditioned appropriately. We present three approaches to condition the signal appropriately: high-pass filtering the reference signal, precise offset tuning the reference level by low-pass filtering, and by using a voltage divider network. We assess the performance of the lock-in instrument by comparing it to a benchmark device and by determining protein concentration with single-color absorption measurements. We validate the concentration values obtained with the proposed instrument using chemical concentration measurements. Finally, we demonstrate that accurate retrieval of phase information can be achieved by using the same instrument.

  13. Portable digital lock-in instrument to determine chemical constituents with single-color absorption measurements for Global Health Initiatives

    International Nuclear Information System (INIS)

    Vacas-Jacques, Paulino; Linnes, Jacqueline; Young, Anna; Gomez-Marquez, Jose; Gerrard, Victoria

    2014-01-01

    Innovations in international health require the use of state-of-the-art technology to enable clinical chemistry for diagnostics of bodily fluids. We propose the implementation of a portable and affordable lock-in amplifier-based instrument that employs digital technology to perform biochemical diagnostics on blood, urine, and other fluids. The digital instrument is composed of light source and optoelectronic sensor, lock-in detection electronics, microcontroller unit, and user interface components working with either power supply or batteries. The instrument performs lock-in detection provided that three conditions are met. First, the optoelectronic signal of interest needs be encoded in the envelope of an amplitude-modulated waveform. Second, the reference signal required in the demodulation channel has to be frequency and phase locked with respect to the optoelectronic carrier signal. Third, the reference signal should be conditioned appropriately. We present three approaches to condition the signal appropriately: high-pass filtering the reference signal, precise offset tuning the reference level by low-pass filtering, and by using a voltage divider network. We assess the performance of the lock-in instrument by comparing it to a benchmark device and by determining protein concentration with single-color absorption measurements. We validate the concentration values obtained with the proposed instrument using chemical concentration measurements. Finally, we demonstrate that accurate retrieval of phase information can be achieved by using the same instrument

  14. Noninvasive measurements of cardiac high-energy phosphate metabolites in dilated cardiomyopathy by using 31P spectroscopic chemical shift imaging

    International Nuclear Information System (INIS)

    Hansch, A.; Rzanny, R.; Heyne, J.-P.; Reichenbach, J.R.; Kaiser, W.A.; Leder, U.

    2005-01-01

    Dilated cardiomyopathy (DCM) is accompanied by an impaired cardiac energy metabolism. The aim of this study was to investigate metabolic ratios in patients with DCM compared to controls by using spectroscopic two-dimensional chemical shift imaging (2D-CSI). Twenty volunteers and 15 patients with severe symptoms (left ventricular ejection fraction, LVEF 30%) of DCM were investigated. Cardiac 31 P MR 2D-CSI measurements (voxel size: 40 x 40 x 100 mm 3 ) were performed with a 1.5 T whole-body scanner. Measurement time ranged from 15 min to 30 min. Peak areas and ratios of different metabolites were evaluated, including high-energy phosphates (PCr, ATP), 2,3-diphosphoglycerate (2,3-DPG) and phosphodiesters (PDE). In addition, we evaluated how PCr/ATP ratios correlate with LVEF as an established prognostic factor of heart failure. The PCr/γ-ATP ratio was significantly decreased in patients with moderate and severe DCM and showed a linear correlation with reduced LVEFs. PDE/ATP ratios were significantly increased only in patients with severe DCM as compared to volunteers. Applying 31 P MRS with commonly-available 2D-CSI sequences is a valuable technique to evaluate DCM by determining PCr/ATP ratios noninvasively. In addition to reduced PCr/ATP ratios observed in patients suffering from DCM, significantly-increased PDE/ATP ratios were found in patients with severe DCM. (orig.)

  15. Measurement of the cosmic ray spectrum and chemical composition in the 1015-1018 eV energy range

    Directory of Open Access Journals (Sweden)

    Chiavassa Andrea

    2018-01-01

    Full Text Available Cosmic ray in the 1015–1018 eV energy range can only be detected with ground based experiments, sampling Extensive Air Showers (EAS particles. The interest in this energetic interval is related to the search of the knee of the iron component of cosmic ray and to the study of the transition between galactic and extra-galactic primaries. The energy and mass calibration of these arrays can only be performed with complete EAS simulations as no sources are available for an absolute calibration. The systematic error on the energy assignment can be estimated around 30 ± 10%. The all particle spectrum measured in this energy range is more structured than previously thought, showing some faint features: a hardening slightly above 1016 eV and a steepening below 1017 eV. The studies of the primary chemical composition are quickly evolving towards the measurements of the primary spectra of different mass groups: up to now we are able to separate (on a event by event basis light and heavy primaries. Above the knee a steepening of the heavy primary spectrum and a hardening of the light ones have been detected.

  16. Measurement of chemical emissions under the influence of low-NO{sub x} combustion modifications. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Dismukes, E.B.

    1993-10-08

    Effect of low-NO{sub x} firing. There was no clear-cut effect on the emission of trace metals or acid gases. The data give marginal evidence for a decreased emission of Cr(VI), which would be a favorable change but is not certain by any means. The effect on aldehydes and ketones cannot be stated because of the loss of samples for baseline conditions; no credible data on these compounds were obtained for baseline conditions. The change in volatile organics appeared to be a reduction in emissions, whereas that for semi-volatiles seemed to be an increase. Inasmuch as low-NO{sub x} firing is sometimes accompanied by large increases in the amount of unburned carbon in the ash, the result for semi-volatiles is more in line with expectation. Effect of the hot-side ESP. As indicated above, the hot-side ESP lowered trace-element emissions to the range roughly from 1 to 5% of the levels found in the inlet gas stream. Not surprisingly, the hot-side ESP had no measurable influence on the emissions of SO{sub x}, HF, and HCl. Quite surprisingly, on the other hand, the ESP seemed to suppress the emission of certain organic substances. Suppression of the emission of formaldehyde is particularly difficult to explain. Presumably, the apparent disappearance of organics in the vapor state may be due in part to chemical changes at the high temperature of the ESP or in the corona regions, where ozone and other high-energy reactants are present. Perhaps chemical destruction was aided in the instance of semi-volatile compounds by relatively long residence times at high temperature while the compounds were adsorbed on ash particles in the hoppers. Effect of the cold-side ESP. Limited data with the cold-side ESP in operation made it difficult to detect any but the most emphatic effect of that ESP. No dramatic effect was seen.

  17. 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

  18. Synthetic biology for CO2fixation.

    Science.gov (United States)

    Gong, Fuyu; Cai, Zhen; Li, Yin

    2016-11-01

    Recycling of carbon dioxide (CO 2 ) into fuels and chemicals is a potential approach to reduce CO 2 emission and fossil-fuel consumption. Autotrophic microbes can utilize energy from light, hydrogen, or sulfur to assimilate atmospheric CO 2 into organic compounds at ambient temperature and pressure. This provides a feasible way for biological production of fuels and chemicals from CO 2 under normal conditions. Recently great progress has been made in this research area, and dozens of CO 2 -derived fuels and chemicals have been reported to be synthesized by autotrophic microbes. This is accompanied by investigations into natural CO 2 -fixation pathways and the rapid development of new technologies in synthetic biology. This review first summarizes the six natural CO 2 -fixation pathways reported to date, followed by an overview of recent progress in the design and engineering of CO 2 -fixation pathways as well as energy supply patterns using the concept and tools of synthetic biology. Finally, we will discuss future prospects in biological fixation of CO 2 .

  19. A synthetic zero air standard

    Science.gov (United States)

    Pearce, Ruth

    2016-04-01

    A Synthetic Zero Air Standard R. E. Hill-Pearce, K. V. Resner, D. R. Worton, P. J. Brewer The National Physical Laboratory Teddington, Middlesex TW11 0LW UK We present work towards providing traceability for measurements of high impact greenhouse gases identified by the World Meteorological Organisation (WMO) as critical for global monitoring. Standards for these components are required with challengingly low uncertainties to improve the quality assurance and control processes used for the global networks to better assess climate trends. Currently the WMO compatibility goals require reference standards with uncertainties of < 100 nmolmol-1 for CO2 (northern hemisphere) and < 2 nmolmol-1 for CH4 and CO. High purity zero gas is required for both the balance gas in the preparation of reference standards and for baseline calibrations of instrumentation. Quantification of the amount fraction of the target components in the zero gas is a significant contributor to the uncertainty and is challenging due to limited availability of reference standard at the amount fraction of the measurand and limited analytical techniques with sufficient detection limits. A novel dilutor was used to blend NPL Primary Reference Gas Mixtures containing CO2, CH4 and CO at atmospheric amount fractions with a zero gas under test. Several mixtures were generated with nominal dilution ratios ranging from 2000:1 to 350:1. The baseline of two cavity ring down spectrometers was calibrated using the zero gas under test after purification by oxidative removal of CO and hydrocarbons to < 1 nmolmol-1 (SAES PS15-GC50) followed by the removal of CO2 and water vapour to < 100 pmolmol-1 (SAES MC190). Using the standard addition method.[1] we have quantified the amount fraction of CO, CO2, and CH4 in scrubbed whole air (Scott Marrin) and NPL synthetic zero air. This is the first synthetic zero air standard with a matrix of N2, O2 and Ar closely matching ambient composition with gravimetrically assigned

  20. Life after the synthetic cell

    DEFF Research Database (Denmark)

    Rasmussen, Steen

    2010-01-01

    Nature asked eight synthetic-biology experts about the implications for science and society of the “synthetic cell” made by the J. Craig Venter Institute (JCVI). The institute's team assembled, modified and implanted a synthesized genome into a DNA-free bacterial shell to make a self-replicating ......Nature asked eight synthetic-biology experts about the implications for science and society of the “synthetic cell” made by the J. Craig Venter Institute (JCVI). The institute's team assembled, modified and implanted a synthesized genome into a DNA-free bacterial shell to make a self...

  1. Finding Hope in Synthetic Biology.

    Science.gov (United States)

    Takala, Tuija

    2017-04-01

    For some, synthetic biology represents great hope in offering possible solutions to many of the world's biggest problems, from hunger to sustainable development. Others remain fearful of the harmful uses, such as bioweapons, that synthetic biology can lend itself to, and most hold that issues of biosafety are of utmost importance. In this article, I will evaluate these points of view and conclude that although the biggest promises of synthetic biology are unlikely to become reality, and the probability of accidents is fairly substantial, synthetic biology could still be seen to benefit humanity by enhancing our ethical understanding and by offering a boost to world economy.

  2. Design Constraints on a Synthetic Metabolism

    Science.gov (United States)

    Bilgin, Tugce; Wagner, Andreas

    2012-01-01

    A metabolism is a complex network of chemical reactions that converts sources of energy and chemical elements into biomass and other molecules. To design a metabolism from scratch and to implement it in a synthetic genome is almost within technological reach. Ideally, a synthetic metabolism should be able to synthesize a desired spectrum of molecules at a high rate, from multiple different nutrients, while using few chemical reactions, and producing little or no waste. Not all of these properties are achievable simultaneously. We here use a recently developed technique to create random metabolic networks with pre-specified properties to quantify trade-offs between these and other properties. We find that for every additional molecule to be synthesized a network needs on average three additional reactions. For every additional carbon source to be utilized, it needs on average two additional reactions. Networks able to synthesize 20 biomass molecules from each of 20 alternative sole carbon sources need to have at least 260 reactions. This number increases to 518 reactions for networks that can synthesize more than 60 molecules from each of 80 carbon sources. The maximally achievable rate of biosynthesis decreases by approximately 5 percent for every additional molecule to be synthesized. Biochemically related molecules can be synthesized at higher rates, because their synthesis produces less waste. Overall, the variables we study can explain 87 percent of variation in network size and 84 percent of the variation in synthesis rate. The constraints we identify prescribe broad boundary conditions that can help to guide synthetic metabolism design. PMID:22768162

  3. Synthetic Aperture Compound Imaging

    DEFF Research Database (Denmark)

    Hansen, Jens Munk

    Medical ultrasound imaging is used for many purposes, e.g. for localizing and classifying cysts, lesions, and other processes. Almost any mass is first observed using B-mode imaging and later classified using e.g. color flow, strain, or attenuation imaging. It is therefore important that the B......, it is demonstrated through theoretical considerations that the compound effect achieved is close to a theoretical maximum for the amount of compounding attainable and using a -pitch convex array transducer, the first in-vivo images are created. The computational demands for an implementation are massive...... and the limiting factor is the amount of memory IO resources available. An equally high demand for memory throughput is found in the computer gaming industry, where a large part of the processing takes place on the graphics processing unit (GPU). Using the GPU, a framework for synthetic aperture imaging...

  4. Transionospheric synthetic aperture imaging

    CERN Document Server

    Gilman, Mikhail; Tsynkov, Semyon

    2017-01-01

    This landmark monograph presents the most recent mathematical developments in the analysis of ionospheric distortions of SAR images and offers innovative new strategies for their mitigation. As a prerequisite to addressing these topics, the book also discusses the radar ambiguity theory as it applies to synthetic aperture imaging and the propagation of radio waves through the ionospheric plasma, including the anisotropic and turbulent cases. In addition, it covers a host of related subjects, such as the mathematical modeling of extended radar targets (as opposed to point-wise targets) and the scattering of radio waves off those targets, as well as the theoretical analysis of the start-stop approximation, which is used routinely in SAR signal processing but often without proper justification. The mathematics in this volume is clean and rigorous – no assumptions are hidden or ambiguously stated. The resulting work is truly interdisciplinary, providing both a comprehensive and thorough exposition of the field,...

  5. Synthetic antibiofilm peptides.

    Science.gov (United States)

    de la Fuente-Núñez, César; Cardoso, Marlon Henrique; de Souza Cândido, Elizabete; Franco, Octavio Luiz; Hancock, Robert E W

    2016-05-01

    Bacteria predominantly exist as multicellular aggregates known as biofilms that are associated with at least two thirds of all infections and exhibit increased adaptive resistance to conventional antibiotic therapies. Therefore, biofilms are major contributors to the global health problem of antibiotic resistance, and novel approaches to counter them are urgently needed. Small molecules of the innate immune system called host defense peptides (HDPs) have emerged as promising templates for the design of potent, broad-spectrum antibiofilm agents. Here, we review recent developments in the new field of synthetic antibiofilm peptides, including mechanistic insights, synergistic interactions with available antibiotics, and their potential as novel antimicrobials against persistent infections caused by biofilms. This article is part of a Special Issue entitled: Antimicrobial peptides edited by Karl Lohner and Kai Hilpert. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Aerosol physical and chemical properties retrieved from ground-based remote sensing measurements during heavy haze days in Beijing winter

    Directory of Open Access Journals (Sweden)

    Z. Li

    2013-10-01

    Full Text Available With the increase in economic development over the past thirty years, many large cities in eastern and southwestern China are experiencing increased haze events and atmospheric pollution, causing significant impacts on the regional environment and even climate. However, knowledge on the aerosol physical and chemical properties in heavy haze conditions is still insufficient. In this study, two winter heavy haze events in Beijing that occurred in 2011 and 2012 were selected and investigated by using the ground-based remote sensing measurements. We used a CIMEL CE318 sun–sky radiometer to retrieve haze aerosol optical, physical and chemical properties, including aerosol optical depth (AOD, size distribution, complex refractive indices and aerosol fractions identified as black carbon (BC, brown carbon (BrC, mineral dust (DU, ammonium sulfate-like (AS components and aerosol water content (AW. The retrieval results from a total of five haze days showed that the aerosol loading and properties during the two winter haze events were comparable. Therefore, average heavy haze property parameters were drawn to present a research case for future studies. The average AOD is about 3.0 at 440 nm, and the Ångström exponent is 1.3 from 440 to 870 nm. The fine-mode AOD is 2.8 corresponding to a fine-mode fraction of 0.93. The coarse particles occupied a considerable volume fraction of the bimodal size distribution in winter haze events, with the mean particle radius of 0.21 and 2.9 μm for the fine and coarse modes respectively. The real part of the refractive indices exhibited a relatively flat spectral behavior with an average value of 1.48 from 440 to 1020 nm. The imaginary part showed spectral variation, with the value at 440 nm (about 0.013 higher than the other three wavelengths (about 0.008 at 675 nm. The aerosol composition retrieval results showed that volume fractions of BC, BrC, DU, AS and AW are 1, 2, 49, 15 and 33%, respectively, on average for

  7. Chemical ozone losses in Arctic and Antarctic polar winter/spring season derived from SCIAMACHY limb measurements 2002–2009

    Directory of Open Access Journals (Sweden)

    T. Sonkaew

    2013-02-01

    Full Text Available Stratospheric ozone profiles are retrieved for the period 2002–2009 from SCIAMACHY measurements of limb-scattered solar radiation in the Hartley and Chappuis absorption bands of ozone. This data set is used to determine the chemical ozone losses in both the Arctic and Antarctic polar vortices by averaging the ozone in the vortex at a given potential temperature. The chemical ozone losses at isentropic levels between 450 K and 600 K are derived from the difference between observed ozone abundances and the ozone modelled taking diabatic cooling into account, but no chemical ozone loss. Chemical ozone losses of up to 30–40% between mid-January and the end of March inside the Arctic polar vortex are reported. Strong inter-annual variability of the Arctic ozone loss is observed, with the cold winters 2004/2005 and 2006/2007 showing chemical ozone losses inside the polar vortex at 475 K, where 1.7 ppmv and 1.4 ppmv of ozone were removed, respectively, over the period from 22 January to beginning of April and 0.9 ppmv and 1.2 ppmv, respectively, during February. For the winters of 2007/2008 and 2002/2003, ozone losses of about 0.8 ppmv and 0.4 ppmv, respectively are estimated at the 475 K isentropic level for the period from 22 January to beginning of April. Essentially no ozone losses were diagnosed for the relatively warm winters of 2003/2004 and 2005/2006. The maximum ozone loss in the SCIAMACHY data set was found in 2007 at the 600 K level and amounted to about 2.1 ppmv for the period between 22 January and the end of April. Enhanced losses close to this altitude were found in all investigated Arctic springs, in contrast to Antarctic spring. The inter-annual variability of ozone losses and PSC occurrence rates observed during Arctic spring is consistent with the known QBO effects on the Arctic polar vortex, with exception of the unusual Arctic winter 2008/2009.

    The maximum total ozone mass loss of about 25 million tons was found in the

  8. Using a moving measurement platform for determining the chemical composition of atmospheric aerosols between Moscow and Vladivostok

    Directory of Open Access Journals (Sweden)

    S. Kuokka

    2007-09-01

    Full Text Available The TROICA-9 expedition (Trans-Siberian Observations Into the Chemistry of the Atmosphere was carried out at the Trans-Siberian railway between Moscow and Vladivostok in October 2005. Measurements of aerosol physical and chemical properties were made from an observatory carriage connected to a passenger train. Black carbon (BC concentrations in fine particles (PM2.5, aerodynamic diameter <2.5 μm were measured with an aethalometer using a five-minute time resolution. Concentrations of inorganic ions and some organic compounds (Cl, NO3, SO42−, Na+, NH4+, K+, Ca2+, Mg2+, oxalate and methane sulphonate were measured continuously by using an on-line system with a 15-min time resolution. In addition, particle volume size distributions were determined for particles in the diameter range 3–850 nm using a 10-min time resolution. The continuous measurements were completed with 24-h PM2.5 filter samples stored in a refrigerator and analyzed later in a chemical laboratory. The analyses included the mass concentrations of PM2.5, ions, monosaccharide anhydrides (levoglucosan, galactosan and mannosan and trace elements (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sb, V and Zn. The mass concentrations of PM2.5 varied in the range of 4.3–34.8 μg m−3 with an average of 21.6 μg m−3. Fine particle mass consisted mainly of BC (average 27.6%, SO42− (13.0%, NH4+ (4.1% and NO3 (1.4%. One of the major constituents was obviously organic carbon which was not determined. The contribution of BC was high compared with other studies made in Europe and Asia. High concentrations of ions, BC and particle volume were observed between Moscow and roughly 4000 km east of it, as well as close to Vladivostok

  9. Rewiring protein synthesis: From natural to synthetic amino acids.

    Science.gov (United States)

    Fan, Yongqiang; Evans, Christopher R; Ling, Jiqiang

    2017-11-01

    The protein synthesis machinery uses 22 natural amino acids as building blocks that faithfully decode the genetic information. Such fidelity is controlled at multiple steps and can be compromised in nature and in the laboratory to rewire protein synthesis with natural and synthetic amino acids. This review summarizes the major quality control mechanisms during protein synthesis, including aminoacyl-tRNA synthetases, elongation factors, and the ribosome. We will discuss evolution and engineering of such components that allow incorporation of natural and synthetic amino acids at positions that deviate from the standard genetic code. The protein synthesis machinery is highly selective, yet not fixed, for the correct amino acids that match the mRNA codons. Ambiguous translation of a codon with multiple amino acids or complete reassignment of a codon with a synthetic amino acid diversifies the proteome. Expanding the genetic code with synthetic amino acids through rewiring protein synthesis has broad applications in synthetic biology and chemical biology. Biochemical, structural, and genetic studies of the translational quality control mechanisms are not only crucial to understand the physiological role of translational fidelity and evolution of the genetic code, but also enable us to better design biological parts to expand the proteomes of synthetic organisms. This article is part of a Special Issue entitled "Biochemistry of Synthetic Biology - Recent Developments" Guest Editor: Dr. Ilka Heinemann and Dr. Patrick O'Donoghue. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Spotting a fake[Telling natural and synthetic diamonds apart

    Energy Technology Data Exchange (ETDEWEB)

    Lawson, S. [Diamond Trading Company, Maidenhead, Berkshire (United Kingdom)]. E-mail: simon.lawson@dtc.com

    2006-06-15

    Diamonds are highly prized for their dazzling appearance and hardness, but would you be able to spot one that had been created in the laboratory? Simon Lawson describes how physics-based techniques can distinguish between natural and synthetic stones. For the last 50 years or so we have been able to make synthetic diamonds that replicate the superlative physical and chemical properties of natural diamonds, and these are used largely for industrial applications. But in the mind of the consumer, there is far more to a diamond than its hardness or brilliance. Research commissioned by the Diamond Trading Company (DTC) has shown that 94% of women surveyed prefer natural diamonds over synthetic ones as a symbol of love, possibly as a result of the immense age of natural stones. One of the key research activities at the DTC is therefore to ensure that synthetic diamonds can be spotted easily. (U.K.)

  11. Biosynthesis of therapeutic natural products using synthetic biology.

    Science.gov (United States)

    Awan, Ali R; Shaw, William M; Ellis, Tom

    2016-10-01

    Natural products are a group of bioactive structurally diverse chemicals produced by microorganisms and plants. These molecules and their derivatives have contributed to over a third of the therapeutic drugs produced in the last century. However, over the last few decades traditional drug discovery pipelines from natural products have become far less productive and far more expensive. One recent development with promise to combat this trend is the application of synthetic biology to therapeutic natural product biosynthesis. Synthetic biology is a young discipline with roots in systems biology, genetic engineering, and metabolic engineering. In this review, we discuss the use of synthetic biology to engineer improved yields of existing therapeutic natural products. We further describe the use of synthetic biology to combine and express natural product biosynthetic genes in unprecedented ways, and how this holds promise for opening up completely new avenues for drug discovery and production. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Fate of Mercury in Synthetic Gypsum Used for Wallboard Production

    Energy Technology Data Exchange (ETDEWEB)

    Jessica Sanderson

    2007-12-31

    additional coal type. In the project, process stacks in the wallboard plant were sampled using the Ontario Hydro method. In every task, the stack locations sampled included a gypsum dryer and a gypsum calciner. In Tasks 1 and 4 through 7, the stack of the dryer for the wet wallboard product was also tested. Also at each site, in-stream process samples were collected and analyzed for mercury concentration before and after each significant step in wallboard production. These results and process data were used to construct mercury mass balances across the wallboard plants. The results from the project showed a wide range of percentage mercury losses from the synthetic gypsum feedstocks as measured by the Ontario Hydro method at the process stacks, ranging from 2% to 55% of the mercury in the gypsum feedstock. For the tasks exceeding 10% mercury loss across the wallboard plant, most of the loss occurred across the gypsum calciner. When total wallboard emissions remained below 10%, the primary emission location varied with a much less pronounced difference in emission between the gypsum dryer, calciner and board dryer. For all seven tasks, the majority of the mercury emissions were measured to be in the elemental form (Hg{sup 0}). Overall, the measured mercury loss mass rates ranged from 0.01 to 0.17 grams of mercury per dry ton of synthetic gypsum processed, or 0.01 to 0.4 pounds of mercury released per million square feet of wallboard produced from synthetic gypsum. The Coal Combustion Product Production and Use Survey from the American Coal Ash Association (ACAA) indicate that 7,579,187 short tons of synthetic gypsum were used for wallboard production in 2006. Extrapolating the results of this study to the ACAA industry usage rate, we estimate that mercury releases from wallboard production plants in 2006 ranged between 150 to 3000 pounds for the entire U.S. wallboard industry. With only seven sets of wallboard plant measurements, it is difficult to draw firm conclusions about

  13. Recoded organisms engineered to depend on synthetic amino acids.

    Science.gov (United States)

    Rovner, Alexis J; Haimovich, Adrian D; Katz, Spencer R; Li, Zhe; Grome, Michael W; Gassaway, Brandon M; Amiram, Miriam; Patel, Jaymin R; Gallagher, Ryan R; Rinehart, Jesse; Isaacs, Farren J

    2015-02-05

    Genetically modified organisms (GMOs) are increasingly used in research and industrial systems to produce high-value pharmaceuticals, fuels and chemicals. Genetic isolation and intrinsic biocontainment would provide essential biosafety measures to secure these closed systems and enable safe applications of GMOs in open systems, which include bioremediation and probiotics. Although safeguards have been designed to control cell growth by essential gene regulation, inducible toxin switches and engineered auxotrophies, these approaches are compromised by cross-feeding of essential metabolites, leaked expression of essential genes, or genetic mutations. Here we describe the construction of a series of genomically recoded organisms (GROs) whose growth is restricted by the expression of multiple essential genes that depend on exogenously supplied synthetic amino acids (sAAs). We introduced a Methanocaldococcus jannaschii tRNA:aminoacyl-tRNA synthetase pair into the chromosome of a GRO derived from Escherichia coli that lacks all TAG codons and release factor 1, endowing this organism with the orthogonal translational components to convert TAG into a dedicated sense codon for sAAs. Using multiplex automated genome engineering, we introduced in-frame TAG codons into 22 essential genes, linking their expression to the incorporation of synthetic phenylalanine-derived amino acids. Of the 60 sAA-dependent variants isolated, a notable strain harbouring three TAG codons in conserved functional residues of MurG, DnaA and SerS and containing targeted tRNA deletions maintained robust growth and exhibited undetectable escape frequencies upon culturing ∼10(11) cells on solid media for 7 days or in liquid media for 20 days. This is a significant improvement over existing biocontainment approaches. We constructed synthetic auxotrophs dependent on sAAs that were not rescued by cross-feeding in environmental growth assays. These auxotrophic GROs possess alternative genetic codes that

  14. Journal of Chemical Sciences

    Indian Academy of Sciences (India)

    0001195

    Synthetic scaffolds derived from hydrogels can be encoded with physical and chemical cues that provide the ... Syntheses, structures and properties of two coordination polymers of Cadmium(II) pseudohalide ... Two new coordination polymers of Cadmium(II) pseudohalide in combination with in situ generated bidentate ...

  15. Antitheilerial Chemical Drugs: A Review | Hayat | Bulletin of Animal ...

    African Journals Online (AJOL)

    Synthetic or semi synthetic chemical drugs were used for treatment of Theileria species. These drugs include antimalarial, trypanocides and antibiotics, antiviral, etc. The aim of this study was to over-view chemical drugs tested for treatment of theileriosis. Keywords: Theileria, treatment, chemical drug ...

  16. High Temperature, Radiation Hard Electronics Architecture for a Chemical Sensor Suite for Venus Atmospheric Measurements, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Makel Engineering, Inc. proposes to develop a high temperature, radiation hard electronics sensing architecture for a high temperature chemical sensor array suitable...

  17. Long-term cloud condensation nuclei number concentration, particle number size distribution and chemical composition measurements at regionally representative observatories

    Directory of Open Access Journals (Sweden)

    J. Schmale

    2018-02-01

    Full Text Available Aerosol–cloud interactions (ACI constitute the single largest uncertainty in anthropogenic radiative forcing. To reduce the uncertainties and gain more confidence in the simulation of ACI, models need to be evaluated against observations, in particular against measurements of cloud condensation nuclei (CCN. Here we present a data set – ready to be used for model validation – of long-term observations of CCN number concentrations, particle number size distributions and chemical composition from 12 sites on 3 continents. Studied environments include coastal background, rural background, alpine sites, remote forests and an urban surrounding. Expectedly, CCN characteristics are highly variable across site categories. However, they also vary within them, most strongly in the coastal background group, where CCN number concentrations can vary by up to a factor of 30 within one season. In terms of particle activation behaviour, most continental stations exhibit very similar activation ratios (relative to particles  > 20 nm across the range of 0.1 to 1.0 % supersaturation. At the coastal sites the transition from particles being CCN inactive to becoming CCN active occurs over a wider range of the supersaturation spectrum. Several stations show strong seasonal cycles of CCN number concentrations and particle number size distributions, e.g. at Barrow (Arctic haze in spring, at the alpine stations (stronger influence of polluted boundary layer air masses in summer, the rain forest (wet and dry season or Finokalia (wildfire influence in autumn. The rural background and urban sites exhibit relatively little variability throughout the year, while short-term variability can be high especially at the urban site. The average hygroscopicity parameter, κ, calculated from the chemical composition of submicron particles was highest at the coastal site of Mace Head (0.6 and lowest at the rain forest station ATTO (0.2–0.3. We performed closure

  18. Partial Least Squares Regression Calibration of an Ultraviolet-Visible Spectrophotometer for Measurements of Chemical Oxygen Demand in Dye Wastewater

    Science.gov (United States)

    Mai, W.; Zhang, J.-F.; Zhao, X.-M.; Li, Z.; Xu, Z.-W.

    2017-11-01

    Wastewater from the dye industry is typically analyzed using a standard method for measurement of chemical oxygen demand (COD) or by a single-wavelength spectroscopic method. To overcome the disadvantages of these methods, ultraviolet-visible (UV-Vis) spectroscopy was combined with principal component regression (PCR) and partial least squares regression (PLSR) in this study. Unlike the standard method, this method does not require digestion of the samples for preparation. Experiments showed that the PLSR model offered high prediction performance for COD, with a mean relative error of about 5% for two dyes. This error is similar to that obtained with the standard method. In this study, the precision of the PLSR model decreased with the number of dye compounds present. It is likely that multiple models will be required in reality, and the complexity of a COD monitoring system would be greatly reduced if the PLSR model is used because it can include several dyes. UV-Vis spectroscopy with PLSR successfully enhanced the performance of COD prediction for dye wastewater and showed good potential for application in on-line water quality monitoring.

  19. Compilation and analysis of types and concentrations of airborne chemicals measured in various indoor and outdoor human environments.

    Science.gov (United States)

    Cometto-Muñiz, J Enrique; Abraham, Michael H

    2015-05-01

    The main purpose of this article is to summarize and illustrate the results of a literature search on the types, levels, relative concentrations, concentration spread of individual chemicals, and number of airborne compounds (mostly volatile organic compounds, VOCs) that have been found, measured, and reported both indoors and outdoors. Two broad categories of indoor environments are considered: (1) home/school, and (2) commercial spaces. Also, two categories of outdoor environments are considered: (1) non-industrial and (2) industrial (the latter represented by the vicinity of a pig farm and the vicinity of an oil refinery). The outcome is presented as a series of graphs and tables containing the following statistics: geometric mean, arithmetic mean, median, standard deviation, variance, standard error, interquartile distance, minimum value, maximum value, and number of data (data count) for the air concentration of each reported compound in a given environment. A Supplementary Table allows interested readers to match each single value included in this compilation with its corresponding original reference. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Computational modeling of synthetic microbial biofilms.

    Science.gov (United States)

    Rudge, Timothy J; Steiner, Paul J; Phillips, Andrew; Haseloff, Jim

    2012-08-17

    Microbial biofilms are complex, self-organized communities of bacteria, which employ physiological cooperation and spatial organization to increase both their metabolic efficiency and their resistance to changes in their local environment. These properties make biofilms an attractive target for engineering, particularly for the production of chemicals such as pharmaceutical ingredients or biofuels, with the potential to significantly improve yields and lower maintenance costs. Biofilms are also a major cause of persistent infection, and a better understanding of their organization could lead to new strategies for their disruption. Despite this potential, the design of synthetic biofilms remains a major challenge, due to the complex interplay between transcriptional regulation, intercellular signaling, and cell biophysics. Computational modeling could help to address this challenge by predicting the behavior of synthetic biofilms prior to their construction; however, multiscale modeling has so far not been achieved for realistic cell numbers. This paper presents a computational method for modeling synthetic microbial biofilms, which combines three-dimensional biophysical models of individual cells with models of genetic regulation and intercellular signaling. The method is implemented as a software tool (CellModeller), which uses parallel Graphics Processing Unit architectures to scale to more than 30,000 cells, typical of a 100 μm diameter colony, in 30 min of computation time.

  1. Synthetic biology for pharmaceutical drug discovery

    Science.gov (United States)

    Trosset, Jean-Yves; Carbonell, Pablo

    2015-01-01

    Synthetic biology (SB) is an emerging discipline, which is slowly reorienting the field of drug discovery. For thousands of years, living organisms such as plants were the major source of human medicines. The difficulty in resynthesizing natural products, however, often turned pharmaceutical industries away from this rich source for human medicine. More recently, progress on transformation through genetic manipulation of biosynthetic units in microorganisms has opened the possibility of in-depth exploration of the large chemical space of natural products derivatives. Success of SB in drug synthesis culminated with the bioproduction of artemisinin by microorganisms, a tour de force in protein and metabolic engineering. Today, synthetic cells are not only used as biofactories but also used as cell-based screening platforms for both target-based and phenotypic-based approaches. Engineered genetic circuits in synthetic cells are also used to decipher disease mechanisms or drug mechanism of actions and to study cell–cell communication within bacteria consortia. This review presents latest developments of SB in the field of drug discovery, including some challenging issues such as drug resistance and drug toxicity. PMID:26673570

  2. Synthetic peptides for antibody production

    NARCIS (Netherlands)

    N.D. Zegers (Netty)

    1995-01-01

    textabstractSynthetic 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

  3. 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

  4. Imaging with Synthetic Aperture Radar

    CERN Document Server

    Massonnet, Didier

    2008-01-01

    Describing a field that has been transformed by the recent availability of data from a new generation of space and airborne systems, the authors offer a synthetic geometrical approach to the description of synthetic aperture radar, one that addresses physicists, radar specialists, as well as experts in image processing.  

  5. Synthetic biology of polyketide synthases

    DEFF Research Database (Denmark)

    Yuzawa, Satoshi; Backman, Tyler W.H.; Keasling, Jay D.

    2018-01-01

    ). The modules are composed of enzymatic domains that share sequence and functional similarity across all known PKSs. We have used the nomenclature of synthetic biology to classify the enzymatic domains and modules as parts and devices, respectively, and have generated detailed lists of both. In addition, we...... realize the potential that synthetic biology approaches bring to this class of molecules....

  6. Cheminformatic comparison of approved drugs from natural product versus synthetic origins.

    Science.gov (United States)

    Stratton, Christopher F; Newman, David J; Tan, Derek S

    2015-11-01

    Despite the recent decline of natural product discovery programs in the pharmaceutical industry, approximately half of all new drug approvals still trace their structural origins to a natural product. Herein, we use principal component analysis to compare the structural and physicochemical features of drugs from natural product-based versus completely synthetic origins that were approved between 1981 and 2010. Drugs based on natural product structures display greater chemical diversity and occupy larger regions of chemical space than drugs from completely synthetic origins. Notably, synthetic drugs based on natural product pharmacophores also exhibit lower hydrophobicity and greater stereochemical content than drugs from completely synthetic origins. These results illustrate that structural features found in natural products can be successfully incorporated into synthetic drugs, thereby increasing the chemical diversity available for small-molecule drug discovery. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Connecting synthetic chemistry decisions to cell and genome biology using small-molecule phenotypic profiling.

    Science.gov (United States)

    Wagner, Bridget K; Clemons, Paul A

    2009-12-01

    Discovering small-molecule modulators for thousands of gene products requires multiple stages of biological testing, specificity evaluation, and chemical optimization. Many cellular profiling methods, including cellular sensitivity, gene expression, and cellular imaging, have emerged as methods to assess the functional consequences of biological perturbations. Cellular profiling methods applied to small-molecule science provide opportunities to use complex phenotypic information to prioritize and optimize small-molecule structures simultaneously against multiple biological endpoints. As throughput increases and cost decreases for such technologies, we see an emerging paradigm of using more information earlier in probe-discovery and drug-discovery efforts. Moreover, increasing access to public datasets makes possible the construction of 'virtual' profiles of small-molecule performance, even when multiplexed measurements were not performed or when multidimensional profiling was not the original intent. We review some key conceptual advances in small-molecule phenotypic profiling, emphasizing connections to other information, such as protein-binding measurements, genetic perturbations, and cell states. We argue that to maximally leverage these measurements in probe-discovery and drug-discovery requires a fundamental connection to synthetic chemistry, allowing the consequences of synthetic decisions to be described in terms of changes in small-molecule profiles. Mining such data in the context of chemical structure and synthesis strategies can inform decisions about chemistry procurement and library development, leading to optimal small-molecule screening collections.

  8. New designer drugs (synthetic cannabinoids and synthetic cathinones): review of literature.

    Science.gov (United States)

    Cottencin, Olivier; Rolland, Benjamin; Karila, Laurent

    2014-01-01

    New designer drugs (synthetic cannabinoids and synthetic cathinones) are new "legal highs" that are sold online for recreational public or private use. Synthetic cannabinoids are psychoactive herbal and chemical products that mimic the effects of cannabis when used. These drugs are available on the Internet or in head shops as incense or air fresheners to circumvent the law. Cathinone is a naturally occurring beta-ketone amphetamine analog found in the leaves of the Catha edulis plant. Synthetic cathinones are phenylalkylamine derivatives that may possess amphetamine-like properties. These drugs are sold online as bath salts. Designer drugs are often labeled as "not for human consumption" to circumvent drug abuse legislation. The absence of legal risks, the ease of obtaining these drugs, the moderate cost, and the availability via the Internet are the main features that attract users, but the number of intoxicated people presenting with emergencies is increasing. There is evidence that negative health and social consequences may affect recreational and chronic users. The addictive potential of designer drugs is not negligible.

  9. A Low Temperature Synthetic Route to Nanocrystalline TiN

    African Journals Online (AJOL)

    NICO

    A simple chemical synthetic route has been developed to prepare nanocrystalline titanium nitride (TiN) in an autoclave, by the reaction of metallic Ti with NaNH2 at low temperature of 500–600 °C. The samples were characterized by X-ray powder diffraction, transmission electron microscopy, and X-ray photoelectron ...

  10. Biological activity and toxicitiy of imported and synthetic metal ...

    African Journals Online (AJOL)

    ... of green alga Scendesmus obliquus. The toxicity of surfactants to Scendesmus obliquus are arranged in the order: imported fluid > Synthetic fluid > S+ D > I+A> S+B> I+ C> I+B > I+D > I+D >S+A > I+4. These results prove that, the toxicity of fluids depends on its chemical structure. Egyptian Journal of Biotechnology Vol.

  11. The formulation of synthetic domestic wastewater sludge medium to ...

    African Journals Online (AJOL)

    on the chemical oxygen demand (COD) and the biological degradable organic matter (BOD) of domestic wastewater sludge. Four synthetic media ... anaerobic bioreactors that rely on sulphate-reducing bacteria. (SRB) (Garcia et al., ..... A, BLAZQUEZ ML and. GONZALEZ F (2001) Bioremediation of an industrial acid mine.

  12. Computing with synthetic protocells.

    Science.gov (United States)

    Courbet, Alexis; Molina, Franck; Amar, Patrick

    2015-09-01

    In this article we present a new kind of computing device that uses biochemical reactions networks as building blocks to implement logic gates. The architecture of a computing machine relies on these generic and composable building blocks, computation units, that can be used in multiple instances to perform complex boolean functions. Standard logical operations are implemented by biochemical networks, encapsulated and insulated within synthetic vesicles called protocells. These protocells are capable of exchanging energy and information with each other through transmembrane electron transfer. In the paradigm of computation we propose, protoputing, a machine can solve only one problem and therefore has to be built specifically. Thus, the programming phase in the standard computing paradigm is represented in our approach by the set of assembly instructions (specific attachments) that directs the wiring of the protocells that constitute the machine itself. To demonstrate the computing power of protocellular machines, we apply it to solve a NP-complete problem, known to be very demanding in computing power, the 3-SAT problem. We show how to program the assembly of a machine that can verify the satisfiability of a given boolean formula. Then we show how to use the massive parallelism of these machines to verify in less than 20 min all the valuations of the input variables and output a fluorescent signal when the formula is satisfiable or no signal at all otherwise.

  13. Endocrine potency of wastewater: Contents of endocrine disrupting chemicals and effects measured by in vivo and in vitro assays

    DEFF Research Database (Denmark)

    Kusk, Kresten Ole; Krüger, Tanja; Long, Manhai

    2011-01-01

    properties: phthalate metabolites, parabens, industrial phenols, ultraviolet screens, and natural and synthetic steroid estrogens. The endocrine disrupting bioactivity and toxicity of the extracts were analyzed in cell culture assay for the potency to affect the function of the estrogen, androgen, aryl...... of EDCs was reduced in the STPs but not eliminated, as verified by the applied bioassays that all responded to the extracts of effluent samples. Our data suggest that the wastewater treatment processes are not efficient enough to prevent contamination of environmental surface waters. © 2010 SETAC....

  14. Synthetic cannabinoid: prevalence, mechanisms of addiction development, mental disorders associated with the use of synthetic cannabinoid

    Directory of Open Access Journals (Sweden)

    Antsyborov A.V.

    2017-04-01

    Full Text Available according to the authors among the new psychoactive substances, the number of which is growing every year, despite the measures aimed at the obstacles to their dissemination there discovered the most frequent violations of psychotic conditions associated with use of synthetic cannabinoid in clinical practice. On the black market, they are distributed through online shops, under the guise of herbal mixtures for Smoking. When ingested, this group of drugs at the peak of intoxication raises a number of mental (different according to the depth of impaired consciousness, auditory and visual hallucinations, panic attacks, acute psychotic paranoid disorders, catatonic stupor, polar affective disorders, acute polythematic delusional symptoms and somatic disorders (disorders of heart rhythm and conduction, acute ischemic disorders, hypertension, depression of respiratory activity, violation of thermoregulation, development of acute renal failure, vomiting, expressed cephalgia, clinic of hypokalemia. In the reviewed literature and authors own observations there have been discovered some cases of mental addiction development to synthetic cannabinoids. The analysis of new literature data and own clinical observations helped the authors to compare the psychotropic effects caused by this group of drugs, relative to other known surfactants. The toxic effects of CSC on the body greatly exceeds the use of plant cannabinoids, and it has almost the same effects as the synthetic cathinone’s. The speed of formation of psychological dependence is lower compared to synthetic cathinone. Developing current strategies for diagnosis, treatment, and rehabilitation of patients who use synthetic cannabinoids remains an important task for practical healthcare.

  15. Online measurement of biogenic organic acids in the boreal forest using atmospheric pressure chemical ionization mass spectrometry (APCI-MS)

    Science.gov (United States)

    Vogel, A. L.; Brüggemann, M.; ńijälä, M.; Ehn, M.; Junninen, H.; Corrigan, A. L.; Petäjä, T.; Worsnop, D. R.; Russell, L. M.; Kulmala, M.; Williams, J.; Hoffmann, T.

    2012-04-01

    Emission of biogenic volatile organic compounds (BVOCs) by vegetation in the boreal forest and their subsequent atmospheric oxidation leads to the formation of secondary organic aerosol (SOA) which has important impacts on climate and human health. Oxidation of BVOCs produces a variety of mostly unidentified species in oxygenated organic aerosol (OOA). Presently aerosol mass spectrometers (AMS) are able to determine quantitative information about the relative oxygen to carbon content of organic aerosols and thereby reveal the photochemical age and volatility of organic aerosol by distinguishing between low volatile oxygenated organic aerosol (LV-OOA), semivolatile oxygenated organic aerosol (SV-OOA) and hydrocarbon like organic aerosol (HOA)[1]. However, the AMS can usually not be used to measure and quantify single organic compounds such as individual biogenic organic marker compounds. Here we show the results of online measurements of gas and particle phase biogenic acids during HUMPPA-COPEC 2010 at Hyytiälä, Finland. This was achieved by coupling a self built miniature Versatile Aerosol Concentration Enrichment System (mVACES) as described by Geller et al. [2] with an Atmospheric Pressure Chemical Ionization Ion Trap Mass Spectrometer (APCI IT MS; Hoffmann et al., [3]). The benefits of the on-line APCI-MS are soft ionization with little fragmentation compared to AMS, high measurement frequency and less sampling artifacts than in the common procedure of taking filter samples, extraction and detection with LC-MS. Furthermore, the ion trap of the instrument allows MS/MS experiments to be performed by isolation of single m/z ratios of selected molecular species. By subsequent addition of energy, the trapped ions form characteristic fragments which enable structural insight on the molecular level. Comparison of APCI-MS data to AMS data, acquired with a C-ToF-AMS [4], revealed a good correlation coefficient for total organics and sulphate. Furthermore, data show

  16. Estimation of Corn Yield and Soil Nitrogen via Soil Electrical Conductivity Measurement Treated with Organic, Chemical and Biological Fertilizers

    Directory of Open Access Journals (Sweden)

    H. Khalilzade

    2016-02-01

    Full Text Available Introduction Around the world maize is the second crop with the most cultivated areas and amount of production, so as the most important strategic crop, have a special situation in policies, decision making, resources and inputs allocation. On the other side, negative environmental consequences of intensive consumption of agrochemicals resulted to change view concerning food production. One of the most important visions is sustainable production of enough food plus attention to social, economic and environmental aspects. Many researchers stated that the first step to achieve this goal is optimization and improvement of resources use efficiencies. According to little knowledge on relation between soil electrical conductivity and yield of maize, beside the environmental concerns about nitrogen consumption and need to replace chemical nitrogen by ecological inputs, this study designed and aimed to evaluate agroecological characteristics of corn and some soil characteristics as affected by application of organic and biological fertilizers under field conditions. Materials and Methods In order to probing the possibility of grain yield and soil nitrogen estimation via measurement of soil properties, a field experiment was conducted during growing season 2010 at Research Station, Ferdowsi University of Mashhad, Iran. A randomized complete block design (RCBD with three replications was used. Treatments included: 1- manure (30 ton ha-1, 2-vermicompost (10 ton ha-1, 3- nitroxin (containing Azotobacter sp. and Azospirillum sp., inoculation was done according to Kennedy et al., 4- nitrogen as urea (400 kg ha-1 and 5- control (without fertilizer. Studied traits were soil pH, soil EC, soil respiration rate, N content of soil and maize yield. Soil respiration rate was measured using equation 1: CO2= (V0- V× N×22 Equation 1 In which V0 is the volume of consumed acid for control treatment titration, V is of the volume of consumed acid for sample treatment

  17. New insight into PM2.5pollution patterns in Beijing based on one-year measurement of chemical compositions.

    Science.gov (United States)

    Tan, Tianyi; Hu, Min; Li, Mengren; Guo, Qingfeng; Wu, Yusheng; Fang, Xin; Gu, Fangting; Wang, Yu; Wu, Zhijun

    2018-04-15

    In recent years, air pollution has become a major concern in China, especially in the capital city of Beijing. Haze events occur in Beijing over all four seasons, exhibiting distinct characteristics. In this study, the typical evolution patterns of atmospheric particulate matter with a diameter of less than 2.5μm (PM 2.5 ) in each season were illustrated by episode-based analysis. In addition, a novel method was developed to elucidate the driving species of pollution, which is the largest contributor to the incremental PM 2.5 (ΔPM 2.5 ), not PM 2.5 . This method revealed a temporal variation of the driving species throughout the year: nitrate-driven spring, sulfate-driven summer, nitrate-driven early fall, and organic matters (OM)-driven late fall and winter. These results suggested that primary organic particles or volatile organic compounds emissions were dominant in the heating season due to residential heating, while NOx and SO 2 emissions dominated in the other seasons. Besides, nitrate formation seemed more significant than sulfate formation during severe pollution episodes. It was also found that the pollution formation mechanism in the winter showed some unique features in comparison with the other seasons: aqueous reactions were more important in the winter, while multiple pathways coexisted in the other seasons. Furthermore, this study confirmed that the PM 2.5 in Beijing was moderately acidic despite a fully neutralized system. In addition, the acidity variation during pollution episodes displayed different patterns between seasons and was driven by both the variation of aerosol water and chemical compositions. These results provide a new perspective to understand the characteristics and mechanisms of aerosol pollution in Beijing. However, more accurate measurements are necessary for effective air pollution control that depends on the seasonal variation of fine particle formation in Beijing and the surrounding areas. Copyright © 2017 Elsevier B.V. All

  18. Spicing things up: synthetic cannabinoids.

    Science.gov (United States)

    Spaderna, Max; Addy, Peter H; D'Souza, Deepak Cyril

    2013-08-01

    Recently, products containing synthetic cannabinoids, collectively referred to as Spice, are increasingly being used recreationally. The availability, acute subjective effects-including self-reports posted on Erowid-laboratory detection, addictive potential, and regulatory challenges of the Spice phenomenon are reviewed. Spice is sold under the guise of potpourri or incense. Unlike delta-9-tetrahydrocannabinol, the synthetic cannabinoids present in Spice are high-potency, high-efficacy, cannabinoid receptor full agonists. Since standard urine toxicology does not test for the synthetic cannabinoids in Spice, it is often used by those who want to avoid detection of drug use. These compounds have not yet been subjected to rigorous testing in humans. Acute psychoactive effects include changes in mood, anxiety, perception, thinking, memory, and attention. Adverse effects include anxiety, agitation, panic, dysphoria, psychosis, and bizarre behavior. Psychosis outcomes associated with Spice provide additional data linking cannabinoids and psychosis. Adverse events necessitating intervention by Poison Control Centers, law enforcement, emergency responders, and hospitals are increasing. Despite statutes prohibiting the manufacture, distribution, and sale of Spice products, manufacturers are replacing banned compounds with newer synthetic cannabinoids that are not banned. There is an urgent need for better research on the effects of synthetic cannabinoids to help clinicians manage adverse events and to better understand cannabinoid pharmacology in humans. The reported psychosis outcomes associated with synthetic cannabinoids contribute to the ongoing debate on the association between cannabinoids and psychosis. Finally, drug detection tests for synthetic cannabinoids need to become clinically available.

  19. Phase I Focused Corrective Measures Study/Feasibility Study for the L-Area Oil and Chemical Basin (904-83G)

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, E. [Westinghouse Savannah River Company, AIKEN, SC (United States)

    1997-02-01

    This report presents the completed Resource Conservation and Recovery Act (RCRA) Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Focused Corrective Measures Study/Feasibility Study (CMS/FS) for the L-Area Oil and Chemical Basin (LAOCB)/L-Area Acid Caustic Basin (9LAACB) Solid Waste Management Unit/Operable Unit (SWMU/OU) at the Savannah River Site (SRS).

  20. Bistatic synthetic aperture radar

    Science.gov (United States)

    Yates, Gillian

    Synthetic aperture radar (SAR) allows all-weather, day and night, surface surveillance and has the ability to detect, classify and geolocate objects at long stand-off ranges. Bistatic SAR, where the transmitter and the receiver are on separate platforms, is seen as a potential means of countering the vulnerability of conventional monostatic SAR to electronic countermeasures, particularly directional jamming, and avoiding physical attack of the imaging platform. As the receiving platform can be totally passive, it does not advertise its position by RF emissions. The transmitter is not susceptible to jamming and can, for example, operate at long stand-off ranges to reduce its vulnerability to physical attack. This thesis examines some of the complications involved in producing high-resolution bistatic SAR imagery. The effect of bistatic operation on resolution is examined from a theoretical viewpoint and analytical expressions for resolution are developed. These expressions are verified by simulation work using a simple 'point by point' processor. This work is extended to look at using modern practical processing engines for bistatic geometries. Adaptations of the polar format algorithm and range migration algorithm are considered. The principal achievement of this work is a fully airborne demonstration of bistatic SAR. The route taken in reaching this is given, along with some results. The bistatic SAR imagery is analysed and compared to the monostatic imagery collected at the same time. Demonstrating high-resolution bistatic SAR imagery using two airborne platforms represents what I believe to be a European first and is likely to be the first time that this has been achieved outside the US (the UK has very little insight into US work on this topic). Bistatic target characteristics are examined through the use of simulations. This also compares bistatic imagery with monostatic and gives further insight into the utility of bistatic SAR.

  1. Synthetic biology for therapeutic applications.

    Science.gov (United States)

    Abil, Zhanar; Xiong, Xiong; Zhao, Huimin

    2015-02-02

    Synthetic biology is a relatively new field with the key aim of designing and constructing biological systems with novel functionalities. Today, synthetic biology devices are making their first steps in contributing new solutions to a number of biomedical challenges, such as emerging bacterial antibiotic resistance and cancer therapy. This review discusses some synthetic biology approaches and applications that were recently used in disease mechanism investigation and disease modeling, drug discovery and production, as well as vaccine development and treatment of infectious diseases, cancer, and metabolic disorders.

  2. The Ethics of Synthetic Biology

    DEFF Research Database (Denmark)

    Christiansen, Andreas

    The dissertation analyses and discusses a number of ethical issues that have been raised in connection with the development of synthetic biology. Synthetic biology is a set of new techniques for DNA-level design and construction of living beings with useful properties. The dissertation especially......) popular responsesto them succeed, and whether the objections are ultimately persuasive.2. Given that synthetic biology is a new technology, there is a certain degree of uncertainty about its ultimate effects, and many perceive the technology as risky. I discuss two common approaches in risk regulation...

  3. MISTRAL: A game-theoretical model to allocate security measures in a multi-modal chemical transportation network with adaptive adversaries

    International Nuclear Information System (INIS)

    Talarico, Luca; Reniers, Genserik; Sörensen, Kenneth; Springael, Johan

    2015-01-01

    In this paper we present a multi-modal security-transportation model to allocate security resources within a chemical supply chain which is characterized by the use of different transport modes, each having their own security features. We consider security-related risks so as to take measures against terrorist acts which could target critical transportation systems. The idea of addressing security-related issues, by supporting decisions for preventing or mitigating intentional acts on transportation infrastructure, has gained attention in academic research only recently. The decision model presented in this paper is based on game theory and it can be employed to organize intelligence capabilities aimed at securing chemical supply chains. It enables detection and warning against impending attacks on transportation infrastructures and the subsequent adoption of security countermeasures. This is of extreme importance for preventing terrorist attacks and for avoiding (possibly huge) human and economic losses. In our work we also provide data sources and numerical simulations by applying the proposed model to a illustrative multi-modal chemical supply chain. - Highlights: • A model to increase the security in a multimodal chemical supply chain is proposed. • The model considers adaptive opponents having multi-attribute utility functions. • The model is based on game theory using an attacker–defender schema. • The model provides recommendations about where to allocate security measures. • Numerical simulations on a sample multimodal chemical supply chain are shown

  4. Yeast synthetic biology toolbox and applications for biofuel production.

    Science.gov (United States)

    Tsai, Ching-Sung; Kwak, Suryang; Turner, Timothy L; Jin, Yong-Su

    2015-02-01

    Yeasts are efficient biofuel producers with numerous advantages outcompeting bacterial counterparts. While most synthetic biology tools have been developed and customized for bacteria especially for Escherichia coli, yeast synthetic biological tools have been exploited for improving yeast to produce fuels and chemicals from renewable biomass. Here we review the current status of synthetic biological tools and their applications for biofuel production, focusing on the model strain Saccharomyces cerevisiae We describe assembly techniques that have been developed for constructing genes, pathways, and genomes in yeast. Moreover, we discuss synthetic parts for allowing precise control of gene expression at both transcriptional and translational levels. Applications of these synthetic biological approaches have led to identification of effective gene targets that are responsible for desirable traits, such as cellulosic sugar utilization, advanced biofuel production, and enhanced tolerance against toxic products for biofuel production from renewable biomass. Although an array of synthetic biology tools and devices are available, we observed some gaps existing in tool development to achieve industrial utilization. Looking forward, future tool development should focus on industrial cultivation conditions utilizing industrial strains. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

  5. Clinical validation of synthetic brain MRI in children: initial experience

    Energy Technology Data Exchange (ETDEWEB)

    West, Hollie; Leach, James L.; Jones, Blaise V.; Care, Marguerite; Radhakrishnan, Rupa; Merrow, Arnold C.; Alvarado, Enrique; Serai, Suraj D. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

    2017-01-15

    The purpose of this study was to determine the diagnostic accuracy of synthetic MR sequences generated through post-acquisition processing of a single sequence measuring inherent R1, R2, and PD tissue properties compared with sequences acquired conventionally as part of a routine clinical pediatric brain MR exam. Thirty-two patients underwent routine clinical brain MRI with conventional and synthetic sequences acquired (22 abnormal). Synthetic axial T1, T2, and T2 fluid attenuation inversion recovery or proton density-weighted sequences were made to match the comparable clinical sequences. Two exams for each patient were de-identified. Four blinded reviewers reviewed eight patients and were asked to generate clinical reports on each exam (synthetic or conventional) at two different time points separated by a mean of 33 days. Exams were rated for overall and specific finding agreement (synthetic/conventional and compared to gold standard consensus review by two senior reviewers with knowledge of clinical report), quality, and diagnostic confidence. Overall agreement between conventional and synthetic exams was 97%. Agreement with consensus readings was 84% (conventional) and 81% (synthetic), p = 0.61. There were no significant differences in sensitivity, specificity, or accuracy for specific imaging findings involving the ventricles, CSF, brain parenchyma, or vasculature between synthetic or conventional exams (p > 0.05). No significant difference in exam quality, diagnostic confidence, or noise/artifacts was noted comparing studies with synthetic or conventional sequences. Diagnostic accuracy and quality of synthetically generated sequences are comparable to conventionally acquired sequences as part of a standard pediatric brain exam. Further confirmation in a larger study is warranted. (orig.)

  6. Tissue Harmonic Synthetic Aperture Imaging

    DEFF Research Database (Denmark)

    Rasmussen, Joachim

    The main purpose of this PhD project is to develop an ultrasonic method for tissue harmonic synthetic aperture imaging. The motivation is to advance the field of synthetic aperture imaging in ultrasound, which has shown great potentials in the clinic. Suggestions for synthetic aperture tissue...... system complexity compared to conventional synthetic aperture techniques. In this project, SASB is sought combined with a pulse inversion technique for 2nd harmonic tissue harmonic imaging. The advantages in tissue harmonic imaging (THI) are expected to further improve the image quality of SASB....... The first part of the scientific contribution investigates an implementation of pulse inversion for THI on the experimental ultrasound system SARUS. The technique is initially implemented for linear array transducers and then expanded for convex array transducers. The technique is evaluated based on spatial...

  7. Adaptive Synthetic Forces: Situation Awareness

    National Research Council Canada - National Science Library

    Hill, Randall

    2001-01-01

    ...: perception, comprehension, and prediction. Building on these ideas, we developed techniques for improving the situation awareness in synthetic helicopter pilots for the ModSAF military simulation by giving them more human-like perception...

  8. Designing synthetic networks in silico

    NARCIS (Netherlands)

    Smith, Robert W.; Sluijs, van Bob; Fleck, Christian

    2017-01-01

    Background: Evolution has led to the development of biological networks that are shaped by environmental signals. Elucidating, understanding and then reconstructing important network motifs is one of the principal aims of Systems & Synthetic Biology. Consequently, previous research has focused

  9. Is synthetic biology mechanical biology?

    Science.gov (United States)

    Holm, Sune

    2015-12-01

    A widespread and influential characterization of synthetic biology emphasizes that synthetic biology is the application of engineering principles to living systems. Furthermore, there is a strong tendency to express the engineering approach to organisms in terms of what seems to be an ontological claim: organisms are machines. In the paper I investigate the ontological and heuristic significance of the machine analogy in synthetic biology. I argue that the use of the machine analogy and the aim of producing rationally designed organisms does not necessarily imply a commitment to mechanical biology. The ideal of applying engineering principles to biology is best understood as expressing recognition of the machine-unlikeness of natural organisms and the limits of human cognition. The paper suggests an interpretation of the identification of organisms with machines in synthetic biology according to which it expresses a strategy for representing, understanding, and constructing living systems that are more machine-like than natural organisms.

  10. Programming languages for synthetic biology.

    Science.gov (United States)

    Umesh, P; Naveen, F; Rao, Chanchala Uma Maheswara; Nair, Achuthsankar S

    2010-12-01

    In the backdrop of accelerated efforts for creating synthetic organisms, the nature and scope of an ideal programming language for scripting synthetic organism in-silico has been receiving increasing attention. A few programming languages for synthetic biology capable of defining, constructing, networking, editing and delivering genome scale models of cellular processes have been recently attempted. All these represent important points in a spectrum of possibilities. This paper introduces Kera, a state of the art programming language for synthetic biology which is arguably ahead of similar languages or tools such as GEC, Antimony and GenoCAD. Kera is a full-fledged object oriented programming language which is tempered by biopart rule library named Samhita which captures the knowledge regarding the interaction of genome components and catalytic molecules. Prominent feature of the language are demonstrated through a toy example and the road map for the future development of Kera is also presented.

  11. Active control of continuous air jet with bifurcated synthetic jets

    Directory of Open Access Journals (Sweden)

    Dančová Petra

    2017-01-01

    Full Text Available The synthetic jets (SJs have many significant applications and the number of applications is increasing all the time. In this research the main focus is on the primary flow control which can be used effectively for the heat transfer increasing. This paper deals with the experimental research of the effect of two SJs worked in the bifurcated mode used for control of an axisymmetric air jet. First, the control synthetic jets were measured alone. After an adjustment, the primary axisymmetric jet was added in to the system. For comparison, the primary flow without synthetic jets control was also measured. All experiments were performed using PIV method whereby the synchronization between synthetic jets and PIV system was necessary to do.

  12. Aircraft measurements over Europe of an air pollution plume from Southeast Asia – aerosol and chemical characterization

    Directory of Open Access Journals (Sweden)

    A. Stohl

    2007-01-01

    Full Text Available An air pollution plume from Southern and Eastern Asia, including regions in India and China, was predicted by the FLEXPART particle dispersion model to arrive in the upper troposphere over Europe on 24–25 March 2006. According to the model, the plume was exported from Southeast Asia six days earlier, transported into the upper troposphere by a warm conveyor belt, and travelled to Europe in a fast zonal flow. This is confirmed by the retrievals of carbon monoxide (CO from AIRS satellite measurements, which are in excellent agreement with the model results over the entire transport history. The research aircraft DLR Falcon was sent into this plume west of Spain on 24 March and over Southern Europe on 25 March. On both days, the pollution plume was found close to the predicted locations and, thus, the measurements taken allowed the first detailed characterization of the aerosol content and chemical composition of an anthropogenic pollution plume after a nearly hemispheric transport event. The mixing ratios of CO, reactive nitrogen (NOy and ozone (O3 measured in the Asian plume were all clearly elevated over a background that was itself likely elevated by Asian emissions: CO by 17–34 ppbv on average (maximum 60 ppbv and O3 by 2–9 ppbv (maximum 22 ppbv. Positive correlations existed between these species, and a ΔO3/ΔCO slope of 0.25 shows that ozone was formed in this plume, albeit with moderate efficiency. Nucleation mode and Aitken particles were suppressed in the Asian plume, whereas accumulation mode aerosols were strongly elevated and correlated with CO. The suppression of the nucleation mode was likely due to the large pre-existing aerosol surface of the transported larger particles. Super-micron particles, likely desert dust, were found in part of the Asian pollution plume and also in surrounding cleaner air. The aerosol light absorption coefficient was enhanced in the plume (average values for individual plume encounters 0.25–0

  13. Recent applications of synthetic biology tools for yeast metabolic engineering

    DEFF Research Database (Denmark)

    Jensen, Michael Krogh; Keasling, Jay

    2015-01-01

    The last 20 years of metabolic engineering has enabled bio-based production of fuels and chemicals from renewable carbon sources using cost-effective bioprocesses. Much of this work has been accomplished using engineered microorganisms that act as chemical factories. Although the time required...... to engineer microbial chemical factories has steadily decreased, improvement is still needed. Through the development of synthetic biology tools for key microbial hosts, it should be possible to further decrease the development times and improve the reliability of the resulting microorganism. Together...... with continuous decreases in price and improvements in DNA synthesis, assembly and sequencing, synthetic biology tools will rationalize time-consuming strain engineering, improve control of metabolic fluxes, and diversify screening assays for cellular metabolism. This review outlines some recently developed...

  14. Synthetic biology: regulating industry uses of new biotechnologies.

    Science.gov (United States)

    Erickson, Brent; Singh, Rina; Winters, Paul

    2011-09-02

    In our view, synthetic biology is an extension of the continuum of genetic science that has been used safely for more than 40 years by the biotechnology industry in the development of commercial products. Examples of synthetic biology use by biotechnology companies illustrate the potential to substantially reduce research and development time and to increase speed to market. Improvements in the speed and cost of DNA synthesis are enabling scientists to design modified bacterial chromosomes that can be used in the production of renewable chemicals, biofuels, bioproducts, renewable specialty chemicals, pharmaceutical intermediates, fine chemicals, food ingredients, and health care products. Regulatory options should support innovation and commercial development of new products while protecting the public from potential harms.

  15. Investigation of fungal deterioration of synthetic paint binders using vibrational spectroscopic techniques.

    Science.gov (United States)

    Cappitelli, Francesca; Vicini, Silvia; Piaggio, Paolo; Abbruscato, Pamela; Princi, Elisabetta; Casadevall, Arturo; Nosanchuk, Joshua D; Zanardini, Elisabetta

    2005-01-14

    The deterioration of synthetic polymers caused by biological process is usually evaluated by visual inspection and measuring physical effects. In contrast to this approach, we have applied vibrational spectroscopies to study the biodegradation of the synthetic resins. 29 synthetic resins used as paint binding media, including acrylic, alkyd and poly(vinyl acetate) polymers, were examined for potential susceptibility to fungal degradation using the standard method ASTM G21-96(2002). In addition, the degraded resins were analysed by Raman spectroscopy, FT-IR and FT-IR photoacoustic spectroscopy. Almost all the acrylic resins studied proved to be resistant to microbial attack, while all alkyd resins and some poly(vinyl acetates) turned out to be biodegradable. Within a few days of inoculation Aspergillus niger was the most copious fungus on the biodegraded resins. A comparison of the IR and Raman spectra of control and biodegraded resins did not show any differences, but photoacoustic spectroscopy revealed additional bands for the fungal-degraded resins, consistent with the presence of fungal-derived substances. The additional bands in the photoacoustic spectra were due to the presence of Aspergillus niger and melanin, a fungal pigment. Since IR photoacoustic spectroscopy can be also a suitable technique for the chemical characterisation of binding media, the same spectroscopic analysis can be employed to both characterise the material and obtain evidence for fungal colonization. Microbial growth on Sobral 1241ML (alkyd resin) after 28 d (growth rating 4) compared with the non-inoculated resin.

  16. Synthetic peptides mimicking lipopolysaccharide as a potential vaccine candidates against Vibrio cholerae serogroup O1.

    Science.gov (United States)

    Ghazi, Fatemeh Mohammad Pour; Gargari, Seyed Latif Mousavi

    2017-08-01

    Cholera is a life-threatening diarrhea caused mainly by Gram-negative marine habitant Vibrio cholerae serogroup O1. Cholera vaccination is limited mainly to developed countries, due to the cumbersome and expensive task of vaccine production. In the present work, the aim was to study the immunogenicity of the synthetic mimotopes through two different routes of injection and oral administration. Lipopolysaccharide (LPS) is one of the immunogenic components in Gram-negative bacteria, which cannot be used as a vaccine candidate, due to its high toxic effect. Three phage-displayed selected peptides, with high affinity to anti-LPS VHH tested in our previous study, were chemically synthesized and used as a potential vaccine candidate. In order to enhance the antigenic properties and safe delivery, these peptides were conjugated to BSA as a carrier and encapsulated with PLGA. Peptides were injected intra-peritoneally or administered orally, alone or in combined form. Mice sera and feces were collected for assessment of humoral and mucosal antibody titers, respectively. ELISA plates were coated with mimotope conjugates and V. cholerae , Shigella sonnei and ETEC were used as target antigens. Antibody titer was measured by adding IgG and IgA as primary antibodies. Mice receiving three selected synthetic peptide conjugates (individually or in combination) showed higher antibody titer compared to control groups. The mice immunized with synthetic peptides were protected against more than 15 LD50 of V. cholerae. These peptides are mimicking LPS and can potentially act as vaccine candidates against V. cholerae.

  17. Natural and Synthetic Barriers to Immobilize Radionuclides

    International Nuclear Information System (INIS)

    Um, W.

    2011-01-01

    The experiments of weathering of glass waste form and the reacted sediments with simulated glass leachates show that radionuclide sequestration can be significantly enhanced by promoting the formation of secondary precipitates. In addition, synthetic phosphate-bearing nanoporous material exhibits high stability at temperature and has a very high K d value for U(VI) removal. Both natural and synthetic barrier materials can be used as additional efficient adsorbents for retarding transport of radionuclides for various contaminated waste streams and waste forms present at U. S. Department of Energy clean-up sites and the proposed geologic radioactive waste disposal facility. In the radioactive waste repository facility, natural or synthetic materials are planned to be used as a barrier material to immobilize and retard radionuclide release. The getter material can be used to selectively scavenge the radionuclide of interest from a liquid waste stream and subsequently incorporate the loaded getters in a cementitious or various monolithic waste forms. Also, the getter material is to reduce the release of radionuclides from monolithic waste forms. Also, the getter material is to reduce the release of radionuclides from monolithic waste forms. Also, the getter material is to reduce the release of radionuclides form monolithic waste forms by being emplaced as a backfill barrier material around the wastes or waste form to minimize the potential around the wastes or waste form to minimize the potential hazard of leached radioactive wastes. The barrier material should be highly efficient to sequester radionuclides and possess physical and chemical stability for long-term exposure to severe weathering conditions. Because potential leaching of radionuclides depends on various environmental and weathering conditions of the near-field repository, the barrier materials must be durable and not disintegrate under a range of moisture, temperature, pressure, radiation, Eh, ph. and

  18. Generating realistic synthetic meteoroid orbits

    Science.gov (United States)

    Vida, Denis; Brown, Peter G.; Campbell-Brown, Margaret

    2017-11-01