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1

Calorimetric and optical microscopic studies on one ferroelectric liquid-crystal compound with the smectic-A/emph> phase  

NASA Astrophysics Data System (ADS)

Detailed calorimetric measurements have been carried out on the chiral and racemic versions of one chiral liquid-crystal compound that exhibits an unusual and new smectic-A* (Sm-A*) phase in the pure chiral compound. Both the smectic-A (Sm-A)-smectic-C (Sm-C) transition in the racemic compound and the Sm-A*-chiral-Sm-C transition in the pure chiral compound display a first-order transition with heat-capacity anomalies qualitatively similar to but quantitatively different from that observed in the ordinary Sm-A-Sm-C transition. Results from optical microscopic studies on the phase diagram of binary mixtures of the dextro and levo versions of the chiral compounds are reported.

Huang, C. C.; Lin, D. S.; Goodby, J. W.; Waugh, M. A.; Stein, S. M.; Chin, E.

1989-10-01

2

Synthesis, calorimetric, structural and conductivity studies in a new thallium selenate tellurate adduct compound  

SciTech Connect

The crystal structure of the thallium selenate tellurate Tl{sub 2}SeO{sub 4}.Te(OH){sub 6} (TlSeTe) was determined by X-ray diffraction method. The title compound crystallizes in the monoclinic system with P2{sub 1}/c space group. The following parameters are: a = 12.358(3) A; b = 7.231(1) A; c = 11.986(2) A; {beta} = 111.092(2){sup o}; Z = 4. The structure can be regarded as being built of isolated TeO{sub 6} octahedra and SeO{sub 4} tetrahedra. The Tl{sup +} cations are intercalated between these kinds of polyhedra. The main feature of this structure is the coexistence of two different and independent anions (SeO{sub 4}{sup 2-} and TeO{sub 6}{sup 6-}) in the same unit cell. The structure is stable due to O-H...O hydrogen bonds which link tetrahedral and octahedral groups. Crystals of Tl{sub 2}SeO{sub 4}.Te(OH){sub 6} undergo three endothermal transitions at 373, 395 and 437 K. These transitions are detected by DSC and analyzed by dielectric measurements with impedance spectroscopy. The evolution of conductivity versus temperature showed the presence of a protonic conduction phase transition at 437 K. The phase transition at 373 K can be related to a structural phase transition, whereas the one at 395 K is ascribed as likely due to a ferroelectric-paraelectric phase transition.

Ktari, L. [Laboratoire de l'Etat Solide (LES), Faculte des Sciences de Sfax, 3000 Sfax (Tunisia); Abdelhedi, M. [Laboratoire de l'Etat Solide (LES), Faculte des Sciences de Sfax, 3000 Sfax (Tunisia); Laboratoire Leon Brouillon LLB, CEA Saclay, 91191 Gif-Sur-Yvette Cedex (France); Bouhlel, N. [Laboratoire de l'Etat Solide (LES), Faculte des Sciences de Sfax, 3000 Sfax (Tunisia); Dammak, M., E-mail: meddammak@yahoo.fr [Laboratoire de l'Etat Solide (LES), Faculte des Sciences de Sfax, 3000 Sfax (Tunisia); Cousson, A. [Laboratoire Leon Brouillon LLB, CEA Saclay, 91191 Gif-Sur-Yvette Cedex (France)

2009-08-05

3

PREFACE: Symmetries in Science XVI  

NASA Astrophysics Data System (ADS)

This volume of the proceedings ''Symmetries in Science XVI'' is dedicated to the memory of Miguel Lorente and Allan Solomon who both participated several times in these Symposia. We lost not only two great scientists and colleagues, but also two wonderful persons of high esteem whom we will always remember. Dieter Schuch, Michael Ramek There is a German saying ''all good things come in threes'' and ''Symmetries in Science XVI'', convened July 20–26, 2013 at the Mehrerau Monastery, was our third in the sequel of these symposia since taking it over from founder Bruno Gruber who instigated it in 1988 (then in Lochau). Not only the time seemed to have been perfect (one week of beautiful sunshine), but also the medley of participants could hardly have been better. This time, 34 scientists from 16 countries (more than half outside the European Union) came together to report and discuss their latest results in various fields of science, all related to symmetries. The now customary grouping of renowned experts and talented newcomers was very rewarding and stimulating for all. The informal, yet intense, discussions at ''Gasthof Lamm'' occurred (progressively later) each evening till well after midnight and finally till almost daybreak! However, prior to the opening ceremony and during the conference, respectively, we were informed that Miguel Lorente and Allan Solomon had recently passed away. Both attended the SIS Symposia several times and had many friends among present and former participants. Professor Peter Kramer, himself a long–standing participant and whose 80th birthday commemoration prevented him from attending SIS XVI, kindly agreed to write the obituary for Miguel Lorente. Professors Richard Kerner and Carol Penson (both also former attendees) penned, at very short notice, the tribute to Allan Solomon. The obituaries are included in these Proceedings and further tributes have been posted to our conference website. In 28 lectures and an evening poster–session, topics ranging from theoretical chemistry and molecular physics via fundamental problems in quantum theory to thermodynamics, nonlinear dynamics, soliton theory and finally cosmology, were examined and lively discussed. Nearly all the talks can also be viewed on the conference website. The majority of participants contributed to these Proceedings but some were unable to do so as their results were either previously submitted or published elsewhere. We refer to: · Quesne C 2013, J. Math. Phys. 54, 102102. · Spera M 2013, (Nankai Series in Pure, Applied Mathematics and Theoretical Physics): 11 Symmetries and Groups in Contemporary Physics: pp. 593–598 Proceedings of the XXIX International Colloquium on Group–Theoretical Methods in Physics Tianjin, China, 20 – 26 August 2012 (World Scientific, Singapore) · Snobl L and Winternitz P 2014, Classification and Identification of Lie Algebras, CRM Monograph Series 33 (Montreal) ISBN–10: 0–8218–4355–9, ISBN–13: 978–0–8218–4355–0 (http://www.ams.org/bookstore?fn=20&arg1=crmmseries&ikey=CRMM-33). Our personal thanks to Daniel and family! Endless support from the Schenk Family who, among other things, sponsored (yet again) the entire conference dinner (including wines and banquet hall) meant that some costs could be alleviated. We could therefore assist various colleagues from economically–weak countries, despite the lack of external funding. A financial deficit meant we would have had to forego the Conference Proceedings, published in previous years by IOP. After long deliberations, and with donations from Gerhard Berssenbrügge, Dr. Dr. Stephan Hauk and Dr. Volker Weisswange, this could be facilitated. We are very grateful to these private donors for their generous and wholehearted support. The staff of Collegium Mehrerau is also to be thanked for their hospitality. Finally, our sincere thanks to Yvette not only for her preparatory work and support during the conference, but also for her persistent interest and help in producing the Proceedings within a reasonable time. Dieter Schuc

2014-10-01

4

ALLELOPATHIC PLANTS. XVI. ARTEMISIA SPECIES  

Technology Transfer Automated Retrieval System (TEKTRAN)

The allelopathic effects of Artemisia annua, A. californica, A. princeps var. orientalis, A. tridentata, and A. vulgaris are reviewed. Naturally produced allelopathic compounds that reach target species via natural methods of dissemination (air, soil, and rain) are emphasized. Possible modes of ac...

5

Fast Electron Thermometry for Ultrasensitive Calorimetric Detection  

NASA Astrophysics Data System (ADS)

We demonstrate radio-frequency thermometry on a micrometer-sized metallic island below 100 mK. Our device is based on a normal-metal-insulator-superconductor tunnel junction coupled to a resonator with transmission readout. In the first generation of the device, we achieve 90 ? K /?{Hz } noise-equivalent temperature with 10 MHz bandwidth. We measure the thermal relaxation time of the electron gas in the island, which we find to be of the order of 100 ? s . Such a calorimetric detector, upon optimization, can be seamlessly integrated into superconducting circuits, with immediate applications in quantum-thermodynamics experiments down to single quanta of energy.

Gasparinetti, S.; Viisanen, K. L.; Saira, O.-P.; Faivre, T.; Arzeo, M.; Meschke, M.; Pekola, J. P.

2015-01-01

6

Calorimetric thermobarometry of experimentally shocked quartz  

NASA Technical Reports Server (NTRS)

Structural damage in experimentally shock-metamorphosed, granular quartz is quantitatively measurable by differential scanning calorimetry (DSC). Shock-induced loss of crystallinity is witnessed by disappearance of the alpha/beta phase transformation and evolution of a broad endoenthalpic strain peak at 650-900 K. The strain-energy peak grows rapidly at less than 10 GPa but declines with increasing shock pressure; it approaches zero at 32 GPa where vitrification is extensive. Effects of grain size and post-shock thermal history must be better understood before calorimetric thermobarometry of naturally shocked samples becomes possible.

Ocker, Katherine D.; Gooding, James L.; Hoerz, Friedrich

1994-01-01

7

EDITORIAL: Special issue: CAMOP MOLEC XVI  

NASA Astrophysics Data System (ADS)

In this special issue of CAMOP/Physica Scripta we would like to present a picture of the state-of-the-art in the field of the dynamics of molecular systems. It contains a collection of papers submitted in association with the most recent MOLEC meeting (MOLEC XVI), which was held in September 2006 in Levico Terme (Italy) to celebrate the 30th anniversary of the MOLEC conference series. The series of biennial European Conferences on the Dynamics of Molecular Systems (MOLEC) started in 1976, when the first meeting was held in Trento (Italy). Successive conferences were organized in Brandbjerg Højskole (Denmark, 1978), Oxford (UK, 1980), Nijmegen (The Netherlands, 1982), Jerusalem (Israel, 1984), Aussois (France, 1986), Assisi (Italy, 1988), Bernkastel-Kues (Germany, 1990), Prague (Czech Republic, 1992), Salamanca (Spain, 1994), Nyborg Strand (Denmark, 1996), Bristol (UK, 1998), Jerusalem (Israel, 2000), Istanbul (Turkey, 2002) and Nunspeet (The Netherlands, 2004). This is the second time that Physica Scripta has hosted a special issue dedicated to MOLEC. The previous issue ( Physica Scripta (2006) 73 C1-C89) was edited by Steven Stolte and Harold Linnartz following the MOLEC 2004 conference. Following the philosophy of CAMOP, we have asked invited speakers to summarize important problems in their research area, with the objective of setting forth the current thinking of leading researchers in atomic, molecular and optical physics. This comprises discussions of open questions, important new applications, new theoretical and experimental approaches and also predictions of where the field is heading. In addition to being authoritative contributions of acknowledged experts, we hope that the papers also appeal to non-specialists as each work contains a clear and broad introduction and references to the accessible literature. The present special issue comprises 17 papers, which are arranged according to the following topics: theoretical and experimental studies of molecular collisions and chemically reactive systems (papers by Toennies, Cavalli et al, Varandas, Nyman, Allan et al, Liu et al, Boxford et al); cooling and alignment of molecular systems (papers by Kumarappan et al, van de Meerakker et al); photon-matter interactions, spectroscopy and photodissociation (papers by Fárník and Buck, Golan et al, Borghesani et al, Coreno et al); theory of complex systems (papers by Villarreal et al, Bodo et al, Yurtsever and Calvo). The final contribution concerns the dynamics of systems of biological relevance (paper by Denicke et al). The paper by Toennies, one of the founding fathers of the MOLEC conference and winner of the MOLEC award in 1996, presents a comprehensive account of the experimental developments in the field of low energy collisions over the last 30 years, and provides a short outlook on how the most recent cooling and ultra cooling techniques (helium droplets and electro-magnetic laser traps) could open up new perspectives in the field of chemical reaction dynamics. Cavalli et al present a theoretical interpretation of overlapping resonances in the reactive cross section for the benchmark reaction F + H2?HF + H, explained by the formation of a short-lived state located in the transition state region and of a van der Waals metastable state in the exit valley. The subject of accurate ab initio calculations for potential energy surfaces is addressed by Varandas in a paper describing suitable modelling strategies to obtain intermolecular potentials at near spectroscopic resolution. In the following paper, Nyman gives an overview of how thermal rate constants for polyatomic chemical reactions can be calculated from first principles: the reaction H2 + CH3?CH4 + H is used as an example and theoretical results are compared with experimental ones. The `uncharted territory' of collision dynamics at the gas-liquid interface is explored in the pioneering contribution by Allan et al, in which experimental results on the reactivity of O atoms with long chain liquid hydrocarbons are interpreted with the aid of molecular dynamic

Ascenzi, Daniela; Franceschi, Pietro; Tosi, Paolo

2007-09-01

8

Radiation beam calorimetric power measurement system  

DOEpatents

A radiation beam calorimetric power measurement system for measuring the average power of a beam such as a laser beam, including a calorimeter configured to operate over a wide range of coolant flow rates and being cooled by continuously flowing coolant for absorbing light from a laser beam to convert the laser beam energy into heat. The system further includes a flow meter for measuring the coolant flow in the calorimeter and a pair of thermistors for measuring the temperature difference between the coolant inputs and outputs to the calorimeter. The system also includes a microprocessor for processing the measured coolant flow rate and the measured temperature difference to determine the average power of the laser beam.

Baker, John (Livermore, CA); Collins, Leland F. (Pleasanton, CA); Kuklo, Thomas C. (Ripon, CA); Micali, James V. (Dublin, CA)

1992-01-01

9

Nanowell-patterned TiO{sub 2} microcantilevers for calorimetric chemical sensing  

SciTech Connect

A sensitive calorimetric sensor using a TiO{sub 2} microcantilever with nanowells patterned on one of its sides is described. This single material cantilever is sensitive to temperature change without relying on the metal deposition-based bimetallic effect. The thermomechanical sensitivity originates from the structure dependent variations in both the elastic modulus and thermal expansion coefficient due to the presence of ordered nanowells. These cantilever beams offer an alternate and efficient chemical sensing route for vapor phase analytes using photothermal spectroscopy. Selective and sensitive detection of organophosphorus compounds, as well as their photocatalytic decomposition under ultraviolet light exposure are demonstrated.

Lee, Dongkyu, E-mail: dongkyu@ualberta.ca; Chae, Inseok; Thundat, Thomas [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4 (Canada); Kim, Seonghwan [Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta T2N 1N4 (Canada); Jeon, Sangmin [Department of Chemical Engineering, Pohang University of Science and Technology, Pohang (Korea, Republic of)

2014-04-07

10

compounds  

NASA Astrophysics Data System (ADS)

Size is the key factor of nanostructured materials, since all the structural, transport, electrical, magnetic and other physical properties can be tuned by this factor of materials. Only the condition is to choose appropriate inexpensive scale-processing method for material synthesis which offers good control over the stoichiometry, morphology and particle size distribution. Present communication deals with the studies on the sol-gel grown Y0.95Ca0.05MnO3 (YCMO) nanostructured compounds for their size-induced tuning of dielectric behavior. Structural studies reveal the single phasic nature with improved crystallite size with sintering temperature. Dielectric constant (real and imaginary) is found to increase with temperature and crystallite size/sintering temperature. High dielectric loss has been observed in the present system. Size dependent activation energy ( E a), obtained from modulus measurement, showing the increase in E a with crystallite size. The variation in various dielectric parameters and E a has been discussed in the light of crystallite size, crystallite boundaries, oxygen vacancies and charge carrier hopping.

Shah, N. A.

2014-10-01

11

78 FR 11939 - Social Security Ruling, SSR 13-2p.; Titles II and XVI: Evaluating Cases Involving Drug Addiction...  

Federal Register 2010, 2011, 2012, 2013, 2014

...XVI: Evaluating Cases Involving Drug Addiction and Alcoholism (DAA) AGENCY: Social...for how we consider whether ``drug addiction and alcoholism'' (DAA) is material...Titles II and XVI: Evaluation of Drug Addiction and Alcoholism. This SSR obsoletes...

2013-02-20

12

A calorimetric method to determine water activity  

NASA Astrophysics Data System (ADS)

A calorimetric method to determine water activity covering the full range of the water activity scale is presented. A dry stream of nitrogen gas is passed either over the solution whose activity should be determined or left dry before it is saturated by bubbling through water in an isothermal calorimeter. The unknown activity is in principle determined by comparing the thermal power of vaporization related to the gas stream with unknown activity to that with zero activity. Except for three minor corrections (for pressure drop, non-perfect humidification, and evaporative cooling) the unknown water activity is calculated solely based on the water activity end-points zero and unity. Thus, there is no need for calibration with references with known water activities. The method has been evaluated at 30 °C by measuring the water activity of seven aqueous sodium chloride solutions ranging from 0.1 mol kg-1 to 3 mol kg-1 and seven saturated aqueous salt solutions (LiCl, MgCl2, NaBr, NaCl, KCl, KNO3, and K2SO4) with known water activities. The performance of the method was adequate over the complete water activity scale. At high water activities the performance was excellent, which is encouraging as many other methods used for water activity determination have limited performance at high water activities.

Björklund, Sebastian; Wadsö, Lars

2011-11-01

13

The CALorimetric Electron Telescope, CALET, Mission  

NASA Astrophysics Data System (ADS)

We are developing the CALorimetric Electron Telescope, CALET, mission for the Japanese Experiment Module Exposed Facility, JEM-EF, of the International Space Station. Major scientific objectives are to search for nearby cosmic ray sources and dark matter by carrying out a precise measurement of the electrons in GeV 20 TeV and the gamma-rays in 20 MeV TeV. CALET has a unique capability to observe electrons and gamma-rays over 1 TeV since the hadron rejection power is more than 105 and the energy resolution better than a few percent over 100 GeV. The detector consists of an Imaging Calorimeter (IMC) with scintillating fiber belts and tungsten plates, a Total Absorption Calorimeter (TASC) with BGO logs, a Silicon Pixel Array (SIA) and a Scintillator Anti-Coincidence System (SACS). CALET has also a capability to measure protons and nuclei in 10 GeV 1000 TeV, and will have a function to monitor solar activity and gamma-ray bursts with additional instruments. The phase A study has started on a schedule of launch in 2013 by H-II Transfer Vehicle (HTV) for 5 years observation.

Torii, Shoji

14

Application of a downstream calorimetric probe to reactive plasma  

SciTech Connect

We explore the application of calorimetric probe located downstream from the plasma zone. By positioning the probe in a downstream location, the probe signal can be correlated with the integral energy flux carried by the effluent species as they propagate downstream from the plasma zone. Because the integral energy flux channeled downstream depends on the plasma conditions, it is possible to infer the plasma conditions from the probe response even though the probe is located away from the plasma zone. A calorimetric probe, based on resistance-temperature detector principle, adequate for fluorine plasma exposure is constructed. Probe operation is demonstrated for NF{sub 3}-Ar plasmas.

Chen, I.-S.; Neuner, Jeffery W.; Chen, Philip S.H.; Welch, James J.; DiMeo, Frank Jr. [ATMI, 7 Commerce Drive, Danbury, Connecticut 06810 (United States)

2005-12-05

15

Calorimetric Investigation of Hydrogen Bonding of Formamide and Its Methyl Derivatives in Organic Solvents and Water  

NASA Astrophysics Data System (ADS)

Formamide and its derivatives have a large number of practical applications; also they are structural fragments of many biomolecules. Hydrogen bonds strongly affect their physicochemical properties. In the present work a calorimetric study of formamide and its methyl derivatives was carried out. Enthalpies of solution at infinite dilution of formamide, N-methylformamide, and N, N-dimethylformamide in organic solvents at 298.15 K were measured. The relationships between the obtained enthalpies of solvation and the structure of the studied compounds were observed. Hydrogen-bond enthalpies of amides with chlorinated alkanes, ethers, ketones, esters, nitriles, amines, alcohols, and water were determined. The strength of hydrogen bonds of formamide, N-methylformamide, and N, N-dimethylformamide with proton donor solvents is practically equal. Enthalpies of hydrogen bonds of formamide with the proton acceptor solvents are two times larger in magnitude than the enthalpies of N-methylformamide. The process of hydrogen bonding of amides in aliphatic alcohols and water is complicated. The obtained enthalpies of hydrogen bonding in aliphatic alcohols vary considerably from the amide structure due to the competition between solute-solvent and solvent-solvent hydrogen bonds. Fourier transform infrared spectroscopic measurements were carried out to explain the calorimetric data. Hydration enthalpies of methyl derivatives of formamides contain a contribution of the hydrophobic effect. New thermochemical data on the hydrogen bonding of formamides may be useful for predicting the properties of biomacromolecules.

Varfolomeev, Mikhail A.; Rakipov, Ilnaz T.; Solomonov, Boris N.

2013-04-01

16

Metal carbon bond energies for adsorbed hydrocarbons from calorimetric data  

Microsoft Academic Search

Single crystal adsorption calorimetry (SCAC) is a powerful new method for measuring adsorption and reaction energies. Particularly for hydrocarbons, where little or no information is available from either experiment or theory on well-defined surfaces, this method can provide crucially needed information. Assignment of the measured calorimetric heats to the appropriate surface reaction yields directly reaction heats and heats of formation

Heike Gross; Charles T. Campbell; David A. King

2004-01-01

17

Accurate calorimetric power loss measurement for efficient power converters  

Microsoft Academic Search

The calorimetric power loss measurement is introduced for securing both higher accuracy measurement and faster measurement time. To reduce measurement accuracy error, copper leakage loss of wires is taken into consideration. To save measurement time, balancing relation between flow rate and temperature rise is also taken into consideration. Flow rate and temperature rise are largely dependent on sensor resolutions. To

Ryo Kamei; Tae-Woong Kim; Atsuo Kawamura

2011-01-01

18

Sensitivity of calorimetric indicators of soil microbial activity  

Microsoft Academic Search

Calorimetry was applied to develop a comparative study between the basal respiration and the degradation of an external carbon source in several soil samples. The main goals were to search for the connection between these reactions in soils and to test the sensitivity of calorimetric indices for the microbial activity. The soil samples were from the Brazilian Amazon and from

N. Barros; M. Gallego; S. Feijóo

2007-01-01

19

Calorimetric study of melted DNA glass Jessica Valle-Orero  

E-print Network

us to derive quantitative information on the relaxations of the DNA films, in particular to evaluateCalorimetric study of melted DNA glass Jessica Valle-Orero , Jean-Luc Garden , Jacques Richard differential scanning calorimetry (DSC) of the glassy behaviour of films made from DNA fibers. We show

Boyer, Edmond

20

Biodegradable composites filled with halloysite nanonotubes: Calorimetric investigations and structural issues  

NASA Astrophysics Data System (ADS)

Halloysite nanotubes were dispersed in a commercially biodegradable blends by melt compounding. Bionanocomposites based on a film-grade commercial blend of poly(hydroxybutirate)-co-valerate PHBV and poly(butylene adipate-co-therephthalate) PBAT and containg up to 10% by weigth of tubular clays (HNTs) were prepared by using a twin-screw lab extruder and filmed by a film-blowing equipment. Film samples were subjected to thermal and structural investigations. Calorimetric analysis showed that signals shape is clearly affected by the heating and cooling rate, respectively. Structural investigations performed by X-Ray diffraction tests satisfactorily allowed to interpret thermal behavior highlighting the occurrence of different crystalline modifications, depending on the scanning thermal rate, the inclusion of filler and its chemical functionalization.

Russo, Pietro; Vetrano, Barbara; Acierno, Domenico

2012-07-01

21

Micro-calorimetric sensor for trace explosive particle detection  

NASA Astrophysics Data System (ADS)

A micro differential thermal analysis (DTA) system is used for detection of trace explosive particles. The DTA system consists of two silicon micro chips with integrated heaters and temperature sensors. One chip is used for reference and one for the measurement sample. The sensor is constructed as a small silicon nitride bridge incorporating heater elements and a temperature measurement resistor. In this manuscript the DTA system is described and tested by measuring calorimetric response of DNT (2,4-Dinitrotoluene). The design of the senor is described and the temperature uniformity investigated using finite element modelings and Raman temperature measurements. The functionality is tested using two different kinds of explosive deposition techniques and calorimetric responses are obtained. Under the framework of the Xsense project at the Technical University of Denmark (DTU) which combines four independent sensing techniques, these micro DNT sensors will be included in handheld explosives detectors with applications in homeland security and landmine clearance.

Olsen, Jesper K.; Greve, Anders; Privorotskaya, N.; Senesac, L.; Thundat, T.; King, W. P.; Boisen, A.

2010-04-01

22

Gamma-ray measurements for simultaneous calorimetric assay  

SciTech Connect

Gamma-ray measurements obtained in the course of developing a simultaneous calorimetric assay system are described. Gamma-ray measurements of the isotopic composition of six, well-characterized plutonium oxide samples were obtained while the samples were in the calorimeter. These samples represent a range of plutonium masses from 19 to 231 g and two isotopic compositions. The values of effective specific power determined from the gamma-ray measurements agree with the values determined from destructive assay.

Rakel, D.A.

1982-03-02

23

Calorimetric studies of curium complexation. 2. Amino carboxylates  

Microsoft Academic Search

Calorimetric titrations using the long-lived isotope of curium (curium-248) have been conducted with nitrilotriacetate, trans-1,2-cyclohexanedinitrilotetraacetate, and trimethylenedinitrilotetraacetate. The data plus the stability constants measured previously allowed calculations of the thermodynamic parameters of the 1:1 complexation. Similar titrations were conducted with europium to provide comparison of the lanthanide and actinide trivalent ion behaviors. The enthalpy values for the amino polycarboxylate complexing

G. R. Choppin; E. N. Rizkalla; J. C. Sullivan

1987-01-01

24

Calorimetric seasonal characterization of culture and pasture soils  

Microsoft Academic Search

Isothermal and Differential Scanning Calorimetry is applied to analyze the evolution of soil using its microorganisms and\\u000a organic matter as bioindicators of soil quality. This study was carried out with two similar soils under different agricultural\\u000a activities: culture and pasture. Sampling and measurements were performed through 1 year in order to check the sensitivity\\u000a of common calorimetric indicators of microbial activity

J. Salgado; M. Villanueva; O. Núñez-Fernández; J. Proupín-Castiñeiras; N. Barros; J. A. Rodríguez-Añón

2009-01-01

25

45 CFR 233.145 - Expiration of medical assistance programs under titles I, IV-A, X, XIV and XVI of the Social...  

Code of Federal Regulations, 2014 CFR

...assistance programs under titles I, IV-A, X, XIV and XVI of the Social Security Act...assistance programs under titles I, IV-A, X, XIV and XVI of the Social Security Act...made to any State under title I, IV-A, X, XIV or XVI of the Social...

2014-10-01

26

45 CFR 233.145 - Expiration of medical assistance programs under titles I, IV-A, X, XIV and XVI of the Social...  

Code of Federal Regulations, 2011 CFR

...assistance programs under titles I, IV-A, X, XIV and XVI of the Social Security Act...assistance programs under titles I, IV-A, X, XIV and XVI of the Social Security Act...made to any State under title I, IV-A, X, XIV or XVI of the Social...

2011-10-01

27

45 CFR 233.145 - Expiration of medical assistance programs under titles I, IV-A, X, XIV and XVI of the Social...  

Code of Federal Regulations, 2013 CFR

...assistance programs under titles I, IV-A, X, XIV and XVI of the Social Security Act...assistance programs under titles I, IV-A, X, XIV and XVI of the Social Security Act...made to any State under title I, IV-A, X, XIV or XVI of the Social...

2013-10-01

28

45 CFR 233.145 - Expiration of medical assistance programs under titles I, IV-A, X, XIV and XVI of the Social...  

Code of Federal Regulations, 2010 CFR

...assistance programs under titles I, IV-A, X, XIV and XVI of the Social Security Act...assistance programs under titles I, IV-A, X, XIV and XVI of the Social Security Act...made to any State under title I, IV-A, X, XIV or XVI of the Social...

2010-10-01

29

45 CFR 233.145 - Expiration of medical assistance programs under titles I, IV-A, X, XIV and XVI of the Social...  

Code of Federal Regulations, 2012 CFR

...assistance programs under titles I, IV-A, X, XIV and XVI of the Social Security Act...assistance programs under titles I, IV-A, X, XIV and XVI of the Social Security Act...made to any State under title I, IV-A, X, XIV or XVI of the Social...

2012-10-01

30

Formation and properties of ice XVI obtained by emptying a type sII clathrate hydrate  

NASA Astrophysics Data System (ADS)

Gas hydrates are ice-like solids, in which guest molecules or atoms are trapped inside cages formed within a crystalline host framework (clathrate) of hydrogen-bonded water molecules. They are naturally present in large quantities on the deep ocean floor and as permafrost, can form in and block gas pipelines, and are thought to occur widely on Earth and beyond. A natural point of reference for this large and ubiquitous family of inclusion compounds is the empty hydrate lattice, which is usually regarded as experimentally inaccessible because the guest species stabilize the host framework. However, it has been suggested that sufficiently small guests may be removed to leave behind metastable empty clathrates, and guest-free Si- and Ge-clathrates have indeed been obtained. Here we show that this strategy can also be applied to water-based clathrates: five days of continuous vacuum pumping on small particles of neon hydrate (of structure sII) removes all guests, allowing us to determine the crystal structure, thermal expansivity and limit of metastability of the empty hydrate. It is the seventeenth experimentally established crystalline ice phase, ice XVI according to the current ice nomenclature, has a density of 0.81 grams per cubic centimetre (making it the least dense of all known crystalline water phases) and is expected to be the stable low-temperature phase of water at negative pressures (that is, under tension). We find that the empty hydrate structure exhibits negative thermal expansion below about 55 kelvin, and that it is mechanically more stable and has at low temperatures larger lattice constants than the filled hydrate. These observations attest to the importance of kinetic effects and host-guest interactions in clathrate hydrates, with further characterization of the empty hydrate expected to improve our understanding of the structure, properties and behaviour of these unique materials.

Falenty, Andrzej; Hansen, Thomas C.; Kuhs, Werner F.

2014-12-01

31

Measurement of the calorimetric energy scale in MINOS  

SciTech Connect

MINOS is a long-baseline neutrino oscillation experiment. A neutrino beam is created at the Fermi National Accelerator Laboratory in Illinois and fired down through the Earth. Measurements of the energy spectra and composition of the neutrino beam are made both at the source using the Near detector and 735 km away at the Soudan Underground Laboratory in Minnesota using the Far detector. By comparing the spectrum and flavour composition of the neutrino beam between the two detectors neutrino oscillations can be observed. Such a comparison depends on the accuracy of the relative calorimetric energy scale. This thesis details a precise measurement of the calorimetric energy scale of the MINOS Far detector and Calibration detector using stopping muons with a new ''track window'' technique. These measurements are used to perform the relative calibration between the two detectors. This calibration has been accomplished to 1.7% in data and to significantly better than 2% in the Monte Carlo simulation, thus achieving the MINOS relative calibration target of 2%. A number of cross-checks have been performed to ensure the robustness of the calorimetric energy scale measurements. At the Calibration detector the test-beam energy between run periods is found to be consistent with the detector response to better than 2% after the relative calibration is applied. The muon energy loss in the MINOS detectors determined from Bethe-Bloch predictions, data and Monte Carlo are compared and understood. To estimate the systematic error on the measurement of the neutrino oscillation parameters caused by a relative miscalibration a study is performed. A 2% relative miscalibration is shown to cause a 0.6% bias in the values of {Delta}m{sup 2} and sin{sup 2}(2{theta}).

Hartnell, Jeffrey J.; /Oxford U.

2005-06-01

32

Calorimetric investigations of the different castes of honey bees, Apis mellifera carnica  

Microsoft Academic Search

Honey bees of different age and castes were investigated calorimetrically at 20, 25 and 30 °C. Experiments were completed by endoscopic observation of the insects in the visible and the near infrared range and by acoustical monitoring and subsequent frequency analysis of various locomotor activities. Direct calorimetric results of this paper are compared with data of indirect calorimetry from the

L. Fahrenholz; I. Lamprecht; B. Schricker

1992-01-01

33

Adiabatic calorimetric decomposition studies of 50 wt.% hydroxylamine/water.  

PubMed

Calorimetric data can provide a basis for determining potential hazards in reactions, storage, and transportation of process chemicals. This work provides calorimetric data for the thermal decomposition behavior in air of 50wt.% hydroxylamine/water (HA), both with and without added stabilizers, which was measured in closed cells with an automatic pressure tracking adiabatic calorimeter (APTAC). Among the data provided are onset temperatures, reaction order, activation energies, pressures of noncondensable products, thermal stability at 100 degrees C, and the effect of HA storage time. Discussed also are the catalytic effects of carbon steel, stainless steel, stainless steel with silica coating, inconel, titanium, and titanium with silica coating on the reaction self-heat rates and onset temperatures. In borosilicate glass cells, HA was relatively stable at temperatures up to 133 degrees C, where the HA decomposition self-heat rate reached 0.05 degrees C/min. The added stabilizers appeared to reduce HA decomposition rates in glass cells and at ambient temperatures. The tested metals and metal surfaces coated with silica acted as catalysts to lower the onset temperatures and increase the self-heat rates. PMID:11165058

Cisneros, L O; Rogers, W J; Mannan, M S

2001-03-19

34

Induction of type XVI collagen expression facilitates proliferation of oral cancer cells.  

PubMed

Type XVI collagen belongs to the family of fibril-associated collagens with interrupted triple helices (FACIT). Recently, high affinity to integrin alpha1beta1 has been shown allowing cells expressing those integrins to attach and spread on recombinant type XVI collagen. Here, we show that type XVI collagen is overexpressed in dysplastic areas of mucosal epithelium from oral squamous cell carcinoma (OSCC) patients. Induction of its expression in OSCC cell lines (COLXVI cells) leads to an increased expression of Kindlin-1. Moreover, we demonstrate a significantly increased Kindlin-1/beta1-integrin interaction. Additionally, we detected a higher number of activated beta1-integrins in COLXVI cells and found a neo-expression of alpha1 integrin subunit on these cells. FACS analysis revealed a significantly higher amount of COLXVI cells in S-phase and G2/M-phase 6h after synchronisation leading to a markedly higher proliferation activity. Blocking beta1-integrins with a specific antibody resulted in reduced proliferation of COLXVI cells. In summary, we demonstrate that overexpression of type XVI collagen in aberrant oral keratinocytes leads to Kindlin-1 induction, increased Kindlin-1/beta1-integrin interaction, integrin activation and subsequently to a proliferative cellular phenotype. PMID:21251976

Ratzinger, Sabine; Grässel, Susanne; Dowejko, Albert; Reichert, Torsten E; Bauer, Richard J

2011-03-01

35

American Press Coverage of the Execution of Louis XVI: A Lesson Strategy for Gauging Opinion.  

ERIC Educational Resources Information Center

In this unit of study high school students read and discuss U.S. newspaper articles reporting the trial and execution of the French king Louis XVI. Students look for key words and phrases that might indicate a subtle favorable or unfavorable opinion. (RM)

Lankiewicz, Donald

1985-01-01

36

[Could phimosis have been the cause of sexual difficulties and delayed fertility of Louis XVI (1754-1793)?].  

PubMed

The great majority of historians agree that the marriage of Louis XVI and Marie-Antoinette was only consumated seven years after the official ceremony. This delay could have been due to a genital malformation (phimosis) of Louis XVI, a strict religious education, a traumatic childhood and the young age of the two spouses, factors that may have inhibited their sexuality. In this article, the authors try to determine whether Louis XVI was able to overcome his sexual difficulties following an operation (circumcision) or as a result of spontaneous cure. PMID:11980007

Androutsos, Georges

2002-02-01

37

78 FR 22361 - Social Security Ruling, SSR 13-1p; Titles II and XVI: Agency Processes for Addressing Allegations...  

Federal Register 2010, 2011, 2012, 2013, 2014

...II and XVI: Agency Processes for Addressing Allegations of Unfairness, Prejudice, Partiality, Bias, Misconduct, or Discrimination by Administrative Law Judges (ALJs); Correction AGENCY: Social Security Administration. ACTION: Notice of Social...

2013-04-15

38

78 FR 8217 - Social Security Ruling, SSR 13-1p; Titles II and XVI: Agency Processes for Addressing Allegations...  

Federal Register 2010, 2011, 2012, 2013, 2014

...II and XVI: Agency Processes for Addressing Allegations of Unfairness, Prejudice, Partiality, Bias, Misconduct, or Discrimination by Administrative Law Judges (ALJs); Correction AGENCY: Social Security Administration. ACTION: Notice of Social...

2013-02-05

39

78 FR 9987 - Social Security Ruling, SSR 13-1p; Titles II and XVI: Agency Processes for Addressing Allegations...  

Federal Register 2010, 2011, 2012, 2013, 2014

...II and XVI: Agency Processes for Addressing Allegations of Unfairness, Prejudice, Partiality, Bias, Misconduct, or Discrimination by Administrative Law Judges (ALJs); Correction AGENCY: Social Security Administration. ACTION: Notice of Social...

2013-02-12

40

78 FR 17744 - Social Security Ruling, SSR 13-2p; Titles II and XVI: Evaluating Cases Involving Drug Addiction...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Docket No. SSA-2012-0006] Social Security Ruling, SSR 13-2p; Titles II and XVI: Evaluating Cases Involving Drug Addiction and Alcoholism (DAA); Correction AGENCY: Social Security Administration. ACTION: Notice of Social Security...

2013-03-22

41

Fast electron thermometry towards ultra-sensitive calorimetric detection  

E-print Network

We demonstrate radiofrequency thermometry on a micrometer-sized metallic island below 100 mK. Our device is based on a normal metal-insulator-superconductor tunnel junction coupled to a resonator with transmission readout. In the first generation of the device, we achieve 90 {\\mu}K/Hz^1/2 noise-equivalent temperature with 10 MHz bandwidth. We measure the thermal relaxation time of the electron gas in the island, which we find to be of the order of 100 {\\mu}s. Such a calorimetric detector, upon optimization, can be seamlessly integrated into superconducting circuits, with immediate applications in quantum-thermodynamics experiments down to single quanta of energy.

S. Gasparinetti; K. L. Viisanen; O. -P. Saira; T. Faivre; M. Arzeo; M. Meschke; J. P. Pekola

2014-11-04

42

Nanoclay modified polycarbonate blend nanocomposites: Calorimetric and mechanical properties  

NASA Astrophysics Data System (ADS)

The research is devoted to characterization of polycarbonate (PC)/acrylonitrile-butadiene styrene (ABS) blend nanocomposites in respects to it mechanical and calorimetric properties. It is shown that PC blend with 10wt% of ABS is more suitable for development of polymer-clay nanocomposites than PC blend with 40wt.% of ABS. It is revealed that the greatest modulus and strength increment is observed for PC/10wt.%ABS blend nanocomposites, containing aromatic organomodifier treated clay (Dellite 43B). It is also determined that optimal nanofiller content for the investigated PC/10%ABS blend is 1.5 wt.%. Increase of mechanical characteristics of PC/10wt.%ABS blend nanocomposites is accompanied with the rise of glass transition temperatures of both polymeric phases, particularly that of PC.

Zicans, Janis; Meri, Remo Merijs; Ivanova, Tatjana; Berzina, Rita; Kalnins, Martins; Maksimovs, Roberts

2014-05-01

43

Calorimetric studies of the ammonia-water system with application to the outer solar system  

NASA Technical Reports Server (NTRS)

A series of heating experiments was performed on the condensed ammonia-water system using a differential scanning calorimeter (DSC). The water-rich samples were cooled quickly to below 130 K, then heated at a variety of rates. Rather than a single peritectic melt at 176 K, expected for the equilibrium system of water ice and ammonia dihydrate, four enthalpic transitions were repeatedly seen in the temperature range 150-176 K. These transitions are generally consistent with the earlier calorimetric results of Van Kasteren (1973), who interpreted the lowest temperature exotherm as crystallization of an amorphous ammonia-water compound formed during cooling. We propose that both sets of experiments are seeing the crystallization of ammonia monohydrate, which is metastable relative to the dihydrate, followed by partial remelting and crystallization of dihydrate upon further heating. The apparent stability of the monohydrate in the dihydrate equilibrium field implies a potentially complex behavior of ammonia-water ices in satellites. Possible self-heating of the mixture by several tens of degrees up to the 170 K eutectic could make mobilization of ammonia-water liquids in icy satellite interiors energetically easier than previously thought.

Yarger, Jeffery; Lunine, Jonathan I.; Burke, Michael

1993-01-01

44

Calorimetric studies of the ammonia-water system with application to the outer solar system  

NASA Astrophysics Data System (ADS)

A series of heating experiments was performed on the condensed ammonia-water system using a differential scanning calorimeter (DSC). The water-rich samples were cooled quickly to below 130 K, then heated at a variety of rates. Rather than a single peritectic melt at 176 K, expected for the equilibrium system of water ice and ammonia dihydrate, four enthalpic transitions were repeatedly seen in the temperature range 150-176 K. These transitions are generally consistent with the earlier calorimetric results of Van Kasteren (1973), who interpreted the lowest temperature exotherm as crystallization of an amorphous ammonia-water compound formed during cooling. We propose that both sets of experiments are seeing the crystallization of ammonia monohydrate, which is metastable relative to the dihydrate, followed by partial remelting and crystallization of dihydrate upon further heating. The apparent stability of the monohydrate in the dihydrate equilibrium field implies a potentially complex behavior of ammonia-water ices in satellites. Possible self-heating of the mixture by several tens of degrees up to the 170 K eutectic could make mobilization of ammonia-water liquids in icy satellite interiors energetically easier than previously thought.

Yarger, J.; Lunine, J. I.; Burke, M.

1993-07-01

45

Huwentoxin-XVI, an analgesic, highly reversible mammalian N-type calcium channel antagonist from Chinese tarantula Ornithoctonus huwena.  

PubMed

N-type calcium channels play important roles in the control of neurotransmission release and transmission of pain signals to the central nervous system. Their selective inhibitors are believed to be potential drugs for treating chronic pain. In this study, a novel neurotoxin named Huwentoxin-XVI (HWTX-XVI) specific for N-type calcium channels was purified and characterized from the venom of Chinese tarantula Ornithoctonus huwena. HWTX-XVI is composed of 39 amino acid residues including six cysteines that constitute three disulfide bridges. HWTX-XVI could almost completely block the twitch response of rat vas deferens to low-frequency electrical stimulation. Electrophysiological assay indicated that HWTX-XVI specifically inhibited N-type calcium channels in rat dorsal root ganglion cells (IC50 ?60 nM). The inhibitory effect of HWTX-XVI on N-type calcium channel currents was dose-dependent and similar to that of CTx-GVIA and CTx-MVIIA. However, the three peptides exhibited markedly different degrees of reversibility after block. The toxin had no effect on voltage-gated T-type calcium channels, potassium channels or sodium channels. Intraperitoneal injection of the toxin HWTX-XVI to rats elicited significant analgesic responses to formalin-induced inflammation pain. Toxin treatment also changed withdrawal latency in hot plate tests. Intriguingly, we found that intramuscular injection of the toxin reduced mechanical allodynia induced by incisional injury in Von Frey test. Thus, our findings suggest that the analgesic potency of HWTX-XVI and its greater reversibility could contribute to the design of a novel potential analgesic agent with high potency and low side effects. PMID:24467846

Deng, Meichun; Luo, Xuan; Xiao, Yucheng; Sun, Zhenghua; Jiang, Liping; Liu, Zhonghua; Zeng, Xiongzhi; Chen, Hanchun; Tang, Jianhua; Zeng, Weimin; Songping Liang

2014-04-01

46

Adsorption of methylene blue on raw and MTZ/imogolite hybrid surfaces: effect of concentration and calorimetric investigation.  

PubMed

The synthetic imogolite sample was used for organofunctionalization process with 2-mercaptothiazoline (MTZ). The compound 2-mercaptothiazoline was anchored onto imogolite surface by heterogeneous route. Due to the increment of basic centers attached to the pendant chains the dye adsorption capability of the final chelating material, was found to be higher than is precursor. The ability of these materials to remove methylene blue from aqueous solution was followed by a series of adsorption isotherms at room temperature and pH 4.0. The maximum number of moles adsorbed was determined to be 40.32×10(-2) and 65.13×10(-2) mmol g(-1) for IMO and IMO(MTZ), respectively. The energetic effects caused by dye cations adsorption were determined through calorimetric titrations. Thermodynamics indicated the existence of favorable conditions for such methylene blue-nitrogen and sulfur interactions. PMID:20674169

Guerra, Denis L; Batista, Adriano C; Viana, Rúbia R; Airoldi, Claudio

2010-11-15

47

Calorimetric study and thermal analysis of [ErY(Ala) 4 (H 2 O) 8 ](ClO 4 ) 6 ( Ala =ALANINE)  

Microsoft Academic Search

A solid complex of rare-earth compounds with alanine, [ErY(Ala)4(H2O)8](ClO4)6 (Ala=alanine), was synthesized, and a calorimetric study and thermal analysis for it was performed through adiabatic calorimetry\\u000a and thermogravimetry. The low-temperature heat capacity of [ErY(Ala)4(H2O)8](ClO4)6 was measured with an automated adiabatic precision calorimeter over the temperature range from 78 to 377 K. A solid-solid\\u000a phase transition was found between 99 and

B. P. Liu; Z. C. Tan; Z. D. Nan; P. Liu; L. X. Sun; F. Xu; X. Z. Lan

2003-01-01

48

Photoionization cross sections for Fe XVI and Fe XVII recombination rate coefficients  

NASA Astrophysics Data System (ADS)

The Breit-Pauli R-matrix codes are utilized in a detailed study of the photoionization of the ground state of Fe XVI (2s(22p^63s) (2S_{1/2}) ). High resolution total and partial cross sections are obtained using 37 Jpi configuration interaction type wavefunctions to represent the residual ion, Fe XVII, after 3s, 2p and 2s photoionization. For the total cross section, the work of Verner et al. and previous Opacity Project calculations are in fair agreement with the present results, while relativistic effects are seen to have a noticeable but not an overly significant effect on the background cross section. The derived partial cross sections are used in a calculation of rates for the recombination of states of Fe XVII to the ground state of Fe XVI.

Donnelly, D.; Bell, K. L.; Darlington, W. G. V.; Reid, R. H. G.; Keenan, F. P.

1999-09-01

49

Thermodynamic model for calorimetric and phase coexistence properties of coal derived fluids. Final technical report  

SciTech Connect

The work on this project was initiated on September 1, 1989. The project consisted of three different tasks. 1. A thermodynamic model to predict VLE and calorimetric properties of coal liquids. 2. VLE measurements at high temperature and high pressure for coal model compounds and 3. Chromatographic characterization of coal liquids for distribution of heteroatoms. The thermodynamic model developed is an extension of the previous model developed for VLE of coal derived fluids (DOE Grant no. FG22-86PC90541). The model uses the modified UNIFAC correlation for the liquid phase. Some unavailable UNIFAC interactions parameters have been regressed from experimental VLE and excess enthalpy data. The model is successful in predicting binary VLE and excess enthalpy data. Further refinements of the model are suggested. An apparatus for the high pressure high temperature VLE data measurements has been built and tested. Tetralin-Quinoline is the first binary system selected for data measurements. The equipment was tested by measuring 325{degree}C isotherm for this system and comparing it with literature data. Additional isotherms at 350{degree}C and 370{degree}C have been measured. The framework for a characterization procedure for coal derived liquids has been developed. A coal liquid is defined by a true molecular weight distribution and distribution of heteroatoms as a function of molecular weights. Size exclusions liquid chromatography, elemental analysis and FTIR spectroscopy methods are used to obtain the molecular weight and hetroatom distributions. Further work in this area should include refinements of the characterization procedure, high temperature high pressure VLE data measurements for selective model compound binary systems, and improvement of the thermodynamic model using the new measured data and consistent with the developments in the characterization procedure.

Kabadi, V.N.

1992-10-01

50

Genomic analysis of the blood attributed to Louis XVI (1754-1793), king of France.  

PubMed

A pyrographically decorated gourd, dated to the French Revolution period, has been alleged to contain a handkerchief dipped into the blood of the French king Louis XVI (1754-1793) after his beheading but recent analyses of living males from two Bourbon branches cast doubts on its authenticity. We sequenced the complete genome of the DNA contained in the gourd at low coverage (~2.5×) with coding sequences enriched at a higher ~7.3× coverage. We found that the ancestry of the gourd's genome does not seem compatible with Louis XVI's known ancestry. From a functional perspective, we did not find an excess of alleles contributing to height despite being described as the tallest person in Court. In addition, the eye colour prediction supported brown eyes, while Louis XVI had blue eyes. This is the first draft genome generated from a person who lived in a recent historical period; however, our results suggest that this sample may not correspond to the alleged king. PMID:24763138

Olalde, Iñigo; Sánchez-Quinto, Federico; Datta, Debayan; Marigorta, Urko M; Chiang, Charleston W K; Rodríguez, Juan Antonio; Fernández-Callejo, Marcos; González, Irene; Montfort, Magda; Matas-Lalueza, Laura; Civit, Sergi; Luiselli, Donata; Charlier, Philippe; Pettener, Davide; Ramírez, Oscar; Navarro, Arcadi; Himmelbauer, Heinz; Marquès-Bonet, Tomàs; Lalueza-Fox, Carles

2014-01-01

51

Genomic analysis of the blood attributed to Louis XVI (1754–1793), king of France  

PubMed Central

A pyrographically decorated gourd, dated to the French Revolution period, has been alleged to contain a handkerchief dipped into the blood of the French king Louis XVI (1754–1793) after his beheading but recent analyses of living males from two Bourbon branches cast doubts on its authenticity. We sequenced the complete genome of the DNA contained in the gourd at low coverage (~2.5×) with coding sequences enriched at a higher ~7.3× coverage. We found that the ancestry of the gourd's genome does not seem compatible with Louis XVI's known ancestry. From a functional perspective, we did not find an excess of alleles contributing to height despite being described as the tallest person in Court. In addition, the eye colour prediction supported brown eyes, while Louis XVI had blue eyes. This is the first draft genome generated from a person who lived in a recent historical period; however, our results suggest that this sample may not correspond to the alleged king. PMID:24763138

Olalde, Iñigo; Sánchez-Quinto, Federico; Datta, Debayan; Marigorta, Urko M.; Chiang, Charleston W. K.; Rodríguez, Juan Antonio; Fernández-Callejo, Marcos; González, Irene; Montfort, Magda; Matas-Lalueza, Laura; Civit, Sergi; Luiselli, Donata; Charlier, Philippe; Pettener, Davide; Ramírez, Oscar; Navarro, Arcadi; Himmelbauer, Heinz; Marquès-Bonet, Tomàs; Lalueza-Fox, Carles

2014-01-01

52

Laser calorimetric absorptance testing of samples with varying geometry  

NASA Astrophysics Data System (ADS)

Laser calorimetry is based on the measurement and evaluation of the temperature increase caused by absorption in the sample exposed to laser radiation. A temperature distribution develops in the irradiated sample as a result of dependence on the thermal diffusivity of the sample. Therefore, finding a correlation between the temperature increase and absorption becomes a complex task. This challenge was met by keeping the sample geometry at a standard size and simulating the thermal distribution for a number of optical materials. Using this method, Laser Zentrum Hannover e.V. (LZH) developed a calorimetric test setup that offers fully calibrated absorptance values for sample diameters of 25 mm (or 1 in.) with a total error of below 13% and a relative measurement error of below 5%. However, this technique is limited to the above-mentioned sample geometry. This work presents an approach to adjust the measurement configuration to numerous sample sizes for standard circular laser components. Finite element analysis and experimental verification are presented for exemplary values of the samples' diameters. Based on the different sample mount concept, this procedure allows utilizing flexibility in test wavelength and angle of incidence, combined with the sensitivity level sufficient for current optical materials.

Balasa, Istvan; Jensen, Lars O.; Ristau, Detlev

2014-12-01

53

Fructose-selective calorimetric biosensor in flow injection analysis.  

PubMed

A highly selective, interference free biosensor for the measurement of fructose in real syrup samples was developed. The assay is based on the phosphorylation of D(-)fructose to fructose-6-phosphate by hexokinase and subsequent conversion of fructose-6-phosphate to fructose-1,6-biphosphate by fructose-6-phosphate-kinase. The heat liberated in the second reaction is monitored using an enzyme thermistor. The major advantages of this biosensor are rapid and selective measurement of fructose without the need to eliminate glucose and inexpensive FIA-based, mediator-free calorimetric measurement suitable for regular fructose analysis. This method was optimised for parameters, such as pH, ionic strength, interference, operational stability and shelf life. Good and reproducible linearity (0.5-6.0 mM) with a detection limit of 0.12 mM was obtained. Fructose determination in commercial syrup samples and spiked samples confirmed the reliability of this set-up and technique. The biosensor gave reproducible results with good overall stability for continuous measurements over a period of three months besides a useful shelf life of six months. The method could be used for routine fructose monitoring in food samples. PMID:20457296

Bhand, Sunil G; Soundararajan, Srimathi; Surugiu-Wärnmark, Ioana; Milea, Jaqueline Simona; Dey, Estera Szwajcer; Yakovleva, Maria; Danielsson, Bengt

2010-05-23

54

The Calorimetric Glass Transition of Polystyrene Ultrathin Films  

NASA Astrophysics Data System (ADS)

The glass transition temperature (Tg) for nanoconfined materials have been widely studied since the early 1990s. For supported polystyrene ultrathin films, Tg differs from bulk value. Recent work has attributed nanoconstrained Tg effects to artifact. In this study, we attempted to resolve this controversy and measure Tg for single polystyrene ultrathin films using Flash DSC. Films have been prepared in two ways: spincast films placed on a layer of inert oil or grease and films directly spincast on the back of the calorimetric chip. For the films on oil or on grease, the 160 nm thick films show no Tg depression. On the other hand, thinner films on oil and on grease show a Tg depression which decreases with increasing cooling rate. The depression reverts to the bulk values over the course of a day at 160 ^oC due to dewetting and thickening. For directly spincast films, no Tg depression is observed, consistent with results from other nanocalorimetry work. Our results are consistent with literature results that Tg decreases with decreasing substrate surface energy, and they also demonstrate that the Tg depression observed is not due to degradation or to plasticization effects.

Gao, Siyang; Koh, Yung P.; Simon, Sindee S.

2013-03-01

55

THEORETICAL WAVELENGTHS OF Fe XVI L-SHELL TRANSITIONS AND COMPARISON WITH LABORATORY MEASUREMENTS AND CHANDRA OBSERVATIONS OF CAPELLA  

SciTech Connect

We have used the relativistic multi-reference Moller-Plesset perturbation theory to calculate the energy levels of Fe XVI, including those of the autoionizing levels with a hole state in the L shell. Comparison of the resulting L-shell transition wavelengths with those from recent laboratory measurements shows remarkable agreement, i.e., agreement within the experimental uncertainties. Our calculation allows us to predict the wavelength of the second strongest 2p-3d Fe XVI line, which has not yet been directly observed in the laboratory, to be 15.266 A. This wavelength is within 0.0042 A of the strong Fe XVII line commonly labeled 3D. Relying on the high accuracy of our calculations, we have reassigned two previously identified lines and predict a different location than previously thought for the strongest Fe XVI magnetic quadrupole transition. Inspection of the spectra of Capella recorded with the transmission grating spectrometers on the Chandra X-ray Observatory yields features corresponding to the predicted location of the innershell excited Fe XVI lines. These features have not been identified before. Our analysis shows that these features are most likely from Fe XVI.

Beiersdorfer, P. [Physics Division, Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Diaz, F.; Ishikawa, Y. [Department of Chemistry and the Chemical Physics Program, University of Puerto Rico, San Juan, PR 00931 (United States)

2012-02-01

56

Absolute calorimetric calibration of low energy brachytherapy sources  

NASA Astrophysics Data System (ADS)

In the past decade there has been a dramatic increase in the use of permanent radioactive source implants in the treatment of prostate cancer. A small radioactive source encapsulated in a titanium shell is used in this type of treatment. The radioisotopes used are generally 125I or 103Pd. Both of these isotopes have relatively short half-lives, 59.4 days and 16.99 days, respectively, and have low-energy emissions and a low dose rate. These factors make these sources well suited for this application, but the calibration of these sources poses significant metrological challenges. The current standard calibration technique involves the measurement of ionization in air to determine the source air-kerma strength. While this has proved to be an improvement over previous techniques, the method has been shown to be metrologically impure and may not be the ideal means of calbrating these sources. Calorimetric methods have long been viewed to be the most fundamental means of determining source strength for a radiation source. This is because calorimetry provides a direct measurement of source energy. However, due to the low energy and low power of the sources described above, current calorimetric methods are inadequate. This thesis presents work oriented toward developing novel methods to provide direct and absolute measurements of source power for low-energy low dose rate brachytherapy sources. The method is the first use of an actively temperature-controlled radiation absorber using the electrical substitution method to determine total contained source power of these sources. The instrument described operates at cryogenic temperatures. The method employed provides a direct measurement of source power. The work presented here is focused upon building a metrological foundation upon which to establish power-based calibrations of clinical-strength sources. To that end instrument performance has been assessed for these source strengths. The intent is to establish the limits of the current instrument to direct further work in this field. It has been found that for sources with powers above approximately 2 muW the instrument is able to determine the source power in agreement to within less than 7% of what is expected based upon the current source strength standard. For lower power sources, the agreement is still within the uncertainty of the power measurement, but the calorimeter noise dominates. Thus, to provide absolute calibration of lower power sources additional measures must be taken. The conclusion of this thesis describes these measures and how they will improve the factors that limit the current instrument. The results of the work presented in this thesis establish the methodology of active radiometric calorimetey for the absolute calibration of radioactive sources. The method is an improvement over previous techniques in that there is no reliance upon the thermal properties of the materials used or the heat flow pathways on the source measurements. The initial work presented here will help to shape future refinements of this technique to allow lower power sources to be calibrated with high precision and high accuracy.

Stump, Kurt E.

57

Thermodynamic properties of chlorite and berthierine derived from calorimetric measurements  

NASA Astrophysics Data System (ADS)

In the context of the deep waste disposal, we have investigated the respective stabilities of two iron-bearing clay minerals: berthierine ISGS from Illinois [USA; (Al0.975FeIII0.182FeII1.422Mg0.157Li0.035Mn0.002)(Si1.332Al0.668)O5(OH)4] and chlorite CCa-2 from Flagstaff Hill, California [USA; (Si2.633Al1.367)(Al1.116FeIII0.215Mg2.952FeII1.712Mn0.012Ca0.011)O10(OH)8]. For berthierine, the complete thermodynamic dataset was determined at 1 bar and from 2 to 310 K, using calorimetric methods. The standard enthalpies of formation were obtained by solution-reaction calorimetry at 298.15 K, and the heat capacities were measured by heat-pulse calorimetry. For chlorite, the standard enthalpy of formation is measured by solution-reaction calorimetry at 298.15 K. This is completing the entropy and heat capacity obtained previously by Gailhanou et al. (Geochim Cosmochim Acta 73:4738-4749, 2009) between 2 and 520 K, by using low-temperature adiabatic calorimetry and differential scanning calorimetry. For both minerals, the standard entropies and the Gibbs free energies of formation at 298.15 K were then calculated. An assessment of the measured properties could be carried out with respect to literature data. Eventually, the thermodynamic dataset allowed realizing theoretical calculations concerning the berthierine to chlorite transition. The latter showed that, from a thermodynamic viewpoint, the main factor controlling this transition is probably the composition of the berthierine and chlorite minerals and the nature of the secondary minerals rather than temperature.

Blanc, Philippe; Gailhanou, Hélène; Rogez, Jacques; Mikaelian, Georges; Kawaji, Hitoshi; Warmont, Fabienne; Gaboreau, Stéphane; Grangeon, Sylvain; Grenèche, Jean-Marc; Vieillard, Philippe; Fialips, Claire I.; Giffaut, Eric; Gaucher, Eric C.; Claret, F.

2014-09-01

58

Calorimetric and computational study of the thermochemistry of phenoxyphenols.  

PubMed

Thermodynamic properties of 3- and 4-phenoxyphenol have been determined by using a combination of calorimetric and effusion techniques as well as by high-level ab initio molecular orbital calculations. The standard (p° = 0.1 MPa) molar enthalpies of formation in the condensed and gas states, ?(f)H(m)°(cr or l) and ?(f)H(m)°(g), at T = 298.15 K, of 3- and 4-phenoxyphenol were derived from their energies of combustion in oxygen, measured by a static bomb calorimeter, and from the enthalpies of vaporization or sublimation derived respectively by Calvet microcalorimetry for the 3-phenoxyphenol and by Knudsen effusion technique for the 4-phenoxyphenol. The theoretically estimated gas-phase enthalpies of formation were calculated from high-level ab initio molecular orbital calculations at the G3(MP2)//B3LYP level of theory. Furthermore, this composite approach was also used to obtain information about the gas-phase acidities, gas-phase basicities, proton and electron affinities, adiabatic ionization enthalpies, and, finally, O?H bond dissociation enthalpies. The good agreement between the G3MP2B3-derived values and the experimental gas-phase enthalpies of formation for the 3- and 4-phenoxyphenol gives confidence to the estimate concerning the 2-phenoxyphenol isomer, which was not experimentally studied, and to the estimates concerning the radical and the anion. Additionally, the experimental values of gas-phase enthalpies of formation were also compared with estimates based on the empirical scheme developed by Cox. PMID:21486007

Ribeiro da Silva, Manuel A V; Lobo Ferreira, Ana I M C; Cimas, Álvaro

2011-05-20

59

Genetic analysis of the presumptive blood from Louis XVI, King of France.  

PubMed

A text on a pyrographically decorated gourd dated to 1793 explains that it contains a handkerchief dipped with the blood of Louis XVI, king of France, after his execution. Biochemical analyses confirmed that the material contained within the gourd was blood. The mitochondrial DNA (mtDNA) hypervariable region 1 (HVR1) and 2 (HVR2), the Y-chromosome STR profile, some autosomal STR markers and a SNP in HERC2 gene associated to blue eyes, were retrieved, and some results independently replicated in two different laboratories. The uncommon mtDNA sequence retrieved can be attributed to a N1b haplotype, while the novel Y-chromosome haplotype belongs to haplogroup G2a. The HERC2 gene showed that the subject analyzed was a heterozygote, which is compatible with a blue-eyed person, as king Louis XVI was. To confirm the identity of the subject, an analysis of the dried heart of his son, Louis XVII, could be undertaken. PMID:20940110

Lalueza-Fox, Carles; Gigli, Elena; Bini, Carla; Calafell, Francesc; Luiselli, Donata; Pelotti, Susi; Pettener, Davide

2011-11-01

60

Astronomical Data Analysis Software and Systems XVI D1.1 ASP Conference Series, Vol. XXX, 2006  

E-print Network

Astronomical Data Analysis Software and Systems XVI D1.1 ASP Conference Series, Vol. XXX, 2006 R, Durham University, South Road, Durham DH1 3LE, UK Malcolm J. Currie CCLRC Rutherford Appleton Laboratory Physics Laboratory, Bristol University, Tyndall Avenue, Bristol, BS8 1TL, UK Abstract. The GAIA 1

Taylor, Mark

61

David Rudd, ed. The Routledge Companion to Children's Literature, Routledge, 2009. xvi + 320 pp. $32.95 (hardcover). ISBN 9780415472715.  

E-print Network

, literature written by children, writings by parents for their own children, oral tradition, poetry, and playsDavid Rudd, ed. The Routledge Companion to Children's Literature, Routledge, 2009. xvi + 320 pp. $32.95 (hardcover). ISBN 9780415472715. Reviewed by Ernest Davis Children's literature has at least

Davis, Ernest

62

Paper to XVI IMEKO World Congress 2000, 25-28 Sept. 2000, Vienna REFRACTION INFLUENCE ANALYSIS AND  

E-print Network

Paper to XVI IMEKO World Congress 2000, 25-28 Sept. 2000, Vienna REFRACTION INFLUENCE ANALYSIS AND INVESTIGATIONS ON AUTOMATED ELIMINATION OF REFRACTION EFFECTS ON GEODETIC MEASUREMENTS B. Böckem1 , P. Flach1 , A of Geodesy and Photogrammetry 2 Institute of Geography Abstract: Refraction effects are generally caused

63

The Hydrogen Bonding of Cytosinewith Guanine:Calorimetric and`H-NMR Analysis  

E-print Network

The Hydrogen Bonding of Cytosinewith Guanine:Calorimetric and`H-NMR Analysis of the Molecular of hydrogen-bondformation between guanine (G) and cytusine (C) in o-dichloro- benzene and in chloroformat 25°C forming hydrogen bonds. Consequently, hydrogen-bond formation in our system is primarily between the bases

Williams, Loren

64

Metal–carbon bond energies for adsorbed hydrocarbons from calorimetric data  

Microsoft Academic Search

Single crystal adsorption calorimetry (SCAC) is a powerful new method for measuring adsorption and reaction energies. Particularly for hydrocarbons, where little or no information is available from either experiment or theory on well-defined surfaces, this method can provide crucially needed information. Assignment of the measured calorimetric heats to the appropriate surface reaction yields directly reaction heats and heats of formation

Heike Gross; Charles T. Campbell; David A. King

2004-01-01

65

First Calorimetric Measurement of OI-line in the Electron Capture Spectrum of $^{163}$Ho  

E-print Network

The isotope $^{163}$Ho undergoes an electron capture process with a recommended value for the energy available to the decay, $Q_{\\rm EC}$, of about 2.5 keV. According to the present knowledge, this is the lowest $Q_{\\rm EC}$ value for electron capture processes. Because of that, $^{163}$Ho is the best candidate to perform experiments to investigate the value of the electron neutrino mass based on the analysis of the calorimetrically measured spectrum. We present for the first time the calorimetric measurement of the atomic de-excitation of the $^{163}$Dy daughter atom upon the capture of an electron from the 5s shell in $^{163}$Ho, OI-line. The measured peak energy is 48 eV. This measurement was performed using low temperature metallic magnetic calorimeters with the $^{163}$Ho ion implanted in the absorber. We demonstrate that the calorimetric spectrum of $^{163}$Ho can be measured with high precision and that the parameters describing the spectrum can be learned from the analysis of the data. Finally, we discuss the implications of this result for the Electron Capture $^{163}$Ho experiment, ECHo, aiming to reach sub-eV sensitivity on the electron neutrino mass by a high precision and high statistics calorimetric measurement of the $^{163}$Ho spectrum.

P. C. -O. Ranitzsch; C. Hassel; M. Wegner; S. Kempf; A. Fleischmann; C. Enss; L. Gastaldo; A. Herlert; K. Johnston

2014-08-30

66

Calorimetric measurements of heat of sorption in polymer films: A molecular modeling and experimental study  

Microsoft Academic Search

We report a combined molecular modeling and experimental effort to predict and measure the heat of sorption of target molecules in a polymer film. The primary focus of this work is to demonstrate and validate the applicability of molecular modeling techniques as a predictive tool to evaluate polymeric sensing films for micro-calorimetric chemical sensor applications. In the current investigation, molecular

A. V. Shevade; M. A. Ryan; M. L. Homer; A. K. Kisor; K. S. Manatt; B. Lin; J.-P. Fleurial; A. M. Manfreda; S.-P. S. Yen

2005-01-01

67

Calorimetric detection of the conical THz radiation from femtosecond laser filaments in air  

E-print Network

1 Calorimetric detection of the conical THz radiation from femtosecond laser filaments in air terahertz (THz) emission from a femtosecond laser filament in air is measured with a bolometric detector and a set of filters, confirming that the main part of the emission lies between 0.5 and 3 THz

Paris-Sud XI, Université de

68

Calorimetric investigations on thermoregula-tion and growth of wax moth larvae (Galleria  

E-print Network

Calorimetric investigations on thermoregula- tion and growth of wax moth larvae (Galleria mellonella) The larvae of the wax moth Galleria mellonella are living in honeybee colonies where they feed on wax, honey, pollen and other organic matter. Mass-invasions of larvae can occur in weak bee colonies

Paris-Sud XI, Université de

69

Low temperature sugar-water equilibrium curve by a rapid calorimetric method  

Microsoft Academic Search

A simple rapid enthalpic method based upon a unique calorimetric measurement was developed and applied to sugar solutions at low temperatures to determine the amount of unfreezable water. The experimental results were in good agreement with those obtained by the usual freezing point depression method. The experimental data were also used to test the validity of several literature semi-empirical models

V. Hoff; S CORRERA

1995-01-01

70

Calorimetric determination of the enzyme activity immobilised on macroporous glass membranes  

Microsoft Academic Search

A direct method for the determination of the catalytic activity of immobilised enzymes by use of a miniaturised calorimeter is presented. The possibilities and advantages of the calorimetric method are demonstrated by investigations with catalase immobilised on macroporous glass membranes as model enzyme. The investigated enzyme carrier systems are characterised by a high catalytic activity, a marked long-term stability and

Hagen Graebner; Regina Hüttl; Gert Wolf

2002-01-01

71

Enthalpies of formation of the Al–Ni intermetallic compounds  

Microsoft Academic Search

The Al–Ni system has been investigated by direct reaction calorimetry at high temperatures. Enthalpies of formation of the intermetallic compounds AlNi3, AlNi, Al3Ni2, and Al3Ni were determined and compared with the available experimental values based on calorimetric and emf measurements and with the calculated values from theoretical models. X-ray powder diffraction (XRD) and electron probe microanalysis (EPMA) were used to

F. Z Chrifi-Alaoui; M Nassik; K Mahdouk; J. C Gachon

2004-01-01

72

PREFACE: XVI International Youth Scientific School 'Actual Problems of Magnetic Resonance and its Applications'  

NASA Astrophysics Data System (ADS)

In 1997, A S Borovik-Romanov, the Academician of RAS, and A V Aganov, the head of the Physics Department of Kazan State University, suggested that the 'School of Magnetic Resonance', well known in the Soviet Union, should recommence and be regularly held in Kazan. This school was created in 1968 by G V Scrotskii, the prominent scientist in the field of magnetic resonance and the editor of many famous books on magnetic resonance (authored by A Abragam, B. Bleaney, C. Slichter, and many others) translated and edited in the Soviet Union. In 1991 the last, the 12th School, was held under the supervision of G V Scrotskii. Since 1997, more than 600 young scientists, 'schoolboys', have taken part in the School meetings, made their oral reports and participated in heated discussions. Every year a competition among the young scientist takes place and the Program Committee members name the best reports, the authors of which are invited to prepare full-scale scientific papers. The XVI International Youth Scientific School 'Actual problems of the magnetic resonance and its application' in its themes is slightly different from previous ones. A new section has been opened this year: Coherent Optics and Optical Spectroscopy. Many young people have submitted interesting reports on optical research, many of the reports are devoted to the implementation of nanotechnology in optical studies. The XVI International Youth Scientific School has been supported by the Program of development of Kazan Federal University. It is a pleasure to thank the sponsors (BRUKER Ltd, Moscow, the Russian Academy of Science, the Dynasty foundation of Dmitrii Zimin, Russia, Russian Foundation for Basic Research) and all the participants and contributors for making the International School meeting possible and interesting. A V Dooglav, M Kh Salakhov and M S Tagirov The Editors

Salakhov, M. Kh; Tagirov, M. S.; Dooglav, A. V.

2013-12-01

73

Calorimetric effects during the ? ? ? transformation in Fe-Ni-Ti metastable alloys  

NASA Astrophysics Data System (ADS)

A calorimetric study of the reverse ? ? ? transformation has been carried out in five metastable Fe-Ni-Ti alloys. The amount of the ? phase in the initial samples is more than 50%. The exothermic processes of the decomposition of the ? and ? phases exceed the endothermic reactions of formation of the reverted austenite upon heating to the midpoint of the temperature interval of the reverse ? ? ? transformation. In the middle part of the interval in which the maximum rate of the transformation is recorded by the magnetometric method, the calorimetric curve does not exhibit thermal effects. This disagreement indicates the complex character of the transformation. At the finishing stage of the ? ? ? transformation, there is clearly detected an endothermic reaction.

Zemtsova, N. D.; Eremina, M. A.; Zavalishin, V. A.

2012-05-01

74

An Improved Formulation for Calorimetric Emittance Testing of Spacecraft Thermal Control Coatings  

NASA Technical Reports Server (NTRS)

Spacecraft often really heavily on passive thermal control to maintain operating temperature. An important parameter in the spacecraft heat balance equation is the emittance of thermal control coatings as a function of coating temperature. One method for determining the emittance of spacecraft thermal control from elevated temperature to cryogenic temperatures relies on a calorimetric technique. The fundamental equation governing this test method can be found in numerous places in the literature and although it generally provides reasonable results, its formulation is based on a conceptual flaw that only becomes apparent when the sample temperature approaches the wall temperature during testing. This paper investigates the cause for this error and develops the correct formulation for calorimetric emittance testing. Experimental data will also be presented that illustrates the difference between the two formulations and the resulting difference in the calculated emittance.

Kauder, Lonny R.

2008-01-01

75

An Improved Formulation for Calorimetric Emittance Testing of Spacecraft Thermal Control Coatings  

NASA Astrophysics Data System (ADS)

Spacecraft often rely heavily on passive thermal control to maintain operating temperature. An important parameter in the spacecraft heat balance equation is the emittance of thermal control coatings as a function of coating temperature. One method for determining the emittance of spacecraft thermal control from elevated temperature to cryogenic temperatures relies on a calorimetric technique. The fundamental equation governing this test method can be found in numerous places in the literature and although it generally provides reasonable results, its formulation is based on a conceptual flaw that only becomes apparent when the sample temperature approaches the wall temperature during testing. This paper investigates the cause for this error and develops the correct formulation for calorimetric emittance testing. Experimental data will also be presented that illustrates the difference between the two formulations and the resulting difference in the calculated emittance.

Kauder, Lonny R.

2009-01-01

76

Calorimetric studies of hydrophobic interactions of alkanols in concentrated aqueous solutions of glucose  

Microsoft Academic Search

Calorimetric measurements were carried out at 298K on concentrated aqueous solutions of glucose, ranging from 0 to 5molkg?1, containing alkan-1-ols, alkane-1,2-diols and alkane-?,?-diols from C2 to C7. The purpose of this study is to obtain more information about the influence of glucose on hydrophobic hydration and interactions. The pair-wise interaction coefficients of the virial expansion of the excess enthalpies were

Giuseppina Castronuovo; Vittorio Elia; Marcella Niccoli; Filomena Velleca

2002-01-01

77

Calorimetric method of ac loss measurement in a rotating magnetic field  

Microsoft Academic Search

A method is described for calorimetric ac-loss measurements of high-Tc superconductors (HTS) at 80 K. It is based on a technique used at 4.2 K for conventional superconducting wires that allows an easy loss measurement in parallel or perpendicular external field orientation. This paper focuses on ac loss measurement setup and calibration in a rotating magnetic field. This experimental setup

P. K. Ghoshal; T. A. Coombs; A. M. Campbell

2010-01-01

78

Effect of chilling on calorimetric responses of dormant vegetative apple buds  

Microsoft Academic Search

Chilling exposure is important in apple buds to overcome dormancy. The objective of this work was to determine the effect of different chilling treatments on apple bud calorimetric responses. One-year-old Golden Delicious trees were kept in a controlled temperature chamber at 4°C for up to 1600h. At 200h intervals, five trees were transferred to forcing conditions at 25°C. Isothermal calorimetry

A. A Gardea; E Carvajal-Millán; J. A Orozco; V. M Guerrero; J Llamas

2000-01-01

79

Calorimetric determinations and theoretical calculations of polymorphs of thalidomide  

NASA Astrophysics Data System (ADS)

The analysis of the thermograms of thalidomide obtained for the two reported polymorphs ? and ? by differential scanning calorimetry (DSC) shows some inconsistencies that are discussed in the present work. The conception of a new polymorph form, named ? ?, allowed us to explain the observed thermal behavior more satisfactorily. This new polymorph shows enantiotropy with both ? and ? polymorphs, reflected in the unique endotherm obtained in the DSC-thermograms, when a heating rate of 10 °C/min is applied. Several additional experiments, such as re-melting of both polymorph forms, showed that there is indeed a new polymorph with an endotherm located between the endotherms of ? and ?. IR, Raman, and powder X-ray permit us to characterize the isolated compound, resulting from the re-melting of both polymorph forms. Mechanical calculations were performed to elucidate the conformations of each polymorph, and ab initio quantum chemical calculations were performed to determine the energy of the more stable conformers and the spatial cell energy for both polymorphs ? and ?. These results suggested a possible conformation for the newly discovered polymorph ? ?.

Lara-Ochoa, F.; Pérez, G. Espinosa; Mijangos-Santiago, F.

2007-09-01

80

[Sanitary control of communicable diseases in Hispanic America in the XVI, XVII, and XVIII centuries].  

PubMed

In each time and each place, man has avoided diseases, has tried to limit diffusion of diseases. The purpose of this article was to present in a general manure the measures taken in Hispano America during colonial times to control communicable diseases. The main problems of health during the XVI, XVII, and XVIII centuries, in Hispano American region were communicable diseases. Practices to avoid them derived from observation, control measures referred to stay away from the contagious places, and to isolate sick persons by means of quarantine, and implied some epidemiologic surveillance. The supply of safe drinking water, sewage disposal systems and sanitary control of food were not habitual practices; garbage, residuals, and waste collection were not opportune, This favored the existence of vectors-insects and animals. Domestic waste did not go away in a timely fashion, it allowed to accumulate excreta and waste near houses. In some places, the were measures related to water supply, excreta disposal, handling of dead bodies, and environmental sanitation. It was believed that with prayers and processions, prevalent diseases could be avoided. Demographic information, data on mortality, births, and morbidity, were irregular and incompletes, some data were compiled in parishes: physicians should inform and notify the governmental medical board, which regulated medicine and public heath who the cared for an action carried out only as and exception. Compiled data had no clear medical or sanitary use. PMID:14723058

Fajardo-Ortiz, Guillermo; Ferrer-Burgos, Yolloxóchitl

2003-01-01

81

Calorimetric method for measuring high ultrasonic power using water as a heating material  

NASA Astrophysics Data System (ADS)

The present study shows the calorimetric method for measuring high ultrasonic power using water as the heating material. In recent years, at the National Metrology Institute of Japan (NMIJ), an ultrasonic power primary standard of from 1 mW to 15 W has been established by the radiation force balance (RFB) method. Conventionally, the RFB method is widely used for ultrasonic power measurement, but this method is not suitable for very high power measurement due to thermal damages to the absorbing targets. High power ultrasonic standards, however, are being required by medical HITU measurements and in the sonochemistry industry. In order to meet these requirements, we have started to develop an ultrasonic power standard between 15 W and 200 W. Our final goal is an ultrasonic power standard of up to 500 W. The calorimetric method is an alternative ultrasonic power measurement method to the RFB method. We have adopted this method and use water as the heating material. Water has excellent features as a standard material, because the physical properties of water are well known. In the present study, we present an experimental system and the results for an ultrasonic power standard of up to 100 W. The measured ultrasonic power agreed well with the NMIJ primary standard up to 25 W.

Kikuchi, T.; Uchida, T.

2011-02-01

82

Calorimetric Thermoelectric Gas Sensor for the Detection of Hydrogen, Methane and Mixed Gases  

PubMed Central

A novel miniaturized calorimeter-type sensor device with a dual-catalyst structure was fabricated by integrating different catalysts on the hot (Pd/?-Al2O3) and cold (Pt/?-Al2O3) ends of the device. The device comprises a calorimeter with a thermoelectric gas sensor (calorimetric-TGS), combining catalytic combustion and thermoelectric technologies. Its response for a model fuel gas of hydrogen and methane was investigated with various combustor catalyst compositions. The calorimetric-TGS devices detected H2, CH4, and a mixture of the two with concentrations ranging between 200 and 2000 ppm at temperatures of 100–400 °C, in terms of the calorie content of the gases. It was necessary to reduce the much higher response voltage of the TGS to H2 compared to CH4. We enhanced the H2 combustion on the cold side so that the temperature differences and response voltages to H2 were reduced. The device response to H2 combustion was reduced by 50% by controlling the Pt concentration in the Pt/?-Al2O3 catalyst on the cold side to 3 wt%. PMID:24818660

Park, Nam-Hee; Akamatsu, Takafumi; Itoh, Toshio; Izu, Noriya; Shin, Woosuck

2014-01-01

83

Calorimetric, thermomechanical, and rheological characterizations of bulk glass-forming Pd40Ni40P20  

NASA Astrophysics Data System (ADS)

Calorimetric, thermomechanical, and rheological properties of undercooled liquid Pd40Ni40P20 were determined within a wide temperature range above the glass transition. The concept of the limiting fictive temperature was applied to the entire set of measurements to compare the different properties adequately. It was found that an equilibrium state of a sample that is defined by its calorimetric glass temperature corresponds to a similar equilibrium state for the specific volume and for the shear viscosity as well. The Kauzmann temperature as one of the most important material characteristics concerning the glass transition could be determined with high accuracy leading to the evaluation of the free volume persistent in the samples. Viscosity values of the liquid extending over a range of about nine orders in magnitude could be described best by the free volume theory evaluated by Cohen and Grest, provided that experimentally obtained parameters were used for the calculations. The comparison between nonequilibrium measurements at isochronous heating and model calculations in the framework of bimolecular reaction kinetics shows that good agreement can be achieved using thermodynamic parameters that have been obtained from equilibrium measurements. However, systematic deviations indicate also the limitations of the model that are related to the intrinsic dynamic heterogeneity of the vitreous state.

Wilde, G.; Görler, G. P.; Willnecker, R.; Fecht, H. J.

2000-02-01

84

Calorimetric method of ac loss measurement in a rotating magnetic field  

NASA Astrophysics Data System (ADS)

A method is described for calorimetric ac-loss measurements of high-Tc superconductors (HTS) at 80 K. It is based on a technique used at 4.2 K for conventional superconducting wires that allows an easy loss measurement in parallel or perpendicular external field orientation. This paper focuses on ac loss measurement setup and calibration in a rotating magnetic field. This experimental setup is to demonstrate measuring loss using a temperature rise method under the influence of a rotating magnetic field. The slight temperature increase of the sample in an ac-field is used as a measure of losses. The aim is to simulate the loss in rotating machines using HTS. This is a unique technique to measure total ac loss in HTS at power frequencies. The sample is mounted on to a cold finger extended from a liquid nitrogen heat exchanger (HEX). The thermal insulation between the HEX and sample is provided by a material of low thermal conductivity, and low eddy current heating sample holder in vacuum vessel. A temperature sensor and noninductive heater have been incorporated in the sample holder allowing a rapid sample change. The main part of the data is obtained in the calorimetric measurement is used for calibration. The focus is on the accuracy and calibrations required to predict the actual ac losses in HTS. This setup has the advantage of being able to measure the total ac loss under the influence of a continuous moving field as experienced by any rotating machines.

Ghoshal, P. K.; Coombs, T. A.; Campbell, A. M.

2010-07-01

85

Calorimetric method of ac loss measurement in a rotating magnetic field  

SciTech Connect

A method is described for calorimetric ac-loss measurements of high-T{sub c} superconductors (HTS) at 80 K. It is based on a technique used at 4.2 K for conventional superconducting wires that allows an easy loss measurement in parallel or perpendicular external field orientation. This paper focuses on ac loss measurement setup and calibration in a rotating magnetic field. This experimental setup is to demonstrate measuring loss using a temperature rise method under the influence of a rotating magnetic field. The slight temperature increase of the sample in an ac-field is used as a measure of losses. The aim is to simulate the loss in rotating machines using HTS. This is a unique technique to measure total ac loss in HTS at power frequencies. The sample is mounted on to a cold finger extended from a liquid nitrogen heat exchanger (HEX). The thermal insulation between the HEX and sample is provided by a material of low thermal conductivity, and low eddy current heating sample holder in vacuum vessel. A temperature sensor and noninductive heater have been incorporated in the sample holder allowing a rapid sample change. The main part of the data is obtained in the calorimetric measurement is used for calibration. The focus is on the accuracy and calibrations required to predict the actual ac losses in HTS. This setup has the advantage of being able to measure the total ac loss under the influence of a continuous moving field as experienced by any rotating machines.

Ghoshal, P. K. [Oxford Instruments NanoScience, Abingdon, Oxfordshire OX13 5QX (United Kingdom); Coombs, T. A.; Campbell, A. M. [Department of Engineering, Electrical Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom)

2010-07-15

86

Tricriticality near the smectic-A-smectic-C transition of a liquid crystal compound  

NASA Astrophysics Data System (ADS)

High-resolution calorimetric investigations have been carried out on the chiral and racemic versions of 4-(3-methyl-2-chloro-butanoyloxy)-4'-heptyloxybiphenyl. While the chiral compound shows a weakly first-order smectic-A-chiral-smectic-C transition, the racemic one exhibits a continuous smectic-A-smectic-C transition. The latter transition is found to be at a mean-field tricritical point, within our experimental resolution.

Liu, H. Y.; Huang, C. C.; Bahr, Ch.; Heppke, G.

1988-07-01

87

Do methane measurements from a laser detector and an indirect open-circuit respiration calorimetric chamber agree sufficiently closely?  

Microsoft Academic Search

In ruminant production, there is a need for inexpensive, convenient and practical methods for quantifying the amount of enteric methane produced by cows. The current study tested the level of agreement between a recently developed proprietary laser methane detector (LMD) and the indirect open-circuit respiration calorimetric chamber. The test was based on two different methods, these are: Pearson correlation and

M. G. G. Chagunda; T. Yan

2011-01-01

88

The Bayer Facts of Science Education XVI: "US STEM Workforce Shortage--Myth or Reality? Fortune 1000 Talent Recruiters on the Debate"  

ERIC Educational Resources Information Center

A major debate is currently underway in the USA about whether there is, in fact, a science, technology, engineering and mathematics (STEM) workforce shortage in the country or not. This is the subject of the "Bayer Facts of Science Education XVI: US STEM Workforce Shortage--Myth or Reality? Fortune 1000 Talent Recruiters on the Debate."…

Journal of Science Education and Technology, 2014

2014-01-01

89

'Gold bug' sheds new light on old question Page 1 Vol. XVI, Issue 41 for the Amherst campus of the University of Massachusetts August 24, 2001  

E-print Network

'Gold bug' sheds new light on old question Page 1 Vol. XVI, Issue 41 for the Amherst campus of the University of Massachusetts August 24, 2001 Go `Gold bug' sheds new light on old question Lovley uses pollution cleanup technology to explain gold deposits by Paula Hartman Cohen, News Office Staff Derek Lovley

Lovley, Derek

90

Idebenone loaded solid lipid nanoparticles: calorimetric studies on surfactant and drug loading effects.  

PubMed

In this study we prepared solid lipid nanoparticles (SLN), by the phase inversion temperature (PIT) method, using cetyl palmitate as solid lipid and three different non-ionic emulsifiers of the polyoxyethylene ethers family (ceteth-20, isoceteth-20, oleth-20). These SLN were loaded with different amount of idebenone (IDE), an antioxidant drug useful in the treatment of neurodegenerative diseases and skin oxidative damages. The differential scanning calorimetry (DSC) was employed to evaluate the effects of the different emulsifiers and the different amounts of drug loaded on the thermotropic behavior of SLN and to investigate how the drug was arranged into these nanoparticles. The IDE seemed to be located into different regions of the SLN depending on its concentration and on the surfactant used. The results of this study suggest that the calorimetric studies performed on SLN could provide valuable information to optimize SLN design and drug release from these carriers. PMID:24845103

Sarpietro, Maria Grazia; Accolla, Maria Lorena; Puglisi, Giovanni; Castelli, Francesco; Montenegro, Lucia

2014-08-25

91

Total hemispherical emittance measured at high temperatures by the calorimetric method  

SciTech Connect

A calorimetric vacuum emissometer (CVE) capable of measuring total hemispherical emittance of surfaces at elevated temperatures was designed, built, and tested. Several materials with a wide range of emittances were measured in the CVE between 773 to 923 K. These results were compared to values calculated from spectral emittance curves measured in a room temperature Hohlraum reflectometer and in an open-air elevated temperature emissometer. The results differed by as much as 0.2 for some materials but were in closer agreement for the more highly-emitting, diffuse-reflecting samples. The differences were attributed to temperature, atmospheric, and directional effects, and errors in the Hohlraum and emissometer measurements ({+-} 5 percent). The probable error of the CVE measurements was typically less than 1 percent.

DiFilippo, F. [Case Western Reserve Univ., Cleveland, OH (United States); Mirtich, M.J.; Banks, B.A. [Lewis Research Center, Cleveland, OH (United States); Stidham, C.; Kussmaul, M. [Cleveland State Univ., OH (United States)

1994-09-01

92

Specific volume study of a bulk metallic glass far below its calorimetrically determined glass transition temperature  

NASA Astrophysics Data System (ADS)

High-precision LASER dilatometry with a unique measurement setup was applied to the bulk metallic glass alloy Zr52.5Ti5Cu17.9Ni14.6Al10 (Vit105) for specific volume studies. Employing small temperature steps of ?T =5 and 10 K and long measurement times effective heating rates of the order of 10-2 K/min were realized and changes of the specific volume were measured with a resolution of ?V /V=10-6 down to 573 K. The temperature regime of these experiments is far below a calorimetrically determined glass transition of Tgcalor=659 K (5 K/min). The experimental results strongly support theoretical predictions for the existence of an ideal glass transition that was observed in this study at Tg=628 K for this bulk metallic glass model alloy.

Luckabauer, M.; Kühn, U.; Eckert, J.; Sprengel, W.

2014-05-01

93

a Calorimetric Study of the Precipitation Hardening Mechanisms in AN Al-Cu-Mg-Si Alloy  

NASA Astrophysics Data System (ADS)

The precipitation phenomena and the related hardening in an Al-Cu-Mg-Si alloy were studied by calorimetry, X-ray diffraction analysis and microhardness measurements. The main calorimetric peaks were identified to be due to ???, ?? and Q? phases precipitation. The hardening during aging at room temperature and 160°C, was respectively, explained by atomic clusters and GP zones formation and by GP zones and ???/?? phases coprecipitation. Although the mechanical properties variation during aging at 200°C is simple, the corresponding microstructural evolution is complex: on the basis of the DSC results, the increasing of microhardness values, is mainly due to the coprecipitation of GP zones and ???/?? phases, however, the maximum hardening is explained by the coexistence of ???/?? and ??? phases. Another important conclusion is that during aging at 160°C and 200°C, the ?? phase is essentially developed from GP zones.

Hayoune, Abdelali

2013-08-01

94

Rapid discrimination of DNA strands using an opto-calorimetric microcantilever sensor.  

PubMed

A rapid technique for quantitative detection and discrimination of DNA strands without using immobilized probe molecules is demonstrated using an opto-calorimetric, self-powered sensor based on a Pb(Zr(0.52)Ti(0.48))O3 (PZT) microcantilever. Microcalorimetric infrared (IR) spectroscopy provides excellent chemical selectivity based on the unique molecular vibrational characteristics of each nucleotide in the mid IR region. The piezoelectric and pyroelectric properties of the PZT microcantilever were exploited in the quantitative detection and discrimination of adsorbed DNA strands with their spectral characteristics. We report the unique spectral characteristics of different DNA nucleotides that are monitored by wavelength-dependent temperature variations for different relative molar ratio of each nucleotide. This approach offers a fast, label-free technique which is highly sensitive and selective for the detection of single nucleotide differences in DNA strands and has the potential to be used as a rapid prescreening biosensor for various biomolecules. PMID:25300415

Lee, Dongkyu; Hwang, Kyo Seon; Kim, Seonghwan; Thundat, Thomas

2014-12-21

95

Calorimetric determination of thermal parameters for the Li/BrCl in SOCl2 (BCX) chemistry  

NASA Technical Reports Server (NTRS)

The heat capacity of a Li-BCX DD-cell was found to be dependent on its state of charge by drop calorimetry measurements. The method of drop calorimetry involves measuring the energy (joules) gained or lost from a sample that is transferred from a bath at temperature A to one at temperature B. The thermoneutral potential is defined as the cell potential where the cell electrochemical reactions are neither exothermic nor endothermic. A Hart scientific calorimeter system, Model No. S77XX, designed for heat conduction calorimetry and drop calorimetry was used. Calorimetric analysis yielded a thermoneutral potential of 4.14 volts and a cell heat capacity dependent on the state of charge.

Darcy, Eric C.; Kalu, Eric E.; White, Ralph E.

1990-01-01

96

Total hemispherical emittance measured at high temperatures by the calorimetric method  

NASA Technical Reports Server (NTRS)

A calorimetric vacuum emissometer (CVE) capable of measuring total hemispherical emittance of surfaces at elevated temperatures was designed, built, and tested. Several materials with a wide range of emittances were measured in the CVE between 773 to 923 K. These results were compared to values calculated from spectral emittance curves measured in a room temperature Hohlraum reflectometer and in an open-air elevated temperature emissometer. The results differed by as much as 0.2 for some materials but were in closer agreement for the more highly-emitting, diffuse-reflecting samples. The differences were attributed to temperature, atmospheric, and directional effects, and errors in the Hohlraum and emissometer measurements (plus or minus 5 percent). The probable error of the CVE measurements was typically less than 1 percent.

Difilippo, Frank; Mirtich, Michael J.; Banks, Bruce A.; Stidham, Curtis; Kussmaul, Michael

1989-01-01

97

Calorimetric Determinations of the Heat and Products of Detonation for Explosives: October 1961 to April 1982  

NASA Astrophysics Data System (ADS)

This report is a compilation of heat-of-detonation and product-composition data obtained at Lawrence Livermore National Laboratory during the last 21 years. In each determination, a 25-g high-explosive charge was detonated in a bomb calorimeter; a complete calorimetric measurement was made in 1 to 2 h with a precision of 0.3%. Data were interpreted using thermodynamic and hydrodynamic computer calculations. For unconfined or lightly confined charges, the released energy is largely retained in the products, which are subsequently shocked considerably off the Chapman-Jouguet isentrope by reflections from the bomb wall. For heavily confined charges, the detonation energy is largely converted to kinetic and internal energy of the confining case, and the products expand with minimal reshock along the Chapman-Jouguet isentrope.

Ornellas, D. L.

1982-04-01

98

Transport and calorimetric studies on CeNi2Al3  

NASA Astrophysics Data System (ADS)

Transport and calorimetric properties of Kondo lattice system CeNi2Al3 are reported. CeNi2Al3 shows good agreement with Grand Kadowaki-Woods relation with degeneracy of the quasi-particle N=6. The nonmagnetic nature of CeNi2Al3 is evident from resistivity measurement even though magnetic elements Ce and Ni are present. Three signatures, deviation from the normal metallic behaviour in resistivity above 140 K, relatively low charge carrier concentration (1021 cm?3) and energy gap Eg~11.6 meV obtained from two band model shed light on the most basic notions related to the semimetal nature of CeNi2Al3.

Y, Sankararao; Shanmukharao Samatham, S.; D, Venkateshwarlu; Gangrade, Mohan; Ganesan, V.

2014-09-01

99

Calorimetric and spectroscopic studies of the thermotropic phase behavior of lipid bilayer model membranes composed of a homologous series of linear saturated phosphatidylserines.  

PubMed Central

The thermotropic phase behavior of lipid bilayer model membranes composed of the even-numbered, N-saturated 1,2-diacyl phosphatidylserines was studied by differential scanning calorimetry and by Fourier-transform infrared and (31)P-nuclear magnetic resonance spectroscopy. At pH 7.0, 0.1 M NaCl and in the absence of divalent cations, aqueous dispersions of these lipids, which have not been incubated at low temperature, exhibit a single calorimetrically detectable phase transition that is fully reversible, highly cooperative, and relatively energetic, and the transition temperatures and enthalpies increase progressively with increases in hydrocarbon chain length. Our spectroscopic observations confirm that this thermal event is a lamellar gel (L(beta))-to-lamellar liquid crystalline (L(alpha)) phase transition. However, after low temperature incubation, the L(beta)/L(alpha) phase transition of dilauroyl phosphatidylserine is replaced by a higher temperature, more enthalpic, and less cooperative phase transition, and an additional lower temperature, less enthalpic, and less cooperative phase transition appears in the longer chain phosphatidylserines. Our spectroscopic results indicate that this change in thermotropic phase behavior when incubated at low temperatures results from the conversion of the L(beta) phase to a highly ordered lamellar crystalline (L(c)) phase. Upon heating, the L(c) phase of dilauroyl phosphatidylserine converts directly to the L(alpha) phase at a temperature slightly higher than that of its original L(beta)/L(alpha) phase transition. Calorimetrically, this process is manifested by a less cooperative but considerably more energetic, higher-temperature phase transition, which replaces the weaker L(beta)/L(alpha) phase transition alluded to above. However, with the longer chain compounds, the L(c) phase first converts to the L(beta) phase at temperatures some 10-25 degrees C below that at which the L(beta) phase converts to the L(alpha) phase. Our results also suggest that shorter chain homologues form L(c) phases that are structurally related to, but more ordered than, those formed by the longer chain homologues, but that these L(c) phases are less ordered than those formed by other phospholipids. These studies also suggest that polar/apolar interfaces of the phosphatidylserine bilayers are more hydrated than those of other glycerolipid bilayers, possibly because of interactions between the polar headgroup and carbonyl groups of the fatty acyl chains. PMID:11023908

Lewis, R N; McElhaney, R N

2000-01-01

100

Concurrent calorimetric and interferometric studies of steady-state natural convection from miniaturized horizontal single plate-fin systems and plate-fin arrays  

Microsoft Academic Search

Concurrent calorimetric and interferometric studies have been conducted to investigate the effect that reduction of the base-plate\\u000a dimensions has on the steady-state performance of the rate of natural convection heat transfer from miniaturized horizontal\\u000a single plate-fin systems and plate-fin arrays. The effect was studied through comparison of the present results with those\\u000a of earlier relevant calorimetric, interferometric, or numerical studies.

Filino Harahap; Herry Lesmana; Poetro Lebdo Sambegoro

2010-01-01

101

Calorimetric determination of fragility in glass forming liquids: T(f) vs. T(g-onset) methods.  

PubMed

The calorimetric determination of the fragility m-index is compared using the T f and T g-onset methods for typical metallic and molecular glass forming systems of Pd39Ni10Cu30P21, glycerol, triacetin and propylene carbonate. The results are evaluated by referring to the standard m-values determined from the kinetic measurements of the viscosity or structural relaxation time in the supercooled liquid regimes. The m-indexes derived from the T f method are found to generally agree well with the kinetic measurements for all the systems. However, a large deviation is shown between the m-indexes calculated with the T g-onset method and the kinetic results for the fragile liquids of triacetin and propylene carbonate, indicating the calorimetric determination of the fragility m-indexes in terms of the T f method produces less uncertainty. PMID:24965151

Chen, Zeming; Li, Zijing; Zhang, Yaqi; Liu, Riping; Tian, Yongjun; Wang, Li-Min

2014-06-01

102

Calorimetric aspects of adsorption of pesticides 2,4- d , diuron and atrazine on a magadiite surface  

Microsoft Academic Search

H-magadiite was applied to remove the pesticides 2,4-d, diuron, and atrazine from water. The H-magadiite containing herbicides adsorbed were investigated by FTIR, DRX, N2 adsorption and desorption isotherms, and surface area. Calorimetric studies were carried out to determine the heat of interaction\\u000a between pesticides and magadiite. It was possible to ride the cycle of interaction of magadiite–pesticide for a better

Alécio R. Nunes; Aline O. Moura; Alexandre G. S. Prado

103

Precipitation of guinier- preston zones in aluminum- magnesium; a calorimetric analysis of liquid-Quenched and solid-Quenched alloys  

Microsoft Academic Search

A calorimetric analysis of precipitation in liquid-quenched (LQ; rapidly solidified) and solid-quenched (SQ; quenched after\\u000a solution heat treatment) AlMg alloys was made. Nonisothermal annealing (constant heating rate) experiments (differential scanning\\u000a calorimetry) were performed using specimens of various compositions (12 to 17 at. Pct Mg) aged at fixed temperatures (293\\u000a to 353 K) during variable times (up to 3 years). Constraints

M. van Rooyen; J. A. Sinte Maartensdijk; E. J. Mittemeijer

1988-01-01

104

Precipitation of guinier- preston zones in aluminum- magnesium; a calorimetric analysis of liquid-Quenched and solid-Quenched alloys  

Microsoft Academic Search

A calorimetric analysis of precipitation in liquid-quenched (LQ; rapidly solidified) and solid-quenched (SQ; quenched after solution heat treatment) AlMg alloys was made. Nonisothermal annealing (constant heating rate) experiments (differential scanning calorimetry) were performed using specimens of various compositions (12 to 17 at. Pct Mg) aged at fixed temperatures (293 to 353 K) during variable times (up to 3 years). Constraints

M. van Rooyen; J. A. Sinte Maartensdijk; E. J. Mittemeijer

1988-01-01

105

Effect of Temperature on Xylanase II from Trichoderma reesei QM 9414: A Calorimetric, Catalytic, and Conformational Study  

PubMed Central

The secondary structure of xylanase II from Trichoderma reesei is lost in an apparent irreversible cooperative process as temperature is increased with a midpoint transition of 58.8 ± 0.1°C. The shift of the spectral centre of mass above 50°C is also apparently cooperative with midpoint transition of 56.3 ± 0.2°C, but the existence of two isofluorescent points in the fluorescence emission spectra suggests a non-two-state process. Further corroboration comes from differential scanning calorimetry experiments. At protein concentrations ?0.56?mg·mL?1 the calorimetric transition is reversible and the data were fitted to a non-two-state model and deconvoluted into six transitions, whereas at concentrations greater than 0.56?mg·mL?1 the calorimetric transition is irreversible with an exothermic contribution to the thermogram. The apparent Tm increased linearly with the scan rate according to first order inactivation kinetics. The effect of additives on the calorimetric transition of xylanase is dependent on their nature. The addition of sorbitol transforms reversible transitions into irreversible transitions while stabilizing the protein as the apparent Tm increases linearly with sorbitol concentration. d-Glucono-1,5-lactone, a noncompetitive inhibitor in xylanase kinetics, and soluble xylan change irreversible processes into reversible processes at high protein concentration. PMID:25276420

López, Gloria

2014-01-01

106

Calorimetric low temperature detectors for low-energetic heavy ions and their application in accelerator mass spectrometry  

NASA Astrophysics Data System (ADS)

The energy-sensitive detection of heavy ions with calorimetric low temperature detectors was investigated in the energy range of E =0.1-1 MeV/amu, commonly used for accelerator mass spectrometry (AMS). The detectors used consist of sapphire absorbers and superconducting aluminum transition edge thermometers operated at T ˜1.5 K. They were irradiated with various ion beams (C13,A197u,U238) provided by the VERA tandem accelerator in Vienna, Austria. The relative energy resolution obtained was ?E /E=(5-9)×10-3, even for the heaviest ions such as U238. In addition, no evidence for a pulse height defect was observed. This performance allowed for the first time to apply a calorimetric low temperature detector in an AMS experiment. The aim was to precisely determine the isotope ratio of U236/U238 for several samples of natural uranium, U236 being known as a sensitive monitor for neutron fluxes. Replacing a conventionally used detection system at VERA by the calorimetric detector enabled to substantially reduce background from neighboring isotopes and to increase the detection efficiency. Due to the high sensitivity achieved, a value of U236/U238=6.1×10-12 could be obtained, representing the smallest U236/U238 ratio measured at the time. In addition, we contributed to establishing an improved material standard of U236/U238, which can be used as a reference for future AMS measurements.

Kraft-Bermuth, S.; Andrianov, V. A.; Bleile, A.; Echler, A.; Egelhof, P.; Kiseleva, A.; Kiselev, O.; Meier, H. J.; Meier, J. P.; Shrivastava, A.; Weber, M.; Golser, R.; Kutschera, W.; Priller, A.; Steier, P.; Vockenhuber, C.

2009-10-01

107

Compound Interest  

NSDL National Science Digital Library

Albert Einstein called compound interest the 8th wonder of the world. Find out why compound interest and the time value of money are so important. What is Interest Click on the following link to read about the different types of interest. Loans and Interest So why learn about compound interest? Using time and interest to your advantage, you can make more money than you have ever dreamed of. See how the time value of ...

Ms. Riches

2007-10-16

108

A calorimetric study of the hydrolysis and peroxide complex formation of the uranyl(VI) ion.  

PubMed

The enthalpies of reaction for the formation of uranyl(vi) hydroxide {[(UO2)2(OH)2](2+), [(UO2)3(OH)4](2+), [(UO2)3(OH)5](+), [(UO2)3(OH)6](aq), [(UO2)3(OH)7](-), [(UO2)3(OH)8](2-), [(UO2)(OH)3](-), [(UO2)(OH)4](2-)} and peroxide complexes {[UO2(O2)(OH)](-) and [(UO2)2(O2)2(OH)](-)} have been determined from calorimetric titrations at 25 °C in a 0.100 M tetramethyl ammonium nitrate ionic medium. The hydroxide data have been used to test the consistency of the extensive thermodynamic database published by the Nuclear Energy Agency (I. Grenthe, J. Fuger, R. J. M. Konings, R. J. Lemire, A. B. Mueller, C. Nguyen-Trung and H. Wanner, Chemical Thermodynamics of Uranium, North-Holland, Amsterdam, 1992 and R. Guillaumont, T. Fanghänel, J. Fuger, I. Grenthe, V. Neck, D. J. Palmer and M. R. Rand, Update on the Chemical Thermodynamics of Uranium, Neptunium, Plutonium, Americium and Technetium, Elsevier, Amsterdam, 2003). A brief discussion is given about a possible structural relationship between the trinuclear complexes [(UO2)3(OH)n](6-n), n = 4-8. PMID:24301256

Zanonato, Pier Luigi; Di Bernardo, Plinio; Grenthe, Ingmar

2014-02-14

109

Oxindolealanine-62 lysozyme: equilibrium, calorimetric, and kinetic studies of the reaction with N-acetylglucosamine oligosaccharides.  

PubMed

Oxindolealanine-62 lysozyme, formed by reaction with N-bromosuccinimide and purified by using affinity chromatography, was examined in its binding of homologous oligosaccharides of N-acetylglucosamine and in its catalysis of hydrolysis and of transglycosylation of the hexasaccharide of N-acetylglucosamine. Equilibrium binding constants were determined by changes in absorbance or fluorescence associated with ligand binding. Enthalpies of binding were measured calorimetrically. The pattern of variation of delta Go and delta Ho of binding with ligand chain length and pH was different for oxindolealanine-62 lysozyme compared with native lysozyme. These results indicate that the interactions of the ABC region of the active site with substrates are substantially altered by Trp-62 oxidation, more than expected for loss only of the Trp-62 interactions. The partitioning of the glycosyl enzyme intermediate between reaction with a saccharide acceptor (transglycosylation) and reaction with water is unaffected by oxidation of Trp-62. Similarly, the pattern of cleavage of the hexasaccharide, predominantly to tetra- and disaccharide, is unaffected by oxidation of Trp-62. The 2000-fold slower rate of catalytic reaction (relative to free enzyme and substrate) apparently reflects a sterically hindered fit of the substrate into the active site of the modified enzyme and not a special catalytic importance of Trp-62. The geometry of the transition state for oligosaccharide hydrolysis is inferred to be the same for native and oxidized enzymes. PMID:7407080

Shrake, A; Rupley, J A

1980-08-19

110

Binding of the anticancer alkaloid sanguinarine with tRNA(phe): spectroscopic and calorimetric studies.  

PubMed

The interaction of the natural plant alkaloid and anticancer agent sanguinarine with tRNA(phe) has been investigated by spectroscopic and calorimetric techniques. Sanguinarine iminium binds to tRNA(phe) cooperatively; alkanolamine does not bind but in presence of large tRNA(phe) concentration, a conversion from alkanolamine to iminium occurs resulting in concomitant binding of the latter. The binding affinity of the iminium to tRNA(phe) obtained from isothermal titration calorimetry was of the order of 10(5)?M(-1), which is close to that evaluated from spectroscopy. The binding was driven largely by negative enthalpy and a smaller but favourable positive entropy change. The binding was dependent on the [Na(+)] concentration, but had a larger non-electrostatic contribution to the Gibbs energy. A small heat capacity value and the enthalpy-entropy compensation in the energetics of the interaction characterized the binding of the iminium form to tRNA(phe). This study confirms that the tRNA(phe) binding moiety is the iminium form of sanguinarine. PMID:22702734

Hossain, Maidul; Kabir, Ayesha; Suresh Kumar, Gopinatha

2012-01-01

111

Status and performance of the CALorimetric Electron Telescope (CALET) on the International Space Station  

NASA Astrophysics Data System (ADS)

The CALorimetric Electron Telescope (CALET) space experiment, currently under development by Japan in collaboration with Italy and the United States, will measure the flux of cosmic-ray electrons (including positrons) to 20 TeV, gamma rays to 10 TeV and nuclei with Z=1 to 40 up to 1,000 TeV during a two-year mission on the International Space Station (ISS), extendable to five years. These measurements are essential to search for dark matter signatures, investigate the mechanism of cosmic-ray acceleration and propagation in the Galaxy and discover possible astrophysical sources of high-energy electrons nearby the Earth. The instrument consists of two layers of segmented plastic scintillators for the cosmic-ray charge identification (CHD), a 3 radiation length thick tungsten-scintillating fiber imaging calorimeter (IMC) and a 27 radiation length thick lead-tungstate calorimeter (TASC). CALET has sufficient depth, imaging capabilities and excellent energy resolution to allow for a clear separation between hadrons and electrons and between charged particles and gamma rays. The instrument will be launched to the ISS within 2014 Japanese Fiscal Year (by the end of March 2015) and installed on the Japanese Experiment Module-Exposed Facility (JEM-EF). In this paper, we will review the status and main science goals of the mission and describe the instrument configuration and performance.

Adriani, O.; Akaike, Y.; Asaoka, Y.; Asano, K.; Bagliesi, M. G.; Bigongiari, G.; Binns, W. R.; Bongi, M.; Buckley, J. H.; Cassese, A.; Castellini, G.; Cherry, M. L.; Collazuol, G.; Ebisawa, K.; Di Felice, V.; Fuke, H.; Guzik, T. G.; Hams, T.; Hasebe, N.; Hareyama, M.; Hibino, K.; Ichimura, M.; Ioka, K.; Israel, M. H.; Javaid, A.; Kamioka, E.; Kasahara, K.; Katayose, Y.; Kataoka, J.; Kataoka, R.; Kawanaka, N.; Kitamura, H.; Kotani, T.; Krawczynski, H. S.; Krizmanic, J. F.; Kubota, A.; Kuramata, S.; Lomtadze, T.; Maestro, P.; Marcelli, L.; Marrocchesi, P. S.; Mitchell, J. W.; Miyake, S.; Mizutani, K.; Motz, H. M.; Moiseev, A. A.; Mori, K.; Mori, M.; Mori, N.; Munakata, K.; Murakami, H.; Nakagawa, Y. E.; Nakahira, S.; Nishimura, J.; Okuno, S.; Ormes, J. F.; Ozawa, S.; Palma, F.; Papini, P.; Rauch, B. F.; Ricciarini, S.; Sakamoto, T.; Sasaki, M.; Shibata, M.; Shimizu, Y.; Shiomi, A.; Sparvoli, R.; Spillantini, P.; Takahashi, I.; Takayanagi, M.; Takita, M.; Tamura, T.; Tateyama, N.; Terasawa, T.; Tomida, H.; Torii, S.; Tunesada, Y.; Uchihori, Y.; Ueno, S.; Vannuccini, E.; Wefel, J. P.; Yamaoka, K.; Yanagita, S.; Yoshida, A.; Yoshida, K.; Yuda, T.

2014-11-01

112

Electron energy and charge albedos - calorimetric measurement vs Monte Carlo theory  

SciTech Connect

A new calorimetric method has been employed to obtain saturated electron energy albedos for Be, C, Al, Ti, Mo, Ta, U, and UO/sub 2/ over the range of incident energies from 0.1 to 1.0 MeV. The technique was so designed to permit the simultaneous measurement of saturated charge albedos. In the cases of C, Al, Ta, and U the measurements were extended down to about 0.025 MeV. The angle of incidence was varied from 0/sup 0/ (normal) to 75/sup 0/ in steps of 15/sup 0/, with selected measurements at 82.5/sup 0/ in Be and C. In each case, state-of-the-art predictions were obtained from a Monte Carlo model. The generally good agreement between theory and experiment over this extensive parameter space represents a strong validation of both the theoretical model and the new experimental method. Nevertheless, certain discrepancies at low incident energies, especially in high-atomic-number materials, and at all energies in the case of the U energy albedos are not completely understood.

Lockwood, G.J.; Ruggles, L.E.; Miller, G.H.; Halbleib, J.A.

1981-11-01

113

Optical and Calorimetric Studies of Cholesterol-Rich Filamentous, Helical Ribbon and Crystal Microstructures  

SciTech Connect

Formation of biological self-assemblies at all scales is a focus of studies in fields ranging from biology to physics to biomimetics. Understanding the physico-chemical properties of these self-assemblies may lead to the design of bio-inspired structures and technological applications. Here we examine self-assembled filamentous, helical ribbon, and crystal microstructures formed in chemically defined lipid concentrate (CDLC), a model system for cholesterol crystallization in gallbladder bile. CDLC consists of cholesterol, bilayer-forming amphiphiles, micelle-forming amphiphiles, and water. Phase contrast and differential interference contrast (DIC) microscopy indicate the presence of three microstructure types in all samples studied, and allow for an investigation of the structures' unique geometries. Additionally, confocal microscopy is used for qualitative assessment of surface and internal composition. To complement optical observations, calorimetric (differential-scanning and modulation) experiments, provide the basis for an in-depth understanding of collective and individual thermal behavior. Observed ''transition'' features indicate clustering and ''straightening'' of helical ribbons into short, increasingly thickening, filaments that dissolve with increasing temperature. These results suggest that all microstructures formed in CDLC may coexist in a metastable chemical equilibrium. Further investigation of the CDLC thermal profile should uncover the process of cholesterol crystallization as well as the unique design and function of microstructures formed in this system.

Miroshnikova, Y. A.; Elsenbeck, M.; Zastavker, Y. V. [Franklin W. Olin College of Engineering, Needham, MA (United States); Kashuri, K; Iannacchione, G. S. [Worcester Polytechnic Institute, Worcester, MA (United States)

2009-04-19

114

Polybenzimidazole compounds  

DOEpatents

A PBI compound includes imidazole nitrogens at least a portion of which are substituted with a moiety containing a carbonyl group, the substituted imidazole nitrogens being bonded to carbon of the carbonyl group. At least 85% of the nitrogens may be substituted. The carbonyl-containing moiety may include RCO--, where R is alkoxy or haloalkyl. The PBI compound may exhibit a first temperature marking an onset of weight loss corresponding to reversion of the substituted PBI that is less than a second temperature marking an onset of decomposition of an otherwise identical PBI compound without the substituted moiety. The PBI compound may be included in separatory media. A substituted PBI synthesis method may include providing a parent PBI in a less than 5 wt % solvent solution. Substituting may use more than 5 equivalents in relation to the imidazole nitrogens to be substituted.

Klaehn, John R. (Idaho Falls, ID); Peterson, Eric S. (Idaho Falls, ID); Orme, Christopher J. (Shelley, ID); Jones, Michael G. (Chubbuck, ID); Wertsching, Alan K. (Idaho Falls, ID); Luther, Thomas A. (Idaho Falls, ID); Trowbridge, Tammy L. (Idaho Falls, ID)

2011-11-22

115

Organosulfur Compounds  

NSDL National Science Digital Library

Quiz questions from the organic chemistry question bank provide students with an excellent opportunity to review key concepts. This set of questions focuses on organosulfur compounds, with a special emphasis on thiols and sulfides.

Reich, Ieva

116

Polybenzimidazole compounds  

DOEpatents

A PBI compound that includes imidazole nitrogens, at least a portion of which are substituted with an organic-inorganic hybrid moiety. At least 85% of the imidazole nitrogens may be substituted. The organic-inorganic hybrid moiety may be an organosilane moiety, for example, (R)Me.sub.2SiCH.sub.2--, where R is selected from among methyl, phenyl, vinyl, and allyl. The PBI compound may exhibit similar thermal properties in comparison to the unsubstituted PBI. The PBI compound may exhibit a solubility in an organic solvent greater than the solubility of the unsubstituted PBI. The PBI compound may be included in separatory media. A substituted PBI synthesis method may include providing a parent PBI in a less than 5 wt % solvent solution. Substituting may occur at about room temperature and/or at about atmospheric pressure. Substituting may use at least five equivalents in relation to the imidazole nitrogens to be substituted or, preferably, about fifteen equivalents.

Klaehn, John R. (Idaho Falls, ID); Peterson, Eric S. (Idaho Falls, ID); Wertsching, Alan K. (Idaho Falls, ID); Orme, Christopher J. (Shelley, ID); Luther, Thomas A. (Idaho Falls, ID); Jones, Michael G. (Pocatello, ID)

2010-08-10

117

An IR and Calorimetric Investigation of the Structural, Crystal-Chemical and Thermodynamic Properties of Hydrogrossular  

NASA Astrophysics Data System (ADS)

The garnet class of phases is extremely broad in terms of composition and structural properties. Garnet is found in nature and various synthetic garnet phases have a number of important technical applications. There exist the rock-forming silicate garnets that are so widespread geologically. An additional class is given by the so-called "hydrogarnets" in which the tetrahedral site (Wyckoff position 24d) is empty. At relatively low temperatures there is complete solid solution between Ca3Al2Si3O12 and Ca3Al2H12O12, for example. The substitution mechanism can be written as O4H4 \\lrarr SiO4. The latter, pure OH-containing end-member, which has not been found in nature, is termed katoite/hydrogrossular. Its structure has been investigated by various workers by X-ray and neutron diffraction and by proton NMR, IR and Raman spectroscopic methods. At ambient conditions the structure has the "standard" garnet cubic symmetry of Ia-3d. At high pressures, and possibly at low temperatures, a different structure may occur. We measured the low temperature IR spectra and heat capacity of katoite in order to understand its structural, crystal-chemical and thermophysical properties. A sample of Ca3Al2H12O12 was synthesized hydrothermally in Au capsules at 250 °C and 3 kb water pressure. X-ray powder measurements show that about 98-99% katoite was obtained. Powder IR spectra were recorded between 298 K and 10 K. The measured spectra are considerably different in the high wavenumber region, where O-H stretching modes occur, between 298 K and 10 K. At room temperature the IR-active O-H band located around 3662 cm-1 is broad and it narrows and shifts to higher wavenumbers and also develops structure below about 80 K. Concomitantly, additional weak intensity O-H bands located around 3600 cm-1 begin to appear and they become sharper and increase in intensity with further decreases in temperature down to 10 K. The spectra indicate that the vibrational behavior of individual OH groups and their collective interactions measurably affect the lattice dynamic (i.e. thermodynamic) behavior. The low temperature heat capacity behavior was investigated with a commercially designed relaxation calorimeter between 5 and 300 K on a mg-sized sample. The heat capacity data are well behaved at T < 300 K and show a monotonic decrease in magnitude with decreasing temperature. A standard third-law entropy value of So = 421.7 ± 1.6 J/mol·K was calculated. Using this new calorimetric-based So value and published standard enthalpy of formation data for katoite, a calorimetric-based Gibbs free energy of formation at 298 K can be obtained as ?G°f = -5021.2 kJ/mol. The Cp data show no evidence for any phase transition as possibly expected by the change in OH-mode behavior with decreasing temperature. We have no explanation for the appearance of the additional modes. It is worth noting that the katoite crystal structure in terms of lattice dynamic or thermodynamic behavior should be thought of having OH groups and not O4H4 clusters or polyhedral units as is often written in the literature. The single crystallographic OH group in katoite shows very weak, if any, hydrogen bonding and the H atoms have large amplitudes of vibration. The weak H bonding controls the nature of low energy OH-related vibrations and this leads to its large So value.

Geiger, C. A.; Dachs, E.

2012-04-01

118

Energetics of carbohydrate binding to Momordica charantia (bitter gourd) lectin: an isothermal titration calorimetric study.  

PubMed

Physico-chemical and carbohydrate binding studies have been carried out on the Momordica charantia (bitter gourd) seed lectin (MCL). The lectin activity is maximal in the pH range 7.4-11.0, but decreases steeply below pH 7.0. The lectin activity is mostly unaffected in the temperature range 4-50 degrees C, but a sharp decrease is seen between 50 and 60 degrees C, which could be correlated to changes in the structure of the protein as seen by circular dichroism and fluorescence spectroscopy. Isothermal titration calorimetric studies show that the tetrameric MCL binds two sugar molecules and the binding constants (Kb), determined at 288.15 K, for various saccharides were found to vary between 7.3 x 10(3) and 1.52 x 10(4)M(-1). The binding reactions for all the saccharides investigated were essentially enthalpy driven, with the binding enthalpies (DeltaHb) at 288.15 K being in the range of -50.99 and -43.39 kJ mol(-1), whereas the contribution to the binding reaction from the entropy of binding was negative, with values of binding entropy (DeltaSb) ranging between -99.2 and -72.0 J mol(-1)K(-1) at 288.15 K. Changes in heat capacity (DeltaCp) for the binding of disaccharides, lactose and lactulose, were significantly larger in magnitude than those obtained for the monosaccharides, methyl-beta-D-galactopyranoside, and methyl-alpha-D-galactopyranoside, and could be correlated reasonably well with the surface areas of these ligands. Enthalpy-entropy compensation was observed for all the sugars studied, suggesting that water structure plays an important role in the overall binding reaction. CD spectroscopy indicates that carbohydrate binding does not lead to significant changes in the secondary and tertiary structures of MCL, suggesting that the carbohydrate binding sites on this lectin are mostly preformed. PMID:15820223

Sultan, Nabil Ali Mohammed; Swamy, Musti J

2005-05-01

119

Crop changes from the XVI century to the present in a hill/mountain area of eastern Liguria (Italy)  

PubMed Central

Background Chronological information on the composition and structure of agrocenoses and detailed features of land cover referring to specific areas are uncommon in ethnobotanical studies, especially for periods before the XIX century. The aim of this study was to analyse the type of crop or the characteristics of soil cover from the XVI century to the present. Methods This diachronic analysis was accomplished through archival research on the inventories of the Parish of St. Mary and those of the Municipality of Pignone and from recent surveys conducted in an area of eastern Liguria (Italy). Results Archival data revealed that in study area the primary means of subsistence during the last five centuries, until the first half of the XX century, was chestnuts. In the XVIII and XIX centuries, crop diversification strongly increased in comparison with previous and subsequent periods. In more recent times, the abandonment of agricultural practices has favoured the re-colonisation of mixed woodland or cluster-pine woodland. Conclusion Ancient documents in the ecclesiastic or municipal inventories can be a very useful tool for enhancing the knowledge of agricultural practice, as well as of subsistence methods favoured by local populations during a particular time and for reconstructing land use change over time. PMID:19361339

Gentili, Rodolfo; Gentili, Elio; Sgorbati, Sergio

2009-01-01

120

Determination of the activation energy spectrum of structural relaxation in metallic glasses using calorimetric and shear modulus relaxation data  

NASA Astrophysics Data System (ADS)

We consider two methods for reconstruction of the activation energy spectra of structural relaxation from calorimetric and shear modulus relaxation data. The methods are based on the assumption that structural relaxation of metallic glasses can be understood as a relaxation change of the concentration of frozen-in defects similar to dumbbell interstitials (interstitialcies) in simple crystals. For three Pd- and Zr-based glasses taken as an example, it is shown that both methods give nearly the same results. We calculated a decrease of the defect concentration and showed that the heat of structural relaxation per defect for all three glasses practically coincides with the theoretical value of the interstitialcy formation enthalpy.

Tsyplakov, A. N.; Mitrofanov, Yu. P.; Makarov, A. S.; Afonin, G. V.; Khonik, V. A.

2014-09-01

121

Investigation of ferroelectric phase transitions of water in nanoporous silicates in simultaneous electrical noise and calorimetric measurements  

NASA Astrophysics Data System (ADS)

The phase transitions of water in the nanoporous silicate materials SBA-15 and MCM-41 with an ordered system of cylindrical pores have been investigated. Measurements of low-frequency electrical noises (Barkhausen noises) in the frequency range of 1-100 Hz have been performed simultaneously with relative calorimetric measurements. It has been found that the voltage of electrical fluctuations increases approximately 100 times in the temperature range from -30 to -50°C, which is associated with the first-order and second-order ferroelectric phase transitions. It has been assumed that the ferroelectric ice XI can be formed in capillary pores of the materials under investigations.

Bordonskiy, G. S.; Orlov, A. O.

2014-08-01

122

Multipurpose Compound  

NASA Technical Reports Server (NTRS)

Specially formulated derivatives of an unusual basic compound known as Alcide may be the answer to effective treatment and prevention of the disease bovine mastitis, a bacterial inflammation of a cow's mammary gland that results in loss of milk production and in extreme cases, death. Manufactured by Alcide Corporation the Alcide compound has killed all tested bacteria, virus and fungi, shortly after contact, with minimal toxic effects on humans or animals. Alcide Corporation credits the existence of the mastitis treatment/prevention products to assistance provided the company by NERAC, Inc.

1983-01-01

123

Magnesium compounds  

USGS Publications Warehouse

Seawater and natural brines accounted for about 63% of US magnesium compounds production during 2000. Premier Services in Florida, Dow Chemical in Michigan, Martin Marietta Magnesia Specialties, and Rohm & Haas recovered dead-burned and caustic-calcined magnesias from seawater. And Premier Services' recoveries, in Nevada, were from magnasite.

Kramer, D.A.

2001-01-01

124

Calorimetric and spectroscopic studies of aminoglycoside binding to AT-rich DNA triple helices  

PubMed Central

Calorimetric and fluorescence techniques were used to characterize the binding of aminoglycosides-neomycin, paromomycin, and ribostamycin, with 5?-dA12-x-dT12-x-dT12-3? intramolecular DNA triplex (x = hexaethylene glycol) and poly(dA).2poly(dT) triplex. Our results demonstrate the following features: (1) UV thermal analysis reveals that the Tm for triplex decreases with increasing pH value in the presence of neomycin, while the Tm for the duplex remains unchanged. (2) The binding affinity of neomycin decreases with increased pH, although there is an increase in observed binding enthalpy. (3) ITC studies conducted in two buffers (sodium cacodylate and MOPS) yield the number of protonated drug amino groups (?n) as 0.29 and 0.40 for neomycin and paromomycin interaction with 5?-dA12-x-dT12-x-dT12-3?, respectively. (4) The specific heat capacity change (?Cp) determined by ITC studies is negative, with more negative values at lower salt concentrations. From 100 mM to 250 mM KCl, the ?Cp ranges from ?402 to ?60 cal/(mol K) for neomycin. At pH 5.5, a more positive ?Cp is observed, with a value of ?98 cal/(mol K) at 100 mM KCl. ?Cp is not significantly affected by ionic strength. (5) Salt dependence studies reveal that there are at least three amino groups of neomycin participating in the electrostatic interactions with the triplex. (6) FID studies using thiazole orange were used to derive the AC50 (aminoglycoside concentration needed to displace 50% of the dye from the triplex) values. Neomycin shows a seven fold higher affinity than paromomycin and eleven fold higher affinity than ribostamycin at pH 6.8. (7) Modeling studies, consistent with UV and ITC results, show the importance of an additional positive charge in triplex recognition by neomycin. The modeling and thermodynamic studies indicate that neomycin binding to the DNA triplex depends upon significant contributions from charge as well as shape complementarity of the drug to the DNA triplex Watson–Hoogsteen groove. PMID:20167243

Xi, Hongjuan; Kumar, Sunil; Dosen-Micovic, Ljiljana; Arya, Dev P.

2013-01-01

125

Calorimetric AC loss measurement of MgB2 superconducting tape in an alternating transport current and direct magnetic field  

NASA Astrophysics Data System (ADS)

Applications of MgB2 superconductors in electrical engineering have been widely reported, and various studies have been made to define their alternating current (AC) losses. However, studies on the transport losses with an applied transverse DC magnetic field have not been conducted, even though this is one of the favored conditions in applications of practical MgB2 tapes. Methods and techniques used to characterize and measure these losses have so far been grouped into ‘electrical’ and ‘calorimetric’ approaches with external conditions set to resemble the application conditions. In this paper, we present a new approach to mounting the sample and employ the calorimetric method to accurately determine the losses in the concurrent application of AC transport current and DC magnetic fields that are likely to be experienced in practical devices such as generators and motors. This technique provides great simplification compared to the pickup coil and lock-in amplifier methods and is applied to a long length (˜10 cm) superconducting tape. The AC loss data at 20 and 30 K will be presented in an applied transport current of 50 Hz under external DC magnetic fields. The results are found to be higher than the theoretical predictions because of the metallic fraction of the tape that contributes quite significantly to the total losses. The data, however, will allow minimization of losses in practical MgB2 coils and will be used in the verification of numerical coil models.

See, K. W.; Xu, X.; Horvat, J.; Cook, C. D.; Dou, S. X.

2012-11-01

126

Geant4 simulation of the Elekta XVI kV CBCT unit for accurate description of potential late toxicity effects of image-guided radiotherapy.  

PubMed

This paper describes the modelisation of the Elekta XVI Cone Beam Computed Tomography (CBCT) machine components with Geant4 and its validation against calibration data taken for two commonly used machine setups. Preliminary dose maps of simulated CBCTs coming from this modelisation work are presented. This study is the first step of a research project, GHOST, aiming to improve the understanding of late toxicity risk in external beam radiotherapy patients by simulating dose depositions integrated from different sources (imaging, treatment beam) over the entire treatment plan. The second cancer risk will then be derived from different models relating irradiation dose and second cancer risk. PMID:25415354

Brochu, F M; Burnet, N G; Jena, R; Plaistow, R; Parker, M A; Thomas, S J

2014-11-21

127

Magnesium compounds  

USGS Publications Warehouse

Seawater and natural brines accounted for about 60 percent of U.S. magnesium compounds production during 2002. Dead-burned and caustic-calcined magnesias were recovered from seawater by Premier Chemicals in Florida. They were also recovered from well brines in Michigan by Dow Chemical, Martin Marietta Magnesia Specialties and Rohm & Haas. And they were recovered from magnesite in Nevada by Premier Chemicals.

Kramer, D.A.

2003-01-01

128

Magnesium compounds  

USGS Publications Warehouse

In 2005, seawater and natural brines accounted for 51% of US magnesium compounds production. World magnesia production was estimated to be 14.5 Mt. Most of the production came from China, North Korea, Russia and Turkey. Although no specific production figures are available, Japan and the United States are estimated to account for almost one-half of the world's capacity from seawater and brines.

Kramer, D.A.

2006-01-01

129

Magnesium compounds  

USGS Publications Warehouse

Seawater and natural brines accounted for about 60% of US magnesium compounds production in 2001. Dead-burned and caustic-calcined magnesias were recovered from seawater in Florida by Premier Chemicals. They were also recovered from Michigan well brines by Dow Chemical, Martin Marietta Magnesia Specialties and Rohm & Haas. And Premier Chemicals recovered dead-burned and caustic-calcined magnesias from magnesite in Nevada. Reilly Industries and Great Salt Lake Minerals recovered magnesium chloride brines from the Great Salt Lake in Utah.

Kramer, D.A.

2002-01-01

130

Magnesium compounds  

USGS Publications Warehouse

Seawater and natural brines accounted for about 54 percent of U.S. magnesium compounds production in 2010. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties from well brines in Michigan. Caustic-calcined magnesia was recovered from seawater by Premier Magnesia in Florida, from well brines in Michigan by Martin Marietta and from magnesite in Nevada by Premier Magnesia. Intrepid Potash-Wendover and Great Salt Lake Minerals Corp. recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from seawater by SPI Pharma in Delaware and Premier Magnesia in Florida, and by Martin Marietta from its operation mentioned above.

Kramer, D.A.

2011-01-01

131

Magnesium compounds  

USGS Publications Warehouse

Seawater and natural brines accounted for about 40 percent of U.S. magnesium compounds production in 2009. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties from well brines in Michigan. Caustic-calcined magnesia was recovered from seawater by Premier Chemicals in Florida, from well brines in Michigan by Martin Marietta and from magnesite in Nevada by Premier Chemicals. Intrepid Potash-Wendover, and Great Salt Lake Minerals Corp. recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from seawater by SPI Pharma in Delaware and Premier Chemicals in Florida, and by Martin Marietta from its operation mentioned above.

Kramer, D.A.

2010-01-01

132

Magnesium compounds  

USGS Publications Warehouse

Seawater and natural brines accounted for about 52 percent of U.S. magnesium compounds production in 2006. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties from well brines in Michigan. Caustic-calcined magnesia was recovered from sea-water by Premier Chemicals in Florida; from well brines in Michigan by Martin Marietta and Rohm and Haas; and from magnesite in Nevada by Premier Chemicals. Intrepid Potash-Wendover and Great Salt Lake Minerals recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from brucite by Applied Chemical Magnesias in Texas, from seawater by SPI Pharma in Delaware and Premier Chemicals in Florida, and by Martin Marietta and Rohm and Haas from their operations mentioned above. About 59 percent of the magnesium compounds consumed in the United States was used for refractories that are used mainly to line steelmaking furnaces. The remaining 41 percent was consumed in agricultural, chemical, construction, environmental and industrial applications.

Kramer, D.A.

2007-01-01

133

Comparative dose evaluations between XVI and OBI cone beam CT systems using Gafchromic XRQA2 film and nanoDot optical stimulated luminescence dosimeters  

SciTech Connect

Purpose: To investigate the effect of energy (kVp) and filters (no filter, half Bowtie, and full Bowtie) on the dose response curves of the Gafchromic XRQA2 film and nanoDot optical stimulated luminescence dosimeters (OSLDs) in CBCT dose fields. To measure surface and internal doses received during x-ray volume imager (XVI) (Version R4.5) and on board imager (OBI) (Version 1.5) CBCT imaging protocols using these two types of dosimeters. Methods: Gafchromic XRQA2 film and nanoDot OSLD dose response curves were generated at different kV imaging settings used by XVI (software version R4.5) and OBI (software version 1.5) CBCT systems. The settings for the XVI system were: 100 kVp/F0 (no filter), 120 kVp/F0, and 120 kVp/F1 (Bowtie filter), and for the OBI system were: 100 kVp/full fan, 125 kVp/full fan, and 125 kVp/half fan. XRQA2 film was calibrated in air to air kerma levels between 0 and 11 cGy and scanned using reflection scanning mode with the Epson Expression 10000 XL flat-bed document scanner. NanoDot OSLDs were calibrated on phantom to surface dose levels between 0 and 14 cGy and read using the inLight{sup TM} MicroStar reader. Both dosimeters were used to measure in field surface and internal doses in a male Alderson Rando Phantom. Results: Dose response curves of XRQA2 film and nanoDot OSLDs at different XVI and OBI CBCT settings were reported. For XVI system, the surface dose ranged between 0.02 cGy in head region during fast head and neck scan and 4.99 cGy in the chest region during symmetry scan. On the other hand, the internal dose ranged between 0.02 cGy in the head region during fast head and neck scan and 3.17 cGy in the chest region during chest M20 scan. The average (internal and external) dose ranged between 0.05 cGy in the head region during fast head and neck scan and 2.41 cGy in the chest region during chest M20 scan. For OBI system, the surface dose ranged between 0.19 cGy in head region during head scan and 4.55 cGy in the pelvis region during spot light scan. However, the internal dose ranged between 0.47 cGy in the head region during head scan and 5.55 cGy in the pelvis region during spot light scan. The average (internal and external) dose ranged between 0.45 cGy in the head region during head scan and 3.59 cGy in the pelvis region during spot light scan. Both Gafchromic XRQA2 film and nanoDot OSLDs gave close estimation of dose (within uncertainties) in many cases. Though, discrepancies of up to 20%-30% were observed in some cases. Conclusions: Dose response curves of Gafchromic XRQA2 film and nanoDot OSLDs indicated that the dose responses of these two dosimeters were different even at the same photon energy when different filters were used. Uncertainty levels of both dosimetry systems were below 6% at doses above 1 cGy. Both dosimetry systems gave almost similar estimation of doses (within uncertainties) in many cases, with exceptions of some cases when the discrepancy was around 20%-30%. New versions of the CBCT systems (investigated in this study) resulted in lower imaging doses compared with doses reported on earlier versions in previous studies.

Giaddui, Tawfik; Cui Yunfeng; Galvin, James; Yu Yan; Xiao Ying [Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 (United States)

2013-06-15

134

Fun with Compound Words  

NSDL National Science Digital Library

Identify and create compound words We will be studying compound words! First we need to find out what a compound word is, go to this website and read about compound words.What is a compound word Now that you have read about compound words lets do some fun activities to help us review. First go to Compound word flashcards, here you will ...

Ms. Huggins

2012-04-12

135

Thermodynamic study of rhodamine 123-calf thymus DNA interaction: determination of calorimetric enthalpy by optical melting study.  

PubMed

In this paper, the interaction of rhodamine123 (R123) with calf thymus DNA has been studied using molecular modeling and other biophysical methods like UV-vis spectroscopy, fluoremetry, optical melting, isothermal titration calorimetry, and circular dichroic studies. Results showed that the binding energy is about -6 to -8 kcal/mol, and the binding process is favored by both negative enthalpy change and positive entropy change. A new method to determine different thermodynamic properties like calorimetric enthalpy and heat capacity change has been introduced in this paper. The obtained data has been crossed-checked by other methods. After dissecting the free-energy contribution, it was observed that the binding was favored by both negative hydrophobic free energy and negative molecular free energy which compensated for the positive free energies due to the conformational change loss of rotational and transitional freedom of the DNA helix. PMID:25383921

Masum, Abdulla Al; Chakraborty, Maharudra; Pandya, Prateek; Halder, Umesh Chandra; Islam, Md Maidul; Mukhopadhyay, Subrata

2014-11-20

136

Population and habitat on the feudal domain iria at the beginning of the XVIth century Eugen Ghita Populaie i habitat pe domeniul cetii iria la nceputul secolului al XVI lea  

E-print Network

Population and habitat on the feudal domain iria at the beginning of the XVIth century Eugen Ghita domeniul cetii iria la începutul secolului al XVI ­lea Eugen Ghi Abstract: The study ,,Population and habitat on the feudal domain iria at the beginning of the XVIth century Eugen Ghita Populaie i habitat pe

Paris-Sud XI, Université de

137

Thermochemistry of Bithiophenes and Thienyl Radicals. A Calorimetric and Computational Study  

NASA Astrophysics Data System (ADS)

The relative stabilities of 2,2'- and 3,3'-bithiophenes were evaluated by experimental thermochemistry and the results compared with data obtained from state of the art calculations, which were also extended to 2,3'-bithiophene. The standard (p° = 0.1 MPa) molar enthalpies of formation of crystalline 2,2'-bithiophene and 3,3'-bithiophene were calculated from the standard molar energies of combustion, in oxygen, to yield CO2 (g) and H2SO4·115H2O, measured by rotating-bomb combustion calorimetry at T = 298.15 K. The vapor pressures of these two compounds were measured as a function of temperature by Knudsen effusion mass-loss technique. The standard molar enthalpies of sublimation, at T = 298.15 K, were derived from the Clausius-Clapeyron equation. The experimental values were used to calculate the standard (p° = 0.1 MPa) enthalpies of formation of the title compounds in the gaseous phase; the results were analyzed and interpreted in terms of enthalpic increments and molecular structure. Standard ab initio molecular orbital calculations at the G3(MP2)//B3LYP level were performed. Enthalpies of formation, using homodesmotic reactions, were calculated and compared with experimental data. The computational study was also extended to the isomeric compound 2,3'-bithiophene. Detailed inspections of the molecular and electronic structures of the compounds studied were carried out. Finally, bond dissociation enthalpies (BDE) and enthalpies of formation of thienyl radicals were also computed.

Ribeiro da Silva, Manuel A. V.; Santos, Ana Filipa L. O. M.; Gomes, José R. B.; Roux, María Victoria; Temprado, Manuel; Jiménez, Pilar; Notario, Rafael

2009-09-01

138

Magnesium compounds  

USGS Publications Warehouse

Seawater and natural brines accounted for about 57 percent of magnesium compounds produced in the United States in 2011. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties LLC from well brines in Michigan. Caustic-calcined magnesia was recovered from seawater by Premier Magnesia LLC in Florida, from well brines in Michigan by Martin Marietta and from magnesite in Nevada by Premier Magnesia. Intrepid Potash Wendover LLC and Great Salt Lake Minerals Corp. recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from seawater by SPI Pharma Inc. in Delaware and Premier Magnesia in Florida, and by Martin Marietta from its brine operation in Michigan.

Kramer, D.A.

2012-01-01

139

Bismaleimide compounds  

DOEpatents

Bismaleimides of the formula shown in the diagram wherein R[sub 1] and R[sub 2] each independently is H, C[sub 1-4]-alkyl, C[sub 1-4]-alkoxy, Cl or Br, or R[sub 1] and R[sub 2] together form a fused 6-membered hydrocarbon aromatic ring, with the proviso that R[sub 1] and R[sub 2] are not t-butyl or t-butoxy; X is O, S or Se; n is 1--3; and the alkylene bridging group, optionally, is substituted by 1--3 methyl groups or by fluorine, form polybismaleimide resins which have valuable physical properties. Uniquely, these compounds permit extended cure times, i.e., they remain fluid for a time sufficient to permit the formation of a homogeneous melt prior to curing.

Adams, J.E.; Jamieson, D.R.

1986-01-14

140

Bismaleimide compounds  

DOEpatents

Bismaleimides of the formula ##STR1## wherein R.sub.1 and R.sub.2 each independently is H, C.sub.1-4 -alkyl, C.sub.1-4 -alkoxy, C1 or Br, or R.sub.1 and R.sub.2 together form a fused 6-membered hydrocarbon aromatic ring, with the proviso that R.sub.1 and R.sub.2 are not t-butyl or t-butoxy; X is O, S or Se; n is 1-3; and the alkylene bridging group, optionally, is substituted by 1-3 methyl groups or by fluorine, form polybismaleimide resins which have valuable physical properties. Uniquely, these compounds permit extended cure times, i.e., they remain fluid for a time sufficient to permit the formation of a homogeneous melt prior to curing.

Adams, Johnnie E. (Grandview, MO); Jamieson, Donald R. (Merriam, KS)

1986-01-14

141

Detection of nitrite and nitrosocompounds in chemical systems and biological liquids by the calorimetric method  

Microsoft Academic Search

The capacity of nitrite, S-nitrosothiols (RS-NO), dinitrosyl iron complexes (DNICs) with thiolcontaining ligands, and nitrosoamines\\u000a to inhibit catalase has been used for the selective determination of these compounds in purely chemical systems and biological\\u000a liquids: cow milk and colostrum. The limiting sensitivity of the method is 50 nM. A comparison of the results of the determinations\\u000a of RS-NO, DNIC, and

V. Yu. Titov; Yu. M. Petrenko; A. F. Vanin; I. I. Stepuro

2010-01-01

142

Calorimetric and computational study of thiacyclohexane 1-oxide and thiacyclohexane 1,1-dioxide (thiane sulfoxide and thiane sulfone). Enthalpies of formation and the energy of the S=O bond.  

PubMed

A rotating-bomb combustion calorimeter specifically designed for the study of sulfur-containing compounds [J. Chem. Thermodyn. 1999, 31, 635] has been used for the determination of the enthalpy of formation of thiane sulfone, 4, Delta(f)H(o) m(g) = -394.8 +/- 1.5 kJ x mol(-1). This value stands in stark contrast with the enthalpy of formation reported for thiane itself, Delta(f)H(o) m(g) = -63.5 +/- 1.0 kJ x mol(-1), and gives evidence of the increased electronegativity of the sulfur atom in the sulfonyl group, which leads to significantly stronger C-SO2 bonds. Given the known enthalpy of formation of atomic oxygen in the gas phase, Delta(f)H(o) m(O,g) = +249.18 kJ x mol(-1), and the reported bond dissociation energy for the S=O bond in alkyl sulfones, BDE(S=O) = +470.0 kJ x mol(-1), it was possible to estimate the enthalpy of formation of thiane sulfoxide, 5, a hygroscopic compound not easy to use in experimental calorimetric measurements, Delta(f)H(o) m(5) = -174.0 kJ x mol(-1). The experimental enthalpy of formation of both 4 and 5 were closely reproduced by theoretical calculations at the G2(MP2)+ level, Delta(f)H(o) m(4) = -395.0 kJ x mol(-1) and Delta(f)H(o) m(5) = -178.0 kJ x mol(-1). Finally, calculated G2(MP2)+ values for the bond dissociation energy of the S=O bond in cyclic sulfoxide 5 and sulfone 4 are +363.7 and +466.2 kJ x mol(-1), respectively. PMID:12608789

Roux, María Victoria; Temprado, Manuel; Jiménez, Pilar; Dávalos, Juan Zenón; Notario, Rafael; Guzmán-Mejía, Ramón; Juaristi, Eusebio

2003-03-01

143

Energy levels, radiative rates and electron impact excitation rates for transitions in Be-like Cl XIV, K XVI and Ge XXIX  

NASA Astrophysics Data System (ADS)

Results for energy levels, radiative rates and electron impact excitation (effective) collision strengths for transitions in Be-like Cl XIV, K XVI and Ge XXIX are reported. For the calculations of energy levels and radiative rates the general-purpose relativistic atomic structure package is adopted, while for determining the collision strengths and subsequently the excitation rates, the Dirac atomic R-matrix code is used. Oscillator strengths, radiative rates and line strengths are listed for all E1, E2, M1 and M2 transitions among the lowest 98 levels of the n?slant 4 configurations. Furthermore, lifetimes are provided for all levels and comparisons made with available theoretical and experimental results. Resonances in the collision strengths are resolved in a fine energy mesh and averaged over a Maxwellian velocity distribution to obtain the effective collision strengths. Results obtained are listed over a wide temperature range up to 107.8 K, depending on the ion.

Aggarwal, Kanti M.; Keenan, Francis P.

2014-12-01

144

Electromagnetic and calorimetric measurements for AC losses of a YBa2Cu3O7-delta coated conductor with Ni-alloy substrate  

Microsoft Academic Search

The AC losses of a rolling-assisted-biaxially-textured-substrate (RABiTS™) processed YBa2Cu3O7-delta (YBCO) coated conductor (Goyal et al 1996 Appl. Supercond. 4 403-27) with Ni-alloy substrate and Cu stabilizer were measured at 77 K by both calorimetric (CM) and electromagnetic (EM) methods. In the CM method, improvements in the measurement were observed when a Cernox temperature sensor was used to measure the temperature

D. N. Nguyen; P. V. P. S. S. Sastry; D. C. Knoll; J. Schwartz

2006-01-01

145

Electromagnetic and calorimetric measurements for AC losses of a YBa2Cu3O7?? coated conductor with Ni-alloy substrate  

Microsoft Academic Search

The AC losses of a rolling-assisted-biaxially-textured-substrate (RABiTS™) processed YBa2Cu3O7?? (YBCO) coated conductor (Goyal et al 1996 Appl. Supercond. 4 403–27) with Ni-alloy substrate and Cu stabilizer were measured at 77 K by both calorimetric (CM) and electromagnetic (EM) methods. In the CM method, improvements in the measurement were observed when a Cernox temperature sensor was used to measure the temperature

D N Nguyen; P V P S S Sastry; D C Knoll; J Schwartz

2006-01-01

146

Isothermal calorimetric investigation of a reversible reaction in rapidly solidified Fe/sub 40/Fi/sub 40/B/sub 20/  

SciTech Connect

A new method is described for isothermal calorimetric measurement of time-dependent reversible reactions in which the rate of heat flow is small compared to the noise and zero drift of the measurement. Results using this method are presented which measure enthalpy changes associated with reversible phase changes in a rapidly solidified Fe/sub 40/Ni/sub 40/B/sub 20/ alloy.

Cost, J.R.; Elliott, R.O.; Stanley, J.T.

1983-01-01

147

A Calorimetric Study of Almandine: Are the Thermodynamic Properties of the End-Member Aluminosilicate Garnets Finally Known Quantitatively?  

NASA Astrophysics Data System (ADS)

The aluminosilicate garnets (E3Al2Si3O12 with E = Fe2+, Mn2+, Ca, Mg) form an important rock-forming mineral group. Much study has been directed toward determining their thermodynamic properties. The iron end-member almandine (Fe3Al2Si3O12) is a key phase in many petrologic investigations. As part of an ongoing calorimetric and thermodynamic study of the aluminosilicate garnets, the heat capacity of three synthetic well-characterized polycrystalline almandine garnets and one natural almandine-rich single crystal was measured. The various garnets were characterized by optical microscopy, electron-microprobe analysis, X-ray powder diffraction and 57Fe Mössbauer spectroscopy. Heat capacity measurements were performed in the temperature range 3 to 300 K using relaxation calorimetry and between 282 and 764 K using DSC methods. From the former, So values between 336.7 ± 0.8 and 337.8 ± 0.8 J/molK are calculated for the different samples. The smaller value is considered the best So for end-member stoichiometric almandine, because it derives from the "best" Fe3+-free synthetic sample. The Cp behavior for almandine at T > 298 K is given by the polynomial (in J/molK): Cp = 649.06(±4) - 3837.57(±122)T-0.5 - 1.44682(±0.06)107T-2 + 1.94834(±0.09)109T-3, which is calculated using DSC data together with one published heat-content datum determined by transposed-drop calorimetry along with a new determination that gives H1181K - H302K = 415.0 ± 3.2 kJ/mole. Almandine shows a ?-type heat-capacity anomaly at low temperatures resulting from a paramagnetic-antiferromagnetic phase transition at about 9 K. The lattice heat capacity was calculated using the single-parameter phonon dispersion model of Komada and Westrum (1997), which allows the non-lattice heat capacity (Cex) behavior to be modelled. An analysis shows the presence of an electronic heat-capacity contribution (Cel - Schottky anomaly) around 17 K that is superimposed on a larger magnetic heat-capacity effect (Cmag). The calculated lattice entropy at 298.15 K is Svib = 303.3 J/molK and it contributes about 90% to the total standard entropy at 298 K. The non-lattice entropy is Sex = 33.4 J/molK and consists of Smag = 32.1 J/molK and Sel = 1.3 J/molK contributions. Using the So = 336.7 J/molK value and the Cp polynomial for almandine, we derived its enthalpy of formation, ?Hof, from an analysis of experimental phase equilibrium results on the reactions almandine + 3rutile = 3ilmenite + sillimanite + 2quartz and 2ilmenite = 2iron + 2rutile + O2. ?Hof = -5269.63 kJ/mol was obtained. So for grossular, pyrope, spessartine, and almandine, as well as their Cp behavior to high temperatures, have all been measured calorimetrically. Uncertainties in older calorimetric studies appear to have been resolved. The standard thermodynamic properties Vo and So are now well determined for all four garnets. In addition, ?Hof for all, except possibly spessartine, also appear to be well known.

Dachs, E.; Geiger, C. A.; Benisek, A.

2012-12-01

148

Slovenica XVI—XIX ??. ? ?????? ??????? ?????????? ?????????? (??????????) ???????????? (? ????????????????? ?????????????)  

E-print Network

University possesses the necessary materials for research on the history of the Slovene language. SLOVENE: Znanstvena knjižnica Univerze v Tartuju, ki danes obsega ve? kot pet milijonov enot, je bila ustanovljena leta 1802. V njej je med drugim tudi ve? knjig...

Dulichenko, Aleksandr D.

2001-01-01

149

Thermochemistry of 2- and 3-thiopheneacetic acids: calorimetric and computational study.  

PubMed

The enthalpies of formation in the condensed and gas states, Delta f H m degrees (cd) and Delta f H m degrees (g), of 2- and 3-thiopheneacetic acids were derived from their respective enthalpies of combustion in oxygen, measured by a rotating bomb calorimeter, and the variation of vapor pressure with temperature determined by the Knudsen effusion technique. Theoretical calculations at the G3 level were performed, and a study on molecular and electronic structure of the compounds has been carried out. Calculated Delta f H m degrees (g) values using atomization and isodesmic reactions are compared with the experimental data. Experimental and theoretical results show that the 3-thiopheneacetic acid is thermodynamically more stable than the 2-isomer. PMID:18816026

Temprado, Manuel; Roux, María Victoria; Jiménez, Pilar; Foces-Foces, Concepción; Notario, Rafael

2008-10-16

150

Backbone nuclear relaxation characteristics and calorimetric investigation of the human Grb7-SH2/erbB2 peptide complex  

PubMed Central

Grb7 is a member of the Grb7 family of proteins, which also includes Grb10 and Grb14. All three proteins have been found to be overexpressed in certain cancers and cancer cell lines. In particular, Grb7 (along with the receptor tyrosine kinase erbB2) is overexpressed in 20%–30% of breast cancers. Grb7 binds to erbB2 and may be involved in cell signaling pathways that promote the formation of metastases and inflammatory responses. In a prior study, we reported the solution structure of the Grb7-SH2/erbB2 peptide complex. In this study, T1, T2, and steady-state NOE measurements were performed on the Grb7-SH2 domain, and the backbone relaxation behavior of the domain is discussed with respect to the potential function of an insert region present in all three members of this protein family. Isothermal titration calorimetry (ITC) studies were completed measuring the thermodynamic parameters of the binding of a 10-residue phosphorylated peptide representative of erbB2 to the SH2 domain. These measurements are compared to calorimetric studies performed on other SH2 domain/phosphorylated peptide complexes available in the literature. PMID:15930003

Ivancic, Monika; Spuches, Anne M.; Guth, Ethan C.; Daugherty, Margaret A.; Wilcox, Dean E.; Lyons, Barbara A.

2005-01-01

151

Calorimetric Low-Temperature Detectors for X-Ray Spectroscopy on Trapped Highly-Charged Heavy Ions  

NASA Technical Reports Server (NTRS)

The application of Calorimetric Low-Temperature Detectors (CLTDs) has been proposed at the Heavy-Ion TRAP facility HITRAP which is currently being installed at the Helmholtz Research Center for Heavy Ion Research GSI. This cold ion trap setup will allow the investigation of X-rays from ions practically at rest, for which the excellent energy resolution of CLTDs can be used to its full advantage. However, the relatively low intensities at HITRAP demand larger solid angles and an optimized cryogenic setup. The influence of external magnetic fields has to be taken into account. CLTDs will also be a substantial part of the instrumental equipment at the future Facility for Antiproton and Heavy Ion Research (FAIR), for which a wide variety of high-precision X-ray spectroscopy experiments has been proposed. This contribution will give an overview on the chances and challenges for the application of CLTDs at HITRAP as well as perspectives for future experiments at the FAIR facility.

Kilbourne, Caroline; Kraft-Bermuth, S.; Andrianov, V.; Bleile, A.; Echler, A.; Egelhof, P.; Ilieva, S.; Kilbourne, C.; McCammon, D.

2012-01-01

152

Simultaneous measurements of high-temperature total hemispherical emissivity and thermal conductivity using a steady-state calorimetric technique  

NASA Astrophysics Data System (ADS)

A method was developed to simultaneously measure the total hemispherical emissivity and the thermal conductivity of samples at high temperatures. The inverse problem to determine the emissivity and thermal conductivity from steady-state high-temperature calorimetric experiments was established based on models for these two quantities. The accuracy of the inverse solution was numerically analyzed for various noise levels for samples with various thermophysical properties. The simulation results illustrate that the calculation accuracies for the emissivity and thermal conductivity strongly depend on the proportions of the radiation and conduction heat fluxes in the strip sample arising from the temperature distributions in the sample. Steady-state high-temperature experiments with nickel samples were used to experimentally verify the method. The inverse solution results for the emissivity and thermal conductivity calculated from the measured data agree well with reported data in the literature. This research provides a useful reference for measuring the total hemispherical emissivity and thermal conductivity of conductive samples at high temperatures.

Fu, Tairan; Tan, Peng; Duan, Minghao

2015-01-01

153

Kinetics of Solid-State Reactions in Al-Li-Cu-Mg-Zr Alloys from Calorimetric Studies  

NASA Astrophysics Data System (ADS)

Differential scanning calorimetric (DSC) studies at different heating rates have been carried out to examine the solid-state reactions in 1441 and 8090 Al-Li-Cu-Mg-Zr alloys of water-quenched (WQ) and retrogressed tempers. The DSC peaks indicating the reactions sequence such as formation of GPB zones, precipitations of ?' phase, dissolution of GPB zones and ?' precipitates, and precipitations of S', T 1, T 2, and ? phases have been identified. From the heat flow associated with the peaks of the thermograms, the fraction transformation ( Y), the rate of transformation ( dY/ dt), the activation energy ( Q*), the frequency factor ( k 0), and the transformation function f( Y) for all the reactions of the 1441 and 8090 alloys have been determined. The appearance of separate peaks of GPB zone formation and ?' precipitation in the 1441 alloy of retrogressed tempers has enabled determination of the kinetic parameters, which is otherwise not possible from the thermograms of the WQ state due to peak overlapping, by varying heating rate method. The kinetic parameters determined from the DSC data of all the reactions of the alloys are in good agreement with the previously published data.

Ghosh, K. S.; Das, K.; Chatterjee, U. K.

2007-09-01

154

Calorimetric and thermomechanical properties of titanium-based orthodontic wires: DSC-DMA relationship to predict the elastic modulus.  

PubMed

Orthodontic treatment is strongly dependent on the loads developed by metal wires, and the choice of an orthodontic archwire should be based on its mechanical performance. The desire of both orthodontists and engineers would be to predict the mechanical behavior of archwires. To this aim, Gum Metal (Toyota Central R&L Labs., Inc.), TMA (ORMCO), 35°C Copper NiTi (SDS ORMCO), Thermalloy Plus (Rocky Mountain), Nitinol SE (3M Unitek), and NiTi (SDS ORMCO) were tested according to dynamic mechanical analysis and differential scanning calorimetry. A model was also developed to predict the elastic modulus of superelastic wires. Results from experimental tests have highlighted that superelastic wires are very sensitive to temperature variations occurring in the oral environment, while the proposed model seems to be reliable to predict the Young's modulus allowing to correlate calorimetric and mechanical data. Furthermore, Gum Metal wire behaves as an elastic material with a very low Young's modulus, and it can be particularly useful for the initial stage of orthodontic treatments. PMID:21343211

Laino, Giuliana; De Santis, Roberto; Gloria, Antonio; Russo, Teresa; Quintanilla, David Suárez; Laino, Alberto; Martina, Roberto; Nicolais, Luigi; Ambrosio, Luigi

2012-03-01

155

Simultaneous measurement of specific heat and total hemispherical emissivity of metals by the transient calorimetric technique  

SciTech Connect

The specific heat c and total hemispherical emissivity {var_epsilon}{sub h} of iron and constantan have been measured using a simultaneous-measurement method proposed in a previous paper to verify the accuracy of the measurements. Cylindrical specimens, whose geometrical shape is presumed to be more appropriate than those in the previous study are used as the compound specimens necessary for the method. To obtain more accurate results, an expression for the temperature versus time curve has been developed; this expression is highly accurate over the entire temperature range. For iron, the measured c- and {var_epsilon}{sub h}-values are compared with c-values recommended in the CINDAS Data Series and with {var_epsilon}{sub h}-values previously measured by H. Masuda and M. Higano, respectively. For constantan, empirical relations between c and T (temperature) and {var_epsilon}{sub h} and T are obtained. Errors in the present results are analyzed and the total errors in the results are estimated.

Sasaki, Seizi; Masuda, Hidetoshi; Higano, Mitsuo; Sasaki, Hiroshi

1995-02-01

156

Calorimetric and computational study of 1,3- and 1,4-oxathiane sulfones.  

PubMed

The enthalpies of formation in the condensed and gas states, DeltafH degrees m(cd) and DeltafH degrees m(g), of 1,3- and 1,4-oxathiane sulfones were derived from their respective enthalpies of combustion in oxygen, measured by a rotating bomb calorimeter and the variation of vapor pressures with temperatures determined by the Knudsen effusion technique. Standard ab initio molecular orbital calculations at the G2(MP2) and G3 levels were performed, and a theoretical study on molecular and electronic structure of the compounds has been carried out. Calculated DeltafH degrees m(g) values at the G3 level using atomization reactions agree well with the experimental ones. These experimental and theoretical studies support that the destabilization found in 1,3-oxathiane sulfone, 11.2 kJ mol-1 respecting to 1,4-oxathiane sulfone, is due to the electrostatic repulsion between the negative charges of the axial oxygen of the sulfone and the oxygen of the ring and apparently masks any stabilization originating from the hyperconjugative nO --> sigma*C-SO2 stereoelectronic interaction. PMID:17288369

Roux, María Victoria; Temprado, Manuel; Jiménez, Pilar; Notario, Rafael; Guzman-Mejía, Ramón; Juaristi, Eusebio

2007-02-16

157

Electrical properties and conduction mechanism of [C2H5NH3]2CuCl4 compound  

NASA Astrophysics Data System (ADS)

The [(C2H5)NH3]2CuCl4 compound was prepared and characterized by several technique: the X-ray powder diffraction confirms the purity of the synthetized compound, the differential scanning calorimetric show several phase transitions at 236 K, 330 K, 357 K and 371 K, the dialectical properties confirms the ferroelectric-paraelectric phase transition at 238 K, which is reported by V. Kapustianyk et al. (2007) [1]. The two semi-circles observed in the complex impedance identify the presence of the grain interior and grain boundary contributions to the electrical response in this material. The equivalent circuit is modeled by a combination series of two parallel RP-CPE circuits. The temperature dependence of the alternative current conductivity (?g) and direct current conductivity (?dc) confirm the observed transitions in the calorimetric study. The (AC) electrical conduction in [(C2H5)NH3]2CuCl4 was studied by two processes that can be attributed to a hopping transport mechanism: the non-overlapping small polaron tunneling (NSPT) model in phase III and the correlated barrier hopping (CBH) model in phases I, II, IV, V and VI.

Mohamed, C. Ben; Karoui, K.; Jomni, F.; Guidara, K.; Rhaiem, A. Ben

2015-02-01

158

Comparative spectroscopic, calorimetric, and computational studies of nucleic acid complexes with 2',5"-versus 3',5"-phosphodiester linkages.  

PubMed

We have used a combination of spectroscopic, calorimetric, and computational techniques to characterize the properties of nucleic acid complexes with 2',5''- and 3',5''-phosphodiester linkages. Specifically, we have compared the properties of complexes formed by the association of 3',5'' single-stranded 16-mers of adenylic acid (A16) and thymidylic acid (T16) with the complexes formed by the corresponding single-stranded 16-mers with 2',5''-phosphodiester linkages (A*16 and T*16). Our results reveal the following differential features: (i) the 3',5'' strands form either a duplex or a triplex, depending on the sodium ion concentration, whereas the 2',5'' strands form either a triplex or no complex at all; (ii) the 2',5'' and 3',5'' triplexes exhibit significantly different CD spectra, suggesting that the two triplex states are conformationally nonequivalent; (iii) the 2',5'' triplex has a lower charge density than the 3',5'' triplex; (iv) the thermal stability of the 3',5'' triplex, as expected, is concentration dependent, whereas the thermal stability of the 2',5'' triplex is concentration independent; (v) relative to their component single strands, the 2',5'' triplex is thermodynamically much less stable than the 3',5'' triplex, despite being thermally more stable; (vi) the reduced thermodynamic stability of the 2',5'' triplex relative to the 3',5'' triplex is overwhelmingly enthalpic in origin. In the aggregate, our results reveal and characterize significant differences in the properties of complexes formed by the association of strands with identical base sequences but different phosphodiester linkages. We describe a structural model that is consistent with many of the differential properties observed. We also speculate on how these differential properties may have provided an evolutionary advantage for 3',5'' linkages and how the properties of 2',5'' complexes might be exploited in antisense strategies. PMID:8248146

Jin, R; Chapman, W H; Srinivasan, A R; Olson, W K; Breslow, R; Breslauer, K J

1993-11-15

159

Spectroscopic and calorimetric studies on the binding of an indoloquinoline drug to parallel and antiparallel DNA triplexes.  

PubMed

11-Phenyl-substituted indoloquinolines have been found to exhibit significant antiproliferative potency in cancer cells but to show only moderate affinity toward genomic double-helical DNA. In this study, parallel as well as antiparallel triple-helical DNA targets are employed to evaluate the triplex binding of these ligands. UV melting experiments with parallel triplexes indicate considerable interactions with the drug and a strong preference for TAT-rich triplexes in line with an increasing number of potential intercalation sites of similar binding strength between two TAT base triads. Via substitution of a singly charged aminoethylamine side chain by a longer and doubly charged bis(aminopropyl)amine substituent at the ligand, binding affinities increase and also start to exhibit long-range effects as indicated by a strong correlation between the binding affinity and the overall length of the TAT tract within the triplex stem. Compared to parallel triplexes, an antiparallel triplex with a GT-containing third strand constitutes a preferred target for the indoloquinoline drug. On the basis of pH-dependent titration experiments and corroborated by a Job analysis of continuous variation, binding of the drug to the GT triplex not only is strongly enhanced when the solution pH is lowered from 7 to 5 but also reveals a pH-dependent stoichiometry upon formation of the complex. Calorimetric data demonstrate that stronger binding of a protonated drug at acidic pH is associated with a more exothermic binding process. However, at pH 7 and 5, binding is enthalpically driven with additional favorable entropic contributions. PMID:23234257

Riechert-Krause, Fanny; Autenrieth, Karolin; Eick, Andrea; Weisz, Klaus

2013-01-01

160

Localized Recrystallization in Cast Al-Si-Mg Alloy during Solution Heat Treatment: Dilatometric and Calorimetric Studies  

NASA Astrophysics Data System (ADS)

During heat treatment, the work piece experiences a range of heating rates depending upon the sizes and types of furnace. When the Al-Si-Mg cast alloy is heated to the solutionizing temperature, recrystallization takes place during the ramp-up stage. The effect of heating rate on recrystallization in the A356 (Al-Si-Mg) alloy was studied using dilatometric and calorimetric methods. Recrystallization in as-cast Al-Si alloys is a localized event and is confined to the elasto-plastic zone surrounding the eutectic Si phase; there is no evidence of recrystallization in the center of the primary Al dendritic region. The size of the elasto-plastic zone is of the same order of magnitude as the Si particles, and recrystallized grains are observed in the elasto-plastic region near the Si particles. The coefficient of thermal expansion of Al is an order of magnitude greater than Si, and thermal stresses are generated due to the thermal mismatch between the Al phase and Si particles providing the driving force for recrystallization. In contrast, recrystallization in Al wrought alloy (7075) occurs uniformly throughout the matrix, stored energy due to cold work being the driving force for recrystallization in wrought alloys. The activation energy for recrystallization in as-cast A356 alloy is 127 KJ/mole. At a slow heating rate of 4.3 K/min, creep occurs during the heating stage of solution heat treatment. However, creep does not occur in samples heated at higher heating rates, namely, 520, 130, and 17.3 K/min.

Chaudhury, S. K.; Warke, V.; Shankar, S.; Apelian, D.

2011-10-01

161

Spectroscopic and calorimetric studies on the binding of alkaloids berberine, palmatine and coralyne to double stranded RNA polynucleotides.  

PubMed

The interaction of two natural protoberberine plant alkaloids berberine and palmatine and a synthetic derivative coralyne to three double stranded ribonucleic acids, poly(A). poly(U), poly(I).poly(C) and poly(C).poly(G) was studied using various biophysical techniques. Absorbance and fluorescence studies showed that the alkaloids bound cooperatively to these RNAs with the binding affinities of the order 10(4) M(-1). Circular dichroic results suggested that the conformation of poly(A). poly(U) was perturbed by all the three alkaloids, that of poly(I).poly(C) by coralyne only and that of poly(C).poly(G) by none. Fluorescence quenching studies gave evidence for partial intercalation of berberine and palmatine and complete intercalation of coralyne to these RNA duplexes. Isothermal titration calorimetric studies revealed that the binding was characterized by negative enthalpy and positive entropy changes and the affinity constants derived were in agreement with the overall binding affinity from spectral data. The binding of all the three alkaloids considerably stabilized the melting of poly(A). poly(U) and poly(I).poly(C) and the binding data evaluated from the melting data were in agreement with that obtained from other techniques. The overall binding affinity of the alkaloids to these double stranded RNAs varied in the order, berberine = palmatine < coralyne. The temperature dependence of the enthalpy changes afforded large negative values of heat capacity changes for the binding of palmatine and coralyne to poly(A).poly(U) and of coralyne to poly(I).poly(C), suggesting substantial hydrophobic contribution in the binding process. Further, enthalpy-entropy compensation was also seen in almost all the systems that showed binding. These results further advance our understanding on the binding of small molecules that are specific binders to double stranded RNA sequences. PMID:19132839

Islam, Md Maidul; Chowdhury, Sebanti Roy; Kumar, Gopinatha Suresh

2009-01-29

162

Dynamics of the n-decylammonium chains in the perovskite-type layer structure compound (C10H21NH3)2CdCl4  

Microsoft Academic Search

The two structural phase transitions in the perovskite layer structure compound (C10H21NH3)2CdCl4 at Tc1=35 °C and Tc2=39 °C have been studied by x-ray diffractional, calorimetric and dielectric measurements, proton NMR spin-lattice relaxation and second moment investigations, 35Cl and 14N quadrupole resonance spectroscopy as well as group theoretical considerations. The results show that the transition (Tc1) from the low temperature phase

R. Kind; H. Arend; R. Blinc; J. Seliger; J. Slak; A. Levstik; G. Lahajnar; F. Milia; G. Chapuis

1979-01-01

163

THE IRON PROJECT AND THE RMAX PROJECT: Radiative and CollisionalProcesses of Iron Ions - Fe I, Fe II, Fe XVI, Fe XVII  

NASA Astrophysics Data System (ADS)

Results from work in progress under the Iron Project and Rmax Project on electron impact excitation and radiative processes of photo-excitations, photoionization and electron-ion recombination will be reported. Whereas the Iron Project is involved in scattering and radiative atomic processes of iron and iron-peak elements, and the Rmax Project aims particularly at the X-ray spectroscopy of astrophysical objects. We will present (i) collision strengths of Fe II at low energies using an accurate wavefunction needed for spectral analysis of infrared region, (ii) oscillator strengths and radiative decay rates for allowed and forbidden transitions in Fe I and Fe II, (iii) photoionization and electron-ion recombination of ground state of Fe XVI for over a large energy/temperature range up to and including K-shell ionization and core excitations as observed in X-ray spectra, and (iv) photoionization cross sections of large number fine structure levels (n<=10 and 0 <= 10) needed for astrophysical and modeling work. Relativistic approach in the Breit-Pauli approximation is being employed to study these atomic processes.

Montenegro, Maximiliano; Nahar, Sultana; Pradhan, Anil; Sur, Chiranjib

2008-05-01

164

Energy levels, radiative rates and electron impact excitation rates for transitions in He-like Cl XVI, K XVIII, Ca XIX and Sc XX  

NASA Astrophysics Data System (ADS)

We report calculations of energy levels, radiative rates and electron impact excitation cross sections and rates for transitions in He-like Cl XVI, K XVIII, Ca XIX and Sc XX. The GRASP (general-purpose relativistic atomic structure package) is adopted for calculating energy levels and radiative rates. To determine the collision strengths and subsequently the excitation rates, the Dirac atomic R-matrix code (DARC) is used. Oscillator strengths, radiative rates and line strengths are reported for all E1, E2, M1 and M2 transitions among the lowest 49 levels of each ion. Collision strengths are averaged over a Maxwellian velocity distribution and the effective collision strengths obtained listed over a wide temperature range up to 107.4 K. Comparisons are made with similar data obtained from the flexible atomic code (FAC) to highlight the importance of resonances, included in calculations with DARC, in the determination of effective collision strengths. Discrepancies between the collision strengths from DARC and FAC, particularly for forbidden transitions, are also discussed. Additionally, theoretical lifetimes are listed for all the 49 levels of the above four ions.

Aggarwal, Kanti M.; Keenan, Francis P.

2012-02-01

165

Coproportionation thermodynamics of homoligand solvates of samarium(III) and Yttrium(III) nitrates with neutral organophosphorus compounds  

SciTech Connect

The heats of coproportionation of homoligand solvates of samarium(III) and yttrium(III) nitrates with neutral organophosphorus compounds (tri-n-butyl phosphate, diisooctyl methylphosphonate, and diisoamyl methylphosphonate) in hexane at 298.15 K have been determined calorimetrically. The enthalpies of coproportionation are virtually independent of the nature and concentration of solvates of rare earth metal(III) nitrates in hexane and of the nature of neutral organophosphorus compound and amount to -1.1{plus_minus}0.2 kJ mol{sup -1}. The Gibbs free energy of coproportionation is -5.43 kJ mol{sup -1}, and the entropy is 14.5{plus_minus}0.7 J mol{sup -1} K{sup -1}.

Pyartman, A.K. [St. Petersburg Technological Institute (Russian Federation)

1995-07-01

166

Dinitroso and polynitroso compounds  

PubMed Central

The growing interest in the chemistry of C-nitroso compounds (RN=O; R = alkyl or aryl group) is due in part to the recognition of their participation in various metabolic processes of nitrogen-containing compounds. C-Nitroso compounds have a rich organic chemistry in their own right, displaying interesting intra- and intermolecular dimerization processes and addition reactions with unsaturated compounds. In addition, they have a fascinating coordination chemistry. While most of the attention has been directed towards C-nitroso compounds containing a single –NO moiety, there is an emerging area of research dealing with dinitroso and polynitroso compounds. In this critical review, we present and discuss the synthetic routes and properties of these relatively unexplored dinitroso and polynitroso compounds, and suggest areas of further development involving these compounds. (126 references.) PMID:16100619

Gowenlock, Brian G.; Richter-Addo, George B.

2005-01-01

167

Probe Beam Detection of Laser-Induced Breakdown for Measuring Solubility of Actinide Compounds  

NASA Astrophysics Data System (ADS)

A nondestructive laser-induced breakdown detection technique is developed, which entails measuring the deflection of a probe laser beam due to a shock wave generated by a laser-induced breakdown of colloidal nanoparticles in liquids. Comparing this optical method with a previously developed acoustic detection method using a piezoelectric transducer, it enables remote measurement and therefore facilitates the in situ measurement of samples in a radiation-shielded glove box. The probe beam detection of a shock wave shows a sufficiently high sensitivity for monitoring the initial colloid formation when the uranium ion concentration exceeds the solubility limit of uranium hydrolysis compounds at a certain pH. The mean solubility product log Ksp° = -23.23 ±0.04 at an ionic strength of zero determined in this work agrees well with the previously reported result, log Ksp° = -23.19 ±0.43, measured by a calorimetric experiment on UO3·2H2O(cr).

Cho, Hye-Ryun; Jung, Euo Chang; Jee, Kwang Yong

2008-05-01

168

Calorimetric and acoustic emission study of martensitic transformation in single-crystalline Ni2MnGa alloys  

NASA Astrophysics Data System (ADS)

The jerky character of austenite-martensite phase transformation in Ni2MnGa single crystals (with 10M martensite structure) has been investigated by thermal cycling using a differential scanning calorimeter (DSC) and by detection of acoustic emissions (AEs) at low cooling and heating rates (0.1 K/min and below). It is illustrated that, besides the low cooling and heating rate, mass and surface roughness are also important parameters in optimizing the best signal/noise ratio in order to obtain individual peaks suitable for statistical analysis. Three types of samples, differing in the twin structure and twin boundary behavior, were investigated with and without surface roughening made by electro-erosion. The statistical analysis, carried out for both (thermal and acoustic) types of signals, provided power-law behavior. In calorimetric measurements the energy exponents, obtained in cooling, were the same within the experimental errors (? =1.7 ±0.2 ) for the three samples investigated. In acoustic emission experiments the energy and amplitude, ? , exponents were determined both for cooling and heating. The exponents for cooling and heating runs are slightly different. They are larger for heating for both ? and ? , in accordance with the asymmetric acoustic activity: we observed higher acoustic activity (higher number of hits) during cooling. The effect of the surface roughness is negligible in the exponents (but higher acoustic activity corresponds to higher roughness) and the following values were obtained: ? =1.5 ±0.1 and ? =2.1 ±0.1 for cooling as well as ? =1.8 ±0.1 and ? =2.6 ±0.1 for heating. Our results are in accordance with the results of Gallardo et al. [Phys. Rev. B 81, 174102 (2010), 10.1103/PhysRevB.81.174102] obtained in Cu based alloys: the exponents of the energy distributions, for both DSC and AE signals, were the same within the experimental errors. Furthermore, our exponents obtained from the AE measurements are close to the values obtained by Ludwig et al. (? =2.6 ±0.1 and ? =1.75 ±0.1 ) [App. Phys. Lett. 94 121901 (2009), 10.1063/1.3103289] and Niemann et al. (? =1.9 ±0.1 ) [Phys. Rev. B 86, 214101 (2012), 10.1103/PhysRevB.86.214101] in Ni2MnGa alloys with similar 10M martensite structure.

Tóth, László Z.; Szabó, Sándor; Daróczi, Lajos; Beke, Dezs? L.

2014-12-01

169

Magnetic, Calorimetric, and Transport Studies of Coupling and Interstrand Contact Resistance in Nb3Sn Rutherford Cables with Bimetallic Cores of Stainless Steel Bonded to Copper  

NASA Astrophysics Data System (ADS)

Magnetic and calorimetric techniques were used to measure coupling loss in small-scale (typically 20-strand) Rutherford cables inclosing bimetallic stainless steel-and-copper cores. The effects of two types of core were studied: (i) a double core consisting of two strips of bimetallic Cu/SS with the stainless steel (SS) surfaces facing each other; (ii) a single composite core with Cu sandwiched between two strips of SS — a kind of "thick-core reference". A "no-core reference" cable was also included in the measurement set. In the double-core cable the facing SS strips (with their included surface oxide layer) were intended to inhibit crossover interstrand contact at the same time that side-by-side contact would be enhanced by the diffusion bonding of the outer strip surfaces to the strand during the cable's prolonged heat treatment under a uniaxial pressure of 20 MPa. Coupling loss in this double-core cable was small but measurable and very much less than that of the uncored cable. Coupling loss in the composite core cable was immeasurably small. The losses were expressed quantitatively in terms of interstrand contact resistances (ICR) deduced from the magnetic- and calorimetric coupling-loss results. ICR data were also obtained by direct measurement using the four-terminal transport method.

Sumption, M. D.; Scanlan, R. M.; Illyin, Yu. A.; Nijhuis, A.; Collings, E. W.

2004-06-01

170

Thermodynamic properties of illite, smectite and beidellite by calorimetric methods: Enthalpies of formation, heat capacities, entropies and Gibbs free energies of formation  

NASA Astrophysics Data System (ADS)

The thermodynamic properties of three aluminous 2:1 clay minerals were acquired at 1.013 bars and at temperatures between 5 and 500 K using various calorimetric methods. Calorimetric measurements were performed on hydrated and dehydrated <2 ?m clay fractions of smectite MX-80 (Wyoming), illite IMt-2 (Silver Hill) and beidellite SBId-1 (Black Jack Mine). After purification, the mineralogical analyses gave the following structural formulae: NaKCa(SiAl)(AlMgFe0.1733+Fe0.0352+)O(OH)2,KNa(SiAl)(AlMgFe0.2923+Fe0.0842+)O(OH)2 and CaK(SiAl)(AlMgFe0.1123+)O(OH)2 for smectite MX-80, illite IMt-2 and beidellite SBId-1, respectively. Heat capacities were measured by low temperature adiabatic calorimetry and differential scanning calorimetry, from 5 to 500 K. Standard enthalpies of formation were obtained from solution-reaction calorimetry at 298.15 K. The standard Gibbs free energies of formation of the clay minerals were also calculated, together with the equilibrium constants at 25 °C, for anhydrous and hydrated minerals. A comparison between these experimental data and estimated values obtained from prediction models available in the literature, enabled the calculation method that appears to be the most relevant to be selected, at least for aluminous 2:1 clay minerals.

Gailhanou, H.; Blanc, P.; Rogez, J.; Mikaelian, G.; Kawaji, H.; Olives, J.; Amouric, M.; Denoyel, R.; Bourrelly, S.; Montouillout, V.; Vieillard, P.; Fialips, C. I.; Michau, N.; Gaucher, E. C.

2012-07-01

171

[Ubiquitous perfluorinated compounds].  

PubMed

Perfluorinated compounds are derivatives of hydrocarbons, in which all or most of hydrogen atoms are substitiuted by fluorine atoms. These compounds are commonly used in many branches of industry. Perfluorinated compounds are in the limelight because of numerous reports concerning their toxicity and negative effects on human health as well as contradictory information about their cancerogenic effect. The above compounds are used in production of many commonly used products including such brand names as Gore-Tex, Teflon, Stainmaster. The most common ways of penetrating these compounds into a human organism are: via food, inhalation and skin contact. Perfluorooctanesulfonate (PFOS) has been added to the list of persistent organic pollutants (POPs). PMID:21980858

Kucharska, Agnieszka; Góralczyk, Katarzyna; Czaja, Katarzyna; Struci?ski, Pawe?; Hernik, Agnieszka; Korcz, Wojciech; Snopczy?iski, Tomasz; Ludwicki, Jan K

2011-01-01

172

Micromechanical calorimetric sensor  

DOEpatents

A calorimeter sensor apparatus is developed utilizing microcantilevered spring elements for detecting thermal changes within a sample containing biomolecules which undergo chemical and biochemical reactions. The spring element includes a bimaterial layer of chemicals on a coated region on at least one surface of the microcantilever. The chemicals generate a differential thermal stress across the surface upon reaction of the chemicals with an analyte or biomolecules within the sample due to the heat of chemical reactions in the sample placed on the coated region. The thermal stress across the spring element surface creates mechanical bending of the microcantilever. The spring element has a low thermal mass to allow detection and measuring of heat transfers associated with chemical and biochemical reactions within a sample placed on or near the coated region. A second surface may have a different material, or the second surface and body of microcantilever may be of an inert composition. The differential thermal stress between the surfaces of the microcantilever create bending of the cantilever. Deflections of the cantilever are detected by a variety of detection techniques. The microcantilever may be approximately 1 to 200 .mu.m long, approximately 1 to 50 .mu.m wide, and approximately 0.3 to 3.0 .mu.m thick. A sensitivity for detection of deflections is in the range of 0.01 nanometers. The microcantilever is extremely sensitive to thermal changes in samples as small as 30 microliters.

Thundat, Thomas G. (Knoxville, TN); Doktycz, Mitchel J. (Knoxville, TN)

2000-01-01

173

Calorimetric system and method  

DOEpatents

Apparatus for measuring heat capacity of a sample where a series of measurements are taken in succession comprises a sample holder in which a sample to be measured is disposed, a temperature sensor and sample heater for providing a heat pulse thermally connected to the sample, and an adiabatic heat shield in which the sample holder is positioned and including an electrical heater. An electrical power supply device provides an electrical power output to the sample heater to generate a heat pulse. The electrical power from a power source to the heat shield heater is adjusted by a control device, if necessary, from one measurement to the next in response to a sample temperature-versus-time change determined before and after a previous heat pulse to provide a subsequent sample temperature-versus-time change that is substantially linear before and after the subsequent heat pulse. A temperature sensor is used and operable over a range of temperatures ranging from approximately 3K to 350K depending upon the refrigerant used. The sample optionally can be subjected to dc magnetic fields such as from 0 to 12 Tesla (0 to 120 kOe).

Gschneidner, Jr., Karl A. (Ames, IA); Pecharsky, Vitalij K. (Ames, IA); Moorman, Jack O. (Boone, IA)

1998-09-15

174

Calorimetric system and method  

DOEpatents

Apparatus is described for measuring heat capacity of a sample where a series of measurements are taken in succession comprises a sample holder in which a sample to be measured is disposed, a temperature sensor and sample heater for providing a heat pulse thermally connected to the sample, and an adiabatic heat shield in which the sample holder is positioned and including an electrical heater. An electrical power supply device provides an electrical power output to the sample heater to generate a heat pulse. The electrical power from a power source to the heat shield heater is adjusted by a control device, if necessary, from one measurement to the next in response to a sample temperature-versus-time change determined before and after a previous heat pulse to provide a subsequent sample temperature-versus-time change that is substantially linear before and after the subsequent heat pulse. A temperature sensor is used and operable over a range of temperatures ranging from approximately 3K to 350K depending upon the refrigerant used. The sample optionally can be subjected to dc magnetic fields such as from 0 to 12 Tesla (0 to 120 kOe). 18 figs.

Gschneidner, K.A. Jr.; Pecharsky, V.K.; Moorman, J.O.

1998-09-15

175

The Bayer Facts of Science Education XVI: US STEM Workforce Shortage— Myth or Reality? Fortune 1000 Talent Recruiters on the Debate  

NASA Astrophysics Data System (ADS)

A major debate is currently underway in the USA about whether there is, in fact, a science, technology, engineering and mathematics (STEM) workforce shortage in the country or not. This is the subject of the Bayer Facts of Science Education XVI: US STEM Workforce Shortage—Myth or Reality? Fortune 1000 Talent Recruiters on the Debate. An ongoing public opinion research project commissioned by Bayer Corporation, the Bayer Facts surveys examine US STEM education, diversity and workforce issues. The 16th in the series, the newest survey asks talent recruiters at some of the country's largest employers—those included in the Fortune 1000—to weigh in on current and future demand for new hires with 2- and 4-year STEM degrees. As professionals responsible for scouting, recruiting and hiring talent at Fortune 1000 companies, both STEM and non-STEM alike, these individuals are on the frontlines, tasked with assessing and filling their companies' workforce needs. The survey asks the recruiters whether new hires with 2- and 4-year STEM degrees are as, more or less in demand than their peers without STEM degrees? Are more new STEM jobs being created at their companies than non-STEM jobs? Can they find adequate numbers of qualified candidates in a timely manner and how fierce is the competition for STEM degree holders? To answer these and other questions, the survey polled 150 talent recruiters at Fortune 1000 companies, both STEM and non-STEM alike. The survey also asks the recruiters about diversion in STEM, workforce diversity in the pipeline, the role of community colleges in developing the STEM pipeline and the desired skills and competencies of new hires.

Bayer Corporation

2014-10-01

176

Production of epoxy compounds from olefinic compounds  

SciTech Connect

Chlorine and tertiary alkanol dissolved in an inert organic solvent are reacted with aqueous alkali to produce tertiary alkyl hypochlorite which is recovered in the organic solvent and reacted with water and olefinically unsaturated compound to produce chlorohydrin and tertiary alkanol. Chlorohydrin and tertiary alkanol recovered in the organic solvent are contacted with aqueous alkali to produce the epoxy compound, and tertiary alkanol recovered in the organic solvent is recycled to hypochlorite production. The process may be integrated with the electrolytic production of chlorine, with an appropriate treatment of the recycle aqueous stream when required.

Gelbein, A.P.; Kwon, J.T.

1985-01-29

177

Combinatorial materials research applied to the development of new surface coatings XVI: fouling-release properties of amphiphilic polysiloxane coatings.  

PubMed

High-throughput methods were used to prepare and characterize the fouling-release (FR) properties of an array of amphiphilic polysiloxane-based coatings possessing systematic variations in composition. The coatings were derived from a silanol-terminated polydimethylsiloxane, a silanol-terminated polytrifluorpropylmethylsiloxane (CF3-PDMS), 2-[methoxy(polyethyleneoxy)propyl]-trimethoxysilane (TMS-PEG), methyltriacetoxysilane and hexamethyldisilazane-treated fumed silica. The variables investigated were the concentration of TMS-PEG and the concentration of CF3-PDMS. In general, it was found that the TMS-PEG and the CF3-PDMS had a synergist effect on FR properties with these properties being enhanced by combining both compounds into the coating formulations. In addition, reattached adult barnacles removed from coatings possessing both TMS-PEG and relatively high levels of CF3-PDMS displayed atypical base-plate morphologies. The majority of the barnacles removed from these coatings exhibited a cupped or domed base-plate as compared to the flat base-plate observed for the control coating that did not contain TMS-PEG or CF3-PDMS. Coating surface analysis using water contact angle measurements indicated that the presence of CF3-PDMS facilitated migration of TMS-PEG to the coating/air interface during the film formation/curing process. In general, coatings containing both TMS-PEG and relatively high levels of CF3-PDMS possessed excellent FR properties. PMID:25647177

Stafslien, Shane J; Christianson, David; Daniels, Justin; VanderWal, Lyndsi; Chernykh, Andrey; Chisholm, Bret J

2015-02-01

178

XAFS Model Compound Library  

DOE Data Explorer

The XAFS Model Compound Library contains XAFS data on model compounds. The term "model" compounds refers to compounds of homogeneous and well-known crystallographic or molecular structure. Each data file in this library has an associated atoms.inp file that can be converted to a feff.inp file using the program ATOMS. (See the related Searchable Atoms.inp Archive at http://cars9.uchicago.edu/~newville/adb/) This Library exists because XAFS data on model compounds is useful for several reasons, including comparing to unknown data for "fingerprinting" and testing calculations and analysis methods. The collection here is currently limited, but is growing. The focus to date has been on inorganic compounds and minerals of interest to the geochemical community. [Copied, with editing, from http://cars9.uchicago.edu/~newville/ModelLib/

Newville, Matthew

179

Calorimetric, X-Ray Diffraction, and Spectroscopic Studies of the Thermotropic Phase Behavior and Organization of Tetramyristoyl Cardiolipin Membranes  

PubMed Central

The thermotropic phase behavior and organization of aqueous dispersions of the quadruple-chained, anionic phospholipid tetramyristoyl diphosphatidylglycerol or tetramyristoyl cardiolipin (TMCL) was studied by differential scanning calorimetry, x-ray diffraction, 31P NMR, and Fourier-transform infrared (FTIR) spectroscopy. At physiological pH and ionic strength, our calorimetric studies indicate that fully equilibrated aqueous dispersions of TMCL exhibit two thermotropic phase transitions upon heating. The lower temperature transition is much less cooperative but of relatively high enthalpy and exhibits marked cooling hysteresis, whereas the higher temperature transition is much more cooperative and also exhibits a relatively high enthalpy but with no appreciable cooling hysteresis. Also, the properties of these two-phase transitions are sensitive to the ionic strength of the dispersing buffer. Our spectroscopic and x-ray diffraction data indicate that the lower temperature transition corresponds to a lamellar subgel (Lc?) to gel (L?) phase transition and the higher temperature endotherm to a L? to lamellar liquid-crystalline (L?) phase transition. At the Lc?/L? phase transition, there is a fivefold increase of the thickness of the interlamellar aqueous space from ?11 Å to ?50 Å, and this value decreases slightly at the L?/L? phase transition. The bilayer thickness (i.e., the mean phosphate-phosphate distance across the bilayer) increases from 42.8 Å to 43.5 Å at the Lc?/L? phase transition, consistent with the loss of the hydrocarbon chain tilt of ?12°, and decreases to 37.8 Å at the L?/L? phase transition. The calculated cross-sectional areas of the TMCL molecules are ?79 Å2 and ?83 Å2 in the Lc? and L? phases, respectively, and we estimate a value of ?100 Å2 in the L? phase. The combination of x-ray and FTIR spectroscopic data indicate that in the Lc? phase, TMCL molecules possess tilted all-trans hydrocarbon chains packed into an orthorhombic subcell in which the zig-zag planes of the chains are parallel, while in the L? phase the untilted, all-trans hydrocarbon chains possess rotational mobility and are packed into a hexagonal subcell, as are the conformationally disordered hydrocarbon chains in the L? phase. Our FTIR spectroscopic results demonstrate that the four carbonyl groups of the TMCL molecule become progressively more hydrated as one proceeds from the Lc? to the L? and then to the L? phase, while the two phosphate moieties of the polar headgroup are comparably well hydrated in all three phases. Our 31P-NMR results indicate that although the polar headgroup retains some mobility in the Lc? phase, its motion is much more restricted in the L? and especially in the L? phase than that of other phospholipids. We can explain most of our experimental results on the basis of the relatively small size of the polar headgroup of TMCL relative to other phospholipids and the covalent attachment of the two phosphate moieties to a single glycerol moiety, which results in a partially immobilized polar headgroup that is more exposed to the solvent than in other glycerophospholipids. Finally, we discuss the biological relevance of the unique properties of TMCL to the structure and function of cardiolipin-containing biological membranes. PMID:17293402

Lewis, Ruthven N. A. H.; Zweytick, Dagmar; Pabst, Georg; Lohner, Karl; McElhaney, Ronald N.

2007-01-01

180

Preparation of uranium compounds  

SciTech Connect

UI.sub.3(1,4-dioxane).sub.1.5 and UI.sub.4(1,4-dioxane).sub.2, were synthesized in high yield by reacting turnings of elemental uranium with iodine dissolved in 1,4-dioxane under mild conditions. These molecular compounds of uranium are thermally stable and excellent precursor materials for synthesizing other molecular compounds of uranium including alkoxide, amide, organometallic, and halide compounds.

Kiplinger, Jaqueline L; Montreal, Marisa J; Thomson, Robert K; Cantat, Thibault; Travia, Nicholas E

2013-02-19

181

Calorimetric, FTIR and 1H NMR measurements in combination with DFT calculations for monitoring solid-state changes of dynamics of sibutramine hydrochloride.  

PubMed

Two forms of sibutramine hydrochloride, monohydrate and anhydrous, have been investigated by calorimetric methods, Fourier transform infrared (FTIR) absorption and (1) H nuclear magnetic resonance (NMR) measurements as well as by density functional theory (DFT) of vibrational frequencies and infrared intensities, calculations of steric hindrances and Monte Carlo simulations. The results of FTIR spectra combined with DFT calculations permitted identification of the bands corresponding to the dynamics and vibrations of water molecules. NMR study and Monte Carlo simulations revealed the occurrence of reorientation jumps of the methyl groups in sibutramine cation and also revealed that the reorientation of isopropyl group is possible only in sibutramine monohydrate hydrochloride. The hydration of sibutramine hydrochloride causes a change in the conformation of sibutramine cation. PMID:22826266

Pajzderska, Aleksandra; Chudoba, Dorota M; Mielcarek, Jadwiga; W?sicki, Jan

2012-10-01

182

A Search for Low-Mass Weakly Interacting Massive Particles Using Voltage-Assisted Calorimetric Ionization Detection in the SuperCDMS Experiment  

SciTech Connect

SuperCDMS is an experiment designed to directly detect weakly interacting massive particles (WIMPs), a favored candidate for dark matter ubiquitous in the Universe. In this Letter, we present WIMP-search results using a calorimetric technique we call CDMSlite, which relies on voltage-assisted Luke-Neganov amplification of the ionization energy deposited by particle interactions. The data were collected with a single 0.6 kg germanium detector running for ten live days at the Soudan Underground Laboratory. A low energy threshold of (electron equivalent) was obtained, which allows us to constrain new WIMP-nucleon spin-independent parameter space for WIMP masses below 6 GeV/c^2.

Agnese, R.; Anderson, A. J.; Asai, M.; Balakishiyeva, D.; Basu Thakur, R.; Bauer, D. A.; Billard, J.; Borgland, A.; Bowles, M. A.; Brandt, D.; Brink, P. L.; Bunker, R.; Cabrera, B.; Caldwell, D. O.; Cerdeno, D. G.; Chagani, H.; Cooley, J.; Cornell, B.; Crewdson, C. H.; Cushman, Priscilla B.; Daal, M.; Di Stefano, P. C.; Doughty, T.; Esteban, L.; Fallows, S.; Figueroa-Feliciano, E.; Godfrey, G. L.; Golwala, S. R.; Hall, Jeter C.; Harris, H. R.; Hertel, S. A.; Hofer, T.; Holmgren, D.; Hsu, L.; Huber, M. E.; Jastram, A.; Kamaev, O.; Kara, B.; Kelsey, M. H.; Kennedy, A.; Kiveni, M.; Koch, K.; Loer, B.; Lopez Asamar, E.; Mahapatra, R.; Mandic, V.; Martinez, C.; McCarthy, K. A.; Mirabolfathi, N.; Moffatt, R. A.; Moore, D. C.; Nadeau, P.; Nelson, R. H.; Page, K.; Partridge, R.; Pepin, M.; Phipps, A.; Prasad, K.; Pyle, M.; Qiu, H.; Rau, W.; Redi, P.; Reisetter, A.; Ricci, Y.; Saab, T.; Sadoulet, B.; Sander, J.; Schneck, K.; Schnee, Richard; Scorza, S.; Serfass, B.; Shank, B.; Speller, D.; Villano, A. N.; Welliver, B.; Wright, D. H.; Yellin, S.; Yen, J. J.; Young, B. A.; Zhang, J.

2014-01-27

183

Development of a new type of high pressure calorimetric cell, mechanically agitated and equipped with a dynamic pressure control system: Application to the characterization of gas hydrates  

SciTech Connect

A novel prototype of calorimetric cell has been developed allowing experiments under pressure with an in situ agitation system and a dynamic control of the pressure inside the cell. The use of such a system opens a wide range of potential practical applications for determining properties of complex fluids in both pressurized and agitated conditions. The technical details of this prototype and its calibration procedure are described, and an application devoted to the determination of phase equilibrium and phase change enthalpy of gas hydrates is presented. Our results, obtained with a good precision and reproducibility, were found in fairly good agreement with those found in literature, illustrate the various interests to use this novel apparatus.

Plantier, F., E-mail: frederic.plantier@univ-pau.fr; Missima, D.; Torré, J.-P. [Univ Pau and Pays Adour, CNRS, TOTAL - UMR 5150 – LFC-R - Laboratoire des Fluides Complexes et leurs Réservoirs, BP 1155 – PAU, F-64013 (France)] [Univ Pau and Pays Adour, CNRS, TOTAL - UMR 5150 – LFC-R - Laboratoire des Fluides Complexes et leurs Réservoirs, BP 1155 – PAU, F-64013 (France); Marlin, L. [Univ Pau and Pays Adour, IPRA FR2952 - Fédération de Recherche- Atelier de Physique Générale, BP 1155 – PAU, F-64013 (France)] [Univ Pau and Pays Adour, IPRA FR2952 - Fédération de Recherche- Atelier de Physique Générale, BP 1155 – PAU, F-64013 (France)

2013-12-15

184

The calorimetric-respirometric ratio is an on-line marker of enthalpy efficiency of yeast cells growing on a non-fermentable carbon source.  

PubMed

Although on-line calorimetry has been widely used to detect transitions in global metabolic activity during the growth of microorganisms, the relationships between oxygen consumption flux and heat production are poorly documented. In this work, we developed a respirometric and calorimetric approach to determine the enthalpy efficiency of respiration-linked energy transformation of isolated yeast mitochondria and yeast cells under growing and resting conditions. On isolated mitochondria, the analysis of different phosphorylating and non-phosphorylating steady states clearly showed that the simultaneous measurements of heat production and oxygen consumption rates can lead to the determination of both the enthalpy efficiency and the ATP/O yield of oxidative phosphorylation. However, these determinations were made possible only when the net enthalpy change associated with the phosphorylating system was different from zero. On whole yeast cells, it is shown that the simultaneous steady state measurements of the heat production and oxygen consumption rates allow the enthalpy growth efficiency (i.e. the amount of energy conserved as biomass compared to the energy utilised for complete catabolism plus anabolism) to be assessed. This method is based on the comparison between the calorimetric-respirometric ratio (CR ratio) determined under growth versus resting conditions during a purely aerobic metabolism. Therefore, in contrast to the enthalpy balance approach, this method does not rely on the exhaustive and tedious determinations of the metabolites and elemental composition of biomass. Thus, experiments can be performed in the presence of non-limiting amounts of carbon substrate, an approach which has been successfully applied to slow growing cells such as yeast cells expressing wild-type or a mutant rat uncoupling protein-1. PMID:11115644

Dejean, L; Beauvoit, B; Bunoust, O; Fleury, C; Guérin, B; Rigoulet, M

2001-01-19

185

Analysis of protein-surfactant interactions--a titration calorimetric and fluorescence spectroscopic investigation of interactions between Humicola insolens cutinase and an anionic surfactant.  

PubMed

We have studied interactions of cutinase (HiC) from Humicula insolens and sodium dodecyl sulphate (SDS) by parallel calorimetric and fluorescence investigations of systems in which the concentration of both components was changed systematically. Results from the two methods exhibit a number of synchronous characteristics, when plotted against the total SDS concentration, [SDS]tot. The molecular origin of several of these anomalies was assigned, and five intervals of [SDS]tot in which different modes of interactions dominated were identified. Going from low to high [SDS]tot, these modes were: binding of (a few) SDS to native HiC, formation of oligomeric protein aggregates, denaturation of HiC and adsorption of SDS on denatured protein. For [SDS]tot>3-6 mM (depending on the protein concentration), the adsorption saturated, and no further protein-detergent interaction could be detected. Two particularly conspicuous anomalies in the calorimetric data were ascribed to respectively denaturation and saturation. It was found that [SDS]tot at these points depended linearly on the (total) protein concentration, [HiC]. We suggest that this reflects the balance between bound and free SDS [SDS]tot=[SDS]aq+[HiC] Nb where [SDS]aq and Nb are, respectively, the aqueous ("free") concentration of SDS and the average number of SDS bound per protein. Interpretation of the results along these lines showed that at 22 degrees C and pH 7.0, HiC denatures with approximately 14 bound surfactant molecules at [SDS]aq=1.0 mM. Saturation is characterized by Nb approximately 39 and [SDS]aq=2.2 mM. The latter value is equal to CMC in the (protein free) buffer. These results are discussed with respect to the SDS-binding capacity of HiC and the origin and location of the saturation point. PMID:16162423

Nielsen, Anders D; Arleth, Lise; Westh, Peter

2005-09-25

186

Types of Compound Leaves  

NSDL National Science Digital Library

This illustrated guide is designed to help students recognize and learn the different types of compound leaves. The single Web page can be easily printed for use at field sites. Along with a short description, an illustration that identifies a leaflet and petiole is included for four types of compound leaves.

187

Improving ITC studies of cyclodextrin inclusion compounds by global analysis of conventional and non-conventional experiments  

PubMed Central

Summary The study of 1:1 cyclodextrin inclusion compounds by isothermal titration calorimetry was explored in a theoretical and experimental point of view to compare the efficiency of conventional and non-conventional experiments. All direct and competitive protocols were described and evaluated in terms of accuracy on both binding constant and inclusion enthalpy. Significant improvement in the calorimetric characterization may be obtained by means of the global analysis of non-conventional experiments coupled to the standard titration protocol. While the titration-release approach proved to be the most accurate strategy for classical complexations, the valuable contribution of other non-conventional experiments was demonstrated for issues concerning weak stability, enthalpy, or solubility. PMID:25550724

Bertaut, Eléonore

2014-01-01

188

Heart testing compound  

DOEpatents

The compound 15-(p-[.sup.125 I]-iodophenyl)-6-tellurapentadecanoic acid is disclosed as a myocardial imaging agent having rapid and pronounced uptake, prolonged myocardial retention, and low in vivo deiodination.

Knapp, Jr., Furn F. (Oak Ridge, TN); Goodman, Mark M. (Knoxville, TN)

1985-01-01

189

Ringed-Carbon Compounds  

NSDL National Science Digital Library

In this interactive activity adapted from NOVA, learn about alkaloids and steroids, both examples of compounds with carbon rings. Short videos with interviews,animations, and photographs are featured.

WGBH Educational Foundation

2007-02-12

190

Anti-Fog Compound  

NASA Technical Reports Server (NTRS)

Tracer Chemical Corporation's TRX Anti-Fog Composition is an inexpensive product which prevents condensation on plastic and glass surfaces. It was the result from a Tech Briefs article detailing a Johnson Space Center compound.

1985-01-01

191

Intercalation compounds of graphite  

Microsoft Academic Search

A broad review of recent research work on the preparation and the remarkable properties of intercalation compounds of graphite, covering a wide range of topics from the basic chemistry, physics and materials science to engineering applications.

M. S. Dresselhaus; G. Dresselhaus

1981-01-01

192

Intercalation compounds of graphite  

Microsoft Academic Search

A broad review of recent research work on the preparation and the remarkable properties of intercalation compounds of graphite, covering a wide range of topics from the basic chemistry, physics and materials science to engineering applications.

M. S. Dresselhaus; G. Dresselhaus

2002-01-01

193

Compound Independent Events  

NSDL National Science Digital Library

Compare the theoretical and experimental probabilities of compound independent events by drawing colored marbles from a bag. Record the results of successive draws with or without replacement of marbles to calculate the experimental probability.

2007-12-12

194

Heart testing compound  

DOEpatents

The compound 15-(p-(/sup 125/I)-iodophenyl)-6-tellurapentadecanoic acid is disclosed as a myocardial imaging agent having rapid and pronounced uptake, prolonged myocardial retention, and low in vivo deiodination.

Knapp, F.F. Jr.; Goodman, M.M.

1983-06-29

195

Chemistry of peroxide compounds  

NASA Technical Reports Server (NTRS)

The history of Soviet research from 1866 to 1967 on peroxide compounds is reviewed. This research dealt mainly with peroxide kinetics, reactivity and characteristics, peroxide production processes, and more recently with superoxides and ozonides and emphasis on the higher oxides of group 1 and 2 elements. Solid state fluidized bed synthesis and production of high purity products based on the relative solubilities of the initial, intermediate, and final compounds and elements in liquid ammonia are discussed.

Volnov, I. I.

1981-01-01

196

Phenolic Molding Compounds  

NASA Astrophysics Data System (ADS)

Phenolic Molding Compounds continue to exhibit well balanced properties such as heat resistance, chemical resistance, dimensional stability, and creep resistance. They are widely applied in electrical, appliance, small engine, commutator, and automotive applications. As the focus of the automotive industry is weight reduction for greater fuel efficiency, phenolic molding compounds become appealing alternatives to metals. Current market volumes and trends, formulation components and its impact on properties, and a review of common manufacturing methods are presented. Molding processes as well as unique advanced techniques such as high temperature molding, live sprue, and injection/compression technique provide additional benefits in improving the performance characterisitics of phenolic molding compounds. Of special interest are descriptions of some of the latest innovations in automotive components, such as the phenolic intake manifold and valve block for dual clutch transmissions. The chapter also characterizes the most recent developments in new materials, including long glass phenolic molding compounds and carbon fiber reinforced phenolic molding compounds exhibiting a 10-20-fold increase in Charpy impact strength when compared to short fiber filled materials. The role of fatigue testing and fatigue fracture behavior presents some insight into long-term reliability and durability of glass-filled phenolic molding compounds. A section on new technology outlines the important factors to consider in modeling phenolic parts by finite element analysis and flow simulation.

Koizumi, Koji; Charles, Ted; de Keyser, Hendrik

197

Effects of methoxy and formyl substituents on the energetics and reactivity of ?-naphthalenes: a calorimetric and computational study.  

PubMed

A combined experimental and computational study was developed to evaluate and understand the energetics and reactivity of formyl and methoxy ?-naphthalene derivatives. Static bomb combustion calorimetry and the Calvet microcalorimetry were the experimental techniques used to determine the standard (p(o)=0.1 MPa) molar enthalpies of formation, in the liquid phase, ?fHm(o)(l), and of vaporization, ?l(g)Hm(o), at T=298.15K, respectively, of the two liquid naphthalene derivatives. Those experimental values were used to derive the values of the experimental standard molar enthalpies of formation, in the gaseous phase, ?fHm(o)(g), of 1-methoxynaphthalene, (-3.0 ± 3.1)kJmol(-1), and of 1-formylnaphthalene, (36.3 ± 4.1)kJ mol(-1). High-level quantum chemical calculations at the composite G3(MP2)//B3LYP level were performed to estimate the values of the ?fHm(o)(g) of the two compounds studied resulting in values in very good agreement with experimental ones. Natural bond orbital (NBO) calculations were also performed to determine more about the structure and reactivity of this class of compounds. PMID:24444416

Silva, Ana L R; Freitas, Vera L S; Ribeiro da Silva, Maria D M C

2014-07-01

198

Electrical properties, phase transitions and conduction mechanisms of the [(C2H5)NH3]2CdCl4 compound  

NASA Astrophysics Data System (ADS)

The [(C2H5)NH3]2CdCl4 hybrid material was prepared and its calorimetric study and electric properties were investigated at low temperature. The X-ray powder diffractogram has shown that the compound is crystallized in the orthorhombic system with Abma space group, and the refined unit cell parameters are a=7.546 Å, b=7.443 Å, and c=21.831 Å. The calorimetric study has revealed two endothermic peaks at 216 K and 357 K, which are confirmed by the variation of fp and ?dc as a function of temperature. The equivalent circuit based on the Z-View-software was proposed and the conduction mechanisms were determined. The obtained results have been discussed in terms of the correlated barrier hopping model (CBH) in phase I (low temperature (OLT)), non-overlapping small polaron tunneling model (NSPT) in phase II (room temperature (ORT)) and the overlapping large polaron tunneling model in phase III (high temperature (OHT)). The density of localized states NF(E) at the Fermi level and the binding energy Wm were calculated. The variation of the dielectric loss log(??) with log(?) was found to follow the empirical law, ??=B ?m(T).

Mohamed, C. Ben; Karoui, K.; Saidi, S.; Guidara, K.; Rhaiem, A. Ben

2014-10-01

199

Sulfur compounds in coal  

NASA Technical Reports Server (NTRS)

The literature on the chemical structure of the organic sulfur compounds (or functional groups) in coal is reviewed. Four methods were applied in the literature to study the sulfur compounds in coal: direct spectrometric and chemical analysis, depolymerization in drastic conditions, depolymerization in mild conditions, and studies on simulated coal. The data suggest that most of the organic sulfur in coal is in the form of thiophenic structures and aromatic and aliphatic sulfides. The relative abundance of the sulfur groups in bituminous coal is estimated as 50:30:20%, respectively. The ratio changes during processing and during the chemical analysis. The main effects are the transformation during processing of sulfides to the more stable thiophenic compounds and the elimination of hydrogen sulfide.

Attar, A.; Corcoran, W. H.

1977-01-01

200

Metalloid compounds as drugs  

PubMed Central

The six elements commonly known as metalloids are boron, silicon, germanium, arsenic, antimony, and tellurium. Metalloid containing compounds have been used as antiprotozoal drugs. Boron-based drugs, the benzoxaboroles have been exploited as potential treatments for neglected tropical diseases. Arsenic has been used as a medicinal agent and arsphenamine was the main drug used to treat syphilis. Arsenic trioxide has been approved for the treatment of acute promyelocytic leukemia. Pentavalent antimonials have been the recommended drug for visceral leishmaniasis and cutaneous leishmaniasis. Tellurium (IV) compounds may have important roles in thiol redox biological activity in the human body, and ammonium trichloro (dioxoethylene-O, O’-)tellurate (AS101) may be a promising agent for the treatment of Parkinson’s disease. Organosilicon compounds have been shown to be effective in vitro multidrug-resistance reverting agents. PMID:24019824

Sekhon, B. S.

2013-01-01

201

Biodegradation of perfluorinated compounds.  

PubMed

The information available in the literature provides evidence for the biodegradation of some poly- and per-fluorinated compounds, but such biodegradation is incomplete and may not result in mineralization. Recent publications have demonstrated that 8:2 fluorotelomer alcohol, for example, can be degraded by bacteria from soil and wastewater treatment plants to perfluorooctanoic acid. Similarly, 2-N-ethyl(perfluorooctane sulfonamido)ethanol can be degraded by wastewater treatment sludge to perfluorooctanesulfonate. It is presently unclear whether these two products are degraded further. Therefore, the question remains as to whether there is a potential for defluorination and biodegradation of PFCs that contributes significantly to their environmental fate. The lack of mineralization observed is probably caused by the stability of the C-F bond, although there are examples of microbially catalyzed defluorination reactions. As is the case with reductive dechlorination or debromination, reductive defluorination is energetically favorable under anaerobic conditions and releases more energy than that available from sulfate reduction or methanogenesis. Consequently, we should consider the possibility that bacteria will adapt to utilize this source of energy, although evolving mechanisms to overcome the kinetic barriers to degradation of these compounds may take some time. The fact that such reactions are absent for some PFCs, to date, may be because too little time has passed for microorganisms to adapt to these potential substrates. Hence, the situation may be comparable to that of chlorinated organic compounds several decades ago. For many years, organochlorine compounds were considered to be catabolically recalcitrant; today, reductive chlorination reactions of many organochlorines, including PCBs and dioxins, are regularly observed in anaerobic environments. Hence, it is opportune and important to continue studying the potential degradation of perfluorinated compounds in carefully designed experiments with either microbial populations from contaminated sites or cultures of bacteria known to dehalogenate chlorinated compounds. PMID:19025092

Parsons, John R; Sáez, Monica; Dolfing, Jan; de Voogt, Pim

2008-01-01

202

Microoptical compound lens  

DOEpatents

An apposition microoptical compound lens comprises a plurality of lenslets arrayed around a segment of a hollow, three-dimensional optical shell. The lenslets collect light from an object and focus the light rays onto the concentric, curved front surface of a coherent fiber bundle. The fiber bundle transports the light rays to a planar detector, forming a plurality of sub-images that can be reconstructed as a full image. The microoptical compound lens can have a small size (millimeters), wide field of view (up to 180.degree.), and adequate resolution for object recognition and tracking.

Sweatt, William C. (Albuquerque, NM); Gill, David D. (Albuquerque, NM)

2007-10-23

203

Calorimetric determination of the angular dependent phase diagram of an S=1/2 Heisenberg triangular-lattice antiferromagnet  

NASA Astrophysics Data System (ADS)

An antiferromagnetic system on a 2-D triangular lattice leads to geometric topological frustration. This ideal system has been the subject of theoretical investigations. One experimental realization of this system is the compound Cs2CuCl4. Various magnetization, heat capacity, neutron scattering and NMR studies have identified several magnetic transitions when the magnetic field is applied along one of the three principal axes. The current work investigates the evolution of these phases at intermediate angles as the crystal is rotated relative to the magnetic field. These phases were investigated using a novel rotating calorimeter allowing complete coverage of the experimental parameter space. New magnetic phases only existing at intermediate angles have been found.

Hannahs, S. T.; Fortune, N. A.; Park, J.-H.; Takano, Y.; Ono, T.; Tanaka, H.

2014-12-01

204

Calorimetric and computational study of 1,3-dithiacyclohexane 1,1-dioxide (1,3-dithiane sulfone).  

PubMed

The enthalpies of combustion and sublimation of 1,3-dithiacyclohexane 1,1-dioxide (1,3-dithiane sulfone) were measured by a rotating-bomb combustion calorimeter and the Knudsen effusion technique, and the gas-phase enthalpy of formation was determined, Delta(f)H(m)*(g) = -326.3 +/- 2.0 kJ mol(-1). Standard ab initio molecular orbital calculations at the G2(MP2) level were performed, and a theoretical study on molecular and electronic structure of the compound has been carried out. Calculated Delta(f)H(m)*(g) values agree very well with the experimental one. These experimental and theoretical studies support the relevance of the repulsive electrostatic interaction between sulfur atoms in 1,3-dithiane sulfone, that apparently counterbalances any n(S) --> rho(C-SO2)* stabilizing hyperconjugative interaction. PMID:14987027

Roux, María Victoria; Temprado, Manuel; Jiménez, Pilar; Notario, Rafael; Guzmán-Mejía, Ramón; Juaristi, Eusebio

2004-03-01

205

CHAPTER XVI TUNICATES AND LANCELETS  

E-print Network

to the vertebrates and are included with them in the phYlum Chordata to which the higher animals, InclUding man, belong. In modern classifications they are given the rank vf a subphylum of the Chordata. They are

206

PREFACE: Sensors & their Applications XVI  

NASA Astrophysics Data System (ADS)

This volume records the Proceedings of the sixteenth conference in the biennial Sensors and Their Applications series which took place at the Clarion Hotel, Cork, Ireland between 12-14 September 2011. The conference is organized by the Instrument Science and Technology Group of the Institute of Physics. On this occasion, the conference was hosted by Tyndall National Institute at University College Cork. This year the conference returns to Ireland, having last been held in Limerick in 2003. The conference proceedings record the continuing growth of the sensors community nationally and internationally. The conferences bring together contributions from scientists and engineers from academia, research institutes and industrial establishments, and therefore provide an excellent opportunity for these communities to present and discuss the latest results in the field of sensors, instrumentation and measurement. Amongst the more traditional themes, such as optical sensing, there is growth in new areas such as biomedical sensing and instrumentation, and nanosensing, which is reflected in this volume. Similarly the contribution of modelling and simulation techniques in sensor and instrumentation design and their applications is acknowledged by a session in this area. The sessions across the conference are supported by notable contributions from invited speakers. We would like to thank all of our colleagues in the sensor and instrumentation community who have supported this event by contributing manuscripts. Our thanks also go to Tyndall National Institute for hosting this conference and all the sponsors who, with their generous financial and in-kind contributions, enabled the better organization of this conference. We would also like to thank all the members of the Instrument Science and Technology Group for their support, and in particular for refereeing the submitted manuscripts. We are also pleased to express our thanks to the Conference Department of the Institute of Physics for their invaluable support in organising this event. We are especially grateful to Dawn Stewart for her responsive and efficient day-to-day handling of this event, as well as to Claire Garland for her planning and management of this event. We hope that the conference authors, participants and a wider audience will find these proceedings to be of interest and to serve as a useful reference text. Panicos KyriacouConference ChairmanAlan O'RiordanConference Local Chairman

Kyriacou, Panicos; O'Riordan, Alan

2011-08-01

207

Electromagnetic and calorimetric measurements for AC losses of a YBa2Cu3O7-? coated conductor with Ni-alloy substrate  

NASA Astrophysics Data System (ADS)

The AC losses of a rolling-assisted-biaxially-textured-substrate (RABiTS™) processed YBa2Cu3O7-? (YBCO) coated conductor (Goyal et al 1996 Appl. Supercond. 4 403-27) with Ni-alloy substrate and Cu stabilizer were measured at 77 K by both calorimetric (CM) and electromagnetic (EM) methods. In the CM method, improvements in the measurement were observed when a Cernox temperature sensor was used to measure the temperature rise on the sample instead of a differential thermocouple. The effect of heat transferred from current leads was taken into account to improve the accuracy of the CM results. In the EM method, the magnetization losses of the sample in a perpendicular applied field were measured by an in-plane pick-up coil. The calculation of the calibration factor C of the pick-up coil is discussed. Good agreement between AC loss results obtained from the CM and EM methods confirmed the validity of our measurements and calculations.

Nguyen, D. N.; Sastry, P. V. P. S. S.; Knoll, D. C.; Schwartz, J.

2006-10-01

208

Ferric ion (hydr)oxo clusters in the "Venus flytrap" cleft of FbpA: Mössbauer, calorimetric and mass spectrometric studies.  

PubMed

Isothermal calorimetric studies of the binding of iron(III) citrate to ferric ion binding protein from Neisseria gonorrhoeae suggested the complexation of a tetranuclear iron(III) cluster as a single step binding event (apparent binding constant K(app) (ITC) = 6.0(5) × 10(5) M(-1)). High-resolution Fourier transform ion cyclotron resonance mass spectrometric data supported the binding of a tetranuclear oxo(hydroxo) iron(III) cluster of formula [Fe(4)O(2)(OH)(4)(H(2)O)(cit)](+) in the interdomain binding cleft of FbpA. The mutant H9Y-nFbpA showed a twofold increase in the apparent binding constant [K(app) (ITC) = 1.1(7) × 10(6) M(-1)] for the tetranuclear iron(III) cluster compared to the wild-type protein. Mössbauer spectra of Escherichia coli cells overexpressing FbpA and cultured in the presence of added (57)Fe citrate were indicative of the presence of dinuclear and polynuclear clusters. FbpA therefore appears to have a strong affinity for iron clusters in iron-rich environments, a property which might endow the protein with new biological functions. PMID:22349975

Mukherjee, Arindam; Bilton, Paul R; Mackay, Logan; Janoschka, Adam; Zhu, Haizhong; Rea, Dean; Langridge-Smith, Pat R R; Campopiano, Dominic J; Teschner, Thomas; Trautwein, Alfred X; Schünemann, Volker; Sadler, Peter J

2012-04-01

209

Aminopropyl thiophene compounds  

DOEpatents

Radiopharmaceuticals useful in brain imaging comprising radiohalogenated thienylethylamine derivatives. The compounds are 5-halo-thiophene-2-isopropyl amines able to cross the blood-brain barrier and be retained for a sufficient length of time to allow the evaluation of regional blood flow by radioimaging of the brain.

Goodman, Mark M. (Knoxville, TN); Knapp, Jr., Furn F. (Oak Ridge, TN)

1990-01-01

210

Fun with Ionic Compounds  

ERIC Educational Resources Information Center

Ionic bonding is a fundamental topic in high school chemistry, yet it continues to be a concept that students struggle to understand. Even if they understand atomic structure and ion formation, it can be difficult for students to visualize how ions fit together to form compounds. This article describes several engaging activities that help…

Logerwell, Mollianne G.; Sterling, Donna R.

2007-01-01

211

8-fluoropurine compounds  

DOEpatents

An efficient, regiocontrolled approach to the synthesis of 8-fluoropurines by direct fluorination of purines with dilute elemental fluorine, or acetyl hypofluorite, is provided. In a preferred embodiment, a purine compound is dissolved in a polar solvent and reacted with a dilute mixture of F.sub.2 in He or other inert gas.

Barrio, Jorge R. (Agoura Hills, CA); Satyamurthy, Nagichettiar (Los Angeles, CA); Namavari, Mohammad (Los Angeles, CA); Phelps, Michael E. (Encino, CA)

2001-01-01

212

Noun Compounding in Thai.  

ERIC Educational Resources Information Center

The present study, a slightly revised version of the author's 1968 Ph.D. thesis presented to the University of Chicago, investigates compound formation in Thai. Chapter 1 summarizes the transformational generative theory on which the study is based, discusses the concept that Thai is a "simple" language in comparison with English, and briefly…

Fasold, Ralph William August

213

PERSISTENT PERFLUORINATED ORGANIC COMPOUNDS  

EPA Science Inventory

Perfluorinated compounds (PFCs) have gained notoriety in the recent past. Global distribution of PFCs in wildlife, environmental samples and humans has sparked a recent increase in new investigations concerning PFCs. Historically PFCs have been used in a wide variety of consume...

214

Compound floating pivot micromechanisms  

DOEpatents

A new class of tilting micromechanical mechanisms have been developed. These new mechanisms use compound floating pivot structures to attain far greater tilt angles than are practical using other micromechanical techniques. The new mechanisms are also capable of bi-directional tilt about multiple axes.

Garcia, Ernest J. (Albuquerque, NM)

2001-04-24

215

Compound Chondrules fused Cold  

E-print Network

About 4-5% of chondrules are compound: two separate chondrules stuck together. This is commonly believed to be the result of the two component chondrules having collided shortly after forming, while still molten. This allows high velocity impacts to result in sticking. However, at T ~ 1100K, the temperature below which chondrules collide as solids (and hence usually bounce), coalescence times for droplets of appropriate composition are measured in tens of seconds. Even at 1025K, at which temperature theory predicts that the chondrules must have collided extremely slowly to have stuck together, the coalescence time scale is still less than an hour. These coalescence time scales are too short for the collision of molten chondrules to explain the observed frequency of compound chondrules. We suggest instead a scenario where chondrules stuck together in slow collisions while fully solid; and the resulting chondrule pair was subsequently briefly heated to a temperature in the range of 900-1025K. In that temperatur...

Hubbard, Alexander

2015-01-01

216

Arsonium compounds in algae.  

PubMed

Search for a precursor of the arsenobetaine discovered in Western Australian rock lobster tail muscle has led to an algal metabolite of radioarsenate having the properties of a trimethylarsoniumriboside derivative of the major arsenicals of aquatic plants, dimethylarsinoylribosylglycerol, its sulfate ester, and the corresponding riboside of phosphatidylglycerol. Such an arsonium compound could serve as metabolic precursor of arsenobetaine, the innocuous arsenical component of many marine food products. The oceanic diatom, Chaetoceros gracilis, cultured in radioarsenate produced a compound whose chemical, chromatographic, and electrophoretic properties are described. It was found to be identical to the trimethylarsonium derivative synthesized from the major algal arsenical, 1-(5'-dimethylarsinoyl-5'-deoxyribosyl)glycerol-3-O -sulfate. PMID:16594059

Benson, A A

1989-08-01

217

Structures and standard molar enthalpies of formation of a series of Ln(III)-Cu(II) heteronuclear compounds with pyrazine-2,3-dicarboxylic acid  

NASA Astrophysics Data System (ADS)

Fifteen lanthanide-copper heteronuclear compounds, formulated as [CuLn2(pzdc)4(H2O)6]·xH2O (1-6(x=2), 8(x=3), 9-10(x=4); [CuLn2(pzdc)4(H2O)4]·xH2O (7, 12-13, 15(x=4), 14(x=5), 11(x=8) (Ln(III)=La(1); Ce(2); Pr(3); Nd(4); Sm(5); Eu(6); Gd(7); Tb(8); Dy(9); Ho(10); Er(11); Tm(12); Yb(13); Lu(14); Y(15); H2pzdc (C6H4N2O4)=pyrazine-2,3-dicarboxylic acid) have been hydrothermally synthesized. All compounds were characterized by element analysis, IR spectroscopy, single-crystal X-ray diffraction and thermal analysis. X-ray diffraction analyses confirm that all compounds are isostructural and feature a 3D brick-like framework structure with {4.62}2{42.62.82}{63}2{65.8}2 topology. Using 1 mol cm-3 HCl(aq) as calorimetric solvent, with an isoperibol solution-reaction calorimeter, the standard molar enthalpies of formation of all compounds were determined by a designed thermochemical cycle. In addition, solid state luminescence properties of compounds 5, 6, 8 and 9 were studied in the solid state.

Yang, Qi; Xie, Gang; Wei, Qing; Chen, Sanping; Gao, Shengli

2014-07-01

218

Compound cycle engine program  

NASA Technical Reports Server (NTRS)

The Compound Cycle Engine (CCE) is a highly turbocharged, power compounded power plant which combines the lightweight pressure rise capability of a gas turbine with the high efficiency of a diesel. When optimized for a rotorcraft, the CCE will reduce fuel burned for a typical 2 hr (plus 30 min reserve) mission by 30 to 40 percent when compared to a conventional advanced technology gas turbine. The CCE can provide a 50 percent increase in range-payload product on this mission. A program to establish the technology base for a Compound Cycle Engine is presented. The goal of this program is to research and develop those technologies which are barriers to demonstrating a multicylinder diesel core in the early 1990's. The major activity underway is a three-phased contract with the Garrett Turbine Engine Company to perform: (1) a light helicopter feasibility study, (2) component technology development, and (3) lubricant and material research and development. Other related activities are also presented.

Bobula, G. A.; Wintucky, W. T.; Castor, J. G.

1986-01-01

219

High temperature high pressure thermodynamic measurements for coal model compounds. Semiannual technical progress report, September 1, 1995--February 29, 1996  

SciTech Connect

The overall objective of this project is to develop a better thermodynamic model for predicting properties of high-boiling coal derived liquids, especially the phase equilibria of different fractions at elevated temperatures and pressures. The development of such a model requires data on vapor-liquid equilibria (VLE), enthalpy, and heat capacity which would be experimentally determined for binary systems of coal model compounds and compiled into a database. The data will be used to refine existing models such as UNIQUAC and UNIFAC. A M.S. graduate student Mr. Ahmad Al-Ghamdi has been recruited to work on this project. The flow VLE apparatus designed and built for a previous project has been upgraded and recalibrated for data measurements for this project. The modifications include better and more accurate sampling technique and addition of a digital recorder to monitor temperature, pressure and liquid level inside the VLE cell. VLE data measurements for system benzene-ethylbenzene have begun. The vapor and liquid compositions will be measured using the Perkin-Elmer Auto-system gas chromatograph. A capillary column made by Supelco has been purchased for the analysis. For enthalpy and heat capacity measurements, SETARAM C-80 calorimeter has been purchased and installed. The instrument can be used for calorimetric property measurements at temperatures up to 300{degree}C and pressures up to 1500 psi. Enthalpy measurements for the system benzene-ethylbenzene have begun. Simultaneously, we have undertaken the design of a calorimetric cell that will allow enthalpy measurements at pressures up to 10000 psi. In this report the VLE apparatus and the preliminary work completed for the VLE measurements for the benzene-ethylbenzene system are described. A description of the calorimeter and the measured enthalpy data for the benzene-ethylbenzene system will be included in the next report. 3 figs., 5 tabs.

Kabadi, V.N. [North Carolina Agricultural and Technical State Univ., Greensboro, NC (United States). Dept. of Chemical Engineering] [North Carolina Agricultural and Technical State Univ., Greensboro, NC (United States). Dept. of Chemical Engineering; Chen, J.C. [North Carolina Agricultural and Technical State Univ., Greensboro, NC (United States). Dept. of Mechanical Engineering] [North Carolina Agricultural and Technical State Univ., Greensboro, NC (United States). Dept. of Mechanical Engineering

1996-10-01

220

Phenolic compounds in Catharanthus roseus  

Microsoft Academic Search

Besides alkaloids Catharanthus roseus produces a wide spectrum of phenolic compounds, this includes C6C1 compounds such as 2,3-dihydoxybenzoic acid, as well as\\u000a phenylpropanoids such as cinnamic acid derivatives, flavonoids and anthocyanins. The occurrence of these compounds in C. roseus is reviewed as well as their biosynthesis and the regulation of the pathways. Both types of compounds compete with the indole

Natali Rianika Mustafa; Robert Verpoorte

2007-01-01

221

Bilingual Reading of Compound Words  

Microsoft Academic Search

The present study investigated whether bilingual readers activate constituents of compound words in one language while processing\\u000a compound words in the other language via decomposition. Two experiments using a lexical decision task were conducted with\\u000a adult Korean-English bilingual readers. In Experiment 1, the lexical decision of real English compound words was more accurate\\u000a when the translated compounds (the combination of

In Yeong Ko; Min Wang; Say Young Kim

2011-01-01

222

Offset Compound Gear Drive  

NASA Technical Reports Server (NTRS)

The Offset Compound Gear Drive is an in-line, discrete, two-speed device utilizing a special offset compound gear that has both an internal tooth configuration on the input end and external tooth configuration on the output end, thus allowing it to mesh in series, simultaneously, with both a smaller external tooth input gear and a larger internal tooth output gear. This unique geometry and offset axis permits the compound gear to mesh with the smaller diameter input gear and the larger diameter output gear, both of which are on the same central, or primary, centerline. This configuration results in a compact in-line reduction gear set consisting of fewer gears and bearings than a conventional planetary gear train. Switching between the two output ratios is accomplished through a main control clutch and sprag. Power flow to the above is transmitted through concentric power paths. Low-speed operation is accomplished in two meshes. For the purpose of illustrating the low-speed output operation, the following example pitch diameters are given. A 5.0 pitch diameter (PD) input gear to 7.50 PD (internal tooth) intermediate gear (0.667 reduction mesh), and a 7.50 PD (external tooth) intermediate gear to a 10.00 PD output gear (0.750 reduction mesh). Note that it is not required that the intermediate gears on the offset axis be of the same diameter. For this example, the resultant low-speed ratio is 2:1 (output speed = 0.500; product of stage one 0.667 reduction and stage two 0.750 stage reduction). The design is not restricted to the example pitch diameters, or output ratio. From the output gear, power is transmitted through a hollow drive shaft, which, in turn, drives a sprag during which time the main clutch is disengaged.

Stevens, Mark A.; Handschuh, Robert F.; Lewicki, David G.

2010-01-01

223

Titanium alkoxide compound  

DOEpatents

A titanium alkoxide composition is provided, as represented by the chemical formula (OC.sub.6H.sub.5N).sub.2Ti(OC.sub.6H.sub.5NH.sub.2).sub.2. As prepared, the compound is a crystalline substance with a hexavalent titanium atom bonded to two OC.sub.6H.sub.5NH.sub.2 groups and two OC.sub.6H.sub.5N groups with a theoretical molecular weight of 480.38, comprising 60.01% C, 5.04% H and 11.66% N.

Boyle, Timothy J. (Albuquerque, NM)

2007-08-14

224

Boronated porphyrin compounds  

DOEpatents

A compound is described having the structure ##STR1## where R preferably is ##STR2## and most preferably R.sup.3 is a closo-carborane and R.sup.2 is --H, an alkyl or aryl having 1 to about 7 carbon atoms, This invention was made with Government support under NIH Grant No. CA-37961 awarded by the Department of Health and Human Services and under the Associated Universities Inc. Contract No. De-AC02-76CH00016 with the U.S. Department of Energy. The Government has rights in this invention.

Kahl, S.B.; Koo, M.S.

1992-09-22

225

Boronated porphyrin compounds  

DOEpatents

A compound is described having the structure ##STR1## where R preferably is ##STR2## and most preferably R.sup.3 is a closo-carborane and R.sup.2 is --H, an alkyl or aryl having 1 to about 7 carbon atoms, This invention was made with Government support under NIH Grant No. CA-37961 awarded by the Department of Health and Human Services and under the Associated Universities Inc. Contract No. De-AC02-76CH00016 with the U.S. Department of Energy. The Government has rights in this invention.

Kahl, Stephen B. (Portola Valley, CA); Koo, Myoung-Seo (San Francisco, CA)

1992-01-01

226

Terahertz plastic compound lenses.  

PubMed

We present terahertz (THz) lenses made of highly refracting polymeric compounds which provide a better focusing performance and an increased functionality in comparison to conventional THz lenses. Using mixtures consisting of polypropylene (PP) and alumina as well as PP and zinc sulfide allows a significant increase of the refractive index while simultaneously keeping a low extinction and dispersion. With these new material combinations, lenses with an increased focusing capability are realized. This is evaluated by focal plane measurements using a fiber coupled THz time-domain spectrometer. PMID:23842159

Wichmann, M; Mondol, A S; Kocic, N; Lippert, S; Probst, T; Schwerdtfeger, M; Schumann, S; Hochrein, T; Heidemeyer, P; Bastian, M; Bastian, G; Koch, M

2013-06-20

227

The use of selective extraction chromatographic columns as an alternative to solvent extraction for the separation of uranium followed by the use of Arsenazo III as a calorimetric reagent for uranium determination  

SciTech Connect

The use of U/TEVA{reg_sign} Spec columns as an alternative to solvent extraction for separation of uranium prior to its determination by various techniques (calorimetric, phosphorescence, and mass spectroscopy) was investigated. U/TEVA{reg_sign} Spec columns have several advantages over the widely used 4-methyl-2-pentanone solvent extraction method. Among the advantages are: (1) no hazardous liquid organic waste, that creates regulatory waste disposal problems, is generated; (2) a clean separation of U from Zr, F, and fission products is obtained; (3) the sample preparation time is reduced; and (4) the exposure of analysts to ionizing radiation is reduced because the entire procedure may be performed in a hot cell using remote operations. This study also investigated the use of Arsenazo III (1,8-dihydroxynapthalene-3,6-disulfonic acid-2,7-bis [<-azo-2>-phenylarsonic acid]) as a calorimetric reagent to determine uranium concentrations over a wide range in waste streams and product streams at the Idaho Chemical Processing Plant. Process and waste stream samples were passed through a U/TEVA{reg_sign} Spec column to selectively remove the uranium. The uranium bearing fraction is compatible with the pH range for color development with Arsenazo III. Arsenazo III may be added to the uranium fraction, at a 3:1 mole ratio (Arsenazo:Uranium) at the high end of the method (10 {mu}/mL). Arsenazo III forms a highly stable complex with uranium. Stability tests from this and other studies show that the colored complex of Arsenazo III with U(VI) forms within one minute and remains stable for several hours. The complex with U(VI) varies in color with pH. However, with excess reagent, the color is varying shades of purple. Since the samples were passed through a highly selective extraction chromatographic column prior to adding the calorimetric reagent, no interferences were observed.

Miller, C.J.; Del Mastro, J.R.

1994-10-01

228

Biomimetic microfabricated compound eyes  

NASA Astrophysics Data System (ADS)

Over the past century, compound eyes in nature have been one of the most studied and intriguing topics in physiological optics due to their unique optical scheme for imaging. Hundreds to ten thousands of integrated optical units called ommatidia are spherically arranged along a curvilinear surface and point in different directions. Each ommatidium collects light within a small angular acceptance and collectively they construct a full image with a wide field-of-view. In this work, artificial compound eye lenses with three-dimensional configuration, which are anatomically and functionally similar to those in nature, have been synthesized using a photosensitive polymer resin by utilizing microlens technology, self-written waveguide process, and soft lithography. Replicated honeycomb packed polymer microlenses as substitute for facet lenses in a natural compound eye was microfabricated with a photoresist melting process for microlens templates and a soft lithographic process for polymer replication. The microtemplate of photoresist microlens arrays (F/1 ˜ F/3, DL = 20 ˜ 50 mum) with low Fresnel number (NF < 10) and high packing density was replicated with different polymers such as UV curable epoxy resin, polydimethylsiloxane elastomer, and a negative tone photoresist. Related to ommatidial optics, the diffraction of a low Fresnel number microlens, the light guiding of a waveguide, and the angular acceptance function of a microlens-waveguide system were theoretically studied with numerical analysis. First, as a prototype microfabricated microlens-waveguide system ( DL = 300 mum), a small angular acceptance (rho A = 1.5°) comparable to that of natural ommatidia was experimentally achieved and compared with the numerical analysis. The system is based on self-written waveguides in a photosensitive polymer resin and replicated elastomer microlens arrays. However, due to the technical difficulties in handling the elastomer membrane with microlenses, it is limited in scaling down to the physical dimensions of natural ommatidium. Second, as an advanced development, self-aligned microlens-waveguide systems comparable to the physical dimensions of natural ommatidia have been developed and integrated in a photosensitive resin. The individual microlens-waveguide systems of about 8,370 were spherically arranged along the circumference of a polymer dome of 2.5 mm in diameter and each points in different directions. The spherical configuration was realized using a replication process of reconfigurable microtemplates, i.e. the polymer replication using the deformed elastomer membrane with microlens patterns under small pressure (5 kPa ˜ 20 kPa). The characterizations of the small scale microlenses (F/1.8 ˜ F/2.9, DL = 25 mum) and waveguides were also carried out with a modified reflection/transmission confocal microscope. The comparative discussion between natural and artificial compound eyes is described and several future directions based on this work are also proposed.

Jeong, Ki-Hun

2005-11-01

229

Common Compound Library  

NSDL National Science Digital Library

This database, part of a college-level chemistry course, provides information on hundreds of compounds, elements, and substances encountered in introductory chemistry courses and in everyday life. The informaion includes chemical synonyms, molecular weights, structures, equilibrium constants, thermodynamic properties, and common uses, with properties presented in a variety of common units. Structure information includes flat structural formulas, ball and stick models, electron density/electric potential maps, and Chime "live" structures that can be rotated and queried for bond lengths, bond angles, and torsion angles. The site also includes links to the course website, a glossary, a frequently-asked-questions feature, information on sources used in constructing the database, and many other resources.

Frederick A. Senese

230

Microoptical telescope compound eye  

NASA Astrophysics Data System (ADS)

A new optical concept for compact digital image acquisition devices with large field of view is developed and proofed experimentally. Archetypes for the imaging system are compound eyes of small insects and the Gabor Superlens. A paraxial 3x3 matrix formalism is used to describe the telescope arrangement of three microlens arrays with different pitch to find first order parameters of the imaging system. A 2mm thin imaging system with 21x3 channels, 70ºx10º field of view and 4.5mm x 0.5mm image size is optimized and analyzed using sequential and non sequential raytracing and fabricated by microoptics technology. Anamorphic lenses, where the parameters are a function of the considered optical channel, are used to achieve a homogeneous optical performance over the whole field of view. Captured images are presented and compared to simulation results.

Duparré, Jacques W.; Schreiber, Peter; Matthes, André; Pshenay–Severin, Ekaterina; Bräuer, Andreas; Tünnermann, Andreas; Völkel, Reinhard; Eisner, Martin; Scharf, Toralf

2005-02-01

231

Microoptical telescope compound eye.  

PubMed

A new optical concept for compact digital image acquisition devices with large field of view is developed and proofed experimentally. Archetypes for the imaging system are compound eyes of small insects and the Gabor-Superlens. A paraxial 3x3 matrix formalism is used to describe the telescope arrangement of three microlens arrays with different pitch to find first order parameters of the imaging system. A 2mm thin imaging system with 21x3 channels, 70 masculinex10 masculine field of view and 4.5mm x 0.5mm image size is optimized and analyzed using sequential and non-sequential raytracing and fabricated by microoptics technology. Anamorphic lenses, where the parameters are a function of the considered optical channel, are used to achieve a homogeneous optical performance over the whole field of view. Captured images are presented and compared to simulation results. PMID:19494951

Duparré, Jacques; Schreiber, Peter; Matthes, André; Pshenay-Severin, Ekaterina; Bräuer, Andreas; Tünnermann, Andreas; Völkel, Reinhard; Eisner, Martin; Scharf, Toralf

2005-02-01

232

Method of preparing metallocene compounds  

DOEpatents

This invention describes a novel method of preparing metallocene compounds. The invention is based on synthesis of novel bis cyclopentadienides that, under appropriate conditions, will either encapsulate a transition metal to produce a metallocene such as ferrocene, or ferrocene derivative, or will yield a polymeric metallocene. Compounds produced by this process are useful as catalysts in propulsion systems, or as anti-knock compounds in gasolines.

Rosenblum, Myron (Lexington, MA); Matchett, Stephen A. (Lisle, IL)

1992-01-01

233

Antimalarial compounds from Schefflera umbellifera  

Microsoft Academic Search

The organic extract of the leaves of Schefflera umbellifera exhibited good antimalarial activity when tested against the chloroquine-susceptible strain (D10). Bioassay-guided fractionation of the dichloromethane fraction of the dichloromethane\\/methanol extract yielded an active compound, betulin, which exhibited good antiplasmodial activity with an IC50 value of 3.2µg\\/ml. The reference compound, chloroquine gave an IC50 value of 27.2ng\\/ml. Two other compounds were

X. S. Mthembu; F. R. Van Heerden; G. Fouché

2010-01-01

234

Biomedical Compounds from Marine organisms  

PubMed Central

The Ocean, which is called the ‘mother of origin of life’, is also the source of structurally unique natural products that are mainly accumulated in living organisms. Several of these compounds show pharmacological activities and are helpful for the invention and discovery of bioactive compounds, primarily for deadly diseases like cancer, acquired immuno-deficiency syndrome (AIDS), arthritis, etc., while other compounds have been developed as analgesics or to treat inflammation, etc. The life-saving drugs are mainly found abundantly in microorganisms, algae and invertebrates, while they are scarce in vertebrates. Modern technologies have opened vast areas of research for the extraction of biomedical compounds from oceans and seas.

Jha, Rajeev Kumar; Zi-rong, Xu

2004-01-01

235

Organic Compounds in Carbonaceous Meteorites  

NASA Technical Reports Server (NTRS)

Carbonaceous meteorites are relatively enriched in soluble organic compounds. To date, these compounds provide the only record available to study a range of organic chemical processes in the early Solar System chemistry. The Murchison meteorite is the best-characterized carbonaceous meteorite with respect to organic chemistry. The study of its organic compounds has related principally to aqueous meteorite parent body chemistry and compounds of potential importance for the origin of life. Among the classes of organic compounds found in Murchison are amino acids, amides, carboxylic acids, hydroxy acids, sulfonic acids, phosphonic acids, purines and pyrimidines (Table 1). Compounds such as these were quite likely delivered to the early Earth in asteroids and comets. Until now, polyhydroxylated compounds (polyols), including sugars (polyhydroxy aldehydes or ketones), sugar alcohols, sugar acids, etc., had not been identified in Murchison. Ribose and deoxyribose, five-carbon sugars, are central to the role of contemporary nucleic acids, DNA and RNA. Glycerol, a three-carbon sugar alcohol, is a constituent of all known biological membranes. Due to the relative lability of sugars, some researchers have questioned the lifetime of sugars under the presumed conditions on the early Earth and postulated other (more stable) compounds as constituents of the first replicating molecules. The identification of potential sources and/or formation mechanisms of pre-biotic polyols would add to the understanding of what organic compounds were available, and for what length of time, on the ancient Earth.

Cooper, Grorge

2001-01-01

236

Antimicrobial Compounds in Tears  

PubMed Central

The tear film coats the cornea and conjunctiva and serves several important functions. It provides lubrication, prevents drying of the ocular surface epithelia, helps provide a smooth surface for refracting light, supplies oxygen and is an important component of the innate defense system of the eye providing protection against a range of potential pathogens. This review describes both classic antimicrobial compounds found in tears such as lysozyme and some more recently identified such as members of the cationic antimicrobial peptide family and surfactant protein-D as well as potential new candidate molecules that may contribute to antimicrobial protection. As is readily evident from the literature review herein, tears, like all mucosal fluids, contain a plethora of molecules with known antimicrobial effects. That all of these are active in vivo is debatable as many are present in low concentrations, may be influenced by other tear components such as the ionic environment, and antimicrobial action may be only one of several activities ascribed to the molecule. However, there are many studies showing synergistic/additive interactions between several of the tear antimicrobials and it is highly likely that cooperativity between molecules is the primary way tears are able to afford significant antimicrobial protection to the ocular surface in vivo. In addition to effects on pathogen growth and survival some tear components prevent epithelial cell invasion and promote the epithelial expression of innate defense molecules. Given the protective role of tears a number of scenarios can be envisaged that may affect the amount and/or activity of tear antimicrobials and hence compromise tear immunity. Two such situations, dry eye disease and contact lens wear, are discussed here. PMID:23880529

McDermott, Alison M.

2013-01-01

237

Bioactive compounds produced by cyanobacteria  

Microsoft Academic Search

Cyanobacteria produce a large number of compounds with varying bioactivities. Prominent among these are toxins: hepatotoxins such as microcystins and nodularins and neurotoxins such as anatoxins and saxitoxins. Cytotoxicity to tumor cells has been demonstrated for other cyanobacterial products, including 9-deazaadenosine, dolastatin 13 and analogs. A number of compounds in cyanobacteria are inhibitors of proteases — micropeptins, cyanopeptolins, oscillapeptin, microviridin,

M Namikoshi; KL Rinehart

1996-01-01

238

ATMOSPHERIC FREONS AND HALOGENATED COMPOUNDS  

EPA Science Inventory

Ambient levels of atmospheric Freons, halogenated hydrocarbons, and SF6 were measured at various locations in the U.S.A. Compounds such as CCl3F, CCl2F2, CH3-CCl3, and CCl4 were ubiquitious and generally measured at sub ppb levels. Tropospherically reactive compounds such as C2Cl...

239

Morphological Dynamics in Compound Processing  

ERIC Educational Resources Information Center

This paper explores the time-course of morphological processing of trimorphemic Finnish compounds. We find evidence for the parallel access to full-forms and morphological constituents diagnosed by the early effects of compound frequency, as well as early effects of left constituent frequency and family size. We also observe an interaction between…

Kuperman, Victor; Bertram, Raymond; Baayen, R. Harald

2008-01-01

240

Bilingual Reading of Compound Words  

ERIC Educational Resources Information Center

The present study investigated whether bilingual readers activate constituents of compound words in one language while processing compound words in the other language via decomposition. Two experiments using a lexical decision task were conducted with adult Korean-English bilingual readers. In Experiment 1, the lexical decision of real English…

Ko, In Yeong; Wang, Min; Kim, Say Young

2011-01-01

241

Video: Focusing a Compound Microscope  

NSDL National Science Digital Library

This video from CUNY Kingsborough Community College describes how to focus a compound microscope. The brief clip, available for viewing on YouTube, would be most useful for students with a basic understanding of the parts of a compound microscope and how to use it. Running time for the video is 0:55.

2013-07-01

242

Micro-machined calorimetric biosensors  

DOEpatents

A method and apparatus are provided for detecting and monitoring micro-volumetric enthalpic changes caused by molecular reactions. Micro-machining techniques are used to create very small thermally isolated masses incorporating temperature-sensitive circuitry. The thermally isolated masses are provided with a molecular layer or coating, and the temperature-sensitive circuitry provides an indication when the molecules of the coating are involved in an enthalpic reaction. The thermally isolated masses may be provided singly or in arrays and, in the latter case, the molecular coatings may differ to provide qualitative and/or quantitative assays of a substance.

Doktycz, Mitchel J. (Knoxville, TN); Britton, Jr., Charles L. (Alcoa, TN); Smith, Stephen F. (Loudon, TN); Oden, Patrick I. (Plano, TX); Bryan, William L. (Knoxville, TN); Moore, James A. (Powell, TN); Thundat, Thomas G. (Knoxville, TN); Warmack, Robert J. (Knoxville, TN)

2002-01-01

243

Calorimetric study of cationic photopolymerization  

NASA Astrophysics Data System (ADS)

The photopolymerization of penta-erythritol tetra-glycidyl ether (initiator Degacure KI-85) was studied by a du Pont 910 type DSC. From our experimental results the following conclusions can be drawn: (1) During the cationic polymerization reaction the lifetime of the initiating centers are long compared to the lifetime of free radicals in case of radical polymerization. (2) The rate of deactivation of the initiating centers increases with increasing temperature.

Czajlik, I.; Hedvig, P.; Ille, A.; Dobó, J.

1996-03-01

244

Devices for collecting chemical compounds  

DOEpatents

A device for sampling chemical compounds from fixed surfaces and related methods are disclosed. The device may include a vacuum source, a chamber and a sorbent material. The device may utilize vacuum extraction to volatilize the chemical compounds from a fixed surface so that they may be sorbed by the sorbent material. The sorbent material may then be analyzed using conventional thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS) instrumentation to determine presence of the chemical compounds. The methods may include detecting release and presence of one or more chemical compounds and determining the efficacy of decontamination. The device may be useful in collection and analysis of a variety of chemical compounds, such as residual chemical warfare agents, chemical attribution signatures and toxic industrial chemicals.

Scott, Jill R; Groenewold, Gary S

2013-12-24

245

Paired-angle multiplicative compounding.  

PubMed

Ultrasound compounding is a method of combining multiple images from different angles in order to create a single image with improved resolution and reduced angular-dependent artifactual detail. Compounding methods traditionally calculate each pixel in the compound image as a simple functional relationship between pixel elements in the component image set. In order to achieve an even better resolution and further reduce angular-dependent artifacts, this paper investigates a new type of compounding we call paired angle multiplicative compounding (PAMC), in which compound images are produced by a summation of multiplied pairs of component images acquired at different angles. A PAMC image of a breast phantom demonstrates improved delineation ofmicrocalcifications in comparison to the mean operation. Images of the forearm are used to investigate larger angles of paired multiplication, the best improving contrast ratio (28%) and signal to noise ratio (24%) when compared to the mean method. The PAMC method is found to be similar to the MEM and median compounding operations, the largest difference being that it is better preserving contributions from normal incidence but at the expense of needing a larger angular range. PMID:18939612

Macione, James; Yang, Zhi; Fox, Martin

2008-04-01

246

Membrane rejection of nitrogen compounds  

NASA Technical Reports Server (NTRS)

Rejection characteristics of nitrogen compounds were examined for reverse osmosis, nanofiltration, and low-pressure reverse osmosis membranes. The rejection of nitrogen compounds is explained by integrating experimental results with calculations using the extended Nernst-Planck model coupled with a steric hindrance model. The molecular weight and chemical structure of nitrogen compounds appear to be less important in determining rejection than electrostatic properties. The rejection is greatest when the Donnan potential exceeds 0.05 V or when the ratio of the solute radius to the pore radius is greater than 0.8. The transport of solute in the pore is dominated by diffusion, although convective transport is significant for organic nitrogen compounds. Electromigration contributes negligibly to the overall solute transport in the membrane. Urea, a small organic compound, has lower rejection than ionic compounds such as ammonium, nitrate, and nitrite, indicating the critical role of electrostatic interaction in rejection. This suggests that better treatment efficiency for organic nitrogen compounds can be obtained after ammonification of urea.

Lee, S.; Lueptow, R. M.

2001-01-01

247

Routes to Novel Azo compounds   

E-print Network

Routes to novel heterocyclic azo compounds and components of use as potential inkjet dyes were investigated. A new route to fluorenones from biphenyl acid chlorides using FVP (Flash Vacuum Pyrolysis) has been discovered. ...

Iannarelli, Paul M.

248

Photochemical dimerization of organic compounds  

DOEpatents

At least one of selectivity and reaction rate of photosensitized vapor phase dimerizations, including dehydrodimerizations, hydrodimerizations and cross-dimerizations of saturated and unsaturated organic compounds is improved by conducting the dimerization in the presence of hydrogen or nitrous oxide.

Crabtree, Robert H. (Bethany, CT); Brown, Stephen H. (Princeton, NJ); Muedas, Cesar A. (New Haven, CT); Ferguson, Richard R. (Branford, CT)

1992-01-01

249

Crystallographic properties of fertilizer compounds  

SciTech Connect

This bulletin is a compilation of crystallographic data collected at NFERC on 450 fertilizer-related compounds. In TVA's fertilizer R and D program, petrographic examination, XRD, and infrared spectroscopy are combined with conventional chemical analysis methods in identifying the individual compounds that occur in fertilizer materials. This handbook brings together the results of these characterization studies and supplemental crystallographic data from the literature. It is in one-compound-per-page, loose-leaf format, ordered alphabetically by IUPAC name. Indexes provided include IUPAC name, formula, group, alternate formula, synonyms, x-ray data, optical data. Tables are given for solids, compounds in commercial MAP and DAP, and matrix materials in phosphate rock.

Frazier, A.W.; Dillard, E.F.; Thrasher, R.D.; Waerstad, K.R.; Hunter, S.R.; Kohler, J.J.; Scheib, R.M.

1991-02-01

250

Compound Independent and Dependent Events  

NSDL National Science Digital Library

Compare the theoretical and experimental probability of a compound independent event by drawing colored marbles from a bag. Record the results of successive draws with or without replacement of marbles to calculate the experimental probability.

2007-12-12

251

The Magic of Compound Interest  

NSDL National Science Digital Library

The most powerful force in the universe is compound interest - Albert Einstein - Compound interest is the underlying concept that allows your money to grow on its own and that\\'s what leads to a lucrative future. It\\'s the interest you earn off of your original investment plus the interest you\\'ve already accrued. It\\'s interest on interest. And what it can do is amazing. Compound interest\\'s a cyclical monster that feeds itself and keeps growing at an exponential rate. And the best part about compound interest is that young people have the advantage. Young, first-time investors have an upper hand on older, wiser, Wall Street investors and stock market gurus because young people have ...

Mr. Gordon

2006-10-19

252

Detection of chlorinated aromatic compounds  

DOEpatents

A method for making a composition for measuring the concentration of chloated aromatic compounds in aqueous fluids, and an optical probe for use with the method. The composition comprises a hydrophobic polymer matrix, preferably polyamide, with a fluorescent indicator uniformly dispersed therein. The indicator fluoresces in the presence of the chlorinated aromatic compounds with an intensity dependent on the concentration of these compounds in the fluid of interest, such as 8-amino-2-naphthalene sulfonate. The probe includes a hollow cylindrical housing that contains the composition in its distal end. The probe admits an aqueous fluid to the probe interior for exposure to the composition. An optical fiber transmits excitation light from a remote source to the composition while the indicator reacts with chlorinated aromatic compounds present in the fluid. The resulting fluorescence light signal is reflected to a second optical fiber that transmits the light to a spectrophotometer for analysis.

Ekechukwu, Amy A. (Augusta, GA)

1996-01-01

253

Detection of chlorinated aromatic compounds  

DOEpatents

A method for making a composition for measuring the concentration of chlorinated aromatic compounds in aqueous fluids, and an optical probe for use with the method are disclosed. The composition comprises a hydrophobic polymer matrix, preferably polyamide, with a fluorescent indicator uniformly dispersed therein. The indicator fluoresces in the presence of the chlorinated aromatic compounds with an intensity dependent on the concentration of these compounds in the fluid of interest, such as 8-amino-2-naphthalene sulfonate. The probe includes a hollow cylindrical housing that contains the composition in its distal end. The probe admits an aqueous fluid to the probe interior for exposure to the composition. An optical fiber transmits excitation light from a remote source to the composition while the indicator reacts with chlorinated aromatic compounds present in the fluid. The resulting fluorescence light signal is reflected to a second optical fiber that transmits the light to a spectrophotometer for analysis. 5 figs.

Ekechukwu, A.A.

1996-02-06

254

Nitric Oxide-Releasing Compounds  

NSDL National Science Digital Library

The five WebWare Molecules for December derive from the article Nitrogen-Based Diazeniumdiolates: Versatile Nitric Oxide-Releasing Compounds for Biomedical Research and Potential Clinical Applications by Joseph E. Saavedra and Larry K. Keefer.

255

Special Risks of Pharmacy Compounding  

MedlinePLUS

... had devastating repercussions. The fall 2012 outbreak of fungal meningitis has been linked to an injectable steroid medication ... 2012 - For More Information Questions and Answers on Fungal Meningitis Outbreak Drug Safety Communications Compounding - Page Last Updated: ...

256

Biologically Inspired Artificial Compound Eyes  

NASA Astrophysics Data System (ADS)

This work presents the fabrication of biologically inspired artificial compound eyes. The artificial ommatidium, like that of an insect's compound eyes, consists of a refractive polymer microlens, a light-guiding polymer cone, and a self-aligned waveguide to collect light with a small angular acceptance. The ommatidia are omnidirectionally arranged along a hemispherical polymer dome such that they provide a wide field of view similar to that of a natural compound eye. The spherical configuration of the microlenses is accomplished by reconfigurable microtemplating, that is, polymer replication using the deformed elastomer membrane with microlens patterns. The formation of polymer waveguides self-aligned with microlenses is also realized by a self-writing process in a photosensitive polymer resin. The angular acceptance is directly measured by three-dimensional optical sectioning with a confocal microscope, and the detailed optical characteristics are studied in comparison with a natural compound eye.

Jeong, Ki-Hun; Kim, Jaeyoun; Lee, Luke P.

2006-04-01

257

Aza compounds as anion receptors  

SciTech Connect

A family of aza-ether based compounds including linear, multi-branched and aza-crown ethers is provided. When added to non-aqueous battery electrolytes, the family of aza-ether based compounds acts as neutral receptors to complex the anion moiety of the electrolyte salt thereby increasing the conductivity and the transference number of Li.sup.+ ion in alkali metal batteries.

Lee, Hung Sui (East Setauket, NY); Yang, Xiao-Qing (Port Jefferson Station, NY); McBreen, James (Bellport, NY)

1998-01-06

258

Aza compounds as anion receptors  

DOEpatents

A family of aza-ether based compounds including linear, multi-branched and aza-crown ethers is provided. When added to non-aqueous battery electrolytes, the family of aza-ether based compounds acts as neutral receptors to complex the anion moiety of the electrolyte salt thereby increasing the conductivity and the transference number of Li{sup +} ion in alkali metal batteries. 3 figs.

Lee, H.S.; Yang, X.Q.; McBreen, J.

1998-01-06

259

Volatile Organic Compounds in Uremia  

PubMed Central

Background Although “uremic fetor” has long been felt to be diagnostic of renal failure, the compounds exhaled in uremia remain largely unknown so far. The present work investigates whether breath analysis by ion mobility spectrometry can be used for the identification of volatile organic compounds retained in uremia. Methods Breath analysis was performed in 28 adults with an eGFR ?60 ml/min per 1.73 m2, 26 adults with chronic renal failure corresponding to an eGFR of 10–59 ml/min per 1.73 m2, and 28 adults with end-stage renal disease (ESRD) before and after a hemodialysis session. Breath analysis was performed by ion mobility spectrometryafter gas-chromatographic preseparation. Identification of the compounds of interest was performed by thermal desorption gas chromatography/mass spectrometry. Results Breath analyses revealed significant differences in the spectra of patients with and without renal failure. Thirteen compounds were chosen for further evaluation. Some compounds including hydroxyacetone, 3-hydroxy-2-butanone and ammonia accumulated with decreasing renal function and were eliminated by dialysis. The concentrations of these compounds allowed a significant differentiation between healthy, chronic renal failure with an eGFR of 10–59 ml/min, and ESRD (p<0.05 each). Other compounds including 4-heptanal, 4-heptanone, and 2-heptanone preferentially or exclusively occurred in patients undergoing hemodialysis. Conclusion Impairment of renal function induces a characteristic fingerprint of volatile compounds in the breath. The technique of ion mobility spectrometry can be used for the identification of lipophilic uremic retention molecules. PMID:23049998

Seifert, Luzia; Slodzinski, Rafael; Jankowski, Joachim; Zidek, Walter; Westhoff, Timm H.

2012-01-01

260

Miniature curved artificial compound eyes  

PubMed Central

In most animal species, vision is mediated by compound eyes, which offer lower resolution than vertebrate single-lens eyes, but significantly larger fields of view with negligible distortion and spherical aberration, as well as high temporal resolution in a tiny package. Compound eyes are ideally suited for fast panoramic motion perception. Engineering a miniature artificial compound eye is challenging because it requires accurate alignment of photoreceptive and optical components on a curved surface. Here, we describe a unique design method for biomimetic compound eyes featuring a panoramic, undistorted field of view in a very thin package. The design consists of three planar layers of separately produced arrays, namely, a microlens array, a neuromorphic photodetector array, and a flexible printed circuit board that are stacked, cut, and curved to produce a mechanically flexible imager. Following this method, we have prototyped and characterized an artificial compound eye bearing a hemispherical field of view with embedded and programmable low-power signal processing, high temporal resolution, and local adaptation to illumination. The prototyped artificial compound eye possesses several characteristics similar to the eye of the fruit fly Drosophila and other arthropod species. This design method opens up additional vistas for a broad range of applications in which wide field motion detection is at a premium, such as collision-free navigation of terrestrial and aerospace vehicles, and for the experimental testing of insect vision theories. PMID:23690574

Floreano, Dario; Pericet-Camara, Ramon; Viollet, Stéphane; Ruffier, Franck; Brückner, Andreas; Leitel, Robert; Buss, Wolfgang; Menouni, Mohsine; Expert, Fabien; Juston, Raphaël; Dobrzynski, Michal Karol; L’Eplattenier, Geraud; Recktenwald, Fabian; Mallot, Hanspeter A.; Franceschini, Nicolas

2013-01-01

261

Miniature curved artificial compound eyes.  

PubMed

In most animal species, vision is mediated by compound eyes, which offer lower resolution than vertebrate single-lens eyes, but significantly larger fields of view with negligible distortion and spherical aberration, as well as high temporal resolution in a tiny package. Compound eyes are ideally suited for fast panoramic motion perception. Engineering a miniature artificial compound eye is challenging because it requires accurate alignment of photoreceptive and optical components on a curved surface. Here, we describe a unique design method for biomimetic compound eyes featuring a panoramic, undistorted field of view in a very thin package. The design consists of three planar layers of separately produced arrays, namely, a microlens array, a neuromorphic photodetector array, and a flexible printed circuit board that are stacked, cut, and curved to produce a mechanically flexible imager. Following this method, we have prototyped and characterized an artificial compound eye bearing a hemispherical field of view with embedded and programmable low-power signal processing, high temporal resolution, and local adaptation to illumination. The prototyped artificial compound eye possesses several characteristics similar to the eye of the fruit fly Drosophila and other arthropod species. This design method opens up additional vistas for a broad range of applications in which wide field motion detection is at a premium, such as collision-free navigation of terrestrial and aerospace vehicles, and for the experimental testing of insect vision theories. PMID:23690574

Floreano, Dario; Pericet-Camara, Ramon; Viollet, Stéphane; Ruffier, Franck; Brückner, Andreas; Leitel, Robert; Buss, Wolfgang; Menouni, Mohsine; Expert, Fabien; Juston, Raphaël; Dobrzynski, Michal Karol; L'Eplattenier, Geraud; Recktenwald, Fabian; Mallot, Hanspeter A; Franceschini, Nicolas

2013-06-01

262

Magnetic and thermodynamic properties of NdT{sub 2}Ge{sub 2} (T=Pd, Ag) compounds  

SciTech Connect

Physical properties of NdPd{sub 2}Ge{sub 2} and NdAg{sub 2}Ge{sub 2}, crystallizing with the tetragonal ThCr{sub 2}Si{sub 2}-type crystal structure, were investigated by means of magnetic, calorimetric, electrical transport as well as by neutron diffraction measurements. The specific heat studies and neutron diffraction measurements were performed down to 0.30 K and 0.47 K, respectively. Both compounds exhibit antiferromagnetic ordering below T{sub N} equal to 1.5 K for NdPd{sub 2}Ge{sub 2} and 1.8 K for NdAg{sub 2}Ge{sub 2}. Neutron diffraction data for the latter germanide indicate antiferromagnetic collinear structure described by the propagation vector k=(0.5, 0, 0.5). The Nd magnetic moments equal to 2.24(5) mu{sub B} at 0.47 K are aligned along the a-axis and have the +- sequence within the crystal unit cell. For NdPd{sub 2}Ge{sub 2} only very small Bragg peaks of magnetic origin were observed in the neutron diffraction patterns measured below T{sub N}, thus hampering determination of the magnetic structure. Both compounds exhibit metallic-like electrical conduction. From the specific heat data the crystal electric field (CEF) levels schemes were determined. Difference between the overall CEF splitting in the two compounds is correlated with their structural parameters. - Graphical abstract: Low-temperature specific heat of NdAg{sub 2}Ge{sub 2} under external magnetic fields. The lambda-like anomaly originates from onset of magnetic ordering below 1.80 K. Shifting the anomaly position towards the lower temperatures, when raising the magnetic field, hints at antiferromagnetic behaviors.

Gondek, L., E-mail: lgondek@agh.edu.p [Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Mickiewicza 30, 30-059 Krakow (Poland); Penc, B. [M. Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow (Poland); Kaczorowski, D. [W. Trzebiatowski Institute of Low Temperature and Structural Research, Polish Academy of Sciences, PO Box 1410, 50-950 WrocLaw (Poland); Baran, S. [M. Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow (Poland); Hoser, A.; Gerischer, S. [BENSC, Helmholtz-Zentrum Berlin, Glienicker Str. 100, D-14 109 Berlin (Germany); SzytuLa, A. [M. Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow (Poland)

2010-04-15

263

Extraterrestrial Organic Compounds in Meteorites  

NASA Technical Reports Server (NTRS)

Many organic compounds or their precursors found in meteorites originated in the interstellar or circumstellar medium and were later incorporated into planetesimals during the formation of the solar system. There they either survived intact or underwent further processing to synthesize secondary products on the meteorite parent body. The most distinct feature of CI and CM carbonaceous chondrites, two types of stony meteorites, is their high carbon content (up to 3% of weight), either in the form of carbonates or of organic compounds. The bulk of the organic carbon consists of an insoluble macromolecular material with a complex structure. Also present is a soluble organic fraction, which has been analyzed by several separation and analytical procedures. Low detection limits can be achieved by derivatization of the organic molecules with reagents that allow for analysis by gas chromatography/mass spectroscopy and high performance liquid chromatography. The CM meteorite Murchison has been found to contain more than 70 extraterrestrial amino acids and several other classes of compounds including carboxylic acids, hydroxy carboxylic acids, sulphonic and phosphonic acids, aliphatic, aromatic and polar hydrocarbons, fullerenes, heterocycles as well as carbonyl compounds, alcohols, amines and amides. The organic matter was found to be enriched in deuterium, and distinct organic compounds show isotopic enrichments of carbon and nitrogen relative to terrestrial matter.

Botta, Oliver; Bada, Jeffrey L.; Meyer, Michael (Technical Monitor)

2003-01-01

264

Cytotoxic Compounds from Brucea mollis  

PubMed Central

Ten compounds, including soulameanone (1), isobruceine B (2), 9-methoxy-canthin-6-one (3), bruceolline F (4), niloticine (5), octatriacontan-1-ol (6), bombiprenone (7), ?-tocopherol (8), inosine (9), and apigenin 7-O-?-D-glucopyranoside (10), were isolated from the leaves, stems, and roots of Brucea mollis Wall. ex Kurz. Their structures were determined using one-and two-dimensional NMR spectroscopy and mass spectrometry. All compounds were evaluated for their cytotoxic activity against KB (human carcinoma of the mouth), LU-1 (human lung adenocarcinoma), LNCaP (human prostate adeno-carcinoma), and HL-60 (human promyelocytic leukemia) cancer cell lines. Compound 2 showed significant cytotoxic activity against KB, LU-1, LNCaP, and HL-60 cancer cells with IC50 values of 0.39, 0.40, 0.34, and 0.23 ?g/mL, respectively. In addition, compounds 3 and 5 showed significant cytotoxic activity against KB, LU-1, LNCaP, and HL-60 cancer cells with IC50 values around 1–4 ?g/mL. Compounds 9-methoxycanthin-6-one (3) and niloticine (5) have been discovered for the first time from the Brucea genus. PMID:24106661

Tung, Mai Hung Thanh; ?uc, Ho Viet; Huong, Tran Thu; Duong, Nguyen Thanh; Phuong, Do Thi; Thao, Do Thi; Tai, Bui Huu; Kim, Young Ho; Bach, Tran The; Cuong, Nguyen Manh

2013-01-01

265

Associative asymmetry of compound words.  

PubMed

Early verbal-memory researchers assumed participants represent memory of a pair of unrelated items with 2 independent, separately modifiable, directional associations. However, memory for pairs of unrelated words (A-B) exhibits associative symmetry: a near-perfect correlation between accuracy on forward (A ??) and backward (?? B) cued recall. This was viewed as arguing against the independent-associations hypothesis and in favor of the hypothesis that associations are remembered as holistic units. Here we test the Holistic Representation hypothesis further by examining cued recall of compound words. If we suppose preexisting words are more unitized than novel associations, the Holistic Representation hypothesis predicts compound words (e.g., ROSE BUD) will have a higher forward-backward correlation than novel compounds (e.g., BRIEF TAX). We report the opposite finding: Compound words, as well as noncompound words, exhibited less associative symmetry than novel compounds. This challenges the Holistic Representation account of associative symmetry. Moreover, preexperimental associates (positional family size) influenced associative symmetry-but asymmetrically: Increasing family size of the last constituent increasing decoupled forward and backward recall, but family size of the 1st constituent had no such effect. In short, highly practiced, meaningful associations exhibit associative asymmetry, suggesting associative symmetry is not diagnostic of holistic representations but, rather, is a characteristic of ad hoc associations. With additional learning, symmetric associations may be replaced by directional, independently modifiable associations as verbal associations become embedded within a rich knowledge structure. PMID:24773284

Caplan, Jeremy B; Boulton, Kathy L; Gagné, Christina L

2014-07-01

266

Antitumor Compounds from Marine Actinomycetes  

PubMed Central

Chemotherapy is one of the main treatments used to combat cancer. A great number of antitumor compounds are natural products or their derivatives, mainly produced by microorganisms. In particular, actinomycetes are the producers of a large number of natural products with different biological activities, including antitumor properties. These antitumor compounds belong to several structural classes such as anthracyclines, enediynes, indolocarbazoles, isoprenoides, macrolides, non-ribosomal peptides and others, and they exert antitumor activity by inducing apoptosis through DNA cleavage mediated by topoisomerase I or II inhibition, mitochondria permeabilization, inhibition of key enzymes involved in signal transduction like proteases, or cellular metabolism and in some cases by inhibiting tumor-induced angiogenesis. Marine organisms have attracted special attention in the last years for their ability to produce interesting pharmacological lead compounds. PMID:19597582

Olano, Carlos; Méndez, Carmen; Salas, José A.

2009-01-01

267

Gallium-containing anticancer compounds  

PubMed Central

There is an ever pressing need to develop new drugs for the treatment of cancer. Gallium nitrate, a group IIIa metal salt, inhibits the proliferation of tumor cells in vitro and in vivo and has shown activity against non-Hodgkin’s lymphoma and bladder cancer in clinical trials. Gallium can function as an iron mimetic and perturb iron-dependent proliferation and other iron-related processes in tumor cells. Gallium nitrate lacks cross resistance with conventional chemotherapeutic drugs and is not myelosuppressive; it can be used when other drugs have failed or when the blood count is low. Given the therapeutic potential of gallium, newer generations of gallium compounds are now in various phases of preclinical and clinical development. These compounds hold the promise of greater anti-tumor activity against a broader spectrum of cancers. The development of gallium compounds for cancer treatment and their mechanisms of action will be discussed. PMID:22800370

Chitambar, Christopher R

2013-01-01

268

Hydrophobic compounds reshape membrane domains.  

PubMed

Cell membranes have a complex lateral organization featuring domains with distinct composition, also known as rafts, which play an essential role in cellular processes such as signal transduction and protein trafficking. In vivo, perturbations of membrane domains (e.g., by drugs or lipophilic compounds) have major effects on the activity of raft-associated proteins and on signaling pathways, but they are difficult to characterize because of the small size of the domains, typically below optical resolution. Model membranes, instead, can show macroscopic phase separation between liquid-ordered and liquid-disordered domains, and they are often used to investigate the driving forces of membrane lateral organization. Studies in model membranes have shown that some lipophilic compounds perturb membrane domains, but it is not clear which chemical and physical properties determine domain perturbation. The mechanisms of domain stabilization and destabilization are also unknown. Here we describe the effect of six simple hydrophobic compounds on the lateral organization of phase-separated model membranes consisting of saturated and unsaturated phospholipids and cholesterol. Using molecular simulations, we identify two groups of molecules with distinct behavior: aliphatic compounds promote lipid mixing by distributing at the interface between liquid-ordered and liquid-disordered domains; aromatic compounds, instead, stabilize phase separation by partitioning into liquid-disordered domains and excluding cholesterol from the disordered domains. We predict that relatively small concentrations of hydrophobic species can have a broad impact on domain stability in model systems, which suggests possible mechanisms of action for hydrophobic compounds in vivo. PMID:25299598

Barnoud, Jonathan; Rossi, Giulia; Marrink, Siewert J; Monticelli, Luca

2014-10-01

269

Hydrophobic Compounds Reshape Membrane Domains  

PubMed Central

Cell membranes have a complex lateral organization featuring domains with distinct composition, also known as rafts, which play an essential role in cellular processes such as signal transduction and protein trafficking. In vivo, perturbations of membrane domains (e.g., by drugs or lipophilic compounds) have major effects on the activity of raft-associated proteins and on signaling pathways, but they are difficult to characterize because of the small size of the domains, typically below optical resolution. Model membranes, instead, can show macroscopic phase separation between liquid-ordered and liquid-disordered domains, and they are often used to investigate the driving forces of membrane lateral organization. Studies in model membranes have shown that some lipophilic compounds perturb membrane domains, but it is not clear which chemical and physical properties determine domain perturbation. The mechanisms of domain stabilization and destabilization are also unknown. Here we describe the effect of six simple hydrophobic compounds on the lateral organization of phase-separated model membranes consisting of saturated and unsaturated phospholipids and cholesterol. Using molecular simulations, we identify two groups of molecules with distinct behavior: aliphatic compounds promote lipid mixing by distributing at the interface between liquid-ordered and liquid-disordered domains; aromatic compounds, instead, stabilize phase separation by partitioning into liquid-disordered domains and excluding cholesterol from the disordered domains. We predict that relatively small concentrations of hydrophobic species can have a broad impact on domain stability in model systems, which suggests possible mechanisms of action for hydrophobic compounds in vivo. PMID:25299598

Barnoud, Jonathan; Rossi, Giulia; Marrink, Siewert J.; Monticelli, Luca

2014-01-01

270

Basics of compounding with tars.  

PubMed

Tar has been used throughout history for numerous purposes; from sealing the hulls of ships to sealing roofs of dwellings and even for medical purposes. Produced by destructive distillation, commonly used tars are prepared from coal and wood. Coal tar, juniper tar, and pine tar are used for various medical purposes as described in the article. Also presented are the various characteristics and uses of each tar, along with commercial products and numerous compounding formulas. Techniques used to compound with tars are also presented. PMID:24459787

Allen, Loyd V

2013-01-01

271

Persulfate Oxidation of Gasoline Compounds  

NASA Astrophysics Data System (ADS)

In situ chemical oxidation (ISCO) using persulfate is a promising remediation technology that can be potentially applied to a wide range of organic contaminants. Gasoline compounds are of particular interest because they extensively impact the soil and groundwater, and are highly persistent and toxic. In this investigation, destruction of specific gasoline compounds (benzene, toluene, ethylbenzenes, xylenes, trimethylbenzenes (TMBs) and naphthalene), and fractions (F1 and F2) by activated and inactivated persulfate was studied at the bench-scale. Aqueous phase batch reactors (25 mL) for inactivated systems employed persulfate at two concentrations (1 or 20 g/L), and activated systems were conducted with a persulfate concentration of 20 g/L. In the activated systems, the ability of hydrogen peroxide or chelated-ferrous as an activator was examined at two experimental conditions (peroxide molar ratio 0.1 and 1.0 with respect to persulfate; and citric acid chelated ferrous at 150 and 600 mg/L). All treatments and controls contained an initial gasoline concentration of approximately 25 mg/L and were run in triplicate. Sampling for gasoline compounds was conducted over <28 day reaction period. The controls showed insignificant degradation for all the gasoline compounds and fractions examined while inactivated persulfate at 1 g/L showed little (<10%) decrease in the concentration of gasoline compounds over the 28 day reaction period. Inactivated persulfate at 20 g/L demonstrated a significant decrease in the aqueous concentration of BTEX (>99%), TMB (>94%) and naphthalene (>71%). Oxidation of the F1 fraction (>94%) was more pronounced than the F2 fraction (>80%), and >93% TPH was oxidized. Use of peroxide as an activator at a molar ratio of 0.1 improved the destruction of TMBs (>99%) and naphthalene (>85%) while maintaining the high removal of BTEX (>99%) compounds. Increase in activator strength (molar ratio 1.0) decreased the destruction of xylenes (>86%) and TMBs (>81%). The decrease in concentration of all the compounds was higher for a molar ratio of 1.0 (<27%) as compared with a molar ratio of 0.1 (<11%). The activation by ferrous concentration resulted in higher oxidation of compounds (except naphthalene) as compared with unactivated or peroxide activated persulfate. 1,3,5-TMB was completed oxidized after 4 days using higher chelated ferrous concentration and after 12 days using lower chelated ferrous concentration for persulfate activation. In general, increase in chelated ferrous concentration resulted in higher oxidation of the gasoline compounds. While oxidation of F1 fraction was similar for two ferrous activation conditions, the oxidation of F2 fraction was lower when ferrous activation at 600 mg/L was employed. Use of persulfate at high dosages by itself or in combination with higher doses of chelated ferrous or optimum doses of peroxide as an activator seems to be a viable option for remediation of gasoline compounds examined in this study. Persulfate appears to be particularly effective in the oxidation of BTEX compounds, but may require ferrous activation for a complete oxidation of TMBs and peroxide activation for oxidation of naphthalene.

Sra, K.; Thomson, N.; Barker, J.

2009-05-01

272

Extraterrestrial Organic Compounds in Meteorites  

Microsoft Academic Search

Many organic compounds or their precursorsfound in meteorites originated in the interstellar or circumstellarmedium and were later incorporated intoplanetesimals during the formation of thesolar system. There they either survivedintact or underwent further processing tosynthesize secondary products on themeteorite parent body.The most distinct feature of CI and CM carbonaceouschondrites, two typesof stony meteorites, is their high carbon content(up to 3% of

OLIVER BOTTAand; Jeffrey L. Bada

2002-01-01

273

Absorption of different lead compounds  

PubMed Central

A rapid method for the determination of relative absorption of dietary lead by rats is described. The influence of age, weight and dose rate has been determined and using standard conditions the tissue lead content of blood, kidney and femur are significantly correlated with each other and are a function of ingested lead. Eight lead compounds were evaluated using this technique and the findings related to lead acetate as a reference compound. Of the inorganic preparations studied, lead carbonate (basic) and metallic lead showed a twelve-fold difference in absorption, with the remaining compounds giving intermediate values. The absorption of lead from four organic compounds was determined from diets containing 7·5% corn oil added to the standard diet. Lead tallate was absorbed to the same degree as lead acetate, but lesser absorptions resulted from lead octoate, naphthenate and alsynate. The addition of corn oil to a final concentration of 7·5% of the diet enhanced the absorption of lead acetate. PMID:1208290

Barltrop, D.; Meek, F.

1975-01-01

274

Aluminum compounds as vaccine adjuvants  

Microsoft Academic Search

Aluminum compounds are the only adjuvants used widely with routine human vaccines and are the most common adjuvants in veterinary vaccines also. Though there has been a search for alternate adjuvants, aluminum adjuvants will continue to be used for many years due to their good track record of safety, low cost and adjuvanticity with a variety of antigens. For infections

Rajesh K Gupta

1998-01-01

275

Cancer prevention with natural compounds.  

PubMed

Botanical and nutritional compounds have been used for the treatment of cancer throughout history. These compounds also may be useful in the prevention of cancer. Population studies suggest that a reduced risk of cancer is associated with high consumption of vegetables and fruits. Thus, the cancer chemopreventive potential of naturally occurring phytochemicals is of great interest. There are numerous reports of cancer chemopreventive activity of dietary botanicals, including cruciferous vegetables such as cabbage and broccoli, Allium vegetables such as garlic and onion, green tea, Citrus fruits, soybeans, tomatoes, berries, and ginger, as well as medicinal plants. Several lead compounds, such as genistein (from soybeans), lycopene (from tomatoes), brassinin (from cruciferous vegetables), sulforaphane (from asparagus), indole-3-carbinol (from broccoli), and resveratrol (from grapes and peanuts) are in preclinical or clinical trials for cancer chemoprevention. Phytochemicals have great potential in cancer prevention because of their safety, low cost, and oral bioavailability. In this review, we discuss potential natural cancer preventive compounds and their mechanisms of action. PMID:20709209

Gullett, Norleena P; Ruhul Amin, A R M; Bayraktar, Soley; Pezzuto, John M; Shin, Dong M; Khuri, Fadlo R; Aggarwal, Bharat B; Surh, Young-Joon; Kucuk, Omer

2010-06-01

276

Bioactive compounds from Peperomia pellucida.  

PubMed

Five new compounds (1-5), including two secolignans, two tetrahydrofuran lignans, and one highly methoxylated dihydronaphthalenone, were isolated from the whole plant of Peperomia pellucida. These compounds were accompanied by the known peperomins A, B, C, and E, 7,8-trans-8,8'-trans-7',8'-cis-7,7'-bis(5-methoxy-3,4-methylenedioxyphenyl)-8-acetoxymethyl-8'-hydroxymethyltetrahydrofuran, 7,8-trans-8,8'-trans-7',8'-cis-7-(5-methoxy-3,4-methylenedioxyphenyl)-7'-(4-hydroxy-3,5-dimethoxyphenyl)-8,8'-diacetoxymethyltetrahydrofuran, sesamin, and isoswertisin. New structures were elucidated mainly by NMR and MS techniques, and anticancer activities evaluated in HL-60, MCF-7, and HeLa cell lines. Compound 1 and peperomin E show growth inhibitory effects on the three cancer cell lines with IC(50) values ranging between 1.4 and 9.1 and between 1.8 and 11.1 microM, respectively. Compound 2 has a weak suppressive activity on HL-60 cells (IC(50) = 10.8 microM), while 7,8-trans-8,8'-trans-7',8'-cis-7,7'-bis(5-methoxy-3,4-methylenedioxyphenyl)-8-acetoxymethyl-8'-hydroxymethyltetrahydrofuran exhibits estrogen-like properties (EC(50) = 3.1 microM) in CV-1 cells transfected with human estrogen receptor (ERalpha). PMID:16499324

Xu, Su; Li, Na; Ning, Meng-Meng; Zhou, Cai-Hong; Yang, Qiao-Rong; Wang, Ming-Wei

2006-02-01

277

[Perfluorinated compounds in potable water].  

PubMed

In a pilot study perfluorinated compounds such as perfluorobutane sulfonate (PFBS), perfluorohexane suflonate (PFHS), perfluorooctane sulfonate (PFOS), perfluorooctane sulfonamide (PFOSA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorotetradecanoic acid (PFTeDA), perfluorohexadecanoic acid (PFHxDA) and perfluorooctadecanoic acid (PFOcDA) have been determined in the Japanese and Polish brands of bottled mineral water and in tap water. Bottled mineral water from both countries contained ultratrace amounts of some perfluorinated compounds, and higher degree of contamination showed tap water. PFOS and PFOA concentrations were much below threshold level for toxic effects, and Hazard Quotient (HQ) was much < 1. PMID:19143425

Rostkowski, Pawe?; Taniyasu, Sachi; Yamashita, Nobuyoshi; Falandysz, Jerzy

2008-01-01

278

Alkylation of organic aromatic compounds  

DOEpatents

Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a molecular sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene to about the mid point of the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 figures.

Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

1993-09-07

279

Alkylation of organic aromatic compounds  

DOEpatents

Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a molecular sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.

Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

1994-06-14

280

Bacterial Degradation of Aromatic Compounds  

PubMed Central

Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms. PMID:19440284

Seo, Jong-Su; Keum, Young-Soo; Li, Qing X.

2009-01-01

281

Alkylation of organic aromatic compounds  

DOEpatents

Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

Smith, Jr., Lawrence A. (Houston, TX)

1989-01-01

282

Alkylation of organic aromatic compounds  

DOEpatents

Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.

Smith, L.A. Jr.

1989-07-18

283

Alkylation of organic aromatic compounds  

DOEpatents

Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene to about the mid point of the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

Smith, Jr., Lawrence A. (Bellaire, TX); Arganbright, Robert P. (Seabrook, TX); Hearn, Dennis (Houston, TX)

1993-01-01

284

Alkylation of organic aromatic compounds  

DOEpatents

Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C.sub.2 to C.sub.10 olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80.degree. C. to 500.degree. C., using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms.

Smith, Jr., Lawrence A. (Bellaire, TX); Arganbright, Robert P. (Seabrook, TX); Hearn, Dennis (Houston, TX)

1994-01-01

285

Catalytic Decomposition of Organophosphorus Compounds  

NASA Astrophysics Data System (ADS)

Organophosphorus compounds have several applications (agricultural, industrial, and military). Nevertheless, assessments of the hazards from these applications quite often do not take into account chemical processes during their interactions with environment. The management of contaminants requires considerable knowledge and understanding of contaminant behavior. Unique properties of clay minerals and metal oxides, such as high adsorption and catalytic ability, have resulted in their applications as natural adsorbents and catalysts in the development of cleanup technologies. Knowledge of molecular structure, transformation mechanisms, and the spectrum of potential intermediates/products of the contaminant decomposition is helpful for developing remediation processes. An understanding of the physical characteristics of the adsorption sites of selected soil ingredients, the physical and chemical characteristics of the contaminant, details of sorption of contaminants on soil and in water solution, and also their distribution within the environment is of particular interest. Application of computational chemistry (CC) can provide deeper insight into the aforementioned characteristics of organophosphorus compounds.

Michalkova, A.; Leszczynski, J.

286

Phenolic compounds from Potentilla alba  

Microsoft Academic Search

HPLC was used to determine the phenolic compounds. Portions (500 mg) of ground samples of air-dried raw material were weighed in 5-mL volumetric tubes. The volume was adjusted to the mark with MeOH (90%). The samples were irradiated for 30 min in an ultrasonic bath, left at room temperature for 3–4 h, placed for 15 min in the ultrasonic bath,

A. M. Kovaleva; E. R. Abdulkafarova

2011-01-01

287

Triorganotin compounds as antimicrobial agents.  

PubMed

Six triorganotin derivatives of thiolupinine(1-mercaptolupinane), 2-mercaptobenzoxazole and 2-mercaptobenzothiazole were prepared and tested against several bacteria, fungi and protozoa. Most compounds exhibited high activity against the tested microorganisms and particularly worth noting was the activity of triethyltin lupinylsulfide on Gram-negative strains. Triethylgermanium lupinylsulfide was also prepared but was devoid of action on the whole set of tested microorganisms. PMID:10384717

Novelli, F; Recine, M; Sparatore, F; Juliano, C

1999-04-30

288

Compounds That Promote Seed Germination  

NSDL National Science Digital Library

The two molecules for this month come from the section Compound in Smoke Provides the Spark for Germination in the article about "Research Advances" by Angela G. King. These molecules have been demonstrated to stimulate seed germination under various conditions. The butenolide moiety is frequently encountered in natural products. An interesting approach to the synthesis of such molecules can be found in this Organic Letters article (accessed January 2005).

289

TRP modulation by natural compounds.  

PubMed

The use of medicinal plants or other naturally derived products to relieve illness can be traced back over several millennia, and these natural products are still extensively used nowadays. Studies on natural products have, over the years, enormously contributed to the development of therapeutic drugs used in modern medicine. By means of the use of these substances as selective agonists, antagonists, enzyme inhibitors or activators, it has been possible to understand the complex function of many relevant targets. For instance, in an attempt to understand how pepper species evoke hot and painful actions, the pungent and active constituent capsaicin (from Capsicum sp.) was isolated in 1846 and the receptor for the biological actions of capsaicin was cloned in 1997, which is now known as TRPV1 (transient receptor potential vanilloid 1). Thus, TRPV1 agonists and antagonists have currently been tested in order to find new drug classes to treat different disorders. Indeed, the transient receptor potential (TRP) proteins are targets for several natural compounds, and antagonists of TRPs have been synthesised based on the knowledge of naturally derived products. In this context, this chapter focuses on naturally derived compounds (from plants and animals) that are reported to be able to modulate TRP channels. To clarify and make the understanding of the modulatory effects of natural compounds on TRPs easier, this chapter is divided into groups according to TRP subfamilies: TRPV (TRP vanilloid), TRPA (TRP ankyrin), TRPM (TRP melastatin), TRPC (TRP canonical) and TRPP (TRP polycystin). A general overview on the naturally derived compounds that modulate TRPs is depicted in Table 1. PMID:24961985

Meotti, Flavia Carla; Lemos de Andrade, Edinéia; Calixto, João B

2014-01-01

290

Catalytic Decomposition of Organophosphorus Compounds  

Microsoft Academic Search

\\u000a Organophosphorus compounds have several applications (agricultural, industrial, and military). Nevertheless, assessments of\\u000a the hazards from these applications quite often do not take into account chemical processes during their interactions with\\u000a environment. The management of contaminants requires considerable knowledge and understanding of contaminant behavior. Unique\\u000a properties of clay minerals and metal oxides, such as high adsorption and catalytic ability, have resulted

A. Michalkova; J. Leszczynski

2010-01-01

291

Compound facial expressions of emotion  

PubMed Central

Understanding the different categories of facial expressions of emotion regularly used by us is essential to gain insights into human cognition and affect as well as for the design of computational models and perceptual interfaces. Past research on facial expressions of emotion has focused on the study of six basic categories—happiness, surprise, anger, sadness, fear, and disgust. However, many more facial expressions of emotion exist and are used regularly by humans. This paper describes an important group of expressions, which we call compound emotion categories. Compound emotions are those that can be constructed by combining basic component categories to create new ones. For instance, happily surprised and angrily surprised are two distinct compound emotion categories. The present work defines 21 distinct emotion categories. Sample images of their facial expressions were collected from 230 human subjects. A Facial Action Coding System analysis shows the production of these 21 categories is different but consistent with the subordinate categories they represent (e.g., a happily surprised expression combines muscle movements observed in happiness and surprised). We show that these differences are sufficient to distinguish between the 21 defined categories. We then use a computational model of face perception to demonstrate that most of these categories are also visually discriminable from one another. PMID:24706770

Du, Shichuan; Tao, Yong; Martinez, Aleix M.

2014-01-01

292

Rotor phases in compound semiconductors  

SciTech Connect

Quasi-elastic neutron scattering is used to study the disordering processes in two classes of semiconductor: I-IV Zintl compounds and the phosphorus-selenium system. Two alkali-metal-polyvalent metal Zintl compounds, CsPb and NaSn, exhibit a two-stage melting process with high-temperature solid phases characterized by rapid dynamical disorder. In CsPb this disorder is clearly associated with rapid reorientations of polyanions with the cations participating in the dynamical disorder on the same time scale. In NaSn the disorder is associated with fast reorientations of the polyanions closely coupled to a slower migration of the cations. The two high-temperature solid phases of the molecular crystal P{sub 4}Se{sub 3} are confirmed to be rotor phases with small but significant differences in the reorientational motions in the two phases. Zintl compounds are formed from an electropositive metal A and an electronegative metal on semimetal M. Electron transfer from A to M, along with directional bonding between the M-ions, leads to chemical behavior in these ions characteristic of elements to the right of M in the periodic table.

Price, D.L.; Saboungi, M.L. [Argonne National Lab., IL (United States). Materials Science Div.; Howells, W.S. [Rutherford-Appleton Lab., Chilton (United Kingdom)

1994-11-01

293

Extraterrestrial Organic Compounds in Meteorites  

NASA Astrophysics Data System (ADS)

Many organic compounds or their precursorsfound in meteorites originated in the interstellar or circumstellarmedium and were later incorporated intoplanetesimals during the formation of thesolar system. There they either survivedintact or underwent further processing tosynthesize secondary products on themeteorite parent body.The most distinct feature of CI and CM carbonaceouschondrites, two typesof stony meteorites, is their high carbon content(up to 3% of weight), either in theform of carbonates or of organic compounds. The bulkof the organic carbon consistsof an insoluble macromolecular material with a complexstructure. Also present is asoluble organic fraction, which has been analyzedby several separation and analyticalprocedures. Low detection limits can be achievedby derivatization of the organicmolecules with reagents that allow for analysisby gas chromatography/massspectroscopy and high performance liquidchromatography. The CM meteoriteMurchison has been found to contain more than70 extraterrestrial amino acids andseveral other classes of compounds includingcarboxylic acids, hydroxy carboxylicacids, sulphonic and phosphonic acids, aliphatic,aromatic and polar hydrocarbons,fullerenes, heterocycles as well as carbonylcompounds, alcohols, amines and amides.The organic matter was found to be enriched indeuterium, and distinct organiccompounds show isotopic enrichments of carbon andnitrogen relative to terrestrialmatter.

Botta, Oliver; Bada, Jeffrey L.

294

Compound Interest to e and i  

NSDL National Science Digital Library

Graphing and exploring simple interest and compound interest. Examples of interest earned on one dollar at 6 percent compounded daily, monthly, quarterly, annually. Patterns, infinite sequence. Sample problems with some answers from Chapter 11 of Don Cohen's worksheet book.

Cohen, Donald, 1939-

2007-04-08

295

Hyperpolarizable compounds and devices fabricated therefrom  

DOEpatents

Substituted compounds having relatively large molecular first order hyperpolarizabilities are provided, along with devices and materials containing them. In general, the compounds bear electron-donating and electron-withdrawing chemical substituents on a polyheterocyclic core. 13 figs.

Therien, M.J.; DiMagno, S.G.

1998-07-21

296

Aroma compounds in fresh cut pomegranate arils.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Little published information exists regarding flavor and aroma compounds in pomegranate (Punica granatum). Although arils have fruity and sweet characteristics, we found no publications describing actual compounds responsible for their typical flavor. Since most commercial usage of pomegranates in...

297

Hyperpolarizable compounds and devices fabricated therefrom  

DOEpatents

Substituted compounds having relatively large molecular first order hyperpolarizabilities are provided, along with devices and materials containing them. In general, the compounds bear electron-donating and electron-withdrawing chemical substituents on a polyheterocyclic core.

Therien, Michael J. (Philadelphia, PA); DiMagno, Stephen G. (Lincoln, NE)

1998-01-01

298

Feedback Capacity of the Compound Channel  

E-print Network

In this work, we find the capacity of a compound finite-state channel (FSC) with time-invariant deterministic feedback. We consider the use of fixed length block codes over the compound channel. Our achievability result ...

Shrader, Brooke E.

299

The Chemistry of Highly Fluorinated Compounds  

NSDL National Science Digital Library

The featured molecules for January come from the paper Fluorous Compounds and Their Role in Separation Chemistry by Maria Angeles Ubeda and Roman Dembinski. This paper explores the use of highly fluorinated compounds as solvents, catalysts, and reagents.

300

A comparison of two compound critiquing systems  

Microsoft Academic Search

Compound critiques allow users to simultaneously express directional preferences over several product attributes. Pre- senting the user with compound critiques is not a new idea. The original Find-Me Systems (e.g., Car Navigator) showed static compound critiques; they didn't change irrespective of user preferences or the product availability. Recently, a number of techniques for dynamically generating compound critiques have been proposed.

James Reilly; Jiyong Zhang; Lorraine Mcginty; Pearl Pu; Barry Smyth

2007-01-01

301

Determination of organic compounds in bottled waters  

Microsoft Academic Search

The presence of organic compounds in bottled waters available in the Greek market and their fate when the representative samples exposed at different conditions were the main purposes of this study. The determination of the organic compounds was performed by gas chromatography–mass spectrometry techniques. Disinfection by-products compounds, such as trihalomethanes (THMs) and haloacetic acids (HAAs), were detected at low concentrations

Stavroula V. Leivadara; Anastasia D. Nikolaou; Themistokles D. Lekkas

2008-01-01

302

Thin films of mixed metal compounds  

DOEpatents

A compositionally uniform thin film of a mixed metal compound is formed by simultaneously evaporating a first metal compound and a second metal compound from independent sources. The mean free path between the vapor particles is reduced by a gas and the mixed vapors are deposited uniformly. The invention finds particular utility in forming thin film heterojunction solar cells.

Mickelsen, Reid A. (Bellevue, WA); Chen, Wen S. (Seattle, WA)

1985-01-01

303

Compound words and structure in the lexicon  

Microsoft Academic Search

The structure of lexical entries and the status of lexical decomposition remain controversial. In the psycholinguistic literature, one aspect of this debate concerns the psychological reality of the morphological complexity difference between compound words (teacup) and single words (crescent). The present study investigates morphological decomposition in compound words using visual lexical decision with simultaneous magnetoencephalography (MEG), comparing compounds, single words,

Robert Fiorentino; David Poeppel

2007-01-01

304

Compounds that Abrogate the G2 Checkpoint  

Microsoft Academic Search

This chapter summarizes the theoretical background of cancer therapeutics that abrogate the cell cycle G2 checkpoint and reviews\\u000a the molecular mechanism of the G2 checkpoint s cascade. In addition, screening procedures to identify candidate compounds,\\u000a currently available compounds, and compounds in clinical trials with G2 checkpoint-abrogating potential are discussed.

Takumi Kawabe

305

The Modification of Compounds by Attributive Adjectives  

ERIC Educational Resources Information Center

This paper examines the modification of nominal compounds by attributive adjectives in English. It draws on a distinction between compound-external (i.e. syntactic) and compound-internal (i.e. morphological) modification. An analysis is presented of more than 1000 pertinent cases, which are roughly equally divided into two-, three- and four-noun…

Berg, Thomas

2011-01-01

306

Basics of compounding with balsams.  

PubMed

Balsams have been used in pharmacy for centuries for many different purposes. Balsams include benzoin, Peruvian balsam, storax, and tolu balsam. Balsams are aromatic and usually oily resinous substances flowing from various plants and generally containing some amount of benzoic or cinnamic acid. Historically, they have been used orally and topically in various formulations. Today, their primary use is topically in solutions, ointments, creams, and lotions. Today, the most common use would be in diaper ointments and to treat various skin disorders. Pharmacists are still called upon to compound various preparations using balsams. PMID:24579300

Allen, Loyd V

2013-01-01

307

BBC Bitesize: Compounds and Mixtures  

NSDL National Science Digital Library

This animated tutorial for grades 6-9, published by the British Broadcasting Corporation, explores the molecular basis of compounds and mixtures. It is written in "bite-size" pieces so that adolescent learners can grasp the concepts more easily and connect information with prior knowledge. Each page is supplemented with audio narration and illustrations. Learners will try to fuse or separate elements, giving them insight into the bonding process without introducing advanced vocabulary. They will also view animations of filtration and evaporation. The tutorial ends with a brief quiz that allows students to self-test their understanding.

Bitesize, General C.

2011-06-27

308

[Anticancer activity of oxovanadium compounds].  

PubMed

Cytotoxic and antitumor activity of the biligand vanadyl derivative of L-malic acid (bis(L-malato)oxovanadium(IV) (VO(mal)2) was investigated in comparison with inorganic vanadium(IV) compound--vanadyl sulfate (VOSO4) and also with oxovanadium monocomplex with L-malic acid (VO(mal)) and vanadyl biscomplex with acetylacetonate. In this purpose the effect of vanadyl compounds on growth of normal human skin fibroblasts and tumor cells of different lines: mouse fibrosarcoma (L929), rat pheochromocytome (PC12), human liver carcinoma (HepG2), virus transformated mouse fibroblast (NIN 3T3), virus transformated cells of human kidney (293) were investigated. The results showed that VO(mal)2 was not toxic for normal human skin fibroblasts but considerably inhibited growth of cancer cells in culture. Cytotoxic antitumor effect of vanadium complexes was found to be dependent on incubation time and concentration and on type of cells and nature of ligands of the central group of the complex (VO2+). These studies provide evidence that VO(mal)2 may be considered as a potential antitumor agent due to its low toxicity in non-tumor cells and significant anticancer activity. PMID:23987068

Abakumova, O Iu; Podobed, O V; Beliaeva, N F; Tochilkin, A I

2013-01-01

309

Valuable compounds in macroalgae extracts.  

PubMed

Bioactive compounds present in ethanolic extracts from 18 macroalgae of the Portuguese coast were analysed by gas chromatography-mass spectrometry (GC-MS), leading to the characterization of 14 compounds: proline, phloroglucinol, mannitol, 8 fatty acids and 3 sterols. A dose-dependent response against enzymes with biological significance (?-glucosidase, acetylcholinesterase and butyrylcholinesterase) and free radicals (DPPH, nitric oxide, superoxide and hydroxyl) was found, Phaeophyta being the most promising group. A PCA analysis was performed and allowed the establishment of a correlation between the algae chemical composition and the biological activity. Cystoseira tamariscifolia (Hudson) Papenfuss, Cystoseira nodicaulis (Withering) M. Roberts, Cystoseira usneoides (Linnaeus) M. Roberts and Fucus spiralis Linnaeus are among the most active species, which is in accordance with their higher contents in phloroglucinol, mannitol, oleic, arachidonic and eicosapentaenoic acids, and fucosterol. The results point to the potential interest of the use of Phaeophyta species as food additives, due to their potent antiradical activities, and especially highlights the importance of F. spiralis in the food chain of Mediterranean countries. Moreover, the incorporation of the extracts of these species in food products, nutraceutical and pharmaceutical preparations for human health should also be instigated, since they can suppress hyperglycemia and inhibit cholinesterases. PMID:23411314

Andrade, Paula B; Barbosa, Mariana; Matos, Rui Pedro; Lopes, Graciliana; Vinholes, Juliana; Mouga, Teresa; Valentão, Patrícia

2013-06-01

310

Corrosion Preventive Compounds Lifetime Testing  

NASA Technical Reports Server (NTRS)

Lifetime Testing of Corrosion Preventive Compounds (CPCs) was performed to quantify performance in the various environments to which the Space Shuttle Orbiter is exposed during a flight cycle. Three CPCs are approved for use on the Orbiter: RD Calcium Grease, Dinitrol AV-30, and Braycote 601 EF. These CPCs have been rigorously tested to prove that they mitigate corrosion in typical environments, but little information is available on how they perform in the unique combination of the coastal environment at the launch pad, the vacuum of low-earth orbit, and the extreme heat of reentry. Currently, there is no lifetime or reapplication schedule established for these compounds that is based on this combination of environmental conditions. Aluminum 2024 coupons were coated with the three CPCs and exposed to conditions that simulate the environments to which the Orbiter is exposed. Uncoated Aluminum 2024 coupons were exposed to the environmental conditions as a control. Visual inspection and Electro- Impedance Spectroscopy (EIS) were performed on the samples in order to determine the effectiveness of the CPCs. The samples were processed through five mission life cycles or until the visual inspection revealed the initiation of corrosion and EIS indicated severe degradation of the coating.

Hale, Stephanie M.; Kammerer, Catherine C.; Copp, Tracy L.

2007-01-01

311

Corrosion Preventive Compounds Lifetime Testing  

NASA Technical Reports Server (NTRS)

Lifetime Testing of Corrosion Preventive Compounds (CPCs) was performed to quantify performance in the various environments to which the Space Shuttle Orbiter is exposed during a flight cycle. Three CPCs are approved for use on the Orbiter: HD Calcium Grease, Dinitrol AV-30, and Braycote 601 EF. These CPCs have been rigorously tested to prove that they mitigate corrosion in typical environments, but little information is available on how they perform in the unique combination of the coastal environment at the launch pad, the vacuum of low-earth orbit, and the extreme heat of reentry. Currently, there is no lifetime or reapplication schedule established for these compounds that is based on this combination of environmental conditions. Aluminum 2024 coupons were coated with the three CPCs and exposed to conditions that simulate the environments to which the Orbiter is exposed. Uncoated Aluminum 2024 coupons were exposed to the environmental conditions as a control. Visual inspection and Electro- Impedance Spectroscopy (EIS) were performed on the samples in order to determine the effectiveness of the CPCs. The samples were processed through five mission life cycles or until the visual inspection revealed the initiation of corrosion and EIS indicated severe degradation of the coating.

Hale, Stephanie M.; Kammerer, Catherine C.

2007-01-01

312

Prebiotic Evolution of Nitrogen Compounds  

NASA Technical Reports Server (NTRS)

Support from this four year grant has funded our research on two general problems. One involves attempts to model the abiotic formation of simple source compounds for functional biomolecules, their concentration from dilute state in the hydrosphere and, in several cases, surface induced reactions to form precursor monomers for bioactive end products (refs. 1-5). Because of the pervasiveness and antiquity of phosphate based biochemistry and the catalytic activity of RNA we have exploring the hypothesis of an RNA World as an early stage in the emergence of life. This concept is now rather generally considered, but has been questioned due to the earlier lack of an experimentally demonstrated successful scheme for the spontaneous formation of ribose phosphate, the key backbone molecule in RNA. That impediment has now been removed. This has been achieved by demonstrating probable sources of activated (condensed) highly soluble and strongly sorbed phosphates in nature (Refs. 1,2) and effective condensation of aldehyde phosphates to form ribose phosphate in high yield (ref.6), thereby placing the RNA World concept on a somewhat safer experimental footing. Like all work in this field these experiments are oversimplifications that largely ignore competing side reactions with other compounds expected to be present. None the less our choice of experimental conditions aim at selective processes that eliminate interfering reactions. We have also sought to narrow the credibility gap by simulating geophysically and geochemically plausible conditions surrounding the putative prebiotic reactions.

Arrhenius, G.

1999-01-01

313

Compound prism design principles, I  

PubMed Central

Prisms have been needlessly neglected as components used in modern optical design. In optical throughput, stray light, flexibility, and in their ability to be used in direct-view geometry, they excel over gratings. Here we show that even their well-known weak dispersion relative to gratings has been overrated by designing doublet and double Amici direct-vision compound prisms that have 14° and 23° of dispersion across the visible spectrum, equivalent to 800 and 1300 lines/mm gratings. By taking advantage of the multiple degrees of freedom available in a compound prism design, we also show prisms whose angular dispersion shows improved linearity in wavelength. In order to achieve these designs, we exploit the well-behaved nature of prism design space to write customized algorithms that optimize directly in the nonlinear design space. Using these algorithms, we showcase a number of prism designs that illustrate a performance and flexibility that goes beyond what has often been considered possible with prisms. PMID:22423145

Hagen, Nathan; Tkaczyk, Tomasz S.

2011-01-01

314

Elastomer Compound Developed for High Wear Applications  

NASA Technical Reports Server (NTRS)

The U.S. Army is currently spending 300 million dollars per year replacing rubber track pads. An experimental rubber compound has been developed which exhibits 2 to 3 times greater service life than standard production pad compounds. To improve the service life of the tank track pads various aspects of rubber chemistry were explored including polymer, curing and reinforcing systems. Compounds that exhibited superior physical properties based on laboratory data were then fabricated into tank pads and field tested. This paper will discuss the compounding studies, laboratory data and field testing that led to the high wear elastomer compound.

Crawford, D.; Feuer, H.; Flanagan, D.; Rodriguez, G.; Teets, A.; Touchet, P.

1993-01-01

315

Method for purifying bidentate organophosphorous compounds  

DOEpatents

Bidentate organophosphorous compounds are purified of undesirable impurities by contacting a solution of the compounds with a mercuric nitrate solution to form an insoluble mercuric bidentate compound which precipitates while the impurities remain in solution. The precipitate is washed and then contacted with a mixture of an aqueous solution of a strong mercuric ion complexing agent and an organic solvent to complex the mercuric ion away from the bidentate compound which then dissolves in the solvent. The purified bidentate compounds are useful for extracting the actinide elements from aqueous acidic nuclear waste solutions.

McIsaac, Lyle D. (Blackfoot, ID); Krupa, Joseph F. (Idaho Falls, ID); Schroeder, Norman C. (Pocatello, ID)

1981-01-01

316

Thin films of mixed metal compounds  

DOEpatents

Disclosed is a thin film heterojunction solar cell, said heterojunction comprising a p-type I-III-IV[sub 2] chalcopyrite substrate and an overlying layer of an n-type ternary mixed metal compound wherein said ternary mixed metal compound is applied to said substrate by introducing the vapor of a first metal compound to a vessel containing said substrate from a first vapor source while simultaneously introducing a vapor of a second metal compound from a second vapor source of said vessel, said first and second metals comprising the metal components of said mixed metal compound; independently controlling the vaporization rate of said first and second vapor sources; reducing the mean free path between vapor particles in said vessel, said gas being present in an amount sufficient to induce homogeneity of said vapor mixture; and depositing said mixed metal compound on said substrate in the form of a uniform composition polycrystalline mixed metal compound. 5 figs.

Mickelsen, R.A.; Chen, W.S.

1985-06-11

317

Calorimetric studies of the interaction between the insulin-enhancing drug candidate bis(maltolato)oxovanadium(IV) (BMOV) and human serum apo-transferrin.  

PubMed

Bis(maltolato)oxovanadium(IV) (BMOV), and its ethylmaltol analog, bis(ethylmaltolato)oxovanadium(IV) (BEOV), are candidate insulin-enhancing agents for the treatment of type 2 diabetes mellitus; in mid-2008, BEOV advanced to phase II clinical testing. The interactions of BMOV and its inorganic congener, vanadyl sulfate (VOSO(4)), with human serum apo-transferrin (hTf) were investigated using differential scanning calorimetry (DSC). Addition of BMOV or VOSO(4) to apo-hTf resulted in an increase in thermal stability of both the C- and N-lobes of transferrin as a result of binding to either vanadyl compound. A series of DSC thermograms of hTf solutions containing different molar ratios of BMOV and VOSO(4) were used to determine binding constants; at 25 degrees C the binding constants of BMOV to the C- and N-lobes of apo-hTf were found to be 3 (+/-1)x10(5) and 1.8 (+/-0.7)x10(5)M(-1), respectively. The corresponding values for VOSO(4) were 1.7 (+/-0.3)x10(5) and 7 (+/-2)x10(4)M(-1). The results show that the vanadium species initially presented as either BMOV or VOSO(4) had similar affinities for human serum transferrin due to oxidation of solvated vanadyl(IV) prior to complexation to transferrin. Binding of metavanadate (VO(3)(-)) was confirmed by DSC and isothermal titration calorimetry (ITC) experiments of the interaction between sodium metavanadate (NaVO(3)) and hTf. PMID:19056126

Bordbar, Abdol-Khalegh; Creagh, A Louise; Mohammadi, Fakhrossadat; Haynes, Charles A; Orvig, Chris

2009-04-01

318

Dilithium Hexaorganostannate(IV) Compounds.  

PubMed

Hypercoordination of main-group elements such as the heavier Group?14 elements (silicon, germanium, tin, and lead) usually requires strong electron-withdrawing ligands and/or donating groups. Herein, we present the synthesis and characterization of two hexaaryltin(IV) dianions in form of their dilithium salts [Li2 (thf)2 {Sn(2-py(Me) )6 }] (py(Me) =C5 H3 N-5-Me) (2) and [Li2 {Sn(2-py(OtBu) )6 }] (py(OtBu) =C5 H3 N-6-OtBu) (3). Both complexes are stable in the solid state and solution under inert conditions. Theoretical investigations of compound 2 reveal a significant valence 5s-orbital contribution of the tin atom forming six strongly polarized tin-carbon bonds. PMID:25314245

Schrader, Ireen; Zeckert, Kornelia; Zahn, Stefan

2014-12-01

319

Alkylation of organic aromatic compounds  

DOEpatents

Aromatic compounds are alkylated in a combination reactor/distillation column comprising a vessel suitable for operating between 70 C and 500 C and from 0.5 to 20 atmospheres pressure; an inert distillation packing in the lower one-third of said vessel; solid acidic catalytic material such as zeolites or an acidic cation exchange resin supported in the middle one-third of said vessel; and inert distillation packing in the upper one-third of said vessel. A benzene inlet is located near the upper end of the vessel; an olefin inlet is juxtaposed with said solid acidic catalytic material; a bottoms outlet is positioned near the bottom of said vessel for removing said cumene and ethyl benzene; and an overhead outlet is placed at the top of said vessel for removing any unreacted benzene and olefin.

Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

1993-01-05

320

Phenolic compounds from Nymphaea odorata.  

PubMed

Assay-guided fractionation of the ethanol extract of Nymphaea odorata resulted in the identification of two lignans, one new (1) and one known (2), together with six known flavonol glycosides (3-8). The structures of 1-8 were established by spectroscopic analysis as nymphaeoside A (1), icariside E(4) (2), kaempferol 3-O-alpha-l-rhamnopyranoside (afzelin, 3), quercetin 3-O-alpha-l-rhamnopyranoside (4), myricetin 3-O-alpha-l-rhamnopyranoside (myricitrin, 5), quercetin 3-O-(6' '-O-acetyl)-beta-d-galactopyranoside (6), myricetin 3-O-beta-d-galactopyranoside (7), and myricetin 3-O-(6' '-O-acetyl)-beta-d-galactopyranoside (8). Compounds 3, 4, and 7 showed marginal inhibitory effect against fatty acid synthase with IC(50) values of 45, 50, and 25 microg/mL, respectively. PMID:12713413

Zhang, Zhizhen; ElSohly, Hala N; Li, Xing-Cong; Khan, Shabana I; Broedel, Sheldon E; Raulli, Robert E; Cihlar, Ronald L; Burandt, Charles; Walker, Larry A

2003-04-01

321

Volatile organic compound sensing devices  

DOEpatents

Apparatus employing vapochromic materials in the form of inorganic double complex salts which change color reversibly when exposed to volatile organic compound (VOC) vapors is adapted for VOC vapor detection, VOC aqueous matrix detection, and selective VOC vapor detection. The basic VOC vapochromic sensor is incorporated in various devices such as a ground probe sensor, a wristband sensor, a periodic sampling monitor, a soil/water penetrometer, an evaporative purge sensor, and various vacuum-based sensors which are particularly adapted for reversible/reusable detection, remote detection, continuous monitoring, or rapid screening of environmental remediation and waste management sites. The vapochromic sensor is used in combination with various fiber optic arrangements to provide a calibrated qualitative and/or quantitative indication of the presence of VOCs. 15 figs.

Lancaster, G.D.; Moore, G.A.; Stone, M.L.; Reagen, W.K.

1995-08-29

322

Alkylation of organic aromatic compounds  

DOEpatents

Aromatic compounds are alkylated in a combination reactor/distillation column comprising a vessel suitable for operating between 70.degree. C. and 500.degree. C. and from 0.5 to 20 atmospheres pressure; an inert distillation packing in the lower one-third of said vessel; solid acidic catalytic material such as zeolites or an acidic cation exchange resin supported in the middle one-third of said vessel; and inert distillation packing in the upper one-third of said vessel. A benzene inlet is located near the upper end of the vessel; an olefin inlet is juxtaposed with said solid acidic catalytic material; a bottoms outlet is positioned near the bottom of said vessel for removing said cumene and ethyl benzene; and an overhead outlet is placed at the top of said vessel for removing any unreacted benzene and olefin.

Smith, Jr., Lawrence A. (Bellaire, TX); Arganbright, Robert P. (Seabrook, TX); Hearn, Dennis (Houston, TX)

1993-01-01

323

Volatile organic compound sensing devices  

DOEpatents

Apparatus employing vapochromic materials in the form of inorganic double complex salts which change color reversibly when exposed to volatile organic compound (VOC) vapors is adapted for VOC vapor detection, VOC aqueous matrix detection, and selective VOC vapor detection. The basic VOC vapochromic sensor is incorporated in various devices such as a ground probe sensor, a wristband sensor, a periodic sampling monitor, a soil/water penetrometer, an evaporative purge sensor, and various vacuum-based sensors which are particularly adapted for reversible/reusable detection, remote detection, continuous monitoring, or rapid screening of environmental remediation and waste management sites. The vapochromic sensor is used in combination with various fiber optic arrangements to provide a calibrated qualitative and/or quantitative indication of the presence of VOCs.

Lancaster, Gregory D. (Idaho Falls, ID); Moore, Glenn A. (Idaho Falls, ID); Stone, Mark L. (Idaho Falls, ID); Reagen, William K. (Stillwater, MN)

1995-01-01

324

Synthesis and phase transitions of oxide-ion conducting compound La{sub 2}Mo{sub 2}O{sub 9} doped with alkaline metals  

SciTech Connect

The specific features of synthesis, polymorthism, and electric conductivity of oxide-ion conducting compounds La{sub 2-x}Me{sub x}Mo{sub 2}O{sub 9-y}, where Me = Na, K, Rb, or Cs, have been studied. Ceramic samples were obtained by solid-state synthesis in the temperature range of 960-1100 Degree-Sign C. The regions where solid solutions exist have been found to depend on the temperature of the sample firing. According to the calorimetric and electrophysical data, the phase transition from the monoclinic phase ({alpha}) to the cubic phase ({beta}) in samples doped with potassium and rubidium disappears at x = 0.02 and 0.04, respectively. In these cases the only transition from the cubic {beta}{sub ms} phase to the high-temperature cubic {beta} phase is observed near 450 Degree-Sign C. Doping with sodium and cesium does not suppress the {alpha} {yields} {beta} phase transition.

Kolesnikova, D. S.; Kharitonova, E. P.; Voronkova, V. I., E-mail: voronk@polly.phys.msu.ru [Moscow State University (Russian Federation)

2011-03-15

325

Electrohydrodynamics of a compound drop.  

PubMed

The behavior of a compound drop, comprising two concentric fluid spheres, in a uniform electric field is studied analytically. The governing electrohydrodynamic equations are solved for Newtonian and immiscible fluids in the framework of leaky-dielectric theory and in the limit of small electric field strength and fluid inertia. A detailed analysis of the electric and flow fields is presented and it is shown that there will be four possible flow patterns in and around the globule, in terms of the direction of the external flow (pole-to-equator vs equator-to-pole) and the number of vortices (single-vortex vs double vortices) in the shell, and that the senses of the net electric shear stresses at the surfaces of the inner and the outer drops and their relative importance are the key parameters in setting these patterns. A circulation map is constructed, which is used to infer about the likelihood of the flow patterns and transition from one pattern to another for representative fluid systems. For small distortion from the spherical shape, the deformations of the inner and the outer drops are found using normal stress balances at the corresponding surfaces. It is shown that there will be four possible modes for the deformation of the compound drop, which are determined by the net normal electric and hydrodynamic stresses at the pertinent surfaces. The dynamic responses of the inner and the outer drops for representative fluid systems are studied using a deformation map, which characterizes the possibilities of the deformation modes and transition from one mode to another as a function of the fluid properties. PMID:24125349

Behjatian, Ali; Esmaeeli, Asghar

2013-09-01

326

Lysis of cyanobacteria with volatile organic compounds.  

PubMed

One of bacteria collected from Lake Sagami, Japan, Brevibacillus sp., was found to have a lytic activity of cyanobacteria, but did not produce active compounds. Instead, the co-culturing of Microcystis with the Brevibacillus sp. enhanced the production of two volatile compounds, beta-cyclocitral and 3-methyl-1-butanol, and the former had a characteristic lytic activity. It was confirmed that these volatile compounds were derived from the cyanobacteria themselves. beta-Ionone, geosmin and 2-methylisoborneol derived from cyanobacteria and similar volatile compounds, terpenoids, produced by plants also had a lytic activity. The minimum inhibitory concentration values of the cyanobacterial metabolites were estimated to be higher than those of compounds from plants except for a few compounds. Among them, beta-cyclocitral only produced a characteristic color change of culture broth from green to blue. This color change is similar to the phenomenon observed when a sudden decline in growth of cyanobacteria begins in a natural environment. PMID:18179811

Ozaki, Keiko; Ohta, Akemi; Iwata, Chieko; Horikawa, Aki; Tsuji, Kiyomi; Ito, Emiko; Ikai, Yoshitomo; Harada, Ken-Ichi

2008-04-01

327

27 CFR 27.44 - Other compounds and preparations.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Other compounds and preparations. 27.44 Section 27...and Beer Liqueurs, Cordials, and Other Compounds and Preparations § 27.44 Other compounds and preparations. Compounds...

2010-04-01

328

27 CFR 27.44 - Other compounds and preparations.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Other compounds and preparations. 27.44 Section 27...and Beer Liqueurs, Cordials, and Other Compounds and Preparations § 27.44 Other compounds and preparations. Compounds...

2011-04-01

329

Computed structures of polyimides model compounds  

NASA Technical Reports Server (NTRS)

Using a semi-empirical approach, a computer study was made of 8 model compounds of polyimides. The compounds represent subunits from which NASA Langley Research Center has successfully synthesized polymers for aerospace high performance material application, including one of the most promising, LARC-TPI polymer. Three-dimensional graphic display as well as important molecular structure data pertaining to these 8 compounds are obtained.

Tai, H.; Phillips, D. H.

1990-01-01

330

Calorimetric, spectroscopic and structural investigations of phase polymorphism in [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3}. Part I  

SciTech Connect

Four crystalline phases of the coordination compound [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3} are identified by adiabatic calorimetry. Three phase transitions, one at T{sub C3}(IV{yields}III)=30.7 K, the second at T{sub C2}(III{yields}II)=91.7 K (both accompanied by comparable entropy changes 3.0 and 3.1 J K{sup -1} mol{sup -1}, respectively) and the third at T{sub C1}(II{yields}I)=241.6 K (accompanied by an entropy change of 8.1 J K{sup -1} mol{sup -1}) were discovered. X-ray single crystal diffraction (at 293 K) demonstrates that phase I is a highly dynamic disordered cubic phase (Fm3{sup Macron }m, No. 225) with two types of BF{sub 4}{sup -} anions differing in a degree of disorder. In phase II (at 170 K) the structure remains cubic (Ia3{sup Macron }, No. 206), with two different types of cations and four different types of anions. Splitting of certain IR bands connected with NH{sub 3} ligands at the observed phase transitions suggests a lowering of the symmetry of the [Ru(NH{sub 3}){sub 6}]{sup 3+} complex cation. Both NH{sub 3} ligands and BF{sub 4}{sup -} anions perform fast reorientations ({tau}{sub R} Almost-Equal-To 10{sup -12} s), which are significantly slowed down below the phase transition at T{sub C3}. {sup 1}H NMR studies led to estimate the values of the activation energy of NH{sub 3} ligands reorientation in the phases II and I as equal to {approx}8 kJ mol{sup -1}. In phase I the whole hexammineruthenium(III) cations reorientation as a tumbling process can be noticed. The activation energy value of this motion is {approx}24 kJ mol{sup -1}. {sup 19}F NMR studies give the values of the activation energy of BF{sub 4}{sup -} anions reorientation as {approx}6 kJ mol{sup -1}. Above the phase transition temperature half of BF{sub 4}{sup -} anions perform a tumbling motion with E{sub a} Almost-Equal-To 8 kJ mol{sup -1}. - Graphical abstract: A series of complementary methods, such as Adiabatic Calorimetry, Differential Scanning Calorimetry, Fourier Transform-Far and Middle Spectroscopy, proton and fluorine Nuclear Magnetic Resonance and structural methods reveal information about phase transitions in [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3}. Highlights: Black-Right-Pointing-Pointer Three novel phase transitions are found in [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3}. Black-Right-Pointing-Pointer The thermodynamic parameters of the phase transitions are derived. Black-Right-Pointing-Pointer The transitions are of order-disorder type. Black-Right-Pointing-Pointer The complex belongs to Fm3{sup Macron }m at 293 K and its symmetry changes to Ia3{sup Macron} at 170 K. Black-Right-Pointing-Pointer [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3} is a highly dynamically disordered crystal.

Dolega, Diana, E-mail: dolega@chemia.uj.edu.pl [Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow (Poland); Mikuli, Edward, E-mail: mikuli@chemia.uj.edu.pl [Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow (Poland); Inaba, Akira, E-mail: inaba@chem.sci.osaka-u.ac.jp [Research Center for Structural Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Gorska, Natalia, E-mail: gorska@chem.sci.osaka-u.ac.jp [Research Center for Structural Thermodynamics, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Holderna-Natkaniec, Krystyna, E-mail: natkanie@amu.edu.pl [Faculty of Physics, Adam Mickiewicz University, Umultowska 85, Poznan 61-614 (Poland); Nitek, Wojciech, E-mail: nitek@chemia.uj.edu.pl [Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow (Poland)

2013-01-15

331

Electronic structure and magnetism in actinide compounds  

NASA Astrophysics Data System (ADS)

A close relationship between electronic structure and magnetic properties is observed in actinide compounds. The exact nature of this relationship is under investigation. We present examples of a direct link between electronic structure and ordered magnetic moment and/or magnetization. Specifically, results obtained for cubic U, Np and Pu compounds and quasi-2D U compounds are be presented. In the case of cubic compounds, a direct relationship between binding energy of valence band features and magnetic moment will be discussed. A Stoner-like mechanism and simple mean-field explanation is proposed for ferromagnetic UTe.

Durakiewicz, T.; Joyce, J. J.; Lander, G. H.; Olson, C. G.; Butterfield, M. T.; Guziewicz, E.; Batista, C. D.; Arko, A. J.; Morales, L.; Mattenberger, K.; Vogt, O.

2006-05-01

332

Hydrodesulfurization catalysis by Chevrel phase compounds  

DOEpatents

A process is disclosed for the hydrodesulfurization of sulfur-containing hydrocarbon fuel with reduced ternary molybdenum sulfides, known as Chevrel phase compounds. Chevrel phase compounds of the general composition M.sub.x Mo.sub.6 S.sub.8, with M being Ho, Pb, Sn, Ag, In, Cu, Fe, Ni, or Co, were found to have hydrodesulfurization activities comparable to model unpromoted and cobalt-promoted MoS.sub.2 catalysts. The most active catalysts were the "large" cation compounds (Ho, Pb, Sn), and the least active catalysts were the "small" cation compounds (Cu, Fe, Ni, Co.).

McCarty, Kevin F. (Livermore, CA); Schrader, Glenn L. (Ames, IA)

1985-12-24

333

Persulfate Persistence and Treatability of Gasoline Compounds.  

E-print Network

??Petroleum hydrocarbons (PHCs) such as gasoline are ubiquitous organic compounds present at contaminated sites throughout the world. Accidental spills and leakage from underground storage tanks… (more)

Sra, Kanwartej Singh

2010-01-01

334

Compound cryopump for fusion reactors  

E-print Network

We reconsider an old idea: a three-stage compound cryopump for use in fusion reactors such as DEMO. The helium "ash" is adsorbed on a 4.5 K charcoal-coated surface, while deuterium and tritium are adsorbed at 15-22 K on a second charcoal-coated surface. The helium is released by raising the first surface to ~30 K. In a separate regeneration step, deuterium and tritium are released at ~110 K. In this way, the helium can be pre-separated from other species. In the simplest design, all three stages are in the same vessel, with a single valve to close the pump off from the tokamak during regeneration. In an alternative design, the three stages are in separate vessels, connected by valves, allowing the stages to regenerate without interfering with each other. The inclusion of the intermediate stage would not affect the overall pumping speed significantly. The downstream exhaust processing system could be scaled down, as much of the deuterium and tritium could be returned directly to the reactor. This could reduce ...

Kovari, M; Shephard, T

2013-01-01

335

Bioactive compounds from Vitex leptobotrys.  

PubMed

A new lignan, vitexkarinol (1), as well as a known lignan, neopaulownin (2), a known chalcone, 3-(4-hydroxyphenyl)-1-(2,4,6-trimethoxyphenyl)-2-propen-1-one (3), two known dehydroflavones, tsugafolin (4) and alpinetin (5), two known dipeptides, aurantiamide and aurantiamide acetate, a known sesquiterpene, vemopolyanthofuran, and five known carotenoid metabolites, vomifoliol, dihydrovomifoliol, dehydrovomifoliol, loliolide, and isololiolide, were isolated from the leaves and twigs of Vitex leptobotrys through bioassay-guided fractionation. The chalcone (3) was found to inhibit HIV-1 replication by 77% at 15.9 ?M, and the two dehydroflavones (4 and 5) showed weak anti-HIV activity with IC50 values of 118 and 130 ?M, respectively, while being devoid of cytotoxicity at 150 ?M. A chlorophyll-enriched fraction of V. leptobotrys, containing pheophorbide a, was found to inhibit the replication of HIV-1 by 80% at a concentration of 10 ?g/mL. Compounds 1 and 3 were further selected to be evaluated against 21 viral targets available at NIAID (National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA). PMID:24404757

Pan, Wenhui; Liu, Kanglun; Guan, Yifu; Tan, Ghee Teng; Hung, Nguyen Van; Cuong, Nguyen Manh; Soejarto, D Doel; Pezzuto, John M; Fong, Harry H S; Zhang, Hongjie

2014-03-28

336

A new compound from Geum rivale L.  

PubMed

A new compound, 1-O-methyl-6-O-caffeoyl-beta-D-glucopyranose (1), has been isolated from the aerial part of G. rivale, together with five known compounds, cecropiacic acid (2), niga-ichgoside (3), gallic acid (4), 1-o-protocatechuoylglucose (5), and sucrose (6). Their structures were elucidated by spectral methods and chemical reactions. PMID:12118512

Ming, Dong-Sheng; Jiang, Ren-Wang; But, Paul Pui-Hay; Towers, G H Neil; Yu, De-Quan

2002-09-01

337

(CHINA) PERFLUORINATED ORGANIC COMPOUND EXPOSURE ASSESSMENT RESEARCH  

EPA Science Inventory

A wide range of perfluorinated organic compounds (PFCs) has been used in a variety of industrial processes and consumer products. The most commonly studied PFCs include perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), but there are many more compounds in this c...

338

Antithrombotic phenolic compounds from Glycyrrhiza uralensis.  

PubMed

A new coumestan, named glycyrurol, and nine phenolic compounds were isolated from the ethyl acetate extract of the roots and rhizomes of Glycyrrhiza uralensis. Their structures were elucidated based on spectroscopic analysis and literature data, and anticoagulative assay found significant antithrombotic activity of compounds 4, 8 and 10. PMID:22197642

Tao, Wei-Wei; Duan, Jin-Ao; Yang, Nian-Yun; Tang, Yu-Ping; Liu, Meng-Zhu; Qian, Ye-Fei

2012-03-01

339

PERFLUORINATED ORGANIC COMPOUND EXPOSURE ASSESSMENT RESEARCH  

EPA Science Inventory

A wide range of perfluorinated organic compounds (PFCs) has been used in a variety of industrial processes and consumer products. The most commonly studied PFCs include perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), but there are many more compounds in this c...

340

Ambient Air Monitoring for Sulfur Compounds  

ERIC Educational Resources Information Center

A literature review of analytical techniques available for the study of compounds at low concentrations points up some of the areas where further research is needed. Compounds reviewed are sulfur dioxide, sulfuric acid, ammonium sulfate and bisulfate, metal sulfates, hydrogen sulfide, and organic sulfides. (BL)

Forrest, Joseph; Newman, Leonard

1973-01-01

341

Development of nonflammable potting compounds for spacecraft  

NASA Technical Reports Server (NTRS)

The requirements for nonflammable potting compounds for use in spacecraft electric and electronic equipment are discussed. The development of a suitable nonflammable compound is described. Flammability testing and acceptance criteria for Apollo spacecraft are presented. The dielectric properties of various ceramic materials used as conformal coatings are examined.

Kline, H. F.

1971-01-01

342

Organochlorine Compounds and Risk of Breast Cancer  

Cancer.gov

Dr. Tongzhang Zheng, of Yale University, New Haven, CT, and colleagues conducted a hospital-based case-control study in Connecticut to investigate risk for breast cancer associated with exposure to organochlorine compounds. Levels of organochlorine compounds are being measured in breast adipose (fatty) tissue and blood serum obtained from women who had surgery or biopsies for breast cancer or benign breast disease.

343

Care and Feeding of the Compound Microscope  

NSDL National Science Digital Library

This lab activity from the Biotechnology Alliance for Suncoast Biology Educators is intended to demonstrate appropriate use of a microscope. It covers the basic care and operation of a compound light microscope. The lesson includes information on how a compound microscope works, a diagram of its parts, tips for usage, a practice activity, and a checklist for putting the microscope away.

Keirle, Matt

344

VOLATILE ORGANIC COMPOUNDS (VOCS) CHAPTER 31.  

EPA Science Inventory

The term "volatile organic compounds' (VOCs) was originally coined to refer, as a class, to carbon-containing chemicals that participate in photochemical reactions in the ambient (outdoor) are. The regulatory definition of VOCs used by the U.S. EPA is: Any compound of carbon, ex...

345

Two new compounds from Ganoderma lucidum.  

PubMed

Two pairs of new enantiomers, lucidulactones A and B (1 and 2), and two known compounds were isolated from Ganoderma lucidum. Their structures were determined by means of spectroscopic methods. The chiral HPLC was used to separate the ( - )- and (+)-antipodes of the new compounds. PMID:25295637

Wang, Xin-Fang; Yan, Yong-Ming; Wang, Xin-Long; Ma, Xiu-Jing; Fu, Xue-Yan; Cheng, Yong-Xian

2014-10-01

346

An Account for Compound Prepositions in Farsi  

Microsoft Academic Search

There are some sorts of 'Preposition + Noun' combinations in Farsi that apparently a Prepositional Phrase almost behaves as Compound Prepositions. As they are not completely behaving as compounds, it is doubtful that the process of word formation is a morphological one. The analysis put forward by this paper proposes \\

Zahra Abolhassani Chime

2006-01-01

347

Nitroaromatic Compounds, from Synthesis to Biodegradation  

PubMed Central

Summary: Nitroaromatic compounds are relatively rare in nature and have been introduced into the environment mainly by human activities. This important class of industrial chemicals is widely used in the synthesis of many diverse products, including dyes, polymers, pesticides, and explosives. Unfortunately, their extensive use has led to environmental contamination of soil and groundwater. The nitro group, which provides chemical and functional diversity in these molecules, also contributes to the recalcitrance of these compounds to biodegradation. The electron-withdrawing nature of the nitro group, in concert with the stability of the benzene ring, makes nitroaromatic compounds resistant to oxidative degradation. Recalcitrance is further compounded by their acute toxicity, mutagenicity, and easy reduction into carcinogenic aromatic amines. Nitroaromatic compounds are hazardous to human health and are registered on the U.S. Environmental Protection Agency's list of priority pollutants for environmental remediation. Although the majority of these compounds are synthetic in nature, microorganisms in contaminated environments have rapidly adapted to their presence by evolving new biodegradation pathways that take advantage of them as sources of carbon, nitrogen, and energy. This review provides an overview of the synthesis of both man-made and biogenic nitroaromatic compounds, the bacteria that have been identified to grow on and completely mineralize nitroaromatic compounds, and the pathways that are present in these strains. The possible evolutionary origins of the newly evolved pathways are also discussed. PMID:20508249

Ju, Kou-San; Parales, Rebecca E.

2010-01-01

348

Perfluorinated Compounds: Emerging POPs with Potential Immunotoxicity  

EPA Science Inventory

Perfluorinated compounds (PFCs) have been recognized as an important class of environmental contaminants commonly detected in blood samples of both wildlife and humans. These compounds have been in use for more than 60 years as surface treatment chemicals, polymerization aids, an...

349

Superconductivity in iron compounds G. R. Stewart  

E-print Network

Superconductivity in iron compounds G. R. Stewart Department of Physics, University of Florida of superconductivity at Tc ¼ 26 K in fluorine-doped LaFeAsO inspired a worldwide effort to understand the nature of the superconductivity in this new class of compounds. These iron pnictide and chalcogenide (FePn/Ch) superconductors

Wu, Zhigang

350

SUPERCONDUCTIVITY OF TECHNETIUM ALLOYS AND COMPOUNDS  

Microsoft Academic Search

The superconducting transition temperatures of Mo- Tc alloys are ; reported. Critical field measurements of a 50 atomic per cent alloy indicate ; that it might be a promising material for superconducting magnets. The ; similarity of Tc and Re with respect to alloy and intermetallic compound ; formation is noted. The superconducting transition temperatures of the compounds ; ZrTcâ

V. B. Compton; E. Corenzwit; J. P. Maita; B. T. Matthias; F. J. Morin

1961-01-01

351

Crystal structure analysis of intermetallic compounds  

NASA Technical Reports Server (NTRS)

Study concerns crystal structures and lattice parameters for a number of new intermetallic compounds. Crystal structure data have been collected on equiatomic compounds, formed between an element of the Sc, Ti, V, or Cr group and an element of the Co or Ni group. The data, obtained by conventional methods, are presented in an easily usable tabular form.

Conner, R. A., Jr.; Downey, J. W.; Dwight, A. E.

1968-01-01

352

Exploring marine resources for bioactive compounds.  

PubMed

Biodiversity in the seas is only partly explored, although marine organisms are excellent sources for many industrial products. Through close co-operation between industrial and academic partners, it is possible to successfully collect, isolate and classify marine organisms, such as bacteria, fungi, micro- and macroalgae, cyanobacteria, and marine invertebrates from the oceans and seas globally. Extracts and purified compounds of these organisms can be studied for several therapeutically and industrially significant biological activities, including anticancer, anti-inflammatory, antiviral, antibacterial, and anticoagulant activities by applying a wide variety of screening tools, as well as for ion channel/receptor modulation and plant growth regulation. Chromatographic isolation of bioactive compounds will be followed by structural determination. Sustainable cultivation methods for promising organisms and biotechnological processes for selected compounds can be developed, as well as biosensors for monitoring the target compounds. The (semi)synthetic modification of marine-based bioactive compounds produces their new derivatives, structural analogs and mimetics that could serve as hit or lead compounds and be used to expand compound libraries based on marine natural products. The research innovations can be targeted for industrial product development in order to improve the growth and productivity of marine biotechnology. Marine research aims at a better understanding of environmentally conscious sourcing of marine biotechnology products and increased public awareness of marine biodiversity. Marine research is expected to offer novel marine-based lead compounds for industries and strengthen their product portfolios related to pharmaceutical, nutraceutical, cosmetic, agrochemical, food processing, material and biosensor applications. PMID:25203732

Kiuru, Paula; D?Auria, M Valeria; Muller, Christian D; Tammela, Päivi; Vuorela, Heikki; Yli-Kauhaluoma, Jari

2014-09-01

353

The Surface Tension of Pure Liquid Compounds  

Microsoft Academic Search

The surface tension tables presented herein are the result of a literature survey, evaluation, and compilation of data of some 2200 pure liquid compounds, 226 of which were reported for a single temperature. These are arranged with related compounds in the increasing order of their molecular weights. As far as possible the method of measurement, nature of atmosphere to which

Joseph J. Jasper

1972-01-01

354

Hyphenated Compounds in West German Newspapers.  

ERIC Educational Resources Information Center

Investigates the types of hyphenated compound nouns (which fill the need for naming new things and expressing new ideas) found in German newspapers and journals. Observes in what particular types of compounds the hyphen is most frequently used and why there is an upsurge in their use. (SED)

Delisle, Helga H.

1985-01-01

355

Heterogeneous photocatalytic reactions of sulfur aromatic compounds.  

PubMed

Sulfur aromatic compounds, such as mono-, di-, tri-, and tetraalkyl-substituted thiophene, benzothiophenes, dibenzothiophenes, are the molecular components of many fossils (petroleum, oil shale, tar sands, bitumen). Structural units of natural, cross-linked heteroaromatic polymers present in brown coals, turf, and soil are similar to those of sulfur aromatic compounds. Many sulfur aromatic compounds are found in the streams of petroleum refining and upgrading (naphthas, gas oils) and in the consumer products (gasoline, diesel, jet fuels, heating fuels). Besides fossils, the structural fragments of sulfur aromatic compounds are present in molecules of certain organic semiconductors, pesticides, small molecule drugs, and in certain biomolecules present in human body (pheomelanin pigments). Photocatalysis is the frontier area of physical chemistry that studies chemical reactions initiated by absorption of photons by photocatalysts, that is, upon electronic rather than thermal activation, under "green" ambient conditions. This review provides systematization and critical review of the fundamental chemical and physicochemical information on heterogeneous photocatalysis of sulfur aromatic compounds accumulated in the last 20-30 years. Specifically, the following topics are covered: physicochemical properties of sulfur aromatic compounds, major classes of heterogeneous photocatalysts, mechanisms and reactive intermediates of photocatalytic reactions of sulfur aromatic compounds, and the selectivity of these reactions. Quantum chemical calculations of properties and structures of sulfur aromatic compounds, their reactive intermediates, and the structure of adsorption complexes formed on the surface of the photocatalysts are also discussed. PMID:21809426

Samokhvalov, Alexander

2011-11-18

356

Hybrid Compounding in New Zealand English  

ERIC Educational Resources Information Center

This study investigates hybrid compound formation of Maori and English terms in present day New Zealand English (NZE). On the background of Maori and English language contact, the phenomenon of hybrid compounding emerges as a process that, on the one hand, symbolizes the vitality of the Maori element in NZE and, on the other hand, marks the…

Degani, Marta; Onysko, Alexander

2010-01-01

357

Volatile organic compounds of Schenella pityophilus.  

PubMed

Volatile organic compounds of Schenella pityophilus have been identified via solid-phase microextraction-gas chromatography-mass spectrometry analysis. Ten compounds have been identified, in which 3-methylthio-1-propene was the most significant component. Some other components were previously identified in Tuber aestivum and Tuber melanosporum. PMID:22236093

D'Auria, Maurizio; Racioppi, Rocco; Rana, Gian Luigi

2013-01-01

358

DIRECT MEASUREMENT OF ADSORPTION OF RADIOLABELED COMPOUNDS  

Microsoft Academic Search

A new apparatus and technique permit direct and continuous measurement ; of radiolabeled compounds adsorbed from solution onto clean solid surfaces. Thin ; films of metals are deposited under high vacuum onto the surface of a mica window ; and contacted with the solution containing the radiolabeled compound; adsorption ; is measured by a counter tube below the window. Clean

D. C. Walker; H. E. Jr. Ries

1962-01-01

359

Herbal Compounds and Toxins Modulating TRP Channels  

PubMed Central

Although the benefits are sometimes obvious, traditional or herbal medicine is regarded with skepticism, because the mechanism through which plant compounds exert their powers are largely elusive. Recent studies have shown however that many of these plant compounds interact with specific ion channels and thereby modulate the sensing mechanism of the human body. Especially members of the Transient Receptor Potential (TRP) channels have drawn large attention lately as the receptors for plant-derived compounds such as capsaicin and menthol. TRP channels constitute a large and diverse family of channel proteins that can serve as versatile sensors that allow individual cells and entire organisms to detect changes in their environment. For this family, a striking number of empirical views have turned into mechanism-based actions of natural compounds. In this review we will give an overview of herbal compounds and toxins, which modulate TRP channels. PMID:19305789

Vriens, Joris; Nilius, Bernd; Vennekens, Rudi

2008-01-01

360

Water-soluble constituents of caraway: aromatic compound, aromatic compound glucoside and glucides  

Microsoft Academic Search

From the water-soluble portion of the methanolic extract of caraway (fruit of Carum carvi L.), an aromatic compound, an aromatic compound glucoside and a glucide were isolated together with 16 known compounds. Their structures were clarified as 2-methoxy-2-(4?-hydroxyphenyl)ethanol, junipediol A 2-O-?-d-glucopyranoside and l-fucitol, respectively.

Tetsuko Matsumura; Toru Ishikawa; Junichi Kitajima

2002-01-01

361

Water-soluble constituents of caraway: aromatic compound, aromatic compound glucoside and glucides.  

PubMed

From the water-soluble portion of the methanolic extract of caraway (fruit of Carum carvi L.), an aromatic compound, an aromatic compound glucoside and a glucide were isolated together with 16 known compounds. Their structures were clarified as 2-methoxy-2-(4'-hydroxyphenyl)ethanol, junipediol A 2-O-beta-D-glucopyranoside and L-fucitol, respectively. PMID:12377243

Matsumura, Tetsuko; Ishikawa, Toru; Kitajima, Junichi

2002-10-01

362

Thiophenic Sulfur Compounds Released During Coal Pyrolysis.  

PubMed

Thiophenic sulfur compounds are released during coal gasification, carbonization, and combustion. Previous studies indicate that thiophenic sulfur compounds degrade very slowly in the environment, and are more carcinogenic than polycyclic aromatic hydrocarbons and nitrogenous compounds. Therefore, it is very important to study the principle of thiophenic sulfur compounds during coal conversion, in order to control their emission and promote clean coal utilization. To realize this goal and understand the formation mechanism of thiophenic sulfur compounds, this study focused on the release behavior of thiophenic sulfur compounds during coal pyrolysis, which is an important phase for all coal thermal conversion processes. The pyrolyzer (CDS-5250) and gas chromatography-mass spectrometry (Focus GC-DSQII) were used to analyze thiophenic sulfur compounds in situ. Several coals with different coal ranks and sulfur contents were chosen as experimental samples, and thiophenic sulfur compounds of the gas produced during pyrolysis under different temperatures and heating rates were investigated. Levels of benzothiophene and dibenzothiophene were obtained during pyrolysis at temperatures ranging from 200°C to 1300°C, and heating rates ranging from 6°C/ms to 14°C/ms and 6°C/s to 14°C/s. Moreover, the relationship between the total amount of benzothiophene and dibenzothiophene released during coal pyrolysis and the organic sulfur content in coal was also discussed. This study is beneficial for understanding the formation and control of thiophenic sulfur compounds, since it provides a series of significant results that show the impact that operation conditions and organic sulfur content in coal have on the amount and species of thiophenic sulfur compounds produced during coal pyrolysis. PMID:23781126

Xing, Mengwen; Kong, Jiao; Dong, Jie; Jiao, Haili; Li, Fan

2013-06-01

363

Compound estimation procedures in reliability  

NASA Technical Reports Server (NTRS)

At NASA, components and subsystems of components in the Space Shuttle and Space Station generally go through a number of redesign stages. While data on failures for various design stages are sometimes available, the classical procedures for evaluating reliability only utilize the failure data on the present design stage of the component or subsystem. Often, few or no failures have been recorded on the present design stage. Previously, Bayesian estimators for the reliability of a single component, conditioned on the failure data for the present design, were developed. These new estimators permit NASA to evaluate the reliability, even when few or no failures have been recorded. Point estimates for the latter evaluation were not possible with the classical procedures. Since different design stages of a component (or subsystem) generally have a good deal in common, the development of new statistical procedures for evaluating the reliability, which consider the entire failure record for all design stages, has great intuitive appeal. A typical subsystem consists of a number of different components and each component has evolved through a number of redesign stages. The present investigations considered compound estimation procedures and related models. Such models permit the statistical consideration of all design stages of each component and thus incorporate all the available failure data to obtain estimates for the reliability of the present version of the component (or subsystem). A number of models were considered to estimate the reliability of a component conditioned on its total failure history from two design stages. It was determined that reliability estimators for the present design stage, conditioned on the complete failure history for two design stages have lower risk than the corresponding estimators conditioned only on the most recent design failure data. Several models were explored and preliminary models involving bivariate Poisson distribution and the Consael Process (a bivariate Poisson process) were developed. Possible short comings of the models are noted. An example is given to illustrate the procedures. These investigations are ongoing with the aim of developing estimators that extend to components (and subsystems) with three or more design stages.

Barnes, Ron

1990-01-01

364

Seleno-compounds in garlic and onion.  

PubMed

Garlic (Allium sativum) and onion (Allium cepa) are widely known for their biological properties but are far from having revealed all of their secrets even if the compounds involved in the biological mechanisms, flavenols, sulphur and seleno compounds have been identified. The beneficial effect of garlic on health including protection against cardiovascular diseases and cancers results from all of these compounds although their individual involvement is complex. Garlic and onion, broccoli, wild leek, have the ability to accumulate the selenium (Se) from soil. These Se-enriched plants present a greater protection against carcinogenesis than the common plants and two Se-compounds possessing anti-cancer activity have been identified: Se-methyl selenocysteine and gamma-glutamyl-Se-methyl selenocysteine. However, several Se-compounds from Se-enriched garlic or onion remain unidentified. The techniques for the detection of Se-species are numerous but few methods are able to identify the detected compounds. The very small quantities of Se-compounds present and the clear lack of standards do not make their analysis straightforward, particularly for non-enriched samples. Over the last 10 or so years development of the synthesis of Se-compounds and the use of GC-AED or EC/HPLC-ICP-MS have shown considerable possibilities. These techniques have allowed advances in the identification of Se-compounds, some of which are analogues of S-compounds in plants and yeasts. When these techniques are coupled to EC/HPLC-APCI-MS-MS, they provide a lot of information about the Se-biosynthesis in garlic. This has allowed the preferential formation of methylated compounds in Se-biochemistry to be identified, in contrast to the sulphur biochemistry of the Allium spp. in which compounds containing propenylic groups predominate. This review focuses on the recent advances in the analytical methods of Se-compounds in garlic and onion and particular attention is given to the biological properties of Se-species identified in Se-enriched plants. PMID:16480995

Arnault, Ingrid; Auger, Jacques

2006-04-21

365

Distributed imaging using compound eye sensors  

NASA Astrophysics Data System (ADS)

The capture of a wide field of view (FOV) scene by dividing it into multiple sub-images is a technique with many precedents in the natural world, the most familiar being the compound eyes of insects and arthropods. Artificial structures of networked cameras and simple compound eyes have been constructed for applications in robotics and machine vision. Previous work in this laboratory has explored the construction and calibration of sensors which produce multiple small images (of ~150 pixels in diameter) for high-speed object tracking. In this paper design options are presented for electronic compound eyes consisting of 101 - 103 identical 'eyelets'. To implement a compound eye, multiple sub-images can be captured by distributing cameras and/or image collection optics. Figures of merit for comparisons will be developed to illustrate the impact of design choices on the field of view, resolution, information rate, image processing, calibration, environmental sensitivity and compatibility with integrated CMOS imagers. Whereas compound eyes in nature are outward-looking, the methodology and subsystems for an outward-looking compound-eye sensor are similar for in an inward-looking sensor, although inward-looking sensors have a common region viewable to all eyelets simultaneously. The paper addresses the design considerations for compound eyes in both outward-looking and inward-looking configurations.

Carr, Peter K.; Ara, Farhana; Thomas, Paul J.; Hornsey, Richard I.

2004-10-01

366

Marine anticorrosion paints based on thiouracil compounds  

SciTech Connect

The inhibition of marine corrosion of steel by 6-amino-2-thiouracil (1) and its derivatives 6-benzylideneamino-2-thiouracil (2) and 6-p-chlorobenzylideneamino-2-thiouracil (3) has been tested on laboratory scale using electrochemical technique which was performed on mild steel in sea water medium and on field scale through the incorporation of the compounds individually in marine paints compositions. The paint containing the compounds were applied on unprimed steel and the coated panels were tested in Alexandria Eastern Harbour water (Egypt). The electrochemical measurements indicate that both compounds (1) & (3) act as cathodic-type inhibitors, but the data of compound (2) showed neither cathodic nor anodic inhibition. The paint composition based on the soluble resin material as a sole binder and containing compound (1) showed the best corrosion protection of its steel surface tell more than 2 months followed by the paint composition containing compound (3). On the other hand, oil is not recommended with paint composition containing these compounds.

Tadros, A.B.; Nabey, A.E. [National Inst. of Oceanog. & Fisheries, Alexendria (Egypt)

1996-10-01

367

Photoresolvable Compounds: Towards a Chiroptical - Crystalline Switch.  

NASA Astrophysics Data System (ADS)

The tendency for miniaturization in electronic devices has created the need for materials capable of high storage densities and high switching rates. There has been ample effort in bringing this miniaturization to the molecular level, i.e. the design of molecular switches. The possibility of using photons to address a switch at an specific site in a volume has motivated research in photoresponsive compounds. An interesting family of photoresponsive compounds are those that are sensitive to the sense of chirality of light. Compounds capable of photoresolution can be switched between a scalemic and a racemic state, this can be the basis for a chiroptical switch. Important parameters to control in the design of a photoresolvable compound are the optical properties that determine the degree of enantiomeric excess that one can attain at the photostationary state, the g value. Two strategies to increase the g value were investigated: exciton coupling and energy transfer. Energy transfer was shown to be an efficient strategy in the design of photoresolvable compounds. Specifically, a compound capable of generating a reversible enantiomeric excess of 0.4% has been design using this strategy. The implications of photoresolvable compounds in the creation of a chiroptical liquid crystalline switch are discussed.

Suarez, Mauricio

1995-11-01

368

Two-dimensional spatial compounding with warping.  

PubMed

Spatial compounding aims to improve image quality through signal averaging, but speed-of-sound (SoS) and refraction errors can misalign the component frames and blur the compound image. A 2-D compounding system is demonstrated that uses a nonrigid registration (warping) to realign the frames before compounding. Block-based estimates of local misalignments are interpolated smoothly to compute the warp vectors. Simulations and a specialized phantom, both with a 9% SoS distortion, were created, and compound images with and without warping were compared to the conventional image. Image sharpness was compared by measuring the diameter of point targets and directional edge sharpness. The average registration accuracy was 0.06 to 0.07 mm (approximately one pixel). The diameter of point targets increased only 2% with warping vs. 32% without warping and directional edge sharpness dropped 3.7% vs. 20.0%. Furthermore, most of the speckle reduction due to compounding is retained when warping is used. The tests on simulated and phantom data demonstrate that the method is capable of making a small, but significant, improvement to image quality. The examinations in vitro and in vivo show the correct operation of the method with real tissue features. Further clinical studies should be performed to compare spatial compounding with and without warping to see which applications would benefit from the small improvement. PMID:15313325

Groves, Adrian R; Rohling, Robert N

2004-07-01

369

Risk and liabilities of prescribing compounded medications.  

PubMed

Complications resulting from the use of compounded medications have become a troubling trend nationwide. There is a significant potential for patients to suffer serious harm from the use of substandard medications prepared by compounding pharmacies, and the reality of this problem has been demonstrated in several well-publicized incidences of serious medical complications, including patient deaths, that directly resulted from the use of medications prepared at compounding pharmacies. Unlike US Food and Drug Administration (FDA)-approved drugs, compounded products are not required to meet evidentiary standards for establishing safety and efficacy. Moreover, these products are not held to Good Manufacturing Practices, which require regular inspections, quality control testing, and rejection of material not meeting specifications. Physicians, as well as other prescribers, need to be aware that when a patient suffers harm from using a compounded medication, those injured patients may bring negligence and malpractice claims, not only against the pharmacy and the pharmacist responsible for preparing the medication, but also against the prescribing physician and the physician’s practice. Consequently, the best way for physicians to manage professional risk and avoid both litigation and potential negative patient outcomes related to compounded pharmaceuticals is to not use these products if there is an FDA-approved product available. However, if the use of a compounded medication is medically necessary, then physicians should adhere to the FDA guidance concerning traditional compounding. Moreover, it would be prudent for any physician who intends to either resell or participate in the distribution of compounded products beyond the direct treatment of their patients to consider obtaining the appropriate insurance coverage for this activity. PMID:25276868

Randell, Michael D; Duffy, Phillip J

2014-07-01

370

Application of bicyclic and cage compounds  

NASA Technical Reports Server (NTRS)

The results of a literature survey of the field of bicyclic and cage compounds were presented, with the objective of identifying those types of compounds with unusual physical and chemical stability, and determining what practical applications have been found for these compounds. Major applications have been as polymers, polymer additives, medicinals, and pesticides. Lesser applications have included fuels, fuel additives, lubricants, lubricant additives, and perfumes. Several areas where further work might be useful were also outlined; these are primarily in the areas of polymers, polymer additives, medicinals, and synthetic lubricants.

Clark, R. D.; Archuleta, B. S.

1976-01-01

371

Statistical thermodynamics of highly defective compounds  

SciTech Connect

A method aimed at extracting information, essentially formation and interaction energies of defects, from partial molar quantities of largely nonstoichiometric compounds, has been developed. Two quite different examples, a partially ionic compound, cerium dioxide, and a semimetal, titanium monoxide, have been considered. The method consists of calculating to a good approximation the partition function of a small system containing some tens of atoms, immersed in a large reservoir and representing the compound. Formation and interaction energies of defects are parameters adjusted from experimental data. The treatment of both short- and long-range interactions is discussed.

Boureau, G.; Tetot, R.

1989-08-01

372

Endocannabinoids, related compounds and their metabolic routes.  

PubMed

Endocannabinoids are lipid mediators able to bind to and activate cannabinoid receptors, the primary molecular targets responsible for the pharmacological effects of the ?9-tetrahydrocannabinol. These bioactive lipids belong mainly to two classes of compounds: N-acylethanolamines and acylesters, being N-arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG), respectively, their main representatives. During the last twenty years, an ever growing number of fatty acid derivatives (endocannabinoids and endocannabinoid-like compounds) have been discovered and their activities biological is the subject of intense investigations. Here, the most recent advances, from a therapeutic point of view, on endocannabinoids, related compounds, and their metabolic routes will be reviewed. PMID:25347455

Fezza, Filomena; Bari, Monica; Florio, Rita; Talamonti, Emanuela; Feole, Monica; Maccarrone, Mauro

2014-01-01

373

Two new compounds from Potentilla multicaulis Bunge.  

PubMed

Two new compounds (triterpenoid saponin and heterocyclic compound), 2?,3?, 19?,23,30-pentahydroxyurs-12-en-28-oic acid-28-O-?-d-glucopyranosyl ester (1) and N-hydroxyl-hexahydroazepin-2,4-diones (2), with 11 known compounds, picein (3), (7S,8R)-dihydrodehydrodiconiferyl alcohol-9'-O-?-d-glucopyranoside (4), (+)-1-hydroxy-2-epipinoresinol-1-?-d-glucoside (5), (+)-1-hydroxypinoresinol-1-?-d-glucoside (6), (+)-1-hydroxypinoresinol-4'-?-d-glucoside (7), schaftside (6-C-?-d-glucopyranosyl-8-C-?-l-arabinosyl apigenin) (8), isoschaftside (6-C-?-l-arabinosyl-8-C-?-d-glucopyranosyl apigenin) (9), isorhamnetin-3-O-?-d-glucopyranoside (10), quercetin-3-O-?-glucuronide (11), 8-O-methylherbacetin-3-O-sophoroside (12) and kaempferol (13), were isolated from Potentilla multicaulis Bunge. The structure of the compounds was elucidated by chemical and spectral evidence. PMID:23148512

Jia, Lingyun; Wang, Jing; Lv, Chongning; Xu, Tanye; He, Lihua; Dong, Yan; Lu, Jincai

2013-08-01

374

Refractory-metal compound impregnation of polytetrafluoroethylene  

NASA Technical Reports Server (NTRS)

Process impregnates polytetrafluoroethylene /PTFE/ with rhenium or molybdenum compounds. The refractory metals impregnated PTFE combines chemical inertness with electrical conductivity. They are useful for electro-chemical cells, chemical processing equipment, catalysts, electrostatic charge removal, RF gasketing, and cable shielding.

Leibecki, H. F.

1969-01-01

375

Botanical Compounds: Effects on Major Eye Diseases  

PubMed Central

Botanical compounds have been widely used throughout history as cures for various diseases and ailments. Many of these compounds exhibit strong antioxidative, anti-inflammatory, and antiapoptotic properties. These are also common damaging mechanisms apparent in several ocular diseases, including age-related macular degeneration (AMD), glaucoma, diabetic retinopathy, cataract, and retinitis pigmentosa. In recent years, there have been many epidemiological and clinical studies that have demonstrated the beneficial effects of plant-derived compounds, such as curcumin, lutein and zeaxanthin, danshen, ginseng, and many more, on these ocular pathologies. Studies in cell cultures and animal models showed promising results for their uses in eye diseases. While there are many apparent significant correlations, further investigation is needed to uncover the mechanistic pathways of these botanical compounds in order to reach widespread pharmaceutical use and provide noninvasive alternatives for prevention and treatments of the major eye diseases. PMID:23843879

Huynh, Tuan-Phat; Mann, Shivani N.; Mandal, Nawajes A.

2013-01-01

376

HEALTH EFFECTS ASSESSMENT FOR ANTIMONY AND COMPOUNDS  

EPA Science Inventory

The report summarizes and evaluates information relevant to a preliminary interim assessment of adverse health effects associated with specific chemicals or compounds. The Office of Emergency and Remedial Response (Superfund) uses these documents in preparing cost-benefit analyse...

377

ANALYSIS OF FISH HOMOGENATES FOR PERFLUORINATED COMPOUNDS  

EPA Science Inventory

Perfluorinated compounds (PFCs) which include PFOS and PFOA are widely distributed in wildlife. Whole fish homogenates were analyzed for PFCs from the upper Mississippi, the Missouri and the Ohio rivers. Methods development, validation data, and preliminary study results will b...

378

Thermodynamic Analysis of Ionic Compounds: Synthetic Applications.  

ERIC Educational Resources Information Center

Shows how thermodynamic cycles can be used to understand trends in heats of formation and aqueous solubilities and, most importantly, how they may be used to choose synthetic routes to new ionic compounds. (JN)

Yoder, Claude H.

1986-01-01

379

HEALTH EFFECTS ASSESSMENT FOR VANADIUM AND COMPOUNDS  

EPA Science Inventory

The report summarizes and evaluates information relevant to a preliminary interim assessment of adverse health effects associated with specific chemicals or compounds. The Office of Emergency and Remedial Response (Superfund) uses these documents in preparing cost-benefit analyse...

380

Reorganizations of complex networks: Compounding and reducing  

NASA Astrophysics Data System (ADS)

Real networks interact with each other by different kinds of topological connections, which are usually demonstrated by linking nodes of different networks. Simple connection, such as one-to-one corresponding, random connection and similar connection are adopted for studying the interacted networks. Practical interrelations established between the two networks are ignored. In this study, a generalized framework of multi-subnet composited complex network that allowed us to investigate interrelations among several subnets is developed. Based on that, reorganizations of networks: compounding (compound subnets into a "bigger" one) and reducing (obtain a "smaller" network from a "bigger" one) are proposed. As an empirical evidence, influence of compounding on traffic dynamics is discussed. And the properties of nodes linking two networks are also considered. Onset of compounding between two networks is revealed. Numerical simulations on artificial networks as well as real bus and tube networks of Qingdao in China agree well with our analysis, which show validity of our model.

Shao, Fengjing; Sui, Yi

2014-12-01

381

Cheap Natural Compound May Help Smokers Quit  

MedlinePLUS

... page, please enable JavaScript. Cheap Natural Compound May Help Smokers Quit But cytisine isn't widely available, ... been used in Eastern Europe for decades to help smokers quit, researchers say. But it's not widely ...

382

Microwave spectra of some volatile organic compounds  

NASA Technical Reports Server (NTRS)

A computer-controlled microwave (MRR) spectrometer was used to catalog reference spectra for chemical analysis. Tables of absorption frequency, peak absorption intensity, and integrated intensity are included for 26 volatile organic compounds, all but one of which contain oxygen.

White, W. F.

1975-01-01

383

Identification of Aneuploidy-Selective Antiproliferation Compounds  

E-print Network

Aneuploidy, an incorrect chromosome number, is a hallmark of cancer. Compounds that cause lethality in aneuploid, but not euploid, cells could therefore provide new cancer therapies. We have identified the energy stress-inducing ...

Tang, Yun-Chi

384

Techniques for analysis of plant phenolic compounds.  

PubMed

Phenolic compounds are well-known phytochemicals found in all plants. They consist of simple phenols, benzoic and cinnamic acid, coumarins, tannins, lignins, lignans and flavonoids. Substantial developments in research focused on the extraction, identification and quantification of phenolic compounds as medicinal and/or dietary molecules have occurred over the last 25 years. Organic solvent extraction is the main method used to extract phenolics. Chemical procedures are used to detect the presence of total phenolics, while spectrophotometric and chromatographic techniques are utilized to identify and quantify individual phenolic compounds. This review addresses the application of different methodologies utilized in the analysis of phenolic compounds in plant-based products, including recent technical developments in the quantification of phenolics. PMID:23429347

Khoddami, Ali; Wilkes, Meredith A; Roberts, Thomas H

2013-01-01

385

New twisted intermetallic compound superconductor: A concept  

NASA Technical Reports Server (NTRS)

Method for processing Nb3Sn and other intermetallic compound superconductors produces a twisted, stabilized wire or tube which can be used to wind electromagnetics, armatures, rotors, and field windings for motors and generators as well as other magnetic devices.

Coles, W. D.; Brown, G. V.; Laurence, J. C.

1972-01-01

386

A family of ductile intermetallic compounds.  

PubMed

Stoichiometric intermetallic compounds have always been touted for their attractive chemical, physical, electrical, magnetic and mechanical properties, but few practical uses have materialized because they are brittle at room temperature. Here we report on a large family of fully ordered, stoichiometric binary rare-earth intermetallic compounds with high ductility at room temperature. Although conventional wisdom calls for special conditions, such as non-stoichiometry, metastable disorder or doping to achieve some ductility in intermetallic compounds at room temperature, none of these is required in these unique B2 rare-earth compounds. Ab initio calculations of YAg, YCu and NiAl crystal defect energies support the observed deformation modes of these intermetallics. PMID:12942069

Gschneidner, Karl; Russell, Alan; Pecharsky, Alexandra; Morris, James; Zhang, Zhehua; Lograsso, Thomas; Hsu, David; Lo, C H Chester; Ye, Yiying; Slager, Aaron; Kesse, David

2003-09-01

387

Food applications of natural antimicrobial compounds  

PubMed Central

In agreement with the current trend of giving value to natural and renewable resources, the use of natural antimicrobial compounds, particularly in food and biomedical applications, becomes very frequent. The direct addition of natural compounds to food is the most common method of application, even if numerous efforts have been made to find alternative solutions to the aim of avoiding undesirable inactivation. Dipping, spraying, and coating treatment of food with active solutions are currently applied to product prior to packaging as valid options. The aim of the current work is to give an overview on the use of natural compounds in food sector. In particular, the review will gather numerous case-studies of meat, fish, dairy products, minimally processed fruit and vegetables, and cereal-based products where these compounds found application. PMID:23060862

Lucera, Annalisa; Costa, Cristina; Conte, Amalia; Del Nobile, Matteo A.

2012-01-01

388

Production method for making rare earth compounds  

DOEpatents

A method of making a rare earth compound, such as a earth-transition metal permanent magnet compound, without the need for producing rare earth metal as a process step, comprises carbothermically reacting a rare earth oxide to form a rare earth carbide and heating the rare earth carbide, a compound-forming reactant (e.g. a transition metal and optional boron), and a carbide-forming element (e.g. a refractory metal) that forms a carbide that is more thermodynamically favorable than the rare earth carbide whereby the rare earth compound (e.g. Nd.sub.2 Fe.sub.14 B or LaNi.sub.5) and a carbide of the carbide-forming element are formed.

McCallum, R. William (Ames, IA); Ellis, Timothy W. (Ames, IA); Dennis, Kevin W. (Ames, IA); Hofer, Robert J. (Ames, IA); Branagan, Daniel J. (Ames, IA)

1997-11-25

389

Digital Construction Platform: A Compound Arm Approach  

E-print Network

We introduce a novel large-scale Digital Construction Platform (DCP) for on-site sensing, analysis, and fabrication. The DCP is an in-progress research project consisting of a compound robotic arm system comprised of a ...

Spielberg, Nathan A.

2014-01-01

390

Perfluorinated Compounds In The Ohio River Basin  

EPA Science Inventory

Contaminants of emerging concern (CECs) in waterways include pharmaceuticals and personal care products (PPCPs), alkylphenols, endocrine disrupting chemicals (EDCs) and perfluorinated alkyl compounds (PFCs). Their distributions and persistence in the aquatic environment remain p...

391

BEHAVIORAL TOXICITY OF TRIALKYLTIN COMPOUNDS: A REVIEW  

EPA Science Inventory

Triethyltin (TET) and trimethyltin (TMT) are neurotoxic organotin compounds which produce different patterns of toxicity in adult animals. Exposure to TET produces behavioral toxicity (decreased motor activity, grip strength, operant response rate and startle response amplitude) ...

392

Stress-Induced Enzyme Compounds Methamphetamine Neurotoxicity  

MedlinePLUS

... They implicate ketoprofen’s main target, the pro-inflammatory enzyme cyclooxygenase (COX-1/COX-2), in the stress- ... citation National Institute on Drug Abuse. Stress-Induced Enzyme Compounds Methamphetamine Neurotoxicity Retrieved from http://www.drugabuse. ...

393

Aza crown ether compounds as anion receptors  

DOEpatents

A family of aza-ether based compounds including linear, multi-branched and aza-crown ethers is provided. When added to non-aqueous battery electrolytes, the new family of aza-ether based compounds acts as neutral receptors to complex the anion moiety of the electrolyte salt thereby increasing the conductivity and the transference number of LI{sup +} ion in alkali metal batteries. 3 figs.

Lee, H.S.; Yang, X.O.; McBreen, J.

1998-08-04

394

Aza crown ether compounds as anion receptors  

DOEpatents

A family of aza-ether based compounds including linear, multi-branched and aza-crown ethers is provided. When added to non-aqueous battery electrolytes, the new family of aza-ether based compounds acts as neutral receptors to complex the anion moiety of the electrolyte salt thereby increasing the conductivity and the transference number of LI.sup.+ ion in alkali metal batteries.

Lee, Hung Sui (East Setauket, NY); Yang, Xiao-Oing (Port Jefferson Station, NY); McBreen, James (Bellport, NY)

1998-08-04

395

Medical Applications and Toxicities of Gallium Compounds  

PubMed Central

Over the past two to three decades, gallium compounds have gained importance in the fields of medicine and electronics. In clinical medicine, radioactive gallium and stable gallium nitrate are used as diagnostic and therapeutic agents in cancer and disorders of calcium and bone metabolism. In addition, gallium compounds have displayed anti-inflammatory and immunosuppressive activity in animal models of human disease while more recent studies have shown that gallium compounds may function as antimicrobial agents against certain pathogens. In a totally different realm, the chemical properties of gallium arsenide have led to its use in the semiconductor industry. Gallium compounds, whether used medically or in the electronics field, have toxicities. Patients receiving gallium nitrate for the treatment of various diseases may benefit from such therapy, but knowledge of the therapeutic index of this drug is necessary to avoid clinical toxicities. Animals exposed to gallium arsenide display toxicities in certain organ systems suggesting that environmental risks may exist for individuals exposed to this compound in the workplace. Although the arsenic moiety of gallium arsenide appears to be mainly responsible for its pulmonary toxicity, gallium may contribute to some of the detrimental effects in other organs. The use of older and newer gallium compounds in clinical medicine may be advanced by a better understanding of their mechanisms of action, drug resistance, pharmacology, and side-effects. This review will discuss the medical applications of gallium and its mechanisms of action, the newer gallium compounds and future directions for development, and the toxicities of gallium compounds in current use. PMID:20623028

Chitambar, Christopher R.

2010-01-01

396

Bioremediation and phytoremediation: Chlorinated and recalcitrant compounds  

SciTech Connect

Bioremediation and phytoremediation have progressed, especially with regard to the treatment of hydrocarbon-contaminated sites. Sites contaminated with chlorinated and recalcitrant compounds have proven more resistant to these approaches, but exciting progress is being made both in the laboratory and in the field. This book brings together the latest breakthrough thinking and results in bioremediation, with chapters on cometabolic processes, aerobic and anaerobic mechanisms, biological reductive dechlorination processes, bioaugmentation, biomonitoring, and phytoremediation of recalcitrant organic compounds.

NONE

1998-12-31

397

Superconductivity of Technetium Alloys and Compounds  

Microsoft Academic Search

The superconducting transition temperatures of Mo-Tc alloys are reported. Critical field measurements of a 50 atomic percent alloy indicate that it might be a promising material for superconducting magnets. The similarity of Tc and Re with respect to alloy and intermetallic compound formation is noted. The superconducting transition temperatures of the compounds ZrTc6 and NbTc3 are 9.7°K and 10.5°K, respectively.

V. B. Compton; E. Corenzwit; J. P. Maita; B. T. Matthias; F. J. Morin

1961-01-01

398

Organic compounds passage through RO membranes  

Microsoft Academic Search

Organic solute permeation, sorption, and rejection by reverse osmosis membranes, from aqueous solutions, were studied experimentally and via artificial neural networks (ANN)-based quantitative structure–property relations (QSPR), for a set of fifty organic compounds for polyamide and cellulose acetate membranes. Membrane solute sorption and passage for dead-end filtration model experiments were quantified based on radioactivity measurements for radiolabeled compounds in the

Dan Libotean; Jaume Giralt; Robert Rallo; Yoram Cohen; Francesc Giralt; Harry F. Ridgway; Grisel Rodriguez; Don Phipps

2008-01-01

399

Green Tea Polyphenolic Compounds and Human Health  

Microsoft Academic Search

:  Polyphenols are a structurally diverse group of compounds that occur widely throughout the plant kingdom. Polyphenolic compounds\\u000a are ubiquitous in all plant organs and are, therefore, an integral part of the human diet. Recent interest in food phenolics\\u000a has increased greatly because of the antioxidant and free radical-scavenging abilities associated with some phenolics and\\u000a their potential effects on human health.

D. S. Barbosa; Décio Sabbatini

2007-01-01

400

[Genotoxic properties of 5-nitrofuran compounds].  

PubMed

5-nitrofurans are a large group of nitro-compounds and worldwide as human and veterinary drugs, food additives or preservatives. However, many adverse effects of these compounds and among mutagenic as well as carcinogenic activities create doubts about safety of their use. Present paper deals with various mechanisms of genotoxic action of 5-nitrofurans. Main metabolic pathways leading to the formation of their active metabolites are discussed. PMID:8619121

Szczypka, M

1995-01-01

401

Excitonic effects in oxyhalide scintillating host compounds  

NASA Astrophysics Data System (ADS)

Ab-initio calculations based on density functional theory have been performed to study the electronic, optical, mechanical, and vibrational properties of scintillator host compounds YOX (X = F, Cl, Br, and I). Semiempirical dispersion correction schemes are used to find the effect of van der Waals forces on these layered compounds and we found this effect to be negligible except for YOBr. Calculations of phonons and elastic constants showed that all the compounds studied here are both dynamically and mechanically stable. YOF and YOI are found to be indirect band gap insulators while YOCl and YOBr are direct band gap insulators. The band gap is found to decrease as we move from fluorine to iodine, while the calculated refractive index shows the opposite trend. As the band gap decreases on going down the periodic table from YOF to YOI, the luminescence increases. The excitonic binding energy calculated, within the effective mass approximation, is found to be more for YOF than the remaining compounds, suggesting that the excitonic effect to be more in YOF than the other compounds. The optical properties are calculated within the Time-Dependent Density Functional Theory (TDDFT) and compared with results obtained within the random phase approximation. The TDDFT calculations, using the newly developed bootstrap exchange-correlation kernel, showed significant excitonic effects in all the compounds studied here.

Shwetha, G.; Kanchana, V.; Valsakumar, M. C.

2014-10-01

402

Excitonic effects in oxyhalide scintillating host compounds  

SciTech Connect

Ab-initio calculations based on density functional theory have been performed to study the electronic, optical, mechanical, and vibrational properties of scintillator host compounds YOX (X?=?F, Cl, Br, and I). Semiempirical dispersion correction schemes are used to find the effect of van der Waals forces on these layered compounds and we found this effect to be negligible except for YOBr. Calculations of phonons and elastic constants showed that all the compounds studied here are both dynamically and mechanically stable. YOF and YOI are found to be indirect band gap insulators while YOCl and YOBr are direct band gap insulators. The band gap is found to decrease as we move from fluorine to iodine, while the calculated refractive index shows the opposite trend. As the band gap decreases on going down the periodic table from YOF to YOI, the luminescence increases. The excitonic binding energy calculated, within the effective mass approximation, is found to be more for YOF than the remaining compounds, suggesting that the excitonic effect to be more in YOF than the other compounds. The optical properties are calculated within the Time-Dependent Density Functional Theory (TDDFT) and compared with results obtained within the random phase approximation. The TDDFT calculations, using the newly developed bootstrap exchange-correlation kernel, showed significant excitonic effects in all the compounds studied here.

Shwetha, G.; Kanchana, V., E-mail: kanchana@iith.ac.in [Department of Physics, Indian Institute of Technology Hyderabad, Ordnance Factory Estate, Yeddumailaram 502 205, Telangana (India); Valsakumar, M. C. [School of Engineering Sciences and Technology (SEST), University of Hyderabad, Prof. C. R. Rao Road, Gachibowli, Hyderabad 500 046, Telangana (India)

2014-10-07

403

Carbonyl Compounds Generated from Electronic Cigarettes  

PubMed Central

Electronic cigarettes (e-cigarettes) are advertised as being safer than tobacco cigarettes products as the chemical compounds inhaled from e-cigarettes are believed to be fewer and less toxic than those from tobacco cigarettes. Therefore, continuous careful monitoring and risk management of e-cigarettes should be implemented, with the aim of protecting and promoting public health worldwide. Moreover, basic scientific data are required for the regulation of e-cigarette. To date, there have been reports of many hazardous chemical compounds generated from e-cigarettes, particularly carbonyl compounds such as formaldehyde, acetaldehyde, acrolein, and glyoxal, which are often found in e-cigarette aerosols. These carbonyl compounds are incidentally generated by the oxidation of e-liquid (liquid in e-cigarette; glycerol and glycols) when the liquid comes in contact with the heated nichrome wire. The compositions and concentrations of these compounds vary depending on the type of e-liquid and the battery voltage. In some cases, extremely high concentrations of these carbonyl compounds are generated, and may contribute to various health effects. Suppliers, risk management organizations, and users of e-cigarettes should be aware of this phenomenon. PMID:25353061

Bekki, Kanae; Uchiyama, Shigehisa; Ohta, Kazushi; Inaba, Yohei; Nakagome, Hideki; Kunugita, Naoki

2014-01-01

404

[Calorimetric evaluation of directly compressed tablets].  

PubMed

The paper studies the effect of the type of the disintegrating substance and the lubricant on the destruction heat of tablet materials and tablets. Destruction heat was determined by means of isoperibolic calorimetry. Tablet materials and tablets contained Avicel PH 101 as the dry binder, 10% of Primojel, Ac-Di-Sol, or Polyplasdone XL as disintegrating substances, and 5% of magnesium strearate or sodium laurylsulfate as the lubricants. The sum of destruction heats of the individual auxiliary substances equalled the found values in tablet materials and tablets. In tablets, in contrast to tablet materials, values of destruction heat higher by 57.9% were found. In the disintegrating substances and lubricants tested, the found values of destruction heats were dependent on the values of destruction heats of the individual auxiliary substances. In the disintegrating substances, a linear dependence of the total destruction heat (CDT) on the destruction heat of the disintegrating substances (DTR) was found, given by the relationship CDT = 0.797.DTR + 17.666 with the correlation coefficient r = 0.986. PMID:11242832

Rehula, M; Lavická, J; Musilová, M

2001-01-01

405

Laser power precise measurement using calorimetric method  

Microsoft Academic Search

A new double calorimeter designed in order to establish the continuous-wave laser power mesurement standard is described. The double calorimeter consists of a standard thermopile unit with fast response and an electronic cooling calorimeter whose thermal load is borne by the thermopile unit. The characteristics of the two units are studied in detail. Various errors related to determining the effective

T. Honda

1983-01-01

406

Calorimetric measurement of energy of ultrasonic cleaners  

SciTech Connect

The development of a calorimeter that measured the power within an ultrasonic cleaning tank is presented. The principle involved is explained. Several types of calorimeter that were tested are described. Measurement of the power in an ultrasonic cleaner permits: (1) comparing different ultrasonic cleaners; (2) monitoring the performance of a specific cleaner; (3) measuring the distribution of power in a cleaning tank, and (4) evaluating the effects of process variables on the power.

Harding, W.B.

1994-11-01

407

40 CFR 721.655 - Ethoxylated alkyl quaternary ammonium compound.  

Code of Federal Regulations, 2010 CFR

... false Ethoxylated alkyl quaternary ammonium compound. 721.655 Section 721...655 Ethoxylated alkyl quaternary ammonium compound. (a) Chemical substance...generically as an ethoxylated alkyl quaternary ammonium compound (PMN P-96-573) is...

2010-07-01

408

Noun Compound Interpretation Using Paraphrasing Verbs: Feasibility Study  

E-print Network

an important challenge for the auto- matic processing of English written text: understanding noun compounds words: Noun Compounds, Lexical Semantics, Paraphrasing. Part of this research was performed whileNoun Compound Interpretation Using Paraphrasing Verbs: Feasibility Study Preslav Nakov Linguistic

Hearst, Marti

409

40 CFR 721.10618 - Polyaromatic organophosphorus compound (generic).  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Polyaromatic organophosphorus compound (generic). 721.10618...Substances § 721.10618 Polyaromatic organophosphorus compound (generic). (a...identified generically as polyaromatic organophosphorus compound (PMN...

2014-07-01

410

40 CFR 721.10618 - Polyaromatic organophosphorus compound (generic).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Polyaromatic organophosphorus compound (generic). 721.10618...Substances § 721.10618 Polyaromatic organophosphorus compound (generic). (a...identified generically as polyaromatic organophosphorus compound (PMN...

2013-07-01

411

40 CFR 721.655 - Ethoxylated alkyl quaternary ammonium compound.  

Code of Federal Regulations, 2011 CFR

...Ethoxylated alkyl quaternary ammonium compound. 721.655 Section 721.655 ...Ethoxylated alkyl quaternary ammonium compound. (a) Chemical substance and significant...ethoxylated alkyl quaternary ammonium compound (PMN P-96-573) is subject...

2011-07-01

412

46 CFR 151.50-6 - Motor fuel antiknock compounds.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Motor fuel antiknock compounds. 151.50-6 Section 151.50-6... § 151.50-6 Motor fuel antiknock compounds. When transporting motor fuel antiknock compounds containing tetraethyl lead and...

2010-10-01

413

27 CFR 27.43 - Liqueurs, cordials, and similar compounds.  

Code of Federal Regulations, 2011 CFR

... Liqueurs, cordials, and similar compounds. 27.43 Section 27.43 Alcohol... Liqueurs, Cordials, and Other Compounds and Preparations § 27.43 Liqueurs, cordials, and similar compounds. A tax is imposed by 26...

2011-04-01

414

46 CFR 151.50-6 - Motor fuel antiknock compounds.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Motor fuel antiknock compounds. 151.50-6 Section 151.50-6... § 151.50-6 Motor fuel antiknock compounds. When transporting motor fuel antiknock compounds containing tetraethyl lead and...

2011-10-01

415

40 CFR 721.10124 - Brominated polyaromatic compound (generic).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Brominated polyaromatic compound (generic). 721.10124 Section...721.10124 Brominated polyaromatic compound (generic). (a) Chemical substance...generically as brominated polyaromatic compound (PMN P-06-617) is subject...

2010-07-01

416

27 CFR 27.43 - Liqueurs, cordials, and similar compounds.  

Code of Federal Regulations, 2010 CFR

... Liqueurs, cordials, and similar compounds. 27.43 Section 27.43 Alcohol... Liqueurs, Cordials, and Other Compounds and Preparations § 27.43 Liqueurs, cordials, and similar compounds. A tax is imposed by 26...

2010-04-01

417

40 CFR 721.5980 - Dialkyl phosphorodithioate phosphate compounds.  

Code of Federal Regulations, 2011 CFR

... Dialkyl phosphorodithioate phosphate compounds. 721.5980 Section 721.5980... Dialkyl phosphorodithioate phosphate compounds. (a) Chemical substance and significant...as dialkyl phosphorodithioate phosphate compounds (P-90-1642 through 1649)...

2011-07-01

418

40 CFR 721.5250 - Trimethyl spiropolyheterocyclic naphthalene compound.  

Code of Federal Regulations, 2011 CFR

...Trimethyl spiropolyheterocyclic naphthalene compound. 721.5250 Section 721.5250...Trimethyl spiropolyheterocyclic naphthalene compound. (a) Chemical substance and significant...spir-o-poly-het-er-o-cyc-lic naphthalene compound (PMN P-91-1456) is subject...

2011-07-01

419

40 CFR 721.5250 - Trimethyl spiropolyheterocyclic naphthalene compound.  

Code of Federal Regulations, 2010 CFR

...Trimethyl spiropolyheterocyclic naphthalene compound. 721.5250 Section 721.5250...Trimethyl spiropolyheterocyclic naphthalene compound. (a) Chemical substance and significant...spir-o-poly-het-er-o-cyc-lic naphthalene compound (PMN P-91-1456) is subject...

2010-07-01

420

40 CFR 721.10124 - Brominated polyaromatic compound (generic).  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Brominated polyaromatic compound (generic). 721.10124 Section...721.10124 Brominated polyaromatic compound (generic). (a) Chemical substance...generically as brominated polyaromatic compound (PMN P-06-617) is subject...

2011-07-01

421

Biodegradation of Aromatic Compounds by Escherichia coli  

PubMed Central

Although Escherichia coli has long been recognized as the best-understood living organism, little was known about its abilities to use aromatic compounds as sole carbon and energy sources. This review gives an extensive overview of the current knowledge of the catabolism of aromatic compounds by E. coli. After giving a general overview of the aromatic compounds that E. coli strains encounter and mineralize in the different habitats that they colonize, we provide an up-to-date status report on the genes and proteins involved in the catabolism of such compounds, namely, several aromatic acids (phenylacetic acid, 3- and 4-hydroxyphenylacetic acid, phenylpropionic acid, 3-hydroxyphenylpropionic acid, and 3-hydroxycinnamic acid) and amines (phenylethylamine, tyramine, and dopamine). Other enzymatic activities acting on aromatic compounds in E. coli are also reviewed and evaluated. The review also reflects the present impact of genomic research and how the analysis of the whole E. coli genome reveals novel aromatic catabolic functions. Moreover, evolutionary considerations derived from sequence comparisons between the aromatic catabolic clusters of E. coli and homologous clusters from an increasing number of bacteria are also discussed. The recent progress in the understanding of the fundamentals that govern the degradation of aromatic compounds in E. coli makes this bacterium a very useful model system to decipher biochemical, genetic, evolutionary, and ecological aspects of the catabolism of such compounds. In the last part of the review, we discuss strategies and concepts to metabolically engineer E. coli to suit specific needs for biodegradation and biotransformation of aromatics and we provide several examples based on selected studies. Finally, conclusions derived from this review may serve as a lead for future research and applications. PMID:11729263

Díaz, Eduardo; Ferrández, Abel; Prieto, María A.; García, José L.

2001-01-01

422

[Chemotherapeutic effects of nitro compounds. 1. Nitroanilines].  

PubMed

More than 200 nitro compounds, most of them nitroaniline derivatives substituted with one or more radicals having a basic reaction, were prepared and investigated as to their therapeutic activity against bacteria, fungi, protozoa, helminths, viruses and tumors. Several mono-nitrobenzenes with a radical having a basic reaction showed weak in-vitro activity against gram-positive bacteria and against Crocker's sarcoma 180; they also showed systemic activity against nematodes (Aspiculuris tetraptera) and viruses. The majority of therapeutically active compounds with pronounced in-vivo activity against Trichomonas fetus, Entamoeba histolytica, Schistosoma mansoni, cestodes, nematodes (Ancylostoma caninum), viruses (influenza, MHV, SAV and EMC) and various types of carcinoma (Ehrlich's carcinoma, leukemia 1210, Crocker's sarcoma 180) were dinitrobenzene derivatives with one radical having a basic reaction and electropositive groups or unreactive or reactive chlorine atom, and di-nitrobenzene with two equal or two different radicals having a basic reaction. Compound No. 70 revealed a marked in-vitro activity against fungi (Trichophyton; Microsporum, Candida albicans). Other nitro compounds such as bis-mono- and bis-dinitrobenzene derivatives likewise showed a systemic action against E. histolytica, viruses and, in particular, carcinoma (Crocker's sarcoma 180, Ridgway's osteosarcoma). Oxygen and sulfur analogue compounds as well as compounds produced by reduction also possessed a distinct activity against E. histolytica and viruses. On the basis of the present results particularly the dinitrobenzenes substituted with two radicals having a basic reaction include a number which have in common that a structure/activity relationship is recognizable in respect of E. histolytica, Schistosoma mansoni and different types of viruses. The activity against viruses in this class of compounds is probably due to an increased interferon production in the host animal. Whether the mechanism of action is the same against E. histolytica or Schistosoma mansoni has not been determined so far. A tumorigenic effect was observed mainly in those di-nitrobenzenes which are classed as alkylating compounds. Because of the small chemotherapeutic index the trials were not continued with the most effective compounds mentioned. PMID:1242309

Winkelmann, V E; Raether, W; Dittmar, W; Düwel, D; Gericke, D; Hohorst, W; Rolly, H; Schrinner, W; Wagner, W H

1975-05-01

423

Spectroscopic and calorimetric investigation of short and intermediate-range structures and energetics of amorphous SiCO, SiCN, and SiBCN polymer-derived ceramics  

NASA Astrophysics Data System (ADS)

Polymer-derived ceramics (PDCs) are a new class of amorphous ceramics in the Si-B-C-N system that are synthesized by the pyrolysis of silicon-based organic polymers. PDCs are lightweight and are resistant to creep, crystallization, and oxidation at temperatures near 1800 K making them ideal for a variety of high temperature applications. In spite of being X-ray amorphous, these materials display structural heterogeneity at the nanometer length scale. Their structure and resulting properties can be drastically altered by the utilization of preceramic polymers with differing chemistry and architectures. Fundamental understanding of the atomic structure is critical in deciphering the structure-property relationships and ultimately in controlling their properties for specific engineering applications. The short-range atomic structure has been extensively investigated using a variety of techniques, however, the structures at length scales beyond next-nearest neighbors remained highly controversial. Here we report the results of a spectroscopic and calorimetric study of short and intermediate -range structure and energetic of SiOC and SiBCN PDCs derived from a wide variety of precursors. SiOC PDCs with different carbon contents were synthesized from polysiloxane precurors and their structures were studied using high-resolution 13C and 29Si nuclear magnetic resonance (NMR) spectroscopy. The results suggest that these PDCs consists of a continuous mass fractal backbone of corner-shared SiC xO4-x tetrahedral units with "voids" occupied by sp 2-hybridized graphitic carbon. The oxygen-rich SiCxO 4-x units are located at the interior of this backbone with a mass fractal dimension of ~ 2.5, while the carbon-rich units occupy the two-dimensional interface between the backbone and the free carbon nanodomains. Such fractal topology is expected to give rise to unusual mechanical and transport properties characteristic of fractal percolation networks. For example, elastic moduli and transport properties such as electrical conductivity and viscosity may show power-law dependence on composition near and above the percolation threshold of the SiOC network or that of the free-carbon phase. Si(B)CN PDCs with different carbon contents were synthesized by pyrolysis of poly(boro)silylcarbodiimides and poly(boro)silazane precursors and their structure and energetics were studied using multi-nuclear, one- and two- dimensional NMR spectroscopy and oxide melt solution calorimetry. The structure of the polysilylcarbodiimide-derived SiCN PDCs at lower carbon content and pyrolysis temperatures (800 oC) consists of amorphous nanodomains of sp2 carbon and silicon nitride with an interfacial bonding between N, C and Si atoms that is stabilized by the presence of hydrogen. The interfacial Si-C and N-C bonds are destroyed with concomitant hydrogen loss upon increasing the pyrolysis temperature to 1100 oC. Calorimetry results demonstrate that the mixed bonding in the interfacial regions play a key role in the thermodynamic stabilization of these PDCs. The size of the carbon domains increases with increasing carbon content until a continuous amorphous carbon matrix is formed with 55-60 wt % C. The polyborosilylcarbodiimide-derived SiBCN ceramics contain carbon and silicon nitride nanodomains with the BN domains being present predominantly at the interface. In contrast, the structure of the polyborosilazane-derived ceramics consists of significant amount of mixed bonding in the nearest-neighbor coordination environments of Si and B atoms leading to the formation of SiC xN4-x tetrahedral units and BCN2 triangular units. The interfacial region between the SiCN and C nanodomains is occupied by the BCN phase. These results demonstrate that the chemistry of the polymeric precursors exerts major influence on the microstructure and bonding in their derived ceramics.

Widgeon, Scarlett J.

424

Processing Novel and Lexicalized Finnish Compound Words.  

PubMed

Participants read sentences in which novel and lexicalized two-constituent compound words appeared while their eye movements were measured. The frequency of the first constituent of the compounds was also varied factorially and the frequency of the lexicalized compounds was equated over the two conditions. The sentence frames prior to the target word were matched across conditions. Both lexicality and first constituent frequency had large and significant effects on gaze durations on the target word; moreover the constituent frequency effect was significantly larger for the novel words. These results indicate that first constituent frequency has an effect in two stages: in the initial encoding of the compound and in the construction of meaning for the novel compound. The difference between this pattern of results and those for English prefixed words (Pollatsek, Slattery, & Juhasz, 2008) is apparently due to differences in the construction of meaning stage. A general model of the relationship of the processing of polymorphemic words to how they are fixated is presented. PMID:22518273

Pollatsek, Alexander; Bertram, Raymond; Hyönä, Jukka

2011-11-01

425

Potent acetylcholinesterase inhibitory compounds from Myristica fragrans.  

PubMed

The anti-cholinesterase activity was evaluated of the ethyl acetate fraction of the methanol extract of Myristica fragrans Houtt (Myristicaceae) seeds and of compounds isolated from it by various chromatographic techniques. The chemical structures of the compounds were determined from spectroscopic analyses (NMR data). Thirteen compounds (1-13) were isolated and identified. Compound 8 { [(7S)-8'-(4'-hydroxy-3'-methoxyphenyl)-7-hydroxypropyl]benzene-2,4-diol) showed the most effective activity with an IC50 value of 35.1 microM, followed by compounds 2 [(8R,8'S)-7'-(3',4'-methylenedioxyphenyl)-8,8'-dimethyl-7-(3,4-dihydroxyphenyl)-butane] and 11 (malabaricone C) with IC50 values of 42.1 and 44.0 pM, respectively. This is the first report of significant anticholinesterase properties of M. fragrans seeds. The findings demonstrate that M. fragrans could be used beneficially in the treatment of Alzheimer's disease. PMID:24868867

Cuong, To Dao; Hung, Tran Manh; Han, Hyoung Yun; Roh, Hang Sik; Seok, Ji-Hyeon; Lee, Jong Kwon; Jeong, Ja Young; Choi, Jae Sue; Kim, Jeong Ah; Min, Byung Sun

2014-04-01

426

Process for production of a borohydride compound  

DOEpatents

A process for production of a borohydride compound M(BH.sub.4).sub.y. The process has three steps. The first step combines a compound of formula (R.sup.1O).sub.yM with aluminum, hydrogen and a metallic catalyst containing at least one metal selected from the group consisting of titanium, zirconium, hafnium, niobium, vanadium, tantalum and iron to produce a compound of formula M(AlH.sub.3OR.sup.1).sub.y, wherein R.sup.1 is phenyl or phenyl substituted by at least one alkyl or alkoxy group; M is an alkali metal, Be or Mg; and y is one or two; wherein the catalyst is present at a level of at least 200 ppm based on weight of aluminum. The second step combines the compound of formula M(AlH.sub.3OR.sup.1).sub.y with a borate, boroxine or borazine compound to produce M(BH.sub.4).sub.y and a byproduct mixture containing alkali metal and aluminum aryloxides. The third step separates M(BH.sub.4).sub.y from the byproduct mixture.

Allen, Nathan Tait; Butterick, III, Robert; Chin, Arthur Achhing; Millar, Dean Michael; Molzahn, David Craig

2014-08-19

427

Determination of arsenic compounds in earthworms  

SciTech Connect

Earthworms and soil collected from six sites in Styria, Austria, were investigated for total arsenic concentrations by ICP-MS and for arsenic compounds by HPLC-ICP-MS. Total arsenic concentrations ranged from 3.2 to 17.9 mg/kg dry weight in the worms and from 5.0 to 79.7 mg/kg dry weight in the soil samples. There was no strict correlation between the total arsenic concentrations in the worms and soil. Arsenic compounds were extracted from soil and a freeze-dried earthworm sample with a methanol/water mixture (9:1, v/v). The extracts were evaporated to dryness, redissolved in water, and chromatographed on an anion- and a cation-exchange column. Arsenic compounds were identified by comparison of the retention times with known standards. Only traces of arsenic acid could be extracted from the soil with the methanol/water (9:1, v/v) mixture. The major arsenic compounds detected in the extracts of the earthworms were arsenous acid and arsenic acid. Arsenobetaine was present as a minor constituent, and traces of dimethylarsinic acid were also detected. Two dimethylarsinoyltribosides were also identified in the extracts by co-chromatography with standard compounds. This is the first report of the presence of dimethylarsinoylribosides in a terrestrial organism. Two other minor arsenic species were present in the extract, but their retention times did not match with the retention times of the available standards.

Geiszinger, A.; Goessler, W.; Kuehnelt, D.; Kosmus, W. [Karl-Franzens-Univ., Graz (Austria). Inst. for Analytical Chemistry] [Karl-Franzens-Univ., Graz (Austria). Inst. for Analytical Chemistry; Francesconi, K. [Odense Univ. (Denmark). Inst. of Biology] [Odense Univ. (Denmark). Inst. of Biology

1998-08-01

428

Superconductivity in palladium-based Heusler compounds  

NASA Astrophysics Data System (ADS)

This work reports on four more Heusler superconductors: Pd2ZrAl , Pd2HfAl , Pd2ZrIn , and Pd2HfIn . These compounds exhibit superconducting transition temperatures ranging from 2.4-3.8 K as determined by resistivity measurements. According to their behavior in an external magnetic field, all compounds are type II bulk superconductors. The occurrence of superconductivity was predicted for these compounds using electronic structure calculations. The electronic structures exhibit van Hove singularities (saddle points) at the L point. These lead to a maximum in the corresponding density of states and superconductivity according to the van Hove scenario. The superconducting properties of electron-doped and hole-doped substituted compounds Pd2B1-xBx'Al , whereby B=Zr and Hf, and B'=Y , Nb, and Mo, were investigated to obtain information about the dependence of the transition temperature on the density of states at the Fermi energy following the van Hove scenario. The calculated electronic structure reveals that the substituted compounds do not follow a rigid-band model. In addition, the random distribution of the substituted atoms strongly increases impurity-type electron scattering. The substituent concentrations used in this work lead to strongly enhanced impurity-type scattering and eventually to suppression of the superconducting state.

Winterlik, Jürgen; Fecher, Gerhard H.; Thomas, Anja; Felser, Claudia

2009-02-01

429

Reflectance spectroscopy of organic compounds: 1. Alkanes  

USGS Publications Warehouse

Reflectance spectra of the organic compounds comprising the alkane series are presented from the ultraviolet to midinfrared, 0.35 to 15.5 /??m. Alkanes are hydrocarbon molecules containing only single carbon-carbon bonds, and are found naturally on the Earth and in the atmospheres of the giant planets and Saturn's moon, Titan. This paper presents the spectral properties of the alkanes as the first in a series of papers to build a spectral database of organic compounds for use in remote sensing studies. Applications range from mapping the environment on the Earth, to the search for organic molecules and life in the solar system and throughout the. universe. We show that the spectral reflectance properties of organic compounds are rich, with major diagnostic spectral features throughout the spectral range studied. Little to no spectral change was observed as a function of temperature and only small shifts and changes in the width of absorption bands were observed between liquids and solids, making remote detection of spectral properties throughout the solar system simpler. Some high molecular weight organic compounds contain single-bonded carbon chains and have spectra similar to alkanes even ' when they fall into other families. Small spectral differences are often present allowing discrimination among some compounds, further illustrating the need to catalog spectral properties for accurate remote sensing identification with spectroscopy.

Clark, R.N.; Curchin, J.M.; Hoefen, T.M.; Swayze, G.A.

2009-01-01

430

The Chemistry of Nitroxyl-Releasing Compounds  

PubMed Central

Abstract Nitroxyl (HNO) demonstrates a diverse and unique biological profile compared to nitric oxide, a redox-related compound. Although numerous studies support the use of HNO as a therapeutic agent, the inherent chemical reactivity of HNO requires the use of donor molecules. Two general chemical strategies currently exist for HNO generation from nitrogen-containing molecules: (i) the disproportionation of hydroxylamine derivatives containing good leaving groups attached to the nitrogen atom and (ii) the decomposition of nitroso compounds (X-N=O, where X represents a good leaving group). This review summarizes the synthesis and structure, the HNO-releasing mechanisms, kinetics and by-product formation, and alternative reactions of six major groups of HNO donors: Angeli's salt, Piloty's acid and its derivatives, cyanamide, diazenium diolate-derived compounds, acyl nitroso compounds, and acyloxy nitroso compounds. A large body of work exists defining these six groups of HNO donors and the overall chemistry of each donor requires consideration in light of its ability to produce HNO. The increasing interest in HNO biology and the potential of HNO-based therapeutics presents exciting opportunities to further develop HNO donors as both research tools and potential treatments. Antioxid. Redox Signal. 14, 1637–1648. PMID:21235345

DuMond, Jenna F.

2011-01-01

431

Bioactive compounds from Rhodiola rosea (Crassulaceae).  

PubMed

The methanol extract of the underground part of Rhodiola rosea was found to show inhibitory activity against Staphylococcus aureus. Bioactivity-guided fractionation of a 95% ethanol extract from the stems of R. rosea led to the isolation of five compounds: gossypetin-7-O-L-rhamnopyranoside (1), rhodioflavonoside (2), gallic acid (3), trans-p-hydroxycinnamic acid (4) and p-tyrosol (5). Their structures were elucidated by UV, IR, MS and NMR data, as well as by comparison with those of the literature. Compounds 1 and 2 were evaluated for their antibacterial and antiprostate cancer cell activities. Compounds 1 and 2 exhibited activity against Staphylococcus aureus with minimum inhibitory concentrations of 50 microg/mL and 100 microg/mL, respectively. Cytotoxicity studies of 1 and 2 also displayed activity against the prostate cancer cell line with IC(50) values of 50 microg/mL and 80 microg/mL, respectively. PMID:16220564

Ming, Dong Sheng; Hillhouse, Brian J; Guns, Emma S; Eberding, Andy; Xie, Sherwin; Vimalanathan, Selvarani; Towers, G H Neil

2005-09-01

432

Origin of organic compounds in carbonaceous chondrites  

NASA Astrophysics Data System (ADS)

Carbonaceous chondrites, a class of primitive meteorite, have long been known to contain their complement of carbon largely in the form of organic, i.e., hydrocarbon-related, matter. Both discrete organic compounds and an insoluble, macromolecular material are present. Several characteristics of these materials provide evidence for their abiotic origin. The principal formation hypothesis have invoked chemistry occurring either in the solar nebula or on the parent body. However, recent stable isotope analyses of the meteorite carboxylic acids and amino acids indicate that they may be related to interstellar cloud compounds. These results suggest a formation scheme in which interstellar compounds were incorporated into the parent body and subsequently converted to the present suite of meteorite organics by the hydrothermal process believed to have formed the clay minerals of the meteorite matrix.

Cronin, J. R.

433

Volatile compounds in shergottite and nakhlite meteorites  

NASA Technical Reports Server (NTRS)

Since discovery of apparent carbonate carbon in Nakhla, significant evidence has accumulated for occurrence of volatile compounds in shergotties and nakhlites. Results are presented from a study of volatile compounds in three shergottites, one nakhlite, and three eucrite control samples. Shergotties ALHA77005, EETA79001, and Shergotty, and the nakhlite Nakhla, all contain oxidized sulfur (sulfate) of preterrestrial origin; sulfur oxidation is most complete in EETA79001/Lith-C. Significant bulk carbonate was confirmed in Nakhla and trace carbonate was substantiated for EETA79001, all of which appears to be preterrestrial in origin. Chlorine covaries with oxidized sulfur, whereas carbonate and sulfate are inversely related. These volatile compounds were probably formed in a highly oxidizing, aqueous environment sometime in the late stage histories of the rocks that are now represented as meteorites. They are consistent with the hypothesis that shergottite and nakhlite meteorites originated on Mars and that Mars has supported aqueous geochemistry during its history.

Gooding, James L.; Aggrey, Kwesi E.; Muenow, David W.

1990-01-01

434

Toxic organic compounds from energy production  

SciTech Connect

The US Department of Energy's Office of Health and Environmental Research (OHER) has supported work in our laboratory since 1977. The general theme of this program has been the identification of potentially toxic organic compounds associated with various combustion effluents, following the fates of these compounds in the environment, and improving the analytical methodology for making these measurements. The projects currently investigation include: an improved sampler for semi-volatile compounds in the atmosphere; the wet and dry deposition of dioxins and furans from the atmosphere; the photodegradation and mobile sources of dioxins and furans; and the bioaccumulation of PAH by tree bark. These projects are all responsive to OHER's interest in the pathways and mechanisms by which energy-related agents move through and are modified by the atmosphere''. The projects on gas chromatographic and liquid chromatographic tandem mass spectrometry are both responsive to OHER's interest in new and more sensitive technologies for chemical measurements''. 35 refs., 9 figs.

Hites, R.A.

1991-09-20

435

Chemosensors for detection of nitroaromatic compounds (explosives)  

NASA Astrophysics Data System (ADS)

The key types of low-molecular-mass chemosensors for the detection of nitroaromatic compounds representing energetic substances (explosives) are analyzed. The coordination and chemical properties of these chemosensors and structural features of their complexes with nitroaromatic compounds are considered. The causes and methods for attaining high selectivity of recognition are demonstrated. The primary attention is paid to the use of low-molecular-mass chemosensors for visual detection of explosives of this class by colorimetric and photometric methods. Examples of using photo- and chemiluminescence for this purpose are described. A separate section is devoted to electrochemical methods of detection of nitroaromatic compounds. Data published from 2000 to 2014 are mainly covered. The bibliography includes 245 references.

Zyryanov, G. V.; Kopchuk, D. S.; Kovalev, I. S.; Nosova, E. V.; Rusinov, V. L.; Chupakhin, O. N.

2014-09-01

436

Correlated Electronic Structures of Actinide Compounds  

NASA Astrophysics Data System (ADS)

Most modern nuclear fuels are actinides compounds, such as UO2 and PuO2 (mixed oxide fuel). First-principle study of these materials is challenging because of the electron correlation. In this work we present a systematic study of AcC, AcN and AcO2 (where Ac=U, Np, Pu, Am, Cm). In order to estimate the correlation strength, we calculate the effective U by constrained-DFT, and the charge-transfer energy. In early actinides compounds such as UC, 5f electrons are mostly itinerant (LSDA works fine), while in late actinide compounds such as CmN, 5f electrons are fully localized (LDA+U) . In the intermediate region, they show competition between localization and delocalization, thus for them LDA+DMFT is used to calculate the electronic structures. The results are compared with photoemission experiments where available.

Yin, Quan; Savrasov, Sergey; Pickett, Warren

2010-03-01

437

Energetic Compounds for Future Space Applications  

NASA Astrophysics Data System (ADS)

The need for new rocket propellants to improve or replace those in use today has led during the past ten years to studies of various, ancient or relatively new, energetic ingredients. The most often mentioned compounds for solid propellants are ADN (ammonium dinitramide), the nitramines RDX and HMX, HNIW (hexanitro hexaaza isowurtzitane), HNF (hydrazinum nitroformate), GAP (glycidyl azide polymer), and high nitrogen compounds. ADN, HNF, HAN (hydroxylammonium nitrate) are mentioned as possible ingredients in liquid mono and bi propellants for the future. A review of the work being conducted in the development and testing of the candidate propellants as well as an analysis of the general constraints of the industrial use and handling of these propellants and of their basic ingredients allows for a first tentative selection of the most promising ingredients. The possible synthesis routes, main characteristics, production and cost perspectives of these compounds are summarized and discussed.

Davenas, A.; Jacob, G.; Longevialle, Y.; Pérut, C.

2004-10-01

438

Heme compounds in dinosaur trabecular bone.  

PubMed

Six independent lines of evidence point to the existence of heme-containing compounds and/or hemoglobin breakdown products in extracts of trabecular tissues of the large theropod dinosaur Tyrannosaurus rex. These include signatures from nuclear magnetic resonance and electron spin resonance that indicate the presence of a paramagnetic compound consistent with heme. In addition, UV/visible spectroscopy and high performance liquid chromatography data are consistent with the Soret absorbance characteristic of this molecule. Resonance Raman profiles are also consistent with a modified heme structure. Finally, when dinosaurian tissues were extracted for protein fragments and were used to immunize rats, the resulting antisera reacted positively with purified avian and mammalian hemoglobins. The most parsimonious explanation of this evidence is the presence of blood-derived hemoglobin compounds preserved in the dinosaurian tissues. PMID:9177210

Schweitzer, M H; Marshall, M; Carron, K; Bohle, D S; Busse, S C; Arnold, E V; Barnard, D; Horner, J R; Starkey, J R

1997-06-10

439

Diazo compounds in continuous-flow technology.  

PubMed

Diazo compounds are very versatile reagents in organic chemistry and meet the challenge of selective assembly of structurally complex molecules. Their leaving group is dinitrogen; therefore, they are very clean and atom-efficient reagents. However, diazo compounds are potentially explosive and extremely difficult to handle on an industrial scale. In this review, it is discussed how continuous flow technology can help to make these powerful reagents accessible on large scale. Microstructured devices can improve heat transfer greatly and help with the handling of dangerous reagents safely. The in?situ formation and subsequent consumption of diazo compounds are discussed along with advances in handling diazomethane and ethyl diazoacetate. The potential large-scale applications of a given methodology is emphasized. PMID:25488620

Müller, Simon T R; Wirth, Thomas

2015-01-01

440

Dosimetry of [??Ga]-labeled compounds.  

PubMed

This review compiles and analyzes the available dosimetry data of [(68)Ga] labeled compounds. Dosimetry data are given for [(68)Ga]DOTA-NOC, TOC, TATE, and NODAGA-RGDyK. The number of PET-scans with [(68)Ga]DOTA-compounds for imaging neuroendocrine tumors is increasing because [(68)Ga] has a higher affinity to somatostatin receptors (SSTR) in comparison to comparable [(111)In]-compounds. In addition, the better image resolution of the PET images provides improved diagnostics. Despite its widespread use literature on dosimetry of [(68)Ga]-labeled radiopharmaceuticals is sparse. In some cases the description of the underlying methodology is missing or human data are gained from the extrapolation of animal experiments. More and better documented dosimetry data will further promote the use of these promising new agents. PMID:22884623

Eberlein, U; Lassmann, M

2013-06-01

441

Driving Magnetostructural Transitions in Layered Intermetallic Compounds  

NASA Astrophysics Data System (ADS)

We report the dramatic effect of applied pressure and magnetic field on the layered intermetallic compound Pr0.5Y0.5Mn2Ge2. In the absence of pressure or magnetic field this compound displays interplanar ferromagnetism at room temperature and undergoes an isostructural first order magnetic transition (FOMT) to an antiferromagnetic state below 158 K, followed by another FOMT at 50 K due to the reemergence of ferromagnetism as praseodymium orders (TCPr). The application of a magnetic field drives these two transitions towards each other, whereas the application of pressure drives them apart. Pressure also produces a giant magnetocaloric effect such that a threefold increase of the entropy change associated with the lower FOMT (at TCPr) is seen under a pressure of 7.5 kbar. First principles calculations, using density functional theory, show that this remarkable magnetic behavior derives from the strong magnetoelastic coupling of the manganese layers in this compound.

Wang, J. L.; Caron, L.; Campbell, S. J.; Kennedy, S. J.; Hofmann, M.; Cheng, Z. X.; Md Din, M. F.; Studer, A. J.; Brück, E.; Dou, S. X.

2013-05-01

442

Magnetic phase transitions in layered intermetallic compounds  

NASA Astrophysics Data System (ADS)

Magnetic, magnetoelastic, and magnetotransport properties have been studied for the RMn2Si2 and RMn6Sn6 (R is a rare earth metal) intermetallic compounds with natural layered structure. The compounds exhibit wide variety of magnetic structures and magnetic phase transitions. Substitution of different R atoms allows us to modify the interatomic distances and interlayer exchange interactions thus providing the transition from antiferromagnetic to ferromagnetic state. Near the boundary of this transition the magnetic structures are very sensitive to the external field, temperature and pressure. The field-induced transitions are accompanied by considerable change in the sample size and resistivity. It has been shown that various magnetic structures and magnetic phase transitions observed in the layered compounds arise as a result of competition of the Mn-Mn and Mn-R exchange interactions.

Mushnikov, N. V.; Gerasimov, E. G.; Rosenfeld, E. V.; Terent'ev, P. B.; Gaviko, V. S.

2012-10-01

443

Catalyst for Oxidation of Volatile Organic Compounds  

NASA Technical Reports Server (NTRS)

Disclosed is a process for oxidizing volatile organic compounds to carbon dioxide and water with the minimal addition of energy. A mixture of the volatile organic compound and an oxidizing agent (e.g. ambient air containing the volatile organic compound) is exposed to a catalyst which includes a noble metal dispersed on a metal oxide which possesses more than one oxidation state. Especially good results are obtained when the noble metal is platinum, and the metal oxide which possesses more than one oxidation state is tin oxide. A promoter (i.e., a small amount of an oxide of a transition series metal) may be used in association with the tin oxide to provide very beneficial results.

Wood, George M. (Inventor); Upchurch, Billy T. (Inventor); Schryer, David R. (Inventor); Davis, Patricia P. (Inventor); Kielin, Erik J. (Inventor); Brown, Kenneth G. (Inventor); Schyryer, Jacqueline L. (Inventor); DAmbrosia, Christine M. (Inventor)

2000-01-01

444

[The vanadium compounds: chemistry, synthesis, insulinomimetic properties].  

PubMed

The review considers the biological role of vanadium, its participation in various processes in humans and other mammals, and the anti-diabetic effect of its compounds. Vanadium salts have persistent hypoglycemic and antihyperlipidemic effects and reduce the probability of secondary complications in animals with experimental diabetes. The review contains a detailed description of all major synthesized vanadium complexes having antidiabetic activity. Currently, vanadium complexes with organic ligands are more effective and safer than the inorganic salts. Despite the proven efficacy of these compounds as the anti-diabetic agents in animal models, only one organic complex of vanadium is currently under the second phase of clinical trials. All of the considered data suggest that vanadium compound are a new promising class of drugs in modern pharmacotherapy of diabetes. PMID:25249525

Fedorova, E V; Buriakina, A V; Vorob'eva, N M; Baranova, N I

2014-01-01

445

Sulfur and sulfur compounds in plant defence.  

PubMed

The multiplicity of chemical structures of sulfur containing compounds, influenced in part by the element's several oxidation states, directly results in diverse modes of action for sulfur-containing natural products synthesized as secondary metabolites in plants. Sulfur-containing natural products constitute a formidable wall of defence against a wide range of pathogens and pests. Steady progress in the development of new technologies have advanced research in this area, helping to uncover the role of such important plant defence molecules like endogenously-released elemental sulphur, but also deepening current understanding of other better-studied compounds like the glucosinolates. As studies continue in this area, it is becoming increasingly evident that sulfur and sulfur compounds play far more important roles in plant defence than perhaps previously suspected. PMID:22545416

Nwachukwu, Ifeanyi D; Slusarenko, Alan J; Gruhlke, Martin C H

2012-03-01

446

Biological and nonbiological modifications of organophosphorus compounds*  

PubMed Central

The general types of biological reaction that are most prominent in the modification of organophosphorus compounds involve the mixed-function oxidases, hydrolases, or transferases. In certain cases, more than one of these reactions may be involved at the same site on the pesticide molecule. Examples of various organophosphorus pesticides that are altered by oxidation, hydrolysis, alkyl- or aryl-group transfer, reduction, and conjugation are discussed. The increase or decrease in toxicity of a pesticide that can result from biological modification is emphasized. Non-biological transformations of organophosphorus compounds involve the effect ou the compounds of such factors as light, air, temperature, and solvent. These factors are discussed with special emphasis on desulfuration, rearrangement, and oxidation. PMID:4938021

Dauterman, W. C.

1971-01-01

447

Global Exposure Modelling of Semivolatile Organic Compounds  

NASA Astrophysics Data System (ADS)

Organic compounds which are persistent and toxic as the agrochemicals ?-hexachlorocyclohexane (?-HCH, lindane) and dichlorodiphenyltrichloroethane (DDT) pose a hazard for the ecosystems. These compounds are semivolatile, hence multicompartmental substances and subject to long-range transport (LRT) in atmosphere and ocean. Being lipophilic, they accumulate in exposed organism tissues and biomagnify along food chains. The multicompartmental global fate and LRT of DDT and lindane in the atmosphere and ocean have been studied using application data for 1980, on a decadal scale using a model based on the coupling of atmosphere and (for the first time for these compounds) ocean General Circulation Models (ECHAM5 and MPI-OM). The model system encompasses furthermore 2D terrestrial compartments (soil and vegetation) and sea ice, a fully dynamic atmospheric aerosol (HAM) module and an ocean biogeochemistry module (HAMOCC5). Large mass fractions of the compounds are found in soil. Lindane is also found in comparable amount in ocean. DDT has the longest residence time in almost all compartments. The sea ice compartment locally almost inhibits volatilization from the sea. The air/sea exchange is also affected , up to a reduction of 35 % for DDT by partitioning to the organic phases (suspended and dissolved particulate matter) in the global oceans. Partitioning enhances vertical transport in the sea. Ocean dynamics are found to be more significant for vertical transport than sinking associated with particulate matter. LRT in the global environment is determined by the fast atmospheric circulation. Net meridional transport taking place in the ocean is locally effective mostly via western boundary currents, upon applications at mid- latitudes. The pathways of the long-lived semivolatile organic compounds studied include a sequence of several cycles of volatilisation, transport in the atmosphere, deposition and transport in the ocean (multihopping substances). Multihopping is more significant for DDT than for lindane. It enhances the LRT potential for both compounds.

Guglielmo, F.; Lammel, G.; Maier-Reimer, E.

2008-12-01

448

Antiviral Lead Compounds from Marine Sponges  

PubMed Central

Marine sponges are currently one of the richest sources of pharmacologically active compounds found in the marine environment. These bioactive molecules are often secondary metabolites, whose main function is to enable and/or modulate cellular communication and defense. They are usually produced by functional enzyme clusters in sponges and/or their associated symbiotic microorganisms. Natural product lead compounds from sponges have often been found to be promising pharmaceutical agents. Several of them have successfully been approved as antiviral agents for clinical use or have been advanced to the late stages of clinical trials. Most of these drugs are used for the treatment of human immunodeficiency virus (HIV) and herpes simplex virus (HSV). The most important antiviral lead of marine origin reported thus far is nucleoside Ara-A (vidarabine) isolated from sponge Tethya crypta. It inhibits viral DNA polymerase and DNA synthesis of herpes, vaccinica and varicella zoster viruses. However due to the discovery of new types of viruses and emergence of drug resistant strains, it is necessary to develop new antiviral lead compounds continuously. Several sponge derived antiviral lead compounds which are hopedto be developed as future drugs are discussed in this review. Supply problems are usually the major bottleneck to the development of these compounds as drugs during clinical trials. However advances in the field of metagenomics and high throughput microbial cultivation has raised the possibility that these techniques could lead to the cost-effective large scale production of such compounds. Perspectives on biotechnological methods with respect to marine drug development are also discussed. PMID:21116410

Sagar, Sunil; Kaur, Mandeep; Minneman, Kenneth P.

2010-01-01

449

Antiviral lead compounds from marine sponges.  

PubMed

Marine sponges are currently one of the richest sources of pharmacologically active compounds found in the marine environment. These bioactive molecules are often secondary metabolites, whose main function is to enable and/or modulate cellular communication and defense. They are usually produced by functional enzyme clusters in sponges and/or their associated symbiotic microorganisms. Natural product lead compounds from sponges have often been found to be promising pharmaceutical agents. Several of them have successfully been approved as antiviral agents for clinical use or have been advanced to the late stages of clinical trials. Most of these drugs are used for the treatment of human immunodeficiency virus (HIV) and herpes simplex virus (HSV). The most important antiviral lead of marine origin reported thus far is nucleoside Ara-A (vidarabine) isolated from sponge Tethya crypta. It inhibits viral DNA polymerase and DNA synthesis of herpes, vaccinica and varicella zoster viruses. However due to the discovery of new types of viruses and emergence of drug resistant strains, it is necessary to develop new antiviral lead compounds continuously. Several sponge derived antiviral lead compounds which are hoped to be developed as future drugs are discussed in this review. Supply problems are usually the major bottleneck to the development of these compounds as drugs during clinical trials. However advances in the field of metagenomics and high throughput microbial cultivation has raised the possibility that these techniques could lead to the cost-effective large scale production of such compounds. Perspectives on biotechnological methods with respect to marine drug development are also discussed. PMID:21116410

Sagar, Sunil; Kaur, Mandeep; Minneman, Kenneth P

2010-01-01

450

Natural compounds for pest and weed control.  

PubMed

The control of insect pests and invasive weeds has become more species-selective because of activity-guided isolation, structure elucidation, and total synthesis of naturally produced substances with important biological activities. Examples of isolated compounds include insect pheromones, antifeedants, and prostaglandins, as well as growth regulators for plants and insects. Synthetic analogues of natural substances have been prepared to explore the relationships between chemical structure and observed biological activity. Recent scientific advances have resulted from better methods for the chemical synthesis of target compounds and better analytical methods. The capability of analytical instrumentation continues to advance rapidly, enabling new insights. PMID:19719128

Petroski, Richard J; Stanley, David W

2009-09-23

451

Compound Composite Odontoma and Its Management  

PubMed Central

Odontomas are odontogenic benign tumors composed of dental tissue. Majority of these lesions are asymptomatic and are often detected on routine radiographs. They can be thought of as “tooth hamartomas" with the lesion consisting of various tooth components. They are divided histologically into complex odontomas and compound odontomas. This paper describes the case of a compound odontoma in a 13-year-old girl diagnosed due to the retention of the primary right mandibular second molar. A surgical excision was performed without disturbing the unerupted premolar. The results achieved indicate that early diagnosis of odontomas enables adoption of less complex treatment, a better prognosis, and displacement or devitalisation of adjacent tooth. PMID:25587458

Abdul, Morawala; Pragati, Kapila; Yusuf, Chunawala

2014-01-01

452

Optical flow on a linear compound array  

NASA Astrophysics Data System (ADS)

The compound eye of the insect in its simplest concept creates an image from the environment over a solid angle, yet in practice angular resolution varies significantly across most compound eyes. We have examined the case of linear optical (paraxial) arrays in which optical axes are parallel. We demonstrate that a paraxial array directly measures the speed of translation orthogonal to the optical axes, while when rotated, it detects range as a ratio of optical flow and angular velocity. A series of experiments was conducted to demonstrate the viability of the device.

Chahl, Javaan

2014-03-01

453

Dry etching method for compound semiconductors  

DOEpatents

A dry etching method is disclosed. According to the present invention, a gaseous plasma comprising, at least in part, boron trichloride, methane, and hydrogen may be used for dry etching of a compound semiconductor material containing layers including aluminum, or indium, or both. Material layers of a compound semiconductor alloy such as AlGaInP or the like may be anisotropically etched for forming electronic devices including field-effect transistors and heterojunction bipolar transistors and for forming photonic devices including vertical-cavity surface-emitting lasers, edge-emitting lasers, and reflectance modulators. 1 fig.

Shul, R.J.; Constantine, C.

1997-04-29

454

Metastable Equilibria Among Aqueous Organic Compounds  

NASA Astrophysics Data System (ADS)

Metastable equilibrium states exist when reactions among a subset of compounds in a chemical system are reversible even though other irreversible reactions exist in the same system. The existence of metastable equilibrium among organic compounds was initially detected by comparing ratios of organic acid concentrations reported for oil-field brines (Shock, 1988, Geology 16, 886-890; Shock, 1989, Geology 17, 572-573), and calculating the same ratios for likely oxidation states determined by mineral assemblages and mixtures of hydrocarbons in coexisting petroleum (Shock, 1994, in: The Role of Organic Acids in Geological Processes, Springer). This led to the notion of extending the concept of metastable equilibrium states to explicitly account for petroleum compositions (Helgeson et al., 1993, GCA, 57, 3295-3339), which eventually yielded the concept of hydrolytic disproportionation of kerogens to produce petroleum and CO2(g) (Helgeson et al., 2009, GCA, 73, 594-695). Experimental tests of metastable equilibrium among organic compounds began with the identification of reversible reactions between alkanes and alkenes that are dependent on the H2 fugacity of the experimental system (Seewald, 1994, Nature 370, 285-287). These were followed with a comprehensive series of long-term experiments leading to the hypothesis that reversible reactions include alkanes, alkenes, alcohol, aldehydes, ketones and carboxylic acids (e.g., Seewald, 2001, GCA 65, 1641-1664; 2003, Nature 426, 327-333; McCollom & Seewald, 2003, GCA 67, 3645-3664). We have conducted sets of hydrothermal organic transformation experiments that test the extent to which these reactions are indeed reversible using aromatic and cyclic compounds. Results demonstrate reversibility for reactions among dibenzyl ketone, 1,3-diphenyl-2-propanol, 1,3-diphenylpropene and 1,3-diphenylpropane, as well as among methylcyclohexanes, methylcyclohexenes, methylcyclohexanols, methylcyclohexanones and methylcyclohexadienes. The compounds chosen for study include structural features that provide mechanistic insight into the reactions. By including cyclic and aromatic compounds, these results expand the diversity of organic compounds that react reversibly in geochemical processes. It follows that metastable equilibria among organic compounds may be inescapable during hydrothermal alteration and petroleum generation.

Shock, E.; Shipp, J.; Yang, Z.; Gould, I. R.

2011-12-01

455

Organic photosensitive devices using subphthalocyanine compounds  

DOEpatents

An organic photosensitive optoelectronic device, having a donor-acceptor heterojunction of a donor-like material and an acceptor-like material and methods of making such devices is provided. At least one of the donor-like material and the acceptor-like material includes a subphthalocyanine, a subporphyrin, and/or a subporphyrazine compound; and/or the device optionally has at least one of a blocking layer or a charge transport layer, where the blocking layer and/or the charge transport layer includes a subphthalocyanine, a subporphyrin, and/or a subporphyrazine compound.

Rand, Barry (Princeton, NJ); Forrest, Stephen R. (Ann Arbor, MI); Mutolo, Kristin L. (Hollywood, CA); Mayo, Elizabeth (Alhambra, CA); Thompson, Mark E. (Anaheim Hills, CA)

2011-07-05

456

Thin film Heusler compounds manganese nickel gallium  

NASA Astrophysics Data System (ADS)

Multiferroic Heusler compounds Mn3--xNi xGa (x=0,1,2) have a tetragonal unit cell that can variously be used for magneto-mechanically coupled shape memory ( x=1,2) and spin-mechanical applications (x=0). The first fabrication of fully epitaxial thin films of these and electronically related compounds by sputtering is discussed. Traditional and custom lab characterization of the magnetic and temperature driven multiferroic behavior is augmented by more detailed synchrotron-based high energy photoemission spectroscopic techniques to describe the atomic and electronic structure. Integration of the MnNi2Ga magnetic shape memory compound in microwave patch antennas and active free-standing structures represents a fraction of the available and promising applications for these compounds. Prototype magnetic tunnel junctions are demonstrated by Mn3Ga electrodes with perpendicular anisotropy for spin torque transfer memory structures. The main body of the work concentrates on the definition and exploration of the material series Mn3--xNi xGa (x=0,1,2) and the relevant multiferroic phenomena exhibited as a function of preparation and external stimuli. Engineering results on each x=0,1,2 are presented with device prototypes where relevant. In the appendices the process of the materials design undertaken with the goal of developing new ternary intermetallics with enhanced properties is presented with a full exploration of the road from band structure calculations to device implementation. Cobalt based compounds in single crystal and nanoparticle form are fabricated with an eye to developing the production methods for new cobalt- and iron-based magnetic shape memory compounds for device applications in different forms. Mn2CoSn, a compound isolectronic and with similar atomic ordering to Mn2NiGa is experimentally determined to be a nearly half-metallic ferromagnet in contrast to the metallic ferrimagnetism in the parent compound. High energy photoemission spectroscopy is shown to be applicable to the analysis and observation of deeply buried metallic and semiconducting interface in an analysis of chalcopyrite solar cell heterolayers and model magnetic tunnel junctions with half-metalic Heusler electrodes.

Jenkins, Catherine Ann

457

Assessment of phenolic compounds in biological samples.  

PubMed

A short review of extraction, purification and cleanup procedures for the analysis of phenolic compounds (anthocyanins, flavonoids, catechins, phenolic acids, etc.) in animal and human biological fluids and organs is presented. The rising interest about the antioxidant capacity of these widespread constituents of fruit and vegetables enables these procedures an invaluable tool prior of the separation and identification of these compounds and their metabolites occurring in the organism. Finally, the usual chromatographic and spectrophotometric analytical techniques for their separation and identification are briefly summarized. PMID:18209269

Miniati, Enrico

2007-01-01

458

Photochemistry and Photophysics of Coordination Compounds: Copper  

Microsoft Academic Search

Cu(I) complexes and clusters are the largest class of compounds of relevant photochemical and photophysical\\u000a interest based on a relatively abundant metal element. Interestingly, Nature has given an essential\\u000a role to copper compounds in some biological systems, relying on their kinetic lability and versatile coordination\\u000a environment. Some basic properties of Cu(I) and Cu(II) such as their coordination geometries and electronic\\u000a levels

Nicola Armaroli; Gianluca Accorsi; François Cardinali; Andrea Listorti

459

Process for producing phenolic compounds from lignins  

SciTech Connect

A process for the production of low molecular weight phenolic compounds from lignins through the pyrolysis of the lignins in the presence of a strong base. In a preferred embodiment, potassium hydroxide is present in an amount of from about 0.1% to about 5% by weight, the pyrolysis temperature is from about 400.degree. C. to about 600.degree. C. at atmospheric pressure, and the time period for substantial completion of the reaction is from about 1-3 minutes. Examples of low molecular weight phenolic compounds produced include methoxyphenols, non-methoxylated phenols, and mixtures thereof.

Agblevor, Foster A. (Lakewood, CO)

1998-01-01

460

Process for producing phenolic compounds from lignins  

SciTech Connect

A process is described for the production of low molecular weight phenolic compounds from lignins through the pyrolysis of the lignins in the presence of a strong base. In a preferred embodiment, potassium hydroxide is present in an amount of from about 0.1% to about 5% by weight, the pyrolysis temperature is from about 400 C to about 600 C at atmospheric pressure, and the time period for substantial completion of the reaction is from about 1--3 minutes. Examples of low molecular weight phenolic compounds produced include methoxyphenols, non-methoxylated phenols, and mixtures thereof. 16 figs.

Agblevor, F.A.

1998-09-15

461

Dietary derived compounds in cancer chemoprevention  

PubMed Central

Cancer chemoprevention is defined as the application of natural or synthetic agents to suppress or reverse cancer development and progression. In this field especially diet derived compounds have recently attracted researchers’ attention as potential therapeutics generally exerting low toxicity compared with regular drugs. This review presents a survey of recent findings concerning the most promising dietary chemopreventive agents such as green tea polyphenols (i.e. catechins), long-chain polyunsaturated fatty acids, carotenoids, glucosinolates/isothiocyanates, vitamins (i.e. vitamin D and folate) and minerals (i.e. calcium and selenium). Molecular targets involved in intrinsic pathways affected by these natural compounds are also shortly discussed. PMID:23788916

Rzeski, Wojciech

2012-01-01

462

Inelastic neutron scattering in valence fluctuation compounds  

SciTech Connect

The valence fluctuation compounds are rare earth intermetallics where hybridization of the nearly-localized 4f electrons with the conduction electrons leads to incorporation of the 4f's into the itinerant states. This hybridization slows down the conduction electrons and hence gives them a heavy effective mass, justifying application of the term 'heavy Fermion' (HF) to these materials. During the project period, we grew large single crystals of several such compounds and measured their properties using both standard thermodynamic probes and state-of-the-art inelastic neutron scattering. We obtained three main results. For the intermediate valence compounds CePd{sub 3} and YbAl{sub 3}, we showed that the scattering of neutrons by the fluctuations of the 4f magnetic moment does not have the momentum dependence expected for the itinerant heavy mass state; rather, the scattering is more typical of a localized spin fluctuation. We believe that incoherent scattering localizes the excitation. For the heavy Fermion compound Ce(Ni{sub 0.935}Pd{sub 0.065}){sub 2}Ge{sub 2}, which sits at a T = 0 critical point for transformation into an antiferromagnetic (AF) phase, we showed that the scattering from the AF fluctuations does not exhibit any of the divergences that are expected at a phase transition. We speculate that alloy disorder profoundly suppresses the growth of the fluctuating AF regions, leading to short range clusters rather than regions of infinite size. Finally, we explored the applicability of key concepts used to describe the behavior of rare earth heavy Fermions to uranium based HF compounds where the 5f electrons are itinerant as opposed to localized. We found that scaling laws relating the spin fluctuation energy measured in neutron scattering to the low temperature specific heat and susceptibility are valid for the uranium compounds, once corrections are made for AF fluctuations; however, the degeneracy of the high temperature moment is smaller than expected for rare-earth-like Hund's rule behavior, essentially because the orbital moment is suppressed for itinerant 5f electrons. We also found that the standard local-moment-based theory of the temperature dependence of the specific heat, susceptibility and neutron scattering fails badly for URu{sub 2}Zn{sub 20} and UCo{sub 2}Zn{sub 20}, even though the theory is phenomenally successful for the closely related rare earth compound YbFe{sub 2}Zn{sub 20}. Both these results highlight the distinction between the itineracy of the 5f's and the localization of the 4f's. It is our hope that these results are sufficiently significant as to stimulate deeper investigation of these compounds.

Jon M Lawrence