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1

Thermochemistry of uranium compounds: XVI, Calorimetric determination of the standard molar enthalpy of formation at 298.15 K, low-temperature heat capacity, and high-temperature enthalpy increments of UOâ(OH)â · HâO (schoepite)  

Microsoft Academic Search

Three precise calorimetric methods, viz., low-temperature adiabatic, high-temperatuare drop, and solution-reaction, have been used to determine as a function of temperature the key chemical thermodynamic properties of a pure sample of schoepite, UOâ(OH)â · HâO. The following results have been obtained at the standard reference temperature T = 298.15 K:standard molar enthalpy of formation Î\\/sub f\\/H\\/sub m\\/°(T) = -1825.4 +-

I. R. Tasker; B. M. Lewis; G. K. Johnson; E. H. P. Cordfunke

1987-01-01

2

Thermochemistry of uranium compounds: XVI, Calorimetric determination of the standard molar enthalpy of formation at 298.15 K, low-temperature heat capacity, and high-temperature enthalpy increments of UO{sub 2}(OH){sub 2} {center_dot} H{sub 2}O (schoepite)  

SciTech Connect

Three precise calorimetric methods, viz., low-temperature adiabatic, high-temperatuare drop, and solution-reaction, have been used to determine as a function of temperature the key chemical thermodynamic properties of a pure sample of schoepite, UO{sub 2}(OH){sub 2} {center_dot} H{sub 2}O. The following results have been obtained at the standard reference temperature T = 298.15 K:standard molar enthalpy of formation {Delta}/sub f/H/sub m/{sup 0}(T) = {minus}1825.4 +- 2.1 kJ mol/sup {minus}1/; molar heat capacity C/sub p,m/{sup 0}(T) = 172.07 +- 0.34 JK/sup {minus}1/; and the standard molar entropy S/sub m/{sup 0}(T) = 188.54 +- 0.38 JK/sup {minus}1/ mol/sup {minus}1/. The molar enthalpy increments relative to 298.15 K and the molar heat capacity are given by the polynomials: {H{sub m}{sup 0}(T) {minus} H{sub m}{sup 0}(298.15 K)}/(J mol/sup {minus}1/) = {minus}38209.0 + 84.2375 (T/K) + 0.1472958 (T/K){sup 2} and C/sub p,m/{sup 0}(T)/(JK/sup {minus}1/ mol/sup {minus}1/) = 84.238 + 0.294592 (T/K), where 298.15 K < T < 400 K. The present result for {Delta}/sup f/H/sub m/{sup 0} at 298.15 K has been combined with three other closely-agreeing values from the literature to give a recommended weighted mean {Delta}/sub f/H/sub m/{sup 0} = {minus}1826.4 +- 1.7 kJ mol/sup {minus}1/, from which is calculated the standard Gibbs energy of formation {Delta}/sub f/G/sub m/{sup 0} = {minus}1637.0 +- 1.7 kJ mol/sup {minus}1/ at 298.15 K. Complete thermodynamic properties of schoepite are tabulated from 298.15 to 423.15 K. 19 refs., 6 tabs.

Tasker, I.R.; O`Hare, P.A.G.; Lewis, B.M.; Johnson, G.K.; Cordfunke, E.H.P.

1987-08-01

3

Pope Benedict XVI's \\  

Microsoft Academic Search

“Business ethics risks becoming subservient to existing economic and financial systems rather than correcting their dysfunctional aspects.” This statement from Pope Benedict XVI’s Encyclical letter \\

Stormes James R S. J

2010-01-01

4

Quantitative differential scanning calorimetric analysis for determining total polar compounds in heated oils  

Microsoft Academic Search

A new differential scanning calorimetry (DSC) method was developed for the determination of total polar compounds (TPC) in\\u000a heated oils. Three different types of edible oils, refined, bleached, and deodorized corn oil (CO), palm olein (RBDPO), and\\u000a soybean oil (SO), were used in this study, Each type of edible oil was heated at 180°C in a deep fryer to obtain

C. P. Tan; Y. B. Che Man

1999-01-01

5

BENEDICT XVI: PEACEMAKER  

Microsoft Academic Search

Pope Benedict XVI has had unexpected success as a religious diplomat, advocating for peace between Christians and Muslims. Despite offending the Muslim community in a speech given during his first year as Pope, he has since taken great steps towardsreconciliation. At a public appearance in Turkey in 2007, Pope Benedict and Muslims leaders emphasized the commonalities between their religions in

Drew Christiansen S. J

2007-01-01

6

Calorimetric monitoring of lyophilization.  

PubMed

This paper describes an apparatus and method for monitoring the lyophilization of a formulation by using calorimetric measurements. From calorimetric measurements, the energy transferred during each phase of the process can be determined. A brief review of the existing monitoring methods shows that they possess no direct relationship to the thermal energy that represents the real driving force for the lyophilization process. A general description of the apparatus is presented with special emphasis made on the sensor construction and calibration. The means for determining the heat transfer rate (Qm) and total energy (Hm) for each step of the process are described. The use of calorimetric measurements are demonstrated by showing actual thermographs of freezing, primary drying and secondary drying processes for several formulations. Some key advantages of calorimetric monitoring of the lyophilization process are demonstrated by accurately determining the completion of the primary drying and detection of exothermic reactions during the secondary drying. PMID:8581458

Jennings, T A; Duan, H

7

Low-dimensional compounds containing cyano groups. XVI. (Dicyanamido-kappaN1)bis(1,10-phenanthroline-kappa(2)N,N')copper(II) tetrafluoridoborate.  

PubMed

The title compound, [Cu{N(CN)(2)}(C(12)H(8)N(2))(2)]BF(4), was prepared as part of our study of the shape of coordination polyhedra in five-coordinated copper(II) complexes. Single-crystal X-ray analysis reveals that the structure consists of [Cu{N(CN)(2)}(phen)(2)](+) cations (phen is 1,10-phenanthroline) and BF(4)(-) anions. The Cu centre is five-coordinated in a distorted trigonal bipyramidal manner by four N atoms of two phen ligands and one N atom of a dicyanamide anion, which is coordinated in the equatorial plane at a distance of 1.996 (2) A. The two axial Cu-N(phen) distances have similar values [average 1.994 (6) A] and are shorter than the two equatorial Cu-N(phen) bonds [average 2.09 (6) A]. This work demonstrates the effect of ligand rigidity on the shape of coordination polyhedra in five-coordinated copper(II) complexes. PMID:18391377

Potocnák, Ivan; Spilovský, Martin; Trávnícek, Zdenek

2008-03-15

8

Calorimetric electron telescope mission  

Microsoft Academic Search

We are developing the CALorimetric Electron Telescope, CALET, mission for the Japanese Experiment Module—Exposed Facility, JEM-EF, of the International Space Station, ISS. Major scientific objective is a search for nearby cosmic ray sources and dark matter by carrying out a precise measurement of the electrons in 1GeV–20TeV and the gamma-rays in 20MeV-several TeV. CALET has, moreover, a capability to measure

Shoji Torii

2011-01-01

9

Superconductivity in the misfit compound of (LaSe)1.14(NbSe2): STM/S, calorimetric and magnetization studies  

NASA Astrophysics Data System (ADS)

(LaSe)1.14(NbSe2) is a low temperature superconductor with Tc around 1.2 K belonging to the family of the lamellar chalcogenides. Electron transfer from the LaSe to the NbSe2 slab results in a natural layered system of the insulating LaSe and (super) conducting NbSe2 sheets. In our previous investigations of the anisotropic transport [P. Szabó et al., Phys. Rev. Lett. 86, 5990 (2001)] indications have been found that this system behaves as a stack of Josephson-coupled superconducting NbSe2 sheets separated by insulating LaSe layers. We test this hypothesis by STM/S measurements at subkelvin temperatures and in magnetic fields. Superconducting energy gap obtained by STM opens at the same temperature and field where the interlayer resistivity starts to increase before drop to zero value. Before any conclusions are made homogeneity of the superconducting parameters is to be tested. STM indicates large areas without any gap but calorimetric measurements have shown the bulk superconductivity and magnetization revealed extremely low pinning.

Samuely, P.; Szabo, P.; Kacmarcik, J.; Pribulova, Z.; Samuely, T.; Rodrigo, J. G.; Marcenat, C.; Klein, T.; Cario, L.

2013-03-01

10

Calorimetric properties of magmas  

NASA Astrophysics Data System (ADS)

Magmatic and volcanic processes are strongly controlled by the physical and thermodynamic properties of silicate melts. Recently it has been recognized that the way in which the magma crosses the so-called "glass transition" boundary can determine whether a quite degassing, through preferential pathways, or a catastrophic eruption will take place. On the other hand, the thermodynamic properties inform us regarding the internal energy of melts and crystals and how internal energy and other closely related thermodynamic functions change with temperature, so affecting processes as partial melting, solidification, the advective transport of heat, and volatile exsolution and degassing. The effect of volatiles on these properties is well recognized, but not satisfactorily investigated so far. In this study, calorimetric measurements were conducted on four series of variously hydrated multicomponent melts, obtained by remelting and homogeneization of natural magmas in order to investigate the effect of water on the glass transition interval (Tg) and heat capacity (Cp). The hydrous samples were synthesized in a piston cylinder and measured by the employement of a differential scanning calorimeter (DSC). Pantelleritic, latitic, HK basaltic and trachybasaltic compositions have been analysed over a range of water contents up to 5.3 wt%.For each investigated melt composition the cooling rate dependence of Tg has been characterized at four different temperatures corresponding to the onset, the inflection point, the peak and the stable liquid regions of the heat capacity curves. Tg of all compositions are strongly reduced by increasing water content. Base composition also has an effect, with the lowest Tg occurring in pantelleritic suite. For all sample a clear dependence on cooling/heating rate has been recorded. Peak and onset glass transition temperatures show constant viscosity values at differing water contents. Moreover the activation energies yielded by calorimetric and viscosimetry are, within experimental error, identical. This confirm that the calculation of viscosity through the employment of a simple shift factor, as already proposed by previous authors, can be used, for the investigated samples. So far it concern the effect of water on the heat capacities, we show that water has important effect and that complex patterns are observed for different compositional suites.

di Genova, Danilo; Giordano, Daniele; Romano, Claudia; Alletti, Marina; Scaillet, Bruno

2010-05-01

11

Pope Benedict XVI Confronts Religious Relativism  

Microsoft Academic Search

Pope Benedict XVI’s inflammatory speech at Regensburg highlights a subtle difference between Benedict and John Paul II. John\\u000a Paul called Muslims and Jews “sons of Abraham,” and he organized high-profile interfaith events. Benedict is more skeptical\\u000a of interreligious dialog and more confrontational toward Islam than was his predecessor. This shift in tone toward Islam stems\\u000a from changed historical circumstances. Islam

Robert Carle

2008-01-01

12

Fe XVI radiative rates (Diaz+, 2013)  

NASA Astrophysics Data System (ADS)

Accurate theoretical energy level, lifetime, and transition probability calculations of core-excited Fe XVI were performed employing the relativistic Multireference Moller-Plesset perturbation theory. In these computations the term energies of the highly excited n<=5 states arising from the configuration 1s22sk2pm3lpnl'q, where k+m+p+q=9, l<=3 and p+q<=2 are considered, including those of the autoionizing levels with a hole-state in the L-shell. All even and odd parity states of sodium-like iron ion were included for a total of 1784 levels. Comparison of the calculated L-shell transition wavelengths with those from laboratory measurements shows excellent agreement. Therefore, our calculation may be used to predict the wavelengths of as of yet unobserved Fe XVI, such as the second strongest 2p-3d Fe XVI line, which has not been directly observed in the laboratory and which blends with one of the prominent Fe XVII lines. (2 data files).

Diaz, F.; Vilkas, M. J.; Ishikawa, Y.; Beiersdorfer, P.

2013-08-01

13

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...

14

EDITORIAL: XVI Brazilian Colloquium on Orbital Dynamics  

NASA Astrophysics Data System (ADS)

The XVI Brazilian Colloquium on Orbital Dynamics was held from 26–30 November 2012, at the Biazi Grand Hotel, Serra Negra, São Paulo, Brazil. The Brazilian Colloquia on Orbital Dynamics are scientific events that occur bi-annually and are designed to develop those areas of research in celestial mechanics, orbital dynamics, planetary science, fundamental astronomy, aerospace engineering, and nonlinear systems and chaos. The meeting has been held for 30 years and it brings together researchers, professors and students from South American and also from other continents. Acknowledgements National Council for Scientific and Technological Development – CNPq Coordination for the Improvement of Higher Level – CAPES São Paulo Research Foundation - FAPESP

de Melo, Cristiano F.; Macau, Elbert E. N.; Prado, Antonio B. A.; Hetem Jnr, Annibal

2013-10-01

15

Thermodynamic properties by non-calorimetric methods. Final report  

SciTech Connect

This research program provided a valuable complement to the experimental programs currently in progress at NIPER for the Advanced Research and Technology Development (AR and TD) and Advanced Exploration and Process Technology (AEPT) divisions of the Department of Energy. These experimental programs are focused on the calorimetric determination of thermodynamic properties of key polynuclear heteroatom-containing aromatic molecules. The project for the Office of Energy Research focused on the non-calorimetric determination of thermodynamic properties through the extension of existing correlation methodologies and through molecular spectroscopy with statistical mechanics. The paper discusses the following studies: Group-contribution approach for polycyclic aromatic hydrocarbons (naphthalene, phenanthrene, anthracene, pyrene, 3-methylphenanthrene, benzoquinolines, biphenyl/hydrogen system); Group-contribution approach for key monocyclic organic compounds; Molecular spectroscopy and statistical mechanics; and Thermophysical property correlations.

Steele, W.V.; Chirico, R.D.; Collier, W.B.; Strube, M.M.; Klots, T.D. [IIT Research Inst., Chicago, IL (United States)]|[National Inst. for Petroleum and Energy Research, Bartlesville, OK (United States)

1992-12-31

16

Pope Benedict XVI: a cautious approach to Middle East peace  

Microsoft Academic Search

Pope Benedict XVI came to the papacy with a very limited track record in terms of Catholic–Jewish relations generally speaking and virtually no public perspective on political issues related to the ongoing Israeli–Palestinian conflict. Since assuming the papacy he has addressed the Middle East political conflict only on a few occasions save for his trip to the region where he

J. T. Pawlikowski

2010-01-01

17

Benedict XVI, the Jewish people and the State of Israel  

Microsoft Academic Search

Benedict XVI has had to contend with invidious comparisons to his predecessor from the outset of his pontificate and this has been reflected in Jewish attitudes towards him as well. At the same time a selective loss of memory has occurred in relation to Pope John Paul II. By examining the documents and initiatives of Cardinal Ratzinger, as well as

David Rosen

2010-01-01

18

POPE BENEDICT XVI'S AFRICA VISIT AND THE CONDOM DEBATE  

Microsoft Academic Search

On Monday, 23 March, Pope Benedict XVI brought his seven-day maiden voyage to Africa to an end. Prior to boarding his plane to Rome at Luanda airport, he reiterated the message he had consistently delivered during his visit, calling on those in public office to fight poverty, corruption and violent conflicts for the sake of the common good, not out

Brian Lewis

19

Pope Benedict XVI's Summorum Pontificum: Reconciling Conflicting Values  

Microsoft Academic Search

This article examines the content of Pope Benedict XVI's Summorum Pontificum and his accompanying Letter to the Bishops and interprets them as a bold attempt to bring liturgical peace to the Catholic Church by freeing the “Tridentine” Latin Mass for general use and promoting internal reconciliation by reconciling theological values which have been at variance since Vatican II. It also

Steven A. Kiczek

2009-01-01

20

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

21

A calorimetric probe for plasma diagnostics.  

PubMed

A calorimetric probe for plasma diagnostics is presented, which allows measurements of the power taken by a test substrate. The substrate can be biased and used as an electric probe in order to obtain information about the composition of the total heating power. A new calibration technique for calorimetric probes, which uses monoenergetic electrons at low pressure, has been developed for an improved accuracy. The use of the probe is exemplified with an experiment where both energetic neutral atoms and ions heat the test substrate. PMID:20192493

Stahl, Marc; Trottenberg, Thomas; Kersten, Holger

2010-02-01

22

Calorimetric Analysis of the Plasma Proteome  

PubMed Central

The plasma proteome is a complex mixture of over 3000 proteins that has been routinely exploited by physicians for clinical diagnostic assays. More recently, the low abundance region of the proteome has been examined for potential biomarkers of disease. A novel calorimetric assay has been developed that exploits a new physical basis with which to interrogate the plasma proteome. This section provides a brief overview of the use of the plasma proteome in clinical diagnosis and biomarker discovery and then introduces the new calorimetric assay. Some initial results are reported that indicate the potential clinical utility of the assay.

Garbett, Nichola C.; Miller, James J.; Jenson, A. Bennett; Chaires, Jonathan B.

2009-01-01

23

Calorimetric analysis of the plasma proteome.  

PubMed

The plasma proteome is a complex mixture of more than 3,000 proteins that has routinely been exploited by physicians for clinical diagnostic assays. More recently, the low-abundance region of the proteome has been examined for potential biomarkers of disease. A calorimetric assay has been developed that exploits a new physical basis with which to interrogate the plasma proteome. This article provides a brief overview of the use of the plasma proteome in clinical diagnosis and biomarker discovery and then introduces the new calorimetric assay. Some initial results are reported that indicate the potential clinical utility of the assay. PMID:18061844

Garbett, Nichola C; Miller, James J; Jenson, A Bennett; Chaires, Jonathan B

2007-11-01

24

76 FR 45309 - Social Security Ruling 11-1p; Titles II and XVI: Procedures for Handling Requests To File...  

Federal Register 2010, 2011, 2012, 2013

...XVI: Procedures for Handling Requests To File Subsequent Applications for Disability...procedures for handling your request to file a disability claim when you have a pending...XVI: Procedures for Handling Requests To File Subsequent Applications for...

2011-07-28

25

Transient calorimetric diagnostics for plasma processing  

NASA Astrophysics Data System (ADS)

This paper reports on an improvement of the calorimetric method for the determination of energy fluxes from plasma towards substrates by using a transient technique. It provides a short overview of the traditional method used for characterization of plasma-wall-interactions during plasma processing. The mathematical framework of the method and possible implications are discussed. It is shown how the method can be improved to obtain additional and detailed information about the energy influx in a shorter measurement time. For this purpose, the probe bias (if applied), which has commonly been kept constant is varied like in Langmuir probe measurements. The experimental validation of the theoretical considerations emphasizes the potential of the method for control in plasma processing. The possibility how the passive calorimetric probe can be used in continuous measurements for process monitoring without any feedback loops used by other probes, is finally discussed.

Bornholdt, Sven; Kersten, Holger

2013-08-01

26

Ultra-Responsive Thermal Sensors for the Detection of Explosives Using Calorimetric Spectroscopy (CalSpec)  

SciTech Connect

We have developed a novel chemical detection technique based on infrared micro-calorimetric spectroscopy that can be used to identify the presence of trace amounts of very low vapor pressure target compounds. Unlike numerous recently developed low-cost sensor approaches, the selectivity is derived from the unique differential temperature spectrum and does not require the questionable reliability of highly selective coatings to achieve the required specificity. This is accomplished by obtaining the infrared micro-calorimetric absorption spectrum of a small number of molecules absorbed on the surface of a thermal detector after illumination through a scanning monochromator. We have obtained infrared micro-calorimetric spectra for explosives such as TNT over the wavelength region 2.5 to 14.5 Mu-m. Thus both sophisticated and relatively crude explosive compounds and components are detectable with these ultra-sensitive thermal-mechanical micro-structures. In addition to the above mentioned spectroscopy technique and associated data, the development of these advanced thermal detectors is also presented in detail.

Datskos, P.G.; Datskou, I.; Marlar, T.A.; Rajic, S.

1999-04-05

27

Calorimetric investigation of the tensile deformation of polyethylene  

Microsoft Academic Search

A calorimetric apparatus for investigating the thermal effects associated with tensile deformation is described. The results of calorimetric measurements made on high- and low-density polyethylene during the deformation process are presented. It is shown that on the interval of strains and loading rates investigated the deformation of polyethylene is energetic in character.

Yu. M. Molchanov; G. A. Molchanova

1970-01-01

28

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

Microsoft Academic Search

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

Lizbeth O Cisneros; William J Rogers; M. Sam Mannan

2001-01-01

29

Pope Benedict XVI to visit Notre Dame on 18th July 2008  

Microsoft Academic Search

The University of Notre Dame Australia is honoured to announce that His Holiness Pope Benedict XVI will visit the University’s Darlinghurst Campus, Sydney on 18 July.\\u000aThe Holy Father has requested to meet young people at risk of alcohol and substance abuse, homelessness and other forms of disadvantage. The University is privileged to host this occasion.\\u000aPope Benedict XVI will

Hayden Ramsay

2008-01-01

30

Acyclic diterpene glycosides, capsianosides VIII, IX, X, XIII, XV and XVI from the fruits of Paprika Capsicum annuum L. var. grossum BAILEY and Jalapeño Capsicum annuum L. var. annuum.  

PubMed

Paprika and Jalapeño are used as vegetables and spices. We have obtained six new acyclic diterpene glycosides, called capsianosides XIII (2), XV (3), IX (4), XVI (5), X (6) and VIII (7) together with known capsianoside II (1) from the fruits of the Paprika and Jalapeño. The structures of these compounds have been elucidated by the (1)H- and (13)C-NMR spectra and two-dimensional NMR methods. PMID:17015971

Lee, Jong-Hyun; Kiyota, Naoko; Ikeda, Tsuyoshi; Nohara, Toshihiro

2006-10-01

31

The calorimetric criterion for a two-state process revisited.  

PubMed Central

The "calorimetric criterion" is one of the important experimental approaches for determining whether protein folding is an "all-or-none" two-state transition (i.e., whether intermediates are present at equilibrium). The calorimetric criterion states that the equivalence of the "measured" calorimetric enthalpy change and the effective two-state van't Hoff enthalpy change demonstrates that there is a two-state transition. This paper addresses the essential question of whether the calorimetric criterion is a necessary and sufficient condition for a two-state process and shows that it is necessary but not sufficient by means of specific examples. Analysis of simple models indicates that the heat capacity curve, regardless of whether it originates from a two-state process or not, can always be decomposed in such a way that the calorimetric criterion is satisfied. Exact results for a three-state model and a homopolymer tetramer demonstrate that the deviation from the calorimetric criterion is not simply related to the population of intermediate states. Analysis of a three-helix bundle protein model, which has a two-state folding from a random coil to ordered (molten) globule, shows that the calorimetric criterion may not be satisfied if the standard linear interpolation of baselines (weighted or unweighted) is employed. A specific example also suggests that the more recently introduced deconvolution method is not necessarily better than the simple calorimetric criterion for distinguishing a two-state transition from a three-state transition. Although the calorimetric criterion is not a sufficient condition for a two-state process, it is likely to continue to be of practical utility, particularly when its results are shown to be consistent with those from other experimental methods.

Zhou, Y.; Hall, C. K.; Karplus, M.

1999-01-01

32

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

33

Calorimetric study of melted DNA glass  

NASA Astrophysics Data System (ADS)

In this work we report a detailed calorimetric study using differential scanning calorimetry (DSC) of the glassy behaviour of films made from DNA fibers. We show that after the first irreversible thermal denaturation of the molecules when the sample is reiteratively heated, it reaches a disordered state in which it presents a typical glass behaviour during successive cooling and heating scans. Furthermore, we have investigated the properties of these DNA films in two series of experiments, a slow cooling at different rates followed by a DSC scan upon heating, and ageing at a temperature below the glass transition. Introducing the fictive temperature to characterise the glass allows us to derive quantitative information on the relaxations of the DNA films, in particular to evaluate their enthalpy barrier. A comparison with similar ageing studies on PVAc highlights some specificities of the DNA samples.

Valle-Orero, Jessica; Garden, Jean-Luc; Richard, Jacques; Wildes, Andrew; Peyrard, Michel

2013-02-01

34

Calorimetric investigations of calcium phosphate precipitation  

NASA Astrophysics Data System (ADS)

The kinetics of the early stages of crystallization of calcium phosphate under different initial solution compositions have been studied by calorimetric and light scattering methods. It is found that the total heat of formation of calcium phosphate is negative and depends on the molar ratio Ca/P and the initial pH of the mixture. At initial pH 7.40 and pH 8.62, there are relatively strong repeated endothermic heat effects. The character of this heat conversion is not clear. The light scattering studies do not rule out the possibility of the existence of Ca 4 H(PO 4 ) 3 ·½H 2 O (OCP) crystals in this region at these initial solution pH's rather than Ca 5 (PO 4 ) 3 OH (HAP) and CaHPO 4 ·2H 2 O (DCPD) expected to crystallize at initial higher and lower values of pH, respectively.

Kibalczyc, Wiktor

1987-04-01

35

Calorimetric sensors for energy deposition measurements  

SciTech Connect

A calorimetric sensor with several novel design features has been developed. These sensors will provide an accurate sampling of thermal power density and energy deposition from proton beams incident on target components of accelerator-based systems, such as the Accelerator Production of Tritium Project (APT) and the Spallation Neutron Source (SNS). A small, solid slug (volume = 0.347 cc) of target material is suspended by kevlar fibers and surrounded by an adiabatic enclosure in an insulating vacuum canister of stainless steel construction. The slug is in thermal contact with a low-mass, calibrated, 100-k{Omega} thermistor. Power deposition caused by the passage of radiation through the slug is calculated from the rate of temperature rise of the slug. The authors have chosen slugs composed of Pb, Al, and LiAl.

Langenbrunner, J.; Cooper, R. [Bechtel Nevada, Los Alamos, NM (United States); Morgan, G. [Los Alamos National Lab., NM (United States)] [and others

1998-12-31

36

Calorimetric investigations of liquid Bi–In–Zn alloys  

Microsoft Academic Search

The integral enthalpies of mixing of liquid Bi–In–Zn alloys were determined at 500°C by a drop calorimetric technique using a Calvet-type microcalorimeter. The ternary liquid miscibility gap in the Bi–In–Zn system at 500°C was confirmed and determined by the calorimetric method for the first time. The three binary interaction parameters and the ternary interaction parameters were optimized based on the

Zuoan Li; Sabine Knott; Adolf Mikula

2007-01-01

37

40 CFR Appendix Xvi to Part 86 - Pollutant Mass Emissions Calculation Procedure for Gaseous-Fueled Vehicles and for Vehicles...  

Code of Federal Regulations, 2013 CFR

...CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED) Pt. 86, App. XVI Appendix XVI to Part...44.00995 CH2.658 * 14.6903 * Average ratio of Hydrogen to carbon atoms in HD-5 fuel. (B) C3 H8...

2013-07-01

38

A calorimetric method to determine water activity.  

PubMed

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, MgCl(2), NaBr, NaCl, KCl, KNO(3), and K(2)SO(4)) 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. PMID:22129000

Björklund, Sebastian; Wadsö, Lars

2011-11-01

39

Calorimetric study of peroxycarboxylic ester synthesis.  

PubMed

Exothermic reactions involving organic peroxides carry a high potential hazard and must be considered with care. A safe handling requires, among others, the assessment of thermal process safety, for which safety characteristics like overall heat production and the resulting adiabatic temperature rise are essential. The article presents the results of the calorimetric investigation of the synthesis of four peroxycarboxylic esters, three tert-Butyl and one tert-Amyl peroxycarboxylic ester. In the two-step synthesis the second one clearly shows the higher exothermic potential. The overall heat production lies in the range of 126-135 kJ/mol and is nearly independent of the carboxylic acid residual in the tert-Butyl peroxycarboxylic ester. The calculated adiabatic temperature rise is 70-80K. Influence of temperature and feed rate on the heat generation is discussed for one species. A grading of the synthesis with respect to temperature levels according to the criticality classes by Stoessel leads to the most critical for an exothermic reaction. PMID:18722058

Fritzsche, L; Knorr, A

2008-07-15

40

Adaptive measurement control for calorimetric assay  

SciTech Connect

The performance of a calorimeter is usually evaluated by constructing a Shewhart control chart of its measurement errors for a collection of reference standards. However, Shewhart control charts were developed in a manufacturing setting where observations occur in batches. Additionally, the Shewhart control chart expects the variance of the charted variable to be known or at least well estimated from previous experimentation. For calorimetric assay, observations are collected singly in a time sequence with a (possibly) changing mean, and extensive experimentation to calculate the variance of the measurement errors is seldom feasible. These facts pose problems in constructing a control chart. In this paper, the authors propose using the mean squared successive difference to estimate the variance of measurement errors based solely on prior observations. This procedure reduces or eliminates estimation bias due to a changing mean. However, the use of this estimator requires an adjustment to the definition of the alarm and warning limits for the Shewhart control chart. The authors propose adjusted limits based on an approximate Student`s t-distribution for the measurement errors and discuss the limitations of this approximation. Suggestions for the practical implementation of this method are provided also.

Glosup, J.G.; Axelrod, M.C.

1994-10-01

41

Intermetallic Compounds of Extreme Stability.  

National Technical Information Service (NTIS)

The ideas of the Engel-Brewer Correlation have been used to choose a class of intermetallic compounds as possible refractory materials. Calorimetric experiments clearly show that ZrPt3 and HfPt3 are the most thermodynamically stable intermetallics known. ...

J. Carloni J. Wu P. Ficalora V. ikrishnan

1971-01-01

42

Ungulates and the Middle-to-Upper Paleolithic transition at Grotte XVI (Dordogne, France)  

Microsoft Academic Search

Grotte XVI (Dordogne, France) contains a rich archaeological sequence that begins during the Mousterian and continues through the Magdalenian and includes Châtelperronian and early Aurignacian assemblages. Analyses of the ungulates from this site show no significant change in skeletal part representation, butchering intensity (as measured by cut mark numbers and placement), degree of bone fragmentation, and intensity of carnivore damage

Donald K. Grayson; Françoise Delpech

2003-01-01

43

A TEMPORAL MAP IN GEOSTATIONARY ORBIT: THE COVER ETCHING ON THE EchoStar XVI ARTIFACT  

SciTech Connect

Geostationary satellites are unique among orbital spacecraft in that they experience no appreciable atmospheric drag. After concluding their respective missions, geostationary spacecraft remain in orbit virtually in perpetuity. As such, they represent some of human civilization's longest lasting artifacts. With this in mind, the EchoStar XVI satellite, to be launched in fall 2012, will play host to a time capsule intended as a message for the deep future. Inspired in part by the Pioneer Plaque and Voyager Golden Records, the EchoStar XVI Artifact is a pair of gold-plated aluminum jackets housing a small silicon disk containing 100 photographs. The Cover Etching, the subject of this paper, is etched onto one of the two jackets. It is a temporal map consisting of a star chart, pulsar timings, and other information describing the epoch from which EchoStar XVI came. The pulsar sample consists of 13 rapidly rotating objects, 5 of which are especially stable, having spin periods <10 ms and extremely small spin-down rates. In this paper, we discuss our approach to the time map etched onto the cover and the scientific data shown on it, and we speculate on the uses that future scientists may have for its data. The other portions of the EchoStar XVI Artifact will be discussed elsewhere.

Weisberg, Joel M., E-mail: jweisber@carleton.edu [Department of Physics and Astronomy, Carleton College, Northfield, MN 55057 (United States); Paglen, Trevor, E-mail: trevor@paglen.com

2012-10-01

44

Benedict XVI and Islam: Indonesian Public Reactions to the Regensburg Address  

Microsoft Academic Search

This paper examines the responses of the Indonesian public sphere in the reform era to Pope Benedict XVI's call for interfaith dialogue in his speech made in Regensburg on 12 September 2006. It explores five op-ed (opinion and editorial) columns published by Indonesian newspapers (Republika, Harian Pikiran Rakyat, The Jakarta Post and Gatra), a piece posted by the online Wahid

Al Makin

2009-01-01

45

A DIPLOMACY OF CANDOR: POPE BENEDICT XVI ON THE GLOBAL STAGE  

Microsoft Academic Search

In his time in the papacy, Pope Benedict XVI has displayed a straightforward style of diplomacy, viewing it as a safeguard to the common interests of humankind. His initiatives to date demonstrate five key elements of this diplomacy: respecting objective moral truth, facilitating practical inter-faith dialogue, building realistic bridges, intervening for peace, and prioritizing peace over markets. Each of these

Bernard J. OConnor

2006-01-01

46

Technology and Freedom: Pope Benedict XVI on Faith, Reason, and Politics  

Microsoft Academic Search

Pope Benedict XVI connects the problem of technology to the question of how human beings have chosen to employ their reason, both in their encounter with faith and in their pursuit of human freedom. His analysis involves a penetrating study of the history of modern thought, a history he distinguishes from the practice of classical political philosophy. Benedict's willingness to

Patrick N. Cain

2012-01-01

47

Pope Benedict XVI within the context of Israel and Holy See relations  

Microsoft Academic Search

The pontificate of Benedict XVI is undoubtedly shaped by his personality as a profound thinker and one who is much more a philosopher than a politician. Management seems not to be his trade. With his intellectual mind he shuns anything that smells of populism. The mass media has an inherent difficulty in placing him within their traditional parameters. The paradigm

Mordechay Lewy

2010-01-01

48

Education as a path to love: A leadership perception of Benedict XVI's challenge to Catholic education  

Microsoft Academic Search

This qualitative study presents a renewed definition of Catholic education based on the theological notion of love-caritas-agape which Benedict XVI describes in the encyclical Deus Caritas Est (2005). The traits of love illustrated in the first part of the encyclical have been developed within a model of education enriched by the contributions of contemporary scholars as Bernard Lonergan (philosophy of

Stefano Del Bove

2008-01-01

49

Sensitivity and systematics of calorimetric neutrino mass experiments  

SciTech Connect

A large calorimetric neutrino mass experiment using thermal detectors is expected to play a crucial role in the challenge for directly assessing the neutrino mass. We discuss and compare here two approaches for the estimation of the experimental sensitivity of such an experiment. The first method uses an analytic formulation and allows to obtain readily a close estimate over a wide range of experimental configurations. The second method is based on a Montecarlo technique and is more precise and reliable. The Montecarlo approach is then exploited to study some sources of systematic uncertainties peculiar to calorimetric experiments. Finally, the tools are applied to investigate the optimal experimental configuration of the MARE project.

Nucciotti, A.; Cremonesi, O.; Ferri, E. [Dipartimento di Fisica, Universita di Milano Bicocca and INFN Sezione di Milano-Bicocca Piazza della Scienza, 3, 20126 Milano (Italy)

2009-12-16

50

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

51

Thermodynamic properties by non-calorimetric methods. Progress report, August 1, 1988--July 31, 1989  

SciTech Connect

This three year research program provides a valuable complement to the experimental programs currently in progress at NIPER for the Advanced Research and Technology Development (AR and TD) and Advanced Exploration and Process Technology (AEPT) divisions of the Department of Energy. These experimental programs are focused on the calorimetric determination of thermodynamic properties of key polynuclear heteroatom-containing aromatic molecules. This project for the Office of Energy Research focuses on the non-calorimetric determination of thermodynamic properties through the extension of existing correlation methodologies and through molecular spectroscopy with statistical mechanics. The paper discusses progress in three areas: (1) Improvement of thermochemical and thermophysical property predictions via enhancement of group-contribution methods using two approaches, namely, development and improvement of group-contribution parameters via correlations involving the expanded modern thermodynamics data base and development of group-contribution parameters via molecular spectroscopy and statistical mechanics of key monocyclic organic compounds; (2) Molecular spectroscopy and statistical mechanics: equipment development and developments in interpretation and assignment of spectra; and (3) Thermophysical property correlations.

Steele, W.V.; Chirico, R.D.; Collier, W.B.; Strube, M.M. [IIT Research Inst., Chicago, IL (United States)]|[National Inst. for Petroleum and Energy Bartlesville, OK (United States)

1989-12-31

52

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

Federal Register 2010, 2011, 2012, 2013

...Security Ruling, SSR 13-2p; Titles II and XVI: Evaluating Cases Involving Drug Addiction and Alcoholism (DAA); Correction...first column, question 8. ``What evidence do we need in cases involving DAA?'', a., italicize the subheading...

2013-03-22

53

20 CFR 416.572 - Are title II and title VIII benefits subject to adjustment to recover title XVI overpayments?  

Code of Federal Regulations, 2013 CFR

...416.572 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL...title XVI overpayments from benefits payable to you under title II or title VIII of the Social Security Act. (2) Benefits payable. For...

2013-04-01

54

20 CFR 408.930 - Are title II and title XVI benefits subject to adjustment to recover title VIII overpayments?  

Code of Federal Regulations, 2013 CFR

... Section 408.930 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS...under title II or title XVI of the Social Security Act. (2) Benefits payable. For purposes of...

2013-04-01

55

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

Federal Register 2010, 2011, 2012, 2013

...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

56

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

Federal Register 2010, 2011, 2012, 2013

...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

57

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

Federal Register 2010, 2011, 2012, 2013

...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

58

Calorimetric Low Temperature Detectors for Heavy Ion Physics  

Microsoft Academic Search

Calorimetric low temperature detectors have the potential to become powerful tools for applications in many fields of heavy ion physics. A brief overview of heavy ion physics at present and at the next generation heavy ion facilities is given with a special emphasis on the conditions for heavy ion detection and the potential advantage of cryogenic detectors for applications in

P. Egelhof; S. Kraft-Bermuth

59

Isoperibolic Calorimetric Cell with Electronic Integrator Circuit for Temperature Measurement  

Microsoft Academic Search

An isoperibolic calorimetric cell, formed with double plastic insulation, is connected to a conventional Dewar glass. The cell has a lid on which are placed an electronic thermometer and an electric resistor to provide the cell with specific quantities of electrical work.The thermometer, built with an LM35 integrator circuit, presents an output potential signal which is proportional to the temperature

Paola Martínez; Liliana Giraldo; Edgar Vargas; Juan Carlos Moreno

2005-01-01

60

Calorimetric insights into the synthesis of templated materials  

Microsoft Academic Search

Major recent advancesIn situ calorimetric studies of zeolite synthesis have been performed under conditions where the growing templated zeolite remains in contact with its aqueous solution. Nanoparticles form first, then aggregate to form the zeolite. As surface area decreases, hydroxyl ions begin to desorb from the shrinking surface of the growing crystals, raising the pH, causing a shift from exothermic

Alexandra Navrotsky

2005-01-01

61

Calorimetric Thermometry of Meteoritic Troilite: Early Reconnaissance  

NASA Astrophysics Data System (ADS)

Troilite (FeS) exhibits two solid-state phase transformations, which, according to conventional thermodynamic literature [1,2], occur at 411 +- 3 K (alpha/beta) and 598 +- 3 K (beta/gamma). In principal, the thermal history of a particular troilite sample might be expected to impart structural or strain characteristics that could be measured upon experimental inducement of the phase transformations. To investigate that possibility, we applied differential scanning calorimetry (DSC) to determine the temperatures and enthalpy changes for phase transitions of various troilite samples subjected to controlled heating [3]. Post-heating residues were prepared as polished grain mounts and petrologically characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometry (EDS). Troilite grains separated from the Mundrabilla (octahedrite), PAT91501 (L7 chondrite), and EET83213 (L3 chondrite) meteorites were compared with terrestrial troilite from an ultramafic complex in Del Norte Co., California. Both the alpha/beta and beta/gamma transitions were easily measured by DSC applied to samples on the order of 5 milligrams. Extrapolated-onset temperatures (the DSC approximation of equilibrium transition temperatures) for the alpha/beta transition display a systematic progression as follows: Mundrabilla, PAT91501, EET83213, Del Norte (Fig. 1). At least for Mundrabilla, PAT91501, and Del Norte, there also exists an apparent correlation of transition enthalpy with onset temperature (Fig. 1). (Enthalpy measurements for EET83213 troilite were systematically low, by dilution effects from admixed Ni-Fe metal, and require correction before such comparison.) Although Mundrabilla troilite contains on the order of 1 wt% Cr, and some grains of PAT91501 troilite contain on the order of 1 wt% Ni, it is doubtful that compositional differences can fully account for the measured differences in thermodynamic properties. Instead, it is likely that first-order differences are the consequence of different thermal histories. Multiple samples of Del Norte troilite were used to determine the influence of laboratory-scale thermal histories on DSC signatures by heating and cooling each sample under different programmed conditions. In reconnaissance experiments, maximum temperature achieved during heat treatment appears to be more influential than does either the time maintained at temperature or the heating/cooling rate. The experimentally measured alpha/beta onset temperature shows a systematic decline with maximum temperature achieved during prior heating, suggesting that high onset temperatures are indicative of low maximum temperatures in the natural histories of the troilite samples. That trend is at least qualitatively consistent with the petrologic rankings of the meteorites in which troilite from the relatively unmetamorphosed L3 chondrite shows a higher onset temperature than does troilite from either the highly metamorphosed L7 chondrite or the octahedrite. Additional work should define the limits of a quantitative calibration that might ultimately permit derivation of meteorite thermal histories by calorimetric thermometry of troilite. Samples were kindly provided by E. R. D. Scott (Mundrabilla), C. B. Moore (Del Norte), and the Meteorite Working Group (PAT91501; EET83213 powder from E. Jarosewich). References: [1] Chase M. W. Jr. et al. (1985) JANAF Thermochemical Tables, 3rd ed., 1194. [2] Robie R. A. et al. (1979) Geol. Surv. Bull. 1452, 125. [3] Allton J. H. and Gooding J. L. (1993) LPS XXIV, 21-22. Fig. 1, which appears here in the hard copy, shows the thermodynamics of troilite alpha/beta phase transformations measured by DSC during first-heat cycles.

Allton, J. H.; Wentworth, S. J.; Gooding, J. L.

1993-07-01

62

A solution calorimetric study on stability of superconducting YBa2Cu3O6.91  

NASA Astrophysics Data System (ADS)

The enthalpies of solution of 90K superconducting YBa2Cu3O6.91 in 1N HCl aqueous solution has been measured calorimetrically at 298K. In combination with auxilliary values from literatures, the standard enthalpies of formation of YBa2Cu3O6.91 has been derived. The value of ?fHm°(YBa2Cu3O6.91) is estimated 3027 +/- ? kJ/mol (? is from the auxilliary values and experimental error and is less than 5). By use of entropy value of YBa2Cu3O6.91. we found an increase in the stability of the compound relative to the parent oxides (Y2O3, BaO and CuO) from 300K up to 1156K. These results explain why the superconducting YBC oxide has a tendency to decompose above 1200K in the thermodynamic view point.

Kang, Seong-Gu; Choy, Jin-Ho; Jung, Duk-Young; Won Choi, Q.

1991-12-01

63

Thermodynamic investigation of a solid–solid phase change material: 2Amino2-methyl-1,3-propanediol by calorimetric methods  

Microsoft Academic Search

An important solid–solid phase change heat storage material (PCM) 2-amino-2-methyl-1,3-propanediol was investigated by calorimetric methods. The molar heat capacities of the compound were measured in the temperature range from 78 to 405K by means of a small sample automated adiabatic calorimeter. A solid–solid and solid–liquid phase transitions were found at T=351.598K and 380.633K, respectively, from the experimental Cp–T curve. The

Tong Bo; Tan Zhi-Cheng; Liu Rui-Bin; Meng Chang-Gong; Zhang Jing-Nan

2010-01-01

64

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

65

Calorimetric low temperature detectors for mass identification of heavy ions  

Microsoft Academic Search

The energy sensitive detection of heavy ions with calorimetric low temperature detectors (CLTDs) is investigated for the energy range E=0.1-1 MeV\\/u, commonly used for accelerator mass spectrometry (AMS). Such measurements complement earlier investigations [1, 2] at higher energies (E=5-300 MeV\\/u) where an energy resolution of DeltaE\\/E=1-2×10-3 was obtained for various ion species. The detectors used consist of sapphire absorbers and

S. Kraft; A. Bleile; P. Egelhof; R. Golser; O. Kisselev; W. Kutschera; H. J. Meier; A. Priller; A. Shrivastava; P. Steier; C. Vockenhuber; M. Weber

2002-01-01

66

Calorimetric studies of isothermal curing of phase separating epoxy networks  

Microsoft Academic Search

To get a better understanding of the curing process of multi-component thermosets differential scanning calorimetric (DSC) and temperature modulated DSC (TMDSC) measurements were performed during isothermal curing of semi-interpenetrating polymer networks (semi-IPNs) with amounts of 10 or 20wt.% of linear polymer and of the corresponding pure networks at temperatures between 333 and 393K. The network component consists of diglycidylether of

W. Jenninger; J. E. K. Schawe; I. Alig

2000-01-01

67

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

68

Regulators of cell division in plant tissues. XVI  

Microsoft Academic Search

[3H]Zeatin was supplied through the transpiration stream to radish (Raphanus sativus L.) seedlings with roots excised. Formation of dihydrozeatin was not detected but numerous other metabolites were formed, including adenine, adenosine, AMP, zeatin riboside and zeatin riboside-5'-monophosphate. However, in labelled seedlings which had been left in water for 15 h, an unknown compound (raphanatin) was the dominant metabolite and accounted

C. W. Parker; D. S. Letham

1973-01-01

69

Collagen XVI induces formation of focal contacts on intestinal myofibroblasts isolated from the normal and inflamed intestinal tract.  

PubMed

In Crohn's disease (CD) the stress-shield of intestinal subepithelial myofibroblasts (ISEMF) provided by intact tissue is disturbed due to inflammation and thus, cells start with remodelling activities. This is characterized by increased numbers of collagen-producing ISEMF causing an uncontrolled, irreversible wound-healing response to the chronic inflammation of the gastrointestinal tract. Reconstitution of the original ECM leads ISEMF to exit this cycle. In contrast, during fibrosis, ISEMF persist. It is known that ISEMF produce and deposit collagen types I, III, IV and V; however synthesis and the role of fibrillar peripheral molecules like collagen type XVI have not been addressed yet. Here, we have analyzed the distribution of collagen XVI in the normal and inflamed bowel wall, its gene and protein expression by ISEMF of different inflammation stages, the cell-matrix interactions in different phases of the inflammatory process and their effect on cell spreading, proliferation and migration. Collagen XVI is deposited in the submucosa of the intestinal wall where it co-localizes with fibrillin-1 and integrin alpha1. ISEMF reveal increasing gene and protein expression of collagen XVI concurrent to increasing inflammation. ISEMF reveal more mature focal adhesion contacts when seeded on collagen XVI resulting in an extensive cell spreading. This involves recruitment of alpha1beta1 integrin, which shows increased cell surface expression on ISEMF in late stages of inflammation. We assume that collagen XVI promotes persistence of ISEMF in the normal and, even stronger in the inflamed bowel wall by stabilizing focal adhesion contacts via cell-matrix interaction preferentially through recruitment of alpha1ss1 integrin into the tips of the focal adhesion contacts. PMID:19931388

Ratzinger, Sabine; Eble, Johannes A; Pasoldt, Anja; Opolka, Alfred; Rogler, Gerhard; Grifka, Joachim; Grässel, Susanne

2009-11-18

70

Calorimetric and computational study of indanones.  

PubMed

Condensed phase standard (p degrees = 0.1 MPa) molar enthalpies of formation for 1-indanone, 2-indanone, and 1,3-indandione were derived from the standard molar enthalpies of combustion, in oxygen, at T = 298.15 K, measured by static bomb combustion calorimetry. The standard molar enthalpies of sublimation for 1-indanone and 2-indanone, at T = 298.15 K, were measured both by correlation-gas chromatography and by Calvet microcalorimetry leading to a mean value for each compound. For 1,3-indandione, the standard molar enthalpy of sublimation was derived from the vapor pressure dependence on temperature. The following enthalpies of formation in gas phase, at T = 298.15 K, were then derived: 1-indanone, -64.0 +/- 3.8 kJ mol(-1); 2-indanone, -56.6 +/- 4.8 kJ mol(-1); 1,3-indandione, -165.0 +/- 2.6 kJ mol(-1). The vaporization and fusion enthalpies of the indanones studied are also reported. In addition, theoretical calculations using the density functional theory with the B3LYP and MPW1B95 energy functionals and the 6-311G** and cc-pVTZ basis sets have been performed for these molecules and the corresponding one-ring species to obtain the most stable geometries and to access their energetic stabilities. PMID:17929782

Matos, M Agostinha R; Miranda, Margarida S; Monte, Manuel J S; Santos, Luís M N B F; Morais, Victor M F; Chickos, James S; Umnahanant, Patamaporn; Liebman, Joel F

2007-10-11

71

A comprehensive set of UV and x-ray radiative transition rates for Fe XVI  

NASA Astrophysics Data System (ADS)

Sodium-like Fe XVI is observed in collisionally ionized plasmas such as stellar coronae and coronal line regions of active galactic nuclei including black hole-accretion disc environments. Given its recombination edge from neon-like Fe XVII at ~\\!25 Å, the Fe XVI bound-bound transitions lie in the soft x-ray and EUV (extreme ultraviolet) range. We present a comprehensive set of theoretical transition rates for radiative dipole allowed E1 transitions including fine structure for levels with nell(SLJ)<=10, ell<=9 using the relativistic Breit-Pauli R-matrix (BPRM) method. In addition, forbidden transitions of electric quadrupole (E2), electric octupole (E3), magnetic dipole (M1) and magnetic quadrupole (M2) type are presented for levels up to 5g(SLJ) from relativistic atomic structure calculations in the Breit-Pauli approximation using code SUPERSTRUCTURE. Some of the computed levels are autoionizing, and oscillator strengths among those are also provided. BPRM results have been benchmarked with the relativistic coupled cluster method and the atomic structure Dirac-Fock code GRASP. Levels computed with the electron collision BPRM codes in bound state mode were identified with a procedure based on the analysis of quantum defects and asymptotic wavefunctions. The total number of Fe XVI levels considered is 96, with 822 E1 transitions. Tabulated values are presented for the oscillator strengths f, line strengths S and Einstein radiative decay rates A. This extensive dataset should enable spectral modelings up to highly excited levels, including recombination-cascade matrices.

Nahar, S. N.; Eissner, W.; Sur, C.; Pradhan, A. K.

2009-03-01

72

Thermodynamic model for calorimetric and phase coexistence properties of coal derived fluids  

Microsoft Academic Search

The objective of this project is to develop a thermodynamic model for phase equilibria and calorimetric properties of coal derived fluids. A model for phase equilibria of coal derived liquids is already available. This model is to be extended to include calorimetric properties. The modification involves the use of the modified UNIFAC correlation with suitably regressed parameters, combined with an

Kabadi

1989-01-01

73

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

74

A no-calorimetric method for measuring SAR in MRI  

NASA Astrophysics Data System (ADS)

During an MR procedure, the patient absorbs a portion of the transmitted RF energy, which may result in tissue heating and other adverse effects, such as alterations in visual, auditory and neural functions. The Specific Absorption Rate (SAR), in W/kg, is the RF power absorbed per unit mass of tissue and is one of the most important parameters related with thermal effects and acts as a guideline for MRI safety. Strict limits to the SAR levels are imposed by patient safety international regulations (CEI - EN 60601 - 2 - 33) and SAR measurements are required in order to verify its respect. The recommended methods for mean SAR measurement are quite problematic and often require a maintenance man intervention and long stop machine. For example, in the CEI recommended pulse energy method, the presence of a maintenance man is required in order to correctly connect the required instrumentation; furthermore, the procedure is complex and requires remarkable processing and calculus. Simpler are the calorimetric methods, also if in this case long acquisition times are required in order to have significant temperature variations and accurate heat capacity knowledge (CEI - EN 60601 - 2 - 33). The phase transition method is a new no-calorimetric method to measure SAR in MRI which has the advantages to be very simple and to overcome all the typical calorimetric method problems. It does not require in gantry temperature measurements, any specific heat or heat capacity knowledge, but only mass and time measurement. On the other hand, it is necessary to establish if all deposited power SAR can be considered acquired and measured. In this paper, that will be shown.

Romano, Rocco; Acernese, Fausto; Barone, Fabrizio

2011-03-01

75

Low-temperature calorimetric evaluation of aluminum-lithium alloys  

NASA Astrophysics Data System (ADS)

Low temperature calorimetric measurements have been made on a series of binary aluminum alloys containing 1-10 at. % lithium. The heat capacity data are analyzed in terms of an electronic and a lattice contribution. Accordingly, the low level of lithium addition yields appreciable changes in the electronic density-of-states at Fermi level and the characteristic Debye temperature of lattice. These results reflect certain degrees of electron localization between aluminum and lithium atoms, providing a fundamental basis for solid solution strengthening in the lightweight materials with great potential in aerospace applications.

Wang, C. R.; Neeleshwar, S.; Chen, Y. Y.; Ho, J. C.

2003-12-01

76

Calorimetric determination of the enthalpy of formation for pyrophyllite  

NASA Astrophysics Data System (ADS)

A calorimetric study of the natural pyrophyllite was performed by high-temperature melt calorimetry on a Tian-Calvet calorimeter. Based on experimentally determined in this work for pyrophyllite and gibbsite, as well as previously obtained for corundum and quartz, the total value of the enthalpy increment for the sample heated from room temperature to 973 K and the enthalpy of dissolution at 973 K by Hess's law, the enthalpy of formation of pyrophyllite of Al2[(OH)2/Si4O10] composed of elements was calculated at 298.15 K: ?f H {el/o}(298.15 K) = -5639.8 ± 5.7 kJ/mol.

Ogorodova, L. P.; Kiseleva, I. A.; Mel'Chakova, L. V.; Vigasina, M. F.; Spiridonov, E. M.

2011-09-01

77

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

78

Novel micro-calorimetric spectroscopy for mine detection  

SciTech Connect

The authors have developed a novel micro-calorimetric spectroscopy technique that can be used in mine detection applications. In this technique target molecules are allowed to adsorb on the surface of sub-femtojoule sensitive micromechanical thermal detectors. The adsorption of molecules on the thermal detector surface causes a differential surface stress resulting in an initial trigger. By exposing each element in an array of thermal detectors to different photon wavelengths, an extremely sensitive and unique photothermal signature response can be obtained. The authors present their results on target chemicals adsorbed on the detector surface at sub-monolayer coverage levels. They will present infrared photothermal spectra for trace concentrations of diisopropyl methylphosphonate (DIMP), and trinitrotoluene (TNT) over the wavelength region 2.5 to 14.5 microns. They found that in the wavelength region 2.5 to 14.5 microns the photothermal spectra of DIMP and TNT exhibit a number of peaks and are in excellent agreement with infrared absorption spectra found in the literature. Chemical detectors based on micro-calorimetric spectroscopy can be used to sensitively sense small number of molecules adsorbed on a thermal detector surface. The photothermal signature resulting from photon irradiation can be used for improved chemical characterization.

Datskos, P.G. [Oak Ridge National Lab., TN (United States)]|[Univ. of Tennessee, Knoxville, TN (United States); Rajic, S.; Egert, C.M.; Datskou, I. [Oak Ridge National Lab., TN (United States)

1998-03-01

79

Low-temperature calorimetric properties of zinc ferrite nanoparticles  

NASA Astrophysics Data System (ADS)

Calorimetric measurements between 1 and 40 K by a thermal relaxation technique have been made on zinc ferrite nanoparticles prepared from an aerogel process. The expected ?-type heat-capacity peak near 10 K, which corresponds to a long-range antiferromagnetic transition in the bulk form of this material, is greatly suppressed. Broad peaks begin to prevail after the sample is annealed at 500 or 800 °C, but ball milling of the nanoparticles leads to almost complete disappearance of the low-temperature ordering. In all cases, calorimetrically based magnetic entropy at 40 K accounts for only a fraction of 2R ln(2S+1) with S=5/2 for Fe3+. These results are corroborated by magnetic data, which also indicate magnetic ordering at high temperatures. Such observations can be understood by considering the relative distribution of Fe3+ between two nonequivalent (A and B) sites in the spinel-type lattice. In particular, the as-prepared fine particles show large Fe3+ occupancy of the A sites, whereas these ions prefer the B sites in bulk zinc ferrite. Meanwhile, the lattice heat capacity is enhanced, yielding effective Debye temperatures of 225, 285, 345, and 360 K for the as-prepared, 500 °C-annealed, 800 °C-annealed, and ball milled sample, respectively, in contrast to 425 K for the bulk material.

Ho, J. C.; Hamdeh, H. H.; Chen, Y. Y.; Lin, S. H.; Yao, Y. D.; Willey, R. J.; Oliver, S. A.

1995-10-01

80

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

Federal Register 2010, 2011, 2012, 2013

...Notice of Social Security Ruling (SSR...of SSR 13-2p, in which we explain...XVI of the Social Security Act, and to the...determine disability in those claims. 20...policy, as set out in the Commissioner's...regulations, SSRs, Social Security Acquiescence...

2013-02-20

81

REVOLUCIÓN CIENTÍFICA, TECNOLÓGICA Y ENERGÉTICA: LA INFLUENCIA SOBRE EL PENSAMIENTO ECONÓMICO DE LOS SIGLOS XVI Y XVII 1  

Microsoft Academic Search

This work places some of the economic writings of the XVI and XVII centuries in the context of the technological and scientific revolutions of the period and those preceding it, the transition phase from feudalism into capitalism. It also discusses the change in focus by the aut- hors, from theological, logical and ethic subjects to the \\

SINCLAIR MALLET; GUY GUERRA; CONTI MACEDO; TANIA MARÍA DE CASTRO; CARVALHO NETO

2006-01-01

82

Calorimetric particle detectors with superconducting transition edge thermometers  

NASA Astrophysics Data System (ADS)

The cryogenic detector group at the MPI, Munchen, in collaboration with the Technische Universitat Munchen, is developing calorimetric detectors utilizing large absorber crystals coupled to superconducting transition edge thermometers. At low temperature, high energy resolution results from the low detector heat capacity and the strong temperature dependence of the resistance of the thermometer at the normal/superconducting phase transition. The transition edge thermometer is a thin film at very low Tc superconductor deposited directly on the absorber. Results from two detectors yielding excellent energy resolution are presented. One of these detectors was fabricated with an Ir strip thermometer, and the other with an Ir/Au proximity effect bilayer. Detailed studies have resulted in a model which will be used to optimize future detectors.

Dummer, D.

1993-03-01

83

ac-Calorimetric Measurements of Transverse Thermal Conductivity  

NASA Astrophysics Data System (ADS)

We are developing an ac-calorimetric technique, heating one surface of a thin sample with oscillating power and measuring the temperature oscillations on the opposite surface, to measure the thermal conductivity of solids. While the temperature oscillations are inversely proportional to the heat capacity at low frequencies, at higher frequencies the response is limited by the transverse thermal diffusivity. Because of the response times of thermometers and the fact that the magnitude of the temperature oscillation varies inversely with frequency, this technique is most useful for materials with low thermal conductivities, such as the interlayer conductivity in layered materials. We will show results on ``standard'' materials (teflon, sapphire) as well as the layered organic semiconductors, rubrene and TIPS-pentacene.

Zhang, Hao; Brill, Joseph

2013-03-01

84

20 CFR 416.573 - How much will we withhold from your title II and title VIII benefits to recover a title XVI...  

Code of Federal Regulations, 2013 CFR

...your title II and title VIII benefits to recover a title XVI overpayment...Section 416.573 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL...AND DISABLED Payment of Benefits, Overpayments, and...

2013-04-01

85

Experimental M1 transition rates in K XI, K XV, and K XVI  

NASA Astrophysics Data System (ADS)

Transition probabilities of three magnetic dipole (M1) transitions in multiply charged ions of potassium have been measured using the Livermore electron beam ion trap EBIT-2. Our results for the atomic level lifetimes are 4.44+/-0.10 ms for K XI (F-like) 2s22p5 2Po1/2, 4.47+/-0.10 ms for K XV (B-like) 2s22p 2Po3/2, and 7.6+/-0.5 ms for K XVI (Be-like) 2s2p 3Po2. The results confirm the accuracy of most predictions to within 3% of ground-state and 7% of excited-state transitions.

Träbert, E.; Beiersdorfer, P.; Brown, G. V.; Chen, H.; Pinnington, E. H.; Thorn, D. B.

2001-09-01

86

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

87

A calorimetric unit for measurements of the thermal effects of reactions in solution  

NASA Astrophysics Data System (ADS)

A calorimetric unit for measurements of the thermal effects of reactions in solution was created. The unit was designed following the classic scheme of a hermetic liquid calorimeter working under isoperibolic conditions, it had a thermometric sensitivity of 10-4 K and a calorimetric sensitivity of 10-2 J. The accuracy of calorimeter operation was checked against the heats of solution of potassium chloride. The molar integral enthalpies of solution of glycine in water at 298 K were determined.

Grigorova, E. V.; Bondareva, L. P.; Kadantsev, A. V.; Byval'Tsev, Yu. A.; Khripushin, V. V.; Kornienko, T. S.

2010-09-01

88

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

89

Genetic comparison of the head of Henri IV and the presumptive blood from Louis XVI (both Kings of France).  

PubMed

A mummified head was identified in 2010 as belonging to Henri IV, King of France. A putative blood sample from the King Louis XVI preserved into a pyrographically decorated gourd was analyzed in 2011. Both kings are in a direct male-line descent, separated by seven generations. We have retrieved the hypervariable region 1 of the mitochondrial DNA as well as a partial Y-chromosome profile from Henri IV. Five STR loci match the alleles found in Louis XVI, while another locus shows an allele that is just one mutation step apart. Taking into consideration that the partial Y-chromosome profile is extremely rare in modern human databases, we concluded that both males could be paternally related. The likelihood ratio of the two samples belonging to males separated by seven generations (as opposed to unrelated males) was estimated as 246.3, with a 95% confidence interval between 44.2 and 9729. Historically speaking, this forensic DNA data would confirm the identity of the previous Louis XVI sample, and give another positive argument for the authenticity of the head of Henri IV. PMID:23283403

Charlier, Philippe; Olalde, Iñigo; Solé, Neus; Ramírez, Oscar; Babelon, Jean-Pierre; Galland, Bruno; Calafell, Francesc; Lalueza-Fox, Carles

2012-12-30

90

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

91

Adiabatic Heat of Hydration Calorimetric Measurements for Reference Saltstone Waste  

SciTech Connect

The production of nuclear materials for weapons, medical, and space applications from the mid-1950's through the late-1980's at the Savannah River Site (SRS) generated approximately 35 million gallons of liquid high-level radioactive waste, which is currently being processed into vitrified glass for long-term storage. Upstream of the vitrification process, the waste is separated into three components: high activity insoluble sludge, high activity insoluble salt, and very low activity soluble salts. The soluble salt represents 90% of the 35 million gallons of overall waste and is processed at the SRS Saltstone Facility, where it mixed with cement, blast furnace slag, and flyash, creating a grout-like mixture. The resulting grout is pumped into aboveground storage vaults, where it hydrates into concrete monoliths, called saltstone, thus immobilizing the low-level radioactive salt waste. As the saltstone hydrates, it generates heat that slowly diffuses out of the poured material. To ensure acceptable grout properties for disposal and immobilization of the salt waste, the grout temperature must not exceed 95 C during hydration. Adiabatic calorimetric measurements of the heat generated for a representative sample of saltstone were made to determine the time-dependent heat source term. These measurements subsequently were utilized as input to a numerical conjugate heat transfer model to determine the expected peak temperatures for the saltstone vaults.

Bollinger, James

2006-01-12

92

Calorimetric studies on the phenolic glycoside D(-)-salicin.  

PubMed

A pure orthorhombic phase sample of D(-)-salicin was purified and characterized for calorimetric measurements. From differential scanning calorimetry (DSC) measurements it was found that the onset and maximum temperatures of the fusion peak were T(on) = (473.30 +/- 0.05) K and T(max) = (474.74 +/- 0.05) K, respectively, and that the corresponding standard enthalpy of fusion was Delta(cr)(l) H(m)(o) = (55.5 +/- 0.4) kJ mol(-1). From the last two values the standard entropy of fusion is calculated as Delta(cr)(l) S(m)(o) = (116.9 +/- 0.4) J mol(-1) K(-1). The standard molar enthalpy of formation of orthorhombic D(-)-salicin at T = 298.15 K, was determined as Delta(f) H(m)(o) (C(13)H(18)O(7), cr, orthorhombic) = -(1366.9 +/- 3.2) kJ mol(-1), by combustion calorimetry. From the results of solution calorimetry obtained in this work and some auxiliary values taken from the literature the enthalpy of reaction of hydrolysis of D(-)-salicin to produce beta-glucose and o-hydroxybenzyl alcohol was found marginally thermoneutral, if the uncertainty interval was considered. Additionally, specific heat capacity measurements on the orthorhombic phase, glass and liquid-quenched glass obtained by DSC was reported. PMID:18484613

Pinto, Susana S; Diogo, Hermínio P

2008-12-01

93

XVI European Charcot Foundation Lecture: Nutrition and environment, can MS be prevented?  

PubMed Central

Multiple sclerosis is a relatively common debilitating neurologic disease that affects people in early adulthood. While the characteristic pathology of MS has been well described, the etiology of the disease is not well understood, despite decades of research and the identification of strong genetic and environmental candidates for susceptibility. A question central to all diseases, but posed specifically for MS at the XVI European Charcot Foundation Lecture, was ‘Can MS be prevented?’ To address this question, we have evaluated the available data regarding nutritional and environmental factors that may be related to MS susceptibility and suggest the extent to which a potential intervention may reduce disease burden. It is our opinion that intervention, particularly supplementation with vitamin D, could have a dramatic impact on disease prevalence. Understanding that any intervention or behavioral modification will surely act in the context of genetic susceptibility and unidentified stochastic events, it is likely that not all MS is ‘preventable’. Epidemiologic observation has provided key insights into environmental and nutritional factors that may alter one’s susceptibility to MS, however, there are still many questions in unraveling the etiology of this complex disease.

Simon, Kelly Claire; Munger, Kassandra L; Ascherio, Alberto

2012-01-01

94

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.

95

Energy associated with dislocations: A calorimetric study using synthetic quartz  

NASA Astrophysics Data System (ADS)

High temperature oxide melt solution calorimetry was used to study the energy associated with dislocations in quartz by comparing undeformed and deformed single crystals of synthetic quartz. Samples were deformed at 698 K, 1000 1500 MPa at a strain rate of 10-5 sec-1. Two sets of calorimetric measurements were made: (i) using a Pt capsule as a container for powdered sample, and (ii) using pellets made from sample powder without any container. For the first set of measurements, the undeformed sample with a dislocation density of enthalpy is sum of heat content H 973- H 295 and enthalpy of solution in molten lead borate at 973 K of 39.22 ± 1.00 kJ mol-1, while the sample deformed in the dislocation creep regime with a dislocation density of 6 × 1010 to 1 × 1011 cm-2 gave an enthalpy of 38.59 ± 0.78 kJ mol-1. For the second set of measurements the measured enthalpy of the undeformed sample was 38.87 ± 0.31 kJ mol-1, and that of a deformed sample with a dislocation density of 3 × 1010 to 1 × 1011 cm-2 was 38.24 ± 0.58 kJ mol-1. The present study and previous theoretical calculations and estimates are consistent and suggest that the energy associated with dislocations in quartz is ˜ 0.6 ± 0.6 kJ mol-1 for a dislocation density of ˜ 1011 cm-2; a precise value is difficult to determine because of the overlapping errors. These results indicate that for geologically realistic dislocation densities, the maximum excess energy due to dislocations would be ˜ 0.5 kJ mol-1 for most minerals; the exact value would depend on the Burgers vector as well as the shear modulus.

Liu, M.; Yund, R. A.; Tullis, J.; Topor, L.; Navrotsky, A.

1995-03-01

96

Neutron detection by measuring capture gammas in a calorimetric approach  

NASA Astrophysics Data System (ADS)

The neutron capture detector (NCD) is introduced as a novel detection scheme for thermal and epithermal neutrons that could provide large-area neutron counters by using common detector materials and proven technologies. The NCD is based on the fact that neutron captures are usually followed by prompt gamma cascades, where the sum energy of the gammas equals to the total excitation energy of typically 6–9 MeV. This large sum energy is measured in a calorimetric approach and taken as the signature of a neutron capture event. An NCD consists of a neutron converter, comprising of constituents with large elemental neutron capture cross-section like cadmium or gadolinium, which is embedded in common scintillator material. The scintillator must be large and dense enough to absorb with reasonable probability a portion of the sum energy that exceeds the energy of gammas emitted by common (natural, medical, industrial) radiation sources. An energy window, advantageously complemented with a multiplicity filter, then discriminates neutron capture signals against background. The paper presents experimental results obtained at the cold-neutron beam of the BER II research reactor, Helmholtz-Zentrum Berlin, and at other neutron sources with a prototype NCD, consisting of four BGO crystals with embedded cadmium sheets, and with a benchmark configuration consisting of two separate NaI(Tl) detectors. The detector responses are in excellent agreement with predictions of a simulation model developed for optimizing NCD configurations. NCDs could be deployed as neutron detectors in radiation portal monitors (RPMs). Advanced modular scintillation detector systems could even combine neutron and gamma sensitivity with excellent background suppression at minimum overall expense.

Pausch, Guntram; Herbach, Claus-Michael; Kong, Yong; Lentering, Ralf; Plettner, Cristina; Roemer, Katja; Scherwinski, Falko; Stein, Juergen; Schotanus, Paul; Wilpert, Thomas

2011-10-01

97

Calorimetric investigations of the enzyme catalyzed sucrose hydrolysis 1 Dedicated to Prof. Günter Marx from the TU-Chemnitz on the occasion of his 60th birthday. 1  

Microsoft Academic Search

The study presents the results of calorimetric investigations of the invertase catalyzed sucrose hydrolysis. The aim of the investigation is the kinetic interpretation of calorimetric curves with respect to the inhibitor effect of selected heavy metal ions and the calorimetric determination of the invertase activity.

Regina Hüttl; Katrin Oehlschläger; Gert Wolf

1999-01-01

98

Religion and the Catholic church's view on (heart) transplantation: a recent statement of Pope Benedict XVI and its practical impact.  

PubMed

Heart transplantation is performed on approximately 4,000 patients per year worldwide and is considered the last resort for treatment of end-stage heart diseases. Due to persistent organ shortage, resources are limited, waiting periods are extensive, and patients still die while being on a waiting list for transplantation. The role of all churches and the support of the representatives of the churches are critical for the spiritual wellbeing of patients awaiting heart transplantation as well as for prospective individual organ donors and their families. The supportive role of the Roman Catholic Church and the recent statement of Pope Benedict XVI on organ donation are discussed. PMID:19784776

Schwarz, Ernst R; Rosanio, Salvatore

2011-09-01

99

Calorimetric apparatus for alternating current loss measurements on high-temperature superconductors  

Microsoft Academic Search

The use of high-temperature superconductors in electric power components requires the knowledge of their alternating current (ac) losses. Methods are therefore needed to characterize the conductors with respect to their ac losses under applicationlike conditions. In this article we describe a calorimetric setup for ac loss measurements on long length high-temperature superconductors carrying ac transport currents in ac external magnetic

N. Magnusson; S. Hörnfeldt

1998-01-01

100

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

101

Rheological and calorimetric properties of recycled bisphenol A poly(carbonate)  

Microsoft Academic Search

Mechanical recycling of engineering polycarbonate wastes provides an interesting way to decrease the impact on environment, if the degradation due to successive processing is properly characterized. We analyzed polycarbonate (PC) degradation generated by eight successive recycling, using rheological, calorimetric and colorimetric tools at each step. From the first to the fifth recycling, an increase of storage modulus E? (at T=30 °C

J. F. Feller; A. Bourmaud

2003-01-01

102

Differential scanning calorimetric analysis for monitoring the oxidation of heated oils  

Microsoft Academic Search

A simple and reliable differential scanning calorimetric (DSC) method was developed for monitoring the oxidation in heated oils. Three different types of edible oils, namely, corn oil (CO), refined, bleached and deodorised palm olein (RBDPO) and soybean oil (SO) were used in this study. The DSC method was based on the cooling thermogram of oil samples at a scanning rate

C. P Tan; Y. B Che Man

1999-01-01

103

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

104

A Simple Calorimetric Experiment That Highlights Aspects of Global Heat Retention and Global Warming  

Microsoft Academic Search

This report outlines a simple calorimetric experiment for the general chemistry laboratory that illustrates a classic prin- ciple of chemical thermodynamics and, in a somewhat novel way, gives students an introduction to some broad features associated with global heat retention and global warming. The earth has had a robust greenhouse warming effect for mil- lions of years; otherwise the planet

Joel D. Burley; Harold S. Johnston

2007-01-01

105

A high pressure calorimetric experiment to validate the liquid-liquid critical point hypothesis in water  

Microsoft Academic Search

An experimental proposal to test the existence of a liquid-liquid critical point in water, based on high pressure calorimetric measurements, is presented on this paper. Considering the existence of an intramolecular correlation in the water molecule we show how the response of the specific heat at high pressure is different depending on the existence, or not, of the second critical

Manuel I. Marques

2007-01-01

106

Thermal explosion analysis of methyl ethyl ketone peroxide by non-isothermal and isothermal calorimetric applications  

Microsoft Academic Search

In the past, process incidents attributed to organic peroxides (OPs) that involved near misses, over-pressures, runaway reactions, and thermal explosions occurred because of poor training, human error, incorrect kinetic assumptions, insufficient change management, and inadequate chemical knowledge in the manufacturing process. Calorimetric applications were employed broadly to test organic peroxides on a small-scale because of their thermal hazards, such as

Jen-Hao Chi; Sheng-Hung Wu; Chi-Min Shu

2009-01-01

107

Calorimetric control for high cell density cultivation of a recombinant Escherichia coli strain  

Microsoft Academic Search

In order to achieve maximum productivity of recombinant proteins in Escherichia coli high cell density cultivation (HCDC) strategies have been the subject of many studies. The aim of this work was the application of calorimetric methods to HCDC. The specific growth rate of a recombinant E. coli strain producing green fluorescent protein (GFP) was controlled during fed-batch cultivations by estimating

Richard Biener; Anne Steinkämper; Johannes Hofmann

2010-01-01

108

[Menarche, menstrual and sociodemographic characteristics of Puerto Rican female athletes in the XV and XVI Central American and Caribbean Games].  

PubMed

This investigation described maturation, menstrual and socio-demographic characteristics of 65 Puerto Rican women athletes that were interviewed during the XVI Central American and Caribbean Games (CACG), Mexico City in 1990. The results were compared with those of Puerto Rican women athletes (n = 52) at the XV CACG, Santiago Dominican Republic, 1986. The quantitative variables (age, age at initiation of training, years of training, age at menarche, birth order, and family size) were not statistically different (t-independent, p > or = 0.05). The observed frequencies for the qualitative variables (menstrual characteristics, degree of certainty in the recall of age of menarche, use of oral contraceptives, and marital status) were very similar. In conclusion: the women at the XVI CAC in Mexico demonstrated similar maturational, menstrual and socio-demographic characteristics to the those athletes evaluated four years earlier in Santiago and based on their long history of training, both samples were representative of athletically mature athletes. The findings were very similar to those reported for olympic athletes and such data expands the available information on Puerto Rican women athletes. PMID:8272482

Rivera, M A; Mendez Zamora, I; Matos, R M; Rivera, A

1993-09-01

109

A calorimetric system based on the LKB 10700-1 flow microcalorimeter  

NASA Astrophysics Data System (ADS)

An electrically calibrated and computer-controlled apparatus based on the LKB 10700-1 flow microcalorimeter was set up and tested by determining the enthalpies of dilution of aqueous solutions of sucrose and HCl at 298.15 K. The obtained results are in good agreement with the corresponding reference values recommended in the literature. The quality of the calorimetric signal in terms of noise, linearity and baseline drift, and the instrument time constant were analyzed. Also investigated were the influences of the flow rate and of the viscosity of the calorimetric liquid on the position of the baseline. The new calibration system enables powers ~25 times smaller than those possible with the original one to be released inside the calorimetric cells. Electrical calibrations carried out with water as the sole calorimetric liquid indicated that the precision of the calibration constant, ?, quickly improved from ~9% to ~0.4% with the increase of the input power, P, from ~2 µW to ~50 µW, and stabilized at ~0.1% for P >= 100 µW. The calibration constant was also found to linearly increase with the flow rate of the calorimetric liquid and to vary by less than 1% over a period of eight months under similar experimental conditions. Finally a new experimental procedure for heat of dilution measurements, which combines calibration and experiment in a single run, was evaluated. This method allows a significant economy in experiment time with apparently no accuracy loss relative to the conventional procedure recommended in the literature.

Leskiv, Miroslav; Bernardes, Carlos E. S.; Minas da Piedade, Manuel E.

2009-07-01

110

LA PROBLEMÁTICA DE LA CLASIFICACIÓN DE LA CONSONANCIA EN EL SIGLO XVI Y LA TEORÍA DE LA CONSONANCIA DE FRANCISCO SALINAS  

Microsoft Academic Search

A mediados del siglo XVI nos encontramos con una clasificación de los intervalos consonantes más o menos admitida por todos los teóricos del momento: son consonancias perfectas la octava, la quinta y la cuarta, mientras que son consonancias imperfectas las terceras y las sextas. Zarlino incluso desarrolla un marco metafísico (el numero senario) de explicación de la consonancia que intenta

Amaya Sara García Pérez

2003-01-01

111

Compound formation and glassy solidification in the system gelatin-water  

Microsoft Academic Search

Calorimetric investigations of the system gelatin-water lead to the conclusion that the state diagram is of the eutectic type. At the invariant eutectic temperature ice, nearly pure water and an intermediate compound with an over-all concentration of 67 % by wt gelatin coexist. The liquidus and the solidus curves have been determined up to temperatures very close to the melting

P. Reutner; B. Luft; W. Borchard

1985-01-01

112

Calorimetric study of the superconducting and normal state properties of Ca(Fe1-xCox)2As2  

NASA Astrophysics Data System (ADS)

We present a calorimetric study on single crystals of Ca(Fe1-xCox)2As2 (x = 0, 0.032, 0.051, 0.056, 0.063, and 0.146). The combined first order spin-density wave/structural transition occurs in the parent CaFe2As2 compound at 168 K and gradually shifts to lower temperature for low doping levels (x = 0.032 and x = 0.051). It is completely suppressed upon higher doping x >= 0.056. Simultaneously, superconductivity appears at lower temperature with a transition temperature around Tc ~ 14.1 K for Ca(Fe0.937Co0.063)2As2. The phase diagram of Ca(Fe0.937Co0.063)2As2 has been derived and the upper critical field is found to be ?0H(c)2 = 11.5 T and ?0H(ab)c2 = 19.4 T for the c and ab directions, respectively.

Abdel-Hafiez, M.; Harnagea, L.; Singh, S.; Stockert, U.; Wurmehl, S.; Leps, N.; Klingeler, R.; Wolter, A. U. B.; Büchner, B.

2012-12-01

113

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

114

Thermodynamic properties by non-calorimetric methods: Progress report  

NASA Astrophysics Data System (ADS)

This project for the Office of Energy Research focuses on the noncalorimetric determination of thermodynamic properties of polynuclear aromatic molecules through the extension of existing correlation methodologies and through molecular spectroscopy with statistical mechanics. This report highlights progress during the first third of the contract period. Important advances include: derivation of group-contribution parameters for estimation of thermodynamic properties for polycyclic hydrocarbon and nitrogen-containing compounds; calculation of thermodynamic properties for eight key monocyclic compounds based on new and literature spectra were completed for the derivation of 'ring- correction' property estimation parameters; design and construction of a long pathlength, far-infrared sample cell for the collection of vapor-phase spectra of low vapor-pressure compounds; development of a method to predict the vibrational frequencies of two- and three-ring polycyclic molecules to an accuracy sufficient for identifying the fundamental vibrations in experimental spectra; and development of a method to calculate the kinetic energy expansions as a function of the coordinate for the ring-puckering, ring-twisting (in-phase), and ring-twisting (out-of-phase) vibrations of 9,10-dihydroanthracene and related molecules.

Strube, M. Michael; Chirico, R. D.; Collier, W. B.; Steele, W. V.

115

Comparison of thermodesorption and calorimetric methods of investigation of acidity of zeolites  

SciTech Connect

The thermodesorption of NH/sub 3/ from Na- and H-forms of different types of zeolites (A, Y, mordenite) in the temperature range of 30-440/sup 0/C was studied by the gravimetric method. A correlation was discovered between the temperature-dependent desorption and the calorimetrically measured heat of adsorption. It was shown that thermodesorption data can be used for rapid approximate determination of heats of adsorption of NH/sub 3/ on zeolites.

Kapustin, G.I.; Brueva, T.R.; Kutateladze, G.M.; Klyachko, A.P.

1987-12-01

116

Positron annihilation and differential scanning calorimetric study of poly(trimethylene terephthalate)\\/EPDM blends  

Microsoft Academic Search

The blends of poly(trimethylene terephthalate) (PTT) and ethylene propylene diene monomer (EPDM) with different composition have been studied by positron lifetime technique (PLT) and differential scanning calorimetric (DSC) measurements. The DSC results for the blends of 50\\/50 and 40\\/60 show clear two glass transition temperatures indicating two-phase system. No melting point depression was observed for the blend system, which strongly

H. B. Ravikumar; C. Ranganathaiah; G. N. Kumaraswamy; S. Thomas

2005-01-01

117

Calorimetric thermal-vacuum performance characterization of the BAe 80 K space cryocooler  

Microsoft Academic Search

A comprehensive characterization program is underway at JPL to generate test data on long-life, miniature Stirling-cycle cryocoolers for space application. The key focus of this paper is on the thermal performance of the British Aerospace (BAe) 80 K split-Stirling-cycle cryocooler as measured in a unique calorimetric thermal-vacuum test chamber that accurately simulates the heat-transfer interfaces of space. Two separate cooling

V. Y. Kotsubo; D. L. Johnson; R. G. Ross Jr.

1992-01-01

118

Temperature-modulated differential scanning calorimetric measurements on nascent ultra-high molecular mass polyethylene  

Microsoft Academic Search

Temperature-modulated differential scanning calorimetric (TMDSC) measurements on nascent ultra-high molecular mass polyethylene (UHMMPE) in scanning as well as quasi-isothermal mode are presented. From these measurements, a special irreversible relaxation process in the pre-melting region can be separated, which only occur on the first heating of the nascent material. The frequency dependence of this process yield a characteristic time constant of

G. W. H. Höhne; L. Kurelec

2001-01-01

119

Calorimetric determination of enthalpies of lysozyme folding at a liquid-solid interface  

Microsoft Academic Search

Summary  Calorimetric determination of the total enthalpy changes (?Hi) of guanidine-denatured lysozyme (Lys) during the adsorption with simultaneously refolding on the surface of hydrophobic\\u000a interaction chromatography packings was carried out at 250.001C. The measured ?Hiin the circumstances should include the changes in the three fractions: adsorption, dehydration and molecular conformation.\\u000a It was found that when the unfolded Lys molecules are adsorbed

X. P. Geng; H. F. Zhang; B. H. Wang; X. D. Geng; J. W. Xing

2005-01-01

120

Test results of an apparatus for calorimetric measurement of AC losses in superconductors  

Microsoft Academic Search

A description is given of a novel method to measure calorimetrically AC losses in superconducting samples. The boil-off gas is stored below the liquid helium level in a measuring tube. Losses in the range of 1 mW up to 100 mW can be measured with an accuracy of 3%. Results of measurements of AC losses in superconducting wires are presented.

J. A. Eikelboom

1992-01-01

121

Use of calorimetric assay for operational and accountability measurements of pure plutonium metal  

SciTech Connect

Plutonium pure metal products (PMP) are high purity plutonium metal items produced by electrorefining. The plutonium metal is produced as an approximately 3-kg ring. Accountability measurements for the electro-refining runs are typically balance/weight factor (incoming impure metal), chemistry (pure metal rings), and calorimetric assay or neutron counting of the crucibles and other wastes. The PMP items are qualified for their end use by extensive chemical assay. After PMP materials are made they are often sent to the vault for storage before being sent to the casting process, the next step in the production chain. The chemical assay of PMP items often takes a few weeks; however, before the metal items are allowed into the vault they must be measured. Non-destructive assay personnel measure the metals either by multiplicity neutron counting or calorimetric assay, depending on which instrument is available, thus generating comparisons between non-destructive assay and chemical assay. The suite of measurements, calorimetric assay, chemical assay, and neutron mUltiplicity counting is compared for a large group of PMP items.

Cremers, Teresa L [Los Alamos National Laboratory; Sampson, Thomas E [Los Alamos National Laboratory

2010-01-01

122

On-device extraction of thermal thin-film properties in calorimetric flow sensors  

NASA Astrophysics Data System (ADS)

In diaphragm-based micromachined calorimetric flow sensors, the convective heat transfer through the test fluid competes with the spurious heat shunt induced by the thin-film diaphragm where the heater and the temperature sensors are embedded. Therefore, accurate knowledge of the thermal transport properties (thermal conductivity and diffusivity) and the emissivity of the diaphragm is mandatory for design, simulation, and optimization of such devices. However, these parameters can differ considerably from those stated for bulk material and they are typically dependent on the production process. Commonly used methods for their determination require the fabrication of custom specimens. In order to overcome this serious drawback, we developed a novel technique to extract the thermal thin-film properties directly from measurements carried out on calorimetric flow sensors. Here, the heat transfer frequency response from the heater to the thermistors is measured and compared to a theoretically obtained relationship arising from an extensive two-dimensional analytical model. This model covers the heat generation by the heater, the heat conduction in the diaphragm, the radiation loss at the diaphragm's surface, and the heat sink caused by the supporting silicon frame. In this contribution, we report in detail on the measurement setup, the theoretical model for the associated parameter extraction, and the results obtained from measurements on calorimetric flow sensors featuring dielectric thin-film diaphragms made of PECVD Si3N4.

Beigelbeck, Roman; Talic, Almir; Cerimovic, Samir; Kohl, Franz; Keplinger, Franz

2011-05-01

123

Calorimetric and Spectroscopic Studies of the Thermotropic Phase Behavior of the n-Saturated 1,2-Diacylphosphatidylglycerols  

PubMed Central

The polymorphic phase behavior of a homologous series of n-saturated 1,2-diacyl phosphatidylglycerols (PGs) was studied by differential scanning calorimetry and Fourier transform infrared and 31P-nuclear magnetic resonance spectroscopy. When dispersed in aqueous media under physiologically relevant conditions, these compounds exhibit two thermotropic phase transitions that are structurally equivalent to the well-characterized pretransitons and gel/liquid-crystalline phase transitions exhibited by bilayers of the corresponding 1,2-diacyl phosphatidylcholines. Furthermore, when incubated at low temperatures, their gel phases spontaneously transform into one or more solid-like phases that appear to be highly ordered, quasicrystalline bilayers that are probably partially dehydrated. The quasicrystalline structures, which form upon short-term, low-temperature annealing of these lipids, are meta-stable with respect to more stable structures, to which they eventually transform upon prolonged low-temperature incubation. The rates of formation of the quasicrystalline phases of the PGs generally tend to decrease as hydrocarbon chain length increases, and PGs whose hydrocarbon chains contain an odd number of carbon atoms tend to be slower than those of neighboring even-numbered homologs. The calorimetric data also indicate that the quasicrystalline phases of these compounds become progressively less stable relative to both their gel and liquid-crystalline phases as the length of the hydrocarbon chain increases and that they decompose either to the liquid-crystalline phase (short- and medium-chain compounds) or to the normal gel phase (long-chain compounds) upon heating. The spectroscopic data indicate that although there is odd-even alternation in the structures of the quasicrystalline phases formed upon short-term low-temperature incubation of these compounds, the structural features of the stable quasicrystalline phases eventually formed are all similar. Furthermore, the degree of hydration and the nature of hydrogen bonding interactions in the headgroup and interfacial regions of these PG bilayers differ significantly from that observed in all other phospholipid bilayers studied so far. We suggest that many of the properties of PG bilayers can be rationalized by postulating that the glycerol moiety of the polar headgroup is directly involved in shielding the negative charges at the surface of the bilayer by means of hydration-like hydrogen bonding interactions with the phosphate moiety.

Zhang, Yuan-Peng; Lewis, Ruthven N. A. H.; McElhaney, Ronald N.

1997-01-01

124

Calorimetric Study of Several Cuprates with Restricted Dimensionality  

Microsoft Academic Search

By means of specific heat and magnetic susceptibility measurements we investigated the magnetic compounds of various crystal structure, CuWO4, LiCuVO4, CuSb2O6, CuNb2O6 and CuBi2O4. All of these cuprates revealed strong one-dimensional (1D) correlations persisting up to very high temperatures which are well explained by the S=1\\/2 Heisenberg antiferromagnetic linear-chain model. At lower temperatures they showed various long-range magnetic ordering except

Masaaki Yamaguchi; Tomoki Furuta; Masayasu Ishikawa

1996-01-01

125

Vapor pressures and thermal data for three high-boiling compounds of petroleum interest: 1-phenyldodecane, (5?)-cholestane, adamantane  

Microsoft Academic Search

Vapor pressures above liquid and solid phases and enthalpies of vaporization and sublimation were established in a wide temperature range for three hydrocarbons that are among the model compounds for higher boiling petroleum fractions and coal liquids. The recommended values were obtained by combining the data from vapor pressure measurements with the calorimetric measurements of heat capacities and heats of

Ilham Mokbel; Kv?toslav R?ži?ka; Vladim??r Majer; Vlastimil R?ži?ka; Madeleine Ribeiro; Jacques Jose; Milan Zábranský

2000-01-01

126

Measurement and Modeling of Inner-Shell Satellites of Na-like Fe XVI between 14.5 ?A and 18 ?A  

SciTech Connect

We have used the University of California Lawrence Livermore National Laboratory's EBIT-I electron beam ion trap to perform measurements of the wavelengths and relative intensities of the X-ray lines from inner-shell satellite transitions in sodium-like Fe XVI. The measurements were carried out with high-resolution crystal and grating spectrometers and covered the 14.5-18 {angstrom} wavelength band. Contrary to predicted line strengths and positions found in the literature, our results show that the strongest inner-shell satellites of Fe XVI are located near 15.2 {angstrom}. This is near the location of the 3d {yields} 2p intercombination line in Fe XVII. Calculations using the Flexible Atomic Code are presented, which agree well with the EBIT-I measurements.

Graf, A; Beiersdorfer, P; Brown, G V; Gu, M F

2007-09-10

127

Thermochemistry of 2- and 3-acetylthiophenes: calorimetric and computational study.  

PubMed

The relative stabilities of 2- and 3-acetylthiophenes have been evaluated by experimental thermochemistry and the results compared to high-level ab initio calculations. The enthalpies of combustion, vaporization, and sublimation were measured by rotating-bomb combustion calorimetry, Calvet microcalorimetry, correlation gas chromatography, and Knudsen effusion techniques and the gas-phase enthalpies of formation, at T = 298.15 K, were determined. Standard ab initio molecular orbital calculations at the G2 and G3 levels were performed, and a theoretical study on the molecular and electronic structures of the compounds studied has been conducted. Calculated enthalpies of formation using atomization and isodesmic reactions are compared with the experimental data. Experimental and theoretical results show that 2-acetylthiophene is thermodynamically more stable than the 3-isomer. A comparison of the substituent effect of the acetyl group in benzene and thiophene rings has been carried out. PMID:17918809

Roux, María Victoria; Temprado, Manuel; Jiménez, Pilar; Notario, Rafael; Chickos, James S; Santos, Ana Filipa L O M; da Silva, Manuel A V Ribeiro

2007-10-05

128

Wavelengths, classifications, and ionization energies in the isoelectronic sequences from Yb II and Yb III through Bi XV and Bi XVI  

Microsoft Academic Search

Spectral observations are reported for transitions to the ground term and first excited term of the one-electron configurations in the 4f¹⁴5p⁶nl isoelectronic sequence from Yb II through Bi XV. Resonance lines are reported for the isoelectronic sequence Yb III through Bi XVI in which the ground state is 4f¹⁴5p⁶ ¹Sâ and the upper levels are the J = 1 levels

Victor Kaufman; Jack Sugar

1976-01-01

129

High-accuracy MR-MP Perturbation Theory Energy and Radiative Rates Calculations for Core-excited Transitions in Fe XVI  

NASA Astrophysics Data System (ADS)

Accurate theoretical energy level, lifetime, and transition probability calculations of core-excited Fe XVI were performed employing the relativistic Multireference Møller-Plesset perturbation theory. In these computations the term energies of the highly excited n <= 5 states arising from the configuration 1s 22sk 2pm 3l p nl' q , where k + m + p + q = 9, l <= 3 and p + q <= 2 are considered, including those of the autoionizing levels with a hole-state in the L-shell. All even and odd parity states of sodium-like iron ion were included for a total of 1784 levels. Comparison of the calculated L-shell transition wavelengths with those from laboratory measurements shows excellent agreement. Therefore, our calculation may be used to predict the wavelengths of as of yet unobserved Fe XVI, such as the second strongest 2p-3d Fe XVI line, which has not been directly observed in the laboratory and which blends with one of the prominent Fe XVII lines.

Díaz, F.; Vilkas, M. J.; Ishikawa, Y.; Beiersdorfer, P.

2013-07-01

130

Calorimetric Study of Several Cuprates with Restricted Dimensionality  

NASA Astrophysics Data System (ADS)

By means of specific heat and magnetic susceptibility measurements we investigated the magnetic compounds of various crystal structure, CuWO4, LiCuVO4, CuSb2O6, CuNb2O6 and CuBi2O4. All of these cuprates revealed strong one-dimensional (1D) correlations persisting up to very high temperatures which are well explained by the S=1/2 Heisenberg antiferromagnetic linear-chain model. At lower temperatures they showed various long-range magnetic ordering except for CuNb2O6. In particular, we observed a rather unusual transition at 2.4 K for LiCuVO4 which is conjectured to be a transition to the S=1/2 quadratic Ising antiferromagnet, thereby demonstrating a dimensional cross-over of correlations from 1D to 2D. The magnetic susceptibility and specific heat exhibit a critical point and a logarithmic divergence at 2.4 K, respectively, as predicted by theory. We herein report the experimental results and the preliminary analyses of these low-dimensional cuprates.

Yamaguchi, Masaaki; Furuta, Tomoki; Ishikawa, Masayasu

1996-09-01

131

Calorimetric measurements of energy transfer efficiency and melting efficiency in CO2 laser beam welding  

NASA Astrophysics Data System (ADS)

The previous calorimetric studies of weld melting efficiency and arc efficiency in the GTAW and PAW processes have naturally led us to speculate as to the magnitude of the efficiencies in the LBW process which to data have also not been adequately investigated. Most welding engineers that have had experience with the LBW process are acutely aware that the metals' absorptivity, the surface finish, and the laser wavelength, all play an important role in affecting the energy transfer efficiency, but the extent of their influence and our understanding of the influence of other process variables is not well understood. In addition, it is widely thought that only the LBW or EBW processes can be selected for applications where thermal damage and distortion from the welding process must be kept to a minimum. For these reasons, we have looked forward to performing these calorimetric experiments since they potentially can answer such important questions as: whether or not the melting efficiency of the LBW process is superior to that obtainable with conventional GTAW and PAW welding processes. This study was prompted by poor production yields on switching device due to cracking of the ceramic header after final closure welding with the CO2 LBW process. This calorimetric study was begun in hopes of determining if allowed variations in production process control variables were responsible for increases in heat input and the resulting thermal stresses. By measuring the net heat input to the workpiece with the calorimeter and by measuring the laser output energy and the weld fusion zone size it was possible to determine the magnitudes of both the energy transfer efficiency and the melting efficiency as well as observe their dependence on the process variables.

Fuerschbach, P. W.

132

Calorimetric studies of removal of nonsteroidal anti-inflammatory drugs diclofenac and dipyrone from water  

Microsoft Academic Search

Chitosan microspheres were applied to remove the pollutants diclofenac and dipyrone from water. Adsorption studies were adjusted\\u000a to Langmuir equation. The maximum number of adsorbed moles gave 5.25 × 10?4 and 4.83 × 10?4 mol of diclofenac and dipyrone, respectively, per gram of chitosan microspheres. The interactions in solid\\/liquid interface\\u000a were calorimetrically followed and gave endothermic values: +22.1 ± 1.3 and +48.7 ± 1.5 kJ mol?1, respectively, for the same sequence.

Thiago O. Carvalho; Ana E. B. Matias; Lilian R. Braga; Sheila M. Evangelista; Alexandre G. S. Prado

133

Solid-liquid phase diagrams of binary aromatic hydrocarbon mixtures from calorimetric studies  

SciTech Connect

The authors describe solid-liquid phase diagrams of binary mixtures of aromatic hydrocarbons obtained from calorimetric studies. The sample of the binary solid mixture is heated at a constant rate until the solid is completely melted. During that process, the heat flux needed is monitored. By examination of the curves of the heat flux versus temperature, the solid-liquid phase diagrams can be constructed. Three binary systems (fluorene-dibenzofuran, dibenzothiophene-dibenzofuran, fluorene-dibenzothiophene) have been studied. It turns out that the fluorene-dibenzofuran system forms a solid solution at any composition, while dibenzothiphene-dibenzofuran and fluorene-dibenzothiophene systems have immiscibility gaps in the solid phases.

Sediawan, W.B.; Gupta, S.; McLaughlin, E. (Louisiana State Univ., Baton Rouge, LA (USA). Dept. of Chemical Engineering)

1989-04-01

134

Analysis of Specific Heat Data for Zinc. Resolution of the Calorimetric and Elastic Theta0 Discrepancy  

Microsoft Academic Search

The low-temperature heat capacity of zinc (in the normal state) has been expressed by Cv=?T+?T3+?T5 over the range from 0.15°K to about 8°K. The new parameters obtained are: ?=1.56×10—4 cal\\/deg2 mole, ?=1.39×10—5 cal\\/deg4 mole, and ?=2.44×10—7 cal\\/deg6 mole. The calorimetric Debye temperature, &THgr;0C, is found to be 322°K which is in reasonable agreement with the elastic value, &THgr;0E, of 328°K.

C. W. Garland; J. Silverman

1961-01-01

135

Measurement And Modeling Of Fe VIII To Fe XVI M-shell Emission In The Extreme Ultraviolet  

NASA Astrophysics Data System (ADS)

The solar EUV emission near 200 Å is presently being studied with high resolution with the Cosmic Hot Interstellar Plasma Spectrometer (CHIPS), which focuses on the emission between 90 and 270 Å, and with the EUV Imaging Spectrometer on Hinode, which focuses on the region 180 to 204 Å and 250 to 290 Å. The Solar EUV Experiment on the TIMED spacecraft also observes this spectral band but with greatly reduced resolution. The spectrum in this region is dominated by emission from moderate charge states of iron. The interpretation of the data relies on accurate and complete plasma emission models, notably CHIANTI. We have performed a series of laboratory measurements of the 3-3 emission from M-shell iron ions. The measurements cover the range 170 - 250 Å and are made at an electron density of about 1011 cm-3. Emission from Fe VIII through Fe XVI has been identified. Excellent agreement with CHIANTI predictions is found. A few weak transitions are noted in the laboratory data that are predicted by CHIANTI to be vanishingly small and should not have been observed. These are tentatively attributed to transitions in Fe XV. A comparison with observations from CHIPS is also presented. This work was supported in part by NASA's Solar and Heliospheric Physics Supporting Research and Technology Program. Work at UC-LLNL was performed under the auspices of the DOE by under Contract W-7405-Eng-48.

Beiersdorfer, Peter; Lepson, J. K.; Hurwitz, M.

2007-05-01

136

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.

Gentili, Rodolfo; Gentili, Elio; Sgorbati, Sergio

2009-01-01

137

MEASUREMENT OF THE Fe VIII-Fe XVI 3-3 EMISSION IN THE EXTREME ULTRAVIOLET AND COMPARISON WITH CHIANTI  

SciTech Connect

Laboratory measurements of the n = 3 to n = 3 emission from M-shell iron ions are presented and compared to synthetic spectra from the CHIANTI spectral model. The measurements cover the range 170-290 Angstrom-Sign and are made at an electron density of about 10{sup 11} cm{sup -3}. Emission from Fe VIII through Fe XVI has been identified. Excellent agreement with CHIANTI predictions is found for most lines. Twenty weaker features are noted in the laboratory data that are either absent in CHIANTI or have recently been added and correspond to lines that have not been verified by experimental measurements. A few of these lines may have already been observed (but not yet identified) in the Sun. The features are attributed to emission from various charge states of iron, notably Fe IX and Fe XIII, and two features have been identified as transitions in Fe VIII, i.e., the 3p{sup 6}3d {sup 2}D{sub 5/2}-3p {sup 5}3d{sup 2} {sup 2}P{sub 3/2} and the 3p {sup 6}3d {sup 2}D{sub 3/2}-3p {sup 5}3d{sup 2} {sup 2}P{sub 1/2} transitions at 225.25 {+-} 0.12 and 226.35 {+-} 0.10 Angstrom-Sign , respectively. Seven lines in Fe XI, Fe XII, and Fe XIII between 200 and 205 Angstrom-Sign are noted for which the wavelengths in the CHIANTI database disagree with those in the current database of the National Institute of Standards and Technology. Our measurements of five of these lines appear to agree with the assignments used in CHIANTI.

Beiersdorfer, P.; Lepson, J. K. [Space Sciences Laboratory, University of California, Berkeley, CA 96720 (United States)

2012-08-01

138

Emission Line Spectra from Fe VII to XVI in the Soft X-ray and Extreme Ultraviolet  

NASA Astrophysics Data System (ADS)

Stellar coronae are rich emitters of iron radiation in the soft x-ray and EUV. This spectral region has been opened up first by the EUV Explorer and now by the Chandra X-ray Observatory for detailed observations with high resolution. Lines in this region are a valuable diagnostic tool for temperature and density, but accurate analysis and interpretation requires accurate spectral models and data. We have shown in previous laboratory measurements that the line lists available for the low charge states of iron, especially Fe VII through Fe XIII are strikingly incomplete. Many of the lines left out in the line lists are weak, but because there are many of them, a substantial amount of spectral flux (more than 50%) is missing. Incomplete accounting of these lines can have marked consequences when modeling the coronae of cool stars, such as ? Cen, both by underestimating the flux of the lowest iron charge states and by incorrect assignments of the base level of those strong lines that sit on top of the flux caused by many unresolved weak lines. We are addressing this problem by using the unique spectroscopic abilities of the Lawrence Livermore Electron Beam Ion Trap to compile a catalogue of the relevant line emission in the soft x-ray and EUV region. As part of this catalogue we present here spectra and line lists for Fe VII - Fe XVI between 50-140 Å. Our line lists include wavelengths and line intensities that allow us to estimate the contributions from unresolved lines relative to those of known lines from the same charge state. We also compare these line lists and spectra with the MeKa and CHIANTI models and HULLAC calculations.

Lepson, J. K.; Beiersdorfer, P.; Brown, G. V.; Kahn, S. M.; Liedahl, D. A.; Utter, S. B.

2000-10-01

139

Calorimetric electron telescope mission. Search for dark matter and nearby sources  

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, ISS. Major scientific objective is a search for nearby cosmic ray sources and dark matter by carrying out a precise measurement of the electrons in 1 GeV-20 TeV and the gamma-rays in 20 MeV-several TeV. CALET has, moreover, a capability to measure cosmic ray H, He and heavy ions up to 1000 TeV. It will also have a function to monitor the solar activity and the gamma-ray bursts. The phase A study has started on a schedule of the launch in early 2014 by the H-II Transfer Vehicle, HTV, for a 5-year observation.

Torii, Shoji; CALET Collaboration

2011-02-01

140

Calorimetric measurements of inward-flowing fraction for complex glazing and shading systems  

SciTech Connect

This paper presents a calorimetric measurement of layer-specific inward-flowing fractions of absorbed solar energy for a number of geometric configurations common in fenestrations with shading. The inward-flowing fractions are found to be relatively insensitive to exterior conditions. Results for an interior venetian blind over double glazing agree with thermal model calculations in literature, and are the first layer-specific verification of these calculations. It is argued that a data base of these inward-flowing fractions for a suitably broad class of geometries will make possible the determination of solar heat gain coefficient from noncalorimetric measurements of solar-optical properties of complex fenestration components, a procedure termed solar-thermal separation.

Klems, J.H.; Kelley, G.O.

1995-05-01

141

Calorimetric study on the effect of 60Co ?-rays on the growth of microorganisms  

NASA Astrophysics Data System (ADS)

Using a calorimeter equipped with 24 sample units, the heat evolution from growing Saccharomyces cerevisiae, Escherichia coli and spores of Bacillus pumilus and Bacillus stearothermophilus was detected in the form of growth thermograms. Irradiation with 60Co ?-rays affected the growth pattern, which was used for a quantitative analysis of the effect on microorganisms. Irradiation of B. pumilus and B. stearothermophilus spores led to dose-dependent delays in growth, indicating a bactericidal effect. In case of 60Co ?-irradiated S. cerevisiae, a dose-dependent reduction of the growth rate constant was observed together with the retardation in growth, indicating a combination of bactericidal and bacteriostatic effects. An equation to determine the number of survivors on the basis of the retardation in growth t? and the growth rate constant /? was developed, which proved the opportunity to use the calorimetric technique in predictive microbiology.

Wirkner, Sandra; Takahashi, Katsutada; Furuta, Masakazu; Hayashi, Toshio

2002-03-01

142

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

143

Calorimetric and dynamic light-scattering investigation of cationic surfactant--DNA complexes.  

PubMed

By means of combined calorimetric and dynamic light-scattering measurements, we have investigated the conformational behavior of DNA chains after thermal melting in the presence of a cationic surfactant at different concentrations, up to a surfactant-to-phosphate group molar ratio close to unity. Both the specific heat capacity, C(ex)(p) and the hydrodynamic radius R of the DNA chains provide support for the existence of two structural arrangements with different thermal stabilities, coexisting in the bulk solution. Although a component remains an elongated unfolded DNA chain originated in the thermal denaturation, the second component, consisting of DNA-surfactant complexes, assumes a compact structure with an average size of about 80 nm, whose thermal denaturation occurs at temperatures higher than 100 degrees C. PMID:17134241

Marchetti, S; Onori, G; Cametti, C

2006-12-01

144

Evidence of Landau tricritical behaviour in TGSe by calorimetric measurements: effect of a weak uniaxial stress  

NASA Astrophysics Data System (ADS)

The paraelectric-ferroelectric phase transition of a single crystal of triglycine selenate TGSe, whose first- or second-order character is controversial, has been studied using a high sensitivity calorimetric technique. The specific heat of a highly pure TGSe has been measured and no evidence of latent heat has been found. The anomalous part of the specific heat shows Landau tricritical behaviour. Experimental data have been fitted to a 2-6 Landau potential, whose coefficients have also been obtained. A weak uniaxial stress applied along the ferroelectric axis (10 bar) decreases the anomalous part of the specific heat. This effect is different for cooling and heating runs. The equilibrium data are those obtained on heating that fit to a 2-4-6 Landau potential, which indicates that the transition shifts to second order with the effect of uniaxial stress.

Romero, F. J.; Gallardo, M. C.; Jiménez, J.; Czarnecka, A.; Koralewski, M.; del Cerro, J.

2004-11-01

145

Radioactivity measurements of metallic [sup 192]Ir sources by calorimetric methods  

SciTech Connect

The necessity of establishing the traceability of dose measurement in brachytherapy [sup 192]Ir sources is realized by physicians and researchers in the medical field. Standard sources of various shapes such as [open quotes]hairpin,[close quotes] [open quotes]single pin,[close quotes] [open quotes]thin wire,[close quotes] and [open quotes]seed[close quotes] for calibrating ionization chambers in hospitals are being demanded. Nominal activities of not only these source products but also the standard sources have been so far specified by [open quotes]apparent[close quotes] values. Determination of [open quotes]absolute[close quotes] activity by an established means such as 4pi-beta-gamma coincidence counting is not practical because quantitative dissolution of metallic iridium is very difficult. We tried to determine the [open quotes]absolute[close quotes] activity by a calorimetric method in a fully nondestructive way.

Genka, Tsuguo; Iwamoto, Seikichi; Takeuchi, Norio (Japan Atomic Energy Research Institute, Ibaraki-ken (Japan))

1992-01-01

146

Simulation work on calorimetric energy resolution for the TAC-PF Detector  

NASA Astrophysics Data System (ADS)

According to the Turkish Accelerator Center (TAC) project, a tau-charm factory is proposed based on colliding a 1 GeV electron beam against a 3.5 GeV positron beam. The Particle Factory (TAC-PF) detector will be constructed for the detection of the producing particles from this collision. PbWO4 and CsI(Tl) crystals are considered for the construction of the electromagnetic calorimeter. The photons generated from incident particles in the crystal material are detected by Avalanche photodiodes (APD) or PIN photodiodes placed at the end of the crystal. In this work, the contribution to the calorimetric energy resolution from both the shower fluctuations in the crystal and photoelectron statistics in the detectors have been simulated for PbWO4-APD and PbWO4-PIN combinations.

Tapan, Ilhan; Kocak, Fatma

2012-12-01

147

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

148

Interaction of methotrexate, folates, and pyridine nucleotides with dihydrofolate reductase: calorimetric and spectroscopic binding studies.  

PubMed Central

The thermodynamic parameters, deltaG, deltaH, and deltaS characterizing the tight binding of methotrexate, folates, and pyridine nucleotides to chicken liver dihydrofolate reductase (5,6,7,8-tetrahydrofolate: NADP+ oxidoreductase, EC 1.5.1.3) have been determined from calorimetric and fluorescence measurements. At 25 degrees the binding of NADPH and NADP+ is characterized by small negative enthalpies and large positive entropies whereas the binding of the folates and methotrexate is accompanied by large negative enthalpies and small negative entropies. In addition, the enthalpy of methotrexate-enzyme interaction demonstrates a proton transfer associated with binding; this is not the case with folate and dihydrofolate, thus confirming the conclusions drawn from the observed difference spectra characteristic of the interaction of methotrexate and substrates with the enzyme. The implications of these results are discussed in terms of the nature of the binding process, conformational changes in the enzyme, and the nature of the active site region.

Subramanian, S; Kaufman, B T

1978-01-01

149

Monoclinic to tetragonal transformations in hafnia and zirconia: A combined calorimetric and density functional study  

NASA Astrophysics Data System (ADS)

We use a combination of density functional theory and calorimetric measurements to investigate the monoclinic to tetragonal transition in hafnia and zirconia. We measure the transition enthalpies to be 8.4±0.7kJ/mol in hafnia and, as previously reported, 5.272±0.544kJ/mol in zirconia. Calculated values are 10.21 and 7.50 kJ/mol for hafnia and zirconia, respectively. We formulate a theoretical model of the phase transition consistent with the martnesitic character of the transformations. The transition barriers of 20.3 and 16.3 kJ/mol are estimated for hafnia and zirconia, respectively. We report the phonon spectra of monoclinic and tetragonal phases of both oxides and identify the Raman and IR active modes. The theoretical results compare well with available experiments. We present a comprehensive theoretical comparison of thermodynamic properties of zirconia and hafnia including the temperature dependence of specific heat.

Luo, Xuhui; Zhou, Wei; Ushakov, Sergey V.; Navrotsky, Alexandra; Demkov, Alexander A.

2009-10-01

150

Calorimetric approach for 3D dosimetry of high intensity therapeutic electron beams  

NASA Astrophysics Data System (ADS)

The technique of High Dose Rate Intra-Operative Radiation Therapy (HDR-IORT) consists in the delivery of irradiation immediately after the removal of a cancerous mass, where the same incision is used to focalize the radiation to the tumour bed. Given its particular characteristics, IORT requires dose measurements that are different from those requested in external radiotherapy treatments. The main reason lies in the fact that in this case a single high dose must be delivered to a target volume whose extension and depth will be determined directly during the operation. Because of this peculiar characteristics, until now there is not a dosimetric system able to detect the electron beam giving at once a realtime response and an extensive spatial measure of the absorbed dose. Within the framework of a research project of the INFN (Italian National Institute of Nuclear Physics), we proposed a new system to overcome the problems, Dosiort. The final set-up is a solid phantom having a density approximately 1 g/cm3 with sensitive layers of scintillating fibres at fixed positions in a calorimetric configuration for the containment of electrons of energy 4-12 MeV. The prototype will be able to define the physical and geometrical characteristics of the electron beam (energy, isotropy, homogeneity, etc) and to measure the parameters needed to select the energy, the intensity and the Monitor Units (MU) for the exposition: percentage Depth Dose; beam profiles; isodose curves; values of dose per MU. In this work we present the results obtained by using two orthogonal layers of the calorimetric phantom Dosiort, in particular we report the measurement of the dynamic range of the read-out system and the first qualitative study of the results which can be extracted from the measurements taken in a test beam.

Lamanna, E.; Fiorillo, A. S.; Vena, R.; Berdondini, A.; Bettuzzi, M.; Brancaccio, R.; Casali, F.; Morigi, M. P.; Bilokon, H.; Barca, G.; Castrovillari, F.; Siaka, Y. F. T.

2009-12-01

151

Complexation of manganese(II) by cyclohexano-15-crown-5 in propylene carbonate: Calorimetric and X-ray crystallographic investigation  

Microsoft Academic Search

Calorimetric titrimetry reveals that cyclohexano-15-crown-5 (C15C5) forms a 1:1 complex with Mn(II) ions (2.5 mM) in propylene carbonate (PC) solution to which was added levels of water up to 134 mM. The reaction proceeds with a strong driving force (log K = 4.7-5.0) and is enthalpically driven overall, but the magnitude of the enthalpy change decreases with increasing water concentration

Yanpei Deng; John H. Burns; Bruce A. Moyer

1995-01-01

152

The dynamic shear response of the Zr base bulk metallic glass around the calorimetric glass transition temperature  

Microsoft Academic Search

The dynamic shear response of a bulk Zr55Cu25Ni5Al10Nb5 metallic glass has been investigated in the vicinity of calorimetric glass transition temperature, Tg. Similar to other glass formers, the Zr base bulk metallic glass exhibits typical features of the dynamic glass transition. The intermediate fragility index, m, indicates that the Zr base alloy belongs to the category of relatively strong glass

Q. Wang; J. M. Pelletier; H. Xu; L. Xia; X. H. Tan; Y. D. Dong

2005-01-01

153

Calorimetric Electron Telescope (CALET) to observe cosmic-ray electrons and gamma-rays on the International Space Station  

Microsoft Academic Search

We have proposed to make observations of high energy cosmic rays with CALET (CALorimetric Electron Telescope) on the International Space Station. Our main objective is to observe electrons up to 20TeV to investigate origin and propagation of electrons in the Galaxy. Acceleration in nearby supernovae can lead to contributions to the electron spectrum in energies up to tens of TeV.

Tadahisa Tamura; Shoji Torii

2010-01-01

154

Temperature-modulated differential scanning calorimetric measurements on pre-melting behavior of nascent ultrahigh molecular mass polyethylene  

Microsoft Academic Search

Temperature-modulated differential scanning calorimetric (TMDSC) measurements on nascent ultrahigh molecular mass polyethylene (UHMMPE) in scanning as well as quasi-isothermal mode are presented. From these measurements different processes, which contribute to the modulated heat flow in the pre-melting region, both exothermic and endothermic in character, can be separated. One of them only occur on the first heating of the nascent material.

Günther W. H Höhne; Lada Kurelec; Sanjay Rastogi; Piet J Lemstra

2003-01-01

155

Calorimetric Study of the Diastereomeric Interactions of Enantiomeric Iso-octyl-benzoyloxybenzoate Solutes with a Chiral Liquid Crystal  

Microsoft Academic Search

Precision differential scanning calorimetric (DSC) analysis of the effect of doping cholesteryl nonanoate with the enantiomers of 4-(4-n-hexyloxybenzoyloxy)-isooctyl benzoate (R811 and S811) has been performed. Depressions of the enthalpies of both phase transitions, from crystalline to cholesteric and from cholesteric to isotropic phases, were found to be ? 1.5 times greater for the samples of cholesteryl nonanoate doped with left-handed

Y. K. Yarovoy; Vibha Patel; M. M. Labes

1998-01-01

156

Calorimetric measurements of acidity of templated and non-templated HZSM-5 zeolites and their correlation with catalytic activity  

Microsoft Academic Search

HZSM-5 zeolites with and without template having SiO2\\/Al2O3 ratio ?28 have been synthesised. The acidity of the samples was measured by stepwise temperature programmed desorption of ammonia and calorimetric measurement of ammonia adsorption. The difference in catalytic activity of these samples for aniline alkylation and cumene cracking have been discussed from the point of view of total acidity and relative

Sankarasubbier Narayanan; Asima Sultana; Paul Meriaudeau; Claude Naccache; Aline Auroux; Carine Viornery

1996-01-01

157

Anaerobic metabolism in aerobic mammalian cells: information from the ratio of calorimetric heat flux and respirometric oxygen flux.  

PubMed

Calorimetric and respirometric studies of cultured cells show that both neoplastic and non-neoplastic cell types maintain an anaerobic contribution to their total heat flux. In many mammalian cells this can be explained quantitatively by lactate production observed under fully aerobic conditions. Uncoupling and enhanced futile substrate cycling increase the ratio of heat flux to oxygen flux, the calorimetric-respirometric (CR) ratio. The interpretation of calorimetric and respirometric measurements requires an energy balance approach in which experimentally measured CR ratios are compared with thermochemically derived oxycaloric equivalents. The oxycaloric equivalent is the enthalpy change per mole of oxygen consumed, and equals -470 kJ/mol O2 in the aerobic catabolism of glucose, assuming that catabolism is 100% dissipative (the net efficiency of metabolic heat transformation is zero). CR ratios more negative than -470 kJ/mol O2 have been reported in well-oxygenated cell cultures and are discussed in terms of integrated aerobic and anaerobic metabolism. PMID:2184896

Gnaiger, E; Kemp, R B

1990-04-26

158

First calorimetric determination of heat of extraction of 248Cm in a bi-phasic system  

SciTech Connect

This report presents a summary of the work performed to meet FCR&D level 2 milestone M21SW050201, 'Complete the first calorimetric determination of heat of extraction of 248Cm in a bi-phasic system'. This work was carried out under the auspices of the Thermodynamics and Kinetics FCR&D work package. To complement previous work undertaken under this work package we have extended out heat of extraction studies by di-2-ethyl-hexyl-phosphoric acid to curium. This report also details the heat of extraction of samarium in the same system. This work was performed to not only test the methodology but also to check for consistency with the heats of extraction obtained with those in the prior literature. The heat of extraction for samarium that was obtained in this study was -9.6 kJ mol-1, which is in reasonable agreement with the previously obtained value of -10.9 kJ mol-1. The curium heat of extraction was performed under two sets of conditions and the obtained heats of extraction were in reasonable agreement with each other at -16.0 {+-} 1.1 and -16.8 {+-} 1.5 kJ mol-1.

Leigh R. Martin; Peter R. Zalupski

2011-06-01

159

Calorimetric observation combined with the detection of particle emissions during the electrolysis of heavy water  

NASA Astrophysics Data System (ADS)

Several calorimetric measurements on electrolysis processes for monitoring the ``cold fusion'' event are represented in this work. A Calvet microcalorimeter with its auxiliaries such as amplifier, recorder, computer etc. was used here for measuring the output power generated during these processes. And at the same time, the total electric input power was recorded for comparing with differences between the out power (or the power measured by the calorimeter) and the electric power minus the equivalent of the D2O (or H2O) formation enthalpy (1.54 (voltage) x I (current)) continuously. After a period of cell operation, over about two weeks, a steady production of ``Excess Heat'' could be demonstrated on the recordings. In particular, there are sporadic power ``excursions'' or ``burst'' monitored in uncertain time. There results could not incontestably show that the cold fusion event has been monitored. Because, at the same time, the neutrons, tritiums, and other particles produced during the processes had not been found out by some types of films being able to detect different kinds of particles yet.

Zhang, Zhong L.; Yan, Bao Z.; Wang, Ming G.; Gu, Jin; Tan, Fu

1991-05-01

160

Calorimetric investigation of the structural relaxation of amorphous materials: evaluating validity of the methodologies.  

PubMed

Although the potential advantages of the amorphous solid state is widely recognized among pharmaceutical researchers, its industrial applications have been mainly limited to freeze-dried injectable formulations where the amorphous form is naturally produced. Applications in oral dosage forms have been limited due, at least in part, to the poor state of knowledge regarding physical properties and stability of amorphous materials. Relaxation behavior is perhaps one of the most important physical characteristics of amorphous materials because relaxation kinetics are closely related to physical and chemical stability. Although recent developments in calorimetry methodology have facilitated detailed characterization of relaxation behavior, some experimental difficulties remain, and quantitative analysis of structural relaxation is still under development. This review focuses on the calorimetric investigation of the structural relaxation of drugs and excipients, and discusses the difficulties in the experimental evaluation of the relaxation time by those methods. We also present an original investigation of the impact of increases in relaxation time during an annealing experiment on the values of relaxation time, tau, and stretched exponential constant, beta, obtained from analysis of the experiment according to the Kohlraush-Williams-Watts kinetic model. Using results from a numerical simulation, we find that the values of tau and beta obtained from the data analysis are too large and too small, respectively, but the value of stretched relaxation time, tau(beta), remains reliable. The time dependence of the relaxation time is likely to play an important role in the non-Arrhenius behavior of pharmaceutical glasses. PMID:15793805

Kawakami, Kohsaku; Pikal, Michael J

2005-05-01

161

Thermal transport across incommensurate phases in potassium selenate: photo-pyroelectric and calorimetric measurements.  

PubMed

The thermal transport properties-thermal diffusivity, thermal conductivity and specific heat capacity-of potassium selenate crystal have been measured through the successive phase transitions, following the photo-pyroelectric thermal wave technique. The variation of thermal conductivity with temperature through the incommensurate (IC) phase of this crystal is measured. The enhancement in thermal conductivity in the IC phase is explained in terms of heat conduction by phase modes, and the maxima in thermal conductivity during transitions is due to enhancement in the phonon mean free path and the corresponding reduction in phonon scattering. The anisotropy in thermal conductivity and its variation with temperature are reported. The variation of the specific heat with temperature through the high temperature structural transition at 745 K is measured, following the differential scanning calorimetric method. By combining the results of photo-pyroelectric thermal wave methods and differential scanning calorimetry, the variation of the specific heat capacity with temperature through all the four phases of K(2)SeO(4) is reported. The results are discussed in terms of phonon mode softening during transitions and phonon scattering by phase modes in the IC phase. PMID:21715826

Philip, J; Manjusha, M V

2008-12-15

162

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

163

A ternary feldspar-mixing model based on calorimetric data: development and application  

NASA Astrophysics Data System (ADS)

A mixing model for high structural state ternary feldspars in the NaAlSi3O8-KAlSi3O8-CaAl2Si2O8 system is presented based exclusively on calorimetric and volumetric measurements. Comparisons with existing mixing models, which are based on phase-equilibrium experiments, reveal distinct differences. The incorporation of K into Ca-rich plagioclase and of Ca into K-rich alkali feldspar is more strongly limited by our calorimetry-based model, whereas the stability field of Na-rich feldspars is broadened. Natural feldspar assemblages from well-studied magmatic and high-grade metamorphic rocks (i.e. a teschenite sill in Scotland, the Klokken syenogabbro in Greenland, and a granulite-facies metapelite in Sri Lanka) were used to test the mixing models. It was found that the new model largely eliminates discrepancies between observed and predicted feldspar compositions that were present in earlier attempts. The reasons for the problems associated with phase-equilibrium based mixing models are discussed.

Benisek, Artur; Dachs, Edgar; Kroll, Herbert

2010-09-01

164

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

165

Europium(III) tetrakis(?-diketonate) complex as an ionic liquid: a calorimetric and spectroscopic study.  

PubMed

An intrinsic photoluminescent ionic liquid based on europium(III) tetrakis(?-diketonate) complex with a tetraalkylphosphonium as counterion was synthesized. Calorimetric measurements showed a melting point at 63 °C, which allows the ionic liquid classification. When cooling the material from the liquid state, metastable supercooled ionic liquid is obtained, as seen from NMR spectroscopy as well. Eu(III) photoluminescence is clearly observed while the absorption spectra of the ligand is dominant, showing the antenna effect. This was confirmed with submicrosecond time scale luminescence spectroscopy, where a rise of Eu(III) emission is observed with the correspondent decay of the ligand excited state. Temperature effects in the photoluminescence are also shown, being prominent above the melting point where the intensity decreases with Arrhenius behavior. Eu(III) luminescence decays also show features characteristic of energy migration between homologue Eu(III) species. Solvent effects were also studied by NMR and Luminescence spectroscopies, highlighting that the nucleophilicity of organic solvents such as n-alcohols leads to a coordination with Eu(III), which ultimately compromises the stability of the complex. PMID:23477603

Pereira, Cláudia C L; Dias, Sofia; Coutinho, Isabel; Leal, J P; Branco, Luís C; Laia, César A T

2013-03-11

166

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

167

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

168

Calorimetric measurement of afterheat in target materials for the accelerator production of tritium  

SciTech Connect

The estimate of afterheat in a spallation target of lead (Pb) or tungsten (W), by calorimetry, is the purpose of this experiment in support of the Accelerator Production of Tritium (APT). Such measurements are needed to confirm code calculations, these being the only practical way of gaining this type of information in a form suitable to aid the design of the APT machine. Knowledge of the magnitude and duration of afterheat resulting from decay of activation products produced by proton bombardment of the target is necessary to quantify APT safety assumptions, to design target cooling and safety systems, and to reduce technical risk. Direct calorimetric measurement of the afterheat for the appropriate incident proton energies is more reliable than the available alternative, which is indirect, based on data from gamma-ray spectroscopy measurements. The basic concept, a direct measurement of decay afterheat which bypasses the laborious classical way of determining this quantity, has been demonstrated to work. The gamma-ray energy given off by the decay products produced in the activation of lead or tungsten with high-energy protons apparently does represent a significant fraction of the total decay energy. A calorimeter designed for measurement of isotopes decaying by alpha emission must be modified to reduce energy lost with escaping gamma rays. Replacement of the aluminum liner with a tungsten liner in the SSC measurement chamber resulted in a 270% increase in measured heat, proving that the energy loss in the earlier (1992) measurements was significant. Gamma-ray measurements are needed to confirm the gamma-ray absorption calculations for the calorimeter to determine the correction for loss of heat due to transmission of high-energy gamma rays through the calorimeter walls. The experiments at BLIP have shown that calorimetry can be a useful tool in measuring the afterheat in APT target materials.

Perry, R.B. [Argonne National Lab., IL (United States). Electronics and Computing Technologies Div.; Zucker, M.S. [Brookhaven National Lab., Upton, NY (United States)

1994-06-01

169

High-resolution differential scanning calorimetric analysis of the subunits of Escherichia coli aspartate transcarbamoylase.  

PubMed

The thermal denaturation of the catalytic (c3) and regulatory (r2) subunits of Escherichia coli aspartate transcarbamoylase (c6r6) in the absence and presence of various ligands has been studied by means of highly sensitive differential scanning calorimetry. The denaturation of both types of subunit is irreversible as judged by the facts that the proteins coagulate when heated and that no endotherm is observed when previously scanned protein is rescanned. Despite this apparent irreversibility, there is empirical justification for analyzing the calorimetric data in terms of equilibrium thermodynamics as embodied in the van't Hoff equation. The observed curves of excess apparent specific heat vs. temperature are asymmetric and can be expressed within experimental uncertainty as the sums of sequential two-state steps, a minimum of two steps being required for r2 and three for c3. As previously reported [Vickers, K. P., Donovan, J. W., & Schachman, H. K. (1978) J. Biol. Chem. 253, 8493-8498], the addition of the effectors ATP and CTP raises the denaturation temperature of r2 and lowers that of c3 while the addition of the bisubstrate analogue N-(phosphonoacetyl)-L-aspartate raises the denaturation temperature of c3 and lowers that of r2. These effects vary with ligand concentration in the manner expected from the van't Hoff equation, indicating that they are simply manifestations of Le Chatelier's principle rather than being due to "stabilization" or "destabilization" of the proteins. The denaturational enthalpy is increased in those cases of ligand binding in which the denaturation temperature is increased, because of the contribution from the enthalpy of dissociation of the ligand. PMID:3910085

Edge, V; Allewell, N M; Sturtevant, J M

1985-10-01

170

Calorimetric studies of the kinetic unfreezing of molecular motions in hydrated lysozyme, hemoglobin, and myoglobin.  

PubMed Central

Differential scanning calorimetric (DSC) studies of the glassy states of as-received and hydrated lysozyme, hemoglobin, and myoglobin powders, with water contents of < or = 0.25, < or = 0.30, and < or = 0.29 g/g of protein, show that their heat capacity slowly increases with increasing temperature, without showing an abrupt increase characteristic of glass-->liquid transition. Annealing (also referred to as physical aging) of the hydrated proteins causes their DSC scans to show an endothermic region, similar to an overshoot, immediately above the annealing temperature. This annealing effect appears at all temperatures between approximately 150 and 300 K. The area under these peaks increases with increasing annealing time at a fixed temperature. The effects are attributed to the presence of a large number of local structures in which macromolecular segments diffuse at different time scales over a broad range. The lowest time scale corresponds to the > N-H and -O-H group motions which become kinetically unfrozen at approximately 150-170 K on heating at a rate of 30 K min-1 and which have a relaxation time of 5-10 s in this temperature range. The annealing effects confirm that the individual glass transition of the relaxing local regions is spread over a temperature range up to the denaturation temperature region of the proteins. The interpretation is supported by simulation of DSC scans in which the distribution of relaxation times is assumed to be exceptionally broad and in which annealing done at several temperatures over a wide range produces endothermic effects (or regions of DSC scans) qualitatively similar to those observed for the hydrated proteins.

Sartor, G; Mayer, E; Johari, G P

1994-01-01

171

Calorimetric study of blend miscibility of polymers confined in ultra-thin films  

NASA Astrophysics Data System (ADS)

Miscibility in blends of polystyrene and poly(phenylene oxide) (PS/PPO) confined in thin films (down to 6 nm) was investigated using a recently developed sensitive differential alternating current (AC) chip calorimeter. Comparison of composition dependence of glass transition in thin films with common models should provide information on miscibility. This study focuses on the blend system polystyrene and poly(phenylene oxide) (PS/PPO) because it is thought as a miscible model system in the whole composition range. Furthermore, its local dynamic heterogeneity is already identified by dynamic mechanic thermal analysis (DMTA) and solid state NMR techniques. For this blend, we find that even for the thinnest films (6 nm, corresponding to about half of PPO's radius of gyration Rg) only one glass transition is observed. The composition dependence of Tg is well described by the Fox, Couchman or Gordon-Taylor mixing law that are used for the miscible bulk blends. Although there is a contradicting result on whether Tg decreases with decreasing film thickness between our calorimetric measurements and Kim's elipsometric measurements on the same blend (Kim et al. Macromolecules 2002, 35, 311-313), the conclusion that the good miscibility between PS and PPO remains in ultrathin films holds for both studies. Finally, we show that our chip calorimeter is also sensitive enough to study the inter-layer diffusion in ultrathin films. PS chain in a thin PS/PPO double layer that is prepared by spin coating PPO and PS thin film in tandem will gradually diffuse into the PPO layer when heated above Tg of PS, forming a PSxPPO100-x blend. However, above the PSxPPO100-x blend, there exists an intractable pure PS like layer (˜30 nm in our case) that does not diffuse into the blend beneath even staying at its liquid state over 10 hours.

Jiang, W.; Du, M.; Gu, Q.; Jiang, J.; Huth, H.; Zhou, D.; Xue, G.; Schick, C.

2010-10-01

172

Numerical analysis of the AC loss in a high-TC superconducting cable measured by calorimetric method  

NASA Astrophysics Data System (ADS)

We calculated the AC property in a high-TC superconducting (HTS) cable fabricated by Furukawa Electric Industries Ltd (FEI) by using an electric-circuit (EC) model. The AC loss of the HTS cable is measured by a calorimetric method by FEI. The measured AC loss and the calculated one are almost equal. According to the calculated results, the layer’s currents are uniform on the low transport current. On the high transport current, the layer’s current distribution indicates a drift-current phenomenon.

Noji, H.; Ikeda, K.; Uto, K.; Hamada, T.

2005-09-01

173

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 ...

Riches, Ms.

2007-10-16

174

Carbocyclic compounds  

US Patent & Trademark Office Database

Novel carbocyclic compounds are described. The compounds generally comprise an acidic group, a basic group, a substituted amino or N-acyl and a group having an optionally hydroxylated alkane moiety. Pharmaceutical compositions comprising the inhibitors of the invention are also described. Methods of inhibiting neuraminidase in samples suspected of containing neuraminidase are also described. Antigenic materials, polymers, antibodies, conjugates of the compounds of the invention with labels, and assay methods for detecting neuraminidase activity are also described.

Bischofberger; Norbert W. (San Carlos, CA); Kim; Choung U. (San Carlos, CA); Lew; Willard (San Mateo, CA); Liu; Hongtao (Foster City, CA); Williams; Matthew A. (Foster City, CA)

1998-06-09

175

Differential-scanning-calorimetric study of the irreversible thermal denaturation of 8 kDa cytotoxin from the sea anemone Radianthus macrodactylus.  

PubMed Central

A differential-scanning-calorimetric study of the thermal denaturation of a sea-anemone (Radianthus macrodactylus) 8 kDa cytolytic toxin was carried out. The calorimetric traces were found to be irreversible and scan-rate-dependent under the experimental conditions employed. Scan-rate-dependent thermograms were explained in terms of a two-state kinetic model N k -->D, where k is a first-order kinetic constant that changes with temperature as given by the Arrhenius equation, N is the native state of the toxin, and D the denatured one.

Zhadan, G G; Shnyrov, V L

1994-01-01

176

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

177

Urea-induced dissociation and unfolding of dodecameric glutamine synthetase from Escherichia coli: calorimetric and spectral studies.  

PubMed Central

Urea-induced dissociation and unfolding of manganese.glutamine synthetase (Mn.GS) have been studied at 37 degrees C (pH 7) by spectroscopic and calorimetric methods. In 0 to approximately 2 M urea, Mn.GS retains its dodecameric structure and full catalytic activity. Mn.GS is dissociated into subunits in 6 M urea, as evidenced by a 12-fold decrease in 90 degrees light scattering and a monomer molecular weight of 51,800 in sedimentation equilibrium studies. The light scattering decrease in 4 M urea parallels the time course of Trp exposure but occurs more rapidly than changes in secondary structure and Tyr exposure. Early and late kinetic steps appear to involve predominantly disruption of intra-ring and inter-ring subunit contacts, respectively, in the layered hexagonal structure of Mn.GS. The enthalpies for transferring Mn.GS into urea solutions have been measured by titration calorimetry. After correcting for the enthalpy of binding urea to the protein, the enthalpy of dissociation and unfolding of Mn.GS is 14 +/- 4 cal/g. A net proton uptake of approximately 50 H+/dodecamer accompanies unfolding reactions. The calorimetric data are consistent with urea binding to multiple, independent sites in Mn.GS and the number of binding sites increasing approximately 9-fold during the protein unfolding.

Zolkiewski, M.; Nosworthy, N. J.; Ginsburg, A.

1995-01-01

178

Development of Metallic Magnetic Calorimeters for High Precision Measurements of Calorimetric 187Re and 163Ho Spectra  

NASA Astrophysics Data System (ADS)

The measurement of calorimetric spectra following atomic weak decays, beta ( ?) and electron capture (EC), of nuclides having a very low Q-value, can provide an impressively high sensitivity to a non-vanishing neutrino mass. The achievable sensitivity in this kind of experiments is directly connected to the performance of the used detectors. In particular an energy resolution of a few eV and a pulse formation time well below 1 ?s are required. Low temperature Metallic Magnetic Calorimeters (MMCs) for soft X-rays have already shown an energy resolution of 2.0 eV FWHM and a pulse rise-time of about 90 ns for fully micro-fabricated detectors. We present the use of MMCs for high precision measurements of calorimetric spectra following the ?-decay of 187Re and the EC of 163Ho. We show results obtained with detectors optimized for 187Re and for 163Ho experiments respectively. While the detectors equipped with superconducting Re absorbers have not yet reached the aimed performance, a first detector prototype with a Au absorber having implanted 163Ho ions already shows excellent results. An energy resolution of 12 eV FWHM and a rise time of 90 ns were measured.

Ranitzsch, P. C.-O.; Porst, J.-P.; Kempf, S.; Pies, C.; Schäfer, S.; Hengstler, D.; Fleischmann, A.; Enss, C.; Gastaldo, L.

2012-06-01

179

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

PubMed

Calorimetric and fluorescence techniques were used to characterize the binding of aminoglycosides-neomycin, paromomycin, and ribostamycin, with 5'-dA(12)-x-dT(12)-x-dT(12)-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 T(m) for triplex decreases with increasing pH value in the presence of neomycin, while the T(m) 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 (Deltan) as 0.29 and 0.40 for neomycin and paromomycin interaction with 5'-dA(12)-x-dT(12)-x-dT(12)-3', respectively. (4) The specific heat capacity change (DeltaC(p)) determined by ITC studies is negative, with more negative values at lower salt concentrations. From 100 mM to 250 mM KCl, the DeltaC(p) ranges from -402 to -60 cal/(mol K) for neomycin. At pH 5.5, a more positive DeltaC(p) is observed, with a value of -98 cal/(mol K) at 100 mM KCl. DeltaC(p) 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 AC(50) (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

2010-02-16

180

Binding of lanthanum and gadolinium ions to concanavalin A studied calorimetrically at 25 degrees C.  

PubMed

The interaction between Concanavalin A (ConA) and the lanthanide ions La3+ and Gd3+ has been studied calorimetrically at 25 degrees C. The measurements were carried out at a pH of 4.5, where the protein exists prevailingly as a dimer. Calorimetry allows the direct determination of the binding enthalpy and the evaluation of both the apparent association constant, and the apparent free energy and entropy. Three groups of data were collected. The first concerns the interaction of the 'native' protein, i.e., fully metallized with Mn2+ and Ca2+, with the lanthanides. The second concerns the interaction of the completely demetallized protein with La3+ and Gd3+. Finally, the affinity of each complex was tested for the specific sugar alpha-methylmannopyranoside. The analysis of the thermodynamic parameters obtained, led to the following conclusions: 1) a specific site, named S3, exists on the protein for the lanthanides, distinct from the S1 site of the transition metal and from the S2 site, specific for calcium. There is only one S3 site per protomer when the protein has Mn2+ in S1 and Ca2+ in S2. Moreover, there is no appreciable competition for S1 and S2 from the lanthanides. The 'native' protein, metallized with La3+ or Gd3+, is a fully functional protein. 2) The demetallized protein (ApoCon A) has at least two sites per protomer for the lanthanides. The hypothesis is that, besides the S3 site, the lanthanides, in the absence of Mn2+, can also occupy the S1, but not the S2, site. The protein metallized only with gadolinium ion is completely inactive toward the interaction with the mannoside. The same happens when, along with gadolinium, only calcium or manganese is present. Hence, in the absence of the transition metal in S1 or of calcium in S2, the protein is not in the conformation suitable to interact with its specific substrate. PMID:2637041

Barone, G; Castronuovo, G; Del Vecchio, P; Elia, V; Guarrata, P

1989-12-01

181

Calorimetric Measurements of Energy Release in Nb-Ti-50 Superconducting Alloy in Irradiation by 8.5 GeV Protons.  

National Technical Information Service (NTIS)

The calorimetric method of measurements of energy release in the Nb-Ti-50 alloy caused by irradiation by 8.5 GeV proton beam is described. The results of measurements at helium temperatures for sample 2 mm thick are given. The obtained value of energy rel...

I. N. Goncharov V. M. Drobin N. M. Osipova S. I. Yakovlev L. N. Zaitsev

1979-01-01

182

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

2007-10-30

183

A calorimetric approach to the study of the interactions of cytidine-3'-phosphate with bovine seminal ribonuclease.  

PubMed

A calorimetric study at 25 degrees C is reported on the interaction between allosteric bovine seminal ribonuclease and cytidine-3'-phosphate. The results are compared with those obtained under identical experimental conditions for the interaction of pancreatic ribonuclease A and the same nucleotide. The analysis of the data provides evidence that the binding sites of seminal ribonuclease for cytidine-3'-phosphate are not equivalent, in agreement with previous equilibrium dialysis studies. A model with two sites with different affinities toward the nucleotide, the site with higher affinity resembling the binding site of pancreatic ribonuclease, is proposed. The values calculated for the thermodynamic parameters provide an insight of the forces involved in the interaction of the two enzymes with the nucleotide. PMID:2752098

Ambrosino, R; Barone, G; Castronuovo, G; Cultrera, O; Di Donato, A; Elia, V

1989-08-01

184

Calorimetric measurements of the ''equivalent series resistance'' of low-loss, high repetition rate pulse discharge capacitors  

SciTech Connect

In high repetition rate pulsed circuits, component losses are a major design consideration. Accurate means of calculating the dissipation loss is essential for determining efficiency and in designing cooling systems for removal of associated heat. In high voltage systems, dielectric loss can be a major contributor to power dissipation. Total energy dissipation in a capacitor is the sum of dielectric, tab, corona, lead connections, and skin effect losses. Dielectric loss is also dependent on temperature, voltage, and frequency which adds to the complexity of determining an accurate value. The total loss component can be described by the ''equivalent series resistance'' or ESR. In this paper we will review the most common electrical methods used to measure the ESR and particulars that must be considered with these techniques. Finally we will describe calorimetric methods of ESR determination that are accurate regardless of frequency and voltage and the ESR values of a variety of commercially available pulsed discharge capacitors.

McDuff, G.G.; Rust, K.R.

1986-01-01

185

Ti 4+ in silicate melts: Energetics from high-temperature calorimetric studies and implications for melt structure  

NASA Astrophysics Data System (ADS)

The drop solution calorimetric method was used to determine the enthalpy of solution of rutile ( ?Hsol) in silicate melts. High-temperature (1760 K) in situ calorimetric data show that ?Hsol is a strong function of melt composition. For potassium endmember melts, potassium disilicate, and trisilicate, ?Hsol increases (from 28-48 kJ/mol) as TiO 2 concentration increases. For calcium disilicate melts ?Hsol is constant (69 kJ/mol). For mixed potassium-calcium compositions, ?Hsol is more exothermic than for the calcium endmember but remains constant at 43.9 kJ/mol. The enthalpy of solution of rutile at 1760 K and the enthalpy of mixing at 978 K derived from lead borate solution calorimetry for Ti-bearing potassium aluminosilicate glasses have been used to model the homogeneous equilibria among Ti species in the potassium-bearing melts. The energetics of Ti speciation were used to predict quantitatively the excess heat capacity of titanium-bearing silicate melts previously observed by Lange and Navrotsky (1993), suggesting that heat capacities, mixing properties, and rutile solubility are all controlled by the temperature and composition dependence of the same set of homogenous equilibria among titanium species in the melts. Though knowing the exact microscopic nature of these species is not necessary for macroscopic thermodynamic modeling, the model is consistent with a gradual variation with composition and temperature in mid-range order involving five-coordinated titanyl groups and alkali atoms as proposed by Farges et al. (1996a,b,c).

Gan, Hao; Wilding, Martin C.; Navrotsky, Alexandra

1996-11-01

186

Metallic compounds  

Microsoft Academic Search

Summary 1.The chemical interaction between metals or between metals and metalloids, which results in the formation of various substances having metallic properties, is characterized essentially by the formation of metallic solutions and metallic compounds.2.The chemical resemblance. and differences between metallic elements, which are associated with the dispositions of the elements in the same or different group of the periodic system,

I. I. Kornilo

1953-01-01

187

Energetics of hydrogen bonding in proteins: a model compound study.  

PubMed Central

Differences in the energetics of amide-amide and amide-hydroxyl hydrogen bonds in proteins have been explored from the effect of hydroxyl groups on the structure and dissolution energetics of a series of crystalline cyclic dipeptides. The calorimetrically determined energetics are interpreted in light of the crystal structures of the studied compounds. Our results indicate that the amide-amide and amide-hydroxyl hydrogen bonds both provide considerable enthalpic stability, but that the amide-amide hydrogen bond is about twice that of the amide-hydroxyl. Additionally, the interaction of the hydroxyl group with water is seen most readily in its contributions to entropy and heat capacity changes. Surprisingly, the hydroxyl group shows weakly hydrophobic behavior in terms of these contributions. These results can be used to understand the effects of mutations on the stability of globular proteins.

Habermann, S. M.; Murphy, K. P.

1996-01-01

188

Calorimetric study of glass transition in molecular liquids consisting of globular associates: dicyclorohexylmethanol and tricyclohexylmethanol.  

PubMed

Heat capacities of liquids and liquid-quenched glasses (LQGs) of dicyclorohexylmethanol (DCHM) and tricyclohexylmethanol (TCHM) were measured by adiabatic calorimetry. Upon cooling the liquid compounds, they undergo glass transitions around 250 and 265 K, respectively. Temperature dependence of the FT-IR spectrum of TCHM liquid showed the gradual formation of dimers in the supercooled state with decreasing temperature. The magnitude of heat capacity jump at glass transition is discussed through a comparison with other low-molecular mass LQG. Combining the present results with previous heat capacity results on crystalline TCHM, residual entropies of LQG and standard thermodynamic quantities are established for both compounds. PMID:22414072

Yamamura, Yasuhisa; Suzuki, Yu-ta; Sumita, Masato; Saito, Kazuya

2012-03-23

189

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

190

New methodology for simultaneous volumetric and calorimetric measurements: Direct determination of {alpha}{sub p} and C{sub p} for liquids under pressure  

SciTech Connect

A new batch cell has been developed to measure simultaneously both isobaric thermal expansion and isobaric heat capacity from calorimetric measurements. The isobaric thermal expansion is directly proportional to the linear displacement of an inner flexible below and the heat capacity is calculated from the calorimetric signal. The apparatus used was a commercial Setaram C-80 calorimeter and together with this type of vessels can be operated up to 20 MPa and in the temperature range of 303.15-523.15 K, In this work, calibration was carried out using 1-hexanol and subsequently both thermophysical properties were determined for 3-pentanol, 3-ethyl-3-pentanol, and 1-octanol at atmospheric pressure, 5 and 10 MPa, and from 303.15 to 423.15 K in temperature. Finally experimental values were compared with the literature in order to validate this new methodology, which allows a very accurate determination of isobaric thermal expansion and isobaric heat capacity.

Casas, L. M. [Departamento de Fisica Aplicada, Facultad de Ciencias Experimentales, Universidad de Vigo, Lagoas Marcosende s/n, 36310 Vigo (Spain); Plantier, F.; Bessieres, D. [Laboratoire de Thermodynamique et Energetique des Fluides Complexes-UMR 5150, Universite de Pau et des Pays de l'Adour, BP 1155, 64013 Pau (France)

2009-12-15

191

A XANES study of the structural role of lead in glazes from decorated tiles, XVI to XVIII century manufacture  

NASA Astrophysics Data System (ADS)

Aged lead-rich, tin-opacified glazes from polychrome tiles manufactured in the 16th 18th century were studied to ascertain the structural role of lead. Glaze fragments with white, blue, yellow, brown and green colouring were analysed using non-destructive X-ray techniques, both laboratorial X-ray diffraction to identify crystalline components and synchrotron-based. Elemental analyses by synchrotron radiation X-ray fluorescence were performed at the former LURE photon microprobe (line D15A at DCI, in Orsay). The instrumental set-up of beamline BM29 at the ESRF, in Grenoble, was applied to collect X-ray absorption spectra at the Pb L3-edge. Natural minerals and synthetics with known crystal structure were used as model oxy-compounds to configure different formal valences and coordinations of lead ions by oxygen anions, and to interpret the effects upon details of X-ray absorption near-edge spectroscopy (XANES) spectra. Experimental evidence supports the general conclusion that lead is hosted by the glassy matrix, irrespective of the glaze colour. Furthermore, it was concluded that lead ions assume coordinations higher than usual for silica glasses, acting as network modifiers in the silica-lime-alkali glasses of ancient tile glazes.

Figueiredo, M. O.; Silva, T. P.; Veiga, J. P.

2006-05-01

192

Thermochemistry of bithiophenes and thienyl radicals. A calorimetric and computational study.  

PubMed

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 degrees = 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 CO(2) (g) and H(2)SO(4) x 115 H(2)O, 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(o) = 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. PMID:19772333

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

2009-10-15

193

Effect of Core Width, Placement, and Condition on Calorimetrically Measured AC Loss and Interstrand Contact Resistance of Stainless-Steel-Cored Rutherford Cables  

Microsoft Academic Search

Calorimetric measurements of AC loss were made on Nb3Sn Rutherford cables furnished with cores of widths 4.5, 5.2, and 10.8 mm in the face-on (FO) and edge-on (EO) orientations of the applied AC field. The resulting FO-measured effective interstrand contact resistances, Rperp,e,f,f., were compared with that of the uncored cable after which it was noted that although the uncored Rperp,e,f,f.

E. W. Collings; M. D. Sumption; E. Barzi; D. Turrioni; R. Yamada; A. V. Zlobin; Y. Ilyin; A. Nijhuis

2008-01-01

194

Phase transitions in bis-triphenyllead (or tin) diacetylenes. Raman and calorimetric study  

NASA Astrophysics Data System (ADS)

Crystals formed by (C 6H 5) 3-X-C ? C-C ? C-X-(C 6H 5) 3, where X is Pb or Sn, and an equimolecular amount of CH 2Cl 2 or CHCl 3 molecules, have been studied. Phase transition temperatures and enthalpies have been determined by DSC. Raman scattering spectra have been recorded: they show that all four compounds belong to the same space group Pa3 in their high- T phases: they suggest that the low- T space group is P2 12 12 1, implying that the diacetylene interchange group is D 2 at all temperatures.

Bertault, M.; Schott, M.; Peretti, P.; Ranson, P.

1984-02-01

195

A calorimetric study of early hydration of alkali-slag cements  

Microsoft Academic Search

This paper examines the early hydration of alkali-slag cements activated by different sodium compounds, such as NaOH, Na2CO3, Na2SiO3.5H2O, Na3PO4, Na2HPO4 and NaF, at 25 and 50 °C. A conduction calorimeter was used to monitor hydration kinetics. It was found that the initial pH of activator solution has an important role in dissolving the slag and in promoting the early

Caijun Shi; Robert L. Day

1995-01-01

196

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 ...

Huggins, Ms.

2012-04-12

197

Complexation of manganese(II) by cyclohexano-15-crown-5 in propylene carbonate: Calorimetric and X-ray crystallographic investigation  

SciTech Connect

Calorimetric titrimetry reveals that cyclohexano-15-crown-5 (C15C5) forms a 1:1 complex with Mn(II) ions (2.5 mM) in propylene carbonate (PC) solution to which was added levels of water up to 134 mM. The reaction proceeds with a strong driving force (log K = 4.7-5.0) and is enthalpically driven overall, but the magnitude of the enthalpy change decreases with increasing water concentration in the case of the Mn(II) nitrate salt. A minor anion effect occurs in which the trifluoromethansulfonate ion gives slightly more negative values of {Delta}H and T{Delta}S than the nitrate ion. Values of log K, however, do not change appreciably with increasing water concentration, nor are they dependent on the anion. The crystal structure of Mn(C15C5)(CF{sub 3}SO{sub 3}){sub 2} was determined, showing that the Mn(II) ion is coordinated by a pentagonal bipyramid of oxygen atoms provided by the equatorial crown {Angstrom}, b=14.145(1) {Angstrom}, c = 13,420(1) {Angstrom} {beta} = 100.31(2){degrees}, V = 5028 {Angstrom}{sup 3}, Z = 8, t = 26 {degrees}C. For 2178 reflections with I > {sigma}(I), and 325 parameters, R(F) = 0.050 and R{sub w}(F) = 0.054.

Deng, Yanpei; Burns, J.H.; Moyer, B.A. [Oak Ridge National Lab., TN (United States)

1995-01-04

198

Calorimetric Low Temperature Detectors for High Resolution X-ray Spectroscopy on Stored Highly Stripped Heavy Ions  

SciTech Connect

The precise determination of the Lamb shift in heavy hydrogen-like ions provides a sensitive test of QED in very strong Coulomb fields, not accessible otherwise, and has also the potential to deduce nuclear charge radii. A brief overview on the present status of such experiments, performed at the storage ring ESR at GSI Darmstadt, is given. For the investigation of the Lyman-{alpha} transitions in Au{sup 78+} or U{sup 91+} ions with improved accuracy, a high-resolution calorimetric low-temperature detector for hard x-rays (E {le} 100 keV) has been recently developed. The detector modules consist of arrays of silicon thermistors and of x-ray absorbers made of high-Z material to optimize the absorption efficiency. The detectors are housed in a specially designed {sup 3}He/{sup 4}He dilution refrigerator which fits to the geometry of the ESR target. The detector performance presently achieved is already close to fulfilling the demands of the Lamb shift experiment. For a prototype detector an energy resolution of {Delta}E{sub FWHM} = 75 eV is obtained for 60-keV x-rays.

Bleile, A.; Egelhof, P.; Kluge, H.J.; Liebisch, U.; McCammon, D.; Meier, H.J.; Sebastian, O.; Stahle, C.K.; Stoehlker, T.; Weber, M.

2000-12-31

199

Calorimetric investigation of the magnetocaloric effect in Ni45Co5Mn37.5In12.5  

NASA Astrophysics Data System (ADS)

A calorimetric investigation of a Ni45Co5Mn37.5In12.5 single crystal has been carried out by combining differential scanning calorimetry (DSC) and heat capacity (C) measurements. The martensitic transition showing a first-order character spread over a wide temperature range, a specific measuring technique of C(T) has been developed. This method—based on a time-resolved analysis of successive heating pulses—was found to yield an entropy change at the transition (?Str) that is very close to that derived from DSC. To investigate the magnetocaloric effect, both the isothermal entropy change ?ST and the adiabatic temperature change ?Tad were derived from heat capacity curves recorded in a series of magnetic fields up to 7 T. The maximum values of ?ST(T, B) were observed to be in accordance with those determined from the Maxwell equation. Furthermore, maximum values of ?Tad(T, B) resulting from the application of 2 T, 5 T and 7 T were found to be equal to -2.3 K, -6.1 K and -9.4 K, respectively.

Guillou, F.; Courtois, P.; Porcar, L.; Plaindoux, P.; Bourgault, D.; Hardy, V.

2012-06-01

200

Calorimetric determination of the enthalpy change for the alpha-helix to coil transition of an alanine peptide in water.  

PubMed Central

The enthalpy change (delta H) accompanying the alpha-helix to random coil transition in water has been determined calorimetrically for a 50-residue peptide of defined sequence that contains primarily alanine. The enthalpy of helix formation is one of the basic parameters needed to predict thermal unfolding curves for peptide helices and it provides a starting point for analysis of the peptide hydrogen bond. The experimental uncertainty in delta H reflects the fact that the transition curve is too broad to measure in its entirety, which precludes fitting the baselines directly. A lower limit for delta H of unfolding, 0.9 kcal/mol per residue, is given by assuming that the change in heat capacity (delta Cp) is zero, and allowing the baseline to intersect the transition curve at the lowest measured Cp value. Use of the van't Hoff equation plus least-squares fitting to determine a more probable baseline gives delta H = 1.3 kcal/mol per residue. Earlier studies of poly(L-lysine) and poly(L-glutamate) have given 1.1 kcal/mol per residue. Those investigations, along with our present result, suggest that the side chain has little effect on delta H. The possibility that the peptide hydrogen bond shows a correspondingly large delta H, and the implications for protein stability, are discussed.

Scholtz, J M; Marqusee, S; Baldwin, R L; York, E J; Stewart, J M; Santoro, M; Bolen, D W

1991-01-01

201

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

2008-09-25

202

Cyclopropane compound  

US Patent & Trademark Office Database

A cyclopropane compound represented by the following formula (A) or a pharmaceutically acceptable salt thereof has orexin receptor antagonism, and therefore has a potencial of usefulness for the treatment of sleep disorder for which orexin receptor antagonism is effective, for example, insomnia: ##STR00001## wherein Q represents --CH-- or a nitrogen atom, R.sub.1a and R.sub.1b each independently represent a C.sub.1-6 alkyl group and the like, R.sub.1c represents a hydrogen atom and the like, R.sub.2a, R.sub.2b, R.sub.2c and R.sub.2d each independently represent a hydrogen atom, a halogen atom, a C.sub.1-6 alkyl group and the like, R.sub.3a, R.sub.3b and R.sub.3c each independently represent a hydrogen atom, a halogen atom and the like, and R.sub.3d represents a hydrogen atom and the like.

Terauchi; Taro (Tsukuba, JP); Takemura; Ayumi (Tsukuba, JP); Doko; Takashi (Tokyo, JP); Yoshida; Yu (Tsukuba, JP); Tanaka; Toshiaki (Tsukuba, JP); Sorimachi; Keiichi (Tsukuba, JP); Naoe; Yoshimitsu (Tsukuba, JP); Beuckmann; Carsten (Tsukuba, JP); Kazuta; Yuji (Tsukuba, JP)

2012-09-18

203

Capillary separations with calorimetric absorbance detection. Final progress report, September 1, 1983-August 31, 1986  

SciTech Connect

Several types of capillary LC columns and modes of laser-based detection were studied in this work. A brief chronological survey of our work precedes a more detailed description of the techniques and our results. We extended our pre-contract work with open capillary LC by preparing bonded-phase columns. Initial experiments involving pulsed double beam thermal lens detection revealed problems with ''cleanly'' focusing the pulsed laser beam through open capillary LC flow cells. Also during the second year, we investigated the use of dynamically modified open capillary columns. Procedures for directly sampling biological samples, such as body fluids, were developed and we also began constructing an ultra-low volume solvent delivery system. During the third year of this contract we are continuing attempts to efficiently pack fused silica columns and evaluating the use of photothermal refraction detection with these columns. Since the volume requirements of open capillary LC are lessened when electrokinetic pumping is employed we have begun exploring capillary electrophoretic separation procedures. By incorporating micelles in the mobile phase we are now able to very efficiently separate a variety of neutral compounds with extremely high efficiency.

Sepaniak, M.J.

1986-03-01

204

Ferroelectric properties of the [N(CH3)4]2CoCl2Br2 compound  

NASA Astrophysics Data System (ADS)

Synthesis, X-ray powder and Raman description are reported for [N(CH3)4]2CoCl2Br2 compound. The calorimetric study shows three endothermic peaks at 289 K, 323 K and 408 K. The compound crystallizes in the orthorhombic system, space group Pnma with a = 12.384 Å, b = 9.058 Å and c = 15.647 Å. The dielectric spectra were measured in the frequency range 10-1-106 Hz and temperature interval from 200 to 305 K. The dielectric permittivity shows that this compound exhibits a ferroelectric-paraelectric phase transition at 290 K. The frequency dependent permittivity is interpreted in the non-Debye model. The temperature dependence of the low frequency limit of the bulk AC conductivity ?dc is well described by the Arrhenius equation: ?dc = ?0 exp(-Ea/kT).

Ben Rhaiem, Abdallah; Jomni, Fathi; Karoui, Karim; Guidara, Kamel

2013-03-01

205

Parallaxes and proper motions. XVI  

NASA Astrophysics Data System (ADS)

Parallaxes and proper motions are presented for 30 stars, most of which are dK-M stars in 20 star fields. Seven of the target stars as well as ten other stars have no previous parallax determinations. Six of the 20 target stars are actually resolved binaries for which both components were measured separately; two of the six are not physical pairs. As in the previous lists in this series, reductions have been made using linear plate constants and results are given to the nearest ten-thousandth of a second of arc and separately in x and y coordinates along with a combined solution. This list is the first in the series which makes full use of the prior selection of parallax stars to achieve the primary goal of the Van Vleck parallax program. This is to determine accurate physical properties and space motions of a large and unbiased sample of unevolved nearby stars of the lower main sequence.

Weis, E. W.; Nations, H. L.; Upgren, A. R.

1983-10-01

206

Innovation Abstracts, Volume XVI, 1994.  

ERIC Educational Resources Information Center

|This volume of 30 one- to two-page abstracts highlights a variety of innovative approaches to teaching and learning in the community college. Topics covered in the abstracts include: (1) music in the biology classroom; (2) pairing English as a second language and freshman composition students in writing activities; (3) moot court exercises in…

Roueche, Suanne D., Ed.

1994-01-01

207

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

208

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

NASA Astrophysics Data System (ADS)

Concurrent calorimetric and interferometric studies have been conducted to investigate the effect that reduction of the base-plate dimensions has on the steady-state performance of the rate of natural convection heat transfer from miniaturized horizontal single plate-fin systems and plate-fin arrays. The effect was studied through comparison of the present results with those of earlier relevant calorimetric, interferometric, or numerical studies. Results shown that a reduction of the base-plate area by 74% increased natural convection coefficient by 1.5 times to 26.0 W m-2 K-1 for single fin systems and by 1.8 times to 18 W m-2 K-1 for fin arrays in the range of the base-plate temperature excess of 20-50°C. A simple correlation for the Nusselt number of miniaturized horizontal plate-fin arrays is proposed in the range of Rayleigh number divided by the number of fins to the 2.7 power from 2 × 10 to 5 × 105.

Harahap, Filino; Lesmana, Herry; Sambegoro, Poetro Lebdo

2010-10-01

209

Identifying the critical point of the weakly first-order itinerant magnet DyCo2 with complementary magnetization and calorimetric measurements  

NASA Astrophysics Data System (ADS)

We examine the character of the itinerant magnetic transition of DyCo2 by different calorimetric methods, thereby separating the heat capacity and latent heat contributions to the entropy—allowing direct comparison to other itinerant electron metamagnetic systems. The heat capacity exhibits a large ?-like peak at the ferrimagnetic ordering phase transition, a signature that is remarkably similar to La(Fe,Si)13, where it is attributed to giant spin fluctuations. Using calorimetric measurements, we also determine the point at which the phase transition ceases to be first order: the critical magnetic field, ?0Hcrit = 0.4 ± 0.1 T and temperature Tcrit = 138.5 ± 0.5 K, and we compare these values to those obtained from analysis of magnetization by application of the Shimizu inequality for itinerant electron metamagnetism. Good agreement is found between these independent measurements, thus establishing the phase diagram and critical point with some confidence. In addition, we find that the often-used Banerjee criterion may not be suitable for determination of first order behavior in itinerant magnet systems.

Morrison, K.; Dupas, A.; Mudryk, Y.; Pecharsky, V. K.; Gschneidner, K. A.; Caplin, A. D.; Cohen, L. F.

2013-04-01

210

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

211

Thermoelectric materials and chalcogenide compounds  

US Patent & Trademark Office Database

A thermoelectric material is disclosed. The thermoelectric material is represented by the following formula; (A.sub.1-aA'.sub.a).sub.4-x(B.sub.1-bB'.sub.b).sub.3-y. A is a Group XIII element and A' may be a Group XIII element, a Group XIV element, a rare earth element, a transition metal, or combinations thereof. A and A' are different from each other. B may be S, Se, Te and B' may be a Groups XIV, XV, XVI or combinations thereof. B and B' are different from each other. a is equal to or larger than 0 and less than 1. b is equal to or larger than 0 and less than 1. x is between -1 and 1 and wherein y is between -1 and 1.

Rhyee; Jong-soo (Suwon-si, KR); Lee; Sang-mock (Yongin-si, KR)

2012-10-30

212

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

213

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

214

Emittance Calorimetric Method.  

National Technical Information Service (NTIS)

A precise measurement of the absorption of weakly absorbing optical material is measured by measuring the temperature rise of the sample when light of the wavelength of interest passes through it. The temperature rise is determined by measuring the emissi...

R. F. Potter D. L. Stierwalt

1977-01-01

215

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

216

Calorimetric Ionization Detector  

SciTech Connect

A new mode of operation for ionization detectors is described. The amount of ionization produced in a detector is determined by measuring the amount of heat generated during the carrier collection process. Very high detection sensitivities, including single carrier detection, may be achieved at cryogenic temperatures. Results from an experimental device operated at T = 0.3K is presented.

Luke, P.N.; Beeman, J.; Goulding, F.S.; Labov, S.E.; Silver, E.H.

1989-07-01

217

Sanskrit Compound Processor  

NASA Astrophysics Data System (ADS)

Sanskrit is very rich in compound formation. Typically a compound does not code the relation between its components explicitly. To understand the meaning of a compound, it is necessary to identify its components, discover the relations between them and finally generate a paraphrase of the compound. In this paper, we discuss the automatic segmentation and type identification of a compound using simple statistics that results from the manually annotated data.

Kumar, Anil; Mittal, Vipul; Kulkarni, Amba

218

Calorimetric Studies of the Energetics of Order-Disorder in the System Mg(1-x)Fe(x)Ca(CO(3))(2)  

SciTech Connect

Calorimetric studies by Chai and Navrotsky (1996) on dolomite-ankerite energetic have been extended by including two additional types of samples: a very disordered stoichiometric MgCa(CO{sub 3}){sub 2} prepared from low temperature aqueous solution and three largely ordered natural samples of intermediate iron content. Combining these data with previous work, three distinct trends of energetic can be seen: those for samples with nearly complete order, nearly complete disorder, and intermediate order. From these trends, the enthalpy of complete disordering is estimated to be 33 {+-} 6 kJ/mol for MgCa(CO{sub 3}){sub 2} and 18 {+-} 5 kJ/mol for FeCa(CO{sub 3}){sub 2}.

Brady, P.; Dooley, D.; Navrotsky, A.; Reeder, R.

1999-02-10

219

Authorize Compound Orders  

Cancer.gov

Home What's New Discovery Development Pathways Grants/Contracts Site Search Data Search NCI View Status / Authorize Orders Authorized representatives: Authorize Compound Orders If you ordered compounds from the DTP and wish to view the status of your

220

Decal Removal Compound.  

National Technical Information Service (NTIS)

The patent application pertains to a decal removal compound which loosens the adhesive which bonds the decal to an aircraft's painted surface without adversely affecting the underlying protective paint system. The compound includes three active solvents, ...

J. H. Vinson

1974-01-01

221

Photochemistry of uranium compounds  

SciTech Connect

This paper reviews the unclassified progress on the photochemistry of the following uranium compounds: UF/sub 6/, othe uranium halides, classical coordination complexes, uranium alkoxides, organometallic compounds, and uranium borohydride. Uranyl compounds are mentioned briefly. Recommendations for future studies are given. 61 references. (DLC)

Paine, R.T.; Kite, M.S.

1980-01-01

222

Compounds that inhibit cholinesterase  

US Patent & Trademark Office Database

Compounds that inhibit cholinesterase activity and, upon hydrolysis release a pharmacologically active agent. The compounds of the invention are employed in methods to treat an individual. The pharmacologically active agent obtained by hydrolysis of the compound can treat, for example, a nervous system condition, a cholinergic deficiency and conditions or diseases associated with a deficiency in a pharmacologically active agent, such as acetylcholine.

Rupniak; Nadia M. J. (Cary, NC); White; James F. (Carlisle, MA); Shiosaki; Kazumi (Wellesley, MA); Leander; J. David (Indianapolis, IN); Du; Shoucheng (Pittsburgh, PA); Coughlin; Daniel J. (Hackettstown, NJ)

2012-01-24

223

(Energies of organic compounds)  

Microsoft Academic Search

The first part of our study of the enthalpy of reduction of carbonyl compounds has been completed and includes four aldehydes, acetone, a series of cyclic ketones and ethyl acetate. The results suggest that some of the literature data for these compounds are significantly in error. Equilibrium constants have been measured for the reaction of carbonyl compounds with water to

Wiberg

1989-01-01

224

Calorimetric study of fluorinated methacrylic and vinyl polymer blends: 1. Binary systems: determination of miscibility domains and correlation of glass transition temperatures with blends composition— application to plastic optical fibre cladding  

Microsoft Academic Search

This paper reports a calorimetric study of binary polymer blends prepared by solution mixing of fluoroalkyl methacrylic ester-methyl methacrylate (MMA) copolymers with poly(vinylidene difluoride) (PVDF) or VDF-hexafluoropropene (HFP) (or VDF-trifluoroethylene) copolymers and examines their use as materials in plastic optical fibres (POF) technology. Some interesting blends were also obtained through mechanical mixing in the molten state. As compared to the

Sylvie Pimbert; Guy Levesque

1997-01-01

225

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

226

Bioavailability of Phenolic Compounds  

Microsoft Academic Search

Phenolic compounds in foods originate from one of the main classes of secondary metabolites in plants. They are essential for the growth and reproduction of plants, and are produced as a response for defending injured plants against pathogens. In recent years, there is a growing interest in phenolic compounds and their presumed role in the prevention of various degenerative diseases,

SIBEL KARAKAYA

2004-01-01

227

Analyzing Cranberry Bioactive Compounds  

Microsoft Academic Search

There is a growing public interest for the North American cranberry (Vaccinium macrocarpon) as a functional food because of the potential health benefits linked to phytochemical compounds present in the fruit—the anthocyanin pigments, responsible for its brilliant red color, and other secondary plant metabolites (flavonols, flavan-3-ols, proanthocyanidins, and phenolic acid derivatives). Isolation of these phenolic compounds and flavonoids from a

J. Côté; S. Caillet; G. Doyon; J.-F Sylvain; M. Lacroix

2010-01-01

228

Electrochemical and calorimetric investigations of some thermodynamic properties of EuCl3 and EuCl2 dissolved in alkali chloride melts  

NASA Astrophysics Data System (ADS)

The electroreduction of EuCl3 in alkali chloride melts (NaCl KCl, KCl, CsCl) was studied in the temperature range 973 1123 K by different electrochemical methods. It was determined that electrochemical reduction of Eu(III) in alkali chloride molten salts occurs via two successive reversible stages involving transfer of one and two electrons. The formal standard potentials of EEu(II)/Eu?, EEu(III)/Eu? and formal redox potentials of EEu(III)/Eu(II)? were determined from open-circuit potentiometry and linear sweep voltammetry data. The thermodynamics of formation dilute solutions of europium di-and tri-chloride in alkali chloride melts was determined. The relative partial molar enthalpies of mixing EuCl2 with alkali chloride melts when dilute solutions are formed have been measured previously by direct calorimetry in a Calvet type calorimeter using of ampoule break-off technique. It was shown that the values determined from electrochemical measurements are in a good agreement with those data obtained by calorimetric method.

Kuznetsov, S. A.; Rycerz, L.; Gaune-Escard, M.

2005-09-01

229

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

2012-02-17

230

Factors determining the formation of complexes between alpha-cyclodextrin and alkylated substances in aqueous solutions: a calorimetric study at 25 degrees C.  

PubMed

The formation of complexes of alpha-cyclodextrin with cycloalkanediols, monoalkylamines and 1-alkanols has been studied calorimetrically at 25 degrees C in water, in phosphoric acid, pH 1.3, and in phosphate buffer, pH 5.5, respectively. When a complex is formed, calorimetry enables the calculation of both the enthalpy and the association constant, from which the free energy and the entropy of the process can be obtained. A model is proposed to explain the unusual trend of the association parameters for substances having alkyl chains longer than six-seven carbon atoms. The main role played by the different functional groups, and the forces involved in the association process, are discussed in the light of the signs and values of the thermodynamic parameters obtained. The effect of the variation of the aqueous medium on the hydration of the interacting substances and the consequent changes in the association parameters have been investigated. To this end, the thermodynamic parameters for the formation of the complexes between the cyclodextrin and 1-pentanol were determined at increasing concentrations of phosphate buffer. There is an increase in the association constant due to a positive entropy contribution originating from the relaxation of water molecules from the hydrophobic hydration cosphere of the alkanol to an increasingly disordered bulk. Deaquation of the interacting substances is the main factor determining the stability of the inclusion complex. PMID:10839121

Castronuovo, G; Elia, V; Iannone, A; Niccoli, M; Velleca, F

2000-05-01

231

Refinement of non-calorimetric determination of the change in heat capacity, ?Cp, of protein unfolding and validation across a wide temperature range  

PubMed Central

The change in heat capacity, ?Cp, upon protein unfolding has been usually determined by calorimetry. A non-calorimetric method which employs the Gibbs-Helmholtz relationship to determine ?Cp has seen some use. Generally, the free energy change upon unfolding of the protein is determined at a variety of temperatures and the temperature at which ?G is zero, Tm, and change in enthalpy at Tm are determined by thermal denaturation and ?Cp is then calculated using the Gibbs-Helmholtz equation. We show here that an abbreviated method with stability determinations at just two temperatures gives values of ?Cp consistent with values from free energy change upon unfolding determination at a much wider range of temperatures. Further, even the free energy change upon unfolding from a single solvent denaturation at the proper temperature, when coupled with the melting temperature, Tm, and the van’t Hoff enthalpy, ?HvH, from a thermal denaturation, gives a reasonable estimate of ?Cp, albeit with greater uncertainty than solvent denaturations at two temperatures. We also find that non-linear regression of the Gibbs-Helmholtz equation as a function of stability and temperature while simultaneously fitting ?Cp, Tm, and ?HvH gives values for the last two parameters that are in excellent agreement with experimental values.

Singh, Deepika Talla; Stites, Wesley E.

2008-01-01

232

Edheads: The Compound Machine  

NSDL National Science Digital Library

This resource is a collection of interactive animations designed to help kids learn how forces and simple machines can work together to create the compound machine. Child-centered animated activities enhance understanding of how compound machines function and how they are differentiated from simple machines. The animations require the Flash plug-in (there is a link for this on the page). Additionally the site includes a glossary of important terms, lesson plans, a teacher's guide and information from people who professionally work with compound machines. This page is part of a larger collection of animated education resources for the elementary level.

2007-09-18

233

Organic Compounds Database  

NSDL National Science Digital Library

The Colby College Department of Chemistry offers the Organic Compounds Database, which was compiled by Harold Bell of the Virginia Polytechnic Institute. Visitors can search by the compounds melting point, boiling point, index of refraction, molecular weight, formula, absorption wavelength, mass spectral peak, chemical type, and by partial name. Once entered, results are returned with basically the same type of information that can be searched, plus any other critical information. References are provided for the close to 2500 organic compounds included in the database; yet, because the site was last modified in 1995, varying the data may be required to fully authenticate its accuracy.

Bell, Harold M.

2000-01-01

234

Superconductivity, long-range magnetic order and crystalline-electric field effects in ternary rare earth compounds  

SciTech Connect

Results of an extensive calorimetric investigation of ternary are earth compounds such as RERh/sub 4/B/sub 4/ and RE/sub 1/ /sub 2/Mo/sub 6/S/sub 8/ and related pseudoternary systems was undertaken to study the competing mechanisms o superconductivity and magnetism. Heat capacity data were collected in zero and various applied magnetic fields for LuRh/sub 4/B/sub 4/ and in zero field for YRh/sub 4/B/sub 4/. A modified Debye model as well as a molecular crystal model were employed to describe the normal state data. Various superconducting and normal state parameters were derived. Spike-shaped features superimposed on top of a broader anomaly in the heat capacity of ErRh/sub 4/B/sub 4/ and Ho/sub 1/ /sub 2/Mo/sub 6/S/sub 8/ were observed at reentrant transitions, and the effects of external magnetic fields on this reentrant transition were investigated. Pronounced discontinuities in the specific heat at the magnetic ordering temperatures were apparent for the RERh/sub 4/B/sub 4/ compounds where RE = Gd,Tb,Dy, and Ho, and the contribution of ferromagnetic transitions to the specific heats of these compounds is discussed. Phase diagrams were constructed which delineate the paramagnetic, superconductivity, magnetically ordered and normal, and magnetically ordered and superconductivity regions. Crystal field effects were also investigated for both types of compounds. (BLM)

Woolf, L.D.

1980-01-01

235

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

236

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.

Foundation, Wgbh E.

2007-02-12

237

Carcinogeniticy of Several Compounds.  

National Technical Information Service (NTIS)

The purpose of this study was to determine: A. Whether seven test compounds (Thimerosal, ethylene chlorohydrin, Methyl Paraben, Phenol Red, ethylene glycol, Benzethonium chloride and pyridine) cause malignant tumors in mice when given subcutaneously and w...

F. Homburger

1968-01-01

238

Use of Organofluorine Compounds.  

National Technical Information Service (NTIS)

Because of their thermal and chemical stability as well as their electrical and surface active properties, fluorine organic compounds are used as refrigerants, aerosol propellants and combustion suppressors. As finishing agents they confer water and oil r...

H. Muramatsu S. Nagase

1982-01-01

239

New Antimicrobial Compounds.  

National Technical Information Service (NTIS)

The present invention relates generally to antimicrobial compounds. More particularly, the present invention is related to a new class of polypeptides, designated herein 'Magainins', which have a broad range of antimicrobial activity. It is a further obje...

M. A. Zasloff

1987-01-01

240

Compound semiconductor characterization  

NASA Astrophysics Data System (ADS)

Impurities and defects in semiconducting and semi-insulating GaAs and other III-V compounds have been investigated by electrical, optical, and mass spectroscopic techniques. Field-effect transistors have been fabricated and tested.

Look, D. C.; Yu, P. W.; Nam, S. B.; Walters, D. C.; Chaudhuri, S.

1984-06-01

241

Stereochemistry of cyclic compounds  

Microsoft Academic Search

1.The adduct formed by 3,4-dihydro-6-methoxy-1-vinylnaphthalene with maleic anhydride (II), and also the corresponding acid (III) and diester (IV), has a cis-syn configuration.2.On treatment with hydrogen chloride compounds of this series are readily converted into the corresponding isomers (V), (VI), and (VII), which contain an intercycle double bond.3.A study was made of the catalytic hydrogenation of compounds of the two isomeric

V. F. Kucherov; V. M. Andreev; L. K. Lysanchuk

1960-01-01

242

Thermodynamics of organic compounds  

Microsoft Academic Search

Basic and applied research have continued on the thermodynamic properties of currently used high density\\/high energy fuels and of pure chemical compounds that may be constituents of high energy fuels of the future. Enthalpy of combustion was measured for three compounds that are constituents of current ramjet fuels--hexacyclic exo, exo-dihydrodinorbornadiene, hexacyclic endo, endo-dihydrodinorbornadiene and exo-tetrahydrodicyclopentadiene (JP-10). Heat capacities of exo-tetrahydrodicyclopentadiene

W. D. Good; R. H. P. Thomas; B. E. Gammon; S. Lee-Bechtold; J. E. Callanan; N. K. Smith

1980-01-01

243

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

244

Solid-liquid phase equilibria of binary and ternary mixtures of benzene and polynuclear aromatic compounds  

SciTech Connect

Separation of organic close-boiling or close-melting components from a mixture is a challenging task in some chemical engineering processes, such as crystallization and extraction. With the present trend in the petroleum industry toward heavier feedstocks and coal-derived liquids, there is a strong need for expansion of the small database of thermodynamic data on heavier compounds that presently exists. Solid-liquid equilibrium phase diagrams for three binary mixtures of benzene with polynuclear aromatic compounds (fluorene, dibenzofuran, and dibenzothiophene) have been measured by a dynamic method in the temperature range from 0 to 80C. These binary data plus previously published data derived from calorimetric studies were used to determine experimental activity coefficients and interaction parameters using the Wilson and UNIQUAC models. The resulting set of interaction parameters gave a good representation of the experimental binary data and ternary data at 50C, but were not generally satisfactory for predicting solid-liquid equilibrium in ternary systems at lower temperatures.

Domanska, U.; Groves, F.R. Jr.; McLaughlin, E. (Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Chemical Engineering)

1993-01-01

245

Biodegradation of nitroaromatic compounds.  

PubMed

Nitroaromatic compounds are released into the biosphere almost exclusively from anthropogenic sources. Some compounds are produced by incomplete combustion of fossil fuels; others are used as synthetic intermediates, dyes, pesticides, and explosives. Recent research revealed a number of microbial systems capable of transforming or biodegrading nitroaromatic compounds. Anaerobic bacteria can reduce the nitro group via nitroso and hydroxylamino intermediates to the corresponding amines. Isolates of Desulfovibrio spp. can use nitroaromatic compounds as their source of nitrogen. They can also reduce 2,4,6-trinitrotoluene to 2,4,6-triaminotoluene. Several strains of Clostridium can catalyze a similar reduction and also seem to be able to degrade the molecule to small aliphatic acids. Anaerobic systems have been demonstrated to destroy munitions and pesticides in soil. Fungi can extensively degrade or mineralize a variety of nitroaromatic compounds. For example, Phanerochaete chrysosporium mineralizes 2,4-dinitrotoluene and 2,4,6-trinitrotoluene and shows promise as the basis for bioremediation strategies. The anaerobic bacteria and the fungi mentioned above mostly transform nitroaromatic compounds via fortuitous reactions. In contrast, a number of nitroaromatic compounds can serve as growth substrates for aerobic bacteria. Removal or productive metabolism of nitro groups can be accomplished by four different strategies. (a) Some bacteria can reduce the aromatic ring of dinitro and trinitro compounds by the addition of a hydride ion to form a hydride-Meisenheimer complex, which subsequently rearomatizes with the elimination of nitrite. (b) Monooxygenase enzymes can add a single oxygen atom and eliminate the nitro group from nitrophenols. (c) Dioxygenase enzymes can insert two hydroxyl groups into the aromatic ring and precipitate the spontaneous elimination of the nitro group from a variety of nitroaromatic compounds. (d) Reduction of the nitro group to the corresponding hydroxylamine is the initial reaction in the productive metabolism of nitrobenzene, 4-nitrotoluene, and 4-nitrobenzoate. The hydroxylamines undergo enzyme-catalyzed rearrangements to hydroxylated compounds that are substrates for ring-fission reactions. Potential applications of the above reactions include not only the biodegradation of environmental contaminants, but also biocatalysis and synthesis of valuable organic molecules. PMID:8561470

Spain, J C

1995-01-01

246

Nonpost mold cure compound  

NASA Astrophysics Data System (ADS)

The recent low price trend of electronic products has made IC manufacturing efficiency a top priority in the semiconductor industry. Post mold cure (PMC) process, which generally involves heating the packages in the oven at 175 C for 4 to 8 hours, takes up much longer time than most other assembly processes. If this PMC process can be reduced or eliminated, semiconductor makers will be rewarded with a much higher cost merit. We define the purpose of Non-PMC as 'to get high reliability with suitable physical and electrical properties without PMC'. We compared carious properties of molding compound before and after PMC. We found that curing reaction has almost complete through DSC and C-NMR measurement, but several properties have not stabilized yet, and that not all properties after PMC were better than before PMC. We developed new grade of molding compound considering these facts. And we found that main factors to accomplish non-PMC compound are curability and flowability, and more, increasing of fundamental properties. To accomplish non-PMC, at first, molding compound need to have very high curability. Generally speaking, too high curability causes low flowability, and causes incomplete filing, wire sweep, pad shift, and weak adhesion to inner parts of IC packages. To prevent these failures, various compound properties were studied, and we achieved in adding good flowability to very high curable molding compound. Finally, anti-popcorn property was improved by adding low moisture, high adhesion, high Tg, and high flexural strengths at high temperature. Through this study, we developed new compound grade for various package, especially large QFP using standard ECN resin.

Hirata, Akihiro

1997-08-01

247

In vitro activity of gallium maltolate against Staphylococci in logarithmic, stationary, and biofilm growth phases: comparison of conventional and calorimetric susceptibility testing methods.  

PubMed

Ga(3+) is a semimetal element that competes for the iron-binding sites of transporters and enzymes. We investigated the activity of gallium maltolate (GaM), an organic gallium salt with high solubility, against laboratory and clinical strains of methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), methicillin-susceptible Staphylococcus epidermidis (MSSE), and methicillin-resistant S. epidermidis (MRSE) in logarithmic or stationary phase and in biofilms. The MICs of GaM were higher for S. aureus (375 to 2000 microg/ml) than S. epidermidis (94 to 200 microg/ml). Minimal biofilm inhibitory concentrations were 3,000 to >or=6,000 microg/ml (S. aureus) and 94 to 3,000 microg/ml (S. epidermidis). In time-kill studies, GaM exhibited a slow and dose-dependent killing, with maximal action at 24 h against S. aureus of 1.9 log(10) CFU/ml (MSSA) and 3.3 log(10) CFU/ml (MRSA) at 3x MIC and 2.9 log(10) CFU/ml (MSSE) and 4.0 log(10) CFU/ml (MRSE) against S. epidermidis at 10x MIC. In calorimetric studies, growth-related heat production was inhibited by GaM at subinhibitory concentrations; and the minimal heat inhibition concentrations were 188 to 4,500 microg/ml (MSSA), 94 to 1,500 microg/ml (MRSA), and 94 to 375 microg/ml (MSSE and MRSE), which correlated well with the MICs. Thus, calorimetry was a fast, accurate, and simple method useful for investigation of antimicrobial activity at subinhibitory concentrations. In conclusion, GaM exhibited activity against staphylococci in different growth phases, including in stationary phase and biofilms, but high concentrations were required. These data support the potential topical use of GaM, including its use for the treatment of wound infections, MRSA decolonization, and coating of implants. PMID:19805560

Baldoni, Daniela; Steinhuber, Andrea; Zimmerli, Werner; Trampuz, Andrej

2009-10-05

248

Dielectric, calorimetric and elastic anomalies associated with the first order I4/mcm \\leftrightarrow Pbcm phase transition in (Ca, Sr)TiO3 perovskites  

NASA Astrophysics Data System (ADS)

Conduction calorimetry has been used to determine with high precision the latent heat and variation in heat capacity which accompany the first order I4/mcm \\leftrightarrow Pbcm phase transition in perovskites with compositions (Ca1-xSrx)TiO3, x = 0.65, 0.68, 0.74 (CST65, CST68, CST74). In CST65 (CST68), the latent heat is dissipated/absorbed over a temperature interval of ~11 K (~6 K), which is centred on ~292 K (~258 K) during cooling and ~302 K (~270 K) during heating. The magnitude of the latent heat diminishes with increasing SrTiO3 content and was not detected in CST74. Integration of the latent heat and excess heat capacity yields small excess entropies, which are consistent with the structural changes being displacive rather than order-disorder in origin. Resonant ultrasound spectroscopy measurements on the same CST65 sample as used for dielectric and calorimetric measurements through the same temperature intervals have allowed quantitative correlations to be made with the bulk modulus, shear modulus and acoustic dissipation parameter, Q-1. The dielectric anomaly and changes in Q-1 can be understood as being linear combinations of the properties of the separate I4/mcm and Pbcm phases in proportion to their volume fractions across the two-phase field. A change of only ~0.5-1 GPa has been detected in the bulk modulus but the shear modulus softens by ~5-8 GPa as the transition interval is approached from above and below. This shear mode softening presumably reflects clustering and/or phonon softening in both the I4/mcm and Pbcm structures. This pattern of structure-property relations could be typical of first order transitions in perovskites where there is no group/subgroup relationship between the high and low symmetry phases.

Manchado, J.; Romero, F. J.; Gallardo, M. C.; del Cerro, J.; Darling, T. W.; Taylor, P. A.; Buckley, A.; Carpenter, M. A.

2009-07-01

249

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.

Sekhon, B. S.

2013-01-01

250

Lipoidal biopterin compounds  

US Patent & Trademark Office Database

The present invention provides lipoidal biopterin and tetrahydrobiopterin compounds of the general structure: ##STR1## wherein --R is absent when ring B has two double bonds, --R is hydrogen when the two double bonds in ring B are absent, and --R' and R" are selected from saturated or unsaturated, cyclic or non-cyclic hydrocarbons of 1 to 31 carbon units. The compounds provided by this invention are oil soluble and can readily be formulated as an oil based pharmaceutical useful for the treatment of phenylketonuria, Parkinsonism, depression, senile dementia, Alzheimer's disease and related biopterin deficiency diseases.

1985-10-29

251

Optimisation of compound pressure  

Microsoft Academic Search

Purpose: The purpose of this paper is optimization of the weight of compound cylinder for a specific pressure. The variables are shrinkage radius and shrinkage tolerance. Design\\/methodology\\/approach: SEQ technique for optimization, the finite element code, ANSYS for numerical simulation are employed to predict the optimized conditions. The results are verified by testing a number of closed end cylinders with various

G. H. Majzoobi; A. Ghomi

252

Biomimetic microfabricated compound eyes  

Microsoft Academic Search

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

Ki-Hun Jeong

2005-01-01

253

Copper Compounds in Plants.  

National Technical Information Service (NTIS)

A study of the distribution of copper compounds in leaves and in isolated chloroplasts of Primula obconica and Trifolium repens shows that a considerable content of them has been found in the fraction of substances soluble in chloroform and ether. The hig...

S. G. Yuferova G. N. Saenko E. A. Boichenko

1969-01-01

254

Identification of chemical compounds  

Microsoft Academic Search

We consider chemical identification as a process of setting up, testing, and screening of hypotheses, and review principles, techniques, and errors of identification. We also trace the relations between qualitative analysis and metrology and outline the range of known chemical compounds that are candidates for identification in general. We differentiate between methods for confirming identity and those for identifying unknowns,

Boris L. Milman

2005-01-01

255

Mining Chemical Compounds  

Microsoft Academic Search

In this chapter we study the problem of classifying chemical compound datasets. We present a substructure-based classification algorithm that decouples the substructure discovery process from the classification model construction and uses frequent subgraph discovery algorithms to find all topological and geometric substructures present in the dataset. The advantage of this approach is that during classification model construction, all relevant substructures

Mukund Deshpande; Michihiro Kuramochi; George Karypis

2005-01-01

256

Tagging Classical Sanskrit Compounds  

Microsoft Academic Search

The paper sets out a prima facie case for the claim that the classification of Sanskrit compounds in P??inian tradition can be retrieved from a very slight\\u000a augmentation of the usual enriched context free rules.

Brendan S. Gillon

2009-01-01

257

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

258

A compound parabolic concentrator  

SciTech Connect

A compound parabolic concentrator (CPC) for solar energy applications is presented in this work. A prototype was built and its thermal performance was determined. Operating temperatures of the order of 150 /sup 0/C with a reasonable efficiency can be attained by means of a fixed CPC.

Manrique, J.A.

1984-05-01

259

SAMPLING FOR ORGANIC COMPOUNDS  

EPA Science Inventory

The methods of sampling ambient air for organic compounds for subsequent analysis are discussed. The following methods of sample collection are presented and the advantages and disadvantages of each is given: concentration of component of interest on to solid sorbents, into liqui...

260

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

261

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

262

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

263

Magnetic Rare Earth Compounds.  

National Technical Information Service (NTIS)

A steady-state crystal growth system suitable for the growth of magnetic rare earth compounds has been designed, constructed, and successfully operated. A very stable solvent, consisting of BaO-B2O3-BaF2, has been developed. This solvent is nonvolatile an...

R. Hiskes R. A. Burmeister T. L. Felmlee

1970-01-01

264

Rhombohedral nasicon compound and battery  

SciTech Connect

Disclosed is a nasicon compound and a method of making it. The nasicon compound is rhombohedral at room temperture. The preferred compound is Na/sub 1//sub +/ /SUB x/ Zr/sub 2/Si /SUB x/ P/sub 3//sub -/ /SUB x/ O/sub 12/. A sodium sulfur battery using the nasicon compound is also disclosed.

Yoldas, B. E.; Lioyd, I. K.

1985-07-02

265

Rhombohedral nasicon compound and battery  

Microsoft Academic Search

Disclosed is a nasicon compound and a method of making it. The nasicon compound is rhombohedral at room temperture. The preferred compound is Naâ\\/sub +\\/ \\/SUB x\\/ ZrâSi \\/SUB x\\/ Pââ \\/SUB x\\/ Oââ. A sodium sulfur battery using the nasicon compound is also disclosed.

B. E. Yoldas; I. K. Lioyd

1985-01-01

266

Protonation and Complexation of Isosaccharinic Acid with U(VI) and Fe(III) in Acidic Solutions: Potentiometric and Calorimetric Studies  

SciTech Connect

Protonation and complexation of {alpha}-isosaccharinic acid with U(VI) and Fe(III) have been studied in acidic solutions at t=25 C and I=1.0 mol dm{sup -3} NaClO{sub 4}. From the potentiometric titrations, the protonation constant of the carboxylate group is calculated to be 3.65 {+-} 0.05 and the data are consistent with the presence of three and four successive mononuclear complexes for U(VI) and Fe(III), respectively. The formation constants of the complexes, log {beta}{sub j}for the reactions of M+L=ML{sub j} where j=1-3 for U(VI), j=1-4 for Fe(III) and L stands for isosaccharinate, are determined to be 2.91 {+-} 0.15 (UO{sub 2}L), 5.37 {+-} 0.07 (UO{sub 2}L{sub 2}), 7.25 {+-} 0.18 (UO{sub 2}L{sub 3}), 5.06 {+-} 0.17 (FeL), 8.51 {+-} 0.15 (FeL{sub 2}), 11.00 {+-} 0.16 (FeL{sub 3}), and 12.99 {+-} 0.17 (FeL{sub 4}). From the calorimetric titrations, the enthalpy of protonation of the carboxylate group is determined to be -(7.94 {+-} 0.03)kJ mol{sup -1}, similar to that of other ?-hydroxycarboxylates. The enthalpies of complexation between U(VI) and isosaccharinate are quite small: {Delta} H{sub 1} = -(1.0 {+-} 1.0)kJ mol{sup -1}, {Delta} H{sub 2}=1.4 {+-} 1.8 kJ mol{sup -1} and {Delta} H{sub 3}=-(6.2 {+-} 3.0)kJ mol{sup -1}, typical of the interactions between carboxylates and hard-acid cations. The complexation between U(VI) and isosaccharinate is mainly entropy-driven. In comparison, the enthalpies of complexation for FeL{sub 3} and FeL{sub 4} are large and exothermic, contributing significantly to the stability of the complexes.

Rao, Linfeng; Garnov, A Y.; Rai, Dhanpat; Xia, Yuanxian; Moore, R C.

2004-12-01

267

Non-exponential nature of calorimetric and other relaxations: Effects of 2 nm-size solutes, loss of translational diffusion, isomer specificity, and sample size  

NASA Astrophysics Data System (ADS)

Certain distributions of relaxation times can be described in terms of a non-exponential response parameter, ?, of value between 0 and 1. Both ? and the relaxation time, ?0, of a material depend upon the probe used for studying its dynamics and the value of ? is qualitatively related to the non-Arrhenius variation of viscosity and ?0. A solute adds to the diversity of an intermolecular environment and is therefore expected to reduce ?, i.e., to increase the distribution and to change ?0. We argue that the calorimetric value ?cal determined from the specific heat [Cp = T(dS/dT)p] data is a more appropriate measure of the distribution of relaxation times arising from configurational fluctuations than ? determined from other properties, and report a study of ?cal of two sets of binary mixtures, each containing a different molecule of ~2 nm size. We find that ?cal changes monotonically with the composition, i.e., solute molecules modify the nano-scale composition and may increase or decrease ?0, but do not always decrease ?cal. (Plots of ?cal against the composition do not show a minimum.) We also analyze the data from the literature, and find that (i) ?cal of an orientationally disordered crystal is less than that of its liquid, (ii) ?cal varies with the isomer's nature, and chiral centers in a molecule decrease ?cal, and (iii) ?cal decreases when a sample's thickness is decreased to the nm-scale. After examining the difference between ?cal and ? determined from other properties we discuss the consequences of our findings for theories of non-exponential response, and suggest that studies of ?cal may be more revealing of structure-freezing than studies of the non-Arrhenius behavior. On the basis of previous reports that ? --> 1 for dielectric relaxation of liquids of centiPoise viscosity observed at GHz frequencies, we argue that its molecular mechanism is the same as that of the Johari-Goldstein (JG) relaxation. Its spectrum becomes broader on cooling and its unimodal distribution reversibly changes to a bimodal distribution, each of ? < 1. Kinetic freezing of the slower modes of the bimodal distribution produces a glass. After this bifurcation, the faster, original relaxation persists as a weak JG relaxation at T --> Tg, and in the glassy state.

Johari, G. P.; Khouri, J.

2013-03-01

268

Non-exponential nature of calorimetric and other relaxations: effects of 2 nm-size solutes, loss of translational diffusion, isomer specificity, and sample size.  

PubMed

Certain distributions of relaxation times can be described in terms of a non-exponential response parameter, ?, of value between 0 and 1. Both ? and the relaxation time, ?0, of a material depend upon the probe used for studying its dynamics and the value of ? is qualitatively related to the non-Arrhenius variation of viscosity and ?0. A solute adds to the diversity of an intermolecular environment and is therefore expected to reduce ?, i.e., to increase the distribution and to change ?0. We argue that the calorimetric value ?(cal) determined from the specific heat [Cp = T(dS?dT)p] data is a more appropriate measure of the distribution of relaxation times arising from configurational fluctuations than ? determined from other properties, and report a study of ?(cal) of two sets of binary mixtures, each containing a different molecule of ?2 nm size. We find that ?(cal) changes monotonically with the composition, i.e., solute molecules modify the nano-scale composition and may increase or decrease ?0, but do not always decrease ?(cal). (Plots of ?(cal) against the composition do not show a minimum.) We also analyze the data from the literature, and find that (i) ?(cal) of an orientationally disordered crystal is less than that of its liquid, (ii) ?(cal) varies with the isomer's nature, and chiral centers in a molecule decrease ?(cal), and (iii) ?(cal) decreases when a sample's thickness is decreased to the nm-scale. After examining the difference between ?(cal) and ? determined from other properties we discuss the consequences of our findings for theories of non-exponential response, and suggest that studies of ?(cal) may be more revealing of structure-freezing than studies of the non-Arrhenius behavior. On the basis of previous reports that ? ? 1 for dielectric relaxation of liquids of centiPoise viscosity observed at GHz frequencies, we argue that its molecular mechanism is the same as that of the Johari-Goldstein (JG) relaxation. Its spectrum becomes broader on cooling and its unimodal distribution reversibly changes to a bimodal distribution, each of ? < 1. Kinetic freezing of the slower modes of the bimodal distribution produces a glass. After this bifurcation, the faster, original relaxation persists as a weak JG relaxation at T ? T(g), and in the glassy state. PMID:23556762

Johari, G P; Khouri, J

2013-03-28

269

Thermodynamics of organic compounds  

NASA Astrophysics Data System (ADS)

Basic and applied research have been continued on the thermodynamic properties of currently used high density/high energy fuels and of pure chemical compounds that may be constituents of high energy fuels of the future. Enthalpy of combustion was measured for three compounds that are constituents of current ramjet fuels--hexacyclic exo, exo-dihydrodinorbornadiene, hexacyclic endo, endo-dihydrodinorbornadiene and exo-tetrahydrodicyclocpentadiene (JP-10). Heat capacities of exo-tetrahydrodicyclopentadiene (JP-10) and RJ-6, a blend of JP-10 and the hydrogenated dimers of norbornadiene, were measured by differential scanning calorimetry. Enthalpy of combustion was measured for two pure hydrocarbons, 1,7-dimethylindan and 1,4-dimethyl-2-isobutylbenzene, that are expected to have high steric interaction energies of alkyl substituents in the ring structure, and measurements are in progress on 1-ethyl-8-methylnaphthalene and 1,6-dimethylindan.

Good, W. D.; Smith, N. K.; Thomas, R. H. P.; Gammon, B. E.; Lee-Bechtold, S.

1980-09-01

270

Biotransformation of organophosphorus compounds.  

PubMed

This study reviews current understanding of mechanisms of biotransformation of organophosphorus compounds (OPC). The first part of this article covers chemical aspects of biotransformation describing reactions that lead to activation or detoxication of OPC. The second part explains biochemical mechanisms of biotransformation describing the role of enzymes that are involved in this process. Among them are the enzymes that take part in metabolic activation of OPC such as cytochrome P450 system, NADPH-cytochrome P450 reductase and flavin-containing monooxygenases. Among enzymes participating in detoxication of OPC, the role of phosphoric triester hydrolases, carboxylesterases and glutathione redox system is explained. This article also deals with other aspects of detoxication of OPC such as protein binding and the role of tissue depots for these compounds. PMID:11543910

Jokanovi?, M

2001-09-25

271

Hydrogen in compound semiconductors  

SciTech Connect

Progress in the understanding of hydrogen and its interactions in III/V and II/VI compound semiconductors is reviewed. Donor, acceptor and deep level passivation is well established in III/V compounds based on electrical measurements and on spectroscopic studies. The hydrogen donor levels in GaAs and GaP are estimated to lie near E{sub v}+0.5 eV and E{sub v}+0.3 eV, respectively. Arsenic acceptors have been passivated by hydrogen in CdTe and the very first nitrogen-hydrogen local vibrational model spectra in ZnSe have been reported. This long awaited result may lead to an explanation for the poor activation of nitrogen acceptors in ZnSe grown by techniques which involve high concentrations of hydrogen.

Haller, E.E.

1993-05-01

272

Diphenyl Ether Antimicrobial Compounds.  

National Technical Information Service (NTIS)

The present invention is directed to compounds having the formula: wherein A(sup 1), A(sup 3), A(sup 6), and A(sup 8) independently represent CH or N; A(sup 2) represents N or C--X(sup 1)(sub a)--R(sup 1); A(sup 4) represents N or C--X(sup 2)(sub b)--R(su...

F. Johnson P. J. Tonge T. Sullivan

2005-01-01

273

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\\circ = -23.23 ± 0.04 at an ionic strength of zero determined in this work agrees well with the previously reported result, log Ksp\\circ = -23.19 ± 0.43, measured by a calorimetric experiment on UO3\\cdot2H2O(cr).

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

2008-05-01

274

Effects of a nutrient-surfactant compound on solubilization rates of TCE  

SciTech Connect

BioTreat{trademark}, a commercially available nutrient-surfactant compound, was investigated for its ability to solubilize TCE. Potential mechanisms for enhancing biodegradation rates by the use of nutrient-surfactant mixtures are: increased solubilization of TCE into the aqueous phase, and increased nutrients for the bacteria and greater numbers of colony forming units (CFUs). In aqueous systems, no measured solubilization of 0.1 and 1.0 ppm TCE from the headspace into the liquid phase was observed with BioTreat added at concentrations <0.5%. However, at BioTreat concentrations in excess of the CMC (>0.5%), increased solubilization of TCE was measured. A second question was the nutrient effect of BioTreat on the growth of the TCE-degrading bacterium, Burkholderia cepacia G4 PR1{sub 301}. The added nutrients provided by BioTreat was evident and lead to increased cell numbers. The effect of BioTreat on the expression of ortho-monooxgenase, the enzyme necessary for TCE degradation by B. cepacia was also investigated. Enzyme expression as detected by a calorimetric assay was inhibited for BioTreat concentrations >0.05%. 17 refs., 5 figs., 3 tabs.

Gillespie, M.T.; Strong-Gunderson, J.M. [Oak Ridge National Lab., TN (United States)

1997-12-31

275

Neurotoxicity of organomercurial compounds.  

PubMed

Mercury is a ubiquitous contaminant, and a range of chemical species is generated by human activity and natural environmental change. Elemental mercury and its inorganic and organic compounds have different toxic properties, but all them are considered hazardous in human exposure. In an equimolecular exposure basis, organomercurials with a short aliphatic chain are the most harmful compounds and they may cause irreversible damage to the nervous system. Methylmercury (CH(3)Hg(+)) is the most studied following the neurotoxic outbreaks identified as Minamata disease and the Iraq poisoning. The first description of the CNS pathology dates from 1954. Since then, the clinical neurology, the neuropathology and the mechanisms of neurotoxicity of organomercurials have been widely studied. The high thiol reactivity of CH(3)Hg(+), as well as all mercury compounds, has been suggested to be the basis of their harmful biological effects. However, there is clear selectivity of CH(3)Hg(+) for specific cell types and brain structures, which is not yet fully understood. The main mechanisms involved are inhibition of protein synthesis, microtubule disruption, increase of intracellular Ca(2+) with disturbance of neurotransmitter function, oxidative stress and triggering of excitotoxicity mechanisms. The effects are more damaging during CNS development, leading to alterations of the structure and functionality of the nervous system. The major source of CH(3)Hg(+) exposure is the consumption of fish and, therefore, its intake is practically unavoidable. The present concern is on the study of the effects of low level exposure to CH(3)Hg(+) on human neurodevelopment, with a view to establishing a safe daily intake. Recommendations are 0.4 micro g/kg body weight/day by the WHO and US FDA and, recently, 0.1 micro g/kg body weight/day by the US EPA. Unfortunately, these levels are easily attained with few meals of fish per week, depending on the source of the fish and its position in the food chain. PMID:12835120

Sanfeliu, Coral; Sebastià, Jordi; Cristòfol, Rosa; Rodríguez-Farré, Eduard

2003-01-01

276

Toxicology of alkylmercury compounds.  

PubMed

Methylmercury is a global pollutant and potent neurotoxin whose abundance in the food chain mandates additional studies on the consequences and mechanisms of its toxicity to the central nervous system. Formulation of our new hypotheses was predicated on our appreciation for (a) the remarkable affinity of mercurials for the anionic form of sulfhydryl (-SH) groups, and (b) the essential role of thiols in protein biochemistry. The present chapter addresses pathways to human exposure of various mercury compounds, highlighting their neurotoxicity and potential involvement in neurotoxic injury and neurodegenerative changes, both in the developing and senescent brain. Mechanisms that trigger these effects are discussed in detail. PMID:20877814

Aschner, Michael; Onishchenko, Natalia; Ceccatelli, Sandra

2010-01-30

277

Thermal latent coordination compounds  

Microsoft Academic Search

The thermal behaviour of complexes of the type M(HIm)2ac2 (HIm=imidazole,ac=acetate,M=Co, Ni, Cu) is different. Comparable to the thermal degradation of Ni(acac)2(HIm)2 [10] the Ni(HIm)2ac2 loss acetic acid by formation of Ni(Im)2. All nitrogen ligands are splitt off from the copper complex by formation of stable basic copper acetate. The cobalt compound\\u000a eliminated acetic acid partially while acetate and imidazolate bridging

M. Döring; W. Ludwig; H. Görls

1994-01-01

278

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

279

Synthesis of Catenated Polynitrogen Compounds.  

National Technical Information Service (NTIS)

Presentation includes overview of synthesis of novel compounds consisting of highly endothermic polynitrogen allotropes; use techniques developed in synthesis of other energetic materials to pursue catenated rather than polycyclic polynitrogen compounds; ...

K. O. Christe W. W. Wilson J. A. Boatz J. A. Sheehy

1999-01-01

280

Organic Compounds in Carbonaceous Meteorites.  

National Technical Information Service (NTIS)

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 bes...

G. Cooper

2001-01-01

281

Organometallic chemistry of bimetallic compounds  

SciTech Connect

This report consists of six sections: heterobimetallic dihydrides, early-late transition metal heterobimetallic compounds, amphiphilic carbene complexes and hydroxycarbene complexes, diiron compounds with bridging hydrocarbon ligands, diphosphine chelates with natural bite angles near 120 degrees, and synthesis and reactions of M=M compounds. (WET)

Casey, C.P.

1991-07-01

282

Potential risks of pharmacy compounding.  

PubMed

Pharmacy compounding involves the preparation of customized medications that are not commercially available for individual patients with specialized medical needs. Traditional pharmacy compounding is appropriate when done on a small scale by pharmacists who prepare the medication based on an individual prescription. However, the regulatory oversight of pharmacy compounding is significantly less rigorous than that required for Food and Drug Administration (FDA)-approved drugs; as such, compounded drugs may pose additional risks to patients. FDA-approved drugs are made and tested in accordance with good manufacturing practice regulations (GMPs), which are federal statutes that govern the production and testing of pharmaceutical products. In contrast, compounded drugs are exempt from GMPs, and testing to assess product quality is inconsistent. Unlike FDA-approved drugs, pharmacy-compounded products are not clinically evaluated for safety or efficacy. In addition, compounded preparations do not have standard product labeling or prescribing information with instructions for safe use. Compounding pharmacies are not required to report adverse events to the FDA, which is mandatory for manufacturers of FDA-regulated medications. Some pharmacies engage in activities that extend beyond the boundaries of traditional pharmacy compounding, such as large-scale production of compounded medications without individual patient prescriptions, compounding drugs that have not been approved for use in the US, and creating copies of FDA-approved drugs. Compounding drugs in the absence of GMPs increases the potential for preparation errors. When compounding is performed on a large scale, such errors may adversely affect many patients. Published reports of independent testing by the FDA, state agencies, and others consistently show that compounded drugs fail to meet specifications at a considerably higher rate than FDA-approved drugs. Compounded sterile preparations pose the additional risk of microbial contamination to patients. In the last 11 years, three separate meningitis outbreaks have been traced to purportedly 'sterile' steroid injections contaminated with fungus or bacteria, which were made by compounding pharmacies. The most recent 2012 outbreak has resulted in intense scrutiny of pharmacy compounding practices and increased recognition of the need to ensure that compounding is limited to appropriate circumstances. Patients and healthcare practitioners need to be aware that compounded drugs are not the same as generic drugs, which are approved by the FDA. The risk-benefit ratio of using traditionally compounded medicines is favorable for patients who require specialized medications that are not commercially available, as they would otherwise not have access to suitable treatment. However, if an FDA-approved drug is commercially available, the use of an unapproved compounded drug confers additional risk with no commensurate benefit. PMID:23526368

Gudeman, Jennifer; Jozwiakowski, Michael; Chollet, John; Randell, Michael

2013-03-01

283

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

284

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.

Senese, Frederick A.

285

TSTA compound cryopump  

SciTech Connect

The Tritium System Test Assembly (TSTA), at the Los Alamos Scientific Laboratory, is intended to demonstrate realistic fuel supply and cleanup scenarios for future fusion reactors. The vacuum pumps must be capable of handling large quantities of reactor exhaust gases consisting largely of mixtures of hydrogen and helium isotopes. Cryocondensing pumps will not pump helium at 4.2 K; while cryosorption pumps using molecular sieves or charcoal have good helium pumping speed, the adsorbent clogs with condensed hydrogen while pumping mixtures of both. A solution to this problem is a compound design whereby the first stage condenses the hydrogen species and the second, or sorption, stage pumps the helium. The TSTA pump designed at Lawrence Livermore National Laboratory uses argon gas to cryotrap the helium in the helium--hydrogen mixture. The argon is sprayed directly onto the 4.2 K surface at a rate proportional to the helium flow rate, permitting continuous pumping of the helium--hydrogen mixtures in a single-stage pump. However, the possibility of differential desorption as a first stage in the TSTA gas separation cycle required the inclusion of a first-state hydrogen isotope condenser. The design, performance, and operating characteristics are discussed.

Batzer, T.H.; Patrick, R.E.; Call, W.R.

1981-04-01

286

Nitro musk compounds genotoxic activity  

Microsoft Academic Search

s  Five nitro musk compounds are widely used as fragrance ingredients in perfumes, lotions and detergents; as food additives\\u000a in cigarettes and fish baits, and in such technical products as herbicide formulations and explosives. Several studies identified\\u000a nitro musk compounds in aquatic environment samples, human milk and fat samples as highly lipophilic and persistent bioaccumulating\\u000a environmental pollutants. To examine the compounds

Sebastian Kevekordes; Kathrin Grahl; Antonia Zaulig; Hartmut Dunkelberg

1996-01-01

287

Method of preparing metallocene compounds  

SciTech Connect

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

288

Method of preparing metallocene compounds  

SciTech Connect

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. 2 figs.

Rosenblum, M.; Matchett, S.A.

1992-06-23

289

Sesquiterpene compounds from Inula viscosa.  

PubMed

Two new compounds, 2,5-dihydroxyisocostic acid and 2,3-dihydroxycostic acid together with three known sesquiterpene compounds, Isocostic acid, Carabrone and Tomentosin, have been isolated from the acetone extract of Inula viscosa (L.) Aiton. The structures of all new compounds were determined by spectroscopic methods, in particular 1D and 2D (1)H- and (13)C-NMR. The (13)C-NMR spectra of Isocostic acid and of Tomentosin are reported here for the first time. PMID:17654288

Fontana, Gianfranco; La Rocca, Salvatore; Passannanti, Salvatore; Paternostro, Maria Pia

2007-07-20

290

Sesquiterpene compounds from Inula viscosa  

Microsoft Academic Search

Two new compounds, 2,5-dihydroxyisocostic acid and 2,3-dihydroxycostic acid together with three known sesquiterpene compounds, Isocostic acid, Carabrone and Tomentosin, have been isolated from the acetone extract of Inula viscosa (L.) Aiton. The structures of all new compounds were determined by spectroscopic methods, in particular 1D and 2D H- and C-NMR. The C-NMR spectra of Isocostic acid and of Tomentosin are

Gianfranco Fontana; Salvatore La Rocca; Salvatore Passannanti; Maria Pia Paternostro

2007-01-01

291

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

292

Indole Compounds Useful as Serotonin Selective Agents.  

National Technical Information Service (NTIS)

Novel indole compounds are disclosed. Also disclosed are methods for using the compounds to treat human and animal disease, pharmaceutical compositions of the compounds, and kits including the compounds.

B. Roth C. Morency G. Kumaran H. P. Sard L. Shuster

2005-01-01

293

Calorimetric and computational thermochemical study of 3,3-tetramethyleneglutaric acid, 3,3-tetramethyleneglutaric anhydride, and 3,3-tetramethyleneglutarimide.  

PubMed

The standard (p(o) = 0.1 MPa) molar energies of combustion in oxygen, at T = 298.15 K, of solid 3,3-tetramethyleneglutaric acid and the related 3,3-tetramethyleneglutaric anhydride and 3,3-tetramethyleneglutarimide were measured by static bomb combustion calorimetry. The values of the standard molar enthalpies of sublimation, at T = 298.15 K, were obtained by Calvet microcalorimetry, allowing the calculation of the standard molar enthalpies of formation of the compounds, in the gaseous state, at T = 298.15 K. The geometries of the experimentally studied compounds were fully optimized using density functional theory with the B3LYP functional and extended basis sets. More accurate energies were also obtained from single-point calculations at the most stable B3LYP/6-311G** geometries, using the cc-pVTZ basis set. From these calculations the standard molar enthalpies of formation of 3,3-tetramethyleneglutaric acid, 3,3-tetramethyleneglutaric anhydride, and 3,3-tetramethyleneglutarimide were estimated using isodesmic reactions involving glutaric acid, glutaric anhydride, and glutarimide, respectively. Experimental and computational results were used in the discussion of the interrelation of energetics and structure in these compounds and compared with other structurally related compounds. PMID:18774787

Matos, M Agostinha R; Miranda, Margarida S; Fonseca, Diana A P; Morais, Victor M F; Liebman, Joel F

2008-09-06

294

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

295

Preparation of Radioactive Labelled Compounds.  

National Technical Information Service (NTIS)

Production and control of labelled compounds were carried out at KAERI to meet the domestic demands. Two hundred mCi sup 131 OI compounds, 4800 sup 99 mOTc labelling vials, and 450 T3-, T4-radioimmunoassay kits were produced, respectively, resulting in th...

J. R. Kim K. H. Han U. W. Park H. S. Shim

1985-01-01

296

Macrocyclic Compounds as Corrosion Inhibitors  

Microsoft Academic Search

The influence of three macrocyclic compounds on corrosion of mild steel (MS) in hydrochloric acid (HCl) was investigated using weight loss, potentiodynamic polarization, alternating current (AC) impedance, and hydrogen permeation techniques. All the investigated compounds showed significant efficiencies and reduced permeation of hydrogen through MS in HCl. Inhibition efficiency (IE) varied with the nature and concentrations of the inhibitors, temperature,

M. A. Quraishi; J. A. Rawat; M. A. Ajmal

1998-01-01

297

Biologically Inspired Artificial Compound Eyes  

Microsoft Academic Search

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

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

2006-01-01

298

Anodic synthesis of heterocyclic compounds  

Microsoft Academic Search

This article discusses the anodic synthesis of heterocyclic compounds that have appeared during the last decade. The mechanistic aspects involving intramolecular, intermolecular cyclizations and the homogeneous vs heterogeneous anodic oxidations were considered. This review deals with the recent advances in anodic oxidations in which heterocyclic compounds were synthesized through carbon-heteroatom and heteroatom-heteroatom bond formation.

Ibro Tabakovi?

299

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…

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

2008-01-01

300

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

301

Assimilation of Unusual Carbon Compounds  

NASA Astrophysics Data System (ADS)

Yeast taxa traditionally are distinguished by growth tests on several sugars and organic acids. During the last decades it became apparent that many yeast species assimilate a much greater variety of naturally occurring carbon compounds as sole source of carbon and energy. These abilities are indicative of a greater role of yeasts in the carbon cycle than previously assumed. Especially in acidic soils and other habitats, yeasts may play a role in the degradation of carbon compounds. Such compounds include purines like uric acid and adenine, aliphatic amines, diamines and hydroxyamines, phenolics and other benzene compounds and polysaccharides. Assimilation of purines and amines is a feature of many ascomycetes and basidiomycetes. However, benzene compounds are degraded by only a few ascomycetous yeasts (e.g. the Stephanoascus/ Blastobotrys clade and black yeastlike fungi) but by many basidiomycetes, e.g. Filobasidiales, Trichosporonales, red yeasts producing ballistoconidia and related species, but not by Tremellales. Assimilation of polysaccharides is wide-spread among basidiomycetes

Middelhoven, Wouter J.

302

Macrocyclic compounds as corrosion inhibitors  

SciTech Connect

The influence of three macrocyclic compounds on corrosion of mild steel (MS) in hydrochloric acid (HCl) was investigated using weight loss, potentiodynamic polarization, alternating current (AC) impedance, and hydrogen permeation techniques. All the investigated compounds showed significant efficiencies and reduced permeation of hydrogen through MS in HCl. Inhibition efficiency (IE) varied with the nature and concentrations of the inhibitors, temperature, and concentrations of the acid solutions. The addition of iodide ions (I{sup {minus}}) increased IE of all the tested compounds as a result of the synergistic effect. Potentiodynamic polarization results revealed that macrocyclic compounds acted as mixed inhibitors in 1 M HCl to 5 M HCl. Adsorption on the metal surface obeyed Temkin`s adsorption isotherm. Auger electron spectroscopy (AES) of the polished MS surface, exposed with tetraphenyldithia-octaazacyclotetradeca-hexaene (PTAT) proved adsorption of this compound on the surface through nitrogen and sulfur atoms.

Quraishi, M.A.; Rawat, J.; Ajmal, M. [Aligarh Muslim Univ., Uttar Pradesh (India)

1998-12-01

303

Indium Fluoroalkoxide Compounds.  

PubMed

Reactions of indium amide complexes with fluorinated alcohols give indium fluoroalkoxide complexes. In[N-t-Bu(SiMe(3))](3) reacts with 3 equiv of (CF(3))Me(2)COH to give the homoleptic alkoxide dimer [In{&mgr;-OCMe(2)(CF(3))}{OCMe(2)(CF(3))}(2)](2), but reactions involving the more acidic alcohols (CF(3))(2)MeCOH and (CF(3))(2)CHOH yield products containing t-BuNH(2), which is derived from the amide ligands. Thus, In[N-t-Bu(SiMe(3))](3) reacts with (CF(3))(2)MeCOH to give In[OCMe(CF(3))(2)](3)(H(2)N-t-Bu) and with (CF(3))(2)CHOH to yield In[OCH(CF(3))(2)](3)(H(2)N-t-Bu)(3) and [H(3)N-t-Bu][In{OCH(CF(3))(2)}(4)(H(2)N-t-Bu)]. Reactions of (CF(3))(2)MeCOH and (CF(3))(2)CHOH with In(tmp)(3) (tmp = the anion derived from 2,2,6,6-tetramethylpiperidine) and In(NEt(2))(3) are less complicated. In(tmp)(3) reacts with 3 equiv of (CF(3))(2)CHOH to give In[OCH(CF(3))(2)](3)(Htmp) and with 4 equiv of (CF(3))(2)CHOH or (CF(3))(2)MeCOH to yield the salt compounds [H(2)tmp][In{OCR(CF(3))(2)}(4)] (R = H, Me). Trigonal bipyramidal [H(2)NEt(2)][In{OCH(CF(3))(2)}(4)(HNEt(2))] and octahedral mer-In[OCMe(CF(3))(2)](3)(py)(3) are isolated from reactions involving In(NEt(2))(3). Crystal structure determinations of [In{&mgr;-OCMe(2)(CF(3))}{OCMe(2)(CF(3))}(2)](2), [H(3)N-t-Bu][In{OCH(CF(3))(2)}(4)(H(2)N-t-Bu)].EtOEt, In[OCH(CF(3))(2)](3)(Htmp), [H(2)tmp][In{OCMe(CF(3))(2)}(4)], In[OCMe(CF(3))(2)](3)(py)(3), and [H(2)NEt(2)][In{OCH(CF(3))(2)}(4)(HNEt(2))] were carried out. PMID:11671155

Mîinea, Liliana A.; Suh, Seigi; Hoffman, David M.

1999-10-01

304

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

305

Process for removing sulfur compounds  

SciTech Connect

A process for removing sulfur compounds including at least hydrogen sulfide and sulfur dioxide from a sulfur contaminated fluid stream having a concentration of said sulfur compounds is described comprising the step of: contacting said sulfur contaminated fluid stream with an absorption composition comprising: zinc oxide in an amount between about 60 and about 90 weight percent; zinc phosphate in an amount between about 10 and about 40 weight percent; and alumina in an amount up to about 30 weight percent to produce a treated effluent stream having a substantially reduced concentration of said sulfur compounds.

Lowery, R.E.; Engelbert, D.R.

1993-06-15

306

The Chemiluminescence of Organometallic Compounds  

NASA Astrophysics Data System (ADS)

Studies on the liquid-phase and gas-phase reactions of organometallic compounds accompanied by the emission of light are described systematically and discussed. The influence of the magnetic field on the chemiluminescence of Grignard reagents and the study of the electrochemiluminescence of solutions of organometallic compounds are examined. The ways leading to further development of the field of the chemiluminescence of organometallic compounds and certain possible applications of the phenomenon in the monitoring of industrial processes are discussed. The bibliography includes 80 references.

Tolstikov, Genrikh A.; Bulgakov, Ramil G.; Kazakov, Valeri P.

1985-11-01

307

Polishing compound for plastic surfaces  

DOEpatents

A polishing compound for plastic surfaces is disclosed. The compound contains by weight approximately 4 to 17 parts at least one petroleum distillate lubricant, 1 to 6 parts mineral spirits, 2.5 to 15 parts abrasive particles, and 2.5 to 10 parts water. The abrasive is tripoli or a similar material that contains fine particles silica. Preferably, most of the abrasive particles are less than approximately 10 microns, more preferably less than approximately 5 microns in size. The compound is used on PLEXIGLAS{trademark}, LEXAN{trademark}, LUCITE{trademark}, polyvinyl chloride (PVC) and similar plastic materials whenever a smooth, clear polished surface is desired. 5 figs.

Stowell, M.S.

1995-08-22

308

Polishing compound for plastic surfaces  

DOEpatents

A polishing compound for plastic surfaces is disclosed. The compound contains by weight approximately 4 to 17 parts at least one petroleum distillate lubricant, 1 to 6 parts mineral spirits, 2.5 to 15 parts abrasive particles, and 2.5 to 10 parts water. The abrasive is tripoli or a similar material that contains colloidal silica. Preferably, most of the abrasive particles are less than approximately 10 microns, more preferably less than approximately 5 microns in size. The compound is used on PLEXIGLAS{sup TM}, LEXAN{sup TM}, LUCITE{sup TM}, polyvinyl chloride (PVC) and similar plastic materials whenever a smooth, clear polished surface is desired.

Stowell, M.S.

1993-01-01

309

Polishing compound for plastic surfaces  

DOEpatents

A polishing compound for plastic surfaces. The compound contains by weight approximately 4 to 17 parts at least one petroleum distillate lubricant, 1 to 6 parts mineral spirits, 2.5 to 15 parts abrasive particles, and 2.5 to 10 parts water. The abrasive is tripoli or a similar material that contains fine particles silica. Preferably, most of the abrasive particles are less than approximately 10 microns, more preferably less than approximately 5 microns in size. The compound is used on PLEXIGLAS.TM., LEXAN.TM., LUCITE.TM., polyvinyl chloride (PVC) and similar plastic materials whenever a smooth, clear polished surface is desired.

Stowell, Michael S. (New Ellenton, SC)

1995-01-01

310

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

311

Prebiotic Evolution of Nitrogen Compounds.  

National Technical Information Service (NTIS)

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, i...

G. Arrhenius

1999-01-01

312

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

313

Fourth Symposium on Macrocyclic Compounds.  

National Technical Information Service (NTIS)

Both theoretical and experimental aspects of the properties and behavior of synthetic and naturally occurring macrocyclic compounds are covered in this symposium. This document contains abstracts of the papers. (ERA citation 06:017177)

J. J. Christensen R. M. Izatt

1980-01-01

314

[Compounds from Caesalpinia sappan L].  

PubMed

Two compounds were isolated from the stem of Caesalpinia sappan. Their structures were elucidated on the basis of physical and spectral analysis. They were named as tetraacetylbrazilin and protosappanin A respectively. PMID:7980861

Xu, H; Zhou, Z H; Yang, J S

1994-08-01

315

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

316

Polishing compound for plastic surfaces  

DOEpatents

This invention is comprised of a polishing compound for plastic materials. The compound includes approximately by approximately by weight 25 to 80 parts at least one petroleum distillate lubricant, 1 to 12 parts mineral spirits, 50 to 155 parts abrasive paste, and 15 to 60 parts water. Preferably, the compound includes approximately 37 to 42 parts at least one petroleum distillate lubricant, up to 8 parts mineral spirits, 95 to 110 parts abrasive paste, and 50 to 55 parts water. The proportions of the ingredients are varied in accordance with the particular application. The compound is used on PLEXIGLAS{trademark}, LEXAN{trademark}, LUCITE{trademark}, polyvinyl chloride (PVC), and similar plastic materials whenever a smooth, clear polished surface is desired.

Stowell, M.S.

1991-01-01

317

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

318

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.

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

1998-01-06

319

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

320

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.

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

2012-01-01

321

Antiplasmodial compounds from Cochlospermum tinctorium.  

PubMed

Fractionation of an ethanol extract of roots of Cochlospermum tinctorium afforded five compounds: 3-O-E-p-coumaroylalphitolic acid (1), cochloxanthin (2), dihydrocochloxanthin (3), alphitolic acid (4), and 1-hydroxytetradecan-3-one (5). This is the first example of a 1-hydroxyalkan-3-one obtained from plant material after gentle workup. The antiplasmodial activities of the compounds were determined, and the IC(50) value of 3-O-E-p-coumaroylalphitolic acid was 2.3 microM. PMID:12350157

Ballin, Nicolai Zederkopff; Traore, Maminata; Tinto, Halidou; Sittie, Archibald; Mølgaard, Per; Olsen, Carl Erik; Kharazmi, Arsalan; Christensen, Søren Brøgger

2002-09-01

322

Magnetic properties and magnetocaloric effect in Ho{sub 6-x}Er{sub x}MnBi{sub 2} compounds  

SciTech Connect

Magnetic properties and magnetocaloric effect of compounds Ho{sub 6-x}Er{sub x}MnBi{sub 2} (x=0,3,6) are investigated experimentally. All the compounds crystallize in the hexagonal Zr{sub 6}CoAs{sub 2}-type structure and show a sharp drop in the magnetization around their respective magnetic ordering temperature, which is 201 K (x=0), 147 K (x=3), and 98 K (x=6), respectively. Either thermal or magnetic hysteresis around the phase transition is not observed, suggesting a second order phase transition nature. The magnetic entropy change ({Delta}S{sub m}) calculated from the Maxwell relation using the collected magnetization data is 10.6 (x=6), 7.3 (x=3), and 5.0 J kg{sup -1} K{sup -1} (x=0), respectively. The shape of the {Delta}S{sub m}-T curve has a good symmetry below and above the magnetic ordering temperature, and the value of the magnetic entropy change increases monotonously with increasing field change. The calorimetric technique has also been used for Er{sub 6}MnBi{sub 2} to check the credibility of the magnetic method.

Wang Fang; Yuan Fengying; Cao Yang; Gao Chunjing; Hao Yanming [Tian Jin University of Science and Technology, Tian Jin 300222 (China); Zhang Jian [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130 (China); Shen Jun [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Sun Jirong; Shen Baogen [State Key Laboratory of Magnetism, Institute of Physics, and Centre for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190 (China)

2010-05-15

323

Magnetic entropy change and relative cooling power of Gd3Ni6Al2 and Tb3Ni6Al2 compounds  

NASA Astrophysics Data System (ADS)

We present study of the magnetocaloric effects (MCE) in Gd3Ni6Al2 and Tb3Ni6Al2 crystallizing in the Cubic Ce3Ni6Si3-type structure. The two compounds undergo a second-order ferromagnetic transition at Curie temperature TC=105.7 and 57.5 K for Gd3Ni6Al2 and Tb3Ni6Al2, respectively. Magnetization and specific heat are measured as functions of temperature and magnetic field around TC, and the measurements are used to estimate the magnetic entropy change (?Sm) and the relative cooling power (RCP) by both magnetic and calorimetric techniques. A relatively large ?Sm associated with the ferromagnetic transition has been observed over a wide temperature range for both the compounds, leading to a high RCP. The maximum values of ?Sm in a 5 T magnetic field are evaluated to be 6.2 Jkg-1K-1 for Gd3Ni6Al2 and 9.8 Jkg-1K-1 for Tb3Ni6Al2, the corresponding values of RCP are 608 and 461 Jkg-1, respectively. Particularly, both Gd3Ni6Al2 and Tb3Ni6Al2 show higher RCP values even in a small field change that can be generated by a permanent magnet.

Li, D. X.; Nimori, S.; Aoki, D.

2013-03-01

324

Compounds with High Monoamine Transporter Affinity.  

National Technical Information Service (NTIS)

Featured compounds have high monoamine transport affinity and are characterized by one of the following two general formulas set out above. The compounds bind selectively or non-selectively to monoamine transporters. The compounds are useful to treat vari...

B. K. Madras P. Blundell P. Wang P. C. Meltzer

2005-01-01

325

Diazo compounds in the chemistry of fullerenes  

NASA Astrophysics Data System (ADS)

Experimental and theoretical data on the reactions of different diazo compounds (diazomethane, its derivatives, cyclic diazo compounds and diazocarbonyl compounds) with fullerenes are summarized. The structures and stereochemistry of cycloadducts formed in these reactions are considered.

Tuktarov, Airat R.; Dzhemilev, Usein M.

2010-09-01

326

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.

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

327

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.

Olano, Carlos; Mendez, Carmen; Salas, Jose A.

2009-01-01

328

Antimutagenic effects of polyphenolic compounds.  

PubMed

Smokers expose themselves to potent carcinogens daily. One of them is the nicotine-derived nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). Since estimates are that humans consume 1 g of phenolic compounds/day, we investigated the inhibitory effects of five structurally related polyphenolic compounds on the mutagenicity of NNK in Salmonella typhimurium TA1535. NNK at a concentration of 80 mM was activated by hamster liver microsomes. The antimutagenic efficacies were dose-related between the non-toxic concentrations of 0.1 and 0.5 mmol/dish in the following order: esculetin > ellagic acid > (+)-catechin > propyl gallate > (-)esculin. At the highest non-toxic dose tested (0.5 mmol/dish), these polyphenolics inhibited mutagenesis in TA1535 by 77%, 67%, 62%, 59% and 53%, respectively. The results of this study demonstrated that polyphenolic compounds may inhibit the activation of NNK. PMID:1394114

Teel, R W; Castonguay, A

1992-09-30

329

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.

Chitambar, Christopher R

2013-01-01

330

Biodegradation of halogenated organic compounds.  

PubMed

In this review we discuss the degradation of chlorinated hydrocarbons by microorganisms, emphasizing the physiological, biochemical, and genetic basis of the biodegradation of aliphatic, aromatic, and polycyclic compounds. Many environmentally important xenobiotics are halogenated, especially chlorinated. These compounds are manufactured and used as pesticides, plasticizers, paint and printing-ink components, adhesives, flame retardants, hydraulic and heat transfer fluids, refrigerants, solvents, additives for cutting oils, and textile auxiliaries. The hazardous chemicals enter the environment through production, commercial application, and waste. As a result of bioaccumulation in the food chain and groundwater contamination, they pose public health problems because many of them are toxic, mutagenic, or carcinogenic. Although synthetic chemicals are usually recalcitrant to biodegradation, microorganisms have evolved an extensive range of enzymes, pathways, and control mechanisms that are responsible for catabolism of a wide variety of such compounds. Thus, such biological degradation can be exploited to alleviate environmental pollution problems. The pathways by which a given compound is degraded are determined by the physical, chemical, and microbiological aspects of a particular environment. By understanding the genetic basis of catabolism of xenobiotics, it is possible to improve the efficacy of naturally occurring microorganisms or construct new microorganisms capable of degrading pollutants in soil and aquatic environments more efficiently. Recently a number of genes whose enzyme products have a broader substrate specificity for the degradation of aromatic compounds have been cloned and attempts have been made to construct gene cassettes or synthetic operons comprising these degradative genes. Such gene cassettes or operons can be transferred into suitable microbial hosts for extending and custom designing the pathways for rapid degradation of recalcitrant compounds. Recent developments in designing recombinant microorganisms and hybrid metabolic pathways are discussed. PMID:2030673

Chaudhry, G R; Chapalamadugu, S

1991-03-01

331

Process challenges in compound semiconductors  

NASA Astrophysics Data System (ADS)

Compound semiconductors, such as GaAs, InP, and HgCdTe, are essential components in future photonics and microelectronics technologies. If the United States is to be competitive in these technologies, attention must be directed to the reproducible and affordable processing of these materials. This report assesses the current status of compound semiconductor processing technology and identifies factors that limit the ability to fabricate advanced electronic and optoelectronic devices. Emphasis is placed on current and near-term devices, but the process technologies discussed are generic to future components and systems based on these materials.

1988-08-01

332

Quorum-Sensing Inhibitory Compounds  

Microsoft Academic Search

\\u000a Biofilm\\u000a formation plays an important role in antimicrobial resistance, posing\\u000a a global threat to the economy and public health. Hence, discovery of\\u000a novel antagonists is critical. In this chapter, we introduce a class of\\u000a compounds, brominated furanones, which have a broad spectrum of\\u000a activities against bacterial multicellular behaviors, such as biofilm\\u000a formation and quorum sensing. The application of these compounds and the\\u000a mechanisms

Dacheng Ren; Michael Givskov; Thomas Bovbjerg Rasmussen; Naomi Balaban

333

Electronic Configuration of Yb Compounds  

SciTech Connect

The total energy differences between divalent and trivalent configurations of Yb ions in a number of Yb compounds are studied. Two different band theoretical methods, which differ in the treatment of the localized f electrons, are used. The results show that in all Yb compounds the valence energy differences are equal to the energy needed to localize an f electron. These valence energy differences correlate with the number of f electrons hybridizing with the conduction bands in the trivalent configuration. For divalent YbS, the pressure induced f -electron delocalization implies an intermediate valency, as also indicated by experiment. {copyright} {ital 1999} {ital The American Physical Society }

Temmerman, W.M.; Szotek, Z. [Daresbury Laboratory, Daresbury, Warrington, WA4 4AD, Cheshire (United Kingdom); Svane, A. [Institute of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Strange, P. [Physics Department, Keele University, Keele, Staffordshire, ST5 5BG (United Kingdom); Winter, H. [INFP, Forschungszentrum Karlsruhe GmbH, Postfach 3640, D-76021 Karlsruhe (Germany); Delin, A.; Johansson, B.; Eriksson, O.; Fast, L. [Condensed Matter Theory Group, Department of Physics, University of Uppsala, Box 530, 75121 Uppsala (Sweden); Wills, J.M. [Center of Materials Science and Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States)

1999-11-01

334

Atmospheric Freons and Halogenated Compounds.  

National Technical Information Service (NTIS)

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 reacti...

A. Appleby

1976-01-01

335

Stereoselective synthesis of coordination compounds  

Microsoft Academic Search

After an introduction, where the general aspects of stereoselective synthesis of coordination species are shortly reviewed, an account of the use of pyridine and bipyridine ligands that are made chiral through incorporation of structural elements taken from terpenes, which occur naturally as enantiopure or at least non-racemic compounds, is given. It is shown that this ligand family, which presently comprises

Alex von Zelewsky

1999-01-01

336

A tale of two compounds  

NASA Astrophysics Data System (ADS)

Two constitutional isomers with exceptionally similar structures have had very different impacts in chemistry and beyond. With this example, Bruce Gibb highlights just how difficult it is to predict how much a particular compound or piece of chemical research will contribute to society, especially in the short term.

Gibb, Bruce C.

2011-10-01

337

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

338

Infrared Spectroscopy of Deuterated Compounds.  

ERIC Educational Resources Information Center

|Background information, procedures used, and typical results obtained are provided for an experiment (based on the potassium bromide pressed-pellet method) involving the infrared spectroscopy of deuterated compounds. Deuteration refers to deuterium-hydrogen exchange at active hydrogen sites in the molecule. (JN)|

MacCarthy, Patrick

1985-01-01

339

Polyhdroxylated Benzene-Containing Compounds.  

National Technical Information Service (NTIS)

A method for reducing food intake in a subject and a method for reducing the levels of an endocrine in a subject. The methods include administering to the subject in need thereof an effective amount of a compound of the formula: Also disclosed is a liposo...

R. A. Hiipakka S. Liao Y. H. Kao

2003-01-01

340

Fluorescence Yields of Aromatic Compounds.  

National Technical Information Service (NTIS)

Values of fluorescence yields for eighteen compounds in solution at 23C are reported and are compared to previous literature values. Modifications of the technique of Weber and Teale for measurement of fluorescence yields are described. Fluorescein in 0.1...

W. R. Dawson M. W. Windsor

1968-01-01

341

Compound Interest in International Disputes  

Microsoft Academic Search

In today's economic world, compound interest, and not simple interest, is the norm in both third-party financing and investment vehicles. Yet, in disputes between transnational contracting parties, simple interest awards are the norm. This odd disparity between awards of international tribunals and standard business norms can have striking consequences. In disputes between transnational contracting parties, awards of interest are often

John Gotanda

342

Cancer prevention by natural compounds.  

PubMed

Increasing attention is being paid to the possibility of applying cancer chemopreventive agents for individuals at high risk of neoplastic development. For this purpose by natural compounds have practical advantages with regard to availability, suitability for oral application, regulatory approval and mechanisms of action. Candidate substances such as phytochemicals present in foods and their derivatives have been identified by a combination of epidemiological and experimental studies. Plant constituents include vitamin derivatives, phenolic and flavonoid agents, organic sulfur compounds, isothiocyanates, curcumins, fatty acids and d-limonene. Examples of compounds from animals are unsaturated fatty acids and lactoferrin. Recent studies have indicated that mechanisms underlying chemopreventive potential may be combinations of anti-oxidant, anti-inflammatory, immune-enhancing, and anti-hormone effects, with modification of drug-metabolizing enzymes, influence on the cell cycle and cell differentiation, induction of apoptosis and suppression of proliferation and angiogenesis playing roles in the initiation and secondary modification stages of neoplastic development. Accordingly, natural agents are advantageous for application to humans because of their combined mild mechanism. Here we review naturally occurring compounds useful for cancer chemprevention based on in vivo studies with reference to their structures, sources and mechanisms of action. PMID:15499193

Tsuda, Hiroyuki; Ohshima, Yutaka; Nomoto, Hiroshi; Fujita, Ken-ichi; Matsuda, Eiji; Iigo, Masaaki; Takasuka, Nobuo; Moore, Malcolm A

2004-08-01

343

Making Models of Chemical Compounds.  

ERIC Educational Resources Information Center

Describes the benefits and techniques of having students create models of chemical compounds. This hands-on approach uses colored paper and other inexpensive materials to construct the models. A step-by-step approach provides objectives, materials, an explanation on how to calculate chemical ratios, procedures, follow-up activities, and a resource…

Hoehn, Robert G.

1992-01-01

344

Assignment kernels for chemical compounds  

Microsoft Academic Search

During the last years kernel methods like the support vector machine (SVM) have gained a growing interest in machine learning. One of the strengths of this approach is the ability to deal easily with arbitrarily structured data by means of the kernel function. In this paper we propose a kernel for chemical compounds which is based on the idea of

Holger Fröhlich; Jörg K. Wegner; Andreas Zell

2005-01-01

345

Artificial compound eye zoom camera  

Microsoft Academic Search

We demonstrate a highly compact image capturing system with variable field of view but without any mechanically moving parts. The camera combines an ultra-thin artificial apposition compound eye with one variable focal length liquid lens. The change of optical power of the liquid lens when applying a voltage results in a change of the magnification of the microlens array imaging

Jacques Duparré; Frank Wippermann; Peter Dannberg; Andreas Bräuer

2008-01-01

346

Artificial compound eye applying hyperacuity  

Microsoft Academic Search

Inspired by the natural phenomenon of hyperacuity, redundant sampling in combination with the knowledge about the impulse response of the imaging system is used to extract highly accurate information using a low resolving artificial apposition compound eye. Thus the implementation of a precise position detection for simple objects like point sources and edges is described.

Andreas Brückner; Jacques Duparré; Andreas Bräuer; Andreas Tünnermann

2006-01-01

347

Madelung constants for layer compounds  

Microsoft Academic Search

The Madelung constants for the transition metal dichalcogenide layer compounds have previously been evaluated by Shen and Liang (1983) by a direct summation method. It is shown that the use of the two-dimensional Poisson summation formula gives a much more efficient method of evaluating the lattice sums.

N. A. Johnston; C. A. Sholl

1984-01-01

348

Microbiological Degradation of Phenol Compounds.  

National Technical Information Service (NTIS)

Reasons for the occurrence of phenols, especially in water and sewage, are discussed. These compounds distinctly affect the biocoenosis of the receiver both in respect to higher organisms, as e.g., fish, as well as to microorganisms. Thanks to adaptation ...

M. Zdybiewska

1968-01-01

349

Oxidation of advanced intermetallic compounds  

Microsoft Academic Search

Intermetallic compounds with low densities and high melting temperatures are prime structural material candidates for advanced heat engines. The close link between crystal structure and mechanical properties has led the search for new cubic pseudo-binary transition metal aluminides. Compositing leads the way for improved mechanical properties of refractory metal silicides. In all cases there is a strong competition for oxide

N. S. Bornstein

1993-01-01

350

Organochlorine compounds in aquatic environments  

Microsoft Academic Search

The body burdens of five organochlorine compounds were determined in several marine fishes and invertebrates from two localities in Norway. DDE, PCBs, and pentachlorobenzene showed uniform levels, especially on a fat weight basis, while hexachlorobenzene and octachlorostyrene were detected at various levels in the different species.

J. E. Bjerk; E. M. Brevik

1980-01-01

351

Industrial Electrosynthesis of Organic Compounds.  

National Technical Information Service (NTIS)

Electrochemical methods are beginning to find uses in the synthesis of different classes of organic compounds with a high degree of purity. The processes of electrochemical synthesis in large-tonnage of some monomers are of special interest because of the...

M. Y. Fioshin A. P. Tomilov

1968-01-01

352

Compound-Compressible Nozzle Flow.  

National Technical Information Service (NTIS)

A one-dimensional theory based upon fundamental flow relationships is presented for analyzing the behavior of one or more gas streams flowing through a single nozzle. This compound-compressible flow theory shows that the behavior of each stream is influen...

A. Bernstein C. Hevenor

1982-01-01

353

The valuation of compound options  

Microsoft Academic Search

can be generalized to value many corporate liabilities. The compound call option formula derived herein considers a call option on stock which is itself an option on the assets of the lirm. This perspective incorporates leverage effects into option pricing and consequently the variance of the rate of return on the stock is not constant as Black-&holes assumed, but is

Robert Geske

1979-01-01

354

Carbonyl Compounds in Toasted Oat Flakes  

Microsoft Academic Search

THE nut-like flavour of properly toasted oat flakes is associated with volatile and non-volatile compounds developing mostly during the toasting process. The volatile compounds are represented primarily by carbonyl compounds. Their amount, and in some cases even the content, are much higher after processing. In the original oat flakes, only slightly steamed, we established the presence of the following compounds:

Jirí Hrdlcka; Gustav Janícek

1964-01-01

355

New compounds of natural resources in 2008  

Microsoft Academic Search

Natural products have been the most productive source of new compounds. Hundreds of new compounds are in development. Some of them have pharmaceutical activities, particularly as anti- cancer and anti-infective agents. Until October, there are 1913 new compounds separated from natural sources in 2008. The compounds have covered a wide range of species, including alkaloids, flavones, terpenoids and so on.

Jinhui Wang; Qing Peng; Guoyu Li

356

Large Constituent Families Help Children Parse Compounds  

ERIC Educational Resources Information Center

|The family size of the constituents of compound words, or the number of compounds sharing the constituents, has been shown to affect adults' access to compound words in the mental lexicon. The present study was designed to see if family size would affect children's segmentation of compounds. Twenty-five English-speaking children between 3;7 and…

Krott, Andrea; Nicoladis, Elena

2005-01-01

357

Dioxouranium(VI)-carboxylate complexes. A calorimetric and potentiometric investigation of interaction with oxalate at infinite dilution and in NaCl aqueous solution at I=1.0 mol L(-1) and T=25 degrees C.  

PubMed

In this paper we investigated the interactions between dioxouranium(VI) and oxalate using (H(+)-glass electrode) potentiometry and titration calorimetry. Potentiometric measurements were carried out in NaCl aqueous solutions and at T=25 degrees C in a wide range of experimental conditions (concentrations, ligand/metal molar ratio, pH, titrants) at low ionic strength values (I< or =0.090mol L(-1), without supporting electrolyte) and at I=1.0mol L(-1); different procedures were employed for the acquisition of experimental data and careful analysis of these data performed. In all cases the speciation model that best fits experimental data takes into account the formation of the binary mononuclear species UO(2)(ox)(0), UO(2)(ox)(2)(2-), UO(2)(ox)(3)(4-) widely reported in literature, the ternary hydroxyl mononuclear species UO(2)(ox)OH(-), UO(2)(ox)(OH)(2)(2-), UO(2)(ox)(2)OH(3-), UO(2)(ox)(3)OH(5-), the protonated ternary mononuclear species UO(2)(ox)(3)H(3-) and the binuclear species (UO(2))(2)(ox)(5)(6-). Calorimetric measurements were carried out following similar procedures and in the same experimental conditions as employed for the potentiometric measurements at I=1.0mol L(-1) in NaCl. The stability of UO(2)(2+)-oxalate(2-) complexes is fairly high and their main contribution to stability is entropic in nature. Some linear empirical relationships were found which make it possible to calculate (i) the contribution of a single bond: DeltaG(sb) degrees =-16.6+/-0.2kJ mol(-1) and TDeltaS(sb) degrees =16.2+/-0.5kJ mol(-1); (ii) chelate stabilisation per ring: DeltaG(r) degrees =-1.30+/-0.04kJ mol(-1) and TDeltaS(r) degrees =1.27+/-0.23kJ mol(-1) and (iii) the mean stability of negatively charged Na(+)-ion pair complexes: log(T)K=(0.46+/-0.02).|z| (z=charge of complex species), DeltaG degrees =-(2.60+/-0.1).|z|kJ mol(-1) and TDeltaS degrees =2.5+/-0.5kJ mol(-1). Both potentiometric and calorimetric results provide evidence of the penta-coordination of the species UO(2)(ox)(3)(4-). SIT parameters were calculated from the data at I=0 and I=1.02mol kg(-1). Comparisons are made with literature data. An insoluble dioxouranium(VI) ternary complex was synthesised (at I=1.0mol L(-1) in NaCl) and characterised by thermoanalysis and elemental analysis. PMID:19071399

Crea, Francesco; De Robertis, Alessandro; De Stefano, Concetta; Sammartano, Silvio

2006-07-07

358

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

2008-10-17

359

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.

360

Bioactive compounds from Carissa spinarum.  

PubMed

In our continuing efforts to find new antiherpetic agents from plants, an extract prepared from the stems of Carissa spinarum L. was found to possess appreciable activity against herpes simplex viruses (HSV I and II). A chemical study of this plant was then initiated, and this led to the isolation of 12 compounds, including a coumarin, two cardiac glycosides and nine lignans. These isolated compounds were evaluated for several biological activities, including antiherpetic, cytotoxic, antioxidant and antibacterial effects. The cardiac glycoside evomonoside was found to be the only antiherpetic principle, showing moderate activity against herpes simplex virus types I and II in the inactivation method. The lignans (-)-carinol, (-)-carissanol and (-)-nortrachelogenin exhibited cytotoxicity against breast (MCF7) and lung (A549) cancer cells. Moderate anti-DPPH free radical activity was observed for all the lignans. None of the isolates showed antibacterial activity. PMID:22308099

Wangteeraprasert, Ruchira; Lipipun, Vimolmas; Gunaratnam, Mekala; Neidle, Stephen; Gibbons, Simon; Likhitwitayawuid, Kittisak

2012-02-06

361

Phytotoxic compounds from Flourensia cernua.  

PubMed

Bioassay-directed fractionation of a CH(2)Cl(2)-MeOH (1:1) extract of the aerial parts of Flourensia cernua led to the isolation of three phytotoxic compounds, namely, dehydroflourensic acid (1), flourensadiol (2) and methyl orsellinate (3). Dehydroflourensic acid is a new natural product whose structure was established by spectral means. In addition, the known flavonoid ermanin and seven hitherto unknown gamma-lactones were obtained, these being tetracosan-4-olide, pentacosan-4-olide, hexacosan-4-olide, heptacosan-4-olide, octacosan-4-olide, nonacosan-4-olide, and triacontan-4-olide. Compounds 1-3 caused significant inhibition of radicle growth of Amaranthus hypochondriacus and Echinochloa crus-galli, interacted with bovine-brain calmodulin and inhibited the activation of the calmodulin-dependent enzyme cAMP phosphodiesterase. PMID:12946427

Mata, Rachel; Bye, Robert; Linares, Edelmira; Macías, Martha; Rivero-Cruz, Isabel; Pérez, Olga; Timmermann, Barbara N

2003-09-01

362

[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

363

Aerobic degradation of aromatic compounds.  

PubMed

Our view on the bacterial responses to the aerobic degradation of aromatic compounds has been enriched considerably by the current omic methodologies and systems biology approaches, revealing the participation of intricate metabolic and regulatory networks. New enzymes, transporters, and specific/global regulatory systems have been recently characterized, and reveal that the widespread biodegradation capabilities extend to unexpected substrates such as lignin. A completely different biochemical strategy based on the formation of aryl-CoA epoxide intermediates has been unraveled for aerobic hybrid pathways, such as those involved in benzoate and phenylacetate degradation. Aromatic degradation pathways are also an important source of metabolic exchange factors and, therefore, they play a previously unrecognized biological role in cell-to-cell communication. Beyond the native bacterial biodegradation capabilities, pathway evolution as well as computational and synthetic biology approaches are emerging as powerful tools to design novel strain-specific pathways for degradation of xenobiotic compounds. PMID:23122741

Díaz, Eduardo; Jiménez, José Ignacio; Nogales, Juan

2012-11-01

364

Biological activity of vanadium compounds  

Microsoft Academic Search

Vanadium compounds are characterised by a broad spectrum of action in vivo and in vitro. Their insulin-mimetic activity is manifested in their ability to normalize changes observed in both clinical and experimental\\u000a diabetes (i.e. hyperglycaemia, hyperlipidaemia, lowered cell sensitivity to insulin) through the regulation of carbohydrate\\u000a and lipid metabolism and the removal of secondary symptoms of this disease (as e.g.

Anna Goc

2006-01-01

365

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

366

Bioactive Compounds from Northern Plants  

Microsoft Academic Search

\\u000a Northern conditions are characterised by long days with much light and low temperatures during the growing season. It has\\u000a been claimed that herbs and berries grown in the north are stronger tasting compared to those of southern origin. The compounds\\u000a imparting aroma and color to berries and herbs are secondary metabolites which in plants mostly act as chemical means of

Anja Hohtola; Giuseppina Rea; Bruno Berra

367

Artificial compound eye zoom camera.  

PubMed

We demonstrate a highly compact image capturing system with variable field of view but without any mechanically moving parts. The camera combines an ultra-thin artificial apposition compound eye with one variable focal length liquid lens. The change of optical power of the liquid lens when applying a voltage results in a change of the magnification of the microlens array imaging system. However, its effect on focusing of the individual microlenses can be neglected due to their small focal length. PMID:19029582

Duparré, Jacques; Wippermann, Frank; Dannberg, Peter; Bräuer, Andreas

2008-11-21

368

Compound TCP with Random Losses  

Microsoft Academic Search

We analyze the performance of a single, long-lived, Compound TCP (CTCP) connection in the presence of random packet losses.\\u000a CTCP is a new version of TCP implemented in Microsoft Windows to improve the performance on networks with large bandwidth\\u000a delay-products. We derive a Markovian model for the CTCP sending window and compute the steady state distribution of the window\\u000a and

Alberto Blanc; Konstantin Avrachenkov; Denis Collange; Giovanni Neglia

2009-01-01

369

Butyltin compounds in Portuguese wines.  

PubMed

Butyltin compounds are widespread contaminants that have also been found in some wines. The purpose of the present work was to make a survey of butyltin compounds in Portuguese wines. Forty-three table wines and 14 Port wines were analyzed for butyltin contents by using solid-phase microextraction gas chromatography mass spectrometry (SPME-GC-MS). In 14% of the analyzed wine samples, measurable dibutyltin (DBT) was found at concentrations ranging between 0.05 and 0.15 microg/L as Sn. Monobutyltin (MBT) was also observed (0.05 microg/L as Sn) in just a single wine. A search for the possible sources of DBT residues found in the wines was carried out. Therefore, some plastics and oak wood used in the process of wine-making, which have been directly in contact with the musts or the wines, were studied to check their possible release of butyltins. The eventual presence of DBT was also tested directly along the vinification process, from the must to the finished product. The results suggest that high-density polyethylene containers used in the transfer of wine in an early stage of the vinification process may be the main sources of these contaminants. Therefore, it is recommendable that plastic materials to be used in wineries be previously tested for the release of butyltin compounds. PMID:11958646

Azenha, Manuel; Vasconcelos, Maria Teresa

2002-04-24

370

Aluminum compounds as vaccine adjuvants.  

PubMed

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 that can be prevented by induction of serum antibodies, aluminum adjuvants formulated under optimal conditions are the adjuvants of choice. It is important to select carefully the type of aluminum adjuvant and optimize the conditions of adsorption for every antigen since this process is dependent upon the physico-chemical characteristics of both the antigens and aluminum adjuvants. Adsorption of antigens onto aluminum compounds depends heavily on electrostatic forces between adjuvant and antigen. Two commonly used aluminum adjuvants, aluminum hydroxide and aluminum phosphate have opposite charge at a neutral pH. The mechanism of adjuvanticity of aluminum compounds includes formation of a depot; efficient uptake of aluminum adsorbed antigen particles by antigen presenting cells due their particulate nature and optimal size (<10 µm); and stimulation of immune competent cells of the body through activation of complement, induction of eosinophilia and activation of macrophages. Limitations of aluminum adjuvants include local reactions, augmentation of IgE antibody responses, ineffectiveness for some antigens and inability to augment cell-mediated immune responses, especially cytotoxic T-cell responses. PMID:10837642

Gupta

1998-07-01

371

Perfluoro compounds as artificial erythrocytes.  

PubMed

Some liquid perfluoro compounds dissolve relatively large amounts of oxygen and can be used in dispersed form as substitutes for erythrocytes. The commonly used perfluoro compounds contain about the same amount of oxygen as do equal volumes of erythrocytes when equilibrated with 100% oxygen. However, when equilibrated with alveolar air, the perfluoro compounds contain much less oxygen than erythrocytes. The dispersed fluorochemicals are adequate substitutes for perfusion of isolated preparations of mammalian brain, heart kidney, lung and liver. However, when put into the circulation of the intact animal, the dispersed fluorochemicals tends to produce lesions of the lungs, dilation of the right heart, and ultimately fatal hypoxia. It is suggested that the course of events following intravenous injection of dispersed fluorochemical is initiated by an interaction of the perfluoro particles with blood platelets or blood clotting factors. The ensuing intravascular clotting could then cause the changes in the lungs which lead to a marked increase in pulmonary artery pressure and dilation of the right heart. These events would terminate in fatal hypoxia due to pulmonary pathology and heart failure. PMID:123863

Sloviter, H A

1975-05-01

372

Microbial degradation of halogenated compounds  

SciTech Connect

The mode of degradation of various halogenated compounds in isolated pure cultures and the disposition of the degradative genes have been studied. In many cases the degradative genes are found to be clustered on plasmids and appear to be under positive control. Genetic selection in vivo and genetic manipulations in vitro have allowed construction of strains having wider biodegradative potentials than their natural counterparts. Molecular cloning of the degradative gene clusters for halogenated compounds in vectors with a broad host range also allows the transfer of such genes to a large number of Gram-negative bacteria. The application of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)-degradading microorganisms has demonstrated the effectiveness of this strain in removing large amounts of 2,4,5-T from contaminated soil within a short period, and such soil has been shown to support the growth of plants normally sensitive to low concentrations of 2,4,5-T. The two major challenges that must be addressed in the near future are the development of appropriate microbial technology for the decontamination of soil containing hazardous halogenated compounds, and the promulgation of appropriate regulations to ensure the safety and well-being of the public during the application of genetically improved strains in an open environment.

Ghosal, D.; You, I.S.; Chatterjee, D.K.; Chakrabarty, A.M.

1985-04-12

373

[Detection of organic compounds on Mars].  

PubMed

McKay et al. detected polycyclic aromatic hydrocarbons (PAHs) in Martian meteorite ALH 84001 by two-step laser mass spectrometry. From the presence of PAHs, together with other results, they concluded that there were past life of Mars. On the other hands, no organisms nor organic compounds were detected in Martian regolith in Viking experiments in 1976. In order to obtain solid evidence for organisms or bioorganic compounds compounds on Mars, further analyses of Martian samples are required. There may be four classes of organic compounds on Mars, which are (i) organic compounds abiotically formed from primitive Mars atmosphere, (ii) Organic compounds delivered out of Mars, (iii) Organic compounds biotically formed by Mars organisms, and (iv) Organic compounds abiotically formed from the present Mars atmosphere. Possible organic compounds on Mars and analytical methods for them are discussed. PMID:11540350

Kobayashi, K

1997-03-01

374

Bioactive compounds from northern plants.  

PubMed

Northern conditions are characterised by long days with much light and low temperatures during the growing season. It has been chimed that herbs and berries grown in the north are stronger tasting compared to those of southern origin. The compounds imparting aroma and color to berries and herbs are secondary metabolites which in plants mostly act as chemical means of defense. Recently, the production of secondary metabolites using plant cells has been the subject of expanding research. Light intensity, photoperiod and temperature have been reported to influence the biosynthesis of many secondary metabolites. Native wild aromatic and medicinal plant species of different families are being studied to meet the needs of raw material for the expanding industry of e.g., health-promoting food products known as nutraceutics. There are already a large number of known secondary compounds produced by plants, but the recent advances in modern extraction and analysis should enable many more as yet unknown compounds to be found, characterised and utilised. Rose root (Rhodiola rosea) is a perennial herbaceous plant which inhabits mountain regions throughout Europe, Asia and east coastal regions of North America. The extract made from the rhizomes acts as a stimulant like the Ginseng root. Roseroot has been categorized as an adaptogen and is reported to have many pharmacological properties. The biologically active components of the extract are salitroside tyrosol and cinnamic acid glycosides (rosavin, rosarin, rosin). Round-leaved sundew (Drosera rotundifolia L.) has circumboreal distribution. It inhabits nutrient-poor, moist and sunny areas such as peat bogs and wetlands. Sundew leaves are collected from the wild-type for various medicinal preparations and can be utilized in treating e.g., as an important "cough-medicine" for different respiratory diseases. The antimicrobial activity of extracts of aerial parts against various bacteria has been investigated. Drosera produces various secondary metabolites. The most abundant, among these compounds, are the naphthoquinones. Bilberry (Vaccinium myrtillus) is a characteristic field layer species in boreal forests. Bilberry and other northern Vaccinium species, berries and leaves, contain high amounts of phenolic compounds. Bilberries are known for its exceptionally high amounts ofanthocyanins with powerful antioxidant capacity. They have been shown to possess beneficial health effects, like having a protective role in cardiovascular diseases and cancer. Many flavonoids also seem to have antiviral, antibacterial, antifungal and antiallergenic properties. The effect of ingested cranberry (V. oxycoccus) juice has been shown to prevent urinary tract infections in women. PMID:21520706

Hohtola, Anja

2010-01-01

375

Anaerobic biodegradation of aromatic compounds.  

PubMed

Many aromatic compounds and their monomers are existing in nature. Besides they are introduced into the environment by human activity. The conversion of these aromatic compounds is mainly an aerobic process because of the involvement of molecular oxygen in ring fission and as an electron acceptor. Recent literatures indicated that ring fission of monomers and obligomers mainly occurs in anaerobic environments through anaerobic respiration with nitrate, sulphate, carbon dioxide or carbonate as electron acceptors. These anaerobic processes will help to work out the better situation for bioremediation of contaminated environments. While there are plenty of efforts to reduce the release of these chemicals to the environment, already contaminated sites need to be remediated not only to restore the sites but to prevent the leachates spreading to nearby environment. Basically microorganisms are better candidates for breakdown of these compounds because of their wider catalytic mechanisms and the ability to act even in the absence of oxygen. These microbes can be grouped based on their energy mechanisms. Normally, the aerobic counterparts employ the enzymes like mono-and-dioxygenases. The end product is basically catechol, which further may be metabolised to CO2 by means of quinones reductases cycles. In the absense of reductases compounds, the reduced catechols tend to become oxidised to form many quinone compounds. The quinone products are more recalcitrant and lead to other aesthetic problems like colour in water, unpleasant odour, etc. On the contrary, in the reducing environment this process is prevented and in a cascade of pathways, the cleaved products are converted to acetyl co-A to be integrated into other central metabolite paths. The central metabolite of anaerobic degradation is invariably co-A thio-esters of benzoic acid or hydroxy benzoic acid. The benzene ring undergoes various substitution and addition reactions to form chloro-, nitro-, methyl- compounds. For complete degradation the side chains must be removed first and then the benzene ring is activated by carboxylation or hydroxylation or co-A thioester formation. In the next step the activated ring is converted to a form that can be collected in the central pool of metabolism. The third step is the channeling reaction in which the products of the catalysis are directed into central metabolite pool. The enzymes involved in these mechanisms are mostly benzyl co-A ligase, benzyl alcohol dehydrogenase. Other enzymes involved in this path are yet to be purified though many of the reactions products that have been theoretically postulated have been identified. This is mainly due to the instability of intermediate compounds as well as the association of the enzyme substrate is femoral and experimental conditions need to be sophisticated further for isolation of these enzymes. The first structural genes of benzoate and hydroxy benzoate ligases were isolated from Rhodopseudomonas palustris. This gene cluster of 30 kb size found in Rhodopseudomonas palustris coded for the Bad A protein. Similarly, some of the bph A,B,C and D cluster of genes coding for the degradation of pentachlorobenzenes were located in Pseudomonas pseudoalgaligenesKF 707. PMID:15242297

Jothimani, P; Kalaichelvan, G; Bhaskaran, A; Selvaseelan, D Augustine; Ramasamy, K

2003-09-01

376

Compounding USP <797>: inspection, regulation, and oversight of sterile compounding pharmacies.  

PubMed

Using USP Chapter <797> Pharmaceutical Compounding-Sterile Preparations (CSP) is now considered the standard for sterile compounding practice and safety in the United States. This is particularly important in compounding the complex formulation of parenteral nutrition. PMID:22275322

Kastango, Eric S

2012-01-24

377

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

378

Volatile flavor compounds in yogurt: a review.  

PubMed

Considerable knowledge has been accumulated on the volatile compounds contributing to the aroma and flavor of yogurt. This review outlines the production of the major flavor compounds in yogurt fermentation and the analysis techniques, both instrumental and sensory, for quantifying the volatile compounds in yogurt. The volatile compounds that have been identified in plain yogurt are summarized, with the few key aroma compounds described in detail. Most flavor compounds in yogurt are produced from lipolysis of milkfat and microbiological transformations of lactose and citrate. More than 100 volatiles, including carbonyl compounds, alcohols, acids, esters, hydrocarbons, aromatic compounds, sulfur-containing compounds, and heterocyclic compounds, are found in yogurt at low to trace concentrations. Besides lactic acid, acetaldehyde, diacetyl, acetoin, acetone, and 2-butanone contribute most to the typical aroma and flavor of yogurt. Extended storage of yogurt causes off-flavor development, which is mainly attributed to the production of undesired aldehydes and fatty acids during lipid oxidation. Further work on studying the volatile flavor compounds-matrix interactions, flavor release mechanisms, and the synergistic effect of flavor compounds, and on correlating the sensory properties of yogurt with the compositions of volatile flavor compounds are needed to fully elucidate yogurt aroma and flavor. PMID:21108074

Cheng, Hefa

2010-11-01

379

Low volatile organic compound paints  

SciTech Connect

Increasingly stringent air emission standards in various states has dictated the elimination of engineering finishes which are derived from high volatile organic compound (VOC) paint chemistries. In July 1989, Allied-Signal, Inc., Kansas City Division, Kansas City, Missouri, voluntarily closed its paint facility, due to non-compliance with local air emission standards. The following details the materials selection and evaluations which led to current processing using low VOC paints, which permitted the Allied Signal, Inc., paint facility to achieve compliance and resume operations. 1 tab.

Martinez, F.E.

1991-01-01

380

Deuterium labelled liquid crystalline compounds  

Microsoft Academic Search

The synthesis of 4-(2?-methylbutyl)phenyl4?n-heptylbiphenyl-4-carboxylate-d18(7BEF5-d18) is presented. The compound is intended to be used as a means of studying the collective modes of liquid crystals by the coherent inelastic neutron scattering technique. The 4?-n-heptylbiphenyl-4-carboxylic acid-d12, a liquid crystalline intermediate was prepared as well; its acid chloride was coupled with 4-(2?-methylbutyl)phenol-d6 to obtain the final product. The intermediates and final products were

K. Fodor-csorba; L. Bata; S. Holly; E. Gács-Baitz; K. Ujszászy

1993-01-01

381

Survey of Phenolic Compounds Produced in Citrus.  

National Technical Information Service (NTIS)

A survey of phenolic compounds, especially flavanones and flavone and flavonol compounds, using high pressure liquid chromatography was performed in Rutaceae, subfamily Aurantiodeae, representing 5 genera, 35 species, and 114 cultivars. The average number...

M. Berhow B. Tisserat K. Kanes C. Vandercook

1998-01-01

382

Therapeutic compounds isolated from Calomeria amaranthoides  

US Patent & Trademark Office Database

The present invention relates to extracts and compounds which are isolated from Calomeria amaranthoides, and to derivatives and analogues of such compounds, which demonstrate cytotoxic activity against a variety of cell types exhibiting hyperproliferative cell division.

2011-05-31

383

Monolayer-Forming Substituted Phthalocyanine Compounds.  

National Technical Information Service (NTIS)

This invention relates general to phthalocyanine compounds, and more particularly to the preparation of aryloxy, arylthio, alkyloxy, and alkylthio phthalocyanine compounds and their subsequent incorporation into semiconducting thin films by the Langmuir-B...

W. R. Barger N. L. Jarvis A. W. Snow H. Wohltjen

1985-01-01

384

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...

385

Studies on the Volatile Compounds in Mushrooms.  

National Technical Information Service (NTIS)

This publication summarizes studies on volatile natural compounds, especially those in fresh mushrooms. Using a combined GLC-MS method, an average of 50 volatile compounds were identified in each of the seven fresh mushrooms Cantharellus cibarius, Gyromit...

H. Pyysalo

1975-01-01

386

Calanolide Antiviral Compounds, Compositions and Uses Thereof.  

National Technical Information Service (NTIS)

The invention provides novel antiviral compounds, refered to as calanolides, and their derivatives, which may be isolated from plants of the genus Calophyllum in accordance with the inventive method. The compounds and their derivatives may be used alone o...

M. R. Boyd J. H. Cardellina K. R. Gustafson J. B. McMahon R. W. Fuller

1992-01-01

387

Mercury Compounds in Drugs and Food.  

National Technical Information Service (NTIS)

The Food and Drug Administration (FDA) is required to: (1) compile a list of drugs and foods that contain intentionally introduced mercury compounds, and (2) provide a quantitative and qualitative analysis of the mercury compounds in this list. The agency...

1999-01-01

388

5-Aryltetrazole Compounds and Uses Thereof.  

National Technical Information Service (NTIS)

The present invention relates to 5-Aryltetrazole Compounds, compositions comprising an effective amount of a a 5-Aryltetrazole Compound, and methods for treating an inflammation disease, a reperfusion disease, or hyperuricemia in an animal in need thereof...

A. Nivorozhkin A. Salzman G. Southan J. V. Duzer Q. Zeng S. Ram

2005-01-01

389

5-Aryltertrazoles Compounds and Compositions Thereof.  

National Technical Information Service (NTIS)

The present invention relates to 5-Aryltetrazole Compounds, compositions comprising an effective amount of a a 5-Aryltetrazole Compound, and methods for treating an inflammation disease, a reperfusion disease, or hyperuricemia in an animal in need thereof...

A. Nivorozhkin G. Southan J. V. Duzer Q. Zeng S. Ram

2005-01-01

390

Toxicological Profile for Manganese and Compounds.  

National Technical Information Service (NTIS)

The ATSDR Toxicological Profile is intended to characterize succinctly the toxicological and health effects information for manganese compounds. It identifies and reviews the key literature that describes manganese compounds' toxicological properties. Oth...

1992-01-01

391

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

392

Microbial Metabolism of Inorganic Sulfur Compounds  

Microsoft Academic Search

Inorganic sulfur compounds are used by microorganisms (bacteria, fungi, algae) and plants for assimilation, i.e. biosynthesis of sulfur-containing cell constituents.Quantitatively, within the biogeochemical cycle of sulfur the utilization of inorganic sulfur compounds in bacterial energy metabolism, i.e. dissimilatory sulfur utilization, is of far higher importance. Reduced sulfur compounds serve as electron donors for photosynthesis and respiration, whereas inorganic sulfur compounds

Hans G. Trüper

1985-01-01

393

Compounds and methods for treatment of cancer  

US Patent & Trademark Office Database

Compounds for treating, preventing or managing cancer are disclosed. Also provided are methods for using the compounds in treatment of various cancers. Also provided are methods of treatment using the compounds together with another chemotherapy, radiation therapy, hormonal therapy, biological therapy, or immunotherapy. Pharmaceutical compositions suitable for use in the methods are also disclosed.

2013-06-25

394

Toxicities of “excessively” chlorinated organic compounds  

Microsoft Academic Search

It is now recognized that chlorine can combine with a large variety of organics present in waste waters to form stable organochlorinated compounds (JOLLEY 1973). Moreover, the possible entry of these stable organochlorines into supplies of drinking water has prompted the monitoring of these compounds in many localities (EPA 1974, HARRIS 1974). JOLLEY (1973) identified seventeen stable organochlorine compounds in

Bernice M. Katz; Glenn M. Cohen

1976-01-01

395

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

396

Organic compounds in municipal landfill leachates  

Microsoft Academic Search

Leachates from three municipal landfills in the Göteborg area of western Sweden were characterised in terms of their content of individual organic compounds. Two of the investigated landfills were still in use during the time of this study. The third landfill was closed down in the mid-seventies. More than 200 individual organic compounds and classes of compounds were identified in

N. Paxéus

2000-01-01

397

Biologically active compounds of semi-metals  

Microsoft Academic Search

Semi-metals, viz. boron, silicon, arsenic, selenium, tellurium and astatine form organo-metal compounds, some of which are found in nature and have striking effects on the physiology of living organisms. Representatives of these compounds are, e.g., four boron-containing antibiotics (aplasmomycin, borophycin, boromycin, and tatrolon). Silicon compounds, frequently present in \\

T. ?ezanka; K. Sigler

2008-01-01

398

Antidiabetic and toxic effects of vanadium compounds  

Microsoft Academic Search

Compounds of the trace element vanadium have been shown to mimic insulin in in vitro and in vivo systems. These compounds have been found to exert anti-diabetic effects in rodent models of type 1 and type 2 diabetes mellitus as well as in a limited number of studies in human diabetic subjects. Thus, vanadium compounds have emerged as agents for

Ashok K. Srivastava

2000-01-01

399

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

400

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.

Hagen, Nathan; Tkaczyk, Tomasz S.

2011-01-01

401

[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

402

Diazo compounds: properties and synthesis  

SciTech Connect

This book is dedicated to Bernd Eistert, who did so much pioneering work with diazomethane. It is a review in two parts: Properties of Aliphatic Diazo Compounds (four chapters), and Synthesis of Aliphatic Diazo Compounds (12 chapters). Under properties are considered spectroscopy, thermal behavior, reactivity toward acids, and photochemistry. Other types of reactivity, such as the Arndt-Eistert Synthesis, are taken up in a chapter on Substitution Reactions of Diazoalkanes. This book is a rich source of information up to 1982, the termination of the literature coverage. An addendum, subdivided according to chapter, provides a condensed presentation of major developments from 1982 to 1986, but it is not complete and misses a number of things, such as the use of I,I-diacetoxyiodobenzene for oxidizing hydrazones to diazoalkanes. The discussion is in general critical and explanatory. Mechanism is incorporated throughout the text, with a careful distinction between what is established and what is speculative. Abundant, carefully drawn structural formulas contribute to the clarity of the work, and the many tables add to its reference value.

Regitz, M.; Maas, G.

1986-01-01

403

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

2012-11-28

404

INSENSITIVE HIGH-NITROGEN COMPOUNDS  

SciTech Connect

The conventional approach to developing energetic molecules is to chemically place one or more nitro groups onto a carbon skeleton, which is why the term ''nitration'' is synonymous to explosives preparation. The nitro group carries the oxygen that reacts with the skeletal carbon and hydrogen fuels, which in turn produces the heat and gaseous reaction products necessary for driving an explosive shock. These nitro-containing energetic molecules typically have heats of formation near zero and therefore most of the released energy is derived from the combustion process. Our investigation of the tetrazine, furazan and tetrazole ring systems has offered a different approach to explosives development, where a significant amount of the chemical potential energy is derived from their large positive heats of formation. Because these compounds often contain a large percentage of nitrogen atoms, they are usually regarded as high-nitrogen fuels or explosives. A general artifact of these high-nitrogen compounds is that they are less sensitive to initiation (e.g. by impact) when compared to traditional nitro-containing explosives of similar performances. Using the precursor, 3,6-bis-(3,5-dimethylpyrazol-1-yl)-s-tetrazine, several useful energetic compounds based on the s-tetrazine system have been synthesized and studied. Some of the first compounds are 3,6-diamino-s-tetrazine-1,4-dioxide (LAX-112) and 3,6-dihydrazino-s-tetrazine (DHT). LAX-112 was once extensively studied as an insensitive explosive by Los Alamos; DHT is an example of a high-nitrogen explosive that relies entirely on its heat of formation for sustaining a detonation. Recent synthesis efforts have yielded an azo-s-tetrazine, 3,3'-azobis(6-amino-s-tetrazine) or DAAT, which has a very high positive heat of formation. The compounds, 4,4'-diamino-3,3'-azoxyfurazan (DAAF) and 4,4'-diamino-3,3'-azofurazan (DAAzF), may have important future roles in insensitive explosive applications. Neither DAAF nor DAAzF can be initiated by laboratory impact drop tests, yet both have in some aspects better explosive performances than 1,3,5-triamino-2,4,6-trinitrobenzene TATB--the standard of insensitive high explosives. The thermal stability of DAAzF is equal to that of hexanitrostilbene (HNS), yet it too is a better explosive performer. The recently discovered tetrazol derivative, 3,6-bis-(1H-1,2,3,4-tetrazol-5-ylamino)-s-tetrazine (BTATz) was measured to have exceptional positive heats of formation and to be insensitive to explosive initiation. Because of its high burn rate with low sensitivity to pressure, this material is of great interest to the propellant community.

D. CHAVEZ; ET AL

2001-03-01

405

3,5-Diphenylpent-2-enoic acids as allosteric activators of the protein kinase PDK1: structure-activity relationships and thermodynamic characterization of binding as paradigms for PIF-binding pocket-targeting compounds.  

PubMed

The modulation of protein kinase activities by low molecular weight compounds is a major goal of current pharmaceutical developments. In this line, important efforts are directed to the development of drugs targeting the conserved ATP binding site. However, there is very little experience on targeting allosteric, regulatory sites, different from the ATP binding site, in protein kinases. Here we describe the synthesis, cell-free activation potency, and calorimetric binding analysis of 3,5-diphenylpent-2-enoic acids and derivatives as allosteric modulators of the phosphoinositide-dependent kinase-1 (PDK1) catalytic activity. Our SAR results combined with thermodynamic binding analyses revealed both favorable binding enthalpy and entropy and confirmed the PIF-binding pocket of PDK1 as a druggable site. In conclusion, we defined the minimal structural requirements for compounds to bind to the PIF-binding pocket and to act as allosteric modulators and identified two new lead structures (12Z and 13Z) with predominating binding enthalpy. PMID:19606904

Stroba, Adriana; Schaeffer, Francis; Hindie, Valerie; Lopez-Garcia, Laura; Adrian, Iris; Fröhner, Wolfgang; Hartmann, Rolf W; Biondi, Ricardo M; Engel, Matthias

2009-08-13

406

Antiviral phenolic compounds from Arundina gramnifolia.  

PubMed

Five new phenolic compounds, gramniphenols C-G (1-5), and eight known compounds (6-13) were isolated from the whole plant of Arundina gramnifolia. Compounds 1, 4, and 5 showed anti-tobacco mosaic virus activity, with IC(50) values of 20.8, 40.8, and 57.7 ?M, respectively. Compounds 1-10 were also tested for their anti-HIV-1 activity; compounds 2, 3, and 6 displayed anti-HIV-1 activity with therapeutic index values above 100:1. PMID:23368966

Hu, Qiu-Fen; Zhou, Bin; Huang, Jian-Ming; Gao, Xue-Mei; Shu, Li-Dan; Yang, Guang-Yu; Che, Chun-Tao

2013-01-31

407

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

408

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

409

Optical detection of alkali compounds  

SciTech Connect

Experiments to evaluate the photofragment fluorescence diagnostic technique for NaCl, KCl, and NaOH in terms of discrimination potential, sensitivity, and quantitative behavior have been completed. All results so far make this technique look very promising for potential applications in post-combustion coal gas streams. Based on the success of the investigations to date, we are continuing to expand the application of the photofragment technique to other gas-phase alkali compounds of importance in fossil fuel combustion. In particular, work is now in progress to investigate potassium hydroxide, KOH. Ongoing experiments are to determine (1) the optimum wavelength for K* production, (2) whether KOH can be measured in the presence of KCl, (3) if the signals linearly track the KOH monomer density, and (4) the absolute sensitivity of the technique for KOH in high-temperature environments.

Oldenborg, R.C.; Baughcum, S.L.

1986-01-01

410

Discretely tunable optofluidic compound microlenses.  

PubMed

We report a novel method to fabricate high zoom-ratio optofluidic compound microlenses using poly(dimethylsiloxane) with multi-layer architecture. The layered structure of deformable lenses, biconvex and plano-concave, are self-aligned as a group. The refractive index contrast of each lens, which is controlled by filling the chambers with a specific medium, is the key factor for determining the device's numerical aperture. The chip has multiple independent pneumatic valves that can be digitally switched on and off, pushing the liquid into the lens chambers with great accuracy and consistency. This quickly and precisely tunes the focal length of the microlens device from centimetres to sub-millimetre. The system has great potential for applications in portable microscopic imaging, bio-sensing, and laser beam configuration. PMID:21799999

Fei, Peng; He, Zi; Zheng, Chunhong; Chen, Tao; Men, Yongfan; Huang, Yanyi

2011-07-28

411

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

412

Electrohydrodynamics of a compound drop  

NASA Astrophysics Data System (ADS)

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.

Behjatian, Ali; Esmaeeli, Asghar

2013-09-01

413

Comparison of compound administration methods in biochemical assays: effects on apparent compound potency using either assay-ready compound plates or pin tool-delivered compounds.  

PubMed

Compound sample preparation and delivery are the most critical steps in high-throughput screening (HTS) campaigns. Historically, several methods of compound delivery to assays have been used for HTS, including intermediate plates with prediluted compounds, assay-ready plates (ARPs) using either preplated dried compound films or nanoliter DMSO spots of compounds, as well as pin tool-delivered compounds. We and others have observed differences in apparent compound potency depending on the compound delivery method. To quantitatively measure compound potency differences due to the chosen delivery methods, we conducted a controlled study using a validated biochemical luciferase assay and compared potencies when compounds were delivered in either ARPs (using acoustic dispensed nanoliter spots) or by pin tool. Here we compare hit rates, confirmation rates, false-positive rates, and false-negative rates between the two delivery methods using the luciferase assay. We compared polystyrene (PS) and cyclic olefin copolymer (COC) plates using both delivery methods and examined whether ARPs stored at 4 °C were superior to those stored frozen at -20 °C. The data show that the choice of compound delivery method to the assay has an effect on the apparent IC(50)'s and that pin tool delivery results in more confirmed hits than preplated compounds, resulting in a lower false-negative rate. However, this effect is minimized through the use of COC plates and by obtaining plates in a "just-in-time" mode. Overall, this report provides guidance on using assay-ready compound plates and has affected the way HTS campaigns are using acoustically dispensed plates in our department. PMID:22904199

Smith, Thomas; Ho, Pei-I; Yue, Kim; Itkin, Zina; MacDougall, Damien; Paolucci, Mike; Hill, Adam; Auld, Douglas S

2012-08-17

414

Compounding practices and beliefs of Arizona pharmacists.  

PubMed

Only a few studies have attempted to evaluate various aspects of pharmacy compounding such as the compounding practices and beliefs of pharmacists. Although these studies have reported valuable information, there remains a need to thoroughly assess this professional practice. The objectives of this study were to determine the prevalence of pharmacy compounding within Arizona, the reasons for which Arizona pharmacists do not participate in compounding, and the beliefs of Arizona pharmacists regarding contemporary compounding issues. Pharmacists licensed and residing in Arizona were mailed a postcard containing a brief description of the project and the URL to a 20-item online survey. Reminder postcards were mailed four weeks after the initial mailing, and the online survey was open to participants for two months. The usable response rate was 8.1% (412/5112). Respondents reported approximately 8.1% of all prescriptions and/or medication orders are compounded by a pharmacist with the most frequent aspect of compounding performed being reconstitution and/or flavoring of commercially available, nonsterile products. The most prevalent reason for not compounding was "not recieivng requests" (40%). "Preparation of alternate dosage forms" was the most beneficial aspect of compounding reported (93). The most cited educational method for teaching compounding was as "part of a required course with hands on experience" (76%) and 94% of respondents were taught by this method. Ninety-five percent of respondents agreed that compounding is an important part of the pharmacy profession. Overall, pharmacy compounding is fairly prevalent within Arizona and most respondents are supportive of compounding practices. PMID:23696176

Cauthon, Kimberly A B; Bowman, Bill J; Gurney, Mary K

415

Compound semiconductor surfaces and interfaces  

NASA Astrophysics Data System (ADS)

All semiconductor devices and integrated circuits require dielectric layers for interconnect isolation, gate oxides, passivation, etc. Thermally grown SiO2 is the primary dielectric film for silicon technology. This ONR contract investigated the chemistry and electrical properties of the interface between III-V compound semiconductors and electrical properties of grown and deposited oxides. When this study began, very little was known about these oxides or their interfaces. The results of the research supported by this contract has added substantially to the fundamental understanding of the oxide growth, properties and electronic structure. Much of the experimental work was obtained with surface analytical techniques and significant contributions were also made in this field. The original ONR contract began in October 1975 and initially concentrated on the grown oxides of InP and GaAs. This work evolved over the years to include the study of deposited insulator/InP interfaces and trapping at the interface. The ONR contract has supported the publication of 31 journal articles and book chapters and numerous conference presentations.

Wilmsen, C. W.

416

Thigtness Compound Climatic Test - QC  

NASA Astrophysics Data System (ADS)

This method determinate the suitabilty of materials components, finised products and others to stressful conditions like: cold, heat, UV and IR radiations others. Generally, the thigtness is testing in lab environmental conditions. But some materials, components or finised products are used transported or/and deposited in special climatic conditions. So when we test thighness we must mimic the environmental factors of aging. The samples are same elastomers of general use (used for gaskets). The rubber was studied using IR measurements. We studied the structural changes which appear due to the climatic factors on samples of N50 rubber. The elastomer was cooled and irradiated with UV radiation. Due to cooling a new spectral band at 1443 cm -1 appears, and also the intensity of spectral band from 1432 cm -1 decreases. The most important structural changes, due to the degradation action of the ultraviolet radiations, appear after 10 hours of the action of the aging factor. The rubber was also studied with photoacoustic technique. An important decrease of thermal diffusity with the number of climatic cycles (aging factor - cold) and the UV irradiations dose was observed for N50 type samples. We assume that a variety of structural changes have been produced. This kind of elastomer is not a resistent one to stressful conditions. The results proved that thigtness compound method QC, works, is a very imortant one and must be applied.

Cornelia Butnaru, Mariana

2006-11-01

417

Allorecognition between compound ascidian colonies.  

PubMed

The compound ascidian Botryllus schlosseri reproduces asexually, and forms colonies to adhere to matrices such as rocks. This species has developed a mechanism to distinguish between self stem cells and invasive parasitizing nonself cells from other individuals of the same species, probably as a defense against parasitism. It is highly likely that such adult colony histocompatibility is controlled differently from its gametic allorecognition during fertilization. Allorecognition in adults is controlled by a single fusion/histocompatibility (FuHC) locus. In 2005, a candidate gene responsible for the phenotype associated with this genetic locus, named cFuHC, was reported; however, this proposal was subsequently refuted, and the actual determinant may exist elsewhere within the FuHC locus. Given that its is unlikely that a single gene could produce the diversity of FuHC alleles needed to determine individual identity and to distinguish self from nonself colonies, it is possible that the FuHC locus consists of a cluster of multiple determinants aligned in tandem. PMID:24004073

Harada, Yoshito

2013-09-01

418

The content of compound conditioning.  

PubMed

In three experiments using Pavlovian conditioning of magazine approach, rats were trained with a compound stimulus, AB, and were concurrently trained with stimulus B on its own. The reinforcement rate of B, rB, was either 1/2, 2/3, or 2/5 of rAB. After extended training, the conditioning strength of A was assessed using probe trials in which A was presented alone. Responding during A was compared with that during AB, B, and a third stimulus, C, for which rC = rAB - rB. In each experiment, the rats' response rate during A was almost identical to that during C (and during B, when rB = 1/2rAB). This suggests that, during AB conditioning, the rats had learned about rA as being equal to [rAB - rB], and implies that the content of their learning was a linear function of r. The findings provide strong support for rate-based models of conditioning (e.g., Gallistel & Gibbon, 2000). They are also consistent with the associative account of learning defined in the Rescorla and Wagner (1972) model, but only if the learning rate during reinforcement equals that during nonreinforcement. PMID:22250789

Harris, Justin A; Andrew, Benjamin J; Livesey, Evan J

2012-01-16

419

Electroreduction of Halogenated Organic Compounds  

NASA Astrophysics Data System (ADS)

The electroreductive cleavage of the carbon-halogen bond in halogenated organic compounds has been extensively studied for more than 70 years, since it is prodromal to a large variety of synthetic applications in organic electrochemistry. Over the years the research interest have progressively included the environmental applications, since several organic halocompounds are known to have (or have had) a serious environmental impact because of their (present or past) wide use as cleaning agents, herbicides, cryogenic fluids, reagents (e.g. allyl and vinyl monomers) for large production materials, etc. Recent studies have also demonstrated the wide spread out- and in-door-presence of volatile organic halides, although at low level, in connexion with residential and non-residential (e.g. stores, restaurants and transportation) activities. In this context, the detoxification of emissions to air, water and land by the selective removal of the halogen group represents a valid treatment route, which, although not leading to the complete mineralization of the pollutants, produces less harmful streams to be easily treated by electrochemical or conventional techniques. The electroreduction process is analysed and discussed in terms of electrode material, reaction medium, cell design and operation, and of substrate classification.

Rondinini, Sandra; Vertova, Alberto

420

Bioactive compounds from Celaenodendron mexicanum.  

PubMed

Bioactivity-directed fractionation of the CHCl3-MeOH extract of the leaves of Celaenodendron mexicanum by means of the brine shrimp lethality test and chromatographic techniques led to the isolation of three carboxylic acid triterpenes, the new tirucalla-type triterpene, 3 alpha-hydroxytirucalla-7,24Z-dien-26-oic acid, 3-oxotirucalla-7,24Z-dien-26-oic acid, and epi-oleanolic acid, and three biflavonoids amentoflavone, podocarpusflavone A, and podocarpusflavone B. Four non-active compounds friedelin, maytensifolin B, 3 beta-hydroxyfriedelan-16-one, and celaenodendrolide were also obtained. epi-Oleanolic acid was the most active against brine shrimps with LC50 value of 23.3 microM. In addition, all isolates were tested for in vitro antiprotozoal and cytotoxic activities. 3-Oxotirucalla-7,24Z-dien-26-oic acid and epi-oleanolic acid showed the highest activity against Leishmania donovani promastigotes with IC50 values of 13.7 and 18.8 microM, respectively. Only 3-oxotirucalla-7,24Z-dien-26-oic acid showed activity against Trypanosoma brucei brucei bloodstream forms with IC50 value of 16.8 microM. PMID:10909269

Camacho, M R; Mata, R; Castaneda, P; Kirby, G C; Warhurst, D C; Croft, S L; Phillipson, J D

2000-06-01

421

Complex fragment emission from hot compound nuclei  

SciTech Connect

The experimental evidence for compound nucleus emission of complex fragments at low energies is used to interpret the emission of the same fragments at higher energies. The resulting experimental picture is that of highly excited compound nuclei formed in incomplete fusion processes which decay statistically. In particular, complex fragments appear to be produced mostly through compound nucleus decay. In the appendix a geometric-kinematic theory for incomplete fusion and the associated momentum transfer is outlined. 10 refs., 19 figs.

Moretto, L.G.

1986-03-01

422

Stability of C60 fullerite intercalation compounds  

Microsoft Academic Search

We construct a thermodynamic Born-Haber cycle to predict formation energies of donor- and acceptor-based C60 fullerite intercalation compounds with different stoichiometries. Energies associated with the individual steps in the cycle contain important related information such as the lattice constant, bulk modulus, and phonon spectra of the compounds. Our results indicate that alkali and alkaline-earth intercalated fullerite compounds are most stable.

Yang Wang; David Tománek; George F. Bertsch; Rodney S. Ruoff

1993-01-01

423

A Investigation of Some Lithium Insertion Compounds  

Microsoft Academic Search

Lithium insertion compounds are of technical interest as storage-battery electrodes; they are also of scientific interest as they offer low-temperature synthetic routes to compounds having unusual atomic ordering and to formal valence states that may not be accessible at higher temperatures normally employed in solid-state reactions. In this study lithium insertion compounds have been investigated to understand structure-property relationships of

Geeta Ahuja

1991-01-01

424

Oxygen stabilized zirconium vanadium intermetallic compound  

DOEpatents

An oxygen stabilized intermetallic compound having the formula Zr.sub.x OV.sub.y where x=0.7 to 2.0 and y=0.18 to 0.33. The compound is capable of reversibly sorbing hydrogen at temperatures from -196.degree. C. to 450.degree. C. at pressures down to 10.sup.-6 Torr. The compound is also capable of selectively sorbing hydrogen from gaseous mixtures in the presence of CO and CO.sub.2.

Mendelsohn, Marshall H. (Woodridge, IL); Gruen, Dieter M. (Downers Grove, IL)

1982-01-01

425

The natural production of organobromine compounds  

Microsoft Academic Search

Organobromine chemicals are produced naturally by an array of biological and other chemical processes in our environment.\\u000a Some of these compounds are identical to man-made organobromine compounds, such as methyl bromide, bromoform, and bromophenols,\\u000a but many others are entirely new moleclar entities, often possessing extraordinary and important biological properties. Although\\u000a only a few natural organobromine compounds had been discovered up

Gordon W. Gribble

2000-01-01

426

Process for synthesizing compounds from elemental powders  

DOEpatents

A process for synthesizing intermetallic compounds from elemental powders. The elemental powders are initially combined in ratio a which approximates the stoichiometric composition of the intermetallic compound. The mixed powders are then formed into a compact which is heat treated at a controlled rate of heating such that an exothermic reaction between the elements is initiated. The heat treatment may be performed under controlled conditions ranging from a vacuum (pressureless sintering) to compression (hot pressing) to produce a desired densification of the intermetallic compound. In a preferred form of the invention, elemental powders of Fe and Al are combined to form aluminide compounds of Fe{sub 3}Al and FeAl.

Rabin, B.H.; Wright, R.N.

1990-01-01

427

Process for synthesizing compounds from elemental powders  

DOEpatents

A process for synthesizing intermetallic compounds from elemental powders. The elemental powders are initially combined in ratio a which approximates the stoichiometric composition of the intermetallic compound. The mixed powders are then formed into a compact which is heat treated at a controlled rate of heating such that an exothermic reaction between the elements is initiated. The heat treatment may be performed under controlled conditions ranging from a vacuum (pressureless sintering) to compression (hot pressing) to produce a desired densification of the intermetallic compound. In a preferred form of the invention, elemental powders of Fe and Al are combined to form aluminide compounds of Fe{sub 3}Al and FeAl.

Rabin, B.H.; Wright, R.N.

1990-12-31

428

PLUTONIUM COMPOUNDS AND PROCESS FOR THEIR PREPARATION  

DOEpatents

This patent relates to certain new compounds of plutonium, and to the utilization of these compounds to effect purification or separation of the plutonium. The compounds are organic chelate compounds consisting of tetravalent plutonium together with a di(salicylal) alkylenediimine. These chelates are soluble in various organic solvents, but not in water. Use is made of this property in extracting the plutonium by contacting an aqueous solution thereof with an organic solution of the diimine. The plutonium is chelated, extracted and effectively separated from any impurities accompaying it in the aqueous phase.

Wolter, F.J.; Diehl, H.C. Jr.

1958-01-01

429

Automated compound classification using a chemical ontology  

PubMed Central

Background Classification of chemical compounds into compound classes by using structure derived descriptors is a well-established method to aid the evaluation and abstraction of compound properties in chemical compound databases. MeSH and recently ChEBI are examples of chemical ontologies that provide a hierarchical classification of compounds into general compound classes of biological interest based on their structural as well as property or use features. In these ontologies, compounds have been assigned manually to their respective classes. However, with the ever increasing possibilities to extract new compounds from text documents using name-to-structure tools and considering the large number of compounds deposited in databases, automated and comprehensive chemical classification methods are needed to avoid the error prone and time consuming manual classification of compounds. Results In the present work we implement principles and methods to construct a chemical ontology of classes that shall support the automated, high-quality compound classification in chemical databases or text documents. While SMARTS expressions have already been used to define chemical structure class concepts, in the present work we have extended the expressive power of such class definitions by expanding their structure-based reasoning logic. Thus, to achieve the required precision and granularity of chemical class definitions, sets of SMARTS class definitions are connected by OR and NOT logical operators. In addition, AND logic has been implemented to allow the concomitant use of flexible atom lists and stereochemistry definitions. The resulting chemical ontology is a multi-hierarchical taxonomy of concept nodes connected by directed, transitive relationships. Conclusions A proposal for a rule based definition of chemical classes has been made that allows to define chemical compound classes more precisely than before. The proposed structure-based reasoning logic allows to translate chemistry expert knowledge into a computer interpretable form, preventing erroneous compound assignments and allowing automatic compound classification. The automated assignment of compounds in databases, compound structure files or text documents to their related ontology classes is possible through the integration with a chemical structure search engine. As an application example, the annotation of chemical structure files with a prototypic ontology is demonstrated.

2012-01-01

430

27 CFR 27.44 - Other compounds and preparations.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 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...

2009-04-01

431

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

432

Calorimetric particle detectors with superconducting absorber materials  

NASA Astrophysics Data System (ADS)

Massive superconducting absorbers of molybdenum and vanadium are used as low temperature calorimeter particle detectors. The high temperature resolution of the thermometry system, consisting of a superconducting phase transition thermometer monitored with a DC Squid, enables the detection of alpha particles with large single crystals. With a 35 g molybdenum single crystal, an energy resolution of 10 percent Full Width Half Maximum (FWHM) on 5.8 MeV alpha particles is obtained. The observed temperature rise of 1.2 mK is a factor of eight less than expected from the calculated heat capacity. Using a 15g vanadium single crystal, the energy resolution in 5.8 MeV alpha particles is 1.2 percent FWHM. In this case, the pulse height is a factor of five smaller than expected from the calculated heat capacity. A possible reason for the large deviations from the expected heat capacity is the presence of hydrogen dissolved in these transition metals, another reason might be the presence of surface impurities or defects.

Forster, G.; Ferger, P.; Feilitzsch, F. V.; Moessbauer, R. L.; Azgui, F.; Igalson, J.

1991-11-01

433

The CDF level 2 calorimetric trigger upgrade  

SciTech Connect

CDF II upgraded the calorimeter trigger to cope with the higher detector occupancy due to the increased Tevatron instantaneous luminosity ({approx} 2.8 x 10{sup 32} cm{sup -2} s{sup -1}). While the original system was implemented in custom hardware and provided to the L2 trigger a limited-quality jet clustering performed using a reduced resolution measurement of the transverse energy in the calorimeter trigger towers, the upgraded system provides offline-quality jet reconstruction of the full resolution calorimeter data. This allows to keep better under control the dependence of the trigger rates on the instantaneous luminosity and to improve the efficiency and purity of the trigger selections. The upgraded calorimeter trigger uses the general purpose VME board Pulsar, developed at CDF II and already widely used to upgrade the L2 tracking and L2 decision systems. A battery of Pulsars is used to merge and send the calorimeter data to the L2 CPUs, where software-implemented algorithms perform offline-like clustering. In this paper we review the design and the performance of the upgraded system.

Bhatti, A.; /Rockefeller U.; Canepa, A.; /Pennsylvania U.; Casarsa, M.; /INFN, Pisa /Pisa U. /Pisa, Scuola Normale Superiore; Convery, M.; /Fermilab; Cortiana, G.; /Padua U. /INFN, Padua; Dell'Orso, M.; /INFN, Pisa /Pisa U. /Pisa, Scuola Normale Superiore; Donati, S.; /INFN, Pisa /Pisa U. /Pisa, Scuola Normale Superiore; Flanagan, G.; /Purdue U.; Frisch, H.; /Chicago U., EFI; Fukun, T.; /Chicago U., EFI; Krop, D.; /Chicago U., EFI /INFN, Pisa /Pisa U. /Pisa, Scuola Normale Superiore

2009-01-01

434

Calorimetric Determination of Aqueous Ion Enthalpies  

NASA Astrophysics Data System (ADS)

Enthalpies of formation of aqueous ions can be determined by solution calorimetry. This article describes an experiment for the physical chemistry laboratory. Enthalpies of formation of aqueous sodium, potassium, chloride and iodide ions are calculated from the enthalpies of solution of salts. The enthalpies of solution are measured with the Parr 1455 solution calorimeter. The calorimeter is controlled and data are collected by a computer attached to the calorimeter's serial port. The experiment is simple and yields results that are in good agreement with literature values.

Siders, Paul

1997-02-01

435

Calorimetric analysis of fungal degraded wood  

SciTech Connect

Endothermic transition and gross heat of combustion of aspenwood subjected to degradation by Lenzites trabea and Polyporus versicolor were determined by using differential scanning calorimetry (DSC) and an adiabatic O bomb. Endothermic peak areas of undegraded and fungi-degraded wood differed from each other at all levels of weight loss. The regression analysis of the DSC data vs. weight loss revealed a significant relations, although not highly correlated, for P. versicolor-degraded specimens and a nonsignificant relation for L. trabea-degraded specimens; weight loss and gross heat of combustion values of degraded specimens were significantly correlated.

Blankenhorn, P.R.; Baldwin, R.C.; Merrill, W. Jr.; Ottone, S.P.

1980-01-01

436

Mutagenicity of nitroaromatic degradation compounds.  

PubMed

The mutagenicity of 2,4-dinitrotoluene (24DNT), and 2,6-dinitrotoluene (26DNT), and their related transformation products such as hydroxylamine and amine derivatives, which are formed by Clostridium acetobutylicum, were tested in crude cell extracts using Salmonella typhimurium TA100. A previous publication already reported the mutagenic activities of 2,4,6-trinitrotoluene (TNT) and its related hydroxylamine derivatives in this test system. A time course of the mutagenicity during the anaerobic transformation of TNT, 24DNT, and 26DNT was also investigated under the same conditions to compare with the results from the pure compounds. The monohydroxylamino intermediates 2-hydroxylamino-4-nitrotoluene (2HA4NT), 4-hydroxylamino-2-nitrotoluene (4HA2NT) and 2-hydroxylamino-6-nitrotoluene (2HA6NT) formed during anaerobic transformation of dinitrotoluenes were proven to be mutagenic in the Ames test using Salmonella typhimurium TA100. This study reports that 4HA2NT is the most stable derivative, whereas 2HA4NT and 2HA6NT are less stable and these intermediates are mutagenic in the Ames test. Both 24DNT and 26DNT and their final metabolites 2,4-diaminotoluene (24DAT) and 2,6-aminotoluene (26DAT) appeared nonmutagenic. In a time-course study of TNT degradation, the temporal sample containing 85% of 2,4-dihydroxylamino-6-nitrotoluene (24HA6NT) is most mutagenic. These observations suggest that the bioremediation approach for treatment of 24DNT and 26DNT should be carried past the hydroxylamino intermediate. PMID:14551991

Padda, Ranjit S; Wang, Chuanyue; Hughes, Joseph B; Kutty, Razia; Bennett, George N

2003-10-01

437

A Low-Temperature Calorimetric Study of Forsterite-Fayalite (Mg2SiO4-Fe2SiO4) Solid Solutions: An Analysis of Vibrational, Magnetic and Electronic Contributions to the Heat Capacity and Entropy of Mixing  

NASA Astrophysics Data System (ADS)

Orthosilicate olivine in the system Mg2SiO4-Fe2SiO4 (forsterite-fayalite) is a major phase in the solar system. It occurs in several types of meteorites and also on different planets and their moons. On Earth, Fe-Mg olivine is the most abundant phase of Earth's upper mantle and is an important mineral in mafic und ultramafic igneous and metamorphic rocks. Knowledge of its thermodynamic properties is crucial for undertaking many mineralogical, petrological and geophysical investigations. The heat capacities (Cp) of a series of synthetic forsterite (Fo)-fayalite (Fa) olivines have been measured between 5 and 300 K on milligram-sized samples using a new calorimetric method - heat pulse calorimetry. Sharp, ?-type Cp-anomalies are observed in the Fe-rich compositions Fa, Fo10Fa90, Fo20Fa80, Fo30Fa70 and Fo40Fa60. The corresponding Neel temperatures TN decrease linearly from 64.5 K in Fa to 32.8 K in Fo40Fa60 following the relationship TN = 79.02*XFa - 14.07. Fo50Fa50 and Mg-richer olivines show weak broad features in the Cp data around 15-20 K that decrease in magnitude with increasing Fo content in olivine. In order to obtain and separate electronic, magnetic and vibrational heat capacity contributions, Cel, Cmag, and Cvib from the experimental Cp's (Ctot), we used a single- parameter phonon dispersion model to calculate Cvib for the solid-solution members. The Cel + Cmag (i.e., Ctot - Cvib) contributions were fit to expressions describing a Schottky-type electronic anomaly and a paramagnetic-antiferromagnetic transition. For Fo50Fa50 and Mg-richer olivines, our analysis of Ctot shows that also these compositions have a Cmag contribution with a maximum around 25 K. Decomposition of the excess heat capacity (?Cp^{xs}) into corresponding electronic, magnetic and vibrational contributions yields the largest absolute values for ?C^{mag,xs}. Excess entropies of mixing, ?S^{xs}, were also calculated from the Cp data. ?S^{mag,xs} at 298.15 K is weakly negative for the solid solution (approx. -2 J/Kmol, because positive and negative Cp contributions as a function of temperature largely cancel each other between 0 and 300 K. ?C^{el,xs} is positive for all temperatures and compositions, ?S^{el,xs} thus gives a positive contribution with a maximum of 0.8 J/Kmol for Fo50Fa50. ?S^{vib,xs} is also slightly positive for most members (maximum of 1.2 J/Kmol for Fo40Fa60). The resulting overall excess entropy, ?S^{xs} = ?S^{vib,xs} + ?S^{el,xs} + ?S^{mag,xs}, at 298.15 K along the Fo-Fa join is zero within 2?-uncertainty.

Dachs, E.; Geiger, C. A.; von Seckendorff, V.; Grodzicki, M.

2006-12-01

438

(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...

439

Interactions among salty, sour and bitter compounds  

Microsoft Academic Search

The human gustatory system is capable of responding to and processing the taste of solitary compounds in water. However, the taste system rarely contacts solitary compounds outside the laboratory and has surely evolved to process complex mixtures of sapid chemicals, such as occur in virtually all foods. This review will focus primarily on the lesser-studied interactions between pairs of salty,

Paul A. S. Breslin

1996-01-01

440

Evolution of aroma compounds in sparkling ciders  

Microsoft Academic Search

This paper reports the influence of yeast strain and aging time on the volatile composition of sparkling cider made according to the traditional method. Two sparkling ciders were obtained from the same base cider using a selected cider yeast strain (Saccharomyces bayanus) and a commercial wine yeast strain (Saccharomyces cerevisiae). Analysis of volatile compounds (alcohols, esters and carbonylic compounds) were

Roberto Rodríguez Madrera; Ana García Hevia; Noemí Palacios García; Belén Suárez Valles

2008-01-01

441

Contact conformers in crystals of coordination compounds  

Microsoft Academic Search

In a continuation of the systematic study of contact conformers (coexisting molecules having different structures), a comparison of the structures of symmetrically independent molecules inthe crystals of 37 coordination compounds have been compared. Fourteen cases of contact conformers have been detected and systematized. The earlier suggestion that contact conformers are more typical of crystals of coordination compounds than of organic

E. É. Lavut; P. M. Zorkii; N. Yu. Chernikova

1982-01-01

442

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

443

Ionisation Potentials of Aromatic and Heterocyclic Compounds  

Microsoft Academic Search

The relation between the ionisation potentials of aromatic and heterocyclic compounds and their electronic structures is considered. The nature of the orbitals in the ground states of molecules of different structures is examined on the basis of an analysis of the ionisation potentials. It has been shown how substituents affect the positions of the electronic levels of aromatic compounds. The

V. K. Potapov

1970-01-01

444

Silicates and Silicones. Compounds for the Future.  

National Technical Information Service (NTIS)

'Silicates and Silicones - Compounds for the Future' is the title of a report containg six lectures given at a symposium arranged in Stockholm on May 21, 1984, by the Royal Swedish Academy of Engineering Sciences, IVA. Silicon organic compounds with three...

1985-01-01

445

Interactions between polysaccharides and aroma compounds  

Microsoft Academic Search

The presence of interactions between several polysaccharides: modified and waxy starches, dextrin, dextrans, hydroxypropyl celluloses, galactomannans and model aroma compounds: limonene, isoamyl acetate, ethyl hexanoate and ß-ionone, was studied by the use of the exponential dilution technique. The observed decrease of the reduced infinite dilution activity coefficient of these compounds when the concentration of polysaccharides is increased shows that the

S. Langourieux; J. Crouzet

1995-01-01

446

Learning Compound Order: Towards a Functional Explanation  

Microsoft Academic Search

This project investigates the problem of learning compound order, from an interdisciplinaryperspective. Formal theories of linguistics have not addressed the question of why the constituentsforming verbal compounds are ordered the way they are. Research in linguistic typology andlanguage acquisition is critically examined, demonstrating the importance of the study of mentalrepresentation in explaining the development of morphological competence. Experimental resultsare reported

Scott McDonald

1995-01-01

447

Chemotherapeutic compounds and Acanthamoebae from eye infections  

Microsoft Academic Search

The amoebicidal and amoebistatic action in vitro of 24 compounds was tested on two strains of Acanthamoeba, A. polyphaga and A. castellanii, isolated from eye infections in this country. For comparison, the Ryan strain of A. castellanii and Naegleria gruberi L-1 were also examined. Nine compounds showed sufficient activity to merit further consideration, ie, acriflavine, proflavine, hydroxystilbamidine isethionate, paromomycin, miconazole,

J Nagington; J E Richards

1976-01-01

448

A novel phenolic compound from Phyllanthus emblica.  

PubMed

A new compound, mucic acid 3-O-gallate (1), was isolated from the fruit of Phyllanthus emblica L, together with 5 known compounds (2-6). Their structures were elucidated on the basis of spectroscopic analysis, including 1D and 2D NMR techniques, and by comparison with literature data. PMID:23738453

She, Gaimei; Cheng, Ruiyang; Sha, Lei; Xu, Yixia; Shi, Renbin; Zhang, Lanzhen; Guo, Yajian

2013-04-01

449

Stress relaxation in plastic molding compounds  

Microsoft Academic Search

Viscoelastic materials for plastic encapsulated molding compounds invariably exhibit a time-dependent stress response to an imposed constant strain, which is called stress relaxation. Stress relaxation tests with molding compounds used to encapsulate microcircuits have been performed to measure the time dependent non-linear constitutive relation between stress and strain as a function of temperature and imposed strain. In an effort to

Xingjia Huang; S. W. R. Lee

2002-01-01

450

Nitroaromatic compounds, from synthesis to biodegradation.  

PubMed

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

2010-06-01

451

Degradation of nitroaromatic compounds by microorganisms  

Microsoft Academic Search

Nitroaromatic compounds are abundantly present in nature, but are in most cases highly toxic to living organisms. Several microorganisms, however, are capable of mineralizing or converting these compounds. Until now four pathways for the complete degradation of nitroaromatics have been described, which start with either the oxygenolytic or reductive removal of the nitro group from the aromatic ring or with

F. D. Marvin-Sikkema; J. A. M. de Bont

1994-01-01

452

Spectroscopic properties of inorganic and organometallic compounds  

SciTech Connect

This book covers literature published up to late 1984. Includes nuclear magnetic resonance; nuclear quadrupole resonance spectroscopy; rotational spectroscopy; characteristic vibrations of compounds of main-group elements; vibrational spectra of transition-element compounds and some co-ordinated ligands; Mossbauer spectroscopy; and gas-phase molecular structures determined by electron diffraction.

Davidson, G.; Ebsworth, E.A.U.

1986-01-01

453

Mercury Compounds Reduce Photosynthesis by Plankton  

Microsoft Academic Search

Concentrations of organomercurial fungicides as low as 0.1 part per billion in water reduced photosynthesis and growth in laboratory cultures of one species of marine diatom and several natural phytoplankton communities from Florida lakes. The acute toxicity of mercury compounds to phytoplankton is dependent on the chemical nature of the mercury compound and on cell concentrations.

Robert C. Harriss; David B. White; Robert B. Macfarlane

1970-01-01

454

Mercury compounds reduce photosynthesis by plankton  

Microsoft Academic Search

Concentrations of organomercurial fungicides as low as 0.1 part per billion in water reduced photosynthesis and growth in laboratory cultures of one species of marine diatom and several natural phytoplankton communities from Florida lakes. The acute toxicity of mercury compounds to phytoplankton is dependent on the chemical nature of the mercury compound and on cell concentrations.

R. C. Harriss; D. B. White; R. B. Macfarlane

1970-01-01

455

Distributed imaging using compound eye sensors  

Microsoft Academic Search

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

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

2004-01-01

456

On the Structure of Phosphorus Compounds.  

National Technical Information Service (NTIS)

A discussion is presented of the basic principles underlying bonding in organic phosphorus compounds. A brief review is made of the position of organic chemistry in the chemical field and the primary uses of the compounds with which it deals. Subsequently...

R. Wolf

1974-01-01

457

Pyridinium Oxime Compounds as Antimicrobial Agents.  

National Technical Information Service (NTIS)

Pyridinium oxime compounds have been utilised by a number of military organisations as one of the antidotes for nerve-agent poisoning. In Canada, the preferred compound from this class is HI-6, which has been demonstrated to be tolerated at high doses wit...

B. J. Berger M. H. Knodel

2007-01-01

458

Deuterium Permeation through EPDM Rubber Compounds.  

National Technical Information Service (NTIS)

The permeation of deuterium through a specially formulated compound of ethylene propylene diene rubber was measured in the temperature range of 26/degree/C to 120/degree/C. The results were similar to permeation through two commercial compounds of this el...

P. E. Zapp

1988-01-01

459

Antileukaemic and Nephrotoxic Properties of Platinum Compounds  

Microsoft Academic Search

THE antitumour properties of certain inorganic platinum compounds in mice were first reported by Rosenberg et al.1. Of thirty-four compounds tested the cis-platinum (ii) diamminodichloride and the cis-platinum (iv) diamminotetrachloride had the highest activity, producing marked regression of large solid sarcoma 180 tumours in 63-100% of mice.

B. J. Leonard; E. Eccleston; D. Jones; P. Todd; A. Walpole

1971-01-01

460

Performance of BNL-TSTA compound cryopump  

SciTech Connect

A compound cryopump using cryocondensation pumping for hydrogen isotopes and cryosorption pumping with coconut charcoal as adsorbent for helium was designed. This compound cryopump was subsequently built (by Janis Research, Stoneham, MA) and has been tested at Brookhaven, fulfilling the design requirements and are delivered to Tritium Systems Test Assembly (TSTA) Vacuum Facility at Los Alamos Scientific Laboratory (LASL) for on-line operations.

Hseuh, H C; Worwetz, H A

1980-01-01

461

Micro-optical artificial compound eyes  

Microsoft Academic Search

Natural compound eyes combine small eye volumes with a large field of view at the cost of comparatively low spatial resolution. For small invertebrates such as flies or moths, compound eyes are the perfectly adapted solution to obtaining sufficient visual information about their environment without overloading their brains with the necessary image processing. However, to date little effort has been

J W Duparré; F C Wippermann

2006-01-01

462

Minerals Yearbook, 1990. Calcium and Calcium Compounds.  

National Technical Information Service (NTIS)

The U.S. Bureau of Mines publishes reports for a variety of calcium-containing minerals and compounds because of their commercial significance and contribution to the quality of human life. The 'Calcium and Calcium Compounds Annual Report' includes calciu...

M. M. Miller

1991-01-01

463

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

2011-12-14

464

Organo-arsenoxide compounds and use thereof  

US Patent & Trademark Office Database

The present invention relates to organo-arsenoxide compounds and to methods for their synthesis. The invention also relates to pharmaceutical compositions comprising these compounds and to their use in the treatment of diseases and disorders, in particular proliferative diseases and disorders, including treatment of solid tumors and leukaemia.

2012-09-18

465

Performance of BNL-TSTA compound cryopump  

Microsoft Academic Search

A compound cryopump using cryocondensation pumping for hydrogen isotopes and cryosorption pumping with coconut charcoal as adsorbent for helium was designed. This compound cryopump was subsequently built (by Janis Research, Stoneham, MA) and has been tested at Brookhaven, fulfilling the design requirements and are delivered to Tritium Systems Test Assembly (TSTA) Vacuum Facility at Los Alamos Scientific Laboratory (LASL) for

H. C. Hseuh; H. A. Worwetz

1980-01-01

466

Sulfamides in the synthesis of heterocyclic compounds  

Microsoft Academic Search

A comparative analysis of the structures and physicochemical properties of sulfamides and ureas has been performed. New procedures for the synthesis of heterocyclic compounds containing the sulfamide fragment are surveyed and the properties of the resulting compounds are described. The bibliography includes 112 references. Bibtex entry for this abstract Preferred format for this abstract (see Preferences) Find Similar Abstracts: Use:

Galina A. Gazieva; Angelina N. Kravchenko; Oleg V. Lebedev

2000-01-01

467

Sulfamides in the synthesis of heterocyclic compounds  

Microsoft Academic Search

A comparative analysis of the structures and physicochemical properties of sulfamides and ureas has been performed. New procedures for the synthesis of heterocyclic compounds containing the sulfamide fragment are surveyed and the properties of the resulting compounds are described. The bibliography includes 112 references.

Galina A Gazieva; Angelina N Kravchenko; Oleg V Lebedev

2000-01-01

468

Ruthenium-Catalyzed Synthesis of Heterocyclic Compounds  

Microsoft Academic Search

Heterocyclic compounds have been synthesized by means of stoichiometric reagents under acidic or basic conditions. Recent progress of homogeneous transition-metal catalysis realizes a highly selective and atom-economical methodology for synthesis of heterocycles under neutral and mild conditions. This review highlights the recent advances in the area of ruthenium-catalyzed syntheses of heterocyclic compounds.

Yoshihiko Yamamoto; Kenji Itoh