Search results for "calor"
showing 10 items of 866 documents
A standard calculation methodology for human doubly labeled water studies.
2021
Summary The doubly labeled water (DLW) method measures total energy expenditure (TEE) in free-living subjects. Several equations are used to convert isotopic data into TEE. Using the International Atomic Energy Agency (IAEA) DLW database (5,756 measurements of adults and children), we show considerable variability is introduced by different equations. The estimated rCO2 is sensitive to the dilution space ratio (DSR) of the two isotopes. Based on performance in validation studies, we propose a new equation based on a new estimate of the mean DSR. The DSR is lower at low body masses (<10 kg). Using data for 1,021 babies and infants, we show that the DSR varies non-linearly with body mass betw…
Pressure Effect Studies on the Spin‐Transition Behavior of a Dinuclear Iron(II) Compound
2013
Magnetic studies into the effect of different hydrostatic pressures between ambient and 1.03 GPa on the high-spin (HS) i low-spin (LS) transition behavior of the dinuclear iron(II) compound [Fe II 2(PMAT)2](BF4)4·DMF (1, PMAT = 4-amino3,5-bis{[(2-pyridylmethyl)amino]methyl}-4H-1,2,4-triazole, DMF = N,N-dimethylformamide) have been carried out at 2– 300 K. Under ambient pressure, the sample studied exhibits a [HS–HS] to [HS–LS] half spin transition (ST) at T½ = 208 K without any thermal hysteresis. Increasing the pressure above 0.2 GPa causes an increase (initially rapid but above 0.5 GPa more gradual) of T½ as well as a matching reduction in the residual high-spin fraction at room temperatu…
4,4′‐Distyrylazobenzol als Mesogen
1992
4,4′-Distyrylazobenzene as Mesogen From 3,4-dihydroxybenzaldehyde (1) the tetraalkoxy-substituted 4,4′-distyrylazobenzenes (E,E,E)-5a – c are synthesized. A similar reaction sequence leads from ethyl 3,4,5-trihydroxy-benzoate (6) to the hexaalkoxy-substituted 4,4′-distyrylazobenzenes (E,E,E)-11 b, c. With the exception of 5a all products show thermotropic LC properties. Smectic phases have been characterized by polarizing microscopy and by differential scanning calorimetry.
Electrocaloric Effect in (1−x)(0.8Na0.5Bi0.5TiO3-0.2BaTiO3)−xCaTiO3 Solid Solutions at High Electric Fields
2022
This research was funded by the Latvian Science Council Fund, grant number lzp-2020/2-0080. The Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme, grant number 739508.
Cooperative Spin‐Crossover Behaviour in Polymeric 1D Fe II Coordination Compounds: [{Fe(tba) 3 }X 2 ]· n H 2 O
2007
A new family of 1D cooperative spin-crossover polymers with general formula [{Fe(tba)3}X2]·nH2O [tba = N-(4H-1,2,4-triazol-4-yl)benzamide; X = CF3SO3–, n = 2 (1), n = 0 (4); BF4–,n = 3 (2), n = 0 (5); 4-CH3C6H4SO3–, n = 3 (3), n = 0 (6)] has been synthesised and characterised using a series of spectroscopic methods, X-ray powder diffraction, magnetic susceptibility measurements and differential scanning calorimetry. The copper analogue of 1, [{Cu(tba)3}(CF3SO3)2]·3H2O (7), has also been synthesised and its crystal structure solved at 293 K. Compound 7 crystallises in the P space group. The bidentate N-(4H-1,2,4-triazol-4-yl)benzamide ligand bridges the copper ions through the 1,2-nitrogen p…
Sequestering ability of some chelating agents towards methylmercury(II).
2013
A study on the interactions between CH3Hg+ and some S, N and O donor ligands (2-mercaptopropanoic acid (thiolactic acid (H2 TLA)), 3-mercaptopropanoic acid (H2 MPA), 2-mercaptosuccinic acid (thiomalic acid (H3 TMA)), d,l-penicillamine (H2 PSH), l-cysteine (H2 CYS), glutathione (H3 GSH), N,N′-bis(3-aminopropyl)-1-4-diaminobutane (spermine (SPER)), 1,2,3,4,5,6-benzenehexacarboxylic acid (mellitic acid (H6 MLT)) and ethylenediaminetetraacetic acid (H4 EDTA)) is reported. The speciation models in aqueous solution and the possible structures of the complexes formed are discussed on the basis of potentiometric, calorimetric, UV spectrophotometric and electrospray mass spectrometric results. For t…
Selective adsorption of formaldehyde and water vapors in NaY and NaX zeolites
2019
International audience; Coadsorption of formaldehyde and water vapors on NaX and NaY zeolites is studied at 298 K in the pressure range 0-2 hPa by manometry coupled with gas phase chromatography and calorimetry. Coadsorption isotherms, adsorption selectivities and coadsorption heats are measured. Results show that the coadsorption process is selective for water at low filling and for formaldehyde at high filling. The adsorption selectivity for formaldehyde over water is however too low to consider the possibility of using such adsorbents for the development of air handling units. On the other hand, a preliminary study carried out on the adsorption of formaldehyde and water in pure gas phase…
Physico-chemical state influences in vitro release profile of curcumin from pectin beads
2014
International audience; Curcumin is a polyphenolic compound with diverse effects interesting to develop health benefit products but its formulation in functional foods or in food supplement is hampered by its poor water solubility and susceptibility to alkaline conditions, light, oxidation and heat. Encapsulation of curcumin could be a mean to overcome these difficulties. In this paper, curcumin was encapsulated by ionotropic gelation method in low methoxyl pectin beads associated with different surfactants: Solutol®, Transcutol® and sodium caseinate. After encapsulation, physico-chemical properties of encapsulated curcumin such as its solubility, physical state, tautomeric forms and encaps…
Searches for B0 decays to combinations of charmless isoscalar mesons
2004
We search for B meson decays into two-body combinations of eta, eta', omega, and phi mesons from 89 million B B-bar pairs collected with the BaBar detector at the PEP-II asymmetric-energy e+e- collider at SLAC. We find the branching fraction BF(B0 -> eta omega) = (4.0^{+1.3}_{-1.2} +- 0.4) x 10^-6 with a significance of 4.3 sigma. For all the other decay modes we set the following 90% confidence level upper limits on the branching fractions, in units of 10^-6 : BF(B0 -> eta eta)<2.8, BF(B0 -> eta eta')<4.6, BF(B0 -> eta' eta')<10, BF(B0 -> eta'omega)<2.8, BF(B0 -> eta phi)<1.0, BF(B0 -> eta' phi)<4.5, BF(B0 -> phi phi)<1.5.
A microcalorimetric study of the different states of argon and nitrogen adsorbed AT 77 K on silicalite-I and ZSM-5
1992
The adsorption of argon and nitrogen on a series of MFI-type zeolites (silicalite-I (Si/Al>1000) and HZSM-5 (16<Si/Al<120)) was studied by isothermal microcalorimetry, volumetry and neutron diffraction.