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1.
Thyme (Thymus vulgaris) has been known, long time ago, for its aromatic properties. It contains essential oils and polymers such as cellulose (mixture of hemicellulose and cellulose) and lignin. The thyme, studied in this work, was gathered from the same place, in the period from November 1999 to October 2000. The chemical analysis (water, total ash, essential oils, extractive substances, cellulose, holocellulose and lignin) can be used roughly in the characterisation of the four periods that correspond to the four seasons of the year. The cellulose level was found to be more than lignin level in the wet periods (growth of the plant). The opposite was found in the dry periods. The total ash and essential oil levels were found to be high during the period of high pluviometry. The thermal decomposition of cellulose and holocellulose was found to fit well with the first-order kinetics. The activation energy, under air flow, was 185 and 196 kJ mol−1 for cellulose and holocellulose, respectively. The maximum decomposition rate and thermal analysis heating rate of lignin were found to have a direct linear relationship. 相似文献
2.
Kaloustian J. Pauli A. M. Pieroni G. Portugal H. 《Journal of Thermal Analysis and Calorimetry》2002,70(3):959-973
The human urinary calculi are mainly constituted by calcium oxalate, magnesium ammonium phosphate hexahydrate, and uric acid.
The ions or molecules are easily characterized by wet chemical methods. The difficulties appear in the differentiation of
the hydrates of calcium oxalate (monohydrate COM or Whewellite, and dihydrate COD or Weddelite). A high level of COD in the
urinary stones leads, often, inflammation, sharp pain and blood in urine. In the worse cases, they must be extracted by surgical
way. The identification of the main components of urinary calculi, the knowledge of the true number of water molecules bounded
to the calcium oxalate, and the determination of each hydrate in the mixture, are the interests of this memory. The thermal
analysis (simultaneous DTA-TG) was applied on thirty-three urinary calculi. The determination of the calcium oxalate hydrates
was confirmed by calorimetry (DSC).
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
3.
J. Kaloustian 《Journal of Thermal Analysis and Calorimetry》1992,38(6):1377-1389
Nineteen different polymers having no melting endotherm (foam urea-formol, PVC, vinyl polyacetate, vinyl polybutyral, polymethacrylates, polystyrene and its copolymers) are studied by DTA. The identification is realized due to endothermic decomposition peak and exothermic peaks, according to the general method which has been described previously.
Zusammenfassung Mittels DTA wurden neunzehn verschiedene Polymere ohne endothermen Peak beim Schmelzen untersucht (Schaum Carbamid-Formol, PVC, Vinylpolyacetat, Vinylpolybutyral, Polymethacrylate, Polystyrol und seine Kopolymere). Die Identifizierung erfolgte in Übereinstimmung mit der unlängst beschriebenen allgemeinen Methode anhand der endothermen Zersetzung speaks und der exothermen Peaks.相似文献
4.
El Watik L. Claire Y. Zineddine H. Rossi C. Kaloustian J. Sergent M. Périchaud A. 《Journal of Thermal Analysis and Calorimetry》1999,58(1):19-28
The study of the thermal degradation of the fireproof polystyrene—butadiene copolymer by an intumescent system: ammonium polyphosphate (APP)—pentaerythritol (PER)—talc (TAL), was done through an experimental process. Thermogravimetry under air sweeping was used. We observed for the degradation rate of the mixture with fireproofing agents, in the field of 20 to 50% mass loss, a better linear increasing when this mixture contains more TAL and the ratio APP/PER is smaller.
This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
5.
6.
Kaloustian J Pauli A-M Lechene de la Porte P Lafont H Portugal H 《Journal of Thermal Analysis and Calorimetry》2003,71(2):341-351
Cholesterol constitutes the major component of most gallstones. It was identified and determined, in gallstones, issued from
eleven patients, by thermal analysis: differential scanning calorimetry (DSC), with the use of the melting temperature and
enthalpy, thermogravimetry (TG), with the mass loss of water. Anhydrous cholesterol (ChA) was characterized by two endothermic
peaks (polymorphic, melting) and cholesterol monohydrate (ChH) by two endothermic peaks (dehydration, melting), too. Cha needle
and Chh plate crystals were observed under polarizing light microscopy. The numerous stones obtained from nine patients were
cholesterol stones: the ChA was higher 45 and lower 96%. ChH was present in stones of three patients.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
7.
J. Kaloustian Paulette Lechene De La Porte T. El-Moselhy H. Lafont H. Portugal 《Journal of Thermal Analysis and Calorimetry》2005,82(2):331-338
Summary Cholesterol constitutes the major component of most gallstones. It was identified and determined in gallstones by thermal
analysis technique (DSC and TG-DTA), mainly by the use of the melting temperature (Tonset=145°C and Tmax=149°C) and by DTG peak decomposition (Tmax=364°C). Cholesterol anhydrous (ChA), which showed endothermic polymorphic peak, Tmax=40°C, without mass loss, was differentiated from cholesterol monohydrate (ChH), which showed a broad endothermic peak, Tmax=59°C, attributed to loss of water of crystallization (theoretical 4.45%). Morphological studies of gallstones were performed
by optical microscopy and scanning electron microscopy (SEM). The stones consisted of a pigmented core with a variably-sized
irregular central cavity, surrounded by a radially arranged deposits of plate-like ChH. The outer part of the stones showed
ChA crystal arborescences. X-ray microanalysis gave a typical spectrum rich in C and O, and in some instances the presence
of P, which was attributed to the presence of phospholipids. CaCO3 was easily characterized by TG with the use of DTG decomposition peak at 674°C. 相似文献
8.
L. El Watik P. Antonetti Y. Claire H. Zineddine J. Kaloustian C. Rossi A. Perichaud 《Journal of Thermal Analysis and Calorimetry》1998,53(1):297-308
The authors studied the ignifugation and the kinetic of thermal degradation of the Styrene-Butadiene copolymer with an intumescent
system Ammonium polyphosphate-Pentaerythrinol-Melamine. For that, they used the thermogravimetric and oxygen index techniques.
The best formulation of intumescent system which can give the optimum results is proposed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
9.
The treatment of O-alkyllactonium tetrafluoroborate salts with anh. NaSH in CH3CN at 0°C led to five-, six-, and seven-membered thionolactones (44– 90% yield). 相似文献
10.
Paolini J Tomi P Bernardini AF Bradesi P Casanova J Kaloustian J 《Natural product research》2008,22(14):1270-1278
The composition of the essential oil of Cistus albidus (L.) obtained from plants growing wild in Provence (France) has been investigated using GC-RI (RI = retention indices), GC/MS and (13)C-NMR. Eighty-eight components were reported accounting for 81.8% of the essential oil. This essential oil was characterized by a high content of sesquiterpenes with alpha-zingiberene (12.8%), alpha-curcumene (7.7%), (E)-beta-caryophyllene (5.9%), alpha-cadinol (5.4%), alpha-bisabolol (4.1%), caryophyllene oxide (3.8%), allo-aromadendrene (3.4%), delta-cadinene (3.4%), and germacrene D (3.1%) being the main components. 相似文献