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Coll R. Saurina J. Escoda L. Suñol J. J. 《Journal of Thermal Analysis and Calorimetry》2018,131(2):1277-1286
Journal of Thermal Analysis and Calorimetry - This paper reports the effects of welan gum on the hydration and hardening behaviors of Portland cement (PC) by using X-ray diffractometry, mercury... 相似文献
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R. Coll L. Escoda J. Saurina J. L. Sánchez-Llamazares B. Hernando J. J. Suñol 《Journal of Thermal Analysis and Calorimetry》2010,99(3):905-909
Three magnetic shape memory alloys: Mn50Ni50−x
Sn
x
(x = 5, 7.5, and 10) were produced as bulk polycrystalline ingots by arc melting. The structural austenite–martensite transformation
was checked by calorimetry. The transformation temperatures decrease as increasing the Sn content. The same trend is found
in the entropy and enthalpy changes related to the transformation. The control of the valence electron by atom e/a determines the transformation temperatures range in this kind of alloys and it is possible to develop alloys that can be
candidates in applications as sensors and actuators. Furthermore, X-ray diffraction was performed to check the crystalline
structure at room temperature. 相似文献
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Samples resulting from reaction of TiO2 with octyltriethoxysilane, developed using a supercritical carbon dioxide procedure, have been studied by infrared and Raman spectroscopies and thermogravimetric analysis. Different reaction conditions have been applied to the preparation of samples in order to study the influence of experimental factors on the sample properties. Vibrational techniques have first been used to verify the presence of silanized structures on the surface of TiO2 through the detection of specific bands characteristic of the Si-O-Si cross-linking. Thermogravimetric profiles consisting of weight loss values as a function of temperature have been analyzed by principal component analysis to extract information about the characteristics of the linkage between silane and TiO2 as well as the thermal stability of the prepared materials. The mathematical treatment of data has provided conclusions on the properties of the samples and analogies and differences with respect to the commercial material. 相似文献
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In this paper, we propose the construction of merging arrangements for combining the information from various runs as a powerful approach to improve the resolution. The bacteriorhodopsin (bR) photocycle has been chosen in this study as an example dealing with the protein dynamics monitored by means of time-resolved step-scan FT-IR spectroscopy. The possibilities of matrix merging are evaluated and results are compared with those from the analysis of individual and augmented matrices. As a conclusion, this strategy provides excellent results for the analysis of this type of time-resolved FT-IR data. 相似文献
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HDPE based composites were produced with 10-20-30 and 40% composite mass of wood fiber. The coupling agents were epolene and
silane. The thermal behavior of composite samples was analyzed as a function of the coupling agent content, the exposure time
and the wood fibers content by means of differential scanning calorimetry. Calorimetric curves of all samples of first and
second heating shows a similar behavior. Some significant relation has been observed between the exposure time and the degree
of crystallinity for the same percentage of fiber samples. A linear relation between the melting enthalpy average vs. content
in cellulosic fibers is detected. Nevertheless, the fibers non-pretreated with coupling agent show a lower loss of crystallinity
of the HDPE matrix at low wood fiber content (10%). A slight diminution of the melting peak temperature is detected as increasing
the exposure time.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Suńol J. J. Saurina J. Carrillo F. Colom X. 《Journal of Thermal Analysis and Calorimetry》2003,72(2):753-758
Comparison of Lyocell, modal and viscose fibers was performed by means of differential scanning calorimetry, thermogravimetry
and scanning electron microscopy. Thermal analysis was performed in air atmosphere. Samples were mercerized (21.3 g 100 mL-1)
or submitted to solar radiation (seven months). Solar degraded samples presents a higher thermal stability and are initially
less degraded. Furthermore, Lyocell fiber is the most stable under thermal degradation conditions. Heating produces a reduction
of the fiber diameter (about 50%).
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Sentellas S Saurina J Hernández-Cassou S Galceran MT Puignou L 《Journal of chromatography. A》2001,909(2):259-269
Capillary zone electrophoresis with diode-array detection was applied to the separation of ebrotidine and its metabolites. However, three of these, which are neutral in the conditions studied, co-migrated with the electroosmotic flow signal. Therefore, strongly overlapping peaks were observed. The main aim of this study was to show the potentiality of capillary electrophoresis in combination with chemometrics. Multivariate calibration methods were applied to quantify these analytes in synthetic mixtures. The results obtained using partial least squares (PLS) were in agreement with actual values, with an overall prediction error of 9.7%. 相似文献
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Various types of glycosaminoglycans (GAGs) including heparins, chondroitin sulfates, dermatan sulfate and hyaluronic acid were studied from their proton nuclear magnetic resonance (1H NMR) spectra using chemometric techniques. Despite the complexity of the 1H NMR signals, data analysis using principal component analysis enabled the different GAG classes to be distinguished and permitted their classification according to their chemical structure. The analysis of the composition of the major disaccharide unit and other relevant chemical structures in the heparin samples was performed using partial least squares regression. 相似文献