scholarly journals The preparation of Al2O3-Na2SO4 composites derived from local kaolin through an alkaline destruction combined with sulphatization method

2021 ◽  
Vol 882 (1) ◽  
pp. 012026
Author(s):  
E Maryani ◽  
N Sofiyaningsih ◽  
R Septawendar
Keyword(s):  
Chemical Composition ◽  
Ir Spectra ◽  
Solid Electrolyte ◽  
Thermal Behaviour ◽  
Initial Study ◽  
Vibration Modes ◽  
Alumina Surface ◽  
Mineral Phases ◽  
Ft Ir

Abstract Composites of Na2SO4 is promising for solid electrolyte application. In this initial study, composites of Al2O3/Na2SO4 were successfully synthesized from local kaolin through an alkaline destruction method combined with sulphatization. The composites were characterized including thermal behaviour, mineral phases, chemical composition, FT-IR spectra, and microstructures. The composites consist of a-Al2O3 and Na2SO4 phases after calcination at 1300 °C. This phenomenon is confirmed by the XRF and FT-IR result. The composite consists of Al2O3 and Na2SO4 as major components, accounting 41.98% and 47.09% of the total, respectively. Meanwhile, SiO2 is found as the impurity, accounting 2.86% of the total. The vibration modes of Al-O bonds are detected at 995.27 and 524.46 cm1, whereas the SO4 bands appear at 1111.00 and 617.22 cm1. Na2SO4 exhibits a rod-like particle that cover the alumina surface in the morphology.

scholarly journals Influence of growth conditions on hydrophobicity ofLactobacillus acidophilusandBifidobacterium lactiscells and characteristics by FT-IR spectra

2010 ◽  
Vol 24 (3-4) ◽  
pp. 251-255 ◽  
Author(s):  
Laisana Shakirova ◽  
Lilija Auzina ◽  
Peteris Zikmanis ◽  
Marita Gavare ◽  
Mara Grube
Keyword(s):  
Chemical Composition ◽  
Ir Spectra ◽  
Physiological State ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Growth Conditions ◽  
Probiotic Properties ◽  
Elevated Protein ◽  
Ft Ir ◽  
Quantitative Analyses

In this study we have found, that the values of cell surface hydrophobicity (CSH) ofL. acidophilusLA5 andB. lactisBb12 cells change in response to varied growth conditions – phase of growth, concentration or type of carbon source, presence of oxygen. An evaluation of FT-IR spectra using cluster and quantitative analyses revealed substantial changes of the chemical composition depending on the CSH level ofL. acidophilusLA5 andB. lactisBb12 cells. Decrease of the carbohydrate level was observed in proportion to the increased CSH values alongside with the elevated protein content of more hydrophobic cells of both cultures. The results of present study could help to specify the appropriate physiological state and environment forL. acidophilusLA5 andB. lactisBb12 to ensure their probiotic properties.

Fabrication of Chelate-Setting Cement Using Silicon-Substituted Hydroxyapatite and its Property

2011 ◽  
Vol 493-494 ◽  
pp. 370-374 ◽  
Author(s):  
Y. Nakashima ◽  
Michiyo Honda ◽  
Toshiisa Konishi ◽  
Minori Mizumoto ◽  
Mamoru Aizawa
Keyword(s):  
Mechanical Property ◽  
Compressive Strength ◽  
Surface Modification ◽  
Chemical Composition ◽  
Ir Spectra ◽  
High Dose ◽  
Precipitation Reaction ◽  
Ft Ir ◽  
Xrd Patterns ◽  
Surface Modified

We have developed novel hydroxyapatite (HAp) cement, “chelate-setting HAp cement” on the basis of chelate bonding of inositol hexaphosphate (IP6). In order to create the cement with enhanced bioactivity, we used a silicon-substituted hydroxyapatite (Si-HAp) as a starting material instead of pure HAp powder. The Si-HAp powders were prepared via an aqueous precipitation reaction and surface-modified with IP6 (IP6-Si-HAp). The Si-HAp were synthesized with desired Si contents (0, 0.4, 0.8, 1.6, and 2.4 mass%). Regardless of the amount of Si, the XRD patterns and FT-IR spectra of the powders were similar to each other. Additionally, chemical composition of Si-HAp powders were the almost same as the nominal one. The substitution of Si resulted in a decrease in the a-axis and increase in the c-axis of unit cell of HAp. While, the compressive strength of IP6-Si-HAp cements was higher than that of Si-HAp cements. These results suggest that surface-modification of any powders with IP6 is effective for enhancement of mechanical property. Comparison of mechanical property between HAp and Si-HAp cement specimens revealed that the substitution of lower levels of Si into0 HAp lattice did not greatly influence compressive strength. However, the substitution of high dose of Si (over 2.4 mass%) reduced the compressive strength. Therefore, to fabricate the chelate-setting cements with enhanced bioactivity, it is necessary to control the amount of Si.

scholarly journals Chemical Composition and FT-IR Spectra of Sugar Palm (Arenga pinnata) Fibers Obtained from Different Heights

2013 ◽  
Vol 10 (2) ◽  
pp. 83-97 ◽  
Author(s):  
M.R. Ishak ◽  
Z. Leman ◽  
S.M. Sapuan ◽  
M.Z.A. Rahman ◽  
U.M. K. Anwar
Keyword(s):  
Chemical Composition ◽  
Ir Spectra ◽  
Ft Ir

Changes in chemical composition of decayed Scots pine and beech wood

2014 ◽  
Vol 21 (4) ◽  
pp. 589-595 ◽  
Author(s):  
Eylem Dizman Tomak
Keyword(s):  
Chemical Composition ◽  
Ir Spectra ◽  
Scots Pine ◽  
Degradation Mechanism ◽  
Beech Wood ◽  
Accelerated Aging ◽  
Brown Rot ◽  
Brown Rot Fungi ◽  
Decay Test ◽  
Ft Ir

AbstractIn this study, changes in chemical composition of aged and unaged Scots pine and beech wood decayed by brown-rot fungi Coniophora puteana and Poria placenta were presented by Fourier transform infrared (FT-IR) spectra. Samples were exposed to six complete cycles of accelerated aging for 12 days and then subjected to brown-rot fungi attack for 8 weeks. Weight loss of samples was found to be 25–46% depending on wood and fungi species and being aged ones. Accelerated aging treatments seemed to have a slight role on chemical composition of Scots pine and beech samples while they increased biodegradation of samples. FT-IR spectra showed degradation of wood carbohydrates revealed by reduction of the peaks responsible for hemicellulose and cellulose at 1730, 1370, 1150, and 897 cm-1 in pine and 1730, 1370, 1027, and 897 cm-1 in beech. Stronger lignin peaks at 1650, 1593, 1506, 1455, 1422, 1261, and 1230 cm-1 in pine and 1650, 1506, 1455, and 1422 cm-1 in beech were obtained after decay test. FT-IR spectra of samples were consistent with the degradation mechanism of brown-rot fungi. In general, changes in the carbohydrate and lignin peaks were greater in samples exposed to accelerated aging treatments for both wood species.

FT-IR spectra of Li(AlxCo1-x)O2 (x=0.1-0.5)

2001 ◽  
Vol 699 ◽  
Author(s):  
W. Hao ◽  
C. Li ◽  
X. Meng ◽  
G. Chen ◽  
W. Xu
Keyword(s):  
Ir Spectra ◽  
The Other ◽  
Vibration Modes ◽  
Ft Ir ◽  
Two Peaks ◽  
Relative Change

AbstractFT-IR spectra from Li(AlxCo1-x)O2 (x=0.1-0.5) are reported. It was found out that there are four peaks located at 556cm−1, 601cm−1, 1438cm−1, 1498cm−1. First two peaks at 556cm−1 and 601cm−1 can be assigned to A2u and Eu vibration modes, respectively. The other two new peaks at 1438cm−1 and 1498cm−1 can not be explained clearly. With the increasing of Al concentration, all peaks position remain unchanged. However a relative change in the intensity of A2u and Eu peaks was observed.

Light- or Dark-Colored, L-DOPA-Based Melanins

2018 ◽  
Author(s):  
Koen Vercruysse ◽  
Margaret M. Whalen
Keyword(s):  
Human Physiology ◽  
Ir Spectra ◽  
Immune Cells ◽  
Chemical Properties ◽  
Chemical Signature ◽  
Ft Ir

<p>This report is a continuation of previous research on the H<sub>2</sub>O<sub>2</sub>-mediated synthesis of melanin-like pigments. We synthesized and characterized L-DOPA-based pigments using air- or H<sub>2</sub>O<sub>2</sub>-mediated<sub> </sub>oxidation. We compared their physic-chemical properties and evaluated their capacity to affect the interleukin release from immune cells. The use of higher concentrations of H<sub>2</sub>O<sub>2</sub> resulted in melanin-like materials with a distinct chemical signature in their FT-IR spectra and a lighter color. All pigments enhanced the interleukin release from immune cells. The possibility that lighter-colored melanins can be generated is discussed in the context of the importance of melanin-based pigmentation in human physiology.</p>

Thermal Behaviour of Candesartan Active substance and in pharmaceutical compounds

2017 ◽  
Vol 68 (8) ◽  
pp. 1895-1902
Author(s):  
Ioana Cristina Tita ◽  
Eleonora Marian ◽  
Bogdan Tita ◽  
Claudia Crina Toma ◽  
Laura Vicas
Keyword(s):  
Thermal Behaviour ◽  
Active Substance ◽  
Pharmaceutical Research ◽  
Pharmaceutical Product ◽  
Nitrogen Atmosphere ◽  
Pure Substance ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ft Ir

Thermal analysis is one of the most frequently used instrumental techniques in the pharmaceutical research, for the thermal characterization of different materials from solids to semi-solids, which are of pharmaceutical relevance. In this paper, simultaneous thermogravimetry/derivative thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC) were used for characterization of the thermal behaviour of candesartan cilexetil � active substance (C-AS) under dynamic nitrogen atmosphere and nonisothermal conditions, in comparison with pharmaceutical product containing the corresponding active substance. It was observed that the commercial samples showed a different thermal profile than the standard sample, caused by the presence of excipients in the pharmaceutical product and to possible interaction of these with the active substance. The Fourier transformed infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRPD) were used as complementary techniques adequately implement and assist in interpretation of the thermal results. The main conclusion of this comparative study was that the TG/DTG and DSC curves, together with the FT-IR spectra, respectively X-ray difractograms constitute believe data for the discrimination between the pure substance and pharmaceutical forms.

scholarly journals Spectroscopy as a useful tool for the identification of changes with time in post-mortem vitreous humor for forensic toxicology purposes

2021 ◽  
Author(s):  
Anna Wójtowicz ◽  
Agata Mitura ◽  
Renata Wietecha-Posłuszny ◽  
Rafał Kurczab ◽  
Marcin Zawadzki
Keyword(s):  
Ir Spectra ◽  
Forensic Toxicology ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
Vitreous Humor ◽  
Attenuated Total Reflection ◽  
Glass Slides ◽  
Added Benefit ◽  
Ft Ir ◽  
Non Destructive

AbstractVitreous humor (VH) is an alternative biological matrix with a great advantage of longer availability for analysis due to the lack of many enzymes. The use of VH in forensic toxicology may have an added benefit, however, this application requires rapid, simple, non-destructive, and relatively portable analytical analysis methods. These requirements may be met by Fourier transform infrared spectroscopy technique (FT-IR) equipped with attenuated total reflection accessory (ATR). FT-IR spectra of vitreous humor samples, deposited on glass slides, were collected and subsequent chemometric data analysis by means of Hierarchical Cluster Analysis and Principal Component Analysis was conducted. Differences between animal and human VH samples and human VH samples stored for diverse periods of time were detected. A kinetic study of changes in the VH composition up to 2 weeks showed the distinction of FT-IR spectra collected on the 1st and 14th day of storage. In addition, data obtained for the most recent human vitreous humor samples—collected 3 and 2 years before the study, presented successful discrimination of all time points studied. The method introduced was unable to detect mephedrone addition to VH in the concentration of 10 µg/cm3. Graphic abstract

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