2D FT-IR spectroscopy analysis of the pressure-induced changes in proteins

1999 ◽  
Vol 19 (2) ◽  
pp. 375-378 ◽  
Author(s):  
L Smeller ◽  
K Heremans
Keyword(s):  
Ir Spectroscopy ◽  
Spectroscopy Analysis ◽  
Ft Ir ◽  
Induced Changes ◽  
Ft Ir Spectroscopy

scholarly journals SINTESIS SURFAKTAN ALKIL POLIGLIKOSIDA DARI GLUKOSA DAN DODEKANOL DENGAN KATALIS ASAM

2012 ◽  
Vol 1 (1) ◽  
pp. 5-9
Author(s):  
Anastasia Wulan Pratidina Swasono ◽  
Putri Dei Elvarosa Sianturi ◽  
Zuhrina Masyithah
Keyword(s):  
Surface Tension ◽  
Hydrochloric Acid ◽  
Ir Spectroscopy ◽  
Critical Micelle Concentration ◽  
Fatty Alcohol ◽  
Catalyst Concentration ◽  
Molar Ratio ◽  
Spectroscopy Analysis ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Alkyl polyglicoside (APG) is an enviromentally friendly product  non-ionic surfactact and  biodegradable product that can be obtained by reacting glucose and fatty alcohol. The purpose of this study was to know the manufacture of surfactant alkyl polyglicoside by using glucose and dodecanol, and also to know the effect of catalyst concentration and molar ratio glucose  and dodecanol: 1:1; 1:2: 2:1 (mol/mol), catalyst consentration of hydrochloric acid: 0.3 M; 0,4 M; 0,5 M; 0,6 M at temperature 100 0C. The analysis in this research using FT-IR spectroscopy, analysis of surface tension (Critical Micelle Concentration) and HLB values ​​(Hidrophylic-Lipophylic Balance). The best catalyst concentration at synthesis of alkyl polyglicoside is 0.6 M, the largest surface tension (CMC) at ratio glucose and dodecanol 2:1 is 70.7945% and the highest HLB value is 7.31 in comparison of glucose and dodecanol 2:1.

scholarly journals Fourier-transform infrared (FT-IR) spectroscopy analysis discriminates asymptomatic and symptomatic Norway spruce trees

Plant Science ◽  
2019 ◽  
Vol 289 ◽  
pp. 110247
Author(s):  
Mukrimin Mukrimin ◽  
Anna O. Conrad ◽  
Andriy Kovalchuk ◽  
Riitta Julkunen-Tiitto ◽  
Pierluigi Bonello ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Ir Spectroscopy ◽  
Norway Spruce ◽  
Fourier Transform Infrared ◽  
Spectroscopy Analysis ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

scholarly journals Electrospun Nickel Manganite (NiMn2O4) Nanocrystalline Fibers for Humidity and Temperature Sensing

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4357
Author(s):  
Milena P. Dojcinovic ◽  
Zorka Z. Vasiljevic ◽  
Jugoslav B. Krstic ◽  
Jelena D. Vujancevic ◽  
Smilja Markovic ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
Material Constant ◽  
Temperature Sensing ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
Bet Specific Surface Area ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Nickel manganite nanocrystalline fibers were obtained by electrospinning and subsequent calcination at 400 °C. As-spun fibers were characterized by TG/DTA, Scanning Electron Microscopy and FT-IR spectroscopy analysis. X-ray diffraction and FT-IR spectroscopy analysis confirmed the formation of nickel manganite with a cubic spinel structure, while N2 physisorption at 77 K enabled determination of the BET specific surface area as 25.3 m2/g and (BJH) mesopore volume as 21.5 m2/g. The material constant (B) of the nanocrystalline nickel manganite fibers applied by drop-casting on test interdigitated electrodes on alumina substrate, dried at room temperature, was determined as 4379 K in the 20–50 °C temperature range and a temperature sensitivity of −4.95%/K at room temperature (25 °C). The change of impedance with relative humidity was monitored at 25 and 50 °C for a relative humidity (RH) change of 40 to 90% in the 42 Hzπ1 MHz frequency range. At 100 Hz and 25 °C, the sensitivity of 327.36 ± 80.12 kΩ/%RH was determined, showing that nickel manganite obtained by electrospinning has potential as a multifunctional material for combined humidity and temperature sensing.

Molecular detection of HPV and FT-IR spectroscopy analysis in women with normal cervical cytology

2020 ◽  
Vol 29 ◽  
pp. 101592
Author(s):  
Magda Rogéria Pereira Viana ◽  
Igor Martins Alves Melo ◽  
Breno Pupin ◽  
Leandro José Raniero ◽  
Renata de Azevedo Canevari
Keyword(s):  
Ir Spectroscopy ◽  
Molecular Detection ◽  
Cervical Cytology ◽  
Spectroscopy Analysis ◽  
Ft Ir ◽  
Normal Cervical Cytology ◽  
Ft Ir Spectroscopy

Heat-Induced Changes in the Photochemical Centres and the Protein Secondary Structures of Photosystem II Studied by Variable Fluorescence and Difference FT-IR Spectroscopy

1999 ◽  
Vol 54 (1-2) ◽  
pp. 35-43 ◽  
Author(s):  
M. Joshi ◽  
M. Fragata
Keyword(s):  
Ir Spectroscopy ◽  
Photosystem Ii ◽  
Structure Function ◽  
Secondary Structures ◽  
Variable Fluorescence ◽  
Photosynthetic Membrane ◽  
Ft Ir ◽  
Α Helix ◽  
Induced Changes ◽  
Ft Ir Spectroscopy

Variable fluorescence (Fv), i.e., Fv = Fm - F0 where F0 is the minimal fluorescence and Fm the maximum fluorescence, and difference Fourier transform infrared (FT-IR) spectroscopy were used to study the effect of heat stress in the 25-55 °C range on photosystem II (PSII) structure and function. First, the Fv intensity reflects accurately the changes in the number of open photochemical centers in PSII. Secondly, the use of Fv in combination with FT-IR spectroscopy can disclose structure-function correlations in the heat inactivation of the PSII complex. Analysis of the midpoint temperatures of thermal denaturation, i.e., 50% inactivation, reported so far in investigations of the thylakoid membrane components has revealed that most of the thermal transitions attributed to PSII are in the 39 -46 °C range. In this work, it is shown specifically that the midpoint temperature of PSII inactivation is at about 40 °C. Moreover, it was clearly demonstrated that the heat-induced changes above 40 °C are the result of a marked decrease in the number of open photochemical centers in PSII. It was also seen that above this same temperature the loss of photochemical centers has its structural counterpart in overall modifications of the secondary structures of the PSII proteins resulting from the decrease in the α-helix content concomitant with the increase in extended chain (β-strand) conformations. In brief, a novel finding reported here is that the number of open photochemical centers in PSII is dependent on a dynamic equilibrium between the contents of the PSII proteins in α-helix and extended chains (β-strands), but not in β-sheets and β-turn structures except for the antiparallel-β-sheet conformations. This therefore associates the thermal inactivation of the photochemical centers in photosystem II with distinct conformational changes in the proteins of the PSII supramolecular complex. In the particular context of the present study, these findings constitute a significant contribution to the investigation of structure-function correlations in the photosynthetic membrane. In a broader context, this information might be essential for the comprehension of the molecular arrangements or local structure order that are involved directly or indirectly in biological catalysis

scholarly journals Synthesis of Polyurethane from Diphenyl Methane 4,4 Diisocyanate (Mdi) Polymerization with Hydroxilated Avocado Oil Polyol

2019 ◽  
Vol 1 (1) ◽  
pp. 19-30
Author(s):  
Herlince Sihotang
Keyword(s):  
Ir Spectroscopy ◽  
Mixing Ratio ◽  
Spectroscopy Analysis ◽  
Gel Content ◽  
Avocado Oil ◽  
Ft Ir ◽  
Oil Source ◽  
Structure Confirmation ◽  
Ft Ir Spectroscopy

Polymerization between polyol and isocyanate compounds produces polyurethane in different forms. Polyol used in this study utilized spoiled avocado as the oil source for polyol to produce polyurethane. Avocado oil was epoxidized with formic acid (HCOOH) and H2SO4 catalyst at 40 – 45oC followed by hydrolysis reaction to produce polyol reaction. Next polyol was purified and structure confirmation was done using FT-IR spectroscopy analysis. Polyol was then reacted with diphenylmethane 4,4 diisocyanate (MDI) with ratios of (polyol : MDI) 9:1; 8:2; 7:3; 6:4; and 5:5 (v/v) in a total volume of 10 mL with open air stirring at 40 – 45oC to produce polyurethane. Characterization for the form was observed visually followed by the determination of gel content, density and structure using FT-IR spectroscopy. The results of polyol from avocado oil reacted with diphenylmethane 4,4 diisocyanate for each of the mixing ratio to produce polyurethane is gel content of 74.63% to 99.80% where the higher MDI ratio is, the higher gel content becomes. Density determination from the polyurethane produced is between 0.1341 g/cm3 to 0.7220 g/cm3. FT-IR spectrometer analysis to polyurethane produced is marked with the peaks at 3400 – 3300 cm-1, 2270 – 1940 cm-1, 1700-1600 cm-1 and 1590 – 1540 cm-1 wavelengths which are the characteristic of urethane functional groups.

scholarly journals Synthesis of Carboxymethyltricellulose and Its Adsorption Towards Cu2+ Ions

2019 ◽  
Vol 1 (2) ◽  
pp. 1-10
Author(s):  
Adil Ginting
Keyword(s):  
Ir Spectroscopy ◽  
Surface Area ◽  
Trichloroacetic Acid ◽  
Morphological Analysis ◽  
Spectroscopy Analysis ◽  
Atomic Adsorption ◽  
Ft Ir ◽  
Adsorption Capability ◽  
Ft Ir Spectroscopy

Cellulose was isolated from plantain skin and then carboxymethylated with trichloroacetic acid which resulted a 0.9936 gram of carboxymethylcellulose. The FT-IR spectroscopy analysis of carboxymethyltricellulose indicated the –OH vibration at wavelength of 3448.72 cm-1.Moreover, a wavenumber in the region of 1026.13 cm-1 is attributed to ether vibration (-O-) and carboxyl vibration at 1651.07 cm-1. The results of morphological analysis using SEM also showed a smoother, homogeneous pore, and a larger surface area. The adsorption capability for Cu2+ ions at concentration of 100 ppm was analyzed by atomic adsorption spectrophotometer (AAS). It shows that the optimum adsorption was found to be at a 90 minutes agitation process for both carboxymethyltricellulose and cellulose with about 97.266% and 21.602% respectively.

scholarly journals Sintesis Cmc-G-Epiklorohidrin/Etilendiamina Melalui Reaksi Selulosa Membentuk Cmc Dilanjutkan Dengan Esterifikasi/Aminasi Menggunakan Epiklorohidrin/Etilendiamina

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Adil Ginting ◽  
Mimpin Ginting ◽  
Hotlan Heber Situmeang
Keyword(s):  
Ir Spectroscopy ◽  
Carboxymethyl Cellulose ◽  
Morphological Analysis ◽  
Sodium Carboxymethyl Cellulose ◽  
Second Step ◽  
Paper Pulp ◽  
Spectroscopy Analysis ◽  
Amination Reaction ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Cellulose from paper pulp was alkalized with NaOH 30%; then carboxymethylated with monochloroacetic acid producing carboxymethyl cellulose (CMC). CMC resins was subsequently alkalized again with NaOH 30% producing sodium carboxymethyl cellulose (Na-CMC) before esterification/amination reaction with epichlorohydrin/ethylendiamine. Esterification/amination reaction with epichlorohidrin/ethylendiamine was carried out in two steps as well. Na-CMC was reacted with epichlorohydrin, and in the second step, 2-oxiranylmethyl carboxymethyl cellulose was reacted with ethylendiamine producing cellulose-g-epichlorohydrin/ethylendiamine. FT-IR spectroscopy analysis indicated CN Amine vibration in the region 1417 cm-1 and in the 1600 cm-1 region attributed to vibration of C=O group. Morphological analysis using SEM showed homogeneous and porous at their structure. 

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