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Search Results: 1 - 10 of 1368 matches for " FT-IR "
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FT-IR Microspectroscopic Imaging of Cross-Sectioned Human Hair during a Bleaching Process  [PDF]
Soo Ryeon Ryu, Wonhyeong Jang, Si-In Yu, Byeong-Ha Lee, Oh-Sun Kwon, Kwanwoo Shin
Journal of Cosmetics, Dermatological Sciences and Applications (JCDSA) , 2016, DOI: 10.4236/jcdsa.2016.65023
Abstract: We investigated bleached human hair by FT-IR microspectroscopy and chemical imaging. The cross sectioned hair is approximately 90 μm in diameter, showed cuticle and cortex in chemical imaging. Differential amide I/II absorbance ratio and broadening amide I band between in the cortex and cuticle were confirmed in FT-IR microspectroscopy and chemical imaging. The cystine monoxide band from the products of disulfide oxidation of the amino acid cystine is associated with hair damaging during bleaching process. With increase bleaching time, the band for cystine monoxide shows more intense and larger area in chemical image. The spatially chemical change was investigated in detail by FT-IR microspectroscopy and chemical imaging during the bleached process.
Microwave Assisted Synthesis and Evaluation of Cross-Linked Carboxymethylated Sago Starch as Superdisintegrant  [PDF]
Akhilesh V. Singh, Lila K. Nath, Manisha Guha, Rakesh Kumar
Pharmacology & Pharmacy (PP) , 2011, DOI: 10.4236/pp.2011.21005
Abstract: The aim of this study was to modify the sago starch and evaluate its efficacy as tablet disintegrant. Cross-linked car-boxymethylated sago starch (CMSS) was synthesized using native sago starch (SS) and monochloroacetic acid (MCA) with sodium hydroxide in microwave radiation environment. FT-IR analysis of the sample confirmed the carboxy-methylation by showing absorption peak at 1607.2 cm-1. CMSS with degree of substitution (DS) of 0.31 was formed and, it was further evaluated as disintegrant in Ondasetron based tablets. The results revealed that CMSS could be used as disintegrant in tablet formulation in concentration dependant manner.
Defluoridation of Water by a Biomass: Tinospora cordifolia  [PDF]
Piyush Kant Pandey, Madhurima Pandey, Rekha Sharma
Journal of Environmental Protection (JEP) , 2012, DOI: 10.4236/jep.2012.37074
Abstract: This research is focused on the search of a biomass for the sequestration of fluoride from drinking water. Defluoridation of water was studied by batch experiments in biosorption process. The biomass was found to reduce fluoride to permissible limit 1.5 mg/L as prescribed by WHO. The efficiency of the sorption process was investigated under different experimental parameters such as pH 7, standing time 120 min and biomass doses 7.0 g with 5 mg/L concentration of fluoride. Neutral pH was identified as the optimum condition of the medium and 120 minutes was the best contact time for maximum fluoride adsorption. The experimental data was found good fitting to Langmuir and Freundlich isotherm models. In interference study tolerable effect was found with 50 mg/L concentration of co-ions, whereas increasing the concentration of co-ions retarded the fluoride removal capacity in some extent. FT-IR spectrum analysis showed fluoride binding in the different frequency ranges of the biomass. Eventually, this plant biomass is recommended as a suitable and low cost adsorbent to reduce fluoride into standard permissible limit.
Spectral properties of LH2 exhibit very similar even when heterologously express LH2 with β-subunit fusion protein in Rhodobacter sphaeroides  [PDF]
Zhiping Zhao, Xin Nie, Zongli Hu, Guoping Chen, Zaixin Li, Zhi Zhang
Advances in Biological Chemistry (ABC) , 2013, DOI: 10.4236/abc.2013.31013
Abstract:

Interactions between the light-harvesting subunits and the non-covalently bound photopigments attribute considerably to the spectral properties of photosynthetic bacteria light-harvesting complexes. In our previous studies, we have constructed a novel Rhodobacter sphaeroides expression system. In the present study, we focus on the spectral properties of LH2 when heterologously express LH2 with β-subunit- GFP fusion protein in Rb. sphaeroides. Near infra-red spectrum of LH2 remained nearly unchanged as measured by spectroscopy. Fluorescence spectrum suggested that the LH2 with β-subunit-GFP fusion protein complexes still possessed normal activity in energy transfer. However, photopigments contents were significantly decreased to a very low level in the LH2 with β-subunit-GFP fusion protein complexes compared to that of LH2. FT-IR spectra indicated that interactions between photopigments and LH2 α/β- subunits appeared not to be changed. It was concluded that the LH2 spectral properties exhibited very similar even when heterologously expressed LH2 b-subunit fusion protein in Rb. sphaeroides. Our present study may supply a new insight into better understand the interactions between light-harvesting subunits and photopigments and bacterial photosynthesis and promote the development of the novel Rb. sphaeroides expression system.

Role of Infrared Spectroscopy in Coal Analysis—An Investigation  [PDF]
Manoj Balachandran
American Journal of Analytical Chemistry (AJAC) , 2014, DOI: 10.4236/ajac.2014.56044
Abstract: Fourier transform infrared (FT-IR) spectroscopy is a widely used analytical technique for determining the different functional groups of a coal structure. This method, being able to reveal carbo-hydrogenated structures (aromatic and aliphatic) and heteroatomic functions (mainly oxygenated), as well as to detect the presence of minerals, is currently one of the most powerful techniques for coal characterization and thus is of paramount importance in the various utilization procedures of coal (industrial combustion, coke production processes, etc.). FT-IR study shows the presence of aliphatic -CH, -CH2 and -CH3 groups, aliphatic C-O-C stretching associated with -OH and -NH stretching vibrations and HCC rocking. It is conjectured that, the two-stage leaching using HNO3 followed by HF remarkably reduced the ash content as well as the minerals including Al, Si and Ca. The solubilization of samples with buffered EDTA could not eliminate the minerals in coal. The silicate and kaolinite bands showed a systematic lowering on EDTA and carboxylic acid treatment. The fungal leaching was most beneficial for aromatic molecules with different degrees of substitution. The intensity of bands due to carbonyl groups was increased, when treated with fungi, whereas that due to oxygen functional groups showed a reverse trend. The mineral bands due to silicates also decreased in intensity, on post treatment with fungal culture.
Thermal and FT-IR Properties of Semiconducting SnO2-PbO-V2O5 Glass System  [PDF]
Ponnada Tejeswara Rao, Balireddy Vasundhara
New Journal of Glass and Ceramics (NJGC) , 2015, DOI: 10.4236/njgc.2015.53007
Abstract: Melt quenched “SnO2(50-x)PbO:50V2O5” glass system containing x = 5, 10, 15 in molar ratio has been investigated. Effects of heating rate, glass transition, crystallization, melting temperature and infrared spectra of SnO2 substituted PbO-V2O5 glass system are reported. XRD results show that perfect vitrification has been achieved for all the glass samples after annealing at 150°C. DSC results have indicated that eutectic composition of the lead metavanadate has been maintained for all the glass systems up to 15 mole% of substitution. IR spectra for a SnO2 substitution of 5 mole% V=O stretching frequency occur at 966 cm-1 without appearance of any additional peak. But for 10 mole% and 15 mole% SnO2 substituted samples, additional peaks appear at 1023 and 1005 cm-1 indicating the effect of SnO2 in the vanadate crystalline matrix such that there is an elongation of V=O bond. Since the crystalline matrix is affected, we can expect similar effect in the glass matrix also.
A Novel Enzymatic Method for Preparation and Characterization of Collagen Film from Swim Bladder of Fish Rohu (Labeo rohita)  [PDF]
Ramasamy Sripriya, Ramadhar Kumar
Food and Nutrition Sciences (FNS) , 2015, DOI: 10.4236/fns.2015.615151
Abstract: A novel enzymatic method for extraction and preparation of fish collagen from swim bladder revealed the occurrence of α, β and γ bands with approximately 12.1 g/100g collagen corresponding to 89% of collagen and thus confirmed the nativity and purity of the fish collagen. FT-IR studies confirmed the retention of all three amide bands of I, II and III, and triple helixcity. UN-crosslinked and UV-crosslinked fish collagen membrane records a very high temperature of helix denaturation at 197℃ and 215℃, shrinkage temperature at 50℃ ± 3.2℃ and 62℃ ± 2.7℃ and tensile strength at 16.89 ± 2.5 and 120.02 ± 1.0 Kg/cm2 respectively. Fish collagen matrix promoted NIH 3T3 and L6 cellular growth and proliferation. The study indicates that availability of pure fish collagen could replace bovine collagen in tissue engineering applications.
Estudo cinético da decomposi??o térmica do pentaeretritol-tetranitrado (PETN)
Silva, Gilson da;Nakamura, Nanci Miyeko;Iha, Koshun;
Química Nova , 2008, DOI: 10.1590/S0100-40422008000800028
Abstract: the pentaerythritol-tetranitrate (petn) is a nitroether used in explosives and propellant formulations. due to its suitable properties, petn is used in booster manufacture. knowing the thermal decomposition behavior of an energetic material is very important for storage and manipulation, and the purpose of this work is to study the kinetic parameters of the decomposition of petn, compare the results with literature data and to study the decomposition activation energy differences between two crystalline forms of petn (tetragonal and needle) by means of differential scanning calorimetry (dsc). fourier transform infrared spectroscopy (ft-ir) is used to study the two crystalline forms.
Nova Metodologia para Identifica??o de Componentes em Tintas Comerciais
Dutra, Rita C. L.;Takahashi, Marta F. K.;Diniz, Milton F.;
Polímeros , 2002, DOI: 10.1590/S0104-14282002000400010
Abstract: a new methodology was developed, including ftir techniques, for separation and characterization of the main ingredients of alkyd paints. this work shows the importance of coupled methods in the analysis of these materials. the method developed in our laboratories can be applied with some specific adaptations in the characterization of commercial paints of similar composition.
Determina??o quantitativa da concentra??o de silicone em antiespumantes por espectroscopia FT-IR / ATR e calibra??o multivariada
Garcia, Marcelo H. F.;Farias, Simone B.;Ferreira, Bianca G.;
Polímeros , 2004, DOI: 10.1590/S0104-14282004000500009
Abstract: this work presents an alternative method to determine the concentration of silicone (polydimethylsiloxane) in antifoaming products using fourier transformed infrared spectroscopy (ft-ir) with the attenuated total reflectance (atr) accessory. the spectra were recorded in the range from 2500 to 780 cm-1, with a resolution of 4 cm-1 and 128 scans. with calibration of a linear model using pls regression method applied to spectral data we were able to determine the silicone concentration in the samples. this method may be useful for antifoaming producers since the performance of such products generally is evaluated as a function of their viscosity. moreover, during manufacturing an incomplete homogenization of silicone in the solvent may occur, in which case the viscosity results are not representative of the samples. the determination of the silicone weight percentage is important to avoid losses in the production process and to help the statistical process control.
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