Papers by Keyword: ATR

Abstract: In this paper, the relative change rates of content of conjugated fatty acid glycerides, content of tans-fatty acid glycerides, unsaturation and linear long-chain fatty acid glycerides were explored after being at high temperature for several hours by using FTIR-ATR. The results hints:1.Starting from 160°C, the contents of conjugated fatty acids glycerides and trans-fatty acid glycerids in the vegetable oils increase but unsaturation and content of linear long-chain fatty acid glycerides decreases with heating temperature and heating time increasing; 2. When heating temperature reaches 200°C or more, the heating time up to four hours or longer, the four indicators (conjugated fatty glycerids, trans-fatty acid glycerids, unsaturation and linear long-chain fatty acid glycerides) of five kinds of vegetable oils have substantial changes; 3. The content of linoleic acid in the vegetable oil has some contributions to the change amplitude of contents of conjugated fatty acid glycerides, and the content of oleic acid in the vegetable oil has some contributions to the change amplitude of content of trans-fatty acid glycerides. Because refined “waste oil” experiences a longer history at temperature higher than 200 °C compared to the vegetable oil, four index value and its variation can be used as specific indicators for it.

Abstract: Using Fourier transform infrared spectroscopy (FTIR), attenuated total reflection (ATR) technology and partial least square (PLS) method, the rapid quantification method of hemoglobin (HGB) in human soluble blood samples was established. Based on the distribution of samples’ HGB chemical value and absorbance on 1543 cm^-1 which had the highest signal to noise ratio for HGB, all samples were divided into calibration set and prediction set for 50 times. PLS models were established for all divisions, based on the average data RMSEP_Ave, the stable optimal model was selected, the corresponding PLS factor, RMSEP_Ave and R_P,Ave were 2, 6.81 g/L and 0.943 respectively.

Abstract: A directly rapid quantitative analysis method for chemical oxygen demand (COD) of wastewater was established by Fourier transform infrared (FTIR) spectroscopy and attenuated total reflection (ATR) technology. The combination selection of Savitzky-Golay (SG) smoothing modes combined with partial least squares (PLS) factor was applied to the model optimization here. The optimal smoothing parameters were 2^nd order derivative smoothing, 6^th degree polynomial and 51 smoothing points. The corresponding optimal PLS factor, root mean squared error of predication (RMSEP) and correlation coefficient of predication (R_P) were 11, 24.4 (mg/L) and 0.968 respectively, which was obviously superior to the direct PLS model without SG smoothing. This demonstrated that the combination selection of SG smoothing parameters and PLS factor can be effectively applied to the model optimization for FTIR/ATR analysis of COD in wastewater.

Abstract: The study aimed the evaluation of the effect of osseous repair in the synthetic hydroxyapatite cylinder (HA) implanted in rabbit’s tibia. Fifteen adult animals, weighing around 2.5 and 3.0 Kg, sourced by the Fluminense Federal University Animal Lab were anesthetized with spinal anesthesia, and two perforations were created in right tibia and filled with cylinders (2 x 6 mm) of HA. The animals were killed after 28 days for evaluating the HA cylinder through attenuated total reflection infrared microscopy (ATR-FTIR). The two fragments of tibia with the cylinder were collected and fixed in alcohol 70° prior to dehydration in successive alcohol solutions and then impregnated and embedded in methyl-methacrylate. Not stained neither pasted to lamina, sections of 200 µm thickness were analyzed in a Shimadzu IRPrestige-21 Automatic Infrared Microscope (AIM-8800) with ATR Objective Mirror (ATR-8800M). Prior to implantation, HA cylinder was characterized by X-Ray diffraction (XRD), Attenuated Total Reflection- Infra Red microscopy (ATR-FTIR) and X-Ray Fluorescence (XRF). After the implantation, the spectrum of the ATR-FTIR at the interface to neoformed bone was acquired. The hydroxyapatite synthesized was crystalline and stoichiometric with Ca/P ratio of 1.66, becoming carbonated after 28 days of implantation. We conclude that attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) is a useful tool for biomaterial evaluation and able to detect the modification of the chemical HA cylinder pattern occurred probably by ions migration in the biological environment.

Abstract: Adhesion, or the binding of different materials at an interface, is of general interest to many branches of technology, e.g., micro-electronics, tribology, manufacturing, construction, etc. In addition, varieties of plasma treatments for the adhesion control of polymers are still extensively studied by a lot of researchers. However, there is a lack of research that decreases the adhesion force by using plasma treatment devices. Thus, this paper study to decrease the adhesion force between a medical rubber, chloride-isobutene-isoprene rubber (CIIR), and stainless-steel SUS440C by using oxygen plasma treatment. The different adhesion forces were measure after plasma treatment with various methods. The elastic modulus was increased by oxygen plasma treated to the CIIR specimen. The results show that the elastic modulus was increased 15% to 28% as the plasma treated to the CIIR specimen. Experiment results showed that the adhesion force decreased by about 95-99.8% by using oxygen plasma treatments between CIIR and SUS440C. The different adhesion forces were explained based on the morphology and Attenuated Total Reflectance (ATR) FTIR.

Abstract: The effect of the temperature at which the carbon source is introduced in the reactor on the early stages of the carbonization process is analyzed here. Three samples heated up to 1150°C with propane introduction temperatures (Tintro) of 725, 1030 and 1100°C are analyzed by transmission electron microscopy and attenuated total reflectance. The size of the SiC nuclei increases with Tintro. There is also an effect on the strain of the resulting carbonization layer. The electron diffraction pattern of the sample with the highest Tintro shows a fully relaxed 3C-SiC layer, while no evidence of SiC relaxation is present in low Tintro samples where the SiC islands seems to be pseudomorphic.