• The Journal of Advanced Prosthodontics
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• v.11 no.5
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• pp.253-261
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• 2019

PURPOSE. To evaluate the influence of cyclic loading on phase transformation of zirconia abutments and to compare the effectiveness of three different quantitative ageing assessment techniques. MATERIALS AND METHODS. Thirty two Y-TZP prostheses fabricated from two brands, InCoris ZI and Ceramill ZI, were cemented to titanium bases and equally divided into two subgroups (n=8): control group without any treatment and aged group with cyclic loading between 20 N and 98 N for 100,000 cycles at 4 Hz in distilled water at $37^{\circ}C$. The tetragonal-to-monoclinic phase transformation was assessed by (i) conventional x-ray diffraction (XRD), (ii) micro x-ray diffraction (${\mu}XRD$), and (iii) micro-Raman spectroscopy. The monoclinic-phase fractions (M%) were compared by two-way ANOVA. RESULTS. InCoris Zi presented significantly higher M% than Ceramill Zi in both control and aged groups (P<.001). Both materials exhibited significant phase transformation with monoclinicphase of 1 to 3% more in aged groups than controls for all three assessment techniques. The comparable M% was quantified by both ${\mu}XRD$ and XRD. The highest M% was assessed with micro-Raman. CONCLUSION. Cyclic loading produced significant phase transformation in tested Y-TZP prostheses. The micro-Raman spectroscopy could be used as an alternative to XRD and ${\mu}XRD$.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1171-1171
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• 2001

Quantitative analysis is an important requirement in exploration, mining and processing of minerals. There is an increasing need for the use of quantitative mineralogical data to assist with bore hole logging, deposit delineation, grade control, feed to processing plants and monitoring of solid process residues. Quantitative analysis using X-Ray Powder Diffraction (XRD) requires fine grinding and the addition of a reference material, or the application of Rietveld analysis to XRD patterns to provide accurate analysis of the suite of minerals present. Whilst accurate quantitative data can be obtained in this manner, the method is time consuming and limited to the laboratory. Mid infrared when combined with multivariant analysis has also been used for quantitative analysis. However, factors such as the absorption coefficients and refractive index of the minerals requires special sample preparation and dilution in a dispersive medium, such as KBr to minimize distortion of spectral features. In contrast, the lower intensity of the overtones and combinations of the fundamental vibrations in the near infrared allow direct measurement of virtually any solid without special sample preparation or dilution. Thus Near Infrared Spectroscopy (NIR) has found application for quantitative on-line/in line analysis and control in a range of processing applications which include, moisture control in clay and textile processing, fermentation processes, wheat analysis, gasoline analysis and chemicals and polymers. It is developing rapidly in the mineral exploration industry and has been underpinned by the development of portable NIR spectrometers and spectral libraries of a wide range of minerals. For example, iron ores have been identified and characterized in terms of the individual mineral components using field spectrometers. Data acquisition time of NIR field instruments is of the order of seconds and sample preparation is minimal. Consequently these types of spectrometers have great potential for in-line or on-line application in the minerals industry. To demonstrate the applicability of NIR field spectroscopy for quantitative analysis of minerals, a specific example on the quantification of lateritic bauxites will be presented. It has been shown that the application of Partial Least Squares regression analysis (PLS) to the NIR spectra can be used to quantify chemistry and mineralogy in a range of lateritic bauxites. Important, issues such as sampling, precision, repeatability, and replication which influence the results will be discussed.

• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.564-573
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• 2022

Calcium carbonate (CaCO₃) exhibits three polymorphs: calcite with arhombohedral, vaterite with a spherical, and aragonite with a needle-like structure. Qualitative and quantitative analyses of the morphology of CaCO₃ are very important to investigate the synthesis of single-crystal vaterite and aragonite. In this work, the polymorphs of calcium carbonate were quantitatively analyzed using XRD. Pure vaterite and pure aragonite were synthesized and the peak distribution of a single phase was analyzed. The vaterite fraction of a mixture of calcite and vaterite was calculated based on the intensity of a specific diffraction peak, and compared to the results based on the peak area. The mean value of f_sV (the correction factor for the peak area of vaterite) was 0.654. The phase analysis of calcite-aragonite mixtures was performed, and the mean value of f_sA (the correction factor for the peak area of aragonite) was obtained as 0.6713. Using these factors, Eq. (24)~Eq. (32) for the quantitative analysis based on the total peak area of XRD were derived to calculate the phase contents of ternary phase CaCO₃. And three-component XRD section was defined considering overlapping sections.

• Journal of the Mineralogical Society of Korea
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• v.5 no.1
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• pp.32-41
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• 1992

An XRD quantitative analytical method using calculated XRD patterns was discussed in this study, Deep-seabed sediments commonly contain smectite, illite, chlorite, and kaolinite, and XRD pattern of each clay mineral of appropriate chemical composition was simulated by using an XRD pattern calculation method. Theoretical peak intensities of specific reflections of four clay minerals (the 001 reflections of smectite and illite, the 004 reflection of chlorite, and the 002 reflection of kaolinite) were measured from calculated patterns, and MIF(mineral intensity factor)value of each phase was determined from the intensities of calculated patterns. The peak intensities obtaine from experimental XRD patterns of sediments were corrected using the MIF values so that the calibrated intensity values for the specimens are linearly proportional to the weight fraction of each phase, which is normalized to 100 wt%. The MIF method can provide accurate quantitaive results without the necessity of correcting the factors by the mass absorption coefficient of each phase. This method excludes the necessity of standard specimens having compositions that are similar to those of clay minerals in the sediment samples. Therefore, quantitaive analysis using XRD calculation method can be utilized for the specimens, for which the standard specimens are very difficult or impossible to obtain. this quantitative method can provide rapid, routine analysis results for a large number of samples which occur in similar geological environments.

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.995-998
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• 2003

This paper reports the correlation between dielectric constant and degree of amorphism of the hybrid type Si-O-C thin films. Si-O-C thin films were deposited by high density plasma chemical vapor deposition using bistrimethyl- silylmethane(BTMSM, $H_{9}$C$_3$-Si-C $H_2$-Si-C$_3$ $H_{9}$) and oxygen precursors with various flow rate ratio. As-deposited film and annealed films at 40$0^{\circ}C$ were analyzed by XRD. The Si-O-C thin films were amorphous from XRD patterns. For quantitative analysis, the diffraction pattern of the samples was transformed to radial distribution function by Fourier analysis, and then compared with each other. The degree of amorphism of annealed films was higher than that of as-deposited ones. The dielectric constant varied in accordance with flow rate ratio of precursors. The lowest dielectric constant was obtained from the as-deposited film which has the highest degree of amorphism after annealing.

• Journal of the Korean Ceramic Society
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• v.40 no.5
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• pp.481-487
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• 2003

A technique for determination of proportions of char, coal ana coke is needed in order to monitor pulverized coal injection performance in operating blast furnace. Quantitative X-ray powder diffraction analysis can be applied to the problem providing that structural information on carbonaceous materials, coal, char, coke and their mixture are known. Chars were prepared from a coal at different temperatures (1000∼1400$^{\circ}C$) and were characterised by X-Ray powder Diffraction (XRD). The XRD result gave crystallite size (height Lc and diameter, La), aromaticity, number of (002) plane in carbon, and d-spacing. As a result, with increasing heat treat temperature of char, Lc$_{(002)}$, La$_{(10)}$ and number of (002) plane in carbon were increased, and d-spacing and FWHM(Full With Half Maximum) were decreased. Result of prediction of amount of char from the mixtures (char, coke and ore) based on the Lc$_{(002)}$ information of two mixtures (coke and char) showed very close values expected.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.770-772
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• 2010

기존의 연구는 열화에 의한 물리적 평가 및 열화에 영향을 미치는 수화생성물의 존재여부에 대한 연구는 활발하게 이루어지고 있으나, 그에 따른 수화생성물의 정량화에 대한 연구는 미흡한 실정이다. 본 논문은 XRD 분석 기법을 이용하여 원전 콘크리트 구조물에 대해 열화요인 중 탄산화와 황산염에 대한 상대적 정량화에 대한 연구를 실시하였다. 두 열화인자는 콘크리트 내의 수산화칼슘과 반응하여 에트린가이트와 탄산칼슘을 생성하게 되는데, 본 연구에서 열화인자에 대한 노출기간이 증가할수록 열화에 영향을 미치는 수화 생성물이 증가하는 것을 확인 할 수 있었다. 그에 따른 수산화칼슘의 양이 감소하는 것도 확인 할 수 있었다.

• Journal of the Korea Institute of Building Construction
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• v.20 no.1
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• pp.11-18
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• 2020

Carbon nanotubes are used in various industries with their excellent mechanical properties and electrical conductivity. In the construction industry, research is being conducted to give self-sensing capabilities to structures, but the results of experiments vary among researchers, and the analysis is insufficient. Therefore, in this study, the hydration and electrical properties of MWCNT-added cement pastes were measured. The electrical resistance values of hydration heat, porosity, Rietveld quantitative analysis, compressive strength, and distance were measured.. The heat resistance, porosity, Rietvelt quantitative analysis, compressive strength and distance were measured according to electrical resistance. Experimental results showed that the heat of hydration decreased with increasing MWCNT. XRD Rietveld quantitative analysis showed that there was no significant difference in the amount of hydration products with increasing addition rate of MWCNT. As a result of SEM analysis, the MWCNT is agglomerated by van der Waals forces, and this area is considered to be caused by voids and weak areas. The electrical resistance value decreases as the addition rate is increased, and thus may play a role for magnetic sensing in the future.

• Journal of Environmental Health Sciences
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• v.35 no.2
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• pp.130-142
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• 2009

This study compared FTIR with XRD method for the analysis of quartz by % recovery, coefficient of variation (CV) and influence of the interference. the results were as the following. 1. In FTIR method, the coefficient of determination ($r^2$) was 0.9998 in a calibration curve of $695\;cm^{-1}$, and the limit of detection was $4.9{\mu}g/sample$. 2. The highest recovery was $799\;cm^{-1}$ (98.2%). 3. The CVpooled of the FTIR method was approximately 10% in three wave numbers. 4. The analysis of qualitative and quantitative for quartz is difficult with mixed cristobalite and iron oxide. 5. In XRD method with rotating sample holder and LynxEye detector, the coefficient of determination was 0.9996 in a calibration curve, and the limit of detection was $5.9{\mu}g/sample$. 6. The recovery and CV pooled were 104.3%, and 11 %, respectively. 7. In muffle furnace ashing, the quartz weight decreased to 34% when the maximum weight of the iron oxide was more than eight times. In conclusion, the accuracy (% recovery) and precision (CV) of FTIR and XRD method for analyzing $\alpha$-quartz were similar. FTIR method was a disadvantage for sample matrix because it indicates possibility of interference. However, XRD method distinguished specific crystalline forms of silica, and the majority of silicate minerals. In addition, XRD method recommend filter dissolution to pretreatment method.

• The Korea Journal of Herbology
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• v.33 no.6
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• pp.87-92
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• 2018

Objectives: The aim of the study was to analyze the constituents of Pyrolusitum, which was used to eliminate static blood and inflammation, to establish the basis of clinical application. Methods: Qualitative analysis was performed by X-Ray Diffraction (XRD) using the sample as a powder, and the elemental content of granular sample was measured by X-Ray Fluorescence (XRF). 1 M hydrochloric acid and 5% sodium hydroxide aqueous solution were added to observe the changing shape, respectively. Results: Qualitative analysis by XRD revealed that the Pyrolusitum samples used in the study contained quarts and kaolinite. Quantitative analysis by XRF revealed that the manganese content in the samples used in the study was 6.16% on average, while iron was contained the highest amount of 22.99%. The minor constituents include 1.08% of titanium, 0.30% of barium, 0.18% of lead, 0.06% of zirconium, 0.05% of chromium, 0.04% of zinc, 0.03% of cadnium, 0.02% of nickel, 0.01% of arsenic, 0.01% of copper, 0.01% of rubidium, 0.01% of strontium, 0.00% of molybdenum, respectively. And cobalt, which is reported to be a constituent of Pyrolusitum, was not detected at all in the samples of the study. Pyrolusitum was dissolved in dark brown when it was put into 1 M hydrochlorid acid, and there was brown precipitate when sodium hydroxide solution was added to Pyrolusitum and stirred. Conclusions: It was found that manganese and iron were the major constituents of Pyrolusitum, and it could be identified by using concentrated hydrochloric acid and sodium hydroxide solution.