scholarly journals Quantitative evaluation of cement paste carbonation using Raman spectroscopy

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Tangwei Mi ◽  
Yongqiang Li ◽  
Wei Liu ◽  
Weiwen Li ◽  
Wujian Long ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Cement Paste ◽  
Underlying Mechanism ◽  
Reinforced Concrete Structures ◽  
Carbonation Depth ◽  
Peak Intensity ◽  
Standard Specimens ◽  
Quantification Analysis ◽  
Raman Peak Intensity ◽  
Good Agreement

AbstractCarbonation induced corrosion is one of the major durability issues for reinforced concrete structures. To address this issue, it is essential to understand the underlying mechanism of carbonation by detecting the ingress of the CO2 and carbonation depth quantitatively. This paper demonstrates the potential of Raman spectroscopy, as a powerful technique, to implement quantification analysis of cement paste carbonation. In present work, the correlation between the content of the CO32− and the Raman peak intensity was initially established by using several standard specimens premixed with certain amount of CO32−. The established correlation was then used to investigate the carbonation of the cement paste in a CO2 diffusion scenario, and the results show a good agreement with that obtained by thermogravimetry measurements. Therefore, the feasibility of the Raman spectroscopy to quantify the carbonation degree of the cement paste can be demonstrated.

scholarly journals Analysis of Sildenafil in Liquor and Health Wine Using Surface Enhanced Raman Spectroscopy

2019 ◽  
Vol 20 (11) ◽  
pp. 2722
Author(s):  
Shupei Xiao ◽  
Yong He
Keyword(s):  
Raman Spectroscopy ◽  
Surface Enhanced Raman Spectroscopy ◽  
Raman Peak ◽  
Peak Intensity ◽  
Raman Enhancement ◽  
Relative Standard ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Alcoholic Drinks ◽  
Raman Peak Intensity

The illegal adulteration of sildenafil in herbal food supplements and alcoholic drinks immensely threatens human health due to its harmful side-effects. Therefore, it is important to accurately detect and identify the presence of sildenafil in alcoholic drinks. In this study, Opto Trace Raman 202 (OTR 202) was used as surface enhanced Raman spectroscopy (SERS) active colloids to detect sildenafil. The results demonstrated that the Raman enhancement factor (EF) of OTR 202 colloids reached 1.84 × 107 and the limits of detection (LODs) of sildenafil in health wine and liquor were found to be as low as 0.1 mg/L. Moreover, the SERS peaks of 645, 814, 1235, 1401, 1530 and 1584 cm−1 could be qualitatively determined as sildenafil characteristic peaks and the relationship between Raman peak intensity and sildenafil concentration in health wine and liquor were different. There was a good linear correlation between Raman peak intensity, and sildenafil concentration in health wine ranged 0.1–1 mg/L (0.9687< R2 < 0.9891) and 1–10 mg/L (0.9701 < R2 < 0.9840), and in liquor ranged 0.1–1 mg/L (0.9662 < R2 < 0.9944) and 1–20 mg/L (0.9625 < R2 < 0.9922). The relative standard deviations (RSD) were less than 5.90% (sildenafil in health wine) and 9.16% (sildenafil in liquor). The recovery ranged 88.92–104.42% (sildenafil in health wine) and 90.09–104.55% (sildenafil in liquor). In general, the sildenafil in health wine and liquor could be rapidly and quantitatively determined using SERS technique, which offered a simple and accurate alternative for the determination of sildenafil in alcoholic drinks.

scholarly journals FABRICATION AND PROPERTIES OF Co DOPED Bi0.5K0.5TiO3 – BiFeO3 SOLID SOLUTION

2018 ◽  
Vol 56 (1A) ◽  
pp. 197
Author(s):  
Nguyen Hoang Tuan
Keyword(s):  
Solid Solution ◽  
Raman Spectroscopy ◽  
Magnetic Properties ◽  
Crystal Structures ◽  
Solid Solutions ◽  
Sol Gel ◽  
Structure And Properties ◽  
Antiferromagnetic Ordering ◽  
Co Doped ◽  
Good Agreement

In this study, we present some results on the structure and properties of the solid solution of Bi0.5K0.5TiO3– BiFeCoO3 (BKT – BFCO) by Sol-gel method. Crystal structures of BKT – BFCO solid solutions were studies by XRD and Raman spectroscopy. The results were in good agreement with the previous reports of Bi0.5K0.5TiO3– BiFeO3 (BKT – BFO) and Bi0.5K0.5TiO3 – BiCoO3 (BKT – BCO) solid solutions. The magnetic properties were investigated via unsaturated M-H loop, which showed the competition of paramagnetic and antiferromagnetic ordering in BKT – BFCO. However, differing from the BKT – BFO and BKT – BCO solid solutions, the unclear values of saturated magnetism in BKT – BFCO raised the unexplained question, which needed further studies.

Liquid Core Optical Fibers in Raman Spectroscopy

1981 ◽  
Vol 35 (4) ◽  
pp. 439-442 ◽  
Author(s):  
Howard B. Ross ◽  
William M. McClain
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Optical Fibers ◽  
Liquid Core ◽  
Geometrical Optics ◽  
Laser Spectrometer ◽  
Trans Stilbene ◽  
Scan Speed ◽  
Good Agreement

Raman spectra of samples contained in hollow quartz fibers are compared quantitatively to conventional Raman spectra using identical laser, spectrometer, detector, and scan speed. We find the fiber signal to be enhanced by a factor of 250/m of fiber, in good agreement with calculations based on geometrical optics. A fiber spectrum of 2 mol% trans-stilbene in benzene is good enough to allow essentially perfect solvent subtraction.

Use of Raman spectroscopy to characterize the effect of nanomagnetite as an addition to Portland cement paste on mitigating internal sulfate attack

2020 ◽  
Vol 262 ◽  
pp. 120803
Author(s):  
Tassiane A. Oliveira ◽  
Igor M. Pinkoski ◽  
Mariana O.G.P. Bragança ◽  
André Assmann ◽  
Isabela C. Oliveira ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Portland Cement ◽  
Cement Paste ◽  
Sulfate Attack ◽  
Portland Cement Paste ◽  
Internal Sulfate Attack

Study on Seismic Behavior of Vertical Connection in Prefabricated Reinforced Concrete Structures

2011 ◽  
Vol 250-253 ◽  
pp. 1385-1394
Author(s):  
Guo Hua Song ◽  
Dong Wei Wang ◽  
Bing Kang Liu
Keyword(s):  
Reinforced Concrete ◽  
Seismic Behavior ◽  
Concrete Structures ◽  
Shear Resistance ◽  
Repeated Loading ◽  
Reinforced Concrete Structures ◽  
Test Results ◽  
Dowel Action ◽  
Cycle Loading ◽  
Good Agreement

The paper attempts to research the seismic behavior and mechanical mechanisms under repeated low-cycle loading of vertical connections in prefabricated reinforced concrete structures. Eighteen specimens were designed and tested, the test process and the mechanical mechanisms are studied, the seismic behavior of connections is analyzed, and the shear resistance formulas are proposed. The theoretical values based on proposed formulas are good agreement with test results. Under repeated loading, the shear resistance decreases, the connection ductility increases with connecting bar, but decreases with connection width. However, all the connections fail crisply with poor ductility. At sudden-cracking, the shear resistance increases with connecting bar, but changes nonlinearly with connection width. The resistance is composed of attributions of mechanism of diagonal-compressive column (MDCC) and mechanism of compressive friction action (MCFA). After sudden-cracking, the shear resistance is provided by weakened MDCC and dowel action of connecting bars (DACB). It increases with connecting bar and connection width.

Experimental Study on Strength of Rock Masses with Transfixion Joint under Uniaxial Compression

2013 ◽  
Vol 353-356 ◽  
pp. 856-859
Author(s):  
Lei Wang ◽  
Shi Chen Li ◽  
Jian Xin Han ◽  
Zhong Yi Zeng
Keyword(s):  
Uniaxial Compression ◽  
Testing Machine ◽  
Jointed Rock ◽  
Servo Control ◽  
Peak Strength ◽  
Rock Masses ◽  
Peak Intensity ◽  
Standard Specimens ◽  
Joint Inclination ◽  
The Relationship

The relationship between the peak strength of rock masses and joint inclination angle is closely, to study its relationship, experiment on pre-existing persistent jointed rock cylindrical standard specimens was made under uniaxial compression by high stiffness servo control testing machine, experiment found that: the residual peak intensity and peak strength are increased with the decrease of jointed and nonlinear. Analysis on the peak intensity changing with the fissure inclination using Kulun strength theory, theory analysis conclusion is consistent with the experiment, prove the conclusions of experiments and theoretical analysis all can reflect the law of rock masses with transfixion joint failure strength well.

Structural and Ferromagnetic Properties of Ho-Doped BiFeO3 Films

2017 ◽  
Vol 727 ◽  
pp. 996-1000 ◽  
Author(s):  
Ning An ◽  
Hai Tao Zhang ◽  
Cheng Zhi Liu ◽  
Cun Bo Fan ◽  
Xue Dong ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Raman Spectroscopy ◽  
Room Temperature ◽  
Oxygen Vacancies ◽  
Sol Gel ◽  
Wave Number ◽  
Ferromagnetic Property ◽  
Peak Intensity ◽  
Structure Morphology ◽  
Xrd Patterns

In order to improve the structural and ferromagnetic property of BiFeO3, the effects of Ho3+ doping is systematically investigated. Pure BiFeO3 and Ho-doped BiFeO3 thin films are fabricated by sol-gel method, and the phase structure, morphology, crystalline structure, ferromagnetic are characterized by XRD, SEM, Raman spectra and VSM, respectively. The XRD patterns of the samples indicate that all the compounds crystallize in rhombohedral distorted perovskite structure with space group R3c and the Ho substitution can suppress the intrinsic formation of the miscellaneous phase. The SEM proves that along with the increasing of Ho concentration, the surface roughness of BiFeO3 is decreased due to the reduction of defects in the preparation. From the Raman spectroscopy, it is found that the peak intensity of 8 modes in Bi1-xHoxFeO3 are increased and the modes shift to higher wave number. Besides, the VSM results show that the ferromagnetic of the samples is enhanced with increasing of Ho concentration. When x=0.1, Ms is improved to be 4.8emu/g. The results can prove that the Ho3+ doping can reduce the volatilization of Bi3+, decrease the concentration of oxygen vacancies and improve the room-temperature ferromagnetic of BiFeO3.

A New Technique for the Elimination of Fluorescence Interference in Raman Spectroscopy

1986 ◽  
Vol 40 (5) ◽  
pp. 583-587 ◽  
Author(s):  
Frank V. Bright ◽  
Gary M. Hieftje
Keyword(s):  
Raman Spectroscopy ◽  
Rhodamine 6G ◽  
Microwave Spectrum ◽  
New Instrument ◽  
Ion Laser ◽  
A New Technique ◽  
Relative Errors ◽  
Argon Ion ◽  
Raman Scatter ◽  
Good Agreement

A new instrument for Raman spectroscopy has been constructed with the use of a cw or mode-locked argon-ion laser as the excitation source and a microwave spectrum analyzer for discrimination between fluorescence and Raman scatter. To demonstrate the new instrument's capability, the weak Raman scatter of water was resolved from the intense fluorescence from rhodamine 6G. Theoretically predicted relative errors in the new procedure are calculated and experimental results are shown to be in good agreement with theory.

Prediction of the Carbonation Depth of Concrete with a Mortar Finish

2008 ◽  
Vol 385-387 ◽  
pp. 633-636 ◽  
Author(s):  
Han Seung Lee ◽  
Xiao Yong Wang
Keyword(s):  
Portland Cement ◽  
Numerical Procedure ◽  
Pozzolanic Reaction ◽  
Surface Coatings ◽  
Reinforced Concrete Structures ◽  
Hydration Products ◽  
Application Time ◽  
Carbonation Depth ◽  
Hydration Model ◽  
Corrosion Of Steel

It is well known that carbonation will result corrosion of steel reinforcement in reinforced concrete structures. To reduce the rate of carbonation, the surface coatings, such as mortar finish, has been used widely to concrete. This paper presents a numerical procedure about carbonation of the coating-concrete system. This numerical procedure starts with a multi-component hydration model. By hydration model which considers both and Portland cement and pozzolanic reaction, the amount of hydration products which are susceptible to carbonate as well as porosity is obtained as function of age. Furthermore, the diffusivity of CO2 is determined and carbonation depth of concrete is predicted. Parameter studies are performed to show the influence of composition and application time of mortar finish on carbonation depth of substrate concrete.

Monitoring of Chemical Speciation of DEA – CO2 – Water System by Raman Spectroscopy

2015 ◽  
Vol 1113 ◽  
pp. 358-363 ◽  
Author(s):  
Muhammad Zubair Shahid ◽  
Humbul Suleman ◽  
Adulhalim Shah Maulud ◽  
Mohammad Azmi Bustam Khalil ◽  
Zakaria Man
Keyword(s):  
Raman Spectroscopy ◽  
Water System ◽  
Chemical Species ◽  
Principal Component Regression ◽  
Principal Component ◽  
Carbon Dioxide Separation ◽  
Key Factor ◽  
Kinetics Of ◽  
Respective Characteristic ◽  
Good Agreement

Carbon dioxide separation has gained immense importance since its detrimental effects towards our environment has been realized. Commercially, CO2has been captured by absorption in alkanolamines such as diethanolamine (DEA), since many years. The thermodynamics and kinetics of the process is a key factor towards its efficiency and significantly depends on its qualitative and quantitative speciation. In this work, the analysis of speciation for CO2loaded aqueous DEA has been performed by Raman spectroscopy. Experimentally determined CO2loading data and modified Kent Eisenberg equation was used to quantify the chemical species present. The speciation results were fitted with the respective characteristic Raman peaks of (CO3-, HCO3-, DEACOO-, DEA, DEA+, CO2) by Principal Component Regression (PCR). The fitted results showed good agreement with thermodynamically predicted chemical species.

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