scholarly journals Automated Distinction between Cement Paste and Aggregates of Concrete Using Laser-Induced Breakdown Spectroscopy

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4624
Author(s):  
Pakdad Pourbozorgi Langroudi ◽  
Gesa Kapteina ◽  
Marcus Illguth
Keyword(s):  
Cement Paste ◽  
Heterogeneous Materials ◽  
Transport Processes ◽  
Laser Induced Breakdown Spectroscopy ◽  
Hardened Cement ◽  
Limit Values ◽  
Breakdown Spectroscopy ◽  
Distribution Of Elements ◽  
Laser Induced Breakdown ◽  
To Receive

Laser-induced breakdown spectroscopy (LIBS) is a technique which enables the analysis of material components with precision and spatial resolution. Furthermore, the investigation method is comparatively fast which enables illustrating the distribution of elements within the examined material. This opens new possibilities for the investigation of very heterogeneous materials, such as concrete. Concrete consists of cement, water, and aggregates. As most of the transport processes take place exclusively in the hardened cement paste, relevant limit values linked to harmful element contents are specified in relation to the cement mass. When a concrete sample from an existing structure is examined, information on the concrete composition is usually not available. Therefore, assumptions have to be made to convert the element content analyzed in the sample based on the cement content in the sample. This inevitably leads to inaccuracies. Therefore, a method for distinction between cement paste and aggregates is required. Cement and aggregate components are chemically very close to each other and therefore, complex for classification. This is why the consideration of a single distinguishing feature is not sufficient. In this paper, a machine learning method is described and has been used to automate the distinction of the cement paste and aggregates of the LIBS data to receive reliable information of this technique. The presented approach could potentially be employed for many heterogeneous materials with the same complexity to quantify the arbitrary substances.

Development and Commercial Evaluation of Laser-Induced Breakdown Spectroscopy Chemical Analysis Technology in the Coal Power Generation Industry

2002 ◽  
Vol 56 (1) ◽  
pp. 70-74 ◽  
Author(s):  
Bruce L. Chadwick ◽  
Doug Body
Keyword(s):  
Heterogeneous Materials ◽  
Laser Induced Breakdown Spectroscopy ◽  
Acid Extraction ◽  
Charge Coupled Device ◽  
Breakdown Spectroscopy ◽  
Power Stations ◽  
Laser Induced Breakdown ◽  
Fuel Source ◽  
Multiple Charge

An instrumentation variation on laser-induced breakdown spectroscopy (LIBS) has been developed and applied in the operations of power generating companies utilizing low-ash lignite as the fuel source. The instrument design allows simultaneous determination of all detectable elements using a multiple spectrograph and a synchronized, multiple charge-coupled device (CCD) spectral acquisition system. The application of internal ratio analysis has enabled the development of a stable system that can be operated routinely for over a month without recalibration. Detection limits vary depending on the element but are typically on the order of 0.01% by weight for heterogeneous materials such as the moist lignite used in these power stations. Independent testing of the instrument has shown good correlation between the routine LIBS analysis and the analysis of the coal via acid extraction techniques for key ash-forming elements. Testing over a one month period shows excellent correlation between the two methods for elements such as Al ( R = 0.96) and Na ( R = 0.92). The principle limitation is not the accuracy of the LIBS method but rather the inherent errors in sampling heterogeneous materials such as lignite. Because the LIBS analysis takes less than 30 seconds it has clear advantages over traditional methods used in elemental analysis for these materials.

Nanosecond laser-induced breakdown assisted by femtosecond laser pre-ionization in air: the effect on spatial resolution and continuous radiation

2020 ◽  
Vol 92 (2) ◽  
pp. 20701
Author(s):  
Bo Li ◽  
Xiaofeng Li ◽  
Zhifeng Zhu ◽  
Qiang Gao
Keyword(s):  
Femtosecond Laser ◽  
Spatial Resolution ◽  
Laser Induced Breakdown Spectroscopy ◽  
Nanosecond Laser ◽  
Breakdown Threshold ◽  
Powerful Technique ◽  
Breakdown Spectroscopy ◽  
Continuous Radiation ◽  
Laser Induced Breakdown

Laser-induced breakdown spectroscopy (LIBS) is a powerful technique for quantitative diagnostics of gases. The spatial resolution of LIBS, however, is limited by the volume of plasma. Here femtosecond-nanosecond dual-pulsed LIBS was demonstrated. Using this method, the breakdown threshold was reduced by 80%, and decay of continuous radiation was shortened. In addition, the volume of the plasma was shrunk by 85% and hence, the spatial resolution of LIBS was significantly improved.

Characterization of Amethysts from Sukamara, Central Kalimantan, Using Laser-Induced Breakdown Spectroscopy (LIBS)

2020 ◽  
Vol 1 (2) ◽  
pp. 5-8
Author(s):  
Komang Gde Suastika, Heri Suyanto, Gunarjo, Sadiana, Darmaji
Keyword(s):  
Emission Intensity ◽  
Laser Energy ◽  
Emission Spectra ◽  
Atomic Emission ◽  
Laser Induced Breakdown Spectroscopy ◽  
Chemical Formula ◽  
Central Kalimantan ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown

Abstract - Laser-Induced Breakdown Spectroscopy (LIBS) is one method of atomic emission spectroscopy using laser ablation as an energy source. This method is used to characterize the type of amethysts that originally come from Sukamara, Central Kalimantan. The result of amethyst characterization can be used as a reference for claiming the natural wealth of the amethyst. The amethyst samples are directly taken from the amethyst mining field in the District Gem Amethyst and consist of four color variations: white, black, yellow, and purple. These samples were analyzed by LIBS, using laser energy of 120 mJ, delay time detection of 2 μs and accumulation of 3, with and without cleaning. The purpose of this study is to determine emission spectra characteristics, contained elements, and physical characteristics of each amethyst sample. The spectra show that the amethyst samples contain some elements such as Al, Ca, K, Fe, Gd, Ba, Si, Be, H, O, N, Cl and Pu with various emission intensities. The value of emission intensity corresponds to concentration of element in the sample. Hence, the characteristics of the amethysts are based on their concentration value. The element with the highest concentration in all samples is Si, which is related to the chemical formula of SiO2. The element with the lowest concentration in all samples is Ca that is found in black and yellow amethysts. The emission intensity of Fe element can distinguish between white, purple, and yellow amethyst. If Fe emission intensity is very low, it indicates yellow sample. Thus, we may conclude that LIBS is a method that can be used to characterize the amethyst samples.Key words: amethyst, impurity, laser-induced, breakdown spectroscopy, characteristic, gemstones

Research progress on portable laser-induced breakdown spectroscopy

2020 ◽  
Vol 13 (6) ◽  
pp. 1-18
Author(s):  
ZENG Qing-dong ◽  
◽  
YUAN Meng-tian ◽  
ZHU Zhi-heng ◽  
CHEN Guang-hui ◽  
...  
Keyword(s):  
Research Progress ◽  
Laser Induced Breakdown Spectroscopy ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown
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