Accurate Quantitative Analysis Research Articles

A LIBS spectrum baseline correction method based on the non-parametric prior penalized least squares algorithm.

Laser-induced breakdown spectroscopy (LIBS) has become a popular element analysis technique because of its real-time multi-element detection and non-damage advantages. However, due to factors such as laser-substance interaction and the experimental environment, the measured LIBS spectrum signal contains a continuous background, severely influencing spectrum analysis. In this paper, we propose a LIBS spectrum baseline correction method based on the non-parametric prior penalized least squares (NPPPLS) algorithm. Compared with the traditional Penalized Least Squares (PLS) method, improvements have been made in two aspects. On the one hand, a new weight method with faster convergence is proposed. On the other hand, we combine the Adam algorithm and introduce the RMSE of the baseline correction result at the previous time to constrain the update of the balance parameter, which enables the balance parameter to be adjusted adaptively and no parameter prior is required. The simulation results show that the proposed NPPPLS algorithm can achieve excellent correction results, even with no parametric priors. In addition, the performance of the NPPPLS algorithm is not affected by the initial value of the balance parameter, and the stability and robustness are significantly improved. Finally, we conducted baseline correction of the experimental LIBS spectrum and performed univariate and multivariate analyses. The results show that the quantitative analysis accuracy is improved after baseline correction, and the correlation coefficient R2 of different elements obtained by the extreme learning machine method of multivariate analysis can reach 0.99, demonstrating a better quantitative analysis result. The simulation and experimental results verify the excellent performance of the proposed NPPPLS algorithm, which can be effectively used to improve the accuracy of quantitative analysis. In addition, this method is also expected to be used for baseline correction of the Raman spectrum, near-infrared spectrum and so on.

Application of S-transform-based nonlinear processing for accurate LIBS quantitative analysis of iron ore slurry.

Real-time Fe content monitoring in iron ore slurry is crucial for evaluating concentrate quality and enhancing mineral processing efficiency. Laser-induced breakdown spectroscopy (LIBS) is a promising technique for the online monitoring of elemental content at industrial sites. However, LIBS measurements are hampered by the matrix effect and the self-absorption effect, limiting the precision of linear analytical processes. To overcome this, we propose to introduce a nonlinear processing unit based on the S-transform to incorporate nonlinearity into the data analysis process. This approach integrates a feature selection unit based on the spectral distance variable selection method (SDVS), a nonlinear processing unit based on the S-transform (ST), and a partial least squares regression model (PLS). To demonstrate the improvement in accuracy achieved through nonlinear processing, a comparative analysis involving five models, Raw-PLS, SDVS-PLS, ST-PLS, SDVS-ANN, and SDVS-ST-PLS, is conducted. The results reveal a significant improvement in the performance of the SDVS-ST-PLS model, effectively facilitating the successful application of the LIBSlurry analyzer to the mineral flotation process.

Effects of Different Oxygen Levels and Time Points on Mitochondrial Respiratory Functional Analysis of Placental Tissue

The placenta plays an important role in fetal growth and development. The Oxygraph-2k mitochondrial function respirometer provides an accurate and realistic quantitative analysis of mitochondrial respiratory function and the energy metabolism of organisms. However, this machine is used less frequently in placental tissues, which consume do not consume as much oxygen as the heart, brain, or skeletal muscle tissues, therefore, it is crucial to develop a standard respiratory measurement protocol for placental tissues. For this, we tested varying oxygen concentrations (150–160 (ambient air), 200, 250, and 300 μM) and time tissue remains viable in respiratory medium (1.5~3, 3~4.5, 4.5~6, and 6~7.5 hour) to determine the optimal experimental conditions. As a result, we found no significant changes in mitochondrial respiratory capacity at different oxygen levels, whilst there was a decrease in mitochondrial respiratory capacity more than 3 hour after delivery.

Mass filtering combined with photochemical derivatization enables high throughput mass spectrometric analysis of unsaturated phosphatidylcholine isomers.

Phosphatidylcholines (PCs) are closely related to coronary heart disease, such as myocardial infarction. The analysis of the deep structure of PCs is of great significance for exploring the effects of exercise rehabilitation and lipid metabolism. Here, we present a mass filtering combined with photochemical derivatization method for rapid screening and accurate identification of the CC position and sn-location isomer of PCs. This method is simple to execute and easily implementable for routine analysis. The accurate qualitative and quantitative analysis of PCs and isomers facilitates the discovery of biomarkers for exercise rehabilitation of patients with myocardial infarction.

The stray light induced redshift of absorption peaks of inorganic anions in the far ultraviolet region-an "artifact".

In the analytical process of spectrophotometry, the prerequisite for accurate qualitative and quantitative analysis is obtaining the intrinsic spectra of the analyte. However, the intrinsic properties of spectra can sometimes be masked by easily overlooked non-intrinsic factors, such as those from measuring instruments, leading to erroneous spectral identification. In this study, we documented an unusual redshift phenomenon in the far ultraviolet spectral region. With a spectrophotometer under the nitrogen atmosphere, we selected 14 representative inorganic anions and investigated their absorption spectral behaviors at different optical pathlengths and concentrations. It was intriguing to observe that the absorption peaks with maximum absorption wavelengths below a watershed wavelength of 200 nm underwent a redshift as pathlength and concentration increased, while those above 200 nm did not exhibit a significant redshift phenomenon. In-depth formula simulations and experimental verifications demonstrated that this peculiar spectral behavior was caused by unavoidable stray light in the spectrophotometer. Some methodological and instrumental recommendations are given in the paper. Our study results may serve as a reminder to carefully identify non-intrinsic phenomena when studying absorption spectra in the far ultraviolet region, and provide guidance on spectral corrections in scientific research and practical applications.

Chemical profiling of Simiao pill and quantification of main effective constituents in it by ultra-high-performance liquid chromatography coupled with Q Exactive Orbitrap and triple quadrupole mass spectrometry.

Simiao pill is one of the most commonly used prescriptions in traditional Chinese medicine for the treatment of hyperuricemia and gout. However, methods based on more accurate and comprehensive qualitative and quantitative analyses of the active ingredients are not yet perfect due to limited methodology. This not only hinders the elucidation of the pharmacological mechanism of Simiao pill, but also its comprehensive clinical development and utilization. In this study, we employed ultra-high-performance liquid chromatography-Q Exactive Orbitrap-mass spectrometry technology to perform rapid analysis and identification of the chemical constituents in Simiao pill. A total of 101 chemical components were identified, including 26 alkaloids, 15 terpenoids, 11 flavonoids, eight steroids, six fatty acids, five limonoids, four saponins, five phenylpropanoids, and 21 other compounds. In addition, we established a new method by high-throughput ultra-high-performance liquid chromatography-Q Exactive Orbitrap-mass spectrometry combined with ultra-high-performance liquid chromatography-triple quadrupole-tandem mass spectrometry technology for quantification of 14 main active ingredients, such as adenosine (1), phellodendrine (2), mangnoflorine (3), β-ecdysterone (4), 25R-inokosterone (5), 25S-inokosterone (6), jatrorrhizine (7), palmatine (8), chikusetsu saponin IVa (9), limonin (10), atractylenolide III (11), atractylenolide I (12), obacunone (13), and atractylenolide II (14) in Simiao pill. This work laid a foundation for further analysis and quality control of effective components in Simiao pill.

Quantitative analysis method of laser-induced breakdown spectroscopy based on temperature iterative correction of self-absorption effect

Laser-induced breakdown spectroscopy (LIBS) is an ideal real-time on-line method of detecting minor elements in alloys. However, in the case of laser-produced high-density plasma, the self-absorption is usually an undesired effect because it not only reduces the true line intensity, leading the line intensity to become nonlinear with the increase of emitting species content, but also affects the characterization parameters of the plasma, and finally affects the accuracy of quantitative analysis. Since the plasma electron temperature <inline-formula><tex-math id="Z-20240228161235">\begin{document}$(T)$\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="5-20231541_Z-20240228161235.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="5-20231541_Z-20240228161235.png"/></alternatives></inline-formula>, radiation particle number density and absorption path length (<i>Nl</i> ) determine the degree of self-absorption and affect the corrected spectral line intensity, a new self-absorption correction method is proposed based on temperature iteration. The initial <i>T</i> is obtained by using this method through spectral line intensity, and the self-absorption coefficient SA is calculated based on the initial <i>Nl</i> parameter to correct the spectral line intensity. Then a new <i>T</i> is obtained from the new spectral line intensity and the new SA is calculated to further correct the spectral line intensity. Through continuous calculation and correction of these two parameters, self-absorption correction is finally achieved. The experimental results of alloy steel samples show that the linearity of Boltzmann plot is increased from 0.867 without self-absorption correction to 0.974 with self-absorption correction, and the linear correlation coefficient <i>R</i><sup>2</sup> of the single variable calibration curve for Mn element increases from 0.971 to 0.997. The relative error of elemental content measurement is improved from 4.32% without self-absorption correction to 1.23% with self-absorption correction. Compared with the commonly applied self-absorption correction methods, this method has obvious advantages of simpler programming, higher computation efficiency, and its independence of the availability or accuracy of Stark broadening coefficients. Moreover, this method can directly obtain the radiation particle number density and absorption path length, which is beneficial to the diagnosis and quantitative analysis of plasma.

Accurate prediction analysis of steel alloy elements by femtosecond laser-ablation spark-induced breakdown spectroscopy and out-of-bag random forest regression

Femtosecond laser-ablation spark-induced breakdown spectroscopy (fs-LA-SIBS) and out-of-bag random forest regression (OOB-RFR) were developed for accurate quantitative analysis of the elements manganese (Mn), chromium (Cr), and nickel (Ni) in steel alloys.

Power-loss methodology for a compressor cascade at various Reynolds numbers and its validation

Finding ways to identify and quantify the losses from various sources in turbomachinery is significant for understanding the physical loss mechanisms and improving aerodynamic performance. However, traditional loss-assessment methods fail to reveal the local losses and decouple the flow field. In this paper, a new power-loss methodology is proposed. This methodology defines local and accumulated power losses, and a new method of averaging the total outlet pressure is presented. This establishes a direct relationship between the well-known total pressure loss and the accumulated power loss. The method was verified based on experimental results, the Reynolds-averaged Navier–Stokes equations, and large-eddy simulations of a compressor cascade at various Reynolds numbers. By applying this method, the boundary-layer loss, separation loss, and trailing-edge mixing loss of the compressor cascade were successfully distinguished and quantitatively accounted for. The method has been shown to be a valuable tool for understanding and quantifying the losses experienced in different flow regimes. In conclusion, the power-loss methodology demonstrates the potential for accurate quantitative analysis of local and global loss generation, the investigation of physical mechanisms, and the development of physical models for diverse complex flows beyond just the compressor cascade flow.

Influence of coupled dissolution-precipitation processes on the pore structure, characteristics, and evolution of tight sandstone: A case study in the upper Paleozoic reservoir of Bohai Bay Basin, eastern China

Due to the limitations of pore throat characterization techniques, in-depth studies on the evolution and influencing variables of tight sandstone reservoirs remain lacking, despite the importance of pore structure in evaluating their storage and seepage capacities. In this study, the effect of coupled dissolution–precipitation on the heterogeneity of the pore structure of tight sandstone was investigated using advanced techniques in conjunction with traditional geochemical analyses. The primary reasons for the variability in tight sandstone pore structure were different diagenetic processes and tectonic evolution. In tight sandstones, numerous burial phases led to a significant loss of porosity. However, tight sandstones that have been successively leached by meteoric water and deep burial organic acid have improved secondary pore space due to Yanshan tectonic uplift and Himalayan tectonic burial. The redistribution or blockage of pore space can occur as a result of dissolved material migrating and re-precipitating in tight sandstones that have been deeply buried and altered by organic acidic fluids. Furthermore, nuclear magnetic resonance cryoporometry and nuclear magnetic resonance experiments were used to provide precise and accurate quantitative analysis for discussing the evolution of pore structure by complex dissolution–precipitation process within the pore scale. The formation of good pore structure was mainly dependent on the increase in pore volume generated by dissolution in the submicron and micron range (less than 10 μm). Due to interfacial energy effects, authigenic minerals precipitated preferentially in macropores, resulting in a preponderance of microporosity and small changes in porosity but at least an order of magnitude reduction in permeability. This study provides a reliable reference for genesis analysis and evaluation of tight sandstones as well as a new perspective for understanding the formation and evolution of complex pore structures.

Quantitative Detection of Thitsiol and Urushiol as Markers from the Gluta usitata Lacquer Tree Using HPLC.

Lacquer sap has been traditionally used in coatings and artwork. Suitable types of lacquer are required to preserve and restore artifacts. Recently, unsuitable cashew nut shell liquid (CNSL) has often been mixed with lacquer sap, so it is necessary to identify the characteristics of lacquer sap by the production area. However, research is still focused on urushiol and laccol. In this study, Myanmarese lacquer sap collected from Gluta usitata, which contains thitsiol as the main component, was analyzed by HPLC to quantify thitsiol using the standards 3-(10-phenyldecyl) benzene-1,2-diol (thitsiol 16) and 3-(8Z,11Z-pentadecadienyl)-benzenediol (urushiol 15:2) as markers, and calibration curves were plotted. The coefficients of determination (R2) for thitsiol 16 and urushiol 15:2 were 0.9985 and 0.9983, respectively. In addition, a blind test was conducted to confirm that accurate quantitative analysis was possible even when Myanmarese lacquer was mixed with lacquer from another production area, which contained urushiol as the main component, and CNSL, which contained cardol, a completely different catechol. Quantitative analysis of thitsiol 16 and urushiol 15:2 in Myanmarese lacquer using HPLC can be used to evaluate the quality of lacquer sap and for more sophisticated activities such as restoration by classifying differences in lacquer sap by the production area.

Dosage-sensitive and simultaneous detection of multiple small-molecule pollutants in environmental water and agriproducts using portable SERS-based lateral flow immunosensor

The co-contamination of pesticide residues and mycotoxins in agricultural products is a global concern, with the potential for cumulative and synergistic damaging effects, imposing substantial health and economic burdens to the public. The dosage-sensitive and simultaneous detection of multiple pollutants, with a heightened sensitivity in real samples, poses a significant demand and challenge. Herein, we propose a portable detection method integrating surface-enhanced Raman scattering (SERS)-with lateral flow immunoassay (LFIA), offering high sensitivity and multiplex analysis capabilities. This approach enables the simultaneous detection of imidacloprid (IMI), pyraclostrobin (PYR) and aflatoxin B1 (AFB1) through a single test strip. Utilizing the immune-specific binding between antigen and antibodies, we immobilised antibody- conjugated SERS nanotags on three test lines of the strips to generate Raman signal amplification in the proposed biosensor. Accurate quantitative analysis was performed by measuring the SERS signal intensity on the test lines. The limits of detection were 8.6 pg/mL for IMI, 97.4 pg/mL for PYR and 8.9 pg/mL for AFB1, exhibiting sensitivities 12-fold, 102-fold and11-fold higher than the colorimetric signals, respectively. Importantly, the SERS-LFIA immunosensor demonstrated robust performance when applied to real samples, yielding recoveries ranging from 86.16 % to 115.0 %, with relative standard deviation values below 8.67 %. These results underscore the excellent stability, high selectivity and reliability the proposed SERS-LFIA immunosensor. Consequently, it holds promise for the detection of multiple pesticides and mycotoxins in both environmental and agricultural samples.

Multifunctional Probe Based on "Chemical Antibody-Aptamer" for Noninvasive Detection of PD-L1 Expression in Cancer.

Immune checkpoint inhibitors (ICIs) therapy based on programmed cell death ligand 1 (PD-L1) has shown significant development in treating several carcinomas, but not all patients respond to this therapy due to the heterogeneity of PD-L1 expression. The sensitive and accurate quantitative analysis of in vivo PD-L1 expression is critical for treatment decisions and monitoring therapy. In the present study, an aptamer-based dual-modality positron emission tomography/near-infrared fluorescence (PET/NIRF) imaging probe was developed, and its specificity and sensitivity to PD-L1 were assessed in vitro and in vivo. The probe precursor NOTA-Cy5-R1 was prepared by using automated solid-phase oligonucleotide synthesis. PET/NIRF dual-modality probe [68Ga]Ga-NOTA-Cy5-R1 was successfully synthesized and radiolabeled. The binding specificity of [68Ga]Ga-NOTA-Cy5-R1 to PD-L1 was evaluated by flow cytometry, fluorescence imaging, and cellular uptake in A375-hPD-L1 and A375 cells, and it showed good fluorescence properties and stability in vitro. In vivo PET/NIRF imaging studies illustrated that [68Ga]Ga-NOTA-Cy5-R1 can sensitively and specifically bind to PD-L1 positive tumors. Meanwhile, the rapid clearance of probes from nontarget tissues achieved a high signal-to-noise ratio. In addition, changes of PD-L1 expression in NCI-H1299 xenografts treated with cisplatin (CDDP) were sensitivity monitored by [68Ga]Ga-NOTA-Cy5-R1 PET imaging, and ex vivo autoradiography and western blot analyses correlated well with the change of PD-L1 expression in vivo. Overall, [68Ga]Ga-NOTA-Cy5-R1 showed notable potency as a dual-modality PET/NIRF imaging probe for visualizing tumors and monitoring the dynamic changes of PD-L1 expression, which can help to direct and promote the clinical practice of ICIs therapy.

Effect of laser energy on temporal evolution of self-absorption at different air pressures

The self-absorption effect is one of the key factors influencing the accuracy of quantitative analysis. Laser energy is the key influencing factor of laser-induced breakdown spectroscopy (LIBS), and the mechanism of its influence on temporal evolution of self-absorption under different air pressures is still not fully understood due to complex physical processes. In this study, the temporally resolved spectra of Cu I 521.82 nm were acquired from the direction of laser incidence and the influence of laser energy on the temporal evolution of self-absorption in a low-vacuum (at pressures of 105, 104 and 103Pa) and high-vacuum (at pressures of 10, 10−1 and 10−3Pa) environment was studied. The experimental results indicate that the self-absorption effect of spectral line Cu I 521.82 nm is enhanced with an increase in delay time and laser energy in both high-vacuum and low-vacuum environments in this study. This is because increasing the delay time and laser energy leads to an increase in plasma column density. An intriguing phenomenon observed in this experiment is that at a pressure of 105Pa, the self-absorption of Cu I 521.82 nm initially increases but eventually weakens with laser energy, while at air pressures of 104Pa and 103Pa the self-absorption monotonically weakens with increasing laser energy during the measurement. This is because temporal evolution of plasma at 104Pa and 103Pa is significantly faster than that at 105Pa, and an increase in laser energy can delay the enhancement of self-absorption, the self-absorption has rapidly evolved to decrease with laser energy during spectral measurement at air pressure of 104 Pa and 103 Pa. This work is helpful in understanding the influence of air pressure and laser energy on the self-absorption effect of spectral lines and optimizing experimental parameters, and provides a reference for LIBS application.

Dual-energy computed tomography for improved contrast on a polyphase graphitic ore

Proper ore characterisation is essential for understanding ore deposits and developing efficient mineral processing flow sheets. Conventional mineralogical and chemical techniques are usually used to study ores, but they can be destructive and, in some cases, provide only 2D information. Computed tomography (CT) is an emerging technology in the raw materials sector enabling the non-destructive 3D analysis of the ore mineralogy and microstructure. However, single-energy CT (SECT) has some limitations concerning the accurate imaging and differentiation of polyphase geomaterials comprising a broad range of attenuation properties. By contrast, dual-energy CT (DECT) uses two different X-ray energies to acquire data, which can be used to distinguish between materials with similar attenuation properties. This study explored the application of DECT for the analysis of a polyphase graphitic ore. A sequential fusion approach was utilized to combine data obtained from different X-ray energy scans at high spatial resolution, and varying weighting factors were applied to determine the optimal contribution of each energy level and spectrum. Both, SECT and DECT datasets were quantitatively evaluated based on the contrast-to-noise-ratio (CNR) and Q factor. The findings demonstrate that DECT significantly improves image contrast compared to SECT while further increases image sharpness. As a result, DECT may enable more accurate segmentation and, therefore, more accurate quantitative 3D analysis of graphite ores.

A single atom cobalt anchored MXene bifunctional platform for rapid, label-free and high-throughput biomarker analysis and tissue imaging

Few of single-atom materials have been served as platform to analyze small molecules for surface assisted laser desorption/ionization mass spectrometry (SALDI-MS). Herein, a novel single Co atom-anchored MXene (Co–N–Ti3C2) is prepared to achieve enhanced SALDI-MS and mass spectrometry imaging (MSI) performance for the first time. The Co–N–Ti3C2 films were prepared by a simple in situ self-assembly strategy to generate an efficient SALDI-MS platform. Compared to typical inorganic/organic matrices, Co–N–Ti3C2 films exhibit superior performance in small molecules detection with ultra-high sensitivity (LOD at amol level), excellent repeatability (CV <4%), clean background and wide analyte coverage, enabling accurate quantitative analysis of various low-concentration metabolites from 1 μL biofluid in seconds. Its usage efficiently enhanced SALDI-MS detection of various small-molecule biomarkers such as amino acids, succinic acid, itaconic acid, arachidonic acid, citrulline, prostaglandin E2, creatinine, uric acid, glutamine, D-mannose, cholesterol and inositol in positive ion mode. The blood glucose level in humans was successfully determined from a linearity concentration range (0.25–10 mM). Notably, the Co–N–Ti3C2 assisted SALDI-MSI enables study the spatial distribution of small molecules covering the range central to metabolomics at a high resolution on a tissue section. Furthermore, Co–N–Ti3C2 platform revealed a specific peak profile that distinguishes osteoarthritis (OA) from rheumatoid arthritis (RA) tissue. Density functional theory theoretical investigation revealed that single Co atoms anchored on Ti3C2 could highly enhanced the ionization ability of metabolites, resulting in high-sensitivity and heterogeneous metabolome coverage.

Quantitative Analysis of Ice Crystal Growth During Freezing of Dimethyl Sulfoxide Solutions Under Alternating Current Electric Fields.

During cryopreservation, the growth of ice crystals can cause mechanical damage to samples, which is one of the important factors limiting the quality of preserved samples. To enhance the preservation quality of biological samples, scholars have tried various engineering methods. Among them, an electric field is an essential factor affecting solution freezing. Dimethyl sulfoxide, as a commonly used cryoprotectant, can cause mechanical damage to cells due to ice crystals even when freezing at the optimal freezing rate. Water is a strongly polar dielectric material, and the applied alternating current (AC) electric field will affect the water freezing performance. Therefore, a quantitative study of ice crystal nucleation and growth during freezing of dimethyl sulfoxide solutions under different AC electric field conditions is needed to try to reduce ice crystal damage. We created a liquid-film device to approximate the ice crystal growth process as a two-dimensional image. The frequency of the AC voltage was set from 0 to 50 kHz. We measured the supercooling of the dimethyl sulfoxide solution under AC electric field conditions. As an objective and accurate quantitative analysis of the ice crystal growth process, we propose a Dilated Convolutional Segmentation Transformer for semantic segmentation of ice crystal images. It is concluded that the average area and the growth rate of single ice crystals decrease with increasing electric field frequency at a certain concentration of dimethyl sulfoxide solution. Lower concentrations of dimethyl sulfoxide solution in combination with an AC electric field can achieve similar ice suppression effects as when higher concentrations of dimethyl sulfoxide solution act alone. We believe that AC electric fields are expected to be an aid to cryopreservation and provide some theoretical basis and experimental foundation for its development.

Bearing performance degradation assessment using adversarial fusion convolutional autoencoder based on multi-source information

Bearing operation states will directly determine the performance of the equipment; thus, monitoring operation status and degradation indicators is the key to ensuring continuous and healthy operation of the equipment. However, most of the research uses single-source information data, which makes it difficult to model when dealing with multi-source information, complex data distribution, and noise. In this paper, a bearing performance degradation assessment method based on multi-source information is proposed to comprehensively utilize the data signals of different structures, spaces, types, and sources. First, the adversarial fusion convolutional autoencoder is constructed for obtaining the degradation index of the bearing, while the adversarial learning strategy is applied to achieve the effect of enhancing the robustness and sensitivity of the degradation indicators extracted by the network. Then the degradation index is input into the support vector data description to determine the fault anomalies of the degradation index adaptively and the fuzzy c-means algorithms to obtain the final rolling bearing performance degradation evaluation results. Through the verification results of two experiment datasets, it is found that the proposed model can achieve accurate evaluation and quantitative analysis of the performance degradation process of bearings. As a result, the entire network ensures the reconstruction accuracy of normal samples while simultaneously stretching the reconstruction error of abnormal samples to achieve accurate monitoring of degradation onset.

Monitoring the dynamic process of non-thermal plasma decontaminated water with Raman spectroscopy real-time analysis system

This study focuses on the target pollutant, indigo carmine (E132), employing Raman spectroscopy in conjunction with machine learning techniques. An accurate quantitative analysis model was developed to monitor the dynamic plasma decontamination process, utilizing the partial least squares (PLS). The PLS model exhibited excellent predictive performance, achieving adjusted determination coefficients (R2) of 0.9990 and root mean square error (RMSE) values of 0.0058 g/L for the training set, and 0.9730 and 0.0178 g/L for the test set. Real-time monitoring using Raman spectroscopy investigated the impact of discharge voltages, gas flow rates, and solution pH values on E132 degradation. Feedback control based on real-time data led to a 75 % improvement in degradation efficiency by adjusting discharge gas velocity and enhanced energy utilization through discharge time control. Furthermore, the study provided insights into the mechanisms of air plasma-based wastewater treatment. This research presents a convenient and efficient method for online pollutant analysis, optimizing plasma-based water treatment parameters, improving treatment effectiveness, and conserving energy. It lays the groundwork for integrating advanced control algorithms to achieve automated decontamination processes.

Usefulness of Quantitative Analysis Using Relative Electron Density-Based Image of Subsolid Nodule in Chest HRCT

To study the usefulness of quantitative analysis using the relative electron density-based image in the diagnosis of subsolid nodule by chest high-resolution CT. The phantom study measured the CT number(HU), relative electron density(%EDW) and maximum diameter of the nodules by placing artificial nodules in the chest phantom. The patient study was conducted on 172 patients with subsolid nodules from April 2022 to January 2023. The volume and diameter of subsolid nodules in the CT number-based image and relative electron density-based image were measured separately after dividing the two groups: mixed ground-glass nodule and pure ground-glass nodule. The correlation studied between measuring the CT number(HU) and relative electron density(%EDW) by setting the region of interest. The CT number(HU) and diameter values in the phantom study were not significantly different from the actual values of the artificial nodules.(P&gt;0.05) As a result of the patient study, the volume and diameter of subsolid nodules were increased in the relative electron density-based image compared to the CT number-based image for both the mixed ground-glass nodule and pure ground-glass nodule groups.(P&lt;0.05) The CT number(HU) and relative electron density(%EDW) showed a strong positive correlation in both the phantom and patient study.(P&lt;0.05) Providing visual imaging information using CT number-based and relative electron density-based images simultaneously can offer many advantages in establishing future treatment plans through accurate quantitative analysis of subsolid nodules.