Analytical Lines Research Articles

Reconsidering the Science and Semantics of Intelligence Analysis

Intelligence analysis can benefit from a rigorous application of scientific method and the borrowing of frameworks from the social sciences, but it cannot be defined entirely in such terms that are extrinsic to the field. There is a process of “sense-making,” involving the production and negotiation of meaning through the exchange of signs and their signification, as the analyst mediates between the world of the target set and the world of the policymaker. That process is fundamentally and irreducibly subjective, intrinsic to the human experience that is deeply embedded in analysis, and it takes place primarily within the medium of verbal language. A semiotic approach would be better suited for understanding the ways that analysts navigate the layers of meaning that accrue to events within their local contexts, the grammar or rhetoric of tropes that shape analytical lines, and the socially constructed rules that guide policy debates.

Nontwist field line mapping in a tokamak with ergodic magnetic limiter.

For tokamaks with uniform magnetic shear, Martin and Taylor have proposed a symplectic map which has been used to describe the magnetic field lines at the plasma edge perturbed by an ergodic magnetic limiter. We propose an analytical magnetic field line map, based on the Martin-Taylor map, for a tokamak with arbitrary safety factor profile. With the inclusion of a nonmonotonic profile, we obtain a nontwist map which presents the characteristic properties of degenerate systems, such as the twin islands scenario, shearless curve, and separatrix reconnection. We estimate the width of the islands and describe their changes of shape for large values of the limiter current. From our numerical simulations about the shearless curve, we show that its position and aspect depend on the control parameters.

X-ray Fluorescence Analysis of Waste Sm-Co Magnets: A Rational Approach

Determination of the chemical composition of waste Sm-Co magnets is required for their efficient recycling. The non-stereotypical composition of said magnets makes an analysis extremely challenging. X-ray fluorescence spectrometry is a promising analytical tool for this task. It offers high accuracy and simplicity of sample preparation as it does not require sample dissolution. However, a serious limitation of X-ray fluorescence analysis is the spectral interference of matrix elements and impurities. In this work, a two-stage technique has been developed for the determination of the main components (Sm, Co) and impurities (Fe, Cu, Zr, Hf, Ti, Ni, Mn, Cr) in samples of spent samarium–cobalt magnets using wavelength dispersive X-ray fluorescence spectrometry. In order to overcome the main limitation of the chosen method and to maximize its capabilities of qualitative and quantitative analysis, we propose an approach to the selection of analytical lines and experimental conditions, as well as a preparation method for the calibration standards. The obtained results have been shown to have a good correlation with ICP-OES. The limits of detection are in the range of 0.001–0.02 wt%, and the limits of quantification are 0.003–0.08 wt%.

Sensitive determination of rare earth elements in liquid samples by spatial confinement assisted surface enhanced laser-induced breakdown spectroscopy

The rapid determination of rare earth elements (REEs) in liquid samples holds significant importance for various applications such as the exploration and development of REEs resources, quality control of the extraction process, regeneration and recycling of REEs, and monitoring of nuclear industry wastewater. This study employed spatial confinement assisted surface-enhanced laser-induced breakdown spectroscopy (SC-SE-LIBS) for REEs determination in liquid samples. Investigations were conducted into the impact of different material substrates, sample pretreatment methods, and spatial confinement cavity diameters on detection performance. The results reveal that the graphite substrate yields superior spectral signal intensity compared to other materials (Zn, Al, and Ni). The groove-constrained liquid–solid conversion (GCLSC) pretreatment method significantly enhances spectral stability and detection accuracy. The most favorable signal enhancement is achieved using a cylindrical spatial confinement cavity (CSCC) with an 8 mm diameter. Employing the optimized experimental conditions, quantitative analysis of six REEs (La, Ce, Pr, Nd, Gd, Y) in liquid samples was performed using analytical lines at wavelengths of La Ⅱ 394.91 nm, Ce Ⅱ 401.24 nm, Gd Ⅱ 404.99 nm, Nd Ⅱ 406.11 nm, Pr Ⅱ 417.94 nm, and Y Ⅱ 488.37 nm. The obtained calibration curves exhibited R2 fit coefficients above 0.99, with corresponding limits of detection (LoDs) of 0.021 μg/mL, 0.104 μg/mL, 0.312 μg/mL, 0.241 μg/mL, 0.036 μg/mL, and 0.045 μg/mL, respectively.

Spectroscopy from quantum dynamics: a mixed wave function/analytical line shape functions approach

Quantum dynamics is the natural framework in which accurate simulation of spectroscopy of nonadiabatically coupled molecular systems can be obtained. Even if efficient quantum dynamics approaches have been developed, the number of degrees of freedom that need to be considered in realistic systems is typically too high to explicitly account for all of them. Moreover, in open-quantum systems, a quasi-continuum of low-frequency environment modes need to be included to get a proper description of the spectral bands. Here, we describe an approach to account for a large number of modes, based on their partitioning into two sets: a set of dynamically relevant modes (so-called active modes) that are treated explicitly in quantum dynamics, and a set of modes that are only spectroscopically relevant (so-called spectator modes), treated via analytical line shape functions. Linear and nonlinear spectroscopy for a realistic model system is simulated, providing a clear framework and domain of applicability in which the introduced approach is exact, and assessing the error introduced when such a partitioning is only approximate.

Parameter identification method of nonuniform and under-sampled blade tip timing based on extended DFT and compressed sensing

Vibration amplitude and frequency are the two most important indicators that characterize the health status of high-speed rotating blades, but the signal obtained by blade tip timing (BTT) technology, one of the best rotating blade vibration monitoring methods, is seriously nonuniform and under-sampled, which makes these two indicators difficult to identify. In view of this problem, the paper proposes a parameter identification method for the nonuniform and under-sampled BTT signal based on extended Discrete Fourier transform and compressed sensing (CS), with the Fourier integral transformation as the goal. It realizes the frequency analysis of nonuniform under-sampled signals by constructing and optimizing the transformation basis function instead of the exponential basis in the traditional FFT transformation in the extended frequency range, and then constructs a CS model through the obtained blade vibration frequency. The complete waveform of the blade vibration is restored by using a small number of under-sampled signals, thus obtaining the blade vibration amplitude and vibration frequency. On the one hand, the method proposed in this paper breaks through the limitation of Nyquist’s sampling theorem, and the number of analytical spectral lines is no longer limited to the number of sampling points, which improves the frequency resolution. On the other hand, only a small number of measurement signals can be reconstructed to achieve a complete vibration signal. The feasibility and reliability of the proposed method are verified by mathematical modeling, simulation analysis, and experimental testing. The results indicate that when the number of sensors is greater than or equal to four, the time domain and frequency domain signals of blade vibration can be accurately analyzed based on the proposed method, the vibration amplitude error is less than 0.01 mm, the frequency error is less than 0.1 Hz, and it has good anti-interference performance.

A portable piezoelectric transformer microplasma optical emission spectrometry for the determination of mercury

Miniaturization of microplasma-based optical emission spectrometry (OES) has gained great attention due to the advantages of simplicity, compactness, and cost-effectiveness. However, the energy feed-in affects the generation, maintenance and excitation capability of discharge microplasma, which also limits the potential of microplasma for portable OES. Herein, we report that a piezoelectric transformer-driven microplasma (PTM) was first utilized as an excitation source of miniature OES for quantitative analysis of mercury (Hg). A piezoelectric transformer (PT) can directly convert mechanical energy into electrical energy and emanate plasma at the wire of the output distal end, which provides a path to construct microplasma devices without an extra high voltage power supply. A syringe needle acted as another ungrounded electrode, which was hung a proper distance below the PT output, to generate glow discharge. Hg was effectively converted into volatile species by hydride generation (HG) and transferred into PTM through the syringe needle by carrier gas (argon). Under the optimized experimental conditions, Hg was detected in the range of 10–1000 μg/L, with a limit of detection (LOD) of 2.8 μg/L by using the analytical line of Hg 253.65 nm. The accuracy and practicability of the proposed method were validated by analyzing the Certified Reference Materials (CRMs, dogfish liver and soil) and real water samples with satisfied results. In addition to no need of high voltage power supply and closed circuit, this HG-PTM-OES system features low power consumption, small size, light weight, sturdiness and high safety, which would be beneficial to fabricate a miniaturized and portable device for on-site environmental monitoring.

Dynamical excitation of spin-orbit coupled spin-1 Bose-Einstein condensate in a narrow box trap

We demonstrate the dynamics of a spin-1 ferromagnetic Bose-Einstein condensate (BEC) with Rashba spin-orbit (SO) coupling in a narrow square box trap when an obstacle potential is moving in it. The ground-state energy would be enhanced with the box trap becomes narrower. From the Bogoliubov analytical excitation spectrum lines, we obtain the dependence of critical excitation velocity and momentum on the trap geometry under different SO coupling. Numerically, when the obstacle moves along the direction of plane wave ground state, in addition to spin-density waves being excited periodically, a long density belt accompanied by density island chain is found ahead of the obstacle. Such density distribution is mainly determined by the narrow box trap. A series of density islands arranged more closely are generated as the obstacle moves along opposite direction. There exists another velocity threshold for different density excitation under a larger SO coupling.

Recent advances in ultra‐trace determination of uranium in natural water using total reflection X‐ray fluorescence (TXRF) spectrometry

AbstractThis review article describes some of the recent advances in ultra‐trace determination of uranium in various natural water bodies such as drinking water, underground water, seawater, etc. using total reflection x‐ray florescence (TXRF) spectrometry. Uranium is one of the most hazardous element having chemical as well as radio‐toxicity. However, due to its low concentration in water samples, direct determination is seldom possible in samples with high salt content. Various sample preconcentration and selective extraction techniques for uranium such as solvent extraction, dispersive liquid–liquid micro extraction, solid phase extraction, and membrane based preconcentration methods are summarized in this article. TXRF is a very versatile micro‐analytical technique with detection limits in picogram range and having multielemental analysis capability. TXRF determination of uranium using U Lα as the analytical line has many analytical challenges and difficulties, mainly due to the severe interference with Rb and Br, both are commonly available in natural water samples. This article highlights some of these challenges, along with the advantages and disadvantages of the different sample preparation techniques used so far for uranium determination in natural water samples by TXRF.

Optical and thermal characterization of pure CuO and Zn/CuO using laser-induced breakdown spectroscopy (LIBS), x-ray fluorescence (XRF), and ultraviolet–visible (UV–Vis) spectroscopy techniques

We present elemental analysis and thermal characterization of pure and two different concentrations of zinc-doped copper oxide (CuO) samples using different analytical techniques. The quantitative as well as qualitative investigations, were performed by incorporating calibration-free laser-induced breakdown spectroscopy (CF-LIBS) technique. The plasma was generated on the samples surface by focusing a first harmonic of Nd: YAG laser of 1064 nm wavelength and the time-integrated emission spectra was achieved through a set of five spectrometers equipped with a charge-coupled-device. The acquired optical emission spectra from laser-generated plasma show different concentrations of zinc and copper in different samples which are consistent with their percentage composition measured during the sample synthesis. Using LIBS emission analytical lines, the Boltzmann technique was utilized for estimating the excitation temperature, while the number density was evaluated using the well-known Stark broadening line profile method. Besides, the CF-LIBS elemental analysis was validated by the x-ray fluorescence technique. For the optical study, ultraviolet–visible spectroscopical analysis was performed to find the bandgap of pure and zinc-doped copper oxide samples and consequently, variation in bandgap was studied with the growth of zinc doping. In addition, the thermal properties of the samples were analyzed using the beam deflection spectroscopy technique. The results shows that thermal diffusivity () and thermal conductivity (), increased with an increase in zinc concentration.

Monazite from lithium-bearing pegmatites of the Lipovskoye vein field, Middle Urals (composition and chemical dating)

The relevance of the research is due to the need to improve the method of chemical dating as applied to high-thorium accessory minerals, which are difficult to study by isotope research methods. Purpose of the research is to study the chemical composition of monazite from lithium-bearing granite pegmatites of the Lipovskoye vein field and to determine their age. Research methodology. The quantitative analysis of the chemical composition of monazite was performed on a CAMECA SX 100 electron probe microanalyzer (IGG UB RAS, Ekaterinburg). Measurement conditions: accelerating voltage 15 kV, current strength 250 nA, electron beam diameter 2 μm. The pressure in the sample chamber is 2 ⋅ 10–4 Pa. The spectra were obtained on tilted wave spectrometers, the intensity was measured using analytical lines: Th Ma, U Mb, Pb Ma, Y La, Si Ka, Ca Ka, P Ka, Ce La, La La, Pr Lb, Nd La, Sm Lb, Dy La, Gd Lb. Standard samples: ThO2 , UO2 , Pb2 P2 O7 , diopside, synthetic rare-earth phosphates. The intensity measurement time at the peak for Th is 180 s, U is 100 s, and Pb is 500 s (240 s on one and simultaneously 260 s on another spectrometer), for Y and Si 20 s each, for the other elements 10 s; on the background – two times less. The detection limits for Th, U, and Pb in monazite are 290, 350, and 64 ppm, respectively. The oxygen content was determined under the assumption of the stoichiometry of the composition. Results. It has been established that monazite belongs to the cerium variety and is characterized by high contents of thorium (ThO2 up to 23.6 wt. %) and uranium (UO2 up to 2.5 wt. %). At the same time, cheralite-type isomorphism is realized in phosphate. In a closed Th–U–Pb-system (β = 0.92–0.97), according to the results of chemical dating (according to 20 analyses), monazite-(Ce) shows a weighted average age of 243 ± 7 Ma. When plotting the dependence (ThO2 + UO2 eq) – PbO, the points fall on one isochrone. Calculation of the age from the slope of the isochron gave a dating of 242 ± 17 Ma, MSWD = 0.21, probability = 1.00. Conclusion. It has been established that accessory monazite from lithium-bearing granitic pegmatites of the Lipovskoye vein field (Middle Urals) is of Triassic age. Apparently, this dating shows the time of the secondary transformation of lithium-bearing granitic pegmatites, which are often tectonized, and in some places even boudinaged.

Tungstates of the Boyovskoye tungsten deposit (Southern Urals)

The relevance of the work is due to the need for a mineralogical study of tungsten deposits in the Ural region, which have been mined since the end of the 19th century. The purpose of the work is the diagnostics and detailed description of tungstates from the Boyovskoye tungsten deposit located on the border of the Chelyabinsk and Sverdlovsk regions in the Southern Urals. Analytical studies were carried out in the Laboratory of Physical and Chemical Research Methods of the Institute of Geology and Geochemistry, UB RAS, Ekaterinburg. The chemical composition of minerals was analyzed in polished sections on a CAMECA SX 100 microanalyzer. Measurement conditions: accelerating voltage 15 kV, current 150 nA, electron beam diameter 2 μm. The pressure in the sample chamber is 2 ⋅ 10–4 Pa. The spectra were obtained on tilted wave spectrometers; the intensity was measured from analytical lines. Standard samples: scheelite, wolframite, galena, rutile and chromite. Raman spectra of minerals were obtained using a LabRam HR Evolution spectrometer (Horiba Scientific). A red laser, 532 nm, was used for analysis. As a result of the work, new data on the chemical composition of hubnerite and scheelite were obtained and their Raman spectra were presented. For the first time for the Boyovskoye tungsten deposit, a reliable diagnosis and description of lead tungstate – stolzite was made. The mineral was found in samples with veined quartz in association with muscovite, fluorite, hubnerite and scheelite. It fills cracks and voids in hubnerite, rarely overgrows scheelite or fills cracks in scheelite. It is a later mineral in relation to hubnerite and scheelite. Its chemical composition contains impurities of manganese, calcium, iron and titanium. The stolzite found by us is a mineral of the oxidation zone and, most likely, was formed due to the weathering of wolframite and galena, which is also present in quartz veins.

Quantitative elemental analysis of bismuth brass with target-enhanced orthogonal double-pulse LIBS combined with variant one-point calibration.

Self-absorption and unknown transition probabilities of the analytical lines hinder the accurate quantitative elemental analysis of bismuth brass with conventional calibration-free laser-induced breakdown spectroscopy (LIBS). In this work, target-enhanced orthogonal double-pulse LIBS combined with a variant one-point calibration method was used to solve this problem and realize quantitative elemental analysis of bismuth brass with a relative error of less than 4%. This approach is able to reduce the influence of self-absorption and capable of using analytical lines with unknown transition probabilities while using a calibration-free algorithm, which is helpful for accurate quantitative elemental analysis of bismuth brass and other samples.

Study of matrix interference in the determination of selenium and tellurium in ICP-AES in metallurgical materials

The content of selenium and tellurium used in steels and alloys as alloying additives is strictly regulated by the current state standards. The methods of analysis used in state standards are often lengthy and laborious and do not provide their simultaneous determination. Development of alternative methods for the determination of selenium and tellurium in metallurgical materials using modern analytical equipment is an urgent goal. The method of atomic emission spectrometry with inductively coupled plasma (ICP-AES) is widely used in analysis of metallurgical materials. However, the components of the sample base can significantly affect the results of ICP-AES analysis. We present the results of theoretical and experimental study of the effect of the components of the base of samples of metallurgical materials (iron, nickel, chromium, molybdenum, cobalt, copper, tungsten) on the spectral analytical lines of selenium and tellurium. Thermodynamic modeling was used for theoretical prediction of the processes occurring during atomization of the analyzed solutions in argon plasma. It is shown that matrix non-spectral noise on the selenium line is attributed to chromium (at chromium concentrations above 50 mg/dm3), whereas the matrix non-spectral noise on the tellurium line is not observed. It is also shown experimentally that the spectral lines of selenium and tellurium are not free from spectral overlaps attributed to macrocomponents (iron, nickel, chromium, molybdenum, cobalt, copper and tungsten). To reduce the limits of detection and improve the reliability of ICP-AES determination of selenium and tellurium, it is necessary to separate them from the components of the sample base.

The reliability of analytical reference lines for determining esthetically pleasing lip position: An assessment of consistency, sensitivity, and specificity

This study aimed to identify a simple yet reliable soft-tissue parameter for the clinical determination of esthetic lip position by investigating the most consistent reference lines and assessing their sensitivity and specificity. A total of 5745 records from Chinese patients aged>18 years were screened. In part I of the study, lateral view photographs of 96 subjects (33 males, 63 females) with esthetic facial profiles were selected. The profile esthetics of each photograph was first scored by 52 dental students, followed by 97 laypeople on a 5-point attractiveness scale. For the top 25% of photographs with the highest score for each sex (8 males, 16 females), the consistency of 6 commonly used reference lines were assessed to determine the esthetic lip position. In part II of the study, lip positions relative to Steiner's (S) and Ricketts' (E) lines in the profile photographs of 86 patients (43 males, 43 females) deemed to have an esthetically unpleasing profile were compared with those in 86 Chinese movie star idols (43 males, 43 females). In part I of the study, the S, E, and Burstone's (B) lines exhibited the lowest standard deviations for the upper and lower lips. B line was excluded from further analysis because of its higher mean absolute values, and S and E lines were used for the subjective assessment in part II of the study. In part II, the S line showed a sensitivity of 86.0% and 86.0% and a specificity of 81.4% and 83.7% for males and females, respectively. In contrast, the E line presented a sensitivity of 88.4% and 93.0% and a specificity of 79.1% and 74.4% for males and females, respectively. S, E, and B lines were the most consistent soft-tissue parameters among both sexes; however, because of the smaller absolute values, the S line would be more convenient among the 3 for a quick clinical assessment of lip position. Moreover, the performance of both S and E lines was similar among both sexes, which supports using these lines in assessing the esthetic lip position.

Discrete analytical objects in the body-centered cubic grid

We propose a characterization of discrete analytical spheres, planes and lines in the body-centered cubic (BCC) grid, both in the Cartesian and in the recently proposed alternative compact coordinate system, in which each integer triplet addresses some voxel in the grid. We define spheres and planes through double Diophantine inequalities and investigate their relevant topological features, such as functionality or the interrelation between the thickness of the objects and their connectivity and separation properties. We define lines as the intersection of planes. The number of the planes (up to six) is equal to the number of the pairs of faces of a BCC voxel that are parallel to the line.

Mathematical Assessment of Combined Standard Uncertainty of Measurements in Using Concentration Ratio Calibration in Inductively Coupled Plasma Atomic Emission Spectrometry

The mathematical assessment of effect of uncertainty components on measurement results in using concentration ratio calibration in inductively coupled plasma atomic emission spectrometry was performed. Formulas for the calculation of the relative standard uncertainty for different components were derived. It was shown that, in different scenarios of using concentration ratio calibration, the combined standard uncertainty basically depends on the repeatability of the determination of the intensity ratio of the analytical line of a test element to the line of the main matrix component of the sample

Pavlinsky Geliy Veniaminovich (1935–2023)

Pavlinsky Geliy Veniaminovich (1935–2023)

Improving LIBS analysis of non-flat heterogeneous samples by signals mapping.

Heterogeneous material analysis by the laser-induced breakdown spectroscopy (LIBS) technique is challenging in real practice due to requirements for representative sampling and non-flat surfaces of the samples. Methods complementary to LIBS (plasma imaging, plasma acoustics, sample surface color imaging) have been introduced to improve zinc (Zn) determination in soybean grist material by LIBS. The detailed statistical study revealed that atomic/ionic lines emission and other LIBS signals were distributed normally except for acoustics signals. The correlation between LIBS and complementary signals was rather poor due to the large variability of the particle properties of soybean grist material. Still, analyte line normalization on plasma background emission was rather simple and effective for Zn analysis but required a few hundred spot samplings for representative Zn quantification. Non-flat heterogeneous samples (soybean grist pellets) were analyzed by LIBS mapping but it was demonstrated that the choice of sampling area is crucial for reliably analyte determination.

Determination of tantalum in alloy steels by atomic emission spectrometry with inductively coupled plasma

The capabilities of inductively coupled plasma atomic emission spectrometry (ICP-AES) for the determination of tantalum in alloy steels without separation of matrix components have been analyzed. The analytical lines of tantalum and the method of sample preparation are selected. The effect of acids present in the analyzed solution on the analytical signal of Та has been studied. Optimal conditions of measurements were determined by changing one of the operational plasma parameters at simultaneous stabilization of all other parameters. The influence of the components of alloy steels on the analytical signal of tantalum has been studied. The metrological characteristics of the technique were evaluated proceeding from the results of analysis of certified mixtures (CM). To assess the correctness of the results obtained we used certified mixtures and standard addition technique. A method for measuring the mass fraction of tantalum in alloy steel samples by ICP-AES in the content range from 0. 01 % to 0. 05 % has been thus developed.