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Indirect spectrophotometric estimation of lidocaine using crystal violet
No full textA simple, quick and perceptive method was developed to estimate Lidocaine in its pure and pharmaceutical forms spectrally using a spectrometer for ultraviolet visible rays, and the method was summarized: by oxidation of the drug using a mixture of bromate and potassium bromide KBr-KBrO3 with an acidic medium, where the remaining oxidizing agent reacts with the dye Crystal violet (CV) to be a dark blue product It gave peak absorption value at 612 nm, with Beer-lambert law (linear concentration) was between (15) and (100) μg/ml while the molar absorption coefficient was equal to (1945.022) L/mol/cm , limit of detection (0.36) μg/ml, while the quantity limit was (1.08) μg/ml. The method has been effictively applied to the measurement of Lidocaine in both its pure form and its pharmaceutical preparations
Synthesis and enhanced catalytic performance of CdTe/ZnS heterostructured nanocomposites for organic dye reduction
No full textThe successful synthesis and thorough characterization of CdTe/ZnS nanocomposites using the solvothermal method are presented in this work, along with their use as effective and sustainable catalysts for the degradation of organic dyes. UV-Vis spectroscopy is used to analyze the formation of developed materials. The successful engineering of optical properties through nanocomposite formation is demonstrated by the systematic variation in band gap energies from CdTe (1.94 eV) through the composite (2.28 eV) to ZnS (3.63 eV). The formation of sphalerite ZnS and cubic zinc blende CdTe phases with an average crystallite size of about 30 nm was verified by X-ray diffraction analysis. Spherical nanoparticles with sizes between 20 and 80 nm were found using scanning electron microscopy. Congo Red and Rhodamine-B dyes were used to assess the catalytic performance in the presence of NaBH4 using pseudo-first-order kinetics. With rate constants of 0.02923 min⁻¹ for Congo Red and 0.04902 min⁻¹ for Rhodamine-B, the CdTe/ZnS nanocomposite outperformed individual CdTe and ZnS nanoparticles in terms of catalytic activity. The enhanced performance is attributed to synergistic electron-hole separation at the CdTe/ZnS interface. The reusability of the nanocatalytsts revealed that the efficency is withstand for the next three cycles without a noticeable change in morphology. This type of heterostructures represents a promising nanomaterial for environmental remediation applications in efficient organic pollutant removal
Retraction Notice: Recycling Process of Copper Alloys
No full textWe take a zero tolerance to any situation where fraudulent research is published in our journals. As a result, this article has been retracted by the Publisher because it is suspected to be a nonsensical computer-generated publication with a number of tortured phrases and irrelevant references.
Additional measures have been implemented to prevent these issues from reoccurring.
EDP Sciences is extremely grateful to anonymous whistleblowers and the Problematic Paper Screene
A Study on Carbon Asset Management Models under the Global Sustainable Development Context
No full textAgainst the increasingly urgent backdrop of global climate change and sustainable development, carbon emissions have become a key indicator for assessing the greening level of economic activities. As a scarce resource and a market-oriented instrument, carbon emission rights have been incorporated into national governance systems and corporate balance sheets. Based on the theoretical framework of sustainable development, ecological economics, and environmental finance, this paper analyzes the evolution, institutional differences, and practical challenges of global carbon asset management (CAM). It further proposes a carbon asset management model grounded in life cycle assessment (LCA) and dynamic optimization. By integrating four modules—carbon accounting, carbon pricing, carbon investment, and carbon performance evaluation—the model achieves systematic management of carbon assets and supports the realization of global carbon reduction goals
A Comparative Study on the Adsorption Performance and Mechanisms of Different Biochar Materials for Heavy Metal Ions in Water
No full textThe escalating issue of heavy metal contamination in aqueous environments poses a significant threat to ecological balance and human health. Biochar, a carbon-rich material derived from biomass pyrolysis, has emerged as a cost-effective and environmentally benign adsorbent for water remediation. However, the adsorption efficacy of biochar is profoundly dependent on its original feedstock. This study provides a comprehensive comparison of the adsorption performance and underlying mechanisms of three distinct biochars, derived from rice husk (RHB), pine wood (PWB), and chicken manure (CMB)，for the removal of lead (Pb (II)) and cadmium (Cd (II)) from water. The materials were prepared via slow pyrolysis at 500°C and systematically characterized by means of BET, SEM, FTIR, and XRD. Batch adsorption experiments were conducted to evaluate the effects of pH, contact time, and initial ion concentration. The results indicated significant differences in both performance and mechanisms. CMB, rich in minerals and exhibiting a high pH in aqueous solution, exhibited the highest adsorption capacity for Pb (II) (148.5 mg/g) primarily through precipitation and ion exchange. Conversely, RHB, with its high specific surface area (289.4 m²/g) and siliceous structure, showed a superior performance for Cd (II) (89.2 mg/g), which was driven by surface complexation and physical adsorption. PWB demonstrated moderate, non-specific adsorption. Kinetic studies revealed that the pseudo-second-order model best described the adsorption process for all materials, which indicates chemisorption is a key rate-limiting step. The isotherm data of RHB and PWB fitted well with the Langmuir model, while that of CMB was more suitable for the Freundlich model due to its heterogeneous surface. This research underscores the critical importance of feedstock selection in designing biochar adsorbents tailored to remove specific heavy metal pollutants
Program Derivation and Mechanized Verification of Edit Distance Algorithm
No full textEdit distance is an algorithm to measure the difference between two strings, usually represented as the minimum number of editing operations required to transform one string into another. The edit distance algorithm involves complex dependencies and constraints, making state management and verification work tedious. This paper proposes a derivation and verification method that avoids directly handling dependencies and constraints by proving the equivalence between the edit distance algorithm and existing functional modeling. First, the derivation process of edit distance algorithm mainly includes 1) describing problem specifications, 2) inductively deducing recursive relations, 3) formally constructing loop invariants using the optimization theory (memorization technology and optimal decision table) and properties (optimal substructure property and subproblems overlapping property) of the edit distance algorithm, 4) generating the Minimalistic Imperative Programming Language (IMP) code based on the recursive relations. Second, the problem specification, loop invariants, and generated IMP code are input into Verification Condition Generator (VCG), which automatically generate five verification conditions, and then the correctness of edit distance algorithm is verified in the Isabelle/HOL theorem prover. The method utilizes formal technologies and theorem prover to complete the derivation and verification of the edit distance algorithm, and it can be applied to linear and nonlinear dynamic programming problems
The Role of Public Relations in The Transformation of Corporate Communication at Kalla Group
No full textThe digital era has significantly transformed the corporate communication landscape across various sectors, including the adoption of digital public relations. However, previous research predominantly focuses on national or global corporations, leaving limited studies on how digital technology supports corporate communication transformation in local business groups. This study analyzes the role of digital PR in the corporate communication transformation of the Kalla Group. Using a descriptive qualitative approach, the research collected primary data through in-depth interviews, observations, and document analysis. Informants were selected purposively based on their experience in digital PR roles. Data were analyzed using the Miles and Huberman. The findings reveal that digital PR plays a strategic role enhancing corporate reputation and public trust in the digital era. Digital PR is also instrumental in strengthening decision-making processes through media monitoring to identify public sentiment, emerging trends, organizational issues, and media dynamics beyond the scope of Eastern Indonesia. Furthermore, this study highlights the importance of media segmentation to ensure effective communication targeting more specific audiences. Overall, the role of digital PR at Kalla Group reflects the relevance of the Theory of Public Relations Excellence as a conceptual foundation in understanding the evolving function of public relations in digital transformation
Multimodal atmospheric characterization of
No full textContext. Characterizations of giant exoplanets such as β Pictoris b (hereafter β Pic b) are now routinely performed with multiple spectrographs and imagers exploring different spectral bandwidths and resolutions, allowing for atmospheric retrieval of spectra with or without the conservation of the planet spectral continuum. The accounting of data multimodality in the analysis could provide a more comprehensive determination of the planets physical and chemical properties and inform on their formation history.
Aims. We present the first VLTI observations at Rλ ∼4000 of β Pic b obtained for an exoplanet with GRAVITY at such a high resolution. We upgraded the forward modelling code ForMoSA to account for the data multimodality, including low-, medium-, and high-resolution spectroscopy based on both a direct model-data comparison and an analysis of cross-correlation signals. We used the ForMoSA code to refine the constraints on the atmospheric properties of the exoplanet and evaluated the sensitivity of the retrieved values to the input dataset.
Methods. We obtained four high-signal-to-noise (S/N ∼ 20) spectra of β Pic b in the K band with GRAVITY at Rλ ∼4000 conserving both the pseudo-continuum and the pattern of molecular absorptions. We used ForMoSA with four grids of self-consistent forward models (Exo-REM, ATMO, BT-Settl, and Sonora) to explore different Teff, log(g), metallicity, C/O, and 12CO/13CO ratio values. We then combined the GRAVITY spectra with published 1–5 µm photometry (NaCo, VisAO, NICI, and SPHERE), low-to-mediumresolution (Rλ ≤ 700 broadband, 0.9–7 µm) spectra, and echelle spectra covering narrower bandwidths (Rλ ∼ 100 000, 2.1–5.2 µm).
Results. Sonora and Exo-REM are statistically preferred among all four models, regardless of the dataset used. Exo-REM predicts Teff = 1607.45−6.20+4.85 K and log(g) = 4.46−0.04+0.02 dex when using only the GRAVITY epochs, whereas we have Teff = 1502.74−2.14+2.32 K log(g) = 4.00 ± 0.01 dex when incorporating all available datasets. The inclusion of archival data significantly affects all retrieved posteriors. When using all datasets, C/O mostly remains solar (0.552−0.002+0.003), while [M/H] reaches super-solar values (0.50 ± 0.01). We report the first tentative constraint on the isotopic ratio log(12CO/13CO) = 1.12−0.08+0.11 in β Pic b’s atmosphere; however, we note that this detection remains inconclusive due to telluric residuals affecting both the GRAVITY and SINFONI data. Additionally, we estimated the bolometric luminosity as log(L/L⊙) = −4.01−0.05+0.04 dex. Using a system age of 23 ± 3 Myr, along with this bolometric luminosity and the constraints on the dynamical mass of β Pic b, we were able to constrain the maximum of heavy element content of the planet to be on the order of 5% (20–80 MEarth).
Conclusions. The joint access to the pseudo-continuum and molecular lines in the K band provided by GRAVITY have a significant impact on the retrieved metallicity, possibly owing to the collision-induced absorption driving the continuum shape of the K band. The echelle spectra do not dominate the final fit with respect to lower resolution data covering a broader portion of the spectral energy distribution and the latter keeps encapsulating more robust information on Teff. Future multimodal frameworks should include a weighting scheme to account for the bandwidth and central wavelength of the observations
Underwater 3D target detection: Semi-analytic Monte Carlo model and UAV-based scanning lidar system
No full textLidar has been widely applied in marine research due to its strong penetration capability in water. To study the lidar detection of underwater targets, a semi-Monte Carlo model of target detection (MCT) is developed to simulate the scanning signals, incorporating three-dimensional interaction processes between the beam and the target, the wind-driven surface waves and stratified water columns. A UAV-based linear scanning oceanic lidar system (SOL) is developed for model validation. The model is validated by the lidar equation results with a less than 5% mean relative error within the upper 50 m, and further confirmed by the SOL field experiments through consistent target localization. The detection capabilities of SOL are analyzed based on the MCT model for Jerlov II and Jerlov 3C water types, and an extended detection range is introduced to evaluate the variation of horizontal scanning resolution with target depth, providing guidance for balancing detection capability and efficiency under varying conditions