Chemical Balance Research Articles

Biomass fast pyrolysis kinetics using curie-point pyrolysis: Comparison with pyroprobe and thermogravimetric analysis

In this study, the kinetics of fast pyrolysis of pine wood biomass at short timescales is evaluated using analytical Curie-point and Pyroprobe® pyrolyzers. Curie-point pyrolysis was highly effective in ensuring that the biomass was heated to the set temperatures at very high heating rates and precise time scales. This is the first time the mass loss data of lignocellulosic biomass using a Curie-point pyrolyzer is being reported at short timescales of the order of 10−1 s. COMSOL Multiphysics® simulations, employed to determine the time required for the sample to heat-up to the final reaction temperature, proved that it was 0.2 s in the Curie-point pyrolyzer and 6–8 s in the Pyroprobe® reactor. Within a time period of 0.5 s for temperatures greater than 400 °C, complete conversion of the biomass was achieved using a Curie-point pyrolyzer. The conventional reaction kinetic models were not able to explain the pyrolysis behavior of the sample in a Curie-point pyrolyzer, especially at short timescales of 0–0.5 s. However, the kinetics until 0.4 s, corresponding to the release of light volatiles, is shown to follow the sigmoidal Avrami model, while the major devolatilization stage in the range of 0.4–0.5 s could not be described by a standard kinetic model. This showed that the reactions at short time scales are highly complex processes governed by the competing decomposition rates of the biomolecules. The isothermal mass loss experiments using the Pyroprobe® showed that pyrolysis followed first-order kinetics, and the rate of decomposition was slower as it took 10–20 s for the conversion to attain a steady value. The kinetic compensation for the pyrolysis of pinewood was constructed using the fast pyrolysis data and the kinetics of slow pyrolysis using isoconversional models, and it was found to be ln(A) = 0.18*Ea – 3.12.

Generation of a precise time scale assisted by a near-continuously operating optical lattice clock

Generation of a precise time scale assisted by a near-continuously operating optical lattice clock

Production of a guide in Brazilian Sign Language for chemical laboratory utensils

The inclusion of deaf people in the Brazilian educational system is guaranteed by the use of Brazilian Sign Language (Libras). It is important that the learning process of these students, especially when dealing with abstract concepts such as those related to Chemistry, is offered based on teaching tools that cover this language. The objective of this work was to develop a guide with signs in Libras, already existing in the literature, of chemistry laboratory materials as a didactic device aiming to promote inclusion and facilitate access to experimental chemistry teaching for deaf students. The work began with meetings to plan the preparation of the booklet and choose the most common materials in laboratory classes (analytical balance, volumetric flask, beaker, burette, Erlenmeyer flask, funnel, suction bulb, volumetric and graduated pipettes, beaker and glass clock) accompanied by searching for the corresponding sign in Libras. The guide was created considering the five Libras parameters: point of articulation, movement, facial/body expression, configuration and orientation of the hands. Therefore, the material created constitutes a facilitator and important tool for interaction between teacher and student in laboratory classes, resulting in a more dynamic and efficient teaching and learning process for the target audience.

Pengaruh Terapi Emotional Freedom Technique(EFT) Terhadap Pencegahan PostpartumBlues Pada Ibu Pasca Melahirkan di Wilayah Kerja Puskesmas Cahya Maju Kecamatan Lempuing

The lack of knowledge about postpartum blues among postpartum mothers in the Puskesmas Cahya Maju. This lack of awareness leads to many mothers not recognizing the symptoms of postpartum blues and potentially worsening their condition. The research problem is the need for prevention methods for postpartum blues in postpartum mothers. The aim of the study is to investigate the effectiveness of the Emotional Freedom Technique (EFT) as a self-administered therapy for postpartum blues. The methodology used in this study is the EFT therapy, which utilizes the body's meridian points to address energy imbalances that contribute to psychological effects. EFT is a branch of energy psychology that aims to improve mental, emotional, and behavioral conditions by addressing imbalances in the body's energy system. The participants in this study are postpartum mothers who are experiencing symptoms of postpartum blues. The therapy is self-administered by the mothers at home without the assistance of a therapist. The results of the study show that EFT therapy is effective in reducing symptoms of postpartum blues in postpartum mothers. The therapy helps restore balance to the body's energy system, which in turn improves the chemical balance in the brain and emotional state. This finding has important implications for the prevention and management of postpartum blues in postpartum mothers.The study highlights the importance of raising awareness about postpartum blues and providing prevention methods for postpartum mothers. The use of EFT therapy as a self-administered treatment option offers a convenient and effective approach for postpartum mothers to manage their symptoms.

From Bin to Binder: Unleashing Waste Butter’s Potential as a Pioneering Bio-Modifier for Sustainable Asphalt Engineering

Exploring the interface of environmental sustainability and civil infrastructure development, this study introduces waste butter (WB), a byproduct of animal fat processing, as a novel bio-modifier in asphalt production. This approach not only recycles animal waste but also charts a course for sustainable infrastructural development, contributing to a reduced environmental impact and promoting circular economy practices. The experiments incorporated varying WB concentrations (e.g., 3%, 6%, and 9% by weight of binder) into standard AP-5 asphalt, employing advanced analytical tools for comprehensive characterization. These included thin-layer chromatography–flame ionization detection (TLC-FID), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Differential Scanning Calorimetry (DSC). The critical properties of the asphalt blends, such as penetration, softening point, viscosity, ductility, rutting factor (Dynamic Shear Rheometer), and thermal susceptibility (Penetration Index, Penetration–Viscosity Number), were assessed. FT-IR analysis indicated negligible chemical alteration with WB addition, suggesting predominantly physical interactions. TLC-FID showed a decrease in aromatic and asphaltene components but an increase in resin content, highlighting the influence of WB’s fatty acids on the asphalt’s chemical balance. The colloidal instability index (IC) confirmed enhanced stability due to WB’s high resin concentration. Meanwhile, SEM analysis revealed microstructural improvements with WB, enhancing binder compatibility. TGA demonstrated that even a minimal 3 wt. % WB addition significantly improved thermal stability, while the DSC results pointed to improved low-temperature performance, reducing brittleness in cold conditions. Rheologically, WB incorporation resulted in increased penetration and ductility, balanced by decreased viscosity and softening point, thereby demonstrating its multi-faceted utility. Thermal susceptibility tests emphasized WB’s effectiveness in cold environments, with further evaluation needed at higher temperatures. The DSR findings necessitate careful WB calibration to meet Superpave rutting standards. In conclusion, this research positions waste butter as a superior, environmentally aligned bio-additive for asphalt blends, contributing significantly to eco-friendly civil engineering practices by repurposing animal-derived waste.

Utilizing large language models for EFL essay grading: An examination of reliability and validity in rubric‐based assessments

AbstractThis study investigates the validity and reliability of generative large language models (LLMs), specifically ChatGPT and Google's Bard, in grading student essays in higher education based on an analytical grading rubric. A total of 15 experienced English as a foreign language (EFL) instructors and two LLMs were asked to evaluate three student essays of varying quality. The grading scale comprised five domains: grammar, content, organization, style & expression and mechanics. The results revealed that fine‐tuned ChatGPT model demonstrated a very high level of reliability with an intraclass correlation (ICC) score of 0.972, Default ChatGPT model exhibited an ICC score of 0.947 and Bard showed a substantial level of reliability with an ICC score of 0.919. Additionally, a significant overlap was observed in certain domains when comparing the grades assigned by LLMs and human raters. In conclusion, the findings suggest that while LLMs demonstrated a notable consistency and potential for grading competency, further fine‐tuning and adjustment are needed for a more nuanced understanding of non‐objective essay criteria. The study not only offers insights into the potential use of LLMs in grading student essays but also highlights the need for continued development and research. Practitioner notesWhat is already known about this topic Large language models (LLMs), such as OpenAI's ChatGPT and Google's Bard, are known for their ability to generate text that mimics human‐like conversation and writing. LLMs can perform various tasks, including essay grading. Intraclass correlation (ICC) is a statistical measure used to assess the reliability of ratings given by different raters (in this case, EFL instructors and LLMs). What this paper adds The study makes a unique contribution by directly comparing the grading performance of expert EFL instructors with two LLMs—ChatGPT and Bard—using an analytical grading scale. It provides robust empirical evidence showing high reliability of LLMs in grading essays, supported by high ICC scores. It specifically highlights that the overall efficacy of LLMs extends to certain domains of essay grading. Implications for practice and/or policyThe findings open up potential new avenues for utilizing LLMs in academic settings, particularly for grading student essays, thereby possibly alleviating workload of educators.The paper's insistence on the need for further fine‐tuning of LLMs underlines the continual interplay between technological advancement and its practical applications.The results lay down a footprint for future research in advancing the use of AI in essay grading.

Chemical recycling of complex reject streams from the paper industry via thermal and catalytic pyrolysis

Paper-based packaging is a complex multi-material composed of paper (fibers), plastics, and metals, making efficient material recycling complicated. Currently, most of the fibers are recycled into new paper products while the residual material is commonly incinerated. Therefore, to improve the circularity and reduce the fossil dependency chemical recycling is needed. In this study, recycling of the residual materials was evaluated by thermal and catalytic pyrolysis. First, screening tests were performed using five reject materials and four catalysts in an analytical scale and then, a selection of catalyst and reject materials were evaluated in lab-scale followed by a techno-economic assessment. Experimental results indicated that the conversion was more efficient if the reject had high content of plastics compared to fibers, leading to products with increased heating value, higher hydrocarbon yield and less reactive oxygenates compared to the rejects with low plastic ratio. In the thermal pyrolysis 54 % of the weight of the feedstock and 70 wt% of the carbon in the feedstock ended up in a solid organic product (wax) which contained hydrocarbons and alcohols. In the analytical catalytic pyrolysis, HZSM-5 gave the best result in terms of cracking, deoxygenation, and aromatization. Ex-situ catalytic pyrolysis using HZSM-5 resulted in an improved quality of organic liquid with reduced hydrocarbon length as well as deoxygenated and aromatic compounds. The yield of the organic liquid was up to 19 wt% and contained mainly monoaromatics. The techno-economic evaluation showed, for processing 100,000 tons year−1 residual material, the total plant investment and the annual profit are about 29 and 12 million Euros, respectively, if no incentive for treating the residual material.

Tuber production of Tropaeolum pentaphyllum Lam. from different sizes of seed-tubers in two cultivation cycles

The liana Tropaeolum pentaphyllum Lam. is an unconventional food plant with potential economic exploitation. This study aimed to evaluate the vegetative propagation of T. pentaphyllum using seed-tubers. A total of 140 tubers were classified into four mass classes: I) < 10 g, II) 10 to 30 g, III) 30 to 70 g, and IV) > 70 g. Each mass class contained 35 tubers. The experiment was carried out in a greenhouse at Federal Institute of Rio Grande do Sul, Sertão, southern Brazil, with temperature and relative humidity of 25°C and 50%, respectively. When the senescence of the aerial stem system occurred, the mass of the tubers was measured using a precision scale (0.01 grams). Analysis of variance and Tukey’s test (p < 0.05) were used to analyze the data obtained in the experiment. In addition, descriptive statistics (mean ± standard deviation) were also used. The ratio between the initial and final masses per tuber class was calculated and the production averages between tuber classes were compared. The annual and biennial productions show that the classes of tuber seeds with mass above 10 g (II, III, and IV) produce more tubers. Class II and III are indicated for annual cultivation considering both the production in number and mass. Regarding the production of tubers for sale, class I with biennial planting is indicated since it presents a more significant mass increment.

Development and implementation of a Python functions for automated chemical reaction balancing

<p>Chemical reaction balancing is a fundamental aspect of chemistry, ensuring the conservation of mass and atoms in reactions. This article introduces a specialized Python functions designed for automating the balancing of chemical reactions. Leveraging the versatility and simplicity of Python, the module employs advanced algorithms to provide an efficient and user-friendly solution for scientists, educators, and industry professionals. This article delves into the design, implementation, features, applications, and future developments of the Python functions for automated chemical reaction balancing. The functions thus developed were tested on some typical chemical reactions and the results are the same as that in the literature.</p>

D-optimal chemical balance weighing designs with positively correlated errors: part III

Summary In this paper we consider issues related to the determination of chemical balance weighing designs satisfying the criterion of D-optimality. This problem is considered under the assumption that the measurements are equally positively correlated and they have the same variances. We answer the question of how to add four runs to a regular D-optimal chemical balance weighing design in order to obtain a highly D-efficient design. The problem formulated in this way leads to an extension of results contained in a previous paper in Biometrical Letters.

Quality by design−aided acid-free synthesis of self P, N, S-doped black seed-derived carbon quantum dots for application as a nanosensor for eltrombopag environmental and bioanalysis and pharmacokinetic assay

Herein, we developed a rapid, one-step, and cost-effective methodology based on the fabrication of water-soluble self-nitrogen, sulfur, and phosphorus co-doped black seed carbon quantum dots (BSQDs) via microwaveirradiation in six minutes. Our synthesis approach is superior to those in the literature as they involved long-time heating (12 h) with sulfuric acid and sodium hydroxide and/or high temperatures (200 °C). A full factorial design was applied to obtain the most efficient synthesis conditions.BSQDs displayed excitation-independent emissions, demonstrating the purity of the synthesized BSQDs, with a maximum fluorescence at 425 nm after excitation at 310 nm. Eltrombopag olamine is an anti-thrombocytopenia drug that is also reported to cause toxicity in river water based on its Persistence, Bioaccumulation, and Toxicity (PBT). The synthesized BSQDs were employed as the first fluorometric sensor for environmental and bioanalysis of eltrombopag. The fluorescence of BSQDs decreased with increasing concentrations of eltrombopag, with excellent selectivity and sensitivity down to 30 ppb. BSQDs were successfully applied as sensing probes for the detection of eltrombopag in medical tablets, spiked and real human plasma samples, and river water samples, with an overall recovery of at least 97 %. The good tolerance to high levels of foreign components and co-administered drugs indicates good selectivity and versatility of the proposed methodology. Plasma pharmacokinetic parameters such as t1/2, Cmax, and t max of eltrombopag were evaluated to be 9.91 h, 16.0 μg mL−1, and 5 h, respectively. Moreover, the green character of the BSQDs as a sensor was proved by various analytical greenness scales.

Enhancing the bioactivity of Dunaliella salina extracts through ultra-high pressure supercritical fluid extraction (UHP-SFE)

Dunaliella salina is a green microalga known for its high carotene content, especially in β-carotene isomers, which are very interesting compounds due to their biological activity. The neuroprotective effect of β-carotene has been related to the potential prevention of multifactorial neurological pathologies. The use of green extraction processes for the extraction of carotenoids present in D. salina has generated a great advance in the production of carotenoid-enriched extracts. In this work, supercritical fluid extraction at ultra-high pressure (UHP-SFE) at semi-pilot scale has been evaluated for the first time for the extraction of β-carotene isomers from D. salina. The effect of the pressure was determined by an experimental design, and results showed that both the carotenoid extraction and the neuroprotective activity of the obtained extracts were maximum at 84.9 MPa. At this ultra-high pressure, the extraction yield was improved 1.35 times, the total terpene and carotene content increased 2.02 and 1.61 times, respectively, and the neuroprotective activity was 2.44 and 1.60 (for acetylcholinesterase and butyrylcholinesterase inhibition capacity, respectively) higher in comparison to the CP-SFE extract. Therefore, UHP-SFE is presented as a more selective extraction process with a higher potential to generate enriched extracts with increased bioactivity than SFE procedures under moderate pressure conditions. Moreover, it has been demonstrated that the use of the semi-pilot UHP-SFE process had a greener potential for the recovery of bioactive carotenoid-enriched extracts than the analytical scale process. Industrial relevanceThe industrial scaling-up of extraction processes is a current need. In this sense, in this work, the semi-pilot SFE process has been shown as a more automatic and safer process than the analytical scale. Additionally, the use of UHP in the SFE semi-pilot scale has allowed reducing the extraction time to half of the initial time obtaining higher extraction yields. The UHP-SFE extract provides enriched carotene products with increased neuroprotective activity with greater industrial performance. Therefore, this work becomes the starting point for achieving a high throughput β-carotene extract process at industrial scale.

Colossal Ferroelectric Photovoltaic Effect in Inequivalent Double-Perovskite Bi2FeMnO6 Thin Films.

Double perovskite films have been extensively studied for ferroelectric order, ferromagnetic order, and photovoltaic effects. The customized ion combinations and ordered ionic arrangements provide unique opportunities for bandgap engineering. Here, a synergistic strategy to induce chemical strain and charge compensation through inequivalent element substitution is proposed. A-site substitution of the barium ion is used to modify the chemical valence and defect density of the two B-site elements in Bi2FeMnO6 double perovskite epitaxial thin films. We dramatically increased the ferroelectric photovoltaic effect to ∼135.67 μA/cm2 from 30.62 μA/cm2, which is the highest in ferroelectric thin films with a thickness of less than 100 nm under white-light LED irradiation. More importantly, the ferroelectric polarization can effectively improve the photovoltaic efficiency of more than 5 times. High-resolution HAADF-STEM, synchrotron-based X-ray diffraction and absorption spectroscopy, and DFT calculations collectively demonstrate that inequivalent ion plays a dual role of chemical strain (+1.92 and -1.04 GPa) and charge balance, thereby introducing lattice distortion effects. The reduction of the oxygen vacancy density and the competing Jahn-Teller distortion of the oxygen octahedron are the main phenomena of the change in electron-orbital hybridization, which also leads to enhanced ferroelectric polarization values and optical absorption. The inequivalent strategy can be extended to other double perovskite systems and applied to other functional materials, such as photocatalysis for efficient defect control.

Introducing two improved methods for approximating radiative cooling in hydrodynamical simulations of accretion discs

ABSTRACT The evolution of many astrophysical systems depends strongly on the balance between heating and cooling, in particular star formation in giant molecular clouds and the evolution of young protostellar systems. Protostellar discs are susceptible to the gravitational instability, which can play a key role in their evolution and in planet formation. The strength of the instability depends on the rate at which the system loses thermal energy. To study the evolution of these systems, we require radiative cooling approximations because full radiative transfer is generally too expensive to be coupled to hydrodynamical models. Here, we present two new approximate methods for computing radiative cooling that make use of the polytropic cooling approximation. This approach invokes the assumption that each parcel of gas is located within a spherical pseudo-cloud, which can then be used to approximate the optical depth. The first method combines the methods introduced by Stamatellos et al. and Lombardi et al. to overcome the limitations of each method at low and high optical depths, respectively. The second method, the ‘modified Lombardi’ method, is specifically tailored for self-gravitating discs. This modifies the scale height estimate from the method of Lombardi et al. using the analytical scale height for a self-gravitating disc. We show that the modified Lombardi method provides an excellent approximation for the column density in a fragmenting disc, a regime in which the existing methods fail to recover the clumps and spiral structures. We therefore recommend this improved radiative cooling method for more realistic simulations of self-gravitating discs.

Approaching Maximal Precision of Hong-Ou-Mandel Interferometry with Nonperfect Visibility.

In quantum mechanics, the precision achieved in parameter estimation using a quantum state as a probe is determined by the measurement strategy employed. The quantum limit of precision is bounded by a value set by the state and its dynamics. Theoretical results have revealed that in interference measurements with two possible outcomes, this limit can be reached under ideal conditions of perfect visibility and zero losses. However, in practice, these conditions cannot be achieved, so precision never reaches the quantum limit. But how do experimental setups approach precision limits under realistic circumstances? In this Letter, we provide a model for precision limits in two-photon Hong-Ou-Mandel interferometry using coincidence statistics for nonperfect visibility and temporally unresolved measurements. We show that the scaling of precision with visibility depends on the effective area in time-frequency phase space occupied by the state used as a probe, and we find that an optimal scaling exists. We demonstrate our results experimentally for different states in a setup where the visibility can be controlled and reaches up to 99.5%. In the optimal scenario, a ratio of 0.97 is observed between the experimental precision and the quantum limit, establishing a new benchmark in the field.

Advanced high-resolution chromatographic strategies for efficient isolation of natural products from complex biological matrices: from metabolite profiling to pure chemical entities

AbstractThe isolation of pure compounds from extracts represents a key step common to all investigations of natural product (NP) research. Isolation methods have gone through a remarkable evolution. Current approaches combine powerful metabolite profiling methods for compounds annotation with omics mining results and/or bioassay for bioactive NPs/biomarkers priorisation. Targeted isolation of prioritized NPs is performed using high-resolution chromatographic methods that closely match those used for analytical profiling. Considerable progress has been made by the introduction of innovative stationary phases providing remarkable selectivity for efficient NPs isolation. Today, efficient separation conditions determined at the analytical scale using high- or ultra-high-performance liquid chromatography can be optimized via HPLC modelling software and efficiently transferred to the semi-preparative scale by chromatographic calculation. This ensures similar selectivity at both the analytical and preparative scales and provides a precise separation prediction. High-resolution conditions at the preparative scale can notably be granted using optimized sample preparation and dry load sample introduction. Monitoring by ultraviolet, mass spectrometry, and or universal systems such as evaporative light scattering detectors and nuclear magnetic resonance allows to precisely guide the isolation or trigger the collection of specific NPs with different structural scaffolds. Such approaches can be applied at different scales depending on the amounts of NPs to be isolated. This review will showcase recent research to highlight both the potential and constraints of using these cutting-edge technologies for the isolation of plant and microorganism metabolites. Several strategies involving their application will be examined and critically discussed. Graphical abstract

Rapid synergistic cloud point extraction based on hydrophobic deep eutectic solvent combined with hydride generation atomic absorption spectrometry for determination of selenium in tea samples

Herein, hydrophobic deep eutectic solvents (HDESs) were created for the fast preconcentration of Se(IV) from tea samples at room temperature. A facile and rapid synergistic cloud point extraction (HDES-RS-CPE) procedure was used, followed by hydride generation atomic absorption spectrometry (HG-AAS). The selected synergistic DES included glycine and lauric acid (molar ratio 3:1). 2-hydroxy-5-p-tolylazobenzaldehyde (HTAB) and Triton X-114 were utilized as chelating reagent and non-ionic surfactant, respectively. The experimental parameters that impact extraction recovery were examined and optimized. The detection limit, quantification limit, preconcentration factor, and enhancement factor for Se(IV) under optimum circumstances were 0.02 μg L−1, 0.06 μg L−1, 125, and 149, respectively. The method exhibited analytical linearity in the range up to 700.0 μg L−1. The procedure was used effectively for the quantification of Se(IV) in tea and certified samples. Moreover, the National Environmental Method Index (NEMI), the analytical greenness scale for sample preparation (AGREEprep), and the Green Analytical Procedure Index (GAPI) criteria have been used to measure the greenness score of the extraction procedure. To further highlight the environmental friendliness of this method, a detailed evaluation has been performed.

Analysis of the sustainability of swimming pools: Water and energy cycles

The objective of this article is to conduct a literature review aimed at analyzing recent research conducted between 2018 and March 2023 concerning the water and energy cycles in swimming pools. This review aims to provide updated information by considering the impact of the COVID-19 pandemic on the sector. Additionally, it serves as a complementary review to a previous study that encompassed research up until 2018. Four challenges that the review seeks to analyze and investigate are identified: water balance, energy balance, chemical balance, water treatment, and diverse legislation. Regarding the water balance, the importance of reducing evaporation from swimming pools is highlighted, especially in Mediterranean climates with prolonged drought periods. Various solutions to improve the water balance are analyzed, such as the use of solar covers and the optimization of the water recirculation and filtration system. In relation to the energy balance, it is recognized that the use of pumps and filters consumes a lot of energy. The review emphasizes the importance of optimizing the water recirculation and filtration system, and various ways to improve the energy efficiency of pool heating and air conditioning are examined. In addition, the use of renewable energy technologies, such as solar panels, to reduce the energy demand of pools is considered. In summary, this review updates previous research on the water and energy cycles in swimming pools, with a focus on water and energy balance. The review identifies challenges and solutions to improve the sustainability of pools and highlights the importance of addressing the complexity of applicable legislation. The results of this review are expected to be useful for future research and to promote more sustainable management of swimming pools.

Electroelastic wave dispersion in the rotary piezoelectric NEMS sensors/actuators via nonlocal strain gradient theory

This article introduces a computational means for investigating the electroelastic nonlinear wave dispersion traits of the nano-dimension sandwich pipe, which is composed of a core formed of a bi-directional functionally graded (Bi-FG) material, together with a piezoelectric sensor/actuator. A combination of Hamilton’s principle, first-order shear deformation, along with Von-Karman nonlinearity, is used for modeling and obtaining the nonlinear governing equations of the nano-sized sandwich pipe connected to a piezoelectric part. The nonlinear governing equations to obtain the nonlinear phase velocity of the current system are determined using a combination of analytical and multiple scales approaches. Due to some computational cost for choosing the precise values of both the nonlocality factor and length scale of the nanopipe in the laboratory, for the first time in this research, with the aid of COMSOL multi-physics finite element simulation, the results are verified, and new outcomes for obtaining the exact functions for nonlocal and length scale factors is presented. In addition, an artificial neural network (ANN) is utilized in this study for the prediction of the results. The mathematical and finite element results were used to train the ANN. A newly presented optimization algorithm is exploited for the first time for optimizing the ANN parameters concluding higher accuracy of the ANN predictions. Consequently, to explore the influences of the location of the piezoelectric patch, nonlocality and length scale factors, and applied voltage parameter on the phase velocity characteristics of the nano-dimension sandwich pipe made of a Bi-FG core and electrically patch, an effort is performed. As an applicable result that can be useful in the related nano-industries, the current work presents exact nonlocal and length scale functions for different conditions.

Two masterful alternative spectrophotometric methods for the determination of ramipril in tablets

The aim of the work was to develop two simple, rapid, economic, alternative spectrophotometric methods for the determination of ramipril in tablets based on the reaction with sulfonephthalein dyes (bromphenol blue (BPB) and cresol red (CR)). Materials and methods. Analytical instrumentation: Shimadzu UV-1800 double beam UV-VIS spectrophotometer (Japan) with attached UV-Probe ver. 2.62 software, RAD WAG AS 200/C precise analytical balance (Poland). Ramipril (purity ≥98 % (HPLC)) was purchased from AARTI Industries Limited (India). Ramipril tablets 5 mg and 10 mg were purchased from a local pharmacy. Results and discussion. Two spectrophotometric methods for the determination of ramipril in tablets have been developed. We have tested various sulfophthalein dyes (BPB, bromocresol green, bromthymol blue, thymol blue, CR) in order to choose the optimal for the method development. According to the results of the experimental studies, we chose BPB and CR as reagents, and the solvent was acetonitrile for both methods. The optimal conditions for the quantitative determination of ramipril in tabletsy using BPB were established: dye concentration - 2.35×10-4 mol/L, volume of BPB solution – 1.0 ml, without heating, wavelength – 598 nm, reaction time – 5 min, temperature of the solution – 25 °C. The optimal conditions for the quantitative determination of ramipril in tabletsusing CR were established: dye 1.33×10-4 mol/L, volume of CR solution – 1.0 ml, without heating, wavelength – 395 nm, reaction time – 5 min, temperature of the solution – 25 °C. The spectrophotometric method by using BPB was linear in the concentration range of 1.99-5.96 µg/mL, LOD – 0.20 µg/mL, LOQ – 0.60 µg/mL. The spectrophotometric method using CR was linear in the concentration range of 0.42-5.44 µg/mL, LOD – 0.10 µg/mL, and LOQ – 0.36 µg/mL. The results of the study on robustness, accuracy, and precision were within the acceptance criteria. The results of studying the «greenness» of both methods indicate an excellent «green» analysis.Conclusions. Developed methods can be used as an alternative method for the routine analysis of ramipril tablets