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Records Added in July 2023
Records added in July 2023
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101. LAPSE:2023.36306
Research on and Design of an Electric Drive Automatic Control System for Mine Belt Conveyors
July 7, 2023 (v1)
Subject: Process Design
Keywords: automatic control systems, conveyor belt, electric drive, transmission technology
Conveyor belts are widely used in ore transportation in large-scale mines for their long transportation range, high safety, and strong economic applicability. Coal mine belt conveyors are not only traditional, simple mechanical conveying devices but also automatic control system operating devices that integrate safety, stability, and low power consumption. In the process of coal mining, a conveyor belt control system also needs to be closely integrated with modern industrial systems and information systems, which greatly improves its work efficiency. The purpose of this article is to improve the methods for designing automatic control systems for electric motors in order to obtain mechanical characteristics close to a constant power line, which would ensure the reliable operation of belt conveyors. An automatic control system was designed based on the controller Siemens S7-1200; then, a mathematical model of an automated electric drive was developed. Based on the mathematical model, a... [more]
102. LAPSE:2023.36305
Impact of the New Energy Context on the Feasibility of Solar Water Heating Systems in the Agri-Food Industry
July 7, 2023 (v1)
Subject: Food & Agricultural Processes
Keywords: agri-food industry, energy saving, evacuated tube collector, profitability, solar water-heating system
The new energy context since 2021 has led to dramatic increases in the energy bills of agribusinesses, affecting the price of foodstuffs. A considerable part of energy consumption is due to the heating of water at high temperatures. The present study analyzed the feasibility of using a Solar Water Heating System (SWHS) with an evacuated tube collector. In particular, the required sizing changes, potential savings and cost-effectiveness were analyzed. The results show that the new energy context makes the SWHS investment highly attractive: a payback of less than 4 years in most of the scenarios analyzed; energy savings of more than 60% in the scenarios with higher irradiation; a reduction in total energy expenditure of more than 50% in the favorable scenarios close to the current reality. The new context especially favors cold and temperate climates, with very sharp drops in payback compared to the previous situation. To achieve these values, it is necessary to design an optimized sizin... [more]
103. LAPSE:2023.36304
Customized Cost-Effective Cranioplasty for Large Asymmetrical Defects
July 7, 2023 (v1)
Subject: Process Design
Keywords: additive manufacturing, anatomical design, cranioplasty, customized implants, fitting accuracy analysis
Cranioplasty or cranial reconstruction is always a challenging procedure even for experienced surgeons. In this study, two different design techniques for customized cranial prostheses are assessed for cranial reconstruction. Mirror reconstruction is one of the commonly used reconstruction techniques that fails when cranial defects cross the midline of symmetry. Hence, there is a need for a design technique for the reconstruction of cranial defects irrespective of their location on the symmetrical plane. The anatomical reconstruction technique demonstrates its applicability for a wide spectrum of complex skull defects irrespective of the defective position in the anatomical structure. The paper outlines a methodological procedure involving a multi-disciplinary approach involving physicians and engineers in the design and reconstruction of customized cranial implants for asymmetrical skull defects. The proposed methodology is based on five foundation pillars including the multi-discipli... [more]
104. LAPSE:2023.36303
Automatic Optimization of Multi-Well Multi-Stage Fracturing Treatments Combining Geomechanical Simulation, Reservoir Simulation and Intelligent Algorithm
July 7, 2023 (v1)
Subject: Energy Systems
Keywords: automatic optimization, fracture propagation, hydraulic fracturing, reservoir simulation
Shale reserves have become an ever-increasing component of the world’s energy map. The optimal design of multi-well multi-stage fracturing (MMF) treatments is essential to the economic development of such resources. However, optimizing MMF treatments is a complex process. It requires geomechanical simulation, reservoir simulation, and automatic optimization. In this work, an integrated workflow is proposed to optimize MMF treatments in an unconventional reservoir, and the net present value (NPV) of reserves was treated as the objective function. The forward model consists of two submodels: a hydraulic fracturing model and a reservoir simulation model. The stochastic simplex approximation gradient (StoSAG) is used with the steepest ascent algorithm to maximize the NPV function. The computational results show that optimizing the fracture design can achieve a 20% higher NPV than that obtained with the field reference case. The drainage area of the optimal design is larger than that of the... [more]
105. LAPSE:2023.36302
Simulation of Rock Electrical Properties in Deep Reservoirs Based on Digital Rock Technology
July 7, 2023 (v1)
Subject: Other
Keywords: deep reservoirs, digital rock physics, high pressure and high temperature, rock electrical properties
Deep reservoirs are in a high-pressure and high-temperature (HPHT) environment, while the experimental conditions for rock electrical properties that meet the deep reservoir conditions are harsh and costly. Although digital rock technology can simulate the electrical properties of rocks, it is limited to electrical simulation studies under normal temperature and pressure conditions (NPT), which limits their ability to capture the electrical characteristics of deep hydrocarbon reservoirs. This limitation affects the accuracy of saturation prediction based on resistivity logging. To simulate the rock electrical properties under HPHT conditions, we proposed a low-cost and high-efficiency HPHT digital rock electrical simulation workflow. Firstly, samples from deep formations were CT-scanned and used to construct multi-component digital rocks that reflect the real microstructure of the samples. Then, mathematical morphology was used to simulate the overburden correction under high-pressure... [more]
106. LAPSE:2023.36301
Separation of Rare Earth Elements in Multistage Extraction Columns in Chromatography Mode: Experimental Study and Mathematical Simulation
July 7, 2023 (v1)
Subject: Materials
Keywords: closed-loop recycling chromatography, liquid–liquid chromatography, multistage extraction columns, separation of rare earth elements, solvent extraction
The application of liquid−liquid chromatography principles to solvent extraction processes in hydrometallurgy can greatly simplify rare earth metal separation technologies by separating multicomponent mixtures in one technological operation. In this study, the chromatographic separation of rare earth elements (REEs) in multistage extraction columns was experimentally studied under conditions of impulse sample injection—single and multiple loading of large volumes of metal salt solution into the installation. The results obtained showed the feasibility of operating sieve plate extraction columns in the liquid−liquid chromatography mode. A closed-loop recycling technology is proposed for the separation of rare earth elements in multistage extraction columns operating in the liquid−liquid chromatography mode. For further development and industrial implementation of this technology, experimental studies should be conducted on intensified multistage extraction columns, such as sectioned col... [more]
107. LAPSE:2023.36300
The Modification of WO3 for Lithium Batteries with Nickel-Rich Ternary Cathode Materials
July 7, 2023 (v1)
Subject: Materials
Keywords: lithium battery, modification, nickel rich ternary cathode materials, preparation, tungsten trioxide
Nickel-rich ternary cathode materials (NRTCMs) have high energy density and a long cycle life, making them one of the cathode materials of LIB that are currently receiving much attention. However, it has shortcomings such as poor cycling performance (CP) and a high-capacity decay rate. Because of this, the study analyzed the modification effect of WO3 on NRTCM lithium batteries by preparing WO3-modified poly-crystal and single-crystal NCM622 materials under the existing conditions of better original cathode materials as reference samples. The results showed that in the morphology and structure testing, with the increase of WO3 addition, the c/a values of all NCM622-WO3 samples were greater than 4.95. In the analysis of cycling and rate performance (CRP), as W increased, the rate performance (RP) of the NCM622-W4.0 sample had a discharge specific capacity ratio of 86.2% at 10.0 C/1.0 C. In cyclic voltammetry testing, when the addition amount of WO3 was 1.0%, the polarization degree of S... [more]
108. LAPSE:2023.36299
Research on the Mesoscopic Characteristics of Kelvin−Helmholtz Instability in Polymer Fluids with Dissipative Particle Dynamics
July 7, 2023 (v1)
Subject: Food & Agricultural Processes
Keywords: dissipative particle dynamics, Kelvin–Helmholtz instability, mesoscopic fluids, polymer fluids
In this paper, the two-dimensional Kelvin−Helmholtz (KH) instability occurring in the shear flow of polymer fluids is modeled by the dissipative particle dynamics (DPD) method at the coarse-grained molecular level. A revised FENE model is proposed to properly describe the polymer chains. In this revised model, the elastic repulsion and tension are both considered between the adjacent beads, the bond length of which is set as one segment’s equilibrium length. The entanglements between polymer chains are described with a bead repulsive potential. The characteristics of such a KH instability in polymer fluid shear flow can be successfully captured in the simulations by the use of the modified FENE model. The numerical results show that the waves and vortexes grow more slowly in the shear flow of the polymer fluids than in the Newtonian fluid case, these vortexes become flat, and the polymer impedes the mixing of fluids and inhibits the generation of turbulence. The effects of the polymer... [more]
109. LAPSE:2023.36298
Antimicrobial Potential of Tara Hydroalcoholic Extract (Caesalpinia spinosa) against Streptococcus Associated with Strep Throat
July 7, 2023 (v1)
Subject: Biosystems
Keywords: Caesalpinia spinosa, erythromycin, strep throat, β-hemolytic streptococci
Antibiotics are often prescribed to treat infections caused by group B Streptococcus; however, inappropriate use of antibiotics can develop resistance. Because of this, the research was carried out with the aim of evaluating the in vitro effect of the hydroalcoholic extract of Caesalpinia spinosa (Molina) Kuntze known as Taya or Tara on the viability of β-hemolytic streptococci; an experimental investigation of increasing stimulation was carried out. The hydroalcoholic extract of C. spinosa pods was worked in concentrations of 250, 500, 750, and 1000 mg/mL, which were placed on filter paper discs to perform the sensitivity test following the Kirby−Bauer method. The greatest inhibition of bacterial viability was observed in the penicillin control group (GPT-01) followed by the TCT-04 group (hydroalcoholic Tara extract 1000 mg/mL). In addition, it was found that these groups are statistically different from the rest (p < 0.05), while the lowest bacterial inhibition was obtained for th... [more]
110. LAPSE:2023.36297
A Novel Hybrid Approach for Modeling and Optimisation of Phosphoric Acid Production through the Integration of AspenTech, SciLab Unit Operation, Artificial Neural Networks and Genetic Algorithm
July 7, 2023 (v1)
Subject: Numerical Methods and Statistics
Keywords: artificial neural network, Aspen, Genetic Algorithm, multi-objective optimization, phosphoric acid, UCEGO filter
The purpose of the study was to identify and predict the optimized parameters for phosphoric acid production. This involved modeling the crystal reactor, UCEGO filter (as a detailed model of the filter is not available in Aspen Plus or other simulation software), and acid separator using Sci-Lab to develop Cape-Open models. The simulation was conducted using Aspen Plus and involved analyzing 10 different phosphates with varying qualities and fractions of P2O5 and other minerals. After a successful simulation, a sensitivity analysis was conducted by varying parameters such as capacity, filter speed, vacuum, particle size, water temperature for washing the filtration cake, flow of recycled acid and strong acid from the separator below the filter, flow of slurry to reactor 1, temperature in reactors, and flow of H2SO4, resulting in nearly one million combinations. To create an algorithm for predicting process parameters and the maximal extent of recovering H3PO4 from slurry, ANN models we... [more]
111. LAPSE:2023.36296
An Investigation on Optimized Performance of Voluteless Centrifugal Fans by a Class and Shape Transformation Function
July 7, 2023 (v1)
Subject: Optimization
Keywords: centrifugal fan, class-shape-transformation function, dissipation function, Kriging model, Optimization
Class and shape transformation functions are proposed to carry out the parametric design of the blade profiles because fan efficiency is closely related to the shape of blade profiles. An optimization with the objectives of fan efficiency and static pressure based on the Kriging models was established, and numerical simulation data were applied to construct the Kriging models. The dissipation function was used to analyze the fan energy loss. The prediction results show that the maximum accuracy error between the Kriging model and the experimental data is approximately 0.81%. Compared with the prototype fan, the optimized fan was able to ameliorate the distribution of the flow field pressure and velocity; the outlet static pressure increased by 9.03%, and the efficiency increased by 2.35%. The dissipation function is advantageous because it can intuitively indicate the location and amount of energy loss in the fan, while effectively obtaining the total energy loss as well. The situation... [more]
112. LAPSE:2023.36295
Research on Electromagnetic Adsorption Technology Based on Composite Shaft Lining Structure
July 7, 2023 (v1)
Subject: Energy Systems
Keywords: coal mine shaft, composite shaft lining, effective mapping point, electromagnetic adsorption, equivalent adsorption area, fitness function, safety monitoring
The working conditions and environment of coal mine shafts are intricate and special. Currently, manual inspections or fixed-point monitoring is generally applied for daily safety monitoring, and intelligent and automated inspection equipment and its supporting technologies are not available. Starting from the technical requirements of the electromagnetic adsorption device of the wall-climbing robot for safety monitoring of the coal mine shaft, based on the structural characteristics and chemical composition of the composite shaft lining of the coal mine, the fundamental structure of the electromagnetic array and the electromagnetic unit are clarified, and a multi-layer matrix simulation point overlap mapping analysis method is proposed. Based on the system modeling and simulation calculations in MATLAB software, the number and distribution law of effective mapping points between the endpoints of the electromagnetic array and the reinforced frame in the shaft lining are inferred, which... [more]
113. LAPSE:2023.36294
Biocompounds from Green Algae of Romanian Black Sea Coast as Potential Nutraceuticals
July 7, 2023 (v1)
Subject: Biosystems
Keywords: algae, antibacterial activity, antioxidant activity, Cladophora vagabonda, Enteromorpha intestinalis, nutraceuticals, nutritional constituents, Ulva lactuca
Three green algae, collected from the Romanian Black Sea coast, are studied: Ulva lactuca, Enteromorpha intestinalis, and Cladophora vagabunda, which were collected from six different coastal areas. This paper aims to identify the bioactive compounds of these green algae and their beneficial properties, in order to use them as potential nutraceuticals using different analytical methods. Pharmacognostic, microbiological, and physico-chemical methods used for the analysis of algal materials revealed a rich and diverse array of biocompounds with nutritional value. In the case of green algae, a high percentage of sulphates, carbohydrates and dietary fibers were identified. Moisture, ash, total nitrogen, protein and lipid contents were determined. The contents of pigments, vitamins, and metals determined complement the nutritional qualities of the three seaweed species studied as future nutraceuticals. The content of flavonoid and phenolic compounds identified in the composition of seaweeds... [more]
114. LAPSE:2023.36293
Investigating the Performance and Stability of Fe3O4/Bi2MoO6/g-C3N4 Magnetic Photocatalysts for the Photodegradation of Sulfonamide Antibiotics under Visible Light Irradiation
July 7, 2023 (v1)
Subject: Biosystems
Keywords: Carbon nitride, magnetic photocatalyst, sulfonamide antibiotics
In this study, an Fe3O4/Bi2MoO6/g-C3N4 magnetic composite photocatalyst was synthesized for the visible-light-driven photocatalytic degradation of sulfonamide antibiotics, specifically sulfamerazine (SM1). Characterization techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), photoluminescence spectroscopy (PL), UV-vis diffuse reflectance spectra (UV-vis), and the use of a vibrating sample magnetometer (VSM), were employed to analyze the fabricated samples. The composite exhibited efficient visible-light absorption and charge separation, with optimal photocatalytic performance achieved at a pH value of 9.0. The study reveals the importance of solution pH in the degradation process and the potential applicability of the composite for efficient magnetic separation and recycling in photocatalytic processes. The Fe3O4/Bi2MoO6/g-C3N4 magnetic composite photocatalyst demonstr... [more]
115. LAPSE:2023.36292
Formic Acid in Hydrogen: Is It Stable in a Gas Container?
July 7, 2023 (v1)
Subject: Energy Systems
Keywords: analytical chemistry, formic acid, fuel cell electrical vehicles, gas stability, gas standards, hydrogen fuel, hydrogen quality, ISO 14687, trace analysis
Formic acid is an intermediate of the steam methane reforming process for hydrogen production. According to International Standard ISO 14687, the amount fraction level of formic acid present in the hydrogen supplied to fuel cell electric vehicles must not exceed 200 nmol·mol−1. The development of formic acid standards in hydrogen is crucial to validate the analytical results and ensure measurement reliability for the fuel cell electric vehicles industry. NPL demonstrated that these standards can be gravimetrically prepared and validated at 4 to 100 µmol·mol−1, with a shelf-life of 1 year (stability uncertainty < 7%; k = 2). Stability was not affected over 1 year or by low temperature or pressure. At sub-µmol·mol−1 level, formic acid amount fraction was found to decrease due to adsorption on the gas cylinder surface; however, it is possible to certify the formic acid amount fraction after a period of 20 days and ensure the certified value validity for 1 year with an uncertainty below 7%... [more]
116. LAPSE:2023.36291
Detecting Plant-Wide Oscillation Propagation Effects of Disturbances and Faults in a Chemical Process Plant Using Network Topology of Variance Decompositions
July 7, 2023 (v1)
Subject: Process Control
Keywords: chemical process control, network analysis, oscillation propagation analysis
This work demonstrates for the first time the application of network topology of variance decompositions in analyzing the connectedness of chemical plant process variable oscillations arising from disturbances and faults. Specifically, the time-based connectedness and frequency-based connectedness of variables can be used to compute the net pairwise dynamic connectedness (NPDC), which originated as a volatility spillover index for financial markets studies in the field of econometrics. This work used the anomaly-detection benchmark Tennessee-Eastman chemical process (TEP) dataset, which consists of 41 measured variables and 11 manipulated variables subjected to various faulty operating conditions. The data analytics was performed using key functions from the R-package ‘ConnectednessApproach’ that implements connectedness computations based on time and frequency. The NPDC coefficient matrices were then transformed into network adjacency matrices for the rendering of the network topology... [more]
117. LAPSE:2023.36290
Estimation of Shale Gas Reserves: A Modified Material Balance Equation and Numerical Simulation Study
July 7, 2023 (v1)
Subject: Materials
Keywords: adsorbed gas, material balance equation, matrix shrinkage, shale gas, straight line
This study presents a comprehensive material balance equation (MBE) to estimate the reserve of shale gas reservoirs including free and adsorbed gas volume. The presented material balance equation takes into account the effect of stress change, matrix shrinkage, water volume production and influx, and critical desorption pressure. The material balance equation is converted into a linear relationship between the reservoir production and expansion parameters used during the derivation procedures that include rock-fluid properties and production history data. The proposed straight line reserve evaluation technique yields a slope of original free and absorbed gas in organic matrix, while the y-intercept yields the volume of original free gas in the in-organic matrix. A field case study of shale gas located in Australia is presented. Results show that the proposed MBE and the corresponding straight line reserve evaluation technique are rational and competent in estimating the free gas and ad... [more]
118. LAPSE:2023.36289
Pipe Flow of Viscoplastic Fluids and Analytical Predictions of Concrete Pumping Based on the Shear-Stress-Dependent Parabolic Model
July 7, 2023 (v1)
Subject: Materials
Keywords: concrete pumping, lubrication layer, pipe flow, rheology, shear-thickening, viscoplastic fluid, yield stress
This study investigates the Hagen−Poiseuille pipe flow of viscoplastic fluids, focusing on analytical predictions of concrete pumping using the shear-stress-dependent parabolic model, extending analytical studies to a nonlinear rheological model with easily accessible experimental parameters. Research novelty and highlights encompass solving the steady laminar pipe flow for viscoplastic fluids described by the parabolic model, presenting detailed results for the two-fluid parabolic model, and introducing a computational app implementing theoretical findings. The parabolic model outperforms linear models, such as the Bingham model, in accuracy by accounting for the nonlinearity in the flow curves (i.e., shear stress and shear rate relations) of pumped concrete. The influence of rheological parameters on these relations is analyzed, and their versatility is demonstrated by a Wolfram Mathematica-based application program. The analytical approach developed in this work is adaptable for oth... [more]
119. LAPSE:2023.36288
Coupled Thermal-Hydraulic-Mechanical Modeling of Near-Well Stress Evolution in Naturally Fractured Formations during Drilling
July 7, 2023 (v1)
Subject: Modelling and Simulations
Keywords: failure criterion, formation rock, natural fractures, Simulation, wellbore collapse
Naturally fractured formations usually have strong heterogeneities. Drilling and production operations in such formations can involve unwanted formation failure risks such as wellbore collapse and wellbore fracturing. This study presents a coupled thermal-hydraulic-mechanical numerical model for near-well stress evolutions during drilling in naturally fractured formations. The evolution of pressure, temperature, and geo-mechanical responses on the wellbore wall and in the near-well region is simulated. The effects of wellbore pressure, internal friction angle, and natural fracture length on formation rock risks are discussed. A failure index is used to quantify the formation rock failure risks. The existence of natural fractures magnifies the heterogeneous system response induced by drilling. Increasing the wellbore pressure from a relatively low value can improve the support for the wellbore wall, which reduces the failure risks caused by shearing. In mechanically weak formations, the... [more]
120. LAPSE:2023.36287
System Design and Mechanism Study of Ultrasonic-Assisted Electrochemical Grinding for Hard and Tough Materials
July 7, 2023 (v1)
Subject: Materials
Keywords: collaborative machining system, compound electrochemical, compound grinding, rotary ultrasonic machining
In this study, an ultrasonic-assisted electrochemical grinding (UAECG) system was designed to improve the low efficiency and tool wear in conventional grinding of hard and tough materials. In this system, multiple-field energy consisting of ultrasonic, electrochemical and mechanical grinding was used. The processing mechanism was investigated to determine the interaction mechanism between ultrasonic, grinding and electrochemical processing. The established theoretical model showed that the processing efficiency was affected by the ultrasonic amplitude, ultrasonic frequency, electrolyte conductivity and other parameters. In verifying the feasibility of UAECG machining and the effect of machining elements on machining, a series of corresponding machining experiments was conducted. Experiments showed that the machining efficiency can be improved by machining through the UAECG system. The material removal rate of W18Cr4V machining was 2.7 times higher than that of conventional grinding and... [more]
121. LAPSE:2023.36286
The Influence of Interlayer on the Development of Steam Chamber in Steam Stimulation during Heavy Oil Recovery
July 7, 2023 (v1)
Subject: Energy Systems
Keywords: cyclic steam stimulation, interlayer, preparation method, top water
Cyclic steam stimulation is an effective thermal recovery method for heavy oil recovery. The key potential mechanism is the growth of the steam chamber after steam injection. Taking the LD5X heavy oil reservoir as an example, besides the interlayer developed in this area, the top water and bottom water distribute above and below the interlayer. These factors may have adverse effects on the development of the steam chamber, thus affecting the final heavy oil exploitation. In this work, our goal is to study the effects of interlayer permeability and well−interlayer distance on CSS performance (in the presence of top and bottom water). We developed a high-temperature-resistant interlayer. Based on the simulated interlayer, the field scale model was converted into a laboratory element model through the similarity criterion. In order to quantitatively evaluate the performance of steam stimulation, a thermal detector was used to measure the dynamic growth of the steam chamber and record the... [more]
122. LAPSE:2023.36285
Evaluation of Reconstruction Potential for Low-Production Vertical Wells of CBM in the Southern Qinshui Basin
July 7, 2023 (v1)
Subject: Energy Systems
Keywords: CBM vertical well, low production, Qinshui Basin, reconstruction potential evaluation
Production practice has shown that not all low-production coalbed methane (CBM) wells can be reconstructed into high-production wells through secondary stimulation, so it is necessary and timely to establish an evaluation index system, form an evaluation method, and evaluate the reconstruction potential of low-production wells. Based on the development practice of CBM in the southern Qinshui Basin, this paper analyzes the influencing factors of low production in vertical wells from the aspects of coal and rock reservoir conditions, drilling and completion engineering, and drainage engineering. It is proposed that the evaluation of the reconstruction potential of low-production wells should focus on the quality of CBM resources, the difficulty of CBM desorption and diffusion, and the degree of damage to coal reservoirs caused by the initial reservoir stimulation. Twelve parameters, including gas content, gas saturation, reservoir pressure gradient, critical desorption−reservoir pressure... [more]
123. LAPSE:2023.36284
Increasing Surface Functionalities of FeCl3-Modified Reed Waste Biochar for Enhanced Nitrate Adsorption Property
July 7, 2023 (v1)
Subject: Environment
Keywords: iron modification, mechanism, nitrate adsorption property, reed waste biochar, surface functionalities
Ferric chloride (FeCl3) modified reed straw-based biochar was synthesized to remove nitrate from aqueous solutions and achieve waste recycling. The adsorption of nitrate onto Fe-RBC-600 adsorbents could be described by the pseudo-second-order kinetic model and fitted to Langmuir adsorption, and the maximum adsorption capacity predicted using the Langmuir model was 272.024 mg g−1. The adsorbent characterization indicated that a high temperature of 600 °C and an oxygen-poor environment could develop a hydrophobic surface and O-containing functional groups on the biochar, which provided more binding sites for Fe3+/Fe2+ attachment and increased the surface functionality of Fe-RBC-600 with iron oxide formation. The increasing surface functionality successfully enhanced the nitrate adsorption property. The mechanism of nitrate adsorption was mainly attributed to the physical adsorption onto the positive surface and sequential chemical reduction by Fe2+, and the electrostatic adsorption by pr... [more]
124. LAPSE:2023.36283
Recent Applications and Prospects of Nanowire-Based Biosensors
July 7, 2023 (v1)
Subject: Biosystems
Keywords: biological sensors, DNA/RNA detection, nanowires, neurotransmitter detection, protein detection, viral detection
High-sensitivity biomedical sensors could make it possible to detect and classify chemical and biological species in a variety of applications, from disease diagnosis to medication discovery, thus, boosting the likelihood of life-saving intervention. Synthesized nanowires have already produced advancements in a variety of sectors, including biological sensors over the last decade. When compared to macro-sized materials, the nanowires’ large surface area-to-volume ratio increased sensitivity. Their applications for biomarker, viral, and DNA detection, as well as drug discovery, are also discussed. Self-powering, reusability, sensitivity in high ionic strength solvents, and long-term stability are all examples of recent developments. Shortly, the nanowire is likely to lead to major improvements in biomedical sensors. This review provides a full overview of the nanowire sensor’s working principle and production procedure. We have discussed how to produce nanowires that can be utilized as... [more]
125. LAPSE:2023.36282
Thermal Stability and Kinetics of Degradation of Moxonidine as Pure Ingredient vs. Pharmaceutical Formulation
July 7, 2023 (v1)
Subject: Materials
Keywords: drug degradation, isoconversional methods, kinetic study, moxonidine, thermal stability
The stability of active pharmaceutical ingredients (APIs) and the corresponding pharmaceutical formulations are nowadays of great importance in pharmaceutical research and technology. The quality of an API or of finished pharmaceutical products (FPPs) is time dependent under the influence of several parameters, such as light and air exposure, temperature, and humidity. Additionally, the stability profile of an API is influenced by the formulation composition, due to the presence of excipients or by the characteristic of the packaging materials. In this sense, the main objective of this study was to analyze the degradation kinetics of the antihypertensive drug moxonidine as a pure ingredient (MOX) and in two different solid mixtures, one corresponding to a pharmaceutical formulation (MOXTAB) and the other to an enriched pharmaceutical formulation in MOX (MOXMIX). As investigation techniques, FTIR (Fourier transform infrared) spectroscopy and TG/DTG/HF analysis were employed, while the t... [more]