Law Model Research Articles

Performance Evaluation of Rankiya (Grewia venusta) as a Polymer for Enhanced Oil Recovery-Polymer Flooding

Polymer Flooding is an enhanced oil recovery method where high-molecular-weight polymers are added into the injected water, in order to increase the viscosity of injection fluid, improve volumetric sweep efficiency, and finally increase the oil recovery factor. Most research studies focused on the use of partially hydrolysed polyacrylamide (HPAM), xanthan gum, SPG, HEC as flooding fluid. This work focused on investigating the potential of natural polymer - Grewia venusta plant tree in formulating flooding fluid for polymer flooding operation. The polymer was prepared from the mucilage extracted from the inner stem bark of Grewia venusta. Rheological characterization shows that the formulated Grewia venusta mucilage (GVM)-based flooding fluid maintained high viscosity under very high salinity, also exhibits shear thinning behaviour which obeys power law model with fluid behaviour index n = 0.32 and consistency index K= 6.3 at highest GVM concentration of 3000 ppm, similarly revealed that GVM-based flooding fluid was stable when subjected to high salinity of 130,000 ppm and temperature, up to 90 oC an inconsequential decrease in viscosity was experienced. These indicate its potential in enhancing oil recovery process. Core flooding analysis was carried out on an outcrop core sample with porosity and permeability of 26.1% and 218 mD respectively. Core flooding analysis revealed that: with increase in GVM concentration of 500, 750, 1000 and 2000 ppm oil recovered against time were 55.1%, 62.6%, 69.2% and 72.9% respectively, beyond 2000 ppm GVM concentration (optimum concentration), increase in polymer concentration did not bring about an increase in oil recovery, this finally resulted to an incremental recovery of 29% original oil in place (OOIP).

Positive Bias Temperature Instability in SiC-Based Power MOSFETs.

This paper investigates the threshold voltage shift (ΔVTH) induced by positive bias temperature instability (PBTI) in silicon carbide (SiC) power MOSFETs. By analyzing ΔVTH under various gate stress voltages (VGstress) at 150 °C, distinct mechanisms are revealed: (i) trapping in the interface and/or border pre-existing defects and (ii) the creation of oxide defects and/or trapping in spatially deeper oxide states with an activation energy of ~80 meV. Notably, the adoption of different characterization methods highlights the distinct roles of these mechanisms. Moreover, the study demonstrates consistent behavior in permanent ΔVTH degradation across VGstress levels using a power law model. Overall, these findings deepen the understanding of PBTI in SiC MOSFETs, providing insights for reliability optimization.

Development of a Probabilistic Correlation between the Gamma Ray Index and Shale Volume Factor to Improve Resource Estimation for the Niger Delta Basin, Nigeria

The shale volume factor is among the critical petrophysical parameters for reservoir characterization and formation evaluation. Inaccurate estimates of the shale volume factor can lead to poor reserves or resource estimates and wrong business decisions. While the current industry standard is to estimate the shale volume factor from the gamma ray logs using the concept of the gamma ray index, a relationship between the shale volume factor and the gamma-ray index needs to be established for any region/basin under consideration. For most applications in the Niger Delta Basin, a linear relationship is often assumed. However, there is no proven relationship between the shale volume factor and the gamma-ray index for the formations in the Niger Delta Basin. This paper proposes a new shale volume factor prediction correlation for the Niger Delta Basin in Nigeria. The correlation development is based on establishing a relationship between the shale volume factor obtained from cores and the gamma ray index obtained from petrophysical logs for over thirty wells drilled across the Niger Delta Basin. The results show that the relationship between the shale volume factor and the gamma-ray index is not linear as often assumed but a power law model. The new probabilistic correlation predicts lower shale volume factors than the linear model for all ranges of the gamma-ray index. This recent correlation will significantly impact how the hydrocarbon resources and reserves are quantified in the Niger Delta Basin.

Corruption and controlling shareholders

Abstract Controlling shareholders have been directly involved in some of the largest and most consequential bribery scandals in the world over the course of the last decade. Nevertheless, the academic literature and the dominant international model of anticorruption law have neglected the dynamics and implications of controlling shareholder involvement in the payment of bribes. We argue that controlling shareholders, especially in family-controlled firms, may be uniquely positioned to lead corrupt schemes. We then analyze the incidence of this phenomenon in recent U.S. enforcement actions under the FCPA and in Brazilian enforcement actions under the Car Wash (Lava Jato) anticorruption operation. Controlled companies account for a minority of the FCPA cases, but for a large majority of the Brazilian cases. Controlling shareholders were implicated in a significant portion of actions against controlled companies in both contexts. We argue that the dominant international model, which is premised on organizational liability and incentives for compliance programs, is ill-suited to addressing cases of bribery led by controlling shareholders, and call for a distinct array of legal responses.

Influence of Magneto-hydrodynamic with Williamson Nanofluid Flow Control of Forcheeimer Model under Chemical Reaction

Objective: The research focused on Williamson's nonlinear governing flow on Magneto hydrodynamic incompressible, steady fluid over a porous stretching sheet in a two-dimensional direction. The permeable stretching sheet embedded by Williamson fluid is based on the flow model of non-Darcy Forchheimer law with chemical reaction. This article concentrated on an energy equation dominated by the dissipation parameter analysis. Methods: The governing mathematical partial derivative formulations are changed to a system of ordinary differential formulations with appropriate similarity transformation. The mathematical formulations are evaluated employing the numerical method of the R-K fourth-order scheme. MATLAB software bvp4c is used for computing numerical results. The numerical results and graphs were successfully demonstrated with the R-K fourth-order system. Findings: For the influence of Williamson non-Newtonian, non-fluid observed emerging dimensionless quantifiers such as Williamson number, porous, electric, thermophoresis, Brownian motion, Prandtl, and Schmidt dimensionless number respectively. The performance of non-dimensional parameters is investigated in detail. Novelty: As described in the results, Williamson's non-Newtonian nanofluid under the influence of magneto-hydrodynamics is mentioned as a new value to the existing literature. The gained results are the innovative study of the influence of chemical reaction on Williamson non-Newtonian nanofluid and magnetic strength and reported on dimensionless parameters. Keywords: Electric parameter, Williamson Nanofluid, Darcy-Forchheimer, Viscous dissipation, Chemical reaction quantifier

Unveiling thermal and hemodynamic effects of aneurysm on abdominal aorta using power law model and finite element analysis

The objective of this study is to find causes of aortic diseases and investigating the ways for better treatment. The governing system of equations has been demonstrated to account for characteristics of blood. The governing system of equation has been solved using the finite element method with appropriate boundary conditions. We analyzed into the relationship between flow characteristics via the aneurysmal abdominal aorta and the aneurysm height, aneurysm length, and non-Newtonian behavior. It investigates how thermal and hemodynamics effects change across the abdominal aortic aneurysm. The velocity, pressure, and temperature surface plots of the results are displayed. There have also been graphic displays of line graphs of axial velocity, radial velocity, axial pressure, radial pressure, axial temperature and radial temperature across the aneurysm. The blood flow simulations obtained results show that increasing blood temperature, pressure and intake velocity all contribute to an increase in viscosity. The results indicate that while the temperature varies little to not at all, the blood flow pressure decrease and velocity significantly vary.

Patterns of electrical properties change of heavy metal-organic compound contaminated media in soil-groundwater systems: From laboratory experiments to site application

Differences in electrical properties of media are the basis for determining the type and extent of contamination using geophysical methods. However, differences in heavy metals and organic matter complicate the electrical properties of compound-contaminated media, and existing geophysical methods cannot independently identify compound contamination. Therefore, this study proposes a geophysical detection system that combines electrical resistance tomography (ERT) and induced polarization methods and establishes a solid theory as the basis for the system application through laboratory experiments, model analysis, and site applications. The study reveals that as the organics volume proportion increases, the resistivity and normalized chargeability of contaminated media increased slowly, followed by a rapid increase, and finally reached a stable state. The specific type of compound significantly influences the electrical properties, while the resistivity of different kinds of compound-contaminated media reaches the same maximum value as the organics volume proportion increases. The medium type determines the contaminated media's lower resistivity limit and upper normalized chargeability limit. Additionally, the interplay between heavy metal type, content, and medium complicates the electrical properties of the media, with the compound type exerting a significant impact on resistivity. Archie's law and random forest modeling reveal that the inflection point for resistivity change occurs at 40 % and 80 % organics volume proportions, while the inflection point for normalized chargeability change occurs at 30 % and 70 % organics volume proportions in compound-contaminated media. These inflection points depend on the types of compounds, compositions, proportions, and media, and their importance for the electrical properties of the media changes with the increasing organics volume proportion. Based on the changing patterns of resistivity and normalized chargeability in heavy metal-organic compound contaminated media, the modified geophysical detection system can effectively identify the pollution type and intensity, which provides accurate pollution information to develop effective treatment strategies.

Preparation and Rheological Properties of the PVA/CMC/Gel Composite for Mining.

A composite gel material with an interpenetrating network structure was formed using the chemical cross-linking method. The viscosity, yield stress, and thixotropy of a poly(vinyl alcohol)/carboxymethyl cellulose/gelatin (PVA/CMC/Gel) composite gel slurry with different ratios were tested using a viscometer, and the interaction between the surface of the gelling agent and the cross-linking agent was analyzed by calculating the frontline orbital energy of a single polymer material molecule. The seepage diffusion characteristics of the composite gel in a goaf were then studied through a numerical simulation. The results indicate that the PVA/CMC/Gel composite gel exhibits shear thinning behavior following the power law model and behaves as a pseudoplastic fluid. The optimal ratio for the composite gel at 30 °C is determined as follows: 30 wt % for the gelling agent (PVA/(Gel + CMC) = 20:10), 4 wt % for the cross-linking agent, 3.09 wt % for the carbide slag, 7.5 wt % for the alcohol amine solution, and 0.5% sodium dodecyl sulfonate + 0.1% alkyl glycoside for the foaming agent. Gel exhibits the lowest energy band gap (0.096 eV), indicating strong reaction activity and strong reaction with the cross-linking agent (sodium tetraborate). PVA has the largest energy band gap (0.238 eV), strong molecular stability, and weak reaction with the cross-linking agent (sodium tetraborate). When the dip angle of the goaf is 4° and the injection time is 40 min, the composite gel tends to diffuse more easily along the dip. The investigation into the rheological properties of the PVA/CMC/Gel composite gel holds significant importance in the design of coal mine pipeline transportation and understanding diffusion flow in goaf.

Thermo-hydraulic transport characteristics of non-Newtonian nanofluid flow through wavy channel: Influence of nanoparticle volume fraction and Prandtl number

The present study numerically investigates the thermal-hydraulic transport characteristics of non-Newtonian nanofluid flowing through the trapezoidal wavy channel. Constitutive behavior of non-Newtonian fluid was used to elucidate the power law model. The average Nusselt number, pressure drop, and performance factor are evaluated for varying volume concentration of nanoparticles (0 ≤ ϕ ≤ 0.04) and Prandtl number (Pr = 0.76, 1, 6.39, 20, 50, and 100) at different values of Reynold number (Re = 50 and 500), power index values (n = 0.5, 1, 1.5) and wave phase shift (θ = 0°, 90°and 180°). An increase in average Nusselt number and pressure drop was observed for increasing volume concentration of nanoparticles, Prandtl number, and Reynold number. At the same time, the performance factor decreases with an increase in ϕ, Pr, and Re. The heat transfer rate was observed to be more for shear thinning fluids than shear thickening fluids.

Chemical vapor deposition-based synthesis of cost-effective binder-free nanostructured Ag/MoS2/Ni–F electrode material for portable energy storage devices

The synthesis of novel electrode materials (E-Ms) is the demand of scientific community to overcome the energy crisis in developing countries. Hereon, the molybdenum disulfide (MoS2) and silver-wrapped MoS2 (Ag/MoS2) E-Ms are synthesized on hierarchical-nickel foam (Ni–F) via a cost-effective chemical vapor deposition technique. The synthesized E-Ms are characterized in terms of structure, chemical bonding, surface morphology, weight percentage of elements, porosity and energy storage capability. The X-ray diffraction analysis is indicated that by wrapping of Ag species, the diffraction peaks associated with MoS2 material not only moved to higher Bragg's angles but their peaks intensities are also lowered which showed the existence of structural defects in the synthesized E-Ms. The surface area of cauliflower like Ag/MoS2/Ni–F E-Ms (170 m2g-1) is higher than the surface area (60 m2g-1) of MoS2/Ni–F E-Ms. The cauliflowers based Ag/MoS2/Ni–F E-Ms is presented supreme specific capacitance of 4200 Fg-1 as compared to MoS2/Ni–F E-Ms (2518 Fg-1) at 1Ag-1. The implementation of power law and Dunn's model is demonstrated that the synthesized E-Ms can behave like a battery and supercapacitor (0.67 < b < 0.92) nature. The diffusive-controlled contribution for cauliflower-based synthesized E-Ms is 97 % at 5 mVs−1 and became 88 % at 70 mVs−1. The assembled asymmetric supercapacitor (ASC) device is exhibited the specific capacitance of 957 Fg-1, energy density of 366–284 Whkg−1 and power density of 1494–14110 Wkg-1. The ASC device could sustain the capacitance retention of 94 %, Coulombic efficiency of 99 % even for 20000 cycles in contrast to capacitance retention of 95 % and Coulombic efficiency of 97.89 % of the synthesized E-Ms.

Reilly’s gravity law adapted to finance

The present paper proposes new indicators that explain the pricing of the unitary pure interest rates and interests by adapting previous Reilly’s Law (RL) models of urban economics and regional economics and Financial Gravity (FG) models for financial services. A panel dataset of 114 countries for 1967-2021 is handled, applying the OLS methodology. The results show the higher explanatory power of the adaptation of the FG models rather than the proposed adaptation of the RL ones. Purpose: This paper tries to adapt previous Gravity Equations from Urban Economics to Finance and empirically checks whether they behave better than the recently found Financial Gravity (FG) models. For that, new indicators are provided jointly with their adaptations to Ordinary Least Square (OLS) methods. Additionally, an economic perspective of the bid-asks of financial products is provided. Design/methodology/approach: OLS methods are used to check the desirability and accuracy of the new indicators. A panel dataset of 114 countries for 1967-2021 is handled, applying the OLS methodology. Findings: The most adequate are the FG models after the empirical check, providing the desirable properties of those models. The results show the higher explanatory power of the adaptation of the FG models rather than the proposed adaptation of the RL ones. Originality: This is the first paper, to the author’s knowledge, on providing an adaptation of Reilly’s Law from urban economics models to finance, also providing empirical evidence after adapting these models to linear expressions for applying OLS methods. We also provide evidence on the statistical equality between the unitary pure interest of loan and deposit interests, confirming the good properties of the FG models.

Insight into variable thermophysical features of the functionally graded porous annular fin influenced by internal heat and thermal radiation

The present analysis considers a functionally graded porous fin of radiating shape. The fin is subject to thermal-dependent internal heat generation and radiation. Two different cases are performed where the thermal conductivity varies linearly and exponentially with temperature. For simplicity, it is assumed that the material properties of the porous fin change along the fin radius based on a power-law function, with a consistent Poisson’s ratio. The Fourier’s law and Darcy model are used to model the ordinary differential equation (ODE) that governs the fin problem. The equation’s components have been arranged into dimensionless parameters, and their effects on fin efficiency, thermal stresses, and heat transfer rate are discussed and illustrated visually. The analysis comprehensively addresses the radial and tangential stresses and their thermal effects on the fin. It shows that near the base region of the fin, the tangential stress demonstrates less compression, and near the tip radius, there is smaller tensile stress. It has been found that for heat generation coefficient G=0.1 and εG=0.1 the percentage increase in efficiency is 28.1927%.

MODELING THERMAL BEHAVIOR IN HIGH-POWER SEMICONDUCTOR DEVICES USING THE MODIFIED OHM’S LAW

This paper addresses the challenge of thermal management in high-power semiconductor devices, where increasing power densities and complex operating environments demand more accurate thermal prediction methods. Traditional approaches often rely on simplified models that do not account for the crucial factor of temperature-dependent resistance variations. This limitation leads to inaccurate device temperature predictions, potentially compromising device reliability. This work proposes a novel approach for thermal management by introducing the first empirical application of a Modified Ohm’s Law. This modified law incorporates an exponential term to account for the non-linear relationship between temperature, current, and resistance. The paper demonstrates through simulations and empirical validation that the Modified Ohm’s Law offers a more accurate representation of thermal behavior compared to the standard version. This translates to more precise predictions of device temperature, especially during periods of rapid temperature changes. The validation process goes beyond simply establishing the Modified Ohm’s Law. It provides valuable insights into the thermal dynamics of the device, allowing for the refinement of simulation parameters used to assess various cooling strategies. These strategies include simulating different heat sink geometries and materials, modifying airflow rates over the device’s surface, and exploring the impact of Thermal Interface Materials (TIMs) between the device and the heat sink. By incorporating these elements, the simulations provide a more comprehensive picture of the device’s thermal behavior under various operating conditions and cooling configurations. Ultimately, this paper not only advances the theoretical understanding of thermal management but also offers practical benefits. Through enabling more accurate thermal predictions, the Modified Ohm’s Law model paves the way for informed decision-making in device design and optimization.

Micromechanical modeling of longitudinal compression behavior and failure mechanism of unidirectional carbon fiber reinforced aluminum composites involving initial fiber misalignment

AbstractA micromechanical model with realistic initial fiber misalignment (IFM) was developed to simulate the longitudinal compression behavior of unidirectional carbon fiber/aluminum composites. The matrix and fiber were modeled using ductile damage law and brittle fracture model, respectively. The interfacial properties were firstly determined by the single‐fiber push‐out and transverse tensile tests, and the cohesive zone model was adopted to capture the interfacial behavior. The calculated compressive response curve is in alignment with the experimental data. Compression failure can be attributed to fiber kinking, possibly triggered by the matrix shear damage. The increase of IFM angle makes the failure mode being transformed from fiber crushing to fiber kinking, along with a significant decrease in compressive strength. With the fiber content increasing, the compressive strength increases first and then decreases, while the compressive modulus increases monotonically. Increasing interfacial strength significantly improves the compressive strength, but this is limited by the matrix properties.

Extraction of Bioactive Secondary Metabolites from Citrus Maxima Peel Via Pressurized Hot Water Extractor for the Synthesis of Iron Oxide Nanoparticles

Using bioactive secondary metabolites (BSM) from Citrus maxima peel extract, this work investigated a green method of synthesizing magnetite iron oxide (Fe3O4) nanoparticles (NPs). The BSM acts as a reducing cum stabilizing agent in the process. The optimization of the BSM parameters were conducted through response surface methodology (RSM). The optimal condition obtained in this study for pressurized hot water extractor (PHWE) extraction was temperature of 94.96 °C, solvent-to-solid ratio of 29.7 ml/g and extraction time of 27.6 min. BSM Yield of 49.31 % could be obtained based on this condition. The formation of Fe3O4 NPs were detected using the FTIR analysis with the absorption peaks observed at around 590 and 580 cm−1. X-ray diffraction results matched standard magnetite Fe3O4 patterns with planes at (220), (311), (400), (511) and (440). Field emission scanning electron microscopy (FESEM) results showed that the magnetite Fe3O4 NPs synthesized in this study predominantly appeared in spherical shape. The extraction process's kinetics were examined using various empirical models, including the Elovich’s model, Peleg’s model, Power law and parabolic diffusion model. All applied models were found to be well fitted with the measured data from experiment, with R2 values exceeding 0.9. Notably, the Peleg’s model exhibited the highest R2, the smallest RMSD, and the least significant p-values, indicating its superior performance.

Rheology of automotive adhesives during dispensing: A direct comparison of epoxy and rubber based systems via drag and pressure driven flows

Construction of vehicles requires adhesive dispensing for body-in-white assembly, hemming of closure panels, decking of windshields and the manufacture of battery packs. Knowledge of the rheological properties of adhesives applied using common dispensing systems is important for optimization of dispensing and application conditions. However, flow behavior of adhesives at shear rates used in dispensing is not well understood. Therefore, this study combines parallel plate and capillary rheology techniques to directly compare the rheological properties of an epoxy structural adhesive used in hemming applications and a rubber ‘topical sealer’ used to seal water leak paths across the range of shear rates observed in dispensing. Shear viscosity (η) and complex viscosity (η*) master curves were created from time-temperature-superposition (TTS) of steady shear and dynamic oscillatory data. Both adhesives did not follow the Cox-Merz rule. It was found that the Carreau-Yasuda model fit the steady shear viscosity master curve of the epoxy structural adhesive, while a simpler power law model fit the steady shear viscosity master curve of the rubber topical sealer. An inexpensive capillary rheometer was developed to simulate the adhesive dispensing process. Viscosity data was corrected for entrance pressure losses and a non-Newtonian flow front using Bagley and Weissenberg-Rabinowitsch corrections, respectively. It was observed that complex viscosity master curves better predicted viscosity during dispensing, as compared to steady shear viscosity master curves. Linear stress ramp measurements showed that the adhesives have widely different yield stresses, while the capillary rheometry measurements showed they have similar viscosities during dispensing. Furthermore, the capillary rheometer ‘shot meter’ pressures were related to the apparent and doubly corrected viscosity values through power law functions. A new quality control method based on the capillary rheology data is proposed.

Flexible Permeable-Pavement System Sustainability: A Methodology for Stormwater Management Based on PM Granulometry

Permeable-pavement design methodologies can improve the hydrologic and therefore the environmental benefits of rural and urban roadway systems. By contrast, conventional impervious pavements perturb the hydrologic cycle, altering the relationship between the rainfall loading and runoff response. Impervious pavements create a hydraulically conductive interface for the transport of traffic-generated chemicals and particulate matter (PM), deleteriously impacting their proximate environments. Permeable-pavement systems are countermeasures to mitigate hydrologic, chemical, and PM impacts. However, permeable pavements are not always equally implementable due to costs, PM loadings, and design constraints. A potential solution to facilitate environmental benefits while meeting the traffic load capacity is the combination of two filtration systems placed at the pavement shoulders and/or pedestrian sidewalks: a bituminous-pavement open-graded friction course (BPFC) and an aggregate-filled infiltration trench. This solution is presented in this manuscript together with the methodological framework and the first results of the investigations into designing and validating such a combined system. The research was conducted at the laboratories of the Polytechnic University of Bari and the University of Florida, while an operational and full-scale physical model was constructed in Bari, Italy. The first results presented characterize the PM deposition on public roads based on granulometry (particle size distributions (PSDs) and particle number densities (PNDs)). Samples (n = 16) were collected and analyzed at eight different sites with different land uses, traffic, and pavements from different cities (Bari and Taranto, Italy). The PM analysis showed similar distributions (PSDs and PNDs), except for two samples. The gravimetric-based PSDs of the PM had granulometric distributions in the sand-size range. In contrast, the PNDs, modeled by a Power Law Model (PLM) (R2 ≥ 0.92), illustrated an exponentially increasing number of particles in the fine silt and clay-size range, representing less than 10% of the PSD mass. Moreover, the results indicate that PM sourced from permeable-pavement systems has differing impacts on the pavement service life.

Linguistic Properties of Emojis: A Quantitative Exploration of Emoji Frequency, Category, and Position on Twitter

ABSTRACT Emojis in digital communication have drawn increasing academic attention. Qualitative studies mainly rely on a presumption that emojis share similar properties with units of natural language. It remains to be explored with quantitative methods whether emojis exhibit the same or similar behaviour from linguistic units (like words, morphemes). This study investigates emoji features in relation to language properties based on Zipf’s law and linear regression models. Results show that, firstly, the rank frequency distribution of emojis can be well fitted by Zipf’s law, and the parameters of emoji distribution are closer to those of written language. Secondly, most emoji categories tend to occur in the latter half of the tweet; while in some cases, they can also be at the beginning or in the middle of a tweet. Thirdly, the relative position of the more frequently-used emojis will be further back in the tweet. When emojis’ frequencies are relatively greater, their categories vary more in terms of their positions. In general, our quantitative findings suggest that emojis display linguistic properties to some extent. Our exploratory study demonstrates the value of applying linguistic laws and quantitative methods to investigate emoji features, extending the application of quantitative linguistic methods into emoji studies.

Analysis of the Sorption Properties of Molecularly Imprinted Polymers as Materials for Potential Monitoring of the Amount of Amoxicillin in an Aqueous Environment

ABSTRACT This work describes a procedure for obtaining molecularly imprinted polymers (MIPs) toward amoxicillin based on methyl methacrylate. To characterize the polymers synthetized, physicochemical and sorption properties were analyzed. The influence of the main parameters on the adsorption efficiency was investigated (the monomers composition of materials, contact time, initial concentration, and regeneration conditions). The adsorption isotherms were fitted by Freundlich, Langmuir, and Dubinin–Radushkevich models. Pseudo-first-order, pseudo-second-order, intraparticle diffusion, and second Fick’s law models were used to fit the kinetic data. Molecularly imprinted polymer which was obtained using 5 wt.% of amoxicillin in relation to the monomers, characterized by the highest sorption value of 4.8 mg/g. This polymer showed selective properties in competition with gentamicin and norfloxacin. Furthermore, in the case of testing imprinted polymers in real samples, materials with an imprint were characterized by higher sorption values compared to those without an imprint (3.27 and 2.02 mg/g, respectively). For the first time, for this type of MIP, we conducted research for regenerating. Water solutions with pH 3 or 9, 1% acetic acid, and ethanol were tested as regeneration solutions. Molecularly imprinted polymer regeneration for the most effective regeneration solution was carried out on SPE columns, allowing a 94% cleaning of the sorption material.

Strong gravitational lensing’s ‘external shear’ is not shear

ABSTRACT The distribution of mass in galaxy-scale strong gravitational lenses is often modelled as an elliptical power-law plus ‘external shear’, which notionally accounts for neighbouring galaxies and cosmic shear along our line of sight. A small amount of external shear could come from these sources, but we show that the vast majority does not. Except in a handful of rare systems, the best-fitting values do not correlate with independent measurements of line-of-sight shear: from weak lensing in 45 Hubble Space Telescope images, or in 50 mock images of lenses with complex distributions of mass. Instead, the best-fit external shear is aligned with the major or minor axis of 88 per cent of lens galaxies; and the amplitude of the external shear increases if that galaxy is discy. We conclude that ‘external shear’ attached to a power-law model is not physically meaningful, but a fudge to compensate for lack of model complexity. Since it biases other model parameters that are interpreted as physically meaningful in several science analyses (e.g. measuring galaxy evolution, dark matter physics or cosmological parameters), we recommend that future studies of galaxy-scale strong lensing should employ more flexible mass models.