Experimental Conditions Research Articles

Evaluation of short-circuited electrodes in combination with dark fermentation for promoting biohydrogen production process

Short-circuited electrodes, in combination with dark fermentation, were evaluated in a biohydrogen production process. The system is based on an innovative design of a non-compartmented electromicrobial bioreactor with a conductive tubular membrane as cathode and a graphite felt as anode. In particular, the electrode specialization occurred when the bioreactor was inoculated with manure as the whole medium and when a vacuum was applied in the tubular membrane, for allowing continuous extraction of gaseous species (H2, CH4, CO2) from the bioreactor. This specialization of the electrodes as anode and cathode was further confirmed by microbial ecology analysis of biofilms and by cyclic voltammetry measurements. In these experimental conditions, the potential of the electrochemical system (short-circuited electrodes) reached values as low as −320 mV vs. SHE, associated with a significant bioH2 production. Moreover, a higher bioH2 production occurred and a potential of the electrochemical system as low as −429 mV vs SHE was temporarily observed, when additional heat treatments of the whole manure were applied in order to remove methanogen microorganisms (i.e., hydrogen consumers). In the bioreactor, the higher production of bioH2 would be promoted by electrofermentation from the current flow observed between short-circuited anode and cathode.

Sorption Efficacy of Weathered Basalt Rock for Metal Ions of Nuclear Importance

Background:: A safe and long-term isolation of radionuclides is crucial for efficient waste management in the nuclear fuel cycle. Clay minerals of geological origin are considered candidate barrier materials for the sequestration of nuclear waste for geological disposal applications. Objective:: The present study encompasses a systematic characterization of weathered basalt rock and the influence of its constituent clay minerals (formed mainly due to the weathering process) in the uptake of metal ions of nuclear importance, such as cesium (Cs+) and strontium (Sr2+). Methods: The structural profile of the weathered basalt has been investigated using different analytical techniques, including polarizing microscope, XRD, FTIR and EDXRF. The sorption behaviour of the rock sample for Cs+ and Sr2+ has been investigated in a comprehensive batch mode by varying the experimental conditions. The analytical findings for structure and batch sorption performance of the material have been further correlated to understand the influence of different parameters on the uptake of metal ions and the underlying mechanism. Results:: Structural analyses confirmed the presence of clay minerals viz., kaolinite, illite and montmorillonite in the sample. A comprehensive sorption performance assessment carried out in batch mode at different experimental conditions revealed that the uptake of both the metal ions was rapid and dependent on initial metal ion concentration and solution pH. The uptake of Cs+ ions was found to be higher as compared to the Sr2+ ions. EDXRF analysis confirmed the loading of Cs+ and Sr2+ on the weathered basalt. Experimental batch sorption data presented a better agreement with the theoretical Freundlich isotherm pertaining to the heterogeneous nature of the sorbent. Conclusion:: The studies highlight that the clay minerals formed by structural alteration of basalt rock upon intense weathering could be very useful in fixing the nuclear fission waste components such as Cs+ and Sr2+.

Synthesis, Characterization, and Optimization of Novel Furan-ring Fused Chalcones via Radical Cyclization of α,β-Unsaturated Ketones and Cyclic Ketone

Abstract: Novel Furan-ring Fused Chalcones (FFC) were synthesized using a radical cyclization reaction of α,β-unsaturated ketones with cyclic ketone as the model reaction to attain this goal. In this study, traditional and microwave-assisted methods for the efficient and cost-effective synthesis of furan-ring fused chalcones in mild reaction conditions are compared and optimized. The goal is to develop a reliable and adaptable synthetic technique that may be used to produce these useful chalcone derivatives quickly and effectively. The optimal experimental conditions for these reactions were carefully determined using two independent methodologies: conventional (Method A) and microwave (Method B). The results indicated that the proposed method B could be used effectively in the future to synthesize novel furans with short reaction times and acceptable yields (87-94 %), and products were purified by column chromatography and preparative thin layer chromatography (PTLC). All new compounds were characterized by 1H-NMR, 13C-NMR, LC-MS, and elemental analyses.

Simulation model of carbon capture with MEA and the effect of temperature and duty on efficiency

Humans continue to rely on fossil fuels to generate electricity. In other words, fossil fuels are the world's largest energy producers. Fossil fuels produce significant carbon dioxide, mostly in areas where humans live. Although the share of carbon dioxide produced in big cities is minimal compared to the carbon dioxide production of volcanoes, the production of carbon dioxide in big cities has destructive effects. Process Simulator is utilized to evaluate the effectiveness of their simulation model by subjecting it to various experimental conditions, including liquid loading, temperature, and CO2 absorption (PPS). Comparing empirical and simulated mass transfer coefficients distinguishes this study from others. This procedure consists of two steps: Carbon dioxide (CO2) absorption in a solvent produces highly concentrated CO2 gas following solvent regeneration. A chemical adsorption process's scalability depends on accurate simulation models, typically validated using data from a pilot plant. With the aid of this study, a simulation model of a desorption column is constructed with ASPEN PLUS and 42% MEA validated. In addition, the effect of the weight percentage of 20-42 MEA in the inlet stream on the efficiency is investigated, and the influence of the MEA inlet temperature on system efficiency is examined. Then, the recommended temperature is confirmed based on the MEA's heat tolerance capacity of 303 Kelvin.

PreVR: Variable-Distance Previews for Higher-Order Disocclusion in VR.

The paper introduces PreVR, a method for allowing the user of a VR application to preview a virtual environment (VE) around any number of corners. This way the user can gain line of sight to any part of the VE, no matter how distant or how heavily occluded it is. PreVR relies on a multiperspective visualization that implements a higher-order disocclusion effect with piecewise linear rays that bend multiple times as needed to reach the visualization target. PreVR was evaluated in a user study ($\mathrm{N}=88$) that investigates four points on the VR interface design continuum defined by the maximum disocclusion order $\delta$. In a first control condition (CC0), $\delta=0$, corresponds to conventional VR exploration with no preview capability. In a second control condition (CC1), $\delta=1$, corresponds to the prior art approach of giving the user a preview around the first corner. In a first experimental condition (EC3), $\delta=3$, so PreVR provided up to third-order disocclusion. In a second experimental condition (ECN), $\delta$ was not capped, so PreVR could provide a disocclusion effect of any order, as needed to reach any location in the VE. Participants searched for a stationary target, for a dynamic target moving on a random continuous trajectory, and for a transient dynamic target that appeared at random locations in the maze and disappeared 5s later. The study quantified VE exploration efficiency with four metrics: viewpoint translation, view direction rotation, number of teleportations, and task completion time. Results show that the previews afforded by PreVR bring a significant VE exploration efficiency advantage. ECN outperforms EC3, CC1, and CC0 for all metrics and all tasks, and EC3 frequently outperforms CC1 and CC0.

Self-Guided DMT: Exploring a Novel Paradigm of Dance Movement Therapy in Mixed Reality for Children with ASD.

Children diagnosed with Autism Spectrum Disorder (ASD) often exhibit motor disorders. Dance Movement Therapy (DMT) has shown great potential for improving the motor control ability of children with ASD. However, traditional DMT methods often lack vividness and are difficult to implement effectively. To address this issue, we propose a Mixed Reality DMT approach, utilizing interactive virtual agents. This approach offers immersive training content and multi-sensory feedback. To improve the training performance of children with ASD, we introduce a novel training paradigm featuring a self-guided mode. This paradigm enables the rapid creation of a virtual twin agent of the child with ASD using a single photo to embody oneself, which can then guide oneself during training. We conducted an experiment with the participation of 24 children diagnosed with ASD (or ASD propensity), recording their training performance under various experimental conditions. Through expert rating, behavior coding of training sessions, and statistical analysis, our findings revealed that the use of the twin agent for self-guidance resulted in noticeable improvements in the training performance of children with ASD. These improvements were particularly evident in terms of enhancing movement quality and refining overall target-related responses. Our study holds clinical potential in the field of medical treatment and rehabilitation for children with ASD.

A Mild and Eco-friendly, One-pot Synthesis of 2-hydroxy-Narylacetamides from 2-chloro-N-arylacetamides

Abstract: A mild and eco-friendly one-pot, two-step procedure has been developed for the synthesis of 2-hydroxy-N-arylacetamides from 2-chloro-N-arylacetamides. The procedure overcomes the cleavage of the amide linkage in 2-chloroacetamides, which is usually observed under reflux conditions with the hydroxide when the nucleophilic substitution of the halide is attempted. The reactions were performed by refluxing 2-chloro-N-arylacetamides with Cu(OAc)2 and DIPEA in the ethanol medium to facilitate an acetate exchange with the halogen. Subsequently, by the addition of ethanolic KOH solution to the same reaction flask, the ester linkage was selectively cleaved in the presence of the amide, taking advantage of the difference in electrophilicity. The procedure afforded good yields of the desired products, which are valuable intermediates for several biologically active molecules, in a short reaction time with ease of isolation. The experimental conditions employed are simple and offer the possibility of scaling up to higher quantities.

Near-IR-Absorbing Bis-Donor Functionalized Aza-BODIPY Derivatives: Synthesis and Photophysical Study by Using Transient Optical Spectroscopy.

A series of near-IR absorbing 2,6-diarylated BF2-chelated aza-boron-dipyrromethenes (aza-BDPs) derivatives bearing different electron donors (benzene, naphthalene, phenanthrene, phenothiazine and carbazole) were designed and synthesized. The effect of different electron donor substitutions on the photophysical properties was studied by steady-state UV-vis absorption and fluorescence spectra, electrochemical, time-resolved nanosecond transient absorption (ns-TA) spectroscopy and theoretical computations. The UV-vis absorption spectra of AzaBDP-PTZ and AzaBDP-CAR (λabs=710 nm in toluene) showed a bathochromic absorption profile compared with the reference AzaBDP-Ph (λabs=685 nm in toluene), indicating the non-negligible electronic interaction at the ground state between donor and acceptor moieties. Moreover, the fluorescence is almost completely quenched for AzaBDP-PTZ/AzaBDP-CAR (fluorescence quantum yield, ΦF=0.2-0.7 % in toluene) as compared with the AzaBDP-Ph (ΦF=27 % in toluene). However, the apparent intersystem crossing ability of these compounds is poor, based on the singlet oxygen quantum yield (ΦΔ=0.3-1.5 %). The ns-TA spectral study showed typical Bodipy localized triplet state transient features, short-lived excited triplet state for AzaBDP-Ph (τT=53.2 μs) versus significantly long-lived triplet state for AzaBDP-CAR (τT=114 μs) was observed under deaerated experimental conditions. These triplet state lifetimes are much longer than that obtained with diiodoAzaBDP (intramolecular heavy atom effect, τT=1.5~7.2 μs). These information are useful for molecular structure design of triplet photosensitizers, for which longer triplet state lifetimes are usually desired. Theoretical computations displayed that the triplet state is mainly localized on the AzaBDP core, moreover, it was found that the HOMO/LUMO energy gap decreased after introducing donor moieties to the skeleton as compared with the reference.

Effects of pain on cortical homeostatic plasticity in humans: a systematic review.

Homeostatic plasticity (HP) is a negative feedback mechanism that prevents excessive facilitation or depression of cortical excitability (CE). Cortical HP responses in humans have been investigated by using 2 blocks of noninvasive brain stimulation with a no-stimulation block in between. A healthy HP response is characterized by reduced CE after 2 excitatory stimulation blocks and increased CE when using inhibitory stimulation. Conversely, impaired HP responses have been demonstrated in experimental and chronic pain conditions. Therefore, this systematic review aimed to provide an overview of the effect of pain on cortical HP in humans. Scopus, Embase, and PubMed were searched from inception until November 20, 2023. The included studies (1) compared experimental or clinical pain conditions with healthy controls, (2) induced HP using 2 blocks of stimulation with a no-stimulation interval, and (3) evaluated CE measures such as motor-evoked potentials. Four studies were included, consisting of 5 experiments and 146 participants, of whom 63 were patients with chronic pain and 48 were subjected to an experimental pain model. This systematic review found support for an HP impairment in pain compared with that in pain-free states, reflected by a lack of CE reduction after excitatory-excitatory HP induction over the primary motor cortex. Inhibitory-inhibitory HP induction did not produce a consistent HP response across studies, independent of pain or pain-free states. Standardization of HP induction protocols and outcome calculations is needed to ensure reproducibility and study comparison. Future HP studies may consider investigating sensory domains including nociception, which would further our understanding of abnormal HP regulation in pain conditions.

Development and Characterization of Enteric Polymer-based Solid Dispersion for Cholecalciferol Delivery

Background: The deficiency of vitamin D is a global concern affecting individuals of all age groups. Insufficient exposure to sunlight and disease conditions can lead to cholecalciferol (vitamin D3) deficiency. Objective: Cholecalciferol is a lipophilic crystalline molecule, and it is highly susceptible to degradation under environmental conditions, including light, temperature, and oxygen, and its degradation rate is high in the low pH range. Therefore, an enteric solid dispersion-based formulation was developed in the present study for the oral delivery of cholecalciferol. Method: Enteric polymer hydroxypropylmethylcellulose acetate succinate (HPMCAS)-based solid dispersion was developed and characterized by Fourier transform-infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and X-ray diffraction analysis. The effect of various concentrations of cholecalciferol formulations on the viability of Caco-2 cells was determined using an MTT assay. A dissolution and stability study of the product was also performed. Result: An amorphous form of cholecalciferol in the solid dispersion was reported. The drug content of solid dispersions was in the order of 90%. The viability assay indicated that the surfactant used in the developed solid dispersion of cholecalciferol had no cytotoxic effect on Caco-2 cells. A dissolution study on enteric solid dispersion in two-stage dissolution under a biomimetic medium indicated the pHdependent release of cholecalciferol from the HPMCAS-based solid dispersion. Moreover, the stability study showed no significant changes in the cholecalciferol content in the developed formulation under storage at experimental conditions. Conclusion: The enteric solid dispersion of cholecalciferol was developed, which exhibited compatibility with Caco-2 cells, improved dissolution, and acceptable stability profile, and represented a potential option for efficient delivery of cholecalciferol.

Determination and molecular simulation of ternary solid–liquid phase equilibrium of succinic acid + maleic acid + water from 283.15 K to 333.15 K

This study used the isothermal saturation gravimetric method to examine the solid–liquid phase equilibrium relationships composed of succinic acid + maleic acid + water spanning from 283.15 K to 333.15 K. The experimental data were utilized for the purpose of plotting the equilibrium phase diagrams of ternary systems in the studied temperature range. There were three crystalline regions in each isothermal ternary phase diagram, two saturation boundary curves, and a co-saturation point. To broaden the use of data from binary and ternary phase equilibrium measurements, Wilson and NRTL models were utilized for correlation and expectation, while relative average deviation (RAD) and root mean square deviation (RMSD) were utilized to evaluate the computational exactness. The results show that the theoretically calculated values were found to be in near agreement with the experimental values, and both models were able to obtain more precise theoretical data under different experimental conditions. In addition, molecular simulation was employed to elucidate the interaction between succinic acid, maleic acid, and water. This study provides accurate and reliable data for the separation of succinic acid and maleic acid mixture in water. These findings can be utilized to make sense of the dissolvability conduct of succinic acid and maleic acid in aqueous solution.

Industrial Production and Therapeutic Application of Botulinum Neurotoxin: The Role of C. botulinum Type A.

Botulinum neurotoxin has remarkably transitioned from a food safety hazard and biological warfare to an effective therapeutic drug. Currently, botulinum neurotoxins have seven serotypes (BoNT/A-G) in the form of protein complexes produced by Clostridium, a gram-positive and sporeforming bacteria. The conversion of toxins into useful drug substances of choice using the biotechnological process is tremendously increasing. Recent studies have shown that Botulinum neurotoxin-A (BoNT/A) has different biological activities and potencies in experimental and clinical conditions. They also indicate that the manufacturing process influences the potency and efficacy of BoNT/A drugs. Thus, this review focuses on the following criteria: detailed Fed-batch operation that includes the upstream and downstream processing of BoNT/A, the underlying mechanism behind the neurotoxic effect, and commercially available FDA-approved BoNT/A products and their therapeutic uses. Still, some research gaps exist in the mechanism for the treatment of psychiatric disorders.

An investigation on implementation of generating adversarial network-based surrogate models for prediction of turbine endwall film cooling effectiveness

Film cooling is an essential cooling technique for turbine blade, which guides coolant to cover the turbine blades surface by arranging discrete film holes on it. For the newly designed cooling units, the process of predicting film cooling effectiveness is really complex and time-consuming. For the purpose of accelerating the design procedure, the U-Net which is a very popular algorithm in the field of deep learning was improved with the basic layer structure, then it was adopted as the proxy function for the film cooling effectiveness prediction. The basic samples were generated by Latin hypercube sampling method and calculated by commercial software. The results were verified by experiment in a linear cascade. The training and testing samples were calculated at experimental conditions (inlet Mach number values 0.12). The results showed that comparing with the basic U-Net network, the novel U-Net network has a great better accuracy on the prediction of contour results. Both of the improved U-Net networks had higher prediction accuracy than original models. The correlation index reached more than 99.5% and the first order error was lower than 0.3%. The number of basic neural layers is not positively correlated with the network prediction accuracy which exists an optimal ratio. The experimental verification shows that the generating adversarial network prediction results are consistent with the experimental results. The final prediction results showed that the U-Net model can be used as a surrogate model and meets the requirements for accuracy of film cooling effectiveness prediction.

Exploration of reference genes for the development of a diagnostic kit on vascular aging in human saliva.

Identifying reliable biomarkers in saliva can be a promising approach to developing a rapid diagnostic kit for detecting vascular aging. This study investigated the most suitable reference gene for polymerase chain reaction (PCR) in saliva that is not affected by vascular aging variables. Whole saliva samples were collected to assess the expression of reference genes: actin beta (ACTB), 18S ribosomal RNA (18S rRNA), beta-2-microglobulin, and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). The most abundantly expressed gene was 18S rRNA, and the least expressed gene was GAPDH. Four genes were ranked according to their relative stability, as determined by mathematical algorithms, indicating that ACTB and 18S rRNA were stably expressed as reference genes. 18S rRNA was identified as the most promising reference gene for detecting systemic diseases using saliva from patients with vascular aging in these limited experimental conditions.

Exact ASP Counting with Compact Encodings

Answer Set Programming (ASP) has emerged as a promising paradigm in knowledge representation and automated reason- ing owing to its ability to model hard combinatorial problems from diverse domains in a natural way. Building on advances in propositional SAT solving, the past two decades have wit- nessed the emergence of well-engineered systems for solv- ing the answer set satisfiability problem, i.e., finding mod- els or answer sets for a given answer set program. In re- cent years, there has been growing interest in problems be- yond satisfiability, such as model counting, in the context of ASP. Akin to the early days of propositional model count- ing, state-of-the-art exact answer set counters do not scale well beyond small instances. Exact ASP counters struggle with handling larger input formulas. The primary contribu- tion of this paper is a new ASP counting framework, called sharpASP, which counts answer sets avoiding larger input formulas. This relies on an alternative way of defining answer sets that allows lifting of key techniques developed in the con- text of propositional model counting. Our extensive empirical analysis over 1470 benchmarks demonstrates significant per- formance gain over current state-of-the-art exact answer set counters. Specifically, by using sharpASP, we were able to solve 1062 benchmarks with PAR2 score of 3082 whereas using prior state-of-the-art, we could only solve 895 bench- marks with PAR2 score of 4205, all other experimental con- ditions being the same.

A numerical compass for experiment design in chemical kinetics and molecular property estimation

Kinetic process models are widely applied in science and engineering, including atmospheric, physiological and technical chemistry, reactor design, or process optimization. These models rely on numerous kinetic parameters such as reaction rate, diffusion or partitioning coefficients. Determining these properties by experiments can be challenging, especially for multiphase systems, and researchers often face the task of intuitively selecting experimental conditions to obtain insightful results. We developed a numerical compass (NC) method that integrates computational models, global optimization, ensemble methods, and machine learning to identify experimental conditions with the greatest potential to constrain model parameters. The approach is based on the quantification of model output variance in an ensemble of solutions that agree with experimental data. The utility of the NC method is demonstrated for the parameters of a multi-layer model describing the heterogeneous ozonolysis of oleic acid aerosols. We show how neural network surrogate models of the multiphase chemical reaction system can be used to accelerate the application of the NC for a comprehensive mapping and analysis of experimental conditions. The NC can also be applied for uncertainty quantification of quantitative structure–activity relationship (QSAR) models. We show that the uncertainty calculated for molecules that are used to extend training data correlates with the reduction of QSAR model error. The code is openly available as the Julia package KineticCompass.Graphical

Quantifying noise effects in optical measures of excited state transport.

Time-resolved microscopy is a widely used approach for imaging and quantifying charge and energy transport in functional materials. While it is generally recognized that resolving small diffusion lengths is limited by measurement noise, the impacts of noise have not been systematically assessed or quantified. This article reports modeling efforts to elucidate the impact of noise on optical probes of transport. Excited state population distributions, modeled as Gaussians with additive white noise typical of experimental conditions, are subject to decay and diffusive evolution. Using a conventional composite least-squares fitting algorithm, the resulting diffusion constant estimates are compared with the model input parameter. The results show that heteroscedasticity (i.e., time-varying noise levels), insufficient spatial and/or temporal resolution, and small diffusion lengths relative to the magnitude of noise lead to a surprising degree of imprecision under moderate experimental parameters. Moreover, the compounding influence of low initial contrast and small diffusion length leads to systematic overestimation of diffusion coefficients. Each of these issues is quantitatively analyzed herein, and experimental approaches to mitigate them are proposed. General guidelines for experimentalists to rapidly assess measurement precision are provided, as is an open-source tool for customizable evaluation of noise effects on time-resolved microscopy transport measurements.

Comparative effectiveness of carbon nanoparticles and biochar in alleviating copper stress in corn (Zea mays L.)

The application of carbon nanoparticles (CNPs) and biochar in agriculture for improving plant health and soil quality and alleviating metal stress offers alternative approaches to meet the ever-increasing demand for food. However, poor understanding of their roles in improving crop production under Cu stress represents a significant obstacle to their wide application in agriculture. To clarify how CNPs and biochar affect corn (Zea mays L.) seed germination, seedling growth, plant health, and nutrient uptake under different Cu stress levels, soil-less Petri-dish and greenhouse soil-based bioassays were conducted. The results revealed that CNPs and biochar stimulated corn seed germination and seedling growth. Besides, they were effective in immobilizing Cu2+ sorption in sandy soil and alleviating Cu stress for plant growth, as shown by the increased plant height and dry biomass. The plant nutrient uptake efficiency (NUE) was significantly increased by CNPs, with a maximum increase of 63.1% for N and 63.3% for K at the highest Cu2+ stress level (400 mg Cu2+ L−1). In contrast, non-significant effects on NUE were observed with biochar treatments regardless of Cu stress levels. Interestingly, CNPs significantly increased plant uptake of Cu in the Petri dish test, while biochar inhibited plant uptake of Cu under both experimental conditions. Principle component analysis (PCA) and Pearson correlation analysis indicated that CNPs mitigated Cu stress mainly by elevating antioxidant enzyme activities, enhancing plant photochemical efficiency, and increasing plant uptake of N and K, while biochar was more likely to reduce bioavailability and uptake of Cu in the plant. These findings have great implications for the application of CNPs and biochar as plant growth stimulators and de-toxicity agents in agriculture.

Experimental conditions for efficient retention of vascular endothelial cells on channel wall using lipid bubbles and acoustic interference

In order to fabricate multi-layered artificial blood vessels, bubble-surrounded cells were retained on the wall in a flow channel using the phase sweeping of interferential acoustic field. First, spatial distribution of acoustic intensity was defined to evaluate retention performance. Comparing between various acoustic fields, we found appropriate acoustic intensity for retention of the cells. Next, phase sweeping of the acoustic field was conducted to increase the retained area of the cells by varying sweep velocity, sweep direction, and the amplitudes of sound pressure. As the result, an interferential acoustic field with a balanced sound pressures of 200 kPa-pp at a sweep velocity of 100 mm s−1, which was 10 times higher than the flow, and the sweep direction against the flow, obtained a retained area 1.6 times larger than that without sweeping. We will apply the conditions based on the results for the future 3D fabrication of artificial blood vessels.

Uranium accumulation in environmentally relevant microplastics and agricultural soil at acidic and circumneutral pH

The co-occurrence of microplastics (MPs) with potentially toxic metals in the environment stresses the need to address their physicochemical interactions and the potential ecological and human health implications. Here, we investigated the reaction of aqueous U with agricultural soil and high-density polyethylene (HDPE) through the integration of batch experiments, microscopy, and spectroscopy. The aqueous initial concentration of U (100 μM) decreased between 98.6 and 99.2 % at pH 5 and between 86.2 and 98.9 % at pH 7.5 following the first half hour of reaction with 10 g of soil. In similar experimental conditions but with added HDPE, aqueous U decreased between 98.6 and 99.7 % at pH 5 and between 76.1 and 95.2 % at pH 7.5, suggesting that HDPE modified the accumulation of U in soil as a function of pH. Uranium-bearing precipitates on the cracked surface of HDPE were identified by SEM/EDS after two weeks of agitation in water at both pH 5 and 7.5. Accumulation of U on the near-surface region of reacted HDPE was confirmed by XPS. Our findings suggest that the precipitation of U was facilitated by the weathering of the surface of HDPE. These results provide insights about surface-mediated reactions of aqueous metals with MPs, contributing relevant information about the mobility of metals and MPs at co-contaminated agricultural sites.