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J. Zhai, J. Zhai, J. Zhai et al.

<p>Aerosol acidity plays a crucial role in multiphase atmospheric chemistry, influencing aerosol composition, gas-particle partitioning, and the oxidative capacity of atmosphere. However, the mechanisms governing aerosol acidity in coastal areas under extreme weather remains challenging due to the complexity of atmospheric transport. Here, we investigate aerosol pH in Shenzhen, a coastal megacity in China, by integrating field observations with multiphase buffer theory and ISORROPIA simulations. Our observations captured both a typhoon episode and typical non-typhoon periods with two contrasting regimes: during non-typhoon periods, aerosols were consistently buffered by the <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msubsup><mi mathvariant="normal">NH</mi><mn mathvariant="normal">4</mn><mo>+</mo></msubsup><mo>/</mo><msub><mi mathvariant="normal">NH</mi><mn mathvariant="normal">3</mn></msub></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="50pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="c15d8a97c09fdbd515e474ed6a4d529e"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-26-623-2026-ie00001.svg" width="50pt" height="15pt" src="acp-26-623-2026-ie00001.png"/></svg:svg></span></span> pair, with relative humidity serving as the primary driver of pH variability, enabling reliable predictions using multiphase buffer theory. In contrast, during a typhoon episode, nonvolatile cations derived from sea salts emerged as the dominant drivers, violating the charge balance for <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msubsup><mi mathvariant="normal">NH</mi><mn mathvariant="normal">4</mn><mo>+</mo></msubsup><mo>/</mo><msub><mi mathvariant="normal">NH</mi><mn mathvariant="normal">3</mn></msub></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="50pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="b2a2415879fe27eec0a40dd7b0707630"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-26-623-2026-ie00002.svg" width="50pt" height="15pt" src="acp-26-623-2026-ie00002.png"/></svg:svg></span></span> buffering and leading to poor performance of buffer theory. ISORROPIA simulations under the assumption of constant aerosol water content reproduced the observed pH more reliably, highlighting a compositional rather than meteorological control. Our results provide direct field-based evidence for regime shifts in aerosol acidity regulation in coastal regions and underscore the need for chemical transport models to account for composition-meteorology interactions to improve acidity predictions under extreme weather events.</p>

Bruno da S. Macêdo, Larissa Lima, Douglas Lima Fonseca et al.

Dissolved oxygen (DO) is widely recognized as a fundamental parameter in assessing water quality, given its critical role in supporting aquatic ecosystems. Accurate estimation of DO levels is crucial for effective management of riverine environments, especially in anthropogenically stressed regions. In this study, a hybrid machine learning (ML) framework is introduced to predict DO concentrations, where optimization is performed through Genetic Algorithm Search with Cross-Validation (GASearchCV). The methodology was applied to a dataset collected from the Sitnica River in Kosovo, comprising more than 18,000 observations of temperature, conductivity, pH, and dissolved oxygen. The ML models Elastic Net (EN), Support Vector Regression (SVR), and Light Gradient Boosting Machine (LGBM) were fine-tuned using cross-validation and assessed using five performance metrics: coefficient of determination (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi mathvariant="normal">R</mi><mn>2</mn></msup></semantics></math></inline-formula>), root mean square error (RMSE), mean absolute error (MAE), mean absolute relative error MARE, and mean square error (MSE). Among them, the LGBM model yielded the best predictive results, achieving an <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi mathvariant="normal">R</mi><mn>2</mn></msup></semantics></math></inline-formula> of 0.944 and RMSE of 8.430 mg/L on average. A Monte Carlo Simulation-based uncertainty analysis further confirmed the model’s robustness, enabling comparison of the trade-off between uncertainty and predictive precision. Comparison with recent studies confirms the proposed framework’s competitive performance, demonstrating the effectiveness of automated tuning and ensemble learning in achieving reliable and real-time water quality forecasting. The methodology offers a scalable and reliable solution for advancing data-driven water quality forecasting, with direct applicability to real-time environmental monitoring and sustainable resource management.

N. Bednaršek, H. van de Mortel, G. Pelletier et al.

<p>Ocean alkalinity enhancement (OAE), one of the marine carbon dioxide removal strategies, is gaining recognition in its ability to mitigate climate change and ocean acidification (OA). OAE is based on adding alkalinity to open-ocean and coastal marine systems through a variety of different approaches, which raises carbonate chemistry parameters (such as pH, total alkalinity, aragonite saturation state) and enhances the uptake of carbon dioxide (CO<span class="inline-formula">₂</span>) from the atmosphere. There are large uncertainties in both short- and long-term outcomes related to potential environmental impacts, which would ultimately have an influence on the social license and success of OAE as a climate strategy. This paper represents a synthesis effort, leveraging on the OA studies and published data, observed patterns, and generalizable responses. Our assessment framework was developed to predict the sensitivity of marine calcifiers to OAE by using data originating from OA studies. The synthesis was done using raw experimental OA data based on 68 collected studies, covering 84 unique species and capturing the responses of 11 biological groups (calcifying algae, corals, dinoflagellates, mollusks, gastropods, pteropods, coccolithophores, annelids, crustacean, echinoderms, and foraminifera), using regression analyses to predict biological responses to NaOH or Na<span class="inline-formula">₂</span>CO<span class="inline-formula">₃</span> addition and their respective thresholds. Predicted responses were categorized into six different categories (linear positive and negative, threshold positive and negative, parabolic and neutral) to delineate responses per species. The results show that 34.4 % of responses are predicted to be positive (<span class="inline-formula"><i>N</i>=33</span>), 26.0 % negative (<span class="inline-formula"><i>N</i>=25</span>), and 39.2 % (<span class="inline-formula"><i>N</i>=38</span>) neutral upon alkalinity addition. For the negatively impacted species, biological thresholds, which were based on 50 % reduction of calcification rate, were in the range of 50 to 500 <span class="inline-formula">µ</span>mol kg<span class="inline-formula">⁻¹</span> NaOH addition. Thus, we emphasize the importance of including much lower additions of alkalinity in experimental trials to realistically evaluate in situ biological responses. However, it is important to note our results do not consider equilibration with the atmosphere and are thus only applicable to short-term and near-field application. The primary goal of the research was to provide an assessment of biological rates and thresholds predicted under NaOH <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M9" display="inline" overflow="scroll" dspmath="mathml"><mo>/</mo></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="880d1b22cfae9b4167ff115d05c6894c"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-473-2025-ie00001.svg" width="8pt" height="14pt" src="bg-22-473-2025-ie00001.png"/></svg:svg></span></span> Na<span class="inline-formula">₂</span>CO<span class="inline-formula">₃</span> addition that can serve as a tool for delineating OAE risks. This will help guide and prioritize future OAE biological research and regional monitoring efforts and will also aid in communicating risks to stakeholders. This<span id="page474"/> is important given the fact that at least some of the current OAE approaches do not always assure safe biological space. With 60 % of responses being non-neutral, a precautionary approach for OAE implementation is warranted, identifying the conditions where potential negative ecological outcomes could happen, which is key for scaling up and avoiding ecological risks.</p>

P. Köhler, S. Mulitza

<p>Laboratory experiments showed that the isotopic fractionation of <span class="inline-formula"><i>δ</i>¹³</span>C and of <span class="inline-formula"><i>δ</i>¹⁸</span>O during calcite formation of planktic foraminifera are species-specific functions of ambient CO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">3</mn><mrow><mn mathvariant="normal">2</mn><mo>-</mo></mrow></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="13pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="490d7ecf09fa5682b13318d48526c23f"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cp-20-991-2024-ie00001.svg" width="13pt" height="17pt" src="cp-20-991-2024-ie00001.png"/></svg:svg></span></span> concentration. This effect became known as the carbonate ion effect (CIE), whose role for the interpretation of marine sediment data will be investigated here in an in-depth analysis of the <span class="inline-formula">¹³</span>C cycle. For this investigation, we constructed new 160 kyr long mono-specific stacks of changes in both <span class="inline-formula"><i>δ</i>¹³</span>C and <span class="inline-formula"><i>δ</i>¹⁸</span>O from either the planktic foraminifera <i>Globigerinoides ruber</i> (rub) or <i>Trilobatus sacculifer</i> (sac) from 112 and 40 marine records, respectively, from the wider tropics (latitudes below 38°). Both mono-specific time series <span class="inline-formula">Δ(<i>δ</i>¹³C_rub)</span> and <span class="inline-formula">Δ(<i>δ</i>¹³C_sac)</span> are very similar to each other, and a linear regression through a scatter plot of both data sets has a slope of <span class="inline-formula">∼</span> 0.99 – although the laboratory-based CIE for both species differs by a factor of nearly 2, implying that they should record distinctly different changes in <span class="inline-formula"><i>δ</i>¹³C</span>, if we accept that the carbonate ion concentration changes on glacial–interglacial timescales. For a deeper understanding of the <span class="inline-formula">¹³</span>C cycle, we use the Solid Earth version of the Box model of the Isotopic Carbon cYCLE (BICYLE-SE) to calculate how surface-ocean CO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M13" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">3</mn><mrow><mn mathvariant="normal">2</mn><mo>-</mo></mrow></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="13pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="96f0b496066d50de98e398addfd99620"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cp-20-991-2024-ie00002.svg" width="13pt" height="17pt" src="cp-20-991-2024-ie00002.png"/></svg:svg></span></span> should have varied over time in order to be able to calculate the potential offsets which would by caused by the CIE quantified in culture experiments. Our simulations are forced with atmospheric reconstructions of CO<span class="inline-formula">₂</span> and <span class="inline-formula"><i>δ</i>¹³</span>CO<span class="inline-formula">₂</span> derived from ice cores to obtain a carbon cycle which should at least at the surface ocean be as close as possible to expected conditions and which in the deep ocean largely agrees with the carbon isotope ratio of dissolved inorganic carbon (DIC), <span class="inline-formula"><i>δ</i>¹³C_DIC</span>, as reconstructed from benthic foraminifera. We find that both <span class="inline-formula">Δ(<i>δ</i>¹³C_rub)</span> and <span class="inline-formula">Δ(<i>δ</i>¹³C_sac)</span> agree better with changes in simulated <span class="inline-formula"><i>δ</i>¹³C_DIC</span> when ignoring the CIE than those time series which were corrected for the CIE. The combination of data- and model-based evidence for the lack of a role for the CIE in <span class="inline-formula">Δ(<i>δ</i>¹³C_rub)</span> and <span class="inline-formula">Δ(<i>δ</i>¹³C_sac)</span> suggests that the CIE as measured in laboratory experiments is not directly transferable to the interpretation of marine sediment records. The much smaller CIE-to-glacial–interglacial-signal ratio in foraminifera <span class="inline-formula"><i>δ</i>¹⁸</span>O, when compared to <span class="inline-formula"><i>δ</i>¹³</span>C, prevents us from drawing robust conclusions on the role of the CIE in <span class="inline-formula"><i>δ</i>¹⁸</span>O as recorded in the hard shells of both species. However, theories propose that the CIE in both <span class="inline-formula"><i>δ</i>¹³</span>C and <span class="inline-formula"><i>δ</i>¹⁸</span>O depends on the pH in the surrounding water, suggesting that the CIE should be detectable in neither or both of the isotopes. Whether this lack of role of the CIE in the interpretation of planktic paleo-data is a general feature or is restricted to the two species investigated here needs to be checked with further data from other planktic foraminiferal species.</p>

António G. Costa, Gonçalo Lopes, João F. G. Rodrigues et al.

New iron and cobalt bis(dithiolene) complexes [M(3cbdt)₂] (3cbdt = 3-cyanobenzene-1,2-dithiolate) were prepared as tetraphenylphosphonium (Ph₄P⁺) salts for Fe in the monoanionic state and for Co in both the dianionic and monoanionic states: (Ph₄P)₂[Fe(III)(3cbdt)₂]₂ (<b>1</b>); (Ph₄P)₂[Co(III)(3cbdt)₂]₂ (<b>2</b>); (Ph₄P)₂[Co(II)(3cbdt)₂] (<b>3</b>). These compounds were characterized by single-crystal X-ray diffraction, cyclic voltammetry, EPR, and static magnetic susceptibility. Their properties are discussed in comparison with the corresponding complexes based on the isomer ligand 4-cyanobenzene-1,2-dithiolate (4cbdt) and 4,5-cyanobenzene-1,2-dithiolate (dcbdt), previously described by us. The Fe(III) and the Co(III) compounds (<b>1</b> and <b>2</b>) are isostructural, crystallizing in the triclinic <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>P</mi><mover accent="false"><mrow><mn>1</mn></mrow><mo>¯</mo></mover></mrow></semantics></math></inline-formula> space group, with cis [M(III)(3cbdt)₂] complexes dimerized in a trans fashion, and the transition metal (M = Fe, Co) has a distorted 4+1 square pyramidal coordination geometry. The Co(II) compound (<b>3</b>) crystallizes in the triclinic <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>P</mi><mover accent="false"><mrow><mn>1</mn></mrow><mo>¯</mo></mover></mrow></semantics></math></inline-formula> space group, with the unit cell containing one cis and three trans inequivalent [Co(II)(3cbdt)₂] complexes with the transition metal (Co) and having a square planar coordination geometry. The Fe(III) complex (<b>1</b>) is EPR-silent, and the static magnetic susceptibility shows a temperature dependence typical of dimers of antiferromagnetically coupled <i>S</i> = 3/2 spins with −<i>J</i>/<i>k_B</i> = 233.6 K and <i>g</i> = 1.8. Static magnetic susceptibility measurements of compound (<b>3</b>) show that this Co(II) complex is paramagnetic, corresponding to an <i>S</i> = ½ state with <i>g</i> = 2, in agreement with EPR spectra showing in solid state a hyperfine structure typical of the <i>I(</i>⁵⁹Co) = 7/2. Static susceptibility measurements of Co(III) complex (<b>2</b>) showed an increase in the paramagnetic susceptibility upon warming above 100 K, which is consistent with strong AFM coupling between dimerized <i>S</i> = 1 units with a constant −<i>J</i>/<i>k_B</i> ~1286 K.

F. M. Reda, A. S. Salah, Y. A. Attia et al.

<p>Supplements derived from plants are utilized to maintain and promote the growth efficiency of animals. The use of black pepper oil (BPO) has recently generated significant scientific interest, primarily because of its potential beneficial effects on both humans and animals. The goal of the current study was to determine how dietary BPO supplementation affected growth performance, characteristics of growing quails' immunity, antioxidant status, and carcass yield. A total of 240 growing quails (1 week old) were divided into five equal groups, each with 36 birds (four replicates of 12 each). A basal diet containing no BPO (0 <span class="inline-formula">g kg⁻¹</span>) was given to the first group, and the second, third, and fourth groups were given a diet that was supplemented with BPO (0.4, 0.8, 1.2, and 1.6 <span class="inline-formula">g kg⁻¹</span>, respectively). In comparison to a control group, quails' diets that were supplemented with 0.8 <span class="inline-formula">g BPO kg⁻¹</span> showed improvements in final live body weight, body weight gain, and feed conversion ratio of 10.68 %, 12.6 %, and 18.2 %, respectively. During the whole study period (1 to 5 weeks), quails fed diets with 0.8 <span class="inline-formula">g BPO</span> consumed less feed than the other groups and control. Due to BPO treatment, there were no statistically significant changes in any of the carcass parameters. BPO-supplemented groups had significantly elevated plasma levels of albumin and globulin than control groups (<span class="inline-formula"><i>P</i></span> <span class="inline-formula">&lt;</span> 0.05), but the <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M7" display="inline" overflow="scroll" dspmath="mathml"><mrow><mtext>albumin</mtext><mo>/</mo><mtext>globulin</mtext></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="84pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="f5ba174d4ce2e68b7e20af470cf093b1"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="aab-67-445-2024-ie00001.svg" width="84pt" height="14pt" src="aab-67-445-2024-ie00001.png"/></svg:svg></span></span> ratio was reported to be significantly decreased (<span class="inline-formula"><i>P</i></span> <span class="inline-formula">&lt;</span> 0.05) in birds supplemented with diets containing BPO compared to the control group. When compared to the control, the liver enzyme activity (aspartate transaminase (AST) and alanine transaminase (ALT)) in blood plasma was reported to be significantly increased in the quails given 0.4 and 0.8 <span class="inline-formula">g BPO kg⁻¹</span>. Glutathione and catalase activities were significantly higher in the group given diets supplemented with BPO (1.2 <span class="inline-formula">g kg⁻¹</span>) than they were in the control group. In comparison to the control, the supplementation of BPO in the diets of quail significantly enhanced (<span class="inline-formula"><i>P</i></span> <span class="inline-formula">&lt;</span> 0.05) the lipid profile in the plasma, moreover decreasing the caecal content pH (<span class="inline-formula"><i>P</i></span> <span class="inline-formula">&lt;</span> 0.05). In comparison to the control, the populations of lactobacilli, coliform, <i>Salmonella</i> spp., and <i>Escherichia coli</i> in the caecum significantly decreased in the BPO-supplemented groups (<span class="inline-formula"><i>P</i></span> <span class="inline-formula">&lt;</span> 0.05). In conclusion, dietary BPO supplementation in Japanese quails' diet can boost growth performance and antioxidant indices, enhance lipid profile and carcass traits, and reduce intestinal infections.</p>

Fedor Ozhegov, Mikhail Skopenkov, Alexey Ustinov

Feynman gave a famous elementary introduction to quantum theory by discussing the thin-film reflection of light. We make his discussion mathematically rigorous, keeping it elementary, using his other idea. The resulting model leads to accurate quantitative results and allows us to derive a well-known formula from optics. In the process, we get acquainted with mathematical tools such as Smirnov's fermionic observables, transfer matrices, and spectral radii. Quantum walks and the six-vertex model arise as the next step in this direction.

Yerko Escalona, Drazen Petrov, Edgar Galicia-Andrés et al.

Soil organic matter (SOM) is composed of a complex and heterogeneous mixture of organic compounds, which poses a challenge in understanding it on an atomistic level. Based on the progress of molecular dynamics simulations and our efforts to create molecular systems that resemble SOM, in this work, we expanded our knowledge of SOM through the use of humic substances (HSs). Specifically, we studied the standardized samples of HS of the International Humic Substances Society (IHSS). This society provided the elemental and organic composition used as input parameters for our Vienna Soil Organic Matter Modeler 2 (VSOMM2). We modeled and simulated different HS samples from various sources, including soil, peat, leonardite, and blackwater river. In order to compare between different HS, we reduced the organic composition information to two principal components, which are associated principally with the amount of carboxyl and aromatic groups in the HS, denominated as PC<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>acid</mi></msub></semantics></math></inline-formula> and PC<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>arom</mi></msub></semantics></math></inline-formula>, respectively. We performed a plethora of analyses to characterize the structure and dynamics of the systems, including the total potential energy, density, diffusion, preferential solvation, hydrogen bonds, and salt bridges. In general terms, at the water content value of 0.2, we observed that most properties depend on the carboxyl group protonation state. The Coulombic interactions from this ionic specie and the interaction with cations determine the overall behavior of the studied systems. Furthermore, the type of cations and the pH influence those properties. This study exemplifies the importance of molecular dynamics to explain macroscopic properties from the structure and dynamics of the molecules modeled, such as the interaction network, i.e., hydrogen bonds or salt bridges of molecules presented in the system and their mobility.

Pablo Otálora, José Luis Guzmán, Manuel Berenguel et al.

The industrial production of microalgae is a process as sustainable as it is interesting in terms of its diverse applications, especially for wastewater treatment. Its optimization requires an exhaustive knowledge of the system, which is commonly achieved through models that describe its dynamics. Although not widely used in this field, artificial neural networks are presented as an appropriate technique to develop this type of model, having the ability to adapt to complex and nonlinear problems solely from the process data. In this work, neural network models have been developed to characterize the pH dynamics in two different raceway reactors, one with freshwater and the other with wastewater. The models are able to predict pH profiles with a prediction horizon of up to eleven hours and only using available measurable process data, such as medimum level, CO<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula> injection, and solar radiation. The results demonstrate the potential of artificial neural networks in the modeling of continuous dynamic systems in the field of industry, obtaining accurate, fast-running models that can adapt to different circumstances. Moreover, these models open the field to the design of data-driven model-based control algorithms to account for the nonlinear dynamics of this biological system.

Tom Van de Steene, Emmeric Tanghe, Luc Martens et al.

This study investigates wireless power transfer for deep in-body receivers, determining the optimal frequency, power budget, and design for the transmitter and receiver. In particular, the focus is on small, in-body receivers at large depths up to 20 cm for obese patients. This enables long-term monitoring of the gastrointestinal tract for all body types. Numerical simulations are used to investigate power transfer and losses as a function of frequency and to find the optimal design at the selected frequency for an obese body model. From all ISM-frequencies in the investigated range (1 kHz–10 GHz), the value of 13.56 MHz yields the best performance. This optimum corresponds to the transition from dominant copper losses in conductors to dominant losses in conductive tissue. At this frequency, a transmitting and receiving coil are designed consisting of 12 and 23 windings, respectively. With a power transfer efficiency of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>2.70</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>5</mn></mrow></msup></mrow></semantics></math></inline-formula>, 18 µW can be received for an input power of 0.68 W while still satisfying exposure guidelines. The power transfer is validated by measurements. For the first time, efficiency values and the power budget are reported for WPT through 20 cm of tissue to mm sized receivers. Compared to WPT at higher frequencies, as commonly used for small receivers, the proposed system is more suitable for WPT to large depths in-body and comes with the advantage that no focusing is required, which can accommodate multiple receivers and uncertainty about receiver location more easily. The received power allows long-term sensing in the gastrointestinal tract by, e.g., temperature, pressure, and pH sensors, motility sensing, or even gastric stimulation.

Laura Shou

We extend the approach from [arXiv:2110.15301] to prove windowed spectral projection estimates and a generalized Weyl law for the (Weyl) quantized baker's map on the torus. The spectral window is allowed to shrink in the semiclassical (large dimension) limit. As a consequence, we obtain a strengthening of the quantum ergodic theorem from [arXiv:math-ph/0412058] to hold in shrinking spectral windows, a Weyl law on uniform spreading of eigenvalues, and statistics of random quasimodes. Using similar techniques, we also investigate random eigenbases of a different (non-Weyl) quantization, the Walsh-quantized baker's map, which has high degeneracies in its spectrum. For such random eigenbases, we prove that Gaussian eigenstate statistics and QUE hold with high probability in the semiclassical limit.

Massimo Moscolari, Gianluca Panati

We generalize Prodan's construction of radially localized generalized Wannier bases [E. Prodan, On the generalized Wannier functions. J. Math. Phys. 56(11), 113511 (2015)] to gapped quantum systems without time-reversal symmetry, including in particular magnetic Schrödinger operators, and we prove some basic properties of such bases. We investigate whether this notion might be relevant to topological transport by considering the explicitly solvable case of the Landau operator.

Andras Suto

We prove two equilibrium properties of a system of interacting atoms in three or higher dimensional continuous space. (i) If the particles interact via pair potentials of a nonnegative Fourier transform, their self-organization into infinite permutation cycles is simultaneous with off-diagonal long-range order. If the cycle lengths tend to infinity not slower than the square of the linear extension of the system, there is also Bose-Einstein condensation. (ii) If the pair potential is also nonnegative, cycles composed of a nonzero fraction of the total number of particles do appear if the density exceeds a temperature-dependent threshold value. The two together constitute the proof that in such a system Bose-Einstein condensation takes place at high enough densities.

Luis Chávez, Lucien Veleva, Gerardo Sánchez et al.

The initial stages of AM60-AlN nanocomposite and AM60 corrosion behaviors were compared over 30 days of exposure to solution (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>NaCl</mi></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>Na</mi></mrow><mn>2</mn></msub><msub><mrow><mi>SO</mi></mrow><mn>4</mn></msub></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>NaHCO</mi></mrow><mn>3</mn></msub></mrow></semantics></math></inline-formula>), simulating the marine-coastal environment (SME). The incorporation of AlN nanoparticles (1.0 wt.%) in the AM60 alloy matrix favored the lower roughness of the AM60-AlN, associated with the grain refinement in the matrix. During the immersion of the alloys, pH of the SME solution shifted to alkaline values >9, and therefore, the solubility of AlN aluminum hydroxide phases were raised, followed by a slightly higher release of Mg-ions and corrosion rate increase. The chloride ions attributed to the unstability of the Al-Mn phase and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Al</mi><msub><mrow><mrow><mo>(</mo><mrow><mi>OH</mi></mrow><mo>)</mo></mrow></mrow><mn>3</mn></msub></mrow></semantics></math></inline-formula> corrosion product was formed in a low content. The composite AM60-AlN presented lower value of the electrochemical noise resistance <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mrow><mo>(</mo><mrow><msub><mi mathvariant="normal">R</mi><mi mathvariant="normal">n</mi></msub></mrow><mo>)</mo></mrow></mrow></semantics></math></inline-formula>, suggesting that the corrosion process occurs with less difficulty. The localized corrosion near the Al-Mn cathodes seems to be stronger on the composite surface, in area and depth of penetration. The corrosion current fluctuations suggested that the corrosion is a weakly persistent process, dominated by the fractional Gaussian noise (fGn).

Tatyana V. Volkova, Olga R. Simonova, German L. Perlovich

The complex formation of antiandrogen bicalutamide (BCL) with methylated (Me-β-CD) and acetylated (Ac-β-CD) β-cyclodextrins was investigated in buffer solution pH 6.8. A two-fold strongly binding of BCL to Ac-β-CD as compared to Me-β-CD was revealed. The solid dispersion of BCL with Ac-β-CD was prepared by the mechanical grinding procedure to obtain the complex in the solid state. The BCL/Ac-β-CD complex was characterized by DSC, XPRD, FTIR, and SEM techniques. The effect of Ac-β-CD in the BCL solid dispersions on the non-sink dissolution/permeation simultaneous processes was disclosed using the side-by-side diffusion cell with the help of the cellulose membrane. The elevated dissolution of the ground complex, as compared to the raw drug as well as the simple physical mixture, accompanied by the supersaturation was revealed. Two biopolymers—polyvinylpyrrolidone (PVP, M_n = 58,000) and hydroxypropylmethylcellulose (HPMC, M_n ~ 10,000)—were examined as the precipitation inhibitors and were shown to be useful in prolonging the supersaturation state. The BCL/Ac-β-CD complex has the fastest dissolution rate in the presence of HPMC. The maximal concentration of the complex was achieved at a time of 20, 30, and 90 min in the pure buffer, with PVP and with HPMC, respectively. The effectiveness of the BCL dissolution (release) processes (illustrated by the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>A</mi><mi>U</mi><msub><mi>C</mi><mrow><mi>C</mi><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo></mrow></msub></mrow></semantics></math></inline-formula> parameter) was estimated to be 7.8-, 5.8-, 3.0-, and 1.8-fold higher for BCL/Ac-β-CD (HPMC), BCL/Ac-β-CD (PVP), BCL/Ac-β-CD (buffer), and the BCL/Ac-β-CD physical mixture, respectively, as compared to the BCL_raw sample. The excipient gain factor (EGF), calculated for the dissolution of the BCL complex, was shown to be 2.6 in the presence of HPMC, which is 1.3-fold greater as compared to PVP. From the experimental dissolution results, it can be concluded that the formation of BCL ground complex with Ac-β-CD enhances the dissolution rate of the compound. The permeation was also shown to be advantageous in the presence of the polymers, which was demonstrated by the elevated fluxes of BCL through the membrane. The comparison of the dissolution/permeation processes was illustrated and discussed. The conclusion was made that the presence of HPMC as a stabilizer of the supersaturation state is promising and seems to be a useful tool for the optimization of BCL pharmaceutical formulations manufacturing.

Ngoc Minh Le, Marcel Mandel, Lutz Krüger et al.

The intermetallic alloy FeAl40 was plasma nitrided at 575 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mo>∘</mo></msup></semantics></math></inline-formula>C for 4 h while varying the N<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>–H<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula> gas mixture with nitrogen contents f<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mi mathvariant="normal">N</mi><mn>2</mn></mrow></msub></semantics></math></inline-formula> between 0.1 and 0.9. The effect of the gas mixture on the resulting structure of the nitrided FeAl40 and the associated electrochemical corrosion behaviour in a 0.25 M H<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>SO<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>4</mn></msub></semantics></math></inline-formula> (pH = 0.3) electrolyte were investigated using different complementary analytical methods such as scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray spectroscopy, electron probe microanalysis (EPMA), electrochemical polarisation and electrochemical impedance spectroscopy. Nitriding significantly changed the corrosion mechanism of FeAl40 alloys in acidic environments, ranging from consistently high material loss in untreated base material to strongly inhibited material loss. This phenomenon was the result of a corrosion product layer formed on nitrided FeAl40 during the corrosion process. Therefore, plasma nitriding reduced the corrosion rate to about 5–7 mm/year compared with 22 mm/year of the untreated FeAl40 base material. A high nitrogen content in the N<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>–H<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula> plasma of more than f<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mi mathvariant="normal">N</mi><mn>2</mn></mrow></msub></semantics></math></inline-formula> = 0.3 ensured the formation of protective nitrided layers on FeAl40. In addition, an approach to explaining the effect of the nitrided layer on FeAl materials was presented on the basis of thermodynamic considerations.

Yanqing Wen, Baoliang Liu, Haiyan Shi et al.

In this paper, we investigate a wear and mixed shock model in which the system can fail due to internal aging or external shocks. The lifetime of the system, due to internal wear, follows continuous phase-type (PH) distributions. The external random shocks arrive at the system according to a PH renewal process. The system will fail when the internal failure occurs or <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>k</mi><mn>1</mn></msub></mrow></semantics></math></inline-formula> consecutive external shocks, the size of at least <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>d</mi><mn>1</mn></msub></mrow></semantics></math></inline-formula> or <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>k</mi><mn>2</mn></msub></mrow></semantics></math></inline-formula> consecutive external shocks the size of at least <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>d</mi><mn>2</mn></msub></mrow></semantics></math></inline-formula> occur, where <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>d</mi><mn>1</mn></msub><mo><</mo><msub><mi>d</mi><mn>2</mn></msub></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>k</mi><mn>1</mn></msub><mo>></mo><msub><mi>k</mi><mn>2</mn></msub></mrow></semantics></math></inline-formula>. The failed system can be repaired immediately, and the repair times of the system are governed by continuous PH distributions. The system can be replaced by a new and identical one based on a bivariate replacement policy <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo stretchy="false">(</mo><mi>L</mi><mo>,</mo><mi>N</mi><mo stretchy="false">)</mo></mrow></semantics></math></inline-formula>. The long-run average profit rate for the system is obtained by employing the closure property of the PH distribution. Finally, a numerical example is also given to determine the optimal replacement policy.

H. Yin, J. Dou, L. Klein et al.

<p>Iodine and carbonate species are important components in marine and dust aerosols, respectively. The non-ideal interactions between these species and other inorganic and organic compounds within aqueous particle phases affect hygroscopicity, acidity, and gas–particle partitioning of semivolatile components. In this work, we present an extended version of the Aerosol Inorganic–Organic Mixtures Functional groups Activity Coefficients (AIOMFAC) model by incorporating the ions <span class="inline-formula">I⁻</span>, <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msubsup><mi mathvariant="normal">IO</mi><mn mathvariant="normal">3</mn><mo>-</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="20pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="f65f4e887cabea2ebafb5f7dab0ec269"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-22-973-2022-ie00001.svg" width="20pt" height="16pt" src="acp-22-973-2022-ie00001.png"/></svg:svg></span></span>, <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msubsup><mi mathvariant="normal">HCO</mi><mn mathvariant="normal">3</mn><mo>-</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="33pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="9e43ca72024f369b556f82b69154cc14"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-22-973-2022-ie00002.svg" width="33pt" height="16pt" src="acp-22-973-2022-ie00002.png"/></svg:svg></span></span>, <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msubsup><mi mathvariant="normal">CO</mi><mn mathvariant="normal">3</mn><mrow><mn mathvariant="normal">2</mn><mo>-</mo></mrow></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="30pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="708cc15e926e2e8b80b13fc009ea14ba"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-22-973-2022-ie00003.svg" width="30pt" height="17pt" src="acp-22-973-2022-ie00003.png"/></svg:svg></span></span>, <span class="inline-formula">OH⁻</span>, and <span class="inline-formula">CO_2(aq)</span> as new species. First, AIOMFAC ion interaction parameters for aqueous solutions were determined based on available thermodynamic data, such as water activity, mean molal activity coefficients, solubility, and vapor–liquid equilibrium measurements. Second, the interaction parameters for the new ions and various organic functional groups were optimized based on experimental data or, where data are scarce, alternative estimation methods such as multiple linear regression or a simple substitution by analogy approach. Additional bulk water activity and electrodynamic balance measurements were carried out to augment the database for the AIOMFAC parameter fit. While not optimal, we show that the use of alternative parameter estimation methods enables physically sound predictions and offers the benefit of a more broadly applicable model. Our implementation of the aqueous carbonate–bicarbonate–<span class="inline-formula">CO_2(aq)</span> system accounts for the associated temperature-dependent dissociation equilibria explicitly and enables closed- or open-system computations with respect to carbon dioxide equilibration with the gas phase. We discuss different numerical approaches for solving the coupled equilibrium conditions and highlight critical considerations when extremely acidic or basic mixtures are encountered.</p> <p>The fitted AIOMFAC model performance for inorganic aqueous systems is considered excellent over the whole range of mixture compositions where reference data are available. Moreover, the model provides physically meaningful predictions of water activity under highly concentrated conditions. For organic–inorganic mixtures involving new species, the model–measurement agreement is found to be good in most cases, especially at equilibrium relative humidities above <span class="inline-formula">∼</span> 70 %; reasons for deviations are discussed. Several applications of the extended model are shown and discussed, including the effects of ignoring the auto-dissociation of water in carbonate systems, the effects of mixing bisulfate and bicarbonate compounds in closed- or open-system scenarios on pH and solution speciation, and the prediction of critical cloud condensation nucleus activation of <span class="inline-formula">NaI</span> or <span class="inline-formula">Na₂CO₃</span> particles mixed with suberic acid.</p>

Elia Bisi, Yuchen Liao, Axel Saenz et al.

We consider a discrete-time TASEP, where each particle jumps according to Bernoulli random variables with particle-dependent and time-inhomogeneous parameters. We use the combinatorics of the Robinson-Schensted-Knuth correspondence and certain intertwining relations to express the transition kernel of this interacting particle system in terms of ensembles of weighted, non-intersecting lattice paths and, consequently, as a marginal of a determinantal point process. We next express the joint distribution of the particle positions as a Fredholm determinant, whose correlation kernel is given in terms of a boundary-value problem for a discrete heat equation. The solution to such a problem finally leads us to a representation of the correlation kernel in terms of random walk hitting probabilities, generalising the formulation of Matetski, Quastel and Remenik (Acta Math., 2021) to the case of both particle- and time-inhomogeneous rates. The solution to the boundary value problem in the fully inhomogeneous case appears with a finer structure than in the homogeneous case.

Ignatius Leopoldus van Rooyen, Hendrik Gideon Brink, Willie Nicol

Aquatic nitrogen pollution is one of the most urgent environmental issues requiring prevention and mitigation. Large quantities of high-ammonium wastewaters are generated by several industrial sectors, such as fertilizer and anaerobic-digestion plants. Nitrification of these wastewaters is commonly carried out, either to remove nitrogen or produce liquid fertilizers. Standard control methodologies for the efficient nitrification of high-ammonium wastewaters to produce liquid fertilizers have not yet been established and are still within their early stages of development. In this paper, novel pH-based control algorithms are presented that maintain operation at the microbial maximum reaction rate (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>υ</mi><mrow><mi>m</mi><mi>a</mi><mi>x</mi></mrow></msub></mrow></semantics></math></inline-formula>) in batch and continuous reactors. Complete conversion of ammonium to nitrate was achieved in a batch setup, and a conversion of 93% (±1%) was achieved in a continuously-stirred-tank-reactor. The unparalleled performance and affordability of the control schemes proposed offer a steppingstone to the future of sustainable fertilizer production.