Hasil untuk "math-ph"

Junqi Jia, Wenhao Wang, Yulong Liang et al.

Antibiotics have become an integral part of human life and production. The presence of sulfachloropyridazine (SCP), one of the most ubiquitous antibiotics, in water has been a growing concern owing to its long persistence and the difficulty in removing it by conventional water treatment processes. This study introduced ozone (O₃)-activated sodium percarbonate (SPC) as an innovative technique of advanced oxidation processes (AOPs), and the degradation of SCP from water by this method was thoroughly investigated. The impact of a variety of parameters, such as the dosage of SPC, the dosage of O₃, the pH value, and water matrix constituents, on the removal of SCP was evaluated with regard to the pseudo-first-order kinetic model. It was found that the removal effectiveness of SCP improved initially and then decreased with the rising dosage of SPC, with an optimal SPC dose achieved at 20 mg/L. Moreover, •OH, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mrow><mi mathvariant="normal">O</mi></mrow><mrow><mn>2</mn></mrow><mrow><mo>•</mo><mo>−</mo></mrow></msubsup></mrow></semantics></math></inline-formula> and ¹O₂ played important roles during SCP degradation based on radical quenching tests and electron paramagnetic resonance (EPR) tests. The SCP degradation pathways were predicted using density functional theory (DFT), which primarily involves the cleavage of S-C or S-N bonds and Smiles-type rearrangements, accompanied by hydroxylation. Furthermore, the toxicity of degradation intermediates was evaluated by the ECOSAR 1.1 software in terms of acute toxicity and chronic toxicity, and most of them exhibited lower levels of toxicity. The results can expand the research scope of SPC and reveal significant insights for SPC’s application in controlling antibiotic contamination.

Vishmina Obeysekara, Thilini A. Perera, Lasanthi N. C. De Silva et al.

The rising global population and rapid urbanization have increased the demand for food, with many people now living in apartments and leading busy lifestyles that limit their ability to grow plants. Indoor hydroponic cultivation has emerged as a promising solution, offering higher productivity and more efficient use of resources. However, growing and maintaining plants indoors can still be challenging. To address this, we designed and implemented a self-maintaining, IoT-enabled smart pot called &#x201C;GrowSphere&#x201D; for the indoor cultivation of peppermint, aimed at minimizing human intervention and optimizing growth conditions. The system architecture integrates an Arduino microcontroller with multiple sensors, and environmental data are continuously collected through pH, electrical conductivity, and water-level sensors. The system automatically regulates nutrient levels, water supply, and LED light spectra to maintain optimal growth conditions. In addition, GrowSphere supports remote monitoring, data analysis, and prediction of growth patterns. Compared to traditional soil and Deep Water Culture (DWC) hydroponic methods, the proposed approach demonstrates enhanced plant growth rates and yield quality, while reducing labor, water, and energy requirements. Plants grown in the GrowSphere achieved the highest fresh weight (<inline-formula> <tex-math notation="LaTeX">$11.0~\pm ~1.5$ </tex-math></inline-formula> g), with some reaching up to 12.5 g. In contrast, DWC hydroponics (<inline-formula> <tex-math notation="LaTeX">$1.2~\pm ~0.3$ </tex-math></inline-formula> g) and soil cultivation (<inline-formula> <tex-math notation="LaTeX">$0.9~\pm ~0.4$ </tex-math></inline-formula> g) produced significantly lower weights. The proposed system was developed at a cost of approximately USD 268 and built using open-source software, offering a low-cost, sustainable, and high-performance solution for urban plant cultivation.

Jiayu Niu, Siyuan Fan, Zhenjun Wu

Papermaking sludge, rich in intrinsic resource value, is effectively barred from direct deployment in environmental remediation, agriculture, or energy generation by its pronounced contaminant burden. Pyrolytic conversion into high-value paper sludge biochar, such as papermaking sludge biochar (PSBC) provides a green, efficient portal for closing its resource loop. In this study, papermaking sludge was converted into a series of paper sludge biochars (PSBCs) via oxygen-limited pyrolysis at 500–900 °C. The porous architecture, surface physicochemical properties, and crystalline structure of the biochars were comprehensively characterized, and their performance for aqueous tetracycline (TC) removal was systematically quantified. Pyrolysis at 900 °C afforded PSBC 900 with the lowest yield (36.05%) yet the highest Brunauer–Emmett–Teller (BET) surface area (79.53 m²/g), an extensively developed mesopore network, and the greatest degree of graphitization. Across an initial tetracycline (TC) concentration window of 20–160 mg/L, PSBC 900 delivered an equilibrium capacity (q_e) of 72.22 mg/g, outperforming PSBC 700 and PSBC 500 by factors of 1.3 and 1.8, respectively. Optimal uptake was achieved at a dosage of 1.0 g/L, pH 7, and 120 min contact time. Among the background cations examined, Mg²⁺ exerted a pronounced inhibitory effect, whereas Na⁺, K⁺, and Ca²⁺ exerted negligible interference. The adsorption process was accurately described by the pseudo-second-order kinetic model and the Langmuir isotherm (R² > 0.999), yielding a theoretical maximum capacity (q_m) of 76.39 mg/g for PSBC 900 at 313 K. Thermodynamic parameters (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>∆</mo><msup><mrow><mi mathvariant="normal">G</mi></mrow><mrow><mi mathvariant="sans-serif">θ</mi></mrow></msup></mrow></semantics></math></inline-formula> < 0, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>∆</mo><msup><mrow><mi mathvariant="normal">H</mi></mrow><mrow><mi mathvariant="sans-serif">θ</mi></mrow></msup></mrow></semantics></math></inline-formula> > 0, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>∆</mo><msup><mrow><mi mathvariant="normal">S</mi></mrow><mrow><mi mathvariant="sans-serif">θ</mi></mrow></msup></mrow></semantics></math></inline-formula> > 0) confirm a spontaneous, endothermic, and entropy-driven process. After five consecutive adsorption–desorption cycles, PSBC 900 retained >64.68% of its original efficiency, demonstrating excellent regenerability. Paper sludge biochar enables a “waste-to-treat-waste” strategy for the efficient abatement of tetracycline, offering an economically viable and high-performance technology that advances the remediation of tetracycline-laden wastewaters.

P. J. Buchanan, P. J. Buchanan, P. J. Buchanan et al.

<p>Ammonium (NH<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</mn><mo>+</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="9e82b08d319a1c899f60c89d4a61df91"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-4865-2025-ie00001.svg" width="8pt" height="15pt" src="bg-22-4865-2025-ie00001.png"/></svg:svg></span></span>) is an important component of the ocean's dissolved inorganic nitrogen (DIN) pool, especially in stratified marine environments where intense recycling of organic matter elevates its supply over other forms. Using a global-ocean biogeochemical model with good fidelity to the sparse NH<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</mn><mo>+</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="0bd088c5a706fdd4e7871717c05b4b3f"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-4865-2025-ie00002.svg" width="8pt" height="15pt" src="bg-22-4865-2025-ie00002.png"/></svg:svg></span></span> data that are available, we project increases in the NH<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</mn><mo>+</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="43bba5feeea5818072376b211f2a452d"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-4865-2025-ie00003.svg" width="8pt" height="15pt" src="bg-22-4865-2025-ie00003.png"/></svg:svg></span></span> <span class="inline-formula">:</span> DIN ratio in over 98 % of the ocean by the end of the 21st century under a high-emission scenario. This relative enrichment of NH<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M5" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</mn><mo>+</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="aa378b71f34a6c23384fc0eb7c6e7621"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-4865-2025-ie00004.svg" width="8pt" height="15pt" src="bg-22-4865-2025-ie00004.png"/></svg:svg></span></span> is driven largely by circulation changes and secondarily by warming-induced increases in microbial metabolism, as well as reduced nitrification rates due to pH decreases. Supplementing our model projections with geochemical measurements and phytoplankton abundance data from <i>Tara</i> Oceans, we demonstrate that shifts in the form of DIN to NH<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M6" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</mn><mo>+</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="3fe22ea21bb8c3940d1d54b092ea883d"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-4865-2025-ie00005.svg" width="8pt" height="15pt" src="bg-22-4865-2025-ie00005.png"/></svg:svg></span></span> may impact phytoplankton communities by disadvantaging nitrate-dependent taxa like diatoms while promoting taxa better adapted to NH<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M7" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</mn><mo>+</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="a896672a5a2c6d19cc4695ffc843bfde"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-4865-2025-ie00006.svg" width="8pt" height="15pt" src="bg-22-4865-2025-ie00006.png"/></svg:svg></span></span>. This could have cascading effects on marine food webs, carbon cycling and fishery productivity. Overall, the form of bioavailable nitrogen emerges as a potentially underappreciated driver of ecosystem structure and function in the changing ocean.</p>

X. Yang, X. Yang, J. Zhang et al.

<p>Soil humic substances (HSs) typically alter their electrochemical behaviours in the pH range of 1–12, which simultaneously regulates the stability of organo-minerals by modifying the HS functionalities. This process facilitates both biotic and abiotic transformations, which consequently leads to the export of degradative byproducts (e.g. HS components, nutrients) from soils into surrounding aquatic environments through water and/or rainwater discharges. However, the solubility features, environmental consequences, and mechanisms of HSs, including humic acids (HAs), fulvic acids (FAs), and protein-like substances (PLSs), under different pHs remain unclear. To respond to these issues, we used two soil extracts which were fractionated in the pH range from 12–1. The pH-dependent presence or absence of fluorescence peaks in the individual HS components reflected their functional group proton/electron exchange features at both low and high pH values, which were related to their solubility or insolubility. In particular, alkaline pH (<span class="inline-formula">≥pH 9</span>) yielded the anionic forms (<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mo>-</mo><msup><mi mathvariant="normal">O</mi><mo>-</mo></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="25pt" height="12pt" class="svg-formula" dspmath="mathimg" md5hash="b58842d2c2ecdeb84966a6ccdc4f39a8"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-1745-2025-ie00001.svg" width="25pt" height="12pt" src="bg-22-1745-2025-ie00001.png"/></svg:svg></span></span> and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mo>-</mo><msup><mi mathvariant="normal">COO</mi><mo>-</mo></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="41pt" height="12pt" class="svg-formula" dspmath="mathimg" md5hash="4f33c47a94db101714471ec51f281a80"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-1745-2025-ie00002.svg" width="41pt" height="12pt" src="bg-22-1745-2025-ie00002.png"/></svg:svg></span></span>) of phenolic OH and carboxyl groups of HA<span class="inline-formula">_CS</span>, resulting in decreased electron/proton transfer from HS functionalities, as indicated by the decline of fluorescence peak maxima, whereas the protonic functionalities (e.g. –COOH, –OH) of HSs at lower pH resulted in the formation of highly available and remaining uncomplexed HS forms. The solubility of HA fractions increases with increasing pH, whereas their insolubility increases with decreasing pH, which determines their initial precipitation at pH 6 and final precipitation at pH 1, amounting approximately to 39.1 %–49.2 % and 3.1 %–24.1 % of the total dissolved organic matter (DOM), respectively, in the two soils. Elemental analysis results demonstrated that the C and N contents of HA_LS-pH 6 were lower and that those of O, S, and H were higher than those of HA_CS-pH 6, suggesting the preservation of C and N without S acquisition in HA_CS-pH 6, possibly because of their being complexed with minerals, which, in turn, would determine the insolubility of the HA_CS-pH 6 fraction. FA_CS <span class="inline-formula">+</span> PLS_CS showed relatively higher C and S contents and lower O% with respect to FA_LS <span class="inline-formula">+</span> PLS_LS, implying that FA_CS <span class="inline-formula">+</span> PLS_CS would remain under mineral protection. Fourier transform infrared (FTIR) results show significantly reduced infrared absorptions (e.g. 3300–3600 and 800–1200 <span class="inline-formula">cm⁻¹</span>) of HA_CS-pH 6 with respect to HA_LS-pH 6, suggesting the existence of strong intermolecular interactions among HA functional groups, possibly<span id="page1746"/> due to insoluble forms originally complexed with minerals. However, FA_LS <span class="inline-formula">+</span> PLS_LS exhibited stronger bands at 3414–3429 and 1008–1018 <span class="inline-formula">cm⁻¹</span> than FA_CS <span class="inline-formula">+</span> PLS_CS, implying a strong interaction among functional groups possibly derived from various organo-mineral complexes in FA_CS <span class="inline-formula">+</span> PLS_CS. These results would indicate that HS insolubility arises via organo-metal and organo-mineral interactions at alkaline pH, along with HA_pH 6 insolubility via rainwater/water discharge, whereas HA_pH 2 <span class="inline-formula">+</span> FA <span class="inline-formula">+</span> PLS appears to be soluble at acidic pH, thereby being transported in ambient waters via rainwater/water discharge and groundwater infiltration. Therefore, the pH-dependent behaviour of soil HSs greatly contributes to a better understanding of the progressive transformation, mobility/transportation, and immobility/accumulation of HS components under various environmental conditions, with relevant implications for sustainable soil management practices and soil DOM dynamics.</p>

Elisaveta Mladenova, Ralitsa Balkanska, Rositsa Shumkova

The objective of this work was to determine and compare a comprehensive set of quality markers, including main physicochemical properties and element profiles, in samples of Bulgarian oak honeydew honey (OHH) and coniferous honeydew honey (CHH). This investigation utilized a total of seventeen honey samples from Bulgaria harvested in 2022. The sample set comprised ten oak honeydew honey samples, sourced from the Burgas region, and seven coniferous honeydew honey samples obtained from the Smolyan region. The parameters of OHH samples varied within the following ranges: color (80–134 mm Pfund), water content (15.20–18.40%), electrical conductivity (0.80–1.33 mS/cm), specific optical rotation (2.25–12.50 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mrow><mo>[</mo><mi>α</mi><mo>]</mo></mrow><mrow><mi>D</mi></mrow><mrow><mn>20</mn></mrow></msubsup></mrow></semantics></math></inline-formula>), pH (3.92–4.50), total acidity (29.80–36.80 meq/kg), diastase activity (18.36–27.58 Gothe units), invertase activity (56–196 U/kg), proline content (155–477 mg/kg), and hydroxymethylfurfural (3.28–8.94 mg/kg). The CHH samples gave the following results: color (40–87 mm Pfund), water content (16.40–19.00%), electrical conductivity (0.80–1.26 mS/cm), specific optical rotation (−17.50–(−11.50 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mrow><mo>[</mo><mi>α</mi><mo>]</mo></mrow><mrow><mi>D</mi></mrow><mrow><mn>20</mn></mrow></msubsup></mrow></semantics></math></inline-formula>)), pH (3.40–3.75), total acidity (25.80–39.40 meq/kg), diastase activity (23.15–26.05 Gothe units), invertase activity (69–138 U/kg), proline content (287–651 mg/kg), and hydroxymethylfurfural (1.50–3.96 mg/kg). The elements Ca, Cu, Fe, Mg, and Mn were determined by Flame Atomic Absorption Spectrometer (FAAS), while Flame Atomic Emission Spectrometry (FAES) was used for K and Na determination. Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) analysis was used to assess six elements (Al, Ba, Co, P, Sr, Zn). The elements Cd, Ni, and Pb were determined by Electrothermal Atomic Absorption Spectrometry (ETAAS). Potassium is the most abundant macro element in all investigated samples ranging 2332–2370 µg/g in CHH and 1846–1878 µg/g in OHH. Other examined elements are in the following descending order, Mg > P > Na > Ca > Mn > Al > Fe > Zn > Cu > Ba > Sr, presenting in µg/g levels, while Pb > Ni > Co > Cd are present in µg/kg levels. This work constitutes the first report on the physicochemical parameters and chemical elements of coniferous honeydew honey from Bulgaria.

Dajun Yuan, Bo-Hui Tang, Dong Wang et al.

The frequency and spatial extent of cyanobacterial bloom outbreaks have increased in recent years due to climate warming and human activities, causing significant harm to inland water ecosystems. Phycocyanin (PC), a characteristic pigment of cyanobacteria, plays a crucial role in detecting cyanobacterial blooms and providing early warnings. However, accurately estimating PC in turbid waters using remote sensing is challenging due to the optical complexity of most inland waters and the relatively weak optical signal of PC. To address this issue, an enhanced three-band algorithm (ETBA) is proposed for retrieving PC concentration in inland waters. Since the PC absorption feature at 620 nm is prone to interference from non-PC pigments, the algorithm incorporates the quantification of the absorption coefficient of non-PC pigments at 620 nm (<inline-formula><tex-math notation="LaTeX">${{{\bm{a}}}_{{\bm{ph}} - {\bm{pc}}}}( {620} )$</tex-math></inline-formula>) to improve the accurate of estimating <inline-formula><tex-math notation="LaTeX">${{{\bm{a}}}_{{\bm{pc}}}}( {620} )$</tex-math></inline-formula>. Using in situ observation data from Erhai Lake as an example, the results show that ETBA significantly outperforms the original three-band algorithm in mitigating interference from non-PC pigments. Among all the phycocyanin (PC) algorithms considered in this study, the Enhanced Three Band Algorithm (ETBA) achieved the lowest mean relative error (12.76&#x0025;) and a goodness of fit of (<italic>R</italic>² &#x003D; 0.73), with the second lowest root mean square error of 0.37 &#x03BC;g/L. Therefore, the introduction of the ETBA has a direct positive impact on monitoring harmful algal blooms caused by cyanobacteria in inland and coastal water.

Francesca Razzano, Pietro Di Stasio, Francesco Mauro et al.

Differently from conventional procedures, the proposed solution advocates for a groundbreaking paradigm in water quality monitoring through the integration of satellite Remote Sensing data, Artificial Intelligence techniques, and onboard processing. While conventional procedures present several drawbacks mainly related to late intervention capabilities, the objective of what proposed is to offer nearly real-time detection of contaminants in coastal waters addressing a significant gap in the existing literature and allowing fast alerts and intervention. In fact, the expected outcomes include substantial advancements in environmental monitoring, public health protection, and resource conservation. Namely, the specific focus of our study is on the estimation of Turbidity and pH parameters, for their implications on human and aquatic health. Nevertheless, the designed framework can be extended to include other parameters of interest in the water environment and beyond. Originating from our participation in the European Space Agency OrbitalAI Challenge, this article describes the distinctive opportunities and issues for the contaminants&#x0027; monitoring on the <inline-formula><tex-math notation="LaTeX">$\Phi$</tex-math></inline-formula>sat-2 mission. The specific characteristics of this mission, with the tools made available, will be presented, with the methodology proposed by the authors for the onboard monitoring of water contaminants in near real-time. Preliminary promising results are presented, along with an introduction to ongoing and future work.

Angel Tlatelpa Becerro, Ramiro Rico Martínez, Guillermo Raúl Carbajal Pérez et al.

The drying kinetics and physical and chemical characteristics of <i>Leucaena esculenta</i> seed drying using a forced convection solar dryer are described. The drying kinetics behavior is examined for three experiments under climate conditions of three different winter days in central Mexico, observing significant effects related to the reported pH levels of the seeds with values of 6.34, 5.98, 5.97, 5.82, and 6.07. The airflow measurements inside the drying chamber were observed, including the geometric dimensions, color, appearance, weight, and moisture loss, and the effective diffusivity coefficient <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced separators="|"><mrow><msub><mrow><mi>D</mi></mrow><mrow><mi>e</mi><mi>f</mi><mi>f</mi></mrow></msub></mrow></mfenced></mrow></semantics></math></inline-formula> of <i>Leucaena esculenta</i> with values between 1.23 × 10⁻⁷ and 8.09 × 10⁻⁹ <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mstyle scriptlevel="0" displaystyle="true"><mfrac><mrow><msup><mrow><mi mathvariant="normal">m</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow><mrow><mi mathvariant="normal">s</mi></mrow></mfrac></mstyle></mrow></semantics></math></inline-formula>. Solar drying, with the technology used in this study, is a viable alternative to give added value to <i>Leucaena esculenta</i>. This study can be the basis for developing alternatives to preserve seeds for animal and human consumption.

Boglárka Páll, Róbert Kormány, Krisztián Horváth

In ion chromatography studies, the matrix effect of other inorganic ions present in the sample is a well-known phenomenon. In this work, the behavior of inorganic and organic ions was studied in a system overloaded with ammonium ions. The ammonium ions came from a solution of ammonium hydroxide in various concentrations (0.25–1.25%). In this system, which was significantly overloaded with ammonium ions, the behavior of three ions were tested (lithium, tris, and sodium cations). The measurements were performed at different eluent concentrations (6–17 mM), chromatographic column temperatures (25–40 °C), and injected volumes (15–40 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">µ</mi></semantics></math></inline-formula>L). The retention times of sodium and lithium ions increased with increasing amounts of injected ammonium, while tris remained essentially unchanged, indicating that the resolution of these ions can be influenced by varying the concentration of the matrix. The results suggested that the observed effect was due to a combination of the pH change caused by the injected matrix, the dissociation of tris ions, the dissociation of the carbocylic ion-exchange groups of stationary phase, the change in buffer capacity, and the amount of ammonium ion introduced. It has been shown that in a well-designed experiment, the addition of ammonium hydroxide to the sample at concentrations greater than 1% can improve the efficiency of organic and inorganic cation separation. It was found that 8 mM methanesulfonic acid eluent, 30 °C, 1% ammonium hydroxide matrix concentration, and 25 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">µ</mi></semantics></math></inline-formula>L injection were optimal for the baseline separation of tris and sodium ions on the high-capacity Dionex CS16 column. These ions could not be separated on this column without the presence of the ammonium matrix.

E. Chiapponi, S. Silvestri, D. Zannoni et al.

<p>Coastal wetlands play a fundamental role in mitigating climate change thanks to their ability to store large amounts of organic carbon in the soil. However, degraded freshwater wetlands are also known to be the first natural emitter of methane (<span class="inline-formula">CH₄</span>). Salinity is known to inhibit <span class="inline-formula">CH₄</span> production, but its effect in brackish ecosystems is still poorly understood. This study provides a contribution to understanding how environmental variables may affect greenhouse gas (GHG) emissions in coastal temperate wetlands. We present the results of over 1 year of measurements performed in four wetlands located along a salinity gradient on the northeast Adriatic coast near Ravenna, Italy. Soil properties were determined by coring soil samples, while carbon dioxide (<span class="inline-formula">CO₂</span>) and <span class="inline-formula">CH₄</span> fluxes from soils and standing waters were monitored monthly by a portable gas flux meter. Additionally, water levels and surface and groundwater physical–chemical parameters (temperature, pH, electrical conductivity, and sulfate concentrations of water) were monitored monthly by multiparametric probes. We observed a substantial reduction in <span class="inline-formula">CH₄</span> emissions when water depth exceeded the critical threshold of 50 <span class="inline-formula">cm</span>. Regardless of the water salinity value, the mean <span class="inline-formula">CH₄</span> flux was 5.04 <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M12" display="inline" overflow="scroll" dspmath="mathml"><mrow class="unit"><mi mathvariant="normal">g</mi><mspace width="0.125em" linebreak="nobreak"/><msup><mi mathvariant="normal">m</mi><mrow><mo>-</mo><mn mathvariant="normal">2</mn></mrow></msup><mspace linebreak="nobreak" width="0.125em"/><msup><mi mathvariant="normal">d</mi><mrow><mo>-</mo><mn mathvariant="normal">1</mn></mrow></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="47pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="b790de44938efcdc0f4fd466e647e96a"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-21-73-2024-ie00001.svg" width="47pt" height="15pt" src="bg-21-73-2024-ie00001.png"/></svg:svg></span></span> in freshwater systems and 12.27 <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M13" display="inline" overflow="scroll" dspmath="mathml"><mrow class="unit"><mi mathvariant="normal">g</mi><mspace width="0.125em" linebreak="nobreak"/><msup><mi mathvariant="normal">m</mi><mrow><mo>-</mo><mn mathvariant="normal">2</mn></mrow></msup><mspace width="0.125em" linebreak="nobreak"/><msup><mi mathvariant="normal">d</mi><mrow><mo>-</mo><mn mathvariant="normal">1</mn></mrow></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="47pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="cb43a188c95fe696e3461dcd2324554f"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-21-73-2024-ie00002.svg" width="47pt" height="15pt" src="bg-21-73-2024-ie00002.png"/></svg:svg></span></span> in brackish ones. In contrast, when water depth was shallower than 50 <span class="inline-formula">cm</span>, <span class="inline-formula">CH₄</span> fluxes reached an average of 196.98 <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M16" display="inline" overflow="scroll" dspmath="mathml"><mrow class="unit"><mi mathvariant="normal">g</mi><mspace linebreak="nobreak" width="0.125em"/><msup><mi mathvariant="normal">m</mi><mrow><mo>-</mo><mn mathvariant="normal">2</mn></mrow></msup><mspace width="0.125em" linebreak="nobreak"/><msup><mi mathvariant="normal">d</mi><mrow><mo>-</mo><mn mathvariant="normal">1</mn></mrow></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="47pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="c5c90d706a9f2a32c73f90e483d87b36"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-21-73-2024-ie00003.svg" width="47pt" height="15pt" src="bg-21-73-2024-ie00003.png"/></svg:svg></span></span> in freshwater systems, while non-significant results are available for brackish/saline waters. Results obtained for <span class="inline-formula">CO₂</span> fluxes showed the same behavior described for <span class="inline-formula">CH₄</span> fluxes, even though they were statistically non-significant. Temperature and irradiance strongly influenced <span class="inline-formula">CH₄</span> emissions from water and soil, resulting in higher rates during summer and spring.</p>

Pengyao Miao, Xiaomin Pang, Mengzhen Zhang et al.

As the global demand for high-quality tea increases, adopting sustainable agricultural practices is crucial to maintaining environmental health and improving crop productivity. Employing organic fertilizers has the potential to boost agricultural output and improve soil health, as well as curb the spread of pests and diseases. The purpose of this survey was to determine the impact of a range of organic fertilizer mixtures on both tea plants and rhizosphere soil characteristics in tea plantations. This study investigated the response of Jin Guanyin tea (<i>Camellia sinensis</i> L.) plants to various organic fertilizer ratios: 2/3 chemical fertilizer + 1/3 organic fertilizer (JTC), 1/2 chemical fertilizer + 1/2 organic fertilizer (JHOC), 1/3 chemical fertilizer + 2/3 organic fertilizer (JTO), and organic fertilizer only (JOF), with chemical fertilizer alone (JCF) as the control. The experiment was conducted in Xingcun Town, Wuyishan, Fujian Province, China, on 13 October 2021. Key metrics measured included tea plant growth indicators, soil physicochemical properties, enzyme activities, and microbial functional diversity. Results show that JTC and JTO produce the largest leaf area and bud weight, significantly surpassing those in JCF. JCF demonstrated the longest new tip length and highest bud density, while JHOC achieved the highest chlorophyll content, significantly exceeding JCF. Soil analysis revealed that total nitrogen, available nitrogen, organic matter, and pH were highest in JOF, significantly overtaking JCF. Conversely, total phosphorus, available potassium, and available phosphorus levels were highest in JCF. JHOC also had the highest total potassium content compared to JCF. Soil enzyme activity assessments showed that polyphenol oxidase and urease activities peaked in JTC, significantly exceeding those in JCF. JHOC exhibited the highest acid phosphatase activity, while JTO exhibited the highest protease activity. Catalase activity was highest in JOF, both significantly surpassing JCF. Microbial functional diversity analysis indicated that combined organic fertilization improved soil microorganisms’ utilization of carbon sources, significantly enhancing the Shannon diversity index and evenness. Key carbon sources identified included <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">α</mi></semantics></math></inline-formula>-cyclodextrin, D-galacturonic acid, and 4-hydroxy benzoic acid. Overall, JHOC emerged as the optimal fertilization strategy, yielding superior growth indicators, enhanced soil physicochemical properties, increased enzyme activity, and improved microbial functional diversity compared to JCF. This study has important value for guiding the rational application of fertilizers in tea gardens, improving the soil environment of tea gardens, enhancing the quality of tea leaves, and achieving sustainable tea production.

P.-C. Huang, H.-M. Hung, H.-C. Lai et al.

<p>Taiwan experiences higher air pollution in winter when fine particulate matter (PM<span class="inline-formula">_2.5</span>) levels frequently surpass national standards. This study employs the Community Multiscale Air Quality model to assess the effectiveness of reducing SO<span class="inline-formula">₂</span>, NO<span class="inline-formula">_<i>x</i></span>, and NH<span class="inline-formula">₃</span> emissions on PM<span class="inline-formula">_2.5</span> secondary inorganic species (i.e., SO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M11" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">4</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="6181d6711c50a62cc80d469e7dc67eab"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-24-10759-2024-ie00001.svg" width="13pt" height="17pt" src="acp-24-10759-2024-ie00001.png"/></svg:svg></span></span>, NO<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M12" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">3</mn><mo>-</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="9pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="ee54bb0fff66afdafaf51bed1fde360d"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-24-10759-2024-ie00002.svg" width="9pt" height="16pt" src="acp-24-10759-2024-ie00002.png"/></svg:svg></span></span>, and NH<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">4</mn><mo>+</mo></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="f1ca5762abf079d28af10bf21d382d4c"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-24-10759-2024-ie00003.svg" width="8pt" height="15pt" src="acp-24-10759-2024-ie00003.png"/></svg:svg></span></span>). For sulfate, <span class="inline-formula">∼</span> 43.7 % is derived from the chemical reactions of local SO<span class="inline-formula">₂</span> emission, emphasizing the substantial contribution of regionally transported sulfate. In contrast, nitrate and ammonium are predominantly influenced by local NO<span class="inline-formula">_<i>x</i></span> and NH<span class="inline-formula">₃</span> emissions. Reducing SO<span class="inline-formula">₂</span> emissions decreases sulfate levels, which in turn leads to more NH<span class="inline-formula">₃</span> remaining in the gas phase, resulting in lower ammonium concentrations. Similarly, reducing NO<span class="inline-formula">_<i>x</i></span> emissions lowers HNO<span class="inline-formula">₃</span> formation, impacting nitrate and ammonium concentrations by decreasing the available HNO<span class="inline-formula">₃</span> and leaving more NH<span class="inline-formula">₃</span> in the gas phase. A significant finding is that reducing NH<span class="inline-formula">₃</span> emissions decreases not only ammonium and nitrate but also sulfate by altering cloud droplet pH and SO<span class="inline-formula">₂</span> oxidation processes. While the impact of SO<span class="inline-formula">₂</span> reduction on PM<span class="inline-formula">_2.5</span> is less than that of NO<span class="inline-formula">_<i>x</i></span> and NH<span class="inline-formula">₃</span>, it emphasizes the complexity of regional sensitivities. Most of western Taiwan is NO<span class="inline-formula">_<i>x</i></span>-sensitive, so reducing NO<span class="inline-formula">_<i>x</i></span> emissions has a more substantial impact on lowering PM<span class="inline-formula">_2.5</span> levels. However, given the higher mass emissions of NO<span class="inline-formula">_<i>x</i></span> than NH<span class="inline-formula">₃</span> in Taiwan, NH<span class="inline-formula">₃</span> has a more significant consequence in mitigating PM<span class="inline-formula">_2.5</span> per unit mass emission reduction (i.e., 2.43 <span class="inline-formula">×</span> 10<span class="inline-formula">⁻⁵</span> and 0.85 <span class="inline-formula">×</span> 10<span class="inline-formula">⁻⁵</span> <span class="inline-formula">µ</span>g m<span class="inline-formula">⁻³</span> (t yr<span class="inline-formula">⁻¹</span>)<span class="inline-formula">⁻¹</span>​​​​​​​ for NH<span class="inline-formula">₃</span> and NO<span class="inline-formula">_<i>x</i></span>, respectively, under current emission reduction). The cost-effectiveness analysis suggests that NH<span class="inline-formula">₃</span> reduction outperforms SO<span class="inline-formula">₂</span> and NO<span class="inline-formula">_<i>x</i></span> reduction (i.e., USD 0.06 billion yr<span class="inline-formula">⁻¹</span> <span class="inline-formula">µ</span>g<span class="inline-formula">⁻¹</span> m<span class="inline-formula">³</span>, USD 0.1 billion yr<span class="inline-formula">⁻¹</span> <span class="inline-formula">µ</span>g<span class="inline-formula">⁻¹</span> m<span class="inline-formula">³</span>, and USD 1 billion yr<span class="inline-formula">⁻¹</span> <span class="inline-formula">µ</span>g<span class="inline-formula">⁻¹</span> m<span class="inline-formula">³</span> for NH<span class="inline-formula">₃</span>, SO<span class="inline-formula">₂</span>, and NO<span class="inline-formula">_<i>x</i></span>, respectively, under the current emission reduction). Nevertheless, the costs of emission reduction vary due to differences in methodology and regional emission sources. Overall, this study considers both the efficiency and costs, highlighting NH<span class="inline-formula">₃</span> emissions reduction as a promising strategy for PM<span class="inline-formula">_2.5</span> mitigation in the studied environment in Taiwan.</p>

Hong-Chao Luo, Feng-Yin Li, Ya-Nan Zhang et al.

In this work, the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced><mrow><mi>n</mi><mo>,</mo><mi>n</mi></mrow></mfenced></mrow></semantics></math></inline-formula>-type nanotube systems rolled up from the B/N substituted Me-graphene (i.e., Me-CBNT and Me-CNN, respectively) were investigated with the aid of the density functional theory (DFT). Due to the lattice dynamic instabilities until <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>n</mi><mo>=</mo><mn>10</mn></mrow></semantics></math></inline-formula>, the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced><mrow><mi>n</mi><mo>,</mo><mn>0</mn></mrow></mfenced></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced><mrow><mi>n</mi><mo>,</mo><mi>m</mi></mrow></mfenced></mrow></semantics></math></inline-formula> nanotube systems were not involved in this study. According to our calculations at the Perdew-Burke-Ernzerhof (PBE) level, the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced><mrow><mi>n</mi><mo>,</mo><mi>n</mi></mrow></mfenced></mrow></semantics></math></inline-formula> Me-CBNT and Me-CNNT systems possess excellent mechanical strengths. The Young’s moduli of Me-CBNTs can reach 60% of single-walled carbon nanotubes (SWCNTs), while their mass densities are only around 70% of SWCNTs. Based on the fully relaxed geometric configurations at the PBE level, the electronic configurations of the related nanotubes were evaluated by using the global hybrid functional B3LYP with 36% Fock exchanges. The <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced><mrow><mi>n</mi><mo>,</mo><mi>n</mi></mrow></mfenced></mrow></semantics></math></inline-formula> Me-CBNTs are metallic, while the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced><mrow><mi>n</mi><mo>,</mo><mi>n</mi></mrow></mfenced></mrow></semantics></math></inline-formula> Me-CNNTs are semiconductors with the inherent band gaps in the range of 3.08 eV to 3.31 eV. The Bloch flat bands appear on both sides of their Fermi levels, indicating the localized charge carriers. Their band edge arrangements imply that these materials are promising candidates for the photocatalytic water splitting reactions at certain pH values.

Tal Elbaz, Ankit Chauhan, Aviran Halstuch et al.

Experimental limitations such as design complexity and low optical throughput have prevented photonic nanojet (PNJ) and photonic hook (PH) measurements from demonstrating and characterizing the implementation of narrow intense electromagnetic beams generated from dielectric microelements with circular symmetry. Near-fields optical microscopy can mitigate these limitations and still present a capability of detecting a highly localized electromagnetic beam for applications in step-index media. Here we model a localized PNJ and PH formation in step-index media. We show that despite negligible refractive index contrast between the water (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>n</mi><mrow><mi>w</mi><mi>a</mi><mi>t</mi><mi>e</mi><mi>r</mi></mrow></msub><mo>=</mo><mn>1.33</mn></mrow></semantics></math></inline-formula>) and silica microcylinder (∼1.1), a formation of PNJ and PH is observed with equivalent performance compared to that of silica microcylinder embedded in air (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>n</mi><mrow><mi>a</mi><mi>i</mi><mi>r</mi></mrow></msub><mo>=</mo><mn>1</mn></mrow></semantics></math></inline-formula>). This model features a practical fiber source and silica microcylinder as an auxiliary structure. Simultaneously, we performed experimental characterization of a photonic nanojet generated from an optical fiber and studied the resulting near-fields. Our electromagnetic simulation results are in good agreement with the experimental ones, demonstrating a full width at half maximum (FHWM) with a relative error of 0.64%. This system will make fiber-based nanojet realization and characterization accessible and practical for optics and laser engineering applications, super-resolution imaging, and nanolithography.

Selvaraj Chinnathambi, Mahinder Ramdin, Thijs J. H. Vlugt

Mass transport of different species plays a crucial role in electrochemical conversion of 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> due to the solubility limit of 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> in aqueous electrolytes. In this study, we investigate the transport of 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> and other ionic species through the electrolyte and the membrane, and its impact on the scale-up process of HCOO<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mo>−</mo></msup></semantics></math></inline-formula>/HCOOH formation. The mass transport of ions to the electrode and the membrane is modelled at constant current density. The mass transport limitations of 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> on the formation of HCOO<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mo>−</mo></msup></semantics></math></inline-formula>/HCOOH is investigated at different pressures ranges from 5–40 bar. The maximum achievable partial current density of formate/formic acid is increased with increasing 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> pressure. We use an ion exchange membrane model to understand the ion transport behaviour for both the monopolar and bipolar membranes. The cation exchange (CEM) and anion exchange membrane (AEM) model show that ion transport is limited by the electrolyte salt concentrations. For 0.1 M KHCO<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>3</mn></msub></semantics></math></inline-formula>, the AEM reaches the limiting current density more quickly than the CEM. For the BPM model, ion transport across the diffusion layer on either side of the BPM is also included to understand the concentration polarization across the BPM. The model revealed that the polarization losses across the bipolar membrane depend on the pH of the electrolyte used for the 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> reduction reaction (CO₂RR). The polarization loss on the anolyte side decreases with an increasing pH, while, on the cathode side, it increases with increasing catholyte pH. With this combined model for the electrode reactions and the membrane transport, we are able to account for the various factors influencing the polarization losses in the 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> electrolyzer. To complete the analysis, we simulated the full cell polarization curve and fitted with the experimental data.

C. Wu, C. Cao, C. Cao et al.

<p>To understand the chemical evolution of aerosols in the transport process, the chemistry of PM<span class="inline-formula">_2.5</span> and nitrogen isotope compositions on the mountainside of Mt. Hua (<span class="inline-formula">∼1120</span> m above sea level, a.s.l.) in inland China during the 2016 summertime were investigated and compared with parallel observations collected at surface sampling site (<span class="inline-formula">∼400</span> m a.s.l.). The PM<span class="inline-formula">_2.5</span> exhibited a high level at the mountain foot site (MF; average <span class="inline-formula">76.0±44.1</span> <span class="inline-formula">µg m⁻³</span>) and could be transported aloft by anabatic valley winds, leading to the gradual accumulation of daytime PM<span class="inline-formula">_2.5</span> with a noon peak at the mountainside sampling site (MS). As the predominant ion species, sulfate exhibited nearly identical mass concentrations at both sites, but its PM<span class="inline-formula">_2.5</span> mass fraction was moderately enhanced by <span class="inline-formula">∼4</span> % at the MS site. The ammonium variations were similar to the sulfate variations, the chemical forms of both of which mainly existed as ammonium bisulfate (<span class="inline-formula">NH₄HSO₄</span>) and ammonium sulfate (<span class="inline-formula">(NH₄)₂SO₄</span>) at the MF and MS sites, respectively. Unlike sulfate and ammonium, nitrate mainly existed as ammonium nitrate (<span class="inline-formula">NH₄NO₃</span>) in fine particles and exhibited decreasing mass concentration and proportion trends with increasing elevation. This finding was ascribed to <span class="inline-formula">NH₄NO₃</span> volatilization, in which gaseous <span class="inline-formula">HNO₃</span> from semi-volatile <span class="inline-formula">NH₄NO₃</span> subsequently reacted with dust particles to form nonvolatile salts, resulting in significant nitrate shifts from fine particles into coarse particles. Such scavenging of fine-particle nitrate led to an enrichment in the daytime <span class="inline-formula">¹⁵N</span> of nitrate at the MS site compared with to the MF site. In contrast to nitrate, at the MS site, the <span class="inline-formula">¹⁵N</span> in ammonium depleted during the daytime. Considering the lack of any significant change in ammonia (<span class="inline-formula">NH₃</span>) sources during the vertical transport process, this <span class="inline-formula">¹⁵N</span> depletion in ammonium was mainly the result of unidirectional reactions, indicating that additional <span class="inline-formula">NH₃</span> would partition into particulate phases and further neutralize <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M21" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msubsup><mi mathvariant="normal">HSO</mi><mn mathvariant="normal">4</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="199dd3dfc9db731a72551032f2dfcb05"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-22-15621-2022-ie00001.svg" width="33pt" height="16pt" src="acp-22-15621-2022-ie00001.png"/></svg:svg></span></span> to form <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M22" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msubsup><mi mathvariant="normal">SO</mi><mn mathvariant="normal">4</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="29pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="47e678c4680581e78f7a83f3b1df9ebc"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-22-15621-2022-ie00002.svg" width="29pt" height="17pt" src="acp-22-15621-2022-ie00002.png"/></svg:svg></span></span>. This process would reduce the aerosol acidity, with a higher pH (<span class="inline-formula">3.4±2.2</span>) at the MS site and lower ones (<span class="inline-formula">2.9±2.0</span>) at the MF site. Our work provides more insight into physicochemical behaviors of semi-volatile nitrate and ammonium, which will facilitate the improvement in the model for a better simulation of aerosol composition and properties.</p>

Cristina Medina-Bailon, Naveen Kumar, Rakshita Pritam Singh Dhar et al.

In this work, we present a comprehensive analytical model and results for an absolute pH sensor. Our work aims to address critical scientific issues such as: (1) the impact of the oxide degradation (sensing interface deterioration) on the sensor’s performance and (2) how to achieve a measurement of the absolute ion activity. The methods described here are based on analytical equations which we have derived and implemented in MATLAB code to execute the numerical experiments. The main results of our work show that the depletion width of the sensors is strongly influenced by the pH and the variations of the same depletion width as a function of the pH is significantly smaller for hafnium dioxide in comparison to silicon dioxide. We propose a method to determine the absolute pH using a dual capacitance system, which can be mapped to unequivocally determine the acidity. We compare the impact of degradation in two materials: SiO<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> and HfO<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>, and we illustrate the acidity determination with the functioning of a dual device with SiO<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>.

Manuel de León, Manuel Lainz, Asier López-Gordón

This paper is devoted to the study of mechanical systems subjected to external forces in the framework of symplectic geometry. We obtain a Noether's theorem for Lagrangian systems with external forces, among other results regarding symmetries and conserved quantities. We particularize our results for the so-called Rayleigh dissipation, i.e., external forces that are derived from a dissipation function, and illustrate them with some examples. Moreover, we present a theory for the reduction of Lagrangian systems subjected to external forces which are invariant under the action of a Lie group.

Arik Pujiyanti, Sulhadi Sulhadi, Mahardika Prasetya Aji

The use of chemical fertilizers that are not balanced with the provision of organic fertilizers can damage the soil. Chemical fertilizers can also damage the balance of nutrients in the soil and lower soil pH. Therefore, organic fertilizers are needed to help restore soil fertility and LRB as a medium for composting organic fertilizers. The biopore infiltration hole (LRB) is "activated" by providing organic waste. This waste will be used as a source of energy for soil organisms to carry out their activities through the decomposition process. This decomposed waste is known as compost. Compost is a term for man-made organic fertilizer made from the decomposition process of the remains of living things (plants or animals). The investigation of this study was to determine the quality of compost based on light intensity and acidity (pH) from the results of biopore infiltration holes (LRB) as well as good physical properties of compost. This type of research is an experimental research. Good quality compost has low resistance. The pH value of the compost in samples A,B,D,E is 6.5-7.5 so it is neutral, while the pH of the compost sample C is 8.5 is alkaline. The intensity of the light is high. The results of the lowest light intensity in the compost from this study were leaf compost + sawdust + EM4 of 990 lux, fermented in LRB for 2 weeks. Meanwhile, the highest light intensity value was found in the compost of raw material leaves which were fermented for 1 month at 1017 lux. So the greater the value of light intensity in the compost, the better quality it has, because it can improve soil fertility. ©2019 JNSMR UIN Walisongo. All rights reserved.