Hasil untuk "math-ph"

Chenxue Su, Jia Che, Zehao Wu et al.

In this study, the non-destructive determination of pH, total soluble solids (TSS), total acidity (TA), reducing sugars (RS), seed total phenolic content (TPCD), and skin total phenolic content (TPCN) in Ugni Blanc grapes was performed using visible/near-infrared (Vis/NIR) spectroscopy coupled with chemometric quantitative analysis. Diffuse reflectance spectra in the 400–1507 nm range were measured using a handheld Vis–NIR spectrometer, after which the dataset was partitioned using the SPXY algorithm, accounting for joint X-Y distances. Six spectral preprocessing methods and three modeling algorithms, Partial Least Squares (PLS), Support Vector Machine Regression (SVR), and Convolutional Neural Network (CNN), were used to construct quantitative models based on full-wavelength and feature-wavelength data. Feature-based models outperformed full-spectrum models for TA, RS, and TPCN, whereas full-spectrum models performed better for pH, TSS, and TPCD. The optimal models achieved <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mrow><msubsup><mrow><mi mathvariant="italic">R</mi></mrow><mrow><mi mathvariant="italic">p</mi></mrow><mrow><mn mathvariant="italic">2</mn></mrow></msubsup></mrow></mrow></semantics></math></inline-formula> values of 0.940, 0.957, 0.913, 0.889, 0.917, and 0.871 and <i>RPD</i> values of 4.074, 4.798, 3.397, 2.998, 2.904, and 2.786, correspondingly. The findings highlight the applicability of Vis/NIR spectroscopy for the accurate and non-destructive prediction of key physicochemical indicators in Ugni Blanc grapes.

H. Zhang, H. Zhang, S. Wang et al.

<p>Particle acidity serves as a key determinant in atmospheric chemical processes. Emerging concerns regarding aerosol acidity trends have been highlighted amid China's sustained initiatives to mitigate emissions of both acidic and alkaline precursors, especially in North China, which is significantly affected by dust aerosol. 12-year observational data in Zhengzhou reveal that the annual average <span class="inline-formula">PM_2.5</span> concentration decreased from <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow><mn mathvariant="normal">162</mn><mo>±</mo><mn mathvariant="normal">81</mn><mspace linebreak="nobreak" width="0.125em"/><mrow class="unit"><mi mathvariant="normal">µ</mi><mi mathvariant="normal">g</mi><mspace linebreak="nobreak" width="0.125em"/><msup><mi mathvariant="normal">m</mi><mrow><mo>-</mo><mn mathvariant="normal">3</mn></mrow></msup></mrow></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="78pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="1a4aa4fbe0af84bc430f08a7efccb361"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-25-6943-2025-ie00001.svg" width="78pt" height="15pt" src="acp-25-6943-2025-ie00001.png"/></svg:svg></span></span> in 2011 to <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow><mn mathvariant="normal">60</mn><mo>±</mo><mn mathvariant="normal">41</mn><mspace linebreak="nobreak" width="0.125em"/><mrow class="unit"><mi mathvariant="normal">µ</mi><mi mathvariant="normal">g</mi><mspace width="0.125em" linebreak="nobreak"/><msup><mi mathvariant="normal">m</mi><mrow><mo>-</mo><mn mathvariant="normal">3</mn></mrow></msup></mrow></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="72pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="35a55c93e066c64a97a6a33966b6bee8"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-25-6943-2025-ie00002.svg" width="72pt" height="15pt" src="acp-25-6943-2025-ie00002.png"/></svg:svg></span></span> in 2022, with the largest reduction in sulfate (73 %). Correspondingly, the annual particle pH increased by 0.10 units from 2011–2019. In addition, the elevated particle pH in 2015 and 2018 was notably influenced by the increase in <span class="inline-formula">TNH_<i>x</i></span> (<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M5" display="inline" overflow="scroll" dspmath="mathml"><mrow><mrow class="chem"><msub><mi mathvariant="normal">NH</mi><mn mathvariant="normal">3</mn></msub></mrow><mo>+</mo><mrow class="chem"><msubsup><mi mathvariant="normal">NH</mi><mn mathvariant="normal">4</mn><mo>+</mo></msubsup></mrow></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="56pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="fd141197a09f622e01fcf44e044acac8"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-25-6943-2025-ie00003.svg" width="56pt" height="15pt" src="acp-25-6943-2025-ie00003.png"/></svg:svg></span></span>). Note that the crustal material concentrations and their proportions increased significantly during 2019–2022, which might be responsible for the resuspension of surrounding soil dust. Even though the <span class="inline-formula">TNH_<i>x</i></span> concentration was decreasing, the annual average growth rate of pH values increased to 0.21 units from 2019–2022. This phenomenon is not unique to Zhengzhou, as major cities in the North China Plain have also experienced a pronounced upward trend in coarse particles after 2019. Therefore, the long-term evolution of particle acidity in North China will require comprehensive consideration of synergistic effects involving acidic precursors, ammonia, and crustal materials.</p>

Shanti-Maryse Gutiérrez-Magaña, Noel García-Díaz, Leonel Soriano-Equigua et al.

Agriculture is essential for food production and raw materials. A key aspect of this sector is harvest, the stage at which the commercial part of the plant is separated. Timely harvesting minimizes post-harvest losses, preserves product quality, and optimizes production processes. Globally, a substantial amount of food is wasted, impacting food security and natural resources. To address this problem, an Adaptive Neuro-Fuzzy Inference System was developed to predict timely harvesting in crops. Stevia, a native plant from Brazil and Paraguay, with an annual production of 100,000 to 200,000 tons and a market of 400 million dollars, is the focus of this study. The system considers soil pH, Brix Degrees, and leaf colorimetry as inputs. The output is binary: 1 indicates timely harvest and 0 indicates no timely harvest. To assess its performance, Leave-One-Out Cross-Validation was used, obtaining an <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>r</mi><mn>2</mn></msup></semantics></math></inline-formula> of 0.99965 and an Absolute Residual Error of 0.00064305, demonstrating its accuracy and robustness. In addition, an interactive application that allows farmers to evaluate crop status and optimize decision-making was developed.

A. Butlers, R. Laiho, A. Lazdiņš et al.

<p>Drainage of organic soils is associated with increasing soil carbon dioxide (<span class="inline-formula">CO₂</span>) efflux, which is typically linked to losses in soil carbon (C) stock. In previous studies, drained organic forest soils have been reported as both <span class="inline-formula">CO₂</span> sinks and <span class="inline-formula">CO₂</span> sources depending on, e.g., soil nutrient and moisture regime. However, most of the earlier research was done in the boreal zone, and both the magnitude of <span class="inline-formula">CO₂</span> efflux and the impact of soil moisture regime on soil C stock are likely to vary across different climatic conditions and ecosystems, depending further on vegetation. A 2-year study was conducted in hemiboreal forest stands with nutrient-rich organic soil (including current and former peatlands) and a range of dominant tree species (black alder, birch, Norway spruce, Scots pine) in the Baltic states (Estonia (EE), Latvia (LV), Lithuania (LT)). In this study, we analyzed the <span class="inline-formula">CO₂</span> balance of organic soil in drained (19) and undrained (7) sites. To assess the <span class="inline-formula">CO₂</span> balance, soil respiration was measured along with the evaluation of <span class="inline-formula">CO₂</span> influx into the soil through aboveground (aGV) and belowground (bGV) litter. To characterize the sites and factors influencing the <span class="inline-formula">CO₂</span> fluxes, we analyzed soil temperature, soil water table level (WTL), and physical and chemical parameters of soil and soil water. Irrespective of drainage status, the soils functioned as both <span class="inline-formula">CO₂</span> sinks and <span class="inline-formula">CO₂</span> sources. On average, a close-to-neutral soil <span class="inline-formula">CO₂</span> balance (<span class="inline-formula">+0.45</span> <span class="inline-formula">±</span> <span class="inline-formula">0.50</span> <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M17" display="inline" overflow="scroll" dspmath="mathml"><mrow class="unit"><mi mathvariant="normal">t</mi><mspace width="0.125em" linebreak="nobreak"/><msub><mi mathvariant="normal">CO</mi><mn mathvariant="normal">2</mn></msub><mtext>-</mtext><mi mathvariant="normal">C</mi><mspace linebreak="nobreak" width="0.125em"/><msup><mi mathvariant="normal">ha</mi><mrow><mo>-</mo><mn mathvariant="normal">1</mn></mrow></msup><mspace linebreak="nobreak" width="0.125em"/><msup><mi mathvariant="normal">yr</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="84pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="dd568f418b995b2f996a388906c3c2dc"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-4627-2025-ie00001.svg" width="84pt" height="16pt" src="bg-22-4627-2025-ie00001.png"/></svg:svg></span></span>) was observed in drained sites dominated by black alder, birch, or Norway spruce, while drained Scots pine sites showed soil <span class="inline-formula">CO₂</span> removals with a mean rate of <span class="inline-formula">+2.77</span> <span class="inline-formula">±</span> <span class="inline-formula">0.36</span> <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M22" display="inline" overflow="scroll" dspmath="mathml"><mrow class="unit"><mi mathvariant="normal">t</mi><mspace width="0.125em" linebreak="nobreak"/><msub><mi mathvariant="normal">CO</mi><mn mathvariant="normal">2</mn></msub><mtext>-</mtext><mi mathvariant="normal">C</mi><mspace width="0.125em" linebreak="nobreak"/><msup><mi mathvariant="normal">ha</mi><mrow><mo>-</mo><mn mathvariant="normal">1</mn></mrow></msup><mspace linebreak="nobreak" width="0.125em"/><msup><mi mathvariant="normal">yr</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="84pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="540989c6a85c99644841b532af9e168b"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-4627-2025-ie00002.svg" width="84pt" height="16pt" src="bg-22-4627-2025-ie00002.png"/></svg:svg></span></span>. In undrained birch- and spruce-dominated sites, soil functioned as a mean <span class="inline-formula">CO₂</span> sink at <span class="inline-formula">+1.33</span> <span class="inline-formula">±</span> <span class="inline-formula">0.72</span> <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M27" display="inline" overflow="scroll" dspmath="mathml"><mrow class="unit"><mi mathvariant="normal">t</mi><mspace linebreak="nobreak" width="0.125em"/><msub><mi mathvariant="normal">CO</mi><mn mathvariant="normal">2</mn></msub><mtext>-</mtext><mi mathvariant="normal">C</mi><mspace width="0.125em" linebreak="nobreak"/><msup><mi mathvariant="normal">ha</mi><mrow><mo>-</mo><mn mathvariant="normal">1</mn></mrow></msup><mspace linebreak="nobreak" width="0.125em"/><msup><mi mathvariant="normal">yr</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="84pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="ccbc9935c7d7ad51defec09dd47ba659"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-4627-2025-ie00003.svg" width="84pt" height="16pt" src="bg-22-4627-2025-ie00003.png"/></svg:svg></span></span>, while the undrained black alder stands showed an uncertain <span class="inline-formula">CO₂</span> balance of <span class="inline-formula">+1.12</span> <span class="inline-formula">±</span> <span class="inline-formula">2.47</span> <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M32" display="inline" overflow="scroll" dspmath="mathml"><mrow class="unit"><mi mathvariant="normal">t</mi><mspace linebreak="nobreak" width="0.125em"/><msub><mi mathvariant="normal">CO</mi><mn mathvariant="normal">2</mn></msub><mtext>-</mtext><mi mathvariant="normal">C</mi><mspace width="0.125em" linebreak="nobreak"/><msup><mi mathvariant="normal">ha</mi><mrow><mo>-</mo><mn mathvariant="normal">1</mn></mrow></msup><mspace linebreak="nobreak" width="0.125em"/><msup><mi mathvariant="normal">yr</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="84pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="90b59eeeb063cf10c63ed34051b5138b"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-4627-2025-ie00004.svg" width="84pt" height="16pt" src="bg-22-4627-2025-ie00004.png"/></svg:svg></span></span>. Variation in the soil <span class="inline-formula">CO₂</span> balance was related to soil macronutrient concentrations and pH: forest types characterized by lower nutrient availability showed greater soil <span class="inline-formula">CO₂</span> sink. The reported soil <span class="inline-formula">CO₂</span> balance values may be used as regional emission factors (EFs).</p>

Yujiao Lyu, Pengxin Wang, Xueyuan Bai et al.

Accurate mapping of multiple soil properties is essential for enhancing soil quality and optimizing agricultural management practices. Given the complex interactions among soil properties, generating distribution maps for multiple soil properties provide richer informationto support agricultural decision-making. This study proposes an effective digital soil mapping (DSM) framework that integrates multisource data [PlanetScope imagery, uncrewedaerial vehicle (UAV) data] with feature selection methods and ensemble learning to predict key soil properties: soil organic carbon (SOC), total nitrogen, pH, available phosphorus, and available potassium. Results demonstrated that data integration markedly improved prediction accuracy. Multitemporal PlanetScope imagery outperformed UAV imagery, improving <inline-formula><tex-math notation="LaTeX">$\mathbf {R^{2}}$</tex-math></inline-formula> by around 0.20 and reducing its standard deviation by around 0.10. Integrating pedotransfer functions with DSM techniques enhanced SOC modeling (<inline-formula><tex-math notation="LaTeX">$\mathbf {R^{2}}$</tex-math></inline-formula> increased from 0.70 to 0.82), yielding an SOC map that better reflects the carbon&#x2013;nitrogen ratio and the underlying physical mechanisms. Among feature selection methods, the variable importance method outperformed genetic algorithms and the correlation-based methods, improving <inline-formula><tex-math notation="LaTeX">$\mathbf {R^{2}}$</tex-math></inline-formula> by 0.07&#x2013;0.24. A metamodel based on gradient boosting decision tree (GBDT) was developed to adaptively stack light gradient boosting machine (LightGBM), support vector regression (SVR), and random forest (RF). The LightGBM model achieved a 5&#x0025; reduction in normalized root-mean-square error compared to RF and SVR. The EM_GBDT model delivered the highest performance, with <inline-formula><tex-math notation="LaTeX">$\mathbf {R^{2}}$</tex-math></inline-formula> exceeding 0.75 and concordance correlation coefficient exceeding 0.80 for all soil properties. These results emphasize the capability of the proposed approach for field-scale DSM and provide valuable insights for supporting sustainable soil management and enhancing agricultural production.

Fani Lauermann, Y. Tsai, J. Eccles

Tommaso Franzini

The Feigin-Frenkel homomorphism underpinning the Wakimoto construction realises an affine Lie algebra at critical level in terms of the $βγ$-system of free fields. It was recently shown that much of the construction also goes through for double loop algebras. However, certain divergent sums appear. In this paper, we show that, suggestively, these sums vanish when one performs $ζ$-function regularisation.

Yanbing Chi, Chenchen Wei, Peiling Yang et al.

Reclaimed water (RW), as a reliable and renewable secondary water source, has become a crucial strategy for many countries to supplement agricultural water usage and alleviate water scarcity. However, despite the increasing use of RW, there has been limited research on the factors affecting soil nitrous oxide (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi mathvariant="normal">N</mi></mrow><mrow><mn>2</mn></mrow></msub><mi mathvariant="normal">O</mi></mrow></semantics></math></inline-formula>) emissions under RW irrigation. Understanding these factors is essential for guiding RW irrigation practices and controlling greenhouse gas emissions. This research, conducted from 2014 to 2015, includes field experiments designed to systematically assess the effects of soil chemistry properties and temperature on soil <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi mathvariant="normal">N</mi></mrow><mrow><mn>2</mn></mrow></msub><mi mathvariant="normal">O</mi></mrow></semantics></math></inline-formula> emissions under RW irrigation. Subsequent to these field studies, soil samples were collected for ¹⁵N isotope trials to examine the impact of RW on the soil <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi mathvariant="normal">N</mi></mrow><mrow><mn>2</mn></mrow></msub><mi mathvariant="normal">O</mi></mrow></semantics></math></inline-formula> production process, including autotrophic nitrification, heterotrophic nitrification, and denitrification. The results showed that RW irrigation influenced soil <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi mathvariant="normal">N</mi></mrow><mrow><mn>2</mn></mrow></msub><mi mathvariant="normal">O</mi></mrow></semantics></math></inline-formula> emissions by affecting soil pH, but not through changes in soil total nitrogen (TN) or soil organic carbon (SOC) content. Moreover, compared to groundwater (UW) irrigation, RW irrigation significantly reduced the temperature sensitivity of soil <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi mathvariant="normal">N</mi></mrow><mrow><mn>2</mn></mrow></msub><mi mathvariant="normal">O</mi></mrow></semantics></math></inline-formula> emissions. The ¹⁵N isotope labeling trial indicated that autotrophic nitrification was the primary pathway for soil <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi mathvariant="normal">N</mi></mrow><mrow><mn>2</mn></mrow></msub><mi mathvariant="normal">O</mi></mrow></semantics></math></inline-formula> production under RW irrigation, contributing 60.46%—significantly higher than that observed with UW irrigation. Primary treated sewage (PW) significantly increased soil <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi mathvariant="normal">N</mi></mrow><mrow><mn>2</mn></mrow></msub><mi mathvariant="normal">O</mi></mrow></semantics></math></inline-formula> emissions through the heterotrophic nitrification process compared to RW, with contributions rising from 11.31% to 13.23%. Additionally, RW, compared to UW, significantly increased the copy numbers of soil nitrification genes (ammonia-oxidizing archaea [<i>AOA-amoA</i>]) and denitrification genes (nitrite reductase [<i>nirK</i> and <i>nirS</i>]). Therefore, it is important to appropriately control the nitrification process and balance soil pH to manage soil <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi mathvariant="normal">N</mi></mrow><mrow><mn>2</mn></mrow></msub><mi mathvariant="normal">O</mi></mrow></semantics></math></inline-formula> emissions under RW irrigation.

Roberto Pérez-Garibay, Arturo Bueno-Tokunaga, Francisco Andrés Acosta-González et al.

The generation of electrocharged microbubbles is very important for several separation processes (e.g., water treatment, paper industry, and mineral processing). However, their rising terminal velocities are not fully understood. This work presents a laboratory study of the terminal velocity of single microbubbles (bubble diameter (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>D</mi></mrow><mrow><mi>b</mi></mrow></msub></mrow></semantics></math></inline-formula>) < 100 µm) rising in stagnant aqueous solutions with different pH levels (from 2 to 12) and reagent types (frother and collector; 30 ppm). The measurements were compared with the respective predicted velocities computed from the Stokes and Hadamard–Rybczynski models. It was found that the terminal velocities of electrocharged microbubbles were larger than the respective predictions from the Stokes equation. A regression equation was proposed to predict the terminal velocity as a function of the bubble diameter, which showed considerable dispersion depending on the type of reagent adsorbed on its surface, the concentration of these reagents, and the physical characteristics that the boundary layer acquires by modifying the zeta potential of the microbubbles; this effect has not yet been addressed in the literature.

S. Schmitt, G. Geldhof, David J. Purpura et al.

Mahir Hadzic

We review a series of recent results on global dynamic properties of radially symmetric self-gravitating compressible Euler flows, which naturally arise in the mathematical description of stars. We focus on the role of scaling invariances and how they interact with nonlinearities to generate imploding finite-time singularities as well as expanding star solutions, arising from smooth initial data. This review paper is based on joint works with Y. Guo, J. Jang, and M. Schrecker.

J. Meler, D. Litwicka, M. Zabłocka

<p>Measurements of light absorption coefficients by particles suspended in seawater (<span class="inline-formula"><i>a</i>_p(<i>λ</i>)</span>), by phytoplankton (<span class="inline-formula"><i>a</i>_ph(<i>λ</i>)</span>) and detritus (<span class="inline-formula"><i>a</i>_d(<i>λ</i>)</span>) were carried out in the southern Baltic Sea for the original seawater samples and four size fractions: pico-particles (0.2–2 <span class="inline-formula">µ</span>m), ultra-particles (2–5 <span class="inline-formula">µ</span>m), nano-particles (5–20 <span class="inline-formula">µ</span>m) and micro-particles (20–200 <span class="inline-formula">µ</span>m). Chlorophyll <span class="inline-formula"><i>a</i></span> (Chl <span class="inline-formula"><i>a</i></span>) and suspended particulate matter (SPM) concentrations were determined. The proportions of particles from the size classes in the <span class="inline-formula"><i>a</i>_p</span>(443), <span class="inline-formula"><i>a</i>_ph</span>(443) and <span class="inline-formula"><i>a</i>_d</span>(443) were determined. Pico- and ultra-particles had the largest contribution to the total particle absorption – an average of 38 % and 31 %. Particles of 5–20 <span class="inline-formula">µ</span>m accounted for approximately 20 % of <span class="inline-formula"><i>a</i>_p</span>(443) and <span class="inline-formula"><i>a</i>_ph</span>(443) and 29 % of <span class="inline-formula"><i>a</i>_d</span>(443). The contribution of particles <span class="inline-formula">&gt;</span> 20 <span class="inline-formula">µ</span>m averaged 5 %–10 %. In total SPM contribution of micro-particles averaged 17 %; nano-, ultra- and pico-particles averaged 29 %, 26 % and 27 %, respectively. In total Chl <span class="inline-formula"><i>a</i></span>, the proportions of pico- and ultra-particles averaged 35 % each, nano-particles 16 % and micro-particles 15 %. Temporal and spatial variability of particles contributions in size classes were observed.</p> <p>The average chlorophyll-specific and mass-specific light absorption coefficients, i.e., light absorption coefficients normalized to Chl <span class="inline-formula"><i>a</i></span> or SPM, were determined for all size fractions. The chlorophyll-specific coefficients <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M21" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi>a</mi><mi mathvariant="normal">p</mi><mrow><mo>(</mo><mi mathvariant="normal">Chl</mi><mspace linebreak="nobreak" width="0.25em"/><mi>a</mi><mo>)</mo></mrow></msubsup><mo>(</mo><mi mathvariant="italic">λ</mi><mo>)</mo></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="47pt" height="19pt" class="svg-formula" dspmath="mathimg" md5hash="40f35f4d95116e46bacae2d9b2f9ca08"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-20-2525-2023-ie00001.svg" width="47pt" height="19pt" src="bg-20-2525-2023-ie00001.png"/></svg:svg></span></span>, <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M22" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi>a</mi><mi mathvariant="normal">d</mi><mrow><mo>(</mo><mi mathvariant="normal">Chl</mi><mspace linebreak="nobreak" width="0.25em"/><mi>a</mi><mo>)</mo></mrow></msubsup><mo>(</mo><mi mathvariant="italic">λ</mi><mo>)</mo></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="47pt" height="19pt" class="svg-formula" dspmath="mathimg" md5hash="484463fc2a801e349f929b08d85ef511"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-20-2525-2023-ie00002.svg" width="47pt" height="19pt" src="bg-20-2525-2023-ie00002.png"/></svg:svg></span></span> and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M23" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi>a</mi><mi mathvariant="normal">ph</mi><mrow><mo>(</mo><mi mathvariant="normal">Chl</mi><mspace width="0.25em" linebreak="nobreak"/><mi>a</mi><mo>)</mo></mrow></msubsup><mo>(</mo><mi mathvariant="italic">λ</mi><mo>)</mo></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="47pt" height="20pt" class="svg-formula" dspmath="mathimg" md5hash="e3667091eb0219f241e71e8b8080ffd1"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-20-2525-2023-ie00003.svg" width="47pt" height="20pt" src="bg-20-2525-2023-ie00003.png"/></svg:svg></span></span>, <span class="inline-formula">±</span> standard deviations, do not allow clear separation of the individual fractions. For mass-specific coefficients, <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M25" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi>a</mi><mi mathvariant="normal">p</mi><mrow><mo>(</mo><mi mathvariant="normal">SPM</mi><mo>)</mo></mrow></msubsup><mo>(</mo><mi mathvariant="italic">λ</mi><mo>)</mo></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="45pt" height="19pt" class="svg-formula" dspmath="mathimg" md5hash="f8acb083a9476b35404aaac78f56bb61"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-20-2525-2023-ie00004.svg" width="45pt" height="19pt" src="bg-20-2525-2023-ie00004.png"/></svg:svg></span></span>, <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M26" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi>a</mi><mi mathvariant="normal">d</mi><mrow><mo>(</mo><mi mathvariant="normal">SPM</mi><mo>)</mo></mrow></msubsup><mo>(</mo><mi mathvariant="italic">λ</mi><mo>)</mo></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="45pt" height="19pt" class="svg-formula" dspmath="mathimg" md5hash="383605d95c5b0772ef10463a50702283"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-20-2525-2023-ie00005.svg" width="45pt" height="19pt" src="bg-20-2525-2023-ie00005.png"/></svg:svg></span></span> and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M27" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi>a</mi><mi mathvariant="normal">ph</mi><mrow><mo>(</mo><mi mathvariant="normal">SPM</mi><mo>)</mo></mrow></msubsup><mo>(</mo><mi mathvariant="italic">λ</mi><mo>)</mo></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="45pt" height="20pt" class="svg-formula" dspmath="mathimg" md5hash="db41c69c21e2757016982821893ccb5a"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-20-2525-2023-ie00006.svg" width="45pt" height="20pt" src="bg-20-2525-2023-ie00006.png"/></svg:svg></span></span>, it is possible to distinguish between large particles (20–200 <span class="inline-formula">µ</span>m) and small and medium particles (0.2–20 <span class="inline-formula">µ</span>m). These results will allow monitoring of suspended matter in size classes in optically complex waters of southern Baltic Sea.</p>

Nabaa S. Hadi, Huda H. Awadh

Recently, electro-kinetic (EK) remediation has become more popular as a novel method for removing chromium contamination from soil. This approach, however, is ineffective since it uses both cationic and anionic forms of chromium. In this study, a membrane-based technique was employed to increase the efficiency of the electro-kinetic removal of chromium. Chromium removal from polluted sludge was studied using four bench-scale experiments. Two of these experiments employed distilled water (EK<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>−</mo></mrow></semantics></math></inline-formula>1 and EK<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>−</mo></mrow></semantics></math></inline-formula>2 and membrane), whereas the other used acetic acid as the catholyte (EK<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>−</mo></mrow></semantics></math></inline-formula>3 and EK<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>−</mo></mrow></semantics></math></inline-formula>4 and membrane). The pH, total chromium, and fractionation of chromium in the sludge were measured after remediation. In the EK<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>−</mo></mrow></semantics></math></inline-formula>1, EK<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>−</mo></mrow></semantics></math></inline-formula>2 and membrane, and EK<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>−</mo></mrow></semantics></math></inline-formula>3 and EK<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>−</mo></mrow></semantics></math></inline-formula>4 and membrane trials, the average removal efficiencies of total chromium were 47.6%, 58.6%, and 74.4%, 79.6%, respectively. In contrast to the electro-kinetic remediation strategy, which left approximately 80% of the sludge neutral or alkaline after treatment, the membrane created acidic soil conditions throughout the sludge. For example, the high field intensity used in the membrane tests may have helped to facilitate chromium desorption, dissolution, and separation from the sludge and enhanced chromium mobility. The findings show that the membrane can improve the effectiveness of chromium removal from sludge when utilized in the EK remediation process.

Jennifer Fredricks, Tara Hofkens, Ming-Te Wang et al.

Jessica L Degol, Ming-Te Wang, Ya Zhang et al.

Erica L. Zippert, Bethany Rittle-Johnson

Abstract The goal of the current study is to develop a more complete understanding of the early home math environment, encompassing both numeracy and non-numeracy aspects of that environment. Parents of preschoolers (n = 63) were surveyed about their support of three components of early mathematics knowledge (i.e., numeracy, spatial, and pattern) as well as parents’ math-related beliefs about themselves and their children. Children were administered a broad math knowledge assessment which included a numeracy subscale, and individual measures of spatial and patterning skills in the fall (concurrently). Broad math knowledge was measured again in the spring of the preschool year. Parents indicated providing some support of early math development through numeracy, spatial, and patterning activities, with a stronger emphasis on numeracy than pattern and space. Parents’ child-specific ability beliefs were related to their numeracy, pattern, and broad math support, while their parent-specific ability beliefs were related to their spatial support. Parent support was rarely linked to child skills, except that numeracy support related to concurrent numeracy knowledge. Findings suggest that although parents do support a broad range of early math skills at home, parents tend to prioritize supporting early numeracy. Parents’ beliefs, especially about their child’s academic abilities, may influence components of the early home math environment, but future research is needed to better understand the relations between parent’s academic beliefs and the home math environment they create.

Xiaoxia Huang, Jie Zhang, Laura Hudson

Bethany Rittle-Johnson, Emily R. Fyfe, K. Hofer et al.

Mohammad Zulfa Ainun Niam, N. Auliya

This study aims to design, develop, and produce media products in the form of math mobile learning applications assisted by Adobe Animate software about lines and angles that meet the criteria of validity and media practicality so that the media can be applied in the learning process of lines and angles. The type of research used is research and development (Research and Development) which refers to the ADDIE model. The stages of developing this model include Analysis, Design, Development, Implementation, and Evaluation. 35 students of class VII MTs NU Raudlatus Shibyan were the subjects of this study. The data collection instruments were material expert validation sheets, media experts, and user response questionnaire sheets. The results of the development research are: (1) the results of the validation of material experts and media experts produce media validity in the "Very Valid" category and a validity score of 82.5 and 83.5 respectively; (2) the results of limited trials and the field gave results of "Very Practical" in the practicality category and the scores were respectively 85.2 and 85.43333333. Based on the validity and practicality scores of the media, the learning media in the form of a mobile learning math application using Adobe Animate software is feasible to be applied as a learning media for class VII mathematics about lines and angles.

M. Nugroho

Saat ini perkembangan ilmu pengetahuan dan teknologi semakin pesat dan tanpa batas. Perubahan pola pikir dan tingkah laku masyarakat merupakan dampak dari perkembangan ilmu pengetahuan dan teknologi tersebut atau yang saat ini dikenal dengan istilah society 5.0. Salah satu tantangan terbesar di era society 5.0 ini adalah berkurangnya peran aktif masyarakat dalam mengimplementasikan warisan budaya di Indonesia. Penulis dalam artikel ini menawarkan solusi inovasi media pembelajaran berupa sebuah aplikasi yaitu MC (Math with Culture) guna membantu siswa SMP dalam mengimplementasikan warisan budaya melalui pembelajaran matematika. Metode yang penulis gunakan yaitu Research and Development dengan model Analysis, Design, Development, Implementation, and Evaluation (ADDIE) dengan teknik analisis data secara kualitatif dan kuantitatif. Pada penelitian ini, didapatkan hasil bahwa aplikasi MC (Math with Culture) dikategorikan layak dipakai dalam pembelajaran mata pelajaran matematika. Kata Kunci: Society era 5.0; Budaya Indonesia, Aplikasi MC (Math with Culture). Abstract Nowadays, the development of science and technology is increasingly rapid and boundless. Changes in people's mindsets and behaviors are the impact of the development of science and technology or what is currently known as society 5.0. One of the biggest challenges in this era of society 5.0 is the reduced active role of the community in implementing cultural heritage in Indonesia. The author in this article offers an innovative learning media solution in the form of an application, namely MC (Math with Culture) to help junior high school students in implementing cultural heritage through mathematics learning. The method that the author uses is Research and Development with the (Analysis, Design, Development, Implementation, and Evaluation) ADDIE model with qualitative and quantitative data analysis techniques. In this study, the results were obtained that the MC (Math with Culture) application was categorized as feasible for use in learning mathematics subjects. Keywords: Society era 5.0; Indonesian Culture, MC (Math with Culture) Application.