Hasil untuk "math-ph"

C. Blair, R. P. Razza

S. Spencer, C. Steele, D. Quinn

Ming-Te Wang, Jennifer Fredricks, Feifei Ye et al.

Rik Koncel-Kedziorski, Subhro Roy, Aida Amini et al.

Recent work across several AI subdisciplines has focused on automatically solving math word problems. In this paper we introduce MAWPS, an online repository of Math Word Problems, to provide a unified testbed to evaluate different algorithms. MAWPS allows for the automatic construction of datasets with particular characteristics, providing tools for tuning the lexical and template overlap of a dataset as well as for filtering ungrammatical problems from web-sourced corpora. The online nature of this repository facilitates easy community contribution. At present, we have amassed 3,320 problems, including the full datasets used in several prominent works.

Zhiru Sun, Kui Xie, Lynley H. Anderman

Silke Luttenberger, Sigrid Wimmer, M. Paechter

Anxiety disorders are some of the most widespread mental health issues worldwide. In educational settings, individuals may suffer from specific forms of test and performance anxiety that are connected to a knowledge domain. Unquestionably, the most prominent of these is math anxiety. Math anxiety is a widespread problem for all ages across the globe. In the international assessments of the Programme for International Student Assessment (PISA) studies, a majority of adolescents report worry and tension in math classes and when doing math. To understand how math anxiety takes effect, it has to be regarded as a variable within an ensemble of interacting variables. There are antecedents that facilitate the development of math anxiety. They concern environmental factors such as teachers’ and parents’ attitudes toward their students’ and children’s ability in math, societal stereotypes (eg, on females’ math abilities), or personal factors such as traits or gender. These antecedents influence a number of variables that are important in learning processes. Math anxiety interacts with variables such as self-efficacy or motivation in math, which can intensify or counteract math anxiety. Outcomes of math anxiety concern not only performance in math-related situations, they can also have long-term effects that involve efficient (or not-so-efficient) learning as well as course and even vocational choices. How can math anxiety be counteracted? A first step lies in its correct diagnosis. Questionnaires for the assessment of math anxiety exist for all age groups, starting at primary education level. Help against math anxiety can be offered on different levels: by educational institutions, by teachers and a change in instructional approaches, by parents, or by the affected person. However, much more research is needed to develop effective measures against math anxiety that are tailored to an individual’s characteristics and needs.

J. Schneider, U. Riebesell, C. A. Moras et al.

<p>Ocean Alkalinity Enhancement (OAE) is a carbon dioxide removal strategy that aims to chemically sequester atmospheric CO<span class="inline-formula">₂</span> in the ocean while potentially alleviating localized effects of ocean acidification. Depending on the implementation approach, OAE can considerably alter seawater carbonate chemistry, resulting in temporarily reduced CO<span class="inline-formula">₂</span> partial pressure (<span class="inline-formula"><i>p</i></span>CO<span class="inline-formula">₂</span>) and elevated pH before re-equilibration with the atmosphere or mixing with unperturbed waters. To investigate the effects of OAE on biogeochemical processes and organisms under close-to-natural conditions, a large-scale mesocosm experiment was conducted in a temperate fjord ecosystem near Bergen, Norway, during late spring. A non-CO<span class="inline-formula">₂</span>-equilibrated OAE approach was chosen, simulating OAE with calcium- and silicate-based minerals. A gradient of five OAE levels was achieved by increasing total alkalinity (TA) by 0–600 <span class="inline-formula">µmol kg⁻¹</span>. The added TA remained relatively stable over the 47 d experiment and measured CO<span class="inline-formula">₂</span> gas exchange rates reached up to <span class="inline-formula">−15</span> mmol C m<span class="inline-formula">⁻²</span> d<span class="inline-formula">⁻¹</span>. We estimated that full equilibration (95 %) by air-sea gas exchange for a <span class="inline-formula">Δ</span>TA of 600 <span class="inline-formula">µmol kg⁻¹</span> would take <span class="inline-formula">∼1050</span> d. Furthermore, various mineral-type and/or <span class="inline-formula"><i>p</i></span>CO<span class="inline-formula">₂</span> <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M16" display="inline" overflow="scroll" dspmath="mathml"><mo>/</mo></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="c6f00d13d95b9183e3e2526db4298e27"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-23-137-2026-ie00001.svg" width="8pt" height="14pt" src="bg-23-137-2026-ie00001.png"/></svg:svg></span></span> pH effects were found. Coccolithophore calcification followed an optimum curve response along the <span class="inline-formula"><i>p</i></span>CO<span class="inline-formula">₂</span> gradient, consistent with findings from single-species laboratory cultures. In contrast, in-situ net community production (NCP) was higher in the silicate-based treatments, but was not modified by changes in <span class="inline-formula"><i>p</i></span>CO<span class="inline-formula">₂</span>. Zooplankton respiration, estimated from in-situ NCP and in-vitro NCP incubations, was lower for the silicate-based treatments and negatively correlated with <span class="inline-formula"><i>p</i></span>CO<span class="inline-formula">₂</span>. These complex findings suggest both direct and indirect effects of mineral type and OAE level and provide a valuable foundation for designing future OAE field trials. For a safe application of OAE, non-equilibrated alkalinity additions must balance efficiency and environmental impact.</p>

Takako Hoshiyama, Katsuhiro Nishinari

This study developed an approximation framework for GI/G/s queues with excluded volumes. Building on a discrete-time GI/G/1 framework that embeds the totally asymmetric simple exclusion process (TASEP) via matrix-geometric and aggregation methods, we derived a Sakasegawa-type approximation with an effective service rate <inline-formula> <tex-math notation="LaTeX">$\mu ^{\prime }=\mu p_{e}$ </tex-math></inline-formula> capturing the exclusion-induced delay. A gamma-based moment approximation links the Yanagisawa M/M/1 system with excluded volume (E-Queue) and the Alfa model for GI/G/1 queues by matching the first two moments of geometric and gamma distributions, yielding an internal density <inline-formula> <tex-math notation="LaTeX">$\rho _{\mathrm {mean}}$ </tex-math></inline-formula> that is fed back into the Sakasegawa formula as a response coefficient in a two-stage correction scheme. For numerical validation, we used the Alfa model and an aggregated Alfa model for GI/PH/s queues as references, and evaluated it over ranges of squared coefficients of variation, utilization, server counts, and service-time distributions. Within the validated region (<inline-formula> <tex-math notation="LaTeX">$c_{a}^{2}\ge 1$ </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">$c_{s}^{2}\le 1$ </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">$s\le 4$ </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">$h=0.1$ </tex-math></inline-formula>) (consistent with our previous study), the relative mean queue-length error is typically below 10%. Additional tests for exponential, Erlang, Weibull, Coxian-2, and static service times show full-range errors against the Alfa reference below 1% for light-tailed gamma-type cases and within a few percent for the more variable Coxian and Stacy cases, with mid-range traffic percentiles largely below 1%. We quantified the information loss from temporal discretization via Riemann sum approximations of gamma distributions and related it to the approximation error. Overall, the framework provides a data-assisted explicit approximation formula GI/G/s with a gamma-based two-stage correction and an error analysis that links the excluded volume.

M. A. Faraji, M. Askari-Sedeh, A. Zolfagharian et al.

Abstract The pH-sensitive hydrogels play a crucial role in applications such as soft robotics, drug delivery, and biomedical sensors, as they require precise control of swelling behaviors and stress distributions. Traditional experimental methods struggle to capture stress distributions due to technical limitations, while numerical approaches are often computationally intensive. This study presents a hybrid framework combining analytical modeling and machine learning (ML) to overcome these challenges. An analytical model is used to simulate transient swelling behaviors and stress distributions, and is confirmed to be viable through the comparison of the obtained simulation results with the existing experimental swelling data. The predictions from this model are used to train neural networks, including a two-step augmented architecture. The initial neural network predicts hydration values, which are then fed into a second network to predict stress distributions, effectively capturing nonlinear interdependencies. This approach achieves mean absolute errors (MAEs) as low as 0.031, with average errors of 1.9% for the radial stress and 2.55% for the hoop stress. This framework significantly enhances the predictive accuracy and reduces the computational complexity, offering actionable insights for optimizing hydrogel-based systems.

Ru-de Liu, Rui Zhen, Yi Ding et al.

Wiyao Maturin Awesso, Ibrahim Tchakala, Sophie Tingry et al.

This study evaluates the efficiency of sub-stoichiometric Ti₄O₇ titanium oxide anodes for the electrochemical degradation of glyphosate, a persistent herbicide classified as a probable carcinogen by the World Health Organization. After optimizing the process operating parameters (pH and current density), the mineralization efficiency and fate of degradation by-products of the treated solution were determined using a total organic carbon (TOC) analyzer and HPLC/MS, respectively. The results showed that at pH = 3, glyphosate degradation and mineralization are enhanced by the increased generation of hydroxyl radicals (^●OH) at the anode surface. A current density of 14 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mrow><mrow><mi>mA</mi><mo> </mo><mi>cm</mi></mrow></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup></mrow></semantics></math></inline-formula> enables complete glyphosate removal with 77.8% mineralization. Compared with boron-doped diamond (BDD), <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>Ti</mi></mrow><mn>4</mn></msub><msub><mi mathvariant="normal">O</mi><mn>7</mn></msub></mrow></semantics></math></inline-formula> shows close performance for treatment of a concentrated glyphosate solution (0.41 mM), obtained after nanofiltration of a synthetic ionic solution (0.1 mM glyphosate), carried out using an NF-270 membrane at a conversion rate (Y) of 80%. At 10<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mrow><mrow><mo> </mo><mi>mA</mi><mo> </mo><mi>cm</mi></mrow></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup></mrow></semantics></math></inline-formula> for 8 h, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>Ti</mi></mrow><mn>4</mn></msub><msub><mi mathvariant="normal">O</mi><mn>7</mn></msub></mrow></semantics></math></inline-formula> achieved 81.3% mineralization with an energy consumption of 6.09 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mrow><mrow><mi>kWh</mi><mo> </mo><mi mathvariant="normal">g</mi></mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></semantics></math></inline-formula> TOC, compared with 90.5% for BDD at 5.48 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mrow><mrow><mi>kWh</mi><mo> </mo><mi mathvariant="normal">g</mi></mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></semantics></math></inline-formula> TOC. Despite a slight yield gap, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>Ti</mi></mrow><mn>4</mn></msub><msub><mi mathvariant="normal">O</mi><mn>7</mn></msub></mrow></semantics></math></inline-formula> demonstrates notable efficiency under demanding conditions, suggesting its potential as a cost-effective alternative to BDD for glyphosate electro-oxidation.

Tahera Attarwala, Amin Boukari, Gulnihal Ozbay

Bivalves such as oysters rely on aragonite and calcite for shell formation via the biomineralization of calcium carbonate. Ocean acidification reduces carbonate ion availability, compromising shell growth and inducing dissolution under undersaturated conditions (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Ω</mi></mrow></semantics></math></inline-formula> < 1). This study assessed the aragonite and calcite saturation state (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Ω</mi></mrow></semantics></math></inline-formula>) as a proxy for evaluating habitat suitability for oyster aquaculture and restoration. Temperature, salinity, pH, and total alkalinity were monitored across multiple sites and used to calculate the aragonite and calcite saturation state via the Seacarb package. Calcium hardness and dissolved oxygen were also measured to evaluate compliance with hatchery water quality standards. Results indicated temporal and spatial fluctuations in saturation states, with frequent undersaturation during cooler months. Spearman correlation analyses demonstrated significant positive relationships between temperature and salinity (<i>p</i> = 0.46), between pH and aragonite saturation state (<i>p</i> = 0.72), and between alkalinity and aragonite saturation state (<i>p</i> = 0.51). These findings highlight the importance of carbonate chemistry variability and seasonal drivers in determining the suitability of sites for oyster cultivation and restoration under changing environmental conditions.

JIN Baodan, JIA Yusheng, DENG Weiling et al.

ObjectiveWaste-activated sludge (WAS) is a by-product of wastewater treatment plants (WWPTs), which seriously affects the operation of WWPTs and environmental safety. WAS is rich in protein, polysaccharides, and other macromolecular organic matter, but it also contains a significant amount of heavy metals and viruses. If not effectively treated, it causes severe secondary pollution in the environment and results in the waste of resources. The reduction, stabilization, harmlessness, and recycling of residual sludge represent the most critical challenges in sludge management. Anaerobic fermentation of sludge is the most common technology for treating and disposing of WAS, achieving the goals of sludge reduction and recycling. This study investigates the feasibility of nano zero-valent iron (nZVI) synergized with sodium percarbonate (SPC) to enhance the anaerobic fermentation performance of sludge using WAS from a municipal WWTP, and it also reveals the underlying fermentation mechanism. In addition, the optimal fermentation condition is identified.MethodsThe Fe²⁺ and Fe³⁺ derived from the hydrolysis of nZVI cooperated with the H₂O₂ produced by SPC to establish Fenton or Fenton-like systems. In addition, Fe³⁺ was reduced to Fe²⁺ by nZVI, establishing a cyclic reaction system that extended its action time within the fermentation system, enhancing the fermentation performance. In addition, Fe²⁺ and Fe³⁺ acted as catalysts to raise the decomposition of H₂O₂, resulting in the generation of many hydroxyl radicals (<inline-formula><alternatives><math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mi mathvariant="normal">H</mi><msubsup><mrow><mi mathvariant="normal">O</mi></mrow><mrow/><mrow><mo>·</mo></mrow></msubsup></math><graphic specific-use="big" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="alternativeImage/E93389D7-897D-4459-978A-5A2130802CF9-M003.jpg"><?fx-imagestate width="5.33400011" height="3.13266683"?></graphic><graphic specific-use="small" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="alternativeImage/E93389D7-897D-4459-978A-5A2130802CF9-M003c.jpg"><?fx-imagestate width="5.33400011" height="3.13266683"?></graphic></alternatives></inline-formula>, which oxidized and degraded organic matter and increased the sludge fermentation performance. In addition, Fe²⁺ reacted with PO<inline-formula><alternatives><math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><msubsup><mrow/><mrow><mn mathvariant="normal">4</mn></mrow><mrow><mn mathvariant="normal">3</mn><mo>‒</mo></mrow></msubsup></math><graphic specific-use="big" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="alternativeImage/E93389D7-897D-4459-978A-5A2130802CF9-M004.jpg"><?fx-imagestate width="2.11666679" height="3.55599999"?></graphic><graphic specific-use="small" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="alternativeImage/E93389D7-897D-4459-978A-5A2130802CF9-M004c.jpg"><?fx-imagestate width="2.11666679" height="3.55599999"?></graphic></alternatives></inline-formula>‒P to produce Fe₃(PO₄)₂•8H₂O precipitation, recovered PO<inline-formula><alternatives><math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M5"><msubsup><mrow/><mrow><mn mathvariant="normal">4</mn></mrow><mrow><mn mathvariant="normal">3</mn><mo>‒</mo></mrow></msubsup></math><graphic specific-use="big" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="alternativeImage/E93389D7-897D-4459-978A-5A2130802CF9-M004.jpg"><?fx-imagestate width="2.11666679" height="3.55599999"?></graphic><graphic specific-use="small" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="alternativeImage/E93389D7-897D-4459-978A-5A2130802CF9-M004c.jpg"><?fx-imagestate width="2.11666679" height="3.55599999"?></graphic></alternatives></inline-formula>‒P from the fermentation system, and evaluated the phosphorus removal performance of the SPC-enhanced nZVI fermentation system. Therefore, the fermentation mechanism was studied through batch experiments. A 2.5 L plexiglass reactor was used, and a magnetic stirrer was employed to maintain uniform stirring speed. The reaction temperature was room temperature (20~25 ℃), and the pH was not adjusted. A volume of 2.0 L of concentrated sludge was added to the F0~F3 reactors. The optimal dosage of SPC was determined to be 0.2 g SPC/g SS. Thus, the dosage of additives was set as follows: F0 (0.2 g SPC/g SS), F1 (0.2 g SPC/g SS + 10 mg nZVI/g SS), F2 (0.2 g SPC/g SS + 20 mg nZVI/g SS), and F3 (0.2 g SPC/g SS + 30 mg nZVI/g SS). In order to explore the influence of nZVI and SPC on the hydrolysis and acidification processes of the entire anaerobic fermentation system, the experiment involved a one-time addition of nZVI and SPC to the fermentation system without subsequent supplementation.Results and DiscussionsThe results showed that nZVI synergized with SPC has a significant effect on the hydrolytic acidification performance of the WAS anaerobic fermentation system. The protein concentration first increased and then decreased with nZVI addition, while polysaccharides increased with nZVI addition. The maximum concentrations reached 314.43 mg COD/L for protein and 140.14 mg COD/L for polysaccharides, respectively. This demonstrated that the Fenton system or Fenton-like system can facilitate the degradation of macromolecular organic matter. The short-chain fatty acids (SCFAs) concentrations first increased and then decreased with nZVI, with the maximum SCFAs observed in the F3 fermentation system at 1214.24 mg COD/L. The percentage of acetic acid content in the F3 fermentation system was also the highest, at 61.49%. These findings indicated that nZVI combined with SPC enhances the acidification performance of the fermentation system. Compared to the other three fermentation systems, the hydrolysis products of nZVI, Fe²⁺can react with PO<inline-formula><alternatives><math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M6"><msubsup><mrow/><mrow><mn mathvariant="normal">4</mn></mrow><mrow><mn mathvariant="normal">3</mn><mo>‒</mo></mrow></msubsup></math><graphic specific-use="big" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="alternativeImage/E93389D7-897D-4459-978A-5A2130802CF9-M004.jpg"><?fx-imagestate width="2.11666679" height="3.55599999"?></graphic><graphic specific-use="small" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="alternativeImage/E93389D7-897D-4459-978A-5A2130802CF9-M004c.jpg"><?fx-imagestate width="2.11666679" height="3.55599999"?></graphic></alternatives></inline-formula>‒P to form ferrous phosphate Fe₃(PO₄)₂ precipitate, resulting in a marked decrease in PO<inline-formula><alternatives><math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M7"><msubsup><mrow/><mrow><mn mathvariant="normal">4</mn></mrow><mrow><mn mathvariant="normal">3</mn><mo>‒</mo></mrow></msubsup></math><graphic specific-use="big" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="alternativeImage/E93389D7-897D-4459-978A-5A2130802CF9-M004.jpg"><?fx-imagestate width="2.11666679" height="3.55599999"?></graphic><graphic specific-use="small" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="alternativeImage/E93389D7-897D-4459-978A-5A2130802CF9-M004c.jpg"><?fx-imagestate width="2.11666679" height="3.55599999"?></graphic></alternatives></inline-formula>‒P concentration. The lower PO<inline-formula><alternatives><math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M8"><msubsup><mrow/><mrow><mn mathvariant="normal">4</mn></mrow><mrow><mn mathvariant="normal">3</mn><mo>‒</mo></mrow></msubsup></math><graphic specific-use="big" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="alternativeImage/E93389D7-897D-4459-978A-5A2130802CF9-M004.jpg"><?fx-imagestate width="2.11666679" height="3.55599999"?></graphic><graphic specific-use="small" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="alternativeImage/E93389D7-897D-4459-978A-5A2130802CF9-M004c.jpg"><?fx-imagestate width="2.11666679" height="3.55599999"?></graphic></alternatives></inline-formula>‒P concentration also indicated an improvement in the fermentation conditions. nZVI has a remarkable influence on biological enzymes in the synergized fermentation system, where the protease activity first increased and then declined, with the highest protease activity found in the F1 fermentation system (0.2 g SPC/g SS + 10 mg nZVI/g SS). However, the activities of α-glucosidase, acetic acid kinase, butyric acid kinase, dehydrogenase, and superoxide dismutase increased with nZVI addition. In contrast, the activities of ALP and ACP decreased with the increase in nZVI concentration. This indicated that nZVI combined with SPC enhances the oxidation performance of the fermentation system, and the higher oxidation level reduces enzyme activity. At the same time, the nZVI synergized SPC sludge fermentation system raises the enrichment of microbial functions, including <italic>Firmicutes</italic>, <italic>Bacteroidota</italic>, <italic>Proteobacteria</italic>, <italic>Actinobacteriota</italic>, <italic>Chloroflexi</italic>, and other bacteria such as <italic>Proteiniclasticum</italic>, <italic>Christensenellaceae_R-7</italic>, <italic>Petrimonas</italic>, and <italic>Macellibacteroides</italic>, which ensure effective hydrolysis and acidification performance and efficiently achieve SCFAs accumulation.ConclusionsThe results showed that the cooperation of nZVI with SPC significantly improved the anaerobic fermentation performance of WAS. This collaboration effectively accelerated the degradation of macromolecular organic matter in the fermentation system, providing a readily available substrate to produce SCFAs, particularly acetic acid. In addition, nZVI, in conjunction with SPC, contributed to the removal of phosphorus from the fermentation system, facilitating the recovery of phosphorus as a ferrous phosphate precipitate. The enrichment of functional bacteria further ensured the efficient hydrolysis and acidification performance of the nZVI‒SPC collaborative sludge fermentation system. The F3 fermentation system, with 0.2 g SPC/g SS + 30 mg nZVI/g SS, represented the optimal fermentation condition. This finding provides a new perspective and theoretical foundation for expanding sludge treatment and disposal methods.

Vafa Ahmadi, Nabin Aryal

Optimal product synthesis in bioelectrochemical systems (BESs) requires a comprehensive understanding of the relationship between external voltage and microbial yield. While most studies assume constant growth yields or rely on empirical estimates, this study presents a novel thermodynamic model, linking anodic oxidation and cathodic carbon dioxide (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>C</mi><mi>O</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></semantics></math></inline-formula>) reduction to methane (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>C</mi><mi>H</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></semantics></math></inline-formula>) by growing microbial biofilm. Through integrating theoretical Gibbs free energy calculations, the model predicts electron and proton transfers for autotrophic methanogen and anode-respiring bacteria (ARB) growth, accounting for varying applied voltages and substrate concentrations. The findings identify an optimal applied cathodic potential of −0.3 V <i>vs</i>. the standard hydrogen electrode (SHE) for maximizing <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>C</mi><mi>H</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></semantics></math></inline-formula> production under standard conditions (pH 7, 25 °C, 1 atm) regardless of ohmic losses. The model bridges the stoichiometry of anodic and cathodic biofilms, addressing research gaps in simulating anodic and cathodic biofilm growth simultaneously. Additionally, sensitivity analyses reveal that lower substrate concentrations require more negative voltages than standard condition to stimulate microbial growth. The model was validated using experimental data, demonstrating reasonable predictions of biomass growth and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>C</mi><mi>H</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></semantics></math></inline-formula> yield under different operating voltages in a multi substrate system. The results show that higher voltage inputs increase biomass yield while reducing <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>C</mi><mi>H</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></semantics></math></inline-formula> output due to non-optimal voltage. This validated model provides a tool for optimizing BES performance to enhance <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>C</mi><mi>H</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></semantics></math></inline-formula> recovery and biofilm stability. These insights contribute to finding optimum voltage for the highest <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>C</mi><mi>H</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></semantics></math></inline-formula> production for energy efficient <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>C</mi><mi>O</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></semantics></math></inline-formula> reduction for scaling up BES technology.

Alana Foley, Julianne Herts, F. Borgonovi et al.

Elizabeth A. Gunderson, Daeun Park, Erin A. Maloney et al.

Apriliany Kartika Jani, Moersilah Moersilah

This research aims to produce a learning media product in the form of a practical guide for the 5E learning cycle on acid-base titration material using natural pH indicators based on green chemistry that is valid and practical. The type of research used is Research and Development (R&D) with the Borg and Gall model using a descriptive quantitative method. The study was conducted from November 2021 to August 2022 at SMA N 53 Jakarta with 91 student respondents, eight teachers, three subject matter and language experts, and three media experts. The practical guide is equipped with a barcode to facilitate students’ access to videos, additional materials, and evaluation questions. The research results show that the pH range of the Red Shoot leaf extract is 2-5 with a color change from pink to yellow and 6-14 with a color change from yellow to brick red. The feasibility test results of the practical guide by the experts showed an average percentage of 85% for subject matter and language experts and 88% for media experts. The reliability test from the experts was categorized as “Very Reliable” with a value of 0.93 for both subject matter and language experts and media experts. The student trial results showed an average of 80% on a small scale and 90% on a large scale. The teacher trial results showed an average of 95% on a small scale. The trial results conclude that the practical guide for the 5E learning cycle on acid-base titration material using natural pH indicators based on green chemistry has met the criteria of “Very Good” and is suitable as a learning media. The attractive, innovative, and creative acid-base titration learning can use this practical guide as learning media.

Huiyong Fan, Jianzhong Xu, Zhihui Cai et al.

G. Šilinskas, Eve Kikas

ABSTRACT The present study examined the longitudinal associations between children’s perceptions of parental involvement in math homework (control and support) and their math performance and motivation (task-persistent homework behavior and math self-concept). Children (n = 512) reported their perceptions concerning parental involvement in sixth-grade math homework. In grades 3 and 6, children completed math tests, evaluated own math self-concept, and their mothers (n = 420) evaluated task persistence during homework. The results showed that low self-concept in math predicted increased parental control, which in turn related to low math performance, task persistence, and math self-concept. Second, perceived parental support was related to increased task persistence during homework. Finally, parental control was especially detrimental for boys’ task persistence and math self-concept.

Lei Wang, Yan Wang, Deng Cai et al.

Sequence-to-sequence (SEQ2SEQ) models have been successfully applied to automatic math word problem solving. Despite its simplicity, a drawback still remains: a math word problem can be correctly solved by more than one equations. This non-deterministic transduction harms the performance of maximum likelihood estimation. In this paper, by considering the uniqueness of expression tree, we propose an equation normalization method to normalize the duplicated equations. Moreover, we analyze the performance of three popular SEQ2SEQ models on the math word problem solving. We find that each model has its own specialty in solving problems, consequently an ensemble model is then proposed to combine their advantages. Experiments on dataset Math23K show that the ensemble model with equation normalization significantly outperforms the previous state-of-the-art methods.