Hasil untuk "math-ph"

Faridah Hanum, Salfauqi Nurman, Nurhayati et al.

Magnesium (Mg²⁺) ions require sensitive and selective detection due to their low concentrations and coexistence with similar ions in matrices. This study developed a potentiometric ISE using a new modified polyurethane membrane. The membrane’s negative surface charge facilitates selective interaction with Mg²⁺ ion. Optimal performance was obtained at 0.0061% (<i>w</i>/<i>w</i>) κ-carrageenan and 0.0006% (<i>w</i>/<i>w</i>) D2EHPA. The ISE exhibited a near-Nernstian response of 29.49 ± 0.01 mV/decade across a 10⁻⁹–10⁻⁴ M concentration range (<i>R²</i> = 0.992), with a detection limit of 1.25 × 10⁻¹⁰ M and a response time of 200 s. It remained stable in the pH range 6–8 for one month and demonstrated high selectivity over K⁺, Na⁺, and Ca²⁺ (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>K</mi></mrow><mrow><mi>i</mi><mi>j</mi></mrow></msub></mrow></semantics></math></inline-formula> < 1). The repeatability and reproducibility tests yielded standard deviations of 0.15 and 0.39, while recovery rates confirmed analytical reliability. The water contact angle analysis showed a reduction from ~80° to ~69° after membrane conditioning, indicating increased hydrophilicity and improved interfacial for ion diffusion. FTIR analysis confirmed successful modification by reduced O–H peak intensity, while XRD verified the amorphous structure. SEM revealed a dense top layer with concave morphology, favorable for minimizing leakage and ensuring efficient ion transport within the sensing system.

M. Guillermic, E. C. Krieger, E. C. Krieger et al.

<p>Coralline algae are a cosmopolitan group of important foundational species. The calcium carbonate they produce is increasingly being used as paleoenvironmental archives, as well as used to trace physiological responses of these important macroalgae to environmental change. In this context, evaluating the effect of oceanic change and photo-physiological parameters on geochemical proxies is critical, as such gaps may lead to erroneous paleoenvironmental reconstructions, misattributed drivers of calcification responses, and ultimately compromise conservation strategies. Here we address the impact of light (irradiance) on four species complexes of coralline red algae including two morphologies; geniculate (branching) and non-geniculate (encrusting). The four complexes up-regulated their <span class="inline-formula"><i>δ</i>¹¹B</span> derived pH<span class="inline-formula">_CF</span> relative to seawater by 0.6 to 0.8 pH unit. <span class="inline-formula"><i>δ</i>¹¹B</span> was not measurably affected by varying irradiance despite evidence of increasing photosynthesis. All complexes were able to maintain and elevate their pH<span class="inline-formula">_CF</span> relative to seawater for all treatments. Non-geniculate and geniculate complexes had distinct geochemical signatures of <span class="inline-formula"><i>δ</i>¹¹B</span>, <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M8" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi mathvariant="italic">δ</mi><msub><mrow class="chem"><msup><mi/><mn mathvariant="normal">13</mn></msup><mi mathvariant="normal">C</mi></mrow><mtext>mineral</mtext></msub></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="53pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="beb10e485aba230d7f2d8812b62ee16e"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-7669-2025-ie00001.svg" width="53pt" height="16pt" src="bg-22-7669-2025-ie00001.png"/></svg:svg></span></span> and trace elements. These differences in geochemical signatures indicate a variety of calcification mechanisms exist within coralline algae. We propose that different sources of dissolved inorganic carbon (DIC) are necessary to explain the observed <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M9" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi mathvariant="italic">δ</mi><msub><mrow class="chem"><msup><mi/><mn mathvariant="normal">13</mn></msup><mi mathvariant="normal">C</mi></mrow><mtext>mineral</mtext></msub></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="53pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="d0f4b724b30144769dbb7d7bae10ad2a"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-7669-2025-ie00002.svg" width="53pt" height="16pt" src="bg-22-7669-2025-ie00002.png"/></svg:svg></span></span>. As geniculate species have higher photosynthetic activity (i.e. gross photosynthesis), the DIC sources allocated to calcification might be limited due to greater <span class="inline-formula">CO₂</span> drawdown. This is supported by <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M11" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mi mathvariant="normal">B</mi><mo>/</mo><mi mathvariant="normal">Ca</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="30pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="c0f64f4592e8dde807a00769c8a08c80"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-7669-2025-ie00003.svg" width="30pt" height="14pt" src="bg-22-7669-2025-ie00003.png"/></svg:svg></span></span> and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M12" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mi mathvariant="normal">U</mi><mo>/</mo><mi mathvariant="normal">Ca</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="30pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="ad1503912e26592770e55071db30cf63"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-7669-2025-ie00004.svg" width="30pt" height="14pt" src="bg-22-7669-2025-ie00004.png"/></svg:svg></span></span> ratios suggesting modulation of carbonate chemistry and especially lower DIC<span class="inline-formula">_CF</span> in geniculate relative to non-geniculate complexes. DIC sources might come from direct <span class="inline-formula">CO₂</span> diffusion or better recycling of metabolic <span class="inline-formula">CO₂</span> which would explain the depleted <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M16" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi mathvariant="italic">δ</mi><msub><mrow class="chem"><msup><mi/><mn mathvariant="normal">13</mn></msup><mi mathvariant="normal">C</mi></mrow><mtext>mineral</mtext></msub></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="53pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="7b95f6b55e9179f4f6107320d9a8faf2"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-7669-2025-ie00005.svg" width="53pt" height="16pt" src="bg-22-7669-2025-ie00005.png"/></svg:svg></span></span>. This strategy likely arises from the different energy needs of the organisms, with non-geniculate using relatively more energy to support calcification. We suggest the different calcification mechanisms between morphologies are linked to different interactions between photosynthesis and carbon allocation. While photosynthesis can provide energy to geniculate complexes to maintain their metabolic needs, their calcification may be limited by DIC. In contrast, non-geniculate forms may benefit from more limited DIC drawdown due to lower photosynthetic activity, therefore maintaining higher internal DIC concentrations ultimately supporting faster calcification.</p>

Jamiu Mosebolatan Jabar, Olugbenga Oludayo Oluwasina, Odunayo Michael Agunloye et al.

Increasing awareness of protecting the environment from chemically aided naive ecosystem degradation has encouraged the use of eco-friendly (biomass) materials in industrial production globally. This study investigated the application of a natural wine-colored extract from Brazilian plume (BP) leaf, obtained through a microwave-assisted modern aqueous extraction technique, for toxic-free dyeing of mordant-functionalized cotton fabric. Dyeing of mordanted cotton fabric was optimized by varying dyeing parameters, such as dyeing contact time (10 to 90 min), pH (1 to 11), liquor ratio (1:5 to 1:30), and temperature (30 to 90 °C). UV-visible and Fourier transform infrared spectroscopic analyses confirmed that the chemical constituents of the extract were not altered by microwave radiation. The desired color strength (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>K</mi><mo>/</mo><mi>S</mi></mrow></semantics></math></inline-formula>) and dye-uptake (Q) were obtained at a dyeing time of 50 min, a pH of 7, a liquor ratio of 1:20, and a dyeing temperature of 60 °C. Varieties of elegant shades with desired colorfastness were developed through the involvement of less-toxic electrolyte and herbal mordants as functionalizing agents. BP extract is established as a potential sustainable and ecological colorant for textile industrial application.

Yanliang Zeng, Jun Jin, Chunfa Liao et al.

In this study, the catalytic air oxidation method was used to selectively form sodium antimonate from an antimony residue Na₂S-NaOH leaching solution of a high arsenic copper anode slime. In the first stage, the leaching process with Na₂S and NaOH media resulted in more than 98% leaching of antimony. The synergistic oxidation method was used to selectively separate antimony in the second stage. In this study, the oxidation rate of antimony was greater than 98% at the NaOH concentration of 50 g·L⁻¹ and a combined oxidation concentration of 0.75 g·L⁻¹ catechol + 0.75 g·L⁻¹ KMnO₄, under the air flow rates of 1.415 m³·min⁻¹ at 75 °C for 8 h. The pH of the crude sodium antimonate product was adjusted; subsequently, it was redissolved and precipitated to prepare refined sodium antimonate that meets the secondary product standard of China’s non-ferrous metal industry, which recommends an antimony recovery rate of >95.60%. After neutralisation, the liquid contains [As] < 0.10 g·L⁻¹, [Sb] = 0.16–0.38 g·L⁻¹, which can be reused in the composite leaching process. The apparent activation energy (Ea) of the catalytic oxidation reaction was 6.47 kJ·mol⁻¹; the results suggested that the reaction process was diffusion controlled. <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>−</mo><mstyle scriptlevel="0" displaystyle="false"><mfrac><mrow><mi>d</mi><mfenced open="[" close="]" separators="|"><mrow><mi>S</mi><mi>b</mi></mrow></mfenced></mrow><mrow><mi>d</mi><mi>t</mi></mrow></mfrac></mstyle><mo>=</mo><mn>8.86</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>5</mn></mrow></msup><mo>×</mo><msup><mrow><mi>e</mi></mrow><mrow><mstyle scriptlevel="0" displaystyle="false"><mfrac><mrow><mo>−</mo><mn>778.44</mn></mrow><mrow><mi>T</mi></mrow></mfrac></mstyle></mrow></msup><mo>×</mo><msup><mrow><mfenced open="[" close="]" separators="|"><mrow><mi>S</mi><mi>b</mi></mrow></mfenced></mrow><mrow><mn>0.4906</mn></mrow></msup><mo>×</mo><msup><mrow><mo>[</mo><mi>N</mi><mi>a</mi><mi>O</mi><mi>H</mi><mo>]</mo></mrow><mrow><mn>1.190</mn></mrow></msup></mrow></semantics></math></inline-formula>.

G. Le Guevel, G. Le Guevel, F. Minoletti et al.

<p>The coccolith sedimentary and micropalaeontological archive has fostered great interest in palaeoclimate applications. Indeed, the geochemistry of coccolith calcite has the potential to reconstruct both palaeo-<span class="inline-formula">CO₂</span> concentrations and palaeo-temperature of seawater. Studying coccolith geochemistry aims at better understanding the changes in the vital effect of coccoliths with changes in environmental parameters, especially the carbonate chemistry of seawater. To this aim, we need to deconvolve the biological imprint from the environmental signals recorded in the composition of coccoliths. We have undertaken culture experiments of four coccolithophore strains with various sizes and growth rates, grown under eight <span class="inline-formula">CO₂</span>/pH conditions typifying the <span class="inline-formula">CO₂</span> evolution of the Cenozoic era. We propose an assessment of the expression of the vital effects for <i>Emiliania huxleyi</i>, <i>Gephyrocapsa oceanica</i>, <i>Helicosphaera carteri</i> and <i>Coccolithus braarudii</i> with simultaneous changes in dissolved inorganic carbon (DIC) and pH in the medium resulting in variations in dissolved <span class="inline-formula">CO₂</span> (<span class="inline-formula">CO_2 aq</span>) availability to the cells. We have identified a distinct isotopic response of <i>C. braarudii</i> to <span class="inline-formula"><i>p</i></span><span class="inline-formula">CO₂</span> levels on both sides of the 600 ppmv (pH 7.89) condition. We propose that this discrepancy is the result of a modification of the proton efflux across the plasma membrane through voltage-dependent proton channels. We further show that as the <span class="inline-formula">CO₂</span> level rises and pH decreases (from 200 to 500 ppmv and from 8.29 to 7.96 pH units, respectively), a significant increase in <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M12" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi mathvariant="italic">δ</mi><msub><mrow class="chem"><msup><mi/><mn mathvariant="normal">13</mn></msup><mi mathvariant="normal">C</mi></mrow><mtext>coccolith</mtext></msub></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="58pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="ed793b00b07727321b91f02da8ec5393"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-2287-2025-ie00001.svg" width="58pt" height="16pt" src="bg-22-2287-2025-ie00001.png"/></svg:svg></span></span> of <i>C. braarudii</i> is expressed, along with a coeval decrease in <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M13" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi mathvariant="italic">δ</mi><msub><mrow class="chem"><msup><mi/><mn mathvariant="normal">13</mn></msup><mi mathvariant="normal">C</mi></mrow><mtext>org</mtext></msub></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="38pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="422bba6f2947eec7dd38c1f05f000d14"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-2287-2025-ie00002.svg" width="38pt" height="17pt" src="bg-22-2287-2025-ie00002.png"/></svg:svg></span></span>. The constant physiological parameters of <i>C. braarudii</i> (growth rate, particulate inorganic carbon (PIC) and particulate organic carbon (POC)) across the 200 to 500 ppmv interval support the idea that the change in <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M14" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi mathvariant="italic">δ</mi><msub><mrow class="chem"><msup><mi/><mn mathvariant="normal">13</mn></msup><mi mathvariant="normal">C</mi></mrow><mtext>coccolith</mtext></msub></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="58pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="c4eb374327484c2bb1b9d7cf8329e108"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-22-2287-2025-ie00003.svg" width="58pt" height="16pt" src="bg-22-2287-2025-ie00003.png"/></svg:svg></span></span> is the consequence of a lower fractionation between dissolved <span class="inline-formula">CO₂</span> and organic matter. Meanwhile, the small cells of <i>E. huxleyi</i> and <i>G. oceanica</i> are less carbon-limited and do not exhibit any change in their carbon vital effects with changes in carbonate chemistry of the environment across the whole <span class="inline-formula">CO₂</span> spectrum. Using this biogeochemical framework, we have established a calibration between <span class="inline-formula">CO_2 aq</span> concentration and the differential vital effect (<span class="inline-formula">Δ<i>δ</i>¹³C</span>) between isotopically invariant small <i>G. oceanica</i> and large coccoliths <i>C. braarudii</i>, whose vital effect is <span class="inline-formula">CO₂</span>-dependent at low <span class="inline-formula">CO₂</span>. The <span class="inline-formula">CO₂</span>–<span class="inline-formula">Δ<i>δ</i>¹³C</span> transfer equation allows palaeo-<span class="inline-formula"><i>p</i></span><span class="inline-formula">CO₂</span> reconstructions based on isotope changes explained by physiological processes, especially at low and medium <span class="inline-formula">CO₂</span> levels.</p>

Yang He, Chenhua Han, Hao Du et al.

The importance of phosphates has sparked researchers’ considerable interest in the electrochemical detection of phosphates within aqueous solutions in recent years. In this study, we present a novel all-solid-state phosphate ion-selective electrode (ISE) that integrates copper, copper nanoparticles, and copper phosphate. By modifying the copper substrate of the electrode with a copper nanoparticle film and creating a lamellar copper phosphate film through electrochemical treatment, we significantly enhanced the electrode’s electron transfer efficiency. This microstructure with large specific surface area markedly improved the electrode’s responsiveness to the targeted ions by accelerating the achievement of chemical equilibrium on the electrode surface, thereby boosting its sensitivity and stability. The newly developed electrode was capable of detecting phosphate ions in solutions with a pH range from 6 to 11 and performed optimally in neutral solutions at pH 7, following Nernst principle, with a detection limit of 1 × <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>6</mn></mrow></msup></mrow></semantics></math></inline-formula> M. The electrode exhibited a short response time of less than 10 s with significant reproducibility, stability, longevity—maintaining functionality for more than two months. It also displayed good selectivity as the electrochemical equilibrium was not influenced by up to 1 mM of potential competing species like <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mrow><mi>HCO</mi></mrow><mn>3</mn><mo>−</mo></msubsup></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mrow><mi>NO</mi></mrow><mn>3</mn><mo>−</mo></msubsup></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mrow><mi>Cl</mi></mrow><mo>−</mo></msup></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mrow><mi>SO</mi></mrow><mn>4</mn><mrow><mn>2</mn><mo>−</mo></mrow></msubsup></mrow></semantics></math></inline-formula>. We compared the detection results of current phosphate ion sensor and conventional determination methods for phosphate content in natural lake and aquaculture water samples, with a detection discrepancy of about 10% (RSD). Considering all feasible performance characteristics combined with its low cost, simple manufacture and portability, the sensor provides a new possibility for rapid, reliable, and long-term real-time in situ detection of phosphates.

Vishnuram Abhinav, Tejas R. Naik

This paper presents the development of a non-toxic and low-cost potassium ion sensor utilizing an Extended Gate Field-Effect Transistor (EGFET) configuration with all-solid-state electrodes fabricated on a printed circuit board (PCB) substrate. An Ag/AgCl-based pseudo-reference electrode (PRE) has been fabricated planar to a ion-selective membrane (ISM) coated on the gold solid-contact electrode (SCE). The PRE has shown <inline-formula> <tex-math notation="LaTeX">$\lt 1~mV/day$ </tex-math></inline-formula> drift potential, exhibiting exceptional stability and reproducibility. While the SCE has demonstrated a high sensitivity of <inline-formula> <tex-math notation="LaTeX">$49~mV/log[K^{+}]$ </tex-math></inline-formula>, covering a wide linear detection range from <inline-formula> <tex-math notation="LaTeX">$10^{-4}~M$ </tex-math></inline-formula> to <inline-formula> <tex-math notation="LaTeX">$1~M$ </tex-math></inline-formula> with a rapid response time of less than 10 seconds. The sensor has displayed minimal hysteresis (<inline-formula> <tex-math notation="LaTeX">$\lt 15~mV$ </tex-math></inline-formula>) and remained stable over a broad pH range (<inline-formula> <tex-math notation="LaTeX">$pH~4$ </tex-math></inline-formula> to <inline-formula> <tex-math notation="LaTeX">$pH~10$ </tex-math></inline-formula>). These uni-planar, all-solid-state electrodes along with off-the-shelf FET mitigate the requirement of additional wire bonding by utilizing a common PCB platform for sensing as well as circuitry area. Additionally, the PRE, SCE and the FET in the EGFET-configuration-based sensing system have exhibited a high current sensitivity of <inline-formula> <tex-math notation="LaTeX">$1.43~(\mu A)^{1/2}/log[K^{+}]$ </tex-math></inline-formula>. Our sensor presents a practical and reliable solution for soil nutrient measurement in precision agriculture, offering significant advantages over existing potassium sensors in terms of cost-effectiveness, sensitivity, stability, and environmental safety. The presented approach holds promise for optimizing agricultural productivity and minimizing environmental impact through efficient nutrient monitoring and smart irrigation and fertilization management systems.

Ramasamy Srinivasagan, Maged Mohammed, Ali Alzahrani

Fresh dates have a limited shelf life and are susceptible to spoilage, which can lead to economic losses for producers and suppliers. The problem of accurate shelf life estimation for fresh dates is essential for various stakeholders involved in the production, supply, and consumption of dates. Modified atmosphere packaging (MAP) is one of the essential methods that improves the quality and increases the shelf life of fresh dates by reducing the rate of ripening. Therefore, this study aims to apply fast and cost-effective non-destructive techniques based on machine learning (ML) to predict and estimate the shelf life of stored fresh date fruits under different conditions. Predicting and estimating the shelf life of stored date fruits is essential for scheduling them for consumption at the right time in the supply chain to benefit from the nutritional advantages of fresh dates. The study observed the physicochemical attributes of fresh date fruits, including moisture content, total soluble solids, sugar content, tannin content, pH, and firmness, during storage in a vacuum and MAP at 5 and 24 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mo>∘</mo></msup></semantics></math></inline-formula>C every 7 days to determine the shelf life using a non-destructive approach. TinyML-compatible regression models were employed to predict the stages of fruit development during the storage period. The decrease in the shelf life of the fruits begins when they transition from the Khalal stage to the Rutab stage, and the shelf life ends when they start to spoil or ripen to the Tamr stage. Low-cost Visible–Near–Infrared (VisNIR) spectral sensors (AS7265x—multi-spectral) were used to capture the internal physicochemical attributes of the fresh fruit. Regression models were employed for shelf life estimation. The findings indicated that vacuum and modified atmosphere packaging with 20% CO₂ and N balance efficiently increased the shelf life of the stored fresh fruit to 53 days and 44 days, respectively, when maintained at 5 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mo>∘</mo></msup></semantics></math></inline-formula>C. However, the shelf life decreased to 44 and 23 days when the vacuum and modified atmosphere packaging with 20% CO₂ and N balance were maintained at room temperature (24 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mo>∘</mo></msup></semantics></math></inline-formula>C). Edge Impulse supports the training and deployment of models on low-cost microcontrollers, which can be used to predict real-time estimations of the shelf life of fresh dates using TinyML sensors.

Ariel Espinoza-Jara, Igor Wilk, Javiera Aguirre et al.

The application of Artificial Neuronal Networks (ANN) offers better statistical accuracy in erosion-corrosion (E-C) predictions compared to the conventional linear regression based on Multifactorial Analysis (MFA). However, the limitations of ANN to require large training datasets and a high number of inputs pose a practical challenge in the field of E-C due to the scarcity of data. To address this challenge, a novel ANN method is proposed, structured to a small training dataset and trained with the aid of synthetic data to produce an E-C neural network (E-C NN), applied for the first time in the study of E-C wear synergy. In the process, transfer learning is applied by pre-training and fine-tuning the model. The initial dataset is created from experimental data produced in a slurry pot setup, exposing API 5L X65 steel to a turbulent copper tailing slurry. To the previously known E-C scenario for selected values of flow velocity, particle concentration, temperature, pH, and the content of the dissolved <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>C</mi><msup><mi>u</mi><mrow><mn>2</mn><mo>+</mo></mrow></msup></mrow></semantics></math></inline-formula>, new experimental data of stand-alone erosion and stand-alone corrosion is added. The prediction of wear loss by E-C NN considers individual parameters and their interactions. The main result is that E-C ANN provides better prediction than MFA as evaluated by a mean squared error (MSE) values of 2.5 and 3.7, respectively. The results are discussed in the context of the cross-effect between the proposed prediction model and the resulting estimation of relative contribution to E-C synergy, which is better predicted by the E-C NN. The E-C NN model is concluded to be a viable alternative to MFA, delivering similar prediction with better sensitivity to E-C synergy at shorter computation times when using the same experimental dataset.

Zijian Sun, Wei Shen, Weixuan Fang et al.

The top-geoherb “Rehe <i>Scutellaria baicalensis</i>” was naturally distributed on Yanshan Mountain in Chengde city, Hebei Province, China. Exploring the influences of parent materials on the quality of the top-geoherbs in terms of micronutrient elements is of great significance for the protection of origin and for optimizing replanting patterns of <i>Scutellaria baicalensis</i>. In this study, three habitats of <i>Scutellaria baicalensis</i> with contrasting geopedological conditions, i.e., naturally grown habitats (NGHs), artificial planting habitats (APHs), and biomimetic cultivation habitats (BCHs), are taken as objects to probe the influences of parent materials on the quality of <i>Scutellaria baicalensis</i> in terms of rare earth elements (REEs) by testing on REEs concentrations in the weathering profiles, rhizosphere soil and growing <i>Scutellaria baicalensis</i>, as well as their flavonoid compound contents. Hornblende-gneiss was the parent rock in NGHs, whose protolith was femic volcanic rock. Loess was the parent rock in APHs and BCHs. REEs were more abundant in hornblende-gneiss than loess, and therefore, soils developed in NGHs contained higher REE concentrations than those in APHs, which was lower than BCHs after REE-rich micro-fertilizers application. The coefficient of variation (CV) of REEs concentrations in the rhizosphere soils of hornblende-gneiss was higher than that in loess. It possibly was attributed to the complicated minerals compositions and various minerals’ grain sizes of hornblende-gneiss, resulting in the variety of weathering intensity involving eluviation, leaching, adsorption, etc., as well as weathering productions, dominated by clay minerals and Fe-(hydro)oxide, and ultimately the remarkable differences in the migrations, enrichments and fractionations within REEs. The biological absorption coefficients (BACs) of REEs for <i>Scutellaria baicalensis</i> decreased in the order of NGHs > APHs > BCHs. Roots of <i>Scutellaria baicalensis</i> contained similar <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">Σ</mi></semantics></math></inline-formula>REE in NGHs (2.02 mg·kg<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></semantics></math></inline-formula>) and BCHs (2.04 mg·kg<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></semantics></math></inline-formula>), which were higher than that in APHs (1.78 mg·kg<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></semantics></math></inline-formula>). Soils developed in hornblende-gneiss were characterized by lower clay fraction content and overall alkalinity with a pH value of 8.06. The absorption and utilization efficiency of REEs for <i>Scutellaria baicalensis</i> in NGHs was higher than in APHs and BCHs. Flavonoid compounds, effective constituents of <i>Scutelleria baicalensis</i>, showed more accumulations in NGHs than APHs and BCHs, implying their optimal quality of <i>Scutellaria baicalensis</i> in NGHs. Flavonoid compounds were remarkably correlated with REEs in the roots, suggesting the influence of REEs concentrations on the quality of <i>Scutellaria baicalensis</i>. It can be concluded that high REEs and micronutrient element concentrations of hornblende-gneiss favored the synthesis and accumulation of flavonoid compounds in <i>Scutellaria baicalensis</i> after the activation of endocytosis induced by REEs.

Jinfang Ma, Xue Zhou, Baiheng Xie et al.

<i>Gastrodia elata (G. elata)</i> Blume is widely used as a health product with significant economic, medicinal, and ecological values. Due to variations in the geographical origin, soil pH, and content of organic matter, the levels of physiologically active ingredient contents in <i>G. elata</i> from different origins may vary. Therefore, rapid methods for predicting the geographical origin and the contents of these ingredients are important for the market. This paper proposes a visible–near-infrared (Vis-NIR) spectroscopy technology combined with machine learning. A variety of machine learning models were benchmarked against a one-dimensional convolutional neural network (1D-CNN) in terms of accuracy. In the origin identification models, the 1D-CNN demonstrated excellent performance, with the F1 score being 1.0000, correctly identifying the 11 origins. In the quantitative models, the 1D-CNN outperformed the other three algorithms. For the prediction set of eight physiologically active ingredients, namely, GA, HA, PE, PB, PC, PA, GA + HA, and total, the <i>RMSEP</i> values were 0.2881, 0.0871, 0.3387, 0.2485, 0.0761, 0.7027, 0.3664, and 1.2965, respectively. The <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mrow><mi>R</mi></mrow><mrow><mi>p</mi></mrow><mrow><mn>2</mn></mrow></msubsup></mrow></semantics></math></inline-formula> values were 0.9278, 0.9321, 0.9433, 0.9094, 0.9454, 0.9282, 0.9173, and 0.9323, respectively. This study demonstrated that the 1D-CNN showed highly accurate non-linear descriptive capability. The proposed combinations of Vis-NIR spectroscopy with 1D-CNN models have significant potential in the quality evaluation of <i>G. elata</i>.

I. Bongartz, A. R. Conn, Nick Gould et al.

The purpose of this article is to discuss the scope and functionality of a versatile environment for testing small- and large-scale nonlinear optimization algorithms. Although many of these facilities were originally produced by the authors in conjunction with the software package LANCELOT, we believe that they will be useful in their own right and should be available to researchers for their development of optimization software. The tools can be obtained by anonymous ftp from a number of sources and may, in many cases, be installed automatically. The scope of a major collection of test problems written in the standard input format (SIF) used by the LANCELOT software package is described. Recognizing that most software was not written with the SIF in mind, we provide tools to assist in building an interface between this input format and other optimization packages. These tools provide a link between the SIF and a number of existing packages, including MINOS and OSL. Additionally, as each problem includes a specific classification that is designed to be useful in identifying particular classes of problems, facilities are provided to build and manage a database of this information. There is a Unix and C shell bias to many of the descriptions in the article, since, for the sake of simplicity, we do not illustrate everything in its fullest generality. We trust that the majority of potential users are sufficiently familiar with Unix that these examples will not lead to undue confusion.

Reuben Marc Swart, Hendrik Brink, Willie Nicol

The hydrolysis of lignocellulosic biomass opens an array of bioconversion possibilities for producing fuels and chemicals. Microbial fermentation is particularly suited to the conversion of sugar-rich hydrolysates into biochemicals. <i>Rhizopus oryzae</i> ATCC 20344 was employed to produce fumaric acid from glucose, xylose, and a synthetic lignocellulosic hydrolysate (glucose–xylose mixture) in batch and continuous fermentations. A novel immobilised biomass reactor was used to investigate the co-fermentation of xylose and glucose. Ideal medium conditions and a substrate feed strategy were then employed to optimise the production of fumaric acid. The batch fermentation of the synthetic hydrolysate at optimal conditions (urea feed rate <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0.625</mn></mrow></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">m</mi></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">g</mi></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">L</mi></semantics></math></inline-formula>⁻¹<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">h</mi></semantics></math></inline-formula>⁻¹ and pH 4) produced a fumaric acid yield of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0.439</mn></mrow></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">g</mi></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">g</mi></semantics></math></inline-formula>⁻¹. A specific substrate feed rate (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0.164</mn></mrow></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">g</mi></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">L</mi></semantics></math></inline-formula>⁻¹<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">h</mi></semantics></math></inline-formula>⁻¹) that negated ethanol production and selected for fumaric acid was determined. Using this feed rate in a continuous fermentation, a fumaric acid yield of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0.735</mn></mrow></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">g</mi></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">g</mi></semantics></math></inline-formula>⁻¹ was achieved; this was a <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>67.4</mn></mrow></semantics></math></inline-formula>% improvement. A metabolic analysis helped to determine a continuous synthetic lignocellulosic hydrolysate feed rate that selected for fumaric acid production while achieving the co-fermentation of glucose and xylose, thus avoiding the undesirable carbon catabolite repression. This work demonstrates the viability of fumaric acid production from lignocellulosic hydrolysate; the process developments discovered will pave the way for an industrially viable process.

Truong Xuan Vuong, Joseph Stephen, Tu Binh Minh et al.

Heavy metal contamination in agricultural land is an alarming issue in Vietnam. It is necessary to develop suitable remediation methods for environmental and farming purposes. The present study investigated the effectiveness of using peanut shell-derived biochar to remediate the two heavy metals Zn and Pb in laboratory soil assays following Tessier’s sequential extraction procedure. The concentration of heavy metals was analyzed using Inductively coupled plasma mass spectrometry (ICP-MS). This study also compared the effectiveness of the blend of biochar and apatite applied and the mere biochar amendment on the chemical fractions of Pb and Zn in the contaminated agricultural soil. Results have shown that the investigated soil was extremely polluted by Pb (3047.8 mg kg⁻¹) and Zn (2034.3 mg kg⁻¹). In addition, the pH, organic carbon, and electrical conductivity values of amended soil samples increased with the increase in the amendment’s ratios. The distribution of heavy metals in soil samples was in the descending order of carbonate fraction (F2) > residue fraction (F5) > exchangeable fraction (F1) > Fe/Mn oxide fraction (F3) > organic fraction (F4) for Pb and F5 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo> </mo><mo>≈</mo><mo> </mo></mrow></semantics></math></inline-formula> F2 > F1 > F3 > F4 for Zn. The peanut shell-derived biochar produced at 400 °C and 600 °C amended at a 10% ratio (PB4:10 and PB6:10) could significantly reduce the exchangeable fraction Zn from 424.82 mg kg⁻¹ to 277.69 mg kg⁻¹ and 302.89 mg kg⁻¹, respectively, and Pb from 495.77 mg kg⁻¹ to 234.55 mg kg⁻¹ and 275.15 mg kg⁻¹, respectively, and immobilize them in soil. Amending the biochar and apatite combination increased the soil pH, then produced a highly negative charge on the soil surface and facilitated Pb and Zn adsorption. This study shows that the amendment of biochar and biochar blended with apatite could stabilize Pb and Zn fractions, indicating the potential of these amendments to remediate Pb and Zn in contaminated soil.

G. Villena, J. Kleffmann

<p>A continuous source for the generation of pure HONO mixtures was developed and characterized, which is based on the Henry's law solubility of HONO in acidic aqueous solutions. With the help of a peristaltic pump, diluted nitrite and sulfuric acid solutions are mixed in a temperature-controlled stripping coil, which is operated with pure nitrogen or synthetic air at gas flow rates of 0.5–2 L min<span class="inline-formula">⁻¹</span>. Caused by the acidic conditions of the aqueous phase (pH <span class="inline-formula">≈</span> 2.5), nitrite is almost completely converted into HONO, which partitions to the gas phase limited by its known solubility in water. The source shows a fast time response of <span class="inline-formula">∼</span> 2 min (0 %–90 %) at higher concentrations and an excellent long-term stability (2<span class="inline-formula"><i>σ</i></span> noise <span class="inline-formula">&lt;</span> 1 %). The HONO emission of the source perfectly correlates with the nitrite concentration from the sub-ppb range up to 500 ppb. The rate of NO<span class="inline-formula">_<i>x</i></span> formation increases quadratically with the HONO concentration from non-detectable values at atmospheric relevant HONO concentrations reaching a NO<span class="inline-formula">_<i>x</i></span> content of 1.6 % at 500 ppb. A general equation based on Henry's law is developed, whereby the HONO concentration of the source can be calculated using measured experimental parameters, i.e. nitrite concentration, liquid flow rates, gas flow rate, pH of the solution, and temperature of the stripping coil. In the equation, the known Henry's law constant of HONO in sulfuric acid solutions is used. For the calculation of the effective Henry's law constant, the acid dissociation equilibrium of HONO <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M8" 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="fb147fccdcf98a9911cf3d26a8f6dc33"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="amt-15-627-2022-ie00001.svg" width="8pt" height="14pt" src="amt-15-627-2022-ie00001.png"/></svg:svg></span></span> nitrite is used as a variable to adjust the theoretical HONO concentration to the measured values. From the average of all experimental data the equilibrium of HONO <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M9" display="inline" overflow="scroll" dspmath="mathml"><mo>/</mo></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="8pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="880d1b22cfae9b4167ff115d05c6894c"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="amt-15-627-2022-ie00002.svg" width="8pt" height="14pt" src="amt-15-627-2022-ie00002.png"/></svg:svg></span></span> nitrite is described well by p<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M10" display="inline" overflow="scroll" dspmath="mathml"><mrow><msub><mi>K</mi><mi mathvariant="normal">a</mi></msub><mo>=</mo><mn mathvariant="normal">1021.53</mn><mo>/</mo><mi>T</mi><mo>-</mo><mn mathvariant="normal">0.449</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="118pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="0fd499b7d72d4db1dbb1ebab2eeddf65"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="amt-15-627-2022-ie00003.svg" width="118pt" height="14pt" src="amt-15-627-2022-ie00003.png"/></svg:svg></span></span>. The p<span class="inline-formula"><i>K</i>_a</span> of 3.0 <span class="inline-formula">±</span> 0.1 (1<span class="inline-formula"><i>σ</i></span>) at 25 <span class="inline-formula">^∘</span>C is in good agreement with the range of 2.8–3.28 published in former studies. A standard deviation between all measured and theoretical HONO concentrations of only <span class="inline-formula">±3.8</span> % was observed, and a conservative upper-limit accuracy of the HONO concentration of better 10 % is estimated. Thus, for the first time, a stable HONO source is developed which can be used for the absolute calibration of HONO instruments.</p>

Pedro Velho, Luís Marques, Eugénia A. Macedo

The growing human population, together with the inefficient use of natural resources, has been dramatically increasing the production of food waste, which poses serious economic, environmental, and social problems. Being so, it is necessary to increase the efficiency of food consumption so as to reduce its waste and to convert the remaining residues into societal benefits. Since this biowaste is rich in polyphenols and vitamins, it could become the feedstock for the production of important value-added compounds for the pharmaceutical (<i>e.g.</i>, food supplements) and cosmetic (<i>e.g.</i>, creams and shampoos) industries. In this work, partition studies of one polyphenol (epicatechin) and two B-complex vitamins (cyanocobalamin and nicotinic acid) were performed in biodegradable Aqueous Two-Phase Systems (ATPS) based on ethyl lactate and on organic salts (disodium tartrate, tripotassium citrate, and trisodium citrate) at 298.15 K and 0.1 MPa. The largest partition coefficient (<i>K</i>) and extraction efficiency (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>E</mi></semantics></math></inline-formula>) were obtained for vitamin B12 (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>K</mi><mo>=</mo><mn>78.56</mn></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>E</mi><mo>=</mo><mn>97.5</mn><mo>%</mo></mrow></semantics></math></inline-formula>) for the longest tie line <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced><mrow><mi>TLL</mi><mo>=</mo><mn>77.66</mn><mo>%</mo></mrow></mfenced></mrow></semantics></math></inline-formula> in the ATPS {ethyl lactate (1) + tripotassium citrate (2) + water (3)}. All the extractions were obtained with low biomolecule mass losses in quantification (<5%) and after a thorough study of pH influence in the UV–Vis absorbance spectra.

Andras Suto

Based on the paper "Fourier formula for quantum partition functions", arXiv:2106.10032 [math-ph], we show that in an infinite system of identical bosons interacting via a positive-type pair potential there is off-diagonal long-range order if and only if a nonzero fraction of the particles form infinite permutation cycles. In particular, there is Bose-Einstein condensation if and only if the diverging cycle lengths increase at least as fast with $N$, the number of particles, as $N^{2/d}$ in $d\geq 3$ dimensions. This extends a similar result known for the ideal Bose gas.

E. V. Belogub, V. V. Shilovskikh, K. A. Novoselov et al.

<p>Rhabdophane (Ce<span class="inline-formula">_0.34−0.43</span>Nd<span class="inline-formula">_0.13−0.14</span>Ca<span class="inline-formula">_0.06−0.29</span>La<span class="inline-formula">_0.08−0.11</span>Y<span class="inline-formula">_0.05−0.12</span>Pr<span class="inline-formula">_0.03−0.05</span>Sm<span class="inline-formula">_0.02−0.05</span>Gd<span class="inline-formula">_0.02−0.05</span>Fe<span class="inline-formula">_0−0.04</span>Dy<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M10" display="inline" overflow="scroll" dspmath="mathml"><mrow><msub><mi/><mrow><mn mathvariant="normal">0.00</mn><mo>-</mo><mn mathvariant="normal">0.01</mn></mrow></msub><msub><mo>)</mo><mrow><mn mathvariant="normal">0.97</mn><mo>-</mo><mn mathvariant="normal">1.01</mn></mrow></msub></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="80pt" height="13pt" class="svg-formula" dspmath="mathimg" md5hash="ab54368e4dabe72638a100874cc8de52"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="ejm-33-605-2021-ie00001.svg" width="80pt" height="13pt" src="ejm-33-605-2021-ie00001.png"/></svg:svg></span></span>((P<span class="inline-formula">_0.69−0.96</span>S<span class="inline-formula">_0.04−0.31)_1.00</span>O<span class="inline-formula">₄)</span>⚫H<span class="inline-formula">₂</span>O is found in a Fe<span class="inline-formula">³⁺</span>-oxyhydroxide nodule (brown iron ore) collected from the upper part of the oxidation profile of the Babaryk massive sulfide occurrence (South Urals, Russia) at a 1.6 m depth. The structural and microtextural features of rhabdophane are revealed by electron backscattered diffraction (EBSD); the chemical composition and distribution of the main components are determined on a scanning electron microscope (SEM) equipped with an energy-dispersive analyzer (EDA); the bulk contents of rare earth elements (REEs) and other elements in rock samples are analyzed using inductively coupled plasma mass spectrometry (ICP-MS). Rhabdophane forms spherulitic aggregates up to 35 <span class="inline-formula">µm</span> in size with a fine-grained core and radial radiant rims composed of prismatic crystals. The chaotically oriented aggregates of its particles of various sizes including prismatic crystals and spherulitic intergrowths also fill fractures up to 200 <span class="inline-formula">µm</span> long and 20–30 <span class="inline-formula">µm</span> thick in goethite. The zonal radial radiant structure of the rhabdophane aggregates and their occurrence in fractures of goethite unambiguously indicate the authigenic origin of rhabdophane. The chemically heterogeneous rhabdophane grains always contain Y, Ca and S and rarely Fe and Sr and are Th- or U-free. Contrasting zonation of Ca, S and Y contents is characteristic of spherulites. The band contrast of the EBSD patterns shows a good crystallinity of prismatic crystals regardless of the chemical composition even for Ca–S-rich zones. On the other hand, the Ca- and S-rich fine-grained centers of the spherulites do not yield any distinguishable diffraction patterns. There is a strong negative correlation in pairs (Ca<span class="inline-formula">+</span>Sr)–P and (REEs<span class="inline-formula">+</span>Y)–S and a positive correlation in pairs (Ca<span class="inline-formula">+</span>Sr)–S and (REEs<span class="inline-formula">+</span>Y)–P, which indicates the isomorphism according to the scheme (REEs<span class="inline-formula">+</span>Y)<span class="inline-formula">³⁺</span> <span class="inline-formula">+</span> (PO<span class="inline-formula">₄)³⁻</span> <span class="inline-formula">↔</span> (Ca<span class="inline-formula">+</span>Sr)<span class="inline-formula">²⁺</span> <span class="inline-formula">+</span> (SO<span class="inline-formula">₄)²⁻</span>. Thus, the chemical composition of rhabdophane does not completely correspond to the rhabdophane–tristramite/brockite series because of the absence of tetravalent U or Th. In contrast to similar samples from the deeper part of the oxidation zone, the brown iron ore with rhabdophane is enriched in light rare earth elements (LREEs) and P. The REEs were probably sourced from ore-bearing volcanomictic rocks, while P could also have been derived from the soil. The enrichment in REEs and P and the formation of rhabdophane are related to the alternation of dry and wet periods, the P input, and sorption–desorption of REEs from Fe<span class="inline-formula">³⁺</span> oxyhydroxides and/or clay minerals due to pH changes and variable composition of pore water.</p>

Bharathi Raju, R. Kumar, Samiappan Dhanalakshmi et al.

Adverse effects of wastewater on the hygiene of human and circumstances is a major issue in society. Appropriate refining systems with high efficiency is required to treat the wastewater. Sewage treatment plant plays a major and important role in conserving incredible nature of the environment. Microbiologically Induced Corrosion (MIC) is an important phenomenon in sewage structures which causes the deterioration of infrastructures. Huge capital has been spent and efforts have been made on wastewater treatment infrastructure to increase operating efficiency and reliability of compliance. The investments in reimbursement and maintenance of sewer structures upsurge with an increase in the rate of MIC. The focus of this review is to describe MIC in sewer structure and the factors influencing the corrosion such as the generation of Sulfuric acid (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>H</mi><mn>2</mn></msub><mi>S</mi><msub><mi>O</mi><mn>4</mn></msub></mrow></semantics></math></inline-formula>), Relative Humidity (RH), pH of the concrete structure and temperature. Modern developments in the design of Fiber Optical Sensors (FOSs) for observing the parameters including pH, Hydrogen Sulfide (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>H</mi><mn>2</mn></msub><mi>S</mi></mrow></semantics></math></inline-formula>), RH and temperature will be discussed.

Renukaradhya K. Math, D. Kambiranda, H. Yun et al.

ABSTRACT The Cel genes from Bacillus licheniformis MSB03 were cloned and expressed to investigate binding ability on clay minerals and sea sand at pH ranging 3 to 9. FTIR analysis has been done to characterize bound enzymes on clay minerals. Subsequent, surveying of NCBI database for extracellular enzymes of soil bacteria was carried out. Among the five cloned Cel enzymes assayed for binding to clay minerals, only Cel5H enzyme had the binding ability. Enzyme Cel5H exhibited highest binding to montmorillonite followed by kaolinite and sea sand. Interestingly, Cel5H had higher pI value of 9.24 than other proteins (5.2–5.7). Cel5H binding to montmorillonite was shown to be negatively affected below pH 3 and above pH 9. Infrared absorption spectra of the Cel5H-montmorillonite complexes showed distinct peaks for clay minerals and bound proteins. Furthermore, database survey of soil bacterial extracellular enzymes revealed that Bacillus species enzymes had higher pI than other soil bacterial enzymes. Graphical abstract Binding of Cel5H enzyme on clay minerals.