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Call For Papers for the SOFC-XIX Meeting, Stockholm, Sweden, July 13–18, 2025 [ABSTRACT FROM AUTHOR]

Background : The incorporation of industrial wastes, such as wood ash and paper sludge, as soil amendments is vital for both environmental sustainability and agroecosystem productivity. Herein, we evaluated the effects of wood ash and paper sludge alone and in combination with biochar on the physicochemical properties and heavy metal leaching risks in podzolic soils. Methods : The treatments included limestone (control), wood ash, paper sludge, wood ash+paper sludge, limestone+biochar, wood ash+biochar, paper sludge+biochar and wood ash+paper sludge+biochar, arranged in a 4 × 2 factorial design with three replicates. The Hydrus-1D model was employed to simulate the water movement under these soil amendments using leaching colums. Results : Overall, wood ash, paper sludge and biochar application significantly increased the pH of amended soil compared to control. Paper sludge amended treatments alone or in combination with biochar significantly decreased bulk density (8%–17%) and increased the total porosity (14%–25%). While biochar addition to wood ash and paper sludge significantly reduced the concentrations of Cd (by 6.42%), Co (by 10.95%), Cu (by 11.76%), Pb (by 30%) and Ni (by 3.75%) in the collected leachates. The treatment paper sludge + biochar was found to be the most effective treatment to retain the heavy metals, with maximum plant available water (0.28 cm ^3 cm ^−3 ) and field capacity (0.36 cm ^3 cm ^−3 ) compared to control treatment. The predictions from Hydrus-1D showed that paper mill wastes with biochar has a significant potential to increase the volumetric moisture contents of amended podzolic soil, with the simulated leaching times and saturation levels closely aligning with the measured values. Conclusion : paper sludge + biochar treatment showed improved soil physicochemical properties and displayed lower heavy metals than allowed limits to be used in soil. Further, experiments are needed to assess the effects of papermill waste products on podzolic soil properties under variable field conditions.

Paper and pencil have shown wide applicability in the area of flexible electronics. Devices based on paper and pencil offer distinctive advantages, including rapid, straightforward, and cost-effective fabrication, as well as recyclability and eco-friendly characteristics. There are several concepts that have been demonstrated using paper and pencil including thermoelectric, strain gauges, capacitive sensors, and biomedical devices. This review article summarizes state of art of pencil-based thermoelectric devices on paper and their future potential.

Climate change mitigation by increased paper recycling can alleviate the two-sided pressure on the Swedish forest sector: supplying growing demands for wood-based products and increasing the forest carbon sink. This study assesses two scenarios for making use of a reduced demand for primary pulp resulting from an increased paper recycling rate in Sweden, from the present 72% to 78%. A Conservation scenario uses the saved primary pulp to reduce pulplog harvests so as to increase the forest carbon sink concomitant with constant overall wood product supply. In contrast, a Substitution scenario uses the saved primary pulp to produce man-made cellulosic fibers (MMCF) from dissolving pulp replacing cotton fiber, implying increased overall wood product supply. Our results suggest that utilizing efficiency gains in paper recycling to reduce pulplog harvests is better from a climate change mitigation perspective than producing additional MMCF to substitute cotton fiber. This conclusion holds even when assuming the use of by-products from dissolving pulp making and an indirect increase in MMCF availability. Hence, unless joint improvements across the value chain materialize, the best climate change mitigation option from increased paper recycling in Sweden would seemingly be to reduce fellings rather than producing additional MMCF.

We study a three-species cyclic model whose organisms are vulnerable to contamination with an infectious disease which propagates person-to-person. We consider that individuals of one species perform a self-preservation strategy by reducing the mobility rate to minimise infection risk whenever an epidemic outbreak reaches the neighbourhood. Running stochastic simulations, we quantify the changes in spatial patterns induced by unevenness in the cyclic game introduced by the mobility restriction strategy of organisms of one out of the species. Our findings show that variations in disease virulence impact the benefits of dispersal limitation reaction, with the relative reduction of the organisms’ infection risk accentuating in surges of less contagious or deadlier diseases. The effectiveness of the mobility restriction tactic depends on the deceleration level and the fraction of infected neighbours which is considered too dangerous, thus triggering the defensive strategy. If each organism promptly reacts to the arrival of the first viral vectors in its surroundings with strict mobility reduction, contamination risk decreases significantly. Our conclusions may help biologists understand the impact of defensive strategies in ecosystems during an epidemic.

Call For Papers for the 247th ECS Meeting, Montreal, Canada, May 18-22, 2025 [ABSTRACT FROM AUTHOR]

A crucial yet challenging task in galaxy evolution studies is the identification of distant merging galaxies, a task that suffers from a variety of issues ranging from telescope sensitivities and limitations to the inherently chaotic morphologies of young galaxies. In this paper, we use random forests and convolutional neural networks to identify high-redshift JWST Cosmic Evolution Early Release Science Survey (CEERS) galaxy mergers. We train these algorithms on simulated 3 < z < 5 CEERS galaxies created from the IllustrisTNG subhalo morphologies and the Santa Cruz SAM light cone. We apply our models to observed CEERS galaxies at 3 < z < 5. We find that our models correctly classify ∼60%–70% of simulated merging and nonmerging galaxies; better performance on the merger class comes at the expense of misclassifying more nonmergers. We could achieve more accurate classifications, as well as test for a dependency on physical parameters such as gas fraction, mass ratio, and relative orbits, by curating larger training sets. When applied to real CEERS galaxies using visual classifications as ground truth, the random forests correctly classified 40%–60% of mergers and nonmergers at 3 < z < 4 but tended to classify most objects as nonmergers at 4 < z < 5 (misclassifying ∼70% of visually classified mergers). On the other hand, the CNNs tended to classify most objects as mergers across all redshifts (misclassifying 80%–90% of visually classified nonmergers). We investigate what features the models find most useful, as well as the characteristics of false positives and false negatives, and also calculate merger rates derived from the identifications made by the models.

Daphne bholua Buch. -Ham. ex D. Don (Thymelaeaceae) is a woody shrub native to the temperate forests of the Himalaya. Since the 12th century, the bark of D. bholua has been used as a raw material for handmade paper in Nepal, and employed for value-added products, including government documents, and religious texts. However, unsustainable commercial harvesting now threatens this centuries-old artisanal tradition. To inform and improve the conservation of this important species, we evaluated its habitat characteristics, size class distribution, and regeneration status along an elevation gradient (1900–2500 m) in Madane Mountain, central Nepal. We established 108 plots (5 m× 5 m) at three sites, each with three canopy types: closed, semi-closed, and open. We analyzed habitat characteristics, considering variations in physical and topographic variables and patterns of associated species in different elevation sites. D. bholua exhibited the highest mean density at higher elevations with minimal disturbance, whereas the lowest elevation site, experienced greater human disturbance, with the lowest density. Furthermore, the population structure displayed a ‘reverse J-shaped’ curve, suggesting favorable conditions for natural recruitment and regeneration. Our research findings also indicate that D. bholua populations thrive in semi-closed forest canopies, particularly when associated with Rhododendron arboreum , Quercus semecarpifolia , and Sarcococca coriacea. The outcomes may hold significant value for policymakers, conservationists, harvesters, paper manufacturers, and regulatory bodies aiding in development of environmentally sound conservation programs tailored to various elevations. Our key recommendation may appear surprising: we advise establishing a small, meticulously managed hand papermaking industry in the villages linked to Madane and nearby areas. This initiative would generate supplemental income and produce a culturally valuable and economically marketable product.

Climate changes may affect ecosystems destabilising relationships among species. We investigate the spatial rock-paper-scissors models with a regional unevenness that reduces the selection capacity of organisms of one species. Our results show that the regionally weak species predominates in the local ecosystem, while spiral patterns appear far from the region, where individuals of every species play the rock-paper-scissors game with the same strength. Because the weak species controls all local territory, it is attractive for the other species to enter the local ecosystem to conquer the territory. However, our stochastic simulations show that the transitory waves formed when organisms of the strong species reach the region are quickly destroyed because of local strength unbalance in the selection game rules. Computing the effect of the topology on population dynamics, we find that the prevalence of the weak species becomes more significant if the transition of the selection capacity to the area of uneven rock-paper-scissors rules is smooth. Finally, our findings show that the biodiversity loss due to the arising of regional unevenness is minimised if the transition to the region where the cyclic game is unbalanced is abrupt. Our results may be helpful to biologists in comprehending the consequences of changes in the environmental conditions on species coexistence and spatial patterns in complex systems.

Handling and storing the immense amounts of data native to the information age is a major challenge in terms of technological sustainability and energy demand. To date, tape storage remains the most widespread method for data archiving, while DNA data storage appears to offer the best data density and long-term stability in the future. However, DNA data storage is still in its infancy primarily due to economic and accessibility challenges. This emphasizes the need for more practical and readily available alternatives. We present a method for data storage utilizing inkjet printable quantum dots on paper with photoluminescence (PL) readout. Our proof of principle study showcases the ability to print and stack multiple bits of data on a single spot by exploiting the unique PL properties of quantum dots. This approach utilizes easily accessible resources, including a consumer-grade printer and paper as the substrate. Additionally, we perform initial stability tests, investigate scalability by controlling emission intensity, and evaluate the potential data density achievable by our approach.

The determination of the dielectric breakdown strengths of microstructurally heterogeneous materials has been a primarily experimental endeavor. We report the development of a microstructure-level model for computationally predicting the breakdown strength and analyzing the interactions between electromagnetic pulses (EMP) and the constituents in a composite of cellulose-based paper and mineral oil found in electrical transformers. The model allows explicit simulation of the material breakdown process by tracking the transition of dielectric constituents from non-conductive to conductive states. The focus is on the electric fields induced in the materials and the overall conditions for dielectric breakdown (defined as the onset of avalanche) caused by the electric field induced in the composite. Responses to three distinct pulse shapes, i.e., Steep Front (SF), Lightning (L), and AC with spectra spanning 60–9 × 10 ^5 Hz are considered. It is found that the breakdown strength of the material is significantly affected by microstructure heterogeneities, the spatial variations of the constituent properties, and the pulse shapes. A probabilistic characterization of the breakdown strength is computationally obtained and compared with experimental measurements. Although one particular material is analyzed, the model and approach are applicable to other heterogeneous materials as well.

We use James Webb Space Telescope Near-Infrared Camera Wide Field Slitless Spectroscopy (NIRCam WFSS) and the Near-Infrared spectrograph (NIRSpec) in the Cosmic Evolution Early Release survey to measure rest-frame optical emission-line ratios of 155 galaxies at z > 2. The blind NIRCam grism observations include a sample of galaxies with bright emission lines that were not observed on the NIRSpec masks. We study the changes of the H α , [O III ]/H β , and [Ne III ]/[O II ] emission lines in terms of redshift by comparing to lower-redshift SDSS, CLEAR, and MOSDEF samples. We find a significant (>3 σ ) correlation between [O III ]/H β with redshift, while [Ne III ]/[O II ] has a marginal (2 σ ) correlation with redshift. We compare [O III ]/H β and [Ne III ]/[O II ] to stellar mass and H β SFR. We find that both emission-line ratios have a correlation with H β SFR and an anticorrelation with stellar mass across the redshifts 0 < z < 9. Comparison with MAPPINGS V models indicates that these trends are consistent with lower metallicity and higher ionization in low-mass and high-SFR galaxies. We additionally compare to IllustrisTNG predictions and find that they effectively describe the highest [O III ]/H β ratios observed in our sample, without the need to invoke MAPPINGS models with significant shock ionization components.

Version 11 of the chianti database and software package is presented. Advanced ionization equilibrium models have been added for low charge states of seven elements (C, N, O, Ne, Mg, Si, and S), and represent a significant improvement especially when modeling the solar transition region. The models include the effects of higher electron density and charge transfer on ionization and recombination rates. As an illustration of the difference these models make, a synthetic spectrum is calculated for an electron pressure of 7 × 10 ^15 cm ^−3 K and compared with an active region observation from HRTS. Increases are seen in factors of 2–5 in the predicted radiances of the strongest lines in the UV from Si iv , C iv , and N v , compared to the previous modeling using the coronal approximation. Much better agreement (within 20%) with the observations is found for the majority of the lines. The new atomic models better equip both those who are studying the transition region and those who are interpreting the emission from higher-density astrophysical and laboratory plasma. In addition to the advanced models, several ion data sets have been added or updated, and data for the radiative recombination energy loss rate have been updated.

The Cosmic Evolution Early Release Science program observed the Extended Groth Strip (EGS) with the Mid-Infrared Instrument (MIRI) on the James Webb Space Telescope (JWST) in 2022. In this paper, we discuss the four MIRI pointings that observed with longer-wavelength filters, including F770W, F1000W, F1280W, F1500W, F1800W, and F2100W. We compare the MIRI galaxies with the Spitzer/MIPS 24 μ m population in the EGS field. We find that MIRI can observe an order of magnitude deeper than MIPS in significantly shorter integration times, attributable to JWST's much larger aperture and MIRI’s improved sensitivity. MIRI is exceptionally good at finding faint ( L _IR < 10 ^10 L _⊙ ) galaxies at z ∼ 1–2. We find that a significant portion of MIRI galaxies are “mid-IR weak”—they have strong near-IR emission and relatively weaker mid-IR emission, and most of the star formation is unobscured. We present new IR templates that capture how the mid-to-near-IR emission changes with increasing infrared luminosity. We present two color–color diagrams to separate mid-IR weak galaxies and active galactic nuclei (AGN) from dusty star-forming galaxies and find that these color diagrams are most effective when used in conjunction with each other. We present the first number counts of 10 μ m sources and find that there are ≲10 IR AGN per MIRI pointing, possibly due to the difficulty of distinguishing AGN from intrinsically mid-IR weak galaxies (due to low metallicities or dust content). We conclude that MIRI is most effective at observing moderate-luminosity ( L _IR = 10 ^9 –10 ^10 L _⊙ ) galaxies at z = 1–2, and that photometry alone is not effective at identifying AGN within this faint population.

Mid-infrared (mid-IR) observations are powerful in identifying heavily obscured active galactic nuclei (AGN) that have weak emission in other wavelengths. Data from the Mid-Infrared Instrument (MIRI) on board the James Webb Space Telescope provides an excellent opportunity to perform such studies. We take advantage of the MIRI imaging data from the Cosmic Evolution Early Release Science Survey to investigate the AGN population in the distant universe. We estimate the source properties of MIRI-selected objects by utilizing spectral energy distribution (SED) modeling, and classify them into star-forming galaxies (SFs), SF-AGN mixed objects, and AGN. The source numbers of these types are 433, 102, and 25, respectively, from four MIRI pointings covering ∼9 arcmin ^2 . The sample spans a redshift range of ≈0–5. We derive the median SEDs for all three source types, respectively, and publicly release them. The median MIRI SED of AGN is similar to the typical SEDs of hot dust-obscured galaxies and Seyfert 2s, for which the mid-IR SEDs are dominated by emission from AGN-heated hot dust. Based on our SED-fit results, we estimate the black hole accretion density (BHAD; i.e., total BH growth rate per comoving volume) as a function of redshift. At z < 3, the resulting BHAD agrees with the X-ray measurements in general. At z > 3, we identify a total of 27 AGN and SF-AGN mixed objects, leading to that our high- z BHAD is substantially higher than the X-ray results (∼0.5 dex at z ≈ 3–5). This difference indicates MIRI can identify a large population of heavily obscured AGN missed by X-ray surveys at high redshifts.

We present a comprehensive analysis of the evolution of the morphological and structural properties of a large sample of galaxies at z = 3–9 using early James Webb Space Telescope (JWST) CEERS NIRCam observations. Our sample consists of 850 galaxies at z > 3 detected in both Hubble Space Telescope (HST)/WFC3 and CEERS JWST/NIRCam images, enabling a comparison of HST and JWST morphologies. We conduct a set of visual classifications, with each galaxy in the sample classified three times. We also measure quantitative morphologies across all NIRCam filters. We find that galaxies at z > 3 have a wide diversity of morphologies. Galaxies with disks make up 60% of galaxies at z = 3, and this fraction drops to ∼30% at z = 6–9, while galaxies with spheroids make up ∼30%–40% across the redshift range, and pure spheroids with no evidence for disks or irregular features make up ∼20%. The fraction of galaxies with irregular features is roughly constant at all redshifts (∼40%–50%), while those that are purely irregular increases from ∼12% to ∼20% at z > 4.5. We note that these are apparent fractions, as many observational effects impact the visibility of morphological features at high redshift. On average, Spheroid-only galaxies have a higher Sérsic index, smaller size, and higher axis ratio than disk or irregular galaxies. Across all redshifts, smaller spheroid and disk galaxies tend to be rounder. Overall, these trends suggest that galaxies with established disks and spheroids exist across the full redshift range of this study, and further work with large samples at higher redshift is needed to quantify when these features first formed.

We report on the host properties of five X-ray-luminous active galactic nuclei (AGN) identified at 3 < z < 5 in the first epoch of imaging from the Cosmic Evolution Early Release Science Survey. Each galaxy has been imaged with the JWST Near-Infrared Camera, which provides rest-frame optical morphologies at these redshifts. We also derive stellar masses and star formation rates for each host by fitting its spectral energy distribution using a combination of galaxy and AGN templates. We find that three of the AGN hosts have spheroidal morphologies, one is a bulge-dominated disk, and one is dominated by pointlike emission. None are found to show strong morphological disturbances that might indicate a recent interaction or merger event. When compared to a sample of mass-matched inactive galaxies, we find that the AGN hosts have morphologies that are less disturbed and more bulge-dominated. Notably, all four of the resolved hosts have rest-frame optical colors consistent with a quenched or poststarburst stellar population. The presence of AGN in passively evolving galaxies at z > 3 is significant because a rapid feedback mechanism is required in most semianalytic models and cosmological simulations to explain the growing population of massive quiescent galaxies observed at these redshifts. Our findings show that AGN can continue to inject energy into these systems after their star formation is curtailed, potentially heating their halos and preventing renewed star formation. Additional observations will be needed to determine what role this feedback may play in helping to quench these systems and/or maintain their quiescent state.

We present an investigation into the first 500 Myr of galaxy evolution from the Cosmic Evolution Early Release Science (CEERS) survey. CEERS, one of 13 JWST ERS programs, targets galaxy formation from z ∼ 0.5 to >10 using several imaging and spectroscopic modes. We make use of the first epoch of CEERS NIRCam imaging, spanning 35.5 arcmin ^2 , to search for candidate galaxies at z > 9. Following a detailed data reduction process implementing several custom steps to produce high-quality reduced images, we perform multiband photometry across seven NIRCam broad- and medium-band (and six Hubble broadband) filters focusing on robust colors and accurate total fluxes. We measure photometric redshifts and devise a robust set of selection criteria to identify a sample of 26 galaxy candidates at z ∼ 9–16. These objects are compact with a median half-light radius of ∼0.5 kpc. We present an early estimate of the z ∼ 11 rest-frame ultraviolet (UV) luminosity function, finding that the number density of galaxies at M _UV ∼ −20 appears to evolve very little from z ∼ 9 to 11. We also find that the abundance (surface density [arcmin ^−2 ]) of our candidates exceeds nearly all theoretical predictions. We explore potential implications, including that at z > 10, star formation may be dominated by top-heavy initial mass functions, which would result in an increased ratio of UV light per unit halo mass, though a complete lack of dust attenuation and/or changing star formation physics may also play a role. While spectroscopic confirmation of these sources is urgently required, our results suggest that the deeper views to come with JWST should yield prolific samples of ultrahigh-redshift galaxies with which to further explore these conclusions.

The new capabilities that JWST offers in the near- and mid-infrared (IR) are used to investigate in unprecedented detail the nature of optical/near-IR-faint, mid-IR-bright sources, with HST-dark galaxies among them. We gather JWST data from the CEERS survey in the Extended Groth Strip, jointly with HST data, and analyze spatially resolved optical-to-mid-IR spectral energy distributions to estimate photometric redshifts in two dimensions and stellar population properties on a pixel-by-pixel basis for red galaxies detected by NIRCam. We select 138 galaxies with F150W − F356W > 1.5 mag and F356W < 27.5 mag. The nature of these sources is threefold: (1) 71% are dusty star-forming galaxies (SFGs) at 2 < z < 6 with $9\lt \mathrm{log}{M}_{\star }/{M}_{\odot }\lt 11$ and a variety of specific SFRs (100 Gyr ^−1 ); (2) 18% are quiescent/dormant (i.e., subject to reignition/rejuvenation) galaxies (QGs) at 3 < z < 5, with $\mathrm{log}{M}_{\star }/{M}_{\odot }\sim 10$ and poststarburst mass-weighted ages (0.5–1.0 Gyr); and (3) 11% are strong young starbursts with indications of high equivalent width emission lines (typically, [O iii ]+H β ) at 6 < z < 7 (XELG- z 6) and $\mathrm{log}{M}_{\star }/{M}_{\odot }\sim 9.5$ . The sample is dominated by disk-like galaxies with remarkable compactness for XELG- z 6 (effective radii smaller than 0.4 kpc). Large attenuations in SFGs, 2 < A ( V ) < 5 mag, are found within 1.5 times the effective radius, approximately 2 kpc, while QGs present A ( V ) ∼ 0.2 mag. Our SED-fitting technique reproduces the expected dust emission luminosities of IR-bright and submillimeter galaxies. This study implies high levels of star formation activity between z ∼ 20 and z ∼ 10, where virtually 100% of our galaxies had already formed 10 ^8 M _⊙ , 60% had assembled 10 ^9 M _⊙ , and 10% up to 10 ^10 M _⊙ (in situ or ex situ).

We present results from the Cosmic Evolution Early Release Survey on the stellar population parameters for 28 galaxies with redshifts 4 < z < 9 using imaging data from the James Webb Space Telescope (JWST) Mid-Infrared Instrument (MIRI) combined with data from the Hubble Space Telescope and the Spitzer Space Telescope. The JWST/MIRI 5.6 and 7.7 μ m data extend the coverage of the rest-frame spectral energy distribution to nearly 1 μ m for galaxies in this redshift range. By modeling the galaxies’ SEDs the MIRI data show that the galaxies have, on average, rest-frame UV (1600 Å)— I -band colors 0.4 mag bluer than derived when using photometry that lacks MIRI. Therefore, the galaxies have lower ratios of stellar mass to light. The MIRI data reduce the stellar masses by $\langle {\rm{\Delta }}\mathrm{log}{M}_{* }\rangle =0.25$ dex at 4 < z < 6 and 0.37 dex at 6 < z < 9. This also reduces the star formation rates (SFRs) by 〈ΔlogSFR〉 = 0.14 dex at 4 < z < 6 and 0.27 dex at 6 < z < 9. The MIRI data also improve constraints on the allowable stellar mass formed in early star formation. We model this using a star formation history that includes both a “burst” at z _f = 100 and a slowly varying (“delayed- τ ”) model. The MIRI data reduce the allowable stellar mass by 0.6 dex at 4 < z < 6 and by ≈1 dex at 6 < z < 9. Applying these results globally, this reduces the cosmic stellar-mass density by an order of magnitude in the early Universe ( z ≈ 9). Therefore, observations of rest-frame ≳1 μ m are paramount for constraining the stellar-mass buildup in galaxies at very high redshifts.

In this paper, a simple method for preparing high stability superhydrophobic paper with pH-induced wettability transition was proposed. Firstly, the pH-responsive monomer 2- (dimethylamino) ethyl methacrylate (DMAEMA), the silicon-containing crosslinking monomer 3-trimethoxysilyl propyl methacrylate (TSPM) and the fluorine-containing monomer hexafluorobutyl methacrylate (HFMA) were polymerized to prepare the pH-responsive polymer PHFMA-PTSPM-PDMAEMA. Afterwards, the amino-modified SiO _2 was grafted onto the polymer to provide roughness and then coated on the paper to prepare the superhydrophobic paper with pH-responsive properties. Further research found that the modified paper prepared by this method not only has strong stability and transparency, but also can realize the reversible regulation of superhydrophobic & lipophilic and super-oleophobic & hydrophilic properties under different pH-induction, and it has important application value in the field of oil-water separation in industrial applications.

Low concentration of biomarkers (proteins, nucleic acids, metabolites) is a major concern in early disease diagnosis due to the very low concentration of these biomarkers at the early stage of any disease. This challenge can be addressed by preconcentrating the biomarkers to improve the sensitivity of the diagnostic device. This paper describes a novel method to preconcentrate the charged molecules on paper using greenly synthesized iron nanoparticles. The iron nanoparticles were synthesized by utilizing plant extract as stabilizing agent, which both minimizes the cost and protects the environment. Three different samples of the nanoparticles were prepared by changing the charge or attaching a functional group (amine) to the surface. The iron nanoparticles act as a charged nanoporous membrane when deposited on the paper pads inducing electrostatic forces around the membrane leading to the concentration of the charged analytes near the boundary of the membrane. Crystal violet was used as a surrogate for the charged biomolecule. We report ∼24-fold increase in the concentration of crystal violet dye within 120 seconds using the positively charged membrane and the 0.2 mM dye solution. The developed experimental set-up eliminates the need for external pumping device and complex fabrication processes making the proposed method cost-effective, environment-friendly, and simple to use.

With the development of printed electronics technology, the demand for printed conductive inks had also put forward higher standards. The shortcomings of traditional printed circuit boards, such as complex technology, consumables, and pollution, had also been resolved with the development of 3D printing technology. In this paper, low-content silver nanoparticles were blended with graphene alcohol slurry and dissolved in a non-polluting solvent such as absolute ethanol. The synergistic effect of the composite of the hexagonal structure of the graphene sheet and the silver nanoparticles improved the ink’s performance of electrical conductivity, adding water-based polyurethane/acrylic resin system to improve the adhesion between ink and paper. The conductive ink can be used to 3D print circuit circuits on paper. After drying, the resistance was measured. After the battery, diode, and switch were connected, a circuit diagram was made. After pressing the diode emits was lighted. This work is expected to be applied to flexible circuit boards to provide basic research.

Carbon paper is one of the most common carbon electrode materials employed in electrochemical research due to its low cost, disposability, and controllable dimensions and scaling. Carbon paper is usually hand cut and a variety of strategies are used to define electrode area. This procedure is tedious, imprecise, and inaccurate, yielding coefficients of variation in peak current output as high as 20%. Imprecision in hand-preparation translates directly to poor reproducibility in electrochemical data leading to challenges in directly comparing data across research groups and research fields. This work introduces an inexpensive and precise method to automatically cut and rapidly wax carbon paper electrodes, circumventing laborious traditional preparation and substantially improving precision in electrochemical data.

With the utilization of used newspaper into the paper making industry, bleaching has been an area of concern to obtain a balance between desired brightness and the amount of treatment it requires. Motivation of this study was to optimize bleaching of recycled newsprint fibers in terms of five variables namely hydrogen peroxide charge, amount of sodium hydroxide employed, pulp consistency, bleaching temperature, and bleaching time. Experimental work was conducted in the laboratory to simulate bleaching plant and it was found that higher peroxide charge is better for improvement in brightness, but it is uneconomical to increase peroxide charge indefinitely. The amount of hydrogen peroxide is added so that the residual peroxide at the end of the reaction is not less than 10% of the initially added peroxide. Sodium hydroxide provides alkalinity which is very important for making the fibers flexible and softening of ink particles but it also contributes to pulp yellowing if residual hydrogen peroxide contents are lesser than the minimum required value. So, for 16 kg t ^−1 of hydrogen peroxide, 6 kg t ^−1 of sodium hydroxide prevented the brightness reversion in this study. Higher pulp consistency is better but unavailability of very high consistency pulp mixer in the industry is a limiting factor for higher than 30% pulp consistency. Temperature and time are quite interrelated and, with the given bleaching conditions, a temperature of 95 °C with 10 min residence time was found to be optimum for this study. It was also observed that multiple pre-washings increase brightness and save bleaching chemicals.