Low-energy Processes Research Articles

Probing ALP lepton flavor violation at μTRISTAN

Axionlike particles (ALPs) with lepton flavor-violating (LFV) interactions are predicted within a wide range of flavored ALP models. The proposed μTRISTAN high-energy e−μ+ and μ+μ+ collider will provide a good opportunity to explore flavor physics in the charged lepton sector. In this work, based on a model-independent effective Lagrangian describing the ALP leptonic interactions, we investigate the potential of μTRISTAN to probe ALP LFV couplings. We analyze the testability of selected ALP production channels with potential sensitivity at μTRISTAN, considering different beams and collision energies, including e−μ+→aγ, e−μ+→e−τ+a, μ+μ+→μ+τ+a, and e−μ+→τ−μ+a. The produced ALP a is either long-lived or can promptly decay to flavor-violating or flavor-conserving charged lepton final states. In particular, combining the above LFV ALP production modes with a suitable LFV decay mode, one can identify signatures that are virtually free of Standard Model background. We show the resulting sensitivity of μTRISTAN to LFV ALP couplings and compare it with multiple low-energy leptonic constraints and the future improvements thereof. We find that μTRISTAN can be generally complementary to searches for low-energy LFV processes and measurements of the leptonic magnetic dipole moments and has the capability to explore unconstrained parameter space for ALP masses in the O(1)–O(100) GeV range. In the light ALP regime, however, the parameter space that μTRISTAN is sensitive to has been already excluded by low-energy searches for LFV decays. Published by the American Physical Society 2024

Using pile-up collisions as an abundant source of low-energy hadronic physics processes in ATLAS and an extraction of the jet energy resolution

During the 2015–2018 data-taking period, the Large Hadron Collider delivered proton-proton bunch crossings at a centre-of-mass energy of 13 TeV to the ATLAS experiment at a rate of roughly 30 MHz, where each bunch crossing contained an average of 34 independent inelastic proton-proton collisions. The ATLAS trigger system selected roughly 1 kHz of these bunch crossings to be recorded to disk. Offline algorithms then identify one of the recorded collisions as the collision of interest for subsequent data analysis, and the remaining collisions are referred to as pile-up.Pile-up collisions represent a trigger-unbiased dataset, which is evaluated to have an integrated luminosity of 1.33 pb−1 in 2015–2018. This is small compared with the normal trigger-based ATLAS dataset, but when combined with vertex-by-vertex jet reconstruction it provides up to 50 times more dijet events than the conventional single-jet-trigger-based approach, and does so without adding any additional cost or requirements on the trigger system, readout, or storage. The pile-up dataset is validated through comparisons with a special trigger-unbiased dataset recorded by ATLAS, and its utility is demonstrated by means of a measurement of the jet energy resolution in dijet events, where the statistical uncertainty is significantly reduced for jet transverse momenta below 65 GeV.

Integrated syngas biorefinery for manufacturing ethylene, acetic acid and vinyl acetate

The paper presents the design of an innovative process for manufacturing sustainable biochemicals, as acetic acid, ethylene and vinyl acetate monomer (VAM), in an integrated syngas biorefinery using renewable feedstock as biomethane and captured CO2. The work is supported by full design and simulation of six plants imbedded in a large process: syngas1 H2/CO 2:1 by catalytic partial oxidation of methane, syngas2 H2/CO 1:1 by dry methane reforming, methanol, acetic acid by carbonylation, ethylene and vinyl acetate. A key contribution is the development of a novel acetic-acid-to-ethylene process starting from syngas. This consists of catalytic hydrogenation of acetic acid (exothermic) followed by catalytic ethanol dehydration (endothermic). The thermal integration of reactors leads to low energy process and superior sustainability measures versus petrochemical and methanol-to-olefin processes. The comprehensive simulation of the integrated biorefinery allows getting consistent mass and energy balances, performing energy analysis and capital cost estimation, and finally delivering reliable sustainability measures. Based on syngas the carbon-yield, mass-yield, carbon footprint (kg CO2/kg product) and energetic requirement (MJ/kg) are 78.6%, 34.7%, 1.6 and 11.2 for ethylene, and 80.8%, 46.8%, 1.5 and 11.9 for VAM. At high biomethane price the ethylene may be costly but manufacturing the higher value VAM is fully profitable.

Luminescence Behavior and Structural Characteristics of Novel BaYAl3O7: Tb3+ Nanophosphors.

An innovative green emitting novel BaY1 - xTbxAl3O7 (x = 0.02, 0.03, 0.04, 0.05, and 0.06) was synthesized using urea combustion, which was a low-energy process. Using techniques such as photoluminescence (PL), X-ray diffraction (XRD), transmission electron microscopy (TEM), and energy dispersive x-ray (EDX) spectroscopy, the structure and luminous properties of the phosphor were investigated. Scherrer's equation was utilized in the XRD technique to determine the crystallite size of the suggested materials. When stimulated with the near-ultraviolet photon, PL spectra revealed intense green emission at 541nm (5D4 → 7F5). The composition with the maximum emission intensity is BaY0.96Tb0.04Al3O7. The dipole-dipole mechanism for concentration quenching events was identified with the help of the critical energy transfer distance. The non-radiative relaxation rate (276s- 1), radiative lifetime (0.75754 ms), and quantum efficiency (79%), of the ideal phosphor composition are calculated using Auzel's model. The color coordinates (0.260, 0.496) align with the emission of green light. The remarkable outcomes validated the significance of the targeted nanocrystals as a superior material with prospective applications in solid-state down-converted white light-emitting diodes (WLEDs).

Efficient and fast recovery of indium with phosphate-functionalized polyaniline porous carbon self-supported electrode by electrosorption-deposition strategy

Extraction of indium, that an important strategic resource, is limited by the low extraction capacity in the acidic environment, and sluggish adsorption kinetics. Electrodes and adsorption technologies can be combined to improve extraction capacity and kinetics, having high exploitation in metal recovery. A novel phytic acid-doped polyaniline/porous carbon (PA-PANI/PC) carbon cloth self-supported electrode is developed for extracting In(Ⅲ) from aqueous solutions by electrosorption-deposition strategy in this work. A series of characterization analysis show that PA-PANI/PC exhibits electrics double-layer capacitance and pseudocapacitance as well as abundant specific binding sites for In(Ⅲ) and improved hydrophilicity, which all conducive to the extraction of In(Ⅲ). As expected, PA-PANI/PC-2 exhibits the maximum extraction capacity of 284.67 mg/g within 60 min at pH 2.5, which represents the highest reported capacity for the extraction of In(Ⅲ), to date. Benefiting from complexation with phosphate groups, In(Ⅲ) can be directly recovered in the form of precipitation, avoiding backwashing with concentrated acid. Furthermore, the adsorbent maintains great affinity and selectivity for In(Ⅲ) even in multi-component simulated system. The low-cost adsorbent PA-PANI/PC based on simple and low-energy electrosorption-deposition process shows potential in terms of effectively recovering In(Ⅲ) from practical ore fluid.

Microstructural and Morphological Properties of AlNiCo and CoNi Alloys: An In-Depth Study Based on Low-Energy Mechanical Alloying

This study focused on synthesizing AlNiCo and CoNi materials using a low-energy milling process. The aim was to explore the formation of low-energy phases in both systems, contrasting with the typical research on phases formed under high-energy conditions. In the Co-20 wt% Ni system, the phases Co0.75Ni0.25 and Ni were identified, as well as the FCC cubic phase of CoNi, using X-ray diffraction (XRD) with a molybdenum radiation source. The observed behavior aligned closely with the miscibility curve in the equilibrium phase diagram, which included a region of alloys with varying structures and similar compositions. A notable feature was the presence of a predominantly dispersed hexagonal Ni zone, consisting of nanoparticles. Transmission electron microscopy (TEM) was employed to observe the FCC CoNi phase, which displayed a specific arrangement. AlNiCo and CoNi alloys were successfully synthesized through mechanical alloying, incorporating equilibrium and non-equilibrium phases.

Printed High-Entropy Prussian Blue Analogs for Advanced Non-Volatile Memristive Devices.

Non-volatile memristors dynamically switch between high (HRS) and low resistance states (LRS) in response to electrical stimuli, essential for electronic memories, neuromorphic computing, and artificial intelligence. High-entropy Prussian blue analogs (HE-PBAs) are promising insertion-type battery materials due to their diverse composition, high structural integrity, and favorable ionic conductivity. This work proposes a non-volatile, bipolar memristor based on HE-PBA. The device, featuring an active layer of HE-PBA sandwiched between Ag and ITO electrodes, is fabricated by inkjet printing and microplotting. The conduction mechanism of the Ag/HE-PBA/ITO device is systematically investigated. The results indicate that the transition between HRS and LRS is driven by an insulating-metallic transition, triggered by extraction/insertion of highly mobile Na+ ions upon application of an electric field. The memristor operates through a low-energy process akin to Na+ shuttling in Na-ion batteries rather than depending on formation/rupture of Ag filaments. Notably, it showcases promising characteristics, including non-volatility, self-compliance, and forming-free behavior, and further exhibits low operation voltage (VSET = -0.26 V, VRESET = 0.36 V), low power consumption (PSET = 26 µW, PRESET = 8.0 µW), and a high ROFF/RON ratio of 104. This underscores the potential of high-entropy insertion materials for developing printed memristors with distinct operation mechanisms.

Precise 113Cd β\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\beta $$\\end{document} decay spectral shape measurement and interpretation in terms of possible gA\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$g_A$$\\end{document} quenching

Highly forbidden β\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\beta $$\\end{document} decays provide a sensitive test to nuclear models in a regime in which the decay goes through high spin-multipole states, similar to the neutrinoless double-β\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\beta $$\\end{document} decay process. There are only 3 nuclei (50V, 113Cd, 115In) which undergo a 4th\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$4^\ extrm{th}$$\\end{document} forbidden non-unique β\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\beta $$\\end{document} decay. In this work, we compare the experimental 113Cd spectrum to theoretical spectral shapes in the framework of the spectrum-shape method. We measured with high precision, with the lowest energy threshold and the best energy resolution ever, the β\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\beta $$\\end{document} spectrum of 113Cd embedded in a 0.43 kg CdWO4\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hbox {CdWO}_4$$\\end{document} crystal, operated over 26 days as a bolometer at low temperature in the Canfranc underground laboratory (Spain). We performed a Bayesian fit of the experimental data to three nuclear models (IBFM-2, MQPM and NSM) allowing the reconstruction of the spectral shape as well as the half-life. The fit has two free parameters, one of which is the effective weak axial-vector coupling constant, gAeff\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$g_A^{\ ext {eff}}$$\\end{document}, which resulted in gAeff\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$g_A^{\ ext {eff}}$$\\end{document} between 1.0 and 1.2, compatible with a possible quenching. Based on the fit, we measured the half-life of the 113Cd β\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\beta $$\\end{document} decay including systematic uncertainties as 7.73-0.57+0.60×1015\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$7.73^{+0.60}_{-0.57} \ imes 10^{15}$$\\end{document} yr, in agreement with the previous experiments. These results represent a significant step towards a better understanding of low-energy nuclear processes.

Antifeedant Nanosuspension Formula of <i>Tithonia diversifolia</i> Leaf Extract by Emulsion Inverse Method to Control <i>Crocidolomia pavonana</i> Cabbage Pest Insect

The leaf extract from Tithonia diversifolia is recognized for its ability to deter feeding in various Lepidoptera insect pests, including the larvae of Crocidolomia pavonana. Presently, transformation efforts from conventional formulations into nano-based formulations for biopesticides exhibit enhanced effectiveness and efficiency. Utilizing a low-energy process, an inversion emulsion facilitates the dispersion of the extract suspension in an organic solvent into a water-immiscible solvent using a suitable surfactant. The forming nano-size droplets in water (t1, t2, t3, t4) are influenced by the ratio of surfactant and organic suspension (Water: Tween 80: Organic suspension). The emulsification method successfully formulated T. diversifolia leaf extract, into dispersed nano-size and submicron suspensions in water. The t3 formula exhibits the smallest nano-size dispersed in water (D=23.6 ± 39.6 nm; polydispersity index IP=0.702) and enhanced wettability, evident in the lower contact angle of the droplet on the cabbage leaf surface (49.4°) compare with the control group. The Phytochemicals confirmed by IR-spectra analysis identified the phenols, alkaloids, and steroids constituents of leaf extract, which are known to have antifeedant properties. The enhanced antifeedant properties of T. diversifolia nanosuspension against C. pavonana third-instar larvae demonstrated by the antifeedant test results showing that t3 is the most successful deterrent larvae feeding activity compared to the control (P<0.05), due to the highest total antifeedant coefficient (74.27%) in a category medium antifeedant activity, while the non-emulsification displayed the lowest antifeedant coefficient (25.36%) in a category as low antifeedant activity. T. diversifolia leaf extract with a nano-based formula succeeded resulting in dispersed nano-size and submicron suspension in aqueous media, thereby reducing surface tension and enhancing wettability on the leaf surface during application. The improved dispersion of antifeedant nanosuspension on the leaf surface results in more effective delivery to target insects.

Boosting α to β transformation of PVDF/HFP through natural hydroxyapatite derived from animal bones for eco-friendly energy harvesters

Appropriate additives can significantly enhance the piezoelectric properties of piezoelectric materials. In particular, eco-friendly ceramics made from natural sources, such as animal bones, can be produced in a low-energy process and contribute to a lower carbon footprint. In this study, hydroxyapatite (HA) particles were produced by synthesizing natural bovine bone by means of mechanosynthesis route and employed as nucleating agents to enhance self-polarization of piezoelectric polymers. With a simple and eco-friendly manufacturing process, the HA is embedded in polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP). Scanning electron microscope (SEM), and Fourier transform infrared spectroscopy analysis (FTIR) were used to examine the distribution uniformity of hydroxyapatite particles and investigate the effect of particles on the crystallinity of polymer composite. In addition, electrical and piezoelectric measurements were conducted to illustrate the effect of HA contents on the performance of the realized films. By increasing the contents of HP, the relative fraction of β-phase increased sharply for 20 wt % HA/PVDF-HFP film, leading to high piezoelectric performance. The films made with 20 wt%HA/PVDF-HFP had a maximum output voltage of 2 V and a maximum output power of 1.75 μW and were 0.8 V and 0.25 μW for the pristine PVDF-HFP film illustrating the significant role of HA for α-to β-phase transformation. Furthermore, adding 20 wt % hydroxyapatite (HA) to PVDF-HFP enhanced the dielectric properties. Under walking, the realized biocomposite was able to harvest body energy into useable electricity up to 4 V. In this study, bio-derived materials are shown to have great potential for affordable eco-friendly nanogenerators that produce electricity from body movements.

Leveraging multiplexed metasurfaces for multi-task learning with all-optical diffractive processors.

Diffractive Neural Networks (DNNs) leverage the power of light to enhance computational performance in machine learning, offering a pathway to high-speed, low-energy, and large-scale neural information processing. However, most existing DNN architectures are optimized for single tasks and thus lack the flexibility required for the simultaneous execution of multiple tasks within a unified artificial intelligence platform. In this work, we utilize the polarization and wavelength degrees of freedom of light to achieve optical multi-task identification using the MNIST, FMNIST, and KMNIST datasets. Employing bilayer cascaded metasurfaces, we construct dual-channel DNNs capable of simultaneously classifying two tasks, using polarization and wavelength multiplexing schemes through a meta-atom library. Numerical evaluations demonstrate performance accuracies comparable to those of individually trained single-channel, single-task DNNs. Extending this approach to three-task parallel recognition reveals an expected performance decline yet maintains satisfactory classification accuracies of greater than 80 % for all tasks. We further introduce a novel end-to-end joint optimization framework to redesign the three-task classifier, demonstrating substantial improvements over the meta-atom library design and offering the potential for future multi-channel DNN designs. Our study could pave the way for the development of ultrathin, high-speed, and high-throughput optical neural computing systems.

Erratum to: Catalysis As a Quark-Cumulative Mechanism for Initiating Low-Energy Nuclear Chemical Processes: Phenomenology

Erratum to: Catalysis As a Quark-Cumulative Mechanism for Initiating Low-Energy Nuclear Chemical Processes: Phenomenology

Spontaneous combustion coal gangue-based composite cement: Compressive performance and environmental benefits under grinding kinetics control

This study aims to tackle the environmental pressure of spontaneous combustion coal gangue by using its active silica-alumina content to create eco-friendly composite cement through a low-energy process. The Divas-Aliavden grinding kinetics equation was established, and powder characteristics were analyzed using particle size distribution, the Rosin-Rammler-Bennett model, and fractal dimension theory. The compressive performance of the coal gangue-based composite cement was tested. A comprehensive evaluation model linked grinding time, powder characteristics, compressive performance, and energy consumption, while also analyzing hydration products and environmental impact. Results showed that initial grinding stages had larger particle sizes and higher energy utilization efficiency. As grinding progressed, energy consumption increased. A grinding time of 35 min achieved optimal balance between energy efficiency and compressive performance, improving particle distribution uniformity and complexity. The compressive performance of the composite cement reached 95 % of ordinary Portland cement after 28 days of curing. The evaluation model indicated that specific surface area, d50, and fractal dimension are key factors influencing energy efficiency, determining energy consumption and particle distribution during grinding. Environmental assessment revealed that substituting 30 % of cement with coal gangue could reduce CO2 emissions by 250 kg CO2/t, achieving a reduction rate of 29.5 %. This study supports the large-scale application of spontaneous combustion coal gangue, contributing to efficient resource utilization and environmental protection.

New Biorefinery Approach for the Valorization of Fruit Processing Waste at a Local Scale: Pomegranate Pomace as Case Study

AbstractThe processing of fruit and vegetables generates globally high amount of organic waste, which is suitable to be valorized because of the chemistry it encloses. Conventional treatment methods for waste biomass generate low value products and cause climate altering emissions. Small biorefineries are valid alternatives for the sustainable waste biomass conversion, but their feasibility is strictly related to the use of low-energy process, and the market positioning of the final product. The present work provides an innovative approach for the green conversion of vegetable waste into high value product, with the aim to encourage the deployment of biorefinery at a local scale. It involves the enzymatic disassimilation of plant cell wall into chemicals with specific functions, and their recombination in form of emulsion, as a product prototype for food and cosmetic sector. To explain the biorefinery model, we applied it to pomegranate pomace, the residue from juicing, for the recovery of oil, pectin and antioxidant molecules via enzyme assisted extraction. The process left behind 30% of the initial solid waste. Finally, the dispersion of pomegranate oil into pomegranate pectin solution as emulsifier, brought to a novel emulsion, 98.9% waste-derived, further functionalizable with pomegranate exocarp hydrolysate with high antioxidant capacity. Graphical Abstract

Enhancing the anti-wear performance of graphene sheets embedded carbon films through interface nanotexture fabricated on the substrate

The effect and mechanism of surface texture on friction have been extensively explored, such as storing the abrasive and reducing the real contact area. However, studying the impact of the interface texture remains crucial, especially as the texture size approaches the nanoscale. In the present work, the silicon substrate with different parameters nanotexture was fabricated using a metal-assisted chemical etching process, and the graphene sheets embedded carbon (GSEC) film was deposited on the nanotextured substrate via a low-energy electron irradiation process to produce the interface nanotextured carbon films. After the addition of the interface nanotexture, the tribological performance of carbon films exhibited significant enhancement, with the degree of improvement being influenced by the parameters of the interface nanotexture. A super-low wear rate was achieved, with a value of 6.54 ± 0.70 × 10−8 mm3/N m. The improved tribological performance is due to the enhancement of film-substrate adhesion strength facilitated by interface nanotexture, and its role in promoting the rapid formation of a stable transfer film on the counter-grinding ball. The carbon film with nanotexture displays a small size of the abrasive particles, which contributes to the stabilization of the friction process.

Dark matter scattering off H2 and He4 nuclei within chiral effective field theory

We study dark matter, assumed to be composed of weak interacting massive particles (WIMPs), scattering off H2 and He4 nuclei. In order to parametrize the WIMP-nucleon interaction, the chiral effective field theory approach is used. Considering only interactions invariant under parity, charge conjugation, and time reversal, we examine five interaction types: scalar, pseudoscalar, vector, axial, and tensor. Scattering amplitudes between two nucleons and a WIMP are determined up to second order of chiral perturbation theory. We apply this program to calculate the interaction rate as a function of the WIMP mass and of the magnitude of the WIMP-quark coupling constants. From our study, we conclude that the scalar nuclear response functions is much greater than the others due to their large combination of low energy constants. We verify that the leading order contributions are dominant in these low energy processes. We also provide an estimate for the background due to atmospheric neutrinos. Published by the American Physical Society 2024

Low-energy thermo-chemical conversion processes of municipal wet waste

Hydrothermal carbonization (HTC) is a low-energy thermochemical process that converts wet biomass into a carbon-rich solid, commonly called hydrochar, for use in a variety of areas, such as soil amendment, biofuels or to produce carbon-based materials. The purpose of this paper is to increase knowledge for the economic valorization of municipal wet waste, considered as a raw material to obtain high value-added products through an HTC process and an additional chemical activation procedure. In the first part of the work, a 4.5-liter batch reactor was designed, built, and used in the HTC experimental campaign by varying the main process parameters, namely reaction time, amount and type of organic waste (e.g. vegetables, fruits, bread, pasta), water concentration, temperature and pressure. In addition, some experiments were conducted by applying the steam explosion technique at the end of the HTC process. The HTC results showed that in biomass with high water content, increasing residence time decreases the hydrochar yield. Considering a dry heterogeneous waste with high carbon content, the yields at the end of the process are much higher. In the second part of this work, the hydrochar samples were treated with a high-temperature activation process based on the use of KOH, obtaining activated carbon. Particularly, the best results were achieved by using high KOH: hydrochar ratios, resulting in high-quality activated carbons with good porosity and a high surface area of 2890 m2/g. Finally, an energy analysis was carried out to evaluate how to make the whole process cost-effective.

One-loop analysis of β decays in SMEFT

We perform a loop-level analysis of charged-current (CC) processes involving light leptons and quarks within the Standard Model Effective Field Theory (SMEFT). This work is motivated by the high precision reached in experiment and Standard Model calculations for CC decays of mesons, neutron, and nuclei, and by a lingering tension in the Cabibbo universality test. We identify the SMEFT operators that induce the largest loop-level contributions to CC processes. These include four-quark and four-fermion semileptonic operators involving two third-generation quarks. We discuss the available constraints on the relevant effective couplings and along the way we derive new loop-level bounds from K → πνν¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\pi \ u \\overline{\ u} $$\\end{document} on four-quark operators involving two top quarks. We find that low-energy CC processes are quite competitive with other probes, set constraints that do not depend on flavor-symmetry assumptions, and probe operators involving third-generation quarks up to effective scales of Λ ≃ 8 TeV. Finally, we briefly discuss single-field ultraviolet completions that could induce the relevant operators.

Decolorization of Lignin for High-Resolution 3D Printing of High Lignin-Content Composites.

Lignin, one of the most abundant biomaterials and a large-scale industrial waste product, is a promising filler for polymers as it reduces the amount of fossil resources and is readily available. 3D printing is well-known for producing detailed polymer structures in small sizes at low waste production. Especially light-assisted 3D printing is a powerful technique for production of high-resolution structures. However, lignin acts as a very efficient absorber for UV and visible light limiting the printability of lignin composites, reducing its potential as a high-volume filler. In this work, the decolorization of lignin is presented for high-resolution 3D printing of biocomposites with lignin content up to 40wt.%. Organosolv lignin (OSL) is decolorized by an optimized low-energy process of acetylation and subsequent UV irradiation reducing the UV absorbance by 71%. By integration of decolorized lignin into bio-based tetrahydrofurfuryl acrylate (THFA), a lignin content of 40wt.% and a resolution of 250µm is achieved. Due to the reinforcing properties of lignin, the stiffness and strength of the material is increased by factors of 15 and 2.3, respectively. This work paves the way for the re-use of a large amount of lignin waste for 3D printing of tough materials at high resolution.

High-performance sulfur-rich COF/PTFE composite membrane for the efficient removal of Hg(II) from acidic wastewater

Covalent organic frameworks (COFs) have emerged as advanced materials for addressing heavy metal pollution in acidic environments. However, powdered COF adsorbents face challenges such as poor operability and a tendency to agglomerate, limiting their industrial wastewater treatment applications. In this study, we prepared a sulfur-rich COF-OSH/mPTFE composite membrane through in situ growth and subsequent modification of COFs on the surface of amino-functionalized PTFE porous membranes. The COF-OSH/mPTFE composite exhibits a remarkable adsorption capacity for mercuric cations (Hg2+), reaching 223.5 mg/g. Notably, even at pH 1, the adsorption capacity remains high at 68.9 mg/g. The adsorption process demonstrates excellent resistance to interference from Na+ and Ca2+ ions and shows good reusability. Furthermore, COF-OSH/mPTFE reduced the concentration of Hg2+ in a 100 mL solution (5 mg/L) by over 80 % within 13 min at pH 5, and by over 40 % at pH 2. Even after continuous treatment of 20 L of Hg2+ solution, a significant reduction in Hg2+ concentration in the filtrate was still observed. The COF-OSH/mPTFE composite membrane addresses the cleanliness and recovery issues associated with powdered adsorbents in adsorption environments. The simple, efficient, and low-energy filtration process endows COF-OSH/mPTFE with excellent capability for treating acidic wastewater containing Hg2+.