Conversion Method Research Articles

Process Simulation, Thermodynamic and System Optimization for the Low-Carbon Alcohols Production via Gasification of Second-Generation Biomass

Biomass-to-liquid fuels technology offers a promising method for high-value biomass conversion, addressing environmental toxicity and fossil fuel non-renewability. However, challenges such as low system efficiency and identifying efficiency losses persist. In this study, a comprehensive process model of a low-carbon alcohols production system via biomass gasification was developed, based on the first demonstration project in China. The innovation of this study lies in its detailed experimental validation, as the model simulation was performed using laboratory data and verified with pilot-scale platform data ensuring high accuracy. Additionally, the study conducted a thorough sensitivity analysis of system parameters, energy, and exergy assessments to find the proper operating conditions, including equivalent ratio, biomass type, and reactor temperature and pressure. The simulation results demonstrated an energy efficiency of 34.67% and an exergy efficiency of 31.24%. Through operating parameters and heat recovery measures, these efficiencies increased by 11.66% and 8%, respectively. This research not only obtains improved operating parameters for the pilot-scale platform but also provides actionable insights for enhancing the yields of target products and upgrading low-grade energy utilization. These findings offer valuable guidance for the commercialization of bio-syngas alcohols production systems, highlighting significant advancements in efficiency and system performance.

High-Na-Content Birnessite via P'3-Stacking with Tunable Active Facets for Advanced Aqueous Sodium-Ion Batteries.

Layered Na-birnessites are promising cathode materials for aqueous sodium-ion batteries due to their high theoretical capacity, low cost, and environmental benignity. However, the general O'3 Na-birnessites possess low Na content and dominant inactive {001} exposed facets, which compromise their Na storage capability and cycling stability. Herein, we develop a high-Na-content P'3-Na0.71MnO2·0.15H2O with highly enriched {010} active facets by a hydrothermal conversion method. In comparison with the O'3 Na-birnessite, the P'3 Na-birnessite with a high ratio of {010}/{001} exposed facets provides greatly increased open channels for Na+ diffusion, while the P'3 stacking affords a lower Na+ diffusion barrier, resulting in improved electrode kinetics with a large specific capacity of 176 mAh g-1 at 0.2 A g-1. More importantly, the P'3 Na-birnessite manifests solo Na+ intercalation/deintercalation with extraordinary cycling stability in an aqueous electrolyte, achieving 90.5% capacity retention after 60,000 cycles. When coupled with the NaTi2(PO4)3 anode, the P'3 Na-birnessite-based full cell delivers both high energy density and long cycle life, demonstrating the potential application in aqueous sodium-ion batteries. This study demonstrates an efficient method to prepare high-Na-content P'3 birnessite with tunable exposed facets and provides important insights into developing highly stable layered cathodes for sustainable aqueous sodium-ion batteries.

A novel intelligent bearing fault diagnosis method based on image enhancement and improved convolutional neural network

Bearing fault diagnostic is crucial for ensuring the normal operation of equipment. However, the working environment of mechanical equipment is often very harsh, the collection of fault data is limited in the actual industrial process. The problem of insufficient fault samples occurs, which makes the feature extraction ability of the deep learning models drop dramatically. To solve this terrible problem, an intelligent diagnosis framework based on image enhancement and an improved convolutional neural network (IEICNN) is outlined in this article. First, a signal conversion method based on feature fusion is employed to convert multi-channel one-dimensional vibration signals into red − green − blue (RGB) images to obtain more comprehensive fault data representation. In addition, a new image enhancement method is proposed, which uses the improved Squeeze and Excitation-Residual Network (SE-ResNet) to learn and extract the advanced feature map, and uses deconvolution neural networks to reconstruct RGB image. Finally, the Softmax classifier is applied to identify the health conditions of the bearing. The superiority and robustness of IEICNN are validated using two bearing datasets. By comparing with several progressive comparison approaches, it is proven that the proposed approach has better robustness and effectiveness in the case of limited data scarcity.

A novel bio-aerogel based on agroforestry waste chestnut shell for enhanced oil-water separation performance

Bio-based aerogels have attracted much attention due to their biodegradability and excellent oil-water separation properties. However, the preparation of inexpensive green aerogels with high separation efficiency is still a great challenge. In this paper, low-density, high-adsorption capacity and superhydrophobic chestnut shell-based bio-aerogels were prepared by chemical cross-linking and chemical vapor deposition using agricultural and forestry waste chestnut shells as the precursor of aerogels to achieve high efficiency of oil-water separation and to achieve the goal of “treating waste with waste”. The covalent cross-linking of chestnut shell cellulose and cross-linking agent to form silicone-containing functional groups improved the pore structure, hydrophobicity and mechanical properties of chestnut shell cellulose, and under the action of capillary force, the oil was retained in the pores of the bio-aerogels, which achieved the selective adsorption of oil and organic solvents in the oil-water mixture, with a separation efficiency of more than 98 %. After 10 cycles, the bio-aerogel still has good reusability. This eco-friendly and low-cost aerogel provides a practical method for resource conversion and recycling, as well as a green and innovative way for the treatment of oily wastewater.

Pulsed polarized vortex beam enabled by metafiber lasers

Pulsed polarized vortex beams, a special form of structured light, are generated by tailoring the light beam spatiotemporally and witness the growing application demands in nonlinear optics such as ultrafast laser processing and surface plasma excitation. However, existing techniques for generating polarized vortex beams suffer from either low compactness due to the use of bulky components or limited controlment of pulse performance. Here, an all-fiber technique combining plasmonic metafibers with mode conversion method is harnessed to generate high-performance pulsed polarized vortex beams. Plasmonic metafibers are utilized as saturable absorbers to produce Q-switched pulses with micro-second duration, while the offset splicing method is employed to partially convert the fundamental transverse mode (LP01\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_{01}$$\\end{document}) to higher-order mode (LP11\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_{11}$$\\end{document}). Eventually, a polarized vortex beams laser is achieved at the telecom band with a repetition frequency of 116.0 kHz. The impact of geometrical parameters including period of metafibers and offset of splicing on the spatiotemporal properties of pulsed polarized vortex beams is systematically investigated. Our findings could pave the way for design, control and generation of all-fiber pulsed polarized vortex beams, and also offer insights into the development of other types of structured laser sources.

A method for data conversion of exposure level testers using sinusoidal alternating magnetic fields

Flux density measurements provide valuable information on the state of electrical appliances, which can be utilised for improving the safety and the performance of the associated system. Exposure level testers with a B-field probe are widely used for flux density measurements but they can only perform a time-domain measurement and display it as output voltage related to flux density. In other words, they cannot output flux density directly, which brings many inconveniences. These drawbacks can be improved using data conversion coefficients. However, the test frequencies of most exposure level testers are greater than 1 Hz. They are unable to calculate the data conversion coefficients using a constant magnetic field. This paper proposes a method for data conversion of exposure level testers using alternating magnetic fields to measure flux density directly: the flux density conversion model was established; the mathematical relationship between the mean value of the voltage signal output by the exposure level testers and its stable display value was deduced; and an experimental test of the conversion coefficients was carried out. The results show that the error between the value measured using the new technique and the display value of the exposure level tester at different frequencies is small. This method can trace the flux density in both the time and frequency domains through software processing algorithms without changing the exposure level tester itself. By applying sinusoidal magnetic fields and using the conversion factor, then existing testers can be used to measure flux density directly.

Symbol-level scheme for combating eavesdropping: Symbol conversion and constellation adjustment

In the non-orthogonal multiple access scenario, users may suffer inter-multiuser eavesdropping due to the feature of successive interference cancellation, and the conditions of eavesdropping suppression methods in the traditional schemes may not be satisfied. To combat this eavesdropping, we consider physical layer security and propose a novel scheme by specially designing symbol conversion and constellation adjustment methods. Based on these methods, the amplitudes and phases of symbols are properly changed. When each user intercepts information as an eavesdropper, he/she has to accept high error probability, or he/she has to undergo exorbitant overhead. Analytical and numerical results demonstrate that the proposed scheme can protect the privacy of information, and this protection does not destruct the execution of successive interference cancellation and symbol transmission.

A review of the progress and developments of green chemistry

The purpose of this review is to present the progress and development of a fundamental field that aims to design chemical processes with as little adverse effect on the environment as possible. The paper discusses the relevance of changes in industries considering the impact of the conventional chemical industry on the environment, people, and resources, with pollution, toxicity, and depletion of the resources being alarming effects. Waste minimization as one of the ten principles of green chemistry, atom economy and safer solvents and auxiliaries, is also described in detail. In the best practice examples drawn from key industries such as Unilever and BASF, a positive approach toward integrating biodegradable materials and renewable resources is evident. Furthermore, new developments in the catalysis and biocatalysts techniques as well as innovative methods of carbon dioxide conversion are also explored to demonstrate that sustainability is a core direction of chemical transformations. Nevertheless, prospects are evident albeit constrained in economic, regulatory, and technical sectors. Overcoming these barriers is crucial to the complete realization of green chemistry in the industry and the scale-back of environmental harm. It is for this reason that the present review offers a final reflection on how both green chemistry and a circular economy can change various sectors and offer more sustainable solutions.

Rapid Prototyping of Multiscale Flexible Printed Circuit Boards with NeXus, a Robotic Additive Manufacturing System

Abstract This paper demonstrates the NeXus system, a multi-scale robotic additive manufacturing platform developed at the Louisville Automation and Robotics Research Institute (LARRI), as a rapid prototyping tool through additively manufacturing a multi-layer flexible printed circuit board (FPC) with a printed strain sensor and soldered Surface Mounted Devices (SMD). Manufacturing of the demonstrator requires the application and curing of multiple materials with specialized properties, tools for automated assembly, and software advances to streamline the process enabling the use of industry-standardized programs to command the NeXus system. Additive manufacturing processes supported by the NeXus include Aerosol Jet printing (AJP) for fine feature silver conducting lines, direct write ink-jet printing for insulating materials, and Intense Pulsed Light (IPL) for curing materials between depositions. The NeXus system transports and manipulates parts using a 5-DOF high-precision positioner. Solder paste deposition and pick-and-place (PnP) procedures are performed by a 4-DOF Selective Compliance Articulated Robot Arm (SCARA). Conversion methods between traditional PCB design software and production-ready command scripts were developed to translate basic drawings into command scripts. Multilayer structures with AJP 50-micron wide lines, an insulating bridge with a thickness of around 100 microns, and SMDs soldered to silver AJP pads, were integrated within the demonstrator. An operational amplifier, and other SMDs, reduce the complexity of the accompanying control circuit and amplifies the sensor?s response by 1,830 times. The successful fabrication of the demonstrator FPC highlights the rapid prototyping ability of the NeXus System.

Energy Recovery from Municipal Sewage Sludge: Combustion Kinetics in a Varied Oxygen–Carbon Dioxide Atmosphere

Energy from municipal sewage sludge can be obtained by applying a thermal conversion method. In this study, the combustion kinetics of municipal sewage sludge were analyzed in an O2/CO2 atmosphere. Studies were conducted in different gaseous atmospheres consisting of varying proportions of oxygen and carbon dioxide. The participation of oxygen was as follows: 20, 40, 60, 80 and 100% vol. The experimental temperatures varied from 873 to 1273 K. The experimentally obtained results helped establish the basic kinetic parameters, such as the reaction order n, factor Ko and activation energy Ea of sludge grains. The values of the activation energy Ea and Ko were, respectively, 46 kJ/mol and 0.0127 mg/m2sPa. They show that the limiting factor of combustion is the diffusion of oxygen and that combustion reactions take place in the outer layer of the unreacted core. Therefore, sludge is promising for energy recovery because it has quite a high net calorific value (NCV) and a high gross calorific value (GCV). The GCV was 14.1 MJ/kg and the NCV was 12.8 MJ/kg. The experimental studies with a wide range of process parameters helped to create an array of apparent reaction rates as a function of the temperature and oxygen concentration, showing the significant effect of oxygen on the apparent reaction rate, in contrast to the effect of temperature.

Visualization Study on Oil Return Characteristics of Vapor Compression Heat Pump System

Vapor compression heat pump technology is a widely utilized method for energy conversion. Lubricating oil plays a crucial role in the heat pump system cycle by effectively reducing wear on the compressor’s moving parts and preventing refrigerant leakage. However, it can also create an oil film in the heat exchange equipment, which increases thermal resistance and diminishes heat transfer efficiency. This study utilizes a vapor compression heat pump system test bench to investigate factors influencing the system’s oil circulation rate, the two-phase flow patterns of refrigerant and lubricating oil, and the impact of oil circulation on system performance. The findings reveal that as the compressor speed increases, the oil circulation rate initially decreases before increasing again. Additionally, a decrease in the evaporator’s heat load leads to a reduction in oil circulation at high temperatures, while it increases at low temperatures. Furthermore, increasing the opening of the electronic expansion valve results in a gradual decrease in the oil circulation rate, whereas an increase in the refrigerant charge correlates with a rise in the oil circulation rate. The oil return flow pattern can primarily be categorized into three states: slow oil return, oil film flow, and high-speed oil return. These patterns are closely related to the degree of superheat, with lower superheat levels intensifying oil return.

Research on self-supporting flexible cathode materials with high LFP loading based on PAN in situ inorganic reaction

High loading flexible electrode material is a key component of flexible batteries. This article prepares a flexible electrode by using electrospinning technology that achieves high conductivity and self-supporting without adhesive and current collector. This structural advantage is attributed to the high compatibility and fibrosis of PAN (polyacrylonitrile) and LFP/CNF, which is transformed in situ by precursor conversion method into a flexible self-supporting composite electrode with continuous carbon fiber/CNF as the conductive phase and LFP(LiFePO4) as the lithium storage phase. These flexible materials achieving a specific capacity of 110.5 mAh/g at 0.1C, 92 mAh/g at 0.5C, and 58 mAh/g at 3C, further demonstrated reversible charge and discharge cycles after mechanical bending. These findings highlight the potential of LFP/CNF electrodes for flexible and high-performance energy storage applications.

Exploring Fast and Flexible Zero‐Shot Low‐Light Image/Video Enhancement

AbstractLow‐light image/video enhancement is a challenging task when images or video are captured under harsh lighting conditions. Existing methods mostly formulate this task as an image‐to‐image conversion task via supervised or unsupervised learning. However, such conversion methods require an extremely large amount of data for training, whether paired or unpaired. In addition, these methods are restricted to specific training data, making it difficult for the trained model to enhance other types of images or video. In this paper, we explore a novel, fast and flexible, zero‐shot, low‐light image or video enhancement framework. Without relying on prior training or relationships among neighboring frames, we are committed to estimating the illumination of the input image/frame by a well‐designed network. The proposed zero‐shot, low‐light image/video enhancement architecture includes illumination estimation and residual correction modules. The network architecture is very concise and does not require any paired or unpaired data during training, which allows low‐light enhancement to be performed with several simple iterations. Despite its simplicity, we show that the method is fast and generalizes well to diverse lighting conditions. Many experiments on various images and videos qualitatively and quantitatively demonstrate the advantages of our method over state‐of‐the‐art methods.

Enhanced Hg(II) reduction activity over two-dimensional n-n heterojunction MoS2/Bi2WO6 nanocomposites under visible light illumination

The engineering of band structure acts as an effective avenue to promote photocatalytic redox reactions, which can be achieved by fabricating heterojunction photocatalysts. Herein, MoS2 NPs were anchored on the surface of the mesoporous Bi2WO6 network through a facile sol-gel process to form heterostructure MoS2/Bi2WO6 nanocomposites. HR-TEM and XRD results of the obtained MoS2/Bi2WO6 nanocomposite verified the formation of the hexagonal phase of MoS2 and the orthorhombic one for Bi2WO6. The MoS2/Bi2WO6 nanocomposites displayed enhancemed harvest for the visible light domain and photocatalytic ability in comparison with the pristine Bi2WO6. The photocatalytic ability of MoS2/Bi2WO6 nanocomposites was assessed by the Hg(II) reduction upon visible light irradiation. The optimal 12 % MoS2/Bi2WO6 photocatalyst displayed the superior reduction of Hg(II) about 99 % after 50 min, and the rate constant reached 0.1220 min−1 according to pseudo-first-order kinetic, where it was larger three folds than pristine Bi2WO6 (0.0418 min−1). The outstanding photocatalytic ability of n-n heterojunction MoS2/Bi2WO6 photocatalyst was attributed to the huge surface area, wide photoabsorption, and high separation efficiency of photocarriers. The reduction ability of MoS2/Bi2WO6 photocatalyst remained at 94 % after five times recycle, indicating its good reusability and high stability. The obtained heterojunction with the S-scheme mechanism could inhibit the recombination of the photocarriers, thus leading to superb photocatalytic ability. This work emerges an efficient route to design S-scheme heterojunction Bi2WO6-based photocatalytic methods for energy conversion and environmental purification.

Coumarin-Based ACQ-AIE Conversion Photosensitizer for Mitochondrial Imaging and Synergistic Cancer Therapy.

Most of the traditional fluorescent molecules have the advantages of high fluorescence quantum yield, good stability, and excellent structural adjustability, but they exhibit the characteristics of fluorescence quenching caused by aggregation, which restricts their application in aqueous solutions or solids. The excellent luminescence properties and photosensitive potential of aggregation-induced emission (AIE) materials in a condensed state have made them widely concerned in the scientific research field, so it is very challenging to regulate the transformation of traditional aggregation-caused quenching (ACQ) fluorophores into AIE fluorophores. In this study, the traditional coumarin fluorophore was used as a matrix. After conjugating the triphenylamine AIE group, the triphenylphosphine cation was linked through the alkyl chain to obtain a molecular probe NCTPP with excellent AIE characteristic, water solubility, mitochondrial green light imaging, chemotherapy and photodynamic therapy capabilities. As far as we know, it was the first time that the photosensitivity of coumarin fluorescent molecules was imparted by the ACQ-AIE conversion method.

Improvement and effectiveness analysis of dynamic/static imbibition experiments.

In low-permeability fractured reservoirs, there is a generalized fluid displacement between the replacement fluid in the fracture and the matrix crude oil. This imbibition behavior plays a crucial role in the development of this type of reservoir. The experimental devices for studying static imbibition behavior are generally susceptible to air pollution on the surface of the test core and a long testing period; the experimental devices for studying dynamic imbibition behavior are generally unable to eliminate the driving action. A dual-purpose experimental setup and an experimental method for dynamic or static imbibition that can avoid the above defects were designed. A method of fracture fluid flow rate calculation and motor speed conversion is proposed, and the method is used to assist in setting the parameters of dynamic imbibition experiments. The device was applied to compare the experimental effects with the static imbibition bottle and the dynamic replacement imbibition, respectively, and the effect of fracture width on the dynamic imbibition of repellent oil was investigated. The results show that: the static imbibition recovery rate of the dynamic/static imbibition experimental device is 1.55 percentage points higher than that of the imbibition bottle; the dynamic imbibition recovery rate is 3-6 percentage points lower than that of the driving dynamic imbibition method, and it can reflect the influence of a single flow rate condition on the imbibition; imbibition in low-permeability fractured reservoirs is more likely to take place in the fracture in the interval of 50-100 μm in the width.

A “performance-inheritance” strategy for achieving hydrophilic/hydrophobic fluorescent biomass-derived carbon dots through simple solvothermal treatments

It remains a challenge to obtain hydrophilic/hydrophobic materials with promising biocompatibility and environmental compatibility by simple methods. Herein, we designed a “performance-inheritance” strategy and for the first time constructed hydrophilic/hydrophobic fluorescent spirulina-derived carbon dots (CDs) through simple solvothermal treatments. The contact angle of hydrophobic CDs with near-infrared (NIR) fluorescence is 110°, while hydrophilic CDs with blue fluorescence is 19° We further revealed that the NIR luminescence is derived from the chlorophyll structure, while blue fluorescence is from the surface states. Based on the hydrophilicity/hydrophobicity of CDs, a ratiometric sensor was constructed to detect water content in organic solutions. In addition, CDs with NIR emission have low toxicity and good biocompatibility, making them efficient probes for bioimaging. This strategy provides a simple method for the high value-added conversion of algae and a new perspective for the “design-preparation-application” of biomass-derived CDs with specific properties.

Insect Production: A Circular Economy Strategy in Iceland

In this review, the multifaceted issue of food security is addressed, emphasizing the need for innovative and culturally appropriate solutions. Exploring insect livestock farming emerges as a potential remedy, offering a pathway to alleviate food insecurity and promote food sovereignty, particularly when integrated with social acceptability. Stakeholder engagement on both production and consumption fronts, coupled with sustained support, is vital for successful implementation. The expanding landscape of commercial insect farming in the West prompts questions about its broader scalability and equitable deployment, especially for vulnerable populations. Existing research gaps underscore the need for a coordinated effort across international, national, and legal frameworks to effectively integrate insect farming into existing agricultural systems. In this review, we have delved into the industrial-scale production processes of mealworms and black soldier flies (BSFs), known for their high protein content and organic waste conversion, covering small and industrial cultivation methods, offering insights into mealworm production life cycles, innovative rearing systems, and harvesting techniques. This review concludes with climate-specific recommendations for insect facilities, stressing the importance of sustainable practices, continuous research and development, effective market strategies and economic feasibilities in Iceland. In the context of escalating demand for sustainable protein sources, industrial-scale insect production emerges as a pivotal player in addressing global food security challenges.

BIM and IFC Data Readiness for AI Integration in the Construction Industry: A Review Approach

Building Information Modelling (BIM) has been increasingly integrated with Artificial Intelligence (AI) solutions to automate building construction processes. However, the methods for effectively transforming data from BIM formats, such as Industry Foundation Classes (IFC), into formats suitable for AI applications still need to be explored. This paper conducts a Systematic Literature Review (SLR) following the PRISMA guidelines to analyse current data preparation approaches in BIM applications. The goal is to identify the most suitable methods for AI integration by reviewing current data preparation practices in BIM applications. The review included a total of 93 articles from SCOPUS and WoS. The results include eight common data types, two data management frameworks, and four primary data conversion methods. Further analysis identified three barriers: first, the IFC format’s lack of support for time-series data; second, limitations in extracting geometric information from BIM models; and third, the absence of established toolchains to convert IFC files into usable formats. Based on the evidence, the data readiness is at an intermediate level. This research may serve as a guideline for future studies to address the limitations in data preparation within BIM for AI integration.

Phase-Specific Immobilization of Phospholipase D as an Efficient Pickering Emulsion Interfacial Catalyst for Converting Antarctic Krill Oil Phospholipid.

Phosphatidylserine (PS), a rare phospholipid in Antarctic krill oil (AKO) critical for brain development, can be produced from the abundant phosphatidylcholine (PC) using phospholipase D (PLD) in Pickering emulsion interfacial catalysis (PIC) systems. However, the exposure of PLD to organic solvent around the emulsion interface diminished PLD activity, limiting the conversion efficiency of PS. In this study, we proposed a strategy to fabricate a PIC system with high efficiency and stability by immobilizing PLD in a specific phase on the emulsion interface, based on investigating the effect of the interfacial microenvironment on PLD activity. Janus-poly(acrylic acid)/polystyrene (JPP) and Janus-polyethylenimine/octadecane (JPO) particles were fabricated as carriers to realize the specific-phase immobilization of PLD. The highest activity was observed when PLD was immobilized on the hydrophilic side of JPP (PLD@JPP(W)), 1.9-fold that of free PLD. The catalytic efficiency of PLD@JPP(W) was 1.7-fold that of free PLD, confirmed by the kcat/Km value enhancement. Immobilization on the hydrophilic side also enhanced the thermal stability of PLD. The half-lives of PLD were extended from 4 to 36 h at 40 °C and from 6 to 28 days at 4 °C. Importantly, PLD@JPP(W) showed excellent catalytic efficiency as a PIC system, achieving a PS productivity of 93% within a short time of 2 h at an enzyme dosage of 0.05 mg. PLD@JPP(W) exhibited a 3.6 times higher yield than free PLD in the production of PS from PC rich in Antarctic krill oil. The strategy in this work could also be applied to other lipases, providing a promising method for the efficient conversion of functional lipids.