Low Energy Consumption Process Research Articles

Hanbury Brown and Twiss-type optical secret sharing

Towards growing challenges of information security and authentication, various optical techniques based on holography, diffraction, interference, metasurfaces, etc., deliver promising solutions with low energy consumption and parallel high-speed information processing. Here, we report on a new dimension–second-order coherence found in the well-known Hanbury Brown and Twiss (HBT) effect–for performing optical authentication and secret sharing. We develop a method to generate a pair of correlated phase-only masks, each of which is distributed to a shareholder and can produce a specific pattern as authentication under coherent illumination, while two secret images are encrypted in the mutual information of two masks. By combining two masks in two configurations, two secret images can be extracted through spatially cascaded display under coherent illumination and intensity correlation under incoherent illumination, respectively. Conspicuously, two extremes of coherence–spatially coherent or incoherent–will enable the encoding and decoding of two different images with the same phase masks, indicating that the first-order and second-order coherence can be two independent channels for optical cryptography just like other degrees of freedom of light (e.g., polarization). Moreover, we demonstrate a polarization-multiplexing scheme to achieve polarization-selective HBT-type optically secret-sharing with increased capacity, and this type of polarization-phase masks can be readily replaced with metasurfaces.

Pulsed Electric Fields Effects on Proteins: Extraction, Structural Modification, and Enhancing Enzymatic Activity.

Pulsed electric field (PEF) is an innovative physical method for food processing characterized by low energy consumption and short processing time. This technology represents a sustainable procedure to extend food shelf-life, enhance mass transfer, or modify food structure. The main mechanism of action of PEF for food processing is the increment of the permeability of the cell membranes by electroporation. However, it has also been shown that PEF may modify the technological and functional properties of proteins. Generating a high-intensity electric field necessitates the flow of an electric current that may have side effects such as electrochemical reactions and temperature increments due to the Joule effect that may affect food components such as proteins. This article presents a critical review of the knowledge on the extraction of proteins assisted by PEF and the impact of these treatments on protein composition, structure, and functionality. The required research for understanding what happens to a protein when it is under the action of a high-intensity electric field and to know if the mechanism of action of PEF on proteins is different from thermal or electrochemical effects is underlying.

Opto-intelligence spectrometer using diffractive neural networks.

Spectral reconstruction, critical for understanding sample composition, is extensively applied in fields like remote sensing, geology, and medical imaging. However, existing spectral reconstruction methods require bulky equipment or complex electronic reconstruction algorithms, which limit the system's performance and applications. This paper presents a novel flexible all-optical opto-intelligence spectrometer, termed OIS, using a diffractive neural network for high-precision spectral reconstruction, featuring low energy consumption and light-speed processing. Simulation experiments indicate that the OIS is able to achieve high-precision spectral reconstruction under spatially coherent and incoherent light sources without relying on any complex electronic algorithms, and integration with a simplified electrical calibration module can further improve the performance of OIS. To demonstrate the robustness of OIS, spectral reconstruction was also successfully conducted on real-world datasets. Our work provides a valuable reference for using diffractive neural networks in spectral interaction and perception, contributing to ongoing developments in photonic computing and machine learning.

Study on the characteristics and kinetics of microwave hot air combined drying of peanut pods

Drying is an important means to maintain the quality of peanut pods and reduce the risk of mildew. Microwave hot air combined drying is renowned for its efficacy, low-energy consumption, and superior processing quality, rendering it suitable for peanut pod drying. However, its efficacy hinges greatly on various parameters. To enhance drying efficiency and quality, the drying kinetics of peanut pods using microwave hot air combined drying equipment were investigated. Varying microwave power (1.2 kW, 2.4 kW, 3.6 kW), hot air temperature (30 °C, 35 °C, 40 °C, 45 °C), air velocity (0.4 m/s, 0.7 m/s, 1 m/s), and microwave radiation time (4 min, 6 min) were examined. Results indicated a decline in drying time, moisture ratio, and drying rate with increasing microwave power, hot air temperature, air velocity, and microwave radiation time. Peroxide and acid values complied with national standards. The Verma model exhibited optimal fitting. At 45 °C, peanut pod moisture diffusion coefficient was 3.022 × 10−9 m2 s−1, specific energy consumption at 30 °C was 5302 kJ/kg, and thermal efficiency was 42.6 %. The synergistic drying of peanut pods by microwave and hot air has a high moisture diffusion coefficient and thermal efficiency. The kinetic and energy analysis of the drying process can furnish some theoretical foundation for subsequent microwave hot air drying and equipment parameter adjustment.

Preparation of integrated carbon fiber stitched fabric reinforced (SiBCN) ceramic/resin double-layered composites for ablation resistance, thermal insulation and compression resistance performance

This paper reports a novel integrated carbon fiber fabric reinforced ceramic/resin double-layered composite. The composites were prepared by a low energy consumption process of stratified impregnate pyrolysis. The double-layered composites consist of an amorphous SiBCN ceramic upper layer and a SiBCN resin bottom layer. In the ablation experiment, the temperature of the composite material's ablated surface exceeded 1850 °C, while the temperature of the backside remained below 70 °C within 60 s of ablation. Even after 90 s of ablation, the backside temperature was still significantly lower than the theoretical application temperature of SiBCN resin. The ablated surface has no visible pits or cracks. The maximum mass ablation rate and line ablation rate were −0.01259 mg/s and 0.000933 mm/s, respectively. High-density amorphous SiBCN ceramic layer effectively play the role of high temperature and ablation resistance. In addition, the compressive strengths of the composites before and after ablation were above 340 MPa. Integrated composites that combine anti-ablation, insulation, and compression resistance have potential in aerospace applications.

Separation performance of graphene oxide nanofiltration membrane intercalated by MWCNTs and α -Fe2O3 nanoparticles

Nanofiltration (NF) technology is used in the field of water treatment due to its advantages of low energy consumption, high efficiency, and simple process flow. However, the problems of membrane fouling and trade-off (i.e., high flux with low rejection or high rejection with low flux) exist in NF technology, which limit its wide-scale popularization and application. The emphasis of this work is to improve the performance of graphene oxide (GO)-based NF membranes. Multi-walled carbon nanotubes (MWCNTs) and α-Fe2O3 were selected to modify the GO-based membrane by expanding the interlayer spacing and enhancing its antifouling and rejection abilities. Our composite membranes exhibit an increased interlayer spacing of 0.787 nm to 1.1 nm, achieving a high pure water permeation flux of 138.96 Lm−2 h−1, as well as satisfactory rejection rates for salts and dyes (Na2SO4, NaCl, MgCl2, Congo red, and methylene blue). Additionally, the membranes exhibit a relatively good antifouling property. After five cycles of rejection tests, the flux and rejection rate could be recovered to 90 % from 80 % with a 4-h irradiation under visible light. This study provides valuable insights into the development of high-efficiency and advanced NF membranes.

Integrate-and-fire circuit for converting analog signals to spikes using phase encoding * *The authors would like to thank Alexander Lenz and Susanne Junghans for their expertise and input, which was very valuable for implementing and testing the designed circuit. The authors would also like to thank the Technical University of Dresden for granting them access to the SpiNNaker 2 chip

Processing sensor data with spiking neural networks on digital neuromorphic chips requires converting continuous analog signals into spike pulses. Two strategies are promising for achieving low energy consumption and fast processing speeds in end-to-end neuromorphic applications. First, to directly encode analog signals to spikes to bypass the need for an analog-to-digital converter. Second, to use temporal encoding techniques to maximize the spike sparsity, which is a crucial parameter for fast and efficient neuromorphic processing. In this work, we propose an adaptive control of the refractory period of the leaky integrate-and-fire (LIF) neuron model for encoding continuous analog signals into a train of time-coded spikes. The LIF-based encoder generates phase-encoded spikes that are compatible with digital hardware. We implemented the neuron model on a physical circuit and tested it with different electric signals. A digital neuromorphic chip processed the generated spike trains and computed the signal’s frequency spectrum using a spiking version of the Fourier transform. We tested the prototype circuit on electric signals up to 1 kHz. Thus, we provide an end-to-end neuromorphic application that generates the frequency spectrum of an electric signal without the need for an ADC or a digital signal processing algorithm.

Fiber-Reinforced Alkali-Activated Cements from Ceramic Waste and Ladle Furnace Slag without Thermal Curing

Alkaline-activated cement, as an alternative to conventional portland cement, is being increasingly studied due to its environmental advantages and engineering properties. However, research on the feasibility of using both uncommon precursors and curing at ambient temperature is still limited. This study aims to investigate the potential of ceramic wastes, specifically from brick and tile production and ladle furnace slag, as precursors in alkaline activated cement reinforced with polyacrylonitrile fibers cured at 20°C. Sodium silicate, in solution form, was used to activate the precursors, and three different fiber contents were tested, namely 0%, 0.5%, and 1%, by volume. Physical properties, such as capillarity and porosity, were assessed. Moreover, the mechanical behavior was thoroughly characterized by uniaxial compressive, flexural, and elasticity modulus tests. In addition, a thorough microstructural characterization, including scanning electron microscopy, X-ray energy dispersive analyzer, X-ray diffraction, and Fourier transform infrared spectroscopy was conducted at 14, 28, and 90 days. The results revealed that environmentally friendly alkali-activated binders were produced from wastes with limited industrial recycling possibilities. The mixture with 0.5% fibers was the one that presented better results, i.e., a flexural strength of 8.84 N/mm2 and compressive strength of ∼29 MPa at 90 days. The mechanical performance of this material is relevant, especially considering that a relatively low curing temperature was applied. The results also showed that calcium aluminum silicate hydrate (C-A-S-H) was detected as the main reaction product.Practical ApplicationsAlkali-activated cement has been identified as a potential alternative to traditional portland cement due to advantages such as the reduction of CO2 emissions to the atmosphere, and the conservation of natural resources, because wastes can be transformed into useful products. All over the world, ceramic materials are widely used in different types of construction, and significant amount (between 30% and 45%), end up as waste. Therefore, this study aims to show the possibility of reusing ceramic waste for the development of a fiber-reinforced alkaline activated cement composite with acceptable physical and mechanical properties that allow it to be used in non-structural applications; for example, bricks, tiles, partition walls, and other building materials. It also is a low-energy consumption process, because curing can be done at ambient temperatures. Finally, the obtained results, e.g., flexural strength of 8.84 N/mm2 and compressive strength of 29 MPa, open the door for several applications in the construction industry.

Bipolar Membrane Electrodialysis for Cleaner Production of Diprotic Malic Acid: Separation Mechanism and Performance Evaluation.

Bipolar membrane electrodialysis (BMED) is a promising process for the cleaner production of organic acid. In this study, the separation mechanism of BMED with different cell configurations, i.e., BP-A, BP-A-C, and BP-C (BP, bipolar membrane; A, anion exchange membrane; C, cation exchange membrane), to produce diprotic malic acid from sodium malate was compared in consideration of the conversion ratio, current efficiency and energy consumption. Additionally, the current density and feed concentration were investigated to optimize the BMED performance. Results indicate that the conversion ratio follows BP-C > BP-A-C > BP-A, the current efficiency follows BP-A-C > BP-C > BP-A, and the energy consumption follows BP-C < BP-A-C < BP-A. For the optimized BP-C configuration, the current density was optimized as 40 mA/cm2 in consideration of low total process cost; high feed concentration (0.5-1.0 mol/L) is more feasible to produce diprotic malic acid due to the high conversion ratio (73.4-76.2%), high current efficiency (88.6-90.7%), low energy consumption (0.66-0.71 kWh/kg) and low process cost (0.58-0.59 USD/kg). Moreover, a high concentration of by-product NaOH (1.3497 mol/L) can be directly recycled to the upstream process. Therefore, BMED is a cleaner, high-efficient, low energy consumption and environmentally friendly process to produce diprotic malic acid.

High efficient separation of H2/CH4 using ZIF-8/glycol-water slurry: Process modelling and multi-objective optimization

Hydrogen (H2) is expected to play a vital role in future global energy system. The efficient and low-energy consumption process for H2/CH4 separation from hydrogen rich industrial off-gas is still a key challenge. The absorption-adsorption process for H2/CH4 separation using ZIF-8/glycol-water slurry is a promising alternative technique due to its high separation efficiency, mild operation conditions and continuous operation mode. We proposed two process configurations: a decompression desorption process A to obtain 99.5 mol% H2; and a process B combined with decompression and H2 stripping desorption to attain 99.99 mol% H2. The detailed process modelling and multiple objective optimizations for two processes are conducted to determine optimal operation conditions, stream characteristics, and unit energy requirements. Results show that the H2 recovery ratio and total unit energy consumption reaches 99.70% and 0.3876 kW·h/Nm3 for Process A; 99.47% and 0.4608 kW·h/Nm3 for Process B, respectively. It indicates the novel process can simultaneously achieve high purity and high H2 recovery with low energy consumption.

An electric-field-driven ferroelectric nanodomain structure and its multilevel data storage application.

Solid-state multilevel data storage devices based on ferroelectric materials possess significant potential for use as artificial synapses in building biomimetic neural networks with low energy consumption and efficient data processing capabilities. To enable multilevel data storage, precise control of the ferroelectric domain through voltage pulses is essential. In this study, we investigate the manipulation of ferroelectric nanodomain structures using a nanotip and demonstrate their evolution under controlled application of electric pulses with varying strength and duration. The results highlight the differences in electric-field-driven ferroelectric nanodomain structures between (001)-/(101)- and (111)-oriented PbZr0.2Ti0.8O3 thin films. Interestingly, the latter exhibits highly anisotropic domain wall motion characteristics. The (111)-oriented PbZr0.2Ti0.8O3/SrRuO3 heterostructure demonstrates the best performance in increasing the domain radius with respect to electric pulse strength and duration. It shows at least three resistance states with a high switching ratio, making it a promising candidate for multilevel data storage applications. Additionally, the self-reversal rates of upward and downward domains differ and must be considered in designing and implementing multilevel data storage systems for stability and effectiveness. These findings reveal the potential of ferroelectric nanodomain structures for data storage and pave the way for nanotip-controlled artificial synapses.

Designing Efficient Flash-Calcined Sediment-Based Ecobinders.

To ensure the optimum navigation of boats and protection against flooding, waterways and ports are regularly dredged. The volume of dredged materials represents 56 million m3 in France and 300 million m3 in Europe. These materials show a high potential for a use as supplementary cementitious material (SCM). In this paper, sediments treated by the flash calcination method (STFC), which is based on a low-energy consumption process, are utilized as a mineral admixture in a cementitious matrix. The results of the physical, chemical, and mineralogical characterization prove that this heat treatment has an interesting impact on the final properties of the sediments. Mortars based on the flash-calcined product have comparable mechanical properties to control mortar. For a substitution rate below 10%, the performances are even equivalent to a metakaolin (MK80)-based mortar. Calorimetry testing demonstrated that calcined materials also improve hydration processes in the cement matrixes by generating additional heat release due to sediment pozzolanic activity. Across this study, it is shown that waste material including sediment can be transformed after optimized heat treatment into a valuable resource for the building and infrastructure sector.

Novel mesoporous cupric oxide-based biomaterial: An efficient nanocatalyst toward catalytic reduction of emerging contaminants in the wastewater

The present study reports on catalytic reduction of emerging water contaminants under ambient conditions by employing green, cost-effective, sustainable, efficient, and easy-recoverable nanocatalyst. Initially, spherical nano-CuO particles with good distribution were bio-synthesized using agricultural wastes in a facile, simple, and low-energy consumption process. After the characterization, the catalytic performance of the bio-synthesized CuO particles was examined for removal of p-nitrophenol, Cr(VI), and methylene blue dye from aquatic systems. Nano-CuO particles successfully reduced 90–98% of pollutants in a short time (4 s–8 min). In the next attempt, to improve the stability, separation, and reusability of nano-CuO powder, and also, to prevent secondary contamination by powdery form, composite microbeads based on natural polymer substrate (Na-alginate) as a gelling agent and CaCl2 as a complexing agent were developed by dropping method. The reduction rate of pollutants was fast, and pollutants were removed in less than 25 min. Conversion percentages for Ca-alginate/CuO microbeads in removing pollutants were obtained at 90–98%. The catalytic degradation kinetics data were best fit to the pseudo-first-order model with good correlation coefficients (R2 > 98). Besides, the catalytic activity of the prepared nanocatalyst remained almost unaltered for 10 consecutive cycles. Easy fabrication, effortless separation, large-scale application, excellent performance, and durability make the nanocatalyst and the procedure sustainable and economical.

Prelithiation-derived hierarchical TiO2 sieve with metal-organic framework gate for selective lithium recovery

Sustainable lithium supply significantly matters the healthy development of electric vehicles markets. Selective adsorption plays an important role in aqueous lithium recovery due to low energy consumption and easy processing. We here report a prelithiation concept to generate active Li+ sites in TiO2 forming LixTiO2 at a mild temperature for lithium recovery. A hollow protonated LixTiO2 matrix with nanosheets surface was built to provide abundant active sites for specific Li+ capture with fast matter transfer. And a biomimetic metal–organic framework (ZIF-8) gate layer, acting as Li+ channel, was engineered to regulate cation solvation structure for selective transport of Li+. Consequently, the resultant TiO2-based hybrid lithium-ion sieve demonstrates fast and homogenous Li+ chemisorption with a high Li+ uptake capacity (∼14 mg g−1 for 24 h at pH = 12), high Li+ selectivity against competing cations in both simulated and natural brine, and acceptable reusability in simulated brine, indicating further application potential.

Mixed-ligand metal–organic frameworks with coordinatively un-saturated Co(II) and Ni(II) sites for regenerable O2-selective ad-sorption over N2

For air separation, the separation method relying on adsorbents has attracted wide attention as a low energy consumption process, and the development of O2-selective adsorbents is of great significance. Metal-organic frameworks with coordinatively unsaturated transition metal sites have great potential in O2-selective adsorption, but most of them cannot be completely regenerated at ambient temperature or can only be effective at very low temperatures. Herein, we report two mixed-ligand metal–organic framework adsorbents [M(AIP)(BPY)0.5·H2O]n·2nH2O with coordinatively unsaturated cobalt(II) and nickel(II) sites, which can preferentially adsorb O2 versus N2, and their IAST O2/N2 selectivities are both significantly greater than 1 at 25 °C. These materials exhibited excellent stability and had no loss of adsorption capacities even after immersion in water for 7 days. More importantly, O2 adsorption–desorption cycle experiments showed that these adsorbents can be completely regenerated at ambient temperature after adsorbing O2, and the breakthrough experiments further confirmed their dynamic O2/N2 separation potential and regeneration ability. The results of theoretical calculations suggested that the interactions between adsorbents and O2 are stronger than those of N2, and they have relatively obvious differences in the N2 and O2 interaction energies. This work provides inspirations for searching for metal–organic frameworks that can selectively adsorb O2 at ambient temperature.

Performance analysis of a novel thermal energy storage integrated solar dryer for drying of coconuts.

The drying of food products is an essential step in the preservation of crops and agricultural by-products that serve as raw materials for numerous end applications. Solar drying with phase change materials (PCMs) is an efficient low-energy consumption process in the post-reaping stage, reducing food deterioration. A customized solar dryer setup was assembled using Cudappah (black) stones as the base of the drying chamber to facilitate the absorption of solar energy on its surface. The organic paraffin wax, with a melting point of 60 ℃, was used as PCM in the solar dryer. The novelty of the study is the application of a PCM in a solar dryer to improve the effectiveness of drying and decrease the absolute drying period and the microbial content in the dried coconut. The study compared the drying characteristics between open sun drying and solar drying without and with PCM (100 and 200g). The fabricated setup was utilised for drying coconut using a PCM-based solar drying method. The coconut was dried from an initial moisture content of 55.5% to a final moisture content of about 9%. The prototype dryer model minimized the use of the workforce, avoided improper drying, and decreased the absolute drying time. A total plate count (TPC) test was conducted to characterize the microbial content in the dried coconut. The microbial count decreased with the use of 200-g PCM as the use of PCM retained the heat for a longer time in the chamber. The drying time of coconut decreased by about 28 and 52h on using 100 and 200g of PCM, respectively, compared to open sun drying. The sensory characteristics like colour, taste, flavour, quality, and texture of the solar-dried coconut sample were superior to the sun-dried coconut sample.

Development and Implementation of Smart Water Metering System based on Lora Technology

The article presents an overview of traditional water meters in Vietnam, digitizing metrology technologies and wireless data transmission technology for data collection and user applications in smart water metering systems. After that, it is proposed to design a smart wireless water meter module. This paper focuses on designing and implementing a smart water meter to re-use traditional mechanical water meters by designing a smart water metering module attached to the existing meter. This way, it eliminates the costs of investing in flow water meter and influences the old water meter infrastructure system. The contribution of this paper is threefold: (i) Firstly, it proposes wireless data transmission and digitizing metrology technologies suitable for water metering systems in Viet Nam. (ii) Secondly, the proposed smart water meter module designs include hardware, firmwave, and plastic cover. There are two experimental prototypes of the module is introduced in this paper (iii) Lastly, The paper provides a water metering management software model for smart cities. And the overall systems of the proposed platform were built to verify the presented design. To reduce the amount of water leaking or users hacking from outside the meter in the measurement results, the article proposes to design features to alert about: abnormal flow, strong magnetic field influence, and equipment cover being removed. The experimental verification was designed with the Actaris water meter using Hall technology to digitize data and the Itron water meter with digitizing technology using the LC sensor. Besides, the Lora wireless network system is proposed and deployed to verify the water metering management with the advantages of low energy consumption, high security, and strict authentication process. Actual results for the laboratory environment and residential areas show that signal loss (RSSI) and signal noise (SNR) is within the allowable range. In addition, the packet loss rate &lt;1% and average power consumption meter &lt;50uA. Water metering management software is presented to verify the smart city service system.

Manipulating the film morphology evolution toward green solvent‐processed perovskite solar cells

AbstractHigh‐performance perovskite solar cells (PVSCs) with low energy consumption and green processing are highly desired, but constrained by the difficulty in morphology control and the poor understanding on morphology evolution mechanisms. To address this issue, here we studied the effect of antisolvents on the perovskite film formation. We found that both the antisolvents and the perovskite composition affect the perovskite film morphology greatly via influencing the intermediate phase, and different perovskite compositions require different antisolvents to reach the optimal morphology. This provides the opportunity to achieve high‐performance PVSCs with green antisolvent, that is, isopropanol (iPA) by changing the perovskite compositions, and leads to a power conversion efficiency (PCE) of 21.50% for PVSCs based on MA0.6FA0.4PbI3. Further, we fabricated “fully green” PVSCs with all layers prepared by green solvents, and the optimal PCE can reach 19%, which represents the highest among PVSCs with full‐green processing. This work provides insight into the perovskite morphology evolution and paves the way toward “green” processing PVSCs.

Near-Infrared Laser Direct Writing of Conductive Patterns on the Surface of Carbon Nanotube Polymer Nanocomposites.

Near-infrared (NIR) laser annealing is used to write conductive patterns on the surface of polypropylene/multi-walled carbon nanotube nanocomposite (PP/MWCNT) plates. Before irradiation, the surface of the nanocomposite is not conductive due to the partial alignment of the MWCNT, which occurs during injection molding. We observe a significant decrease in the surface sheet resistance using NIR laser irradiation, which we explain by a randomization of the orientation of MWCNTs in the PP matrix melt by NIR laser irradiation. After only 5 s of irradiation, the sheet resistance of PP/MWCNTs, annealed with a laser at a power density of 7 W/cm2, decreases by more than 4 decades from ∼100 MΩ/sq to ∼1 kΩ/sq. Polarized Raman, TEM, and SEM are used to investigate the changes in the sheet resistance and confirm the physico-chemical processes involved. This allows direct writing of conductive patterns using a NIR laser on the surface of nanocomposite polymer substrates, with the advantages of a fast, easy, and low-energy consumption process.

Highly selective conversion of methane to ethanol over CuFe2O4-carbon nanotube catalysts at low temperature

Conversion of methane into liquid alcohol such as ethanol at low temperature in a straight, selective and low energy consumption process remains a topic of intense scientific research but a great challenge. In this work, CuFe2O4/CNT composite is successfully synthesized via a facile co-reduction method and used as catalysts to selectively oxidize methane. At a low temperature of 150 °C, methane is directly converted to ethanol in a single process on the as-prepared CuFe2O4/CNT composite with high selectivity. A mechanism is also proposed for the significant methane selective oxidation performance of the CuFe2O4/CNT composite catalysts.