Irradiation Intensity Research Articles

Rapid 3D printing of unlayered, tough epoxy-alcohol resins with late gel points via dual-color curing technology.

Additive manufacturing technologies and, in particular, vat photopolymerization promise complex structures that can be made in a fast and easy fashion for highly individualized products. While the technology has upheld this promise many times already, some polymers are still out of reach or at least problematic to print reliably. High-performance epoxide-based resins, which are regulated by chain transfer via multifunctional alcohols, are a typical example of resins with late gel points, which require long irradiation times and high light intensities to print. Therefore, we have developed a dual-colour printing approach where rapid radical curing of a soft, wide-meshed polymer network facilitates fast and easy 3D structuring of the subsequently slow curing step-growth formulation at an orthogonal initiation-wavelength regime. Thereby the methacrylate system acts as a scaffold for an uncured epoxide alcohol system during the printing process, which is then cured with UV light post-printing. This way tough alcohol-regulated epoxy-systems become accessible to vat photopolymerization achieving outstanding high-resolution 3D printed parts without significant layering effects. The demonstrated wide-meshed matrix-assisted printing approach has the potential to make a multitude of slowly curing resins accessible to vat photopolymerization techniques, at low irradiation intensities and high curing speeds.

The Incorporation of CsCu2I3 Nanocrystals into Polydimethylsiloxane Matrix for X‐ and γ‐Ray Scintillators

CsCu2I3 CsCu2I3 lead‐free nanocrystals (NCs) have recently garnered significant interest for their outstanding optical and scintillation characteristics, particularly for X‐ray imaging applications. In this study, CsCu2I3 NCs are mixed with polydimethylsiloxane (PDMS) resin in the form of a pellet to protect against environmental factors such as moisture. The resulting sample exhibits a light yield of up to 2 ph keV−1 and an excellent energy resolution of 13% for γ‐ray excitation at 662 keV at room temperature. Additionally, the CsCu2I3 NCs–PDMS resin shows no afterglow and has a negligible trap density. Herein, high stability at low irradiation intensities and reasonable stability at higher intensities are demonstrated. Moreover, the sample features a fast component scintillation decay times of 3.55 ns, which is slightly faster than that of (BZA)2PbBr4. This outcome possesses promising combination in designing lightweight and flexible hybrid PDMS‐based hybrid materials scintillators. These scintillation properties of CsCu2I3 NCs–PDMS can be a promising candidate for affordable and flexible screens for X‐ and γ‐ray photon‐counting computed tomography.

Aqueous mixtures of deep eutectic solvents: Tuning the reaction medium and photocatalyst for highly selective amine oxidation

Harvesting light as a source of energy for driving chemical processes is an important aspect of tacking the looming energy crisis. The challenge lies in making the process sustainable while retaining the efficiency and selectivity. In this work, deep eutectic solvents and their aqueous mixtures are used to replace acetonitrile as the reaction medium for the photocatalyzed amine oxidation. It is observed that the use of deep eutectic solvents as reaction media leads to > 90 % conversion but presents issues with efficient workup due to high viscosity. The use of water a cosolvent mitigates the issue. Further modification of the catalyst surface with alizarin enables the use of higher water content (in a 1:1 ratio) and leads to high conversion (>90%) at one-tenth of irradiation intensity. The high yield and selectivity eliminate the need for tedious purification steps to isolate the product. Control experiments indicate cooperative contributions by TiO2, TEMPO and alizarin as mechanistic factors responsible for the enhanced reactivity.

Freeform mirror design for beam shaping by a combined approach using Poisson-based grid optimization and a discrete cosine transform

In this study, we have designed freeform mirrors capable of transforming uniform irradiance distribution into complicated irradiance distribution. The design methodology incorporates two key algorithms: Poisson-based grid optimization and a discrete cosine transform (DCT). The grids on the target plane were optimized using Poisson-based grid optimization while maintaining uniformity on the incident plane. By obtaining grids for both input and target planes, we derived the normal vector field and utilized the DCT to calculate the sags of the freeform surface. Several examples have been devised to substantiate the validity of the approach. For Case 1 and Case 2, the results demonstrate that these freeform surfaces produce high-contrast and complicated irradiance maps with a notable proportion exceeding 4:1 in terms of irradiation intensity ratio between the graphic area and the background. In Case 2, when compared to the prescribed irradiance distribution, the normalized cross correlation values for generated irradiance distributions by the freeform mirror, both with and without sag error, are 94% and 96%, respectively. Furthermore, Cases 3 and 4 demonstrate that incident beams with complex irradiance distributions can be transformed into uniform irradiance profiles by the freeform mirror designed using the proposed method, achieving uniformity levels of 93% and 95%, respectively. It is noteworthy that the incident beam aperture in Case 4 exhibits an elliptical shape.

Role of the Sn-TiO2/Ti-SnO2 Heterojunction in Enhancing the Photocatalytic Oxidation of Arsenite (AsIII) through the Promotion of Charge Carrier Lifetime.

This study proposes the heterojunction photocatalyst, Sn-doped TiO2/Ti-doped SnO2 (herein named Sn1Ti1O2), as a promising alternative to pure TiO2. Sn1Ti1O2 demonstrates improved light harvesting efficiency over TiO2 by generating longer-lived electron-hole (eCB--hVB+) pairs, while also displaying a smaller band gap compared to pure TiO2. Consequently, we show that it is a promising candidate for the photocatalytic oxidation (PCO) of AsIII to the less toxic and more readily removable form AsV. Transient absorption spectroscopy (TAS) shows increased eCB--hVB+ recombination half-lives from ∼0.5 ms in TiO2 to ∼1 ms in Sn1Ti1O2. The initial transient absorption signal for Sn1Ti1O2 is twice that of pure TiO2, suggesting early time scale (pre-μs) suppression of (eCB--hVB+) recombination. Moreover, TAS showed that Sn1Ti1O2 possesses more reactive charge carriers than TiO2 under reactions with chemical scavengers. For the first time, TAS experiments were conducted using both a colorimetric indicator (molybdate) and AsIII to determine the PCO kinetics from AsIII to AsV. The TAS molybdate─AsIII experiment results indicate that the oxidation process occurs on the sub-microsecond time scale, with a notable increase in absorption at ∼700 nm, providing evidence of the formation of the AsV─molybdate blue complex. PCO experiments showed that •OH radicals played the predominant role during PCO, followed by superoxide radicals (O2•─). •OH scavengers including isopropanol, rebamipide anhydrous, and dimethyl sulfoxide (DMSO) reduce the PCO yield of AsIII to 21, 30, and 23%, respectively. While O2•─ scavengers including superoxide dismutase (SOD) and p-benzoquinone suppressed the PCO yield of AsIII to a lesser degree, with yields of 35 and 49% seen, respectively. The effects of irradiance intensity, salinity, pH, AsIII concentration, and photocatalyst mass on both the quantum efficiency (QE) and PCO kinetics were investigated. The Sn1Ti1O2 catalyst exhibited effective recyclability, validating its economical reusability. Overall, the study demonstrates the potential of the Sn1Ti1O2 heterojunction photocatalyst for the PCO of AsIII to the less toxic AsV in water treatment, showing faster oxidation kinetics and improved charge separation compared to pure TiO2 as proven by TAS.

Study of Cooling Characteristics of Axisymmetric Tail Nozzle

In order to reduce the infrared radiation intensity of supersonic tail nozzles and in response to the increasingly severe battlefield infrared environment, simulations were conducted on axisymmetric expanding tail nozzles to study the effects of air, liquid nitrogen, and dry ice cold flows at different flow rates on the nozzle wall temperature. The results show that when the dry ice flow rate is increased by 1 kg/s, the maximum temperature of the wall surface in the expansion section decreases by about 40 K. At a cold flow rate of 5% in the 0° detection direction, the intensity of infrared radiation was reduced by 20.8% for the liquid nitrogen cold flow and 26.3% for the dry ice cold flow, compared to the cold flow of injected air. The IR suppression of the tail nozzle was significant in the range from α = 0 to 50°. Compared to cooling air, the maximum IR radiation intensity was reduced by 26.5% for dry ice and 20.4% for liquid nitrogen. When the flow rate of the injected cold stream was increased by 4%, the intensity of the infrared radiation from the nozzle was reduced by 52.6%, 55.8%, and 66.2% for the injected air, liquid nitrogen, and dry ice cold streams, respectively.

Investigation into the feasibility of a lightguide based prevention of catheterassociated urinary tract infections (CAUTI)

Abstract Catheter-associated urinary tract infections are among the most common hospital-acquired infections and all previous measures to reduce their incidence have been less successful. Therefore, the present study investigates an approach based on the antimicrobial effect of visible light. The radiation of a violet or blue LED is guided via optical fiber with a diffuser tip into a catheter surrounded by an E. coli suspension (phosphate buffered saline or urine) in a simple urinary tract model. The irradiation led to bacterial reductions of up to several orders of magnitude that depended on various parameters. Violet light had a stronger antimicrobial effect than blue light, even in the experiments with urine, which absorbs violet light more strongly than blue light. An increase in irradiation intensity led to a greater reduction in bacteria. Human cells are not expected to be damaged by this irradiation. Therefore, the application of violet light to prevent catheter-associated urinary tract infections seems particularly promising but should be tested on even more realistic models in the future, which should not only include planktonic cells but also biofilms.

PHOTOVOLTAIC GENERATION FORECASTING MODELS: CONCEPTUAL ENSEMBLE ARCHITECTURES

The decisions regarding power regulation, energy resource planning, and integrating “green” energy into the electrical grid hinge on precise probabilistic forecasts. One of the potential strategies to enhance forecast accuracy is the utilization of ensemble forecasting methods. They represent an approach where multiple models collaborate to achieve superior results compared to what a single model could produce independently. These methods can be categorized into two main categories: competitive and collaborative ensembles. Competitive ensembles harness the diversity of parameters and data to create a rich pool of base models. This approach may encompass statistical analysis, noise filtering, and anomaly elimination. On the other hand, collaborative ensembles rely on the interaction among models to achieve better outcomes. These methods encompass strategies such as weighted predictions, voting, aggregation, and a combination of model results. The research of ensemble forecasting methods in the context of photovoltaic generation is highly relevant, as solar energy represents a crucial source of renewable energy. Accurate predictions of solar energy production address the challenges related to the efficient utilization of photovoltaic panels and their integration into the overall energy system. This paper investigates conceptual ensemble architectures for photovoltaic energy forecasting. These architectures encompass various methods of aggregating base models within an ensemble, allowing for the consideration of different aspects and peculiarities of solar data, such as solar irradiation intensity, meteorological conditions, geographic factors, and more. These conceptual models are developed based on well-established statistical, machine learning, and artificial intelligence methods. Therefore, this paper provides an overview of ensemble forecasting methods for renewable energy, covering competitive and collaborative ensembles, as well as developing conceptual models for solar energy forecasting. This work aims to elevate the accuracy and efficiency of forecasts in the realm of renewable energy, representing a significant step in the advancement of sustainable and environmentally friendly energy production. Keywords: probabilistic solar forecasting, ensemble model, forecast combination, competitive ensembles, collaborative ensembles, conceptual models.

A novel 3D opto-electro-thermal coupling numerical model for photovoltaic/thermal systems

Photovoltaic/thermal (PV/T) systems offer a promising solution for enhancing energy conversion performance by capturing waste heat and reducing the operating temperature of photovoltaic cells. The performance of these PV/T systems could be further optimized by numerical simulation. However, currently reported PV/T models utilize simplified models and and fail to consider the electro-thermal coupling in local areas of solar cells, thereby inadequately representing the underlying physical mechanisms. To address this issue, a novel opto-electro-thermal coupling numerical model of perovskite PV/T systems based on drift–diffusion equations is developed in this work. This model enables the investigation of the energy conversion mechanism of optical, electrical and thermal energy at grid cell level. Building on the developed model, the energy conversion performance at system level under various operational conditions is analyzed via a modified weighted total efficiency evaluation indicator. The results indicate that: the total efficiency is significantly compromised by elevated environmental temperature, with an efficiency loss of 8.45 % observed when the temperature increases by 40 °C. Meanwhile, as irradiation intensity rises, the efficiency gained from utilizing waste heat would become increasingly significant in PV/T systems. More importantly, the optimal flow rate for various irradiation intensities is also derived. This work could offer theoretical guidance for investigating more comprehensive energy conversion mechanisms and optimizing energy conversion performance for PV/T systems.

Development of a novel power generation model for bifacial photovoltaic modules based on dynamic bifaciality

The bifaciality is significantly affected by the irradiance intensity and non-uniformity of rear irradiance (NUF). Therefore, it would result in large errors with a static bifaciality when simulating the dynamic power generation of bifacial photovoltaic (bPV) modules. In the study, a novel dynamic bifaciality was proposed, considering the above two factors simultaneously. Firstly, the fundamental bifaciality under different irradiance intensities was obtained via current–voltage (I-V) characteristic tests. Secondly, a three-dimensional (3D) view factor model was established to study the effects of the installation parameters, solar irradiance, and solar position on NUF. A regression model was built up to predict NUF with a goodness of fit (R2) of 0.914. Thirdly, an electrical model for bPV modules was established considering the non-uniform distribution of rear irradiance. A bifaciality correction factor (CF) was proposed to quantify the influence of NUF on bifaciality. Moreover, an empirical formula between CF and NUF was fitted with a R2 of 0.98. Finally, the dynamic bifaciality was obtained by correcting the fundamental bifaciality with CF, based on which a novel power generation model of bPV modules was developed. Compared to the outdoor experiments, it was found that when NUF was 14.6%, the daily mean relative errors (MAEs) of the novel model and the traditional method were 1.14% and 6.07%, respectively. When NUF was 23.2%, the daily MAEs were 1.40% and 8.10%, respectively. This indicates that under different conditions, the novel model could reduce the relative error of bPV power simulation by about 80% compared to the traditional method.

Effects of electron beam irradiation on the sensory qualities and bioactive compounds of broccoli sprout juice

This study investigates the effects of electron beam irradiation at varying doses on the bioactive compounds and sensory qualities and of broccoli sprout juice (BSJ). A comprehensive analysis of volatile flavor components using GC-IMS and GC–MS identified 49 compounds, including esters, aldehydes, and olefins. Notably, the sulforaphane content exhibited a strong negative correlation with irradiation intensity (R2 = 0.9596), which is critical for predicting the impact of irradiation dose on sulforaphane degradation. Statistical analysis confirmed that 34 volatile compounds, like methyl acetate, 2-methylbutanal, hexanoic acid ethyl ester, etc., exhibited significant difference in different irradiation doses groups (P < 0.05). Sensory evaluation revealed that 6 kGy was the optimal irradiation dose, enhancing the sweetness and mushroom aroma while reducing undesirable spicy flavors. These findings provide valuable insights for balancing preservation techniques, sensory qualities, and nutritional integrity in BSJ, offering potential applications in both food and medicinal industries.

Fabrication of Near-Infrared Photodetectors with Ag-Cu-in-Te Nanorod Films as an Active Layer

Semiconductor nanocrystals (NCs) have been intensively investigated for the application to photovoltaics, light-emitting diodes, and biological markers, because of their tunable light absorption and excellent light emission properties. In our previous paper[1], we reported the synthesis of near-IR-responsive AgInTe2 NCs by a colloidal method, in which the obtained NCs showed a relatively sharp photoluminescence (PL) peak at 1100 nm with a quantum yield of 47%. In addition, solid solution NCs of ZnTe and AgInTe2 were found to have tunable energy gap (Eg ) in the wide near-IR region from 1.2 to 1.6 eV by controlling their chemical composition[2]. Here, we explore CuInTe2, an I-III-VI semiconductor with the Eg of 0.86 eV, aiming to achieve Eg control in a narrower range from 0.86 to 1.2 eV by forming solid solutions with AgInTe2. This paper reports the solution-phase synthesis of Ag(1-x)Cu x InTe2 (ACITe) solid solution NCs and evaluates their optical detection capabilities for near-IR light. We demonstrate that the particle size and composition of ACITe NCs can be modified to fine tune their photochemical properties.Metal acetates of Ag, Cu, and In were added to 1-dodecanethiol in a test tube and stirred at room temperature under a nitrogen atmosphere. Trioctylphosphine telluride (TOP-Te) was added to the mixture and heated at 180°C for 10 min with vigorous stirring. The resulting ACITe NCs were isolated and purified, followed by dissolving in octane. A seed-mediated crystal growth method was used to control the particle size: The thus-obtained ACITe NCs were added as a seed and further heated with 1-dodecanethiol containing corresponding metal acetates and TOP-Te. The size of NCs was controlled by changing the amount of ACITe seeds added.ACITe NCs were rod-shaped particles, regardless of their chemical composition, Cu/(Ag+Cu) (= x). The XRD pattern of NCs prepared with x= 0 was attributed to hexagonal AgInTe2 crystal structure. As the Cu fraction increased, i.e. the x value increased, each peak in the XRD pattern of ACITe NCs was shifted to a higher angle, approaching that of tetragonal CuInTe2 crystal structure. These results indicated that the thus-obtained NCs were composed of a solid solution between AgInTe2 and CuInTe2, the composition of which was controlled by the Cu/Au ratio in the precursors. With the elongation of the rod NCs, the XRD peak around 25° corresponding to the hexagonal (002) plane became narrowed, indicating that ACITe NCs were grown along with the c-axis of hexagonal crystal structure. The onset wavelength of the absorption spectra of ACITe NCs gradually shifted from 1070 nm (x = 0, AgInTe2) to 1200 nm (x=1, CuInTe2) with increasing the x value, indicating that E g of ACITe NCs was tuned in the near-IR region by controlling their composition. The obtained ACITe NCs (x= 0.5) with average rod lengths of 13 nm, 23 nm, and 27 nm (denoted as ACITe(13 nm), ACITe(23 nm), and ACITe(27 nm), respectively) were used to fabricate a photodetector, in which the QDs were spin-coated on a comb-shaped electrode. We evaluated the photoresponse at the applied voltage of +5.0 V under a dark condition or under the irradiation of near-IR light (880 nm) with various intensities. Regardless of the light intensity, the devices prepared with ACITe(23 nm) and ACITe(27 nm) exhibited approximately 5-7 times higher sensitivity compared to that with ACITe(13 nm), indicating that the crystal morphology of semiconductor NCs significantly affected their performance of near-IR light detection. Moreover, the photosensitivity at the irradiation intensity of 20 µW cm-2 was 20.3 A W-1 for the device with ACITe(27 nm), which was higher than that reported for a photodetector fabricated with conventional near-IR-responsive PbSe NCs (0.66 A W-1; 1064 nm, 10 µW cm-2) [3]. References (1) T. Kameyama, et al., Nanoscale, 8, 5435 (2016). (2) T. Kameyama, et al., J. Mater. Chem. C, 6, 2034 (2018). (3) A. A. Babaev, et al., Nanomaterials, 13, 3051 (2023).

Sustainable desalination through hybrid photovoltaic/thermal membrane distillation: Development of an off-grid prototype

Global freshwater scarcity is a critical challenge, particularly severe in remote Australian communities where seawater intrusion and aquifer salinisation exacerbate the need for alternative water resources. Conventional desalination technologies are energy-intensive and unsuitable for rural areas. This study introduces a novel, off-grid, sustainable desalination solution utilising solar-integrated membrane distillation (MD) technology. An innovative, stand-alone prototype combining a hybrid photovoltaic/thermal (PV/T) system with direct contact MD (DCMD) has been designed and developed. This fully integrated PV/T collector efficiently supplies the thermal and electrical energy required for the MD process. The photovoltaic panel generates the necessary electrical energy, while the heat from the PV panel warms the MD system’s feed solution, enhancing overall efficiency through the solar cell cooling effect. In addition, an innovative fan-cooled radiator equipped with two DC fans with a low power consumption rating was designed and customized to be applied as MD system cooling medium within the outdoor setting. The concept development and feasibility of the system are explored in detail through a comprehensive experimental investigation employing an innovative and practical approach to design and examine the integrated hybrid solar MD unit. This unique system was designed, constructed, and tested under dynamic outdoor conditions, during the summer season in Melbourne, to assess the integration strategy and evaluate its long-term operational performance. The performance of the integrated PV/T-MD system was evaluated using two commercial hydrophobic membranes with different pore sizes under various outdoor conditions and PV/T fluid flow rates. Key performance metrics analysed include solar irradiance intensity, temperature profiles of the PV/T panel and MD module, power, current and voltage profiles of the unit components, permeate flux, specific water productivity (SWP) and the thermal (ηthermPV/T) and electrical (ηelecPV/T) efficiencies, along with the gained output ratio (GOR). Comprehensive experimental assessments in indoor and outdoor settings were undertaken to confirm the technical viability of the system. The study demonstrates the feasibility of such systems through real-world trials and addresses key challenges in energy efficiency and internal heat recovery. The experimental trials demonstrated permeate flux values ranging between 8–16 kg/m2h outdoors, compared to 22–30 kg/m2h indoors, reflecting the impact of fluctuating environmental conditions. The system’s power consumption was measured 130–140 W, about one-third of the PV/T power rating. The maximum power generation reached 280 W in battery charging mode. achieving a maximum ηthermPV/T of 20 % and an ηelecPV/T of 18 %. Additionally, the cooling effect of the PV/T panel resulted in a 1.5–2 °C temperature reduction, improving electrical power output by 0.8–1.2 %. The findings highlight the significant potential of the system in providing reliable and efficient freshwater production in remote, off-grid communities, offering a scalable solution to address global water scarcity challenges.

Electrical characteristics of photovoltaic (PV) solar panel and hybrid PV/thermal (PV/T) solar panel

Solar collectors and photovoltaic (PV) solar panels can convert solar radiation into heat and electrical energy. A hybrid PV/thermal (PV/T) solar panel was tested in this study. The hybrid PV/T solar panel was tested using a spiral absorber and water flow levels range from 0.01 kg/s to 0.03 kg/s. As a result, with variable water flow rates and irradiation intensity of 700 and 900 W/m2, the efficiency of hybrid PV/T solar panels varied. The highest electrical efficiency attained was 4.06% in hybrid PV/T solar panels at 900 W/m2 with 0.025 kg/s of mass flow while 3.65% by PV solar panels. In addition, plotted current-voltage and power-voltage curves were used to show the electrical properties of the solar PV panels and hybrid PV/T solar panels.

Microbial Contamination and Sterilization Methods in an Air Circulation-Type Geothermal Ventilation System

A simulated system was created to evaluate an air circulation-type geothermal ventilation system, focusing on measuring microbial contamination levels on the surface of the heat exchange unit. Additionally, this study examined sterilization methods using UV lamps on the surface of the heat exchanger. The fungal concentration on the surface of the heat exchanger showed a tendency to increase over time. Although direct comparison is challenging due to the varying concentrations of outdoor air fungi at different measurement times, the surface fungal concentration was highest at a minimum airflow rate of 150 m3/h compared to other conditions. However, since the adhesion of contaminants from outdoor air to the surface of the heat exchanger is influenced not only by airflow but also by outdoor temperature and relative humidity conditions, future research needs to consider these factors. According to the ATP measurement results, microbial contamination was evaluated as “slightly dirty” after 24 h and “dirty” after 48 h of operating the experimental apparatus. Therefore, it is advisable to clean the internal surfaces of the geothermal ventilation system every 1–2 days. The results of the sterilization experiments using UV lamps indicated that irradiation for approximately 30 min inactivated 94.5%-to-96.1% of microorganisms derived from outdoor air. However, since the sterilization dose varies depending on the type of microorganism, it is necessary to determine the optimal irradiation time based on the target microorganisms and the UV lamp’s irradiation intensity.

Multimaterial Thermoset Synthesis: Switching Polymerization Mechanism with Light Dosage.

The synthesis of polymeric thermoset materials with spatially controlled physical properties using readily available resins is a grand challenge. To address this challenge, we developed a photoinitiated polymerization method that enables the spatial switching of radical and cationic polymerizations by controlling the dosage of monochromatic light. This method, which we call Switching Polymerizations by Light Titration (SPLiT), leverages the use of substoichiometric amounts of a photobuffer in combination with traditional photoacid generators. Upon exposure to a low dose of light, the photobuffer inhibits the cationic polymerization, while radical polymerization is initiated. With an increased light dosage, the buffer system saturates, leading to the formation of a strong acid that initiates a cationic polymerization of the dormant monomer. Applying this strategy, patterning is achieved by spatially varying light dosage via irradiation time or intensity allowing for simple construction of multimaterial thermosets. Importantly, by the addition of an inexpensive photobuffer, such as tetrabutylammonium chloride, commercially available resins can be implemented in grayscale vat photopolymerization 3D printing to prepare sophisticated multimodulus constructs.

Synergistic singlet oxygen and UV irradiation for efficient intracellular ARGs removal via peroxymonosulfate/catalytic membrane-UV system

The eliminate of antibiotic resistance genes (ARGs) is pivotal in mitigating the proliferation of antibiotic resistance. In this study, a PMS/CM-UV system was engineered, combining a Co3O4-modified carbon nanotubes catalytic membrane with LED-UV lamps, to effectively eliminate intracellular ARGs (iARGs). Leveraging the synergistic effect of singlet oxygen (1O2) and UV irradiation, this process requires only a brief hydraulic retention time of a few minutes and standard UV disinfection irradiation intensity. The cellular physiological function and transcriptomic analysis indicated that reactive oxygen species (ROS) and UV irradiation compromised the cell membrane integrity of E. coli MG1655-SD, as indicated by the down-regulation of the feoB gene, leading to an increased concentration of 1O2 within the intracellular environment. The synergistic effect of 1O2 and UV irradiation resulted in the down-regulation of btuE, thereby curtailing the SOS and oxidative stress responses. Additionally, UV irradiation down-regulated ftsK, uvrB, and uvrA genes, involved in DNA replication, damage site recognition, and self-repair. These processes collectively contribute to the oxidative damage of iARGs by 1O2 before their release into the extracellular environment. This work provided a strategy to develop advanced oxidation disinfection technology aimed at ARGs removal.

Double-pulse laser peening as a surface enhancement technology

In this paper, we discuss double-pulse laser peening (DPLP) as surface enhancement technology. Although single-pulse laser peening (SPLP) has yielded excellent results across various applications, its processing performance and efficiency are limited. The DPLP technique involves two laser pulses with a controlled irradiation interval and intensity, enhancing laser absorption through the plasma plume and generating high-amplitude laser-induced shock waves. This study involved conducting DPLP experiments on stainless steel, comparing the outcomes with those of conventional SPLP to assess DPLP’s functionality. After the initial prepulse irradiation, the subsequent main pulse was timed and irradiated onto the stainless steel. We evaluated the surface hardness to ascertain the impact of laser peening. The findings indicated that the surface hardness achieved with DPLP was up to 64% greater than that with SPLP. Additionally, the surface hardness achieved through DPLP depended on the delay time between the pulses and the intensity of the initial prepulse. These findings suggest that DPLP can significantly enhance surface hardness, providing a potential pathway for improving material performance in various industrial applications. Furthermore, simulation experiments of DPLP were performed using a one-dimensional simulation code that calculates the laser-matter interaction during the peening process. The pressure profiles generated by the simulation closely matched the experimentally derived hardness profiles, confirming the simulation’s ability to predict the mechanical effects induced by DPLP on the target sample and assist in further optimization of the DPLP process.

A New Grey Prediction Model and Its Application in Renewable Energy Consumption

Renewable energy is an energy resource that can be used continuously. At present, international oil prices continue to rise, the problem of global climate change is becoming increasingly prominent, and renewable energy and clean energy have ushered in a new round of development opportunities. Based on the new gray prediction model, this paper forecasts the consumption of renewable energy and further analyzes the sustainable development of renewable energy. In this paper, the combinatorial optimization method of cumulative order, background value coefficient, and initial conditions, parameter optimization combination, parameter combinatorial optimization process of the gray prediction model, and parameter optimization mechanism based on the PSO algorithm are proposed, and the reduction error analysis is carried out. The consumption of wind power and photovoltaic renewable energy is forecasted, and three different forecasting methods as exponential smoothing method, time series analysis method, and new gray forecasting method are compared, and the wind speed, irradiation intensity, and load are forecasted by these three different forecasting methods. Compared with the time series analysis method and the exponential smoothing method, the RMSE of the new grey prediction method is reduced by 127.12% and 160.59%, and the error rate is reduced by 3.16% and 4%, respectively. Based on the consumption forecast of renewable energy, this paper analyzes its sustainability from three directions economy, resource supply, and environment, and finally gives energy policy recommendations.

Optimization of Hydrogen Production System Performance Using Photovoltaic/Thermal-Coupled PEM

A proton exchange membrane electrolyzer can effectively utilize the electricity generated by intermittent solar power. Different methods of generating electricity may have different efficiencies and hydrogen production rates. Two coupled systems, namely, PV/T- and CPV/T-coupling PEMEC, respectively, are presented and compared in this study. A maximum power point tracking algorithm for the photovoltaic system is employed, and simulations are conducted based on the solar irradiation intensity and ambient temperature of a specific location on a particular day. The simulation results indicate that the hydrogen production is relatively high between 11:00 and 16:00, with a peak between 12:00 and 13:00. The maximum hydrogen production rate is 99.11 g/s and 29.02 g/s for the CPV/T-PEM and PV/T-PEM systems. The maximum energy efficiency of hydrogen production in CPV/T-PEM and PV/T-PEM systems is 66.7% and 70.6%. Under conditions of high solar irradiation intensity and ambient temperature, the system demonstrates higher total efficiency and greater hydrogen production. The CPV/T-PEM system achieves a maximum hydrogen production rate of 2240.41 kg/d, with a standard coal saving rate of 15.5 tons/day and a CO2 reduction rate of 38.0 tons/day. Compared to the PV/T-PEM system, the CPV/T-PEM system exhibits a higher hydrogen production rate. These findings provide valuable insights into the engineering application of photovoltaic/thermal-coupled hydrogen production technology and contribute to the advancement of this field.