Irradiation Energy Research Articles

Dose and compositional dependence of irradiation-induced property change in FeCr

Ferritic/martensitic steels will be used as structural components in next generation nuclear reactors. Their successful operation relies on an understanding of irradiation-induced defect behaviour in the material. In this study, Fe and FeCr alloys (3–12%Cr) were irradiated with 20 MeV Fe-ions at 313 K to doses ranging between 0.00008 dpa to 6.0 dpa. This dose range covers six orders of magnitude, spanning low, transition, and high dose regimes. Lattice strain and hardness in the irradiated material were characterised with micro-beam Laue X-ray diffraction and nanoindentation, respectively.Irradiation hardening was observed even at very low doses (0.00008 dpa) and showed a monotonic increase with dose up to 6.0 dpa. Lattice strain measurements of samples at 0.0008 dpa allow the calculation of equivalent Frenkel pair densities and corrections to the Norgett-Robinson-Torrens (NRT) model for Fe and FeCr alloys at low dose. NRT efficiency for FeCr is 0.2, which agrees with literature values for high irradiation energy. Lattice strain increases with dose up to 0.8 dpa and then decreases when the damage dose is further increased. The strains measured in this study are lower and peak at a larger dose than predicted by atomistic simulations. This difference can be explained by taking temperature and impurities into account.

Temperature dependence of atomic‑oxygen irradiation mechanism of hydrogenated diamond-like carbon film

Hydrogenated diamond-like carbon (H-DLC) films are effective lubricants for aerospace moving parts, but the service of H-DLC is severely threatened by atomic oxygen (AO) in low Earth orbit (LEO). The interaction between AO and H-DLC strongly depends on ambient temperature; however, the interactive mechanism has not been fully understood. In this study, we report different temperature dependences of AO irradiation behavior on H-DLC film. Under the AO irradiation with low energy, the increase in ambient temperature can only increase the surfacial oxidation; while, the effect of temperature under high AO irradiation energy is more significant, resulting in the transition from the surficial oxidation to continuous carbon removal. Subsequent analysis of the AO trajectories shows that the different repulsion mechanisms of the H-DLC surface against high and low energy AO result in the different temperature dependence. For AO incident with low energy, the incident AO cannot touch the H-DLC surface anymore due to the repulsion of the surfacial oxygen in the later irradiation stage. Nevertheless, high energy AO could overcome the repulsion of oxidized surface to contact the H-DLC surface, the increase in temperature can continuously promote the AO irradiation on the H-DLC surface.

Skin wound healing in diabetic rat model using low-dose photodynamic therapy.

Chronic wound is one of the major challenges in medicine and imposes a heavy financial burden on the healthcare of different countries. Diabetic foot ulcers as one of the important examples for chronic wounds can lead to lower limb amputation, disability, and death in diabetics. In this regard, novel technology with low side effects got attention in recent years. Low-dose photodynamic therapy (LDPDT) is one of the noninvasive techniques that can be considered for wound healing in diabetic wounds. In this experiment, we aim to study the effect of LDPDT on diabetic rats' wound healing and compare it to healthy rats. In this in vitro experimental study, 32 male rats were used. Rats in both normal and diabetic (streptozotocin injection) groups after being wounded (two wounds [0.8×0.8cm]) on the back of each rat were randomly divided into four groups, including the control group (without treatment), radiation-only (660nm-1 J/cm2 ) group, 5-ALA-only (1µg/mL) group, and LDPDT-recipient group. The procedure has been done for 2days, and at the end of Days 3, 7, 14, and 21, the wound sample was sent to the histopathology laboratory, and the wound size and tissue indices in these groups were evaluated by histology and microscopy techniques. The impact of low concentrations of 5-ALA and low irradiation energy density in both normal and diabetic rats were positive, which accelerated the wound-healing process as seen in the histology study. In diabetic rats treated with only radiation and LDPDT, the process of epithelial regeneration, collagen production, reduction of mast cells, and production of follicles was more as compared to the normal group. The results suggest that LDPDT can have a positive impact on the diabetic rat model wound healing.

Variations in irradiation energy and rose bengal concentration for photodynamic antimicrobial therapy of fungal keratitis isolates.

The purpose is to assess the efficacy of rose bengal photodynamic antimicrobial therapy (PDAT) using different irradiation energy levels and photosensitizer concentrations for the inhibition of fungal keratitis isolates. Seven different fungi (Aspergillus fumigatus, Candida albicans, Curvularia lunata, Fusarium keratoplasticum, Fusarium solani, Paecilomyces variotii, and Pseudallescheria boydii) were isolated from patients with confirmed infectious keratitis. Experiments were performed in triplicate with suspensions of each fungus exposed to different PDAT parameters including a control, green light exposure of 5.4J/cm2, 2.7J/cm2 (continuous and pulsed), and 1.8J/cm2 and rose bengal concentrations of 0.1%, 0.05%, and 0.01%. Plates were photographed 72h after experimentation, and analysis was performed to assess fungal growth inhibition. PDAT using 5.4J/cm2 of irradiation and 0.1% rose bengal completely inhibited growth of five of the seven fungal species. Candida albicans and Fusarium keratoplasticum were the most susceptible organisms, with growth inhibited with the lowest fluence and minimum rose bengal concentration. Fusarium solani, Pseudallescheria boydii, and Paecilomyces variotii were inhibited by lower light exposures and photosensitizer concentrations. Aspergillus fumigatus and Curvularia lunata were not inhibited by any PDAT parameters tested. Continuous and pulsed irradiation using 2.7J/cm2 produced similar results. Rose bengal PDAT successfully inhibits the in vitro growth of five fungi known to cause infectious keratitis. Differences in growth inhibition of the various fungi to multiple PDAT parameters suggest that susceptibilities to PDAT are unique among fungal species. These findings support modifying PDAT parameters based on the infectious etiology.

In Vivo Evaluation of Corneal Biomechanics Following Cross-Linking Surgeries Using Optical Coherence Elastography in a Rabbit Model of Keratoconus.

Validation of the feasibility of novel acoustic radiation force optical coherence elastography (ARF-OCE) for the evaluation of biomechanical enhancement of the in vivo model of keratoconus by clinical cross-linking (CXL) surgery. Twelve in vivo rabbit corneas were randomly divided into two groups. Both groups were treated with collagenase type II, and a keratoconus model was obtained. Then, the two groups were treated with CXL procedures with different irradiation energy of 15 J and 30 J (CXL-15 J and CXL-30 J, respectively). An ARF-OCE probe with an ultrasmall ultrasound transducer was used to detect the biomechanical properties of cornea. An antisymmetric Lamb wave model was combined with the frequency dispersion relationship to achieve depth-resolved elastography. Compared with the phase velocity of the Lamb wave in healthy corneas (approximately 3.96 ± 0.27 m/s), the phase velocity of the Lamb wave was lower in the keratoconus region (P < 0.05), with an average value of 3.12 ± 0.12 m/s. Moreover, the corneal stiffness increased after CXL treatment (P < 0.05), and the average phase velocity of the Lamb wave was 4.3 ± 0.19 m/s and 4.54 ± 0.13 m/s after CXL-15 J and CXL-30 J treatment. The Young's moduli of the keratoconus regions were significantly lower than the healthy corneas. Moreover, the Young's modulus of the keratoconus regions was significantly higher after CXL-30 J treatment than after CXL-15 J treatment. We demonstrated that the ARF-OCE technique has great potential in screening keratoconus and guiding clinical CXL treatment. This work accelerates the clinical translation of OCE systems using ultrasmall ultrasound transducers and is used to guide CXL procedures.

Study of infrared quenching in silicide-silicon-silicide structures

Infrared quenching (IR Q) in silicide-silicon-silicide and silicide-silicon-metal structures has been studied. Silicides are obtained through the process of diffusion doping of silicon with manganese atoms. Infrared quenching was detected in the irradiation energy range of 0.31-0.75 eV when illuminated with local light hv≥Eg. Attachment levels for electrons were found: Ec-0.31 eV, Ec-0.38 eV, Ec-0.51 eV. The long-wave limit of photoconductivity (PC) was established to be 0.38 eV by studying the spectral characteristics of silicide-silicon-silicide structures.

Effect of Al related chemical short-range order on the irradiation resistance of Al0.5CoCrFeNi multi-principal element alloy: A molecular dynamics simulation

Multi-principal element alloys (MPEAs) have received much attention for future nuclear materials due to their exceptional radiation resistance. This work investigated the effect of Al related chemical short-range ordered (CSRO) which caused by its large atomic size in face-centered cubic (FCC) Al0.5CoCrFeNi alloy on its irradiation damage behavior through mixed molecular dynamics and Monte Carlo simulations. The calculation results indicate that the CSRO structure effectively suppresses the generation of point defects during irradiation in Al0.5CoCrFeNi alloy, and this inhibitory effect increases with increasing irradiation energy. The enhanced radiation resistance of CSRO alloy is attributed to the high vacancy formation energy, interstitial atom formation energy, and vacancy migration energy barrier of Al. Moreover, the Al atoms in CSRO alloy can also act as defect barriers, preventing the migration of vacancy defects; The formation energy of interstitial atoms in the CSRO alloy exhibits a strong element dependence, and there is a significant difference in the formation energy of interstitial atoms between different points, which strengthens the hysteresis diffusion effect of MPEAs and further enhances the radiation resistance of MPEAs.

Localized Photodynamic Therapy Using a Chlorin e6-Embedded Silicone-Covered Self-Expandable Metallic Stent as a Palliative Treatment for Malignant Esophageal Strictures.

Localized photodynamic therapy (PDT) uses a polymeric-photosensitizer (PS)-embedded, covered self-expandable metallic stent (SEMS). PDT is minimally invasive and a noteworthy potential alternative for treating esophageal strictures, where surgery is not a viable option. However, preclinical evidence is insufficient, and optimized irradiation energy dose ranges for localized PDT are unclear. Herein, we validated the irradiation energy doses of the SEMS (embedded in a PS using chlorin e6 [Ce6] and covered in silicone) and PDT-induced tissue changes in a rat esophagus. Cytotoxicity and phototoxicity in the Ce6-embedded SEMS piece with laser irradiation were significantly higher than that of the silicone-covered SEMS with or without laser and the Ce6-embedded silicone-covered SEMS without laser groups (all p < 0.001). Moreover, surface morphology, atomic changes, and homogeneous coverage of the Ce6-embedded silicone-covered membrane were confirmed. The ablation range of the porcine liver was proportionally increased with the irradiation dose (all p < 0.001). The ablation region was identified at different irradiation energy doses of 50, 100, 200, and 400 J/cm2. The in vivo study in the rat esophagus comprised a control group and 100, 200, and 400 J/cm2 energy-dose groups. Finally, histology and immunohistochemistry (TUNEL and Ki67) confirmed that the optimized Ce6-embedded silicone-covered SEMS with selected irradiation energy doses (200 and 400 J/cm2) effectively damaged the esophageal tissue without ductal perforation. The polymeric PS-embedded silicone-covered SEMS can be easily placed via a minimally invasive approach and represents a promising new approach for the palliative treatment of malignant esophageal strictures.

Intense pulsed light annealing of solution-based indium–gallium–zinc–oxide semiconductors with printed Ag source and drain electrodes for bottom gate thin film transistors

In this study, an intense pulsed light (IPL) annealing process for a printed multi-layered indium–gallium–zinc–oxide (IGZO) and silver (Ag) electrode structure was developed for a high performance all-printed inorganic thin film transistor (TFT). Through a solution process using IGZO precursor and Ag ink, the bottom gate structure TFT was fabricated. The spin coating method was used to form the IGZO semiconductor layer on a heavily-doped silicon wafer covered with thermally grown silicon dioxide. The annealing process of the IGZO layer utilized an optimized IPL irradiation process. The Ag inks were printed on the IGZO layer by screen printing to form the source and drain (S/D) pattern. This S/D pattern was dried by near infrared radiation (NIR) and the dried S/D pattern was sintered with intense pulsed light by varying the irradiation energy. The performances of the all-printed TFT such as the field effect mobility and on–off ratio electrical transfer properties were measured by a parameter analyzer. The interfacial analysis including the contact resistance and cross-sectional microstructure analysis is essential because diffusion phenomenon can occur during the annealing and sintering process. Consequently, this TFT device showed noteworthy performance (field effect mobility: 7.96 cm2/V s, on/off ratio: 107). This is similar performance compared to a conventional TFT, which is expected to open a new path in the printed metal oxide-based TFT field.

Effect of depth-absorbed dose distribution on the flexural modulus of carbon fiber–reinforced plastics in a radiation environment in radio-astronomical satellite orbit

Carbon fiber–reinforced polymers (CFRP) are used as structural materials for spacecraft due to their excellent physical properties. However, exposure in space to environmental factors, such as radiation, ultraviolet radiation, and thermal cycling, would alter these properties. Therefore, in order to ensure the safety and reliability of the spacecraft and the feasibility of the mission, it is necessary to evaluate the material’s space-environment resistance.The space environment consists of various types of energy and radiation, resulting in a non-uniform depth-absorbed dose distribution. This means that the absorbed dose is significantly higher at the surface of the material and lower with depth. However, reproducing this distribution in a ground-based test facility that typically uses a single energy irradiation is challenging. To overcome this challenge in ground-based testing, it is recommended that multiple radiation types and energies be irradiated to simulate the depth-absorbed dose distribution in a real space environment. However, there is a lack of understanding about the agreement between the depth-absorbed dose distribution obtained in real space environments and in ground-simulated tests. Additionally, the degree to which each depth region of the absorbed dose distribution affects material degradation is unknown. Hence, a faithful reproduction of the depth-absorbed dose distribution in a real space environment requires not only massive test facilities with significant financial investment but also a significant amount of time spent on irradiating those materials containing radiation that have practically no effect on material degradation.This study focused on analyzing the changes in the mechanical properties of CFRP due to radiation degradation using composite beam theory and mathematical models while considering the non-uniform depth-absorbed dose distribution in real space environments. The results of this study provide insight into which depth region of the depth-absorbed dose distribution is dominant for radiation-induced changes in mechanical properties when the CFRP plate thickness varies.

Multi-objective optimization of a cogeneration system based on solar energy for clean hydrogen, cooling, and electricity production

In an effort to encourage industries to switch from fossil fuels to renewable energy resources for supplying their energy demands, the exergy and financial aspects of a thermodynamic energy generation system were studied. The suggested system was modeled by MATLAB commercial software to assess the decision-making parameters affecting power generation, cooling capacity, and to produce hydrogen. The objective functions of this study were exergy efficiency and cost rate, while the temperatures at the inlet of the turbine and the evaporator, irradiated solar energy, mass flow rate, and surface area of the collector were the decision-making variables. The model was optimized via MOPSO and its results were compared with two widely utilized algorithms, namely NSGA-II and SPEA-II. The comparison results indicated that MOPSO surpassed other two optimization algorithm resulting in exergy efficiency and cost rate of 2.11 % and 21.14 $/h, respectively. According to this method, the optimum generated power was equal to 21.01 kW. Eventually, this system was utilized and evaluated in the city of Semnan, Iran. The performance results of the system in Semnan showed that the annual power output, taking into account the changes in radiation and ambient temperature, is between 316667.4 and 428080.5 kW. Also, the amount of hydrogen production is between 1503.66 and 1534.997 kg.

Dynamic evolution investigation on the dielectric surface charging under electron irradiation with various energy distributions

Spacecrafts face various environmental risks in their working durations, thereinto, surface charging, which may result in abnormal operation of devices, is a typical detrimental effect and deserves to be deeply investigated, especially the charging process under various electron energy distributions. In this work, aiming to reveal the evolution process of surface charging in detail, we establish an approach for predicting surface potential under electron irradiation by considering the electron emission process. Mathematical relationships for the dependence of surface charging on the secondary electron yield properties of dielectric surfaces are established. The dynamic process of surface potential evolution is calculated for MgO and Al2O3 when the energy variation of incident electrons obeys uniform distribution, Gaussian distribution, and Maxwell distribution. By analyzing the dynamic equilibrium process of electron incidence/exit in the positively/negatively charged cases, the effect of electron energy on equilibrium surface potential and equilibrium time are quantitatively calculated. It is found that the surface potential will be a dozen volts when the surface is positively charged, surface charging of this magnitude does not have a noticeable effect, and the equilibrium time is short (several microseconds). However, the surface potential may reach very high levels (thousands of volts) leading to breakdowns when the dielectric surface is negatively charged, and its equilibrium time is 3 to 4 orders of magnitude higher than the positively charged case. Via calculating the surface potential under various incident distributions, we acquire the dynamic evolution process of surface potential evolution under different energy distributions, and find its consequence shows a similar tendency for the situation of constant energy irradiation. This work digs into the mechanism of surface charging under various irradiation situations, which makes sense for further works involving surface charging induced by electron irradiation with multiple energy distributions.

Application of natural fungi in bioconversion of lignocellulosic waste to second-generation ethanol

The second generation (2G) or cellulosic ethanol can help with diversification of the use of fossil energy sources. However, as bioconversion of plant waste into 2G bioethanol requires expensive additional steps of pre-treatment/hydrolysis of lignocellulosic materials, and this technology has not yet reached the technological readiness level which would allow it to be scaled-up, this process needs more interdisciplinary and comprehensive studies. This work was aimed at experimental study of a full cycle of successive processes of pre-treatment/saccharification using cellulolytic enzymes of filamentous fungi and fermentation of obtained syrups by xylose-fermenting yeast, using selected natural microorganisms for the fungal-based bioconversion of lignocellulosic agricultural waste to 2G ethanol. Using the Plackett-Burman and Box-Behnken methods of mathematical statistics, the optimal conditions for pre-treatment and enzymatic hydrolysis of wheat straw by a hemi- and cellulolytic multi-enzyme complex of the selected fungal strain Talaromyces funiculosus UCM F-16795 were established: microwave-assisted alkali pre-treatment with sodium hydroxide (NaOH) solutions (concentration range 4.6–4.8%), and saccharification conditions of medium pH 4, temperature 40 °С, hydrolysis duration 18 hours, and dilution of culture liquid with a buffer solution 1:1. The total energy of microwave irradiation 1.2 kJ and the ratio of substrate/enzyme solution 100 mg/1 mL were used. Under optimized conditions, wheat straw hydrolysates contained 5.0–7.5 g/L of reducing sugars, which, according to HPLC assessment, contained 0.7–1.0 g/L of glucose, 2.2–2.9 g/L of xylose and 0.7–0.8 g/L cellobiose. We used the selected strain of xylose-fermenting yeast in fermentation of mixtures of the most important monosaccharides in hydrolysates, xylose and glucose, in the concentration range relevant for syrups obtained by us during the optimized saccharification of lignocellulosic substrates with T. funiculosus enzymes. Based on sequencing and phylogenetic analysis, strain UCM Y-2810 was confirmed as Scheffersomyces stipitis; its nucleotide sequences of ITS region and 28S gene rDNA were deposited in GenBank under the accession numbers OP931914 and OP931915, respectively. The ethanologenic process for S. stipitis UCM Y-2810 was studied according to Box-Behnken design, assessing ethanol concentration by gas chromatography-mass spectrometry. Yeast fermentation under static microaerophilic conditions showed a 1.5 times higher rate of bioethanol production and 1.7 times greater efficiency of ethanologenesis per yeast biomass than for submerged cultivation. Optimization of the process of ethanologenesis resulted in the maximum rate of fermentation mixture of sugars, being 11.30 ± 0.36 g/L of ethanol, with optimal values of factors: 30 g/L of xylose, 5.5 g/L of glucose and cultivation for 5.5 days. It was revealed that the tested glucose concentrations did not significantly affect the process of xylose-fermentation by yeast, and non-competitive inhibition of xylose transport by glucose into yeast cells did not occur. This study demonstrated the potential of a full cycle bioconversion of lignocellulosic waste to 2G ethanol based on use of natural fungal strains and optimization of conditions for all steps.

Synergistic green degradation of organic dyes using a BiSI catalyst: Adsorption, sonocatalysis, and photocatalysis

Water contamination due to the uncontrollable release of organic dyes into water bodies poses a serious threat to human health and ecosystems biodiversity. To address the harmful impact caused by these compounds, the development of suitable removal techniques and materials is critical. In this regard, bismuth sulfide iodide (BiSI) emerges as a promising semiconductor for wastewater treatment due to its adsorptive, sonocatalytic, and photocatalytic properties. In this study, BiSI was successfully synthesized via a wet chemistry route at moderate temperatures (120 °C) and employed as catalyst on the degradation of Rhodamine B (RhB). The main purpose addressed in this work was to achieve a synergistic effect between sono- and photocatalysis to improve the performance of the catalyst for the fast and effective removal of organic compounds. The synthesized BiSI was thoroughly characterized including its morphology, structure, surface, and optical properties. The removal capacity of RhB onto BiSI was examined under different operating conditions. BiSI catalyst demonstrated a remarkable efficiency of 95.0 % and a maximum removal capacity (Qmax) of 16.5 mg/g in just 3 min by using single sonocatalysis and photocatalysis. Besides, applying the combined sonophotocatalytic approach, the performance of the BiSI catalyst was significantly enhanced (Qmax of 28.7 mg/g), when simultaneously subjected to ultrasonic waves and ultraviolet (UV) irradiation. In addition, a possible degradation mechanism was proposed. In short, the results achieved in this study effectively demonstrated the synergistic effect when combining sono- and photocatalysis in a single method, and also the suitability of the developed BiSI catalyst for the rapid and effective degradation of RhB, employing a sustainable approach that relies on ultrasound energy and light irradiation.

Atomically dispersed Ni active sites on covalent organic frameworks for heterogeneous metallaphotocatalytic C–N cross-coupling

Covalent organic frameworks (COFs) have been acknowledged as a potential platform for heterogeneous photoredox cross-coupling due to their excellent chemical stability, admirable controllability, and extremely prominent surface area. However, synthesizing COFs with bidentate ligand units and utilizing active sites remain a grand challenge. Herein, we report a promising new family of 2,6-pyridinedicarboxaldehyde-bis-(p-aminophenylimine)-based two-dimensional (2D) COFs (PP-COF) using an amine monomer and classic tri-aldehydes. On this basis, dispersed Ni single-atom sites were immobilized on three-types imine-based bi-coordinated 2D COFs (Ni SAS-PP-COF) as heterogeneous dual photoredox catalysts for photo/Ni dual-catalyzed C–N cross-coupling between aryl bromides and alkyl/sulfo amines. Under solar energy irradiation, PP-COF could absorb light to generate electrons and holes, then the photogenerated electrons are transferred to Ni sites to reduce divalent nickel to monovalent nickel. Monovalent nickel is necessary to drive the nickel catalytic cycle. Due to the increased charge separation and abundant active sites, the state-of-the-art Ni SAS-PP-COFs catalyst achieves excellent catalytic performance in comparison of pristine PP-COF. The heterogeneous Ni SAS-PP-COF catalytic system not only confirms the prospect of COFs as potential photoredox/transition-metal dual catalysts, but also provides in-depth insights into the synthesis of functional COFs toward practical metallaphotocatalytic application.

Photodynamic Therapeutic Effect during 5-Aminolevulinic Acid-Mediated Photodynamic Diagnosis-Assisted Transurethral Resection of Bladder Tumors.

Photodynamic diagnosis-assisted transurethral resection of bladder tumors (PDD-TURBT) enhances detection of elusive lesions compared to standard white light-transurethral resection of bladder tumors (WL-TURBT). If minimal light exposure during PDD-TURBT induces the accumulation of reactive oxygen species (ROS), potentially resulting in phototoxicity in small lesions, apoptosis may be triggered in residual small tumors, allowing them to escape resection. We investigated the hypothesis of a potential photodynamic therapeutic effect during PDD-TURBT. Our study, conducted between January 2016 and December 2020 at Nara Medical University Hospital, focused on a specific emphasis on ROS production. Immunohistochemical analysis for thymidine glycol and N ε -hexanoyl-lysine was performed on 69 patients who underwent 5-aminolevulinic acid-mediated PDD-TURBT and 28 patients who underwent WL-TURBT. Additionally, we incrementally applied the minimal irradiation energy to T24 and UM-UC-3 cells treated with 5-aminolevulinic acid using instruments similar to those used in PDD-TURBT and evaluated intracellular ROS production and phototoxicity. Immunohistochemical analysis revealed a significant increase in production of thymidine glycol and N ε -hexanoyl-lysine within the PDD-TURBT group. In T24 and UM-UC-3 cells treated with 5-aminolevulinic acid and light exposure, immunofluorescent staining demonstrated a dose-dependent increase in intracellular ROS production. In addition, higher irradiation energy levels were associated with a greater increase in ROS production and phototoxicity, as well as more significant decrease in mitochondrial membrane potential. Although the irradiation energy used in PDD-TURBT did not reach the levels commonly used in photodynamic therapy, our findings support the presence of a potential cytotoxic effect on bladder lesions during PDD-TURBT.

Synthesis and performance evaluation of zinc oxide tubes/alginate microfibre composites for photodegradation of methylene blue: a novel reporting approach.

This research investigates the efficacy of zinc oxide (ZnO) tubes in decontaminating polluted water using a substrate-free hydrothermal synthesis process for ZnO tubes. The synthesized tubes are impregnated into calcium alginate microfibres, strategically chosen for their high surface area to enhance photocatalytic degradation performance and for practical handling during decontamination and subsequent collection, thereby preventing secondary contamination. Structural and morphological analyses, conducted using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD), thoroughly characterize the properties of the ZnO tubes and the composite material. The efficacy of this composite is demonstrated through the photocatalytic degradation of methylene blue (MB), as a representative organic pollutant, resulting in an 88% degradation of MB after 5 hours of irradiation by a sun simulator. Cyclic tests exhibit consistent degradation levels in the first four cycles (81-89%), followed by a subsequent decrease to 72% in the fifth cycle, coinciding with the breakdown of the microfibres into shorter fragments. Innovatively, this study introduces an approach to reporting photocatalytic degradation results, utilizing normalized pollutant concentration plotted against irradiated energy instead of time, as energy encompasses irradiated power, time, and surface area. This reveals that the 88% degradation of MB is achieved by irradiating the sample with an approximately 18 kJ. Additionally, a new metric, Specific Energy Efficiency (SEE), is introduced. It expresses the ratio of degraded pollutant mass to the mass of photocatalytic active material per unit of irradiated energy, with the maximum and cumulative SEE in this study being 1.044 μg g-1 J-1 and 326 ng g-1 J-1, respectively. This research not only contributes to the understanding of ZnO tubes' efficiency in polluted water decontamination but also introduces valuable insights for standardized reporting in photocatalytic degradation studies.

Grain Seed Treatment by a Low-Frequency Electromagnetic Field

The paper notes the potential for enhancing seed productivity through exposure to an electromagnetic field. It touches upon both theoretical and practical considerations for developing an experimental laboratory plant for pre-sowing seed treatment using a low-frequency electromagnetic field and aiming to achieve a magnetobiological effect. (Research purpose) The study aims to investigate the influence of low-frequency electromagnetic field on the composition and properties of grain seeds. (Materials and methods) Standard emitters, characterized by a magnetic induction variability of 3-75 millitesla and a radiation frequency of 1-100 Hertz, were employed to ensure the necessary treatment parameters for a batch of seeds. (Results and discussion) The study investigates the impact of magnetization on the germination process, germination energy, and the physical and chemical properties of seeds subjected to different parameters of a low-frequency electromagnetic field (ranging from 3 to 75 millitesla in magnetic induction and a radiation frequency of 10-16 Hertz).The quality of the effect was analyzed with respect to the installation parameters and seed mass, ranging from 10 to 500 grams, across various cereal crops. Subsequently, specific modes were identified, and a functional irradiation program was devised to ensure a highly effective impact on seeds, optimizing their germination, sprouting and development. (Conclusions) The impact of a low-frequency electromagnetic field on the composition and properties of grain has been studied. An experimental laboratory plant with sources of a low-frequency electromagnetic field has been developed and irradiation modes have been justified. The pre-sowing treatment of an industrial batch, the magnetobiological effect is contingent upon several factors, including the crop type and variety, activation of a biological complex in a cell that initiates the development of a seedling, seed quality and moisture content, the presence of microorganisms on the surface, pathogenic ones included, and the characteristics of irradiation sources and energy parameters. The parameters of the low-frequency electromagnetic field were determined as follows: magnetic induction ranging from 3 to 75 millitesla, a frequency 10-16 Hertz, and seed weight varying from 10 to 500 grams. These identified parameters will be applied in the development of an industrial unit designed for the preparation of seed material and enhancement of its sowing properties.

STRATEGI PENANGANAN BERCAK DAUN CURVULARIA SP. PADA PEMBIBITAN KELAPA SAWIT DI INDONESIA

Oil palm (Elaeis guineensis Jacq) is one of the plantation crops that produces vegetable oil which has become the main ingredient and leading agricultural commodity in Indonesia. The quality of oil palm seedlings is a disease attack during the seedling stage. The most common disease found in oil palm nurseries is leaf spot disease. The aim of this research is to propose strategies for handling leaf spot in oil palm nurseries in Indonesia. This research is a literature study research. The data used comes from secondary data. Data collection methods use textbooks, journals and periodical. Data analysis is carried out by reading, collecting, citing information, concluding and interpreting the results obtained through relevant study materials. The results obtained that there are several strategies that can be used to treat leaf spot in oil palm nurseries in Indonesia, i.e. by carrying out photon energy irradiation which can increase plant resistance to various types of pathogens, developing organic fertilizer formulations and using biocontrol agent which is expected to help oil palm nurseries in suppressing leaf spot disease, using fungicides to prevent resistance, taking preventive measures to reduce the risk of spot disease on oil palm leaves, carrying out conservation fertilization using S2 (385 mesh), S3 (638 mesh), and S4 (644 mesh) sachets and applying liquid smoke areca nut in suppressing the growth of Curvularia sp.

Engineering Vacancies for the Creation of Antisite Defects in Chemical Vapor Deposition Grown Monolayer MoS2 and WS2 via Proton Irradiation.

It is critical to understand the laws of quantum mechanics in transformative technologies for computation and quantum information science applications to enable the ongoing second quantum revolution calls. Recently, spin qubits based on point defects have gained great attention, since these qubits can be initiated, selectively controlled, and read out with high precision at ambient temperature. The major challenge in these systems is controllably generating multiqubit systems while properly coupling the defects. To address this issue, we began by tackling the engineering challenges these systems present and understanding the fundamentals of defects. In this regard, we controllably generate defects in MoS2 and WS2 monolayers and tune their physicochemical properties via proton irradiation. We quantitatively discovered that the proton energy could modulate the defects' density and nature; higher defect densities were seen with lower proton irradiation energies. Three distinct defect types were observed: vacancies, antisites, and adatoms. In particular, the creation and manipulation of antisite defects provides an alternative way to create and pattern spin qubits based on point defects. Our results demonstrate that altering the particle irradiation energy can regulate the formation of defects, which can be utilized to modify the properties of 2D materials and create reliable electronic devices.