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Optics Express May 2024Micro-light emitting diodes (µ-LEDs) are considered the key enabler for various high-resolution micro-display applications such as augmented reality, smartphones or...
Micro-light emitting diodes (µ-LEDs) are considered the key enabler for various high-resolution micro-display applications such as augmented reality, smartphones or head-up displays. Within this study we fabricated nitride-based µ-LED arrays in a thin film chip architecture with lateral pixel sizes down to 1 µm. A metal mirror on the p-side enhances the light outcoupling via the n-side after removal of the epitaxial growth substrate. Mounted devices with pixel sizes ranging from 1×1 to 8×8 µm were electro-optically characterized within an integrating sphere and in a goniometer system. We measure increased external quantum efficiencies on smaller devices due to a higher light extraction efficiency (LEE) as predicted by wave optical simulations. Besides this size dependence of the LEE, also the far field properties show a substantial change with pixel size. In addition, we compared µ-LEDs with 40 nm and 80 nm thick aluminium oxide around the pixel mesa. Considerably different far field patterns were observed which indicate the sensitivity of optical properties to any design changes for tiny µ-LEDs. The experimentally obtained radiation behavior could be reasonably predicted by finite-difference time-domain simulations. This clearly reveals the importance of understanding and modeling wave optical effects inside µ-LED devices and the resulting impact on their optical performance.
PubMed: 38858942
DOI: 10.1364/OE.523274 -
BMC Plant Biology Jun 2024Tomato (Lycopersicon esculentum), a valuable economic crop worldwide, often goes to waste due to improper packaging and handling. In the present study, three types of...
BACKGROUND
Tomato (Lycopersicon esculentum), a valuable economic crop worldwide, often goes to waste due to improper packaging and handling. In the present study, three types of low-density polyethylene nanocomposite films containing 3% clay (Closite 20A), 3% TiO nanoparticles, and their combination were synthesized using melt blending method, and evaluated on the quality parameters of tomato fruit during 42 days of storage at 4 °C.
RESULTS
Transmission electron microscopy confirmed the degree of dispersion and exfoliation of the nanoparticles. The TiO/clay-nanocomposite films exhibited notable enhancements in Young's modulus and tensile strength compared to conventional films. The addition of clay and TiO nanoparticles resulted in reduced permeability to CO, O, and water vapor. Fruits packed with clay/TiO nanocomposite films showed decreased ethylene production, mitigated weight loss, and maintained pH, titratable acidity, total soluble solids, and firmness. Furthermore, clay/TiO nanocomposite films enhanced membrane stability, decreased membrane lipid peroxidation, and enhanced catalase and ascorbate peroxidase enzyme activity in fruits.
CONCLUSIONS
The relatively good exfoliation of clay nanoparticles and the proper dispersion of TiO nanoparticles, which were confirmed by TEM, led to an increase in mechanical and physical properties in the Clay/TiO nanocomposite. This film displayed more potential in maintaining the quality properties of tomato fruit during cold storage. Therefore, this film can be considered a practical solution for minimizing pathogen risks and contamination, and enhancing the overall quality of tomato fruit.
Topics: Solanum lycopersicum; Titanium; Clay; Fruit; Food Packaging; Food Preservation; Food Storage; Cold Temperature; Nanocomposites; Aluminum Silicates
PubMed: 38853259
DOI: 10.1186/s12870-024-05215-0 -
Ecotoxicology and Environmental Safety Jul 2024The widespread utilization of plastic products ineluctably leads to the ubiquity of nanoplastics (NPs), causing potential risks for aquatic environments. Interactions of...
Heteroaggregation and deposition behaviors of carboxylated nanoplastics with different types of clay minerals in aquatic environments: Important role of calcium(II) ion-assisted bridging.
The widespread utilization of plastic products ineluctably leads to the ubiquity of nanoplastics (NPs), causing potential risks for aquatic environments. Interactions of NPs with mineral surfaces may affect NPs transport, fate and ecotoxicity. This study aims to investigate systematically the deposition and aggregation behaviors of carboxylated polystyrene nanoplastics (COOH-PSNPs) by four types of clay minerals (illite, kaolinite, Na-montmorillonite, and Ca-montmorillonite) under various solution chemistry conditions (pH, temperature, ionic strength and type). Results demonstrate that the deposition process was dominated by electrostatic interactions. Divalent cations (i.e., Ca, Mg, Cd, or Pb) were more efficient for screening surface negative charges and compressing the electrical double layer (EDL). Hence, there were significant increases in deposition rates of COOH-PSNPs with clay minerals in suspension containing divalent cations, whereas only slight increases in deposition rates of COOH-PSNPs were observed in monovalent cations (Na, K). Negligible deposition occurred in the presence of anions (F, Cl, NO, CO, SO, or PO). Divalent Ca could incrementally facilitate the deposition of COOH-PSNPs through Ca-assisted bridging with increasing CaCl concentrations (0-100 mM). The weakened deposition of COOH-PSNPs with increasing pH (2.0-10.0) was primarily attributed to the reduce in positive charge density at the edges of clay minerals. In suspensions containing 2 mM CaCl, increased Na ionic strength (0-100 mM) and temperature (15-55 C) also favored the deposition of COOH-PSNPs. The ability of COOH-PSNPs deposited by four types of clay minerals followed the sequence of kaolinite > Na-montmorillonite > Ca-montmorillonite > illite, which was related to their structural and surface charge properties. This study revealed the deposition behaviors and mechanisms between NPs and clay minerals under environmentally representative conditions, which provided novel insights into the transport and fate of NPs in natural aquatic environments.
Topics: Clay; Calcium; Water Pollutants, Chemical; Osmolar Concentration; Hydrogen-Ion Concentration; Aluminum Silicates; Polystyrenes; Temperature; Minerals; Bentonite; Nanoparticles; Kaolin; Static Electricity
PubMed: 38850697
DOI: 10.1016/j.ecoenv.2024.116533 -
Environmental Geochemistry and Health Jun 2024The present study firstly reports surface sediment from the subsea depth of 200 m as a potential natural peloid. The fine-silt sediment exhibited a consistent clay...
The present study firstly reports surface sediment from the subsea depth of 200 m as a potential natural peloid. The fine-silt sediment exhibited a consistent clay mineral composition dominated by illite, chlorite, kaolinite, and diatomite. The most abundant clay mineral was illite/mica, with other minerals loosely packed in a face-to-face orientation. The thermal conductivity, specific heat capacity, and cation-exchange capacity of the sediment were in the range 0.855-0.885 W/m K, 2.718-2.821 J/g °C, and 23.06-32.96 cmol/kg, respectively. The concentrations of most toxic elements in the sediment were considerably lower than the limits set by domestic cosmetic regulations and other international standards. The analyzed samples exhibited similar properties to those of previously reported peloids, thus making them suitable for use in the field of pelotherapy; furthermore, the consistency in data across a wide peloid-distribution area is expected to enable economically viable mining. Future investigations should aim to to evaluate the long-term effects on the skin, the bioavailability of potentially hazardous substances, and the therapeutic efficacy for various skin conditions.
Topics: Geologic Sediments; Republic of Korea; Mud Therapy; Clay; Aluminum Silicates; Minerals; Environmental Monitoring
PubMed: 38849660
DOI: 10.1007/s10653-024-02014-2 -
Environmental Geochemistry and Health Jun 2024Dyes, considered as toxic and persistent pollutants, must be removed from organic wastes prior to their composting and application in sustainable agriculture. Azo dyes,...
Dyes, considered as toxic and persistent pollutants, must be removed from organic wastes prior to their composting and application in sustainable agriculture. Azo dyes, capable of altering the physicochemical properties of soil, are difficult to expel by conventional wastewater treatments. C.I. Acid Black 1 (AB 1), a sulfonated azo dye, inhibits nitrification and ammonification in the soil, lessens the nitrogen use efficacy in crop production and passes substantially unaltered through an activated sludge process. The retention of C.I. Acid Black 1 by raw and expanded perlite was investigated in order to examine the potential effectiveness of this aluminosilicate material toward organic waste cleanup. Dye adsorption proved spontaneous and endothermic in nature, increasing with temperature for both perlites. Expanded perlite having a more open structure exhibited a better performance compared to the raw material. Several of the most widely recognized two-parameter theoretical models, i.e., Langmuir, Freundlich, Temkin, Brunauer-Emmett-Teller (BET), Harkins-Jura, Halsey, Henderson, and Smith, were applied to reveal physicochemical features characterizing the adsorption. The Langmuir, Freundlich, Temkin, BET, Henderson, and Smith equations best fitted experimental data indicating that the adsorption of anionic dye on perlites is controlled by their surface, i.e., non-uniformity in structure and charge. This heterogeneity of surface is considered responsible for promoting specific dye adsorption areas creating dye "islands" with local dye supersaturations.
Topics: Aluminum Oxide; Adsorption; Silicon Dioxide; Coloring Agents; Naphthalenesulfonates; Waste Management; Azo Compounds; Anthraquinones
PubMed: 38849572
DOI: 10.1007/s10653-024-02013-3 -
STAR Protocols Jun 2024A membrane reactor (MR) offers a solution to overcome thermodynamic equilibrium limitations by enabling in situ product separation, enhancing product yields and energy...
A membrane reactor (MR) offers a solution to overcome thermodynamic equilibrium limitations by enabling in situ product separation, enhancing product yields and energy efficiency. Here we present a protocol for synthesizing a carbon MR that couples a H-permeable carbon molecular sieve hollow fiber membrane and a metal supported on zeolite catalyst for non-oxidative propane and ethane dehydrogenation. We describe steps for catalyst preparation, membrane fabrication, and MR construction. The as-developed MR has significant improvements in alkene yield and a record-high stability. For complete details on the use and execution of this protocol, please refer to Liu et al..
Topics: Carbon; Alkanes; Catalysis; Zeolites; Membranes, Artificial; Hydrogenation; Hydrogen; Oxidation-Reduction
PubMed: 38843401
DOI: 10.1016/j.xpro.2024.103112 -
Clinical, Cosmetic and Investigational... 2024This study aimed to evaluate the bond strength of a universal adhesive to dentin (μTBS) using different time periods of airborne particle abrasion (APA) and two types...
OBJECTIVE
This study aimed to evaluate the bond strength of a universal adhesive to dentin (μTBS) using different time periods of airborne particle abrasion (APA) and two types of acid etching.
METHODS
Seventy-two human third molars were divided into 9 groups (n=8) according to dentin pretreatment: APA duration (0, 5, or 10s) and acid etching (no acid - NA, 37% phosphoric acid - PhoA, or 1% phytic acid - PhyA). APA was performed at a 0.5 cm distance and air pressure of 60 psi using 50 μm aluminum oxide particles. Afterwards, two coats of Single Bond Universal adhesive (3M) were applied to the dentin surface. Composite blocks were built using the incremental technique, sectioned into 1×1 mm slices and subjected to microtensile bond strength (μTBS) testing. Fracture patterns and surface topography of each dentinal pretreatment were evaluated using a Scanning electron microscope (SEM). Bond strength data were analyzed using two-way ANOVA and Bonferroni tests.
RESULTS
The group that received pretreatment with 5s APA and PhoA presented higher μTBS values among all groups, which was statistically different when compared with the PhoA, 10APA+PhoA, and 5APA+PhyA groups. PhyA did not significantly influence the bond strength of the air-abraded groups. Finally, adhesive failure was considered the predominant failure in all groups.
CONCLUSION
Dentin pretreated by airborne particle abrasion using aluminum oxide demonstrated an increase in bond strength when abraded for 5 seconds and conditioned with phosphoric acid in a universal adhesive system.
PubMed: 38835853
DOI: 10.2147/CCIDE.S456826 -
Scientific Reports Jun 2024Organic-inorganic hybrid light-emitting devices have garnered significant attention in the last few years due to their potential. These devices integrate the superior...
Organic-inorganic hybrid light-emitting devices have garnered significant attention in the last few years due to their potential. These devices integrate the superior electron mobility of inorganic semiconductors with the remarkable optoelectronic characteristics of organic semiconductors. The inquiry focused on analyzing the optical and electrical properties of a light-emitting heterojunction that combines p-type GaN with organic materials (PEDOT, PSS, and PMMA). This heterojunction is an organic-inorganic hybrid. The procedure entailed utilizing a spin-coating technique to apply a layer of either poly(methyl methacrylate) (PMMA) or a mixture of PMMA and poly(3,4ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT: PSS) onto an indium tin oxide (ITO) substrate. Subsequently, different Nd:YAG laser pulses (200, 250, and 300 pulses) were used to administer a GaN inorganic layer onto the prepared organic layer using a pulsed laser deposition approach. Subsequently, the thermal evaporation technique was employed to deposit an aluminum electrode on the top of the organic and inorganic layers, while laser pulses were fine-tuned for optimal performance. The Hall effect investigation verifies the p-type conductivity of the GaN material. The electroluminescence studies confirmed the production of blue light by the GaN-based devices throughout a range of voltage situations, spanning from 45 to 72 V.
PubMed: 38834703
DOI: 10.1038/s41598-024-63197-3 -
Journal of International Society of... 2024The success of layered restorations necessitates the utilization of an improved restorative material compatible with composite restorations. Therefore, in this line of...
AIM
The success of layered restorations necessitates the utilization of an improved restorative material compatible with composite restorations. Therefore, in this line of research, the strength of adhesion of conventional resin-based dental composite to different filling materials was tested.
MATERIALS AND METHODS
Conventional composite resin was bonded to four restorative materials (Group I: conventional glass ionomer cement (GIC), Group II: resin-modified glass ionomer cement, Group III: flowable composite, and Group IV: Cention-N) received no surface treatment (Subgroup A: control), sandblasting using 50-µm aluminum oxide particles (Subgroup B), sandblasting and resin adhesive (Subgroup C), acid etch and resin adhesive (Subgroup D), or self-etch resin adhesive (Subgroup E). After 24 h, the strength of adhesion between the conventional composite resin and the other tested filling materials was estimated by using a universal testing machine and compared using one-factor analysis of variance and Tukey's method.
RESULTS
The conventional GIC had the minimum values of adhesion strength while the flowable composite and Cention-N had the maximum values of adhesion strength ( < 0.05). The treatment of the used restorative materials with sandblasting and resin adhesive boosted the adhesion strength ( < 0.05). The surface treatment of GIC-based materials with either acid etch and resin bonding agent or self-etch resin bonding agent boosted the adhesion strength ( < 0.05).
CONCLUSION
Cention-N sandblasted and coated with resin adhesive before the application of conventional composite resin in layered restorations is a potential alternative to GIC-based restorations and flowable composite.
PubMed: 38827354
DOI: 10.4103/jispcd.jispcd_4_24 -
Yakugaku Zasshi : Journal of the... 2024Microbial exudates including siderophore, which changes chemical species of actinides and lanthanides. We have investigated effects of desferrioxamine B (DFOB; one of... (Review)
Review
Microbial exudates including siderophore, which changes chemical species of actinides and lanthanides. We have investigated effects of desferrioxamine B (DFOB; one of the siderophores) and siderophore-like organic molecules (SLOM) on the adsorption of lanthanides by microbial cells, aluminium oxide (AlO), and manganese (Mn) oxides. When DFOB was present, the distribution coefficients of cerium (Ce) were measured to be lower than those of neighboring elements of lanthanum (La) and praseodymium (Pr) (Negative anomaly of Ce adsorption). Even though initial oxidation state of Ce in the solution was III, that was changed to IV after the addition of DFOB, indicating that Ce(III) was oxidized by forming complex with DFOB. When lanthanides were adsorbed by biogenic Mn(IV) oxides, negative anomaly of Ce adsorption was observed in the sorption in alkaline solution. Ce(III) was oxidized to forme the complexes of Ce(IV) with SLOM in the solution. These results show that siderophore possesses high performance of oxidation of Ce(III) to Ce(IV) during association, affectiong the adsorption behavior of Ce. After Fukushima accident, radioactive Cs accumulation by Eleutherococcus sciadophylloides (Koshiabura) caused by the dissolution of Fe from soil around the roots, that was dominated by siderophore releasing microorganisms (SB). These SBs may enhance dissolution of iron (Fe) and uranium (U) phases in the nuclear fuel debris formed in the nuclear reactors in Fukushima Daiichi nuclear power plant. Thus, in the interaction between microorganisms and radionuclides, SLOMs discharged by microorganisms are deeply involved in the chemical state change of radionuclides.
Topics: Siderophores; Adsorption; Oxidation-Reduction; Deferoxamine; Aluminum Oxide; Lanthanoid Series Elements; Manganese Compounds; Oxides; Cerium; Radioisotopes
PubMed: 38825474
DOI: 10.1248/yakushi.23-00197-4