Morphological Properties Research Articles

Suppressed surface aggregation and homogeneous integration of π-Bridged polyelectrolyte for boosting charge transport in conjugated polymer semiconductors

The introduction of extrinsic materials into host materials has been extensively considered for resolving the challenge of intrinsically low charge movement within semiconducting polymers. One of the difficult issues is developing a dopant that can provide a sufficient interfacial area between host and dopant as well as maintain an efficient charge transport pathway without significantly altering the morphological and crystalline properties of semiconducting polymers. Herein, we propose the use of conjugated polyelectrolyte (CPE), a new highly mixable and mutual dopant for achieving enhanced charge mobility in host conjugated polymers. We found that CPE has more homogeneous dispersion in host polymers than non-conjugated polymeric dopants. This results in enhanced charge mobility in the organic field-effect transistor (OFET) based on a novel p-type semiconducting polymer, poly(3-hexylthiophene) (P3HT) (from 0.076 to 0.135 cm2 V−1 s−1). Atomic force microscopy and grazing incident X-ray diffraction measurements were used to confirm the non-destructive behavior of CPE within P3HT. Therefore, it is believed that CPE is promising for use as a homogeneous chemical dopant for polymer semiconductors.

Impact of aragonite coral powder on hydration, strength, and rheology of cement paste

Understanding the intricate bonding mechanism between coral reef surfaces and C–S–H is crucial for advancing large-scale engineering applications. This study conducts a comprehensive analysis of the impact of coral powder (CP) on cement paste. Initially, zeta potential experiments were performed to probe ion adsorption from the cement pore solution at the CP interface. We propose a novel model to quantify the adsorption of Ca2+ by CP. Subsequently, the study delves into the morphological properties of C–S–H nucleation and growth at this interface and formulates an equation elucidating the CP and Ca2+ adsorption relationship. Then, the crack extension behavior of cementitious materials was scrutinized. Finally, an examination of CP effects on the rheological properties of fresh cement pastes is presented. The findings indicate that CP particles exhibit a notably weaker adsorption affinity with Ca2+ compared to their interaction with SO42−. Compared to limestone (LP), CP exhibited a 32.1 % reduction in Ca2+ adsorption in Ca(OH)2 solutions, 44.2 % reduction in Ca(OH)2 + 10 mmol/L K2SO4, and 40.6 % reduction in Ca(OH)2 + 50 mmol/L K2SO4 solutions. Higher zeta potential values correspond to stronger Ca2+ adsorption and broader surface coverage of Ca2+. The inferior surface characteristics of CP hinder C–S–H nucleation and growth, leading to a low CH orientation index in cement paste containing CP. These pastes exhibit cracks more frequently between CP and hydration products. An attractive force is observed between CP and cement particles, decreasing cement paste flowability.

Polypeptide urea increases rice yield and nitrogen use efficiency through root growth improvement

ContextElucidating rice root growth and development characteristics is essential for improving nitrogen use efficiency (NUE) and grain yield (GY) of crops, particularly in light of innovations such as polyaspartic acid (PASP)–urea formulations. However, the effectiveness of PASP–urea on the morphological properties of rice roots is insufficiently explored. ObjectiveWe aimed to examine the effect of PASP–urea on root morphology properties, NUE, and grain yield of mid-season rice in southwest China. MethodsIn 2016 and 2017, a two-factor randomized block design experiment was conducted in Sichuan, China, during the rice planting season. Three N treatments: no N (control), conventional urea [CU], and polyaspartic acid–urea [PU] were administered to two rice varieties: Yixiangyou 2115 and Fyou 498. ResultsOur findings showed that grain yield and nitrogen recovery efficiency (NRE) of rice were closely related to the root surface area density (RSAD), root length density (RLD), and root volume density (RVD) of rice. Compared to the CU treatment, the PU application significantly boosted the root dry matter weight, RLD, RVD, and RSAD of both varieties by 12.00–16.87 %, 0.16–28.98 %, 12.41–37.06 %, and 8.14–33.66 % at the jointing, heading, and maturity stages, respectively. This contributed to a 0.37–15.63 % and 23.45–48.12 % increase in grain yield and NRE, respectively, in both years, and a 12.26–15.69 % increase in N partial productivity efficiency (NPPE) in 2017 by improving the effective panicle number per unit area, spikelets per panicle, and N uptake. ConclusionNRE and grain yield of rice were significantly increased by PU application by improving the rice root system. ImplicationsThe study findings offer insight on how PASP–urea application influences the root morphology of rice and its relationship with grain yield and NRE while offering novel strategies and concepts for optimizing N use in rice cultivation.

Novel nanoporous amorphous/nanocrystalline composite structured RuNiFeCo multicomponent alloys with exceptional catalytic activity for ammonia borane hydrolytic dehydrogenation

The pursuit of high-efficient and cost-effective catalysts for hydrogen generation is imperative to address the energy crisis. Herein, nanoporous RuNiFeCo alloys (np-RuNiFeCo) with high catalytic activity for ammonia borane (AB) hydrolytic dehydrogenation have been prepared by dealloying Fe25NixCo40-xRu5B30 (x = 0–40) high-entropy amorphous alloys with low Ru content. The np-RuNiFeCo are composed of an amorphous/hexagonal close-packed Ru nanocrystalline dual-phase structure and exhibit a uniform nanopore/ligament bicontinuous architecture. The morphology, composition, and AB hydrolysis catalytic properties of the np-RuNiFeCo can be regulated by varying the Ni/Co content in the precursors, and the best catalytic activity with a high turnover frequency value of 148.2 molH2molRu‐1min‐1 and a low apparent activation energy of 25.3 kJmol‐1 was obtained when x = 30. Density functional theory simulations indicate that the presence of Ni, synergizing with Fe and Co, promotes electron transfer to Ru and enhances the adsorption energies of both AB and H2O molecules while reducing the activation barrier for cleaving the H2O molecule, leading to enhanced intrinsic catalytic activity of the alloy. The exceptional catalytic performance of the np-RuNiFeCo arises from the synergy of multiple principal elements, nanoporous morphology, and amorphous/nanocrystalline heterogeneous interface. In addition, the mechanisms of dealloying and nanoporous structure formation have been discussed based on surface diffusion.

Single-exposure femtosecond laser direct writing of Salvinia-inspired micropatterned functional surface

Bioinspired functional surfaces have attracted considerable attention within multiple scientific and industrial fields. In particular, the hollow hierarchical structure and chemical heterogeneity endow Salvinia leaves with superhydrophobicity and underwater air retention capability. However, replicating complex three-dimensional Salvinia-like patterns at the microscale currently relies on time-consuming additive manufacturing methods, preventing their wide adoption in industrial applications. Here, we report a high-throughput femtosecond laser direct writing strategy based on the quadrifurcate abruptly autofocusing beam for the single-exposure fabrication of Salvinia-like microstructures. Combined with chemical functionalization, both the hollow morphology and heterogeneous chemical properties of the natural counterpart were mimicked. The obtained bioinspired surfaces can repel and manipulate water droplets, and maintain superhydrophobicity even immersed underwater. The proposed single-exposure fabrication strategy is expected to contribute to the mass production of Salvinia-inspired surfaces, whose unique wetting properties promise great potential in chemical engineering, micro bioanalysis, and microfluidic devices.

Photo-rechargeable asymmetric supercapacitors based on nickel–cobalt sulfide on titania as novel photo-active electrodes

Photo-supercapacitors (PSCs), which are environmentally benign devices for direct conversion and storage of solar energy into electricity, have a high potential for eliminating the requirement for grid electricity for a sustainable future. In this research, nickel sulfide (NS), cobalt sulfide (CS) and nickel cobalt sulfide (NCS) deposited on TiO2 nanotubes (TNT) have been prepared as novel photoactive electrodes for photorechargeable supercapacitors. X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM), High-resolution transmission electron microscopy (HRTEM), Energy-dispersive X-ray analysis (EDX), Brunauer-Emmett-Teller (BET), Thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and Ultraviolet–visible spectroscopy (UV–Vis) were used to characterize the phase, morphology, elemental composition, oxidation states and optical properties of the films produced. Based on the photoelectrochemical measurements, the NCS@TNT-1 samples showed higher capability to produce and separate photogenerated charges compared to bare TNTs, NS@TNT and CS@TNT. The highest capacity of up to 471.6 mF/cm2 (at 0.7 mA/cm2) was shown by the NCS@TNT-1 electrode, which is about 11 times higher than that of bare TNTs (44 mF/cm2). In addition, the specific capacitance of the NCS@TNT-1 electrode (as the best sample) increased approximately twofold, reaching 955.6 mF/cm2 upon light illumination. Three photochargeable asymmetric supercapacitors were fabricated with NCS@TNT as the electrode and PVA-KOH as the electrolyte and separator. The specific capacitance of the fabricated supercapacitor increased by 1.57 times when illuminated by light. The device showed outstanding stability over 10,000 galvanostatic charge and discharge cycles with a capacity retention of 87 % and 94 % in the dark and under light conditions, respectively. More importantly, the illumination resulted in an extended discharge time.

Study on heat-treated pyrolytic carbon deposited from methane on directly heated carbon fibres

The study investigated the morphology, microstructure, structure, texture, and mechanical properties of heat-treated at 1600 °C and 2000 °C pyrolytic carbon (PyC) deposited from methane using various methods such as scanning electron microscopy (SEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), Raman spectroscopy, and ultrasonic dynamic measurements of Young's modulus. The PyC was synthesised at 1100 °C using a chemical vapour deposition (CVD) method with direct electrical heating of the two types of carbon fibres (CFs). The results showed that the PyC had a low- and medium-texture (LT and MT PyC). Analysis of the graphitization trajectory allowed the determination of structural changes in the material as a function of temperature, including the growth of crystallites and an increase in the crystallinity proportion without the significant rearrangement within PyC. The crystallite size and the number of interstitial defects has increased with temperature that controlled mechanical properties. Therefore, based on the results obtained, the most suitable composites for further research in the context of electrodes for stimulation of nervous tissue were obtained at the temperature of their synthesis, i.e. at 1100 °C.

Rigid polyurethane foams from commercial castor oil resins

Rigid polyurethane foams (RPUFs) are among the most used polymeric materials due to their tailorable properties. Greener and biobased polyol sources for synthesising RPUFs have been recently prototyped because of the ever-growing demand for more sustainable materials solutions. Castor Oil has also rapidly become one of the most successful alternatives to replace polyurethane fossil-based components. This study extensively investigates three types of RPUFs developed from commercially available Castor Oil-based resins, correlating their properties across different length scales. In particular, X-ray diffraction identified a characteristic peak whose intensity correlated with the apparent foam density, morphology (obtained from computed tomography scans) and mechanical properties. Furthermore, quasi-static compression and vibration transmissibility tests revealed distinctive anisotropic mechanical responses among the foams, with one type of RPUF consistently outperforming the others due to its lower porosity, reaching 13.3 MPa of compressive modulus. These findings demonstrate the possibility of tuning the mechanical properties of foams via compositional control.

Investigating the preparation process of excellent Cu3VSe4 absorption layer prepared by amine-thiol system

Cu3VSe4 material has become a new kind of photovoltaic absorber due to its optical bandgap matching light-absorbing, abundant elements in crust, and high light absorption coefficient. Here, we prepared Cu3VSe4 thin films by amine-thiol method and investigated the preparation process of excellent Cu3VSe4 absorption layer for the first time. The effects of various Cu/V ratios on the morphology, structure, and electrical properties of the films are studied. XRD and Raman results show that pure-phase Cu3VSe4 films are obtained with the Cu/V ratios lower than 2.9. SEM results simply adjusting the Cu/V ratio cannot obtain a compact selenized Cu3VSe4 thin films. The best crystallinity of thin film with 2.8 of Cu/V ratio is named as Cu2.8VSe4 and selected as the representative. Though optimizing the selenization conditions, a dense morphology and good electrical properties of the absorption layer can be prepared under 570 °C of the high-temperature process. Our findings can lay the favorable foundation for high-efficiency Cu3VSe4 devices.

Application of Cotton Stalk as an Adsorbent for Copper(II) Ions in Sustainable Wastewater Treatment

The capacity of untreated cotton stalk to remove and adsorb Cu2+ ions in synthetic and natural aqueous solutions was evaluated. The influence of three sensitive parameters of the adsorption process—solution pH, adsorbent dosage, and contact time—on the percentage of Cu2+ removal in agricultural wastewater, livestock wastewater, and synthetic samples was studied. Physicochemical and morphological properties were studied using thermogravimetry, Fourier infrared spectrophotometry, and scanning electron microscopy. The elemental composition, proximal composition, zero charge point, and acid–base sites were determined. In addition, kinetic studies were performed, and the adsorption equilibrium was analyzed. The optimum conditions for Cu2+ adsorption were the following: solution pH = 5.5, adsorbent dosage of 0.6 g, and contact time of 60 min. Under these conditions, the percentage of Cu2+ removal in synthetic samples was 66.5% when the initial copper concentration was 50 mg/L. The removal percentage in agricultural and livestock wastewater samples was 87.60% and 85.05%, respectively, when the initial copper concentration was 25 mg/L. The adsorption data are consistent with the Freundlich isotherm model, which achieved a quadratic fit of 0.991 compared to 0.5542 for the Langmuir model. The experimental results indicate that the adsorption adequately fits the pseudo-second-order kinetic model. The results suggest that cotton stalks are a promising adsorbent for the ecological and economical removal of Cu2+ in wastewater. This research, therefore, provides relevant information that contributes to the sustainable management of agricultural waste and instills hope for a reduction in water pollution from heavy metals derived from agricultural activities.

Valorisation of coal gasification slag and fly ash to mesoporous activated carbon @zeolite socony mobil-5 composite for preconcentration of pharmaceuticals and their removal

Upcycling industrial solid waste, such as coal gasification slag and fly ash, to functional adsorbents with unique structures for water decontamination is of great importance to achieving Sustainable Development Goal 6.0. This study used coal gasification slag and fly ash to synthesise mesoporous activated carbon @zeolite socony mobil-5 (MAC@ZSM-5) composite. Various analytical techniques were used to investigate the surface, morphological, and structural properties of the MAC@ZSM-5 composite. The MAC@ZSM-5 composite had a relatively high specific surface and was classified as a mesoporous adsorbent. The MAC@ZSM-5 composite was used as an adsorbent in ultrasound-assisted micro solid phase extraction (UA-µSPE) for effective preconcentration and removal of aspirin (ASP), ibuprofen (IBP), and paracetamol (PCT) from water samples before determination by high-performance liquid chromatography equipped with a photodiode array detector (HPLC-DAD). The Langmuir adsorption isotherm characterised the adsorptive removal method, while the kinetics followed a pseudo-second order type. Thermodynamic studies revealed that the adsorption process was endothermic, spontaneous, and chemisorption. Additionally, the UA-µSPE/HPLC-DAD method displayed a good linear range of 0.1–1000 µg/L, with a coefficient of determination greater than 0.99. The developed method had a good performance, as shown by the relatively low limits detection (LODs: 0.017–0.064 µg/L) and quantification (LOQs: 0.057–0.21 µg/L) as well as high precision (relative standard deviation (%RSD) < 5 %). The proposed method was applied successfully for preconcentration and removal of the target analytes from real water samples. The MAC@ZSM-5 composite was reusable (up to 5 cycles) and proved a promising adsorbent for effective extraction, preconcentration, and adsorptive removal of emerging contaminants from water bodies.

Recent Advances in the Photonic Curing of the Hole Transport Layer, the Electron Transport Layer, and the Perovskite Layers to Improve the Performance of Perovskite Solar Cells.

Perovskite solar cells (PSCs) have attracted increasing research interest, but their performance depends on both the choice of materials and the process used. The materials can typically be treated in solution, which makes them well suited for roll-to-roll processing methods, but their deposition under ambient conditions requires overcoming some challenges to improve stability and efficiency. In this review, we highlight the latest advancements in photonic curing (PC) for perovskite materials, as well as for hole transport layer (HTL) and electron transport layer (ETL) materials. We present how PC parameters can be used to control the optical, electrical, morphological, and structural properties of perovskite HTL and ETL layers. Emphasizing the significance of these advancements for perovskite solar cells could further highlight the importance of this research and underline its essential role in creating more efficient and sustainable solar technology.

Multiscale damage evolution and fracture for thermal aging energetic material based on mesoscopic observation and molecular dynamics simulation

As a composite energetic material composed of filler and matrix, the mechanical properties of HTPB propellants change constantly due to the aging of each component and component interfaces during long-term storage. However, the study of a single component or performance parameter limits disclosure of the complex aging mechanism and mechanical property evolution. Therefore, based on accelerated thermal aging experiments, this study integrated gas detection, contact angle testing, in situ loading experiments, digital image correlation numerical analysis, and all-atom molecular dynamic simulations to explore the underlying mechanism of structural morphology and mechanical property changes during propellant aging. The results showed that the aging reaction was dominated by degradation chain breaking in the early stage and oxidative crosslinking in the later stage. Degradation chain breaking enhanced interfacial bonding between the two phases, while oxidative crosslinking deteriorated interfacial bonding. Compared with lossless specimens, short-term thermal aging weakened the strength of the matrix and enhanced bonding interfaces. During in situ loading, interfacial pore expansion and matrix damage and fracture occurred simultaneously and the matrix became the key damage source. However, with the extension of thermal aging time, the strength of the matrix increased, bonding interface weakened, and bonding interfaces became a weak point of loading. This made the high-strain area change from the matrix at the initial loading stage to the bonding interface and the damage of the bonding interface caused whole fracture of the specimen. The external loading resulted in the rearrangement of interfacial molecular chains, change of molecular spacing, and initiation and expansion of micropores between molecular chains. The tractor-separation curve conformed to the exponential cohesion model and the damage mode of the interface layer changed between adhesion and cohesion due to thermal aging.

Effect of laser power on morphology, microstructure and mechanical properties of CBN abrasive block prepared by two-step laser cladding

The preparation of cubic boron nitride (CBN) grinding tools using laser cladding has the advantages of strong bonding, short time consumption and customizable abrasive arrangement. In this paper, a two-step laser cladding method was used to prepare CBN abrasive blocks with the aim of reducing laser damage to CBN grits during the laser cladding process. The cross-sectional morphology of CBN abrasive blocks under different laser power conditions was characterized, and the relationship among laser power, preparation method, and forming quality of Cu–Sn–Ti/CBN cladding layer was investigated. Then, the microstructure at the Cu–Sn–Ti/CBN interface under different laser power conditions was characterized, and the main phase compositions at the Cu–Sn–Ti/CBN interface were analyzed. Finally, the grinding tests were carried out on CBN abrasive blocks. The results show that as the laser power increases from 250 W to 400 W, the fracture ratio of CBN grits increases dramatically from 4.3 % to 17.3 %. TiN, TiB2, and TiB compounds are all detected at the Cu–Sn–Ti/CBN interface under different laser power conditions. The mass loss of the TC4 wheel caused by the CBN abrasive block initially increases and then decreases as the laser power increases from 250 W to 400 W. The CBN abrasive block has the optimum material removal performance at the laser power of 300 W using two-step laser cladding. The results provide a theoretical basis for the preparation of high-performance CBN grinding tools using laser cladding.

Sulfonated graphene oxide linked with alkali metal ions membranes for proton conductivity in hydrogen production from water electrolysis

Amid technological advances, rising energy demand, and environmental concerns, countries endorse green energy solutions. Prominent among them is hydrogen production via clean water electrolysis, a key strategy for sustainable development. Herein, to address the limitations of expensive and potentially harmful Nafion membranes, we have developed a new graphene oxide (GO) series membranes (hydrophilic sulfonated GO (GO-SO3H) linked with monovalent alkali metal ions were synthesized to fabricate the membranes) to be used in water electrolysis for hydrogen production by introducing the iodide oxidation reaction (IOR) as an alternative to the traditional oxygen evolution reaction (OER). Various modifications by sulfuric acid, methanol, and different alkali metal hydroxides (LiOH, NaOH, KOH) result in membranes with distinct properties. Characterization techniques, including ATR-FTIR, SEM, AFM, XRD, water contact angle (WCA), and electrochemical impedance spectroscopy (EIS), validated the modifications, assessed membrane morphology, interlayer spacing, hydrophilicity, and electrical properties. Among the membranes, GO-SO3K stood out, exhibiting the highest proton conductivity (119.16 mS) and superior potassium ion permeability (20.382 cm/s). Importantly, all GO series membranes demonstrate excellent stability in the electrochemical system. The findings suggested that GO-SO3K holds promise as a potassium ion-conductive membrane for efficient and sustainable hydrogen production, offering a viable alternative to conventional Nafion membranes in water electrolysis applications.

Utilizing Artificial Neural Networks for Geometric Bone Model Reconstruction in Mandibular Prognathism Patients

Patient-specific 3D models of the human mandible are finding increasing utility in medical fields such as oral and maxillofacial surgery, orthodontics, dentistry, and forensic sciences. The efficient creation of personalized 3D bone models poses a key challenge in these applications. Existing solutions often rely on 3D statistical models of human bone, offering advantages in rapid bone geometry adaptation and flexibility by capturing a range of anatomical variations, but also a disadvantage in terms of reduced precision in representing specific shapes. Considering this, the proposed parametric model allows for precise manipulation using morphometric parameters acquired from medical images. This paper highlights the significance of employing the parametric model in the creation of a personalized bone model, exemplified through a case study targeting mandibular prognathism reconstruction. A personalized model is described as 3D point cloud determined through the utilization of series of parametric functions, determined by the application of geometrical morphometrics, morphology properties, and artificial neural networks in the input dataset of human mandible samples. With 95.05% of the personalized model’s surface area displaying deviations within −1.00–1.00 mm relative to the input polygonal model, and a maximum deviation of 2.52 mm, this research accentuates the benefits of the parametric approach, particularly in the preoperative planning of mandibular deformity surgeries.

Mechanical properties of tribofilms formed by metal dithiodiphosphates

Lubrication-based tribofilms are crucial in protecting contacting parts from wear and friction. A popular and well-studied additive commonly used in tribofilm formation is zinc dialkyldithiophosphate (ZDDP). While ZDDP has been shown to be an effective additive, the use of other metals in place of zinc may provide further benefits. Tribofilms were generated using fluids which contained DDPs neutralized with octylamine or different metals: magnesium, titanium, and zinc. Tribofilms were formed at 30 min, 60 min, and 120 min and were chemically and mechanically analyzed using EDS, AFM, and nanoindentation. Tribofilms were also analyzed based on property differences at the peak surface interactions. The metal used was found to have a significant effect on both tribofilms morphology and mechanical properties. Properties were further seen to change in the top 10% of the tribofilm surface as compared to bulk surface properties. Hardness and elastic modulus ratios were higher for the tribofilms formed by octylamine and MDDP as compared to TDDP and ZDDP tribofilms, but with the tradeoff of less tribofilm coverage of the substrate.

Fabrication and Properties of Bi2S3 Nanowire Thin Film Solar Cells by Spin Coating with Varying Sulfur Concentrations in the Precursor

We conducted a simple solution-based method to fabricate Bi2S3 nanowire thin film solar cells by spin coating with varying sulfur-to-bismuth ratios. Spherical nanoparticles were observed in the thin film with low-concentration sulfur solution, with these nanoparticles gradually changing to nanorods. Finally, nanowires of Bi2S3 were observed in the thin film with a high sulfur concentration in solution. The band gap gradually decreased with the increase in sulfur concentration. The solar cell performance was significantly improved with the nanowire structure. During film fabrication, sulfur vacancy defects appeared primarily because of high annealing temperatures. These defects were somewhat reduced by the high concentration of sulfur in the solution, supported by the energy-dispersive x-ray spectroscopy (EDS) results. The elemental chemical composition of Bi2S3 material showed an increase in the sulfur-to-bismuth ratio, reaching saturation at almost 0.9. In this work, we systematically observed the effect on the optical properties, surface morphology, and photovoltaic properties by changing the concentration of sulfur in the precursor. The nanowire structure with a high concentration of sulfur in the solution is a promising way to improve the Bi2S3 thin film solar cell.

JWST/CEERS sheds light on dusty star-forming galaxies: Forming bulges, lopsidedness, and outside-in quenching at cosmic noon

We investigate the morphology and resolved physical properties of a sample of 22 IR-selected dusty star-forming galaxies at cosmic noon using the James Webb Space Telescope NIRCam images obtained in the EGS field for the CEERS survey. The exceptional resolution of the NIRCam images allowed us to spatially resolve these galaxies up to $4.4 and identify their bulge or core even when very extinguished by dust. The goal of this study is to obtain a better understanding of the formation and evolution of FIR-bright galaxies by spatially resolving their properties using JWST in order to look through the dust and bridge the gap between the compact FIR sources and the larger optical star-forming galaxies. Based on red-green-blue images from the F115W, F200W, and F444W filters, we divided each galaxy into several uniformly colored regions, fit their respective SEDs, and measured physical properties. After classifying each region as star forming or quiescent, we assigned galaxies to three classes depending on whether active star formation is located in the core, in the disk, or in both. (i) We find that the galaxies at a higher redshift tend to have a fragmented disk with a low core mass fraction. They are at an early stage of bulge formation. When moving toward a lower redshift, the core mass fraction increases, and the bulge growth is associated with a stabilization of the disk, which translates into less patches and clumps. The NIRCam data clearly point toward bulge formation in preexisting disks (ii) Lopsidedness is a very common feature of DSFGs. It has been wrongly overlooked for a long time and could have a major impact on the evolution of DSFGs. (iii) Twenty-three percent of the galaxies have a star-forming core embedded in a quiescent disk. They seem to be undergoing outside-in quenching, often facilitated by their strong lopsidedness inducing instabilities. (iv) We show that half of our galaxies with star formation concentrated in their core are good sub-millimeter galaxy near-IR counterpart candidates, demonstrating that compact SMGs are usually surrounded by a larger, less obscured disk. (v) Finally, we found surprising evidence for clump-like substructures being quiescent or residing in quiescent regions. This work demonstrates the major impact JWST/NIRCam has on understanding the complexity of the evolution of distant massive galaxies regarding bulge formation and quenching mechanisms.

Biosynthesis of alternan-stabilized selenium nanoparticles: A study on characterization and applications for antibacterial and antifungal purposes

In this study, the alternan/selenium nanoparticles (Alt/SeNPs) were characterized with respect to their formation, morphology, size, selenium distribution, molecular, crystallographic, and thermal properties using UV–Vis spectroscopy, SEM, TEM, EDAX, FTIR, XRD, DSC and TGA measurements. UV–VIS measurements confirmed the synthesis of nanoparticles by observing a maximum surface plasmon resonance peak at 212 nm. In this study, alternan contributed to stabilizing the dispersion of SeNPs, resulting in a cluster of spherical and well-dispersed nanoparticles ranging in size from 50 to 90 nanometers. Nanoparticles were found to be highly thermally stable and in a nanocrystalline structure. The ABTS and CUPRAC radical scavenging activities of Alt/SeNPs were remarkable (95% and 78% at 4 and 6 mg/mL levels of Alt/SeNPs, respectively). Alt/SeNPs had also good inhibitory activities (3.5–4.0 and 4–15 mm of inhibition zone levels at 5 mg/mL level of Alt/against foodborne pathogenic bacteria and fungi, respectively).