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Herein, we rationally constructed a hybrid heterostructure comprising porous g-C3N4 (CN)-encapsulated anatase TiO2 hollow spheres (TOHS) via a synthesis method that involves hydrothermal and calcination treatments. The fabricated hybrid, termed CN/TOHS, demonstrated extraordinary activity toward the degradation of environmentally toxic pharmaceutical substances (acetaminophen and ciprofloxacin) in aqueous solutions under simulated sunlight irradiation; the activity of CN/TOHS was superior to that attained for individual TOHS and CN counterparts. In particular, the CN/TOHS hybrid containing 13.3 wt.% of CN on TOHS displayed the optimum degradation activity among the tested catalysts used in this study, and it also possessed exceptional recyclability and stability during consecutive degradation tests. The remarkable photocatalytic activity and stability of the hybrid were predominantly ascribed to the large solid interfacial contact between constituents, TOHS and CN, induced by effective hybrid structure, which boosted the interfacial charge transfer and impeded with the direct recombination of photo-induced charges. Notably, the results of the liquid chromatography–mass spectrometry analysis corroborated the effective mineralization of model pharmaceutical pollutants in the presence of the CN/TOHS hybrid. The simple interfacial engineering strategy presented in this study offers a potential route for the rational design of novel catalysts for application in environmental remediation and solar energy conversion.

The liquefaction resistance and correction factors Kσ and Kα of Nakdong River sand obtained from cyclic triaxial (CTX) tests were compared with those determined by cyclic simple shear (CSS) tests to ascertain the importance of the reduction factor Cr and correction factors Kσ and Kα in liquefaction evaluations, especially in view of the lack of comparative liquefaction assessments based on different laboratory test apparatuses. All samples used for the comparisons were obtained from the same type of sand by using similar preparation methods and they were subjected to similar stress states to minimize the number of factors influencing the comparison results; moreover, the apparatuses used in the two tests were manufactured by the same company and all tests were conducted by a single operator. It was found that the liquefaction resistance in CTX tests was always greater than that in CSS tests. Furthermore, Cr varied from 0.63 to 0.36, and it depended on the relative density Dr and initial static shear ratio α. Kσ, which increased with the normal effective stress σ′nc in CTX tests, was identical to Kσ observed in CSS tests when α was increased up to 0.1. By contrast, Kα in the CSS tests was 58%–97% of Kα measured in the CTX tests, and it depended on the combined effect of Dr, σ′nc, and α. The relationship between Kα and α in both CTX and CSS tests was well represented by a parabolic function. Moreover, the differences in Kα values between the CTX and CSS tests were also found to be a parabolic function of α. This information can be used for converting CTX (or CSS) values into equivalent CSS (or CTX) values.

In this study, an electron-scattering device was fabricated to practically use the ultra-high dose rate electron beams for the FLASH preclinical research in Dongnam Institute of Radiological and Medical Sciences. The Dongnam Institute of Radiological and Medical Sciences has been involved in the investigation of linear accelerators for preclinical research and has recently implemented FLASH electron beams. To determine the geometry of the scattering device for the FLASH preclinical research with a 6-MeV linear accelerator, the Monte Carlo N-particle transport code was exploited. By employing the fabricated scattering device, the off-axis and depth dose distributions were measured with radiochromic films. The generated mean energy of electron beams via the scattering device was 4.3 MeV, and the symmetry and flatness of the off-axis dose distribution were 0.11% and 2.33%, respectively. Finally, the doses per pulse were obtained as a function of the source to surface distance (SSD); the measured dose per pulse varied from 4.0 to 0.2 Gy/pulse at an SSD range of 20–90 cm. At an SSD of 30 cm with a 100-Hz repetition rate, the dose rate was 180 Gy/s, which is sufficient for the preclinical FLASH studies.

To investigate the effect of the vertical effective and initial static shear stresses on cyclic resistance under cyclic loading with principal stress rotation, a series of cyclic direct simple shear tests were conducted on loose and dense Nakdong River sands. The results revealed that the increasing vertical effective stress (σ′v0) often decreased the cyclic resistance, and the decrease was more evident for a high initial static shear ratio (α = 0.2). The degree of reduction of the correction factor Kσ predicted by recommended methods in practice mostly showed more conservative results than the measured Kσ values in this study. Increasing the initial static shear stress decreased the cyclic resistance of the loose sand. For the dense sand, the cyclic resistance either increased or decreased, depending on the combined effect of the σ′v0 and α levels. The correction factor Kα decreased minimally to 0.689 for the loose sand and rose maximally to 1.175 for the dense sand. When the relative density (Dr) increased from 40% to 80%, the increase in the cyclic resistance for a high α (=0.2) was considerably greater than that for α = 0. The cyclic response of the loose sand was due to sudden flow deformation without any apparent shear strain accumulation, regardless of the α value; while the cyclic response of the dense sand indicated plastic strain accumulation. Thus, the cyclic resistance of sand is influenced by the combined effect of Dr, σ′v0, and α, with the potential influence of principal stress rotation.

For five B2O3–Bi2O3 glasses, detailedly, γ, neutron, & proton, alpha, and electron (charged particles) shielding efficacies were assessed in this work. The crucial photon attenuating (interaction probabilities) parameter i.e., mass attenuation coefficient (μ/ρ) was calculated by Phy-X/PSD software and procured μ/ρ results have been verified through MCNPX, Geant4, & FLUKA codes μ/ρ findings from which a quality unanimity among them was noticed over an energy range of 15 KeV–15 MeV. Following μ/ρ & linear attenuation coefficient (μ) outcomes, Zeff, Neff, HVL, TVL, and MFP have been reckoned and found that all μ/ρ, Zeff, Neff, HVL, TVL, & MFP highly rest on glass chemical contents & photon energy. Zeq and by applying geometric progression (G‒P) fitting parameters (a, b, c, d, & Xk coefficients) EBFs & EABFs were appraised at ten specific penetration depths up to 40 mfp, at energy range of 0.015–15 MeV. The inferred RPE quantities confirmed all chosen glasses quintessential absorption competence for lower energy γ-rays. Utilizing SRIM code the mass stopping powers (MSPs) & projected ranges (PRs) for protons ((ΨP)&(ΦP)) and alpha particles (ΨA)&(ΦA), and with the help of ESTAR database, electron MSP (ΨE) & continuous slowing down approximation (CSDA) ranges for electrons have been approximated at 0.015–15 MeV KE. The fast neutron removal cross-sections (ΣR) were estimated and obtained ΣR was diversified at 0.10978–0.12144 cm−1 range relying on Bi2O3 inclusion in glasses. Based on all acquired outputs, 57.5B2O3-42.5Bi2O3 (mol%) glass possesses superior attenuation capacity for γ-rays and fast neutrons as well as charged particles.

γ-ray, fast and thermal neutrons shielding features for five Pb-free {[(TeO2)0.70(B2O3)0.30]0.7 (ZnO)0.30}(1-x)(La2O3)x (x = 0.01, 0.02, 0.03, 0.04, and 0.05 mol%) glasses have been inspected in this work. For all samples, within the photon energy range of 0.015–15 MeV, linear attenuation coefficients (μ) and mass attenuation coefficients (μ/ρ) were estimated using WinXCOM program (theoretical approach), and obtained μ/ρ values are in fine agreement with computed μ/ρ results of respective MCNP5, Geant4, and Penelope codes. By utilizing μ/ρ values of WinXCOM, γ-ray attenuation parameters like effective atomic number (Zeff), effective electron density (Neff), half-value layer (HVL), and mean free path (MFP) were assessed within 0.015–15 MeV photon energy range, for all samples. Additionally, exposure buildup factors (EBFs) and energy absorption buildup factors (EABFs) were calculated for all samples by applying a five parameter geometric progression (G‒P) fitting method as a function of various penetration depths (1, 5, 10, 15, 20, 25, 30, 35, and 40 mfp) within 0.015–15 MeV photon energy range. The derived radiation protection efficiency (RPE) results indicate all samples' effective attenuation competence for lower energy γ-rays. Among all glasses, 46.55TeO2-19.95B2O3-28.5ZnO–5La2O3 (mol%) sample, by having relatively bigger μ/ρ and Zeff, minimal HVL and MFP, and lowest EBF and EABF, endorse its' excellent γ-ray shielding effectiveness. Further, neutron shielding parameters such as macroscopic removal cross-section for fast neutrons (ΣR), coherent and incoherent scattering cross-sections (σcs & σics), absorption cross-section (σA), and total cross-section (σT) for thermal neutrons were explored. By using the Geant4 code, ‘σT’ values have been deduced within 10−4‒10−8 MeV neutron energy range. The 46.55TeO2-19.95B2O3-28.5ZnO–5La2O3 (mol%) glass owns relatively larger ΣR (0.1474 cm−1) for fast neutrons attenuation and ‘σT’ (10.1444 cm−1 at 0.0253 eV neutron energy, 15.9824 cm−1 → 0.551 cm−1 from 1 × 10−8 MeV →1 × 10−4 MeV neutron energy) for thermal neutrons absorption, respectively, revealing its' superior neutrons shielding ability.

Amorphous structures of the as-cast bulk metallic glass samples (BMGs) of Cu60Zr25Ti15 and (Cu60Zr25Ti15)95Ni5 alloys are confirmed by X-ray diffraction. Isothermal crystallization kinetics of these BMGs are investigated using differential scanning calorimetry. For both the alloys, the apparent activation energy (Ea) shows a strong dependency on crystallization volume fraction (x). Isothermal crystallization kinetic parameters are calculated by Arrhenius and Johnson–Mehl–Avrami equations. Avrami exponential factor (n) is also found to show clear correlation with the crystallization volume fraction (x). It is found that the crystallization process is easier in Cu60Zr25Ti15 BMG than in (Cu60Zr25Ti15)95Ni5 BMG as the Ea decreases constantly for the former alloy though in the case of second alloy, the Ea is almost unchanged up to x = 60%. For both the alloys, nucleation activation energy (Enucleation) is found to be higher than that of growth activation energy (Egrowth). This indicates that the growth of crystals during isothermal crystallization in these glasses is easier than nucleation, and the minor addition of Ni causes the higher thermal stability against crystallization in isothermal condition.

Recently, applications of biomass-based plastics have increased according to the eco-friendly policy of the reduction of carbon dioxide emissions in domestic and foreign government. In this study, a paper plastic composite was produced by compounding polypropylene and micronized paper powder that was prepared using dry pulverization technology. Subsequently, the specimen of paper plastic was verified with mechanical properties, formability and product safety test to confirm the suitable packaging materials for food packaging. Paper plastics showed slightly lower mechanical properties than currently commercialized PP composites. However, paper plastics are valuable materials as environmentally friendly carbon-reducing material because of high biocarbon content, light weight features and applicability of existing manufacturing machines or system.

A 9-MeV electron linear accelerator based on C-band microwaves for medical applications is being assembled at the Dongnam Institute of Radiological and Medical Sciences (DIRAMS). The accelerating column has an on-axis coupled structure and will be operated with a π/2-mode standing wave. Parameters of the cavities are selected based on simulations with CST MICROWAVE STUDIO® (CST MWS), and the cold test and micro-machining are performed to obtain the desired RF characteristics of the cavity. Then, the bead-pull test is conducted to measure the RF properties of the full accelerating column structure. The fabrication of the C-band accelerating column and the results of the low-power RF tests are discussed.

A uniform electron field is required for medical applications of electron linear accelerators (LINACs). Electron irradiation devices, including scattering foils and applicators for generating uniform electron fields, are widely used in medical LINACs. In this research, an electron scattering device consisting of scattering foils and applicators was designed for clinical application of a 9-MeV electron LINAC planned at the Dongnam Institute of Radiological & Medical Sciences. Monte Carlo simulations were performed to calculate the depth dose and the beam profile curves in a water phantom by using the EGSnrc Monte Carlo code.

The 6-MeV C-band standing-wave accelerator was constructed in 2015 and is providing for the beam service. The new 9-MeV accelerator was designed and constructed in 2018 at the Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan, Korea. The 5712 MHz accelerating column was designed with an average accelerating gradient of 16.7 MV/m at a pulsed resonance frequency (RF) power of 2.5 MW. The C-band coaxial magnetron was chosen for its high RF power of 2.5 MW and RF frequency of 5712 ± 10 MHz. While the 6-MeV accelerator was operating using a magnetron manufactured by BVERI, China, the 9-MeV accelerator uses a magnetron manufactured by CPI, USA. Though the CPI magnetron requires more heating power and precise heating control for high repetition operation, the frequency spectrum and the RF power distribution are satisfactory for our accelerating columns. The magnetron installed on the 9-MeV accelerator was tested with the 6-MW pulse modulator based on the thyratron-switched pulse-forming network and is currently operating for accelerator RF conditioning. In this paper, we present a brief description of the 9-MeV accelerator, the integration of the RF transport systems and the commissioning status. We also discuss the results obtained during the early commissioning and future plan.

Gamma-rays and fast and thermal neutron attenuation features of (Bi2O3)x–(TeO2)(100−x) (where x = 5, 8, 10, 12, and 15 mol%) and [(TeO2)0.7–(B2O3)0.3](1−x)–(Bi2O3)x (where x = 0.05, 0.10, 0,15, 0.20, 0.25, and 0.3 mol%) glass systems have been explored and compared. For all samples, mass attenuation coefficients (μ/ρ) are estimated within 0.015–15 MeV photon energy range by MCNP5 simulation code and correlated with WinXCom results, which showed a satisfactory agreement between computed μ/ρ values by these both methods. Additionally, effective atomic number (Zeff), effective electron density (Neff), half-value layer (HVL), tenth-value layer (TVL), mean free path (MFP), total atomic cross-section (σa), and total electronic cross-section (σe) are calculated by utilizing μ/ρ values. The μ/ρ, Zeff, and Neff are energy dependent and have higher values at the lowest energy and smaller values at higher energies. Moreover, using the G–P fitting method as a function of penetration depth (up to 40 mfp) and incident photon energy (0.015–15 MeV range), exposure buildup factors (EBFs) and energy absorption buildup factors (EABFs) are evaluated. Both 85TeO2–15Bi2O3 (mol%) and 49TeO2–21B2O3–30Bi2O3 (mol%) samples, by possessing higher values of Zeff, exhibit minimum EBF and EABF values. Highest μ/ρ, Zeff values and lowest HVL, TVL, MFP values of 49TeO2–21B2O3–30Bi2O3 (mol%) sample indicated its better gamma-ray absorption capability among all selected glasses. Further, macroscopic effective removal cross-section for fast neutrons (ΣR), coherent scattering cross-section (σcs), incoherent scattering cross-section (σics), absorption cross-section (σA), and total cross-section (σT) values for thermal neutron attenuation have been computed. Among all samples, 49TeO2–21B2O3–30Bi2O3 (mol%) glass possesses a better ΣR value for fast neutron attenuation, while the largest ‘σT’ value of 66.5TeO2–28.5B2O3–5Bi2O3 (mol%) sample suggests its good thermal neutron absorption efficiency.

Authors aim to study multicomponent barium bismuth borate glasses doped with Dy3+ (1 mol%) for white light-emitting diodes (WLEDs) application. All samples, synthesized through melt-quench approach, were characterized by XRD, optical absorption, excitation, emission, and decay lifetimes. Oscillator strengths and Judd–Ofelt intensity parameters (Ω2, Ω4, Ω6) for all glasses were computed from absorption spectra and further, radiative emission transition probability (AR), branching ratio (βR), and radiative lifetime (τR) were estimated for Dy3+ ion various excited states using J–O parameters. Upon 350 nm excitation, 4I15/2 → 6H15/2 [454 nm (blue)], 4F9/2 → 6H15/2 [483 nm (blue)], 4F9/2 → 6H13/2 [575 nm (yellow)], and 4F9/2 → 6H11/2- [663 nm (red)] emission transitions were observed among which 4F9/2 → 6H13/2 transition exhibits the highest intensity. Dy3+: Li glass showed relatively higher PL intensity and quantum efficiency than Dy3+: Na and Dy3+: K samples. Calculated CIE chromaticity (x = ~ 0.35, y = ~ 0.39) coordinates (λex.: 350 nm) and CCTs (4749‒4890 K) proclaimed overall neutral white light emission from all samples, implying their suitability for WLED applications. Decay lifetimes (τexp) were determined for Dy3+: 4F9/2 → 6H13/2 transition. Additionally, stimulated emission cross-section ($$\sigma^{\text{E}}_{\text{p}}$$) and gain bandwidth ($$\sigma^{\text{E}}_{\text{p}}$$ × Δλeff) were calculated for respective blue and yellow emission transitions.

Dental crowns are used to restore decayed or chipped teeth, where their surfaces play a key role in this restoration process, as they affect the fitting and stable bonding of the prostheses. The surface texture of crowns can interfere with this restoration process, therefore the measurement of their inner surface roughness is very important but difficult to achieve using conventional imaging methods. In this study, the inner surfaces of dental crowns were three-dimensionally (3D) visualized using swept-source optical coherence tomography (SS-OCT) system. Nine crowns were fabricated with a commercial 3D printer using three different hatching methods (one-way, cross, and 30° angle counter-clockwise) and three different build direction angles (0°, 45°, and 90°). In addition, an image processing algorithm was developed, which uses morphological filtering, boundary detection, and a high-pass frequency filtering technique, to quantitatively evaluate the inner surface roughness of the dental crowns cross-sections with the depth-of-focus set to match two different regions. The averaged smoothness of fabricated crown was effectively produced using the cross-hatching and the build direction angle of 90° by the respective process. Thus, the results confirm the potential use of this methodology to determine the best parameters to use in 3D fabrication for improving the effectiveness and stability of dental prostheses.

For B2O3-Bi2O3-BaO glass system, γ, proton, alpha, electron, and neutron radiation shielding aspects were examined. Adopting Phy-X/PSD software, mass attenuation coefficients (μ/ρ) have been derived, and such μ/ρ quantities are in good unanimity with evaluated FLUKA, Geant4, and MCNPX codes corresponding μ/ρ end products. Equivalent atomic number and up to 40 mfp ‘buildup factors’ (utilizing G–P fitting procedure) were reckoned at ten distinct penetration depths. Deduced radiation protection efficiency values validated all glasses’ laudable absorption potential for the minimal energy photons. At 15–15 × 103 KeV kinetic energy range, alpha particle and proton mass stopping powers and projected ranges by SRIM code including electron mass stopping power using ESTAR database were evaluated. For fast neutrons, the calculated macroscopic effective removal cross-section (ΣR) reveals that 25B2O3-70Bi2O3-5BaO (mol%) sample owns proportionately larger ΣR (=0.1206 cm–1). 70B2O3-15Bi2O3-15BaO (mol%) glass exhibits the largest total cross-section for thermal neutron absorption. Further, various physical features and elastic (Young’s, bulk, shear, and longitudinal) moduli and Poisson’s ratio values were derived for all samples. Both BC (bond compression) and M-M (Makishima–Mackenzie) models have been utilized for elastic aspects evaluation, and such features are altered considerably with Bi2O3 increment in the studied glasses. By BC and M-M models, obtained Poisson’s ratio is varied at 0.2434 – 0.2749 and 0.2384 – 0.2826 ranges respectively.

For five Ga2O3-Bi2O3-B2O3 composition glasses for improved Bi2O3 content at 25 to 65 mol% (10% continuously each time) at a fixed 10 mol% Ga2O3 amount, distinct physical and mechanical aspects and nuclear radiation attenuation factors were investigated. Increased Λ (optical basicity) values with a gradual Bi2O3 addition indicate studied samples’ improving basic character. Applying BC (bond compression) model key mechanical traits such as Ybc (Young’s modulus), Kbc (bulk modulus), S (shear modulus), L (longitudinal modulus), and σ (Poisson’s ratio) are evaluated where in all glasses 10Ga2O3-65Bi2O3-25B2O3 (mol%) sample exhibits superior elastic moduli. Enhanced Bi2O3 causes for compactness of the gallium borate network as ǹc (average cross-link density) improves from 2.3 to 3.4 indicating increased rigidity of glasses. Later, PHITS, FLUKA, and MCNPX codes are wielded to derive μ/ρ (mass attenuation coefficient) of all selected samples for photons having energy ranging from 15 KeV to 15 MeV. Simulated μ/ρ quantities exactitude is tested via Phy-X/PSD and WinXCOM programs’ μ/ρ results and identified a fairly good harmony among them. With photon energy, MFP (mean free path), TVL (tenth-value layer), and HVL (half-value layer) values variations show a similar tendency and against the trend which noticed for μ/ρ and μ (linear attenuation coefficient) values. 10Ga2O3-65Bi2O3-25B2O3 (mol%) sample’s MFP and HVL are correlated with five commercial γ-ray glass shields’ respective values at 1.25 MeV, 0.662 MeV (137Cs), and 0.2 MeV energies. Further, Zeq (equivalent atomic number) and using G–P (geometric progression) fitting approach for ten individual PDs (penetration depths) within 1–40 mfp range at 15 – 15 × 103 KeV energy region BUFs (buildup factors) were estimated. Attained RPE (radiation protection efficiency) findings attest all chosen Ga2O3-Bi2O3-B2O3 glasses’ competent absorption capacity for lower energy photons. Next, α-particles and protons MSPs (mass stopping powers), i.e. ΨA and ΨP and PRs (projected ranges), i.e. ΦA and ΦP by utilizing SRIM code as well as for electrons MSPs (ΨE) and CSDA (continuous slowing‐down approximation) ranges by ESTAR database have been calculated within 15–15 × 103 KeV KE (kinetic energy) range. Also, ΣR (fast neutron removal cross-section) and for 0.253 × 10–4 KeV energy neutrons σT (total cross-section) and SP (shielding percentage) values were approximated. With Bi2O3 addition, realized ΣR is changed at 0.1161–0.1213 cm−1 extent. For thermal neutrons absorption, 10Ga2O3-25Bi2O3-65B2O3 (mol%) glass shows larger σT (=17.534 cm−1) and at any considered thickness higher SP whereas 10Ga2O3-65Bi2O3-25B2O3 (mol%) (lead-free) glass has better attenuating features for photons affirming the incorporated Bi2O3 favorable effect.

In this study, an engineering characteristic test was conducted on cement milk using expansive additives during the construction of bored piles. Expansive additive mixtures with various mixing ratios were prepared according to the construction standards of the Korea Expressway Corporation. Segregation resistance, compressive strength, frictional resistance stress, scanning electron microscope images, porosity, and economic feasibility were analyzed. It was found that segregation effects due to expansive additive incorporation were insignificant, and it was confirmed that all specimens exceeded 0.5 N/mm2, the compressive strength standard of the Korea Expressway Corporation pile bearing capacity. Given a water–binder ratio of 83% mixed with 10% expansive additives, frictional resistance increased up to ~35%, skin friction force was significantly improved, and a cost-saving effect of up to ~33.24% was achieved.

The use of nontraditional soil stabilizers increases. Various new soil binding agents are under study to augment renewability and sustainability of an earth structure. However, despite increasing interest involved in red clay, there is minimal research investigating the stabilizing red clay with polymer. This paper presents the findings obtained by applying the acrylic polymer and epoxy emulsion as binding agent for red clay and that for sand. The epoxy–hardener ratio, amount of epoxy emulsion, and amount of polymer aqueous solution were manipulated to quantify their effects on red clay and sand, respectively. After compacting a pair of cylindrical samples of which diameter and height are 5 cm and 10 cm, respectively, it is cured for 3 and 7 days in a controlled condition. Each pair is produced to represent the engineering performance at each data point in the solution space. An optimal composition of the binding agents for red clay and that for sand mixture are identified by experimenting every data point. In addition, given lime into each sample, the maximum unconfined compressive strength (UCS) endured by red clay sample and that by sand sample are 2243 and 1493 kPa, respectively. The UCS obtained by the sample mixed with clay and sand reaches 2671 kPa after seven days of curing. It confirms that the addition of lime remarkably improves the UCS. When the clay–sand mixture, of which the ratio is 70:30, includes 5% lime, the UCS of the mixture outperforms. Indeed, these findings, i.e., the optimal proportion of components, may contribute to the increase of initial and long-term strength of an earth structure, hence improving the renewability and sustainability of the earth construction method.

For six 1 mol% Tm3+-doped B2O3-BaO-ZnO-LiF glasses containing single and mixed alkali oxides (fabricated by melt-cast approach), optical absorption, and visible and near-infrared (NIR) fluorescence features including visible luminescence decay times were explored. Optical band gaps, Urbach energy, and two-photon absorption coefficients were evaluated for all studied glasses. Judd–Ofelt (J–O) analysis from absorption spectra was performed to compute Tm3+: 4f–4f transitions J–O parameters Ωλ (λ = 2, 4, 6), and utilizing Ω2, Ω4 and Ω6 values radiative transition probabilities (AR), branching ratios (βR), and radiative lifetimes (τR) for all Tm3+ ion’s excited levels were assessed. For obtained intense blue emission band (454 nm) upon 358 nm excitation, various parameters considered in developing visible laser systems were calculated. Tm3+: Na ions having sample exhibits high AR, highest peak emission cross-section ( σ max em ) (=5.89 × 10–21 cm2) and gain bandwidth ( σ max em × Δλeff) (=9.69 × 10–27 cm3) for 1D2→3F4 luminescence transition in all glasses for a favorable blue lasing process. All emission decay curves of the 1D2 upper level showed nonexponential nature. Commission Internationale de l'eclairage (CIE) coordinates, color purity, and luminous efficiency of radiation were derived from visible fluorescence spectra, and attained CIE (x,y) coordinates values reflect the purplish-blue light region. Under direct optical pumping of 3H6→3H4 transition using 808 nm laser diode, NIR fluorescence spectra exhibit a wideband within 1.3–1.6 μm spectral range peaked at 1.46 μm (3H4→3F4 transition). NIR emissions effective bandwidth (Δλeff) was varied relying on different alkali oxides. Δλeff ~ 121 nm was deduced for Tm3+: Li ions comprising glass with large σ max em (=1.832 × 10–21 cm2), high ( σ max em × Δλeff) (=2.22 × 10–26 cm3), and optical gain (=12.608 × 10–25 cm2s) for 3H4→3F4 emission transition and its gain profile wraps the entire S-optical communication band range for efficient broadband amplification purpose in wavelength-division multiplexing systems.

In this paper, a series of combustion tests using PMMA/O2 was conducted to examine the initiating characteristics of low frequency instability (LFI) in relation to the changes in both flow and combustion conditions. By selecting parameters such as the oxidizer mass flow rate, fuel grain length, and mixing ratio of mixture oxidizer composed of oxygen and nitrogen; combustion tests were conducted to vary the equivalence ratio in the combustion. This study further validated instability characteristics in connection with coupling behavior between the high frequency pressure and heat release oscillations in 500 Hz band. Based on the results, a combustion stability map was plotted and it shows that the initiation of LFI is contingent upon the satisfaction of specific conditions of flow and combustion. The results also confirmed that the initiation of LFI is highly linked to an establishment of a positive coupling between high frequency pressure and heat release oscillations. In addition, equivalence ratio was found to be a critical factor in the transition of coupling status between the two high frequency oscillations. For a given flow condition, the sole increase in equivalence ratio above a certain threshold resulted in the phase shift between the two oscillations leading to a positive coupling or vice versa.

We demonstrate high-resolution light-emitting diodes based on well-defined nanoarrays of colloidal quantum dots (QDs) with different sizes in a large area using nanoporous templates. To fabricate t...

Novel thermally activated delayed fluorescence (TADF) emitters were designed with diphenylsulfone (DPS) as an electron acceptor and carbazole derivatives as electron donors and their electr...

Against photon energies extending from 0.015 to 15 MeV, MCNPX, FLUKA and PHITS codes are operated to simulate mass attenuation coefficients (μ/ρ) for a total of ten B2O3-Bi2O3-Li2O glass compositions with added Bi2O3 amount from 10 to 55 mol% (5 mol% growth gradually) as a substitute for total (B2O3 + Li2O) mol% content. All the computed μ/ρ values correctness is examined by Py-MLBUF and WinXCOM programs’ μ/ρ outcomes and we found a good agreement among them. 55Bi2O3-35B2O3-10Li2O (mol%) glass half-value layer (HVL) and mean free path (MFP) quantities are compared with distinct commercial γ-ray attenuating glasses, alloys, polymers, concretes and lead and ceramics corresponding values. Next, equivalent atomic numbers (Zeq) and by employing geometric progression (G–P) fitting method at 1–40 mfp PDs (penetration depths), at 0.015–15 MeV energy range ‘buildup factors’ were calculated. At all chosen twenty-five energies derived radiation protection efficiency (RPE) results assured investigated samples exemplary competence for low energy photons absorption. Applying SRIM codes ΨP and ΦP and ΨA and ΦA (mass stopping powers (MSPs) and projected ranges (PRs) for protons and α-particles), and making use of ESTAR database ΨE (electron MSP) and continuous slowing‐down approximation (CSDA) range for electrons are determined at KE (kinetic energy) range of 0.015–15 MeV. Moreover, fast neutron removal cross-sections (ΣR), for 0.0253 eV energy neutrons absorption cross-sections have been estimated. Deduced ΣR was altered at 0.1105–0.1205 cm−1 range with Bi2O3 inclusion in studied samples. 10Bi2O3-70B2O3-20Li2O (mol%) glass has greater total cross-section (=23.251 cm−1) for thermal neutrons absorption while 55Bi2O3-35B2O3-10Li2O (mol%) sample exhibits quality shielding factors for photons and fast neutrons confirming the included Bi2O3 positive impact. Along with nuclear attenuation features various physical and mechanical aspects are also inspected. Derived Vm (molar volume), OPD (oxygen packing density), Vo (oxygen molar volume), Vt (packing density) and Gt (dissociation energy per unit volume) values indicated glasses rigidity. Following Makishima–Mackenzie's theoretical model primary mechanical features like Y, K, S and L (Young's, bulk, shear and longitudinal modulus) and σ (Poisson's ratio) are evaluated where 10Bi2O3-70B2O3-20Li2O (mol%) glass shows better elastic moduli in all samples.

For six 1 mol% Pr3+-doped B2O3–Bi2O3–ZnO–NaF glasses consisting of single and mixed alkali oxides, optical absorption and visible and near-infrared (NIR) luminescence traits including visible fluorescence decay times were investigated. Judd–Ofelt (J‒O) analysis from absorption spectra was performed to calculate J‒O parameters Ωλ (λ = 2, 4, 6) by including and omitting 3H4 → 3P2 transition. Utilizing Ω2, Ω4, and Ω6 values and refractive indices, radiative transition probabilities (AR), branching ratios (βR), and radiative lifetimes for all Pr3+ ion's luminescent levels were estimated. For observed intense blue fluorescence band upon 443 nm optical pumping, various parameters considered in designing visible laser systems were evaluated. Pr3+: Na + K ions comprising glass possesses large spectroscopic quality factor, high AR and βR, large stimulated emission cross-section (σem), high quantum efficiency, large gain bandwidth, and significant optical gain for 3P0 → 3H4 transition for a potential blue lasing action among all samples. Further, Commission Internationale de l'eclairage (CIE) coordinates, correlated color temperature (CCT), color rendering index, and luminous efficiency of radiation were derived from visible luminescence spectra and deduced CIE and CCT values represent the neutral or warm white light region. Upon 3H4 → 3P2 excitation, NIR luminescence spectra show 3P1 + 1I6 → 1G4, 1D2 → 3F4, and 1D2 → 1G4 transitions in which broadband (1D2 → 1G4) at 1.3–1.65 μm range with effective bandwidth ~157 nm was obtained for Pr3+: Na + K ions constituting glass with high AR (1938 s−1), moderate βR (26%), and large σem (2.64 × 10−20 cm2) at 1.472 μm, and its gain profile covers the E-+S-+C-optical communication bands' range for effective broadband amplification operation.

For both the B2O3-Bi2O3-CaO and B2O3-Bi2O3-SrO glass systems, γ-ray and neutron attenuation qualities were evaluated. Utilizing the Phy-X/PSD program, within the 0.015–15 MeV energy range, linear attenuation coefficients (µ) and mass attenuation coefficients (μ/ρ) were calculated, and the attained μ/ρ quantities match well with respective simulation results computed by MCNPX, Geant4, and Penelope codes. Instead of B2O3/CaO or B2O3/SrO, the Bi2O3 addition causes improved γ-ray shielding competence, i.e., rise in effective atomic number (Zeff) and a fall in half-value layer (HVL), tenth-value layer (TVL), and mean free path (MFP). Exposure buildup factors (EBFs) and energy absorption buildup factors (EABFs) were derived using a geometric progression (G–P) fitting approach at 1–40 mfp penetration depths (PDs), within the 0.015–15 MeV range. Computed radiation protection efficiency (RPE) values confirm their excellent capacity for lower energy photons shielding. Comparably greater density (7.59 g/cm3), larger μ, μ/ρ, Zeff, equivalent atomic number (Zeq), and RPE, with the lowest HVL, TVL, MFP, EBFs, and EABFs derived for 30B2O3-60Bi2O3-10SrO (mol%) glass suggest it as an excellent γ-ray attenuator. Additionally, 30B2O3-60Bi2O3-10SrO (mol%) glass holds a commensurably bigger macroscopic removal cross-section for fast neutrons (ΣR) (=0.1199 cm−1), obtained by applying Phy-X/PSD for fast neutrons shielding, owing to the presence of larger wt% of ‘Bi’ (80.6813 wt%) and moderate ‘B’ (2.0869 wt%) elements in it. 70B2O3-5Bi2O3-25CaO (mol%) sample (B: 17.5887 wt%, Bi: 24.2855 wt%, Ca: 11.6436 wt%, and O: 46.4821 wt%) shows high potentiality for thermal or slow neutrons and intermediate energy neutrons capture or absorption due to comprised high wt% of ‘B’ element in it.

MCNPX, Geant4 and FLUKA codes are employed to compute mass attenuation coefficients (μ/ρ) for 20Bi2O3-(80-x)B2O3-xPbO (x = 0, 20, 30, 40 and 60 mol%) glasses at 20, 30, 40 and 60 KeV, 133Ba (81, 161, 223, 276, 303, 356 and 384 keV), 57Co (122 and 136 KeV), 22Na (511 and 1275 keV), 137Cs (662 keV), 54Mn (835 keV), 60Co (1173 and 1333 keV) and 42K (1524 keV) photon peaks where 20, 30, 40 and 60 KeV energies are utilized for Mammography, Dental, General and Computed tomography (CT) scanning accordingly, in this study. All simulated μ/ρ outcomes accuracy was verified by WinXCOM and Phy-X/PSD programs’ μ/ρ findings and we noticed a satisfactory agreement among them. From μ/ρ and linear attenuation coefficient (μ) values effective atomic number (Zeff), effective electron density (Neff), half-value layer (HVL), tenth-value layer (TVL) and mean free path (MFP) have been determined. 20Bi2O3-20B2O3-60PbO (mol%) glass HVL and MFP have been compared with some commercial glasses, alloys, polymers, concretes and lead and ceramics corresponding values. Later equivalent atomic numbers (Zeq) and applying geometric progression (G–P) fitting method at 1 – 40 mfp penetration depths (PDs) at 0.015–15 MeV energy range exposure buildup factors (EBFs) and energy absorption buildup factors (EABFs) were estimated. At all selected twenty energies derived radiation protection efficiency (RPE) results confirmed studied samples’ excellent efficacy for low energy photons absorption. Moreover, applying SRIM codes mass stopping powers (MSPs) and projected ranges (PRs) for protons and α-particles and utilizing ESTAR database electron MSPs and continuous slowing down approximation (CSDA) range for electrons were determined at kinetic energy (KE) range of 0.015–15 MeV. Further fast neutron removal cross-sections (ΣR), for 0.0253 eV energy neutrons coherent and incoherent scattering cross-sections (σcs and σics), absorption cross-section (σA) and total cross-section (σT) quantities were evaluated. Derived ΣR was changed at 0.1166–0.123 cm−1 range depending on PbO addition in chosen samples. 20Bi2O3-80B2O3 (mol%) glass has larger σT (23.094 cm−1) in all studied samples for thermal neutron absorption while 20Bi2O3-20B2O3-60PbO (mol%) sample shows superior attenuation factors for photons and fast neutrons signifying included PbO positive effect.

Magnetic nanoparticles (MNPs) are widely used materials for biomedical applications owing to their intriguing chemical, biological and magnetic properties. The evolution of MNP based biomedical applications (such as hyperthermia treatment and drug delivery) could be advanced using magnetic nanofluids (MNFs) designed with a biocompatible surface coating strategy. This study presents the first report on the drug loading/release capability of MNF formulated with methoxy polyethylene glycol (referred to as PEG) coated MNP in aqueous (phosphate buffer) fluid. We have selected MNPs (NiFe2O4, CoFe2O4 and Fe3O4) coated with PEG for MNF formulation and evaluated the loading/release efficacy of doxorubicin (DOX), an anticancer drug. We have presented in detail the drug loading capacity and the time-dependent cumulative drug release of DOX from PEG-coated MNPs based MNFs. Specifically, we have selected three different MNPs (NiFe2O4, CoFe2O4 and Fe3O4) coated with PEG for the MNFs and compared their variance in the loading/release efficacy of DOX, through experimental results fitting into mathematical models. DOX loading takes the order in the MNFs as CoFe2O4 &gt, NiFe2O4 &gt, Fe3O4. Various drug release models were suggested and evaluated for the individual MNP based NFs. While the non-Fickian diffusion (anomalous) model fits for DOX release from PEG coated CoFe2O4, PEG coated NiFe2O4 NF follows zero-order kinetics with a slow drug release rate of 1.33% of DOX per minute. On the other hand, PEG coated NiFe2O4 follows zero-order DOX release. Besides, several thermophysical properties and magnetic susceptibility of the MNFs of different concentrations have been studied by dispersing the MNPs (NiFe2O4, CoFe2O4 and Fe3O4) in the base fluid at 300 K under ultrasonication. This report on the DOX loading/release capability of MNF will set a new paradigm in view that MNF can resolve problems related to the self-heating of drug carriers during mild laser treatment with its thermal conducting properties.

In this research, thermally conductive polyamide 6/hexagonal boron nitride (PA6/hBN) nanocomposites waaere fabricated via an in-situ ring-opening polymerization of e-caprolactam. The hBN filler was exfoliated through a co-solvent exfoliation process and then chemically modified to form an e-caprolactam-grafted BN (cBN). After that, PA6 was introduced onto the cBN surface using a grafting from method. The thermal conductivities of the PA6/cBN composites significantly increased up to 180 % when the BN content was 16.5 wt%. The tensile strength and Young’s modulus of the PA6/cBN composites with 16.5 wt% hBN increased by 30 % and 92 %, respectively, compared to the pristine PA6. The grafted PA6 on BN composites exhibited strong polymer-filler interfacial interactions. Overall, this study provides a facile method of fabricating high-performance PA6 with improved thermal and mechanical properties and higher thermal conductivity.

In this study, the performance evaluation was performed by adding a polymer aqueous (PA) solution as a new additive of the red clay binder for use in the rammed-earth construction method. The evaluation items were compressive strength, water erosion, shrinkage, crystal structure, and microstructure. As a result of the experiment, the binder was improved by efficiently bonding the silica particles by the polymerized polymer. It was confirmed that adding a PA solution to red clay enhances the compressive strength, which is further improved when 5 wt% poly(Acrylic acid(AA)-co-Acrylamide(AM)) is added to the PA solution. Microstructural analysis indicated that the addition of a PA solution facilitates effective bonding of the silica particles of red clay to form hydrogen bonding with poly(AA-co-AM) and encourages aggregate formation. Therefore, the study confirmed that PA solution can be applied to satisfy the performance requirements of the rammed-earth construction by improving the durability and strength of the binder.

Graphene is one of the most favorite materials for materials science research owing to its distinctive chemical and physical properties, such as superior conductivity, extremely larger specific surface area, and good mechanical/chemical stability with the flexible monolayer structure. Graphene is considered as a supreme matrix and electron arbitrator of semiconductor nanoparticles for environmental pollution remediation. The present review looks at the recent progress on the graphene-based metal oxide and ternary composites for photocatalysis application, especially for the application of the environmental remediation. The challenges and perspectives of emerging graphene-based metal oxide nanocomposites for photocatalysis are also discussed.

In this study, we examined the effects of cement fineness, SO3 content, an accelerating agent, and chemical admixtures mixed with unit weights of cement on concrete early strength using concrete mixtures. C24 (characteristic value of concrete, 24 MPa) was used in the experiment conducted. Ordinary Portland cement (OPC), high fineness and SO3 OPC (HFS_OPC), and Early Portland cement (EPC) were selected as the study materials. The unit weights of cement were set to OPC 330, 350, and 380. Further, a concrete mixture was prepared with a triethanolamine (TEA)-based chemical admixture to HFS. A raw material analysis was conducted, and the compressive strength, temperature history, and maturity (D∙h) were examined. Then, the vertical formwork removal time was evaluated according to the criterion of each country. Finally, the time required to develop concrete strength of 5 MPa was estimated. Results showed that the early strength of concrete mixed with HFS and EPC was greater than that exhibited by concrete with an increased unit weight of cement with OPC. In addition, when HFS was used with EPC, its strength developed early, similar to the trend exhibited by EPC, even at low temperatures.

There have been many studies on the effect of durability and compressive strength on the increase of the mixing rate of admixtures. However, there is no research that can provide a guide on the optimal mixture proportions for maintaining compressive strength and secure durability properties when using local materials. Therefore, the purpose of this article is to assess the durability and engineering performances of concrete based on local fly ash (FA), as well as to derive the optimum CaO content scope for ensuring durability. The results of this study were compared with the results of the previous study of high-volume ground-granulated blast-furnace slag (GGBFS) concrete. To achieve this, tests were carried out by increasing the admixture mixing rate in 10% increments from 0% to 70%. The unit water was set at 175 kg/m3 and the amount of binder was set at 330 kg/m3. It was found that the overall compressive strength of the hardened concrete decreased when the admixture mixing rate increased. In addition, the compressive strength of specimens tended to improve as all the CaO contents of the admixture types increased. When the durability properties were examined, it was found that the relative dynamic elasticity modulus and carbonation depth decreased, and the chloride penetration depth increased as the CaO content increased for both GGBFS and FA. The weight loss rate, however, remained similar. Based on the results of this study, the optimal CaO content that achieved satisfactory engineering and durability properties was found to be between 39% and 48% for FA. The results of this study will be able to offer guidelines for the mixture rates of FA when mixing durable concrete for use in the field. Additionally, these results are expected to be utilized as a basis for determining instructions relating to chemical composition in order to develop binders with improved durability.

&nbsp, Existing rammed earth construction methods have disadvantages such as increased initial costs for manufacturing the large formwork and increased labor costs owing to the labor-intensive construction techniques involved. To address the limitations of the existing rammed earth construction methods, an autonomous rammed earth construction method was introduced herein. When constructing an autonomous rammed-earth construction method, an alternative means of assuring the performance at the initial age of the binder in terms of materials is needed. In this study, in order to satisfy the performance of the red clay binder, epoxy emulsion was added to analyze the compressive strength, water loosening, shrinkage, rate of mass change, and microstructure in the range of the initial age. As a result of the analysis, the applicability of the epoxy emulsion was confirmed as a new additive for application to an autonomous rammed-earth construction method.

This study investigated the physical properties of section-restoration mortar with calcium nitrite (Ca(NO2)2) and carbon dioxide (CO2) nanobubble mixing water to develop materials and methods for the repair and reinforcement of cracks in reinforced concrete (RC) structures. As the calcium nitrite content increased, the generation rate and generated amount of nitrite-based hydration products also increased, owing to the rapid reaction between NO2&minus, ions in calcium nitrite and C3A(Al2O3). Further, the reaction with C3S and C2S was accelerated, thereby increasing the generation rates of Ca(OH)2 and C-S-H. The large amount of Ca2+ ions in these hydration products reacted with CO32&minus, ions in CO2 nanobubble water, thereby increasing the generation of calcite-based CaCO3 in the cement matrix. This appears to have affected strength development and durability improvement via the densification of the structure. These results suggest that the performance of polymer cement mortar for repairing concrete structures can be improved if calcium nitrite and CO2 nanobubble water are properly combined and applied.

In the present study, different amounts, i.e., 1&ndash, 3 v/v% of 1 M ammonium phosphate monobasic, were used as an eco-friendly corrosion inhibitor to mitigate the corrosion of steel rebar exposed to simulated concrete pore (SCP) + 3.5 wt% NaCl solution at a prolonged duration. Potentiodynamic polarization results show that as the amount of inhibitor is increased, the corrosion resistance of steel rebar is increased. The steel rebar exposed to 3% inhibitor-containing SCP + 3.5 wt% NaCl solution exhibited nobler corrosion potential (Ecorr), the lowest corrosion current density (icorr), and 97.62% corrosion inhibition efficiency after 1 h of exposure. The steel rebars exposed to 3% inhibitor-containing SCP + 3.5 wt% NaCl solution revealed higher polarization resistance (Rp) and film resistance (R0) with exposure periods compared to other samples owing to the formation of passive film. The scanning electron microscopy (SEM) of steel rebar exposed to 3% inhibitor-containing SCP + 3.5 wt% NaCl solution showed homogenous and uniform dendritic passive film which covers all over the surface, whereas, bare, i.e., SCP + 3.5 wt% NaCl solution exposed samples exhibited pitting and irregular morphology. Raman spectroscopy results confirm the formation of goethite (&alpha, FeOOH), maghemite (&gamma, Fe2O3), and iron phosphate (FePO4) as a passive film onto the steel rebar surface exposed to 3% inhibitor-containing SCP + 3.5 wt% NaCl solution. These phases are responsible for the corrosion mitigation of steel rebar which are very protective, adherent, and sparingly soluble.

This paper reports the crystallization kinetics of (Cu60Zr25Ti15)99.3Nb0.7 bulk metallic glass under isothermal conditions. Differential scanning calorimetry (DSC) has been employed for isothermal annealing at ten different temperatures prior to the onset of crystallization (To) temperature. X-ray diffraction and transmission electron microscopy have been used to confirm the amorphous structure of the as cast sample. Crystallized volume fractions (x) are calculated from the exothermic peaks of DSC scans. Crystallized volume fractions (x) against time show sigmoidal type of curves as well as the curves become steeper at higher annealing temperatures. Continuous heating transformation diagram has been simulated to understand the stability of the bulk metallic glass. Crystallization kinetics parameters are calculated using Arrhenius and Johnson–Mehl–Avrami equations. Activation energy (Ea) and Avrami exponential factor (n) have exhibited strong correlation with crystallized volume fraction (x). The average activation energy for isothermal crystallization is found to be 330 ± 30 kJ/mol by Arrhenius equation. Nucleation activation energy (Enucleation) is found to be higher than that of growth activation energy (Egrowth). The Avrami exponential factor (n) indicates about the diffusion controlled mechanism of the nucleation and three-dimensional growth.

The polymerizable reduced graphene oxide (mRGO) grafted styrene&ndash, acrylonitrile copolymer composites were prepared via free radical polymerization. The graphene oxide (GO) and reduced graphene oxide (rGO) was reacted with 3-(tri-methoxysilyl)propylmethacrylate (MPS) and used as monomer to graft styrene and acrylonitrile on its surface. The successful modification and reduction of GO was confirmed using Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analyzer (TGA), Raman and X-ray diffraction (XRD). The mRGO was prepared using chemical and solvothermal reduction methods. The effect of the reduction method on the composite properties and nanosheet distribution in the polymer matrix was studied. The thermal stability, electrical conductivity and morphology of nanocomposites were studied. The electrical conductivity of the obtained nanocomposite was very high at 0.7 S/m. This facile free radical polymerization provides a convenient route to achieve excellent dispersion and electrically conductive polymers.

For Pb-free 35B2O3‒35Bi2O3‒(30–x)TeO2‒(x)BaO (x = 5, 10, 15, 20, and 25 mol%) and (90–x)TeO2‒10Bi2O3‒(x)BaO (x = 10, 15, and 20 mol%) glass systems, gamma and neutron (both fast and thermal neutron) radiation shielding features were examined and compared. Within 0.015–15 MeV photon energy, mass attenuation coefficients (μ/ρ), for all samples, which have been assessed using WinXCOM program are in fair agreement with deduced MCNP5 simulation code μ/ρ results. For all selected samples, at the lowest energy, μ/ρ has bigger values whereas at higher energy regions possess lower values. Furthermore, by employing μ/ρ values, effective atomic number (Zeff), effective electron density (Neff), half-value layer (HVL), tenth-value layer (TVL), and mean free path (MFP) are figured out for both glass systems. For studied samples, with the gradual replacement of TeO2 content with BaO, the derived values of Zeff, HVL, TVL, and MFP revealed improved γ-ray shielding potentiality. Besides, within photon energy range of 0.015–15 MeV, exposure build-up factors (EBFs) and energy absorption build-up factors (EABFs) were estimated for all samples by utilizing G‒P fitting method as a function of different penetration depths (0.5, 1, 2, 3, 4, 5, 6, 7, 8, 10, 15, 20, 25, 30, 35, and 40 mfp). The 35B2O3–35Bi2O3–5TeO2–25BaO (mol%) glass relatively larger μ/ρ and Zeff values, lower HVL, TVL, and MFP values, and minimal EBF and EABF values confirm its superior γ-ray attenuation competence among all samples. Additionally, in comparison, HVL and MFP values of 35B2O3–35Bi2O3–5TeO2–25BaO (mol%) sample are lower than the respective values of some commercial γ-ray shielding glasses and different types of standard concretes, signifying its better shielding features than them. Moreover, macroscopic removal cross-section for fast neutrons (ΣR), coherent scattering cross-section (σcs), incoherent scattering cross-section (σics), absorption cross-section (σA), and total cross-section (σT) for thermal neutrons absorption were derived for both glass systems. Among all selected glasses, 35B2O3–35Bi2O3–5TeO2–25BaO (mol%) sample possesses relatively higher ΣR (0.106 cm−1) and ‘σT’ (8.809 cm−1 at 0.0253 eV neutron energy) values for fast and thermal neutrons attenuation, respectively, demonstrating its favorable absorption capability for neutrons.

From 0.1 up to 2.5 mol% Eu3+-doped fluro-telluroborate glasses as red light-emitting components for white-light-emitting diodes (WLEDs) were investigated. Non-periodicity in the atomic arrangements was studied through the XRD pattern. The photoluminescence (PL) spectra were recorded under blue light (464 nm) excitation and analyzed. All the PL spectra exhibit an intense peak at 612 nm for 5D0 → 7F2 transition, revealing their red photoemission. Optimal PL emissions were achieved for 1.0 mol% Eu3+-doped sample. The CIE chromaticity coordinates for all the glasses (x = ~0.69, y = ~0.30) fall within the red color region. The J‒O parameters (Ω2, Ω4) were calculated following the emission spectra of Eu3+-doped samples and the intensity parameters (Ω2>Ω4), as well as the high asymmetry ratio (R/O), indicate the low ionicity in all the studied glasses. Using the J-O parameters, several radiative features like total emission transition probability (AT), branching ratios (radiative (βR) & experimental (βexp)), stimulated emission cross-section ( σ P E ), gain bandwidth ( σ P E × λ e f f ), and optical gain ( σ P E × τrad) were evaluated. All the luminescence decay curves fit well to non-exponential function and decay times were decreased at Eu3+ concentration >0.5 mol%. The evaluated σ P E = 19.684 × 10−21 cm2, β e x p = 0.759, τexp = 1.325 m s, minimum non-radiative relaxation, W N R = 296/s, and 60.78% of quantum efficiency ( η ) for 1.0 mol% Eu3+-doped glass for 5D0 → 7F2 transition indicates its promising features for red light-emitting optical devices and also as a red component in WLEDs.

SiO2-based glasses doped with 1 mol% Er3+ were fabricated via melt-quench process and their structural and visible and NIR (near-infrared) fluorescence features have been investigated. Calculated Judd–Ofelt (J–O) intensity parameters that were deduced from absorption spectra are applied to reckon different radiative factors. Visible emission spectra and decay profiles (for 4S3/2 → 4I15/2 transition) were registered upon λexci.= 379 nm. CIE (Commission International de I'Eclairage), CCT (correlated color temperature), and CP (color purity) values were evaluated from the emission spectra. Also, a NIR luminescence band (4I13/2 → 4I15/2 transition) was identified by 980 nm LD (laser diode). Later, emission cross-section [(σemi) stimulated, (σMemi) from Mccumber theory] values were computed for observed NIR emission. Highest σemi and gain bandwidth (σemi × ∆λeff) were obtained to be 9.18×10−21 cm2 and 517×10−28 cm3 accordingly for 4I13/2 → 4I15/2 transition.

The development of a cost-effective, high-performance, and stable electrocatalyst capable of producing clean and renewable hydrogen via water splitting is challenging. This study demonstrates a remarkable electrocatalytic water-splitting activity in alkaline media by employing a bioinspired, noble-metal-free vitamin B12 (VB12) catalyst on a conductive graphene substrate. VB12 could inherently produce unique Co–N4 active sites upon thermal treatment owing to its Co-centered macrocyclic corrin ring, and VB12 was further engineered to produce additional Fe–Nx sites through the incorporation of Fe as a secondary metal cation. The optimal Fe content in VB12 resulted in a high density of exposed Co–N4 and Fe–Nx active sites. Consequently, the optimized catalyst, denoted as Fe–VB12-2@GR, demonstrated outstanding bifunctional electrocatalytic performance, with overpotentials of only 120 and 300 mV at 10 mA cm−2 for the hydrogen and oxygen evolution reactions, respectively, while maintaining high stability and durability over a period of 20 h. The cell voltage required for water splitting was calculated as ∼1.65 V at 10 mA cm−2. This work demonstrates a state-of-the-art design of a bioinspired catalyst for water electrolysis, and thus, we believe that this work has the potential to bring considerable advancements in clean and renewable energy technologies.

We present a simple, versatile approach to generate highly ordered nanostructures of block copolymers (BCPs) using rubbed surfaces. A block of poly(tetrafluoroethylene) (PTFE) was dragged across a flat substrate surface above the melting point of PTFE transferring a highly aligned PTFE topographic pattern to the substrate. Si wafer, glass, and polyimide films were used as substrates. Thin films of cylinder-forming asymmetric polystyrene-block-poly(2-vinylpyridine) copolymers (S2VPs) were solvent annealed on the surfaces having the transferred surface pattern to induce their directed self-assembly. Cylinders of P2VP oriented normal to the surface are markedly aligned along the rubbing direction and used as templates to generate extremely uniform arrays of various metallic nanoparticles of gold, silver, and platinum over a large area.

Optical absorption and visible luminescence aspects including visible emission decay times have been examined for six Sm3+ (1 mol%)-doped B2O3-rich glasses comprising single and mixed alkali oxides which were synthesized via melting-and-quenching approach. Upon intense λexci. = 409 nm, fluorescence spectra displayed four bands peaked at 562 nm, 598 nm, 645 nm, and 706 nm owing to 4G5/2 upper level to 6H5/2, 6H7/2, 6H9/2, and 6H11/2 lower levels transitions respectively. Among identified emissions, orange fluorescence (598 nm) is found to be strong in all samples. Moreover Sm3+: Li ions having sample exhibits the dominant visible emissions band intensity in all samples, so for this sample, Judd–Ofelt (J O) analysis was carried out to calculate J O parameters Ωt (t = 2, 4, 6), and from them, radiative transition probabilities, branching ratios (calculated and experimental), and radiative lifetimes of Sm3+: 4G5/2 level to distinct lower energy states were derived utilizing absorption and emission spectra. CIE (Commission Internationale de l′eclairage) coordinates, correlated color temperature (CCT), color purity, color rendering index, and luminous efficiency of radiation were determined from visible luminescence spectra of all studied glasses, and obtained CIE coordinates and CCT values lie in the reddish-orange light region of CIE diagram, indicating their potential for orange LEDs (light-emitting diodes) application. Here derived CCT values are lower than the typical warm light sources CCT limit (

This paper presents an efficient and eco-friendly soil stabilization method for binding the soil particles of rammed earth walls. The method uses a combination of a water-soluble acrylic acid–acrylic amide copolymer and an epoxy system containing a hardener. The results revealed that the unconfined compressive strength (UCS) of soil stabilized with the mixture of the copolymer and epoxy system was five times higher than that of soil treated with water and three times higher than that of stabilized soil (SS) with only the copolymer. The roles of the copolymer and epoxy system in UCS enhancement were determined based on morphology and apparent density (AD) and elucidated using proposed models. The soil stabilized with the copolymer and epoxy system exhibited the lowest AD and highest UCS. Further, its unique web-like morphology is consistent with the formation of an interpenetrating polymer network (IPN). The carboxylic and amide groups in the copolymer contribute to the formation of the IPN through interactions with the epoxy and amine groups of the hardener. The surface hydroxyl groups in the soil promote the coating of the polymer layer on the soil surface and the inter-particle cohesion, resulting in the formation of larger compacted lumps with a decreased AD and increased UCS. The hydrophilic copolymer acts as a stabilizer and plasticizer. The results confirmed that the epoxy system and copolymer significantly increased the UCS by forming an IPN. Thus, this study provides an efficient and eco-friendly water-soluble copolymer and epoxy system for enhancing the UCS of soil.

The major focus of this work is the design and optimization of the preparation conditions of binary titanium dioxide-zinc oxide (TiO2-ZnO) composite using response surface methodology (RSM). Calcination temperature and ZnO weight percent (%) with respect to TiO2 were chosen as the key parameters for optimizing the preparation conditions. The evaluation of photocatalytic nitrogen oxides (NOx) removal efficiency was selected for modeling the RSM. Thirteen factorial design runs were first generated with one replicate and 5 center points in order to perform all the experiments. The experimental results on NOx removal efficiency for the composites calcined at 747, 602, and 558 °C containing 5.48%, 3.48%, and 2.1% of ZnO with respect to the weight of TiO2, designated as MaxT(Z%), MedT(Z%) and MinT(Z%) respectively, agree well with RSM predictions. The response coefficient difference between experimental and RSM results of MaxT(Z%), MedT(Z%), and MinT(Z%) were approximately 0.019, 0.044, and 0.11, respectively. The microstructural and optical properties as well the surface composition of MaxT(Z%), MedT(Z%), and MinT(Z%) were evaluated by X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), and X-ray photoelectron spectroscopy (XPS), respectively. The results from the photodecomposition of NOx gas under illuminated UV-light confirmed that the TiO2-ZnO prepared with a 2.1 wt% of ZnO and calcined at 558 °C witnessed the best photocatalytic activity and the reasons for the excellent performance are corroborated with XRD, XPS, and DRS results. This study provides a simple and systematic approach for the optimization and modeling of the binary composite preparation for achieving enhanced photoactivity.

In this work, we report the enhanced 2080 nm emission from Ho3+ and 1999 nm emission of Tm3+ both via Er3+ sensitization in Gd3Ga5O12 (abbr. as GGG) crystals excited with 965 nm laser diode (LD) respectively. The underlying mechanisms were analyzed based on the measurements of absorption and emission spectra as well as fluorescence decay curves. Optical parameters including absorption and emission cross-sections, as well as fluorescence decay times are evaluated and compared. Owing to the co-doped sensitizer ion Er3+, a strong absorption near 965 nm plays an important role in the enhanced 2080 nm emission by transferring pump energy to Ho3+: 5I7 level in Er, Ho: GGG crystal, similarly, transferring energy from Er3+ to Tm3+: 3F4 level is conducive to improve 1999 nm emission in Er, Tm: GGG crystal. The above results demonstrate that the introduction of Er3+ into Ho3+ or Tm3+ activated materials offers a promising approach to obtain an enhanced 1.9–2.1 μm laser, which could operate upon 965 nm LD pumping, and the efficient energy transfer plays a key role in rare-earth ions doped luminescent materials.

Transforming CO2 into solar fuel using renewable solar energy and a catalyst is an effective approach that simultaneously addresses energy scarcity and climate deterioration. Therefore, it is necessary, albeit challenging, to design a catalyst that works effectively for this purpose. Herein, we have rationally developed a hybrid catalyst composed of highly-configured TiO2 hollow spheres (TOH) and N-doped carbon dots (CD), referred to as CD/TOH, and use this hybrid as a catalyst for photocatalytic CO2 reduction to produce CH4 under simulated sunlight. The electron microscopy results revealed that the CD/TOH hybrid possesses a porous hollow sphere structure uniformly adorned with N-doped carbon dots. Moreover, the CD/TOH hybrid demonstrates many beneficial properties for CO2 photoreduction reactions, including a large surface area, effective light-harvesting capability, high CO2 adsorption, and, most importantly, significantly enhanced separation of photoexcited charges. Consequently, the CD/TOH containing 2 wt% CD achieves an optimum CH4 formation rate of 26.8 μmol h−1 g−1, corresponding to 98% CH4 selectivity against competitive H2 production. Further, the hybrid also demonstrated stable CO2 reduction activity during consecutive test runs. Thus, the insights gained from this study may aid in the development of effective catalysts for CO2 photoreduction.