Low Photon Research Articles

Green approach to synthesis polymer composites based on chitosan with desired linear and non-linear optical characteristics

The current study used sustainable and green approaches to convey polymer composites with desired optical properties. The extracted green tea dye (GTD) enriched with ligands was used to synthesize zinc metal complexes. Green chitosan biopolymer incorporated with green synthesized metal complex using casting technique was used to deliver polymer composites with improved optical properties. The FTIR-ATR was used to identify the functional groups of the GTD, pure CS, and functional groups surrounding the synthesized zinc metal complex. Distinguished ATR bands were observed in green tea dye spectra, such as OH, C = O, and NH functional groups ascribed to various polyphenols. The ATR bands of the zinc metal complex compared to GDT established that GDT is crucial to capturing zinc cations and producing the Zn2+-metal complex. The broadness of the bands observed in CS-based composites inserted with the Zn2+- metal complex confirms strong interaction among the components of polymer composites. The XRD achievements confirm that CS films with different Zn2+- metal complex concentrations transferred to an amorphous composite. The XRD pattern of composite films establishes that the zinc metal complex scarified the crystalline phases of chitosan. Linear optical properties such as absorption, refractive index (n), and optical dielectric parameters were improved. The absorption edge of the composite’s films shifted to lower photon energies. Various models were used to determine the optical band gap. The band gap drops from when chitosan is loaded with a 36% Zn2+-metal complex. The Spitzer-Fan method is used to get the dielectric constant, and the Drude Lorentz oscillator model was used to calculate vital optical parameters, including N/m*, τ, and µopt. The W-D single oscillator model was used to determine the Eo and Ed parameters. The values of optical moments (M−1 and M−3) were calculated with the help of the W-D model. The oscillator’s strength () and wavelength () were determined via the Sellmeier model using the linear refractive index. The first-order nonlinear ( ), second-order non-linear () and third-order nonlinear optical susceptibility () were determined for all the films.

Understanding the Variations of Optical Bandgap in AZO Nanostructured Thin Films: Analysis of Possible Influences

Aluminum doped zinc oxide (AZO) thin films with varying thicknesses are fabricated using radio frequency (RF) sputtering combined with substrate rotation. The films display distinct nanocolumnar structures characterized by a hexagonal ZnO phase and a noticeable shift of the primary diffraction peak to lower 2θ angles. Lattice parameters a and c are used to evaluate residual stress and structural relaxation, both of which vary with increasing film thickness. Despite these structural changes, the films consistently maintain an average optical transmittance close to 85% in the range of 400–900 nm. The absorption edge and bandgap energy shift toward lower photon energies, decreasing from 3.51 to 3.38 eV as the thickness increases. The interplay between residual stress, structural relaxation, and bandgap energy is analyzed, offering insights into the complex dynamics influencing AZO thin‐film fabrication and the potential effects of quantum confinement. Lastly, the findings are compared with recent studies on ZnO thin films.

Utility of photon-counting detectors for MV-kV dual-energy computed tomography imaging.

High soft-tissue contrast imaging is essential for effective radiotherapy treatment. This could potentially be realized using both megavoltage and kilovoltage x-ray sources available on some therapy treatment systems to perform "MV-kV" dual-energy (DE) computed tomography (CT). However, noisy megavoltage images obtained with existing energy-integrating detectors (EIDs) are a limiting factor for clinical translation. We explore the potential for non-spectral photon-counting detectors (PCDs) to improve MV-kV image quality simply by equally weighting all MV photons rather than up-weighting the less informative, lower contrast high-energy photons as in an EID. Three computational methods were applied to compare non-spectral PCDs with EIDs in MV-kV DE imaging. A single-line integral estimation theory approach was used to calculate the basis material signal-to-noise ratio (SNR) of tissue (1 to 50cm) and bone (0.1 to 10cm). CT images of a tissue cylinder with seven bone inserts (densities 1.0 to ) were simulated to assess material decomposition accuracy. Multiple noisy simulations of an anthropomorphic phantom were performed to generate pixel-by-pixel noise profiles. PCDs yielded a 15% to 45% improvement in single-line integral SNR for both materials. In CT simulations, similar material decomposition accuracy was achieved, with both EIDs and PCDs slightly underestimating bone density. However, PCDs yield a higher contrast-to-noise ratio and more uniform noise texture than EIDs in virtual monoenergetic images. We demonstrate the potential for improved MV-kV DE CT imaging using non-spectral PCDs and quantify the degree of improvement in a range of object compositions. This work motivates the experimental assessment of PCDs for megavoltage imaging and the potential clinical translation of PCDs to radiotherapy imaging.

Effect of lead oxide addition on gamma radiation shielding properties of newly developed geopolymers: theoretical and simulation studies

The efficiency of geopolymers as an effective immobilization system for various hazardous waste materials can be enhanced by adding PbO to improve its radiation shielding characteristics. In this study, the impact of PbO addition on the shielding properties of geopolymer composites was examined to evaluate the gamma radiation shielding characteristics of the geopolymer using FLUKA and XCOM computer programs. The results showed that adding 10% and 20% lead oxide significantly improved the shielding properties of the investigated geopolymer, mostly at lower photon energies. The higher values of MAC of 59.66728 cm2/g at 0.015 MeV, and 0.03916 cm2/g at 15 MeV for the investigated geopolymers suggest that these materials have improved radiation shielding at lower and intermediate energies due to higher photoelectric absorption and Compton scattering. The findings of this study provided valuable insights for designing high-performance radiation protection in medical imaging facilities, nuclear power plants, industrial radiography and other special radiation installations. Therefore, GEO doped with 20PbO should be deployed to fortify these facilities against ionizing radiations.

Study on Pressure-Induced Band Gap Modulation and Physical Properties of Direct Band Gap Ca3NX3 (X = Cl, Br) for Optoelectronic and Thermoelectric Applications

Utilizing density functional theory, we have comprehensively analyzed the structural, electronic, mechanical, transport, and thermodynamic properties of Ca3NCl3 and Ca3NBr3 photovoltaic materials. Furthermore, we investigated the impact of pressures ranging from 0 to 80 GPa and observed that the applied pressure decreases the atomic distances, resulting in significant changes in the physical properties of both materials. We employed GGA-PBE and TB-mBJ functionals to calculate the band structures and density of states, confirming their semiconducting nature. At 0 GPa, both compounds initially display a direct bandgap (Γ-Γ) of 1.5 eV for Ca3NCl3 and 1.26 eV for Ca3NBr3 based on GGA-PBE calculations. In contrast, the TB-mBJ calculations show an increase in the bandgap to 2.25 eV for Ca3NCl3 and 1.84 eV for Ca3NBr3, respectively. When a pressure of 80 GPa was applied, the direct bandgap of Ca3NCl3 and Ca3NBr3 decreased to 0.23 eV and 0.12 eV with GGA-PBE, and to 0.92 eV and 0.74 eV with TB-mBJ, respectively. It was also observed that the effective mass decreases under applied pressure, making these materials promising candidates for solar cell applications. The mechanical stability of both perovskites was maintained up to 80 GPa. Poisson's ratio and Pugh's ratio indicate that both compounds are brittle at 0 GPa but tend to become more ductile under applied stress. The optical properties reveal that pressure alters the dielectric function, absorption spectra, and optical conductivity, causing a red shift from higher to lower photon energies. Several thermodynamic properties, including heat capacity, Debye temperature, thermal expansion coefficient, and entropy, have been calculated, with their dependencies on temperature and pressure illustrated. Finally, the thermoelectric response of these materials is evaluated by examining how various transport parameters - such as the Seebeck coefficient, electrical and thermal conductivity, and power factor - depend on the temperature.

DFT based analysis of pressure driven mechanical, opto-electronic, and thermoelectric properties in lead-free InGeX3 (X = Cl, Br) perovskites for solar energy applications

Lead halide perovskites have distinct physiochemical properties and demonstrate remarkable power conversion efficiency. We used density functional theory to investigate the electrical, optical, structural, and elastic features of non-toxic InGeCl3 and InGeBr3 halide perovskite compounds at different hydrostatic pressures, from 0 to 8 GPa. InGeCl3 and InGeBr3 halide perovskite exhibit noteworthy changes in their electronic and optical properties under different pressure conditions. When the pressure is 0 GPa, the direct bandgap for InGeCl3 is 0.886 eV, and for InGeBr3 it is 0.536 eV. This gap decreases as the pressure rises. Specifically, InGeBr3 exhibits conducting properties at 3 GPa due to its larger bromine atoms, whereas InGeCl3 requires a higher pressure of 6 GPa to achieve similar conductivity. This type of nature suggests that larger halogen atoms reduce the bandgap more effectively under pressure. As the pressure increases, the behavior of the lattice constant and unit cell volume decreases constantly, from 5.257 and 145.267 Å3 for InGeCl3 to 5.509 and 167.168 Å3 for InGeBr3 at 0 GPa for both compounds. When subjected to pressure, the bonds between In-X and Ge-X atoms experience compression, leading to a decrease in surface area and an enhancement in mechanical strength. Overall, the compounds exhibit characteristics of semiconductors, as evidenced by evaluations of their electrical properties. As pressure increases, the bandgap decreases linearly, narrowing until it aligns with the Fermi level, leading to a transition toward a metallic state. In addition, the pressure induces a rise in the electrical density of states around the Fermi level by displacing valence band electrons in an upward direction. As pressure increases, the electron density peak shifts to lower photon energy values. Notably, InGeCl3 exhibits a more pronounced shift in this peak compared to InGeBr3, indicating greater sensitivity to pressure. In terms of optical properties, both compounds demonstrate significant absorption coefficients in the visible region, suggesting their potential suitability for photovoltaic applications. The dielectric constant, absorption, and reflectivity values all increase gradually as pressure increases. The absorption spectra shift toward longer wavelengths. Furthermore, the mechanical properties analysis reveals that all InGeX3 compounds are mechanically stable up to 8 GPa pressure.

Unsupervised Denoising in Spectral CT: Multi-Dimensional U-Net for Energy Channel Regularisation

Spectral Computed Tomography (CT) is a versatile imaging technique widely utilized in industry, medicine, and scientific research. This technique allows us to observe the energy-dependent X-ray attenuation throughout an object by using Photon Counting Detector (PCD) technology. However, a major drawback of spectral CT is the increase in noise due to a lower achievable photon count when using more energy channels. This challenge often complicates quantitative material identification, which is a major application of the technology. In this study, we investigate the Noise2Inverse image denoising approach for noise removal in spectral computed tomography. Our unsupervised deep learning-based model uses a multi-dimensional U-Net paired with a block-based training approach modified for additional energy-channel regularization. We conducted experiments using two simulated spectral CT phantoms, each with a unique shape and material composition, and a real scan of a biological sample containing a characteristic K-edge. orangeMeasuring the peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM) for the simulated data and the contrast-to-noise ratio (CNR) for the real-world data, our approach not only outperforms previously used methods—namely the unsupervised Low2High method and the total variation-constrained iterative reconstruction method—but also does not require complex parameter tuning.

Predictions on new Cu-based ABO3 (A=Cu and B=Lu, Y) oxide-perovskite for energy storage and optoelectronic applications: A DFT study

Cu-based novel oxide-perovskite ABO3(A = Cu and B=Lu, Y) compounds have been investigated for their physical properties using the Generalized Gradient Approximation and Revised-Perdew-Burke-Ernzerhof (GGA-RPBE) exchanging correlation-functional within the density functional theory (DFT). The calculations show that both compounds comprise a cubic structure with the space group of Pm3m. The calculations also indicate that the results we have discovered represent unique compounds. Formation enthalpy computations have been used to assess the overall structural stability of both compounds. The density of states and band structure graphs for both perovskite compounds provide strong evidence of their semiconducting behavior. In-depth research is also done on optical properties such as the refractive index, extinction coefficient, absorption, reflectivity, electrical conductivity, and the energy loss function. At high-energy photons, both compounds CuLuO3 and CuYO3 show outstanding conductivity and absorption. While, at lower incident photon energy intervals, they both exhibit transparency. Based on our electronic and optical properties investigations, we have found that CuLuO3 and CuYO3 are potential candidates for use in high-energy UV, and optoelectronic technologies.

Anion-Driven Bandgap Tuning of AgIn(SxSe1-x)2 Quantum Dots.

Accurate tuning of the electronic and photophysical properties of quantum dots is required to maximize the light conversion efficiencies in semiconductor-assisted processes. Herein, we report a facile synthetic procedure for AgIn(SxSe1-x)2 quantum dots with S content (x) ranging from 1 to 0. This simple approach allowed us to tune the bandgap (2.6-1.9 eV) and extend the absorption of AgIn(SxSe1-x)2 quantum dots to lower photon energies (near-IR) while maintaining a small QD size (∼5 nm). Ultraviolet spectroscopy studies revealed that the change in the bandgap is modulated by the electronic shifts in both the valence band and the conduction band positions. The negative overall charge of the as-synthesized quantum dots enabled us to make films of quantum dots on mesoscopic TiO2. Excited state studies of the AgIn(SxSe1-x)2 quantum dot films demonstrated a fast charge injection to TiO2, and the electron transfer rate constant was found to be 1.5-3.5 × 1011 s-1. The results of this work present AgIn(SxSe1-x)2 quantum dots synthesized by the one-step method as a potential candidate for designing light-harvesting assemblies.

Nickel oxide nanoparticles embedded in polymer-matrix nanocomposite prepared by nanosecond laser ablation method for optoelectronic applications

The polymeric PVA structure embedded with nickel oxide nanoparticles (NiO NPs) was synthesized using nanosecond pulsed laser ablation in liquid media technique for optoelectronic applications. A comprehensive investigation was conducted on the optical and electrical characteristics of the fabricated films to demonstrate the proficiency of the proposed nanocomposite film in that particular domain. Different weights of NiO nanoparticles were generated by embedding them in PVA film using different ablation durations. It was shown that as the concentration of NiO embedded in PVA increased in correlation with the ablation period, the absorption peak changed to a longer wavelength, and the absorption edge of PVA changed towards lower photon energy with a reduction in the band gap density. Followed by the increase in disorder degree through the addition of NiO NPs, while an average value of the dispersion energy is identical, and the nonlinear parameters (χ(3) and n2) increase. Also, the results emphsies that the dielectric characteristics were affected as the concentration of NiO NPs increased due to the rise in the density of states, which resulted in the generation of polarization. Due to the creation of the charge transfer complex, the optical conductivity of the produced nanocomposites rises as the concentration of NiO NPs increases. Therefore, the optical and electrical characteristics of PVA are significantly affected by the incorporation of NiO nanocomposites.

Ionic Fragmentation of the Halothane Molecule Induced by EUV and Soft X-ray Radiation.

EUV and soft X-ray-induced photofragmentation of the halothane (CF3CHBrCl) molecule has been investigated using time-of-flight mass spectrometry in the coincidence mode (PEPICO) covering the valence region and vicinity of the bromine 3d, chlorine 2p, and carbon 1s edges. Total and partial ion yields have been recorded as a function of photon energy. At lower photon energies, the heavier singly charged molecular fragments predominate in the mass spectra. On the other hand, there is a strong tendency to the atomization of the molecule at higher photon energies. Despite the different chemical environments experienced by the two carbon atoms, weak site-specific fragmentation is observed. In addition, ab initio quantum mechanical calculations at the MP2 level and a series of computations with multiconfigurational self-consistent field have been performed to describe the inner-shell states.

The effect of pressure on the structural, optoelectronic and mechanical conduct of the XZnF3 (X= Na, K and Rb) perovskite: First-principles study

By using the DFT approach within the generalized gradient approximation (GGA) adopted in the Wien2k code, the effects of pressure on the structural, electrical and optical characteristics of XZnF3 ([Formula: see text] Na, K and Rb) halide perovskites have been investigated. In the present paper, the unit cell structures of XZnF3 ([Formula: see text] Na, K and Rb) have been optimized. Within the present approximation, the analysis showed indirect bandgaps of those compounds. At 0[Formula: see text]GPa, the density of states (DOS) besides band structures predicted the bandgaps of (2.80, 3.84 and 4.22[Formula: see text]eV) connected to (NaZnF3, KZnF3 and RbZnF[Formula: see text], respectively. These indirect bandgaps increase from (0 to 20[Formula: see text]GPa) with hydrostatic pressure. Regarding the optical properties, the imaginary part [Formula: see text] of the dielectric function, the absorption [Formula: see text], the reflectivity [Formula: see text] and the refractive index [Formula: see text] are determined. The light absorption at the surface begins at critical points corresponding to the threshold energy, their values of (5.00, 5.20 and 5.30[Formula: see text]eV at 0[Formula: see text]GPa) and (5.90, 6.30 and 6.50[Formula: see text]eV at 20[Formula: see text]GPa) related to NaZnF3, KZnF3 and RbZnF3, respectively. The pressure induced in XZnF3 ([Formula: see text] Na, K and Rb) reduces absorption intensity to a remarkable extent, both in the visible and ultraviolet range and the intensity of the reflectivity spectra decreases with increasing pressure. When there is no induced pressure, optical conductivity starts out with lower photon energies and increases as pressure builds up, reaching greater photon energies at pressures of up to 20[Formula: see text]GPa. The mechanical stability of the material studied is verified using the Born stability criteria, the values obtained for the elastic constants verify the stability conditions of XZnF[Formula: see text] Na, K and Rb), improving with applied pressure 0 up to 20[Formula: see text]GPa. NaZnF3 and KZnF3 have slightly higher ductility than RbZnF3 at 0[Formula: see text]GPa, and KZnF3 has a slightly higher ductility than NaZnF3 at 0[Formula: see text]GPa, and higher than RbZnF3 at 20[Formula: see text]GPa. Also, the mechanical stability is verified using the Born stability criteria, where the elastic constants verify the stability conditions. The Cauchy pressure value of XZnF3 ([Formula: see text] Na, K and Rb) perovskite under all the pressures studied is positive, indicating that the ductile nature of perovskite improves and increases with increasing pressure.

Unraveling lead-free Fr-based perovskites FrQCl3 (Q = Ca, Sr) and their pressure induced physical properties: DFT analysis for advancing optoelectronic performance

A comprehensive study of structural, electronic, elastic, and optical properties of the cubic FrQCl3 (Q = Ca, Sr) perovskite under pressure 0 − 105 GPa has been considered. Interestingly, FrCaCl3 experiences a shift from an indirect to a direct bandgap material at 12 GPa, while FrSrCl3 undergoes the same shift at 10 GPa, rendering these materials more advantageous for application in optoelectronic devices. As pressure rises, the electronic density of states increases near the Fermi level by shifting valence band electrons upward. This leads to a reduction in the bandgap and a shift of the bandgap from the ultraviolet to the visible region. The examination of mechanical properties indicates that FrQCl3 (Q = Ca, Sr) perovskite exhibits significant potential for uses requiring a combination of anisotropic, and ductile behavior. Optical property analysis reveals that with an increase in hydrostatic pressure, dielectric constant's peak of both material shift towards lower photon energy area.

Ti‐Doped ZnO Thin Films‐Based Transparent Photovoltaic for High‐Performance Broadband and Wide‐Field‐of‐View Photocommunication Window

Transparent photovoltaics (TPVs) are crucial for developing next‐generation see‐through electronics. However, TPV devices (TPVDs) require wide‐bandgap materials that are typically only responsive to short wavelength (ultraviolet, UV) lights rather than visible lights. Is it possible to improve the TPV performance by harvesting the longer wavelength lights without degradation of transparency? It may be satisfied with the function of intermediate energy states, which can utilize the lower photon energy (longer wavelength light) by a two‐step transition. To achieve this, co‐sputtered Ti‐doped ZnO (Ti:ZnO) film‐based high‐performance TPVDs have been developed. Density functional theory analysis revealed the formation of intermediate energy states due to the hybridization of O 2p and Ti 3d orbitals in the Ti:ZnO system. The Ti:ZnO‐based TPVDs show 65% average visible transparency with a power production value of 655 μW cm−2. These devices exhibit good photodetection behavior under UV to visible illuminations with high responsivity and detectivity values of 1.85 A W−1 and 2.5 × 1013 Jones, respectively. Finally, a high‐performance UV to visible broadband and wide‐field‐of‐view photocommunication system is designed based on the TPVDs to generate the fast Morse code signal. Therefore, Ti doping in ZnO provides a good way to improve the device's functionality for futuristic applications.

Fourier-transform infrared spectroscopy with undetected photons from high-gain spontaneous parametric down-conversion

Fourier-transform infrared spectroscopy (FTIR) is an indispensable analytical method that allows label-free identification of substances via fundamental molecular vibrations. However, traditional FTIR spectrometers require mid-infrared (MIR) elements, including low-efficiency MIR photodetectors. SU(1,1) interferometry has previously enabled FTIR with undetected MIR photons via spontaneous parametric down-conversion in the low-parametric-gain regime, where the number of photons per mode is much less than one and sensitive photodetectors are needed. In this work, we develop a high-parametric-gain SU(1,1) interferometer for MIR-range FTIR with undetected photons. Using our method, we demonstrate three major advantages: a high photon number at the interferometer output, a considerably lower photon number at the sample, and improved interference contrast. In addition, we broaden the spectral range of the interferometer by aperiodic poling in the gain medium. Exploiting the broadband SU(1,1) interferometer, we measure and evaluate the MIR absorption spectra of polymers in the 3-μm region.

Predominance of Yb3+ and Ce3+ on the AlTaBaBO: Yb and BaTiSbBPO: Ce glasses for effective photoluminescence and radiation shielding properties towards w-LED and γ-ray shielding applications

Alumino tantalum barium borate - 65B2O3 +10Al2O3 +5SrCO3 +5BaCO3 +14Li2CO3 +4Ta2O5 +1Yb2O3 (AlTaBaBO: Yb) and barium antimony borophosphate - 35P2O5 +35B2O3 +10TiO2 +5 KF +10Li2CO3 +4SbO3 +1CeO3 (BaTiSbBPO: Ce) glasses were prepared using melt – quenching technique. The structural property of as-prepared glass materials is investigated by powder X–ray diffraction to identify the amorphous nature of the materials. FTIR and FT-Raman spectroscopic analyses examined various functional groups of glasses. The linear optical behaviours were characterized using UV–visible spectroscopy, and besides the different linear optical parameters such as refractive index and optical bandgap, optical conductivity was estimated. Excitation and emission spectra of the harvested glasses were characterized using a Photoluminescence spectrophotometer. Rare earth – R.E (Yb3+ and Ce3+) doped both glasses have greater emission efficiency due to their 2F7/2 → 2F5/2 (951 nm) and 5d1 → 2F5/2, 2F7/2 (550 and 663 nm) electronic transitions, which shows that the as-prepared glass materials have their potential applications. Colour chromaticity (CIE) diagrams of the cultivated glasses were examined with colour co – ordinations x = 0.3054, y = 0.2881 for AlTaBaBO: Yb and x = 0.3874, y = 0.3436 for BaTiSbBPO: Ce and the obtained outcomes confirmed w-LED device fabrication. Moreover, the various γ– ray shielding parameters were analyzed theoretically using Phy-X software. The five (a, b, c, d, and Xk) parameters of the Geometric Progression (G-P) fitting scheme were used to determine the energy-related energy buildup factor (EBF) as well as energy absorption buildup factor (EABF) of glasses in terms of infiltration deepness up to 40 mfp. At lower photon energy, the AlTaBaBO: Yb and BaTiSbBPO: Ce glasses have the highest μ/ρ values of 4.47 × 105 cm2/g and 3.864 × 103 cm2/g, respectively. For AlTaBaBO: Yb and BaTiSbBPO: Ce glasses, the calculated mean free path (MFP) values at 15 MeV photon energy are 0.143 cm and 12.18 cm, respectively. The result of all findings reveals that the synthesised glasses are viable materials for the futuristic utilization of w-LED and neutron radiation shielding applications.

Analytical and fine Monte Carlo Kerma coefficients evaluation for a wide range photon energy relevant to some chemotherapy agents

Simultaneously combination of chemotherapy drugs and ionizing radiations has become a common treatment method for advanced cancers. Tumor irradiation in presence of chemotherapy drugs can affect deposited energy within tissue. Hence, to evaluate how chemotherapy drugs affect the absorbed dose within tissues during chemoradiotherapy, Kerma coefficient values for 26 anti-cancer agents were estimated for photon energies ranging from 1 keV to 20 MeV through analytical analysis and Monte Carlo (MC) simulation approaches.Estimation of Kerma coefficients through MC simulation relevant to different chemotherapy drugs was performed with MCNPX V.2.6.0 MC code. Besides, Kerma coefficient values were calculated using the reported mass energy absorption coefficients, as the theoretical method. Significant statistical test was also employed to evaluate the accordance of obtained Kerma coefficients by two considered methods.Simulation results were consistent with evaluated Kerma coefficients by analytical method which minimum and maximum mean relative differences are found for Bevacizumab and Methotrexate, respectively. Furthermore, a significant correlation is found with chemical composition of selected chemotherapy drugs at considered photon energy range. Fluorouracil showed the closest Kerma ratio to unity among the studied anti-cancer drugs. Kerma coefficient ratios for most of selected drugs were close to unity at higher energy regions (100 keV–20 MeV) while greater values were found at lower photon energies (below 100 keV).From the results, presence of these anti-cancer agents can impact Kerma coefficient and subsequently alter the absorbed dose within tissue during the cancer treatment with chemoradiotherapy technique.

Optical bistability at lower photon number via photon and phonon interaction in the presence of Kerr nonlinearity

Optical bistability is theoretically analyzed in a hybrid optomechanical system consisting of an optical cavity including a Kerr medium and an optomechanical cavity coupled by direct tunnel coupling. The dynamics of the system is described by Heisenberg–Langevin equations. It is numerically shown that there is a critical value of the Kerr coefficient to observe the bistability of the intracavity intensity for a given coupling rate, and the changing of the Kerr coefficient will lead to the changing of the critical point to observe the bistability as well. In addition, the first critical value to observe bistability becomes larger with the increasing coupling rate between the two cavities. It is also demonstrated that the pump beam required to realize the bistable behavior in the blue sideband regime is significantly smaller than that in the red sideband regime. And the mean intracavity photon number is relatively larger in the red sideband case than that in the blue sideband case. It is remarkable to observe that the mean intracavity photon numbers in both cavities are much lower than that in ordinary situations.

Advancing mechanical durability and radiation shielding properties in Silicon dioxide (SiO2) glasses through various incorporations: A comparative analysis

Silicon dioxide (SiO2) glasses, known for their high thermal stability, excellent optical transparency, and substantial mechanical strength, are crucial in numerous technological applications, including radiation shielding. This research explores the impact of compositional variations in SiO2-based glasses on their mechanical and radiation shielding properties, particularly focusing on the inclusion of heavy metal oxides (HMO) and rare earth elements (REE) like neodymium (Nd). Through the systematic investigation of fifteen distinct glass samples with varying concentrations of specific oxides and elements, we investigate the compositional changes and their influence on physical properties and their effectiveness in attenuating radiation. Our findings demonstrate that the incorporation of Nd significantly enhances the glass's radiation shielding capabilities. Glasses doped with Nd exhibited higher effective atomic numbers and electron densities, which translate to superior attenuation characteristics at lower photon energies. This is highlighted by the exceptional performance of the 20Nd sample, showing the lowest exposure build-up factors (EBF) at 10 mean free paths (mfp), indicating its potential as a premier candidate for shielding applications against various energy levels of radiation. Moreover, the variation in the Elastic Modulus of the glass samples underscores the significant impact of the glass matrix composition on its mechanical properties, suggesting a delicate balance between network formers and modifiers in determining the glass properties. It can be concluded that the neodymium-doped SiO2-based glasses may be considered as targeted compositions in fine-tuning material properties to meet specific application requirements. As the demand for efficient radiation shielding materials grows across medical, industrial, and space exploration sectors, our findings provide a solid foundation for the development of new glass formulations tailored for enhanced mechanical properties and superior radiation protection levels.

Synthesis and characterization of FMWCNTs/ZnO doped PVDF nanocomposites for enhanced mechanical, dielectric, and radiation shielding properties

This study investigates the enhancement of radiation shielding properties of polyvinylidene fluoride (PVDF) through the incorporation of functionalized multi-walled carbon nanotubes (FMWCNTs) and zinc oxide nanoparticles (ZnONPs), aiming to develop a lightweight, effective, and environmentally friendly shielding material. PVDF-based nanocomposites with varying concentrations of FMWCNTs@ZnO (0.0, 0.5, 1.0, 1.5, and 3.0 wt%) were synthesized using a solution casting method. Morphological analysis via high-resolution transmission electron microscopy (HRTEM) and field emission scanning electron microscopy (FESEM) confirmed the uniform dispersion of FMWCNTs@ZnO within the PVDF matrix. X-ray diffraction (XRD) studies revealed an increase in the β-phase crystallinity of PVDF at 1 wt% FMWCNTs@ZnO concentration, with a notable peak shift indicating enhanced polar group development. Vickers microhardness tests showed a significant improvement, with hardness values increasing from 342.5 kg/mm2 for pure PVDF to 391.2 kg/mm2 for nanocomposites containing 3 % FMWCNTs@ZnO. Dielectric analyses demonstrated increased permittivity and a dynamic relaxation behavior indicative of improved charge carrier density and interfacial polarization. Gamma shielding efficiency, assessed through linear attenuation coefficients (GLAC) and mass attenuation coefficients (GMAC), exhibited superior performance at lower photon energies (80 keV), with the highest GLAC and GMAC values observed for the 3 wt% FMWCNTs@ZnO doped samples. These findings underscore the potential of FMWCNTs@ZnO doped PVDF nanocomposites as promising materials for radiation shielding applications, offering a synergistic approach to enhancing mechanical, dielectric, and protective properties against ionizing radiation.