Analytical Modelling and Simulation of Highly Sensitive n- RADFET Dosimeter

In the present paper, we have developed a model of a n-RADFET dosimeter device. Moreover, the study has addressed the effects of ionizing radiation on the surface potential and threshold voltage characteristics of the device. In addition, a detailed simulation analysis of the device has been conducted to obtain some further results. The study indicated that high sensitivity can be obtained for RADFET using n-MOSFET device. The results are expected to benefit in establishing the effectiveness of n-RADFET device as a dosimeter

Wire width and density dependence of the crossover in the peak of the static structure factor from 2kF2k_\text{F} →\rightarrow 4kF4k_\text{F} in one-dimensional paramagnetic electron gases

We use the variational quantum Monte Carlo (VMC) method to study the wire width ($b$) and electron density ($r_\text{s}$) dependences of the ground-state properties of quasi-one-dimensional paramagnetic electron fluids. The onset of a quasi-Wigner crystal phase is known to depend on electron density, and the crossover occurs in the low density regime. We study the effect of wire width on the crossover of the dominant peak in the static structure factor from $k=2k_\text{F}$ to $k=4k_\text{F}$. It is found that for a fixed electron density, in the charge structure factor the crossover from the dominant peak occurring at $2k_\text{F}$ to $4k_\text{F}$ occurs as the wire width decreases. Our study suggests that the crossover is due to interplay of both $r_\text{s}$ and $b<r_\text{s}$. The finite wire width correlation effect is reflected in the peak height of the charge and spin structure factors. We fit the dominant peaks of the charge and spin structure factors assuming fit functions based on our finite wire width theory and clues from bosonization, resulting in a good fit of the VMC data. The pronounced peaks in the charge and spin structure factors at $4 k_\text{F}$ and $2 k_\text{F}$, respectively, indicate the complete decoupling of the charge and spin degrees of freedom. Furthermore, the wire width dependence of the electron correlation energy and the Tomonaga-Luttinger parameter $K_{\rho}$ is found to be significant

Electron correlation and confinement effects in quasi-one-dimensional quantum wires at high density

We study the ground-state properties of ferromagnetic quasi-one-dimensional quantum wires using the quantum Monte Carlo (QMC) method for various wire widths b and density parameters rs. The correlation energy, pair-correlation function, static structure factor, and momentum density are calculated at high density. It is observed that the peak in the static structure factor at k=2kF grows as the wire width decreases. We obtain the Tomonaga-Luttinger liquid parameter Kρ from the momentum density. It is found that Kρ increases by about 10% between wire widths b=0.01 and b=0.5. We also obtain ground-state properties of finite-thickness wires theoretically using the first-order random phase approximation (RPA) with exchange and self-energy contributions, which is exact in the high-density limit. Analytical expressions for the static structure factor and correlation energy are derived for b≪rs<1. It is found that the correlation energy varies as b2 for b≪rs from its value for an infinitely thin wire. It is observed that the correlation energy depends significantly on the wire model used (harmonic versus cylindrical confinement). The first-order RPA expressions for the structure factor, pair-correlation function, and correlation energy are numerically evaluated for several values of b and rs≤1. These are compared with the QMC results in the range of applicability of the theory

Observation of γγ → ττ in proton-proton collisions and limits on the anomalous electromagnetic moments of the τ lepton

The production of a pair of τ leptons via photon–photon fusion, γγ → ττ, is observed for the f irst time in proton–proton collisions, with a significance of 5.3 standard deviations. This observation is based on a data set recorded with the CMS detector at the LHC at a center-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 138 fb−1. Events with a pair of τ leptons produced via photon–photon fusion are selected by requiring them to be back-to-back in the azimuthal direction and to have a minimum number of charged hadrons associated with their production vertex. The τ leptons are reconstructed in their leptonic and hadronic decay modes. The measured fiducial cross section of γγ → ττ is σfid obs = 12.4+3.8 −3.1 fb. Constraints are set on the contributions to the anomalous magnetic moment (aτ) and electric dipole moments (dτ) of the τ lepton originating from potential effects of new physics on the γττ vertex: aτ = 0.0009+0.0032 −0.0031 and |dτ| &lt; 2.9×10−17ecm (95% confidence level), consistent with the standard model

Formation of singlet oxygen by decomposition of protein hydroperoxide in photosystem II.

Singlet oxygen (1O2) is formed by triplet-triplet energy transfer from triplet chlorophyll to O2 via Type II photosensitization reaction in photosystem II (PSII). Formation of triplet chlorophyll is associated with the change in spin state of the excited electron and recombination of triplet radical pair in the PSII antenna complex and reaction center, respectively. Here, we have provided evidence for the formation of 1O2 by decomposition of protein hydroperoxide in PSII membranes deprived of Mn4O5Ca complex. Protein hydroperoxide is formed by protein oxidation initiated by highly oxidizing chlorophyll cation radical and hydroxyl radical formed by Type I photosensitization reaction. Under highly oxidizing conditions, protein hydroperoxide is oxidized to protein peroxyl radical which either cyclizes to dioxetane or recombines with another protein peroxyl radical to tetroxide. These highly unstable intermediates decompose to triplet carbonyls which transfer energy to O2 forming 1O2. Data presented in this study show for the first time that 1O2 is formed by decomposition of protein hydroperoxide in PSII membranes deprived of Mn4O5Ca complex

Recent advances in bulk-heterojunction solar cells: a review

Because of the challenges brought by our continuous reliance on fossil fuels, there has been a rush in the creation of numerous types of solar cells in recent years. The functionality of organic solar cells with a bulk heterojunction structure has substantially increased in recent years. However, further advancements are required for large-scale engineering of this technology and precision device production. The fundamental of BHJ, working mechanism, characteristics, architecture and recent breakthroughs of this technology for solar cells, photocatalytic applications and photodetectors are highlighted in this article. The approaches to advance the stability, including the control over morphology, absorption coefficient, charge carrier mobility and lifetime, exciton lifetime, exciton binding energy and dissociation are also discussed in this article. Lastly, there are recommendations for needed improvements as well as future research areas in the realm of bulk-heterojunction solar cells. We expect this review could provide enriched information to better understand the BHJ structure and recent progress in this field