goh boon tong

The influence of nuclear rotation on the decay half-lives of superheavy nuclei within the range 98≤ Z≤ 120 is investigated using the axially deformed relativistic Hartree-Bogoliubov theory in the continuum (DRHBc) with the PC-PK1 parameter set. The deduced DRHBc decay energies (with and without the rotation effect) are compared with those calculated from the macroscopic-microscopic WS4 and the available experimental binding energies. Six semi-empirical formulae, such as the Viola-Seaborg formula (VSS), the modified Brown formula (mB1), the semi-empirical relationship based on fission theory (SemFIS2), the Royer formula (R), the Wang formula (Wang) and the modified YQZR formula (MYQZR) are employed to estimate the half-lives of α decay. Among these formulae, the half-live predictions of SemFIS2 are found to gradually deviate from the systematic trend beyond N d= 184, showing that the …

The search for high-performance catalysts to improve the catalytic activity for an oxygen reduction reaction (ORR) is crucial for developing a proton exchange membrane fuel cell. Using the first-principles method, we have performed computational screening on a series of transition metal (TM) atoms embedded in monolayer Nb2S2C to enhance the ORR activity. Through the scaling relationship and volcano plot, our results reveal that the introduction of a single Ni or Rh atom through substitutional doping into monolayer Nb2S2C yields promising ORR catalysts with low overpotentials of 0.52 and 0.42 V, respectively. These doped atoms remain intact on the monolayer Nb2S2C even at elevated temperatures. Importantly, the catalytic activity of the Nb2S2C doped with a TM atom can be effectively correlated with an intrinsic descriptor, which can be computed based on the number of d orbital electrons and the …

In this study, we report on the fabrication of Mo2S3/MoP2 composite thin films using a single-step aerosol assisted chemical vapor deposition method from a single-source precursor solution of [(ƞ5-Cp)Mo(CO)2(S2P(SC6H4Me)2)] (1). Deposition times of 20, 30, and 40 min were used to obtain thin films with different morphologies. Our investigation found that the 30-minute thin film, which had a widely distributed grainy morphology, exhibited the highest electrocatalytic performance for hydrogen evolution reaction (HER) as determined by linear sweep voltammetry studies. This film required the lowest applied potential of 250 mV to generate a current density of 10 mAcm−2 with a low charge transport resistance of 715 Ω, despite having the lowest charge donor density of 5.52 × 1019 cm−3. We found that the unique morphology of this thin film enhanced electron mobility, resulting in superior HER performance with a …

Thermal chemical vapor deposition investigated the growth-aligned manganese silicide (MnSi) nanowires on a c-Si(111) substrate. The growth, composition, and morphology of MnSi nanowires were studied in detail using X-ray diffraction, transmission electron microscopy, field emission electron microscopy, and X-ray photoelectron spectroscopy at different reaction pressures (0.03, 0.12, 0.52, 1.20, and 6.20 mbar). The effect of reaction pressure on the electrocatalytic activity of MnSi nanowires in the hydrogen evolution reaction (HER) was explored further. Compared to higher pressure, at lower pressure (0.12 mbar), the as-synthesized MnSi nanowire exhibits the greatest electrocatalytic performance (1.2 mbar). The electrochemical impedance spectroscopy analysis revealed that the increase in HER electrocatalytic activity of MnSi nanowires at a lower reaction pressure of 0.12 mbar is associated with increasing …

This work demonstrated the effects of 1.2 GeV high-energy electron beam irradiation on a few-layers of graphene (FLG) and multi-layer graphene (MLG) films grown via an in-house hot wire chemical vapour deposition (HWCVD) system. The FLG and MLG films were grown on highly doped n-type c-Si (100) substrates which were pre-treated using argon plasma (50 W) for 1 min and 10 min, respectively. The as-prepared samples were then irradiated using a 1.2 GeV high-energy electron beam with a dosage of 1.2× 109 e-/cm2 at atmospheric and room temperature ambient conditions. The effects of the irradiation-mediated defects on the carbon lattice structure of both graphene samples were validated from the decreased sp2 C= C carbon content, and the increase in the adventitious carbon contamination COC content. Raman results showed an elevation of the ID/IG ratio and blue-shift of the 2D and G band peaks for both the irradiated samples, which validated the mediated defects due to the dislocation of carbon atoms in the graphene sheets. The blue-shifted of 2D and G peaks were much more significant in the MLG than FLG which may indicate a better self-reconstructing property for the MLG atomic network, compared to the FLG. The stability of the films against high-energy electron beam irradiation was validated by their conductivity and surface topography. In conclusion, HWCVD grown graphene nanoplatelet films have high potential for graphene-based high-energy charged particle detectors.

This chapter describes various state-of-the-art fabrication routes for high-quality graphene included: chemical vapour deposition (CVD), mechanical exfoliation, chemical exfoliation, electrochemical exfoliation, arc discharge, epitaxial growth, and pyrolysis. CVD is a widely used technique for growing high-quality graphene films on metal catalyst substrates, and copper foil has shown promising results. Mechanical exfoliation involves peeling graphite flakes from highly oriented pyrolytic carbon (HOPG) platelets using Scotch tape, resulting in single-layer graphene. Chemical exfoliation has two methods: solution-assisted and low-temperature chemical exfoliation. Electrochemical exfoliation involves the intercalation and exfoliation of graphite into graphene nanosheets through electrolyte solutions. Arc discharge is a plasma deposition technique for synthesizing high-quality graphene sheets using alternating current …

In this paper, a breakthrough was achieved in large-scale production of N-doped Graphene Nano Sheets (N-GNS) using coconut fruits. The main objectives were to produce N-GNS on a large scale and assess its electrical conductivity. The process involved two key steps: first, producing GNS from coconut fruits through pyrolysis, and then generating N-GNS by doping with nitrogen using ammonia solution at room temperature. Various analytical techniques were used to characterize the produced N-GNS, including X-ray Diffraction (XRD), Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), Raman spectroscopy, and electrochemical cyclic voltammetry and electrochemical impedance spectroscopy. The XRD data indicated that the C (002) peak of N-GNS shifted to a higher 2θ value (2θ = 24.72° …

As the size of satellites are scaling down, low power and compact propulsion systems such as the Pulsed Plasma Thruster (PPT) are needed for stabilizing these miniature satellites in orbit. Most PPT systems have been operated at 2 J or more of discharge energy. In this work, the performance of a PPT with a side-fed, tongue-flared electrode configuration operated at a range of lower discharge energy of 0.5 to 2.5 J has been investigated. Ablation and charring of the Teflon propellant surface were analysed through Field Effect Scanning Electron Microscopy (FESEM) imaging and Energy Dispersive X-Ray (EDX) spectra. It was found that at discharge energy below 2 J, inconsistency in specific impulse and thrust efficiency resulted from the low mass bit measured. At energies more than 2 J, the performance parameters are compared and extensively discussed with other PPT systems of similar configuration.

This book highlights the versatility of graphene focusing on the background of graphene, its overall structure, superior properties, fabrication routes, characterization techniques, graphene composites/derivatives, and potential applications. A remarkable surge in interest for graphene and its applications has resulted in a substantial increase in the number of publications in terms of reviews and scientific articles, books and patents. Therefore, this book essentially addresses a wide range of graphene research and provides a great resource for beginners, students in sciences or engineering, researchers, professionals, and materials scientists.​

The present work covers the theoretical investigation of the \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\alpha $$\end{document}-decay half-lives of the even-even\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{{254,256}}$$\end{document}Rf chains using deformed relativistic Hartree–Bogoliubov theory in the continuum (DRHBc) formalism with the PC-PK1 parameter set. The effect of rotation on the stability of these neutron-deficient nuclei is appraised. Six different …

We calculate the structural, electronic and magnetic properties of the subgroup of Metal–Organic-Frameworks (MOFs) [AmH][M(HCOO)3] (in which AmH+ = organic ammonium cation, M = divalent metal ion) using density functional theory with GGA+U approximation. The optimized structures and magnetic ground states are in good agreement with available experimental results. The electronic structures of these MOFs are obtained at their magnetic ground states. Using hybrid functional method (HSE06), the band gap is 4.33 eV, 4.12 eV, 4.15 eV and 4.78 eV for NH2NH3+, HONH3+, CH3CH2NH3+ and NH4+ compounds, respectively. The band gap of NH2NH3+ varies from 2.63 eV (−5% compressive strain) to 3.50 eV (+5% tensile strain) at Ueff = 4 eV. It is demonstrated that the band gap of such MOFs can be easily tuned by applying external strain and the AmH+ ligand for the first time. These MOFs all show …

RSC_TC_vol_iss_D2TC90159E 11053..11062 Page 1 REVIEWS 11063 Charge transport materials for mesoscopic perovskite solar cells Maria Vasilopoulou,* Anastasia Soultati, Petros-Panagis Filippatos, Abd. Rashid bin Mohd Yusoff, Mohhamad Khadja Nazeeruddin* and Leonidas C. Palilis* 11105 Macromatrices for nanoscale particles Xue Bai, Finn Purcell-Milton and Yurii K. Gun’ko* IN THIS ISSUE ISSN 2050–7526 CODEN JMCCCX 10(31) 11051–11426 (2022) Cover See Samuel W. Thomas III et al., pp. 11199–11210. Artwork designed by Matthew Thomas and reproduced by permission of Samuel W. Thomas III from J. Mater. Chem. C, 2022, 10, 11199. Inside cover See Chin-Wei Lu, Hai-Ching Su et al., pp. 11211–11219. Image reproduced by permission of Hai-Ching Su from J. Mater. Chem. C, 2022, 10, 11211. Journal of Materials Chemistry C Materials for optical, magnetic and electronic devices rsc.li/…

This article reports the spectral properties of a Ge_2Sb_2Se_4Te_1 (GSST) -coated tilted fiber Bragg grating to the changes of surrounding refractive index (SRI). The variations of the cladding mode resonance amplitudes and wavelengths under two orthogonal polarization modes are analyzed and validated with the simulation results. The introduction of the high index coating has induced non-degeneracy to the cladding modes, but the effect gradually diminishes with increasing SRI. The SRI sensitivities of the s-polarized modes have been substantially suppressed and became 20 times lower than that of p-polarized modes. The findings also reveal the association between the cladding resonance amplitudes, the imaginary part of the effective refractive indices and the evanescent field intensity distributions.

The electrochromic (EC) window is a promising energy-saving smart window that can vary between three states: transparent, translucent, and opaque by applying low voltages. One of the potential EC materials is known as titanium dioxide (TiO2) due to its unique chemical and physical properties. Conventional post-annealing has been commonly employed for phase transition in EC thin films, but it suffers from drawbacks such as long treatment time and high energy consumption. Hence, in this study, TiO2 thin films were deposited on indium-doped tin oxide (ITO) and fluoride-doped tin oxide (FTO) glass substrates using a sol-gel spin coating technique, followed by a rapid post-annealing interval of 5 min at temperatures ranging from 300 to 450 °C. The optical, morphological, structural, and EC properties of TiO2 thin films were investigated. The measurement depicted that rapid post-annealing was a cost-effective …

Laser-induced microscale reactions are an excellent means to obtain controllable, small-scale insights into nanomaterial properties. Importantly, the opportunity for a comprehensive understanding of the material's optical origins allows for refined engineering of material luminescence. Modifying an array of standing indium oxide (In2O3) nanowires with a focused laser beam, we report newfound yellow and blue fluorescence emanating from the sample. Evaluated through a broad range of laser conditions, the laser-induced yellow component was found to relate to oxygen inclusions, while the blue fluorescence overlayer originated from oxygen physisorption upon prolonged storage. Capitalizing on the versatility of the blue emission component under UV modulation, we demonstrate micropatterns with multiple layers of differentiated optical encryption features. The enhanced anti-counterfeiting capability allows …

Obesity is strongly linked with increased risk and poorer prognosis of endometrial cancer (EC). Cancer-associated fibroblasts (CAFs) are activated fibroblasts that form a large component of the tumor microenvironment and undergo metabolic reprogramming to provide critical metabolites for tumor growth. However, it is still unknown how obesity, characterized by a surplus of free fatty acids drives the modifications of CAFs lipid metabolism which may provide the mechanistic link between obesity and EC progression. The present study aims to evaluate the utility of Raman spectroscopy, an emerging nondestructive analytical tool to detect signature changes in lipid metabolites of CAFs from EC patients with varying body mass index. We established primary cultures of fibroblasts from human EC tissues, and CAFs of overweight/obese and nonobese women using antibody-conjugated magnetic beads isolation. These …

Enhancing the charge separation efficiency through interface engineering of In2O3-based photoanodes represents a critical and complex research endeavor in the field of water splitting. Herein, we report a self-catalyzed growth of intrinsic Indium oxide (In2O3) Nanowires (NWs) and Tungsten nitride/Indium oxide (W2N/In2O3) composite nanowires (CNWs) on c-Si substrates by plasma assisted reactive thermal evaporation (PARTE) and nitrogen plasma assisted in-situ thermal annealing, respectively. The nitrogen plasma assisted in-situ thermal annealing effectively transforms the intrinsic In2O3 NWs to W2N/In2O3 CNWs. The optical energy gap, Eg gradually decreases from 2.49 to 2.40 eV when combine with W2N nanostructures. Decrease in the Eg simultaneously increases the photocurrent density of W2N/In2O3 CNWs at V = 0.4 V from 1.9 to 3.8 mA/cm2. This could attribute to the effective electron−hole …

Electrochemical hydrogen evolution reaction (HER) refers to the process of generating hydrogen by splitting water molecules with applied external voltage on the active catalysts. HER reaction in the acidic medium can be studied by different mechanisms such as Volmer reaction (adsorption), Heyrovsky reaction (electrochemical desorption) or Tafel reaction (recombination). In this paper, facile hydrothermal methods are utilized to synthesis a high-performance metal-inorganic composite electrocatalyst, consisting of platinum nanoparticles (Pt) and molybdenum disulfide nanosheets (MoS2) with different platinum loading. The as-synthesized composite is further used as an electrocatalyst for HER. The as-synthesized Pt/Mo-90-modified glassy carbon electrode shows the best electrocatalytic performance than pure MoS2 nanosheets. It exhibits Pt-like performance with the lowest Tafel slope of 41 mV dec−1 …

To estimate the decay half-lives, the semiempirical used here include:(1). Modified Viola-Seaborg semi-empirical formula (MVS)[4]: contains two asymmetry terms and hold a linear relationship with the

In this study, monolayer up to few-layer of Mn3O4 nanosheets grown on c-Si (111) substrates using a thermal chemical vapor deposition (TCVD) technique were investigated in detail, where the growth reaction pressure was varied from 0.12 to 0.72 mbar. The morphology of the triangular-shaped Mn3O4 nanosheet greatly depends on the atomic ratio of O to Mn, which eventually determines the horizontal growth rate of the triangle's edges that forms the shape of the nanosheet. A low O/Mn ratio results in the formation of a triangle with a longer edge as compared to a high O/Mn ratio which produces a shorter edge. The 2D triangular-shaped Mn3O4 nanosheets prepared at 0.42 mbar exhibited a thickness of ∼1.10–2.29 nm (equivalent to the approximate thickness of monolayer-bilayer) with a maximum edge length of ∼850 nm, whereas ultrathin nanosheets with a thickness of ∼1.93–4.68 nm (equivalent to ∼2–3 …