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  • Authors: L.T.Anh; P.V.Cuong; H.T.Thao; N.H.Tan; K.T.Thanh;  Advisor: -;  Co-Author: - (2022)

    In this work, we developed a Geant4-based code, IS-2020, for photonuclear studies below 200 MeV covering the giant dipole resonance region (GDR). It uses G4LowEGammaNuclearModel, which consists of preequilibrium and equilibrium reaction mechanisms, for sampling the final states of photonuclear reactions. Simulations for photonuclear reactions on 96Mo, 90Zr, and the strongly-deformed nucleus 153Eu targets have been performed for its validation. Moreover, a good agreement was also observed between experimental relative yields and the simulation results of 59Co(,2n)57Co and 50Cr(,2n)48Cr reactions induced by bremsstrahlung. The implemented code will be a useful and reliable tool for photonuclear studies, including designing the experimental setup, estimating the yield of outgoing produ...

  • Authors: Mai Quan Doan; Nguyen Ha Anh; Hoang Van Tuan; Nguyen Cong Tu; Nguyen Huu Lam; Nguyen Tien Khi; Vu Ngoc Phan; Pham Duc Thang; Anh-Tuan Le;  Advisor: -;  Co-Author: - (2021)

    Multifunctional nanocomposites have received great attention for years; electron transfer (ET) is considered as an explanatory mechanism for enhancement of performance of these nanostructures. The existence of this ET process has been proved in many studies using either experimental or computational approaches. In this study, a ternary nanocomposite system of Ag/TiO2/GO was prepared to evaluate the performance enhancement in two experimental models: a physical model (i.e., surface-enhanced Raman scattering (SERS) sensor) and a chemical one (i.e., catalytic reduction reaction). The metal/semiconductor heterojunction between Ag and TiO2, as well as Ti-O-C bonds, has allowed plasmonic hot electrons to be transferred in the internal structure of the material. An investigation on the rol...

  • Authors: Tran, Quoc Quan; Do, Thi Thu Ha; Nguyen, Dinh Duc;  Advisor: -;  Co-Author: - (2022)

    This paper presents the nonlinear vibration of porous functionally graded sandwich plate on elastic foundations subjected to blast loading by the analytical approach. The sandwich plate consists of two FGM face sheets and a homogeneous core which is made from metal or ceramic. Two types of porosity distribution, including evenly and unevenly distributed porosity have been considered for sandwich plate. The material properties of sandwich plate are assumed to vary in the thickness direction according to simple power law distribution with a volume fraction index and a porosity coefficient. The blast loading is assumed to be uniformly distributed on the surface of the sandwich plate and modeled by an exponential function. The Reddy’s higher order shear deformation theory with von Kármá...

  • Authors: Nguyen, Ngoc Huyen; Ngo, Xuan Dinh; Mai, Quan Doan;  Advisor: -;  Co-Author: - (2022)

    In this work, we investigated the effect of morphology on the analytical performance of α-Fe2O3 nanostructures-based electrochemical sensors toward chloramphenicol (CAP) antibiotic using three designed morphologies including α-Fe2O3 nano-tube (α-Fe2O3-T), α-Fe2O3 nano-rice (α-Fe2O3-R), and α-Fe2O3 nano-plate (α-Fe2O3-P). Among these morphologies, α-Fe2O3-T displayed an outstanding electrochemical activity owing to the unique hollow structure and large specific surface area. However, due to the small pores size, α-Fe2O3-T showed the high steric hindrance (SD) effect towards an antibiotic with complex molecular structure, as CAP, leading to a significant decrease of their CAP electrochemical sensing performance. The CAP analytical performance of α-Fe2O3-R was highest in investigated m...

  • Authors: Abdullah H. Alshehri; Jhi Yong Loke; Viet Huong Nguyen; Alexander Jones; Hatameh Asgarimoghaddam; Louis-Vincent Delumeau; Ahmed Shahin; Khaled H. Ibrahim; Kissan Mistry; Mustafa Yavuz; David Muñoz-Rojas; Kevin P. Musselman;  Advisor: -;  Co-Author: - (2021)

    Nanoscale films are integral to all modern electronics. To optimize device performance, researchers vary the film thickness by making batches of devices, which is time-consuming and produces experimental artifacts. Thin films with nanoscale thickness gradients that are rapidly deposited in open air for combinatorial and high-throughput (CHT) studies are presented. Atmospheric pressure spatial atomic layer deposition reactor heads are used to produce spatially varying chemical vapor deposition rates on the order of angstroms per second. ZnO and Al2O3 films are printed with nm-scale thickness gradients in as little as 45 s and CHT analysis of a metal-insulator-metal diode and perovskite solar cell is performed. By testing 360 Pt/Al2O3/Al diodes with 18 different Al2O3 thicknesses on o...

  • Authors: Xiaoyu, Zhang; Thien Van, Luong; Periklis, Petropoulos;  Advisor: -;  Co-Author: - (2022)

    End-to-end learning systems are conceived for Orthogonal Frequency Division Multiplexing (OFDM)-aided optical Intensity Modulation paired with Direct Detection (IM/DD) communications relying on the Autoencoder (AE) architecture in deep learning. We first propose an AE-aided Layered ACO-OFDM (LACO-OFDM) scheme, termed as LACONet, for exploiting the increased bandwidth efficiency of LACO-OFDM. LACONet employs a Neural Network (NN) at the transmitter for bit-to-symbol mapping, and another NN at the receiver for recovering the data bits, which together form an AE and can be trained in an end-to-end manner for simultaneously minimizing both the BER and PAPR. Moreover, the detection architecture of LACONet is drastically simplified compared to classical LACO-OFDM, since the Fast Fourier T...

  • Authors: Nguyen, Ha Anh; Mai, Quan Doan; Ngo, Xuan Dinh;  Advisor: -;  Co-Author: - (2022)

    Electrochemically synthesized gold nanoparticles (e-AuNPs) were deposited on aluminum substrates to fabricate effective surface enhanced Raman spectroscopy (SERS) sensors for thiram and CAP monitoring in food samples, between which the thiram sensor showed better performance in terms of sensibility, reliability and practicability. Regarding that the differences in SERS performance of the two sensors were closely associated to the distinction in molecular structure of the two analytes, we investigated the effects of analyte molecular structure on the sensing performance, especially the enhancement factors (EFs), of the sensors. As the enhancement of SERS signal is explained by both chemical and electromagnetic mechanisms (CM and EM), the investigation was also carried out in two dire...

  • Authors: Do, Thi Mai Dung; Eun, Jae Park; Duong, Tien Anh;  Advisor: -;  Co-Author: - (2022)

    A biological evaluation revealed that all thirteen compounds designed and synthesized showed strong cytotoxicity against three human cancer cell lines (SW620, colon cancer; PC-3, prostate cancer; NCI-H23, lung cancer) with eight compounds (5a, 5c-i, 5k), which were clearly more potent than both PAC-1 and oncrasin-1. In this series, four compounds, including 5c, 5e, 5f, and 5h, were the most potent members with approximately 4- to 5-fold stronger than the reference compounds PAC-1 and oncrasin-1 in terms of IC50. In comparison to 5-FU, these compounds were even 18- to 29-fold more potent in terms of cytotoxicity in three human cell lines tested. In the caspase activation assay, the caspase activity was activated to 285% by compound 5e compared to PAC-1, the first procaspase activatin...

  • Authors: Dieu D Nguyen; Takuma Izumi; Sabine Thater; Masatoshi Imanishi; Taiki Kawamuro; Shunsuke Baba; Suzuka Nakano; Jean L Turner; Kotaro Kohno; Satoki Matsushita; Sergio Mart�n; David S Meier; Phuong M Nguyen; Lam T Nguyen;  Advisor: -;  Co-Author: - (2021)

    We present a supermassive black hole (SMBH) mass measurement in the Seyfert 1 galaxy NGC 7469 using Atacama Large Millimeter/submillimeter Array (ALMA) observations of the atomic-[CI](1–0) and molecular-12CO(1–0) emission lines at the spatial resolution o