Collection's Items (Sorted by Submit Date in Descending order): 1 to 20 of 403
- Journal Article
Authors: Swathi, S.P.; Angappane, S. (2021) - The stochastic nature of conductive filament formation and dissolution always leads to large fluctuations
of key device parameters that hinder the practical applications of resistive random-access memories
(RRAMs). Here, we report a simple bilayer oxide-based device structure of Al/TiOx/TiOy/FTO (x < y)
employed to address this variability issue and improve the overall performance of the memory device.
The bipolar resistive switching performance remarkably improved in these bilayer devices with lower
forming voltage (~1 V), set/reset voltages of 0.4/-0.6 V, a programming current of 10 mA, an enlarged ON/
OFF ratio (>103), longer retention (>103 s), and better uniformity as compa...
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- Journal Article
Authors: Perevalov, Timofey V.; Prosvirin, Igor P.; Suprun, Evgenii A.; Mehmood, Furqan; Gritsenko, Vladimir A. (2021) - HfxZr1-xO2 and lanthanum-doped HfxZr1-xO2:La thin films are candidates for applications in ferroelectric
random-access memory. Here, we explore the atomic and electronic structure of Hf0.5Zr0.5O2 and
Hf0.5Zr0.5O2:La thin films grown by atomic layer deposition. Using X-ray photoelectron spectroscopy, it
was found that the oxides under study have an almost identical electronic structure and a bandgap of
about 5.4 eV. The Hf0.5Zr0.5O2:La film was shown to consist of the mixture of Hf0.5Zr0.5O2 and La2O3
phases. The bombardment with argon ions of the studied films leads to oxygen vacancy generation in the
near-surface layer. The oxygen vacancy concentrations in the bombarded films w...
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- Journal Article
Authors: Wang, Y.F.; Yu, Y.Y.; Belliveau, H.; N., T.M. Duc; Phan, M.H. (2021) - A novel class of nanocrystalline/amorphous Gd3Ni/Gd65Ni35 composite microwires were created directly
from melt-extraction through controlled solidification. X-ray diffraction (XRD), transmission electron
microscopy (TEM), and selected area electron diffraction (SAED) confirmed the formation of a biphase
nanocrystalline/amorphous structure in these wires. Magnetic and magnetocaloric experiments indicate
a large magnetic entropy change (-DSM ~9.64 J/kg K), large refrigerant capacity (RC ~742.1 J/kg), and large
maximum adiabatic temperature change (DTmax
ad ~5 K) around the Curie temperature of ~120 K for a field
change of 5 T. These values are ~1.5 times larger relative to its bu...
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- Journal Article
Authors: Qinhan, Wu; Xuran, Wang; Jiawei, Fu; Osman, Ahmed Zelekew; Xiaoyun, Chen (2021) - Wool-coiled MoSrOS bimetal oxysulfide catalysts were synthesized by a simple method. The catalysts
were characterized by different instruments. The MoSrOS reduction activities were also investigated by
the reduction of Cr(VI), Rhodamine-B (RhB), Methyl orange (MO), Methylene blue (MB) and 4-
nitrophenol (4-NP). The results showed that 100 mL (20 ppm) of 4-NP was completely reduced into
4-aminophenol (4-AP) in 20 min. Moreover, 100 mL (20 ppm) of MB, 100 mL (50 ppm) of RhB, 100 mL
(50 ppm) of MO and 100 mL (50 ppm) of Cr(VI) were completely reduced within 6, 20, 40, and 30 min,
respectively, by MoSrOS-2 bimetal oxysulfide catalyst. Hence, the wool-coiled MoSrOS bimetal oxysulfide...
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- Journal Article
Authors: Nguyen, Van Hoa; Pham, Anh Dat; Nguyen, Van Chi; Le, Hong Quan (2021) - A three-dimensional reduced graphene oxide/nickel-cobalt sulfide (RGO/NiCo2S4) aerogel was fabricated
by an efficient and facile one-step hydrothermal approach. The NiCo2S4 needle-like structure consisted of
many small nanoparticles well attached to the surface of the RGO sheet. The prepared aerogel had high
porosity and conductivity. As an active electrode material for supercapacitors, the RGO/NiCo2S4 aerogel
exhibited a large capacitance of 813 F g 1 at 1.5 A g 1. Besides, the asymmetric supercapacitor (RGO/
NiCo2S4 aerogel//RGO) showed a Cs of 45.3 F g 1 at 1.0 A g 1 and a suitable remaining capacitance of over
84.3 % after 2000 cycles. The asymmetric supercapacitor had a hig...
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- Journal Article
Authors: Mohammadi, Hossein; Baba Ismail, Yanny Marliana; Shariff, Khairul Anuar; Ahmad-Fauzi, Mohd Noor (2021) - The effects of cobalt (Co) substitution on the structural, physico-mechanical properties, as well as the
in vitro bioactivity and biodegradability of akermanite (Ca2MgSi2O7) are studied. The XRD patterns
showed that the Co substitution did not change the Ca2MgSi2O7 phase. The FESEM micrographs revealed
that the partial substitution of Co increased the shrinkage and density of Ca2MgSi2O7 and reduced the
grain size. The Co substitution showing the highest mechanical response was 2 mol%. However, the
mechanical properties decreased beyond 2 mol% due to the larger grain size. The in vitro degradation test
showed that Co substitution altered the degradation profile of Ca2MgSi2O7. How...
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- Journal Article
Authors: Pham, Van Viet; Nguyen, Hoang-Phuong; Tran, Hong-Huy; Bui, Dai-Phat; Cao, Minh Thi (2021) - The facile fabrication of g-C3N4/SnO2 S-scheme heterojunctions for photocatalytic removal of NO under
visible light is reported. Optical and electrochemical investigations indicate the formation of these
heterojunctions that enable bending at the interface of g-C3N4 and SnO2 and give rise to an efficient
separation. A high photocatalytic 500-ppb NO removal performance of 35% and low NO2 generation of 2%
are realized after 30 min of visible light irradiation upon the g-C3N4/SnO2 heterojunction with 30% of g-
C3N4 addition. In contrast, the bare g-C3N4 extensively produces NO2 greater than 12% compared to 30%
from the g-C3N4 sample. This study also shows that the g-C3N4/SnO2 heter...
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- Journal Article
Authors: Leoncini, Mauro; Giannuzzi, Roberto; Giuri, Antonella; Colella, Silvia; Gambino, Salvatore (2021) - The exploitation of methylammonium lead iodide perovskite-polymer composites is a promising strat-
egy for the preparation of photoactive thin layers for solar cells. The preparation of these composites is a
simple fabrication method with improved moisture stability when compared to that of pristine perov-
skite films. To deepen the understanding of the charge transport properties of these films, we investi-
gated charge carrier mobility, traps, and ion migration. For this purpose, we applied a combinatory
measurement approach that proves how such composites can still retain an ambipolar charge transport
nature and the same mobility values of the related perovskite. Furthermore,...
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- Journal Article
Authors: Tsai, Hsin-Jung; Li, Wei-Chun; Hsu, Wen-Kuang (2021) - Composites made from multi-walled carbon nanotubes and polydimethylsiloxane exhibit an excellent
piezoresistivity at elastic limits where strain sensitivity reaches 0.93e0.96 and resistance changes due to
stretching and compressing matches with loading histograms. Resistance change becomes pulse-like as
the samples are bent and/or twisted, attributed to the rapid increase in intertube spacing. Straining
induces movements and segmentations of tube aggregates with tube mobility ranging at 0.1e90 nm/s.
Intertube barrier driven sensing mechanism is viscoelasticity related and is therefore interpreted on the
basis of spring-dashpot models.
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- Journal Article
Authors: Ahmad, Husain (2021) - Polythiophene (PTh) and polythiophene/molybdenum oxide nanocomposites (PTh/MoO3) were syn-
thesized by an in-situ chemical oxidative method. The successful synthesis of both the materials was
confirmed by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron
microscopy (SEM), and transmission electron microscopy (TEM). The thermal stability of the materials
was examined in terms of conductivity retention under isothermal and cyclic aging conditions. PTh/
MoO3 showed much greater conductivity retention (i.e., thermal stability) than pristine PTh under both
conditions. PTh/MoO3 showed 18.22 times greater electrical conductivity than pristine P...
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- Journal Article
Authors: Le, T. Thanh-Lieu; Le, T. Thanh-Hiep; Nguyen, Van Kim; Bui, Hao Van; Vo, Vien (2021) - This work presents the controlled synthesis of TiO2/graphene photocatalysts by hydrothermal method
using TiCl4 as a precursor. The influence of the precursor concentration and the reaction time on the
growth of TiO2 nanoparticles on graphene was studied, showing the ability to achieve the catalysts with
desired TiO2 loadings and dispersion. By means of XPS, Raman, and UV-VIS diffuse reflectance spec-
troscopies, the chemical composition, the interaction between TiO2 and graphene, and the optical
properties of the photocatalysts were investigated. The results reveal that the coupling with graphene
considerably narrows the bandgap of TiO2, which stimulates the photocatalytic activ...
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- Journal Article
Authors: Nguyen, My V.; Dong, Hieu C.; Nguyen, Duc Manh; Vu, Nam H.; Phan, Thang B. (2021) - We study the proton conductivity properties of MOF-801. We find that MOF-801 possesses intrinsic
proton carrier sites, m3-OH groups, in clusters yielding the generation of hydrogen-bonding networks
with guest water molecules at high relative humidity (RH), facilitating proton transport. Remarkably, this
material has a high proton conductivity of 1.82 10 3 S cm 1 under 98% RH at 90 C and maintains its
performance over an extended time. Our investigations reveal that the increase in proton conductivity is
correlated to numerous hydrogen bonds within the MOF structure. The activation energy of this process
is low (Ea ¼ 0.21 eV), showing that the protons hop through the membrane ...
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- Journal Article
Authors: Goswami, Manoj; Kumar Yadav, Ashvini; Chauhan, Viplov; Singh, Netrapal; Srivastava, A.K. (2021) - COVID-19 belongs to a typical class of viruses that predominantly affects the human respiratory system,
thereby proving to be fatal to many. The virus, along with other air pollutant particulates poses a severe
threat to the human respiratory organs. Since the most common transmission mode is respiratory fo-
mites and aerosol particulates, it is necessary to prevent their ingression through a mask. The primary
use of masks is to prevent aerial particulates. This paper reveals the development of masks with air filters
coated with functionalized graphene (fG) mounted on a 3D-printed facial mask replica. The fused
deposition modeling (FDM) process is used for fabricating the facial...
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- Journal Article
Authors: Wensen, Jing; Lei, Feng; Bo, Wang; Weisong, Zhang; Kan, Peng (2021) - The osteoblast cell growth and cancer cell inhibition of titanium (Ti) metal implant coated with polyvinyl
alcohol (PVA) reinforced hydroxyapatite (HAP) composite were investigated. The fibrous composite of
PVA/HAP/folic acid (FA)/Methotrexate (MTX) was coated on the surface of a titanium plate and observed
with microscopy. During the PVA/HAP/FA/MTX composite's preparation, the functional changes and
crystalline phases were observed through Fourier-transform infrared spectroscopy and X-ray diffraction
analysis, respectively. The fiber composite had an average diameter of 19 nm and a greater mechanical
strength (9660 Pa) than that of pure HAP (4965 Pa), critical to the fibrous sc...
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- Journal Article
Authors: Wu, Z.; Korntner, S.H.; Mullen, A.M.; Zeugolis, D.I. (2021) - The limited capability of articular cartilage to self-repair renders its regeneration a formidable challenge.
In the quest of the optimal material for cartilage scaffold fabrication, the use of collagen type II has been
advocated, but its optimal source still remains elusive. Herein, the potential of four [lesser spotted
dogfish (Scyliorhinus canicula), thorn back ray (Raja clavata), cuckoo ray (Leucoraja naevus) and blonde
ray (Raja brachyuran)] cartilaginous fish (chondrichthyes) derived collagen type II preparation in cartilage
engineering was assessed. Collagen type II was extracted using the acid-pepsin method, crosslinked with
4-arm poly (ethylene glycol) succinimidyl glut...
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- Journal Article
Authors: Tieu, Tu Doanh; Nguyen, Van Hieu; Ton, Nu Quynh Trang; Vu, Thi Hanh Thu (2021) - Micro-structured molecular semiconductor film-based surface-enhanced Raman scattering (SERS)
probes are an important analytical tool for both fundamental and technological research. This study
proposed a novel zinc oxide (ZnO)-based, three-dimensional (3D) semiconductor nanoflower (NF) su-
perstructure probe with unique physicochemical properties, including engineered hotspots allowing an
arrangement of metallic nanoparticles (NPs), as a means to analyse target molecules. By changing the
size, high-density hotspots distributed throughout the nanopetal-like ‘nanorods’ of ZnO supports. When
used to analyse crystal violet (CV), there were synergistic effects of silver (Ag), ZnO, an...
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- Journal Article
Authors: Kim, Hyun Gi; Kim, Mansu; Kim, Sung Soo; Sang, Hyun Paek; Kim, Young Chul (2021) - We prepared a hybrid electrode comprosed of a silver nanowires/poly (3,4-ethylenedioxythiophene):
poly(styrenesulfonate) (AgNW/PEDOT:PSS) nanocomposite for flexible organic light-emitting diodes
(FOLEDs). To increase the conductivity of PEDOT:PSS, diethylene glycol (DEG) was introduced into the
PEDOT:PSS solution. The PEDOT:PSS layer shows a higher figure of merits (FoM) when prepared with the
optimum amount of 7 vol%-DEG in the coating solution, due to the three-dimensional conducting
network formed in the hybrid electrode. The perfluorinated ionomer (PFI) was also introduced into the
PEDOT:PSS solution, and the resulting polymer solution was used to prepare a transparent anode...
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- Journal Article
Authors: Charoeythornkhajhornchai, Pollawat; Tedsree, Karaked; Chancharoen, Ratchatin (2021) - Over a short period of time, electronic assemblies have been dramatically developed with smaller size and lighter weight and 3D printing plays a crucial role in their future production. However, it is difficult to develop epoxy resins and other thermoset resins for this process because of the polymer's liquid state during processing. This work uses a UV curing technique for making flexible epoxy/multi-walled carbon nanotubes (MWCNTs) composites that are suitable for future 3D printing applications. The synthesized carbazole-coated TiO2 nanoparticles, used as a photosensitizer, were characterized by their photoabsorbance, morphology, and surface property before use. The results indicat...
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- Journal Article
Authors: Monnappa, Amrutha Balliamada; Manjunatha, Jamballi Gangadharappa Gowda; Bhatt, Aarti Sripathi; Nagarajappa, Hareesha (2021) - Vanillin (VN) is a flavouring substance commonly used in the food and pharmaceutical industry. The rampant use of VN has significant implications on human health. In this work, a sensitive and selective voltammetric sensor to detect VN in food essences and natural vanilla beans was elucidated using a poly(methyl orange) modified graphene paste electrode (PMOMGPE). The surface morphology of PMOMGPE and a bare graphene paste electrode (BGPE) was compared using field emission - scanning electron microscopy (FE-SEM) and electron transfer kinetics were analysed by Electrochemical impedance spectroscopy (EIS). The electrochemical activities of PMOMGPE and BGPE were assessed using cyclic vol...
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- Journal Article
Authors: Goswami, Manoj; Yadav, Ashvini Kumar; Chauhan, Viplov; Singh, Netrapal; Srivastava, A.K. (2021) - COVID-19 belongs to a typical class of viruses that predominantly affects the human respiratory system, thereby proving to be fatal to many. The virus, along with other air pollutant particulates poses a severe threat to the human respiratory organs. Since the most common transmission mode is respiratory fomites and aerosol particulates, it is necessary to prevent their ingression through a mask. The primary use of masks is to prevent aerial particulates. This paper reveals the development of masks with air filters coated with functionalized graphene (fG) mounted on a 3D-printed facial mask replica. The fused deposition modeling (FDM) process is used for fabricating the facial mask re...
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Collection's Items (Sorted by Submit Date in Descending order): 1 to 20 of 403
