12 research outputs found
Erratum: The inactivation mechanism of chemical disinfection against SARS-CoV-2: The MD and DFT perspectives(RSC Advances (2020) 10 (40480–40488) DOI: 10.1039/D0RA06730J)
The authors regret that one of the affiliations (affiliation f) was incorrectly omitted in the original manuscript. The corrected list of affiliations is as shown below. The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.</p
The inactivation mechanism of chemical disinfection against SARS-CoV-2: From MD and DFT perspectives
Exploring effective disinfection methods and understanding their mechanisms on the new coronavirus is becoming more active due to the outbreak of novel coronavirus pneumonia (COVID-19) caused by severe acute respiratory coronavirus 2 (SARS-CoV-2). By combining molecular dynamics and first-principles calculations, we investigate the interaction mechanism of chemical agents with 3CL hydrolase of SARS-CoV-2. The radial distribution functions indicate that the biocidal ingredients are sensitive to the unsaturated oxygen atoms of 3CL hydrolase and their interactions remarkably depend on the concentration of the biocidal ingredients. Besides, we find that the adsorption performance of the active ingredients for the unsaturated oxygen atoms is superior to other styles of atoms. These computational results not only decipher the inactivation mechanism of chemical agents against SARS-CoV-2 from the molecule-level perspective, but also provide a theoretical basis for the development and application of new chemical methods with a high disinfection efficiency. Electronic Components, Technology and Material
Coalescence kinetics and microstructure evolution of Cu nanoparticles sintering on substrates: a molecular dynamics study
Nano copper sintering technology has great potential to be widely applied in the wide-bandgap semiconductor packaging. In order to investigate the coalescence kinetics of copper nano particles for this application, a molecular dynamic (MD) simulation was carried out at low temperature on a special model containing two substrate and multiple particles in between. Accordingly, thorough microstructure and dislocation investigation was conducted to identify the atomic-scale evolution in the system. The corresponding findings could provide evidence on the new particle-substrate sintering mechanism. Furthermore, atomic trajectories tracking method was applied to study the rotation behavior of different sized nano particles. New rotation behavior and mechanism were described. Additionally, the study on the size effect of copper particles on the sintering process and coalescence mechanism was conducted via comparing the microstructural and dislocation distribution of 3 nm, 4 nm and 5 nm models. Finally, by comparing the MSD results at low and high temperature for each model, the dominant coalescence dynamics changes were obtained.Electronic Components, Technology and Material
Erratum: The inactivation mechanism of chemical disinfection against SARS-CoV-2: The MD and DFT perspectives(RSC Advances (2020) 10 (40480–40488) DOI: 10.1039/D0RA06730J)
The authors regret that one of the affiliations (affiliation f) was incorrectly omitted in the original manuscript. The corrected list of affiliations is as shown below. The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.Electronic Components, Technology and Material
A theoretical study of atmospheric pollutant NO<sub>2</sub> on as-doped monolayer WS<sub>2</sub> based on DFT method
For the relevant properties of pristine and doped (Si, P, Se, Te, As) monolayer WS2 before and after the adsorption of CO, CO2, N2, NO, NO2 and O2, density functional theory (DFT) calculations are made. Calculation results reveal that the monolayer WS2 doped with P and As atoms can be substrate materials for NO and NO2 gas sensors. However, after the subsequent CDD and ELF calculations, it is found that P-doped monolayer WS2 adsorbs NO and NO2 in a chemical way, while As-doped monolayer WS2 adsorbs NO and NO2 in a physical way. Also, the charge transfer between As-doped monolayer WS2 and NO is relatively small and not easily detected. Besides, As-doped monolayer WS2 system exhibits greater differences in optical properties (the imaginary part of reflectivity and dielectric function) before and after the adsorption of NO2 gas than before and after adsorption of NO gas. These differences in optical properties assist sensor devices in making gas adsorption-related judgments. Through the analysis of the recovery time, DOS and PDOS, As-doped monolayer WS2 is also verified to be a promising NO2 sensing material, whose recovery time is calculated to be as short as 0.169 ms at 300 K.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Components, Technology and Material
Stretchable strain sensor based on HfSe<sub>2</sub>/LIG composite with high sensitivity and good linearity within a wide range
Flexible strain sensors based on nanomaterials have sparked a lot of interest in the field of wearable smart electronics. Laser induced graphene (LIG) based sensors in particular stand out due to their straightforward fabrication procedure, three-dimensional porous structures, and exceptional electromechanical capabilities. Recent studies have focused on LIG composites, however, it is still difficult to achieve great sensitivity and excellent linearity in a wide linear working range. Herein, a strain sensor with high sensitivity and good linearity is prepared in this work, which was realized by carbonizing the polyimide film coated with HfSe2 to obtain three-dimensional porous graphene nanosheets decorated with HfSe2 (HfSe2/LIG). After being transferred to the flexible substrate of Ecoflex, it exhibits high stretchability, hydrophobicity and robustness, and obtains excellent electromechanical properties. The HfSe2/LIG strain sensor demonstrated high sensitivity (gauge factor, GF ≈ 46), a low detection limit (0.02%), good linearity (R2 = 0.99) in a large working range (up to 30%), and a quick response time (0.20 s). Additionally, it exhibits good stability and consistent behavior across a large number of strain/release test cycles (>3000 cycles). With these benefits, the sensor can be used to monitor various limb movements (including finger, wrist and neck movements) and minute artery activity, and can generate reliable signals. Therefore, the HfSe2/LIG-based sensor has enormous potential for use in wearable intelligent electronics and movement monitoring.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Bio-ElectronicsElectronic Components, Technology and Material
Effects of shell thickness on the thermal stability of Cu-Ag core-shell nanoparticles: A molecular dynamics study
Cu-Ag core-shell (CS) nanoparticle (NP) is considered as a cost-effective alternative material to nano silver sintering material in die attachment application. To further reduce the cost, the thickness of the Ag shell can be adjusted. Whereas the shell thickness will also affect the thermal stability of the Cu-Ag CSNPs. In this study, molecular dynamics simulation was applied to study the thickness effect on the thermal behavior of Cu-Ag CSNPs. The melting points of CSNPs and Pure NPs can be determined by the evolutions of Potential Energy (PE), and the Lindemann index (LI) of the system. The results indicated that the melting points of CS NPs were lower than monometallic NP and the melting point of CS NP is influenced by the size of the Cu core and the number of lattice mismatches. Moreover, the distribution of atoms’ LI showed that the premelting point is independent of shell thickness. However, the fraction of atoms that occurred premelting is increased with the decrease of the shell thickness. Otherwise, we also simulated the sintering process of double CS NPs with equal size.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Components, Technology and Material
Room temperature ppt-level NO<sub>2Â </sub>gas sensor based on SnO <sub>x</sub>/SnS nanostructures with rich oxygen vacancies
In this paper, tin oxidation (SnO x )/tin-sulfide (SnS) heterostructures are synthesized by the post-oxidation of liquid-phase exfoliated SnS nanosheets in air. We comparatively analyzed the NO2 gas response of samples with different oxidation levels to study the gas sensing mechanisms. The results show that the samples oxidized at 325 °C are the most sensitive to NO2 gas molecules, followed by the samples oxidated at 350 °C, 400 °C and 450 °C. The repeatabilities of 350 °C samples are better than that of 325 °C, and there is almost no shift in the baseline. Thus this work systematically analyzed the gas sensing performance of SnO x/SnS-based sensor oxidized at 350 °C. It exhibits a high response of 171% towards 1 ppb NO2, a wide detecting range (from 1 ppb to 1 ppm), and an ultra-low theoretical detection limit of 5 ppt, and excellent repeatability at room temperature. The sensor also shows superior gas selectivity to NO2 in comparison to several other gas molecules, such as NO, H2, SO2, CO, NH3, and H2O. After X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscope, and electron paramagnetic resonance characterizations combining first principle analysis, it is found that the outstanding NO2 sensing behavior may be attributed to three factors: The Schottky contact between electrodes and SnO x/SnS; active charge transfer in the surface and the interface layer of SnO x/SnS heterostructures; and numerous oxygen vacancies generated during the post-oxidation process, which provides more adsorption sites and superior bandgap modulation. Such a heterostructure-based room-temperature sensor can be fabricated in miniaturized size with low cost, making it possible for large-scale applications.Electronic Components, Technology and Material
Strain-engineered S-HfSe<sub>2</sub> monolayer as a promising gas sensor for detecting NH<sub>3</sub>: A first-principles study
The development of high-performance gas sensing materials is one of the development trends of new gas sensor technology. In this work, in order to predict the gas-sensitive characteristics of HfSe2 and its potential as a gas-sensitive material, the interactions of nonmetallic element (O, S, Te) doped HfSe2 monolayer and small molecules (NH3 and O3) have been studied by first-principles based on density functional theory. The results show that the adsorption of NH3 and O3 on pristine HfSe2 monolayer is weak, and the adsorption strength can be significantly improved by doping O. And O-HfSe2 is chemical adsorption to O3 with large adsorption energy and transfer charge, and the band gap of O[sbnd]HfSe2 disappears after adsorbing O3, indicating that the adsorption of O3 has a significant effect on the electrical properties of the substrate. These mean that O3 is difficult to recover from the substrate surface, thus preventing O-HfSe2 from developing into a sensitive material for O3 detection. After doping S, the charge transfers and adsorption strength to NH3 are the largest, but it is still small. So, the strain effect on the S-HfSe2/NH3 adsorption system is also studied. The results indicate that the adsorption strength of S-HfSe2 to NH3 can be enhanced by stretching S-HfSe2 along x-axis. After absorbing NH3, the conductivity of x-axis strained S-HfSe2 changes, which suggest its sensitivity. And the predicted recovery times of S-HfSe2 surfaces with εx=4%, 6% and 8% are 0.027 s, 1.153 s and 102.467 s, respectively, which suggests that the S-HfSe2 monolayer has the potential to be developed as a sensitive material for NH3 detection. These adsorption mechanism studies can also serve as a theoretical foundation for the experimental design of gas-sensing materials.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Components, Technology and Material
Performance of first Bi-2212 cable with pre-over pressure and over pressure heat treatment
Due to the excellent current carrying performance of Bi2Sr2CaCu2O8+x (Bi-2212) and the development of its industrial manufacturing technology, Bi-2212 is a promising material to be developed as superconductor for application in fusion reactor magnets. The cable-in-conduit conductor (CICC) concept is often chosen for the development of large-scale magnets because of their high stability. Bi-2212 is presently the only kind of copper oxide superconducting material which can be made into solid round wire, which provides a good basis for developing CICCs. The over pressure (OP) heat treatment can significantly improve the superconducting performance of Bi-2212 wires but it also reduces the wire diameter by ∼5%. This leads to an increase of the void fraction of CICCs, typically from 30% to 40% for a CICC with ITER scale dimensions. A pre-OP heat treatment before OP is proposed in this study. The reduction of the wire diameter can be completed before the formation of the continuous superconducting phase, which would dramatically decrease the CICC void fraction. One Bi-2212 cable consisting of 84 wires, was first pre-OP heat treated successfully and after completing the OP heat treatment, the cable's transport performance was tested. The results showed good performance with a critical current (I c) of 35.7 kA at 5.8 T background field in 4.2 K, which is consistent with the predication