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11 pages, 3118 KiB

Open AccessArticle

Strain Induced Topological Insulator Phase in CsPbBr_xI_3−x (x = 0, 1, 2, and 3) Perovskite: A Theoretical Study

by Jen-Chuan Tung, Yu-Hsuan Hsieh and Po-Liang Liu

Appl. Sci. 2021, 11(12), 5353; https://doi.org/10.3390/app11125353 - 9 Jun 2021

Cited by 7 | Viewed by 2044

Abstract

First-principles density functional theory was used to determine the surface band structures of CsPbBr_xI_3−x (x = 0, 1, 2, and 3) perovskites. The equilibrium lattice constants of CsPbBr_xI_3−x were obtained from the minimum of [...] Read more.

First-principles density functional theory was used to determine the surface band structures of CsPbBr_xI_3−x (x = 0, 1, 2, and 3) perovskites. The equilibrium lattice constants of CsPbBr_xI_3−x were obtained from the minimum of the total energy as a function of the iodine concentration. We discovered that the band gaps of CsPbBr_xI_3−x decreased monotonically under pressure. The phase change from a normal insulator to a topological insulator was found at approximately 2–4 GPa. The Pbp- and Brs-orbitals inverted at the R symmetric point with and without spin–orbit coupling. Nontrivial Z₂ topological numbers were obtained, and the surface conduction bands were demonstrated theoretically using a 1 × 1 × 10 supercell. We ascertained that CsPbBr₂I has the largest electric polarization 0.025 C/m² under a compression strain of 10%. We also observed that in the normal insulation phase, the band gap increases with a small displacement of the central Pb atom in the z-direction, but in the topological insulator phase, the band gap decreases with the movement of the Pb atom in the z-direction. Additionally, in the supercell structure, CsPbBr_xI_3−x is a ferroelectric topological insulator because the Pb atom leaves its own equilibrium position. Full article

(This article belongs to the Special Issue Selected Papers from ISET 2020 and ISPE 2020)

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10 pages, 3078 KiB

Open AccessArticle

Influences of Work Function Changes in NO₂ and H₂S Adsorption on Pd-Doped ZnGa₂O₄(111) Thin Films: First-Principles Studies

by Jen-Chuan Tung, Ding-Yuan Wang, Yu-Hsuan Chen and Po-Liang Liu

Appl. Sci. 2021, 11(11), 5259; https://doi.org/10.3390/app11115259 - 5 Jun 2021

Cited by 7 | Viewed by 2113

Abstract

The work function variations of NO₂ and H₂S molecules on Pd-adsorbed ZnGa₂O₄(111) were calculated using first-principle calculations. For the bonding of a nitrogen atom from a single NO₂ molecule to a Pd atom, the maximum [...] Read more.

The work function variations of NO₂ and H₂S molecules on Pd-adsorbed ZnGa₂O₄(111) were calculated using first-principle calculations. For the bonding of a nitrogen atom from a single NO₂ molecule to a Pd atom, the maximum work function change was +1.37 eV, and for the bonding of two NO₂ molecules to a Pd atom, the maximum work function change was +2.37 eV. For H₂S adsorption, the maximum work function change was reduced from −0.90 eV to −1.82 eV for bonding sulfur atoms from a single and two H₂S molecules to a Pd atom, respectively. Thus, for both NO₂ and H₂S, the work function change increased with an increase in gas concentration, showing that Pd-decorated ZnGa₂O₄(111) is a suitable material in NO₂/H₂S gas detectors. Full article

(This article belongs to the Special Issue Selected Papers from ISET 2020 and ISPE 2020)

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10 pages, 2470 KiB

Open AccessArticle

Microwave Performance, Microstructure, and Crystallization of (Mg_0.6Zn_0.4)_1−yNi_yTiO₃ Ilmenite Ceramics

by Chun-Hsu Shen, Chung-Long Pan, Shih-Hung Lin and Cheng-Che Ho

Appl. Sci. 2021, 11(7), 2952; https://doi.org/10.3390/app11072952 - 25 Mar 2021

Cited by 2 | Viewed by 1421

Abstract

The sintering behavior, microstructure analysis, crystallization, and microwave performance of (Mg_0.6Zn_0.4)_1−yNi_yTiO₃ (y = 0.01–0.2) ceramics, processed with raw powders of MgO, NiO, ZnO, and TiO₂ via the conventional solid-state method, are investigated. The [...] Read more.

The sintering behavior, microstructure analysis, crystallization, and microwave performance of (Mg_0.6Zn_0.4)_1−yNi_yTiO₃ (y = 0.01–0.2) ceramics, processed with raw powders of MgO, NiO, ZnO, and TiO₂ via the conventional solid-state method, are investigated. The main phases of (Mg_0.6Zn_0.4)_1−yNi_yTiO₃ ceramics were obtained. With partial replacement by Ni²⁺, the (Mg_0.6Zn_0.4)_0.95Ni_0.05TiO₃ could be well sintered at 1200 °C, and the microwave performance was shown to be positively correlated with sintering temperature. The permittivity (ε_r) saturated at 18.7–19.3, and the quality factor (Qf) values approached 72,000–165,000 (GHz) as the sintering temperatures increase from 1125 to 1250 °C. The temperature coefficient of resonance frequency (τ_f) falls in a stable range of −62.9 to −66 ppm/°C as sintering temperature rising. A permittivity (ε_r) of 19.3, a maximum Qf value of 165,000 (GHz), and a temperature coefficient (τ_f) of −65.4 ppm/°C were measured for the samples at 1200 °C/4 h. (Mg_0.6Zn_0.4)_0.95Ni_0.05TiO₃ material system shows high potential for applications of high frequency-selection components in satellite communication and 5G wireless telecommunication systems. Full article

(This article belongs to the Special Issue Selected Papers from ISET 2020 and ISPE 2020)

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16 pages, 1544 KiB

Open AccessArticle

Identification of Transcription Factors, Biological Pathways, and Diseases as Mediated by N6-methyladenosine Using Tensor Decomposition-Based Unsupervised Feature Extraction

by Y-h. Taguchi, S. Akila Parvathy Dharshini and M. Michael Gromiha

Appl. Sci. 2021, 11(1), 213; https://doi.org/10.3390/app11010213 - 28 Dec 2020

Cited by 3 | Viewed by 2326

Abstract

N⁶-methyladenosine (m6A) editing is the most common RNA modification known to contribute to various biological processes. Nevertheless, the mechanism by which m6A regulates transcription is unclear. Recently, it was proposed that m6A controls transcription through histone modification, although no comprehensive analysis [...] Read more.

N⁶-methyladenosine (m6A) editing is the most common RNA modification known to contribute to various biological processes. Nevertheless, the mechanism by which m6A regulates transcription is unclear. Recently, it was proposed that m6A controls transcription through histone modification, although no comprehensive analysis using this dataset was performed. In this study, we applied tensor decomposition (TD)-based unsupervised feature extraction (FE) to a dataset composed of mouse embryonic stem cells (mESC) and a human cancer cell line (HEC-1-A) and successfully identified two sets of genes significantly overlapping between humans and mice (63 significantly overlapped genes among a total of 16,763 genes common to the two species). These significantly overlapped genes occupy at most 10% genes from both gene sets. Using these two sets of genes, we identified transcription factors (TFs) that m6A might recruit, biological processes that m6A might contribute to, and diseases that m6A might cause; they also largely overlap with each other. Since they were commonly identified using two independent datasets, the results regarding these TFs, biological processes, and diseases should be highly robust and trustworthy. It will help us to understand the mechanisms by which m6A contributes to biological processes. Full article

(This article belongs to the Special Issue Selected Papers from ISET 2020 and ISPE 2020)

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10 pages, 3879 KiB

Open AccessArticle

Effect of Iron Loading on the Catalytic Activity of Fe/N-Doped Reduced Graphene Oxide Catalysts via Irradiation

by Kazi Rumanna Rahman, Kuan Ying Kok, Wai Yin Wong, Hsiharng Yang and Kean Long Lim

Appl. Sci. 2021, 11(1), 205; https://doi.org/10.3390/app11010205 - 28 Dec 2020

Cited by 8 | Viewed by 2980

Abstract

The aim of this study is to produce noble-metal-free oxygen reduction reaction (ORR) catalyst via irradiation. Gamma ray irradiation reduction has been utilized to produce N-doped reduced graphene oxide (rGO)-supported iron (Fe)-based catalysts, whose weight percent (wt.%) of Fe loading varies from 10% [...] Read more.

The aim of this study is to produce noble-metal-free oxygen reduction reaction (ORR) catalyst via irradiation. Gamma ray irradiation reduction has been utilized to produce N-doped reduced graphene oxide (rGO)-supported iron (Fe)-based catalysts, whose weight percent (wt.%) of Fe loading varies from 10% to 20%. In this study, the physicochemical properties of Fe/N-rGO with various loadings of Fe (10 wt.%, 15 wt.% and 20 wt.%) were explored through X-ray diffraction (XRD), field emission scanning electron microscopy-energy dispersive spectroscopy (FESEM-EDS), Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR). XRD showed that a broad-peak nanocrystallite Fe₂O₃ phase formed. Raman spectroscopy revealed that Fe insertion increased the disordered GO structure. Fourier transform infrared (FTIR) demonstrated that N was functionalized into rGO. FESEM-EDX presented that Fe nanoparticles existed on the wrinkled rGO surface but their amount was low. Linear sweep voltammetry (LSV) was performed with a rotating disk electrode in 0.1 M KOH at a scanning rate of 20 mVs⁻¹ and revolution rates of 400, 900 and 1600 rpm and the corresponding electron transfer numbers were investigated with a Koutecky–Levich model. This model indicated that the number of electron transfers of 20% Fe/N-rGO was above 2 and its performance toward ORR was higher than those of 10% Fe/N-rGO and 15% Fe/N-rGO. Full article

(This article belongs to the Special Issue Selected Papers from ISET 2020 and ISPE 2020)

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8 pages, 1524 KiB

Open AccessArticle

Effect of Nitrogen on the Growth of (100)-, (110)-, and (111)-Oriented Diamond Films

by Jen-Chuan Tung, Tsung-Che Li, Yen-Jui Teseng and Po-Liang Liu

Appl. Sci. 2021, 11(1), 126; https://doi.org/10.3390/app11010126 - 24 Dec 2020

Cited by 6 | Viewed by 2101

Abstract

The aim of this research is the study of hydrogen abstraction reactions and methyl adsorption reactions on the surfaces of (100), (110), and (111) oriented nitrogen-doped diamond through first-principles density-functional calculations. The three steps of the growth mechanism for diamond thin films are [...] Read more.

The aim of this research is the study of hydrogen abstraction reactions and methyl adsorption reactions on the surfaces of (100), (110), and (111) oriented nitrogen-doped diamond through first-principles density-functional calculations. The three steps of the growth mechanism for diamond thin films are hydrogen abstraction from the diamond surface, methyl adsorption on the diamond surface, and hydrogen abstraction from the methylated diamond surface. The activation energies for hydrogen abstraction from the surface of nitrogen-undoped and nitrogen-doped diamond (111) films were −0.64 and −2.95 eV, respectively. The results revealed that nitrogen substitution was beneficial for hydrogen abstraction and the subsequent adsorption of methyl molecules on the diamond (111) surface. The adsorption energy for methyl molecules on the diamond surface was generated during the growth of (100)-, (110)-, and (111)-oriented diamond films. Compared with nitrogen-doped diamond (100) films, adsorption energies for methyl molecule adsorption were by 0.14 and 0.69 eV higher for diamond (111) and (110) films, respectively. Moreover, compared with methylated diamond (100), the activation energies for hydrogen abstraction were by 0.36 and 1.25 eV higher from the surfaces of diamond (111) and (110), respectively. Growth mechanism simulations confirmed that nitrogen-doped diamond (100) films were preferred, which was in agreement with the experimental and theoretical observations of diamond film growth. Full article

(This article belongs to the Special Issue Selected Papers from ISET 2020 and ISPE 2020)

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8 pages, 2045 KiB

Open AccessArticle

InGaN Resonant-Cavity Light-Emitting Diodes with Porous and Dielectric Reflectors

by Cheng-Jie Wang, Ying Ke, Guo-Yi Shiu, Yi-Yun Chen, Yung-Sen Lin, Hsiang Chen and Chia-Feng Lin

Appl. Sci. 2021, 11(1), 8; https://doi.org/10.3390/app11010008 - 22 Dec 2020

Cited by 21 | Viewed by 3148

Abstract

InGaN based resonant-cavity light-emitting diode (RC-LED) structures with an embedded porous-GaN/n-GaN distributed Bragg reflector (DBR) and a top dielectric Ta₂O₅/SiO₂ DBR were demonstrated. GaN:Si epitaxial layers with high Si-doping concentration (n⁺-GaN:Si) in the 20-period n⁺ [...] Read more.

InGaN based resonant-cavity light-emitting diode (RC-LED) structures with an embedded porous-GaN/n-GaN distributed Bragg reflector (DBR) and a top dielectric Ta₂O₅/SiO₂ DBR were demonstrated. GaN:Si epitaxial layers with high Si-doping concentration (n⁺-GaN:Si) in the 20-period n⁺-GaN/n-GaN stacked structure were transformed into a porous-GaN/n-GaN DBR structure through the doping-selective electrochemical wet etching process. The central wavelength and reflectivity were measured to be 434.3 nm and 98.5% for the porous DBR and to be 421.3 nm and 98.1% for the dielectric DBR. The effective 1λ cavity length at 432nm in the InGaN resonant-cavity consisted of a 30 nm-thick Ta₂O₅ spacer and a 148 nm-thick InGaN active layer that was analyzed from the angle-resolved photoluminescence (PL) spectra. In the optical pumping PL spectra, non-linear emission intensity and linewidths reducing effect, from 6.5 nm to 0.7 nm, were observed by varying the laser pumping power. Directional emission pattern and narrow linewidth were observed in the InGaN active layer with bottom porous DBR, top dielectric DBR, and the optimum spacer layer to match the short cavity structure. Full article

(This article belongs to the Special Issue Selected Papers from ISET 2020 and ISPE 2020)

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27 pages, 20675 KiB

Open AccessArticle

Research on Vehicle Trajectory Prediction and Warning Based on Mixed Neural Networks

by Chih-Hsiung Shen and Ting-Jui Hsu

Appl. Sci. 2021, 11(1), 7; https://doi.org/10.3390/app11010007 - 22 Dec 2020

Cited by 8 | Viewed by 2902

Abstract

When driving on roads, the most important issue for driving is safety. There are various vehicles, including cars, motorcycles, bicycles, and pedestrians, that increase the complexity of road conditions and the burden on drivers. In order to improve driving safety, a deep learning [...] Read more.

When driving on roads, the most important issue for driving is safety. There are various vehicles, including cars, motorcycles, bicycles, and pedestrians, that increase the complexity of road conditions and the burden on drivers. In order to improve driving safety, a deep learning framework is applied to predict and announce the trajectory of a car. This research is divided into three parts. Lane line detection is adopted first. Secondly, car object detection is employed. Lastly, car trajectory prediction is a key part of our research. In addition, real images and videos in the driving recorder are used to simulate the real situation the driver sees from the driver’s seat. Car detection is utilized to obtain the coordinates of the car in these images, reaching an accuracy of 0.91 and then predicting the future trajectory of the car, obtaining a loss of 0.00024 and costing 12 milliseconds. It can precisely mark the position of the car, accurately detect the lane line, and predict the future car’s trajectory. Through the prediction and announcement of the car trajectory, we verified that our model can correctly predict the car trajectory and truly enhance the safety of driving. Full article

(This article belongs to the Special Issue Selected Papers from ISET 2020 and ISPE 2020)

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10 pages, 2070 KiB

Open AccessArticle

Quantitative Ultrasound Texture Analysis to Assess the Spastic Muscles in Stroke Patients

by Peng-Ta Liu, Ta-Sen Wei and Congo Tak-Shing Ching

Appl. Sci. 2021, 11(1), 11; https://doi.org/10.3390/app11010011 - 22 Dec 2020

Cited by 8 | Viewed by 2113

Abstract

This study aimed to investigate the feasibility of sonoelastography for determining echotexture in post-stroke patients. Moreover, the relationships of muscle echotexture features, muscle stiffness, and functional performance in spastic muscle were explored. The study population comprised 22 males with stroke. The echotexture features [...] Read more.

This study aimed to investigate the feasibility of sonoelastography for determining echotexture in post-stroke patients. Moreover, the relationships of muscle echotexture features, muscle stiffness, and functional performance in spastic muscle were explored. The study population comprised 22 males with stroke. The echotexture features (entropy and energy) of the biceps brachii muscles (BBM) in both arms were extracted by local binary pattern (LBP) from ultrasound images, whereas the stiffness of BBM was assessed by shear wave velocity (SWV) in the transverse and longitudinal planes. The Fugl–Meyer assessment (FMA) was used to assess the functional performance of the upper arm. The results showed that echotexture was more inhomogeneous in the paretic BBM than in the non-paretic BBM. SWV was significantly faster in paretic BBM than in non-paretic BBM. Both echotexture features were significantly correlated with SWV in the longitudinal plane. The feature of energy was significantly negatively correlated with FMA in the longitudinal plane and was significantly positively correlated with the duration from stroke onset in the transverse plane. The echotexture extracted by LBP may be a promising approach for quantitative assessment of the spastic BBM in post-stroke patients. Full article

(This article belongs to the Special Issue Selected Papers from ISET 2020 and ISPE 2020)

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9 pages, 2624 KiB

Open AccessArticle

Intermediate Band Studies of Substitutional V²⁺, Cr²⁺, and Mn²⁺ Defects in ZnTe Alloys

by Jen-Chuan Tung, Bang-Wun Lin and Po-Liang Liu

Appl. Sci. 2020, 10(24), 8937; https://doi.org/10.3390/app10248937 - 15 Dec 2020

Cited by 2 | Viewed by 1617

Abstract

We present first-principles total-energy density functional calculations to study the intermediate band states of substitutional V²⁺, Cr²⁺, and Mn²⁺ ions in ZnTe alloys. The intermediate band states of substitutional transition metal defects of TM²⁺_xZn₁₋ [...] Read more.

We present first-principles total-energy density functional calculations to study the intermediate band states of substitutional V²⁺, Cr²⁺, and Mn²⁺ ions in ZnTe alloys. The intermediate band states of substitutional transition metal defects of TM²⁺_xZn_1−xTe (TM = V, Cr, Mn) alloys are examined as their atomic, structural, and electronic analysis. Our findings show that the scissor-corrected transitions due to Jahn-Teller effects lead to the wavelengths 2530 nm and 2695 nm in the emission spectra. Our findings agree with previously reported experimental results. Full article

(This article belongs to the Special Issue Selected Papers from ISET 2020 and ISPE 2020)

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18 pages, 30276 KiB

Open AccessArticle

Study on Electromigration Effects and IMC Formation on Cu–Sn Films Due to Current Stress and Temperature

by Zhao-Ying Wang, Nhat Minh Dang, Po-Hsun Wang, Terry Yuan-Fang Chen and Ming-Tzer Lin

Appl. Sci. 2020, 10(24), 8893; https://doi.org/10.3390/app10248893 - 13 Dec 2020

Cited by 5 | Viewed by 2165

Abstract

In this study, the effects of electromigration on a solder/copper substrate due to temperature and current density stress were investigated. The copper–tin (Cu–Sn) film samples were subjected under a fixed current and various heating conditions (130 °C and 180 °C) and current densities [...] Read more.

In this study, the effects of electromigration on a solder/copper substrate due to temperature and current density stress were investigated. The copper–tin (Cu–Sn) film samples were subjected under a fixed current and various heating conditions (130 °C and 180 °C) and current densities (different cross-sectional areas). The micro-structural changes and intermetallic compound (IMC) formation were observed, and failure phenomena (brittle cracks, voids, bumps, etc.) on the structures of samples were discussed. The results showed that the IMC thickness increased as the temperature and current density increased. Moreover, it was found that the higher the temperature and current density was, the greater the defects that were observed. By adjusting the designs of sample structures, the stress from the current density can be decreased, resulting in reduced failure phenomena, such as signal delay, distortion, and short circuiting after long-term use of the material components. A detailed IMC growth mechanism and defect formation were also closely studied and discussed. Full article

(This article belongs to the Special Issue Selected Papers from ISET 2020 and ISPE 2020)

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8 pages, 3390 KiB

Open AccessArticle

Adsorption of NO₂ and H₂S on ZnGa₂O₄(111) Thin Films: A First-Principles Density Functional Theory Study

by Jen-Chuan Tung, Yi-Hung Chiang, Ding-Yuan Wang and Po-Liang Liu

Appl. Sci. 2020, 10(24), 8822; https://doi.org/10.3390/app10248822 - 9 Dec 2020

Cited by 10 | Viewed by 1715

Abstract

We performed first-principles total-energy density functional calculations to study the reactions of NO₂ and H₂S molecules on Ga–Zn–O-terminated ZnGa₂O₄(111) surfaces. The adsorption reaction and work functions of eight NO₂ and H₂S adsorption models [...] Read more.

We performed first-principles total-energy density functional calculations to study the reactions of NO₂ and H₂S molecules on Ga–Zn–O-terminated ZnGa₂O₄(111) surfaces. The adsorption reaction and work functions of eight NO₂ and H₂S adsorption models were examined. The bonding of the nitrogen atom from a single NO₂ molecule to the Ga atom of the Ga–Zn–O-terminated ZnGa₂O₄(111) surfaces exhibited a maximum work function change of +0.97 eV. The bond joining the sulfur atom from a single H₂S molecule and the Ga atom of Ga–Zn–O-terminated ZnGa₂O₄(111) surfaces exhibited a maximum work function change of −1.66 eV. Both results concur with previously reported experimental observations for ZnGa₂O₄-based gas sensors. Full article

(This article belongs to the Special Issue Selected Papers from ISET 2020 and ISPE 2020)

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8 pages, 2904 KiB

Open AccessArticle

New Ternary Compounds of the Composition Cu₂SnTi₃ and Their Crystal Structures

by Sheng-Fang Huang, Yen-Cheng Chang and Po-Liang Liu

Appl. Sci. 2020, 10(24), 8776; https://doi.org/10.3390/app10248776 - 8 Dec 2020

Viewed by 1533

Abstract

A new ternary compound Cu₂SnTi₃ has been synthesized by vacuum sintering at 900 °C. The atomic structures of CaCu₅- and InNi₂-like Cu₂SnTi₃ are calculated using density functional theory methods. The X-ray diffraction (XRD) [...] Read more.

A new ternary compound Cu₂SnTi₃ has been synthesized by vacuum sintering at 900 °C. The atomic structures of CaCu₅- and InNi₂-like Cu₂SnTi₃ are calculated using density functional theory methods. The X-ray diffraction (XRD) analysis and selected area diffraction (SAD) patterns of the new ternary compound Cu₂SnTi₃ are considered to verify the atomic structures of CaCu₅- and InNi₂-like Cu₂SnTi₃. The results reveal that the InNi₂-like Cu₂SnTi₃ model has the lowest total energy of −35.239 eV, representing the trigonal crystal structure. The orthorhombic crystal structure of the CaCu₅-like Cu₂SnTi₃ model has the second lowest total energy of −33.926 eV. Our theoretical X-ray diffraction peak profiles of InNi₂-like (CaCu₅-like) Cu₂SnTi₃ are nearly identical to experimental one, leading to an error below 2.0% (3.0%). In addition, the hexagonal crystal structure of the CaCu₅-like Cu₂SnTi₃ model has the highest total energy of −33.094 eV. The stability of the Cu₂SnTi₃ in terms of energy follows the order: the trigonal, orthorhombic, and hexagonal crystal structure. Full article

(This article belongs to the Special Issue Selected Papers from ISET 2020 and ISPE 2020)

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12 pages, 3198 KiB

Open AccessArticle

Synthesis and Application in Cell Imaging of Acridone Derivatives

by Yung-Chieh Chan, Chia-Ying Li, Chin-Wei Lai, Min-Wei Wu, Hao-Jui Tseng and Cheng-Chung Chang

Appl. Sci. 2020, 10(23), 8708; https://doi.org/10.3390/app10238708 - 4 Dec 2020

Cited by 4 | Viewed by 2613

Abstract

Tricyclic acridone derivatives have been extensively developed as antimicrobial, antimalarial, and antitumor drugs due to their broad spectrum of drug design and biological activity. In this study, we developed a surfactant-like acridone scaffold that contained two vinylpyridines and a dodecyl pyridine chain. The [...] Read more.

Tricyclic acridone derivatives have been extensively developed as antimicrobial, antimalarial, and antitumor drugs due to their broad spectrum of drug design and biological activity. In this study, we developed a surfactant-like acridone scaffold that contained two vinylpyridines and a dodecyl pyridine chain. The acridone scaffold decorated the dodecyl pyridine chain by N-bromosuccinimide reagent. The surfactant-like core scaffold incorporated with 4-vinylpyridines at the 2- and 7-positions via a Heck coupling reaction. Subsequently, the acridone derivatives were methylated onto these pyridine groups. Here we developed two similar acridone derivatives, MedAcd12C and MedAcd12P. The MedAcd12C incorporated two pyridine groups, and MedAcd12P incorporated three pyridine groups. MedAcd12C and MedAcd12P have two identical vinylpyridines and the different anchor tails at the N10 position. Their physicochemical properties, cell compatibility, and photoluminescence were demonstrated. Although both compounds have no fluorescence emission in water solution, MedAcd12P and MedAcd12C significantly appeared with orange light emission in the cellular imaging. We suggested that the surfactant-like scaffold promoted the drugs’ self-assembly and caused the aggregation-induced emission (AIE) after cellular uptake. This innovative design endowed acridone derivatives with an AIE and traceability for cell imaging. Full article

(This article belongs to the Special Issue Selected Papers from ISET 2020 and ISPE 2020)

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12 pages, 2027 KiB

Open AccessArticle

Parameters Adjustment Optimization for Prepreg of Copper Clad Laminate Based on Virtual Metrology

by Yiyo Kuo and Ssu-Han Chen

Appl. Sci. 2020, 10(23), 8488; https://doi.org/10.3390/app10238488 - 27 Nov 2020

Cited by 2 | Viewed by 1807

Abstract

In this research, virtual metrology models, which can estimate the quality characteristics based on the given manufacturing parameters, were developed by lasso regression and support vector regression. Then, the virtual metrology (VM) models were integrated into a mathematical model to minimize the adjustment [...] Read more.

In this research, virtual metrology models, which can estimate the quality characteristics based on the given manufacturing parameters, were developed by lasso regression and support vector regression. Then, the virtual metrology (VM) models were integrated into a mathematical model to minimize the adjustment of manufacturing parameters and ensure the corresponding quality characteristics that would meet the customers’ needs. According to the results of the experiment, it was found that developing the virtual metrology model by using integration of lasso regression and support vector regression and taking second order terms into consideration produces the best performance for estimating the quality characteristics. Moreover, the integrated mathematical model can provide manufacturing parameters that minimize the amount of adjustment and ensure that the quality characteristics equal their corresponding target values. The proposed methodology can reduce the setup times and consequently increase productivity. Full article

(This article belongs to the Special Issue Selected Papers from ISET 2020 and ISPE 2020)

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27 pages, 3147 KiB

Open AccessReview

Mini-Review: Recent Technologies of Electrode and System in the Enzymatic Biofuel Cell (EBFC)

by Nabila A. Karim and Hsiharng Yang

Appl. Sci. 2021, 11(11), 5197; https://doi.org/10.3390/app11115197 - 3 Jun 2021

Cited by 17 | Viewed by 2915

Abstract

Enzymatic biofuel cells (EBFCs) is one of the branches of fuel cells that can provide high potential for various applications. However, EBFC has challenges in improving the performance power output. Exploring electrode materials is one way to increase enzyme utilization and lead to [...] Read more.

Enzymatic biofuel cells (EBFCs) is one of the branches of fuel cells that can provide high potential for various applications. However, EBFC has challenges in improving the performance power output. Exploring electrode materials is one way to increase enzyme utilization and lead to a high conversion rate so that efficient enzyme loading on the electrode surface can function correctly. This paper briefly presents recent technologies developed to improve bio-catalytic properties, biocompatibility, biodegradability, implantability, and mechanical flexibility in EBFCs. Among the combinations of materials that can be studied and are interesting because of their properties, there are various nanoparticles, carbon-based materials, and conductive polymers; all three have the advantages of chemical stability and enhanced electron transfer. The methods to immobilize enzymes, and support and substrate issues are also covered in this paper. In addition, the EBFC system is also explored and developed as suitable for applications such as self-pumping and microfluidic EBFC. Full article

(This article belongs to the Special Issue Selected Papers from ISET 2020 and ISPE 2020)

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