bluuebunny/crossref_metadata_2025 huggingface dataset:
Substitutional Carbon Incorporation in SiGeC/Si Heterostructures: Influence of Silicon Precursors
Authors: Vives Jérémy , Deprat Fabien , Dutartre Didier , Lespiaux Justine , Duru Romain , Bicer Mehmet , Drogue Nathalie , Juhel Marc , Chaussende Didier
Published: September 2022

In this paper, SiGe or SiGeC epitaxy with Silane or Disilane, Germane and Methylsilane precursors was studied in a 300 mm industrial Reduced Pressure-Chemical Vapor Deposition (RP-CVD) reactor. The SiGe growth rate exponentially increased with the temperature in the 500 °C - 600 °C range for both silicon precursors (activation energy Ea = 2.1 eV). It was, at 550 °C, almost twice higher with Si2H6 than with SiH4. At low temperature, Si2H6 is indeed more reactive than SiH4, resulting in SiGe growth rates significantly higher for a given germanium composition. Then, carbon incorporation at 550 °C into Si0.8Ge0.2 was studied. The higher reactivity of Si2H6 compared to SiH4 resulted in a better substitutional carbon incorporation. In our experimental conditions, 1.2 at% of fully substitutional carbon atoms could indeed be obtained with Si2H6 (without any detectable interstitial ones). Meanwhile, only 0.5 at% of fully substitutional carbon atoms was obtained with SiH4.
Lateral Selective SiGe Growth for Dislocation-Free Virtual Substrate Fabrication
Authors: Anand Ketan , Schubert Markus Andreas , Corley-Wiciak Agnieszka Anna , Spirito Davide , Corley-Wiciak Cedric , Klesse Wolfgang Matthias , Mai Andreas , Tillack Bernd , Yamamoto Yuji
Published: September 2022

Dislocation free local SiGe-on-insulator virtual substrate is fabricated using lateral selective SiGe growth by reduced pressure chemical vapor deposition. The lateral selective SiGe growth is performed around ~1.25 µm square Si (001) pillar in a cavity formed by HCl vapor phase etching of Si at 850 °C from side of SiO2 / Si mesa structure on buried oxide. Smooth root mean square roughness of SiGe surface of 0.14 nm, which is determined by interface roughness between the sacrificially etched Si and the SiO2 cap, is obtained. Uniform Ge content of ~40% in the laterally grown SiGe is observed. In the Si pillar, tensile strain of ~0.65% is found which could be due to thermal expansion difference between SiO2 and Si. In the SiGe, tensile strain of ~1.4% along <010> direction, which is higher compared to that along <110> direction, is observed. The tensile strain is induced from both [110] and [-110] directions. Threading dislocations in the SiGe are located only ~400 nm from Si pillar and stacking faults are running towards <110> directions, resulting in wide dislocation-free area formation in SiGe along <010> due to horizontal aspect ratio trapping.
Ge Nano-Heteroepitaxy: From Nano-Pillars to Thick Coalesced Layers
Authors: Mastari Marouane , Charles Matthew , Pimenta-Barros Patricia , Argoud Maxime , Tiron Raluca , Papon Anne-Marie , Chevalier Nicolas , Hartmann Jean-Michel , Landru Didier , Kim Young-Pil , Kononchuk Oleg
Published: September 2022

Ge epitaxy on nanometer-size Ge pillars was studied in a 300 mm industrial Reduced Pressure-Chemical Vapour Deposition tool. A patterning scheme based on diblock copolymer lithography was used to fabricate honeycombed nanometer-sized Si templates for the hetero-epitaxy of Ge nano-pillars. It was highly selective and uniform at 600°C. Thick Ge layers were then grown with a low temperature/high temperature approach on Ge nano-pillars and characterized by Atomic Force Microscopy, X-Ray Diffraction and cross-sectional Transmission Electron Microscopy. A degraded surface morphology, with otherwise similar structural properties was obtained for 2D Ge layers grown on Ge nano-pillars compared to growth on bulk Si. Defects such as stacking faults and twins also formed during the coalescence process.
Characterization of Light Emission Properties of Impurity Doped Ge/Si Core–Shell Quantum Dots
Authors: Miyazaki Seiichi , Imai Yuki , Makihara Katsunori
Published: September 2022

We have fabricated valency-controlled Si-QDs with Ge-core with an areal density as high as ~1011 cm-2 on ultrathin SiO2 and studied the effect of phosphorus- and boron-doping on Ge-core from their PL properties. During the Ge deposition, delta doping of phosphorus or boron atoms in QDs was carried out by pulse injection using 1% PH3 or B2H6 diluted with He, respectively. No changes in dot size and density with either P- or B-doping were confirmed by AFM topographic images. Under photoexcitation of undoped QDs with a 976-nm line from a semiconductor laser, broad PL spectra consisting of four Gaussian components originating from radiative recombination through quantized states in QDs were observed in the energy range from 0.62 to 0.85 eV without impurity doping even at room temperature. In the doped QDs, relatively-narrow components peaked at ~0.68 eV and ~0.64eV were observed with P-doping and with B-doping to Ge-core, respectively, in addition to the four components seen in undoped QDs. It is interesting noted that, with an increase in B2H6 pulse injection from 1 to 4 times, the integrated PL intensity was enhanced by a factor of 1.4 to 2.4 compared to that of the undoped QDs while no significant change in spectral shape was observable. This can be interpreted in terms of an increase in the number of holes with B-doping to the Ge core since the carrier recombination rates is proportional to the product of the number of electrons and holes confined in QD under weak photoexcitation.
(Invited) Achieving High-Power Single-Mode Operation in Vertical-Cavity Surface-Emitting Lasers Via Scalable, Higher-Order Mode Suppression Techniques
Authors: Dallesasse John Michael , Su Patrick , Pikul Kevin Peter , Espenhahn Leah , Kraman Mark
Published: September 2022

Achieving high-power single-mode operation in Vertical-Cavity Surface-Emitting Lasers (VCSELs) has received renewed interest due to performance needs driven by facial recognition and 3D imaging in mobile telephones. Two distinct mode control methods that rely on exploiting the spatial field distribution of optical transverse modes to achieve high-power single-mode operation in VCSELs will be discussed. The first method uses a surface-deposited optical coating of multilayer SiO2/TiO2 or single-layer silicon to achieve single-mode emission. The capability to pattern these layers in a wafer-scale process makes this method attractive for high-volume manufacturing. The second method utilizes impurity-induced layer disordering (IID) to selectively intermix the top distributed Bragg reflector (DBR) in a VCSEL, thereby creating a mirror whose reflectivity spatially varies across the aperture. Using these techniques, single-mode output power in excess of 10 mW has been demonstrated with side-mode suppression ratios in excess of 35 db.
Process Development of Amorphous Indium Tin Gallium Oxide (ITGO) Thin Film Transistors
Authors: Powell Eli , Kabir Muhammad Salahuddin , Zhu Bin , Manley Robert G. , Hirschman Karl D.
Published: September 2022

The focus of this study is an investigation on Indium-Tin-Gallium-Oxide (ITGO) TFTs. Unpassivated bottom-gate devices werefabricated with a sputter-deposited 30nm a-ITGO film with 1% and10% oxygen gas ambient, followed by a 1 or 2 hour anneal at 300oCin oxygen. Devices fabricated with PO2 = 1% resulted in a highlyconductive channel, whereas devices with PO2 = 10% displayedsemiconducting behavior and a shallow subthreshold. Followingaging in room ambient for multiple days, devices displayed left-shifted transfer characteristics with steep subthreshold. It ishypothesized that the unpassivated back-channel attains a morehomogeneous trap distribution. The ITGO devices demonstrate aneffective channel mobility approximately 2.5 times higher thanIGZO TFTs. Radial variation in device performance can beattributed to non-uniformities in the as-deposited ITGO film, with acorrelation to the distribution in optical constants across the wafer.
Electrical Performance Enhancement of Fully Solution-processed Amorphous In-Zn-O Thin-Film Transistor via Argon Plasma Treatment
Authors: Hanifah Umu , Bermundo Juan Paolo , Uenuma Mutsunori , Uraoka Yukiharu
Published: September 2022

This work aims to improve the electrical performance of fully solution processed oxide TFT by applying Argon plasma treatment. In this work, we successfully fabricated fully solution processed amorphous Indium Zinc Oxide thin-film (a-IZO) thin-film transistor (TFT). Before performing the plasma treatment, the electrode of the samples is still inactivated. Argon plasma treatment can activate the electrode and induce TFT switching. The electrical performance of a-IZO TFT was enhanced by varying Argon gas flow rate (50, 75, and 100 sccm) for 5 s. As a result, high mobility of up to 31.12 cm2/Vs was achieved by 75 sccm Argon plasma treatment. These results show that performance enhancement of fully-solution processed a-IZO TFT by plasma treatment has a large potential for future low-temperature flexible device applications.
The Effect of a Copolymer Interfacial Layer on the Performance of Organic Thin-Film Transistors
Authors: Tarekegn Eyob Negussie , Seyedi Mastooreh , Luzinov Igor , Harrell William R.
Published: September 2022

The effects of adding a copolymer interfacial layer on the performance of Poly (3-hexylthiophene-2, 5-diyl) (P3HT) based organic thin-film transistors (OTFT) were investigated. Poly (oligo (ethylene glycol) methyl ether methacrylate- glycidyl methacrylate- lauryl methacrylate), which is referred to as POGL, was used as an interfacial layer between P3HT and the dielectric. OTFTs with and without a POGL interfacial layer were fabricated. The field-effect mobility and the threshold voltage were extracted for all the devices. The OTFTs with a POGL interfacial layer were observed to have a smaller threshold voltage than the OTFTs without an interfacial layer, which makes the POGL devices attractive for low power applications. The POGL OTFTs were also observed to have much more ideal drain current saturation characteristics with very small I-V curve slope. This is explained by the deep trap states on the POGL surface and the reduction of the contact resistance at the electrode/organic semiconductor interface. However, the POGL OTFTs were observed to have a smaller drain current and a slightly smaller mobility than the non-POGL OTFTs. This is explained by the surface roughness of the POGL, which affects the charge transport in the channel of the device.
(Invited) Progressive Involvement of Thin Film Technologies in Connected Objects to Meet New Societal Challenges
Authors: Bonnaud Olivier
Published: September 2022

This paper is part of a context of galloping evolution of digitalization of all societal areas. This invasion of digital systems and communication that may appear as a progress in many societal applications, as well create new limitations that must be quickly overcome. These limitations may have scientific, technical and technological origin, but also of a human origin, particularly with regard to the nature and the pool of skills, know-how, and innovation capabilities. This paper highlights the future challenges related to the exponential development of connected objects, and Internet of Things that leads to an effective power consumption growing exponentially as well. The different approaches to meet the challenges emphasize the role of microelectronics devices and systems and the potential interest of thin film technologies. It concludes with the human challenge, which is becoming a key point for the success of the digital extension at the global level.
(Invited, Digital Presentation) Heterogeneous IGZO/Si CFET Monolithic 3D Integration
Authors: Lee Yao-Jen , Chang Shu-Wei , Lee Wen-Hsi , Wang Yeong-Her
Published: September 2022

System-on-panel and monolithic 3D integration must be the main trend in the future. Heterogeneous channel materials need to be integrated on a chip for the different requirements. In the previous work, we innovated an advanced process to combine double gate IGZO high-frequency device and dual work function gate heterogeneous IGZO/Si CFET inverter/SRAM on a substrate. However, the heterogeneous CFET architecture is pretty complicated. Subsequently, the channel design, gate structure, and operation mode for both bottom polysilicon and top IGZO transistor are discussed in detail in this study.
(Digital Presentation) Scalable Growth of Transition Metal Dichalcogenides for Next-Generation Nanoelectronics
Authors: Tong Shi Wun , Ng Man-Fai
Published: September 2022

Atomically-thin semiconducting transitional metal dichalcogenides (TMDCs) are promising channel materials for future ultra-scaled electronic devices due to their high electron mobility attained at sub-nanometer thickness. In particular, monolayer WS2 has shown the highest theoretical room temperature electron mobility among other semiconducting TMDCs as a result of its low effective mass. However, it is still challenging to grow large-area and strictly monolayer WS2 through the conventional chemical vapor deposition (CVD) due to the uncontrollable growth kinetics. In this work, we provide a modified CVD process to prepare the uniform and large-area monolayer TMDCs. Theoretical simulations were performed to understand the fundamental thermodynamically mechanism of the monolayer growth. The property-variation in TMDCs due to difference in electronic structure between different layers of TMDCs can be significantly reduced based on this new approach. This poses a reliable route for the scalable growth of monolayer TMDCs, which is essential for their reliable applications in nanoelectronic devices.
(Invited) Development of 3-inch AlN Single Crystal Substrates
Authors: Bondokov Robert T , Hogan Kasey , Norbury Griffin Q. , Mark Justin , Branagan Sean P. , Ishigami Naoki , Grandusky James , Chen Jianfeng (Jeff)
Published: September 2022

Aluminum nitride (AlN) substrates with diameter of 2-inch are available at large quantities. The further commercialization of the AlN as a substrate for the ultra-wide bandgap (UWBG) electronics depends on its size (≥ 100 mm), cost, and substrate properties. We developed a method based on the Physical Vapor Transport (PVT) capable of growing large AlN bulk crystals. The resulting AlN substrate diameter was increased from 2-inch to 3-inch. The 3-inch AlN is viewed as intermediate phase for realization of 100 mm AlN. The 3-inch AlN substrate exhibit very good crystallinity and excellent UV transparency.
Cost-Effective Formation of Ti/Ni/Ti/Au Ohmic Contacts to n-type SiC Using SiO2 Encapsulation Layer during Phosphorous Implant Activation
Authors: Shimbori Atsushi , Huang Alex Q.
Published: September 2022

The purpose of this research is to develop a cost-effective formation of ohmic contacts to n-type SiC through ion implantation and activation. Although Nitrogen is commonly used as an n-type dopant, especially for in-situ doping during epitaxial growth, Phosphorus was chosen because of its higher solubility limit in SiC materials. Consequently, Phosphorus can achieve selective doping at much higher concentrations (above 1020 cm-3), which will be beneficial in regions such as source/drain and cathode where low contact resistance is needed. After ion implantation, the dopants must be thermally activated, and crystal damage must be recovered through annealing at high temperature between 1400~1700°C. During this stage, the material used as the cap layer will have a notable impact on the morphology and structure of the material. The proposed ohmic metal stacks and SiO2 encapsulation enable cost-effective formation of ohmic contacts to n-type SiC where complex fabrication equipment setup is unavailable.
(Digital Presentation) Effect of the Hydrophilic Layer in Double Microporous Layer Coated Gas Diffusion Layer on PEFC Performance
Authors: Wang Peng , Nakajima Hironori , Kitahara Tatsumi
Published: September 2022

Water management is always one of the main problems of polymer electrolyte fuel cells performance enhancement because it dramatically influences oxygen transport resistance. Typically, the MPL coated GDL with strong hydrophobicity effectively prevents flooding between the catalyst layer and the MPL. To further improve PEFC performance, directly coating an extra hydrophilic MPL on the hydrophobic MPL coated GDL as double MPL can further promote performance. The double MPL using Nafion binder cannot provide enough hydrophilicity to lower the oxygen transport resistance. Combining utilization of the Nafion and TiO2 is efficacious in decreasing the breakthrough pressure and contact angle and ameliorating water drainage from the MEA so that the gas transport ability can be improved. Besides, the appropriate thickness of the double MPL was investigated to better design the double MPL coated GDL.
Molecular Dynamics Simulation of Scattering and Surface Diffusion of Oxygen Molecules on Ionomers in Catalyst Layers of PEFCs
Authors: Hori Tomoki , Mabuchi Takuya , Kinefuchi Ikuya , Tokumasu Takashi
Published: September 2022

We analyzed the influence of the interaction between oxygen molecules and ionomer surfaces on the overall oxygen transport in the catalyst layer of polymer electrolyte fuel cells using a Monte Carlo (MC) method and the molecular dynamics (MD) method. We analyzed how gas–surface interaction parameters of oxygen molecules on the ionomer surface affects the overall transport by the MC method, and found that the conditions of surface diffusion affect much on the overall transport properties. We analyzed how oxygen molecules colliding with the ionomer surface behave using the MD method. When the results were compared, it was found that the ease of movement in the surface diffusion greatly affects the overall transport. We obtained the results of the residence time of the oxygen molecules on the ionomer surface. Moreover, it was suggested that further analysis on the behavior of oxygen molecules on the ionomer surface is necessary in order to more accurately calculate the overall oxygen transport in the catalyst layer.
Operando Cerium Distribution Analysis on Through-Plane Membrane Electrode Assemblies in 2nd-Generation MIRAI
Authors: Orikasa Yuki , Takezawa Aika , Amemiya Kazuki , Tsuji Yoichiro , Asaoka Takahiko , Ohki Maria , Sekizawa Oki , Nitta Kiyofumi
Published: September 2022

Cerium species are added into membrane electrode assemblies (MEAs) of polymer electrolyte fuel cells. They act as radical quenchers that suppress the degradation caused by radical species, which are derived from the reaction between impurity and hydrogen peroxide formed during a fuel cell operation. During long-term operation, the radical quencher (i.e., dissolved trivalent cerium ions) moves toward the cathode electrolyte interface, which affects negatively the durability of the fuel cell. Therefore, it is necessary to observe directly the transport phenomena of cerium species under operating conditions of fuel cells. Operando analysis of cerium distribution with through-plane in MEA has been challenging due to the narrow thickness of electrolyte membranes. In this study, we developed a technique for cerium ion mapping with through-plane MEA under typical fuel cell operation using high-energy micro-beam X-ray fluorescence spectroscopy. The technique was applied in the analysis of the transport phenomena of radical quenchers with through-plane MEA in 2nd-generation MIRAI fuel cells.
3D Visualization of Liquid Water in Catalyst Layer Using X-Ray CT
Authors: Sugahara Takaya , Sasabe Takashi , Naito Hiroshi , Kodama Manabu , Hirai Shuichiro
Published: September 2022

To clarify the behavior of liquid water in polymer electrolyte fuel cell (PEFC), X-ray computed tomography (XTM) is used. In the past, 3D visualization experiments of liquid water in substrate layer and microporous layer (MPL) were conducted. However, 3D visualization of liquid water in catalyst layer (CL) has not been conducted yet. It is important to clarify liquid water in CL because water is generated in CL. We improved two things. First, we used the CL with low platinum percentage because its X-ray absorption coefficient is low. Second, 20.5-hour CT scan was conducted to improve spatial resolution. Therefore, we succeeded the detection of liquid water in CL.
Hydrogen Crossover Flux through Two-Dimensional Nanomaterials
Authors: Gaffrey Karli Ann , Bukola Saheed , Blackburn Jeff , Pivovar Bryan S.
Published: September 2022

Energy storage and conversion devices require an ion-exchange membrane with high transmission of charge-balancing ions and separation of anode and cathode electrolytes/gases. This ensures optimum device performance. Most conventional membranes suffer huge cross-permeation resulting in low energy efficiency and material degradation. This work investigated hydrogen permeability and proton transmission through membrane electrode assemblies (MEAs) containing a monolayer of hexagonal boron nitride and single-layer and bi-layer graphene in a gas-phase small-scale cell and a liquid cell. We found that the hydrogen crossover flux through MEAs with 2D materials was inhibited by at least a factor of 5 compared to the one without. Single-layer graphene and boron nitride enabled high proton transmission, but bi-layer graphene inhibited proton conduction. Defect visualization of 2D materials revealed few atomic-scale defects in graphene. These findings suggest that a monolayer of 2D material may provide good selectivity for energy conversion and storage devices by blocking species crossover while allowing high proton transmission.
Attribution of H+ Transportation of Nafion-Film on Different Substrates Using Planar Inter-Digitated Electrodes
Authors: Bhardwaj Rahul , Karan Kunal , Nagao Yuki
Published: September 2022

In-plane proton transport property of Nafion thin-film on carbon and quartz was investigated in N2 environment by electrochemical impedance spectroscopy (EIS) using interdigitated electrodes (IDEs) of platinum on quartz substrate. The Pt IDEs with and without carbon pad were fabricated with precise geometry and excellent current-voltage (I-V) response in few hundreds femtoampere (fA). The morphology of spin-coated Nafion thin-film over IDEs was confirmed to adapt the geometry of IDE structure. The EIS impedance response of Nafion thin-film consists of single semi-circular component in either IDEs. Since Pt-C IDE has both ionomer/quartz and ionomer/carbon interface therefore H+ conductivity at quartz and carbon was estimated from the quantitative attribution of H+ transport resistance. The estimated H+ conductivity at quartz from Pt-C IDE and Pt-Q IDE shows comparable conductivity values except the high relative humidity (RH) and indicates that H+ transport resistance at carbon substrate in Pt-C IDE is absent in N2 environment.
Investigation of a Method of Evaluating Proton Transport Resistance in PEFC Catalyst Layers
Authors: Mizuta Yosuke , Nagayama Mayumi , Sasaki Kazunari , Hayashi Akari
Published: September 2022

Since there is no method to directly measure proton conductivity in the catalyst layer in PEFC even though proton conduction in the catalyst layer is one of the critical factors for high performance and durability. A method to directly measure proton transport resistance in the catalyst layers was investigated by sandwiching a sample layer by two Nafion® membranes to block electron transfer, and two gas diffusion electrodes to reduce gas diffusion resistance, in this study. Direct current was applied to the system in the hydrogen atmosphere, and measurements for proton transport resistance were performed in various sample layers. As a result, proton transport resistance in sample layers was successfully evaluated, and such measurements lead to improvement of current-voltage performance of PEFC.
Utilisation of Ammonium Carbonate in a Solid Oxide Cell
Authors: Ragu Marta , Laycock Christian James , Owen Gareth R , Lloyd Gareth , Guwy Alan J
Published: September 2022

Production of coke required for steel manufacturing generates coke oven gas (COG) as by-product. Cleaning of COG yields an aqueous waste stream containing ammonia, water, phenol, carbon dioxide and trace components. Currently, this waste stream is disposed of by incineration. Due to the presence of carbon dioxide, a significant fraction of the ammonia is present as ammonium carbonate, (NH4)2CO3. This work investigates the utilisation of aqueous (NH4)2CO3 in a commercially-available solid oxide cell at 750 °C. The cell performance was characterised by current-voltage (I-V) curves and was shown to have excellent electrical performance in electrolysis mode. Online quadrupole mass spectrometry (QMS) measurements show (NH4)2CO3 catalytically decomposed to form nitrogen, hydrogen and carbon dioxide, with electrolysis at 1.4 V increasing hydrogen production by 50 vol%. The cell had very good performance in fuel cell mode, although this was tempered due to OCV losses caused by the carbon dioxide present.
Electrochemical Formation of Dy-Ni Alloys in a Molten Cesium Chloride System
Authors: Konishi Hirokazu , Takao Tatsuya , Oishi Tetsuo , Nohira Toshiyuki , Koizumi Yuichiro
Published: September 2022

The electrochemical formation of Dy–Ni alloys was investigated in a molten CsCl-DyCl3 system at 973 K under a dry Ar atmosphere. Open-circuit potentiometry was performed with a Ni electrode after depositing Dy metal at 0.18 V (vs. Cs+/Cs) for 90 min. Five potential plateaus were observed at 0.29 V, 0.42 V, 0.52 V, 0.77 V and 0.90 V, which were considered to correspond to the potentials of two-phase coexisting states of different Dy–Ni alloys. Potentiostatic electrolysis was conducted at 0.28 V for 4 h and 0.38 V for 1 h using Ni plate electrodes, and XRD analysis indicated the formation of DyNi and DyNi2, respectively. After the formation of DyNi2 on the Ni plate electrodes, potentiostatic electrolysis were also conducted at 0.46 V, 0.66 V and 0.82 V for 1 h. The formed DyNi2 was transformed to DyNi3 at 0.46 V, Dy2Ni7 at 0.66 V, DyNi5 at 0.82 V.
Kinetic and Thermodynamic Properties of Ytterbium Chloride and Fluoride Complexes in Chloride Melts
Authors: Kuznetsov Sergey A , Stulov Yuriy V. , Gaune-Escard Marcelle
Published: September 2022

The electrochemical behavior of ytterbium in NaCl-KCl, KCl and CsCl melts was studied in the temperature range 973-1173 K by different electrochemical methods. The diffusion coefficients (D) of Yb(III) and Yb(II) were determined by linear sweep voltammetry, chronopotentiometry and chronoamperometry methods. The standard rate constants of charge transfer (k
s) for the Yb(III)/Yb(II) redox couple were calculated on the basis of cyclic voltammetry data using Nicholson’s equation. The formal redox potentials E*

Yb(III)/Yb(II) were obtained in alkali chlorides melts from the cyclic voltammetry data. The influence of fluoride ions on the standard rate constants in the NaCl-KCl melt was investigated.
Electrodeposition of Aluminium and Co-Deposition of Alloying Elements Titanium, Manganese and Silicon in Molten Fluoride Electrolyte
Authors: Haarberg Geir Martin , Awayssa Omar , Meirbekova Rauan , Xu Wenting , Saevarsdottir Gudrun
Published: September 2022

Primary aluminium is produced by the Hall-Heroult process which is based on electrolysis in molten fluoride electrolyte, Na3AlF6-AlF3, at ~960 oC in which the raw material alumina is dissolved and decomposed into pure aluminium and CO2 gas due to the use of carbon anodes. Alloys are made by adding pure metals prior to the casting process. An alternative approach to produce alloys by co-deposition of alloying elements during electrolysis, where metal oxides of alloying elements are added to the electrolyte, is under study. Laboratory experiments were carried out to quantify the impact of co-deposition of alloying elements of titanium, manganese and silicon. Current efficiencies above 90 % and acceptable conversion of metal oxide to metal were obtained for electrodeposition of aluminium alloys with titanium, manganese and silicon. The proposed method for producing aluminium based alloys directly in the Hall-Heroult process may give substantial benefits in terms of cost and efficiency.
Multiplexed Electrochemical Device for the Detection of Biomarkers of Parkinson’s Disease Using 3D Printing
Authors: Ho Nguyen H. B. , Glasco Dalton Lee , Sopp Rhys N. , Bell Jeffrey Gordon
Published: September 2022

Acetylcholine and dopamine are two important neurotransmitters when diagnosing Parkinson’s disease, as the imbalance in acetylcholine and dopamine levels can lead to progressive neurological disorders. Currently, there are many detection methods for the individual neurotransmitters with their own advantages and disadvantages. Previously, dopamine has been highlighted as the most relevant biomarker for diagnosis, but interest in combined detection of acetylcholine and dopamine has increased. Since it has been discovered that both motor function and learning difficulties in Parkinsonism is dependent on dopamine and acetylcholine levels, determination of both biomarkers simultaneously has increased therapeutic relevance. This work reports the detection of acetylcholine and dopamine using 3D printed potentiometric and 3D printed voltammetric sensors, respectively. Linear responses were obtained over broad concentration ranges for both biomarkers with a fully 3D printed ion-selective membrane (acetylcholine) and conductive carbon electrodes (dopamine). This work describes a novel fabrication protocol for sensors that have the capability to detect both biomarkers simultaneously when integrated into a low-cost, reliable, and user-friendly multiplexed device, also fabricated with 3D printing technologies.
Identification of CeRNA Regulatory Networks in Atrial Fibrillation Using Nanodelivery
Authors: Lin Ping , Meng Lingqiang , Lyu Lei
Published: September 2022

The initiation and maintenance of AF is a complex biological process that is the ultimate manifestation of many cardiovascular diseases. And the pathogenesis of atrial fibrillation (AF) is unclear. Therefore, this study aimed to find the potential competing endogenous RNAs (ceRNAs) network and molecular dysregulation mechanism associated with AF. GSE135445, GSE2240, and GSE68475 were obtained from the Gene Expression Omnibus (GEO). Differential analysis was utilized to identify the differentially expressed mRNAs, miRNAs, and lncRNAs between AF and sinus rhythms (SR). AF-associated mRNAs and nanomaterials were screened and their biological functions and KEGG signaling pathways were identified. Nanomaterials for targeted delivery are uniquely capable of localizing the delivery of therapeutics and diagnostics to diseased tissues. The target mRNAs and target lncRNAs of differentially expressed miRNAs were identified using TargetScan and LncBase databases. Finally, we constructed the ceRNAs network and its potential molecular regulatory mechanism. We obtained 643 AF-associated mRNAs. They were significantly involved in focal adhesion and the PI3K-Akt signaling pathway. Among the 16 differentially expressed miRNAs identified, 31 differentially expressed target mRNAs, as well as 5 differentially expressed target lncRNAs were identified. Among them, we obtained 2 ceRNAs networks (hsa-miR-125a-5p and hsa-let-7a-3p). The aberrant expression of network target genes in AF mainly activated the HIF-1 signaling pathway. We speculated that the interaction pairs of miR-125a-5p and let-7a-3p with target mRNAs and target lncRNAs may be involved in AF. Our findings have a positive influence on investigating the pathogenesis of AF and identifying potential therapeutic targets.
[Retracted] Analysis of the Influence of Library Information on the Utilization of Regional Environmental and Ecological Resources: From the Perspective of Intelligent Adaptive Learning
Authors: Jiang Shujie , Yang Xuemei
Published: September 2022

In order to further develop and improve the management theory of public libraries, this paper studies the impact of library information on the utilization of regional environmental resources from the perspective of intelligent adaptive learning. Firstly, based on the data envelopment analysis method, this paper measures the efficiency of Public Libraries in various regions of China. Then, using Tobit model, this paper analyzes the environmental factors affecting the efficiency of public libraries from three aspects: financial allocation, per capita GDP, and per capita years of education. The results show that there is a significant correlation between per capita GDP, per capita years of education, and the efficiency of public libraries. There is a significant negative correlation between per capita GDP and public library efficiency (the coefficient is −5.73x10−6, and the probability of two‐sided t‐test is 0.0229); There is a significant positive correlation between the number of years of education per capita and the efficiency of Public Libraries (the coefficient is 0.0684, and the probability of two‐sided t‐test is 0.0169). Conclusion: This study provides a reference for the performance evaluation of provincial public libraries.
Gender Discrimination of Flower Buds of Mature Populus tomentosa by HPLC Fingerprint Combined with Chemometrics
Authors: Li Zhuojun , Wu Cui , Xu Bo , Wang Huijun , Song Pingping , Liu Zhenying , Chao Zhimao
Published: September 2022

A high performance liquid chromatography-diode array detector (HPLC-DAD) was used to establish the HPLC fingerprint. Chemometrics methods were used to discriminate against the gender of flower buds of Populus tomentosa based on areas of common peaks calibrated with the HPLC fingerprint. The score plot of principal component analysis (PCA) showed a clear grouping trend (R2X, 0.753; Q2, 0.564) between female and male samples. Two groups were also well discriminated with orthogonal partial least squares-discriminant analysis (OPLS-DA) (R2X, 0.741; R2Y, 0.980; Q2, 0.970). As the hierarchical clustering analysis (HCA) heatmap showed, all samples were separated into two groups. Four compounds were screened out by S-plot and variable importance in projection (VIP > 1.0). Two of them were identified as siebolside B and tremulacin. This study demonstrated that HPLC fingerprints combined with chemometrics can be applied to discriminate against dioecious plants and screen differences, providing a reference for identifying the gender of dioecious plants.
[Retracted] A Deep Learning‐Based TE Method for MSs’ Mental Health Analysis
Authors: Tao Ranxin
Published: September 2022

Teaching evaluation (TE) is of great significance in education and can judge the value and appropriateness of the curriculum, which is a distinguished part of the educational work. Compared with other courses focusing on imparting knowledge, mental health not only imparts psychological knowledge but also cultivates Marxism students’ (MSs) ability to adjust psychology and maintain mental health. Therefore, the evaluation of this course has a special character. As the unity of scientific world outlook and values, Marxism can promote students’ mental health. When assessing students’ ability to maintain mental health, the influence of Marxism should be taken into account. In this study, we first established an evaluation index system in line with the actual mental health considering the influence of Marxism and put forward a deep memory network with prior information (PI‐DMN) to realize the aspect‐based sentiment analysis (ABSA) of the student evaluation text. Combined with students’ scoring of the course, the sentiment analysis results are used as the input dataset of LSTM model to realize the TE of mental health course. The data analysis exposes that Marxism can promote mental health, and the empirical analysis reveals that the accuracy of TE can be improved by considering the sentiment analysis of comment texts and can also be improved to a certain extent after aspect labeling of the dataset.
lncRNA MSC-AS1/miRNA-429 Axis Mediates Growth and Metastasis of Nasopharyngeal Carcinoma via JAK1/STAT3 Signaling Pathway
Authors: Luo Ni
Published: September 2022

Objective. We attempted to clarify the effect of lncRNA MSC-AS1 on carcinogenic and development of nasopharyngeal carcinoma (NPC) and the related mechanisms. Methods. The levels of MSC-AS1 and miR-429 were estimated in NPC tissues and cells using qRT-PCR. Correlation analysis, dual-luciferase report, and RNA pull down assay assessed the action association of MSC-AS1 and miR-429. MTT, colony formation, cell wound scratch, and transwell assays were used to assess the proliferation, invasion, and migration of C666-1 cells. Metastasis-related protein expressions and activation of the JAK1/STAT3 pathway were confirmed by western blot and immunohistochemistry. Results. The expression of MSC-AS1 presented significant upregulation, and miR-429 expression was markedly downregulated in NPC tissues and cells. The level of MSC-AS1 had negative relation to the miR-429 level. Knockdown of MSC-AS1 suppressed the proliferation, invasion, and migration of C666-1 cells. On the contrary, overexpressing of MSC-AS1 exerts the opposite effects on C666-1 cell growth and migration. miR-429 was determined as functional downstream of MSC-AS1. The suppressive function of MSC-AS1 knockdown was predominately abolished by the miR-429 inhibitor. miR-429 was an antitumor gene inhibiting NPC growth and metastasis through JAK1/STAT3 pathway. In C666-1 cells, the elevated cell growth and migration induced by the miR-429 inhibitor were significantly reversed by si-JAK1 transfection. Conclusions. High expression of MSC-AS1 exerted a carcinogenic effect on NPC cell growth and metastasis by inhibiting miR-429 and activating the JAK1/STAT3 pathway.
Investigation of Mechanical and Tribological Properties of AA6061/MWCNT/B4C Hybrid Metal Matrix Composite
Authors: Satishkumar P. , Natarajan N. , Saminathan Rajasekaran , Hillary J. Justin Maria , Birhanu Biru , Alguno Arnold C. , Capangpangan Rey Y. , Raj Vishnu , Livingston Stephen
Published: September 2022

Carbon nanotubes (CNTs) and graphene, in particular, have been the subject of many recent studies since their discovery in the early 2000s. Because of their unusual properties, carbon nanotubes (CNTs) have piqued the interest of scientists across a wide range of disciplines. An Al matrix was reinforced with powder metallurgy-fabricated B4C and CNT composites. The nanocomposite aluminium matrix was examined for tribological behaviour, density, stiffness, and compressive strength before and after hot isostatic pressing (HIP). Scanning electron microscopy and TEM were used to analyze the carbon nanotubes and their hybrid counterparts (SEM). The density of nanocomposites was reduced by 38% without HIP but by 45% after it was added to the mixture. Hardness was also increased by 40%, but following HIP, the hardness rose to 67%. Before and after HIP, the compression strength increased by 39% and 60%, respectively. HIP improves the wear rate by 45%, and B4C and CNTs improve the coefficient of friction by 20% in all volume fractions but only by 48% in the case of nanocomposites.
The Analysis of Environmental Cost Control of Manufacturing Enterprises Using Deep Learning Optimization Algorithm and Internet of Things
Authors: Qiu Jin , Chen Wenzhuo
Published: September 2022

Under the background of the Internet of things (IoT), the problems between the actual production and the environment are also prominent. The environmental cost control in the production process of manufacturing enterprises are discussed to reduce the environmental cost and promote the improvement of production efficiency. First, the environmental cost under the background of IoT is analyzed. Also, the environmental cost control methods in the production process of traditional manufacturing enterprises are investigated. Second, based on the principle of traditional genetic algorithm, the fast-nondominated sorting genetic algorithm (NSGA-II) of multiobjective genetic algorithm is introduced to complete the optimization of BP neural network (BPNN) algorithm in deep learning (DL), and the multiobjective GA optimization BPNN model is established. Finally, the multiobjective GA algorithm is used to empirically analyze the environmental cost control capability of a paper-making enterprise. It is compared with enterprises with excellent and poor environmental cost control capabilities in the same industry to find out secondary indexes. The results show that environmental costs have long-term and economic characteristics. The global search ability of BPNN optimized by multiobjective GA is improved, and the local optimal dilemma is avoided. Through empirical analysis, it is found that the comprehensive capability of the environmental cost control of the enterprise is better, scored 79 or more, and the indexes of insufficient development and advantages are obtained. As IoT rapidly develops, it is necessary to further improve the ability of enterprises in environmental cost management, which is very important to promote the development of enterprises and enhance their core competitiveness. It is hoped that this investigation can provide certain reference significance for improving the environmental cost management capability of enterprises, increasing production efficiency, and reducing environmental costs.
A Novel Approach for Estimating Performance of IIoT-Based Virtual Control Train Sets under DoS Attacks
Authors: Ma Shuomei , Wang Hongwei , Li Zhu , Zhang Qihe
Published: September 2022

The virtually coupled train sets (VCTS) have been proposed to improve operational capability and passenger satisfaction and ensure punctuality, thus alleviating the rapidly worsening traffic pressure. Recently, due to the lack of reliable wireless communications and accurate perceptual information, VCTS based on industrial internet of things (IIoT) are receiving growing concerns by integrating into the IIoT, AI, and edge computing. However, denial of service (DoS) attacks are feasible for IIoT-based VCTS due to the physically exposed open electromagnetic environment. They would cause severe safety and punctuality problems, such as poor real-time capability, enormous packet dropout rates, extensive train operational delays, and disturbance in the train convoy’s dynamic schedule. This paper deeply discusses the effects of DoS attacks on the performances of the IIoT-based VCTS by combing the physical layer with the cyber layer and explores the requirement of an attacker. We consider that the system is under the attack of a rational DoS attacker with limited jamming attacks, which will cause the most system state offset. In the paper, we propose a novel train status estimation approach to compensate for the losing information of the front train by the trade-off between the best gain of the DoS attacker and the punctuality of the IIoT-based VCTS. System performance includes physical dynamic indicators, train operational delay variance, and average waiting time of passengers. Taken together, these findings indicate that the established status estimation approach can effectively mitigate safety concerns and reduce train operational delays.
A Review on Vertical Take-Off and Landing (VTOL) Tilt-Rotor and Tilt Wing Unmanned Aerial Vehicles (UAVs)
Authors: Misra Akshat , Jayachandran Sudhakaran , Kenche Shivam , Katoch Anirudh , Suresh Arjun , Gundabattini Edison , Selvaraj Senthil Kumaran , Legesse Addisalem Adefris
Published: September 2022

The Vertical Take-off and Landing (VTOL) unmanned aerial vehicles (UAVs) with the tilt-rotor mechanism also known as hybrid UAVs have a lot of challenges in designing and controlling concerning their use in harsh weather for surveillance and access to remote areas. This review paper presents a review of the preliminary design of hybrid aircraft and control systems. The tilt-rotor mechanism and tilt wings of a hybrid UAV are analyzed. The paper provides an outline of technical advances in UAVs in hybrid configuration concerning their constraint analysis, propulsion sizing, and design evaluation. Furthermore, the flight dynamics modeling is described with the control system and dynamics of the hybrid UAV. This paper lists various software for simulations and analysis such as SOLIDWORKS and CATIA for CAD modeling, MATLAB and SIMULINK for mathematical modeling and flight control, and XFLR5 for stability analysis of aerofoils, wings, and planes. In addition, certain control strategies are executed and scrutinized in terms of the theory, the linearity, and the implementation of the model.
Research on University Network Public Opinion Monitoring and Early Warning System Based on Big Data
Authors: Yang Ruoqi
Published: September 2022

Undergraduate self-consciousness is still in the formative stage and is highly susceptible to external environment. Schools must adapt to the new forms and requirements, improve their ability to search, analyze, and prevent online public opinion through big data technologies; we should make early discovery, early action, and early resolution, so as not to give time and space for public opinion crisis fermentation and consolidate the dominant position of the mainstream ideology. This paper focuses on the university network public opinion monitoring and early warning system based on big data and analyzes the university public opinion from the perspective of the specificity, sensitivity, identification, early warning and prevention ability of the system to deal with public opinion, and effectively solves the network public opinion crisis. Combined with the current actual situation and specific needs, this paper explores the intervention measures and guidance strategies for the network public opinion of college emergencies, so as to lay a solid foundation for the healthy, stable, and sustainable development of colleges and universities.
A Model Predictive Control for Lot Sizing and Scheduling Optimization in the Process Industry under Bidirectional Uncertainty of Production Ability and Market Demand
Authors: Tang Qi , Wang Yiran
Published: September 2022

In the face of bidirectional uncertainty of market demand and production ability, this paper establishes a multiobjective mathematical model for lot sizing and scheduling integrated optimization of the process industry considering both material network and production manufacturing and finds the optimal decision of the model through model predictive control to minimize total completion time and total production cost. While realizing the model predictive control proposed in this paper, the Elman neural network predicts the relevant parameters required by learning historical orders for the uncertain market demand and equipment production ability. Then, the calculation formulas of product supply and demand matching and equipment production ability are formed and introduced into the next stage of the model as a constraint condition. In addition to the above constraints for constructing lot sizing and scheduling integrated models in the process industry, this paper also considers both the material network and production manufacturing and uses the IMOPSO algorithm to solve the problem iteratively. So far, a complete model predictive control can be generated. Through the model predictive control, the production system can respond in advance, make appropriate changes to offset the foreseeable interference, and obtain the lot sizing and scheduling scheme considering bidirectional uncertainty, thereby improving the system’s overall robustness. Finally, this paper realizes the model's predictive control process through example simulation and analyzes the operation results combined with the scheduling Gantt chart to verify the applicability and effectiveness of the model.