bluuebunny/crossref_metadata_2025 huggingface dataset:
Rate Control Technology for Next Generation Video Coding Overview and Future Perspective
Authors: Zeng Hao , Xu Jun , He Shuqian , Deng Zhengjie , Shi Chun
Published: December 2022

Video data have become the main data traffic on the Internet, and their traffic is increasing explosively every year, thus increasing the pressure of video transmission. Video coding technology has become the key to compressing original videos. As an indispensable technology, rate control plays an important role in stabilizing video stream transmission. Rate control (RC) is part of rate distortion optimization (RDO) whose job is to find the optimal solution based on balancing rate and distortion. It not only needs to consider the buffer and network status but also adjust the corresponding bit rate according to the video content. This paper reviews the related technologies of rate control under high efficiency video coding (HEVC) and versatile video coding (VVC) standards so that subsequent researchers can quickly understand the field and promote the development of rate control algorithms. Firstly, the paper summarizes the various aspects of RC, including basic principles, rate-distortion models, major processes, and performance criteria. Secondly, the paper surveys, in detail, the research progress in the field of rate control and analyzes several mainstream research directions. Thirdly, we carry out relevant experiments on the standard reference software and analyze and discuss the experimental results of the existing studies. Finally, we look ahead to the future trends of rate control and provide feasible improvement suggestions.
Deep Learning Architecture for Flight Flow Spatiotemporal Prediction in Airport Network
Authors: Zang Haipei , Zhu Jinfu , Gao Qiang
Published: December 2022

Traffic flow prediction is a significant component for the new generation intelligent transportation. In the field of air transportation, accurate prediction of airport flight flow can help airlines schedule flights and provide a decision-making basis for airport resource allocation. With the help of Deep Learning technology, this paper focuses on the characteristics of flight flow easily disturbed by environmental factors, studies the spatiotemporal dependence between flight flows, and predicts the spatiotemporal distribution of flight flows from the airport network level. We proposed a deep learning architecture named ATFSTNP, which combining the residual neural network (ResNet), graph convolutional network (GCN), and long short-term memory (LSTM). Based big data analytics of air traffic management, this method takes the spatiotemporal causal relationship between weather impact and flight flow as the core, and deeply mines the complex spatiotemporal relationship of flight flow. The model’s methodologies are improved from the practical application level, and extensive experiments conducted on the China’s flight operation dataset. The results illustrate that the improved model has significant advantages in predicting the flight flow under weather affect. Even in the complex and variable external environment, the model can still accurately predict the spatiotemporal distribution of the airport network flight flow, with strong robustness.
X-Band Active Phased Array Antenna Using Dual-Port Waveguide for High-Power Microwave Applications
Authors: Liu Rong , Wang Naizhi , Li Tong , Zhang Ruoqiao , Wu Hongchao
Published: December 2022

An X-band active phased array horn antenna with high power capacity and high peak power is proposed in this paper. At the horn aperture, the baffles are loaded to suppress higher-order modes and eliminate blind spots during beam scanning. Straight walls are added to improve impedance matching. Considering that the peak power that T/R modules can provide is very limited, the proposal of a dual-port waveguide breaks through the bottleneck of the power capacity of a single-port input for the first time. The proposed curved dual-port waveguide is used to connect the horn antenna and the T/R module, which is verified to improve the power capacity of the overall internal structure. Simulated and measured results show that VSWR ≤ 2 in the frequency range of 7.5–8.5 GHz. There is no grating lobe in the ±10° scanning range and the maximum gain drop does not exceed 0.4 dB. The power capacity of the proposed HPM array is 56.34 MW. The phased array antenna has the characteristics of flexible scanning, small size, and high gain, and can be applied in high-power microwave systems.
On CFD-Assisted Research and Design in Engineering
Authors: Eskin Dmitry
Published: December 2022

At present, computational fluid dynamics (CFD) is an inherent component of the development procedure of a majority of technological processes involving fluid flows and/or heat and mass transfers. Practicing engineers and investigators employ different commercial CFD software, open-source codes and even develop their own computational codes (in house) for solving tasks, requiring accounting for nonstandard effects.
Looking at Diabetes-Related Distress through a New Lens: The Socio-Ecological Health Model
Authors: Farnoudi Neeka , Lyang Mimi , Vanderwyk Kees , Vreeburg Sarah , Young Clipper
Published: December 2022

Diabetes-related distress (DRD) is defined as an emotional state experienced by people with diabetes (PWD) who are worried about their disease management, the emotional burden from the condition, and/or potential difficulties accessing care or support. The psychosocial aspect of diabetes management is a factor that directly influences patients’ well-being as well as the chronic management of the condition yet is not a primary clinical problem being addressed within the healthcare setting. This review advocates for a re-evaluation and subsequent adjustment of the current DRD screening methodology by implementing the five primary components (Intrapersonal, Interpersonal, Organizational, Community, and Public Policy) of the Socio-Ecological Model of Health (SEMH), bridging the gaps from a public-health perspective. We searched two electronic databases for studies published in the United States from 1995 to 2020 reporting the effects of social determinants of health (SDOH) on DRD. Articles that contained at least one of the five elements of the SEMH and focused on adults aged 18 years or older were included. SDOH, which include circumstances where individuals grow, work, and age, are highly influenced by external factors, such as the distribution of wealth, power, and resources. Current DRD screening tools lack the capacity to account for all major components of SDOH in a comprehensive manner. By applying the SEMH as a theory-based framework, a novel DRD screening tool addressing sex, ethnicity, and socioeconomic background should be implemented to better improve diabetes management outcomes. By exploring the relationships between each level of the SEMH and DRD, healthcare professionals will be better equipped to recognize potential stress-inducing factors for individuals managing diabetes. Further efforts should be invested with the goal of developing a novel screening tool founded on the all-encompassing SEMH in order to perpetuate a more comprehensive diabetes treatment plan to address barriers within the SDOH framework.
An Investigation of Instability on Constant Shear Drained (CSD) Path under the CSSM Framework: A DEM Study
Authors: Nguyen Hoang Bao Khoi , Rahman Md Mizanur , Karim Md Rajibul
Published: December 2022

Soil liquefaction or instability, one of the most catastrophic phenomena, has attracted significant research attention in recent years. The main cause of soil liquefaction or instability is the reduction in the effective stress in the soil due to the build-up of pore water pressure. Such a phenomenon has often been thought to be related to the undrained shearing of saturated or nearly saturated sandy soils. Notwithstanding, many researchers also reported soil instability under a drained condition due to the reduction in lateral stress. This condition is often referred to as the constant shear drained (CSD) condition, and it is not uncommon in nature, especially in a soil slope. Even though several catastrophic dam failures have been attributed to CSD failure, the failure mechanisms in CSD conditions are not well understood, e.g., how the volumetric strain or effective stress changes at the triggering of flow deformation. Researchers often consider the soil fabric to be one of the contributors to soil behaviour and use this parameter to explain the failure mechanism of soil. However, the soil fabric is difficult to measure in conventional laboratory tests. Due to that reason, a numerical approach capable of capturing the soil fabric, the discrete element method (DEM), is used to investigate the CSD shearing mechanism. A series of simulations on 3D assemblies of ellipsoid particles was conducted. The DEM specimens exhibited instability behaviour when the effective stress paths nearly reached the critical state line. It can be clearly observed that the axial and volumetric strains changed suddenly when the stress states were close to the critical state line. Alongside these micromechanical observations, the study also presents deeper insights into soil behaviour by relating the macro-observations to the micromechanical aspect of the soil.
A Map Tile Data Access Model Based on the Jump Consistent Hash Algorithm
Authors: Wang Wei , Yao Xiaojing , Chen Jing
Published: December 2022

Tiled maps are one of the key GIS technologies used in the development and construction of WebGIS in the era of big data; there is an urgent need for high-performance tile map services hosted on big data GIS platforms. To address the current inefficiency of massive tile map data management and access, this paper proposes a massive tile map data access model that utilizes the jump consistent hash algorithm. Via the uniformity and consistency of a certain seed of a pseudo-random function, the algorithm can generate a storage slot for each tile data efficiently. By recording the slot information in the head of a row key, a uniform distribution of the tiles on the physical cluster nodes is achieved. This effectively solves the problem of hotspotting caused by the monotonicity of tile row keys in the data access process, thereby maximizing the random-access performance of a big data platform and greatly improving concurrent database access. Experiments show that this model can significantly improve the efficiency of tile map data access by more than 39% compared to a direct storage method, thereby confirming the model’s advantages in accessing massive tile map data on a big data GIS platform.
Progressive Collapse of Dual-Line Rivers Based on River Segmentation Considering Cartographic Generalization Rules
Authors: Zhang Fubing , Sun Qun , Ma Jingzhen , Lyu Zheng , Wen Bowei
Published: December 2022

Collapse is a common cartographic generalization operation in multi-scale representation and cascade updating of vector spatial data. During transformation from large- to small-scale, the dual-line river shows progressive collapse from narrow river segment to line. The demand for vector spatial data with various scales is increasing; however, research on the progressive collapse of dual-line rivers is lacking. Therefore, we proposed a progressive collapse method based on vector spatial data. First, based on the skeleton graph of the dual-line river, the narrow and normal river segments are preliminarily segmented by calculating the width of the river. Second, combined with the rules of cartographic generalization, the collapse and exaggeration priority strategies are formulated to determine the handling mode of the river segment. Finally, based on the two strategies, progressive collapse of dual-line rivers is realized by collapse and exaggeration of the river segment. Experimental results demonstrated that the progressive collapse results of the proposed method were scale-driven, and the collapse part had no burr and topology problems, whereas the remaining part was clearly visible. The proposed method can be better applied to progressive collapse of the dual-line river through qualitative and quantitative evaluation with another progressive collapse method.
Interpretation of Spatial-Temporal Patterns of Community Green Spaces Based on Service Efficiency and Distribution Characteristics: A Case Study of the Main Urban Area of Beijing, China
Authors: Zu Xiaoyi , Li Zhixian , Gao Chen , Wang Yi
Published: December 2022

Urban-scale green spaces have been a central topic as of late, but community-scale green spaces are overlooked in urban studies. This paper takes community green spaces in the main urban area of Beijing as the case to quantitatively interpret the spatial-temporal patterns of their service efficiency and distribution characteristics. The measurement section of the paper includes two parts: the first part compares the applicability of two major green space service efficiency measurement methods on the community scale and determines that the Shortest Time Distance method performs better in describing the spatial-temporal patterns of service efficiency. The second part applies the Time Distance Entropy method to initially identify the locational relationship between community green spaces and neighboring residential buildings, then proposes the Green Space Distribution Coefficient method based on this relationship to analyze the ‘courtyard’, ‘mixed’, and ‘centralized’ distribution types alongside the transition relationships between them, and the spatial-temporal patterns of distribution characteristics are measured. The results of service efficiency reveal that the community paradigms transform from ‘humanistic-oriented’ to ‘benefit-oriented’ as the Shortest Time Distance measurement values show an ascending trend with the passage of years and the outward expansion of the ring roads. The results of distribution characteristics reveal that the community residential culture transforms from ‘closeness’ to ‘detachment’ as Green Space Distribution Coefficient measurement values show a descending trend under the same conditions. Based on the measurements, this paper further provides several optimizing strategies for community green spaces in the central urban area of Beijing.
VGI and Satellite Imagery Integration for Crisis Mapping of Flood Events
Authors: Vavassori Alberto , Carrion Daniela , Zaragozi Benito , Migliaccio Federica
Published: December 2022

Timely mapping of flooded areas is critical to several emergency management tasks including response and recovery activities. In fact, flood crisis maps embed key information for an effective response to the natural disaster by delineating its spatial extent and impact. Crisis mapping is usually carried out by leveraging data provided by satellite or airborne optical and radar sensors. However, the processing of these kinds of data demands experienced visual interpretation in order to achieve reliable results. Furthermore, the availability of in situ observations is crucial for the production and validation of crisis maps. In this context, a frontier challenge consists in the use of Volunteered Geographic Information (VGI) as a complementary in situ data source. This paper proposes a procedure for flood mapping that integrates VGI and optical satellite imagery while requiring limited user intervention. The procedure relies on the classification of multispectral images by exploiting VGI for the semi-automatic selection of training samples. The workflow has been tested with photographs and videos shared on social media (Twitter, Flickr, and YouTube) during two flood events and classification consistency with reference products shows promising results (with Overall Accuracy ranging from 87% to 93%). Considering the limitations of social media-sourced photos, the use of QField is proposed as a dedicated application to collect metadata needed for the image classification. The research results show that the integration of high-quality VGI data and semi-automatic data processing can be beneficial for crisis map production and validation, supporting crisis management with up-to-date maps.
Insecticidal Activity of a Component, (-)-4-Terpineol, Isolated from the Essential Oil of Artemisia lavandulaefolia DC. against Plutella xylostella (L.)
Authors: Huang Xing , Du Linjie , Liu Tiantian , Ma Rui , Liu Xing , Yuan Haibin , Liu Shuai
Published: December 2022

Plutella xylostella (L.) is one of the most serious pests of cruciferous vegetables. Our previous work demonstrated that the essential oil of Artemisia lavandulaefolia DC. exhibits promising insecticidal activities against P. xylostella. This study further characterizes the key components that are responsible for the insecticidal effect. In total, 47 compounds (96.52% of the total compounds) were identified from the total oil using GC-MS, and the major compounds were eucalyptol (21.57%), D(+)-camphor (17.33%), (-)-4-terpineol (9.96%) and caryophyllene oxide (10.96%). Among them, (-)-4-terpineol showed significantly larvicidal and fumigant activities against P. xylostella. The LD50 of (-)-4-terpineol was 43.15 mg/mL at 12 h and 31.22 mg/mL at 24 h for 3rd instar larvae, and the LC50 for adults was 8.34 mg/mL at 12 h and 7.35 mg/mL at 24 h. In addition, the adults treated with (-)-4-terpineol showed varying degrees of inhibitory activity toward glutathione S-transferase, catalase, acetylcholinesterase and Na+/K+-ATPase at different post-treatment intervals and concentrations. The results indicate that (-)-4-terpineol has promising insecticidal activities against P. xylostella, and it has good inhibitory effects on the four enzymes of P. xylostella adults.
Severity of Post-Operative Pain after Instrumentation of Root Canals by XP-Endo and SAF Full Sequences Compared to Manual Instrumentation: A Randomized Clinical Trial
Authors: Pawar Ajinkya M. , Bhardwaj Anuj , Zanza Alessio , Wahjuningrum Dian Agustin , Arora Suraj , Luke Alexander Maniangat , Karobari Mohmed Isaqali , Reda Rodolfo , Testarelli Luca
Published: December 2022

This investigation aimed to examine the post-operative pain experienced following single-visit root canal treatment using the XP-endo shaper sequence (XPS), full-sequence self-adjusting file (SAF), and manual K-files (HKF). A randomized equivalence parallel design, double-blinded clinical study was conducted on 120 patients with symptomatic irreversible pulpitis, with or without clinical signs of apical periodontitis. Only teeth with fully formed roots and no periapical lesions were incorporated in the study. Patients were apportioned to one of three groups (n = 40) randomly: Group 1—XPS, Group 2—SAF, and Group 3—HKF. Pre- and post-instrumentation pain was rated utilizing Visual Analog Scale (VAS) with a spectrum of 0–100 mm. The descriptive statistics and one-way ANOVA with 95% confidence intervals were used for statistical analysis. The mean VAS scores before instrumentation were consistent in all three groups. At 6, 24, 48, and 72 h, patients with root canals instrumented by SAF had the lowest post-instrumentation mean VAS score, followed by XPS. For all time intervals, the patients in the HKF group had the highest VAS score. The full-sequence SAF instrumentation resulted in less post-operative pain than the XP-endo plus protocol, while manual instrumentation with K-files resulted in the highest post-operative pain.
Cutting-Edge Green Polymer/Nanocarbon Nanocomposite for Supercapacitor—State-of-the-Art
Authors: Kausar Ayesha , Ahmad Ishaq , Maaza Malik , Eisa M. , Bocchetta Patrizia
Published: December 2022

Supercapacitors have attained a special stance among energy storage devices such as capacitors, batteries, fuel cell, and so forth. In this state-of-the-art overview on green synthesis approaches and green materials for supercapacitors, the cutting-edge green polymer/nanocarbon nanocomposite systems were explored by focusing on the design and related essential features. In this regard, various polymers were reconnoitered including conjugated polymers, thermosetting matrices, and green-cellulose-based matrices. Nanocarbon nanomaterials have also expanded research thoughtfulness for green-technology-based energy storage devices. Consequently, green polymer/nanocarbon nanocomposites have publicized fine electron conduction pathways to promote the charge storage, specific capacitance, energy density, and other essential features of supercapacitors. Future research directions must focus on the design of novel high performance green nanocomposites for energy storage applications.
Cell–Matrix Interactions in Renal Fibrosis
Authors: Kim Kristin P. , Williams Caitlin E. , Lemmon Christopher A.
Published: December 2022

Renal fibrosis is a hallmark of end-stage chronic kidney disease. It is characterized by increased accumulation of extracellular matrix (ECM), which disrupts cellular organization and function within the kidney. Here, we review the bi-directional interactions between cells and the ECM that drive renal fibrosis. We will discuss the cells involved in renal fibrosis, changes that occur in the ECM, the interactions between renal cells and the surrounding fibrotic microenvironment, and signal transduction pathways that are misregulated as fibrosis proceeds. Understanding the underlying mechanisms of cell–ECM crosstalk will identify novel targets to better identify and treat renal fibrosis and associated renal disease.
Evolution of Land Use Landscape Patterns in Karst Watersheds of Guizhou Plateau and Its Ecological Security Evaluation
Authors: Li Yue , Geng Huacai
Published: December 2022

Landscape ecological safety is of great significance in maintaining ecological balance, ecological protection, economic development, and promoting the sustainable use of regional land resources. This study collects three-phase remote sensing (RS) image data of 2000, 2010, and 2020 to elucidate the spatial and temporal changes in land use of the Guizhou Plateau Karst Watershed. We construct a landscape ecological security index using the ArcGIS and landscape pattern index method. With the spatial autocorrelation theory, we analyze the evolution of watershed landscape patterns and changes in characteristics of ecological security. The results show that the cultivated land is being converted to construction land in the watershed from 2000 to 2020. The percentage of the patch area of the constructed land is increasing. However, the patch cohesion of the cultivated land, grassland, and watershed is decreasing. The ecological safety of the Nanming River Basin landscape is in a positive trend, clustering in the central urban areas. The growth rate of the landscape ecological safety index increased by 5.80% from 2000 to 2020, and the aggregation of the ecological safety index was dominated by high–high aggregation and low–low aggregation, which was spatially positively correlated with the spatial aggregation effect. The findings provide a scientific reference for managing ecological balance and optimizing the land resource allocation in karst watersheds.
Refugees as Migrant Workers after the Global Compacts? Can Labour Migration Serve as a Complementary Pathway for People in Need of Protection into Sweden and Germany?
Authors: Vankova Zvezda
Published: December 2022

Both the Global Compact for Safe, Orderly and Regular Migration and the Global Compact on Refugees commit states to diversify and expand on labour migration opportunities, in particular by facilitating work-based ‘complementary pathways’ for the admission of refugees. Yet, almost four years after their adoption, such pathways remain limited in many cases. It is the aim of this article to examine the constraints posed by existing immigration laws to serve as an admission ground for people in need of protection and the key legal, policy and political issues that need to be addressed to allow the commitments related to labour migration pathways contained in the Compacts to be implemented in national legal systems. In so doing, this article applies a legal and political feasibility lens to evaluate why these pathways for persons in need of protection are often small-scale, underutilized by employers and unwelcoming to potential refugees. It employs a comparative case study methodology drawing on more than 30 semi-structured interviews with stakeholders at the international and national levels in Germany and Sweden. The article concludes that the main challenge to the political feasibility of opening work-based complementary pathways for refugees is politicians’ and policy makers’ traditional thinking of migration and asylum as separate domains. When it comes to challenges to legal feasibility, these stem from entry requirements, lack of sufficient interest among employers who are a key stakeholder in the facilitation of such pathways, as well as issues related to the security of status of potential beneficiaries of such measures.
Biodigestion System Made of Polyethylene and Polystyrene Insulator for Dog Farm (on the Example of the Republic of Chile)
Authors: Vivallos Soto Cristian , Ruiz Bertín Francisco , Robles Calderón Carolina , Larionov Maxim Viktorovich , Arias Ordóñez Priscila Jackeline , Cevallos Baque Ivette
Published: December 2022

Anaerobic digestion is a system that can have a high environmental impact through the use of different wastes to obtain biogas and its consequent use for the generation of renewable energy. The objective of this study was to implement a polyethylene biodigester, using polystyrene for thermal insulation in a dog kennel, using canine feces collected in the same place during a period of 5 months to obtain biogas and energy. The results indicated that biogas production started on day 30 and stopped during the winter period with low temperatures; therefore, from day 54 onwards, equine manure was added to continue producing biogas. Although biogas was obtained, the biodigester did not function optimally, due to the fact that the materials used in its construction did not provide efficient insulation from the low external temperatures; the low C/N ratio of the canine feces, which led to a reduction in the processing of the methanogenic bacteria; and the low amount of feces collected for use. In general, the use of a biodigester can provide a tool for the biological processing and management of organic waste, yielding a cumulative source of renewable energy and ensuring environmental safety.
Quality of Life and Persistence of Symptoms in Outpatients after Recovery from COVID-19
Authors: Gutiérrez-Canales Lizeth Guadalupe , Muñoz-Corona Carolina , Barrera-Chávez Isaac , Viloria-Álvarez Carlos , Macías Alejandro E. , Guaní-Guerra Eduardo
Published: December 2022

Background and Objectives: Patients infected with SARS-CoV-2 can have persistent symptoms after acute illness, which affects their quality of life (QoL). Research and data about this topic in Latin American ambulatory patients are scarce. Materials and Methods: We conducted an observational, prospective, transversal, and analytical study. To measure QoL, we used a validated Spanish version of the MOS/RAND 36-Item Short Form Health Survey (SF-36). Results: We included 206 outpatients in the study. A total of 73.3% patients had persistence of one or more symptoms. The most frequent persistent symptoms were fatigue (36.9%), anxiety (26.2%), and headache (24.8%). No statistically significant difference in the SF-36 QoL scores and the frequency of persistent COVID-19 symptoms was found when comparing the ≤5 and >5 months groups, except for myalgia, which was less frequently observed in the >5 months group after COVID-19 (26.2% vs. 14.1%, p < 0.038). Female gender was associated with an increased risk of persistence of symptoms (OR = 2.95, 95% CI 1.56–5.57). Having comorbidities/sequelae attributed to COVID-19 and persistence of COVID-19 symptoms were associated risk factors for poor physical component summary (PCS); on the other hand, female gender, anxiety, and depression were associated with poor mental component summary (MCS). Conclusion: Most outpatients had persistent COVID-19 symptoms after infection. Persistence of symptoms was associated with poor MCS and PCS. It is important to follow-up not only patients discharged from the hospital after SARS-CoV-2 infection, but also those under ambulatory management to provide them with rehabilitation and psychological therapy to improve their QoL.
Efficiency Analysis of Fuel Cell Components with Ionic Poly-Arylether Composite Membrane
Authors: Wen Hsin-Yi , Wang Guang-Hsiang , Chang Mei-Ying , Huang Wen-Yao , Hsieh Tung-Li
Published: December 2022

We use polyethylene glycol as an additive to explore how the hydrogen bonding of this additive changes the properties of SA8 blended sulfonated polyetheretherketone (SPEEK) composite films. We mixed a 5%wt polyethylene glycol solution into a 12.5%wt SA8 solution, and then prepared a film with a total weight of 40 g at a ratio of 1:99. The SA8 (PEG) solution was prepared and then mixed with 5%wt SPEEK solution, and a film-forming solution with a total weight of 8g in different mixing ratios was created. Polyethylene glycol (PEG) was mixed into the sulfonated polyarylether polymer SA8 to form physical cross-linking. Therefore, the sulfonated polyether ether ketone SPEEK was mixed in, and it exhibited good thermal stability and dimensional stability. However, there was some decrease in proton conductivity as the proportion of SPEEK increased. Although SPEEK mixed with sulfonated polymer reduces the proton conductivity, the physical cross-linking of PEG can improve the proton conductivity of the composite membrane, and adding SPEEK can not only solve the problem of the high sulfonation film swelling phenomenon, it can also improve the dimensional stability of the film through the hydrogen bonding force of PEG and obtain a composite film with excellent properties.
Bio-Assisted Leaching of Non-Ferrous Metals from Waste Printed Circuit Boards—Importance of Process Parameters
Authors: Vardanyan Arevik , Vardanyan Narine , Aâtach Mohamed , Malavasi Pierre , Gaydardzhiev Stoyan
Published: December 2022

The effect of varying process parameters during bio-catalyzed leaching of metals from end-of-life printed circuit boards (PCBs) was investigated. Fragmented PCBs (under 2 mm) were subjected to an indirect bioleaching in a stirred tank reactor while pulp density, pH and initial ferric iron content were varied. An iron oxidizing Acidithiobacillus ferrooxidans 61 microbial strain was used to generate the lixiviant through oxidizing Fe(II) to Fe(III). Chemically generated Fe(III) was tested as lixiviant under the same conditions as the biological one for comparative purposes. Cell enumeration during leaching and microscopic observations of the input and leached PCBs were conducted in parallel to shed light on the observed phenomena. The degree of bringing metals in solution was found to depend mainly on ferric iron concentration and pH. For the entire duration being always kept as 24 h, substantial portion of Cu (~87%) was extracted respectively at 1% pulp density (PD), 15.5 g/L Fe3+ and pH 1. For Zn and Ni, nearly 100% recovery was observed at 5% PD, 18 g/L Fe3+ and pH 1.1. The achieved results offer possibilities for further studies at higher pulp density, to ultimately render the bioleaching approach as enabling economical and environmentally friendly technology for urban mining of non-ferrous metals.
The Role of the Graphene Oxide (GO) and PEO Treated-Zinc Oxide (ZnO/PEO) Intermediate Electrode Buffer Layer in Vacuum-Free Quantum Dots Solar Cell
Authors: Kang Seung Beom , Jo Younjung , Lam Nguyen Hoang , Jung Jae Hak , Kim Chang-Duk , Truong Nguyen Tam Nguyen
Published: December 2022

The vacuum-free quantum dots solar cell (VFQDSC) was fabricated without using any vacuum process. The spherical iron pyrite (FeS2) nanoparticles (SNPs) and ZnO nanoparticles (NPs) were synthesized and characterized. In the device structure, FeS2 SNPs were used as an acceptor material (n-type), and the low band gap polymer of poly[4,8-bis(2-ethylhexyloxyl)benzo[1,2-b:4,5-b′]-dithiophene-2,6-diyl-alt-ethylhexyl-3-fluorothieno[3,4-b]thiophene-2-carboxylate-4,6-diyl] (PBT7) was used as a donor material (p-type). In this study, we first applied the graphene oxide (GO) as the hole transport buffer layer (HTBL) and zinc oxide (ZnO) as an electron transport buffer layer (ETBL), which were considered to improve the charge transportation efficiency of the device’s system. The device with the structure of the Glass/ITO/HTBL/FeS2 SNPs, PBT7/ ETBL/E-GaIn were fabricated with a maximum power conversion efficiency (PCE) of 3.6%.
Effect of CMT Welding Heat Input on Microstructure and Properties of 2A14 Aluminum Alloy Joint
Authors: Zhao Yili , Chen Furong , Cao Silong , Chen Chao , Xie Ruijun
Published: December 2022

Cold metal transfer (CMT) welding is an attractive welding technology for thin sheet aluminum alloys because of its low heat input, arc stability and spatter-free behavior during the welding process. The present research is mainly concerned with the effect of different heat input on microstructure and mechanical properties of CMT welding 2A14 aluminum alloy in 3 mm thickness. The results indicate that a welded joint with good quality can be achieved when the welding current is 105 A and welding speed is 8 mm/s. The weld width and porosity gradually increase along with the constantly increasing welding heat input. The center of the welded joint consists of a large number of fine equiaxed dendrites, and the gray matrix is uniformly distributed accompanied by a large number of dots and blocks as a white second phase, corresponding to the composition of the Al2Cu phase. The microhardness of welded joints under different welding heat input maintains relative stability and presents a certain softening degree; the base material is the highest, followed by the heat-affected zone.
Innovative Variation in the Morphological Characteristics of Carbon Nanowalls Grown on a Molybdenum Disulfide Interlayer
Authors: Kim Chulsoo , Kim Kangmin , Kwon Seokhun , Kang Hyunil , Hong Byungyou , Choi Wonseok
Published: December 2022

Carbon is a material with interesting properties which exists in large quantities on Earth, so many studies involving carbon have been conducted. In particular, nano-sized carbon allotropes, referred to as carbon nanomaterials, comprise the subject of various studies currently underway. The electrical, chemical, physical properties of carbon nanowalls (CNWs) are modified by parameters such as surface density, height and thickness. These characteristics have significant effects on CNWs and can be adjusted as a growth interlayer. It was confirmed that the molybdenum disulfide (MoS2) interlayer synthesized in this paper by radio frequency (RF) magnetron sputtering altered the morphological characteristics of the CNWs, including its shaped edge, pores diameter and density. We provide interesting results through FE-SEM, EDS and Raman analysis in this paper. Based on the Raman analysis, both the D-peak of carbon and the ID/IG ratio decreased. Through this study, the effect of MoS2 on the morphological characteristics of CNWs was confirmed.
Antimicrobial Nano Coatings
Authors: Ivask Angela , Ahonen Merja , Kogermann Karin
Published: December 2022

History has demonstrated that the uncontrolled fast thriving of potentially pathogenic microorganisms may lead to serious consequences and, thus, the approaches helping to control the microbial numbers in infectional hot-spots are necessary [...]
Advanced Nanostructured Materials for Electrocatalysis in Lithium–Sulfur Batteries
Authors: Song Zihui , Jiang Wanyuan , Jian Xigao , Hu Fangyuan
Published: December 2022

Lithium–sulfur (Li-S) batteries are considered as among the most promising electrochemical energy storage devices due to their high theoretical energy density and low cost. However, the inherently complex electrochemical mechanism in Li-S batteries leads to problems such as slow internal reaction kinetics and a severe shuttle effect, which seriously affect the practical application of batteries. Therefore, accelerating the internal electrochemical reactions of Li-S batteries is the key to realize their large-scale applications. This article reviews significant efforts to address the above problems, mainly the catalysis of electrochemical reactions by specific nanostructured materials. Through the rational design of homogeneous and heterogeneous catalysts (including but not limited to strategies such as single atoms, heterostructures, metal compounds, and small-molecule solvents), the chemical reactivity of Li-S batteries has been effectively improved. Here, the application of nanomaterials in the field of electrocatalysis for Li-S batteries is introduced in detail, and the advancement of nanostructures in Li-S batteries is emphasized.
Studies on Oxygen Permeation Resistance of SiCN Thin Film and RRAM Applications
Authors: Song Myeong-Ho , Ko Woon-San , Kim Geun-Ho , Choi Dong-Hyeuk , Lee Ga-Won
Published: December 2022

In this study, a silicon carbon nitride (SiCN) thin film was grown with a thickness of 5~70 nm by the plasma-enhanced chemical vapor deposition (PECVD) method, and the oxygen permeation characteristics were analyzed according to the partial pressure ratio (PPR) of tetramethylsilane (4MS) to the total gas amount during the film deposition. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), and X-ray reflectivity (XRR) were used to investigate the composition and bonding structures of the SiCN film. An atomic force microscope (AFM) was used to examine the surface morphology of the SiCN films to see the porosity. The analysis indicated that Si–N bonds were dominant in the SiCN films, and a higher carbon concentration made the film more porous. To evaluate the oxygen permeation, a highly accelerated temperature and humidity stress test (HAST) evaluation was performed. The films grown at a high 4MS PPR were more susceptible to oxygen penetration, which changed Si–N bonds to Si–N–O bonds during the HAST. These results indicate that increasing the 4MS PPR made the SiCN film more porous and containable for oxygen. As an application, for the first time, SiCN dielectric film is suggested to be applied to resistive random access memory (RRAM) as an oxygen reservoir to store oxygen and prevent a reaction between metal electrodes and oxygen. The endurance characteristics of RRAM are found to be enhanced by applying the SiCN.
Theoretical and Computational Analysis of a Wurtzite-AlGaN DUV-LED to Mitigate Quantum-Confined Stark Effect with a Zincblende Comparison Considering Mg- and Be-Doping
Authors: Solís-Cisneros Horacio I. , Hu Yaoqiao , Camas-Anzueto Jorge L. , Grajales-Coutiño Rubén , Anwar Abdur-Rehman , Martínez-Revuelta Rubén , Hernández-de-León Héctor R. , Hernández-Gutiérrez Carlos A.
Published: December 2022

In this work, an AlGaN-based Deep-Ultraviolet Light-Emitting Diode structure has been designed and simulated for the zincblende and wurtzite approaches, where the polarization effect is included. DFT analysis was performed to determine the band gap direct-to-indirect cross-point limit, AlN carrier mobility, and activation energies for p-type dopants. The multiple quantum wells analysis describes the emission in the deep-ultraviolet range without exceeding the direct-to-indirect bandgap cross-point limit of around 77% of Al content. Moreover, the quantum-confined Stark effect on wavefunctions overlapping has been studied, where Al-graded quantum wells reduce it. Both zincblende and wurtzite have improved electrical and optical characteristics by including a thin AlGaN with low Al content. Mg and Be acceptor activation energies have been calculated at 260 meV and 380 meV for Be and Mg acceptor energy, respectively. The device series resistance has been decreased by using Be instead of Mg as the p-type dopant from 3 kΩ to 0.7 kΩ.
The Stability of Hybrid Perovskites with UiO-66 Metal–Organic Framework Additives with Heat, Light, and Humidity
Authors: Zhidkov Ivan S. , Yu Ming-Hsuan , Kukharenko Andrey I. , Han Po-Chun , Cholakh Seif O. , Yu Wen-Yueh , Wu Kevin C.-W. , Chueh Chu-Chen , Kurmaev Ernst Z.
Published: December 2022

This study is devoted to investigating the stability of metal–organic framework (MOF)-hybrid perovskites consisting of CH3NH3PbI3 (MAPbI3) and UiO-66 without a functional group and UiO-66 with different COOH, NH2,and F functional groups under external influences including heat, light, and humidity. By conducting crystallinity, optical, and X-ray photoelectron spectra (XPS) measurements after long-term aging, all of the prepared MAPbI3@UiO-66 nanocomposites (with pristine UiO-66 or UiO-66 with additional functional groups) were stable to light soaking and a relative humidity (RH) of 50%. Moreover, the UiO-66 and UiO-66-(F)4 hybrid perovskite films possessed a higher heat tolerance than the other two UiO-66 with the additional functional groups of NH2 and COOH. Tthe MAPbI3@UiO-66-(F)4 delivered the highest stability and improved optical properties after aging. This study provides a deeper understanding of the impact of the structure of hybrid MOFs on the stability of the composite films.
Steep-Slope and Hysteresis-Free MoS2 Negative-Capacitance Transistors Using Single HfZrAlO Layer as Gate Dielectric
Authors: Tao Xinge , Liu Lu , Xu Jingping
Published: December 2022

An effective way to reduce the power consumption of an integrated circuit is to introduce negative capacitance (NC) into the gate stack. Usually, negative-capacitance field-effect transistors (NCFETs) use both a negative-capacitance layer and a positive-capacitance layer as the stack gate, which is not conductive to the scaling down of devices. In this study, a steep-slope and hysteresis-free MoS2 NCFET is fabricated using a single Hf0.5−xZr0.5−xAl2xOy (HZAO) layer as the gate dielectric. By incorporating several Al atoms into the Hf0.5Zr0.5O2 (HZO) thin film, negative capacitance and positive capacitance can be achieved simultaneously in the HZAO thin film and good capacitance matching can be achieved. This results in excellent electrical performance of the relevant NCFETs, including a low sub-threshold swing of 22.3 mV/dec over almost four orders of drain-current magnitude, almost hysteresis-free, and a high on/off current ratio of 9.4 × 106. Therefore, using a single HZAO layer as the gate dielectric has significant potential in the fabrication of high-performance and low-power dissipation NCFETs compared to conventional HZO/Al2O3 stack gates.
Applications of Nanomaterials and Nanotechnology in Energy Storage Device
Authors: Bae Joonho
Published: December 2022

Nanomaterials and nanotechnology have played central roles in the realization of high-efficiency and next-generation energy storage devices [...]
Green Extraction of Graphene from Natural Mineral Shungite
Authors: Novikova Anastasia , Karabchevsky Alina
Published: December 2022

Conventional fabrication methods to produce graphene are cumbersome, expensive, and not ecologically friendly. This is due to the fact that the processing of a large volume of raw materials requires large amounts of acids and alkalis which, in turn, require special disposal. Therefore, it is necessary to develop new technologies or to refine existing ones for the production of graphene—and to create new, ecologically-safe and effective methods. Here, we utilized physical sonication to extract graphene films from natural mineral shungite rock. From our study of the structure of shungite by Raman spectrometry and X-ray phase analysis, we found that shungite is characterized by graphite-like mineral structures. Transmission electron microscopy images obtained from the processed material revealed graphene films—with surfaces as small as 200 nanometers long and several layers wide. Our green method of fabicating graphene can be widely used in a variety of fields, from electro-optics to ecology, to list a few.
Critical Effect of Oxygen Pressure in Pulsed Laser Deposition for Room Temperature and High Performance Amorphous In-Ga-Zn-O Thin Film Transistors
Authors: Zhou Yue , Wang Dao , Li Yushan , Jing Lixin , Li Shuangjie , Chen Xiaodan , Zhang Beijing , Shuai Wentao , Tao Ruiqiang , Lu Xubing , Liu Junming
Published: December 2022

The aspects of low processing temperature and easy running in oxygen atmosphere contribute to the potential of pulsed laser deposition (PLD) in developing a-IGZO TFTs for flexible applications. However, the realization of low-temperature and high-performance devices with determined strategies requires further exploration. In this work, the effect of oxygen pressure and post-annealing processes and their mechanisms on the performance evolution of a-IGZO TFTs by PLD were systematically studied. A room-temperature a-IGZO TFT with no hysteresis and excellent performances, including a μ of 17.19 cm2/V·s, an Ion/Ioff of 1.7 × 106, and a SS of 403.23 mV/decade, was prepared at the oxygen pressure of 0.5 Pa. Moreover, an O2 annealing atmosphere was confirmed effective for high-quality a-IGZO films deposited at high oxygen pressure (10 Pa), which demonstrates the critical effect of oxygen vacancies, rather than weak bonds, on the device’s performance.
Engineering the Exchange Spin Waves in Graded Thin Ferromagnetic Films
Authors: Yanilkin Igor , Gumarov Amir , Golovchanskiy Igor , Gabbasov Bulat , Yusupov Roman , Tagirov Lenar
Published: December 2022

The results of experimental and theoretical studies of standing spin waves in a series of epitaxial films of the ferromagnetic Pd1−xFex alloy (0.02 < x < 0.11) with different distributions of the magnetic properties across the thickness are presented. Films with linear and stepwise, as well as more complex Lorentzian, sine and cosine profiles of iron concentration in the alloy, and thicknesses from 20 to 400 nm are considered. A crucial influence of the magnetic properties profile on the spectrum of spin wave resonances is demonstrated. A capability of engineering the standing spin waves in graded ferromagnetic films for applications in magnonics is discussed.
Ranpirnase (OKG-0301), a Novel Ribonuclease, Demonstrates Antiviral Activity against Adenovirus in the Ad5/NZW Rabbit Ocular Replication Model
Authors: Romanowski Eric G. , Yates Kathleen A. , Daniels Eric J. , Strem Brian M. , Romanowski John E. , Kowalski Regis P.
Published: December 2022

Adenovirus ocular infections are common ocular viral infections seen worldwide, for which there is no approved antiviral therapy available. Ranpirnase is a novel ribonuclease which preferentially degrades tRNA resulting in an inhibition of protein synthesis. The study goal was to determine the anti-adenoviral activity of topical formulations of ranpirnase (OKG-0301) on adenoviral replication in the Ad5/NZW rabbit ocular replication model. NZW rabbits were inoculated in both eyes with human adenovirus type 5 (HAdV5) after corneal scarification. A day later, topical therapy was initiated in both eyes with 0.03% OKG-0301, 0.003% OKG-0301, saline or 0.5% cidofovir. Eyes were cultured to determine HAdV5 eye titers over 2 weeks. OKG-0301 (0.03% and 0.003%) and 0.5% cidofovir decreased viral titers compared to saline. Furthermore, both OKG-0301 formulations and 0.5% cidofovir shortened the duration of the HAdV5 infection compared to saline. Both 0.03% OKG-0301 and 0.003% OKG-0301 demonstrated increased antiviral activity compared to saline in the Ad5/NZW rabbit ocular replication model. The antiviral activity of the OKG-0301 groups was similar to that of the positive antiviral control, 0.5% cidofovir. Ranpirnase (OKG-0301) may be a potential candidate for a topical antiviral for adenoviral eye infections. Further clinical development is warranted.