bluuebunny/crossref_metadata_2025 huggingface dataset:
On Physical Urban Boundaries, Urban Sprawl, and Compactness Measurement: A Case Study of the Wen-Tai Region, China
Authors: Dai Xiaoling , Jin Jiafeng , Chen Qianhu , Fang Xin
Published: September 2022

China’s rapid urbanization has been accompanied by serious urban sprawl. Instead of measuring the physical urban boundaries (PUBs), most of existing studies in China rely on yearbook statistics to describe the growth of urbanized area; therefore, the understanding of the actual form and quantity of urban sprawl are restrained. As the statistical unit is generally at or above the county level, these studies tend to omit the lower-level “larger towns”. This paper discusses the measurement of urban sprawl and compactness using multi-source data on the GIS platform through the case study of the Wen-Tai region in China. GlobeLand30 remote sensing image data, vector road network data, NPP/VIIRS nighttime light data, and points of interest (POIs) data are adopted. The new method enhances the identification of built-up areas in larger towns. Besides, the 2020s’ PUBs of this region, data for 2010 and 2000 are retraced to assess the urban expansion rate, and two approaches are used to discuss the urban growth pattern. Additionally, a compactness model is constructed from four dimensions, i.e., the compactness of external contour, accessibility of road network, land-use intensity, and functional diversity, by which a high-resolution visual analysis tool is created for the provincial government to monitor urban sprawl.
Innovative Fusion-Based Strategy for Crop Residue Modeling
Authors: Fathololoumi Solmaz , Karimi Firozjaei Mohammad , Biswas Asim
Published: September 2022

The purpose of this study was to present a new strategy based on fusion at the decision level for modeling the crop residue. To this end, a set of satellite imagery and field data, including the Residue Cover Fraction (RCF) of corn, wheat and soybean was used. Firstly, the efficiency of Random Forest Regression (RFR), Support Vector Regression (SVR), Artificial Neural Networks (ANN) and Partial-Least-Squares Regression (PLSR) in RCF modeling was evaluated. Furthermore, to increase the accuracy of RCF modeling, different algorithms results were combined based on their modeling error, which is called the decision-based fusion strategy. The R2 (RMSE) between the actual and modeled RCF based on ANN, RFR, SVR and PLSR algorithms for corn were 0.83 (3.89), 0.86 (3.25), 0.76 (4.56) and 0.75 (4.81%), respectively. These values were 0.81 (4.86), 0.85 (4.22), 0.78 (5.45) and 0.74 (6.20%) for wheat and 0.81 (3.96), 0.83 (3.38), 0.76 (5.01) and 0.72 (5.65%) for soybean, respectively. The error of corn, wheat and soybean RCF estimating decision-based fusion strategy was reduced by 0.90, 0.96 and 0.99%, respectively. The results showed that by implementing the decision-based fusion strategy, the accuracy of the RCF modeling was significantly improved.
Crowding Perception at the Archaeological Site of Tulum, Mexico: A Key Indicator for Sustainable Cultural Tourism
Authors: Enseñat-Soberanis Fernando , Blanco-Gregory Rocío
Published: September 2022

Just before the lockdown caused by the SARS-CoV-2/COVID-19, the archeological sites close to the Mexican Caribbean were having an exponential number of visitors. The restrictions on traveling due to the pandemic resulted in a decrease in the number of visitors; however, the visitor flow is rising again. This scenario provides a historical opportunity to carry out strategies towards the visitor’s management as well as to awake consciousness of the damage caused by the excess of visitors in cultural heritage sites. Establishing limits on the number of visitors is a well-recognized strategy to achieve sustainability in a cultural heritage site. An excess of visitors has an impact on two elements: the cultural resource and the quality of the visitor experience. Crowding perception has been demonstrated to be an effective indicator to evaluate the visitor experience and to determine standards of quality in cultural and natural sites. The place of origin of visitors is among the sociodemographic factors that can affect crowding standards. This study used a quantitative questionnaire based on normative theory and a visual method to identify the crowding standards of national and international visitors at the Mayan archaeological site of Tulum located in the vicinity of the Mexican Caribbean resort of Cancun. The results show that general visitor acceptability decreases as the number of people increase. International visitors are less tolerant to crowding than national visitors as they show the most restrictive acceptable level of people at the same time at the archaeological site. Findings are discussed in terms of their management implications for the development of a tourism-carrying capacity framework for cultural sites, thereby contributing to the achievement of more sustainable cultural tourism.
Tackling Comprehensive Evaluation of Tourism Community Resilience: A Probabilistic Hesitant Linguistic Group Decision Making Approach
Authors: Zhang Junling , Shen Linying , Liu Lijun , Qi Xiaowen , Liang Changyong
Published: September 2022

Community-based tourism (CBT) has been adopted as an effective and practical solution to land use policies by governments that simultaneously pursue upgrading of local economy, conservation of local ecosystem and development of local communities. Confronting with new normality of detrimental eventualities in situated environments, destination management organizations (DMOs) or local governments have to employ effective governance strategies for fostering tourism community resilience in order to sustain development of CBT destinations. In viewing of that facilitating development through evaluation usually manifests as an efficient strategy in governance practices, this paper contributes to fill two main gaps in tackling comprehensive evaluation of tourism community resilience. Firstly, by noticing the fact that current literature overlooks processual characteristics of tourism community resilience, which originate from integration of disaster management and destination management (DM2), we have developed an analytical framework comprised of six attributes for comprehensively evaluating tourism community resilience. Secondly, aiming at the phenomena that cognitive assessments on attributes of tourism community resilience often exhibit complicate uncertainties caused by low-structured or ill-structured problem nature, we have put forward a powerful expression tool of probabilistic dual hesitant fuzzy uncertain unbalanced linguistic set (PDHF_UUBLS) to simultaneously capture evaluators’ cognitive characteristics of decision hesitancy, bipolar epistemic notions and relative importance among assessments. Then by formalizing comprehensive evaluation of tourism community resilience as a multiple attributes decision making process, we construct an effective multiple attributes group decision making (MAGDM) approach with assessments in the form of PDHF_UUBLS. Theoretical analyses verify the effectiveness of our constructed MAGDM approach and also show the approach avoids potential information distortion in comparison with other approaches. Overall, this paper provides effective and pertinent solutions, with both analytical framework and methodology, to the urgent task of comprehensive evaluation of tourism community resilience in DM2 agenda, thereby is of apparent significance in governance practice of CBT.
A Study on the Cognition of Urban Spatial Image at Community Scale: A Case Study of Jinghu Community in Zhengzhou City
Authors: Zhou Xiaowen , Li Hongwei , Zhang Huili , Zhang Rongrong , Li Huan
Published: September 2022

The community is the basic spatial unit for urban residents to live and rest. It is a crucial direction of city image research to explore people’s cognitive characteristics of community space image. Aiming at the lack of cognitive quantification of community spatial images, a new method that can quantify community spatial data into cognitive results is proposed. By employing spatial analysis tools, eleven spatial indicators from the perspective of community spatial form and spatial services are selected, and an image structure is constructed based on the characteristics of the indicator results. The results of multiple indicators are organized through the improved technique for order preference by similarity to ideal solution (TOPSIS) and overlay analysis method to produce a spatial image map of the community. The study displays that the spatial image characteristics of the community scale can be comprehensively expressed through three types of elements: district, path (edge), and node (landmark). These three types of elements constitute the image structure at the community scale and present apparent elements’ characteristics. This scrutiny is also aimed to demonstrate the construction and use process of the methodology and to provide new ideas for the cognitive research of urban spatial image at the community scale.
Tempo-Spatial Variations in Soil Hydraulic Properties under Long-Term Organic Farming
Authors: Abu-hashim M. , Lilienthal H. , Schnug E. , Kucher Dmitry E. , Mohamed Elsayed Said
Published: September 2022

Adequate knowledge of tempo-spatial variability on soil hydraulic properties plays an important role in irrigation scheduling and precision farming. This study was conducted to compare the impact of tempo-spatial variations in long-term conservation tillage applications in organic farming (superficial tillage using a chisel at 10 cm depth) on soil properties. Soil measurements, including infiltration capacity, saturated hydraulic conductivity (Ks), effective bulk density, and penetration resistance, were investigated in 2012 and compared to data from 2008 at the same fields in Baden-Württemberg, Germany. Long-term organic farming reflected a relative increase in Ks values with temporal variability 33% more in 2012 than in 2008, while soil texture was virtually time-invariant. The Ks increased from 27.06, 24.42, 40.46, 17.49, and 22.59 cm d−1 in 2008 to 33.17, 28.79, 47.75, 38.99, and 40.82 cm d−1 in 2012 for sample locations I, II, III, IV, and V, respectively. The effective bulk density values decreased from 1.72, 1.72, 1.68, 1.64, and 1.81 Mg m−3 in 2008 to 1.63, 1.56, 1.67, 1.32, and 1.48 Mg m−3 in 2012 for sample locations I, II, III, IV, and V, respectively. For spatial variations within the same season, variances in computed Ks values were attributed to differences in the soil textures and effective bulk density between different parcels. As the soil was managed by organic farming for a long time, the soil depth compactness was more pronounced in 2012 than in 2008. Nevertheless, the Ks values showed a temporal increase from 2008 to 2012 due to the preferential water flow pathways approach used in organic farming. Estimated Ks values by the Hydrus-1D model in 2012 were five times higher than in 2008. With soil depth, Ks values revealed a decreasing trend over time. Using the numerical model, Hydrus-1D was representative for comparing hydraulic parameters and simulating water transfer in the soil matrix.
Alleviation of Cadmium Stress by Silicon Supplementation in Peas by the Modulation of Morpho-Physio-Biochemical Variables and Health Risk Assessment
Authors: Batool Tahira , Javied Sabiha , Ashraf Kamran , Sultan Khawar , Zaman Qamar uz , Haider Fasih Ullah
Published: September 2022

Agricultural soil quality degradation by potentially toxic elements, specifically cadmium (Cd), poses a significant threat to plant growth and the health of humans. However, the supplementation of various salts of silicon (Si) to mitigate the adverse effect of Cd on the productivity of peas (Pisum sativum L.) is less known. Therefore, the present investigation was designed to evaluate the exogenous application at various levels (0, 0.50, 1.00 and 1.50 mM) of silicate compounds (sodium and potassium silicates) on pea growth, gaseous exchange, antioxidant enzyme activities and the potential health risk of Cd stress (20 mg kg−1 of soil) using CdCl2. The findings of the study showed that Cd stress significantly reduced growth, the fresh and dry biomass of roots and shoots and chlorophyll content. In addition, electrolyte leakage, antioxidant enzymes and the content of Cd in plant tissues were enhanced in Cd-induced stressed plants. An application of Si enhanced the development of stressed plants by modulating the growth of fresh and dry biomass, improving the chlorophyll contents and decreasing leakage from the plasma membrane. Furthermore, Si addition performed a vital function in relieving the effects of Cd stress by stimulating antioxidant potential. Hence, a significant level of metal protection was achieved by 1.00 mM of potassium silicate application under the Cd levels related to stress conditions, pointing to the fact that the Si concentration required for plant growth under Cd stress surpassed that which was required for general growth, enzymatic antioxidants regulation and limiting toxic metal uptake in plant tissues under normal conditions. The findings of this research work provide a feasible approach to reduce Cd toxicity in peas and to manage the entry and accumulation of Cd in food crops.
Algal Biomass Utilization toward Circular Economy
Authors: Zabochnicka Magdalena , Krzywonos Małgorzata , Romanowska-Duda Zdzisława , Szufa Szymon , Darkalt Ahmad , Mubashar Muhammad
Published: September 2022

A review of the potential areas of algal biomass utilization has already been conducted. In addition to lowering the greenhouse effect and contributing to the decrease in the amounts of harmful substances in the air and water, attention has been paid to the possibility of utilizing algal biomass as a feedstock for the production of environmentally friendly products. The circular economy addresses the benefits to the environment, economy and society. The utilization of algal biomass benefits the environment by reducing greenhouse gases emissions as well as water and wastewater treatment, benefits the economy by producing biofuels, and benefits society by producing food, cosmetics, pharmaceuticals, fertilizers and feed for animals.
The Effect of Oral Citicoline and Docosahexaenoic Acid on the Visual Field of Patients with Glaucoma: A Randomized Trial
Authors: Anton Alfonso , Garcia Virginia , Muñoz Marcos , Gonzales Karla , Ayala Eleonora , del Mar Sanchez Estela , Morilla-Grasa Antonio
Published: September 2022

The role of nutraceuticals in the treatment of glaucoma remains controversial. The aim of this study was to evaluate the effect of citicoline, vitamin C, and docosahexaenoic acid (DHA) in patients with glaucoma. Methods: This was a prospective, randomized study. Patients with glaucoma were randomized to one of four groups and treated for 3 months with vitamin C, DHA, citicoline, or a combination of DHA and citicoline. We conducted a complete ophthalmic examination and visual fields each month and calculated the slopes of field indices. Changes in visual field indices (VFIs) and their slopes were assessed in each group and compared. Results: Seventy-three persons were included in the study. Mean defect (MD) significantly improved (p = 0.001) from −9.52 ± 4.36 to −7.85 ± 4.36 dB during the study period in persons taking DHA + citicoline. Similarly, the mean VFI significantly improved (p = 0.001) in this group. The only treatment group showing a statistically significant improvement (p = 0.006) in the MD (from −0.1041 ± 0.2471 to 0.1383 ± 0.2544 dB/month) and VFI slope was the group treated with DHA+citicoline. Conclusions: The combination of oral treatment with DHA + citicoline significantly improved VF indices and their slopes in patients with glaucoma after 3 months of treatment.
The Cumulative Detrimental Effect of COVID-19 Pneumonia in a Patient with Myasthenic Crisis: A Case Report and Overview of the Literature
Authors: Buzatu Georgiana-Cristina , Bobirca Florin-Teodor , Isac Sebastian , Mihalache Oana Antonia , Cotorogea-Simion Mihail , Tita Alina , Cobilinschi Cristian , Tanasescu Maria Daniela , Bobirca Anca , Droc Gabriela
Published: September 2022

Background: As the COVID-19 pandemic reached its peak, it became unavoidable that patients with other risk factors for severe pulmonary impairment (such as neuromuscular illnesses) would become afflicted. While the subject of myasthenic crisis secondary to COVID-19 pneumonia represents an interesting topic in the literature, we could not find consistent data that include, as a novel therapeutic approach, both intravenous immunoglobulin and plasma exchange therapy for the treatment of these two concurrent diseases. Case summary: A 69-year-old man with known seropositive generalized myasthenia gravis, hypertension, ischaemic heart disease, NYHA class II-III heart failure, cerebrovascular disease, and recurrent urinary tract infections, was admitted to the ICU for mixed acute respiratory failure, elevated serum lactate and liver function enzymes, and severe thrombocytopenia. A SARS-CoV-2 PCR test was positive, despite a previous COVID-19 pneumonia episode, 10 months prior to the current one. The patient had a recent ICU admission for a myasthenic crisis, which required non-invasive mechanical ventilation and intravenous immunoglobulin therapy. He received supportive therapy, as well as etiological (intravenous remdesivir, plasmapheresis and intravenous dexamethasone). Fifteen days after admission, the patient was transferred to the neurological ward, whence he left 20 days later, with no apparent sequelae. Conclusions: Subsequent intravenous immunoglobulins and plasma exchange therapy appear to be effective and safe in patients with simultaneous acute myasthenic episode and COVID-19 pneumonia.
Red Light Enhances Plant Adaptation to Spaceflight and Mars g-Levels
Authors: Medina Francisco-Javier , Manzano Aránzazu , Herranz Raúl , Kiss John Z.
Published: September 2022

Understanding how plants respond and adapt to extraterrestrial conditions is essential for space exploration initiatives. Deleterious effects of the space environment on plant development have been reported, such as the unbalance of cell growth and proliferation in the root meristem, or gene expression reprogramming. However, plants are capable of surviving and completing the seed-to-seed life cycle under microgravity. A key research challenge is to identify environmental cues, such as light, which could compensate the negative effects of microgravity. Understanding the crosstalk between light and gravity sensing in space was the major objective of the NASA-ESA Seedling Growth series of spaceflight experiments (2013–2018). Different g-levels were used, with special attention to micro-g, Mars-g, and Earth-g. In spaceflight seedlings illuminated for 4 days with a white light photoperiod and then photostimulated with red light for 2 days, transcriptomic studies showed, first, that red light partially reverted the gene reprogramming induced by microgravity, and that the combination of microgravity and photoactivation was not recognized by seedlings as stressful. Two mutant lines of the nucleolar protein nucleolin exhibited differential requirements in response to red light photoactivation. This observation opens the way to directed-mutagenesis strategies in crop design to be used in space colonization. Further transcriptomic studies at different g-levels showed elevated plastid and mitochondrial genome expression in microgravity, associated with disturbed nucleus–organelle communication, and the upregulation of genes encoding auxin and cytokinin hormonal pathways. At the Mars g-level, genes of hormone pathways related to stress response were activated, together with some transcription factors specifically related to acclimation, suggesting that seedlings grown in partial-g are able to acclimate by modulating genome expression in routes related to space-environment-associated stress.
Altered Expression of EMT-Related Factors Snail, Wnt4, and Notch2 in the Short-Term Streptozotocin-Induced Diabetic Rat Kidneys
Authors: Jurić Matea Dragun , Racetin Anita , Filipović Natalija , Kelam Nela , Kostić Sandra , Ljutić Dragan , Vukojević Katarina
Published: September 2022

Background: The aim of this study was to determine the expression of epithelial to mesenchymal transition (EMT)-related transcription factors Snail, Wnt4, and Notch2 with key roles in renal fibrosis, in different renal areas of diabetic rats: glomeruli (G), proximal and distal convoluted tubules (PCT; DCT). Methods: Male Sprague Dawley rats were instilled with 55 mg/kg streptozotocin (diabetes mellitus type I model, DM group) or citrate buffer (control group). Kidney samples were collected 2 weeks and 2 months after DM induction and processed for immunohistochemistry. Results: Diabetic animals showed higher Wnt4 kidney expression both 2 weeks and 2 months post-DM induction, while Snail expression significantly increased only 2 weeks after DM initiation (p < 0.0001). We determined significantly higher expression of examined EMT-related genes in different kidney regions in diabetic animals compared with controls. The most substantial differences were observed in tubular epithelial cells in the period of 2 weeks after induction, with higher Snail and Wnt4 expression in PCT and increased Snail and Notch2 expression in DCT of diabetic animals (p < 0.0001; p < 0.001). Conclusion: The obtained results point to the EMT-related factors Snail, Wnt4, and Notch2 as a potential contributor to diabetic nephropathy development and progression. Changes in their expression, especially in PCT and DCT, could serve as diagnostic biomarkers for the early stages of DM and might be a promising novel therapeutic target in this condition.
Heat Shock Protein 70 and 90 Family in Prostate Cancer
Authors: Fu Xun , Liu Jiang , Yan Xin , DiSanto Michael E. , Zhang Xinhua
Published: September 2022

Prostate cancer (PCa) is the second most frequent cancer that affects aging men worldwide. However, its exact pathogenesis has not been fully elucidated. The heat shock protein (HSP) family has cell-protective properties that may promote tumor growth and protect cancer cells from death. On a cellular level, HSP molecules have a strong relationship with multiple important biological processes, such as cell differentiation, epithelial–mesenchymal transition (EMT), and fibrosis. Because of the facilitation of HSP family molecules on tumorigenesis, a number of agents and inhibitors are being developed with potent antitumor effects whose target site is the critical structure of HSP molecules. Among all target molecules, HSP70 family and HSP90 are two groups that have been well studied, and therefore, the development of their inhibitors makes great progress. Only a small number of agents, however, have been clinically tested in recruited patients. As a result, more clinical studies are warranted for the establishment of the relationship between the HSP70 family, alongside the HSP90 molecule, and prostate cancer treatment.
Effect of Fe and C Contents on the Microstructure and High-Temperature Mechanical Properties of IN625 Alloy Processed by Laser Powder Bed Fusion
Authors: Kreitcberg Alena , Brailovski Vladimir
Published: September 2022

Two alloys with different Fe and C contents were studied to assess the influence of their compositions on the microstructure and mechanical properties of Ni-based Inconel 625 superalloy processed by laser powder bed fusion and subjected to stress relief annealing (870 °C) and a solution treatment (1120 °C). It was concluded that the alloy with a higher Fe content (~4 wt.% as compared to ~1 wt.%) manifests a greater propensity to segregate Nb and Mo elements during printing and form δ phase particles during the stress relief annealing. On the other hand, the alloy with a higher C content (~0.04 wt.% compared to ~0.02 wt.%) exhibits a greater tendency to form M6C carbides during the solution treatment. No effects of the Fe and C content variations on the room temperature mechanical properties were observed. On the contrary, an increase in the C content resulted in a 40% lower high-temperature (760 °C) ductility of the laser powder bed fused and post-processed IN625 alloy, without affecting its strength characteristics.
Coal Ash Enrichment with Its Full Use in Various Areas
Authors: Petropavlovskaya Victoria , Novichenkova Tatiana , Sulman Mikhail , Petropavlovskii Kirill , Fediuk Roman , Amran Mugahed
Published: September 2022

Increasing the percentage of recycling of various industrial waste is an important step towards caring for the environment. Coal ash is one of the most large-tonnage wastes, which is formed as a result of the operation of thermal power plants. The aim of this work is to develop a technology for the complex processing of coal ash. The tasks to achieve this aim are to develop a technology for the complex enrichment and separation of coal ash into components, with the possibility of their use in various applications, in particular: processing the aluminosilicate part as a pozzolanic additive to cement; carbon underburning for fuel briquettes; the iron-containing part for metallurgy and fertilizers. Complex enrichment and separation into components of coal ash were carried out according to the author’s technology, which includes six stages: disintegration, flotation, two-stage magnetic separation, grinding, and drying. The aluminosilicate component has a fairly constant granulometric composition with a mode of 13.56 μm, a specific surface area of 1597.2 m2/kg, and a bulk density of 900 kg/m3. The compressive strength for seven and twenty-eight daily samples when Portland cement is replaced by 15% with an aluminosilicate additive, increases to 30–35%. According to the developed technology, high-calorie fuel briquettes are obtained from underburnt with a density of 1000–1200 kg/m3, a calorific value of 19.5–20 MJ/kg, and an ash content of 0.5–1.5%. The iron-containing component, recovered by two-stage magnetic separation, has the potential to be used in metallurgy as a coking additive, in particular for the production of iron and steel. In addition, an effective micro-fertilizer was obtained from the iron-containing component, which: is an excellent source of minerals; improves the quality of acidic soil; helps soil microorganisms decompose organic matter faster, turning it into elements available to plants; promotes rooting of seedlings; helps to more effectively deal with many pests and diseases. As a result, the complete utilization of coal ash in various applications has been achieved.
Determining the Vapour Resistance of Breather Membrane Adhesive Joints
Authors: Fuglestad Fride Engesland , Andenæs Erlend , Geving Stig , Kvande Tore
Published: September 2022

Due to increasingly stringent requirements, tapes and adhesive joints are a commonly used method to ensure tightness and energy efficiency in modern building envelopes. Previous studies have researched and tested properties such as the strength and tightness of adhesive joints. So far, water vapour resistance has been neglected. This article aims to determine the vapour resistance and shed light on possible consequences of vapour-tight adhesive joints in breather membranes used in roof assemblies. Laboratory measurements of vapour resistance were conducted according to NS-EN ISO 12572:2016, known as the cup method. Eleven products of breather membranes were tested. Results from the laboratory measurements were used to evaluate the impact of vapour-resistant adhesive joints related to the drying of built-in moisture. The simulation programs WUFI 2D and WUFI Mould Index VTT were used to model scenarios for moisture transport and risk for mould growth. Laboratory results show that the vapour resistance of breather membrane adhesive joints varies from 1.1 to 32 m in sd-value. Three of the tested products have a vapour resistance larger than 10 m, while four products have an sd-value less than 2.0 m. The sd-values of the membranes themselves range between 0.027 and 0.20 m. All tested adhesive joints are considerably more vapour tight than the Norwegian recommended value for breather membranes (<0.5 m). However, the mould growth analysis shows that the risk of mould growth is low in most practical cases, except when using adhesive joints with the highest vapour resistance in roofs assembled during autumn.
Effects of the Parent Alloy Microstructure on the Thermal Stability of Nanoporous Au
Authors: Pinna Andrea , Pia Giorgio , Licheri Roberta , Pilia Luca
Published: September 2022

Nanoporous (NP) metals represent a unique class of materials with promising properties for a wide set of applications in advanced technology, from catalysis and sensing to lightweight structural materials. However, they typically suffer from low thermal stability, which results in a coarsening behavior not yet fully understood. In this work, we focused precisely on the coarsening process undergone by NP Au, starting from the analysis of data available in the literature and addressing specific issues with suitably designed experiments. We observe that annealing more easily induces densification in systems with short characteristic lengths. The NP Au structures obtained by dealloying of mechanically alloyed AuAg precursors exhibit lower thermal stability than several NP Au samples discussed in the literature. Similarly, NP Au samples prepared by annealing the precursor alloy before dealloying display enhanced resistance to coarsening. We suggest that the microstructure of the precursor alloy, and, in particular, the grain size of the metal phases, can significantly affect the thermal stability of the NP metal. Specifically, the smaller the grain size of the parent alloy, the lower the thermal stability.
Micromechanisms and Characterization of Low-Velocity Impact Damage in 3D Woven Composites
Authors: Sun Jin , Dai Yunfeng , Huang Linhai , Zhang Diantang , Zhao Junhua
Published: September 2022

Low-velocity impact (LVI) damage of 3D woven composites were experimentally and numerically investigated, considering different off-axis angles and impact energies. The impact responses were examined by LVI tests, and the damage morphology inside the composites was observed by X-ray micro-computed tomography (μ-CT). Yarn-level damage evolution was revealed by developing a hybrid finite element analysis model. The results show that the impact damage has significant directionality determined by the weft/warp orientation of the composites. The damage originates at the bottom of the impacted area and then expands outwards and upwards simultaneously, accompanied by in-plane and out-of-plane stress transfers. The straight-line distributed weft/warp yarns play an important role in bearing loads at the beginning of loading, while the w-shape distributed binder warp yarns gradually absorb impact deformation and toughen the whole structure as the loading proceeds. The effect of directional impact damage on post-impact performance was explored by performing compressing-after-impact (CAI) tests. It is revealed that the CAI properties along principal directions are more sensitive to the low-velocity impact, and the damage mode is significantly affected by the loading direction.
Textured Stainless Steel as a Platform for Black Mg2Si/Si Heterojunction Solar Cells with Advanced Photovoltaic Performance
Authors: Shevlyagin Alexander , Il’yaschenko Vladimir , Kuchmizhak Aleksandr , Mitsai Eugeny , Amosov Andrey , Balagan Semyon , Kulinich Sergei
Published: September 2022

This paper reports on a facile bottom-up method for the direct integration of a silicon (Si)-magnesium silicide (Mg2Si) heterojunction solar cell (HSC) with a textured rear reflector made of stainless steel (SS). Modified wet chemical etching and post processing of SS substrates resulted in the formation of both a rough surface texture and diffusion barrier layer, consisting of magnetite (Fe3O4) with reduced optical reflection. Then, Si, Mg2Si and CaSi2 layers were stepwise thermally evaporated onto the textured SS surface. No traces of Fe and Cr silicide phases were detected by Raman spectroscopy, confirming effective suppression of impurity diffusion from the SS to the upper layers at least at temperatures required for Si deposition, as well as Mg2Si and CaSi2 formation. The obtained black-SS/Fe3O4/Si/Mg2Si/CaSi2 sample preserved, to some extent, its underlying textured morphology and demonstrated an averaged reflection of 15% over the spectral range of 200–1800 nm, while its prototype HSC possessed a wideband photoresponse with a photoelectric conversion efficiency of 7.5% under AM1.5 illumination. Moreover, Si layers deposited alone onto a black-SS substrate demonstrated competitive antireflection properties compared with black Si (b-Si) obtained by traditional top-down etching approaches, and hybrid b-Si/textured-SS structures with a glue-bonded interlayer.
Thermal Conductivity Stability of Interfacial in Situ Al4C3 Engineered Diamond/Al Composites Subjected to Thermal Cycling
Authors: Li Ning , Hao Jinpeng , Zhang Yongjian , Wang Wei , Zhao Jie , Wu Haijun , Wang Xitao , Zhang Hailong
Published: September 2022

The stability of the thermal properties of diamond/Al composites during thermal cycling is crucial to their thermal management applications. In this study, we realize a well-bonded interface in diamond/Al composites by interfacial in situ Al4C3 engineering. As a result, the excellent stability of thermal conductivity in the diamond/Al composites is presented after 200 thermal cycles from 218 to 423 K. The thermal conductivity is decreased by only 2–5%, mainly in the first 50–100 thermal cycles. The reduction of thermal conductivity is ascribed to the residual plastic strain in the Al matrix after thermal cycling. Significantly, the 272 μm-diamond/Al composite maintains a thermal conductivity over 700 W m−1 K−1 after 200 thermal cycles, much higher than the reported values. The discrete in situ Al4C3 phase strengthens the diamond/Al interface and reduces the thermal stress during thermal cycling, which is responsible for the high thermal conductivity stability in the composites. The diamond/Al composites show a promising prospect for electronic packaging applications.
Study on the Performance of Steel Slag and Its Asphalt Mixture with Oxalic Acid and Water Erosion
Authors: Huang Xiaoming , Yan Feng , Guo Rongxin , He Huan
Published: September 2022

The reuse of steel slag, a large-scale solid waste from steel production, has good social and environmental benefits. The application of a steel slag asphalt mixture is mainly hindered by its volume expansion in water. The expansion of steel slag can be inhibited by oxalic acid. The expansion rate and adhesion of steel slag were investigated, and the immersion stability of steel slag and its asphalt mixture was evaluated by water erosion. By means of XRD, XRF, TG, SEM, etc., the influence mechanism of oxalic acid and water erosion on the properties of steel slag and its asphalt mixture was discussed. The results show that oxalic acid can not only inhibit the expansion of steel slag but also improve its crush resistance, with a reduction in the expansion rate of steel slag by 53%. Oxalic acid is able to leach alkaline metal elements, reducing its adhesion with asphalt. After 10 days of water erosion, the rutting stability and bending crack resistance of the treated steel slag mixture decreased by 37% and 43.2%, respectively. Calcium oxalate is generated on the surface of treated steel slag, which improves the surface compactness, effectively inhibits the expansion of steel slag caused by water erosion, and improves the performance of steel slag and its asphalt mixture. Water erosion can accelerate the hydration and shedding of calcium-containing substances on the surface of steel slag, reduce the adhesion of steel slag, and lead to degradation in the performance of steel slag and its asphalt mixture. Oxalic acid is able to effectively inhibit the expansion of steel slag, and the treated steel slag can be used as recycled aggregate in asphalt mixture, effectively solving the problems of road aggregate deficiency and environmental pollution caused by steel slag.
Generation of Abundant Defects in Ferrite Carbon Magnetic Nanomaterials for Eliminating Electromagnetic Interference in Communication
Authors: Yang Peng , Hao Qian , Zhang Junsheng , Liang Fang , Bo Xiaoning , Wang Peifen
Published: September 2022

A series of novel ferrite carbon nanomaterials are considered to obtain the potential advantages in elimination of the electromagnetic interference effects. Herein, the iron nanoparticles coated on amorphous carbon were prepared by facile agar-gel synthesis. Meanwhile, the synergy between carbon supporting and ferrite nanomaterials could be proved to promote the absorption properties. Among all samples, the iron nanoparticles coated on amorphous carbon show the highest microwave absorption properties, achieving the maximum reflection loss (RL) of −14.3 dB at 6 GHz (5.5-milimeter thickness), and the bandwidths over −10 dB (90% absorption) was 2.5 GHz. Combining analysis results, it is confirmed that the as-prepared iron nanoparticles have the highest surface area, homogeneous distribution, abundant defect, and well-defined pore structure, which could significantly affect the absorption properties at 6 GHz. Furthermore, the abundant defects derived from the interface were the essential reason for the improved absorption properties. Overall, it provided a new strategy to design an effective method to absorb nanomaterials for the elimination of electromagnetic interference, especially the coordination of metal species and carbon supporting.
Cation Valences and Multiferroic Properties of EuTiO3 Co-Doped with Ba and Transition Metals of Co/Ni
Authors: Lin Tzu-Chiao , Qi Xiaoding
Published: September 2022

Eu1−xBaxTi1−yMyO3 (M = Co or Ni) was sintered at 1400 °C under a reduction atmosphere. X-ray photoelectron spectroscopy revealed the mixed valences of Eu2+/Eu3+ and Ti4+/Ti3+ in EuTiO3 and Eu0.7Ba0.3TiO3, as well as some oxygen vacancies required to keep the charge neutrality. The co-doping of Co2+/Ni2+ in Eu0.7Ba0.3TiO3 resulted in the disappearance of oxygen vacancies, as a result of a reduction in Ti3+ numbers and an increase in Eu3+ numbers. On the other hand, Ba2+ doping led to an increased lattice parameter due to its larger ionic size than Eu2+, whereas the Co2+/Ni2+ co-doping resulted in smaller lattice parameters because of the combined effects of ionic size and variation in the oxygen-vacancy numbers. Eu0.7Ba0.3TiO3 exhibited a clear ferroelectricity, which persisted in the Co2+/Ni2+ co-doped samples until the doping levels of y = 0.05 and 0.10, respectively. Eu0.7Ba0.3TiO3 remained to be antiferromagnetic with a reduced transition temperature of 3.1 K, but co-doping of Co2+/Ni2+ turned the samples from antiferromagnetic to ferromagnetic with transition temperatures of 2.98 K and 2.72 K, respectively. The cause for such a transition could not be explained by the larger lattice volume, oxygen vacancies and mixed valences of Eu2+/Eu3+, which were proposed in previous works. Instead, it was more likely to arise from a large asymmetric distortion of the Eu–O polyhedron introduced by the aliovalent doping, which promotes the admixture of Eu 5d and 4f states.
Intramedullary Skeletal Distraction Robot: Novel Design and Optimization of Implantable Lengthening Nail
Authors: Lee ShiKeat , Nie Zhenguo , Xu Handing , Hu Kai , Lin Hanwei , Xie Fugui , Liu Xin-jun
Published: September 2022

Leg Length Discrepancy (LLD) is a critical problem which not only impacts the quality of life but also causes other physical ailments such as limping and severe back pain. Most people had a non-negligible difference in the length of their two legs, and 0.1% of the population with differences of 20 mm or more are diagnosed as a difference in limb length. The Ilizarov external fixator is commonly used in treating LLD as conventional therapeutic equipment, but often causes serious complications that cannot be prevented. Therefore, intramedullary leg-lengthening treatment has become popular in distraction osteogenesis to eliminate extracorporeal surgery. This paper presents a study on the design and optimization of a novel electromagnetic-driven Intramedullary Skeletal Distraction Robot (ISDR) with robust mechanical stiffness and surplus electromagnetic driving force. Compared with PRECICE, the split structure of ISDR eases the optimal design and manufacturing difficulties to strengthen mechanical stiffness, and the electromagnetic configuration allows improving the distraction force by adjusting the Permanent Magnet Brushless Direct Current (PMBLDC) motor parameters. ISDR, which is implanted in the medullary cavity, has the Von-Mises stress of 952.15 MPa, and the first mode of natural frequency is 28.823 Hz indicating that it can withstand the load during the walking gait phases. On the other hand, the ISDR distraction force encounters resistance from muscle fibers, and an average driving torque of 9 Nmm ensures its distraction. Based on the results, ISDR is proven secure and reliable during and after leg-lengthening treatment, which can significantly reduce lifestyle disruption and medical complications.
Intelligent Fault Diagnosis for Inertial Measurement Unit through Deep Residual Convolutional Neural Network and Short-Time Fourier Transform
Authors: Xiang Gang , Miao Jing , Cui Langfu , Hu Xiaoguang
Published: September 2022

An Inertial Measurement Unit (IMU) is a significant component of a spacecraft, and its fault diagnosis results directly affect the spacecraft’s stability and reliability. In recent years, deep learning-based fault diagnosis methods have made great achievements; however, some problems such as how to extract effective fault features and how to promote the training process of deep networks are still to be solved. Therefore, in this study, a novel intelligent fault diagnosis approach combining a deep residual convolutional neural network (CNN) and a data preprocessing algorithm is proposed. Firstly, the short-time Fourier transform (STFT) is adopted to transform the raw time domain data into time–frequency images so the useful information and features can be extracted. Then, the Z-score normalization and data augmentation strategies are both explored and exploited to facilitate the training of the subsequent deep model. Furthermore, a modified CNN-based deep diagnosis model, which utilizes the Parameter Rectified Linear Unit (PReLU) as activation functions and residual blocks, automatically learns fault features and classifies fault types. Finally, the experiment’s results indicate that the proposed method has good fault features’ extraction ability and performs better than other baseline models in terms of classification accuracy.
New Hermite–Hadamard and Ostrowski-Type Inequalities for Newly Introduced Co-Ordinated Convexity with Respect to a Pair of Functions
Authors: Ali Muhammad Aamir , Wannalookkhee Fongchan , Budak Hüseyin , Etemad Sina , Rezapour Shahram
Published: September 2022

In both pure and applied mathematics, convex functions are used in many different problems. They are crucial to investigate both linear and non-linear programming issues. Since a convex function is one whose epigraph is a convex set, the theory of convex functions falls under the umbrella of convexity. However, it is a significant theory that affects practically all areas of mathematics. In this paper, we introduce the notions of g,h-convexity or convexity with respect to a pair of functions on co-ordinates and discuss its fundamental properties. Moreover, we establish some novel Hermite–Hadamard- and Ostrowski-type inequalities for newly introduced co-ordinated convexity. Additionally, it is presented that the newly introduced notion of the convexity and given inequalities are generalizations of existing studies in the literature. Lastly, we look at various mathematical examples and graphs to confirm the validity of the newly found inequalities.
Mathematical Modeling of Gas Hydrates Dissociation in Porous Media with Water-Ice Phase Transformations Using Differential Constrains
Authors: Alekseeva Natalia , Podryga Viktoriia , Rahimly Parvin , Coffin Richard , Pecher Ingo
Published: September 2022

2D numerical modeling algorithms of multi-component, multi-phase filtration processes of mass transfer in frost-susceptible rocks using nonlinear partial differential equations are a valuable tool for problems of subsurface hydrodynamics considering the presence of free gas, free water, gas hydrates, ice formation and phase transitions. In this work, a previously developed one-dimensional numerical modeling approach is modified and 2D algorithms are formulated through means of the support-operators method (SOM) and presented for the entire area of the process extension. The SOM is used to generalize the method of finite difference for spatially irregular grids case. The approach is useful for objects where a lithological heterogeneity of rocks has a big influence on formation and accumulation of gas hydrates and therefore it allows to achieve a sufficiently good spatial approximation for numerical modeling of objects related to gas hydrates dissociation in porous media. The modeling approach presented here consistently applies the method of physical process splitting which allows to split the system into dissipative equation and hyperbolic unit. The governing variables were determined in flow areas of the hydrate equilibrium zone by applying the Gibbs phase rule. The problem of interaction of a vertical fault and horizontal formation containing gas hydrates was investigated and test calculations were done for understanding of influence of thermal effect of the fault on the formation fluid dynamic.
Dynamics of a Stochastic HIV Infection Model with Logistic Growth and CTLs Immune Response under Regime Switching
Authors: Hu Lin , Nie Lin-Fei
Published: September 2022

Considering the influences of uncertain factors on the reproduction of virus in vivo, a stochastic HIV model with CTLs’ immune response and logistic growth was developed to research the dynamics of HIV, where uncertain factors are white noise and telegraph noise. which are described by Brownian motion and Markovian switching, respectively. We show, firstly, the existence of global positive solutions of this model. Further, by constructing suitable stochastic Lyapunov functions with regime switching, some sufficient conditions for the existence and uniqueness of the stationary distribution and the conditions for extinction are obtained. Finally, the main results are explained by some numerical examples. Theoretical analysis and numerical simulation show that low-intensity white noise can maintain the persistence of the virus, and high intensity white noise can make the virus extinct after a period of time with multi-states.
Thyroid Nodule Segmentation in Ultrasound Image Based on Information Fusion of Suggestion and Enhancement Networks
Authors: Nguyen Dat Tien , Choi Jiho , Park Kang Ryoung
Published: September 2022

Computer-aided diagnosis/detection (CADx) systems have been used to help doctors in improving the quality of diagnosis and treatment processes in many serious diseases such as breast cancer, brain stroke, lung cancer, and bone fracture. However, the performance of such systems has not been completely accurate. The key factor in CADx systems is to localize positive disease lesions from the captured medical images. This step is important as it is used not only to localize lesions but also to reduce the effect of noise and normal regions on the overall CADx system. In this research, we proposed a method to enhance the segmentation performance of thyroid nodules in ultrasound images based on information fusion of suggestion and enhancement segmentation networks. Experimental results with two open databases of thyroid digital image databases and 3DThyroid databases showed that our method resulted in a higher performance compared to current up-to-date methods.