bluuebunny/crossref_metadata_2025 huggingface dataset:
3D-EddyNet: A Novel Approach for Identifying Three-Dimensional Morphological Features of Mesoscale Eddies in the Ocean
Authors: Feng Pufei , Fu Zhiyi , Hu Linshu , Wu Sensen , Wang Yuanyuan , Zhang Feng
Published: September 2023

Mesoscale eddies are characterized by swirling currents spanning from tens to hundreds of kilometers in diameter three-dimensional attributes holds paramount significance in driving advancements in both oceanographic research and engineering applications. Nonetheless, a notable absence of models capable of adeptly harnessing the scarcity of high-quality annotated marine data, to efficiently discern the three-dimensional morphological attributes of mesoscale eddies, is evident. To address this limitation, this paper constructs an innovative deep-learning-based model termed 3D-EddyNet, tailored for the precise identification and visualization of mesoscale eddies. In contrast to the prevailing 2D models that remain confined to surface-level data, 3D-EddyNet takes full advantage of three-dimensional convolutions to capture the essential characteristics of eddies. It is specifically tailored for recognizing spatial features within mesoscale eddies, including parameters like position, radius, and depth. The combination of dynamic convolutions and residual networks effectively enhances the model’s performance in a synergistic manner. The model employs the PReLU activation function to tackle gradient vanishing issues and improve convergence rates. It also addresses the challenge of foreground–background imbalance through cross-entropy functions. Additionally, to fine-tune the model’s effectiveness during the training phase, techniques such as random dropblock and batch normalization are skillfully incorporated. Furthermore, we created a training dataset using HYCOM data specifically from the South China Sea region. This dataset allowed for a comprehensive analysis of the spatial-temporal distribution and three-dimensional morphology of the eddies, serving as an assessment of the model’s practical effectiveness. The culmination of this analysis reveals an impressive 20% enhancement over 3D-UNet in detection accuracy, coupled with expedited convergence speed. Notably, the results obtained through our detection using empirical data align closely with those obtained by other scholars. The mesoscale eddies within this specific region unveil a discernible northeast-to-southwest distribution pattern, categorized into three principal morphological classifications: bowl-shaped, olive-shaped, and nearly cylindrical, with the bowl-shaped eddies prominently dominating.
Platinum and Palladium Accumulation in Edible Mushroom Boletus aereus Bull. Growing in Unpolluted Soils of Sicily Region (Italy)
Authors: Alaimo Maria Grazia , Varrica Daniela
Published: September 2023

Human exposure to certain metals occurs indirectly through diet. This study was conducted to determine the content of Pt and Pd in fruiting bodies of Boletus aereus Bull. collected from several wooded areas of Sicily with different substrates (sedimentary and volcanic) with limited anthropogenic influence. Determinations were performed by coupled plasma-mass spectrometry (ICP–MS) to quantify Pt and Pd. The concentrations of investigated Pt and Pd in mushroom samples ranged from 0.31 to 3.09 ng g−1 for palladium and 0.21 to 4.22 ng g−1 for platinum. The results of the present study suggest that commonly consumed Boletus aereus mushrooms do not accumulate significant levels of Pt and Pd as demonstrated by bioconcentration factor (BCF) values, and their content is lower than in other food products. Additionally, based on the calculated daily intake rates of Pt and Pd, it can be concluded that occasional consumption of fruiting bodies of B. aereus collected in Sicily is safe. The proposed methodological approach appears to be fully adequate for the reliable quantification of Pt and Pd. The data obtained in this investigation confirm that mushrooms are probative of a significant portion of the total exposure to PGEs due to the diet.
Patient Perspectives of Barriers and Facilitators for the Uptake of Pharmacogenomic Testing in Veterans Affairs’ Pharmacogenomic Testing for the Veterans (PHASER) Program
Authors: Melendez Karina , Gutierrez-Meza Diana , Gavin Kara L. , Alagoz Esra , Sperber Nina , Wu Rebekah Ryanne , Silva Abigail , Pati Bhabna , Voora Deepak , Hung Allison , Roberts Megan C. , Voils Corrine I.
Published: September 2023

We applied implementation science frameworks to identify barriers and facilitators to veterans’ acceptance of pharmacogenomic testing (PGx), which was made available as a part of clinical care at 25 VA medical centers. We conducted 30 min interviews with veterans who accepted (n = 14), declined (n = 9), or were contemplating (n = 8) PGx testing. Six team members coded one transcript from each participant group to develop the codebook and finalize definitions. Three team members coded the remaining 28 transcripts and met regularly with the larger team to reach a consensus. The coders generated a matrix of implementation constructs by testing status to identify the similarities and differences between accepters, decliners, and contemplators. All groups understood the PGx testing procedures and possible benefits. In the decision-making, accepters prioritized the potential health benefits of PGx testing, such as reducing side effects or the number of medications. In contrast, decliners prioritized the possibilities of data breach or the negative impact on healthcare insurance or Veterans Affairs benefits. Contemplators desired to speak to a provider to learn more before making a decision. Efforts to improve the clarity of data security and the impact on benefits may improve veterans’ abilities to make more informed decisions about whether to undergo PGx testing.
Measuring Value in Development with Advanced Real Options for International Sequential Acquisitions
Authors: Čirjevskis Andrejs
Published: September 2023

Even though the application of real options theory in international business research has increased substantially, the measurement of collaborative synergies in international sequential acquisition by means of advanced real options is still the theoreticall gap which needs to be filled by new research and promising area for empirical research. This paper moves the field forward and highlights the fact that strategic synergies can be considered as compound real options for growth that are opened by an international sequential acquisition and, thus, add market value to the acquirer. Our research is presented as a theory-building inductive case-based study. This paper aims to integrate sequential compound real options with real options that have changing volatility in order to evaluate collaborative tacit synergies (a value in development) of sequential international acquisitions; thus, it contributes to corporate finance, international business, and strategic management theory with a fresh evaluation of the applications of advanced real options.
An Empirical Study of User Adoption of Cryptocurrency Using Blockchain Technology: Analysing Role of Success Factors like Technology Awareness and Financial Literacy
Authors: Kumari Vandana , Bala Pradip Kumar , Chakraborty Shibashish
Published: September 2023

The study aims to investigate how an individual’s technology awareness, subjective financial literacy and personal innovativeness characteristics impact the intention to use blockchain-based digital currencies such as cryptocurrency. The UTAUT 2 (Unified Theory of Acceptance and Use of Technology 2) model is extended with crucial constructs to develop the conceptual model. A total of 312 responses are analysed using Covariance-Based Structural Equation Modelling (CB-SEM). The moderation effects are assessed using multi-group analysis. The findings show a significant moderating effect of technology awareness and subjective financial literacy on the relationship between performance expectancy (PE) and behavioural intention to use cryptocurrency (BI). It further identified that performance expectancy (PE) mediates personal innovativeness (PI) and usage intentions (BI). The study adds to the growing literature of digital currency adoption by focusing on individual innovativeness, technology awareness and financial literacy. It also proposes a research model that can be generalised for new-age consumer-based financial technology adoption.
Historical Memory as an Effective and Useful Tool for Proper Land Use Planning: Lessons Learnt from Some Italian Cases
Authors: Luino Fabio , Gizzi Fabrizio Terenzio , Palmieri Walter , Porfido Sabina , Turconi Laura
Published: September 2023

Many Italian cities and towns have been affected by geological or geohydrological processes. However, due to the loss of historical memory, lessons of the past have been ignored; new urbanized areas have expanded into the same zones where damage and casualties occurred in the past. Despite current practices, researchers are showing how historical data can be among the most valid tools for identifying the most affected and hazardous areas. When the completeness and quality of historical sources are sufficiently high, we can make useful statistical inferences regarding the spatiotemporal variations of natural processes. This information is of great importance for land use planning, as it makes us able to rely not only on the current state of the investigated areas but also on their dynamic evolutionary framework over time. In this article, we present a chronological review of past Italian works describing the occurrence of natural extreme events making use of historical data. Then, we present some Italian case studies in which the awareness of hazards gained by paying attention to past information would have ensured better management of the risk for the benefit of public safety. Finally, the authors stress the need to safeguard, manage, and enhance the large collection of historical data that constitutes Italy’s heritage.
Assessing Soil Organic Carbon Pool for Potential Climate-Change Mitigation in Agricultural Soils—A Case Study Fayoum Depression, Egypt
Authors: Abdellatif Mostafa A. , Hassan Farag O. , Rashed Heba S. A. , El Baroudy Ahmed A. , Mohamed Elsayed Said , Kucher Dmitry E. , Abd-Elmabod Sameh Kotb , Shokr Mohamed S. , Abuzaid Ahmed S.
Published: September 2023

It is essential to assess the soil organic carbon pool (SOCP) in dry environments to apply appropriate management techniques that address sustainable development. A significant opportunity for sustaining agricultural output and reducing climate change is the storage of soil organic carbon in agricultural soil. The goal of this study was to measure the spatial variability of SOCP content, and determine the effects of soil texture, changes in land use, and land cover on SOCP in surface soil samples. The study additionally investigated the relationships between SOCP and other characteristics, including the normalized vegetation index (NDVI) and land surface temperature (LST), as well as the effects of increasing soil organic carbon on the amount of greenhouse gases. To accomplish this goal, 45 soil surface samples were collected to a depth of 30 cm at the Fayoum depression in Egypt, and analyzed. The soil samples were representative of various soil textures and land uses. The average SOCP concentration in cultivated regions is 32.1 and in bare soils it is 6.5 Mg ha−1, with areas of 157,112.94 and 16,073.27 ha, respectively. According to variances in soil textures, sandy soils have the lowest SOCP (1.8 Mg ha−1) and clay loam soils have the highest concentrations (49 Mg ha−1). Additionally, fruit-growing regions have the greatest SOCP values and may therefore be better suited for carbon sequestration. The overall average SOCP showed 32.12 Mg C ha−1 for cultivated areas. A rise in arable land was accompanied by a 112,870.09 Mg C rise in SOCP. With an increase in soil organic carbon, stored carbon dioxide emissions (greenhouse gases) would be reduced by 414,233.24 Mg CO2. We should consider improving fertilization, irrigation methods, the use of the multiple cropping index, decreasing desertion rates, appropriate crop rotation, and crop variety selection. The research highlights the significance of expanding cultivated areas towards sustainable carbon sequestration and the climate-change-mitigation potential.
An Overview of Population Dynamics in Romanian Carpathians (1912–2021): Factors, Spatial Patterns and Urban–Rural Disparities
Authors: Muntele Ionel , Istrate Marinela , Athes Haralambie , Bănică Alexandru
Published: September 2023

Our paper aims to analyze the tendencies of population dynamics in the area of the Romanian Carpathians, as well as the factors and spatial processes that can explain the disparities, discontinuities and tensions of demographic evolution. Starting from the hypothesis of an existing set of well-known particularities of the three areas of the Romanian Carpathians (Eastern, Southern and Western), in close connection with the specific manner of using natural and human resources of each area, the main objective of our study is to pinpoint the significant aspects of depopulation and population redistribution. The database was established resorting to censuses from 1912 to the present time. Coupled with a typology of population evolution, a regression analysis was used to assess the relationship between population size changes through time and other variables. The results highlight the contrast between the sustained dynamic in the first part of our study period and the subsequent decline, particularly in the case of establishments specialized in industrial extraction activities. Despite all this, clear signs and tendencies of revitalization and dynamism can be observed, especially where urban and rural settlements are well adapted to the natural environment and can benefit from a significant tourism potential.
Understanding Recessive Transition of Cultivated Land Use in Jilin Province, China (1990–2020): From Perspective of Productive-Living-Ecological Functions
Authors: Wang Lingzhi , Liang Anqi , Li Xinyao , Jiang Chengge , Wu Junjie , Omrani Hichem
Published: September 2023

Jilin Province is an important commercial grain production base in northeast China, and it has seen significant transition in cultivated land use in recent years. This study constructed a measurement system for the recessive transition of cultivated land use in Jilin Province based on the perspective of “three-function synergy” (productive, living, and ecological functions). It discussed the temporal and spatial evolution characteristics of the recessive transition of cultivated land use from 1990 to 2020, identified the turning point of the cultivated land transition trend, and built a model of recessive transition of cultivated land in Jilin Province. After analyzing the results, we came to the following conclusions: (1) The turning point of the “three-function synergy” of the recessive morphology of cultivated land in Jilin Province occurred earlier than the mutation point of the recessive transition of cultivated land, and there was a certain temporality in the recessive transition of cultivated land compared with the functional change of cultivated land; (2) the degree of recessive transition of cultivated land in Jilin Province showed a spatial distribution characteristic of being higher in the west and lower in the east; (3) the recessive transition of cultivated land use in Jilin Province could be divided into transition stages characterized by “low stage slow rise period”, “middle stage significant increase period”, and “high stage steady growth period”; (4) Jilin Province should adopt differentiated and diversified management of cultivated land to achieve a comprehensive management model that emphasizes quantity, quality, and ecology.
The Impact of Farmland Management Scale on Carbon Emissions
Authors: Bai Jing , Liu Jun , Ma Libang , Zhang Wenbo
Published: September 2023

In rural China, the conversion between fine-grained farmland and large-scale farmland is a widespread phenomenon, changes in the size of farmland can have an impact on agricultural carbon emissions. Based on the agricultural panel data of Gansu Province for 2000–2020, taking the scale of agricultural land management as the breakthrough point and the consumption intensity of agricultural materials as the intermediary factor, this paper discusses the driving mechanism of agricultural carbon emissions by the scale of agricultural land management. The results including: (1) From the perspective of the intermediary effect, large-scale farmers pay more attention to input efficiency of chemicals such as fertilizers than small-scale farmers, which can effectively promote the development of low-carbon agriculture. (2) A “U-shaped” relationship existed between agricultural land management scale and agricultural carbon emissions. The agricultural carbon emissions were the lowest when agricultural land management scale in Gansu was 0.608 hm2/person. (3) The carbon emission intensity reached its peak when the scale of farmland management in the Hexi region was 0.143 hm2/person. The optimal scale of farmland management in the Longdong and Longnan regions was 0.143 and 0.348 hm2/person, respectively, Longzhong and Gannan regions was all showed complete intermediary effects.
The Spatial Pattern Evolution of Rural Settlements and Multi-Scenario Simulations since the Initiation of the Reform and Opening up Policy in China
Authors: Sheng Shuangqing , Lian Hua
Published: September 2023

Since the inception of China’s reform and opening-up policy, the rapidly advancing process of urbanization and the primacy accorded to urban development policies have imparted increasingly profound ramifications on rural domains. Nonetheless, antecedent research has predominantly fixated on urban sprawl, overlooking the spatial metamorphosis of rural settlements and the prospective developmental trajectories within the policy paradigm. Consequently, this inquiry endeavors to scrutinize the evolution of the spatial configuration of rural settlements in She County from the advent of reform and opening-up (1980–2020) utilizing remote sensing data. In tandem, through scenario delineation and the utilization of the CLUE-S model, it aspires to prognosticate the evolving trends in the spatial arrangements of rural settlements in She County by 2035. The empirical findings divulge that (1) The temporal progression of rural settlement spatial configurations in She County over the preceding four decades can be delineated into two discernible phases. From 1980 to 2000, alterations in the number, extent, and spatial morphological attributes of rural settlements remained circumscribed. While the count of rural settlements registered a diminution (by 3), the aggregate extent experienced a marginal augmentation (by 8.45%), concomitant with a gradual gravitation towards regular boundaries, manifesting a stochastic distribution throughout the investigation expanse. Conversely, from 2000 to 2020, the quantity and extent of rural settlements in She County underwent a precipitous augmentation (92 and 36.37%, respectively), characterized by irregular peripheries. (2) The CLUE-S model achieved an overall precision of 0.929, underscoring its applicability in emulating fluctuations in rural settlements. (3) Within the new-type urbanization scenario, the cumulative expanse of rural settlements witnessed a decline of 35.36% compared to the natural development scenario, marked by substantial conversions into grassland and urban land usage. Furthermore, orchestrated planning and directive measures have propelled the consolidation of rural settlements in She County, engendering a more equitable and standardized layout. Under the aegis of the ecological conservation scenario, the total rural settlement area recorded a 0.38% reduction vis-à-vis the natural development scenario, primarily entailing competitive coexistence with arable land, grassland, and urban land usage in spatial terms.
Anti-Inflammatory and Anticancer Effects of Anticoagulant Therapy in Patients with Malignancy
Authors: Russo Vincenzo , Falco Luigi , Tessitore Viviana , Mauriello Alfredo , Catapano Dario , Napolitano Nicola , Tariq Moiz , Caturano Alfredo , Ciccarelli Giovanni , D’Andrea Antonello , Giordano Antonio
Published: September 2023

Optimizing the anticoagulation therapy is of pivotal importance in patients with a malignant tumor, as venous thromboembolism (VTE) has become the second-leading cause of death in this population. Cancer can highly increase the risk of thrombosis and bleeding. Consequently, the management of cancer-associated VTE is complex. In recent years, translational research has intensified, and several studies have highlighted the role of inflammatory cytokines in cancer growth and progression. Simultaneously, the pleiotropic effects of anticoagulants currently recommended for VTE have emerged. In this review, we describe the anti-inflammatory and anticancer effects of both direct oral anticoagulants (DOACs) and low-molecular-weight heparins (LWMHs).
Understanding the Male Perspective: Evaluating Quality of Life and Psychological Distress in Serbian Men Undergoing Infertility Treatment
Authors: Čegar Bojan , Šipetić Grujičić Sandra , Bjekić Jovana , Vuksanović Aleksandar , Bojanić Nebojša , Bartolović Daniela , Jovanović Darko , Zeković Milica
Published: September 2023

The experience of an infertility diagnosis and treatment imposes a profound burden on affected individuals, encompassing not only physical and medical aspects but also a plethora of psychological, social, and emotional factors. By employing a multimodal assessment featuring validated self-report questionnaires, physical measurements, and clinical records, the present study aimed to explore the quality of life and psycho-emotional distress of men undergoing infertility treatment in Serbia, thereby addressing the dearth of research on the underrepresented male perspective in this domain. Findings revealed diverse semen abnormalities among participants (n = 96, average age 37.69 ± 5.72), with significant associations between longer treatment durations and reduced sperm motility. The observed rates of men surpassing predetermined DASS-42 questionnaire thresholds for depression, anxiety, and stress in the analyzed cohort were 13.54%, 11.46%, and 22.92%, respectively. Summary scores in conceptual areas comprised in the SF-36 questionnaire ranged from 49.00 ± 6.25 for the mental health dimension to 90.16 ± 17.75 obtained in the physical functioning subscale. Patients with a longer treatment duration demonstrated lower scores in the role emotional domain, indicative of a less favorable emotional state. Expectedly, inverse correlations were found between the SF-36 mental health score and DASS-42 subscales. By addressing the existing knowledge gap and highlighting the unique needs of infertile men, the finding of this study may contribute to a more inclusive and holistic approach to infertility research and management.
Significant Improvement in Wear Resistance of CoCrFeNi High-Entropy Alloy via Boron Doping
Authors: Zhang Haitao , Miao Junwei , Wang Chenglin , Li Tingju , Zou Longjiang , Lu Yiping
Published: September 2023

CoCrFeNi high-entropy alloy (HEA) exhibits excellent mechanical properties but relatively poor wear resistance. In particular, when the load reaches a certain level and the deformation mechanism of the CoCrFeNi HEA changes, the formation of shear bands leads to a significant increase in wear rate. Although numerous studies have been conducted on alloying strategies to improve the wear resistance of alloys, there is still limited research on the influence of deformation mechanism adjustment on wear resistance. Therefore, in order to fill this research gap, this study aims to use boron doping to regulate the deformation mechanism and successfully improve the wear resistance of CoCrFeNi HEA by 35 times. By observing the subsurface microstructure, the mechanism behind the significant improvement in wear resistance was further revealed. The results indicate that the reduction of shear bands and the formation of nanostructured mixed layers significantly improve wear resistance. The proposed strategy of boron doping to change the deformation mechanism and improve wear resistance is expected to provide new enlightenment for the development of wear-resistant HEAs.
A Finite Element Analysis of Cold Deep Drawing of Al Alloy Considering Friction Condition and Corner Design of Plunger
Authors: Bahanan Warda , Fatimah Siti , Go Jae Hoon , Oh Jeong Moo , Kim Min Jun , Kim Myung Jae , Kang Jee-Hyun , Kim Dong-Ju , Widiantara I Putu , Ko Young Gun
Published: September 2023

This study presents an innovative methodology that integrates experimental investigations with finite element simulations to ascertain the validity and reliability of Al 3104 sheet metals during cold deep drawing. Focusing on the nose plunger radius and coefficient of friction at a fixed speed and temperature (25 °C), five different scenarios are utilized to simulate the optimum parameters. Through a detailed strain history analysis from simulations, the initiation of bending in the corner is precisely identified, with a validation achieved through a strain analysis obtained via digital image correlation. The study delves into the influence of strain and strain rate on the microstructures and mechanical properties near the corner region. It highlights the superior efficacy of strain-based criteria in characterizing deformation behavior. Notably, the strain distributions during the onset of bending and severe bending align remarkably well with the established simulation data. In brief, this work introduces an integrated approach that harmoniously combines computational simulations with empirical observations, resulting in significant ramifications for precisely comprehending and forecasting the strain distribution in metal forming operations.
A Fractional Creep Constitutive Model Considering the Viscoelastic–Viscoplastic Coexistence Mechanism
Authors: Zhao Jia , Zhao Weigang , Xie Kaize , Yang Yong
Published: September 2023

In order to improve the accuracy and universality of the nonlinear viscoelastic-plastic mechanical behavior characterization method of asphalt mixture, a new criterion for the division of the creep process of materials was established based on the strain yield characteristics, and the coexistence mechanism of Viscoelastic–Viscoplastic strain was proposed in the subsequent yield phase; then, a viscoelastic element was constructed in the form of a parallel connection of two fractional viscoelastic elements based on fractional calculus theory, and its mathematical equations were derived; with novel viscoelastic elements, a constitutive model characterizing the whole creep process of asphalt mixtures was developed and its analytical expression was derived. The laboratory short-term creep test of Cement and Asphalt Mortar (CA mortar) and the simulation test data of asphalt mixtures from the references were used to verify the constitutive model. The results show that the creep constitutive model of asphalt mixture established in this paper has excellent fitting accuracy for different phases of the creep process of asphalt mixture under different stress levels, where the minimum fitting correlation values R2 for CA mortar, asphalt mixture (applied to pavement engineering), and asphalt sand are 0.9976, 0.981, and 0.979, respectively. Therefore, this model can be used to provide a theoretical reference for the study of the characterization of the mechanical behavior of asphalt materials.
Mechanical Evaluation of PET-G 3D-Printed Wrist-Hand Orthosis: An Integrated Experimental and Numerical Approach
Authors: Łukaszewski Krzysztof , Raj Ratnesh , Karwasz Anna
Published: September 2023

Limb injuries frequently necessitate orthotic bracing, and the utilization of material extrusion (MEX) additive manufacturing (AM) or 3D printing offers a rapid and cost-effective means of producing orthoses. These characteristics are highly sought after in today’s orthotic market. The study focused on the mechanical strength analysis of the wrist-hand orthosis (WHO) made of PET-G filament. Experimental testing and simulation were employed to assess the properties of individualized wrist orthoses fabricated through the MEX AM process. Standard three-point bending samples were manufactured using PET-G filament on a low-cost MEX 3D printer, alongside orthotic fragments and complete orthosis. Experimental testing was performed using a universal testing machine, and results were juxtaposed with those from a finite element simulation model created in the Abaqus environment. This comprehensive research approach facilitates the comparison of the modulus of elasticity of the fabricated components, enabling a comparison between the mechanical properties of the complete wrist-hand orthosis (WHO) product and those of a conventional bending sample.
Current Trends and Promising Electrode Materials in Micro-Supercapacitor Printing
Authors: Simonenko Tatiana L. , Simonenko Nikolay P. , Gorobtsov Philipp Yu. , Simonenko Elizaveta P. , Kuznetsov Nikolay T.
Published: September 2023

The development of scientific and technological foundations for the creation of high-performance energy storage devices is becoming increasingly important due to the rapid development of microelectronics, including flexible and wearable microelectronics. Supercapacitors are indispensable devices for the power supply of systems requiring high power, high charging-discharging rates, cyclic stability, and long service life and a wide range of operating temperatures (from −40 to 70 °C). The use of printing technologies gives an opportunity to move the production of such devices to a new level due to the possibility of the automated formation of micro-supercapacitors (including flexible, stretchable, wearable) with the required type of geometric implementation, to reduce time and labour costs for their creation, and to expand the prospects of their commercialization and widespread use. Within the framework of this review, we have focused on the consideration of the key commonly used supercapacitor electrode materials and highlighted examples of their successful printing in the process of assembling miniature energy storage devices.
The Influence of Ultrasonic Activation on Microstructure, Phase Transformation and Mechanical Properties of Porous Ni-Ti Shape Memory Alloys via Self-Propagating High-Temperature Synthesis
Authors: Maashaa Dovchinvanchig , Purevdagva Enkhtsetseg , Rubanik Vasili V. , Rubanik Vasili V.
Published: September 2023

Porous Ni-Ti shape memory alloys (SMAs) have been widely studied in biomedical and engineering applications. Porous Ni-Ti SMAs were obtained via self-propagating high-temperature synthesis (SHS), and their microstructure, phase transformation, and mechanical properties were investigated. This article presents the results of a study of changes in the microstructure, phase transformation, and mechanical properties of porous Ni-Ti SMAs when Ni and Ti metal powders were preliminarily subjected to ultrasonic activation at various periods. It was determined that the porosity of the obtained alloy samples was 62–68 vol%. The microstructure was composed of the main matrix Ni-Ti phase and the accompanying Ti and Ti2-Ni phases. The results show that the hardness 34.1–86.8 HB and elastic modulus 4.2–10.8 GPa increased with an increase in the ultrasonic activation time of the samples. The phase transformation temperature of the Ni-Ti shape memory alloy remained almost unchanged under the influence of ultrasonic treatment.
The Impact of Temperature Conditions on the Manufacturing Process and Mechanical Behavior of Beverage Can Ends during Operation
Authors: Kokoszka Paweł , Milenin Andrij
Published: September 2023

This article investigates the impact of temperature regimes, corresponding to various climatic zones, on the manufacturing process and operation of beverage can ends made of aluminum alloy AA5182. The production process of aluminum beverage can ends involves multiple steps, including melting, rolling, and stamping, where different temperatures can influence both the production process and the properties of the final product. Furthermore, the mechanical behavior of the final product is affected by the aging process of alloy AA5182, which progresses at varying rates depending on the temperature conditions during storage. The objective of this study is to simulate the production process under various climatic conditions using the finite element method (FEM) and experimentally investigate the dependence of the strength of alloy AA5182 can ends on storage time and temperature. The findings of the study reveal that, under temperature conditions corresponding to warmer climates, the punching force can be reduced by approximately 15% compared to production in colder climates. Additionally, the strength of the finished can exhibits a decrease of about 10% during a month of storage in a warm climate, while no significant decrease was observed in colder climates. These results hold practical significance for the beverage production industry, as the manufacturing and operation of beverage cans are localized in diverse climatic zones.
Effect of Trap Behavior on the Reliability Instability of Metamorphic Buffer in InAlAs/InGaAs MHEMT on GaAs
Authors: Shin Ki-Yong , Shin Ju-Won , Amir Walid , Chakraborty Surajit , Shim Jae-Phil , Lee Sang-Tae , Jang Hyunchul , Shin Chan-Soo , Kwon Hyuk-Min , Kim Tae-Woo
Published: September 2023

Our investigation focused on assessing the influence of the metamorphic buffer in metamorphic high-electron-mobility transistors (MHEMT) that were grown on GaAs substrates. While an MHEMT exhibited elevated off-state current levels, its direct current (DC) and radio frequency (RF) traits were found to be comparable to those of InP-based lattice-matched high-electron-mobility transistors (LM-HEMTs). However, the Pulsed I–V measurement results confirmed the presence of the fast transient charging effect, leading to a more substantial degradation in drain current observed in MHEMT. In addition, through the low-frequency noise characteristics, it was confirmed that the dominant trapping location was located in the bulk site. The slope of the 1/f noise measurement indicated that the primary trapping site was in proximity to the bulk traps. The carrier-number-fluctuation (CNF) model was employed to extract the bulk trap density (Nt). For the LM-HEMTs, the value was at 3.27 × 1016 eV−1·cm−3, while for the MHEMT, it was 3.56 × 1017 eV−1·cm−3.
From Bioresources to Thermal Insulation Materials: Synthesis and Properties of Two-Component Open-Cell Spray Polyurethane Foams Based on Bio-Polyols from Used Cooking Oil
Authors: Polaczek Krzysztof , Kurańska Maria , Malewska Elżbieta , Czerwicka-Pach Małgorzata , Prociak Aleksander
Published: September 2023

Open-cell spray polyurethane foams are widely used as highly efficient thermal insulation materials with vapor permeability and soundproofing properties. Unfortunately, for the production of commercial foams, mainly non-renewable petrochemical raw materials are used. The aim of this study was to determine the possibility of completely replacing petrochemical polyols (the main raw material used in the synthesis of polyurethanes, alongside isocyanates) with bio-polyols obtained from used cooking oils, classified as waste materials. The research consisted of three stages: the synthesis of bio-polyols, the development of polyurethane foam systems under laboratory conditions, and the testing of developed polyurethane spray systems under industrial conditions. The synthesis of the bio-polyols was carried out by using two different methods: a one-step transesterification process using triethanolamine and a two-step process of epoxidation and opening oxirane rings with diethylene glycol. The obtained bio-polyols were analyzed using gel chromatography and nuclear magnetic resonance spectroscopy. The developed polyurethane foam formulations included two types of fire retardants: halogenated tris(1-chloro-2-propyl) phosphate (TCPP) and halogen-free triethyl phosphate (TEP). In the formulations of polyurethane systems, reactive amine catalysts were employed, which become incorporated into the polymer matrix during foaming, significantly reducing their emission after application. The foams were manufactured on both a laboratory and industrial scale using high-pressure spray machines under conditions recommended by commercial system manufacturers: spray pressure 80–100 bar, component temperature 45–52 °C, and component volumetric ratio 1:1. The open-cell foams had apparent densities 14–21.5 kg/m3, thermal conductivity coefficients 35–38 mW/m∙K, closed-cell contents <5%, water vapor diffusion resistance factors (μ) <6, and limiting oxygen indexes 21.3–21.5%. The properties of the obtained foams were comparable to commercial materials. The developed polyurethane spray systems can be used as thermal insulation materials for insulating interior walls, attics, and ceilings.
A Molecular Dynamics Study on the Dislocation-Precipitate Interaction in a Nickel Based Superalloy during the Tensile Deformation
Authors: Wan Chang-Feng , Sun Li-Gang , Qin Hai-Long , Bi Zhong-Nan , Li Dong-Feng
Published: September 2023

In the present paper, the dislocation-precipitate interaction in the Inconel 718 superalloy is studied by means of molecular dynamics simulation. The atomistic model composed of the ellipsoidal Ni3Nb precipitate (γ″ phase) and the Ni matrix is constructed, and tensile tests on the composite Ni3Nb@Ni system along different loading directions are simulated. The dislocation propagation behaviors in the precipitate interior and at the surface of the precipitate are characterized. The results indicate that the dislocation shearing and bypassing simultaneously occur during plastic deformation. The contact position of the dislocation on the surface of the precipitate could affect the penetration depth of the dislocation. The maximum obstacle size, allowing for the dislocation shearing on the slip planes, is found to be close to 20 nm. The investigation of anisotropic plastic deformation behavior shows that the composite system under the loading direction along the major axis of the precipitate experiences stronger shear strain localizations than that with the loading direction along the minor axis of the precipitate. The precipitate size effect is quantified, indicating that the larger the precipitate, the lower the elastic limit of the flow stress of the composite system. The dislocation accumulations in the precipitate are also examined with the dislocation densities given on specific slip systems. These findings provide atomistic insights into the mechanical behavior of nickel-based superalloys with nano-precipitates.
Effects of TiC, Si, and Al on Combustion Synthesis of Ti3SiC2/TiC/Ti5Si3 Composites
Authors: Yeh Chun-Liang , Lai Kuan-Ling
Published: September 2023

The fabrication of Ti3SiC2 from TiC-containing reactant compacts was investigated by combustion synthesis in the mode of self-propagating high-temperature synthesis (SHS). The initial sample composition was formulated based on (3 − x)Ti + ySi + (2 − x)C + xTiC + zAl, with stoichiometric parameters of x from 0 to 0.7, y = 1.0 and 1.2, and z = 0 and 0.1. For all samples studied, combustion was sufficiently exothermic to sustain the reaction in the SHS manner. Due to the dilution effect of TiC, combustion wave velocity and reaction temperature substantially decreased with TiC content. When compared with the TiC-free sample, the TiC-containing sample facilitated the formation of Ti3SiC2 and the TiC content of x = 0.5 produced the highest yield. Excess Si (y = 1.2) to compensate for the evaporation loss of Si during combustion and the addition of Al (z = 0.1) to promote the phase conversion were effective in improving the evolution of Ti3SiC2. All final products were composed of Ti3SiC2, TiC, and Ti5Si3. For the TiC-containing samples of x = 0.5, the weight fraction of Ti3SiC2 increased from 67 wt.% in the sample without extra Si and Al to 72 wt.% in the Si-rich sample of y = 1.2 and further up to 85 wt.% in the Si-rich/Al-added sample of y = 1.2 and z = 0.1. As-synthesized Ti3SiC2 grains were in a thin plate-like shape with a thickness of 0.5–1.0 μm and length of about 10 μm. Ti3SiC2 platelets were closely stacked into a layered structure.
Metal-Organic Frameworks: Versatile Platforms for Biomedical Innovations
Authors: Păun Cătălin , Motelică Ludmila , Ficai Denisa , Ficai Anton , Andronescu Ecaterina
Published: September 2023

This review article explores the multiple applications and potential of metal-organic frameworks (MOFs) in the biomedical field. With their highly versatile and tunable properties, MOFs present many possibilities, including drug delivery, biomolecule recognition, biosensors, and immunotherapy. Their crystal structure allows precise tuning, with the ligand typology and metal geometry playing critical roles. MOFs’ ability to encapsulate drugs and exhibit pH-triggered release makes them ideal candidates for precision medicine, including cancer treatment. They are also potential gene carriers for genetic disorders and have been used in biosensors and as contrast agents for magnetic resonance imaging. Despite the complexities encountered in modulating properties and interactions with biological systems, further research on MOFs is imperative. The primary focus of this review is to provide a comprehensive examination of MOFs in these applications, highlighting the current achievements and complexities encountered. Such efforts will uncover their untapped potential in creating innovative tools for biomedical applications, emphasizing the need to invest in the continued exploration of this promising field.
Controlled Dispersion and Transmission-Absorption of Optical Energy through Scaled Metallic Plate Structures
Authors: Oubeniz Hammou , Belkacem Abdelhaq , Mangach Hicham , Kadic Muamer , Bouzid Abdenbi , Achaoui Younes
Published: September 2023

The dispersive feature of metals at higher frequencies has opened up a plethora of applications in plasmonics. Besides, Extraordinary Optical Transmission (EOT) reported by Ebbesen et al. in the late 90’s has sparked particular interest among the scientific community through the unprecedented and singular way to steer and enhance optical energies. The purpose of the present paper is to shed light on the effect of the scaling parameter over the whole structure, to cover the range from the near-infrared to the visible, on the transmission and the absorption properties. We further bring specific attention to the dispersive properties, easily extractable from the resonance frequency of the drilled tiny slits within the structure. A perfect matching between the analytical Rigorous Coupled Wave Analysis (RCWA), and the numerical Finite Elements Method (FEM) to describe the underlying mechanisms is obtained.
Characterization and Design of Three-Phase Particulate Composites: Microstructure-Free Finite Element Modeling vs. Analytical Micromechanics Models
Authors: Oli Sebak , Luo Yunhua
Published: September 2023

Three-phase particulate composites offer greater design flexibility in the selection of phase materials and have more design variables than their two-phase counterparts, thus providing larger space for tailoring effective properties to meet intricate engineering requirements. Predicting effective elastic properties is essential for composite design. However, experimental methods are both expensive and time intensive, whereas the scope of analytical micromechanics models is limited by their inherent assumptions. The newly developed microstructure-free finite element modeling (MF-FEM) approach has been demonstrated to be accurate and reliable for two-phase particulate composites. In this study, we investigate whether the MF-FEM approach can be applied to three-phase particulate composites and, if applicable, under which conditions. The study commences with a convergence analysis to establish the threshold ratio between the element size and the RVE (representative volume element) dimension. We then validate the MF-FEM approach using experimental data on three-phase composites from the existing literature. Subsequently, the MF-FEM method serves as a benchmark to assess the accuracy of both traditional and novel analytical micromechanics models, in predicting the effective elasticity of two distinct types of three-phase particulate composites, characterized by their small and large phase contrasts, respectively. We found that the threshold element-to-RVE ratio (1/150) for three-phase composites is considerably smaller than the ratio (1/50) for two-phase composites. The validation underscores that MF-FEM predictions align closely with experimental data. The analytical micromechanics models demonstrate varying degrees of accuracy depending on the phase volume fractions and the contrast in phase properties. The study indicates that the analytical micromechanics models may not be dependable for predicting effective properties of three-phase particulate composites, particularly those with a large contrast in phase properties. Even though more time-intensive, the MF-FEM proves to be a more reliable approach than the analytical models.
Study of Atomic Layer Deposition Nano-Oxide Films on Corrosion Protection of Al-SiC Composites
Authors: Chen Hou-Jen , Chen Ying-Chu , Lin Pi-Chen , Lin Kaifan , Lin Jonathan C. , Chen Miin-Jang , Lin Hsin-Chih
Published: September 2023

In recent years, aluminum matrix composites (AMCs) have attracted attention due to their promising properties. However, the presence of ceramic particles in the aluminum matrix renders AMCs a high corrosion rate and makes it challenging to use traditional corrosion protection methods. In this study, atomic layer deposition (ALD) techniques were used to deposit HfO2, ZrO2, TiO2, and Al2O3 thin films on AMC reinforced with 20 vol.% SiC particles. Our results indicate that the presence of micro-cracks between the Al matrix and SiC particles leads to severe micro-crack-induced corrosion in Al-SiC composites. The ALD-deposited films effectively enhance the corrosion resistance of these composites by mitigating this micro-crack-induced corrosion. Among these four atomic-layer deposited films, the HfO2 film exhibits the most effective reduction in the corrosion current density of Al-SiC composites in a 1.5 wt% NaCl solution from 1.27 × 10−6 A/cm2 to 5.89 × 10−11 A/cm2. The electrochemical impedance spectroscopy (EIS) investigation shows that HfO2 deposited on Al-SiC composites has the largest Rp value of 2.0 × 1016. The HfO2 film on Al-SiC composites also exhibits effective inhibition of pitting corrosion, remaining at grade 10 even after 96 h of a salt spray test.