bluuebunny/crossref_metadata_2025 huggingface dataset:
Advancing Food Packaging: Exploring Cyto-Toxicity of Shape Memory Polyurethanes
Authors: Veloso-Fernández Antonio , Laza José Manuel , Ruiz-Rubio Leire , Martín Ane , Benito-Vicente Asier , Martín Cesar , Vilas-Vilela José Luis
Published: September 2024

Cytotoxicity is a critical parameter for materials intended for biological applications, such as food packaging. Shape-memory polyurethanes (SMPUs) have garnered significant interest due to their versatile properties and adaptability in synthesis. However, their suitability for biological applications is limited by the use of aromatic isocyanates, such as methylene diphenyl 4,4′-diisocyanate (MDI) and toluene diisocyanate (TDI), which are commonly used in SMPU synthesis but can generate carcinogenic compounds upon degradation. In this study, thermo-responsive shape-memory polyurethanes (SMPUs) were synthesized using poly(tetramethylene ether) glycol (PTMG) and castor oil (CO) as a chain extender with four different isocyanates—aromatic (MDI and TDI), aliphatic (hexamethylene diisocyanate [HDI] and isophorone diisocyanate [IPDI])—to evaluate their impact on polyurethane cytotoxicity. Cytotoxicity assays were conducted on the synthesized SMPU samples before and after exposure to light-induced degradation. The results showed that prior to degradation, all samples exhibited cell proliferation rates above 90%. However, after degradation, the SMPUs containing aromatic isocyanates demonstrated a drastic reduction in cell proliferation to values below 10%, whereas the samples with aliphatic isocyanates maintained cell proliferation above 70%. Subsequently, the influence of polyol chain length was assessed using PTMG, with molecular weights of 1000, 650, and 250 g·mol−1. The results indicated that the SMPUs with longer chain lengths exhibited higher cell proliferation rates both before and after degradation. The thermal and mechanical properties of the SMPUs were further characterized using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and thermomechanical analysis (TMA), providing comprehensive insights into the behavior of these materials.
A Study of the Influence of Thermoactivated Natural Zeolite on the Hydration of White Cement Mortars
Authors: Stoyanov Ventseslav , Petkova Vilma , Mihaylova Katerina , Shopska Maya
Published: September 2024

One trend in the development of building materials is the partial or complete replacement of traditional materials that have a high carbon footprint with eco-friendly ecological raw materials and ingredients. In the present work, the influence of replacing cement with 10 wt% thermally activated natural zeolite on the structural and physical-mechanical characteristics of cured mortars based on white Portland cement and river sand was investigated. The phase compositions were determined by wavelength dispersive X-ray fluorescence (WD-XRF) analysis, X-ray powder diffraction (PXRD), diffuse reflectance infrared Fourier transformed spectroscopy (DRIFTS), and scanning electron microscopy (SEM), as well as thermogravimetric analysis simultaneously with differential scanning calorimetry (TG/DTG-DSC). The results show that the incorporation of zeolite increases the amount of pores accessible with mercury intrusion porosimetry by about 40%, but the measured strengths are also higher by over 13%. When these samples were aged in an aqueous environment from day 28 to day 120, the amount of pores decreased by about 10% and the compressive strength increased by nearly 15%, respectively. The microstructural analysis carried out proves that these results are due to hydration with a low content of crystal water and the realization of pozzolanic reactions that last over time. Replacing some of the white cement with thermally activated natural zeolite results in the formation of a greater variety of crystals, including new crystalline CSH and CSAH phases that allow better intergrowth and interlocking. The results of the investigations allow us to present a plausible reaction mechanism of pozzolanic reactions and of the formation of new crystal hydrate phases. This gives grounds to claim that the replacement of part of the cement with zeolite improves the corrosion resistance of the investigated building solutions against aggressive weathering.
Study of Flow and Zinc Dross Removal in Hot-Dip Galvanizing with Combined Traveling Magnetic Field
Authors: Luo Xianwen , Lu Haibiao , Zhong Yunbo , Ren Weili , Lei Zuosheng
Published: September 2024

The removal of zinc dross, which continuously generates and partially floats on a molten zinc surface, has been a persistent challenge during hot-dip galvanizing. Herein, a three-dimensional mathematical model coupled with the electromagnetic field, flow field and air-knife jet flow was established to investigate the flow and zinc dross removal in a zinc pot. Two types of traveling magnetic field combined modes (Mode 1 and Mode 2) were compared. The surface dross removal efficiency was introduced to evaluate the ability of the zinc flow field to compel the movement of zinc dross. The research findings indicate that, in comparison to the influence of strip steel line speed, both the electromagnetic field and air-knife jet have a more pronounced effect on altering the flow characteristics of a molten zinc at surface. The dross removal efficiency for Mode 1 is much far superior to that of Mode 2. With an increase in the driving current, the dross removal efficiency increases while the excessive driving current cannot promote the dross removal efficiency significantly.
Laboratory Investigation of the Strength Degradation against Ultraviolet Radiation of Geonets for Slope Protection
Authors: Zhang Rui , Wang Huan , Liu Zhengnan , Wang Xiang , Yang Heping , Zhang Yani
Published: September 2024

Sufficient light and high UV intensity pose significant challenges to the long-term performance of polymeric geonet materials for slope-protection structures. This study investigates strength degradation under the effect of UV radiation; five different types of geonets were selected, which can be categorized as polyamide (PA), polypropylene (PP), and polyethylene (PE) materials. A comprehensive experimental investigation was performed, including tension strength, peer strength, artificially accelerated aging, and SEM tests, to further establish a service life prediction method used for slope-protection design. The results showed that the tension strength, percentage of breaking elongation, and peer strength all depict a descending trend with aging-elapsed time, especially in the early 600 h. The decreasing tendency of these mechanical properties’ magnitude differed in the diversity of direction and material type. Significant changes have been generated on the geonet surface after aging; materials with smooth surfaces exhibit a strong ability against strength degradation. Fitting results affirmed the predictive technique as a useful engineering tool for tension strength assessments, offering guidelines for using and designing of geonets for slope-protection structures.
Theoretical Study of the Adsorption and Sensing Properties of Cr-Doped SnP3 Monolayer for Dissolved Characteristic Gases in Oil
Authors: Wang Chengjiang , Liu Xiangjia , Xie Feiyang , Wang Xuze , Zhang Pengdi
Published: September 2024

Dissolved gas analysis (DGA) is a vital method for the online detection of transformer operation state. The adsorption performance of a SnP3 monolayer modified by transition metal Cr regarding six characteristic gases (CO, C2H4, C2H2, CH4, H2, C2H6) dissolved in oil was studied. The study reveals the relevant adsorption and gas-sensing response mechanisms through calculations of the adsorption energy, density of states, differential charge density, energy gap, and recovery time. The results display a considerable increase in the adsorption effect of the Cr-SnP3 monolayer on six gases. The CO, C2H2, and C2H4 gases lead to chemical adsorption, and the CH4, H2, and C2H6 gases lead to physical adsorption. Combined with the recovery time, the Cr-SnP3 monolayer has a strong adsorption effect on CO and C2H2 gases at normal temperatures and even high temperatures, and the adsorption is stable. C2H4 gas can be rapidly desorbed from the Cr-SnP3 monolayer at 398 K. Therefore, the Cr-SnP3 monolayer can be expected to serve as a CO and C2H2 gas adsorbent and a resistive gas sensor for C2H4 gas. This research offers a theoretical foundation for the development of the Cr-SnP3 monolayer in gas-sensitive materials.
Effects of Curing Regimes on Calcium Oxide–Belite–Calcium Sulfoaluminate-Based Aerated Concrete
Authors: Xia Yanqing , Lu Xirui , Li Jun , Yang Li , Wang Ning , Chen Xuemei , Zhong Wen
Published: September 2024

This study delves into the effects of carbonation curing and autoclave–carbonation curing on the properties of calcium oxide–belite–calcium sulfoaluminate (CBSAC) cementitious material aerated concrete. The objective is to produce aerated concrete that adheres to the strength index in the Chinese standard GB/T 11968 while simultaneously mitigating CO2 emissions from cement factories. Results show that the compressive strength of CBSAC aerated concrete with different curing regimes (autoclave curing, carbonation curing, and autoclave–carbonation curing) can reach 4.3, 0.8, and 4.1 MPa, respectively. In autoclave–carbonation curing, delaying CO2 injection allows for better CO2 diffusion and reaction within the pores, increases the carbonation degree from 19.1% to 55.1%, and the bulk density from 603.7 kg/m3 to 640.2 kg/m3. Additionally, microstructural analysis reveals that delaying the injection of CO2 minimally disrupts internal hydrothermal synthesis, along with the formation of calcium carbonate clusters and needle-like silica gels, leading to a higher pore wall density. The industrial implementation of autoclavecarbonation curing results in CBSAC aerated concrete with a CO2 sequestration capacity ranging from 40 to 60 kg/m3 and a compressive strength spanning from 3.6 to 4.2 MPa. This innovative approach effectively mitigates the carbon emission pressures faced by CBSAC manufacturers.
Optimal Design of a Bilateral Stand-Alone Robotic Motion-Assisted Finger Exoskeleton for Home Rehabilitation
Authors: Valayil Tony Punnoose , Tanev Tanio K.
Published: September 2024

This paper presents a novel exoskeleton robot that can be used at home to rehabilitate the index fingers of stroke-affected patients. This exoskeleton is designed as a one-degree-of-freedom four-bar mechanism able to guide the human index finger to perform a finger curl exercise motion. The proposed device is the only lateral, stand-alone mechanism built to date that can carry the weight of the human hand, thus making the user free from wearing it. The design starts by tracing the trajectory of the index finger using ‘Angulus’ software. ‘SALAR Mechanism Synthesizer’ software is used for dimensional synthesis of the four-bar mechanism. Using additive manufacturing technology, a prototype of the proposed device is developed. Static force analysis is performed to select the most appropriate actuator for producing the required torque to manipulate the fingers effectively. The kinematics of the index finger while performing a finger curl exercise is obtained. The proposed linkage mechanism can drive the index fingers of both hands. Simulation and experimental results proved the feasibility and effectiveness of the proposed design to be used for index finger rehabilitation for a wide range of users and applications by making simple minor alterations in the design. Also, a scheme for when the device can be used for rehabilitating the middle finger together with the index finger when performing flexion and extension motions is discussed.
Modelling the Elliptical Instability of Magnetic Skyrmions
Authors: Barton-Singer Bruno
Published: September 2024

Two recently developed methods of modelling chiral magnetic soliton elliptical instability are applied in two novel scenarios: the tilted ferromagnetic phase of chiral magnets dominated by easy-plane anisotropy and the general case of the chiral magnet with tilted applied field and arbitrary uniaxial anisotropy. In the former case, the analytical predictions are found to exactly match previous numerical results. In the latter case, the instability of isolated chiral skyrmions has not yet been studied, although interestingly, the predictions correspond to previous numerical investigation into the phase diagram.
Not in My Face: Challenges and Ethical Considerations in Automatic Face Emotion Recognition Technology
Authors: Mattioli Martina , Cabitza Federico
Published: September 2024

Automatic Face Emotion Recognition (FER) technologies have become widespread in various applications, including surveillance, human–computer interaction, and health care. However, these systems are built on the basis of controversial psychological models that claim facial expressions are universally linked to specific emotions—a concept often referred to as the “universality hypothesis”. Recent research highlights significant variability in how emotions are expressed and perceived across different cultures and contexts. This paper identifies a gap in evaluating the reliability and ethical implications of these systems, given their potential biases and privacy concerns. Here, we report a comprehensive review of the current debates surrounding FER, with a focus on cultural and social biases, the ethical implications of their application, and their technical reliability. Moreover, we propose a classification that organizes these perspectives into a three-part taxonomy. Key findings show that FER systems are built with limited datasets with potential annotation biases, in addition to lacking cultural context and exhibiting significant unreliability, with misclassification rates influenced by race and background. In some cases, the systems’ errors lead to significant ethical concerns, particularly in sensitive settings such as law enforcement and surveillance. This study calls for more rigorous evaluation frameworks and regulatory oversight, ensuring that the deployment of FER systems does not infringe on individual rights or perpetuate biases.
Explicit Modeling of Multi-Product Customer Orders in a Multi-Period Production Planning Model
Authors: Palma Cristian D. , Vergara Francisco P. , Muñoz-Herrera Sebastián
Published: September 2024

In many industries, companies receive customer orders that include multiple products. To simplify the use of optimization models for planning purposes, these orders are broken down, and the quantities of each product are grouped with the same products from other orders to be completed in the same period. Consequently, traditional production planning models enforce minimum demand constraints by product and period rather than by individual orders. An important drawback of this aggregation procedure is that it requires a fixed order fulfillment period, potentially missing opportunities for more efficient resource use through early completion. This paper introduces a novel mathematical formulation that preserves the integrity of customer orders, allowing for early fulfillment when possible. We compare a traditional linear programming model with a new mixed-integer programming approach using a sawmill case study. Although more complex than the traditional model, the proposed formulation reduces costs by approximately 6% by enabling early order completion and offers greater flexibility and control over the production process. This approach leads to better resource utilization and more precise order management, presenting a valuable alternative to conventional production planning models.
Applications of Extended Kummer’s Summation Theorem
Authors: Wang Xiaoxia , Rathie Arjun K. , Lim Eunyoung , Kim Hwajoon
Published: September 2024

In the theory of hypergeometric series and generalized hypergeometric series, classical summation theorems, such as the two of Gauss and those of Kummer and Bailey for the series F12; those of Watson, Dixon, Whipple, and Saalschutz for the series F23; and others, play a key role. Applications of these classical summation theorems are well known. Berndt pointed out that a large number of interesting summations (including Ramanujan’s summations and the Gregory–Leibniz pi summation) can be obtained very quickly by employing the above-mentioned classical summation theorems. Also, several interesting results involving products of generalized hypergeometric series have been obtained by Bailey by employing the above-mentioned classical summation theorems. Recently, the above-mentioned classical summation theorems have been generalized and extended. In our present investigations, our aim is to demonstrate the applications of the extended Kummer’s summation theorem in establishing (i) extensions of Gauss’s second summation theorem and Bailey’s summation theorem; (ii) extensions of several summations (including Ramanujan’s summations); (iii) extensions of several results involving products of generalized hypergeometric series; and (iv) an extension of classical Dixon’s summation theorem. As special cases, we recover several known summations (including several Ramanujan summations and the Gregory–Leibniz pi summation) and various results involving products of generalized hypergeometric series due to Bailey.
RideChain: A Blockchain-Based Decentralized Public Transportation Smart Wallet
Authors: Alhogail Areej , Alshahrani Mona , Alsheddi Alanoud , Almadi Danah , Alfaris Noura
Published: September 2024

The transportation industry has been recognized as one of the industries that can benefit from investment in blockchain-based systems and services that enable distributed data management and improve the effectiveness and efficiency of the transportation sector. However, the literature needs a guiding framework for integrating blockchain in issuing and preserving public transportation transactions in a technical environment that is secure, efficient, and transparent. This study proposes a blockchain-based transportation wallet (BTW) framework that facilitates the main digital transactions across diverse public transportation services. BTW embodies leveraging blockchain technology, which provides a decentralized and immutable ledger that records and verifies transactions, ensuring trust and reducing the risk of fraud. The framework has been validated by developing a blockchain-based public transportation smart wallet named “RideChain”. This serves as a single decentralized point for making public transportation transactions and payments, as well as identity authorizations and management. RideChain enhances passengers’ and service providers’ experience through a secure and authentic platform for offering several reliable public transportation transactions efficiently. In this study, we implemented a smart contract to establish a protocol between passengers and journey services. The testing methodologies used in this study comprise unit testing, integration testing, performance testing, and user acceptance testing. The findings suggest that BTW has been successfully verified to demonstrate its capability for secure transactions, authenticity of monetary transactions, automated smart contracts, decentralized identity authentication, and effortless payments.
Approximate Analytic Frequency of Strong Nonlinear Oscillator
Authors: Cveticanin Livija , Zukovic Miodrag , Cveticanin Dragan
Published: September 2024

In this paper, a new analytic expression for the frequency of vibration of a strong nonlinear polynomial-type oscillator is introduced. The method for frequency calculation is based on the transformation of the nonlinear oscillators into linear ones using the equality of their amplitudes and periods of vibration. The frequency of the linear oscillator is assumed to be the sum of frequencies corresponding to each nonlinearity in the original oscillator separately, i.e., the sum of frequencies of truly nonlinear oscillators. The obtained frequency is a complex function of amplitude, coefficient and order of nonlinearity. For simplification, the frequencies of the truly nonlinear oscillators are modified as power order functions of the exact frequency of the cubic oscillator which is linearly dependent on the amplitude of vibration. In this paper, the approximate frequency expression is developed for the harmonic any-order nonlinear oscillator and oscillators with the sum of polynomial nonlinearities. The accuracy of the obtained frequencies is tested on the examples of non-integer order nonlinear oscillators and also on a quadratic-cubic oscillator. The difference between the analytical and exact, numerically obtained results is negligible. The suggested approximate frequency expression has a simple algebraic form and is suitable for application by engineers and technicians.
The Asymptotic Behavior and Blow-Up Rate of a Solution with a Lower Bound on the Highest Existence Duration for Semi-Linear Pseudo-Parabolic Equations
Authors: Liu Nian
Published: September 2024

This note addresses the initial-boundary value problem for a class of semi-linear pseudo-parabolic equations defined on a smooth bounded domain, with an emphasis on determining the asymptotic behavior and blow-up rate of the solution. Our analysis considers both low-initial energy and critical-initial energy cases, with a specific focus on establishing a lower bound on the maximal existence time of the solutions to this problem.
Cutting-Edge Amalgamation of Web 3.0 and Hybrid Chaotic Blockchain Authentication for Healthcare 4.0
Authors: Kumar Ajay , Abhishek Kumar , Khan Surbhi Bhatia , Alzahrani Saeed , Alojail Mohammed
Published: September 2024

Healthcare 4.0 is considered the most promising technology for gathering data from humans and strongly couples with a communication system for precise clinical and diagnosis performance. Though sensor-driven devices have largely made our everyday lives easier, these technologies have been suffering from various security challenges. Because of data breaches and privacy issues, this heightens the demand for a comprehensive healthcare solution. Since most healthcare data are sensitive and valuable and transferred mostly via the Internet, the safety and confidentiality of patient data remain an important concern. To face the security challenges in Healthcare 4.0, Web 3.0 and blockchain technology have been increasingly deployed to resolve the security breaches due to their immutability and decentralized properties. In this research article, a Web 3.0 ensemble hybrid chaotic blockchain framework is proposed for effective and secure authentication in the Healthcare 4.0 industry. The proposed framework uses the Infura Web API, Web 3.0, hybrid chaotic keys, Ganache interfaces, and MongoDB. To allow for more secure authentication, an ensemble of scroll and Henon maps is deployed to formulate the high dynamic hashes during the formation of genesis blocks, and all of the data are backed in the proposed model. The complete framework was tested in Ethereum blockchain using Web 3.0, in which Python 3.19 is used as the major programming tool for developing the different interfaces. Formal analysis is carried out with Burrows–Abadi–Needham Logic (BAN) to assess the cybersecurity reliability of the suggested framework, and NIST standard tests are used for a thorough review. Furthermore, the robustness of the proposed blockchain is also measured and compared with the other secured blockchain frameworks. Experimental results demonstrate that the proposed model exhibited more defensive characteristics against multiple attacks and outperformed the other models in terms of complexity and robustness. Finally, the paper gives a panoramic view of integrating Web 3.0 with the blockchain and the inevitable directions of a secured authentication framework for Healthcare 4.0.
New Fusarochromanone Derivatives from the Marine Fungus Fusarium equiseti UBOCC-A-117302
Authors: Pham Giang Nam , Josselin Béatrice , Cousseau Arnaud , Baratte Blandine , Dayras Marie , Le Meur Christophe , Debaets Stella , Weill Amélie , Robert Thomas , Burgaud Gaëtan , Probert Ian , Abdoul-Latif Fatouma Mohamed , Boyer Laurent , Bach Stéphane , Mehiri Mohamed
Published: September 2024

Two new fusarochromanone derivatives, deacetylfusarochromene (1) and deacetamidofusarochrom-2′,3-diene (2), along with the previously reported metabolites fusarochromanone TDP-2 (3), fusarochromene (4), 2,2-dimethyl-5-amino-6-(2′E-ene-4′-hydroxylbutyryl)-4-chromone (5), fusarochromanone (6), (−)-chrysogine (7), and equisetin (8), were isolated from the marine fungus Fusarium equiseti UBOCC-A-117302. The structures of the compounds were determined by extensive spectrometric (HRMS) and spectroscopic (1D and 2D NMR) analyses, as well as specific rotation. Among them, 2 and 5 showed inhibition of three protein kinases with IC50 values ranging from 1.42 to 25.48 μM. Cytotoxicity and antimicrobial activity of all isolated compounds were also evaluated. Six fusarochromanone derivatives (1–6) exhibited diverse activities against three cell lines, RPE-1, HCT-116, and U2OS (IC50 values ranging from 0.058 to 84.380 μM). Equisetin (8) showed bactericidal activities against Bacillus cereus and Listeria monocytogenes (MBC values of 7.8 and 31.25 µM, respectively), and bacteriostatic activity against Enterococcus faecalis (MIC value of 31.25 µM). Compounds 2 and 4 showed bacteriostatic activities against Listeria monocytogenes (MIC of 125 µM).
The Role of Vericiguat in Early Phases of Anterior Myocardial Infarction: A Potential Game-Changer?
Authors: Cacciapuoti Federico , Mauro Ciro , Capone Valentina , Chianese Salvatore , Tarquinio Luca Gaetano , Gottilla Rossella , Marsico Fabio , Crispo Salvatore , Cacciapuoti Fulvio
Published: September 2024

Anterior myocardial infarction is a critical condition with significant implications for cardiac function and patient prognosis. Despite advancements in reperfusion therapies, optimizing recovery during the early phases of myocardial infarction remains challenging. Anterior myocardial infarction can lead to substantial long-term effects on a patient’s health due to extensive damage to the heart muscle, particularly the left ventricle, impacting both quality of life and overall prognosis. Vericiguat, a soluble guanylate cyclase stimulator, has shown promise in heart failure, but its role in early anterior myocardial infarction has not yet been fully explored. By enhancing soluble guanylate cyclase activity, vericiguat may increase cyclic guanosine monophosphate production, leading to vasodilation, inhibition of platelet aggregation, and potential cardioprotective effects. Currently, treatment options for anterior myocardial infarction primarily focus on reperfusion strategies and managing complications. However, there is a critical need for adjunctive therapies that specifically target the pathophysiological changes occurring in the early phases of myocardial infarction. Vericiguat’s mechanism of action offers a novel approach to improving vascular function and myocardial health, potentially contributing to innovative treatment strategies that could transform the care and prognosis of patients with anterior myocardial infarction.
Determination of the Microbial Shift in the Gingival Sulcus of Women during Each Trimester of Pregnancy: A Cross-Sectional Study
Authors: Alsakr Abdulaziz , Tawfig Ahmed , Almutairi Faisal Talal , Ababtain Ibrahim Mansour , Saeed Alasmari Hind Mohammed , Alnufaiy Banna , Gufran Khalid
Published: September 2024

Background and Objectives: This study aims to identify types of bacterial species in women visiting obstetrics/gynecology centers in Riyadh City, Saudi Arabia, during different pregnancy trimesters. Materials and Methods: This cross-sectional study was conducted among pregnant and nonpregnant women seeking care at Alyamamah Hospital, obstetrics/gynecology center, Riyadh, Saudi Arabia. A total of 110 [pregnant = 90 and nonpregnant = 20] individuals were recruited based on inclusion/exclusion criteria. Personal data, plaque index (PI), and gingival index (GI) were recorded. Bacterial samples were collected using sterile absorbent paper points from the gingival sulcus of pregnant females during the first, second, and third trimesters and compared to a control group of nonpregnant females. Thioglycolate broth containing the absorbent paper points was incubated at 37 °C for 24–48 h. After growth, the microorganisms were subjected to a Gram stain. The VITEK 2 system and conventional methods were used to identify various types of bacterial species from the gingival sulcus of pregnant and nonpregnant women. Chi-square tests and nonparametric tests were applied to the data. Results: The bacterial characterization indicated that Actinomyces naeslundii (AN) was the most predominant bacteria found in the study participants, followed by Lactobacillus fermentum (LF) (23.6%), Veillonella (VL) (10%), and unidentified organisms (9.1%). When the presence of subgingival bacterial species was compared between pregnant and nonpregnant women, a statistically significant difference was observed (p < 0.001). LF was the predominant bacteria in 9 nonpregnant women (45%) and 8 pregnant women in the first pregnancy trimester (44.4%). However, during the second (17 women: 48.6%) and third pregnancy (17 women: 45.9%) trimesters, AN becomes the predominant bacteria. A statistically significant difference was observed when the prevalence of various bacterial species was compared across the three pregnancy trimesters (p = 0.010). The plaque and gingival scores of pregnant and nonpregnant women showed no significant difference. Conclusions: In different trimesters of pregnancy, pregnant women’s gingival crevices showed significant microbial changes without affecting gingival inflammation.
Effect of Hot Extrusion on Microstructure, Texture, and Mechanical Properties of Mg-Zn-Mn-0.5Ca Alloy
Authors: Li Ming , Yao Mengling , Yang Yuhang , Zhao Gaozhan , Wang Yongxiang , Shu Dayu , Chai Shuxin , Zhang Feiyue , Xia Xiangsheng , Wan Yuanyuan , Wang Hongxia
Published: September 2024

This paper investigates the microstructure, texture, and mechanical properties of the Mg-4Zn-1Mn-0.5Ca alloy subjected to hot extrusion under varying conditions of temperature (260 °C, 300 °C, 340 °C) and extrusion speed (0.01 mm/s, 0.1 mm/s, 1 mm/s). The primary objective is to determine the optimal extrusion parameters within the selected experimental range for achieving superior mechanical properties. The results indicate that, when extruded at a constant speed of 0.1 mm/s, the alloy exhibits optimal performance at 340 °C, with a yield strength of 202 MPa, ultimate tensile strength (UTS) of 306 MPa, and elongation at fracture of 18.9%. A decrease in extrusion temperature leads to an increase in yield strength but a reduction in ductility. Specifically, the UTS reaches its peak at 342 MPa at 300 °C, while it drops slightly to 329 MPa at 260 °C. The final results show that the comprehensive mechanical properties of the Mg-4Zn-1Mn-0.5Ca alloy obtained by hot extrusion treatment with an extrusion temperature of 300 °C and extrusion speed of 0.1 mm/s are the best and can effectively improve the mechanical properties of the alloy and provide a good choice for the preparation of other biodegradable magnesium alloy products.
Effect of Er on the Hot Deformation Behavior of the Crossover Al3Zn3Mg3Cu0.2Zr Alloy
Authors: Glavatskikh Maria V. , Gorlov Leonid E. , Loginova Irina S. , Barkov Ruslan Yu. , Khomutov Maxim G. , Churyumov Alexander Yu. , Pozdniakov Andrey V.
Published: September 2024

The effect of an erbium alloying on the hot deformation behavior of the crossover Al3Zn3Mg3Cu0.2Zr alloy was investigated in detail. First of all, Er increases the solidus temperature of the alloy. This allows hot deformation at a higher temperature. The precipitates resulting from the Er alloying of the Al3Zn3Mg3Cu0.2Zr alloy were analyzed using transmission electron microscopy. Erbium addition to the alloy produces the formation of more stable and fine L12-(Al3(Zr, Er)) precipitates with a size of 20–60 nm. True stress tends to increase with a decline in the temperature and an increase in the deformation rate. The addition of Er leads to decreases in true stress at the strain rates of 0.01–1 s−1 due to particle-stimulated nucleation softening mechanisms. The effective activation energy of the alloy with the Er addition has a lower value, enabling an easier hot deformation process in the alloy with an elevated volume fraction of the intermetallic particles. The addition of Er increases the strain rate sensitivity, which makes the failure during deformation less probable. The investigated alloys have a significant difference in the dependence of the activation volume on the temperature. The flow instability criterion allows better deformability of Er-doped alloys and enables the alloys to be formed more easily. The evenly distributed particles prevent the formation of shear bands with elevated storage energy and decrease the probability of crack initiation during the initial stages of hot deformation when only one softening mechanism (dynamic recovery) is working. The microstructure analysis proves that dynamic recovery is the main softening mechanism.
Critical Evaluation and Thermodynamic Optimization of the Cr–P and Cr–Fe–P Systems
Authors: You Zhimin , Lai Zhijie , Cui Senlin , Jiang Zhouhua , Jung In-Ho
Published: September 2024

Existing thermodynamic descriptions of the whole Cr–Fe–P system are insufficiently accurate for understanding the thermodynamic behavior of the Cr–Fe–P materials during the manufacturing process. To construct a more precise and consistent thermodynamic database of the Cr–Fe–P system, thermodynamic modeling of the Cr–P and Cr–Fe–P systems was conducted using the CALculation of PHAse Diagrams (CALPHAD) approach based on critical evaluation of the experimental data. The modified quasichemical model and compound energy formalism were employed to describe the liquid and solid solutions, respectively. The Gibbs energies of stoichiometric compounds Cr3P(s), Cr2P(s), CrP(s), and CrP2(s) were carefully determined based on reliable experimental data. The ternary (Cr,Fe)3P, (Cr,Fe)2P, and (Cr,Fe)P phosphides were modeled as solid solutions considering mutual substitution between Cr and Fe atoms. In addition, the phase equilibria of BCC_A2 and FCC_A1 solutions and the liquid phase of the ternary Cr–Fe–P system were also optimized for more accurate descriptions of existing phase equilibria and thermodynamic properties data. As an application of the present database, the experimentally unexplored thermodynamic properties and phase diagrams of the Cr–Fe–P system are predicted.
Embeddings for Efficient Literature Screening: A Primer for Life Science Investigators
Authors: Galli Carlo , Cusano Claudio , Guizzardi Stefano , Donos Nikolaos , Calciolari Elena
Published: September 2024

As the number of publications is quickly growing in any area of science, the need to efficiently find relevant information amidst a large number of similarly themed articles becomes very important. Semantic searching through text documents has the potential to overcome the limits of keyword-based searches, especially since the introduction of attention-based transformers, which can capture contextual nuances of meaning in single words, sentences, or whole documents. The deployment of these computational tools has been made simpler and accessible to investigators in every field of research thanks to a growing number of dedicated libraries, but knowledge of how meaning representation strategies work is crucial to making the most out of these instruments. The present work aims at introducing the technical evolution of the meaning representation systems, from vectors to embeddings and transformers tailored to life science investigators with no previous knowledge of natural language processing.
Capacitance–Voltage Fluctuation of SixNy-Based Metal–Insulator–Metal Capacitor Due to Silane Surface Treatment
Authors: Choi Tae-Min , Jung Eun-Su , Yoo Jin-Uk , Lee Hwa-Rim , Pyo Sung-Gyu
Published: September 2024

In this study, we analyze metal–insulator–metal (MIM) capacitors with different thicknesses of SixNy film (650 Å, 500 Å, and 400 Å) and varying levels of film quality to improve their capacitance density. SixNy thicknesses of 650 Å, 500 Å, and 400 Å are used with four different conditions, designated as MIM (N content 1.49), NEWMIM (N content 28.1), DAMANIT (N content 1.43), and NIT (N content 0.30). We divide the C–V characteristics into two categories: voltage coefficient of capacitance (VCC) and temperature coefficient of capacitance (TCC). There was an overall increase in the VCC as the thickness of the SixNy film decreased, with some variation depending on the condition. However, the TCC did not vary significantly with thickness, only with condition. At the same thickness, the NIT condition yielded the highest capacitance density, while the MIM condition showed the lowest capacitance density. This difference was due to the actual thickness of the film and the variation in its k-value depending on the condition. The most influential factor for capacitance uniformity was the thickness uniformity of the SixNy film.
A Miniaturized, Fuel-Free, Self-Propelled, Bio-Inspired Soft Actuator for Copper Ion Removal
Authors: Chimerad Mohammadreza , Borjian Pouya , Pathak Pawan , Fasano Jack , Cho Hyoung J.
Published: September 2024

We present a novel miniaturized, gear-shaped, fuel-free actuator capable of autonomously propelling itself in an aquatic environment to absorb heavy metals, such as copper ions. While hydrogel-based absorbents are promising solutions for cationic pollutant remediation, their stationary nature limits their effectiveness in areas where contaminants are unevenly distributed. To address this, we developed a bio-inspired soft actuator that mimics natural propulsion mechanisms. The Marangoni effect, driven by its inherent chemical properties, demonstrated a self-propelled motion without requiring external fuel. The proof-of-concept actuator generated a plane motion lasting up to 2 h and swept over an area approximately 400 times bigger than its size. By harnessing the chemical and optical properties of the hydrogel, we efficiently removed and quantitatively analyzed copper ions through a colorimetric method. This innovative integration of self-propelled movement and efficient copper ion absorption underscores its potential for advancing miniaturized devices in environmental remediation, paving the way for more active and efficient pollutant removal systems in challenging aquatic environments.
On the Dynamics of a Novel Liquid-Coupled Piezoelectric Micromachined Ultrasonic Transducer Designed to Have a Reduced Resonant Frequency and Enhanced Ultrasonic Reception Capabilities
Authors: Sammut Stephen , Gatt Edward , Borg Ruben P.
Published: September 2024

This paper introduces a novel design for a liquid-deployed Piezoelectric Micromachined Ultrasonic Transducer (PMUT). This design was specifically developed to resonate at a lower ultrasonic frequency than a PMUT with a circular, fully clamped diaphragm with the same diameter. Furthermore, the novel design was also optimised to enhance its ultrasonic radiation reception capabilities. These parametric enhancements were necessary to develop a PMUT device that could form part of an eventual microscale sensory device used for the Structural Health Monitoring (SHM) of reinforced concrete (RC) structures. Through these two enhancements, an eventual microscale sensor can be made smaller, thus taking up a smaller die footprint and also be able to be deployed further apart from each other. Eventually, this would reduce the developed distributed sensor system’s cost. The innovative design employed a configuration where the diaphragm was only pinned at particular points along its circumference. This paper presents results from Finite Element Modelling (FEM), as well as experimental work that was conducted to develop and test this novel PMUT. The experimental work presented involved both laser vibrometry and ultrasonic radiation lab work. The results show that when compared to a clamped diaphragm design, the novel device managed to achieve the required reduction in resonant frequency and presented an enhanced sensitivity to incoming ultrasonic radiation.
Photonic Generation of Arbitrary Microwave Waveforms with Anti-Dispersion Transmission Capability
Authors: Zhang Xinyan , Zhai Kunpeng , Zhu Sha , Wen Huashun , Liu Yu , Zhu Ninghua
Published: September 2024

We propose and demonstrate a photonic-assisted approach for generating arbitrary microwave waveforms based on a dual-polarization dual-parallel Mach–Zehnder modulator, offering significant advantages in terms of tunability of repetition rates and anti-dispersion capability. In order to generate diverse microwave waveforms, two sinusoidal radio frequency signals with distinct frequency relationships are applied to the dual-polarization dual-parallel Mach–Zehnder modulator. By adjusting the power of the applied sinusoidal radio frequency signal, the power ratio between these orthogonal polarized optical sidebands can be changed, and thereby desired radio frequency waveforms can be obtained after photoelectric conversion. In our proof-of-concept experiment, we systematically varied the repetition rate of triangular, rectangular and sawtooth waveforms. Meanwhile, we calculated the Root Mean Square Error (RMSE) to assess the approximation error in each waveform. The RMSEs are 0.1089, 0.2182 and 0.1185 for the triangular, rectangular and sawtooth microwave waveforms with repetition rate of 8 GHz, respectively. Furthermore, after passing through 25 km single mode fiber, the optical power decreased by approximately 5.6 dB, which verifies the anti-dispersion transmission capability of our signal generator.
Piezoelectric Ultrasonic Local Resonant Ultra-Precision Grinding for Hard–Brittle Materials
Authors: An Dawei , Xian Jianghui , Zhang Yi , Cheng Guoqiang , Huang Yankai , Liang Zhongwei , Huang Weiqing
Published: September 2024

Hard–brittle materials are widely used in the optics, electronics, and aviation industries, but their high hardness and brittleness make it challenging for traditional processing methods to achieve high efficiency and superior surface quality. This study aims to investigate the application of ultrasonic local resonant grinding to sapphire to improve the efficiency and meet the requirements for the optical window in the surface roughness of the material. The resonant frequency of a piezoelectric ultrasonic vibration system and the vibration amplitude of a grinding head’s working face were simulated and tested, respectively. The results of ultrasonic grinding experiments showed that the local resonant system reduced the surface roughness parameter (Ra) of sapphire to 14 nm and improved its surface flatness to 44.2 nm, thus meeting the requirements for the ultra-precision grinding of sapphire. Compared with a conventional resonant system, the surface roughness of the sapphire ground with the local resonant system was reduced by 90.79%, its surface flatness was improved by 81.58%, and the material removal rate was increased by 31.35%. These experimental results showed that ultrasonic local resonant grinding has better effects than those of conventional ultrasonic grinding in improving surface quality and increasing the material removal rate.
Lightweight Hotspot Detection Model Fusing SE and ECA Mechanisms
Authors: Chen Yanning , Li Yanjiang , Wu Bo , Liu Fang , Deng Yongfeng , Jiang Xiaolong , Lin Zebang , Ren Kun , Gao Dawei
Published: September 2024

In this paper, we propose a lightweight lithography machine learning-based hotspot detection model that integrates the Squeeze-and-Excitation (SE) attention mechanism and the Efficient Channel Attention (ECA) mechanism. These mechanisms can adaptively adjust channel weights, significantly enhancing the model’s ability to extract relevant features of hotspots and non-hotspots through cross-channel interaction without dimensionality reduction. Our model extracts feature vectors through seven convolutional layers and four pooling layers, followed by three fully connected layers that map to the output, thereby simplifying the CNN network structure. Experimental results on our collected layout dataset and the ICCAD 2012 layout dataset demonstrate that our model is more lightweight. By evaluating overall accuracy, recall, and runtime, the comprehensive performance of our model is shown to exceed that of ConvNeXt, Swin transformer, and ResNet 50.
3D Light-Direction Sensor Based on Segmented Concentric Nanorings Combined with Deep Learning
Authors: Huang Pengcheng , Wu Peijin , Guo Ziyuan , Ye Zhicheng
Published: September 2024

High-precision, ultra-thin angular detectable imaging upon a single pixel holds significant promise for light-field detection and reconstruction, thereby catalyzing advancements in machine vision and interaction technology. Traditional light-direction angle sensors relying on optical components like gratings and lenses face inherent constraints from diffraction limits in achieving device miniaturization. Recently, angle sensors via coupled double nanowires have demonstrated prowess in attaining high-precision angle perception of incident light at sub-wavelength device scales, which may herald a novel design paradigm for ultra-compact angle sensors. However, the current approach to measuring the three-dimensional (3D) incident light direction is unstable. In this paper, we propose a sensor concept capable of discerning the 3D light-direction based on a segmented concentric nanoring structure that is sensitive to both elevation angle (θ) and azimuth angle (ϕ) at a micrometer device scale and is validated through simulations. Through deep learning (DL) analysis and prediction, our simulations reveal that for angle scanning with a step size of 1°, the device can still achieve a detection range of 0∼360° for ϕ and 45°∼90° for θ, with an average accuracy of 0.19°, and DL can further solve some data aliasing problems to expand the sensing range. Our design broadens the angle sensing dimension based on mutual resonance coupling among nanoring segments, and through waveguide implementation or sensor array arrangements, the detection range can be flexibly adjusted to accommodate diverse application scenarios.