bluuebunny/crossref_metadata_2025 huggingface dataset:
Anti-Corrosion Performance of Magnesium Potassium Phosphate Cement Coating on Steel Reinforcement: The Effect of Boric Acid
Authors: Zhang Fan , Qin Jihui , Cai Kangyi , Myers John J. , Ma Hongyan
Published: October 2024

It has recently been found that magnesium potassium phosphate cement (MKPC) paste coating applied on the surface of steel reinforcement can effectively retard the onset of corrosion and suppress corrosion reactions. However, the fast-setting nature of MKPC—which is a merit in repair—can be problematic in a practical engineering process of coating the steel reinforcement with MKPC paste. To address this problem, boric acid (H3BO3) was added as a retarder in an MKPC formulation to prolong the setting time. This work investigated the impact of boric acid (at 5% by weight of MgO) on the anti-corrosion performance of MKPC paste coating through a series of electrochemical (EC) tests. The results showed that the anti-corrosion performance of MKPC paste coating for a mild steel bar could be interfered with by the presence of boric acid. In the same testing situation (immersed in 3.5 wt.% NaCl corrosion solution), the polarization resistance and corrosion current density of the group including boric acid were inferior and exceeded the corrosion thresholds prior to the control group without boric acid. Meanwhile, the time constant phase in the frequency range from 1 Hz to 10 kHz was rarely observed, implying that the presence of boric acid probably impaired the formation of the passivation layer. This decrease in anti-corrosion performance of MKPC paste coating could be related to the larger volume fraction of pores in the range from 0.1 to 10 µm that are formed during the initial stage of coating formation.
Evaluation of Thermal and Mechanical Properties of Bi-In-Sn/WO3 Composites for Efficient Heat Dissipation
Authors: Wu Die , Ning Zhen , Zhu Yanlin , Yuan Rui
Published: October 2024

Phase change materials (PCMs) offer promising solutions for efficient thermal management in electronic devices, energy storage systems, and renewable energy applications due to their capacity to store and release significant thermal energy during phase transitions. This study investigates the thermal and physical properties of Bi-In-Sn/WO3 composites, specifically for their use as phase change thermal interface materials (PCM-TIMs). The Bi-In-Sn/WO3 composite was synthesized through mechanochemical grinding, which enabled the uniform dispersion of WO3 particles within the Bi-In-Sn alloy matrix. The addition of WO3 particles markedly improved the composite’s thermal conductivity and transformed its physical form into a putty-like consistency, addressing leakage issues typically associated with pure Bi-In-Sn alloys. Microstructural analyses demonstrated the existence of a continuous interface between the liquid metal and WO3 phases, with no gaps, ensuring structural stability. Thermal performance tests demonstrated that the Bi-In-Sn/WO3 composite achieved improved thermal conductivity, and reduced volumetric latent heat, and there was a slight increase in thermal contact resistance with higher WO3 content. These findings highlight the potential of Bi-In-Sn/WO3 composites for utilization as advanced PCM-TIMs, offering enhanced heat dissipation, stability, and physical integrity for high-performance electronic and energy systems.
In Situ Experimental Analysis and Performance Evaluation of Airport Precast Concrete Pavement System Subjected to Environmental and Moving Airplane Loads
Authors: Kim Yoo Bong , Kim Seong-Min
Published: October 2024

The behavior of airport precast concrete pavement (APCP) involving new design and construction concepts was experimentally analyzed under environmental and moving airplane loads, and the long-term performance of the APCP was evaluated using fatigue failure analysis. The strain characteristics and curling behavior of the APCP under environmental loads were comprehensively analyzed. The APCP slabs exhibited a pronounced curling phenomenon similar to conventional concrete pavement slabs. The dynamic response of the APCP subjected to impact loads was analyzed by performing heavy weight deflectometer tests. The test results confirmed that the vertical deformation of the APCP was small and within the typical range of vertical deformation of conventional concrete pavement. The dynamic strain response of the APCP under moving airplane loads was then analyzed and the strain variation during day and night times was compared. The strains during the day were found to be significantly larger than those at night under airplane loads because of the curling phenomenon of the APCP slabs. Finally, the long-term performance of the APCP was evaluated using fatigue failure analysis based on the obtained behavior. Even using the most conservative fatigue failure prediction model, the service life of the APCP was ascertained to be more than 30 years. Based on the overall results of this study, it is concluded that the APCP, which is designed to reduce slab thickness by placing reinforcing bars in the slabs via reinforced concrete structural design, exhibits typical behavior of concrete pavements and can be successfully applied to airport pavement rehabilitation.
Insight into the Pyrolysis Behaviors of Petroleum-Driven Mesophase Pitch via ReaxFF Molecular Dynamics and In Situ TG-FTIR/MS
Authors: Qin Lingyan , Zhao Li , Yuan Bo , Wang Hongwei , Liang Guojie , Li Kai , Xie Qiang , Gong Lele
Published: October 2024

Mesophase pitch is regarded as a profoundly promising candidate for the production of advanced carbon-based multifunctional materials such as carbon fibers, carbon microspheres, and carbon foams owing to its excellent intrinsic properties. Consequently, a deeper understanding of pyrolytic chemistry is indispensable for the efficient and environmentally friendly utilization of mesophase pitch. In this study, details about the structure compositions and microscopic morphologies of petroleum-driven mesophase pitch (pMP) were investigated through ultimate, FTIR, XPS, and 13C-NMR analyses. Furthermore, a large-scale molecular model of typical pMP with 11,835 atoms was constructed to unveil the comprehensive pyrolysis behaviors and the underlying reactions. Significantly, the evolution of specific chemical bonds and the decomposition of crucial molecular fragments were elucidated within an amalgamation of experimental TG-FTIR/MS and ReaxFF MD simulation. Accordingly, three fundamental reaction stages were artificially divided, including the low-temperature reaction, rapid thermal decomposition, and the molecular condensation reaction. During the rapid thermal decomposition stage, the cleavages of C–C and C–O bonds cooperatively contributed to the formation of C2H4 and H2O gaseous products. As the temperature escalated to the molecular condensation stage, the pyrolysis process was governed by the dehydrogenation condensation, accompanied by an augmentation of C–C and H–H bonds and a diminution of C–O and C–H bonds. Additionally, the rare graphitization phenomenon was observed, suggesting a remarkable degree of structural organization in pMP. Overall, the results of ReaxFF MD simulations complement experimental observations, successfully reproducing the microstructure of pMP and atomic-scale pyrolysis behavior, thereby providing invaluable insights for the rational guidance of efficient utilization of pMP and other related carbonaceous precursors.
Microwave Absorption and Magnetic Properties of M-Type Hexagonal Ferrite Ba0.95Ca0.05Fe12−xCoxO19 (0 ≤ X ≤ 0.4) at 1–18 GHz
Authors: Li Juan , Yao Hao , Huang Yuting , Wang Hongxia
Published: October 2024

In order to improve the microwave-absorption performance of barium ferrite and broaden its microwave-absorption band, BaFe12O19, Ba0.95Ca0.05Fe12O19, and Ba0.95Ca0.05Fe12−xCoxO19 (x = 0.1, 0.2, 0.3 and 0.4, respectively) hexaferrites were synthesized by the solid-state reaction method, and the influence of Co ion substitution on the phase composition, microstructure, magnetic properties, and microwave-absorption ability of the ferrites in this system was studied. Introducing minor Co ions (x < 0.2) facilitated sintering and grain growth. At x ≥ 0.2, XRD revealed the emergence of the Co2X phase alongside the BaM phase. Increasing Co ion concentration and the secondary X-phase led to slight reductions in saturation magnetization (69 to 63.5 emu/g) and substantial decline in coercivity (2107.02 to 111.21 Oe), attributed to grain size growth and Co2X’s soft magnetic nature. Notably, Co2X incorporation significantly enhanced the microwave absorption and provided a tunable absorption band from the Ku to the C band. For a sample with a thickness of 2.0 mm and a doping level of x = 0.2, a minimum reflection loss of −59.5 dB was achieved at 8.92 GHz, with an effective absorption bandwidth of 3.31 GHz (7.07–10.38 GHz). The simple preparation method and good performance make Ba0.95Ca0.05Fe12−xCoxO19 (x = 0.1, 0.2, 0.3 and 0.4, respectively) hexaferrites promising microwave-absorbing materials.
Influence of Grinding Aids on the Grinding Performance and Rheological Properties of Cementitious Systems
Authors: Kaya Yahya , Şahin Hatice Gizem , Mardani Naz , Mardani Ali
Published: October 2024

The cement industry is of great importance in terms of raw materials consumed, energy consumed, and greenhouse gases emitted. Grinding aids (GA) are used to reduce energy consumption and costs, as well as to reduce the amount of CO2 released into the environment. In this study, the effect of GA-polycarboxylate ether-based water-reducing admixture (PCE) compatibility on some fresh, rheological and hardened state properties of cementitious systems was investigated. In order to investigate the rheological properties and thixotropic behavior of the mixtures, a total of 51 cement paste mixtures were prepared, containing 4 different types (molasses, MEG, DEA and ethanol) and ratios (0.025, 0.05, 0.75 and 0.1) of GAs and 2 different ratios (0.08% and 0.16%) of PCE in addition to the control mixture. In addition, the effect of the used GAs on the grinding efficiency and compressive strength value was investigated. Additionally, the predictability of the type of GA, dosage and cure time using the Taguchi method was investigated. It was determined that the highest grinding performance was obtained in mixtures containing MEG. It was determined that in cement paste mixtures containing GAs, the dynamic yield stress and viscosity values generally decrease with the increase in PCE usage rate up to a certain value, and these values may increase if the PCE usage increases further. It was determined that such behavior is not present in cement paste mixtures containing GAs and that the structural build-up value of the mixtures generally increases with the increase in the PCE admixture usage rate. It was determined that the use of GAs had a positive effect on 28-day compressive strength.
Microstructure and Corrosion Resistance of 7075 Aluminium Alloy Composite Material Obtained from Chips in the High-Energy Ball Milling Process
Authors: Kościelniak Barbara , Groch Diana , Nowak Wojciech J. , Drajewicz Marcin , Kwolek Przemysław
Published: October 2024

The high-energy ball milling process was applied to fabricate a composite material from 7075 aluminium alloy milling chips, silicon carbide, and titanium dioxide powders. Raw materials were ground, and the obtained powders were cold pressed and sintered. It was demonstrated that this method can be used in the recycling of aluminium alloy scrap characterised by a high surface-to-volume ratio, and also that chemical removal of the oxide layer from chips is not necessary. The finest particles, with 50 vol.% of their population below 36 μm, were obtained after grinding for 60 min at a 1000 rpm rotational speed. Such an intensive grinding was necessary to fabricate the compact composite material with a homogeneous microstructure and a low porosity of 0.7%. The corrosion resistance of the composites was studied in 3.5 wt.% NaCl solution using cyclic voltammetry and electrochemical impedance spectroscopy, and corrosion rates in the range of ca. 342 and 3 μA∙cm−2 were obtained. The corrosion mechanism includes aluminium alloy dissolution at the matrix/reinforcement interphase and around intermetallic particles localised within the matrix grains.
Device Applications Enabled by Bandgap Engineering Through Quantum Dot Tuning: A Review
Authors: Lee Ho Kyung , Park Taehyun , Yoo Hocheon
Published: October 2024

Quantum dots (QDs) are becoming essential materials for future scientific and real-world applications, owing to their interesting and distinct optical and electrical properties compared to their bulk-state counterparts. The ability to tune the bandgap of QDs based on size and composition—a key characteristic—opens up new possibilities for enhancing the performance of various optoelectronic devices. These advances could extend to cutting-edge applications such as ultrawide-band or dual-band photodetectors (PDs), optoelectronic logic gates, neuromorphic devices, and security functions. This paper revisits the recent progress in QD-embedded optoelectronic applications, focusing on bandgap tunability. The current limitations and challenges in advancing and realizing QD-based optoelectronic devices are also discussed.
A Study of the Possibility of Producing Annealed and Metallized Pellets from Titanomagnetite Concentrate
Authors: Dmitriev Andrey N. , Vitkina Galina Y. , Zlobin Victor G. , Vyaznikova Elena A. , Marshuk Larisa A. , Burova Yulia E. , Alektorov Roman V. , Kataev Vladimir V.
Published: October 2024

The current intensive development of steelmaking is being impeded by a scarcity of pure scrap. The potential to replace pure scrap with metallized raw materials that are naturally alloyed with vanadium and titanium, such as annealed unfluxed titanomagnetite pellets, could facilitate the achievement of key objectives in metallurgical development, particularly in the smelting of electric steel. The objective of this research was to produce annealed and metallized pellets from titanomagnetite concentrate under laboratory conditions, with the intention of further processing them as a commercial product in a blast furnace or as an intermediate product for the production of hot briquetted iron (HBI). The results demonstrate that pellets derived from titanomagnetite concentrate exhibit sufficient compressive strength (up to 300 kg/pellet) and a degree of metallization exceeding 90%, which aligns with the requirements for electric steelmaking. The suitability of pellets derived from titanomagnetite concentrate for use in both blast furnaces and metallization processes has been corroborated.
Magnetic Memory Effects in BaFe2(As0.68P0.32)2 Superconducting Single Crystal
Authors: Badea (Ionescu) Alina M. , Ivan Ion , Miclea Corneliu F. , Crisan Daniel N. , Galluzzi Armando , Polichetti Massimiliano , Crisan Adrian
Published: October 2024

Among many iron-based superconductors, isovalently substituted BaFe2(As1−xPx)2 displays, for x ≈ 0.3, apart from the quite usual Second Magnetization Peak (SMP) in the field dependence of the critical current density, an unusual peak effect in the temperature dependence of the critical current density in the constant field, which is related to the rhombic-to-square (RST) structural transition of the Bragg vortex glass (BVG). By using multi-harmonic AC susceptibility investigations in three different cooling regimes—field cooling, zero-field cooling, and field cooling with measurements during warming up—we have discovered the existence of a temperature region in which there is a pronounced magnetic memory effect, which we attributed to the direction of the structural transition. The observed huge differences in the third harmonic susceptibility at low and high AC frequencies indicates the difference in the time-scale of the structural transition in comparison with the timescale of the vortex excitations. Our findings show that the RST influence on the vortex dynamics goes beyond the previously observed influence on the onset of the SMP.
Electrical and Dielectrical Properties of Composites Based on Alumina and Cyclic Olefin Copolymers
Authors: Ionete Eusebiu Ilarian , Visse Artur , Andrei Radu Dorin , Petreanu Mirela Irina , Spiridon Stefan Ionut , Ionete Roxana Elena
Published: October 2024

Understanding the performance of polymer dielectrics at different temperatures is becoming increasingly important due to the rapid development of electric cars, electromagnetic devices, and new energy production solutions. Cyclic olefin copolymers (COCs) are an attractive material due to their low water absorption, good electrical insulation, long-term stability of surface treatments, and resistance to a wide range of acids and solvents. This work focused on the dielectric and electrical properties of cyclic olefin copolymer (COC)/Al2O3 composites over a wide range of temperature and frequency domains, from room temperature to cryogenic temperatures (around 125 K). Permittivity, electrical conductivity, and electrical modulus are given consideration. A composite of up to 50% Al2O3 mixed with COC was prepared via a conventional melt-blending method. The final samples were formed in sheets and processed using injection and extrusion moldings. It was found that formulations with Al2O3 concentrations ranging from 10 to 50% resulted in higher electrical conductivity while maintaining the viscosity of the composite at a level acceptable for polymer-processing machinery. Our data show that COC/alumina composites present substantial potential as materials for high-frequency applications, even at the regime of cryogenic temperatures.
Elimination of Ethanol for the Production of Fucoidans from Brown Seaweeds: Characterization and Bioactivities
Authors: Saravana Periaswamy Sivagnanam , Karuppusamy Shanmugapriya , Rai Dilip K. , Wanigasekara Janith , Curtin James , Tiwari Brijesh K.
Published: October 2024

Fucoidan, a sulphated polysaccharide from brown seaweed composed of several monosaccharides, has been stated to have several bioactive properties such as antioxidant, antiviral, anticancer, antithrombic, anti-inflammatory, and immunomodulatory effects. This paper provides research findings on green extraction methods, structural analysis of fucoidan, and its associated bioactivities. Fucoidans from brown seaweeds, Fucus vesiculosus and Ascophyllum nodosum, were extracted using green solvents such as citric acid (CA) followed by MWCO (molecular weight cut-off) filtration to obtain high-purity polysaccharides. The presence of functional groups typical to fucoidans, namely, fucose, sulfate, and glycosidic bonds, in the extracts were confirmed through the data obtained from FTIR (Fourier-transform infrared spectroscopy), TGA (thermogravimetric analysis), DSC (differential scanning calorimetry), and solid-state CP–MAS (cross-polarization magic angle spinning) analysis. The MWCO analysis identified that the >300 kDa fraction can have better content of fucoidan (FV-CA 79.16%, FV-HCl 63.59%, AN-CA 79.21%, AN-HCl 80.70%) than the conventional extraction process. Furthermore, the >300 kDa fraction showed significantly higher antioxidant activities compared to crude fucoidan extracts. Crude fucoidan extracts showed significant inhibition of cell viability in human lung (A459 lung carcinoma cells) and colorectal adenocarcinoma (Caco-2) cells at higher concentrations. The fucoidan extracted with green solvents and avoiding alcohol-based precipitation has substantial antioxidant/antitumor action, so, due to this activity, it can be employed as functional foods in food applications.
The Value of Parental Karyotyping in Recurrent Pregnancy Loss Lies in Individual Risk Assessments
Authors: Popescu-Hobeanu Gabriela , Serban Sosoi Simona , Cucu Mihai , Streață Ioana , Dobrescu Amelia , Pleșea Răzvan , Costache Anca Lelia , Iordache Andreea , Petre-Mandache Bianca , Tudorache Ștefania , Comănescu Alexandru , Iliescu Dominic , Burada Florin
Published: October 2024

Background and Objectives: Recurrent pregnancy loss (RPL) is a multifactorial condition, encompassing genetic, anatomical, immunological, endocrine, as well as infectious and environmental factors; however, the etiology remains elusive in a substantial number of cases. Genetic factors linked to RPL include parental karyotype abnormalities (e.g., translocations, inversions, copy number variants), an increase in sperm aneuploidy, fetal microchimerism, severe skewing of X chromosome inactivation, and various gene polymorphisms. Our study aims to explore the value of routine conventional parental karyotyping in couples with RPL. Materials and Methods: A total of 213 couples (426 individuals) with a history of RPL were enrolled in this retrospective study. The peripheral blood samples included in this study were referred to the Human Genomics Laboratory of the University of Medicine and Pharmacy in Craiova, Romania, for conventional cytogenetic analysis between January 2013 and December 2023, by the Outpatient Medical Genetics Clinic of the Emergency Clinical County Hospital of Craiova. Chromosome analysis was performed using standard protocols and karyotypes were reported according to ISCN. Results: Out of 426 patients provided with conventional G-banded chromosome analysis, 410 had a normal karyotype (96.2%) and 16 had chromosome abnormalities (3.8%). The most common chromosomal abnormalities were reciprocal and Robertsonian translocations, with chromosomes 8, 11, 14, and 21 being most frequently involved. A single numerical anomaly was detected (47,XYY). One or multiple chromosomal polymorphisms were identified in 104 subjects (24.4%). In addition, we conducted a stratified analysis of the unselected group and detected chromosome abnormalities in only four cases (0.94%). Conclusions: Our results are consistent with recommendations for paternal karyotyping after an individual risk assessment in instances such as a previous live birth with congenital anomalies and/or the detection of unbalanced chromosomes or a translocation in product of conception or chorionic villi/amniotic fluid samples. In the absence of a positive history, blindly karyotyping couples may prove too expensive and labor intensive, while providing no information on fertility status or live birth rates.
Trends in Global Burden of Alzheimer’s Disease and Other Dementias Attributable to High Fasting Plasma Glucose, 1990–2021
Authors: Ilic Irena , Jakovljevic Vladimir , Zivanovic Macuzic Ivana , Ravic-Nikolic Ana , Ilic Milena , Sorak Marija , Milicic Vesna
Published: October 2024

Background and Objectives: Alzheimer’s disease and other dementias represent some of the leading public health concerns worldwide. This study aimed to assess the global burden of Alzheimer’s disease and other dementias attributable to high fasting plasma glucose in the last decades. Materials and Methods: A descriptive epidemiological study was conducted. The Global Burden of Disease (GBD) study data about deaths and Disability-Adjusted Life Years (DALYs) were used. All figures were presented as age-standardized rates (ASRs). The average annual percent change (AAPC) was computed using the Joinpoint regression analysis. Also, age-period-cohort analysis was performed. Results: A total of 2 million deaths from Alzheimer’s disease and other dementias were reported worldwide in 2021, whereby the total number deaths from Alzheimer’s disease and other dementias attributable to high fasting plasma glucose was 290,032 (98,900 males and 191,132 females) in 2021. The highest ASRs of burden of Alzheimer’s disease and other dementias attributable to high fasting plasma glucose were found in Afghanistan, Iraq, Morocco, Qatar, and the United States of America, while the lowest ASRs were in Belarus and Mongolia. From 1990 to 2021, a significant increase (p < 0.001) was noted in ASRs of deaths and DALYs for Alzheimer’s disease and other dementias attributable to high fasting plasma glucose. Looking at the GBD regions, the trends in ASRs for mortality and for DALYs of Alzheimer’s disease and other dementias attributable to high fasting plasma glucose between 1990 and 2021 showed a growth 10-fold faster in High-income North America (AAPC = 2.0%, for both equally) and Central Asia (AAPC = 2.4% and AAPC = 2.5%, respectively) than in the region of High-income Asia Pacific (AAPC = 0.1% and AAPC = 0.2%, respectively). The relative risk of mortality and DALYs for Alzheimer’s disease and other dementias attributable to high fasting plasma glucose demonstrated statistically significant (p < 0.0001) period and cohort effects, and net drift and local drifts. Conclusions: This study showed an increase in the global burden of Alzheimer’s disease and other dementias attributable to high fasting plasma glucose in the last decades. Future successful entire-population strategies targeting high fasting plasma glucose may reduce the burden of a wide range of these diseases.
Prevalence of Obesity and Its Associated Comorbidities in Adults with Asthma: A Single-Center Study in Saudi Arabia
Authors: Alghamdi Abdulrhman S. , Alwadeai Khalid S. , Almeshari Mohammed A. , Alhammad Saad A. , Alsaif Sulaiman S. , Alshehri Wael A. , Alahmari Mushabbab A. , Alanazi Turki M. , Siraj Rayan A. , Abuguyan Fahad , Alotaibi Tareq F. , Algarni Saleh S.
Published: October 2024

Background and Objectives: Asthma is associated with several comorbidities, one of which is obesity. The worldwide increase in obesity has been accompanied by a parallel rise in asthma prevalence, with obesity recognized as a significant risk factor for both the development and severity of asthma. Obesity is often linked to various comorbidities, which can complicate asthma management and lead to poorer clinical outcomes. This study aims to investigate the prevalence of obesity and its comorbidities in adults with asthma in a single center in Saudi Arabia, providing an overview of the associated health implications. Materials and Methods: This single-center, retrospective study aimed to assess the prevalence of obesity and other comorbidities in asthma patients. Data were collected from King Khalid University Hospital in Saudi Arabia between July 2023 and December 2023. Results: This study revealed that 72.1% of asthma patients were either obese or overweight. Female patients had significantly higher BMI values compared to males. Our study revealed that 38.21% of female asthma patients (mean age = 57 ± 13.85 years) had comorbidities compared to 24.14% of male asthma patients (mean age = 59 ± 14.02 years). Furthermore, the proportion of obese asthmatic patients with comorbidities was significantly greater than those without comorbidities. Conclusions: This study investigates obesity prevalence and associated comorbidities in adult asthmatics in a single center in Saudi Arabia. The findings reveal a 72.1% rate of obesity and overweight among asthmatic patients, with higher BMI and comorbidity prevalence in females. These results underscore the need for targeted interventions addressing obesity and comorbidities, especially in female asthmatics.
A Review on Resonant MEMS Electric Field Sensors
Authors: Wang Guijie , Yang Pengfei , Chu Zhaozhi , Ran Lifang , Li Jianhua , Zhang Bo , Wen Xiaolong
Published: October 2024

Electric field sensors (EFSs) are widely used in various fields, particularly in accurately assessing atmospheric electric fields and high-voltage power lines. Precisely detecting electric fields enhances the accuracy of weather forecasting and contributes to the safe operation of power grids. This paper comprehensively reviews the development of micro-electromechanical system (MEMS) resonant EFSs, including theoretical analysis, working principles, and applications. MEMS resonant EFSs have developed into various structures over the past decades. They have been reported to measure electric field strength by detecting changes in the induced charge on the electrodes. Significant advancements include diverse driving and sensing structures, along with improved dynamic range, sensitivity, and resolution. Recently, mode localization has gained attention and has been applied to electric field sensing. This paper reviews the performances and structures of MEMS resonant EFSs over recent decades and highlights recent advances in weakly coupled resonant EFSs, offering comprehensive guidance for researchers.
Influence of Hydration and Temperature on the NaxCO2 Based Transducer Voltage
Authors: Zărnescu George-Claudiu , Lavasani Esmaeil Jalali , Pîslaru-Dănescu Lucian , Stamatin Ioan
Published: October 2024

This paper presents an experimental approach to maximizing the voltage generated by NaxCoO2 and improving the overall efficiency of the p-type thermoelectric leg by doping with Na up to x = 0.88. Two samples with different geometries were tested, each measured with and without an additional magnetic field applied in the direction of the temperature gradient. The properties of sodium cobaltite in response to hydration were explored, at temperatures between 300 and 380 K. Water injection boosted the current and power up to 75–100 µW at a temperature of 350–360 K. This power boost can be attributed to an electron-ion fluid flow pattern maintained by the longitudinal thermomagnetic effect and by water molecules forming hydrogen bonds with oxygen atoms in the CoO2 layers, inside the material. An electronic circuit was designed to boost the voltage to the desired level, for three or more sodium cobaltite samples mounted in parallel, and to store the energy in a supercapacitor. The output voltage and resistivity change of sodium cobaltite samples can be readily used as a humidity and temperature-sensing element in a transducer when paired with an appropriate electronic conditioning scheme.
Numerical Analysis of the Cell Droplet Loading Process in Cell Printing
Authors: Wang Yankun , Pang Fagui , Lai Shushan , Cai Renye , Lai Chenxiang , Yu Zexin , Zhu Yiwei , Wu Min , Zhang Heng , Kong Chunyu
Published: October 2024

Cell printing is a promising technology in tissue engineering, with which the complex three-dimensional tissue constructs can be formed by sequentially printing the cells layer by layer. Though some cell printing experiments with commercial inkjet printers show the possibility of this idea, there are some problems, such as cell damage due the mechanical impact during cell direct writing, which include two processes of cell ejection and cell landing. Cell damage observed during the bioprinting process is often simply attributed to interactions between cells and substrate. However, in reality, cell damage can also arise from complex mechanical effects caused by collisions between cell droplets during continuous printing processes. The objective of this research is to numerically simulate the collision effects between continuously printed cell droplets within the bioprinting process, with a particular focus on analyzing the consequent cell droplet deformation and stress distribution. The influence of gravity force was ignored, cell droplet landing was divided into four phases, the first phase is cell droplet free falling at a certain velocity; the second phase is the collision between the descending cell droplet and the pre-existing cell droplets that have been previously printed onto the substrate. This collision results in significant deformation of the cell membranes of both cell droplets in contact; the third phase is the cell droplet hitting a rigid body substrate; the fourth phase is the cell droplet being bounced. We conducted a qualitative analysis of the stress and strain of cell droplets during the cell printing process to evaluate the influence of different parameters on the printing effect. The results indicate that an increase in jet velocity leads to an increase in stress on cell droplets, thereby increasing the probability of cell damage. Adding cell droplet layers on the substrate can effectively reduce the impact force caused by collisions. Smaller droplets are more susceptible to rupture at higher velocities. These findings provide a scientific basis for optimizing cell printing parameters.
Surface Modification of Heterojunction with Intrinsic Thin Layer Solar Cell Electrode with Organosilane
Authors: Chen Bing-Mau , Chen Chih-Hung , Ying Shang-Ping
Published: October 2024

Solar cell (SC) technologies, which are essential in the transition toward sustainable energy, utilize photovoltaic cells to convert solar energy into electricity. Of the available technologies, heterojunction with intrinsic thin-layer (HIT) solar cells offers high efficiency and reliability. The current study explored the enhancement of HIT solar cell performance through the use of 3-aminopropyltrimethoxysilane (APTMS) self-assembled monolayers (SAMs) on the surface of the cells’ indium tin oxide (ITO) layer. Photoluminescence mapping revealed greater brightness and photocurrent in the HIT sample treated with APTMS SAMs, with the results indicating more favorable optical and electrical properties. The application of APTMS SAMs led to higher open-circuit voltage, fill factor, maximum power output, and efficiency by passivating the ITO surface and achieving energy level alignment, thereby enhancing the charge carrier dynamics. These findings demonstrate the potential of APTMS SAMs to improve HIT solar cell efficiency and reliability.
The Simulation of Mode Control for a Photonic Lantern Adaptive Amplifier
Authors: Ze Yuxuan , Liu Pengfei , Zhang Hanwei , Hu Yanyang , Ding Lianchuang , Yan Baozhu , Zhang Jiangbin , Zhou Qiong , Liu Wenguang
Published: October 2024

A photonic lantern is a low-loss device that connects a single multimode waveguide to multiple single-mode waveguides and can enhance the beam quality of a fiber laser by adaptively controlling the optical parameters (amplitude, phase, polarization) at the input. In this work, we combined the gains and losses of individual modes within the fiber amplifier and introduced a mode content parameter at the amplifier’s output as an evaluation function to simulate mode control effects. Mode competition within the gain fiber can degrade the control effect of the fundamental mode and lead to it taking a longer time for the control to converge. Optimal parameters, such as the gain fiber length and pumping method, were identified to improve control effectiveness. Specifically, an optimal gain fiber length of 8 m was determined, and backward pumping was found to achieve higher pumping efficiency and better control results. The system demonstrated significant power amplification potential and could stabilize mode control under different pumping powers ranging from 50 W to 5 kW. In conclusion, our research demonstrates that an adaptive fiber amplifier based on a photonic lantern can achieve a stable, high-power, large-mode-field, near-fundamental-mode output from the gain fiber. Although mode competition within the gain fiber can degrade the control effect of the fundamental mode and cause the control to take a longer time to converge, these aspects should be further studied to improve the control’s effectiveness. These findings contribute to the development of advanced simulation models that guide high-power mode control experiments and deepen our understanding of physical processes in science and technology.
Multifunctional Metasurface with PIN Diode Application Featuring Absorption, Polarization Conversion, and Transmission Functions
Authors: Nobre Francisco D. M. , de Sousa Thayana M. L. , Campos Antônio L. P. S. , da Silva Maurício W. B.
Published: October 2024

The objective of this paper is to explore the potential of integrating three distinct functionalities into a thin, single-layer metasurface. Specifically, the study introduces a metasurface design that combines absorption, polarization conversion, and transmission capabilities. The proposed structure consists of a double square loop disposed on a dielectric substrate, which is covered by a superstrate. In this study, the traditional ground plane was replaced with a periodic array, selectively reflecting frequencies of interest. Then, the absorption and polarization conversion characteristics were achieved by introducing the resonators in the front layer. By introducing asymmetry to the resonators and integrating PIN diodes for control, we demonstrated that the metasurface could efficiently absorb electromagnetic waves (with PIN diodes in the ON state), convert polarization (with PIN diodes in the OFF state), and enable signal transmission in a different frequency range. The numerical results indicated excellent performance in both absorption and polarization conversion. At a frequency of 3.05 GHz, the absorption rate reached 97%, while a polarization conversion rate of 98% was achieved at the resonance frequency of 4.37 GHz. Moreover, the proposed structure exhibited a thickness of λ/30.7 at the absorption peak.
Quick-Delivery Mold Fabricated via Stereolithography to Enhance Manufacturing Efficiency
Authors: Lee Jae Hyang , Park Seonghwan , Lim Jeon Taik , Yoon Hyung Sun , Choi Jae Won , Ha Cheol Woo , Park Jiyong
Published: October 2024

The ever-growing demand for reducing costs and decreasing the time to market in today’s plastics industry makes rapid tooling and rapid prototyping highly researched areas. Stereolithography (SLA)-manufactured injection mold inserts make it possible to produce prototype parts rapidly and cost-effectively. To utilize SLA in the injection molding industry, two steps have to be considered. The first is to identify suitable SLA process and post-thermal curing process parameters to enhance the mechanical and thermal characteristics. The second is to verify the applicability of SLA-manufactured molds for use in the injection molding industry. IA comprehensive study was performed to find the optimum process parameters for an SLA mold with excellent mechanical and thermal properties and to verify the applicability of the mold. First of all, the mechanical and thermal properties of samples manufactured based on various laser powers and heat treatment at different temperatures were analyzed with a tensile test, DSC, and TMA according to the degree of cure. On the basis of the results from those tests, an SLA mold was designed and fabricated with the optimum mechanical and thermal properties. In addition, the SLA mold was assembled into an injection machine, and an injection molding test was conducted. The SLA mold endured during the injection cycle, and 500 shots were successfully injected without damaging the mold, which resulted in reaching the quick-delivery mold standard. Finally, we demonstrate that SLA is an effective technology to produce molds for use in the injection molding industry.
3D-Printed Multi-Axis Alignment Airgap Dielectric Layer for Flexible Capacitive Pressure Sensor
Authors: Ko Jeong-Beom , Kim Soo-Wan , Kim Hyeon-Beom , Jeong Hyeon-Yun , Moon Su-Yeong , Yang Young-Jin
Published: October 2024

Flexible pressure sensors are increasingly recognized for their potential use in wearable electronic devices, attributed to their sensitivity and broad pressure response range. Introducing surface microstructures can notably enhance sensitivity; however, the pressure response range remains constrained by the limited volume of the compressible structure. To overcome this limitation, this study implements an aligned airgap structure fabricated using 3D printing technology. This structure, designed with a precisely aligned triaxial airgap configuration, offers high deformability under pressure, substantially broadening the pressure response range and improving sensitivity. This study analyzes the key structural parameters—the number of axes and pore size—that influence the compressibility and stability of the dielectric material. The results indicate that the capacitive pressure sensor with an aligned airgap structure, manufactured via 3D printing, exhibits a wide operating pressure range (50 Pa to 500 kPa), rapid response time (100 ms), wide limit of detection (50 Pa), and approximately 21 times enhancement in sensitivity (~0.019 kPa−1 within 100 kPa) compared with conventional bulk structures. Furthermore, foot pressure monitoring trials for wearable sensor applications demonstrated exceptional performance, indicating the sensor’s suitability as a wearable device for detecting plantar pressure. These findings advocate for the potential of 3D printing technology to supplant traditional sensor manufacturing processes.
Effect of Synthetic Polypeptide–Bio-Surfactant Composition on the Formation and Stability of Foams
Authors: Kosior Dominik , Wiertel-Pochopien Agata , Morga Maria , Witkowski Łukasz , Zawala Jan
Published: October 2024

In recent decades, numerous studies have focused on finding environmentally friendly substitutes for commonly used petrochemical-based compounds. This paper explores the potential use of poly-L-lysine/rhamnolipids and poly-L-glutamic acid/ethyl lauroyl arginate mixtures, for foam formation and stabilization. Two complementary methods were employed to investigate the synergistic and antagonistic effects of these mixed polyelectrolyte/surfactant systems: (1) the thinning and rupture of thin foam films formed under dynamic conditions were monitored using a dynamic fluid-film interferometer (DFI), and (2) foamability tests were conducted using a standard dynamic foam analyzer (DFA). The results demonstrated that adding polyelectrolyte to an oppositely charged surfactant primarily induces a synergistic effect, enhancing foaming properties and extending foam lifetime. Furthermore, interferometric methods confirmed improved stability and slower drainage of thin foam films in systems containing synthetic polypeptides.
Stereodivergent Synthesis of Aldol Products Using Pseudo-C2 Symmetric N-benzyl-4-(trifluoromethyl)piperidine-2,6-dione
Authors: Yada Rina , Kawasaki-Takasuka Tomoko , Yamazaki Takashi
Published: October 2024

The present article describes the successful performance of crossed aldol reactions of the CF3-containing pseudo-C2 symmetric cyclic imide with various aldehydes. The utilization of HMPA as an additive attained the preferential formation of the anti-products in good to excellent yields, which contrasts with our previous method without this additive, proceeding to furnish the corresponding syn-isomers. The effective participation of ketones and α,β-unsaturated carbonyl compounds in reactions with this imide was also demonstrated to expand the application of this imide.
Anti-Cancer Strategy Based on Changes in the Role of Autophagy Depending on the Survival Environment and Tumorigenesis Stages
Authors: Lee Michael , Kim Hye-Gyo
Published: October 2024

Autophagy is a crucial mechanism for recycling intracellular materials, and under normal metabolic conditions, it is maintained at low levels in cells. However, when nutrients are deficient or under hypoxic conditions, the level of autophagy significantly increases. Particularly in cancer cells, which grow more rapidly than normal cells and tend to grow in a three-dimensional manner, cells inside the cell mass often face limited oxygen supply, leading to inherently higher levels of autophagy. Therefore, the initial development of anticancer drugs targeting autophagy was based on a strategy to suppress these high levels of autophagy. However, anticancer drugs that inhibit autophagy have not shown promising results in clinical trials, as it has been revealed that autophagy does not always play a role that favors cancer cell survival. Hence, this review aims to suggest anticancer strategies based on the changes in the role of autophagy according to survival conditions and tumorigenesis stage.
BODIPY Compounds Substituted on Boron
Authors: Bogomolec Marko , Glavaš Mladena , Škorić Irena
Published: October 2024

BODIPY compounds are important organic dyes with exceptional spectral and photophysical properties and numerous applications in different scientific fields. Their widespread applications have flourished due to their easy structural modifications, which enable the preparation of different molecular structures with tunable spectral and photophysical properties. To date, researchers have mostly devoted their efforts to modifying BODIPY meso-position or pyrrole rings, whereas the substitution of fluorine atoms remains largely unexplored. However, chemistry of the boron atom is possible, and it enables tuning of the photophysical properties of the dyes, without tackling their spectral properties. Furthermore, modifications of boron affect the solubility and aggregation propensity of the molecules. This review article highlights methods for the preparation of 4-substituted compounds and the most important reactions on the boron of the BODIPY dyes. They were divided into reactions promoted by Lewis acid (AlCl3 or BCl3), or bases such as alkoxides and organometallic reagents. By using these two methodologies, it is possible to cleave B–F bonds and substitute them with B–C, B–N, or B–O bonds from different nucleophiles. A special emphasis in this review is given to still underdeveloped photochemical reactions of the boron atom of BODIPY dyes. These reactions have the potential to be used in the development of a new line of BODIPY photo-cleavable protective groups (also known as photocages) with bio-medicinal and photo-pharmacological applications, such as drug delivery.
Evaluation of Cytotoxic Activity of Cell Biomass from Eryngium planum and Lychnis flos-cuculi on Melanoma Cancer Cell
Authors: Hermosaningtyas Anastasia Aliesa , Totoń Ewa , Lisiak Natalia , Kruszka Dariusz , Budzianowska Anna , Kikowska Małgorzata
Published: October 2024

Melanoma is a malignant neoplasm of melanocytes in the skin, and its occurrence is increasing annually. Plant-based products contain active compounds with low toxicity and are accessible alternatives for melanoma cancer treatment. The biotechnology approach for obtaining plant-based products provides continuity and allows the high-yield production of phytochemically uniform biomass. The callus biomass of Eryngium planum L. and Lychnis flos-cuculi L. was induced on Murashige and Skoog (MS) medium supplemented with growth regulators. A combination of 3.0 mg/L of 3,6-dichloro-2-methoxybenzoic acid (dicamba) and 0.3 mg/L of 1-phenyl-3-(1,2,3-thiadiazol-5-yl)urea—(thidiazuron) was used to obtain E. planum callus. Meanwhile, the callus of L. flos-cuculi was cultivated on MS medium with 2.0 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D). Methanolic extracts (EpME and LFcME), including 40% MeOH fractions (Ep40MF and LFc40MF) and 80% MeOH fractions (Ep80MF and LFc80MF), of E. planum and L. flos-cuculi cell biomass were prepared. Their cytotoxicity activity was assessed in human fibroblast cells (MRC-5) and human melanoma cells (MeWo) by direct cell counting and 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. Qualitative analyses using thin-layer chromatography and UPLC-HRMS/MS chromatograms showed the presence of phenolic acids and saponins within the extracts and fractions of both cell biomasses. LFc80MF and Ep80MF showed the strongest toxicity against the MeWo cell line, with IC50 values of 47 ± 0.5 and 52 ± 4 μg/mL after 72 h of treatment. EpME and LFcME had IC50 values of 103 ± 4 and 147 ± 4 µg/mL, respectively. On the other hand, Ep40MF and LFc40MF were less toxic against the MeWo cell line compared to the extracts and 80% MeOH fractions, with IC50 values of 145 ± 10 and 172 ± 7 µg/mL. This study suggests that the obtained extracts and fractions of E. planum and L. flos-cuculi cell biomass potentially possess significant cytotoxic activity against MeWo cells, which work in a time and dose-dependent manner. Although the extracts and 80% MeOH fractions were more potent, the 40% MeOH was shown to be more selective against the MeWo than the control MRC-5 cells.