bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of the stoichiometric ratio on the material properties and the aging behavior of anhydride-cured epoxy systems
Authors: Küchler Florian , Färber Raphael , Franck Christian M 
Published: July 2023

Abstract
When partial discharge and dielectric heating effects can be excluded, comparatively little is known about the aging behavior of polymeric insulation materials under combined environmental and electric field stress. Since it was found in an earlier study that hygroelectrical stress leads to a strong reduction in the residual breakdown strength of anhydride-cured epoxy samples, the goal of this contribution is to determine if a material modification could enhance the insulation performance under hygroelectrical stress. For this purpose, epoxy samples of different stoichiometric ratios (SRs) were manufactured and hygroelectrically stressed. The material properties were evaluated by AC breakdown strength measurements as well as by Fourier-transform infrared (FTIR) spectroscopy before and after each aging sequence. Gravimetric analysis quantified the water diffusion behavior and the (steady-state) water absorption during exposure to different relative humidity levels at room temperature. The breakdown strength decreases for both increasing and decreasing SR compared to

S
R

=
95
%

. Moreover, FTIR measurements revealed that an increase of the SR leads to a higher amount of unreacted anhydride which correlates with an increasing amount of absorbed water. Thus, the mutual presence of water in the atmosphere and of unreacted anhydride in the epoxy material is identified as the main risk factor for epoxy degradation under the influence of electrical stress, since unreacted anhydride favors stronger water absorption and the presence of water inside the material is attributed to a lowering of the potential barrier for molecular bond breaking. Remarkably, the breakdown strength of non-aged samples is lower at

S
R

=
80
%

compared to

S
R

=
95
%

, but the long-term performance with respect to insulation aging is enhanced, which correlates with the non-/less-existing unreacted anhydride in the material.
Amplitude modulated feed-forward thermal drift compensation for linear and nonlinear current sensors
Authors: Ranasingh Soumyaranjan , Pradhan Tapan , Dhenuvakonda Koteswara Raju 
Published: July 2023

Abstract
The linear and nonlinear temperature responses restrict the application of Hall current sensors operating in thermal power plants and industries. The rise in temperature of electron device-based measurement causes a significant error, leading to undesirable consequences for plant operation and relay coordination. This paper investigates four Hall current sensor types with linear and nonlinear temperature responses. The Hall current sensor, which receives the magnetic excitation from the permanent magnet, exhibits a linear temperature response, and the wire-wound design exhibits a nonlinear temperature response in the temperature range of 306–376 K. The solution scheme with amplitude modulation and thermal sensor integration with interdigitated electrode design having graphene and ZnO–KMnO4 compounds as the dielectric is also proposed. The use of amplitude modulation achieves input frequency immunity with a 0.03% K−1 improvement in the temperature response of the capacitive thermal sensor. Experimental observations confirm the validity of the thermal drift compensation scheme with a 20%–99% reduction of thermal drift error with a suitable choice of a thermal sensor.
The implementation of thermal and UV nanoimprint lithography for selective area epitaxy
Authors: Hager Antonia , Güniat Lucas , Morgan Nicholas , Ramanandan Santhanu Panikar , Rudra Alok , Piazza Valerio , Fontcuberta i Morral Anna , Dede Didem 
Published: July 2023

Abstract
Semiconductor nanowires (NWs) in horizontal configuration could provide a path for scalable NW-based devices. Bottom–up large-scale manufacturing of these nanostructures by selective area epitaxy (SAE) relies on precise nanopatterning of various shapes on the growth masks. Electron beam lithography offers an extraordinary accuracy suited for the purpose. However, this technique is not economically viable for large production as it has a low throughput and requires high investment and operational costs. Nanoimprint lithography (NIL) has the potential to reduce fabrication time and costs significantly while requiring less sophisticated equipment. In this work, we utilize both thermal and UV NIL for patterning substrates for SAE, elucidating the advantages and disadvantages of each lithography technique. We demonstrate the epitaxial growth of Ge and GaAs NWs on these substrates, where we observe high-quality mono-crystalline structures. Even though both processes can produce small uniform structures suitable for SAE, our results show that UV NIL proves to be superior and enables reliable and efficient patterning of sub-100 nm mask features at the wafer scale.
Microsoft Excel powered virtual electron diffraction tube experiment as an enhanced educational tool
Authors: Bhat Vijay , Bhatt Uma Rathore 
Published: July 2023

Abstract
This paper presents a novel Microsoft Excel based virtual electron diffraction experiment, which replicates all functionality of an electron diffraction tube which is an important tool for the verification of the concept of matter waves. Unlike most of virtual labs where accessibility is mostly online; presented simulator is simply a downloadable excel file and can be used offline as a learning resource. Impact of the presented simulator on the learning was analysed by the test conducted for the control and the experimental group of students. Results of the test show the enhanced performance by the experimental group of students, indicating the positive impact of using the simulator along with conventional classroom teaching. This simulator intends to simplify the abstract quantum mechanical concept of matter waves by bringing the laboratory sort of experience in classroom.
A physical pendulum experiment with Lego, Phyphox and Tracker
Authors: Coramik Mustafa , İnanç Buket 
Published: July 2023

Abstract
In this study, a physical pendulum experiment, which is one of the basic experiments at the high school level, was carried out using Lego bricks and smartphones (Phyphox application) that students are familiar with in their daily lives. In this way, it is aimed to provide an example to students and teachers about low-cost, theory-compatible experiments that students can perform on their own in out-of-school environments, especially in mechanics. In addition, another aim of the study was to record the experiment on video and analyse it with a video analysis program (Tracker) and to compare the two methods (using a smartphone application and a video analysis program) in terms of results and usability.
Studying Kepler’s laws using GeoGebra simulations
Authors: P Matos A P , do Espírito Santo M A , S Souza P V 
Published: July 2023

Abstract
Computer simulations are essential research tools in today’s scientific world. They are also important for science teaching. Even though there are many simulators developed for didactic purposes, we narrow our attention to GeoGebra, a free software that can be easily adapted to perform physics simulations. Accordingly, we present a self-contained set of GeoGebra simulations of Kepler’s laws. Although the simulations are quite intuitive, each one is presented and its potential is discussed in detail. The set has been applied on several occasions in high school classes and the results indicate that it can be a powerful tool for teaching Kepler’s laws.
Investigating the properties of conductive clay and examining its potential as a teaching material
Authors: Tsuyuki Takashi , Iwayama Tsutomu 
Published: July 2023

Abstract
In this study, we analysed the material properties of conductive clay and verified its effectiveness as a learning material in the electrical field. Regarding the relationship between the salt content ratio and electrical conductivity, it was found that the higher the salt content ratio, the higher was the electrical conductivity. However, when the salt content ratio was approximately 18%, the salt concentration in the clay approached saturation, and the electrical conductivity hardly changed. In addition, Hall effect experiments clarified that the charge carriers of conductive clay are mainly Cl−. Furthermore, it was clarified that by mixing ‘Thermoink’ with conductive clay, heat dissipation can be visualised by changing the colour of conductive clay. From these results, it became clear that conductive clay is an effective teaching material for children to learn about electrical resistance and the Hall effect while conducting experiments.
Characterization of a 0.8 mm3 Medscint plastic scintillator detector system for small field dosimetry
Authors: Timakova Elena , Bazalova-Carter Magdalena , Zavgorodni Sergei 
Published: July 2023

Abstract

Objective. Plastic scintillator detectors (PSDs) have demonstrated ability to meet requirements of small field dosimetry. Medscint developed a 1 mm long, 1 mm diameter cylindrical PSD with effective volume of 0.8 mm3. Clinically relevant, small field dosimetric properties of this detector, combined with a novel scintillation dosimetry system—HYPERSCINT RP-200, and HYPERDOSE analysis software were evaluated in this study. Approach. This novel scintillator-based dosimetry system was characterized with 6 MV-WFF and 10 MV-FFF x-ray beams delivered by Varian TrueBeamTM linear accelerator. The detector was characterized for leakage, short-term repeatability, dose response linearity, angular response, dose rate response, and field size dependence for radiation field sizes of 0.25 × 0.25 to 10 × 10 cm2. Measured detector specific output ratios were compared with microDiamond output factors to determine small field output correction factors,

k

Q
clin

,

Q
msr

f
clin

,

f
msr

.

Main results. The dosimetry system showed excellent short-term repeatability with standard deviation of only 0.04 ± 0.01%. It demonstrated good dose linearity with variations less than 1.0% for 14.4 cGy and above. The dosimetry system was found to be independent of dose rate and angle of irradiation, with deviations for both below 0.5%. Leakage was found to be comparable to background readings. For 6 MV-WFF energy beams, detector specific output ratios for field sizes down to 1 × 1 cm2 agreed with output factors measured with PTW TN60019 microDiamond, thus,

k

Q
clin

,

Q
msr

f
clin

,

f
msr

equates to unity for these field sizes. For 10 MV-FFF energy beams, detector specific output ratios for field sizes down to 2 × 2 cm2 agreed with PTW TN60019 microDiamond output factors, thus,

k

Q
clin

,

Q
msr

f
clin

,

f
msr

equates to unity for these field sizes.

k

Q
clin

,

Q
msr

f
clin

,

f
msr

for field sizes down to 0.5 × 0.5 cm2 were determined to be within 6% of unity for both 6 MV-WFF and 10 MV-FFF energy beams. Significance. The HYPERSCINT RP-200 dosimetry system coupled with a 0.8 mm3 PSD showed excellent dosimetric properties and was found to be clinically relevant for relative dosimetry down to field sizes of 0.5 × 0.5 cm2 and potentially smaller.
The 2023 wearable photoplethysmography roadmap
Authors: Charlton Peter H , Allen John , Bailón Raquel , Baker Stephanie , Behar Joachim A , Chen Fei , Clifford Gari D , Clifton David A , Davies Harry J , Ding Cheng , Ding Xiaorong , Dunn Jessilyn , Elgendi Mohamed , Ferdoushi Munia , Franklin Daniel , Gil Eduardo , Hassan Md Farhad , Hernesniemi Jussi , Hu Xiao , Ji Nan , Khan Yasser , Kontaxis Spyridon , Korhonen Ilkka , Kyriacou Panicos A , Laguna Pablo , Lázaro Jesús , Lee Chungkeun , Levy Jeremy , Li Yumin , Liu Chengyu , Liu Jing , Lu Lei , Mandic Danilo P , Marozas Vaidotas , Mejía-Mejía Elisa , Mukkamala Ramakrishna , Nitzan Meir , Pereira Tania , Poon Carmen C Y , Ramella-Roman Jessica C , Saarinen Harri , Shandhi Md Mobashir Hasan , Shin Hangsik , Stansby Gerard , Tamura Toshiyo , Vehkaoja Antti , Wang Will Ke , Zhang Yuan-Ting , Zhao Ni , Zheng Dingchang , Zhu Tingting 
Published: July 2023

Abstract
Photoplethysmography is a key sensing technology which is used in wearable devices such as smartwatches and fitness trackers. Currently, photoplethysmography sensors are used to monitor physiological parameters including heart rate and heart rhythm, and to track activities like sleep and exercise. Yet, wearable photoplethysmography has potential to provide much more information on health and wellbeing, which could inform clinical decision making. This Roadmap outlines directions for research and development to realise the full potential of wearable photoplethysmography. Experts discuss key topics within the areas of sensor design, signal processing, clinical applications, and research directions. Their perspectives provide valuable guidance to researchers developing wearable photoplethysmography technology.
Improved reverse-bias breakdown behavior in fully-vertical GaN-on-Si Schottky barrier diodes with a thin AlN layer within the GaN drift layer
Authors: Mase Akira , Dalapati Pradip , Hayafuji Ryosuke , Kubo Toshiharu , Miyoshi Makoto , Egawa Takashi 
Published: July 2023

Abstract
In this study, we investigated the effect of inserting a 1 nm thick AlN thin-film layer in the drift layer of a GaN-on-Si Schottky barrier diode to improve the reverse-bias breakdown voltage. The breakdown voltage was significantly improved from 258 V (without an AlN layer) to 338 V (with an AlN layer placed at the bottom of the drift layer), indicating that the AlN thin layer played an important role in the breakdown voltage characteristics. Furthermore, x-ray diffraction measurements and stress evaluations indicate that the AlN thin-film layer inserted at the bottom of the drift layer can significantly reduce the film stress and improve the breakdown voltage of the device.
4D printing of shape memory polylactic acid/ethylene-glycidyl methacrylate (PLA/E-GMA) blends
Authors: Cunha Rafael Braga da , Agrawal Pankaj , Quirino Brito Louise Brasileiro , Candido Cunha Carlos Thiago , Brito Gustavo de Figueiredo , Alves de Mélo Tomás Jeferson 
Published: July 2023

Abstract
In this study, polylactide/ethylene-glycidyl methacrylate (PLA/E-GMA) binary blends were prepared via melt blending to investigate their potential for 4D printing. The aim was to enhance shape memory effects (SMEs) and dynamic responses in the printed objects by exploring different compositions, printing parameters, and temporary shapes. Several characterizations were performed, including Fourier transform infrared spectroscopy, rheological properties, dynamic mechanical analysis (DMTA), scanning electron microscopy (SEM), impact strength tests, optical microscopy (OM), and evaluation of the SME. The results revealed the successful incorporation of elastomers into the PLA matrix, as confirmed by the chemical reactivity of the PLA/E-GMA blends. The materials showed good processability and printability based on the rheological properties. DMTA analysis demonstrated improved mechanical properties and shape memory behavior in the PLA/E-GMA samples. SEM images exhibited well-dispersed elastomer particles and enhanced interfacial adhesion between the phases. The evaluation of the SME showed that the printed objects could recover their original shape upon stimulation. OM confirmed the influence of printing parameters on layer adhesion. The PLA/E-GMA (50/50) composition was selected for filament production, resulting in a high-quality filament with suitable dimensions and good printability. Overall, the incorporation of elastomers into PLA enhanced the SME and mechanical properties of the printed objects. This research contributes to the advancement of 4D printing using PLA-based materials and opens possibilities for dynamic and responsive structures in various fields.
Effect of copper and silver as a middle layer on the structural, electrical, photocatalytic, and optical properties of ZnS/metal/ZnS films for optoelectronics applications
Authors: Hasaneen M F , Mohamed W S , Taya Y A 
Published: July 2023

Abstract
In this work, we utilized the thermal vacuum evaporation technique to fabricate ZnS single-layer thin films, ZnS/Cu/ZnS (ZCZ), and ZnS/Ag/ZnS (ZAZ) multilayer thin films. The influence of the middle layer of metals like copper and silver on the physical properties of ZnS/metal/ZnS multilayers is investigated. The results of the X-ray investigation demonstrate that the samples are polycrystalline, with a cubic ZnS structure and texture (111) at 2 = 29.1°. The optical investigation using Tauc’s approach yields energy gap values of 3.76 eV, 3.68 eV, and 3.6 eV for ZnS, ZCZ, and ZAZ films, respectively. CO2 gas sensing efficiency of ZnS, ZCZ, and ZAZ films were found to be at different operating temperatures. The optimal temperatures for ZnS, ZCZ, and ZAZ thin films were determined to be 483 K, 693 K, and 693 K, respectively. Under ultraviolet (UV) irradiation, the photocatalytic activity of ZnS, ZCZ, and ZAZ films for the degradation of methylene blue were studied. The results suggest that the metal intermediate layer is significant in improving the photocatalytic capabilities of ZnS films. When compared to ZnS single layer film (degradation efficiency of 15% after 180 min of UV irradiation), ZAZ multilayer film demonstrates the highest photocatalytic activity (degradation efficiency of 50% after 180 min of UV irradiation). The mechanism of the metal middle layer’s improved UV photoactivity is briefly discussed.
Characterization and biological evaluation of new PLGA/fibrin/lignin biocomposite electrospun scaffolds
Authors: Norouzi Mohsen , Rafienia Mohammad , Hosseini Seyedmajid 
Published: July 2023

Abstract
In this study, we produced electrospun scaffolds from 10% pure PLGA solution, and 10% polyblend solutions of PLGA/Fibrin, PLGA/Lignin, and PLGA/Fibrin/Lignin with proportions of 9:1, 8:2, 7:3, 7:2:1, 6:2:2, and 5:2:3 and characterized them physiochemically and biologically. FTIR and EDX results verified the chemical composition of the fibers. All scaffolds exhibited homogenous nanostructures with fiber diameters ranging from 0.1 to 2.5 μm and the highest average fiber diameter belonged to PLGA/Lignin fibers. Increasing the lignin proportion led to a decrease in fibers diameter and a change in color to brown. Fibrin improved the hydrophobicity of the scaffolds, and the incorporation of fibrin, lignin, or fibrin/lignin improved the absorption capacity of the scaffolds (up to 91.7%). From day 45 onwards, fibrin-containing scaffolds started to degrade much faster. By day 90, PLGA/20%Fibrin/30%Lignin showed the highest degradation ratio of 82%, while PLGA/10%Lignin showed the lowest at 51.4%. All scaffolds exhibited high porosity percentage (over 78%), with porosity enhanced by increasing fibrin and decreasing lignin. The pure PLGA scaffold and PLGA/10%Lignin showed the highest stiffness and tensile strength, respectively. The addition of natural components gradually decreased the scaffolds’ tensile strength and fracture strain. MTT results showed higher absorbance reading at 490 nm for PLGA, PLGA/10%Fibrin, and all three PLGA/Lignin scaffolds from day 3 to day 7. On day 7, PLGA/10%Fibrin exhibited the highest cell viability, followed by PLGA/10%Lignin and PLGA/20%Fibrin/10%Lignin. SEM micrographs revealed the presence of h-ADSCs with spindle-like morphologies, attached and proliferated well on all scaffolds. PLGA/10%Fibrin, PLGA/10%Lignin, and PLGA/20%Fibrin/10%Lignin were selected as the preferred options from each set of scaffolds. Among them, PLGA/20%Fibrin/10%Lignin exhibited superior physical features and actively enhanced the biological responses of the cells due to its physio-mechanical signals and the advanced features of lignin, making it suitable for tissue engineering, wound dressing, drug delivery, and other biomedical applications.
Influence of temperature on the redox behaviour of binder-free CNTs-NiZnS electrode and the application in efficient energy storage devices
Authors: Mindil A , Hassan Haseebul , Hadia N M A , Mukhrish Yousef E , Iqbal Muhammad Waqas , Afzal Amir Muhammad 
Published: July 2023

Abstract
Due to their unique structure, the metal sulfides are mechanically stable, have higher conductivities, and are frequently used in energy storage devices. Here, binder-free electrodes were designed by depositing the nickel zinc sulfide (NiZnS) incorporated with carbon nanotubes (CNTs) on the nickel foam (NF). X-ray diffraction (XRD) was used to describe the crystallinity of produced CNTs-NiZnS nanostructures, and morphological investigations were performed using field emission scanning electron microscopy (FESEM). According to the electrochemical measurements, the heating of electrolyte at 80 °C resulted in considerably enhanced specific capacitance of 1475 Cg−1 (50.85 F m−2) and 666 Cg−1 (13.77 F m−2) at 1 and 2 Ag−1 current density, correspondingly. Thus demonstrating a good capacity retention of 47% at 2 Ag−1. The supercapattery (CNTs-NiZnS//AC) was designed with CNTs-NiZnS and AC, providing a specific charge capacity of 212 Cg−1 (at 2.0 Ag−1) along with energy density of 51 Wh-kg−1 at 820 W kg−1 power density. The stability of CNTs-NiZnS//AC was tested by subjecting it to 5000 successive cycles.
Grothendieck’s point of view and complexity in the black hole paradox
Authors: Patrascu Andrei T 
Published: July 2023

Abstract
These are some speculations on how Grothendieck’s point of view and the idea of complexity dynamics can come together in the problem of explaining the black hole information paradox. They are neither complete, nor final, but can seem like a new direction of research. If read as such they could prove useful to some researchers. The basic idea is that entanglement alone cannot fully account for the information extraction in black hole contexts. Complexity has been proposed as an alternative but remains a vague concept. I employ Grothendieck’s point of view to expand the idea of entanglement entropy to a categorical context in which the objects (states) and their maps are considered together and the map space has additional topological and geometric structure that intermingles with the object set of the category via Sieves, Sheafs, and Toposes.
Development of VSe2@ Cu2Se nano-composites via facile one-pot hydrothermal method for pharmaceutical applications
Authors: Al-Farraj Eida S , Alahmadi M , Mohamed W S , Alsaedi Wael H , Abu-Dief Ahmed M 
Published: July 2023

Abstract
Nanoparticles have recently gained considerable popularity due to their usage as chemotherapeutic agents. In this regard, VSe2, Cu2Se and VSe2@Cu2Se nanoparticles (NPs) were synthesized using one-pot hydrothermal method which is simple, low-cost, and environmentally friendly. The structural and microstructural information for VSe2, Cu2Se and VSe2@Cu2Se nanoparticles NPs were examined utilizing the Raman spectroscopy, Scanning Electron Microscopy (SEM), Energy-Dispersive x-ray spectroscopy (EDX), and x-ray diffraction (XRD) techniques. XRD structural investigation using the Williamson-Hall approach shows that VSe2, Cu2Se, and VSe2@Cu2Se NPs are pure crystalline phases with a cubic crystal structure, the size of the crystallites varying with the NPs’ respective compositions. The crystallite size of the VSe2@Cu2Se mixture was measured to be 25.9 nm, which is smaller than the crystallite size of either component on its own. The products were evaluated for antibacterial activity against various types of bacteria and fungi using the well diffusion method at varying doses. The same samples were then examined for anticancer activity against three distinct cell lines. When compared to their individual counterparts, the data show that the nanocomposite has a synergistic effect on antibacterial and anticancer capabilities. Amongst some of the three metal oxide nanomaterials tested, VSe2/ Cu2Se had the most antibacterial efficacy against both Gram-positive and Gram-negative bacteria.