bluuebunny/crossref_metadata_2025 huggingface dataset:
British environmental foreign policy identity post-Brexit: environment and climate policy
Authors: Burns Charlotte
Published: July 2023

Since the 2016 referendum on leaving the European Union (EU), the United Kingdom (UK) government has been keen to persuade commentators and stakeholders that Brexit will not be bad for the UK’s environment. Rather in line with the role of Britain as a great power, the government has suggested that when it comes to the environment the UK can be a global superpower, leading other nations in its pursuit of ambitious environmental policy goals. This new environmental foreign policy role orientation has been articulated through the concept of ‘Green Brexit’ and showcased via the chairing of a major Climate Change Conference (the United Nations Framework Convention on Climate Change, Conference of the Parties (COP) 26) in Glasgow in 2021. However, whilst there was a flurry of policy activity around COP26, overall ‘Green Brexit’, has yet to be underpinned by coherent and credible domestic policy commitments necessary for effective international environmental leadership.
Improved surface acidity of niobium doped tungstated-zirconia solid acid catalyst over production of 5-hydroxymethylfurfural
Authors: Wang Xiaojun , Lu Ni , Fu Yuanyi , Lu Chang , Guan Meili , Wang Kunhua , Yu Hao
Published: July 2023

The 5-hydroxymethylfurfural (5-HMF) acts as an important chemical intermediate to bridge the biomass resources and industrial applications, which shows the potential for green development. However, the performance of biomass materials conversion to 5-HMF is still limited in the green solvent. Herein, an effective approach is reported to prepare the highly efficient solid acid catalysts, NbOx/WOy-ZrO2, to improve fructose conversion. It is found that the introduction of Nb results in the generation of the niobium oxides, which improves acid sites and tunes the ratios of Brønsted acid and Lewis acid on the surface of the WOy-ZrO2 support. With the acidity improvement and increasing acid sites of the NbOx/WOy-ZrO2, the highest fructose conversion is 99% in water. Meanwhile, the 5-HMF yield and the selectivity are also as high as 50.1% and 50.7% under the reaction temperature of 180 °C for a short reaction time of 30 min. The proposed NbOx/WOy-ZrO2 catalyst strategy will not only open a new way for designing the solid acid catalysts to achieve high performance of the 5-HMF in the water, but also promote the green production of biomass and sustainable development in the future.
Electrochemically responsive materials for energy-efficient water treatment and carbon capture
Authors: Shen Kai , Mathur Anmol , Liu Yayuan , Mao Xianwen
Published: July 2023

Electrochemically responsive materials (ERMs) that respond to external electrical stimuli offer advanced control over physio-chemical processes with a high degree of tunability and flexibility. Recently, the use of ERMs in environmental remediation processes has increased to address the grand sustainability challenges associated with water scarcity and climate change. Here, we provide a timely review on the applications of ERMs to electrochemically mediated water treatment (EMWT) and electrochemically mediated carbon capture (EMCC). We first examine the working principles of ERMs-based systems for water treatment and carbon capture, followed by a detailed summary of key figures of merit that quantify the overall performance. Second, we present an in-depth discussion of the multiscale design principles of EMWT and EMCC systems, ranging from materials-level engineering to electrode-level considerations to device configuration optimization. Next, we discuss the development and application of in situ and operando characterization methods, with a particular emphasis on imaging tools, which uncover ubiquitous static and dynamic heterogeneities in ERMs and critically inform rational materials design. Finally, we point out future opportunities and challenges in the emerging field of electrochemically mediated environmental remediation, including developing new tools to monitor complex multiphase transport and reactions, repurposing existing energy nanomaterials for environmental technologies, and scaling and combining EMWT and EMCC systems.
The role of dephasing for dark state coupling in a molecular Tavis–Cummings model
Authors: Davidsson Eric , Kowalewski Markus
Published: July 2023

The collective coupling of an ensemble of molecules to a light field is commonly described by the Tavis–Cummings model. This model includes numerous eigenstates that are optically decoupled from the optically bright polariton states. Accessing these dark states requires breaking the symmetry in the corresponding Hamiltonian. In this paper, we investigate the influence of non-unitary processes on the dark state dynamics in the molecular Tavis–Cummings model. The system is modeled with a Lindblad equation that includes pure dephasing, as it would be caused by weak interactions with an environment, and photon decay. Our simulations show that the rate of pure dephasing, as well as the number of two-level systems, has a significant influence on the dark state population.
A graph neural network-based framework to identify flow phenomena on unstructured meshes
Authors: Wang L. , Fournier Y. , Wald J. F. , Mesri Y.
Published: July 2023

Driven by the abundant data generated from computational fluid dynamics (CFD) simulations, machine learning (ML) methods surpass the deterministic criteria on flow phenomena identification in the way that they are independent of a case-by-case threshold by combining the flow field properties and the topological distribution of the phenomena. The current most popular and successful ML models based on convolutional neural networks are limited to structured meshes and unable to directly digest the data generated from unstructured meshes, which are more widely used in real industrial CFD simulations. We proposed a framework based on graph neural networks with the proposed fast Gaussian mixture model as the convolution kernel and U-Net architecture to detect flow phenomena based on a graph hierarchy generated by the algebraic multigrid method embedded in the open-source CFD solver, code_saturne. We demonstrate the superiority of the proposed kernel and U-Net architecture, along with the generality of the framework to unstructured mesh and unseen case, on detecting the vortices once trained on a single backward-facing step case. Our proposed framework can be trivially extended to detect more flow phenomena in three dimensional cases, which is ongoing work.
Interaction between two overall neutral charged microscopically patterned surfaces
Authors: Zhou Shiqi , Bakhshandeh Amin
Published: July 2023

We study the interaction between heterogeneously charged surfaces in an electrolyte solution by employing classical Density Functional Theory (cDFT) and Monte Carlo simulations. We observe a consistent behavior between cDFT and Monte Carlo simulations regarding force curves and two-dimensional density profiles. Armed with the validated cDFT, we explore the system’s behavior under parameters that are challenging to simulate directly. Our findings include the impacts of domain size, domain charge, domain charge configuration, and bulk electrolyte concentration on the osmotic pressure. Remarkably, the force curve is more sensitive to the domain size for an asymmetric configuration than a symmetry configuration; the bulk concentration weakly influences the force curve independent of the system configurations.
Comparison of multifidelity machine learning models for potential energy surfaces
Authors: Goodlett Stephen M. , Turney Justin M. , Schaefer Henry F.
Published: July 2023

Multifidelity modeling is a technique for fusing the information from two or more datasets into one model. It is particularly advantageous when one dataset contains few accurate results and the other contains many less accurate results. Within the context of modeling potential energy surfaces, the low-fidelity dataset can be made up of a large number of inexpensive energy computations that provide adequate coverage of the N-dimensional space spanned by the molecular internal coordinates. The high-fidelity dataset can provide fewer but more accurate electronic energies for the molecule in question. Here, we compare the performance of several neural network-based approaches to multifidelity modeling. We show that the four methods (dual, Δ-learning, weight transfer, and Meng–Karniadakis neural networks) outperform a traditional implementation of a neural network, given the same amount of training data. We also show that the Δ-learning approach is the most practical and tends to provide the most accurate model.
Experimental detection of the multi-branch hysteresis of the droplet states sitting on a horizontal stretchable substrate
Authors: Dekhtyar Valeria A. , Dubinov Alexander E.
Published: July 2023

In this paper, the states of liquid drops sitting on a horizontal elastic cyclically stretched and then weakened substrate were studied experimentally. A thin rubber band was used as a substrate, and glycerin was used as a liquid. A multi-branch hysteresis of the drop states was detected. The number of branches in the hysteresis can be adjusted by changing the time program for stretching–loosening the substrate tension.
Wave packet theory for non-resonant x-ray emission and non-resonant Auger electron emission in molecules
Authors: Savchenko Viktoriia , Odelius Michael , Banerjee Ambar , Ignatova Nina , Föhlisch Alexander , Gelmukhanov Faris , Kimberg Victor
Published: July 2023

We present a time-dependent theory for non-resonant x-ray emission spectrum (XES) and normal Auger spectrum (NAS) calculation, based on a fully quantum description of nuclear dynamics using the vibrational wave packet concept. We compare two formulations of the time-dependent theory, either employing a two-time propagation scheme or using spectral integration over the electron energy continuum. We find that the latter formulation is more efficient for numerical simulations, providing a reasonable accuracy when the integration step is shorter than the lifetime broadening of the core-ionized state. We demonstrate our approach using the example of non-resonant x-ray emission from a water molecule, considering the lowest core-ionized K−1 and first core-ionized shake-up K−1V−1V1 intermediate states. These channels exemplify the developed theory on bound–bound, bound–continuum, continuum–bound, and continuum–continuum transitions. Our results suggest that the time-dependent approach is efficient for simulating XES involving dissociative states, whereas the time-independent approach, based on Franck–Condon factors, is more efficient for bound–bound transitions expressed as discrete frequency dependence in the energy domain. The methods and discussion have general applicability, including both NAS and more complex systems, such as liquid water.
Micro-adhesive structure inspired by tree frog toe pads fabricated by femtosecond laser processing of PVA sponge
Authors: Shiratori Toshihiro , Sakamoto Jinya , Kanazawa Yuma , Suzuki Masato , Takahashi Tomokazu , Aoyagi Seiji
Published: July 2023

Tree frogs of the species Zhangixalus arboreus are known to generate high adhesive force in wet environments due to the microstructure of their toe pads. Inspired by this toe pads, we fabricated a micro-adhesive structure with hexagonal channels (500, 375, 250, 188, and 125 μm per side) on the surface of a polyvinyl alcohol sponge. Femtosecond laser processing was used to create fine grooves on the surface of the sponge. When the sponge is pressed against the object, the liquid in the sponge is released onto the contact surface. In wet conditions, it is important to maintain the proper thickness of the liquid phase between the microstructure and the object, and this is achieved by the sponge. The characteristics of friction (shear force) between soft and hard objects differ from those between hard materials. When the liquid present on the contact surface is very small, the surface tension of the liquid phase causes the formation of numerous microcapillary bridges, which generate shear forces. The shear force was evaluated by soaking the sponge with water, pressing (300, 400, 500 μm) a flat or uneven surface against the sponge, and then sliding (20, 40 mm/s) the object. The maximum shear force was 0.22 N for the flat surface and 0.34 N for the uneven surface. It was found that the shear force became smaller when the structure became too fine. This phenomenon is due to the agglomeration of the microstructures.
Hugoniot properties of porous stainless steel: Insights from molecular dynamics simulations
Authors: Huy Pham C. , Lorenzana Hector E. , Belof Jonathan L. , Goldman Nir
Published: July 2023

We present a systematic study of Hugoniot properties of porous 316L stainless steel using both a simple interpolation scheme and direct shock simulations in order to probe pore collapse kinetics as well as final thermodynamic states. Both methods indicate that equilibrated Hugoniot properties depend on pore density only and not on the pore distribution or size. We then create a simple porous equation of state model that is shown to be accurate for a range of validation data. This allows us to extend our simulations to make direct comparison to experimental data that have generally significantly larger system sizes and durations. In addition, our direct shock simulations indicate that the relaxation time after hotspot formation is system size dependent and can reach nanosecond timescales for the largest pores investigated in our study, thereby possibly having a measurable effect on fast dynamic loading experiments
Overcoming the singularity of 1D embedment enhances computational efficiency of CNT nanocomposite thermal analysis multifold
Authors: Abaimov Sergey G. , Akmanov Iskander S. , Lomov Stepan V.
Published: July 2023

In the digital era, novel smart materials require digital design with the more increasing demand on computational performance, the smaller scale we approach. Nanocomposites present an ultimate challenge, where the morphology of filler particles and their interactions with polymer have to be addressed. For carbon nanotube (CNT)-like particles, computational efficiency would increase multifold if we were able to replace these complex interactions with an equivalent 1D geometry. Unfortunately, for thermal analysis, it results in a singularity of infinite temperature. In this study, relying on undocumented yet possibilities in Abaqus software, we develop a technique to overcome the singularity and apply it to an aligned-CNT nanocomposite. Digital twin is populated with 3D particle morphology obtained by electron tomography, and numerical simulations demonstrate close reproducibility of experimentally measured values for homogenized thermal conductivity.
Students’ perspectives on a podcast-based assignment exercise, while learning to communicate about infections and vaccines
Authors: Lloyd Charmaine , Apputhurai Pragalathan , Al-Rubaie Ali
Published: July 2023

Podcasts are used in educational institutions to complement learning and revision. In this paper, the incorporation of a student-created podcast component into a group assignment on vaccines was evaluated. It was hypothesised that group podcast preparation would enable health-science undergraduate students to improve their health communication and digital literacy skills. Students (n = 66) were introduced to the assignment early in semester 2 of 2022, after which they attended regular coursework and training on podcasting software. Students had the opportunity to research, plan, script, curate and record their podcasts, actively engaging in a social constructivist learning approach. The audio conversation was recorded in a mock roleplay setting between health experts and laypersons, both played by students. The content comprised scientific aspects, conflicting opinions and contemporary issues on the vaccine topic, in the context of a lay-audience scenario provided in the assignment. The packaged podcast was graded for soundness of content, roleplaying, ability to engage the listener and creativity. Student perspectives and feedback were collected before and after the assignment through short online surveys comprising open-ended and Likert questions. Pairwise analysis showed improved digital literacy, improved confidence in students’ own communication skills and preference for podcast assignments (P < 0.05). Positive comments included the experience of learning about vaccines, use of podcasting software and fun. Though the podcast approach took a longer time to implement, it was an effective means of facilitating group discussion on the topic and offered students a safe space to experiment communication of health and infection topics through podcast technology.
Assessment of stored red blood cells through lab-on-a-chip technologies for precision transfusion medicine
Authors: Isiksacan Ziya , D’Alessandro Angelo , Wolf Susan M. , McKenna David H. , Tessier Shannon N. , Kucukal Erdem , Gokaltun A. Aslihan , William Nishaka , Sandlin Rebecca D. , Bischof John , Mohandas Narla , Busch Michael P. , Elbuken Caglar , Gurkan Umut A. , Toner Mehmet , Acker Jason P. , Yarmush Martin L. , Usta O. Berk
Published: July 2023

Transfusion of red blood cells (RBCs) is one of the most valuable and widespread treatments in modern medicine. Lifesaving RBC transfusions are facilitated by the cold storage of RBC units in blood banks worldwide. Currently, RBC storage and subsequent transfusion practices are performed using simplistic workflows. More specifically, most blood banks follow the “first-in-first-out” principle to avoid wastage, whereas most healthcare providers prefer the “last-in-first-out” approach simply favoring chronologically younger RBCs. Neither approach addresses recent advances through -omics showing that stored RBC quality is highly variable depending on donor-, time-, and processing-specific factors. Thus, it is time to rethink our workflows in transfusion medicine taking advantage of novel technologies to perform RBC quality assessment. We imagine a future where lab-on-a-chip technologies utilize novel predictive markers of RBC quality identified by -omics and machine learning to usher in a new era of safer and precise transfusion medicine.
AcrIIC4 inhibits type II-C Cas9 by preventing R-loop formation
Authors: Sun Wei , Cheng Zhi , Wang Jiuyu , Yang Jing , Li Xueyan , Wang Jinlong , Chen Minxuan , Yang Xiaoqi , Sheng Gang , Lou Jizhong , Wang Yanli
Published: July 2023

Anti-CRISPR (Acr) proteins are encoded by phages and other mobile genetic elements and inhibit host CRISPR-Cas immunity using versatile strategies. AcrIIC4 is a broad-spectrum Acr that inhibits the type II-C CRISPR-Cas9 system in several species by an unknown mechanism. Here, we determined a series of structures of
Haemophilus parainfluenzae
Cas9 (HpaCas9)-sgRNA in complex with AcrIIC4 and/or target DNA, as well as the crystal structure of AcrIIC4 alone. We found that AcrIIC4 resides in the crevice between the REC1 and REC2 domains of HpaCas9, where its extensive interactions restrict the mobility of the REC2 domain and prevent the unwinding of target double-stranded (ds) DNA at the PAM-distal end. Therefore, the full-length guide RNA:target DNA heteroduplex fails to form in the presence of AcrIIC4, preventing Cas9 nuclease activation. Altogether, our structural and biochemical studies illuminate a unique Acr mechanism that allows DNA binding to the Cas9 effector complex but blocks its cleavage by preventing R-loop formation, a key step supporting DNA cleavage by Cas9.
Materials for teaching the rotational motion of magnetically levitating bodies with a video camera
Authors: Nishiwaki Yoichi , Takashige Masaaki
Published: July 2023

This study reports analysis of the rotational motion of magnetically levitated superconducting and diamagnetic bodies using video cameras for physics education. The analysis was possible without using special equipment such as a high-speed camera. In this case, the angular velocities of the superconducting and diamagnetic bodies showed linear and exponential decay with time, respectively. Such results can be used as an introduction to solid state physics and as a teaching material for elementary mechanics.
The effect of tool wear on the damaged layer thickness and tool wear rate in ultra-precision turning of quartz glass
Authors: Liu Yujie , Tong Hao , Li Yong , Chen Jialong
Published: July 2023

Quartz glasses have been extensively used for many fields, such as semiconductor technology, optical instruments, inertial navigation and others. Ultra-precision turning with diamond tools can achieve high surface accuracy when processing non-ferrous materials. In recent years, ultra-precision turning has also been tried to be applied to process brittle materials, but there are constraints including small removal amount and tool wear. When diamond tools are used to cut quartz glass, tool wear occurs under the combined action of thermal effect and mechanical friction, which will affect the damaged layer thickness of the processed quartz glass. In this paper, the tool wear factor is led into the calculation of the extrusion volume, and the damaged layer thickness is calculated by the extrusion volume. Combined with the results of quartz glass turning experiments and the calculated results by simulation, the effect of tool wear factor on the damaged layer thickness and the tool wear rate is analyzed. The analysis shows that tool wear will lead to chip fracture thickness decrease and extrusion volume increase. Combined action of these two aspects, the damage layer thickness keeps unchanged at first and then rises with the increase of tool wear. In addition, the experimental results show that the tool wear rate rises with the increase of tool wear.
Atomically precise gold nanoclusters for CO oxidation: balancing activity and stability by ligand shedding
Authors: Pei Wei , She Jie , Yu Xueke , Zhou Si , Zhao Jijun
Published: July 2023

Ligand-protected gold (Au) nanoclusters (NCs) are fascinating for catalytic applications due to their unique electronic structure and catalytic activity endowed by quantum size effects. The identification of the number of ligands in NCs not only determines the catalytic behavior of their active sites, but also directly affects their stability. Therefore, establishing a physical picture including the number of ligands on the surface of NCs, geometric structure, thermodynamic stability and catalytic activity is crucial for balancing stability and catalytic performance. Combined with density functional theory calculations, the catalytic behavior of phosphine ligand-protected Au NCs (including [Au9(PPh3)8]3+, [Au10(PPhCy2)6Cl3]+, [Au11(PPh3)8Cl2]+ and [Au13(PMe2Ph)10Cl2]3+) with ligand shedding processes were systematically investigated using gas-phase CO oxidation as a probe reaction. The results show that the geometric configurations of these Au NCs evolve towards a planar structure with the shedding of ligands. Their chemical activity shows a distinct linear relationship with their d orbital centers, which are governed by the electron coupling between the surface ligands and the Au core for each ligand of Au NCs. The geometrical structure–chemical activity relationship was uncovered for these ligand Au NCs. These results provide important knowledge for precisely regulating the activity and stability of ligand-protected metal NCs for energy conversion at the atomic level.
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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.