bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance evaluation of a 3D split-and-recombination micromixer with asymmetric structures
Authors: Jiao Dezhao , Zhang Ruirong , Zhang Hantian , Ren Shuang , Feng Huicheng , Chang Honglong 
Published: June 2022

Abstract
Micromixers are widely used in lab-on-a-chip devices for analytical chemistry, bioengineering, and biomedicine to achieve rapid mixing and analysis of samples. However, the existing micromixers are mostly two-dimensional structures with low mixing efficiency. Even three-dimensional (3D) micromixers with complex structures have low mixing efficiency in the low Reynolds number range. In this paper, a 3D split-and-recombination (SAR) micromixer inspired by the horseshoe transform principle is proposed to further improve the mixing efficiency. There 3D SAR micromixers with different subchannel sizes were designed and tested in the Reynolds numbers range of 0.1–100. The optimal size of the micromixer was revealed through computational fluid dynamics simulations and experimental test results. A minimum mixing index of 91% is achieved in the range of Reynolds numbers from 0.1 to 100. Especially, for Re ⩾ 20, the mixing index is higher than 99%. The results obtained indicate that this 3D SAR micromixer with an asymmetric structure shows a satisfactory choice in the fluid mixing process of microfluidic systems, and has a potential application in the field of microchip-based biochemical analysis.
Design and investigation of dielectric modulated triple metal gate-oxide-stack Z-shaped gate horizontal pocket TFET device as a label-free biosensor
Authors: Reddy Nelaturi Nagendra , Panda Deepak Kumar 
Published: June 2022

Abstract
In this article, a dielectric modulated triple metal gate-oxide-stack Z-shaped gate horizontal source pocket tunnel field-effect transistor (DM-TMGOS-ZHP-TFET) structure has been investigated for the application of label free-biosensor. This work explores the advantage of gate work function engineering along with the gate-oxide-stack approach for the ZHP-TFET for the first time. An asymmetric nano-cavity is created adjacent to the source-channel junction to immobilize the target biomolecules conjugation to the proposed device. The sensitivity of the device is thoroughly investigated in terms of average subthreshold swing (SS), threshold voltage (V
th) and the switching ratio (I
on/I
off) of the proposed device with the variation of the dielectric constant value inside the nano-gap under the gate electrode. The device characteristics are investigated with different combinations of metal work functions to match the desired feature and sensitivity of the device. In addition, the sensitivity analysis of the proposed device is analyzed in the presence of both positive and negative charged biomolecules in the cavity region to study the charge effect on label-free detection of the device. A comparative study is conducted between a single metal gate (SMG) ZHP-DM-TFET biosensor with the DM-TMGOS-ZHP-TFET biosensor explores the advantage of gate-work function engineering with a gate-oxide-stack approach. Interestingly the DM-TMGOS-ZHP-TFET biosensor shows superior results with a high current ratio sensitivity of 103 which is ten times more than the SMG-ZHP-DM-TFET biosensor and this device also exhibits low subthreshold characteristics.
Stimulated Raman adiabatic passage in a quantum system near a plasmonic nanoparticle
Authors: Domenikou Natalia , Thanopulos Ioannis , Stefanatos Dionisis , Yannopapas Vassilios , Paspalakis Emmanuel 
Published: June 2022

Abstract
We investigate theoretically the population transfer process in a Λ-type three-level quantum system (QS) near a metallic nanosphere using the stimulated Raman adiabatic passage (STIRAP) technique. We combine density matrix quantum dynamical calculations with first-principle electromagnetic calculations, which quantify the influence of the plasmonic nanoparticle on the electric field of the pump and Stokes pulses in STIRAP as well as on the spontaneous emission rates within the Λ-type system. We study the population transfer process by varying the free-space spontaneous emission rate, the distance of the QS from the nanosphere, the polarization direction with respect to the nanoparticle surface and the relative strength of the pump and Stokes pulses used in STIRAP. We find that when the pump and Stokes fields have tangential and radial polarizations with respect to the nanosphere surface, the transfer efficiency is improved due to the increase of the decay rate of the excited state to the target state relatively to the decay to the initial state. The optimal population transfer is achieved for small interparticle distances, moderate free space spontaneous decay rate, large values of the pump Rabi frequency and small values of the Stokes Rabi frequency. When we exchange the polarization directions of the pump and Stokes fields we can still find a range of parameters where the population transfer remains efficient, but larger Stokes Rabi frequencies are necessary to overcome the increased decay rate from the excited state back to the initial state.
Observing capture with a colloidal model membrane channel
Authors: Knowles Stuart F , Fletcher Marcus , Mc Hugh Jeffrey , Earle Max , Keyser Ulrich F , Thorneywork Alice L 
Published: June 2022

Abstract
We use video microscopy to study the full capture process for colloidal particles transported through microfluidic channels by a pressure-driven flow. In particular, we obtain trajectories for particles as they move from the bulk into confinement, using these to map in detail the spatial velocity and concentration fields for a range of different flow velocities. Importantly, by changing the height profiles of our microfluidic devices, we consider systems for which flow profiles in the channel are the same, but flow fields in the reservoir differ with respect to the quasi-2D monolayer of particles. We find that velocity fields and profiles show qualitative agreement with numerical computations of pressure-driven fluid flow through the systems in the absence of particles, implying that in the regimes studied here particle-particle interactions do not strongly perturb the flow. Analysis of the particle flux through the channel indicates that changing the reservoir geometry leads to a change between long-range attraction of the particles to the pore and diffusion-to-capture-like behaviour, with concentration fields that show qualitative changes based on device geometry. Our results not only provide insight into design considerations for microfluidic devices, but also a foundation for experimental elucidation of the concept of a capture radius. This long standing problem plays a key role in transport models for biological channels and nanopore sensors.
Protonation enhanced superconductivity in PdTe2
Authors: Liu Zhen , Han Tao , Liu Mengqin , Huang Shuting , Zhang Zongyuan , Long Mingsheng , Hou Xingyuan , Shan Lei 
Published: June 2022

Abstract
Electrochemical ionic liquid gating is an effective way to intercalate ions into layered materials and modulate the properties. Here we report an enhanced superconductivity in a topological superconductor candidate PdTe2 through electrochemical gating procedure. The superconducting transition temperature was increased to approximately 3.2 K by ionic gating induced protonation at room temperature. Moreover, a further enhanced superconductivity of both superconducting transition temperature and superconducting volume fraction was observed after the gated samples were placed in a glove box for 2 months. This may be caused by the diffusion of protons in the gated single crystals, which is rarely reported in electrochemical ionic liquid gating experiments. Our results further the superconducting study of PdTe2 and may reveal a common phenomenon in the electrochemical gating procedure.
Magnetic APFC modeling and the influence of magneto-structural interactions on grain shrinkage
Authors: Backofen Rainer , Salvalaglio Marco , Voigt Axel 
Published: June 2022

Abstract
We derive the amplitude expansion for a phase-field-crystal (APFC) model that captures the basic physics of magneto-structural interactions. The symmetry breaking due to magnetization is demonstrated, and the characterization of the magnetic anisotropy for a bcc crystal is provided. This model enables a convenient coarse-grained description of crystalline structures, in particular when considering the features of the APFC model combined with numerical methods featuring inhomogeneous spatial resolution. This is shown by addressing the shrinkage of a spherical grain within a matrix, chosen as a prototypical system to demonstrate the influence of different magnetizations. These simulations serve as a proof of concept for the modeling of manipulation of dislocation networks and microstructures in ferromagnetic materials within the APFC model.
Development and didactic analysis of smartphone-based experimental exercises for the smart physics lab
Authors: Kaps A , Stallmach F 
Published: June 2022

Abstract
Smartphone-based experimental exercises were incorporated as part of the homework problems in an introductory mechanics course at a university. A quasi-experimental field study with two cohorts design was performed to measure the impact of such exercises on motivation, interest and conceptual understanding. The empirical results on learning achievement show a significant positive influence of the smartphone-based experimental exercise for the dynamics of rigid bodies topic with a medium effect size of d = 0.42. For the analysis of rotational motion topic, a positive learning achievement for both groups was evidenced, but the effect size of the smartphone-based exercise was rather small at d = 0.20 . The intrinsic and germane cognitive loads turned out to be similar at an intermediate level for both groups. However, the extrinsic cognitive load for the intervention group decreased significantly, which might be the reason why more complex experimental exercises foster conceptual understanding.
Learning about rockets, in stages
Authors: Blanco Philip R 
Published: June 2022

Abstract
A rocket must carry the fuel it expels in order to accelerate its structure and payload. The rocket equation relates the change in speed to the fuel mass expelled. To launch a spacecraft into Earth orbit requires a multi-stage rocket, since otherwise the mass of fuel required would be prohibitive. While the details vary among historical and current launch vehicles, the advantages and physical principles of staging can be demonstrated by analysing the simpler case of a two-stage rocket in free space. I show that a two-stage rocket produces a higher payload speed than a single-stage rocket with the same fuel and structural mass, and introduce the concept of optimal staging to maximise this speed. I also examine how mechanical energy extracted from the expelled fuel is distributed between the stages, payload capsule, and exhaust. A surprising result is that the two-stage rocket deposits more energy into the exhaust stream than its single-stage counterpart. I suggest further investigations that are appropriate for advanced high school or undergraduate students of physics or aerospace engineering. Supplementary materials are provided online for classroom use.
From atoms to stars: an interactive theatre play based on ‘The Little Prince’ novella to describe spatial thinking
Authors: Acuña-Umaña K , Gómez-Quirós C , Herrera-Sancho O A 
Published: June 2022

Abstract
The implementation of theatre as a didactic tool for teaching science provides a new perspective on the importance of interdisciplinary approaches in the construction of meaningful learning experiences. Gamification and collaborative work are functional strategies to teach scientific concepts in a creative way. However, there are still conceptual issues about spatial thinking that are difficult for students to understand owing to the lack of visualization of objects and their development through a characteristic chronicle. Here we show an innovative way to unifying science, technology, engineering, arts and mathematics (STEAM) careers through the development of an interactive theatrical play inspired by The Little Prince novella, to promote a culture of integration of science, theatre and literature. One of the more significant findings to emerge from this study is that the didactic strategies used are key ingredients in order to design an unique theatre play based on a link between history of atomic models and literature towards full understanding of spatial macroscales and microscales thinking. Due to the successful in the qualitative assessment results, we are devising to continue exploring the use of these didactic strategies to achieve an integrated and greater impact on students’ learning processes.
Video analysis of one-dimensional motion and collision for distance learning laboratory
Authors: Eadkhong Thammarong , Sirisathitkul Chitnarong , Danworaphong Sorasak 
Published: June 2022

Abstract
Video analysis is carried out for one-dimensional motion and collision experiments using Tracker. Physical variables, i.e. displacement, time, and velocity, can be deducted from the analysis and allows one to connect them to the equation of motion and energy conservation. Corresponding equations of motions are given without neglecting the effect of friction and air resistance. Their solutions are used as models for data-fitting purposes. The fitting results allow one to find the surface friction coefficient and the air resistance parameter for the first experiment and friction for the second experiment. These experiments and analyses can be implemented for at least sophomore-level physics in a university. However, if simplified by removing all resistant parts, they can be used for high-school or first-year students in a university. The video files can be distributed to students for online courses that are prevalently ongoing worldwide due to the COVID pandemic. Students can observe the experiments and analyse data at home. With scheduled online consulting sessions, students can conduct the analysis with helps from instructors.
From skating rink to physics assignment—viewing a photo from a mechanics perspective
Authors: Malmqvist Karin , Pendrill Ann-Marie 
Published: June 2022

Abstract
Circular motion changes the perception of up and down. For a skater, the need to lean in towards the centre of an arc constitutes an embodiment of centripetal acceleration. This paper presents a discussion between a physicist and a high-school science teacher without previous physics studies at university level. The discussions started as part of a course assignment and focused on a photo of skaters practicing a ‘wing’, which is a move in synchronised skating. The skating experiences are integrated with an understanding of the relations between radius, acceleration and the angles the total force from the ice deviates from the vertical.
A deeper look at entropy change in the free expansion of an ideal gas
Authors: Reed B Cameron 
Published: June 2022

Abstract
The increase in entropy during the volume-doubling free expansion of an ideal gas is a staple example of thermodynamics classes. While the result,

Δ
S
=
(
n
R
)
ln
2

, is correct, the common textbook argument which leads to it can be potentially confusing. An improved but still very simple replacement model is described here and the difficulty in the common argument is discussed.
Role of excimer formation and induced photoemission on the Ar metastable kinetics in atmospheric pressure Ar–NH3 dielectric barrier discharges
Authors: Robert Raphaël , Hagelaar Gerjan , Sadeghi Nader , Magnan Romain , Stafford Luc , Massines Françoise 
Published: June 2022

Abstract
Tunable diode laser absorption spectroscopy was used to record the space-and time-resolved number density of argon metastable atoms, Ar(1s3) (Paschen notation), in plane-to-plane dielectric barrier discharges (DBDs) operated in a Penning Ar–NH3 mixture at atmospheric pressure. In both low-frequency (LF 650 V, 50 kHz) discharges and dual LF–radiofrequency (RF 190 V, 5 MHz) discharges operated in α–γ mode, the density of Ar(1s3) revealed a single peak per half-period of the LF voltage, with rise and decay times in the sub-microsecond time scale. These results were compared to the predictions of a 1D fluid model based on continuity and momentum equations for electrons, argon ions (Ar+ and Ar2
+) and excited argon 1s atoms as well electron energy balance equation. Using the scheme commonly reported for Ar-based DBDs in the homogeneous regime, the Ar metastable kinetics exhibited much slower rise and decay times than the ones seen in the experiments. The model was improved by considering the fast creation of Ar2
* excimers through three-body reactions involving Ar(1s) atoms and the rapid loss of Ar2
* by vacuum ultraviolet light emission. In optically thin media for such photons, they can readily reach the dielectric barriers of the DBD electrodes and induce secondary electron emission. It is shown that Ar2
* and photoemission play a significant role not only on the Ar metastable kinetics, but also on the dominant ionization pathways and possible α–γ transition in dual frequency RF–LF discharges.
Modeling of high power impulse magnetron sputtering discharges with tungsten target
Authors: Babu Swetha Suresh , Rudolph Martin , Lundin Daniel , Shimizu Tetsuhide , Fischer Joel , Raadu Michael A , Brenning Nils , Gudmundsson Jon Tomas 
Published: June 2022

Abstract
The ionization region model (IRM) is applied to model a high power impulse magnetron sputtering discharge with a tungsten target. The IRM gives the temporal variation of the various species and the average electron energy, as well as internal discharge parameters such as the ionization probability and the back-attraction probability of the sputtered species. It is shown that an initial peak in the discharge current is due to argon ions bombarding the cathode target. After the initial peak, the W+ ions become the dominating ions and remain as such to the end of the pulse. We demonstrate how the contribution of the W+ ions to the total discharge current at the target surface increases with increased discharge voltage for peak discharge current densities J
D,peak in the range 0.33–0.73 A cm−2. For the sputtered tungsten the ionization probability increases, while the back-attraction probability decreases with increasing discharge voltage. Furthermore, we discuss the findings in terms of the generalized recycling model and compare to experimentally determined deposition rates and find good agreement.
All-HKMG-bounded SCR for advanced ESD protection in 14 nm FinFET technology
Authors: Du Feibo , Xie Tiantian , Wang Jun , Chang Kuan-Chang , Lin Xinnan , Hou Fei , Chen Ruibo , Han Aoran , Liu Zhiwei 
Published: June 2022

Abstract
In this paper, a novel all-high-K metal gate (HKMG)-bounded silicon-controlled rectifier (AHBSCR) is proposed for advanced electrostatic discharge (ESD) protection in FinFET processes. Depart from its prior arts, in AHBSCR, both the main SCR path and the triggering diode path are placed along the Fin direction, and all active areas are bounded by HKMG, thus expressing superior conduction capability under various ESD stresses and a more compact silicon footprint. Experimental results show that the proposed AHBSCR owns a suitable snapback window of 1.1 V–1.6 V, a fast turn-on speed of only 400 ps, an extreme low leakage current of less than 100 pA@-1 V as well as a figure of merit of 24.3 mA fF−1, indicating it is competent to replace the conventional FinFET diodes in rail-based ESD network to further improve the efficiency of ESD protection.
Fabrication of sheet-like ZnO/ZnS heterostructures with enhanced H2S sensing performance at low operation temperatures
Authors: Wu Xinwen , Zhao Zhen , Zhang Lei , Jiao Wanli 
Published: June 2022

Abstract
A sheet-like ZnO/ZnS-based sensor with a sensitive response and excellent selectivity to H2S at low operation temperatures was prepared using a hydrothermal method combined with a sulfuration process. Meanwhile, x-ray diffraction, x-ray spectroscopy, scanning electron microscopy, and transmission electron microscopy measures were carried out to characterize the crystallographic information, elemental distribution, and microstructure of the sheet-like ZnO/ZnS. Results of the gas-sensing tests show that the response value of ZnO/ZnS-6 to 10 ppm of H2S reaches 90 at 100 °C, and the effective detection limit is as low as 1 ppm. The enhanced gas-sensing performance is attributed to the sheet-like microstructure and the formation of ZnO/ZnS heterojunctions. To H2S, the prepared ZnO/ZnS sensor shows satisfactory sensitivity, selectivity, and stability, and the lower heating temperature augurs wider potential applications.
Adaptive genetic algorithm enabled tailoring of piezoelectric metamaterials for optimal vibration attenuation
Authors: Jian Yupei , Tang Lihua , Hu Guobiao , Wang Yuesheng , Aw Kean C 
Published: June 2022

Abstract
Piezoelectric metamaterials with shunt resonant circuits have been extensively investigated for their tunability in bandgaps. However, the vibration attenuation ability induced by the electromechanical coupling is generally weaker than that of mechanical metamaterials, limiting their applications in engineering practice. This research presents a non-uniform piezoelectric metamaterial beam with shunt circuit parameters optimized by an adaptive genetic algorithm (AGA) for tailoring the vibration attenuation zone. First, the non-uniform piezoelectric metamaterial beam is modeled for transmittance analysis and verified by the finite element method. By simultaneously tuning the resonance frequencies and the resistance of the shunt circuits, it is conceptually demonstrated that the attenuation zone can be broadened, and the undesired localized vibration modes can be mitigated. Subsequently, two optimization strategies are proposed respectively for two typical vibration scenarios. The inductances and the load resistance in the shunt circuits constitute the set of design variables and are optimized by the AGA. Dedicated case studies are carried out, and the results show that the objective-oriented circuitry parameters can greatly enrich the design freedom, and tailor the transmittance profile according to a given vibration spectra. As compared to the conventional uniform and the graded piezoelectric metamaterial beams, the proposed design provides superior vibration attenuation performance and demonstrates a promising approach for tailoring piezoelectric metamaterials systems.
Tunable hyperbolic out-of-plane deformation of 3D-printed auxetic PLA shape memory arrays
Authors: Li Zhenghong , Liu Yuheng , Lu Haibao , Shu Dong-Wei 
Published: June 2022

Abstract
Auxetic metamaterials attract wide attention due to their unusual mechanical behaviours. This work explores the tunability of the bidirectionally hyperbolic deformation of thin plates under uniaxial compression, instead of the Euler buckling deformation. Inspired by the horseshoe structures, through tuning the radius and thickness of the central circles of the horseshoes, as well as the thickness and subtending arc angles of the four branches, bidirectionally hyperbolic out of plane deformation was achieved together with auxetic behaviour. Finally, finite element simulations, theoretical analyses, and experimental verifications have been carried out to design the out of plane bidirectionally hyperbolic deformation by the tailorable temperature sensitivity and shape memory effect in unit cells.