bluuebunny/crossref_metadata_2025 huggingface dataset:
Polarized Coulomb field scattering in LaAlO3/SrTiO3 heterojunction field-effect transistors
Authors: Fan Baocai , Liu Yichen , Fu Chen , Lin Zhaojun , Li Sean
Published: January 2024

LaAlO3/SrTiO3 heterojunction field-effect transistors (HFETs) were fabricated. Using a combination of measured current–voltage (I–V) output curves and gate-source capacitance–voltage (C–V) characteristic curves for the fabricated LaAlO3/SrTiO3 HFETs, and considering scattering mechanisms for longitudinal optical phonon, interface rough, electron-electron (E-E), acoustic phonon, and polarized Coulomb field (PCF), the channel electron mobility of LaAlO3/SrTiO3 HFETs has been calculated and analyzed. The results showed that PCF scattering is a significant carrier scattering mechanism in LaAlO3/SrTiO3 HFETs. The heterostructure of the LaAlO3/SrTiO3 system has strong polarization characteristics. This paper is the first to demonstrate that PCF scattering is a significant carrier scattering mechanism in LaAlO3/SrTiO3 HFETs, following GaN HFETs, thus demonstrating that LaAlO3/SrTiO3 HFETs also have PCF scattering effect.
Numerical study of the evolution of unsteady cavitation flow around hydrofoils with leading-edge tubercles
Authors: Fan Menghao , Sun Zhaocheng , Yu Ran , Li Zengliang
Published: January 2024

Humpback leading-edge (LE) tubercles are applied to the cavitation control of hydrofoils, and the effect of LE tubercles on hydrofoil cavitation characteristics under different cavitation numbers (σ) is discussed. The results show that LE tubercles can promote hydrofoil initial cavitation, with cavitation appearing first in the groove. This is because the separation effect of LE tubercles induces flow from peak to trough, resulting in an accelerated flow rate and a local low-pressure area. The quasiperiodic properties of the cloud-cavitation stage are not improved, but LE tubercles considerably reduced hydrofoil cavitation, resulting in a cavitation volume reduction of roughly 16.5%–20.4% and maximum cavitation volume reduction of roughly 10.5%–21.8%. The flow field at the tubercle was analyzed, and it was found that vortex cavitation was induced by the spiral vortex. The pressure pulsation on the hydrofoil is highly related to the cavitating evolution. The dominant frequency of the pressure pulsation increases with the decrease of σ and is not affected by the LE tubercles. Finally, LE tubercles are observed to facilitate the transformation of laminar flow to turbulent flow, hence increasing wake disturbance and facilitating the disintegration of the wake vortex structure.
Stabilize cloud cavitation with an obstacle near hydrofoil's trailing edge and conduct local entropy production analysis
Authors: Wang Lu , Liu Jintao , Li Wen , Wang Pengzhong , Huang Bin , Wu Dazhuan
Published: January 2024

Cloud cavitation always causes severe damage to the efficiency and stability of the hydraulic machinery, resulting in extra energy losses in the system. We have observed an effective and simple way to prevent cloud cavitation formation by placing an obstacle near the hydrofoil's trailing edge. Cavitating flows around four different types of hydrofoils were simulated using the stress-blended eddy simulation turbulence model: the National Advisory Committee for Aeronautics (NACA) 66 hydrofoil and the NACA 66 hydrofoil with a 1 ×1 mm2 obstacle at 0.3c, 0.5c, or 0.7c. Sheet cavitation is the predominant mode of cavity flow when the obstruction is positioned at 0.7c. To find out why the cloud cavitation growth can be stopped when the obstruction is positioned at 0.7c, the velocity field, vorticity in the Z direction, and vortex structure of the Q-criterion were computed. To study the energy loss of the cavity flow and comprehend how obstacles affect it, the local entropy production rate was computed. It was discovered that the vorticity downstream of the obstacle, positioned at 0.7c, is restructured, which helps manage the flow separation upstream of the obstacle. Consequently, the hydrofoil's suction surface vorticity nearly rotates in the same direction as the obstacle at 0.7c, and the direction of Vx upstream of the obstacle is in the positive direction of the X axis, indicating that the reentrant flow has been controlled upstream of the 0.7c obstacle. Furthermore, cavitation shedding and the entropy production rate are strongly correlated, and regulating cloud cavitation growth is advantageous for energy conservation.
Optimization algorithm to generate a robust magnetic force of the magnetic navigation system against position error of a magnetic robot
Authors: Lee D. , Kwon J. , Jang G.
Published: January 2024

We propose an optimization algorithm to generate a robust magnetic force against position error to achieve good controllability of the magnetic robot in the region of interest of a magnetic navigation system comprising electromagnets. We formulate an optimization problem that minimizes the norm of the spatial derivatives of the magnetic force subject to the constraints of the magnetic flux density and magnetic force. The robust magnetic force generated by the proposed algorithm was compared with conventional pseudo-inverse matrix method and verified through an experiment in which a magnetic robot was successfully steered along a bifurcated glass tube to reach a target position.
Magnetic properties of microwave-processed ferromagnetic La2CoMnO6
Authors: Manikandan M. , Mahendiran R.
Published: January 2024

We synthesized ferromagnetic La2CoMnO6 by irradiating a stoichiometric mixture of oxide powder with microwave (MW) of frequency 2.45 GHz and studied the impact of microwave power (P) on its structural and magnetic properties. The MW power (P) was varied from 1000 to 1600 W at a pre-set sintering temperature of 1200 °C and a dwelling time of 20 min. The ferromagnetic transition temperature and saturation magnetization depend on P. The highest saturation magnetization value of 5.54 μB/f.u. was realized in the sample irradiated with P = 1400 W which is closer to the theoretical value of 6 μB/f.u. for spin-only contributions from Co2+ (S = 3/2) and Mn4+ (S = 3/2). The observed results can be attributed to varying degrees of B-site ordering of Co2+ and Mn4+ ion with the MW power, however, caution has to be taken to ensure that the sample is maintained at a specified temperature for the desired dwelling time. Our results indicate that varying the microwave power at a fixed sintering temperature provides a different approach for manipulating saturation magnetization and Curie temperature.
Determination of thermal conductivity, thermal diffusivity, and specific heat of liquids using a thermoelectric module
Authors: Mendiola-Curto Víctor , Beltrán-Pitarch Braulio , García-Cañadas Jorge
Published: January 2024

Managing heat through working fluids is essential in many applications, as well as the development of new fluids with improved properties. Therefore, the characterization of their thermal properties, which is usually a laborious task, is necessary to design and model new thermal systems. In this study, we show the proof of concept of a new method capable of determining the thermal conductivity, thermal diffusivity, and specific heat capacity of liquids from a single simple measurement, provided their density is known (a property easy to measure). The method is based on the use of a thermoelectric module, which is soldered to a large copper block at one side (heat sink). At the other side, the liquid is added on top of the ceramic external layer of the module. By means of impedance spectroscopy measurements, it is demonstrated for three liquids (water, Luzar, and diethylene glycol) that their thermal properties of can be obtained. In order to do this, a new equivalent circuit was developed to account for the new boundary conditions of the measuring setup. Random and systematic errors were calculated and combined to obtain a total uncertainty <8.6% for the thermal conductivity, <6.3% for the thermal diffusivity, and <6.1% for the specific heat capacity. The reasonably low uncertainties obtained position the new method as a low-cost alternative able to provide the three key thermal properties of liquids from one single measurement and only using a single setup.
Hilbert’s and Takeda’s single-shot interferometry with a linear-carrier: a comparison
Authors: Ferrari José A , Flores Jorge L , Fernández Lakatos Matías , Ayubi Gastón A , Perciante César D , Frins Erna
Published: January 2024

The purpose of the present work is to compare single-shot phase-retrieval methods based on Hilbert’s transform with Takeda’s spatial linear-carrier method. In addition, we briefly discuss the so-called slightly-off-axis method that involves two interferograms as an efficient way to remove background illumination bias. After carefully analyzing the assumptions implicit in both approaches, we demonstrate that the Hilbert transform based method is completely identical to the 30 years old Takeda’s interferometry with a spatial linear-carrier. Validation experiments are presented.
Unraveling the strain tuning mechanism of interlayer excitons in WSe2/MoSe2 heterostructure
Authors: Ge Anping , Ge Xun , Sun Liaoxin , Lu Xinle , Ma Lei , Zhao Xinchao , Yao Bimu , Zhang Xin , Zhang Tao , Jing Wenji , Zhou Xiaohao , Shen Xuechu , Lu Wei
Published: January 2024

Atomically thin transition metal dichalcogenides (TMDs) exhibit rich excitonic physics, due to reduced dielectric screening and strong Coulomb interactions. Especially, some attractive topics in modern condensed matter physics, such as correlated insulator, superconductivity, topological excitons bands, are recently reported in stacking two monolayer (ML) TMDs. Here, we clearly reveal the tuning mechanism of tensile strain on interlayer excitons (IEXs) and intralayer excitons (IAXs) in WSe2/MoSe2 heterostructure (HS) at low temperature. We utilize the cryogenic tensile strain platform to stretch the HS, and measure by micro-photoluminescence (μ-PL). The PL peaks redshifts of IEXs and IAXs in WSe2/MoSe2 HS under tensile strain are well observed. The first-principles calculations by using density functional theory reveals the PL peaks redshifts of IEXs and IAXs origin from bandgap shrinkage. The calculation results also show the Mo-4d states dominating conduction band minimum shifts of the ML MoSe2 plays a dominant role in the redshifts of IEXs. This work provides new insights into understanding the tuning mechanism of tensile strain on IEXs and IAXs in two-dimensional (2D) HS, and paves a way to the development of flexible optoelectronic devices based on 2D materials.
How does the electric field induced by tDCS influence motor-related connectivity? Model-guided perspectives
Authors: Fernandes Sofia Rita , Callejón-Leblic M Amparo , Ferreira Hugo Alexandre
Published: January 2024

Over the last decade, transcranial direct current stimulation (tDCS) has been applied not only to modulate local cortical activation, but also to address communication between functionally-related brain areas. Stimulation protocols based on simple two-electrode placements are being replaced by multi-electrode montages to target intra- and inter-hemispheric neural networks using multichannel/high definition paradigms. Objective. This study aims to investigate the characteristics of electric field (EF) patterns originated by tDCS experiments addressing changes in functional brain connectivity. Methods. A previous selection of tDCS experimental studies aiming to modulate motor-related connectivity in health and disease was conducted. Simulations of the EF induced in the cortex were then performed for each protocol selected. The EF magnitude and orientation are determined and analysed in motor-related cortical regions for five different head models to account for inter-subject variability. Functional connectivity outcomes obtained are qualitatively analysed at the light of the simulated EF and protocol characteristics, such as electrode position, number and stimulation dosing. Main findings. The EF magnitude and orientation predicted by computational models can be related with the ability of tDCS to modulate brain functional connectivity. Regional differences in EF distributions across subjects can inform electrode placements more susceptible to inter-subject variability in terms of brain connectivity-related outcomes. Significance. Neuronal facilitation/inhibition induced by tDCS fields may indirectly influence intra and inter-hemispheric connectivity by modulating neural components of motor-related networks. Optimization of tDCS using computational models is essential for adequate dosing delivery in specific networks related to clinically relevant connectivity outcomes.
Experimental validation of absorbed dose-to-medium calculation algorithms in heterogeneous media
Authors: Delbaere Alexia , Younes Tony , Khamphan Catherine , Vieillevigne Laure
Published: January 2024

Objective. The aim of this work was to determine heterogeneous correction factors

h

Q
clin

,

Q
ref

f
clin

,

f
ref

det

m
,
w

to validate absorbed dose-to-medium

D

m
,

Q
clin

m
,

f
clin

calculation algorithms from detector readings. The impact of detector orientation perpendicular and parallel to the beam central axis on the correction factors was also investigated. Approach. The

h

Q
clin

,

Q
ref

f
clin

,

f
ref

det

m
,
w

factors were calculated for four types of detectors (PTW PinPoint T31016, PTW microDiamond T60019, PTW microSilicon T60023 and EBT3 film) placed in different media (cortical bone, lung, adipose tissue, Teflon and RW3) for the 6 MV energy beam with a 10 × 10 cm2 field size. These corrections were then applied to the detector measurements performed at different depths in heterogeneous phantoms. Main results. The

h

Q

clin

,

Q

ref

f

clin

,

f

ref

det

m
,
w

factors mainly depended on the media and slightly on the type of detector. Considering all detectors, the largest corrections were found in high-density media with values ranging from 0.911 to 0.934 in cortical bone. For comparison, the corrections in other media were closer to unity with values from 0.966 (lung and RW3) to 0.991 (adipose tissue). Except for the PinPoint T31016, detector orientation-dependence was observed especially in high-density media. A good agreement (≤1.5%) was found between

D

m
,

Q

clin

m
,

f

clin

calculations and the detector readings corrected with the

h

Q

clin

,

Q

ref

f

clin

,

f

ref

det

m
,
w

factor for all studied heterogeneous phantoms. Significance. This paper could serve as an initial guideline for medical physicists involved in the validation of the advanced type-b dose calculation algorithms reporting

D

m
,

Q
clin

m
,

f
clin

. To our knowledge, this is the first study to assess the impact of the orientation of different detectors in heterogeneous media. The orientation dependence of the detector response observed in water may not reflect what is observed in heterogeneous media, especially in high-density media. The knowledge of the

h

Q

clin

,

Q

ref

f

clin

,

f

ref

det

m
,
w

factors becomes mandatory for accurate interpretation of detector readings and comparisons with

D

m
,

Q
clin

m
,

f
clin

calculations.
Solving the MPI reconstruction problem with automatically tuned regularization parameters
Authors: Scheffler Konrad , Boberg Marija , Knopp Tobias
Published: January 2024

In the field of medical imaging, magnetic particle imaging (MPI) poses a promising non-ionizing tomographic technique with high spatial and temporal resolution. In MPI, iterative solvers are used to reconstruct the particle distribution out of the measured voltage signal based on a system matrix. The amount of regularization needed to reconstruct an image of good quality differs from measurement to measurement, depending on the MPI system and the measurement settings. Finding the right choice for the three major parameters controlling the regularization is commonly done by hand and requires time and experience. In this work, we study the reduction to a single regularization parameter and propose a method that enables automatic reconstruction. The method is qualitatively and quantitatively validated on several MPI data sets showing promising results.
Evaluation of adjacent and opposite current injection patterns for a wearable chest electrical impedance tomography system
Authors: Yang Lin , Gao Zhijun , Wang Chunchen , Wang Hang , Dai Jing , Liu Yang , Qin Yilong , Dai Meng , Cao Xinsheng , Zhao Zhanqi
Published: January 2024

Objective. Wearable electrical impedance tomography (EIT) can be used to monitor regional lung ventilation and perfusion at the bedside. Due to its special system architecture, the amplitude of the injected current is usually limited compared to stationary EIT system. This study aims to evaluate the performance of current injection patterns with various low-amplitude currents in healthy volunteers. Approach. A total of 96 test sets of EIT measurement was recorded in 12 healthy subjects by employing adjacent and opposite current injection patterns with four amplitudes of small current (i.e. 1 mA, 500 uA, 250 uA and 125 uA). The performance of the two injection patterns with various currents was evaluated in terms of signal-to-noise ratio (SNR) of thorax impedance, EIT image metrics and EIT-based clinical parameters. Main results. Compared with adjacent injection, opposite injection had higher SNR (p < 0.01), less inverse artifacts (p < 0.01), and less boundary artifacts (p < 0.01) with the same current amplitude. In addition, opposite injection exhibited more stable EIT-based clinical parameters (p < 0.01) across the current range. For adjacent injection, significant differences were found for three EIT image metrics (p < 0.05) and four EIT-based clinical parameters (p < 0.01) between the group of 125 uA and the other groups. Significance. For better performance of wearable pulmonary EIT, currents greater than 250 uA should be used in opposite injection, 500 uA in adjacent one, to ensure a high level of SNR, a high quality of reconstructed image as well as a high reliability of clinical parameters.
ECG data enhancement method using generate adversarial networks based on Bi-LSTM and CBAM
Authors: Zhou Feiyan , Li Jiajia
Published: January 2024

Objective. The classification performance of electrocardiogram (ECG) classification algorithms is easily affected by data imbalance, which often leads to poor model prediction performance for a few classes and a consequent decrease in the overall performance of the model. Approach. To address this problem, this paper proposed an ECG data augmentation method based on a generative adversarial network (GAN) that combines bidirectional long short-term memory (Bi-LSTM) networks and convolutional block attention mechanism (CBAM) to improve the overall performance of ECG classification models. In this paper, we used two ECG databases, namely the MIT-BIH arrhythmia (MIT-BIH-AR) database and the Chinese cardiovascular disease database (CCDD). The quality of the ECG signals produced by the generated models was assessed using the percent relative difference, root mean square error, Frechet distance, dynamic time warping (DTW), and Pearson correlation metrics. In addition, we also validated the impact of our proposed data augmentation method on ECG classification performance on MIT-BIH-AR database and CCDD. Main results. On the MIT-BIH-AR database, the overall accuracy of the data-enhanced balanced dataset was improved to 99.46% for 15 types of heartbeat classification task. On the CCDD, which focuses on the detection of ventricular precession (PVC), the overall accuracy of PVC detection improved to 99.15% after performing data enhancement. Significance. The experimental results indicate that the data augmentation method proposed in this paper can further improve the ECG classification performance.
Dynamic control of reflection from a metasurface with distinct modulating mechanisms
Authors: Liu Simin , Pang Yongqiang , Qu Bingyue , Li Yongfeng , Wang Jiafu , Xu Zhuo
Published: January 2024

Dynamic control of the reflection from an object is much of importance in microwave engineering. In the past the tunable absorbers are usually employed to realize this goal and have been widely discussed. In this work, we propose a metasurface to offer a more flexible solution to dynamically control the reflection property. The proposed metasurface can be independently modulated by three distinct physical mechanisms. Apart from the absorption mechanism as the conventional tunable absorbers, the reflectivity of the proposed metasurface can be dynamically controlled by modulating the phase distribution profiles in the space as well as the time domains. Such flexibly dynamic reflection controlling ability is demonstrated by a series of experimental measurements. Results indicate that the tuning level of the reflectivity is more than 10 dB in a broad frequency band for the three distinct mechanisms. The proposal may find promising application in various fields, such as wireless communications and the stealth technology.
Travelling wave solutions of the Rosenau equation using exp(±φ(ξ))-expansion method*
Authors: Lin Fubiao , Yang Yang , Yang Xinxia , Zhang Qianhong
Published: January 2024

The Rosenau equation has been widely used to describe important physical phenomena and dynamic processes in physics, many numerical techniques have been presented in current literature. However, it is typically difficult to obtain exact solutions and analytical methods of this equation. In this paper, the

exp
(
±
φ
(
ξ
)
)

-expansion method is proposed by making full use of the classical Burgers equation, which can be applied to find a large number of travelling wave solutions of the Rosenau equation. These obtained solutions are novel and crucial for explaining exactly certain physical wave phenomena. The method provides an extensive applicability for solving nonlinear evolution partial differential equations.
One-step additive LIFT printing of conductive elements
Authors: Nastulyavichus Alena , Kudryashov Sergey , Shelygina Svetlana , Ulturgasheva Evgenia , Dzhun Irina , Krikunova Polina , Pallaeva Тatiana , Minh Pham Hong , Duong Pham Van , Gonchukov Sergey
Published: January 2024

The feasibility of printing silver and copper conductive elements on a glass substrate in a one- step through the laser-induced forward transfer method has been successfully demonstrated. The topography of the resulting elements was analyzed, using scanning electron microscopy. Investigation of their chemical composition was conducted by means of energy-dispersive x-ray spectroscopy and x-ray diffraction, revealing that both silver and copper in their metallic nanocrystalline state. The maximum specific conductivity of ≈6 kS cm−1 was achieved for both silver and copper at the optimal scanning speed of 3800 mm s−1, providing two-pulse printing with the laser transfer by the first pulse and laser annealing by the second one. The proposed method facilitates the technological additive printing process of conductive elements and rises its throughput.
Presentation of the Berry–Tabor conjecture in Lévy plates
Authors: Li 李 Chao 超 , Hou 侯 Guo-Lin 国林
Published: January 2024

The Berry–Tabor (BT) conjecture is a famous statistical inference in quantum chaos, which not only establishes the spectral fluctuations of quantum systems whose classical counterparts are integrable but can also be used to describe other wave phenomena. In this paper, the BT conjecture has been extended to Lévy plates. As predicted by the BT conjecture, level clustering is present in the spectra of Lévy plates. The consequence of level clustering is studied by introducing the distribution of nearest neighbor frequency level spacing ratios

P

(

r
∼

)

, which is calculated through the analytical solution obtained by the Hamiltonian approach. Our work investigates the impact of varying foundation parameters, rotary inertia, and boundary conditions on the frequency spectra, and we find that

P

(

r
∼

)

conforms to a Poisson distribution in all cases. The reason for the occurrence of the Poisson distribution in the Lévy plates is the independence between modal frequencies, which can be understood through mode functions.
α-particle preformation factors in heavy and superheavy nuclei*
Authors: Luo 骆 Song 松 , Zhang 张 Dong-Meng 冬萌 , Qi 亓 Lin-Jing 林静 , Chen 陈 Xun 勋 , Chu 初 Peng-Cheng 鹏程 , Li 李 Xiao-Hua 小华
Published: January 2024

In this study, α-particle preformation factors in heavy and superheavy nuclei from 220Th to 294Og are investigated. By combing experimental α decay energies and half-lives, the α-particle preformation factors

are extracted from the ratios between theoretical α decay half-lives calculated using the Two-Potential Approach (TPA) and experimental data. We find that the α-particle preformation factors exhibit a noticeable odd-even staggering behavior, and unpaired nucleons inhibit α-particle preformation. Moreover, we find that both the α decay energy and mass number of parent nucleus exhibit considerable regularity with the extracted experimental α-particle preformation factors. After considering the major physical factors, we propose a local phenomenological formula with only five valid parameters for α-particle preformation factors

. This analytic expression has a clear physical meaning as well as good precision. As an application, this analytic formula is extended to estimate the α-particle preformation factors and further predict the α decay half-lives for unknown even-even nuclei with Z = 118 and 120.
A comparative analysis of the cytocompatibility, protein adsorption, osteogenic and angiogenic properties of the 45S5- and S53P4-bioactive glass compositions
Authors: Westhauser Fabian , Arango-Ospina Marcela , Hupa Leena , Renkawitz Tobias , Boccaccini Aldo R , Kunisch Elke
Published: January 2024

Despite their long history of application in orthopedics, the osteogenic and angiogenic properties as well as the cytocompatibility and protein adsorption of the 45S5- (in wt%: 45.0 SiO2, 24.5 Na2O, 24.5 CaO, 6.0 P2O5) and S53P4- (in wt%: 53.0 SiO2, 23.0 Na2O, 20.0 CaO, 4.0 P2O5) bioactive glass (BG) compositions have not yet been directly compared in one and the same experimental setting. In this study, the influence of morphologically equal granules of both BGs on proliferation, viability, osteogenic differentiation and angiogenic response of human bone-marrow-derived mesenchymal stromal cells (BMSCs) was assessed. Furthermore, their impact on vascular tube formation and adsorption of relevant proteins was evaluated. Both BGs showed excellent cytocompatibility and stimulated osteogenic differentiation of BMSCs. The 45S5-BG showed enhanced stimulation of bone morphogenic protein 2 (BMP2) gene expression and protein production compared to S53P4-BG. While gene expression and protein production of vascular endothelial growth factor (VEGF) were stimulated, both BGs had only limited influence on tubular network formation. 45S5-BG adsorbed a higher portion of proteins, namely BMP2 and VEGF, on its surface. In conclusion, both BGs show favorable properties with slight advantages for 45S5-BG. Since protein adsorption on BG surfaces is important for their biological performance, the composition of the proteome formed by osteogenic cells cultured on BGs should be analyzed in order to gain a deeper understanding of the mechanisms that are responsible for BG-mediated stimulation of osteogenic differentiation.
Optimization of hybrid gelatin-polysaccharide bioinks exploiting thiol-norbornene chemistry using a reducing additive
Authors: Carpentier Nathan , Parmentier Laurens , Van der Meeren Louis , Skirtach André G , Dubruel Peter , Van Vlierberghe Sandra
Published: January 2024

Thiol-norbornene chemistry offers great potential in the field of hydrogel development, given its step growth crosslinking mechanism. However, limitations exist with regard to deposition-based bioprinting of thiol-containing hydrogels, associated with premature crosslinking of thiolated (bio)polymers resulting from disulfide formation in the presence of oxygen. More specifically, disulfide formation can result in an increase in viscosity thereby impeding the printing process. In the present work, hydrogels constituting norbornene-modified dextran (DexNB) combined with thiolated gelatin (GelSH) are selected as case study to explore the potential of incorporating the reducing agent tris(2-carboxyethyl)phosphine (TCEP), to prevent the formation of disulfides. We observed that, in addition to preventing disulfide formation, TCEP also contributed to premature, spontaneous thiol-norbornene crosslinking without the use of UV light as evidenced via 1H-NMR spectroscopy. Herein, an optimal concentration of 25 mol% TCEP with respect to the amount of thiols was found, thereby limiting auto-gelation by both minimizing disulfide formation and spontaneous thiol-norbornene reaction. This concentration results in a constant viscosity during at least 24 h, a more homogeneous network being formed as evidenced using atomic force microscopy while retaining bioink biocompatibility as evidenced by a cell viability of human foreskin fibroblasts exceeding 70% according to ISO 10993-6:2016.
Nanoparticles loaded with β-Lapachone and Fe3+ exhibit enhanced chemodynamic therapy by producing H2O2 through cascaded amplification
Authors: Yang Yibo , Zhang Jia , Liu Shihe , Zhang Xin , Bai Zhimin , Wang Shuai , Li Kun , Shi Ming , Liu Zhiwei , Wang Jidong , Li Jian
Published: January 2024

The rapid, irreversible change of active Fe2+ to inactive Fe3+ after the Fenton reaction occurring reduces the chemodynamic therapeutic (CDT) effect. Therefore, manipulation of the tumor microenvironment to provide sufficient hydrogen peroxide (H2O2) while maintaining metal ion catalyst activity is critical for effective CDT. Here, β-Lapachone (LPC) was loaded by mesoporous silica nanoparticles (MSNs) and coated with polydopamine (PDA) to further chelate Fe3+ and link aptamer AS1411, and a pH-controlled released, chemotherapy-photothermal therapy (PTT)-enhanced CDT-small molecule therapy combination drug delivery system with passive and active tumor targeting was engineered (designated as β-LPC@MSN@PDA/Fe3+-AS1411, LMPFA). The results showed that LFMPA nanoparticles massively accumulated in tumor tissues to achieve tumor targeting through AS1411 mediating and enhanced permeability and retention (EPR) effect. Subsequently, PDA released Fe3+ and LPC through acid response to exhibited CDT and chemotherapeutic therapy. Meanwhile, the photothermal effect of PDA promoted the release of LPC from the pores of MSN. LPC exerted chemotherapy effect and cyclically producing of H2O2 by the catalysis of NQO1, which enhanced the CDT activated by Fe3+. In addition, while serving as a targeted ligand, AS1411 could also exhibit a small molecule therapeutic effect by binding to nucleoli of tumor cells. This unique nano delivery system achieved the combination of chemotherapy, PTT, enhanced CDT and small molecule therapy, and fought against malignant tumors synergistically through multi-target and multi-dimension.
Characteristics of extra-oral halitosis induced by functional constipation: a prospective cohort study
Authors: Qian Xiao Xian
Published: January 2024

Characteristics of extra-oral halitosis induced by functional constipation (FC) have never been revealed. To address this, this prospective cohort was conducted with 100 FC patients, who were divided into a halitosis group and a negative group. Organoleptic score (OLS) ⩾ 2 in nose breath was diagnosed as extra-oral halitosis. Concentration of overall volatile sulfur compounds (VSCs) measured by Halimeter, concentration of hydrogen sulfide (HS), methanethiol (MT), dimethyl sulfide (DMS) and their total amount measured by OralChroma in nose breath was recorded as C-VSC, C-HS, C-MT, C-DMS and C-sum respectively. We found that 82% (82/100) of the FC patients had extra-oral halitosis. However, only 12.5% (3/82) and 1.22% (1/82) of halitosis group were correctly diagnosed with the current diagnostic threshold of C-VSC ⩾ 110 parts per billion (ppb) and ⩾150 ppb. C-VSC, C-DMS and C-sum were significantly higher in the halitosis group compared to the negative group (all P < 0.001), with ratios of about 2.2 times, 3.1 times and 2.1 times respectively. C-HS and C-MT were low and not significantly different between the groups. Positive correlations were observed among OLS, C-VSC, C-DMS and C-sum. The area under curve of receiver operating characteristics of C-VSC, C-DMS and C-sum for predicting FC-induced halitosis was 0.909, 0.9073 and 0.962 respectively, with the threshold values of ⩾36 ppb, ⩾52 ppb and ⩾75 ppb respectively. Therefore, we conclude that: (1) DMS is the primary contributor to FC-induced extra-oral halitosis. (2) OLS, Halimeter and OralChroma are consistent in detecting FC-induced extra-oral halitosis. (3) The diagnostic threshold for Halimeter should be adjusted to C-VSC ⩾ 36 ppb and the diagnostic threshold for OralChroma should be set as C-DMS ⩾ 52 ppb for diagnosing FC-induced extra-oral halitosis.
Transient slow motion of a porous sphere
Authors: Yu Chan W , Keh Huan J
Published: January 2024

The start-up creeping motion of a porous spherical particle, which models a permeable polymer coil or floc of nanoparticles, in an incompressible Newtonian fluid generated by the sudden application of a body force is investigated for the first time. The transient Stokes and Brinkman equations governing the fluid velocities outside and inside the porous sphere, respectively, are solved by using the Laplace transform. An analytical formula for the transient velocity of the particle as a function of relevant parameters is obtained. As expected, the particle velocity increases over time, and a particle with greater mass density lags behind a corresponding less dense particle in the growth of the particle velocity. In general, the transient velocity is an increasing function of the porosity of the particle. On the other hand, a porous particle with a higher fluid permeability will have a greater transient velocity than the same particle with a lower permeability, but may trail behind the less permeable particle in the percentage growth of the velocity. The acceleration of the porous particle is a monotonic decreasing function of the elapsed time and a monotonic increasing function of its fluid permeability. In particular, the transient behavior of creeping motions of porous particles may be much more important than that of impermeable particles.
Environmental regulation, energy consumption structure, and industrial pollution emissions
Authors: Chen Fangli , Shao Mimi , Chen Weitong , Wang Furu
Published: January 2024

China has become the world’s largest carbon emitter due to its high-investment, low-efficiency development model. It is urgent to reduce industrial pollution emissions. This study analyzes the impact of environmental regulation intensity and energy consumption structure on industrial SO2 pollution emissions by establishing a fixed-effect regression model based on panel data from 2009 to 2018 in China. The results show that the overall environmental regulation intensity in China has a significant negative effect on industrial pollution emissions. In other words, increasing the level of environmental regulation is conducive to reducing industrial pollution emissions. The proportion of coal consumption in the overall national energy consumption structure directly and positively correlated with the concentration of industrial pollution emissions. Due to the differences in economic development and industrial foundation, the pollution emissions effect shows significant heterogeneity in the eastern and western regions of China under the constraint of environmental regulation. Based on these conclusions, this article proposes policy recommendations from four aspects: (1) strengthen environmental regulation, and pay attention to optimize the form of environmental regulation. For example, in the West of China, the government can encourage enterprises to carry out technological innovation and develop green energy hubs by policy and financial support; (2)improve the energy consumption structure, such as encouraging green production; (3) promote industrial structure adjustment and upgrading, such as promoting the energy saving transformation of energy-intensive enterprises, developing green technologies, and reducing the carbon emissions of industrial industries; (4)improve the foreign investment access system and guiding foreign investment to invest in key environmental protection projects.
Luminance and chromaticity characteristics of different phosphor types in laser lighting
Authors: Jensen Ole Bjarlin , Chen Xinrong , Xu Jian , Corell Dennis Dan , Dam-Hansen Carsten
Published: January 2024

Laser lighting is emerging as a viable replacement for other light sources in applications requiring high luminance not achievable with LEDs. Phosphor materials for laser lighting are often optimized in terms of luminous efficiency and/or colorimetric properties, while the light homogeneity is often neglected. We present a thorough investigation of the homogeneity of the chromaticity and the luminance profile for the most common types of phosphors used in laser lighting. We find that the achievable luminance and homogeneity of the light spot depends significantly on the phosphor used to convert the blue laser light to white light. The findings of these investigations will present guidelines for optimal phosphor material parameters to achieve high luminance combined with homogeneous chromaticity.
Combining simulation models and machine learning in healthcare management: strategies and applications
Authors: Ponsiglione Alfonso Maria , Zaffino Paolo , Ricciardi Carlo , Di Laura Danilo , Spadea Maria Francesca , De Tommasi Gianmaria , Improta Giovanni , Romano Maria , Amato Francesco
Published: January 2024

Simulation models and artificial intelligence (AI) are largely used to address healthcare and biomedical engineering problems. Both approaches showed promising results in the analysis and optimization of healthcare processes. Therefore, the combination of simulation models and AI could provide a strategy to further boost the quality of health services. In this work, a systematic review of studies applying a hybrid simulation models and AI approach to address healthcare management challenges was carried out. Scopus, Web of Science, and PubMed databases were screened by independent reviewers. The main strategies to combine simulation and AI as well as the major healthcare application scenarios were identified and discussed. Moreover, tools and algorithms to implement the proposed approaches were described. Results showed that machine learning appears to be the most employed AI strategy in combination with simulation models, which mainly rely on agent-based and discrete-event systems. The scarcity and heterogeneity of the included studies suggested that a standardized framework to implement hybrid machine learning-simulation approaches in healthcare management is yet to be defined. Future efforts should aim to use these approaches to design novel intelligent in-silico models of healthcare processes and to provide effective translation to the clinics.
Holistic evaluation of involute gear surfaces using 3D point cloud inversion
Authors: Przyklenk Anita , Reavie Tom , Stein Martin , Frazer Robert
Published: January 2024

Gear users desire increased performance from their products and are interested in predicting the behavior (vibration, loss, service life, etc), and gear manufacturers are interested in adjusting machining parameters to manufacture even better gears. Both require proficient metrology. The evaluation standards were originally written to classify the manufacturing capability of machine tools and as tolerances tighten they may not provide enough insight into the functional performance of the manufactured parts. Furthermore, the advantage of modern coordinate and gear measuring machines is not fully taken into account when applying standardized measurement and evaluation strategies. Improved analysis tools can increase the relevant information gained from current measurement capabilities and enable more useful functional characteristics to be specified by designers and manufacturers. A key improvement is to move from profile and helix line traces to flank surfaces and corresponding fitted form elements. This is achieved by the introduced method. We present an inversion algorithm that fits dimension, form, and pose, and is applicable with current methods through freezing of specific fitting parameters. The method fits a synthetic point cloud with output results that are accurate to the 7th digit, or in practical terms are numerically equal. The inversion method can increase the understanding of error contributions and the functional performance of gears.
Innovative triboelectric nanogenerator (TENG) design utilizing a stress ball for energy harvesting, wellness, and safety applications
Authors: Lakshakoti B , Sankar P Ravi , Supraja P , Navaneeth M , Mahesh V , Kumar K Uday , Prakash K , Kumar R Rakesh
Published: January 2024

The present manuscript introduces a cost-effective and simple method for creating a Triboelectric nanogenerator (TENG) that utilizes a stress ball as a base and FEP, Aluminum as triboelectric pairs. The TENG design demonstrates an innovative approach that can be used for energy harvesting, stress relief, and human safety simultaneously. The unique aspect of this TENG design is using a Polyurethane foam-based ball (Stress-Ball) with excellent elasticity as a spacer, eliminating the need for additional spacers. The TENG prototype produced a power density of 625 mW m−2 and 1.75 W m−2 in squeezing and tapping mode, respectively. Furthermore, four TENG devices integrated in the prototype tiles enable electrical energy generation to power 720 LEDs with every casual footstep. The TENG converts biomechanical energy produced from hand-squeezing exercises into electrical energy that can power small, wearable, and portable electronic devices such as calculators, thermometers, and watches. Wearable LEDs powered by squeezing the ball while walking on dark roads provided safety applications. Overall, the presented TENG design showcases an efficient and affordable way of generating electrical energy while also promoting human wellness and safety.
Tribological and impact- toughness performance of friction stir processed AA7075
Authors: Kumar Amit , Kumar Vineet
Published: January 2024

This technical investigation used friction stir processing to modify the AA7075- T6 alloy and aimed to analyze the wear and impact toughness properties of the modified surfaces. Effects of the input parameters of the friction stir process (FSP) were also studied. Initially, the as-received AA-7075 alloy was processed using FSP at the selected parameters to get defect-free processed specimens. Next, the microstructures of the base alloy and processed regions were examined through an optical microscope. Then, the impact toughness was measured using the Charpy test, and sliding wear behavior was evaluated on a pin-on-disc tribo-tester. The processed samples’ average impact energy was better than the base material’s. Also, their wear property, i.e., coefficient of friction and weight loss, were more promising than the parent metal. Finally, fractography of the fractured Charpy test sampleswas done to study the fracture behavior; andSEM micrographs and 2D profiles of wear tracks were analysed to examine the wear behaviour properly.
Nanoscale dielectric properties of TiO2 in SiO2 nanocomposite deposited by hybrid PECVD method
Authors: Villeneuve-Faure C , Mitronika M , Dan A P , Boudou L , Ravisy W , Besland M P , Richard-Plouet M , Goullet A
Published: January 2024

In this paper, nanocomposites (TiO2 in SiO2) are produced by an advanced hybrid aerosol-PECVD method based on direct liquid injection of a non-commercial colloidal solution in an O2 / hexamethyldisiloxane (HMDSO) low-pressure plasma. Dielectric properties are investigated at nanoscale using techniques derived from Atomic Force Microcopy in terms of relative dielectric permittivity, charge injection and transport. Results show that a concentration in TiO2 up to 14% by volume makes it possible to increase the relative dielectric permittivity up to 4.8 while maintaining the insulating properties of the silica matrix. For a TiO2 concentration in the range 15%–37% by volume, the relative dielectric permittivity increases (up to 11 for 37% TiO2 by volume) and only few agglomerated nanoparticles lowering the insulating properties are observed. For TiO2 concentration above 40% by volume, the relative dielectric permittivity still increases but the quantity of agglomerated nanoparticles is very high, which greatly increases the charge transport dynamic and degrades the insulating properties. Finally, 37% of TiO2 by volume in the SiO2 matrix appears to be the best compromise, between high dielectric permittivity and low leakage current for the MIM applications aimed.
Drivers of heterogeneity in tundra vegetation productivity on the Yamal Peninsula, Siberia, Russia
Authors: Tassone Morgan S , Epstein Howard E , Armstrong Amanda H , Bhatt Uma S , Frost Gerald V , Heim Birgit , Raynolds Martha K , Walker Donald A
Published: January 2024

The direction and magnitude of tundra vegetation productivity trends inferred from the normalized difference vegetation index (NDVI) have exhibited spatiotemporal heterogeneity over recent decades. This study examined the spatial and temporal drivers of Moderate Resolution Imaging Spectroradiometer Max NDVI (a proxy for peak growing season aboveground biomass) and time-integrated (TI)-NDVI (a proxy for total growing season productivity) on the Yamal Peninsula, Siberia, Russia between 2001 and 2018. A suite of remotely-sensed environmental drivers and machine learning methods were employed to analyze this region with varying climatological conditions, landscapes, and vegetation communities to provide insight into the heterogeneity observed across the Arctic. Summer warmth index, the timing of snowmelt, and physiognomic vegetation unit best explained the spatial distribution of Max and TI-NDVI on the Yamal Peninsula, with the highest mean Max and TI-NDVI occurring where summer temperatures were higher, snowmelt occurred earlier, and erect shrub and wetland vegetation communities were dominant. Max and TI-NDVI temporal trends were positive across the majority of the Peninsula (57.4% [5.0% significant] and 97.6% [13.9% significant], respectively) between 2001 and 2018. Max and TI-NDVI trends had variable relationships with environmental drivers and were primarily influenced by coastal-inland gradients in summer warmth and soil moisture. Both Max and TI-NDVI were negatively impacted by human modification, highlighting how human disturbances are becoming an increasingly important driver of Arctic vegetation dynamics. These findings provide insight into the potential future of Arctic regions experiencing warming, moisture regime shifts, and human modification, and demonstrate the usefulness of considering multiple NDVI metrics to disentangle the effects of individual drivers across heterogeneous landscapes. Further, the spatial heterogeneity in the direction and magnitude of interannual covariation between Max NDVI, TI-NDVI, and climatic drivers highlights the difficulty in generalizing the effects of individual drivers on Arctic vegetation productivity across large regions.