bluuebunny/crossref_metadata_2025 huggingface dataset:
Block sparsity promoting algorithm for efficient construction of cluster expansion models for multicomponent alloys
Authors: Thekkepat Krishnamohan , Das Sumanjit , Prosad Dogra Debi , Gupta Kapil , Lee Seung-Cheol
Published: September 2023

Multicomponent alloys are gaining significance as drivers of technological breakthroughs especially in structural and energy storage materials. The vast configuration space of these materials prohibit computational modeling using first-principles based methods alone. The cluster expansion (CE) method is the most widely used tool for modeling configurational disorder in alloys. CE relies on machine learning algorithms to train Hamiltonians and uses first-principles calculated data as training sets. In this paper we present a new compressive sensing-based algorithm for the efficient construction of CE Hamiltonians of multicomponent alloys. Our algorithm constructs highly sparse and physically reasonable models from a carefully selected small training set of alloy structures. Compared to conventional fitting algorithms, the algorithm achieves more than 50% reduction in the training set size. The resultant sparse models can sample the configuration space at least 3 × faster. We demonstrate this algorithm on 4 different alloy systems, namely Ag–Au, Ag–Au–Cu, Ag–Au–Cu–Pd and (Ge,Sn)(S,Se,Te).The sparse CE models for these alloys can rapidly reproduce known ground state orderings and order-disorder transitions. Our method can truly enable high-throughput multicomponent alloy thermodynamics by reducing the cost associated with model construction and configuration sampling.
Physical binding energies using the electron localization function in 4-hydroxyphenylboronic acid co-crystals with aza donors
Authors: Shimpi Mayura Talwelkar , Sajjad Muhammad , Öberg Sven , Larsson J Andreas
Published: September 2023

Binding energies are traditionally simulated using cluster models by computation of each synthon for each individual co-crystal former. However, our investigation of the binding strengths using the electron localization function (ELF) reveals that these can be determined directly from the crystal supercell computations. We propose a new modeling protocol for the computation of physical binding energies directly from bulk simulations using ELF analysis. In this work, we establish a correlation between ELF values and binding energies calculated for co-crystals of 4-hydroxyphenylboronic acid (4HPBA) with four different aza donors using density functional theory with varying descriptions of dispersion. Boronic acids are gaining significant interest in the field of crystal engineering, but theoretical studies on their use in materials are still very limited. Here, we present a systematic investigation of the non-covalent interactions in experimentally realized co-crystals. Prior diffraction studies on these complexes have shown the competitive nature between the boronic acid functional group and the para-substituted phenolic group forming heteromeric interactions with aza donors. We determine the stability of the co-crystals by simulating their lattice energies, and the different dispersion descriptions show similar trends in lattice energies and lattice parameters. Our study bolsters the experimental observation of the boronic acid group as a competitive co-crystal former in addition to the well-studied phenolic group. Further research on correlating ELF values for physical binding could potentially transform this approach to a viable alternative for the computation of binding energies.
The effect of fission products Xe and Cs on the thermal conductivity of the U3Si2 lattice: a first-principles study
Authors: Qi Hangbo , Li Buda , Li Menglu , Feng Shan , Hu Jutao , Gong Hengfeng , Ren Qisen , Liao Yehong , Xiao Haiyan , Zu Xiaotao
Published: September 2023

In the past decades, uranium silicide (U3Si2) as a promising accident tolerant fuel (ATF) has drawn considerable attention in the field of nuclear physics. In comparison with traditional nuclear fuel (UO2), the U3Si2 has higher thermal conductivity and uranium density, thereby resulting in lower centerline temperatures and better fuel economy. However, during the nuclear fission reaction, some unexpected fission products, such as Xe and Cs, are released and form the defective states. In this study, we explore the influence of Xe and Cs on the thermal conductivity of the U3Si2 lattice from 200 to 1500 K using density functional theory calculations combined with Boltzmann transport equation. Our results reveal that the lattice and electronic thermal conductivities of defective U3Si2 are reduced at a constant temperature, as compared with that of ideal system, thus resulting in a decrease of the total thermal conductivity. In the case of Cs occupation at U1 site, the total thermal conductivity (4.42 W mK−1) is decreased by ∼56% at 300 K, as compared with the value of 9.99 W mK−1 for ideal system. With U1 and Si sites being occupied by Xe, the total thermal conductivities (4.45 and 6.52 W mK−1) are decreased by ∼55% and 35% at 300 K, respectively. The presented results suggest that the U3Si2 has potential as a promising ATF at high temperatures.
A unified path seeking algorithm for IMRT and IMPT beam orientation optimization
Authors: Ramesh Pavitra , Valdes Gilmer , O’Connor Daniel , Sheng Ke
Published: September 2023

Objective. Fully automated beam orientation optimization (BOO) for intensity-modulated radiotherapy and intensity modulated proton therapy (IMPT) is gaining interest, since achieving optimal plan quality for an unknown number of fixed beam arrangements is tedious. Fast group sparsity-based optimization methods have been proposed to find the optimal orientation, but manual tuning is required to eliminate the exact number of beams from a large candidate set. Here, we introduce a fast, automated gradient descent-based path-seeking algorithm (PathGD), which performs fluence map optimization for sequentially added beams, to visualize the dosimetric benefit of one added field at a time. Approach. Several configurations of 2–4 proton and 5–15 photon beams were selected for three head-and-neck patients using PathGD, which was compared to group sparsity-regularized BOO solved with the fast iterative shrinkage-thresholding algorithm (GS-FISTA), and manually selected IMPT beams or one coplanar photon VMAT arc (MAN). Once beams were chosen, all plans were compared on computational efficiency, dosimetry, and for proton plans, robustness. Main results. With each added proton beam, Clinical Target Volume (CTV) and organs at risk (OAR) dosimetric cost improved on average across plans by [1.1%, 13.6%], and for photons, [0.6%, 2.0%]. Comparing algorithms, beam selection for PathGD was faster than GS-FISTA on average by 35%, and PathGD matched the CTV coverage of GS-FISTA plans while reducing OAR mean and maximum dose in all structures by an average of 13.6%. PathGD was able to improve CTV [Dmax, D95%] by [2.6%, 5.2%] and reduced worst-case [max, mean] dose in OARs by [11.1%, 13.1%]. Significance. The benefit of a path-seeking algorithm is the beam-by-beam analysis of dosimetric cost. PathGD was shown to be most efficient and dosimetrically desirable amongst group sparsity and manual BOO methods, and highlights the sensitivity of beam addition for IMPT in particular.
Automatic brain extraction for rat magnetic resonance imaging data using U2-Net
Authors: Liang Shengxiang , Yin Xiaolong , Huang Li , Huang Jiayang , Yang Junchao , Wang Xiuxiu , Peng Lixin , Zhang Yusi , Li Zuanfang , Nie Binbin , Tao Jing
Published: September 2023

Objective. Skull stripping is a key step in the pre-processing of rodent brain magnetic resonance images (MRI). This study aimed to develop a new skull stripping method via U2-Net, a neural network model based on deep learning method, for rat brain MRI. Approach. In this study, 599 rats were enrolled and U2-Net was applied to segment MRI images of rat brain. The intercranial tissue of each rat was manually labeled. 476 rats (approximate 80%) were used for training set while 123 rats (approximate 20%) were used to test the performance of the trained U2-Net model. For evaluation, the segmentation result by the U2-Net model is compared with the manual label, and traditional segment methods. Quantitative evaluation, including Dice coefficient, Jaccard coefficient, Sensitivity, Specificity, Pixel accuracy, Hausdorff coefficient, True positive rate, False positive rate and the volumes of whole brain, were calculated to compare the segmentation results among different models. Main results. The U2-Net model was performed better than the software of RATS and BrainSuite, in which the quantitative values of training U2-Net model were 0.9907 ± 0.0016 (Dice coefficient), 0.9816 ± 0.0032 (Jaccard coefficient), 0.9912 ± 0.0020 (Sensitivity), 0.9989 ± 0.0002 (Specificity), 0.9982 ± 0.0003 (Pixel accuracy), 5.2390 ± 2.5334 (Hausdorff coefficient), 0.9902 ± 0.0025 (True positive rate), 0.0009 ± 0.0002(False positive rate) respectively. Significance. This study provides a new method that achieves reliable performance in rat brain skull stripping of MRI images, which could contribute to the processing of rat brain MRI.
B3X: a novel efficient algorithm for accurate automated auscultatory blood pressure estimation
Authors: Centracchio Jessica , De Caro Davide , Bifulco Paolo , Andreozzi Emilio
Published: September 2023

Objective. The auscultatory technique is still considered the most accurate method for non-invasive blood pressure (NIBP) measurement, although its reliability depends on operator’s skills. Various methods for automated Korotkoff sounds analysis have been proposed for reliable estimation of systolic (SBP) and diastolic (DBP) blood pressures. To this aim, very complex methodologies have been presented, including some based on artificial intelligence (AI). This study proposes a relatively simple methodology, named B3X, to estimate SBP and DBP by processing Korotkoff sounds recordings acquired during an auscultatory NIBP measurement. Approach. The beat-by-beat change in morphology of adjacent Korotkoff sounds is evaluated via their cross-correlation. The time series of the beat-by-beat cross-correlation and its first derivative are analyzed to locate the timings of SBP and DBP values. Extensive tests were performed on a public database of 350 annotated measurements, and the performance was evaluated according to the BHS, AAMI/ANSI, and International Organization for Standardization (ISO) quality standards. Main results. The proposed approach achieved ‘A’ scores for SBP and DBP in the BHS grading system, and passed the quality tests of AAMI/ANSI and ISO standards. The B3X algorithm outperformed two well-established algorithms for oscillometric NIBP measurement in both SBP and DBP estimation. It also outperformed four AI-based algorithms in DBP estimation, while providing comparable performance for SBP, at the cost of a much lower computational burden. The full code of the B3X algorithm is provided in a public repository. Significance. The very good performances ensured by the proposed B3X algorithm, at a low computational cost and without the need for parameter training, support its direct implementation into clinical blood pressure (BP) monitoring devices. The results of this study pave the way for solving/overcoming the trade-off between the accuracy of the auscultatory technique and the objectivity of oscillatory measurements, by bringing an automated auscultatory BP measurement method in clinical practice.
A novel bio-inspired helmet with auxetic lattice liners for mitigating traumatic brain injury
Authors: Chen Zeyao , Li Junhao , Wu Baisheng , Chen Xin , Ren Xin , Xie Yi Min
Published: September 2023

The human head is most vulnerable to injury during activities such as road traffic and sports. To mitigate the risk of traumatic brain injury (TBI), helmets serve as an important protective device. This study proposes a hedgehog biomimetic helmet with auxetic lattice liners in the shape of a hemisphere. The helmeted head impact configuration is built based on a high bio-fidelity head-neck finite element model incorporated into our novel helmet model. Biomechanical responses including acceleration, intracranial pressure, and von Mises strain of head are extracted from the simulation model to assess TBI risks. The results indicate that the helmet featuring auxetic lattice liners outperforms those without liners or with other liner designs, offering superior protection. Compared to the threshold, the novel helmet design was found to reduce the head injury criterion value by 72.65%. Additionally, parametric studies of lattice’s bar radius for uniform and graded auxetic lattice liners are discussed. Finally, this study also carries out the optimization design of lattice strut radius and height, resulting in a lightweight auxetic lattice liner with superior protective performance. The outcomes of this study extend the application of auxetic materials and provide guidance for designing helmet liners that better mitigate TBI.
Adaptive piezoelectric metamaterial beam: autonomous attenuation zone adjustment in complex vibration environments
Authors: Jian Yupei , Hu Guobiao , Tang Lihua , Shen Yincheng , Zhan Yulin , Aw Kean
Published: September 2023

Programmable metamaterials for broadband vibration control draw growing interest due to their abilities to tailor dynamic responses. However, the deterministic dynamic behavior of any traditional metamaterial is a challenge to cope with the complex and variable vibration conditions in real environments. This work proposes an adaptive piezoelectric metamaterial beam (piezo-meta-beam) that consists of bimorph piezoelectric arrays. The shunt circuits are designed with self-tuning abilities by integrating microcontroller-driven digital potentiometers into synthetic inductive circuits. Two typical scenarios are considered, i.e., harmonic and white noise excitations with different spectra. Different self-tuning strategies based on bandgap prediction are contrapuntally developed. However, a flaw in the analytical bandgap expression widely appearing in the literature is noted through a verification study. A modified bandgap expression based on the 3D finite element model is proposed for correction. This modified bandgap expression is adopted in formulating the control strategy of the microcontroller. A series of experiments are conducted to investigate the adaptive behavior of the piezo-meta-beam. In the harmonic sweep excitation test, the adaptive piezo-meta-beam shows an ultra-broad attenuation zone (220–720 Hz), while the traditional counterpart only has a bandgap width of less than 20 Hz. In the case of noise excitation, autonomous adjustment of the center frequency and attenuation zone is achieved for noises over different spectra. In general, this work presents a methodology for designing intelligent metamaterials that can adapt to environmental vibrations with vast potential for real applications.
Effects of vacancy defects on the electronic and magnetic properties of monolayer CrOCl
Authors: Xu Chunyan , Zhang Jing
Published: September 2023

Two-dimensional intrinsic ferromagnetic materials have received considerable attention for their potential applications in spintronic devices. The possible defects during experimental synthesis can affect the properties of magnets. However, the study of vacancies in two-dimensional ferromagnetic CrOCl is still lacking. Based on first-principles calculations, we investigate the electronic and magnetic properties of monolayer CrOCl by introducing vacancies. Vacancies transform monolayer CrOCl from semiconductor to half-metal. The magnetic moment of monolayer CrOCl can be modulated depending on the types of vacancies. Vacancy defects enhance the magnetic anisotropy of monolayer CrOCl but not alter the easy axis. By varying the concentration of Cl vacancy in monolayer CrOCl, the electronic property can be tuned from semiconductor to half-metal, the magnetic anisotropy can be improved by 133% compared to the pristine one. The controllability of the transition from ferromagnetic semiconductor to half-metallicity in monolayer CrOCl makes it an ideal spintronic material for spin injection and spin transport.
Synthesis of flower like microstructured CdZnS films for optoelectronic applications by powder vapor transport technique
Authors: Khan I A , Rasheed A , Farid A , Yousaf Misbah , Raza A
Published: September 2023

Cadmium zinc sulfide (CdZnS) is a remarkable semiconducting material used as window layer in solar cells. Herein, the flower’s like microstructured CdZnS film is synthesized by powder vapor transport (PVT) technique. The structural parameters like lattice constant, various diffraction planes, crystallinity, preferential orientation factor and standard deviation of CdZnS film of good quality growing preferentially along (110) orientations. The growth of longitudinal optical phonons modes at 303 and 599 cm−1 confirms the synthesis of CdZnS film. The values of transmittance and refractive index are ranged from 89.9%–95.2% and 1.53–2.67 whereas the values of energy band gap, oscillator energy and dispersion energy are found to be 2.79, 0.73 and 1.73 eV respectively. The values of dielectric constant are increased with increasing photon energy. The smaller values of dissipation factor and volume/surface energy loss functions of CdZnS film is suitable to make it a good quality capacitor. The electrical conductivity (1.68×103
S cm

−1
) of CdZnS film is increased nonlinearly with increasing temperature and the activation energy is found to be 0.31 eV. It is determined that the synthesized CdZnS film may be used as window layer in solar cells and to make good quality capacitor, hence it may be used in optoelectronic applications.
Excess noise factor measurement for low-noise high-speed avalanche photodiodes
Authors: Liu Yijun , Yang Xiaohong , Wang Rui , Tang Yongsheng
Published: September 2023

The excess noise factor(F) is an important parameter for Avalanche Photodiodes (APDs), indicating the extent to which the noise of the diodes exceeds what it would be without multiplication. This paper presents a method of measuring the excess noise factor for high-speed low-noise APDs using the high-sensitivity spectrum analyzer. The F factor test for the high-speed low-noise APDs was performed by comparing two conditions with and without illumination to remove the interference of the system, including the thermal noise and analyzers. The setup conditions of the light source are analyzed in detail. The F factor was obtained as 3.03 when the multiplication factor M is 10, which corresponds to an effective ionization coefficient ratio k of 0.14 for the high-speed InAlAs APD. For comparison, the k value of a commercial Si APD is tested to be ∼0.06.
High-order harmonic generation, attosecond pulse, and non-sequential double ionization in the helium atom under high-intensity femtosecond laser pulses
Authors: Zakavi Marjan , Sabaeian Mohammad
Published: September 2023

High-order harmonic generation (HHG), attosecond pulse train (APT), isolated attosecond pulse (IAP), and non-sequential double ionization (NSDI) in the Helium atom under intense femtosecond laser pulses are computed using the time-dependent Schrodinger equation (TDSE) in one dimension (1D). By taking into account the electron–electron and electron-nucleus interactions, as well as determining the Helium atom’s ground state wave function through the imaginary time propagation (ITP) method, we are able to observe the widely recognized ‘knee structure’ in the ionization probability of the Helium atom as a function of intensity within an ionization boundary condition model. The results are in good agreement with the experimental data reported by (Walker et al (1994) Phys. Rev. Lett. 73, 1227).
Spin wave-assisted enhanced current-driven domain wall movement
Authors: Gong Guangjian , Wang Yu , Hu Jingguo
Published: September 2023

The track memory based on current driven magnetic domain wall motion is a potential device for the next generation of magnetic information storage. To improve the speed of current driven domain wall motion and reduce the Joule heat, the relevant laws and physical mechanisms of the spin wave assisting current driven domain wall motion in long linear magnetic nanoribbons has been investigated to achieve spin wave assisted enhancement of current driven domain wall motion. The results show that the spin wave assisting can both enhances and weakens current driven domain wall motion depends on the driving current. Further research has shown that, for giving frequency spin waves, in the low current, spin wave assistance can enhance the current driven magnetic domain wall movement, and the enhancement of its movement speed increases non-monotonically with the increase of spin wave amplitude, but in the high current, spin wave assistance weakens the current driven magnetic domain wall movement, and the weakening of its movement speed nearly linear increases with the increase of spin wave amplitude. The critical current for distinguishing between the high and the low current depends on the amplitude and frequency of the assisting spin wave. On the other hand, for giving the amplitude spin wave, the increase or decrease of the spin wave assisting current driven domain wall motion exhibits a multimodal non-monotonic behavior as the frequency of the spin wave increases. Therefore, the appropriate spin wave assisting track storage technology can reduce the threshold current of track memory operation, making it more widely used. Also it can reduce Joule heat and improve the working efficiency of track memory.
Resting-state network predicts the decision-making behaviors of the proposer during the ultimatum game
Authors: Li Yuqin , Yang Qian , Liu Yuxin , Wang Rui , Zheng Yutong , Zhang Yubo , Si Yajing , Jiang Lin , Chen Baodan , Peng Yueheng , Wan Feng , Yu Jing , Yao Dezhong , Li Fali , He Baoming , Xu Peng
Published: September 2023

Objective. The decision-making behavior of the proposer is a key factor in achieving effective and equitable maintenance of social resources, particularly in economic interactions, and thus understanding the neurocognitive basis of the proposer’s decision-making is a crucial issue. Yet the neural substrate of the proposer’s decision behavior, especially from the resting-state network perspective, remains unclear. Approach. In this study, we investigated the relationship between the resting-state network and decision proposals and further established a multivariable model to predict the proposers’ unfair offer rates in the ultimatum game. Main results. The results indicated the unfair offer rates of proposers are significantly related to the resting-state frontal-occipital and frontal-parietal connectivity in the delta band, as well as the network properties. And compared to the conservative decision group (low unfair offer rate), the risk decision group (high unfair offer rate) exhibited stronger resting-state long-range linkages. Finally, the established multivariable model did accurately predict the unfair offer rates of the proposers, along with a correlation coefficient of 0.466 between the actual and predicted behaviors. Significance. Together, these findings demonstrated that related resting-state frontal-occipital and frontal-parietal connectivity may serve as a dispositional indicator of the risky behaviors for the proposers and subsequently predict a highly complex decision-making behavior, which contributed to the development of artificial intelligence decision-making system with biological characteristics as well.
Stochastic stability analysis of legged locomotion using unscented transformation
Authors: Er Güner Dilsad , Ankarali Mustafa Mert
Published: September 2023

In this manuscript, we present a novel method for estimating the stochastic stability characteristics of metastable legged systems using the unscented transformation. Prior methods for stability analysis in such systems often required high-dimensional state space discretization and a broad set of initial conditions, resulting in significant computational complexity. Our approach aims to alleviate this issue by reducing the dimensionality of the system and utilizing the unscented transformation to estimate the output distribution. This technique allows us to account for multiple sources of uncertainty and high-dimensional system dynamics, while leveraging prior knowledge of noise statistics to inform the selection of initial conditions for experiments. As a result, our method enables the efficient assessment of controller performance and analysis of parametric dependencies with fewer experiments. To demonstrate the efficacy of our proposed method, we apply it to the analysis of a one-dimensional hopper and an underactuated bipedal walking simulation with a hybrid zero dynamics controller.
Development of an impulsive motion generator inspired by cocking slip joint of snapping shrimp
Authors: Tajima Kiichi , Yagi Keisuke , Mori Yoshikazu
Published: September 2023

We propose an impulsive motion generator inspired by snapping shrimp. The proposed device mimics the geometrical arrangement of a unique claw joint called cocking slip joint and integrates it with an artificial rack-pinion actuator mechanism rather than adopting the musculoskeletal system as it is. The design approach allows the proposed device to reproduce the impulsive slip motion through the torque reversal and unlatching mechanism of the underlying unique joint by using a single servo motor. Static and dynamic analyses revealed that the actuator force required to store and release elastic energy was remarkably small compared with the resulting acceleration force and rotation/tip speed. Through simulations and experiments, we validated the mechanical analyses and confirmed that the resulting ultrafast slip motion was comparable with the claw closure of snapping shrimp based on the cocking slip joint. Moreover, from an engineering perspective, the motion profiles are modifiable through design parameters, and the repeatability of the impulsive slip motion is satisfactory.
Understanding the structural, electro-magnetic, mechanical, thermal and transport properties of Strontium based perovskite (SrPrO3)
Authors: Gautam Sakshi , Gupta Dinesh C
Published: September 2023

With the help of density functional theory, we have explored the structural, electro-magnetic, mechanical, thermal and transport properties of SrPrO3 perovskite. The optimization of energy reveals that the alloy is stable in ferromagnetic phase. The electronic and magnetic properties were calculated by generalized gradient approximation (GGA), Hubbard approximation (GGA + U) and Tran–Blaha modified Becke–Johnson (GGA+mBJ) potentials methods. The electronic structure depicts the half-metallic nature for the material in both the GGA and GGA+U approximations. The semiconducting nature is revealed by mBJ approximation. The elastic parameters reveal the ductile nature of the material. The response towards temperature and pressure of the different thermal parameters have also been evaluated with the help of quasi-harmonic Debye model. The thermoelectric potency of the material is measured in terms of Seebeck coefficient (S), electrical conductivity (σ/τ), thermal conductivity (κ), power factor and figure of merit (ZT). On the whole, these properties pose the possible applications of this material towards solid state device and thermoelectric sphere.
The growth mechanisms of TiO2 film onto PET surfaces by atomic layer deposition
Authors: Riyanto Edy , Dedi  , Fudholi Ahmad , Ying Guo , Jing Zhang , Jianjun Shi , Gaoshan Huang , Yongfeng Mei
Published: September 2023

Atomic layer deposition (ALD) was used to coat a polyethylene terephthalate (PET) polymer substrate with TiO2 film. The TiO2 was grown onto the surface with better film coverage by using thicker ALD deposition. Further evaluation on the coated substrates indicated that the reactive sites of –C=O that existed on PET surface played a significant contribution to facilitating the initial ALD growth of the TiO2 thin film. The chemical composition of the coated substrates was characterised using energy dispersive X-ray spectroscopy, which showed that increasing the TiO2 film thickness increased the Ti element content. Two growth mechanisms, namely, diffusion growth and direct coordination through the precursor coordination with surface reactive sites of –C=O with product release occurred simultaneously in the initial growth of TiO2 coating onto PET polymer by ALD. The surface alteration of the coated ALD was characterised by Fourier transform infrared spectroscopy, which showed that the hydroxyl –OH groups emerged in the TiO2 ALD film.
Model based aircraft design and optimization: a case study with cessna 172N aircraft
Authors: Özdemir Mustafa , Kurtuluş D. Funda
Published: September 2023

This study aims to create an interdisciplinary, multi-level design approach for fixed wing aircrafts. A case study is performed using Cessna 172N aircraft characteristics that is based on a mathematical model having six degrees of freedom (DOF). A Model Based Aircraft Design Software (MAD) is developed using a mathematical dynamic model in Python environment for use in the optimization phase of the Cessna 172N aircraft. The MAD environment is composed of analysis tools that communicate with each other by an automated process chain system. The model includes aerodynamics, engine, mass, control, atmosphere, and landing gear submodules. In addition, the model has trim and 6 DOF simulation analysis capabilities which provide a diversity of analyses that can be considered in early design phases. In order to get trimming and simulation capability, MAD software does not need any precalculated aerodynamic database. The force and moment calculations are performed instantly via DATCOM and AVL solvers for each iteration of simulation or trim. Thanks to this method, alternative aircraft geometries can be compared at the first phase of the design and optimization processes without creating an overall database. All methodologies of model submodules, performance, stability and control calculations, design, and optimization applications are implemented in the MAD environment.
Role of entropy in fault diagnosis of mechanical equipment: a review
Authors: Wang Zihan , Sun Yongjian
Published: September 2023

Mechanical equipment is widely used in daily life and production manufacturing, and it is an indispensable part of modern society. Fault diagnosis of mechanical equipment can effectively diminish catastrophic failures and significant economic losses. How to evaluate their status is the key problem of safe operation. The monitoring data of mechanical equipment obtained by sensors can be used to analyze potential problems and fault information. The vibration signal is the most easily obtained and commonly used monitoring data of mechanical equipment. But the vibration signal is unstable and usually shows nonlinear characteristics in actual measurement, which makes it difficult to extract fault features. Entropy can quantify the complexity of time series and detect the dynamic change of nonlinear behavior. Relying on the performance of entropy, it can be used as an effective tool for dynamic characteristics and applied to the fault diagnosis of mechanical equipment. The purpose of this paper is to summarize the related research of mechanical equipment fault diagnosis based on entropy methods in recent five years. Different entropy methods are classified, and specific application methods are introduced. On this basis, these entropy methods are deeply discussed. The gaps filled by different entropy methods in mechanical equipment fault diagnosis are discussed. The problems faced by entropy methods in the application of mechanical equipment fault diagnosis are also discussed. Theoretical and engineering guidance of mechanical fault diagnosis research is provided, which is of great significance.
Mechanical characterization of FDM printed bio-inspired double arrow head structures
Authors: Sanjay A , Joshua R Nekin , Aravind Raj S
Published: September 2023

Biomimetic structures draw their inspiration from nature. Biomimetic structures aim to improve strength, flexibility, and energy efficiency. Safety equipment, aircraft, automotive, and medical equipment incorporate biomimetic structures. In recent days, biomimetic structures were modified by researchers to enhance their mechanical properties. In this study, novel double arrowhead structures were manufactured using material extrusion technology, and the quasi-static compression tests were carried out in the Universal Testing Machine. Finally, the results demonstrated that the highest compressive strength is 13.29 MPa recorded on a modified novel solid square double arrowhead structure. Once more, the solid square double arrowhead structure has more specific strength than every other structure. A greater specific strength indicates that a structure is capable of withstanding greater forces while minimising its weight. In order to provide direction for the practical applications of lightweight materials, this research compares the truss double arrowhead structures with the solid double arrow head structures.
Micro-heater embedded ISFET pH sensor with high-k gate dielectrics for enhanced sensitivity
Authors: Hossain Salvir , Rahman Md Tawabur
Published: September 2023

The measurement of pH is an important routine practice in many chemical and biomedical applications. This work reports the design of a pH sensor based on the Ion Sensitive Field Effect Transistor (ISFET). The COMSOL Multiphysics® platform has been used to model and simulate the pH sensor in three dimensions (3D) while combining heat transport, electrostatic, and semiconductor modules. The binding of ions in gate dielectrics results in induced charge carriers in the conducting channel of 3D ISFET, which is controlled by the applied gate voltage for determining ion concentration. Here, the pH of water as the bulk electrolyte is measured by attaining the required gate voltage to achieve a certain drain current in 3D ISFET. The pH sensitivity of 3D ISFET with different high-k gate dielectrics such as Ta2O5, Al2O3, HfO2, ZrO2, and SiO2 is measured and compared. The 3D ISFET with Ta2O5 exhibited excellent sensitivity of 59.0 mV pH−1 with a wide linear detection range of pH from 1 to 13 at room temperature compared to other high-k gate dielectrics. Furthermore, the sensitivity was further enhanced to 66.0 mV pH−1 at 60 °C due to the incorporation of a micro-heater into the ISFET. The excellent sensitivity and wide linear detection range can be attributed to the high concentration of surface sites in the Ta2O5 sensing film and improved disassociation constants in the presence of the gate dielectric in contact with the electrolyte. Finally, this sensor demonstrates its potential for real applications.
Identifying Mediators of Intervention Effects Within a Randomized Controlled Trial to Motivate Cancer Genetic Risk Assessment Among Breast and Ovarian Cancer Survivors
Authors: An Jinghua , Lu Shou-En , McDougall Jean , Walters Scott T , Lin Yong , Heidt Emily , Stroup Antoinette , Paddock Lisa , Grumet Sherry , Toppmeyer Deborah , Kinney Anita Y
Published: September 2023

Background

A theory-guided Tailored Counseling and Navigation (TCN) intervention successfully increased cancer genetic risk assessment (CGRA) uptake among cancer survivors at increased risk of hereditary breast and ovarian cancer (HBOC). Understanding the pathways by which interventions motivate behavior change is important for identifying the intervention’s active components.

Purpose

We examined whether the TCN intervention exerted effects on CGRA uptake through hypothesized theoretical mediators.

Methods

Cancer survivors at elevated risk for HBOC were recruited from three statewide cancer registries and were randomly assigned to three arms: TCN (n = 212), Targeted Print (TP, n = 216), and Usual Care (UC, n = 213). Theoretical mediators from the Extended Parallel Process Model, Health Action Planning Approach, and Ottawa Decision Support Framework were assessed at baseline and 1-month follow-up; CGRA uptake was assessed at 6 months. Generalized structural equation modeling was used for mediation analysis.

Results

The TCN effects were most strongly mediated by behavioral intention alone (β = 0.49 and 0.31) and by serial mediation through self-efficacy and intention (β = 0.041 and 0.10) when compared with UC and TP, respectively. In addition, compared with UC, the TCN also increased CGRA through increased perceived susceptibility, knowledge of HBOC, and response efficacy.

Conclusions

Risk communication and behavioral change interventions for hereditary cancer should stress a person’s increased genetic risk and the potential benefits of genetic counseling and testing, as well as bolster efficacy beliefs by helping remove barriers to CGRA. System-level and policy interventions are needed to further expand access.
Reimagining the Past to Construct the Future: Nostalgia and Netflix’s She-Ra
Authors: Austin Sara
Published: September 2023

Netflix’s She-Ra (2018) is an example of how nostalgia-based children’s culture uses speculative fiction to reimagine the past while commenting on the present. The new She-Ra papers over shortcomings in the original show, rewriting adults’ memories of the character. She-Ra, and shows like it, allow adults to experience nostalgia for childhood media and toys by rewriting potentially unpleasant aspects of these thirty-year-old narratives. Though She-Ra uses characters and imagery familiar to parents, the show changes fundamental elements of the original to reflect contemporary social justice concerns, using its science-fiction elements to access political commentary including environmental degradation and coalition building. I will read the television show alongside recently released merchandise which depicts both the new and the 1985 versions of the character. Accessing the new and original versions of the character allows parents to both connect to contemporary children’s programming and reimagine their own childhoods through a contemporary social justice lens. As major producers of children’s culture such as Disney and Netflix embrace the nostalgia trend, scholars should pay careful attention to how these remakes as well as their marketing campaigns treat the source material. Even if the updated films and television shows are more self-aware, nostalgia-based marketing may allow adults to uncritically embrace and endorse the original content of works created in the 1980s that treat issues of race, gender, and sexuality in ways that are inconsistent with current cultural norms. She-Ra and the Princesses of Power argues against this embrace of nostalgic forms, even while using nostalgia to draw in a millennial audience.
Breathlessness limiting exertion in very old adults: findings from the Newcastle 85+ study
Authors: Johnson Miriam J , Pitel Lukas , Currow David C , Forbes Cynthia , Soyiri Ireneous , Robinson Louise
Published: September 2023

Introduction

Long-term breathlessness is more common with age. However, in the oldest old (>85 years), little is known about the prevalence, or impact of breathlessness. We estimated breathlessness limiting exertion prevalence and explored (i) associated characteristics; and (ii) whether breathlessness limiting exertion explains clinical and social/functional outcomes.

Methods

Health and socio-demographic characteristics were extracted from the Newcastle 85+ Study cohort. Phase 1 (baseline) and follow-up data (18 months, Phase 2; 36 months, Phase 3; 60 months, Phase 4 after baseline) were examined using descriptive statistics and cross-sectional regression models.

Results

Eight hundred seventeen participants provided baseline breathlessness data (38.2% men; mean 84.5 years; SD 0.4). The proportions with any limitation of exertion, or severe limitation by breathlessness were 23% (95% confidence intervals (CIs) 20–25%) and 9% (95%CIs 7–11%) at baseline; 20% (16–25%) and 5% (3–8%) at Phase 4. Having more co-morbidities (odds ratio (OR) 1.34, 1.18–1.54; P < 0.001), or self-reported respiratory (OR 1.88, 1.25–2.82; P = 0.003) or cardiovascular disease (OR 2.38, 1.58–3.58; P < 0.001) were associated with breathlessness limiting exertion. Breathlessness severely limiting exertion was associated with poorer self-rated health (OR 0.50, 029–0.86; P = 0.012), depression (beta-coefficient 0.11, P = 0.001), increased primary care contacts (beta-co-efficient 0.13, P = 0.001) and number of nights in hospital (OR 1.81; 1.02–3.20; P = 0.042).

Conclusions

Breathlessness limiting exertion appears to become less prevalent over time due to death or withdrawal of participants with cardio-respiratory illness. Breathlessness severely limiting exertion had a wide range of service utilisation and wellbeing impacts.
Predictors of persistent opioid use in non-cancer older adults: a retrospective cohort study
Authors: Beyene Kebede , Fahmy Hoda , Chan Amy Hai Yan , Tomlin Andrew , Cheung Gary
Published: September 2023

Background

Long-term opioid use and associated adverse outcomes have increased dramatically in recent years. Limited research is available on long-term opioid use in older adults.

Objective

We aimed to determine the incidence and predictors of long-term or persistent opioid use (POU) amongst opioid-naïve older adults without a cancer diagnosis.

Methods

This was a retrospective cohort study using five national administrative healthcare databases in New Zealand. We included all opioid-naïve older adults (≥65 years) who were initiated on opioid therapy between January 2013 and June 2018. The outcome of interest was POU, defined as having continuously filled ≥1 opioid prescription within 91–180 days after the index opioid prescription. Multivariable logistic regression was used to examine the predictors of POU.

Results

The final sample included 268,857 opioid-naïve older adults; of these, 5,849(2.2%) developed POU. Several predictors of POU were identified. The use of fentanyl (adjusted odds ratio (AOR) = 3.61; 95% confidence interval (CI) 2.63–4.95), slow-release opioids (AOR = 3.02; 95%CI 2.78–3.29), strong opioids (AOR = 2.03; 95%CI 1.55–2.65), Charlson Comorbidity Score ≥ 3 (AOR = 2.09; 95% CI 1.78–2.46), history of substance abuse (AOR = 1.52; 95%CI 1.35–1.72), living in most socioeconomically deprived areas (AOR = 1.40; 95%CI 1.27–1.54), and anti-epileptics (AOR = 2.07; 95%CI 1.89–2.26), non-opioid analgesics (AOR = 2.05; 95%CI 1.89–2.21), antipsychotics (AOR = 1.96; 95%CI 1.78–2.17) or antidepressants (AOR = 1.50; 95%CI 1.41–1.59) medication use were the strongest predictors of POU.

Conclusion

A significant proportion of patients developed POU, and several factors were associated with POU. The findings will enable healthcare providers and policymakers to target early interventions to prevent POU and related adverse events.
Protein glycosylation: bridging maternal–fetal crosstalk during embryo implantation
Authors: Sun Xinrui , Feng Ying , Ma Qianhong , Wang Yan , Ma Fang
Published: September 2023

Infertility is a challenging health problem that affects 8–15% of couples worldwide. Establishing pregnancy requires successful embryo implantation, but about 85% of unsuccessful pregnancies are due to embryo implantation failure or loss soon after. Factors crucial for successful implantation include invasive blastocysts, receptive endometrium, invasion of trophoblast cells, and regulation of immune tolerance at the maternal–fetal interface. Maternal–fetal crosstalk, which relies heavily on protein–protein interactions, is a critical factor in implantation that involves multiple cellular communication and molecular pathways. Glycosylation, a protein modification process, is closely related to cell growth, adhesion, transport, signal transduction, and recognition. Protein glycosylation plays a crucial role in maternal–fetal crosstalk and can be divided into N-glycosylation and O-glycosylation, which are often terminated by sialylation or fucosylation. This review article examines the role of protein glycosylation in maternal–fetal crosstalk based on two transcriptome datasets from the GEO database (GSE139087 and GSE113790) and existing research, particularly in the context of the mechanism of protein glycosylation and embryo implantation. Dysregulation of protein glycosylation can lead to adverse pregnancy outcomes, such as missed abortion and recurrent spontaneous abortion, underscoring the importance of a thorough understanding of protein glycosylation in the diagnosis and treatment of female reproductive disorders. This knowledge could have significant clinical implications, leading to the development of more effective diagnostic and therapeutic approaches for these conditions.
A noninvasive method for whole-genome skin methylome profiling
Authors: Banila Cristiana , Green Daniel , Katsanos Dimitris , Viana Joana , Osmaston Alice , Menendez Vazquez Angel , Lynch Magnus , Kaveh Shakiba
Published: September 2023

Background

Ageing, disease and malignant transformation of the skin are associated with changes in DNA methylation. So far, mostly invasive methodologies such as biopsies have been applied in collecting DNA methylation signatures. Tape stripping offers a noninvasive option for skin diagnostics. It enables the easy but robust capture of biologic material in large numbers of participants without the need for specialized medical personnel.

Objectives

To design and validate a methodology for noninvasive skin sample collection using tape stripping for subsequent DNA ­methylation analysis.

Methods

A total of 175 participants were recruited and provided tape-stripping samples from a sun-exposed area; 92 provided matched tape-stripping samples from a sun-protected area, and an additional 5 provided matched skin-shave biopsies from the same area. Using ­enzymatic conversion and whole-genome Illumina sequencing, we generated genome-wide DNA methylation profiles that were used to evaluate the feasibility of noninvasive data acquisition, to compare with established sampling approaches and to investigate biomarker identification for age and ultraviolet (UV) exposure.

Results

We found that tape-stripping samples showed strong concordance in their global DNA methylation landscapes to those of conventional invasive biopsies. Moreover, we showed sample reproducibility and consistent global methylation profiles in skin tape-stripping samples collected from different areas of the body. Using matched samples from sun-protected and sun-exposed areas of the body we were able to validate the capacity of our method to capture the effects of environmental changes and ageing in a cohort covering various ages, ethnicities and skin types. We found DNA methylation changes on the skin resulting from UV exposure and identified significant age-related hypermethylation of CpG islands, with a pronounced peak effect at 50–55 years of age, including methylation changes in well-described markers of ageing.

Conclusions

These data demonstrate the feasibility of using tape stripping combined with whole-genome sequencing as a noninvasive approach to measuring DNA methylation changes in the skin. In addition, they outline a viable experimental framework for the use of skin tape stripping, particularly when it is performed in large cohorts of patients to identify biomarkers of skin ageing, UV damage and, possibly, to track treatment response to therapeutic interventions.