bluuebunny/crossref_metadata_2025 huggingface dataset:
Industrial image anomaly detection based on multi Gaussian discriminant model and robust core set
Authors: Wei Ran , Li ZhengYang , Geng Lei , Wuken Muheiti , Liu YanBei
Published: August 2024

To address the issue of false positive (FP) detections in image anomaly detection caused by the loss of low-frequency features when dealing with high-dimensional feature distributions, we propose the multi-layer Gaussian discriminant anomaly detection model (MGAD). This model utilizes distance metrics based on multiple normal distributions to perform anomaly detection. By mining multi-layer feature combinations from normal samples and incorporating a Gaussian mixture model strategy for pixel-by-pixel probability density estimation, a weighting mechanism is designed to emphasize the role of low-frequency features in Gaussian space. This approach effectively models data collections that do not follow a single normal distribution as a mixture of several Gaussian distributions, thereby reducing false detections. Additionally, we propose a method for calculating the minimum Mahalanobis distance based on the estimation of the minimum covariance determinant. By identifying a subset with the smallest covariance matrix determinant, this method enhances the robust estimation of the data’s central position and spread, thereby reducing the impact of outliers. On the MVTec-AD dataset, MGAD demonstrates outstanding performance with an anomaly detection area under the receiver operating characteristic curve (AUROC) of 98.8%, the anomaly localization AUROC of 98.2%, and the per-class true negative rate for normal samples of 93.1%. Compared with the state-of-the-art models, MGAD improves the detection accuracy for normal samples by 3.6%, demonstrating the best performance among all models. These results highlight the model’s excellent capability in anomaly recognition and reduction of FPs.
A high-throughput statistical homogenization technique to convert realistic microstructures into idealized periodic unit cells
Authors: Foster S Caleb , Wilkerson Justin W
Published: August 2024

Metal alloys frequently contain distributions of second-phase particles that deleteriously affect the material behavior by acting as sites for void nucleation. These distributions are often extremely complex and processing can induce high levels of anisotropy. The particle length-scale precludes high-fidelity microstructure modeling in macroscale simulations, so computational homogenization methods are often employed. These, however, involve simplifying assumptions to make the problem tractable and many rely on periodic microstructures. Here we propose a methodology to bridge the gap between realistic microstructures composed of anisotropic, spatially varying second-phase void morphologies and idealized periodic microstructures with roughly equivalent mechanical responses. We create a high-throughput, parametric study to investigate 96 unique bridging methods. We apply our proposed solution to a rolled AZ31B magnesium alloy, for which we have a rich dataset of microstructure morphology and mechanical behavior. Our methodology converts a µ-CT scan of the realistic microstructure to idealized periodic unit cell microstructures that are specific to the loading orientation. We recreate the unit cells for each parameter set in a commercial finite element software, subject them to macroscopic uniaxial loading conditions, and compare our results to the datasets for the various loading orientations. We find that certain combinations of our parameters capture the overall stress–strain response, including anisotropy effects, with some degree of success. The effect of different parameter options are explored in detail and we find that excluding certain particle populations from the analysis can give improved results.
Machining mechanism of CoCrFeNiAlX high entropy alloys via ultrasonic elliptical vibration cutting
Authors: Zhang Ping , Wang Shunxiang , Sun Yajie , Zhang Jinlong , Yue Xiujie , Gao Yeran
Published: August 2024

This study investigates the micro-cutting mechanism of CoCrFeNiAl
X
high entropy alloys, focusing on the impact of amplitude, vibration frequency, cutting depth, and the Al element content. The mechanical response of the material is analyzed using simulation methods for both conventional cutting and ultrasonic elliptical vibration assisted cutting (UEVAC). The results show that under different vibration parameters and cutting depth, the cutting temperature produced by UEVAC is significantly higher than that of conventional cutting temperature. When the Y-axis amplitude is reduced from 90 μm to 30 μm, the cutting temperature is reduced by 50%. In addition, the cutting temperature is positively correlated with the Al content, and when the molar ratio is 20%, the cutting temperature is about 2.1 times that of 13%. While keeping the cutting parameters unchanged, the cutting force generated by UEVAC is significantly reduced compared to conventional cutting. It is worth noting that when the X-axis amplitude is 40 μm, the Y-axis amplitude is 90 μm, and the vibration frequency is 25 KHz, the cutting force of UEVAC is the smallest, which is only about 13% of the conventional cutting force. With the increase of the mole ratio of aluminum in the high entropy alloy, when the mole ratio of aluminum increases from 0% to 13%, the cutting force begins to decrease by about 33%. However, when the molar ratio increases from 13% to 20%, the cutting force increases by about 214%. On the surface of the workpiece (within the range of 0–3 μm from the machining surface), the residual stress generated by UEVAC is mainly manifested as compressive stress or tensile stress, which is significantly less than the residual stress generated by conventional cutting. The relation of residual compressive stress of workpiece under different aluminum content is Al1 > Al0.6 > Al0.
Completely degenerate equilibria of the Kuramoto model on networks
Authors: Sclosa Davide
Published: August 2024

Kuramoto Networks contain non-hyperbolic equilibria whose stability is sometimes difficult to determine. We consider the extreme case in which all Jacobian eigenvalues are zero. In this case linearizing the system at the equilibrium leads to a Jacobian matrix which is zero in every entry. We call these equilibria completely degenerate. We prove that they exist for certain intrinsic frequencies if and only if the underlying graph is bipartite, and that they do not exist for generic intrinsic frequencies. In the case of zero intrinsic frequencies, we prove that they exist if and only if the graph has an Euler circuit such that the number of steps between any two visits at the same vertex is a multiple of 4. The simplest example is the cycle graph with 4 vertices. We prove that graphs with this property exist for every number of vertices

N
⩾
6

and that they become asymptotically rare for N large. Regarding stability, we prove that for any choice of intrinsic frequencies, any coupling strength and any graph with at least one edge, completely degenerate equilibria are not Lyapunov stable. As a corollary, we obtain that stable equilibria in Kuramoto Networks must have at least one strictly negative eigenvalue.
Nondestructive evaluation of debonding in composites using air-coupled coda wave analysis and local defect resonance techniques
Authors: Li Zhiqiang , Jiao Jingpin , Zheng Xiangfeng , Hao Xiaojun , He Cunfu , Wu Bin
Published: August 2024

Low acoustic energy conversion efficiency is a major challenge for air-coupled ultrasonic technology. In the determination of the lift-off distance of air-coupled sensors, there is a balance between the acoustic energy attenuation and the difficulty of extracting defect information. In this study, an air-coupled local defect resonance (LDR) technique with coda wave analysis is proposed for the nondestructive evaluation of debonding in composites. A sensor consisting of 19 elements was used to simultaneously excite and receive ultrasonic waves. Air-coupled LDR experiments were conducted on the two types of composite structures. The effects of sensor lift-off distance and coda wave analysis on the performance of the LDR technique were investigated. It was found that the sensor lift-off distance and the coda wave analysis had a significant effect on the defect detection capability of the LDR technique. For composites, the optimal sensor lift-off distance was found to be between 3.5λ and 5.5λ, where λ is the wavelength. Compared to multiple reflection echoes, the coda waves are more suitable for identifying the damage in composites. The proposed non-contact ultrasonic technique effectively reduces the required incident acoustic energy and can be used for efficient detection of debonding in composites.
A soft bioinspired suction cup with tunable adhesion force using shape memory alloy
Authors: Zhou Weimian , Xu Chanchan , Chen Guisong , Wang Xiaojie
Published: August 2024

Suction cups has been widely utilized to grasp objects, but they typically encounter challenges with sealing failure and non-adjustable adhesion force. In this study, a bioinspired suction cup integrated with an shape memory alloy actuated module was proposed to solve these problems. The actuating performance under different input current was firstly investigated to ensure the effectiveness of the module. Then, inspired by the surface structures of the tree frog’s toe pad, the synthetic bioinspired suction cups with hexagonal microstructures at the rims were designed. The regular cup with soft and smooth rim was also fabricated for comparison study. Furthermore, the adhesion performance and surface adaptability of different two cups were studied in both dry and water conditions on substrates with various roughness levels. The results indicated that the proposed active bioinspired suction cup exhibited higher pull-off strength and better sealing on less rough substrates. The proposed bioinspired suction cup possessed the advantages of compactness and lightweight, thus demonstrating potential for integration into arrayed suction grippers.
Flat-band and diverse quasi-fermions in Pb10(PO4)6O4
Authors: He Qin , Ma Da-Shuai , Fu Botao , Li Xiao-Ping
Published: August 2024

Employing a combination of first-principles calculations and low-energy effective models, we present a comprehensive investigation on the electronic structure of Pb10(PO4)6O4, which exhibits remarkable quasi-one-dimensional topological flat-band around the Fermi level. These flat bands predominantly originate from the

p
x

/

p
y

orbitals of the oxygen molecules chain at the fully-occupied 4e Wyckoff positions and thus can be well-captured by a minimal four-band tight-binding model. Furthermore, the abundant crystal symmetry inherent in Pb10(PO4)6O4 provides an ideal platform for the emergence of various quasi-fermions characterized by different dispersion, degeneracy, and dimensionality. These include a 0D four-fold degenerate Dirac fermion exhibiting quadratic dispersion, a 1D quadratic/linear nodal-line fermion along symmetric k-paths, a 1D hourglass nodal-line (HNL) fermion associated with the Dirac fermion, and a 2D symmetry-enforced nodal surface located on the kz
= π plane. Moreover, when considering the weak ferromagnetic order, Pb10(PO4)6O4 transforms into a rare semi-half-metal, which is characterized by the presence of Dirac fermion and HNL fermion at the Fermi level for a single spin channel exhibiting 100

%

spin polarization. Our findings reveal the rarely coexistence of flat bands, diverse topological semimetal states and ferromagnetism in Pb10(PO4)6O4, which may provide valuable insights for further exploring the intriguing interplay between superconductivity and exotic electronic states.
Exploring the effect of strong electronic correlations in Seebeck Coefficient of the NdCoO3 compound : Using experimental and DFT+U approach
Authors: Pandey Abhishek , Pandey Sudhir K
Published: August 2024

The presence of complexity in the electronic structure of strongly correlated electron system NdCoO3 (NCO) have sparked interest in the investigation of its physical properties. Here, we study the Seebeck coefficient (α) of NCO by using the combined experimental and DFT+U based methods. The experimentally measured Seebeck coefficient is found to be ∼444 μ
V/K at 300 K, which decreases to 109.8 μ
V/K at 600 K. In order to understand the measured Seebeck coefficient, we have calculated the PDOS and band structure of the NCO. Furthermore, the calculated occupancy of 6.4 for Co 3d orbitals and presence of large unoccupied O 2p states indicate the covalent nature of the bonding. Apart from this, the maximum effective mass is found to be 36.75 (28.13) me for the spin-up (dn) channel in conduction band indicates the n-type behaviour of the compound in contrast to our experimentally observed p-type behaviour. While, the calculated Seebeck coefficient at the temperature-dependent chemical potential (μ) at 300 K shows the p-type behaviour of the compound. Fairly good agreement is seen between the calculated and measured values of α at U
ff
= 5.5 eV and U
dd
= 2.7 eV. The maximum power factor (PF) is found to be 47.6 (114.4)×1014
μW
K
−2cm−1
s
−1 at 1100 K, which corresponds to p (n)-type doping of ∼1.4 (0.7)×1021 cm−3. This study suggests the importance of strong on-site electron correlation in understanding the thermoelectric property of the compound
Influence of thermal radiation and magnetic field on convective transfer within an inclined square enclosure filled with Cu-water nanofluid
Authors: Elôrch M , Bendaraa A , Amlal W , Harchaoui M , Charafi M M
Published: August 2024

The present work investigates the effects of thermal radiation and magnetic field on the laminar convective transfer process on copper-based nanofluid within an inclined square enclosure. The studied configuration is a rigid-walled cavity subjected to a horizontal temperature gradient where the left wall is maintained at a hot temperature

T

h

and subjected to a magnetic field

B

0

.

In contrast, the right wall is kept at a cold temperature

T

c

.

The horizontal walls are adiabatic. The dimensionless governing equations are solved using the finite difference method and the UPWIND scheme to solve the convective terms. Formulated using the stream function, vorticity, and temperature. Effects on mean Nusselt numbers are investigated at different Rayleigh numbers

10

4

,

10

5

,

10

6

,

Hartmann numbers

H
A
=
0

t
o

100

,

tilt angles

γ
=
0
,
π
/
6
,

π
/
4

a
n
d

π
/
3

,

nanofluid volume fractions

0
%

≤

φ

≤

6
%

and different radiation parameters (

R
d
=
0
,

1
,

2
,

3

). The findings show that the HTR increased 3.6 times by augmenting the Ra from 104 to 106. Also, increasing the Ha number from 0 to 100 causes an 83.16% reduction in the HTR. Considering the radiation mode of heat transfer causes an increase in HTR. The average Nusselt values increase by 59.72% for the concentration of 6% while increasing the radiation parameter from 0 to 3. On the other hand, an increase in volume fraction leads to a deterioration in mean Nusselt numbers (Numean).
The effect of Casimir force on a diffraction grating in an optomechanical system
Authors: Rasul Khurram , Hussain Anwar , Asghar Sobia , Ziauddin  , Dong Shi-Hai
Published: August 2024

This study revisits an optomechanical cavity system to investigate how the Casimir force affects the manipulation of a diffraction grating. The proposed model consists of two mirrors, one of which is fixed while the other vibrates, and an external plate is used to generate the Casimir effect through the vibrating mirror. The Casimir effect has the potential to modify the properties of the output probe field (OPF), resulting in the phenomenon known as optomechanically induced transparency (OMIT), as reported in a previous study (Sci. Rep. 6, 27 102 (2016)). Interestingly, we observed that, when the Casimir effect exist, the maximum energy is transported to higher order. This theoretical realization of the diffraction grating could be feasibly tested in a physical experiment.
In situ preparation of MoS2@Fe3O4 by radiation method and its application in flame retardancy, mechanical properties, and friction properties of EVA composites
Authors: Xu Siyi , Li Danyi , Wang Wenrui , Lin Lin , Sun Ying , Li Jihao , Li Linfan
Published: August 2024

In recent years, there has been significant interest in using two-dimensional MoS2 to enhance flame retardancy, which has proven challenging. MoS2@Fe3O4 nanosheets were successfully synthesized via a one-step method called radiation reduction to boost MoS2’s flame retardant properties. Incorporating these MoS2@Fe3O4 nanocomposites notably improved the flame retardancy of ethylene vinyl acetate copolymer (EVA). Compared to pure EVA, EVA nanocomposites with 1 part of MoS2@Fe3O4 showed a 17.4% reduction in peak heat release rate, 40.4% decrease in total heat release, and 52.9% reduction in total smoke release, with scaly residue content improving from 0.4% to 12.6%. Additionally, MoS2@Fe3O4 incorporation enhanced the mechanical and friction properties of EVA composites, increasing tensile strength by 25.7% and elongation at break by 10.4% compared to pure EVA. This study presents an effective and simple method for producing modified MoS2 nanosheets that enhance flame retardancy, as well as mechanical and friction properties of EVA composites.
Nanosecond-pulse fiber laser mode-locked with iron phthalocyanine
Authors: S Wadi Nurul Izzah , Jusoh Zulzilawati , Muhammad Ahmad Razif , Ahmad B A , Salam Sameer
Published: August 2024

In this paper, we demonstrated a passively mode-locked erbium doped fiber laser (EDFL) using iron phthalocyanine (FePc) material as a saturable absorber (SA). The FePc-SA was prepared via a casting method, integrating FePc powder with polyvinyl alcohol to form FePc-PVA film. When implemented into the mode-locked EDFL cavity, the laser generated 356 ns pulses at a repetition rate of 969 kHz. Operating at a wavelength of 1559 nm, the laser achieved pulse energy of 6.04 nJ, output power of 5.85 mW, and peak power of 0.014 W under a maximum pump power of 128.92 mW. The laser exhibited remarkable stability, evidenced by a signal-to-noise ratio of 71.7 dB at the fundamental frequency. These results demonstrate that FePc material effectively serves as a mode-locker for generating nanosecond pulses.
Au–decorated TiO2 nanoparticle photoanode: synthesis, structural, optical properties and photoelectrochemical water splitting performance
Authors: Bui Ban V. , Nguyen Tien Dai , Hau Le Van Cong , Vu Thi Bich , Le Hoang V. , Le Thi Hong Phong , Thien Nguyen Duy , Nguyen Tien-Thanh
Published: August 2024

This study presents a novel approach to synthesizing Au-decorated TiO2 (Au/TiO2) nanoparticles (NP) using a spin-coating method, showcasing significant advancements in photoanode development. The resulting Au/TiO2 NPs exhibit well-defined crystallite structures comprising Au and TiO2 phases, featuring Au NP sizes ranging from 2.61 nm to 6.10 nm. Notably, the energy bandgap of these Au-decorated TiO2 NPs demonstrates a discernible redshift of 3.22–3.02 eV across various Au concentrations (1%–20%). Photoluminescence spectra reveal three distinct emission peaks at room temperature in the 400–550 nm wavelength range. The water-splitting activity of the Au/TiO2 NPs is investigated through the photoelectrochemical cell (PEC) employing an electrolyte solution with 1.0 M KH2PO4/K2HPO4 buffer. The results demonstrate a substantial photocurrent density of 0.23 mA.cm–2 at a potential of 1.6 V (versus RHE) and a photoconversion efficiency of 0.1% at 0.52 V (vs. RHE), respectively. This pioneering study underscores the potential of Au/TiO2 NP photoanodes as key components in advancing sustainable energy technologies, particularly in the realm of efficient PEC water-splitting applications.
Cauchy matrix approach for generalized semi-discrete lattice potential Korteweg–de Vries equations
Authors: Qiu Siming , Wang Ruodong , Yao Yuqin
Published: August 2024

Starting from a new scattering relation, we generate a generalized semi-discrete lattice potential Korteweg–de Vries(gsd-lpKdV) equation from a determining equation set(DES) and its Lax presentation. Further, the gsd-lpKdV equation with self-consistent sources(gsd-lpKdVSCS) is worked out by introducing two discrete variables to the plane wave factors. Specially, explicit formulae for kink solitons, Jordan-block solutions and diagonal-Jordan-block solutions of gsd-lpKdVSCS are obtained based on the Cauchy matrix approach. Moreover, We illustrate the dynamics of one-kink soliton, two-kink soliton, high order Jordan-block solutions and the diagonal-Jordan-block solution.
Microstructure and high-temperature oxidation resistance of in-situ synthesized Ti-Al-Si composite coating by laser cladding
Authors: Wang Yueyi , Hao Xuanhong , Liu Yaxia , Yang Chen , Liu Hongxi , Zhang Xiaowei
Published: August 2024

According to the in situ reaction mechanism of Ti, Al, Si mixed powders and the Ti-Al-Si ternary phase diagram, two kinds of alloy systems with an atomic ratio of Ti: Al: Si=41:41:18 and Ti: Al: Si=35:35:30 was designed. The Ti-Al-Si composite coatings were in situ synthesized by laser cladding on Ti6Al4V titanium alloy (TC4) surface. The microstructure and phase composition of composite coating were characterized by x-ray diffraction (XRD) and scanning electron microscopy (SEM). The microhardness and corrosion resistance of coating were investigated by microhardness tester and electrochemical workstation. The high-temperature oxidation resistance and anti-oxidation mechanism of coating at 800 °C × 24 h × 5 times cyclic oxidation was analyzed by oxidation mass gain and oxidation kinetics curves. The results show that the Ti-Al-Si composite coating has a good metallurgical bonding with titanium alloy substrate. The coating is mainly composed of Ti5Si3, Ti7Al5Si12, Ti3Al, TiAl and TiAl3 phases. The average microhardness of the two kinds of coating is 853.3 HV0.2 and 795.2 HV0.2, 2.37 times and 2.21 times that of the substrate, respectively. Compared with titanium alloy substrate, the corrosion resistance of the coating in artificial seawater has been improved significantly, and the coating with an atomic ratio of Ti: Al: Si=41:41:18 is better than the coating with an atomic ratio of Ti: Al: Si=35:35:30. The oxidation kinetics curves at 800 °C × 24 h × 5 times cyclic oxidation exhibit that the oxidation resistance of Ti: Al: Si=41:41:18 coating increase by 12.5 times. The oxide layer on titanium alloy surface is loose and composed of rod-like TiO2 and cluster islands Al2O3. However, on the surface of cladding composite coating, a uniform, dense and long rod-like oxide layer with a thickness of about 8 μm is formed. The oxide layer on cladding composite coating surface is mainly composed of TiO2, Al2O3 and SiO2. The in situ synthesized Ti-Al-Si laser cladding composite coating plays a positive role in improving the high-temperature oxidation resistance of titanium alloy.
Optimizing solar power generation forecasting in smart grids: a hybrid convolutional neural network -autoencoder long short-term memory approach
Authors: Zafar Ahsan , Che Yanbo , Sehnan Moeed , Afzal Usama , D Algarni Abeer , Elmannai Hela
Published: August 2024

Incorporating zero-carbon emission sources of energy into the electric grid is essential to meet the growing energy needs in public and industrial sectors. Smart grids, with their cutting-edge sensing and communication technologies, provide an effective approach to integrating renewable energy resources and managing power systems efficiently. Improving solar energy efficiency remains a challenge within smart grid infrastructures. Nonetheless, recent progress in artificial intelligence (AI) techniques presents promising opportunities to improve energy production control and management. In this study, initially, we employed two different Machine learning (ML) models: Recurrent Neural Network (RNN) and Long Short Term Memory (LSTM), to forecast solar power plant parameters. The analysis revealed that the LSTM model performed better than RNN in terms of Mean Absolute Percentage Error (MAPE), Mean Absolute Error (MAE), and Mean Squared Error (MSE). Following a review of the LSTM model’s graphical results, it was further enhanced by combining Autoencoder with LSTM, creating the Autoencoder LSTM (AELSTM) model. Next, a new hybrid model was introduced: Convolutional Neural Network-Autoencoder Long Short-Term Memory (HCAELSTM), designed to boost prediction accuracy. These models were trained on a one-year real-time solar power plant dataset for training and performance assessment. Ultimately, the hybrid HCAELSTM model surpassed the AELSTM model in terms of MAPE, MAE, and MSE. It excelled in MAPE scores for Daily Power Production, Peak Grid Power Production, and Solar Radiance, achieving low scores of 1.175, 2.116, and 1.592 respectively, demonstrating superior accuracy. The study underscores the importance of AI and ML, in particular, the hybrid model HCAELSTM, in enhancing the smart grid’s ability to integrate renewable energy sources. The hybrid model excels at accurately forecasting key measurements, improving solar power generation efficiency within the smart grid system which also plays a key role in the broader shift toward the fourth energy revolution.
The role of mobility in epidemics near criticality
Authors: Nettuno Beatrice , Toffenetti Davide , Metzl Christoph , Weigand Linus , Raßhofer Florian , Swiderski Richard , Frey Erwin
Published: August 2024

The general epidemic process (GEP), also known as susceptible-infected-recovered model, provides a minimal model of how an epidemic spreads within a population of susceptible individuals who acquire permanent immunization upon recovery. This model exhibits a second-order absorbing state phase transition, commonly studied assuming immobile healthy individuals. We investigate the impact of mobility on the scaling properties of disease spreading near the extinction threshold by introducing two generalizations of GEP, where the mobility of susceptible and recovered individuals is examined independently. In both cases, including mobility violates GEP’s rapidity reversal symmetry and alters the number of absorbing states. The critical dynamics of the models are analyzed through a perturbative renormalization group (RG) approach and large-scale stochastic simulations using a Gillespie algorithm. The RG analysis predicts both models to belong to the same novel universality class describing the critical dynamics of epidemic spreading when the infected individuals interact with a diffusive species and gain immunization upon recovery. At the associated RG fixed point, the immobile species decouples from the dynamics of the infected species, dominated by the coupling with the diffusive species. Numerical simulations in two dimensions affirm our RG results by identifying the same set of critical exponents for both models. Violation of the rapidity reversal symmetry is confirmed by breaking the associated hyperscaling relation. Our study underscores the significance of mobility in shaping population spreading dynamics near the extinction threshold.
Variational aspect and kinetic theory of locally conformal dynamics
Authors: Esen Oğul , Gezici Ayten , Gümral Hasan
Published: August 2024

We present the locally conformal generalization of the Euler–Lagrange equations. We determine the dual space of the LCS Hamiltonian vector fields. Within this dual space, we formulate the Lie–Poisson equation that governs the kinetic motion of Hamiltonian systems in the context of local conformality. By expressing the Lie–Poisson dynamics in terms of density functions, we derive locally conformal Vlasov dynamics. In addition, we outline a geometric pathway that connects LCS Hamiltonian particle motion to locally conformal kinetic motion.
On the Lundgren hierarchy of helically symmetric turbulence
Authors: Stegmayer V , Görtz S , Akbari S , Oberlack M
Published: August 2024

This paper analyzes the reduction of the infinite Lundgren–Monin–Novikov (LMN) hierarchy of probability density functions (PDFs) in the statistical theory of helically symmetric turbulence. Lundgren’s hierarchy is considered a complete model, i.e. fully describes the joint multi-point statistic of turbulence though at the expense of dealing with an infinite set of integro-differential equations. The LMN hierarchy and its respective side-conditions are transformed to helical coordinates and thus are dimesionally reduced. In the course of development, a number of key questions were solved, namely in particular the transformation of PDFs and sample space velocities into orthonormal coordinate systems. In a validity check it is shown, that the mean momentum equations derived from the helical LMN hierarchy via statistical moment integration are identical to the mean momentum equations derived by direct ensemble averaging the Navier–Stokes equation, in helically symmetric form. Finally, we derive the equation for the characteristic function equivalent to the PDF equation in a helically symmetric frame, which allows to generate arbitrary

n

t
h

-order statistical moments by simple differentiation.
Antioxidant response of Calendula officinalis L. assisted synthesized zinc oxide nanoparticles
Authors: Tiwari Ajay Kumar , Jha Saket , Tripathi Sharad Kumar , Awasthi Ram Raseele , Bhardwaj Abhishek Kumar , Singh Abhimanyu Kumar , Dikshit Anupam
Published: August 2024

The over-production of free radicals in the body causes oxidant damage in the body. Currently, zinc oxide nanoparticles (ZnO NPs) are gaining attention of most scientists because of their excellent physical, chemical, and biological properties. In this work, the ZnO NPs were synthesized using the petal extract of C. officinalis L. An absorbance spectrum of the synthesized ZnO NPs was recorded using an ultraviolet-visible (UV–Vis) spectrophotometer. The absorbance band around 368 nm confirms the formation of ZnO NPs. The transmission electron microscopy (TEM) analysis clearly shows that the most of the ZnO NPs are spherical in shape with average particle size ∼ 16 nm. The field emission scanning electron microscope (FE-SEM) result demonstrates the spherical morphology with large agglomeration of the particles. The energy-dispersive x-ray spectroscopy (EDS) result confirms the presence of Zn in the synthesized NPs’. The x-ray diffraction (XRD) peaks represent the crystalline structure of the ZnO NPs with average particle size ∼ 27.22 nm. Fourier transform infra-red (FT-IR) spectrum of synthesized ZnO NPs was recorded in the range of 4000-500 cm−1. The ester and carboxylic groups were found at 1017 cm−1, 952 cm−1, 688 cm−1, 609 cm−1, and 514 cm−1 due to the presence of Zn-O band stretch in the FT-IR spectrum. Further synthesized material was evaluated by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay to evaluate its antioxidant activity. It showed that ZnO NPs exhibited significant antioxidant activity through scavenging DPPH free radicals. Thus, it could be seen that the synthesis of naturally occurring plant product ZnO NPs acts as an alternative chemical antioxidant. Hence, the herbal synthesized ZnO NPs are proven to be a potent antioxidant agent and can be used in several medicinal applications.
A deterministic design approach of tilt integral derivative controller for integer and fractional-order system with time delay
Authors: Dakua Biresh Kumar , Pati Bibhuti Bhusan
Published: August 2024

A tilt integral derivative (TID) controller modifies the proportional integral derivative (PID) controller in the fractional domain. It converts the proportional gain as a function of frequency and is thereby capable of achieving optimal system response. The usual practice for the parameter estimation of the TID controller is by minimization of the error-based objective functions using optimization techniques. Although precise results can be achieved, these nature-inspired algorithms are stochastic and hence produce different solutions during different iterations. Therefore, a comparative statistical study is usually necessary to validate the best possible result. This study shows a deterministic analytical procedure for the paramssseter estimation of TID controllers. The magnitude and phase angle criteria, along with the frequency-domain loop shaping specifications, are used for the explicit evaluation of the TID parameters. Because of its model-independent nature, this tuning strategy can be used for a variety of integral and nonintegral order systems with different plant structures. In this article, the authenticity of the applied procedure is demonstrated through suitable numerical examples. The complexity of the design problem is enhanced by using it for both integer and non-integer (fractional) order plus time-delay systems. Further, the robustness of the control system in the presence of a TID controller was examined under the influence of external parameters and input reference changes. Simulation studies validate the supremacy of TID controllers over PID controllers in terms of reference tracking and disturbance rejection capabilities.
Normalizing flows as an enhanced sampling method for atomistic supercooled liquids
Authors: Jung Gerhard , Biroli Giulio , Berthier Ludovic
Published: August 2024

Normalizing flows can transform a simple prior probability distribution into a more complex target distribution. Here, we evaluate the ability and efficiency of generative machine learning methods to sample the Boltzmann distribution of an atomistic model for glass-forming liquids. This is a notoriously difficult task, as it amounts to ergodically exploring the complex free energy landscape of a disordered and frustrated many-body system. We optimize a normalizing flow model to successfully transform high-temperature configurations of a dense liquid into low-temperature ones, near the glass transition. We perform a detailed comparative analysis with established enhanced sampling techniques developed in the physics literature to assess and rank the performance of normalizing flows against state-of-the-art algorithms. We demonstrate that machine learning methods are very promising, showing a large speedup over conventional molecular dynamics. Normalizing flows show performances comparable to parallel tempering and population annealing, while still falling far behind the swap Monte Carlo algorithm. Our study highlights the potential of generative machine learning models in scientific computing for complex systems, but also points to some of its current limitations and the need for further improvement.
UV electromagnetic irradiation sensing by GQDs sensitized ZnO/GaN heterostructure for wearable dosimetry
Authors: Goswami Lalit , Prajapat Pukhraj , Vashishtha Pargam , Gupta Govind
Published: August 2024

Sensing of Ultraviolet (UV) Electromagnetic Irradiations (EIs) for wearable dosimetry is promulgated universally by reserving their place in precise calibration for the controlled exposure of UV-EIs for the betterment of humankind. In other words, the controlled exposure of incident optical power density (OPD) of UV-EIs found advantageous and numerous noble healthcare applications such as beta-endorphin molecule (provide feel-good factor to the brain) level augmentation, adequate vitamin D (physical strength) level formation, in skin treatment like eczema and dermatitis, sensing important biomolecules like Uric Acid (responsible for critical disease related with kidney and heart). Moreover, the controlled exposure of OPDs also significantly impacts UV disinfection technologies, which provide a defensive shield against critical respiratory syndrome coronavirus 2 (SARS-CoV-2), which belongs to the COVID-19 pandemic. Therefore, by understanding the importance of limited exposure to these vital UV-EIs, the present study showcased the GQDs-sensitized ZnO/GaN heterostructured UV sensor utilized to explore the impact of UV-EIs OPDs on their performance. This study helps to develop and utilize the UV sensor-based wearable dosimetry for in-house diagnostics of critical healthcare parameters. This report also divulged an interesting core mechanism (band bending, tunneling through narrowed hole injection under increased negative bias) involved in affecting the performance of the UV-EIs sensor by a function of growing OPDs with the help of a suitable band diagram. The impact of increasing OPDs on fabricated UV-EIs sensors can be well understood by the fact that, by varying the OPDs up to ∼550%, the Gain (G), responsivity (R), external quantum efficiency (EQE) and noise equivalent power (NEP) significantly increases up to (156.7 to 332.4) ∼300%, (118 A W−1 to 3200 A W−1) 2700%, (∼870% to 12 × 103%) 1400% and (1.3 pWHz−1/2 to 50 fWHz−1/2) 10,000% respectively at an applied bias of −6 V. Furthermore, the time-correlated transient photoresponse is also dramatically improved with increasing OPDs, wherein the increment in rise and decay time is estimated as (159 ms to 7.86 ms) ∼2000% and (68.7 ms to 12.4 ms) ∼500%, respectively.
Extreme Overvalued Beliefs
Authors: Rahman Tahir , Abugel Jeffrey
Published: August 2024

An extreme overvalued belief is one that is shared by others in a person’s cultural, religious, or subcultural group. The belief is often relished, amplified, and defended by the possessor of the belief and should be differentiated from an obsession or a delusion. The belief grows more dominant over time, more refined and more resistant to challenge. The individual has an intense emotional commitment to the belief and may carry out violent behavior in its service. Carl Wernicke first described overvalued ideas. Paul R. McHugh invoked overvalued ideas as a thought shared by others in a society or culture and capable of provoking dominant behaviors in its service. Dr. Hagop Akiskal stated that the definitive test (of a delusion vs. overvalued idea) is whether an unusual belief is shared by members of the patient’s subculture (overvalued ideas are fanatically maintained notions, such as superiority of one sex, nation, or race).
Lethal Fixations
Authors: Rahman Tahir , Abugel Jeffrey
Published: August 2024

The DSM-5-TR definition of delusions reads: “fixed beliefs that are not amenable to change in light of conflicting evidence.” German psychiatrist Kurt Schneider provided a description of what he prioritized as the “first rank” symptoms of schizophrenia (thought insertion, thought withdrawal, thought broadcasting, passivity experiences, and a running commentary of voices). The cases of Daniel McNaughton (who shot Edward Drummond instead of Prime Minister Robert Peel), Dante Soiu (stalking of Gwyneth Paltrow), Salvador Ramos (Uvalde), Charles Whitman (obsessions), and Andrea Yates (infanticide) are discussed. The work of David Veale, George Winokur, J. Richard Ciccone, Reid Meloy, and Theo Manschreck on delusional disorder, overvalued ideas, obsessions, and cognitive-affective drivers are compared and contrasted. Cases of monomania and catathymic homicide are also discussed in the context of target attacks.
Extreme Overvalued Beliefs
Authors: Rahman Tahir , Abugel Jeffrey
Published: August 2024

Just as a delusion, or rarely an obsession, can lead to violence, so can an extreme overvalued belief. Such a belief is often binary, simplistic, and absolute; and it is often more difficult to disprove than a delusion. The forensic cases of Anders Breivik, Dylann Roof, Timothy McVeigh (Oklahoma City bombing), Fort Hood attack (Army Major Malik Hasan), and Cesar Sayoc (mail bombs) are discussed, as well as implications for the insanity defense and death penalty. Carl Wernicke argued that it was possible for any belief to become overvalued, and that an affect‐laden (very emotional) experience often triggers or reinforces the belief. For instance, a depressed or grieving individual, feeling slighted by the government or by society, might convert to a new religion or begin exploring new ideologies. Harvard psychiatrist Oliver Freudenreich stated that those with overvalued ideas (fanatics) may be secretly regarded as heroes, but might not jeopardize themselves.
Digital Subcultures
Authors: Rahman Tahir , Abugel Jeffrey
Published: August 2024

The internet and other digital forms of media are powerful tools that enable the development of shared beliefs in subcultures. Such subcultures contain shared values, beliefs, language, symbols, rituals, emojis, norms and abbreviations. Social media and gaming platforms also have unique syntax, vocabulary, and writing style which can be difficult for outsiders to fully appreciate. A digital subculture of dissatisfaction, racism, fantasy, and identification and the glorification of violent behavior produce a well-known contagion or “copycat” effect in terrorism—culminating in extreme overvalued beliefs. Subculutres come in “waves” or epochs of terrorism as political currents change. The cases of Payton Gendron, Dylann Roof, Brenton Tarrant, Nikolas Cruz, Salvador Ramos, and Patrick Crusius are discussed. They committed some of the deadliest massacres in recent American history.
Morally Reasoned Attacks
Authors: Rahman Tahir , Abugel Jeffrey
Published: August 2024

Max Wertheimer introduced the term phi phenomenon (perception of apparent movement). He described the optical illusion of apparent movements when two optical stimuli are presented with alternating high frequency. A group of laws or principles of Gestalt psychology were introduced in 1923. These laws included: proximity, similarity, closure, symmetry, and common fate. Among other notions, these laws posited that objects are perceptually grouped together by the brain to form patterns that are regular, simple, and orderly. The internet has done much the same with beliefs called internet cognitive isoforms, defined here as a piece of information learned online that is used to connect the “cognitive dots.” Jumping to conclusions and binary bias are features of human cognition. Psychologists Solomon Asch and Daniel Kahneman have pioneered the work on cognitive short cuts. The development of radicalization, extreme overvalued beliefs, and terrorism (targeted attacks) are discussed in the chapter.
Suicide
Authors: Rahman Tahir , Abugel Jeffrey
Published: August 2024

Consensus among terrorism experts (e.g., Jerold Post) is that there is a “collective identity” which best explains it. As an example, they stress social psychology and group dynamics to emphasize the “normality” and absence of individual psychopathology in suicide bombers. This chapter discusses seppuku, kamikaze suicidal pilots, the 9/11 attacks, U.S. mass shooters, Palestinian suicide bombers, and teen suicides as having epochs—each determined by the context of a unique, shared, and often time-limited social climate. The rate of teen suicide has increased over the past decade and it is now the second leading cause of death for teens and young adults in the United States. This chapter discusses Yukio Mishima, kamikaze pilot Kenichro Oonuki, Osama bin Laden, 9/11, Sharia law, and Muhammad Atta in the context of subcultures and collective identities.
Extreme Overvalued Beliefs in Literature
Authors: Rahman Tahir , Abugel Jeffrey
Published: August 2024

Carl Wernicke first described overvalued ideas in Dostoyevsky’s novel Crime and Punishment. He discussed Rodion Raskolnokov as having a moral grievance in which he justifies killing an elderly pawn broker. Raskolnikov relishes the fantasy of become an extraordinary man, like Napoleon, with special and grandiose talents to offer the world. The story of the Devils of Loudon was an epidemic comparable to what Carl Jung called the “induced collective psychoses of the twentieth century.” Yukio Mishima, Romeo and Juliet, as well as other cases of romantic relationships leading to suicide are also discussed.
Epilogue
Authors: Rahman Tahir , Abugel Jeffrey
Published: August 2024

Karl Jaspers further elaborated on overvalued ideas. Paul McHugh at Johns Hopkins notes that Jaspers knew that mental distress could emerge as consequences of some conflict between an individual’s wishes and actual life circumstances. One approach used to prevent eating disorders that may be of value for targeted violence prevention is an intervention known as the “Body Project.” It is based on the social psychological principle of cognitive dissonance: the contemporaneous experience of conflicting attitudes, beliefs, or behaviors in a person. Utilizing cognitive dissonance involving moral schemas could be readily developed into primary prevention (“cognitive inoculation”) strategies. Similar to the Body Project, the participant would be better equipped to resist moral schemas and progression to an extreme overvalued belief. Education regarding internet cognitive isoforms could provide tools to counter misinformation or disinformation.
Spaces of Cultural Negotiation
Authors: Berruezo-Sánchez Diana
Published: August 2024

This chapter examines literary, visual, and historical sources that are testament to black Africans playing music and singing in houses, streets, taverns, and confraternities. It explores three broad categories of spaces—streets, courts, and ships—as sites of cultural negotiation for black musicians and performers. The agency of black musicians and dancers and the limitations placed upon them are further illuminated by considering two very different black figures: Joan Domingo Moreno, a black man in mid-sixteenth-century Valencia; and Francisco the Meneses, a black man who paid for his manumission with money earned from dancing. Both stories confirm that city streets in particular were a productive space of cultural and social negotiation for black people in early modern Spain.
Paneth cell differentiation associated with neoadjuvant therapy in esophageal adenocarcinoma
Authors: Ramineni Madhurya , Findeis Sarah K , Ye Jiqing , Hao Yansheng
Published: August 2024

Objectives

Paneth cells and Paneth cell metaplasia are well-known in pathology as foundational components in the gastrointestinal system. When within malignant cells (Paneth cell differentiation [PCD]), however, the function and significance of these cells is less well understood. Here, we present findings from the first study focused on PCD in postneoadjuvant esophageal adenocarcinoma (EAC) resection specimens.

Methods

Patients with EAC treated with neoadjuvant chemoradioation and followed by esophagectomy between 2012 and 2018 in our institution were retrospectively evaluated. A tissue microarray was constructed, and special and immunohistochemical stains were performed.

Results

A total of 64 cases were collected, of which 8 had PCD, as highlighted by periodic acid–Schiff with diastase staining. Adenocarcinomas with PCD were more commonly seen in patients 60 to 70 years of age and typically had a poorly differentiated morphology, observationally fewer stromal mucinous changes, and less lymph node metastasis. β-catenin activation induced by neoadjuvant therapy was more frequent in the PCD-positive cases. Patients with PCD-positive disease had low programmed cell death 1 ligand 1 levels, no positive or equivocal ERBB2 (HER2) expression, and low CD8-positive T-cell infiltration; they were also mismatch repair proficient. Patients with PCD-positive disease showed a survival pattern inferior to that of patients with PCD-negative disease.

Conclusions

When induced by neoadjuvant therapy in EAC, PCD is associated with high β-catenin activation, less expression of targetable biomarkers, and a potentially worse clinical prognosis.