bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding disorder in monolayer graphene devices with gate-defined superlattices
Authors: Kammarchedu Vinay , Butler Derrick , Rashid Asmaul Smitha , Ebrahimi Aida , Kayyalha Morteza
Published: September 2024

Engineering superlattices (SLs)—which are spatially periodic potential landscapes for electrons—is an emerging approach for the realization of exotic properties, including superconductivity and correlated insulators, in two-dimensional materials. While moiré SL engineering has been a popular approach, nanopatterning is an attractive alternative offering control over the pattern and wavelength of the SL. However, the disorder arising in the system due to imperfect nanopatterning is seldom studied. Here, by creating a square lattice of nanoholes in the SiO2 dielectric layer using nanolithography, we study the SL potential and the disorder formed in hBN-graphene-hBN heterostructures. Specifically, we observe that while electrical transport shows distinct SL satellite peaks, the disorder of the device is significantly higher than graphene devices without any SL. We use finite-element simulations combined with a resistor network model to calculate the effects of this disorder on the transport properties of graphene. We consider three types of disorder: nanohole size variations, adjacent nanohole mergers, and nanohole vacancies. Comparing our experimental results with the model, we find that the disorder primarily originates from nanohole size variations rather than nanohole mergers in square SLs. We further confirm the validity of our model by comparing the results with quantum transport simulations. Our findings highlight the applicability of our simple framework to predict and engineer disorder in patterned SLs, specifically correlating variations in the resultant SL patterns to the observed disorder. Our combined experimental and theoretical results could serve as a valuable guide for optimizing nanofabrication processes to engineer disorder in nanopatterned SLs.
Three-dimensional free-standing heterostructures out of MoS2 and rGO with infused PDMS towards electromechanical pressure sensing
Authors: Solayman Abdullah , Li Baosong , Abu Al-Rub Rashid , Liao Kin
Published: September 2024

The behavior of two-dimensional (2D) materials constructed as three-dimensional structures is studied to bring such materials one step closer to the real-life application. Lattices structures of gyroid triply periodic minimal surface (TPMS) were fabricated out of 2D materials, namely, molybdenum disulfide (MoS2), and reduced graphene oxide (rGO), forming for the first time free-standing MoS2 (FSM) lattice and free-standing hetero-structural lattice of MoS2 and rGO (FSH) out of TPMS. These 2D materials were also integrated with polydimethylsiloxane (PDMS) elastomer, forming FSM/PDMS and FSH/PDMS composites. Mechanical characterization, including compression and cyclic tests, were conducted on FSM, FSH, and the composites. Additionally, electromechanical characterization was conducted to evaluate the sensing potential of these structures. It is worth noting that the elastic modulus of the 10 unit-cells with either FSM or FSH was higher than the other lattices of the same type. FSH tends to have a higher modulus at 1504.4 kPa in the 10 unit-cells. This modulus is even higher at 3 MPa when PDMS is added to the FSH lattice. Due to the brittle fracture, FSM or FSH lattices follow the layer-by-layer failure mechanism. Samples with PDMS are more stable towards such cyclic tests without noticeable failures or a decrease in elastic modulus. Finally, the 10 unit-cell lattices of FSH/PDMS composite have the highest conductivity at 2.5 mA, and a comparable sensitivity at 0.365 kPa−1 over the range of 0–100 kPa.
Shape optimization of a non-uniform piezoelectric bending beam for human knee energy harvester
Authors: Liao Haisu , Wu Tsunho , Gao Gang , Wu Xinyu , Gao Fei
Published: September 2024

Scavenging energy from the human body to provide a sustainable source for electronic devices has gained significant attention. Recently, scientists have focused on harnessing biomechanical energy from human motion. This study was dedicated to developing and optimizing a non-uniform piezoelectric bending beam-based human knee energy harvester. The bimorph non-uniform piezoelectric bending beam consisted of a non-uniform carbon fiber substrate and piezoelectric macro fiber composites. Compared to the uniform piezoelectric bending beam, the non-uniform piezoelectric beam can optimize the shape to improve the average strain, thus improving the energy harvesting efficiency. In this study, eight shape functions, including ellipse, sin, tanh, exponential function, parabola, trigonometric line, and bell curves, were investigated and optimized. The bell curve bending beam was selected and fabricated due to its good performance. Then, a benchmark platform was developed to test the deflection curve and reaction force when the nonuniform bending beam was compressed. Finally, to validate the design, experimental testing on three subjects was conducted when they were equipped with the harvester and walked on a treadmill. Testing results indicated that the non-uniform bending beam-based energy harvester can improve the energy harvesting efficiency by 28.57% compared to the uniform beam-based energy harvester. The output power can reach 18.94 mW when walking at 7.0 km h−1.
Engineering quasi-bound states in the continuum in asymmetric waveguide gratings
Authors: Yezekyan Torgom , Boroviks Sergejs , Martin Olivier J F , Bozhevolnyi Sergey I
Published: September 2024

The occurrence of quasi-bound states in the continuum (qBIC) in all-dielectric asymmetric grating waveguide couplers with different degrees of asymmetry under normal light incidence is analysed from the viewpoint of identifying the most promising configuration for realizing the highest quality (Q) factor under the condition of utmost efficiency (i.e. total extinction). Considering asymmetric gratings produced by altering every Nth ridge of a conventional (symmetric) grating coupler, we analyse different regimes corresponding to the interplay between diffractive coupling to waveguide modes and band gap effects caused by the Bragg reflection of waveguide modes. The symmetric and double- and triple-period asymmetric grating couplers are considered in detail for the same unperturbed two-mode waveguide and the grating coupler parameters that ensure the occurrence of total transmission extinction at the same wavelengths. It is found that the highest Q is expected for the double-period asymmetric grating, a feature that we explain by the circumstance that the first-order distributed Bragg resonator (DBR) is realized for this configuration while, for other configurations, the second-order DBR comes into play. Experiments conducted at telecom wavelengths for all three cases using thin-film Al2O3-on-MgF2 waveguides and Ge diffraction gratings exhibit the transmission spectra in qualitative agreement with numerical simulations. Since the occurrence of considered qBIC can be analytically predicted, the results obtained may serve as reliable guidelines for intelligent engineering of asymmetric grating waveguide couplers enabling highly resonant, linear and nonlinear, electromagnetic interactions.
Bayesian estimation for the power rayleigh lifetime model with application under a unified hybrid censoring scheme
Authors: M Hasaballah Mustafa , Samson Balogun Oluwafemi , Bakr M E
Published: September 2024

This study presents a comprehensive analysis of Bayesian estimation techniques for the parameters of the power Rayleigh (PR) distribution under a unified hybrid censoring scheme (UHCS). The research employs both Bayesian and Frequentist approaches, utilizing maximum likelihood estimation (MLE) alongside Bayesian estimates derived through Markov Chain Monte Carlo (MCMC) methods. The study incorporates symmetric and asymmetric loss functions, specifically general entropy (GE), linear expoential (LINEX), and squared error (SE), to evaluate the performance of the estimators. A Monte Carlo simulation study is conducted to assess the effectiveness of the proposed methods, revealing that Bayesian estimators generally outperform Frequentist estimators in terms of mean squared error (MSE). Additionally, the paper includes a real-world application involving ball bearing lifetimes, demonstrating the practical utility of the proposed estimation techniques. The findings indicate that both point and interval estimates exhibit strong properties for parameter estimation, with Bayesian estimates being particularly favored for their accuracy and reliability.
ZnO thin films co-doped with III-valence metals and halogens: theory and experiment
Authors: Colibaba G V , Rusnac D , Fedorov V , Koltsov M A , Volobujeva O , Grzibovskis R , Vembris A , Spalatu N
Published: September 2024

The efficiency of metal-halogen co-doping of ZnO thin films deposited by DC magnetron sputtering of ceramic targets has been studied theoretically and experimentally. The influence of deposition temperature (300 − 900 K range), ZnX2 pressure (10−10−1 atm), Me2O3 dopant concentration (10−3 − 10 mol %), and Zn pressure (10−14 − 10−6 atm) on the composition of ZnO − Me2O3 − ZnX2 − Zn (Me = Al, Ga, In; X = F, Cl, Br, I) systems has been analyzed theoretically. The surface migration velocity of oxides and halides is also estimated for a wide temperature range. According to the calculation results, the optimal deposition conditions have been recommended. ZnO thin films co-doped with Al+Cl, Ga+Cl, Ga+Br, Ga+I, and In+Cl were deposited using ZnO:Me:X ceramic targets sintered by chemical vapor transport based on halides. The influence of the stoichiometric deviation of ceramic targets, the concentration of halogens, and metal impurities on thin films’ electrical, structural, compositional, and optical properties has been investigated. It is shown that Ga+Cl+Zn co-doping is the most promising. This co-doping increases both the structural perfection of films (electron mobility) and doping efficiency by Ga (charge carrier concentration), reducing the resistivity of thin films by two times compared to the use of classical ZnO:Ga ceramic targets. The optimal stoichiometric deviation of ZnO:Me:X ceramics targets, corresponding to the highest electron mobility and figure of merit of thin films, has been recommended.
Estimating observable-specific phase biases of GEO satellites from regional CORS to analyze its contribution in PPP ambiguity resolution
Authors: Chen Kun , Ye Shirong , Xia Pengfei , Sha Zhimin , Luo Hao , Liu Jianhui , Jiang Junfei
Published: September 2024

Achieving high-precision positioning and fast convergence has been the objective of Precision Point Positioning (PPP), which is restricted by the integer ambiguity resolution (AR). Recently, the emergence of observable specific code/phase bias (OSB) has gratefully alleviated this phenomenon. However, for the BeiDou Satellite Navigation System (BDS), only MEO/IGSO satellites are applied in BDS PPP-AR, while GEO satellites are generally ignored. It will largely limit the utilization in China or Asia-Pacific region, influencing both the convergence time and the positioning accuracy. To investigate the feasibility of applying GEO satellites for AR, the phase OSB of GEO satellites is estimated through the raw observations in this research. Based on the observations data from regional network in China region, the characteristics of BDS mixed-constellation OSBs are analyzed, and PPP-AR with different processing strategies in both static and kinematic mode are performed. The results indicate that the phase OSBs were relatively stable and the percentage of the estimated residuals for B1I/B3I signals within ±0.15/0.25 cycles were over 95/99% and 92/97% for IGSO and MEO satellites, while GEO satellites were slightly poor, with 89 and 96%, respectively. The average positioning accuracy of static PPP-AR containing GEO satellites was 0.55, 0.56 and 1.43 cm in the east, north and up directions, with improvements of 14.06, 3.44 and 9.48% respect to fixed solutions without GEO satellites. For kinematic mode, when the ambiguity of GEO satellites was solved, the convergence time and the average time to first fix were considerably reduced to 25.51 and 27.12 min, exhibiting the improvement of 26.16 and 14.80% compared to fixed solutions without GEO satellites, respectively. This further demonstrated the considerable applications potential of GEO satellites to regional users.
Thermal dark matter with low-temperature reheating
Authors: Bernal Nicolás , Deka Kuldeep , Losada Marta
Published: September 2024

We explore the production of thermal dark matter (DM) candidates (WIMPs, SIMPs, ELDERs and Cannibals) during cosmic reheating. Assuming a general parametrization for the scaling of the inflaton energy density and the standard model (SM) temperature, we study the requirements for kinetic and chemical DM freeze-out in a model-independent way. For each of the mechanisms, up to two solutions that fit the entire observed DM relic density exist, for a given reheating scenario and DM mass. As an example, we assume a simple particle physics model in which DM interacts with itself and with SM through contact interactions. We find that low-temperature reheating can accommodate a wider range of couplings and larger masses than those permitted in the usual instantaneous high-temperature reheating. This results in DM solutions for WIMPs reaching masses as high as 1014 GeV, whereas for SIMPs and ELDERs, we can reach masses of 1013 GeV. Interestingly, current experimental data already constrain the enlarged parameter space of these models with low-reheating temperatures. Next-generation experiments could further probe these scenarios.
Plasma impact on black hole shadows and gravitational weak lensing in the Einstein–Maxwell-scalar theory
Authors: Alloqulov Mirzabek , Shaymatov Sanjar , Jawad Abdul , Zaripov Oripjon
Published: September 2024

In this paper, we investigate the optical properties of a non-rotating charged black hole (BH) in the Einstein–Maxwell-scalar (EMS) theory, together with a plasma medium. We first consider the photon sphere and shadow radius under the impact of the plasma medium existing in the environment surrounding the BH in the EMS theory. We show that the radius of the photon sphere and the BH shadow decrease under the influence of the parameter β. We further study gravitational weak lensing in detail by adapting general methods and derive the light ray’s deflection angle around the BH together with the plasma environment. It is found that for uniform plasma, the deflection angle increases with the rise of the plasma parameter, whereas it decreases with the increase of the plasma parameter for non-uniform plasma. Besides, we also study the magnification of image brightness.
The effective potential for conformal factor and GL(4) symmetry
Authors: Oda Ichiro
Published: September 2024

We revisit the issue of whether the effective potential for the conformal factor of the metric, which is generated by quantized matter fields, possesses a non-vanishing vacuum expectation value (VEV) or not. We prove that the effective potential has a vanishing vacuum expectation value on the basis of a global GL(4) symmetry. We also account for why there seems to be two different effective potentials for the conformal factor in a theory, one of which gives rise to a vanishing VEV for the conformal factor, whereas the other has a non-vanishing VEV.
Thermal stress concentration points and stress mutations in nano-multilayer film structures
Authors: Zheng Ying , Wang Zhi You , Song Qianju , Yi Zao , Cheng Shubo , Ma Can , Tang Chaojun , Zeng Qingdong , Ahmad Sohail
Published: September 2024

In the multilayer film-substrate system, thermal stress concentration and stress mutations cause film buckling, delamination and cracking, leading to device failure. In this paper, we investigated a multilayer film system composed of a substrate and three film layers. The thermal stress distribution inside the structure was calculated by the finite element method, revealing significant thermal stress differences between the layers. This is mainly due to the mismatch of the coefficient of thermal expansion between materials. Different materials respond differently to changes in external temperature, leading to compression between layers. There are obvious thermal stress concentration points at the corners of the base layer and the transition layer, which is due to the sudden change of the shape at the geometric section of the structure, resulting in a sudden increase in local stress. To address this issue, we chamfered the substrate and added an intermediate layer between the substrate and the transition layer to assess whether these modifications could reduce or eliminate the thermal stress concentration points and extend the service life of the multilayer structure. The results indicate that chamfering and adding the intermediate layer effectively reduce stress discontinuities and mitigate thermal stress concentration points, thereby improving interlayer bonding strength.
Dark energy effects on surface gravitational redshift and Keplerian frequency of neutron stars
Authors: He Jia-Jing , Xu Yan , Wang Yi-Bo , Huang Xiu-Lin , Hu Xing-Xing , Shen Yu-Fu
Published: September 2024

Research on the properties of neutron stars with dark energy is a particularly interesting yet unresolved problem in astrophysics. We analyze the influence of dark energy on the equation of state, the maximum mass, the surface gravitational redshift and the Keplerian frequency for the traditional neutron star and the hyperon star matter within the relativistic mean field theory, using the GM1 and TM1 parameter sets by considering the two flavor symmetries of SU(6) and SU(3) combined with the observations of PSR J1614-2230, PSR J0348+0432, PSR J0030+0451, RX J0720.4-3125, and 1E 1207.4-5209. It is found that the existence of dark energy leads to the softened equations of the state of the traditional neutron star and the hyperon star. The radius of a fixed-mass traditional neutron star (or hyperon star) with dark energy becomes smaller, which leads to increased compactness. The existence of dark energy can also enhance the surface gravitational redshift and the Keplerian frequency of traditional neutron stars and hyperon stars. The growth of the Keplerian frequency may cause the spin rate to speed up, which may provide a possible way to understand and explain the pulsar glitch phenomenon. Specifically, we infer that the mass and the surface gravitational redshift of PSR J1748-2446ad without dark energy for the GM1 (TM1) parameter set are 1.141 M
⊙ (1.309 M
⊙) and 0.095 (0.105), respectively. The corresponding values for the GM1 (TM1) parameter set are 0.901 M
⊙ (1.072M
⊙) and 0.079 (0.091) if PSR J1748-2446ad contains dark energy with α = 0.05. PSR J1748-2446ad may be a low-mass pulsar with a lower surface gravitational redshift under our selected models.
The Impact of Nova Outbursts on the Chemical Abundance of the Interstellar Medium
Authors: He Guoli , Zhu Chunhua , Lü Guoliang , Li Lin , Guo Sufen , Liu Helei , Gao Jun
Published: September 2024

Nova outbursts are the results of thermonuclear runaways, which occur when sufficient material accretes on the surfaces of white dwarfs (WDs). Using the MESA code, we construct a detailed grid for carbon-oxygen and oxygen-neon-magnesium novae. By employing population synthesis methods, we conduct a statistical analysis of the distribution of novae in the Milky Way. In our models, on average, a typical nova system may undergo about 8000 eruptions and the Galactic nova rate is ∼130 yr−1. The C, N, and O elements in nova ejecta are strongly affected by the mixing degree between WD core and accreted material. Our results show that the average value of 12C/13C in nova ejecta is about an order of magnitude lower than that on the surface of a red giant, that for 16O/17O is about 5 times lower, and that for 14N/15N is about 1.5 times lower. The annual yields of 13C , 15N, and 17O from nova ejection are larger than those from AGB stars. This indicates that compared to a red giant, nova eruptions are a more important source of the odd-numbered nuclear elements of 13C , 15N, and 17O in the Galactic interstellar medium.
PD-ARnet: a deep learning approach for Parkinson’s disease diagnosis from resting-state fMRI
Authors: Li Guangyao , Song Yalin , Liang Mingyang , Yu Junyang , Zhai Rui
Published: September 2024

Objective. The clinical diagnosis of Parkinson’s disease (PD) relying on medical history, clinical symptoms, and signs is subjective and lacks sensitivity. Resting-state fMRI (rs-fMRI) has been demonstrated to be an effective biomarker for diagnosing PD. Approach. This study proposes a deep learning approach for the automatic diagnosis of PD using rs-fMRI, named PD-ARnet. Specifically, PD-ARnet utilizes Amplitude of Low Frequency Fluctuations and Regional Homogeneity extracted from rs-fMRI as inputs. The inputs are then processed through a developed dual-branch 3D feature extractor to perform advanced feature extraction. During this process, a Correlation-Driven weighting module is applied to capture complementary information from both features. Subsequently, the Attention-Enhanced fusion module is developed to effectively merge two types of features, and the fused features are input into a fully connected layer for automatic diagnosis classification. Main results. Using 145 samples from the PPMI dataset to evaluate the detection performance of PD-ARnet, the results indicated an average classification accuracy of 91.6% (95% confidence interval [CI]: 90.9%, 92.4%), precision of 94.7% (95% CI: 94.2%, 95.1%), recall of 86.2% (95% CI: 84.9%, 87.4%), F1 score of 90.2% (95% CI: 89.3%, 91.1%), and AUC of 92.8% (95% CI: 91.1%, 95.0%). Significance. The proposed method has the potential to become a clinical auxiliary diagnostic tool for PD, reducing subjectivity in the diagnostic process, and enhancing diagnostic efficiency and consistency.
Integrating spatial and temporal features for enhanced artifact removal in multi-channel EEG recordings
Authors: Yin Jin , Liu Aiping , Wang Lanlan , Qian Ruobing , Chen Xun
Published: September 2024

Objective. Various artifacts in electroencephalography (EEG) are a big hurdle to prevent brain–computer interfaces from real-life usage. Recently, deep learning-based EEG denoising methods have shown excellent performance. However, existing deep network designs inadequately leverage inter-channel relationships in processing multi-channel EEG signals. Typically, most methods process multi-channel signals in a channel-by-channel way. Considering the correlations among EEG channels during the same brain activity, this paper proposes utilizing channel relationships to enhance denoising performance. Approach. We explicitly model the inter-channel relationships using the self-attention mechanism, hypothesizing that these correlations can support and improve the denoising process. Specifically, we introduce a novel denoising network, named spatial-temporal fusion network (STFNet), which integrates stacked multi-dimension feature extractor to explicitly capture both temporal dependencies and spatial relationships. Main results. The proposed network exhibits superior denoising performance, with a 24.27% reduction in relative root mean squared error compared to other methods on a public benchmark. STFNet proves effective in cross-dataset denoising and downstream classification tasks, improving accuracy by 1.40%, while also offering fast processing on CPU. Significance. The experimental results demonstrate the importance of integrating spatial and temporal characteristics. The computational efficiency of STFNet makes it suitable for real-time applications and a potential tool for deployment in realistic environments.
1

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f

α

noise in the Robin Hood model
Authors: Singh Abha , Chhimpa Rahul , Yadav Avinash Chand
Published: September 2024

We consider the Robin Hood dynamics, a one-dimensional extremal self-organized critical model that describes the low-temperature creep phenomenon. One of the key quantities is the time evolution of the state variable (force noise). To understand the temporal correlations, we compute the power spectra of the local force fluctuations and apply finite-size scaling to get scaling functions and critical exponents. We find a signature of the

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noise for the local force with a nontrivial value of the spectral exponent

0
<
α
<
2

. We also examine temporal fluctuations in the position of the extremal site and a local activity signal. We present results for different local interaction rules of the model.
An Intrusion Detection Model Based on a Residual Memory Convolutional Neural Network with Attention Mechanism
Authors: Liu Yuankai , Guo Feng , Zhao Qian , Wu Chuankun
Published: September 2024

As the utilization of IoT devices becomes more widespread, the variety of attacks targeting these devices is also increasing. Traditional intrusion detection systems in IoT environments often struggle to effectively recognize the diverse types of attacks. Therefore, this study proposes a Residual Memory Convolutional Neural Network (RMCNN) model incorporating an attention mechanism, aimed at improving the accuracy and efficiency of multi-class attack detection in IoT environments. The model begins by extracting spatial features from traffic data through Convolutional Neural Network (CNN) layers, and then captures dynamic changes in time series data using Gated Recurrent Unit (GRU). Subsequently, a multi-head attention mechanism is employed to reinforce focus on critical information. Finally, the outputs from the GRU are combined with those from the multi-head attention mechanism via residual connections, enhancing the model’s learning capabilities and improving the recognition accuracy of various attack types. Verified through experiments on the CICIOT2023 dataset, the model achieved an F1 score of 97.29%, indicating significant improvements in the detection performance of multi-class attacks and confirming its applicability and effectiveness in the field of IoT security.
A Registration Method Based on Planar Features Between BIM Model and Point Cloud
Authors: Wu Qiwen , Zhao Xi
Published: September 2024

In the digitization process of the construction industry, it is frequently necessary to use BIM as a digital model carrier, and the registration between BIM and point cloud is a crucial step in BIM applications. Most existing 3D registration methods, such as the ICP algorithm, are capable of aligning point clouds. However, these classical methods are subject to the influence of numerous points contained within the point cloud, relying heavily on point-to-point correlations. Consequently, it is challenging to extend these algorithms to register with other forms of spatial information, such as BIM models, beyond the point cloud. Considering that planes are basic geometric elements in building BIM models, this paper proposes a novel method for aligning BIM models with point clouds by matching planar features. The method extracts planes from point clouds using an enhanced region growing algorithm, directly parsing the planar geometric information from BIM in IFC format. After completing the matching of plane groups, the optimal solution is calculated using a weighted least squares method. The experimental results indicate that the proposed method can achieve successful registration between the BIM model and point cloud, with a lower RMSE of 5.73mm compared to the registration method using RANSAC+ICP on the same dataset.
Research and design of low-noise cooling fan for fuel cell vehicle
Authors: Zhu Jiale , Xu Guoqiang , You Yanghong , He Youwei
Published: September 2024

The main noise source of fuel cell vehicles comes from the cooling vehicle, which has the characteristics of high voltage and large air volume. However, the large air volume makes the fan noise level significantly increase, reaching about 70dB. Even if the car adopts a variety of physical noise reduction methods, the noise level inside the car is still high, seriously affecting the passenger ride experience. In recent years, related research combined with bionic technology to improve the fan blade by designing a new shape structure, so that it has similar characteristics to some organisms to achieve the purpose of noise reduction. In this paper, ANSYS-CFX software is used to simulate the fan efficiency and noise level under different blade numbers, predict its performance, and optimize its structure.
Research and optimization of heat transfer characteristics of heat pipe-coupled phase change energy storage system
Authors: Zhang Renping , Zhou Zuxiang
Published: September 2024

Heat pipe coupled Latent Heat Thermal Energy Storage (LHTES) is a commonly used technique for improving heat storage, due to its advantages such as heat conduction, isothermal, and uniform temperature. Adding fins to the heat pipe can enhance energy storage efficiency and system performance. Although previous research has looked into how heat pipe layouts affect LHTES, there is still a dearth of research on fin geometry optimization for boosted heat transfer. In this work, we used ANSYS Fluent to simulate the consequence of fin placement upon the heating capacity of a Phase Change Material (PCM) based LHTES system. Through an in-depth analysis of the heat transfer mechanisms, in an effort to quicken the PCM’s solidification process, we adjusted the fins’ length and spacing. The LHTES system’s overall solidification time was greatly shortened by the optimized model, going from 18800 seconds to 8500 seconds, achieving a 54.79% enhancement in thermal transfer efficiency.
Development of large-volume 130TeO2 bolometers for the CROSS 2β decay search experiment
Authors: Avignone F.T. , Barabash A.S. , Berest V. , Bergé L. , Calvo-Mozota J.M. , Carniti P. , Chapellier M. , Dafinei I. , Danevich F.A. , Dumoulin L. , Ferella F. , Ferri F. , Gallas A. , Giuliani A. , Gotti C. , Gras P. , Ianni A. , Imbert L. , Khalife H. , Kobychev V.V. , Konovalov S.I. , Loaiza P. , de Marcillac P. , Marnieros S. , Marrache-Kikuchi C.A. , Martinez M. , Nisi S. , Nones C. , Olivieri E. , Ortiz de Solórzano A. , Peinaud Y. , Pessina G. , Poda D.V. , Rosier Ph. , Scarpaci J.A. , Tretyak V.I. , Umatov V.I. , Zarytskyy M.M. , Zolotarova A.
Published: September 2024

We report on the development of thermal detectors based on
large-size tellurium dioxide crystals
(45 × 45 × 45 mm), containing tellurium enriched in
130Te to about 91%, for the CROSS double-beta decay
experiment. A powder used for the crystals growth was additionally
purified by the directional solidification method, resulting in the
reduction of the concentration of impurities by a factor 10, to a
few ppm of the total concentration of residual elements (the main
impurity is Fe). The purest part of the ingot (the first
∼ 200 mm, about 80% of the total length of the cylindrical
part of the ingot) was determined by scanning segregation profiles
of impurities and used for the 130TeO2 powder production
with no evidence of re-contamination. The crystal growth was
verified with precursors produced from a powder with natural Te
isotopic composition, and two small-size
(20 × 20 × 10 mm) samples were tested at a sea-level
laboratory showing high bolometric and spectrometric performance
together with acceptable 210Po content (below 10 mBq/kg). This
growth method was then applied for the production of six large cubic
130TeO2 crystals and 4 of them were taken randomly to be
characterized at the Canfranc underground laboratory, in the
CROSS-dedicated low-background cryogenic facility. Two
130TeO2 samples were coated with a thin,
𝒪(100 nm), metal film in form of Al layer (on 4 sides)
or AlPd grid (on a single side) to investigate the possibility to
tag surface events by pulse-shape discrimination. Similarly to the
small natural precursors, large-volume 130TeO2 bolometers
show high performance and even better internal purity (^210Po
activity ∼ 1 mBq/kg, while activities of 228Th and
226Ra are below 0.01 mBq/kg), satisfying requirements for the
CROSS and, potentially, next-generation experiments.
Isotopic labeling evidence shows faster carbon release from microbial residues than plant litter
Authors: Zhu Jingjing , Cai Yuhua , Wu Fuzhong , Zhang Jinyu , Zhang Xinying , Ni Xiangyin
Published: September 2024

Carbon (C) release from plant and microbial residues is a primary pathway of energy flow from photosynthetic and metabolic biomass to carbon dioxide (CO2) in terrestrial ecosystems. Traditional view show that microbial residue C is more resistant to decompose than plant litter because their smaller particle sizes could be preferentially occluded in microaggregates with less microbial accessibility. However, we still lack a quantitative assessment (i.e. isotopic C labeling) to isolate the progressive release of C fractions from both plant and microbial residues. Here we used a global data set of 117 decomposition experiments that traced the 13C or 14C release of isotopically labeled plant and microbial residues to estimate the C release rates and turnover times by using a first-order exponential kinetics model. The average C release rates of crop, grass and tree litter were 7.78, 3.79 and 2.11 yr−1, which were significantly lower than microbial residues (13.07 yr−1). Although C release rates of both plant and microbial residues were positively correlated with site temperature, the mean turnover time of microbial residues was 2–6 times lower than plant litter. We suggest that a constraint in microbial and plant residues leads to a predictable pattern of C release during terrestrial decomposition, which could be included in Earth system models.
Change in the sustainability of regional agricultural systems: based on an emergy decomposition analysis
Authors: Song Fei , Wu Haoyu , Sun Zihan , Bai Junbo , Su Fangli , Xu Deshen , Cao Chenchen , Li Haifu , Song Shuang , Liu Yi
Published: September 2024

In the context of rapid population growth and limited arable land resources, the agricultural system has to provide enough food in a sustainable way. Regional agricultural systems have good consistency in agricultural practices, management decisions, social economy, and climate, which is of great significance in ensuring food security. In this study, emergy analysis and the logarithmic mean divisia index method were integrated to construct an evaluation framework from the dimensions of socio-economic environment, resource environment, climate environment, and ecological environment. Then we evaluated and analyzed the changes in agricultural system sustainability from 1990 to 2019 in the mainstream of Liaohe River Basin, a typical agricultural basin in China. The results showed that the Emergy sustainability index (ESI) decreased from 0.17 to 0.14, and factors Δ Pt/Gt
(social and economic development level), Δ G/I (agricultural economic benefits), and Δ Gt/G (economic structure) from the socio-economic environment dimension had the greatest impact on changes in ESI. Moreover, society and economy affected the factors in the resource environmental dimensions through the allocation of policies and resources, which in turn directly affected ESI. The influence of factors from the climatic environment and ecological environment weakens as the ability to manage agricultural systems increases. The research provided a reference for the planning and management of sustaining agricultural systems at a regional scale.
Synthesis reveals heterogeneous changes in the metabolism and emission of greenhouse gases of drying rivers
Authors: Sepp Margot , González-Trujillo Juan David , Marcé Rafael , Sabater Sergi
Published: September 2024

More than half of the world’s rivers experience occasional, seasonal, or permanent drying, and this may increase because of climate change. Drying, i.e. severe reduction in water flow even leading to streambed desiccation, can have a profound impact on the available aquatic habitat, biodiversity, and functions of rivers. Yet, to date, it is unclear whether similar drying events in comparable climate zones result in similar changes in ecosystem processes, such as river metabolism or greenhouse gas (GHG) emissions. Here, we synthesise the detected effects of drying on gross primary production (GPP) and ecosystem respiration (ER), as well as on the emissions of GHGs (CO2, CH4, and N2O) in rivers and streams. We examined the current available scientific literature detailing the impact of drying on these variables when measured either in the field or in the laboratory. We extracted data from 30 studies analysing GPP and ER responses, and data on GHG emissions from another 35 studies. Then, we conducted a meta-analysis to determine whether the magnitude and direction of the effects varied across the systems and climate zones studied, or according to the type (natural or human-induced) and severity of drying. In general, drying enhanced GPP (under low flows) and CH4 emissions, and decreased CO2 and N2O emissions. The hydrological phases throughout streambed drying (low water flow, isolated pools, or desiccation) had differential effects on metabolism and GHG emissions. The effects of drying were generally more severe when it induced desiccation, rather than just periods of low flow. Desiccation strongly reduced GPP, likely because of the die-off of algae, while its negative effect on ER was smaller. Greater decrease in GPP than in ER under desiccation would lead to increase in CO2 emissions; our results showed accordingly that desiccation increased CO2 emissions. Furthermore, the magnitude and direction of the effects varied depending on the study type. Experimental studies conducted in micro- and mesocosms demonstrated greater effects than field studies, thus the extrapolation of results from these to real conditions should be done with caution. Overall, the effects’ direction was inconsistent across climate zones, except for the Mediterranean climate zone, where drying was showing a negative effect on both metabolism and GHG emissions. Our synthesis may contribute to identifying the worldwide trends and patterns of drying on riverine functions associated to global change impacts on river and stream ecosystems.
Special Department India (Sonderreferat Indien) of the German Foreign Ministry
Authors: Roy Baijayanti
Published: September 2024

This chapter examines the epistemology of ‘politically useful’ knowledge concerning India, produced at the Special Department India (Sonderreferat Indien; SRI) of the German Foreign Ministry, through an interface between certain wartime objectives of Nazi Germany and the diasporic Indian anti-colonialism represented by the militant nationalist Subhas Chandra Bose who lived in Berlin between 1941 and 1943. This chapter examines two projects undertaken by the SRI, which illustrate the collusion between knowledge production on India, Bose’s concerns, and the demands of Nazi politics: (a) fortnightly reports on the current developments in India, and (b) a series of German books on modern India. While the reports were to serve as guidelines for the German press in its coverage of Indian events, the books were manifestations of the Nazi government`s tactical expression of sympathy for Indian anti-colonialism as well as informal guidebooks for shaping German propaganda concerning India. These projects were pursued mainly under two functionaries of the SRI: the Indologist Ludwig Alsdorf and the former Social Democrat and trade unionist Franz Josef Furtwängler. Another aim of this chapter is to inspect the role of the Indian anti-colonialists involved in these two projects. While a few of them were allowed to present an occasional report, others were denied the privileged status of knowledge providers for the Nazi government. The chapter contends that the interracial relationships and the process of knowledge production, as well as the utilizable knowledge discourses were deeply influenced by certain racialized assumptions and political prejudices which overlapped between German Indological scholarship and Nazi Weltanschauung.
Introduction
Authors: Shoemaker David
Published: September 2024

This chapter motivates the book with the general motto assumed by most responsibility theorists that “to be a responsible agent is to be an apt candidate for responses like blame and praise.” The first worry about this motto is that blame doesn’t seem to have a unitary nature. We blame each other in multiple ways for multiple reasons. The second worry is that there’s been hardly any work on praise; indeed, most philosophers have assumed that, once we get clear on the nature of blame, then praise will simply be its positive counterpart. But as it turns out, there are many reasons to think not; indeed, there seem to be numerous asymmetries between them. What’s needed, therefore, is a systematic investigation into the nature of both blame and praise, as well as the nature of blameworthiness and praiseworthiness, and the remainder of the introduction lays out the plan of attack.
Competition and Cooperation in Video Games
Authors: Lei Y. Skylar , Liu Hanjie , Ewoldsen David R.
Published: September 2024

Competition and cooperation are both essential to human evolution and social interactions. Humans naturally compete with each other over resources, yet humans also evolved to engage in cooperation to enhance survivability. Competition and cooperation as complex social interactions can be observed in many contexts. Video games are a vivid illustration of how people compete, cooperate, or compete and cooperate at the same time with each other. The history of video games reflects how people are naturally inclined to build environments and construct rules to facilitate competition. Meanwhile, video game play also demonstrates how people are drawn to cooperation with each other whenever the need arises. Competition and cooperation have been examined and discussed in many fields of study. Social interdependence theory provides a clear theoretical framework for understanding competitive or cooperative situations. Competition in video game settings can be seen as a range of negative interdependence between players, while cooperation is a range of positive interdependence. With video game settings becoming more complex and connecting more players virtually, games that facilitate both competition and cooperation between teams of players emerged and became prevalent. Research has previously demonstrated that cooperation in video games tends to result in increased positive outcomes for players compared to competition. However, in games where competition and cooperation between human players coexist, newly observed phenomena, namely toxic behaviors and antisocial interactions, contradict previous findings. It is evident that we still have a lot to learn about human competition and cooperation in video games. With video game technologies improving and diversifying rapidly, more research is needed to understand players’ psychological processes and behaviors in video game settings.
Difficulty and Challenge in Video Games
Authors: Schmierbach Michael , Tan Ryan , Sherrick Brett
Published: September 2024

Video game difficulty relates to several other key concepts in the study of games. Defined here as the player perception of the barriers that stand in the way of completing game tasks, difficulty is a perceptual variable that reflects both designed features and unintentional barriers as well as player skill. Employing this definition can help better elucidate difficulty as a player-focused experience that varies between players, whereas other terms, including challenge and task, can be used to describe design features. Difficulty is related to other concepts, such as demands, flow, and competency, and empirical research has not always effectively differentiated these ideas. Demands represent player understanding of intended challenges. They may be understood differently by different players but are not defined in terms of player mastery. Flow includes a central idea of skill–challenge balance but is also suggested to involve other experiences. Competency may have a non-linear relationship with difficulty, but further research is needed. Measurement of difficulty is still developing, and existing scales that reflect other concepts need further modification or replacement to directly capture difficulty as defined here. Scholarship shows that difficulty is influenced by game features, contextual factors, and individual differences. Aspects such as the complexity of tasks, pace of play, or precision of necessary actions can all amplify the experience of difficulty, as can the consequences for failure. Unusual or unfamiliar controls can amplify difficulty, as can social pressures. Prior research shows that difficulty and challenge influence psychological responses, learning, enjoyment, and other outcomes. Optimal difficulty should involve a moderate level of the variable, but evidence is mixed about where that optimal state exists and often suggests a simple, negative relationship between difficulty and positive experiences. Some advocates have suggested that games encourage players to embrace difficulty in education and other tasks, potentially increasing learning, but evidence is mixed. Specific traits that would make players more tolerant of difficulty remain to be identified. Improved standardization in vocabulary and study design when studying difficulty would be fruitful.
Constitutions and the Rule of Law in Asia
Authors: De Visser Maartje , Ramraj Victor V. , Thiruvengadam Arun
Published: September 2024

In the modern world, formal constitutions are ubiquitous as the legal foundation of the state, standing at the apex of the legal order. As they emerged in a North Atlantic context, constitutional law and the ideal of constitutionalism came to be associated with a liberal model of government in which the state, composed of its leaders and public officials, was limited by law. This model of a constrained government became encapsulated in the ideal of “rule of law”—distinguishing between autocratic systems that were ruled by “men,” on the one hand, and systems in which political leaders were constrained by law, on the other hand. In this model, the courts typically play a critical institutional role in keeping state power within constitutional boundaries. Although this “liberal” model of constitutionalism and the rule of law continue to dominate legal and political thought, the proliferation of postcolonial legal and political regimes, and competing understandings of government and the role of the state, have challenged the dominant liberal understanding of constitutions and the rule of law. Many of these challenges come from Asia, which encompasses a stunning variety of political regimes that shape the environment in which constitutionalism and the ideal of the rule of law acquire meaning. This makes Asia an ideal site from which to explore the contested notions of constitutions, constitutionalism, and the rule of law as powerful explanatory tools and, in some cases, important normative correctives to the liberal model.