bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantum mechanical analysis of a single contact superconducting interferometer at low temperatures
Authors: Grinberg Ya. S.
Published: December 2024

The behavior of a single-contact superconducting interferometer at low temperatures, when its energy of zero point quantum vibrations ℏ(LC)−1/2 is comparable to the thermal energy kT, is studied. Hysteresis-free and hysteretic regimes of operation of the interferometer are examined. It is shown that taking into account quantum corrections leads to effects which, probably, can be observed experimentally.
Low-dimensional electronic systems on a liquid helium surface (Review)
Authors: Monarkha Yu. P. , Shikin V. B.
Published: December 2024

The results of theoretical and experimental investigations of the properties of two-dimensional electronic systems on a liquid helium surface are reviewed. Such well-known problems as the description of the electronic states above a flat liquid-vapor interface and the interaction with surface excitations of helium are examined briefly. The collective effects are described in greater detail: two-dimensional plasma waves, Wigner crystallization, crystallization of electronic systems with screened interaction, instability of a charged helium surface, and macroscopic structures. New, interesting systems on a liquid helium surface, accessible to experimental study, are also described.
Peculiarities in electronic properties of molybdenum ternary sulfides PbMo6S8
Authors: Shevchenko A. D. , Aleksandrov O. V. , Drozdova S. V. , Kalyuzhnaya G. A. , Kiseleva K. V. , Primachenko V. F. , Shevchuk N. V , Yachmenev V. E.
Published: December 2024

The influence of the technological parameters of its synthesis on the superconducting and structural properties of PbMo6S8 has been investigated. For the first time lattice instability near 80 °K has been detected from x-ray structural studies carried out on PbMo6S8 in the temperature range 4.2–300 °K. The resistivity ρ(Tc − 300 °K), magnetic susceptibility χ(Tc − 300 °K), and specific heat Cp (2–300 °K) of the PbMo6S8 system were measured as a function of the temperature. Joint analysis of the experimental results and the data in the literature on inelastic neutron scattering at 4.2 and 300 °K enabled us to make the first quantitative calculations of the phonon specific heat and its anharmonic component, the temperature dependence of the electronic specific heat coefficient γH(T), the band density of electronic states at the Fermi level NBS(EF), and the electron-phonon interaction constant λ(T). It has been found that the ρ(T), γH(T) and λ(T) curves display anomalies near temperatures ≈80°K, at which lattice instability occurs, and the high-field superconductivity in PbMo6S8 is a consequence of the large value of NBS(EF).
Determination of the microcontact function of the electron–phonon interaction in sodium and potassium by the pseudopotential method
Authors: Zhernov A. P. , Naidyuk Yu. G. , Yanson I. K. , Kulagina T. N.
Published: December 2024

The electron-phonon interaction function in Na and K is calculated from first principles using only the pseudopotential for the electron-phonon interaction. The calculations for Na are done for two lattices (b.c.c. and f.c.c.) and also for K with changes in the pseudopotential. Good agreement is observed between the calculated functions and the experimental data.
Contribution of optical vibrations to the low-temperature specific heat of layered crystals
Authors: Syrkin E. S. , Feodos’ev S. B.
Published: December 2024

The contribution of optical vibrations to the specific heat as the crystal anisotropy changes is analyzed by the method of Jacobi matrices. It is shown that low-frequency optical modes existing in strongly anisotropic crystals yield a substantial contribution to the low-temperature thermodynamic characteristics of these compounds.
Anomalous pressure dependence of the Curie point of nickel fluosilicate
Authors: Galkin A. A. , Vitebskii I. M. , D’yakonov V. P. , Fita I. M. , Tsintsadze G. A.
Published: December 2024

The effect of hydrostatic pressure of up to 9 kbar on the Curie point of nickel fluosilicate was investigated. The derivative dTc/dP in this pressure region changes sign twice—at the triple point (Pc =1.3 kbar, Tc = 0.12 °K and at a pressure of P = 5.8 kbar. The complex nature of the dependence of Tc on P is due to the competition between the exchange interaction and single-ion anisotropy.
Fermi-liquid cyclotron-doppleron waves in metals
Authors: Zimbovskaya N. A. , Okulov V. I. , Romanov A. Yu. , Silin V. P.
Published: December 2024

The frequency dispersion of Fermi-liquid cyclotron waves propagating along the direction of a magnetic field is investigated in metals whose Fermi surface has sections that are nearly paraboloids of revolution with maximum electron velocity on them. It is shown that in such metals with a negative interaction constant, the frequency of Fermi-liquid waves can be much lower than that of cyclotron waves, while the overall form of the dispersion curve is similar to the form that is characteristic for dopplerons. For a positive Fermi-liquid interaction constant the fequency of the waves can greatly exceed the cyclotron frequency. These characteristics greatly expand the region of existence of the Fermi-liquid waves and possibilities for observing them compared to the case of a spherical Fermi surface. A dispersion equation is obtained using a proposed approximation for the Fermi-liquid interaction function with axial symmetry and is analyzed in detail for the well-known model of a Fermi surface in the form of two paraboloidal cups. In this model the frequency of cyclotron-doppleron waves decreases with increasing wave vector or increases (depending on the sign of the interaction constant) linearly. The general conditions necessary for the appearance of the doppleron continuation of the dispersion curve of the cyclotron wave (Fermi-liquid doppleron) are found for an axially symmetrical Fermi surface and constant cyclotron frequency.
Mutual conversion of electromagnetic and acoustic modes under the conditions of doppleron–phonon resonance in tungsten
Authors: Golik A. V. , Korolyuk A. P. , Khizhnyi V. I.
Published: December 2024

The mutual conversion of electromagnetic and acoustic modes in tungsten in a constant magnetic field is achieved. It is shown that the observed features of the mode-conversion efficiency are attributable to the interaction of acoustic and Doppler-shifted cyclotron modes.
Fluctuation conductivity of thin superconductive vanadium films
Authors: Dmitrenko I. M. , Sidorenko A. S. , Fogel’ N. Ya.
Published: December 2024

Resistive transitions into the superconductive state are studied in thin [d <ξ(t)] vanadium films. For temperatures T≫Tc the experimental data on the excess conductivity of the films agree qualitatively and quantitively with Aslamazov–Larkin theory. There is no Maki–Thompson contribution to fluctuation conductivity. Near Tc the excess conductivity σ′ changes exponentially with temperature in accordance with the predictions of the theory of the critical fluctuations of the order parameter. The values of the effective charge carrier mass defined from data on σ′ for the low fluctuation and critical fluctuation regions differ markedly. This difference is within the spread of effective masses for various charge carrier groups already known for vanadium. Causes of the difference in resistive behavior for the regions T≲Tc and T≫Tc are considered.
Two-phonon electron scattering processes in metal point contacts
Authors: Yanson I. K. , Naidyuk Yu. G. , Shkyarevskii O. I.
Published: December 2024

Features observed at double phonon energies are investigated in detail in the point contact spectra of a number of metals. It is shown that they are related to sequential electron scattering by two phonons in the contact domain. A comparison of the experimental data with results of a theoretical model proposed earlier showed good qualitative and satisfactory quantitative agreement for metals possessing a simple phonon spectrum. With respect to the intensities of one and two-phonon processes, this permits determination of the presence and degree of homogeneity of an impurity distribution in the point contact domain.
Drag on magnetic solitons representing antiferromagnetic domain walls
Authors: Zuev A. V. , Ivanov B. A. , Sukstanskii A. L.
Published: December 2024

For the case of magnetic solitons corresponding to domain boundaries in antiferromagnets we consider the dynamic drag caused by processes involving thermal phonons. It is shown that the phonon drag is due to the scattering of phonons from moving domain walls and by processes in which a phonon is transformed into a magnon at a domain wall. We calculate the dependence of the domain wall drag force as a function of temperature and of the parameters of the antiferromagnet, and we present a comparison of the contributions to the domain wall drag due to the phonon and phonon-magnon processes.
Gas-modulated optoelectronic properties of monolayer MoS2 for photodetection applications
Authors: Prajapat Pukhraj , Vashishtha Pargam , Gupta Govind
Published: December 2024

Defects in monolayer MoS2 (M-MoS2) can cause complex electronic states that significantly affect its optical and electrical properties. Understanding and describing the impact of these defects, especially the role of sulfur vacancy (Vs) in M-MoS2 when integrating them into practical technologies, is crucial. However, a significant challenge exists in precisely controlling Vs generation in M-MoS2. This article presents an in situ defect engineering procedure for M-MoS2, considering the influence of external stimuli. We investigated how Vs changes and its impact on the optoelectronic characteristics of M-MoS2 after it is directly exposed to various gas environments. A photodetector device was fabricated, which exhibited an outstanding responsivity of 1.02 × 104 A/W, a detectivity of 1.2 × 1012 Jones, and an ultralow noise equivalent power of 1.56 × 10−18 W Hz−1/2. When the device is exposed to a reducing gas (H2S) environment, the performance increases by 136%, and in an oxidizing gas environment (NO2), it decreases by 68% in terms of responsivity due to a change in the concentration of Vs. We studied the photoresponse characteristics of the device by using Vs as the key parameter. This research contributes to the field of defect engineering in M-MoS2, expanding our knowledge of gas–surface interactions and assisting in producing highly sensitive optoelectronic devices.
Sexual satisfaction among people living with HIV in the era of biomedical prevention: enduring impacts of HIV-related stigma?
Authors: Norman Thomas , Bourne Adam , Thepsourinthone Jack , Murphy Dean , Rule John , Melendez-Torres G. J. , Power Jennifer
Published: December 2024

Background People living with HIV (PLHIV) have historically faced a range of challenges negotiating satisfying sex lives in the context of virus transmission risks and HIV-related stigma. We examine the experience of sexual satisfaction among PLHIV in an era of pre-exposure prophylaxis (PrEP) and undetectable=untransmissible (U=U)/treatment as prevention. Methods Data are derived from HIV Futures 9, a cross-sectional survey of PLHIV in Australia conducted between December 2018 and May 2019. Logistic regression was used to identify factors associated with sexual satisfaction, including awareness of/engagement with U=U and PrEP as well as experiences that denote HIV-related stigma. Results Over half (56.5%) of the total sample (n = 715) reported they were not satisfied with their sex lives. Those who avoided sex because of their HIV status (44.4%) were more likely to report sexual dissatisfaction, as were those who were aged 50 years or over and those with worse self-reported health. Participants who expressed a concern about their drug use were more likely to report sexual dissatisfaction when compared with those who expressed no such concern. Conclusions Concerns about HIV continue to be present in the lives of PLHIV and can interrupt or undermine intimate and sexual relationships. Although biomedical prevention technologies such as PrEP and antiretroviral therapy may alleviate anxiety relating to onward transmission of HIV, these findings indicate that concerns about HIV status, which may be related to experiences of stigma, are still adversely associated with enjoyment of sex for those living with HIV.
Higher identity resilience – self-efficacy is associated with sexual risk behaviours in gay men
Authors: Jaspal Rusi , Yenihayat Asrin
Published: December 2024

Cross-sectional survey data from 226 heterosexual and 201 gay men in the UK and Germany, analysed using moderation analyses, showed a positive relationship between identity resilience – self-efficacy and engaging in condomless sex and drug use in sexualised settings in gay men only. It is proposed that higher self-efficacy may lead to increased feelings of invincibility in gay men, which in turn is associated with sexual risk-taking.
Inferring phase transitions and critical exponents from limited observations with thermodynamic maps
Authors: Herron Lukas , Mondal Kinjal , Schneekloth John S. , Tiwary Pratyush
Published: December 2024

Phase transitions are ubiquitous across life, yet hard to quantify and describe accurately. In this work, we develop an approach for characterizing generic attributes of phase transitions from very limited observations made deep within different phases’ domains of stability. Our approach is called thermodynamic maps (TM), which combines statistical mechanics and molecular simulations with score-based generative models. TM enable learning the temperature dependence of arbitrary thermodynamic observables across a wide range of temperatures. We show its usefulness by calculating phase transition attributes such as melting temperature, temperature-dependent heat capacities, and critical exponents. For instance, we demonstrate the ability of TM to infer the ferromagnetic phase transition of the Ising model, including temperature-dependent heat capacity and critical exponents, despite never having seen samples from the transition region. In addition, we efficiently characterize the temperature-dependent conformational ensemble and compute melting curves of the two RNA systems: a GCAA tetraloop and the HIV-TAR RNA, which are notoriously hard to sample due to glassy-like energy landscapes.
Toward systems agroecology: Design and control of intercropping
Authors: Fedeli Sirio Belga , Leibler Stanislas
Published: December 2024

In view of changing climatic conditions and disappearing natural resources such as fertile soil and water, exploring alternatives to today’s industrial monocrop farming becomes essential. One promising farming practice is intercropping (IC), in which two or more crop species are grown together. Many experiments have shown that, under certain circumstances, IC can decrease soil erosion and fertilizer use, improve soil health and land management, while preserving crop production levels. However, there have been no quantitative approaches to predict, design, and control appropriate IC implementation for given particular environmental and farming conditions, and to assess its robustness. Here, we develop such an approach, based on methods and concepts developed in data science and systems biology. Our dataset groups the results of 2258 IC experiments, involving 274 pairs of 69 different plants. The data include 4 soil characteristics and 5 environmental and farming conditions, together with 8 traits for each of the two intercropped plants. We performed a dimensional reduction of the resulting 25-dimensional variable space and showed that, from a few quantities, one can predict IC yield relative to sole cultivation with good accuracy. For given environmental conditions, our computational approach can help to choose a companion plant and appropriate farming practices. It also indicates how to estimate the robustness of IC to external perturbations. This approach, together with its results, can be viewed as an initial step toward “systems agriculture,” which would ultimately develop systems of multiple plant grown together in appropriately designed and controlled settings.
Scalar diversity in L2 French speakers
Authors: Destruel Emilie , Starr Glenn
Published: December 2024

While scalar inferences associated with some have featured in most of the past investigations
into L2 implicature derivation, this study examines acquisition of pragmatic inferences licensed by adjective pairs (e.g.,
, ). Previous work has focused mainly on
direct scalar implicatures where an utterance containing a weak scalar term implicates the negation of the stronger. This work
extends the investigation to include focus on two additional inference types: indirect scalar implicatures, where not
brilliant conveys intelligent, and negative strengthening, a type of manner implicature where
not brilliant results in a rather dumb interpretation. Using an inference-judgment paradigm,
we test the interplay of these three inference types in adjectival scales for French speakers and L2 French learners and find that
response behavior is modulated by the availability of alternative meanings for each participant group. L2 learners demonstrated
familiarity with direct and indirect scalar implicature but lack awareness of negative strengthening. We interpret these results
by highlighting the role of processing complexity as well as pragmatic competence and proficiency. Overall, this study makes an
empirical contribution to the field of L2 acquisition and adds to building a more encompassing understanding of mechanisms that
are often assumed to be universal in language acquisition.
A task-based needs analysis of primary school-aged children with
migrant or refugee backgrounds in Austria
Authors: Trager Vera , Gilabert Roger
Published: December 2024

In this study, we report on a task-based needs analysis (TBNA)
for primary school-aged newcomers to Austria. 31% of Austria’s primary school
students learn German as L2 and thus a systematic analysis of their language
learning needs is crucial. Semi-structured interviews were conducted and a
survey was distributed. Results show 38 crucial target tasks for social and
academic integration and their respective rankings regarding perceived frequency
and the need for training. Triangulation of multiple sources and methods
facilitated the identification of target tasks in various life domains and the
development of detailed task descriptions along multiple task dimensions.
Collectively, the results provide a basis for task selection, task sequencing,
and the development of a meaningful syllabus for refugee/migrant populations at
the primary school level in Austria.
Stability of Kadomtsev–Petviashvili multi-line solitons
Authors: Wu Derchyi
Published: December 2024

We prove the long-standing inverse scattering theory (IST) of perturbed Kadomtsev Petviashvili multi-line solitons. Our work is the first rigorous IST of a multi-dimensional integrable system that addresses both continuous and discrete scattering data, ensuring that the support of the continuous scattering data does not degenerate into contours in the complex plane. As an application, we justify an

L
∞

-stability theorem for the Kadomtsev–Petviashvili multi-line solitons.
A comprehensive DFT study of the effect of the pressure on the structural, stability, electronic, optical, and mechanical properties of cubic RbSrI3
Authors: Abdulkareem Nawzad A
Published: December 2024

This study examines the structural, electrical, optical, and mechanical effects of hydrostatic pressure on cubic I-II-halide perovskite RbSrI3. The exchange–correlation term of the Khon-Sham equation is expressed using PBE-GGA. For all calculations, QuantumESPRESSO is used. PBE-GGA and pseudopotentials have been employed for ion-valence interaction. Under hydrostatic pressure, the lattice parameter

a

dropped from 6.34 Å. The structure is thermodynamically stable since the formation energy

E

f

is negative and lowers as the negativity falls until pressure 31 GPa, when it becomes positive. This material depicts the transition from an indirect band gap at ambient pressure to a direct band gap that accelerates electron valence-to-conduction band transition. The band gap rises to 7 GPa, then falls to 1.49 eV at 50 GPa. The PDOS explains that the states that contribute to creating VBM and CBM changes in overlapping status and value which leads to such behavior of electronic nature. Optical properties show a stronger response at 50 GPa pressure, with

ε

1

(
ω
)

and

ε

2

(
ω
)

exhibiting similar behavior and a maximum value of nearly 10. However,

ε

1

(
ω
)

peaks in the visible light zone, while

ε

2

(
ω
)

peaks in the ultraviolet zone. This means the material absorbs and retains visible and ultraviolet radiation at its optimal level. Mechanical and elastic parameters were determined using finite strain theory. Born stability confirms mechanical stability since

C

11

,

C

44

,

C

11

−

C

12

, and

C

11

+
2

C

12

have positive values and remain positive as pressure increases. Elastic moduli such bulk modulus (

B

), shear modulus (

G

), and Young’s modulus (

E

) indicate moderate hardness and resistance to pressure. Additionally, Poisson’s ratio (

υ

), Pugh’s ratio, and Cauchy pressure (

σ

) indicate ductility at ambient pressure, since they align with boundary values of υ (0.2959 > 0.26),

σ

(0.92) (positive), and

B
/
G

(2.23 > 1.75) (at ambient pressure). Increased pressure enhances ductility.
Real-time surface defect detection algorithm on aluminum ingot alloy casting lines
Authors: Chen Hong , Yan Feiya , Yang Jing , Yan Jianguo , Qin Tao , Zhang Jing
Published: December 2024

Aluminum alloy ingot surface defect detection technology is crucial to ensure that product quality meets standards. Existing inspection model inspection precision and speed are difficult to meet requirements of fast and accurate detection on production lines, to address this problem, a new real-time surface defect detection algorithm Al-YOLO on aluminum alloy ingot casting line was proposed. Firstly, K-Means++ was embedded into YOLOv5 to optimize the detection anchor frame for the aluminum alloy ingot scenario. Secondly, the structural reparameterization technique was used to design the main trunk to speed up the model inference speed. Then combined with the dynamic head framework known as DyHead, the attention mechanism was unified with the detector’s head, thereby enhancing the precision of small defect identification. Finally, the Focal function was introduced, and combined with EIoU to get the Focal-EIoU border regression loss function to address the uneven sample distribution. On the aluminum alloy ingot surface defects dataset, the mAP of Al-YOLO reaches 72.5%, and the FPS also reaches 57.1, which improves the mAP and FPS by 4.0% and 11.2, respectively, compared to the original model, and outperforms the current mainstream detection methods on the NEU-DET dataset. Experimental evidence Al-YOLO has better inspection precision and speed, which can better adapted to the requirements of fast and accurate detection in production lines.
A selective chaos-driven encryption technique for protecting medical images
Authors: Chen Yucheng , Huang Huiqing , Huang Kekun , Roohi Majid , Tang Chunming
Published: December 2024

Smart devices, embedded in daily life, have limited memory, power, and processing capabilities, making traditional cryptography impractical and driving the development of lightweight cryptography. Selective encryption of medical images has gained significant attention for its lightweight performance. Nevertheless, existing methods face security challenges, such cannot resist chosen-plaintext attacks, that limit their practical use. To overcome these challenges, this paper introduces a novel selective encryption scheme based on chaos theory. The approach identifies regions of interest in medical images using an adaptive statistical threshold based on pixel intensity values, forming a sub-image block for encryption. The scheme employs a permutation-diffusion structure, utilizing bit-level circular shifts and pixel shuffling to modify both pixel positions and values. A randomized encryption operation in the diffusion phase ensures security against chosen-plaintext attacks. The final encrypted image integrates the encrypted sub-blocks with unencrypted regions, achieving a balance between efficiency and security. The comprehensive evaluation corroborates that our solutions outperform the existing state-of-the-art schemes regarding security and performance. Therefore, our proposed scheme is a practical solution for lightweight medical image protection in resource-constrained applications.
Prediction of human disease complication incorporating machine learning and local network structures
Authors: Xiong Long , Jiang Xiong-Fei , Liu Ri , Zhang Jiu , Zhang Jing-Feng , Zheng Jian-Jun , Zheng Bo
Published: December 2024

Complications have long haunted physicians and patients in clinical medicine. However, the evaluation of complications caused by specific diseases is typically relied on the experience of clinicians or clinical cases. Especially, vast complication diseases involve multiple human body systems, increasing the difficulty of the clinical confirmation. Based on a large scale human disease complication network extracted from the clinical medicine knowledge database, we propose a nonlinear model combined local topological structures and machine learning to explore latent disease-complication relations. As an example, we apply the model to predict unidentified complications of COVID-19 and to detect potential extrapulmonary complications which are significant in the post-pandemic period. Our approach provides an efficient method to identify the candidate complications from the structure of complex network.
Numerical investigation on the flow and heat transfer performances of a novel microchannel heat sink arranged with inclined pin fins
Authors: Yuan Jin , Deng Ningkang , Qu Yongfeng , Du Liang , Hu Wenbo , Zhang Zhaoyang , Wang Hongxing
Published: December 2024

The advancement of microelectronics technology has led to an increased demand for heat dissipation in devices. In response to this challenge, microchannel heat sinks (MCHS) have been introduced as a viable solution. The heat dissipation capabilities of MCHS can be enhanced by adopting pin fins, which serve to augment the solid–liquid contact area and disrupt the fluid boundary layer. Most research on MCHSs with pin fins has concentrated on vertical pin fin configurations, with a comparatively limited investigation into inclined pin fins. To further enhance the thermal performance of MCHS with pin fins, this study presents a novel MCHS with inclined pin fins (MCHS-IPF). The flow and heat transfer characteristics under steady-state conditions were analyzed using three-dimensional numerical simulations. Additionally, geometric optimization was conducted on the tilt angle (θ: −30° to 30°, excluding 0°) and the secondary flow channel width ratio (β) to achieve improved overall performance. The results show that the MCHS-IPF significantly enhances thermal dissipation capability compared to a conventional MCHS with vertical pin fins (MCHS-VPF). As the tilt angle remains constant, the heat dissipation capacity of MCHS-IPF improves with an increase in β. The MCHS-IPF with β = 0.6 and θ = −30° at Re = 600 shows a notable enhancement of 57.7% in the Nusselt number compared to the MCHS-VPF. This MCHS-IPF also demonstrates superior overall performance in this study, achieving a maximum Performance Evaluation Criteria of 1.53, thereby establishing itself as the optimal structure.
Enhanced supercapacitor performance and hydrogen evolution reaction using Nb2CTx MXene-integrated HKUST-1 MOF
Authors: Anwar Rimsha , Umar Ehtisham , Iqbal Muhammad Waqas , Sunny Muhammad Arslan , Ul hassan Haseeb , Asiri Yazeed , Amin Mohammed , Ismayilova Narmin Arif , Alrobei Hussein , Mohammad Akbar , Alawaideh Yazen
Published: December 2024

This work aims to investigate how HKUST-1 metal-organic framework (MOF) and Nb2CTx MXene operate in concert to improve the catalytic activity in the hydrogen evolution reaction (HER) and the effectiveness of supercapacitors. While HKUST-1 offers a very porous structure that is favorable for charge storage, Nb2CTx serves as both a conductive substrate and a catalytic site for HER. This combination leads to better charge transfer channels and increased electroactive sites, which ultimately results in higher HER efficiency (shown by a notably lower Tafel slope of 52.42 mV/dec). In configurations of two and three electrodes, a specific capacity of 2168 C/g at a current density of 1.0 A/g is demonstrated by HKUST-1/Nb2CTx Moreover, the theHKUST-1/Nb2CTx combination, in particular the HKUST-1/Nb2CTx//AC composite, shows remarkable stability; after 1000 cycles, they still retain 95 % of their capacity and achieve 97% coulombic efficiency. The HKUST-1/Nb2CTx decorated electrode exhibited energy and power density, reaching approximately 89 Wh/kg and 938 W/kg in two-electrode (real device) configurations. These results highlight the HKUST-1/Nb2CTx composite excellent potential in energy conversion and storage applications.
Deterministic interconversion of the Greenberger–Horne–Zeilinger state and Knill–Laflamme–Milburn state via Lie-transform-based pulse design in Rydberg atoms
Authors: Wang J P , Ji Y Q , Yang L P , Wang C Q , Dong L , Xiu X M
Published: December 2024

Conversion between different types of entangled states is an interesting problem in quantum mechanics. But research on the conversion between the Greenberger–Horne–Zeilinger (GHZ) state and Knill–Laflamme–Milburn (KLM) state in an atomic system has not been reported. In this paper, we propose a scheme to realize the interconversion (one-step) between the GHZ state and KLM state with Rydberg atoms. By utilizing Rydberg-mediated interactions, we simplify the system. By combining a Lie-transform-based pulse design, the evolution path is built up to realize interconversion of the GHZ state and KLM state. The numerical simulation result shows that the present scheme is robust against decoherence and operational imperfection.
Ion-acoustic shock and solitary waves in magnetized plasma with Cairns–Gurevich distribution electrons
Authors: Huo Rui , Du Jiulin
Published: December 2024

The propagation properties of ion-acoustic solitary and shock waves in the magnetized viscous plasma with nonthermal trapped electrons are investigated. The Cairns–Gurevich distribution as the electron distribution is considered to describe the plasma nonthermality and particle trapping. By adopting the reductive perturbation technique, we derived the nonlinear Schamel–Korteweg–de Vries–Burgers (SKdVB) equation, and then obtained the ion-acoustic shock and solitary wave solutions of the SKdVB equation for different limiting cases. It is found that the impact of nonthermal parameter α, external magnetic field Ω, obliqueness l

z
, wave speed U
0, and the ion kinematic viscosity η
0 can significantly change the characteristics of the shock and solitary waves. These results may be useful for better understanding the propagation of nonlinear structures in space (i.e. Earth’s magnetosphere and ionosphere, auroral regions) and laboratory plasma with nonthermal trapped electrons.
Tracking healing effect of human Wharton’s jelly stem cells labeled with superparamagnetic iron oxide nanoparticles seeded onto poly vinyl alcohol/chitosan/carbon nanotubes in burn wounds by MRI, and Prussian Blue staining
Authors: Hashemi Seyedeh-Sara , Niknam Zeinab , Mojtaba Zebarjad Seyed , Mehrabani Davood , Jalli Reza , Saeedi-Moghadam Mahdi , Behroozi Rezvan , Zare Shahrokh , Jamhiri Iman , Derakhshanfar Amin , Moayedi Javad , Nazempour Mehra , Rasouli-Nia Aghdass , Karimi-Busheri Feridoun , Khonakdar Hossein Ali
Published: December 2024

Regenerative medicine by applying tissue engineering and cell transplantation has provided a new door in wound healing. This study tracked healing effect of human Wharton’s jelly stem cells (WJSCs) labeled with superparamagnetic iron oxide nanoparticles (SPIONs) seeded onto poly vinyl alcohol/chitosan/carbon nanotubes (PVA/CS/CNT) in burn wounds by magnetic resonance imaging (MRI) and Prussian Blue staining.
Study on optimization design of pump turbine with high head based on CFD technique
Authors: Liao Xiangbo , Zheng Yang , Zhang Chiye , Zhao Wengui , Ma Zhe , Luo Qianlin , Meng Long
Published: December 2024

Based on the characteristics of large capacity of high head pumped storage power station in China, by taking CFD technology to carry out optimization design of pump turbine. The hydraulic design and flow characteristic of pump turbine are emphatically studied. In this paper, the hydraulic performance of pump turbine is estimated by numerical simulation method. Based on the runner scheme with the relative guide vane height of b0/D1=0.10, the hydraulic design is carried out to realize the safe and stable operation of the unit within the operating range. Based on the numerical simulation optimization design method, the runner shape, the wrap angle and the setting edge of blade were optimized to improve the hydraulic performance. The final JFP09 pump turbine meets the performance requirements within operating range. The optimized pump turbine can not only meet the performance level of pump flow, hump safety margin and hydraulic efficiency in small flow area, but also satisfy the cavitation performance in large flow area. Meanwhile, the energy matching relation of pump turbine under two-way operation condition can be considered as well. The study result shows that the optimization design based on CFD technique is a reasonable and effective method. The research method will provide guidance for the optimization design of pump turbine.
Multi-scale oscillation of pumped storage - wind power coupling system with surge tanks
Authors: Li Jiening , Guo Wencheng , Song Fanchao , Shu Kedong , Huang Min
Published: December 2024

Under grid-connected operation, pumped storage - wind power coupling system (PSWPCS) with surge tanks generates the problem of multi-scale oscillation, which leads to the complexity of dynamic response and difficulty of regulation control. Thus, this paper researches the multi-scale oscillation of PSWPCS with surge tanks. Firstly, the mathematical equations of PSWPCS with surge tanks are established. Then, the multi-scale oscillation and effect rules of surge tank area are investigated. Finally, the influence mechanism of multi-scale oscillation is studied. The results indicate that PSWPCS with surge tanks has multi-scale oscillation. The ultra-low frequency damping performance of upstream and downstream surge tanks is stronger than that of single surge tank, and the negative damping characteristics of which changes significantly with the 50% increase of upstream surge tank area. A larger water head of power station and smaller head loss of headrace tunnel are easier to induce the ultra-low frequency oscillation. The pitch angle controller of wind turbine can significantly suppress the low frequency oscillation under larger proportional and smaller integral gain. When proportional and integral gain of phase-locked loop controller are small, the sub-synchronous oscillation will be excited. Smaller stator self-inductance and rotor resistance can improve the system regulation performance.
Transfer and measurement of power plant transients on a high-performance closed-loop test rig
Authors: Geiger C , Kirschner O , Riedelbauch S
Published: December 2024

As hydro power plants become more and more flexible in their operation, the associated transient processes and the resulting loads on the hydraulic machinery are becoming increasingly important. In addition to numerical analysis, measuring of the transient processes using model test rigs plays an important role. The aim is to determine the effects of the transient operating modes in model tests and to transfer the knowledge gained to the prototype. Therefore, the real transient processes of a hydro power plant and the load on the hydraulic machine must first be reproduced on the test rig. The transient turbine start-up of a hydro power plant is analysed in more detail. The first step is to model the entire hydro power plant and calculate the corresponding start-up process. The boundary conditions applied to the hydraulic machine are transferred to the model machine on the test rig using similarity laws; a time scale adjustment is made using the Strouhal number. The time dependent boundary conditions at the model machine are set by varying the rotational speed of a service pump arranged in the test rig and the transient start-up process is measured.
Pelton turbine needle eccentricity leading to asymmetric hydro-abrasive erosion
Authors: Shrivastava Navam , Kumar Rai Anant
Published: December 2024

Hydropower generation of turbines located near geologically young mountain ranges like the Himalayas is challenged by incoming sediment particles. Pelton turbines installed at high heads are significantly affected by hydro-abrasive erosion due to high flow and erosion velocities. The injector of the Pelton turbine is one of the major components of the Pelton turbine affected by hydro-abrasive erosion. Improper installation or manufacturing defect leads to needle eccentricity causing an asymmetric erosion pattern of the injector, thereby reducing jet quality. Here, the effect of needle eccentricity on hydro-abrasive erosion of the injector is numerically investigated by tracking the sediment particles using the Discrete Phase Model (DPM). The intensity and asymmetricity in the erosion of the needle increases with an increase in needle eccentricity. Similar behaviour in the erosion of the needle is observed in reducing the nozzle opening of the eccentrically displaced needle. For a perfectly aligned needle, the average erosion rate in both the upper and lower half region of the needle was identical. However, with 8% of needle eccentricity, the average erosion rate in the upper half region of the needle i.e., towards the displaced side was 89% more compared with the lower half region of the needle. The study emphasises the necessity of inspecting the needle alignment, particularly post-maintenance to mitigate the detrimental effects of hydro-abrasive erosion on Pelton turbine performance.
Onsite performance testing of Archimedes hydropower screw for low head and ultra-low head hydro power project– A case study
Authors: Pillai Deepak S , Stephen Christopher , Tiwari Durgesh K , Singh Manish
Published: December 2024

A low head hydro project refers to hydropower sites operating at head less than 40 m and an ultra-low head refers hydropower sites operating at head less than 3 m or water flow greater than 0.5 m/s with a zero head. These hydro sites though ubiquitous, were not developed at the same pace as medium and high head sites. These sites can play a crucial role in the capacity addition of 45 GW per year for net zero by 2050 according to the International Hydropower Association report. With the introduction of Archimedes screw technology, these sites can be developed both technologically and economically. This paper presents a case study on first of its kind performance testing of electro-mechanical equipment at Archimedes screw projects located in the Vadodara Branch Canal of Sardar Sarovar Narmada Nigam Limited Gujarat. The performance testing was conducted on 4.3 m diameter Archimedes screw designed for a rated head of 6.5 m, and a rated discharge of 7.45 m3/s. The project is designed to deliver 410 kW turbine output, with an inclination angle of 26 degrees from horizontal. The onsite performance study carried out indicates that the achieved Archimedes screw efficiency is 86.6 %.
Assessment of Organic Pollutant Index and Biodegradability Index in Determining River Pollution Load
Authors: Setyawan A , Muhammad F , Hermawan F
Published: December 2024

The Kupang River, a major watershed in Batang and Pekalongan, spans 53 kilometres and has been experiencing significant water quality degradation. Notably, the river’s colour changes to black and emits foul odours, especially during the dry season. This deterioration is attributed to extensive batik industries and residential areas along its banks, leading to severe pollution. This study aims to identify the primary factors contributing to the pollution of the Kupang River from 2021 to 2024 using organic pollutant and biodegradability index. Pollution loads were calculated across five monitoring segments to determine the river’s waste disposal capacity. The findings reveal potential agricultural pollution in the upstream segment, indicated by slow-biodegradable and non-biodegradable degradation. Thus, the downstream segment shows high levels of organic pollution, with degradation ranging from moderate to very strong polluted levels. Pollution load calculations indicate that Kupang River can accommodate pollution loads for TSS up to 30294,49 kg/day, BOD up to 763,03 kg/day, and COD up to 5935,96 kg/day. However, BOD’s low pollution load capacity should be a serious concern, highlighting severe contamination issues that necessitate immediate attention and remediation.
Analysis of cadmium (Cd) and iron (Fe) heavy metal content in the river around Putri Cempo landfill, Surakarta
Authors: Setyono P. , Sunarhadi R. M. A. , Putri D. S. , Fauziah I. , Andrianto R. , Sari Y. D. , Firdausi E.
Published: December 2024

Data from the Ministry of Environment and Forestry’s National Waste Management Information System (SIPSN) shows that by 2023, 33.18% or equivalent to 6.5 million tonnes of waste in Indonesia will still accumulate without adequate handling. The continuous accumulation of waste in landfills will produce pollutants in the form of leachate that can pollute groundwater and rivers. Leachate can result in the presence of heavy metals in water, including heavy metals cadmium (Cd) and iron (Fe). This condition is a threat to the ecosystem in river waters and can indirectly have an impact on human health. This study aims to determine the content of heavy metals cadmium (Cd) and iron (Fe) in the river around the Putri Cempo landfill in Surakarta City, Central Java. The sampling point is at coordinates 7°32′14.4 ‘S 110°51′30.0 ’E, then testing for heavy metal content using the Atomic Absorption Spectrometry (AAS) method. The results showed that the cadmium (Cd) content in the river water was relatively low at -0.0274876 mg/L. This is caused by several factors, namely the nature of Cd which is not easily soluble in water so that it easily settles into sediment, the dilution of river water by rain, and the river is far from the industrial area. In contrast to Cd, iron (Fe) levels in river water far exceed the safe limit of 7.98940397 mg/L. This indicates that the river water in the area has been heavily polluted by heavy metal iron (Fe). The high levels of iron (Fe) are caused by the disposal of iron-containing domestic waste, the presence of iron water reservoirs in the Putri Cempo landfill, and corrosion of water pipes that contain iron (Fe).
Utilization of fly ash composite from municipal solid waste incineration (MSWI) as an adsorbent to remove methylene blue from wastewater
Authors: Nurianto T M , Laksono S , Kusrestuwardhani  , Adityosulindro S
Published: December 2024

Utilization of MSWI fly ash and corncob by combining fly ash and corncobs with a 1:10 ratio, activated with 75% KOH as an adsorbent to reduce methylene blue dye in textile wastewater. For the characterization testing of FACC, SEM-EDS, and pHpzc were used to determine the morphological conditions and pH value when FACC is in zero charged condition. Characterization results show that FACC has a rough surface and many pores with O, C, and K as dominant elements. pHpzc test shows that FACC will have a zero charge at pH 13.18. Experiments were conducted with batch method on the effect of adsorption operational parameters at contact time (0-120 min), FACC dosage (0.05-0.5 g/L), pollutant concentration (50-250 mg/L), and initial pH (2-10). Maximum removal efficiency was obtained at a contact time of 60 minutes, with a dosage of 0.5 g/L, pollutant concentration of 50 mg/L, and initial pH of 4 with a removal % of 98.37%. The Langmuir isotherm model described the adsorption mechanism with the maximum adsorption capacity reaching 344.828 mg/g. The adsorption rate used a pseudo-second-order kinetics model with a K2 value of 13.9 × 10−3 g/mg.min. FACC are good adsorbent alternatives for removing dyes in industrial wastewater.
The effect of multi-rods helical system configuration on the reduction of chemical oxygen demand in textile wastewater in tubular electrocoagulation reactor
Authors: Maharani Valencia Safir , Ardhianto Rachmad , Sudarno
Published: December 2024

The electrocoagulation process is designed with a multi-rod helical system (MRHS) configuration in the cathode area. The objective of this research is to present a comprehensive overview of electrocoagulation techniques and applications employing a multi-rod helical system. The objective of this configuration is to provide a reference point for the industry about the efficiency and effectiveness of the electrocoagulation process. The study was conducted on a pilot scale in an on-site textile industry setting, allowing for a more practical and realistic assessment of the process. The efficacy of the treatment was evaluated in terms of its removal performance. the multi-rod helix system process demonstrated high efficiency in current utilization for the removal of chemical oxygen demand (COD) from textile wastewater through electrocoagulation. the findings suggest that the system unit is capable of enhancing pollutant removal and effectively reducing the chemical oxygen demand (COD) of textile wastewater. the pilot-scale configuration yielded the most optimal results in COD removal, with efficiencies ranging from 35 to 91% at pH 6-7, energy consumption between 0.25 and 1.69 kWh/m3, and current density between 465.28 and 823.19 A/m2.
Comparison of microplastic abundance and characteristics in rural rivers : Hamada River, Japan and Mlese River, Indonesia
Authors: Wardhani W K , Andarani P , Yokota K , Ngoc N M , Sudarno S , Syafrudin S , Inoue T
Published: December 2024

Microplastics have negative chemical and ecological effects on aquatic biota and humans. However, few studies have explored the abundance of microplastic in rural river. This study aims to compare of the abundance of microplastic, size distribution, color, and polymer types in rural river of Japan and Indonesia. Data were collected at one of river point in the in the Hamada River, Japan during dry season and Mlese River, Indonesia during rainy season. The sampling and analysis methods were in accordance with the Japanese Riverine Microplastic Survey Guidelines, the microplastics in the range of 500-5,000 μm were determined by optical microscopy and FTIR spectroscopy. Film shaped, size 1,000-3,000 μm, and polymer type polyethylene and polypropylene were the majority of the identified microplastics both in Hamada River and Mlese River. Meanwhile, the dominated colors were gray for Hamada River and transparent for Mlese River. The abundance of microplastic were 5.5×10−2 particles/m3(discharge:0.032 m3/s) for Hamada River and 2.2×10−3 particles/m3 (discharge:8.12 m3/s) for Mlese River. A low abundance of microplastic in Mlese River is a result of the high flow velocity and discharge. Moreover, that shows Hamada River’s microplastic is 26 times greater, this indicates that Japan uses more plastic products to support crop production compared to Indonesia and influence the river water pollution by microplastics.