bluuebunny/crossref_metadata_2025 huggingface dataset:
Complex nonlinear dynamics of a multidirectional energy harvester with hybrid transduction
Authors: Costa Luã G , Savi Marcelo A
Published: September 2024

Mechanical energy harvesting has increasing scientific and technological interests due to novel energetic challenges. A critical issue in classical cantilever-based mechanical energy harvesting systems is the lack of multidirectional energy conversion capabilities and, due to that, deviations from the excitation source can drastically reduce their performance. This limitation has led to the development of energy harvesters with attached pendula, serving as a direction coupling mechanism. Nevertheless, the pendulum structure itself can act as an energy absorber, drastically reducing the harvester performance in certain scenarios. In order to overcome this issue, a hybrid multidirectional pendulum-based energy harvester has been introduced by the authors. The hybrid transduction integrates a piezoelectric element to capture energy from the principal direction and an electromagnetic transducer to harness rotational energy from the pendulum. This paper presents an in-depth analysis of the hybrid multidirectional pendulum-based energy harvester using a nonlinear dynamics perspective to evaluate the energy harvesting performance. A reduced-order model is proposed to represent the essential characteristics of such systems. A parametric analysis using a nonlinear dynamics perspective is carried out to map the system dynamics and performance. The emergence of complex and rich dynamics is observed, including chaos and hyperchaos. Results reveal the most and least effective combinations of structural parameters in terms of energy conversion. Additionally, the dynamical responses and patterns associated with high performance are identified. These responses are often characterized by a blend of irregular complex behaviors, coupled with a mix of oscillatory and rotational patterns of motion, resulting in wider bandwidth systems.
Modeling of dynamic characteristics and μ-synthesis control of piezoelectric positioning platform
Authors: Duan Shiyu , Liu Haotian , Zhang Guilin
Published: September 2024

The dynamic hysteresis nonlinearity and various uncertainties of the piezoelectric positioning platform are critical factors limiting its high-precision applications. To address this, the dynamic characteristics of the piezoelectric positioning platform under various loads are identified based on the linearization of the Prandtl–Ishlinskii inverse model. The inverse compensation error and load disturbances are attributed to model uncertainties, which are modeled in the frequency domain. A μ-synthesis controller is designed to improve the tracking accuracy of the piezoelectric positioning platform under uncertainty disturbances. The experimental results of sine wave tracking indicate that with the μ-synthesis controller, the piezoelectric positioning platform achieves a relative error (RE) of less than 2.71% when unloaded. The RE is less than 6.03% for load disturbances of 100 g, 200 g, and 300 g, respectively. These results demonstrate that the designed controller meets the high-precision positioning performance requirements under various load disturbance conditions.
Microwave loss and kinetic inductance of epitaxial TiN films
Authors: Wu Yu , Liu Yixin , Gao Wanpeng , Wang Xiaoni , He Xiaoliang , Jin Hua , Peng Wei , Mu Gang , Lin Zhirong , Wang Zhen
Published: September 2024

Low microwave loss and regulatable kinetic inductance are two key characteristics of superconducting films to manufacture high-performance quantum devices. Epitaxial titanium nitride (TiN) thin films have been found to exhibit significant advantages in these two aspects. In this paper, we investigated into the dielectric loss and kinetic inductance of epitaxial TiN films, which were prepared on both silicon and sapphire substrates with different temperatures. Crystal structure, surface morphology, and superconducting properties were characterized systematically. The radio-frequency response of microwave resonators made of TiN films was studied at low temperatures to extract the information of kinetic inductance and quality factor. We obtained the highest internal quality factor up to

1.6
×

10

6

at single photon regime and achieved a regulation of kinetic inductance exceeding 16 times by altering the substrate and the sputtering temperature of the TiN films. This work not only provides an essential foundation for the precise design and preparation of low-loss TiN resonators for superconducting quantum bits, but also demonstrates TiN film as an excellent material platform with both low microwave loss and high kinetic inductance that can be applied in other fields such as microwave kinetic inductance detectors.
Effective spin models and magnetic phases of an insulating bosonic ladder with unconventional synthetic flux
Authors: Pan Zong-Zhen , Yang Shi-Jie , Zheng Yi
Published: September 2024

We investigate the Mott insulating phases of a two-component bosonic lattice gas in the presence of gauge field. Such a system is described by a two-leg ladder model with an unconventional flux. The synthetic flux is generated by the spin-dependent tunneling and the site-dependent spin-flip. In the Mott regime, these two effects lead to Dzyaloshinskii-Moriya (DM) interaction and an external field that is rotating in the xy-plane. We obtain a very general XYZ model with the DM interaction, the spiral field, and the transverse field. Various interesting magnetic Hamiltonians can be covered by adjusting lattice parameters. The DM interaction or the spiral field can lead to spiral order when they appear alone. The interplay of DM coupling and spiral field leads to the emergence of a new multi-frequency spiral order between the paramagnetic phase and the spiral ferromagnetic phase. Ground state phases are investigated by focusing on order parameters, spin-spin correlation functions, and structure factors. Calculations are performed by using time evolution block decimation (TEBD) based on matrix product state (MPS).
Characterization of graphite and ZrO2 reinforced aluminium metal matrix composite for enhanced mechanical properties in electronics applications
Authors: I Duraimurugan , K Anandavelu , R Pandiyarajan
Published: September 2024

The objective of this work is to examine the wear properties of a hybrid Metal Matrix Composite (MMC) consisting of 92 weight percent (wt%) Aluminium Alloy 6061 (AA6061), 2 wt% Graphite (C), and 6 wt% Zirconium Dioxide (ZrO2). It was previously determined that this composition was ideal for improved metallurgical and mechanical properties. Nine specimens of the same composition were fabricated for this continuation work and put through wear tests with different applied load, sliding velocity, and sliding distance settings. To evaluate the performance of the composite, measurements were made of the wear rate and Coefficient of Friction (COF). According to the results, the wear rate typically increased as the applied load and sliding velocity increased. At the lowest load (10 N) and velocity (2 m s−1), the lowest wear rate (50.90 μg) and COF (0.197) were noted. Specimens with lower wear rates had smoother surfaces and less wear, as revealed by SEM analysis of the worn surfaces; specimens with higher wear rates showed more significant surface damage, such as deeper cuts and serrations. In specimens with less wear, XRD analysis verified the presence of crystalline aluminium, indicating a strong correlation between wear resistance and the crystalline structure of the composite. Linear regression equations were created to predict wear behavior under different conditions. According to the results, the composite’s wear characteristics are greatly influenced by the sliding velocity and applied load. ZrO2 and C together have lubricating and strengthening properties that, under certain circumstances, reduce wear. The composite exhibits potential for usage in electronics applications, especially in components where wear resistance and mechanical durability are critical due to its favorable wear characteristics and mechanical properties.
Construction of novel nanocomposite based on the reduced graphene oxide/metalation of porphyrin for photocatalytic process by real sample analysis and antimicrobial applications
Authors: Syed Asad
Published: September 2024

The main objective of this study is to prepare and combine reduced graphene oxide (rGO) with copper-5,15-bisdodecylporphyrin (Cu-Por) nanoparticles in order to produce a unique rGO-loaded Cu-Por nanocomposite. Characterization techniques such as scanning electron microscopy (SEM), Raman spectroscopy, x-ray diffraction (XRD), x-ray photoelectron absorption spectroscopy (XPS) and ultraviolet-visible (UV–vis) spectroscopy were utilized to analyze the structure of the synthesized rGO/Cu-Por. The effectiveness of the resulting rGO/Cu-Por nanocomposite as a catalyst was evaluated based on several parameters, such as pH, the initial concentration of the MR dye, and the amount of nanocomposite employed. Remarkably, a quantity of 20 mg of the rGO/Cu-Por nanocomposite demonstrated a significant removal efficiency of 99.7% for MR at a pH level of 3.5. The actual sample exhibited a degradation amount of 69.21%. In addition, the antimicrobial efficacy of the nanocomposite was assessed against the G-negative and the G-positive bacterium Staphylococcus aureus. The findings demonstrate that the rGO/Cu-Por nanocomposite displayed significant antimicrobial activity with great zone of inhibition values.
Improving phase sensitivity of a hybrid interferometer with the two-mode squeezed coherent state
Authors: Shao Tao , Ruan Pengxiang , Zhang Minyang , Wang Yuanxiang , Zhang Mingming , Jing Qingli , Liu Jun
Published: September 2024

We investigate the enhancement of phase sensitivity of a nonlinear-linear hybrid interferometer with the input of the two-mode squeezed coherent state (TMSCS). With the TMSCS produced by four-wave mixing, the quantum Cramér-Rao bounds (QCRB) can beat the Heisenberg limit (HL). Under the phase matched conditions, the optimal phase sensitivity with the balanced homodyne detection measurement can beat the HL and approach QCRB. The effects of internal and external losses on the measurement accuracy are also discussed. The results demonstrate that the scheme is robustness against to internal losses and this protocol can resist external detection loss which is up to 39%. Our results improve the performance of hybrid interferometers and this scheme can find important practical applications in quantum metrology.
Topological edge states of acoustic zigzag tubes with triangle scatterers
Authors: Liu Yan , Wang Lifeng
Published: September 2024

Tubular geometries in phononic crystals have the advantages of hosting topological edge states without breaking the underlying symmetry of the lattice. The topological relationships between the acoustic zigzag tubes and the dispersion relation of the planar phononic crystal with a zigzag edge boundary are theoretically revealed through 2D k space analysis, circumferential pressure analysis, and lattice symmetry analysis. New cutting lines of the tubes are obtained, which link the winding number of the tubes with the dispersion relation of topological edge states in the planar phononic crystal. The eigenstates analysis shows that the circumferential periodic number of a tubular edge state is regular and corresponds to a specific wavenumber in the circumferential direction. On the basis of the unveiled topological relationships, tubular edge states with tunable properties are obtained by controlling the characteristic length of the boundary scatterers. Moreover, the tubular edge states are confirmed to be highly confined and robust along the designed transmission channel. This study may present a new way to design acoustic tubes with tunability and have potential applications in robust wave propagation and miniaturized phononic devices.
Analysis of short-term self-healing performance of asphalt mixture under a three-point bending fatigue test
Authors: Wang Ya , Zhang Liwen , Wang Xianguang
Published: September 2024

To evaluate the self-healing performance of asphalt mixture under repeated loads, indoor three-point bending fatigue tests and self-healing tests were conducted on asphalt mixture AC-13. The stress control mode was selected to test the fatigue resistance of the mixture, and the dissipated energy recovery value and visco-elastic ratio were proposed to evaluate the self-healing performance of the mixture. The experimental results show that there is a good linear relationship between fatigue life and fatigue stress, and the damage degree to the mixture is exponentially related to the load times. The numerical dispersion of flexural tensile modulus is large, which is not suitable for evaluating the self-healing performance of the mixture. As the number of loading cycles increases, the hysteresis dissipated energy of the mixture gradually decreases and tends to stabilize. After the loading interval, due to the self-healing effect, the visco-elastic performance of the asphalt material is partially restored. The initial dissipated energy before and after interval can be used as an evaluation index for self-healing behavior, and there is a good linear relationship between the initial dissipated energy and the damage degree. Due to the deformation migration of the mixture during the initial loading stage before and after interval, the visco-elastic ratio has changed, and this change becomes more pronounced with the damage degree of the mixture, indicating that the self-healing ability of the mixture has also been improved.
The effect of trace vanadium addition on mechanical properties, microstructure and austenite phase characteristics in a 3.9% Al-Delta TRIP steel
Authors: Emamian Yaser , Kolahi Alireza , Palizdar Yahya , Sadeghpour Saeed
Published: September 2024

This study aimed to examine the effect of adding 0.12 wt% vanadium on the properties of delta TRIP steel through microstructural and mechanical investigations. The delta ferrite phase was observed in all annealing temperatures and samples. Carrying out bainitic transformation at 350 °C for 6, 10, and 15 min resulted in the stability of the austenite phase and the formation of ferritic bainite phase after heat treatment. The presence of vanadium led to the formation of MC precipitate phases and reduced the remaining austenite percentage from 14% to 6% by weight in the heat-treated sample. The low percentage of austenite in vanadium-containing steel has weakened the TRIP effect in strengthening. On the other hand, the presence of MC precipitates has compensated for the reduction in strength from the TRIP strengthening process through precipitation hardening and reducing the grain size of the delta ferrite phase. The resulting properties (UTS: 866 MPa and El: 41.3%) have led to the creation of a formability index of 35 GPa% in vanadium-containing steel, which is better than the mechanical properties (UTS: 857 MPa and El: 37.4%) and the formability index of vanadium-free steel (32 GPa%). These factors make this steel a suitable option for automotive industry applications. Based on these features make this steel a suitable candidate for automotive industries. Microstructural investigations revealed that the addition of vanadium reduces the grain size of the delta ferrite phase. Typically, the austenite phase forms around the ferritic bainite phase and delta ferrite grain boundaries. During tensile testing, it transforms into martensite through the TRIP process.
Insight into a new perspective on the complex propagation processes in networks: dynamic link equations
Authors: Song Jiahui , Gong Zaiwu
Published: September 2024

Insight into the spread of epidemics under different transmission mechanisms in networks has long been an important research question in the field of complex network dynamics. Currently, under simple transmission mechanisms, our analysis of the dynamic processes in networks starts only from the node level, considering the scale of infected nodes in the network. However, the information provided by this lowest-order approach to considering dynamic processes in networks is very limited. Most importantly, it is not applicable to the analysis of dynamic processes in networks under more common complex transmission mechanisms, as it neglects the interactions between nodes. Therefore, in this article, we propose a set of closed link dynamic equations to gain insight into complex propagation processes from a microscopic perspective. Fundamentally, we have developed a set of analytical tools for analyzing complex dynamic behaviors at the link level, enabling us to reexamine the complex dynamic processes on networks from a higher-order perspective. Additionally, we apply the proposed analytical framework to complex SIS epidemiological models on two real and synthetic networks, and extensive numerical simulation results demonstrate the feasibility and effectiveness of the proposed method.
Neutrino halo profiles: HR-DEMNUni simulation analysis
Authors: Hernández-Molinero Beatriz , Carbone Carmelita , Jimenez Raul , Garay Carlos Peña
Published: September 2024

Using the high-resolution HR-DEMNUni simulations, we computed neutrino profiles within virialized dark matter haloes. These new high-resolution simulations allowed us to revisit fitting formulas proposed in the literature and provided updated fitting parameters that extend to less massive haloes and lower neutrino masses than previously in the literature, in accordance with new cosmological limits. The trend we observe for low neutrino masses is that, for dark matter halo masses below ∼ 4 × 1014h-1M⊙, the presence of the core becomes weaker and the profile over the whole radius is closer to a simple power law. We also characterised the neutrino density profile dependence on the solid angle within clustered structures: a forward-backward asymmetry larger than 10% was found when comparing the density profiles from neutrinos along the direction of motion of cold dark matter particles within the same halo. In addition, we looked for neutrino wakes around halo centres produced by the peculiar motion of the halo itself. Our results suggest that the wakes effect is present in haloes with masses greater than 3 × 1014h-1M⊙where a mean displacement of 0.06h-1Mpc was found.
Radiating particles accelerated by a weakly charged Schwarzschild black hole
Authors: Juraev Bakhtinur , Stuchlík Zdeněk , Tursunov Arman , Kološ Martin
Published: September 2024

It is well known that supermassive black holes in the centers of galaxies are capable of
accelerating charged particles to very high energies. In many cases, the particle acceleration by
black holes occurs electromagnetically through an electric field induced by the source. In such
scenarios, the accelerated particles radiate electromagnetic waves, leading to the appearance of
the backreaction force, which can considerably change the dynamics, especially, if the particles
are relativistic. The effect of the radiation reaction force due to accelerating electric field of
the central body in curved spacetime has not been considered previously. We study the dynamics of
radiating charged particles in the field of the Schwarzschild black hole in the presence of an
electric field associated with a small central charge of negligible gravitational influence. We
use the DeWitt-Brehme equation and discuss the effect of the self-force, also known as the tail
term, within the given approach. We also study the pure effect of the self-force to calculate the
radiative deceleration of radially moving charged particles. In the case of bounded orbits, we
find that the radiation reaction force can stabilize and circularize the orbits of oscillating
charged particles by suppressing the oscillations or causing the particles to spiral down into the
black hole depending on the sign of the electrostatic interaction. In all cases, we calculate the
energy losses and exact trajectories of charged particles for different values and signs of
electric charge.
A power spectrum approach to the search for axion-like particles from resolved galaxy clusters using CMB as a backlight
Authors: Mehta Harsh , Mukherjee Suvodip
Published: September 2024

Axions or axion-like particles (ALPs) are hypothetical particles predicted by beyond standard model theories, which make one of the dark matter candidates. These particles can convert into photons and vice-versa in the presence of a magnetic field, with a probability decided by its coupling strength gaγ. One of the ways to detect these particles is by using the Cosmic Microwave Background (CMB) as a backlight. As the CMB photons pass through a galaxy cluster, they can get converted into ALPs in the mass range 10-15eV to 10-11eV through resonant conversion in the presence of cluster magnetic fields. This leads to a polarized spectral distortion (α-distortion) in the CMB as the photon polarization parallel to the magnetic field in the galaxy cluster is involved in the conversion. The fluctuations in the magnetic field and electron density in a galaxy cluster lead to spatially varyingα-distortion around the cluster, with a power spectrum that is different from the lensed E-mode and B-mode CMB polarization power spectrum for the standard model of cosmology. By measuring the difference in the polarization power spectrum around a galaxy cluster from the all-sky signal, one can find newα-distortion in the sky. For the resolved galaxy clusters, if the redshift, electron density, and magnetic field profiles of the cluster can be constrained using optical, X-ray, and radio observations, one can measure the coupling strength gaγfrom the ALP power spectrum. The contamination from CMB and galactic foregrounds such as synchrotron and dust can be mitigated by using multiple frequency bands by leveraging on the difference in the spectral shape of the signal from foregrounds. Using the ILC technique to clean the foregrounds, we show that the new power spectrum-based approach of the resolved galaxy clusters from upcoming CMB experiments such as Simons Observatory and CMB-S4 can detect (or put constraints) on the ALP-photon coupling strength of gaγ< 5.2 × 10-12GeV-1and gaγ< 3.6 × 10-12GeV-1at 95% C.I. respectively for ALPs of masses 10-13eV or for smaller gaγfor lighter ALP masses.
Back-side stress to ease p-MOSFET degradation on e-MRAM chips
Authors: Yu 于 Zhi-Meng 志猛 , Yang 杨 Xiao-Lei 晓蕾 , Zhao 赵 Xiao-Nan 晓楠 , Li 李 Yan-Jie 艳杰 , He 何 Shi-Kun 世坤 , Wang 王 Ye-Wu 业伍
Published: September 2024

The magnetoresistive random access memory process makes a great contribution to threshold voltage deterioration of metal–oxide–silicon field-effect transistors, especially on p-type devices. Herein, a method was proposed to reduce the threshold voltage degradation by utilizing back-side stress. Through the deposition of tensile material on the back side, positive charges generated by silicon–hydrogen bond breakage were inhibited, resulting in a potential reduction in threshold voltage shift by up to 20%. In addition, it was found that the method could only relieve silicon–hydrogen bond breakage physically, thus failing to provide a complete cure. However, it holds significant potential for applications where additional thermal budget is undesired. Furthermore, it was also concluded that the method used in this work is irreversible, with its effect sustained to the chip package phase, and it ensures competitive reliability of the resulting magnetic tunnel junction devices.
Freezing imaginarity of quantum states based on ℓ1-norm
Authors: Han 韩 Shuo 烁 , Zheng 郑 Bingke 冰轲 , Guo 郭 Zhihua 志华
Published: September 2024

We discuss freezing of quantum imaginarity based on ℓ
1-norm. Several properties about a quantity of imaginarity based on ℓ
1-norm are revealed. For a qubit (2-dimensional) system, we characterize the structure of real quantum operations that allow for freezing the quantity of imaginarity of any state. Furthermore, we characterize the structure of local real operations which can freeze the quantity of imaginarity of a class of N-qubit quantum states.
Design of superconducting compounds at lower pressure via intercalating XH4 molecules (X = B, C, and N) into fcc lattices
Authors: Zhao 赵 Yue 玥 , Liu 刘 Sihan 思涵 , Liu 刘 Jiao 骄 , Gu 顾 Tingting 婷婷 , Hao 郝 Jian 健 , Shi 石 Jingming 景明 , Cui 崔 Wenwen 文文 , Li 李 Yinwei 印威
Published: September 2024

Recently, many encouraging experimental advances have been achieved in ternary hydrides superconductors under high pressure. However, the extreme pressure required is indeed a challenge for practical application, which promotes a further exploration for high temperature (T
c) superconductors at relatively low pressure. Herein, we performed a systematic theoretical investigation on a series of ternary hydrides with stoichiometry AX
2H8, which is constructed by interacting molecular XH4 (X = B, C, and N) into the fcc metal A lattice under low pressure of 0–150 GPa. We uncovered five compounds which are dynamically stable below 100 GPa, e.g., AcB2H8 (25 GPa), LaB2H8 (40 GPa), RbC2H8 (40 GPa), CsC2H8 (60 GPa), and SrC2H8 (65 GPa). Among them, AcB2H8, which is energetically stable above 2.5 GPa, exhibits the highest T
c of 32 K at 25 GPa. The superconductivity originates mainly from the coupling between the electron of Ac atoms and the associated low-frequency phonons, distinct from the previous typical hydrides with H-derived superconductivity. Our results shed light on the future exploration of superconductivity among ternary compounds at low pressure.
A novel approach for the anomalous collectivity in neutron-deficient Os isotopes*
Authors: Teng 滕 Wei 威 , Zhang 张 Yu 宇 , Qi 亓 Chong 冲
Published: September 2024

An algebraic model with three-body boson interactions is proposed to incorporate the different quadrupole modes in nuclear collectivity. It is shown that the recently observed anomalous collective structure characterized by

and

, which cannot yet be explained by any other microscopic nuclear models, naturally emerges in the present model due to the inclusion of triaxial rotor modes. This description is further extended to describe odd-A nuclei by including the coupling to the Fermion degree of freedom. This allows us to give a unified explanation of the anomalous

strengths in both even-even and even-odd systems, which indicate different behaviors. As examples, the model is applied to describe the spectroscopy and

transition properties of

Os. All recent measurements of these isotopes can be well reproduced on the same footing, which suggests that the anomalous collectivity persists even in odd-A systems.
Systematic study of cross section for proton-induced reactions on neodymium up to 65 MeV using TALYS-1.96 code
Authors: Saha A.
Published: September 2024

A systematic study was conducted on the theoretical estimation of the nuclear cross sections of charged particle induced reactions on rare earth nuclei. The production cross sections of the 150,149,148,146,144,143,141Pm and 149,147Nd nuclei were calculated theoretically via proton induced reactions on neodymium using TALYS (version 1.96) code in the default mode, with different combinations of nuclear models as well as adjusted nuclear model parameters from the reaction threshold up to a proton energy of 65 MeV. The theoretically computed results were compared with the experimental results taken from the EXFOR database and literature reported by various research groups. Moreover, the effects of various level density models, preequilibrium models, optical model potentials, and gamma strength functions on the cross section calculation were considered. This theoretical analysis will help elucidate the theory of nuclear reaction models and improve the evaluated nuclear data libraries.
Continuous GPS PPP-AR frequency transfer links
Authors: Jian Bin , Gertsvolf Marina
Published: September 2024

In this paper, we show that the SPARK software of the Natural Resources Canada (NRCan) with their DCR (Decoupled Clock Rapid) products can be used to generate the PPP-AR continuous batch clock solutions of multiple days, which we use to build frequency transfer links between two remotely located GPS receivers. The reliability and confidence in forming the long-term frequency transfer links have been improved compared to Jian et al (2023 Metrologia
60 065002). We compare the SPARK PPP-AR links to an optical fiber and TWSTFT links for hundreds of days. The ~500-day-long comparisons with TWSTFT show no frequency bias for continental and cross-continental links. Frequency transfer links formed using the SPARK solutions have uncertainty of

1
×

10

−
15

/

T

, where T is in days, without reaching the noise floor, a critical requirement for comparing optical frequency standards and for the redefinition of the SI second. The short latency of the NRCan DCR products enables the quick availability of the PPP-AR links presented in this paper marking it particularly relevant for time sensitive applications.
Mechanical properties assessment of composite solid propellant based on different aziridine bonding agents
Authors: Eissa Mohamed F. , Maraden Ahmed , Mostafa Hosam E.
Published: September 2024

The employment of the dynamic mechanical analyzer (DMA) represents a modern methodology for the monitoring of the thermo-mechanical characteristics and also the thermomechanical loads of polyurethane-based composite solid rocket propellants during combustion. A meticulous preparation of composite propellant samples based on different bonding agents was carried out to examine the influence of various bonding agents on mechanical properties. To simulate the effects of natural aging, an accelerated aging program was implemented and subjected to the propellant samples for 5-day exposure at 90°C, equivalent to 5 years of natural aging. The dynamic mechanical modern analysis technique was used to assess the viscoelastic behavior and degree of viscoelasticity of both fresh and aged propellant samples. It is concluded that M4 based on MT-X bonding agent is the most valuable formulation of CSRP with tan δ of 0.183591, also with mechanical results; implying that M4 formulation based on MT-X bonding agent has the highest degree of viscoelasticity.
Design of small independent photovoltaic power generation system
Authors: Li Nan , Wang Jin , Zhang Yi
Published: September 2024

This article designs a small independent photovoltaic power generation system, which includes solar panels, controllers, batteries, and inverter modules. The design requirements and principles of boost converters and inverters were elaborated, and the inverters were simulated in Matlab; The fuzzy control method was selected to track the maximum power point, and its effectiveness was verified through MATLAB simulation; Corresponding methods have been proposed to prevent or reduce factors that affect the output power of photovoltaic arrays, such as power attenuation, shielding loss, and temperature rise loss. It has extremely important significance for promoting the development of photovoltaic power generation, achieving zero carbon goals, and sustainable development of human society.
Water, energy, and food nexus in a solar-powered brackish water desalination plant in Jordan
Authors: Bdour Ahmed , Al-Sadeq Noor , Gharaibeh Muna , Mendoza-Sammet Angeles , Salinas-Rodriguez Sergio G
Published: September 2024

The growing demand for water in domestic, agricultural, and energy production applications poses a significant challenge for Jordan. This work assesses the role of brackish water desalination as an alternative to alleviate water scarcity in semi-arid regions. Desalination is still limited in its application in Jordan due to high electricity tariffs. Shifting to renewable sources such as solar energy, abundant in the country, is a feasible way to power technologies with a high energy demand. In this work, we study the brackish water desalination plant at the Hashemite University in Jordan that is powered by a photovoltaic (PV) solar system (the HU PV-BWRO). The plant’s performance was evaluated in the context of the water-energy nexus as a hybrid water supply solution. While this work integrates essential elements, such as water availability, technical options, economic viability, and agricultural management, the analysis primarily focuses on the technical and economic aspects related to water, energy, and food. Water assessment results indicate that the groundwater wells near the HU campus are at risk of quality degradation over time, as they have shown a slight increasing trend in salinization from 2015 to 2023. Energy assessment results show a promising performance from the HU PV-BWRO desalination plant, with a specific energy consumption (SEC) value of 1.2 kWh m−3 (140% to 400% less energy consumption compared with other Jordanian desalination plants of similar capacity). Unit price comparisons indicate that the energy cost of PV (0.042 USD/m3) is 5 times less than the cost of grid electricity (0.24 USD/m3). The operational cost of the solar desalination plant at full capacity, is USD 0.23/m3. This is about 260% less than the operation cost for local, grid-powered desalination plants. Finally, it is estimated that by operating the plant at 50% of its total capacity, the produced water could be sufficient to irrigate up to 80% of the HU campus to increase agricultural production. This study highlights the importance of decreasing reliance on energy for water and food production, and it shows that the use of solar powered desalination could be used as an example in semi-arid regions, particularly in terms of integrating renewable energy and energy efficiency.
Microstructural analysis on the compatibility of various dilution oils on magnetorheological grease performance
Authors: Pang Zheng Bin , Mazlan Saiful Amri , Ubaidillah Ubaidillah , Nordin Nur Azmah , Mohamad Norzilawati , Johari Mohd Aidy Faizal , Mohd Yusuf Shahir Yasin , Ahmad Khairi Muntaz Hana , Abdul Aziz Siti Aishah
Published: September 2024

This research explores the effects of dilution oils on the storage stability of magnetorheological grease (MRG) by studying the effect of dilution oil viscosity on the microstructure of carrier fluids medium for MRG, which can help address practical challenges encountered in the development and deployment of MRG. Three samples of MRG with 70 wt% CIP are prepared; a control, and 2 samples diluted until 10 wt% hydraulic fluid and kerosene respectively. The resulting samples were analysed using a modular compact rheometer (MCR) for oscillatory strain sweep and rotational current sweep. Rheological analyses were repeated after one year in storage. Fourier-Transform Infrared (FTIR) spectroscopy and Atomic Force Microscopy (AFM) results show significant microstructural and performance deterioration of grease thickener in the sample with kerosene, which concludes that kerosene had a very significant effect on the degradation of the grease thickener. From this study, it was revealed that low viscosity oils disrupt the reconstruction of the thickener of lithium grease, which in turn causes deteriorating shear rheological performance of MRG at off-state conditions. This comprehensive analysis explains the relationships between MRG composition, microstructural characteristics, and performance parameters, offering a foundational framework for further exploration and advancement in this scientific field.
Multi response optimization of process parameters in titanium alloy minimum quantity lubrication drilling operation
Authors: Dalke Piyush A , Karanjkar Atul V , Wankhede Pankaj
Published: September 2024

This work investigates the application of minimal quantity lubrication (MQL) in the drilling process, where a combination of liquid and air creates an aerosol in the form of a fine mist. This protective layer decreases friction and tool wear, hence improving overall efficiency. The study examines the conventional Gulfcut oil blend drilling technique to enhance drilling performance on the titanium alloy Ti-6Al-4V under MQL circumstances. The key drilling parameters, namely spindle speed (N), feed rate (F), and point angle (D), were analyzed using a Taguchi L16 orthogonal array. The experimental inquiry aimed to identify the most favorable conditions that lead to the least amount of torque (TQ), thrust force (TF), and surface roughness (SR). An Analysis of Variance (ANOVA) was used to examine the impact of control factors on drilling performance. The optimized drilling parameters led to a reduction in torque, thrust force, and surface roughness by 12.88%, 21.29%, and 25.76%, respectively. Furthermore, microstructure analysis demonstrated that the Gulfcut lubricant plays a pivotal role in reducing grain size during drilling. This research provides valuable insights into optimizing drilling conditions for titanium alloy using a conventional Gulfcut oil blend with MQL, aiming to reduce torque, thrust force, and surface roughness.
Analysis of disturbance factors of magnetorheological damper in continuous impact buffer system
Authors: Wang Xin , Hou Minjie , Ouyang Qing , Xu Xiao , Yu Zhen , Cheng Yuzhu , Li Zhaochun
Published: September 2024

Magnetorheological (MR) impact buffering systems are widely used in vehicle suspensions, bridge damping, and aircraft landing gear due to their excellent buffering performance and rapid response time. However, under the condition of high-speed continuous impact, magnetorheological damper (MRD) operate in complex environments where various internal and external uncertainties can negatively affect control performance. This paper analyzes the impact of disturbance signals on MR buffering systems and explores control strategies to mitigate these effects. First, we established a hysteresis model based on experimental data and identified parameters using a genetic algorithm to determine the influence of hysteresis disturbances. Next, we developed a temperature model based on the thermal characteristics of SG-MRF2035 magnetorheological fluid, fitting the relationship between temperature and dynamic viscosity to identify temperature disturbances. The results showed that when disturbances were considered, the system exhibited higher peak damping forces and a deviation from the desired ‘platform effect’ in the damping force-displacement relationship. Finally, we applied an Active Disturbance Rejection Control(ADRC) strategy, which effectively compensated for the hysteresis and temperature disturbances, enhancing the system’s robustness. Compared to PID control, the ADRC-controlled system demonstrated lower peak damping forces and a damping force-displacement relationship closer to the desired platform effect.
Influential mechanism of operational parameters on internal resonance of drill strings by numerical simulations
Authors: Li Xinye , Li Mingming , Guo Xiaoqiang , Agila Wassef , Zhang Huabiao , Yang Jie
Published: September 2024

Drill string vibration is highly conductive to drill string fatigue and component failure. In this study, a finite element model of a drill string with bottom hole assembly (BHA) is constructed to investigate the effect of different operational parameters, such as different string length, density, pressure, and velocity of drilling fluid on drill string natural frequencies, and thus internal resonance by considering fluid-structure interaction (FSI) in ANSYS. Numerical simulations demonstrate that the natural frequencies decrease as the length of the drill string increases, which is especially true for the axial mode. The condition of 1:1 internal resonance between the axial and torsional modes only occurs when the length of drill string is sufficiently high. Nevertheless, this resonance fades away in the presence of fluid. The increment of fluid density slightly increases the natural frequency in lateral mode, whereas decreases that in axial mode. On the other hand, this effect of density is negligible in the torsional mode. The natural frequencies for axial, torsional and lateral modes decrease as the fluid velocity increases, and the impact of fluid pressure on natural frequency is almost not observable. The numerical results for the case without drill fluid are in qualitative agreement with analytical solutions. when considing the effect of drill length on natural frequency.
Distance preserving machine learning for uncertainty aware accelerator capacitance predictions
Authors: Goldenberg Steven , Schram Malachi , Rajput Kishansingh , Britton Thomas , Pappas Chris , Lu Dan , Walden Jared , Radaideh Majdi I , Cousineau Sarah , Harave Sudarshan
Published: September 2024

Accurate uncertainty estimations are essential for producing reliable machine learning models, especially in safety-critical applications such as accelerator systems. Gaussian process models are generally regarded as the gold standard for this task; however, they can struggle with large, high-dimensional datasets. Combining deep neural networks with Gaussian process approximation techniques has shown promising results, but dimensionality reduction through standard deep neural network layers is not guaranteed to maintain the distance information necessary for Gaussian process models. We build on previous work by comparing the use of the singular value decomposition against a spectral-normalized dense layer as a feature extractor for a deep neural Gaussian process approximation model and apply it to a capacitance prediction problem for the High Voltage Converter Modulators in the Oak Ridge Spallation Neutron Source. Our model shows improved distance preservation and predicts in-distribution capacitance values with less than 1% error.
A comparison of deep learning models for proton background rejection with the AMS electromagnetic calorimeter
Authors: Hashmani R K , Akbas E , Demirköz M B
Published: September 2024

The alpha magnetic spectrometer (AMS) is a high-precision particle detector onboard the International Space Station containing six different subdetectors. The transition radiation detector and electromagnetic calorimeter (ECAL) are used to separate electrons/positrons from the abundant cosmic-ray proton background. The positron flux measured in space by AMS falls with a power law which unexpectedly softens above 25 GeV and then hardens above 280 GeV. Several theoretical models try to explain these phenomena, and a more accurate measurement of positrons at higher energies is needed to help test them. The currently used methods to reject the proton background at high energies involve extrapolating shower features from the ECAL to use as inputs for boosted decision tree and likelihood classifiers. We present a new approach for particle identification with the AMS ECAL using deep learning (DL). By taking the energy deposition within all the ECAL cells as an input and treating them as pixels in an image-like format, we train an MLP, a CNN, and multiple ResNets and convolutional vision transformers (CvTs) as shower classifiers. Proton rejection performance is evaluated using Monte Carlo (MC) events and ISS data separately. For MC, using events with a reconstructed energy between 0.2–2 TeV, at 90% electron accuracy, the proton rejection power of our CvT model is more than five times that of the other DL models. Similarly, for ISS data with a reconstructed energy between 50–70 GeV, the proton rejection power of our CvT model is more than 2.5 times that of the other DL models.
Local accommodation energy efficiency in Lisbon: a red flag for tourism, indoor thermal comfort, and energy renovation targets
Authors: Valente Inês , Fernandes Bárbara , César André , Menezes Laura , Gouveia João Pedro
Published: September 2024

Climate change affects all sectors of society, and tourism is no exception. Adaptation in this sector is challenging because of its vulnerability to rapid change and uncertainties of an environmental and political nature. Local accommodation (LA) (short-term rentals) plays a key role in the Portuguese economy and is, thus, potentially a key driver of increased energy efficiency and promoting buildings decarbonization, thereby contributing both to climate change adaptation and mitigation of this sector. However, there is limited research on energy efficiency and climate change resilience in the LA sector. To address this research gap, this study focuses on four civil parishes situated in the historic center of Lisbon, Portugal. Using a multidimensional approach and cross-sectoral datasets, we assessed the energy efficiency of LA in Lisbon and explored the cost of renovation measures. This analysis exposed poor energy performance in LA buildings and a low frequency of buildings with thermal insulation or double-glazed windows. Despite this, energy performance in the LA sector was comparatively better than in the residential sector. Additionally, LA s are equipped with more heating and cooling systems than the broader residential sector. This knowledge is relevant for researchers and policymakers, contributing to developing sustainable tourism approaches and reaching the objectives outlined in energy renovation policies.
RAD51 regulates eukaryotic chromatin motions in the absence of DNA damage
Authors: Maarouf Amine , Iqbal Fadil , Sanaullah Sarvath , Locatelli Maëlle , Atanasiu Andrew T. , Kolbin Daniel , Hommais Chloé , Mühlemann Joëlle K. , Bonin Keith , Bloom Kerry , Liu Jing , Vidi Pierre-Alexandre
Published: September 2024

In yeasts and higher eukaryotes, chromatin motions may be tuned to genomic functions, with transcriptional activation and the DNA damage response both leading to profound changes in chromatin dynamics. The RAD51 recombinase is a key mediator of chromatin mobility following DNA damage. As functions of RAD51 beyond DNA repair are being discovered, we asked whether RAD51 modulates chromatin dynamics in the absence of DNA damage and found that inhibition or depletion of RAD51 alters chromatin motions in undamaged cells. Inhibition of RAD51 increased nucleosome clustering. Predictions from polymer models are that chromatin clusters reduce chain mobility and, indeed, we measured reduced motion of individual chromatin loci in cells treated with a RAD51 inhibitor. This effect was conserved in mammalian cells, yeasts, and plant cells. In contrast, RAD51 depletion or inhibition increased global chromatin motions at the microscale. The results uncover a role for RAD51 in regulating local and global chromatin dynamics independently from DNA damage and highlight the importance of considering different physical scales when studying chromatin dynamics.
Advances in forest restoration management and technology
Authors: Stanturf John A , Dumroese R Kasten , Elliott Stephen , Ivetic Vladan , Khokthong Watit , Kleine Michael , Lang Mait , Löf Magnus , Madsen Palle , Prescott Cindy , Young Timothy
Published: September 2024

Forest landscape restoration is a participatory process for setting objectives that should be explicitly stated and recognize the needs of local communities. Restoration technology should be appropriate to site and landscape conditions as well as socioeconomic and cultural contexts. This chapter focuses on establishing forests where they are currently lacking. The techniques discussed can also establish trees outside of forests or restore degraded forests. Topics include understanding and documenting initial conditions and monitoring outcomes. Passive regeneration techniques include natural regeneration, sometimes with assistance. Active techniques addressed cover direct seeding by hand or drones and planting. Quality plant material is critical to achieve adequate seedling survival; we survey advanced methods of genomics, molecular genetics, genetic engineering, and genome editing. Other topics include seed collection and seed orchards, nursery practices, seed zones, assisted migration, and planting designs. Site modification techniques considered are conventional mechanical site preparation, micro-catchments, mulching, water-absorbing gels, and biostimulants.