bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancing in full-color single-pixel imaging: integrating variable density sampling with hyper-Laplacian priors
Authors: Lv Shun , Tang Tianhang , Chen Jie , Shi Xuelei , Liu Yiguang
Published: March 2024

Full-color single-pixel imaging aims to restore chromatic images using a single detector element, such as a photodiode or a single-pixel camera. However, image quality is inevitably compromised at low sampling rates due to inefficient sampling methods or incomplete representation of spectrum information. To address these challenges, we meticulously consider the distribution of the image frequency spectrum and the correlation between multiple bands and make further improvements in sampling strategy and reconstruction methods. First, we propose a variable density random sampling strategy based on the exponential distribution to enhance image sampling efficiency. Second, we discover that in most cases, there exists a hyper-Laplacian distribution between spectral mixed images and monochromatic images. Building upon this observation, we designed a hyper-Laplacian prior and seamlessly integrated it into our reconstruction method to enhance the performance of full-color images. Experimental results demonstrate that our method significantly improves the quality of reconstructed full-color images compared to state-of-the-art methods.
Multi-axis fields boost SABRE hyperpolarization
Authors: Lindale Jacob R. , Smith Loren L. , Mammen Mathew W. , Eriksson Shannon L. , Everhart Lucas M. , Warren Warren S.
Published: March 2024

The inherently low signal-to-noise ratio of NMR and MRI is now being addressed by hyperpolarization methods. For example, iridium-based catalysts that reversibly bind both parahydrogen and ligands in solution can hyperpolarize protons (SABRE) or heteronuclei (X-SABRE) on a wide variety of ligands, using a complex interplay of spin dynamics and chemical exchange processes, with common signal enhancements between 10
3
and 10
4
. This does not approach obvious theoretical limits, and further enhancement would be valuable in many applications (such as imaging mM concentration species in vivo). Most SABRE/X-SABRE implementations require far lower fields (μT-mT) than standard magnetic resonance (>1T), and this gives an additional degree of freedom: the ability to fully modulate fields in three dimensions. However, this has been underexplored because the standard simplifying theoretical assumptions in magnetic resonance need to be revisited. Here, we take a different approach, an evolutionary strategy algorithm for numerical optimization, multi-axis computer-aided heteronuclear transfer enhancement for SABRE (MACHETE-SABRE). We find nonintuitive but highly efficient multiaxial pulse sequences which experimentally can produce a sevenfold improvement in polarization over continuous excitation. This approach optimizes polarization differently than traditional methods, thus gaining extra efficiency.
The GTPase activating protein Gyp7 regulates Rab7/Ypt7 activity on late endosomes
Authors: Füllbrunn Nadia , Nicastro Raffaele , Mari Muriel , Griffith Janice , Herrmann Eric , Rasche René , Borchers Ann-Christin , Auffarth Kathrin , Kümmel Daniel , Reggiori Fulvio , De Virgilio Claudio , Langemeyer Lars , Ungermann Christian
Published: March 2024

Organelles of the endomembrane system contain Rab GTPases as identity markers. Their localization is determined by guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs). It remains largely unclear how these regulators are specifically targeted to organelles and how their activity is regulated. Here, we focus on the GAP Gyp7, which acts on the Rab7-like Ypt7 protein in yeast, and surprisingly observe the protein exclusively in puncta proximal to the vacuole. Mistargeting of Gyp7 to the vacuole strongly affects vacuole morphology, suggesting that endosomal localization is needed for function. In agreement, efficient endolysosomal transport requires Gyp7. In vitro assays reveal that Gyp7 requires a distinct lipid environment for membrane binding and activity. Overexpression of Gyp7 concentrates Ypt7 in late endosomes and results in resistance to rapamycin, an inhibitor of the target of rapamycin complex 1 (TORC1), suggesting that these late endosomes are signaling endosomes. We postulate that Gyp7 is part of regulatory machinery involved in late endosome function.
The evaluation for plasma noise in arbitrary time-delay interferometry combinations
Authors: Zhao Xin-Lei , Wang Pan-Pan , Shao Cheng-Gang
Published: March 2024

The laser interferometer space antenna (LISA) uses laser interferometry to measure gravitational wave-induced distance changes between freely falling test masses on separate spacecraft. In practice, the space-borne gravitational wave detector operates in a plasma medium, and subsequently, the variations in electron density affect the refractive index and add displacement noise to measurements. Geometric time-delay interferometry (TDI) is the TDI combinations searched by geometric method, which is employed to mitigate overwhelming laser phase noise. This study explores all forty-five second-generation geometric TDI combinations up to sixteen links, analyzing plasma noise effects via power spectral density and cross-spectral density calculations for different optical links. Our findings reveal that plasma noise can exceed the noise floor, which comprises optical metrology system and test mass acceleration noise, in certain low-frequency regions due to different noise transfer behaviors. Further, we establish electron density requirements for various TDI combinations, showing that densities below

100

cm

−
3

/

Hz

 

@

 
10

mHz

satisfy LISA’s criteria across all forty-five combinations. This allows for optimized TDI selection based on specific plasma densities.
Muon-induced nuclear magnetic moments in spinless muonic atoms: a simple estimate
Authors: Beyer K A , Oreshkina N S
Published: March 2024

In an attempt to address the long-standing fine-structure puzzle in heavy muonic atoms we investigate the magnetic interaction between a nucleus and its bound muon. A simple estimate shows that the effect is only noticeable for unrealistic nuclear parameters. A further investigation as to the relation of this effect to nuclear polarisation (NP) identifies the interaction as the magnetic dipole part of NP. Motivated by the relative closeness of this simple estimate to rigorous evaluations of NP, we extract effective values for the nuclear magnetic polarisability, a quantity otherwise unknown for all but the lightest nuclei.
Optical and dielectric properties of divalent copper based double perovskite compound, Gd2CuTiO6
Authors: Saha Papiya , Nithya R , Sarguna R M , Sen Sujoy
Published: March 2024

In this work, we have investigated high temperature dielectric properties and room temperature optical properties on rare earth ion based orthorhombic Gd2CuTiO6 (GCTO). Optical properties like reflectance and band gap were determined from ultra-violet visible (UV–Vis) diffuse reflectance spectroscopy technique and photoluminescence (PL) spectrum. The compound exhibited substantial optical absorption and emission in the visible region. Our findings reveal the presence of an intermediate band, as evidenced by the difference between the band gap values obtained from the Tauc plot using the diffuse reflectance spectrum (3.07 eV) and the PL spectrum (2.4 eV). Furthermore, thermogravimetric analysis demonstrated high thermal stability with <0.4% change in mass over a wide temperature range of 30 °C–1200 °C in air environment. Moreover, lead-halide free compound, GCTO is highly thermally stable oxide double perovskite with wide band gap and absorption in the UV–Vis range are highly suitable for optical applications In addition, dielectric properties of the compound have been examined using impedance spectroscopy as a function of frequency ranging from 500 Hz to 1 MHz and temperature between 300 K and 550 K. Compounds with relaxor behaviour at high temperatures and high thermal stability are desired for several applications. Because of the cation disorders present in this compound, GCTO displays dielectric relaxor behaviour indicative of a distribution of relaxation times. Furthermore, the frequency-dependent modulus illustrated a thermally activated conduction mechanism. Cole–Cole plots of electrical modulus suggest prominent grain contribution above 350 K.
Predicting treatment plan approval probability for high-dose-rate brachytherapy of cervical cancer using adversarial deep learning
Authors: Gao Yin , Gonzalez Yesenia , Nwachukwu Chika , Albuquerque Kevin , Jia Xun
Published: March 2024

Objective. Predicting the probability of having the plan approved by the physician is important for automatic treatment planning. Driven by the mathematical foundation of deep learning that can use a deep neural network to represent functions accurately and flexibly, we developed a deep-learning framework that learns the probability of plan approval for cervical cancer high-dose-rate brachytherapy (HDRBT). Approach. The system consisted of a dose prediction network (DPN) and a plan-approval probability network (PPN). DPN predicts organs at risk (OAR) D
2cc
and CTV D
90% of the current fraction from the patient’s current anatomy and prescription dose of HDRBT. PPN outputs the probability of a given plan being acceptable to the physician based on the patients anatomy and the total dose combining HDRBT and external beam radiotherapy sessions. Training of the networks was achieved by first training them separately for a good initialization, and then jointly via an adversarial process. We collected approved treatment plans of 248 treatment fractions from 63 patients. Among them, 216 plans from 54 patients were employed in a four-fold cross validation study, and the remaining 32 plans from other 9 patients were saved for independent testing. Main results. DPN predicted equivalent dose of 2 Gy for bladder, rectum, sigmoid D
2cc
and CTV D
90% with a relative error of 11.51% ± 6.92%, 8.23% ± 5.75%, 7.12% ± 6.00%, and 10.16% ± 10.42%, respectively. In a task that differentiates clinically approved plans and disapproved plans generated by perturbing doses in ground truth approved plans by 20%, PPN achieved accuracy, sensitivity, specificity, and area under the curve 0.70, 0.74, 0.65, and 0.74. Significance. We demonstrated the feasibility of developing a novel deep-learning framework that predicts a probability of plan approval for HDRBT of cervical cancer, which is an essential component in automatic treatment planning.
A cardiac MRI motion artifact reduction method based on edge enhancement network
Authors: Jiang Nanhe , Zhang Yucun , Li Qun , Fu Xianbin , Fang Dongqing
Published: March 2024

Cardiac magnetic resonance imaging (MRI) usually requires a long acquisition time. The movement of the patients during MRI acquisition will produce image artifacts. Previous studies have shown that clear MR image texture edges are of great significance for pathological diagnosis. In this paper, a motion artifact reduction method for cardiac MRI based on edge enhancement network is proposed. Firstly, the four-plane normal vector adaptive fractional differential mask is applied to extract the edge features of blurred images. The four-plane normal vector method can reduce the noise information in the edge feature maps. The adaptive fractional order is selected according to the normal mean gradient and the local Gaussian curvature entropy of the images. Secondly, the extracted edge feature maps and blurred images are input into the de-artifact network. In this network, the edge fusion feature extraction network and the edge fusion transformer network are specially designed. The former combines the edge feature maps with the fuzzy feature maps to extract the edge feature information. The latter combines the edge attention network and the fuzzy attention network, which can focus on the blurred image edges. Finally, extensive experiments show that the proposed method can obtain higher peak signal-to-noise ratio and structural similarity index measure compared to state-of-art methods. The de-artifact images have clear texture edges.
Combining quantitative and qualitative analysis for scoring pleural line in lung ultrasound
Authors: Xing Wenyu , He Chao , Ma Yebo , Liu Yiman , Zhu Zhibin , Li Qingli , Li Wenfang , Chen Jiangang , Ta Dean
Published: March 2024

Objective. Accurate assessment of pleural line is crucial for the application of lung ultrasound (LUS) in monitoring lung diseases, thereby aim of this study is to develop a quantitative and qualitative analysis method for pleural line. Approach. The novel cascaded deep learning model based on convolution and multilayer perceptron was proposed to locate and segment the pleural line in LUS images, whose results were applied for quantitative analysis of textural and morphological features, respectively. By using gray-level co-occurrence matrix and self-designed statistical methods, eight textural and three morphological features were generated to characterize the pleural lines. Furthermore, the machine learning-based classifiers were employed to qualitatively evaluate the lesion degree of pleural line in LUS images. Main results. We prospectively evaluated 3770 LUS images acquired from 31 pneumonia patients. Experimental results demonstrated that the proposed pleural line extraction and evaluation methods all have good performance, with dice and accuracy of 0.87 and 94.47%, respectively, and the comparison with previous methods found statistical significance (P < 0.001 for all). Meanwhile, the generalization verification proved the feasibility of the proposed method in multiple data scenarios. Significance. The proposed method has great application potential for assessment of pleural line in LUS images and aiding lung disease diagnosis and treatment.
A recurrence model capturing interface traps for non-zero bandgap GFETs towards dynamic mimicking of synaptic plasticity
Authors: Chandrasekar L , Raja Shaik Rameez , Rajakumari V , Pradhan K P
Published: March 2024

This paper primarily focusses on developing an analytical model with a non-zero bandgap of boron (B)/nitrogen (N) substitution doped graphene field-effect transistors (GFETs) to mimic the synaptic behaviour. The trap charges at the channel and gate-insulator interface are utilized to induce the hysteresis conduction mechanism, which is further exploited to accomplish synaptic plasticity. The proposed recurrence, that is the time-dependent trap drain current model, accurately captures the physical insights of trap charges using an equivalent metal–insulator–graphene model. An interesting feature of the proposed model is that it is compatible with both the doped (B/N) and the undoped GFETs. The model is also investigated to generate the hysteresis characteristics of the GFET that are further utilized to simulate the synaptic behaviour. Another fact that must be noticed is the existence of complete OFF regions for doped B/N GFETs, unlike the undoped case, which manifest undesirable ambipolar behaviour. The synapse made up of B/N-doped GFETs predicts an optimistic learning and memory mechanism, termed as spike time-dependent plasticity (STDP). The STDP characteristics of B/N doped synaptic GFETs have been enhanced by more than 18 × compared to artificial synapses made of undoped GFETs. Hence, the hysteresis behaviour along with the non-zero bandgap of B/N substitution doped GFETs makes them highly favourable for the dynamic mimicking of synaptic plasticity to be efficiently biologically plausible.
Energy-based modeling of rate-independent hysteresis and viscoelastic effects in dielectric elastomer actuators
Authors: Rizzello Gianluca
Published: March 2024

Dielectric elastomer (DE) transducers are known to exhibit a rate-dependent hysteresis in their force-displacement response, which is commonly attributed to the viscoelastic behavior of elastomer materials and compliant electrodes. In the case of DE materials characterized by low mechanical losses, such as silicone, the mechanical hysteresis often turns out to be practically rate-independent in the low frequency range (sub-Hz), whereas rate-dependent hysteretic effects only become relevant at higher deformation rates. Most of the existing literature focuses on describing DE hysteretic losses using viscoelasticity theory. This approach results in relatively simple dynamic models, which are not capable of describing rate-independent hysteretic behaviors. In this work, we propose a control-oriented modeling framework for both rate-dependent and rate-dependent hysteresis occurring in uniaxially loaded DE actuators. To this end, classic thermodinamically-consistent modeling approaches for DEs are combined with a new energy-based Maxwell-Lion formalization of the hysteretic losses. The resulting dynamic model comprises a set of nonlinear ordinary differential equations, and is capable of simultaneously describe geometric dependencies, large deformation nonlinearities, electro-mechanical coupling, and rate-independent and rate-dependent hysteretic effects. To deal with the large number of involved parameters, a novel systematic identification algorithm based on quadratic programming is also proposed. After presenting the theory, the model is validated based on experiments conducted on a silicone-based rolled DE actuator. Its superiority compared to classic DE viscoelastic models is quantitatively assessed.
A novel variable stiffness soft gripper based on air-quicksand: design, analysis, and validation
Authors: Weirui Liu , Jingrun Zhao , Hui Yang , Xingjun Gao , Jiaqi Liu , Wenbo Liu
Published: March 2024

This paper presents a novel variable stiffness soft gripper based on the principle of air-quicksand to enhance both the grasping stability and load-bearing capacity. The design, fabrication, and testing experiments of the soft grippers were performed. The soft finger is composed of a variable stiffness layer and a pneumatically driven layer with variable height chambers. The concept behind the variable stiffness layer lies in the fact that when the chamber is filled with air, it forms a suspended quicksand configuration through laminar flow and turbulence. This arrangement increases the spacing between sand particles, leading to reduced friction. Moreover, the stiffness and hardness of the soft finger can be controlled by adjusting the pressure. To improve the grasping stability, the variable height chambers were designed to provide power, which also increased the contact area. Experimental results demonstrate that the variable stiffness layer can be softened when in contact with fragile objects, thus protecting the surface without causing any damage. The stiffness increases to provide sufficient grasping force for holding objects firmly after the inflation is stopped. The exceptional performance exhibited by this gripper design holds significant potential for various applications, such as industrial sorting and fruit picking.
A smart structural optimization method of magnetorheological damper for ultra-precision machine tool
Authors: Wang Qiyu , Shen Yurui , Li Weihua , Liu Xinhua , Gołdasz Janusz , Deng Lei , Królczyk Grzegorz , Li Zhixiong
Published: March 2024

To address the problem of multi-source vibration in ultra-precision machine tools, a vibration reduction stand was designed by replacing passive damping components with magnetorheological dampers (MRDs). In this work, the structural parameters of MRDs were optimized using an improved pelican optimization algorithm (IPOA) to realize the maximum capability in reducing vibration. Firstly, the working principle of MRDs was explained, and the mathematical models of MRDs were established. Then, an IPOA based on singer chaotic mapping, nonlinear inertia weight factor, and Cauchy mutation strategy was proposed to enhance the global search capability and convergence efficiency of the algorithm. Subsequently, the IPOA was applied to optimize key structural parameters of MRDs, including output damping force, controllable damping range, response time, and power consumption. Finally, COMSOL Multiphysics software was used to verify the effectiveness of the proposed algorithm by comparing the magnetic induction intensity distribution of MRDs before and after optimization, as well as the variation of the four performance indexes under the different applied currents. After being optimized using the proposed IPOA, the MRDs can deliver a larger maximum damping force and a wider damping controllable range, with less power consumption and quick response, which could meet the requirement for vibration suppression of ultra-precision machine tools.
Target search in the CRISPR/Cas9 system: facilitated diffusion with target cues
Authors: Lu (路桥) Qiao , Pigolotti Simone
Published: March 2024

We study how Cas9, a central component of the CRISPR/Cas9 system, searches for a target sequence on the DNA. We propose a model that includes as key ingredients 3D diffusion, 1D sliding along the DNA, and the effect of short binding sequences preceding the target (protospacer adjacent motifs—PAMs). This last aspect constitutes the main difference with traditional facilitated diffusion of transcription factors. We solve our model, obtaining an expression for the average search time of Cas9 for its target. We find that experimentally measured kinetic parameters are close to the values yielding an optimal search time. Our results rationalize the role of PAMs in guiding the search process, and show that Cas9 searches for its targets in a nearly optimal way.
Optimal quantum control of charging quantum batteries
Authors: Rodríguez R R , Ahmadi B , Suárez G , Mazurek P , Barzanjeh S , Horodecki P
Published: March 2024

Quantum control allows us to address the problem of engineering quantum dynamics for special purposes. While recently the field of quantum batteries has attracted much attention, optimization of their charging has not benefited from the quantum control methods. Here we fill this gap by using an optimization method. We apply for the first time the convergent iterative method for the control of the population of a bipartite quantum system in two cases, starting with a qubit-qubit case. The quantum charger-battery system is considered here, where the energy is pumped into the charger by an external classical electromagnetic field. Secondly, we systematically extend our investigation to a second case involving two harmonic oscillators in the Gaussian regime, presenting an original formulation of the method. In both cases, the charger is considered to be an open dissipative system, as its interaction with the drive may require a more pronounced exposure to general interaction with environment. A key consideration in our optimization strategy is the practical concern of turning the charging external field on and off. We find that optimizing the pulse shape yields a substantial enhancement in both the power and efficiency of the charging process compared to a sinusoidal drive. The harmonic oscillator configuration of quantum batteries is particularly intriguing, as the optimal driving pulse remains effective regardless of the environmental temperature. This study introduces a novel approach to quantum battery charging optimization, opening avenues for enhanced performance in real-world applications.
q-Deformed quantum mechanics related to the Tamm-Dancoff oscillator algebra and some physical applications
Authors: Chung W S , Algin A
Published: March 2024

In this paper, we consider a system of the q-deformed bosonic Tamm-Dancoff oscillators, whose spectrum has some exponential cutoff factors at high energies. We first investigate the q-calculus in the Tamm-Dancoff (TD) boson algebra, and within this framework, the q-derivative, q-integral and q-exponential function are introduced. Using these properties, we construct a new formalism for the q-deformed quantum mechanics, which accordingly involve the q-adjoint operator and the q-Hermitian operator properties. We then derive the q-deformed Heisenberg relation, and develop the q-Hermitian momentum operator. The q-deformed Schrödinger equation is introduced, and as applications, we study the momentum eigenfunction and one-dimensional box problem. Another application of the TD type deformation onto lattice oscillations is also discussed through a model of the q-deformed Debye solid. Finally, other potential applications of the TD-oscillators gas model are concisely pointed out.
The impact of anisotropy on neutron star properties: insights from 𝖨–𝖿–𝖢 universal relations
Authors: Mohanty Sailesh Ranjan , Ghosh Sayantan , Routaray Pinku , Das H.C. , Kumar Bharat
Published: March 2024

Anisotropy in pressure within a star emerges from exotic internal processes. In this study, we incorporate pressure anisotropy using the Quasi-Local model. Macroscopic properties, including mass (M), radius (R), compactness (C), dimensionless tidal deformability (Λ), the moment of inertia (I), and oscillation frequency (f), are explored for the anisotropic neutron star. Magnitudes of these properties are notably influenced by anisotropy degree. Universal I–f–C relations for anisotropic stars are explored in this study. The analysis encompasses various EOS types, spanning from relativistic to non-relativistic regimes. Results show the relation becomes robust for positive anisotropy, weakening with negative anisotropy. The distribution of f-mode across M–R parameter space as obtained with the help of C–f relation was analyzed for different anisotropic cases. Using tidal deformability data from GW170817 and GW190814 events, a theoretical limit for canonical f-mode frequency is established for isotropic and anisotropic neutron stars. For isotropic case, canonical f-mode frequency for GW170817 event is f
1.4 = 2.606+0.457
-0.484kHz; for GW190814 event, it is f
1.4 = 2.097+0.124
-0.149kHz. These relationships can serve as reliable tools for constraining nuclear matter EOS when relevant observables are measured.
Energy-dependent flavour ratios in neutrino telescopes from charm
Authors: Bhattacharya Atri , Enberg Rikard , Reno Mary Hall , Sarcevic Ina
Published: March 2024

The origin of the observed diffuse neutrino flux is not yet known.
Studies of the relative flavour content of the neutrino flux detected at Earth
can give information on the production mechanisms at the sources and on flavour
mixing, complementary to measurements of the spectral index and normalization.
Here we demonstrate the effects of neutrino fluxes with different spectral
shapes and different initial flavour compositions dominating at different
energies, and we study the sensitivity of future measurements with the IceCube
Neutrino Observatory. Where one kind of flux gives way to another, this shows
up as a non-trivial energy dependence in the flavour compositions. We explore
this in the context of slow-jet supernovae and magnetar-driven supernovae — two
examples of astrophysical sources where charm production may be effective.
Using current best-fit neutrino mixing parameters and the projected 2040
IceCube uncertainties, we use event ratios of different event morphologies at
IceCube to illustrate the possibilities of distinguishing the energy dependence
of neutrino flavour ratios.
Hysteresis phenomenon in single electron nonlinear Thomson scattering in tightly focused linearly polarized lasers caused by collision position changes
Authors: Zeng Mingjing , Zhang Yangyi , Chang Yifan , Yu Zekai , Tian Youwei
Published: March 2024

The collision between high-energy electrons and linearly polarized laser pulses is systematically studied, which has significant application value. The effect of different laser parameters on the spectrum and power angular distribution has been analyzed. The maximum transverse amplitude of the electron motion track changes as one moves farther away from the focal point acting as the electronic initial position. Concurrently, an extensive examination of the off-axis properties of the electron is carried out. As the form of scattering changes from linear to nonlinear, the angular radiation of its power distribution exhibits intriguing characteristics. We found the ‘hysteresis’ phenomenon of the radiation characteristics. Our research can serve as a useful resource for comprehending and using laser electron interactions.
Goos–Hänchen shifts in a V-type three-level atomic system interacting with squeezed vacuum
Authors: Zeng HaiPeng , Ma Aijie
Published: March 2024

This study explores the Goos–Hänchen (GH) shift phenomenon within a cavity hosting a V-type three-level atomic system, engaged with two independent broadband squeezed baths. Our exploration encompasses a thorough analysis of the lateral shifts in both reflected and transmitted light beams, with a focus on the impact of critical factors, i.e, coupling field strength, incoherent pumping field strength, and squeezed vacuum intensity. Our results reveal an interplay of these parameters, resulting in distinctive negative and positive GH shifts in both reflected and transmitted light. In addition, a remarkable enhancement of GH shifts at specific angles of incidence is observed, presenting a wide-ranging modulation across diverse system parameters. This study not only enriches the understanding of the GH shift in complex atomic systems but also highlights the potential for the manipulation of these lateral shifts by fine-tuning key variables of the system, and contributes valuable insights to the broader field of optical phenomena in quantum systems.
Quantum discord and its dynamics for multipartite systems
Authors: Luo 罗 Jiaxin 嘉欣 , Guo 郭 Qiong 琼
Published: March 2024

Quantum discord, one of the famous quantum correlations, has been recently generalized to multipartite systems by Radhakrishnan et al. Here we give analytical solutions of the quantum discord for a family of N-qubit quantum states. For the bipartite system, we derive a zero quantum discord which will remain unchanged under the phase damping channel. For multiparitite systems, it is found that the quantum discord can be classified into three categories and the quantum discord for odd-partite systems can exhibit freezing under the phase damping channel, while the freezing does not exist in the even-partite systems.
Robust optical mode converter based on topological waveguide arrays
Authors: Xu 徐 Yu-Xiang 宇翔 , Tang 唐 Wen-Jian 文剑 , Jiang 姜 Li-Wei 力炜 , Wu 吴 De-Xing 德兴 , Wang 王 Heng 恒 , Xu 许 Bing-Cong 冰聪 , Chen 陈 Lin 林
Published: March 2024

Optical mode converters are essential for enhancing the capacity of optical communication systems. However, fabrication errors restrict the further improvement of conventional mode converters. To address this challenge, we have designed an on-chip TE0–TE1 mode converter based on topologically protected waveguide arrays. The simulation results demonstrate that the converter exhibits a mode coupling efficiency of 93.5% near 1550 nm and can tolerate a relative fabrication error of 30%. Our design approach can be extended to enhance the robustness for other integrated photonic devices, beneficial for future development of optical network systems.
Possible Habitats for NH3, NH2D, H13CN, HC15N, SO, and C18O in the Initial Conditions of High-mass Star Formation
Authors: Cui Quan-Ling , Zhang Chuan-Peng , Wang Jun-Jie
Published: March 2024

The initial condition of high-mass star formation is a complex area of study because of the high densities (

n

H

2

>

10

6

cm−3) and low temperatures (T
dust < 18 K) involved. Under such conditions, many molecules become depleted from the gas phase by freezing out onto dust grains. However, the N-bearing and deuterated species could remain gaseous under these extreme conditions, suggesting that they may serve as ideal tracers. In this paper, using the Plateau de Bure Interferometer and Very Large Array observations at 1.3 mm, 3.5 mm, and 1.3 cm, we investigate the possible habitats for NH3, NH2D, H13CN, HC15N, SO, and C18O in eight massive precluster and protocluster clumps G18.17, G18.21, G23.97N, G23.98, G23.44, G23.97S, G25.38, and G25.71. We found that the NH3 cores are in good agreement with the 3.5 mm peak emission, but the NH3 is much more extended than the 3.5 mm emission structure. The SO distributions agree well with the 3.5 mm peaks for the evolved star formation stage, but we did not detect any SO emission in the four earliest star formation sources. C18O is a poor tracer in conditions of the cold (≲18 K) and dense (≳104 cm−3) cores, e.g., the prestellar cores. We also found that the NH2D cores are mainly located in the temperature range of 13.0–20.0 K, and the NH2D lines may be strongly depleted above 20 K.
New energy transmission line fault location method based on Pearson correlation coefficient
Authors: Pan Zhongfeng , Xu Daming , Zhang Yibo , Wang Minzhen , Wang Zhuang , Yu Jiang , Zhang Guangxin
Published: March 2024

The access of new energy power source makes the traditional transmission line structure become complex, and due to the influence of power electronic device control strategy, the fault characteristics have been fundamentally changed, resulting in the traditional transmission line fault localization method can not be applied to the new energy sending line. To address the above problems, this paper analyzes the transient current characteristics of different power supply faults, and learns that there are obvious differences in the transient currents on both sides of the fault point inside and outside the transmission line area, and then proposes a new energy transmission line fault localization method based on the Pearson correlation coefficient, which determines the fault location by calculating the correlation coefficients of the fault waveforms of the neighboring monitoring points. Finally, comparative experiments are carried out under different fault types and fault locations to further verify the applicability of the proposed method.
Adaptive defogging method for transmission line inspection images based on multilayer perceptual fusion
Authors: Zhang Yilin , Yang Haiwei , Xu Yongsheng , Leng Bingbing , Wang Zeyi , Yu Honghai , Gao GuangMin , Wang Ziming , Wen Changzhe
Published: March 2024

Existing image defogging methods generally have problems such as incomplete defogging and color distortion. To address this problem, this paper proposes an adaptive defogging method for transmission line images based on multilayer perceptual fusion, which uses dynamic convolution, dense residuals, and attention mechanism to design an adaptive feature enhancement network containing six Dy-namic Residual Components (DRC) and two Dy-namic Skip-Connected Feature Fusion Component (DSCFF) composed of adaptive feature enhancement network, which prevents the problem of features being forgotten in the early stage of the network, and enhances the expressive ability of the model. For the decoding network, the de-fogging effect of the model is further strengthened by introducing a decoder module based on the SOS enhancement model, and finally, by comparing the experiments with the current de-fogging methods with more advanced performance, the results show that the method has good de-fogging effect and can retain the image details better with high color retention.
Genetic Algorithm Based on Opposite Chromosome Multiple Genetic Operations Combined with Task Load Balancing
Authors: Zhu Ying , Peng Liang
Published: March 2024

A collaborative optimization method for task allocation and path planning in multi-UAV execution of multi-objective cooperative inspection tasks is proposed. The method is based on the Opposite Genetic Algorithms (OGA), which combines the actual task completion time with the balance of UAV inspection flight time, fault downtime, and maximum-minimum time load. A Task Balancing Opposite Chromosome Multiple Mutation Operator Genetic Algorithm (TOMGA) is introduced to solve the task load balancing problem by optimizing the task allocation among multiple UAVs with time as the optimization objective. Simulation results demonstrate that, this algorithm can effectively allocate inspection tasks to UAVs and generate initial flight routes. It resolves the issue of task load imbalance, improves the rationality of task allocation, enhances convergence speed, and overcomes the problem of local optima.
Following the money: climate adaptation finance in the Marshall Islands
Authors: Incerti Nina , Barnett Jon
Published: March 2024

The significant body of research on the distribution of international finance for climate change adaptation shows that it is not well correlated to the vulnerability of countries. Vulnerability differs greatly within countries as well, yet very few studies examine subnational flows of adaptation finance. Here, we present evidence of the subnational allocation of international adaptation finance within the Republic of the Marshall Islands (RMI). The RMI is a highly salient case as it is a small island developing state comprised solely of low-lying atolls that is both in need of and a recipient of adaptation finance. We describe patterns of adaptation finance in the RMI between 2015 and 2019 based on analysis of a comprehensive government database of bilateral and multilateral aid projects. We find that flows of adaptation finance were heavily skewed towards a small number of large-scale civil works projects in urban areas funded by multilateral institutions. Rural areas attracted smaller scale projects funded largely by bilateral donors. The overall distribution of adaptation finance across islands is highly sporadic, with hotspots of activity and areas of neglect. Our results suggest the allocation of adaptation finance to the RMI is insufficient relative to needs, poorly coordinated, and fails to reach places where it is most needed.
Enhancing biogas yield of Xyris capensis grass using different nanoparticles additive
Authors: Olatunji K O , Madyira D M , Rasmeni Z Z
Published: March 2024

To enhance the efficiency of the anaerobic digestion process of lignocellulose feedstocks, there is a need for appropriate pretreatment methods. The influence of nanoparticles additive on biogas yield of new novel Xyris capensis grass as biogas feedstock was investigated. A laboratory-batch experiment was set up at mesophilic conditions (37 ± 2° C) to study the biogas production potential of Xyris capensis, and different nanoparticles were added as a means of pretreatment. 20 mg/L of Fe3O4, 1.4 mg/L of CuO, 10 mg/L of ZnO, and 10 mg/L of MgO were added to the anaerobic digestion process, and their influence on biogas and methane yield was compared with the untreated substrate. Biogas yield of 376.67, 156.86, 175.34, 190.00, and 290.00 mL/g VSadded was recorded for Fe3O4, CuO, ZnO, MgO additives, and untreated substrate, respectively, while methane yield of 282.50, 156.86, 97.66, 116.33, and 198.51 mLCH4/g VSadded were observed, respectively. It can be observed that only 20 mg/L of Fe3O4 increased biogas and methane yields by 29.89 and 42.31%, respectively.
Chemical, Thermogravimetric and Elemental Characterization of Nigerian Groundnut and Cowpea Shells for Sustainable Valorization
Authors: Mary Onyelucheya Chioma , Tagbo Nwabanne Joseph , Olawale Daramola Michael , Ayodele Iwarere Samuel
Published: March 2024

In this study, the chemical, thermogravimetric, and elemental composition of Nigerian groundnut (Arachis hypogaea L.) and cowpea shells (Vigna unguiculata) were investigated to understand their potential as valuable waste resources. Analysis of the carbohydrates and lignin content was performed using the National Renewable Energy Laboratory method. Fourier transform infrared (FTIR) spectroscopy was used to determine the chemical structure of the substrates. Elemental analysis was performed using X-ray fluorescence (XRF) and an elemental analyzer to determine the carbon, hydrogen, nitrogen, and sulphur. In addition, thermogravimetric analysis was used to assess the thermal stability of the substrates. The chemical composition analysis revealed that the cowpea shells contain 21.32% cellulose, 21.46% hemicellulose, and 28.37% lignin. On the other hand, groundnut shells comprise 26.31% cellulose, 19.5% hemicellulose, and 38.33% lignin. The XRF results indicated the presence of significant elemental compositions in both substrates, including Si, Al, Mg, Na, P, Fe, K, Ca, and S. The carbon content of both substrates was found to be 43%. Thermogravimetric analysis revealed that groundnut shells exhibit a higher cellulose decomposition temperature at 350 °C, whereas cowpea shells manifest this phenomenon at 322 °C. The results show that the cowpea shells had a higher heating value as they exceeded that of the groundnut shell by 0.89 per cent. These comprehensive findings show the substantial potential of Nigerian groundnut and cowpea shells as valuable waste materials, which can be effectively used to produce valuable products such as bioethanol, biochemicals, biochar, and bio-composite materials. This research contributes to understanding the composition and properties of these agricultural by-products, thus paving the way for their sustainable use in various industrial applications.
Review on Invention of Hybrid Solar panel using Nano particles for High Efficiency Energy
Authors: Ojo A. O. , Adaramola B. A. , Afolalu S. A. , Monye S. I. , Yussouff A. A. , Adeyemi A. G.
Published: March 2024

Identification and exploitation of alternative renewable energy sources is important in meeting the rising energy challenge globally. Solar energy is one source of energy which has been earmarked as a promising renewable energy source that will play a better role in reducing the depletion of the existing source of energy. Thus, the use of photovoltaic panels and technologies to fulfill the current energy requirement as well as reducing the carbon emission appears very possible. To this end, the study reviewed the possibilities of improving the hybrid solar panel via nano additive addition to improve its thermal efficiency. From the study, it was established that nano additives have the capacity lessen the surface temperature experienced by the panel and hence helped in the enhancement conversion of energy into power as well as improving the overall efficiency of the panel. This study provides insights for driving the sustainability of solar energy as a renewable energy source.
Influence of Cellulose-Cellulase Enzyme Digestibility in the Production of Glucose from Lignocellulosic Biomass Waste
Authors: Ndukwe N A , Idika D I , Okiei W O
Published: March 2024

A comprehensive understanding of the factors and ability of cellulase enzyme to completely hydrolyze the structural lignocellulosic biomass has been a major research focus over the years. A comparative analysis of cellulose-cellulase digestibility of Kraft-pretreated sawdust from twenty different Nigeria wood wastes was carried out with increasing enzyme (Trichorderma viride) loading of 0.4 mg cm−3, 1.0 mg cm−3, 2.0 mg cm−3, and 4.0 mg cm−3 at constant substrate application of 10 mg cm−3 biomass concentration, temperature of 40°C and 2 h incubation period. This was carried out in order to establish the optimum cellulase-cellulose ratio for maximum biodegradation of the lignocellulosic biomass to produce glucose, a fermentable sugar. The influence of the cellulose-cellulase interaction from 0.4 mg cm−3 to 1.0 mg cm−3 enzyme treatment resulted in 144% increase in glucose yield from E. suaveolen and 121% from S. pustlatas. while 2.0 mg cm−3 cellulase concentration gave 674%, 641% and 617% increase from E.suaveolen, H. ciliate and A. germinans respectively. A general trend of increasing sugar formation was observed with an increasing enzyme loading due to enhanced cellulose accessibility by the cellulase enzyme leading to effective saccharification of the lignocellulosic materials for more sugar production. However, further increase of 4.0 mg cm−3 enzyme concentration failed to produce a commiserate amount of fermentable sugar.
Study of the Characteristics of Polyurethane as a Sustainable Material used for Buildings, Polymer Composite, Biomedical, and Electronics Application
Authors: Okokpujie I.P. , Monye S.I. , Subair R.E. , Abiodun C.J. , Monye N.S. , Osueke C.O.
Published: March 2024

This research is focused on studying the characteristics of Polyurethane in engineering applications as a sustainable material employed for buildings and as reinforcement for polymer composite, electronics, and biomedical applications. This study discussed and reviewed papers cut across the Polyurethane Formation, Engineering Attributes of Polyurethane, and Polyurethane Applications in various fields such as Buildings, Polymer Composite Materials, Biomedical, and Electronic, which has proven that Polyurethane is a multi-functional material that has been employed in biomedical engineering used for tissue, wound treatment, breast implant, drug delivery systems. Also, it has been applied for sensors, actuators, Flexible electronics, Energy harvesters and storage, and Shape memory applications. Furthermore, its application in buildings, Polyurethane (PU) foam as an insulation material embedded in the aluminium roofing system for sustainable human comfort. This study also identifies the challenges of Polyurethane and provides sustainable solutions. In conclusion, site materials and structural application have shown excellent performance from studying the Polyurethane characteristics as embedded materials for roofing sheets.
Study of Corrosion, Wear, and Thermal Analysis of Materials for Internal Combustion Engines and their Compatibility: A Review
Authors: Okokpujie I.P. , Ojo A.O. , Adaramola B.A. , Oladimeji M. , Ogundele R.I. , Abiodun C.J.
Published: March 2024

Several types of research have been carried out on using alternative biofuel in internal combustion engines to salvage the depletion of fossil fuels. While most of these studies focused on the emission characteristics and control of global warming, little attention has been given to the corrosion, wear, thermal behaviour, and compatibility of the internal combustion engine materials to biodiesel. Thus, this study focused on the various corrosion and wear mechanisms associated with the internal combustion engine components like piston and cylinder heads, as well as the thermal behaviour efficiencies of the engine after interaction with the biodiesel fuels. The review cut across the wear study of internal combustion engine materials in varying fuel environments. Thermal analysis of different materials applied for internal combustion engines for sustainable fuel media. Corrosion study of various materials employed in the application of ICE engines. Also, the study discusses some significant challenges related to the compatibility of ICE with biodiesel and gaseous fuels. The study’s outcome indicates that an adequate fuel blend with nano additives can help improve the combustion process, emission reduction, and thermal efficiency of the internal combustion engine components. Furthermore, practical design in the internal combustion engine components like pistons will help compatibility with the material in the biodiesel blends, thus reducing wear, corrosion, and other failures associated with the internal combustion engine.