bluuebunny/crossref_metadata_2025 huggingface dataset:
Measuring Quantum Geometric Tensor of Non-Abelian System in Superconducting Circuits
Authors: Zheng Wen , Xu Jianwen , Ma Zhuang , Li Yong , Dong Yuqian , Zhang Yu , Wang Xiaohan , Sun Guozhu , Wu Peiheng , Zhao Jie , Li Shaoxiong , Lan Dong , Tan Xinsheng , Yu Yang
Published: August 2022

Topology played an important role in physics research during the last few decades. In particular, the quantum geometric tensor that provides local information about topological properties has attracted much attention. It will reveal interesting topological properties but have not been measured in non-Abelian systems. Here, we use a four-qubit quantum system in superconducting circuits to construct a degenerate Hamiltonian with parametric modulation. By manipulating the Hamiltonian with periodic drivings, we simulate the Bernevig–Hughes–Zhang model and obtain the quantum geometric tensor from interference oscillation. In addition, we reveal its topological feature by extracting the topological invariant, demonstrating an effective protocol for quantum simulation of a non-Abelian system.
Possible unconventional order parameter in single crystals of SrPt3P superconductor
Authors: Cho Kyuil , Teknowijoyo S , Ghimire S , Krenkel E H , Tanatar M A , Zhigadlo N D , Kong S , Kovnir K , Prozorov R
Published: August 2022

Anisotropic properties of single crystals of SrPt3P were studied using London penetration depth and electrical resistivity measurements. The upper critical field,

H

c
2

(
T
)

, was determined from four-probe electrical resistivity measurements for three orthogonal directions of a magnetic field with respect to the crystal. The London penetration depth,

λ
(
T
)

, was determined from the magnetic susceptibility of the Meissner–London state measured using a tunnel-diode resonator technique. Whereas

H

c
2

(
T
)

and the normal-state

ρ
(
T
)

are practically identical for all three magnetic field orientations, the London penetration depth shows significant unidirectional anisotropy. The low-temperature

λ
(
T
)

is exponentially attenuated when a small excitation radiofrequency magnetic field, H

rf
, is applied along the

c

′
′

-direction, in which case screening currents flow in the

a

′
′

b

′
′

-plane, while for the other two orientations,

H

r
f

∥

a

′
′

and

H

r
f

∥

b

′
′

, the London penetration depth shows a much stronger,

λ
(
T
)
∼

T

2

, variation. Such unusual and contrasting behavior of the two anisotropies,

γ

H

T

=

H

c
2
,
a
b

/

H

c
2
,
c

=

ξ

a
b

/

ξ

c

and

γ

λ

T

=

λ

c

/

λ

a
b

, imposes significant constraints on the possible order parameter. Although our measurements are insufficient to derive conclusively the superconducting gap anisotropy, the order parameter with two point nodes and a modulation in the perpendicular direction is qualitatively consistent with the experimental observations.
A trajectory similarity-based method to evaluate GNSS kinematic precise positioning performance with a case study
Authors: Li Siqi , Chen Qijin , Niu Xiaoji , Fan Jing
Published: August 2022

There is a lack of effective testing methods to evaluate high-precision global navigation satellite system (GNSS) kinematic positioning solutions, such as GNSS real-time kinematic (RTK) or post-processed kinematic (PPK), with centimeter-level accuracy. Current methods either process static GNSS data in kinematic mode to perform a pseudo-kinematic test or use a precise motion table to make a real-kinematic test but within a very limited travel distance. This study proposes a trajectory similarity method by moving a track trolley platform along a railway track, which can match the GNSS positioning trajectory and the pre-surveyed reference track. The GNSS trajectory offsets from the reference track along the cross-track and vertical directions are regarded as GNSS kinematic positioning errors. Lever-arm compensation is applied to achieve millimeter-level accuracy for this evaluation method. A case study was conducted to evaluate the positioning performance of the Global Positioning System/BeiDou Navigation Satellite System (GPS/BDS) PPK using the proposed method. The results indicate that the proposed method can provide a reference trajectory on the order of a few millimeters, which is sufficiently accurate even for PPK positioning performance evaluation and error source tracing in wide regions. In this case, cycle slips as small as 10 cm in the carrier phase measurements can be detected and studied based on the proposed method.
Aerosol processing technique for the synthesis of mixed-phase copper on carbon catalyst: insights into CO2 adsorption and photocatalytic activity
Authors: Subedi Nabin , Mesceriakovas Arunas , Pham Khai , Heponiemi Anne , Karhunen Tommi , Saarinen Jarkko J , Lassi Ulla , Lähde Anna
Published: August 2022

In this study, spray pyrolysis; an aerosol processing technique was utilized to produce a mixed-phase copper on carbon (Cu/Cu
x
O@C) catalyst. The catalyst production was performed via chemical reduction of copper nitrate by a reducing sugar, i.e. glucose, using aqueous solution. The physical and chemical properties of the produced particles was assessed using various characterization techniques. The synthesis temperature had pronounced effect on the final particles. Since CO2 adsorption onto the catalyst is an important step in catalytic CO2 reduction processes, it was studied using thermogravimetric and temperature programmed desorption techniques. Additionally, photocatalytic activity of the particles was evaluated by gas-phase oxidation of acetylene gas which revealed excellent activity under both UV and visible light irradiation indicating the possible use of wider range of the solar spectrum.
Towards ballistic transport CVD graphene by controlled removal of polymer residues
Authors: Duan Tianbo , Li Hu , Papadakis Raffaello , Leifer Klaus
Published: August 2022

Polymer-assisted wet transfer of chemical vapor deposited (CVD) graphene has achieved great success towards the true potential for large-scale electronic applications, while the lack of an efficient polymer removal method has been regarded as a crucial factor for realizing high carrier mobility in graphene devices. Hereby, we report an efficient and facile method to clean polymer residues on graphene surface by merely employing solvent mixture of isopropanol (IPA) and water (H2O). Raman spectroscopy shows an intact crystal structure of graphene after treatment, and the x-ray photoelectron spectroscopy indicates a significant decrease in the C–O and C=O bond signals, which is mainly attributed to the removal of polymer residues and further confirmed by subsequent atomic force microscopy analysis. More importantly, our gated measurements demonstrate that the proposed approach has resulted in a 3-fold increase of the carrier mobility in CVD graphene with the electron mobility close to 10 000 cm2 V−1 S−1, corresponding to an electron mean free path beyond 100 nm. This intrigues the promising application for this novel method in achieving ballistic transport for CVD graphene devices.
A do-it-yourself Czerny–Turner spectrometer: atomic emission, absorption, reflection and fluorescence spectroscopy in natural sciences
Authors: Osterheider Mattis , Bourdon Bjoern , Boettcher Rasmus , Beeken Marco , Imlau Mirco
Published: August 2022

Spectrometers play a decisive role in the education of A-level and/or under-graduate students in the field of natural sciences. They are capable to demonstrate atomic emission, transmission, reflection and fluorescence spectra, but can be used for wavelength filtering, as well. Here, we present a do-it-yourself spectrometer setup based on a Czerny–Turner design that (a) can be used for all measurement types with one and the same setup and (b) is capable to spectrally resolve atomic emission lines. We use LEGO® bricks for the optomechanical construction and combine it with affordable, but high-quality optical components and linear array based on a charge-coupled device (CCD). A modular design is implemented and allows for a quick change between the various measurement techniques, but also fosters the technological understanding of the underlying systems’ optical design.
Fisher matrix for the angular power spectrum of multi-tracer galaxy surveys
Authors: Abramo L. Raul , Dinarte Ferri João Vitor , Tashiro Ian Lucas , Loureiro Arthur
Published: August 2022

Redshift evolution and peculiar velocities break the isotropy of cosmological surveys with respect to the directions parallel and transverse to the line of sight, limiting the accuracy of the Fourier representation to small areas and redshift ranges.
In contrast to the Fourier space power spectrum, the full information about the two-point function of tracers of large-scale structure is encapsulated in the redshift-dependent angular power spectrum Cij
ℓ
(zi
,zj
) for the tracer species i and j at the redshift slices zi
and zj
, expressed in harmonic space.
In this paper we derive semi-analytical expressions for the multi-tracer Fisher matrix of angular power spectra, in real and in redshift space, which are exact in the linear regime of structure formation.
Our expressions can be used to forecast the constraining power of galaxy surveys with many tracers and a large number of redshift slices, for which the derivation of the Fisher matrix from numerically evaluated covariance matrices may not be feasible or practical.
Controlling optical lateral shifts in a monolayer graphene system
Authors: Mohammed Amjed Qasim , Fahim Fatima Safaa , Lafta Holya A , Abbass Rathab , Kadhim Athmar Ali , Shams Marwah A , Adhab Ayat Hussein
Published: August 2022

In this letter, we have studied the optical lateral shifts of transmitted and reflected lights in a defect structure doped by a single layer of graphene nanostructure. For adapting the optical features of the lateral shifts, we have first studied the refractive index properties of the defect layer. We have studied the conditions for achieving the negative and positive refractive index of the graphene monolayer system. After that, we have discussed the optical lateral shifts of the reflected and transmitted light beams when the refractive index of the graphene nanostructure become positive or negative, respectively. We have found that the enhanced lateral shifts for reflected and transmitted lights may be possible for a positive refractive index. For the negative refractive index, we have realized that simultaneous negative or positive lateral shifts are possible for the reflected and transmitted light beams. In our proposed scheme, the lateral shifts at the fixed incident angle are possible only by tuning the optical parameters without needing to change the cavity structure.
A thresholding method based on society modularity and role division for functional connectivity analysis
Authors: Li Jianxiu , Chen Junhao , Zhang Zihao , Hao Yanrong , Li Xiaowei , Hu Bin
Published: August 2022

Objective. Inferring the optimized and sparse network structure from the fully connected matrix is a key step in functional connectivity (FC) analysis. However, it is still an urgent problem to be solved, how to exclude the weak and spurious connections contained in functional networks objectively. Most existing binarization methods assume that the network has some certain constraint structures, which lead to changes in the original topology of the network. Approach. To solve this problem, we develop a Trade-off Model between Cost and Topology under Role Division (MCT), which consists of three crucial strategies, including modularity detection, definition of node role, and E-cost optimization algorithm. This algorithm weighs the physical cost and adaptive value of the network while preserving the network structure. Reliability and validity of MCT were evaluated by comparing different binarization methods (efficiency cost optimization, cluster-span threshold, threshold method, and MCT) on synthetic and real data sets. Main results. Experiment results demonstrated that the recovery rate of MCT for networks under noise interference is superior to other methods. In addition, brain networks filtered with MCT had higher network efficiency and shorter characteristic path length, which is more in line with the small world characteristics. Finally, applying MCT to resting-state electroencephalography data from patients with major depression reveals abnormal topology of the patients’ connectivity networks, manifested as lower clustering coefficient (CC) and higher global efficiency (GE). Significance. This study provides an objective method for complex network analysis, which may contribute to the future of FC research.
Processive and distributive non-equilibrium networks discriminate in alternate limits
Authors: Venkataraman Gaurav G , Miska Eric A , Jordan David J
Published: August 2022

We study biochemical reaction networks capable of product discrimination inspired by biological proofreading mechanisms. At equilibrium, product discrimination, the selective formation of a ‘correct’ product with respect to an ‘incorrect product’, is fundamentally limited by the free energy difference between the two products. However, biological systems often far exceed this limit, by using discriminatory networks that expend free energy to maintain non-equilibrium steady states. Non-equilibrium systems are notoriously difficult to analyze and no systematic methods exist for determining parameter regimes which maximize discrimination. Here we introduce a measure that can be computed directly from the biochemical rate constants which provides a condition for proofreading in a broad class of models, making it a useful objective function for optimizing discrimination schemes. Our results suggest that this measure is related to whether a network is processive or distributive. Processive networks are those that have a single dominant pathway for reaction progression, such as a protein complex that must be assembled sequentially. While distributive networks are those that have many effective pathways from the reactant to the product state; e.g. a protein complex in which the subunits can associate in any order. Non-equilibrium systems can discriminate using either binding energy (energetic) differences or activation energy (kinetic) differences. In both cases, proofreading is optimal when dissipation is maximized. In this work, we show that for a general class of proofreading networks, energetic discrimination requires processivity and kinetic discrimination requiring distributivity. Optimal discrimination thus requires both maximizing dissipation and being in the correct processive/distributive limit. Sometimes, adjusting a single rate may put these requirements in opposition and in these cases, the error may be a non-monotonic function of that rate. This provides an explanation for the observation that the error is a non-monotonic function of the irreversible drive in the original proofreading scheme of Hopfield and Ninio. Finally, we introduce mixed networks, in which one product is favored energetically and the other kinetically. In such networks, sensitive product switching can be achieved simply by spending free energy to drive the network toward either the processive limit or the distributive limit. Biologically, this corresponds to the ability to select between products by driving a single reaction without network fine tuning. This may be used to explore alternate product spaces in challenging environments.
Replicated entanglement negativity for disjoint intervals in the Ising conformal field theory
Authors: Rockwood Gavin
Published: August 2022

We calculate the N interval replicated negativity for the Ising conformal field theory using correlation functions of branch point twist fields. For some subset P ⊂ N, this is a calculation of

Tr

(

ρ

A

T

P

)

n

where n is the replica index. This can be reformulated as a calculation of partition functions over superelliptic Riemann surfaces, and for the models in question, this partition function can be expressed in terms of the period matrix of this surface. We detail how to construct the period matrices for these surfaces, giving an analytic expression for

Tr

(

ρ

A

T

P

)

n

. The results are expressed such that when P = Ø, which corresponds to calculating the Rényi entropy, the formulas aligns with known results for the N interval Rényi entropy.
The Extinction Time Probability Distribution: Some Empirical Experiments
Authors: Al-Azzawi Hussein F.
Published: August 2022

The aim is to calculate the parametric and nonparametric probability distribution of the time until extinction for two stochastic predator-prey models namely the Rosenzweig-Macarthur and May models. We assume a climate variability parameterrto change in value each year. The amplitude of the variableris a normally distributed random variable truncated to the closed interval [r1,r2]. Two such intervals are used with two different values of variance for the normal distribution. Simulation is used to generate the data for each case and the data is analyzed to obtain the best fit probability distribution.
The Independent Incompatible Edges Topology on Di-graphs
Authors: Ali Iman Abbas , Hassan Asmhan Flieh
Published: August 2022

This sheet offers a novel topology for di-graphs termed independent incompatible edges topology, which creates the topology from the edges set 𝕶 for whatever di-graph. On edges 𝕶, a family of sub-basis is used for build the independent incompatible edges topology. After that, we look at assorted properties; explore the Independent Incompatible Edge Topology on some types of di-graphs. In addition, this topology’s some initial results were studied. Our objective is to understand several aspects of any di-graph using it is corresponding independent incompatible edges topology, the topology that is discussed in this paper.
Fractional Variational iteration Method for Solving Fractional Order Shoreline Moving Boundary Value Problem
Authors: Nama Adnan Yassean , Fadhel Fadhel Subhi
Published: August 2022

In this article, the mathematical model of shoreline problem will be presented, which includes Caputo sense space-time fractional order derivative. The solution to this problem would be an approximate solution using fractional variational iteration method (FVIM). Graphically the results will be compared with an exact solution to the integer order derivatives. Three cases are discussed, time fractional, space fractional and standard diffusion problem.
Application of the Generalized Backstepping Control Method for Lotka-Volterra Prey-Predator System with Constant Time Delay
Authors: Ghaffar Mayadah Khalil , Fadhel Fadhel S. , Arif Nabeel E.
Published: August 2022

A well-known method, namely the backstepping method, which is used for stabilizing systems of ordinary differential equations is applied in this paper to solve the system of Lotka-Volterra prey-predator with time delay. The followed approach is accomplished with the cooperation of the method of steps, which is a well-known approach followed in solving delay differential equations, to transform the system of nonlinear delay differential equations into an equivalent system of ordinary differential equations. The fundamental concept behind the backstepping method is to construct recursively Lyapunov functions in quadratic form to stabilize the system for each time step interval. Matlab computer software is used to carry out the numerical simulation in order to investigate the effectiveness of the followed approach.
Some Results of a Harmonic Family of Analytic Functions Connected with Poisson Distribution Series
Authors: Dhayea Husamuldeen I , Juma Abdul Rahman S
Published: August 2022

This article aims to gain implicit relations among different subclasses of harmonic family of analytic functions containing with some description for Poisson distribution series to be in the new subclasses of harmonic convex functions and harmonic starlike, 𝒦𝒲(α) andUW*(α)respectively, in the plane.
Color Image Encryption Based on New Integral Transform SEE
Authors: Kuffi Emad A. , Mehdi Sadiq A. , Mansour Eman A.
Published: August 2022

Due to the worldwide expansion of the internet, the consumption and transmission of multimedia materials have risen significantly. This growth in demand necessitated a corresponding increase in data security measures. This work investigates encryption technology and proposes a novel color picture encryption and decryption approach based on the “SEE transform” developed by Sadiq, Emad, and Eman. We used the SEE transform to encrypt the original image, and the corresponding inverse SEE transform for decryption. The SEE transform has been performed to enhance the security of the encryption method. After using the SEE transform, we show that the suggested method considerably improves security measures and immunity to attacks, as demonstrated by comprehensive experiments and statistical analysis.
Study of Quotient Property Topologically
Authors: Manfe Riyam K. , Abed Majid Mohammed
Published: August 2022

In this article, our focus on the notion of quotient related to topology of some structure algebra several results and generalizations of topological quotient algebra have been given. We investigate some facts about quotient ring and quotient module topological especially when we have product of quotient ring and modules. One pf the results R/I. is a topological ring (TR), as we established. Also some results about topological submodule and topological module was introduced. Finally; some definitions and examples have been presented.
On measure relatively to fuzzy σ–algebra
Authors: Ahmed Ibrahim S. , Ebrahim Hassan H.
Published: August 2022

In this work we introduce and study some concepts relatively to fuzzy σ–algebra such as measure, countably additive, complete measure and extension of measure. Moreover, we present some of their basic properties and examples of them. In addition, it is shown that the linear combination of measure relatively to fuzzy σ–algebra is a measure too. Finally, the relationships between the proposed concepts have been introduced.
The Schwarz inequality and the Harnack’s Theorem For A (z) – Analytical Function
Authors: Qasim Jaafar Jabbar , Radhi Ahmed khalaf
Published: August 2022

This article discusses the theory fundamental theorems of A (z) – analytic functions and establishes analogies for Schwarz inequality as well as Harnack’s theorem for A(z) – analytic functions.
Maximum Likelihood Estimates and a survival function for fuzzy data for the Weibull-Pareto parameters
Authors: Abdalrazaq Abdallah Salah , Batah Feras Sh. M.
Published: August 2022

In this work, we discuss the estimation parameters and the reliability function for Weibull –Pareto distribution by maximum likelihood method. For that we used two iterative approximation techniques called “Newton-Raphson (NR)” and “Fisher’s Scoring (FS) method” when the available data is in the form of fuzzy numbers. The parameters’ and reliability function’s estimates are numerically contrasted using a Monte-Carlo simulation study in terms of their mean square error (MSE), integrated mean square error (IMSE), and mean absolute proportional error (MAPE) criteria. The FS technique outperforms the NR method in simulations, according to the empirical data.
The Estimation of Survival Function for Modified Weibull Extension Distribution Using Two-Symmetric Pentagonal Fuzzy Numbers with Simulation
Authors: Yass Shaima’a B. , Kanani Iden H. Al
Published: August 2022

In this paper, the parameters of the Modified Weibull Extension Distribution are estimated using the maximum likelihood estimator method and the Monte Carlo method in the simulation procedure to generate many different sample sizes, with many different replicates of the sample sizes. Following that finding, the Survival function’s estimate. Then fuzzify the estimation of the parameters for the same different sample sizes with the same difference in replicated sample sizes that was obtained from the Monte Carlo method in the simulation procedure by the new proposed method of expanding the Confidence Interval of estimated parameters to nine fuzzy numbers. Then, transform all the fuzzy parameters to crisp parameters using the proposed ranking functions with (proposed Linear Two- Symmetric Pentagonal Fuzzy Numbers, and proposed Non Linear Two-Symmetric Pentagonal Fuzzy Numbers). Accordingly, finding the Survival function. The outcome of Survival functions before and after fuzzy work will be compared using mean square error.
Iraqi License Plate Recognition Based on Neural Network Technique
Authors: Hussein Khalid Ali , Al-Ani Ziad Tariq A.
Published: August 2022

License Plate (LP) is the unique identification of a vehicle. License Plate Recognition (LPR) is considered as one of the promising aspects of applying computer seeing technology across intelligent transportation system. We used mathematical morphology and edge detection as a method for segmentation and extracting the vehicle license plate character, in Location of the vehicle plate. Initially, the color image was changed to a gray image, and by calculating the difference between the pixels and their neighbors in order to build the edge of the image. This makes the license panel appear clearly. The Sobel operator is applied to extract the edge of objects in the image. In order to obtain a smooth image, we apply the mathematical morphology of the images for dilation and erosion, and then we improve the efficiency of segmentation processing by using the images that are sent to the LP recognition stage. Multi-layer perceptron neural network will be used to recognize the license plate. Characters can be accurately extracted from the license plate due to the accurate extraction of the plate region.
P- Omega Limit Set in Random Dynamical Systems
Authors: Alkhrayfawee N G , Kadhim I J , Albukhuttar A N
Published: August 2022

The primary objective of this work is to investigate the idea of P-omega limit sets in a random dynamical system, where P might refer to any replete semi group in the time-space (considered a locally compact group with Harr measure). Within the context of a random dynamical system, the ideas of P-trajectory and P-invariant random sets are discussed; moreover, several fundamental features connected to these notions are looked into. The concept of a P-omega limit set of random sets in a random dynamical system is established, and several fundamental aspects are shown using mathematical proofs. In addition to this, the connection that exists between the P-trajectory and the P-omega limit set is shown.
Orthogonal Generalized Symmetric Higher Bi-Left (Resp. Right) Centralizers on Semiprime Γ- Ring
Authors: Thahab Hussein Jaber , Mehdi Salih Salah
Published: August 2022

Specialists in the field of algebra have highlighted many results related to the Γ-ring, and in my research, I will present some definitions and concepts and a major theorem parallel to the results of other researchers.
New results for certain types of contra pre-continuous functions in topological space
Authors: Öztürk Ufuk , Kharata Raghad Hussein Ali
Published: August 2022

The aim of this work, introduce some properties of another type of contra pre-continuous functions in topological space up on some generalization of closed sets, namely pre-closed and preopen sets as well as showing some theorems related about to composition and restriction for these types of functions, also submitted another types ofcontra-continuous which are bi-contra-continuous functions with several theorems about this concept have been given.
Inner Ideals of The Symplectic Simple Lie Algebra
Authors: Kareem Falah Saad , Shlaka Hasan M
Published: August 2022

Let A be an associative algebra over a field 𝔽 of any characteristic with involution and let K = skew (A) = { a ∈ A | a* = − a} be its corresponding sub-algebra under the Lie product [a, b] = ab − ba for all a, b ∈ A. In this paper, inner ideals of such Lie algebras were defined, considered, studied, and classified. Some examples and results were provided. It is proved that for every Jordan-Lie inner ideal of K, one can find an idempotent e ∈ A such that this inner ideal may be written in the form eK e*. It is also proved inner ideals of such Lie algebras are regular.
Fibrewise Fuzzy Separation Axioms
Authors: Hussain MA , Yousif YY
Published: August 2022

Within that research, we introduce fibrewise fuzzy types of the most important separation axioms in ordinary fuzz topology, namely fibrewise fuzzy (T 0 spaces, T 1 spaces, R 0 spaces, Hausdorff spaces, functionally Hausdorff spaces, regular spaces, completely regular spaces, normal spaces, and normal spaces). Too we add numerous outcomes about it.
Synthesis of nanostructure Ta2O5 coatings using plasma reactive sputtering technique for optical filter application
Authors: Abdulhamied zainab T. , Khalaf Hanaa K. , Hamoody Luma J.
Published: August 2022

Titanium bentoxide Ta2O5 deposited on glass substrates by were heated to 400 °C for 1, 2 and 6 hours. The as-deposited Ta2O5 films deposited by DC reactive sputtering show amorphous structure, the structure improved to crystalline after increasing annealing temperature. When the annealing time rises to 6 hours, Ta2O5 films with β-phase structure was obtained. The basic and optical properties of arranged films have been considered utilizing XRD and UV-Visible spectroscopy. The XRD comes about appeared that all films are polycrystalline in nature with orthorhombic structure and favored introduction along (0140) plane. The crystallite size was calculated using Scherrer formula and it is found that the 2 hrs sputtering time, 3Kv, 10Amp and 4×10-2mbar. Maximum crystallite size was (27.5nm). The absorbance and transmittance spectra have been recorded in the wavelength extend of (300-1000) nm in arrange to think about the optical properties. The optical energy gap for permitted direct electronic move was calculated using Tauc condition with regard to vitality of photon. It is found that the band gap increases with increasing annealing times and its ranges between 3.2 eV and 3.75 eV for the prepared Ta2O5 thin films.
Improved Bacterial Detection Limit via Wet KOH Etching Pathway Enhanced by Laser
Authors: Youssef Ali Ahmed , Chasb Aseel Adel , Alwan Alwan Mohamed
Published: August 2022

Laser with a fixed wavelength (405nm) at different values of intensities (50, 100, 150, 200 mW/cm2) were used to re synthesis Si nano- pillars as based SERS active substrates. The idea was to form SERS devices with high enhancement factor to sense the low residence of bacteria. The results exposed that the topographical features of the Si nano-pillars layer and so, the performance of SERS sensor could be well- controlled via the adjusting of laser intensity through the laser assisted Wet KOH process. The SERS sensing of low concentrations of shows highest bacterial enhancement factor (E.F = 30.1 × 105) and minimum detection limit (LOD = 3.30 Cfu/ml) were realized from high altitude Si nano- pillars; partly populated with three dimensions AgNPs layer, and the use of 150 mW/cm2 laser power density.
Numerical analysis of strongly coupled multicore photonic crystal fibres for multiplexer and de-multiplexer applications
Authors: Mohammed M , Ahmad A K
Published: August 2022

In this study, the coupling properties of multicore photonic crystal fibers (MCPCFs) are analyzed numerically using COMSOL Multiphysics 5.5, based on the finite element method. The dependence of the coupling properties on the structure of the MCPCFs and the wavelength are investigated to realize applications such as multiplexers-demultiplexers for wavelength division multiplexing. The effective mode indexes and transverse electric field distributions of multiple cores are evaluated for different spatial configurations of identical and non-identical cores. A slight change in the central core diameter relative to adjacent cores leads to non-identical cores that lead to wavelength-dependent coupling properties, such as the coupling lengths and strength of the coefficients. The results show that the coupling lengths become longer and the strength coefficients become smaller as the wavelength decreases for non-identical cores than the identical cores. The introduction of anisotropy to all core diameters shows that the coupling lengths become longer and the strength of the coefficients become smaller as the wavelength decreases as well, and both values become lower than the ones for non-identical cores. These results prove that coupling lengths of MCPCF couplers are significantly shorter in μm compared to conventional multicore optical fiber couplers.
Comparing the role of NaOH and NH4OH on structural and magnetic properties of spinel Ba ferrite synthesized by autocombustion method
Authors: Abdel-Mohsen L H , Lafta S H , Hashim M Sh
Published: August 2022

A comparison between using NaOH and NH4OH for synthesizing nano Ni0.1Ba0.9Fe2O4 via autocombustion method was done. During the preparation of the two samples, metal salts were dissolved in distilled water and then the two chemical bases were added separately till pH reaches 7.5. The samples were fired at 600°C for 2h. X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning electron microscope (SEM), and vibrating sample magnetometer (VSM) tests were utilized to characterize the samples. XRD test showed a spinel cubic pattern for the two samples and their lattice constants were comparable to that in literature. The calculated crystallite sizes for the two samples were so approximated. SEM images showed a greater average spherical particle size for the prepared sample by NH4OH. FTIR analysis illustrated some reaction residuals in the samples prepared by NaOH. The sample prepared by NH4OH showed higher magnetization saturation and low coercivity. Depending on particle size and squarness ratio, the sample prepared by NaOH is more super paramagnetic compared to the other.
A New Approach for Optimal Management of Solar Energy Systems
Authors: Wabdan Ahmed Ali , Betti Ahmad M. , Hassoon Zanaib k. , Al-Fayyadh Hayder Rahm Dakheel
Published: August 2022

In this article, a solar-powered photovoltaic system offers a clean energy solution to this challenge; this system is rapidly developing worldwide. Solar energy is believed to be able to meet 2% of the world’s energy requirements, and this system are designed to generate electricity for specific needs, The global development of solar systems, as well as indicators, prices and efficiency of these systems, especially in Iraq, was studied, and a model and integrated system was designed to feed one of the homes in Iraq. proposed Maximum Power Point Tracking (MPPT) control loop and using the best techniques Perturb and Observe (P&O) Algorithm extracting maximum power from PV module under different solar irradiation. Various scenarios involving environmental parameters such as temperature and radiation are presented to demonstrate the theoretical analysis, effectiveness and feasibility of the proposed energy management technique.
Effect of variation biomass on the properties of iron oxide NPs for hydrolysis of methylene blue dye
Authors: Aziz Wisam J , jumaa Aya , Abid Muslim A
Published: August 2022

Three plants extracts of Eucalyptus, Pomegranate and Oolong tea leaves have been used to synthesize iron oxide nanoparticles. The structure and particle size of the nanoparticles have been investigated by XRD spectrum. The results exhibit the polycrystalline nature of the material with a size around (17-19 nm). FESEM analysis showed that using different extracts as a reduction and capping agent might affect the shape of nanoparticles such as forming of round, polygon and irregular shapes under the same conditions. The photo catalyst activity of the prepared NPs in the degradation of MB dye has been investigated. the results showed a good efficiency reached to 91%, 88% and 80%.
Preparation and Characterization of CuO Nanostructured Thin Films by Chemical Bath Deposition
Authors: Sadiq Zainab M. , Hassan Mustafa A. , Hassoon Khaleel I.
Published: August 2022

In this work, copper oxide (CuO) thinfilms are prepared by chemical bath deposition technique (CBD). The films are investigated with respect to annealing temperature and molar concentration. According to XRD analysis, all the prepared thin films were polycrystalline with monoclinic structures and almost oriented at the planes (002) and (111). FESEM analysis revealed rod-like shapes. The observed bandgap value of copper oxide thin films ranged from 1.65 eV to 1.59 eV. CuO film exhibits high absorption in the visible spectrum. This activity is particularly intriguing in terms of the use of CuO as an absorber layer in solar cells. Moreover, the electrical conductivity and the activation energy of CuO were found to be influenced by the molar concentration and annealing temperatures. These findings show that CuO films prepared by the CBD method can be used to fabricate optoelectronic devices.
Effect of Mg doping on the optical properties of nanostructures CdO Thin film
Authors: Mishjil Khudheir A , Othman M. S. , Abdulsada Ali H , Rashid Hayfa G , Habubi Nadir F
Published: August 2022

The performance of first principles computations of nanostructured CdO and Cdo:Mg grown by spray pyrolysis method (SPM) was studied, using density functional theory (DFT)). The structural and optical behaviour with XRD and ultraviolet visible spectroscopy. DFT displayed that Cd32O32 cluster and doped magnesium have cubic with rock salt structures. The optical bandgap of nanostructure films were obtained, while theoretically calculated for Mg-doped CdO cubic structures. The optical data displayed that the magnesium doped increase optical energy gap. Moreover, Optical results displayed that reflectivity of the nanostructure films varied from (400–900 nm) range with doping. While experimental transmittance was increased about 55% for 4% and decreased to 48% for 8% concentrations.
Comprehensive Overview on Millimeter Wave Communications for 5G Networks Concentrating on Propagation Models for Different Urban Environments
Authors: Talib Mushtaq , Aripin Norazizah Binti Mohd , Othman Noor Shamsiah , Sallomi Adheed Hasan
Published: August 2022

The global shortage of bandwidth prompted wireless carriers to move towards millimeter wave frequencies (mm-wave), a frequency spectrum that is underutilized by broadband communications networks. Despite the large number of studies and researches on the issue of millimeter wave propagation in outdoor and indoor environments, specifically environments with high population density, the issue of millimeter wave propagation in those environments remains somewhat ambiguous. For the exact purpose of the design and operation of the fifth-generation networks operating within the millimeter frequency spectrum, it has become necessary to obtain information about the wave propagation within those different environments. This paper presents a description of the wave propagation parameters and channel modeling prepared by several international groups, such as line and non-line of-sight (LOS & NLOS) probabilities and different propagation models to understand the mechanism of wave propagation within the millimeter range (0.5–70 GHz). This paper deals with simulating radio wave propagation in favour of different outdoor scenarios, calculating the path loss in several models and determining which models are most appropriate and best for certain environments.
NiAl-Cl LDH in-situ grown on graphene oxide by a one-step hydrothermal method towards high performance cathode of supercapacitor
Authors: Lv Huifang , Wang Yan , Chen Zexiang , Rao Haibo
Published: August 2022

To meet the demands of modern vehicles and electronic devices, an increasing number of new materials for the cathode of high-performance supercapacitors have been studied in depth. Here, GO/NA-Cl composites were successfully fabricated by in-situ grow NiAl layered double hydroxide (NiAl LDH) nanosheets on graphene oxide (GO) flakes through one-step hydrothermal procedure for the cathode of supercapacitor. The image of scanning electron microscopy (SEM) exhibited that the NiAl-Cl LDH nanosheets were evenly and vertically arranged on the GO flakes and interlaced to form a network structure, presenting a considerable surface area, which afford abundant active sites in contact with the electrolyte and alleviate the expansion of GO/NA-Cl during the process of electrochemical reaction to improve its stability. The results of electrochemical test show that the GO/NA-Cl is a typical pseudocapacitive material, which provides a prominent specific capacity of 1573 F/g at 1 A/g, and superior rate property (the rate of capacity retention is 62% even at 20 A/g). Furthermore, the GO/NA-Cl electrode shows a superior cycling life after 1000 cycles at 1 A/g with about 80% capacitance retention.
Analysis System of the Curing Degree of CFRP Products Based on MATLAB
Authors: Yu Bo , Zhu Nan , Chi Bo , Chen Yuning , Wang Wei , Liu Jiaqiu
Published: August 2022

Carbon fiber reinforced composites (CFRP) have great application prospects in the aerospace field by virtue of their excellent mechanical properties. In the molding process of CFRP products, the curing degree is an important characterization parameter of CFRP. By taking the heating rate, holding time, holding temperature, and cooling rate of the CFRP curing process curve as input data based on MATLAB and relying on an artificial neuron network algorithm, the accurate simulation values of the curing degree of CFRP are obtained, thereby achieving high-accuracy prediction of the curing degree of CFRP. This system can predict the curing degree of CFRP for a given matrix material, reinforcing material, and molding process, with good reliability and high precision. Therefore, this system has a good application prospect in predicting the curing degree of CFRP, and it will have a broad application prospect even in the aerospace field.
Study on fretting wear properties of medical Mg-2.0Zn-1.6Ca alloy
Authors: Guo Xuan , Song Yuwei , Sang Shunheng , Qiao Yang
Published: August 2022

Due to its good biocompatibility and biomechanics, magnesium alloy has made great progress in the application of absorbable and implantable biomedical materials in recent years. At the same time, the disadvantages of magnesium alloy materials are more obvious. Because of its poor wear resistance, magnesium alloy is easy to fret with human bones after being implanted as a bone plate, resulting in wear pits and failure. In this paper, magnesium alloy was prepared, calcium and zinc elements were added into pure magnesium according to a certain proportion, and then the magnesium alloy with excellent performance was formed by solid solution treatment and extrusion strengthening. After that, fretting friction type, friction coefficient and wear pits were studied by fretting wear test. The results show that with the decrease of extrusion temperature, the surface hardness increases and the friction coefficient decreases, which is very beneficial to improve the wear resistance of the workpiece. The purpose of this paper is to improve the fretting wear performance of magnesium alloys, and to provide theoretical and practical guidance for the preparation, processing and application of high-performance medical magnesium alloys.
A comprehensive review on applications of 3D printing in natural fibers polymer composites for biomedical applications
Authors: Chohan Jasgurpreet Singh , Kumar Raman , Singh Sandeep , Sharma Shubham , Ilyas R A
Published: August 2022

Over the past few decades, three-dimensional (3D) printing technologies have surpassed the conventional manufacturing techniques due to their wide applications and advantages. The applications of 3D printing in biomedical field is ever increasing due to improvement in accuracy and surface quality of products. The development of biomedical implants through patient specific data and rapid tooling techniques has revolutionized the research activities. Now-a-days, the metal printers have capability to directly create metal implants using biocompatible metallic alloys. This paper focuses on the potential applications of 3D printing in biomedical fields with specific emphasis on tissue engineering and bio-printing of organs using bio-inks. This paper also reviews various biocompatible and biodegradable materials used in recent in-vivo and in-vitro studies. It has been deduced from the study that use of natural fibers in polymers resulted in improved mechanical strength of products. Also, the implementation of additive manufacturing technologies for production of composites would lead to production of customized product.
A study on the hybrid polystyrene composite filled with elephant-grass-biochar and doped-aluminium-content
Authors: Adeniyi Adewale George , Abdulkareem Sulyman A , Ighalo Joshua O , Abdulkareem Maryam T , Iwuozor Kingsley O , Emenike Ebuka Chizitere
Published: August 2022

This study aimed to investigate the crystallographic, functional group and microstructural analysis of elephant grass biochar reinforced hybrid polystyrene composite doped with aluminium. The composites were prepared by the mixing and hand-layup technique. Composites were characterised by x-ray diffractometry, Fourier transform infra-red spectroscopy and scanning electron microscope. It was observed that crystallographic properties of the composite were improved by aluminium doping. Crystallite size and d-spacing were found to decrease from 6.3542 to 5.2453 nm and 3.183 to 2.362 Å respectively due to 8% aluminium doping. Functional group analysis revealed that doping affected interactions between biochar and polystyrene resin. Microstructural analysis revealed that dispersion was optimal at 2% doping and interfacial adhesion was optimal at 8% doping.
Attention feature fusion network for small traffic sign detection
Authors: Wu Miaozhi , Yang Jingmin , Zhang Wenjie , Zheng Yifeng , Liao Jianxin
Published: August 2022

Object detection has made great progress with the rise of convolutional neural networks in recent years. Traffic sign detection is a research hotspot for object detection tasks. The existing detection models have the problems of inaccurate positioning and low classification accuracy when detecting small traffic signs. To address these issues, in this paper, we propose a small traffic sign detection method based on YOLOv4. Specifically, we design an attention-based feature fusion module including attention spatial pyramid pooling (ASPP) and attention path aggregation networks (APAN). ASPP highlights useful small object information and suppresses invalid interference information in the background. APAN reduces information loss during feature fusion. A large number of experimental results on public datasets show that the method in this paper improves the detection performance of the model. In terms of small traffic sign detection, the method improves YOLOv4 by 12 mAP, and meets the real-time requirements of automatic driving detection (more than 50 FPS).
Introducing ‘Environmental Research: Ecology’—a new journal devoted to addressing global challenges at the interface of environmental and ecological science, biodiversity and conservation
Authors: Goetz Scott J
Published: August 2022

Environmental Research: Ecology is a new open-access journal focused on addressing important global challenges at the interface of environmental science, large scale ecology, biodiversity and conservation in a way that bridges scientific progress and assessment with efforts relating to impacts of global change, vulnerability, resilience, mitigation and adaptation in the broadest sense. While there are many journals addressing various aspects of ecology, those focused on macroscale changes across ecosystems, biomes and at continental to global scale geographies are far fewer. Because ecosystems across the globe are undergoing enormous changes brought about by human-induced transformations and associated feedbacks to and alteration of the climate system, it is more important than ever that a forum exists for addressing these issues in a fully Open Access publishing venue. Environmental Research: Ecology provides that platform and is supported by an Editorial Board of high profile ecologists covering a broad range of disciplines and geographies.