bluuebunny/crossref_metadata_2025 huggingface dataset:
Machine learning assisted search for Fe–Co–C ternary compounds with high magnetic anisotropy
Authors: Xia Weiyi , Sakurai Masahiro , Liao Timothy , Wang Renhai , Zhang Chao , Sun Huaijun , Ho Kai-Ming , Chelikowsky James R. , Wang Cai-Zhuang
Published: October 2024

We employ a machine learning (ML)-guided framework to explore rare earth free magnetic materials, specifically focusing on Fe–Co–C ternary compounds for potential use in permanent magnets. Utilizing a specifically trained crystal graph convolutional neural network model, we efficiently screen a vast space of nearly a million substitutional structures to select 620 promising structures for further investigation by first-principles calculation. We predict five low-energy metastable Fe–Co–C compounds with formation energy less than 150 meV/atom above the convex hull. These compounds exhibit high magnetization (Js > 1.0 T) and significant magnetic anisotropy (K1 > 1.0 MJ/m3), making them promising candidates for permanent magnet applications. The phonon calculations indicate these compounds are dynamically stable. Our ML-guided framework demonstrates the utility of rapidly identifying novel materials with tailored magnetic properties.
Photonic Ising machines for combinatorial optimization problems
Authors: Gao Yuan , Chen Guanyu , Qi Luo , Fu Wujie , Yuan Zifeng , Danner Aaron J.
Published: October 2024

The demand for efficient solvers of complicated combinatorial optimization problems, especially those classified as NP-complete or NP-hard, has recently led to increased exploration of novel computing architectures. One prominent collective state computing paradigm embodied in the so-called Ising machines has recently attracted considerable research attention due to its ability to optimize complex problems with large numbers of interacting variables. Ising model-inspired solvers, thus named due to mathematical similarities to the well-known model from solid-state physics, represent a promising alternative to traditional von Neumann computer architectures due to their high degree of inherent parallelism. While there are many possible physical realizations of Ising solvers, just as there are many possible implementations of any binary computer, photonic Ising machines (PIMs) use primarily optical components for computation, taking advantage of features like lower power consumption, fast calculation speeds, the leveraging of physical optics to perform the calculations themselves, possessing decent scalability and noise tolerance. Photonic computing in the form of PIMs may offer certain computational advantages that are not easily achieved with non-photonic approaches and is nonetheless an altogether fascinating application of photonics to computing. In this review, we provide an overview of Ising machines generally, introducing why they are useful, what types of problems they can tackle, and how different Ising solvers can be compared and benchmarked. We delineate their various operational mechanisms, advantages, and limitations vis-à-vis non-photonic Ising machines. We describe their scalability, interconnectivity, performance, and physical dimensions. As research in PIMs continues to progress, there is a potential that photonic computing could well emerge as a way to handle large and challenging optimization problems across diverse domains. This review serves as a comprehensive resource for researchers and practitioners interested in understanding capabilities and potential of PIMs in addressing such complex optimization problems.
Elemental diffusion coefficient prediction in conventional alloys using machine learning
Authors: Kulathuvayal Arjun S. , Rao Yi , Su Yanqing
Published: October 2024

This paper presents the Machine Learned Diffusion Coefficient Estimator, a comprehensive machine learning framework designed to predict diffusion coefficients in impure metallic (IM) and multi-component alloy (MCA) media. The framework incorporates five machine learning models, each tailored to specific diffusion modes: (1) impurity and (2) self-diffusion in IM media, and (3) self, (4) impurity, and (5) chemical diffusion in MCA media. These models use statistical aggregations of atomic descriptors for both the diffusing elements and the diffusion media, along with the temperature of the diffusion process, as features. Models are trained using the random forest and deep neural network algorithms, with performance evaluated through the coefficient of determination (R2), mean squared error (MSE), and uncertainty estimates. The models within this framework achieve an impressive R2 score above 0.90 with MSE less than 10−16 m2/s, demonstrating high predictive accuracy and reliability for diffusion coefficient.
Analysis of activation energy, chemical reaction, and variable density on magnetically driven heat transportation: Applications in nanofluid lubrication and machining
Authors: Ullah Zia , Alam Md. Mahbub , Khan Aamir Abbas , Alkarni Shalan , Merga Feyisa Edosa , Khan Qaisar
Published: October 2024

The importance of this investigation is to examine the heat and mass transportation of magneto nanofluid movement along a heated sheet with exponential temperature-dependent density, entropy optimization, thermal buoyancy, activation energy, and chemical reaction aspects. The influence of these factors in cutting tools by means of machining and nanofluid lubrication is a significant process in cutting zone, chip cleaning, lubricating, and cooling productivity in milling. The corresponding energy activation and chemical process are essential to understand the thermal behavior of nanofluid. The appropriate transformations are used to solve nonlinear partial differential equations within the framework of ordinary differential equations using stream functions and similarity variables. The Keller box method is employed to efficiently solve these equations computationally under the Newton–Raphson approach. Through tables and figures, the fluid velocity, temperature distribution, and concentration consequences are sketched using various controlling parameters. It is seen that the fluid temperature function increases with noticeable amplitude as the Eckert factor, variable density, chemical-reaction, and activation energy increase. It is found that the noticeable enhancement in heat and mass transportation is deduced for maximum Brownian motion and thermophoresis. This work is important in various applications such as cutting fluids, drilling, brake oil, engine oil, minimum quantity lubrication, enhanced oil recovery, and controlled friction between the tool-chip and tool-work during machining operations.
Improving the efficiency of aerial surveys for monitoring North American beaver population dynamics
Authors: Kenyon Madeline , Dennison Catherine C. , Popescu Viorel D.
Published: October 2024

Context The North American beaver (Castor canadensis) was extirpated from much of its range in the US in the 1800s due to fur trapping and change in land use. However, the species has recolonised much of its former range, including the US state of Ohio. Since 2013, the Ohio Division of Wildlife (ODOW) has monitored trends in beaver colony density via aerial surveys of 40 km × 40 km plots classified as low, medium, or high suitability based on the amount of wetland. Nonetheless, the current classification system may miss important correlates of beaver colony density. Aims Our study aimed to (1) identify predictors of beaver colony density (number of colonies inferred from aerial counts of lodges) across Ohio, and (2) develop a model-based classification system to improve the efficacy of monitoring efforts. Methods To predict beaver colony density in Ohio we used an aerial survey dataset of 54 plots (40 km × 40 km) collected by ODOW annually between 2013 and 2020, along with a suite of environmental, anthropogenic, and climate variables in a mixed effects modelling framework. Key results Beaver colony density was positively associated with wetland and reclaimed surface mine areas and inversely associated with the proportion of agricultural lands. There was a negative interaction between wetland and surface mines; in general, beaver colony density increased with wetland and surface mine area. However, in plots with wetland area >1000 ha, beaver colony density was weakly negatively associated with surface mine area. Using median and interquartile ranges of model-averaged predicted beaver colony density, we developed a new classification of low, moderate and high suitability for both the survey plots and the entire state of Ohio. We found that eastern Ohio had high suitability, while the central and western parts of the state had lower suitability for C. canadensis. Conclusions Our approach to identifying predictors for beaver colony density at broad spatial scales highlights the importance of reclaimed surface mines and wetlands for beaver populations, while the model-based habitat classification provides ODOW additional information for monitoring and beaver management decisions. Implications Improved C. canadensis monitoring at the landscape scale using habitat classifications that consider local conditions can both improve annual survey cost-effectiveness and facilitate the sustainable management of this recovering species.
Self-views converge during enjoyable conversations
Authors: Welker Christopher , Wheatley Thalia , Cason Grace , Gorman Catherine , Meyer Meghan
Published: October 2024

Based on current research, it is evident that the way people see themselves is shaped by their conversation partners. Historically, this literature focuses on how one individual’s expectations can shape another person’s self-views. Given the reciprocal nature of conversation, we wondered whether conversation partners’ self-views may mutually evolve. Using four-person round-robin conversation networks, we found that participants tended to have more similar self-views post-conversation than pre-conversation, an effect we term “inter-self alignment.” Further, the more two partners’ self-views aligned, the more they enjoyed their conversation and were inclined to interact again. This effect depended on both conversation partners becoming aligned. These findings suggest that the way we see ourselves is coauthored in the act of dialogue and that as shared self-views develop, the desire to continue the conversation increases.
The Research on Self-Excited Oscillating Jet Cleaning Technology
Authors: Qunwu Pei , Guifu Tang , Yan LYU , Songting Wang , Yan Wang , Lin Xu
Published: October 2024

Self-oscillating nozzles have gained wide popularity due to their ability to generate powerful impact forces, long-range projection, and concentrated, stable jets in applications such as water-jet drilling and rust removal. However, the nozzle’s efficient operation relies heavily on specific structural designs and operational parameters, which necessitates further indepth research. By studying the characteristics of self-excited oscillating pulse cavitation jet within the nozzle cavity structure. Analyzing the evolution characteristics of internal flow field. Solving optimization problems in a targeted manner. The purpose of this study is to reveal the resonance principle behind the self-excited oscillation of nozzle. It also explores the regularities of the effects that the cavity diameter has on jet performance, ultimately seeking to find the optimal configuration of nozzle structure and operating conditions.
Observation of wear around surface crack of PEEK thrust bearing under rolling contact fatigue in water
Authors: Machino Sasuga , Shinkai Shogo , Matsueda Takahiro , Mizobe Koshiro , Kida Katsuyuki
Published: October 2024

Rolling bearings are important mechanical elements for machines. Poly-ether-ether-ketone (PEEK) polymer is a suitable material for bearings in water and corrosive conditions because of its excellent water and chemical resistance. Some study had been examining rolling contact fatigue (RCF) tests in water; however, the competition between cracks propagation and wear on the surface of PEEK bearing in water was not clear. In the present study, in order to evaluate the crack propagation and wear process, RCF test with PEEK thrust bearings at 3750 [N] in water was carried out. The lengths of the surface cracks and the profiles of the grooves were observed at different number of cycles. In addition, so as to identify the cracks which cause the flaking, start-stop test was carried out. We found the surface crack, which was initially observed at 4.62×105 cycles, were gradually worn down and completely disappeared at 6.32×105 cycles. We concluded that rolling contact fatigue caused some surface cracks of PEEK to wear down in water condition.
Damage effects of KDP crystals induced by nanosecond laser
Authors: Gao Yang , Zhang Liqing , Chen Yuanpan , Qiu Rong
Published: October 2024

The surface morphology, compositions, microstructures, and chemical bond vibrations of potassium dihydrogen phosphate (KDP) crystals induced by nanosecond laser with different wavelengths, at different energy density are studied by scanning electron microscopy (SEM) and infrared spectroscopy (IR) techniques. SEM results showed that with the increase of laser energy density, the damage region on KDP surfaces presented three parts evidently. And the damage area increases nonlinearly with the laser energy density, accompanied by an increase in O element contents and a decrease in P and K element contents. Meanwhile, at the same energy density, the damage area induced by the 355 nm nanosecond laser is much larger than that by the 1064 nm nanosecond laser. Infrared spectrum results revealed that the laser irradiation leads to a break in hydrogen bonds and a dehydration of KDP crystals, in conjunction with a generation of P=O and P-H bonds. Moreover, with the increase of the laser energy density, the KDP crystal is damaged firstly, and then is annealed and repaired, finally is destroyed again. In addition, after irradiation at 10 J/cm2, all vibration modes of KDP crystals weaken or even disappear, and the sever damage occurs.
Study on the Synthesis of BTA@MSNs Nanocarriers
Authors: Tang Xiuming , Wang Baichen , Gao Yu , Li Wei , Lu Shaowei
Published: October 2024

Mesoporous silica, characterized by its adjustable pore size, uniform distribution, stable structure, and non-toxicity, is widely used as an encapsulating material for corrosion inhibitors. This study initially established that, compared to the high-temperature calcination method, the removal of surfactants via the solvent extraction method yields mesoporous silica with uniform size and better dispersibility. Results from N2 adsorption-desorption tests indicated that the mesoporous silica prepared by the solvent extraction method had an average pore diameter of 2.41 nm, a volume of 0.42 cc/g, and a specific surface area of 69.73 m2/g. SEM and TEM analyses showed that the BTA@MSNs nanoparticles synthesized via a one-step method were approximately 100 nm in size, whereas those prepared by the vacuum loading method were about 50 nm, both exhibiting ordered mesoporous structures. UV-vis spectrophotometry results revealed that the loading capacity of BTA in the nanoparticles produced by the one-step synthesis method was significantly lower than that in the BTA@MSNs nanoparticles prepared via the vacuum impregnation method.
Study on the influence of heat treatment process on the microstructure and hardness of carburized layer of 20CrMoH steel
Authors: Duan Luzhao , Gao Zhixin , Sun Zhiyan , Sun Caifeng , Sun Jiangbo , Zhang Peizi , Ren Shuai
Published: October 2024

In this paper, the effects of different carburizing quenching processes and tempering processes on the depth of the hardened layer and microstructure of 20CrMoH were studied by means of hardness analysis and SEM microstructure analysis. The results show that: when the quenching temperatures in the range of 820-880 °C, it has little effect on the depth of the hardened layer. And the hardness value at the same depth is at a considerable level, which is not affected by the quenching temperature. When the tempering temperature range is 150-280 °C, the tempering temperature has a great influence on the depth of hardened layer. And with the gradual increase of tempering temperature, the depth of hardened layer decreases gradually. Also the hardness value at the same depth from the edge shows a monotonous decreasing trend with the gradual increase of tempering temperature.
Investigation of new steel with increased strength for low temperature applications
Authors: Poletskov Pavel , Koptseva Natalia , Efimova Yulia , Kuznetsova Alla , Gulin Aleksandr , Alekseev Daniil , Emaleeva Dinara
Published: October 2024

The work established the patterns of a structural and phase transformations which occurs in the new steel of the 0,21C-1,0Mn-1,8Ni-0,3Cu-0,3Mo-0,03Ti-0,004B (%, mass) alloying system at different cooling rate. A thermokinetic diagram has been constructed. Laboratory samples of rolled products were manufactured and the mode of hardening of rolled sheets from a temperature of 860 ° C in water was tested to develop the industrial production of new steel using specialized equipment of the laboratory complex of LLC “EC Termodeform-MSTU”. The results of mechanical tests of rolled sheet samples after heat treatment showed that the steel under study in a hardened state has high strength characteristics in complex with increased impact strength at a test temperature of minus 70 °C: tensile strength σUTS = 1500 MPa, yield strength σ0.2 = 1150 MPa, relative elongation A5 = 12.5 %, hardness 429 HBW, impact strength KCV−70 = 50.3 J/cm2. This confirms its high quality and the possibility of using it for the production of heavily loaded mechanical engineering structures operated at low temperatures in the conditions of the Far North and the Arctic zone of the Russian Federation.
Curing and Failure Monitoring of Composite Material Single-Lap Joint Based on CNT/PSF Sensor
Authors: Wang Yuxuan , Cui Xiaoyu , Lu Shaowei , Ding Kaifei , Wang Ying , Zhang Lu
Published: October 2024

Composite bonded structures are widely used in the field of aerospace. The safety of composite structures can be ensured by the health monitoring and early warning of their whole life. In this paper, a composite CNT/PSF film sensor based on asymmetric porous PSF film was designed and prepared. Through integrated molding with epoxy film, in-situ monitoring of gel point (142.1°C) and curing time (36min) of epoxy film is realized. After optimization of curing process, tensile strength of epoxy film casting body is increased by 86.3%. The single lap shear strength of the composite is increased by 45.7%. The CNT/PSF film sensor with composite material has high response sensitivity (GF≈1.4) and linearity (0.998) to cyclic strain (0-3000με). In the shear experiment of composite single lap joint, the adhesive layer presents a typical cohesive failure mode of first compression, then tensile and finally failure. The resistance changes of CNT/PSF film sensor first decreases from 0 to -1‰, and then rises to 2.7‰. Finally, the fracture response is good, and the in-situ failure behavior monitoring of the joint can be fully realized.
Research on laser polishing process of zirconia ceramic surface
Authors: He J , Zhao Z Y , Zhou Z W
Published: October 2024

In order to investigate the polishing results of carbon dioxide pulsed laser on the surface of zirconia ceramics, this paper analyzes the significance of the influence of each process parameter on the surface roughness in the laser polishing process based on the experimental design of the response surface method and taking the surface roughness as the optimization objective. And the best combination of process parameters for the laser polishing process is predicted by establishing a surface roughness prediction model. The results of the experiments show that among the laser polishing process parameters, the scanning speed and laser power have an extremely significant effect on surface roughness, while the pulse frequency has a more significant effect on surface roughness. The model predicts the optimum combination of working parameters as: laser power P = 75W, pulse frequency f = 4 kHz, scanning speed v = 380 mm/s. Under the optimum combination of process parameters, surface roughness Ra = 0.595μm of the material, which is 76% lower than that of the original surface roughness of 2.479μm after laser polishing.
Generalized poisson regression for over-dispersed longitudinal count data
Authors: Liu Huaxian , Yu Jing , Su Liyun
Published: October 2024

Longitudinal count data is a common type of discrete data in fields like medicine and social sciences. The Poisson regression model is an important method for analysing count data, and the standard Poisson regression model requires that the mean and variance of discrete count data are equal. However, longitudinal count data are often over-dispersed in practice, i.e., the variance of the data is greater than the mean. Besides, the degree of dispersion between the mean and variance of longitudinal count data varies over time. A generalized Poisson regression model based on joint modeling of the mean and dispersion parameters of over-dispersed longitudinal count data is proposed, which simultaneously describes the trajectories of longitudinal mean and dispersion parameters over time and explains how they are dependent on other covariates. The simulation results and real data analysis illustrate the accuracy and effectiveness of the proposed method.
Comparative study on the influence of chemical reaction mechanisms on turbulent jet flame
Authors: Wang Yunfan , Jin Jie , Lai Genhong , Wang Fang
Published: October 2024

This paper focus on the influence of chemical reaction mechanisms on the simulation of turbulent jet flame of 11 different chemical reaction mechanisms. These mechanisms are mainly selected from GRI series and their reduced mechanisms, and their reaction kinetics were analyzed. This paper uses LES-TPDF method to simulate Sandia Flame D turbulent jet flame and then analyze the difference of time-averaged temperature, heat release rate and species concentration results in different mechanisms. The results show that the kinetic performance of different chemical mechanisms is very different. The ignition delay time of JL4, SMOOKE and z42 mechanisms are either overestimated or underestimated due to the omission of multi-carbon species and other important species. The differences of the LES results in different mechanisms increase along the axis. The differences near the fuel inlet are mainly due to the difference of kinetic performance, while the difference away from the fuel inlet is more due to the different species and elementary reactions involved in different chemical reaction mechanisms. For all chemical mechanisms, there is a tendency that the more species used in the chemical reaction, the more concentrated the region of high heat release rate, the shorter the flame length, and the higher the maximum temperature throughout the field.
Simulating the dynamics of a 2D multicomponent vesicle in time-dependent elongation flow
Authors: Liu Kai
Published: October 2024

This paper is concerned with the nonlinear dynamics of multicomponent vesicles in a time-dependent elongational flow. Using a nonstiff, pseudospectral boundary integral method, we investigate the dynamical patterns induced by negative surface tension and inhomogeneous bending for a two phases system. For both quasi-circular and elongated vesicles, high frequency wrinkles can be excited in flow with strong elongational rate after the flow’s direction is reversed. Unevenly distributed phase diagram leads to asymmetric wrinkling pattern, and the characteristic wavelength for each phase is well reserved. In weak flow, bucking behaviours are observed for elongated vesicles and the membrane bends inward at regions with lower bending moduli.
Measurement principle and electric field analysis of tissue equivalent proportional counter
Authors: Yuan Wang Xi , Fan Su Yang , Pan Guo Yi , Yong Wei Zhi
Published: October 2024

TEPC is the preferred device for measuring microdoses due to its excellent organizational equivalence and high energy response. The most important factor affecting its energy response is the electric field distribution in the avalanche region. This paper uses finite element analysis to examine the electric field distribution of a spherical structure with a sensitive area diameter of 2 cm and a cylindrical structure with a sensitive area of 2 cm × 2 cm. While the spherical structure exhibits better isotropy, it has significant distortions in the electric field at the anode wire end, making compensation optimization complex and hindering miniaturization. Cylindrical structures can compensate for the electric field by adding insulators at the anode wire end. When the insulator diameter is 3mm, the optimal protrusion length into the chamber is also 3mm. This lays the foundation for the miniaturization of TEPCs in subsequent research.
Unconventional photon blockade in a nonlinear system embedded with an atom
Authors: Wang Yuxuan , Yang Hui , Yao Zhihai
Published: October 2024

The unconventional photon blockade effect due to quantum interference in a second-order nonlinear system embedded with a two-level atom is studied. By performing analytical calculations, the approximate results are obtained. By solving the master equation, the numerical calculation results are also obtained. Results show that the analytical results are consistent with the numerical results, which proves that unconventional photon blockade can be realized in this system. Furthermore, the effects of the system parameters on the unconventional photon blockade are also discussed. All the results may provide useful references for experimental investigations and practical applications of single-photon devices.
A fast identification method of surface heat flux based on numerical pre-calibration and regularization
Authors: Wu Long , Wang Qi , Wang Feng , Liu Jianxia , He Yuanyuan
Published: October 2024

Identification of surface heat flux is a technique of retrieving heat flux from the measured temperature in an object. The inverse heat conduction problem abbreviated as IHCP is ill-posed, and its highly ill-conditioned characteristics lead to unstable numerical calculation. In this paper, we build an identification equation with the theory of linear superposition. The matrix of pulse sensitivity coefficient is established by formula for one-dimensional model. And a finite element pre-calibration approach is proposed to obtain the matrix of pulse sensitivity coefficient for complex three-dimensional structures. Regularization methods including Tikhonov method and algebraic reconstruction technique are utilized to reduce the sensitivity of measurement error. Numerical simulation shows that this method is efficient and accurate.
Research on anti-single event ability and reinforcement method of SiC MOSFET
Authors: Qin Linsheng , Wang Bo , Huang Yuhan , Ma Lindong , Liu Yuan , Ju Anan , Wang Kunshu
Published: October 2024

High-voltage silicon carbide (SiC) metal-oxide field-effect transistor (MOSFET) is limited by its ability to resist single event effect (SEE), so it is necessary to study its ability to resist SEE and form an effective reinforcement method. In this paper, it will be studied that how the influence of device structure on the anti-single event ability of SiC MOSFET from the irradiation experiment, and the safe working area of single event leakage degradation of the device is examined. It is found that the width of junction field effect transistor (JFET) and P- type ohmic contact interval both affect the SEE of the device. The SEE mechanism of the device is analyzed based on the experimental results. And the failure caused by local electrothermal stress concentration is confirmed. In view of this mechanism, the reinforced structure is designed with SiO2 barrier layer added in the single event sensitive area, the electrical stress is effectively alleviated, and the peak drain current is reduced by about 18%.
Uncertainty analysis method of high-speed wind tunnel standard model test results based on GUM and MCM
Authors: Du Yufeng , Wang Lulu , Zhu Jilong , Wang Weizhong , Xiong Neng , Guo Danping
Published: October 2024

The standard model is a standard calibration model that has a well-known geometric shape and can represent the aerodynamic layout characteristics of a certain type of aircraft. It has many functions, including evaluating the accuracy of wind tunnel test data, verifying the integrity of the wind tunnel flow field and measurement system, and developing and verifying wind tunnel test technology. Conducting wind tunnel tests using standard models is a key step in realizing the functions of standard models. However, all existing literature on standard model tests has not effectively evaluated the uncertainty of the test results, which makes it impossible to evaluate the reliability of the test results. Based on the GUM and MCM uncertainty analysis methods, this paper establishes a method for quantitatively evaluating the uncertainty of the test results of high-speed wind tunnel standard model tests through rigorous mathematical derivation, providing technical support for precisely quantifying the uncertainty of standard model test results.
Design and FEA verification of high dimensional and multi-field smart soft material
Authors: Pang Xin , Liu Anchen , Yang Guyeli , Zhu Jun , Huang Ran , Ma Xin
Published: October 2024

We designed a sophisticated smart soft tissue material that simulates the properties of biological soft tissue and detects three-dimensional force. Inspired by electronic skin, this material uses capacitive pressure sensors and multi-layer sensor packaging. Finite element analysis and multi-field simulation were employed for structural design and verification. The study evaluated the theory and practicality of a flexible capacitive 3D force sensor for detecting pressure and shear force. Mechanical and electrical properties were confirmed through force and electric field simulations. The 3D force detection method proved feasible, achieving sensitivity levels of 10−4
kPa
−1 in the X and Y directions, and 10−3
kPa
−1 in the Z direction, demonstrating the effectiveness of our design.
Numerical Studies of Solid Rocket Propellant PMMA-PBAN-ALF3-Nitrocellulose-Difluoramine
Authors: Srivastava Sachin , Hamshitha G. , Jagannath V. , Kothenty Gaurav , Haldar Subham , Rajendran Ajith Raj , Thapliyal Subham
Published: October 2024

The aim of the new investigation is the evaluation of solid rocket Propellant. In which performing numerical analysis of solid rocket propellant and calculating the constraints involved as derived from thrust i.e. velocity involved in the solid rocket propulsion motor usage. This paper aims to show the viability of solid rocket propellant for modern and future applications. Solid rocket motors are simple in design and fabricating. The need for a propellant that produces the same specific impulse as another chemical rocket engine. So it is needed to have a solid rocket motor with an enhanced combustion characteristic at a reasonable O/F ratio. For a healthy ecology, an economically reliable, highly effective, and environmentally concerned propellant is constantly suitable. As a superior alternative among the already used propellants in the sector, the paper suggested fuel PolyMethyl MethAcrylate (PMMA), PolyButadiene AcryloNitrile (PBAN) CoPolymer, and Aluminum hydride (AlH3), and oxidizers such as Nitrocellulose and Difluoramine. The desired O/F ratio for the technical criteria was found to result in a high combustion characteristic. With the features discovered through numerical and analytical research, we have suggested a design for the SRM that includes post-combustion, which enhances the reaction and creates the innovative elements of the existing SRM.
Dynamic characteristics of a flexible rotor supported on surface textured journal bearings
Authors: Srivastava Ashish , Rahmani Faisal
Published: October 2024

This paper presents the dynamic characteristics of a flexible rotor supported on surface textured journal bearings. Oil lubricated journal bearings exhibit the self-exited whirling of rotor, leading to instability. Understanding the threshold speed of instability is crucial in mitigating excessive vibration in rotating machinery. In this work, a simple model of a flexible rotor with central disc is studied. Modal analysis is carried out to obtain the whirl frequencies of the system, mode shapes, and stability limit speed. The addition of surface textures to the journal bearing stands out as a significant modification aimed at improving performance. Fully textured and partially textured bearing surfaces are considered in the investigation and compared with the performance of smooth journal bearings. Notably, fully textured bearings enhance stability limits. This study offers insights essential for optimizing machinery performance and minimizing operational risks.
Influence of gamma-irradiation on the physical properties of epoxy/polyaniline composites and application as gamma dosimeter
Authors: Hamad Hadeel Tariq , Mohammed Hadi Hassan , Ali Hayder Mohammed , Alwan Tariq J
Published: October 2024

The epoxy/pani samples doped with a specified weight ratio of polyaniline pani ware prepare by casting method. Using different doses of gamma rays (0, 2, and 4 kGy) were used to irradiated the prepared samples. Irradiated and non-irradiated samples were imaged using a FE-scanning electron microscope and were found to have regular morphology, and irradiation had obvious effect on this morphology at 4 kGy. When studying the crystal structure of the samples, it was found the samples have a polycrystalline structure, and this structure tends to improve after irradiation, this was verified using X-ray diffraction. Likewise, D.C electrical conductivity increased with increasing gamma radiation doses. Also study the effect of irradiation with gamma rays on optical properties and demonstrate the clear effect of these rays on optical properties. It was also found that the optical energy gap with (indirect allowed transition) was decreases after the irradiation process. Together, these results indicate the possibility of using these samples in the manufacture of gamma dosimeters.
An investigation into the implications of partial substitution of selenium with lead on the thermal properties for S60Se40-XPbX Chalcogenide Compound
Authors: Ghazi Mohamed Muthana , Jasim Kareem Ali
Published: October 2024

This study includes the manufacture of four ternary alloys represented S60Se40-XPbX with weight ratios x = 0, 10, 20, and 30 by the melting point method. The components of each alloy were mixed separately, then placed in quartz ampoules and vacuumed out with a vacuum of roger that 10−4 Torr. The ampule was heated in two stages to avoid sudden dissipation and precipitation of selenium on the inner mass of the quartz tube. The ampoule was gradually heated and kept at 450°C for approximately 4 hours followed by 950°C for 10 hours.at a rate of 10 degrees Celsius, the temperature of the electric furnace was increased, and then the ampoule was subjected to rapid cooling with cold water to reach a state of solidity glass-like. The research aims to investigate the effect of adding lead to selenium on the properties of thermal conductivity and heat flux density. It has been noted that the partial replacement of selenium with lead affected these properties significantly.
Preliminary results in the manufacture of anodic electrodes for potential use in microbial fuel cells.
Authors: Flores Segundo Rojas , Benites Santiago M. , Cruz-Noriega Magaly De La , Nazario-Naveda Renny
Published: October 2024

Microbial fuel cells are a bioelectrochemical technology that uses different types of waste as fuel sources to generate sustainable and environmentally friendly electricity. Various MFCs have been developed, with the electrode used being a crucial problem due to its high manufacturing cost. This research shows that electrodes can be manufactured quickly and economically using activated carbon (100 g), sugar (80 g), ethanol (250 ml), and pine resin (200 g). For its demonstration, grape waste was used in a single-chamber MFC for 35 days. The manufactured electrode generated a Rint. of 18.471 ± 2.475 Ω, whose current density was 8.348 ±0.768 mW/cm2 at a current density of 5.166 A/cm2. The electrical potential shown was 0.889 ± 0.017 V and 4.571 ± 0.061 mA, with an ORPmax of 81.495 ± 1.874 mV, operating at a pH of 7.26 ±0.19. The micrographs made by scanning electron microscopy showed porous surfaces with carbonaceous substances in the final monitoring stage. These preliminary results showed excellent performance of the electrodes, showing their potential for use in MFCs in an economical way.
Investigating optical, structural and morphological properties of CuxZn1-xS thin films
Authors: Soud Ali Jwad , Al-Maiyaly Bushra K.H.
Published: October 2024

CuxZn1-xS (CZS) Nano crystallized thin films with (x=0.25,0.5,0.75) were grown from alloy by thermal evaporation technique on glasses substrates at room temperature in a vacuum ∼ 2 × 10 −5 mbar with 450±20 nm thickness. The Cu content concentration effects on structure, morphology besides optically property of these films were investigated. X-ray diffraction (XRD) technique and Atomic force microscopy (AFM) were used to investigation the structural and morphological properties of CuxZn1-xS films. XRD analysis offered that these films had poly crystalline hexagonal structure with preferred orientation along (201) plane and mixed of of CuS-ZnS structure. The crystallites size changing with Cu concentration were found as (4.12, 5.5, 8.4) nm respectively. Using AFM measurements to investigate morphological properties of these films, the grain size for CuxZn1-xS films differs with Cu content thru uniform distribution. UV-Vis absorption spectroscopy was used to investigation the optical characterization of CuxZn1-xS films as a function of Cu content. The direct band gap values of these films were found decrease with increasing Cu content as (2.45, 2.4, and 2.3) eV respectively and the optical constant affected with Cu content. The CuxZn1-xS films have suitable optical characteristics which can used it for solar cell applications.
A Qualitative Method for White Phosphorus Detection in South Lebanon Soils
Authors: Karnib Mona Y , Faraj Mahmoud K
Published: October 2024

White phosphorus is an explosive substance mostly used to create a dense smoke screen during conflicts. When exposed to air, it burns at extremely high temperatures and starts fires in the areas in which it is deployed. White phosphorus has detrimental effects on human health, it can cause respiratory disorders, organ failure and third degree burns. Since the start of October 2023 attacks, South Lebanon villages were hit with white phosphorus bombs which caused extensive fires and loss of agricultural fields. This paper presents a rapid qualitative method to test white phosphorus presence in soil samples taken at 5 cm and 30 cm depth from 9 villages attacked by white phosphorus bombs: Naqoura, Alma Shaab, Aita Shaab, Ramiah, Beit Leif, Rmeish, Rshaf, Kafra and Yarin. Positive results were found in Naqoura, Alma Shaab, Aita Shaab, Ramiah, Beit Leif, Rmeish and Yarin, whereas for Rshaf and Kafra, no white phosphorus was detected in our soil samples. This study provides information on white phosphorus contamination in south Lebanon soils, and sheds the light on its agricultural and environmental consequences.
Methods of Thermal Energy Storage by Using Smart Heat Pumps
Authors: Török Arpad , Feidt Michel
Published: October 2024

To address energy problems in thermodynamic installations, the authors of the paper propose a working methodology in which the determining role of the exergetic aspects of the processes is especially emphasized. One of these energy problems, addressed in many papers in recent years, is of particular importance in the fight to reduce chemical and thermal pollution of the environment: the problem of storing excess energy and energy from renewable or residual sources. Approaching this issue as well from this point of view, the authors propose a series of solutions by which they seek to use the most of the exergy extracted from the available energy sources. The solutions proposed here are based on the use of an own invention, the isothermalizer, a particularly powerful tool, able to bring highly effective solutions to many of the problems that concern researchers determined to create a cleaner planet. Designers and users of thermodynamic systems now have the possibility of an initial choice and subsequent changes (with the change of external conditions), of their energy and exergetic efficiency, as well as the possibility of calculating the material and energy costs necessary to achieve the proposed objective. In any gas compression/expansion problem, the energy efficiency is established precisely, by choosing the isothermal speed of the process (so of the isothermal temperature), and the power density, by choosing the total surface of the thermal sponge, the flow rate and the mode of distribution of the cooling agent. As the isothermalizer is equipped with a processor that controls and modifies the isothermal speed in such a way that the exergy consumption is optimized, the energy storage processes become processes of extracting thermal energy from a tank and transferring it to another tank, a process accompanied by consumption/supply of mechanical energy.
Image Matching for Multi spectral Image Satellite SIFT and Features
Authors: Ahmed Woroud F. , Abd-Almajied Mohammed I.
Published: October 2024

The Matching and registration of the satellite imagery play an essential role in many remote sensing and image processing applications. Certain steps, such as analysis of broad regions of interest and for the remotely detection. Pixel values in two or more images were play an important role in matching and detection algorithms between two or more images. In this work an image registration process (detection, extract and matching features) were utilized through using the sift algorithm to registration two image that have different resolutions (Landsat (30m) and Sentinel (10m)) utilize MATLAB program. A geometric correction was applied in this work for detect a correct points between these images. The results shows a corresponding between these two images. A preprocessing were utilized in good identifying features and accuracy of extracting information from satellite images.
Developing mathematical models to calculate annual evapotranspiration rates in Iraq using climate data.
Authors: Azeez Tabarak R. , Jowad Laith A.
Published: October 2024

Evapotranspiration is considered the fuel that controls the water cycle in the natural world. It is necessary for the stability of ecosystems and is involved in many important aspects in calculating groundwater quantities, determining optimal locations for building dams and reservoirs and knowing the water needs of crops. The work is divided into two main parts. The first includes the use of The Penman-Monteith method, which is considered the most standard method in the world according to the Food and Agriculture Organization (FAO), for calculating the annual rate of evapotranspiration in Iraq for the past fifteen years (2008-2022). The second part is a modification of a simple method for calculating evapotranspiration, which is the Thornthwaite method, to give results close to the accuracy of the Penman-Monteith method, as the modification was made using different statistical methods. The study showed the possibility of using the modified Thornthwaite method as an alternative to the Penman-Monteith method to calculate evapotranspiration in all regions of Iraq.
Advancements in CuO nanoparticle technology: synthesis, characterization of copper oxide nanoflowers
Authors: abbas Ali khudair , Al-Jawad Selma M. H. , Imran Natheer Jamal
Published: October 2024

Nanostructured materials, including metal and metal oxide nanoparticles, play a crucial role in advancing diverse scientific and technological areas. Transition metal oxides such as CuO are integral to developments in fields like antibacterial treatments, solar energy conversion, sensing technologies, catalysis, magnetic storage, supercapacitors, and semiconductor devices. This research is centered on the hydrothermal synthesis of pure copper oxide nanoflowers, which are noted for their extensive surface areas. Zeta potential analysis, ultraviolet-visible spectrophotometry, field-emission scanning electron microscopy, and Fourier-transform infrared spectroscopy were some of the methods utilized to characterize these nanoparticles. The results showed that band gap energies, crystallite size, and lattice characteristics are all greatly affected by CuO. XRD results indicated a covellite monoclinic polycrystalline structure predominantly orientation with average crystallite sizes around 15.84 nm. FE-SEM imagery depicted the hierarchical, cauliflower-like structure of the CuO nanoparticles. Optical assessments revealed band gap values ranging from 2.58 eV. The findings underscore the broad potential of CuO nanoflowers across various technological applications.
Structural, Morphological, and Optical Properties of TiO2/CdS Core-Shell System Prepared by Two Method for Photoelectrocatalytic Application
Authors: Al-Jawad Selma M.H. , Mohaisen Riyam Shakir , Imran Natheer Jamal , Mohammad Mohammad R. , Alhusseiny Abdullah , muhsen Mustafa M. , Alhusseiny Ibrahim Mohammed
Published: October 2024

The present study utilized the hydrothermal technique to carry out the deposition of films of TiO2. The deposition of CdS on the TiO2 films was accomplished using the chemical bath deposition (CBD) and successive ionic layer adsorption and reaction (SILAR) methods. The morphological and structural characteristics of the TiO2/CdS thin films were investigated using a combination of XRD, SEM, EDX, and AFM techniques. Additionally, the optical properties of the nanostructures were examined using UV-Visible and PL spectroscopic techniques. The X-Ray Diffraction pattern of all TiO2 films revealed the formation of the anatase phase. The CdS present in the Ti/TiO2/CdS samples exhibited a hexagonal structure. The hydrothermal technique employed in the preparation of the TiO2 thin films resulted in the formation of nanofiber morphology, which was evident from the SEM images. The absorption edge data for the TiO2/CdS films demonstrated a shift towards the visible region, indicating a decrease in the bandgap as compared to the TiO2 nanostructure. Significantly improved photoelectrocatalytic performance was observed in the Ti/TiO2/CdS samples prepared using the CBD method, surpassing that of the Ti/TiO2/CdS samples prepared using the SILAR method.
Investigation on Wax Deposition Risk in Shale Oil Well During Production Test
Authors: Wei Jianfei , Cao Dagui , Tao Liang , Yang Shuhui , Tan Zhenxing , Gao Yonghai , Wang Zhiyuan , Li En , Zhang Jianbo
Published: October 2024

During production test of the shale oil well, the low temperature environment in the wellbore is likely to cause wax precipitation of shale oil, and in turn disrupt the normal production test, increase the operating costs and risks. In view of this problem, by considering the gas-liquid flow, radial heat transfer and temperature gradient etc, a temperature and pressure field model of shale oil wellbore was established, and a prediction method of wax deposition zone in the shale oil wellbore during production test was proposed. Furthermore, by using the production data of a shale oil well with wax deposition in the South China Sea during production test, the accuracy of the model in calculating the fluid temperature and pressure of the wellbore with wax deposition was verified. The wellhead temperatures calculated by the model had a maximum error of 9.31%, and the bottom-hole pressures calculated by the model had a maximum error of 7.52%, indicating the model has high calculation accuracy. The model was used to analyze the sensitivities of wax deposition to the time and rate of production, water content and the ratio of gas to oil. It is found that the wax deposited in wellbore increases in thickness with the production time, is more strongly affected by production rate and water content, but less affected by the ratio of gas to oil. The research results can provide support for preventing wax deposition during production test of shale oil wells.