bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical study of flow after NASA 4412 aerodynamic profile based on the SST turbulence model
Authors: Madaliev Murodil , Mamatov Akmaljon , Otajonov Jamshidbek , Kadyrov Khasanboy , Bilolov Inomjan , Otakhanova Zamira , Muminov Kamolkhan
Published: April 2024

This article investigates the application of the SST turbulence model within the Comsol Multiphysics platform to analyze subsonic airflow around a NACA4412 airfoil at an angle of attack of 13.87 degrees. The study employs the finite element method to solve the turbulence equations numerically, with stabilization achieved through the Galerkin least squares technique. Comparisons between the computational results and experimental data are conducted to assess the model's performance. The findings demonstrate favorable agreement between the SST turbulence model predictions and experimental observations, indicating promising convergence. This research contributes to the understanding of turbulence modeling in aerodynamics simulations and underscores the potential of the SST model in accurately capturing flow behavior around complex geometries like the NACA4412 airfoil.
Methods for researching the influence of electromagnetic waves of power transmission lines on soil properties
Authors: Marupov Azizxon , Turdikulov Khusanboy , Khakimova Kamola , Abdukadirova Mukharram
Published: April 2024

This article is devoted to the study of the influence of electromagnetic waves from power lines on soil properties. With the increasing use of electricity and the expansion of electrical power infrastructure, there is increasing interest in understanding the effects of electromagnetic fields on the environment. This article provides an overview of current research methods used to assess the effects of electromagnetic waves on soil properties. Both laboratory and field approaches to studying this issue are considered, and the main results of research in this area are discussed. Understanding these relationships is key to developing effective land use management strategies and maintaining environmental sustainability in the face of modern anthropogenic impacts.
Оil- bitumum saturation Mesozoic and cenozoic deposits in central Asia
Authors: Shoimurotov Tuychi , Togaev Isamiddin , Akmalov Shamshodbek , Babajanov Farrukh , Melikuziyev Sarvar , Kasimov Shuxrat
Published: April 2024

The article discusses the distribution patterns and formation conditions of natural bitumen and high-viscosity oil accumulations in Central Asia, and gives their geochemical characteristics, classification and genetic types. Based on the analysis of the geochemical characteristics of heavy natural bitumens and high-viscosity oils within the Fergana, Afghan-Tajik, Zarafshan and Bukhara-Khiva oil and gas bearing regions (BKhOGR), four types of natural bitumen accumulations and three groups of high-viscosity oils, which differ not only by the spread area but also by the material composition of hydrocarbons, were identified. On the basis of the analysis and generalisation of the results of geochemical research within the study area, the main factors for the formation of different types of natural bitumens and high-viscosity oils in Central Asia have been identified and substantiated.
Enhancing operational characteristics and technical-economic indicators of vessels through the application of new toothed coupling designs
Authors: Savenkov Oleg , Pokuy Sergiy , Sadovoy Oleksiy , Koshkin Dmytro
Published: April 2024

This study demonstrates the potential for improving the operational characteristics and technical-economic indicators of vessels operating under conditions of misalignment of the axes of connecting shafts of marine power plants and their elements by using toothed coupling constructions with enhanced operational characteristics. The proposed couplings are designed in a way that makes them almost insensitive to the misalignment of the axes of connecting shafts, thus operating like an ideal hinge. The application of toothed couplings allows reducing the likelihood of unscheduled docking of the vessel, which, in turn, helps save significant costs for realignment and payment in case of the loss of the vessel’s transit capacity.
Solutions for contact problems applied to bevel gears
Authors: Savenkov Oleg , Voronenko Serhii , Sadovoy Oleksiy , Poltorak Anastasiya
Published: April 2024

The article presents solutions to flat contact problems applied to straight-tooth bevel gears, considering both linear and nonlinear dependencies between elastic displacements of the teeth and the resulting stresses. Maximum contact stresses and contact patch dimensions are determined, accounting for both linear and nonlinear relationships between elastic deformations of the teeth and stresses. These solutions are based on a novel contact strength theory. It is demonstrated that the load capacity of bevel gears, considering contact stresses and nonlinear dependencies between elastic deformations and stresses, increases by 1.113 times.
Method for calculating marine helical gear transmissions for contact strength
Authors: Savenkov Oleg , Radchenko Муkola , Vakhonina Larisa , Mardziavko Vitalii , Kuris Yurii
Published: April 2024

The solution to the flat contact problem is presented in relation to marine helical gear transmissions, considering the nonlinear relationship between elastic deformations of the teeth and stresses. Maximum contact stresses and contact patch sizes are determined, taking into account the nonlinearity between tooth deformations and stresses.
Energy saving using a frequency converter in asynchronous motor operating modes
Authors: Pirmatov Nurali , Xaydarov Xumoyun , Abduraxmonov Sultonali , Sayitov Shavkatjon
Published: April 2024

This scientific article discusses asynchronous motors using single-season and multi-season sizes, their optimized modes for scalar and vector control. First of all, detailed information was given about the operating modes of the optimizer, followed by changes in voltage, magnetic current and electric current. With scalar control, mode optimizers are optimized for maximum and minimum electric current, while with vector control, optimization is achieved through direct or indirect action on the rotor. Based on the above, complex optimization methods are considered in detail and graphs from their mathematical model are presented. In this case, the conditional minima of the electric current in the lower region and the local minima of the electric current in the lower region are shown on the graphs. The data obtained were compared with complex optimization and extraterrestrial characteristics. As a result of the article, the mentioned methods proposed a scheme of the final optimization structure and a system of equations that mathematically represent them all. The results obtained showed that even with the help of a simple circuit, optimal control of asynchronous motors can be achieved with good results when using optimizers of complex modes, rather than scalar or vector current control. In the future, the control of this method will become the basis for solving energy-saving problems achieved through the use in asynchronous motors with a short-circuited rotor, which are regulated by a frequency switch located in pumping plants of industrial enterprises.
To the organization the repair production of contactors for electrical equipment of diesel locomotives
Authors: Ablyalimov Oleg , Kalimbetova Zhansaya
Published: April 2024

Based on the theory of reliability and probability, taking into account the performance testing of mainline diesel locomotives at the Havast locomotive depot, a new methodology has been proposed regarding the frequency of performing a certain amount of repair work performed during the maintenance and routine repair of contactors for electrical equipment of diesel locomotives. The criterion for assessing the technical condition of an electrical contact under operating conditions is the quantitative characteristic of the contact surface in the form of the amount of burnt or melting of the contactors in the area of their contact with each other. Indicators of the frequency of technical maintenance during the repair of various types contactors of electrical equipment of mainline diesel locomotives are obtained in the form of tabular data, taking into account temporary recommendations for organizing their repair production. The results of the study are recommended for implementation into the practice of linear enterprises of the locomotive complex of the Uzbek Railway.
Frequency selection mechanism of sub-terahertz wave propagation within the sharp-coned plasma sheath
Authors: Wang Kaili , Bai Bo , Yuan Kai , Tang Rongxin
Published: April 2024

The propagation characteristics of sub-terahertz (sub-THz) waves through the sharp-coned plasma sheath are investigated, revealing a frequency selection phenomenon. Two significant electron density gradients within the sharp-coned plasma sheath, which result in high reflection coefficients, are identified. These strong reflective interfaces divide the plasma into distinct regions, and the frequency selection mechanism is analyzed using the improved scattering matrix method. This research finds that the combination of these reflective interfaces and the intervening plasma forms a “resonator structure,” leading to the observed frequency selection. A quantitative relationship between plasma parameters and the frequency selection phenomenon is analyzed. The results indicate that the reflection coefficients of the reflective interfaces increase, making the frequency selection more pronounced, when the thickness of the interfaces decreases or the peak electron density increases. In addition, a lower collision frequency leads to reduced absorption effects and a more pronounced frequency selection. The phenomenon suggests that enhancing transmissivity at lower frequencies may be feasible, providing a theoretical insight into the application of sub-THz waves in mitigating communication blackouts.
Imperfect phononic crystals work too: The effect of translational and mid-plane symmetry breaking on hypersound propagation
Authors: Babacic Visnja , Sledzinska Marianna , Vasileiadis Thomas , Sotomayor Torres Clivia M. , Graczykowski Bartlomiej
Published: April 2024

Translationally symmetric nanostructures, termed phononic crystals (PnCs), offer control over the propagation of acoustic phonons in the gigahertz (GHz) range for signal-processing applications and thermal management at sub-Kelvin temperatures. In this work, we utilize Brillouin light scattering to investigate the impact of symmetry breaking on GHz phonon propagation in PnCs made of holey silicon nanomembranes. We show that the lattice of thimble-like holes leads to broken mid-plane symmetry and, hence, to anticrossing acoustic band gaps. With the rising level of uncorrelated translational disorder, the phononic effects are gradually suppressed, starting at higher frequencies. Strikingly, the low-frequency partial Bragg bandgap remains robust up to the highest level of disorder.
Interpretably learning the critical temperature of superconductors: Electron concentration and feature dimensionality reduction
Authors: Díaz Carral Ángel , Roitegui Martín , Fyta Maria
Published: April 2024

A machine learning model for predicting the critical temperature of novel superconductors is proposed. The novelty of this approach is based solely on the choice of ab initio features, that is, descriptors directly and solely related to the electronic and atomic information of the single elements that chemically bond to form superconductors. We could show that selecting features, such as the electron concentration in the materials and the electronegativity from the available superconductor data, allows for a significant reduction in the learning dimensionality. At the same time, this choice provides a prediction accuracy in critical temperature up to 93% (relevant to a mean absolute error of 4.2 K) similar to more complex models using a significantly higher feature space. In total, the features could be reduced down to 11 in addition to the multidimensional electronic concentration (including 17 features for the atomic orbitals), emphasizing the significantly higher importance of electronegativity and electron concentration. The latter is mainly influenced by the 3s orbital followed by the 3p orbital. This choice is physically intuitive as it directly links to the electronic orbitals in the superconductors that mostly influence the learning, thus defining the accuracy of the predicted critical temperature. At the same time, the learning process is interpretable, providing a deep insight that could be proven invaluable in developing new theories on novel superconductor materials.
Intrinsic room-temperature ferromagnetism in two-dimensional ternary transition metal tellurides CrX2Te4 (X = Al, Ga, and In)
Authors: Huang He , Zhao Yanzhe , Zhang Zeyu , Wang Liming , Wu Yanfei , Liu Chuang , Zhao Jiapeng , Qiao Guanxiong , Zhang Jingyan , Zheng Xinqi , Zhou Shiming , Wang Shouguo
Published: April 2024

A tremendous amount of research has witnessed the exploration of two-dimensional (2D) materials with intrinsic ferromagnetism and diverse physical properties. However, the low Curie temperature and deficient magnetic anisotropy hinder their practical applications in nanoscale spintronics. Based on first-principles calculations, we propose a new family of 2D ternary transition metal tellurides, CrX2Te4 (X = Al, Ga, and In), with both structural and magnetic stabilities at room temperature. Our calculations demonstrate that the 2D CrX2Te4 crystal exhibits the intrinsic 100% spin-polarized half-metallic feature with spin-up metallic and spin-down semi-conducting properties. With the remarkable magnetic moment of 4 μB per Cr atom, both 2D CrAl2Te4 and CrGa2Te4 crystals perform robust ferromagnetism with the out-of-plane magnetic anisotropy, while the 2D CrIn2Te4 crystal prefers the in-plane easy magnetization axis. The Monte Carlo simulation based on the 2D Heisenberg model shows that the critical Curie temperatures of the 2D CrAl2Te4, CrGa2Te4, and CrIn2Te4 crystals could reach 466, 431, and 536 K, respectively. Moreover, the magnetic exchange strength and magnetic anisotropy could be further enhanced by the in-plane biaxial strain. The novel electronic and magnetic features promote 2D CrX2Te4 (X = Al, Ga, and In) crystals as a new family of two-dimensional intrinsic ferromagnetic materials for next-generation advanced spintronics.
Prime number factorization with light beams carrying orbital angular momentum
Authors: Li Xiaofei , Liu Xin , Wu Quanying , Zeng Jun , Cai Yangjian , Ponomarenko Sergey A. , Liang Chunhao
Published: April 2024

We point out a link between orbital angular momentum (OAM) carrying light beams and number theory. The established link makes it possible to formulate and implement a simple and ultrafast protocol for prime number factorization by employing OAM endowed beams that are modulated by a prime number sieve. We are able to differentiate factors from non-factors of a number by simply measuring the on-axis intensity of light in the rear focal plane of a thin lens focusing on a source beam. The proposed protocol solely relies on the periodicity of the OAM phase distribution, and hence, it is applicable to fully as well as partially coherent fields of any frequency and physical nature—from optical or x-ray to matter waves—endowed with OAM. Our experimental results are in excellent agreement with our theory. We anticipate that our protocol will trigger new developments in optical cryptography and information processing with OAM beams.
State of the art, trends, and opportunities for oxide epitaxy
Authors: Hensling F. V. E. , Braun W. , Kim D. Y. , Majer L. N. , Smink S. , Faeth B. D. , Mannhart J.
Published: April 2024

Oxides have attracted enormous attention for both application-driven and fundamental solid-state research owing to their broad range of unusual and unique properties. Oxides play an important role in countless applications, e.g., as catalysts or functional materials in electronic devices. The ability to produce high-quality epitaxial films is often crucial for these purposes. Various approaches to oxide epitaxy have been evolving for many years, each of which has its own features and strengths. However, oxide epitaxy also poses numerous challenges, the main ones being (1) the difficulty of finding a universal, versatile, and clean way to transfer an element from a source onto a substrate and (2) the ability to control the phase formation in a growing film. For oxides, this is an especially relevant topic due to the high oxidization potentials needed to achieve many desired compounds, the high temperatures required for numerous oxide phases to form, and the high temperatures necessary to grow films in adsorption-controlled growth modes. We provide a non-exhaustive overview of the state-of-the-art of oxide epitaxy within the context of these challenges. We also examine exciting advances and recent trends to overcome those challenges. Concluding, we discuss the implications of ongoing developments and the future of oxide epitaxy. An emphasis is put on thermal laser epitaxy and CO2 laser heaters, which we deem especially promising.
Keldysh crossover in one-dimensional Mott insulators
Authors: Shinjo Kazuya , Tohyama Takami
Published: April 2024

Recent advancements in pulse laser technology have facilitated the exploration of nonequilibrium spectroscopy of electronic states in the presence of strong electric fields across a broad range of photon energies. The Keldysh crossover serves as an indicator that distinguishes between excitations resulting from photon absorption triggered by near-infrared multicycle pulses and those arising from quantum tunneling induced by terahertz pulses. Using a time-dependent density-matrix renormalization group, we investigate the emergence of the Keldysh crossover in a one-dimensional (1D) Mott insulator. We find that the Drude weight is proportional to photo-doped doublon density when a pump pulse induces photon absorption. In contrast, the Drude weight is suppressed when a terahertz pulse introduces doublons and holons via quantum tunneling. The suppressed Drude weight accompanies glassy dynamics with suppressed diffusion, which is a consequence of strong correlations and exhibits finite polarization decaying slowly after pulse irradiation. In the quantum tunneling region, entanglement entropy slowly grows logarithmically. These contrasting behaviors between the photon-absorption and quantum tunneling regions are a manifestation of the Keldysh crossover in 1D Mott insulators and provide a novel methodology for designing the localization and symmetry of electronic states called subcycle-pulse engineering.
An LES investigation on turbulent flow in a centrifugal impeller affected by normal-distributed inflow perturbations
Authors: Yang Fengru , Zhang Wei
Published: April 2024

The inflow of a rotating centrifugal impeller is normally perturbed by an upstream stationary component; therefore, the development of turbulent flow is different from the case with steady and uniform inflow. In this work, we performed a large-eddy simulation on turbulent flow in a centrifugal impeller, considering perturbation from the inflow and emphasizing the development of perturbation and its influence on flow in the impeller. The inflow perturbation is applied for the streamwise (w-) velocity and is time-varying as generated by a random number generator. A normal-distributed pattern of perturbation is always assumed with the intensity of perturbation, defined as the ratio between the perturbation amplitude and the mean velocity, set as fv = 0%, 5%, 10%, and 20%, where fv denotes the perturbation intensity. The inflow perturbation notably affects the passage flow. The velocity fluctuation and secondary flow increase in intensity as the perturbation intensity increases from fv = 0% to 10%, while a further increase to fv = 20% slightly weakens the velocity fluctuation. Although this phenomenon is less obvious in terms of the time-averaged characteristics of velocity, the Reynolds stress terms CtCa and CrCa under time-averaging still reflect a clear variation trend, and the Reynolds stresses are observed significantly on the blade suction surface.
Study of Complex Nitrogen and Oxygen-bearing Molecules toward the High-mass Protostar IRAS 18089–1732
Authors: Manna Arijit , Pal Sabyasachi , Baug Tapas , Mondal Sougata
Published: April 2024

The observation of oxygen (O)- and nitrogen (N)-bearing molecules gives an idea about the complex prebiotic chemistry in the interstellar medium. Recent millimeter and submillimeter wavelength observations have shown the presence of complex O- and N-bearing molecules in the star formation regions. So, the investigation of those molecules is crucial to understanding the chemical complexity in the star-forming regions. In this article, we present the identification of the rotational emission lines of N-bearing molecules ethyl cyanide (

C

2

H

5

CN

) and cyanoacetylene (HC3N), and O-bearing molecule methyl formate (CH3OCHO) toward high-mass protostar IRAS 18089–1732 using the Atacama Compact Array. We also detected the emission lines of both the N- and O-bearing molecule formamide (NH2CHO) in the envelope of IRAS 18089–1732. We have detected the v = 0 and 1 state rotational emission lines of CH3OCHO. We also detected the two vibrationally excited states of HC3N (v7 = 1 and v7 = 2). The estimated fractional abundances of

C

2

H

5

CN

, HC3N (v7 = 1), HC3N (v7 = 2), and NH2CHO toward IRAS 18089–1732 are (1.40 ± 0.5) × 10−10, (7.5 ± 0.7) × 10−11, (3.1 ± 0.4) × 10−11, and (6.25 ± 0.82) × 10−11 respectively. Similarly, the estimated fractional abundances of CH3OCHO (v = 0) and CH3OCHO (v = 1) are (1.90 ± 0.9) × 10−9 and (8.90 ± 0.8) × 10−10, respectively. We also created the integrated emission maps of the detected molecules, and the observed molecules may have originated from the extended envelope of the protostar. We show that

C

2

H

5

CN

and HC3N are most probably formed via the subsequential hydrogenation of the

CH

2

CHCN

and the reaction between C2H2 and CN on the grain surface of IRAS 18089–1732. We found that NH2CHO is probably produced due to the reaction between NH2 and H2CO in the gas phase. Similarly, CH3OCHO is possibly created via the reaction between radical CH3O and radical HCO on the grain surface of IRAS 18089–1732.
Time-History Analyses on the Effect of Partial Infill Walls on the Seismic Response of a Reinforced Concrete Frame Structure
Authors: Venghiac V M , Banu O M , Taranu G , Baetu S A
Published: April 2024

Time-history analysis (THA) is based on direct step-by-step integration of the equation of motion in time domain considering as input either the recorded accelerograms of real or artificially generated earthquakes. Numerical simulations are sensitive in terms of material properties, geometry, boundary conditions and applied loading scenarios correct definition. Therefore, additional care is required in the pre-processing stage of the analysis when the numerical model is defined. Infill walls play an important role on the seismic behaviour of structures during earthquakes. The response of the structure to seismic action changes due to the presence of the infill walls. The paper presents the results obtained by means of THA on the effect of partial infill walls on the seismic response of a scaled-down RC frame structure subjected to four consecutive uniaxial seismic motions. The parameters of the research were the presence of the partial infill wall and the thickness of the wall. The obtained results are discussed from the point of view of maximum lateral displacements and response spectra expressed in terms of accelerations. The results contribute towards the setting up of the subsequent shake table tests of scaled-down RC frame models with different configurations that would validate and help calibrate the numerical model.
The impact of blast vibration on the site response
Authors: Ozkan Gulnisa , Dehghanian Kaveh
Published: April 2024

In civil engineering, one of the main problems is the stability of structures. Blast vibrations can be one of several elements influencing the stability of these structures. In order to prevent any effects on the structures, the maximum suggested values of the peak particle velocity and frequency from the blast are generally determined using the existing appropriate government rules and industry standards as reference. In this paper, the effect of these vibration on the site response has been investigated. Parameters such as peak ground acceleration, Pseudo spectral acceleration and maximum stress and strain has been compared for two different soil models. The results indicate that the soft soil has a significant impact and amplifies the input parameters considerably.
Evaluation of bridge load capacity using proof-load tests
Authors: Brinissat M , Ray R P , Kuti R
Published: April 2024

A proof-load test is often necessary to accurately measure the field behavior of a bridge structure. A new segmental steel bridge has been constructed over the Tisza River in Hungary. The bridge comprises of two independent steel box girders assembled by a welding system. Engineers performed proof load tests before opening the structure to evaluate its load-carrying capacity and deck deflection. This paper presents several aspects of the load testing and evaluation of the bridge structure under static and dynamic loads using a rating factor (RF) approach compared to a baseline finite element model. The load test results helped to calibrate the model and verify the method. The study reveals that the tested bridge has an elastic behavior, a high capacity, and adequate dynamic performance.
Finite element analysis on composite steel-concrete shear walls with centered and staggered openings
Authors: Todea V , Popescu V , Dan D , Florut S C , Stoian V
Published: April 2024

Present paper presents a comparative study made on the seismic performance of composite steel-concrete shear walls with rectangular openings, by performing numerical analyses using ATENA 3D software. Two specimens were designed at a reduced scale 1:3 having similar arrangements in the cross-section and the same geometry. First element was conceived with centered openings while the second one was designed with staggered openings. Steel connectors disposed as horizontal stiffeners were used to design and to assure the full connection between the structural steel profiles embedded in the edges and the concrete core. The openings that were considered on each story of the walls, were having the dimension of a common architectural door. A part of the results recorded from the experimental tests were used to calibrate the numerical models. This study aims to establish the seismic performance and to investigate the influence of the openings and the geometric position on the overall seismic behavior of the composite shear walls. Key parameters which describe the seismic performance of structural elements such: bearing capacity, deformation capacity, stiffness degradation, cracks and strain development are compared between the specimens and discussed. The results showed that different arrangements of the openings could significantly modify or increase the seismic performance of the composite structural walls.
A design tool for the analysis of reinforced and prestressed concrete columns
Authors: Kovacs B , Toader T-N
Published: April 2024

This article aims to describe an automatic calculation algorithm developed for the analysis of reinforced concrete and / or prestressed concrete columns. The article describes two analysis types: sectional analysis and analysis on the element. The sectional analysis consists in the generation of three characteristic curves: bending moment - curvature (M-1/r), axial force - bending moment (N-M) and bending moment – bending stiffness diagrams. The analysis on the element provides the height – displacement (H-w) diagram, obtained by using the finite element method (FEM). For the two analysis, the calculation approach and the implementation of the algorithm is briefly described by the mathematical equations used. To ease the usage of the algorithm an application was developed in MATLAB appDesigner. For validating the algorithm, the results were compared with those obtained from experimental tests in the laboratory but also with numerical simulations using commercial computational software based on FEM. MATLAB programming language was used to implement the algorithm, while results of the analysis proved to be conservative when compared to the experimental ones. Moreover, the bending moment resistance for prestressed concrete columns using bonded tendons is better estimated with at least 10% when compared with a commercial software, based on fiber-based cross-section nonlinear analysis.
The Use of Artificial Neural Network for Predicting the Thermal Conductivity of Cement Based Mortar with Natural Zeolites
Authors: Covatariu G , Toma I O , Alexa-Stratulat S M , Covatariu D , Bunea G , Olteanu I
Published: April 2024

Zeolites, in their natural state, have been used in construction materials since ancient times. The pozzolanic activity of zeolites and their use as supplementary cementitious materials has been investigated over the past three decades. The indoor comfort provided by a modern life style comes at a cost of consuming enormous amounts of energy. Materials with improved insulation properties are continuously researched and the use of zeolites showing encouraging results. The paper presents experimental results obtained on different cement-based mortar mixes incorporating natural zeolites. The main parameters of the research were: substitution of cement and sand by natural zeolites, three different replacement percentages for cement and sand (10%, 20% and 30%) and the curing age of mortar specimens (14 days, 21 days and 28 days). An artificial neural network (ANN) was developed to predict the values of the thermal conductivity by taking into account parameters such as density, humidity and surface temperature of the mortar samples. The ANN was able to accurately predict the experimental results for the thermal conductivity of cement-based mortars with natural zeolites.
Environmental and Economic Sustainability Indicators for External Walls
Authors: Miltiade P C , Baran I , Dumitrescu L , Entuc I S , Pescaru R A
Published: April 2024

The current context of the intensification of climate changes, on one hand, and the sharp increase in prices in the buildings sector, on the other, impose the need to find solutions that considers both economic and environmental protection aspects.

This paper proposes a method of evaluating the solutions most often used today in Romania for the exterior walls in single-family residential buildings based on a global index that takes into account both environmental performances (adjusted thermal resistance, carbon footprint) as well as the economic ones (costs).
Ecologization of Waste from the Steel Industry in Civil Engineering Works
Authors: Iriciuc S C , Gimiga G R , Găluşcă N I , Dima D N , Scutaru M C , Boacă Gh
Published: April 2024

The massive industrialization of the last century has come with the drawback of creating large waste deposits. Over the past century, steel mills have generated significant quantities of steel slag, deposited in heaps that occupy vast land areas. The desire to recycle steel slag arises from both ecological and economic interests. To achieve this goal in the steel industry, it was necessary to recycle steel slag (waste from the technological process of steel production) by using them as aggregates in civil constructions. In this work, the optimal option will be determined based on the mathematical modelling of the main physical-mechanical characteristics of the asphalt mixtures used in wear layers made with steel slag aggregates in comparison with classic asphalt mixtures.
Improving pressure monitoring and control in order to reduce water loss in water urban public systems
Authors: Stătescu F , Boboc V , Tatu G , Sârbu G C , Marcoie N , Toma D
Published: April 2024

Water losses from distribution systems are present in all situations. Reducing them to zero is impossible. Modern technologies for operating water distribution networks are an effective means of reducing water losses. In this sense, the conducted research aimed at testing some solutions to improve the monitoring and control of pressure in a distribution network. The mathematical model of the water distribution network was developed and calibrated (Mike Urban application) and the hydraulic modeling of the network was carried out. The results were obtained through: periodic simulations with the help of the monitoring application; comparisons for flow and pressure values, data collected from field measurements, data obtained from SCADA application. These complex analyzes allow the identification, in the shortest possible time, of existing problems and areas with losses.
Hydrodynamic modelling and simulation of the variation of the water quality parameters of the Bahlui River
Authors: Tătaru L , Hrăniciuc T A , Stătescu F , Marcoie N , Vârlan (Toma) C M , Mitroi R.
Published: April 2024

For the simulation of hydrodynamic changes and pollutant dispersion in the study area, an appropriate model was applied using the DHI series software. Flows were modelled using the hydrodynamic model and the hydrological model, and water quality was modelled using MIKE 11 ECO LAB. The paper presents a simulation for the water quality of the Bahlui River. Mike 11 contains a GIS map and simulation editors. Water quality parameters such as temperature, dissolved oxygen and biochemical oxygen demand were simulated. Modelling results can be used as a planning tool to help decision makers during different phases.
Structural distortion and dynamical electron correlation driven enhanced ferromagnetism in Ni-doped two-dimensional Fe5GeTe2 beyond room temperature
Authors: Ghosh Sukanya , Ershadrad Soheil , Sanyal Biplab
Published: April 2024

Achieving beyond room-temperature ferromagnetism in two-dimensional (2D) magnets is immensely desirable for spintronic applications. Fe5GeTe2 is an exceptional van der Waals metallic ferromagnet due to its tunable physical properties and relatively higher Curie temperature (

T

C

) than other 2D magnets. Using density functional theory combined with dynamical electron correlation and Monte Carlo simulations, we find the

T

C

of (Fe

1
−
δ

Ni

δ

)

5

GeTe2 monolayer can increase up to ∼400 K at

δ
∼
0.20

(δ: fractional occupation). Two specific Fe sublattices are identified to be the most energetically preferred sites to host Ni. Exchange interactions between particular Fe pairs play a dominating role in controlling

T

C

, influenced by the dopant-induced structural distortions. Dynamical electron correlation induces site- and orbital-specific quasi-particle mass of Fe-d states with varying Ni concentrations. This work provides fundamental insights into 2D magnetism as an interplay of structural and electronic aspects and would guide to tailoring exciting magnetic phenomena in similar systems.
A hybrid 1D CNN-BiLSTM model for epileptic seizure detection using multichannel EEG feature fusion
Authors: Ravi Swathy , Radhakrishnan Ashalatha
Published: April 2024

Epilepsy, a chronic non-communicable disease is characterized by repeated unprovoked seizures, which are transient episodes of abnormal electrical activity in the brain. While Electroencephalography (EEG) is considered as the gold standard for diagnosis in current clinical practice, manual inspection of EEG is time consuming and biased. This paper presents a novel hybrid 1D CNN-Bi LSTM feature fusion model for automatically detecting seizures. The proposed model leverages spatial features extracted by one dimensional convolutional neural network and temporal features extracted by bi directional long short-term memory network. Ictal and inter ictal data is first acquired from the long multichannel EEG record. The acquired data is segmented and labelled using small fixed windows. Signal features are then extracted from the segments concurrently by the parallel combination of CNN and Bi-LSTM. The spatial and temporal features thus captured are then fused to enhance classification accuracy of model. The approach is validated using benchmark CHB-MIT dataset and 5-fold cross validation which resulted in an average accuracy of 95.90%, with precision 94.78%, F1 score 95.95%. Notably model achieved average sensitivity of 97.18% with false positivity rate at 0.05/hr. The significantly lower false positivity and false negativity rates indicate that the proposed model is a promising tool for detecting seizures in epilepsy patients. The employed parallel path network benefits from memory function of Bi-LSTM and strong feature extraction capabilities of CNN. Moreover, eliminating the need for any domain transformation or additional preprocessing steps, model effectively reduces complexity and enhances efficiency, making it suitable for use by clinicians during the epilepsy diagnostic process.
Entanglement entropy of the maximum geminal of the BCS ground state
Authors: Higuchi Katsuhiko , Tanno Itsuki , Ito Ryo , Higuchi Masahiko
Published: April 2024

From the viewpoint of the Bose–Einstein condensation (BEC) of the fermion system, the maximum geminal of the second-order reduced density matrix of the superconducting state exactly corresponds to the Cooper pair. In this paper the entanglement entropy (EE) for the maximum geminal of the BCS ground state is evaluated. The EE behaves logarithmically with respect to the number of the maximum geminal. Furthermore, the disappearance point of superconductivity is defined on the basis of the fermion BEC. In the superconducting ground state, almost all electrons in the energy width of the gap parameter near the Fermi level are condensed as a maximum geminal. They suddenly change to normal electrons with a finite gap of the EE at the disappearance point like a first-order phase transition.
Site-selective cobalt substitution in La–Co co-substituted magnetoplumbite-type ferrites: 59Co-NMR and DFT calculation study
Authors: Nakamura Hiroyuki , Ohta Hiroto , Kobayashi Ryuya , Waki Takeshi , Tabata Yoshikazu , Ikeno Hidekazu , Mény Christian
Published: April 2024

The La–Co co-substituted magnetoplumbite-type (M-type) ferrites AFe12O19 (A = Ca, Sr and Ba, ion sizes Ca2+

<

Sr2+

<

Ba2+) with Co compositions around 0.2 have been subjected to 59Co-NMR. The results show that Co occupies the 4f1, 2a and 12k sites, and that the smaller the A ion, the more Co tends to occupy the 4f1 minority spin site, which is effective in enhancing both uniaxial anisotropy and magnetisation. First-principles total energy calculations based on density functional theory (DFT) of undoped AFe12O19 and a supercell (

2
×
2
×
1

of the unit cell) in which 1/96 of Fe3+ is replaced by Co2+ were performed to predict the stable structure and Co occupancy sites. The results show that regardless of A, Co is most stable when it occupies the 4f1 site, followed by the 2a and 12k sites with energy differences on the order of 100 meV, and Co practically does not occupy the 2b and 4f2 sites. As the A ion becomes smaller, the energy difference when Co occupies each Fe site tends to increase, and the Co occupancy of the 4f1 site also increases. The site selectivity of Co can be roughly explained as a result of the difference in uniaxial strain along the c-axis associated with the difference in A. However, the influence of the A ion differs between the R and S blocks and the local strain also has a secondary effect on the Co distribution. Based on these results, the guidelines for improving the performance (anisotropy and magnetisation) of La–Co co-substituted M-type ferrite magnets with a limited amount of Co can be summarised as follows: It is effective to select as small A ions as possible and to post-anneal at low temperature or cool slowly to concentrate Co at the 4f1 site in tetrahedral coordination.
Participatory research in energy justice: guiding principles and practice
Authors: Castro-Diaz Laura , Nwadiaru Ogechi Vivian , Roque Anaís , Caverly Nick , Kenner Ali , Harper Krista
Published: April 2024

This perspective explores the imperative role of participatory research (PR) in advancing energy justice. We argue that using PR methods and principles at the intersection of energy and equity is a critical research advantage. Here, we contend that PR frameworks are integral to bridging the gap between energy justice theory and practice, emphasizing the need to move beyond decontextualized principles to address specific injustices related to race, class, gender, and coloniality. We present three energy justice case studies that used participatory approaches in diverse contexts: Amazon, Brazil; Philadelphia, Pennsylvania, USA; and Holyoke, Massachusetts, USA. These cases showcase the versatility of PR methods in understanding and addressing unique energy challenges within local communities. We highlight guiding principles of PR, emphasizing the importance of prioritizing community needs, respecting diverse expertise, building trust, designing for transparency and accountability, choosing appropriate methods, adapting and being flexible, and aiming for long-term collaboration. Lastly, our perspective suggests future directions for participatory energy justice research, including the potential for PR to inform multiscalar policy, practice, and advocacy. We underscore the importance of collaborations between university researchers and community organizations through citizen science, emphasizing the need for diverse disciplinary perspectives to effectively address complex energy justice challenges.
DNA double-stranded breaks, a hallmark of aging, defined at the nucleotide resolution, are increased and associated with transcription in the cardiac myocytes in LMNA-cardiomyopathy
Authors: Cathcart Benjamin , Cheedipudi Sirisha M , Rouhi Leila , Zhao Zhongming , Gurha Priyatansh , Marian Ali J
Published: April 2024

Aims

An intrinsic feature of gene transcription is the formation of DNA superhelices near the transcription bubble, which are resolved upon induction of transient double-stranded breaks (DSBs) by topoisomerases. Unrepaired DSBs are pathogenic as they lead to cell cycle arrest, senescence, inflammation, and organ dysfunction. We posit that DSBs would be more prevalent at the genomic sites that are associated with gene expression. The objectives were to identify and characterize genome-wide DSBs at the nucleotide resolution and determine the association of DSBs with transcription in cardiac myocytes.

Methods and results

We identified the genome-wide DSBs in ∼1 million cardiac myocytes per heart in three wild-type and three myocyte-specific LMNA-deficient (Myh6-Cre:LmnaF/F) mice by END-Sequencing. The prevalence of DSBs was 0.8% and 2.2% in the wild-type and Myh6-Cre:LmnaF/F myocytes, respectively. The END-Seq signals were enriched for 8 and 6764 DSBs in the wild-type and Myh6-Cre:LmnaF/F myocytes, respectively (q < 0.05). The DSBs were preferentially localized to the gene regions, transcription initiation sites, cardiac transcription factor motifs, and the G quadruplex forming structures. Because LMNA regulates transcription through the lamin-associated domains (LADs), we defined the LADs in cardiac myocytes by a Cleavage Under Targets & Release Using Nuclease (CUT&RUN) assay (N = 5). On average there were 818 LADs per myocyte. Constitutive LADs (cLADs), defined as LADs that were shared by at least three genomes (N = 2572), comprised about a third of the mouse cardiac myocyte genomes. Transcript levels of the protein-coding genes located at the cLADs (N = 3975) were ∼16-fold lower than those at the non-LAD regions (N = ∼17 778). The prevalence of DSBs was higher in the non-LAD as compared to the cLAD regions. Likewise, DSBs were more common in the loss-of-LAD regions, defined as the genomic regions in the Myh6-Cre:LmnaF/F that were juxtaposed to the LAD regions in the wild-type myocytes.

Conclusion

To our knowledge, this is the first identification of the DSBs, at the nucleotide resolution in the cardiovascular system. The prevalence of DSBs was higher in the genomic regions associated with transcription. Because transcription is pervasive, DSBs are expected to be common and pathogenic in various states and aging.
The use of diagnostic complex robotic-assisted segmentectomy in the management of incidental and screen-detected pulmonary nodules
Authors: Lee Michelle , Santhirakumaran Gowthanan , Waller David , Elkhouly Ahmed , Dhanji Al-Rehan , Wilson Henrietta , Stamenkovic Steven
Published: April 2024

OBJECTIVES

Robotic-assisted thoracoscopic surgery (RATS) facilitates complex pulmonary segmentectomy which offers one-stage diagnostic and therapeutic management of small pulmonary nodules. We aimed to explore the potential advantages of a faster, simplified pathway and earlier diagnosis against the disadvantages of unnecessary morbidity in benign cases.

METHODS

In an observational study, patients with small, solitary pulmonary nodules deemed suspicious of malignancy by a multidisciplinary team were offered surgery without a pre or intraoperative biopsy. We report our initial experience with RATS complex segmentectomy (using >1 parenchymal staple line) to preserve as much functioning lung tissue as possible.

RESULTS

Over a 4-year period, 245 RATS complex segmentectomies were performed; 140 right: 105 left. A median of 2 (1–4) segments was removed. There was no in-hospital mortality and no requirement for postoperative ventilation. Complications were reported in 63 (25.7%) cases, of which 36 (57.1%) were hospital-acquired pneumonia. A malignant diagnosis was found in 198 (81%) patients and a benign diagnosis in 47 (19%). The malignant diagnoses included: adenocarcinoma in 136, squamous carcinoma in 31 and carcinoid tumour in 15. The most frequent benign diagnosis was granulomatous inflammation in 18 cases.

CONCLUSIONS

RATS complex segmentectomy offers a precise, safe and effective one-stop therapeutic biopsy in incidental and screen-detected pulmonary nodules.