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Search results for: shape memory alloys
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Using GPUs for Parallel Stencil Computations in Relativistic Hydrodynamic Simulation
PublicationThis paper explores the possibilities of using a GPU for complex 3D finite difference computation. We propose a new approach to this topic using surface memory and compare it with 3D stencil computations carried out via shared memory, which is currently considered to be the best approach. The case study was performed for the extensive computation of collisions between heavy nuclei in terms of relativistic hydrodynamics.
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Optimization of parallel implementation of UNRES package for coarse‐grained simulations to treat large proteins
PublicationWe report major algorithmic improvements of the UNRES package for physics-based coarse-grained simulations of proteins. These include (i) introduction of interaction lists to optimize computations, (ii) transforming the inertia matrix to a pentadiagonal form to reduce computing and memory requirements, (iii) removing explicit angles and dihedral angles from energy expressions and recoding the most time-consuming energy/force terms...
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Characterizing the Scalability of Graph Convolutional Networks on Intel® PIUMA
PublicationLarge-scale Graph Convolutional Network (GCN) inference on traditional CPU/GPU systems is challenging due to a large memory footprint, sparse computational patterns, and irregular memory accesses with poor locality. Intel’s Programmable Integrated Unffied Memory Architecture (PIUMA) is designed to address these challenges for graph analytics. In this paper, a detailed characterization of GCNs is presented using the Open-Graph Benchmark...
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Polityki pamięci i tożsamości wobec (nie)chcianego dziedzictwa. Od Gdańska do Gdańzigu
PublicationCelem artykułu jest próba odpowiedzi na pytanie, jak w zależności od polityki pamięci, pamięci zbiorowej i kultury historycznej kształtowano fizyczną przestrzeń miasta i jego obraz. Z przeprowadzonych dotychczas analiz wynika, że sposób, w jaki budowano narracje tożsamościowe, oparty był zasadniczo na konstrukcjach mitotwórczych, zwłaszcza na micie XVI–XVII-wiecznego „złotego wieku”. W Gdańsku, ze względu na bogatą przeszłość historyczną...
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The Effect of Increasing the Amount of Indium Alloying Material on the Efficiency of Sacrificial Aluminium Anodes
PublicationAl-Zn-In alloys having 4.2% zinc content and various indium content in the range of 0.02–0.2% were tested with respect to the most important electrochemical properties of sacrificial anodes in a cathodic protection, i.e., the current capacity and potential of the operating anode. The distribution of In and Zn in the tested alloys was mapped by means of the EDX technique, which demonstrated that these elements dissolve well in the...
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Alireza Tabrizikahou Master of Science
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Alternative Approach to Convolution Term of Viscoelasticity in Equations of Unsteady Pipe Flow
PublicationIn the paper the selected aspects concerning description of viscoelastic behavior of pipe walls during unsteady flow are analyzed. The alternative convolution expression of the viscoelastic term is presented and compared with the corresponding term referring to unsteady friction. Both approaches indicate similarities in the forms of impulse response functions and the parameter properties. The flow memory was introduced into convolution...
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Neural network agents trained by declarative programming tutors
PublicationThis paper presents an experimental study on the development of a neural network-based agent, trained using data generated using declarative programming. The focus of the study is the application of various agents to solve the classic logic task – The Wumpus World. The paper evaluates the effectiveness of neural-based agents across different map configurations, offering a comparative analysis to underline the strengths and limitations...
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Environmental Policy
e-Learning CoursesThis course deals with key issues associted with understanding and shaping the environmental policy. Both the general description of the topic and detailed considerations regarding how to shape and execute the environmental policies at the municpal level will be discussed
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Effect of electron count and chemical complexity in the Ta-Nb-Hf-Zr-Ti high-entropy alloy superconductor
PublicationHigh-entropy alloys are made from random mixtures of principal elements on simple lattices, stabilized by a high mixing entropy. The recently discovered body-centered cubic (BCC) Ta-Nb-Hf-Zr-Ti high-entropy alloy superconductor appears to display properties of both simple crystalline intermetallics and amorphous materials; e.g., it has a well-defined superconducting transition along with an exceptional robustness against disorder....
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Time versus space trade-offs for randezvous in trees
PublicationTwo identical (anonymous) mobile agents start from arbitrary nodes of an unknown tree and have to meet at some node. Agents move in synchronous rounds: in each round an agent can either stay at the current node or move to one of its neighbors. We consider deterministic algorithms for this rendezvous task. The main result of this paper is a tight trade-off between the optimal time of completing rendezvous and the size of memory...
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Tożsamość i przestrzeń. Wokół gdańskich retoryk tożsamościowych
PublicationW długim procesie kształtowania tożsamości Gdańska ważną rolę odgrywają pamięć i przestrzeń. W nowym dyskursie tożsamościowym nie tracą one na znaczeniu, lecz obok stałych fundamentów narracji tożsamościowej (wielokulturowość, architektura, pamięć), pojawiają się nowe opowieści miejskie obejmujące różne wymiary refleksji wskazujące na złożoność: wielowymiarowość i wielowarstwowość gdańskich tożsamości. W pamięci zbiorowej gdańszczan...
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On thermal stability of topological qubit in Kitaev's 4D model
PublicationWe analyse stability of the four-dimensional Kitaev model-a candidate for scalable quantum memory - in finite temperature within the weak coupling Markovian limit. It is shown that, below a critical temperature, certain topological qubit observables X and Z possess relaxation times exponentially long in the size of the system. Their construction involves polynomial in system size algorithm which uses as an input the results of...
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Ocena odporności na zużycie ścierne stopów Ti na elementy pary trącej endoprotez stawu kolanowego
PublicationNajczęściej stosowanym biomateriałem tytanowym na elementy endoprotez stawu kolanowego jest stop Ti6Al4V. Z uwagi na zawartość wanadu, zaliczanego do pierwiastków o dużej toksyczności podejmowane są działania w kierunku zastąpienia wskazanego stopu - stopami bezwanadowymi. Jednym z najbardziej obiecujących jest stop Ti13Nb13Zr zawierający w swoim składzie jedynie pierwiastki witalne, niewywołujące stanów zapalnych i odczynów...
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Unsupervised machine-learning classification of electrophysiologically active electrodes during human cognitive task performance
PublicationIdentification of active electrodes that record task-relevant neurophysiological activity is needed for clinical and industrial applications as well as for investigating brain functions. We developed an unsupervised, fully automated approach to classify active electrodes showing event-related intracranial EEG (iEEG) responses from 115 patients performing a free recall verbal memory task. Our approach employed new interpretable...
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Colvolutional calibration of AFM probe
Open Research DataAtomic force microscopy is based on the interaction of the examined surface with a probe of a pyramidal shape, tipped with a sharp end with a radius of curvature ranging from single nanometers to hundreds of nanometers. The resolution of the obtained image is of course dependent on the above-mentioned geometric size, and the resulting image is a convolutional...
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Influence of the Tool Rotational Speed on Physical and Chemical Properties of Dissimilar Friction-Stir-Welded AA5083/AA6060 Joints
PublicationAluminum alloys have been successfully used in the railroad and automotive industries because of their potential to significantly reduce component weights, and their good mechanical and anti-corrosion properties. Problems with joining aluminum alloys are characterized by low weldability, which influences the need for studies focused on unconventional methods. The environmentally friendly and low-cost friction-stir-welding method...
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Context Search Algorithm for Lexical Knowledge Acquisition
PublicationA Context Search algorithm used for lexical knowledge acquisition is presented. Knowledge representation based on psycholinguistic theories of cognitive processes allows for implementation of a computational model of semantic memory in the form of semantic network. A knowledge acquisition using supervised dialog templates have been performed in a word game designed to guess the concept a human user is thinking about. The game,...
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Nanotubular oxide layer formed on helix surfaces of dental screw implants - SEM examination
Open Research DataThe samples used for the research had the shape of a helix with a metric thread, with their geometry imitating a dental implant. The oxide layer was produced by a standard electrochemical method in an environment of 1M H3PO4 + 0.3 % HF for 20 min, at a constant voltage of 30 V. The oxidized samples were analyzed with a scanning electron microscope.
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Massively parallel linear-scaling Hartree–Fock exchange and hybrid exchange–correlation functionals with plane wave basis set accuracy
PublicationWe extend our linear-scaling approach for the calculation of Hartree–Fock exchange energy using localized in situ optimized orbitals [Dziedzic et al., J. Chem. Phys. 139, 214103 (2013)] to leverage massive parallelism. Our approach has been implemented in the ONETEP (Order-N Electronic Total Energy Package) density functional theory framework, which employs a basis of non-orthogonal generalized Wannier functions (NGWFs) to achieve...
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Sathwik Prathapagiri
PeopleSathwik was born in 2000. In 2022, he completed his Master’s of Science in Biological Sciences and Bachelor’s of Engineering in Chemical Engineering in an integrated dual degree program from Birla Institute Of Technology And Science, Pilani, India. During his final year, he worked as a research intern under Dr Giri P Krishnan at Bazhenov lab, University of California San Diego school of medicine to pursue his Master’s Thesis on...
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Shaping of the workpiece surface in single-disc lapping
PublicationShape errors of the tool exert a dominant influence on the shape accuracy of the workpiece. The correlation between flatness errors of the lap and flatness errors of the workpieces was checked experimentally and determined analytically. Computer model of the workpiece shaping by lapping was developed. Evaluation method of the workpiece orientation as well as some simulation results for a lap with shape errors of convexity and cincavity...
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Five-phase induction motor drive with sine-wave filter
PublicationThe paper presents closed loop ac drive with 5 phase induction motor operating with voltage source inverter and sine wave filter. The motor supply voltages and currents have sinusoidal shape. For well known adjustable electric drives the field oriented control method with flux and speed co ntrol can be applied. In the presence of output filter both control and estimation algorithms should be modified due to sine wave filter installation....
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Mechanical and Corrosion Properties of Laser Surface-Treated Ti13Nb13Zr Alloy with MWCNTs Coatings
Publication: Titanium and its alloys is the main group of materials used in prosthetics and implantology. Despite their popularity and many advantages associated with their biocompatibility, these materials have a few significant disadvantages. These include low biologic activity—which reduces the growth of fibrous tissue and allows loosening of the prosthesis—the possibility of metallosis and related inflammation or other allergic reactions,...
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Gaining knowledge through experience: developing decisional DNA applications in robotics
PublicationOmówiono nowatorskie podejscie do zastosowania wiedzy opartej na doświadczeniu i budowie decyzyjnego DNA w obszarach związanych z robotyką.In this article, we explore an approach that integrates Decisional DNA, a domain-independent, flexible, and standard knowledge representation structure, with robots in order to test the usability and suitability of this novel knowledge representation structure. Core issues in using this Decisional...
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Hybridized Space-Vector Pulsewidth Modulation for Multiphase Two-Level Voltage Source Inverter
PublicationIn space vector pulsewidth modulation (SVPWM) algorithms for multiphase two-level voltage source inverters (VSI), the components of active vectors in all orthogonal spaces have to be calculated within the processor and stored in its memory. These necessitate intensive computational efforts of the processor and large memory space. This article presents a hybridized SVPWM for multiphase two-level VSI. In this algorithm, elements...
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The Effect of Sodium Tetrafluoroborate on the Properties of Conversion Coatings Formed on the AZ91D Magnesium Alloy by Plasma Electrolytic Oxidation
PublicationMagnesium and its alloys are widely used in many areas because of their light weight, excellent dimensional stability, and high strength-to-weight ratio. However, the material exhibits poor wear and corrosion resistance, which limits its use. Plasma electrolytic oxidation (PEO) is an effective surface modification method for producing ceramic oxide layers on Mg and their alloys. The influence of the additions of sodium tetrafluoroborate...
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Dilemmas of Identity in Contemporary Cities. The City of Gdansk as an Example
PublicationThe article is aimed to answer the question how, depending on the historical heritage, the collective memory, the physical space of the city and their images were shaped, through the politics of memory. All known cultures and languages distinguish the ‘self’ and the ‘other’, ‘us’ and ‘them’. Neither do we know cities which wish to differ in some particular way, although they can have numerous identities. Their multitude and diversity...
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Parallelization of large vector similarity computations in a hybrid CPU+GPU environment
PublicationThe paper presents design, implementation and tuning of a hybrid parallel OpenMP+CUDA code for computation of similarity between pairs of a large number of multidimensional vectors. The problem has a wide range of applications, and consequently its optimization is of high importance, especially on currently widespread hybrid CPU+GPU systems targeted in the paper. The following are presented and tested for computation of all vector...
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Smaller Representation of Finite State Automata
PublicationThis paper is a follow-up to Jan Daciuk's experiments on space-effcient finite state automata representation that can be used directly for traversals in main memory. We investigate several techniques of reducing memory footprint of minimal automata, mainly exploiting the fact that transition labels and transition pointer offset values are not evenly distributed and so are suitable for compression. We achieve a gain of around 20-30%...
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Determining the optimal filling of the surface with a linker with Universal Force Field and Reax Force Field
Open Research DataThe DataSet contains the atomic slabs of diamond surfaces with ATP molecules in water. The calculated data includes different sized surfaces from 90 Angstrom^2 to 691 Angstrom^2. Structures were relaxed using the Reax Force Field method with the Limited Memory Broyden–Fletcher–Goldfarb–Shanno algorithm. Structures were calculated with a convergence...
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Rotor Blade Geometry Optimisation in Kaplan Turbine
PublicationThe paper presents the description of method and results of rotor blade shape optimisation. The rotor blading constitutes a part ofturbine flow path. Optimisation consists in selection of the shape that minimises ratio of polytrophic loss. Shape of the blade isdefined by the mean camber line and thickness of the airfoil. Thickness is distributed around the camber line based on the ratio ofdistribution. Global optimisation was done...
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Conducting polymer films for biodegradable metallic cardiovascular stents
PublicationIn recent years, there is increasing interest to create biodegradable metallic cardiovascular stents instead of using their permanent form. The most interesting materials for this purpose are iron and its alloys. However, in order to use it in clinical application, their degradation rate and biological performance need to be optimized. One promising solution is coating the metal with conducting polymer films. In this work, short...
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Emotion Recognition
Open Research DataThe films presented here were recorded using so-called high-speed camera Phantom Miro. To play the movie You need the special software which can be downloaded from the web site https://www.phantomhighspeed.com/resourcesandsupport/phantomresources/pccsoftware the details of the movie are available after starting the movie in the viewer in the description...
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Emotion Recognition
Open Research DataThe films presented here were recorded using so-called high-speed camera Phantom Miro. To play the movie You need the special software which can be downloaded from the web site https://www.phantomhighspeed.com/resourcesandsupport/phantomresources/pccsoftware the details of the movie are available after starting the movie in the viewer in the description...
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Selective Laser Melting of Ti Alloy for Manufacturing The Prosthetic Elements
PublicationThe selective laser melting (SLM) is the additive manufacturing method of custom-designed parts. The used materials and the applications are various, including medicine. The titanium and its alloys are materials for which the dimensional quality, surface smoothness and no or extremely low porosity are difficult to reach. In this paper, the successful attempt to obtain by SLM the individually designed prosthetic bridges is described....
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Smaller representation of finite state automata
PublicationThis paper is a follow-up to Jan Daciuk's experiments on space-efficient finite state automata representation that can be used directly for traversals in main memory (Daciuk, 2000)[4]. We investigate several techniques for reducing memory footprint of minimal automata, mainly exploiting the fact that transition labels and transition pointer offset values are not evenly distributed and so are suitable for compression. We achieve...
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Study of Metrological Properties of Voltammetric Electrodes in the Time Domain
PublicationMetrological properties of voltammetric electrodes, in the situation where on their surface an electrochemical reaction of oxidizing/reduction takes place, were analyzed in this chapter. The properties of electrodes on which a reaction controlled by ion transport process takes place were taken into consideration. Also, it was analyzed how the electrode’s shape and the voltage polarizing the electrode influence this electrode’s...
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GPU-Accelerated Finite-Element Matrix Generation for Lossless, Lossy, and Tensor Media [EM Programmer's Notebook]
PublicationThis paper presents an optimization approach for limiting memory requirements and enhancing the performance of GPU-accelerated finite-element matrix generation applied in the implementation of the higher-order finite-element method (FEM). It emphasizes the details of the implementation of the matrix-generation algorithm for the simulation of electromagnetic wave propagation in lossless, lossy, and tensor media. Moreover, the impact...
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Recurrent Neural Network Based Adaptive Variable-Order Fractional PID Controller for Small Modular Reactor Thermal Power Control
PublicationThis paper presents the synthesis of an adaptive PID type controller in which the variable-order fractional operators are used. Due to the implementation difficulties of fractional order operators, both with a fixed and variable order, on digital control platforms caused by the requirement of infinite memory resources, the fractional operators that are part of the discussed controller were approximated by recurrent neural networks...
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Efficient model order reduction for FEM analysis of waveguide structures and resonators
PublicationAn efficient model order reduction method for three-dimensional Finite Element Method (FEM) analysis of waveguide structures is proposed. The method is based on the Efficient Modal Order Reduction (ENOR) algorithm for creating macro-elements in cascaded subdomains. The resulting macro-elements are represented by very compact submatrices, leading to significant reduction of the overall number of unknowns. The efficiency of the model...
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FDTD Method for Electromagnetic Simulations in Media Described by Time-Fractional Constitutive Relations
PublicationIn this paper, the finite-difference time-domain (FDTD) method is derived for electromagnetic simulations in media described by the time-fractional (TF) constitutive relations. TF Maxwell’s equations are derived based on these constitutive relations and the Grünwald–Letnikov definition of a fractional derivative. Then the FDTD algorithm, which includes memory effects and energy dissipation of the considered media, is introduced....
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An influence of the ship's block coefficient implementation on the evaluation of it's hull girder bending
PublicationAn influence of the three different ways of implementation ship's block coefficient δ (three geometrical models) on the stresses due to wave bending moment have been investigated. Two models have been applied and compared: beam one (description of the shape usingparameters) and FEM shell model (direct representation of the shape). The outcomes have been compared to Polish Register of Shipping (PRS) rules. The results show that...
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Detailed results of shaping personnel risk factors in enterprise D
Open Research DataThe data presents the shape of all the researched personnel risk factors in the D enterprise (which was tested by the author). Further considerations should be started with the presentation of the synthesis of the obtained results, which is presented in this research data.
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Electrophoretic deposition (EPD) of nanohydroxyapatite - nanosilver coatings on Ti13Zr13Nb alloy
PublicationTitanium and its alloys are the biomaterials most frequently used in medical engineering, especially as parts of orthopedic and dental implants. The surfaces of titanium and its alloys are usually modified to improve their biocompatibility and bioactivity, for example, in connection with the deposition of hydroxyapatite coatings. The objective of the present research was to elaborate the technology of electrophoretic deposition...
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Objective Programming EMSS 2023
e-Learning CoursesTheory and practice on object oriented programmingSoftware programming paradigms including object oriented approachEncapsulation, inheritance, abstraction and polymorphism in C++ languageSpecific features of C++ obiect-orientationDynamic memory management in C++ languagePython as a scripting object oriented languageComparison of C++ and Python languages to Java and C#
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Investigation of Parallel Data Processing Using Hybrid High Performance CPU + GPU Systems and CUDA Streams
PublicationThe paper investigates parallel data processing in a hybrid CPU+GPU(s) system using multiple CUDA streams for overlapping communication and computations. This is crucial for efficient processing of data, in particular incoming data stream processing that would naturally be forwarded using multiple CUDA streams to GPUs. Performance is evaluated for various compute time to host-device communication time ratios, numbers of CUDA streams,...
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Environmental degradation of titanium alloy in artificial saliva
PublicationThe titanium and its alloys are potentially prone to hydrogen embrittlement, including those proposed for dental implants. The research has been aimed to assess a susceptibility to environment-enhanced degradation of the Ti-13Zr-13Nb alloy in artificial saliva with or without hydrofluoric acid, subject or not to cathodic polarisation. The results have shown that even if artificial saliva is safe environment, both cathodic polarization...
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Fatigue life prediction of notched components under size effect using strain energy reformulated critical distance theory
PublicationNotch and size effects show significant impact on the fatigue performance of engineering components, which deserves special attention. In this work, a strain energy reformulated critical distance theory was developed for fatigue life prediction of notched components under size effect. Experimental data of different notched specimens manufactured from GH4169, TC4, TC11 alloys and low carbon steel En3B were used for model validation...
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Cyclic voltammetry curves of the V2O5 nanorods (Li-ion batteries)
Open Research DataThe DataSet contains the next thirty cycles voltammetry curves for the V2O5 nanocrystals obtained by the sol-gel method. The cyclic voltammetry was measured using the AUTOLAB 302N potentiostat-galvanostat. The measurements were carried out in a voltage range of 2 V to 4 V vs. Li/Li+ at a scan rate of 1 mV/s. The results show that in the subsequent cycles,...