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Search results for: ORTHOTROPIC COSSERAT COSSERAT LAMINATES CHARACTERISTIC LENGTH DRILLING ROTATION DOF IRREGULAR SHELLS
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The database of indices computed from RR-intervals of length 512 of 46 healthy subjects at rest
Open Research DataThis dataset contains the data that was a basis for the results discussed in the paper “Persistent homology as a new method of the assessment of heart rate variability” by Grzegorz Graff, Beata Graff, Paweł Pilarczyk, Grzegorz Jabłoński, Dariusz Gąsecki, Krzysztof Narkiewicz, Plos One (2021), DOI: 10.1371/journal.pone.0253851.
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Koncepcja Smart Cities - obszar Smart Environment
PublicationThe Smart Cities Concept– Smart Environment. The paper concentrates on the possibilities of checking the extent to which cities meet the smart city concept. The presented concept concentrates on one of the main smart cities characteristic: Smart Environment. This paper is a result of joint work of specialist from two diff erent areas: management and environmental protection. The interdisciplinary character of the paper is characteristic...
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Risk factors for serious morbidity, prolonged length of stay and hospital readmission after laparoscopic appendectomy - results from Pol-LA (Polish Laparoscopic Appendectomy) multicenter large cohort study
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Radar technique in application of interlayer identification connections
PublicationOne of important issues in pavement construction is to ensure that layers applied directly one on top of the other make up a continuous whole and form an integral construction complex. An appropriate interlayer connection plays here significant role ensuring proper transmission of distortions generated by wheels of vehicles to lower layers and preventing water penetration between the layers. In case of damaged pavements where lack...
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Influence of water and mineral oil on the leaks in satellite motor commutation unit clearances
PublicationThe article describes the flow rates of mineral oil and water flowing, as working media, through the commutation unit of a hydraulic satellite motor. It is demonstrated that geometrical dimensions of commutation unit clearances change as a function of the machine shaft rotation angle. Methods for measuring the rate of this flow and the pressure in the working chamber are presented. The results of pressure measurements in the working...
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Author Correction: Risk factors for serious morbidity, prolonged length of stay and hospital readmission after laparoscopic appendectomy - results from Pol-LA (Polish Laparoscopic Appendectomy) multicenter large cohort study
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Zespół wypalenia zawodowego i zmęczenie w kontekście pracy zmianowej i stresu zawodowego wśród pielęgniarek chirurgicznych
PublicationTwo aspects of work-related consequences among surgery nurses are discussed: burnout syndrome and fatigue, having an impact on the quality of medical care and safety of patients. Siegrist's effort-reward imbalance model has been adopted as a concept of occupational stress. The organization of working time, i.e. the length of shifts and their rotation, was considered. Nurses on twelve-hour shifts worked much harder, were more tired...
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The database of normal RR-intervals of length up to 512 of 41 patients at rest hospitalized due to the episode of acute ischemic stroke
Open Research DataThis dataset contains the data that was a basis for the results discussed in the paper “Persistent homology as a new method of the assessment of heart rate variability” by Grzegorz Graff, Beata Graff, Paweł Pilarczyk, Grzegorz Jabłoński, Dariusz Gąsecki, Krzysztof Narkiewicz, Plos One (2021), DOI: 10.1371/journal.pone.0253851.
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The database of interpolated RR-intervals of original length 512 of 41 patients at rest hospitalized due to the episode of acute ischemic stroke
Open Research DataThis dataset contains the data that was a basis for the results discussed in the paper “Persistent homology as a new method of the assessment of heart rate variability” by Grzegorz Graff, Beata Graff, Paweł Pilarczyk, Grzegorz Jabłoński, Dariusz Gąsecki, Krzysztof Narkiewicz, Plos One (2021), DOI: 10.1371/journal.pone.0253851.
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Nonlinear free and forced vibrations of a dielectric elastomer-based microcantilever for atomic force microscopy
PublicationThe majority of atomic force microcode (AFM) probes work based on piezoelectric actuation. However, some undesirable phenomena such as creep and hysteresis may appear in the piezoelectric actuators that limit their applications. This paper proposes a novel AFM probe based on dielectric elastomer actuators (DEAs). The DE is modeled via the use of a hyperelastic Cosserat model. Size effects and geometric nonlinearity are included...
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Improving Savonius rotor performance by shaping its blade edges
PublicationThe article presents the results of the numerical analysis of the flow inside the Savonius rotor. Particular at-tention has been paid to the vicinity of the blade gap in order to recognise the mechanisms controlling the flow in this area. The conclusions resulting from the analysis made the basis for an attempt to improve Savonius turbine performance via shaping rotor blade edges. The paper presents selected characteristic flow...
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Laminaty FRP w budownictwie - charakterystyka materiału i aspekty projektowania
PublicationW artykule przedstawiono charakterystykę laminatów polimerowych wzmacnianych włóknami. W pierwszej części zaprezentowano teoretyczne modele materiałowe, podstawowe zależności naprężenie-odkształcenie włókien, matrycy oraz laminatu powstałego przez połączenie obydwu składników. Na tej podstawie sformułowano zalecenia dotyczące praktycznego wykorzystania laminatu w kontekście jego wytężenia w projektowaniu elementów konstrukcyjnych....
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The database of indices computed from RR-intervals of length 512 of 41 patients at rest hospitalized due to the episode of acute ischemic stroke
Open Research DataThis dataset contains the data that was a basis for the results discussed in the paper “Persistent homology as a new method of the assessment of heart rate variability” by Grzegorz Graff, Beata Graff, Paweł Pilarczyk, Grzegorz Jabłoński, Dariusz Gąsecki, Krzysztof Narkiewicz, Plos One (2021), DOI: 10.1371/journal.pone.0253851.
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On time-dependent nonlinear dynamic response of micro-elastic solids
PublicationA new approach to the mechanical response of micro-mechanic problems is presented using the modified couple stress theory. This model captured micro-turns due to micro-particles' rotations which could be essential for microstructural materials and/or at small scales. In a micro media based on the small rotations, sub-particles can also turn except the whole domain rotation. However, this framework is competent for a static medium....
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TEM, EDS and optical microscope images of pristine and silica-coated bismuth oxide (Bi2O3) and gadolinium oxide (Gd2O3) structures.
Open Research DataData consists of raw TEM/EDS and optical microscope images of pristine and silica-coated bismuth oxide (Bi2O3) and gadolinium oxide (Gd2O3) structures. Additional TEM images and optical microscope images of silica shells were included.
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Dynamic tests of composite footbridge segment – experimental and numerical studies
PublicationExperimental dynamic tests and numerical simulations of a 3 meters long segment of a footbridge made of polymer composites are presented in the paper. The span-length is reduced, however dimensions of cross-section are the same as the target footbridge. The segment structure is made of sandwich panels, which consist of fibre reinforced polymer (GFRP) laminates (skins) and a PET foam (core). The first part of the paper contains...
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Environmental aspects of shale gas recovery in Baltic Basin
PublicationFactors limiting shale gas exploration and exploitation in Pomorskie Voivodeship are presented. In particular, ground and surface water availability and land/community impact is discussed. Production from unconventional reservoirs requires proper well completion through hydraulic fracturing, hence voluminous streams of water are needed – in total 8000 to 20000 m3 per 1000 m of borehole length. 17 major groundwater basins were characterized....
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Local buckling of composite channel columns
PublicationThe investigation concerns local buckling of compressed flanges of axially compressed composite channel columns. Cooperation of the member flange and web is taken into account here. The buckling mode of the member flange is defined by rotation angle a flange about the line of its connection with the web. The channel column under investigation is made of unidirectional fibre-reinforced laminate. Two approaches to member orthotropic...
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Natural convective heat transfer from isothermal cuboids
PublicationThe paper presents results of theoretical and experimental investigations of the convective heat transfer from isothermal cuboid. The analytical solution was performed taking into account complete boundary layer length and the manner of its propagation around isothermal cuboid. It arises at horizontal bottom surface and grows on vertical lateral surface of the block. After changing its direction, the boundary layer occurs above...
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Nonlinear Free and Forced Vibrations of a Hyperelastic Micro/Nanobeam Considering Strain Stiffening Effect
PublicationIn recent years, the static and dynamic response of micro/nanobeams made of hyperelasticity materials received great attention. In the majority of studies in this area, the strain-stiffing effect that plays a major role in many hyperelastic materials has not been investigated deeply. Moreover, the influence of the size effect and large rotation for such a beam that is important for the large deformation was not addressed. This...
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Wybrane aspekty formułowania, implementacji oraz aplikacji 6-parametrowej nieliniowej teorii powłok
Publicationpracy przedstawiono rekapitulację stanu wiedzy w zakresie nieliniowej 6-parametrowej teorii powłok, w której szóstym parametrem jest obrót prostopadły do powierzchni odniesienia powłoki tzw. obrót owinięcia (ang. drilling rotation). Zasadnicze fundamenty teorii 6-parametrowej wynikają z pracy między innymi osób: pierwotnego podejścia E. Reissnera podjętego dalej przez takich badaczy jak A. Libai, J.G. Simmonds, J. Makowski, W....
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Numerical Modelling of Shear Localization in Granular Bodies using MPM and Non-local Hypoplasticity
PublicationThe paper deals with modelling of shear localization in granular bodies by means of an enhanced hypoplastic constitutive model and material point method (MPM). The calculations were carried out for plane strain compression of non-cohesive sand. In order to properly capture the width and inclination of shear zones, the constitutive model was enriched by a characteristic length of micro-structure by means of a non-local theory....
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Sounding of Layered Marine Bottom - Model Investigations
PublicationThe necessary actions connected with interpretations of examining of physical properties of sea bottom structure is developing of proper procedure of modeling of the layered structure. The implementation of the acoustic waves for the determination of seabed stratification requires a precise diagnosis of the topic from both the theoretical and practical side. Little differences between the parameters of sediments, as well as irregular...
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Three series of measurement of spring force in relation to deflection of disc springs assembled in X configuration.
Open Research DataAttached data consist of three series of conducted measurement of disc springs package characteristic. The characteristic describes relation between spring force and deflection of the package. First column of each serie present axial deflection of the package, while second columns contain recorded spring force. Object of research contained six disc...
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EMISJA AKUSTYCZNA JAKO SYGNAŁ DIAGNOSTYCZNY ODWZOROWUJĄCY ZMĘCZENIOWE ZUŻYCIE WARSTW ŚLIZGOWYCH PANWI ŁOŻYSK GŁÓWNYCH I KORBOWYCH SILNIKÓW O ZAPŁONIE SAMOCZYNNYM
PublicationW artykule przedstawiono wyniki badań laboratoryjnych, z których wynika, że emisja akustyczna (EA) może być uznana za sygnał diagnostyczny, przydatny do identyfikacji stanu technicznego łożysk głównych i korbowych okrętowych silników o zapłonie samoczynnym. Wykazano w nim bowiem, że parametry emisji akustycznej takie jak: czas rejestracji, energia sygnału, amplituda sygnału, ilość przekroczeń poziomu dyskryminacji, czas narastania,...
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Installation of CMC columns in overconsolidated clays
PublicationDuring rigid inclusions execution in the subsoil some monitoring data are registered by a drilling rig for quality control. The use of these data can improve the design procedure of soil improvement as they can provide some information about the position of bearing strata and the energy necessary to install the column in the ground. In this paper the parameters registered in a drilling machine are described, the installation...
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Results of experimental research of hydraulic satellite motor
Open Research DataThe study of the flow rate in the motor and the torque on the motor shaft at low constant speed were carried out.The file contains measurement data of the torque on the motor shaft and the flow rate in the motor as a function of the angle of shaft rotation at various constant pressure drops in the motor.
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Tuning transfer function of fiber-optic Fabry-Pérot interferometer via introduction of birefringence in the cavity
PublicationThe study investigates the impact of birefringence exhibited by the cavity material of a fiber-optic Fabry-Pérot interferometer on its transfer function. The theoretical approach to analyze the effect of birefringence in the cavity of a plane Fabry-Pérot interferometer is described. The case of high- and low-finesse interferometer is investigated. It is shown that introduction of a birefringent medium of optimized parameters can...
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Anti-plane waves in an elastic thin strip with surface energy
PublicationWe consider anti-plane motions of an elastic plate taking into account surface energy within the linear Gurtin–Murdoch surface elasticity. Two boundary-value problems are considered that describe complete shear dynamics of a plate with free faces or with free and clamped faces, respectively. These problems correspond to anti-plane dynamics of an elastic film perfectly or non-perfectly attached to a rigid substrate. Detailed analysis...
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Offshore project management based on jack-up rig conversion
PublicationChapter presents aspects of Offshore project management during conversion drilling rig to accommodation rig in Batam Indonesia
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Keep It Flexible: Driving Macromolecular Rotary Motions in Atomistic Simulations with GROMACS
PublicationWe describe a versatile method to enforce the rotation of subsets of atoms, e.g., a protein subunit, in molecular dynamics (MD) simulations. In particular, we introduce a “flexible axis” technique that allows realistic flexible adaptions of both the rotary subunit as well as the local rotation axis during the simulation. A variety of useful rotation potentials were implemented for the GROMACS 4.5 MD package. Application to the...
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Model tests of cast-in-place piles formed by using different types of auger
PublicationModel tests are still a popular research tool used to observe and determine the mechanisms of pile-soil interaction. Due to the significant scale effect, the results of model tests performed in the 1g system can only be analysed from the qualitative side. This article describes and presents the results of 1g pile model tests carried out for comparative purposes. There were tested the effectiveness and efficiency of various types...
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IMPLANT USED IN HERNIA REPAIR UNDER PHYSIOLOGICAL MOVEMENTS OF HUMAN ABDOMEN
PublicationThe study deals with the mechanical behaviour of implant used in repair of abdominal hernia. The influence of orientation of the orthotropic implants in different areas of abdominal wall is studied.
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Robert Jankowski prof. dr hab. inż.
PeopleHe was born on December 26, 1968 in Gdynia. A graduate of the High School at the Consulate of Poland in Benghazi, Libya (1987), a student at the Gdańsk University of Technology (MSc studies, 1987-1991 and 1992-1993), University of Sheffield, England (BSc studies, 1991-1992), University of Roskilde, Denmark (MSc course, 1993) and University of Tokyo, Japan (PhD studies, 1994-1997). From the beginning of his professional career associated...
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Numerical Model of Femur Part
PublicationThe aim of the study is to create a new more accurate method of femur part modelling by using the finite element method. According to this new method, a femur part is treated as a complex structure composed of trabecular bone (internal part) and cortical bone (external part). The internal part is modelled as a scaffold, thus the external part is modelled as a coat (i.e. covering). Applying the programme ABAQUS, there were created...
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Abdalraheem Ijjeh Ph.D. Eng.
PeopleThe primary research areas of interest are artificial intelligence (AI), machine learning, deep learning, and computer vision, as well as modeling physical phenomena (i.e., guided waves in composite laminates). The research interests described above are utilized for SHM and NDE applications, namely damage detection and localization in composite materials.
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A compact seven-section rat-race hybrid coupler incorporating pbg cells
PublicationA conventional rat-race coupler has been doubly miniaturized: (i) characteristic impedances and electrical lengths of microstrip sections have been adequately modified as the first step of size reduction and (ii) T-shaped PBG cells have been implemented to diminish strip section length as the second step of circuit rat-race couplerminiaturization. The experimental results show good agreement with theoretical characteristics. Furthermore,...
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Experimental Investigations on the Influence of Coil Arrangement on Melting/Solidification Processes
PublicationThe latent heat thermal energy storage units are very popular because of their high energy density and almost close to constant temperature during the charging/discharging. In the present study has been proposed new shell-and-coil geometry with a shifted coil position to enhance the performance of phase change thermal magazine. The experimental investigations have been performed both for the melting and solidification process of...
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Numerical investigation on dynamic performance of a multi-storey steel structure model and comparison with experimental results
PublicationShaking table testing is the most commonly adopted method to simulate earthquake forces. This approach allows us to analyze the dynamic performance and provides a valuable insight into the dynamics of building structures, which helps to improve their future safety and reliability. The present study aims to conduct a numerical evaluation of dynamic response of a multi-storey steel structure model, which was previously examined during...
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Numerical Investigation on Dynamic Performance of a Multi-storey Steel Structure Model and Comparison with Experimental Results
PublicationShaking table testing is the most commonly adopted method to simulate earthquake forces. This approach allows us to analyze the dynamic performance and provides a valuable insight into the dynamics of building structures, which helps to improve their future safety and reliability. The present study aims to conduct a numerical evaluation of dynamic response of a multi-storey steel structure model, which was previously examined during...
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COMPOSITE MATERIAL SELECTION FOR A PATIENT TRANSFER ASSIST DEVICE
PublicationLaminates - layered composites containing at least two elements (matrix and reinforcement) widely used in industry have also found their usage in medicine. Their main feature is the ability to modify the material in order to obtain the required properties. Depending on the needs, we can modify reinforcement, type of resin or the method of bonding substrates. Commonly used fibers are: carbon fiber, glass and aramid fibers; resins...
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Anna Rzeczycka dr hab.
PeopleAnna Rzeczycka is the deputy head of the Department of Finance at the Faculty of Economics and Management of the Gdańsk University of Technology. Publications are situated in the field of social sciences in the discipline of economics and finance. They include books, monographs, articles, publications and scientific editions of monographs and scientific journals. In terms of numbers, it includes the following items: 12 monographs...
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Design of weighted PID controllers for control of the Stewart-Gough platform
PublicationStewart-Gough platform (SGP) is a popular parallel type manipulator that involves a 6 degrees of freedom (DOF) motion. In this paper, the process of mathematical modelling of SGP is presented. Two selected control algorithms that use PID controllers and weighted PID controllers are designed. Both control systems using these algorithms are implemented in MATLAB environment as well as on the actual SGP. Parameters of the controllers...
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SIMULATIONS OF FRACTURE IN CONCRETE BEAMS UNDER BENDING USING A CONTINUUM AND DISCRETE APPROACH
PublicationThe paper describes two-dimensional meso-scale results of fracture in notched concrete beams under bending. Concrete was modelled as a random heterogeneous 4-phase material composed of aggregate particles, cement matrix, interfacial transitional zones and air voids. Within continuum mechanics, the simulations were carried out with the finite element method based on a isotropic damage constitutive model enhanced by a characteristic...
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Laboratory research on the influence of swelling clay on the quality of borehole cementing and evaluation of clay-cutting wellbore tool prototype
PublicationSwelling clay phenomenon is frequently observed during oil and gas drilling operations and has a significant impact on the quality of cementing procedure. Certain types of clayey minerals increase their volume in contact with water-based drilling fluids. After drilling is completed, borehole remains unsupported and filled with waterbased drilling fluids for several hours, before a casing string is inserted and secured with cement....
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Non-destructive inspection of ground anchors using guided wave propagation
PublicationThis paper deals with numerical and experimental investigations of specific problems of guided wave propagation in ground anchors. The research focuses on recognizing the phenomenon of the energy transfer between anchor components. Particular attention is paid to characteristic features of guided waves propagating in free and embedded parts of the tendon, at the interface between the tendon and the surrounding anchor body as well...
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X-ray Photoelectron Spectroscopy (XPS) results of bulk boron and borophene after the ball-milling process
Open Research DataThese data contain X-ray Photoelectron Spectroscopy (XPS) results of boron and borophene nanoflakes induced during ball milling at rotation speed of 450 rpm, 6 h and mass loading of 1g.
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Numerical simulation of laminate composite specimens failure
PublicationThis work presents some numerical results concerning simulation of failure of laminate composite specimens. In the article two tests to determine ultimate strength in an orthotropic layer, are considered: tension (TT1) and compression (TC1) test. The outcome is compared with experimental data provided by [9,10].
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Variations of Ship’s Deck Elevation Due to Stochastic Process of Containers Loading
PublicationThe stochastic process of container loading is described in the paper with special emphasis to ship motion when she is lying at a quay. The 3 DOF system was applied to describe rolling, pitching and heaving of a vessel which may cause a significant variations of momentary deck elevation. The realistic range of such variations are assessed for a variety of cargo locations on-board and a phase shift between two independent gantries...
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X-ray diffraction (XRD) of bulk boron and borophene flakes after the ball-milling process at different operating parameters
Open Research DataThese data include X-ray diffraction patterns of bulk boron and borophene obtained during ball milling at different rotation speeds, time and mass loadings. The data were collected to investigate the crystal structure of the studied materials.