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Objective of this study is to examine the impact of medication adherence on the timing of non-cardiovascular serious events (NCDS) onset in patients with acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI). Methods: This prospective study was conducted at a single center and involved 220 ACS patients who underwent sequential PCI with stenting. The Morisky Green Levine Medication Adherence Scale was employed to assess adherence to dual antiplatelet therapy (DAPT) and its impact on NCDS occurrence. Early in their hospitalization, all patients received education at the Coronary Heart Disease School. The survival rates of patients in both the main group and a control group (n=355) were subsequently evaluated. Results: The study findings indicated an inverse relationship between stent thrombosis development (Rho=− 0.334; p=0.001) and the timing of recurrent myocardial ischemia. There was also an inverse correlation between patient adherence and stent thrombosis development (Rho=− 0.275; p=0.009). Non-adherent individuals had a 16.8 times higher likelihood of experiencing stent thrombosis compared to compliant patients (p< 0.001). Following participation in the CHD School program, treatment adherence increased from 56.5% to 88.2%. Education for ACS patients post-stenting was significantly associated with all-cause mortality within the first 6 months (p=0.040). Conclusion: Secondary preventive measures, including education, impact the success of endovascular interventions in both the early hospital phase and the long term. Patient education can serve as a supplementary intervention to enhance DAPT adherence, thus diminishing the risk of recurrent cardiovascular events and mortality post endovascular intervention. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVES: Purpose of the study is the assessment of the effectiveness of renal denervation with different types of catheters, as well as its long-term effects, in the patients with resistant hypertension. MATERIALS AND METHODS: This single-center prospective study included 81 patients who underwent a renal denervation procedure using 2 types of catheters: monopolar and helical (Medtronic Inc., Minneapolis, Minnesota, the USA) between 2015 and 2018. Baseline demographics, clinical, functional and laboratory characteristics of the patients were assessed. A comparative analysis of the dynamics of office systolic and diastolic blood pressure during 5 years of follow-up was carried out. The Kaplan-Meier method was used to study the survival of the patients with resistant hypertension after renal denervation. RESULTS: A total of 81 patients with a mean age of 57.79±9.87 years, of whom 37.04 % were men, were included in the 2-stage study (first stage using monopolar catheters and second stage using spiral catheters). At the time of inclusion, study participants were receiving an average of 4.5±1.4 antihypertensive medications. In 36 (or 44.4 %), the procedure was performed using a monopolar catheter; in 45 (or 55.6 %), a spiral catheter was used. There were no statistically significant differences between the two groups of the patients. The analysis established statistically significant changes in the dynamics of office SBP and DBP (p < 0.001) assessed 1, 2, 3, 4, and 5 years after the renal denervation procedure. The analysis demonstrated a stability in the reduction of office SBP and DBP during the 5-year follow-up. The results of the study showed that the median survival time was 1061 days from the beginning of follow-up (95% CI: 728.03 to 1 393.97 days); the median survival time in the monopolar catheter group was 777 days (95% CI: 692.314 to 861.686) and in the spiral catheter group 1 294 days (95% CI: 713.079 to 1 874.921). FINDINGS: Our results demonstrated the efficiency and safety of renal denervation in both short-term and long-term follow-up using monopolar and spiral catheters in the treatment of uncontrolled hypertension with combined antihypertensive therapy. The most significant is the demonstrated stability of the effect after the procedure. In addition, the survival rate of the patients with resistant hypertension after the intervention has been carried out (Tab. 2, Fig. 3, Ref. 22). Text in PDF www.elis.sk [ABSTRACT FROM AUTHOR]

We consider an approach to mathematical modeling of photodegradation of polymer nanocomposites with photoactive additives using the Monte Carlo methods. We principally pay attention to the strength decrease of these materials under solar light action. We propose a new term, "photocatalytic fatigue", which we apply to the particular case when the mechanical strength decreases only owing to the presence of photocatalytically active components in polymeric nanocomposite material. The propriety of the term is based on a relative similarity of photostimulated mechanical destructive processes in nanocomposites with photoactive additives and mechanical destructive processes typical for metal high-cycle fatigue. Formation of the stress concentrations is one of the major causes of fatigue cracks generation in metals. Photocatalytic active nanoparticles of semiconductors initiate a generation of the stress concentrations under sunlight irradiation. The proposed mathematical model is a Wöhler curve analog for the metal high-cycle fatigue. We assume that equations for high-cycle fatigue curves of samples with stress concentrations could be used in mathematical modeling of polymer nanocomposites photodegradation. In this way, we replace the number of loading cycles with the exposition time in the equations. In the case of polypropylene and polyester samples with photoactive titanium dioxide, the experimental parameters of phenomenological equations for "photocatalytic fatigue" are calculated using one of the Monte Carlo methods based on the random search algorithm. The calculating scheme includes a solution of the extreme task of finding of the minimum of nonnegative transcendent multivariable function, which is a relative average quadratic deviation of calculated values of polymeric nanocomposite stress in comparison with corresponding experimental values. The applicability of the "photocatalytic fatigue" model for polymer nanocomposites with photoactive nanoparticles is confirmed by the example of polypropylene and polyester samples. The approximation error of the experimental strength values for them did not exceed 2%. [ABSTRACT FROM AUTHOR]

The precipitation mechanism of the Q phase in Al-Mg-Si-Cu alloys has long been the subject of ambiguity and debate since its metastable phase (Q′) has the same crystal structure and similar lattice parameters as its equilibrium counterparts. In the present work, the evolution of the Q′ (Q) phase during aging is studied by combination of quantitative atomic-resolution scanning transmission electron microscopy and atom probe tomography. It was found that the transformation from the Q′ to the Q phase involves changes of the occupancy of Al atoms in atomic columns of the Q′ (Q) phase. The Al atoms incorporated in the Cu, Si and Mg columns are gradually released into the Al matrix, while mixing between Cu and Si atoms occurs in the Si columns. This transformation process is mainly attributed to the low lattice misfit of the equilibrium Q phase. Besides, the formation of various compositions of the Q phase is due to the different occupancy in the atomic columns of the Q phase. The occupancy changes in the columns of the Q phase are kinetically controlled and are strongly influenced by the alloy composition and aging temperature. [ABSTRACT FROM AUTHOR]

Anatase–mordenite nanocomposite was synthesized in situ and characterized by X-ray diffraction analysis, Brunauer–Emmett–Teller measurements, infrared (IR) spectroscopy, electron diffraction measurements, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and scanning and transmission electron microscopy. It was found that X-ray-amorphous anatase located in the zeolite micropores resulted in a decrease in the specific surface of anatase–mordenite compared to the initial mordenite. Anatase-containing nanoparticles in anatase–mordenite showed round shape and formed nano-associates and conglomerates. The water content in the zeolite cavities in anatase–mordenite was lower compared to mordenite. Anatase–mordenite nanocomposite exhibited higher photocatalytic activity in the model decomposition reaction of methyl orange under ultraviolet (UV) radiation and higher adsorption capacity for extraction of P(V) and As(V) ions from aqueous environment in the dark compared to the initial mordenite or anatase due to an increase in the content of active OH-groups on the nanocomposite surface compared to mordenite and an increase in the specific surface compared to anatase. [ABSTRACT FROM AUTHOR]

The interaction between dislocations and nano-precipitates during deformation directly influences hardening response of precipitation-strengthening metals such as Al-Mg-Si alloys. However, how coherent and semi-coherent nano-precipitates accommodate external deformation applied to an Al alloy remains to be elucidated. In-situ tensile experiments in a transmission electron microscope (TEM) were conducted to study the dynamic process of dislocations cutting through coherent needle-like β″ precipitates with diameters of 3∼8 nm. Comprehensive investigations using in-situ, ex-situ TEM and atom probe tomography uncovered that β″ precipitates were firstly sheared into small fragments, and then the rotation of the fragments, via sliding along precipitate/matrix interfaces, destroyed their initially coherent interface with the Al matrix. In contrast, semi-coherent βʹ precipitates with sizes similar to β″ were more difficult to be fragmented and accumulation of dislocations at the interface increased interface misfit between βʹ and the Al matrix. Consequently, βʹ precipitates could basically maintain their needle-like shape after the tensile deformation. This research gains new insights into the interaction between nano-precipitates and dislocations. [Display omitted] [ABSTRACT FROM AUTHOR]

The rheological properties of amorphous olivine thin films deposited by pulsed laser deposition have been studied based on ambient temperature nanoindentation under constant strain-rate as well as relaxation conditions. The amorphous olivine films exhibit a viscoelastic-viscoplastic behavior with a significant rate dependency. The strain-rate sensitivity m is equal to ∼ 0.05 which is very high for silicates, indicating a complex out-of-equilibrium structure. The minimum apparent activation volume determined from nanoindentation experiments corresponds to Mg and Fe atomic metallic sites in the (Mg,Fe) 2 SiO 4 crystalline lattice. The ambient temperature creep behavior of the amorphous olivine films differs very much from the one of single crystal olivine. This behavior directly connects to the recent demonstration of the activation of grain boundary sliding in polycrystalline olivine following grain boundary amorphization under high-stress. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper aims to consider approximation-estimation tests for decision-making by machine-learning methods, and integral-estimation tests are defined, which is a generalization for the continuous case. Approximation-estimation tests are measurable sampling functions (statistics) that estimate the approximation error of monotonically increasing number sequences in different classes of functions. These tests make it possible to determine the Markov moments of a qualitative change in the increase in such sequences, from linear to nonlinear type. If these sequences are trajectories of discrete quasi-deterministic random processes, then moments of change in the nature of their growth and qualitative change in the process match up. For example, in cluster analysis, approximation-estimation tests are a formal generalization of the "elbow method" heuristic. In solid mechanics, they can be used to determine the proportionality limit for the stress strain curve (boundaries of application of Hooke's law). In molecular biology methods, approximation-estimation tests make it possible to determine the beginning of the exponential phase and the transition to the plateau phase for the curves of fluorescence accumulation of the real-time polymerase chain reaction, etc. [ABSTRACT FROM AUTHOR]

Microplasmas can be used for a wide range of technological applications and to improve the understanding of fundamental physics. Scanning electron microscopy, on the other hand, provides insights into the sample morphology and chemistry of materials from the mm‐ down to the nm‐scale. Combining both would provide direct insight into plasma‐sample interactions in real‐time and at high spatial resolution. Up till now, very few attempts in this direction have been made, and significant challenges remain. This work presents a stable direct current glow discharge microplasma setup built inside a scanning electron microscope. The experimental setup is capable of real‐time in situ imaging of the sample evolution during plasma operation and it demonstrates localized sputtering and sample oxidation. Further, the experimental parameters such as varying gas mixtures, electrode polarity, and field strength are explored and experimental V–I curves under various conditions are provided. These results demonstrate the capabilities of this setup in potential investigations of plasma physics, plasma‐surface interactions, and materials science and its practical applications. The presented setup shows the potential to have several technological applications, for example, to locally modify the sample surface (e.g., local oxidation and ion implantation for nanotechnology applications) on the µm‐scale. [ABSTRACT FROM AUTHOR]

Recent observations made by the authors revealed the activation of stress induced amorphization and sliding at grain boundary in olivine [1] , a mechanism which is expected to play a pivotal role in the viscosity drop at the lithosphere-asthenosphere boundary and the brittle-ductile transition in the lithospheric mantle. However, there is a lack of information in the literature regarding the intrinsic mechanical properties and the elementary deformation mechanisms of this material, especially at time scales relevant for geodynamics. In the present work, amorphous olivine films were obtained by pulsed laser deposition (PLD). The mechanical response including the rate dependent behavior are investigated using a tension-on-chip (TOC) method developed at UCLouvain allowing to perform creep/relaxation tests on thin films at extremely low strain rates. In the present work, strain rate down to 10−12 s−1 was reached which is unique. High strain rate sensitivity of 0.054 is observed together with the activation of relaxation at the very early stage of deformation. Furthermore, digital image correlation (DIC), used for the first time on films deformed by TOC, reveals local strain heterogeneities. The relationship between such heterogeneities, the high strain rate sensitivity and the effect of the electron beam in the scanning electron microscope is discussed and compared to the literature. [Display omitted] [ABSTRACT FROM AUTHOR]

Hybrid pixel direct electron detectors are gaining popularity in electron microscopy due to their excellent properties. Some commercial cameras based on this technology are relatively affordable which makes them attractive tools for experimentation especially in combination with an SEM setup. To support this, a detector characterization (Modulation Transfer Function, Detective Quantum Efficiency) of an Advacam Minipix and Advacam Advapix detector in the 15–30 keV range was made. In the current work we present images of Point Spread Function, plots of MTF/DQE curves and values of DQE(0) for these detectors. At low beam currents, the silicon detector layer behaviour should be dominant, which could make these findings transferable to any other available detector based on either Medipix2, Timepix or Timepix3 provided the same detector layer is used. • Timepix DED is excellent at 15–30 keV, PSF-MTF are near ideal, max DQE(0) is 60% • PSF-MTF degrade with e-beam energy increase, PSF-MTF improve with DED threshold rise • DQE values show a significant DQE reduction at increased detector threshold value • At 15keV beam energy both cameras show low DQE due to Al layer on top of sensor [ABSTRACT FROM AUTHOR]

Substrates pretreatment in suspensions of a detonation nanodiamond is widely used for nucleation of diamond growth by chemical vapor deposition (CVD). We found that iron inclusions in the nanodiamond provide catalytical growth of carbon nanotubes during CVD in a hot filament reactor (HF CVD). Carbon nanotubes grow in the area between two adjacent Si wafers. The diameters of such obtained nanotubes were in the range of 10–100 nm and the length of the tubes reaches about 10 µm. The proposed HF CVD method has convincing potential for the fabrication of carbon nanotube coatings on a large surface area. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (gCN) is a promising n-type semiconductor widely investigated for photo-assisted water splitting, but less studied for the (photo)electrochemical degradation of aqueous organic pollutants. In these fields, attractive perspectives for advancements are offered by a proper engineering of the material properties, e.g., by depositing gCN onto conductive and porous scaffolds, tailoring its nanoscale morphology, and functionalizing it with suitable cocatalysts. The present study reports on a simple and easily controllable synthesis of gCN flakes on Ni foam substrates by electrophoretic deposition (EPD), and on their eventual decoration with Co-based cocatalysts [CoO, CoFe2O4, cobalt phosphate (CoPi)] via radio frequency (RF)-sputtering or electrodeposition. After examining the influence of processing conditions on the material characteristics, the developed systems are comparatively investigated as (photo)anodes for water splitting and photoelectrocatalysts for the degradation of a recalcitrant water pollutant [potassium hydrogen phthalate (KHP)]. The obtained results highlight that while gCN decoration with Co-based cocatalysts boosts water splitting performances, bare gCN as such is more efficient in KHP abatement, due to the occurrence of a different reaction mechanism. The related insights, provided by a multi-technique characterization, may provide valuable guidelines for the implementation of active nanomaterials in environmental remediation and sustainable solar-to-chemical energy conversion. [ABSTRACT FROM AUTHOR]

The Coulomb blockade effect is commonly used in solid state electronics for the control of electron flow at the single-particle level. Potentially, it allows the creation of single-electron point sources demanded for prospective electron microscopy instruments and other vacuum electronics devices. Here we realize this potential via creation of a stable point electron source composed of a carbon nanowire electrically coupled to a diamond nanotip by a tunnel junction. Using energy spectroscopy analysis, we characterize the electrons liberated from the nanometer scale carbon heterostructures in time and energy domains. Our experimental results demonstrate perfect agreement with theory prediction of Coulomb oscillations of the Fermi level in the nanowire and allow to determine the mechanisms of their suppression. Persistence of the oscillations at room temperature, high intensity field emission with currents up to 1 μA, and other characteristics of our emitters are very promising for practical realization of coherent single-electron guns. Image 1 [ABSTRACT FROM AUTHOR]

Following an extensive investigation of various monolayer transition metal dichalcogenides (MX2), research interest has expanded to include multilayer systems. In bilayer MX2, the stacking order strongly impacts the local band structure as it dictates the local confinement and symmetry. Determination of stacking order in multilayer MX2 domains usually relies on prior knowledge of in-plane orientations of constituent layers. This is only feasible in case of growth resulting in well-defined triangular domains and not useful in-case of closed layers with hexagonal or irregularly shaped islands. Stacking order can be discerned in the reciprocal space by measuring changes in diffraction peak intensities. Advances in detector technology allow fast acquisition of high-quality four-dimensional datasets which can later be processed to extract useful information such as thickness, orientation, twist and strain. Here, we use 4D scanning transmission electron microscopy combined with multislice diffraction simulations to unravel stacking order in epitaxially grown bilayer MoS2. Machine learning based data segmentation is employed to obtain useful statistics on grain orientation of monolayer and stacking in bilayer MoS2. [ABSTRACT FROM AUTHOR]

It is generally believed that β″ precipitates, rather than β′ precipitates, are the major strengthening precipitates in aged Al–Mg–Si alloys. The reason for this difference is not well understood. To clarify this, two samples of the same Al–Mg–Si alloy but with different aging states were prepared. The under-aged sample only contains nano-precipitates of the β″ type, while the peak-aged one contains nearly equal volumes of β″ and β′ precipitates. We have, for the first time, separated the strengthening effect of the contribution from βʺ and βʹ precipitates, respectively, by an indirect approach based on high-precision measurements of volume fractions, number densities, sizes, proportions of the precipitates, their lattice strains, the composition and grain size of the matrix. The β′ precipitates, which take 45.6% of the total precipitate volume in the peak-aged sample, contribute to the entire precipitation strengthening by only 31.6%. The main reason why they are less useful compared to β″ precipitates has been found to be associated with their smaller lattice strains relative to the matrix, which is 0.99% versus 2.10% (for β″). [ABSTRACT FROM AUTHOR]

To transform a monocrystalline diamond into monocrystalline graphite, the exposure of an ultrafast laser to a (111) diamond face was investigated for the first time. The single pulse of the third harmonic of a Ti:sapphire laser (100 fs, 266 nm) was used to produce graphitized inclusions embedded in a (111) diamond substrate. Three different regimes of (111) diamond graphitization are discussed in this paper. Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy were used to investigate the graphitized material, which was found to resemble highly oriented graphite at certain laser fluencies. The proposed approach to the problem of perfect local diamond graphitization is an important step toward creating all-carbon composite systems consisting of conductive and dielectric phases. [ABSTRACT FROM AUTHOR]

[Display omitted] • Graphitic carbon nitride (g-C 3 N 4) is deposited by decantation and functionalized with CoO and CoFe 2 O 4 co-catalysts. • Pure g-C 3 N 4 -based composite systems, featuring an intimate contact with CoO and CoFe 2 O 4 nanoparticles, are obtained. • The construction of p - n g-C 3 N 4 -CoO and Z -scheme g-C 3 N 4 -CoFe 2 O 4 junctions is effective in enhancing oxygen evolution performances. • The present results pave the way to the implementation of stable, cheap and active anodes for solar water splitting. The ever-increasing energy demand from the world population has made the intensive use of fossil fuels an overarching threat to global environment and human health. An appealing alternative is offered by sunlight-assisted photoelectrochemical water splitting to yield carbon-free hydrogen fuel, but kinetic limitations associated to the oxygen evolution reaction (OER) render the development of cost-effective, eco-friendly and stable electrocatalysts an imperative issue. In the present work, OER catalysts based on graphitic carbon nitride (g-C 3 N 4) were deposited on conducting glass substrates by a simple decantation procedure, followed by functionalization with low amounts of nanostructured CoO and CoFe 2 O 4 by radio frequency (RF)-sputtering, and final annealing under inert atmosphere. A combination of advanced characterization tools was used to investigate the interplay between material features and electrochemical performances. The obtained results highlighted the formation of a p - n junction for the g-C 3 N 4 -CoO system, whereas a Z -scheme junction accounted for the remarkable performance enhancement yielded by g-C 3 N 4 -CoFe 2 O 4. The intimate contact between the system components also afforded an improved electrocatalyst stability in comparison to various bare and functionalized g-C 3 N 4 -based systems. These findings emphasize the importance of tailoring g-C 3 N 4 chemico-physical properties through the dispersion of complementary catalysts to fully exploit its applicative potential. [ABSTRACT FROM AUTHOR]

A new method for synthesis of 2D nanocrystals in water was proposed. The use of perfluorothiophenolate ions as surfactant allowed us to produce 2D single-crystal nanosheets of CaS at pH=9 and flat nanocrystals of PbS at pH=9 at room temperature. Mesocrystalline nanobelts of CdS and mesocrystals of PbS were obtained at pH=3–5 and pH=10–12, respectively. Morphology, structure and chemical composition of nanoparticles were characterized by high-resolution transmission electron microscopy, electron diffraction and energy dispersive X-ray spectroscopy. A mechanism of nanoparticles formation was discussed. [ABSTRACT FROM AUTHOR]

The formation of active component of Fe–Mo and Co–Mo catalysts for carbon nanotube growth with variable Mo content is studied with in situ XRD, XPS, and STEM&EDX. The activation of bimetallic Fe–Mo catalysts under the growth conditions leads to the formation of Fe–Mo alloy particles in contrast to Co‐containing catalysts in which active alloy incorporates only a small portion of Mo (<2–3 at.%). The stable carbide formation for these systems is not detected. The effect of Mo content in Fe–Mo and Co–Mo catalysts on the properties of MWCNTs is additionally investigated using the Raman spectroscopy in combination with measurements of the temperature dependence of conductivity. It is shown that MWCNT defectiveness depends on the active component composition for both Fe–Mo and Co–Mo catalysts. The current carrier concentration for the MWCNTs grown on Fe–Mo catalysts slightly increases with the Mo content. The opposite effect is observed for the tubes grown on Co–Mo catalysts, showing a decrease in the current carrier concentration with the increase of Mo concentration. [ABSTRACT FROM AUTHOR]

In this article, we present a comparative study of field emission (FE) properties of the films of pristine, annealed and CuCl-filled single-walled carbon nanotubes (SWCNTs). The current-voltage dependencies and emission site distributions were measured in the diode configuration with a flat phosphor-coated anode. A significant increase of the threshold field was observed after annealing and doping of the films. It was explained by the selective oxidation of the small-diameter nanotubes confirmed by the Raman spectroscopy. The FE properties of annealed and filled SWCNTs were found to coincide with each other. At the same time, their Raman spectra differ significantly indicating the strong p-type doping induced by encapsulated CuCl. The obtained result reveals that the CuCl filling leads to significant changes in macroscopically averaged electronic properties but do not change the local work function at the apexes of emitting nanotubes, which is important for the further development of SWCNTs-based FE cathodes. [ABSTRACT FROM AUTHOR]

Diamond platelets of sub-micrometer size were obtained by chemical vapor deposition technique from CH 4 /H 2 gas mixture activated by a direct current discharge. Comprehensive characterization of the diamond platelets was performed with use of scanning and transmission electron microscopy. The diamond platelet crystallites were found to be in the deposited material in form of stacked or isolated hexagonal platelets in combination with polyhedron crystallites. Six-fold rotational symmetry and composition of stacked (111) atom planes in the diamond platelets was revealed from analysis of the electron diffraction patterns. The structure and possible growth mechanisms of the platelets in the case of direct current plasma-enhanced chemical vapor deposition are discussed. [ABSTRACT FROM AUTHOR]

Phase formation and transitions in platinum silicide films on polycrystalline Si in the process of Pt magnetron sputtering and heat treatments at different temperatures are studied using X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy and X-ray diffractometry. Phases of amorphous and polycrystalline Pt 3 Si and Pt 2 Si are shown to form during the room-temperature Pt deposition on poly-Si beneath the Pt layer. The relaxation of the interfacial film and partial transformation of Pt 3 Si into Pt 2 Si occurs as a result of the thermal treatment for 30 min in the temperature range from 125°C to 300°С. The Pt 3 Si and Pt 2 Si phases crystallize to PtSi due to annealing at the temperatures from 320°C to 480°С for the same time period. Image 1 • Interface domain in magnetron sputtered and annealed Pt/poly-Si film is studied. • Pt 3 Si and Pt 2 Si phases form at room temperature during Pt deposition on poly-Si. • Interfacial film relaxation turns Pt 3 Si to Pt 2 Si due to annealing at 100 < T < 200 °C. • Pt 3 Si and Pt 2 Si transit to PtSi due to annealing at temperatures from 320 to 480 °C. • Pt 3 Si phase is detected up to the annealing temperature of 350 °C. [ABSTRACT FROM AUTHOR]

A detailed microstructural examination endeavoring to understand the interfacial phenomena yielding to cohesion in solid-state assembling processes was performed. This study focuses on the transition zone of a dissimilar titanium alloy joint obtained by Linear Friction Welding (LFW) the β-metastable Ti17 to the near-α Ti6242. The transition zone delimitating both alloys is characterized by a sharp microstructure change from acicular HCP (Hexagonal Close-Packed) α′ martensitic laths in the Ti6242 to equiaxed BCC β (Body-Centered Cubic) subgrains in the Ti17; these α′ plates were shown to precipitate within prior-β subgrains remarkably more rotated than the ones formed in the Ti17. Both α′ and β microstructures were found to be intermingled within transitional subgrains demarcating a limited gradient from one chemical composition to the other. These peculiar interfacial grains revealed that the cohesive mechanisms between the rubbing surfaces occurred in the single-phase β domain under severe strain and high-temperature conditions. During the hot deformation process, the mutual migration of the crystalline interfaces from one material to another assisted by a continuous dynamic recrystallization process was identified as the main adhesive mechanism at the junction zone. The latter led to successful cohesion between the rubbing surfaces. Once the reciprocating motion stopped, fast cooling caused both materials to experience either a β lean →α′ or β lean →β metastable transformation in the interfacial zone depending on their local chemical composition. The limited process time and the subsequent hindered chemical homogenization at the transition zone led to retaining the so-called intermingled α'/β m subgrains constituting the border between both Ti-alloys. Image 1 • The β-metastable Ti17 & quasi-α Ti6242 alloy grades were successfully joined by LFW. • Thermomechanical processing conditions led to a β-fragmentation process in the joint. • Mutual crystalline interfaces migration between the materials induced by β-CDRX. • Cohesion obtained above β-transus resulting in a β-microstructural continuity. • High cooling rates resulted in a sharp α'/β phase contrast in the junction zone. [ABSTRACT FROM AUTHOR]

The synthesis of graphene on thin copper film deposited on quartz substrate is reported. The copper films are fabricated with different thickness of 300 and 1150 nm and then crystallized during thermal annealing that occurs at temperature of 950 and 1000 °C for 30 or 90 min. The size of copper grains increases with increasing of the temperature and the time of annealing that results in increasing of graphene film size. The deposited copper films are studied by electron backscatter diffraction and synthesized graphene films are analyzed by Raman spectroscopy and scanning probe microscopy. Proposed phase contrast mode of the scanning probe microscopy demonstrates high lateral resolution and sensitivity to the presence of graphene with different number of layers. It is found that graphene monolayer is preferably formed on the surface of copper grains with orientation {111} and proposed techniques can be used for the analysis of the evolution of graphene growth. [ABSTRACT FROM AUTHOR]

This paper reports the analysis of the intensity of diamond line in the Raman spectra of laser modified layers with different thickness on a diamond surface. Since the diamond line passing from substrate through the absorbing layer of moderate thickness can be registered, the thickness of local area is estimated from its micro‐Raman spectra. The comparison between Raman scattering and direct observation of the graphitized layer by transmission electron microscopy shows that Raman spectroscopy can be used as an alternative non‐destructive method for measuring a moderate thickness of graphitized layers. [ABSTRACT FROM AUTHOR]