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High quality heterojunctions based on dual acceptor doped ZnO:(As,Sb) films grown on n-type GaN templates were used for UV detector application. Photodetectors made on the obtained diodes appeared to have a high selectivity in the UV spectral range. Photocurrent measurements revealed a very narrow response window of ∼12 nm only. The difference between the dark and bright current was large and the ratio of these currents was about 103. The response time of the detectors is shorter than 1 ms. [ABSTRACT FROM AUTHOR]

The performed research was aimed at determining thermodynamic stability of structures of Ni-Mn-Cu cast iron castings. Examined were 35 alloys. The castings were tempered at 900 °C for 2 hours. Two cooling speeds were used: furnace-cooling and water-cooling. In the alloys with the nickel equivalent value less than 20,0%, partial transition of austenite to martensite took place. The austenite decomposition ratio and the related growth of hardness was higher for smaller nickel equivalent value and was clearly larger in annealed castings than in hardened ones. Obtaining thermodynamically stable structure of castings requires larger than 20,0% value of the nickel equivalent. [ABSTRACT FROM AUTHOR]

[Display omitted] • Quasi-ternary ZnO/MgO alloys are grown by MBE as an alternative to random alloys. • The highest mean Mg concentration is reaching 72%. • Critical thickness of Mg layers for retaining wurtzite crystallinity is established. • HAADF images confirmed thicknesses of ZnO and MgO layers assessed with two approaches of simulation of XRD diffractograms. • Biaxial strains at interfaces are partly responsible for creation of ZnMgO region, which influences WZ structure retainment. The analysis of heteroepitaxially grown ZnO/MgO superlattices on a -oriented ZnO substrates was described. The influence of unalike natural crystalline structures of ZnO and MgO on the interface's abruptness and retaining wurtzite crystallinity was studied. Wurtzite structure was found to be retained in the MgO thin barriers up to 1.5 nm, but creation of nonuniform biaxial strains and some interdiffusion of Mg from barriers to ZnO QW's seemed to be inevitable. The complex strain/composition heterogeneities can be explained by the difference of vapor pressure between Mg (p = 1.93 Pa) and Zn (p = 0.22 Pa) elements at growth temperatures and high mobility of Mg atoms, which are gladly incorporated into ZnO matrix. As a result, a subtle three monolayers in size ZnMgO film was created at the interfaces, which was partly responsible for retaining the wurtzite structure of coherently grown MgO layers. [ABSTRACT FROM AUTHOR]

The paper presents a semi-industrial reactor designed for microwave utilization of waste moulds and cores made of moulding sands prepared infurane resin technology. It was found that a possibility exists of effective incinerating this way prepared residues of cores separated from moulding sands or waste moulds left after casting. The preliminary tests evidenced that microwave heating is an effective way of disposing waste moulding sands and the applied apparatus permits effective control of the microwave heating process. [ABSTRACT FROM AUTHOR]

The paper presents results of preliminary examinations of possibility to measure binder content in traditional moulding sands using a new method employing electromagnetic waves. The presented examinations were carried-out with use of an innovative test station, the so-called microwave slot line. The measurements of binder content in moulding sand were based on the results of power balance investigation of microwaves affecting the specimen. An advantage of the suggested, new method of binder content measurement is short measuring time. [ABSTRACT FROM AUTHOR]

We report on the characterization of wide-band-gap heterojunction diodes based on the p-ZnO/n-GaN material system. The layer structure consists of 11 µm GaN on sapphire substrates and As-doped ZnO film of thickness 0.4 µm obtained by plasma-assisted molecular beam epitaxy (PA-MBE). The quality of the heterojunction was examined by x-ray diffraction, atomic force microscopy and scanning electron microscopy. The arsenic concentration in ZnO, measured by secondary ion mass spectroscopy (SIMS), is 5 × 1020 cm-3. The maximum forward-to-reverse current ratio IF/IR is of about 105 in the applied voltage ±3 V, a very good result for this type of heterojunction. [ABSTRACT FROM AUTHOR]

The idiopathic hypereosinophilic syndrome (HES) comprises a heterogenous group of disorders characterized by marked blood eosinophilia with eosinophilia-associated organ damage. Eight patients with a median age at diagnosis of 42 years (range 19-67) received imatinib mesylate (IM) for FIP1L1-PDGFRα-negative HES resistant to previous conventional treatment. Median number of prior therapies was 3 (range 2-4). Median time from diagnosis to IM initiation was 112 months (range 2-293). Four patients were treated daily with 100 mg IM, whereas the remaining four patients were treated daily with 400 mg IM. Four male patients (50%) achieved complete haematologic response (CHR) after median of 7 days (range 3-150) using 100 mg daily IM (n = 2) and 400 mg (n = 2). Median duration of IM treatment for IM responders was 18 months (range 2-88). No adverse events were reported throughout the treatment duration. Two patients maintained CHR while on 100 mg weekly IM. Four patients (2 men and 2 women) failed IM treatment. Median duration of IM for non-responding patients was 3 weeks (range 3-12). Non-responding HES patients were significantly older and had lower percentage of blood eosinophilia when compared with IM responders. Our results suggest that IM, even at lower than conventional doses, may induce and maintain long-term remission for FIP1L1-PDGFRα-negative HES. [ABSTRACT FROM AUTHOR]

The basic structural and detailed analysis of the optical properties of homoepitaxially grown ZnO/MgO superlattices (SLs) on a-oriented ZnO substrates, containing 30 periods of layers, was described. We found using Rutherford backscattering spectroscopy that the wurtzite coordination collapses in the SLs with 3 nm MgO thick barriers. This novel information allows taking this value as the limit for the maximum MgO barrier thickness in such structures. The observed luminescence and the performed calculations of excitonic transitions suggest that such a high energy barrier of MgO allows treating the ZnO layers in these SLs as separate, non-interacting quantum wells. Cross-sectional SEM-CL line scans revealed MgO layer thickness-dependent biaxial strains built up in the QWs structures. [Display omitted] • Quasi-ternary ZnO/MgO alloys are grown by MBE as an alternative for random alloys. • The highest mean Mg concentration is reaching 72%. • Critical thickness of Mg layers for retaining wurtzite crystallinity is established. • Theoretical calculations confirm observed PL emission and deliver confirmation of ZnO QWs layers thicknesses. • CS-CL line scans revealed a ZnO D0X line blue shift in the SL, pointing to MgO thickness dependent biaxial strains build-up. [ABSTRACT FROM AUTHOR]

The paper presents the results of applying microwaves to support the drying, redrying and hardening process of molding and core sands made of different types of matrix. In the tests of the microwave heating process a slot line measuring stand was used. Being based on the dielectric parameter measurement it enabled the evaluation of power losses of microwaves penetrating: chromite, magnesite, corundum, zircon and silica molding matrix samples. The survey revealed an impact of humidity and chemical compound of sands on microwave absorption. The study enabled the systematization of knowledge about the influence of selected types of matrix on the effectiveness of the microwave heating process. [ABSTRACT FROM AUTHOR]

Two types of simple monolithic photonic ZnO/ZnMgO structures, differing by a factor of two in thicknesses of individual components and grown on m-ZnO substrates, are tested to determine limitations in obtaining their good quality at Mg concentrations close to the limit for phase segregation (~40–45%). The studied structures were composed of 5.5 pairs of ZnO/ZnMgO bilayers (20/22 and 40/45 nm), the central ZnO microcavity (70 and 140 nm) and 5 bilayers on top. Actual layer thicknesses were verified using Scanning Electron Microscopy. Rutherford Backscattering Spectrometry was used to determine the Mg content. The X-ray rocking curves revealed high periodicity and proved that the wurtzite structure was retained without precipitates of foreign phases. Reciprocal space maps and the calculated lattice constants indicated that the layers were strained. Excitonic lines in cross-sectional cathodoluminescence (CL) spectra from individual ZnO layers are blue-shifted compared to emissions from ZnO substrates, thus confirming the presence of strain. The CL intensity of the first ZnMgO layers deposited on ZnO substrates and on both interfaces of the central microcavities was low thus suggesting an effective generation of misfit defects, especially in thicker structures. Reflectivity measurements confirmed the existence of cavity resonance at 385 nm and stop band at 370–400 nm in the photonic structure with a 140 nm microcavity. The results show that defect engineering at the initial stages of deposition of ZnMgO layers with high Mg is critical for the optimization of all-ZnO photonic structures. • Non-polar ZnO/ZnMgO photonic structures grown by MBE on m-ZnO. • HRXRD studies and RSM mapping of the structures. • Wurtzite structure of ZnMgO layers ZnO/MgO superlattices is retained. • SEM-CL mapping reveals generation of misfit defects on interfaces. • Positions of CL lines reflect variation of strain in indyvidual ZnO layers. [ABSTRACT FROM AUTHOR]

Abstract Plasma-assisted molecular beam epitaxy growth of ZnO and Zn 1-x Mg x O epilayers on Al 2 O 3 (11–20) substrates is described. The influence of the substrate temperature on the growth rate and magnesium concentration in Zn 1-x Mg x O epilayers was studied in detail. It was found that the composition of magnesium in Zn 1-x Mg x O epilayers increased with increasing substrate temperature. The composition variation in the alloys as a function of the growth temperature could be explained by the difference of vapor pressure of Mg and Zn at high growth temperature. Theoretical approaches to surface evaporation of metal atoms under different growth condition are difficult. Here, we describe an uncomplicated method determine quantities experimental to obtain. These results can be extended to other types of ternary or quaternary materials grown by MBE technique. Graphical abstract Image 1 Highlights • The ZnO/Zn 1-x Mg x O layers was grown by MBE technique on sapphire-a. • The composition of Mg in Zn 1-x Mg x O epilayers increases with substrate temperature. • Experimental method of metal evaporation rate assessment in MBE has been proposed. [ABSTRACT FROM AUTHOR]

Epitaxial ZnO films implanted with ytterbium have been studied by combination of channeling Rutherford backscattering spectrometry and Hall measurements. This approach is able to shed more light onto the difficult problem of optical activation of Yb implanted into the ZnO lattice. ZnO films grown by atomic layer deposition on a GaN/Al 2 O 3 substrate were implanted with Yb + ions to the fluences of 5 × 10 14 , 1 × 10 15 and 5 × 10 15 at./cm 2 . RBS/c spectra show that for as implanted samples the fraction of implanted Yb ions occupying substitutional lattice positions amounts to 72%, 54% and 22%, respectively. Annealing under an ambient atmosphere at 800 °C leads to a partial recovery of the crystal lattice but also substantially reduces substitutional fraction of Yb atoms. Photoluminescence studies on the as-implanted samples revealed a very weak luminescent peak in the near-infrared region, which slightly increases with a fluence. The annealing process leads to optical activation of Yb 3 + ions and significantly increases the previously observed the near-infrared inter-ionic emission. The results obtained from Hall measurements indicate that after implantation Yb ions are mainly in the 2 + state and are transformed to the optically active 3 + state as a result of annealing. It suggests that the process of optical activation via annealing is related not only to lattice recovery, but also to Yb diffusion from substitutional to interstitial positions, where Yb ions are in the optically active 3 + state. [ABSTRACT FROM AUTHOR]

The optical properties of short period {CdO/ZnO} superlattices (SLs) grown by plasma assisted molecular epitaxy were analyzed. SLs structures were successfully obtained at various growth temperatures from 360 to 550 °C. Using XRD and SIMS measurements we observed that the growth temperature significantly affects the crystallographic quality of the multilayer structures and, as a rule, the lower growth temperature the better their quality and, in particular, SIMS measurements revealed in-depth oscillations of Cd composition after the growth at 360 °C. Luminescence studies showed that near-band-edge (NBE) luminescence in the UV region dominates in as-grown samples. We found that rapid thermal annealing (RTA) at 900 °C strongly influences the optical properties of these structures. In particular, the NBE emission peaks broaden and redshift towards lower energies in comparison to as-grown structures. Also, various intense defect luminescence bands are detected and their intensities and spectral positions depend on the growth temperature. These results suggest that the SLs degrade during annealing due to intermixing of Zn and Cd atoms and the final defect structure in RTA annealed samples is determined by their initial distribution. • Superlattices CdO/ZnO were grown by MBE at different temperatures. • Optical absorption and photoluminescence measurements of CdO/ZnO super-lattice were performed. • The higher growth temperature, the stronger defect luminescence after annealing. • Annealing shifts the luminescence peaks to lower energy. [ABSTRACT FROM AUTHOR]

Abstract ZnO thin films have been realized via monodoping antimony (Sb) acceptor by Molecular Beam Epitaxy on a -Al 2 O 3 substrates. The influence of annealing on photoluminescence (PL) and micro-Raman spectra of ZnO:Sb layers was analyzed. PL spectra recorded at 6 K are dominated by two peaks: at around 3.31 eV and 3.35 eV. First one is assigned to free electrons to neutral acceptors (FA) transition and the second peak corresponds to donor bound exciton (D0X). In order to properly identify and analyze Raman modes, the room temperature Stokes Raman spectra were compared with the spectra of similar ZnO:As/Al 2 O 3 structures. In addition to regular ZnO and Al 2 O 3 modes, recorded ZnO:Sb Raman spectra contain 3 additional modes at around 509, 532 and 575 cm−1 that are associated with antimony doping. The intensity of doping-related bands decreases with increasing annealing temperature, which indicates the improvement of crystalline quality of the structure. The spectra also reveal the presence of compressive in-plane strain that decreases in value with increasing annealing temperature and is due to thermal residual stress, resulting from differences in thermal expansion coefficients of ZnO and Al 2 O 3 Graphical abstract Image 1 Highlights • ZnO:Sb/a-Al 2 O 3 thin films have been realized by Molecular Beam Epitaxy. • The influence of annealing on PL and micro-Raman spectra was analyzed. • 6 K PL spectra are dominated by FA (3.31 eV) and D0X (3.35 eV) peaks. • Raman spectra contain 3 additional modes associated with Sb doping. • Compressive in-plane strain is present in the ZnO:Sb/a-Al 2 O 3 structures. [ABSTRACT FROM AUTHOR]

Epitaxial thin ZnO films grown by Atomic Layer Deposition were implanted with 150 keV Pr ions to a fluence of 1 × 10 15 at/cm 2 . Implanted samples were subjected to two different kinds of annealing: rapid thermal annealing (RTA) and millisecond-range flash lamp annealing (FLA). Structural properties of implanted and annealed ZnO and the optical response were evaluated by the Channeling Rutherford Backscattering Spectrometry (RBS/c), High-resolution X-ray diffraction and Photoluminescence Spectroscopy (PL), respectively. The results shown, that both annealing techniques lead to recrystallization of the ZnO lattice, that was damaged during the ion implantation. Upon RTA performed at 800 °C a return of Zn atoms from interstitial to their regular site positions is accompanied by rejection of primarily substitutional Pr atoms to the interstitial sites. Consequently, it leads to the out-diffusion and precipitation of Pr atoms on the surface. In contrast to RTA, the diffusion of implanted Pr during a millisecond range FLA treatment is completely suppressed. Despite differences in location of Pr inside the ZnO matrix after FLA and RTA, both annealing techniques lead to the optical activation of Pr 3 + . Interestingly, our RBS/c study for as implanted layers also revealed the anomalous damage peak, called intermediate peak (IP) located between the expected surface and the bulk damage peak. The PL spectra clearly suggest, that the defect which forms the IP, can be assigned to Zn interstitials. The long-time annealing at 800 °C in oxygen atmosphere causes the complete removal of the IP. [ABSTRACT FROM AUTHOR]

Superlattice structures formed using the II-VI family of semiconductors have attracted a great deal of attention due to some unique properties (chemical sensors, UV detectors, lasers, white LED). We present a comparison of optical and electrical measurements of 10-period ZnO/ZnMgO multiple quantum wells (MQWs). The structures have been fabricated on (111) Si by molecular beam epitaxy grown at very high temperatures. The optical properties were analyzed by photoluminescence and cathodoluminescence techniques. Cross-sectional SEM-CL mapping shows that the ZnO/ZnMgO multiple quantum wells are located in ZnMgO nanocolumns. Based on these structures, diodes were processed and characterized by current-voltage (I-V), capacitance-voltage and deep level transient spectroscopy techniques (DLTS). I-V measurements confirm that in both diodes, deep traps govern the conduction mechanisms at a forward bias. DLTS studies yield signatures of these traps as well as those related to the presence of QWs. In particular, DLTS results let us estimate the distance of 30 meV from the QW ground state to the barrier conduction band. [ABSTRACT FROM AUTHOR]

The present study analyzed the kinematic changes under fatigue in highly trained adolescent swimmers during a 50-m all-out front cwal test. Twenty-four girls and fourteen boys aged 12-13 participated in the study. The movement of the hip rim was analyzed using a specialized inertial device equipped with a triaxial gyroscope and accelerometer to measure changes in angular velocity and acceleration. Between the first and second lengths of the pool, the following were observed: a significant (F1.36 = 63.6; p < 0.0001; η 2  = 0.64) increase (34%) in maximum pelvic angle, significant (F1,36 = 6.0; p = 0.0193; η 2  = 0.14;) increase (12.10%) in angular velocity in rotational motion around a vertical axis, and a significant (F1,36 = 11.29; p = 0.0018; η 2  = 0.24) increase (6.86%) in angular velocity in yaw rotation motion around the sagittal axis. Significant (F1,36 = 13.96; p = 0.0006; η 2  = 0.28) differences in maximum pelvic angle were observed for lap and side. As unfavourable changes in kinematics are already observed in the second half of the distance, it is therefore suspected that performing frequent high-intensity repetitions may lead to the perpetuation of unfavourable movement patterns. Taking this into account, coaches should limit maximum-speed swimming in adolescent athletes to short distances and an appropriate interval and use training methods to reduce asymmetric work such as training snorkels., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

The aim of this paper is to draw attention to the direct source of primary microplastics (MPs) that have been entirely neglected so far, namely by providing qualitative studies of the fishing ground baits with glitters. Among many microplastic sources already detected in fishing and angling gear and reported in the literature, the glitters in synthetic pastry are the only primary source (produced <5 mm; P-MPs), with MPs placed directly into the freshwater, during sports competitions and individual leisure activities, and were so far not discussed. Dozens of different fishbait pastry products available on the market containing glitters were funded to represent, from the material point of view, only three different classes studied further. Fourier-transform infrared (FTIR), ATR-FTIR and Raman spectroscopy combined with scanning electron microscopy with an energy-dispersive detector (SEM/EDS) enabled the characterization of their composition and morphology. Glitters are composite structures with an internal core and several chemical layers symmetrically placed on both sides. The polymer origin of particles, with the polyethylene terephthalate (PET) core, was confirmed as being an essential condition to classify them as P-MPs. One should focus on the fact that those primary microplastics are designed purposely to be particularly attractive and ingested by fishes, thus being efficiently introduced to the trophic chain with all persistent consequences, including their contribution to the plastisphere. The preliminary qualitative results of environmental stability were obtained in the accelerated ageing test to discuss the possible long-term ecological implications further. Glitters were durable in the saltwater (both natural and used for weathering in the ageing chamber) and in the seabed sediments. The primary weathering test was performed in marine environments, as oceans are the final destination of most freshwater MPs. Finally, suggestions for future studies to enlarge the knowledge about this issue are provided., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

In this study, the authors performed a strength analysis of seven groups of commercially available materials based on SLS incremental technology. Test samples were made with Original PRUSA SL1S printers, with 10 samples of each type from 7 resins selected for testing. The tests were carried out on an MTS Bionix machine in a static tensile test, during which the basic mechanical properties were determined. This is also a preliminary study to determine material constants in the Johnson-Cook strength model. The authors then performed numerical simulations to mirror the experimental tests in order to tune the rheological model. In addition, a fracture criterion was determined based on a hybrid FEM/SPH numerical method. This allowed for the expansion of material libraries currently used in numerical simulations, as well as the sensitivity of the materials' models. In subsequent studies, in order to determine the nature of material destruction, analysis of fracture surfaces was performed using a scanning electron microscope (SEM). The final study was a biocompatibility test to assess the biological properties of the material. The conducted research made it possible to determine the strength properties of resins currently used in 3D printers, expand the libraries of material models in the computational environment (with an error rate of less than 5%), as well as observe the nature of the cracks formed and biocompatibility in the context of predicting the use of these materials for biomedical applications.

The molecular beam epitaxy (MBE) technique is renowned as the most suitable for the growth of high-quality crystalline materials and nanostructures such as GaAs. However, once established, optimal growth parameters required for repeatability of top-quality structures may be easily lost as MBE is highly sensitive to any changes in the system. Especially, routine servicing procedures, which include any activity which requires unsealing of the growth chamber, are devastating for developed growth parameters and force the necessity of recalibration. In this work, we present the process of growth parameter pre-optimization for obtaining homoepitaxial GaAs layers after servicing and restarting the MBE system. Namely, we present how each step of reestablishing optimal growth condition influences various characteristics of obtained GaAs layers. Those include in situ, structural, and spectral measurement techniques. An additional aspect was to compare the optimal conditions for the growth of homoepitaxial GaAs layers from two growth campaigns in which the main difference is the addition of an ion pump and increasing the temperature gradient on the Ga cell., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)