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Multiphase boride layers consisting of (CoFe)2B, (Fe0.4Mn0.6)B, Cr2Ni3B6 and (Cr0.4Mn0.6)B were formed on the surface of Co1.21Cr1.82Fe1.44Mn1.32Ni1.12Al0.08B0.01 high entropy alloy by powder-pack boronizing at 900 °C, 950 °C and 1000 °C for 4 h. The nanohardness (H), modulus of elasticity (E) and fracture toughness (KC) of the multiphase boride layers were determined based on the load–displacement (P-h) curves obtained in the nanoindentation tests. Three distinct regions were identified on the cross-sections of the produced layers: an outer layer consisting of MeB-type borides, an inner layer consisting of Me2B-type borides and the transition zone. The microstructural aspects of the layers were investigated using scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction. Detailed analysis of the influence of the chemical composition on hardness, elastic modulus and fracture toughness in the three regions indicated that the most critical factor influencing the mechanical properties was the presence of chromium, iron and cobalt borides in the microstructure. Especially the formation of chromium borides reduced the fracture toughness of the transition zone.

Refractory high entropy alloys (RHEAs) have shown great promise for a multitude of advanced engineering applications due to their high mechanical stability from cryogenic temperatures to 1600 °C. However, the low ductility they exhibit at room temperature limits their machinability when traditional machining techniques are used. Studies on the nontraditional machining of RHEAs, on the other hand, are very limited. In the present work, MoNbTaTiZr RHEAs subjected to wire electrical discharge machining (WEDM) were examined using electron microscopy, contact profilometry, and nanoindentation. Voids, microcracks, and recast material were observed on the machined surfaces. A transition from roughing to finishing decreased the amount of recast material, but the density of observable voids and microcracks on the surface increased. Optimal results were obtained by finishing, where the surface quality was improved by the removal of recast material remaining from prior passes. The brass wire electrode provided a smoother surface while the copper-core electrode provided minor heat-affected zone in the MoNbTaTiZr samples. In the roughing cuts, a 7.00% improvement in surface roughness was achieved using the copper-core electrode compared to the brass electrode. In the semi-finishing and finishing cuts, the brass wire electrode provided improvements of 13.68% and 22.68%, respectively, compared to the copper-core electrode. On the other hand, the wear of the brass electrode was as much as 20.98% higher than that of the copper-core electrode.

International Conference on Photovoltaic Technologies (PVCon) -- JUL 04-06, 2018 -- Middle E Tech Univ, Culture & Convent Ctr, Ankara, Turkey, WOS: 000499762300011, In the present study, using a large area roll-to-roll DC magnetron sputtering system deposition of ITO thin films on polyethylene terephthalate (PET) substrates were achieved. In order to investigate the effect of growth conditions on the film properties all through the deposition process, optical emission spectroscopy (OES) analysis have been accomplished in a governable way. The consequences of Oxygen partial pressure and film thickness on electrical, and optical properties of the films were determined. It was shown that the intensity of optical emission peaks are subjected to the discharge power and as well as the O-2/Ar flow ratio. Large area, uniform ITO films with relatively high transparency and low electrical resistivity (R(2)(

In this study, we developed fast and highly sensitive, label-free Ca-doped cupric oxide (CuO) based che-miresistive biosensors to detect C-reactive protein (CRP). The Successive Ionic Layer Adsorption and Reaction (SILAR) method was used to deposit pure and Ca-doped CuO thin films on interdigitated gold electrodes. Film surfaces were functionalized with monoclonal anti-C-reactive protein antibody (anti-CRP) by random physisorption method. Sensor fabrication steps were monitored using the linear sweep vol-tammetry method. Scanning electron microscopy was used to investigate the surface morphology. Energy-dispersive X-ray spectroscopy was used to determine the elemental composition. The structure of the films was investigated by the powder X-ray diffractometry method. Sensor parameters were determined by the change in sensor resistance over time. The sensors showed a good response to CRP with a linear detection range of 0.1-5.0 pg/ml, which was within the clinically significant range. Detection limits of 49.61 and 48.81 ng/ml were estimated using the standard deviation of the y-intercept and the standard deviation of the regression line, respectively. Dynamic response times of all fabricated sensors were found to be less than 30 s (c) 2022 Elsevier B.V. All rights reserved.

WOS: 000451757200009, Research on sustainable concrete has drawn scientist's attentions on industrial by-products and wastes. Thus, consumption of raw materials would be diminished. In this study alkali activation of electric arc furnace slag (EAFS) was studied with a comprehensive test program. Different silicate modulus, sodium concentrations, curing conditions, curing temperatures and relative humidity condition variables were selected. Their effects on mechanical and micro structural behaviors of the mortar were investigated through SEM - XRD analyses. Result of this study, EAFS was activated with sodium hydroxide and sodium silicate solutions. Test results also revealed that increase in relative humidity, curing temperature and curing time had positive effects on strength parameters due to diminishing micro cracks and altering hydration reactions. With the current study utilization of EAFS is thought to be successfully disposed.

Multiband absorption is the interest of the microwave communities due to several applications in sensing, filtering, and stealth. Usually, the stacking of metal and dielectric multilayered structures form a multiband absorber which makes the device bulky and costly. In this paper, we investigate a multiband absorber based on a single-layered fractal metasurface for the 5G applications. The unit cell of the fractal metasurface is comprised of six ring-shaped symmetric split-ring resonators (SRRs) connected back-to-back with each other. The absorptivity is investigated in the 5G microwave regime (22-36 GHz) for various obliquities at different substrate thicknesses. Simulation results show that the proposed fractal metasurface has several absorption peaks in different 5G bands. Furthermore, measured results agree well with the simulation results. The proposed absorber can play an important role in 5G applications wherein sensing the angle of incidence and polarization of the incoming electromagnetic waves is desired.

a bstract In this study, different types of waste aluminum produced in daily life and their pure equivalents were evaluated and compared in terms of their hydrogen generation performance through the water-splitting reaction. An experimental system was designed for the production process that consisted of electrodes, DC power supply, alkaline solution, and various waste aluminum products. The hydrogen generation rate of the aluminum source was then measured to determine the optimum conditions for hydrogen production with different types of pure and waste aluminum, normality of the aqueous solution, and applied DC voltage. The best results for micro-hydrogen generation were obtained using pure powder Aluminum, which was attributed to the increased active surface area for the reaction. For beverage can waste (and its powder form), the maximum hydrogen generation rate (cm3/g.min) was achieved using the powder form of the waste aluminum at 2 N alkaline solution. However, the total amount of hydrogen generation (cm3/g) yielded different results compared to the maximum hydrogen generation rate where, when the amount of hydrogen generation volume per mass was considered, the beverage can pieces achieved the best result under constant voltage. This result was attributed to a longer total reaction time.

In this study, titanium carbide (TiC) coatings were grown on the surface of a spheroidal graphite cast iron (SGI) via thermo-reactive diffusion (TRD) using powder-pack processing at 800 °C, 850 °C and 900 °C for 4 h. The TiC coatings obtained on the SGI were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), surface profilometry, microhardness, VDI adhesion testing, wear testing, and electrochemical corrosion testing. Depending on the TRD temperature, continuous, crack-free, and smooth TiC coatings of 5–11 μm thickness and 27.96–32.45 GPa hardness were obtained on the surface. The high chemical stability, high hardness, and good adhesion strength of TiC coatings resulted in a reduced friction, high wear resistance, and superior corrosion resistance compared to the untreated sample. Delamination and oxidation assisted abrasive wear transformed into oxidation-assisted adhesive wear in the coated samples. Galvanic corrosion was dominant in untreated SGI, while homogeneous corrosion occurred in the coated samples. TiC coatings grown using TRD have the potential to be used in engineering components exposed to tribo-corrosive conditions.

Small cell lung cancer (SCLC) is highly associated with the risk of early metastasis. Neuron-specific enolase (NSE), a biomarker of SCLC, is directly related to tumor burden and early diagnosis. This biomarker exists in nerve tissue and neuroendocrine tissue. In this study, an electrochemical NSE immunosensor based on gold nanoparticles modified molybdenum disulfide and reduced graphene oxide (AuNPs@MoS2/rGO) as the electrode platform and CoFe2O4@Ag nanocomposite as the signal amplification was developed. The immobilization of anti-NSE capture antibody was successfully performed on AuNPs@MoS2/rGO modified electrode surface by amino-gold affinity and the conjugation of anti-NSE secondary antibody on CoFe2O4@Ag nanocomposite was successfully completed by the strong esterification reaction. The final immunosensor was designed by the specific interactions of electrode platform and signal amplification. The fabricated nanocomposites and electrochemical immunosensor were characterized by both physicochemical characterization techniques including transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), fourier transform infrared spectroscopy (FTIR), and electrochemical methods such as cyclic voltammetry (CV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS). The quantification limit (LOQ) and the determination limit (LOD) were computed to be 0.01 pg mL(-1) and 3.00 fg mL(-1), respectively. In brief, it can be speculated that the constructed electrochemical NSE immunosensor can be successfully utilized in the early diagnosis for lung cancer. (C) 2022 Elsevier B.V. All rights reserved.

The aim of this study is to develop inhibitive drilling fluid systems generated from waste materials that can contribute to the reduction of potential well instability problems caused by drilling fluid based on rheological and filtration properties. In this study, a comprehensive experimental work was carried out to assess suitability of fly ash and rice husk ash, which are quite a large amount of waste, in inhibitive water based-drilling fluids at ambient temperature. To this end, inhibitive drilling fluids systems were formulated with various concentrations (0, 1, 3, 5, 7, 9, 12.5, 15 (wt%)) of fly ash and rice husk ash with 0, 2, 4, 7, 9, 12.5, 15 (wt%) concentrations in the two type of inhibitive drilling fluid systems and combined use of fly ash and rice husk ash with their optimum concentrations determined was analyzed in the inhibitive drilling fluid in order to determine the drilling fluid with the most favorable characteristics based on rheological and filtration properties including apparent viscosity (AV), plastic viscosity (PV), yield point (YP), gel strength, fluid loss and mud cake thickness. In addition, grinding impact of fly ash particles in the inhibitive drilling fluid system was determined in the development of the drilling fluid by employing mechanically ground fly ash for 30, 60 and 120 min in a tumbling ball mill. Finally, fly ash and rice husk ash were characterized based on X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Experimental results show that developed drilling fluids with fly ash and rice husk ash not only enhanced rheological properties but also improved the filtration properties by increasing the rheological parameters and decreasing fluid loss and mud cake thickness. With the developed drilling fluids, AV, YP and PV increased by 35%, 32%, 28%, respectively with fly ash for the 12.5 wt% concentration while the parameters increased by 19%, 27%, 14%, respectively with the 4 wt% rice husk ash. Gel strengths of the fluids slightly increased compared to reference fluid and were in acceptable range. On the other hand, developed drilling fluid resulted in a 10% and 12% reduction in fluid loss for fly ash and rice husk ash at 12.5 wt% and 4 wt% concentrations, respectively, as well as a 54% and 63% reduction in mud cake thickness. In addition, the results reveal that developed drilling fluid with sieved fly ash yielded superior flow behavior compared to drilling fluid formulated with ground forms of fly ash. Consequently, based on the study, non-damaging and inhibitive drilling fluid systems were developed by using waste material fly ash and rice husk ash, and hence enhancing performance of drilling operation as well as reducing the risk of amount of wastes disposed to the environment and the potential of issues such as formation damage, wellbore instability caused by drilling fluid and associated challenges.

WOS: 000440458100007, In this study K-alpha 1, K-alpha 2 and KLL Auger line widths were determined semi-empirically by using K shell fluorescence yields of sulfur even if K-alpha X-ray lines cannot be resolved in our detector system. The samples of 1,2,4-Triazoles were irradiated by an annular 50 mCi Fe-55 radioactive source. It was found that halogens (e.g. Cl) and electron donating groups (e.g. -CH3, -OCH3, -OH etc.) have a crucial effect onto the valence shell structure of sulfur. The expansion of Auger line widths was attributed to the Coster-Kronig transitions in L shells which are energetically possible. (C) 2018 Elsevier B.V. All rights reserved.

WOS: 000399499000074, In this work, we introduce a three-layer sandwich composite structure having an aromatic thermosetting copolyester (ATSP) foam core with two aluminum foam face layers joined together by an in situ generated foaming mechanism. The ATSP foam core was synthesized on-site between the aluminum foam layers via a heat-induced polycondensation reaction. Upon curing, the ATSP foam core adhered to the aluminum foam layers through an interfacial compatibility-enabled chemical bonding. Lap shear experiments demonstrated that the bond strength clearly surpassed the tensile performance of the bare aluminum foam parts. Drop-weight impact tests showed that the three-layer sandwich structure could absorb four times the impact energy as compared to the bare aluminum foam of the same overall thickness. (C) 2017 Elsevier B. V. All rights reserved., National Science Foundation (NSF) I/UCRC [IIP-1362146], We sincerely thank Dr. David Farrow for helping with the experiments. We gratefully acknowledge funding from the National Science Foundation (NSF) I/UCRC grant (IIP-1362146). The findings, conclusions, and recommendations expressed in this manuscript are those of the authors and do not necessarily reflect the views of the NSF.

AISI 900 series stainless steels are considered as low-cost alternatives to nickel-based superalloys used for highly corrosive environments. However, in terms of mechanical properties, they have average strength and hardness similar to other austenitic stainless steel grades and this often limits their use. If a 900 series alloy were to be used under tribocorrosive conditions, its surface properties would have to be improved by a wear and corrosion resistant coating. In this study, AISI 904L steel was pack boronized in a solid medium at temperatures of 900, 1000 and 1100 °C for 2, 4 and 6 h with nano-sized boronizing powders. The grown boride layers were evaluated using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffractometry, 2D profilometry, microhardness measurements, ball-on-disk type wear tests and electrochemical corrosion tests. Characterization studies revealed a complex boride layer consisting of FeB, Fe2B, CrB, Cr3B4, Ni3B and Mo2B phases with 2366–2396 HV hardness. Wear tests showed that the abrasive wear resistance of the AISI 904L steel was improved by up to 40 times. The corrosion resistance of boronized AISI 904L was inferior to untreated AISI 904L in 3.5% NaCl, but comparable to AISI 316L.

Electromagnetic (EM) wave shielder mortar can be produced by mixing cement, natural limestone, tap water with mill scale (mill scale-I and mill scale-II) which is one of the biggest disposal area problems of the iron-steel sector in Iskenderun, Hatay. In this paper, the detail analysis and information were presented on the influence of electromagnetic properties of mortars including iron steel industry waste mill scales to contribute the solving waste problems. The mortar samples were prepared using different volume of mill scales (5, 10, 15 and 30%) which were substituted with the natural fine aggregate. The mechanical properties (flexural and compressive strength) and the EM shielding properties (using the free space test method) of the mortars were compared with each other and also a control mortar samples. Our results indicated that the obtained mortars containing 15% mill scale had nearly same mechanical properties with the control mortar and they provided better solution for EM shielding. Especially, the mortar containing mill scale-II might be used to create novel construction material with shielding characteristics in entire wireless communication bands due to the cubic crystal structure and ferromagnetic properties of the mill scale-II. The mortar prepared using mill scale-I might be utilized to fabricate novel high strength radomes that behave as air in transmission respect. All experimental results point out that the waste mill scales are viable candidates for EM wave shielder for the buildings and will gain added value as well as solve the scale storage problem of the iron and steel industry. © 2020 Elsevier Ltd

WOS: 000522652700031, Lithium-doped CuO thin films with different concentrations are deposited by the Successive Ionic Layer Adsorption and Reaction technique on glass substrates. The films are characterized by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, UV-Vis. Spectroscopy, nanoindentation and in-situ scanning probe microscopy. Scanning electron microscopy showed uniform film surface and smaller particle size with increasing Li concentration. X-ray diffraction patterns revealed decreasing crystallite size with increasing Li concentration. The Raman spectra revealed CuO phases and a secondary phase of Cu2O at high doping concentrations especially after the concentration of 1.0 at.% Li. UV-Vis. Spectroscopy results indicated that the transmittance and bandgap values could be modified with Li-doping. Both of them are found to be increasing with increasing Li concentration. All indentation test load curves exhibited a smooth shape without any detected pop-in. The results of the nanoindentation test revealed that the nanohardness and elastic modulus increased with Li-doping., Mustafa Kemal University Scientific Research CommissionMustafa Kemal University [12662, 9362], We are grateful to Mustafa Kemal University Scientific Research Commission for the financial support for the projects no. 12662 and 9362.

WOS: 000526980900010, A two-step Thermo reactive diffusion processes (including an initial titatinizing step followed by boronizing) is proposed in order to obtain superhard complex TiBC coating layer on AISI D6 steel. Microstructural characterization and mechanical properties of obtained TiBC layer conducted by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), optical microscopy, 2D profilometer, X-ray diffraction (XRD), micro-hardness, nano-indentation hardness and ball-on disc wear tests. Wear tests were carried out in ball on disc device by applying 30 N load and 500 m sliding distance against WC abrasive ball. Microstructural studies revealed a compact, homogenous and crack-free TiBC layer with 0.29-1.91 surface roughness (Ra), 3.65-29.5 mu m thickness and 1800-4841 HV0.05, hardness and 146-235 GPa elastic modulus. Hardness values of TiBC layers was significantly higher than those obtained by standard titanizing and boronizing due to the interspersed TiB and TiC phases within the TiBC layer. Higher hardness values are highly effective on the wear resistance and wear type. Thus, in parallel with the increase in mechanical properties, wear resistance increased in the range of 4-120 times in comparison with the untreated AISI D6 sample. Severe wear and extensive plastic deformation was observed in the untreated AISI D6, while micro-cutting, micro-cracking and pitting was dominant in samples with hardness 1800-4000 HV. When the surface hardness reached values above 4000 HV the wear mechanism further changed to microcracking and spalling.