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Under extremely complex conditions, extending the lifetime of thermal barrier coatings (TBCs) is a challenge. In the present study, optimization of the coating structure and selection of coating materials are beneficial for improving the lifetime of TBCs under thermal cycling-CMAS (calcium-magnesium-alumina-silicate) test. It is efficient to obtain different layer thicknesses of multi-layer coating, including the micro-nano dual-scale layer, the dense YbYSZ layer (4.0 mol % Yb 2 O 3 and 0.5 mol% Y 2 O 3 co-stabilized ZrO 2), the porous YbYSZ layer and the laser 3D texturing layer, using the computational model under thermal load. Based on the corresponding coating structure and YbYSZ material, bond strength and thermal cycling-CMAS lifetime are evaluated, and compared with those of YSZ (4.5 mol % Y 2 O 3 stabilized ZrO 2) coating. The results reveal that TBCs with porous embedded particle cluster (PEPC) structure is lower than that of YSZ coating. In addition, the original defects in multi-layer coating with grid texture reduce the bond strength. The lifetime of multi-layer coatings with a punctate texture are significantly improved in the thermal cycling-CMAS test, and their failure behavior includes fragmented and bulk-like exfoliation. This study emphasizes that combination of materials modification and structure optimization are a promising strategy to extend lifetime of TBCs. [ABSTRACT FROM AUTHOR]

Copyright of Baghdad Science Journal is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The quantitative effects of cutting speed, feed and depth of cut on surface quality of the turned 316 LVM stainless steel work piece and tool wear of the TiAlN/CrN coated insert was investigated using Response surface methodology. Subsequently, FEM analysis of the tool wear using DEFORM-3D software was carried out. ANOVA analysis was formulated and regression was performed to understand the interactive effect of the process variables on the quality indicators. Further, a FEM-based method is defined to predict the advancement of tool wear during cutting operations. The cutting process was simulated using Deform 3D FEM software, and a suitable subroutine was added to the software to assess tool wear. An estimation of the tool wear value is made using well-known analytical models. The FEM model was calibrated and validated through experimental tests by turning 316 LVM stainless steel with ISO P40 TiAlN/CrN coated tools. The results from the FEM analysis and the experimental data were in good agreement. [ABSTRACT FROM AUTHOR]

Particle-reinforced polymer matrix composites (PMCs) are often used as radar-absorbing materials (RAM) in aircraft stealth applications. The thickness evaluation of such multilayered coatings with micrometre-level thickness is highly challenging from single-side access. In this study, we used Terahertz Time-domain Spectroscopy (THz-TDS) in the transmission mode to extract the refractive index of the dielectric coatings for measuring the thickness using the time-of-flight method. A numerical study based on the Finite Element method (FEM) has also been developed to validate the transmission experiments. A frequency-dependent complex dielectric parameters must be considered for coatings with high absorption in the THz regime. This was addressed by performing the finite element simulations in a frequency domain. The thickness of each layer of a multi-layered coating is estimated by carrying out the experiments in reflection mode. Since the interface echoes were overlapping, a deconvolution algorithm and frequency thresholding were employed to reconstruct the signals reflected from the different interfaces. Using this technique, the thickness of each layer of coating is estimated accurately in a single measurement, which was challenging to measure using other conventional non-destructive testing (NDT) methods. [ABSTRACT FROM AUTHOR]

The outstanding tribological performance of transition metal dichalcogenides (TMDs) is attributed to their unique sandwich microstructure and low interlayer shear stress. This advantageous structure allows TMDs to demonstrate exceptional friction reduction properties. Furthermore, the incorporation of TMDs and amorphous carbon (a-C) in multi-layer structures shows excellent potential for further enhancing tribological and anti-oxidation properties. Amorphous carbon, known for its high ductility, chemical inertness, and excellent wear resistance, significantly contributes to the overall performance of these multi-layer coatings. To gain an in-depth understanding of the tribological mechanism and evolution of TMDs' multi-layer coatings, a dual in-situ analysis was carried out using a tribometer equipped with a 3D laser microscope and a Raman spectrometer. This innovative approach allowed for a comprehensive evolution of the tribological, topographical, and tribochemical characteristics of both single-layer WS2 and multi-layer WS2/C coatings in real time. The findings from the dual in-situ tribotest revealed distinct failure characteristics between the single-layer WS2 coating and the multi-layer WS2/C coating. The single-layer WS2 coating predominantly experienced failure due to mechanical removal, whereas a combination of mechanical removal and tribochemistry primarily influenced the failure of the multi-layer WS2/C coating. The tribological evolution process of these two coatings can be classified into four stages on the basis of their tribological behavior: the running-in stage, stable friction stage, re-deposition stage, and lubrication failure stage. Each stage represents a distinct phase in the tribological behavior of the coatings and contributes to our understanding of their behavior during sliding. [ABSTRACT FROM AUTHOR]

This research shows different hard Ti-based coatings deposited over steel substrates using the physical vapor deposition (PVD) method. The graded coating of the three produced Ti, TiN and TiCN were assessed using phase composition analysis and spectroscopy study. The microstructure characterization was studied by X-ray Photoelectron spectroscopy (XPS), Scanning Electron Microscopy (SEM), and transmission electron microscopy (TEM). The results show that integrating Ti interlayer with subsequent TiN/TICN layers can be considered a suitable way to yield hard Ti-based coating with enhanced mechanical and tribological behavior due to nitride and carbonitride phases formed from the breakdown of carbon and nitrogen atoms. The elastic modulus and hardness of all layers were identified by nanoindentation and utilized to achieve yield strength. Later, the curvature of the unloading step and elastic properties are used for finding flow behavior parameters in terms of work hardening factors (n and K). The attained findings extracted from the load–displacement curve of both nanoindentation and nano scratch were analyzed to examine the microscopic performance of all three Ti, TiN, and TiCN coatings. Scratch mechanisms analysis in all coatings shows that the main failures in samples are caused by tensile stress stemming from Hertzian cracks. However, as the force increases, the coating surface undergoes an incremental deformation, and failure mode varies to interfacial spallation.

An industrial submicron-sized Fe2O3 with no special shape was decorated by a multi-layer coating of oxygen-deficient TiO2−x and conducting polymer PEDOT (poly 3,4-ethylenedioxythiophene). A facile sol–gel method followed by an EDOT polymerization process was adopted to synthesize the hierarchical coating composite. The microstructure and phase composition were characterized using an X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). In particular, the existence state of PEDOT was determined using Fourier transform infrared (FT-IR) and a thermogravimetric (TG) analysis. The characterization results indicated the dual phase was well-coated on the Fe2O3 and its thickness was nano scale. Electrochemical characterization indicated that the multi-layer coating was helpful for significantly enhancing the cycle stability of the Fe2O3, and its electrochemical performance was even better than that of the single-layer coating samples. The synergistic effects of the ceramic phase and conducting polymer were demonstrated to be useful for improving electrochemical properties. The obtained FTP-24 sample exhibited a specific discharge capacity of 588.9 mAh/g after 360 cycles at a current density of 100 mA/g, which effectively improved the intrinsic cycling performance of the Fe2O3, with a corresponding discharge capacity of 50 mAh/g after 30 cycles. [ABSTRACT FROM AUTHOR]

Enhancing the machining efficiency of hardened steel using four‐layer coated tungsten carbide tools has gained a lot of interest among manufacturing engineers. This paper reports the machining performance of AISI 4140 steel using TiN/Al2O3/TiCN/TiOCN multilayer coated tungsten carbide tool inserts. The impact of cutting speed, depth of cut, and the nose radius on machining force, tool chip interface temperature, surface roughness, and chip forms was ascertained using full factorial machining experiments and artificial neural network (ANN) methodology. The machining force evaluated using Logistic Sigmoid activation function resulted in the highest root mean square error (RMSE) of 4.076 and regression value of 0.998. The maximum error between the ANN predicted results and experimental results for machining force, cutting temperature and surface roughness was about 2.4%, 5.3%, and 2.07%, respectively. The best architecture for ANN was "3‐6‐4" which had a coefficient of regression value of 0.97. However, in case of chip form, some of the ANN predicted values could not be mapped to ISO standard chip form and hence prediction accuracy of 80% was achieved. [ABSTRACT FROM AUTHOR]

SiC reticulated porous ceramic (SRPC) as the key component determined the service life and combustion characteristics of porous burner. The novel multi-layer struts were constructed to synergistically improve the oxidation resistance and infrared radiation of SRPC, including microporous cordierite coating, dense mullite transition layer, SiC skeleton and filling layer. The continuous mullite transition layer significantly improved the resistance to water vapor oxidation of SRPC, also their strength and thermal shock resistance were enhanced because the elimination of strut defects in multi-layer struts. In addition, the microporous cordierite coating generated from the burnt out of pitch increased the burner surface temperature from 764.4 °C to 1061.7 °C, and obviously reduced the CO/NOx emission due to its improved infrared radiation property. Furthermore, the porous cordierite coating enhanced the heat radiation of SRPC, thus increasing the heating rate of the burner from 29.4 °C/min to 33.1 °C/min in the process of water heating. [ABSTRACT FROM AUTHOR]

Multi-layer coating of electrodes with different material compositions helps unlock the full potential of high-loaded electrodes. Within this work, LiNi0.8Mn0.1Co0.1O2 (NMC811) cathodes with an areal capacity of >8.5 mA h cm−2 and tuned binder concentrations were fabricated by using an industrially relevant roll-to-roll process. Rate capability tests revealed an increase in practical specific discharge capacity independent from the C-rate for cathodes with reduced binder concentration in the top layer. At high current densities (C-rate of 1C) an improved performance of up to 27% was achieved. Additionally, at lower C-rates, binder gradients perpendicular to the current collector have beneficial effects on thick electrodes. However, surface analysis and electrochemical impedance spectroscopy revealed that without an adequate connection between the active material particles through a carbon-binder domain, charge transfer resistance limits cycling performance at high current densities. [ABSTRACT FROM AUTHOR]

The present study evaluates the tribological and corrosion behavior of CrN/CrAlN and CrCN/CrAlCN nanostructured coatings applied on 430 stainless steel. These coatings were applied using the physical vapor deposition method from the vapor phase through the cathodic arc technique. X-ray diffraction, field emission scanning electron microscopy, and nano-indentation techniques were utilized for the coatings characterization. Moreover, the adhesion of the coatings to the substrate was evaluated by the adhesion test according to the VDI3198 standard. The corrosion behavior of the coatings was studied by potentiodynamic polarization and electrochemical impedance spectroscopy in 3.5 wt % NaCl solution in 24, 72, and 168 h. It was observed that CrN was the major phase in the coatings. The results of the Rockwell C test indicated the good adhesion of both coatings to the substrate. The hardness of CrCN/CrAlCN coating was 20 GPa and CrN/CrAlN coating was 18 GPa. Concerning the friction coefficient, 430 stainless steel, CrN/CrAlN, and CrCN/CrAlCN coatings showed friction coefficients of 1.049, 0.3, and 0.21, respectively. CrCN/CrAlCN exhibited the lowest friction coefficient, which can be ascribed to the higher ratio of H3/E2, higher hardness, and also reduced surface roughness compared to the CrN/CrAlN sample. The R p value of CrCN/CrAlCN coating is higher than that of CrN/CrAlN coating at different times. The corrosion current density of the CrCN/CrAlCN coating was 0.003 μA cm−2 and for the CrN/CrAlN coating, it was 0.057. The obtained results from both corrosion tests are in an agreement and indicate the better resistance of the CrCN/CrAlCN coating against corrosion which can be due to the dense structure, lower roughness, and low wettability of this coating. [ABSTRACT FROM AUTHOR]

An industrial submicron-sized Fe2O3 with no special shape was decorated by a multi-layer coating of oxygen-deficient TiO2−x and conducting polymer PEDOT (poly 3,4-ethylenedioxythiophene). A facile sol–gel method followed by an EDOT polymerization process was adopted to synthesize the hierarchical coating composite. The microstructure and phase composition were characterized using an X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). In particular, the existence state of PEDOT was determined using Fourier transform infrared (FT-IR) and a thermogravimetric (TG) analysis. The characterization results indicated the dual phase was well-coated on the Fe2O3 and its thickness was nano scale. Electrochemical characterization indicated that the multi-layer coating was helpful for significantly enhancing the cycle stability of the Fe2O3, and its electrochemical performance was even better than that of the single-layer coating samples. The synergistic effects of the ceramic phase and conducting polymer were demonstrated to be useful for improving electrochemical properties. The obtained FTP-24 sample exhibited a specific discharge capacity of 588.9 mAh/g after 360 cycles at a current density of 100 mA/g, which effectively improved the intrinsic cycling performance of the Fe2O3, with a corresponding discharge capacity of 50 mAh/g after 30 cycles.

Passive radiative cooling is a promising direction in energy conservation and environmental protection. One of the ways to increase the efficiency of radiative cooling systems is the use of multi-layer coatings. In recent years, several novel materials with high emissivity have been proposed, which allow the creation of radiators that provide an average daily cooling power of approximately 100 W/m2 during daytime. Based on the developed mathematical model, the optical properties of the multi-layer coating for the radiative cooling system were evaluated by the Transfer Matrix Method and the effectiveness of radiative cooling was determined due to the use of the multi-layer coating in the climatic conditions of Syria (Latakia). The results of modeling the atmospheric transmittance in the summer months in Syria (Latakia) are presented. The developed mathematical model, methods for modeling atmospheric transmittance, calculating solar radiation, and evaluating the optical properties of multi-layer coating, allow determining an effective multi-layer coating for radiative cooling systems in any climatic conditions

Particle reinforced polymer matrix composites (PMCs) are widely used in the military aviation industry as a stealth coating for incident radar attenuation. These coatings are made up of many layers of different materials with varying thicknesses. In this study, we used terahertz (THz) spectral range by means of time-domain spectroscopy (TDS) to examine the thickness of iron particle reinforced polyurethane radar absorbing paint (FE-PU-RAP) composite coatings non-destructively. For accurate estimation of the individual layer thickness in multi-layer coatings, precise knowledge of the material properties of the individual layers is a prerequisite. Hence, standalone samples of the individual layers have been initially employed to extract the material properties, such as the refractive index and absorption coefficient. Then, the accurate thickness estimation by the time-of-flight measurement principle has been carried out using the reflected THz pulses. Further, since the individual reflected pulses from the multi-layered sample are overlapping in nature due to the optically thin coating thickness, a sparse deconvolution technique has been utilized for extracting each individual reflected time instant. The scattering from the iron particles also provides a challenge to the identification of the interface signals. This was addressed by optimizing the regularization parameter in the sparse deconvolution algorithm. With this technique, accurate estimation of each of the individual layers in the multi-layer sample has been accomplished, otherwise difficult non-destructively. [ABSTRACT FROM AUTHOR]

Multi-layer coating of electrodes with different material compositions helps unlock the full potential of high-loaded electrodes. Within this work, LiNi0.8Mn0.1Co0.1O2 (NMC811) cathodes with an areal capacity of >8.5 mA h cm−2 and tuned binder concentrations were fabricated by using an industrially relevant roll-to-roll process. Rate capability tests revealed an increase in practical specific discharge capacity independent from the C-rate for cathodes with reduced binder concentration in the top layer. At high current densities (C-rate of 1C) an improved performance of up to 27% was achieved. Additionally, at lower C-rates, binder gradients perpendicular to the current collector have beneficial effects on thick electrodes. However, surface analysis and electrochemical impedance spectroscopy revealed that without an adequate connection between the active material particles through a carbon-binder domain, charge transfer resistance limits cycling performance at high current densities.

Supercritical CO2 (SCCO2), characterized by gas‐like diffusivity, low surface tension, and excellent mass transfer properties, is applied to create a SiOx/carbon multi‐layer coating on Si particles. Interaction of SCCO2 with Si produces a continuous SiOx layer, which can buffer Si volume change during lithiation/delithiation. In addition, a conformal carbon film is deposited around the Si@SiOx core. Compared to the carbon film produced via a conventional wet‐chemical method, the SCCO2‐deposited carbon has significantly fewer oxygen‐containing functional groups and thus higher electronic conductivity. Three types of carbon precursors, namely, glucose, sucrose, and citric acid, in the SCCO2 syntheses are compared. An eco‐friendly, cost‐effective, and scalable SCCO2 process is thus developed for the single‐step production of a unique Si@SiOx@C anode for Li‐ion batteries. The sample prepared using the glucose precursor shows the highest tap density, the lowest charge transfer resistance, and the best Li+ transport kinetics among the electrodes, resulting in a high specific capacity of 918 mAh g−1 at 5 A g−1. After 300 charge–discharge cycles, the electrode retains its integrity and the accumulation of the solid electrolyte interphase is low. The great potential of the proposed SCCO2 synthesis and composite anode for Li‐ion battery applications is demonstrated. [ABSTRACT FROM AUTHOR]

The short electrode life is one of the most important problems associated with resistance spot welding of galvanised steel sheets. In this study, a nanolayered multi-layer CrN/(Cr,Al)N coating was deposited on the tip of the electrode by applying the cathodic arc physical vapour deposition process with the layer thickness of about 30 nm and an overall thickness of 1.1 µm. The electrode life test confirmed that the coating could extend the electrode life up to 125%. The coated electrode showed a significantly lower growth rate (∼0.3 µm per weld), in comparison to the un-coated one (∼1 µm per weld). The degradation of the electrode could be subdivided into two subsequent steps: the degradation of the electrode periphery and the degradation of the electrode tip. The CrN/(Cr,Al)N coating could effectively protect the electrode tip periphery from zinc adhesion and postpone the first stage electrode degradation which delayed the second one. [ABSTRACT FROM AUTHOR]

In this work, we consider multilayer coatings of metal-dielectric-semiconductor nanosized layers located on a transparent substrate and described on the basis of the Drude–Lorentz model that serve as multiband screen filters for different frequency ranges. Structures with several layers and quasi-periodic structures are investigated. A method of the approximate synthesis of band gap structures with two layers per period and three layers per period is proposed. For three layers, the difference in plasma frequencies allows one to extend the bands. It is shown that semiconductor layers made of narrow-band crystal materials like InSb are promising for THz-band structures with the ability to adjust the ranges by doping.

Manufacturing thick electrodes for Li-ion batteries is a challenging task to fulfill, but leads to higher energy densities inside the cell. Water-based processing even adds an extra level of complexity to the procedure. The focus of this work is to implement a multi-layered coating in an industrially relevant process, to overcome issues in electrode integrity and to enable high electrochemical performance. LiNi0.8Mn0.1Co0.1O2 (NMC811) was used as the active material to fabricate single- and multi-layered cathodes with areal capacities of 8.6 mA h cm−2. A detailed description of the manufacturing process is given to establish thick defect-free aqueous electrodes. Good inter-layer cohesion and adhesion to the current collector foil are achieved by multi-layering, as confirmed by optical analysis and peel testing. Furthermore, full cells were assembled and rate capability tests were performed. These tests show that by multi-layering, an increase in specific discharge capacity (e.g., 20.7% increase for C/10) can be established for all tested C-rates.

SiCN film is promising coating material in wear-resistance and high strength applications, the interfacial strength between SiCN and substrate is the major issue needs to be concerned. Designing SiCN-based multi-layer coating system is a proper solution. To investigate the mechanical performance of the system, in this work, a nano-indentation model constituted by nano-indenter and SiCN-based multi-layer coating is established by finite element approach. The interfacial properties are investigated by comparing the simulation load - depth (P-h) curves with experimental results. The simulation results indicate that the sharply changed shear stress at interface will significantly decreased by adding the interlayer, and the maximum shear stress decreases with the increase of interlayer thickness. Moreover, the location of the maximum tensile stress for SiCN surface is not at the axis of indenter, which is related to the pile up phenomenon at coating surface. The proposed approach can be used to evaluate and design the mechanical performance of SiCN-based multi-layer system. [ABSTRACT FROM AUTHOR]

Multi-layer coatings (composed of outer hydroxyapatite and inner titania layers) have been synthesized on Ti6Al4V alloy for biomedical applications by employing micro-arc oxidation at positive and negative voltages of 400 and 80, respectively. Addition of silver nitrate (at concentrations of 0.1 g/L and 0.4 g/L) into the calcium acetate hydrate and disodium hydrogen phosphate anhydrous containing base electrolyte provided an enhancement in bio- and antibacterial activities of the synthesized coating, while imposing precipitation of silver nanoparticles on the hydroxyapatite layer. It is finally concluded that addition of 0.1 g/L AgNO 3 into the base electrolyte is promising for MAO process of titanium-based implants, when the structural characteristics and risk of cytotoxicity are of concern for the synthesized multi-layer coatings. [ABSTRACT FROM AUTHOR]

Wet coating methods use organic solvents to prepare layered particles that provide controlled-release medications. However, this approach has disadvantages in that it can cause particle agglomeration, reduce pharmaceutical stability, and leave residual organic solvents. We used a dry coating method to overcome these issues. Fine particles (less than 50 μm in diameter) of controlled-release theophylline were created using theophylline (TP; model drug), polyethylene glycol 20,000 (PEG; drug fixative), hydrogenated castor oil (HCO; controlled-release material), hydrogenated rapeseed oil (HRSO; controlled-release material), and cornstarch (CS; core particle). An ultrahigh-speed mixer was employed to mix TP and CS for 5 min at 28,000 rpm. Subsequent addition of PEG produced single-core particles with a drug reservoir coating. Addition of HCO and HRSO to these particles produced a controlled-release layer on their surface, resulting in less than 10% TP dissolution after 8 h. We successfully demonstrated that this dry coating method could be used to coat 16-μm CS particles with a drug reservoir layer and a controlled-release layer, producing multi-layer coated single-core particles that were less than 50 μm in diameter. These can be used to prepare controlled-release tablets, capsules, and orally disintegrating tablets. [ABSTRACT FROM AUTHOR]

Protective coatings are critical to the successful application of the carbon/carbon (C/C) composites in the thermal protection systems of space vehicles. The damages of such coatings during installation and operation would threaten the safety of flight. In this contribution, an in-field technology based on a multilayer structure was developed to repair the damaged coatings of C/C composites. The multilayer structure contains a silicon buffer inner layer, a mullite heat-resistant middle layer and a borosilicate glass outer layer. The oxidation tests in air at 1300 °C and 1500 °C indicated that the weight loss of the repaired samples was greatly reduced compared with that of the damaged ones. The plasma wind tunnel tests for both repaired and damaged coatings further demonstrated that the multilayer structure could effectively protect the damaged composites from ablation in oxidation environments. [ABSTRACT FROM AUTHOR]

Highlights: [•] Hierarchical porous pluronic-based TiO2 photocatalytic membrane was fabricated. [•] Pore forming agent, pore filler, and binder were used to achieve tunable pore sizes. [•] Different structural configurations were fabricated to optimize membrane performance. [•] Photocatalytic activity was evaluated in the batch and flow-through photoreactors. [•] Membrane exhibited an anti-fouling property with reusability potential. [Copyright &y& Elsevier]

Abstract: Internal stresses in organic coatings can generate loss of adhesion. This phenomenon must then take into account in order to achieve long-term protection. For corrosion protection of steel pipelines, the external coatings are usually three layered. They are composed of an epoxy primer, an adhesive and a thick layer of polyethylene. The presence of internal stresses has been suggested to explain the appearance of some spontaneous disbondments of these coatings after only few years in-service. This finite element study aims to calculate the internal stress generated during the application process for different thicknesses of coating and to compare these with measured values of adhesion. This comparison should allow concluding if this phenomenon is responsible for the loss of adhesion observed. Whatever the thickness of the coating, internal stresses at the interfaces have similar values. However, there in an edge effect at the end of the pipeline that affects values of these stresses. [Copyright &y& Elsevier]

Abstract: This work studied the effect of multi-layer coating of alginate beads on the survival of encapsulated Lactobacillus plantarum in simulated gastric solution and during storage in pomegranate juice at 4°C. Uncoated, single and double chitosan coated beads were examined. The survival of the cells in simulated gastric solution (pH 1.5) was improved in the case of the chitosan coated beads by 0.5–2 logs compared to the uncoated beads. The cell concentration in pomegranate juice after six weeks of storage was higher than 5.5logCFU/mL for single and double coated beads, whereas for free cells and uncoated beads the cells died after 4 weeks of storage. In simulated gastric solution, the size of the beads decreased and their hardness increased with time; however, the opposite trend was observed for pomegranate juice, indicating that there is no correlation between cell survival and the hardness of the beads. [Copyright &y& Elsevier]

Abstract: Formation of multi-layer coating by plasma nitriding and hard chromium electroplating on the surface of H11 hot work tool steel was investigated. Specimens were coated via a triple process containing plasma nitriding, hard chromium electroplating and plasma nitriding. Surface composition has been studied by X-ray diffraction analysis. The surface morphology and elemental analysis was examined by using scanning electron microscopy. Wear tests were conducted by the use of pin-on-disk method, a cemented tungsten carbide pin and 1000 gF load. Polarization corrosion tests were carried out in distilled water solution containing 3% NaCl. The improvement in hardness distribution after third step is discussed in considering the forward and backward diffusion of nitrogen in the chromium interlayer. Also, the formed phases in the hybrid coating were determined to be CrN + Cr2N + Cr + Fe2–3N + Fe4N. Wear results showed that although the multi-layer coated specimens have higher wear resistance in comparison with the reference specimen, their wear resistance is less than that of two and one layer coated specimens due to micro-ploughing and removal of hard surface nitrides from the surface. By increasing the third step time and temperature, the wear resistance of specimens increases due to higher diffusion of nitrogen in the chromium layer. But polarization results showed that triple coated specimens have the lowest corrosion rate. [Copyright &y& Elsevier]

A method for controlling the asymmetry sign of the spectral intensity of light reflected from a narrow-band filter by fitting the dielectric layer thickness adjacent to the thin metal layer is proposed. [ABSTRACT FROM AUTHOR]

Copyright of Revista Fuentes, El Reventón Energético is the property of Universidad Industrial de Santander and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Flank wear analysis on the multi-layer (TiCN/Al2O3/TiCN) coated carbide inserts has been performed after turning AISI 1045 steel. Using advanced microscope and image processing techniques including wavelet transform, we have obtained the flank wear profiles and analyzed the surface roughness and groove sizes on the coating layers to understand the progress of flank wear and its wear mechanisms. The dominant wear mechanism was found to be the abrasion by the cementite phase in the work material. The adhesion took over after carbide substrate was exposed as the notch wear also became more significant. Based on the experimental result, it was concluded that the hardness of the coating is the most important requirement to resist flank wear due to its high wear resistance against abrasion. Therefore, the multilayer coating scheme does not provide any significant benefit to resist flank wear. [Copyright &y& Elsevier]

Abstract: The thermal noise coupling with the displacement of the mirrors of a gravitational wave interferometric detector is a limit to its sensitivity in a range of frequencies from about 10Hz to few hundreds of Hz; fused silica proved to be a very suitable material to reduce this source of noise for the first generation of detectors. The future advanced detectors are planning to make use of fused silica mirrors and suspending elements in a monolithic arrangement: in these conditions, the main contribution to the thermal noise will come from the amorphous multilayered coating deposited on the mirrors. This paper is focused on the multiple advantages provided by the use of fused silica material in a present day interferometric detector; a new suspension for measurements of the acoustic attenuation in fused silica is presented together with the loss angle dependance on frequency and aspect ratio. Furthermore we report on the status of the art of the research activity on fused silica wires production and characterization and coating thermal noise accomplished by the Firenze–Urbino Virgo group. [Copyright &y& Elsevier]

Abstract: We have developed a multi-layer approach for the synthesis of water-dispersible superparamagnetic iron oxide nanoparticles for hyperthermia, magnetic resonance imaging (MRI) and drug delivery applications. In this approach, iron oxide core nanoparticles were obtained by precipitation of iron salts in the presence of ammonia and provided β-cyclodextrin and pluronic polymer (F127) coatings. This formulation (F127250) was highly water dispersible which allowed encapsulation of the anti-cancer drug(s) in β-cyclodextrin and pluronic polymer for sustained drug release. The F127250 formulation has exhibited superior hyperthermia effects over time under alternating magnetic field compared to pure magnetic nanoparticles (MNP) and β-cyclodextrin coated nanoparticles (CD200). Additionally, the improved MRI characteristics were also observed for the F127250 formulation in agar gel and in cisplatin resistant ovarian cancer cells (A12780CP) compared to MNP and CD200 formulations. Furthermore, the drug-loaded formulation of F127250 exhibited many folds of imaging contrast properties. Due to the internalization capacity of the F127250 formulation, its curcumin-loaded formulation (F127250-CUR) exhibited almost equivalent inhibition effects on A2780CP (ovarian), MDA-MB-231 (breast), and PC-3 (prostate) cancer cells even though curcumin release was only 40%. The improved therapeutic effects were verified by examining molecular effects using Western blotting and transmission electron microscopic (TEM) studies. F127250-CUR also exhibited haemocompatibility, suggesting a nanochemo-therapuetic agent for cancer therapy. [ABSTRACT FROM AUTHOR]

Abstract: The presence of internal stresses in organic coatings is a current phenomenon that can generate loss of adhesion, so that it must be taken into account to achieve long-term protection. In the case of external coatings used for corrosion protection of steel pipelines, three-layer systems are often applied. They are composed with an epoxy primer, an adhesive and a thick layer of polyethylene. Some spontaneous disbondment having been observed on these coatings after only several years in service, the presence of internal stresses has been suggested to explain this behaviour. This finite element study aims at estimating the internal stress generated during the application process to compare it with the values of adhesion measured. This comparison should allow concluding if this phenomenon is responsible for the loss of adhesion observed. Three models were successively developed to estimate correctly the stress induced, including a linear thermoelastic model and a thermoviscoelastic one, with entry parameters function of temperature. [ABSTRACT FROM AUTHOR]

Abstract: Multi-layer coating systems are the state of the art for painting of metal and plastic surfaces e.g. in the automotive industry. Utilizing such systems consisting of several specialized coating materials, a high adhesion and a good corrosion protection can be reached, along with good barrier properties, chemical and scratch resistance as well as appealing surface appearance. The interphase regions between single layers of such systems represent areas of a potential weakness, where a delamination and a premature coating degradation can start. To test in a short time the protective properties of the coating, a special hydrothermal cyclic loading test procedure was developed, which causes accelerated build-up of internal stress within the coating system. Using an electrochemical impedance spectroscopy with various optimized electrode geometries, it was possible to detect the early stages of coating degradation and to compare different coating systems. Internal stress measurements contributed additionally to a better understanding of the coating degradation. [ABSTRACT FROM AUTHOR]

Abstract: The tribological properties of the multi-layer PVD and CVD coatings deposited onto the Si3N4 nitride tool ceramics are compared in the paper in relation to the fundamental mechanical properties like hardness, adhesion. The inserts made from Si3N4 were multilayer coated in the PVD process with the TiN+multiTiAlSiN+TiN, TiN+TiAlSiN+TiN, and TiN+TiAlSiN+AlSiTiN coatings and in the CVD process with the TiC, Ti(C, N), Al2O3 and TiN. Additional investigations were carried out to compare coatings obtained in this way on inserts from various manufacturers offering the nitride tool ceramics with the CVD coatings based on the Al2O3 and TiN layers. Basing on the tribological test made with the “pin-on-disk” method in respect to the hardness and adhesion investigations the correlation was revealed between these two properties. Machining tests results and roughness tests results for the machined grey cast iron surface are also presented. The CVD coatings demonstrate high abrasion resistance in comparison with the PVD ones, whose adhesion to the nitride ceramics is low. [Copyright &y& Elsevier]

Abstract: Comprehensive structure and properties investigation results of the multi-layer, multi-component physical vapour deposition (PVD) and chemical vapour deposition (CVD) coatings developed on the Si3N4 nitride tool ceramics substrate are presented in the paper. The detailed results are presented of examinations carried out on the scanning and transmission electron microscopes, as well as of the mechanical properties and tribological tests of the investigated coatings. Examinations of the chemical compositions of the deposited coatings were also carried out using the X-ray energy dispersive spectrograph EDS, glow-discharge optical emission spectroscope GDOS, and using the X-ray diffractometer. Machining tests of the grey cast iron and nickel alloy were made to analyse in detail the investigated multi-edge cutting inserts. The inserts made from Si3N4 were coated in the PVD process with the TiN+multiTiAlSiN+TiN, TiN+TiAlSiN+TiN, TiN+TiAlSiN+AlSiTiN type multi-component coatings and in the CVD process with the coatings based on the combination of the TiC, TiN, Ti(C,N) and Al2O3 layers. [Copyright &y& Elsevier]

Abstract: Comprehensive structure and properties investigation results of the multilayer, multi-component PVD coatings developed on the Si3N4 nitride tool ceramics substrate are presented in the paper. The detailed results are presented of examinations carried out on the transmission and scanning electron microscopes, as well as of the mechanical properties and tribological tests of the investigated coatings. Examinations of the chemical compositions of the deposited coatings were also carried out using the X-ray energy dispersive spectrograph EDS, glow-discharge optical emission spectroscope GDOS, and using the X-ray diffractometer. The inserts made from Si3N4 were multilayer coated in the PVD process with the TiN, TiN+multiTiAlSiN+TiN, TiN+TiAlSiN+TiN, and TiN+TiAlSiN+AlSiTiN coatings. Additional investigations were carried out to compare coatings obtained in this way on inserts from various manufacturers offering the nitride tool ceramics with the CVD coatings based on the Al2O3 and TiN layers. Basing on the metallographic examinations results it was found out that the multilayer PVD and CVD coatings were uniformly put down onto the substrate and the particular layers adhere closely to each other. It was found out in the microhardness tests of the coatings that the TiN+multiTiAlSiN+TiN one has the highest hardness. It was demonstrated also that all CVD coatings are characterised by very good adhesion to the substrate compared to the PVD coatings. Results of the X-ray qualitative phase analysis confirm occurrences of phases coming from coatings and the substrate. Analyses of the chemical composition – EDS and GDOS confirm presence of both titanium, aluminium, silicon, nitrogen, and oxygen in the investigated coatings and of silicon and nitrogen in the investigated substrate. [Copyright &y& Elsevier]

• • A new ultrasonic inversion method is proposed to identify multiple parameters of an inhomogeneous multi-layer coating. • • Material-oriented regularization is developed to decouple material and equipment constraints. • • Least-squares-coupled cross-correlation algorithm based on URCAS is presented to realize multi-parameter inversion. • • A power-law frequency dependence of the attenuation of a dual-layer coating is accurately measured. • • The proposed upper bound of relative error ± r of inversed parameter could be used to assess the accuracy of NDE IPs. Aiming to determine the geometric and acoustic parameters of inhomogeneous multi-layer coatings, an ultrasonic pressure reflection coefficient amplitude spectrum (URCAS) is derived using a material-oriented regularization scheme, when wave propagates perpendicularly to the coating surface. Based on the derived theoretical URCAS, a new objective function combining least-squares and cross-correlation algorithm is developed to simultaneously identify the thickness, sound velocity, density, attenuation coefficient amplitude, and attenuation coefficient power-law of the multi-layer coating. Genetic algorithm with the constraint of total multi-layer coating thickness being known is presented to optimize the nonlinear objective function for obtaining global optimal solution. Ultrasonic experiments were implemented on a dual-layer coating specimen with coating1/coating2/substrate structure using a flat immersion transducer with a central frequency of 15 MHz. The inversed thicknesses, sound velocities, and densities of the dual-layer coating were in good agreement with those measured through other methods, with less than 8.1% errors. The inversed attenuation coefficients of the coating 1 and coating 2 were α (f) = 1.02e-2 × f 1.93 and α (f) = 4.62e-3 × f 1.97, respectively. The upper bounds of the relative errors + r of inverted parameters were all less than 0.061. The proposed ultrasonic inversion method could be used to quantitatively characterize the surface integrity of inhomogeneous multi-layer coatings. [ABSTRACT FROM AUTHOR]

Manufacturing thick electrodes for Li-ion batteries is a challenging task to fulfill, but leads to higher energy densities inside the cell. Water-based processing even adds an extra level of complexity to the procedure. The focus of this work is to implement a multi-layered coating in an industrially relevant process, to overcome issues in electrode integrity and to enable high electrochemical performance. LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811) was used as the active material to fabricate single- and multi-layered cathodes with areal capacities of 8.6 mA h cm−2. A detailed description of the manufacturing process is given to establish thick defect-free aqueous electrodes. Good inter-layer cohesion and adhesion to the current collector foil are achieved by multi-layering, as confirmed by optical analysis and peel testing. Furthermore, full cells were assembled and rate capability tests were performed. These tests show that by multi-layering, an increase in specific discharge capacity (e.g., 20.7% increase for C/10) can be established for all tested C-rates. [ABSTRACT FROM AUTHOR]

The spread of multidrug-resistant (MDR) bacterial infections has become a serious global threat. We introduce multi-layer coated gold nanoparticles (MLGNPs) delivering antisense oligonucleotides (ASOs) targeting the resistance gene of methicillin-resistant Staphylococcus aureus (MRSA), as a selective antimicrobial by restoring susceptibility. MLGNPs were prepared by multi-step surface immobilization of gold nanoparticles (GNPs) with polyethylenimine (PEI) and loaded with ASO targeting the mecA gene. The MLGNPs were shown to be efficiently internalized into various types of Gram-positive bacteria, including MRSA, Staphylococcus epidermidis , and Bacillus subtilis , which was superior to single-layer coated GNPs and free PEI polymer. The delivery of MLGNPs into MRSA resulted in up to 74% silencing of the mecA gene with high selectivity, in a dose-dependent manner. The treatment of MLGNPs to MRSA in the presence of oxacillin, a beta-lactam antibiotic, showed major suppression (~71%) of bacterial growth, due to the recovery of antibacterial sensitivity. Furthermore, the treatment of MLGNPs in a complex system showed preferential uptake into bacteria over mammalian cells, demonstrating the suitable characteristics of MLGNPs for selective delivery into bacteria. The current approach can be potentially applied for targeting various types of MDR bacterial infections by specific silencing of a resistance gene, as a combinatorial therapeutic used with conventional antibiotics. • Multi-layer coated nanoparticles delivering antisense oligonucleotides for bacterial delivery • Silencing of the resistance gene leads to antibiotic susceptibility of multidrug-resistant bacteria. • Applications of the multi-layer coated nanoparticles for targeted treatment of bacterial infections by combinatorial therapy [ABSTRACT FROM AUTHOR]