Series Of Test Samples Research Articles

Rapid manufacture of sodium polyaluminate electrolyte ceramics for solid state batteries via direct ink writing

Solid-state electrolyte structures using sodium polyaluminate ceramics, have been fabricated for the first time using direct ink writing; a material extrusion-based additive manufacturing process. A series of test samples were prepared using a high solids loading (80 wt%; 51.2 vol%) ceramic paste formulations with suitable rheological characteristics for 3D printing. Following optimum densification via conventional sintering at 1600 °C for 30 min, the additively manufactured electrolyte test samples exhibited an ionic conductivity of σ = 0.14 ± 0.019 S·cm−1 at 300 °C and density of ρ = 3.1 ± 0.02 g·cm−3 (relative density of 95%). These results suggest that direct ink writing of sodium polyaluminates is a promising approach for electrolyte manufacture. Additionally, this approach shows great potential for manufacturing complete solid-state battery structures, through multi-material direct ink writing.

Preliminary Study on Characteristics of NC/HTPB-Based High-Energy Gun Propellants

This study mainly explored the characteristics of NC/HTPB-based high-energy gun propellants with RDX, CL-20 or TKX-50 by experimental method. Three series of test samples were prepared referring to the formulation of M1 single-base gun propellant (M1 SBP). The thermochemical characteristics, chemical stability, explosion heat, impact and friction sensitivities of prepared samples were determined by simultaneous differential scanning calorimetry–thermogravimetric analysis (STA DSC–TGA), vacuum stability tester (VST), bomb calorimeter (BC), BAM fallhammer and BAM friction tester, respectively, and compared with those of the reference sample M1. The experimental results indicated that the thermochemical characteristics of NC/HTPB-based high-energy gun propellants were similar to those of M1 SBP. The NC/HTPB-based high-energy gun propellants had good chemical stability and were superior to M1 SBP. The explosion heat of NC/HTPB-based high-energy gun propellants was close to and slightly larger than that of M1 SBP. In addition, the NC/HTPB-based high-energy gun propellants had lower impact and friction sensitivities than the M1 SBP. Therefore, the NC/HTPB-based high-energy gun propellants have the potential to replace the M1 SBP. The combustion performances of NC/HTPB-based high-energy gun propellants will be continuously studied and verified in the future.

Surface-enhanced shifted excitation Raman difference spectroscopy for trace detection of fentanyl in beverages.

In recognition of the misuse risks of fentanyl, there is an urgent need to develop a useful and rapid analytical method to detect and monitor the opioid drug. The surface-enhanced shifted excitation Raman difference spectroscopy (SE-SERDS) method has been demonstrated to suppress background interference and enhance Raman signals. In this study, the SE-SERDS method was used for trace detection of fentanyl in beverages. To prepare the simulated illegal drug-beverages, fentanyls were dissolved into distilled water or Mizone as a series of test samples. Based on our previous work, the surface-enhanced Raman spectroscopy detection was performed on the beverages containing fentanyl by the prepared AgNPs and the SE-SERDS spectra of test samples were collected by the dual-wavelength rapid excitation Raman difference spectroscopy system. In addition, the quantitative relationship between fentanyl concentrations and the Raman peaks was constructed by the Langmuir equation. The experimental results show that the limits of quantitation for fentanyl in distilled water and Mizone were 10 ng/mL and 200 ng/mL, respectively; the correlation coefficients for the nonlinear regression were as high as 0.9802 and 0.9794, respectively; and the relative standard deviation was less than 15%. Hence, the SE-SERDS method will be a promising method for the trace analyses of food safety and forensics.

The Measurement of Activator Concentration Using an X-Ray Fluorescence Method for Cr Ions in Al2O3 Crystals as an Example

Abstract—A method for measuring the concentration of Cr3+ ions is considered in ruby single crystals (Al2O3 : Cr3+) using X-ray fluorescence analysis. The laboratory energy dispersive spectrometer was calibrated using the external standard method for quantitative measurements. In constructing the calibration dependence, we used a series of test samples of ruby crystals in which the concentration of Cr3+ ions was determined from the spectra of the long-wavelength U absorption band of ruby with a maximum in the region of 550 nm. The linear dependence of the X-ray fluorescence intensity on the concentration of chromium ions was obtained, which indicates the absence of matrix effects in the studied range of Cr3+ concentrations (from 0.01 to 0.8 wt %). The possibility of using the method for measuring the concentration of other activators in dielectric ionic crystals is noted.

Characterization of pervious concrete using over burnt brick as coarse aggregate

In the search of alternate construction materials, over burnt brick aggregate has enrolled its appellation as a low cost sustainable alternate material. In the north-eastern part of India, especially in Tripura, the shortage of natural stone aggregate has opened up the field for over burnt brick aggregate to be used as an alternate pavement material. This study mainly focuses on the characterization of pervious concrete mixes produced with over burnt brick as coarse aggregate. Pervious concrete, in the recent era, has been considered as the emergent technology due to its prominence as an environmentally and hydrologically sustainable pavement system. In this paper, a series of test samples are produced using various design variables and then the mechanical strength and the pore properties of porous mixes are evaluated. Aggregate gradation, water-cement ratio and the percentage of fine aggregate are chosen as the design variables and their effect in the compressive strength, tensile strength, flexural strength, porosity, permeability, etc. are estimated. The statistical analysis is also carried out using the experimental test data and prediction equations are developed to estimate the porosity, permeability and the compressive strength of the pervious concrete mixes. The predicted equations fitted well and showed a very good agreement with the calculated results. These equations can be directly used for the selection of the mix proportion and the designing of pervious concrete mixes made with over burnt brick aggregate.

Experimental study of analogue vent erosion towards nozzle shapes

Volcanic vent shapes evolve over the course of an explosive eruption, as the high-pressure ejecta erode the solid conduit walls. The changing shape affects the fluid behavior of the expelled gases, potentially the plume rise, column collapse, and the type and amount of accidental debris ejected. Field observations of evolving vent shape are difficult or impossible. While the mechanics of this process have been studied numerically, almost no laboratory studies have examined these behaviors. Thus, a series of test samples was manufactured using 3D printing techniques, which were eroded using high-pressure compressed air. Four material combinations were considered, using stainless steel and alumina powders consolidated with binder concentrations of 16% and 38%. Material properties were evaluated using compression testing, while the erosion behavior was studied through high-speed visualization and pressure measurements with identical samples at constant inflow conditions. In all cases, the erosion showed an initial rapid erosion of the vent exit, followed by quasi-steady state conditions. All samples produced converging/diverging nozzle shapes, with exit areas increasing by 1.5 to 6 times, depending on the sample properties. Behavior correlated strongly with binder concentration, as low-binder materials had significant increases in nozzle area. When using high-density particles, these weaker samples disintegrated due to particle abrasion from higher kinetic energy impacts. The nozzle shapes produced supersonic exit conditions, with Mach numbers from 1.48 to 2.51 for the various samples. However, exit pressures were not balanced, suggesting that the optimum is not the isentropic, pressure-balanced shape previously postulated.

In-situ monitoring by thermal lens microscopy of a photocatalytic reduction process of hexavalent chromium

In this work, we describe the application of a micro-spatial thermal lens spectroscopy setup (thermal lens microscope, TLM) with coaxial counter-propagating pump and probe laser beams and an integrated passive optical Fabry-Perot to quantify the Cr-VI concentration in water during a photocatalytic reaction in-situ. A series of test samples was analyzed using the 1,5 diphenil carbazide colorimetric method. A calibration curve was obtained by plotting of the TLM signal as a function of the concentration of Cr(VI) in a range between 0 and 10 μg/L (1 μg/L = 1 ppb, part per billion), with a detection limit of 53 ng/L (1 ng/L = 1 ppt, part per trillion). A solution of 10 μg/L Cr(VI) in distillated water was placed into a cell in contact with an iron-incorporated titanium dioxide film, which was previously grown onto a 1 mm thick glass microscope slide by the sol-gel dip-coating technique. The TLM signal was registered as a function of the photocatalysis time measured from the beginning of the process, radiating the film with UV-violet light. The Cr(VI) concentration was determined with the calibration curve and after the first 50 minutes a reduction of 95 % of Cr(VI) was observed, being the chemical reaction kinetic described by a potential time decreasing function.

Spectroscopic Compton imaging of prompt gamma emission at the MeV energy range.

This work explores a novel tomographic approach to PGAA that is both quantitative and spatially resolved, adapted from a clinical "proton beam range finder" in which MeV gamma rays are imaged by coincidence measurements of Compton scattered gamma rays with multi-detector arrays. We performed preliminary measurements using a Compton camera made with CdZnTe detector arrays on a series of test samples with high-energy (> 1 MeV) gamma emission lines. 3D image reconstructions were performed on the 2.2 MeV peak from H. The image reconstruction methods were also evaluated using the emission data generated by Monte Carlo simulations under ideal conditions.

Multi-penalty regularization in learning theory

In this paper we establish the error estimates for multi-penalty regularization under the general smoothness assumption in the context of learning theory. One of the motivation for this work is to study the convergence analysis of two-parameter regularization theoretically in the manifold learning setting. In this spirit, we obtain the error bounds for the manifold learning problem using more general framework of multi-penalty regularization. We propose a new parameter choice rule “the balanced-discrepancy principle” and analyze the convergence of the scheme with the help of estimated error bounds. We show that multi-penalty regularization with the proposed parameter choice exhibits the convergence rates similar to single-penalty regularization. Finally on a series of test samples we demonstrate the superiority of multi-parameter regularization over single-penalty regularization.

Identification of the Elasticity and Damping Characteristics of a Fiberglass Based on a Study of Dying Flexural Vibrations of Test Samples

A procedure for identification of the elastic characteristics and amplitude dependences of the logarithmic vibration decrement of a fiberglass, upon its deformation along the warp and weft directions and in shear, from given elastic and damping characteristics of multilayer test samples is put forward. To identify the elastic characteristics of the fiberglass, a dynamic method based on comparison of experimental and calculated free frequencies of a test sample is used. The sought-for amplitude dependences are approximated by polynomials. For determination of their coefficients, it is proposed to use direct methods with minimization of a target function constructed by comparing the experimental and calculated logarithmic vibration decrements of the test sample. In order to accelerate the process of search, an algorithm of express run is used to find the amplitudes and logarithmic vibration decrements of the test sample for solving the direct problem. Examples of identification of the elastic and damping characteristics of the fiberglass by using data of physical experiments on different series of test samples are presented.

Theoretical-Experimental Method for Determining the Material Damping Properties Based on the Damped Flexural Vibrations of Test Samples

Theoretical-experimental method is proposed in this paper for determining the logarithmic decrement of vibrations based on the measurement of tip amplitude of the flat cantilever test samples during their damped vibrations at first resonance mode. Significant effect of external aerodynamic forces on logarithmic decrement is observed. Extensive theoretical and experimental studies were performed on the aerodynamic component of damping of oscillated flat strip plates. For the assessment of its contribution to overall damping of test samples during their free vibrations, large number of numerical experiments were carried out on two dimensional flow dynamics around the plate, in the light of which an approximated empirical formula is found. Present study is also covering the method to identify the elastic properties and amplitude dependencies of logarithmic decrement on deformation in accordance with the data of physical experiments performed with various series of test samples.

Development of the Structure of Road-Construction Materialswith the Use of Drilling Cuttings

<p>Oil based drilling cuttings after thermal treatment processed at 340 °С were used as mineral powder for creation of composite material. For a compounding of drilling cuttings the road asphalt of the BND 60/90 brand was used. Efficient activity of natural radio nuclides which made 25 ± 5 Bq/kg was identified. Element structure of drilling cuttings was identified with the usage the method of the X-ray phase analysis. Existence of the signal corresponding to the following connections was established: СаСО<sub>3</sub> – calcite, NaCl – halite, BaSO<sub>4</sub> – barite, CaMg(CO<sub>3</sub>)<sub>2</sub> – dolomite. Content of calcite makes 65% of masses, content of halite – 15% of masses, content of dolomite – 8% of masses, content of barite – 10% of masses. A small amount of оrganite (СаСО<sub>3</sub>), anhydrite (CaSO<sub>4</sub>) and quartz (SiO<sub>2</sub>) was discovered. Formation of series of test samples of composite material with the subsequent research of their physical and chemical and operational properties was done. The most optimum is the asphalt concrete mixture with the content of 7% of drilling cuttings as mineral powder. Physical and chemical characteristics of the made samples indicate compliance to qualifying standards. The received results allow recommending drilling cuttings after thermal treatment as a mineral additive at construction of highways of IV-V technical category. The use of oil based drilling cuttings as a mineral component of road-building coverings does not constitute ecological danger to the environment, thereby, it gives the chance to solve one of the urgent environmental problems of the region, i.e. the effective use of industrial wastes and environment protection.</p>

Study of Thermal Technical Properties of Lightweight Concrete with Utilization of Non Stationary Hot-Wire Method

This paper describes the results of research that was focused on the study of thermal insulation properties and behaviour of lightweight expanded clay aggregate concrete. During the research it was carried out a determination of the thermal conductivity on a series of test samples with different volume weight and different mechanical properties. Determination of the thermal conductivity coefficient at lightweight concrete is quite difficult due to high in homogeneousness of the tested material being result of high open structure. Stationary and non-stationary measurement methods were used to determine the thermal insulation properties, which were reviewed for their relevance to the application.

Production of fired construction brick from high sulfate-containing fly ash with boric acid addition

The increase of power plant capacity has led to the production of an increasing amount of fly ash that causes high environmental impact in Turkey. Some of the fly ash is utilized within the fired brick industry but high sulfate-containing fly ash creates severe problems during sintering of the fired brick. This study attempted to investigate the potential for converting high sulfate-containing fly ash into useful material for the construction industry by the addition of boric acid. The chemical and mineralogical composition of fly ash and clay were investigated. Boric acid (H(3)BO(3)) was added to fly ash-clay mixtures with up to 5 wt.%. Six different series of test samples were produced by uniaxial pressing. The samples were fired at the industrial clay-brick firing temperatures of 800, 900 and 1000 degrees C. The microstructures of the fired samples were investigated by scanning electron microscopy and some physical and mechanical properties were measured. It was concluded that the firing at conventional brick firing temperature of high sulfate fly ash without any addition of boric acid resulted in very weak strength bricks. The addition of boric acid and clay simultaneously to the high sulfate- containing fly ash brick dramatically increased the compressive strength of the samples at a firing temperature of 1000 degrees C by modifying the sintering behaviour of high sulfate fly ash.

Reuse of waste glass in building brick production

The main objective of this study was to investigate the effect of waste glass addition on the properties of fired clay brick. Milled waste glass was added into brick clay at a ratio of 0% (control sample), 2.5, 5 and 10%. Four different series of test samples were produced by extrusion pressing. Samples were fired at 850, 950 and 1050 degrees C. The microstructures of the fired samples were investigated by scanning electron microscopy. The compressive strength of the fired samples was significantly improved by the addition of waste glass. It was concluded that the amorphous nature of waste glass particles enhanced the sintering action and this led to better strength behaviour.

Practical evaluation of universal conditions for four-plex quantitative PCR

Multiplexing quantitative polymerase chain reaction (qPCR) is a powerful way to substantially increase the number of genes that can be analyzed, while also reducing sample requirements, time, and cost. However, little previous work has been done to show its feasibility for multiple gene targets. Here, we determined optimal conditions for four-color multiplex qPCR. On the basis of amplification curves, we first established that the concentration of probe-primers should be about tenfold lower than that for conventional qPCR. This condition was evaluated using four sets of probe-primers labeled with FAM, CAL Fluor Orange, TAMRA, and Quasar670, respectively. To simulate the condition that different genes have different levels of transcript abundance, a series of test samples was prepared by mixing a constant amount of two kinds of vector together with different amounts of two other vectors in a four-plex qPCR format. The PCR efficiency of the constant genes was minimally affected by the presence of the spiked vectors, and the slope factors of standard curves for the two spiked genes were sufficient for the accurate quantification. We demonstrated here that qPCR in a four-plexed format is feasible for cost-effective practical use through a combination of lower concentrations of probe-primers, an appropriate reagent, and a detection instrument.

Effects of electroplating on the mechanical properties of stereolithography and laser sintered parts

This paper provides a quantitative and qualitative assessment of the effects of electroplating on polymer parts made by stereolithography (SL) and laser sintering. A series of test samples were coated with copper and nickel with varying thickness. Thicker coatings (120 μm) were reproduced with a repeatability that should not adversely affect the tolerances with which such parts may be produced given the tolerances of the initial rapid prototyping processes themselves. Thinner coatings (20 μm) resulted in a smother surface finish than thicker coatings for SL parts, however the converse was true for laser‐sintered parts. Composite theory was used to predict that thicker coating would lead to higher Young's modulus in parts and this was shown to be true in physical tests although the practical values were lower than the predicted values especially for thicker coatings. Physical tests also confirmed that thicker coatings increased UTS and impact energy but had a minimal effect on the ductility of parts.

Adequacy and Inadequacy in the Metrology of Chemical Analysis

The adequacy (inadequacy) of samples to each other and reference materials to test samples is an important notion in the metrology of chemical analysis. However, the literature gives no strict definition for this notion. In this paper, it was proposed to determine adequacy based on the measure of inadequacy. For the case of two samples, the measure of inadequacy is the absolute value of the difference between the systematic errors of the results of analyses of the samples; it depends on the difference in the composition and properties of the samples. The measure of inadequacy of a standard reference material to a series of test samples is the maximum distance between the systematic error of the reference material and one of the quantiles of the systematic error distribution of the test samples Q(0.025); Q(0.975); the errors in this case are due to the composition and the properties of the test samples. The samples are considered adequate if the measure of inadequacy can be neglected compared to the normalized error of the analysis. Using the determination of total cholesterol in the blood serum of humans as an example, it was shown that the standard reference material in the analysis of samples of complex composition is often inadequate to test samples.

Iodine-assisted molecular beam epitaxy

Iodine was introduced into our solid source molecular beam epitaxy chamber during the growth of GaAs and AlGaAs layers and strained-layer InGaAs quantum wells. Photoluminescence spectra of these samples taken at 4.2 K were compared to spectra from a series of test samples which were grown in the absence of iodine flux. We have observed a general improvement of the material quality of AlGaAs layers grown at substrate temperatures around and below 600°C since the introduction of iodine into our chamber regardless of whether an iodine flux impinged on the substrate during the growth process or not. Strong excitonic peaks with full width at half maximum of only 8 meV were observed in 4.2 K photoluminescence spectra of undoped Al 0.2 Ga 0.8 As layers grown at substrate temperatures as low as 550°C using As 4 . The epitaxial layers grown since the introduction of iodine are the brightest Al 0.2 Ga 0.8 As samples that we have obtained from our molecular beam epitaxy system. These results suggest that the presence of iodine in a molecular beam epitaxy system can result in improved optical properties for AlGaAs. The 4.2 K photoluminescence spectra and secondary ion mass spectroscopy depth profiles also show that iodine preferentially removes Ga from AlGaAs layers during growth, resulting in layers with higher Al content.

What information can be obtained by RHEED applied on polycrystalline films?

In this paper, an analysis of reflection high-energy electron diffraction (RHEED) performed on polycrystalline films is presented. It is shown that it is possible to obtain qualitative and quantitative information about the crystallography of the deposit. Two series of test samples were used: (i) glass substrates recovered by Fe grains with a (200) fiber-like texture normal or inclined with respect to the surface normal, and (ii) the same films but with a (110) texture. These samples exhibit characteristic RHEED patterns. Using a simple model, it is possible to determine: (i) the texture of the film, (ii) the average angle of the texture axis with respect to the surface normal, and (iii) the angular width of the distribution of this angle about its average value.