Characterization Of Materials Research Articles

Uranium measurements in the field using high-resolution cadmium zinc telluride detectors

A new generation of cadmium zinc telluride (CZT) detectors has become available and is being evaluated by the International Atomic Energy Agency (IAEA) for safeguards verifications in the field. The new CZT detector, model M400, is a room temperature spectrometer manufactured by H3D, Inc. The M400 demonstrates superior energy resolution, effective isotope identification capabilities, and convenient usability features when tested in a controlled laboratory environment. These characteristics define the M400 as a potential platform for IAEA field detection applications, which could become suitable for nuclear material characterization (e.g., enrichment verification) and nuclear safeguards missions. The capabilities of gamma spectrometry codes including Fixed energy, Response function Analysis with Multiple efficiencies (FRAM) from Los Alamos National Laboratory, CZT for Uranium (CZTU) from Lawrence Livermore National Laboratory, and Gamma Detector Response and Analysis Software (GADRAS) from Sandia National Laboratories were adapted for M400 spectra, and the performance of the codes has been validated. This was reported in a prior work. To further validate the performance of the high-energy resolution CZT detector and the isotopic analysis codes, a field measurement campaign consisting of uranium hexafluoride (UF6) cylinder measurements was conducted at a fuel fabrication facility. A total of 34 Type 30B cylinders containing UF6 were measured using three different M400 CZT detectors. Each detector was outfitted with a custom rectangular collimator and shield made out T-Flex®, a tungsten-impregnated polymer. Measurements were performed at three different locations of the cylinder, ensuring that the measurement geometry satisfied the infinite thickness criterion. The spectra from the M400 CZT were analyzed using the code General Enrichment Meter (GEM). For analyzing the gamma-ray spectra from UF6 cylinder, the GEM code is the appropriate tool since it relies only on the gamma-ray emissions from 235U and not from other isotopes. Results from the spectral analysis were compared with the known abundance of 235U in the cylinders, as well as with the International Target Values 2020 (ITV2020). The suitability of the different underlying techniques used by the various codes for UF6 analysis is discussed. The challenges of measuring UF6 contained in cylinders and mitigation strategies are highlighted.

A feasibility study on phase characterisation of nickel-based superalloys using ultrasound

The use of nickel-based superalloys, such as Inconel 718, Udimet 720Li and Waspaloy, is widespread across the engineering industry due to their superior mechanical properties at elevated temperatures and excellent resistance to creep and fatigue under harsh working conditions. The microstructure of these materials, such as the precipitates and grain sizes, strongly influence the materials’ performance. Currently, existing materials characterisation methods are time-consuming, costly and destructive, as well as only capable of taking measurements of surface or near-surface properties.This paper presents a novel ultrasonic technique for bulk materials characterisation of nickel-based superalloys, based on a spherical harmonic convolution theory which has been successfully used to quantify texture in various metals; it is applied here to study a nickel-based superalloy, with a specific focus on the phase changes when subject to thermal loading. The key parameter used to interpret phase information of a material is the zeroth spherical harmonic coefficient of ultrasonic wave velocities, V00, which corresponds to the average velocities across all directions in 3D space and is independent of crystallographic texture. Experimental investigation using samples of a representative material, Inconel 718, with contrasting microstructures, has shown a clear and quantifiable sensitivity of this coefficient to microstructural changes occurring within the material, and has thus laid the foundations for the development of a rapid phase characterisation technique for nickel-based superalloys using ultrasound.

Study of inorganic based anti-blocks as migration control of slip additive on surface polyethylene monolayer film

Slip migration must be controlled to maintain the performance and quality of flexible packaging. Inorganic based anti-block materials can be used to control the slip migration. This paper reported the effect of anti-block type on the inhibition of slip migration on polyethylene monolayer film. A series of formulations were made with three different anti-block additives, namely talc, natural silica, and synthetic silica, along with erucamide. The optical properties (haze) and friction properties (COF) were measured to assess the film characteristics as the development of slip migration in the presence of anti-block additives. Characterization of the anti-block material was conducted by SEM-EDX, slip additive type was examined by GC-MS, while the slip content on the surface was analysed by FTIR. The result showed that after seven days, synthetic silica anti-block gives COF up to 0.095, with the trace erucamide content on the film surface of 394 ppm, the lowest amongst other types of the anti-block used. The smaller particle size and higher silica content on synthetic silica anti-block resulted in better friction properties which act as a good barrier to limit a migration of erucamide onto the film surface.

Synthesis, electricaland structural characterization of a composite material based on powdered magnetite and high density polyethylene

Garzón Posada A.O., F.E. Fajardo Tolosa, D.A. Landínez Téllez, J. Roa-Rojas, G. Peña Rodríguez. Synthesis, electrical and structural characterization of a composite material based on powdered magnetite and high density polyethylene. Rev. Acad. Colomb. Cienc., 37 (1): 55-59, 2013. ISSN 0370-3908. This work describes the synthesis and characterization of a composite material based on magnetite filled HDPE, which is comrnonly known for its magnetic properties. Composites of this kind are used in different applica­tions such as magnetic and microwave absorption, transducers manufacturing, and biomedical applications like targeted drug delivery, organs tagging, etc. The samples were produced according to different volume ratios of magnetite and HDPE. The samples structure was analyzed through X-ray diffraction tests and the crystallinity degree was calculated. Then, the samples were electrically characterized through volume resistivity measure­ments. The results showed that for ratios less than the 20% of magnetite there is not a substantial reduction in the resistivity ofthe composite compared to the unfilled HDPE. For magnetite ratios above the 30% the com­posite shows a substantial reduction of six orders of magnitude in its electrical resistivity.

Morphological and structural analysis of ceramic materials composite by Kaolinite and Alumina

In this work, we report the preparation, structural and electrical characterization, morphological analysis and hardness measurements of ceramic materials composed of kaolinite Al2(Si2O5(OH)4 and alumina AL2O3. Samples were prepared from mixtures of precursor oxides starting with 100% alumina and increased the kaolinite concentration on steps of 10% up to complete 100% of kaolinite. The samples were sintered by the method of solid state reaction at temperatures of 1150, 1250 and 1350 °C. We found that the alumina samples are stable at the different temperatures of synthesis. The samples of kaolinite at 100% suffer a change phase depending on the sinterization temperature, noting that at 1350 °C yields 87% mullite and 13% cristobalite. The presence of quartz was only detected in samples with 100% kaolinite for sinterization temperatures of 1150 and 1250 °C. All samples with a mixture of alumina and kaolinite showed the presence of mullite, which is increased when the content of kaolínite is high or when the sinterization temperature is increased. This allows us to infer that the introduction of alumina optimizes the process of mullite formation hy their reaction with the SiO2 that remainder from the kaolinite. The sample with 100% alumina has a Mohs hardness of about 5, and this is increased with the content of kaolinite, until a Mohs hardness of about 6 to the sample with 100% kaolinite. The dielectric constant of these materials is around 27.82.

Characterization of Rock Material Through Point Load Test Index, Granulometry, and Dimensions of Specimens

Characterization of Rock Material Through Point Load Test Index, Granulometry, and Dimensions of Specimens

Effect of the synthesis route and Co Coverage on Co / Ti3C2Tx materials for the oxygen evolution reaction

Green hydrogen resulting from water electrolysis is a key component for the transition to a renewable energy economy. However, it's success highly depends on active and stable electrocatalysts for the oxygen evolution reaction (OER) which is the bottleneck reaction of water electrolysis. Herein we assess the OER performance of non-noble metal-based electrocatalysts comprising Co oxide/hydroxide and delaminated 2D transition metal carbide sheets, Ti3C2Tx MXene. The catalytically active sites are provided by Co oxide/hydroxide, while the MXene contributes exceptional electrical conductivity. Our comprehensive electrochemical evaluation of their OER performance reveals that the chemical functionalization of Co on MXene sheets outperforms the pure Co or MXene alone, as well as physically mixed materials, across all tested performance metrics. From the materials characterisation, the chemical functionalized Co/Ti3C2Tx materials exhibit increased formation of layered double hydroxide (LDH) Co(OH)2 structures compared to the pure Co and physically mixed materials which may result in the improved OER activity observed for these materials. These findings emphasize the potential of anchoring transition metal oxides/hydroxides on MXene as a superior OER electrocatalyst for advancing sustainable green hydrogen production.

Characterization of Building Materials and Decay Hazards of the Discovered Archaeological Structures at Tell El-Hiṣn Site, Heliopolis, Egypt

Characterization of Building Materials and Decay Hazards of the Discovered Archaeological Structures at Tell El-Hiṣn Site, Heliopolis, Egypt

Analysis of the thermal performances of uninsulated and bio-based insulated compressed earth blocks walls: from the material to the wall scale

The lively international debate on the future of the built environment has placed emphasis on the possibilities offered by bio and geo-based building materials. Among these, raw earth-based materials offer several advantages associated to their reusability and low embodied energy.Nowadays, several companies are basing their production lines on prefabricated raw earth products, as is the case of compressed earth blocks (from now on CEBs). CEBs are commercialized for the construction of massive vertical envelopes, characterized by a high thermal inertia. Nevertheless, in order to compete with conventional building materials, it is also necessary to guarantee a high thermal resistance.In this work, this issue was solved by the design and testing of full-scale uninsulated and bio-based thermal insulated CEB walls. In this way, the thermal performance of CEB walls can be increased to meet the high energy requirements currently adopted in European Countries. Furthermore, the choice of bio-based insulations represents the main novelty of the study, aimed at finding hygrothermal compatible solutions at a low environmental cost.More in detail, this work reports the results of the thermal and physical material characterization of CEBs and of two innovative bio-based thermal insulations (lime hemp and sugarcane bagasse panels), and compare them with measurements made on full-scale uninsulated and insulated CEB walls. For this purpose, the walls are tested inside a double-room climatic chamber where they are subjected to variable temperatures on their two faces, reproducing typical indoor and outdoor conditions during summer and winter conditions in a continental climate.Results show the enhancement of thermal performances of compressed earth blocks walls when thin layers of bio-based thermal insulations are added. The thermal resistance of weakly bio-based insulated CEB walls is found to be nine times (for the sugarcane bagasse insulated CEB wall) and four times (for the lime hemp insulated CEB wall) higher than that of uninsulated CEB walls. Moreover, the addition of the insulation layers enhances the time lag and the decrement factor values of CEBs walls.

Process Optimization of the Morphological Properties of Epoxy Resin Molding Compounds Using Response Surface Design.

An epoxy compound's polymer structure can be characterized by the glass transition temperature (Tg) which is often seen as the primary morphological characteristic. Determining the Tg after manufacturing thermoset-molded parts is an important objective in material characterization. To characterize quantitatively the dependence of Tg on the degree of cure, the DiBenedetto equation is usually used. Monitoring polymer network formation during molding processes is therefore one of the most challenging tasks in polymer processing and can be achieved using dielectric analysis (DEA). In this study, the morphological properties of an epoxy resin-based molding compounds (EMC) were optimized for the molding process using response surface analysis. Processing parameters such as curing temperature, curing time, and injection rate were investigated according to a DoE strategy and analyzed as the main factors affecting Tg as well as the degree of cure. A new method to measure the Tg at a certain degree of cure was developed based on warpage analysis. The degree of cure was determined inline via dielectric analysis (DEA) and offline using differential scanning calorimetry (DSC). The results were used as the response in the DoE models. The use of the DiBenedetto equation to refine the response characteristics for a wide range of process parameters has significantly improved the quality of response surface models based on the DoE approach.

Physics-Based Continuum Modeling for an Aqueous Rechargeable Zn/MnO2 Battery

Abstract This study introduces a framework for modeling the aqueous Zn/MnO2 rechargeable battery. A reaction system and a physics-based continuum model are proposed based on two reaction types, one involving insertion and the second related to dissolution and deposition of a solid reaction product. The model, fitted to empirical data, predicts voltage behavior and capacity limitations during cycling, identifying electrolytic zinc depletion as a limiting mechanism, depending on the original cell construction. The research suggests needs for further material characterization and reaction analysis, which will advance our understanding and facilitate the development of grid-scale energy storage solutions.

Evaluation of mesoporous silica particles as a support for lipase immobilization in biodiesel production: Enhanced ethyl ester synthesis from algal oil

The utilization of novel materials in the biofuel production domain has been regarded as a significant advancement in catalyst development. Incorporating lipases in biodiesel manufacturing is often viewed as a cost-restrictive phase since the expenses associated with recovering these catalysts can render market expectations unfeasible. Within this investigation, mesoporous silica (MPS) particles were assessed as a supporting medium for immobilizing commercial lipase, subsequent to their utilization in ethyl ester synthesis. Initially, the production of mesoporous silica was achieved through the co-precipitation technique at a consistent pH and was subsequently chosen as an immobilization support for the enzyme. The characterization of the biocatalyst support materials produced was performed using various analytical methods including X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and BET analysis. The Novozym 435 lipase was then immobilized within the matrices, followed by the transesterification process of algal oil derived from Nannochloropsis. The resulting biodiesel samples demonstrated compliance with commercial standards, exhibiting an ester conversion rate exceeding 94.8 %. Additionally, properties such as density (0.93 g cm−3) and viscosity (5.01 mm2 s−1) satisfied the specifications mandated by ASTM for biofuel application. Experimental planning techniques showed that increasing lipase loading and using temperatures between 38 and 48 °C resulted in higher conversion rates of ethyl esters. This confirms the effectiveness of the enzymatic catalyst in generating primary fatty acid esters, even with residual lipid feedstocks.

Thermal properties analysis and thermal cycling of HITEC molten salt with h-BN nanoparticles for CSP thermal energy storage applications.

Molten salts are the operational fluid for most concentrated solar power (CSP) systems, which has attracted more attention among the scientific community due to the augmentation of their properties with the doping of nanoparticles. Hexagonal boron nitride (h-BN) nanoparticles were dispersed in HITEC molten salt to create a novel nanofluid and evaluate the h-BN nanoparticles' influence on HITEC thermophysical properties. The influence of nanoparticle concentration (0.1, 0.5, and 1wt.%) of h-BN and HITEC was studied in this research. HITEC and nano-enhanced HITEC molten salt (NEHMS) were characterized using energy-dispersive X-ray spectroscopy (EDX), field emission scanning electron microscopy (FESEM), and Fourier transform infrared spectroscopy (FT-IR). Specific heat capacity, latent heat, and melting temperature were assessed using differential scanning calorimetry (DSC). The maximum working temperature was evaluated with thermogravimetric analysis (TGA). The ideal nanoparticle concentration is 0.1 wt.% h-BN, which results in a 27% increase in heat capacity, a 72% increase in latent heat, and a 7% enhancement in thermal stability. The thermal cycling stability test proved the stability of the enhanced thermophysical properties. The material characterization revealed that the samples with improved thermophysical properties have a homogeneous dispersion of nanoparticles with minor nanoparticle agglomeration. The system advisor model (SAM) simulation comparison of the optimum sample with solar salt and HITEC salt revealed that using the optimum sample increases CSP plant efficiency by 0.4% and reduces power costs by 0.13¢/kWh.

A high sensitivity planar electric–magnetic isolated sensor for full characterization of magneto-dielectric materials

Magneto-dielectric (MD) materials have received much attention due to their applications in design of high-performance antenna and microwave components. Usually, their permittivity and permeability are key parameters in design of these components. Unfortunately, full characterization of these parameters faces challenge of measurement coupling between permittivity and permeability. To address this issue, an electric and magnetic isolated sensor based on a planar resonance structure is proposed and verified. Several shorting pins are used to separate the electric and magnetic regions, which effectively reduces the measurement coupling between permittivity and permeability. These shorting pins form a magnetic cavity pins (MCP) structure. The resonance structure is used for permittivity measurement, and the MCP structure is designed for measuring permeability with enhanced sensitivity. Moreover, to further improve the quality factor, a metal patch and two 50 Ω chip resistors are integrated on the microstrip line. To extract the imaginary part, the quality factor calculated from S21 will be used. By integrating these techniques, the sensor developed in this paper provides possibility of full characterization of MD materials with high sensitivity. Moreover, the magnetic cavity provides more space than the original design, allowing measurement in the Ultra-Wideband (UWB) range possible. Two sensors are designed and fabricated for validating the sensitivity and accuracy. Several materials with different permittivity and permeability are measured. The extracted measurement values show high agreement with the reference values. The permeability errors for real and imaginary parts are smaller than 3% and 4.5%, respectively. And the permittivity errors are smaller than 2.6% and 6.4%.

PDF-5+: a comprehensive powder diffraction file™ for materials characterization

For more than 80 years, the scientific community has extensively used International Centre for Diffraction Data's (ICDD®) Powder Diffraction File (PDF®) for material characterization, including powder X-ray diffraction analysis. Historically, PDF was made available for two major material types: one for inorganic analysis and the other for organic analysis. In the early years of the PDF, this two-material approach was implemented due to limited computer capabilities. With Release 2024, ICDD provides a comprehensive database consisting of the entire PDF in one database called PDF-5+, comprised of more than one million entries (1,061,898). The PDF-5+ with a relational database (RDB) construct houses extensive chemical, physical, bibliographic, and crystallographic data, including atomic coordinates and raw data, enabling qualitative and quantitative phase analysis. This wealth of information in one database is advantageous for phase identification, materials characterization, and several data mining applications in materials science. A database of this size needs rigorous data curation and structural and chemical classifications to optimize pattern search/match and characterization methods. Each entry in the PDF has an editorially assigned quality mark. An editorial comment will describe the reason if an entry does not meet the top-quality mark. The editorial processes of ICDD's quality management system are unique in that they are ISO 9001:2015 certified. Among several classifications implemented in PDF-5+, subfiles (such as Bioactive, Pharmaceuticals, Minerals, etc.) directly impact the search/match in minimizing false positives. Scientists with specific field expertise continuously review these subfiles to maintain their quality. This paper describes the features of PDF with an emphasis on the newly released PDF-5+.

Insight into Fe-O-Bi electron migration channel in MIL-53(Fe)/Bi4O5I2 Z-scheme heterojunction for efficient photocatalytic decontamination

Building a heterojunction is a fascinating option to guarantee sufficient carrier separation and transfer efficiency, but the mechanism of charge migration at the heterojunction interface has not been thoroughly studied. Herein, MIL-53(Fe)/Bi4O5I2 photocatalyst with a Z-scheme heterojunction structure is constructed, which achieves efficient photocatalytic decontamination under solar light. Driven by the newly-built internal electric field (IEF), the formation of Fe-O-Bi electron migration channel allows for rapid separation and transfer of charge carriers at the heterojunction interface, confirmed by the material characterization and density functional theory (DFT) calculation. The narrower band gap and improved visible light response also contribute to the enhanced photocatalytic activity of composite materials. With levofloxacin as the target pollutant, the optimal MIL-53(Fe)/Bi4O5I2 achieves complete removal of pollutant within 150 min, the photocatalysis rate of which is ca. 4.4 and 26.0 times that of pure Bi4O5I2 and MIL-53(Fe), respectively. Simultaneously, the optimal composite material exhibits satisfactory photodegradation of seven fluoroquinolones, and the photocatalysis rates are as follows: lomefloxacin > ciprofloxacin > enrofloxacin > norfloxacin > pefloxacin > levofloxacin > marbofloxacin. DFT calculations reveal a positive relationship between degradation rate and Fukui index (ƒ0) of main carbon atoms in seven fluoroquinolones. This study sheds light on the existence of electron migration channels at Z-scheme heterojunction interface to ensure sufficient photoinduced carrier transfer, and reveals the influence of pollutant structure on photolysis rate.

Utilization of carbon-bonded magnesia refractory waste in MOC-based composites: Towards CO2-neutral building materials

In the steel industry, a large amount of diverse waste is generated, including carbon-bonded magnesia-rich waste originating from refractories. This study focused on the development and characterization of composite material based on magnesium oxychloride cement (MOC), with an emphasis on incorporating MgO–C-based refractory waste (CBMW) as a sustainable filler. To reach the best possible material properties, two different size fractions were applied in various ratios, completely replacing quartz sand. A comprehensive analysis of all composite material samples was conducted utilizing various analytical techniques, XRD, SEM, EDS or STA-MS. Mechanical properties such as compressive strength, flexural strength, and Young's modulus of elasticity were evaluated. Even though even the best sample did not surpass the mechanical properties for the reference, compressive strength 78.1 MPa was achieved, which is a more than sufficient value for most indoor applications.

Characterization of calibration solution certified reference material for polycyclic aromatic hydrocarbons by exact matching isotopic dilution mass spectrometry: a case study from the Brazilian Metrology Institute

Abstract Recertification is a common practice in National Metrology Institutes whenever advances are made in certified reference material (CRM) characterization procedures, which play a key role in metrological traceability. This article compares measurements of 16 priority polycyclic aromatic hydrocarbons (PAHs) in toluene by gas chromatography isotopic dilution mass spectrometry (IDMS) using either an calibration curve or the exact matching approach. The multi-point IDMS calibration curve was used on the original CRM certification and the exact matching approach was carried out on its recertification. The measurement uncertainties by exact matching approach (0.3%–1.0%) were approximately 5 times smaller than those obtained using the calibration curve (1.5%–4.4%) for all PAHs, reducing the uncertainty component due to characterization of PAH CRM. This new characterization study added reliability, increased accuracy and reduced the measurement uncertainty of the Inmetro CRM, with metrological traceability to the International System of Units. The exact-matching isotope dilution is an important technique to value assign organic compounds in CRMs, an action that consolidates the chemical metrology in the Brazilian Metrology Institute.

Unraveling the impact of initial choices and in-loop interventions on learning dynamics in autonomous scanning probe microscopy

The current focus in Autonomous Experimentation (AE) is on developing robust workflows to conduct the AE effectively. This entails the need for well-defined approaches to guide the AE process, including strategies for hyperparameter tuning and high-level human interventions within the workflow loop. This paper presents a comprehensive analysis of the influence of initial experimental conditions and in-loop interventions on the learning dynamics of Deep Kernel Learning (DKL) within the realm of AE in scanning probe microscopy. We explore the concept of the “seed effect,” where the initial experiment setup has a substantial impact on the subsequent learning trajectory. Additionally, we introduce an approach of the seed point interventions in AE allowing the operator to influence the exploration process. Using a dataset from Piezoresponse Force Microscopy on PbTiO3 thin films, we illustrate the impact of the “seed effect” and in-loop seed interventions on the effectiveness of DKL in predicting material properties. The study highlights the importance of initial choices and adaptive interventions in optimizing learning rates and enhancing the efficiency of automated material characterization. This work offers valuable insights into designing more robust and effective AE workflows in microscopy with potential applications across various characterization techniques.

Optoelectronic Material Characterization Platform using RF Topological Edge States

AbstractEfficient characterization of optoelectronic material properties represents a crucial step in the development of next‐generation infrared (IR) materials and devices. For the first time, a sensitive, contact‐free optoelectronic material characterization platform is demonstrated that exploits the unique properties of radio frequency (RF) topological edge states implemented in a topological microstrip waveguide. The topological device is compatible with standard printed circuit board (PCB) processes with no additional materials, stubs, or resonators. The waveguide and topological properties computationally are designed and then experimentally the results are validated with S‐parameter and near‐field measurements. Finally, as a proof of principle, the room temperature spectral response of a micron‐scale thick mid‐wave infrared (MWIR) mercury cadmium telluride (Hg0.70Cd0.30Te) is measured using the topological microstrip and a five‐fold and 20‐fold increase is demonstrated in response when compared to a plain microstrip and trivial bandgap device, respectively. These results open the door to straightforward, low‐cost characterization of optoelectronic films.