Test Material Research Articles

A Measurement Approach for Characterizing Temperature-Related Emissivity Variability in High-Emissivity Materials

The effective knowledge of emissivity is pivotal to obtain reliable temperature measurements through non-contact techniques like pyrometry and thermal imaging. This is fundamental in high-temperature applications since material emissivity strongly depends on temperature conditions. Given the recent attention in high-temperature applications, especially for replacing fossil-fuel-dependent heating with greener solutions in energy-intensive processes, renewed interest in characterizing materials radiant properties rose. This work presents a measurement procedure for characterizing the total emissivity of high-emissivity materials exploiting microwaves for heating the test material. The procedure grounds on a sequential approach, using a reference material of known emissivity (e.g., high-emissivity coating, already characterized sample holder, etc.) to derive the target material total emissivity. Uncertainty analysis is performed to provide a metrological characterization of the approach. The procedure is validated on target materials of known emissivity, focusing on high-emissivity materials commonly employed in microwave heating processes. Results are compatible with reference literature and material datasheets, demonstrating the validity of the proposed approach.

Outbreak of Norovirus Infection in the Hematology Department of a Children's Multidisciplinary Hospital

Relevance. Noroviruses are currently considered the most common cause of sporadic cases and community-acquired outbreaks of acute gastroenteritis (AGE) worldwide [1]. However, outbreaks of healthcare-associated infections (HAI) are also often caused by norovirus etiology [2], including in the Russian Federation [3].Aim. Analysis of key aspects of prevention and anti-epidemic measures against norovirus infection (NVI) in the hematology department.Materials and methods. The following epidemiological research methods were used: descriptive (intensity, dynamics, spatial characteristics of the NVI outbreak); analytical – longitudinal cohort study of the epidemic process of HAI – assessment of hypotheses about the causes and conditions, risk factors and routes of transmission of norovirus among patients and caregivers in the oncohematology department of the children's multidisciplinary hospital.Results and discussion. An outbreak of acute norovirus gastroenteritis of an imported nature was identified in the oncohematology department of a children's multidisciplinary hospital in February 2023, an analysis of the spread of NVI was carried out: the presumed source and mechanism of transmission of norovirus infection was established; the chronology of the spread of norovirus among patients and their caregivers is shown, a list of anti-epidemic measures taken to stop the outbreak is presented, and the difficulties of verifying the epidemiological diagnosis of HAI are reflected (based on the efficiency of laboratory testing of material from patients).Conclusion. Based on the results of the activities carried out, recommendations were proposed for improving preventive and anti-epidemic measures for acute gastroenteritis (AGE) in children's oncohematology departments.

Structural reliability assessment of a historical reinforced concrete building using numerical analysis and NDT techniques

AbstractThis paper presents a case study of a methodology for assessing the structural reliability of an early reinforced concrete structure using a combination of primarily non‐destructive diagnostic and advanced numerical analysis methods. The case study examines the historical Csíky Gergely Theater in Kaposvár, Hungary, built in 1911. At that time, the design methodology and construction process were carried out using a relatively rudimentary standard framework. This study demonstrates that a multi‐phase assessment procedure integrating numerical analysis and primarily non‐destructive testing techniques can significantly reduce structural analysis uncertainty. This approach allows for an optimal selection of the reliability index (βtarget), even when deviating from design standards. Based on this modified reliability index and considering the diagnostic and material test results, the partial factors used for the assessment can be optimally adjusted, and in most cases reduced, compared to those in design codes for new structures. Consequently, the extent of structural interventions needed to increase the load‐bearing capacity can be minimized.

Microplastic Materials for Inhalation Studies: Preparation by Solvent Precipitation and Comprehensive Characterization.

Assessing the inhalation hazard of microplastics is important but necessitates sufficient quantity of microplastics that are representative and respirable (<4µm). Common plastics are not typically manufactured in such small sizes. Here, solvent precipitation is used to produce respirable test materials from thermoplastics polyurethane (TPU), polyamide (PA-6), polyethylene terephthalate (PET), and low-density polyethylene (LDPE). Complementary methods verified that the desired size range is achieved both in number metrics and in mass metrics. To assess if the test materials are representative of their original plastic, a range of molecular properties, particle properties, and impurities are characterized: chemical composition, molecular weight, crystallinity, molecular mobility, density, surface charge, surface reactivity, particle size in mass and number metrics, particle shape, endotoxin content, and solvent content. The test materials obtained by precipitation are compared to commercial granules as references, and to alternative test materials obtained by other synthesis routes from LDPE, TPU, PET, PA-6, polystyrene (PS), and polyvinylchloride (PVC). Charge and surface reactivity of the precipitated test materials are low. Due to storage in water, microbial contamination needed to be monitored. For PET, PA-6, and TPU, the test materials are considered as representative and fit for purpose, whereas the inherent hydrophobicity of LDPE imposed strong aggregation.

Comparative measurement of short-term fluoride release and inhibition of caries around restoration by ion releasing restorative materials: an in vitro study

The main objective of the current study is to compare short-term fluoride release of three ion releasing restorative materials and assess their inhibitory effect on secondary caries. Materials used in this study included, Self-adhesive hybrid composite (group A), Ion releasing flowable composite liner (group B), and alkasite restorative material (group C). Twenty-two discs were fabricated from each material for short-term fluoride release test, conducted on days 1, 7, and 14. For assessing secondary caries inhibition, sixty-six sound molar teeth were used and standardized class V cavities were prepared. Teeth were divided into three groups according to each material, followed by 800 cycles of thermocycling. Subsequently, teeth were immersed in a solution containing cariogenic bacteria for 30 days. After that, teeth were sectioned bucco-lingually and analyzed using a polarized light microscope to measure inhibition area, outer lesion depth, and extension. Data was statistically analyzed using different tests. The study results revealed a statistically significant differences in fluoride release existed among materials. Self-adhesive hybrid composite exhibited the highest fluoride release. Lesion extension and depth were statistically significantly greater next to Ion-releasing flowable composite liner. The inhibition areas next to the Self-adhesive hybrid composite were statistically significantly larger than the other two materials. In conclusion, all tested ion-releasing restorative materials displayed fluoride release and the potential to inhibit secondary caries formation. Self-adhesive hybrid composite demonstrated the highest fluoride-releasing potential and the greatest ability to inhibit secondary caries. Conversely, Ion-releasing flowable composite liner exhibited the least fluoride release with minimal secondary caries inhibition. Increasing fluoride release correlated with larger inhibition areas and reduced outer lesion depth and extension.

A High-Throughput Technique for Unidirectional Critical Current Density Testing of Solid Electrolyte Materials

Abstract Work on solid electrolytes for rechargeable lithium-based batteries is motivated by the potential benefits of lithium-metal anodes for a variety of applications, including electric vehicles. Dendrite formation has been the key challenge preventing commercialization of rechargeable lithium-metal batteries, so establishing, validating, and improving the dendrite resistance of electrolytes is a key enabler of progress in the field. Typical symmetric cycling tests of Li-Li cells introduce operational and theoretical limitations which compromise the data produced and the conclusions which can be drawn from such testing. A high-throughput technique for unidirectional critical current density testing is presented which has allowed the development of a solid electrolyte capable of withstanding current densities of at least 300 mA cm 2. The theoretical and empirical basis for this testing methodology is outlined, results are presented and analyzed, and best practices for critical current density testing of solid electrolyte materials are proposed.

The regulatory module MdCPCL-MdILR3L mediates the synthesis of ascorbic acid and anthocyanin in apple.

Apple (Malus domestica Borkh.) is one of the most economically valuable fruit crops globally and a key dietary source for various nutrients. However, the levels of ascorbic acid (AsA) and anthocyanin, essential micronutrients for human health, are extremely low in the pulp of commonly cultivated apple varieties. In the present study, the second-generation hybrid strain of Xinjiang red-fleshed apple ('Zihong No. 1' × 'Gala') was used as the test material. The results revealed that AsA content was significantly higher in red-fleshed apple pulp than in non-red-fleshed varieties, and the expression of MdGLDH, a key gene in the D-mannose/L-galactose pathway, correlated strongly with AsA levels. Using the promoter of MdGLDH as bait, an R3-type MYB transcription factor (TF), MdCPC-like, was identified through yeast one-hybrid screening. Further analysis revealed that the overexpression of MdCPCL increased the AsA and anthocyanin levels in both callus and fruits, whereas MdCPCL knockdown led to a reduction in their levels. Moreover, the interaction between MdCPCL and the bHLH TF MdILR3-like was confirmed, forming the MdCPCL-MdILR3L complex. This complex significantly enhanced the transcription of downstream target genes MdGLDH and MdANS, promoting the synthesis of AsA and anthocyanins. This study contributes to further enrich the anabolic pathways of AsA and anthocyanin in apples and provides a theoretical foundation for the quality breeding of red-fleshed apple varieties.

New Rat Model Mimicking Sacrocolpopexy for POP Treatment and Biomaterials Testing via Unilateral Presacral Suspension.

Pelvic organ prolapse (POP) impacts women's health and quality of life. Post-surgery complications can be severe. This study uses rat models to replicate sacrocolpopexy and test materials for pelvic support, verifying the 4-week postoperative mortality rate, the mechanical properties of the mesh tissue, and the collagen content. Twenty-one 12-week-old female Wistar rats were used. Eighteen rats were subjected to POP induction by cervical suction and constant traction. One week after prolapse modeling, 18 prolapsed rats underwent unilateral presacral suspension (UPS) surgery with polycaprolactone (PCL) scaffolds, decellularized porcine small intestinal submucosa (SIS) scaffolds, or polypropylene (PP) meshes (n = 6 each). UPS rats were compared with normal rats (n = 3). After 4 weeks, conditions and mortality were recorded. The rats were then euthanized for biomechanical testing and collagen analysis. Ultimate load (N) was defined as the highest load before the failure of the target sample. The UPS procedure requires 42.9 ± 4.5min with no complications or deaths over 4 weeks. SIS was the stiffest mesh (14.53 ± 0.86 N), followed by PP (8.43 ± 0.40 N), and PCL was the least stiff (0.66 ± 0.05 N). After 4 weeks, the ultimate load of the PCL complex increased to 1.71 ± 0.41 N (p = 0.0120), but showed no significant difference from parametrial fascia (1.25 ± 0.85 N) and uterosacral ligament (0.66 ± 0.41 N). The ultimate load of the SIS complex decreased to 5.99 ± 0.37 N, still higher than native tissue. The PP complex's ultimate load (10.02 ± 1.80 N) showed no significant difference from PP alone. The collagen ratio of the PCL complex (48.11 ± 9.88%) was closest to that of the uterosacral ligament (36.66 ± 11.64%), whereas SIS and PP complexes had significantly higher collagen ratios than USL. Unilateral presacral suspension mimics classical surgery for human POP in rats. First, this procedure can investigate the mechanical properties of pelvic floor tissues at the cellular level after correcting POP. Second, it can be used to validate new materials for the surgical treatment of POP, including but not limited to foreign body reactions with surrounding tissues, absorption time, etc. Third, it can be used to study the biological mechanisms of mesh exposure.

An Open-Source Algorithm for Correcting Stress Wave Dispersion in Split-Hopkinson Pressure Bar Experiments.

Stress wave dispersion can result in the loss or distortion of critical high-frequency data during high-strain-rate material tests or blast loading experiments. The purpose of this work is to demonstrate the benefits of correcting stress wave dispersion in split-Hopkinson pressure bar experiments under various testing situations. To do this, an innovative computational algorithm, SHPB_Processing.py, is created. Following the operational run through of SHPB_Processing.py's capabilities, it is used to process test data acquired from split-Hopkinson pressure bar tests on aluminium, sand and kaolin clay samples, under various testing conditions. When comparing dispersion corrected and simple time shifting data obtained from SHPB experiments, accounting for dispersion removes spurious oscillations and improves the inferred measurement at the front of the specimen. The precision of the stress and strain results gathered from its application emphasises its importance through the striking contrast between its application and omission. This has a significant impact on the validity, accuracy and quality of the results. As a result, in the future, this tool can be utilised for any strain rate testing situation with cylindrical bars that necessitates dispersion correction, confinement, or stress equilibrium analysis.

Evaluation of rewarding effects of nitazene analogs: results from conditioned place preference tests and in vivo microdialysis experiments in mice.

In illicit drug markets, the most recently expanding new synthetic opioid subclass is benzimidazoles, also known as nitazenes, which were originally developed as analgesics in the 1950s. The emergence of this classical, potent drug family has attracted extensive research interest in the field of forensic toxicology; however, information on their psychological and physical dependence is very limited. Herein, we evaluated the rewarding effects of four nitazene analogs using a battery of in vivo experiments, with a positive control drug (isotonitazene). The four test materials, metonitazene, etodesnitazene, metodesnitazene, and flunitazene, were administered to male C57BL/6J mice by i.p. administration at 0.5, 2, 20, and 20 mg/kg, respectively. In comprehensive behavioral observation tests, representative opioid-related physiological and behavioral states, including analgesia, stereotypic circling behavior, hyperlocomotion, and Straub tail response, were observed. A set of conditioned place preference tests revealed that all the four analogs induced palatability in mice. Furthermore, measurements of dopamine levels in the nucleus accumbens shell by in vivo microdialysis resulted in significant elevations in all test material-treated groups, suggesting that the nitazenes elicit the rewarding effect through a neural circuit originating from the μ-opioid receptor activation at the ventral tegmental area. Our findings add important data regarding the psychological dependence of nitazenes and highlight the abuse potential of these four materials and other prevailing nitazene analogs.

Investigation of the hypoglycemic bioactive components of Phyllanthi Fructus through biological assessment combined with ultrafiltration affinity mass spectrometry.

Phyllanthi Fructus (PF) is a tropical fruit with the potential to effectively reduce postprandial blood glucose. However, the lack of quantitative evaluation methods and comprehensive understanding of hypoglycemic active compounds has hindered the development and application of functional foods and dietary supplements derived from PF. In this study, based on the "mass reaction parallel line method", with acarbose as the control and PF extract as the test material, a biological evaluation method for PF hypoglycemic activity based on α-glucosidase inhibition was established for the first time. The in vitro and in vivo validation experiments showed that the coefficient (r) of correlation between the biological evaluation results and the AUC of rat postprandial blood glucose concentration was as high as 0.866, which confirmed the reliability of the evaluation method. The analysis of 20 batches of PF samples showed that the hypoglycemia potency of PF ranged from 2.66 to 8.39 U mg-1, with an average value of 4.00 U mg-1, and the standard deviation was 1.5. UF-LC-MS was used to identify 36 components of PF capable of binding to α-glucosidase. Molecular docking results showed that the binding energy was between -3.5 and -14.3 kJ mol-1. The hypoglycemic activity of 17 available control products was tested, and 8 inhibitors were found, including hyperoside, gallic acid, and corilagin. Dose-effect analysis suggested that flavonoids and polyphenols with a phenolic hydroxyl structure could inhibit α-glucosidase. In short, this study provides a basis for the development of PF hypoglycemic functional foods.

Microplastics versus natural mineral particles. How to create and test them while maintaining environmental relevance

Whether microplastics cause different effects than inert natural particles, and how to create relevant testing materials, are key questions in microplastics research. We prepared Environmentally Relevant Microplastic (ERMP) and Mineral Microparticle (ERMS) mixtures with similar levels of polydispersity and tested their 28-day chronic effects on the reproduction and growth of L. variegatus at two different organic matter (OM) contents (average and enriched). Additionally L. variegatus was exposed to ERMP and ERMS to study the particle egestion for 14 days. We observed no differences in growth or reproduction between ERMP and ERMS at particle concentrations of up to 10% (v/v). In contrast, organisms exposed to enriched OM content increased their growth with 30% and increased reproduction with 20%. For ERMP with an enriched OM content, reproduction was reduced with an effect threshold EC50 of 13.68 ± 5.54% (v/v). After 14 days of exposure to 5% ERMP, the egestion of faecal pellets was higher compared to exposure to 5% ERMS, suggesting that in order to acquire the same amount of nutrition, L. variegatus is spending more energy. With this study, we demonstrate that refinements in the manufacturing of environmentally diverse particle mixtures can contribute to a more realistic testing of particle effects.

Management and quality control of construction materials standards, techniques, and challenges

Construction materials are crucial for the safety and longevity of structures, as they must withstand environmental conditions and be durable. Adherence to stringent standards and regulations is essential for materials like concrete, steel, wood, bricks, and composites. Common defects include manufacturing flaws, storage issues, non-compliance with standards, and variability in quality. To minimize quality problems, rigorous control techniques like material testing, visual inspections, performance testing, and certifications are applied. Proper finishing enhances aesthetics, durability, and performance, while surface preparation, installation, and maintenance are critical for plumbing and electrical systems.

DEVELOPMENT OF LEARNING EVALUATION TEST ON WORK AND ENERGY MATERIALS FOR GRADE VIII SMP

Learning evaluation is process to get information to know learning acceptable or not to students. This research aims to develop evaluation questions form multiple choices on work and energy material theoretically and empirically for grade VIII SMP. Development model used ADDIE, consists of stages : Analyze, Design, Development, Implementation, Evaliation. Theoretical validity test obtained from assesment evaluation test from material experts, media experts and practitioners from science teachers. Empirical validity testing obtained from analyzing data from results of testing evaluation test on students includes validity, reliability, level of difficulty, differentiability of questions. Results from validator got score 99,3 % and in very good criteria. Question validity test results 65% the questions valid and 35% the questions invalid. Question reliability test results a calculated r value of 0.774 and in high category. Difficulty level test results of the questions were 20%, 40%, 40% with categories difficult, medium and easy. Different power test results of the questions each received a score of 25% with the criteria very good, good, fair and low. Thus, the evaluation test of work and energy material are worthy of being tested on class VIII students.

Qualitative Assessment of a Construction Building

A construction building's structural integrity, material quality, workmanship, and conformity to design specifications were all assessed qualitatively. Potential problems like cracks, corrosion, or subpar construction techniques were found during the examination through visual inspections, material testing, and documentation analysis. Guidelines for upkeep, fixes, or structural improvements were offered to guarantee the building's longevity, security, and adherence to rules. The evaluation sought to improve the building's durability, functionality, and occupant safety while correcting any flaws to preserve structural integrity.

Development of Android-Based Interactive Learning Media on Computer Assembly Material with the ADDIE Model Approach

This study raises the title of the development of android-based interactive learning media on computer assembly material at SMK Negeri 1 Lolayan. Based on the observations and interviews, several problems were found in learning computer assembly material, including teachers still using PowerPoint learning media that is only text-based. During the practicum, one of the computers used was damaged. This is due to limited knowledge and inadequate facilities, resulting in teachers' lack of innovation and creativity in developing learning media, which makes it difficult for students to understand the material. This study aims to develop android-based interactive learning media on Computer Assembly material for class X TKJ students at SMK Negeri 1 Lolayan and test the feasibility of interactive learning media through material and media expert feasibility tests and determine the practicality of learning media through respondent trials (students/users). The research method used is Research and Development (R&amp;D) with the ADDIE development model (Analyze, Design, Development, Implementation, Evaluation). The results of this study were obtained from feasibility testing by material experts, who obtained an average value of ‘138’ with the criteria ‘Very Feasible.’ The results of feasibility testing by media experts obtained an average value of ‘120’ with the criteria ‘very Feasible,’ and the results of testing student response responses obtained an average value of ‘101’ with the criteria ‘Very Feasible’. The results showed that Android-based interactive learning media is feasible to use as an alternative to learning computer assembly

Pengaruh Model Think Pair Share (TPS) Berbantuan Media Tangsapan Terhadap Hasil Belajar Siswa Materi Saruan Panjang Kelas II SD Negeri 19 Merawang

This research was motivated by the low learning outcomes of students in long-unit material. The causal factors are that students have difficulty understanding the concept of units of length, teachers rarely apply learning models, and the media itself is underutilized. The aim of this research is to determine the efficacy of the Think Pair Share (TPS) model in facilitating the acquisition of class II long unit material at SD Negeri 19 Merawang through the use of tangsapan media. Quantitative research uses a one-group pre-posttest design and a pre-experimental approach is used. Second grade students at SD Negeri 19 Merawang were selected for this research using a saturated sampling method. Data were analyzed using paired samples t-test for hypothesis testing and Shapiro-Wilk normality test. According to the data, the unit length material test has quite a large impact on pre-test and post-test activities. The results of the pretest normality test (0.079 &gt; 0.05) and posttest normality test (0.203 &gt; 0.05) show that the data follows a normal distribution. This proves that H0 is wrong and Ha is correct, the hypothesis test results are 0.00 &lt; 0.05. Research data at SD Negeri 19 Merawang shows that the Think Pair Share (TPS) approach combined with the help of responsiveness has an effect on student learning outcomes in length unit material.

Стабильность геометрии рельсовой колеи на переходных участках

A study of the quality and heterogeneity of ballast compaction in the transverse (along the sleeper) direction as a reason for the decrease in the stability of the track gauge geometry, and consideration of design and technological solutions for transition sections in order to increase the stability of the track gauge geometry and prevent an intensification of the growth in the number of track disorders. Purpose: transition sections. Methods: stamp testing of ballast layer material, statistical data analysis. Results: the results of measuring the deformation modulus of the sleeper base, studying the non-uniform elasticity, assessing the quality and homogeneity of the compaction of the sleeper base for various designs of railway tracks are presented, and design and technological solutions for transition sections are considered. Practical importance: the article presents design and technological solutions for transition sections aimed at reducing the period of stabilization of the ballast layer of transition sections; increasing the period of normal operation, taking into account the current dynamic loads arising due to the presence of joints, dynamic irregularities, non-uniform elasticity of the railway track, non-uniform compaction of the ballast prism of transition sections; ensuring the uniform elasticity of the ballast layer of transition sections.

Shear Bond Strength of Orthodontic Stainless Steel Bracket in Bovine Teeth Submitted to Bleaching Agents

The purpose of this in vitro study was to determine the influence of bleaching agents in the shear bond strength of orthodontic stainless steel bracket. The samples were composed by 90 bovine lower central incisors, which were divided into three groups named G1 (not submitted to bleaching), G2 (bleached with carbamide peroxide at 16%-Whiteness HP - FGM ®) and G3 (bleached with hydrogen peroxide at 35%-Whiteness HP, FGM ®). The teeth were stored in distilled water at a temperature of 37oC for 24 hours and 30 days was expected for the bonding of brackets Gemini 3M (3M - Unitek ®), after a wait period of 30 days the brackets were placed to all groups of samples, applied with the composite Transbond XT (3M/ESPE®). The shear bond test was performed in material testing machine EMIC DL 2000, carried under a deformation speed of 0.5 mm / min. The G1 presented an average strength of 6,05 (±3,47) MPa, while the G2 presented an average resistance of 2,52 (±1,69) MPa, and the G3 demonstrated 1,58 (±1,17) MPa. The results concluded that the dental bleaching induced, in the experimental model used, significant reduction of shear strength of brackets bonded to dental elements subjected to both in-home and in-clinic bleaching. These findings suggest that adherence of the resin used in the placement of the brackets was damaged by bleaching. Therefore, the most affected in the analysis of shear bond strength was first the in-clinic bleaching, followed by in-home bleaching and at last the control group and the greater the concentration of bleach is less shear strength. So it is suggested to perform the bleaching treatment after orthodontic treatment.

Impact compressive properties of polyurethane foams with 3D continuous fibre reinforcement

Flexible and rigid polyurethane foams are used in applications subjected to impact loads. Integrating a three-dimensional, continuous fibre reinforcement meets high requirements for stiffness and strength. A fundamental comparison of the impact compressive properties was carried out for contributing to a reasonable choice between these variants. A rigid and flexible foam with a bulk density of 85 kg/m3 each was investigated with and without reinforcement by a warp-knitted spacer fabric. The material testing was conducted using a drop weight tester in accordance with a German standard. Three impacts are applied by a hammer with a flat surface larger than the area of the sample plate. Different impact energies were investigated and the deformation behaviour was analysed using a high-speed camera. Much higher energy absorptions at low deformations were found with rigid foam. Peak stresses and decelerations were lower with flexible foam if the load did not densify the material. Reinforcing the foams leads to an anisotropic deformation and improves the impact compressive properties, especially in the case of the flexible variant. The four materials analysed had a similar rebound and largely maintained their performance when subjected to the repeated impact load.