Test Material Research Articles

Application of Pulse Gas-Discharge Electroacoustic Transducer for Non-Destructive Testing

This paper presents the results of a gas-discharge electro acoustic transducer of two configurations, operating on the basis of a pulsed discharge in air at atmospheric pressure. The influence of the electrode configuration on the acoustic characteristics of the transducer is considered. It is shown that a change in the volume of the discharge chamber and the inter electrode gap have a significant effect on the radiation intensity of the transducer. The features that arise when using open and closed type electro acoustic transducers in flaw detection problems are revealed. It is shown that an open type gas-discharge electroacoustic transducer is a sufficiently powerful broadband source of the excitation signal and has prospects for use in non-destructive testing. A closed type gas-discharge electroacoustic transducer has advantages when testing materials with special requirements for surface cleanliness or the magnitude of the applied external electric field.

Energy efficiency in materials testing by reactive power – part 1: power recirculating method in wear testing

Abstract Reactive power is related to the type of power that does not consume energy but stores it. In the design of test machines, the utilization of this physical phenomenon would be very beneficial. Reactive power allows for the combination of power amplification with energy savings, making it an ideal principle for conducting long-term tests that involve high loads and prolonged energy consumption. This concept is illustrated in this work focusing test machines used in rotary testing procedures. Drive element pairs, which serve as component test objects, are primarily exposed to wear stress. These stressed element pairs are consequently integral parts of a tribological system. The underlying principles of power amplification and power feedback are explained from the perspectives of drive technology, systematic design, methodical design, and mechatronics.

Streamlining the Highly Reproducible Fabrication of Fibrous Biomedical Specimens toward Standardization and High Throughput.

Soft nano- and microfiber-based polymer scaffolds bear enormous potential for their use in cell culture and tissue engineering since they mimic natural collagen structures and may thus serve as biomimetic adhesive substrates. They have, however, so far been restricted to small-scale production in research labs with high batch-to-batch variation. They are commonly produced via electrospinning or melt electrowriting and their delicate nature poses obstacles in detachment, storage, and transportation. This study focuses on overcoming challenges in the high throughput production and practical handling, introducing new methods to reproducibly prepare such scaffolds suitable for quantitative cell culture applications. Attention is given to the seamless handling and transfer of samples without compromising structural integrity. Challenges in detaching fibers without damage as well as storage, and transport are addressed. Cell culture studies demonstrate the methodological advantages, emphasizing the potential for standardized testing and biological readouts of these delicate fiber materials. The developed methods are applicable across various electrospinning and melt electrowriting approaches and can essentially contribute to their utilization in laboratory research and commercial applications.

Comparative mosquitocidal and repellence activities of essential oil, nanoemulsion and main terpenes of Deverra tortuosa against Aedes albopictus with insights into the non-target effects

There is an urgent and renewed interest in searching for effective and green pesticides to control mosquitoes. In this framework, the essential oil (EO) of the plant Deverra tortuosa was hydrodistilled, and analysed using gas chromatography-flame ionisation detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Dillapiole (40.2%), elemicin (8.1%), and myristicin (6.3%), phenylpropanoids, and sabinene (4.3%) a common monoterpene, were found to be the major EO components. The oil nanoemulsion (ONE) was developed adopting a green protocol, and then characterised. The EO, ONE, and terpenes, particularly the phenylpropanoids possessed considerable mosquitocidal bioactivity against the Asian tiger mosquito, Aedes albopictus. A percentage of 100% larval mortality was recorded when insects were treated with a concentration of 40 μL/mL of ONE after 24 hours of treatment, while double of this concentration from EO and dillapiole was required to achieve the same activity. The LC50’s against larvae ranged between 7.6 and 60.7 μL/mL. For adults, LC50’s ranged between 6.4 and 50.9 μL/L. At sub-lethal concentrations (0.625-5.0 μL/cm2), EO materials significantly repelled Ae. albopictus, where a concentration of 5.0 μL/cm2 of EO and ONE provided 100% protection for up to180 min. As a proposed mechanism of action, the EO materials considerably inhibited the activity of acetylcholinesterase (AChE). The test materials were safe for the mosquitofish, Gambusia affinis, a common larvivorous fish, and Eisenia fetida earthworm. Test materials were also safe for the white albino rat in an oral bioassay at a limit dosage of 3500 mg/kg b.wt. The findings support the use of the EO, nanoemulsion, and phenylpropanoids of D. tortuosa as environmentally benign natural mosquitocodes to control Ae. albopictus.

Optimization of high speed bone drilling with automated osteonecrosis avoidance using an ANN-GA hybrid method

ABSTRACT Efficient high-speed bone drilling with an automated osteonecrosis avoidance strategy is a very fascinating task to the orthopaedic surgeons. Several drilling parameters such as drill diameter, speed, and feed rate can affect the performance of drilling in terms of generated temperature and thrust force. This research is conducted using a high-speed mini CNC machine to investigate bone drilling parameters’ impact on the outputs. Here, a piece of swine bone has been used for testing material and an automated cooling system based on proportional controller (P) was developed to prevent osteonecrosis. Further, a hybrid Artificial Neural Network-Genetic Algorithm (ANN-GA) model has been proposed based on the different experimental findings. ANN predicts output variables, and GA determines the optimal input drilling parameters by minimizing the ANN model of temperature and force. The simulation results revealed that drill diameter of 1.838 mm, speed of 17,880 rpm, and feed rate of 9.973 mm/min minimized the output temperature generated on swine bone. Similarly, diameter of 1.5 mm, speed of 16,582 rpm, and 10 mm/min feed rate helped to minimize the generated force during drilling. The proposed model has been validated by conducting new experiments based on these obtained optimal parameters.

Quantifying the Contribution and Mobility of In Situ-Produced Helium in He-Retentive Minerals: A Case Study of the Salla-Kuolajarvi Metasomatic Rocks (Russia)

An alternative approach to separating trapped and radiogenic helium, and assessing the mobility of the latter in He-retentive minerals implemented in the present work, has been developed on the basis of helium extraction patterns obtained via incremental heating of mineral samples. We used these data both to estimate helium mobility in concentrates of various ore minerals (pyrite, magnetite, and hematite) and to assess the contribution of in situ-produced 4He in the total helium budget. The rocks of uranium-ore and gold mineralization of the Salla-Kuolajarvi belt (northern Karelia, Fennoscandian Shield) were used as test materials for the new approach. The method allowed such parameters as diffusivity, activation energy, closure temperature, and the contribution of the trapped helium to be obtained for all samples. The latter was used for the correction of apparent U-Th-He bulk ages. The interpretation of the calculated values was performed taking into account the closure temperatures of the U-Th-He system, as well as the peculiarities of each individual sample.

Development of Articulate Storyline-Based Media for Momentum and Impulse Material in Grade X Senior High Schools, Indonesia

This study aims to develop an android application-based learning media that is literacy-oriented on Momentum and Impulse material and can be run on most devices owned by students. The creation goes through several stages in its formation. Through an application on a computer or laptop called Articulate Storyline, it is developed in such a way as to become a learning media that can be used in everyday learning. With the development model used is the ADDIE model. This model was chosen because it has research steps that are systematically arranged. The steps of the ADDIE research and development procedure consist of five stages, namely Analyze, Design, Develop, Implementation and Evaluation. Which is intended for teachers and students of State High School (SMAN) 2 Pare and State Islamic High School (MAN) Paser with supporting data for material and media validation tests. The results of the study produced 91% for the media validation test and 83% for the results of the material validation test and it can be said that the learning media is very suitable for use. While the test results for teachers and students at MAN Paser and also SMAN 2 Pare each showed 90% and 94% for teachers and 90% and 89% for students.

Analisis Yuridis terhadap Sengketa Putusan MK Nomor 90/PUU-XXI/2023 tentang Uji Materi terhadap Pasal 169 Huruf q Undang – Undang Nomor 7 Tahun 2017 tentang Pemilihan Umum

The Constitutional Court is a judicial institution in Indonesia which was established on August 13, 2003. The Constitutional Court has the authority regulated in article 24C of the 1945 Constitution and Law Number 24 of 2003 concerning the Constitutional Court which was later updated to Law Number 8 of 2011. The Constitutional Court has a principle in making a decision on the material test of the law against the Constitution, which applies to everyone, final, independent and impartial. The Constitutional Court's (MK) decision regarding the age limit for presidential and vice presidential candidates (presidential and vice presidential candidates) in Case Number 90/PUU-XXI/2023 continues to reap pros and cons. In the decision, the Constitutional Court granted part of the application that tested Article 169 letter q of Law Number 7 of 2017 concerning General Elections. This study aims to identify and analyze disputes over the Constitutional Court Decision Number 90/PUU-XXI/2023 concerning the material test of article 169 letter q of Law number 7 of 2017 concerning general elections in terms of juridical aspects. The research method used is a literature study of the Constitutional Court decision Number 90/PUU-XXI/2023 with a focus on normative legal analysis. The results of the study show that the Constitutional Court's decision Number 90/PUU-XXI/2023 is formally inconsistent with Law Number 49 of 2009 concerning Judicial Power and Constitutional Court Regulation No. 2/PMK/2021.

Biomechanical Analysis of Camellia oleifera Branches for Optimized Vibratory Harvesting

To investigate the biomechanical properties of Camellia oleifera branches under two loading speeds within a specific diameter range, three-point bending tests were conducted using a universal material–testing machine. The tests were performed at loading speeds of 10 mm/min and 20 mm/min on branches with diameters ranging from 5 mm to 40 mm. This study aims to provide insights into the design of a manipulator gripper used in a vibrating harvester for Camellia oleifera fruit. Four main varieties of Camellia oleifera were tested to determine their elastic modulus. The nonlinear least squares method, based on the hyperbolic tangent function, was employed to fit the bending load–deflection curves of the branches. This process constructed multi-parameter transcendental equations involving elastic modulus, diameter, and loading speed. Results indicated that the branches of four Camellia oleifera varieties exhibited significant differences in their biomechanical properties, with their modulus of elasticity ranging from 459.01 MPa to 983.33 MPa. This suggests variability in the bending performance among different varieties. For instance, Huaxin branches demonstrated the highest rigidity, while Huashuo branches were softer in general. For the proposed empirical fitting equations, when the fitting parameter k is 168 ± 20 and the parameter c is 3.102 ± 0.421, the bending load–deflection relationship of the branches can be predicted more accurately. This study provides a theoretical basis for enhancing the efficiency of mechanized vibratory picking of Camellia oleifera and optimising the design of the gripper.

Comparing numerical simulation methods for evaluating hysteretic response of self-centering shear walls reinforced with SMA-ECC under cyclic loading

Under the action of earthquake, the traditional shear wall structure has the problems of excessive residual deformation and macroscopic cracks. The SMA-ECC composite material formed by the combination of smart materials such as shape memory alloy (SMA) and high ductility engineered cementitious composite (ECC) not only has good energy dissipation capacity, but also can obtain superior self-centering ability and damage self-healing ability, thereby improving the seismic performance and durability of shear wall structures. In this paper, in order to explore the nonlinear behavior of the self-centering shear wall under earthquake action and accurately simulate it, ECC and SMA material tests are carried out to establish the uniaxial constitutive relationship of the material. Using OpenSees finite element analysis platform, considering the micro and macro perspectives, a variety of finite element models are established, namely layered shell model, fiber model and multi-vertical rod model. Combined with the low-cycle reciprocating loading test of shear walls, the numerical simulation results are compared with the experimental data. By considering the parameters such as yield load, peak load and simulation time, the feasibility, stability and calculation efficiency of these models are evaluated. The results show that among the three models, the model based on fiber element can capture well the hysteretic response of new materials, and simulate the hysteretic performance, pinch effect and stiffness degradation of various shear wall members. The simulated values and experimental values can be well matched. Compared with the microscopic model, the computational efficiency of the fiber model is greatly improved, and the model has good feasibility, accuracy and efficiency.This work provides a basis for further research on the optimization of design parameters of SMA-ECC shear wall.

Effects of Rhizobium Inoculation on Rhizosphere Soil Microbial Communities, Physicochemical Properties, and Enzyme Activities in Caucasian Clover Under Field Conditions

Excessive use of chemical fertilizers in agriculture has become a major global source of pollution, leading to issues such as soil compaction, reduced fertility, eutrophication of water bodies, and air pollution. To address these challenges, the application of biofertilizers, such as rhizobial inoculants, has gradually become an effective, low-cost, and sustainable solution. In this study, the variety Trifolium ambiguum Bieb. (Mengnong clover No. 1) was used as the test material, and two rhizobial strains (R1 and R2) were employed for field inoculation trials. In April 2022, Caucasian clover was planted in an experimental field at Inner Mongolia Agricultural University. Each plot measured 3 m × 4 m and was arranged in a completely randomized design with three replications. In the regreening stage of 2023, rhizobial inoculation treatments were applied, with a control group included for comparison. This research examined the effects of rhizobial inoculation on the growth indicators of Caucasian clover, soil physicochemical properties, soil enzyme activities, and soil microbial communities. The results showed that rhizobial treatment increased the plant height and yield of Caucasian clover, improved soil physicochemical properties and enzyme activities, and positively affected soil microbial diversity and abundance. These changes enhanced soil fertility and optimized microbial community structure, promoting plant growth. The inoculation effect of strain R1 was superior to R2. In conclusion, rhizobial inoculants R1 and R2 can serve as effective biofertilizers for agricultural production.

Continuity across languages, cultures, and stakeholders: Carrying plurilingual suitcases into classrooms

This study explores the creation and testing of teaching materials aimed at promoting plurilingual and intercultural education in Swiss secondary schools. The piloting of these materials, grouped into six thematic units, involved 207 students from ten classes in Eastern Switzerland, revealing a highly diversified linguistic spectrum including European and non-European languages. The feedback brought to light positive engagement on the part of the students, but also challenges. These included the teaching materials' perceived lack of relevance to the pupil's everyday life outside school, and the difficulty for teachers to fit these activities into their busy schedules. While teachers expressed enthusiasm for plurilingual didactics, they perceived practical limitations due to time constraints as a significant obstacle. However, teachers recognised the potential of these activities to inspire pupils to be creative and alleviate their apprehensions about unfamiliar languages and cultures. The information gathered from the initial testing phases offers valuable insights for refining these materials and aligning them with the practical needs of classroom teaching, presenting an essential guide for effective implementation in different educational contexts, with the aim of ensuring a certain regularity to experiences of plurilingual education.

Tensile testing of polymeric materials: a model-based approach to estimate the material strength without position sensor

Abstract Tensile testing probably represents the foremost important mechanical test that can performed on materials. This characterization has great relevance on polymeric materials, where the evaluation of the polymer goes beyond the pure chemical composition analysis. On the other hand, chemical labs are not always equipped with complete tensile machines due to space and budget constraints while often rely on much simpler machines usually provided with a dynamometer only. In this contest, the goal of the work is to provide a useful and effective method to estimate the stress–strain curve based only on force (and therefore the specimen stress) data. Of course, to recover the missing information (i.e. the sample elongation, and thus its strain) a suitable model of the tensile machine is needed to complement the dynamometer measures. Throughout the paper the steps to achieve such a model are described, together with an extensive experimental validation: firstly, we validated the method on metals which exhibit a well-defined behaviour. Then, we selected three different polymeric materials (polyvinyl alcohol, polydimethylsiloxane and natural rubber) in order to assess the performances of proposed approach in estimating their stress–strain characteristics. The obtained results confirmed the suitability and effectiveness of the proposed method in real-world applications.

A new type of modern refractory raw materials ― modified complex-phase tabular alumina

New directions in the application of tabular alumina are considered. Information is provided on the development in the field of creating a new type of raw material ‒ modified complex-phase tabular alumina. The results of testing of the new material in different lining zones of steel ladles are shown.

An Electrochemical Screening Reactor Kit for Rapid Optimization of Electrosynthesis Applications

Electrosynthetic processes powered by renewable energy present a viable solution to decarbonize chemical industry, while producing essential chemical products for modern society. However, replacing well‐established thermocatalytic methods with renewable‐powered electrosynthesis requires cost‐efficient and highly optimized systems. Current optimization of electrolysis conditions towards industrial applications involving scalable electrodes is time consuming highlighting the necessity for the development of electrochemical setups for aimed at rapid and material efficient testing. Thus, we introduce a 3D printed electrochemical screening reactor designed for rapid optimization of relevant electrochemical parameters, utilizing electrode and membrane materials comparable to those in scalable electrolyzers. The reactor comprises eight individual two‐compartment cells that can be operated simultaneously and independently. To evaluate the reactor’s ability to provide meaningful insights on scalable cell designs, trends were compared with data from conventional scalable systems for electrochemical hydrogenations (EChH), demonstrating fast and accurate parameter optimization with the screening reactor. A detailed description of the reactor design and construction data files using open‐source tool are provided, enabling easy modification for anyone. We believe this screening reactor will be a valuable tool for the scientific community, for facilitating the discovery of reactions with customized electrode designs and rapidly improving conditions in established large‐scale electrolyzers.

Preparation of polymer hollow microsphere filled epoxy resin-based syntactic foam material and its performance analysis

To explore sound-absorbing and flame-retardant materials that meet the requirements for double-shielded and double-insulated Faraday cages, polymethyl methacrylate (PMMA) microspheres were incorporated into epoxy resin-based syntactic foam materials for testing and analysis. The addition of PMMA microspheres was found to enhance the electrical, mechanical, sound-absorbing, and flame-retardant properties of the syntactic foam, providing a potential reference for applications in high-voltage hall shielding and sound absorption. Syntactic foams with four concentrations of PMMA microspheres (0%, 0.5%, 1%, and 2%) were prepared. High-voltage breakdown testing, impedance tube testing for sound absorption coefficient, cone calorimetry for flame-retardant performance, and tensile and bending tests were conducted. Results showed that as the concentration of PMMA microspheres increased, improvements were observed in the tensile, bending, flame-retardant, and sound absorption properties of the syntactic foams, while breakdown strength decreased. These findings provide valuable insights into the application of syntactic foam materials in double-insulation, double-shielded Faraday cages.

An Anechoic, High-Fidelity, Multidirectional Speech Corpus.

We currently lack speech testing materials faithful to broader aspects of real-world auditory scenes such as speech directivity and extended high frequency (EHF; > 8 kHz) content that have demonstrable effects on speech perception. Here, we describe the development of a multidirectional, high-fidelity speech corpus using multichannel anechoic recordings that can be used for future studies of speech perception in complex environments by diverse listeners. Fifteen male and 15 female talkers (21.3-60.5 years) recorded Bamford-Kowal-Bench (BKB) Standard Sentence Test lists, digits 0-10, and a 2.5-min unscripted narrative. Recordings were made in an anechoic chamber with 17 free-field condenser microphones spanning 0°-180° azimuth angle around the talker using a 48 kHz sampling rate. Recordings resulted in a large corpus containing four BKB lists, 10 digits, and narratives produced by 30 talkers, and an additional 17 BKB lists (21 total) produced by a subset of six talkers. The goal of this study was to create an anechoic, high-fidelity, multidirectional speech corpus using standard speech materials. More naturalistic narratives, useful for the creation of babble noise and speech maskers, were also recorded. A large group of 30 talkers permits testers to select speech materials based on talker characteristics relevant to a specific task. The resulting speech corpus allows for more diverse and precise speech recognition testing, including testing effects of speech directivity and EHF content. Recordings are publicly available.

Research on Testing Methods for the Modulus of Elasticity of Inorganic Binder-Strengthened Materials based on the Direct Strain Method

Abstract In order to obtain the elastic modulus of inorganic binder-stabilized materials based on the lateral method, firstly, by analyzing the constitutive model of the material’s elastic modulus, a testing system for the elastic modulus of inorganic binder-stabilized materials was constructed using pressure sensors, resistance strain gauges, and dynamic and static strain data testing systems. Secondly, based on the stability test of the strain gauges glued to the surface of the specimen, it is proposed that the zero drift of the strain gauges should be controlled within 0~6με within 6 minutes of the test load. Meanwhile, based on the experimental loading results, it is determined that the length of the strain gauge wire mesh used for modulus testing of inorganic binder-stabilised materials should be 30mm. Finally, elastic modulus testing of inorganic binder-stabilised materials was carried out on core samples drilled at Longxun highway in Guangdong Province. The modulus of elasticity of on-site drilled core specimens was determined by the test and the test results were at the same data level as those measured by the rigid ring method, indicating reliable analysis results. The experimental results show that the direct strain method with the elastic modulus testing system as the core can greatly reduce the test preparation time, ensure stable system operation and provide reliable test results.

Optimal Design of the Hole Shape of the Air Suction Porous Turntable and Analysis of Adsorption Characteristics of Flexible Blades

ABSTRACTTo improve the adsorption effect of air suction sorting equipment, in this study, flexible blades were used as test materials, and porous turntables with circular holes (A), rectangular holes (B), and rectangular‐circular holes (C) were designed. Fluent software was used to simulate and analyze the aerodynamic characteristics of the flow field at the porous turntable, and the blade falling adsorption bench test was built. Under the same test conditions, the adsorption blades of the porous turntable were photographed by a high‐speed camera. Based on the C‐hole turntable and the tuyere air pressure of 380 Pa, it is verified by a single‐factor test that the blade falling in the distance of the porous turntable, the rotating speed of the turntable, and the number of blades extending perpendicular to the direction of movement have a direct effect on the blade adsorption of the porous turntable. To obtain the optimum adsorption conditions for the bench test, an orthogonal test was used, and a certain number of leaves were used for the test while the adsorption efficiency was considered; it is found that when the distance from the porous turntable is 40 mm, the rotation speed of the turntable is 60 r/min and the number of transverse blades of the conveyor belt is 4, and 100% adsorption can be achieved. In summary, the research results and methods of this experiment can provide reference and guidance for the research group to carry out the follow‐up research and development of multi‐stage air suction sorting equipment.

Effect of GA3 Spraying on the Physiological and Biochemical Indexes of Aglaonema under Drought Treatment

GA3 is a common plant growth regulator used in production that can accelerate plant metabolism and significantly enhance the plant growth rate. We investigated the effects of exogenous GA3 on the physiological and biochemical indexes of Aglaonema under drought treatment. The effects of exogenous GA3 on the plant height, leaf blight rate, antioxidant enzyme activity, leaf pigment, and malondialdehyde content of Aglaonema were evaluated using Aglaonema ‘Red Ruyi’ as the test material and simulating natural drought treatment in nutrient soil pots. The spraying of exogenous GA3 significantly increased superoxide dismutase and peroxidase enzyme activities, promoted the accumulation of soluble sugars, reduced the accumulation of malondialdehyde, and slowed the decline of chlorophyll and carotenoids, which had good effects such as the reduction of the leaf wilting rate and increase in the plant height as well as the maintenance of the plant shape to maintain the ornamental appearance. The growth indexes such as plant height and wilting rate were mainly influenced by the changes of the leaf pigment and physiological and biochemical indexes of malondialdehyde.