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Ball screws have been receiving increasing attention in the aerospace and military industry for their high reliability and high positioning accuracy. Under such extreme working conditions, ball screws are required to bear heavy loads in a short time, where they are mainly subject to fatigue elastic failure mode. Traditional reliability modeling methods based on the fatigue pitting failure mode are not suitable any more. However, reliability based on fatigue elastic failure in ball screws has not been investigated yet. To this end, we first established a degradation mechanism model for the fatigue elastic of ball screws. Subsequently, we proposed the degradation reliability model for ball screws, along with a novel Expectation Maximization method for parameter estimation. Additionally, we proposed a novel test method for the fatigue elastic life for ball screws utilizing a designed test bench. The mean curve for the degradation model almost exhibited a relative error less than 5%, confirming the validity of the proposed model. Lastly, we conducted a sensitivity analysis of structural parameters on fatigue elasticity, finding that the helix angle significantly influences the rated elastic life, while the ball diameter has a minimal effect. These findings contribute valuable insights for reliability evaluation and reliability design for ball screws under extreme working conditions. [ABSTRACT FROM AUTHOR]

Falls pose a significant threat to human health and safety. Accurately assessing the protective effectiveness of fall protection products can significantly reduce the occurrence of fall accidents. This paper systematically reviews the types and risk factors of human falls and then discusses the current research status and future prospects of various test methods for human fall protection. A literature search was conducted in databases such as Web of Science, Google Scholar, and Scopus. This study focuses on experimental methods for human fall testing, simulation model experiments, and finite element simulations, providing an outlook on future development trends. In the discussion of three different fall testing methods, research indicates that human fall simulation testing faces limitations such as ethical concerns and safety issues. Although simulation experiments allow for multiple tests in a short period, the complexity and accuracy of the models may affect the reliability of the results. By integrating more experimental data, optimizing the design of human models, and incorporating finite element simulation technology, the scope of testing applications can be expanded, thereby improving the effectiveness of protective product designs. In conclusion, future research on fall protection testing methods should aim to establish unified international standards, which will enhance consistency and repeatability in testing, facilitating better comparison and evaluation of the effectiveness of various protective measures. Furthermore, the integration of more experimental data with real-world scenarios, the optimization of human models and test environments, and the promotion of finite element simulation technology will be crucial in enhancing the precision of protective assessments. [ABSTRACT FROM AUTHOR]

The quality of air intake significantly impacts the overall performance of gas turbines. A new high-precision testing method for the air intake quality assurance system of gas turbines has been proposed, and the influence of typical intake conditions on the system was studied through this testing method. The research results indicate a positive correlation between filtration efficiency and particle size. Atmospheric temperature, particle concentration, filter differential pressure, and atmospheric humidity all affect filtration efficiency, with their influence decreasing in that order. Additionally, this paper presents a performance prediction model based on the LSTM neural network. The calculation results show that the errors of the filter pressure loss and filtration efficiency model test set are both less than 3%, reflecting the characteristics of pressure loss and efficiency well. The research results have significant engineering application value and provide experimental basis for establishing technical standards and high-precision detection systems for air quality assurance in gas turbines. [ABSTRACT FROM AUTHOR]

Copyright of Automotive Engineer (1674-6546) is the property of Auto Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The power transformer is one of the most important parts of a power system. The transformer oil in a transformer not only increases its insulation strength, but also helps its cooling. Cellulose particles are one of the main factors affecting the breakdown characteristics of transformer oil, and the withstand voltage test can effectively detect the quality of transformer oil. Therefore, the withstand voltage test on transformer oil with different cellulose particle content levels in the laboratory can determine the breakdown characteristics of transformer oil and the method of improving the insulation strength of power transformers. However, there is lack of a set of effective preparation and test methods of transformer oil for laboratory use in the industry. Based on national standards and engineering practice, this paper puts forward a method of preparing transformer oil with different cellulose particle content levels in the laboratory and a method of the withstand voltage test on transformer oil in the laboratory, which can improve the efficiency and the scientificity of such experiments. [ABSTRACT FROM AUTHOR]

The difference on inhibitory effects of bioflavonoids inhibiting XOD activity assayed by varying test methods cause of us to be further in consideration. The reported test method creating a micro‐environment surrounding XOD in the absence of ⋅O2−, which is seemly different from the assay in vivo. So, the vitro test method for assaying XOD activity is necessary to be improved for selection of potential inhibitors in the presence of ⋅O2−. The inhibitory results demonstrated that bioflavonoids of MY, DMY, QUE and LUT are capable to be on effective IC50 values, but others are not. As well, their resulting inhibitions determined by the improved test method are much less than that reported in the literature, indicating that their chemical affinities with XOD become weaker. Moreover, DMY assayed on the inhibitions of XOD in the improved test method performs to be a better inhibitor, as compared to the assay of the reported test methods. Abasing on the transformation of DMY into MY in the presence of ⋅O2−, the good inhibition of DMY on XOD activity can be explained by the synergistic effect of MY. [ABSTRACT FROM AUTHOR]

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Fiber Inspection / Zhongguo Xian-Jian is the property of China Fiber Inspection and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Composting offers a solid waste management alternative to landfilling resulting in soil amendment products with fertilization and moisture retention benefits and collateral methane reduction by diverting organic wastes from anaerobic landfill environments. An increasing array of materials and products are marketed as compostable, though only a limited range of these are covered by certification schemes. Greater accessibility and deeper understanding of compostability testing is needed to promote meaningful evaluation of the viability and optimal conditions for composting wider ranges of materials. This article describes various critical aspects of laboratory-scale methodology that can be optimized for more consistent, accurate, and efficient testing. While most of the reviewed studies are based on standardized international test methods, modifications to vessel design, medium, control systems, and evaluation show promise. Learnings are also drawn from biodegradation tests using soil and aqueous media. Particular consideration is given to evaluating compostability of textiles, including nonwovens, which today are primarily disposed of in landfills yet have the potential to supplement organic carbon in compost mixtures with nitrogen rich food waste. Furthermore, biodegradation properties of both natural and man-made textile fibers have received growing attention in recent years. Fiber fragments found in oceans and the surge of disposable face coverings used during the COVID-19 pandemic have been widely covered in the mainstream media, highlighting the importance of understanding biodegradation properties for textiles. This review consolidates and organizes diverse and essential procedural details reported in various standards and studies with the goal of encouraging and guiding successful implementation of compostability testing more broadly in laboratories. Certain gaps in test methodologies are identified to help focus future research. Reliable, accessible testing is crucial to expand the beneficial impacts of composting in waste management. [ABSTRACT FROM AUTHOR]

Electromagnetic disturbance is an effective means of observing earthquake precursors. As one kind of key device for capturing electromagnetic disturbances, induction magnetometers are widely used with the characteristics of high sensitivity, large dynamic range and wide frequency band. However, various instruments have different frequency bands, inconsistent observation frequency bands，and different usage fields. There are few instruments that meet the needs of observing low-frequency electromagnetic disturbances for seismic stations. In this paper, an observation system for earthquake low-frequency electromagnetic disturbance monitor is composed of integrating the self-developed inductive magnetic sensors and data acquisition system. Firstly, the system composition of the electromagnetic disturbance monitor was explained. The working principle of the sensor, the test methods and results of sensitivity, consistency and noise were then introduced. Combined with the installation and observation of the electromagnetic disturbance monitor at seismic stations, the observation data were finally analyzed and studied. The results show that the performance of the electromagnetic disturbance monitor is in compliance with related technical requirements. The sensitivity of the magnetic sensor is better than 50 mV/nT (0.01～10 Hz). The correlation coefficient are all greater than 0.95. The noise can reach 0.15 pT/√Hz@1 Hz in the test. Various electromagnetic disturbance events can be clearly captured in the daily observations, which verifies the feasibility of the developed electromagnetic disturbance monitor for station observation.

High-strength aluminum alloys have been widely used in aviation， aerospace and other industries because of their high specific strength and good machining property. Corrosion is an important factor affecting the safety and stability of high-strength aluminum alloys in service. Based on the preparation process of high-strength aluminum alloys， this paper focuses on the effect of structural evolution caused by heat treatment on the corrosion property of high-strength aluminum alloys. The corresponding relationship between the microstructure and corrosion behavior of high-strength aluminum alloys is analyzed. Research directions for improving the corrosion property of high-strength aluminum alloys are proposed. The segregation of elements and phases in high-strength aluminum alloys can easily lead to electrochemical inhomogeneity of microstructure， causing corrosion of substrate. Therefore， based on the optimization of composition， the melt casting process， deformation process and heat treatment process of high-strength aluminum alloys should be regulated to prepare the microstructure with uniform distribution of elements and second phases， and uniform electrochemical property， which is crucial for improving the corrosion property of high-strength aluminum alloys. In addition， the corrosion sensitivity of alloys is affected by the width of the precipitate free zone and the distance and distribution of the grain boundary precipitation phases of alloy. Thoroughly studying and clarifying the effect of various structures such as precipitate free zone on the corrosion behavior of alloys is the prerequisite for the preparation of high-strength aluminum alloys with high corrosion property. To balance the mechanical property and corrosion property of high-strength aluminum alloys， heat treatment methods such as aging and thermomechanical treatment should be optimized， and new composite heat treatment methods should be developed. Meanwhile， the test methods and evaluation methods for the corrosion property of high-strength aluminum alloys are discussed. In order to more efficiently and accurately evaluate the corrosion property and service safety of high-strength aluminum alloys， further research work should be carried out in the combined use of traditional evaluation methods with modern data processing technologies such as digital twin， virtual simulation and machine learning.

Copyright of Progress in Earthquake Sciences is the property of China Earthquake Administration, Institute of Geophysics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Safety & EMC (1005-9776) is the property of China Electronics Standardization Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Fiber Inspection / Zhongguo Xian-Jian is the property of China Fiber Inspection and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Introduction] This paper explores multiple issues including the voltage application method, test voltage standard, test casing layout, and test item sequence for the handover test of the electrical primary equipment of the world's first 500 kV offshore booster station. [Method] Based on the test conditions and requirements, a comparison and analysis of the test voltage values and the insulation strength of the equipment were conducted. According to the structural characteristics of GIS and cables, the method of jointly testing GIS and cables was used to apply voltage to the cables. Considering the spatial environment and maximum insulation distance of the offshore booster station, the 500 kV GIS withstand voltage test casing was arranged outside the booster station. By comparing the test voltage values of the test items for 500 kV and 66 kV distribution equipment, the test item sequence was arranged rationally. [Result] The voltage application method for the withstand voltage test of the medium voltage winding of the main transformer, the voltage standard for the 66 kV GIS test, and the sequence of test items for cables and GIS equipment are determined. The handover tests of transformers, cables, and GIS are completed at the manufacturing base. [Conclusion] The handover test method for the electrical primary equipment of the world's first 500 kV offshore booster station can be used to simplify the test preparation work and shorten the test period. The method demonstrates certain engineering application value and can be used as references for other offshore booster station projects.

Aims To investigate an in-line Raman method capable of detecting accidental microbial contamination in pharmaceutical vessels, such as bioreactors producing monoclonal antibodies via cell culture. Methods and results The Raman method consists of a multivariate model built from Raman spectra collected in-line during reduced-scale bioreactor batches producing a monoclonal antibody, as well as a reduced-scale process with intentional spiking of representative compendial method microorganisms (n  = 4). The orthogonal partial least squares regression discriminant analysis model (OPLS-DA) area under the curve (AUC), specificity and sensitivity were 0.96, 0.99, and 0.95, respectively. Furthermore, the model successfully detected contamination in an accidentally contaminated manufacturing-scale batch. In all cases, the time to detection (TTD) for Raman was superior compared to offline, traditional microbiological culturing. Conclusions The Raman OPLS-DA method met acceptance criteria for equivalent decision making to be considered a viable alternative to the compendial method for in-process bioburden testing. The in-line method is automated, non-destructive, and provides a continuous assessment of bioburden compared to an offline compendial method, which is manual, results in loss of product, and in practice is only collected once daily and requires 3–5 days for enumeration. [ABSTRACT FROM AUTHOR]

A method and a device for testing materials for resistance to gas-abrasive wear at normal temperatures and temperatures elevated to 1000°C is developed. The test results provide a substantiated choice of surfacing materials for restoring working surfaces of parts of exhaust fans, industrial fans, top-charging gear, gas turbine units, and other equipment. The dependences of the wear of some surfacing alloys on the test temperature, gas-abrasive flow velocity, and the angle of its attack on the sample surface is determined. It is shown that under conditions of high-temperature gas-abrasive wear at small attack angles and increased speed of abrasive particles, it is advisable to use eutectic alloys with a reduced content of expensive carbide-forming elements and carbon, and at high attack angles and low-speed abrasive, heat-resistant and refractory austenitic steels. It is found that the foreign deposited C6.0Cr23Nb7Mo7W2Si2VT alloy, characterized by the highest alloying level and volume fraction of strengthening phases, has the highest resistance to gas-abrasive wear at normal temperatures among those tested. When the test temperature increases to 600°C, its wear resistance decreases by 2.5 times, yielding to the indicator of the experimental C2.8Cr14Ni6Mn6Mo3Ti2Nb2 alloy. The processes of destruction of thin surface layers of alloys are studied using the electron-ion microscopy method, which makes it possible to evaluate the influence of their structural and phase composition on the high-temperature wear mechanism. The study of the wear pattern of the C2.8Cr14Ni6Mn6Mo3Ti2Nb2 alloy showed that under the impact action of the abrasive, cracks are formed in lamellar carbides Me3C2 and Me7C3, but the high plasticity of nickel-alloyed austenite reduces the likelihood of breakdown of the resulting fragments. At the same time, small carbides (Ti,Nb,Mo)xCy and Mo2C of a compact form restrain the plastic deformation of the austenite-carbide eutectic without destruction. [ABSTRACT FROM AUTHOR]

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

In view of the fact that there is no suitable measurement method for tire driving resistance during the operation of a transporter on soil pavement, this paper proposes a simple measurement and estimation method for driving resistance on a soil runway based on the Bekker settlement model. In this paper, using the driving resistance equation based on the Bekker model, a simplified equation of driving resistance related to mass is proposed. Using the principle of kinematics, a simple test device for driving resistance was developed, and the test data of the test device were used to determine the parameters of the driving resistance estimation equation of the road surface. The driving resistance of the wheel running state was tested by the simulated aircraft load loading vehicle through the mechanical sensor, and the consistency between the theoretical value and the actual value of the driving resistance value under 8T, 10T, and 12T loads was verified. This research shows that the test method and estimation method have low cost and good accuracy and are suitable for wide promotion. The results of this paper provide a new idea and method for estimating the driving resistance of a wheel when a transporter runs on a soil road and also provide a reference for designing the length of a soil runway. [ABSTRACT FROM AUTHOR]

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

Copyright of China Fiber Inspection / Zhongguo Xian-Jian is the property of China Fiber Inspection and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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

The durability of an asphalt concrete pavement largely depends on the quality of the bitumen binder and the strength (or degree) of its interaction with the surface of aggregates (adhesion). The method is based on the finding of bitumen adhesion with a reference substrate, which is taken to be glass. The article presents the results of obtaining the adhesion to the glass surface: bitumen of different grades; bitumen modified with various additives; bitumen modified with adhesive additives and hardened by various methods. The results of comparing the adhesion of bitumen to the glass surface with the results of the Rolling Bottle Test are presented. It has been proved that, with a certain assumption, the value of adhesion to the glass surface can be taken as indicative value for the adhesion of unmodified bitumen to the surface of granite stone materials, obtained after 6 h of testing by the Rolling Bottle Test. [ABSTRACT FROM AUTHOR]

Cement-based composites', as the most widely used building material, macroscopic performance significantly influences the safety of engineering structures. Meanwhile, the macroscopic properties of cement-based composites are tightly related to their microscopic structure. The complexity of cement-based composites' microscopic structure is challenging to describe geometrically, so fractal theory is extensively applied to quantify the microscopic structure of cement-based composites. However, existing studies have not clearly defined the quantification methods for various microscopic structures in CCs, nor have they provided a comprehensive evaluation of the correlation between the fractal dimensions of different microscopic structures and macroscopic performance. So, this study categorizes the commonly used testing methods in fractal theory into three categories: particle distribution (laser granulometry, etc.), pore structure (mercury intrusion porosity, etc.), and fracture (computed tomography, etc.). It systematically establishes a detailed process for the application of testing methods, the processing of test results, model building, and fractal dimension calculation. The applicability of different fractal dimension calculation models and the range of the same fractal dimension established by different models are compared and discussed, and the advantages and disadvantages of different models are analyzed. Finally, the research delves into an in-depth analysis of the relationship between the fractal dimension of cement-based composites' microscopic structure and its macroscopic properties, such as compressive strength, corrosion resistance, impermeability, and high-temperature resistance. The principle that affects the positive and negative correlation between fractal dimension and macroscopic performance is discussed and revealed in this study. The comprehensive review in this paper provides scholars with methods and models for quantitative research on the microscopic structural parameters of cement-based composites and offers a pathway for the non-destructive assessment of the macroscopic performance of cement-based composites. [ABSTRACT FROM AUTHOR]

The objective of the study was to create a reliable method that could be used to evaluate the particle size distribution of samples and pre-mixes in real-world situations, particularly those consisting of typical formulation blends. The goal was to use this method to assess the uniformity of the samples and ensure that they met the required quality standards. The researchers aimed to create a method that could be easily incorporated into the manufacturing process, providing a practical and efficient solution. This study demonstrates the use of ImageJ software to analyze the particle size distribution (PSD) of powders. The technique produces qualitative data from microscopy images and quantitative data from analysis of parameters including average diameter, D10, D50, D90, and standard deviation. The method was tested with various treatments, showing differentiating outcomes in all cases. The alternate technique provides a rapid and cost-effective method for PSD analysis, surpassing the limitations of sieve analysis. Extensive testing of the method, using a variety of sample types, including typical formulation blends, was performed. The results suggest that the method can effectively assess the morphology of changing materials during batch manufacturing and characterize uniformity in blends. The methodology has the capability to identify attributes related to PSD that are typically required to be monitored during manufacturing. The technique allows for accurate and reliable quantification of the attributes through image capture technology. The technique has future potential and has important implications for material science, powder rheology, pharmaceutical formulation development, and continual process monitoring. A Novel Image Processing Technique for Weighted Particle Size Distribution Assessment [ABSTRACT FROM AUTHOR]

Artificial turf provides a consistent and durable surface; however, it has historically been associated with a high skin injury risk, or a 'friction burn', when a player falls or slides. Second-generation surfaces feature a short carpet pile, whilst third generation (3G) carpet piles are longer, enabling the integration of a performance infill. 3G surfaces provide sufficient energy absorption characteristics to be approved as Rugby Turf; however, such pitches can still cause skin injuries, despite being assessed using a friction-based test. Reducing skin injury risk motivates this study to develop a more sensitive testing methodology. A new test apparatus and impactor are proposed, achieving kinematics representative of an elite male rugby tackle. A commercially available skin simulant is employed to ensure the collection of repeatable and valid data. Photography and thresholding were used to assess surface abrasion and material transfer, whilst a thermal camera captured surface temperature change. Accelerometers quantified the surface resistance during the impact and sliding phases. These metrics were compiled into the Maxwell Tribo Index (MTI), providing a single measure of skin injury risk. The results demonstrated good repeatability and validity when four teams tested four different 3G surfaces. These results compared favourably to an expert panel's ranked order. [ABSTRACT FROM AUTHOR]

Purpose – Explore the development trend of chemically-improved soil in railway engineering. Design/methodology/approach – In this paper, the technical standards home and abroad were analyzed. Laboratory test, field test and monitoring were carried out. Findings – The performance design system of the chemically-improved soil should be established. Originality/value – On the basis of the performance design, the test methods and standards for various properties of chemically-improved soil should be established to evaluate the improvement effect and control the engineering quality.

Introduction. Freezing strength is a strength characteristic of frozen soils that describes their mechanical interaction with underground structures of buildings and structures. This characteristic is used in determining the bearing capacity of piles located in the zone of permafrost, and in assessing the pull-out effect of the tangential forces of frost heaving of seasonally frozen soils. The strength of freezing is determined by laboratory experiments, through the implementation of a shift of frozen soil relative to the material being tested. There are several different methods for determining the freezing strength, but all of them have some disadvantages: some are cumbersome and difficult to carry out; in others it is impossible to simulate all types of soil freezing conditions.Materials and methods. To study the freezing strength of glass-reinforced plastic with a frozen soil specimen, the Department of Geotechnics of SPbGASU proposed a new method for determining the freezing strength of soil and underground structures, which makes it possible to reduce the labour intensity of testing, minimize the additional impact on the tested soils during their preparation, and also take into account the peculiarities of soil freezing around the foundation. However, like any new method, it has a number of uncertainties. In the framework of this study, the optimal parameters of the method were experimentally established: the ratio of the diameter of the form to its height, the design of the support, as well as the method of insulation during freezing.Results. The shape of the tested specimen has a significant influence on the final value of the freezing strength, the construction of the support and the method of insulation of the specimens influence the obtained result during the test. The best solutions are: the use of a ring-shaped support that prevents mould movement and does not prevent ground movement, and the use of insulation by immersing the specimens in the insulation rather than wrapping them in it.Conclusions. A complete method for determining the frost strength bond of soil with underground structure material is presented, the reliability of the results obtained is superior to that of the data obtained by the GOST method, as shown by the lower value of the coefficient of variation within the results of the control sample of specimens.

This study investigated the shoulder force and recoil displacement of machine guns and analyzed the influence of mounting and ground conditions. Distributed thin-film sensors were used to simultaneously measure the surface pressure at the shoulder area of the gun butt and the recoil displacement of the firearms. High-speed photography was used for the measurements. The shoulder force curve and the recoil displacement curve of the machine gun under different boundary conditions were obtained. The characteristics of the shoulder force and recoil displacement were analyzed by considering the "sliding" effect of recoil. Then, the influences of mounting and ground conditions were compared. An equivalent model for establishing the relationship between the shoulder force and the recoil displacement was constructed. The obtained results were compared with the experimental data. The experimental results indicate that the proposed method can simultaneously measure the shoulder force and recoil displacement. The shoulder force and recoil displacement are greater in the bipod condition than in the tripod condition; they are also greater in the cemented floor condition than in the sandbag-on-the-floor condition. The calculation results of the shoulder force–recoil displacement equivalent model agree well with the experimental results. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Brake fluids offer large temperature ranges of incompressible fluidity for dynamic braking performance. Modern brake fluids combine increased boiling points in “dry” (new fluid) and “wet” (used fluid after few years in vehicle) conditions with reduced cold viscosity to achieve minimized vapor lock risks with more dynamic pressure build up performances. How - ever, reduced lubrication performance risks have been observed within the development of first modern brake fluids. Since sealing rings in braking systems are “lubricated” by brake fluid and form tribo-systems, lubrication performance of the brake fluid is essential in vehicle application and is currently integrated into brake fluid standardization. Automated driving and increasing noise requests due to electrification will further increase tribological requests for the pressure medium. In order to avoid future wear and noise problems, it is essential to develop and validate appropriate test methods to assess and prescribe lubrication performance of brake fluids. Within the project TriNoWe – funded by the Federal Ministry for Economic Affairs and Energy (BMWi) – the impact parameters, stress conditions and their dependencies based on a deep tribo-system analysis were identified to develop appropriate test methods. A valid noise lab test method – provoking the product behavior in a lab test – was developed as DIN 51834-5 and was already introduced as pass/fail into international brake fluid standards. For wear, an appropriate test method based on identical test specimen and comparable tribometer use (but with incline setting, high temperature and longer load run time with load increasing starts and stops) – applicable after performed noise test – was developed as DIN 51834-6. It is in release phase by finished round robin tests to be also introduced into brake fluid standardization soon. [ABSTRACT FROM AUTHOR]