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The frictional behavior of a Mo alloy‐coated piston ring sliding against cast iron cylinder bore was recorded as a function of temperature using a reciprocating tribotester and a fully formulated synthetic engine oil, with and without a friction modifier. It was observed that, as temperature increased in a stepwise mode, friction coefficients in the presence of MoDTC exhibited two local minimal values. Only one minimal friction coefficient value at 340–355 °C (μ = 0.065) was observed in the absence of MoDTC. Chemical characterization of worn tracks of the cylinder bore using reflected FTIR spectroscopy, Raman spectroscopy and ESCA, indicated that both the base stock and the tribological additives, ZDTP and MoDTC, experienced tribochemical reactions yielding MoO₃, MoS₂ and carbonaceous species as temperature ramped up stepwise. MoO₃ and MoS₂ reaction film formation are partially responsible for the local minimal friction coefficient found at the lower temperature and the ratio of the ordered carbon species accounts partially for the other local minimal friction coefficient found at the higher temperature.

Improved fuel economy, lower emission and longer durability are the major developing trends of engine oils. Aims to describe further research on the friction coefficient of engine oils.

The lubricating durability D was defined based on definition of three characteristic points P_d, P_S, P_i and three key time lengths T_d, T_s, T_i. Two kinds of engine oils, respectively, belonging to GF‐2 and GF‐3 categories, were selected as samples to compare their lubricating durability.

Test results indicate the GF‐3 oil has much better lubricating durability than GF‐2 oil. With investigation of the topography and chemical composition changes of wear tracks along with the tribotests' time extending, the meanings of three characteristic points were discussed. Analysis indicates much better tribofilm, formed by the synergistic effect of Ca‐containing detergent with MoDTC/ZDTP in GF‐3 oil, is the major factor resulting in GF‐3 oil's longer lubricating durability.

Provides further research on lubricating durability, which is important for engine oil change and maintenance, as well as decreased cost and pollution to the environment, and improved energy conservation.

This paper aims to address the gaps in current research by exploring how blockchain technology influences corporate green innovation.

This study investigates the potential of blockchain technology to stimulate the green innovation of companies using the difference-in-difference model with a panel data set of 1,803 Chinese listed companies from 2012 to 2019.

The application of blockchain significantly increases the number of green invention patents obtained by companies but has no significant impact on green utility model patents, that is, blockchain applications improve the quality rather than the quantity of green innovation. The role of blockchain in promoting green innovation is particularly pronounced in state-owned enterprises, non-heavily polluting industries and older companies. The use of blockchain technology helps reduce sales costs and boosts research and development investments, thereby encouraging green innovation. Additionally, a company’s internal control quality plays a moderating effect.

Firstly, previous research on blockchain has primarily centered on its relationship with supply chain management. This article empirically tests the impact of blockchain applications on the green innovation of companies using the DID method. Secondly, current studies mainly explore the influencing factors on green invention patents. This article examines the impact of blockchain applications on both green invention patents and green utility model patents and identifies distinct influencing effects. Finally, this article introduces the internal control mechanism of enterprises into the DID model and explores the potential impact of the quality of internal control on the relationship between blockchain and green innovation.

This paper aims to propose a two-stage vibration isolation system for large airborne equipment to isolate aircraft vibration load.

First, the vibration isolation law of the discrete model of large airborne equipment under different damping ratios, stiffness ratios and mass ratios is analyzed, which guides the establishment of a three-dimensional solid model of large airborne equipment. Subsequently, the vibration isolation transfer efficiency is analyzed based on the three-dimensional model of the airborne equipment, and the angular and linear vibration responses of the two-stage vibration isolation system under different frequencies are studied.

Finally, studies have shown that the steady-state angular vibration at the non-resonant frequency changes little. In contrast, the maximum angular vibration at the resonance peak reaches 0.0033 rad, at least 20 times the response at the non-resonant frequency. The linear vibration at the resonant frequency is at least 2.14 times the response at the non-resonant frequency. Obviously, the amplification factor of linear vibration is less than that of angular vibration, and angular vibration has the most significant effect on the internal vibration of airborne equipment.

The two-stage vibration isolation equipment designed in this paper has a positive guiding significance for the vibration isolation design of large airborne equipment.

Improvement and optimization design of a two-stage vibration isolation system proposed in this paper are conducted to ensure the device of electronic work effective.

The proposed two-stage vibration isolation system of airborne equipment is optimized and parameterized based on multi-objective genetic algorithm.

The results show that compared with initial two-stage vibration isolation system, the angular vibration of the two-stage vibration isolation system becomes 3.55 × 10^-4 rad, which decreases by 89%. The linear isolation effect is improved by at least 67.7%.

The optimized two-stage vibration isolation system effectively improves the vibration reduction effect, the resonance peak is obviously improved and the reliability of the mounting bracket and the shock absorber is highly improved, which provides an analysis method for two-stage airborne equipment isolation design under complex dynamic environment.

Tribological research is complex and multidisciplinary, with many parameters to consider. As traditional experimentation is time-consuming and expensive due to the complexity of tribological systems, researchers tend to use quantitative and qualitative analysis to monitor critical parameters and material characterization to explain observed dependencies. In this regard, numerical modeling and simulation offers a cost-effective alternative to physical experimentation but must be validated with limited testing. This paper aims to highlight advances in numerical modeling as they relate to the field of tribology.

This study performed an in-depth literature review for the field of modeling and simulation as it relates to tribology. The authors initially looked at the application of foundational studies (e.g. Stribeck) to understand the gaps in the current knowledge set. The authors then evaluated a number of modern developments related to contact mechanics, surface roughness, tribofilm formation and fluid-film layers. In particular, it looked at key fields driving tribology models including nanoparticle research and prosthetics. The study then sought out to understand the future trends in this research field.

The field of tribology, numerical modeling has shown to be a powerful tool, which is both time- and cost-effective when compared to standard bench testing. The characterization of tribological systems of interest fundamentally stems from the lubrication regimes designated in the Stribeck curve. The prediction of tribofilm formation, film thickness variation, fluid properties, asperity contact and surface deformation as well as the continuously changing interactions between such parameters is an essential challenge for proper modeling.

This paper highlights the major numerical modeling achievements in various disciplines and discusses their efficacy, assumptions and limitations in tribology research.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2023-0076/

This study aims to determine the nexus between agricultural production and agricultural loans for the period Q1 2003–Q4 2018 in Turkey.

The authors employ the time-series analyses within the scope of the study. Firstly, they run the Engle–Granger two-step cointegration test and the Toda–Yamamoto causality analysis. They also use the dynamic ordinary least squares (DOLS) model estimator and estimate the vector autoregression model for predicting the dynamic structure of time series.

The results of time series analyses reveal that the variables are cointegrated and there are causal relationships between agricultural loans and agricultural production. Also, the variance decomposition findings indicate that the effect of agricultural loans provided by development-investment banks and participation banks on agricultural production has increased over the years, and the deposit banks have a high impact on agricultural production. The results of the DOLS model indicate that agricultural loans have a positive effect on agricultural production.

This research is one of the few studies that comprehensively determines the direction of nexus between agricultural production and agricultural loans in Turkey economy. This is the first contribution of the study in the literature. Another contribution of this study is to investigate the nexus between agricultural production and agricultural loans for banking sector groups. Unlike other studies in the literature, this study calculates the variance decomposition by going beyond unit root and cointegration tests. Thus, this study has deep findings.

The purpose of this paper is to focus on investigating labour productivity in the agricultural sector of Sub-Sahara Africa (SSA) countries between the periods of 2010 and 2017.

The study adopted descriptive design. The sample size for this research includes 43 SSA nations. Measuring SSA nation’s agricultural productivity in this study was based on input and output factors relating to the labour resource utilisation between the periods of 2010 and 2017. Data envelopment analysis (DEA) and panel regression analysis were carried out to examine labour productivity within the set periods.

The findings from the study suggest that labour productivity in the agricultural sector of SSA countries can be improved from its presently low state of productivity. The statistical analysis showed that between the periods of 2010 and 2013, only about 34.9 per cent of countries in the region were technically efficient in the utilisation of labour resources for productive use. More disturbing was that, from 2014 to 2017, labour productivity drooped to 11.6 per cent. Meanwhile, employment of labour in the agricultural sector revealed as low as 1.58 percentage to crop production index in the region. Notably, there is the potential of labour employment to derive as high as 80 per cent yield to the gross domestic product of economies in the SSA region.

Considering the strategic role of labour to the agricultural sector of SSA countries, there must be a stakeholders approach to stimulating the interest of the populace of these countries and getting them actively involved in the agricultural sector. This imply that government, investors, support agencies from developed economies and populace of the SSA nations must support the drive towards agricultural productivity of the SSA nations.

This study established a research agenda that involved a paradigm shift from the more rampant literature on foreign investments, agricultural research, rural livelihood and well-being, among others to focusing on issues that pertain to labour productivity for sustainable agricultural yields in SSA countries. Also, the methodology adopted in the study, such as application of DEA and regression analysis to panel data, shows a departure from single units of analysis adopted by existing studies.