Search results

The purpose of this paper is to initiate investigations to develop near infrared (NIR) spectroscopy coupled with spectral dimensionality reduction and multivariate calibration methods to rapidly measure cotton content in blend fabrics.

In total, 124 and 41 samples were used to calibrate models and assess the performance of the models, respectively. The raw spectra are transformed into wavelet coefficients. Multivariate calibration methods of partial least square (PLS), extreme learning machine (ELM) and least square support vector machine (LS-SVM) were employed to develop the models using 100 wavelet coefficients. Through comparing the performance of PLS, ELM and LS-SVM models with new samples, the optimal model of cotton content was obtained with the LS-SVM model.

The correlation coefficient of prediction (r_p) and root mean square errors of prediction were 0.99 and 4.37 percent, respectively. The results suggest that NIR spectroscopy, combining with the LS-SVM method, has significant potential to quantitatively analyze cotton content in blend fabrics.

It may have commercial and regulatory potential to avoid time-consuming work, costly and laborious chemical analysis for cotton content in blend fabrics.

The purpose of this paper is to develop near infrared (NIR) techniques coupled with multivariate calibration methods to rapid measure cotton content in blend fabrics.

In total, 124 and 41 samples were used to calibrate models and assess the performance of the models, respectively. Multivariate calibration methods of partial least square (PLS), extreme learning machine (ELM) and least square support vector machine (LS-SVM) were employed to develop the models. Through comparing the performance of PLS, ELM and LS-SVM models with new samples, the optimal model of cotton content was obtained with LS-SVM model. The correlation coefficient of prediction (r _p ) and root mean square errors of prediction were 0.98 and 4.50 percent, respectively.

The results suggest that NIR technique combining with LS-SVM method has significant potential to quantitatively analyze cotton content in blend fabrics.

It may have commercial and regulatory potential to avoid time consuming work, costly and laborious chemical analysis for cotton content in blend fabrics.

The purpose of this paper is to study the temperature characteristics of hydro-viscous clutch with different structure of friction disks and obtain the distribution of film temperature.

The mathematical model of oil film between friction disks with radial grooves is established. Based on the flow rate equation, the temperature rise equation of oil film is deduced. Considering two-phase flow, the temperature distribution in the oil shear stage and the effects of the ratio of inner radius to outer radius on film temperature rise is studied by using computational fluid dynamics (CFD) technology.

The results show that when input speed is constant, the increase in the ratio of inner to outer radius leads to an increase in the peak temperature and the decrease in the ratio results in a larger increasing rate of temperature.

These results are of interest for the study of hydro-viscous drive and its applications. This study can also provide a theoretical basis for the mechanism of temperature rise by considering the effect of two-phase flow.

The leakage problem caused by machining error, assembly error, wearing and thermal deformation has been the main factor hindering the development of scroll compressor. This paper aims to investigate the lubrication characteristics of radial clearance and further optimize the radial clearance, which can reduce the leakage in the tangential direction of the working chamber.

This paper establishes a model of radial clearance oil film lubrication in scroll compressor. And, the method to solve the Reynolds and energy equations is presented, as well as the dimensionless and discretization by finite element difference method. To verify the established model, performance experiment of scroll compressor for electric vehicle air conditioning system is also carried out.

Based on the presented model, the temperature field and distribution of the oil film in the radial clearance are analyzed. And the influence of the structural parameter on the radial clearance is further discussed. The optimum radial clearance could be achieved at β = 40°–42°, where the orbiting scroll is in the state of rotary balance. And, the simulation results coincide well with the experimental results.

This work provides an effective model to evaluate the lubrication characteristics of radial clearance in scroll compressor, which can provide guidance for the design of scroll compressor.

The behavioral decision-making of digital-self is one of the important research contents of the network of crowd intelligence. The factors and mechanisms that affect decision-making have attracted the attention of many researchers. Among the factors that influence decision-making, the mind of digital-self plays an important role. Exploring the influence mechanism of digital-selfs’ mind on decision-making is helpful to understand the behaviors of the crowd intelligence network and improve the transaction efficiency in the network of CrowdIntell.

In this paper, the authors use behavioral pattern perception layer, multi-aspect perception layer and memory network enhancement layer to adaptively explore the mind of a digital-self and generate the mental representation of a digital-self from three aspects including external behavior, multi-aspect factors of the mind and memory units. The authors use the mental representations to assist behavioral decision-making.

The evaluation in real-world open data sets shows that the proposed method can model the mind and verify the influence of the mind on the behavioral decisions, and its performance is better than the universal baseline methods for modeling user interest.

In general, the authors use the behaviors of the digital-self to mine and explore its mind, which is used to assist the digital-self to make decisions and promote the transaction in the network of CrowdIntell. This work is one of the early attempts, which uses neural networks to model the mental representation of digital-self.

The main purpose of this paper is to investigate the vibration isolation performance of a quasi-zero stiffness (QZS) metastructure by employing the band gap (BG) mechanism.

The metastructure QZS characteristic was investigated through static analysis by numerical simulation. Based on that, the BG mechanism is primarily used in this article to investigate the wave propagation characteristics of this structure. The model's dispersion relation is then examined using theoretical (perturbation method) and finite element techniques. The dynamic response of the finite-size systems and experimental analysis is used to confirm the vibration mitigation property under investigation. Finally, the model's ability to absorb energy was examined and contrasted with a traditional model.

The analytical analysis reveals the dispersion curve and the effect of the nonlinear parameter on the curve shifting. The dispersion curve in the finite element method (FEM) result depicts five complete BGs within the range of 0–1,000 Hz, and the BG width accounted for 67.4% of the frequency concerned (0–1,000 Hz). Eigenmodes of the dispersion curves were analyzed to investigate the BG formation mechanisms. The dependence of BG opening and closure on structure parameters was also studied. Finally, the energy absorption property of the QZS metastructure was evaluated by comparing it with a classical model. The QZS structure absorbs 4.08 J/Kg compared to the 3.69 J/Kg absorbed by the classical model, which reveals that the QZS demonstrates better energy absorption performance. Based on the BG mechanism, it is clear that this model is an excellent vibration isolator, and the study reveals the frequencies at which complete vibration mitigation is achieved. As a result, this model could be a promising candidate for vibration mitigation engineering structures and energy absorption.

The tough vibration issue, which is primarily experienced in mechanical equipment, will be resolved in this study. This study provides a precise understanding of the QZS metastructure's isolation of vibration, including the frequencies at which this isolation occurs.

The purpose of this paper is to enhance sealing and rotordynamic performance of hole-pattern damping seal (HPDS) and labyrinth seal (LS) by structural innovation and geometrical optimization of special-shaped hole or annular-groove cavity.

The unsteady flow was transformed into steady one using moving reference frame method. The full period numerical models of LS and HPDS were established. The influence of special-shaped hole or annular-groove cavity at axial inclined angle on leakage rate and rotordynamic coefficient of these two seals at different whirl angular speed were investigated.

The results show that dynamic characteristics of straight-tooth LS are better than that of slanted-tooth LS. Compared to typical straight-hole damping seal, HPDS with windward oblique-hole when axial inclined angle ranges from 50 to 60° has superiority in both leakage and rotordynamic characteristics by considering smaller cross-coupled stiffness coefficient and whirl frequency ratio, larger direct damping coefficient and effective damping coefficient.

A novel HPDS with special-shaped three-dimensional hole cavity was proposed to enhance leakage and rotordynamic performance. The optimized geometrical structures of HPDS for excellent sealing and rotordynamic characteristics were obtained.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2020-0262/

The purpose of this study is to investigate the impact of internal control weaknesses on accounting conservatism in Chinese listed firms. It also investigates the relationship between the demand for external audit and accounting conservatism, and whether additional assurance of internal control reports (ICRs) can mitigate the negative impact of ICWs on accounting conservatism.

An empirical research approach is taken through the use of ordinary least squares (OLS) models and hand-collected internal control weakness data from ICRs released by Chinese listed firms.

The results of this paper show that the existence of ICWs has a negative effect on accounting conservatism in China. Further, the results demonstrate that both accounting-related and non-accounting-related ICWs affect accounting conservatism. The authors also find that there is a complementary relationship between accounting conservatism and the demand for additional assurance of ICRs, and additional assurance of ICRs can mitigate the negative impact of ICWs on accounting conservatism.

This study provides timely evidence to Chinese regulators of the possible economic consequences of the official implementation of internal control standard in China from 2012. The findings of this paper can also benefit regulators around the world and, in particular, the regulators in emerging markets that are considering implement regulations similar to the US SOX.

The paper demonstrates that a wider scope of ICWs, including non-accounting-related ICWs, also has a significant impact on accounting conservatism. Therefore, this research provides a more general evidence on the relationship between internal control quality and accounting conservatism.

The purpose of this study is to investigate the effects of nanoadditive lubricants on the vibration and noise characteristics of helical gears compared with conventional lubricants. The experiment aims to analyze whether nanoadditive lubricants can effectively reduce gear vibration and noise under different speeds and loads. It also analyzes the sensitivity of the vibration reduction to load and speed changes. In addition, it compares the axial and radial vibration reduction effects. The goal is to explore the application of nanolubricants for vibration damping and noise reduction in gear transmissions. The results provide a basis for further research on nanolubricant effects under high-speed conditions.

Helical gears of 20CrMnTi were lubricated with conventional oil and nanoadditive oils. An open helical gearbox with spray lubrication was tested under different speeds (200–500 rpm) and loads (20–100 N·m). Gear noise was measured by a sound level meter. Axial and radial vibrations were detected using an M+P VibRunner system and fast Fourier transform analysis. Vibration spectrums under conventional and nanolubrication were compared. Gear tooth surfaces were observed after testing. The experiment aimed to analyze the noise and vibration reduction effects of nanoadditive lubricants on helical gears and the sensitivity to load and speed.

The key findings are that nanoadditive lubricants significantly reduce the axial and radial vibrations of helical gears under low-speed conditions compared with conventional lubricants, with a more pronounced effect on axial vibrations. The vibration reduction is more sensitive to rotational speed than load. At the same load and speed, nanolubrication reduces noise by 2%–5% versus conventional lubrication. Nanoparticles change the friction from sliding to rolling and compensate for meshing errors, leading to smoother vibrations. The nanolubricants alter the gear tooth surfaces and optimize the microtopography. The results provide a basis for exploring nanolubricant effects under high speeds.

The originality and value of this work is the experimental analysis of the effects of nanoadditive lubricants on the vibration and noise characteristics of hard tooth surface helical gears, which has rarely been studied before. The comparative results under different speeds and loads provide new insights into the vibration damping capabilities of nanolubricants in gear transmissions. The findings reveal the higher sensitivity to rotational speed versus load and the differences in axial and radial vibration reduction. The exploration of nanolubricant effects on gear tribological performance and surface interactions provides a valuable reference for further research, especially under higher speed conditions closer to real applications.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2023-0220/

Honey peaches are rich in a variety of vitamins and are well known in China as the queen of fruit. However, as highly climacteric fruit, peach is too easy to affect its economic value. In this paper, a new passive modified atmosphere packaging system was proposed to solve the lack of water vapour removal capacity – which is still the technical bottleneck of passive modified atmosphere packaging. This paper aims to address this issue.

Under the conditions of relative humidity 85−90% and temperature 28°C−38°C, the influence of new passive modified atmosphere packaging on the shelf life and quality of 70% ripe peaches was studied in the paper. The effect of the new passive modified atmosphere packaging (PMAP) on fruit appearance, colour, taste, flavour, soluble solids, Vitamin C and titratable acid was investigated.

Regardless of whether 1-Methylcyclopropene is added or not, the research results show that the new PMAP has a significant effect on extending the shelf life and maintaining the quality of peaches. Compared with the control group, the shelf life of peaches treated with modified atmosphere packaging and 1-Methylcyclopropene was prolonged by 7 and 11 days, increasing the retailer's revenue by 44 and 75%.

A new integrated structure, which is composed of two types of films with high oxygen and high water vapour permeability was designed for the retail of peaches at room temperature. The former was mainly responsible for regulating the concentration of O₂ and CO₂, while the latter was for removing water vapour and regulating the relative humidity in PMAP.