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Article
Publication date: 15 November 2018

Huawei Zeng, Qiao Jie, Zeng Xin, Xu Dayong, Xiong Minghua, Li Feng, Sun Jianfan, Jiang Xuan and Dai Chuanyun

Monascus pigment was widely applied in food processing industry as functional additive, so more attention was paid to the fermentation optimization of pigment production…

352

Abstract

Purpose

Monascus pigment was widely applied in food processing industry as functional additive, so more attention was paid to the fermentation optimization of pigment production. Therefore, this paper aims to evaluate the best possible fermentative conditions for maximum production of biopigment using submerged fermentation (SFM) and solid state fermentation (SSF) by Monascus purpureus HBSD 08.

Design/methodology/approach

The biopigment was produced by using an SMF and an SSF with optimized substrate to achieve higher yield. The antioxidant activity was evaluated by DPPH radical scavenging ability, superoxide anion radical scavenging ability and hydroxyl radical scavenging ability. The pigment composition was analyzed by thin layer chromatography.

Findings

Maximum Monascus pigment production (79.6 U/ml and 1,102 U/g) were obtained under an SFM and an SFF. The antioxidant activity of the pigment in an SFM was significantly higher than that in an SFM. The composition of pigment was not different in an SFM and an SFF.

Originality/value

The study developed new conditions, and Monascus strain was a candidate for producing pigment in an SFM and an SFF. To the authors’ best knowledge, this is a first attempt toward comparative evaluation on antioxidant capacity and composition between pigment in an SSF and an SFM. This result will serve for Monascus pigment production.

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Article
Publication date: 2 December 2024

Minghua Pang, Zhenjiang Li, Yikun Hu, Zichen Gan, Lijie Ma and QigaoFeng Feng

This study aims to improve the lubrication performance of molybdenum disulfide powders at textured surface of cemented carbide materials, a squeeze motion of vibration assistance…

50

Abstract

Purpose

This study aims to improve the lubrication performance of molybdenum disulfide powders at textured surface of cemented carbide materials, a squeeze motion of vibration assistance method was introduced and investigated.

Design/methodology/approach

Surface texture was fabricated on YT15 cemented carbide samples using a laser marking machine. After that, a tribological experiment was carried out on a self-built friction testing machine under different amplitude and frequency of squeeze motion conditions. Moreover, a simulation model was also established to verify the principle of squeeze motion on the lubrication performance improving of MoS2 particles at textured interfaces.

Findings

Analysis results indicated that surface texture on test sample can increase the storage ability of solid lubrication particles, and the lubrication film at the contact interface is more easily formed due to the reciprocating action. Squeeze motion can improve the storage ability of it due to an intermittent contact, which provides an opportunity for MoS2 particles infiltration, and then a more uniform distribution and load-bearing properties of force chain are also established and formed simultaneously. Thus, a better tribological performance at the contact interface is obtained.

Originality/value

The main contribution of this work is to provide a reference for the molybdenum disulfide powder lubrication with textured surface of cemented carbide materials.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2024-0166/

Details

Industrial Lubrication and Tribology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 March 2021

Jie Lin and Minghua Wei

With the rapid development and stable operated application of lithium-ion batteries used in uninterruptible power supply (UPS), the prediction of remaining useful life (RUL) for…

565

Abstract

Purpose

With the rapid development and stable operated application of lithium-ion batteries used in uninterruptible power supply (UPS), the prediction of remaining useful life (RUL) for lithium-ion battery played an important role. More and more researchers paid more attentions on the reliability and safety for lithium-ion batteries based on prediction of RUL. The purpose of this paper is to predict the life of lithium-ion battery based on auto regression and particle filter method.

Design/methodology/approach

In this paper, a simple and effective RUL prediction method based on the combination method of auto-regression (AR) time-series model and particle filter (PF) was proposed for lithium-ion battery. The proposed method deformed the double-exponential empirical degradation model and reduced the number of parameters for such model to improve the efficiency of training. By using the PF algorithm to track the process of lithium-ion battery capacity decline and modified observations of the state space equations, the proposed PF + AR model fully considered the declined process of batteries to meet more accurate prediction of RUL.

Findings

Experiments on CALCE dataset have fully compared the conventional PF algorithm and the AR + PF algorithm both on original exponential empirical degradation model and the deformed double-exponential one. Experimental results have shown that the proposed PF + AR method improved the prediction accuracy, decreases the error rate and reduces the uncertainty ranges of RUL, which was more suitable for the deformed double-exponential empirical degradation model.

Originality/value

In the running of UPS device based on lithium-ion battery, the proposed AR + PF combination algorithm will quickly, accurately and robustly predict the RUL of lithium-ion batteries, which had a strong application value in the stable operation of laboratory and other application scenarios.

Details

International Journal of Intelligent Computing and Cybernetics, vol. 14 no. 2
Type: Research Article
ISSN: 1756-378X

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Article
Publication date: 23 December 2024

Minghua Ye, Kang Chen, Tongjiang Wang and Junsheng Zhu

Crop price insurance can reduce losses from price volatility for crop producers, but pricing is one paramount important issue. The objective of this research is to provide a…

15

Abstract

Purpose

Crop price insurance can reduce losses from price volatility for crop producers, but pricing is one paramount important issue. The objective of this research is to provide a tentative method for pricing of crop price insurance with data from the futures market.

Design/methodology/approach

With weekly settlement price of January corn futures from the second week of January 2009 to the fourth week of April 2020 in China, we assume that corn futures price follows fractional Brownian motion, and apply an improved Black model.

Findings

Our results reveal that the proposed model can be used to yield a fair premium and crop price insurance with varying insured prices and gradient coverage ratios can be used to meet the divergent needs of farmers at an affordable cost for price risk management purposes.

Research limitations/implications

Results can be fine-tuned by extending research to crops such as wheat and rice, and by modeling price volatility with data from options market.

Originality/value

This study offers one plausible way to rate crop price insurance using data from the futures market, and thus adds to this thread of literature by incorporating fractional Brownian motion into an improved Black model.

Details

Journal of Agribusiness in Developing and Emerging Economies, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2044-0839

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Article
Publication date: 29 April 2022

Shuaijie Zhai, Qiaogao Feng, Hui Yang, Lijie Ma and Minghua Pang

The purpose of this paper is to study a new liquid-phase assisted texture treatment method to improve the tribological properties of 304 stainless steel.

132

Abstract

Purpose

The purpose of this paper is to study a new liquid-phase assisted texture treatment method to improve the tribological properties of 304 stainless steel.

Design/methodology/approach

Three groups of textured type (KY, KJ and YJ) were prepared on 304 stainless steel surface using laser circular and cross scanning method in air and liquid assisted condition. The surface morphology and element content of test samples were measured with scanning electron microscope, energy spectrum. Then, the tribological test was carried out using MWF-500 reciprocating friction and wear testing machine under dry and oil lubrication condition.

Findings

The experimental results showed that the textured surface of laser processing in air was obviously blackened, and the oxygen content was increased from 16.9% to 24%. These cases did not occur on liquid-assisted laser textured surface, which induced a better wettability and surface texture processing quality. For friction test, the friction coefficient of cross-scanning textured surface prepared in assisted liquid (YJ) was the smallest. It is reduced by 55% in oil lubrication case compared to the original surface (YS). The cross-scanning textured surface prepared in air (KJ) was a little worse in friction coefficient and a little better in wear quantity than the cross-scanning textured surface prepared in assisted liquid (YJ). It is indicated that the laser processing surface with assisted liquid has obvious advantages in surface texture quality and interfacial tribological property. The main reason is that the assisted liquid plays a role in cooling and protecting action of the machined surface. The bubbles, generated at the solid–liquid interface because of the laser heat effect, scatter the laser beam and carry out the processed melt meanwhile. The lubricating medium is easier to penetrate and store in the contact interfaces because of the higher surface textured performance and wettability.

Originality/value

The main contribution of this work is in providing a new surface texture processing method that has a better surface micropits quality and interfacial tribology regulation ability.

Details

Industrial Lubrication and Tribology, vol. 74 no. 6
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 10 August 2018

Minghua Pang, Xiaojun Liu and Kun Liu

This study aims to clarify the influence mechanism of surface texture (arrays of circular/square and concave/convex) on the frictional properties of WC-TiC/Co cemented carbide…

174

Abstract

Purpose

This study aims to clarify the influence mechanism of surface texture (arrays of circular/square and concave/convex) on the frictional properties of WC-TiC/Co cemented carbide under a water-miscible cutting fluid (JAEGER SW-105, 5 per cent) environment.

Design/methodology/approach

Four types of textured cemented carbide surfaces (arrays of circular/square and concave/convex that have different textured densities and sizes) were fabricated using laser surface technology. Pin-on-disc tests between an AISI 304 stainless steel ball and WC-TiC/Co cemented carbide samples were carried out for a variety of normal loads (1, 3 and 5 N) under a water-miscible cutting fluid environment. The effects of textured type, density and size on the friction coefficient were obtained.

Findings

Compared to a smooth surface, some textured samples successfully resulted in a reduced friction coefficient. The friction coefficient of textured WC-TiC/Co cemented carbide samples depended greatly on the textured type, density and size. Given the increase in textured density (ranging from 10 to 30 per cent), the friction coefficient of the test samples first decreased and then increased for all normal loads (1, 3 and 5 N), and the minimum friction coefficient was obtained at the textured density of 20 per cent. The concave textured surface showed obvious advantages in friction coefficient reduction regardless of textured density, size and normal load compared with the convex textured surface. Finally, the correlation between textured diameter/length and Hertzian contact width was studied for various normal loads and texture sizes. A 2.6 ratio of textured diameter/length to Hertzian contact width is recommended under for lubricated sliding contact with the water-miscible cutting fluid.

Originality/value

The main contribution of this work is in providing a design reference and obtaining an essential understanding on the effect of surface texture (arrays of circular/square and concave/convex) on the friction of WC-TiC/Co cemented carbide under a water-miscible cutting fluid environment.

Details

Industrial Lubrication and Tribology, vol. 70 no. 7
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 24 August 2022

Yanfu Wang, Xin Wang and Lifei Liu

Lapping is a vital flattening process to improve the quality of processed semiconductor wafers such as single-crystal sapphire wafers. This study aims to optimise the lapping…

114

Abstract

Purpose

Lapping is a vital flattening process to improve the quality of processed semiconductor wafers such as single-crystal sapphire wafers. This study aims to optimise the lapping process of the fixed-abrasive lapping plate of sapphire wafers with good overall performance [i.e. high material removal rate (MRR), small surface roughness (Ra) of the wafers after lapping and small lapping plate wear ratio (η)].

Design/methodology/approach

The influence of process parameters such as lapping time, abrasive size, abrasive concentration, lapping pressure and lapping speed on MRR, Ra and η of lapping-processed sapphire wafers was studied, and the results were combined with experimental data to establish a regression model. The multi-evaluation index optimisation problem was transformed into a single-index optimisation problem via an entropy method and the grey relational analysis (GRA) to comprehensively evaluate the performance of each parameter.

Findings

The results revealed that lapping time, abrasive size, abrasive concentration, lapping pressure and lapping speed had different influence degrees on MRR, Ra and η. Among these parameters, lapping time, lapping speed and abrasive size had the most significant effects on MRR, Ra and η, and the established regression equations predicted the response values of MRR, Ra and η to be 99.56%, 99.51% and 93.88% and the relative errors between the predicted and actual measured values were <12%, respectively. With increased lapping time, MRR, Ra and η gradually decreased. With increased abrasive size, MRR increased nearly linearly, whereas Ra and η initially decreased but subsequently increased. With an increase in abrasive concentration, MRR, Ra and η initially increased but subsequently decreased. With increased lapping pressure, MRR and η increased nearly linearly and continuously, whereas Ra decreased nearly linearly and continuously. With increased lapping speed, Ra initially decreased sharply but subsequently increased gradually, whereas η initially increased sharply but subsequently decreased gradually; however, the change in MRR was not significant. Comparing the optimised results obtained via the analysis of influence law, the parameters optimised via the entropy method and GRA were used to obtain sapphire wafers lapping with an MRR of 4.26 µm/min, Ra of 0.141 µm and η of 25.08, and the lapping effect was significantly improved.

Originality/value

Therefore, GRA can provide new ideas for ultra-precision processing and process optimisation of semiconductor materials such as sapphire wafers.

Details

Microelectronics International, vol. 39 no. 4
Type: Research Article
ISSN: 1356-5362

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