Mechanism-based wear debris classification (WDC) is important for root cause analysis and prediction of wear related faults. Compared to manual classifications, automatic WDC is more efficient and ...often more reliable for a wide range of industrial applications. However, existing methods unavoidably encounter some difficulties when dealing with those wear particles with highly geometric similarity, especially for fatigue particles and severe sliding particles. To meet the requirement for automatic WDC, an integrated, automated method for identifying typical wear debris is proposed with a two-level classification procedure. By referring to the traditional ferrography – a widely used wear particle imaging and analysis technique, the first-level classification is performed by a general back-propagation (BP) neural network with selected particle's morphological features. By doing this, three types of wear particles including rubbing, cutting, and spherical particles can be determined. In the second-level classification, a deep learning model of a 6-layer convolution neural network (CNN) is adopted to identify fatigue particles and severe sliding particles by analyzing their very slight surface details in pixel-level. The method is tested with over 100 images of real particles generated from an extruder machine in a petrochemical plant and identified by a ferrograph specialist. A high recognition rate of over 80% is achieved for the three types including rubbing, cutting, and spherical particles with the first procedure. Further, the identification rates are 85.7% and 80% for fatigue particles and severe sliding particles, respectively, which is distinctly improved from the reported values (they are 45.5% and 36.4%, respectively) of other intelligent methods.
•Four typical groups of wear particles are characterized using numerical parameters.•A BP neural network is adopted to identify rubbing, cutting, and spherical particles.•Fatigue and serious sliding wear particles were identified by a 6-layer CNN.
Background
Lung cancer is one of the most aggressive malignancies and the efficacy of chemotherapy or concurrent chemoradiation is limited in clinical application. Curcumin has been reported to block ...cancer development by modulating multiple signaling pathways. However, whether curcumin can inhibit gemcitabine-resistant non-small cell lung cancer through regulation of lncRNA and the involved molecular mechanisms are rarely reported.
Materials and methods
MTT assay, clonogenic assay, apoptosis assay, qRT-PCR, Western blotting, immunohistochemistry, xenograft experiment were carried out in the present study.
Results
The results showed that curcumin suppressed gemcitabine-resistant non-small cell lung cancer cell proliferation and induced apoptosis. Curcumin upregulated the expression of lncRNA-MEG3 and PTEN, and MEG3 overexpression could increase the level of PTEN expression, while MEG3 knockdown decreased the level of PTEN expression in gemcitabine-resistant non-small cell lung cancer cells. Curcumin treatment failed to inhibit the proliferation and induce apoptosis in MEG3 knockdown or PTEN knockdown cells.
Conclusions
These findings show the antitumor activity of curcumin for potential clinical application in gemcitabine-resistant non-small cell lung cancer treatment.
Despite the prominence of the competitive strategy perspective, it remains unclear whether foreign firms entering China can still adopt a differentiation or low-cost position to achieve superior ...performance, given the unique market and institutional environments in China. Alternatively, should foreign firms follow conventional wisdom and actively build managerial ties with government officials and business community to enhance their performance? This study develops and tests an interactive perspective that highlights the moderating effects of managerial ties on competitive position-performance relationships. The results indicate that though both differentiation and low-cost positions foster foreign firm profitability, the benefit of a differentiation position is conditional on political and business ties in different directions: political ties impede and business ties strengthen the positive effect of a differentiation position on foreign firms' profitability. Moreover, foreign firms benefit from their use of business ties, but their profitability suffers when they rely increasingly on the heavy use of political ties.
The first standardized, global assessment of these fishes, using Red List criteria, reveals threatened species needing protection.
There is growing concern that in spite of the healthy status of ...several epipelagic (living near the surface) fish stocks (
1
), some scombrid (tunas, bonitos, mackerels, and Spanish mackerels) and billfish (swordfish and marlins) species are heavily overfished and that there is a lack of resolve to protect against overexploitation driven by high prices (
2
–
5
). Many populations are exploited by multinational fisheries whose regulation, from a political perspective, is exceedingly difficult. Thus, assessment and management is complicated and sometimes ineffective (
4
). Regional Fisheries Management Organizations (RFMOs) were created to manage and conserve scombrids and billfishes because of their transnational distributions and widespread economic importance (
6
). However, species-specific catch data for many scombrids and billfishes are not collected or are aggregated with other species. Even for the larger tunas, for which relatively rich data exist, population assessments and data are complex (
1
) and are difficult to combine across RFMOs, which prompts a need for alternative means of assessment.
This paper presents an experimental study on the influence of groove-textured surface on tribological behaviors and friction-induced vibration and noise properties. Groove-textured surfaces with ...different widths and pitches were manufactured on compacted graphite iron materials (brake disc material) by electromachining. The difference between the groove-textured and original smooth surfaces in friction and wear and vibration and noise properties was studied, by using a developed device which is able to synchronously measure and analyze the friction force, vibration acceleration and noise signals in a ball-on-flat reciprocating sliding configuration. It is shown that the squeal generated from the groove-textured surface was more influenced by the dimensional proportion of groove width to pitch, instead independently by groove width or pitch. Groove-textured surfaces with a specific dimensional proportion of groove width to pitch of 1/2, i.e., the width of groove equal to the width of ridge, showed good potential in reducing and suppressing squeal. The groove was the dominant surface component of contact surface topography affecting the generation of squeal compared to the microscopic irregularities of the worn surface. The wave-fluctuations of the friction force caused by counterface ball sliding across the grooves were found to play a crucial role in the squeal generation, which can effectively disturb the self-excited vibration of the friction system and consequently reduce the tendency to squeal.
Aims
To evaluate the effects of various epiphytic microbiota from Italian ryegrass (IR), maize (MZ) and sorghum (SG) on fermentative profile and microbial community dynamics in sterile IR.
Methods ...and Results
Using microbiota transplantation, the irradiated IR was treated with the following: (i) sterile water; (ii) epiphytic microbiota on IR (IRIR); (iii) epiphytic microbiota on MZ (IRMZ); (iv) epiphytic microbiota on SG (IRSG). After 60 days of ensiling, MZ and SG microbiota significantly (P < 0·05) decreased lactic acid (LA) and acetic acid (AA) concentrations compared to IR microbiota, while SG microbiota notably (P < 0·05) reduced the ratio of LA to AA than MZ and IR microbiota. Apparently (P < 0·01) higher amounts of Lactobacillus genus were observed in IRIR and IRMZ groups on 60 day compared to IRSG group, and the dominant Lactococcus genus on 3 day was eventually replaced by Enterobacteriaceae and Lactobacillus in IRSG group.
Conclusions
Exogenous microbiota could evidently affect the fermentative profile and microbial community dynamics of IR silage. The numbers of Enterobacteriaceae and Lactobacillus were mainly responsible for this.
Significance and Impact of the Study
Identifying the role of microbe during ensiling is of great significance to manipulate the fermentation products and improve the preservation of silage.
Aims
Cellulase‐producing Enterococcus species isolated from the rumen of Tibetan yak (Bos grunniens) were characterized, and their combined effects on the silage quality of various forages were ...studied.
Methods and Results
The two isolated strains with high cellulolytic potential were identified as Enterococcus faecalis (EF85) and E. faecium (EF83) by 16S rRNA sequencing. Both EF85 and EF83 could grow well at 15–55°C, pH 3·0–6·0 and in 3·0–6·5% NaCl. The cellulase secreted by EF85 and EF83 showed good stability at temperatures from 20 to 45°C and pH from 4·5 to 7·0. A commercial inoculant (CLP), a commercial cellulase (CE) and the two cellulolytic strains (EF85 + EF83) were added to whole‐crop corn, sweet sorghum and Napier grass ensiling for 120 days respectively. In Napier grass silage, all inoculants significantly increased lactic acid content and ratio of lactic to acetic acid and decreased pH, butyric acid and ammonia nitrogen contents. The acid detergent fibre and cellulose contents in EF85 + EF83 treatment were significantly lower than those in the other treatments. In whole‐crop corn and sweet sorghum silages, all additives had no significant effect on the fermentation quality, while CE and EF85 + EF83 markedly enhanced cellulose degradation and increased free sugar content.
Conclusion
The combined inoculation of the cellulolytic strain EF85 and EF83 to various forages reduced the fibre content of the resulting silages.
Significance and Impact of the Study
Few studies involved inoculation of silage with Enterococcus species in different forage types. The isolated cellulolytic strains of E. faecalis EF85 and E. faecium EF83 could be a great alternative for commercial inoculants and enzymes in silage production.
Aims
To isolate and identify cellulolytic bacteria from yak rumen and further evaluate the effects of the isolates on the silage quality, structural carbohydrates degradation and cellulose ...convertibility of Napier grass silage.
Methods and Results
Two out of 218 strains were selected based on their most extensive transparent zone and the highest filter paper disintegration rate. The two isolates (JFL12 and JF85) could grow normally at 15–55°C, pH 3·0–7·0 and NaCl (3·0, 6·5%), and were identified as Enterococcus casseliflavus and Enterococcus faecalis by 16S rDNA sequence analysis, respectively. Napier grass was ensiled with no additive control (C), Lactobacillus plantarum (Lp), JFL12, JF85, JFL12 + Lp and JF85 + Lp for 3, 5, 7, 14, 30 and 60 days. All inoculated silages had higher lactic acid content, lower pH, ammonia nitrogen (NH3‐N) and lignocellulose contents than the control silage. Silages treated with JFL12 + Lp and JF85 + Lp had the lowest pH and NH3‐N contents, the highest lactic acid content and lignocellulose degradation among all treatments. The isolates with or without Lp significantly (P < 0·01) increased water soluble carbohydrates (WSC), glucose, fructose and sucrose contents as compared with the control silage. Silages treated with JFL12 + Lp and JF85 + Lp had higher glucose yield and cellulose convertibility than the other silages.
Conclusions
Therefore, the application of isolates (JFL12 and JF85) with Lp had synergistic effects on accelerating the degradation of structural carbohydrates and improving the silage quality.
Significance and Impact of the Study
Napier grass presents difficulty to ensiling due to its low WSC and high structural carbohydrates contents. The screened cellulolytic bacteria could be a candidate strain in improving fermentation quality and structural carbohydrates degradability of ensiled forages.
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