Bearing fault diagnosis is imperative for the maintenance, reliability, and durability of rotary machines. It can reduce economical losses by eliminating unexpected downtime in industry due to ...failure of rotary machines. Though widely investigated in the past couple of decades, continued advancement is still desirable to improve upon existing fault diagnosis techniques. Vibration acceleration signals collected from machine bearings exhibit nonstationary behavior due to variable working conditions and multiple fault severities. In the current work, a two-layered bearing fault diagnosis scheme is proposed for the identification of fault pattern and crack size for a given fault type. A hybrid feature pool is used in combination with sparse stacked autoencoder (SAE)-based deep neural networks (DNNs) to perform effective diagnosis of bearing faults of multiple severities. The hybrid feature pool can extract more discriminating information from the raw vibration signals, to overcome the nonstationary behavior of the signals caused by multiple crack sizes. More discriminating information helps the subsequent classifier to effectively classify data into the respective classes. The results indicate that the proposed scheme provides satisfactory performance in diagnosing bearing defects of multiple severities. Moreover, the results also demonstrate that the proposed model outperforms other state-of-the-art algorithms, i.e., support vector machines (SVMs) and backpropagation neural networks (BPNNs).
Research interest in boron nitride nanotubes (BNNTs) has increased after the recent success of large-scale BNNT syntheses using high-temperature-pressure laser ablation or high-temperature plasma ...methods. Nonetheless, there are limits to the application and commercialization of these materials because of the difficulties associated with their fine structural control. Herein, the growth kinetics of BNNTs were systemically studied for this purpose. The growth pressure of the nitrogen feed gas was varied while the growth temperature remained constant, which was confirmed by black body radiation measurements and calculations based on a heat loss model. Changing from the diffusion-limited regime to the supply-limited regime of growth kinetics based on the optimized BNNT synthesis condition afforded the control of the number of BNNT walls. The total amount of BNNTs possessing single and double walls was over 70%, and the BNNT surface area increased to 278.2 m
/g corresponding to small wall numbers and diameters. Taking advantage of the large surface area and high-temperature durability of the material, BNNTs utilized as a recyclable adsorbent for water purification. The efficiency of the BNNTs for capturing methylene blue particles in water was approximately 94%, even after three repetition cycles, showing the potential of the material for application in the filter industry.
This paper proposes a reliable technique for pipeline leak detection using acoustic emission signals. The acoustic emission signal of a pipeline contains leak-related information. However, the noise ...in the signal often obscures the leak-related information, making traditional acoustic emission features, such as count and peaks, less effective. To obtain leak-related features, first, acoustic images were obtained from the time series acoustic emission signals using continuous wavelet transform. The acoustic images (AE images) were the wavelet scalograms that represent the time-frequency scales of the acoustic emission signal in the form of an image. The acoustic images carried enough information about the leak, as the leak-related information had a high-energy representation in the scalogram compared to the noise. To extract leak-related discriminant features from the acoustic images, they were provided as input into the convolutional autoencoder and convolutional neural network. The convolutional autoencoder extracts global features, while the convolutional neural network extracts local features. The local features represent changes in the energy at a finer level, whereas the global features are the overall characteristics of the acoustic signal in the acoustic image. The global and local features were merged into a single feature vector. To identify the pipeline leak state, the feature vector was fed into a shallow artificial neural network. The proposed method was validated by utilizing a data set obtained from the industrial pipeline testbed. The proposed algorithm yielded a high classification accuracy in detecting leaks under different leak sizes and fluid pressures.
The poultry red mite, Dermanyssus gallinae (Mesostigmata: Dermanyssidae), is a major pest that causes great damage to chicken egg production. In one of our previous studies, the management of red ...mites using entomopathogenic fungi was evaluated, and the acaricidal fungus Beauveria bassiana JEF-410 was selected for further research. In this study, we tried to elucidate the pathogenesis of B. bassiana JEF-410 and the defense mechanisms of red mites at a transcriptome level. Red mites collected from a chicken farm were treated with B. bassiana JEF-410. When the mortality of infected red mites reached 50%, transcriptome analyses were performed to determine the interaction between B. bassiana JEF-410 and red mites. Uninfected red mites and non-infecting fungus served as controls. In B. bassiana JEF-410, up-regulated gene expression was observed in tryptophan metabolism and secondary metabolite biosynthesis pathways. Genes related to acetyl-CoA synthesis were up-regulated in tryptophan metabolism, suggesting that energy metabolism and stress management were strongly activated. Secondary metabolites associated with fungal up-regulated DEGs were related to the production of substances toxic to insects such as beauvericin and beauveriolide, efflux pump of metabolites, energy production, and resistance to stress. In red mites, physical and immune responses that strengthen the cuticle against fungal infection were highly up-regulated. From these gene expression analyses, we identified essential factors for fungal infection and subsequent defenses of red mites. These results will serve as a strong platform for explaining the interaction between B. bassiana JEF-410 and red mites in the stage of active infection.
Singleton-Merten syndrome (SMS) is an autosomal-dominant multi-system disorder characterized by dental dysplasia, aortic calcification, skeletal abnormalities, glaucoma, psoriasis, and other ...conditions. Despite an apparent autosomal-dominant pattern of inheritance, the genetic background of SMS and information about its phenotypic heterogeneity remain unknown. Recently, we found a family affected by glaucoma, aortic calcification, and skeletal abnormalities. Unlike subjects with classic SMS, affected individuals showed normal dentition, suggesting atypical SMS. To identify genetic causes of the disease, we performed exome sequencing in this family and identified a variant (c.1118A>C p.Glu373Ala) of DDX58, whose protein product is also known as RIG-I. Further analysis of DDX58 in 100 individuals with congenital glaucoma identified another variant (c.803G>T p.Cys268Phe) in a family who harbored neither dental anomalies nor aortic calcification but who suffered from glaucoma and skeletal abnormalities. Cys268 and Glu373 residues of DDX58 belong to ATP-binding motifs I and II, respectively, and these residues are predicted to be located closer to the ADP and RNA molecules than other nonpathogenic missense variants by protein structure analysis. Functional assays revealed that DDX58 alterations confer constitutive activation and thus lead to increased interferon (IFN) activity and IFN-stimulated gene expression. In addition, when we transduced primary human trabecular meshwork cells with c.803G>T (p.Cys268Phe) and c.1118A>C (p.Glu373Ala) mutants, cytopathic effects and a significant decrease in cell number were observed. Taken together, our results demonstrate that DDX58 mutations cause atypical SMS manifesting with variable expression of glaucoma, aortic calcification, and skeletal abnormalities without dental anomalies.
Identifying line-of-sight (LOS) and non-LOS channel conditions can improve the performance of many wireless applications, such as signal strength-based localization algorithms. For this purpose, ...channel state information (CSI) obtained by commodity IEEE 802.11n devices can be used, because it contains information about channel impulse response (CIR). However, because of the limited sampling rate of the devices, a high-resolution CIR is not available, and it is difficult to detect the existence of an LOS path from a single CSI measurement, but it can be inferred from the variation pattern of CSI over time. To this end, we propose a recurrent neural network (RNN) model, which takes a series of CSI to identify the corresponding channel condition. We collect numerous measurement data under an indoor office environment, train the proposed RNN model, and compare the performance with those of existing schemes that use handcrafted features. The proposed method efficiently learns a nonlinear relationship between input and output, and thus, yields high accuracy even for data obtained in a very short period.
Monochamus alternatus is a major forest pest that spreads pine wilt disease in pine trees as a vector of pine wilt nematodes. Chemical insecticides used as fumigants to control overwintering M. ...alternatus in forests are highly toxic to the environment, so we investigated entomopathogenic fungus Beauveria bassiana ERL836 as an eco-friendly and alternative material to control overwintering M. alternatus. In this work, we evaluated the insecticidal activity of B. bassiana ERL836 against M. alternatus adults, the possibility of fungal colonization on pine tree bark, and finally the control efficacy of fungal pre-treatment on pine tree logs against emerging M. alternatus adults in semi-field and field conditions. M. alternatus adults were killed on the pine tree logs pre-treated with the B. bassiana ERL836. White conidia were observed not only on the surface of the dead adults but also on the pine tree logs, suggesting that the adults were killed by the fungus on the pine. A formulated ERL836 powder treatment on larvae-infested pine logs showed high insecticidal activity against adults, similar to that with the fungal powder suspension treatment, but we demonstrated that using the fungal powder was simpler than using the suspension in field conditions. Even in the field condition, the fungal powder treatment showed high insecticidal activity against M. alternatus adults, which we attribute to its ability to maintain fungal activity for a long time in field conditions by covering the pine tree logs with a film during overwintering. We confirmed that the risk that fungus-infected M. alternatus adults would spread the fungus to other non-target forest insects was low. Thus, even a high-concentration treatment in a specific area is unlikely to transmit the fungus outside that area, so it can be safely used to control this pine wilt nematode vector in forest ecosystems.
Background:
It is still debated whether a degenerative horizontal tear of the medial meniscus should be treated with surgery.
Hypothesis:
The clinical outcomes of arthroscopic meniscectomy will be ...better than those of nonoperative treatment for a degenerative horizontal tear of the medial meniscus.
Study Design:
Randomized controlled trial; Level of evidence, 1.
Methods:
A total of 102 patients with knee pain and a degenerative horizontal tear of the posterior horn of the medial meniscus on magnetic resonance imaging were included in this study between January 2007 and July 2009. The study included 81 female and 21 male patients with an average age of 53.8 years (range, 43-62 years). Fifty patients underwent arthroscopic meniscectomy (meniscectomy group), and 52 patients underwent nonoperative treatment with strengthening exercises (nonoperative group). Functional outcomes were compared using a visual analog scale (VAS) for pain, Lysholm knee score, Tegner activity scale, and patient subjective knee pain and satisfaction. Radiological evaluations were performed using the Kellgren-Lawrence classification to evaluate osteoarthritic changes.
Results:
In terms of clinical outcomes, meniscectomy did not provide better functional improvement than nonoperative treatment. At the final follow-up, the average VAS scores were 1.8 (range, 1-5) in the meniscectomy group and 1.7 (range, 1-4) in the nonoperative group (P = .675). The average Lysholm knee scores at 2-year follow-up were 83.2 (range, 52-100) and 84.3 (range, 58-100) in the meniscectomy and nonoperative groups, respectively (P = .237). In addition, the average Tegner activity scale and subjective satisfaction scores were not significantly different between the 2 groups. Although most patients initially had intense knee pain with mechanical symptoms, both groups reported a relief in knee pain, improved knee function, and a high level of satisfaction with treatment (P < .05 for all values). Two patients in the meniscectomy group and 3 in the nonoperative group with Kellgren-Lawrence grade 1 progressed to grade 2 at the 2-year follow-up.
Conclusion:
There were no significant differences between arthroscopic meniscectomy and nonoperative management with strengthening exercises in terms of relief in knee pain, improved knee function, or increased satisfaction in patients after 2 years of follow-up.
Background
The most relevant time of PM10 exposure to affect airway hyperresponsiveness (AHR) and new development of asthma in school‐aged children is unclear. The aims of this study were to ...investigate the most critical time of PM10 exposure to affect AHR and new diagnosis of asthma from AHR in school‐aged children.
Methods
Elementary schoolchildren (n = 3570) have been enrolled in a nationwide prospective 4‐year follow‐up survey in Korea from 2005 to 2006. Individual annual PM10 exposure was estimated by using an ordinary kriging method from the prenatal period to 7 years of age. AHR at 7 years was defined by a methacholine PC20 ≤8 mg/mL.
Results
PM10 exposure during pregnancy and at 1 year of age showed significant effects on AHR (aOR: 1.694, 95% CI: 1.298‐2.209; and aOR: 1.750, 95% CI: 1.343‐2.282, respectively). PM10 exposure during pregnancy was associated with the risk of a new diagnosis of asthma (aOR: 2.056, 95% CI: 1.240‐3.409), with the highest risk in children with AHR at age 7 (aOR: 6.080, 95% CI: 2.150‐17.195). PM10 exposure in the second trimester was associated with the highest risk of a new diagnosis of asthma in children with AHR at age 7 (aOR: 4.136, 95% CI: 1.657‐10.326).
Conclusions
Prenatal PM10 exposure in the second trimester is associated with an increased risk of a new diagnosis of asthma in school‐aged children with AHR at 7 years. This study suggests that PM10 exposure during a specific trimester in utero may affect the onset of childhood asthma via AHR.
Higher PM10* exposure in the second trimester and AHR# at 7 years showed combined effect on the new diagnosis of asthma at school age (aOR 4.136).
PM10* exposure in the second trimester may affect the development of childhood asthma via AHR#.
*PM10: Particulate matter with an aerodynamic diameter of less than 10 μm.
#AHR: Airway hyperresponsiveness.
The biotransformation of agricultural waste into valuable chemicals represents a promising approach in the field of biorefining. Herein, a general but highly efficient and robust process is reported ...for the production of organic acid from kimchi cabbage waste using lactic acid bacteria. The organic acid produced was tested for efficacy as a biological control agent. Lactobacillus sakei WiKim31 and L. curvatus WiKim38 could efficiently produce organic acids including lactic acid (12.1 and 12.7 g/L), fumaric acid (7.4 and 7.1 g/L), and acetic acid (4.5 and 4.6 g/L) from kimchi cabbage waste (3% substrate loading, w/v) by simultaneous saccharification and fermentation processes for 48 h, and the culture filtrate induced complete mortality of J2s Meloidogyne incognita at 2.5% concentration. These results suggested that lactic acid bacteria L. sakei WiKim31 and L. curvatus WiKim38 can efficiently produce organic acids, and the culture filtrate can be applied as a microbial nematicide.
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