Complex Decay Prediction of Marine Machinery Using Multilabel SVM

In this article, a multilabel support vector machine (SVM)-based approach is investigated to address the simultaneous decay detection of the marine propulsion system. To verify the performance of the algorithm, we perform some experiments using a simulation dataset from a real-data validated numerical simulator of a Frigate. In particular, we try to train the model without simultaneous decay data, considering the great difficulty of obtaining simultaneous decay data in practice. The experimental results show that the proposed approach can identify the complex decay modes of the marine propulsion system effectively using only simple decay data in the training process. Introduction The propulsion system is considered to be the “heart” of a marine ship (Li et al. 2019a). Its safety and reliability are critical to the regular operation of the ship (Bayer et al. 2018; Cheliotis & Lazakis, 2018; Lazakis et al. 2016). However, performance decay may occur to the propulsion system due to the high humidity and high salt characteristics of the marine environment (Fang et al. 2018; Kang et al. 2019; Wang et al. 2019). The decay modes can be divided into single decay and simultaneous decay. Single decay indicates a simple decay mode that only one kind of decay occurs at a time, and simultaneous decay indicates a complex decay mode that multiple decays occur at the same time. To improve the safety and reliability of the marine propulsion system, researchers have proposed many related approaches from the perspective of fault diagnosis.

Spontaneous Generation of Voltage in Sm0.55Sr0.45MnO3 and La0.75Ba0.25MnO3 Single Crystals

In Sm0.55Sr0.45MnO3single crystals, grown by the floating-zone method with the cooling in oxygen, has been observed the spontaneous generation of voltage (SGV). Its maximum reaches 60 μV and occurs in the temperature range where simultaneous decay of the CE-type antiferromagnetic order and the charge order take place in some clusters. The SGV peak becomes lower by about 45% if magnetic field 14.2 kOe applied. Also we observed the SGV in La0.75Ba0.25MnO3single crystals. Maximum value of SGV occurs in a vicinity of the Curie temperature. The SGV value seems to be almost independent from the cooling or heating rate and crystallographic direction, but in La0.75Ba0.25MnO3it is smaller than in Sm0.55Sr0.45MnO3by an order of magnitude. La0.75Ba0.25MnO3compound contains ferromagnetic clusters, in which the electrical charges are localized according to gain in thes-dexchange energy. They are distributed in the paramagnetic lattice, impoverished of an electrical charge. It is shown that SGV stems from the presence of regions with different electrical charges in both samples.

Characterization of Schinopsis Haenkeana wood Decayed by Phellinus Chaquensis (Basidiomycota, Hymenochaetales)

Schinopsis haenkeana is a native tree to the Chaco Serrano Forests in Argentina. The white-rot fungus Phellinus chaquensis degrades its wood, causing a whiterot type of decay. The objective of this study was to investigate the structural alterations caused by P. chaquensis in S. hankeana decayed naturally and in vitro. Sound living branches with decay and basidiocarps of P. chaquensis were sampled from the field and in vitro decay tests were performed according to the ASTM D-2017-81 standard method. Naturally decayed branches exhibited an innermost discolored zone with white-rot decay and an outer yellowish-white portion of sound sapwood. Using LM and SEM, degraded tissue displayed diagnostic characters of selective delignification and simultaneous decay. Findings indicate that P. chaquensis causes a mottled pattern of decay (selective delignification plus simultaneous decay) in S. haenkeana wood. Other features such as accumulation of extractives, profuse deposition of crystals and tyloses, typical ofSchinopsis spp. heartwood, were additionally observed. In laboratory degraded material, signs of selective delignification and incipient stages of simultaneous decay were noticeable only microscopically. Chemical analysis revealed an oxidative alteration of aromatic moieties in naturally decayed samples which might be related to the accumulation of phenols as a response to fungal attack when compared to sound samples. Naturally degraded sapwood exhibits anatomical and chemical modifications that indicate the development of discolored wood derived from the host-pathogen interaction.

A+U-Rich Instability Elements Differentially Activate 5′-3′ and 3′-5′ mRNA Decay

ABSTRACT The A+U-rich elements (or AREs) are cis-acting sequences that activate rapid mRNA decay, yet the overall polarity of this process is unknown. The current study describes an unbiased approach to this using the Invader RNA assay (Third Wave Technologies, Inc.) to quantify the decay of each of the three exons of human β-globin mRNA without added instability elements or with the AREs from c-fos or granulocyte-macrophage colony-stimulating factor (GM-CSF) mRNA in the 3′ untranslated region. Each of these genes under tetracycline operator control was stably transfected into cells, and β-globin mRNA was quantified with exon-specific probes following transcription termination. There was little overall evidence for polarity in stable mRNA decay. Adding the c-fos ARE activated rapid and simultaneous decay from both ends of the mRNA. In contrast, the GM-CSF ARE activated decay primarily from the mRNA 5′ end. These data were supported by reciprocal RNA interference knockdowns, and we present evidence that the 5′-3′ and 3′-5′ decay pathways are functionally linked.

PATTERNS OF DECAY CAUSED BY PYCNOPORUS SANGUINEUS AND GANODERMA LUCIDUM (APHYLLOPHORALES) IN POPLAR WOOD

Populus deltoides clones are widely planted in Argentina, in a region called “Paraná River Delta”. In this site, Pycnoporus sanguineus and Ganoderma lucidum (Aphyllophorales) cause white-rot decay in both living and felled poplar trees. The purpose of this work was to estimate, through laboratory decay tests, the ability of both fungi to degrade poplar wood and to describe the patterns of decay using light and scanning electron microscopy. Two exposure times were analyzed: 75 and 150 days. The percent weight loss produced by both fungal strains was similar for both exposure periods (c. 50–60% of wood mass) but microscopic observations showed there were different patterns of decay. Samples inoculated with P. sanguineus showed a selective delignification, whereas those inoculated with G. lucidum exhibited a combination of simultaneous decay and selective delignification. Separation among cells was the main diagnostic feature for selective decay. By contrast, the presence of erosion troughs, cell wall thinning, bore holes, rounded pit erosion and erosion channels were diagnostic for the simultaneous type of decay.

Anatomical Study of the Decay Caused by the White-Rot Fungus Trametes Trogii (Aphyllophorales) in Wood of Salix and Populus

Different stages of decay caused in vitro by Trametes trogii in Salix sp. and Populus sp. wood are described. Anatomical features are reported in three stages of this process. Decay progressed in a different pattern in both species studied. In Populus sp. T. trogii caused a combination of selective delignification and simultaneous decay within the same substrate. In advanced stages wood blocks exhibited large empty holes and a spongy structure. In Salix sp. a simultaneous white-rot decay took place. Only vessels remained and the residual white-rotted wood developed a stringy appearance.

In vitro decay studies of selective delignification and simultaneous decay by the white rot fungi Ganoderma lucidum and G. tsugae

The in vitro wood decay abilities of Ganoderma lucidum (W. Curt.: Fr.) Karst. and G. tsugae Murr. were studied using the following woods in agar block decay chambers: Vitis vinifera L., Quercus hypoleucoides A. Camus, Prosopis velutina Woot., Abies concolor (Gord. & Glend.) Lindl. ex. Hildebr., and Pseudotsuga menziesii (Mirb.) Franco. Grape wood lost the most weight while mesquite the least. Ganoderma lucidum isolates generally caused greater weight loss of all woods than did G. tsugae isolates. The range of the percent weight losses varied with the wood. Both Ganoderma species caused simultaneous decay in all woods. However, chemical analyses of the decayed blocks indicated that selective delignification by both species also occurred in grape and white fir blocks. Chemical analysis of the decayed oak blocks indicated the percentages of lignin and holocellulose were not statistically different from the controls. However, there was a trend towards delignification. The analyses of the Douglas-fir blocks indicated only simultaneous decay. Scanning electron microscopy demonstrated selective delignification and simultaneous decay of all woods tested. However, the extent of the delignification differed among the wood species. Delignification appeared mainly in areas of tracheids or fiber tracheids, while the rays were simultaneously decayed.