scholarly journals Analysis of damage and failure of ship propulsion shafts

Author(s):  
Guriy Alekseevich Kushner ◽  
Victor Andreevich Mamontov ◽  
Dmitry Aleksandrovich Volkov

The paper highlights the problem of a ship shaft line failure, which entails significant economic losses, because most vessels of the Russian fleet are equipped with a shaft line. A large number of domestic and foreign works are devoted to studying the causes of damage and failures of ship shafting. The complexity of collecting, systematizing and analyzing statistical data on breakdowns and damages of shafting lies in the fact that the data refer to different periods of time, different periods of operation and types of ships, and are also contained in various sources. There has been considered the approach to systematization of modern statistical data on damages and failures of ship shafting elements collected on the basis of defect-technological lists of the Astrakhan shipyards and from other sources. Information on breakdowns of ships, their elements and ship shaft lines within 2010 - 2019 provided by the Russian River Register of Shipping is given. The analysis of accidents on ships of the class of the Russian Maritime Register of Shipping. The places of occurrence and the nature of the propeller shaft cracks have been established, which makes it possible to assess the nature and magnitude of the destructive loads, as well as the real safety margins. The general classification of the location of the propeller shaft cracks in the order of the frequency of their occurrence is given. There have been shown the results of the analysis of defect-technological lists, which make it possible to establish the causes of ship shafting failures, which led to emergency repair, and the most common defects identified during the scheduled dock repair of ships. The influence of the diameter of propeller shafts on the nature and size of defects, as well as the frequency of their manifestation, is estimated. Based on the results of the analysis, certain measures have been proposed to reduce the number of accidents in shafting of projected vessels, and the most promising directions for improving the already developed structures of shafting in operation are outlined. The results of the analysis are in addition to the ongoing research and development work to improve the reliability of ship power systems.

2009 ◽  
pp. 123-129
Author(s):  
Yu. Golubitsky

The article considers business practices of Moscow small industry in the XIX century, basing upon physiological sketches of N. Polevoy and I. Kokorev, statistical data and the classification of professions are also presented. The author claims that the heroes of the analyzed sketches are the forefathers of Moscow small businesses and shows what a deep similarity their occupations and a way of life bear to the present-day routine existence of small enterprises.


Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 241
Author(s):  
Joon Moh Park ◽  
Jachoon Koo ◽  
Se Won Kang ◽  
Sung Hee Jo ◽  
Jeong Mee Park

Rhodococcus fascians is an important pathogen that infects various herbaceous perennials and reduces their economic value. In this study, we examined R. fascians isolates carrying a virulence gene from symptomatic lily plants grown in South Korea. Phylogenetic analysis using the nucleotide sequences of 16S rRNA, vicA, and fasD led to the classification of the isolates into four different strains of R. fascians. Inoculation of Nicotiana benthamiana with these isolates slowed root growth and resulted in symptoms of leafy gall. These findings elucidate the diversification of domestic pathogenic R. fascians and may lead to an accurate causal diagnosis to help reduce economic losses in the bulb market.


2019 ◽  
Vol 2 (S1) ◽  
Author(s):  
Friederike Wenderoth ◽  
Elisabeth Drayer ◽  
Robert Schmoll ◽  
Michael Niedermeier ◽  
Martin Braun

Abstract Historically, the power distribution grid was a passive system with limited control capabilities. Due to its increasing digitalization, this paradigm has shifted: the passive architecture of the power system itself, which includes cables, lines, and transformers, is extended by a communication infrastructure to become an active distribution grid. This transformation to an active system results from control capabilities that combine the communication and the physical components of the grid. It aims at optimizing, securing, enhancing, or facilitating the power system operation. The combination of power system, communication, and control capabilities is also referred to as a “smart grid”. A multitude of different architectures exist to realize such integrated systems. They are often labeled with descriptive terms such as “distributed,” “decentralized,” “local,” or “central." However, the actual meaning of these terms varies considerably within the research community.This paper illustrates the conflicting uses of prominent classification terms for the description of smart grid architectures. One source of this inconsistency is that the development of such interconnected systems is not only in the hands of classic power engineering but requires input from neighboring research disciplines such as control theory and automation, information and telecommunication technology, and electronics. This impedes a clear classification of smart grid solutions. Furthermore, this paper proposes a set of well-defined operation architectures specialized for use in power systems. Based on these architectures, this paper defines clear classifiers for the assessment of smart grid solutions. This allows the structural classification and comparison between different smart grid solutions and promotes a mutual understanding between the research disciplines. This paper presents revised parts of Chapters 4.2 and 5.2 of the dissertation of Drayer (Resilient Operation of Distribution Grids with Distributed-Hierarchical Architecture. Energy Management and Power System Operation, vol. 6, 2018).


Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 915
Author(s):  
Diding Suhandy ◽  
Meinilwita Yulia

As a functional food, honey is a food product that is exposed to the risk of food fraud. To mitigate this, the establishment of an authentication system for honey is very important in order to protect both producers and consumers from possible economic losses. This research presents a simple analytical method for the authentication and classification of Indonesian honeys according to their botanical, entomological, and geographical origins using ultraviolet (UV) spectroscopy and SIMCA (soft independent modeling of class analogy). The spectral data of a total of 1040 samples, representing six types of Indonesian honey of different botanical, entomological, and geographical origins, were acquired using a benchtop UV-visible spectrometer (190–400 nm). Three different pre-processing algorithms were simultaneously evaluated; namely an 11-point moving average smoothing, mean normalization, and Savitzky–Golay first derivative with 11 points and second-order polynomial fitting (ordo 2), in order to improve the original spectral data. Chemometrics methods, including exploratory analysis of PCA and SIMCA classification method, was used to classify the honey samples. A clear separation of the six different Indonesian honeys, based on botanical, entomological, and geographical origins, was obtained using PCA calculated from pre-processed spectra from 250–400 nm. The SIMCA classification method provided satisfactory results in classifying honey samples according to their botanical, entomological, and geographical origins and achieved 100% accuracy, sensitivity, and specificity. Several wavelengths were identified (266, 270, 280, 290, 300, 335, and 360 nm) as the most sensitive for discriminating between the different Indonesian honey samples.


Leonardo ◽  
2009 ◽  
Vol 42 (5) ◽  
pp. 439-442 ◽  
Author(s):  
Eduardo R. Miranda ◽  
John Matthias

Music neurotechnology is a new research area emerging at the crossroads of neurobiology, engineering sciences and music. Examples of ongoing research into this new area include the development of brain-computer interfaces to control music systems and systems for automatic classification of sounds informed by the neurobiology of the human auditory apparatus. The authors introduce neurogranular sampling, a new sound synthesis technique based on spiking neuronal networks (SNN). They have implemented a neurogranular sampler using the SNN model developed by Izhikevich, which reproduces the spiking and bursting behavior of known types of cortical neurons. The neurogranular sampler works by taking short segments (or sound grains) from sound files and triggering them when any of the neurons fire.


Author(s):  
V.G. Shifrin ◽  
◽  
N.V. Limarenko ◽  
D.V. Trinz ◽  
D.S. Inozemtsev ◽  
...  

This article discusses the problems of the influence of electromagnetic compatibility (EMC) violations of electrical and electronic devices on the surrounding ecosystems. The analysis is carried out and the classification of EMC violations is given, the causes of the compatibility violation are examined, and the economic losses and the negative environmental impact, as a consequence of the considered violations, are analyzed. A classification and generalization of methods to minimize the negative consequences of EMC violations was carried out, criteria for reducing economic losses were considered, methods for preventing and preventing EMC violations of various power and electronic devices were classified. The methods of monitoring the compatibility of devices are considered and recommendations are given for observing the necessary safety and control requirements.


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