Reliability Measurement

After calculation of reliability, the system is constructed. It is important to measure the calculated useful life of the system. Reliability measurement tests can also be used for the converter operating in service to estimate the remaining useful life of the converter. In this chapter, various methods of tests for this goal are presented. The main approach is accelerated aging test that reduce the time needed for failure in a system. In this method, the device is tested under conditions beyond its defined nominal specifications. Limits for this harsh condition is determined based on the calculations which are presented in chapters 3 and 4. If a problem occurs in implementing and operating process of the converter, accelerated aging tests decrease the time to failure. Theoretical concept of accelerated aging tests is described. Standard tests of electric power converters are presented. Equipment and test chambers for standard tests are explained. These tests contain all four various failure factors which are presented in chapter 2. Sample industrial examples are presented to demonstrate the procedure of the tests. Some accelerated aging tests may lead to destruction of the converter. Difference between destructive and nondestructive tests is presented. Sample devices after accelerated aging tests are shown. Measuring devices for system parameter identification are introduced. Various types of tests are expressed in details for some of the most important tests like electric withstand tests.

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Xuan Wang

Cables in power generation and delivery are under high thermal stress cycles. Such high temperature can lead to cable insulation degradation, which will reduce the projected lifetime. Existing methods mainly focus on cable fault detection or insulation degradation mechanism. There is no existing tools for diagnosing the insulation degradation level and predicting the remaining useful life of the cable. The goal of my Ph.D. research is to develop reflectometry and data based approaches to monitor the health status of cables. The research will be conducted in three steps: (1) development of reflectometry based method to monitor the cable insulation degradation; (2) feature extraction and cable insulation degradation dynamic modeling based on the accelerated aging test data; (3) development of risksenstive particle filtering based fault diagnosis and prognosis algorithms for cable degradation; and (4) verification and validation the proposed solution with new experiment data and comparison with existing approaches.


2013 ◽  
Vol 35 (4) ◽  
pp. 449-456 ◽  
Author(s):  
Daniele Nerling ◽  
Cileide Maria Medeiros Coelho ◽  
Rubens Onofre Nodari

The physiological quality is based on the genotype and may be accompanied since the first stages of selection through the study of genetic diversity. The purpose of this study was to evaluate the parental genetic contribution in the seed physiological quality in corn intervarietal crossbreeds. The intervarietal crossbreeds were performed using landraces genotypes, open pollinated varieties and commercial hybrids. The seeds obtained from the crossbreed, their equivalents and parentals were evaluated regarding their water percentage, germination, germination speed rate, accelerated aging, field emergence and electrical conductivity. The seeds obtained in the crossbreed are viable and vivid with heterosis when compared with the parentals. The accelerated aging test was more effective for selecting the strongest genotypes. The canonical variables were useful to group the genotypes that presented similar physiological characteristics. The genotypes MPA 01 x Pixurum 05, MPA 01 x AS1565, MPA 01 x SJC5886, SJC5886 x Pixurum 05 and Fundacep 35 x SCS 154 Fortuna were the best crossbreeds regarding the production of better physiological quality seeds.


2018 ◽  
Vol 12 (03) ◽  
pp. 444-448
Author(s):  
Andréa Bicca Noguez Martins ◽  
◽  
Caroline Jácome Costa ◽  
Fernanda da Motta Xavier ◽  
André Pich Brunes ◽  
...  

2018 ◽  
Vol 40 (1) ◽  
pp. 44-51
Author(s):  
Thaís D’Avila Rosa ◽  
Ariele Paula Nadal ◽  
Henrique Roberto Maldaner ◽  
Vanessa Nogueira Soares ◽  
Gizele Ingrid Gadotti ◽  
...  

Abstract: The objective of this study was to determine adequate conditions of water volume, seed quantity and immersion period to perform the electrical conductivity test, and to analyze the parameters of the accelerated aging test and its correlation with the the physiological potential of amaranth seeds. Five lots of amaranth seeds (Amaranthus cruentus), cultivar BRS Alegria, were used. The initial evaluation of the quality of these lots comprehended the following tests: water content, germination, first germination count, accelerated aging (traditional method, and modified versions, using unsaturated and saturated saline solution for the periods of 24, 48 and 72 h), electrical conductivity in different periods (2, 4, 6, 8 and 24 h), different quantities of water (25, 50 and 75 mL), different seed quantities (100 and 150), and field emergence. It could be concluded that the accelerated aging test at 41 °C, for 72 h, using unsaturated NaCl solution was efficient in the classification of amaranth seed lots in levels of vigor. The electrical conductivity test performed for 8 hours with 25 mL of water and 100 seeds was efficient in the classification of amaranth seeds as to their physiological potential.


Nativa ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 313 ◽  
Author(s):  
Aline Krolow Soares ◽  
Roberto Lessa Pereira ◽  
Pedro Henrique Gonzalez de Cademartori ◽  
Henrique Weber Dalla Costa ◽  
Darci Alberto Gatto

O presente estudo teve como objetivo investigar a resistência ao intemperismo artificial de quatro revestimentos aplicados nas madeiras de duas espécies florestais. Para tal, foram utilizadas seis árvores de Eucalyptus grandis e três árvores de Tetrorchidium rubrivenium as quais foram desdobradas para confecção de 50 amostras para cada espécie, com dimensões de 5,0x7,0x1,0cm (largura, comprimento e espessura, respectivamente). A superfície das madeiras foi revestida com quatro acabamentos: polistein, verniz marítimo, tinta branca base óleo e tinta branca base água. As amostras sem revestimento e revestidas foram submetidas ao ensaio de envelhecimento acelerado durante 480 horas. A resistência ao intemperismo artificial foi avaliada por meio das modificações colorimétricas e morfológicas ao longo da exposição das madeiras e em função da molhabilidade superficial. Os principais resultados mostraram que a superfície das madeiras  tendeu a tons opacos após exposição de 480 horas. Foi observado que os revestimentos não evitaram o aumento da molhabilidade superficial. Após todo o período de exposição, as madeiras não apresentaram modificações morfológicas tais como rachaduras e descascamento dos revestimentos, o que denota importante característica de proteção à madeira.Palavras-chave: Eucalyptus, canemaçu, modificação da superfície, envelhecimento acelerado, durabilidade da madeira. ARTIFICIAL WEATHERING OF FOUR COATINGS APPLIED ON WOODS OF TWO FOREST SPECIES ABSTRACT:The present study aimed to investigate the resistance to artificial weathering of four coatings applied on wood from two forest species. Six trees of Eucalyptus grandis and three trees of Tetrorchidium rubrivenium were cut to produce 50 wood samples for each species with dimensions of 5.0x7.0x1.0 cm (width, length and thickness, respectively). Wood surface was coated with four finishing products: polistein, marine varnish, oil-based white paint and water-based white paint. The uncoated and coated wood samples were subjected to accelerated aging test for 480h. The artificial weathering resistance was evaluated by color changes and surface wettability. The main results showed the coated woods tend to opaque tones after the exposure for 480h. The coatings did not avoid the increase of the surface wettability. After the exposure, both woods did not present morphological changes, such as cracks and peeling into the coatings, which represent relevant characteristics for wood protection.Keywords: Eucalyptus, canemaçu, surface modification, accelerated aging, wood durability. DOI:


2019 ◽  
Vol 2 (3) ◽  
pp. 7
Author(s):  
Dyah Priandini ◽  
Muhamad Rahmad Suhartanto ◽  
Abdul Qadir

Development of papaya fruit production is influenced by the availability of seed quality. High seed quality is maintained during seed storage. Estimation of vigor in relation to storability can be detected by accelerated aging test. This research aims to develop physicall accelerated aging test by, 1)determine the impact of physical accelerated aging on vigor and viability parameters on papaya seed variety Callina and Sukma, 2) determine the levels of seed moisture content and effective period of physicall accelerated aging to predict vigor of papaya seed. This research was conducted at the Laboratory of Seed Science and Technology and Green House Leuwikopo, Department of Agronomy and Horticulture, IPB in January-May 2016 using a randomized complete block design with three replications. Seeds aged by the aging equipment MPC IPB 77-1 MMM. The results showed that the aging time decreased germination value in papaya seed variety Callina and Sukma with equation y=-0.1389x3+3.3333x2–25.25x+81.5 and y=0.0171x3+0.2028x2-9.9956x+81.095. Effective imbibition is 96 hour with moisture content 63-70% in both varieties. The effective of aging time treatment at 0x4, 1x4, 2x4, 3x4, dan 4x4 minutes.Keywords:imbibition, moisture content, viability, vigor


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