Numerical and experimental investigation on adhesion characteristic of wheel/rail under the third body condition

Author(s):  
H Wang ◽  
WJ Wang ◽  
QY Liu
2021 ◽  
Vol 133 (3) ◽  
Author(s):  
Marilena Di Carlo ◽  
Simão da Graça Marto ◽  
Massimiliano Vasile

AbstractThis paper presents a collection of analytical formulae that can be used in the long-term propagation of the motion of a spacecraft subject to low-thrust acceleration and orbital perturbations. The paper considers accelerations due to: a low-thrust profile following an inverse square law, gravity perturbations due to the central body gravity field and the third-body gravitational perturbation. The analytical formulae are expressed in terms of non-singular equinoctial elements. The formulae for the third-body gravitational perturbation have been obtained starting from equations for the third-body potential already available in the literature. However, the final analytical formulae for the variation of the equinoctial orbital elements are a novel derivation. The results are validated, for different orbital regimes, using high-precision numerical orbit propagators.


Reproduction ◽  
2010 ◽  
Vol 140 (6) ◽  
pp. 865-874 ◽  
Author(s):  
C Viñoles ◽  
B Paganoni ◽  
K M M Glover ◽  
J T B Milton ◽  
D Blache ◽  
...  

We have developed an experimental model in which groups of ewes are simultaneously experiencing the first ovarian follicular wave of their oestrous cycle. We used this ‘first-wave model’ in a 2×2 factorial experiment (ten ewes per group) to study the effect of body condition (BC) and a short-term supplement on follicular dynamics and ovulation rate. The ‘first-wave’ was established by giving ewes three injections of prostaglandin (PG), 7 days apart. The 6-day supplement (lupin grain) began 2 days after the second PG injection and continued until the third. Follicles were studied by ultrasound, and blood was sampled to measure glucose and hormones. The supplement increased (P<0.01) the concentrations of glucose, insulin and leptin, decreased FSH concentrations (P<0.01) and tended to increase oestradiol concentrations (P=0.06). The supplement tended to increase the number of 3 mm follicles (P=0.06). Compared with low-BC ewes, high-BC ewes had more follicular waves (P<0.05), higher concentrations of insulin, leptin and IGF1 (P<0.05) and tended to have higher FSH concentrations (P=0.09). Leptin and insulin concentrations remained high until the end of supplementation in high-BC ewes, whereas they decreased after the third day of supplementation in low-BC ewes. In conclusion, high concentrations of metabolic hormones in fat ewes are associated with the development of more follicular waves. When a supplement is superimposed on this situation, changes in glucose and metabolic hormones allow more follicles to be selected to ovulate.


2002 ◽  
Vol 11 (3) ◽  
pp. 288-293 ◽  
Author(s):  
Gui-Zhen Xu ◽  
Jia-Jun Liu ◽  
Zhong-Rong Zhou

2017 ◽  
Vol 23 (3) ◽  
pp. 420-432 ◽  
Author(s):  
Pavel Krejčí ◽  
Adrien Petrov

The third-body concept is a pragmatic tool used to understand the friction and wear of sliding materials. The wear particles play a crucial role in this approach and constitute the main part of the third-body. This paper aims to introduce a mathematical model for the motion of a third-body interface separating two surfaces in contact. This model is written in accordance with the formalism of hysteresis operators as solution operators of the underlying variational inequalities. The existence result for this dynamical problem is obtained by using a priori estimates established for Faedo–Galerkin approximations, and some more specific techniques such as anisotropic Sobolev embedding theory.


2015 ◽  
Vol 16 (25) ◽  
pp. 168
Author(s):  
Vilma Moreira dos Santos ◽  
Thiago Veloso Vitral ◽  
Alessandra Palhares

<p>O Projeto <strong>Memorial da Imprensa de Uberaba: criação da Hemeroteca Digital do Triângulo Mineiro e Alto Paranaíba </strong>constitui, provavelmente, o maior investimento do estado de Minas Gerais em um projeto individual na área de preservação de acervos documentais históricos. O projeto conta com o financiamento da Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG). Foi concebido e vem sendo executado por parceria firmada entre a Secretaria de Estado de Ciência, Tecnologia e Ensino Superior (SECTES/MG) e a Secretaria de Estado de Cultura (SEC/MG), por meio do Arquivo Público Mineiro (APM), órgão coordenador do Projeto e da Superintendência de Bibliotecas Públicas (SUB). Conta ainda com a participação do Arquivo Público de Uberaba. A partir das diretrizes de regionalização da política cultural do Estado, o resultado principal do projeto será a implantação de um polo de digitalização de acervos documentais históricos no Arquivo Público de Uberaba, que deverá atuar como órgão catalizador e executor de projetos de digitalização nas regiões acima mencionadas. O projeto se fundamenta nas metodologias de organização, preservação e digitalização de acervos documentais preconizadas pelo <strong>Programa Conservação Preventiva em Bibliotecas e Arquivos</strong>, nas recomendações do Conselho Nacional de Arquivos (CONARQ) e nas regras do Código de Catalogação Anglo-americano (CCAA2).</p><p><strong><br /></strong></p><p><strong>Abstract</strong></p><p>“The Printing Press Memorial of Uberaba: the creation of the newspapers´ digital library of Triângulo Mineiro and Alto Paranaíba (Minas Gerais, Brazil)” is probably, the biggest project in the field of historical collections preservation ever funded by the Fundação de Amparo à Pesquisa do Estado de Minas Gerais – FAPEMIG. The project was conceived and has been carried out by the Secretaria de Estado de Ciência, Tecnologia e Ensino Superior, along with the Secretaria de Estado de Cultura, through the participation of the Arquivo Público Mineiro, the coordinating body, and the Superintendência de Bibliotecas Públicas. The<em> </em>Arquivo Público de Uberaba is the third body involved with the implementation of the project. In accordance with the regionalization policies of the State, the main achievement of the project shall be the creation of a digitalization center of historical collections in the Arquivo Público de Uberaba. This institution shall act as a regional agency for the development of digitalization projects in the regions of Triângulo Mineiro and Alto Paranaíba. The project is based on the methodologies of organization, preservation and digitalization of historical collections, recommended by the Programa de Conservação Preventiva em Bibliotecas e Arquivos, the guidelines of the Conselho Nacional de Arquivos<em> </em>(CONARQ) and the Anglo American Cataloguing Rules (AACR2).</p><p><strong>Keywords</strong>: Digitalization of Historical collections; Preservation of Historical Collections; Digital Libraries.</p>


2020 ◽  
Vol 56 (2) ◽  
pp. 179-191
Author(s):  
C. Kamil ◽  
H. A. Dal ◽  
O. Özdarcan ◽  
E. Yoldaş

We present new findings about KIC 8043961. We find the effective temperatures of the components as 6900 ± 200 K for the primary, and 6598 ± 200 K for the secondary, while the logarithm of the surface gravities are found to be 4.06 cm s-2 and 3.77 cm s-2, respectively. Combination of the light curve with the spectroscopic orbit model results leads to a mass ratio of 1.09 ± 0.07 with an orbital inclination of 73.71 ± 0.14 and a semi-major axis of 8.05 ± 0.22 R⨀ . Masses of the primary and secondary components are calculated as 1.379 ± 0.109 M⨀ and 1.513 ± 0.181 M⨀, while the radii are found to be 1.806 ± 0.084 R⨀ and 2.611 ± 0.059 R⨀. In addition, we obtain a considerable light contribution (≈0.54%) of a third body. We compute a possible mass for the third body as 0.778 ± 0.002 M⨀. We find that the primary component exhibits γ Dor type pulsations with 137 frequencies.


1974 ◽  
Vol 124 (581) ◽  
pp. 392-401 ◽  
Author(s):  
P. Gillan ◽  
S. J. Rachman

The investigation had three major aims. We attempted to repeat and extend the findings of the Gelder, Marks and Wolff (1967) study of the comparative efficacy of desensitization and psychotherapy in the treatment of phobic patients. Our second aim was to isolate the effects of various components of desensitization treatment, in the manner employed in laboratory studies of fear-reduction (e.g. Davison, 1968; Rachman, 1965; Rachman, 1968). The third aim was to collect data on the relationships between psychophysiological changes and clinical outcome.


1988 ◽  
Vol 110 (3) ◽  
pp. 517-524 ◽  
Author(s):  
Y. Berthier ◽  
Ch. Colombie´ ◽  
L. Vincent ◽  
M. Godet

Fretting wear and fretting fatigue are governed by the rate of formation of materials (third-bodies) between the initial contact surfaces. Furthermore, the third-bodies must be maintained within the contact. The issue of the race between third-body formation and subsurface damage conditions the effect of fretting on fatigue. That race lasts for only a few hundred or at best a few thousand cycles. Effective third-bodies (or good anti-fretting lubricants) must adhere strongly to the rubbing surfaces, and be able to accommodate at least part of the relative displacement. Great care in the design of test equipment has to be exercised before definitive results on the effect of amplitude and frequency on either fretting fatigue or fretting wear can be obtained for a given contact condition, given materials and given environments.


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