Push-Pull Fatigue Strength of Mild Steel at Very High Frequencies of Stress Up to 100 kc/s

1965 ◽  
Vol 87 (4) ◽  
pp. 857-864 ◽  
Author(s):  
M. Kikukawa ◽  
K. Ohji ◽  
K. Ogura

Previous investigations of frequency on fatigue strength are briefly reviewed in this paper. New resonant-type push-pull fatigue testing machines at 50 and 100 kc/s were also developed by using a ferrite magnetostrictive vibrator. By using these machines, as well as previously developed high and low-frequency push-pull fatigue testing machines, the influence of stress frequency on fatigue limit of two carbon steels was determined at frequencies ranging from 40 to 100,000 c/s. The fatigue limit was found to increase monotonically with increasing frequency. No peak in the value of the fatigue limit was observed at frequencies up to 100,000 c/s.

1930 ◽  
Vol 68 (401) ◽  
pp. 556-559
Author(s):  
C.L. Fortescue ◽  
L.A. Moxon

1984 ◽  
Vol 160 (1) ◽  
pp. 1-11 ◽  
Author(s):  
M Slaoui ◽  
O Leo ◽  
J Marvel ◽  
M Moser ◽  
J Hiernaux ◽  
...  

We have shown that, by suitable idiotypic manipulation, BALB/c mice can express the major cross-reactive idiotype (CRI) of A/J mice in response to azophenylarsonate (Ars). In order to know if the CRIA idiotype is present in the potential repertoire of BALB/c before any intentional selection, we used polyclonal activation in vitro and limiting dilution analysis. The readout was done with two monoclonal anti-CRIA antibodies that recognize distinct idiotopes on a CRIA+ A/J germline-encoded monoclonal antibody. We studied the frequency of CRIA+ lipopolysaccharide (LPS)-reactive cells in the spleens of nonimmune and immune A/J mice and in the spleens of naive and manipulated (i.e., producing CRIA+ antibodies) BALB/c mice. A/J and BALB/c naive individuals presented very high frequencies of Ars-specific B cells while the frequency of CRIA+ B cells was only a minor subset (0.5%) of the total Ars-specific subset in the two strains. When A/J mice were immunized with Ars-keyhole limpet hemocyanin, a clear preferential expansion of the CRIA+ minor subset of A/J mice was observed (100x). No such enhancement was observed in BALB/c mice similarly treated. Manipulated BALB/c mice presented a higher frequency of CRIA+ anti-Ars B cells than naive or antigen-immunized BALB/c individuals.


2020 ◽  
Vol 10 (1) ◽  
pp. 394-400 ◽  
Author(s):  
I. M. W. Ekaputra ◽  
Rando Tungga Dewa ◽  
Gunawan Dwi Haryadi ◽  
Seon Jin Kim

AbstractThis paper presents the reliability estimation of fatigue strength of the material used for crank throw components. The material used for crank throw components is forged S34MnV steel and subsequently heat-treated by normalising and tempering. High cycle fatigue testing under fully reversed cycling (R = −1) was performed to determine the fatigue limit of the material. The staircase test method is used to obtain accurate values of the mean fatigue limit stress until a number of cycles up to 1E7 cycles. Subsequently, the fatigue test results depend strongly on the stress step and are evaluated by the Dixon-Mood formula. The values of mean fatigue strength and standard deviation predicted by the staircase method are 282 MPa and 10.6MPa, respectively. Finally, the reliability of the design fatigue strength in some selected probability of failure is calculated. Results indicate that the fatigue strength determined from accelerated staircase test is consistent with conventional fatigue testing. Furthermore, the proposed method can be applied for the determination of fatigue strength and standard deviation for design optimisation of S34MnV steel.


Genetics ◽  
1998 ◽  
Vol 148 (1) ◽  
pp. 267-275
Author(s):  
Isabelle Busseau ◽  
Sophie Malinsky ◽  
Maria Balakireva ◽  
Marie-Christine Chaboissier ◽  
Danielle Teninges ◽  
...  

Abstract I factors in Drosophila melanogaster are non-LTR retrotransposons similar to mammalian LINEs. They transpose at very high frequencies in the germ line of SF females resulting from crosses between reactive females, devoid of active I factors, and inducer males, containing active I factors. The vermilion marked IviP2 element was designed to allow easy phenotypical screening for retrotransposition events. It is deleted in ORF2 and therefore cannot produce reverse transcriptase. IviP2 can be mobilized at very low frequencies by actively transposing I factors in the germ line of SF females. This paper shows that IviP2 can be mobilized more efficiently in the germ line of strongly reactive females in the absence of active I factors, when it is trans-complemented by the product of ORF2 synthesized from the hsp70 heat-shock promoter. This represents a promising step toward the use of marked I elements to study retrotransposition and as tools for mutagenesis.


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