Two methionine tRNAs from yeast mitochondria have been purified. The mitochondrial initiator tRNA has been identified by formylation using a mitochondrial enzyme extract. E. coli transformylase however, does not formylate the yeast mitochondrial initiator tRNA. The sequence was determined using both 32P-in vivo labeled and 32P-end labeled mt tRNAf(Met). This tRNA, unlike N. crassa mitochondrial...

The buckling of graphene sheets on substrates can significantly degrade their performance in materials and devices. Therefore, a systematic investigation on the buckling behavior of monolayer graphene sheet/substrate systems is carried out in this paper by both molecular mechanics simulations and theoretical analysis. From 70 simulation cases of simple-supported graphene sheets with different s...

In this paper, molecular dynamics simulations MDS are performed on single-walled carbon nanotubes SWCNTs in order to study the effects of chirality on their buckling behavior under axial compression. In the MDS, the Tersoff-Brenner potential is used to describe the interaction of carbon atoms in the SWCNTs. The sensitivity of the buckling strains and buckling modes with respect to the chirality...

This paper presents a new theory for the lateral buckling of web-tapered I-beams. Linear analysis is first conducted by taking account into the tapering effects of web-tapered I-beams, where the deformation compatibilities of the two flanges and web are considered in terms of the basic assumptions of thin-walled members. Subsequently, the total potential for the lateral buckling analysis of web...

We investigate the cross-sectional buckling of multi-concentric tubular nanomaterials, which are called multiwalled carbon nanotubes (MWNTs), using an analysis based on thin-shell theory. MWNTs under hydrostatic pressure experience radial buckling. As a result of this, different buckling modes are obtained depending on the inter-tube separation d as well as the number of constituent tubes N and...

Mechanical buckling usually means catastrophic failure in structural mechanics systems. However, controlled buckling of thin films on compliant substrates has been used to advantage in diverse fields such as micro-/ nanofabrication, optics, bioengineering, and metrology as well as fundamental mechanics studies. In this Feature Article, a mechanical buckling model is presented, which sprang, in ...

This paper presents a molecular dynamics (MD) study on the thermally induced buckling of pre-compressed carbon nanotubes (CNTs) using AIREBO interatomic potential. CNTs are compressed at a certain ratio of their critical buckling strain and then undergo a uniform temperature rise. In order to evaluate the chirality effects, armchair and zigzag CNTs are investigated. The results demonstrate that...

This paper addresses testing of compressed structures, such as shells, that exhibit catastrophic buckling and notorious imperfection sensitivity. The central concept is the probing of a loaded structural specimen by a controlled lateral displacement to gain quantitative insight into its buckling behaviour and to measure the energy barrier against buckling. This can provide design information ab...

Purpose: The aims of the present study are to correlate the ISQ values, registered by the Osstell ISQ system, with the insertion torque during the placement of the implant, and to assess the influence of the thread initiator on the ISQ values and on the insertion torque. Materials and methods: 140 rough surface implants screw-shaped implants, placed in 10 bovine ribs, were assigned to Group A (...

Corrugated web girders represent a new structural system emerged in the past two decades. The girder’s flanges provide the flexural strength of the girder with no contribution from the corrugated web which provides the girder’s shear capacity. Failure of the web occurs by steel yielding, web buckling or interactively between them. Lateral torsion and local flange buckling of corrugated web gird...