In this study, a numerical triaxial compression test was carried out to investigate the influence of contact friction on the breakage behavior of brittle granular materials using the 3D discrete element method. An commercial software named Particle Flow Code 3D (PFC3D) was applied to undertake these simulations. The cubic numerical model was 30mm wide, 30mm long, and 30mm high, and contained 56...

The girder of self-anchored suspension bridge is subjected to large compression force applied by main cables. So, serious damage of the girder due to breakage of hangers may cause the collapse of the whole bridge. With the time increasing, the hangers may break suddenly for their resistance capacities decrease due to corrosion. Using nonlinear static and dynamic analysis methods and adopting 3D...

Extensive, programmed chromosome breakage occurs during formation of the somatic macronucleus of ciliated protozoa. The cis-acting signal directing breakage has been most rigorously defined in Tetrahymena thermophila, where it consists of a 15-bp DNA sequence known as Cbs, for chromosome breakage sequence. We have identified sequences identical or nearly identical to the T. thermophila Cbs at s...

The damage induced in supercoiled plasmid DNA molecules by low energy (< 1 keV u) singly and doubly charged carbon ions has been investigated as a function of ion exposure. The production of short linear fragments through multiple double strand breakage is indicated and exponential exposure responses for each of the topoisomers are presented. The damage produced by C 2+ is apparent at much lowe...

It is urgent to study the damage mechanism of corn kernels and find ways reducing rate kernel breakage in mechanical threshing. This paper, by studying curves deformation characteristics with different moisture contents, points out brittle fracture low content, clarifies variation law properties contents. The experimental data fatigue load - life contents were described power function equation....

A large number of broken limestone maceheads found at Early Bronze Tel Bet Yerah appears to be the result intentional curation and fragmentation. Our analysis suggests that could function as weapons, but their efficiency dependability were limited. Based on properties, provenance, breakage pattern, dating, we suggest symbolized distribution power in community resistance centralized authority du...

Most people take the stability of chromosomes for granted. Some may imagine metaphase chromosomes lined up like a butterfly collection on a page, reassuringly in order and unchanging. However, evidence that has been accumulating for over half a century indicates that genome stability is a dynamic, not a static, process. In the 1940s natural chromosomes ends, or telomeres, were shown to be speci...

The use of intramedullary nails to treat trochanteric fractures of the femur has increased with the increasing size of the elderly population. The third generation Gamma nail is currently one of the most popular devices for the treatment of trochanteric fractures. Nail breakage is a rare complication, possibly resulting from fatigue fracture of the implant. We present the first reported case of...

The aim of this cross sectional study was to investigate the prevalence of bracket breakage and bond failure amongst orthodontic patients. One hundred and eighty nine patients (78 male & 111 female) undergoing fixed orthodontic treatment at the Department of Orthodontics at Khyber College of Dentistry were included in the study. The patients were divided into two groups namely teens (ages 13-19...

The esperamicins represent a class of antitumor antibiotics characterized by an unusual chemical core structure and extremely potent cytotoxicity. The mechanism by which these drugs produce cytotoxicity was investigated and found to be related to the formation of single- and double-strand DNA breaks. Using five structurally related analogs, we defined a structure-activity relationship for cytot...