Literature survey

About: Literature survey is a research topic. Over the lifetime, 15372 publications have been published within this topic receiving 459196 citations.

Factors that affect the fatigue life of rubber: A literature survey

Abstract: Many factors are known to influence the mechanical fatigue life of rubber components. Four major categories of factors are reviewed here: the effects of mechanical loading history, environmental effects, effects of rubber formulation, and effects due to dissipative aspects of the constitutive response of rubber. For each category, primary factors are described, and existing literature is presented and reviewed. Rubber's fatigue behavior is extremely sensitive to both the maximum and minimum cyclic load limits. Other aspects of the mechanical load history are also discussed, including the effects of static loaded periods (“annealing”), load sequence, multiaxiality, frequency, and loading waveform. Environmental factors can affect both the short and long term fatigue behavior of rubber. The effects of temperature, oxygen, ozone, and static electrical charges are reviewed. A great range of behavior is available by proper manipulation of formulation and processing variables. Effects of elastomer type...

Pathological studies on sarcoidosis autopsy. I. Epidemiological features of 320 cases in Japan.

Abstract: Three hundred and twenty autopsy cases of sarcoidosis during a 32 year period were collected from the Annuals of the Pathological Autopsy Cases in Japan, published yearly since 1958, and from a literature survey. A statistical analysis of these reviewed autopsy cases was carried out on the epidemiological features of the disease and on the causes of death. The proportion of sarcoidosis autopsy cases relative to the total autopsy cases had increased during this 32 year period. The increase of sarcoidosis autopsies during this period was chiefly due to the increase in aged females; the total number of female cases was approximately two times more than that of males. As over half of the total cases had only a pathological diagnosis and not a clinical diagnosis for sarcoidosis, the actual morbidity from sarcoidosis that was estimated from the autopsy data and corrected by autopsy rate was over five times higher than that of the clinically recognized cases. Age and sex distribution of these cases peaked in the thirties for both sexes, while another very high peak was noted in females over 50 years of age. In approximately 60% of the sarcoidosis autopsies, the cause of death related to sarcoid lesions in the heart, lung or nervous system, the majority of which involved cardiac sarcoidosis. In the remaining 40% of the cases, the cause of death was from non-sarcoidosis diseases.

Backward-Facing Step Flows for Various Expansion Ratios at Low and Moderate Reynolds Numbers

Abstract: This paper is concerned with the behavior of flows over a backward-facing step geometry for various expansion ratios H/h=1.9423, 2.5 and 3.0. A literature survey was carried out and it was found that the flow shows a strong two-dimensional behavior, on the plane of symmetry, for Reynolds numbers ReD=ρUbD/μ below approximately 400 (Ub= bulk velocity and D= hydraulic diameter). In this Reynolds number range, two-dimensional predictions were carried out to provide information on the general integral properties of backward-facing step flows, on mean velocity distributions and streamlines. Information on characteristic flow patterns is provided for a wide Reynolds number range, 10−4≤ReD≤800. In the limiting case of ReD→0, a sequence of Moffatt eddies of decreasing size and intensity is verified to exist in the concave corner also at ReD=1. The irreversible pressure losses are determined for various Reynolds numbers as a function of the expansion ratio. The two-dimensional simulations are known to underpredict the primary reattachment length for Reynolds numbers beyond which the actual flow is observed to be three-dimensional. The spatial evolution of jet-like flows in both the streamwise and the spanwise direction and transition to three-dimensionality were studied at a Reynolds number ReD=648. This three-dimensional analysis with the same geometry and flow conditions as reported by Armaly et al. (1983) reveals the formation of wall jets at the side wall within the separating shear layer. The wall jets formed by the spanwise component of the velocity move towards the symmetry plane of the channel. A self-similar wall-jet profile emerges at different spanwise locations starting with the vicinity of the side wall. These results complement information on backward-facing step flows that is available in the literature.

A musculoskeletal model for the lumbar spine.

Abstract: A new musculoskeletal model for the lumbar spine is described in this paper. This model features a rigid pelvis and sacrum, the five lumbar vertebrae, and a rigid torso consisting of a lumped thoracic spine and ribcage. The motion of the individual lumbar vertebrae was defined as a fraction of the net lumbar movement about the three rotational degrees of freedom: flexion–extension lateral bending, and axial rotation. Additionally, the eight main muscle groups of the lumbar spine were incorporated using 238 muscle fascicles with prescriptions for the parameters in the Hill-type muscle models obtained with the help of an extensive literature survey. The features of the model include the abilities to predict joint reactions, muscle forces, and muscle activation patterns. To illustrate the capabilities of the model and validate its physiological similarity, the model’s predictions for the moment arms of the muscles are shown for a range of flexion–extension motions of the lower back. The model uses the OpenSim platform and is freely available on https://www.simtk.org/home/lumbarspine to other spinal researchers interested in analyzing the kinematics of the spine. The model can also be integrated with existing OpenSim models to build more comprehensive models of the human body.