7 research outputs found
Shear Behavior of Steel I-Beams Strengthened With CFRP Strips
This paper studies the behavior of simply supported steel I-beams strengthened with carbon fiber reinforced polymers (CFRP) strips on the web as shear reinforcement. The experimental program contains seven simply supported steel beams. One of them was considered as a control beam and the other specimens were strengthened with different schemes; varying the position of CFRP strips to the web, its number of layers and its angle of orientation. The results show that applying CFRP strips on the web of the steel I-beams was an effective strengthening method for increasing the load bearing capacity and decreasing the deformations. Using two layers of diagonal CFRP strips on both sides of the web realized the highest increasing in the load capacity. Moreover, finite element analysis method has been utilized to analyze the tested specimens using ANSYS. A great convergence between the experimental results and the corresponding ones obtained from finite element simulation
Principles of Hand Fracture Management
The hand is essential in humans for physical manipulation of their surrounding environment. Allowing the ability to grasp, and differentiated from other animals by an opposing thumb, the main functions include both fine and gross motor skills as well as being a key tool for sensing and understanding the immediate surroundings of their owner
Hormonal regulation of spermatogenesis
Proper functioning of the mammalian testis is dependent upon an array of
hormonal messengers acting through endocrine, paracrine, and autocrine
pathways. Within the testis, the primary messengers are the
gonadotrophins, follicle stimulating hormone and luteinizing hormone, and
the androgens. Abundant evidence indicates that the role of the
gonadotrophins is to maintain proper functioning of testicular somatic
cells. It is the androgens, primarily testosterone, which act through the
somatic cells to regulate germ cell differentiation. Despite extensive
research in this area, little is known about the cell-specific
requirements for androgens and even less is understood about the
downstream effectors of androgen signalling. However, recent work using
cell-specific ablation of androgen receptor function has demonstrated a
clear requirement for androgen signalling at multiple, discrete time
points during spermatogenesis. These models also provide useful tools for
identifying the targets of androgen receptor activity. The purpose of this
review is to provide a brief overview of recent advances in our
understanding of hormonal regulation of spermatogenesis, with an emphasis
on the role of testosterone within the testis, and to pose important
questions for future research in this field