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

Parameters' Effect on Weld Quality for Dissimilar Spot Welding Between Ferritic Stainless Steel and Low Carbon Steel Sheets

Abstract: This work discusses the effect of main controlling parameters of spot welding process on the quality of dissimilar welded joint between ferritic stainless steel grade 430, FSS with 0.5 mm thickness and low carbon steel, LCS with 0.6 mm thickness sheets. Parameters studied were welding current, welding time and electrode pressure. Metallurgical and mechanical characteristics were determined through microstructure, tensile shear and microhardness examinations. The results of this study showed that the suitable electrode pressure in this dissimilar combination of steels; FSS and LCS; was 0.2MPa (2 bar). It was found also that the welding current is the most influential parameter on weld quality. The best weld strength was obtained at 3.4 KA. Increasing welding current and welding time up to certain level increases the joint strength, after this level the joint strength decreases. Investigations showed also that the dominant structure of the nugget is martensite. The fracture due to tensile shear test was mainly intergranular in ferritic stainless steel side and the fracture mode was button pullout

Efficacy of adhesive taping in controlling genu recurvatum in diplegic children: A pilot study

AbstractAdhesive taping has been commonly used to improve the performance through supporting joint structure and reducing pain. Restoring knee alignment in diplegic children is critical in an effective treatment program. The purpose of this article is to investigate whether adhesive taping is effective in controlling genu recurvatum in diplegic cerebral palsy children. Fourteen children with diplegic cerebral palsy (8 boys and 6 girls with a mean age of 6.22years), participated in a 12-week program. Children were assigned randomly to one of two groups: therapeutic taping+physical therapy or knee cage+physical therapy. Therapeutic taping was applied for periods of up to 60h over knee. The effects were assessed with the Gross Motor Function Measure (GMFM-88), Auto CAD, Screen protractor at baseline and 12weeks after treatment. The primary outcome measure was knee angulations, using Auto CAD and screen protractor software. The Gross Motor Function Measure-88 (GMFM-88) standing and walking subsections were the secondary outcome measures. No significant differences were found between groups over time. Adhesive taping does not evoke a positive change in controlling genu recurvatum in children with diplegic cerebral palsy

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

Similitude and scaling of large structural elements: Case study

AbstractScaled down models are widely used for experimental investigations of large structures due to the limitation in the capacities of testing facilities along with the expenses of the experimentation. The modeling accuracy depends upon the model material properties, fabrication accuracy and loading techniques. In the present work the Buckingham π theorem is used to develop the relations (i.e. geometry, loading and properties) between the model and a large structural element as that is present in the huge existing petroleum oil drilling rigs. The model is to be designed, loaded and treated according to a set of similitude requirements that relate the model to the large structural element. Three independent scale factors which represent three fundamental dimensions, namely mass, length and time need to be selected for designing the scaled down model. Numerical prediction of the stress distribution within the model and its elastic deformation under steady loading is to be made. The results are compared with those obtained from the full scale structure numerical computations. The effect of scaled down model size and material on the accuracy of the modeling technique is thoroughly examined

Growth Hormone potentiates 17beta-estradiol-dependent breast cancer cell proliferation in an IGF-I-independent manner

Estrogen action in mammary gland development and breast cancer progression is tightly linked to the growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis. In rodents, both estradiol (E2) and GH are necessary for gland development and carcinogenesis. However, to what extent the effects of GH are mediated by IGF-I is unclear. Here, we demonstrate in Spontaneous Dwarf rats, which lack endogenous GH, that both GH and estradiol (E2) are critical to maintain proliferation of normal and cancerous mammary epithelial cells. In T47D human breast cancer cells, GH significantly enhances E2-stimulated proliferation. While the in vivo effects of GH may be direct on mammary epithelial cells and/or mediated by increased IGF-I, GH action in T47D cells was independent of IGF-I expression and IGF-IR signaling, suggesting that GH also may exert direct effects on breast cancer cells. Use of an IGF-IR inhibitor demonstrated that while E2-dependent proliferation required IGF-IR signaling, the combination of GH+E2 overcame IGF-IR blockade, restoring proliferation. In contrast, studies with specific inhibitors indicate that GH action through both Jak2 and EGFR was required for subsequent ERK activation and was essential for potentiation of E2-dependent proliferation. Downstream of these pathways, we identified a number of immediate early response genes associated with proliferation that are rapidly and robustly up-regulated by GH. Taken together, these findings demonstrate that GH can have important effects in breast cancer cells that are distinct from IGF-I, suggesting that novel drugs or improved combination therapies targeting ER and the GH/IGF axis may be beneficial for breast cancer patients