Propagation Characteristics of Ao Mode in a Metallic Beam Containing a Semi-infinite Crack

When Ao Lamb wave propagating in a sub-beam encounters the edge of a semi-infinite horizontal crack in a metallic beam, reflection, and transmission into the main beam and sub-beam takes place. Lamb mode transmitted from one sub-beam to the other is termed as "Turning Lamb Mode" (TLM). The variations in reflection and transmission factors of Ao Lamb modes, defined based on Fourier Transform and Wavelet Transform, when a horizontal crack is situated at different positions across the thickness of a beam were studies through numerical simulations. In addition to this, the power reflection and transmission ratios were also estimated. It was observed that the transmission and reflection characteristics of Ao Lamb mode strongly depend on the thickness ratio. It was also observed that the nature of variations in transmission factor, and power transmission coefficient of TLM with thickness ratio is different

Comparative Study of Damping in Pristine, Steel, and Shape Memory Alloy Hybrid Glass Fiber Reinforced Plastic Composite Beams of Equivalent Stiffness

Several efforts were made over the years to control vibration of structural components made of composite materials. This paper consists of study on effect of using shape memory alloy (SMA) to increase the damping of glass fiber reinforced plastic (GFRP) composites. A comparative study between SMA and steel was made as reinforcement material in GFRP composites to enhance damping. Dimensions of each beam were calculated such that all the beams i.e. pristine GFRP beam, GFRP beam embedded with steel wires and GFRP beam embedded with SMA wires have same flexural stiffness and first mode of frequency of vibration. Damping ratio was measured experimentally through logarithmic decay method. Through experiments damping ratio obtained for SMA hybrid composite beam was found to be higher as compared to the pristine and steel hybrid GFRP composite beams.

Suitability of Various Substrates for Cultivation of Pleurotus Pulmonarius in Konkan Region of Maharashtra

Mild tropical humid climate persists in Konkan region throughout the year within a range of 23 - 35 0 C. This climate is conducive for the commercial cultivation of oyster mushroom. Locally available substrates such as paddy straw, arecanut husk, coconut husk, banana pseudostem, groundnut shells, sugarcane bagasse and wheat straw alone and in combination with rice bran and wheat bran were used. Maximum biological efficiency of P. pulmonarius was recorded on paddy straw (76.30%) followed by wheat straw (74. 53 %). In case of supplemented substrates, the maximum biological efficiency of the mushroom was recorded on paddy straw supplemented with wheat bran (85.40%). This was followed by paddy straw supplemented with rice bran (82.63%) and wheat straw supplemented with wheat bran (82.26)

Suitability of Various Substrates for Cultivation of Pleurotus Pulmonarius in Konkan Region of Maharashtra

Mild tropical humid climate persists in Konkan region throughout the year within a range of 23 - 35 0 C. This climate is conducive for the commercial cultivation of oyster mushroom. Locally available substrates such as paddy straw, arecanut husk, coconut husk, banana pseudostem, groundnut shells, sugarcane bagasse and wheat straw alone and in combination with rice bran and wheat bran were used. Maximum biological efficiency of P. pulmonarius was recorded on paddy straw (76.30%) followed by wheat straw (74. 53 %). In case of supplemented substrates, the maximum biological efficiency of the mushroom was recorded on paddy straw supplemented with wheat bran (85.40%). This was followed by paddy straw supplemented with rice bran (82.63%) and wheat straw supplemented with wheat bran (82.26)

A user interactive design procedure for an efficient tubular linear induction motor for pneumatic capsule pipeline systems

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file viewed on (February 26, 2007)Includes bibliographical references.Thesis (M.S.) University of Missouri-Columbia 2006.Dissertations, Academic -- University of Missouri--Columbia -- Electrical engineering.[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Pneumatic Capsule Pipeline (PCP) systems are being increasingly used for freight transportation in selected industries like mining, tunneling and also in hospitals, drive-in banks, postal centers and airports. The widespread use of large PCP systems is achieved with the use of Tubular Linear Induction Motors (TLIM). TLIMs provide a non-intrusive system for the propulsion of the capsules inside the pipes.The need for an efficient and user-interactive design procedure for a TLIM pump to be used in PCP systems has fueled this research project. A user-interactive procedure was developed to design a highly detailed and efficient TLIM which generates the required electromagnetic thrust to propel capsules at the specified rated speed over long distances. Systems based on this design were recorded to be operating at about 75% efficiency which indicated a 7.5% increase in the efficiency as compared to previous designs. Future applications of such systems could involve high- speed, quiet and environmentally friendly freight and passenger transportation systems

Dielectric properties of quasi-one dimensional PbHPO4 crystal in presence of external electric field

The third and fourth order phonon anharmonic interactions external electric field terms are added in the two-sublattice pseudospin model for PbHPO4 crystal. By using double time thermal Green's function method modified model, theoretical expressions for soft mode frequency, dielectric constant, shift, width and tangent loss are evaluated for PbHPO4 crystal. Temperature and field variations of soft mode frequency, dielectric constant and loss tangent are calculated numerically. Present theoretical results agree with experimental result of Smutney and Fousek for dielectric constant of PbHPO4

Improvisation of Interfacial Bond Strength in Shape Memory Alloy Hybrid Polymer Matrix Composites

AbstractIn the present study, we report on a novel approach adopted for the improvisation of interfacial bond strength between shape memory alloy (SMA) and epoxy matrix in SMA hybrid composites. Methodologies such as surface roughening and chemical etching of SMA wires were performed before embedding them in epoxy matrix. A pull-out test has been performed to find out the improvement in load transfer between SMA and host matrix. Surface morphology of SMA wires after various surface treatments was observed under scanning electron microscope (SEM). Significant improvement, nearly 260%, in interfacial shear strength between SMA-Epoxy interfaces has been observed in case of specimens embedded with chemically etched SMA wire in comparison to the specimens with untreated SMA wire