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Full-Text Articles in Engineering

Analysis Of Vibrational Modes Of Chemically Modified Tone Wood, Madison Flesch Jan 2018

Analysis Of Vibrational Modes Of Chemically Modified Tone Wood, Madison Flesch

Honors Program Theses

It is generally accepted that every violin has different tone quality in terms of intonation and the depth of the harmonics produced. The best violins are made by experienced luthiers that craft each with precision to produce the best possible tonal quality. The quality of the finished violin is dependent upon both the specific shape and the vibrational response of the wood used in its construction. Because the hard wood used in violin construction is inhomogeneous, the composition and structure of material used is critical to the final product.1 Luthiers would initially rely on their experience to feel the …


Growth And Characterization Of Nanoscale Thin Films, Erik Thomas Wolter Jan 2011

Growth And Characterization Of Nanoscale Thin Films, Erik Thomas Wolter

Honors Program Theses

Thin manganese films were grown by thermal evaporation in high vacuum. The growth rate was varied to determine how the growth rate affects the continuity of ultra-thin films. The resistance was measured with the two-point method in situ and the data was recorded digitally. The resistance was converted to resistivity and this was plotted against thickness. It was found that resistivity decreases exponentially as the film begins to form in islands. The film reaches a critical thickness as the islands coalesce and the data can then be fitted with Fuchs’ equation. The resistivity continues to decrease but the minimum resistivity …


Synthesis And Characterization Of A [Ru(Bpy)2(Ncs)2] Derivative For Use As A Dye-Sensitizer In Nanocrystalline Solar Cells, Joel Thomas Kirner Jan 2010

Synthesis And Characterization Of A [Ru(Bpy)2(Ncs)2] Derivative For Use As A Dye-Sensitizer In Nanocrystalline Solar Cells, Joel Thomas Kirner

Honors Program Theses

After extensive review of the field of dye-sensitized solar cells, the molecule [Ru(4,4’- dicarboxy-2,2’-bipyridine)(4,4’-di-(2-(2-pyridyl)ethenyl)-2,2’-bipyridine)(NCS)2] has been designed as an original contribution to the field. This dye sensitizer was chosen by derivatizing upon the structure of the standard sensitizer, cis-diisothiocyanatobis(4,4’-dicarboxylic acid-2,2’- bipyridine)ruthenium(II) (N3), by extending the conjugation of one bipyridine ligand. This structural derivatization should enhance light harvesting by red-shifting the dye’s absorbance and increasing the dye’s molar absorptivity, which should result in a dye-sensitized solar cell with higher efficiency. The Density Functional Theory (DFT) molecular orbital calculations of the new dye complex indicate that the HOMO is highly localized …


The Corrosive Effects Of Salt Spray On Electrolytic Zinc Plated Mechanical Fasteners: The Case Of Clear Chromate And Yellow Dichromate Coatings On Medium Carbon Plated Bolts, Souleymane Boukari Jan 1994

The Corrosive Effects Of Salt Spray On Electrolytic Zinc Plated Mechanical Fasteners: The Case Of Clear Chromate And Yellow Dichromate Coatings On Medium Carbon Plated Bolts, Souleymane Boukari

Dissertations and Theses @ UNI

The purpose of this study was to evaluate the relationship between plating thickness and corrosion resistance of zinc coated medium carbon steel bolts under salt spray moisture conditions. Two types of zinc coatings were chosen for the study: the clear chromate zinc and the yellow dichromate zinc. One hundred and eighty 3/8-16 x 5 3/4 inch medium carbon steel bolts were selected for the test and divided into groups of 18. Two types of salt solution were used in the study: the low salt and the high salt. Bolts with various coatings tested with low salt concentration were composed of …