RAS and STM investigations of pentacene molecules on metal and semiconductor surfaces

In this study the electronic surface states and surface reconstructions of an organic molecule on semiconductor and metal surfaces were investigated with Reflectance Anisotropy Spectroscopy (RAS), Scanning Tunnelling Microscopy (STM) and photoemission techniques. The design, construction and operation of a Reflectance Anisotropy Spectrometer are described in detail. The RAS technique was applied to the investigation o f pentacene on the Au(110)-(2xl) surface. It was found that the pentacene molecules adsorbed on this surface shows three observable electronic transitions in the 1.6 eV-5 eV photon energy range. At monolayer coverage there are distinct changes in the RAS spectrum that can be associated with a change in the orientation of the molecule on the gold surface. STM was applied to the investigation o f pentacene adsorbed on the Au(llO)- (2x1) and the A g /S i(lll)-(7 x 7 ) surface. It was found that on the Au(l 10)-(2xl) surface, below a monolayer the pentacene molecule adsorbs parallel to and between the Au rows in the [11 0] direction, While above a monolayer the molecule changes direction and preferentially adsorbs across the gold rows. This change in orientation accounts for the changes in the RAS spectra above a monolayer. The effect o f annealing on the molecular ordering was also studied. These interfaces were also studied by core level and valence band photoemission using a synchrotron light source. Deposition o f pentacene on the Ag/Si(l 11)-(V3 xy/3 ) surface produced three distinct ordered structures for coverages up to one monolayer. It is concluded from the RAS, STM, synchrotron studies that the molecule lies flat on the Au(110) and Ag/Si(l 11) surfaces

Paths to Post-Nationalism: A Critical Ethnography of Language and Identity by Monica Heller

No abstract available

For Better, or For Worse: Photographing in a Digitally Cluttered Crowd

In recent years, smartphones have been utilized to photograph treasured moments. However, some are unaware they are distracting others in events such as weddings. The distracting smartphone user could potentially obstruct professional wedding photographers and hinder them from capturing priceless shots. The purpose of this thesis is to research the motive behind the addictive nature of smartphones and potentially decrease the number of smartphone pictures taken during the wedding ceremonies. The goal of this study is to bring awareness to the problem and to create a mobile application, which could then reduce the intrusiveness of smartphones during weddings. The researcher will observe wedding ceremonies in the United States, interview several wedding planners and other photographers to see if they have any suggestions for correcting “guest photographers,” and survey the general public to note their experience with cellphones at weddings

Improved circuit for measuring capacitive and inductive reactances

Amplifier circuit measures very small changes of capacitive or inductive reactance, such as produced by a variable capacitance or a variable inductance displacement transducer. The circuit employs reactance-sensing oscillators in which field effect transistors serve as the active elements

Seismographic recording of large rocket engine operation

Recording equipment for rocket engine vibration is adaptable to determining the structural strength of building materials. This seismographic system is portable and is capable of measuring displacements in the direction of three mutually perpendicular axes