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Physical interaction between two bulk media occurs mainly at the surface interface. The surface properties of materials therefore dictate how a system will respond to different influences, while being just a fraction of the entire volume. Alteration of a surface can therefore have a significant effect on a system. In this thesis the functionalization of surfaces via covalent attachment of short chained molecules was undertaken to manipulate surface-surface interactions for different outcomes. The separation and purification of bulk media of impurities has always been undertaken. Many different processes exist, however the removal of impurities from dynamic or open systems remains a problem. The use of filtration technologies remains the best option in this type of system. In filtration technology membranes are employed to selectively remove one or more elements from another generally under a driving force. The selectivity of a membrane has either traditionally relied on either physical attributes such as pore size or chemical attributes such as charge, van der Waals etc. In this thesis we propose the use of organically functionalized ceramic nanoparticles alumoxanes to act as a coating of the side walls of the fibers of a base bulk fabric material Nomex © . The side chain of cysteic acid has been found to be extremely hydrophilic due in part to its Zwitter ionic properties. The use of hydrophilic cysteic acid alumoxane was used as part of a composite membrane to screening hydrocarbons. Doping of this membrane with cysteic acid ferroxane the iron analogue of alumoxane was used as a membrane to screen MS2 bacteriophage.

This thesis describes several calibrations of the Time-of-Flight (TOF) detector at the Solenoidal Tracker at RHIC (STAR). These calibrations are required to allow Particle Identification (PID) which benefits many physics analysis. These calibrations treat the Integral Non-Linearity (INL) of the time to digital converters, the global offsets, the slewing from pulse time dependence on the pulse height, and the transmission times inside the detectors. Each of these corrections will be described. The data for the INL correction was collected at Rice University using two different electronics configurations. Care was taken to insure the two approaches were consistent. These calibrations were tested using "cable-delay tests." Data from RHIC Run 9 200 GeV data will be used to confirm the effectiveness of the INL, offset, slewing, and transmission time calibrations.

Influenza A and B viruses are significant human pathogens responsible for the annual seasonal "flu". Diverged some 2000 years ago, influenza B virus has several important differences from influenza A virus, including lower receptor-binding affinity and very limited host range. Based on sequence comparison and our prior structural studies, we hypothesized that a key difference in the receptor-binding site of influenza virus hemagglutinin (HA), phenylalaline (Phe) 95 in influenza B virus HA (BHA), versus tyrosine (Tyr) in influenza A virus HA (AHA), is possibly the molecular basis for the different receptor-binding affinity. We further hypothesized that this could be at least partially responsible for the very limited host range of influenza B virus. By using glycan and red blood cell binding assays, we demonstrated that the mutation Phe95[arrow right]Tyr in BHA substantially enhanced receptor-binding affinity. Furthermore, this mutation efficiently competed against the infection of influenza A virus and greatly improved the binding of BHA to three mammalian cell lines. Taken together, residue 95 of BHA appears to be a key determinant for the receptor binding affinity and host range of influenza B virus.

The magnetic field is the dominant force in the Sun's outer atmosphere, the corona. It determines the large-scale structure of the corona, governs the small-scale activity that heats the plasma, and powers energetic transient phenomena. The study of the coronal magnetic field is an important component of efforts to understand the corona as a whole, but the high plasma temperature and relative weakness of the field in the corona preclude direct measurement of the field in this region. Theoretical modeling, therefore, provides critical support to our investigation of the coronal magnetic field. This thesis contains an exploration of magnetic modeling in the context of the physics of the solar atmosphere. Using the novel stereoscopic capability of the Solar Terrestrial Relations Observatory, we compare the 3D coronal field structure with various models to study the distribution of the magnetic field and large-scale currents in several active regions. In addition to using existing models, we developed an original modeling approach: using several magnetic dipoles under the solar surface, configured based on comparison with the observed field structure, we overcome certain weaknesses inherent in existing models. The misalignment angles between the vectors of the reconstructed and model fields measure the departure of the model field from the observed field structure, indicating the non-potentiality of the coronal field. The dipole modeling method achieves a significant reduction in misalignment compared with previously established models, implying a closer agreement between our model field and observed field structures. We use the misalignment measurements to examine the free energy contained in active region magnetic fields and find that following major flares, the field relaxes substantially from a high-shear configuration to a low-shear configuration, indicating a significant loss of free energy in the field. The results in this thesis yield insight into the physics of the solar atmosphere and provide a means to better understand the complex region between the photosphere and corona. Improved understanding of this region will elucidate how the field connects the two regions, and the way in which energy is transported from the convective solar interior into the corona and heliosphere.

Magnetic pair creation, γ [arrow right] e + e - , is a key component in polar cap models of gamma-ray pulsars, and has informed assumptions about the still poorly understood radio emission. The Fermi Gamma-Ray Space Telescope has now detected more than 100 γ-ray pulsars, providing rich information for the interpretation of young energetic pulsars and old millisecond pulsars. Fermi observations have established that the high-energy spectra of most of these pulsars have exponential turnovers in the 1-10 GeV range. These turnovers are too gradual to arise from magnetic pair creation in the strong magnetic fields of pulsar inner magnetospheres, so their energy can be used to provide a physically motivated lower bound to the typical altitude of GeV band emission. This work computes pair creation opacities for photon propagation in neutron star magnetospheres. It explores the constraints that can be placed on the emission location of Fermi γ-rays due to single-photon pair creation transparency below the turnover energy, as well as the limitations of this technique. These altitude bounds are typically in the range of 2-6 neutron star radii for the Fermi pulsar sample, and provide one of the few possible constraints on the emission altitude in radio quiet pulsars that do not possess double-peaked pulse profiles.

The lipid matrix of cell membranes is a natural binding site for amphipathic molecules. Consequently there are water-soluble, amphipathic peptides and proteins that exert their functions on membranes. Studies also showed that binding of amphipathic molecules (such as drugs) may change the functions of membrane proteins by altering the physical properties of the membrane. Thus, we want to understand how amphipathic molecules interact with membranes and find out the consequences of such membrane-molecule interactions. My thesis consists of development of new methods for studying the kinetics of molecular interactions with membranes and a series of comparative studies on different membrane-active molecules including peptides, proteins and drugs. My contribution to the methods for kinetics is to complement the equilibrium methods already developed in our lab for past twenty years. I established a micropipette aspiration system based on the system developed by Evan Evans in the 80's, but instead of measuring the elastic properties of membranes, we used it to study the dynamic interaction processes between amphipathic molecules and membranes.