Investigation of Quality Control and Analysis for Small Breweries

Small breweries have become a growing trend in the Pacific Northwest, as well as nationwide. Many microbreweries lack the advantages large breweries have (time, space, and money) when it comes to testing their beer in regards to quality analysis and control. The objectives of this study were to modify and develop QA/QC protocols from the American Society of Brewing Chemists Methods for Craft Breweries (ASBC) for use in classrooms or small breweries. This work focused on revising methods for international bitterness units (IBU), alcohol by volume (ABV), and standard reference method (SRM) for beer. Samples were donated from local breweries and analyzed using the standard operating procedures (SOP) developed in the study. Instrumentation included UV-Vis spectroscopy and gas chromatography with a flame ionization detector

Synthesis and Characterization of Au:Ag Core-Shell Nanoparticles with 4-Aminothiophenol Surface Enhance Raman Spectroscopy (SERS) Tag

At the Linfield Symposium the research on silver coated gold nanoparticles tagged SERS will be presented. Gold core nanoparticles were synthesized and coated with a silver shell. These core-shell nanoparticles were tagged with a Surface Enhanced Raman Signal (SERS) tag, 4-aminothiophenol. These tagged particles were monitored for stability and signal enhancement over time. When stability was proven, the tagged particles were coated with a polymer (PAH) and then a lipid bilayer (POPS:LPC). These particles were again monitored for stability and signal strength on the Raman. The overall goal was to synthesize silver coated gold nanoparticles, tag and enhance their Raman signal, and coat them with lipids while keeping the particles at a reasonable small size

Investigation of the Link between Media Acidity and pI in Obtaining Optimum Surface-Enhanced Raman Scattering for Proteins

Surface-enhanced Raman spectroscopy (SERS) is an important tool in the characterization of proteins, which can lead to vital information pertaining to biological functions. Spectra of lysozyme, bovine serum albumin (BSA), catalase, and hemoglobin were obtained using SERS on silver colloids with sodium sulfate as the aggregating agent. Optimization of the SERS was attempted through adjustment of the acidity of sulfate aggregating agent. A link was investigated between the pI (pH at which there is no net charge on the molecule) of the proteins and the pH of the solutions needed for optimum SERS. It was found that any pH higher than the pI of the protein would not result in readable Raman bands. SERS of each protein were obtainable at any pH below the protein’s pI and was enhanced until reaching a pH of approximately two. At any pH lower than two, SERS were not possible because of inability of the aggregating agent to work in extreme pH conditions

Synthesis and Characterization of Coated Gold Nanoparticles with Embedded SERS Tags

Gold nanoparticles were prepared with the potential to operate as drug delivery vehicles. Surface-enhanced Raman spectroscopy (SERS) is of particular importance as an optical bioimaging technique due to its ability to allow deep and high-resolution volumetric imaging of biological tissues. Characterization of the gold nanoparticles with para-mercaptobenzoic acid (pMBA), a SERS active molecule, silver, and a phospholipid bilayer was done using Raman and UV-vis spectroscopy and particle size analysis. Our results indicate successful coating of the gold nanoparticles and show consistent pMBA Raman spectroscopy peaks that will allow for the nanoparticle use in-vivo to be monitored

Determination of the Optimal Conditions for Bovine Serum Albumin Surface Enhanced Raman Scattering on Silver Colloids

Bovine serum albumin (BSA) was analyzed using surface enhanced Raman scattering (SERS) to find the optimal conditions to observe BSA with SERS. Colloidal silver, Na2SO4, and BSA were mixed together at varying pHs and concentrations to obtain multiple spectra.The most favorable conditions using SERS for BSA were 500ug/mL and pH 4.The spectrum under those conditions showed the most intense and discernible peaks and the alpha helical secondary structure was very distinct at 1297 cm-1. SERS can be used for label free detection of proteins, thus finding the best conditions to obtain spectra using this technique may be very beneficial to proteomic research

Alloyed Nanoparticles with Lipid Coatings

Monodisperse silver and gold alloy nanoparticles of controlled composition and size were synthesized for the development of a potential drug delivery system. The seeded growth of the alloy nanoparticles through a co-reduction of gold and silver salts, using the Turkevich approach, was used for synthesizing the nanoparticles. The size of the nanoparticles was characterized using a NanoSight LM10 HS and their composition with a UV-Vis spectrophotometer. These alloys and earlier gold nanoparticles of varying sizes were introduced to live wild-type S. cerevisiae cells in their exponential growth phase, and the absorbance of the cells after incubation with nanoparticles was measured with a UV-Vis spectrophotometer. Absorbance data suggests that the number of nanoparticles taken up by the yeast cells is negligible as no peak was observed in the yeast cells after they had been washed and centrifuged to discard excess alloy nanoparticles. Further research is necessary to see if the addition of antibodies increases the number of nanoparticles attached to the yeast cells, future coating with lipids and a SERS tag, and maybe even attaching a therapeutic agent

Synthesis and Characterization of Lipid Coated Nanoparticles as Drug Delivery Vehicles

Spherical monodisperse nanoparticles composed of gold or silver cores were modified with lipids as part of an ongoing project to utilize functionalized nanoparticles as drug delivery vehicles. A reduction reaction with sodium tri-citrate was used to synthesize nanoparticles that were characterized physically through a NanoSight LM10 HS particle sizer as well as optically with a Shimadzu UV-vis spectrophotometer. The particles were then characterized again after purification of excess ligands through centrifugation. Poly(allylamine hydrochloride) was added to flip the surface charge of the particles from negative to positive as well as to serve as a stabilizing agent. After purification, the particles were coated with lipids and spun to purify them. Characterization data suggest that the particles are successfully coated with both poly(allylamine hydrochloride) and lipids and that monodispersity was maintained, as evidenced by the measured changes in size and optical properties

Kinetics of the Photoreduction of \u3cem\u3ep\u3c/em\u3e-nitrobenzoic Acid on Ag and AgxAu1-x Nanoparticle Films

A recent strategy to increase the efficiency of photovoltaic and photoemissive devices has been to include metal nanolayers in contact with an organic layer inside these devices. Metal nanoparticles (especially Ag and Au) are known to catalyze photoreactions of organic molecules on their surfaces. The reactivity of organics at nanometal surfaces has implications for device lifetimes; therefore, it is important to understand how nanoparticle size and composition influence reaction rates. The photoreduction of p-nitrobenzoate (PNBA) to p,p’-azodibenzoate (PPADBA) on Ag nanoparticles is an excellent model system for studying such reactions. We have measured the reaction rate of PNBA to PPADBA on Ag and Au based nanoparticle surfaces using surface-enhanced Raman spectroscopy (SERS). SERS is a highly sensitive spectroscopic tool, which provides molecular fingerprints that can be used to identify molecular species present on metal nanoparticle surfaces. These surfaces are made from layers from Ag and AgxAu1-x alloy nanoparticles with diameters ranging from 50-80 nm

Innovations in energy and climate policy: lessons from Vermont

We ask in this article: how can planners and policymakers replicate Vermont’s energy and climate policies? We begin by explaining the research methods utilized for this article—mainly research interviews with a pool of experts, coupled with a targeted literature review. We then analyze the success of Vermont energy policy across four areas: energy efficiency, renewable energy, the smart grid, and energy governance. The following sections first explain how Vermont accomplished these successes, next identify a number of remaining barriers and elements of Vermont’s approach that may not be replicable, and finally present the article’s conclusions

Examination of Silica Sol-Gels and Aerogels Containing Silver Nanoparticles and 4-Mercaptobenzoic Acid Using Surface-Enhanced Raman Spectroscopy

Sol-gels and aero-gels containing silver nanoparticles have been investigated for use as substrates in surface-enhanced Raman spectroscopy (SERS). 4-Mercaptobenzoic acid (4-MBA) was chosen as the target molecule in this study, as it has been well-characterized using SERS. The orientation of the 4-MBA at different coverages in gels, and at differing concentrations of silver colloid, has not been well studied. For both base and acid-catalyzed sol-gels, xerogels, and aerogels, the concentration of 4-MBA was varied with a constant silver colloid concentration in the silica gels and the effects were measured with SERS. The effect of varying silver colloid concentration against a constant 4-MBA concentration was also investigated. The results of each process were compared