Soft lithography replica molding of critically coupled polymer microring resonators

We use soft lithography replica molding to fabricate unclad polystyrene (PS) and clad SU-8 microring resonator filters. The PS resonator has an intrinsic quality factor of 1.0/spl times/10/sup 4/ at /spl lambda/=1.55 /spl mu/m, while that of the SU-8 resonator is 7100. The extinction ratios of the PS and SU-8 microring filters are -12 and -20 dB, respectively, with net insertion losses of 6.7 and 9.9 dB. The good quality factors and high extinction ratios of the microring resonator filters show the practicality of soft-lithography replica molding for the fabrication of integrated optical devices

Perceptions of product blogs in Taiwan

Department Head: Greg Luft.2010 Summer.Includes bibliographical references (pages 76-82).A survey was conducted among college students in Taiwan (n=314) regarding their use, perceptions and responses to blogs that discuss products and services. Predictor variables included prior use/experience with blogs, the motivations of blog readers (seeking knowledge/information versus social utility/entertainment), the effects of blogger affiliation (independent, employee of manufacturer, paid), and the effects of balanced versus all-positive language. Criterion variables included assessments of credibility and value, purchase intent, and the likelihood of engaging in word-of-mouth (information sharing) online and offline. Blog readers in the study were primarily motivated by knowledge/information seeking rather than social utility/entertainment. As hypothesized, assessments of credibility and value were positively related to bloggers being independent and using balanced (versus all-positive) language. However, no statistically significant main effects were discerned based on these variables for purchase intent or for the likelihood of sharing information with others. Notably, respondents were more likely to respond offline than online, and females were more likely than males to engage in information sharing. People with positive attitudes toward blogs also were more likely to assess blogs as more trustworthy compared to either advertisements or news. Hierarchical regression suggested that attitudes toward blogs and purchase intent were best predicted by a knowledge/information motivation, although independence of the bloggers closely approached statistical significance. Information sharing online was best predicted by motivation based on social utility/entertainment (versus product knowledge), hours of e-mail use, and blogger affiliation. Information sharing online was also positively related to both forms of motivation and to the use of balanced language. Implications for blog marketing, limitations and directions for future research were discussed

Transmission characteristics of a Fabry-Perot etalon-microtoroid resonator coupled system

The transmission spectra of a Fabry-Perot etalon coupled to a microtoroid resonator are studied theoretically and experimentally. The resonance line shapes depend strongly on the resonance wavelength detuning and coupling strength between the two resonators. A wide variety of line shapes, ranging from a single to triple peaks, symmetric to asymmetric Fano-like peaks, and notches were predicted and observed experimentally. The capability to modify the spectral line shapes by tuning the coupling between or losses of two resonators may find applications in optical filtering, switching, sensing, and dispersion engineering

Combined electromagnetic and photoreaction modeling of CLD-1 photobleaching in polymer microring resonators

By combining a solid-state photoreaction model with the modal solutions of an optical waveguide, we simulate the refractive index change due to the photobleaching of CLD-1 chromophores in an amorphous polycarbonate microring resonator. The simulation agrees well with experimental results. The photobleaching quantum efficiency of the CLD-1 chromophores is determined to be 0.65%. The combined modeling of the electromagnetic wave propagation and photoreaction precisely illustrates the spatial and temporal evolution of the optical properties of the polymer material as manifested in the refractive index and their effects on the modal and physical properties of the optical devices

Federal, Ohio, and Cuyahoga County Timeline of Programs in Response to Housing Foreclosures: 2005-2015

This timeline contains information on federal, Ohio and Cuyahoga county programs in response to housing foreclosures by month from 2005-2015. Zoom in to view timeline details (including links to relevant reports and other documentation)

Federal, Ohio, and Cuyahoga County Timeline of Programs in Response to Housing Foreclosures: 2005-2015

This timeline contains information on federal, Ohio and Cuyahoga county programs in response to housing foreclosures by month from 2005-2015. Zoom in to view timeline details (including links to relevant reports and other documentation)

Optimizing Centrate Bioaugmentation Reactors by Monitoring Ph and Do to Produce Maximum Nitrification While Minimizing Aeration Energy

Efficient removal of nitrogen from wastewater is a necessity for many treatment facilities due to the use of fertilizers, the growing human population and increasingly stringent nutrient standards for wastewater effluent. Nitrogen entering the wastewater stream is typically in the form of ammonia and organic nitrogen. Biological nitrogen removal (BNR) is the most commonly used method for removing excess ammonia from wastewater. Metro Wastewater Treatment Facility provides wastewater transmission and treatment services to a large portion of metropolitan Denver and surrounding cities. Due to concern over high ammonia loads from centrate causing stress on the main system, a sidestream bioreactor known as CaRRB is currently in place. Despite the consistency of the operational parameters of CaRRB, large fluctuations in the nitrification performance are occurring and affecting the main system, causing unsteady effluent ammonia concentrations. The goal of this project was to identify the causes of the fluctuations by evaluating the basic factors that impact nitrification and assess potential resolution

Geothermal Heating and its Influence on the Meridional Overturning Circulation

The effect of geothermal heating on the meridional overturning circulation is examined using an idealized, coarse-resolution ocean general circulation model. This heating is parameterized as a spatially uniform heat flux of 50 mW m-2 through the (flat) ocean floor, in contrast with previous studies that have considered an isolated hotspot or a series of plumes along the mid-Atlantic ridge. The equilibrated response is largely advective: a deep perturbation of the meridional overturning cell on the order of several Sv is produced, connecting with an upper-level circulation at high latitudes, allowing the additional heat to be released to the atmosphere. Risingmotion in the perturbation deep cell is concentrated near the equator. The upward penetration of this cell is limited by the thermocline, analogous to the role of the stratosphere in limiting the upward penetration of convective plumes in the atmosphere. The magnitude of the advective response is inversely proportional to the deep stratification; with a weaker background meridional overturning circulation and a less stratified abyss, the overturning maximum of the perturbation deep cell is increased. This advective response also cools the low-latitude thermocline. The qualitative behavior is similar in both a single hemisphere and double hemisphere configuration.The anomalous circulation driven by geothermal fluxes is more substantial than previously thought. We are able to understand the structure and strength of the response in the idealized geometry and further extend these ideas to explain the results of Adcroft et al. [2001], where the impact of geothermal heating was examined using a global configuration