High Resolution Pure Rotational Raman spectra of Benzene in the Ground State

Department of ChemistryWe used mass-Correlated Rotational Alignment SpectroscopY (mass-CRASY) and obtained pure rotational Raman spectra for benzene in a broad spectral bandwidth of 500 GHz. The rotational spectra were calibrated against a GPS stabilized clock. With a combined optomechanical and electronical delay and randomly sparse sampling, we achieved single MHz resolution for frequency domain spectra of benzene in the ground state. A ground state rotational constant, ????0 = 5689.2671(52) MHz and centrifugal distortion constants ???????? = 1178 (50) Hz and ???????????? = -2300(120) Hz were obtained in 1 MHz resolution spectrum. 1 MHz resolution pure rotational Raman benzene spectrum partially resolved K-structures in two bands. The partially resolved K structure in 1 MHz resolution gave us ideas on the J, K quantum numbers and centrifugal distortion constants for benzene, degeneracy due to molecular symmetry. We reconsider the discrepancies between literature data and our works, and various discussed uncertainties and error sources in different spectroscopic methods.ope

Development of micropump for microfluidic applications

This dissertation covers the research work on two types of micropumps, one is based on magnetohydrodynamic (MHD) principle that utilizes Lorentz force for actuation, and the other is based on electrochemical actuation. The AC-type MHD micropump was designed and analyzed as a solution to the bubble formation problem encountered in DC-type MHD micropump. A UV-LIGA process using thick layer of SU-8 negative photoresist was successfully developed to microfabricate the AC MHD micropump. Preliminary studies and tests of the AC MHD micropumps demonstrate that bubble formation was significantly reduced to permit the proper function of the micropump. A continuous flow was also successfully demonstrated with no moving mechanical parts needed. To develop the mathematical model for flow of conductive fluids between the electrodes was a challenging issue. To overcome this problem, the impedance of conductive fluids between two electrodes was measured by Electrochemical Impedance Spectroscopy, which then helped to obtain a relatively accurate mathematical model for the system. The design, simulation, fabrication, and test results of the AC MHD micropump are presented in this dissertation. Electrochemical actuator was investigated for micropumping applications. In our research efforts to develop DC-type MHD micropump, bubble formation problem caused by electrolysis proved to be one of the most difficult issues. However, microactuation based on expanding bubbles from electrolysis effect has scale advantages compared with other commonly used microactuation mechanisms. It can therefore be used as a very efficient actuation source for micropumping applications. We have designed, analyzed, and fabricated a microactuator based on the electrochemical principle. Preliminary experiments have proved that the bubbles generated in electrolysis can be manipulated by carefully controlling the direction and amplitude of the input signal. This has demonstrated that efficient pumping at micro volume of fluid can be realized by addition of required valves. The microfluidic system with micropump and integrated active microvalve has been successfully demonstrated. The working principle, design, simulation, and preliminary results of the electrochemical actuator have also been presented in the dissertation

Quality Characteristics of Irradiated Turkey Breast Rolls Formulated with Plum Extract

The effects of adding 1%, 2% and 3% plum extract on the quality characteristics of vacuum-packaged, irradiated RTE turkey breast rolls were determined. Turkey breast rolls were sliced, packaged and irradiated at 0 or 3 kGy using a Linear Accelerator. Lipid oxidation, volatile profiles, color, texture, proximate analysis and sensory characteristics of sliced turkey breast rolls were determined at 0 and 7 days of storage. Addition of plum extract had no detectable effect on the proximate analysis of turkey breast rolls. Plum extract increased a* and b*- values, and decreased L* value of turkey breast rolls due to the original color of plum extract. Addition of \u3e2% plum extract to turkey breast rolls was effective in controlling lipid oxidation of irradiated meat and the production of aldehydes (hexanal, heptanal, octanal, and nonanal) in nonirradiated meat at Day 0. Texture of turkey breast rolls was not influenced, but juiciness was increased by plum extract. Therefore, addition of 3% or higher of plum extract is recommended to improve mouth-feel and antioxidant effect in irradiated turkey breast rolls. However, the color of turkey breast rolls with 3% plum extract was dark and might not be appealing to consumers

Fabrication and tuning of plasmonic optical nanoantennas around droplet epitaxy quantum dots by cathodoluminescence

We use cathodoluminescence to locate droplet epitaxy quantum dots with a precision $\lesssim$ nm before fabricating nanoantennas in their vicinity by electron-beam lithography. Cathodoluminescence is further used to evidence the effect of the antennas as a function of their length on the light emitted by the dot. Experimental results are in good agreement with numerical simulations of the structures

Consumption of Oxidized Oil Increases Oxidative Stress in Broilers and Affects the Quality of Breast Meat

A total of 120 4-week-old broiler chickens were allotted to 12 pens and fed one of three diets including control, oxidized diet (5% oxidized oil), or antioxidant-added diet (500 IU vitamin E) for 2 weeks. Blood samples were collected at the end of feeding trial, and breast muscles were sampled immediately after slaughter. Breast meats were also collected 24 h after slaughter and used for meat quality measurements. Oxidative stress in blood, lipid and protein oxidation, and sarcoplasmic reticulum Ca2+-ATPase (SERCA) activity of breast muscle were determined. The oxidized diet increased oxidative stress in blood and increased carbonyl content in breast meat compared with the other two dietary treatments (P \u3c 0.05). Lipid oxidation of breast muscles with the antioxidant-supplemented diet was lower than that with the oxidized and control diet groups (P \u3c 0.05). Meat from birds fed the oxidized diet showed higher drip loss after 1 and 3 days of storage and greater 0−1 h post-mortem pH decline (P \u3c 0.05). Significant differences in specific SERCA activity in breast muscles from birds fed control and oxidized diets (P \u3c 0.05) were detected. This suggested that dietary oxidized oil induced oxidative stress in live birds and increased lipid and protein oxidation in breast muscle. Decrease in SERCA activity in breast muscles due to oxidative stress in live animals accelerated post-mortem glycolysis, which sped the pH drop after slaughter and increased drip loss, indicating that oxidation of diet can cause PSE-like (pale, soft, and exudative) conditions in broiler breast muscles