Abstract Huge progress has been made in the development of three dimensionally printed tissue structures. With the use of cells, three dimensional printers, and CAD drawing software, donor identical structures can be fabricated. However, cell scaffolds currently lack significant mechanical integrity which can result in reduced cellular survival, attachment, and nutrient delivery. For this reason, multiple strategies have been developed to increase and improve mechanical stability within engineered constructs without having to sacrifice cell viability. The hypothesis of this paper was that incorporating Perfluorotributylamine (PFTBA), a greenhouse gas, with single walled carbon nanotubes (SWCNT), a allotrope of carbon with a cylindrical nanostructure, into an alginate scaffold will not only increase mechanical integrity but also cell survival. The following objectives were proposed: 1. Fabricate and characterize cell laden scaffolds of alginate and 2. Assess the addition of perfluorotributylamine and various concentrations of carbon nanotubes inside of cell laden scaffolds of alginate. Three configurations of perfluorotributylamine and carbon nanotubes were explored in an effort to maximize mechanical properties and cytocompatibility. Perfluorotributylamine was combined with gelatin from bovine skin and phosphate buffered solution to form a PFTBA emulsion. This emulsion was added to each alginate scaffold to encompass 5% of the entire alginate scaffold. Single walled carbon nanotubes were added in increasing concentrations to have four scaffolds, one control, 0 µg/ml, .1 µg/ml, and 1 µg/ml. The results of this study indicate that the configuration of 5% PFTBA emulsion + 1 µg/ml SWCNT + alginate, provided the best cell viability results; Picogreen fluorescence of 8532, excellent viability in live/dead stain, and sufficient morphological features while the control scaffold, containing alginate only, provided the best mechanical properties after a 7 day period. The results contradict the hypothesis that mechanical properties will increase with increasing SWCNT concentration, but support the hypothesis of improved cell viability with the incorporation of PFTBA emulsion to increasing SWCNT concentration.

This study investigated the thermal performances of platinum particles when coupled on a steel support, under the application of a radio frequency (RF) field. Platinum nanoparticles were reduced on the surfaces of type-316 stainless steel balls, based on published methods of Pt reduction from chloroplatinic acid. Alternatively, 1wt. % Pt/Al2O3 commercial catalyst pellets were mixed with stainless steel balls and investigated for hydro-deoxygenation of pyrolysis oil from pine sawdust biomass. The catalysts were placed inside an electric insulator tube suspended within a looping copper coil connected to the induction heater, and heated at different power levels. An infrared camera was utilized to record the surface temperature profile during heating of Pt-coated balls and non-coated balls. Pt particles deposited onto silica beads showed no surface heating when placed inside an RF field. The Pt-coated steel systems, however, showed rapid heating of the surfaces following a first order response. The catalysts were characterized via SEM/EDX, XPS and XRD. Preliminary upgrading tests using these Pt-steel balls did not indicate any effect. The lack of catalytic activity was attributed to the limited surface area per unit volume of the Pt coating due to the large sizes and non-porous structure of the steel balls. For the catalytic upgrading experiment with the use of the Pt/Al2O3 commercial catalyst pellets mixed with steel balls, heating of the catalyst bed with the induction heater was compared with a conventional method of heating using electric tape around the catalyst bed reactor. Partial deoxygenation was successfully achieved in the catalytic upgrading of pyrolysis oil using Pt/Al2O3 pellets mixed with steel balls at 234°C, with the use of the induction heater. The molar O/C ratio of the oil decreased from 1.36 to 0.51. No deoxygenation was observed using the conventional heating method with the electric tape under identical conditions as both carbon and oxygen appeared to be removed at approximately equal rates, with the carbon being deposited in the form of coke onto the catalyst instead of being recovered in the liquid.

<p> Among all nutrients that are important for crop production, nitrogen (N) is one of the least efficiently utilized, mainly due to its high mobility in soil. The possibility of using crop sensing in real-time to detect variability in N deficiency within a field has the potential to enhance N efficiency, increase crop yield, and reduce potential environmental risks and crop production costs. Potassium (K), another important crop nutrient, can also lead to higher yield when applied in the right amount and manner. Real-time fluoro-sensing is a new technology for crop sensing and studies have shown that it could enable variable rate nutrient management for precision agriculture practices. The objective of this study was (1) to evaluate if fluorescence sensing can detect variability of N and K in crop canopy at early growth stages of maize (prior to V6 crop growth stage) under controlled condition (greenhouse), (2) to evaluate the effect of different fertilization dosages of N over the plant growth, and (3) to verify if induced fluorescence can detect <i>in situ </i> N variability at early growth stages of maize. Research was conducted in two stages, first in a greenhouse condition and later in field spread over three site-years. The greenhouse research was conduct in year 2011 and plants were grown in plant-pots with silica sand and supplied with modified Hoagland solution with different rates of N and K. Field trials were conducted in year 2012 and 2013 in northern Colorado. For the greenhouse study, data collected via fluorescence sensor (Multiplex^&reg;3) were analyzed using ANOVA and Tukey&rsquo;s HSD to test significant differences among treatments in each experiment. For the N experiment, regression analysis between the seven fluorescence indices and N uptake was performed for the 12 days of data acquisition at five different growth stages (i.e. 2-leaf to 6-leaf growth stages) and coefficient of determination was used to identify the best fluorescence indices to detect N status. Also, root mean square error (RMSE) was used to test the precision of the estimates for each index. Results of this study indicated that all fluorescence indices were able to detect N variability in maize canopy prior to V2 growth stage. However, the fluorescence indices failed to identify K deficiency as the maize plants with K treatments showed small variability at early crop growth stages. For the field study, two site-years had 5 N rate treatments applied as UAN 32% (urea ammonium nitrate; 32-0-0), while one site-year had 6 N treatments applied pre-planting. Sensors used in this study were the Multiplex^&reg;3 for fluorescence sensing and the GreenSeeker^&reg; for reflectance sensing (NDVI). Sensor measurements were correlated with aboveground biomass, N content, and N uptake measured at two growth stages (V6 and V9 maize growth stage). The aboveground biomass, N content, N uptake, yield, and sensors readings were analyzed using ANOVA and Tukey&rsquo;s HSD to test significant differences among the N treatments. Also, a regression tree between N uptake and the fluorescence indices was fitted along with the coefficient of determination (R²). The N rates had no effect on aboveground biomass, N content and N uptake (for both sampled growth stages). Under field conditions, fluorescence indices failed to detect N variability in maize at early growth stages for all three site-years. This finding may require further investigation, as for most of the N treatment plots, maize plants had sufficient N levels and another biotic or abiotic stress may be responsible for unexplained differences in N variability as measured by fluorescence sensor. Contrasting findings under greenhouse conditions versus field conditions limit the application of fluorosensing sensor. Further field studies are needed to evaluate the potential of this sensor for detecting N variability <i>in situ.</i></p>

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