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Conversion of bio-oil from flash pyrolysis of biomass is a way to produce useful renewable feedstocks for the chemicals industry. Dehydration of pentanediol (1,5- and 2,4-pentanediol) was investigated over CeO2, CeO2-Ga2O3, and CeO2-In2O3 catalysts at 250–350 °C. Adding Ga or In (20 mol%) improved the conversion of pentanediol over CeO2, but adversely affected selectivity. In the base case, 1,5-pentanediol was converted on CeO2 to 4-penten-1-ol and 1-pentanol, desired linear alcohols, together with unwanted cyclopentanol and cyclopentanone byproducts. Adding gallium or indium to ceria increased the selectivity towards undesired cyclized products like tetrahydropyran and tetrahydropyran-2-one due to increased acidity. In the base case, 2,4-pentanediol converted on CeO2 to unsaturated alcohol (e. g., 3-penten-2-ol > 74 % selectivity), but adding Ga or In promoted acid-catalyzed cracking. Tuning the acid-base characteristics of ceria significantly alters the product distribution.

The hydrogenation of carbon dioxide over K-promoted FeCo bimetallic catalysts prepared by sequential oxalate decomposition and carburization of FeCo with CO was studied in a fixed-bed reactor at 240 °C and 1.2 MPa. The initial CO2 conversion was found to be dependent on K loading, whereas both unpromoted and K-promoted FeCo catalysts (except 90Fe10Co3.0K) exhibited similar levels of CO2 conversion after a few hours of time on stream. A decarburization study on freshly activated and used FeCo suggests that potassium increases the stability of iron carbides and graphitic carbon under a reducing atmosphere. Also, K addition tends to decrease the hydrogenation function of FeCo bimetallic catalysts and, thus, controls product selectivity. Under similar CO2 conversions, potassium enhanced acetic acid formation while suppressing ethanol production, which indicates that a common intermediate might be responsible for the changes observed with C2 oxygenates.

Vapor-phase catalytic dehydration of 2-octanol was investigated over CeO2-CaO mixed oxides at 300°C and atmospheric pressure. Ca doping to a molar composition of 75Ce25Ca increased the activity for 2-octanol dehydration, while further increases in Ca content detrimentally affected conversion. Catalyst surface area and pore volume increased with increasing Ca content in CeO2-CaO mixed oxides. Hydrogen TPR profiles indicate that the partially reduced state of surface ceria (i.e., Ce3+), which increases with increasing Ca loading, might play an important role in promoting activity. This is analogous to our earlier work [Appl. Catal. A: Gen. 394(2011) 105-116] on low temperature water-gas shift, where a promoting effect of Ca-doping was observed with ceria supported Pt catalysts. In that case, TPR, TPR-XANES, and DRIFTS measurements indicated that Ca enhanced both O-mobility and reducibility of ceria by weakening the Ce-O bond.

The effect of solvent on the hydrogen-deuterium isotopic homomolecular exchange over a traditional Fischer-Tropsch cobalt catalyst (25 % Co/Al2O3) was investigated using a plug flow reactor at two different reaction temperatures (room temperature (26 °C) and –20 °C) and at atmospheric pressure. In this study, three different solvents were tested, including n-pentane, n-hexadecane, and C-30 oil. The consumption of H2 and D2 is the same, and the concentration of the HD produced is twice the consumption of H2 or D2 at dry (without solvent) conditions. At room temperature and at –20 °C, conditions without solvent exhibited 100 mol% exchange with the formation of H2:HD:D2 having a 1:2:1 ratio. For n-pentane solvent, the exchange rates were ∼97 and ∼80 mol% at 26 and −20 °C, respectively. For the n-hexadecane and C30 oil solvents, the initial exchange rate was ∼50 mol%, with the exchange rate decreasing over time. The lower exchange rate with the n-hexadecane and C30 oil solvents, and also n-pentane at –20 °C, is likely due primarily to the limited mobility of reactant molecules in the liquid-filled pores of the catalyst. Blocking or covering of the pores of the catalyst depends on the molecular mass and density of the solvent. No isotopic partitioning preference was observed at two different temperatures and various solvents for the active cobalt catalyst.

Twenty-eight seventh and eighth grade students were randomly assigned to two treatments and a control as they entered the Florida State Museum. All subjects were given set induction materials saying in effect: (1) Treatment-Study the wall panel which is part of the cave exhibit and describes the many biologic relationships and organisms in the cave at the cave entrance. Continue into the cave and study the habitat. When you exit the cave you will be given a test to see how much you learned; (2) Treatment II-Enter the cave and study that habitat. When you exit at the other end, study the wall panel which is part of the cave exit and describes the many biologic relationships and organisms in the cave. After studying this panel you will be given a test to see how much you learned; (3) Control-You will take a walk through exhibits depicting a variety of Florida Habitats and later see a film on the Habitats of Florida that are represented in the museum. Then you will be given a test to determine how much you know about one type of habitat. Both treatments and the control spent equivalent time at their tasks and were confronted with either the cave exhibit as described or the equivalent control experiences. A 25 item criterion test was designed to measure the acquisition of conceptual and factual knowledge and specific attentional factors relative to both the cave and the instructional panel. A Kr-20 indicated that this instrument had a reliability coefficient of 0.80. It was anticipated that the panel, used as an attention directing and controlling device prior to entering the cave (Treatment I) or upon exiting the cave (Treatment II), would function as a forward-shaping or backward review prompting adjunct, hence both should be significantly more effective than the control. This was confirmed (df 2,28; F 8.09) p < 0.01. It was also expected that the forward shaping panel would be more effective than the backward review panel in the tradition of inserted questions in prose research. Although the differences were in this direction, they were not significant (p≤ 0.10).

Modified atmosphere (MA) storage in conjunction with refrigeration has been shown to significantly increase the shelf life of fresh fish and other products, but the effects, if any on the outgrowth and toxigenesis of C. botulinum are unknown. A commercial system was duplicated in the laboratory and the effects of modified atmosphere on the outgrowth of C. botulinum types A, B, and E were observed in inoculated salmon fillets and sandwiches stored at 4.4°C and 22.2°C. Inoculated samples stored in air at the same temperatures were used as controls. No toxigensis was observed in either the air or modified samples stored at 4.4°C, but all inoculated samples held at 22.2°C were toxic within 2–3 days. Spoilage generally preceded toxigenesis. In a concurrent study, the tendency of CO2 environments to repress the growth of gram negative bacteria to a greater extent than gram positive bacteria was also noted.

Natural History Museums, Science Centers, Zoos, and Aquaria contribute considerably to out-of-school science experiences for visitors of all ages and characteristics. With birth rates and school age populations declining, it is likely that people will be looking to these settings for rest, recreation, stimulation, and learning. Science educators can play a leadership role in research, development, and in utilization of these settings to achieve learning and motivational objectives which support, supplement, and extend school science learning. But what is the current “state of the art” in this area? This article reviews relevant past studies, proposes a taxonomy of exhibits in museum settings, and focuses attention on factors which should be considered when studying learning in these settings. In addition, it presents some potentially productive methods of conceptualizing research, and suggests possible future lines of research for the science educator.