1,239 research outputs found
Catalysts-Looking Back and Peering Ahead
No full textCitation: Hohn, K. L. (2017). Catalysts-Looking Back and Peering Ahead. Catalysts, 7(2), 1. doi:10.3390/catal7020041I am pleased to report on the latest happenings at Catalysts. It is gratifying to me to look back at where we’ve been and what we’ve accomplished, but also inspiring to peer ahead to how we will grow and improve
Remembering ICC 16
No full textCitation: Hohn, K. (2016). Remembering ICC 16. Catalysts, 6(10), 1. doi:10.3390/catal6100153Every four years, a group of outstanding individuals, the best in their field, come together from all over the world. These individuals have spent years learning their craft, and now they assemble to show what they can do. Such a gathering happened in 2016
Feature papers to celebrate the landmarks of catalysts
No full textCitation: Hohn, K. L. (2015). Feature papers to celebrate the landmarks of catalysts. Catalysts, 5(4), 2018-2023. doi:10.3390/catal5042018Catalysis is a critical scientific field that underpins much of the world’s chemical industry. For example, it is often quoted that catalysis plays a role in 90% of all industrial chemical products. This importance has led to numerous academic journals and specialized conferences on the subject, as practitioners seek outlets to publish their cutting-edge research on catalysis
A New Year of Catalysts
No full textCitation: Hohn, K. L. (2016). A New Year of Catalysts. Catalysts, 6(1), 2. doi:10.3390/catal6010016Excerpt: Welcome to a new year of Catalysts, an international, peer-reviewed open access journal. From time to time, I like to write about the status of the journal: what milestones have been reached, what special issues will be coming out, what conferences we will partner with, etc. As we turn to the New Year, this seems like an opportune time to provide an update on Catalysts
What's in a Number?
No full textCitation: Hohn, K. L. (2015). What's in a Number? Catalysts, 5(3), 1304-1305. doi:10.3390/catal5031304People like to distill complicated phenomenon into easily digestible numbers. Whether it’s a top ten list of the best movies of all time, the shooting percentage of our basketball team’s star, or a student’s score on an exam, we like to quantify phenomenon that is unquantifiable. We like the comfort of a number which we can use as the basis for our decisions. This is an imperfect process, as underlying human behavior can, ultimately, not be boiled down to a single number. But we try anyway
Production of methyl ethyl ketone from biomass using a hybrid biochemical/catalytic approach
No full textThe recent demand for sustainable routes to fuels and chemicals has led to an increased amount of research in conversion of natural resources. A potential approach for conversion of biomass to fuels and chemicals is to combine biochemical and chemical processes. This research used microbial fermentation to produce 2,3-butanediol, which was then converted to methyl ethyl ketone by dehydration over a solid acid catalyst. The fermentation process was performed using the bacteria Klebsiella oxytoca (K.O). 2,3-butanediol then dehydrated to form methyl ethyl ketone on a solid acid catalyst, the proton form of ZSM-5, and heat. The goal was to determine the reaction kinetics of 2,3-butanediol dehydration over ZSM-5, and to demonstrate the hybrid biochemical/thermochemical approach for synthesizing chemicals from biomass. It was found that ZSM-5 produced methyl ethyl ketone with high selectivity (greater than 90%), and could convert fermentative 2,3-butanediol to methyl ethyl ketone. The reaction order of 2,3-butanediol dehydration was found to be slightly large than one, and an activation energy of 32.3 kJ/mol was measured
The shaping of student knowledge: learning with dynamic geometry software
No full textThe focus of this paper is a software genre usually referred to as ‘dynamic geometry’ because of the ability of the user to dynamically manipulate geometrical figures created with the software tool. Using data from a longitudinal study of 12-13 students’ use of dynamic geometry software, the focus of the analysis is on the interpretations the students make of geometrical objects and relationships when using this form of software. The analysis suggests that the students’ mathematical reasoning is shaped by their interactions with the software in that their ability to explain geometrical facts and relationships evolves from imprecise, ‘everyday’ expressions, through reasoning that is overtly mediated by the software environment, to mathematical explanations of the geometric situation that transcend the particular tool being used. Such findings suggest that curriculum initiatives that encourage the use of dynamic geometry software are appropriate but that the incorporation of such software into classroom practices is unlikely to be straightforward
Ethanol fermentation from food processing waste
No full textThis study focuses on the use of restaurant waste for production of ethanol. Food wastes (corn, potatoes, and pasta) were converted to ethanol in a two-step process: a two-part enzymatic digestion of starch using alpha-amylase and glucoamylase and then fermentation of the resulting sugars to ethanol using yeast. Because of the low initial composition of starch in the food waste, low ethanol concentrations were achieved: at best 8 mg/ml ethanol (0.8 % by mass). Ethanol concentration increased with increasing enzyme dosage levels. Calculations were conducted to evaluate whether waste heat from restaurant waste could be used to drive flash vaporization to purify ethanol. If the solution produced by fermenting food waste is flashed at a temperature of
99.7°C, 77% of the ethanol is recovered in a vapor stream with 1.14 mole% ethanol (2.87 mass %). Waste heat could provide over a third of the energy for this vaporization process. If 4 mole% ethanol could be produced in the fermentation step by increasing the initial starch content in the waste solution and improving the fermentation process, then a single flash at 98.9°C will recover nearly 99% of the ethanol, giving a mass concentration of ethanol of 10.3%, which is similar to that achieved in industrial grain fermentation
The jingling Geordie: community arts and the regional culture of the North East of England
No full textIn the light of the massive economic and social changes which have affected the North East of England over the last 25 years, the author assesses the vitality of the indigenous culture and reflects upon current cultural trends and the North East’s future, particularly in relation to a regional Europe. He traces the folk-tradition of the region and looks at ways in which this can be drawn upon to develop a meaningful link between past and present. He looks closely at the changing nature of class-relationships in the North East and reflects upon how a valid local culture can survive in a multi-cultural society. He draws upon his own extensive experience in Community Arts, looking at definitions of the term in the new political climate and arguing for its positive contribution to the cultural debate. He dwells on the issue of regionalism and devolution in a new Europe, comparing the situation in the North East of England with political and cultural changes in Scotland and other parts of the United Kingdom
The mediation of mathematical learning through the use of pedagogical tools: a sociocultural analysis
No full textA sociocultural analysis suggests that pedagogical artifacts employed in the teaching and learning of mathematics both enable and constrain learning. This paper summarises three classroom studies of mathematics learning that have utilised a sociocultural approach. Each of the studies indicates how insight can be gained into the ways in which students attempt to make sense of the mathematics they encounter
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