Tuesday, July 15, 2014

First one up the drive (Economist, July 12, 2014)


In reading about electronic cars in the new edition of The Economist, I was reminded about an important difference between capacitors and batteries. Since I only touched on this topic in coursework in college and grad school, my background in this area is rather weak. The following reinforced for me the difference in the amount of energy created by both:

"Unlike batteries, which store energy chemically in the material of their electrodes, a capacitor stores energy physically, on the electrode's surfaces. One electrode has a surplus of electrons and the other a deficit. If the electrodes are then connected through an external circuit a current flows until the surplus has neutralised the deficit and both have the same electrical potential. Electrodes surfaces are easy to get to, so a capacitor can be charged and discharged quickly, giving it a high power-density. But surfaces cannot hold as much energy as entire volumes, so capacitors have lower energy-densities than batteries."

Monday, January 13, 2014

Creative Intelligence: a book review



Creative Intelligence: Harnessing the Power to Create, Connect, and Inspire
Bruce Nussbaum. 2013. New York, NY: Harper Business. [ISBN 978-0-06-208842-0. 352 pages, including index. US$28.99.]

In a constantly changing world of science, business and technology, there is much speculation over what drives innovation, intelligence, and entrepreneurship. Is there a way to assess someone’s ability to create a successful business, as Steve Jobs and Mark Zuckerberg did? Nussbaum argues throughout his book Creative Intelligence: Harnessing the Power to Create, Connect, and Inspire, that although the abilities of Jobs and Zuckerberg are hard to measure objectively, there are concrete skills associated with their success. These skills are not gems of a genius; we can practice them in our daily life. Nussbaum argues that they are the heart of entrepreneurialism and that creativity is the backbone of a new emerging theory of Indie Capitalism—an economy based on the idea that creativity drives capitalism. Overall, he argues that although we think geniuses are born with innate abilities, many of their eureka moments were the result of years of hard work.
Nussbaum, himself an expert in design and innovation, had a career quest to tie together a common trait of successful companies like Facebook and Apple. Was it the number of patents awarded or the amount of money spent on research that resulted in such powerful and transformative companies? He determined “creativity” to be their common component.
He identified five competencies of creativity:
·         Knowledge Mining: Steve Jobs’ integration of calligraphy into the Apple computer is based on his having audited a class on calligraphy for fun during college.
·         Framing: Crowdfunding on the Internet changed fiscal sponsorship from a practice of the wealthy to a community endeavor open to anyone with Internet access. Many small donations now compete with the National Endowment for the Arts in the amount of money raised.
·         Playing:  SimCity (video game) teaches people city planning by turning it into a game.
·         Making: Web sites for marketing products online have allowed “homegrown” to become mainstream and accessible to everybody.
·         Pivoting: The creation of Instagram illustrates the most basic pivoting. Burbn was a location check-in app that was not successful. The photo app within the program, however, received a lot of traffic. The founders ditched their original business and eventually sold Instagram to Facebook for billions.
            All are fluid skills that we can practice, hone, and perfect. Many of Nussbaum’s arguments advocate a liberal arts education where specialization dos not occur. He argues that it is the person’s passion for a topic that unleashes creativity. Although idealistic, Nussbaum’s arguments are unrealistic. A liberal arts education, while considered a well-rounded survey of subjects, cannot be tied to an increase in salary or any kind of promotability within the business world.
            Overall, Nussbaum believes we are moving toward a more creative economy. Indie Capitalism is the new wave. In August 2012, Apple became the most valuable company in history based on its capability to create and rewrite the ecology of computers. Nussbaum argues that the skills of creativity will birth more Apples in society and drive our economy to new heights of excellence.

Sunday, September 15, 2013

Nebraska farming, 4H and technology updates



As the daughter of a Nebraska farmer turned city slicker, I watched 4H from afar during my childhood in suburban Seattle. Several of my cousins were involved in the sewing and cooking arm of the organization (yes, the girls- sexist I know) while most of my cousins (male and female) participated in raising livestock, plants, and showing their photography, among other activities. It always reminded me of a girl/boy scout organization or even Indian Princesses- organized crafts and outdoor activities designed to boost character, build the community and promote family unity.

An article in the latest Economist taught me that 4H has historical roots, ties with federal funding and an agenda tied in with the university culture in America. All of this has greatly influenced the way farming has evolved to promote genetically modified (GM) crops, farming as a capitalistic industry and a setup to supply the world's growing food demands. This is very different from the European model of preserving the traditional forces in the market and promoting farm practices which may be more humanitarian but not necessarily capitalistic.

On the surface, you would never know that 4H was founded, in part, to promote the hard sciences. The acronym stands for head, heart, hands and health (all four beginning with "H").  Current science projects with the organization involve egg incubators in classrooms (for urban kids) designed to teach them that their eggs do not originate at McDonald's. The money for these projects comes from government and public universities from gifts of federal land- this was set up during the Civil War and was designed to integrate technology into society. I'm guessing specifically farm culture since this is where the organization seems most active.

The historical origins of 4H are deeply rooted in the drive for new technology and farming practices to be integrated into the rural culture. In the late 1800s, the midwest plains were populated by pioneers - originally of all types of European descent- land was parceled out and homesteaders started their farms. All the while the goal of this distribution was to convert the farming techniques of these newcomers to new and (I'm assuming ) more efficient practices. (This makes sense when you think of the disposition of the average pioneer- already out of their comfort zone by coming to a completely different place) Congress sent representatives out to introduce new ways of planting hybrid corn or canning tomatoes, for example. When resistance from adults prevented new technology from being adopted, the 4H movement began. People were more likely to adopt, for example, hybrid corn, when they observed their children's 4H hybrid corn growing taller and healthier than their own.

All of this history has influenced the overall differences in how Americans view agriculture as opposed to how Europeans view it. In America, agriculture is a commodity- a capitalistic business designed to reap the highest profit possible. This is not the case in Europe where more traditional methods are used, often at the expense of turning the maximum profit or even keeping up with demand.

I had no idea my cousins' childhood pastime had such historical roots and educational goals.

Tuesday, July 30, 2013

Improved Test Scores: Why and How


Standard Learning Objective Quiz Results for Introductory Chemistry


 
Fall 2012 Results

 
2/19 students got 8/8

5/19 students got 7/8

3/19 students got 6/8

6/19 students got 5/8

2/19 students got 4/8

1/19 students got 3/8

 
Spring 2013 Results (after implementation of online homework system)

4/21 students got 8/8 

5/21 students got 7/8

4/21 students got 6/8

5/21 students got 5/8

3/21 students got 4/8

 
These scores are, I believe, proof that an effective online homework system can make an overall difference in student comprehension. Especially in a discipline like chemistry, it is so easy to complete a homework assignment and not understand what overall concepts were reinforced by that assignment. An online homework system can give students the chance to complete an assignment, receive tutorial help with the assignment and real-time feedback on the accuracy of their answers. Then later they can go back and redo the problem for review (practice for the final exam).

As you can see from my small sample size, more students in my class scored 6,7,8 (out of 8) after the implementation of an online learning homework system.

Monday, July 15, 2013

"Evolution is a theory the way gravity is a theory."





In an article about creationism vs theory of evolution on Slate posted here, Laura Helmuth makes a statement I'd like to correct. In chapter one of my introductory chemistry text, I require my students to know the difference between a law and a theory. Apparently, Laura Helmuth needs to review her introductory science and familiarize herself with this difference.

Yes, evolution is a theory. It is a large-scale explanation about how life on earth evolved: it includes supporting data, scientific laws, a series of tested hypotheses, and an overall picture of what the process entailed. It is a model of nature. And like any model, it has flaws. It provides us with an imperfect, incomplete picture of what happened over billions of years. It cannot be easily, readily and completely tested and proven over and over again.  Just like any theory, new data may tweak it at any time. There are endless hypotheses to test about this theory. I am sure we do not have complete information, to date, about the evolutionary process. It is an incredibly complex process.

This is in contrast to the scientific law of gravity. The law of gravity holds true over and over again (on earth anyway) based on repeated observable circumstances. You can drop a ball a thousand times and it will always fall toward the ground. It is a repeated observation for which there is no complexity, no unanswered question or further investigation to be done. (This excludes the behavior of gravity on a subatomic scale or out in space.)

Thank you for the article, Laura. I just want to make sure all of your vocabulary is correct.



Tuesday, July 02, 2013

Transforming Matter: A History of Chemistry from Alchemy to the Buckyball (Johns Hopkins Introductory Studies in the History of Science)

This is the book I pulled off of amazon.com last year and designated as my project for the year. This book and about ten other books of varying subjects. No, I haven't finished it yet but I'm close. My goal is to review it for this blog. Between hosting my in-laws, preparing for baby Shamon #2 and finding a new house, life is really busy right now.

A blog entry is certainly overdue. I  hope to return soon.

Wednesday, April 03, 2013

Limiting Reactant/Reagent




3 FeO(l) + 2 Al(l) → 3 Fe(l) + Al2O3(s)



This is the best I could do for cutting and pasting a useful equation from my PowerPoint slides. The superscripts and subscripts do not carry over.

If you have 25.0 grams of each reactant, which is limiting?
How do you approach this problem?   Divide 25.0 grams by the molar mass of each reactant. (71.85 g/mole for FeO and 26.98 g/mole for Al). This gives you moles of each reactant. You cannot compare grams to grams (as given in this case) because it is a nonsensical relationship in chemistry terms. You must compare moles to moles. Now, use moles of each reactant to figure out which gives the LEAST amount of product. This is where you use your balanced chemical equation to find the molar ratio of reactant to product. In this case you have 3 moles of Fe(l) for 3 moles of FeO(l). Essentially this is a 1:1 relationship. So your moles of reactant for FeO is the same as moles of product of Fe(l). For Aluminum, you have 3 moles of FeO (from the coefficient of the balanced equation) for every 2 moles of aluminum. Therefore it is a 3/2 relationship of moles of product to moles of reactant.  

Although you can compare moles of product from one reactant to moles of product from another reactant to determine the limiting reagent, many times this number is converted back into grams by multiplying by the molar mass of the product you are dealing with.  


The comparison in this case is between 19.4 grams of Fe(l) (from 25.0 grams of FeO) versus 77.6 grams of Fe(l) from 25.0 grams of Aluminum. By definition, the limiting reactant is the one that gives the least amount of product. Therefore, the Iron II oxide is the limiting reactant. The 19.4 grams of product is your maximum amount of product from these two given amounts of reactant, or in other words, it is your theoretical yield.