More Cases by Lantz and Walczak



The Benign Hamburger | Hommers Mining Dilemma | A Case in Point 
The Bridge of Mandolin County
 
| Well Wishes
 


The Benign Hamburger
by Graham Peaslee, Juliette Lantz and Mary Walczak
J. Coll. Sci. Teaching, 28(1), 1998, 21-24.  
Get The Benign Hamburger Case and Case Teaching Note

Synopsis:

Jill-at-the-Grill hamburger fast food chain must decide the future of their company. A recent outbreak of E. coli bacteria in hamburgers sold in their restaurants has resulted in at least one death and over two hundred reported cases of food poisoning. The company CEO has assembled all his top aides for an emergency meeting to update the situation and decide what steps the organization should take to reverse the economic plunge company stock has taken in the last few days. They are considering introducing irradiated beef into their products to prevent another such catastrophe and to restore the publicâs confidence in their restaurants. Concern about the safety of the irradiated food and the publicâs acceptance of this process is brought forth.

Case Objectives:

Chemical Principles: principles of electromagnetic radiation, interaction of radiation and matter,
chemical bonding, distinguish between atomic and nuclear energy scales
Analysis Principles: application of nuclear science beyond the basic definitions, examine some of the
myths of nuclear technology, and examine the societal, political, and economic
issues surrounding the science of food irradiation
Related Skills: research a topical and controversial subject; learn to separate fact from opinion
and valid information sources from editorials, advance scientific literacy skills

develop critical thinking skills and learn to support arguments and opinions with
facts, apply risk-benefit analysis principles

Use of the Case:

This case was developed for use as an introduction to nuclear applications aside from those involving nuclear power generation and weapons. As such, it can be used in a variety of introductory science courses.

Introductory Chemistry
Topics that would be especially appropriate for this audience include nuclear processes and the effect of radiation on matter. The discussion could focus on an explanation of how irradiation works to kill disease-causing microorganisms, the range of the electromagnetic spectrum and the interaction of various energies of light with molecules, and the public perception of the nuclear industry and technology.

Environmental Chemistry, Environmental Science
Topics that would be especially appropriate for this audience include the difference between various nuclear technologies (food irradiation, power plants, bombs) and the safety of any nuclear facility. The discussion could focus on the level of scientific literacy necessary to function as a responsible citizen, world food supplies and food preservation technologies, government regulatory functions, and the harmful effects of various radiation dosages.

Introductory Biology Topics that would be especially appropriate for this audience include bacteria and the public policy issues related to food irradiation. The discussion could focus on bacterial infections, the role of bacteria in the human GI tract, the role of bacteria in food preservation technologies, the history of various epidemics, FDA regulatory policies, and the societal issues resulting from such a proposition.

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Hommers Mining Dilemma
by Juliette Lantz and Mary Walczak
appears in: J. M. Lantz and M. M. Walczak,
The Elements of a Chemistry Case:

Teaching Chemistry Using the Case Discussion Method,
Chem. Educator,
1(6), 1997, S 1430-1471 (97) 06070-6.

Synopsis:

A mining company in northern Wisconsin is faced with a dilemma. The copper ore that they have been mining is nearly depleted and the other ore on their site is of a fundamentally different type. This ore will require pyrometallurgical refining, as opposed to the hydrometallurgical processing that has been done with the other ore. The company founders explore possibilities of processing the ore on site cognizant of the environmental harm which may be inflicted. Since they are highly committed to preserving the environment, they explore options which minimize the environmental effects of refining. They must decide which course they will follow, and their decision will be made public in a press release scheduled to appear in the next day's news.

Case Objectives:

Chemical Principles: galvanic vs. electrolytic electrochemical cells, combining the appropriate
half-reactions to result in a desired net reaction, spontaneity in chemical
reactions, temperature dependence of cell potentials
Analysis Principles: introduce copper mining in general and pyrometallurgy and hydrometallurgy in
particular
Related Skills: think about the social, political, economic, and environmental issues associated
with a course of action taken by a company
Use of the Case:

This case was written for a second semester general chemistry . However, as the analysis focuses on manipulating half-reactions to determine if a copper-producing reaction is spontaneous at 950°C, it could also be used in a variety of other courses where other aspects of the case could be emphasized.

Introductory Chemistry
Here, students typically need some help setting up the calculations, but can effectively carry them out once started. Splitting the class into sections that focus on one aspect (e.g., one temperature) of the calculations and then drawing the groups back together to answer the "Is it feasible?" question works well.

Analytical or Physical Chemistry
In an upper level analytical or physical chemistry class, the students could be expected to progress through the analysis more rapidly with little assistance. The class could focus on the outcome of their decision on the surrounding town and businesses, and on the mining industry itself. A physical chemistry class might do the whole analysis in terms of free energy, while an analytical course might stick solely to the use of cell potentials.

Environmental Chemistry, Environmental Science, Introductory Geology
In environmental chemistry classes the instructor might focus on the smelting as an origin of the acid rain precursor, the nature and effects of heavy metal contamination, strip mining vs. shaft mining, land reclamation, mine runoff, and a comparison of hydrometallurgy and pyrometallurgy. With some adaptation, this case could also be used in introductory geology or environmental science courses. Topics to focus on for these courses include the environmental consequences of ore removal from the earth and the regional nature of ore deposits.

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A Case in Point
by Mary Walczak and Juliette Lantz
J. Coll. Sci. Teaching, 28(3) 1998 152-57.
Get the A Case in Point Case and Case Teaching Note

Synopsis:

A manager of a scientific consulting firm has approval to hire an entry level scientist. Since his group already covers the basic fields of science, he has the freedom to hire someone without having to fill a vacancy in a particular expertise. From the five applicant portfolios in front of him, the employer has pulled out the performance evaluation letters which have been written by faculty familiar with the students and their work. He must choose one applicant to invite for an interview later that week.

Case Objectives:

Scientific Principles: promote undergraduate research, internships, independent projects, advanced writing,
close interaction with faculty, and computer proficiency as valuable experiences
for undergraduates
Pedagogical Issues: motivate students to embrace active learning pedagogies in their science courses,
and begin fostering a classroom atmosphere that is conducive to student involvement

serve as an ice breaker in the first week of class, to promote camaraderie and
group skills in the classroom.

Related Issues: introduce students to the case discussion method as a valuable active learning pedagogy

prepare students for their next life transition, from college to a career. To help
students consider ways to make themselves employable and competitive in the job market.

Use of the Case:

This case was developed to motivate students to participate in active learning activities. Although different goals apply, the case is equally applicable with upper and lower level students.

Introductory Level
For the introductory level, this case is designed to be used at the very beginning of a course, preferably on the first or second day. It is designed to be equally useful in any type of science course at an introductory (majors or non-majors) or advanced level, in any field from chemistry to environmental science to biology. The case motivates students for active learning pedagogies throughout the course, and also demonstrates how they can use their course work to gain skills that may make them employable. For best results, the instructor should follow this case with a handout or discussion of what active learning strategies will be employed in this particular class.

Upper Level
This case can also be used to allow upper-level students to explore the transition from college to a career, and help them translate their education experiences into marketable skills. It can serve to inspire students to take a more active role in their full educational endeavor, and to consider research, internships, independent projects, etc. as activities that are vital to their professional development.

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The Bridge of Mandolin County
by Juliette Lantz and Mary Walczak
J. Chem. Educ., 1999, 76, 1671-2.
Abstract

Synopsis:

The members of the Mandolin town council must decide how to budget for the deicing of the townâs new bridge which gives them direct and easy access to the nearest cityâs shopping and medical facilities. Two viable deicers, rock salt and calcium-magnesium-acetate (CMA) are considered, both of which make claims to be the more effective deicing product. The town council must examine these claims in detail from a chemical, economic and environmental standpoint, and appoint a task force to take on this assignment and make a recommendation.

Case Objectives:

Chemical Principles: analysis involves molar masses, ionic compounds and ions, polyatomic
ions, aqueous reactions and solubility rules, and colligative properties
Analysis Principles: critical reading skills and problem formulation - how can two advertisements
each claim that their product is better, and how can these claims be quantified?

compel students to gather information by experiment in a laboratory setting,
and to bring their findings to bear upon their individual deicer choices

Related Skills: impart the difficulties in assigning monetary costs to environmental damage
and concerns, and to learn about the economics behind environmental decisions
Use of the Case:

This case was designed to be used early in the semester of a general chemistry course, as it covers chemical principles such as molar mass, ions and ionic equations in water, solubility rules and inorganic nomenclature. The case requires students to do a substantial amount of calculations and unit-conversion type problems. The case is intended to be used over two class periods, with a laboratory period in between. A variety of laboratory exercises are provided; any combination of these is optional for this case. Due to the wide range of laboratory exercises, the focus on fundamental chemical principles and calculations and the overriding environmental themes, this case can successfully be used without adaptation in non-majors chemistry or environmental chemistry courses, or upper level analytical or environmental chemistry courses.

Laboratory Experiments:

Well Wishes:  
A Case on Septic Systems and Well Water Requiring In-Depth Analysis and Including Optional Laboratory Experiments
by Mary Walczak and Juliette Lantz
J. Chem. Educ., 2004 81(2) 218-20.
Abstract


Synopsis:

Standing water over a septic system drain field causes new homeowners to become concerned about the quality of their well water and the viability of their septic system.  Upon testing the well water, they find it contains high levels of nitrate, a species known to cause health problems. The amount of nitrogen generated daily by the household (as measured in the septic system effluent) is the basis of the case analysis.  Students convert all nitrogen-containing species to nitrate and account for groundwater and aquifer dilution.  After comparing the measured well water nitrate levels with calculated values, the septic system can be either ruled out or identified as the source of hazardous nitrate levels in the well water.  Based on this analysis, the homeowners must find a way to improve the quality of their well water and determine whether their septic system needs to be modified or replaced.

Case Objectives:

  1. To engage students in analysis involving the following chemical principles:  the calculation of solution concentrations (especially ppm), the use of stoichiometry to obtain the concentration of a variety of species in solution, the dilution of solutions and their subsequent concentrations, aqueous reactions (especially redox reactions) and an introduction to the carbon and nitrogen cycles as they pertain to wastewater.
  2. To teach students critical reading skills, problem formulation and advanced analysis skills by evaluating a complex real-world problem and developing a problem solving strategy.
  3. To unify the goals of the classroom and laboratory by leading students to determine that information for the case analysis must be gathered by experiment in a laboratory setting, and by requiring them to bring their experimental findings to bear upon the classroom discussion of the case. 
  4. To impart how a septic system functions to purify household wastewater and the environmental impact of using septic systems.
  5. To examine the consequences of an individual’s actions on the environment in his/her daily life, including the concepts of sustainability and sustainable lifestyles.
Use of the Case:

This case is designed for use in general chemistry to develop the concepts of solution concentrations and solution stoichiometry, aqueous redox reactions, and the carbon and nitrogen cycles in wastewater.  Optional lab exercises involving water analyses for nitrate and chloride are included, along with suggestions for making these experiments role-playing exercises.  This case can be used over 2-5 class periods and 0-2 lab periods.  Suggested variations combining two, one or no lab components are provided.  Due to its challenging analysis and environmental focus, this case can also be used without alteration in analytical or environmental chemistry. It is also appropriate for courses intended for non-science majors.

Laboratory Experiments:

The Benign Hamburger | Hommers Mining Dilemma | A Case in Point 
The Bridge of Mandolin County
 
| Well Wishes
 


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