presses doubts about Porter's claim that DEFGAN is "a single substance." It's more likely, Lee tells C&EN, that separate crystals of both phosphate and nitrate salts are present but are intimately mixed in the product. Partial separation of the salts from an aqueous mixture is possible, he says, but not easy. Fainberg, too, notes that differential solubilities in organic solvents might allow separation. But do additives really work? Will they defang ammonium nitrate? Some U.S. observers point to European requirements for additives in FGAN. But David J. Heather, deputy director-general of the U.K.'s Fertilizer Manufacturers Association, tells C&EN that European regulations focus more on what must be excluded from or limited in FGAN to make it less sensitive to heat or detonation, rather than on what must be added. Thus, limits are set for oil retention (the more oil absorbed, the more explosive), for amounts of carbon, chlorine, and copper (which make FGAN more sensitive), and for particle
size distribution (the more dust, the more explosive). Requirements for desensitizers do exist, but only for Northern Ireland and the Republic of Ireland, Heather adds. There, only calcium ammonium nitrate—a mixture of calcium carbonate and ammonium nitrate—is allowed. The salts can be separated, Heather notes, "but terrorists here do not try to take out the ammonium nitrate from the material. Most of the bombs are believed to have been based on calcium ammonium nitrate, but [terrorists] have to go through a lot of operations to make it into an explosive device." He speculates they grind the material to very fine particles and mix it with other ingredients. Ostrowski and Fainberg agree it would take only a few weeks' work to establish the feasibility of Porter's process, both in effectiveness and in resistance to simple chemistry. Those eager for this technological fix for terrorism will have to wait for results of such studies. Maureen Rouhi
NSF to fund college chemistry reform plans The National Science Foundation will give grants totaling nearly $11 million to four university consortia for development of fundamental changes in the teaching of undergraduate chemistry. The NSF program, "Systemic Changes in the Undergraduate Chemistry Curriculum," will enlist some 50 institutions in five-year efforts at curriculum development, evaluation, and dissemination. "We expect that the cooperation within the [consortia] among faculty from a variety of institutions and disciplines will establish new models for designing and disseminating curricular changes," says Robert F. Watson, director of NSF's Division of Undergraduate Education. Indeed, he adds, "The projects that have been funded hold promise of bringing about dramatic changes in the undergraduate chemistry curriculum—including substantial integration of the study of chemistry with the study of other science disciplines, and greatly increased abilities of students to work with one another in exploring and solving meaningful problems in the sciences." NSF announced the initiative two years ago, drawing 112 responses to its first call for proposals. It awarded
$50,000 planning grants to 14 groups in January 1994 (C&EN, Jan. 31, 1994, page 25) and has now chosen four of them for full-scale funding. Members of each consortium range from large universities to four- and two-year colleges. All four groups emphasize new teaching methods, includ-
Watson: promise of dramatic change
ing active student participation, interdisciplinary approaches to teaching chemistry, and curricula based on topics important to students and society. The projects put special emphasis on modifying curricula to meet the needs of students who expect to teach in elementary, middle, or high school, or who are pursuing two-year degrees in advanced technology fields. One consortium, led by the University of Wisconsin, Madison, will get $3.8 million for its project, "Establishing New Traditions: Revitalizing the Curriculum." It will redesign courses to emphasize student involvement and use information technology and computers as learning aids. Interdisciplinary course clusters will enable students to form learning communities and integrate their studies into selected areas in the sciences and humanities. The principal investigator is John Moore of the Wisconsin chemistry department. The City College Consortium, based at City University of New York, will get $1.5 million to develop its "Workshop Chemistry Curriculum"—focusing on creating a new learning culture in chemistry at all undergraduate levels. For example, introductory courses will include student-led workshops and mentoring by students who have recently completed the course. The principal investigator is David K. Gosser of CUNY City College's chemistry department. Beloit College, Beloit, Wis., leads the ChemLinks Coalition, which will receive $2.7 million for its project, "Making Chemical Connections." This group will cooperate with the ModularChem Consortium, led by the University of California, Berkeley, which has a $2.9 million grant for its project, "Sweeping Changes in Manageable Units: A Modular Approach for Chemistry Curriculum Reform." Principal investigators Brock Spencer and C. Bradley Moore are based at the Beloit and Berkeley chemistry departments, respectively. The two groups will develop complementary sets of modular course materials, each focusing on a real-world problem. The modules will introduce important core concepts, show links between chemistry and other disciplines, and create a flexible model for curriculum reform. Faculty members using the modules will select topics and concepts to create courses meeting the needs of their students and schools. Linda Raber MAY 29,1995 C&EN
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