Inexpensive +5V digital power supply - Journal of Chemical Education

Jul 1, 1977 - Inexpensive +5V digital power supply. Neil Jespersen. J. Chem. Educ. , 1977, 54 (7), p 460. DOI: 10.1021/ed054p460.3. Publication Date: ...
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Fads in Science Teaching

To the Editor: R. W. Parry's Provocative Opinion, "Fads in Science Teaching" [J.CHEM. EDUC., 52, 706 (1975)],has accomplished a t least one of its goals: it has provoked me to respund. 11' fads are both good and had as Dr. Parry suggests, it s after the tads should be ~ossibleto use their good ~ o i n t long themselves are gone and forgotten, except by trivia experts. Indeed the ideal timr fur a more ratiunal assessment of possible eood noints would be after the mitlal "exaeeerated zeal and levot;on" have subsided. A good idea s h A d never be discarded because of its oriein. It does seem extreme, however, to equate serious attempts a t solving the problems of society with fads. The fact that many of these attempts appear silly or misdirected only demonstrates that most . oeoole. . . including .students and even professors, do not understand the interwoven complexities of the problems at hand. Nor is our society blessed by those "capable and imaginative leaden with far-ranging intellectual skills," whom Dr. Parry mentions. Thus our problems will remain unsolved or be transformed into different ones through inadequate solutions until someone is able t o recognize and analy& their various parts and implications. Interdisciplinary studies represent one possihle approach since thev can orovide a broader ~ersoectivefor viewing problems-~tis unfortunately true that they are often "trendy" and do not orovide the in-death trainine: necessarv to advance beyond s u p h c l a l understanding. As &idence that this need not hanoen. .. . thr medical sciences have traditionally followed an integrated approach on the premise that disease and treatment of anv. orean .. or svstem in the bodv reverberate thnmghout the entireorganism. A problem cannot be neatly localized and treated bva snerinlist with no training outside his own specialty. For this reason, Dr. Parry's choice of the example of Harvard medical students does not seem a particularly apt comparison. In addition, the switch to a different kind of "multidisciplinary study" was accompanied by the abolition of grades, a factor that Dr. Parry ignores as he at-

tributes the subsequent poor performance of students on National Board Exams soiely to the interdisciplinary approach. I feel certain that he does not treat scientific evidence so- cavnlierlv. -Interdisciplinary studies are certainly no universal panacea and I would like to suggest another approach. Instead of Dr. Parry's rather idealized model of physics, chemistry, and bioloev as eieantic niles in the bedrock of mathematics. I propose a different and unfortunately, much closer analogy. Each of these basic sciences is like a vertical shaft sunk through the increasingly dense layers of mathematics. Numerous sours of subsoecialties radiate out from these main shafts bui very few of ihem ever connect, even though they are freauentlv close to each other. Such spurs may be separated by only afew inches of earth, yet thetraveling distance between them via the main shafts is very great. While these tunnels must of course be enlarged and shored up to prevent their collapse, each scientist will not solve many problems by merely digging deeper in his own particular niche. Solutions would be found much more efficiently with a network of interconnecting tunnels among the various shafts and spurs, through which scientists could learn more about the exact locations of their own research. Communication just at the top (as in Dr. Parry's model) too often reflects the self interests of those a t the ton and there is no indication that this will change in the future. Interconnecting tunnels would allow scientists to communicate with each other a t all levels as well as enable them to enlarge their perspective beyond that of each scientific niche. There is no question that they need indepth disripline training hut thnti,? itself is not enough-at the \.er) least they need additional under;tand~ngof the significance oi their wurk within a irheme of knuwledpe larger than iust srientit'ic. I helieve that this would motivate as well as enable scient~ststa communiwte thrir scientific knowledge to persons outside their sperialtv, e\Tn outs~dethe w i e n t ~ t ~ c coknunity. It is only through communication that scientists (and others) can channel their diverse and complementary knowledge into the concerted efforts necessary to solve our problems.

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Richard E. Rice Michigan State University East Lansing, 48824

Volume 54. Number 7, July 1977 1 459

To the Editor: I am delighted to see that Mr. Rice has responded to my provocative opinion article on "Fads in Science Teachine." iprovorati& opinion should promote some response. 1 am grateful to him fur taking the time to write. 1would, however, like to make a few comments on each of the points made by Mr. Rice. Paragraph 2 - ~ k seem to agree here. As stated in my original article, fads are both good and bad and their good points should be exploited. Paragraph 3-This is a matter of opinion. Fads can indeed have their origins in serious attempts to solve the prohlems of society, hut they are fads none-the-less. As a case in point, most of our environmental problems are still with us to avery serious degree, but the exaggerated zeal and devotion which marked the presentation a few years ago of much environmental science has now faded. Without making value judgments one would have to categorize much of that effort as a teaching fad which had the highest of motives and which had some positive results, but did not remove the societal problem upon which it focussed. "Fads are both good and bad." In my opinion the teaching fads arising from the "Sputnik" era had much good in them. I can only agree heartily with Mr. Rice in his belief that technical prohlems in the real world are extremely complex. We differ in our prescription for that method of education which would make the most progress in . solving these prohlems. My thesis is that the solution of complex problems will demand cooperation of people who have been educated in depth along discipline oriented lines. Specialists in basic disciplines who work together in a learning mode are my prescription for an attack on societal problems. Paragraph 4-Mr. Rice's opinion relative to the use of inter-disciplinary studies is an interesting one. The question which remains is: can one obtain the broader . perspective and . the in-depth training from a multidisciplinary course without chaneina student abilities, teacher skills, and/or time of exposure. As Mr. Rice notes such courses "are often trendy and do not provide the in-depth training necessary to advance beyond superficial understanding." This is my concern. That medical problems can not he neatly focused in any one discipline is beyond debate; and medicine is not unique. However, medicine, like all branches of scientific activity, has been broken into basic and well recognized segments such as anatomy, etc., for purposes of pedagogy. The Harvard experiment involved a swing away from these traditional disciplines toward a more "multi-disciplinary" teaching of medicine centered around orean svstems. Mr. Rice has raised a;alidobjection relative to the use of the Harvard experiment in this discussion. Indeed more than one variable is involvea and a superior example would have been one which did not involve the grading parameter as well, hut such an example was not available. If,howeuer, one insists that only one variable at a time be changed, most educational experiments must be rejected. Instead of considering that the Harvard example involved only two variables one must recognize that it actually involved many variables-different people, different times, different lectures, etc. In very few social or biological experiments does one have absolute control over all the variables. Interactions of variables are important. On the other hand, to claim that the negative results of the Harvard experiment should be ascribed completely to the grading practice and not a t all to course organization would seem to be the ultimate in wishful thinking. A package change was instituted. Paragraph 5-Each person is entitled to his own model. In mv opinion the overview is better from a platform than from a tunnel. As the physical and biologicai problems become better defined one will be in a better position to build platforms to the rising towers of the social sciences. unfortunately, our technical ignorance does not always stimulate confidence 460 1 Journal of Chemical Education

in our advice to social scientists, (i.e. problems of nuclear wastes, ozone, etc). In any event the form of the model is of minor imnortance. Ifone disregards the od horninern arguments in the middle Dart of Mr. Hire's fifth ~araeraoh.a communalitv of ronvirtion can be detected. w e a;eeathat students need in-depth discioline trainine. We also aeree that thev should develoo a " personal philosophy which permits them t o view their work in relation to the larger intellectual community around them. We further agree upon the importance of communication. The maior point of difference remainine between us is: what is the best way to achieve these goals? The message of my article is that the best approach to the real and difficult problems facing the world will demand the cooperatioe efforts of specialists with strong discipline oriented training. Such specialists may come from mathematics, physical sciences, biological sciences, social sciences, the humanities, law, or any other area delineated by the nature of the problem under attack. In my judgement such discipline oriented trainine will be more effective than broader. hut more superficial inter-disciplinary training. This is the point a t issue.

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R. W. P a r r y The University of Utah Salt Lake City, 84112 Isolation of Dyes for Analysis To the Editor: Regarding the recent article, "Separation and Identification of Some FD & C Dyes by TLC" [H. T. McKone and G. J. Nelson, J. CHEM. EDUC., 53,722, (1976)], readers may he interested in a reference to a simple alternative technique for the isolation of dyes from beverages, gelatin desserts, and other foods as well. The use of a basic ion exchange resin for this purpose is detailed in the Food and Drug Administration oublication No. 57 entitled "Identitv of Svnthetic Colors in ~ o o d sFDA's , Science Project series'. In this pamphlet eight dves are identified bv. paper .which. . chromatoeraphv. - . . Using ever of the two isolation procedures is most convenient, the two experiments might he combined into an experiment on identification of food dyes and an experiment comparing two important chromatographic techniques. Alfred S . Levinson Portland State University Portland, Oregon 97207 lnexpenslve +5V Digital Power Supply T o the Editor: Digital electronics are becoming increasingly important in the rhemistrv lahoratow. We have found that in many instances, the need for a small circuit for timers, strobes,-etc., will require the purchase or building of a +5-V power supply. These range from $20 for a bulky home huilt device to more than $100 for wtted, high current commercial devices. The problems of cost or ronsiruction time can he avoided by the purchase of simple "battery eliminator" devices used for home video eames. These are readilv available. inex~ensive(SS-10) and are usually rated a t 5 . 5 - f ~with 100 d c a p a c i t y , sufficient for manv oroiects. Usuallv one can eet awav with usine the power s u 2 y directly. If a voltage closer to 5 v is needed; a simple Zener diode circuit will provide the appropriate output. ~

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Neil Jespersen University of Texas at Austin Austin, 78712