methods and theory, and advise on hoard selection, programming, cabling and cahle labeling (every 5 feet!). The chapter also touches on signal amplification and noise reduction. This is the information needed to hard wire older, still serviceable instruments with recorder outputs to a PC equipped with an inexpensive A D board. Chapter 4 expands on the need for noise detection and noise reduction and is the only chapter written exclusively by Becker. He covers sources of noise internal and external to the instrument, such as thermal, shot, A D quantization noise, shielding, ground loops, and optical isolation. A review of hardware and software filters, hoth analog and digital, including the important anti-aliasing problem, completes the chapter. Program codes are given for SavitzkyGolay filtering and forward and reverse Fourier transform (FFT) digital filtering; however, the explanation of the technical details of the latter is declared as being heyond the scope of the hook. Becker's discussion of the signal to noise ratio (SNR) is thorough and informative, although many experimentalists would not want to practice .rule of thumb in the lab, the SNR his must he larger than one to he able to detect the signal" (p 54). For most quantitative or analytical work, detection is not sufficient, and a SNR of a t least three is required. Six of the seven references to the literature are found in this chapter. The next three chapters are concerned with getting data into and out of the computer. "Digital Input and Output" (Chapter 5) applies to instrumentation with built-in A D conversion, as well as to simple an-off sensing and control. Practical methods of switch debouncing are introduced. The chapter also clarifies hit-masking and synchronization by "handshaking" with programming examples. Chapter 6 describes the IEEE-488 (GPIB) standard. Programs tailored to the National Instruments GPIB interface read H P 3478A digital voltmeters and demonstrate polling for asynchronous service. The serial data transfer protocols, RS-232-C and, briefly, RS-449 are covered in Chapter 7. Gates discusses the difficulties and pitfalls associated with using the RS232 "standard", which as he points out is "very confusing.. .not very rigid, and.. has heen utilized for purposes never intendHowever, since many existing deed.. vices are equipped with an RS-232 port, he suggests that you obtain a $35 gadget, called a break-out box, if you plan to connect such instruments "more than once or twice in your lifetime". Anyone who has struggled with a modem connection, or spent hours trying to connect RS-232 ports to everything from balances to spectrometers without the $35 gadget, will certainly approve of Gates' bias in favor of the IEEE-488 format. Three well-chosen programs: a simple serial interface, one using the XON-XOFF protocol, and a plotter driver for the Houston DMP-I round out the chapter. Chapter 8 looks a t t h e timers a n d counters needed to complete the control system. Chapter 9 condudes the first part of the hook with two programs that use timers to coordinate DIA, A D , and Digital 110. part 2, "Data Analysis", begins witb a discourse on how to, and not to, develop software (Chapter 10). Gates urges the reader to .avoid reinventing the transistor" (P
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160). He suggests using public domain software when available, talking to others, reading widely to see how similar problems can be solved and purchasing commercial packages, hut he doesn't address the trade off of purchasing an expensive software package the that mav turn out to be a lemon.. aeainst .. prrsonnl time required to "hnrk" it. Gates also suggests that the reader will frnd data analysis rasier than data collection and instrumentation control, since he need not contend with a "Medusa of cables, amplifiers, power supplies and switches". He distinguishes between sequential and random data files and then demonstrates plotting with programs to create a high resolution plot and a pseudo-three-dimensionalplot, including removal of hidden lines. Generic plotting routines, that are deviee-independent, are implemented by accessing the IBM Graphics Development Toolkit version of the Virtual Device Interface (VDI) system from Graphics Software Systems. The author explains how to install the device driver in the CONFIGSYS file. He also poinbout tha1,although ;he VI)I savesprogramming time, it may slow dowm program exrcution.'l'he chapter concluder with a gc. neric menu generation program and, most importantly, with suggestions on the need and structure of an electronic notebook. All of the information traditionally collected in a hound oaoer notebook must now have its counterpan on magnetic media, and in a form that is rallahle on-line (from n menu) for reading. witing, and printing. This test file must contain a sample description, instrumentation settings, and operator comments. Chapter 11alone could he worth the purchase price of the hook for the poor chromatographer. I t treats peak detection and provides a chromatography integration program. This is the longest program Listed in the hook and is designed to operate postrun, as it prohahly could not keep up with data collection on standard hardware. Chapter 12 covers digital image processing, a new area for microcomputer applieations and probably somewhat beyond the scope of most present users and their hardware. The chaoter is instructive in showine " how two-dimensional smoothing, filtering. or image enhancemenu are mrrely rxpansions of the one-dimmrional noise filtering algorithms discussed earlier and how simple nearest-neighbor pixel operations can profoundly change the visual appearance of an image. The third part on "Advanced Techniques" begins witb a description of Local Area Network (LAN) terminology and tapology (Chapter 13) and points out their limitations for high speed data transfer. LAN's are mare likely to he encountered in larger industrial and government installations than in academia. Methods to increase program speed by interfacing BASIC to assembly language routines with a CALL statement, and how to prepare for that statement, are discussed in Chapter 14. Interrupts and direct memory access (DMA), another way to speed data transfer, are covered in Chapter 15. Again, we are given sample programs in BASIC and in assembly language that are readily modified to our needs. In summary, we have an excellent hook that explains and teaches by word and by example. The 50 odd software routines, in~
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cluded on a 5'4 in. disk with the book (at a total price of 929.501, are a most attractive feature and present a convenient and inexpensive way to get started on laboratory automation. The exercises at the end of almost every chapter and the clear and logical exposition of problems and solutions make the hook eminently suitable for a one-semester, senior-level laboratory course on PC instrumentation interfacing. The authors demonstrate how to write well-structured code in universally availahle "Good Old BASIC". Moreover, with structured Microsoft QuickBASIC and its support for the 8087 math eoproeessor, hoth of which they strongly recommend, spaghetti code and the limitations on program execution speed are hoth eliminated. T h r book could use a glossary, and more refrrences to adr,anced work would he helpful. I'rrhaps, as recommended, most of the advanced reading can consist of a careful scrutiny of the manufacturer's instruction manuals for the availahle hardware. At any rate, these minor criticisms, easily remedied in the next edition. should not detract from the thrt that "Lahoratmy Autmmion using the 1BM PC" belongs in the lihrary of every scientist and engineer interested in learning how to perform experiments that require PC dataacquisition, and today, that means any complex or repetitive experiment. Gates and Becker have indeed provided the scientific communitv with a much needed compact, readable, ihformative, and practical hook. Frederic C. Laquer University of Nebraska at Omaha Omaha, NE 68182 and
Henry L. Laquer CWOPOWBT As~oclates P.O. Box 478
SEQS 3.0 Student Version Slmultaneous Equatlon Solver Edwin E. Tucker, CET Research Group, Ltd.. P.O. Box 2029, Norman. OK 73070 IBM Compatible, DOS 2.x to 4.x. either 5.25in. or 3.5-in. disk Component% Manual and disk Level and Subject: College. Simultaneous Equation Solver Cort: $250/10 programs. minimum order Hardware:
Summary Ratings: Category Ease of U s :
Below Average
Subject Matter Content: Pedagogic Value: Student Reaction:
GoDd Average Average
SEQS 3.0 is a program of considerable versatility for solving sets of nonlinear simultaneous equations. I t is issued in two versions, the professional version, capable of solving up to 40 equations with 40 unknowns and a total of 50 variables, and a student version, capable of solving up to 20 equations containing 20 unknowns and up to 30 variables. Array variables are not allowed, however. The user is assumed to be knowledgeable in setting up equations and (Continued on page A150)
Volume 67
Number 5
May 1990
A149
user must enter initial best guesses for the variables. Useful features include the ability to set constraints on variables, the errorhandling routines [preventing a program crash], and the ability to do m g e solving, where one variable mav,be held constant to ohtaina solution, then rariedasa parameter tc. obtain a cumplete set of solutiunr, as in calrulntingatitrnri~rncurve.Results may he graphed, and graphs, solutions, and equations sets may be saved far later reference. The documentation is supplied in e manual and appears to be quite complete and clear. I t indudes a chemistry example [species concentrations in a solution of a triorotic soeeies , ~~~-~as a function of oH1. There is no dorumentationor helpsupplied from wrthiu the p n w a m itself. No index is avaiinhle in the manual, but the Table of Contents is quite complete and can replace an index. The program behaves as described when using the examples given in the manual. SEQS requires uoapecial set-up. Requirements are DOS 2.x to 4.x. and 640K memory is highly recommended, especially with DOS 4.x. When the program is run, a short title screen first comes up. I t is followed by a small colorful screen described a s the Main Menu, giving a choice of function keys to be pressed to proceed. All other menu screens are presented in the same rather ambiguous format. Unless the manual has been studied closelv. ~, .much confusion can arise here. I t is a g w d idea to follow through all ofthe tutorials i n the manual hefore trying to use the program. Moving around in the program is easy and apparently foolproof. We never had it hang up from pressing the wrong key. In most cases, error statements pop up to explain errors, and corrections are given. Inuut is relativelv easv. . The user first types in the equotiom to be solved. Then, valuer are assigned to all quentifieri. Finally, each quantity is assignrd tcr be a ronstanr ur a variable. The solution process then proceeds. The solution process can be halted at any time to review or modify the equations or values. The versatility in giving names to variables should esoeciallv be anureciated. .. Concentrations, for example, can be denoted by brackets surrounding the chemical formula. Equations may include any standard mathematical function, ranging from square root to complex trigonometric funetions. The program includes more of these than are included in most high level programming languages. I t is not possible tolist or modify the program. SEQS is a general equation solving program, and, therefore, is applicable in a wide variety of situations. The solutions arrived at for chemical equilibrium problems and for a titration curve, at least, appear to he accurate, and agree with solutions arrived at by other methods. The course of iteration when determining a solutioncan be followed on the screen if desired, another useful feature. The SEQS program was given to students in the second semester of Physical Chemistry ttr review. They were asked to use it on their own, since the student version was supplied. The student reaction was generally not very positive. They found the pro~
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A150
Journal of Chemical Education
gram hard to use, especially in the Range Solve mode [where a parameter is varied to obtain a set of solutions]. The absence of help when running the program appeared to be part of the problem. Also, since equations must he entered before variables and constants are defined, the program appears to treat every quantity as a variable initially, which is confusing. One student commented that it wes not very useful for "practical" applications. Two factors would greatly improve this program. Firat, help should be available from the program, even if it is stored on the disk for reference as needed. Most word pracessors, for example, have such help available, as do many other programs such as spreadsheets. Secondly, the symbols for variables, parameters, and constants could be input before the equations are typed in, to prevent confusion and encourage students to carefully define their system. SEQS is a versatile equation solving program but appears to have rather limited use for students. The students who reviewed it have become rather good spreadsheet users during the last year and generally felt that most of what SEQS did could he done an a spreadsheet more easily. Indeed, they have calculated titration curves and have done most of their laboratory data reduction on a spreadsheet this year. Considering the cost of the program, and its limited utility to students, a shareware spreadsheet such as ASEASYAS (Lotus 1-2-3 compatible costs about $45 for a registered copy) by Trius, Inc. of North Andover, Massachusetts, is to be preferred. I t has, in addition to the usual spreadsheet features, the ahility to do matrix manipulation, solve simultaneous linear equations and perform linear regression, which most spreadsheets do not have. Articles on using spreadsheets to solve chemical equilibrium problems, like those that SEQS can solve, were presented recently in thts Journal (I). In addition, a recent issue of Journal of Chemical Education: Software described the use of spreadsheets in Physical Chemistry, and included templates for many common topics (2). One pedagogical objection to the program is that it removes the student one step further away from a knowledge of chemical equilibrium. A student need not know that a buffer solution is formed during an aeidbase standardization titration, or that at the endpoint the solution consists of a single salt, for example. All that is necessary is to type in the equations and assign values. On the other hand, to get the program to give a complete solution often requires considerable experience or advanced knowledge of what should happen. We could not get the general equations far a titration curve to give a correct solution if the volume of added titrsnt was zero. An instructor would understand why this happens. For a student it could lead to considerable frustration. Having acopy of SEQS available [the professional version] makes sense, however. In research or general advanced class work, the necessity of solving sets of complex, seemingly intractable equations can arise. Usually, without a program like SEQS, the solutions would be difficult if not impossible. Having SEQS available promotes the solution of problems that otherwise might not be attempted but could lead to interesting insights or conclusions.
I. Cad W. David, J . Chom.Educ 1989.66, A237 Stephen LPharne, J. Chem Edue. 1989. 66. A239; Clyde Metz and HanryDanafo,Jr.. J . Chem.Educ. 1989.66.A241. 2. David W. Whimant, Journnl of Chemical Education: So/iuore 198%JIB Na 1
K. E. Dierenteldt COncoMia College Maorhead. MN 56562 The Language of Blotechnology: A Dlctlonary of Terms John M. Walker and Michael Cox. American Chemical Society: Washington. DC. 1988. viii 255 pp. 14.6 X 22.6 cm.
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$49.95. HB $29.95 PB.
Today few science-related areas figure as prominently in the news medra as biotechnolow, defined by the lexicographers ofthis volume as "the practical application of biblogical systems-to the ma&facturing and service industries and to the management of the environment." As a recent hook review aptly points out (MacQuitty, J. J. Chem. Eng. News 1990,68(3), 42)), communicating hiotechnology to the nonexpert is difficult hut vital. Yet the problem goes deeper than this. Despite the widespread interest in biatechnology, the problem of understanding it applies to scientists as well as the general public. The field is so broad and uses the techniques of so many specialized areas (e.g., molecular biology, microbiology, pharmacology, biochemistry, organic chemistry, and chemical engineering) that scientists frequently work in interdisciplinary groups, involving researchers educated in different areas and approaching their projects with different backgrounds and different vocabularies. The authun of this dictionary under review, both readers at the Hatfield Polytechnic. Hatfield, Herts. England, have a t rempted -succrssfully in my pinion-"to define routinrly used apecralized language in the various areas irf bLtechnoloa\." so as to standardize the terminology i n i d a common language and thus help workers understand the language or jargon of their collaborators. Despite its size constraints, the volume offers lucid, authoritative definitions of a wide and balanced selection of termsfrom "abomasum" to "zygomycotima"-from the various fields most likely to cause communication problems in an interdiseiplinary research group. Replete with clear equations and diagrams, it deals with terms and concepts from microhial biochemistry and physiology, molecular biology and genetics, genetic engineering, animal and plant cell culture, enzyme and protein technology, fermentation technology, biochemical engineering, process control, downstream processing, and waste and environmental toxicology. This ACS Professional Reference Book deserves a prominent place on the shelf of biotechnolagical research and development firms as well as university and professional libraries. I t also belongs in the reference collection of any scientist or educator who must communicate with colleagues in other fields. George B. Kauffman Califmla State University. Fresno Fresno. CA 93740
