Microcomputer-based systems

Bond et al. [791 ] studied strategies for trace metal determination in seawater by ASV using a computerised multi-time domain measurement method. A microcomputer-based system allowed the reliability of the determination of trace amounts of metals to be estimated. Peak height, width, and potential were measured as a function of time and concentration to construct the database. Measurements were made with a potentiostat polarographic analyser connected to the microcomputer and a hanging drop mercury electrode. The presence of surfactants, which presented a matrix problem, was detected via time domain dependent results and nonlinearity of the calibration. A decision to pretreat the samples could then be made. In the presence of surfactants, neither a direct calibration mode nor a linear standard addition method yielded precise data. Alternative ways to eliminate the interferences based either on theoretical considerations or destruction of the matrix needed to be considered. 

The Laboratory Information Management System (LIMS) has achieved wide recognition as a powerful tool for increasing the productivity and quality of service of the analytical laboratory. Systems have been developed that range from inexpensive microcomputer based systems to half-million dollar or more large, minicomputer based systems. In addition, many firms have already developed or acquired custom systems tailored to their specific needs(1-8). 

Smith et al. (1989) monitored continuously the in-trathoracic content of intravenously injected inindium labeled platelets in anesthetized guinea pigs using a microcomputer-based system. 

The advent of microcomputer-based systems such as those described here provides a new opportunity for individuals to store and manipulate personal and proprietary data. Small data collections of up to a few thousand compounds can be stored to keep track of new research, inventories, and laboratory data. Such information has traditionally been kept in card files or unindexed file folders. When stored as a PC-based structure file, this data can be rapidly searched and specific information easily retrieved and evaluated. 

Dow, J.A.T., Lackie, J.M. and Crocket, K.V. (1987). A simple microcomputer-based system for real-time analysis of cell behavior./. Cell Sd. 87, 171-182. 

This system is an industrial microcomputer-based system with an user program support SoFIC (Software for Industrial Controller) implementing control algorithms primarily of logical and regulation character. The use of efficient communications enables to build remote complexes ranging from middle to large control systems. 

Contreras, M.L. Deliz, M. Galaz, A. Rozas, R. Sepulveda, N. A Microcomputer-based system for Chemical Information and Molecular Structure Search . <7. Chem. Inf. Comput. Sci. 1986,26, 105-108. 

B. A. Boukamp [1984] A Microcomputer Based System for Frequency Dependent Impedance/Admittance Measurements, Solid State Ionics It, 339-346. 

The application of on-line computers to electrochemistry developed rather slowly, owing to the early problems associated with the interfacing and, perhaps more significantly, to the high costs. Both of these obstacles have been largely overcome. It is now possible to purchase a microcomputer based system capable... 

One problem with the specification of design requirements is that everyday natural language is not always precise or unambiguous enough for the purpose. The result of discussions between the engineers and the customers for whom microcomputer-based systems are developed should be a document that sets out the agreed requirements for the system. The following six requirements for such a document are recommended. 

The project work at thr Institute of Nuclear Science and Technology, Bangladesh, developed a microcomputer based system for on-line monitoring, display and storage of all operational parameters and information of the 3 MW TRIGA reactor. The system is now running satisfactorily. 

The Control and Instrumentation group of Reactor Engineering and Control Division is engaged in R A D works in automatic control based system, and control A instrumentation of nuclear reactors. Under this project a microcomputer based system is being designed and developed to automatically monitor and record all operational parcuneters and relevant Information of the reactor in an efficient manner. 

Programmable Logic Controller (PLC) A microcomputer-based solid-state control system which receives inputs from user-supplied control devices such as switches and sensors, implements them in a precise pattern determined by instructions stored in the PLC memory, and provides outputs for control or user-supplied devices such as relays and motor starters. 

Both electronic and microcomputer-based controls require information about the state of the controlled system. Sensors convert different physical variables into an electric signal that is conditioned and typically converted to a digital signal to be used in microcontrollers. The trend in the construction techniques of modern sensors is the use of silicon microstrnctures because of the good performance and the low cost of this type of device. In the energy control scope the main quantities to be measured are the temperature, pressure, flow, light intensity, humidity (RH), and the electric quantities of voltage and current. 

In context with methane detection during offshore oil drilling, another infrared fiber optic methane sensor was reported25. The detector comprises 3 main units a microcomputer-based signal processing and control unit, a nonconducting fiber optic gas sensor, and an optical fiber cable module. The system operates at an absorption line of methane where silica fibers have very low losses. 

A microcomputer based control and data acquisition system is required to monitor the 10 thermocouples in the sample and to control the heater temperature. For the latter, the rate of change of the thermocouple in the slab was used and power to the cartridge heaters varied. Details are given by Duever (3) and in a WCPD report (4). 

Early on, it was anticipated that many repetitive calibrations and EMF measurements would be carried out in the evaluation of a large quantity of electrodes. The first microcomputer-based automated titration system utilizing high level software (CONVERS) hastened these studies (10), as did a more recently constructed minicomputer system (Figure 1). Typical results are shown in Figure 2, where a set of five protriptyline CWEs were calibrated simultaneously (11). Graphic side-by-side comparison of different electrode calibrations was also useful in establishing structure-selectivity relationships. 

Osakai et al. used a microcomputer-controlled system for the ion transfer voltammetry procedure [20]. The system used is based on a NEC PC-9801 microcomputer, which was designed by using a polarizable oil-water interface as an ion-selective electrode surface. The system was applied to the determination of acetylcholine ion by cyclic, differential pulse, and normal pulse voltammetry at the PVC-nitrobenzene gel electrode. The amperometric measurement was carried out with voltage pulses of short durations and constant amplitude. 

The increasing use of microcomputer-based computer-aided drafting (CAD) systems is making these tools available to the whole design team, not just to the drafting professionals. Thus, applications other than pure drawing sometimes arise. 

C.E. Camp, W.B. Kolb, K.L. Sublette, and R.L. Cerro, The Measurement of Square Channel Velocity Profiles Using a Microcomputer-Based Image Analysis System, Experiments in Fluids I0 S1 (1990). 

The development environment for expert systems includes both hardware and software. Initially, most of the expert systems were developed on microcomputers. However, as shown in Figure 2, there is a steady increase in the number of minicomputer or workstation based systems. This is due to a variety of factors, the most common of which is that the PC systems run out of computer "space" before they can solve a complex problem due to the size of the code and other operating requirements. The IBM compatible PC-AT is still the most common development platform because it is a very widely distributed system and provides the broadest user base. However, the limit of 640K of random access memory is causing programmers to undertake ingenious solutions to fit their code into this space. 

The POTW EXPERT system demonstrates that a microcomputer-based expert system can effectively represent a complex evaluation methodology, evaluate the capability of a secondary wastewater treatment facility s major unit processes, detect factors which potentially limit performance, and categorize them according to their influence on plant performance. The model is presented in a logical and structured manner to allow wastewater professionals unfamiliar with the CPE process to effectively employ this wastewater treatment methodology. 

To meet these constraints, we chose for our development tool Insight 2+, a rule-based and microcomputer-based expert system shell that met most of the criteria of a good tool, as described by Waterman (2)—that is, it has good user interface, rule-tracing, and debugging capabilities. In addition, Insight 2+ has no requirements for licensing fees. 

Corp. model 174A polarographic analyser with an RE0074 x-y recorder (Shalders et describe a microcomputer-based alternative system),... 

In electrothermal atomization methods, the microcomputer also controls the furnace temperature, a key factor for this technique. Guevremont and Whitman used a microcomputer based on a Z80 microprocessor for the automatic control and data acquisition from a graphite furnace [13] they could heat the furnace from 0 to 2500 C In about 3 s, with an approximate gain In precision of 50% under the control of the microprocessor. The system Is shown schematically In Fig. 10.9. The automatic functions afforded are data acquisition, measurement of the furnace temperature and calibration, temperature programming, control of the gas flow, control of the sampler and delivery of results. 

Microcomputer-based front ends to on-line systems... 

---