( )Engineering Information Abstracts Part II118

Title: DESIGN OF FREELY PROGRAMMABLE LABWIN-DOWS rrrrr CVI-BASED REAL-TIME SIMULATORS FORTESTING INDUSTRIAL CONTROLLERS

( )Author s : Metzger, M.Corporate Source: Technical Univ of Silesia, Gliwice, PolSource: Systems Analysis Modelling Simulation v 30 n 1-21998. p 153-165 CODEN: SAMSEC ISSN: 0232-9298Publication Year: 1998Abstract: The new LabWindowsrCVI programming environ-ment from National Instruments is designed for instrumenta-tion, control, data acquisition and visualization of processes,but may be also useful for development of real-time simula-tors. These simulators may be used as freely programmabledevices for testing industrial controllers. The simulator, pre-sented in the paper, provides a possibility of industrial processmathematical description by the differential equations as wellas a possibility of industry-standard signal connection to eachcontroller being tested. On the base of simple example, pro-gramming manners with the most important part of the pro-

Ž .gram are presented. Author abstract 28 Refs. In English EIOrder Number: EIP98044168102Keywords: Control system analysis; Real time systems; Com-puter software; Computer systems programming; Control sys-tem synthesis; Differential equations; Graphical user inter-faces; Industrial applications; Control equipment; Computersimulation

Title: GROWING WITH WIRELESS( )Author s : Fuller, Bruce

Corporate Source: Fluke Corp, Everett, WA, USAŽ .Source: Sensors Peterborough, NH v 15 n 4 Apr 1998. p

45-48 CODEN: SNSRES ISSN: 0746-9462Publication Year: 1998

Ž .Abstract: Wireless data acquisition DA is a viable and cost-effective method of transmitting data over long distances,through electrically noise environments, and from hostile loca-tions. Not every DA application is suitable for RFDA becauseof cost considerations; however, the reliability and flexibilityof advanced wireless technology warrants serious considera-tion for many industrial applications. Engineers who are famil-iar with the capabilities of this useful tool can take advantageof the technology in the more challenging DA environmentsand reap cost and performance benefits that rival those ofhard-wired systems. In English EI Order Number:EIP98044166320Keywords: Radio systems; Data acquisition; Spread spectrumcommunication; Modems; Data communication systems; Fre-quency hopping; Radio links

Title: RATE-CONTROLLED INDENTOR FOR IN VIVOANALYSIS OF RESIDUAL LIMB TISSUES

( )Author s : Pathak, Arvind P.; Silver-Thorn, M. Barbara;Thierfelder, Christopher A.; Prieto, Thomas E.Corporate Source: Marquette Univ, Milwaukee, WI, USASource: IEEE Transactions on Rehabilitation Engineering v 6n 1 Mar 1998. p 12-20 CODEN: IEEREN ISSN: 1063-6528Publication Year: 1998Abstract: A tissue tester was designed to enable rate-con-trolled indentation of the bulk soft tissues of lower extremity

residual limbs. The tissue tester employs a digital linear actua-tor that implements rate-controlled indentation, and a loadcell that measures the reaction force resulting from tissueindentation. Viscoelastic phenomena such as preconditioning,hysteresis and force relaxation can be assessed, and the effectof varying indentation rates on soft tissue stiffness can beinvestigated. The device accommodates indentor excursionsup to 30 mm, indentation at rates of 0 to 10 mmrs, reactionforces up to 44 N, and multiple loadingrunloading cycles. Thetissue tester is controlled via a notebook personal computerwith a PCMCIA data acquisition card. The tissue testing trialsare automated and the entire test system is portable andamenable for use in a clinical or research environment. Sys-tem output consists of force-displacement curves from cyclicloading, and force-time curves following ramped-step indenta-

Žtion. The mean indentor positioning error was 0.071 plus or.minus 0.75 % of the desired displacement. This error varied

as a function of indentation and was approximately indepen-dent of the indentation rate. Indentation rates were accurate

Ž .to within 0.94 plus or minus 0.68 % of the desired value andalso varied with indentation. Indentation of a viscoelasticfoam yielded force-displacement curves that were consistentwith that obtained from an Instron universal testing machine.Ž .Author abstract 24 Refs. In English EI Order Number:EIP98044145906Keywords: Human rehabilitation equipment; Tissue; Biome-chanics; Automation; Personal computers; Testing

Title: STUDY OF SLUG CHARACTERISTICS FOR TWO-PHASE HORIZONTAL FLOW

( )Author s : Marcano, R.; Chen, X.T.; Sarica, C.; Brill, J.P.Corporate Source: Univ of Tulsa, Tulsa, OK, USAConference Title: Proceedings of the 1998 InternationalPetroleum Conference & Exhibition in Mexico ConferenceLocation: Villahermosa, Mex Conference Date: 19980303-19980305Source: Proceedings of the SPE International Petroleum Con-

Ž .ference & Exhibition of Mexico 1998. Soc Pet Eng SPE ,Richardson, TX, USA. p 213-219 39856 CODEN: 002322Publication Year: 1998Abstract: Understanding the behavior of multiphase flow inpipelines is an important factor in the safe and economicaldesign and operation of multiphase systems. Slug flow is acommon and very complex occurrence in these pipelines.Sixty-two slug-flow tests were conducted over varying combi-nations of gas and liquid flow rates. A total of 25,975 slugswere generated, ranging from 23 to 1145 slugs per test. Theflow loop consisted of a 3.068-in diameter, 1378-ft long hori-zontal flowline, a two-stage air compressor, a centrifugal pump,and a data acquisition system utilizing LabVIEW with a Mac-intosh II ci computer. The primary data collected during theexperimental tests consisted of continuous readings of pres-sures, temperatures, flow rates, and liquid holdup. Processingof this data yielded slug translational velocities, slug lengths,pressure drops, slug length distribution, and slug frequency.Analysis of the results showed that the slug length distributionfollowed a Lognormal pattern. New correlations were devel-