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Retention and graduation rates for engineering disciplines are significantly lower than desired, and research literature offers many possible causes. Engineering learning communities provide the opportunity to study relationships among specific causes and to develop and evaluate activities designed to lessen their impact. This paper details an engineering learning community created to combat three common threats to academic success of engineering students: financial difficulties, math deficiencies, and the lack of a supportive engineering culture. The project tracks participants in the learning community from first year through graduation to assess the effectiveness of its activities in improving retention and graduation rates. Scholarships were made available to address the financial difficulties; tutors, mentors, study groups, and a “freshman-to-sophomore bridge” summer program were provided to address math deficiencies; cohort engineering courses, active learning techniques, required group meetings, required group study sessions, dedicated study space, and dedicated faculty advisors were used to promote a sense of community. Quantitative retention and graduation rates for the cohort are compared to other engineering groups at the same institution. Qualitative results collected via student surveys and interviews, and lessons learned by project administrators are also presented. Retention and graduation rates of the cohort are better than those of comparable groups at the same institution. Graduation rates based upon freshman math placement are also higher than comparable groups.

Mathcad procedures, in the form of worksheets, are presented and discussed for problems associated with piping systems. Examples include series piping systems, parallel piping systems, and piping networks. The Mathcad solution approaches differ significantly from conventional techniques and are more congruent with problem formulations. The use of Mathcad permits the students to be more concerned with problem formulations and results interpretations than with arithmetic, programming, and debugging issues. © 2002 Wiley Periodicals, Inc. Comput Appl Eng Educ 10: 59–78, 2002; Published online in Wiley InterScience (www.interscience.wiley.com.); DOI 10.1002/cae.10010

Uncertainty analysis, which is frequently used in conjunction with experimentation, is adapted for use in thermal systems analysis and design. The basic concepts of uncertainty analysis are reviewed, and applications in thermal systems analysis and design are demonstrated for series piping systems, piping networks, and cross-flow heat exchangers. For piping systems and networks, the use of uncertainty analysis gives considerable understanding into the pump over-specification problem and results in a quantifiable alternative to the use of safety factors. The use of uncertainty analysis permits bounds to be placed on predicted performance parameters and yields insight into the fidelity of such predictions and the importance of various physical variables. Uncertainty analysis is shown to be a viable paradigm for energy system analysis and design.

The uncertainty analysis of a rocket motor thrust measurement and calibration system is presented. The thrust measurement system has 10 load cells with 5 in tension and 5 in compression, and the calibration system has 6 load cells. The elemental sources of load-cell random uncertainty considered are excitation voltage, amplifier stability and noise, and analog-to-digital conversion resolution. The elemental sources of load-cell systematic uncertainty (bias) considered are calibration, excitation voltage, nonlinearity, hysteresis, system alignment, and other mechanical sources such as friction. The calibration hierarchy and excitation systematic uncertainties are correlated since they have a common source. These correlation effects dominate the resulting thrust measurement uncertainties and form the focus of this study. The trust measurement uncertainty is up to three and a half times larger when correlation effects are considered relative to the case where correlation is neglected.

The view factors that are used in diffuse-gray radiation enclosure calculations are often computed by approximate numerical integrations. These approximately calculated view factors will usually not satisfy the important physical constraints of reciprocity and closure. In this article several view-factor rectification algorithms are reviewed. A Monte Carlo investigation is undertaken to study the propagation of view-factor uncertainties into the heat transfer results of the diffuse-gray enclosure calculations. It is found that the weighted least-squares algorithm is vastly superior to the other rectification schemes for the reduction of heat flux uncertainties resulting from uncertainties in view factors. In a sample problem, which has proven to be very sensitive to uncertainties in view factor, the heat transfer calculations with weighted least-squares rectified view factors are very good with an original view-factor matrix computed to only one-digit accuracy.

Uncertainty analysis methods, which are adapted from experimental techniques, are applied to diffuse-gray radiation enclosure problems. The propagation of uncertainties in view factors, emissivities, surface areas, and boundary conditions into the computed results is developed along with the required sensitivity analysis. Special considerations of view factor reciprocity and closure are discussed, and it is shown that strict enforcement of these constraints greatly reduces the sensitivity of the results to errors in view factors and surface areas. Illustrative examples are given. The uncertainty analysis gives strong insights into the practical fidelity of diffuse-gray enclosure computations. f, I i M N Nomenclature area of surface k vector of coefficients in equation (3) diagonal matrix of areas diagonal matrix with zeros for elements 1 to M diagonal matrix with ek for elements k = 1 to matrix of view factors matrix defined with equation (30) transpose of F element i j of F identity matrix vector of ones number of surfaces with specified heat flux total number of surfaces irradiation incident on surface k net heat flux on surface k radiosity leaving surface k vector of radiosities and ek for elements k = M + l to N M and zeros for elements M t1 to N ' Professor, member AIAA, * Assistant Professor, member AIAA Professor, Associate Fellow AIAA, Professor and Head, Copyiiglll 1993 by the American lilnliiule Of AcronauliCS and Astronaurics. 1°C. All rights rercrved. 1 r intermediate result vector temperature on surface k U,,) uncertainty in parameter (.) Greek 69, radiosity error vector t k U Stefan-Boltzmann constant emissivity on surface k

Diminishing fossil fuel resources, ever-increasing energy cost, and the mounting concerns for environmental emissions have precipitated worldwide research on alternative fuels. Present study demonstrates low-emission combustion of diesel, biodiesel and straight vegetable oil (VO) is a dual-fuel burner employing flow blurring (FB) injector concept for fuel atomization. Measurements of temperature and CO and NOx emissions are acquired at various axial and radial locations within the combustor. A custom-designed thermocouple probe and a helium product gas sampling probe are employed to obtain the measurements. Infra-red images to depict combustor wall temperatures and visual flame images to demonstrated clean combustion are also presented. Results show that the FB injector ensured fine atomization of all three fuels irrespective of significant differences in their kinematic viscosity and surface tension properties.

Stanton number and skin friction coefficient results are presented for zero pressure gradient incompressible turbulent boundary layer air flows over two rough surfacescomposed of 1.27 mm base diameter by 0.635 mm high truncated cones spaced in staggered arrays two ( L/d 0 = 2) and four diameters( L/d 0 = 4)

Stanton number measurements are presented for the turbulent boundary layer flow of air on rough-wall flat plates with both constant wall temperature and step wall temperature boundary conditions. Two rough surfaces were used—one roughened with hemispheres spaced four diameters apart and the other with hemispheres spaced two diameters apart. The data are compared with each other and with results from a smooth surface tested in the same experimental facility. It is found that, when plotted as the ratio of Stanton number to constant wall temperature Stanton number vs the ratio of unheated length to distance from the leading edge, the data from the smooth and rough surfaces scatter about a single curve. This gives a new kernel function that, when used in the superposition solution of the arbitrary wall temperature problem, yields good results for both smooth and rough surfaces.

In order to realize the full potential of unmanned vehicle technology in near space, a full understanding of the heat transfer phenomena in the rarefied environment of near space is necessary. In the current work, a two-dimensional model is employed with a commercial computational fluid dynamics (CFD) software package to investigate the heat transfer phenomena within a near space payload. Convection and radiation heat transfer within a square cavity are evaluated for various boundary conditions including velocity slip and temperature jump conditions.

With the simulation of engineering processes via numerical methods on the rise comes the need for a quantitative measure of the agreement between computational results and experimental measurements. The use of quantitative methods in the comparison of the results of numerical and experimental analyses supersedes the traditional qualitative approach. In the present paper, the importance of the role of modeling assumptions in a verification and validation effort is illustrated through a mesoscale combustor example. The various types of uncertainties encountered in the experimentation and numerical simulation are investigated. Through the investigation the initial modeling assumptions proved to be insufficient, producing a comparison error outside of the acceptable range. Thus, the modeling assumptions were sequentially revised, minimizing the comparison error and producing a successful verification and validation effort.

In the 1910 rural community where my father was growing up, his teachers did not train him to become the pilot and aviation pioneer he later became. Airplanes had barely been invented and few if any teachers probably had any idea what skills one might need to fly them. Their curriculum certainly didn't reflect the world shrinking changes that aviation was about to bring. Similarly, in the 1940 rural community where I was growing up, my teachers did not train me to become the pioneer in computing and education which I later became. Computers were virtually unheard of by teachers and they certainly had no idea what thinking skills would be necessary for designing software. And, once again, the curriculum didn't reflect the changes that computers were about to launch.

Energy for heating, cooling, lighting, mechanical power, and various chemical processes is a fundamental requirement for both daily life and economic development. The negative impact on the environment of current energy systems is increasingly alarming, especially the global warming consequences of burning fossil fuels. The future requires change through the development and adoption of new supply technologies, through a successful search for new, less resource-intensive paths of economic development, and through adoption of energy. Greater energy efficiency is key for shifting country development paths toward lower-carbon economic growth. Especially in developing countries and transition economies, vast potential for energy savings opportunities remain unrealized even though current financial returns are strong. Activities included specialized technical assistance, training, and applied research covering the four primary areas of country interest: (a) development of commercial banking windows for energy efficiency; (b) support for developing energy service companies (ESCOs); (c) guarantee funds for energy efficiency investment financing; and (d) equity funding for ESCOs or energy efficiency projects. One clear message from the experience of the three country Energy Efficiency Project is the importance of establishing and maintaining practical, operationally focused dialogue between the banking community and the energy efficiency practitioner community.

Microsoft Excel is a ubiquitous tool used frequently by practicing engineers. A recent survey of alumni from The University of Alabama’s Department of Mechanical Engineering regarding software tools revealed that 100% of the respondents used Microsoft Excel regularly on their jobs, while a low percentage used standard packages such as ANSYS or MATLAB, and that none used software tools which had been bundled with textbooks. The spreadsheet environment offers a great platform for computation and organization of engineering work, and the Visual Basic engine allows for great extensibility of Excel through the development of special functions and add-in modules. This paper reports on a proof-of-concept project to implement sustained emphasis on Microsoft Excel in the thermal mechanical curriculum at The University of Alabama. Specific add-in modules for use in thermodynamic analysis and heat transfer analysis have been developed and are continually being refined. These add-in modules have been utilized in a sequence of courses Thermo I, Heat Transfer, Thermo II, and Energy Systems Design. Features of the add-in modules are detailed in this report and feedback from students and teachers are given.Copyright © 2008 by ASME

With the simulation of engineering processes via numerical methods on the rise comes the need for a quantitative measure of the agreement between computational results and experimental measurements. The use of quantitative methods in the comparison of the results of numerical and experimental analyses supersedes the traditional qualitative approach. In the present paper, the importance of the role of modeling assumptions in a verification and validation effort is illustrated through a meso-scale combustor example. The various types of uncertainties encountered in the experimentation and numerical simulation are investigated. Through the investigation the initial modeling assumptions proved to be insufficient, producing a comparison error outside of the acceptable range. Thus, the modeling assumptions were sequentially revised, minimizing the comparison error and producing a successful verification and validation effort.Copyright © 2008 by ASME

Computational models for dynamic fluid flow simulation are needed to predict pressures, temperatures, flowrates, and other quantities in present and future testing at the Component Test Facility (CTF) at NASA's Stennis Space Center (SSC). The Rocket Engine Transient Simulation (ROCETS) package, and Boeing Computer Services' EASY5x are the two major components of the EASY/ROCETS dynamic fluid flow simulation package, which has been developed by Mississippi State University personnel for use at SSC. This paper presents the results of preliminary modeling of the CTF at SSC, and discusses and demonstrates the use of EASY/ROCETS to model various control system strategies for the high pressure hydrogen (HPH2) subsystem of the CTF.

Results are presented for contact stylus measurements of surface roughness on in-service turbine blades and vanes. Nearly 100 turbine components were assembled from four land-based turbine manufacturers. Both coated and uncoated, cooled and uncooled components were measured, with part sizes varying from 2 to 20 cm. Spanwise and chordwise two-dimensional roughness profiles were taken on both pressure and suction surfaces. Statistical computations were performed on each trace to determine centerline averaged roughness, rms roughness, and peak to-valley height. In addition, skewness and kurtosis were calculated; as well as the autocorrelation length and dominant harmonics in each trace. Extensive three-dimensional surface maps made of deposits, pitting, erosion, and coating spallation expose unique features for each roughness type. Significant spatial variations are evidenced and transitions from rough to smooth surface conditions are shown to be remarkably abrupt in some cases. Film cooling sites are shown to be particularly prone to surface degradation.

A new parameter, the tibial sesamoid‐second metatarsal distance, was established to determine whether the sesamoids move in relation to the foot in hallux abducto valgus surgery. The reliability of the tibial sesamoid‐second metatarsal distance was assessed and shown to be excellent. Seventy-five feet underwent surgical correction of hallux abducto valgus. Four radiographic parameters—the intermetatarsal angle, the hallux abductus angle, the tibial sesamoid position, and the tibial sesamoid‐second metatarsal distance—were measured before and after surgery. The hallux abductus angle, intermetatarsal angle, and tibial sesamoid position were all significantly reduced following surgery. The tibial sesamoid‐second metatarsal distance was not affected by hallux abducto valgus correction. Thus the correction in sesamoid position gained with hallux abducto valgus correction is a direct result of lateral translocation of the metatarsal head, with no contribution from change in position of the sesamoid apparatus relative to the foot. (J Am Podiatr Med Assoc 89(11/12): 551-559, 1999)

A report on the progress of porting the ROCETS (ROCket Engine Transient Simulator) into the EASY5x simulation environment is presented. Brief descriptions of each of the software systems, information regarding the actual port process, and examples comparing the results of the two systems are given. It is shown that EASY5x is a suitable environment for utilization of the ROCETS engineering modules, and that, for the example systems shown, EASY5x actually seems to give more accurate solutions than the straight ROCETS code.

The combined effects of freestream acceleration and surface roughness on heat transfer and fluid dynamics in the turbulent boundary layer were investigated experimentally. The experiments included a variety of flow conditions ranging from aerodynamically-smooth through transitionally-rough to fully-rough boundary layers with accelerations ranging from moderate to modestly strong. Two well-defined rough surfaces composed of 1.27 mm diameter hemispheres spaced 2 and 4 diameters apart, respectively, in staggered arrays on otherwise smooth surfaces were used as the test surfaces. The first 1.5 m of the test section had zero-pressure gradient followed by a 0.4 m accelerated region with the remaining 0.4 m adjusted to zero-pressure gradient. The Stanton number for the rough-wall experiments decreased or increased for accelerated rough-wall cases compared to zero-pressure gradient cases depending on flow conditions. For fully-rough boundary layers, Stanton numbers increased with acceleration compared to zero-pressure gradient at the same x-position. For aerodynamically-smooth and transitionally-rough boundary-layer flows, the effect of acceleration was not similar to that of fully-rough flows and was highly dependent upon the flow conditions. The acceleration caused a decrease in the relative turbulence level over the rough surface. The profiles of u′2¯ for the accelerated runs were lower than those of zero-pressure gradient cases, and a substantial decrease in the Reynolds shear stress (−u′v′¯) component was observed when acceleration was applied.

Measurements of Stanton numbers, velocity profiles, temperature profiles, and turbulence intensity profiles are reported for turbulent flat plate boundary layer flows with a step change in surface roughness. The first 0.9 m length of the test surface is roughened with 1.27 mm diameter hemispheres spaced 2 base diameters apart in a staggered array. The remaining 1.5 m length is smooth. The experiments show that the step change from a rough to a smooth surface has a dramatic effect on the convective heat transfer. In many cases, the Stanton number drops below the smooth-wall correlation immediately downstream of the change in roughness. The Stanton number measurements are compared with predictions using the discrete element method with excellent results.

This article discusses nine aspects of education which will be increasingly affected by integrating computing into educational activities to any significant degree. They involve the learner and instructor, the materials and content, the processes followed, and the overall societal perception of education.

In the field of data processing, the professional needs to keep abreast of new developments. For programmers and their supervisors, this involves learning about, evaluating, and subsequently using or rejecting new programming concepts. Whether one is charged with educating and training programmers or with hiring them, this need to keep abreast raises some interesting questions. This paper concerns itself with three such questions: 1. From what sources do programmers in the field learn about new concepts? 2. Is there a significant relationship between particular aspects of a programmer's background and his/her awareness of new programming concepts? 3. Is there a significant relationship between particular aspects of a programer's working environment and his awareness of new concepts?

Because of the rapid growth of computing and its influence in schools and community colleges, we find we must teach a growing number of graduate teachers and administrators how to program. Because we firmly believe that the only programming worth doing is well-structured programming, this is the sort of programming we want to teach these graduates to do. Because BASIC, FORTRAN, and COBOL are so widely implemented around the world, we know that one or more of these languages will be the ones most of our students will end up programming in, after they leave Columbia. Because such languages are not particularly well-suited for teaching structured programming to beginners, we decided to develop an indirect approach to this goal, one which would make the learning of these languages the learning of second languages in a second phase of learning to program. The approach which we have been developing, including the major components of a first programming language - FPL, is suggested in the remainder of this paper. For us, it has proven to be an indirect but effective way to teach raw beginners how to write well-structured programs in archaic, ill-designed, high-level real languages.

Instructional use of computers is now common at many secondary schools and in elementary schools. The computer is recognized as a new and important educational medium, as a source of change in existing curriculum, as a new curriculum area. Thus there is growing awareness that pre-service elementary and secondary school teachers need some computer education. What are colleges of education doing to meet this challenge? A panel of faculty from several colleges of education will present their views and insights. They will point out successes, both at their own schools and on a national scale. They will also point out what still remains to be done. There will be time for input from the audience.

Would a school system allow a person with only an eight-grade education to become an English teacher? Would a self-taught math teacher be given full responsibility for the high school math program? The answers to these questions are obvious to everyone: to become a subject-matter specialist school teacher, one must demonstrate competency by fulfilling state certification requirements.Yet these same school systems, which have well-defined qualification standards for English teachers and math teachers, today often assign full responsibility for the computer studies/computer science program to teachers who are self-taught or whose formal training is equivalent to an eight-grade education in the subject.

As the field of data processing grows, it becomes increasingly important for the computer professional to keep abreast of new developments. Because one of the most significant of these new developments is structured programming, we decided to use knowledge of structured programming concepts as a measure of how up-to-date a programmer is. Thus, we undertook to answer the following questions:1. How up-to-date are today's programmers, i.e. how aware are they of some of these new concepts?2. From what sources did they learn about these concepts? How much did these sources influence their work?3. What are some of the other factors which influence up-to-dateness?To find the answers, we prepared a survey of sixteen questions. The first fifteen questions were designed to provide us with a background profile of our polled population. The last question dealt specifically with structured programming, presenting a list of programming concepts and potential sources for learning about these concepts. The respondent was questioned about his familiarity with a particular concept, his source of learning about the concept, and the degree to which his work was influenced by this source. The responses were input to a program written in CROSSTABS, a commercially available utility package, to produce tables of cross-tabulations and frequency percentages. We analyzed these tables and our conclusions drawn from this analysis follow.

This paper reports empirical research supporting the intuition that visual representation can make at least some abstract concepts easier to comprehend. A study of novices’ comprehension of computer programs was conducted using two programming languages, FPL (a graphically represented language) and Pascal (a textually represented language). The study focused on whether some identifiable subset of learners performs more quickly and/or more accurately on comprehension tasks when reading program segments coded in the graphically represented language than when reading their equivalent in a textual language. The findings support the intuition that graphical representation results in more rapid and accurate comprehension than does textual representation. This bias is even more marked for the visually apt learner. The findings are of importance to educators at all levels, suggesting that, in the design of learning materials, the graphic capabilities of computing ought to be more fully exploited to meet the differing needs and learning profiles of students.

Results are presented from profilometer measurements of the surface roughness on inservice turbine engine blades from F-100 and TF-39 aeroengines. On each blade, one roughness profile is taken in the region of the leading edge, the mid-chord and the trailing edge on both the pressure and suction sides for a total of 6 profiles. Thirty 1st stage turbine blades are measured from each engine. Statistical computations are performed on these profiles and the root mean square height, skewness and kurtosis of the roughness height distribution are presented along with the correlation length of the autocorrelation function. The purpose of this work is to provide insight into the nature of surface roughness characteristics of inservice turbine blades which can be used in the development of scaled laboratory experiments of boundary layer flow and heat transfer on turbine engine blades.

A discrete element model for turbulent flow over rough surfaces has been rigorously derived from basic principles. This model includes surface roughness effects as a constituent part of the partial differential equations which describe momentum and energy transport in turbulent flows. The model includes the necessary empirical information on the interaction between the roughness elements and the flow around and between the elements in a general way which does not require experimental data on each specific surface. This empirical information is input via algebraic models for the local element drag coefficient and Nusselt number. These models have been calibrated by comparison with base data sets from surfaces with three-dimensional (distributed) roughness elements. Calculations using the present discrete element model are compared with experimental data from 118 separate experimental runs. The results of these comparisons range from good to excellent. The calculations are shown to compare equally well with both transitionally rough turbulent flow and fully rough turbulent flow without modification of the roughness model. In the course of the present work it was discovered that the definitive data set of Schlichting is flawed. Corrected values are presented for this data set.

THE clinical resemblance of the rare carcinoma of the meibomian gland to the relatively frequent chalazion should be kept in mind by anyone performing eyelid surgery. Straatsma, 1 in a critical review of the world literature, reported 97 proven case histories of carcinoma of the meibomian gland. Subramanian et al 2 reviewed the literature and noted 140 case reports. Boniuk and Zimmerman have more recently written on this subject pointing out that the presence of this tumor may be more common than previously suspected. 3 The following case report represents another example. Report of a Case A 38-year-old South Vietnamese man was first seen at the 91st Evacuation Hospital in December 1967, complaining of a large, cosmetically disfiguring lesion on the lateral border of the left upper eyelid. This growth had been present for approximately 1½ years. Examination revealed a 1 × 1.5-cm multinodular, hard, nontender lesion elevating the skin