Conference Session

Laboratory Innovations

Collection

2012 ASEE Annual Conference & Exposition

Authors

James Aflaki, Christian Brothers University

Tagged Divisions

Mechanical Engineering

a strain gage based scale called SqueezoMeter designed to measure theapplied squeezing or pushing force. It is made of an S-shaped sensing element equipped with 4-strain gages, and two rectangular aluminum plates to apply the force.The second experiment, HuggoMeter, consists of two parallel ¼ inch aluminum beams mountedon two 8.5 x 16 x 1 in hard boards that are 1.25 inches apart. Mounted on the constant bendingportion of these beams are 4 strain gages forming a 4-active arm Wheatstone bridge. Studentscan hug the HuggoMeter and apply forces to it. The induced strains are measured through a dinrail mounted signal conditioner and A/D module, converted to the applied force and displayed onthe PC screen.These experiments, while entertaining and

Conference Session

Active and Project-based Learning

Collection

2012 ASEE Annual Conference & Exposition

Authors

Joakim Sigurd Wren, Linköping University

Tagged Divisions

Mechanical Engineering

, its relevance in engineering and engineeringeducation cannot be underestimated, especially when having today´s energy andenvironmental concerns in mind.Despite the importance of the subject, it has been considered as “dry and abstract” bystudents 1. One reason might be that the subject has become more and more difficult to relateto its applications –the fundamentals principles are the same as for 150 years ago, but theapplications become more and more refined due to technological developments andinnovations. If so, it is altogether not surprising that students find engineeringthermodynamics abstract, being separated from its applications – this might be devastating forthe students’ interest and possibility to learn.An increase in student

Conference Session

Learning and Assessment II

Collection

2012 ASEE Annual Conference & Exposition

Authors

John W. Evangelista P.E., U.S. Military Academy

Tagged Divisions

Mechanical Engineering

suggest that the majority ofstudent learning in engineering courses (approximately two-thirds) actually occurs outside of theclassroom.1 In addition to this, as students enter their senior year, they ought to be expected andencouraged to develop disciplined professional habits for lifelong learning.A challenge to this sort or rhetoric however lies with recent trends in engineering enrollment.Studies suggest that students may be leaving engineering because the work load is too severe. Inaddition to curriculum difficulty and low grades, work load was a primary factor reported amonga survey of 120 engineering students across five institutions that decided to leave theirengineering major to pursue other studies.2 A more recent article from the New

Conference Session

Trends in Mechanical Engineering: Trends and Tools

Collection

2012 ASEE Annual Conference & Exposition

Authors

Aaron P. Wemhoff, Villanova University

Tagged Divisions

Mechanical Engineering

formulate foran academic setting. The confidence in the solution method for a student can be built byfollowing a worked-out example, matching the final answers with the answer key, or applyingmultiple approaches to tackling a problem. Lecture courses often use the first two approachesdue to the simplicity of problems and the availability of example problems in textbooks.However, in professional practice the problems have not been previously worked out andsolutions are not given. Therefore, the only means to gain confidence in a solution by aprofessional engineer is to apply multiple approaches to tackling a problem, and improvedreliability is achieved when the two different routes to a solution give similar results.Figure 1 shows the advantages and

Conference Session

Thermodynamics, Fluids, and Heat Transfer

Collection

2012 ASEE Annual Conference & Exposition

Authors

Kyle A. Watson, University of the Pacific; Ashland O. Brown, University of the Pacific; Rachelle Kisst Hackett, University of the Pacific; Alexis Pham, University of the Pacific

Tagged Divisions

Mechanical Engineering

has served as Dean for two engineering schools and headed groups at Ford Motor Co. and General Motors Corp., which included a product design section composed of product analysis engineers (finite element analysis experts). He has taught engineering courses in thermodynamics, solar engineering, graphics, dynamics, machine design, and finite elements methods. He has more than 50 referred technical research publications, and conference papers with 10 in the areas of finite element learning modules, with two recently accepted as referred engineering journal papers covering the results of the NSF CCLI-Phase 1 work.Dr. Rachelle Kisst Hackett, University of the Pacific Rachelle Kisst Hackett, Ph.D., is an Associate

Conference Session

Active and Project-based Learning

Collection

2012 ASEE Annual Conference & Exposition

Authors

Garrett Miles Clayton, Villanova University; Teresa Genevieve Wojcik, Villanova University; Aleksandra Radlińska, Villanova University; Noelle K. Comolli, Villanova University

Tagged Divisions

Mechanical Engineering

this paper, the use of impromptu design exercises in an introductory mechanical engineeringcourse is presented. These exercises are used to introduce three design concepts: 1) the designprocess (in general), 2) brainstorming and decision making, and 3) optimization. The developedexercises are presented along with details pertaining to implementation and preliminaryevaluation results.The impromptu design exercise format [1-3] is commonly used at engineering student functions,like conferences, as a fun, ice-breaker activity [1]. In a typical contest, students are given asimple design task capable of being completed in a short amount of time, a bag of (carefullychosen) supplies, and nothing else. The student team approaches the problem as they

Conference Session

Laboratory Innovations

Collection

2012 ASEE Annual Conference & Exposition

Authors

Claire Yu Yan, University of British Columbia; Carolyn Labun, University of British Columbia

Tagged Divisions

Mechanical Engineering

of the differentassignments and learning methods.Course Goals and Instructional MethodsKinematics and Dynamics of Machinery covers fundamental principles in analysing andsynthesising mechanisms and is a foundation to the broader subject of machine design. Theobjectives of this course are 1) to develop students‟ essential technical knowledge in machinery,2) to develop their ability to implement classroom learning through solving real-life designproblems, and 3) to encourage technical communication, problem-solving, critical thinking, andteamwork skills.In order to achieve these objectives, this course (in Term 1 of 2011-2012) was taught bycombining active learning elements, for example, real-life examples and design projects, withtraditional

Conference Session

Learning and Assessment III

Collection

2012 ASEE Annual Conference & Exposition

Authors

Horacio Vasquez, University of Texas, Pan American; Arturo A. Fuentes, University of Texas, Pan American; Robert A. Freeman, University of Texas, Pan American

Tagged Divisions

Mechanical Engineering

the instructor. At the end of theclass period, additional questions that require simple calculations are given to the students.Consequently, students getting C or better grades were 92.6% using such new approachcompared to 59.2% in a simultaneously taught traditional Statics course9. Being aware of theseinterventions in Statics courses at different institutions, this project presents a description ofonline formative assessments to integrate knowledge and recitation sessions developed for theStatics courses which are expected to enhance traditional face-to-face Statics instruction.Statics Course Difficulties and Opportunities Figure 1 indicates the main topics that are associated with student learning outcomes in theStatics course in the

Conference Session

Learning and Assessment I

Collection

2012 ASEE Annual Conference & Exposition

Authors

John K. Estell, Ohio Northern University; John-David S. Yoder, Ohio Northern University; Briana B. Morrison, Southern Polytechnic State University; Fong K. Mak, Gannon University

Tagged Divisions

Mechanical Engineering

ithas been adopted and modified by other programs and institutions, and recommendationsregarding its future use.1. Origins of the Faculty Course Assessment ReportIt is often said that necessity is the mother of invention; the Faculty Course Assessment Reportdocument was developed under such circumstances. During the 2001-2002 academic year, boththe computer engineering and electrical engineering programs housed within the Electrical &Computer Engineering and Computer Science (ECCS) Department at Ohio Northern University(ONU) were preparing for an ABET accreditation visit under the then-new “EC 2000” guidelines Page 25.755.2requiring programs

Conference Session

Laboratory Innovations

Collection

2012 ASEE Annual Conference & Exposition

Authors

Arif Sirinterlikci, Robert Morris University; Tony Lee Kerzmann, Robert Morris University

Tagged Divisions

Mechanical Engineering

their education1. In order to facilitate hands-on learning in the engineeringprograms at Robert Morris University, basic mechanisms have already become an integrated partof the introductory courses of ENGR 1010 - Introduction to Engineering and ENGR 2160 -Engineering Graphics. Freshman engineering students become familiar with the motion ofmechanical systems. The students have been asked to construct a crank mechanism, such as anoscillating lever with a connecting rod. Three of the many mechanisms that were constructed inthe Introduction to Engineering course are shown in Figure 1. Figure 1: Student built wooden mechanical systems

Conference Session

Thermodynamics, Fluids, and Heat Transfer

Collection

2012 ASEE Annual Conference & Exposition

Authors

Onursal Onen, University of South Florida; Rasim Guldiken, University of South Florida

Tagged Divisions

Mechanical Engineering

undereach heading listed is described below. The main emphasis was on introducing students the state-of-the-art technology of microfluidics and its applications. The lecture was taught towards theend of the semester. The lecture materials including the presentation are available for downloadin the webpage: http://me.eng.usf.edu/Faculty/guldiken/TUTORIALS.html.Introduction and ScalingThe introduction part started with the definitions, stating the need for microfluidics and typicalcomponents in a microfluidic system. The advantages (also disadvantages) of microfluidics werediscussed in detail, mainly resulting from the scaling down from macro scale to micro scale. Thedimension and volume scale were presented with illustrations (Figure 1) enabling

Conference Session

Trends in Mechanical Engineering: Curricula and Courses

Collection

2012 ASEE Annual Conference & Exposition

Authors

Lisa Abrams, Ohio State University; James William Altschuld, Ohio State University; Blaine W. Lilly, Ohio State University; Daniel A. Mendelsohn, Ohio State University

Tagged Divisions

Mechanical Engineering

. It isestimated that approximately 200 students per semester will take this new design course.Two pilots of the new design course will be completed before the semester implementation inFall 2012. Assessment instruments of the pilots include assignment rubrics, focus groups,surveys, and questionnaires. This paper includes some of the preliminary data collection andresults and issues encountered by the development team.IntroductionThe Ohio State University (OSU) is a Research 1 land grant institution. Mechanical Engineeringat OSU has historically had a traditional curriculum with a hands-on design experience in thefirst year, theoretical and laboratory experiences in the second and third year, and a seniorcapstone in the fourth year.The

Conference Session

Learning and Assessment III

Collection

2012 ASEE Annual Conference & Exposition

Authors

Tom Spendlove, Baker College, Flint; Anca L. Sala, Baker College, Flint; James Riddell, Baker College, Flint

Tagged Divisions

Mechanical Engineering

one project from a first or secondyear class and one from a third, fourth or fifth year class that demonstrates we are meeting theoutcome. This also fits in well with our learning centered instruction initiative at the college sowe can not only show the school what we’re doing but show them how it fits into the confines ofour accrediting body. Page 25.880.5The Program Educational Objectives are to prepare graduates who: 1. demonstrate competencein engineering practice in local and global industry environments, or in related careers ingovernment or academia. 2. exhibit effective communication, team work, and readiness forleadership while

Conference Session

Simulations and Visualizations

Collection

2012 ASEE Annual Conference & Exposition

Authors

Ricardo Medina, California State University, Los Angeles; Ashkan Motamedi, California State University, Los Angeles; Murat Okcay, Interactive Flow Studies Corporation; B. Uygar Oztekin, Interactive Flow Studies Corporation; Gustavo Borel Menezes, California State University, Los Angeles; Arturo J. Pacheco-Vega, California State University, Los Angeles

Tagged Divisions

Mechanical Engineering

sketch of its geometry is shown in Fig. 1,has been recently used in the FlowCOACH experimental setup as a ‘model insert’ to providestudents at CSULA supplemental information through visual appreciation of the flow in alaboratory setting[6]. In reference to Fig. 1, the channel geometry is comprised of three differentsections: (1) a diverging section with dimensions 27 mm and 80 mm at the end points, and alength of 90 mm in the streamwise-direction (x-direction), (2) a squared section, whichcorresponds to the model insert in the FlowCOACH device, with dimensions of 80 mm × 80mm, and (3) a converging section with dimensions: 80 mm and 42 mm at the end points and alength of 27 mm. The squared-obstruction of the model insert has dimensions of 20 mm

Conference Session

Outreach, Engagement, and Undergraduate Research

Collection

2012 ASEE Annual Conference & Exposition

Authors

Karinna M. Vernaza, Gannon University; Mahesh C. Aggarwal, Gannon University

Tagged Divisions

Mechanical Engineering

paper will describe the involvement of theundergraduate students in the organization and execution of the event, the activities proposed andselected, and the advantages of students’ active participation. Finally, the lessons learned andchallenges experienced will be discussed.1 IntroductionOutreach events have demonstrated to be an effective approach to promote engineering majorsamongst young generations at the same time that they support the mission of engineeringprofessional societies and universities. Literature presents a large number of examples of pre- Page 25.1017.2college (K-12) level outreach programs undertaken by universities

Conference Session

Learning and Assessment II

Collection

2012 ASEE Annual Conference & Exposition

Authors

Randy Dean Kelley P.E., University of Pittsburgh, Johnstown

Tagged Divisions

Mechanical Engineering

objective.1 The research datais taken in class with active participation from the students.The term “mini” research papers refers to research papers limited to five pages. Although short,each research paper must include the basics of a full paper: introduction, theory section,procedures, results, conclusions and references. The course used to develop this procedure wasundergraduate Heat Transfer. Three simple experiments were conducted during class and thedata taken was given to the entire class. The students were divided into small groups andallowed two weeks to write the report.Learning ObjectivesThere are three major learning objectives as well as some minor ones. The major objectives areas follows:  To further develop the engineering

Conference Session

Capstone Courses

Collection

2012 ASEE Annual Conference & Exposition

Authors

Martin Edin Grimheden, Royal Institute of Technology

Tagged Divisions

Mechanical Engineering

changed the way many software developersorganize their work and projects, for example as in Scrum by delegating responsibilities,empowering individuals and delaying decisions. The main driver in most methods is“accelerated delivery” realized by focusing on small steps, incremental development,prototyping and quick feedback rather than extensive planning and documentation [1].The “Agile Manifesto” [2] is based on twelve principles to follow as an agile softwaredeveloper: from “…satisfying the customer through early and continuous delivery…”,“…welcome changing requirements…”, “…business people and developers must worktogether…”, “…face-to-face conversation…”, “…self-organizing teams…” to “…the teamreflects on how to become more effective…” [2].The

Conference Session

Active and Project-based Learning

Collection

2012 ASEE Annual Conference & Exposition

Authors

Isaac M. Choutapalli, University of Texas, Pan American; Robert A. Freeman, University of Texas, Pan American; Young-Gil Park, University of Texas, Pan American

Tagged Divisions

Mechanical Engineering

not important enough to merit much attention to featureslike improved accuracy and precision. However, in complex measurements, when the stakesbecome greater, the selection of measurement equipment and techniques and the interpretation ofmeasured data can demand considerable attention. CBI for MECE 3320 teaches students theimportance of measurements in these complex situations. The technique helps students developan experimental test plan and use the measurement system so that the engineer can easilyinterpret the measured data and be confident in its meaning. The study by Pandy et al. [1] whichshowed that the CBI approach, as compared to a traditional approach, increased the students’conceptual knowledge and the ability to transfer the

Conference Session

Thermodynamics, Fluids, and Heat Transfer

Collection

2012 ASEE Annual Conference & Exposition

Authors

Govind Puttaiah P.E., West Virginia University; Timothy A. Drennen; Samuel C. Brunetti; Christopher M. Traylor

Tagged Divisions

Mechanical Engineering

25.346.2*Seniors (2010) in Mechanical Engineering, **Professor of Mechanical Engineering.Currently Tim Drennen* and Sam Brunetti* are with DuPont Company.1. Problem Statement The goal of the project (originally a senior design project) was to design, install,and test a hydrogen injection system that can be used on a commercial gasoline internalcombustion engine (ICE). The factory-installed gasoline injection system would stilloperate to control gasoline injection while a separate hydrogen injection system would beadded to control injection of hydrogen. A sensor would be used as feedback in the closedloop system to cut back on gasoline as hydrogen is injected. The original plan was not to build a complete hydrogen conversion system

Conference Session

Trends in Mechanical Engineering: Trends and Tools

Collection

2012 ASEE Annual Conference & Exposition

Authors

Timothy A. Doughty, University of Portland; Steven O'Halloran, University of Portland

Tagged Divisions

Mechanical Engineering

’ “Introduction toLabVIEW” Hands-On guide7, which provides a very general framework. The created tutorialassumes that the student has access to the equipment listed below:  Laptop computer running National Instruments LabVIEW 2009 Software  NI cDAQ-9172 (USB data acquisition chassis)  NI-9215 (analog voltage input module for DAQ)  Fluke thermocouple module with probe, model 80TK (Quantity: 2)The tutorial is broken down into five main sections which are listed below. Along the way areseveral exercises in which the students create LabVIEW programs to accomplish certain tasks.The exercises build on each other throughout the tutorial. 1. The LabVIEW Environment  Students test the data acquisition hardware, ensuring

Conference Session

Learning and Assessment III

Collection

2012 ASEE Annual Conference & Exposition

Authors

Craig W. Somerton, Michigan State University

Tagged Divisions

Mechanical Engineering

AC 2012-3489: DEMONSTRATING STUDENT OUTCOMES: EVIDENCEBY SAMPLINGDr. Craig W. Somerton, Michigan State University Page 25.384.1 c American Society for Engineering Education, 2012 Demonstrating Student Outcomes: Evidence by SamplingIntroductionCriterion 4 of the ABET Criteria For Accrediting Engineering Programs states, “The programmust regularly use appropriate, documented processes for assessing and evaluating the extent towhich both the program educational objectives and the student outcomes are being attained.” [1]A key aspect of this criterion is that the program must provide evidence demonstrating that thestudent

Conference Session

Simulations and Visualizations

Collection

2012 ASEE Annual Conference & Exposition

Authors

Nicholas Mark Randall, University of Southern Maine ; Mehrdaad Ghorashi P.E., University of Southern Maine

Tagged Divisions

Mechanical Engineering

statics course to explore the concept of equilibrium of a rigid body. In this way, mechanicalengineering students will gain an increased depth of understanding of the subject as well as someinsight about the application of the theories.2. Theoretical Analysis of Bending and Transverse LoadingIt is well-known that if a homogeneous, isotropic prismatic beam is subjected to a transversalshear force V, the resulting shear stress τ, induced in the beam can be obtained by10, (1) Page 25.395.3Where I is the cross-sectional moment of area, Q is the first moment of

Conference Session

Capstone Courses

Collection

2012 ASEE Annual Conference & Exposition

Authors

Raghu Echempati, Kettering University; Vipul Laddha, Kettering University; Sualp Ozel P.E., Autodesk, Inc.; James Herzing

Tagged Divisions

Mechanical Engineering

. Truck stands are used for both assembly and serviceoperations of railcars. Although not a very critical component, due to the large volume ofstands used by the rail industries, optimal design is justified to minimize the costs. Thestudy and structural analysis of a car-truck stand was carried out as a part of FEA coursestudied at Kettering University. Several textbooks on FEA are available in the literature,for example Logan [1], and Carroll [2]. Earlier work done by Fox and Echempati [3]consisted of performing design of experiments (DOE) to study the effect of changing thegeometry variables of the stand structural members on the overall strength of the stand. Aconventional design of the car stand is shown in Figure 1, which is made of

Conference Session

Trends in Mechanical Engineering: Curricula and Courses

Collection

2012 ASEE Annual Conference & Exposition

Authors

Simin Hall, Virginia Tech; Catherine T. Amelink, Virginia Tech; Deyu Hu, Virginia Tech

Tagged Divisions

Mechanical Engineering

, andpractices that have been validated for adult education by cognitive science and/or empiricaleducational research1, 2 & 3 and processes used by the distance learning institute at Virginia Techthat relies on a structured life cycle methodology for online course development. End of coursesurvey indicated that the online offering is welcomed by students.1. IntroductionThere is an increasing interest in nuclear power due to growing energy needs4 with the projectedincrease in electricity demand in the United States as well as the world5 in the recent years hasled to a nuclear renaissance. One of the challenges of this nuclear renaissance is the workforcecrisis. There is significant need for educating nuclear engineers who can engage in research

Conference Session

Trends in Mechanical Engineering: Curricula and Courses

Collection

2012 ASEE Annual Conference & Exposition

Authors

Benita M. Comeau, Massachusetts Institute of Technology; Rohit Karnik, Massachusetts Institute of Technology; Sang-Gook Kim, Massachusetts Institute of Technology

Tagged Divisions

Mechanical Engineering

Micro/Nano Engineering Laboratory CourseAbstractManufacturing and innovating at the micro/nano scale is a major trend in technologydevelopment. Whether in the traditional submicron manufacturing systems associated withelectronic devices or in emerging areas such as biotechnology and energy harvesting, micro/nanosystems are becoming increasingly important and prevalent.1-2 This paper describes howengineering at micro and nano length scales was brought to mechanical engineeringundergraduates through the Micro/Nano Engineering Laboratory (2.674/2.675) at theMassachusetts Institute of Technology (MIT). This class is a hands-on laboratory designed toinspire interest and excitement about engineering at the small scale through building, observingand

Conference Session

Trends in Mechanical Engineering: Trends and Tools

Collection

2012 ASEE Annual Conference & Exposition

Authors

Vincent Capece, University of Kentucky

Tagged Divisions

Mechanical Engineering

formal report template similar tothe paper formats currently provided by many professional societies to further supplement thewriting guide. Nevertheless, many students still had difficulty with the first few writingassignments. Thus, a two week technical writing component (writing workshop) was added tothe junior level experimentation course in spring 2010; the refresher lectures are still used for thesecond experimentation course.Writing Workshop AgendaDuring the writing workshop there was approximately eight contact hours with the junior levelmechanical engineering students. Table 1 presents an outline of the workshop. As displayed inTable 1, the workshop consists of lectures on grammar and technical report writing (figures,tables

Conference Session

Simulations and Visualizations

Collection

2012 ASEE Annual Conference & Exposition

Authors

Claudio Luiz Curotto, Federal University of Parana, Brazil; Kurt C. Gramoll, University of Oklahoma

Tagged Divisions

Mechanical Engineering

, that includes, as much as possible, topics ofthe course content. A project includes a computational experiment where students can see how adynamics problem works by modifying various parameters and then obtaining the correspondinggraphical and numerical results. Their main task is to develop the theoretical basis of the projectcomparing their numerical results with those produced by the experiment. The assessment ispersonal and done by an exam where the student must answer questions about his or her project.Three basic premises will give the directions of that implementation, described to follows:1. A student must be able to access an experiment in any device, a computer, a smartphone, atablet, etc., by using only a web browser without any

Conference Session

Thermodynamics, Fluids, and Heat Transfer

Collection

2012 ASEE Annual Conference & Exposition

Authors

David Zietlow, Bradley University; Jacqueline Henderson, Bradley University

Tagged Divisions

Mechanical Engineering

law of thermodynamics. This installation allows the visitor to stand on a platform to simulate an earthquake causing damage to a building. As this happens, a graphical representation demonstrates the level of disorder or entropy as a fan levitates ping-pong balls. The amount of disorder is decreased when the building is reconstructed. Another product of this collaboration was a 99 second video explaining entropy. The video can be used as a pedagogical tool across all disciplines to initiate discussion topics such as ethics and global issues facing society. Additionally, entropy can be a portal into some questions about deeper issues such as: 1) what is the cause of disorder, 2) do we live in an isolated system, and 3) how can

Conference Session

Learning and Assessment III

Collection

2012 ASEE Annual Conference & Exposition

Authors

Jenna L. Gorlewicz, Vanderbilt University; Robert James Webster III, Vanderbilt University

Tagged Divisions

Mechanical Engineering

options: (1) at the beginning of a lab session,(2) after a pre-lab lecture, (3) immediately after completion of the lab, and (4) after completion ofthe lab report. This assessment architecture enables us to determine whether learning happened inlecture, in the lab itself, or during subsequent reflection on laboratory results during the process ofwriting the lab report. 1 Introduction A common challenge in engineering education is to develop students’ intuitive understandingof how physical systems behave, despite the fact that many students have never physically observedor interacted with the systems they are learning about. A variety of approaches have previouslybeen developed to address this, including implementation of hands-on

Conference Session

Capstone Courses

Collection

2012 ASEE Annual Conference & Exposition

Authors

Blair T. Allison, Grove City College; Stephen Ludwick, Aerotech, Inc., and University of Pittsburgh; William P. Birmingham, Grove City College

Tagged Divisions

Mechanical Engineering

support, and input during design reviews.IntroductionGrove City College (GCC) routinely participates in the SAE Mini Baja competition and theASME Human Powered Vehicle Challenge. Frames for these vehicles are typically fabricatedfrom sections of thin-walled steel tubing that are TIG welded together (see Figures 1 and 2).Tube ends must be notched prior to welding to insure proper fit-up and to maintain small gaps inthe joint area. Figure 3 shows a typical joint – in this case a 90° intersection of tubes of the samediameter. While more complicated joints with three or more tubes intersecting at a singlelocation are occasionally required1, the most common joint involves only two tubes intersectingat a specified angle. A common method for tube