Conference Session

Design in Engineering Education Poster Session

Collection

2006 Annual Conference & Exposition

Authors

Krisztian Dancs, University of North Florida; Vanja Gadzic, University of North Florida; Tyler Dao, University of North Florida; Truong Nguyen, University of North Florida; Chiu Choi, University of North Florida

Tagged Divisions

Design in Engineering Education

, digital system design, electromagnetics, signals and systems, circuit analysis, and others. His research interests include microcontroller-based system design, computational algorithms for controls, and control theory. Dr. Choi is a registered Professional Engineer (Florida). Page 11.139.1© American Society for Engineering Education, 2006 A Vehicle Drivable by a Laptop PCAbstractThis paper describes the details of converting a regular vehicle into a vehicle that is drivable by alaptop PC. The work was done as a design project in the first controls course in our curriculum.The students applied

Conference Session

Sustainable Engineering

Collection

2006 Annual Conference & Exposition

Authors

Deanna Matthews, Carnegie Mellon University; Robert Heard, Carnegie Mellon University

Tagged Divisions

Environmental Engineering

2006-954: GREENING OF EDUCATION: ECOLOGICAL EDUCATION INENGINEERINGDeanna Matthews, Carnegie Mellon University Deanna H. Matthews is Research Associate in both Civil and Environmental Engineering and the Eberly Center for Teaching Excellence at Carnegie Mellon University. As a researcher in the Green Design Institute, her research focuses on environmental performance of firms, life cycle assessment of products and services, and advancing environmental literacy in higher education and in informal settings. At the Eberly Center, she assists in programs for graduate students and in research related to project course development and working with students on group projects. She received her BSE

Conference Session

Emerging Trends in Engineering Education Poster Session

Collection

2006 Annual Conference & Exposition

Authors

Paul Rodriguez, Cedaredge Middle School; Catherine Skokan, Colorado School of Mines

showngreat progress and has been named a 2005 Gain-Maker School by the state for being the mostimproved middle school in the area of mathematics. The average scale score gains on the stateassessment in mathematics were 35.7 over the time period from 2002 – 2004. Teachers fromthe middle school have participated in two workshops (including academic year followup) of theuniversity that emphasized engineering applications for the mathematics and science classrooms.Also, two engineering senior design teams from CSM have worked on projects in curriculum andclassroom material development for the middle school. These programs have been coupled witha focused effort on the part of the teachers to improve specific mathematics and science skillsthroughout each

Conference Session

Teaching Strategies in Graphics

Collection

2006 Annual Conference & Exposition

Authors

Yi-hsiang Chang, Purdue University; Craig Miller, Purdue University

Tagged Divisions

Engineering Design Graphics

design rationality, general information of the students, selections of themes, exercisedesign, different forms of assessments and their outcomes. This article is concluded with possiblefuture improvements.Course backgroundProduct Lifecycle Management (PLM) is the latest IT innovation floating around in today’smanufacturing industry. Purdue University has been engaging in PLM-related activities since1999. Through the strategic partnerships and collaborative projects with industry and softwarevendors, Purdue University has built a strong reputation in the PLM area during the past six years.While many industries are interested in PLM, Purdue University has learned from our industrycontacts that there is currently a great shortage of PLM-literate

Conference Session

Elementary School Engineering Education

Collection

2006 Annual Conference & Exposition

Authors

Sean Doherty, Worcester Polytechnic Institute; Shweta Shanbhag, Worcester Polytechnic Institute; Martha Cyr, Worcester Polytechnic Institute

Tagged Divisions

K-12 & Pre-College Engineering

teachers in this area. Anattempt to address this demand led to the introduction of the Pre-College Engineering forTeachers (PCET) program by Tufts University with a grant from the National ScienceFoundation [2]. The primary goals of this program are to familiarize the participating teacherswith the engineering design process, to introduce them to an assortment of projects to enhancelearning and to incorporate engineering principles in their curriculum. Starting in 2002, thisprogram has already been implemented at the high school and middle school levels and is now inprogress at the elementary school level. Table 1 shows the progression of the programimplementation and the grade levels of participating teachers.ImplementationHow it works: Each

Conference Session

Teaching Innovation in Architectural Engineering I

Collection

2006 Annual Conference & Exposition

Authors

Suzanne Bilbeisi, Oklahoma State University

Tagged Divisions

Architectural

issue at hand. These case study presentations are organized into a three part series:Architectural Graphic Communication, Fundamental Design Principles, and DesignProcesses. The Architectural Graphic Communication series consists of three sessions: DrawingTypes and Rendering, Orthographic Projection, and Linear Perspective. The FundamentalDesign Principles series also consists of three sessions: Form, Space and Order, Visual Devices,and Formal Penetrations. The Design Process Series consists of four sessions: ArchitecturalDesign, Architectural Engineering Design, Design and Construction, and the Interview of aProfessional. A description of the topic and associated case study, which utilize contemporary aswell as historical designers for their

Conference Session

Software Engineering Teaching Methods and Practice

Collection

2006 Annual Conference & Exposition

Authors

Martin Zhao, Mercer University; Laurie White, Mercer University

Tagged Divisions

Software Engineering Constituent Committee

orietation) and the cutting-edge technologies. Not enough effort seems tohave been made to show how the models and principles discussed in the texts can be applied toreal world projects.A team-based software project is commonly included in a contemporary software engineering Page 11.542.2class to give students hands-on experience of the issues that they may encounter in a real-world 1development environment. It is commonly accepted that the best strategy is to guide the studentsto learn software engineering by really doing it. 3, 12 Some new textbooks 4, 3 devote moredetailed coverage on latest OOAD

Conference Session

New Horizons in Academic Integrity

Collection

2006 Annual Conference & Exposition

Authors

Murali Krishnamurthi, Northern Illinois University; Jason Rhode, Northern Illinois University

Tagged Divisions

Engineering Ethics

2006-1104: PROMOTING ACADEMIC INTEGRITY THROUGH AN ONLINEMODULEMurali Krishnamurthi, Northern Illinois University MURALI KRISHNAMURTHI is Associate Professor of Industrial and Systems Engineering and Director of Faculty Development and Instructional Design Center at Northern Illinois University. His teaching and research interests include information systems, project management, optimization, simulation, and engineering ethics.Jason Rhode, Northern Illinois University JASON RHODE is the Online Technologies Coordinator at the Faculty Development and Instructional Design Center at Northern Illinois University. He has a master's degree in Curriculum and Instruction, and is currently a Ph.D

Conference Session

Entrepreneurship Education - A 10,000' View

Collection

2006 Annual Conference & Exposition

Authors

Wade Shaw, Florida Tech; Muzaffar Shaikh, Florida Tech; Carmo D'Cruz, Florida Tech

Tagged Divisions

Entrepreneurship & Engineering Innovation

’ educational experience, broadened their perspectives, served as community outreachforums and integrated experiential learning with academic programs. Students work in E-teamsand write NCIIA proposals to commercialize innovative product or university/research labdeveloped technology.This paper describes a unique course series in Systems Engineering (SE) Entrepreneurship.Innovation in product/service design and commercialization that enables entrepreneurship can besuccessfully leveraged by applying SE principles/ techniques which parallel entrepreneurshipsteps such as Customer Requirements Engineering and opportunity recognition; Project/QualityEngineering, Decision/Risk Analysis, Systems Modeling, Engineering Economics and businessplanning, Systems

Conference Session

Examining the Synergy between Eng'g Mgmt & Sys Eng

Collection

2006 Annual Conference & Exposition

Authors

Wade Shaw, Florida Tech; Muzaffar Shaikh, Florida Tech; Carmo D'Cruz, Florida Tech

Tagged Divisions

Engineering Management

Engineering Systems at Florida Tech have greatly enriched thestudents’ educational experience, broadened their perspectives, served as community outreachforums and integrated experiential learning with academic programs. Students work in E-teamsand write NCIIA proposals to commercialize innovative product or university/research labdeveloped technology.This paper describes a unique course series in Systems Engineering (SE) Entrepreneurship.Innovation in product/service design and commercialization that enables entrepreneurship can besuccessfully leveraged by applying SE principles/ techniques which parallel entrepreneurshipsteps such as Customer Requirements Engineering and opportunity recognition; Project/QualityEngineering, Decision/Risk Analysis

Conference Session

Standards Based Approaches to K -12 Engineering

Collection

2006 Annual Conference & Exposition

Authors

Sara Titus, University of Maryland-Baltimore County; John Raczek, University of Maryland-College Park; Bruce Jarrell, University of Maryland School of Medicine; Carolyn Parker, George Washington University; Taryn Bayles, University of Maryland-Baltimore County; Julia Ross, University of Maryland-Baltimore County

Tagged Divisions

K-12 & Pre-College Engineering

in the area of cellular engineering. In particular, her work focuses on bacterial adhesion to physiological surfaces. In addition, she maintains an active research program in curriculum development with a focus on workforce development. Page 11.1463.1© American Society for Engineering Education, 2006 “ENGINEERING IN HEALTH CARE” MULTIMEDIA CURRICULUM FOR HIGH SCHOOL TECHNOLOGY EDUCATIONIntroduction This instructional materials development project, funded by the National Science Foundation,seeks to provide new curricula that incorporate hands-on experiences and inquiry-based learning with‘real world

Conference Session

Materials Science and Engineering of 2020

Collection

2006 Annual Conference & Exposition

Authors

Linda Vanasupa, California Polytechnic State University; Blair London, California Polytechnic State University; Katherine Chen, California Polytechnic State University; Richard Savage, California Polytechnic State University

Tagged Divisions

Materials

practices”. Our preliminaryresults are promising: within one year, we were able to reverse a five-year trend in decliningenrollment; we have just finished our fourth consecutive year of 100% on-time completions ofsenior projects; students exhibit a shift in mindset towards a greater awareness of theirprofessional responsibility to serve humanity. In this paper, we will provide a survey of thetechniques that we have used along with some preliminary results from our program.INTRODUCTIONGlobalization, the information age and prosperity have come together in the late 20th century tocreate a host of challenges that threaten the survival of the planet and its inhabitants. The dangersigns are everywhere: ubiquitous toxins that damage the animal and human

Conference Session

NEW Lab Experiments in Materials Science

Collection

2006 Annual Conference & Exposition

Authors

Valerie Maynard, Northwestern University; Matthew Hsu, Northwestern University; Katherine Chen, California Polytechnic State University; R.P.H. Chang, Northwestern University

Tagged Divisions

Materials

educational materials for grades7 – 16. Learning theory and cutting-edge research are used in the development of modules onnanoscience and nanotechnology. This paper describes the rationale for such materials anddescribes an introductory module in which students are lead through a series of inquiry-basedand hands-on activities, which lead to a design project. Its goal is to teach an underlyingprinciple in nanoscience and nanotechnology—the significance of the surface-area-to-volumeratio as objects get very small. The first section of the module investigates how the physical formof a material can influence the degree to which an object interacts with its environment. Differentforms of different materials (steel, superabsorbent polymer, and sugar) are

Conference Session

Design for Community and Environment

Collection

2006 Annual Conference & Exposition

Authors

Serdar Tumkor, Istanbul Technical University; Karl Haapala, Michigan Technological University; Vishesh Kumar, Michigan Technological University; John Sutherland, Michigan Technological University

Tagged Divisions

Design in Engineering Education

necessary to create innovative products with acceptable lifecycle costs and environmental impact during and after the product use. To address this needprojects are assigned to students in senior-level course MAK422E Engineering Design atIstanbul Technical University Mechanical Engineering Dept. In this course, the projects areprepared as teams of 7 to 8 students with an objective to redesign a product to reduce itsenvironmental impact, while maintaining functionality and costs. To accomplish this goal,several DfE (Design for Environment) approaches (e.g., design for disassembly, design forreuse/remanufacturing, design for recycling, design for energy efficiency, design for minimummaterial usage, and design for minimum hazardous material) are

Conference Session

Emerging Trends in Engineering Education Poster Session

Collection

2006 Annual Conference & Exposition

Authors

Elliot Diaz, Polytechnic University of Puerto Rico; Carlos Pacheco, Polytechnic University of Puerto Rico; Carlos Rosaly, Polytechnic University of Puerto Rico; Michael Figueroa, Polytechnic University of Puerto Rico; Eddalis Batista, Polytechnic University of Puerto Rico; Othoniel Rodriguez-Jimenez, Polytechnic University of Puerto Rico

2006-1487: REDUCING THE DEVELOPMENT COSTS FOR ACTIVE ANDINTERACTIVE LEARNING OBJECTS THROUGH WEB-BASEDCOLLABORATIVE AUTHORINGElliot Diaz, Polytechnic University of Puerto Rico Elliot Diaz Research Assistant within the eLearning Research Laboratory at the Polytechnic University of Puerto Rico, where he is pursuing a Master in Computer Engineering. Elliot holds a BS in Computer Science.Carlos Pacheco, Polytechnic University of Puerto Rico Carlos Pacheco is a programmer with the Connect To Learn Project which is developing web-based authoring for the collaborative authoring of learning objects. He completed a BS in Computer Engineering summa cum laude at the Polytechnic University of Puerto

Conference Session

Effective & Efficient Teaching Skills

Collection

2006 Annual Conference & Exposition

Authors

Eric Larson, Seattle University; Agnieszka Miguel, Seattle University

Tagged Divisions

New Engineering Educators

options. Projects, commonly used in upper-level electivesand senior design courses, permit students to explore a particular topic in great depth. Grading aproject may involve reviewing deliverables such as proposals, design documents, posters,presentations, and final reports. Since team work is an important part of projects, assessmentmay also include factors such as individual effort, team communication, and projectmanagement.In compiling the list of tips presented in this paper, we not only relied on our experience as newfaculty members but also received advice from more experienced faculty. We interviewedseveral faculty members from different disciplines of engineering and computer science on howthey graded various course activities. Our first

Conference Session

Forum on Collaborative Information Literacy Programs

Collection

2006 Annual Conference & Exposition

Authors

Honora Nerz, North Carolina State University; Lisa Bullard, North Carolina State University

Tagged Divisions

Engineering Libraries

technology and the ability to retrieve information arethe same skill sets. In fact, they are not.”10 Students’ inflated sense of confidence can evencajole faculty (especially those who aren’t as comfortable with information technologies) intobelieving that they are already experts in this arena. Page 11.1309.4Changing Expectations Historically, the acquisition of information skills has been something that was on theperiphery of the curriculum – for example, a paper or other research project might be assigned inclass, but when it came to actually doing the associated research, students would often beexpected to figure it out on their own. As

Conference Session

Environmental Engineering Curricula

Collection

2006 Annual Conference & Exposition

Authors

Michelle Jarvie, Michigan Technological University

Tagged Divisions

Environmental Engineering

students to develop the interpersonalcommunication and team building skills required for success in the engineeringwork place5. In the professional engineering world, communication skills arerequired in the three forms of written, oral, and graphic communication6.This article focuses on the restructuring of a class from the traditional “bankingeducation” approach, to include elements of a more progressive active learningapproach. Collaborative formal discussion groups and research projects providedactive learning experiences, which included written, oral, and graphiccommunication.2. History of Class format:CE4506 Environmental Regulation and Pollution Prevention design has beentaught for several years at Michigan Technological University. From

Conference Session

Sustainable Engineering

Collection

2006 Annual Conference & Exposition

Authors

Sarah Pumphrey, University of Cincinnati; Anna Hoessle, University of Cincinnati; Daniel Oerther, University of Cincinnati

Tagged Divisions

Environmental Engineering

the efficacy of removing Polio LVS, Pseudomonas aeruginosa, Clostridium perfringes,and Naegleria fowleri as a model virus, gram negative bacteria, gram positive bacteria, andprotozoa, respectively. Removal efficiencies for these microorganisms in saline buffer are beingcompared to measurements of removal efficiency for culturable fecal coliform bacteria in rawOhio River water and saline buffer dosed with Escherichia coli.Context for the Engineering Design and Build ProjectTo provide a field-based, service learning component to this research project, the MS studentsteamed with the Village Life Outreach Program (VLOP) headquartered in Cincinnati, OH. TheVLOP is a group of professionals including medical personnel who volunteer time, talent

Conference Session

BME Curriculum Development

Collection

2006 Annual Conference & Exposition

Authors

Ann Saterbak, Rice University; Michele Follen, M.D. Anderson Cancer Center; Rebecca Richards-Kortum, Rice University

Tagged Divisions

Biomedical

included exposure to clinicalmedicine and the relevant vocabulary, research experiences that emphasize the creation andapplication of new scientific knowledge, and entrepreneurial experience and its attendantvocabulary. The ten-week summer course also emphasizes development of skills in leadership,communication, ethics, and team building.The typical day for the internship students begins with ninety minutes of lectures and exercisesabout ethics, communication skills, entrepreneurship, and leadership. Students attend a full-dayhuman cadaver-based anatomy course for the first two weeks of the course. Lectures, dissection,and special projects comprise this course of instruction in the anatomy, physiology, andpathophysiology of the major organ systems

Conference Session

Capstone Design and Entrepreneurship

Collection

2006 Annual Conference & Exposition

Authors

Thomas Miller, North Carolina State University; Stephen Walsh, North Carolina State University

Tagged Divisions

Entrepreneurship & Engineering Innovation

comprised of undergraduates and run these teams asvirtual start-up companies. Underclassmen serve as virtual employees of these E-Teams andparticipate for either 1-credit or 3-credits.Topics covered in the EEP include leadership, management, project planning, marketing, sales,operations, organizational behavior, financials, corporate formation, business planning, andintellectual property. The EEP Portal provides the students a structured, yet flexible, mechanismto manage their teams and the product development process. In addition, the EEP Portal allowsfaculty to observe the E-Team’s progress in real-time and to monitor the program’s pedagogicaleffectiveness.This paper discusses the impetus in developing the EEP Portal, its actual design

Conference Session

NSF Grantees Poster Session

Collection

2006 Annual Conference & Exposition

Authors

Sharlene Katz, California State University-Northridge; Kathleen Alfano, College of the Canyons

Tagged Divisions

Division Experimentation & Lab-Oriented Studies

toaddress the needs of industry by producing, as a multi-county consortium, highly skilled andeducated technicians to better meet national and State workforce demands in the fields ofinformation and manufacturing technologies.CREATE was previously funded by two NSF-ATE projects, which met or exceeded all of theirobjectives. The project had four primary goals, which included curriculum development,enrollment and retention, work-based site experiences and professional development. TheCREATE consortium developed programs that began with a common core curriculum in eitherengineering technology or computer networking. The common core curriculum allowed studentsto transfer from a participating college to any college in the consortium to take classes in

Conference Session

Examining the Synergy between Eng'g Mgmt & Sys Eng

Collection

2006 Annual Conference & Exposition

Authors

Timothy Trainor, U.S. Military Academy; Heidi Hoyle, U.S. Military Academy

Tagged Divisions

Engineering Management

practice.These outcomes provide the focus for the EM curriculum. The EM program model (Figure 1) offers a mix of engineering management, systemsengineering, an engineering discipline of cadet choice, finance and organizational managementcourses. Methods courses provide the EM major the basic tools and techniques for thediscipline. Cadets choose a specific engineering discipline (civil, mechanical, electrical,environmental or nuclear engineering) in which to develop a foundation in engineeringprinciples. Project courses build on some of the methods courses and provide cadets specificapplications useful for engineering managers. The organization, finance and management topicsgive cadets the multi-disciplinary exposure an engineering manager needs

Conference Session

International Engineering Education I

Collection

2006 Annual Conference & Exposition

Authors

Ashok Goel, Michigan Technological University; Hyun-Chan Cho, Korea University of Technology and Education

Tagged Divisions

International

March, 1998 Establishment of HRDI September, Completion of Educational Hall A and Guesthouse 1998 January, 1999 Completion of Educational Hall BDescription of the VLSI Design CourseAt present, the CMOS technology is the most widely used technology for the fabrication ofsilicon-based VLSI circuits and systems. The principal purpose of this course was to familiarizethe participants with the various aspects of the silicon CMOS technology and offer them anopportunity to actually design CMOS logic gates and circuits on a personal computer using thecomputer-aided design tool called L-Edit developed by the Tanner Research Corporation. Thiscourse consisted of a series of lectures, hands-on design projects

Conference Session

Emerging Trends in Engineering Education Poster Session

Collection

2006 Annual Conference & Exposition

Authors

Jerry Hamann, University of Wyoming; Linda Hutchison, Bristol Community College; Alan Moore, University of Wyoming

employment and advancement will go tothose prepared to deal confidently with quantitative, scientific, and technological issues. TheU.S. Bureau of Labor Statistics has projected a 15.2% increase from 2000-2010 in the need foremployees trained in engineering and other technical specialties1. However, the U.S.Department of Education's National Center for Educational Statistics has predicted a decrease inthe number of high school graduates in Wyoming, and this decrease is also expected to occur inmany of the Rocky Mountain and Midwestern states2. The declining number of college-agestudents, coupled with a declining interest in science and engineering careers, has seriousimplications for the U.S. economy and international competitiveness3. The picture

Conference Session

CPD - Engineering Education K - Life

Collection

2006 Annual Conference & Exposition

Authors

Kurt Becker, Utah State University

Tagged Divisions

Continuing Professional Development

2006-2371: SUPPORTING K-12 TEACHER PROFESSIONAL DEVELOPMENTTHROUGH THE NATIONAL CENTER FOR ENGINEERING ANDTECHNOLOGY EDUCATIONKurt Becker, Utah State University Kurt H. Becker, Ph.D is Interim Department Head in the Department of Engineering and Technology Education, College of Engineering at Utah State University. Areas of research include adult learning cognition, engineering education professional development and technical training. He is the co-project director for the NSF funded "National Center for Engineering and Technology Education" and the PI for the NSF funded "Communities of Effective Practice: A Professional STEM Development Model for Teachers of American Indian Students". He also

Conference Session

Elementary School Engineering Education

Collection

2006 Annual Conference & Exposition

Authors

Tuba Bayraktar, Hampton University; Keith Williamson, East Carolina University; Ilhan Bayraktar, Old Dominion University

Tagged Divisions

K-12 & Pre-College Engineering

Tufts University. He is the Principal Investigator on the GK12 project and has received numerous awards for teaching and research. Dr. Williamson’s current research is focused on University/K12 partnerships and thermo-mechanical processing.Ilhan Bayraktar, Old Dominion University Dr. Ilhan Bayraktar is a Research Scientist at Old Dominion University. He has a doctorate degree in Aerospace Engineering, and he works on wide range of engineering/education related projects. Page 11.351.1© American Society for Engineering Education, 2006 Connecting Elementary School Students to Energy

Conference Session

Emerging Trends in Engineering Education Poster Session

Collection

2006 Annual Conference & Exposition

Authors

Carlotta Berry, Tennessee State University

andnodal analysis, Thevenin’s and Norton’s theorems, first-order and second-order circuits andoperational amplifiers.The circuits course cooperative learning teams were required to work together the entiresemester to solve in-class concept questions and circuit analysis problems. The teams were alsorequired to meet outside of class for a minimum of one hour per week to study for quizzes andexams and to complete their homework. Additionally, the teams were required to complete threecomputer projects during the semester. In order to monitor student performance and progress, allteams were required to submit a team charter, meeting minutes and peer evaluations. The teamsall received a lecture on the Tuckman stages of team formation and the five

Conference Session

Preparing Engineers for the Global Workplace

Collection

2006 Annual Conference & Exposition

Authors

Gayle Elliott, University of Cincinnati; Cheryl Cates, University of Cincinnati; Brian Dansberry, University of Cincinnati; Louis Trent, University of Cincinnati

Tagged Divisions

International

and work in abroad. This combination of work experience and language proficiency hasproven valuable to students and employers. The students enter an international workenvironment feeling confident of their technical abilities. They become employee who can workindependently and take responsibility for their own projects. The language proficiency andcultural understanding enables them to quickly assimilate themselves into a new culture, andbecome productive members of work teams.The most recent addition to the program is the creation of two learning modules, which studentsare expected to complete during their international assignments. The learning modules aredesigned to make students aware of how their newly-acquired language skills enabled

Conference Session

Contemporary Instrumentation

Collection

2006 Annual Conference & Exposition

Authors

Seyed Allameh, Northern Kentucky University; Morteza Sadat-Hossieny, Northern Kentucky University; Paul Cooper, Northern Kentucky University

Tagged Divisions

Instrumentation

build bio-mimicked layered composites. Labview™ virtualinstruments (VIs) were developed to guide the robots, to actuate injectors, and to analyzeimages. The implications of this work for the projects assigned at the undergraduate levelas well as students’ capstone project will also be discussed.IntroductionIn the aftermath of the major disasters that claimed human lives and caused extensivefinancial losses, it is necessary to develop materials that resistant to powerful forces ofnature. Most buildings, especially in the third world countries are built from manuallylaid clay bricks (unfired or fired) in layered structures with mud or gypsum mortarinterlayers. In the event of an earthquake or other disasters that exert dynamic shearforces on