Solving Concurrent and Nonconcurrent Coplanar Force Systems: Balancing Theory and Practice in the Technology and Engineering Education Classroom

The basic concepts inherent to statics, including unbalanced and balanced forces and instability and stability of physical systems, have traditionally been covered in middle and high school physical science courses (Physical Science as indicated in Next Generation Science Standards). Yet, these concepts are covered using a physical science approach that has minor but significant differences in terminology, structure, and focus when compared with an engineering approach. Since a robust understanding of statics is considered an essential component for most engineering disciplines, Technology and Engineering Education’s (T&EE) implementation of statics with an engineering approach could promote students’ ability to transfer learning from scientific theory into conceptualized practical application within an engineering design problem. During the utilitarian period of our discipline (i.e., Manual Training [Arts] and Industrial Arts), scientific theories were applied to practical static problems like tree stands, dirt-bike stands, can crushers, wall brackets for hanging objects, scissor lifts, log splitters, dumb trailers, furniture, and other similar projects and mechanisms. Moving away from a more utilitarian rationale and towards an academic one, Technology Education and now T&EE needs to find the balance between theoretical and practical learning. The intention of this article is to provide the reader with a better understanding of an engineering approach to statics involving the terminology, structure, and focus aligned with applying theory to practical hands-on learning activities

Concrete Beam Design: Pouring the Foundation to Engineering in T&E Classrooms

Ask a middle or high school student if they could design a concrete beam that weighs only 20 pounds and is 36” long but must hold 600 pounds without failing. What is the student likely to say? What if the student was told that, with some optimized decision making based on relatively straightforward mathematics, their beam could hold 2400 pounds or more? The focus of this article is not on concrete beam design, it is rather an introduction to engineering principles in beam design using a lab activity. The concepts and skills learned in this article will lead students into concrete beam and form design and fabrication as well as the ability to precisely predict the amount of weight a concrete beam will hold during testing. An integral process of producing a concrete beam with a precisely predicted load causing failure is the emphasis of this and a subsequent article through a technical, hands-on activity involving the application of math, science, and engineering principles in the design, fabrication, and testing

Transforming Technology & Engineering Educator Inputs Into Desired Student Outputs Through Mechanism Analysis and Synthesis

The intention of this article is to provide middle and high school Technology and Engineering Educators (T&EEs) with a more thorough understanding of an engineering approach to the teaching and learning of mechanics. During the teaching and learning of engineering content, in this case mechanics, the educator should attempt to align pedagogical content knowledge with engineering content knowledge and practices. T&EEs will also need to focus on terminology, structure, and applying theory to practical hands-on learning activities inside and outside of the classroom. T&EEs have the potential to foster middle and high school students’ mechanical knowledge and the ability to apply this knowledge during engineering design experiences. As a robust understanding of mechanics is considered a requirement in college-level engineering programs, especially mechanical engineering, T&EEs should consider the development of students’ engineering knowledge and ability to apply this knowledge paramount. T&EEs are always looking for new standards-based content focused on improving students’ STEM-based skills and hands-on capabilities

Method of Joints: Theory and Practice of Designing, Building, and Testing Trusses

The authors of this article, like many of us, are proponents of engineering education but are also proponents of shop skills, craftsmanship, technological literacy, and the tacit knowledge and skills developed through applying sound theories during practical hands-on learning. The authors believe that engineering is an important aspect of our discipline, but so are the application of thinking, tool skills, measurement, geometric construction, manufacturing, instrumentation, testing and analysis, mathematical and scientific theories, and many other hands-on, minds-on skillsets that all need to maintain association with our discipline. As the authors are proponents for engineering education that is done well, they have provided an explanation of truss design using the Method of Joints that combines the application of practical hands-on learning with sound mathematical and scientific theory. The Method of Joints is a static principle stating that all joints in a truss must be in equilibrium. This means that forces on truss members of each joint must combine at the joint to equal zero for all joints. The Method of Joints will allow students to design trusses to meet specified criteria using mathematical models. The process of designing a truss to meet specific requirements involves students applying the Method of Joints to create and apply computational models. In the activity students will be able to design and predict the amount of weight causing truss failure, then test their truss to validate their predictions’ accuracy. If students minimize possible errors by building their trusses exactly as designed and calculated, most trusses will fail within 5% of the calculated amount. In two previous articles, component force systems were covered to help with the understanding of forces systems involved in truss design and the Method of Sections was also presented as another method for solving for forces in a truss (Huges & Merrill, ITEEA 2020, pp. 16-22). For a more thorough understanding of truss design, it is recommended that the reader review these two previous articles

Mechanism Design and Analysis: Developing an Understanding of Mechanism Motion Through Graphical Modeling

The intention of this article is to provide Technology and Engineering Educators with foundational knowledge of mechanism design and analysis and the ability to develop middle and high school students\u27 mechanism knowledge during practical hands-on learning activities in the STEM classroom. Technology and Engineering Educators\u27 implementation of mechanism design and analysis could promote students\u27 increased depth of mechanical knowledge and ability to apply this knowledge during engineering design challenges. In this article, the authors present an introduction to four-bar mechanism design and analysis using CAD software to produce graphical representations. After designing mechanisms graphical, students should be allowed to produce their mechanisms using tools like 3D printers

Analyzing Concrete Beam Design: Verifying Predictions in T&EE Classrooms

Design is often accepted as a fundamental aspect of engineering (Dym, et al., 2005). The design process is frequently portrayed as a set of steps. However, the design process is more complex than just a set of steps in a relatively fixed process. The complex nature of design, design thinking, questioning, and decision-making is exactly what technology and engineering classrooms are well suited to address. When addressing the question—“Why is technology and engineering education (T&EE) so important?”—the authors believe T&EE’s importance relates to our discipline’s ability to solve complex problems by balancing theory and practice in engaging hands-on learning scenarios like designing, fabricating, and testing a concrete beam

The sub-millimeter properties of broad absorption line quasars

We have carried out the first systematic survey of the sub-millimeter properties of broad absorption line (BAL) quasars. 30 BAL quasars drawn from a homogeneously selected sample from the Sloan Digital Sky Survey at redshifts 2<z<2.6 were observed with the SCUBA array at the JCMT to a typical rms sensitivity of 2.5 mJy. Eight quasars were detected at > 2 sigma significance, four of which are at > 3 sigma significance. The far-infrared luminosities of these quasars are > 10^{13} L_solar. There is no correlation of sub-millimeter flux with either the strength of the broad absorption feature or with absolute magnitude in our sample. We compare the sub-millimeter flux distribution of the BAL quasar sample with that of a sample of quasars which do not show BAL features in their optical spectra and find that the two are indistinguishable. BAL quasars do not have higher sub-millimeter luminosities than non-BAL quasars. These findings are consistent with the hypothesis that all quasars would contain a BAL if viewed along a certain line-of-sight. The data are inconsistent with a model in which the BAL phenomenon indicates a special evolutionary stage which co-incides with a large dust mass in the host galaxy and a high sub-millimeter luminosity. Our work provides constraints on alternative evolutionary explanations of BAL quasars.Comment: 8 pages, 2 figures, ApJ, in pres

Age and Grip Strength Predict Hand Dexterity in Adults.

In the scientific literature, there is much evidence of a relationship between age and dexterity, where increased age is related to slower, less nimble and less smooth, less coordinated and less controlled performances. While some suggest that the relationship is a direct consequence of reduced muscle strength associated to increased age, there is a lack of research that has systematically investigated the relationships between age, strength and hand dexterity. Therefore, the aim of this study was to examine the associations between age, grip strength and dexterity. 107 adults (range 18-93 years) completed a series of hand dexterity tasks (i.e. steadiness, line tracking, aiming, and tapping) and a test of maximal grip strength. We performed three phases of analyses. Firstly, we evaluated the simple relationships between pairs of variables; replicating the existing literature; and found significant relationships of increased age and reduced strength; increased age and reduced dexterity, and; reduced strength and reduced dexterity. Secondly, we used standard Multiple Regression (MR) models to determine which of the age and strength factors accounted for the greater variance in dexterity. The results showed that both age and strength made significant contributions to the data variance, but that age explained more of the variance in steadiness and line tracking dexterity, whereas strength explained more of the variance in aiming and tapping dexterity. In a third phase of analysis, we used MR analyses to show an interaction between age and strength on steadiness hand dexterity. Simple Slopes posthoc analyses showed that the interaction was explained by the middle to older aged adults showing a relationship between reduced strength and reduced hand steadiness, whereas younger aged adults showed no relationship between strength and steadiness hand dexterity. The results are discussed in terms of how age and grip strength predict different types of hand dexterity in adults