scholarly journals Familiarize Your Students with Life at the Microscopic Scale

2021 ◽  
Vol 83 (9) ◽  
pp. 607-610
Author(s):  
Robert A. Cooper

Developing students’ understanding of cells and the microscopic scale is an important goal of biology education. Cells are the building blocks of multicellular organisms, and most of Earth’s biodiversity is found at the microscopic scale. Developing an understanding of the microscopic scale requires that students use their quantitative reasoning skills. Here, resources are presented that help students develop their quantitative reasoning skills and improve their understanding of the small scale of microscopic life. The crosscutting concept, Scale, Proportion, and Quantity, and the science and engineering practice, Using Mathematics and Computational Thinking, are highlighted. The development of students’ quantitative reasoning skills in biology is universally recognized as an important outcome of biology education.

Author(s):  
Roger G. Harrison ◽  
Paul W. Todd ◽  
Scott R. Rudge ◽  
Demetri P. Petrides

Designed for undergraduates, graduate students, and industry practitioners, Bioseparations Science and Engineering fills a critical need in the field of bioseparations. Current, comprehensive, and concise, it covers bioseparations unit operations in unprecedented depth. In each of the chapters, the authors use a consistent method of explaining unit operations, starting with a qualitative description noting the significance and general application of the unit operation. They then illustrate the scientific application of the operation, develop the required mathematical theory, and finally, describe the applications of the theory in engineering practice, with an emphasis on design and scaleup. Unique to this text is a chapter dedicated to bioseparations process design and economics, in which a process simular, SuperPro Designer® is used to analyze and evaluate the production of three important biological products. New to this second edition are updated discussions of moment analysis, computer simulation, membrane chromatography, and evaporation, among others, as well as revised problem sets. Unique features include basic information about bioproducts and engineering analysis and a chapter with bioseparations laboratory exercises. Bioseparations Science and Engineering is ideal for students and professionals working in or studying bioseparations, and is the premier text in the field.


Author(s):  
LARRY LEIFER ◽  
SHERI SHEPPARD

The intellectual content and social activity of engineering product development are a constant source of surprise, excitement, and challenge for engineers. When our students experience product-based-learning (PBL), they experience this excitement (Brereton et al., 1995). They also have fun and perform beyond the limits required for simple grades. We, their teachers, experience these things too. Why, then, are so few students and faculty getting the PBL message? How, then, can we put the excitement back in engineering education? In part, we think this is because of three persistent mistakes in engineering education:1. We focus on individual students.2. We focus on engineering analysis versus communication between engineers.3. We fail to integrate thinking skills in engineering science and engineering practice.


Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 118
Author(s):  
Jean-Laurent Pouchairet ◽  
Carole Rossi

For the past two decades, many research groups have investigated new methods for reducing the size and cost of safe and arm-fire systems, while also improving their safety and reliability, through batch processing. Simultaneously, micro- and nanotechnology advancements regarding nanothermite materials have enabled the production of a key technological building block: pyrotechnical microsystems (pyroMEMS). This building block simply consists of microscale electric initiators with a thin thermite layer as the ignition charge. This microscale to millimeter-scale addressable pyroMEMS enables the integration of intelligence into centimeter-scale pyrotechnical systems. To illustrate this technological evolution, we hereby present the development of a smart infrared (IR) electronically controllable flare consisting of three distinct components: (1) a controllable pyrotechnical ejection block comprising three independently addressable small-scale propellers, all integrated into a one-piece molded and interconnected device, (2) a terminal function block comprising a structured IR pyrotechnical loaf coupled with a microinitiation stage integrating low-energy addressable pyroMEMS, and (3) a connected, autonomous, STANAG 4187 compliant, electronic sensor arming and firing block.


Author(s):  
Alice M. Agogino

How will engineering practice change in the next twenty years? What are the implications to engineering education? Will we have achieved gender equity? These questions will be discussed in the context of three recent reports of the US. National Academy of Engineering – The Engineer of 2020: Global Visions of Engineering in the New Century; Educating the Engineer of 2020: Adapting Engineering Education to the New Century; and Beyond Bias and Barriers: Fulfilling the Potential of Women in Academic Science and Engineering.


1930 ◽  
Vol 34 (235) ◽  
pp. 559-576 ◽  
Author(s):  
R. McKinnon Wood

Much has been learnt, in many branches of science and engineering, from the use of small scale models. The earliest successful experiments in humanly contrived flight with heavier-than-air craft, were made with small scale prototypes of the man-carrying machine of a later day : experiments with man-carrying craft, kite, glider and power-driven, followed.


Author(s):  
Lorenzo Cappietti ◽  
Irene Simonetti ◽  
Ilaria Crema

Abstract The use of Very Large Floating Structures, VLFS, may represent a strategic approach in order to cope with some of the future societal challenges arising from the impressive growth of the world population. In this article, the motivations of this perspective are briefly discussed, the main issues for the development of VLFS are summarized and a concept structural design based on building-blocks technology is proposed. A small-scale physical model was manufactured and tested in the wave-current flume of the Laboratory of Maritime Engineering, LABIMA, of the Florence University, Italy. The aim of this study is the assessment of the structural feasibility and the effectiveness of the proposed VLFS concept, in terms of resistance to wave loads and control of floating behavior. The experimental measurements provide a first contribution to the necessary knowledge, about load magnitudes and floating behavior, for sizing some of the key structural components. The results appear to support the feasibility of the system in terms of usage of structural materials, technical components and building technologies, available at present, that can withstand the measured loads. Moreover, the acquired experimental database is fundamental in order to validate numerical models, in the perspective of using also such tools as complementary methodology for further improvement of the knowledge of design issues.


2019 ◽  
Vol 489 (2) ◽  
pp. 1667-1683 ◽  
Author(s):  
Essam Heggy ◽  
Elizabeth M Palmer ◽  
Alain Hérique ◽  
Wlodek Kofman ◽  
M Ramy El-Maarry

ABSTRACT Radar observations provide crucial insights into the formation and dynamical evolution of comets. This ability is constrained by our knowledge of the dielectric and textural properties of these small-bodies. Using several observations by Rosetta as well as results from the Earth-based Arecibo radio telescope, we provide an updated and comprehensive dielectric and roughness description of Comet 67P/CG, which can provide new constraints on the radar properties of other nuclei. Furthermore, contrary to previous assumptions of cometary surfaces being dielectrically homogeneous and smooth, we find that cometary surfaces are dielectrically heterogeneous ( εr′≈1.6–3.2), and are rough at X- and S-band frequencies, which are widely used in characterization of small-bodies. We also investigate the lack of signal broadening in CONSERT observations through the comet head. Our results suggest that primordial building blocks in the subsurface are either absent, smaller than the radar wavelength, or have a weak dielectric contrast (Δ εr′). To constrain this ambiguity, we use optical albedo measurements by the OSIRIS camera of the freshly exposed subsurface after the Aswan cliff collapse. We find that the hypothetical subsurface blocks should have |Δ εr′|≳0.15, setting an upper limit of ∼ 1 m on the size of 67P/CG's primordial building blocks if they exist. Our analysis is consistent with a purely thermal origin for the ∼ 3 m surface bumps on pit walls and cliff-faces, hypothesized to be high-centred polygons formed from fracturing of the sintered shallow ice-bearing subsurface due to seasonal thermal expansion and contraction. Potential changes in 67P/CG's radar reflectivity at these at X- and S-bands can be associated with large-scale structural changes of the nucleus rather than small-scale textural ones. Monitoring changes in 67P/CG's radar properties during repeated close-approaches via Earth-based observations can constrain the dynamical evolution of its cometary nucleus.


Author(s):  
Piotr Bednarz ◽  
Jaroslaw Szwedowicz

In general engineering practice, crack tip opening displacement (CTOD) is very convenient approach for prediction of the components fracture mechanics (FM) lifetime. FM lifetime calculations are defined very well in industry and the lifetime prediction methods based on the CTOD resolve linear and nonlinear material behavior for monotonic and cyclic responses. The experiments confirm that under plasticity conditions the crack tip blunts for small scale or large scale yielding while, crack flanks open against each other only under elastic conditions. However, the CTOD application requires a very fine mesh in order to predict a crack tip deformation in reliable manner. Therefore, much more engineering work have to be involved in fine FE modeling. The crack tip flank deformation is crucial parameter responsible for reliable prediction of the nonlinear energy release rate, which is obtained from Hutchinson-Rice-Rosengren solution and the Shih rule. In accordance with design guidelines, the nonlinear energy release rate obtained from the CTOD must be evaluated conservatively to meet demands of RAM (Reliability, Availability and Maintainability). By using far crack deformation field, the paper proposes an engineering approach, which predicts the CTOD in a conservative manner under elastic-plastic conditions. This novel method is validated numerically by applying the well-known J-integral approach.


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