Microscale physical processes

Underlying all continuum and mesoscale descriptions of shock-wave compression of solids is the microscale. Physical processes on the microscale control observed dynamic material behavior in subtle ways sometimes in ways that do not fit nicely with simple preconceived macroscale ideas. The repeated cycle of experiment and theory slowly reveals the micromechanical nature of the shock-compression process. 

Decho A, Fleeger J (1988) Microscale dispersion of meio-benthic copepods in response to food-resource patchiness. J Exp Mar Biol Ecol 118 229-243 Dekshenieks MM, Donaghay PL, Sullivan JM, Rines JEB, Osborn TR, Twardowski MS (2001) Temporal and spatial occurrence of thin phytoplankton layers in relation to physical processes. Mar Ecol Prog Ser 223 61-71... 

Many of the macroscale and mesoscale P2 approaches rely on a molecular-level understanding of chemical and physical process at the microscale. For example, the synthesis of new catalysts to achieve higher yields with less wastes relies on a fundamental understanding of surface chemistry. There are a large number of methods available for undertaking P2 at the microscale via the molecular-level redesign of chemical products and processes. In line with the emergence... 

Different particulate processes will behave very differently, and, in each case, a microscale physical scenario must be hypothesized in order to formulate the mesoscale model. For more details on these and other examples, readers are referred to the work of Lee et al. (1962), Marchisio Barresi (2009), and Zucca et al. (2006). 

Many physical processes do not scale uniformly in the microscale domain i.e. ... 

Microscale process engineering involves the integration of various microscale chemical and physical processes (unit operations) with considerations of fluid... 

Several advances on microscale devices and systems have taken place in the past few decades. These devices have taken advantage of low cost and superior performance for the augmentation in transport processes because of their small scale. However, there is a limited understanding of physical processes in these devices. More experimental and simulation studies are essential for further improvement and development of these microsystems. Therefore, I decided to pursue research on the emerging field of microfluidics and heat transfer. My first interest was to extend my prior expertise on experimental techniques for macroscale systems to microsystems. While initiating research on this topic, I also proposed an optional course at DT Kanpur to expose the students to this new exciting research area. I searched for a textbook on this topic but could not find a single book that satisfies all the requirements of my course proposal. Therefore, I had to refer to many reference books for the preparation of my class notes. This book is the result of several revisions of my class notes. 

Tissues consist of smaller repeating units on the scale of hundreds of micrometers in vivo. The 3D architecture of these repeating tissue units underlies the coordination of multicellular processes, emergent mechanical properties, and integration with other organ systems via the microcirculation [11], Furthermore, the local cellular environment presents biochemical, cellular, and physical stimuli that orchestrate cellular fate processes such as proliferation, differentiation, migration, and apoptosis. Thus, successful fabrication of a fully functional tissue must include both an appropriate environment for cell viability and function at the microscale... 

With an understanding of the structure and properties of engineering materials now firmly in place, we can discuss how these materials can be formed or fabricated into useful products and components. Most of the important processing methods are described here, with little or no distinction made between microscale and macroscale processes—for example, processes that form both integrated circuits and components for highway bridges are described here. The common thread is that all the chemical and physical phenomena needed to introduce these processing techniques have already been described in the previous chapters. 

The macroscale behaviour of high specific surface particulate minerals is directly related to microscale interparticle electrical forces, thus, the physical interpretation of electromagnetic wave parameters allows inferring important properties about these materials. Furthermore, the properties of high specific surface particulate materials are environmentally dependent, hence, they are difficult to determine without altering them in the measurement process. In... 

In all of the above cases, a strong non-linear coupling exists between reaction and transport at micro- and mesoscales, and the reactor performance at the macroscale. As a result, the physics at small scales influences the reactor and hence the process performance significantly. As stated in the introduction, such small-scale effects could be quantified by numerically solving the full CDR equation from the macro down to the microscale. However, the solution of the CDR equation from the reactor (macro) scale down to the local diffusional (micro) scale using CFD is prohibitive in terms of numerical effort, and impractical for the purpose of reactor control and optimization. Our focus here is how to obtain accurate low-dimensional models of these multi-scale systems in terms of average (and measurable) variables. 

There are three chapters in this volume, two of which address the microscale. Ploehn and Russel address the Interactions Between Colloidal Particles and Soluble Polymers, which is motivated by advances in statistical mechanics and scaling theories, as well as by the importance of numerous polymeric flocculants, dispersants, surfactants, and thickeners. How do polymers thicken ketchup Adler, Nadim, and Brenner address Rheological Models of Suspensions, a closely related subject through fluid mechanics, statistical physics, and continuum theory. Their work is also inspired by industrial processes such as paint, pulp and paper, and concrete and by natural systems such as blood flow and the transportation of sediment in oceans and rivers. Why did doctors in the Middle Ages induce bleeding in their patients in order to thin their blood ... 

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