Smoke generator

Generator is simple in construction, efficient, and extremely easy to start and regulate. It can be of such small size and weight that it can be installed easily inside a model. Size can be changed to suit needs, as long as operating temperatures can be attained and identified controls are utilized

Cognitive barriers during monitoring-based commissioning of buildings

Monitoring-based commissioning (MBCx) is a continuous building energy management process used to optimize energy performance in buildings. Although monitoring-based commissioning (MBCx) can reduce energy waste by up to 20%, many buildings still underperform due to issues such as unnoticed system faults and inefficient operational procedures. While there are technical barriers that impede the MBCx process, such as data quality, the focuses of this paper are the non-technical, behavioral and organizational, barriers that contribute to issues initiating and implementing MBCx. In particular, this paper discusses cognitive biases, which can lead to suboptimal outcomes in energy efficiency decisions, resulting in missed opportunities for energy savings. This paper provides evidence of cognitive biases in decisions during the MBCx process using qualitative data from over 40 public and private sector organizations. The results describe barriers resulting from cognitive biases, listed in descending order of occurrence, including: risk aversion, social norms, choice overload, status quo bias, information overload, professional bias, and temporal discounting. Building practitioners can use these results to better understand potential cognitive biases, in turn allowing them to establish best practices and make more informed decisions. Researchers can use these results to empirically test specific decision interventions and facilitate more energy efficient decisions

Applications of Nonlinear Control Using the State-Dependent Riccati Equation

This thesis examines the relatively new theory of nonlinear control using state dependent coefficient factorizations to mimic linear state space systems. The control theory is a nonlinear quadratic approach, analogous to linear quadratic regulation. All implementations examined in this thesis are done strictly numerically. This thesis is meant to provide a proof of concept for both satellite control and for an artificial pancreas to regulate blood glucose levels in diabetics by automatic insulin injection. These simulations represent only a first step towards practical use of the NQR method, and do not address noise rejection or robustness issues

On positioning, deafness, and educational research: an autoethnography on deafness and qualitative research

Combining autoethnography and disability studies in education, this article is an autoethnographic study of the different ways the author was positioned as abled and disabled by her institution’s review board when reviewing her qualitative research proposal. The author talks back to the prevailing understandings of disability and conceptions of research that emerged as she interacted with the review board. Through the article, the author problematizes the ableism that surfaced and seeks to redefine what it means to be a qualitative researcher in spite of and because of her deafness. She ends by arguing for a more inclusive understanding of what it means to be a researcher and a call for review boards to broaden their understandings of research methodologies for those who do not identify as able-bodied

Molly and the Mathematical Mysteries: Ten Interactive Adventures in Mathematical Wonderland

Global Perspectives on STE

What is fundamental for the maintenance of excellence in scientific periodicals?

I am honored to contribute to this centenary edition of what will mark a landmark in the publication of medical science for the Revista de Medicina from the University of Sao Paulo Medical School. In response to the question, “What is fundamental for the maintenance of excellence in scientific periodicals?”, as an author, clinician scientist, and the Editor in Chief of the American Journal of Ophthalmology, my answer has remained the same. The criteria for meaningful scientific contributions in clinical medicine are threefold. [...

Hydrodynamic equations for self-propelled particles: microscopic derivation and stability analysis

Considering a gas of self-propelled particles with binary interactions, we derive the hydrodynamic equations governing the density and velocity fields from the microscopic dynamics, in the framework of the associated Boltzmann equation. Explicit expressions for the transport coefficients are given, as a function of the microscopic parameters of the model. We show that the homogeneous state with zero hydrodynamic velocity is unstable above a critical density (which depends on the microscopic parameters), signaling the onset of a collective motion. Comparison with numerical simulations on a standard model of self-propelled particles shows that the phase diagram we obtain is robust, in the sense that it depends only slightly on the precise definition of the model. While the homogeneous flow is found to be stable far from the transition line, it becomes unstable with respect to finite-wavelength perturbations close to the transition, implying a non trivial spatio-temporal structure for the resulting flow. We find solitary wave solutions of the hydrodynamic equations, quite similar to the stripes reported in direct numerical simulations of self-propelled particles.Comment: 33 pages, 11 figures, submitted to J. Phys.

Continuum limit of self-driven particles with orientation interaction

We consider the discrete Couzin-Vicsek algorithm (CVA), which describes the interactions of individuals among animal societies such as fish schools. In this article, we propose a kinetic (mean-field) version of the CVA model and provide its formal macroscopic limit. The final macroscopic model involves a conservation equation for the density of the individuals and a non conservative equation for the director of the mean velocity and is proved to be hyperbolic. The derivation is based on the introduction of a non-conventional concept of a collisional invariant of a collision operator

Structure of ADAFs in a general large-Scale B-field: The role of wind and thermal conduction

We have explored the structure of hot flow bathed in a general large-scale magnetic field. The importance of outflow and thermal conduction on the self-similar structure of a hot accretion flows has been investigated. We consider the additional magnetic parameters $\beta_{r,\varphi,z}\big[= c^2_{r,\varphi,z}/(2 c^2_{s}) \big]$, where $c^2_{r,\varphi,z}$ are the Alfv$\acute{e}$n sound speeds in three direction of cylindrical coordinate. In comparison to the accretion disk without winds, our results show that the radial and rotational velocities of the disk become faster however it become cooler because of the angular momentum and energy flux which are taking away by the winds. but thermal conduction opposes the effect of winds not only decrease the rotational velocity but also increase the radial velocity as well as the sound speed of the disk. In addition we study the effect of global magnetic field on the structure of the disk. Our numerical results show that all components of magnetic field can be important and they have a considerable effect on velocities and vertical structure of the disk.Comment: accepted for publication in Research in Astronomy and Astrophysic