Gained in Translation: The Sudden Pivot Taking Physics Labs to the Cloud as a Reform Opportunity

I will report on a positive experience with using the forced transition to online learning as an opportunity to adopt one of many best-practice examples from the world of Physics Education Research. Following the example in Developing scientific decision making by structuring and supporting student agency by N.G. Holmes, et al [1], (and the instructional materials shared on Physport.org), my efforts were directed toward cueing students to make decisions to design their research question during our online meetings, rather than developing materials to micro-manage their behaviors. Characteristics of the new online medium influenced instructional design and accessibility in surprising ways. The centrality of group scientific presentation to their peers prompted responses such as for the first time, I actually cared what the answer was.” Students participated in a belonging intervention,” and what was once their least-favorite class became a refuge of supportive relationships during a difficult time. How can we make that the new normal for physics lab? \\ N.G. Holmes, Benjamin Keep, and Carl E. Wieman, Phys. Rev. Phys. Educ. Res. 16, 010109 (2020

The Physics of Human Performance: An IDEAL Lab

Physics lab goes to the gymnasium, where students calculate the mechanical power required to walk on an inclined treadmill in watts and convert to units power used to measure human performance: VO2, and METs. Students learn how to use two linear regression models: the ACSM walking equation to estimate the actual power expenditure of walking and the Rockport 1 mile test to estimate their own VO2max. Students use models to prescribe exercise parameters for themselves and for two cases. The IDEAL lab collaboration is developing labs that are open, applied to life, and rigorously quantitative

Maybe I Could Use this Again! Two IDEAL Labs Introducing Instrumentation

Physics lab students are introduced to custom instrumentation using Arduino-like microcontrollers which have allowed us to implement two labs of particular utility for life-science majors. Constructing a fluid circuit using the sponge-resistor model, flow sensors and an LCD display show the current through each section of pipe. The instrument can simultaneously measure and record 18 voltages, which enables us to record high-frequency “snap shots” of a signal generated on an RC-circuit model of an axon. The IDEAL lab collaboration is developing labs that are open, applied to life, and rigorously quantitative

Quantifying Measurement Error in Digital Instruments

A first lab experiment clearly illustrates that a glucose meter is actually an excellent source of both random and systematic error, much to the surprise to students and physicians alike. A histogram is constructed and the utility of the standard deviation and standard error to quantify the uncertainty in each measurement and in the mean value, respectively, is demonstrated. From the first lab on, students are challenged to express and interpret confidence intervals in order to form quantitative conclusions. Assessments reveal that many students find this to be surprisingly challenging

Above-threshold Ionization as Temporal Multi-slit Interference

When atoms are subjected to a laser pulse of sufficiently high intensity, electrons are ionized by absorbing multiple photons in excess of the ionization potential. The resulting sequence of peaks in the photoelectron spectrum separated by the energy of one photon is called ``above-threshold ionization\u27\u27 (ATI). This time-independent description of ATI invokes the language of photons, even though calculations are performed using the time-dependent Schrodinger equation with a classical electric field. We demonstrate that the energy-periodic structure of ATI can be understood from the interference of ionized electron wavepackets produced periodically each half-cycle of the laser field. Using this simple picture, rather analytic expressions for the ATI spectrum can be derived

Evaluation of image analysis techniques as applied to thermographs used in breast cancer detection

Due to the lack of a formal theory for designing image analysis systems it has been necessary to develop and implement a package of computer programs for evaluating image analysis techniques and designing image analysis systems. The package allows the image analysis system designer to experiment with different algorithms and techniques on his data. This package is described and a classification of image analysis techniques is given. Finally the package and a class of image analysis algorithms are applied to a particular problem: the computer assisted interpretation of breast thermograms for use in the early detection of breast cancer'. It is an important problem to due the observation that breast cancer increases surface temperature and that its early detection increases the five year survival rate of sufferers. Thermography is somewhat nonspecific but may be effectively used as a screening technique. An assessment is made of the algorithms applied to breast thermograms and proposals for future research are given

Confined Quantum Systems: Beyond Harmonic Order in Dimensional Perturbation Theory

We generalize the harmonic-order N-body DPT method for an isotropically confined quantum system of identical interacting bosons to first-anharmonic order and, in principle, higher orders. We introduce a graphical decomposition of the perturbative expansion of the N-body Hamiltonian. We calculate the Clebsch-Gordon coefficient tensors that couple together 3 irreducible representations of SN analytically, and analytically transformed the graphical basis to collective coordinates. We calculate the N-body wavefunction and density profile in general and have demonstrated agreement with an analytic model. We apply this formalism to the exactly-solvable example of a trapped gas of atoms interacting with a (fully-interacting) harmonic-oscillator "Hooke's law" interaction and compare with the dimensional expansion of the exact ground-state wavefunction and density profile. We report progress on the example of a cold gas BEC (with zero angular momentum)

Optimisation of a phosphate horizontal belt filter plant

The project covers the optimization and activities related to the improvement in process quality for the horizontal belt filter plants at Foskor Phalaborwa. Foskor Phalaborwa is a phosphate producing mining operation located on the eastern edge of Limpopo South Africa in a town called Phalaborwa. The need for a more in depth investigation and problem analysis focused on the filtration department at Foskor Phalaborwa was requested. The investigation and problem analysis of the problem areas at the filtration department serve as the back bone for the project conducted by the author. The project aims to identify the main causes for the filtration plant not operating within desired specifications for moisture content percentage of the discharged phosphate product. The identification of a number of issues that contribute to the failure of the filtration section in meeting their 8.5% moisture content goal for discharged product were identified. The most evident of the identified issues were that of plant operation and maintenance.Thesis (B Eng. (Industrial and Systems Engineering))--University of Pretoria, 2012

The thalamus as a low pass filter: filtering at the cellular level does not equate with filtering at the network level

In the mammalian central nervous system, most sensory information passes through primary sensory thalamic nuclei, however the consequence of this remains unclear. Various propositions exist, likening the thalamus to a gate, or a high pass filter. Here, using a simple leaky integrate and fire model based on physiological parameters, we show that the thalamus behaves akin to a low pass filter. Specifically, as individual cells in the thalamus rely on consistent drive to spike, stimuli that is rapidly and continuously changing over time such that it activates sensory cells with different receptive fields are unable to drive thalamic spiking. This means that thalamic encoding is robust to sensory noise, however it induces a lag in sensory representation. Thus, the thalamus stabilizes encoding of sensory information, at the cost of response rate