Impulse Correlation for Partially Filled Detonation Tubes

The effect of nozzles on the impulse obtained from a detonation tube of circular cross section has been the focus of many experimental and numerical studies. In these cases, the simplified detonation tube is closed at one end (forming the thrust surface) and open at the other end, enabling the attachment of an extension. A flowfield analysis of a detonation tube with an extension requires considering unsteady wave interactions making analytical and accurate numerical predictions difficult (especially in complicated extension geometries). To predict the impulse obtained from a detonation tube with an extension (considered a partially filled detonation tube), we utilize data from other researchers to generate a partial-fill correlation

Rome\u27s Doctrine of Justification

This brings us to the queston: Is the Roman Catholic or The Lutheran teaching the true Biblical doctrine of justification as it was once proclaimed by Jesus and His apostles? Or have both church bodies veered from divine truth? To answer these questions objectively is the main purpose of this thesis

New multiplexing scheme for monitoring fiber optic Bragg grating sensors in the coherence domain

A new multiplexing scheme for monitoring fiber optic Bragg gratings in the coherence domain has been developed. Grating pairs with different grating distances are distributed along a fiber line, and interference between their reflections is monitored with a scanning Michelson interferometer. The Bragg wavelength of the individual sensor elements is determined from the interference signal frequency

Point-of-sale marketing and context of marijuana retailers: Assessing reliability and generalizability of the marijuana retail surveillance tool

As recreational marijuana expands, standardized surveillance measures examining the retail environment are critical for informing policy and enforcement. We conducted a reliability and generalizability study using a previously developed tool involving assessment of a sample of 25 randomly selected Seattle recreational marijuana retailers (20 recreational; 5 recreational/medical) in 2017. The tool assessed: 1) contextual/neighborhood features (i.e., facilities nearby); 2) compliance/security (e.g., age-of-sale signage, age verification); and 3) marketing (i.e., promotions, product availability, price). We found that retailers were commonly within two blocks of restaurants (n = 23), grocery stores (n = 17), liquor stores (n = 13), and bars/clubs (n = 11). Additionally, two were within two blocks of schools, and four were within two blocks of parks. Almost all (n = 23) had exterior signage indicating the minimum age requirement, and 23 verified age. Two retailers had exterior ads for marijuana, and 24 had interior ads. Overall, there were 76 interior ads (M = 3.04; SD = 1.84), most commonly for edibles (n = 28). At least one price promotion/discount was recorded in 17 retailers, most commonly in the form of loyalty membership programs (n = 10) or daily/weekly deals (n = 10). One retailer displayed potential health harms/warnings, while three posted some health claim. Products available across product categories were similar; we also noted instances of selling retailer-branded apparel/ paraphernalia (which is prohibited). Lowest price/unit across product categories demonstrated low variability across retailers. This study documented high inter-rater reliability of the surveillance tool (Kappas = 0.73 to 1.00). In conclusion, this tool can be used in future research and practice aimed at examining retailers marketing practices and regulatory compliance. Keywords: Marijuana use, Retail environment, Marketing, Recreational marijuana, Measure developmen

Online identification and nonlinear control of the electrically stimulated quadriceps muscle

A new approach for estimating nonlinear models of the electrically stimulated quadriceps muscle group under nonisometric conditions is investigated. The model can be used for designing controlled neuro-prostheses. In order to identify the muscle dynamics (stimulation pulsewidth-active knee moment relation) from discrete-time angle measurements only, a hybrid model structure is postulated for the shank-quadriceps dynamics. The model consists of a relatively well known time-invariant passive component and an uncertain time-variant active component. Rigid body dynamics, described by the Equation of Motion (EoM), and passive joint properties form the time-invariant part. The actuator, i.e. the electrically stimulated muscle group, represents the uncertain time-varying section. A recursive algorithm is outlined for identifying online the stimulated quadriceps muscle group. The algorithm requires EoM and passive joint characteristics to be known a priori. The muscle dynamics represent the product of a continuous-time nonlinear activation dynamics and a nonlinear static contraction function described by a Normalised Radial Basis Function (NRBF) network which has knee-joint angle and angular velocity as input arguments. An Extended Kalman Filter (EKF) approach is chosen to estimate muscle dynamics parameters and to obtain full state estimates of the shank-quadriceps dynamics simultaneously. The latter is important for implementing state feedback controllers. A nonlinear state feedback controller using the backstepping method is explicitly designed whereas the model was identified a priori using the developed identification procedure

Application of synchrotron radiation for measurement of iron red-ox speciation in atmospherically processed aerosols

In this study, ambient atmospheric particulate matter samples were collected using a size-resolved impactor sampler from three urban sites. The purpose of this study is to gain a better understanding of transformations of aerosol-bound iron as it is processed in the atmosphere. Thus, the aerosol samples were artificially aged to represent long-term transport (10 to 40 days) or short-term transport (1 to 10 days) and were measured for iron at several time points. At each time point, iron was measured in each size fraction using three different techniques; 1) inductively coupled plasma-mass spectrometry (ICPMS) for total iron, 2) x-ray absorbance near edge structure (XANES) spectroscopy for the measurement of total Fe(II) and Fe(III), and 3) a wet-chemical method to measure soluble Fe(II) and Fe(III). Prior to aging, the XANES spectroscopy results show that a majority (>60% for each size fraction) of the total iron in the PM is in the form of Fe(III). Fe(III) was shown to be a significant fraction of the soluble iron (sometimes >50%), but the relative significance of Fe(III) was found to vary depending on the site. Overall, the total soluble iron depended on the sampling site, but values ranged from less than 1% up to about 20% of the total iron. Over the course of the 40 day aging period, we found moderate changes in the relative Fe(II)/Fe(III) content. A slight increase was noted in the coarse (>2.5 µm) fraction and a slight decrease in the 0.25 to 0.5 µm fraction. The soluble fraction generally showed (excepting one day) a decrease of soluble Fe(II) prior to 10 days of aging, followed by a relatively constant concentration. In the short-term transport condition, we found that the sub-micron fraction of soluble Fe(II) spikes at 1 to 3 days of aging, then decreases to near the initial value at around 6 to 10 days. Very little change in soluble Fe(II) was observed in the super-micron fraction