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  1. Pharmaceutical cocrystals comprise one active pharmaceutical ingredient (API) and at least one small molecule excipient coformer. While solvent evaporation and mechanochemistry are the preferred methods for their synthesis, some cocrystals are known to form spontaneously at ambient conditions when powders of input materials are mixed—a process not yet fully understood. Aqueous humidity is also known to accelerate spontaneous cocrystal formation. We report here the extent of spontaneous cocrystallization for 14 cocrystal systems, at four levels of humidity. The binary cocrystals in our study consist of a model API (caffeine, theophylline, nicotinamide) and a small chain diacid coformer (oxalic acid, malonicmore »acid, maleic acid, fumaric acid, succinic acid, glutaric acid). The spontaneous cocrystal formation was monitored ex situ by powder X-ray diffraction over several weeks. Our results show cocrystal formation in all 14 systems to varying extent and are consistent with literature reports that higher humidity correlates with more rapid cocrystal formation. We find that cocrystals containing smaller coformers often form faster. Based on our findings, we identify several cocrystals as candidates for future study.« less
    Free, publicly-accessible full text available January 1, 2023
  2. In this work-in-progress (WIP) study, we begin to identify explicit links between ethics and diversity, equity, and inclusion (DEI) in engineering education and closely related fields. We use systematic literature review procedures coupled with a qualitative content analytic approach to identify these explicit links within engineering education journals and conference papers. Through this WIP, we identify preliminary themes that represent explicit discourses connecting ethics and DEI and we cite associated literature. We unpack four themes that have a prominent presence in the abstracts that we have reviewed: cultural, global, social, and sustainable. These explicit connections will support future systematic reviewmore »procedures wherein we will aim to identify implicit DEI and ethics connections via an analysis of whole manuscripts. While preliminary, we hope that these four themes can prompt strategies to connect ethics and DEI more purposefully when teaching towards these and related topics.« less
    Free, publicly-accessible full text available October 1, 2022
  3. Hyperspectral imaging systems are becoming widely used due to their increasing accessibility and their ability to provide detailed spectral responses based on hundreds of spectral bands. However, the resulting hyperspectral images (HSIs) come at the cost of increased storage requirements, increased computational time to process, and highly redundant data. Thus, dimensionality reduction techniques are necessary to decrease the number of spectral bands while retaining the most useful information. Our contribution is two-fold: First, we propose a filter-based method called interband redundancy analysis (IBRA) based on a collinearity analysis between a band and its neighbors. This analysis helps to remove redundantmore »bands and dramatically reduces the search space. Second, we apply a wrapper-based approach called greedy spectral selection (GSS) to the results of IBRA to select bands based on their information entropy values and train a compact convolutional neural network to evaluate the performance of the current selection. We also propose a feature extraction framework that consists of two main steps: first, it reduces the total number of bands using IBRA; then, it can use any feature extraction method to obtain the desired number of feature channels. We present classification results obtained from our methods and compare them to other dimensionality reduction methods on three hyperspectral image datasets. Additionally, we used the original hyperspectral data cube to simulate the process of using actual filters in a multispectral imager.« less
    Free, publicly-accessible full text available September 1, 2022
  4. Snik, Frans ; Kupinski, Meredith K. ; Shaw, Joseph A. (Ed.)
    Free, publicly-accessible full text available August 1, 2022
  5. Free, publicly-accessible full text available July 28, 2022
  6. As the applications of hyperspectral imaging rapidly diversify, the need for accurate radiometric calibration of these imaging systems is becoming increasingly important. When performing radiometric measurements, the polarization response of the imaging system can be of particular interest if the scene contains partially polarized objects. For example, when imaging a scene containing water, surface reflections from the water will be partially polarized, possibly affecting the response of the imaging system. In this paper, the polarization response of a Resonon, Inc. visible near-infrared (VNIR) hyperspectral imaging system is assessed across a spectral range of 400nm to 1000 nm, with a spectralmore »resolution of 2.1 nm. Efforts are currently underway to correct for the observed polarization response of the imaging system.« less
  7. Kim, Moon S. ; Cho, Byoung-Kwan ; Chin, Bryan A. (Ed.)