In situ and ex situ catalysis in biomass fast pyrolysis

Biomass pyrolysis oils, or bio-oils, are produced from the pyrolysis of lignocellulose and are considered a renewable source of carbon. Bio-oil contains many different compounds, comprising a wide array of different oxygen-containing functional groups. The relative concentrations of these compounds can be affected by process conditions that give rise to secondary effects caused by transport limitations or by the presence of catalysts, either in situ, as in the case of natural Alkali and Alkaline Earth Metals (AAEM), or ex situ, such as the hydrodeoxygenation of pyrolysis vapors using molybdenum oxide. Analysis of the micropyrolyzer system calculated there to be negligible heat transfer limitations, however mass transfer limitations were apparent when an excessive sample weight (\u3e800 μg) was applied. Secondary effects were found to be catalyzed by char and included the decomposition/dehydration of levoglucosan to low molecular weight products, furans, and dehydrated pyranose, as well as secondary char and gas formation. Levoglucosan yield was also diminished upon the addition of added AAEMs, specifically sodium chloride and calcium chloride. The diminishment was most severe in cellulose pyrolysis where the levoglucosan yield decreased by 85% when NaCl was added at a loading of 1.75 wt.%. Utilizing bio-oil in the production of fuels or chemicals poses challenges due to the high oxygen content of bio-oil. Numerous efforts have been carried out to remove oxygen efficiently while minimizing the loss of carbon. Here, the hydrodeoxygenation of biomass pyrolysis vapors was conducted with a tandem micropyrolyzer system using low pressure hydrogen, a molybdenum oxide catalyst situated ex situ of the pyrolysis reactor, and cellulose, lignin, and corn stover feedstocks. The highly oxygenated pyrolysis vapors were effectively converted to hydrocarbons by the MoO3 catalyst. Oxygenated compounds were observed in the products from the first feed injection but not in succeeding injections. However, when the catalyst was pre-reduced to a more active state, the products were fully deoxygenated from the first injection. The products included mainly linear alkanes (C1 to C6) and monocyclic aromatics. Remarkably, the total hydrocarbon yield for each feedstock was as high as ~75-90 C% from the volatile carbon (excluding char). Using different MoO3 catalyst loadings for cellulose hydrodeoxygenation found alkanes to dominate at higher loadings, while at lower loadings alkene yields were increased. However, at too low of a loading, the pyrolysis vapors were not totally deoxygenated. The hydrodeoxygenation of monooxygenate C4 compounds found hydroxyl groups to be the most readily reacted and ether linkages to be the most recalcitrant. In general, the reactivity towards deoxygenation of the tested oxygen-containing functional groups was observed to be C-OH \u3e C=O \u3e C-O-C. Several cellulose pyrolysis model compounds were tested, including methyl glyoxal, glycolaldehyde, furfural, 5-hydroxymethylfurfural, and levoglucosan, and found the same general trend to be present, except for levoglucosan, which was totally converted and did not yield any oxygenated species despite containing two ether linkages. Pyridine temperature programmed desorption studies found the acidity of MoO3 to greatly increase after reduction for 1 hr under H2 flow. The general reaction pathway was observed to include carbonyl/hydroxyl hydrogenation/dehydrogenation, alkene isomerization, and alkene hydrogenation

NebuFlask: Advancing Usability of Nebulizers to Increase Patient Compliance

Nebulizers are ubiquitous in the world of medicine. Any patient diagnosed with asthma, pneumonia, cystic fibrosis, chronic obstructive pulmonary disorder (COPD), or any other severe lung disease often use a nebulizer in order to deliver medication to the lungs. Although these technologies are quite common, they are surprisingly outdated. The most commonly used nebulizers today are bulky, loud, awkward to carry around, and must be plugged into an outlet. These aspects of the nebulizer make it a nuisance to use in general and almost impossible to use outside of the home or clinic. The ultrasonic and mesh nebulizers do address most of these issues, however the cost and maintenance required for these types of nebulizers prevent them from being used popularly. By redesigning the jet nebulizer into a water bottle form with a quieter air compressor, we were able to build a prototype that is lighter, quieter, and more discreet than commercially available nebulizers today. This human-centered design empowers users to nebulize in any setting, effectively increasing patient compliance with prescribed medications

Expressive Monotonic Neural Networks

The monotonic dependence of the outputs of a neural network on some of its inputs is a crucial inductive bias in many scenarios where domain knowledge dictates such behavior. This is especially important for interpretability and fairness considerations. In a broader context, scenarios in which monotonicity is important can be found in finance, medicine, physics, and other disciplines. It is thus desirable to build neural network architectures that implement this inductive bias provably. In this work, we propose a weight-constrained architecture with a single residual connection to achieve exact monotonic dependence in any subset of the inputs. The weight constraint scheme directly controls the Lipschitz constant of the neural network and thus provides the additional benefit of robustness. Compared to currently existing techniques used for monotonicity, our method is simpler in implementation and in theory foundations, has negligible computational overhead, is guaranteed to produce monotonic dependence, and is highly expressive. We show how the algorithm is used to train powerful, robust, and interpretable discriminators that achieve competitive performance compared to current state-of-the-art methods across various benchmarks, from social applications to the classification of the decays of subatomic particles produced at the CERN Large Hadron Collider.Comment: 9 pages, 4 figures, ICLR 2023 final submissio

Moderation of Enterprise Social Networks – A Literature Review from a Corporate Perspective

The implementation of internal social collaboration technologies confronts corporations with new challenges. Former unidirectional information flows become multidirectional and user-content driven networks. Prior research describes the successful implementation as a challenging management task with employees’ usage at the center of attention. Consequently, corporations need to select a moderation style to encourage the usage. The degree of corporate engagement might have repercussions on the contribution behavior. We conduct a structured literature review to identify pre-existing IS contributions to the moderation phenomenon in social media tools, which help to explain on how to moderate these communication platforms in the enterprise context. We reviewed over 150 articles on the subject and assessed 31 articles in depth on the degree of corporate engagement and user content encouragement. We analyze the identified literature for gaps in understanding the phenomenon and provide a first assessment of three different moderation approaches and give implication for future research

Introduction to Force-dependent Kinematics:Theory and Application to Mandible Modeling

Knowledge of the muscle, ligament, and joint forces is important when planning orthopedic surgeries. Since these quantities cannot be measured in vivo under normal circumstances, the best alternative is to estimate them using musculoskeletal models. These models typically assume idealized joints, which are sufficient for general investigations but insufficient if the joint in focus is far from an idealized joint. The purpose of this study was to provide the mathematical details of a novel musculoskeletal modeling approach, called force-dependent kinematics (FDK), capable of simultaneously computing muscle, ligament, and joint forces as well as internal joint displacements governed by contact surfaces and ligament structures. The method was implemented into the anybody modeling system and used to develop a subject-specific mandible model, which was compared to a point-on-plane (POP) model and validated against joint kinematics measured with a custom-built brace during unloaded emulated chewing, open and close, and protrusion movements. Generally, both joint models estimated the joint kinematics well with the POP model performing slightly better (root-mean-square-deviation (RMSD) of less than 0.75 mm for the POP model and 1.7 mm for the FDK model). However, substantial differences were observed when comparing the estimated joint forces (RMSD up to 24.7 N), demonstrating the dependency on the joint model. Although the presented mandible model still contains room for improvements, this study shows the capabilities of the FDK methodology for creating joint models that take the geometry and joint elasticity into account.</jats:p

The National Feral Swine Program, National Strategy – The First Five Years

In 2014, through Congressional direction, the Animal Plant Health Inspection Service (APHIS) National Feral Swine Damage Management Program was created. While feral swine damage management was certainly not new to APHIS Wildlife Services, this mandate enabled a programmatic and unified approach in combating the destructive forces of feral swine throughout the United States and its territories. Recognizing the variance in environmental conditions and regulatory processes throughout the states, APHIS’ strategy is to provide resources and expertise at a national level, while allowing flexibility to manage operational activities from a local or state perspective. Having completed the first five years of this pursuit, APHIS has compiled a report which serves to describe the program and its components, ongoing collaborative research, the operational approach, and the outreach and communication campaigns. This presentation provided an overview of this report, introducing accomplishments achieved, setbacks encountered, and future considerations. The report will be electronically available on the USDA/APHIS/Wildlife Services web page at: https://www.aphis.usda.gov/aphis/ourfocus/wildlifedamag