Manufacturing and Testing of a Variable Chord Extension for Helicopter Rotor Blades

Helicopters are still an indispensable addition to aviation in this day and age. They are characterized by their ability to master both forward flight and hover. These characteristics result in a wide range of possible operations. Key for the design of the rotor blades is a blade design that always represents a compromise between the different flight conditions, which enables save and efficient flight in the various flight conditions. In order to operate the rotor blade even more efficient in all flight conditions, a new morphing concept, the so-called linear variable chord extension, has been developed. Here, the blade chord length in the root area is changed with the help of an elastic skin to adapt it to the respective flight condition. The simulations performed for this concept showed a promising increase in overall helicopter performance. The fabrication of the resulting demonstra- tor as well as the tests in the whirl-tower and wind tunnel will be presented in this paper. The results of the tests show that the concept of linear variable chord extension has a positive influence and a great potential for hovering flight

Forging Fluorine-Containing Quaternary Stereocenters by a Light-Driven Organocatalytic Aldol Desymmetrization Process

Reported herein is a light-triggered organocatalytic strategy for the desymmetrization of achiral 2-fluoro-substi- tuted cyclopentane-1,3-diketones. The chemistry is based on an intermolecular aldol reaction of photochemically generated hydroxy-o-quinodimethanes and simultaneously forges two adjacent fully substituted carbon stereocenters, with one bearing a stereogenic carbon–fluorine unit. The method uses readily available substrates, a simple chiral organocatalyst, and mild reaction conditions to afford an array of highly function- alized chiral 2-fluoro-3-hydroxycyclopentanones

Emergency Department Clinicians’ Attitudes Toward Opioid Use Disorder and Emergency Department-initiated Buprenorphine Treatment: A Mixed-Methods Study

Introduction: Emergency department (ED) visits related to opioid use disorder (OUD) have increased nearly twofold over the last decade. Treatment with buprenorphine has been demonstrated to decrease opioid-related overdose deaths. In this study, we aimed to better understand ED clinicians’ attitudes toward the initiation of buprenorphine treatment in the ED.Methods: We performed a mixed-methods study consisting of a survey of 174 ED clinicians (attending physicians, residents, and physician assistants) and semi-structured interviews with 17 attending emergency physicians at a tertiary-care academic hospital.Results: A total of 93 ED clinicians (53% of those contacted) completed the survey. While 80% of respondents agreed that buprenorphine should be administered in the ED for patients requesting treatment, only 44% felt that they were prepared to discuss medication for addiction treatment. Compared to clinicians with fewer than five years of practice, those with greater experience were less likely to approve of ED-initiated buprenorphine. In our qualitative analysis, physicians had differing perspectives on the role that the ED should play in treating OUD. Most physicians felt that a buprenorphine-based intervention in the ED would be feasible with institutional support, including training opportunities, protocol support within the electronic health record, counseling and support staff, and a robust referral system for outpatient follow-up.Conclusion: ED clinicians’ perception of buprenorphine varied by years of practice and training level. Most ED clinicians did not feel prepared to initiate buprenorphine in the ED. Qualitative interviews identified several addressable barriers to ED-initiated buprenorphine

Wenn sich das Blatt wendet - formvariable Rotorblätter für Hubschrauber

Hubschrauber zeichnen sich durch ihre Fähigkeit aus, sowohl den Vorwärtsflug als auch den Schwebeflug zu beherrschen. Die Rotorblätter des Hauptrotors spielen dabei eine wichtige Rolle, weil deren Geometrie die benötigte Antriebsleistung und damit die Energieeffizienz des Hubschraubers beeinflusst. Für den Vorwärtsflug sind schlanke, nahezu ebene Blätter optimal, während für den Schwebeflug tordierte Blätter mit größerer Profiltiefe im Wurzelbereich vorteilhaft sind. Das neu entwickelte Konzept des adaptiven Rotors ermöglicht es, die Effizienz des Hubschraubers in beiden Flugzuständen zu maximieren, indem sich die Geometrie der Rotorblätter an die unterschiedlichen Anforderungen im laufenden Betrieb anpassen kann. Die benötigte Antriebsleistung reduziert sich dadurch im Schwebeflug um 7 %

Barriers to Accessing Acute Care for Newly Arrived Refugees

Introduction: Over the past decade, the number of refugees arriving in the United States (U.S.) has increased dramatically. Refugees arrive with unmet health needs and may face barriers when seeking care. However, little is known about how refugees perceive and access care when acutely ill. The goal of this study was to understand barriers to access of acute care by newly arrived refugees, and identify potential improvements from refugees and resettlement agencies.Methods: This was an in-depth, qualitative interview study of refugees and employees from refugee resettlement and post-resettlement agencies in a city in the Northeast U.S. Interviews were audiotaped, transcribed, and coded independently by two investigators. Interviews were conducted until thematic saturation was reached. We analyzed transcripts using a modified grounded theory approach.Results: Interviews were completed with 16 refugees and 12 employees from refugee resettlement/post-resettlement agencies. Participants reported several barriers to accessing acute care including challenges understanding the U.S. healthcare system, difficulty scheduling timely outpatient acute care visits, significant language barriers in all acute care settings, and confusion over the intricacies of health insurance. The novelty and complexity of the U.S. healthcare system drives refugees to resettlement agencies for assistance. Resettlement agency employees express concern with directing refugees to appropriate levels of care and report challenges obtaining timely access to sick visits. While receiving emergency department (ED) care, refugees experience communication barriers due to limitations in consistent interpretation services.Conclusion: Refugees face multiple barriers when accessing acute care. Interventions in the ED, outpatient settings, and in resettlement agencies, have the potential to reduce barriers to care. Examples could include interpretation services that allow for clinic phone scheduling and easier access to interpreter services within the ED. Additionally, extending the Refugee Medical Assistance program may limit gaps in insurance coverage and avoid insurance-related barriers to seeking care

Chemical warfare simulant-responsive polymer nanocomposites: Synthesis and evaluation

Nanomaterials that undergo a physical change upon chemical warfare agent (CWA) exposure can potentially be used in detectors to warn soldiers of their presence or in fabrics to provide on‐demand protection. In this study, hybrid nanoparticles (NPs) were prepared by grafting a CWA‐responsive polymer from a silicon dioxide (SiO₂) surface using ring opening metathesis polymerization; the covalent functionalization of the polymers on the NP surface was confirmed by gel permeation chromatography, dynamic light scattering, and transmission electron microscopy analysis. The polymer‐grafted SiO₂ NPs were found to undergo a pronounced decrease (approximately 200 nm) in their hydrodynamic radius upon exposure to CWA simulants trifluoroacetic acid and diethyl chlorophosphate in toluene. This decrease in hydrodynamic radius is attributed to the electrophile‐mediated ionization of the triarylmethanol responsive unit and represents a rare example of polycation formation leading to polymer chain collapse. We have ascribed this ionization‐induced collapse to the formation of a favorable stacking interaction between the planar triarylcations. These studies have important implications for the development of breathable fabrics that can provide on‐demand protection for soldiers in combat situations. Keywords: nanocomposites; stimuli-responsive; ROMP; organophosphates; triarylmethanolsDefense Threat Reduction Agency (DTRA) (Contract BA12PHM123