An examination of the relations between rotor vibratory loads and airframe vibrations

Harmonic rotor hub loads and airframe interactions in steady flight are reviewed, with regard to the objective of achieving lower airframe vibration by modifying blade root loads. Flight test and wind tunnel data are reviewed, along with sample fuselage response data. Trends which could provide a generalized approach to the above objective are found to be very limited. Recent analytical and corresponding experimental blade tuning modifications are reviewed and compared. Rotor vibratory load modification and substantial vibration changes were achieved over a wide range of rotor operating conditions

Test results from a dynamic model dynaflex rotor

A one-fifth scale dynamic model of the Sikorsky Dynaflex rotor was tested in hover and in forward flight conditions in a wind tunnel. The Dynaflex rotor features an advanced composite structure which flexes to provide a constant speed universal joint action. Testing concentrated on confirming that the stability and dynamic response of the rotor were satisfactory. Lift conditions of up to .11 Ct/sigma and advance ratios as high as .46 were reached. Vibratory loads were compared to those of articulated rotors. The Dynaflex rotor concept appears to be a practical concept from the standpoint of dynamic response and stability

AAPT Diagnostic Criteria for Chronic Sickle Cell Disease Pain

Pain in sickle cell disease (SCD) is associated with increased morbidity, mortality, and high health care costs. Although episodic acute pain is the hallmark of this disorder, there is an increasing awareness that chronic pain is part of the pain experience of many older adolescents and adults. A common set of criteria for classifying chronic pain associated with SCD would enhance SCD pain research efforts in epidemiology, pain mechanisms, and clinical trials of pain management interventions, and ultimately improve clinical assessment and management. As part of the collaborative effort between the Analgesic, Anesthetic, and Addiction Clinical Trial Translations Innovations Opportunities and Networks public-private partnership with the U.S. Food and Drug Administration and the American Pain Society, the Analgesic, Anesthetic, and Addiction Clinical Trial Translations Innovations Opportunities and Networks-American Pain Society Pain Taxonomy initiative developed the outline of an optimal diagnostic system for chronic pain conditions. Subsequently, a working group of experts in SCD pain was convened to generate core diagnostic criteria for chronic pain associated with SCD. The working group synthesized available literature to provide evidence for the dimensions of this disease-specific pain taxonomy. A single pain condition labeled chronic SCD pain was derived with 3 modifiers reflecting different clinical features. Future systematic research is needed to evaluate the feasibility, validity, and reliability of these criteria. Perspective: An evidence-based classification system for chronic SCD pain was constructed for the Analgesic, Anesthetic, and Addiction Clinical Trial Translations Innovations Opportunities and Networks-American Pain Society Pain Taxonomy initiative. Applying this taxonomy may improve assessment and management of SCD pain and accelerate research on epidemiology, mechanisms, and treatments for chronic SCD pain

A Novel Comprehensive Verification Method for Multifocal RapidArc Radiosurgery Treatments

<p><bold>Purpose:</bold> Radiosurgery has become a widely used procedure in the treatment of both solid tumors and secondary metastases in the brain. In cases with multiple brain lesions, isocenters are typically set up for each target, a process which can take hours and become very uncomfortable for the patient. Recently, multifocal treatments with a single isocenter have emerged as a solution. With the high doses delivered to small regions during radiosurgery, the importance of treatment verification is paramount, especially when delivering high doses to regions off isocenter. </p><p><bold>Methods:</bold> A 5-arc RapidArc radiosurgery plan with a single isocenter and 5 targets was used to treat a dosimeter placed within a RPC-type head and neck phantom. The treatment was delivered five times at varying prescription doses, depending on the sensitivity of the PRESAGE dosimeter used. The delivered dose distribution was measured using an in-house optical-CT system and compared to the Eclipse-planned dose distribution using dose volume histograms and Gamma analysis.</p><p><bold>Results:</bold> Reasonable dose agreement was measured between the majority of the dosimeters and the Eclipse plan (80-85% pass rate at 5%/3 mm Gamma critera). The failing voxels were located on the periphery of the dosimeter at regions of extremely high or low dose, suggesting a dose dependent stability of the PRESAGE formulation. The formulation with the best temporal stability had a much higher Gamma pass rate of 98% at 3%/2mm criteria.</p><p><bold>Conclusions:</bold> The potential of accurate delivery of the complex radiosurgery plan was demonstrated with one of the three formulations of PRESAGE. While agreement was worse in the other formulations, the problem seemed to be an easily-fixable stability issue, resulting in improper scaling of doses. Replication of the most stable formulation would provide an excellent tool for verification of radiosurgery treatment delivery and other complex procedures.</p>Thesi

UC Santa Cruz in the Mid-1970s: A Time of Transition, Volume I: John Marcum, Sigfried Puknat, Robert Adams, John Ellis, and Paul Niebanck

On January 23, 1976, UC Santa Cruz’s second chancellor, Mark N. Christensen, resigned from office. He had served the campus from July 1974 to January 1976. These two oral history volumes, comprised of interviews conducted between 1976 and 1980, set Christensen’s resignation within the broader context of a tumultuous and transitional moment in the campus’s history. Founding Chancellor Dean McHenry had brought to fruition his singular vision for UC Santa Cruz as an innovative institution of higher education that emphasized undergraduate teaching centered in residential colleges, each with a specific intellectual theme and architectural design, within the framework of what he envisioned as a major public research university. McHenry oversaw the planning and building of UCSC from 1961 until his retirement in June 1974. In the early years, UCSC drew high caliber students and gained considerable national visibility as an innovative university. But by the mid-1970s, applications were declining and enrollments were on the verge of falling. Internally, the campus was fracturing along fault lines created by debates over the colleges’ academic role and over the relative weight to be placed on research and teaching, while UCSC struggled to weather a variety of external political and economic pressures and to hold its own as a distinctive campus within the traditional University of California.Christensen’s tenure as chancellor rather tragically ended in controversy after only eighteen months. Although most of the faculty liked Christensen as a person, they lost confidence in his ability to govern the campus. The Regional History Project never conducted an oral history with Mark Christensen, who passed away in 2003. But former director Randall Jarrell completed a series of interviews with key faculty members and administrators who had been directly involved in the Christensen case. Jarrell decided to withhold publication of these oral histories due to their sensitive political nature at the time. Now, nearly four decades later, we are able to publish these volumes as part of the Project’s Institutional History of UCSC series.This is a two-volume publication. The five oral histories in volume one not only illuminate the painful events leading up to the resignation of Chancellor Christensen, they capture and reflect on the “McHenry years” and on a complex and challenging period in the history of what was then a young, still experimental, and somewhat vulnerable campus of the University of California. The second volume contains a brief oral history with George Von Der Muhll conducted by Randall Jarrell in 1976 and then a much longer, follow-up oral history with George Von Der Muhll conducted by Irene Reti in 2014, in which Von der Muhll shares his thoughts not only on the Christensen administration, but also on the reaggregation and reorganization programs of the late 1970s, in which he played a central role. He also contemplates UC Santa Cruz as an experiment in public higher education, from the perspective of fifty years after the campus was founded. For reasons of chronology and length, we decided to dedicate a separate volume to Von Der Muhll’s interview. A third oral history volume, Daniel H. McFadden: The Chancellor Mark Christensen Era at UC Santa Cruz, 1974-1976, also originally part of this series was published in 2012 and is available on the Regional History website