X-56A Structural Dynamics Ground Testing Overview and Lessons Learned

The X-56A Multi-Utility Technology Testbed (MUTT) is a subscale, fixed-wing aircraft designed for high-risk aeroelastic flight demonstration and research. Structural dynamics ground testing for model validation was especially important for this vehicle because the structural model was directly used in the development of a flight control system with active flutter suppression capabilities. Structural dynamics ground tests of the X-56A MUTT with coupled rigid-body and structural modes provided a unique set of challenges. An overview of the ground vibration test (GVT) and moment of inertia (MOI) test setup and execution is presented. The series of GVTs included the wing by itself attached to a strongback and complete vehicle at two mass conditions: empty and full fuel. Two boundary conditions for the complete-vehicle test were studied: on landing gear and suspended free-free. Pitch MOI tests were performed using a compound pendulum method and repeated with two different pendulum lengths for independent verification. The original soft-support test configuration for the GVT used multiple bungees, resulting in unforeseen coupling interactions between the soft-support bungees and the vehicle structural modes. To resolve this problem, the soft-support test setup underwent multiple iterations. The various GVT configurations and boundary-condition modifications are highlighted and explained. Lessons learned are captured for future consideration when performing structural dynamics testing with similar vehicles

Remotely controlled mirror of variable geometry for small angle x-ray diffraction with synchrotron radiation

A total-reflecting mirror of 120-cm length was designed and built to focus synchrotron radiation emanating from the electron-positron storage ring at the Stanford Linear Accelerator Center (SPEAR). The reflecting surface is of unpolished float glass. The bending and tilt mechanism allows very fine control of the curvature and selectability of the critical angle for wavelengths ranging from 0.5 to 3.0 Å. Elliptical curvature is used to minimize aberrations. The mirror is placed asymmetrically onto the ellipse so as to achieve a tenfold demagnification of the source. The bending mechanism reduces nonelastic deformation (flow) and minimizes strains and stresses in the glass despite its length. Special design features assure stability of the focused image. The mirror reduces the intensity of shorter wavelength harmonics by a factor of approximately 100

Quantification of anterior translation of tibia over femur using Lachmeter in anterior cruciate ligament reconstruction with hamstring tendon autograft

Background: The anterior cruciate ligament (ACL) is an important restraint on anterior tibial translation of the knee. Arthroscopic ACL reconstruction using hamstring tendon autograft is the most widely accepted surgical procedure for ACL insufficiency. This study is assessing the effect of ACL reconstruction by hamstring tendon autograft on the anteroposterior stability of the knee joint by measuring the side-to-side difference of anterior tibial translation using the Lachmeter. We are also assessing the functional outcome of the same surgery using international knee documentation committee (IKDC) score. Methods: The study included 30 patients who were admitted for ACL reconstruction with hamstring tendon autograft. The side-to-side difference of anterior tibial translation was assessed by using Lachmeter preoperatively and postoperatively at the end of the 1st, 3rd, and 6th months. The IKDC score was assessed preoperatively and postoperatively at the end of 6th month. Results: The mean Lachmeter value of respondents in the current study was 4.31±0.56 mm during the preoperative period. Lachmeter values were 2.79±0.42 mm, 2.09±0.42 mm, and 1.29±0.39 mm, respectively, at the end of the first, third, and sixth months postoperatively. Mean preoperative and postoperative 6th month IKDC scores were 55.83±7.7 and 89.20±5.3 respectively. Conclusions: There is significant serial improvement in the side-to-side difference of anterior tibial translation in the 6 months of post operative period following ACL reconstruction using hamstring tendon autograft. The improved IKDC score from preoperative to postoperative level is also indicating a positive functional outcome

Loss of memory for auditory-spatial associations following unilateral medial temporal-lobe damage

The goal of the present experiment was to determine the role of medial temporal-lobe structures in episodic memory of auditory-spatial associations. By using a two-alternative forced choice paradigm in which an association between eight different sounds and their spatial location must be recognized, learning abilities over 10 learning sessions were tested in 19 patients who had undergone a right or a left medial temporal-lobe resection for the relief of intractable seizures as well as in nine normal control participants. The data demonstrated that significant learning took place over the successive sessions for all the participants. In addition, the results showed that patients with left but not right medial temporal-lobe lesion were impaired in this learning task as compared to normal participants, suggesting the predominant implication of left medial temporal-lobe structures in auditory-spatial associative learning. The predominant role of left hemisphere structures in this memory task could be explained by a spatial categorical coding, which was enhanced by the use of eight loud-speakers. This result also suggests that the ability to store an episodic event associated with a rich spatial (or temporal) context depends on the left medial temporal-lobe structures. Thus, this finding provides an interesting parallel with data obtained in the visual modality by documenting for the first time the role of the left medial temporal-lobe in episodic learning of auditory-spatial associations

Commercial users panel

The discussions of motives and requirements for telerobotics application demonstrated that, in many cases, lack of progress was a result not of limited opportunities but of inadequate mechanisms and resources for promoting opportunities. Support for this conclusion came from Telerobotics, Inc., one of the few companies devoted primarily to telerobot systems. They have produced units for such diverse applications as nuclear fusion research, particle accelerators, cryogenics, firefighting, marine biology/undersea systems and nuclear mobile robotics. Mr. Flatau offered evidence that telerobotics research is only rarely supported by the private sector and that it often presents a difficult market. Questions on the mechanisms contained within the NASA technology transfer process for promoting commercial opportunities were fielded by Ray Gilbert and Tom Walters. A few points deserve emphasis: (1) NASA/industry technology transfer occurs in both directions and NASA recognizes the opportunity to learn a great deal from industry in the fields of automation and robotics; (2) promotion of technology transfer projects takes a demand side approach, with requests to industry for specific problem identification. NASA then proposes possible solutions; and (3) comittment ofmotivated and technically qualified people on each end of a technology transfer is essential

The impact of COVID-19 on anxiety and wellbeing for families of individuals with Special Education Needs and Disabilities in the UK

COVID-19 has affected people across the world. However, it has been suggested that individuals with Special Education Needs and Disabilities (SEND) and their families might have been particularly impacted by the first national lockdown in the UK. In contrast to previous studies, the current study examined wellbeing and anxiety at different time points and included a control group matched for family situation. Parents of 402 individuals with SEND reported on their own anxiety and wellbeing as well as that of their son/daughter at three time points (before COVID-19, when COVID-19 pandemic started, and during the national lockdown). In addition, data from 186 typically developing (TD) siblings was obtained. Repeated measures ANOVAs and regression analyses showed that, although both individuals with SEND and their TD siblings showed increased anxiety across the three time points, levels of anxiety were not predicted by age, gender or health. Instead, levels of anxiety in the SEND group, but not the TD siblings, were predicted by awareness about COVID-19, diagnosis of an existing anxiety disorder as well as parental anxiety. In addition, whilst TD individuals were reported to increasingly worry about social related issues as well as family related issues, those with SEND were reported to worry about issues related to school closures. These findings show that COVID-19 impacts the wellbeing of those with SEND differently to that of their TD siblings and that school closures have a particular effect on this group. Further implications for policy impact and interventions are discussed

Seeding Techniques for Alfalfa to Improve Subirrigated Meadows

Improving quality and quantity of forage harvested from poor condition, subirrigated hay meadows in the Nebraska Sand Hills is critical to the winter forage reserve of livestock producers. Alfalfa (Medicago sativa L.) is the most commonly used legume for meadow improvement. Broadcast seeding (11.2 kg/ha) was compared to sod seeding (11.2 kg/ha) as a method to introduce alfalfa into an alkaline subirrigated meadow (Fluvaquentic Haplustolls). Before seeding, the study area received 78.5 kg/ha phosphorous. Paraquat (0.29 kg/ha) was applied to one-half of the area to suppress plant competition and provide qualitative information on treatment consistency across a range of sod competition. Lo-till sod seeding was accomplished with a power tillage seeder. Seedling density was determined in spring the following year. Broadcast alfalfa had a greater seedling density than sod-seeded alfalfa (38.4 and 19.1 plants/m2, respectively, p=.09). Apparently, paraquat had no effect on seedling establishment and tended to reduce total yield. Yields the year of seeding, using a two harvest scheme, were greater for broadcast compared to sod-seeded alfalfa (p=.02). However, there was no significant difference between yields of broadcast alfalfa and control

Quantitative Magnetization Transfer in In Vivo Healthy Human Skeletal Muscle at 3 T

The value of quantitative MR methods as potential biomarkers in neuromuscular disease is being increasingly recognized. Previous studies of the magnetization transfer ratio have demonstrated sensitivity to muscle disease. The aim of this work was to investigate quantitative magnetization transfer imaging of skeletal muscle in healthy subjects at 3 T to evaluate its potential use in pathological muscle. The lower limb of 10 subjects was imaged using a 3D fast low-angle shot acquisition with variable magnetization transfer saturation pulse frequencies and amplitudes. The data were analyzed with an established quantitative two-pool model of magnetization transfer. T1 and B1 amplitude of excitation radiofrequency field maps were acquired and used as inputs to the quantitative magnetization transfer model, allowing properties of the free and restricted proton pools in muscle to be evaluated in seven different muscles in a region of interest analysis. The average restricted pool T2 relaxation time was found to be 5.9 ± 0.2μs in the soleus muscle and the restricted proton pool fraction was 8 ± 1%. Quantitative magnetization transfer imaging of muscle offers potential new biomarkers in muscle disease within a clinically feasible scan time. Magn Reson Med, 2010. © 2010 Wiley-Liss, Inc

Discrimination, labour markets and the Labour Market Prospects of Older Workers: What Can a Legal Case Teach us?

As governments become increasingly concerned about the fiscal implications of the ageing population, labour market policies have sought to encourage mature workers to remain in the labour force. The ‘human capital’ discourses motivating these policies rest on the assumption that older workers armed with motivation and vocational skills will be able to return to fulfilling work. This paper uses the post-redundancy recruitment experiences of former Ansett Airlines flight attendants to develop a critique of these expectations. It suggests that policies to increase older workers’ labour market participation will not succeed while persistent socially constructed age- and gender- typing shape labour demand. The conclusion argues for policies sensitive to the institutional structures that shape employer preferences, the competitive rationality of discriminatory practices, and the irresolvable tension between workers’ human rights and employers’ property rights