Application of inertial instruments for DSN antenna pointing and tracking

The feasibility of using inertial instruments to determine the pointing attitude of the NASA Deep Space Network antennas is examined. The objective is to obtain 1 mdeg pointing knowledge in both blind pointing and tracking modes to facilitate operation of the Deep Space Network 70 m antennas at 32 GHz. A measurement system employing accelerometers, an inclinometer, and optical gyroscopes is proposed. The initial pointing attitude is established by determining the direction of the local gravity vector using the accelerometers and the inclinometer, and the Earth's spin axis using the gyroscopes. Pointing during long-term tracking is maintained by integrating the gyroscope rates and augmenting these measurements with knowledge of the local gravity vector. A minimum-variance estimator is used to combine measurements to obtain the antenna pointing attitude. A key feature of the algorithm is its ability to recalibrate accelerometer parameters during operation. A survey of available inertial instrument technologies is also given

Northwest Forest Plan The First 15 Years (1994-2008): Watershed Condition Status and Trend

We used two data sets to evaluate stream and watershed condition for sixth-field watersheds in each aquatic province within the Northwest Forest Plan (NWFP) area: stream data and upslope data. The stream evaluation was based on inchannel data (e.g., substrate, pieces of large wood, water temperature, pool frequency, and macroinvertebrates) we sampled from 2002 to 2009 (193 watersheds) as part of a repeating sample design. We just completed our first round of sampling, so only current condition was calculated for this data set. When condition scores for the inchannel data were grouped into categories, relatively few fell into the low (10 percent) and very low (1 percent) categories. The majority of inchannel attribute scores fell into the moderate (35 percent) and high (41 percent) condition ranges, with relatively few (12 percent) in the very high category. For low-scoring watersheds, water temperature was often the most influential factor. Aquatic invertebrate scores also appeared influential in producing the low scores. An evaluation of upslope and riparian (watershed-wide) conditions for all 1,379 sixth-field watersheds in the NWFP area with significant federal ownership was based on mapped data, including road metrics from U.S. Forest Service and Bureau of Land Management geographic information system road layers and vegetation metrics derived from satellite imagery. Watershed-wide condition scores were calculated for 1994 and 2008, and the difference between these scores was used to represent trend. Regarding status, the overall condition scores of the 1,379 watersheds mostly fell into the low (21 percent), moderate (27 percent), high (26 percent), and very high (22 percent) categories; relatively few watersheds scored in the very low (4 percent) category. The majority of watersheds (69 percent) had a positive change in condition scores (trend). Of those with larger positive changes, most were driven by both improvements in road (decommissioning) and vegetation (natural growth) scores. The greatest negative score changes were caused by the Biscuit Fire and other fires along the eastern side of the Cascades. Half of the fire-affected watersheds were in congressional reserves, 35 percent in late-successional reserves, and 15 percent in matrix (lands identified for timber production)

Force Training Neural Network Potential Energy Surface Models

Machine learned chemical potentials have shown great promise as alternatives to conventional computational chemistry methods to represent the potential energy of a given atomic or molecular system as a function of its geometry. However, such potentials are only as good as the data they are trained on, and building a comprehensive training set can be a costly process. Therefore, it is important to extract as much information from training data as possible without further increasing the computational cost. One way to accomplish this is by training on molecular forces in addition to energies. This allows for three additional labels per atom within the molecule. Here we develop a neural network potential energy surface for studying a hydrogen transfer reaction between two conformers of C5H5. We show that, for a much smaller training set, force training can greatly improve the accuracy of the model compared to only training to energies. We also demonstrate the importance of choosing the proper force to energy weight ratio for the loss function to minimize the model test error

Flexible structure control laboratory development and technology demonstration

An experimental structure is described which was constructed to demonstrate and validate recent emerging technologies in the active control and identification of large flexible space structures. The configuration consists of a large, 20 foot diameter antenna-like flexible structure in the horizontal plane with a gimballed central hub, a flexible feed-boom assembly hanging from the hub, and 12 flexible ribs radiating outward. Fourteen electrodynamic force actuators mounted to the hub and to the individual ribs provide the means to excite the structure and exert control forces. Thirty permanently mounted sensors, including optical encoders and analog induction devices provide measurements of structural response at widely distributed points. An experimental remote optical sensor provides sixteen additional sensing channels. A computer samples the sensors, computes the control updates and sends commands to the actuators in real time, while simultaneously displaying selected outputs on a graphics terminal and saving them in memory. Several control experiments were conducted thus far and are documented. These include implementation of distributed parameter system control, model reference adaptive control, and static shape control. These experiments have demonstrated the successful implementation of state-of-the-art control approaches using actual hardware

Electron Cloud Measurements in Fermilab Booster

Fermilab Booster synchrotron requires an intensity upgrade from 4.5x1012 to 6.5x1012 protons per pulse as a part of Fermilab's Proton Improvement Plan-II (PIP-II). One of the factors which may limit the high-intensity performance is the fast transverse instabilities caused by electron cloud effects. According to the experience in the Recycler, the electron cloud gradually builds up over multiple turns inside the combined function magnets and can reach final intensities orders of magnitude greater than in a pure dipole. Since the Booster synchrotron also incorporates combined function magnets, it is important to measure the presence of electron cloud. The presence or apparent absence of the electron cloud was investigated using two different methods: measuring bunch-by-bunch tune shift by changing the bunch train structure at different intensities and propagating a microwave carrier signal through the beampipe and analyzing the phase modulation of the signal. This paper presents the results of the two methods and corresponding simulation results conducted using PyECLOUD software.Comment: International Particle Accelerator Conference 202

A prospective clinical, cost and environmental analysis of a clinician-led virtual urology clinic

INTRODUCTION: Minimally invasive parathyroidectomy (MIP) for primary hyperparathyroidism is dependent upon accurate prediction of single-gland disease on the basis of preoperative imaging and biochemistry. The aims of this study were to validate currently available predictive models of single-gland disease in two UK cohorts and to determine if these models can facilitate MIP. MATERIAL AND METHODS: We collected data prospectively from our weekly follow-up virtual clinic over a continuous four-month period between July and September 2017. RESULTS: In total, we reviewed 409 patients. Following virtual clinic consultation, 68.5% of our patients were discharged from further follow-up. The majority of our patients (male 57.7%, female 55.5%) were of working age. The satisfaction scores were high, at 90.1%, and there were no reported adverse events as a result of using the virtual clinic. Our calculated cost savings were £18,744, with a predicted 12-month cost saving of £56,232. The creation of additional face-to-face clinic capacity has created an estimated 12-month increase in tariff generation for our unit of £72,072. In total, 4623 travel miles were avoided by patients using the virtual clinic, with an estimated avoided carbon footprint of 0.35-1.45 metric tonnes of CO2e, depending on mode of transport. Our predicted 12-month avoided carbon footprint is 1.04-4.04 metric tonnes of CO2e. CONCLUSIONS: Our virtual clinic model has demonstrated a trifecta of positive outcomes, namely, clinical, financial and environmental benefits. The environmental importance and benefits of a virtual clinic should be promoted as a social enterprise value when engaging stakeholders in setting up such a urological service. We propose the adoption of our virtual clinic model in those urological units considering this method of telemedicine

Growth factor restriction impedes progression of wound healing following cataract surgery: identification of VEGF as a putative therapeutic target

Secondary visual loss occurs in millions of patients due to a wound-healing response, known as posterior capsule opacification (PCO), following cataract surgery. An intraocular lens (IOL) is implanted into residual lens tissue, known as the capsular bag, following cataract removal. Standard IOLs allow the anterior and posterior capsules to become physically connected. This places pressure on the IOL and improves contact with the underlying posterior capsule. New open bag IOL designs separate the anterior capsule and posterior capsules and further reduce PCO incidence. It is hypothesised that this results from reduced cytokine availability due to greater irrigation of the bag. We therefore explored the role of growth factor restriction on PCO using human lens cell and tissue culture models. We demonstrate that cytokine dilution, by increasing medium volume, significantly reduced cell coverage in both closed and open capsular bag models. This coincided with reduced cell density and myofibroblast formation. A screen of 27 cytokines identified nine candidates whose expression profile correlated with growth. In particular, VEGF was found to regulate cell survival, growth and myofibroblast formation. VEGF provides a therapeutic target to further manage PCO development and will yield best results when used in conjunction with open bag IOL designs

A prospective clinical, cost and environmental analysis of a clinician-led urology virtual clinic

Introduction: A virtual clinic is a form of telemedicine where contact between clinical teams and patients occur without face-to-face consultation. Our study aims to quantify the clinical, financial and environmental benefits of our virtual urology clinic. / Material and methods: We collected data prospectively from our weekly follow-up virtual clinic over a continuous four-month period between July and September 2017. / Results: In total, we reviewed 409 patients. Following virtual clinic consultation, 68.5% of our patients were discharged from further follow-up. The majority of our patients (male 57.7%, female 55.5%) were of working age. The satisfaction scores were high, at 90.1%, and there were no reported adverse events as a result of using the virtual clinic. Our calculated cost savings were £18,744, with a predicted 12-month cost saving of £56,232. The creation of additional face-to-face clinic capacity has created an estimated 12-month increase in tariff generation for our unit of £72,072. In total, 4623 travel miles were avoided by patients using the virtual clinic, with an estimated avoided carbon footprint of 0.35–1.45 metric tonnes of CO2e, depending on mode of transport. Our predicted 12-month avoided carbon footprint is 1.04–4.04 metric tonnes of CO2e. / Conclusions: Our virtual clinic model has demonstrated a trifecta of positive outcomes, namely, clinical, financial and environmental benefits. The environmental importance and benefits of a virtual clinic should be promoted as a social enterprise value when engaging stakeholders in setting up such a urological service. We propose the adoption of our virtual clinic model in those urological units considering this method of telemedicine

Localization of substance P-like and enkephalin-like immunoreactivity within preganglionic terminals of the avian ciliary ganglion: light and electron microscopy

The avian ciliary ganglion receives its only recognized input from the nucleus of Edinger-Westphal. This is known to be a cholinergic input. In the present study, using fluorescein isothiocyanate and peroxidase- antiperoxidase immunohistochemical methods, substance P-like and enkephalin-like immunoreactivity has been found within preganglionic terminals of the avian ciliary ganglion. The ciliary ganglion is known to consist of two distinct cell populations: small choroid cells that project to the smooth muscle coat of the choroid and large ciliary neurons that send axons to both the iris and the ciliary body. Preganglionic terminals on choroid cells consist of small boutonal endings, whereas ciliary neurons receive a calyx-like cap ending around the hilus of the cell. Substance P-like and enkephalin-like immunoreactivity was localized to preganglionic axons and to both boutonal and calyx-like terminations upon cells of the ciliary ganglion. Electron microscopic studies of both substance P-like and enkephalin-like immunoreactive terminals revealed small clear core vesicles (approximately 58 nm in diameter) and two sizes of dense core vesicles (approximately 85 and approximately 119 nm in diameter). Immunoreactive staining was observed only in the smaller dense core vesicles. The unlabeled clear core vesicles were clustered at synaptic release sites, while the immunoreactive and larger unlabeled dense core vesicles usually were not near these synaptic specializations. These observations strongly imply that neuropeptides co-occur with acetylcholine in preganglionic axons of the ciliary ganglion