Algorithm for in-flight gyroscope calibration

An optimal algorithm for the in-flight calibration of spacecraft gyroscope systems is presented. Special consideration is given to the selection of the loss function weight matrix in situations in which the spacecraft attitude sensors provide significantly more accurate information in pitch and yaw than in roll, such as will be the case in the Hubble Space Telescope mission. The results of numerical tests that verify the accuracy of the algorithm are discussed

In-flight determination of spacecraft magnetic bias independent of attitude

A simple algorithm for the in-flight determination of the magnetic bias of a spacecraft is presented. The algorithm, developed for use during the Hubble Space Telescope mission, determines this bias independently of any attitude estimates and requires no spacecraft sensor data other than that from the spacecraft magnetometer(s). Estimates of the algorithm's accuracy and results from a number of numerical studies on the use of this algorithm are also presented

Augmentation of the Egg Parasitoid Anaphes iole (Hymenoptera: Mymaridae) for Lygus hesperus (Heteroptera:Miridae) Management in Strawberries

The impact of repeated releases of Anaphes iole (Girault) on the development of Lygus hesperus Knight populations and fruit damage in commercial strawberry fields was evaluated. Following the release of 37,000 parasitoids per hectare, 50% of L. hesperus eggs were parasitized. Parasitism levels declined rapidly; after 96 h, parasitism levels had declined to an average of only 3.5% in these plots. A release rate of 12,300 parasitoids per hectare produced parasitism levels of 6.3 and 7.0% 48 and 96 h after release, respectively. The high release rate of the parasitoids resulted in a 43% reduction in the number of L. hesperus nymphs and a 22% reduction in the amount of fruit damage. The low release rate responded in a comparable fashion, with nymph and damage levels 19 and 14% lower than control plots, respectively. The effect of the parasitoid releases on L. hesperus populations increased through time. On average, there was a proportionally greater reduction in nymph densities in the higher release rate plots during the latter half of the season. In all the plots, there was a significant relationship between the number of L. hesperus nymphs found in the plot and the amount of fruit damage. The significance of these results to management of L. hesperus in strawberries is discusse

On the Decelerating Shock Instability of Plane-Parallel Slab with Finite Thickness

Dynamical stability of the shock compressed layer with finite thickness is investigated. It is characterized by self-gravity, structure, and shock condition at the surfaces of the compressed layer. At one side of the shocked layer, its surface condition is determined via the ram pressure, while at the other side the thermal pressure supports its structure. When the ram pressure dominates the thermal pressure, we expect deceleration of the shocked layer. Especially, in this paper, we examine how the stratification of the decelerating layer has an effect on its dynamical stability. Performing the linear perturbation analysis, a {\it more general} dispersion relation than the previous one obtained by one of the authors is derived. It gives us an interesting information about the stability of the decelerating layer. Importantly, the DSI (Decelerating Shock Instability) and the gravitational instability are always incompatible. We also consider the evolution effect of the shocked layer. In the early stages of its evolution, only DSI occurs. On the contrary, in the late stages, it is possible for the shocked layer to be unstable for the DSI (in smaller scale) and the gravitational instability (in larger scale). Furthermore, we find there is a stable range of wavenumbers against both the DSI and the gravitational instability between respective unstable wavenumber ranges. These stable modes suggest the ineffectiveness of DSI for the fragmentation of the decelerating slab.Comment: 17 pages, 6 figures. The Astrophysical Journal Vol.532 in pres

Effect of electric field on the photoluminescence of polymer-inorganic nanoparticles composites

We report on the effect of electric field on the photoluminescence, PL, from a composite consisting of a conjugated polymer mixed with zinc oxide nanoparticles. We have found that in the absence of electric field PL emission from the composite film has two maxima in the blue and green-yellow regions. Application of a voltage bias to planar gold electrodes suppresses the green-yellow emission and shifts the only PL emission maximum towards the blue region. Current-voltage characteristics of the polymer-nanoparticles composite exhibit the non-linear behavior typical of non-homogeneous polymer-inorganic structures. Generation of excited states in the composite structure implies the presence of several radiative recombination mechanisms including formation of polymer-nanoparticle complexes including exciplex states and charge transfer between the polymer and nanoparticle that can be controlled by an electric field.Comment: 5 pages, 5 figures. accepted for publication in Solid State Communication

From Diagnosis to Satisfaction in Multiple Sclerosis: A Swiss Patient Survey Highlighting the Importance of the First Diagnostic Consultation

Background: An early treatment start with disease modifying therapies (DMT) and long-term adherence is crucial in the treatment of people with multiple sclerosis (PwMS) to prevent future disability. Objectives: To gain information on the diagnostic process, decision making, treatment start and adherence with regard to DMT as well as satisfaction in PwMS in Switzerland to optimize management of PwMS. Methods: A survey was conducted between June 2017 and March 2018 in six hospital-based MS centres and eight private practices in Switzerland. PwMS according to the 2010 McDonald criteria, aged 18–60 years, having a clinical isolated syndrome, relapsing remitting MS, or secondary progressive MS were eligible. The survey contained 40 questions, covering participants’ background and circumstances, treatment decisions, therapy start, treatment adherence, and satisfaction (EKNZ Req-2016-00701). Results: 212 questionnaires were returned for analysis. Of these, 125 (59.0%) were answered by patients treated by practice-based neurologists and 85 (40.1%) by patients treated in hospitals. That PwMS were satisfied overall with current medical care, that they were free of relapses and disease progression, and that they were able to live independently were the main goals of patients. Satisfaction was reflected by an early therapy start and a high adherence to DMT in our cohort. The treating neurologist played a major role in this regard. Furthermore, a satisfactory first diagnostic consultation (FDC) was crucial for successful long-term patient care positively influencing an early treatment start, longer duration of the initial therapy, as well as adherence to treatments and general satisfaction. Conclusion: The treating neurologist and especially a satisfactory FDC play a major role for the successful long-term treatment of PwMS. Detailed information on various aspects of the disease and time with the treating neurologist seems to be of major importance