Yosemite Conference on Ionospheric Plasma in the Magnetosphere: Sources, Mechanisms and Consequences, meeting report

The sixth biennial Yosemite topical conference and the first as a Chapman Conference was held on February 3 to 6, 1986. Due to the recent changes in our perception of the dynamics of the ionospheric/magnetospheric system, it was deemed timely to bring researchers together to discuss and contrast the relative importance of solar versus terrestrial sources of magnetospheric plasma. Although the solar wind was once thought to dominate the supply of plasma in the Earth's magnetosphere, it is now thought that the Earth's ionosphere is a significant contributor. Polar wind and other large volume outflows of plasma have been seen at relatively high altitudes over the polar cap and are now being correlated with outflows found in the magnetotail. The auroral ion fountain and cleft ion fountain are examples of ionospheric sources of plasma in the magnetosphere, observed by the Dynamics Explorer 1 (DE 1) spacecraft. The conference was organized into six sessions: four consisting of prepared oral presentations, one poster session, and one session for open forum discussion. The first three oral sessions dealt separately with the three major topics of the conference, i.e., the sources, mechanisms, and consequences of ionospheric plasma in the magnetosphere. A special session of invited oral presentations was held to discuss extraterrestrial ionospheric/magnetospheric plasma processes. The poster session was extended over two evenings during which presenters discussed their papers on a one-on-one basis. The last session of the conferences was reserved for open discussions of those topics or ideas considered most interesting or controversial

Electrostatically Tunable Meta-Atoms Integrated With In Situ Fabricated MEMS Cantilever Beam Arrays

Two concentric split ring resonators (SRRs) or meta-atoms designed to have a resonant frequency of 14 GHz are integrated with microelectromechanical systems cantilever arrays to enable electrostatic tuning of the resonant frequency. The entire structure was fabricated monolithically to improve scalability and minimize losses from externally wire-bonded components. A cantilever array was fabricated in the gap of both the inner and outer SRRs and consisted of five evenly spaced beams with lengths ranging from 300 to 400 μm. The cantilevers pulled in between 15 and 24 V depending on the beam geometry. Each pulled-in beam increased the SRR gap capacitance resulting in an overall 1-GHz shift of the measured meta-atom resonant frequency

Multibody aircraft study, volume 2

The potential benefits of a multibody aircraft when compared to a single body aircraft are presented. The analyses consist principally of a detailed point design analysis of three multibody and one single body aircraft, based on a selected payload of 350,000 kg (771,618 lb), for final aircraft definitions; sensitivity studies to evaluate the effects of variations in payload, wing semispan body locations, and fuel price; recommendations as to the research and technology requirements needed to validate the multibody concept. Two, two body, one, three body, and one single body aircraft were finalized for the selected payload, with DOC being the prime figure of merit. When compared to the single body, the multibody aircraft showed a reduction in DOC by as much as 11.3 percent. Operating weight was reduced up to 14 percent, and fly away cost reductions ranged from 8.6 to 13.4 percent. Weight reduction, hence cost, of the multibody aircraft resulted primarily from the wing bending relief afforded by the bodies being located outboard on the wing

Nutrient Content of Runoff Water From Rice Fields

Current perception is that nutrient runoff from croplands is a significant contributor to poor water quality in some areas. While extensive research has been conducted to survey and ameliorate this problem for several upland crops, little work has been done to evaluate the problem with flooded rice (Oryza sativa, L.) soils. Since rice production utilizes a major portion of the total irrigation water usage for certain areas, it is important to understand the contribution of rice production to non-point source N and P in surface water. Several production fields were selected to evaluate the concentrations of nutrients in the floodwater at selected distances across the field, including inlet and exit. The fields were evaluated in either 1990, 1991, or 1992 and were managed by the individual rice producer. Water samples were collected from several locations within each field weekly following establishment of the permanent flood and analyzed for inorganic N (NH4-N, No3-N, and NO2-N) and soluble P. The N concentrations in the floodwater normally peaked following N fertilizer application but rapidly declined and remained below 1 mg N L-1. Water management resulted in some variation among locations with respect to the timing and magnitude of these peaks. The P concentrations were usually highest near the well and declined to less than 0.05 mg P L-1 as the water moved across the field. This was attributed to plant uptake, uptake by algae, and sediment deposition. The data indicates that rice fields have the potential to be utilized as a filtration system to reduce the nutrient load of irrigation water similar to constructed wetlands . Use of catfish pondwater, in comparison to well water, resulted in only slightly higher total N and total P levels with higher amounts of the nutrients in the organic form. Although the P levels were high enough to potentially contribute to eutrophication of surface water, the water exiting the field was lower than at the entry point irrespective of the source. Also, the total P (organic + inorganic) concentration was less than 0.05 mg P L- 1

Helping Students Create Their Own Books the Dialogic Way

This article explores one technique that is consistent with the student-centered paradigm in language education: student-generated books. First, benefits of student-generated are dis-cussed. Then, the article explores the crucial area of maintaining student ownership of their own books. The next topic explained in the article is why dialog is important as the students are developing their books. Finally, it is suggested that book creation works for students of all ages and levels, with examples given of students at the early childhood level and of second language students at university level

SRRs Embedded with MEMS Cantilevers to Enable Electrostatic Tuning of the Resonant Frequency

A microelectromechanical systems (MEMS) cantilever array was monolithically fabricated in the gap region of a split ring resonator (SRR) to enable electrostatic tuning of the resonant frequency. The design consisted of two concentric SRRs each with a set of cantilevers extending across the split region. The cantilever array consisted of five beams that varied in length from 300 to 400 μm, with each beam adding about 2 pF to the capacitance as it actuated. The entire structure was fabricated monolithically to reduce its size and minimize losses from externally wire bonded components. The beams actuate one at a time, longest to shortest with an applied voltage ranging from 30–60 V. The MEMS embedded SRRs displayed dual resonant frequencies at 7.3 and 14.2 GHz or 8.4 and 13.5 GHz depending on the design details. As the beams on the inner SRR actuated the 14.2 GHz resonance displayed tuning, while the cantilevers on the outer SRR tuned the 8.4 GHz resonance. The 14.2 GHz resonant frequency shifts 1.6 GHz to 12.6 GHz as all the cantilevers pulled-in. Only the first two beams on the outer cantilever array pulled-in, tuning the resonant frequency 0.4 GHz from 8.4 to 8.0 GHz

DE 1 RIMS operational characteristics

The Retarding Ion Mass Spectrometer (RIMS) on the Dynamics Explorer 1 spacecraft observes both the thermal and superthermal (50 eV) ions of the ionosphere and inner magnetosphere. It is capable of measuring the detailed species distribution function of these ions in many cases. It was equipped with an integral electrometer to permit in-flight calibration of the detector sensitivities and variations thereof. A guide to understanding the RIMS data set is given. The reduction process from count rates to physical quantities is discussed in some detail. The procedure used to establish in-flight calibration is described, and results of a comparison with densities from plasma wave measurements are provided. Finally, a discussion is provided of various anomalies in the data set, including changes of channeltron efficiency with time, spin modulation of the axial sensor heads, apparent potential differences between the sensor heads, and failures of the radial head retarding potential sweep and of the -Z axial head aperture plane bias. Studies of the RIMS data set should be conducted only with a thorough awareness of the material presented here, or in collaboration with one of the scientists actively involved with RIMS data analysis

School-based intervention study examining approaches for well-being and mental health literacy of pupils in Year 9 in England: study protocol for a multischool, parallel group cluster randomised controlled trial (AWARE)

Introduction The prevalence of emotional difficulties in young people is increasing. This upward trend is largely accounted for by escalating symptoms of anxiety and depression. As part of a public health response, there is increasing emphasis on universal prevention programmes delivered in school settings. This protocol describes a three-arm, parallel group cluster randomised controlled trial, investigating the effectiveness and cost-effectiveness of two interventions, alongside a process and implementation evaluation, to improve mental health and well-being of Year 9 pupils in English secondary schools. Method A three-arm, parallel group cluster randomised controlled trial comparing two different interventions, the Youth Aware of Mental Health (YAM) or the Mental Health and High School Curriculum Guide (The Guide), to Usual Provision. Overall, 144 secondary schools in England will be recruited, involving 8600 Year 9 pupils. The primary outcome for YAM is depressive symptoms, and for The Guide it is intended help-seeking. These will be measured at baseline, 3–6 months and 9–12 months after the intervention commenced. Secondary outcomes measured concurrently include changes to: positive well-being, behavioural difficulties, support from school staff, stigma-related knowledge, attitudes and behaviours, and mental health first aid. An economic evaluation will assess the cost-effectiveness of the interventions, and a process and implementation evaluation (including a qualitative research component) will explore several aspects of implementation (fidelity, quality, dosage, reach, participant responsiveness, adaptations), social validity (acceptability, feasibility, utility), and their moderating effects on the outcomes of interest, and perceived impact. Ethics and dissemination This trial has been approved by the University College London Research Ethics Committee. Findings will be published in a report to the Department for Education, in peer-reviewed journals and at conferences

Non-Abelian Geometric Phase, Floquet Theory, and Periodic Dynamical Invariants

For a periodic Hamiltonian, periodic dynamical invariants may be used to obtain non-degenerate cyclic states. This observation is generalized to the degenerate cyclic states, and the relation between the periodic dynamical invariants and the Floquet decompositions of the time-evolution operator is elucidated. In particular, a necessary condition for the occurrence of cyclic non-adiabatic non-Abelian geometrical phase is derived. Degenerate cyclic states are obtained for a magnetic dipole interacting with a precessing magnetic field.Comment: Plain LaTeX, 13 pages, accepted for publication in J. Phys. A: Math. Ge