On the tidal effects in the motion of artificial satellites

Trigonometrical expansion for calculation of tidal effects on motion of artificial satellite

Geomagnetic modeling by optimal recursive filtering

The results of a preliminary study to determine the feasibility of using Kalman filter techniques for geomagnetic field modeling are given. Specifically, five separate field models were computed using observatory annual means, satellite, survey and airborne data for the years 1950 to 1976. Each of the individual field models used approximately five years of data. These five models were combined using a recursive information filter (a Kalman filter written in terms of information matrices rather than covariance matrices.) The resulting estimate of the geomagnetic field and its secular variation was propogated four years past the data to the time of the MAGSAT data. The accuracy with which this field model matched the MAGSAT data was evaluated by comparisons with predictions from other pre-MAGSAT field models. The field estimate obtained by recursive estimation was found to be superior to all other models

Gravitational instantons, self-duality and geometric flows

We discuss four-dimensional "spatially homogeneous" gravitational instantons. These are self-dual solutions of Euclidean vacuum Einstein's equations with potentially non-vanishing cosmological constant. They are endowed with a product structure R \times M_3 leading to a natural foliation into three-dimensional subspaces evolving in Euclidean time. For a large class of three-dimensional subspaces, the dynamics coincides with the geometric flow on the three-dimensional homogeneous slice, driven by the Ricci tensor plus an so(3) gauge connection. The metric on the three-dimensional space is related to the vielbein of the three-dimensional subspace, while the gauge field is inherited from the anti-self-dual component of the four-dimensional Levi--Civita connection.Comment: 14 page

Occupational Therapists\u27 Experiences with Ethical and Occupation-based Practice in Hospital Settings

Changes in health care delivery practices are impacting the provision of care in all venues. Occupational therapists working in hospital settings strive to meet professional mandates for occupation-based practice within a medical-model system. Ethical practice is another aspect of service provision vulnerable to contextual influences. The aims of the two studies reported here were to explore occupational therapists’ experiences with occupation-based practice, and with ethical issues, in hospital settings. Grounded theory methods were employed for both studies. Data were collected via individual, semi-structured interviews with 22 participants for the first study. For the second study, nine participants participated in individual, semi-structured interviews, journaling, and follow up interviews. Data analysis resulted in four emergent themes for each study. The main themes of the first study were Occupation-based practice expresses professional identity; Occupation-based practice is more effective; Occupation-based practice can be challenging in the clinic; and, Occupation-based practice takes creativity to adapt. The four themes of the second study were Anything less would be unethical: Key issues; I trust my gut: Affective dimension of ethical practice; Ethical practice is expected but challenging; and, It takes a village. Occupational therapists negotiate challenges inherent in contemporary hospital-based practice to provide occupation-based services and to practice ethically. Occupation-based practice is perceived to be more effective than biomedical approaches to intervention. Therapists must employ creative strategies to overcome challenges presented by medical-model service delivery contexts in order to provide occupation-based interventions. In comparison to other health care professionals working in adult rehabilitation practice, occupational therapists experience both common and unique ethical issues. A discovery of this study was that occupational therapists also experience ethical tensions related to team members’ and families’ sometimes subtle, and less frequently explicit, requests to falsify recommendations in documentation. Experiences with ethical issues include an inherent affective component in the form of moral distress and a strong sense of caring. The impact of systemic/organizational and relational forces is a reality that contemporary occupational therapists must negotiate in order to provide occupation-based and ethical practice

The Role of Proton Transfer in Heterogeneous Transformations of Hydrocarbons

Heterogeneous catalysis is essential for the transformation of light hydrocarbons into chemical feedstocks. Many of the catalysts that mediate these transformations consist of isolated metal ions on the surface of a metal oxide support, such as silica or alumina. Due to the complexity of these catalysts, studying the active site and mechanism of these reactions is difficult. Surface organometallic chemistry (SOMC) could offer a solution to this problem by allowing the synthesis of well-defined surface organometallic species. This approach has been used to study the reactions of light hydrocarbons with isolated metal species on silica and alumina surfaces. These studies showed that proton transfers play a key role in the reactions of many hydrocarbons. The mechanisms of these reactions and their role in some common catalytic cycles are discussed

Evaluation of Ocean Color Scanner (OCS) photographic and digital data: Santa Barbara Channel test site, 29 October 1975 overflight

A summary of Ocean Color Scanner data was examined to evaluate detection and discrimination capabilities of the system for marine resources, oil pollution and man-made sea surface targets of opportunity in the Santa Barbara Channel. Assessment of the utility of OCS for the determination of sediment transport patterns along the coastal zone was a secondary goal. Data products provided 1975 overflight were in digital and analog formats. In evaluating the OCS data, automated and manual procedures were employed. A total of four channels of data in digital format were analyzed, as well as three channels of color combined imagery, and four channels of black and white imagery. In addition, 1:120,000 scale color infrared imagery acquired simultaneously with the OCS data were provided for comparative analysis purposes

A protocol paper on the preservation of identity: understanding the technology adoption patterns of older adults with age-related vision loss (ARVL)

There are a growing number of older adults with age-related vision loss (ARVL) for whom technology holds promise in supporting their engagement in daily activities. Despite the growing presence of technologies intended to support older adults with ARVL, there remains high rates of abandonment. This phenomenon of technology abandonment may be partly explained by the concept of self-image, meaning that older adults with ARVL avoid the use of particular technologies due to an underlying fear that use of such technologies may mark them as objects of pity, ridicule, and/or stigmatization. In response to this, the proposed study aims to understand how the decision-making processes of older adults with ARVL, as it relates to technology adoption, is influenced by the negotiation of identity. The study protocol will justify the need for this critical ethnographic study, unpack the theoretical underpinnings of this work, detail the sampling/recruitment strategy, describe the methods which included a home tour, go-along, and semi-structured in-depth interview, as well as the collective approach taken to analyze the data. The protocol concludes by examining the ethical tensions associated with this study, including a focus on the methods adopted as well as the ethical challenges inherent when working with an older adult population experiencing vision loss