Henri Temianka Correspondence; (wardell)

This collection contains material pertaining to the life, career, and activities of Henri Temianka, violin virtuoso, conductor, music teacher, and author. Materials include correspondence, concert programs and flyers, music scores, photographs, and books.https://digitalcommons.chapman.edu/temianka_correspondence/2994/thumbnail.jp

Quasi-local contribution to the scalar self-force: Geodesic Motion

We consider a scalar charge travelling in a curved background spacetime. We calculate the quasi-local contribution to the scalar self-force experienced by such a particle following a geodesic in a general spacetime. We also show that if we assume a massless field and a vacuum background spacetime, the expression for the self-force simplifies significantly. We consider some specific cases whose gravitational analog are of immediate physical interest for the calculation of radiation reaction corrected orbits of binary black hole systems. These systems are expected to be detectable by the LISA space based gravitational wave observatory. We also investigate how alternate techniques may be employed in some specific cases and use these as a check on our own results.Comment: Final Phys. Rev. D version. 24 pages, revtex4. Minor typos correcte

The principle of maximum entropy production in a simple model of a convection cell

Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Physics, 1992.Includes bibliographical references (leaves 52-53).by David W. Hogg.B.S

Quasi-local contribution to the scalar self-force: Non-geodesic Motion

We extend our previous calculation of the quasi-local contribution to the self-force on a scalar particle to general (not necessarily geodesic) motion in a general spacetime. In addition to the general case and the case of a particle at rest in a stationary spacetime, we consider as examples a particle held at rest in Reissner-Nordstrom and Kerr-Newman space-times. This allows us to most easily analyse the effect of non-geodesic motion on our previous results and also allows for comparison to existing results for Schwarzschild spacetime.Comment: 11 pages, 1 figure, corrected typo in Eq. 2.

Generic effective source for scalar self-force calculations

A leading approach to the modelling of extreme mass ratio inspirals involves the treatment of the smaller mass as a point particle and the computation of a regularized self-force acting on that particle. In turn, this computation requires knowledge of the regularized retarded field generated by the particle. A direct calculation of this regularized field may be achieved by replacing the point particle with an effective source and solving directly a wave equation for the regularized field. This has the advantage that all quantities are finite and require no further regularization. In this work, we present a method for computing an effective source which is finite and continuous everywhere, and which is valid for a scalar point particle in arbitrary geodesic motion in an arbitrary background spacetime. We explain in detail various technical and practical considerations that underlie its use in several numerical self-force calculations. We consider as examples the cases of a particle in a circular orbit about Schwarzschild and Kerr black holes, and also the case of a particle following a generic time-like geodesic about a highly spinning Kerr black hole. We provide numerical C code for computing an effective source for various orbital configurations about Schwarzschild and Kerr black holes.Comment: 24 pages, 7 figures, final published versio

Towards sustainable management: Southern Africa's Afromontane, and Western Australia's Jarrah forests

We review the history of forest management in two southern hemisphere forest types: Western Australia's jarrah Eucalyptus marginata forests and the Afromontane forests of southern Africa to determine approaches for achieving sustainable forest management. We argue that despite major differences in the ecology and biogeography of these two forest types, a shared pattern in the history of exploitation may provide lessons for achieving sustainable management across forest types. While advanced silvicultural understanding has long been achieved in both forest types, this in itself has not led to either sustainable management or to public acceptance of forest management regimes. In both areas an early, rapid expansion of uncontrolled timber removal and in the number of operating timber mills was followed by controlled exploitation, a rapid decline in the numbers of mills and, more recently, a general decline in yield. In neither case was increased concern about conservation responsible for the reduction in either yield or in employment in the industry. Rather, in WA jarrah forests, amendments in purpose and tenure were subsequent to the loss of most mills and towns, while in southern Africa's Afromontane forests, timber workers were pensioned by 1939 because of scanty remaining merchantable timber. In the jarrah forests, we believe that the conflict generated by conservation concerns, reduced timber industry employment, and reduced benefits flowing to the communities adjacent to the logged forests, has fueled dissatisfaction with forest management outcomes. This has led to a new process in the preparation of forest management plans. Increased accountability and more realistic expectations of timber yield following productivity declines may mean the current plan for the forests of Western Australia can be used as an example to achieve sustainability in Mediterranean forest ecosystems. However, general acceptance of management regimes may not be achieved until the scale of logging operations is matched with local sustainability criteria. Increasing the area of reserves will not accelerate this process, but rather may impede it. Setting conservative overall yield estimates, and achieving local sustainability seem both to be necessary to achieve general acceptance of management regimes. A sustainable management system appears to have been achieved in the Afromontane forests and has led to the development and maintenance of support for small-scale operations to supply local timber needs from State managed forests. In both environments such a process is achievable because of the high value and specialized nature of the native forest timber resource, and because of the increasing availability of general purpose timber from plantations

Improving the triple bottom line returns from smallholder tree farms in the Philippines: A systems approach

This paper outlines the application of systems thinking in investigating ways to improve the returns to smallholder tree farmers in the Philippines. The paper illustrates how a systems approach was used in the conceptualisation of the project and how systems thinking facilitated a shared understanding of the how each individual’s research contributed to the broader project activities. Systems thinking has also been used in the design and implementation of various project activities. Three examples are provided. The first example illustrates how a systems diagram was developed which outlined the direct and indirect linkages between biophysical data on tree farms and various activities designed to increase returns. The second example illustrates how the suggested approach for improving the flow of information concerning tree registration, harvest and transportation regulations and approval mechanisms link with various project activities and have been informed by a series of action research workshops. The third example illustrates how systems thinking has been applied to understand the factors affecting the production of high quality tree seedlings and to investigate the effect of policy interventions on improving the quality of seedlings available to smallholders

MEASUREMENT OF SMALLHOLDER TREE FARMS ON LEYTE ISLAND

This paper describes the field techniques used to measure timber volume and log quality from smallholder tree farms on Leyte Island conducted as part of ACIAR project ASEM/2003/052, Improving Financial Returns from Smallholder Tree Farms in the Philippines . Tree farms were included in the sample if they were 0.1 ha or greater in area and contained 100 or more trees. Paired circular blocks were chosen for measurement, one in the centre and one on the edge of the tree block. Where tree farms included multiple blocks of trees, two circular plots were established within each block. For each tree over 10 cm diameter at breast height (dbh) in the plot, measurements were made of dbh, diameter at the base (db), tree height, location, crown depth, crown radius, bearing and distance of each tree with reference to the plot centre. Estimates of log lengths and grade that each tree was expected to yield were also recorded, along with a sketch of each tree. In addition, data were collected on tree farm, block and plot characteristics, and were entered into an ACCESS database for subsequent analysis

Consequences of Broadscale Timber Plantations for Biodiversity in Cleared Rainforest Landscapes of Tropical and Subtropical Australia

In Australia, as in many countries, there has been a shift in timber production from native forests to plantations. While plantations are primarily considered an efficient means of producing timber, there is increasing interest in their potential contribution to biodiversity conservation. Plantations may have both positive and negative consequences for biodiversity, at a range of scales. We compiled a list of these consequences from the literature, and used them to assess plantation scenarios proposed for cleared rainforest landscapes in tropical and subtropical Australia. The scenarios were monocultures of: (i) hoop pine, (ii) exotic pine and (iii) eucalypts; (iv) mixed species plantations; (v) a mosaic of monoculture plantations; and (vi) a mosaic of plantations and ecological restoration plantings. Of these scenarios, plantations of eucalypts and exotic pines have the least positive consequences for biodiversity: they have little or no intrinsic value in rainforest landscapes, provide poor quality habitat for rainforest biota, and (particularly eucalypts) are characterised by a relatively open canopy which in cleared landscapes favours the recruitment of grasses and other weeds. The three scenarios based on plantations of rainforest trees have similar, moderately positive consequences for biodiversity, while a mosaic of plantations and restoration plantings has the most positive consequences for biodiversity in cleared rainforest landscapes. All scenarios may have negative impacts on biodiversity conservation if plantations replace remnant forest, provide habitat for weeds, or the tree species used in plantations or their genes escape into native forests. In practice, the relative importance of positive and negative impacts, and hence the ranking of scenarios may vary with landscape forest cover. Scenarios with strongly positive consequences for biodiversity would be favoured for the reforestation of heavily cleared landscapes, whereas scenarios with few negative consequences for biodiversity would be favoured in well-forested landscapes. Consequently, any plantation of rainforest trees may have acceptable consequences for biodiversity in well-forested landscapes, provided the trees are not invasive or carrying exotic genotypes, and plantations are managed to control weeds and feral animals. With the same caveats, plantations of exotic pines may also be acceptable from a biodiversity conservation perspective in well-forested landscapes. At present our capacity to design and manage rainforest plantations for both timber and biodiversity objectives is limited by a lack of information on factors affecting timber production, biodiversity values and trade offs or synergies between these objectives. Obtaining this information will require the integration of large-scale long-term biodiversity research in broadscale plantation projects