Original Topography Research Articles

Mesh Generation for Arch Dam Abutment Slip Block Based on Virtual Grid

Abstract. In order to generate mesh for arch dam abutment slip block automatically, virtual grid method is proposed based on grid-based automatic generation algorithm. The proposed algorithm avoids generating initial grid in one time, but intersects the model with a series of plane sections firstly. Then form initial grid by using vector intersection method for adjacent sections. By modifying initial grid, a layer of mesh is formed. The algorithm proposed can better adapt to complex topography and generates hexahedral meshes for the block of arch dam abutment automatically. The method can present data for limit equilibrium analysis and numerical calculation method such as finite element method. Based on original topography and structural plane data, the automatic identification, generation and meshing of arch dam abutment block is accomplished.

The post-orogenic evolution of the Northeast Greenland Caledonides constrained from apatite fission track analysis and inverse geodynamic modelling

We present new apatite fission track (AFT) data from the Northeast Greenland passive margin, between 75.8 and 81°N, where elevations reach over 1000m and no signs of magmatism related to the opening of the North Atlantic exist. The AFT ages are old, ranging from just less than 200Ma up to more than 350Ma, and the length distributions are predominantly narrow unimodal, with c-axis projected mean track lengths between 13.3 and 15.0μm. The passive margin of Northeast Greenland differs from other studied passive margins in terms of AFT age trends, as we observe no correlation with elevation or characteristic trends relative to mean track length.Using these new data and inverse geodynamic modelling, we constrain the evolution in the area since the orogenic collapse of the Caledonides. Exhumation histories are inferred using a uniform stretching model, incorporating variable rates of erosion or deposition, and thermal histories are found by solving the one-dimensional transient conduction–advection heat equation. These thermal histories are used with the observed fission track data to constrain acceptable strain rate histories and exhumation paths.The results suggest that rifting has been focused mainly in the now offshore regions since ~300Ma, or in minor local areas onshore, not affecting the sampled areas significantly. The present-day high topography is therefore suggested simply to represent remnants of the original Caledonian topography, modified during early rifting and, other than the flexural isostatic response to erosional unloading, we find no need for introducing post-rift related uplift mechanisms.

Surface Mining Technology: Progress and Prospects

Surface mining methods dominate the world production of minerals. Currently, almost all non-metallic minerals [more than 95%], most metallic minerals [more than 90%] and a large fraction of coal [more than 60 percent] are mined by surface methods. Of the over 30 billion tonnes of ore and waste materials that are mined each year, surface mining accounts for nearly 25 billion tonnes. The subsurface of the earth is the only source for fossil energy and mineral products, and mining is the only way to get at them. There is a wide variety of surface mining methods. The operations of drilling, blasting, loading and hauling are common to most methods. Technological developments over the years have enabled the application of surface methods to deeper and leaner deposits. Also common to all methods is the removal of the surface cover over the deposit, the changes to the original topography, the effects on soil and hydrologic conditions, the issues of mining and processing wastes, and the effect on the future economic potential of the mined areas and communities. However, the scope of the issues and the potential solutions to the issues vary widely and are often site-specific. While research and development are needed to address technical aspects associated with these issues, innovative policies for addressing the overall problem of environmental and ecological planning for post-mining development on lands with mineral resources are needed. In the last two decades, the mining industry has seen consolidation of operating companies, growth in the size of individual operations, increase in size of equipment, and greater demands for sustainable development. These trends would continue into the future impacting both the opening of new mines and the closure of existing operations. In this paper, an overview of surface mining technology is presented. The discussion follows the mineral development cycle and concludes with an identification of future research needs.

Quality assessment of the registration of vulvar and vaginal premalignant lesions at the Cancer Registry of Norway

Background. A crucial factor concerning the utility of Cancer Registries is the data quality with respect to comparability, completeness, validity and timeliness. However, the data quality of the registration of premalignant lesions has rarely been addressed. High grade vulvar intraepithelial neoplasia (VIN) and vaginal intraepithelial neoplasia (VaIN) are premalignant lesions which may develop into cancer, and are often associated with infection with the human papillomarvirus (HPV). The aim was to evaluate the quality of registration of VIN and VaIN at the Cancer Registry of Norway (CRN). Material and methods. We re-collected all notifications with high grade VIN and VaIN diagnoses during 2002 to 2007 from pathology laboratories, and compared these to the data in the CRN database so as to quantitatively measure the completeness, validity and timeliness of the data. Results. Over the period 2002 to 2007 we estimated the completeness of the 1556 VIN and 297 VaIN notifications to be 95.0% and 92.9%, respectively. The original and reabstracted topography codes showed major discrepancies for 12 of 642 (1.9%) VIN and 7 of 128 (5.5%) VaIN notifications. The original and reabstracted morphology codes for VIN and VaIN were identical for 724 out of 814 notifications. Sixteen notifications had a major discrepancy. For the period 2002 to 2007 the median time elapsed between date of diagnosis and date of registration were 436 and 441 days for VIN and VaIN cases, respectively. Discussion. Based on the present analysis of the comparability, completeness, validity and timeliness of premalignant lesions of vulva and vagina, we conclude that the Cancer Registry of Norway is able to monitor such premalignant lesions satisfactorily.

Surface Characterization of Replicate Wood Surfaces for Cleaning Studies

Abstract A need exists to develop realistic surfaces, with differing degrees of surface roughness, to standardize methods for sampling and cleaning of environmental contaminants. This study reports on development and characterization of a novel means to create reproducible wood surfaces that are approximately 7 × 10 cm2 and have differing degree of surface roughness. Three unique specimens were prepared by creating 3-dimensional digital-scans of actual wood surfaces found in three St. Louis homes. These surfaces had distinct depressions that likely arose from tool marks. A reverse image die of each specimen was made from high density plastic. Replicates of the three specimens were created by placing a die and wood veneer section into a rolling-press leaving the original topographies gathered from the homes. These specimens were used in a separate study to evaluate cleaning leaded dust using wipe or vacuuming treatments. The separate cleaning studies found no difference in cleaning due to the effects of the different surfaces. An in-depth examination of the three specimens was held to determine if differences in surface roughness of the specimens explained removal of lead from its surface. A method using optical, 3-D laser profilometry was used to determine if there were statistical differences between the surface roughness of the three specimens and within the specimens themselves. Area-scale analyses were made to calculate relative areas as a function of scale as a way of characterizing the roughness. Statistical differences were found for surface roughness between each of three surface specimens at a scale where small particles, deposited in the cleaning studies may adhere to the wood. However, within the specimens, surface roughness, at the scale where fine particles may lodge, were not consistent inside or outside tool marks. Therefore, differences in surface roughness were found within and between surfaces but they may not be large enough or different enough for detection using simple cleaning methods. Specimens with larger differences in surface roughness may be needed to simulate differences in cleaning effectiveness. This work should be continued to understand the scales for the different interactions of particle deposition, adhesion, and removal toward development of standard reference surfaces with well-characterized textures.

A Hybrid System-Level Modeling and Simulation Methodology for Structurally Complex Microelectromechanical Systems

We present a hybrid system-level modeling and simulation methodology by combining numerical macromodels with parameterized lumped-element behavioral models for structurally complex microelectromechanical systems (MEMS). We decompose the MEMS into several functional components. For those components with complex geometry and boundary conditions, we model them using numerical macromodels, whereas for those with simple geometry, we model them using parameterized lumped-element behavioral models. Both models are represented by the same syntax and similar equation forms to ensure the compatibility. Afterward, the hybrid numerical macromodels and parameterized behavioral models are inserted into the same simulator and then interconnected to each other according to the original topography of the MEMS for system-level simulation. As one of the key technologies of the proposed methodology, macromodeling has been improved in two aspects. First, macromodeling for the component with dynamic boundary condition is achieved by combining modal analysis with a novel iterated improved reduced system method. Second, angular parameterization for the components with the same geometry but different initial orientation is achieved by the matrix coordinate transformation. A z-axis micromachined gyroscope is used to demonstrate the proposed methodology. Simulation results show that the method can efficiently support the design for structurally complex MEMS.

Complex microtopography analysis in sliding friction of steel-ferodo material pair

The tribological behaviour—friction, wear and lubrication—of machine elements highly depends on the operating state and also on the original topography of the working pair. Wear tests and 3D surface roughness measurements were carried out to analyse the effect of surface topography in friction and wear between ground steel specimens of various machining directions and different surface quality levels and a ferodo sliding pair. Three different techniques were used for surface topography evaluation: a parameter-based technique, a slicing method, and power spectral density analysis. Several parameters were found to be sensitive to surface wear phenomena; their changes indicate, among other things, surface platoing or the appearance of dominant scratches. The peak angle and height of asperities convey important information on numerous tribological changes. Power spectral density (PSD) analysis shows that the result of changes in the topography is an ‘equilibrium’ surface.

HISTORICAL TRANSITION OF RIVER TRAINING WORKS AND INUNDATION CHARACTERISTICS IN SAPPORO

The urbanization in Sapporo was started about only 140 years ago. Before the urbanization, the topography of most part of Sapporo was wetland and not suitable for living and cultivation. Intensive river training works have changed this area dramatically for relatively short period, and made Sapporo as one of the biggest cities in Japan with a population of 1.9 million. In this study, the history of river training works and the transition of inundation characteristics in Sapporo are investigated through old literatures and numerical simulations. First, the historical process of river training constructions was clarified by inspecting old documents and found out some key works. Then numerical simulations of flood were performed in three cases, namely, original topography, after construction of Toyohira-River- Bank and after construction of new Toyohira River Channel. The comparison of simulation results elucidated the relation between river training works and change of inundation behavior.

Symmetrical Cone-Shaped Hills, Abaco Island, Bahamas: Karst or Pseudokarst?

2 Abstract: Abaco Island, Bahamas, contains a large number of conical hills that strongly resemble cone karst, a dissolutional landform associated with karst processes in tropical carbonate localities around the world. Field investigation demonstrated that the conical hills are roughly symmetrical in shape and consist of mid to late Pleistocene eolian calcarenites (carbonate sand dunes) partly mantled by talus. The original hummocky depositional topography of the eolian ridges has been dissected by a variety of processes including dissolution pit formation that enhances slope failure, vegetative disruption of the rock surface, and fire-induced exfoliation of the bedrock. The original asymmetrical shape of continuous dune ridges has thus been modified into a series of hills with a symmetrical cone shape, in which the steeper leeward depositional slopes of the dunes have been masked by talus to create a lesser slope that approximates the dip of the exposed bedrock slope of the more gentle windward depositional faces of the dunes. The conical hills are primarily constructional in nature, modified by mass-wasting slope processes only partly influenced by dissolution; therefore these conical hills are not true cone karst, but pseudokarst, despite their cone shape and their development in soluble carbonate rock. Abaco is the only island in the Bahamian Archipelago with both high eolian relief and a significant positive water budget; that water budget supports the degree of dissolution and forest growth necessary to create the root wedging and fire- induced exfoliation that most modify the steep leeward slopes of the dunes. As the eolian calcarenites were deposited only during the brief glacioeustatic sea-level highstands of the last few hundred thousand years, the development of cone-shaped hills in these eogenetic rocks has been geologically very rapid.

A Quasi-Static Mechanics Analysis of Three-Dimensional Nanoscale Surface Polishing

A quasi-static mechanics analysis of nanoscale surface polishing that provides insight into the surface topography evolution and the removal of material at the asperity level is presented. The analysis is based on a three-dimensional stochastic model that accounts for multiscale (fractal) surface roughness and elastic, elastic-plastic, and fully plastic asperity deformation by hard abrasive nanoparticles embedded in the soft surface layer of a rigid polishing plate. Numerical results of the steady-state roughness of the polished surface, material removal rate, and wear coefficient are presented in terms of the apparent contact pressure, polishing speed, original topography and mechanical properties of the polished surface, average size and density of nanoparticles, and surface roughness of the polishing plate. Simulation trends are associated with elastic-plastic and fully plastic asperity contacts, responsible for irreversible topography changes (roughening effect) and material removal (smoothening effect), respectively. Analytical trends and predictions of the steady-state roughness of the polished surface and material removal rate are shown to be in good agreement with experimental results of nanoscale surface polishing (lapping) of magnetic recording ceramic heads.

Restoring earth surface processes through landform design. A 13‐year monitoring of a geomorphic reclamation model for quarries on slopes

AbstractThe application of geomorphic principles to land reclamation after surface mining has been reported in the literature since the mid‐1990s, mostly from Australia, Canada and the USA. This paper discusses the reclamation problems of contour mining and quarries on slopes, where steep gradients are prone to both mass movement and water erosion. To address these problems simultaneously, a geomorphic model for reclaiming surface mined slopes is described. Called the ‘highwall–trench–concave slope’ model, it was first applied in the 1995 reclamation of a quarry on a slope (La Revilla) in Central Spain.The geomorphic model does not reproduce the original topography, but has two very different sectors and objectives: (i) the highwall–trench sector allows the former quarry face to evolve naturally by erosion, accommodating fallen debris by means of a trench constructed at the toe of the highwall; (ii) the concave‐slope base sector, mimicking the landforms of the surrounding undisturbed landscape, promotes soil formation and the establishment of self‐sustaining, functional ecosystems in the area protected from sedimentation by the trench. The model improves upon simple topographic reconstruction, because it rebuilds the surficial geology architecture and facilitates re‐establishment of equilibrium slopes through the management and control of geomorphic processes.Thirteen years of monitoring of the geomorphic and edaphic evolution of La Revilla reclaimed quarry confirms that the area is functioning as intended: the highwall is backwasting and material is accumulating at the trench, permitting the recovery of soils and vegetation on the concave slope. However, the trench is filling faster than planned, which may lead to run‐off and sedimentation on the concave slope once the trench is full. The lesson learned for other scenarios is that the model works well in a two‐dimensional scheme, but requires a three‐dimensional drainage management, breaking the reclaimed area into several watersheds with stream channels. Copyright © 2010 John Wiley & Sons, Ltd.

Análise Qualitativa do Assoreamento do Reservatório de Promissão (SP)

Siltation of reservoirs formed by dam building is inevitable, and the consequences of this process are lessened by knowledge of the process dynamics and the implementation of corrective and preventive control measures. In this research the siltation of Promissao Reservoir (located in Middle Tiete watershed) was investigated. Analysis of the siltation process was based on changes in the reservoir bottom level by comparing the original lake topography during the reservoir filling period in 1975, with the topobathymetry obtained in 2005. The results showed the degree of siltation of the compartments studied, as well as the sediment location, within or outside the active volume. The main body of the reservoir was little affected by siltation and among the most important reservoir tributaries, the Porcos River and Batalha River were the most affected. Other less important tributaries were fully silted up or had a high degree of siltation, with the largest share of sediment deposited in the active volume compartment. The qualitative analysis of silting data was effective to determine the stage of siltation in the tributaries and in the main body of Promissao Reservoir

Fluence Effects in C60 Cluster Bombardment of Silicon

In this theoretical investigation, we combine the results of molecular dynamics (MD) simulations with a simple statistical sputtering model (SSM) in order to understand the factors limiting the optimum depth resolution achievable in sputter depth profiling experiments. The advantage of the SSM model is that it can be used to extrapolate the MD simulations toward the regime of high projectile fluence. First, a recently developed scheme [Russo, M. F., Jr.; Postawa, Z.; Garrison, B. J., J. Phys. Chem. C 2009, 113, 3270] is adapted to calculate 200 cumulative impacts of 20-keV C60 bombardment on a Si substrate, which corresponds to a projectile fluence of 3.5 × 1013 cm−2. The following results are studied as a function of fluence: the development of surface topography, the amount and depth of origin of sputtered material, and the relocation of substrate particles, which produces interlayer mixing. Data from the MD simulations are used as input parameters in the SSM, which is able to reproduce results consiste...

Anterior interbody metal-ceramic spondylodesis in diseases and injuries of the cervical spine

A clinical application of a new technology of monosegmental and bisegmental anterior interbody metal-ceramic spondylodesis with help of cervical plates, which have an original topography of their contact surface, and porous aluminum-oxide ceramic implants was analysed for surgical treatment of diseases and injuries of the cervical spine. The above technology is highly effective and makes it possible to achieve positive clinical effects, normal sagittal craniocervical balance and reconstruction of the cervical sagittal contour.

How Many Years Can a Mountain Exist before it's Washed to the Sea? Or, Bob Dylan's Theory of Landscape Evolution

The question of the persistence of topography is not just a line in one of the most famous songs ever written, it is also one of the long-standing questions in geomorphology. Mountains created by tectonic processes hundreds of millions of years ago still stand proud in the landscape, posing intriguing questions of how topography can persist for such a long time, and if the mountains we see today are the result of more recent processes, and therefore not a direct relict of the original topography. Although models have been proposed to explain the antiquity of topography, the only way to test these models is by providing denudation rates over millions of year time scales. Such data can be uniquely provided by low temperature thermochronometers. In this paper we provide a brief review of these techniques and an example from western Scotland where the thermochronometers have been applied to determine the age of first order topography. The results indicate that although denudation rates have been temporally and spatially variable in the last ∼300 Ma, the macro-topography has not changed significantly.

Melancholy, Topography and the Search for Origin in Ingeborg Bachmann's Drei Wege Zum See

ABSTRACTBachmann's Drei Wege zum See is a text insistently preoccupied with questions of identity, origin and origination. Operating along a topographical structure that both frames and drives the narrative, its concern is a walking through personal and collective history in search of an elusive point of origin. This attempt is always necessarily melancholic, standing under the perennial threat of missed or failed homecomings. Using psychoanalytic conceptions of psychic topography and Walter Benjamin's conception of origin, this essay explores the intersections of memory, place and identity in Drei Wege zum See, as well as drawing on related theories of melancholy and nostalgia. The present article builds on previous explorations of identity, intertextuality and collective memory in Drei Wege zum See, shedding a new light on these through consideration of the text's psychotopographical preoccupation. I explore how an attempt to reconstruct a personal narrative with the aid of a topographical frame is one that will always resist totalisation, where reconstruction may only ever be partial, never complete. Finally, I argue that topographical melancholy is a highly productive mode of identity formation, serving to subvert and overturn falsifying constructions of personal and collective identity.

初期公団住宅の団地に内在する自然環境の構造とその発現形態

Primary purpose of this paper is to show how the regional structure of natural environment was integrated into planning and design of open spaces through the process of land development for collective housing in hilly areas of suburban districts. A case study was made in Tsurumai district of Nara City that was developed in mid 1960s. Extensive research in land formation process and its results based on the information generated by overlaying grading plans upon the original topography indicates the following points. (1) land formation in the housing site followed basic structure of the original micro topography and generated variety of land form which was identified as a fractal elements found in the regional structures of natural environment. (2) The variety of land forms provided spaces for parks, pedestrian spaces, parking lots and other public facilities, and altogether they support the entire system of spatial organization in the housing site. Also, by a comparative study of existing vegetation and those of the original planting plan, it was indicated that environmental stock represented by existing vegetation was developed mostly in the spaces generated by the land formation process in the site.

自然環境の構造に基づく千里ニュータウン公園緑地系統再編の方向性

Since fundamental structures of natural environment had not been altered deeply throughout the development process of Senri New Town, some segments of those structures are still underlying in open spaces including most urban parks of the area. Detailed research into the procedures of land formation in initial development process indicates that area and volume of earthworks were kept minimum based on the original topographical conditions, and as a result, hydraulic system of the area was preserved. These conditions affect planning of the parks, and the areas that contain the original landform and vegetation were located according to the land formation. Also, some athletic grounds in the parks were placed in the area where irrigation ponds were encroached nearby the original topography and vegetation. Based on those notions, the following points are acknowledged as proposals for restructuring open space system in the area for future. (1) Parks and open spaces should be restored in the way to preserve and enhance the regional hydraulic system, which has an indispensable value in the environment. (2) Land use pattern should be reorganized through the renewal process of collective housing sites including conversion of substantial area to open space. (3) Natural environment of the areas designated to athletic grounds by encroaching irrigation ponds should be revitalized through integrating water features of various kinds into functions of the existing parks.

Chemical Functionalization of Water-etched Si(100)

AbstractEtching of hydrogen-terminated Si(100) in deoxygenated water produces surfaces with a regular nanoscale topography. Surface infrared spectroscopy provides detailed information about this topography via interrogation of the silicon hydride species that populate this highly ordered surface. Here we investigate the feasibility of using siloxane chemistry to functionalize this surface while preserving the initial topography. The critical step in silanization to form high-quality organic layers is oxidative cleaning of the surface. By re-etching oxidized surfaces in hydrofluoric acid, we can repopulate surface hydride species and examine any apparent changes in topography that resulted from the oxidation step. We compare three different oxidation protocols and find that an SC-2 clean results in the least perturbation of the original topography. Preliminary results using both dynamic contact angle and atomic force microscopy suggest that the SC-2 oxidized surface can be functionalized with alkylsilane reagents to create a functionalized surface with regular, nanoscale topography, with all surface processing carried out under ambient conditions at or near room temperature.

Environmental aspects of rehabilitating abandoned quarries: Israel as a case study

Quarries that are left untreated after closure cause extensive land disturbances and have negative safety and environmental impacts. The original ecosystems have been removed, the original topography has been significantly changed, the fundamental ecological relations are irreversibly disrupted, and the biodiversity is greatly reduced. This research focuses on the environmental aspects of rehabilitating abandoned quarries and their future designation land use, emphasizing the theme of abandoned quarries in Israel. Quarry rehabilitation legislation guidelines obligate implementation of reclamation but, unfortunately, these have proven to be ineffective. The purpose of this current research was to locate abandoned quarries according to Israeli Comprehensive National Outline Plan for Planning, Building and Conservation, and to determine the best future land use of the abandoned quarries as open spaces or as developmental projects. The research findings show that more abandoned quarries are located in areas designated for conservation than in areas intended for development projects. Therefore, abandoned quarries that are located in conservation areas should be rehabilitated as open spaces. Those in urban and rural areas should be rehabilitated as development projects, or as open spaces and agricultural land uses, or as combined land uses.