81 research outputs found
Redefining The American Coastline: Can The Government Withdraw Basic Services From The Coast And Avoid Takings Claims?
Herodotus once said “[t]his is the worst pain a man can have: to know much and have no power to act.” The words of Herodotus resonate today in the debate over the habitability of the coast. Despite advances in technology and science, which have provided government and citizens alike with the knowledge of the physical and financial dangers of coastal development, society has lost control over the ability to limit and discourage development in coastal areas that are repeatedly subject to disaster. The cavalier and defiant spirit of American culture has led us to encourage and subsidize growth at the foot of our own Mount Vesuvius thereby leading to a perpetual reenactment of the same disaster. Hurricanes, floods, and coastal erosion are not new phenomena; however, the toll of these natural disasters on humans has been exacerbated by increased development and human habitation along the coast. In essence, coastal communities represent the quintessential conflict between humans and nature. Many local and state governments have sought to promote coastal development as a means to generate economic prosperity by expanding the tax base and increasing employment opportunities. Both the governments that have promoted such growth and the private citizens that have a proprietary or other financial interest in these areas have an incentive to protect their interests. This translates into harnessing modern technology to preserve coastal property damaged by natural events. Thus, many coastal communities have a cyclical life existence. First, the coastal community is created. Second, the coastal community is damaged or destroyed by a natural event. Third, the coastal community is reborn as disaster relief is provided and repairs are made. This cyclical pattern—creation, destruction, and repair—embodies the life of many American coastal communities. The resources spent at the federal, state, and local level that contribute to the coastal community lifecycle are staggering. While the federal government spends billions of dollars to fund agencies such as the Federal Emergency Management Agency (FEMA), which runs programs like the National Flood Insurance Program (NFIP), state and local governments are left to cover the shortfalls in federal disaster relief expenditures. This cycle is repeated because in today’s political climate it is considered outrageous to refuse to rebuild a coastal community after a natural event. Imagine the outcry had political leaders decreed that New Orleans would not be rebuilt after Hurricane Katrina. This Comment posits that the coastal community lifecycle will be broken in the future as a new coastal community ethic and corresponding public policy agenda emerge in response to the effects of climate change and society’s internalization of the costs of rebuilding coastal communities. This ethic will embrace the belief that living along the coast, to a certain extent, is an individual choice and that the costs and responsibilities associated with that choice should be borne by the individual rather than the government. Moreover, this Comment explores the ways in which a new coastal community ethic will redefine the American coastline, asserting that one approach governments may use to minimize coastal costs is to withdraw basic services like utilities and road repair projects from coastal communities. The question that then arises is whether the government can change its public policy for free. If the government refused to rebuild a coastal community’s infrastructure would property owners be entitled to compensation for a “taking” of their property under either the Fifth or Fourteenth Amendments? After analyzing landowners’ takings claims, this Comment concludes that the government can change its coastal community public policy without compensating landowners. The legal explanation, however, may differ from the political one. Part I of this Comment provides a brief historical overview of coastal property damage, describes the financial costs associated with natural disasters along the coastline, and discusses the extent of coastal development in the United States. Part II explains the major causes that have led to explosive coastal development, including perceived technological advances in protecting coastal property and social policies such as the National Flood Insurance Program. Part III discusses the factors that may change the traditional coastal community lifecycle, such as climate change and the internalization of costs associated with maintaining coastal communities. Part IV explores whether the government could withdraw basic services from the coast and refuse to rebuild damaged infrastructure without compensating landowners. Although the government may not have to compensate landowners with legal damages, it would likely have to appropriate funds to garner political support for this policy change. Part V concludes that the government’s refusal to rebuild coastal communities’ infrastructure is a powerful, economically efficient tool that could be used to reshape the American coastline
Extending electron orbital precession to the molecular case: Can orbital alignment be used to observe wavepacket dynamics?
The complexity of ultrafast molecular photoionization presents an obstacle to
the modelling of pump-probe experiments. Here, a simple optimized model of
atomic rubidium is combined with a molecular dynamics model to predict
quantitatively the results of a pump-probe experiment in which long range
rubidium dimers are first excited, then ionized after a variable delay. The
method is illustrated by the outline of two proposed feasible experiments and
the calculation of their outcomes. Both of these proposals use Feshbach 87Rb2
molecules. We show that long-range molecular pump-probe experiments should
observe spin-orbit precession given a suitable pump-pulse, and that the
associated high-frequency beat signal in the ionization probability decays
after a few tens of picoseconds. If the molecule was to be excited to only a
single fine structure state state, then a low-frequency oscillation in the
internuclear separation would be detectable through the timedependent
ionization cross section, giving a mechanism that would enable observation of
coherent vibrational motion in this molecule.Comment: 9 pages, 10 figures, PRA submissio
Evaluation of Deformable Boundary Condition Using Finite Element Method and Impact Test for Steel Tubes
Stainless steel pipelines are crucial components to transportation and storage in the oil and gas industry. However, the rise of random attacks and vandalism on these pipes for their valuable transport has led to more security and protection for incoming surface impacts. These surface impacts can lead to large global deformations of the pipe and place the pipe under strain, causing the eventual failure of the pipeline. Therefore, understanding how these surface impact loads affect the pipes is vital to improving the pipes’ security and protection. In this study, experimental test and finite element analysis (FEA) have been carried out on EN3B stainless steel specimens to study the impact behaviour. Low velocity impact tests at 9 m/s with 16 kg dome impactor was used to simulate for high momentum impact for localised failure. FEA models of clamped and deformable boundaries were modelled to study the effect of the boundaries on the pipes impact behaviour on its impact resistance, using experimental and FEA approach. Comparison of experimental and FE simulation shows good correlation to the deformable boundaries in order to validate the robustness of the FE model to be implemented in pipe models with complex anisotropic structure
A pump-probe study of the formation of rubidium molecules by ultrafast photoassociation of ultracold atoms
An experimental pump-probe study of the photoassociative creation of
translationally ultracold rubidium molecules is presented together with
numerical simulations of the process. The formation of loosely bound
excited-state dimers is observed as a first step towards a fully coherent
pump-dump approach to the stabilization of Rb into its lowest ground
vibrational states. The population that contributes to the pump-probe process
is characterized and found to be distinct from a background population of
pre-associated molecules.Comment: Accepted for publication in Phys. Rev. A (10 pages, 9 figures
Demonstrating coherent control in 85Rb2 using ultrafast laser pulses: a theoretical outline of two experiments
Calculations relating to two experiments that demonstrate coherent control of
preformed rubidium-85 molecules in a magneto-optical trap using ultrafast laser
pulses are presented. In the first experiment, it is shown that pre-associated
molecules in an incoherent mixture of states can be made to oscillate
coherently using a single ultrafast pulse. A mechanism that can transfer
molecular population to more deeply bound vibrational levels is used in the
second. Optimal parameters of the control pulse are presented for the
application of the mechanism to molecules in a magneto-optical trap. The
calculations make use of an experimental determination of the initial state of
molecules photoassociated by the trapping lasers in the magneto-optical trap
and use shaped pulses consistent with a standard ultrafast laser system.Comment: 8 pages, 9 figures, PRA, 80, 033403 (2009
BICCO-Net II. Final report to the Biological Impacts of Climate Change Observation Network (BICCO-Net) Steering Group
• BICCO-Net Phase II presents the most comprehensive single assessment of climate change impacts on UK biodiversity to date.
• The results provide a valuable resource for the CCRA 2018, future LWEC report cards, the National Adaptation Programme and other policy-relevant initiatives linked to climate change impacts on biodiversity
Impacts of climate change on national biodiversity population trends
Climate change has had well-documented impacts on the distribution and phenology of species across many taxa, but impacts on species’ abundance, which relates closely to extinction risk and ecosystem function, have not been assessed across taxa. In the most comprehensive multi-taxa comparison to date, we modelled variation in national population indices of 501 mammal, bird, aphid, butterfly and moth species as a function of annual variation in weather variables, which through time allowed us to identify a component of species’ population growth that can be associated with post-1970s climate trends. We found evidence that these climate trends have significantly affected population trends of 15.8% of species, including eight with extreme (> 30% decline per decade) negative trends consistent with detrimental impacts of climate change. The modelled effect of climate change could explain 48% of the significant across-species population decline in moths and 63% of the population increase in winged aphids. The other taxa did not have significant across-species population trends or consistent climate change responses. Population declines in species of conservation concern were linked to both climatic and non-climatic factors respectively accounting for 42 and 58% of the decline. Evident differential impacts of climate change between trophic levels may signal the potential for future ecosystem disruption. Climate change has therefore already driven large-scale population changes of some species, had significant impacts on the overall abundance of some key invertebrate groups and may already have altered biological communities and ecosystems in Great Britain
Anthropogenic climate and land-use change drive short- and long-term biodiversity shifts across taxa
Climate change and habitat loss present serious threats to nature. Yet, due to a lack of historical land-use data, the potential for land-use change and baseline land-use conditions to interact with a changing climate to affect biodiversity remains largely unknown. Here, we use historical land use, climate data and species observation data to investigate the patterns and causes of biodiversity change in Great Britain. We show that anthropogenic climate change and land conversion have broadly led to increased richness, biotic homogenization and warmer-adapted communities of British birds, butterflies and plants over the long term (50+ years) and short term (20 years). Biodiversity change was found to be largely determined by baseline environmental conditions of land use and climate, especially over shorter timescales, suggesting that biodiversity change in recent periods could reflect an inertia derived from past environmental changes. Climate–land-use interactions were mostly related to long-term change in species richness and beta diversity across taxa. Semi-natural grasslands (in a broad sense, including meadows, pastures, lowland and upland heathlands and open wetlands) were associated with lower rates of biodiversity change, while their contribution to national-level biodiversity doubled over the long term. Our findings highlight the need to protect and restore natural and semi-natural habitats, alongside a fuller consideration of individual species’ requirements beyond simple measures of species richness in biodiversity management and policy
A preliminary modelling investigation into the safe correction zone for high tibial osteotomy
Purpose: High tibial osteotomy (HTO) re-aligns the weight-bearing axis (WBA) of the lower limb. The surgery reduces medial load (reducing pain and slowing progression of cartilage damage) while avoiding overloading the lateral compartment. The optimal correction has not been established. This study investigated how different WBA re-alignments affected load distribu- tion in the knee, to consider the optimal post-surgery re-alignment. Methods: We collected motion analysis and 7T MRI data from 3 healthy sub- jects, and combined this data to create sets of subject-specific finite element models (total=45 models). Each set of models simulated a range of potential post-HTO knee re-alignments. We shifted the WBA from its native align- ment to between 40% and 80% medial-lateral tibial width (corresponding to 2.8â—¦-3.1â—¦ varus and 8.5â—¦-9.3â—¦ valgus), in 3% increments. We then compared stress/pressure distributions in the models. Results/Discussion: Correcting the WBA to 50% tibial width (0â—¦ varus- valgus) approximately halved medial compartment stresses, with minimal changes to lateral stress levels, but provided little margin for error in under- correction. Correcting the WBA to a more commonly-used 62%-65% tibial width (3.4â—¦-4.6â—¦ valgus) further reduced medial stresses but introduced the danger of damaging lateral compartment tissues. To balance optimal loading environment with that of the historical risk of under-correction, we propose a new target: WBA correction to 55% tibial width (1.7â—¦-1.9â—¦ valgus), which anatomically represented the apex of the lateral tibial spine. Conclusions: Finite element models can successfully simulate a variety of HTO re-alignments. Correcting the WBA to 55% tibial width (1.7â—¦-1.9â—¦ valgus) optimally distributes medial and lateral stresses/pressures
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