4,943 research outputs found
A numerical model of mesoscale frontal instabilities and plankton dynamics - I. Model formulation and initial experiments
No full textPrevious observational and modelling studies of open ocean frontal regions have found large vertical velocities associated with instabilities on the frontal jet. A combined physical/ecosystem numerical model is used to investigate the impact of jet instability and the associated vertical motions on the local ecosystem. The evolution of the instability of a mesoscale frontal jet gives rise to vertical transport of nutrients into the euphotic zone and subduction of biota out of the euphotic zone. The upwelling of nutrients stimulates increases in primary production, with resulting increases in phytoplankton stocks. The reaction of the ecosystem is found to be dependent on the physical characteristics of the front, but the increase in primary production can be locally of the order of 100%, and of the order of 10% when averaged over the frontal region. The action of upwelling and subduction introduces spatial heterogeneity in primary production and plankton biomass. The heterogeneity is at a variety of length scales, from the order of a few kilometres for thin filaments and up to 50 km for coherent features. With increases in new production occurring over several degrees of latitude, frontal dynamics may make a significant contribution to the strength of the biological pump
Acceleration of global warming due to carbon-cycle feedbacks in a coupled climate model
No full textThe continued increase in the atmospheric concentration of carbon dioxide due to anthropogenic emissions is predicted to lead to significant changes in climate. About half of the current emissions are being absorbed by the ocean and by land ecosystems, but this absorption is sensitive to climate as well as to atmospheric carbon dioxide concentrations, creating a feedback loop. General circulation models have generally excluded the feedback between climate and the biosphere, using static vegetation distributions and CO2 concentrations from simple carbon-cycle models that do not include climate change. Here we present results from a fully coupled, three-dimensional carbon–climate model, indicating that carbon-cycle feedbacks could significantly accelerate climate change over the twenty-first century. We find that under a 'business as usual' scenario, the terrestrial biosphere acts as an overall carbon sink until about 2050, but turns into a source thereafter. By 2100, the ocean uptake rate of 5 Gt C yr-1 is balanced by the terrestrial carbon source, and atmospheric CO2 concentrations are 250 p.p.m.v. higher in our fully coupled simulation than in uncoupled carbon models, resulting in a global-mean warming of 5.5 K, as compared to 4 K without the carbon-cycle feedback
Global fields of sea surface dimethylsulfide predicted from chlorophyll, nutrients and light
No full textRecommended from our members
Climate sensitivity to ocean dimethylsulphide emissions
No full textThe production of dimethylsulphide (DMS) by ocean phytoplankton is hypothesized to form part of a feedback process on global climate. Changes in the DMS flux to the atmosphere cause changes to aerosols for cloud formation, leading to changes in the amount of radiation reaching the ocean, and hence on the planktonic production of DMS. This hypothesis has been investigated using a coupled ocean-atmosphere general circulation model (COAGCM) that includes an ocean ecosystem model and an atmospheric sulphur cycle. Ocean DMS concentrations are parameterised as a function of chlorophyll, nutrient and light. The results of several sensitivity experiments are presented showing significant global climate change responses to perturbations in ocean DMS production. A small negative feedback from climate change onto ocean DMS production is found and the implications are discussed
Dredging Processes I: The Cutting of Sand, Clay & Rock - Theory
No full textThis book gives an overview of cutting theories. It starts with a generic model, which is valid for all types of soil (sand, clay and rock) after which the specifics of dry sand, water saturated sand, clay, rock and hyperbaric rock are covered. For each soil type small blade angles and large blade angles, resulting in a wedge in front of the blade, are discussed. The failure mechanism of sand, dry and water saturated, is the so called Shear Type. The failure mechanism of clay is the so called Flow Type, but under certain circumstances also the Curling Type and the Tear Type are possible. Rock will usually fail in a brittle way. This can be brittle tensile failure, the Tear Type, for small blade angles, but it can also be brittle shear failure, which is of the Shear Type of failure mechanism for larger blade angles. Under hyperbaric conditions rock may also fail in a more ductile way according to the Flow Type of failure mechanism. For each case considered, the equations/model for the cutting forces, power and specific energy are given. The models are verified with laboratory research, mainly at the Delft University of Technology, but also with data from literature.Marine & Transport TechnologyMechanical, Maritime and Materials Engineerin
Work among Japanese in the Salt River Valley of Arizona
No full textDocument written by S.A. Stewart Resident Missionary, East Kyushu Distict, Japan Methodist Church. Stewart discusses the events at the church and the free and restricted zones for Japanese Americans living in Glendale and Phoenix, Arizona.The Bishop James Chamberlain Baker Collection includes letters, documents, and articles about Japanese Americans during World War II. Subjects in the collection include Japanese Americans mass removal, Pearl Harbor and the aftermath, religion, and support from the non-Japanese American community. The collection was digitized and made accessible online by CSUDH Gerth Archives and Special Collections
TP S.A.) (Umowa spoleczna - narzedzie transformacji czy recepta na kryzys? (TP S.A.)
No full textThe author presents the path to the signing of a Social Contract for the years 2009-2011 by all eighteen trade unions active at 'Telekomunikacja Polska S.A. The Contract defines the most important elements of employment policy and worker development, including a plan for the restructuring of the company and voluntary resignation for compensation on the part of the employe
The mining rescure in SRK S.A. – economics and busines
No full textArtykuł podejmuje problematykę ratownictwa górniczego w Polsce w kontekście likwidowanych zakładów górniczych. Na podstawie wybranych przepisów górniczych autor wyjaśnia zasady funkcjonowania ratownictwa przedsiębiorcy i podmiotów zawodowo trudnią-cych się ratownictwem górniczym. Opisuje organizację ratownictwa górniczego w Polsce oraz kompetencje poszczególnych podmiotów w tym zakresie. Przedstawia także etapy tworzenia ratownictwa górniczego w spółce SRK S.A. oraz elementy analizy ekonomicznej związanej z kosztami utrzymania Stacji Ratownictwa Górniczego SRK S.A. Artykuł porusza również problem społeczny związany z próbą przejęcia przez Centralną Stację Ratownictwa Górniczego S.A. w Bytomiu pełni zabezpieczenia w zakresie ratownictwa górniczego 12 oddziałów SRK S.A. w których nadal prowadzone są roboty podziemne. W podsumowaniu autor opisuje paradoksy tego przedsięwzięcia.The article discusses aspect of the mining rescue in Poland in the context of liquidated mining plants. On the basis of selected mining regulations, the principles of the rescue operation of an operator as well as of professional mining rescue workers has been explained. This paper describes the organization of the mining rescue in Poland and the competences of individual entities included in this entity. Described have been also the stages of organizing the mining rescue in SRK S.A. and elements of economic analysis of maintenance costs in SRK S.A. Rescue Station. The article also undertakes the social problem related to the attempted takeover by the Central Mining Rescue Station S.A. in Bytom full security of twelve departments of the mining rescue SRK S.A. where underground works are still being carried out. As a summary the author faces with the paradoxes of this situation
Equity research - Kering S.A.
No full textMestrado em FinançasEquity research a Kering S.A com o intuito de determinar um determinado price target para o valores das acções da Kering S.A a 31 de Dezembro de 2019.
No processo para determinar o price target foram utilizados 3 modelos de avaliação distintos, Discounted Cash Flow Model, Dividend Discount Model e Multiples Valuation dos quais se obteve um price target de 576.44 EUR representando um upside de 8.9% face ao preço base utilizado para esta analise de 520.10 EUR de 1 de Julho de 2019.This project is mainly comprised on an Equity Research of Kering S.A. to determine a certain price target of Kering's stock by 31st December 2019. This assessment is mostly assembled by a set of assumptions, made the author of these document, for the time period of 2019F-2023F which reflect the historical performance of the company and the current market settings that may impact such target price.
In regards of the computations around the price target definition, three valuation models were covered, the Discounted Cash Flow Model, which discounted all future cash flows generated in the period under analysis and through perpetuity, totaling a price of 580.12 EUR / share, and the Dividend Discount Model and Multiples Valuation Model which totaled 567.00 EUR and 582.22 EUR respectively. Based on these there valuation models, by assigning an equal weight to each one of them, a price target of 576.44 EUR was reached translating into a 8.9% upside potential regarding the reference date of analysis of 525.10 EUR in 1st July 2019.
Once, computed the price target, the final recommendation for these equity research document was defined based on the risk criteria that better described Kering S.A market environment settings, providing this way a solid statement for Kering's share price within the period under analysisinfo:eu-repo/semantics/publishedVersio
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