76 resultados para Offsetting
Resumo:
Carbon offsetting can be loosely characterized as a mechanism by which an organization or individual contributes to a scheme that is projected either to remove carbon dioxide from the atmosphere or to deliver carbon dioxide emission reductions on the part of other organizations or individuals. An activity that has been offset therefore purports to make no long-term net contribution to atmospheric greenhouse gas concentrations. The ethical basis for using carbon offsetting as an approach to tackling climate change is very much contested. We seek to expose some of the underlying reasons for these ethical disagreements. We show that they relate both to empirical disagreements about what the likely benefits of offsetting are and, more fundamentally, to principled disagreements about the right way to discharge duties to deliver carbon reductions.
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Biodiversity offsets have emerged as one of the most prominent policy approaches to align economic development with nature protection across many jurisdictions, including the European Union. Given the increased level of scrutiny that needs to be applied when authorizing economic developments near protected Natura 2000 sites, the incorporation of onsite biodiversity offsets in project design has grown increasingly popular in some member states, such as the Netherlands and Belgium. Under this approach, the negative effects of developments are outbalanced by restoration programs that are functionally linked to the infrastructure projects. However, although taking into consideration that the positive effects of onsite restoration measures leads to more leeway for harmful project development, the EU Court of Justice has recently dismissed the latter approaches for going against the preventative underpinnings of the EU Habitats Directive. Also, the expected beneficial outcomes of the restoration efforts are uncertain and thus cannot be relied upon in an ecological assessment under Article 6(3) of the Habitats Directive. Although biodiversity offsets can still be relied upon whenever application is being made of the derogation clause under Article 6(4) of the Habitats Directive, they cannot be used as mitigation under the generic decision-making process for plans and programs liable to adversely affect Natura 2000 sites. We outline the main arguments pro and contra the stance of the EU Court of Justice with regards to the exact delineation between mitigation and compensation. The analysis is also framed in the ongoing debate on the effectiveness of the EU nature directives. Although ostensibly rigid, it is argued that the recent case-law developments are in line with the main principles underpinning biodiversity offsetting. Opening the door for biodiversity offsetting under the Habitats Directive will certainly not reverse the predicament of the EU’s biodiversity. A reinforcement of the preventative approach is instrumental to avert a further biodiversity loss within the European Union, even if it will lead to additional permit refusals for unsustainable project developments.
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An assessment of the changes in the distribution and extent of mangroves within Moreton Bay, southeast Queensland, Australia, was carried out. Two assessment methods were evaluated: spatial and temporal pattern metrics analysis, and change detection analysis. Currently, about 15,000 ha of mangroves are present in Moreton Bay. These mangroves are important ecosystems, but are subject to disturbance from a number of sources. Over the past 25 years, there has been a loss of more than 3800 ha, as a result of natural losses and mangrove clearing (e.g. for urban and industrial development, agriculture and aquaculture). However, areas of new mangroves have become established over the same time period, offsetting these losses to create a net loss of about 200 ha. These new mangroves have mainly appeared in the southern bay region and the bay islands, particularly on the landward edge of existing mangroves. In addition, spatial patterns and species composition of mangrove patches have changed. The pattern metrics analysis provided an overview of mangrove distribution and change in the form of single metric values, while the change detection analysis gave a more detailed and spatially explicit description of change. An analysis of the effects of spatial scales on the pattern metrics indicated that they were relatively insensitive to scale at spatial resolutions less than 50 m, but that most metrics became sensitive at coarser resolutions, a finding which has implications for mapping of mangroves based on remotely sensed data. (C) 2003 Elsevier Science B.V. All rights reserved.
Resumo:
Recent theoretical work in economic geography has shown that agglomeration forces can mitigate 'race-to-the-bottom' tax competition, by partly or fully offsetting firms' sensitivity to tax differentials. We test this proposition using data on firm births across Swiss municipalities. We find that corporate taxes deter firm births less in more spatially concentrated sectors. Firms in sectors with an agglomeration intensity in the top quintile are less than half as responsive to differences in corporate tax burdens as firms in sectors with an agglomeration intensity in the bottom quintile. Hence, agglomeration economies do appear to attenuate the impact of tax differentials on firms' location choices.
Resumo:
Within local-spin-density functional theory, we have investigated the ¿dissociation¿ of few-electron circular vertical semiconductor double quantum ring artificial molecules at zero magnetic field as a function of interring distance. In a first step, the molecules are constituted by two identical quantum rings. When the rings are quantum mechanically strongly coupled, the electronic states are substantially delocalized, and the addition energy spectra of the artificial molecule resemble those of a single quantum ring in the few-electron limit. When the rings are quantum mechanically weakly coupled, the electronic states in the molecule are substantially localized in one ring or the other, although the rings can be electrostatically coupled. The effect of a slight mismatch introduced in the molecules from nominally identical quantum wells, or from changes in the inner radius of the constituent rings, induces localization by offsetting the energy levels in the quantum rings. This plays a crucial role in the appearance of the addition spectra as a function of coupling strength particularly in the weak coupling limit.
Resumo:
We investigate the dissociation of few-electron circular vertical semiconductor double quantum dot artificial molecules at 0 T as a function of interdot distance. A slight mismatch introduced in the fabrication of the artificial molecules from nominally identical constituent quantum wells induces localization by offsetting the energy levels in the quantum dots by up to 2 meV, and this plays a crucial role in the appearance of the addition energy spectra as a function of coupling strength particularly in the weak coupling limit.
Resumo:
Why do public-sector workers receive so much of their compensation in the formof pensions and other benefits? This paper presents a political economy model inwhich politicians compete for taxpayers' and government employees' votes by promising compensation packages, but some voters cannot evaluate every aspect of promisedcompensation. If pension packages are "shrouded", so that public-sector workers better understand their value than ordinary taxpayers, then compensation will be highlyback-loaded. In equilibrium, the welfare of public-sector workers could be improved,holding total public-sector costs constant, if they received higher wages and lowerpensions. Centralizing pension determination has two offsetting effects on generosity:more state-level media attention helps taxpayers better understand pension costs, andthat reduces pension generosity; but a larger share of public-sector workers will votewithin the jurisdiction, which increases pension generosity. A short discussion of pensions in two decentralized states (California and Pennsylvania) and two centralizedstates (Massachusetts and Ohio) suggests that centralization appears to have modestlyreduced pensions, but, as the model suggests, this is unlikely to be universal.
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[cat] Les normes socials han estat incloses en la teoria de l’acció col.lectiva per a superar les dificultats per explicar perquè la gestió del béns comuns podria ser més efectiva quan s’autoregula per les mateixes comunitats. El paper rellevant de la confiança en els altres s’ha identificat en diversos contextos d’acció social a nivell local, però només recentment s’ha considerat la idea que també podria ser rellevant en el cas de béns comuns de caire global, seguint l’evidència bàsicament descriptiva recollida per Elinor Ostrom. Però fins ara no hi havia proves quantitatives disponibles d’aquesta idea. Utilitzant un conjunt de dades de 29 països europeus durant el període 1990-2007, donem evidència empírica a favor del paper del nivell de confiança en els altres en el context dels béns públics globals. Concloem que el nivell de confiança en els altres té un impacte reductor de les emissions de gasos d’efecte hivernacle; per exemple, l’extrapolació dels resultats implicaria una reducció d’emissions d’Espanya del 12,5% si el nivell mitjà de confiança en els altres dels espanyols fos tan elevat com els dels suecs.
Resumo:
[cat] Les normes socials han estat incloses en la teoria de l’acció col.lectiva per a superar les dificultats per explicar perquè la gestió del béns comuns podria ser més efectiva quan s’autoregula per les mateixes comunitats. El paper rellevant de la confiança en els altres s’ha identificat en diversos contextos d’acció social a nivell local, però només recentment s’ha considerat la idea que també podria ser rellevant en el cas de béns comuns de caire global, seguint l’evidència bàsicament descriptiva recollida per Elinor Ostrom. Però fins ara no hi havia proves quantitatives disponibles d’aquesta idea. Utilitzant un conjunt de dades de 29 països europeus durant el període 1990-2007, donem evidència empírica a favor del paper del nivell de confiança en els altres en el context dels béns públics globals. Concloem que el nivell de confiança en els altres té un impacte reductor de les emissions de gasos d’efecte hivernacle; per exemple, l’extrapolació dels resultats implicaria una reducció d’emissions d’Espanya del 12,5% si el nivell mitjà de confiança en els altres dels espanyols fos tan elevat com els dels suecs.
Resumo:
The assembly and maintenance of the International Thermonuclear Experimental Reactor (ITER) vacuum vessel (VV) is highly challenging since the tasks performed by the robot involve welding, material handling, and machine cutting from inside the VV. The VV is made of stainless steel, which has poor machinability and tends to work harden very rapidly, and all the machining operations need to be carried out from inside of the ITER VV. A general industrial robot cannot be used due to its poor stiffness in the heavy duty machining process, and this will cause many problems, such as poor surface quality, tool damage, low accuracy. Therefore, one of the most suitable options should be a light weight mobile robot which is able to move around inside of the VV and perform different machining tasks by replacing different cutting tools. Reducing the mass of the robot manipulators offers many advantages: reduced material costs, reduced power consumption, the possibility of using smaller actuators, and a higher payload-to-robot weight ratio. Offsetting these advantages, the lighter weight robot is more flexible, which makes it more difficult to control. To achieve good machining surface quality, the tracking of the end effector must be accurate, and an accurate model for a more flexible robot must be constructed. This thesis studies the dynamics and control of a 10 degree-of-freedom (DOF) redundant hybrid robot (4-DOF serial mechanism and 6-DOF 6-UPS hexapod parallel mechanisms) hydraulically driven with flexible rods under the influence of machining forces. Firstly, the flexibility of the bodies is described using the floating frame of reference method (FFRF). A finite element model (FEM) provided the Craig-Bampton (CB) modes needed for the FFRF. A dynamic model of the system of six closed loop mechanisms was assembled using the constrained Lagrange equations and the Lagrange multiplier method. Subsequently, the reaction forces between the parallel and serial parts were used to study the dynamics of the serial robot. A PID control based on position predictions was implemented independently to control the hydraulic cylinders of the robot. Secondly, in machining, to achieve greater end effector trajectory tracking accuracy for surface quality, a robust control of the actuators for the flexible link has to be deduced. This thesis investigates the intelligent control of a hydraulically driven parallel robot part based on the dynamic model and two schemes of intelligent control for a hydraulically driven parallel mechanism based on the dynamic model: (1) a fuzzy-PID self-tuning controller composed of the conventional PID control and with fuzzy logic, and (2) adaptive neuro-fuzzy inference system-PID (ANFIS-PID) self-tuning of the gains of the PID controller, which are implemented independently to control each hydraulic cylinder of the parallel mechanism based on rod length predictions. The serial component of the hybrid robot can be analyzed using the equilibrium of reaction forces at the universal joint connections of the hexa-element. To achieve precise positional control of the end effector for maximum precision machining, the hydraulic cylinder should be controlled to hold the hexa-element. Thirdly, a finite element approach of multibody systems using the Special Euclidean group SE(3) framework is presented for a parallel mechanism with flexible piston rods under the influence of machining forces. The flexibility of the bodies is described using the nonlinear interpolation method with an exponential map. The equations of motion take the form of a differential algebraic equation on a Lie group, which is solved using a Lie group time integration scheme. The method relies on the local description of motions, so that it provides a singularity-free formulation, and no parameterization of the nodal variables needs to be introduced. The flexible slider constraint is formulated using a Lie group and used for modeling a flexible rod sliding inside a cylinder. The dynamic model of the system of six closed loop mechanisms was assembled using Hamilton’s principle and the Lagrange multiplier method. A linearized hydraulic control system based on rod length predictions was implemented independently to control the hydraulic cylinders. Consequently, the results of the simulations demonstrating the behavior of the robot machine are presented for each case study. In conclusion, this thesis studies the dynamic analysis of a special hybrid (serialparallel) robot for the above-mentioned special task involving the ITER and investigates different control algorithms that can significantly improve machining performance. These analyses and results provide valuable insight into the design and control of the parallel robot with flexible rods.
Resumo:
The purpose of this study was to identify the impact of stressors and offsetting satistiers, measured in this study with Stress Offset Score (SOS), on intentions to quit and examine the mediating and moderating effects of three facets of work satisfaction (job satisfaction, pay satisfaction, and satisfaction with supervisor) and two facets of organizational commitment (affective and nonnative commitment) on this relationship. The sample was composed of 2990 employees from 21 public and private organizations. The interaction of each type of work satisfaction and organizational commitment, with SOS, was tested using Ordinary Least Squares (OLS) procedures. Intentions to quit was the dependent variable. The research questions were determine: (1) Does SOS predict intentions to quit? (2) Does work satisfaction mediate the predictive relationship of SOS on intentions to quit? (3) Does organizational commitment mediate the predictive relationship of SOS on intent to quit? (4) Does work satisfaction moderate the predictive relationship of SOS on intentions to quit? and (5) Does organizational commitment moderate the predictive relationship of SOS on intentions to quit? The results indicated that SOS was negatively correlated with intentions to quit. Each of the types of work satisfaction and organizational commitment variables showed a partial mediated relationship with SOS and each relationship was highly significant, while normative commitment explained more of the relationship then other mediators. The study also tested for interactions but no statistical significant relationships where established between any of the interaction terms (e.g., SOSxJob Satisfaction and SOSxAffcctive Commitment) and intentions to quit.
Resumo:
The objective of this investigation was to clarify the adaptive significance of female sexual behaviours in the house cricket, Acheta domesticus, and the Texas field cricket, Gryllus integer. Experiments were focussed primarily on: nutritional factors affecting female reproductive success; the ontogeny of female sexual behaviours; female mating frequency and progeny production; and the pattern of sperm competition. Reproduction of singly mated female A. domesticus assigned to 3 nutritional regimes was compared . Females fed a vitamin and protein-enriched mouse chow, cannibalistic females, and starved females produced on the average, 513 , 200 and 68 offspring, respectively. Cannibals probably could not obtain the same amounts of essential nutrients as females fed mouse chow. Reabsorption of oocytes was likely the major factor contributing to the decreased reproduction of starved females. In addition, female !. domesticus fed mouse chow, but allowed constant access to males produced 11 times as many offspring than did females fed corn meal. Females fed corn meal probably could not absorb or synthesize enough dietary lipids, thus resulting in poor ovariole growth. Female !. domesticus first mate at an average adult age of 7 days, closely corresponding to when they first exhibit positive phonotaxis. Females mate repeatedly and often consume the externally attached spermatophore. In ~. domesticus, females allowed constant access to males produced significantly more offspring than did single maters. Similarly, doubly mated G. integer females produced more offspring than did single maters. This difference resulted largely from the failure of many single maters to reproduce. Remating by female crickets partly functions in offsetting the possibility of a failed initial mating. Nymph production increased significantly with the time the spermatophore was attached in singly mated ~. domesticus. Spermatophore consumption by the female was not affected by male guarding behaviour, and the interval between mating and eating of the spermatophore may often be shorter than the time required for maximum insemination. Some degree of sperm depletion in singly mated !. domesticus and G. integer may have occurred. The patterns of daily offspring production of singly and multiplymated females suggests that a factor provided by a male during mating stimulates female oviposition and/or egg production. Female crickets also might acquire nutrition from spermatophore consumption, a benefit that is augmented by female multiple mating. The electrophoretic examination of various allozymes in ~. integer did not permit determination of a pattern of sperm competition. However, the possibility of last male sperm predominance is related to male guarding behaviour.
Resumo:
Within local-spin-density functional theory, we have investigated the ¿dissociation¿ of few-electron circular vertical semiconductor double quantum ring artificial molecules at zero magnetic field as a function of interring distance. In a first step, the molecules are constituted by two identical quantum rings. When the rings are quantum mechanically strongly coupled, the electronic states are substantially delocalized, and the addition energy spectra of the artificial molecule resemble those of a single quantum ring in the few-electron limit. When the rings are quantum mechanically weakly coupled, the electronic states in the molecule are substantially localized in one ring or the other, although the rings can be electrostatically coupled. The effect of a slight mismatch introduced in the molecules from nominally identical quantum wells, or from changes in the inner radius of the constituent rings, induces localization by offsetting the energy levels in the quantum rings. This plays a crucial role in the appearance of the addition spectra as a function of coupling strength particularly in the weak coupling limit.
Resumo:
El objetivo de esta monografía es examinar la transformación de la doctrina de seguridad de la OTAN en la Post-Guerra Fría y sus efectos en la intervención en la República de Macedonia. La desintegración del bloque soviético implicó la variación en la definición de las amenazas que atentan contra la supervivencia de los países miembro de la Alianza Atlántica. A partir de la década de los noventa, los conflictos de naturaleza interétnica pasaron a formar parte de los riesgos que transgreden la seguridad de los Aliados y la estabilidad del área Euro-Atlántica. Por lo anterior, la OTAN intervino en aquellos Estados en los que prevalecían las confrontaciones armadas interétnicas, como por ejemplo: en Macedonia. Allí, la Alianza Atlántica ejecutó operaciones de gestión de crisis para contrarrestar la amenaza. El fenómeno a estudiar en esta investigación será analizado a partir del Realismo Subalterno y de la Teoría de la Seguridad Colectiva.
Resumo:
We investigate the factors precipitating market entry where smallholders make decisions about participation (a discrete choice about whether to sell quantities of products) and supply (a continuous-valued choice about how much quantity to sell) in a cross-section of smallholders in Northern Luzon, Philippines, in a model that combines basic probit and Tobit ideas, is implemented using Bayesian methods, and generates precise estimates of the inputs required in order to effect entry among the non-participants. We estimate the total amounts of (cattle, buffalo, pig and chicken) livestock input required to effect entry and compare and contrast the alternative input requirements. To the extent that our smallholder sample may be representative of a wide and broader set of circumstances, our findings shed light on offsetting impacts of conflicting factors that complicate the roles for policy in the context of expanding the density of participation.