3,184 research outputs found
A new paradigm of governance for a carbon-pricing system
Throughout its life, the United Nations has played a pioneering role in the world of ideas. COP21 â also known as Paris 2015 â shows the path for the United Nations to establish a new governance that will enforce the compliance of a new planetary carbon-pricing system. Maintaining global warming below 2 °C means implementing an efficient carbon-pricing system, supported by effective measures promoting a green energy transition. A planetary carbon governance yields a number of new insights that include the following: (1) a bonus-malus system with a fixed signal price for carbon, (2) a planetary carbon market that will gather existing regional carbon markets, (3) a hybrid carbon-pricing system linking a carbon tax and a carbon market for advanced countries and (4) a support mechanism for emerging and developing countries to assist them with a carbon-pricing system. This new governance will promote an energy transition plan. In the COP21 context, responsible policymaking requires key characteristics for the enforcement of a successful planetary carbon-pricing system
Competitive adsorption of phenolic compounds from aqueous solution using sludgeâbased activated carbon.
Preparation of activated carbon from sewage sludge is a promising approach to produce cheap and efficient adsorbent for pollutants removal as well as to dispose of sewage sludge. The first objective of this study was to investigate the physical and chemical properties (BET surface area, ash and elemental content, surface functional groups by Boehm titration and weight loss by thermogravimetric analysis) of the sludgeâbased activated carbon (SBAC) so as to give a basic understanding of its structure and to compare to those of two commercial activated carbons, PICA S23 and F22. The second and main objective was to evaluate the performance of SBAC for single and competitive adsorption of four substituted phenols (pânitrophenol, pâchlorophenol, pâhydroxy benzoic acid and phenol) from their aqueous solutions. The results indicated that, despite moderate micropore and mesopore surface areas, SBAC had remarkable adsorption capacity for phenols, though less than PICA carbons. Uptake of the phenolic compound was found to be dependent on both the porosity and surface chemistry of the carbons. Furthermore, the electronegativity and the hydrophobicity of the adsorbate have significant influence on the adsorption capacity. The Langmuir and Freundlich models were used for the mathematical description of the adsorption equilibrium for singleâsolute isotherms. Moreover, the LangmuirâFreundlich model gave satisfactory results for describing multicomponent system isotherms. The capacity of the studied activated carbons to adsorb phenols from a multiâsolute system was in the following order: pânitrophenol > pâchlorophenol > PHBA > phenol
Corporate voluntary greenhouse gas reporting: stakeholder pressure and the mediating role of the chief executive officer
The study sheds light on the extent to which various stakeholder pressures influence voluntary disclosure of greenhouse gas (GHG) emissions and how the impact is explained and moderated Chief executive office (CEO) characteristics of 215 FTSE350 listed United Kingdom (UK) companies for the year 2011. The study developed a classification of GHG emission disclosure based on the guidelines of GHG Protocol, DEFRA and Global Framework for Climate Risk Disclosure using content analysis. Evidence from the study suggests that some stakeholder pressure (regulatory, creditor, supplier, customer, board control) positively impacts on GHG disclosure information by firms. We found stakeholder pressure in the form of regulatory, mimetic and shareholders pressure positively influenced the disclosure of GHG information. We also found creditor pressure also had a significant negative relationship with GHG disclosure. While CEO age had a direct negative effect on GHG voluntary disclosure, its moderation effect on stakeholder pressure influence on GHG disclosure was only significant on regulatory pressure
Central limit theorem for bifurcating {M}arkov chains under point-wise ergodic conditions
Bifurcating Markov chains (BMC) are Markov chains indexed by a full binary
tree representing the evolution of a trait along a population where each
individual has two children. We provide a central limit theorem for general
additive functionals of BMC, and prove the existence of three regimes. This
corresponds to a competition between the reproducing rate (each individual has
two children) and the ergodicity rate for the evolution of the trait. This is
in contrast with the work of Guyon (2007), where the considered additive
functionals are sums of martingale increments, and only one regime appears. Our
result can be seen as a discrete time version, but with general trait
evolution, of results in the time continuous setting of branching particle
system from Adamczak and Mi\l{}o\'{s} (2015), where the evolution of the trait
is given by an Ornstein-Uhlenbeck process.Comment: 3
Direction-finding arrays of directional sensors for randomly located sources
The problem of directional sensor placement and orientation is considered when statistical information about the source direction of arrival is available. We focus on two-sensor arrays and form a cost function based on the Cramer-Rao bound that depends on the probability distribution of the coplanar source direction. Proper positioning and orientation of the sensors enable the two-sensor array to have an accuracy comparable to that of a three-or four-sensor uniform circular array
From Paper to Praxis: Advancing the Discipline in a Small College Environment
This article proposes the advancement of communications discipline at a small college in Georgia. In the small liberal arts college, one tends to find many faculty members who have had little or no experience with departments of communication. It is also plausible that some approaches to the study of communication may be deemed unsuitable in a small liberal arts setting. To meet the demands of the millennial technological environment, the dean of the college decided to reexamine the communication major in terms of its scope and function on campus. The proposals for the advancement of the discipline are discussed herein
Variations de tolérance aux pesticides agricoles des diatomées périphytiques dans une riviÚre contaminée : une analyse de l'échelle des communautés à celle des populations
3rd International Conference on EnvironmentalManagement, Engineering, Planning and Economics (CEMEPE 2011) & SECOTOX Conference, Skiathos, GRC, 19-/06/2011 - 24/06/2011International audiencePeriphytic diatoms are an important phototrophic component of river biofilm and are used in situ for the bioindication of pollution as well as in laboratory ecotoxicological tests to assess the toxicity of contaminants. In spring 2009, phototrophic biofilm samples composed mostly of diatoms were collected in a small river and their sensitivity to the herbicide diuron was estimated via photosynthesis bioassays. A large difference in tolerance to diuron was demonstrated between two periphytic communities from an upstream unpolluted site and a downstream site subjected to high seasonal contamination by pesticides. The comparison of diatom community structure between sites revealed important variations of the relative abundance of some species which could explain this difference. Consequently, some of these species were isolated from the river in autumn when toxic pressure was low, and kept in culture for more than six months in uncontaminated water. Acute toxicity tests of diuron based on growth inhibition were then performed on each species. Surprisingly the sensitivities of the species as estimated by EC50 were almost the same. However two strains of another species that could be isolated from each site of the river showed significant differences in tolerance to diuron and copper, another contaminant of the river. These results suggest the importance of adaptation at the intraspecific level in the induction of periphytic community tolerance to toxicants and the probably low sensitivity of bioindication methods to assess river contaminations
Magnetic and Metal-Insulator Transitions in beta-Na0.5CoO2 and gamma-K0.5CoO2 -NMR and Neutron Diffraction Studies-
Co-oxides beta-Na0.5CoO2 and gamma-K0.5CoO2 have been prepared by the Na
de-intercalation from alpha-NaCoO2 and by the floating-zone method,
respectively. It has been found that successive phase transitions take place at
temperatures Tc1 and Tc2 in both systems. The appearance of the internal
magnetic field at Tc1 with decreasing temperature T indicates that the
antiferromagnetic order exists at T < Tc1, as in gamma-Na0.5CoO2. For
beta-Na0.5CoO2, the transition temperatures and the NMR parameters determined
from the data taken for magnetically ordered state are similar to those of
gamma-Na0.5CoO2, indicating that the difference of the stacking ways of the
CoO2 layers between these systems do not significantly affect their physical
properties. For gamma-K0.5CoO2, the quantitative difference of the physical
quantities are found from those of beta- and gamma-Na0.5CoO2. The difference
between the values of Tci (i = 1 and 2) of these systems might be explained by
considering the distance between CoO2 layers.Comment: 8 pages, 14 figures, 1 Tabl
- âŠ