Impacts of the Kigali Amendment to phase-down hydrofluorocarbons (HFCs) in Asia

The Montreal Protocol (UNEP, 2007) has successfully worked to phase out the use of ozone depleting substances (ODSs) primarily by substituting the use of chlorofluorocarbons (CFCs) and hydrochloroflourocarbons (HCFCs) with hydrofluorocarbons (HFCs) in various sectors such as refrigeration, air-conditioning, aerosols, fire extinguishers and foam blowing. As well, HFC-23 is generated as a by-product of HCFC-22 production for feedstock and emissive use. The high Global Warming Potentials (GWP) of HFCs replacing ODSs is a climate concern and the reason behind the Kigali Amendment of the Montreal Protocol adopted during the 28th Meeting of the Parties 8-14 October 2016 in Kigali, Rwanda (UNEP, 2016a) to phase-down the use of HFCs globally by 2050. HFC emissions have increased significantly in recent years and can without a targeted HFC phase-down be expected to rise further in response to increased demand for cooling services and the phase-out of ODSs. The focus of this study is to analyze the implications on emissions and co-benefits like electricity savings of meeting the HFC phase-down targets in Asian countries set out in the Kigali Amendment to the Montreal Protocol. We develop baseline and alternative policy scenarios for Asian countries using the HFC module of the Greenhouse gas and Air pollution Interactions and Synergies (GAINS) model (http://gains.iiasa.ac.at) framework developed by the International Institute for Applied Systems Analysis and described in Purohit and Höglund-Isaksson (2017). The report is structured as follows: Section 2 briefly explains different policy scenarios analyzed in this study. Section 3 highlights key control measures adopted by Asian countries. Section 4 presents estimated HFC emissions in different policy scenarios along with mitigation potentials and discusses possible co-benefits associated with mitigation. Section 5 concludes key findings and policy recommendations

Supporting Additive Manufacturing Technology Development through Constraint Modelling in Early Conceptual Design: A Satellite Propulsion Case Study

Function and constraints modelling are implemented to design two gridded ion thrusters for additive manufacturing (AM). One concept takes advantage of AM design freedom, disregarding AM limitations and is not feasible. The other concept considers AM limitations and is manufacturable and feasible. Constraints modelling highlights AM capabilities that can be improved, showing where future investment is needed. Constraints representation can also support the creation of technology development roadmaps able to identify areas of AM technologies that must be improved

Zipper - a Duplex Method for VDSL based on DMT

We present a new duplex scheme, called Zipper, for discrete multitone (DMT)-based very high bit-rate digital subscriber line (VDSL) systems on copper wires. This scheme divides the available bandwidth by assigning different subcarriers for the upstream and downstream directions. It has high flexibility to divide the capacity between the up and downstream, as well as good coexistence possibilities with other systems such as ADSL. Simulation results show the high bit-rate performance in different environments such as mixed ADSL and VDSL traffic under radio frequency interference and with different background noise source

Electromagnetic proton-neutron knockout off 16O: new achievements in theory

Results for the cross sections of the exclusive 16O(e,e'pn)14N and 16O(gamma,pn)14N knockout reactions are presented and discussed in different kinematics. In comparison with earlier work, a complete treatment of the center-of-mass (CM) effects in the nuclear one-body current is considered in connection with the problem of the lack of orthogonality between initial bound and final scattering states. The effects due to CM and orthogonalization are investigated in combination with different treatments of correlations in the two-nucleon overlap function and for different parametrizations of the two-body currents. The CM effects lead in super-parallel kinematics to a dramatic increase of the 16O(e,e'pn) cross section to the 1_2^+ excited state (3.95 MeV) of 14N. In all the situations considered the results are very sensitive to the treatment of correlations. A crucial role is played by tensor correlations, but also the contribution of long-range correlations is important.Comment: 13 pages, 10 figure

The contribution of non-CO2 greenhouse gas mitigation to achieving long-term temperature goals

In the latest (fifth) assessment from the Intergovernmental Panel on Climate Change (IPCC) non-CO2 emssions accounted for 28% of total GHG emissions in 2010, when measured on the basis of their global warming potential (relative to CO2) over a 100-year and nitrous oxide (N2O) accounting for about half of all non-CO2 GHGs. With population and incomes increasing, especially in emerging economies, these emissions could grow significantly in the future. Other major sources of non-CO2 GHGs are fugitive CH4 from the extraction and distribution of fossil fuels, N2O from industrial production of nitric and adipic acid, as well as fluorinated gases (F-gases) from a range of industrial manufacturing and product uses. This paper analyses the emissions and cost impacts of mitigation of non-CO2 greenhouse gases (GHGs) at a global level, in scenarios which are focused on meeting a range of long-term temperature goals (LTTGs). The paper demonstrates how an integrated assessment model (TIAM-Grantham) representing CO2 emissions (and their mitigation) from the fossil fuel combustion and industrial sectors is coupled with a model covering non-CO2 emissions (GAINS) in order to provide a complete picture of GHG emissions in a reference scenario in which there is no mitigation of either CO2 or non-CO2 gases, as well as in scenarios in which both CO2 and non-CO2 gases are mitigated in order to achieve different LTTGs

Environmental improvements of the 2012 revision of the Gothenburg Protocol

In May 2012, Parties to the Convention on Long-range Transboundary Air Pollution have reached agreement on a revision of its Gothenburg multi-pollutant/multi-effect protocol. Inter alia, the revised protocol includes quantitative emission reduction commitments for the year 2020. This report estimates the improvements for human health and ecosystems protection that can be expected from the committed emission reductions in 2020