How Green Public Procurement Contributes to Sustainable Development in China: Evidence from the IISD Green Public Procurement Model

The People's Republic of China spent more than CNY 1.6 trillion (USD 252 billion) on procurement in 2013, accounting for 11.7 per cent of all national spending (Ministry of Finance of the People's Republic of China, 2014). In light of these numbers, the potential environmental, social and economic multipliers of greening government purchases become evident. The benefits of a comprehensive and efficient green public procurement (GPP) policy are not limited to the green products and services the public sector buys, but will have a ripple effect that encourages green consumption nationwide. The significant purchasing power of the government will provide the much-needed incentives in order for businesses to invest and innovate in green products and services to meet the government's guaranteed long-term and high-volume demand. Additionally, GPP is in line with China's national plans to pioneer "eco-civilisation" and with the upcoming 13th Five-Year Plan (FYP), which underlines the importance of GPP.This paper is the second and final component of IISD's contribution to greening public procurement in China. Our discussion paper Green Public Procurement in China: Quantifying the Benefits, published in April 2015, analyzed China's GPP landscape, taking a closer look at current practices, actors at different levels of government and the underlying legal framework. In addition, the paper introduced the IISD GPP Model, discussing its potential for quantifying and communicating the benefits of GPP, while providing a high-level overview of the modelling approach used and of the scope of the model envisioned. Building on the results of the IISD GPP Model, consultations with stakeholders and an extensive literature review, this paper provides targeted recommendations addressing the development areas identified to improve GPP in China. The recommendations follow a multiphase approach offering more immediate solutions as well as more ambitious, larger-scale overhauls of the GPP framework for the long term. The results of the IISD GPP Model will be shared for the first time as part of this paper, making the case for green procurement through analyzing five product categories: air conditioners, lighting, cars, paper and cement. These categories were selected because they represent significant financial flows in procurement, have notable environmental impacts and domestic production, and have sufficient data available to facilitate their analysis. A detailed overview of the key elements of the modelling approach will be provided, in addition to an explanation of the model setup and the range of externalities monetised for each product category. Finally, we will look at how to use the model at the different levels of government as well as how its scope can be extended and customised in order to leverage its potential under a wider range of circumstances and areas of procurement

Deflection compensation on a force sensing mobile machine tool

Within this paper, a model based deflection compensation for a mobile machine tool prototype is presented. The model compensates the deflection of the tool center point (TCP) based on strain gauge measurements at the machines foot modules. The measured strains at each foot are used to calculate pose dependent gravitational forces as well as disturbance forces. These forces are then passed to the model. Hence, the model reconstructs the deflection of the TCP based on the measured forces at the foot modules

Nonlinear dielectric epsilon near-zero hybrid nanogap antennas

High-index Mie-resonant dielectric nanostructures provide a new framework to manipulate light at the nanoscale. In particular their local field confinement together with their inherently low losses at frequencies below their band-gap energy allows to efficiently boost and control linear and nonlinear optical processes. Here, we investigate nanoantennas composed of a thin indium-tin oxide layer in the center of a dielectric Gallium Phosphide nanodisk. While the linear response is similar to that of a pure GaP nanodisk, we show that the second and third-harmonic signals of the nanogap antenna are boosted at resonance. Linear and nonlinear finite-difference time-domain simulations show that the high refractive index contrast leads to strong field confinement inside the antenna's ITO layer. Measurement of ITO and GaP nonlinear susceptibilities deliver insight on how to engineer nonlinear nanogap antennas for higher efficiencies for future nanoscale devices.Comment: main: 18 pages, 4 figues, supplemental: 8 pages, 4 figures, 1 tabl

High-Q Nanophotonics over the Full Visible Spectrum Enabled by Hexagonal Boron Nitride Metasurfaces

All-dielectric optical metasurfaces with high quality (Q) factors have been hampered by the lack of simultaneously lossless and high-refractive-index materials over the full visible spectrum. In fact, the use of low-refractive-index materials is unavoidable for extending the spectral coverage due to the inverse correlation between the bandgap energy (and therefore the optical losses) and the refractive index (n). However, for Mie resonant photonics, smaller refractive indices are associated with reduced Q factors and low mode volume confinement. Here, symmetry-broken quasi bound states in the continuum (qBICs) are leveraged to efficiently suppress radiation losses from the low-index (n approximate to 2) van der Waals material hexagonal boron nitride (hBN), realizing metasurfaces with high-Q resonances over the complete visible spectrum. The rational use of low- and high-refractive-index materials as resonator components is analyzed and the insights are harnessed to experimentally demonstrate sharp qBIC resonances with Q factors above 300, spanning wavelengths between 400 and 1000 nm from a single hBN flake. Moreover, the enhanced electric near fields are utilized to demonstrate second-harmonic generation with enhancement factors above 10(2). These results provide a theoretical and experimental framework for the implementation of low-refractive-index materials as photonic media for metaoptics

Fibre optic distributed acoustic sensing of volcanic events

Understanding physical processes prior to and during volcanic eruptions has improved significantly in recent years. However, uncertainties about subsurface structures distorting observed signals and undetected processes within the volcano prevent volcanologists to infer subtle triggering mechanisms of volcanic phenomena. Here, we demonstrate that distributed acoustic sensing (DAS) with optical fibres allows us to identify volcanic events remotely and image hidden near-surface volcanic structural features. We detect and characterize strain signals associated with explosions and locate their origin using a 2D-template matching between picked and theoretical wave arrival times. We find evidence for non-linear grain interactions in a scoria layer of spatially variable thickness. We demonstrate that wavefield separation allows us to incrementally investigate the ground response to various excitation mechanisms. We identify very small volcanic events, which we relate to fluid migration and degassing. Those results provide the basis for improved volcano monitoring and hazard assessment using DAS

Nanostructured amorphous gallium phosphide on silica for nonlinear and ultrafast nanophotonics

Nanophotonics based on high refractive index dielectrics relies on appreciable contrast between the indices of designed nanostructures and their immediate surrounding, which can be achieved by the growth of thin films on low-index substrates. Here we propose the use of high index amorphous gallium phosphide (a-GaP), fabricated by radio-frequency sputter deposition, on top of a low refractive index glass substrate and thoroughly examine its nanophotonic properties. Spectral ellipsometry of the amorphous material demonstrates the optical properties to be considerably close to crystalline gallium phosphide (c-GaP), with low-loss transparency for wavelengths longer than 650 nm. When nanostructured into nanopatches, the second harmonic (SH) response of an individual a-GaP patch is characterized to be more than two orders of magnitude larger than the as-deposited unstructured film, with an anapole-like resonant behavior. Numerical simulations are in good agreement with the experimental results over a large spectral and geometrical range. Furthermore, by studying individual a-GaP nanopatches through non-degenerate pump-probe spectroscopy with sub-10 fs pulses, we find a more than 5% ultrafast modulation of the reflectivity that is accompanied by a slower decaying free carrier contribution, caused by absorption. Our investigations reveal a potential for a-GaP as an adequate inexpensive and CMOS-compatible material for nonlinear nanophotonic applications as well as for photocatalysis.Fil: Tilmann, Benjamin. Ludwig Maximilians Universitat; AlemaniaFil: Grinblat, Gustavo Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Berté, Rodrigo. Ludwig Maximilians Universitat; AlemaniaFil: Özcan, Mehmet. Ludwig Maximilians Universitat; AlemaniaFil: Kunzelmann, Viktoria F.. Technische Universitat München; AlemaniaFil: Nickel, Bert. Ludwig Maximilians Universitat; AlemaniaFil: Sharp, Ian D.. Ludwig Maximilians Universitat; AlemaniaFil: Cortés, Emiliano. Ludwig Maximilians Universitat; AlemaniaFil: Maier, Stefan A.. Ludwig Maximilians Universitat; AlemaniaFil: Li, Yi. Southern University Of Science And Technology; Chin

The SWATH‐D seismological network in the Eastern Alps

The SWATH-D experiment involved the deployment of a dense temporary broadband seismic network in the Eastern Alps. Its primary purpose was enhanced seismic imaging of the crust and crust-mantle transition as well as improved constraints on local event locations and focal mechanisms in a complex part of the Alpine orogen. The study region is a key area of the Alps, where European crust in the north is juxtaposed and partially interwoven with Adriatic crust in the south, and a significant jump in the Moho depth was observed by the 2001 TRANSALP N-S profile. Here, a flip in subduction polarity has been suggested to occur. This dense network encompasses 163 stations and complements the larger-scale sparser AlpArray seismic network. The nominal station spacing in SWATH-D is 15 km in a high alpine, yet densely populated and industrialized region. We present here the challenges resulting from operating a large broadband network under these conditions and summarize how we addressed them, including the way we planned, deployed, maintained and operated the stations in the field. Finally, we present some recommendations based on our experiences

Fibre optic distributed acoustic sensing of volcanic events

Understanding physical processes prior to and during volcanic eruptions has improved significantly in recent years. However, uncertainties about subsurface structures distorting observed signals and undetected processes within the volcano prevent volcanologists to infer subtle triggering mechanisms of volcanic phenomena. Here, we demonstrate that distributed acoustic sensing (DAS) with optical fibres allows us to identify volcanic events remotely and image hidden near-surface volcanic structural features. We detect and characterize strain signals associated with explosions and locate their origin using a 2D-template matching between picked and theoretical wave arrival times. We find evidence for non-linear grain interactions in a scoria layer of spatially variable thickness. We demonstrate that wavefield separation allows us to incrementally investigate the ground response to various excitation mechanisms. We identify very small volcanic events, which we relate to fluid migration and degassing. Those results provide the basis for improved volcano monitoring and hazard assessment using DAS