The handshake : why do governments and firms sign private sector participation deals ? Evidence from the water and sanitation sector in developing countries

This paper uses a new dataset,"WATSAN,"of private sector participation(PSP) projects for water and sanitation in developing countries to examine the determinants of the number of projects signed for each country between 1990 and 2004. The new dataset improves on existing sources, in particular in its coverage of projects with local investors, and provides adequate data for cross-country regression analysis. The authors use a negative binomial regression model to investigate the factors influencing the number of PSP projects in a sample of 60 developing countries with 460 PSP projects. The regression results provide support for the hypotheses that PSP is greater in larger markets where the ability to pay is higher and where governments are fiscally constrained. The authors test several indicators of institutional quality and find that these are generally significant in determining the number of projects signed for each country. Measures of the protection of property rights and the quality of the bureaucracy emerge as the most important institutions that encourage PSP. Rule of law and the control of corruption are significant, albeit at a lower level, while the quality of contract law and political stability are not robustly significant.Private Participation in Infrastructure,Town Water Supply and Sanitation,Investment and Investment Climate,Infrastructure Regulation,Water Supply and Sanitation Governance and Institutions

Some variance reduction methods for numerical stochastic homogenization

We overview a series of recent works devoted to variance reduction techniques for numerical stochastic homogenization. Numerical homogenization requires solving a set of problems at the micro scale, the so-called corrector problems. In a random environment, these problems are stochastic and therefore need to be repeatedly solved, for several configurations of the medium considered. An empirical average over all configurations is then performed using the Monte-Carlo approach, so as to approximate the effective coefficients necessary to determine the macroscopic behavior. Variance severely affects the accuracy and the cost of such computations. Variance reduction approaches, borrowed from other contexts of the engineering sciences, can be useful. Some of these variance reduction techniques are presented, studied and tested here

EX ANTE CONSTRUCTION COSTS IN THE EUROPEAN ROAD SECTOR: A COMPARISON OF PUBLIC-PRIVATE PARTNERSHIPS AND TRADITIONAL PUBLIC PROCUREMENT

Theoretical literature suggests a variety of reasons why a public-private partnership (PPP)should exhibit higher costs of construction than traditionally procured public infrastructure projects. The bundling of construction and operation contracts in a PPP give the private partner greater incentives to make investments in the construction phase to lower subsequent operation and maintenance costs. Also, the transfer of the construction risk to the private partner should be explicitly priced in a PPP. We use data on ex ante construction costs of road projects in Europe to test the existence and the magnitude of any such difference between PPPs and traditional procurement. We estimate the ex ante cost of a PPP road to be, on average, 24% more expensive than a traditionally procured road, all other things equal. This estimate corresponds by and large to reported ex post cost overruns in traditionally procured public roads. To the extent that the two measures are representative, this suggests that the largest part of the ex ante construction cost difference originates from the transfer of construction risk. This, in turn, implies that other possible sources of higher PPP construction costs, including bundling, seem to be of second-order importance in the road sector. The analysis does not allow drawing normative conclusions about the desirability of PPP as a procurement method as it focuses only on one cost component in isolation, without being able to quantify its impact on life-cycle costs and benefits.Construction costs; Road sector; public-private partnership; public procurement; infrastructure projects; Europe

PUBLIC-PRIVATE PARTNERSHIPS IN EUROPE: AN UPDATE

This paper offers an updated description of the macroeconomic and sectoral significance of PPPs in Europe, without assessing PPPs from a normative perspective. It shows that, over the past fifteen years, more than one thousand PPP contracts have been signed in the EU, representing a capital value of almost 200 billion euro. While PPPs have in recent years become increasingly popular in a growing number of European countries, they are of macroeconomic and systemic significance only in the UK, Portugal, and Spain. In all other European countries, the importance of investment through PPPs remains small in comparison to traditional public procurement of investment projects. However, PPP procurement is used extensively for major projects and this is spreading out from transport into other sectors.public-private partnership; Europe

IZI: Inferring the gas phase metallicity (Z) and ionization parameter (q) of ionized nebulae using bayesian statistics

We present a new method for inferring the metallicity (Z) and ionization parameter (q) of H ii regions and star-forming galaxies using strong nebular emission lines (SELs). We use Bayesian inference to derive the joint and marginalized posterior probability density functions for Z and q given a set of observed line fluxes and an input photoionization model. Our approach allows the use of arbitrary sets of SELs and the inclusion of flux upper limits. The method provides a self-consistent way of determining the physical conditions of ionized nebulae that is not tied to the arbitrary choice of a particular SEL diagnostic and uses all the available information. Unlike theoretically calibrated SEL diagnostics, the method is flexible and not tied to a particular photoionization model. We describe our algorithm, validate it against other methods, and present a tool that implements it called IZI. Using a sample of nearby extragalactic H ii regions, we assess the performance of commonly used SEL abundance diagnostics. We also use a sample of 22 local H ii regions having both direct and recombination line (RL) oxygen abundance measurements in the literature to study discrepancies in the abundance scale between different methods. We find that oxygen abundances derived through Bayesian inference using currently available photoionization models in the literature can be in good (∼30%) agreement with RL abundances, although some models perform significantly better than others. We also confirm that abundances measured using the direct method are typically ∼0.2 dex lower than both RL and photoionization-model-based abundances

Influence of Functionalization of Nanocontainers on Self-Healing Anticorrosive Coatings

Feedback coating based on pH-induced release of inhibitor from organosilyl-functionalized containers is considered as a compelling candidate to achieve smart self-healing corrosion protection. Four key factors that determine the overall coating performance include 1) the uptake and release capacity of containers, 2) prevention of the premature leakage, 3) compatibility of containers in coating matrix and 4) cost and procedure simplicity consideration. The critical influence introduced by organosilyl-functionalization of containers is systematically demonstrated by investigating MCM-41 silica nanoparticles modified with ethylenediamine (en), en-4-oxobutanoic acid salt (en-COO-) and en-triacetate (en-(COO-)3) with higher and lower organic contents. The properties of the modified silica nanoparticles as containers were mainly characterized by solid-state 13C nuclear magnetic resonance, scanning and transmission electron microscopy, N2 sorption, thermogravimetric analysis, small-angle X-ray scattering, dynamic light scattering and UV-vis spectroscopy. Finally, the self-healing ability and anticorrosive performances of hybrid coatings were examined through scanning vibrating electrode technique (SVET) and electrochemical impedance spectroscopy (EIS). en-(COO-)3- type functionalization with content of only 0.23 mmol/g was found to perform the best as a candidate for establishing pH-induced release system. It is because the resulting capped and loaded (C-L) functionalized silica nanocontainers (FSNs) exhibit a high loading (26 wt%) and release capacity (80%) for inhibitor, prevention of premature leakage (less than 2%), good dispersibility in coating matrix and cost effectiveness

Joint Experimental and Computational O-17 and H-1 Solid State NMR Study of Ba2In2O4(OH)(2) Structure and Dynamics

This is the final version of the article. It first appeared from ACS Publications via http://dx.doi.org/10.1021/acs.chemmater.5b00328A structural characterization of the hydrated form of the brownmillerite-type phase Ba2In2O5, Ba2In2O4(OH)2, is reported using experimental multinuclear NMR spectroscopy and density functional theory (DFT) energy and GIPAW NMR calculations. When the oxygen ions from H2O fill the inherent O vacancies of the brownmillerite structure, one of the water protons remains in the same layer (O3) while the second proton is located in the neighboring layer (O2) in sites with partial occupancies, as previously demonstrated by Jayaraman et al. ( Solid State Ionics 2004, 170, 25?32) using X-ray and neutron studies. Calculations of possible proton arrangements within the partially occupied layer of Ba2In2O4(OH)2 yield a set of low energy structures; GIPAW NMR calculations on these configurations yield 1H and 17O chemical shifts and peak intensity ratios, which are then used to help assign the experimental MAS NMR spectra. Three distinct 1H resonances in a 2:1:1 ratio are obtained experimentally, the most intense resonance being assigned to the proton in the O3 layer. The two weaker signals are due to O2 layer protons, one set hydrogen bonding to the O3 layer and the other hydrogen bonding alternately toward the O3 and O1 layers. 1H magnetization exchange experiments reveal that all three resonances originate from protons in the same crystallographic phase, the protons exchanging with each other above approximately 150 ?C. Three distinct types of oxygen atoms are evident from the DFT GIPAW calculations bare oxygens (O), oxygens directly bonded to a proton (H-donor O), and oxygen ions that are hydrogen bonded to a proton (H-acceptor O). The 17O calculated shifts and quadrupolar parameters are used to assign the experimental spectra, the assignments being confirmed by 1H?17O double resonance experiments.This work was supported in part by Grants DMR050612 and CHE0714183 from the National Science Foundation and Grant DESC0001284 from the Department of Energy (supporting Y.- L.L. and D.M.), by an Advanced Fellowship from the EU-ERC (C.P.G.), and by the EPSRC (D.S.M.). F.B. thanks the EU Marie Curie actions FP7 for an International Incoming fellowship (Grant No. 275212) and Clare Hall, University of Cambridge, for a Research Fellowship

Distribution of trace elements in waters and sediments of the Seversky Donets transboundary watershed (Kharkiv region, Eastern Ukraine)

International audienceThis paper reports on the aquatic chemistry of trace elements in terms of spatial and temporal distribution, but also pollution sources in the transboundary watershed of the Seversky Donets River (Ukraine/Russia). Bed sediments and filtered water were collected from the Udy and Lopan Rivers at sites from the river source in the Belgorod region (Russia) to rural and urban areas in the Kharkiv region (Ukraine) in May and August 2009. Priority trace elements (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn), an urban tracer (Ag) and additional metals (Co, Mo, V) and Th were measured in stream water and sediments. The low levels and variability of Th-normalized concentrations indicated the absence of geochemical anomalies in the upstream part of the rivers and suggested that these data represent a regional baseline for trace elements in bed sediments. In contrast, water and sediments within the city of Kharkiv were contaminated by Ag, Pb, Cd, Cu, Cr and Zn, which are mainly attributed to municipal wastewater inputs and urban run-off. Results of the environmental quality assessment showed that element concentrations in the sediments can be considered as potentially toxic to aquatic organisms in sites downstream of the wastewater discharges