Disentangling Sources of Momentum Fluctuations in Xe+Xe and Pb+Pb Collisions with the ATLAS Detector.

High-energy nuclear collisions create a quark-gluon plasma, whose initial condition and subsequent expansion vary from event to event, impacting the distribution of the eventwise average transverse momentum [P([p_{T}])]. Disentangling the contributions from fluctuations in the nuclear overlap size (geometrical component) and other sources at a fixed size (intrinsic component) remains a challenge. This problem is addressed by measuring the mean, variance, and skewness of P([p_{T}]) in ^{208}Pb+^{208}Pb and ^{129}Xe+^{129}Xe collisions at sqrt[s_{NN}]=5.

Combination of Searches for Higgs Boson Pair Production in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector.

This Letter presents results from a combination of searches for Higgs boson pair production using 126-140  fb^{-1} of proton-proton collision data at sqrt[s]=13  TeV recorded with the ATLAS detector. At 95% confidence level (CL), the upper limit on the production rate is 2.9 times the standard model (SM) prediction, with an expected limit of 2.

Studies of the Energy Dependence of Diboson Polarization Fractions and the Radiation-Amplitude-Zero Effect in WZ Production with the ATLAS Detector.

This Letter presents the first study of the energy dependence of diboson polarization fractions in WZ→ℓνℓ^{'}ℓ^{'}(ℓ,ℓ^{'}=e,μ) production. The dataset used corresponds to an integrated luminosity of 140  fb^{-1} of proton-proton collisions at a center-of-mass energy of 13 TeV recorded by the ATLAS detector. Two fiducial regions with an enhanced presence of events featuring two longitudinally polarized bosons are defined.

Assessment of arsenic immobilization in synthetically prepared cemented paste backfill specimens.

Mine tailings coming from the exploitation of sulphide and/or gold deposits can contain significant amounts of arsenic (As), highly soluble in conditions of weathering. Open mine voids backfilling techniques are now widely practiced by modern mining companies to manage the tailings. The most common one is called cemented paste backfill (CPB), and consists of tailings mixed with low amounts of hydraulic binders (3-5%) and a high proportion of water (typically 25%).

Arsenic stability in arsenopyrite-rich cemented paste backfills: a leaching test-based assessment.

Arsenic (As) is a toxicant in tailings from sulphur deposits. It represents an environmental risk because of its high solubility. Tailings can be mixed with water (typically 25%) and a low proportion of hydraulic binder (3-7%) to produce a cemented paste backfill (CPB), stored in underground mine openings.

Modelling and simulation of concrete leaching under outdoor exposure conditions.

Recently, a demand regarding the assessment of release of dangerous substances from construction products was raised by European Commission which has issued the Mandate M/366 addressed to CEN. This action is in relation with the Essential Requirement No. 3 "Hygiene, Health and Environment" of the Construction Products Directive (89/106/EC).

Pollutants leaching behaviour from solidified wastes: a selection of adapted various models.

Leaching tests are essential in the environmental assessment of stabilized wastes. Research programmes were conducted on their interpretation in order to develop tools for the evaluation of long term release of pollutants contained in solidified wastes. Models for the leaching of porous materials are discussed in this paper according to the specificity of the chemical species (i.

Multiple-scale dynamic leaching of a municipal solid waste incineration ash.

Predicting the impact on the subsurface and groundwater of a pollutant source, such as municipal solid waste (MSW) incineration ash, requires a knowledge of the so-called "source term". The source term describes the manner in which concentrations in dissolved elements in water percolating through waste evolve over time, for a given percolation scenario (infiltration rate, waste source dimensions, etc.).

Horizontal environmental assessment of building products in relation to the construction products directive (CPD).

According to the European Construction Products Directive (89/106/EC), construction products must satisfy specified essential requirements (ER). To comply with ER 3, on hygiene, health and environment, the construction works must be designed and built in such a way that they will not be a threat to the hygiene and health of the occupants and neighbours, nor to the environment. Standardised test methods for the release of substances that are hazardous to health and environment need to be developed at the European level.

Experimental percolation under intermittent conditions: influence on pollutants emission from waste.

As a precautionary measure, the re-use (or landfill) of waste requires an environmental assessment of its potential impact. This assessment is usually made by simulating the emission of pollutants with a predictive model based on laboratory tests (standardised batch leaching tests, up-flow percolation tests, acid neutralisation capacity tests [CEN, Characterisation of Waste--Leaching--Compliance Test for Leaching of Granular Waste Materials and Sludges, European Committee for Standardisation (ECS), Brussels, 2002 ; CEN, prCEN/TS 14405 Characterisation of Waste--Leaching Behaviour Tests--Up-flow Percolation Test (under specified conditions), ECS, Brussels, 2002 ; CEN, prCEN/TS 14429 Characterisation of Waste--Leaching Behaviour Test--Influence of pH on Leaching with Initial Acid/base Addition, ECS, Brussels, 2003 ]. These tests are performed with simpler conditions than those occurring in the scenario of re-use (saturated media, permanent inflow .

Effect of experimentally induced reducing conditions on the mobility of arsenic from a mining soil.

A method for estimating the release of contaminants from contaminated sites under reducing conditions is proposed. The ability of two chemical reducing agents, sodium ascorbate and sodium borohydride, to produce different redox environments in a gold mining soil contaminated with arsenic was investigated. Liquid-solid partitioning experiments were carried out in the presence of each of the reducing agents at different pH conditions.

Effect of indigenous bacterial activity on arsenic mobilization under anaerobic conditions.

Batch biochemical leaching tests were carried out to investigate the mobility of arsenic from a contaminated soil collected from a French gold mining site. The specific objective of this research was to examine the effect of indigenous bacterial activity on arsenic mobilization under anaerobic conditions. In a first step, physical and chemical characterizations were performed to provide data concerning the liquid-solid partitioning and mobility of arsenic and other inorganic constituents.

Leaching assessment of road materials containing primary lead and zinc slags.

Characterisation of the leaching behaviour of waste-containing materials is a crucial step in the environmental assessment for reuse scenarios. In our research we applied the multi-step European methodology ENV 12-920 to the leaching assessment of road materials containing metallurgical slag. A Zn slag from an imperial smelting furnace (ISF) and a Pb slag from a lead blast furnace (LBF) are investigated.

Environmental assessment of waste matrices contaminated with arsenic.

The use of equilibrium-based and mass transfer-based leaching tests has been proposed to provide an integrated assessment of leaching processes from solid wastes. The objectives of the research presented here are to (i) validate this assessment approach for contaminated soils and cement-based matrices, (ii) evaluate the use of diffusion and coupled dissolution-diffusion models for estimating constituent release, and (iii) evaluate model parameterization using results from batch equilibrium leaching tests and physical characterization. The test matrices consisted of (i) a soil contaminated with arsenic from a pesticide production facility, (ii) the same soil subsequently treated by a Portland cement stabilization/solidification (S/S) process, and (iii) a synthetic cement-based matrix spiked with arsenic(III) oxide.

The effect of storage in an inert atmosphere on the release of inorganic constituents during intermittent wetting of a cement-based material.

Monolithic waste materials (e.g. Portland cement treated wastes) in many field scenarios do not remain continuously saturated, but experience intermittent wetting interspersed with periods of storage in an unsaturated environment.

Modeling of solid/liquid/gas mass transfer for environmental evaluation of cement-based solidified waste.

A physicochemical and transport model has been developed for the long term prediction of environmental leaching behavior of porous materials containing inorganic waste solidified with hydraulic binders and placed in a reuse scenario. The reuse scenario considered in the paper is a storage tank open to the atmosphere including material leaching with water and carbonation through the leachate contact with air. The model includes three levels: (i) the physicochemical pollution source term (chemical equilibria in the pore water and diffusion in the porous system); (ii) chemical equilibria and mass transfer in the tank; and (iii) gas/liquid transfer of carbon dioxide.