Search results for "CO2"

TERRE project: interplay between unsaturated soil mechanics and low-carbon geotechnical engineering

2020

The geotechnical construction industry is a major component of the overall construction sector and is strategically important in infrastructure development (transportation, flood and landslide protection, building foundations, waste disposal). Although industry and research in the overall construction sector have been investing significantly in recent years to produce innovative low-carbon technologies, little innovation has been created in geotechnical construction industry, which is lagging behind other construction industry sectors. This paper discusses the interplay between low-carbon geotechnical engineering and unsaturated soil mechanics based on the research carried out within the pr…

Co2 emissions of French shippers: The roles of delivery frequency and weight, mode choice, and distance

2014

In this article, the authors describe the effects of delivery frequency, mode choice, distance, and shipment weight on the CO₂ emissions of French shippers, taking advantage of a 2004 survey of French shippers (ECHO) which describes the characteristics of 3000 shippers, 10,000 shipments, and 20,000 transport chain legs. Once the energy consumption and CO₂ emissions of every shipment have been computed, they are divided by the corresponding number of ton-kilometers in order to find their carbon intensity (in grams of CO₂ per ton-kilometer). The authors then analyze the latter with respect to a number of selected shipment characteristics: shipment frequency and mode choice (planning choices),…

Ventilation Rates and Unsatisfied Percentage from Indoor CO2 Concentration

2010

This work reports the results of a survey carried out on a hall in a historic building in Palermo (Italy) with the aim of assessing the air quality by means of objective measurement of carbon dioxide (CO2) concentration and its subjective evaluation through a questionnaire. The measured values of CO2 concentration were compared with those evaluated using the Meckler equation under steady-state conditions, having verified necessary parameters such as the constancy of the indoor and outdoor CO2 levels and the uniformity of the CO 2 generation rate for all the occupants. The positive correspondence between measured and calculated results allowed us to utilise, under differing circumstances, t…

Forecasting Etnean eruptions by real-time observations of volcanic gas composition.

2007

It is generally accepted but not experimentally proven that a quantitative prediction of volcanic eruptions is possible from the evaluation of volcanic gas data. By discussing the results of two years of real-time observation of H2O, CO2 and SO2 in volcanic gases from Mt. Etna volcano, we unambiguously demonstrate that increasing CO2/SO2 ratios can allow detecting the pre-eruptive degassing of uprising magmas. Quantitative modeling by the use of a saturation model allows us to relate the pre-eruptive increases of the CO2/SO2 ratio to the refilling of Etna’s shallow conduits with CO2-rich deep-reservoir magmas, leading to pressurization and eruption triggering. The advent of real-time observ…

Contribution to the development of 100% bio-based composites : synthesis of bio-based polyepoxides, supercritical CO2 treatment of hemp fibers and im…

2018

This thesis contributes to the development of 100% bio-based hemp/epoxy composites. Current environmental issues favor the emergence of materials derived from renewable resources such as plant fibres and a wide range of bio-based building-blocks, source of epoxy prepolymers in particular. An intensive investigation of the two constituents (hemp fibres and polyepoxidic matrix) is carried out before the composites manufacturing. Supercritical CO2 treatment is applied to hemp fibres used as reinforcement in composite materials. This treatment, not optimized, leads to better individualization as well as a decrease in the hygroscopic power of the fibres. These aspects, which are essential in ord…

Slight differences in community structure and biodiversity of fish associated to a Cymodocea nodosa meadow in a shallow CO2 vent

2018

Naturally acidified environments are used to test ecological hypotheses about the effects of ocean acidification on complex communities. Here, we used a shallow Mediterranean CO2 vent to study the coastal fish assemblages associated to Cymodocea nodosa seagrass meadows, long-term exposed to high pCO2 / low pH conditions. In particular, by using underwater visual census method, we assessed the structure and the biodiversity of fish assemblages living in a low pH site and in two control sites, in two periods of the year featured by dissimilar seagrass structure. The aim of this study was to test the effect of different pH on fish assemblages mediated by the habitat-forming structural species …

Iekštelpu gaisa piesārņojums pirmsskolas vecuma bērnu izglītības iestādēs

2019

Bakalaura darba “Iekštelpu piesārņojums pirmsskolas vecuma bērnu izglītības iestādēs” analizēts un aprakstīts iekštelpu vides vispārīgs raksturojums un hipotētiskie piesārņojuma avoti. Eksperimentālā daļā veikti oglekļa dioksīda (CO2), cieto daļiņu PM2.5, PM10, formaldehīda (HCHO), gaistošo savienojumu (TVOC) vielu un mikroklimata (temperatūra, relatīvais mitrums) mērījumi. Laika posmā no 2019. gada ziemas līdz 2019. gada pavasarim apmeklētas 3 pirmsskolas izglītības iestādes (PII) – divas Rīgā, Ziepniekkalnā un viena Iecavā. Iegūtie rezultāti salīdzināti ar normatīviem un Pasaules veselības organizācijas (PVO) rekomendējamajiem normatīviem.

Foto-reattori a membrana per la valorizzazione del CO2

2019

In questo lavoro è stata studiata la foto-riduzione del CO2 sotto irraggiamento con luce UV-Visibile, accoppiando per la prima volta la tecnologia del reattore continuo a membrana con l’utilizzo di catalizzatori a base di C3N4 puro o compositi C3N4-TiO2 dispersi in una matrice polimerica di Nafion.

RIDUZIONE FOTOCATALITICA DI CO2 IN SISTEMI GAS-SOLIDO IN PRESENZA DI TiO2 PURO E DROGATO CON RAME

2012

Stimulated Raman-Spectroscopy of the Q-Branch of Nitrogen at High Pressure - Collisional Narrowing and Shifting in the 150-6800 Bar Range at Room Tem…

1992

0026-8976; The Raman Q branch of N2 has been recorded at room temperature in the pressure range 150-6800 bar, which corresponds to densities from 135 to 800 amagat. In this domain, the Raman Q branch profile is mainly determined by the well-known collisional narrowing. The experimental data have been obtained by means of a high resolution stimulated Raman spectrometer. The linewidth and line shift of the band have been accurately measured as functions of the density, and their density dependences have been fitted by polynomials. The minimum of the linewidth and the maximum of the red shift have been clearly observed at respectively 735.8 and 532.3 amagat. The lineshape was found to be Loren…