Search results for "engineering.material"

A LASER-INDUCED FLUORESCENCE (LIF) METHOD FOR MONITORING OXYGEN–ALKALI DELIGNIFICATION OF SOFTWOOD KRAFT PULP

2002

ABSTRACT A laser-induced fluorescence (LIF) method for monitoring the oxygen–alkali delignification of pine (Pinus sylvestris) kraft pulp was tested. The fluorescence intensity of the effluent was found to increase systematically during treatment as the lignin content of the pulp decreased. This emission method, compared, for example, to a UV/Vis absorption method, seems to have potential for large-scale applications. Owing both to the complex chemical nature of the effluent from oxygen–alkali delignification and to the complex nature of the fluorescence method, further work on this method is needed before it can be used for industrial purposes.

Differential copper impact on density, diversity and resistance of adapted culturable bacterial populations according to soil organic status

2010

International audience; The effect of copper on the abundance, diversity and resistance of viable heterotrophic and copper resistant bacterial populations (CuR) was evaluated in soils differing only by their amount and type of organic matter. These soils have been obtained using a vineyard soil that had been subjected to three different organic matter managements (Not Amended (NA) or amended with Straw (S) or Conifer Compost (CC)) in a long term field experiment. Soil microcosms were artificially contaminated with copper (250 mg Cu kg−1 of soil) and incubated for 35 days. Throughout the incubation, a differential copper impact on viable heterotrophic and CuR bacterial enumeration was demons…

Vineyard Compost Supplemented with Trichoderma Harzianum T78 Improve Saline Soil Quality

2016

Design Procedures for Soil-Lime Stabilization for Road and Railway Embankments. Part 1-Review of Design Methods

2012

AbstractWhen selecting the appropriate materials for constructing road infrastructures, an important way for minimizing both the economical and environmental impact is to make use of lime for treating soils that are not suitable for road or railways construction.Advances in lime stabilization technique allowed the successful use of this technique also for improving the bearing capacity of the subgrade, with noticeable savings on both aggregate and disposal charges.In this paper a review of internationally adopted design methods for soil-lime mixture is presented, in order to compare testing methods and requirements of the adopted criteria, as discussed in Part 2.

Environmental analysis of different construction techniques and maintenance activities for a typical local road

2017

Abstract In this paper, considering the sever impact of road infrastructures on both the surrounding environment as well as on the consumption of locally available natural resources, different road construction techniques have been studied and compared, in order to be able to rank the best solution in terms of environmental sustainability. For the aims of this study, a Life Cycle Analysis has been carried out on a road infrastructure with the most representative geometrical characteristics among those widely used in Italy, in suburban areas, with the help of an appropriate software, the PaLATE. The environmental effects due to both the use of recycled materials, such as the Reclaimed Asphal…

Design Procedures for Soil-Lime Stabilization for Road and Railway Embankments. Part 2-Experimental Validation

2012

AbstractAs detailed in Part 1, the most common Italian Technical Specifications refer to different design methodologies for design of lime-soil mixtures, some being quite different from those internationally adopted. Therefore, it seemed appropriate to the Authors to compare these methodologies, via a wide experimental program.It is shown that the Italian methodology of the National Road Agency is different not only from those used in Italy, but also from the main international standards. The experimental results highlight that a revision of that methodology is needed in order to bring it into line with what is prescribed by the European standard.

Are high-temperature fractionations in the solar nebula preserved in highly siderophile element systematics of the Earth's mantle?

2004

The relative abundances of the highly siderophile elements (HSE) Os, Ir, Ru, Pt, Rh, and Pd in relatively pristine lherzolites differ from solar abundance ratios and are several orders of magnitude higher than predicted for equilibrium distribution between metal/silicate (core-mantle). The samples are characterized by a mean Ca/Al ratio of 1.18 ± 0.09 σM and a mean Ca/Si ratio of 0.10 ± 0.01 σM, overlapping with a mean Ca/Al of 1.069 ±  0.044 σM and a mean Ca/Si of 0.081 ± 0.023 σM found in chondrites (Wasson and Kallemeyn 1988). Interestingly, the CI-normalized abundance pattern shows decreasing solar system normalized abundances with increasing condensation temperatures. The abundance of …

Utilisation of barium-modified analcime in sulphate removal: Isotherms, kinetics and thermodynamics studies

2017

Abstract Analcime and commercial zeolite were employed as a precursor for preparing sorbent material for SO42− removal over barium modification. Three sorbents were prepared: barium-modified analcime (ANA-Na-Ba), barium-modified acid-washed analcime (ANA-Ac-Na-Ba) and barium-modified zeolite (ZSM5-Na-Ba). Of the prepared materials, ANA-Ac-Na-Ba was the most efficient sorbent material for SO42− removal, with a maximum sorption uptake of 13.7 mg g−1 at room temperature. Batch sorption experiments were performed to evaluate the effect of initial pH, initial SO42− concentration, sorbent dosage, temperature and contact time of sorption. Several isotherms were applied to describe the experimental…

Novel biomass fly ash-based geopolymeric mortars using lime slaker grits as aggregate for applications in construction: Influence of granulometry and…

2019

Abstract This work discusses the influence of the aggregate granulometry and the binder/aggregate ratio on the engineering properties of novel green geopolymeric mortars. Two wastes generated by a Portuguese Kraft pulp industry are employed to manufacture the material: lime slaker grits (used as aggregate) and biomass fly ash (to partially replace the metakaolin − 70 wt% substitution). The novel geopolymeric mortars could find innovative applications as sustainable construction materials. The studied mix design foresees the use of several grits granulometric ranges and ratios binder/aggregate to discuss workability, water sorptivity, and mechanical performance of the novel mortars. To date,…

Biochar from byproduct to high value added material – A new adsorbent for toxic metal ions removal from aqueous solutions

2018

Abstract An activated biochar coming from pyrolysis of dead Posidonia oceanica residues has been tested as adsorbent material for Cd2+, Pb2+ and Cu2+ ions. The biomass, the activated and the non activated biochars were previously characterized by using several instrumental techniques. The pH of metal ion solution in kinetic and thermodynamic adsorption experiments was fixed at 5 whilst, the dependence on ionic medium, ionic strength and temperature have been evaluated carrying out batch experiments at different experimental conditions. Differential Pulse Anodic Stripping Voltammetry and Inductively Coupled Plasma Optical Emission Spectroscopy have been used to measure the metal ion concentr…