Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 13 de 13
Filter
1.
J Environ Manage ; 168: 36-45, 2016 Mar 01.
Article in English | MEDLINE | ID: mdl-26696604

ABSTRACT

Globally, efforts are underway to reduce anthropogenic greenhouse gas emissions and to adapt to climate change impacts at the local level. However, there is a poor understanding of the relationship between city strategies on climate change mitigation and adaptation and the relevant policies at national and European level. This paper describes a comparative study and evaluation of cross-national policy. It reports the findings of studying the climate change strategies or plans from 200 European cities from Austria, Belgium, Estonia, Finland, France, Germany, Ireland, Italy, Netherlands, Spain and the United Kingdom. The study highlights the shared responsibility of global, European, national, regional and city policies. An interpretation and illustration of the influences from international and national networks and policy makers in stimulating the development of local strategies and actions is proposed. It was found that there is no archetypical way of planning for climate change, and multiple interests and motivations are inevitable. Our research warrants the need for a multi-scale approach to climate policy in the future, mainly ensuring sufficient capacity and resource to enable local authorities to plan and respond to their specific climate change agenda for maximising the management potentials for translating environmental challenges into opportunities.


Subject(s)
Cities , Climate Change , Policy Making , Europe , Humans , Urbanization
2.
Ultrason Sonochem ; 27: 430-439, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26186864

ABSTRACT

Beachrocks are consolidated coastal sedimentary formations resulting mainly from the relative rapid cementation of beach sediments by different calcium carbonate polymorphs. Although previous works have already studied the elemental composition and the mineral phases composing these cements, few of them have focused their attention on the organic matter present therein. This work describes an extraction methodology based on focused ultrasound solid-liquid extraction (FUSLE), followed by analysis using large volume injection (LVI) in a programmable temperature vaporizer (PTV) combined with gas chromatography-mass spectrometry (GC-MS) in order to determine organics such as polycyclic aromatic hydrocarbons (PAHs) and biomarkers (hopanes), which can increase and confirm the information obtained so far. This goal has been achieved after the optimization of the main parameters affecting the extraction procedure, such as, extraction solvent, FUSLE variables (amplitude, extraction time and pulse time) and also variables affecting the LVI-PTV (vent time, injection speed and cryo-focusing temperature). The developed method rendered results comparable to traditional extraction methods in terms of accuracy (77-109%) and repeatability (RSD<23%). Finally, the analyses performed over real beachrock samples from the Bay of Biscay (Northern Spain) revealed the presence of the 16 EPA priority PAHs, as well as some organic biomarkers which could increase the knowledge about such beachrock formation.


Subject(s)
Chemical Fractionation/methods , Geologic Sediments/chemistry , Organic Chemicals/isolation & purification , Ultrasonic Waves , Quality Control , Sulfur/chemistry , Time Factors
3.
Environ Sci Pollut Res Int ; 21(21): 12518-29, 2014 Nov.
Article in English | MEDLINE | ID: mdl-24946700

ABSTRACT

The relevance of a risk assessment of the built heritage was clearly justified due to the fact that it acts as a pollutant repository and hazardous pollutants have the capacity to penetrate into materials. However, the limitation of the sampling processes due to the high value of the built heritage makes a correct evaluation difficult. For that reason, in the present work, the potential of agar gels as non-invasive samplers of built heritage deterioration products, like crusts and patinas, was evaluated. Different gels of agar and Carbopol® (as control gel) were applied on these built surfaces considering several factors: the treatment time, the effectiveness of the addition of EDTA (ethylenediaminetetraacetic acid, C10H16N2O8) and its concentration and the use of a buffer at pH 7.5. All these factors were evaluated in order to determine the capacity of these gels as sampling systems under non-controlled atmospheric conditions. The results obtained in the assays were evaluated by visual examination, by evolution of pH and by the most important techniques used in the risk assessment analysis of the built heritage (Raman spectroscopy, scanning electron microscope (SEM)/energy dispersive X-ray (EDX) and inductively coupled plasma mass spectrometry (ICP-MS)). In this evaluation, the agar gels showed an intrinsic capacity as sampler with respect to the gel Carbopol® and thus, the best option between the studied gels consisted on agar gels with 2 % of EDTA and the longest application time. On the whole, the agar gels showed an interesting potential as non-invasive samplers of built heritage deterioration materials which should be studied more in depth.


Subject(s)
Construction Materials/analysis , Environmental Monitoring/methods , Environmental Pollutants/analysis , Agar/chemistry , Edetic Acid/chemistry , Gels , Hydrogen-Ion Concentration , Limit of Detection , Microscopy, Electron, Scanning , Risk Assessment , Spectrometry, X-Ray Emission , Spectrum Analysis, Raman
4.
J Hazard Mater ; 248-249: 451-60, 2013 Mar 15.
Article in English | MEDLINE | ID: mdl-23416873

ABSTRACT

In the present work the pollutant content of diverse building materials was evaluated by the combination of spectrometric and chromatographic techniques. A first non-destructive analysis carried out by µ-XRF and Raman spectroscopy revealed a high impact of pollutants, which reached depths higher than 6mm. The quantitative analyses pointed out that black crust as accumulation nucleus where concentration values up to 3408 mg/kg of lead, 752 mg/kg of chromium or 220 mg/kg of arsenic, high amounts of diverse sulphates and nitrates as well as substantial amounts of polycyclic aromatic hydrocarbons (PAHs) of a clear pyrolytic source were determined. On the other hand, samples without black crust showed also a surprising soluble salt content up to 5%. Polychlorinated biphenyls (PCB) were found to be absent in all material types. The chemometric analysis of the quantitative results revealed that the accumulation capacity and the subsequent pollutant content depends on the type of construction materials, being mortars the most susceptible.


Subject(s)
Air Pollutants/analysis , Construction Materials/analysis , Arsenic/analysis , Environmental Monitoring , Metals/analysis , Polychlorinated Biphenyls/analysis , Polycyclic Aromatic Hydrocarbons/analysis , Salts/analysis , Spain
5.
Ultrason Sonochem ; 19(6): 1260-5, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22472497

ABSTRACT

The Italian recommendation NORMAL 13/83, later replaced by the UNI 11087/2003 norm, were used as standard for soluble salts extraction from construction materials. These standards are based on long-time stirring (72 and 2h, respectively) of the sample in deionized water. In this work two ultrasound based methods were optimized in order to reduce the extraction time while efficiency is improved. The instrumental variables involved in the extraction assisted by ultrasound bath and focused ultrasounds were optimized by experimental design. As long as it was possible, the same non-instrumental parameters values as those of standard methods were used in order to compare the results obtained on a mortar sample showing a black crust by the standards and the optimized methods. The optimal extraction time for the ultrasounds bath was found to be of two hours. Although the extraction time was equal to the standard UNI 11087/2003, the obtained extraction recovery was improved up to 119%. The focused ultrasound system achieved also better recoveries (up to 106%) depending on the analyte in 1h treatment time. The repeatabilities of the proposed ultrasound based methods were comparables to those of the standards. Therefore, the selection of one or the other of the ultrasound based methods will depend on topics such as laboratory facilities or number of samples, and not in aspects related with their quality parameters.

6.
Anal Bioanal Chem ; 399(9): 2949-59, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21057778

ABSTRACT

A multianalytical characterisation of black crusted modern construction materials from buildings located in the Bilbao Metropolitan area (North Spain) was carried out. According to the mineral composition determined by Raman spectroscopy, calcite and hematite were the major compounds found while aragonite, limonite, rutile, quartz and some aluminosilicates such as obsidian or amazonite (KAlSi(3)O(8)) were also present in minor percentages. As deterioration products, gypsum and anhydrite were widely found not only in the surface but also in the inner part of strongly deteriorated samples. Coquimbite (Fe(2)(SO(4))(3)·9H(2)O) was identified as well in the most protected facade where high amounts of Fe, having probably an anthropogenic origin, were measured by micro X-ray fluorescence (µ-XRF). Zn was found to be in high amounts while Cu, Pb, Ti, Mn, Sr and K were identified as minor elements. Considering the non-expected concentrations found for some anthropogenic elements, a sequential extraction was carried out in order to determine their chemical form by means of ion chromatography and inductively coupled plasma mass spectrometry. The orientation of the facades, which had a different influence from rain washing and industrial and traffic impact, was shown to affect the accumulation of different compounds in the black crust. Finally, the MEDUSA software was used to simulate the reactions among the original compounds, deposited pollutants and the atmospheric acid gases in order to explain the presence of the decaying species found.

7.
Gac méd espirit ; 9(2)mayo-ago.,2007.
Article in Spanish | CUMED | ID: cum-35527

ABSTRACT

La carga inmediata constituye un paso más en la evolución de la rehabilitación implantológica, ya que aporta ventajas sobre los métodos convencionales de carga, que se resumen en: acortamiento de los tiempos de tratamiento, preservación de los tejidos blandos y un rápido restablecimiento de la estética en el paciente. La mayor parte de los estudios de carga inmediata muestran una tasa de éxito superior cuando los implantes unitarios son cargados inmediatamente y rehabilitados a través de un puente fijo , sin tallar dientes vecinos ; Por ello, el objetivo de este trabajo es la presentación de un caso desdentado parcialmente, con ligeras afectaciones periodontales y daños reversibles en la mucosa palatina, causados por la aparatología parcial removible ; logrando como beneficios una distribución homogénea de las cargas sobre el hueso, contorno óseo adecuado y un mayor confor. [AU]


Subject(s)
Mouth Rehabilitation , Dental Implants
8.
Anal Chim Acta ; 584(2): 350-9, 2007 Feb 19.
Article in English | MEDLINE | ID: mdl-17386625

ABSTRACT

Raman microprobe spectroscopy and microX-ray fluorescence were used to analyse the original composition and degradation products of the limestone and the sandstones from the facades of one historical building. Carbon particles, gypsum (CaSO(4).2H(2)O) and some nitrate compounds were determined by Raman measurements, while elemental characterisation carried out by microXRF revealed the presence of lead, sulphur and copper as pollutants. On the one hand, the grey sandstone is the most deteriorated and in some cases pollutants reach 3 cm depth. On the other hand, quantification of soluble salts (chlorides, sulphates, nitrates, nitrites, fluorides and carbonates) was accomplished by ion chromatography. Chloride and sulphates are not significant soluble salts in the façades of the building, but the amount of nitrate is even 136 g kg(-1) in some of the most deteriorated samples and of 147 g kg(-1) in black-crusts. Finally, organic compounds (mainly PAHs) were characterised by GC-MS. Concentrations higher than 20 ppm of total PAHs were measured in the black-crusts of the rain-protected facades. The presence of certain PAHs indicated combustion of fuels as the main source of deterioration for the palace house building materials.


Subject(s)
Air Pollutants/analysis , Construction Materials , Calcium Carbonate , Chromatography , Gas Chromatography-Mass Spectrometry , Housing , Metals/analysis , Polycyclic Aromatic Hydrocarbons/analysis , Spain , Spectrometry, X-Ray Emission , Spectrum Analysis, Raman
9.
Anal Bioanal Chem ; 379(1): 42-50, 2004 May.
Article in English | MEDLINE | ID: mdl-14758463

ABSTRACT

This work reports the use of a portable Raman microprobe spectrometer for the analysis of bulk and decaying compounds in carbonaceous materials such as stones, mortars and wall paintings. The analysed stones include limestone, dolomite and carbonaceous sandstone, gypsum and calcium oxalate, both mono- and dihydrated, being the main inorganic degradation products detected. Mortars include bulk phases with pure gypsum, calcite and mixtures of both or with sand, soluble salts being the most important degradation products. The pigments detected in several wall paintings include Prussian blue, iron oxide red, iron oxide yellow, vermilion, carbon black and lead white. Three different decaying processes have been characterised in the mortars of the wall paintings: (a) a massive absorption of nitrates that reacted with calcium carbonate and promoted the unbinding of pigment grains, (b) the formation of black crusts in the vault of the presbytery and (c) the thermodecomposition of pigments due to a fire.

11.
Talanta ; 44(5): 891-6, 1997 May.
Article in English | MEDLINE | ID: mdl-18966817

ABSTRACT

The protonation equilibrium of the Tris(Hydroxymethyl)aminomethane (TRIS) has been studied using an automated potentiometric system. The temperature was kept constant at 25 degrees C and the ionic strength was 0.1, 0.5, 1.0, 2.0 and 3.0 mol dm(-3) in NaClO(4). The experimental constants, obtained at different ionic strengths, were correlated by means of the modified Bromley methodology (MBM) and the thermodynamic protonation constant found to be log (0)beta = 8.07 +/- 0.01 . Those values together with some others for NaCl medium were used to construct a thermodynamic model on both molal and molar scales for the protonation equilibrium of TRIS.

12.
Biochem Biophys Res Commun ; 152(1): 113-21, 1988 Apr 15.
Article in English | MEDLINE | ID: mdl-3358755

ABSTRACT

Lactobacillus leichmanii growing in complex medium supplemented with decanoic acid accumulated high concentrations of hydrogen peroxide in the culture. The H2O2-generating system was specifically induced by one of the saturated fatty acids from 4:0 to 16:0 or oleic acid. The induction of this system was associated with the presence of a fatty acyl-CoA-dependent H2O2-generating activity in the cell-free extracts. This activity is shown for the first time in a procaryote organism.


Subject(s)
Hydrogen Peroxide/metabolism , Lactobacillus/metabolism , Decanoic Acids/pharmacology , Kinetics , Lactobacillus/drug effects , Lactobacillus/growth & development
SELECTION OF CITATIONS
SEARCH DETAIL
...