16 resultados para Sulphur dioxide
em Université de Lausanne, Switzerland
Formulation and Implementation of Air Quality Control Pogrammes : Patterns of Interest Consideration
Resumo:
This article investigates some central aspects of the relationships between programme structure and implementation of sulphur dioxide air quality control policies. Previous implementation research, primarily adopting American approaches, has neglected the connections between the processes of programme formulation and implementation. 'Programme', as the key variable in implementation studies, has been defined too narrowly. On the basis of theoretical and conceptual reflections and provisional empirical results from studies in France, Italy, England, and the Federal Republic of Germany, the authors demonstrate that an integral process analysis using a more extended programme concept is necessary if patterns of interest recognition in policies are to be discovered. Otherwise, the still important question of critical social science cannot be answered, namely, what is the impact of special interests upon implementation processes.
Resumo:
General Summary Although the chapters of this thesis address a variety of issues, the principal aim is common: test economic ideas in an international economic context. The intention has been to supply empirical findings using the largest suitable data sets and making use of the most appropriate empirical techniques. This thesis can roughly be divided into two parts: the first one, corresponding to the first two chapters, investigates the link between trade and the environment, the second one, the last three chapters, is related to economic geography issues. Environmental problems are omnipresent in the daily press nowadays and one of the arguments put forward is that globalisation causes severe environmental problems through the reallocation of investments and production to countries with less stringent environmental regulations. A measure of the amplitude of this undesirable effect is provided in the first part. The third and the fourth chapters explore the productivity effects of agglomeration. The computed spillover effects between different sectors indicate how cluster-formation might be productivity enhancing. The last chapter is not about how to better understand the world but how to measure it and it was just a great pleasure to work on it. "The Economist" writes every week about the impressive population and economic growth observed in China and India, and everybody agrees that the world's center of gravity has shifted. But by how much and how fast did it shift? An answer is given in the last part, which proposes a global measure for the location of world production and allows to visualize our results in Google Earth. A short summary of each of the five chapters is provided below. The first chapter, entitled "Unraveling the World-Wide Pollution-Haven Effect" investigates the relative strength of the pollution haven effect (PH, comparative advantage in dirty products due to differences in environmental regulation) and the factor endowment effect (FE, comparative advantage in dirty, capital intensive products due to differences in endowments). We compute the pollution content of imports using the IPPS coefficients (for three pollutants, namely biological oxygen demand, sulphur dioxide and toxic pollution intensity for all manufacturing sectors) provided by the World Bank and use a gravity-type framework to isolate the two above mentioned effects. Our study covers 48 countries that can be classified into 29 Southern and 19 Northern countries and uses the lead content of gasoline as proxy for environmental stringency. For North-South trade we find significant PH and FE effects going in the expected, opposite directions and being of similar magnitude. However, when looking at world trade, the effects become very small because of the high North-North trade share, where we have no a priori expectations about the signs of these effects. Therefore popular fears about the trade effects of differences in environmental regulations might by exaggerated. The second chapter is entitled "Is trade bad for the Environment? Decomposing worldwide SO2 emissions, 1990-2000". First we construct a novel and large database containing reasonable estimates of SO2 emission intensities per unit labor that vary across countries, periods and manufacturing sectors. Then we use these original data (covering 31 developed and 31 developing countries) to decompose the worldwide SO2 emissions into the three well known dynamic effects (scale, technique and composition effect). We find that the positive scale (+9,5%) and the negative technique (-12.5%) effect are the main driving forces of emission changes. Composition effects between countries and sectors are smaller, both negative and of similar magnitude (-3.5% each). Given that trade matters via the composition effects this means that trade reduces total emissions. We next construct, in a first experiment, a hypothetical world where no trade happens, i.e. each country produces its imports at home and does no longer produce its exports. The difference between the actual and this no-trade world allows us (under the omission of price effects) to compute a static first-order trade effect. The latter now increases total world emissions because it allows, on average, dirty countries to specialize in dirty products. However, this effect is smaller (3.5%) in 2000 than in 1990 (10%), in line with the negative dynamic composition effect identified in the previous exercise. We then propose a second experiment, comparing effective emissions with the maximum or minimum possible level of SO2 emissions. These hypothetical levels of emissions are obtained by reallocating labour accordingly across sectors within each country (under the country-employment and the world industry-production constraints). Using linear programming techniques, we show that emissions are reduced by 90% with respect to the worst case, but that they could still be reduced further by another 80% if emissions were to be minimized. The findings from this chapter go together with those from chapter one in the sense that trade-induced composition effect do not seem to be the main source of pollution, at least in the recent past. Going now to the economic geography part of this thesis, the third chapter, entitled "A Dynamic Model with Sectoral Agglomeration Effects" consists of a short note that derives the theoretical model estimated in the fourth chapter. The derivation is directly based on the multi-regional framework by Ciccone (2002) but extends it in order to include sectoral disaggregation and a temporal dimension. This allows us formally to write present productivity as a function of past productivity and other contemporaneous and past control variables. The fourth chapter entitled "Sectoral Agglomeration Effects in a Panel of European Regions" takes the final equation derived in chapter three to the data. We investigate the empirical link between density and labour productivity based on regional data (245 NUTS-2 regions over the period 1980-2003). Using dynamic panel techniques allows us to control for the possible endogeneity of density and for region specific effects. We find a positive long run elasticity of density with respect to labour productivity of about 13%. When using data at the sectoral level it seems that positive cross-sector and negative own-sector externalities are present in manufacturing while financial services display strong positive own-sector effects. The fifth and last chapter entitled "Is the World's Economic Center of Gravity Already in Asia?" computes the world economic, demographic and geographic center of gravity for 1975-2004 and compares them. Based on data for the largest cities in the world and using the physical concept of center of mass, we find that the world's economic center of gravity is still located in Europe, even though there is a clear shift towards Asia. To sum up, this thesis makes three main contributions. First, it provides new estimates of orders of magnitudes for the role of trade in the globalisation and environment debate. Second, it computes reliable and disaggregated elasticities for the effect of density on labour productivity in European regions. Third, it allows us, in a geometrically rigorous way, to track the path of the world's economic center of gravity.
Resumo:
A novel approach to measure carbon dioxide (CO2) in gaseous samples, based on a precise and accurate quantification by (13)CO2 internal standard generated in situ is presented. The main goal of this study was to provide an innovative headspace-gas chromatography-mass spectrometry (HS-GC-MS) method applicable in the routine determination of CO2. The main drawback of the GC methods discussed in the literature for CO2 measurement is the lack of a specific internal standard necessary to perform quantification. CO2 measurement is still quantified by external calibration without taking into account analytical problems which can often occur considering gaseous samples. To avoid the manipulation of a stable isotope-labeled gas, we have chosen to generate in situ an internal labeled standard gas ((13)CO2) on the basis of the stoichiometric formation of CO2 by the reaction of hydrochloric acid (HCl) with sodium hydrogen carbonate (NaH(13)CO3). This method allows a precise measurement of CO2 concentration and was validated on various human postmortem gas samples in order to study its efficiency.
Resumo:
A continuum of carbon, from atmospheric CO2 to secondary calcium carbonate, has been studied in a soil associ- ated with scree slope deposits in the Jura Mountains of Switzerland. This approach is based on former studies conducted in other environments. This C continuum includes atmospheric CO2, soil organic matter (SOM), soil CO2, dissolved inorganic carbon (DIC) in soil solutions, and secondary pedogenic carbonate. Soil parameters (pCO2, temperature, pH, Cmin and Corg contents), soil solution chemistry, and isotopic compositions of soil CO2, DIC, carbonate and soil organic matter (δ13CCO2, δ13CDIC, δ13Ccar and δ13CSOM values) have been monitored at different depths (from 20 to 140 cm) over one year. Results demonstrated that the carbon source in secondary carbonate (mainly needle fiber calcite) is related to the dissolved inorganic carbon, which is strongly dependent on soil respiration. The heterotrophic respiration, rather than the limestone parent material, seems to control the pedogenic carbon cycle. The correlation of δ13Corg values with Rock-Eval HI and OI indices demonstrates that, in a soil associated to scree slope deposits, the main process responsible for 13C-enrichment in SOM is related to bac- terial oxidative decarboxylation. Finally, precipitation of secondary calcium carbonate is enhanced by changes in soil pCO2 associated to the convective movement of air masses induced by temperature gradients (heat pump effect) in the highly porous scree slope deposits. The exportation of soil C-leachates from systems such as the one studied in this paper could partially explain the "gap in the European carbon budget" reported by recent studies.
Resumo:
Rosickyite, the natural monoclinic gamma -form of sulphur, exists in only a few localities around the globe. In the old asphalt mine at La Presta, Neuchatel. Switzerland, rosickyite occurs locally as small, but very well formed crystals suitable for crystallographic studies. It grows as an alteration product of pyrite-rich asphalt. Rosickyite from La Presta mine is pure molecular sulphur, as revealed by gas chromatography-mass spectrometry. The X-ray powder diffraction data of La Presta rosickyite does not match the one previously published for this species. Therefore, a single crystal study was undertaken and a new indexed X-ray powder diffraction diagram for natural rosickyite is proposed.
Resumo:
Whereas during the last few years handling of the transcutaneous PO2 (tcPO2) and PCO2 (tcPCO2) sensor has been simplified, the high electrode temperature and the short application time remain major drawbacks. In order to determine whether the application of a topical metabolic inhibitor allows reliable measurement at a sensor temperature of 42 degrees C for a period of up to 12 h, we performed a prospective, open, nonrandomized study in a sequential sample of 20 critically ill neonates. A total of 120 comparisons (six repeated measurements per patient) between arterial and transcutaneous values were obtained. Transcutaneous values were measured with a control sensor at 44 degrees C (conventional contact medium, average application time 3 h) and a test sensor at 42 degrees C (Eugenol solution, average application time 8 h). Comparison of tcPO2 and PaO2 at 42 degrees C (Eugenol solution) showed a mean difference of +0.16 kPa (range +1.60 to -2.00 kPa), limits of agreement +1.88 and -1.56 kPa. Comparison of tcPO2 and PaO2 at 44 degrees C (control sensor) revealed a mean difference of +0.02 kPa (range +2.60 to -1.90 kPa), limits of agreement +2.12 and -2.08 kPa. Comparison of tcPCO2 and PaCO2 at 42 degrees C (Eugenol solution) showed a mean difference of +0.91 (range +2.30 to +0.10 kPa), limits of agreement +2.24 and -0.42 kPa. Comparison of tcPCO2 and PaCO2 at 44 degrees C (control sensor) revealed a mean difference of +0.63 kPa (range 1.50 to -0.30 kPa), limits of agreement +1.73 and -0.47 kPa. CONCLUSION: Our results show that the use of an Eugenol solution allows reliable measurement of tcPO2 at a heating temperature of 42 degrees C; the application time can be prolongued up to a maximum of 12 h without aggravating the skin lesions. The performance of the tcPCO2 monitor was slightly worse at 42 degrees C than at 44 degrees C suggesting that for the Eugenol solution the metabolic offset should be corrected.
Resumo:
Saffaj et al. recently criticized our method of monitoring carbon dioxide in human postmortem cardiac gas samples using Headspace-Gas Chromatography-Mass Spectrometry. According to the authors, their demonstration, based on the latest SFSTP guidelines (established after 2007 [1,2]) fitted for the validation of drug monitoring bioanalytical methods, has put in evidence potential errors. However, our validation approach was built using SFSTP guidelines established before 2007 [3-6]. We justify the use of these guidelines because of the post-mortem context of the study (and not clinical) and the gaseous state of the sample (and not solid or liquid). Using these guidelines, our validation remains correct.
Resumo:
In 58 newborn infants a new iridium oxide sensor was evaluated for transcutaneous carbon dioxide (tcPCO2) monitoring at 42 degrees C with a prolonged fixation time of 24 hours. The correlation of tcPCO2 (y; mm Hg) v PaCO2 (x; mm Hg) for 586 paired values was: y = 4.6 + 1.45x; r = .89; syx = 6.1 mm Hg. The correlation was not influenced by the duration of fixation. The transcutaneous sensor detected hypocapnia (PaCO2 less than 35 mm Hg) in 74% and hypercapnia (PCO2 greater than 45 mm Hg) in 74% of all cases. After 24 hours, calibration shifts were less than 4 mm Hg in 90% of the measuring periods. In 86% of the infants, no skin changes were observed; in 12% of infants, there were transitional skin erythemas and in 2% a blister which disappeared without scarring. In newborn infants with normal BPs, continuous tcPCO2 monitoring at 42 degrees C can be extended for as many as 24 hours without loss of reliability or increased risk for skin burns.
Resumo:
IMPLICATIONS: A new combined ear sensor was tested for accuracy in 20 critically ill children. It provides noninvasive and continuous monitoring of arterial oxygen saturation, arterial carbon dioxide tension, and pulse rate. The sensor proved to be clinically accurate in the tested range.
Resumo:
Many routes have been described for percutaneous adrenal gland biopsy. They require either a complex non-axial path or a long hydrodissection or even pass through an organ thereby increasing complications. We describe here an approach using an artificially-induced carbon dioxide (CO2) pneumothorax, performed as an outpatient procedure in a 57-year-old woman. Under local anaesthesia, 200 ml of CO2 was injected in the pleural space through a Veress needle under computed tomography fluoroscopy, to clear the lung parenchyma from the biopsy route. Using this technique, transthoracic adrenal biopsy can be performed under simple local anaesthesia as an safely outpatient procedure.
Resumo:
We evaluated a new combined sensor for monitoring transcutaneous carbon dioxide tension (PtcCO2) and oxygen tension (PtcO2) in 20 critically ill newborn infants. Arterial oxygen tension (PaO2) ranged from 16 to 126 torr and arterial carbon dioxide tension (PaCO2) from 14 to 72 torr. Linear correlation analysis (100 paired values) of PtcO2 versus PaO2 showed an r value of 0.75 with a regression equation of PtcO2 = 8.59 + 0.905 (PaO2), while PtcCO2 versus PaCO2 revealed a correlation coefficient of r = 0.89 with an equation of PtcCO2 = 2.53 + 1.06 (PaCO2). The bias between PaO2 and PtcO2 was -2.8 with a precision of +/- 16.0 torr (range, -87 to +48 torr). The bias between PaCO2 and PtcCO2 was -5.1 with a precision of +/- 7.3 torr (range, -34 to +8 torr). The transcutaneous sensor detected 83% of hypoxia (PaO2 less than 45 torr), 75% of hyperoxia (PaO2 greater than 90 torr), 45% of hypocapnia (PaCO2 less than 35 torr), and 96% of hypercapnia (PaCO2 greater than 45 torr). We conclude that the reliability of the combined transcutaneous PO2 and PCO2 monitor in sick neonates is good for detecting hypercapnia, fair for hypoxia and hyperoxia, but poor for hypocapnia. It is an improvement in that it spares available skin surface and requires less handling, but it appears to be slightly less accurate than the single electrodes.
Resumo:
In a prospective investigation of 17 children with severe croup, we analyzed the effect of epinephrine inhalations and mild sedation with chloral hydrate on transcutaneous carbon dioxide pressure (tcPCO2), pulse oximetry measurements, and croup scores. There was a highly significant reduction (p less than 0.001) in the tcPCO2 values and croup scores after inhalation of epinephrine. The changes in the tcPCO2 values correlated with the clinical findings. Mild sedation also significantly improved the croup scores but failed to influence the tcPCO2 values. There was not statistically significant difference in pulse oximetry saturation, fraction of administered oxygen, heart rate, or respiratory rate before and after inhalation of epinephrine or chloral hydrate administration. Monitoring tcPCO2 appears to be a reliable and objective tool for managing patients with upper airway obstruction, whereas croup scores may be misleading.