153 research outputs found
An electrothermal vaporization unit with axially focusing convection upstream. Part II: Modeling of the condensation process
A model is presented that describes quantitatively the condensation of analytes in pico- and nanogram masses sampled with electrothermal vaporization (ETV). It presumes that the analyte vapor condensation of such low amounts occurs mainly heterogeneously, predominantly on growing carbon particulates originating from the graphite furnace before the analyte vapor achieves saturation via cooling. The model regards the coagulation of carbon particles and the diffusion of analyte atoms. The criterion whether or not an analyte atom sticks to a colliding particle is chosen as a function depending on its temperature and on the common GFAAS pretreatment temperatures. Heterogeneous condensation of six analytes with different volatilities, Ag, Cu, Fe, Ni, Mn, and Pb, is calculated for the ETV unit with an axially focusing convection upstream described in Part I. Modifier effects are taken into account. The results are compared to measured data. © 2006 Elsevier B.V. All rights reserved
Elite opinion and foreign policy in post-communist Russia
Russian elite opinion on matters of foreign policy may be classified as âLiberal Westerniserâ, âPragmatic Nationalistâ and âFundamentalist Nationalistâ, terms that reflect longstanding debates about the countryâs relationship with the outside world. An analysis of press
statements and election manifestoes together with a programme of elite interviews between 2004 and 2006 suggests a clustering of opinion on a series of strategic issues. Liberal Westernisers seek the closest possible relationship with Europe, and favour eventual membership of the EU and NATO. Pragmatic Nationalists are more inclined to favour practical co-operation, and do not assume an identity of values or interests with the Western countries. Fundamentalist Nationalists place more emphasis on the other former Soviet republics, and on Asia as much as Europe, and see the West as a threat to Russian values as well as to its state interests. Each of these positions,
in turn, draws on an identifiable set of domestic constituencies: Liberal Westernisers on the promarket political parties, Pragmatic Nationalists on the presidential administration and defence and security ministries, and Fundamentalist Nationalists on the Orthodox Church and Communists
An electrothermal vaporization unit with axially focusing convection upstream and influence of modifiers. Part I: Experimental
A novel, further improved construction of an electrothermal vaporization (ETV) unit is described, and new measurements are presented. Its main feature is an upstream within a vertical tube creating an axially focusing convection zone, where the condensation occurs in a laminar flow predominantly apart from the colder walls. The upstream is shielded against incandescent emission of the graphite furnace (GF) and surrounded with different cooling gas flows, that have additional focusing effect. The transported ETV generated aerosol is electrostatically precipitated onto a secondary platform that is subsequently analyzed for the transported analytes. Transport efficiencies (TEs) for Cu, Fe, Mn, Ni, and Pb are studied using a continuum source coherent forward scattering multi-element spectrometer coupled to the ETV. Increasing TE is observed with the ageing of the GF. The effect is presumably ascribed to the growing content of carbon particulates released during the vaporization. A positive impact of K and Pd modifiers in microgram amounts foremost on the TEs of more volatile species is observed and discussed. © 2006 Elsevier B.V. All rights reserved
Russia and the Arab Spring: supporting the counter-revolution
Russiaâs response to the Arab Spring ranged from apprehension to deep anxiety and diverged significantly from the US and the EU responses. While initially
welcoming the popular demands for political reform in North Africa, the Russian reaction rapidly became more critical as a result of Western military intervention into Libya and the threat of the spread of Islamist extremism. It was these twin fears which prompted the Russian leadership to adopt an uncompromizing stance towards Syria. While geopolitical factors certainly played a role in driving Russian strategy, domestic political factors were also more significant. As the Russian leadership felt internally threatened by the growing opposition within the country, conflict in the
Middle East highlighted the perceived flaws of the imposition of Western liberal democracy and the virtues of Russiaâs own model of state-managed political order.
There was, as such, a significant ideational and ideological dimension to the Russian response to the Arab Spring
Russiaâs Eurasian past, present and future: rival international societies and Moscowâs place in the post-cold war world
The failure of post-Soviet Russia to integrate into the West became
evident with the 2014 Ukraine crisis, leading Moscow to accelerate
its declared âpivot to the Eastâ. However, the increased dependence
on China carries its own risks, such as the danger of becoming
Beijingâs junior partner. For an erstwhile superpower that
continues to declare and prize its autonomy in international
affairs, this is a particularly unappealing prospect. Thus, it remains
to be seen whether a genuinely balanced partnership can exist
between both countries. This article uses insights from Adam
Watsonâs pendulum theory to explore Russiaâs post-2014 Eurasian
predicament. We argue that the rapid rightward swing of the
pendulum in the Euro-Atlantic order following the end of the Cold
War has proven indigestible for Moscow. The article then moves
to discuss the Sino-Russian relationship in the context of the
emerging Eurasian space. It concludes that the growing
disillusionment of Russian leaders with the West since the 2000s,
along with the normative convergence between Moscow and
Beijing, has led to a closer partnership between the two. Yet the
partnership is also riddled with a number of insecurities on
Moscowâs side that could undermine the long-term prospects for
cooperation between Russia and China
Platform-to-platform sample transfer, distribution, dilution, and dosing via electrothermal vaporization and electrostatic deposition
A novel system for solid sample pretreatment, handling and dosing for analytical atomic spectrometry is described. A primary solid or liquid sample is vaporized in a graphite furnace and then condensed in a specially designed condensation zone. On the further transport path, the analyte aerosol can be diluted and distributed in pre-set ratios in the laboratory made flow control system. Applying a corona discharge, aerosol particulates are then quantitatively re-collected by means of intra-furnace electrostatic precipitation on the platform of another graphite furnace or by external precipitation on one or a set of platforms. This makes possible to produce a set of secondary platforms with equal analyte compositions from one individual primary sample. Such multitudes allow sequential multi-element determinations with single-element instrumentation or comparative measurements with different techniques. Furthermore, the described procedure allows external thermal sample pretreatment with preceding pyrolysis and additional vaporization, condensation, and re-precipitation that significantly reduces or removes the sample matrix. Owing to different losses, transport efficiencies of electrothermal vaporization (ETV) instrumentation depend on analyte element, matrix, vaporization temperature, ramp rate, and tube history. In order to reduce the losses and therewith such dependencies of the losses, new laboratory constructed ETV unit with analyte condensation in an axially focusing upstream convection zone has been constructed. Analytical performance of the new setup is compared with the performance of a commercial end-on flow-through ETV unit when analyzing both liquid dosed samples and certified solid reference materials. The new system shows much higher transport efficiencies that are, in addition, more uniform for elements of different volatility. The effects of chemical sample modifiers and elements supporting analyte condensation are studied. Most of the analytical measurements were carried out with a continuum source coherent forward scattering multi-element spectrometer. Comparative measurements were also carried out independently in the co-authors' laboratories with atomic absorption and inductively coupled plasma mass spectrometry techniques. © 2004 Elsevier B.V. All rights reserved
Normative resistance to responsibility to protect in times of emerging multipolarity: the cases of Brazil and Russia
This article assesses the normative resistance to Responsibility to Protect adopted by Brazil and Russia against the backdrop of their international identities and self-assigned roles in a changing global order. Drawing upon the framework of Bloomsfield's norm dynamics role spectrum, it argues that while the ambiguous Russian role regarding this principle represents an example of 'norm antipreneurship', particularities of Brazil's resistance are better grasped by a new category left unaccounted for by this model, which this study portrays as 'contesting entrepreneur'.- (undefined
An electrothermal vaporization unit with axially focusing convection upstream. Part II: Modeling of the condensation process
A model is presented that describes quantitatively the condensation of analytes in pico- and nanogram masses sampled with electrothermal vaporization (ETV). It presumes that the analyte vapor condensation of such low amounts occurs mainly heterogeneously, predominantly on growing carbon particulates originating from the graphite furnace before the analyte vapor achieves saturation via cooling. The model regards the coagulation of carbon particles and the diffusion of analyte atoms. The criterion whether or not an analyte atom sticks to a colliding particle is chosen as a function depending on its temperature and on the common GFAAS pretreatment temperatures. Heterogeneous condensation of six analytes with different volatilities, Ag, Cu, Fe, Ni, Mn, and Pb, is calculated for the ETV unit with an axially focusing convection upstream described in Part I. Modifier effects are taken into account. The results are compared to measured data. © 2006 Elsevier B.V. All rights reserved
An electrothermal vaporization unit with axially focusing convection upstream. Part II: Modeling of the condensation process
A model is presented that describes quantitatively the condensation of analytes in pico- and nanogram masses sampled with electrothermal vaporization (ETV). It presumes that the analyte vapor condensation of such low amounts occurs mainly heterogeneously, predominantly on growing carbon particulates originating from the graphite furnace before the analyte vapor achieves saturation via cooling. The model regards the coagulation of carbon particles and the diffusion of analyte atoms. The criterion whether or not an analyte atom sticks to a colliding particle is chosen as a function depending on its temperature and on the common GFAAS pretreatment temperatures. Heterogeneous condensation of six analytes with different volatilities, Ag, Cu, Fe, Ni, Mn, and Pb, is calculated for the ETV unit with an axially focusing convection upstream described in Part I. Modifier effects are taken into account. The results are compared to measured data. © 2006 Elsevier B.V. All rights reserved
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