Heterojunction Band Offset Limitations on Open-Circuit Voltage in p-ZnTe/n-ZnSe Solar Cells

Limitations on the open-circuit voltage of p-ZnTe/n-ZnSe heterojunction solar cells are studied via current-voltage (I-V) measurements under solar concentration and at variable temperature. The open-circuit voltage reaches a maximum value of 1.95 V at 77 K and 199 suns. The open-circuit voltage shows good agreement with the calculated built-in potential of 2.00 V at 77 K. These results suggest that the open-circuit voltage is limited by heterojunction band offsets associated with the type-II heterojunction band lineup, rather than the bandgap energy of the ZnTe absorber material.

Viral dynamics in vivo: limitations on estimates of intracellular delay and virus decay.

Anti-viral drug treatment of human immunodeficiency virus type I (HIV-1) and hepatitis B virus (HBV) infections causes rapid reduction in plasma virus load. Viral decline occurs in several phases and provides information on important kinetic constants of virus replication in vivo and pharmacodynamical properties. We develop a mathematical model that takes into account the intracellular phase of the viral life-cycle, defined as the time between infection of a cell and production of new virus particles. We derive analytic solutions for the dynamics following treatment with reverse transcriptase inhibitors, protease inhibitors, or a combination of both. For HIV-1, our results show that the phase of rapid decay in plasma virus (days 2-7) allows precise estimates for the turnover rate of productively infected cells. The initial quasi-stationary phase (days 0-1) and the transition phase (days 1-2) are explained by the combined effects of pharmacological and intracellular delays, the clearance of free virus particles, and the decay of infected cells. Reliable estimates of the first three quantities are not possible from data on virus load only; such estimates require additional measurements. In contrast with HIV-1, for HBV our model predicts that frequent early sampling of plasma virus will lead to reliable estimates of the free virus half-life and the pharmacological properties of the administered drug. On the other hand, for HBV the half-life of infected cells cannot be estimated from plasma virus decay.

GE models and algorithms for condensed phase equilibrium data regression in ternary systems: limitations and proposals

Phase equilibrium data regression is an unavoidable task necessary to obtain the appropriate values for any model to be used in separation equipment design for chemical process simulation and optimization. The accuracy of this process depends on different factors such as the experimental data quality, the selected model and the calculation algorithm. The present paper summarizes the results and conclusions achieved in our research on the capabilities and limitations of the existing GE models and about strategies that can be included in the correlation algorithms to improve the convergence and avoid inconsistencies. The NRTL model has been selected as a representative local composition model. New capabilities of this model, but also several relevant limitations, have been identified and some examples of the application of a modified NRTL equation have been discussed. Furthermore, a regression algorithm has been developed that allows for the advisable simultaneous regression of all the condensed phase equilibrium regions that are present in ternary systems at constant T and P. It includes specific strategies designed to avoid some of the pitfalls frequently found in commercial regression tools for phase equilibrium calculations. Most of the proposed strategies are based on the geometrical interpretation of the lowest common tangent plane equilibrium criterion, which allows an unambiguous comprehension of the behavior of the mixtures. The paper aims to show all the work as a whole in order to reveal the necessary efforts that must be devoted to overcome the difficulties that still exist in the phase equilibrium data regression problem.

Supply and Demand Side Limitations Affecting the Structure of Agriculture and the Rural Economy. Factor Markets Working Paper No. 21, February 2012

The paper criticises the neo-classical assumptions of perfect factor markets and of complete information, which constitute central elements in labour market theory. Based on literature review and on economic reports from transition economies, as well as developing countries and more advanced economies, this deliverable focuses on the structural impediments and imperfections which often characterise rural labour markets and which may prevent an efficient allocation of labour. According to empirical studies, transactions costs and rigidities hinder the well-functioning of labour markets and constrain labour adjustments. The paper attempts to classify the various limitations of rural labour markets from both supply and demand side, although the distinction is not always clear-cut as some problems occur on both sides. The identification of these issues is extremely important as it allows us to highlight the inefficiencies and the failures in labour markets and to understand their impact on labour allocation. In this context, market intervention is desirable and the paper provides particular support for rural development policies such as investments in human capital. Lastly, labour institutions can play a key role in promoting the well functioning of labour markets, thus it is fundamental that they are well in place.

The limitations of policy coordination in the euro area under the European Semester. Bruegel Policy Contribution 2015/19, November 2015

The European Semester is a yearly process of the European Union to improve economic policy coordination and ensure the implementation of the EU’s economic rules. Each Semester concludes with recommendations for the euro area as a whole and for each EU member state. We show that implementation of recommendations was poor at the beginning of the Semester in 2011, and has deteriorated since. The European Semester is not particularly effective at enforcing even the EU’s fiscal and macroeconomic imbalance rules. We find that euro-area recommendations with tangible economic goals are not well reflected in the recommendations issued to member states. Finally, we review various proposals to improve the efficiency of the European Semester and conclude that while certain steps could be helpful, policy coordination will likely continue to have major limitations.

Taiwanese Lobbying in the European Union: ‘Workable Diplomacy’ and its Limitations. EU Diplomacy Paper 8/2015

The policy of the European Union (EU) towards Taiwan has mostly been analysed either as a by-product of EU-China relations or with reference to the general lack of a European geopolitical approach towards East Asia. By adopting a lobbying approach which focusses on Taiwan’s different ‘channels of influence’ within the complex European foreign policy system in Brussels, this study provides new insights into the functioning of EU-Taiwan relations. It also sheds new light on the implications of the radical change in Taiwanese diplomacy after 2008, when Chen Shui-bian’s assertive and identity-based diplomacy was replaced with the Kuomintang’s new dogma of ‘workable diplomacy’. Based on semi-guided interviews with Taiwanese and European actors, this paper examines why Taiwanese lobbying in Brussels, albeit very active and professional, is not salient enough to meet the challenges arising from the overwhelming Chinese competition and from the increasing proliferation of regional trade agreements – with active EU participation – in the Asia-Pacific region. It argues that the pragmatic ‘workable diplomacy’ approach, while smoothing out working-level relations between Taiwan and the EU, fails to attract a sufficient degree of political and public attention in Europe to the Taiwan question and thus fosters the neglect of Taiwan by European foreign policy-makers. The main challenge faced by Taiwanese diplomacy, however, is not simply one of convincing through technical arguments, but one of agenda setting, that is, of redefining European priorities in Taiwan’s favour.

The EU approach to Gender: Limitations and Alternatives. European Policy Brief No. 40, December 2015

For several decades, the European Union has been at the forefront of significant progress in the struggle towards equality between women and men, among others in the fight against sex-based discriminations. The contemporary EU approach to gender has however become much more interested in representations and social norms. This paper analyses this stance and highlights its deficiencies – more specifically, it looks at the flaws entailed in an excessive focus on “gender stereotypes”. Finally, it briefly sketches out the principles of an alternative.

Limitations of microbial hydrocarbon degradation at the Amon Mud Volcano (Nile Deep Sea Fan)

The Amon mud volcano (MV), located at 1250 m water depth on the Nile Deep Sea Fan, is known for its active emission of methane and non-methane hydrocarbons into the hydrosphere. Previous investigations showed a low efficiency of hydrocarbon-degrading anaerobic microbial communities inhabiting the Amon MV center in the presence of sulphate and hydrocarbons in the seeping subsurface fluids. By comparing spatial and temporal patterns of in situ biogeochemical fluxes, temperature gradients, pore water composition and microbial activities over three years, we investigated why the activity of anaerobic hydrocarbon degraders can be low despite high energy supplies. We found that the central dome of the Amon MV, as well as a lateral mud flow at its base, showed signs of recent exposure of hot subsurface muds lacking active hydrocarbon degrading communities. In these highly disturbed areas, anaerobic degradation of methane was less than 2% of the methane flux. Rather high oxygen consumption rates compared to low sulphide production suggest a faster development of more rapidly growing aerobic hydrocarbon degraders in highly disturbed areas. In contrast, the more stabilized muds surrounding the central gas and fluid conduits hosted active anaerobic hydrocarbon-degrading microbial communities. Furthermore, within three years, cell numbers and hydrocarbon degrading activity increased at the gas-seeping sites. The low microbial activity in the hydrocarbon-vented areas of Amon mud volcano is thus a consequence of kinetic limitations by heat and mud expulsion, whereas most of the outer mud volcano area is limited by hydrocarbon transport.

Quand le tabac s’affiche au Parlement. Débats sur les limitations en matière de publicité de la cigarette dans les cantons romands

Cette contribution porte sur les politiques d’interdiction de la publicité pour les cigarettes, l’un des axes-clé de la prévention structurelle du tabagisme. Nous nous intéressons à la rapide et récente dissémination de ces politiques dans les cantons suisses, qui contraste avec l’immobilisme fédéral. Nous attirons alors l’attention sur le rôle moteur du niveau d’action cantonal, au sein d’un domaine de santé publique qui avait pourtant connu, cette dernière décennie, ses plus formidables avancées dans le sillage de mouvements d’essence supranationaux. L’analyse des débats parlementaires romands nous permet finalement d’élaborer une typologie des argumentaires en présence, et de mettre en évidence les axes les plus à mêmes de provoquer une scission gauche/droite.

Effects of lender decisions on farm financial planning : some solutions to problems arising from credit limitations set by commercial lenders /

Cover title.

Water-quality assessment of the Lower Susquehanna River Basin, Pennsylvania and Maryland : sources, characteristics, anaylsis, and limitations of nutrient and suspended-seditment data, 1975-90 /

"National Water-Quality Assessment Program"

More information is needed on the advantages and limitations of animal experimentation before deciding whether legislation is needed for research funds.

Mode of access: Internet.

Driver visual limitations diagnosis and treatment. Final report.

National Highway Traffic Safety Administration, Washington, D.C.