"Download for Free" - When Do Providers of Digital Goods Offer Free Samples?

In a monopoly setting where consumers cannot observe the quality of the product we show that free samples which are of a lower quality than the marketed digital goods are used together with high prices as signals for a superior quality if the number of informed consumers is small and if the difference between the high and the low quality is not too small. Social welfare is higher, if the monopolist uses also free samples as signals, compared to a situation where he is restricted to pure price signalling. Both, the monopolist and consumers benefit from the additional signal

Stable superconducting magnet

Operation of a superconducting magnet is considered. A method is described for; (1) obtaining a relatively high current in a superconducting magnet positioned in a bath of a gas refrigerant; (2) operating a superconducting magnet at a relatively high current level without training; and (3) operating a superconducting magnet containing a plurality of turns of a niobium zirconium wire at a relatively high current level without training

Membrane formation by immersion precipitation : the role of a polymeric additive

In this thesis the immersion precipitation process is studied for systems in which two polymers are present.\ud In its basic form, immersion precipitation is carried out by immersing a thin film of a concentrated polymer solution into a bath of nonsolvent. By exchange of solvent from the polymer solution, and nonsolvent from the coagulation bath, the polymer solution becomes instable. Liquid-liquid phase separation results in a polymer lean phase and a polymer rich phase. The polymer lean phase forms pores inside a matrix created by the polymer rich phase, which forms the membrane.\ud The objective of this thesis is to investigate the effects of the addition of a second polymer into the polymer solution. The use of a second polymer (polymeric additive) that is miscible with the nonsolvent can result in more open porous (co-continuous) structures and a better defined porosity

"Download for Free" - When Do Providers of Digital Goods Offer Free Samples?

In a monopoly setting where consumers cannot observe the quality of the product we show that free samples which are of a lower quality than the marketed digital goods are used together with high prices as signals for a superior quality if the number of informed consumers is small and if the difference between the high and the low quality is not too small. Social welfare is higher, if the monopolist uses also free samples as signals, compared to a situation where he is restricted to pure price signalling. Both, the monopolist and consumers benefit from the additional signal.Digital Goods; Free Samples; Multi-dimensional Signalling

"Download for Free": When do providers of digital goods offer free samples?

In a monopoly setting where consumers cannot observe the quality of the product we show that free samples which are of a lower quality than the marketed digital goods are used together with high prices as signals for a superior quality if the number of informed consumers is small and if the difference between the high and the low quality is not too small. Social welfare is higher, if the monopolist uses also free samples as signals, compared to a situation where he is restricted to pure price signalling. Both, the monopolist and consumers benefit from the additional signal. --

Strategic Choice of Domestic Environmental Policy Instrument and International Emissions Trading Scheme in an Open Economy with Imperfect Competition

This paper presents a model of imperfect international competition. Within this framework, the optimal choice of national environmental policy instrument and international emissions trading scheme is discussed. The choice of national instrument is restricted to absolute and relative standards, which form the basis for permit and credit trading respectively. It is shown that relatives standards and credit trading lead to higher output than emission ceilings and permit trading. I find that governments want to increase production beyond the level reached with emission ceilings and therefore prefer relative standards. Furthermore, international emissions trading is only optimal when the country imports emission quotas, and in several cases, governments will choose not to allow international emissions trading.environmental policy, emissions trading, credit trading, international trade, imperfect competition, strategic behavior, Environmental Economics and Policy, F12, L51, Q25, Q28,

Identification of left ventricular model parameters

Simulations with a model of left ventricular pressure generation consisting of time-varying elastance, resistance, series-elastance, and deactivation were fitted to pressure curves measured in the isolated rabbit ventricle. For constant ejection flows, a fit with a RMS error of 2.78 mmHg was obtained provided that deactivation was actually incorporated in the model. Deactivation was assumed to depend linearly on end ejection pressure. Resistance was found to be independent of volum

Left ventricular active stiffness: dependency on time and inotropic state

Left ventricular systolic stiffness was measured by rapidly changing ventricular volume (within 7 ms) of isovolumically contracting isolated rabbit hearts. Instantaneous pressure-volume relations were found to be linear with slopes that depended upon the moment during contraction at which the volume change was induced. These slopes were proportional to the total pressure developed in the ventricle just prior to the volume change. The same was found when the time course of pressure was influenced by changing the Ca++ content of the perfusate. An influence, however, also could be detected when end-diastolic volume was changed. At the same pre-release pressure a greater volume caused a decrease of active stiffness. The results indicate the possiblity of an active component in ventricular systolic stiffness

Strategic Choice of International Emissions Trading Scheme in an Open Economy with Perfect Competition

Emissions trading can be organized in several ways. In particular, private emissions trading can be organized as permit trading, or as credit trading. The schemes have a different impact on output with credit trading leading to a higher output level than permit trading. This paper analyzes what the optimal choice of emissions trading scheme is in a model with international trade and perfect competition in the product and emission quota market. Furthermore, I discuss whether it is optimal for the country to allow its firms to trade emissions internationally. The paper shows that countries want to use these schemes in different circumstances, depending on whether they import or export the good. Furthermore, it is shown that in several cases, countries maximize their welfare by not allowing international emissions trading.environmental policy, emissions trading, credit trading, international trade, perfect competition, strategic behavior, Environmental Economics and Policy, F10, L51, Q25, Q28,