The Political Economy of Corporate Governance Change in Bulgaria: Washington Consensus, Primitive Accumulation of Capital, and Catching-Up in the 1990

This study examines three key determinants of corporate governance change in Bulgaria: the Washington Consensus policy, primitive accumulation of capital forces, and 'catching-up' factors. The study reveals that in the early transition (1989-96) primitive capital accumulation prevailed over the Washington Consensus impact on corporate governance transformation while since 1997 Washington Consensus has been in the process of becoming the decisive factor for institutional change. The emerging corporate governance system has been neither Anglo-American (market based) nor bank-based, but rather a 'crony' relationship-based one. The striking features of this system are as follows: (i) a dual enterprise sector, (ii) ownership heterogeneity; (iii) fragile capital markets; (iv) pervasive banks lending behavior; (v) globalization factors discretion. The challenge to policy-makers in Bulgaria is how to design institutions for 'catching-up' that would curb both managerial and globalization factors discretion.

Banks-Firms Nexus under the Currency Board: Empirical Evidence from Bulgaria

This study analyses bank lending in the larger context of bank-firm relations within the Bulgarian specificity of currency board. It focuses on the ‘intersection’ of credit supply and demand on the side of banks and firms simultaneously. We suggest both traditional and new hypotheses corresponding to the specific conditions of the Bulgarian ownership change, transitional corruption and other institutional and political factors. The model is based on a survey on Bulgarian banks and a unique database on firms. The study found that the dynamics and structure of credit is affected mainly by the features of the institutional environment, whereas the ‘resource’ and traditional factors became secondary. During the period 1998 – 2001, there is separation of the banking sector activity from the activity of the real sector in Bulgaria. In the new conditions of currency board, the dual sector of enterprises and the specific institutional environment continue their existence. Despite its disciplining effect the currency board by itself is not sufficiently effective to overcome the remaining ‘institutional obstacles, associated mainly with the inefficiency of the judicial system, corruption, state capture, uncertain property rights, etc.corporate governance, bank lending, currency board, corruption, transition economy

On the optimality of individual entangling-probe attacks against BB84 quantum key distribution

It is shown that an existing method to study ideal individual attacks on the BB84 QKD protocol using error discard can be adapted to reconciliation with error correction, and that an optimal attack can be explicitly found. Moreover, this attack fills Luetkenhaus bound, independently of whether error positions are leaked to Eve, proving that it is tight. In addition, we clarify why the existence of such optimal attacks is not in contradiction with the established ``old-style'' theory of BB84 individual attacks, as incorrectly suggested recently in a news feature.Comment: 12 pages, 3 figure

Improving EE of an industrial site by utilizing WH and TES

This master thesis is based on a real project for an industrial client of SENER that works in the field of metallurgy. The main objective is to provide initial recommendations and feasibility study on how to best utilize the waste heat that is available in the exhaust gasses from the production processes of the client. This would be done by improving the energy efficiency of the site by means of Waste Heat Recovery (WHR). The recovered heat would be used to drive a steam turbine that produces electricity, as no thermal uses of this heat are available in the installation. Furthermore, this thesis also aims to quantify the positive environmental impact of the WHR system, and how many tons of CO2 emissions would be avoided. Additionally, due to large fluctuations in the mass flow rate of the exhaust gasses, a thermal energy storage might be introduced in order to balance the supply. Two different energy storage systems will be analyzed: steam accumulation and molten salts. The scientific fundamentals of this thesis are based on the science of thermodynamics, or more precisely, mass and energy balances. They would have to be done on each individual component, as well as a global balance. This is done mainly with the help of the “Thermoflex” software, which is used to model the system. However, for some equipment, in-house tools have been developed, in order to understand their behavior and temporal evolution. In order to obtain the properties of the fluids, the open source library CoolProp has been used. The obtained results from the analysis suggest that there is a potential for the implementation of a WHR system. Such a system could yield more than 160000 MWh of yearly production of electricity. Depending on the electricity prices, this amount of electricity produced could be valued at more than 10 million euros. Furthermore, by using waste heat as source of energy, essentially a carbon-free electricity would be produced, which would save approximately 8600 tCO2 emissions. To conclude, it has been decided that such a project is worthwhile pursuing into more detail. This would imply contacting manufacturers of components, basic and detailed engineering, as well as giving a firm offer to the client. However, it should be noted that other factors have to be taken into consideration, such as the treatment of exhaust gasses and to which degree they can be used. This could be a limiting factor, for maximizing the energy efficiency of the entire sit

Demystifying the Information Reconciliation Protocol Cascade

Cascade is an information reconciliation protocol proposed in the context of secret key agreement in quantum cryptography. This protocol allows removing discrepancies in two partially correlated sequences that belong to distant parties, connected through a public noiseless channel. It is highly interactive, thus requiring a large number of channel communications between the parties to proceed and, although its efficiency is not optimal, it has become the de-facto standard for practical implementations of information reconciliation in quantum key distribution. The aim of this work is to analyze the performance of Cascade, to discuss its strengths, weaknesses and optimization possibilities, comparing with some of the modified versions that have been proposed in the literature. When looking at all design trade-offs, a new view emerges that allows to put forward a number of guidelines and propose near optimal parameters for the practical implementation of Cascade improving performance significantly in comparison with all previous proposals.Comment: 30 pages, 13 figures, 3 table

The persistence of profits in banking: an international comparison

This article examines the dynamics of bank profitability in the USA, Germany, Great Britain, France, Italy and Switzerland over the period 1993-2014. We find long-run bank profit persistence in all six countries in the period before the financial crisis in 2008. Banks with large capital ratios are persistently more profitable, and there is little evidence of a link between bank size and the persistence of bank profits. Commercial (saving) banks are persistently more (less) profitable in four of the six countries. The effects of the financial crisis in 2008 differed dramatically across countries as well as across ownership types. While US banks experienced dramatic declines in the immediate aftermath of the crisis, they recovered much faster than their European counterparts and essentially retain their long run profit potential by the year 2014

Accuracy and reliability of lower dental arch reconstructions

Introduction: In the literature, there is information regarding the accuracy of models generated by conventional impression materials and intraoral scanners, but data on the accuracy of 3D models generated from cone-beam computed tomography (CBCT) is still lacking.Aim: The aim of this article is to investigate and compare the accuracy of tooth reconstructions made on 3D models generated from CBCT and intraoral scanning, as well as on plaster models from conventional impression materials, to the results of intraoral measurements using a digital caliper.Materials and Methods: The study included a total of 38 individuals (16 males and 22 females). After the initial examination, we scheduled appointments for the approved participants to undergo clinical procedures and imaging studies in the following sequence: 1. placement of composite markers; 2. physical measurements; 3. intraoral scanning; 4. CBCT; 5. capturing a conventional impression; 6. removal of composite markers. Following are the laboratory and measurement stages for the study: 7. casting gypsum models; 8. measurements on gypsum models; 9. converting the DICOM files from CBCT scans to STL files; 10. conducting measurements on digital models from CBCT and intraoral scanning.Results: Results from the reliability assessment of the researcher’s measurements for the studied modalities indicate a correlation coefficient ranging from moderate to excellent with very high statistical significance. Concerning accuracy, differences are observed between individual modalities. Conclusion: In summary, conventional methods and materials still outperform intraoral scanners in terms of the accuracy of the obtained reconstructions. 3D models generated from CBCT scans are generally the least satisfactory among the tested modalities, with deviations typically within clinically acceptable values

Effect on pain and facial edema of platelet-rich plasma in removed radicular cysts

The effect on pain scores of platelet-rich plasma (PRP) applied alone or in combination either with collagen or with autologous bone was followed up on the first, third and seventh day in 42 patients, 26 males and 16 females, with removed radicular cysts as well as in 15 patients without this treatment. The degree of postoperative facial edema on the first day was examined, too. An increased frequency of slightly expressed pain (with a summary score of 1 and 2 according to the visual analogue scale) was established in the radicular cysts during the initial seven days by means of PRP alone as well as by means of both PRP and collagen, and both PRP and autologous bone, respectively. The mean pain scores between the first and seventh day after treatment were statistically significantly lower with the use of PRP alone (t=9.665; р<0.00001), PRP with collagen (t=10.175; р<0.00001) and PRP with autologous bone (t=12.516; р<0,00001). There was no statistical significance in terms of the mean differences between the effect on the degree of postoperative edema of these three treatment methods of radicular cysts one towards another and towards the control patients. The application of PRP alone or in combination with collagen or autologous bone exerted a favorable influence on pain and facial edema in the patients with removed radicular cysts