As part of the production of certain solid-dosage pharmaceuticals, granulated ingredients are dried in a batch fluidized bed dryer. Currently, the determination of the completion of the drying process is accomplished through measurements of product or outlet air temperatures. No quantitative measurement of hydrodynamic behaviour is employed. Changes in bed hydrodynamics caused by variations in fluidization velocity may lead to increased particle attrition. In addition, excessive desiccation of the granules caused by inaccurate determination of the drying endpoint may lead to an increase in the thermal and mechanical stresses within the granules. The activity of future high-potency or peptide based drug products may be influenced by these effects. Therefore, the quantification of hydrodynamic changes may be a key factor in the tighter control of both fluidization velocity and product moisture, which are critical for maintaining product quality. <p>High-frequency measurements of pressure fluctuations in a batch fluidized bed dryer containing pharmaceutical granulate have been used to provide a global, non-intrusive indication of the hydrodynamic changes occurring throughout the drying process. A chaotic attractor comparison statistical test known as the S-statistic, has been applied to quantify these changes in drying and a related unit operation, fluidized bed granulation. The S-statistic showed a sensitivity to moisture which is not seen with frequency and amplitude analysis. In addition, the S-statistic has been shown to be useful in identifying an undesirable bed state associated with the onset of entrainment in a bed instrumented for the collection of both pressure fluctuation and entrainment data. Thus, the use of the S-statistic analysis of pressure fluctuations may be utilized as a low-cost method for determining product moisture or changes hydrodynamic state during fluidized bed drying. <p>Electrical capacitance tomography (ECT) has also been applied in this study to image the flow structure within a batch fluidized bed used for the drying of pharmaceutical granulate. This represents the first time that ECT has been applied to a bed of wet granulate material. This was accomplished through the use of a novel dynamic correction technique which accounts for the significant reduction in electrical permittivity occurring as moisture is lost during the drying process. The correction has been independently verified using x-ray tomography. <p>Investigation of the ECT images taken in the drying bed indicates centralized bubbling behaviour for approximately the first 5 minutes of drying. This behaviour is a result of the high liquid loading of the particles at high moisture. Between moisture contents of 18-wt% and 10-wt%, the tomograms show an annular pattern of bubbling behaviour with a gradual decrease in the cross-sectional area involved in bubbling behaviour. The dynamic analysis of this voidage data with the S-statistic showed that a statistically significant change occurs during this period near the walls of the vessel, while the centre exhibits less variation in dynamic behaviour. The changes identified by the S-statistic analysis of voidage fluctuations near the wall were similar to those seen in the pressure fluctuation measurements. This indicates that the source of the changes identified by both these measurement techniques is a result of the reduction in the fraction of the bed cross-section involved in bubbling behaviour. At bed moisture contents below 5-wt%, rapid divergence was seen in the S-statistic applied to both ECT and pressure fluctuation measurements. This indicates that a rapid change in dynamics occurs near the end of the drying process. This is possibly caused by the entrainment of fines at this time, or the build-up of electrostatic charge. <p>The use of the complimentary pressure fluctuation and ECT measurement techniques have identified changes occurring as a result of the reduction of moisture during the drying process. Both the localized changes in the voidage fluctuations provided by the ECT imaging and the global changes shown by the pressure fluctuation measurements indicate significant changes in the dynamic behaviour caused by the reduction of moisture during the drying process. These measurement techniques could be utilized to provide an on-line indication of changes in hydrodynamic regime. This information may be invaluable for the future optimization of the batch drying process and accurate determination of the drying endpoint.

The understanding of central banking has evolved several times in the history. Different economic and political conditions shaped the structure of monetary policy and the stance of central banks. The Central Bank of Republic of Turkey (CBRT) also has experienced several reactionary policy shifts throughout its history. Nowadays, majority of central banks have started to follow financial stability programs after the Global Financial Crisis of 2008-09. The CBRT was one of the followers of financial stability targeting and has started to implement a new monetary policy structure after the Global Financial Crisis. The new monetary policy of the CBRT in which the financial stability was put nearby price stability came up with new challenges. Therefore in this thesis, we elaborate on the challenges of the CBRT and propose policy suggestions for the possible deficiencies of the new structure of the CBRT. We argue that the experiences of the CBRT in the inflation targeting period and the macroeconomic conditions of both during and post crisis period have shaped the new structure of the monetary policy, and the new policy mix of the CBRT may not be successful in all its targets at the same time because of the existence of &ldquo / macroeconomic quadrilemma&rdquo / tradeoffs as well as because of the ineffectiveness of the tool portfolio of the CBRT.

The central concern of this thesis is the study of non-equilibrium behaviour in magnetic materials and its interpretation within the framework of the Preisach model of hysteresis. Comprehensive experimental characterizations of the field and temperature and time dependence of a suite of standard magnetic response functions have been performed on a variety of magnetic materials, including a naturally occurring mineral of nanodimensional titanomagnetite particles embedded in volcanic glass, a compressed powder of nanodimensional magnetite particles immobilized in an organic binder, a thin film of nanodimensional Fe particles embedded in alumina, and a series of sintered, bond-disordered CaxSr1-xRuO3 ferromagnets. The measurements were compared with numerical simulations based on a model Preisach ensemble of thermally activated two-level subsystems, characterized individually by a double well free energy profile in a two-dimensional configuration space, an elementary moment reversal, a dissipation field and a bias field, and characterized collectively by a distribution of these characteristic fields. Our efforts were concentrated on two principal spheres of investigation. (1) By performing detailed numerical simulations of the relaxation response of model Preisach collections of two-level subsystems under the same field and temperature protocols used to probe experimentally the relaxation dynamics of spin glasses, we have been able to show that aging, memory and rejuvenation effects are ubiquitous features of all materials which possess a broad distribution of free energy barriers which block the approach to thermal equilibrium. (2) We propose a general strategy for isolating and quantifying the two principal mechanisms, thermal fluctuations and barrier growth, which are jointly responsible for shaping the measured temperature dependence of the magnetic properties of all magnetic materials which exhibit a history dependent response to an external field excitation, and is based on the analysis of viscosity isotherms and, in particular, on a plot of T ln(tr/0) versus Ha , where tr is the time at which a viscosity isotherm measured in a field Ha at temperature T reverses sign. When thermal activation dominates barrier growth, this plot will yield a universal curve while, in the opposite limit the plot fractures into a family of isothermal curves. The strategy is applied to the analysis of each magnetic material listed above. / February 2009

As part of the production of certain solid-dosage pharmaceuticals, granulated ingredients are dried in a batch fluidized bed dryer. Currently, the determination of the completion of the drying process is accomplished through measurements of product or outlet air temperatures. No quantitative measurement of hydrodynamic behaviour is employed. Changes in bed hydrodynamics caused by variations in fluidization velocity may lead to increased particle attrition. In addition, excessive desiccation of the granules caused by inaccurate determination of the drying endpoint may lead to an increase in the thermal and mechanical stresses within the granules. The activity of future high-potency or peptide based drug products may be influenced by these effects. Therefore, the quantification of hydrodynamic changes may be a key factor in the tighter control of both fluidization velocity and product moisture, which are critical for maintaining product quality. <p>High-frequency measurements of pressure fluctuations in a batch fluidized bed dryer containing pharmaceutical granulate have been used to provide a global, non-intrusive indication of the hydrodynamic changes occurring throughout the drying process. A chaotic attractor comparison statistical test known as the S-statistic, has been applied to quantify these changes in drying and a related unit operation, fluidized bed granulation. The S-statistic showed a sensitivity to moisture which is not seen with frequency and amplitude analysis. In addition, the S-statistic has been shown to be useful in identifying an undesirable bed state associated with the onset of entrainment in a bed instrumented for the collection of both pressure fluctuation and entrainment data. Thus, the use of the S-statistic analysis of pressure fluctuations may be utilized as a low-cost method for determining product moisture or changes hydrodynamic state during fluidized bed drying. <p>Electrical capacitance tomography (ECT) has also been applied in this study to image the flow structure within a batch fluidized bed used for the drying of pharmaceutical granulate. This represents the first time that ECT has been applied to a bed of wet granulate material. This was accomplished through the use of a novel dynamic correction technique which accounts for the significant reduction in electrical permittivity occurring as moisture is lost during the drying process. The correction has been independently verified using x-ray tomography. <p>Investigation of the ECT images taken in the drying bed indicates centralized bubbling behaviour for approximately the first 5 minutes of drying. This behaviour is a result of the high liquid loading of the particles at high moisture. Between moisture contents of 18-wt% and 10-wt%, the tomograms show an annular pattern of bubbling behaviour with a gradual decrease in the cross-sectional area involved in bubbling behaviour. The dynamic analysis of this voidage data with the S-statistic showed that a statistically significant change occurs during this period near the walls of the vessel, while the centre exhibits less variation in dynamic behaviour. The changes identified by the S-statistic analysis of voidage fluctuations near the wall were similar to those seen in the pressure fluctuation measurements. This indicates that the source of the changes identified by both these measurement techniques is a result of the reduction in the fraction of the bed cross-section involved in bubbling behaviour. At bed moisture contents below 5-wt%, rapid divergence was seen in the S-statistic applied to both ECT and pressure fluctuation measurements. This indicates that a rapid change in dynamics occurs near the end of the drying process. This is possibly caused by the entrainment of fines at this time, or the build-up of electrostatic charge. <p>The use of the complimentary pressure fluctuation and ECT measurement techniques have identified changes occurring as a result of the reduction of moisture during the drying process. Both the localized changes in the voidage fluctuations provided by the ECT imaging and the global changes shown by the pressure fluctuation measurements indicate significant changes in the dynamic behaviour caused by the reduction of moisture during the drying process. These measurement techniques could be utilized to provide an on-line indication of changes in hydrodynamic regime. This information may be invaluable for the future optimization of the batch drying process and accurate determination of the drying endpoint.

WHY SHOULD TURKEY CONTINUE WITH STRONG FISCAL ADJUSTEMENT? LESSONS DERIVED FROM THE PAST AgAR PASLI, Mediha M.S., Department of Economics Supervisor: Associate Prof. Dr. Nadir &Ouml / CAL November 2006, 87 pages Turkey managed to produce a strong fiscal adjustment during the period of 1999-2005 with the annual average of close to 5 percent. Moreover, with the help of this tight fiscal stance, Turkey&rsquo / s public debt has been reduced from the peak of 90.5 percent of GNP in 2001 to 55.8 percent in 2005. Although this is a major achievement both in terms of the size and the speed, the challenge for Turkey is now to continue with fiscal adjustment in order to further reduce its public debt level which still poses a sizeable vulnerability risk for the economy. Therefore, in order to provide an answer to the sustainability question, this thesis first aims to (i) measure the fiscal adjustment in Turkey at the general government level during 1999-2005 period, (ii) analyze sources of fiscal adjustment based on the economic classification, institutional breakdown, and cyclical and structural components. After understanding size and sources of adjustment, the reduction in public debt will be decomposed into its parts including the contribution come from primary surplus. This will shed light on whether Turkey could still rely on those factors for further reduction in public debt in the future.

ABSTRACT INFLATION TARGETING AND FISCAL DOMINANCE: EVIDENCE FROM TURKEY SEL, TUgBA M.Sc., Department of Economics Supervisor: Prof. Dr. Erdal &Ouml / zmen September 2007, 60 pages. This study investigates the significance of fiscal dominance for an inflation targeting regime in the context of the recent Turkish experience. To this end, capital flows and country risk equations are estimated for the Turkish monthly data pertaining the inflation targeting regime implementation period. The results from the capital flows models based on portfolio approach strongly suggest that the real effective exchange rates in Turkey during the period are determined by foreign interest rates and the Emerging Markets Bond Index (EMBI) but not by the domestic interest rates in the long run. This supports the view that the risk premium channel dominates the standard portfolio channel in the determination of real exchange rates in Turkey during the period. The country risk of Turkey, proxied by the EMBI spread in the long run is determined by risk appetite of foreign investors and domestic variables including real debt stock, real consolidated budget balance, international gross reserves, current account deficits and credit ratings. All these results are found to be important manifestations of the presence fiscal dominance in Turkey. Consequently, contrary to the postulations of the conventional monetary policy transmission mechanism, interest rate increases to cope with inflationary pressures may lead to an inflation acceleration, rather than the reverse.

This study aims to analyze the causes and consequences of sudden stops in international capital flows with special reference to the recent Turkish experience. We aim to investigate also the vulnerability of the Turkish economy to a sudden stop and compute the required change in the real exchange rates for a current account adjustment in the face of a sudden stop. The assessment of the economic and structural indicators, which are assumed to be related with the resilience of the economy against sudden stops, such as openness and dollarization, refers that the risk of experiencing a sudden stop has increased in Turkey in the last two years, despite a decrease in its exposure to the destructive effects of such shocks thanks to the structural improvements in the economy. Our empirical results based on a small open economy model with tradables and non-tradables suggest that a sudden stop that requires the closing of the current account imbalance in Turkey would necessitate a real depreciation of around 36 percent as of May 2008 under the assumption that international reserves were not used in order to mitigate the level and the effects of the adjustment. Although the effects of such a real depreciation may be milder due to the decreased currency mismatches in the public and banking sector, there is still the risk of experiencing a financial crisis following a sudden stop because of the high liability dollarization in the real sector.

This thesis analyses the Spanish financial system and foreign policy from a political economy point of view. The foundation, development and transformation of the financial elite in Spain and its affiliations with the policy-making elite are the main concerns of this study. The traditionally complex and interlocking relationship between the financial elite and the policy-making elite in Spain is a perfect showcase to demonstrate how policy and economy affect each other interchangeably. The financial system of Spain has always been highly oligopolistic which led to the continuation of its traditional political and economical protection for many decades before, during and after the liberalisation process went underway. This traditional protection has a very unique characteristic given the fact that it survived nearly a century, under a succession of various political and regulatory regimes with very different ideological agendas. &ldquo / How could the banking sector preserve its power and influence under many different political ideals and economic orientations&rdquo / is one the questions to which an answer is sought in this study. Naturally, this answer also covers the origins and structure of the power and influence that the financial elite held over the domestic and foreign policies of the country. Also, the mutual and complex relationship between economy and foreign policy as well as policy-making elite and economic elite, is analysed in this thesis. In other words, the consequences of the shifts in foreign and domestic policy agendas on the Spanish financial elite are studied.

In the first part of this thesis the prices of six non-ferrous metals (aluminum, copper, lead, nickel, tin, and zinc) are used to assess the forecasting performance of GARCH models. We find that the forecasting performances of GARCH, EGARCH, and TGARCH models are similar. However, we suggest the use of the GARCH model because it is more parsimonious and has a slightly better statistical performance than the other two. In the second part, the prices of six non-ferrous metals and the price of crude oil are used to examine the dynamic links between oil and metal returns by using the BEKK specification of the multivariate GARCH model and the Granger causality-in-variance tests. Results of our study agree with the previous studies in that the crude oil market volatility leads all non-ferrous metal markets. In order to move as far away from the effects of 9/11, daily data for the period December 12, 2003 &ndash / December 15, 2008 is used for the data analysis part of the thesis.

This thesis investigates the nature of macroeconomic changes by focussing on the monetary policy changes in Turkey between 1990Q1-2011Q4 and assesses the variability of the economy via impulse response functions obtained from VAR analyses. The period of the analyses is characterized with changes of the definitions of monetary aggregates in 2002 and 2007. In order to have consistent monetary series, the new and old series are constructed according to new and old definitions and then analyses are carried out with each type of series and comparisons are given among the monetary series.