Stabilization of the ionic form of weak acid cation exchange resins

Weak acid cation exchange (WAC) resins are used in the chromatographic separation of betaine from vinasse, a by-product of sugar industry. The ionic form of the resin determines the elution time of betaine. When a WAC-resin is in hydrogen form, the retention time of betaine is the longest and betaine elutes as the last component of vi-nasse from the chromatographic column. If the feed solution contains salts and its pH is not acidic enough to keep the resin undissociated, the ionic form of the hydrogen form resin starts to alter. Vinasse contains salts and its pH is around 5, it also contains weak acids. To keep the metal ion content (Na/H ratio) of the resin low enough to ensure successful separation of betaine, acid has to be added to either eluent (water) or vinasse. The aim of the present work was to examine by laboratory experiments which option requires less acid. Also the retention mechanism of betaine was investigated by measuring retention volumes of acetic acid and choline in different Na/H ratios of the resin. It was found that the resulting ionic form of the resin is the same regardless of whether the regeneration acid is added to the eluent or the feed solution (vinasse). Be-sides the salt concentration and the pH of vinasse, also the concentration of weak acids in the feed affects the resulting ionic form of the resin. The more buffering capacity vinasse has, the more acid is required to keep the ionic form of the resin desired. Vinasse was found to be quite strong buffer solution, which means relatively high amounts of acid are required to prevent the Na/H ratio from increasing too much. It is known that the retention volume of betaine decreases significantly, when the Na/H ratio increases. This is assumed to occur, because the amount of hydrogen bonds between the carboxylic groups of betaine and the resin decreases. Same behavior was not found with acetic acid. Choline has the same molecular structure as betaine, but instead of carboxylic group it has hydroxide group. The retention volume of choline increased as the Na/H ratio of the resin increased, because of the ion exchange reaction between choline cation and dissociated carboxylic group of the resin. Since the retention behavior of choline on the resin is opposite to the behavior of be-taine, the strong affinity of betaine towards hydrogen form WAC-resin has to be based on its carboxylic group. It is probable that the quaternary ammonium groups also affect the behavior of the carboxylic groups of betaine, causing them to form hydrogen bonds with the carboxylic groups of the resin.

Arvostrategioiden menestys Suomen osakemarkkinoilla

Tämän tutkimuksen tavoitteena on selvittää saavutetaanko passiivisilla arvostrategioilla riskikorjattuna ylisuuria tuottoja Suomen osakemarkkinoilla. Tuottaako matalien tunnuslukujen perusteella valittujen osakkeiden portfolio enemmän kuin korkeiden tunnuslukujen portfolio? Ovatko alfat tilastollisesti merkitseviä? Tutkimuksen tavoitteena on myös selvittää, ovatko korkeimman ja matalimman arvostustason portfolioiden menestyserot tilastollisesti merkitseviä. Tunnuslukuina on tarkasteltu P/E-, EV/EBIT- ja EV/EBITDA-tunnuslukuja sekä P/B- ja P/S–lukuja. Lisäksi on tutkittu yhdistelmätunnuslukuina P/E- ja P/B–lukujen tulon muodostamaa tunnuslukua, sekä suhteellisiin EV/EBITDA-, P/B- ja P/S-lukuihin perustuvaa arvostusmittaria. Tutkimusaineisto koostuu Suomen osakemarkkinoilla julkisesti noteeratuista yrityksistä toukokuusta 1991 toukokuuhun 2006. Osakkeet järjestettiin tunnuslukujen arvostustason perusteella kvintiiliportfolioihin. Myöhemmin portfoliot muodostettiin uudelleen kolmen ja viiden vuoden välein. Lopuksi tarkasteltiin kvintiiliportfolioiden kuukausittaisia tuottoja tunnuslukukohtaisesti koko tutkimusjakson ajalta. Tulosten perusteella on selkeästi havaittavissa, että matalan tunnusluvun kvintiiliportfoliot menestyivät paremmin kuin korkean tunnusluvun kvintiiliportfoliot. Kolmen vuoden jaksoissa P/E-, EV/EBITDA-, P/B-, P/S- ja kolmen tunnusluvun yhdistelmällä muodostetuilla kvintiiliportfolioilla arvopreemio oli selkeästi havaittavissa. Viiden vuoden jaksoissa vastaava ilmiö toistui EV/EBITDA-tunnusluvulla muodostetuilla kvintiiliportfolioilla. Eniten tuotti absoluuttisesti sekä riskikorjattuna tutkimuksessa esiteltävä kolmen vuoden jaksoissa kolmen tunnusluvun yhdistelmällä muodostettu matalimman arvostustason kvintiiliportfolio, joka tuotti riskikorjattuna tilastollisesti erittäin merkitsevästi positiivista alfaa matalalla riskitasolla.

Time-varying Risk Premiums and Conditional Market Risk: Empirical Evidence from European Stock Markets

This study investigates the relationship between the time-varying risk premiums and conditional market risk in the stock markets of the ten member countries of Economy and Monetary Union. Second, it examines whether the conditional second moments change over time and are there asymmetric effects in the conditional covariance matrix. Third, it analyzes the possible effects of the chosen testing framework. Empirical analysis is conducted using asymmetric univariate and multivariate GARCH-in-mean models and assuming three different degrees of market integration. For a daily sample period from 1999 to 2007, the study shows that the time-varying market risk alone is not enough to explain the dynamics of risk premiums and indications are found that the market risk is detected only when its price is allowed to change over time. Also asymmetric effects in the conditional covariance matrix, which is found to be time-varying, are clearly present and should be recognized in empirical asset pricing analyses.

Context exchange between devices in mobile environment

Context awareness is emerging on mobile devices. Context awareness can be used to improve usability of a mobile device. Context awareness is particularly important on mobile devices due the limitations they have. At first in this work, a literature review on context awareness and mobile environment is made. For aiding context awareness there exist an implementation of a Context Framework for Symbian S60 devices. It provides a possibility for exchanging the contexts inside the device between the client applications of the local Context Framework. The main contribution of this thesis is to design and implement an enhancement to the S60 Context Framework for providing possibility to exchange context over device boundaries. Using the implemented Context Exchange System, the context exchange is neither depending on the type of the context nor the type of the client. In addition, the clients and the contexts can reside on any interconnected device. The usage of the system is independent of the programming language since in addition to using only Symbian C++ function interfaces it can also be utilized using XML scripts. The Meeting Sniffer application, which uses the Context Exchange System, was also developed in this work. Using this application, it is possible to recognize a meeting situation and suggest device profile change to a user.

Comovement of stock price risk in strategic alliance — Case: mobile internet

The focus of this study has been comovement of stock price risk level between two companies as they form strategic alliance. Thus the main reason has been to shed more light to possible increased risk level that the stockholder confronts when a company he owns forms a strategic alliance with another company. This study has centralized to interfirm cooperation between mobile and internet companies, which have furthered the development of mobile internet. The study has been divided into theoretical and empirical part. In theoretical part the main concepts riskiness of a stock (volatility), comovement and strategic alliance have been run through. In empirical part seven strategic alliances formed by mobile internet companies have been examined. Based on this, strategic alliance seems to increase comovement of stock price risk in some degree. This comovement seems to be stronger when core businesses or operating environments of cooperating companies differ more from each other.

Performance persistence of equity funds in the Russian stock market

This thesis investigates performance persistence among the equity funds investing in Russia during 2003-2007. Fund performance is measured using several methods including the Jensen alpha, the Fama-French 3- factor alpha, the Sharpe ratio and two of its variations. Moreover, we apply the Bayesian shrinkage estimation in performance measurement and evaluate its usefulness compared with the OLS 3-factor alphas. The pattern of performance persistence is analyzed using the Spearman rank correlation test, cross-sectional regression analysis and stacked return time series. Empirical results indicate that the Bayesian shrinkage estimates may provide better and more accurate estimates of fund performance compared with the OLS 3-factor alphas. Secondly, based on the results it seems that the degree of performance persistence is strongly related to length of the observation period. For the full sample period the results show strong signs of performance reversal whereas for the subperiod analysis the results indicate performance persistence during the most recent years.

VIX as a stock market indicator

The goal of this research was to make an overall sight to VIX and how it can be used as a stock market indicator. Volatility index, often referred as the fear index, measures how much does it cost for investor to protect his/hers S&P 500 position from fluctuations with options. Over the relatively short history of VIX it has succesfull timing coordinator and it has told about the market state adding its own psychological view of the amount of fear and greed.

The Market Behavior of Emerging Stock Markets in Europe

This study investigates the over and underreaction effects in nine emerging stock markets of Europe. Especially, the possible behavioral aspects behind them are an area of interest. These aspects would link them strongly to behavioral finance. Second, our aim is to provide more evidence of the similar or dissimilar behavior in general among these countries. Third, the possibility to gain abnormal returns from these markets is also under investigation. Data from nine emerging stock market indexes in Europe is gathered from January 1, 1998 to January 1, 2008 to find answers to the stated questions. Studies for the over and underreaction effects are done using a variant of the event study methodology which in this case includes two different calculation methods for the expected returns. Studies are performed using 60 day time intervals. The results between the two different methods used are relatively similar concerning the over and underreaction effects. Another of the methods, however, suggests there to be behavioral aspects behind the effects interpreted. On the other hand, the another method does not support this suggestion. However, a conclusion can be made that the factors driving these countries' behavior are related to their geographical location and to the fact that they are emerging countries.

Testing the Random Walk Hypothesis on the Baltic Stock Markets

The purpose of the thesis is to analyze whether the returns of general stock market indices of Estonia, Latvia and Lithuania follow the random walk hypothesis (RWH), and in addition, whether they are consistent with the weak-form efficiency criterion. Also the existence of the day-of-the-week anomaly is examined in the same regional markets. The data consists of daily closing quotes of the OMX Tallinn, Riga and Vilnius total return indices for the sample period from January 3, 2000 to August 28, 2009. Moreover, the full sample period is also divided into two sub-periods. The RWH is tested by applying three quantitative methods (i.e. the Augmented Dickey-Fuller unit root test, serial correlation test and non-parametric runs test). Ordinary Least Squares (OLS) regression with dummy variables is employed to detect the day-of-the-week anomalies. The random walk hypothesis (RWH) is rejected in the Estonian and Lithuanian stock markets. The Latvian stock market exhibits more efficient behaviour, although some evidence of inefficiency is also found, mostly during the first sub-period from 2000 to 2004. Day-of-the-week anomalies are detected on every stock market examined, though no longer during the later sub-period.