Browsing by Subject "johdannaiset"

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  • Mäenpää, Tiina (Helsingfors universitet, 2017)
    The aim of this thesis was to synthesize abietic acid derivatives, and to determine their antimicrobial activity. The study was performed in two parts. The first part was carried out at VTT (Technical Research Centre of Finland) and the second part at the Faculty of Pharmacy, University of Helsinki, the Division of Pharmaceutical Chemistry and Technology. Abietic acid as well as its isomers and precursors are important antimicrobial substances among plant kingdom. They are produced in big scale by conifers, which extractives of pitch and wood they are. Abietic acid and its many derivatives have shown to have many bioactivities. Emerging antibiotic resistance of bacteria, viral diseases that are spreading and mutating throughout the world and serious diseases caused by protozoa, cause an ever-growing need to develop new active agents against these pathogens. Abietic acid derivatives are worthy candidates for research into new drug substances. At VTT a synthetic route with abietic acid chloride as intermediate was used (synthetic route 1). It did not work well in the synthesis of esters and yields were low. The synthetic route worked fairly well for amide synthesis. The purifications and analysis of the compounds, two esters and one amide of abietic acid, were left partially unfinished, and none of the products of these reactions were tested for bioactivity. At the Division of Pharmaceutical Chemistry and Technology eight derivatives of abietic acid, from abietic acid and four different amino acids, were obtained via synthetic route 2. Some of these were sent to tests for antibacterial activity. Six synthesized compounds were sent to tests for their bioactivity against bacteria. However, the results were not obtained in time for this Master's thesis, and therefore any conclusions of their structure-activity relationships could not be drawn.
  • Harrinkari, Teemu (Helsingfors universitet, 2013)
    In this research it was studied whether non-industrial private forest owners are interested in using timber sales contracts which pricing is based on the nominal stumpage price indices published by the Finnish Forest Research Institute. In addition, it was studied, whether forest owners’ background and objectives of ownership affect the forest owners’ attitudes towards this type of timber sales contracts. Six different models of timber sales contracts were created for the research purposes. The Data consists of 16 non-industrial private forest owners from southern Finland who were interviewed with a semi-structured interview and a questionnaire. Theoretical sampling was used to select different forest owners with respect to their age, profession, gender, domicile and amount of forestland owned. The results suggest that forest owners can be classified into three groups with respect to their interest in a certain contract model. The groups are: risk takers, active sellers and investors. Risk takers were interested in the contract models which allow them to speculate with the future developments of the prices. Risk takers were typically absentee owners owning relatively small-sized forest holdings. Their dependency on forestry income was typically relatively small. Active sellers typically owned large forest holdings and were usually more dependent on timber sales income known with certainty. They were also familiar with the timber selling process which partly explains why they were usually less interested in the models. Investors were typically only interested in the contract models that allowed them to avoid or minimize risk related to the timing of timber sales. Even though timber buyers nowadays offer various types of contracts, it would benefit the timber markets as a whole if there were more flexible nad transparent ways to tailor timber sales contracts for the different types of forest owners. This would have impact especially to absentee owners owning small-sized forest holdings, who either are uncertain on the timing of the sale or appreciate opportunities to speculate with the stumpage price developments. Standardizing the pricing methods of the contracts would enhance the transparency of the pricing of the contracts and increase trust in the whole selling process.
  • Salomaa, Sanna Kaisa (2001)
    Riskienhallinnan avulla yritys pyrkii pienentämään liiketoimintaansa liittyviä riskejä. Tässä pro gradu ?tutkielmassa keskitytään tarkastelemaan hintojen ja kurssien vaihtelulta eli markkinariskiltä suojautumista osana yrityksen riskienhallintaa ja pyritään arvioimaan toiminnan hyödyllisyyttä yrityksen omistajien kannalta. Täydellisillä pääomamarkkinoilla yrityskohtainen markkinariskiltä suojautuminen ei vaikuta yrityksen arvoon, mutta markkinoiden ollessa epätäydelliset suojautuminen voi nostaa yrityksen arvoa. Epäsymmetrinen informaatio, transaktiokustannukset ja verot aiheuttavat yritykselle kustannuksia, joita se suojautumalla voi alentaa. Epäsymmetrisestä informaatiosta yrityksen ja ulkopuolisten rahoittajien välillä aiheutuvia rahoituskustannuksia voidaan suojautumalla alentaa, jolloin niiden vaikutus yrityksen investointiasteeseen ja pääomarakenteeseen vähenee. Suojautumalla voidaan vaikuttaa myös agentuurikustannuksiin, joita syntyy omistajien ja ulkopuolisten rahoittajien ja toisaalta omistajien ja johdon välisistä intressiristiriidoista. Edellä mainittuja hyötyjä ei synny, jos johto tai omistajat suojautuvat omaan lukuunsa. Suojautumisella tarkoitetaan yrityksen arvon riippuvuuden vähentämistä satunnaismuuttujien muutoksista ja se toteutetaan tavallisimmin suojaamalla tulevia kassavirtoja johdannaisten avulla. Tietyin oletuksin optimaalinen suojausaste voidaan yksikäsitteisesti ratkaista ja yksinkertaisimmassa tapauksessa yrityksen kannattaa suojata kaikki tulevat kassavirtansa. Yleisemmillä oletuksilla yrityksen arvon maksimoivaa suojausastetta ei yksikäsitteisesti voida ratkaista. Empiiristen tutkimusten valossa tärkeimpiä suojautumispäätökseen vaikuttavia tekijöitä näyttävät olevan yrityksen käytössä olevat resurssit sekä edellytykset vähentää riskiä käytettävissä olevien instrumenttien avulla. Empiiristen tutkimusten ongelmana on tosin tutkimusaineiston niukka saatavuus sekä muuttujien määrittelyyn liittyvät kysymykset. Yrityskohtainen markkinariskiltä suojautuminen voi siis tietyin edellytyksin nostaa yrityksen arvoa ja olla näin omistajien kannalta hyödyllistä toimintaa. Oleellista on arvioida saavutettavia hyötyjä suhteessa kustannuksiin, koska yrityksen arvon maksimoivaa suojausastetta ei välttämättä voida yksikäsitteisesti ratkaista ja koska suojaustoiminnan perustaminen ja sen ylläpitäminen vaatii resursseja.