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Sosiaalipsykologia

Sosiaalipsykologiassa tutkitaan, miten sosiaalinen maailma ja yksittäiset ihmiset vaikuttavat toisiinsa ja muovaavat toisiaan. Tieteenalana se sijoittuu sosiologian ja psykologian välimaastoon. Tiedekuntaan oppiaineen laitos perustettiin vuonna 1962. Tehtävänsä mukaisesti tiedekunnan kirjasto on aineistohankinnoillaan tukenut siitä pitäen alalla harjoitettavaa tutkimustyötä sekä opetusta perusopinnoista väitöskirjan tekoon, joten kokoelmassa on sosiaalipsykologian eri suuntautumisvaihtoehtojen kirjallisuutta harjoitetun tutkimuksen ja opetuksen painopisteiden mukaisesti. Osa kokoelman nimekkeistä on pikemminkin psykologian kuin sosiaalipsykologian alaan kuuluvia. Ajan kuluessa tutkimuksen painopisteet ovat tiedekunnassa vaihdelleet, mikä näkyy kokoelman sisällössä ja rakenteessa. Sosiaalisen vuorovaikutuksen tutkiminen on keskeinen teema alusta alkaen. Siihen sisältyen on tutkittu sosiaalisia suhtautumistapoja, keskustelua ja emootioita. 1970-luvulla kiinnostuksen kohteeksi nousivat sosialisaatio ja moraalinen sosialisaatio erityisesti, etninen identiteetti ja ryhmien väliset suhteet sekä terveyden sosiaalipsykologia. 1990-luvun alussa laitos koordinoi laajaa pohjoismaista ja poikkitieteellistä tutkimushanketta energiankäytöstä. Uusimpia aihealueita on maaseutututkimus. Helsingin yliopiston valtiotieteellisen kirjaston kokoelmassa on kaikkiaan 2800 nimekettä (26.6.2008 tehdyn Access-haun mukaan). Systemaattisella satunnaisotannalla kokoelmaa läpikäytäessä kävi ilmi, että noin 2/3 kirjoista on luokiteltavissa tieteellisiksi tutkimuksiksi, noin 15% oppikirjoiksi ja loput ns. yleisteoksiksi. Kirjoista 1173 eli 42% on julkaistu vuonna 1990 tai jälkeen. Mediaani on 1988. Vuosikategorioittain tarkasteltuna kokoelma on karttunut eniten 1980-luvulla ilmestyneistä nimikkeistä (35%). Nimekkeistä valtaosa on englanninkielisiä eli 78%. Suomeksi julkaistuja on 429 eli 15%.

De cupro albo Sinensi

Arkit: 1 arkintunnukseton lehti, I-K4 L2.

De fine miraculorum in Novo Testamento enarratorum

Arkit: 1 arkintunnukseton lehti, A-B4 C1.

Oxidation rates of carbon and nitrogen in char residues from solid fuels

Computational fluid dynamics (CFD) modeling is an important tool in designing new combustion systems. By using CFD modeling, entire combustion systems can be modeled and the emissions and the performance can be predicted. CFD modeling can also be used to develop new and better combustion systems from an economical and environmental point of view. In CFD modeling of solid fuel combustion, the combustible fuel is generally treated as single fuel particles. One of the limitations with the CFD modeling concerns the sub-models describing the combustion of single fuel particles. Available models in the scientific literature are in many cases not suitable as submodels for CFD modeling since they depend on a large number of input parameters and are computationally heavy. In this thesis CFD-applicable models are developed for the combustion of single fuel particles. The single particle models can be used to improve the combustion performance in various combustion devices or develop completely new technologies. The investigated fields are oxidation of carbon (C) and nitrogen (N) in char residues from solid fuels. Modeled char-C oxidation rates are compared to experimental oxidation rates for a large number of pulverized solid fuel chars under relevant combustion conditions. The experiments have been performed in an isothermal plug flow reactor operating at 1123-1673 K and 3-15 vol.% O2. In the single particle model, the char oxidation is based on apparent kinetics and depends on three fuel specific parameters: apparent pre-exponential factor, apparent activation energy, and apparent reaction order. The single particle model can be incorporated as a sub-model into a CFD code. The results show that the modeled char oxidation rates are in good agreement with experimental char oxidation rates up to around 70% of burnout. Moreover, the results show that the activation energy and the reaction order can be assumed to be constant for a large number of bituminous coal chars under conditions limited by the combined effects of chemical kinetics and pore diffusion. Based on this, a new model based on only one fuel specific parameter is developed (Paper III). The results also show that reaction orders of bituminous coal chars and anthracite chars differ under similar conditions (Paper I and Paper II); reaction orders of bituminous coal chars were found to be one, while reaction orders of anthracite chars were determined to be zero. This difference in reaction orders has not previously been observed in the literature and should be considered in future char oxidation models. One of the most frequently used comprehensive char oxidation models could not explain the difference in the reaction orders. In the thesis (Paper II), a modification to the model is suggested in order to explain the difference in reaction orders between anthracite chars and bituminous coal chars. Two single particle models are also developed for the NO formation and reduction during the oxidation of single biomass char particles. In the models the char-N is assumed to be oxidized to NO and the NO is partly reduced inside the particle. The first model (Paper IV) is based on the concentration gradients of NO inside and outside the particle and the second model is simplified to such an extent that it is based on apparent kinetics and can be incorporated as a sub-model into a CFD code (Paper V). Modeled NO release rates from both models were in good agreement with experimental measurements from a single particle reactor of quartz glass operating at 1173-1323 K and 3-19 vol.% O2. In the future, the models can be used to reduce NO emissions in new combustion systems.

Wood biochemicals for the protection of health. Focus on hemicellulose, stilbenoids and lignans

Trees produce an enormous amount of compounds that are still scantly utilized.However, the results obtained from structurally similar biochemicals suggest that wood-derived compounds could be used for the protection of health in various applications. Polyphenols, for instance, could be extracted from wood in high quantities. Similar polyphenols to those in wood include resveratrol, found in grapes, and secoisolariciresinol, present in flaxseeds. Their consumption has been inversely associated with the incidence of various diseases, especially certain cancers and obesity-related disorders. The aim of this study was to determine the health-promoting effects of woodderived biochemicals. The effect of spruce hemicellulose on the growth of probiotic intestinal bacteria was studied. The results suggest that the bifidobacteria and lactobacilli can utilize hemicellulose and thus it has potential as a prebiotic compound. In particular, the efficacy of pine polyphenols to inhibit the growth of prostate cancer was our main interest. It was found that stilbenoids and lignans inhibited the proliferation of various cancer cells, and reduced the growth of prostate cancer xenografts in mice. The polyphenol rich pine knot extract was well tolerated in diet and extract-derived polyphenols were rapidly absorbed after intake. Furthermore, we determined the effect of the dietary pine knot extract on the weight gain and the expression of aromatase gene in reporter mouse expressing the promoter region of a human aromatase gene. It was found that dietary pine knot extract alleviated the obesity-induced inflammation in adipose tissue and downregulated the expression of a human aromatase gene. Taken together, several components of spruce and pine may have a future role as health-promoting compounds.