7 resultados para Protection by p-cycles

em Doria (National Library of Finland DSpace Services) - National Library of Finland, Finland


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Bullying can be viewed as goal-oriented behavior in the strive for dominance and prestige in the peer group (Salmivalli, 2010). To ensure the effectiveness of their power demonstrations, bullies often choose targets from among their vulnerable peers (Salmivalli, 2010; Veenstra et al., 2007). A large number of studies have also shown that victimization has severe consequences for the victims’ psychosocial adjustment (Reijntjes, Kamphuis, Prinzie, & Telch, 2010; Ttofi, Farrington, Lösel, & Loeber, 2011). In this thesis I investigate – based on three empirical studies – whether similar dynamics on the risk factors and consequences apply to same- and other-sex victimization. In the empirical studies, we used the data from the randomized control trial of the KiVa antibullying program for the elementary school grades 4–6 (2007–2008), and for the middle school grades 7–9 (2008–2009). We measured same- and other-sex victimization, and victims’ defending relationships by dyadic questions: “By which classmates are you victimized?” and “By which classmates are you supported, comforted, or defended?” In addition, we used self-reports and peer reports to measure adjustment and social status. The findings imply that other-sex victimization may be challenging for antibullying work. First, although targets of bullying seemed to be selected from among vulnerable peers for the most part, perceived popularity increased the risks of other-sex victimization. Popularity of these victims may falsely lead to an impression that the victims are doing well. Second, the consequences considering victims’ later psychosocial adjustment were alarming concerning girls bullied by boys. Thus, despite the fact that the targets may be perceived as popular, other-sex victimization can have even more severe consequences than same-sex victimization. Third, we found that defending relationships were mostly same-sex relationships, and consequently, we may ask whether defending is effective against other-sex bullies. Finally, the KiVa antibullying program was less effective against other-sex victimization in the adolescent sample. The findings altogether emphasize the importance of taking into account the sex composition of the bully-victim dyad, both considering future research on bullying and in the antibullying work with children and adolescents.

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Työssä selvitettiin vastusvenymäliuskamittausten avulla sekoitinakselin kuormitukset sekä perehdyttiin väsymisilmiöön ja hitsattujen rakenteiden väsymismitoitukseen. Kuormitusten mittauksessa rekisteröitiin akselin kriittisen kohdan taivutus- ja vääntövenymät. Mittaustulosten avulla tutkittiin kuormituksia ja kuormitusten luonnetta sekä johdettiin väsymismitoitusperusteet sekoitinakseleille. Väsymismitoitus perustuu kahteen eri menetelmään. Vakioamplitudiseen väsymisrajaan perustuvassa menetelmässä vaihtuva-amplitudisella jännityksellä suurinkin jännitysheilahdus jää väsymisrajan alle. Kokonaisväsymisvaurioon perustuvassa mitoituksessa puolestaan sallitaan vakioamplitudisen väsymisrajan ylitys. Kestoikä on käytetty loppuun, kun väsymisvaurio saavuttaa väsymiskestävyyden arvon. Menetelmän valinta riippuu käytettävästä sekoitinelintyypistä ja käytön aikana ilmenevistä väsymisen kannalta vaarallisista tilanteista.

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This PhD thesis in Mathematics belongs to the field of Geometric Function Theory. The thesis consists of four original papers. The topic studied deals with quasiconformal mappings and their distortion theory in Euclidean n-dimensional spaces. This theory has its roots in the pioneering papers of F. W. Gehring and J. Väisälä published in the early 1960’s and it has been studied by many mathematicians thereafter. In the first paper we refine the known bounds for the so-called Mori constant and also estimate the distortion in the hyperbolic metric. The second paper deals with radial functions which are simple examples of quasiconformal mappings. These radial functions lead us to the study of the so-called p-angular distance which has been studied recently e.g. by L. Maligranda and S. Dragomir. In the third paper we study a class of functions of a real variable studied by P. Lindqvist in an influential paper. This leads one to study parametrized analogues of classical trigonometric and hyperbolic functions which for the parameter value p = 2 coincide with the classical functions. Gaussian hypergeometric functions have an important role in the study of these special functions. Several new inequalities and identities involving p-analogues of these functions are also given. In the fourth paper we study the generalized complete elliptic integrals, modular functions and some related functions. We find the upper and lower bounds of these functions, and those bounds are given in a simple form. This theory has a long history which goes back two centuries and includes names such as A. M. Legendre, C. Jacobi, C. F. Gauss. Modular functions also occur in the study of quasiconformal mappings. Conformal invariants, such as the modulus of a curve family, are often applied in quasiconformal mapping theory. The invariants can be sometimes expressed in terms of special conformal mappings. This fact explains why special functions often occur in this theory.

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Tutkielman tarkoituksena on perehtyä siihen, kuinka laajasti tavaramerkin haltija voi kieltää toista elinkeinoharjoittajaa käyttämästä samaa tai samankaltaista merkkiä, kun sitä käytetään samoissa, samankaltaisissa tai jopa täysin erilaisissa tavaroissa tai palveluissa. Merkin haltijan kielto-oikeuden laajuuteen paneudutaan tutkimalla ensiksi EU:n tavaramerkkidirektiiviä ja Suomen tavaramerkkilakia ja oikeuskäytäntöjä. Tämän jälkeen tutkitaan, kuinka laaja kielto-oikeus merkin haltijalla on Kiinassa. Pääasiallinen tutkimusmetodi on lainopillinen, mutta myös oikeusvertailua tehdään Suomen ja Kiinan välillä. Tavaramerkin suojaamisessa on Suomessa selkeästi havaittavissa Chicagon koulukunnan teorian hyväksyminen, joka tavaramerkkioikeuteen sovellettuna korostaa merkin haltijan laajaa suojaa. Teorian mukaan tavaramerkin brandiksi luomiseen liittyviä investointeja pitää suojata ja estää sen ansioton hyödyntäminen. Päinvastaista teoriaa edustaa Harvardin koulukunta, jonka teorian piirteitä on havaittavissa Kiinan tavaramerkkioikeudessa. Se korostaa tavaramerkin kapeaa suojaa. Sallimalla kilpailijoiden jäljitellä tunnettua tavaramerkkiä parannetaan kilpailijan asemaa markkinoilla. Toisaalta ulkomaiset merkin haltijat kohtaavat Kiinassa myös paljon ei-tavaramerkkioikeudellisia ongelmia, jotka vaikeuttavat tavaramerkin suojaamista Kiinan markkinoilla.

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In recent years, there have been studies that show a correlation between the hyperactivity of children and use of artificial food additives, including colorants. This has, in part, led to preference of natural products over products with artificial additives. Consumers have also become more aware of health issues. Natural food colorants have many bioactive functions, mainly vitamin A activity of carotenoids and antioxidativity, and therefore they could be more easily accepted by the consumers. However, natural colorant compounds are usually unstable, which restricts their usage. Microencapsulation could be one way to enhance the stability of natural colorant compounds and thus enable better usage for them as food colorants. Microencapsulation is a term used for processes in which the active material is totally enveloped in a coating or capsule, and thus it is separated and protected from the surrounding environment. In addition to protection by the capsule, microencapsulation can also be used to modify solubility and other properties of the encapsulated material, for example, to incorporate fat-soluble compounds into aqueous matrices. The aim of this thesis work was to study the stability of two natural pigments, lutein (carotenoid) and betanin (betalain), and to determine possible ways to enhance their stability with different microencapsulation techniques. Another aim was the extraction of pigments without the use of organic solvents and the development of previously used extraction methods. Stability of pigments in microencapsulated pigment preparations and model foods containing these were studied by measuring the pigment content after storage in different conditions. Preliminary studies on the bioavailability of microencapsulated pigments and sensory evaluation for consumer acceptance of model foods containing microencapsulated pigments were also carried out. Enzyme-assisted oil extraction was used to extract lutein from marigold (Tagetes erecta) flower without organic solvents, and the yield was comparable to solvent extraction of lutein from the same flowers. The effects of temperature, extraction time, and beet:water ratio on extraction efficiency of betanin from red beet (Beta vulgaris) were studied and the optimal conditions for maximum yield and maximum betanin concentration were determined. In both cases, extraction at 40 °C was better than extraction at 80 °C and the extraction for five minutes was as efficient as 15 or 30 minutes. For maximum betanin yield, the beet:water ratio of 1:2 was better, with possibly repeated extraction, but for maximum betanin concentration, a ratio of 1:1 was better. Lutein was incorporated into oil-in-water (o/w) emulsions with a polar oil fraction from oat (Avena sativa) as an emulsifier and mixtures of guar gum and xanthan gum or locust bean gum and xanthan gum as stabilizers to retard creaming. The stability of lutein in these emulsions was quite good, with 77 to 91 percent of lutein being left after storage in the dark at 20 to 22°C for 10 weeks whereas in spray dried emulsions the retention of lutein was 67 to 75 percent. The retention of lutein in oil was also good at 85 percent. Betanin was incorporated into the inner w1 water phase of a water1-in-oil-inwater2 (w1/o/w2) double emulsion with primary w1/o emulsion droplet size of 0.34 μm and secondary w1/o/w2 emulsion droplet size of 5.5 μm and encapsulation efficiency of betanin of 89 percent. In vitro intestinal lipid digestion was performed on the double emulsion, and during the first two hours, coalescence of the inner water phase droplets was observed, and the sizes of the double emulsion droplets increased quickly because of aggregation. This period also corresponded to gradual release of betanin, with a final release of 35 percent. The double emulsion structure was retained throughout the three-hour experiment. Betanin was also spray dried and incorporated into model juices with different pH and dry matter content. Model juices were stored in the dark at -20, 4, 20–24 or 60 °C (accelerated test) for several months. Betanin degraded quite rapidly in all of the samples and higher temperature and a lower pH accelerated degradation. Stability of betanin was much better in the spray dried powder, with practically no degradation during six months of storage in the dark at 20 to 24 °C and good stability also for six months in the dark at 60 °C with 60 percent retention. Consumer acceptance of model juices colored with spray dried betanin was compared with similar model juices colored with anthocyanins or beet extract. Consumers preferred beet extract and anthocyanin colored model juices over juices colored with spray dried betanin. However, spray dried betanin did not impart any off-odors or off-flavors into the model juices contrary to the beet extract. In conclusion, this thesis describes novel solvent-free extraction and encapsulation processes for lutein and betanin from plant sources. Lutein showed good stability in oil and in o/w emulsions, but slightly inferior in spray dried emulsions. In vitro intestinal lipid digestion showed a good stability of w1/o/w2 double emulsion and quite high retention of betanin during digestion. Consumer acceptance of model juices colored with spray dried betanin was not as good as model juices colored with anthocyanins, but addition of betanin to real berry juice could produce better results with mixture of added betanin and natural berry anthocyanins could produce a more acceptable color. Overall, further studies are needed to obtain natural colorants with good stability for the use in food products.