Twelve Etudes, Op. 25

Soitinnus: Piano.

Size Effect and Notch Size Effect in Metal Fatigue

It is a well known phenomenon that the constant amplitude fatigue limit of a large component is lower than the fatigue limit of a small specimen made of the same material. In notched components the opposite occurs: the fatigue limit defined as the maximum stress at the notch is higher than that achieved with smooth specimens. These two effects have been taken into account in most design handbooks with the help of experimental formulas or design curves. The basic idea of this study is that the size effect can mainly be explained by the statistical size effect. A component subjected to an alternating load can be assumed to form a sample of initiated cracks at the end of the crack initiation phase. The size of the sample depends on the size of the specimen in question. The main objective of this study is to develop a statistical model for the estimation of this kind of size effect. It was shown that the size of a sample of initiated cracks shall be based on the stressed surface area of the specimen. In case of varying stress distribution, an effective stress area must be calculated. It is based on the decreasing probability of equally sized initiated cracks at lower stress level. If the distribution function of the parent population of cracks is known, the distribution of the maximum crack size in a sample can be defined. This makes it possible to calculate an estimate of the largest expected crack in any sample size. The estimate of the fatigue limit can now be calculated with the help of the linear elastic fracture mechanics. In notched components another source of size effect has to be taken into account. If we think about two specimens which have similar shape, but the size is different, it can be seen that the stress gradient in the smaller specimen is steeper. If there is an initiated crack in both of them, the stress intensity factor at the crack in the larger specimen is higher. The second goal of this thesis is to create a calculation method for this factor which is called the geometric size effect. The proposed method for the calculation of the geometric size effect is also based on the use of the linear elastic fracture mechanics. It is possible to calculate an accurate value of the stress intensity factor in a non linear stress field using weight functions. The calculated stress intensity factor values at the initiated crack can be compared to the corresponding stress intensity factor due to constant stress. The notch size effect is calculated as the ratio of these stress intensity factors. The presented methods were tested against experimental results taken from three German doctoral works. Two candidates for the parent population of initiated cracks were found: the Weibull distribution and the log normal distribution. Both of them can be used successfully for the prediction of the statistical size effect for smooth specimens. In case of notched components the geometric size effect due to the stress gradient shall be combined with the statistical size effect. The proposed method gives good results as long as the notch in question is blunt enough. For very sharp notches, stress concentration factor about 5 or higher, the method does not give sufficient results. It was shown that the plastic portion of the strain becomes quite high at the root of this kind of notches. The use of the linear elastic fracture mechanics becomes therefore questionable.

Kustannukset ja kannattavuus RFID- ja toiminnanohjausj��rjestelmien integrointiprojektissa

Maailmantalouden jyrkk�� lasku vuonna 2008 ajoi yritykset s����st��kuurille. S����st��j�� pyrit����n saamaan esimerkiksi automatisoimalla toimintoja. Yksi tapa luoda kustannuss����st��j�� on k��ytt���� RFIDteknologiaa varastoinnin toimien tehostukseen. T��m��n tutkimuksen p����asiallisena tavoitteena on ollut rakentaa yksinkertainen laskentamalli RFID- ja toiminnanohjausj��rjestelmien integrointiprojektin kustannusten ja kannattavuuden laskemiseen. Toisena tavoitteena on ollut selvitt����, mitk�� tekij��t vaikuttavat investoinnin kannattavuuteen. Tutkimus rajattiin tarkastelemaan varaston saapuvan tavaran vastaanoton prosessia ja sen toimintojen automatisointia RFID-j��rjestelm��n avulla. Laskentamalli muodostuu kolmesta osasta: investoinnin kokonaiskustannusten arvioinnista, investoinnista saatavien kustannuss����st��jen arvioinnista ja kannattavuuslaskelmista. Investointien kokonaiskustannusten arviointia varten rakennettiin luettelo yleisimmist�� kustannuslajeista. Investoinnista saatavien kustannuss����st��jen arviointi tehtiin analysoimalla nykyprosesseja ja etsim��ll�� niist�� toimintoja, jotka tehostuvat RFID-j��rjestelm��n avulla. Varsinaisina kannattavuuslaskentamenetelmin�� k��ytettiin investoinnin takaisinmaksuajan menetelm���� sek�� p����oman tuottoasteen menetelm����. Tutkimuksen tuloksena todettiin rakennetun laskentamallin soveltuvan hyvin investoinnin kustannusten ja kannattavuuden arviointiin. Samalla havaittiin yrityksen toimialan, saapuvien l��hetysten m����r��n ja l��hetysten rivim����r��n vaikuttavan merkitt��v��sti RFID- jatoiminnanohjausj��rjestelm��n integrointiprojektin kannattavuuteen.

Energiapuun haketuksen ja murskauksen kustannukset

Energiapuun tuotannossa puu on hienonnettava kuljettimille ja kattilaan sopivaan kokoon. T��m�� tehd����n Suomessa yleens�� joko mets��tien varressa v��livarastolla, keskitetyss�� terminaalissa tai voimalaitoksella. Puu hienonnetaan joko ter��vill�� terill�� hakettamalla tai tylpemmill�� ty��kaluilla murskaamalla. Hakkeessa on v��hemm��n k��sittely�� haittaavia pitki�� tikkuja ja sen valmistamiseen tarvittava energia on hiukan pienempi kuin murskaimilla. Viimeksi mainitulla on merkityst�� l��hinn�� karsittua puuta haketettaessa. Murskain puolestaan sallii enemm��n ep��puhtauksia raaka-aineessa, joten esimerkiksi kantoja k��sitell����n vain murskaimilla. T��ss�� tarkastellaan erityisesti pienpuun haketuksen ja murskauksen kustannuksia. Pienpuuta saadaan nuoren mets��n kunnostuksista ja ensiharvennuksista. Se voi olla joko karsimatonta kokopuuta tai karsittua rankaa. Kokonaiskustannukset pienpuun haketukselle tai murskaukselle ovat t��m��n tutkimuksen mukaan v��livarastolla noin 3,4 euroa/MWh ja terminaalilla tai voimalaitoksella noin 2 euroa/MWh. P����omakustannukset ovat pienpuulla tavallisesti 1-1,2 euroa/MWh, keskitetyll�� terminaalilla toimittaessa noin kolmanneksen v��hemm��n, jos p����omalle asetetaan 10% tuottovaatimus. Ty��voimakustannukset ovat 30-80 snt/MWh varaston ja laitteen koosta riippuen, k��ytt��energia dieselmoottoria k��ytett��ess�� noin 50 snt/MWh, s��hk��moottorilla noin 30 snt/MWh. Muut kulut, mm. huolto, ovat yhteens�� 40-80 snt/MWh. Energiapuun hankinnan kokonaiskustannuksista raaka-aineen hienontamisen osuus on 10-30% puutavaran lajista ja k��ytetyst�� ty��menetelm��st�� riippuen. Terminaaleilla ja voimalaitoksilla toimittaessa on usein kiinnitett��v�� huomiota melun- ja p��lyntorjuntaan. Muun muassa n��ist�� syist�� saattaa kiinte��, s��hk��k��ytt��inen murska olla sopiva sellaisiin kohteisiin, joissa k��sitelt��v��t m����r��t ovat suuria ja toiminta pysyv����. Melun ja p��lyn kunnollinen torjunta vaatii suuria rakenteita, joita on vaikea yhdist���� liikuteltaviin laitteisiin.

Hyperbolic type metrics and distortion of quasiconformal map pings

This Ph.D. thesis consists of four original papers. The papers cover several topics from geometric function theory, more specifically, hyperbolic type metrics, conformal invariants, and the distortion properties of quasiconformal mappings. The first paper deals mostly with the quasihyperbolic metric. The main result gives the optimal bilipschitz constant with respect to the quasihyperbolic metric for the M��obius self-mappings of the unit ball. A quasiinvariance property, sharp in a local sense, of the quasihyperbolic metric under quasiconformal mappings is also proved. The second paper studies some distortion estimates for the class of quasiconformal self-mappings fixing the boundary values of the unit ball or convex domains. The distortion is measured by the hyperbolic metric or hyperbolic type metrics. The results provide explicit, asymptotically sharp inequalities when the maximal dilatation of quasiconformal mappings tends to 1. These explicit estimates involve special functions which have a crucial role in this study. In the third paper, we investigate the notion of the quasihyperbolic volume and find the growth estimates for the quasihyperbolic volume of balls in a domain in terms of the radius. It turns out that in the case of domains with Ahlfors regular boundaries, the rate of growth depends not merely on the radius but also on the metric structure of the boundary. The topic of the fourth paper is complete elliptic integrals and inequalities. We derive some functional inequalities and elementary estimates for these special functions. As applications, some functional inequalities and the growth of the exterior modulus of a rectangle are studied.

Switchable Lanthanide Luminescence for Detection of Biomolecules

Binary probes are oligonucleotide probe pairs that hybridize adjacently to a complementary target nucleic acid. In order to detect this hybridization, the two probes can be modified with, for example, fluorescent molecules, chemically reactive groups or nucleic acid enzymes. The benefit of this kind of binary probe based approach is that the hybridization elicits a detectable signal which is distinguishable from background noise even though unbound probes are not removed by washing before measurement. In addition, the requirement of two simultaneous binding events increases specificity. Similarly to binary oligonucleotide probes, also certain enzymes and fluorescent proteins can be divided into two parts and used in separation-free assays. Split enzyme and fluorescent protein reporters have practical applications among others as tools to investigate protein-protein interactions within living cells. In this study, a novel label technology, switchable lanthanide luminescence, was introduced and used successfully in model assays for nucleic acid and protein detection. This label technology is based on a luminescent lanthanide chelate divided into two inherently non-luminescent moieties, an ion carrier chelate and a light harvesting antenna ligand. These form a highly luminescent complex when brought into close proximity; i.e., the label moieties switch from a dark state to a luminescent state. This kind of mixed lanthanide complex has the same beneficial photophysical properties as the more typical lanthanide chelates and cryptates - sharp emission peaks, long emission lifetime enabling time-resolved measurement, and large Stokes��� shift, which minimize the background signal. Furthermore, the switchable lanthanide luminescence technique enables a homogeneous assay set-up. Here, switchable lanthanide luminescence label technology was first applied to sensitive, homogeneous, single-target nucleic acid and protein assays with picomolar detection limits and high signal to background ratios. Thereafter, a homogeneous four-plex nucleic acid array-based assay was developed. Finally, the label technology was shown to be effective in discrimination of single nucleotide mismatched targets from fully matched targets and the luminescent complex formation was analyzed more thoroughly. In conclusion, this study demonstrates that the switchable lanthanide luminescencebased label technology can be used in various homogeneous bioanalytical assays.

Laserpohjaisen ainetta lis����v��n menetelm��n kykenevyys kapeiden muotojen sek�� ter��vien kulmien valmistuksessa

T��ss�� ty��ss�� tarkastellaan laserpohjaisen ainetta lis����v��n ty��st��n kykenevyytt�� kapeiden muotojen sek�� ter��vien kulmien valmistuksessa. Tarkkuuteen sek�� kykenevyyteen vaikuttavia tekij��it�� selvitet����n aimmissa tutkimuksissa havaittujen seikkojen pohjalta, sek�� menetelm��n ominaisuuksien perusteella. Selvityksen pohjalta valmistetaan koekappaleet, jotka koettelevat valmistuslaitteiston kykenevyytt��. Lopuksi suoritetaan vertailu teoreettisten sek�� k��yt��nn��n haasteiden v��lill��.

Porous Bodies, Porous Minds. Emotions and the Supernatural in the ��slendingas��gur (ca. 1200���1400)

In my PhD Thesis, I study the conceptions and representation of emotions in medieval 13th and 14th-century Iceland. I have used Icelandic saga literature as my source material and Icelandic Family sagas (��slendingas��gur) as my main sources. Firstly, I wished to explore in my study the medieval Icelandic folk theory of emotions: what emotions were thought to be, from what they originated and how they operated? Secondly, in earlier research it has been shown that emotions were seldom described in ��slendingas��gur. They were mostly represented in dialogue, poetry or in somatic changes (e.g. turning pale). Consequently, I examined whether medieval Icelanders had alternative emotion discourses in literature, in addition to the usual manner of representation. My study consists of qualitative case studies, and I have analysed the sources intertextually. I suggest that medieval Icelanders regarded emotions as movements of the mind. The mind existed in the heart. As a consequence, emotions were considered physical in nature. The human body and therefore also the human mind was considered porous: if the mind of the person was not strong enough, supernatural agents and forces could penetrate theboundaries of his/her body as winds or sharp projectiles. Correspondingly, minds of strong-willed people could penetrate the minds of others. As a result, illness and emotions could upspring. People did not always distinguish between emotions and physical illnesses. Excessive emotions could cause illness, even death. Especially fear, grief and emotions of moral responsibility (e.g. guilt) made people vulnerable to the supernatural influence. Guilt was considered part of the emotional experience of misfortune (��g��fa), and in literature guilt could also be represented as eye pain that was inflicted upon the sufferer by a supernatural agent in a dream. Consequently, supernatural forces and beings were part of the upspring of emotions, but also part of the representation of emotions in literature: They caused the emotion but their presence also represented the emotional turmoil in the lives of the people that the supernatural agents harassed; emotions that had followed from norm transgressions, betrayal and other forms of social disequilibrium. Medieval readers and listeners of the ��slendingas��gur were used to interpreting such different layers of meaning in texts.