On the Properties and Cosmology of Q-balls

The properties and cosmological importance of a class of non-topological solitons, Q-balls, are studied. Aspects of Q-ball solutions and Q-ball cosmology discussed in the literature are reviewed. Q-balls are particularly considered in the Minimal Supersymmetric Standard Model with supersymmetry broken by a hidden sector mechanism mediated by either gravity or gauge interactions. Q-ball profiles, charge-energy relations and evaporation rates for realistic Q-ball profiles are calculated for general polynomial potentials and for the gravity mediated scenario. In all of the cases, the evaporation rates are found to increase with decreasing charge. Q-ball collisions are studied by numerical means in the two supersymmetry breaking scenarios. It is noted that the collision processes can be divided into three types: fusion, charge transfer and elastic scattering. Cross-sections are calculated for the different types of processes in the different scenarios. The formation of Q-balls from the fragmentation of the Aflieck-Dine -condensate is studied by numerical and analytical means. The charge distribution is found to depend strongly on the initial energy-charge ratio of the condensate. The final state is typically noted to consist of Q- and anti-Q-balls in a state of maximum entropy. By studying the relaxation of excited Q-balls the rate at which excess energy can be emitted is calculated in the gravity mediated scenario. The Q-ball is also found to withstand excess energy well without significant charge loss. The possible cosmological consequences of these Q-ball properties are discussed.

Q-metodologia politiikan tutkimuksessa: esimerkkin�� EU:n pohjoisen ulottuvuuden asiantuntijakeskustelu

Abstract: Q methodology in political science: expert debate on the EU's Northern dimension as an example

Iter S. Francisci Xaverii Ex Europa in Indi��, & Iaponiam - 1

Viduae 1703

Iter S. Francisci Xaverii Ex Europa in Indi��, & Iaponiam - 3

Viduae 1703

Iter S. Francisci Xaverii Ex Europa in Indi��, & Iaponiam - 2

Viduae 1703

Evaluation of GPRS Radio Link Control Layer in Weak RF Field

General Packet Radio Service (GPRS) mahdollistaa pakettimuotoisen tiedonsiirron GSM-verkossa. Se tarjoaa yhteyden pakettidataverkkoihin, nostaen samalla tiedonsiirtonopeutta radiorajapinnassa. Radioresurssit ovat varattuna vain silloin kun on jotain l��hetett��v����, tehden t��ten radioresurssien k��yt��n paljon tehokkaammaksi. T��m�� diplomity�� keskittyy GPRS protokollaan ja erityisesti sen datapinossa olevaan Radio Link Control (RLC) kerrokseen. RLC-kerros huolehtii GPRS- puhelimen ja tukiaseman v��lisen yhteyden luotettavuudesta. Ty��n tavoitteena on tutkia RLC-kerroksen toiminnallisuutta ja sen luotettavuutta heikossa kent��ss��, sek�� selvitt���� heikon kent��n vaikutusta uudelleenl��hetyksiin. Ty��n tuloksena saadaan arvio signaalin voimakkuuden sek�� uudelleen l��hetysten vaikutuksesta GPRS:n datansiirtonopeuteen. T��m�� ty�� k��sittelee my��s lyhyesti GSM-j��rjestelm����, koska lukijan on n��in helpompaa ymm��rt���� my��s GPRS-j��rjestelm��n vaatimia teknisi�� muutoksia. T��m�� diplomity�� on tehty osana Nokia Matkapuhelimet Oyj:ss�� k��ynniss�� olevaa GPRS tuotekehitysprojektia. Ty��n tuloksia k��ytet����n testauksen tukena ja niit�� on k��ytetty apuna RLC-kerroksen luotettavuustestauksen suunnittelussa.

RF Field Immunity of a Network Terminating Unit at Over One Gigaherz Frequencies

Ty��ss�� tutkitaan telep����telaitteen yli gigahertsin taajuisen s��teilev��n RF kent��n sietoisuutta. Mittauksissa testattava laite on Tellabs Oy:n valmistaman CTU modeemin tuotekehitysversio. Teoriaosassa k��yd����n l��pi s��hk��magneettisten aaltojen teoriaa, sek�� s��teilev��n RF kent��n aiheuttamien s��hk��magneettiset h��iri��iden syntymekanismeja. My��s s��teilevien h��iri��iden EMC mittauksiin tarvittavien mittalaitteiden t��rkeimm��t ominaisuudet esitell����n, sek�� pohditaan yli gigahertsin taajuuksille sopivien EMC mittalaitteiden vaatimuksia. EMC standardit eiv��t t��ll�� hetkell�� aseta vaatimuksia telelaitteiden RF kent��n sietoisuudelle yli gigahertsin taajuudella. T��m��n vuoksi ty��ss�� k��sitell����n my��s todenn��k��isimpi�� h��iri��l��hteit�� t��ll�� taajuusalueella. Mittauksissa tutkittiin CTU:n RF kent��n sietoisuutta taajuusalueella l - 4.2 GHz. Mittaukset suoritettiin sek�� radiokaiuttomassa kammiossa ett�� GTEM solussa. My��s metallisten lis��suojien vaikutusta CTU:n kent��nsietoisuuteen tutkittiin GTEM solussa.

High Throughput Purification of Combinatorial Libraries by Preparative LC/MS

Viime vuosien nopea kehitys on kiihdytt��nyt uusien l����kkeiden kehitt��misprosessia. Kombinatorinen kemia on tehnyt mahdolliseksi syntetisoida suuria kokoelmia rakenteeltaan toisistaan poikkeavia molekyylej��, nk. kombinatorisia kirjastoja, biologista seulontaa varten. Siin�� molekyylien rakenteeseen liittyv�� aktiivisuus tutkitaan useilla erilaisilla biologisilla testeill�� mahdollisten "osumien" l��yt��miseksi, joista osasta saatetaan my��hemmin kehitt���� uusia l����keaineita. Jotta biologisten tutkimusten tulokset olisivat luotettavia, on syntetisoitujen komponenttien oltava mahdollisimman puhtaita. T��m��n vuoksi tarvitaan HTP-puhdistusta korkealaatuisten komponenttien ja luotettavan biologisen tiedon takaamiseksi. Jatkuvasti kasvavat tuotantovaatimukset ovat johtaneet n��iden puhdistustekniikoiden automatisointiin ja rinnakkaistamiseen. Preparatiivinen LC/MS soveltuu kombinatoristen kirjastojen nopeaan ja tehokkaaseen puhdistamiseen. Monet tekij��t, esimerkiksi erotuskolonnin ominaisuudet sek�� virtausgradientti, vaikuttavat preparatiivisen LC/MS puhdistusprosessin tehokkuuteen. N��m�� parametrit on optimoitava parhaan tuloksen saamiseksi. T��ss�� ty��ss�� tutkittiin em��ksisi�� komponentteja erilaisissa virtausolosuhteissa. Menetelm�� kombinatoristen kirjastojen puhtaustason m����ritt��miseksi LC/MS-puhdistuksen j��lkeen optimoitiin ja m����ritettiin puhtaus joillekin komponenteille eri kirjastoista ennen puhdistusta.

Sulfaattimassan D/Q(EOP)D-valkaisimon optimointi

Ty��ss�� tutkittiin sulfaattisellutehtaan ECF-valkaisimon toimintaan vaikuttavia tekij��it��. Tavoitteena oli selvitt���� tekij��iden vaikutus massan laatuominaisuuksiin, valkaisimon kemikaalikustannuksiin ja klooridioksidin kulutukseen. Ty��n kirjallisuusosassa on tarkasteltu nykyaikaisen sulfaattisellutehtaan eri prosesseja. Erityist�� huomiota on kiinnitetty sellun ECF-valkaisuun ja kyseisess�� valkaisussa k��ytett��viin kemikaaleihin. Lis��ksi on tarkasteltu TCF-valkaisua ja mahdollisuuksia sulkea sellutehtaan vesikiertoja. Kokeellisessa osassa selvitettiin Oy Mets��-Botnia Ab Joutsenon tehtaan kolmivaiheisen ECF-valkaisimon massan laatuominaisuuksiin, kustannuksiin ja klooridioksidin kulutukseen vaikuttavia tekij��it��. Tavoitteena oli vaikuttaa positiivisesti massan laatuominaisuuksiin valkaisun keinoin. Samalla pyrittiin minimoimaan valkaisusta aiheutuvia kemikaalikustannuksia ja v��hent��m����n klooridioksidin kulutusta. Ty��ss�� k��ytettiin Taguchi-menetelm����. Tehdyn tutkimuksen my��t�� saatiin runsaasti tietoa mihin eri ominaisuuksiin tutkitut tekij��t vaikuttivat. Metallien poistolla eli kelatoinnilla havaittiin olevan suuri merkitys hapettavan alkaliuuttovaiheen ja samalla koko valkaisimon toimintaan. Suurella kelatointiaineannoksella valkaisimon selektiivisyys ja tehokkuus paranivat. Muista tekij��ist�� happiannoksella havaittiin olevan vaikutusta vain massan paperiteknisiin ominaisuuksiin ja hiilihydraattien koostumukseen. Happiannoksen kasvattaminen paransi rep��isyindeksi�� ja v��hensi massan jauhatustarvetta yli valkaisimon. Kyseisiin ominaisuuksiin vaikuttivat my��s klooridioksidi ja sen toimintaolosuhteet. Kemikaalikustannuksiin vaikuttavista tekij��ist�� valkaisimon tulokapalla ja ensimm��isen klooridioksidivaiheen kemikaaliannoksella havaittiin olevan suuri merkitys. Samat tekij��t vaikuttivat my��s valkaisimon klooridioksidin kokonaiskulukseen.

Electrochemical Characterisation of Filter Media Properties and Their Exploitation in Enhanced Filtration

Streaming potential measurements for the surface charge characterisation of different filter media types and materials were used. The equipment was developed further so that measurements could be taken along the surfaces, and so that tubular membranes could also be measured. The streaming potential proved to be a very useful tool in the charge analysis of both clean and fouled filter media. Adsorption and fouling could be studied, as could flux, as functions of time. A module to determine the membrane potential was also constructed. The results collected from the experiments conducted with these devices were used in the study of the theory of streaming potential as an electrokinetic phenomenon. Several correction factors, which are derived to take into account the surface conductance and the electrokinetic flow in very narrow capillaries, were tested in practice. The surface materials were studied using FTIR and the results compared with those from the streaming potentials. FTIR analysis was also found to be a useful tool in the characterisation of filters, as well as in the fouling studies. Upon examination of the recorded spectra from different depths in a sample it was possible to determine the adsorption sites. The influence of an external electric field on the cross flow microflltration of a binary protein system was investigated using a membrane electroflltration apparatus. The results showed that a significant improvement could be achieved in membrane filtration by using the measured electrochemical properties to help adjust the process conditions.

Hybrid LC Filter for Power Electronic Drives: Theory and Implementation

Power electronic converter drives use, for the sake of high efficiency, pulse-width modulation that results in sequences of high-voltage high-frequency steep-edged pulses. Such a signal contains a set of high harmonics not required for control purposes. Harmonics cause reflections in the cable between the motor and the inverter leading to faster winding insulation ageing. Bearing failures and problems with electromagnetic compatibility may also result. Electrical du/dt filters provide an effective solution to problems caused by pulse-width modulation, thereby increasing the performance and service life of the electrical machines. It is shown that RLC filters effectively decrease the reflection phenomena in the cable. Improved (simple, but effective) solutions are found for both differential- and common-mode signals; these solutions use a galvanic connection between the RLC filter star point and the converter DC link. Foil chokes and film capacitors are among the most widely used components in high-power applications. In actual applications they can be placed in different parts of the cabinet. This fact complicates the arrangement of the cabinet and decreases the reliability of the system. In addition, the inductances of connection wires may prevent filtration at high frequencies. This thesis introduces a new hybrid LC filter that uses a natural capacitance between the turns of the foil choke based on integration of an auxiliary layer into it. The main idea of the hybrid LC filter results from the fact that both the foil choke and the film capacitors have the same roll structure. Moreover, the capacitance between the turns (���intra capacitance���) of the foil inductors is the reason for the deterioration of their properties at high frequencies. It is shown that the proposed filter has a natural cancellation of the intra capacitance. A hybrid LC filter may contain two or more foil layers isolated from each other and coiled on a core. The core material can be iron or even air as in the filter considered in this work. One of the foils, called the main foil, can be placed between the inverter and the motor cable. Other ones, called auxiliary foils, may be connected in star to create differential-mode noise paths, and then coupled to the DC link midpoint to guarantee a traveling path, especially for the common-mode currents. This way, there is a remarkable capacitance between the main foil and the auxiliary foil. Investigations showed that such a system can be described by a simple equivalent LC filter in a wide range of frequencies. Because of its simple hybrid construction, the proposed LC filter can be a cost-effective and competitive solution for modern power drives. In the thesis, the application field of the proposed filter is considered and determined. The basics of hybrid LC filter design are developed further. High-frequency behaviour of the proposed filter is analysed by simulations. Finally, the thesis presents experimental data proving that the hybrid LC filter can be used for du/dt of PWM pulses and reduction of common-mode currents.

Pienitaajuinen radiosekoitin

Normaalisti radiovastaanottimet on luokiteltavissa suoriin vastaanottimiin ja superheterodynevastaanottimiin. J��lkimm��ist�� nimitet����n tavallisesti supervastaanottimeksi. Molemman vastaanottimen oleellisiin osiin kuuluu antennin virityspiiri, supervastaanottimelle lis��ksi paikallisoskillaattorin virityspiiri, mik�� pit���� viritt���� antennipiirin kanssa samanaikaisesti. Pienill�� taajuuksilla, taajuudet luokassa kilo-Hertzej�� tai pienemmill��, on antennipiirin viritys resonanssipiirin ominaisuuksista johtuen sit�� kapeammalla kaistalla ja sit�� hitaampaa mit�� pienemm��ll�� taajuudella vastaanotto tapahtuu. Lis��ksi virityspiiri hyvyysluku Q on vaikea saada sopivaksi, mik��li viritys on muuten k��yt��nn��llinen, s����dett��v�� resonanssipiiri. Vaadittaessa kiinte��taajuista virityst�� on k��yt��nn��llist�� hy��dynt���� s��hk��mekaanisia osia, siis keraamisia tai kvartsikiteit��. Koska kiteitten ja korkean hyvyysluvun piirin v��r��htely jatkuu useita v��r��htelyjaksoja ennen saapuneitten v��r��htelyjen sammumista, kest���� my��s kauan aikaa, ennen kuin v��r��htely piiriss�� on loppu. Pienitaajuinen resonanssipiiri saavuttaa maksimivirtansa hitaasti, jos hyvyysluku on iso, kun piiri alkaa johtaa resonanssitaajuista virtaa. T��ss�� ty��ss�� pyrit����n vastaanotinj��rjestelyyn ongelmallisen, pientaajuisen virityspiirin k��yt��n v��ltt��miseksi. Toisena tavoitteena on saada aikaan vastaanotto siten, ett�� tietty pienitaajuinen radiotaajuusalue voidaan kokonaisuudessaan vastaanottaa jatkuva-aikaisesti, ilman antennipiirin jatkuvaa viritt��mist�� erillisille taajuuksille. Laaditaan kytkent��, joka mitoitetaan, simuloidaan ja mitataan.

Novel Robot Solutions for Carrying out Field Joint Welding and Machining in the Assembly of the Vacuum Vessel of ITER

It is necessary to use highly specialized robots in ITER (International Thermonuclear Experimental Reactor) both in the manufacturing and maintenance of the reactor due to a demanding environment. The sectors of the ITER vacuum vessel (VV) require more stringent tolerances than normally expected for the size of the structure involved. VV consists of nine sectors that are to be welded together. The vacuum vessel has a toroidal chamber structure. The task of the designed robot is to carry the welding apparatus along a path with a stringent tolerance during the assembly operation. In addition to the initial vacuum vessel assembly, after a limited running period, sectors need to be replaced for repair. Mechanisms with closed-loop kinematic chains are used in the design of robots in this work. One version is a purely parallel manipulator and another is a hybrid manipulator where the parallel and serial structures are combined. Traditional industrial robots that generally have the links actuated in series are inherently not very rigid and have poor dynamic performance in high speed and high dynamic loading conditions. Compared with open chain manipulators, parallel manipulators have high stiffness, high accuracy and a high force/torque capacity in a reduced workspace. Parallel manipulators have a mechanical architecture where all of the links are connected to the base and to the end-effector of the robot. The purpose of this thesis is to develop special parallel robots for the assembly, machining and repairing of the VV of the ITER. The process of the assembly and machining of the vacuum vessel needs a special robot. By studying the structure of the vacuum vessel, two novel parallel robots were designed and built; they have six and ten degrees of freedom driven by hydraulic cylinders and electrical servo motors. Kinematic models for the proposed robots were defined and two prototypes built. Experiments for machine cutting and laser welding with the 6-DOF robot were carried out. It was demonstrated that the parallel robots are capable of holding all necessary machining tools and welding end-effectors in all positions accurately and stably inside the vacuum vessel sector. The kinematic models appeared to be complex especially in the case of the 10-DOF robot because of its redundant structure. Multibody dynamics simulations were carried out, ensuring sufficient stiffness during the robot motion. The entire design and testing processes of the robots appeared to be complex tasks due to the high specialization of the manufacturing technology needed in the ITER reactor, while the results demonstrate the applicability of the proposed solutions quite well. The results offer not only devices but also a methodology for the assembly and repair of ITER by means of parallel robots.