Kuumailmapolttolaitteiston numeerinen virtausmallinnus

Tämä diplomityö perustuu Lappeenrannan teknillisen yliopiston Uusiutuvien energiajärjestelmien laboratorion koelaitteistoon, jolla tutkitaan voimakkaan savukaasunkierrätyksen ja kuumailmapolton soveltuvuutta pienen kokoluokan energiantuotantoprosesseihin. Työn teoriaosassa esitellään tavanomaisesta palamisesta eroavaa kuumailmapolttoa ja tarkastellaan sen ominaisuuksia. Myös työssä käytetyn tutkimusmenetelmän, numeerisen virtauslaskennan, periaatteita ja ominaisuuksia tarkastellaan. Työssä tutkitaan numeerisella virtausmallinnuksella kuumailmapolttolaitteiston virtauskentän käyttäytymistä, kun takaisin tulipesään kierrätettävän savukaasun määrä sekä tulipesän lämpöhäviöiden suuruus vaihtelevat. Virtauskentän tarkastelu on tärkeää, sillä palamisilman ja kierrätetyn savukaasun täytyy sekoittua kuumailmapolton aikaansaamiseksi. Työn virtausmallinnus suoritettiin Finflo-virtausratkaisijalla kaksiulotteisena palamisreaktioita mallintamatta. Vaikka työssä käytetyt mallit olivat kaksiulotteisia ja niissä käytettiin yksinkertaistuksia, virtausten käyttäytymisestä tulipesässä saatiin olennaista tietoa, jota voidaan mahdollisesti hyödyntää jatkotutkimuksissa.

Usability of laser–arc hybrid welding processes in industrial applications

Metal industries producing thick sections have shown increasing interest in the laser–arc hybrid welding process because of its clear advantages compared with the individual processes of autogenous laser welding and arc welding. One major benefit of laser–arc hybrid welding is that joints with larger gaps can be welded with acceptable quality compared to autogenous laser welding. The laser-arc hybrid welding process has good potential to extend the field of applications of laser technology, and provide significant improvements in weld quality and process efficiency in manufacturing applications. The objective of this research is to present a parameter set-up for laser–arc hybrid welding processes, introduce a methodical comparison of the chosen parameters, and discuss how this technology may be adopted in industrial applications. The research describes the principles, means and applications of different types of laser–arc hybrid welding processes. Conducted experiment processing variables are presented and compared using an analytical model which can also be used for predictive simulations. The main argument in this thesis is that profound understanding of the advanced technology of laser-arc hybrid welding will help improve the productivity of welding in industrial applications. Based on a review of the current knowledge base, important areas for further research are also identified. This thesis consists of two parts. The first part introduces the research topic and discusses laser–arc hybrid welding by characterizing its mechanism and most important variables. The second part comprises four research papers elaborating on the performance of laser– arc hybrid welding in the joining of metals. The study uses quantitative and qualitative research methods which include in-depth, interpretive analyses of results from a number of research groups. In the interpretive analysis, the emphasis is placed on the relevance and usefulness of the investigative results drawn from other research publications. The results of this study contribute to research on laser–arc hybrid welding by increasing understanding of how old and new perspectives on laser–arc hybrid welding are evidenced in industry. The research methodology applied permits continued exploration of how laser–arc hybrid welding and various process factors influence the overall quality of the weld. Thestudy provides a good foundation for future research, creates improved awareness of the laser–arc hybrid welding process, and assists the metal industry to maximize welding productivity.

Kiinteistön elinkaarihankkeen rahoitus ja riskit

Julkisen sektorin kiinteistötuotannossa toteutetaan kasvavassa määrin julkisen ja yksityisen sektorin yhteistyötä, jossa yksityinen yritys ottaa vastuun kiinteistöön liittyvistä suunnittelu-, rakentamis- ja ylläpitotoimista pitkäksi ajanjaksoksi. Työn tavoitteena on arvioida elinkaarimallilla toteuttavien kiinteistöhankkeiden toteutusvaihtoehdot, sekä kartoittaa elinkaarihankkeen sisältämiä riskejä hankkeen suunnitteluvaiheessa. Tutkimus suoritetaan kvalitatiivisena tutkimuksena, jota tuetaan tarvittavilla kvantitatiivista tietoa hyödyntävillä laskelmilla. Tutkimusaineistona käytetään aihepiiriin liittyviä akateemisia julkaisuja ja oppikirjoja. Työn toimeksiantajan YIT:n kautta tutkimukseen on saatu arvokasta asiantuntemusta ja materiaalia. Elinkaarihankkeiden hankintamenettelyksi suositellaan kilpailullista neuvottelumenettelyä. Kilpailullinen neuvottelumenettely mahdollistaa tilaajan ja palveluntuottajien välisen dialogin hankintamenettelyn aikana, jolloin osapuolet voivat yhteistyössä valita sopivimman toteutusmallin. Hankkeiden rahoitus voidaan toteuttaa tilaajan rahoituksella tai yksityisrahoituksella. Rahoituksen näkökulmasta tilaajan oma rahoitus on edullisin, mikä ei kuitenkaan vähennä elinkaarimallista saatavia etuja perinteiseen urakointiin verrattuna. Laskelman perusteella tilaajan rahoituksen ja yksityisrahoituksen keskimääräisessä korkotasossa (WACC) on eroa 2,8 %. Projektiyhtiön perustaminen tekee rahoituksesta entistä kalliimpaa, koska taseeseen kohdistuviin kustannuksiin lisätään projektiyhtiön oman pääoman tuottovaatimusta vastaava korko. Palveluntuottajan kannalta olennaiset riskit ovat rakennusvaiheen viivästyminen, kiinteistön käytettävyyden ja soveltuvuuden puutteista aiheutuvat muutostyöt. Palvelumaksun sitominen huonosti ylläpidon todellista kulurakennetta kuvaavaan elinkustannusindeksiin tulee pitkällä sopimuskaudella vähentämään palveluntuottajan toiminnan kannattavuutta. Kiinteistön ylläpidon kustannusindeksi on vuosina 2005–2011 noussut 2,3 % nopeammin vuodessa kuin elinkustannusindeksi.

Novel force control methods in a teleoperation system of a hydraulic slider

The objective of the this research project is to develop a novel force control scheme for the teleoperation of a hydraulically driven manipulator, and to implement an ideal transparent mapping between human and machine interaction, and machine and task environment interaction. This master‘s thesis provides a preparatory study for the present research project. The research is limited into a single degree of freedom hydraulic slider with 6-DOF Phantom haptic device. The key contribution of the thesis is to set up the experimental rig including electromechanical haptic device, hydraulic servo and 6-DOF force sensor. The slider is firstly tested as a position servo by using previously developed intelligent switching control algorithm. Subsequently the teleoperated system is set up and the preliminary experiments are carried out. In addition to development of the single DOF experimental set up, methods such as passivity control in teleoperation are reviewed. The thesis also contains review of modeling of the servo slider in particular reference to the servo valve. Markov Chain Monte Carlo method is utilized in developing the robustness of the model in presence of noise.

Does the edge effect influence plant community structure in a tropical dry forest?

Edge effects are considered a key factor in regulating the structure of plant communities in different ecosystems. However, regardless to few studies, edge influence does not seem to be decisive in semiarid regions such as the Brazilian tropical dry forest known as Caatinga but this issue remains inconclusive. The present study tests the null hypothesis that the plant community of shrubs and trees does not change in its structure due to edge effects. Twenty-four plots (20 x 20 m) were set up in a fragment of Caatinga, in which 12 plots were in the forest edges and 12 plots were inside the fragment. Tree richness, abundance and species composition did not differ between edge and interior plots. The results of this study are in agreement with the pattern previously found for semiarid environments and contrasts with previous results obtained in different environments such as Rainforests, Savanna and Forest of Araucaria, which indicate abrupt differences between the border and interior of the plant communities in these ecosystems, and suggest that the community of woody plants of the Caatinga is not ecologically affected by the presence of edges.

Sewage Sludge Electro-Dewatering

Original sludge from wastewater treatment plants (WWTPs) usually has a poor dewaterability. Conventionally, mechanical dewatering methods are used to increase the dry solids (DS) content of the sludge. However, sludge dewatering is an important economic factor in the operation of WWTPs, high water content in the final sludge cake is commonly related to an increase in transport and disposal costs. Electro‐dewatering could be a potential technique to reduce the water content of the final sludge cake, but the parameters affecting the performance of electro‐dewatering and the quality of the resulting sludge cake, as well as removed water, are not sufficiently well known. In this research, non‐pressure and pressure‐driven experiments were set up to investigate the effect of various parameters and experimental strategies on electro‐dewatering. Migration behaviour of organic compounds and metals was also studied. Application of electrical field significantly improved the dewatering performance in comparison to experiments without electric field. Electro‐dewatering increased the DS content of the sludge from 15% to 40 % in non‐pressure applications and from 8% to 41% in pressure‐driven applications. DS contents were significantly higher than typically obtained with mechanical dewatering techniques in wastewater treatment plant. The better performance of the pressure‐driven dewatering was associated to a higher current density at the beginning and higher electric field strength later on in the experiments. The applied voltage was one of the major parameters affecting dewatering time, water removal rate and DS content of the sludge cake. By decreasing the sludge loading rate, higher electrical field strength was established between the electrodes, which has a positive effect on an increase in DS content of the final sludge cake. However interrupted voltage application had anegative impact on dewatering in this study, probably because the off‐times were too long. Other factors affecting dewatering performance were associated to the original sludge characteristics and sludge conditioning. Anaerobic digestion of the sludge with high pH buffering capacity, polymer addition and freeze/thaw conditioning had a positive impact on dewatering. The impact of pH on electro‐dewatering was related to the surface charge of the particles measured as zeta‐potential. One of the differences between electro‐dewatering and mechanical dewatering technologies is that electro‐dewatering actively removes ionic compounds from the sludge. In this study, dissolution and migration of organic compounds (such as shortchain fatty acids), macro metals (Na, K, Ca, Mg, Fe) and trace metals (Ni, Mn, Zn, Cr) was investigated. The migration of the metals depended on the fractionation and electrical field strength. These compounds may have both negative and positive impacts on the reuse and recycling of the sludge and removed water. Based on the experimental results of this study, electro‐dewatering process can be optimized in terms of dewatering time, desired DS content, power consumption and chemical usage.

Venäläistä rulettia – Nuorten perhesuunnittelun esteet ja tarpeet Pietarissa ja Riiassa

Latviassa ja Venäjällä heikko demografinen tilanne on lisännyt keskustelua seksuaali- ja kansalaisoikeuksista sekä valtion merkityksestä niiden toteuttamisessa. Väestöpolitiikassa näkyy yhteiskunnallinen tilanne sekä sen kyky ja mahdollisuudet huomioida nuorten perhesuunnitteluun liittyviä tarpeita. Huomion kohteena on myös palvelujärjestelmä ja siinä toteutuva yksilöllinen taso. Tutkin perhesuunnittelua kokonaisvaltaisesti, mikä ilmenee erilaisten polkuriippuvuuksien tarkasteluina. Mielenkiintoiseksi kohteen tekee entisten sosialististen valtioiden erityislaatuisen murroksen läpikäyminen. Perhesuunnittelu on osa seksuaali- ja ihmisoikeuksia. Siihen kuuluu seksuaaliterveydestä tiedottaminen ja ohjaus sekä siihen liittyvät toimenpiteet. Perhesuunnittelu sisältää niin sosiaaliset, kasvatukselliset kuin lääketieteellisetkin näkökulmat. Siihen liitetään myös moraalisia ja taloudellisia näkemyksiä, sekä politiikkaa ja henkilökohtaisuutta. Tutkimustehtäväni on nuorten perhesuunnittelun esteet ja tarpeet Riiassa ja Pietarissa. Sovellan metodologisena lähestymistapana sosiaalihistoriallista ja etnografista tutkimusotetta, jolloin perinteen vaikutusten, kulttuuristen rakenteiden ja yksilöllisten toimintatapojen ymmärtäminen mahdollistuu. Aineisto koostuu viranomaishaastatteluista sosialismin kaudella toteutuneesta sekä nykyisestä perhesuunnittelusta ja nuorten haastatteluista Pietarissa ja Riiassa. Perehdyn myös lisääntymisterveyteen liittyviin sanomalehtiartikkeleihin sekä Latviassa että Venäjällä. Lisäksi havainnoin seksuaalineuvontatilanteita Pietarissa. Sekä sosialismin aikana että nykyään painottuvat väestönkasvun odotukset, joita tuetaan sukupuoli- ja moraalikasvatuksen avulla. Perhesuunnittelun esteiden analyysin tuloksissa on nähtävissä sosiaalisten olosuhteiden ja rakenteiden merkitys. Jälkisosialistisesta riskiyhteiskunnasta puuttuvat yhteiskuntaan integroitumisen mahdollistavat instituutiot. Tämä ilmenee yhteiskunnallisena vastuuttomuutena. Universaalit palvelut ovat suurelta osin peräisin sosialismin ajalta. Kaupalliset yritykset tekevät lähinnä teknisiä, yksittäisiä ehkäisyvälineisiin liittyviä interventioita nuorten elämään. Teini-ikäiset jätetään oman harkintansa varaan. Latviassa perhesuunnitteluun liittyvä ennalta ehkäisevä toiminta on huomioitu uudessa lisääntymisterveyslaissa, mutta sen heikko toteutus tuo sen lähelle neuvostoaikaista kulttuurikonventiota, jossa määrällisillä suoritteilla ja sekundaaripreventiolla on arvoa. Venäjällä voimavarat kohdentuvat jälkihuollon palveluihin. Foucaultin valta-analyysi kertoo strategiasta, jossa ihminen sisäistää vallankäytön osaksi omaa ajatteluaan ja toimintaansa. Tässä näkökulmassa yksilöllinen, yhteiskunnallinen ja historiallinen ulottuvuus limittyvät toisiinsa. Vallan muodot ovat yhteiskunnan rakenteissa. Väestöpolitiikan avulla tuotetaan tietoa ja muovataan hallitsemisen kohteita. Osa haastatelluista nuorista omaksui yhteiskunnan passiivisuuden osaksi omaa toimintaansa. He eivät tiedostaneet palvelujärjestelmän puutteita eivätkä kyseenalaistaneet sen oikeutusta. Myös lehtiartikkelit ja viranomaishaastattelut tukivat osittain seksuaalikasvatuksen sivuuttamista. Silloin hyväksyttävänä totuutena pidettiin väestöpolitiikkaa, jossa on annettu tilaa populistisille suuntauksille. Sekä Latviassa että Venäjällä ilmaistiin tavoitteita väestön kasvusta. Kansainvälisten seksuaalioikeuksien maihinnousu ei ole poistanut ääri uskonnollisten ja osittain kansalaisjärjestöjen puitteissa tapahtuvaa perhesuunnittelun vastustusta. Näissä suuntauksissa vaikutetaan ihmisten moraaliin ja vastustetaan yhteiskunnan interventioita kieltämällä seksuaalikasvatus. Sosialismin aikana sosiaali- ja terveydenhuoltoa toteutettiin totalitaristisessa, suljetussa yhteiskunnassa tiukasti rajatuilla voimavaroilla. Tuolta ajalta peräisin oleva viranomaisten yleinen medikalisoitunut ja tekninen lähestymistapa estää osittain nuoren valtaistumista. Vieläkin heikko tiedottaminen ja puutteellinen koulutus vaikuttavat ammattilaisten keskuudessa. Yksi haitallisista perhesuunnitteluun kuuluvista uskomuksista oli hormonaalisen ehkäisyn aiheuttamat ongelmat. Lisäksi pelättiin heikkotasoisesti tehtyjen aborttien aiheuttavan hedelmättömyyttä. Uskomukset ovat eläneet vieläkin, kun osa asiantuntijoista kannusti ensimmäisen raskauden päättymistä synnytykseen. Näillä käsityksillä on ollut taipumus siirtyä sukupolvelta toiselle myös kansalaisten keskuudessa. Sukuyhteisöjen ja verkostojen oleellinen merkitys teini-ikäisen arjessa ja selviytymisessä painotti perinteistä sosialisaatiota. Uskomusten lisäksi nuorten heikko taloudellinen tilanne on ohjannut heitä ehkäisyssä luonnonmenetelmien käyttöön. Neuvostoaikainen seksuaalikielteisyyden perinne on vaikuttanut myös sukupolvien kyvyttömyyteen keskustella aiheesta. Yleisen ennaltaehkäisevän neuvonnan puuttuminen on suunnannut suurta osaa nuoria mallioppimiseen, jossa esimerkit ovat nousseet satunnaisista löydöistä. Toisaalta työntekijöiden neuvokkuus ja aloitteellisuus erilaisissa ohjaamistilanteissa, toimintatavoissa ja instituutioiden perustamisissa kuvaavat eettistä vastuunottoa ja paneutumista nuorten perhesuunnittelun toteutumiseen sekä sen mahdollisuuksiin. Perhesuunnitteluun liittyvän tiedonsaannin parantamiseksi viranomaiset ovat aloittaneet nuorten vertaisryhmiä. Lisäksi yhtenä uutena virallisena lähestymistapana oli neuvostoaikana kielletty psykoterapeuttisen suuntauksen avoin käyttöönotto. Myös nuorille suunnattuja palveluja niin lainsäädännön kuin instituutioiden tasolla on saatu aikaan. Nämä myönteiset tapaukset jäivät kuitenkin yksittäisiksi, osittain joidenkin työntekijöiden omakohtaisen sitoutumisen varaan toimiviksi. Tutkimuksessa nousee esiin yhteiskunnan vastuu erityisesti haavoittuvien ryhmien kohdalla. Nuoret ovat tiedoiltaan ja kokemuksiltaan heikossa asemassa. Sosiaalipoliittisesta näkökulmasta julkisilla ja ennaltaehkäisevillä palveluilla on keskeinen merkitys etenkin niiden kohdalla, jotka tarvitsevat runsaasti palveluja. Usein tähän ryhmään kuuluvat ovat passiivisia tiedon hakijoita. Tutkimus tuo esille perhesuunnittelun palvelujärjestelmään ja sen kohderyhmään kuuluvan moniulotteisuuden, jossa toisiinsa nivoutuvat kulttuuriset myytit, uskomukset, tabut, toimintatavat ja tietämys. Näiden polkujen avaaminen tässä tutkimuksessa edistää perhesuunnittelun esteiden tunnistamista ja niihin soveltuvien ratkaisukeinojen löytymistä.

Systems of aerial spraying for soybean rust control

The soybean rust caused by Phakopsora pachyrhizi is considered the main soybean disease and consequently the appropriate selection and the use of spraying equipment are vital for its control. The aim of this study was to evaluate the performance of aerial application equipment for soybean rust control. It was used: Micronair AU 5000 at 10 L ha-1 (with oil) and at 20 L ha-1 (without oil); Stol ARD atomizer at 10 and 20 L ha-1 (both with oil) and Spectrum (electrostatic) at 10 L ha-1 (without oil). The adjuvant was cotton oil (1.0 L ha-1) with emulsifier (BR 455) at 0.025 L ha-1. The field trial was set up at the 3rd fungicide application, when f four replications of each treatment. There were no statistical differences among treatments related to fungicide deposits by at a Confidence Interval of 95%. It was observed that the best results were obtained with Micronair (10 L ha-1 with oil), Stol (20 L ha-1 with oil) and electrostatic system at 10 L ha-1 with the lowest relative humidity (64%).

Root system distribution of sugarcane irrigated with domestic sewage effluent aplication by subsurface drip system

Irrigation with domestic sewage effluent (DSE) has been recommended by subsurface dripping, as it can obtain a high rate of irrigation efficiency and faster use of salts in comparison with other irrigation methods. The study aimed at evaluating the area, the length and the effective depth of the root system of sugarcane irrigated with DSE by subsurface drip system and with different irrigation rates at depths of 0.00-0.20, 0.20-0.40, 0.40-0.60 and 0.60-0.80m. The experiment was carried out in the municipality of Piracicaba, in the state of São Paulo (SP), Brazil, in a sugarcane area irrigated with DSE in a completely randomized blocks set up in furrows, with three replications and four treatments, which are: one area without irrigation (AWI) and three irrigated areas meeting 50% (T50%), 100% (T100%) and 200% (T200%) of the crop's water need between each round of irrigation. T100% and T200% provided smaller areas and lengths of roots in the two deepest layers, as compared to AWI and T50%, which stimulated the development of deeper roots due to the water stress. TWI, T100% and T200% presented 80% of the roots up to a depth of 0.40m and T50% treatment presented 76.43% of roots total.

Application of artificial neural networks as an alternative to volumetric water balance in drip irrigation management in watermelon crop

Precision irrigation seeks to establish strategies which achieve an efficient ratio between the volume of water used (reduction in input) and the productivity obtained (increase in production). There are several studies in the literature on strategies for achieving this efficiency, such as those dealing with the method of volumetric water balance (VWB). However, it is also of great practical and economic interest to set up versatile implementations of irrigation strategies that: (i) maintain the performance obtained with other implementations, (ii) rely on few computational resources, (iii) adapt well to field conditions, and (iv) allow easy modification of the irrigation strategy. In this study, such characteristics are achieved when using an Artificial Neural Network (ANN) to determine the period of irrigation for a watermelon crop in the Irrigation Perimeter of the Lower Acaraú, in the state of Ceará, Brazil. The Volumetric Water Balance was taken as the standard for comparing the management carried out with the proposed implementation of ANN. The statistical analysis demonstrates the effectiveness of the proposed management, which is able to replace VWB as a strategy in automation.

Tuotannonohjausmuodon vaihtaminen tilausohjautuvasta varasto-ohjautuvaan

Diplomityössä tutkitaan tuotannonohjausmuodon vaihtamista tilausohjautuvasta varasto-ohjautuvaan. Tavoitteena on löytää kohdeyritykselle kustannustehokkain vaihtoehto tuotannonohjaukseen. Tutkimuksessa analysoidaan yrityksen tuotantoprosessi nykytila-analyysilla toiminnan tehokkuuden arvioimiseksi ja tuotannon pullonkaulojen löytämiseksi. Asiakastilauksen kytkentäpisteet ja taloudelliset tuotantoeräkoot määritellään yrityksen valmistamille tuotteille. Työn tuloksissa käydään tuotannon tunnuslukujen avulla läpi tuotannon tehokkuuden kehittymistä projektin aikana. Varasto-ohjautuva tuotannonohjausmuoto osoittautui kannattavimmaksi ohjausmuodoksi tarkasteltavana ajankohtana. Toimitusvarmuus ja kapasiteetin käyttöaste parantuivat ohjausmuodon vaihtamisen myötä. Asetuskustannuksia saatiin vähennettyä ja tuotantoprosessia kehitettyä. Tuotannon läpimenoaikojen lyhennyttyä tilausohjautuvuutta tulee tarkastella uudestaan.

Identification and characterisation of a novel adhesin of Streptococcus suis and its use as a target of adhesion inhibition and bacterial detection

Streptococcus suis is an important pig pathogen but it is also zoonotic, i.e. capable of causing diseases in humans. Human S. suis infections are quite uncommon but potentially life-threatening and the pathogen is an emerging public health concern. This Gram-positive bacterium possesses a galabiose-specific (Galalpha1−4Gal) adhesion activity, which has been studied for over 20 years. P-fimbriated Escherichia coli−bacteria also possess a similar adhesin activity targeting the same disaccharide. The galabiose-specific adhesin of S. suis was identified by an affinity proteomics method. No function of the protein identified was formerly known and it was designated streptococcal adhesin P (SadP). The peptide sequence of SadP contains an LPXTG-motif and the protein was proven to be cell wall−anchored. SadP may be multimeric since in SDS-PAGE gel it formed a protein ladder starting from about 200 kDa. The identification was confirmed by producing knockout strains lacking functional adhesin, which had lost their ability to bind to galabiose. The adhesin gene was cloned in a bacterial expression host and properties of the recombinant adhesin were studied. The galabiose-binding properties of the recombinant protein were found to be consistent with previous results obtained studying whole bacterial cells. A live-bacteria application of surface plasmon resonance was set up, and various carbohydrate inhibitors of the galabiose-specific adhesins were studied with this assay. The potencies of the inhibitors were highly dependent on multivalency. Compared with P-fimbriated E. coli, lower concentrations of galabiose derivatives were needed to inhibit the adhesion of S. suis. Multivalent inhibitors of S. suis adhesion were found to be effective at low nanomolar concentrations. To specifically detect galabiose adhesin−expressing S. suis bacteria, a technique utilising magnetic glycoparticles and an ATP bioluminescence bacterial detection system was also developed. The identification and characterisation of the SadP adhesin give valuable information on the adhesion mechanisms of S. suis, and the results of this study may be helpful for the development of novel inhibitors and specific detection methods of this pathogen.

Four-arm single docking full robotic surgery for low rectal cancer: technique standardization

The authors present the four-arm single docking full robotic surgery to treat low rectal cancer. The eight main operative steps are: 1- patient positioning; 2- trocars set-up and robot docking; 3- sigmoid colon, left colon and splenic flexure mobilization (lateral-to-medial approach); 4-Inferior mesenteric artery and vein ligation (medial-to-lateral approach); 5- total mesorectum excision and preservation of hypogastric and pelvic autonomic nerves (sacral dissection, lateral dissection, pelvic dissection); 6- division of the rectum using an endo roticulator stapler for the laparoscopic performance of a double-stapled coloanal anastomosis (type I tumor); 7- intersphincteric resection, extraction of the specimen through the anus and lateral-to-end hand sewn coloanal anastomosis (type II tumor); 8- cylindric abdominoperineal resection, with transabdominal section of the levator muscles (type IV tumor). The techniques employed were safe and have presented low rates of complication and no mortality.

Two-Photon Excited Fluorescence Detection Technology in Screening for Methicillin-Resistant Staphylococcus aureus

Control of the world-wide spread of methicillin-resistant Staphylococcus aureus (MRSA) has been unsuccessful in most developed countries. A few countries have been able to maintain a low MRSA prevalence, plausibly due to their strict MRSA control policies. Such policies require wide-scale screening of patients with suspected MRSA colonization, in order to nurse the MRSA-positive patients in contact isolation. The aim of this study was to develop and introduce a 2-photon excited fluorescence detection (TPX) technique for screening of MRSA directly from clinical samples. The assay principle involves specific online immunometric monitoring of S. aureus growth under selective antibiotic pressure. After the novel TPX approach had been set up, its applicability for the detection of MRSA was evaluated using a large MRSA collection including practically all epidemic MRSA strains identified in Finland between 1991 and 2009. The TPX assay was found both sensitive (97.9%) and specific (94.1%) in this epidemiological setting, illustrating that the method is tolerant to wide biological variation as well as to environments with rapidly emerging MRSA strains. When MRSA was screened directly from colonization samples, all patients positive for MRSA by conventional methods were positive also by the TPX assay. The assay capacity was 48 samples per a test run, and the median time required for confirmation of a true-positive screening test result was 3 h 26 min. Collectively, the findings presented in this thesis suggest that the TPX MRSA screening assay could be applicable for direct screening of MRSA colonization samples without any prior steps of isolation. This can potentially mean that contact isolation of suspected carriers testing negative could be discontinued earlier, thereby reducing the costs and burden associated with the containment of MRSA. In case of infection, a positive test result would ensure an early onset of effective therapy.

Characterisation of Laser Beam and Paper Material Interaction

It is known already from 1970´s that laser beam is suitable for processing paper materials. In this thesis, term paper materials mean all wood-fibre based materials, like dried pulp, copy paper, newspaper, cardboard, corrugated board, tissue paper etc. Accordingly, laser processing in this thesis means all laser treatments resulting material removal, like cutting, partial cutting, marking, creasing, perforation etc. that can be used to process paper materials. Laser technology provides many advantages for processing of paper materials: non-contact method, freedom of processing geometry, reliable technology for non-stop production etc. Especially packaging industry is very promising area for laser processing applications. However, there are only few industrial laser processing applications worldwide even in beginning of 2010´s. One reason for small-scale use of lasers in paper material manufacturing is that there is a shortage of published research and scientific articles. Another problem, restraining the use of laser for processing of paper materials, is colouration of paper material i.e. the yellowish and/or greyish colour of cut edge appearing during cutting or after cutting. These are the main reasons for selecting the topic of this thesis to concern characterization of interaction of laser beam and paper materials. This study was carried out in Laboratory of Laser Processing at Lappeenranta University of Technology (Finland). Laser equipment used in this study was TRUMPF TLF 2700 carbon dioxide laser that produces a beam with wavelength of 10.6 μm with power range of 190-2500 W (laser power on work piece). Study of laser beam and paper material interaction was carried out by treating dried kraft pulp (grammage of 67 g m-2) with different laser power levels, focal plane postion settings and interaction times. Interaction between laser beam and dried kraft pulp was detected with different monitoring devices, i.e. spectrometer, pyrometer and active illumination imaging system. This way it was possible to create an input and output parameter diagram and to study the effects of input and output parameters in this thesis. When interaction phenomena are understood also process development can be carried out and even new innovations developed. Fulfilling the lack of information on interaction phenomena can assist in the way of lasers for wider use of technology in paper making and converting industry. It was concluded in this thesis that interaction of laser beam and paper material has two mechanisms that are dependent on focal plane position range. Assumed interaction mechanism B appears in range of average focal plane position of 3.4 mm and 2.4 mm and assumed interaction mechanism A in range of average focal plane position of 0.4 mm and -0.6 mm both in used experimental set up. Focal plane position 1.4 mm represents midzone of these two mechanisms. Holes during laser beam and paper material interaction are formed gradually: first small hole is formed to interaction area in the centre of laser beam cross-section and after that, as function of interaction time, hole expands, until interaction between laser beam and dried kraft pulp is ended. By the image analysis it can be seen that in beginning of laser beam and dried kraft pulp material interaction small holes off very good quality are formed. It is obvious that black colour and heat affected zone appear as function of interaction time. This reveals that there still are different interaction phases within interaction mechanisms A and B. These interaction phases appear as function of time and also as function of peak intensity of laser beam. Limit peak intensity is the value that divides interaction mechanism A and B from one-phase interaction into dual-phase interaction. So all peak intensity values under limit peak intensity belong to MAOM (interaction mechanism A one-phase mode) or to MBOM (interaction mechanism B onephase mode) and values over that belong to MADM (interaction mechanism A dual-phase mode) or to MBDM (interaction mechanism B dual-phase mode). Decomposition process of cellulose is evolution of hydrocarbons when temperature is between 380- 500°C. This means that long cellulose molecule is split into smaller volatile hydrocarbons in this temperature range. As temperature increases, decomposition process of cellulose molecule changes. In range of 700-900°C, cellulose molecule is mainly decomposed into H2 gas; this is why this range is called evolution of hydrogen. Interaction in this range starts (as in range of MAOM and MBOM), when a small good quality hole is formed. This is due to “direct evaporation” of pulp via decomposition process of evolution of hydrogen. And this can be seen can be seen in spectrometer as high intensity peak of yellow light (in range of 588-589 nm) which refers to temperature of ~1750ºC. Pyrometer does not detect this high intensity peak since it is not able to detect physical phase change from solid kraft pulp to gaseous compounds. As interaction time between laser beam and dried kraft pulp continues, hypothesis is that three auto ignition processes occurs. Auto ignition of substance is the lowest temperature in which it will spontaneously ignite in a normal atmosphere without an external source of ignition, such as a flame or spark. Three auto ignition processes appears in range of MADM and MBDM, namely: 1. temperature of auto ignition of hydrogen atom (H2) is 500ºC, 2. temperature of auto ignition of carbon monoxide molecule (CO) is 609ºC and 3. temperature of auto ignition of carbon atom (C) is 700ºC. These three auto ignition processes leads to formation of plasma plume which has strong emission of radiation in range of visible light. Formation of this plasma plume can be seen as increase of intensity in wavelength range of ~475-652 nm. Pyrometer shows maximum temperature just after this ignition. This plasma plume is assumed to scatter laser beam so that it interacts with larger area of dried kraft pulp than what is actual area of beam cross-section. This assumed scattering reduces also peak intensity. So result shows that assumably scattered light with low peak intensity is interacting with large area of hole edges and due to low peak intensity this interaction happens in low temperature. So interaction between laser beam and dried kraft pulp turns from evolution of hydrogen to evolution of hydrocarbons. This leads to black colour of hole edges.