Computational and Experimental Investigation of the Grooved Roll in Paper Machine Environment

In the paper machine, it is not a desired feature for the boundary layer flows in the fabric and the roll surfaces to travel into the closing nips, creating overpressure. In this thesis, the aerodynamic behavior of the grooved roll and smooth rolls is compared in order to understand the nip flow phenomena, which is the main reason why vacuum and grooved roll constructions are designed. A common method to remove the boundary layer flow from the closing nip is to use the vacuum roll construction. The downside of the use of vacuum rolls is high operational costs due to pressure losses in the vacuum roll shell. The deep grooved roll has the same goal, to create a pressure difference over the paper web and keep the paper attached to the roll or fabric surface in the drying pocket of the paper machine. A literature review revealed that the aerodynamic functionality of the grooved roll is not very well known. In this thesis, the aerodynamic functionality of the grooved roll in interaction with a permeable or impermeable wall is studied by varying the groove properties. Computational fluid dynamics simulations are utilized as the research tool. The simulations have been performed with commercial fluid dynamics software, ANSYS Fluent. Simulation results made with 3- and 2-dimensional fluid dynamics models are compared to laboratory scale measurements. The measurements have been made with a grooved roll simulator designed for the research. The variables in the comparison are the paper or fabric wrap angle, surface velocities, groove geometry and wall permeability. Present-day computational and modeling resources limit grooved roll fluid dynamics simulations in the paper machine scale. Based on the analysis of the aerodynamic functionality of the grooved roll, a grooved roll simulation tool is proposed. The smooth roll simulations show that the closing nip pressure does not depend on the length of boundary layer development. The surface velocity increase affects the pressure distribution in the closing and opening nips. The 3D grooved roll model reveals the aerodynamic functionality of the grooved roll. With the optimal groove size it is possible to avoid closing nip overpressure and keep the web attached to the fabric surface in the area of the wrap angle. The groove flow friction and minor losses play a different role when the wrap angle is changed. The proposed 2D grooved roll simulation tool is able to replicate the grooved aerodynamic behavior with reasonable accuracy. A small wrap angle predicts the pressure distribution correctly with the chosen approach for calculating the groove friction losses. With a large wrap angle, the groove friction loss shows too large pressure gradients, and the way of calculating the air flow friction losses in the groove has to be reconsidered. The aerodynamic functionality of the grooved roll is based on minor and viscous losses in the closing and opening nips as well as in the grooves. The proposed 2D grooved roll model is a simplification in order to reduce computational and modeling efforts. The simulation tool makes it possible to simulate complex paper machine constructions in the paper machine scale. In order to use the grooved roll as a replacement for the vacuum roll, the grooved roll properties have to be considered on the basis of the web handling application.

Combinatorics on Words. New Aspects on Avoidability, Defect Effect, Equations and Palindromes

In this thesis we examine four well-known and traditional concepts of combinatorics on words. However the contexts in which these topics are treated are not the traditional ones. More precisely, the question of avoidability is asked, for example, in terms of k-abelian squares. Two words are said to be k-abelian equivalent if they have the same number of occurrences of each factor up to length k. Consequently, k-abelian equivalence can be seen as a sharpening of abelian equivalence. This fairly new concept is discussed broader than the other topics of this thesis. The second main subject concerns the defect property. The defect theorem is a well-known result for words. We will analyze the property, for example, among the sets of 2-dimensional words, i.e., polyominoes composed of labelled unit squares. From the defect effect we move to equations. We will use a special way to define a product operation for words and then solve a few basic equations over constructed partial semigroup. We will also consider the satisfiability question and the compactness property with respect to this kind of equations. The final topic of the thesis deals with palindromes. Some finite words, including all binary words, are uniquely determined up to word isomorphism by the position and length of some of its palindromic factors. The famous Thue-Morse word has the property that for each positive integer n, there exists a factor which cannot be generated by fewer than n palindromes. We prove that in general, every non ultimately periodic word contains a factor which cannot be generated by fewer than 3 palindromes, and we obtain a classification of those binary words each of whose factors are generated by at most 3 palindromes. Surprisingly these words are related to another much studied set of words, Sturmian words.

Indoeuropeistiikan uusi avaus Helsingin yliopistossa

Kirjallisuusarvostelu

Lipid peroxidation and total radical-trapping potential of the lungs of rats submitted to chronic and sub-chronic stress

Exposure to stress induces a cluster of physiological and behavioral changes in an effort to maintain the homeostasis of the organism. Long-term exposure to stress, however, has detrimental effects on several cell functions such as the impairment of antioxidant defenses leading to oxidative damage. Oxidative stress is a central feature of many diseases. The lungs are particularly susceptible to lesions by free radicals and pulmonary antioxidant defenses are extensively distributed and include both enzymatic and non-enzymatic systems. The aim of the present study was to determine lipid peroxidation and total radical-trapping potential (TRAP) changes in lungs of rats submitted to different models of chronic stress. Adult male Wistar rats weighing 180-230 g were submitted to different stressors (variable stress, N = 7) or repeated restraint stress for 15 (N = 10) or 40 days (N = 6) and compared to control groups (N = 10 each). Lipid peroxidation levels were assessed by thiobarbituric acid reactive substances (TBARS), and TRAP was measured by the decrease in luminescence using the 2-2'-azo-bis(2-amidinopropane)-luminol system. Chronic variable stress induced a 51% increase in oxidative stress in lungs (control group: 0.037 ± 0.002; variable stress: 0.056 ± 0.007, P < 0.01). No difference in TBARS was observed after chronic restraint stress, but a significant 57% increase in TRAP was presented by the group repeatedly restrained for 15 days (control group: 2.48 ± 0.42; stressed: 3.65 ± 0.16, P < 0.05). We conclude that different stressors induce different effects on the oxidative status of the organism.

Proteomic data show an increase in autoantibodies and alpha-fetoprotein and a decrease in apolipoprotein A-II with time in sera from senescence-accelerated mice

We evaluated changes in levels by comparing serum proteins in senescence-accelerated mouse-prone 8 (SAMP8) mice at 2, 6, 12, and 15 months of age (SAMP8-2 m, -6 m, -12 m, -15 m) to age-matched SAM-resistant 1 (SAMR1) mice. Mice were sacrificed, and blood was analyzed by 2-dimensional electrophoresis combined with mass spectrometry. Five protein spots were present in all SAMP8 serum samples, but only appeared in SAMR1 samples at 15 months of age except for spot 3, which also showed a slight expression in SAMR1-12 m sera. Two proteins decreased in the sera from SAMP8-2 m, -6 m, and -12 m mice, and divided into 2 spots each in SAMP8-15 m sera. Thus, the total number of altered spots in SAMP8 sera was 7; of these, 4 were identified as Ig kappa chain V region (M-T413), chain A of an activity suppressing Fab fragment to cytochrome P450 aromatase (32C2_A), alpha-fetoprotein, and apolipoprotein A-II. M-T413 is a monoclonal CD4 antibody, which inhibits T cell proliferation. We found that M-T413 RNA level was significantly enhanced in splenocytes from SAMP8-2 m mice. This agreed with serum M-T413 protein alterations and a strikingly lower blood CD4+ T cell count in SAMP8 mice when compared to the age-matched SAMR1 mice, with the latter negatively correlating with serum M-T413 protein volume. Age-related changes in serum proteins favored an increase in autoantibodies and alpha-fetoprotein and a decrease of apolipoprotein A-II, which occurred in SAMP8 mice at 2 months of age and onwards. These proteins may serve as candidate biomarkers for early aging.

Pulssitettu laserablaatio mikrofluidisten kanavistojen sarjatuotantomenetelmänä

Puolijohteiden yleistyttyä vuodesta 1948 alkaen, ovat elektroniset laitteet pienentyneet jatkuvasti tehojen kuitenkin kasvaessa. Kasvaneet tehotiheydet kuitenkin vaikeuttavat laitesuunnittelua, sillä puoljohdekomponenttien suorituskyvylle ja eliniälle on oleellista lämpötilojen ja lämpötilavaihteluiden minimointi. Perinteisen ilmajäähdytyksen lähestyessä rajojaan niin kokonaistehon kuin järkevän energiatehokkuudenkin suhteen, on parhaaksi seuraavaksi teknologiaksi ennustettu kaksifaasijäähdytystä, jonka suorituskyky ja energiatehokkuus ovat vaaditulla tasolla. Kaksifaasijäähdytyksen optimaaliselle toiminnalle tärkeää on hyvin suunniteltu ja tarkasti valmistettu lämmönsiirtopinta, jota kutsutaan mikrokanavistoksi. Pulssitettu laserkaiverrus on edistynyt valmistustekniikka, jonka tarkkuus ja luotettavuus sopisivat mikrokanavistojen valmistamiseen. Laserkaiverruksella saavutettavat lopputulokset vaihtelevat kuitenkin materiaalista riippuen ja kupari – jota käytetään yleisesti lämmönjohteena – on eräs huonoimmin lasertyöstöön reagoivista materiaaleista ja siksi on oleellista selvittää laser-kaiverruksen toimivuutta kuparisten mikrokanavistojen valmistuksessa. Pulssitetun laser-kaiverruksen eri variaatioista nanosekunti-luokan pulssinpituuksilla toimivat laitteet ovat jatkuvan tuotannon kannalta paras vaihtoehto niiden hyvän tuottavuuden, saatavuuden sekä kohtuullisen alkuinvestoinnin vuoksi. Käytännön kaiverruskokeiden perusteella selvisi, että menetelmä on laatunsa ja tarkkuutensa puolesta sopiva varsinaiseen tuotantoon. Kaiverruksen tehokkuus kuparia työstettäessä on kuitenkin ennakoituakin heikompi ja niin valmistus- kuin suunnitelu-prosessikin vaativat vielä jatkotutkimusta ja -kehitystä.

X-ray diffraction of a gram-negative bacterial membrane mimetic

This thesis applies x-ray diffraction to measure he membrane structure of lipopolysaccharides and to develop a better model of a LPS bacterial melilbrane that can be used for biophysical research on antibiotics that attack cell membranes. \iVe ha'e Inodified the Physics department x-ray machine for use 3.'3 a thin film diffractometer, and have lesigned a new temperature and relative humidity controlled sample cell.\Ve tested the sample eel: by measuring the one-dimensional electron density profiles of bilayers of pope with 0%, 1%, 1G :VcJ, and 100% by weight lipo-polysaccharide from Pse'udo'lTwna aeTuginosa. Background VVe now know that traditional p,ntibiotics ,I,re losing their effectiveness against ever-evolving bacteria. This is because traditional antibiotic: work against specific targets within the bacterial cell, and with genetic mutations over time, themtibiotic no longer works. One possible solution are antimicrobial peptides. These are short proteins that are part of the immune systems of many animals, and some of them attack bacteria directly at the membrane of the cell, causing the bacterium to rupture and die. Since the membranes of most bacteria share common structural features, and these featuret, are unlikely to evolve very much, these peptides should effectively kill many types of bacteria wi Lhout much evolved resistance. But why do these peptides kill bacterial cel: '3 , but not the cells of the host animal? For gramnegative bacteria, the most likely reason is that t Ileir outer membrane is made of lipopolysaccharides (LPS), which is very different from an animal :;ell membrane. Up to now, what we knovv about how these peptides work was likely done with r !10spholipid models of animal cell membranes, and not with the more complex lipopolysa,echaricies, If we want to make better pepticies, ones that we can use to fight all types of infection, we need a more accurate molecular picture of how they \vork. This will hopefully be one step forward to the ( esign of better treatments for bacterial infections.

Transverse dipole spin modes in quantum dots

We have carried out a systematic analysis of the transverse dipole spin response of a large-size quantum dot within time-dependent current density functional theory. Results for magnetic fields corresponding to integer filling factors are reported, as well as a comparison with the longitudinal dipole spin response. As in the two-dimensional electron gas, the spin response at high-spin magnetization is dominated by a low-energy transverse mode.

A Faster 2D Technique for the design of Combinational Digital Circuits Using Genetic Algorithm

Combinational digital circuits can be evolved automatically using Genetic Algorithms (GA). Until recently this technique used linear chromosomes and and one dimensional crossover and mutation operators. In this paper, a new method for representing combinational digital circuits as 2 Dimensional (2D) chromosomes and suitable 2D crossover and mutation techniques has been proposed. By using this method, the convergence speed of GA can be increased significantly compared to the conventional methods. Moreover, the 2D representation and crossover operation provides the designer with better visualization of the evolved circuits. In addition to this, a technique to display automatically the evolved circuits has been developed with the help of MATLAB

Femtosecond imaging-mode laser-induced breakdown spectroscopy

Many nonlinear optical microscopy techniques based on the high-intensity nonlinear phenomena were developed recent years. A new technique based on the minimal-invasive in-situ analysis of the specific bound elements in biological samples is described in the present work. The imaging-mode Laser-Induced Breakdown Spectroscopy (LIBS) is proposed as a combination of LIBS, femtosecond laser material processing and microscopy. The Calcium distribution in the peripheral cell wall of the sunflower seedling (Helianthus Annuus L.) stem is studied as a first application of the imaging-mode LIBS. At first, several nonlinear optical microscopy techniques are overviewed. The spatial resolution of the imaging-mode LIBS microscope is discussed basing on the Point-Spread Function (PSF) concept. The primary processes of the Laser-Induced Breakdown (LIB) are overviewed. We consider ionization, breakdown, plasma formation and ablation processes. Water with defined Calcium salt concentration is used as a model of the biological object in the preliminary experiments. The transient LIB spectra are measured and analysed for both nanosecond and femtosecond laser excitation. The experiment on the local Calcium concentration measurements in the peripheral cell wall of the sunflower seedling stem employing nanosecond LIBS shows, that nanosecond laser is not a suitable excitation source for the biological applications. In case of the nanosecond laser the ablation craters have random shape and depth over 20 µm. The analysis of the femtosecond laser ablation craters shows the reproducible circle form. At 3.5 µJ laser pulse energy the diameter of the crater is 4 µm and depth 140 nm for single laser pulse, which results in 1 femtoliter analytical volume. The experimental result of the 2 dimensional and surface sectioning of the bound Calcium concentrations is presented in the work.

Entwicklung und Validierung der Steigbildmethode zur Differenzierung von ausgewählten Lebensmitteln aus verschiedenen Anbausystemen und Verarbeitungsprozessen

Zusammenfassung (deutsch) Seit den 1980iger Jahren wächst die Bedeutung der sog. Bildschaffenden Methoden für die Bestimmung der Qualität ökologischer Produkte. Zu diesen Methoden gehört die Biokristallisation, Steigbild und Rundfilter-Chromatographie. Die Ergebnisse dieser Methoden sind Bilder, die anhand definierter Kriterien ausgewertet werden. Bei der Biokristallisation sind es mehr oder weniger geordnete Kristallisationen auf einer Glasplatte, bei dem Steigbild zweidimensionale Strukturen auf Chromatographiepapier. In der Vergangenheit wurden die Bilder von Spezialisten ausgewertet, die nach einer längeren Schulung produktspezifische Kriterien entwickelt hatten. Im Gegensatz zur Dünnschicht-Chromatographie, wo der einzelne Stoff von der Matrix separiert wird, ist das Ziel beim Steigbild, Strukturen der möglichst ganzen Probe zu erzeugen. Die Methode wurde von Kolisko in den 1929iger Jahren entwickelt, wobei eine Kombination aus Chromatographieprozess und Metallkomplexreaktionen genutzt wurde. Die Firma WALA entwickelte die Methode für die Kontrolle ihrer Produkte und setze Silbernitrat und Eisensulfat ein. Bisher wurde die Methode qualitativ beschreibend ausgewertet, wobei einzelne Bildelemente und deren Interaktion beschrieben wurden. Deshalb musste für die vorliegende Arbeit Auswertungsmethoden entwickelt werden, mit denen auch eine statistische Bearbeitung der Ergebnisse möglich ist (nominale Unterscheidung von proben anhand der Bilder). Die Methode wurde bisher in einer Reihe von Studien eingesetzt (u.a. die Unterscheidung von Produktionsweisen). Obwohl die Bilder nur qualitativ ausgewertet wurden, konnten geschulte Prüfpersonen Proben aus verschiedenen Anbausystemen anhand der Bilder trennen. Die Ergebnisse wurden aber nicht so dokumentiert, dass sie den Erfordernissen internationaler Standardnormen für Laboratorien genügten. Deshalb mussten für diese Arbeit zunächst die Prozeduren dokumentiert und eine systematische Untersuchung zu den Einflussgrößen durchgeführt werden. Dazu wurde die visuelle Bildauswertung entwickelt und standardisiert. Die visuelle Bildauswertung basiert auf morphologischen Kriterien der Bilder von den untersuchten Weizen- und Möhrenproben. Ein Panel aus geschulten Personen entwickelte dann die Kriterien und legte sie anhand von Referenzbildern fest. Die Bilder der vorliegenden Arbeit wurden mit der einfach beschreibenden Prüfung ausgewertet, wie sie aus der sensorischen Prüfung von Lebensmitteln übernommen werden konnte. Mit geschulten und ungeschulten Prüfpersonen wurden Weizenproben und verschiedene Möhrensäfte mit der sog. Dreiecksprüfung ausgewertet (von ISO 4120). Alle Laborprozeduren wurden dokumentiert. Mit der Anwendung dieser Prozeduren wurden Vergleichsversuche mit Laboren in Dänemark und Holland (BRAD, LBI) durchgeführt. Die Ergebnisse waren sowohl für Weizen- als auch für Möhrenproben vergleichbar, wobei alle drei Labore zwischen jeweils zwei Proben unterscheiden konnten. Die systematische Untersuchung zu den Einflussgrößen zeigte, dass das Unterscheidungsvermögen der Methode vor allem von den klimatischen Bedingungen während der Steigphasen beeinflusst wird. Auch die Präkonditionierung der Papiere hat einen großen Einfluss, während die Wasserqualität (ultra-filtriert, de-ionisiert, destilliert) eine untergeordnete Bedeutung hat. Für Weizen- und Möhrenproben wurde sowohl die Wiederholbarkeit als auch die Reproduzierbarkeit getestet. Die Unterschiede in den Bildern der verschiedenen Proben waren dabei immer größer als die Variation durch Proben- und Bildwiederholung und das Labor. Die so charakterisierte Methode wurde auf kodierte Proben von definierten Feldversuchen und auf Marktproben (Paarvergleich von Anbausystemen ökologisch und konventionell) angewandt, wobei als Ergebnis mehr als 90% der Proben mit der einfach beschreibenden Prüfung anhand der Bilder unterschieden werden konnten. Die Auswertung mit der Dreiecksprüfung zeigte, dass sowohl Sorten und Verarbeitungsschritte (Saft) als auch Anbauweisen signifikant getrennt wurden. Darüber hinaus wurde die Methode auch erfolgreich auf Apfelproben angewandt. Weitere Untersuchungen müssen zeigen, ob sich das Potential der Methode, verschiedene Fragen wie die Authentizitätsprüfung von Lebensmitteln verifizieren lassen.

The Li-like KLL-Auger spectrum of foil excitation Ne-projectiles

KLL-Auger transitions of the three electron system in Ne have been recorded in a coincidence experiment frec of contaminants from other systems. Energies as well as intensities are compared with calculated values.

Intro to Matlab for Oceanography: Micro-lectures

This is a collection of 12 micro-lectures, to be used by students in advance of practical sessions. Durations range for 3 min to 10 min. Topics include: ****** 1. Introduction ****** 2. Data classes ****** 3. Matrices ****** 4. Getting help ****** 5. Index notation ****** 6. 1- and 2-dimensional data ****** 7. 3-dimensional data ****** 8. Booleans (True/False) ****** 9. Designing a programme (Algorithms) ****** 10. Flow control: If-then statements ****** 11. Flow control: For-do loops ****** 12. Making nicer figures ******

Evaluación de la mecánica ventricular izquierda mediante speckle tracking en pacientes sanos en la Clínica Shaio

Introducción: La ecocardiografía es actualmente la técnica de imagen diagnóstica más utilizada para la evaluación de la anatomía y la función cardiovascular. En la actualidad se está utilizando la ecocardiografía por speckle tracking la cual permite una evaluación mas objetiva y confiable de la función ventricular, sin embargo se requieren valores de referencia que hagan que los valores obtenidos sean válidos y útiles para determinar en forma mas oportuna conductas previas al deterioro de su función. Objetivo general: Determinar los valores de referencia para mecánica ventricular izquierda mediante ecocardiografía bidimensional por speckle tracking con equipo Toshiba Artida con transductor multifrecuencia de 3 megahertzios en pacientes sin patología cardiaca conocida en la Fundación Clínica Shaio en el año 2014. Metodología: Análisis de una cohorte prospectiva de todos los pacientes que ingresaron a la Fundación Clínica Shaio para evaluación ecocardiográfica sin patología cardiaca conocida entre los meses Agosto y Diciembre del 2014. Resultados: Se presenta este estudio de la evaluación de la mecánica ventricular izquierda en adultos sanos, los resultados son similares a los obtenidos en estudios de referencia, sin embargo se consideran de gran importancia ya que de acuerdo a la guía actual de evaluación de la mecánica ventricular por strain rate es importante que cada equipo se encuentre estandarizado con el fin de tener resultados válidos de acuerdo a las diferentes patologías en las que se puede aplicar y a nuestra población.

Seed dormancy and germination of Ficus lundellii and tropical forest restoration

We investigated seed dormancy and germination in Ficus lundellii Standl. (Moraceae), a native species of Mexico's Los Tuxtlas tropical rain forest. In an 8-h photoperiod at an alternating diurnal (16/8 h) temperature of 20/30 degrees C, germination was essentially complete (96%) within 28 days, whereas in darkness, all seeds remained dormant. Neither potassium nitrate (0.05-0.2%) applied continuously nor gibberellic acid applied either continuously (10-200 ppm) or as a 24 hour pretreatment (2000 ppm) induced germination in the dark. Germination in the light was not reduced by a 24-h hydrochloric acid (0.1-1%) pretreatment, but it was reduced both by a 24-h pretreatment with either H2O2 (0. 1-5 M) or 5% HCl, or by more than 5 days of storage at 40 degrees C (4.5% seed water content). In a study with a 2-dimensional temperature gradient plate, seeds germinated fully and rapidly in the light at a constant temperature of 30 degrees C, and fully but less rapidly in the light at alternating temperatures with low amplitudes (< 12 degrees C) about the optimal constant temperature. The base, optimal and ceiling temperatures for rate of germination were estimated as 13.8, 30.1 and 41.1 degrees C, respectively. In all temperature regimes, light was essential for the germination of F lundellii seeds.