Esta investigação experimental teve como finalidade de avaliar os efeitos do ultra-som pulsado de baixa intensidade sobre a regeneração do miométrio e do endométrio de ratas submetidas à uterotomia. Foram utilizadas neste experimento 20 ratas adultas da raça Wistar, submetidas a uma uterotomia mediante incisão longitudinal de 1,5 cm total de uma das paredes do corno uterino. As ratas foram divididas em 2 grupos de 10 animais cada, sendo que um grupo foi submetido à estimulação ultra-sônica por 10 dias durante 15 minutos diários e outro grupo, chamado controle, foi submetido à estimulação fictícia pelo mesmo tempo e período. Seis horas antes do sacrifício, os animais receberam via intramuscular 0,10 mg de colchicina para cada 100 g de peso corporal com a finalidade de bloquear as mitoses em metáfase. A avaliação dos tecidos baseou-se na análise comparativa entre a contagem de células em mitose do endométrio e do miométrio de animais estimulados com o de animais controle. Os achados morfológicos foram analisados estatisticamente e são sugestivos de que o U.S.P. estimula a regeneração do miométrio bem como do endométrio de ratas. / This experimental investigation had the purpose to evaluate the low-intensity pulsed ultrasound effects under the regeneration of the myometrium and the endometrium of the rats that were submitted to uterotomia. It was used, in this experiment, twenty adult rats of the Wistar race, submitted to uterotomia beyond the longitudinal incision of total 1, 5 cm of one of the uterine horn walls. The rats were divided in two groups of ten animals each, the first group went trough fifteen daily minutes ultra-sound stimulation during ten days, and the second group, called control, went through fictional stimulation by the same time and period of the first group. Six hours before the sacrifice, the animals received, by intra muscular, 0, 10 mg of colchicine for each 100 g of body weight, with the intention to block the mitosis in metaphase. The evaluation of the tissue was based on the comparative analysis between the mitosis cell count of the stimulated animals\' endometric tissue and the control animals\' one. The morphologic findings were statistically analyzed.

Esta investigação tem a finalidade estudar experimentalmente os efeitos do ultra-som pulsado de baixa intensidade sobre a espermatogênese de ratos pré-púberes e adultos. Foram utilizados 40 ratos machos da raça Wistar, sendo 20 pré-púberes e 20 adultos, os quais tiveram os testículos estimulados por 15 minutos durante 10 dias consecutivos. Cada grupo experimental constou de 10 animais pré-púberes ou adultos, estimulados com o ultra-som pulsado de baixa intensidade ou não estimulados. Administrou-se Colchicina, 6 horas antes do sacrifício dos animais com a finalidade de bloquear a divisão das células em metáfase para facilitar a avaliação do ciclo espermatogenético. Mediante morfometria estimou-se as áreas dos túbulos seminíferos e fez-se a avaliação dos estadios do ciclo espermatogenético quando foi constatado um aumento significativo das áreas dos túbulos seminíferos dos animais estimulados. O ciclo espermatogenético de ratos pré-púberes e adultos foi avaliado mediante contagens de associações celulares do ciclo nos estadios VII e VIII e XIV, correspondentes ao fim e início de cada ciclo. Houve aumento temporal do ciclo espermatogenético por apresentar maior número de associações com características dos estadios VIII significando acentuada maturidade de espermatozóides nos ratos pré-púberes estimulados. Os testículos dos animais adultos estimulados apresentaram aumento de peso em relação aos dos controles, exibindo uma diferença significativa. Nossos resultados são compatíveis com a hipótese de que o ultra-som pulsado de baixa intensidade estimula o aumento do peso dos testículos dos ratos adultos e das áreas dos túbulos seminíferos, bem como acelerando o ciclo espermatogenético em ratos pré-púberes. / This is an experimental study of the effects of low intensity pulsed ultrasound on the spermatogenesis of prepubertal and adult male rats. Forty male Wistar rats - twenty prepubertal and twenty adults -, whose testicles were stimulated for fifteen minutes for ten consecutive days were studied. Each experimental group was composed of ten prepubertal or adult animals, stimulated with low intensity pulsed ultrasound or not. Six hours before killing, the rats were given Colchicine to block the division of metaphasic cells, in order to facilitate the assessment of the spermatogenetic cycle. The area of the seminiferous tubule was done estimated by morphometry and the stages of spermatogenetic cycle were assessed, showing a significant increase of the areas of the seminiferous tubules of the stimulated animals. The spermiogenesis of prepubertal and adult rats was assessed through counts of cell associations in the stages VII and VIII and XIV, corresponding to the end and beginning of each cycle. There was a temporal increase in the spermatogenetic cycle due to a higher number of the associations with stage VIII characteristics, which means accentuated sperm cell maturity of the stimulated prepubertal rats. The testicles of the stimulated animals were weight increase regarding the of the control animals, showing a significant difference. Our results are compatible with the hypothesis that the low intensity pulsed ultrasound stimulates the increase of the testicle weight, the rats adults, and the area of the seminiferous tubules as well as accelerating the spermatogenetic cycle in rats prepubertal.

"The ablative Teflon pulsed plasma thruster (PPT) is an onboard electromagnetic propulsion enabling technology for small spacecraft missions. The integration of PPTs onboard spacecraft requires the understanding and evaluation of possible thruster/spacecraft interactions. To aid in this effort the work presented in this thesis is directed towards the development and application of Langmuir probe techniques for use in the plume of PPTs. Double and triple Langmuir probes were developed and used to measure electron temperature and density of the PPT plume. The PPT used in this thesis was a laboratory model parallel plate ablative Teflon® PPT similar in size to the Earth Observing (EO-1) PPT operating in discharge energies between 5 and 40 Joules. The triple Langmuir probe was operated in the current-mode technique that requires biasing all three electrodes and measuring the resulting probe currents. This new implementation differs from the traditional voltage-mode technique that keeps one probe floating and requires a voltage measurement that is often susceptible to noise in the fluctuating PPT plume environment. The triple Langmuir probe theory developed in this work incorporates Laframboise’s current collection model for Debye length to probe radius ratios less than 100 in order to account for sheath expansion effects on ion collection, and incorporates the thin-sheath current collection model for Debye length to probe radius ratios greater than 100. Error analysis of the non-linear system of current collection equations that describe the operation of the current-mode triple Langmuir probe is performed as well. Measurements were taken at three radial locations, 5, 10, and 15 cm from the Teflon® surface of the PPT and at angles of 20 and 40 degrees to either side of the thruster centerline as well as at the centerline. These measurements were taken on two orthogonal planes, parallel and perpendicular to the PPT electrodes. A data-processing software was developed and implements the current-mode triple Langmuir probe theory and associated error analysis. Results show the time evolution of the electron temperature and density. Characteristic to all the data is the presence of hot electrons of approximately 5 to 10 eV at the beginning of the pulse, occurring near the peak of the discharge current. The electron temperature quickly drops off from its peak values to 1-2 eV for the remainder of the pulse. Peak electron densities occur after the peak temperatures. The maximum electron density values on the centerline of the plume of a laboratory PPT 10 cm from the Teflon® surface are 6.6x10^19 +/- 1.3x10^19 m^-3 for the 5 J PPT, 7.2x10^20 +/- 1.4x10^20 m^-3 for the 20 J PPT, and 1.2x10^21 +/- 2.7x10^20 m^-3 for the 40 J PPT. Results from the double Langmuir probe taken at r=10 cm, theta perpendicular=70 degrees and 90 degrees of a laboratory PPT showed good agreement with the triple probe method."

Pulsed Detonation Engines (PDEs) have the potential to revolutionize fight by better utilizing the chemical energy content of reactive fuel/air mixtures over conventional combustion processes. Combustion by a super-sonic detonation wave results in a significant increase in pressure in addition to an increase in temperature. In order to harness this pressure increase and achieve a high power density, it is desirable to operate PDEs at high frequency. The process of detonation initiation impacts operating frequency by dictating the length of the chamber and contributing to the overall cycle time. Therefore a key challenge in the development of a practical PDEs is the requirement to rapidly initiate a detonation in hydrocarbon-air mixtures. This thesis evaluates the influence of spark energy and airflow velocity on this challenging initiation process. The influence of spark energy, number of sparks and airflow velocity on Deflagration-to-Detonation Transition (DDT) was studied during cyclic operation of a small-scale PDE at the General Electric Global Research Center. Experiments were conducted in a 50 mm square transitioning to cylindrical channel PDE with optical access operating with stoichiometric ethylene-air mixture. Total spark energy was varied from 250 mJ to 4 J and was distributed between one and four spark plugs located in the same axial location. Initial flame acceleration was imaged using high-speed shadowgraph and was characterized by the time to reach 20 cm from the spark plug. Measurements of detonation wave velocity and emergence time, the time it takes the detonation wave to exit the tube, was measured using dynamic pressure transducers and ionization probes. It was found that the flame front spread was faster at higher spark energies and with more spark locations. Initial flame acceleration was 16% faster for the 4-spark, 4 J case when compared to the baseline 1-spark, 1 J case. When looking at the effect of airflow on the influence of spark energy, it was found that airflow had a larger effect on emergence time at high energies, versus energies less than 1 J. Finally, for a selected case of 0.25 J spark energy and 4 sparks, the velocity of the fuel-air mixture during fill was found to have a varying influence on detonation initiation and emergence time.

The present study describes the growth and characterization of pulsed laser ablated Bao.sSro.sTiOs (BST) thin films. Emphasis has been laid on the study of a plausible correlation between structure and property in order to optimize the processing parameters suitably for required application. An attempt has been made to understand the basic properties such as, origin of dielectric response, charge transfer under low and high-applied electric fields across the BST capacitor and finally the dielectric breakdown process. Chapter 1 gives a brief introduction on the application of ferroelectric thin films in microelectronic industry and its growth techniques. It also addresses the present issues involved in the introduction of BST as a capacitor material for high-density dynamic random access memories. Chapter 2 outlines the motivation for the present study and briefly outlines the research work involved. Chapter 3 describes the experimental procedure involved in the growth and characterization of BST thin films using pulsed laser ablation technique. Details include the setup design for PLD growth, material synthesis for the ceramic targets, deposition conditions used for thin film growth and basic characterizations methods used for study of the grown films. Chapter 4 describes the effect of systematic variation of deposition parameters on the physical and electrical properties of the grown BST films. The variation in processing conditions has been found to directly affect the film crystallinity, structure and morphology. The change observed in these physical properties may also be correlated to the observed electrical properties. This chapter summarizes the optimal deposition conditions required for growing BST thin films using a pulsed laser ablation technique. Microstructure of BST films has been categorized into two types: (a) Type I structure, with multi-grains through the film thickness, for amorphous as-grown films after high temperature annealing (exsitu crystallized), and (b) columnar structure (Type II) films, which were as-grown well-crystallized films, deposited at high temperatures. The ac electrical properties have been reviewed in detail in Chapter 5. Type I films showed a relatively lower value of dielectric constant (e ~ 426) than Type II films with dielectric constant around 567. The dissipation factors were around 0.02 and 0.01 for Type I and Type II films respectively. The dispersion in the frequency domain characteristics has been quantitatively explained using Jonscher's theory. Complex impedance spectroscopy employed showed significant grain boundary response in the case of multi-grained Type I films while negligible contribution from grain boundaries has been obtained in the case of columnar grained Type II BST films. The average relaxation time r obtained from the complex impedance plane plots show almost three orders higher values for Type I films. The obtained results suggest that in multi-grained samples, grain boundary play a major role in electrical properties. This has been explained in accordance to a model proposed on the basis of depleted grains in the case of Type I films where the grain sizes are smaller than the grain boundary depletion width. Chapter 6 describes the dc leakage properties of the grown BST thin films and the influence of microstructure on the leakage properties. It was evident from the analysis of the graph of leakage current against measurement temperature, that, the observed leakage behavior in BST films, can not be attributed to a single charge transport mechanism. For Type I films, the Arrhenius plot of the leakage current density with 1000/T exhibits different regions with activation energy values in the range of 0.5 and 2.73 for low fields (2.5kV/cm). The activation energy changes over to 1.28 eV at high fields (170 kV/cm). The obtained values agree well with that obtained from the ac measurements, thus implying a similarity in the origin of the transport process. The activation energy value in the range of 0.5 eV is attributed to the electrode/film Schottky barrier, while the value in the range of 2.73 eV is due to deep trap levels originating from Ti+3 centers. The value in the range of 1.28 eV has been attributed to oxygen vacancy motion. Similar results have been obtained from the Arrhenius plot of the leakage current for Type II films. In this case, only two different activation energy values can be identified in the measured temperature and applied electric field range. At low fields the activation energy value was around 0.38 eV while at high fields the value was around 1.06 eV. These values have been identified to be originating from the electrode/film Schottky barrier and oxygen vacancy motion respectively. Thus a complete picture of the charge transport process in the case of BST thin film may be summarized as comprising of both electronic motion as well as contribution from oxygen vacancy motion. The effect of electrical stress on the capacitance-voltage (C-V) and the leakage current has been analyzed in Chapter 7. From the change in the zero bias capacitance after repeated electron injection through the films the values of the electronic capture cross-section and the total trap density for Type I and II films have been estimated. The results showed higher values for Type I film in comparison to Type II films. The difference has been attributed to the presence of grain boundaries and a different interface in the case of Type I films when compared to Type II films where the absence of grain boundaries is reflected in the columnar microstructure. A study of the time-dependent-dielectric-breakdown (TDDB) characteristics under high fields for Type I and Type II films showed higher endurance for Type I film. On the other hand space-charge-transient characteristics have been observed in the case of Type II films at elevated temperature of measurement. Mobility and activation energy values extracted from the transient characteristics are found to be in the range of 1 x 10~12 cm2 /V-sec and 0.73 eV respectively, suggesting a very slow charge transport process, which has been attributed to the motion of oxygen vacancies. An overall effect of electrical stress suggested that oxygen vacancy motion can be related to the observed resistance degradation and TDDB, which has been further enhanced by the combination of high temperature and high electric fields. Chapter 8 deals with the effect of intentional doping in the BST films. The doping includes Al at the Ti-site, Nb in the Ti-site and La at the Ba/Sr-site. The effect of doping was observed both on the structure and electrical properties of the BST films. Acceptor doping of 0.1 atomic 7c Al was found to decrease the dielectric constant as well as the leakage current. For higher concentration of acceptor-dopant, the leakage current was found to increase while showing space-charge-transient in the TDDB characteristics, again suggesting the effect of increased concentration of oxygen vacancies. Donor doping using 2 atomic % La and Xb significantly improved the leakage as well as the TDDB characteristics by reducing the concentration of oxygen vacancies. A further procedure using graded donor doping in the BST films exhibits even better leakage and TDDB properties. An unconventional, graded doping of donor cations has been carried out to observe the impact on leakage behavior, in particular. The leakage current measured for a graded La-doped BST film show almost six orders of lower leakage current in comparison to undoped BST films, while endurance towards breakdown has been observed to increase many-fold. Chapter 9 highlights the main findings of the work reported in this thesis and lists suggestions for future work, to explore new vistas ahead.

A pulsed-plasma jet (called a "spark-jet" by other researchers), is a high-speed synthetic jet that is generated by striking an electrical discharge in a small cavity. The gas in the cavity pressurizes owing to the heating and is allowed to escape through a small orifice. A series of experiments were conducted to determine the characteristics of the pulsed-plasma jet issuing into stagnant air at a pressure of 45 Torr. These results show that typical jet exit velocities of about 250 m/s can be induced with discharge energies of about 30 mJ per jet. Furthermore, the maximum pulsing frequency was found to be about 5 kHz, because above this frequency the jet begins to misfire. The misfiring appears to be due to the finite time it takes for the cavity to be recharged with ambient air between discharge pulses. The velocity at the exit of the jet is found to be primarily dependent on the discharge current and independent of other discharge parameters such as cavity volume and orifice diameter. Temperature measurements are made using optical emission spectroscopy and reveal the presence of considerable non-equilibrium between rotational and vibrational modes. The gas heating efficiency was found to be 10% and this parameter is shown to have a direct effect on the plasma jet velocity. These results indicate that the pulsed-plasma jet creates a sufficiently strong flow perturbation that is holds great promise as a supersonic flow actuator. An experimental study is conducted to characterize the performance of a pulsed-plasma jet for potential use in supersonic flow control applications. To obtain an estimate of the relative strength of the pulsed-plasma jet, the jet is injected normally into a Mach 3 cross-flow and the penetration distance is measured by using schlieren imaging. These measurements show that the jet penetrates 1.5 [delta], where [delta] is the boundary layer thickness, into the cross-flow and the jet-to-crossflow momentum flux ratio is estimated to be 0.6. An array of pulsed-plasma jets was issued from different locations upstream of a 30-degree compression ramp in a Mach 3 flow. Furthermore, two different jet configurations were used: normal injection and pitched and skewed injection. The pitched and skewed configuration was used to see if the jets could act as high-bandwidth pulsed vortex generators. The interaction between the jets and the separation shock was studied using phase-locked schlieren imaging. Results show that the plasma jets cause a significant disturbance to the separation shock and clearly influence its unsteadiness. While all plasma jet configurations tested caused an upstream motion of the separation shock, pitched and skewed plasma jets caused an initial downstream shock motion before the upstream motion, demonstrating the potential use of these plasma jets as vortex generator jets. The effect of the plasma jet array on the separation shock unsteadiness is studied in a time-resolved manner by using 10 kHz schlieren imaging and fast-response wall pressure measurements. An array of three pulsed-plasma jets, in a pitched and skewed configuration, is used to force the unsteady motion of the interaction formed by a 24° compression ramp in a Mach 3 flow. The Reynolds number of the incoming boundary layer is Re[theta]=3300. Results show that when the pulsed jet array is placed upstream of the interaction, the jets cause the separation shock to move in a quasi-periodic manner, i.e., nearly in sync with the pulsing cycle. As the jet fluid convects across the separation shock, the shock responds by moving upstream, which is primarily due to the presence of hot gas and hence the lower effective Mach number of the incoming flow. Once the hot gases pass through the interaction, the separation shock recovers by moving downstream, and this recovery velocity is approximately 1% to 3% of the free stream velocity. With forcing, the low-frequency energy content of the pressure fluctuations at a given location under the intermittent region decreases significantly. This is believed to be a result of an increase in the mean scale of the interaction under forced conditions. Pulsed-jet injection are also employed within the separation bubble, but negligible changes to the separation shock motion were observed. These results indicate that influencing the dynamics of this compression ramp interaction is much more effective by placing the actuator in the upstream boundary layer. / text

No description available.

Perovskite based artificial superlattices has recently been extensively investigated due to the immense promise in various device applications. The major applications include non-volatile random access memories, microwave devices, phase shifters voltage tunable capacitor applications etc. In this thesis we have taken up the investigation of two different types of symmetric superlattices, viz. BaZrO3/BaTiO3 and SrTiO3/BaZrO3, with possible applicability to voltage tunable devices. Chapter 1 deals with the introduction to the perovskite based functional oxides. Their various applications and the specific requirements for voltage tunable device applications has also been discussed in detail. The basic properties of BaTiO3 and SrTiO3, which are well documented in the literature, have been reviewed. The fundamental physics of interfacial interactions that influence the properties of superlattices is also discussed using existing models. The reason behind the choice of constructing artificial superlattices of BaZrO3/BaTiO3 and SrTiO3/BaZrO3 and the motivation behind this thesis is outlined. Chapter 2 gives a brief description of the basic characterization techniques that has been employed for studying the thin films. These include pulsed laser deposition of oxide thin films, structural characterization using X-Ray Diffraction and Atomic Force Microscope and electrical characterization of thin film metal-insulator-metal structures. The basic principle behind the techniques has also been included in various sections of this chapter. Chapter 3 introduces the reader to basic properties of the less studied perovskite material BaZrO3, one of the parent components of Ba(Zr,Ti)O3 based ceramics for high frequency applications. BaZrO3 is the common material in both the types of superlattices studied in this thesis. Initially the growth of polycrystalline BaZrO3 on (111)Pt/TiO2/SiO2/Si has been elaborated in this chapter. After characterizing the crystalline quality of the films and optimizing the growth conditions, epitaxial BaZrO3 films has been grown on (001) SrTiO3 substates. Dielectric properties of epitaxial BaZrO3 film have been measured as a function of temperature and frequencies. The electric field tunability of BaZrO3 films has been calculated from capacitance-voltage data for comparison with superlattice structures. Chapter 4 deals with the basic considerations involving growth of artificial superlattices and multilayers using pulsed laser ablation technique. The fundamental differences between formation of multilayers and superlattices have also been discussed, and the basic considerations for optimizing growth parameters are analyzed in this chapter. X-ray θ-2θ and φ-scans have been performed to investigate crystal quality of superlattices. The growth rates calculated from the satellite reflections in X-ray θ-2θ scans indicate fair degree of control over the growth and φ-scans confirms epitaxial cube-on cube growth of both types of superlattices. Atomic Force microscopy has been used to hcaracterize the film quality and surface morphology of superlattice structures and it has been found that the films have a very smooth surface with rms roughness of the order of few nanometres. Chapter5 deals with the detailed electrical characterization of both types of superlattices structures. Dielectric response showed nearly temperature invariance for both types of superlattices. Polarization measurements show that the heterostructures are in paraelectric state. Even for paraelectric/ferroelectric BaZrO3/BaTiO3 superlattices, stress induced stabilization of the paraelectric state is exhibited in low period superlattices. Paraelectric/paraelectric-SrTiO3/BaZrO3 superlattices exhibited a tunability of ~20% at intermediate modulation periods and an extremely stable dissipation factor with respect to temperature which is very attractive for device application point of view. A maximum tunability of ~40% has been observed for lowest period BaZrO3/BaTiO3 superlattice. Relatively high Quality Factors has been observed for both type of superlattices and their dependence on the modulation periods has been analyzed. Dielectric relaxation data showed that Maxwell-Wanger type of behaviour is exhibited but the presence of a conductance component G had to be realized in the equivalent circuit representation, which originates from the observation of a square law dependence of the alternating current on the frequency. Finally DC electrical characteristics were investigated as a function of temperature to determine the type of conduction mechanism that is involoved. The data has been analyzed using existing theories of high field conduction in thin dielectric films and it has been found that at different temperature ranges, the conduction mechanism varied from bulk limited Poole-Frenkel to Space Charge limited conduction. The activation energy calculation indicate that the physical processes responsible for dielectric relaxation and dc conduction are identical.

Einleitung Erkrankungen des Bewegungsapparates haben bei Milchkühen eine hohe wirtschaftliche Bedeutung sowie enorme Auswirkungen auf das Tierwohl. Etwa 90 % der Lahmheiten beim Rind werden durch Klauenerkrankungen hervorgerufen. Die Ursachen dieser Klauenerkrankungen sind multifaktoriell und umfassen tier- und umweltassoziierte Faktoren. Die Pododermatitis aseptica diffusa ist eine der wichtigsten Ursachen für die Entstehung von umschriebenen Klauenlederhautentzündungen. In ihrer Pathogenese spielen Veränderungen der Zehendurchblutung eine zentrale Rolle. Die Pulsed-Wave (PW)-Dopplersonographie ist eine nicht invasive Technik zur Beurteilung des Blutflusses an Gefäßen und zur Untersuchung der Durchblutung von Organen. Jedoch liegen keine PW-Dopplersonographischen Untersuchungen an der Zehe des Rindes in der Literatur vor. Ziele der Untersuchungen Ziel der Untersuchungen war es, die Zehendurchblutung bei Rindern, die an einer Pododermatitis circumscripta solearis oder parietalis litten, im Milchviehbetrieb zu erfassen. Dazu wurde in einem ersten Schritt die Methodik der PW-Dopplersonographie an der Zehe der Hintergliedmaßen von gesunden Kühen etabliert. In einem zweiten Schritt wurden Blutflussmerkmale an den Hintergliedmaßen lahmer Kühe, die an einer Pododermatitis circumscripta solearis oder parietalis litten, erfasst, um Auswirkungen der Entzündung sowie weiterer als relevant erscheinender Einflussfaktoren für die Zehendurchblutung zu untersuchen. Material und Methoden In der Publikation 1 wurden 22 gesunde Deutsch Holstein Kühe einbezogen. Die Versuchstiere wurden im Betrieb einer klinischen Untersuchung inklusive einer Lahmheitsbeurteilung sowie einer Klauenpflege aller Gliedmaßen unterzogen. Am zweiten Versuchstag wurde eine sonographische Untersuchung beider Hintergliedmaßen am stehenden Tier durchgeführt. Zur sonographischen Untersuchung wurde das MyLab One (Esaote Deutschland GmbH) mit einem Linearschallkopf (10 MHz) ohne Vorlaufstrecke verwendet. Mittels Brightness(B)-Mode wurden Weichteilgewebe, synoviale Einrichtungen und Blutgefäße distal des Tarsus untersucht. In der Arteria (A.) interdigitalis wurde der Blutfluss mittels PW-Dopplersonographie beurteilt. Die Auswertung der Daten erfolgte mit dem Programm MyLap Desk auf einem Laptop. In die Publikation 2 wurden 33 lahme und 11 gesunde Deutsch Holstein Kühe einbezogen. Die lahmen Kühe litten an einer superfiziellen bis profunden Pododermatitis an der Außenklaue einer Hintergliedmaße. Die klinische und sonographische Untersuchung erfolgte wie in der Publikation 1 beschrieben. Für die statistische Bearbeitung der Daten wurde die procedure mixed (SAS, Version 9.4) verwendet. Ergebnisse In den Publikationen 1 und 2 konnte an 112 von 132 Hintergliedmaßen bei 66 Kühen ein auswertbares PW-Doppler-Signal gemessen werden. Bei 17 der 20 nicht auswertbaren Hintergliedmaßen lag nur eine mäßige B-Mode-Bildqualität vor. Die lahmen Kühe trippelten bei der sonographischen Untersuchung mehr als die gesunden Kühe. Blutflusskurventypen mit einem niedrigen peripheren Gefäßwiderstand liegen vor allem an den Hintergliedmaßen lahmer Kühe und Kurventypen mit einem hohen Widerstand am häufigsten bei gesunden Kühen vor. Lahme Kühe haben im Vergleich zu nicht-lahmen Kühen einen erhöhten Gefäßdurchmesser (D) und eine gesteigerte Blutflussrate (BF) sowie enddiastolische Blutflussgeschwindigkeit. Es bestehen keine Unterschiede zwischen der betroffenen Gliedmaße und der Gegengliedmaße lahmer Kühe. Ein numerisch höherer D, eine höhere BF sowie maximale systolische und maximale mittlere Blutflussgeschwindigkeit liegen bei Kühen mit einer mittelgradigen Lahmheit vor. Schlussfolgerungen Die PW-Dopplersonographie in Kombination mit dem in der Studie verwendeten Untersuchungsgang ist für die Messung des Blutflusses in der A. interdigitalis an den Hintergliedmaßen des Rindes sehr gut geeignet. Sowohl die bei den Kühen gefundenen Blutflusskurvenprofile als auch die quantitativen Blutflussmerkmale sind mit Werten von Pferden vergleichbar. Es liegt eine gesteigerte Durchblutung an den betroffenen Zehen und denen der Gegengliedmaße von lahmen Kühen im Vergleich zu gesunden Kühen vor. Nicht nur das Vorliegen einer umschriebenen Klauenlederhautentzündung, sondern auch ihr zeitlicher Verlauf, die Auswirkungen einer aktivierten Entzündungskaskade, das Vorliegen einer chronischen Klauenrehe und vor allem die Gewichtsbelastung und die Gewichtsverschiebung zwischen den Hintergliedmaßen müssen in die Beurteilung des digitalen Blutflusses einbezogen werden. Die erstmalig an der Rinderzehe ermittelten Blutflussdaten stellen eine gute Grundlage für weitere Forschungen auf dem Gebiet der Klauenrehe-Pathogenese dar.:Inhaltsverzeichnis 1 Einleitung 1 2 Literaturübersicht 3 2.1 Pododermatitis aseptica diffusa beim Rind 3 2.1.1 Definition 3 2.1.2 Symptomatik 3 2.1.2.1 Klinisches Stadium 3 2.1.2.1.1 Akute Form 3 2.1.2.1.2 Subakute Form 4 2.1.2.1.3 Chronische Form 4 2.1.2.2 Subklinisches Stadium 5 2.1.3 Ätiologie 5 2.1.3.1 Fütterung 5 2.1.3.1.1 Zusammenhang zwischen Fütterung und Dysfunktion des Blutgefäßsystems der Zehe 5 2.1.3.1.2 Kohlenhydrate 7 2.1.3.1.3 Proteine und Aminosäuren 9 2.1.3.1.4 Lipide 10 2.1.3.1.5 Spurenelemente 10 2.1.3.1.5.1 Kupfer 10 2.1.3.1.5.2 Zink 10 2.1.3.1.5.3 Mangan 11 2.1.3.1.5.4 Selen 11 2.1.3.1.6 Vitamine 11 2.1.3.1.6.1 Biotin 11 2.1.3.1.6.2 Vitamine A, D, E 12 2.1.3.1.7 Toxine 12 2.1.3.1.8 Bewertung der Versorgung mit Mineralstoffen, Spurenelementen und Vitaminen für die Klauengesundheit 12 2.1.3.2 Mechanische Faktoren 13 2.1.3.2.1 Digitales Fettpolster 13 2.1.3.2.2 Hypertrophie der Außenklaue an den Hintergliedmaßen 14 2.1.3.2.3 Dünne Sohlen 14 2.1.3.3 Hormonelle Veränderungen während der Transitphase 15 2.1.3.4 Haltung 17 2.1.4 Pathogenese 18 2.1.5 Reheassoziierte Klauenlederhautentzündungen 19 2.2 Anatomie des Blutgefäßsystems beim Rind 20 2.2.1 Arterien der Hintergliedmaße 20 2.2.1.1 Arterien am Ober- und Unterschenkel 20 2.2.1.2 Arterien an Mittelfuß und Zehen 21 2.2.1.2.1 Plantares System 21 2.2.1.2.2 Dorsales System 21 2.2.2 Venen der Hintergliedmaße 21 2.2.2.1 Venen am Ober- und Unterschenkel 21 2.2.2.2 Venen an Mittelfuß und Zehen 22 2.2.2.2.1 Plantares System 22 2.2.2.2.2 Dorsales System 22 2.2.3 Blutgefäßsystem der Klauen 23 2.2.3.1 Arterien 23 2.2.3.2 Venen 23 2.2.3.3 Arterio-venöse Anastomosen 24 2.3 Bildgebende Verfahren zur Darstellung des Gefäßsystems 24 2.3.1 Allgemein 24 2.3.2 Brightness Mode Sonographie 25 2.3.2.1 Prinzip 25 2.3.2.2 Allgemeine Anwendung an der Gliedmaße 25 2.3.2.3 Spezielle Anwendung zur Untersuchung des Blutgefäßsystems an der Gliedmaße distal des Tarsus 26 2.3.3 Pulsed-Wave-Dopplersonographie 27 2.3.3.1 Prinzip 27 2.3.3.2 Merkmale 29 2.3.3.3 Allgemeine Anwendung 30 2.3.3.4 Anwendung an der Gliedmaße 30 2.3.4 Weitere bildgebende Verfahren 33 2.3.4.1 Angiographie 33 2.3.4.1.1 Prinzip 33 2.3.4.1.2 Anwendung an der Gliedmaße 34 2.3.4.2 Szintigraphie 34 2.4 Zusammenfassende Schlussfolgerungen aus dem Literaturstudium 35 3 Publikation 1 37 4 Publikation 2 47 5 Diskussion 59 5.1 Auswahl des Messpunktes und Messbarkeit des Blutflusses 59 5.2 Verhalten 60 5.3 Gliedmaßenstellung 60 5.4 Qualitative Blutflussmerkmale 61 5.5 Quantitative Blutflussmerkmale 62 6 Zusammenfassung 66 7 Summary 68 8 Literaturverzeichnis 70 9 Danksagung 96 / Introduction Diseases of the locomotor system in dairy cattle have a huge economic and welfare importance. Nearly 90 % of lameness in cattle is caused by claw disease. The reasons are multifactorial and include animal as well as environmental factors. Claw horn disruption is the main cause for the development of claw horn lesions. Changes in the blood circulation of the toes play an essential role in their pathogenesis. Pulsed-Wave (PW)-Doppler ultrasonography is a non-invasive technique to evaluate the flow in blood vessels and to examine the blood circulation of an organ. However, there have not been any PW-Doppler ultrasonographical investigations for the bovine limb in the literature yet. Aims The objective of this investigation is to measure the blood flow of the toes in dairy cattle suffering from sole ulcer or white line disease in dairy farms. In a first step the PW-Doppler ultrasonography was established at the toe of hindlimbs in healthy dairy cattle. In a second step blood flow variables in the hindlimbs of lame cows affected by a sole ulcer or white line disease were recorded to evaluate the consequence of inflammation as well as to examine further factors seem to influence the blood flow of the toes. Material and Methods Twenty-two German Holstein cows were included in the first publication. The cows were examined clinically in the farm including an evaluation of the lameness score as well as a claw trimming of all limbs. One day after an ultrasonography was performed in standing position in both hind limbs. For the examination a MyLabOne (Esaote Deutschland GmbH) with a linear transducer without a standoff pad was used. Soft tissue, synovial structures and blood vessels distal of the tarsal region were examined by using a Brightness (B)-mode ultrasonography. In the interdigital arteria the blood flow was measured by PW-Doppler ultrasonography. The analysis of the data was carried out by the program MyLabDesk on a laptop. The second publication included 33 lame and 11 healthy German Holstein cows. The lame cows suffered from a superficial too profound sole ulcer or white line disease at the outer claw of one hind limb. The clinical and ultrasonographical examination took place analogically to the first publication. For the statistical analyses the MIXED procedure (SAS, version 9.4) was used. Results Combining both publications in 112 of 132 hindlimbs a usable PW-Doppler signal was generated. Seventeen of the 20 not usable signals the B-mode quality was moderate. During the ultrasonography lame cows pattered their limbs more often than healthy cows. Blood flow profiles with a low peripheral resistance are more common in the hindlimbs of lame cows and profiles with a high peripheral resistance are most frequent in healthy cows. Lame cows have a higher vessel diameter (D), blood flow rate (BF) and end-diastolic blood flow velocity compared to healthy cows. There was no difference in the affected compared to the opposite limbs of lame cows. A numerical higher D, BF as well as maximum systolic and maximum time-averaged mean blood flow velocity occurred in moderate lame cows compared to mild lame cows. Conclusions The PW-Doppler ultrasonography is well suited for the evaluation of the blood flow in the bovine interdigital artery at the hindlimbs. The observed blood flow profiles as well as quantitative blood flow parameters are comparable to data in horses. There is an increased blood circulation in the affected and the opposite limb of lame cows compared to healthy cows. Not only the existence of the claw horn lesions but also their chronological progress, the influence of the inflammatory cascade, the availability of chronic claw horn disruption and especially weight bearing and weight shifting between hindlimbs have to be considered in the assessment of the blood flow of toes. The for the first-time generated blood flow parameters provide a good basis for further investigations in the topic of claw horn disruption pathogenesis.:Inhaltsverzeichnis 1 Einleitung 1 2 Literaturübersicht 3 2.1 Pododermatitis aseptica diffusa beim Rind 3 2.1.1 Definition 3 2.1.2 Symptomatik 3 2.1.2.1 Klinisches Stadium 3 2.1.2.1.1 Akute Form 3 2.1.2.1.2 Subakute Form 4 2.1.2.1.3 Chronische Form 4 2.1.2.2 Subklinisches Stadium 5 2.1.3 Ätiologie 5 2.1.3.1 Fütterung 5 2.1.3.1.1 Zusammenhang zwischen Fütterung und Dysfunktion des Blutgefäßsystems der Zehe 5 2.1.3.1.2 Kohlenhydrate 7 2.1.3.1.3 Proteine und Aminosäuren 9 2.1.3.1.4 Lipide 10 2.1.3.1.5 Spurenelemente 10 2.1.3.1.5.1 Kupfer 10 2.1.3.1.5.2 Zink 10 2.1.3.1.5.3 Mangan 11 2.1.3.1.5.4 Selen 11 2.1.3.1.6 Vitamine 11 2.1.3.1.6.1 Biotin 11 2.1.3.1.6.2 Vitamine A, D, E 12 2.1.3.1.7 Toxine 12 2.1.3.1.8 Bewertung der Versorgung mit Mineralstoffen, Spurenelementen und Vitaminen für die Klauengesundheit 12 2.1.3.2 Mechanische Faktoren 13 2.1.3.2.1 Digitales Fettpolster 13 2.1.3.2.2 Hypertrophie der Außenklaue an den Hintergliedmaßen 14 2.1.3.2.3 Dünne Sohlen 14 2.1.3.3 Hormonelle Veränderungen während der Transitphase 15 2.1.3.4 Haltung 17 2.1.4 Pathogenese 18 2.1.5 Reheassoziierte Klauenlederhautentzündungen 19 2.2 Anatomie des Blutgefäßsystems beim Rind 20 2.2.1 Arterien der Hintergliedmaße 20 2.2.1.1 Arterien am Ober- und Unterschenkel 20 2.2.1.2 Arterien an Mittelfuß und Zehen 21 2.2.1.2.1 Plantares System 21 2.2.1.2.2 Dorsales System 21 2.2.2 Venen der Hintergliedmaße 21 2.2.2.1 Venen am Ober- und Unterschenkel 21 2.2.2.2 Venen an Mittelfuß und Zehen 22 2.2.2.2.1 Plantares System 22 2.2.2.2.2 Dorsales System 22 2.2.3 Blutgefäßsystem der Klauen 23 2.2.3.1 Arterien 23 2.2.3.2 Venen 23 2.2.3.3 Arterio-venöse Anastomosen 24 2.3 Bildgebende Verfahren zur Darstellung des Gefäßsystems 24 2.3.1 Allgemein 24 2.3.2 Brightness Mode Sonographie 25 2.3.2.1 Prinzip 25 2.3.2.2 Allgemeine Anwendung an der Gliedmaße 25 2.3.2.3 Spezielle Anwendung zur Untersuchung des Blutgefäßsystems an der Gliedmaße distal des Tarsus 26 2.3.3 Pulsed-Wave-Dopplersonographie 27 2.3.3.1 Prinzip 27 2.3.3.2 Merkmale 29 2.3.3.3 Allgemeine Anwendung 30 2.3.3.4 Anwendung an der Gliedmaße 30 2.3.4 Weitere bildgebende Verfahren 33 2.3.4.1 Angiographie 33 2.3.4.1.1 Prinzip 33 2.3.4.1.2 Anwendung an der Gliedmaße 34 2.3.4.2 Szintigraphie 34 2.4 Zusammenfassende Schlussfolgerungen aus dem Literaturstudium 35 3 Publikation 1 37 4 Publikation 2 47 5 Diskussion 59 5.1 Auswahl des Messpunktes und Messbarkeit des Blutflusses 59 5.2 Verhalten 60 5.3 Gliedmaßenstellung 60 5.4 Qualitative Blutflussmerkmale 61 5.5 Quantitative Blutflussmerkmale 62 6 Zusammenfassung 66 7 Summary 68 8 Literaturverzeichnis 70 9 Danksagung 96

Energy storage systems will likely be needed for future shipboard power systems that supply loads with high power variability such as pulsed power loads. The power generation in shipboard power systems may not be sufficient to satisfy the energy demands of the pulsed power load systems operating in conjunction with other ship service loads. Two fundamental items in evaluating the requirements of an energy storage system are the energy storage capacity and the ratings of the power conversion equipment that interfaces the energy device to the power system. The supply current of pulsed power load systems is aperiodic and cannot be described in terms of active power. Also, the RMS value and thus apparent power are only defined for periodic quantities. Therefore traditional methods of rating power equipment cannot be used. This thesis describes an approach to determine the ratings of an energy storage interface and the energy storage capacity of an energy storage device as a function of load and supply parameters. The results obtained using the proposed approach are validated with the results obtained from the simulation model of the generator supplying a pulsed power load in conjunction with an energy storage system. The energy storage system requirements for various pulsed power load profiles are obtained using the proposed approach. The method used for determining the ratings of an energy storage system utilizes an orthogonal decomposition of pulsed power load system supply current evaluated within a sliding window. The signals obtained from the decomposition are also useful in generating the control reference signals for the energy storage interface. Although the approach and methods are focused on a particular structure of the pulsed power load system, they may be generalized for use in any type of configuration of a pulsed power load system.