In this thesis I focus mainly in studying the process of star formation in both high redshift, and local star forming galaxies, by using an observational technique called integral field spectroscopy (IFS). Although these investigations are aimed at studying the star formation properties of these objects, throughout this work I will also discuss the geometric, kinematic, and chemical structures in the inter-stellar medium of these galaxies, which are intimately connected with the process of star formation itself. The studies presented here were conducted under the umbrella of two different projects. First, the HETDEX Pilot Survey for Emission Line Galaxies, where I have studied the properties of Ly-alpha emitting galaxies across the 2<z<4 range, with an emphasis in trying to understand the process by which Ly-alpha photons, produced in large quantities in the active star forming regions, are able to escape the ISM of these objects, allowing us to detect them in the Ly-alpha line. The second project from which results are presented here is the VIRUS-P Exploration of Nearby Galaxies (VENGA), an ongoing campaign to obtain spatially resolved spectroscopy over a broad wavelength range for large portions of the disks of 30 nearby spiral galaxies. In this thesis, the VENGA data is used to study the physical parameters that set the rate of star formation in the different environments present within galaxies in the local universe. / text

Polyethylene (PE) is produced in a huge scale globally and has plenty of desirable properties. It is used in coating, packaging, and artificial joint replacements. The growing need for high performance polyethylene led to the development of new catalysts, monomers and polymerizations. The synthesis of polymethylene (equivalent to polyethylene) by living polyhomologation opened the way to well-defined polymethylenes-based polymeric materials with controlled structure, molecular weight and narrow polydispersity. Such model polymers are substantial to study the structure-properties relationships. This research presents a new strategy based on the in situ formation of B-thexyl-silaboracyclic serving as initiating sites for the polyhomologation of dimethylsulfoxonium methylide. Combination with metal-free ring-opening polymerization (ROP) of ɛ-caprolactone (CL) and atom transfer radical polymerization (ATRP) of styrene led to three polymethylene-based 3-miktoarm stars copolymers PCL(PM-OH)2, Br-PCL(PM-OH)2 and PS(PM-OH)2.

Η οδηγία της Ευρωπαϊκής Ένωσης 2000/60 για τα νερά θέτει το πλαίσιο δράσης όλων των κρατών μελών της Ευρωπαϊκής Ένωσης για σωστή διαχείριση των υδάτινων πόρων τους προκειμένου να επιτευχθεί «καλή» οικολογική ποιότητα των επιφανειακών και υπόγειων υδάτων τους μέχρι το έτος 2015 και να αποτραπεί η περαιτέρω υποβάθμισή τους, με στόχο να διασφαλισθεί η υγιής λειτουργία των υδρόβιων οικοσυστημάτων. Προκειμένου να εκτιμηθεί η οικολογική ποιότητα των υδάτων των ποταμών Πείρου-Παραπείρου και Βουραϊκού, πραγματοποιήθηκαν δειγματοληψίες και εν συνεχεία χημικές, υδρομορφολογικές και βιολογικές αναλύσεις σε έντεκα θέσεις, επιλεγμένες με συγκεκριμένα κριτήρια κατά μήκος αυτών. Συγκεκριμένα, η συλλογή των δειγμάτων πραγματοποιήθηκε και τις τέσσερις εποχές του έτους 2006, ενώ στους ποταμούς Πείρο και Παραπείρο υλοποιήθηκε μια επιπλέον δειγματοληψία κατά την άνοιξη του έτους 2007. Η υδρομορφολογική ανάλυση πραγματοποιήθηκε ακολουθώντας τη μεθοδολογία River Habitat Survey, ενώ η βιολογική ανάλυση περιελάμβανε τη συλλογή δειγμάτων βενθικών μακροασπον-δύλων σύμφωνα με τη μεθοδολογία STAR AQEM. Παράλληλα, χρησιμοποιήθηκαν τεχνικές στατιστικής ανάλυσης προκειμένου να εντοπιστούν οι σημαντικότερες περιβαλλοντικές παράμετροι που επηρεάζουν τις βιοκοινότητες των μακροασπον-δύλων. Για τον υπολογισμό της οικολογικής ποιότητας εφαρμόστηκε η μεθοδολο-γία REFCOND προκειμένου να εκτιμηθεί αυτή με βάση την επιμέρους συμβολή των χημικών, υδρομορφολογικών και βιολογικών παραμέτρων στη διαμόρφωσή της. Σύμφωνα με τα αποτελέσματα της έρευνας περισσότερο του ήμισυ του μήκους των ποταμών Πείρου-Παραπείρου και των 3/5 του μήκους του ποταμού Βουραϊκού δεν ικανοποιούν τις απαιτήσεις της οδηγίας 2000/60/ΕΕ, εκτιμώμενη η οικολογική τους ποιότητα από «φτωχή» έως «μέτρια». Για τους Πείρο και Παραπείρο, η ποιοτική υποβάθμιση αποδίδεται σε αγροτικές και κτηνοτροφικές δραστηριότητες καθώς και στην παρουσία αστικών και βιομηχανικών αποβλήτων στις κατάντη θέσεις. Η αντίστοιχη του Βουραϊκού, εν μέρει οφείλεται σε αγροκτηνοτροφικές δραστηριότη-τες αλλά κυρίως στην παρουσία σημαντικών ποσοτήτων τυροκομικών αποβλήτων. Επιπλέον, τα ευρήματα στο συγκεκριμένο ποτάμι πιστοποιούν τον καθοριστικό ρόλο της παρόχθιας βλάστησης στην απορρύπανση των υδάτων των ποταμών. Κατόπιν των ανωτέρω κρίνεται επιτακτική η ανάγκη να ληφθούν τα ενδεδειγμένα μέτρα προστασίας των νερών των ποταμών από τα παντοειδή απόβλητα, προκειμένου να αναβαθμιστεί η ποιότητά τους με τελικό στόχο να ικανοποιηθούν οι απαιτήσεις της οδηγίας 2000/60 για διασφάλιση «καλής» οικολογικής ποιότητας μέχρι το έτος 2015. / One of the main issues of the EU Water Framework Directive 2000/60 is the achievement of “good” ecological status for the surface waters by the year 2015. All European countries are obliged to assess the ecological quality of their surface water bodies and classify them into a five-quality class system, with a final purpose to ensure “good” status for Europe’s water bodies and prevent their further deterioration. Eleven sites located in the rivers Peiros - Parapeiros and Vouraikos (Western Greece), were sampled seasonally and analyzed using physicochemical, hydromorphological and biological data, in order to classify the water quality according to the aforementioned directive. Physicochemical classification was performed using the Nutrient Classification System, while the habitat quality was estimated by applying the River Habitat Survey methodology. Biological sampling was performed by application of the STAR AQEM methodology, while the ecological classification was achieved by utilizing the “REFCOND guidance for the relative roles of the physicochemical, hydromorphological and biological quality elements”. Various multivariate techniques (Canonical Correspondence Analysis, Cluster Analysis and MDS) revealed the most important environmental factors that affected the macroinvertebrate communities. According to the results of the study, half length of the rivers Peiros-Parapeiros and the 3/5 of the river Vouraikos were found not to fullfil the demands of the WFD, with their quality being assessed from “moderate” to “poor”. Agriculture, urbanization and hydromorphological alteration were the main factors that contributed to the water quality degradation of the rivers Peiros and Parapeiros, while the presence of dairy wastewaters has been assessed as the main reason for the quality degradation of Vouraikos river. Moreover, the results of the study revealed the valuable role of the riparian vegetation in absorbing a large part of the incoming pollution. Finally, the results reveal the obligation for focused actions to be taken for monitoring and improvement of water quality, in order to meet the demands of the Water Framework Directive 2000/60/EU for “good” ecological quality, by the year 2015.

I investigate the emission properties of the molecular interstellar medium in protoplanetary disks and galaxy mergers, though focus largely on the latter topic. I utilize both numerical models as well as observations to relate the emission characteristics to physical models for the formation and evolution of gas giant planets and galaxies. The main results of this thesis follow. (1) Gas giant protoplanets may be detectable via self-absorption signatures in molecular emission lines with sufficiently high critical density. Given the spatial resolution of e.g. ALMA, gas giant planets in formation may be directly imageable. (2) Starburst and AGN feedback-driven winds in galaxies can leave imprints on the molecular line emission properties via morphological outflows and high velocity peaks in the emission line spectra. Methods for distinguishing between high velocity peaks driven by dynamics versus those driven by winds are discussed. (3) CO line widths on average trace the virial velocity of z ∼ 6 quasar host halos. Thus, if the earliest quasars formed in ∼1013 M ⊙ halos, they are predicted to have broad molecular line widths. Selection effects may exist which tend quasars selected for optical luminosity toward molecular line widths narrower than the slightline-dependent mean. (4) Using the SMT, I observe a roughly linear relation between infrared luminosity and CO (J=3-2) luminosity in local galaxies confirming the results of recently observed L(IR)-HCN (J=1-0) relations. Subsequent modeling shows that observed SFR-molecular line luminosity relations owe to the average fraction of subthermally excited gas in galaxies, and are simply reflective of the assumed Schmidt law governing the SFR.

High data rate applications are the trend in today's wireless technology. W-CDMA standard was designed to support such high data rates of up to 3.84 Mcps. The main purpose of this research was to analyze the feasibility of a fixed-point implementation of the W-CDMA downlink receiver algorithm on a general-purpose digital signal processor (StarCore SC140 by Motorola). The very large instruction word architecture of SC140 core is utilized to generate optimal implementation, to meet the real time timing requirements of the algorithm. The other main aim of this work was to study and evaluate the performance of the W-CDMA downlink structure with incorporated space-time transmit diversity. The effect of the channel estimation algorithm used was extensively studied too.

This study consists of a quantitative optical emission-line analysis of spectra from five blue compact galaxies (Zw 0855, Mrk 1267, II Zw 33, Tol 2 & Tol 3), as well as a qualitative analysis of spectra from two galactic H II regions (NGC 3603 & NGC 3576). It serves a two-fold purpose: first, to understand the CCD reduction, spectra extraction and different nebular analysis methods, together with their applications and limitations, preparatory to studies using the Southern African Large Telescope (SALT) and second, to extend current star formation related research to include extragalactic starburst galaxies. The observations were carried out using the 1.9m telescope (equipped with a grating spectroscope and CCD detector) of the South African Astronomical Observatory (SAAO), during the period 1 to 7 March 2005. The necessary CCD data reduction, spectra extraction, wavelength and flux calibration, Doppler shift as well as reddening correction procedures were performed before the emission lines were identified and measured. A full nebular analysis, including temperature, density, metallicity (oxygen abundance) and other chemical abundance determinations, was performed on the blue compact galaxies (BCGs). Two different nebular analysis packages viz. IRAF's nebular and SNAPwere used, with all the results well within the range of values expected for metal poor BCGs. Recommendations on the different methods and their applications are made. / Thesis (M.Sc. (Physics))--North-West University, Potchefstroom Campus, 2006.

Using a combination of optical and near-infrared photometry, we have studied both the resolved and integrated stellar populations for a sample of Virgo cluster galaxies spanning the full range of galaxian parameters. The derived stellar population properties are compared against galaxy structural and environmental measures to gauge the importance of these factors in establishing galaxy star formation histories and chemical evolution. Although galaxy colours do not uniquely probe a galaxy's star formation history, meaningful results may be obtained if considered in a relative sense. We find that colour profiles reflect variations in both stellar age and metallicity within galaxies. We also uncover systematic variations in colour gradients, and thus age/metallicity gradients, along the Hubble sequence, such that age and metallicity gradients become increasingly negative toward later Hubble types. However, only weak correlations exist between galaxies' stellar populations and their structure and environment. The correlations we find suggest that the star formation histories of gas-rich galaxies are strongly influenced by gas removal within the cluster, while their chemical evolution is due to a combination of stellar mass-dependent enrichment and outflow retention. The assembly of gas-poor giant galaxies is consistent with a hierarchical scenario wherein gas-rich mergers dominate by number. Gas-poor dwarfs differ from the giants, however, appearing as the product of environmentally-driven evolution. Spiral galaxies bridge the dwarf-giant gap, whereby merging and gas-stripping signatures are imprinted in their stars. Early-type spirals seem to have fallen into the cluster sooner than the later types, thereby ceasing star formation in their disks at earlier epochs. The bulges of both types, however, appear to have grown via merging. The nature of this merging (minor versus major) remains unknown. Irregular galaxies exhibit signs of a recent gravitational encounter that has redistributed both their stars and gas, the latter of which caused recent star formation. / Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2009-08-25 14:12:46.48

Argentina ha tenido, a lo largo de su historia, distintos procesos de crecimiento en los que las expansiones y las contracciones de su economía, en apariencia, parecen corresponder a distintos senderos de crecimiento. Si bien han sido analizados por diversos autores, el análisis se encuentra en el marco de historia económica o descripción de políticas públicas, salvo en Avila (1998), quien analiza el potencial de crecimiento económico argentino basándose en el cumplimiento de la hipótesis de convergencia; a pesar de ello, hasta la actualidad no se ha encarado un análisis empírico que contemple estos aspectos en los patrones de crecimiento de la economía Argentina. El objetivo de este trabajo es estudiar estos procesos de crecimiento dentro de un contexto de modelización no lineal en el cual se determine un umbral que delimite estas fases de crecimiento y, a partir de ello, poder caracterizar cada fase.

This document describes studies of two independent regions of the interstellar medium (ISM). These studies have the common element that both pertain to regions in our Galaxy that are known to be associated with present-day star formation. These studies aim to help us understand the ISM, star formation, and ultimately where we came from, since, after all, our star, the Sun, is itself the product of star formation 4.5 billion years ago. The first project measured the Zeeman Effect on the 21 cm H I absorption line in order to create a map of the line of sight magnetic fields near a star forming region called W3. From the map of the field, it was possible to create a three dimensional model of the magnetic field morphology. Also, calculating the various energies associated with W3 revealed that it is most likely in virial equilibrium, not expanding or contracting. The second project used an instrument on the Hubble Space Telescope (HST) to measure the abundance of iron in a neutral region near the Orion Nebula called Orion’s Veil. One of the goals of this project is to investigate whether solid dust grains can be destroyed by ionizing radiation by comparing the amount of solid iron in Orion’s Veil to the amount in the nearby ionized regions. By measuring the depletion of iron in the neutral Veil and comparing it to the depletion of iron the H+ regions of the Orion Nebula, it was possible to conclude that iron was not being released into the gas phase by ultraviolet photons. In addition, oscillator strengths for two Fe II transitions were measured.

Activity and fitness levels decline through the years from 30 to 60 years of age. Minimal research is available regarding functional assessment tools in this population. Reliable functional tools are needed to reintroduce individuals to appropriate physical activity levels following an injury and to maintain high levels of participation through their lifespan. The purposes of this study were multiple: 1) determine if three functional tests correspond with neuromotor fitness levels, 2) establish a model of functional tests, activity levels and descriptive data that distinguishes the most from the least fit, 3) describe expected mean functional test performances, and 4) demonstrate the reliability of the three functional tests in a sample of 30-60 year olds. 63 females and 38 males completed activity surveys, a neuromotor fitness test, the star excursion balance test (SEBT), the four square step test (FSST), and the Biering-Sorensen test of trunk extensor muscle endurance. Moderate to high reliability of the functional tests was determined with 29 subjects. The SEBT (r=.97), FSST (r=.88) and the Biering-Sorensen test (r=.64) were reliable. All functional tests were able to distinguish between the most fit and least fit with regards to the fitness tests. A model of the body mass index and the FSST predicted 25% of the variance in fitness level. Functional test means are reported by 10-year age groups and represent expected performance values.Health care professionals can use this information to compare their patients to this group of healthy individuals. This will allow them to have some idea of how well a person with an injury is performing relative to a healthy individual. Additionally the combination of a persons BMI plus their FSST gives the health care professional some information about an individual level of neuromuscular fitness so that the health care professional can guide their patients toward an appropriate level of physical activity after their injury or illness.