This work is a description of the Visible to near Infrared Spectrograph system for the CHARA array. The CHARA Array is a 6-telescope interferometer at the Mount Wilson Observatory in the mountains north of Pasadena, California. It combines the light from the 1-meter telescopes, and measures the visibility of the resulting interference fringes, which gives information about the source intensity distribution on the sky. The resolution of the instrument is proportional to the telescope separation, or baseline, divided by the wavelength. The VIS system operates in the 600-1000~nm wavelength range, a factor of 3 to 4 shorter than the standard operating wavelength at CHARA, 2.13 um. An introduction to interferometry is given, with a description of the CHARA Array. The effects of diffraction through the system combined with atmospheric turbulence are described, and the results of a computer model given. The VIS system design is described, and results of the first fringe data are presented, including system visibility and throughput estimates.

Thesis (M.A.B.S.)--International Christian Graduate University, School of Theology, 1987. / Abstract. Includes bibliographical references (leaves 107-112).

Thesis (M.A.B.S.)--International Christian Graduate University, School of Theology, 1987. / Abstract. Includes bibliographical references (leaves 107-112).

Thesis (Ph. D.)--University of Adelaide, Dept. of Botany, 1991. / Includes bibliographical references (leaves 197-209).

Thesis (D.Sc.) -- University of Adelaide, 1959. / "Adelaide, Dec. 1959." Includes bibliographical references. Also available in electronic format.

No description available.

No description available.

El crecimiento desmedido de especies como Chara contraria y Stuckenia pectinata dentro de los canales de riego, reduce la capacidad de transporte del agua en el sistema de riego del Valle Inferior del Río Colorado (VIRC). La presente tesis incluye el estudio de la capacidad invasora de C. contraria, diferentes opciones de control químico aplicables tanto en preemergencia como en postemergencia y el impacto del riego con agua tratada con productos químicos sobre distintos cultivos. C. contraria tiene la habilidad de colonizar rápidamente ambientes disturbados. Si bien, al momento de iniciarse la temporada de riego se registraron diferencias en promedio de 13.108 y 742 emergencias de talos m-2 en canales sin reestructurar y reestructurados respectivamente, se establece prontamente un stand monoespecífico en solo tres meses. El control químico en preemergencia se evaluó mediante la aplicación de diuron en canales de riego y diuron, metsulfuron, imazapir y ácido acético en sedimento seco colocado en acuarios. Solo los tratamientos de diuron en acuarios redujeron el crecimiento de C. contraria, aunque por efecto del lavado continuo de este producto por el agua de riego estos resultados no se repitieron en los canales. Entre los métodos de control evaluados en postemergencia en acuarios o canales, las aplicaciones de SCP a 0,625 y 1,25 ppm de cobre con tiempos de contacto (TC) mayores a 12h produjeron una reducción de la biomasa de C. contraria seguido de un rápido rebrote 10 días después del tratamiento. Se midió solo un 20% del cobre aplicado presente en el agua de riego 200m luego de la aplicación. El uso de diuron a 1ppm y TC de 8 -18 horas redujo la biomasa y evitó el rebrote de C. contraria y S. pectinata únicamente en acuarios. La aplicación de paraquat a 0,5ppm durante 18h de TC permitió reducir significativamente la biomasa de S. pectinata en acuarios y mostrar síntomas de marchitamiento de hojas en canales de riego, seguido de un rebrote 14 días después del tratamiento. El uso de 1,24 g de sulfato de amonio y cal L-1 durante 12h redujó la biomasa de C. contraria tanto en acuarios como en canales de riego. El secado de canales de riego durante los meses de verano por 7 a 12 días redujo en promedio un 80% la biomasa de C. contraria. Respecto al riego con agua tratada con SCP durante dos años, no se midió reducciones en el crecimiento ni acumulación de cobre en los tejidos, aunque si se detectó un aumento en el contenido de cobre disponible de los suelos irrigados. Mientras que los riegos con paraquat y SA y cal resultaron seguros para Trifolium pratense y Allium cepa a las dosis ensayadas para el control de C. contraria y S. pectinata, el riego con agua tratada con diuron produjo efectos fitotóxicos sobre estos mismos cultivos a partir de 0,016ppm. La información presentada en esta tesis deriva en el aporte de conocimiento aplicable con bases ecofisiológicas que contribuyen al manejo integrado de malezas acuáticas sumergidas en canales de riego. / The excessive growth of species such as Chara contraria and Stuckenia pectinata within irrigation canals reduces the water transport capacity of the irrigation system of the Lower Valley of the Colorado River (VIRC). This thesis includes the study of the invasive capacity of C. contraria, different chemical control options applicable both pre-emergence and post-emergence, and the impact of irrigation with water treated with chemical products on several crops. C. contraria has the ability to rapidly colonize disturbed environments. At the beginning of the irrigation season, although average differences of 13,108 and 742 thallus emergence per square meter were recorded in unrestructured and restructured canals, respectively, it quickly establishes in a monospecific stand in just three months. Chemical control in preemergence was evaluated through the application of diuron in irrigation canals and diuron, metsulfuron, imazapir and acetic acid in dry sediment placed in aquariums. Only the diuron treatments in aquarium reduced the growth of C. contraria, although due to the effect of the continuous washing of this product by the irrigation water, these results were not repeated in canals. Among the control methods evaluated postemergence in aquariums or canals, SCP applications at 0.625 and 1.25 ppm of copper with contact times (TC) greater than 12 hours produced a reduction in C. contraria biomass followed by a rapid regrowth 10 days after treatment. Only 20% of the applied copper present in the irrigation water 200m downstream of the application point was measured. The use of diuron at 1ppm and TC of 8 -18 hours reduced the biomass and prevented the regrowth of C. contraria and S. pectinata only in aquariums. Paraquat application at 0.5ppm during 18h of TC significantly reduced the biomass of S. pectinata in aquariums and showed slight symptoms of leaf wilting in irrigation canals, followed by regrowth 14 days after treatment. The use of 1.24 g de ammonium sulfate and lime per liter for 12 hours reduced the biomass of C. contraria both in aquariums an irrigation canals. Drying irrigation canals during the summer months for 7 to 12 days reduced the biomass of C. contraria by an average of 80%. Regarding irrigation with water treated with SCP for two years, no reductions in growth or accumulation of copper in the tissues were measured, although an increase in the available copper content of the irrigated soils was detected. While the irrigation with paraquat and SA and lime were secure for Trifolium pratense and Allium cepa at tested doses for the control of C. contraria and S. pectinata, the irrigation with water treated with diuron produced phytotoxic effects on these same crops from of only 0.016ppm. The information presented in this thesis derives in the amount of applicable knowledge with ecophysiological bases that contribute to the integrated management of submerged aquatic weeds in irrigation canals.

The aim of this study was to investigate whether the water chemistry in lake Lillsjön have changed significantly due to human impact of surrounding areas. Lake Lillsjön is located outside the central parts of Östersund. It is an important recrational area, and has great natural values, among other things it is habitat for several species of Chara stoneworts. Chara requires clear calcareous water, high pH, relatively low levels of nitrate-nitrogen and low phosphorus concentrations. Lake Lillsjöns is recepient for surface water from a nearby commercial and industrial area, as well as melt water from an adjecent snow dump. Compared to ten other Chara-lakes in the region, lake Lillsjön shows higher concentration of total phosphorus and higher water colour. The study concludes that the surface water from surrounding areas, as well as melting water from the snow dump, are the main sources of the higher concentration of total phosphorus in lake Lillsjön. While the colour of the incoming water only shows a weak difference compared to the water colour of the reference lakes, the source of the higher water colour cannot be established. The water of lake Lillsjön can not be consider a suitable habitat for Chara.

Submitted by dayse paz (daysepaz@hotmail.com) on 2016-04-06T11:50:24Z No. of bitstreams: 1 Disserta_o_Cristiane_Carvalho.pdf: 1091025 bytes, checksum: 71418d6d8927740542513191376e2254 (MD5) / Approved for entry into archive by cleuza maria medina dos santos (cleuzamai@yahoo.com.br) on 2016-05-09T14:26:19Z (GMT) No. of bitstreams: 1 Disserta_o_Cristiane_Carvalho.pdf: 1091025 bytes, checksum: 71418d6d8927740542513191376e2254 (MD5) / Made available in DSpace on 2016-05-09T14:26:19Z (GMT). No. of bitstreams: 1 Disserta_o_Cristiane_Carvalho.pdf: 1091025 bytes, checksum: 71418d6d8927740542513191376e2254 (MD5) Previous issue date: 2013 / Em lagos as macrófitas aquáticas são importantes fontes de matéria orgânica detrital, aumentam a complexidade do hábitat proporcionando vários nichos ecológicos a uma diversidade de espécies animais. Durante do processo de decomposição, a colonização dos detritos passa por uma sucessão ecológica entre fungos, bactérias e invertebrados, sendo seu papel fundamental para promover a circulação dos nutrientes. Assim, essa dissertação objetivou: (1) analisar os coeficientes de decomposição e a composição química dos detritos de duas macrófitas, a fim de verificar os efeitos dessas características sobre a biomassa fúngica e invertebrados; (2) analisar se o local de incubação das bolsas dos detritos influencia o recurso de hábitat e sobreposição espacial, interferindo na estrutura funcional da comunidade colonizadora. Para tanto foram realizados dois experimentos. Para o experimento 1 (setembro à dezembro de 2011), incubamos 24 bolsas de Potamogeton pectinatus e 24 de Chara zeylanica e retiradas em 1, 7, 20, 40, 60 e 80 dias. O material foi lavado, seco e triturado para análises químicas e determinação dos coeficientes de decomposição. A biomassa fúngica foi avaliada através do conteúdo de ergosterol. Para o experimento 2 (janeiro de 2012), foram incubadas 60 bolsas aleatoriamente divididas em 4 tratamentos, onde 15 bolsas contendo detritos de P. pectinatus foram incubadas em meio ao próprio estande (PP); 15 bolsas no estande de C. zeylanica (PC); 15 bolsas com detritos de C. zeylanica (CC) incubadas em meio ao seu estande e 15 no estande de P. pectinatus (CP), sendo retiradas em 5, 10 e 20 dias. Em ambos os estudos, os invertebrados foram classificados em grupos tróficos funcionais e determinadas a riqueza e abundância. As características químicas explicaram 59% da variação na abundância de invertebrados. A biomassa fúngica nos detritos não diferiu. A maior abundância e riqueza de invertebrados ocorreram nos detritos de P. pectinatus para o experimento 1 e nos detritos incubados em meio ao seu próprio estande (experimento 2). Houve diferença na perda de massa entre os tratamentos e entre detritos. A maior abundância na composição funcional foi de coletores - catadores e predadores, em ambos os estudos. Houve menor sobreposição espacial entre os grupos tróficos nos tratamentos em relação a PP. Nosso estudo demonstrou que os as características químicas e os coeficientes de decomposição interferem na colonização de invertebrados, relacionado ao tempo de incubação dos detritos. Além disso, o local de incubação afetou os coeficientes de decomposição e a estruturação da comunidade de invertebrados, relacionado à disponibilidade de hábitat oferecido pelos tratamentos. / In lakes the macrophytes are important sources of detrital organic matter, increase the complexity of providing various habitat niches to a variety of animal species. During the colonization process of decomposition of the waste undergoes an ecological succession among fungi, bacteria and invertebrates, and its key role in promoting the circulation of nutrients. Thus, this thesis aimed to: (1) analyze the decomposition rates and chemical composition of the detritus of two macrophytes in order to verify the effects of these characteristics on the fungal biomass and invertebrates, (2) examine if the site of the bags of incubation detritus influences the use and habitat overlap of space, affecting the functional structure of the settler community. Therefore, we performed two experiments. For experiment 1 (September to December, 2011), incubated 24 bags of Potamogeton pectinatus and 24 Chara zeylanica and withdrawn at 1, 7, 20, 40, 60 and 80 days. The material was washed, dried and ground for chemical analyzes and determination of the coefficients of decomposition. The fungal biomass was evaluated through the content of ergosterol. For experiment 2 (January, 2012), 60 bags were incubated randomly assigned to 4 treatments, where 15 bags of debris containing P. pectinatus were incubated in medium to own booth (PP); 15 scholarships in booth C. zeylanica (PC), 15 bags of detritus C. zeylanica (CC) incubated in the midst of its stand and 15 at the P. pectinatus (CP) and taken in 5, 10 and 20 days. In both studies, the invertebrates were classified into functional trophic groups and certain richness and abundance. The chemical characteristics explained 59% of variation in abundance of invertebrates. The fungal biomass in waste did not differ. The greatest abundance and diversity of invertebrates occurred in the debris of P. pectinatus for experiment 1 and incubated debris amidst its own booth (experiment 2). Was no difference in weight loss between treatments and among detritus. The highest abundance was in the functional composition of collectors - scavengers and predators, in both studies. There was a lower spatial overlap between trophic groups in treatments against PP. Our study demonstrated that the chemical characteristics and the coefficients of decomposition interfere with colonization of invertebrates, related to incubation time of detritus. Furthermore, the location of incubation affected the decomposition rates and invertebrate community structure, related to the availability of habitat offered by the treatments.