The interstellar matter in the Galaxy is concentrated in a thin layer close to the galactic plane, mostly in spiral arms. Most of the interstellar matter is in a form of atomic and molecular gas and only 1% of its mass is in a form of small (0.01 – 0.1 µm) dust grains which absorb and scatter the light of stars and cause the interstellar extinction. A part of interstellar gas and dust are in a diffuse form and fill the space with density which exponentially decreases with the distance from the galactic plane. However, in the spiral arms gigantic molecular clouds are present which play an outstanding role in the evolution of the Galaxy, since in them star forming processes take place. Molecular and dust clouds, young star clusters and associations and other star forming regions are concentrated in the Milky Way plane. However, due to gravitational and radiation interactions between the molecular clouds and the young massive stars, some fragments of spiral arms deviate from the galactic plane. One of such deviating branches from the Local (Orion) spiral arm is a huge elongated system of molecular and dust clouds located in the Cepheus constellation which is known as the Cepheus Flare. Most of the objects investigated in this dissertation belong to this branch of the Local spiral arm. The objects selected for the investigation are star forming regions in the vicinity of the reflection nebula NGC 7023, a group of dark clouds TGU 619, the young open cluster NGC 7129 and the... [to full text] / Paukščių tako Galaktikoje didžioji dalis tarpžvaigždinės medžiagos yra susitelkusi į ploną sluoksnį Galaktikos plokštumoje, daugiausiai spiralinėse vijose. Didžiąją dalį tarpžvaigždinės medžiagos sudaro atominės ir molekulinės dujos ir tik maždaug 1% masės yra mažos (0.01 – 0.1 µm) dydžio dulkelės, kurios sugeria ir išsklaido šviesą ir sukelia tarpžvaigždinės ekstinkcijos reiškinį. Spiralinėse vijose esantys molekuliniai debesys yra svarbūs Galaktikos evoliucijos procese, nes juose vyksta aktyvūs žvaigždžių formavimosi procesai. Molekuliniai ir dulkių debesys, jaunų žvaigždžių spiečiai ir asociacijos bei kitos žvaigždžių susidarymo sritys dažniausiai yra Galaktikos plokštumoje. Tačiau dėl gravitacinės ir radiacinės sąveikos tarp jaunų didelės masės žvaigždžių ir molekulinių debesų kai kuriose Paukščių Tako srityse žvaigždėdaros rajonai nukrypsta nuo Galaktikos plokštumos. Viename iš tokių rajonų Cefėjo žvaigždyno kryptimi dalis tarpžvaigždinių debesų ir žvaigždėdaros rajonų yra nukrypę nuo Galaktikos plokštumos link šiaurinio dangaus poliaus ir sudaro Paukščių Tako atšaką, literatūroje žinomą kaip Cepheus Flare. Dauguma šioje disertacijoje tyrinėjamų objektų priklauso šiai Cefėjo atšakai. Šio darbo tikslas yra Cefėjo žvaigždėdaros rajonų, žinomų kaip atspindžio ūkas NGC 7023, tamsiųjų debesų kompleksas TGU 619 ir jaunas spiečius NGC 7129 fotometrinis tyrimas, siekiant nustatyti šių objektų nuotolį ir tarpžvaigždinę ekstinkciją, jauno spiečiaus NGC 7129 ir... [toliau žr. visą tekstą]

Paukščių Tako Galaktikoje didžioji dalis tarpžvaigždinės medžiagos yra susitelkusi į ploną sluoksnį Galaktikos plokštumoje, daugiausiai spiralinėse vijose. Didžiąją dalį tarpžvaigždinės medžiagos sudaro atominės ir molekulinės dujos ir tik maždaug 1% masės yra mažos (0.01 – 0.1 µm) dydžio dulkelės, kurios sugeria ir išsklaido šviesą ir sukelia tarpžvaigždinės ekstinkcijos reiškinį. Spiralinėse vijose esantys molekuliniai debesys yra svarbūs Galaktikos evoliucijos procese, nes juose vyksta aktyvūs žvaigždžių formavimosi procesai. Molekuliniai ir dulkių debesys, jaunų žvaigždžių spiečiai ir asociacijos bei kitos žvaigždžių susidarymo sritys dažniausiai yra Galaktikos plokštumoje. Tačiau dėl gravitacinės ir radiacinės sąveikos tarp jaunų didelės masės žvaigždžių ir molekulinių debesų kai kuriose Paukščių Tako srityse žvaigždėdaros rajonai nukrypsta nuo Galaktikos plokštumos. Viename iš tokių rajonų Cefėjo žvaigždyno kryptimi dalis tarpžvaigždinių debesų ir žvaigždėdaros rajonų yra nukrypę nuo Galaktikos plokštumos link šiaurinio dangaus poliaus ir sudaro Paukščių Tako atšaką, literatūroje žinomą kaip Cepheus Flare. Dauguma šioje disertacijoje tyrinėjamų objektų priklauso šiai Cefėjo atšakai. Šio darbo tikslas yra Cefėjo žvaigždėdaros rajonų, žinomų kaip atspindžio ūkas NGC 7023, tamsiųjų debesų kompleksas TGU 619 ir jaunas spiečius NGC 7129 fotometrinis tyrimas, siekiant nustatyti šių objektų nuotolį ir tarpžvaigždinę ekstinkciją, jauno spiečiaus NGC 7129 ir... [toliau žr. visą tekstą] / The interstellar matter in the Galaxy is concentrated in a thin layer close to the galactic plane, mostly in spiral arms. Most of the interstellar matter is in a form of atomic and molecular gas and only 1% of its mass is in a form of small (0.01 – 0.1 µm) dust grains which absorb and scatter the light of stars and cause the interstellar extinction. A part of interstellar gas and dust are in a diffuse form and fill the space with density which exponentially decreases with the distance from the galactic plane. However, in the spiral arms gigantic molecular clouds are present which play an outstanding role in the evolution of the Galaxy, since in them star forming processes take place. Molecular and dust clouds, young star clusters and associations and other star forming regions are concentrated in the Milky Way plane. However, due to gravitational and radiation interactions between the molecular clouds and the young massive stars, some fragments of spiral arms deviate from the galactic plane. One of such deviating branches from the Local (Orion) spiral arm is a huge elongated system of molecular and dust clouds located in the Cepheus constellation which is known as the Cepheus Flare. Most of the objects investigated in this dissertation belong to this branch of the Local spiral arm. The objects selected for the investigation are star forming regions in the vicinity of the reflection nebula NGC 7023, a group of dark clouds TGU 619, the young open cluster NGC 7129 and the... [to full text]

Made available in DSpace on 2016-08-15T20:28:00Z (GMT). No. of bitstreams: 1 FranciscoCL_DISSERT.pdf: 1013967 bytes, checksum: a197e5825cf00fce85fcefac99ddcfcf (MD5) Previous issue date: 2015-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Trypanosomiasis by Trypanossoma vivax is exotic disease of African origin increasingly common in Brazil, where reports of outbreaks in ruminants in the semiarid northeast are associated with high mortality, decrease in productive performance and economic losses. This study aimed to evaluate the clinical, epidemiological, production and quality of milk during natural infection by T. vivax in dairy cattle in western Rio Grande do Norte and verified the effect of infection on performance in experimentally infected dairy goats. This is the first Trypanosomiasis outbreak of T. vivax in dairy cattle herd occurred in properties located in the rural municipality of Mossoró-RN. Found 42 animals with trypomastigotes of T. vivax by smear of buffy coat in 467 cattle crossbred dairy breeds. High fever, anemia, decreased milk production, unilateral and bilateral tearing were the most frequent clinical signs. All cows with the parasite had sudden drop in milk production, and the physicochemical characteristics changed values, where the averages of lactose, fat, protein and density milk group with parasite was different from the healthy group. Influence of infection by T. vivax on the lactation curve behavior and the quality of milk in experimentally infected dairy goats was studied using 20 Saanen goats second lactation divided in two groups: the infected group, consisting of ten goats infected intravenously with approximately 1.25 x 105 trypomastigotes of T. vivax and ten animals were used as control. Milk production was measured every day for 152 days, by means of hand milking and weighing of the milk. To analyze the lactation curve parameters was used Wood model. Infected goats showed high parasitemy and hyperthermia addition to significant hematocrit reduction, serum total protein, albumin, glucose, cholesterol and increase in the urea concentration. Wood model showed that there was difference (P <0.05) to increase the rate values of milk production up to the peak, decline rate of milk production after the peak, milk production day at the peak, maximum milk production at peak and persistency of lactation in goats experimentally infected group compared goats in the control group, and physico-chemical characteristics of milk as fat, nonfat dry stratum, density and protein decreased significantly (P <0.05) in the group infected goats compared goats in the control group / A tripanossomíase por Trypanossoma vivax é uma enfermidade exótica, de origem africana, cada vez mais frequente no território brasileiro, cujos relatos de surtos em ruminantes no semiárido nordestino estão associados à alta mortalidade, diminuição no desempenho produtivo e perdas econômicas. Este trabalho buscou avaliar os aspectos clínicos, epidemiológicos, produtivos e qualidade do leite durante infecção natural por T. vivax em bovinos leiteiros na região oeste do Rio grande do Norte e verificou o efeito da infecção sobre o desempenho produtivo em cabras leiteiras experimentalmente infectadas. Trata-se do primeiro surto de Tripanossomíase por T. vivax em rebanho bovino leiteiro ocorrido em propriedades localizadas na zona rural do município de Mossoró-RN. Foram encontradas 42 tripomastigotas de T. vivax pelo esfregaço da camada leucocitária em 467 bovinos de raças mestiças leiteiras. Febre alta, anemia, queda na produção de leite, lacrimejamento uni ou bilateral foram os sinais clínicos mais frequentes. Todas as vacas parasitadas tiveram queda brusca na produção de leite, e as características físico-químicas valores alterados, onde as médias dos teores de lactose, gordura, proteína e densidade do leite do grupo parasitado se mostrou diferente dos sadios. A influência da infecção por T. vivax sobre o comportamento da curva de lactação e a qualidade do leite em cabras leiteiras experimentalmente infectadas foi estudada utilizando 20 cabras da raça Saanen de segunda lactação divididos em dois grupos experimentais: o grupo infectado, constituído por dez cabras infectadas por via intravenosa com aproximadamente 1,25 x 105 tripomastigotas de T. vivax e outros dez animais foram destinados ao grupo controle. A produção do leite foi aferida diariamente durante 152 dias, mediante ordenha manual e pesagem do leite. Para análise dos parâmetros da curva de lactação, utilizou-se o modelo Wood. As cabras infectadas apresentaram altas parasitemias e hipertermia, além de redução significativa do hematócrito e dos níveis séricos de proteína total, albumina, glicose, colesterol e aumento na concentração de ureia. O modelo Wood mostrou que ocorreu diferença (P<0,05) para os valores da taxa de acréscimo da produção de leite até o pico, taxa de declínio de produção de leite após o pico, dia de produção de leite no pico, produção máxima de leite no pico e persistência da lactação no grupo de cabras infectadas experimentalmente em relação as cabras do grupo controle, e as características físico-química do leite relacionadas aos teores de gordura, ESD, densidade e proteína diminuíram significativamente (P <0,05) nas cabras do grupo infectado em relação as cabras do grupo controle

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Submitted by (edna.saturno@ufrpe.br) on 2017-05-18T15:05:36Z No. of bitstreams: 1 Wellington Samay de Melo.pdf: 950858 bytes, checksum: 66714039b99a8f1b113f9673e24c020c (MD5) / Made available in DSpace on 2017-05-18T15:05:36Z (GMT). No. of bitstreams: 1 Wellington Samay de Melo.pdf: 950858 bytes, checksum: 66714039b99a8f1b113f9673e24c020c (MD5) Previous issue date: 2009-02-27 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / This study evaluated the intake and apparent digestibility of nutrients; production and chemical composition of milk; the additional cost of the supplements; microbial synthesis of nitrogen and rude protein, and their efficiencies; plasma levels of glucose and urea; and excretions of urea in crossbred dairy cows on pasture during the dry-water transition. It was used eight cows (Gyr/Holstein/Brown Swiss) without defined genetic composition, average production of 15 kg/day and average live weight of 500 kg; distributed in two latin squares. The experimental period lasted 60 days (four sub-periods of 15 days). The following treatments were offered: corn silage + concentrate; forage cactus + concentrate, corn silage + soybean meal, and forage cactus + soybean meal. The concentrate was elaborated with 27.75% of rude protein. The pasture area used was 53 ha, with Brachiaria decumbens sp.Predomination. The supplements promote addictive effect on pasture nutrients when they contained corn silage andsubstitutive effect when they contained forage cactus. The supplements containing forage cactus promotes smaller intake of neutral detergent fiber and larger of non-fiber carbohydrate. The apparent digestibility of the neutral detergent fiber and non-fiber carbohydrate differ from the use of forage cactus or corn silage. The use of the supplements containing concentrate elevates the milk production up to 17 kg/day in the drought-waters transition period. The supplements can be used without any damage to milk composition. Economical results suggest flexibilization of the supplements. The use of the supplements balances glucose and urea plasmatic levels, as well as the ureaexcretion in urine and milk. There was similarity in the supplements nitrogen metabolism, consequently, nitrogen and of rude protein microbial synthesis they were similar. The efficiency of synthesis of microbial rude protein in cows receiving supplements on grazing in the drought-waters transition period shows an average of 146,20 g MicRP/Kg TDN. / Objetivou-se avaliar o consumo e a digestibilidade aparente dos nutrientes; produção e composição química do leite; economicidade das dietas suplementares; excreções de bases purinas, as sínteses microbianas de nitrogênio e proteína bruta, e suas eficiências; os níveis plasmáticos de glicose e uréia; assim como as excreções de uréia de vacas leiteiras mestiças suplementadas a pasto no período de transição seca-águas. Utilizaram-se oito vacas mestiças tricoss (Gir/Holandês/Pardo Suíço) sem composição genética definida, produção média de 15 kg/dia e peso vivo médio de 500 kg; distribuídas em dois quadrados latinos. O período experimental durou 60 dias (quatro sub-períodos de 15 dias). Os seguintes suplementos foram ofertados: silagem de milho + concentrado; palma + concentrado; silagem de milho + farelo de soja; e = palma + farelo de soja. O concentrado foi elaborado com teor de 27,75% de proteína bruta. A área da pastagem utilizada foi de 53 ha, com predominância de capim Brachiaria decumbens sp. Os suplementos promovem efeito aditivo aos nutrientes do pasto quando continham silagem de milho e efeito substitutivo quando continham palma forrageira. Os suplementos contendo palma forrageira promovem menores consumos de fibra em detergente neutro e maiores de carboidratos não-fibrosos. As digestibilidades aparentes de fibra em detergente neutro e carboidratos não-fibrosos diferem quando da utilização de palma forrageira ou silagem de milho. O uso dos suplementos contendo concentrado eleva a produção de leite acima de 17 kg/dia no período de transição seca-águas. Os suplementos testados podem ser seguramente utilizados sem qualquerprejuízo à composição do leite. Os resultados econômicos são sugestivos à flexibilização do uso dos suplementos. Os suplementos utilizados equilibram os níveis plasmáticos de glicose e uréia, assim como a excreção de uréia na urina e no leite. A semelhança nas excreções de bases purinas pelos animais proporciona sínteses de nitrogênio e de proteína bruta microbiana semelhantes. A eficiência de síntese de proteína bruta microbiana de vacas suplementadas a pasto no período de transição seca-águas apresenta média geral de 146,20 g PBMic/Kg NDT.

Neste trabalho, é proposto um método de separação e determinação das vitaminas hidrossolúveis utilizando-se eletroforese capilar na modalidade cromatografia eletrocinética micelar (MEKC). MEKC pode ser empregada para separar ambas moléculas carregadas ou neutras, individual ou simultaneamente. O método desenvolvido consistiu-se de 20 mmol L-1 de tetraborato de sódio (TBS), 20 mmol L-1 de dodecilsulfato de sódio (SDS) e metanol 15% (v/v). As soluções foram introduzidas no sistema eletroforético sob pressão de 0,5 psi por 3 s. A separação foi conduzida em um capilar de sílica fundida de 50 cm, sob potencial de 20 kV, à temperatura de 22ºC e monitorada em 200, 254 e 270 nm. O método analítico apresentou-se seletivo com separação em linha de base, preciso com áreas relativas no intervalo de 1,0 a 11%, apresentou baixos limites de detecção (entre 1,6 e 27,7 &#181;mol L-1) e quantificação (entre 5,0 e 92,2 &#181;mol L-1), além de ser simples e com alta frequência analítica, possibilitando separar as nove vitaminas hidrossolúveis em 15,50 min. Ele foi aplicado em amostra de farinha láctea, na qual foi possível determinar 4 vitaminas (B3, B5, B6 e C). Um método de separação para as vitaminas lipossolúveis, utilizando cromatografia a líquido, também foi proposto. Foi possível obter a separação em linha de base de sete vitaminas desta classe. A validação e a aplicação do método ainda devem ser investigadas. / In this paper, we propose a method for separation and determination of water-soluble vitamins using capillary electrophoresis method in micellar electrokinetic chromatography (MEKC). MEKC can be employed to separate both charged end neutral molecules, individually or simultaneously .The method consisted in 20 mmol L-1 sodium tetraborate (TBS), 20 mmol L-1 sodium dodecyl sulfate (SDS) and 15% methanol (v / v). The solutions were introduced into the electrophoretic system under pressure of 0.5 psi for 3 seconds. The separation was performed in a fused silica capillary of 50 cm under potential of 20 kV at a temperature of 22 ° C and monitored at 200, 254 and 270 nm. The analytical method was presented with selective separation line basis with precise relative areas in the range of 1.0 to 11%, showed low detection (1.6 to 27.7 &#181;mol L-1) and quantification (from 5.0 to 92.2 &#181;mol L-1) limits, besides being simple and high sampling rate, allowing to separate nine water-soluble vitamins in 15.50 min. The method was applied to a sample of milky flour, which it was possible to determine 4 vitamins (B3, B5, B6 e C). A method for separating soluble vitamins using liquid chromatography has also been proposed. It was possible to obtain a baseline separation of seven vitamins this class. The validation and application of the method must still be investigated.

Este trabalho refere-se ao estudo de um canal reverso de distribuição de produtos lácteos. O objetivo foi verificar a estrutura do canal reverso de produtos lácteos não comercializados e como ocorre o seu gerenciamento. Entendem-se como produtos não comercializados, alimentos lácteos não vendidos pelos atacadistas e varejistas, cujos prazos de validade ainda não expiraram. Especificamente, buscou-se identificar o design do canal reverso desses alimentos e quais as funções de cada membro participante de seu canal de distribuição; investigar como é feito o gerenciamento em relação à coordenação, às operações comerciais e à logística reversa do canal em foco, além de identificar o portfólio de produtos em questão. A relevância do estudo está na importância crescente dos canais de distribuição, os quais têm se desenvolvido e inovado tanto por meio de seus diferentes formatos, quanto pela agregação de valor aos seus membros, como estratégia competitiva de mercado. Este estudo objetivou conhecer o caminho contrário percorrido pelos produtos em questão no canal de distribuição, então chamado reverso, em referência às movimentações de materiais no sentido inverso ao da cadeia de distribuição. Atualmente no Brasil descartam-se toneladas de produtos alimentares. Sendo assim, por meio desta pesquisa, buscou-se verificar se há uma estrutura reversa gerenciada para o descarte e/ou reaproveitamento de produtos não comercializados. Este trabalho constitui-se em uma pesquisa exploratória e qualitativa, sendo realizado estudo de casos, dentre os quais foram pesquisados uma indústria, três distribuidores, dois atacadistas e seis supermercados. Como instrumentos de coleta de dados foram utilizadas entrevistas em profundidade. O principal resultado identificado neste estudo demonstra que as empresas participantes do canal de distribuição de produtos lácteos não possuem uma estrutura definida para o gerenciamento do canal reverso, ou seja, estas não têm um modelo do caminho contrário percorrido pelos produtos em questão no canal de distribuição, apesar do interesse demonstrado pelas empresas. / This work refers to the study of a reverse channel distribution of diary products. The objective was to verify the structure of the reverse channel of diary products which were not commercialized and how their management occurs. It is understood as not commercialized products diary foods which were not commercialized by the wholesalers and retailers and which the validity data has not expired yet. This work tried to identify specifically the reverse channel design of these foods and the function of each participant member of the channel of distribution; to investigate how management is made regarding the coordination, the commercial transactions and logistic channel reverse in focus, and also identify the portfolio of products in question. The relevance of the study is due to the increasing importance of the distribution channels, which have developed and innovated by means of different formats, as well as for value aggregation to its members, as a competitive market strategy. The objective of this study is to know the contrary path of the products in question in the distribution channel, which is called reverse, in reference to the movements of materials in the inverse direction to the one of the distribution chain. Currently in Brazil tons of alimentary products are disposed. Therefore, by means of this research, the intention is to verify if there is a reverse management structure for the disposal and/or reuse of not commercialized products. This work consists in an exploratory and qualitative research, being carried out through case studies, which researched an industry, three distributors, two wholesalers and six supermarkets. As instruments of data collection the procedure used was in depth interviews. The main result identified in this study was that the participating companies of the distribution channel of diary products do not have a defined structure for managing the reverse channel, that is, there is no model of the contrary path of the products in question in the distribution channel, even though the companies show interest.

Multiple coherent supernova explosions (SNe) in an OB association can produce a strong shock that moves through the interstellar medium (ISM). These shocks fronts carve out hot and tenuous regions in the ISM known as superbubbles. The density contour plot at three different times (0.5 Myr (left panel), 4 Myr (middle panel), 9.5 Myr (right panel)) showing different stages of superbubble evolution for n0 = 0.5 cm−3, z0 = 300 pc, and for NOB = 104. This density contour plot is produced using ZEUS-MP 2D hydrodynamic simulation with a resolution of 512 × 512 with a logarithmic grid extending from 2 pc to 2.5 kpc. For a detailed description of this figure, see Roy et. al., 2015. The evolution of a superbubble is marked by different phases, as it moves through the ISM. Consider an OB association at the center of a disk galaxy. Initially the distance of the shock front is much smaller than the disk scale height. The superbubble shell sweeps up the ISM material, and once the amount of swept up material becomes comparable to the ejected material during SNe, the superbubble enters a self-similar phase (analogous to the Sedov-Taylor phase of individual SNe). As the superbubble shell sweeps up material, its velocity decreases, and thus the corresponding post-shock temperature drops. At a temperature of ∼ 2 × 105 K (where the cooling function peaks), the superbubble shell becomes radiative and starts losing energy via radiative cooling. This radiative phase is shown in the left panel of Figure 1. The superbubble shell starts fragmenting into clumps and channels due to Rayleigh-Taylor instabilities (RTI) (which is seeded by the thermal instability; for details see Roy et. al., 2013) when the superbubble shell crosses a few times the scale height. This is represented in the middle panel of the same figure. At a much later epoch, RTI has a strong effect on the shell fragmentation and the top of the bubble is completely blown off (the right panel). In the first chapter of the thesis (reported in Sharma et. al., 2014), we show using ZEUS-MP hydrodynamic simulations that an isolated supernova loses almost all its mechanical energy within a Myr whereas superbubbles can retain up to ∼ 40% of the input energy over the lifetime of the starcluster (∼ few tens of Myr), consistent with the analytic estimate of the second chapter. We also compare different recipes (constant luminosity driven model (LD model), kinetic energy driven model (KE model) to implement SNe feedback in numerical simulations. We determine the constraints on the injection radius (within which the SNe input energy is injected) so that the supernova explosion energy realistically couples to the interstellar medium (ISM). We show that all models produce similar results if the SNe energy is injected within a very small volume ( typically 1–2 pc for typical disk parameters). The second chapter concentrates on the conditions for galactic disks to produce superbubbles which can give rise to galactic winds after breaking out of the disk. The Kompaneets formalism provides an analytic expression for the adiabatic evolution of a superbubble. In our calculation, we include radiative cooling, and implement the supernova explosion energy in terms of constant luminosity through out the life-time of the OB stars in an exponentially stratified medium (Roy et. al., 2013). We use hydrodynamic simulations (ZEUS-MP) to determine the evolution of the superbubble shell. The main result of our calculation is a clear demarcation between the energy scales of sources causing two different astrophysical phenomenon: (i) An energy injection rate of ∼ 10−4 erg cm−2 s−1 (corresponding Mach number ∼ 2–3, produced by large OB associations) is relevant for disk galaxies with synchrotron emitting gas in the extra-planar regions. (ii) A larger energy injection scale ∼ 10−3 erg cm−2 s−1, or equivalently a surface density of star formation rate ∼ 0.1 M⊙ yr−1 kpc−2 corresponding to superbubbles with high Mach number (∼ 5–10) produces galactic-scale superwinds (requires superstar clusters to evolve coherently in space and time). The stronger energy injection case also satisfies the requirements to create and maintain a multiphase halo (matches with observations). Roy et. al., 2013 also points out that Rayleigh-Taylor instability (RTI) plays an important role in the fragmentation of superbubble shell when the shell reaches a distance approximately 2–3 times the scale-height; and before the initiation of RTI, thermal instability helps to corrugate the shell and seed the RTI. Another important finding of this chapter is the analytic estimation of the energetics of superbubble shell. The shell retains almost ∼ 30% of the thermal energy after the radiative losses at the end of the lifetime of OB associations. The third chapter considers the escape of hydrogen ionizing (Lyc) photons arising from the central OB-association that depends on the superbubble shell dynamics. The escape fraction of Lyc photons is expected to decrease at an initial stage (when the superbubble is buried in the disk) as the dense shell absorbs most of the ionizing photons, whereas the subsequently formed channels (created by RTI and thermal instabilities) in the shell creates optically thin pathways at a later time (∼ 2–3 dynamical times) which help the ionizing photons to escape. We determine an escape fraction (fesc) of Lyc photons of ∼ 10 ± 5% from typical disk galaxies (within 0 ≤ z (redshift) ≤ 2) with a weak variation with disk masses (reported in Roy et. al., 2015). This is consistent with observations of local galaxies as well as constraints from the epoch of reionization. Our work connects the fesc with the fundamental disk parameters (mid-plane density (n0), scale-height (z0)) via a relation that fescαn20z03 (with a ≈ 2.2) is a constant. In the fourth chapter, we have considered a simple model of molecule formation in the superbubble shells produced in starburst nuclei. We determine the threshold conditions on the disk parameters (gas density and scale height) for the formation of molecules in superbubble shells breaking out of disk galaxies. This threshold condition implies a gas surface density of ≥ 2000 M⊙ pc−2, which translates to a SFR of ≥ 5 M⊙ yr−1 within the nuclear region of radius ∼ 100 pc, consistent with the observed SFR of galaxies hosting molecular outflows. Consideration of molecule formation in these expanding superbubble shells predicts molecular outflows with velocities ∼ 30–40 km s−1 at distances ∼ 100–200 pc with a molecular mass ∼ 106–107 M⊙, which tally with the recent ALMA observations of NGC 253. We also consider different combinations of disk parameters and predict velocities of molecule bearing shells in the range of ∼ 30–100 km s−1 with length scales of ≥ 100 pc, in rough agreement with the observations of molecules in NGC 3628 and M82 (Roy et. al., 2016, submitted to MNRAS).

More than half a decade of X-ray astronomy with various balloon borne and space orbiting X-ray instruments, have led to discoveries and detailed studies of X-ray binaries. An important property of X-ray binaries is intensity variations of different magnitudes in a wide range of timescales from milliseconds (quasi-periodic oscillations, millisecond pulsations), to a few weeks (orbital and super-orbital modulations) or longer (outbursts etc). In this thesis, different types of variabilities of X-ray binaries are considered in X-ray binary population studies and to investigate certain aspects of some individual systems. In Chapter 1, we provide an introduction to various types of variabilities seen in different classes of X-ray binaries. We mention in detail the various periodic and aperiodic variabilities seen in X-ray binaries. In Chapter 2, we describe, in some detail, the various X-ray all sky monitors and X-ray observatories, data from which has been utilized in the work carried out in this thesis. We also describe the various data analysis techniques that we have used. The rest of the thesis is divided into two major sections: Variability studies of indi-vidual systems and X-ray binary population studies Variability studies of individual systems In Chapter 3, we report results from an investigation of energy resolved orbital in-tensity pro les and from exhaustive orbital phase resolved spectroscopic measurements of GX 301{2 with MAXI{GSC . The orbital variation of the spectral parameters, es-pecially the relation between the equivalent width of Fe line and the column density of absorbing matter are then utilized to examine the models for the mode of accretion onto the neutron star in GX 301{2: circumstellar disk model by Pravdo & Ghosh (2001), and the accretion stream model by Leahy & Kostka (2008). A very large equivalent width of the iron line along with a small value of the column density in the orbital phase range 0.10-0.30 after the periastron passage indicates an asymmetry in the distribution of the matter around the neutron star, strongly favoring the accretion stream model by Leahy & Kostka (2008). Presence of an eclipse in an X-ray binary can be useful in determining orbital param-eters like inclination and in estimating the orbital evolution by eclipse timing method, which is reported in Chapter 4. For the HMXB system IGR J16393{4643, we found a short eclipse in the Swift{BAT light-curve and utilized it to constrain the orbital in-clination of the system. We have also studied, for the rst time, broad-band pulsation and spectral characteristic of the system with a Suzaku observation, showing sub-orbital intensity variations. For another eclipsing and non-pulsing HMXB 4U 1700{37, the orbital evolution is studied using mid-eclipse times from observations with narrow eld instruments as well as from long term light-curves of X-ray all sky monitors. The orbital period decay rate is estimated to be 5 10 7 /yr, an order slower than a previous measurement by Rubin et al.(1996). Since no pulsations are detected in this system, it is difficult to estimate its orbital parameters, especially its eccentricity. Using mid-eclipse times from 10 years of Swift{BAT data, we have independently constrained the eccentricity of the binary system. X-ray binary population studies In Chapter 5, we report results from an analysis of the 16 years light-curves of X-ray binaries in 2-10 keV energy band of RXTE{ASM , used to construct the differential and integral probability distributions of count-rates. These distributions are then employed to construct multiple snapshots of X-ray binary luminosity functions of the Milky Way instead of averaging the luminosities, an improvement over previous analysis by Grimm et al. (2002). We found that the averaged luminosities of highly variable X-ray binaries do not represent their true positions in XLFs and the variability of X-ray binaries do indeed signi cantly affect the luminosity functions. In Chapter 6, the measurements of the averaged spectra of X-ray binaries using MAXI{GSC data are reported and are used for constructing the composite X-ray spec-trum. These composite X-ray binary spectra are useful in estimating the contribution of X-ray binaries in extra-galactic SEDs constructed from the simultaneous Chandra / XMM{Newton and NuSTAR observations of these galaxies. These SEDs will also serve as a useful input in estimating the contribution of X-ray binary heating at high redshift IGM during the Epoch of Re-ionization. In Chapter 7, we summarize the main conclusions of the work carried out in this thesis and discuss some future prospects related to this thesis.

L'étude de la composition chimique et de la cinématique des étoiles de la Voie Lactée est essentielle afin de comprendre comment les grandes structures de notre Galaxie se sont formées. Les étoiles de faible masse gardent en mémoire dans leur atmosphère la composition chimique du milieu interstellaire dans lequel elles sont nées, et leur cinématique est essentielle afin de caractériser les différentes populations stellaires. Dans cette thèse, nous étudions le disque galactique, composante majeure de notre Galaxie. Dans le cadre de la mission spatiale Gaia, nous avons développé une procédure automatique de mesure d'abondances chimiques, GAUGUIN, utilisée dans le cadre du Gaia-ESO Survey GES (abondances chimiques d'éléments alpha et du pic du fer pour 10000 étoiles) et du projet AMBRE (abondances de lithium pour 7300 étoiles). GAUGUIN va être intégré au pipeline d'analyse des spectres RVS de Gaia. Nous avons étudié l'évolution des dispersions des vitesses dans le disque galactique en fonction du [Mg/Fe], utilisé comme proxy de l'âge. A partir de 6800 étoiles de GES, nous avons détecté la présence d'étoiles du disque épais cinématiquement froides mais avec des valeurs élevées du rapport [Mg/Fe], donc possiblement âgées. Dans le contexte d'un milieu turbulent, nous discutons la présence de ces étoiles dans le cadre des différents modèles de formation du disque galactique. Nous avons également montré que l'abondance du lithium dans le disque montre une croissance avec la métallicité sur le domaine -1<[M/H]<+0 dex et décroît pour les métallicités super-solaires. Enfin, le disque mince et le disque épais seraient caractérisés par des évolutions chimiques différentes en abondance de lithium. / Studying both the chemical composition and kinematics of Milky Way stars is essential to understand how big structures of our Galaxy are formed. Indeed, low-mass stars retain in their photosphere the chemical composition of the interstellar medium is which they were born. Additionally, the kinematics are essential to characterize stellar populations. In this thesis, we focus on the galactic disc, a major component of the Milky Way. In the context of the Gaia mission, we have developed an automatic procedure GAUGUIN, devoted to deriving chemical abundances. We first applied our method to the Gaia-ESO Survey (GES) data to derive alpha and iron-peak chemical abundances for 10000 stars. We then derived lithium abundances for 7300 stars from the AMBRE project. GAUGUIN is well adapted to massive spectroscopic surveys, both in terms of computation time and accuracy. GAUGUIN will be soon integrated into the RVS DPAC analysis pipeline of the Gaia mission. We studied the velocity dispersions in the galactic disc as a function of the [Mg/Fe] ratio, used as an age proxy. Thanks to 6800 GES stars, we detected thick disc stars with cool kinematics and high [Mg/Fe] ratio, so presumably old. In the generally turbulent context of the primitive galactic disc, this thesis places these results in the framework of the different disc formation and evolution scenarios. We also showed that the lithium abundance in the galactic disc increases as a function of the metallicity in the domain -1<[M/H]+0 dex and decreases at super-solar metallicities. Finally, the thin and the thick discs could be characterized by different lithium abundance evolutions.