Cosmological quintessence accretion onto primordial black holes : conditions for their growth to the supermassive scale

In this work we revisit the growth of small primordial black holes (PBHs) immersed in a quintessential field and/or radiation to the supermassive black hole (SMBHs) scale. We show the difficulties of scenarios in which such huge growth is possible. For that purpose we evaluated analytical solutions of the differential equations (describing mass evolution) and point out the strong fine tuning for that conclusions. The timescale for growth in a model with a constant quintessence flux is calculated and we show that it is much bigger than the Hubble time.The fractional gain of the mass is further evaluated in other forms, including quintessence and/or radiation. We calculate the cosmological density $\Omega$ due to quintessence necessary to grow BHs to the supermassive range and show it to be much bigger than one. We also describe the set of complete equations analyzing the evolution of the BH+quintessence universe, showing some interesting effects such the quenching of the BH mass growth due to the evolution of the background energy. Additional constraints obtained by using the Holographic Bound are also described. The general equilibrium conditions for evaporating/accreting black holes evolving in a quintessence/radiation universe are discussed in the Appendix.Comment: 21 pp., 2 Figures, To appear in IJMP

Reavaliaçao da evoluçao tectono-magmática do Graben de Jaibaras (nordeste do Brasil)

The Jaibaras Trough (GJ), located in the Northeast Brazil, represents the most important, prominent and extensive exposure of Early Phanerozoic sedimentary sequences in a wide Brasiliano-age area, including Borborema Province and West Africa (mainly Nigerian Shield). The main basin feature is delineated by major brittle normal faults, resulted from reactivation of mylonite shear zones inside the so-called Transbrasiliano Lineament. The Jaibaras rift evolution is not only partially constrained by the stratigraphic record of the basin in fill, which is characterized by basal fault-scarp-related paraconglomerates followed laterally and vertically by fluvial-lacustrine sandstones which are interbeded with reddish shale, but also by the petrological signatura rift-related magmatic activity. Magmatic evolutive aspects of GJ comprises basically four temporal and spatially separated igneous steps. The earlier phase involved the Coreaú dike swa rm, which is Vendian in age, representing the initial tectonic pulse of the rift opening. With the continued breakup, reactivation of deeper shear zones gave rise to the emplacement of Mucambo Pluton during Early Cambrian times, preceding the main rift infill. The basin sedimentation was accomppanied by huge volume of volcanism, most of it occurring as flood basalts, dikes and sills in shape. The Meruoca Pluton is the last basin-related igneous manifestation during Upper Cambrian. Sequential stratigraphic interactions between sediments and magmatic events are perfectly constrained at the expense of thermal-structural features such as contact aureoles, faulted contacts, abuting and cross-cuting. Local and regional stress-field during GJ formation were obtained by using the configuration of magmatic bodies and their interplays with host-rocks. The physical-chemical characteristics of igneous activity also allows us to discuss the simultaneous thermal crustal-mantelic response due to magmagenesis and the emplacement processes. Initially, during the GJ nucleation, a NW-SE extensional pulse is recorded by the intrusion of the Coreaú Dike Swa rm, following hydraulic fracturing model. Following the same extensional stress-field, the studied plutons were emplaced by using nort h west-trending preexisting basement structures in areas of releasing bends where their feeder dikes were intruded. We hypothesize that two distinctive thermo-mechanical models are able to produce substantial heat flow (magma as consequence) within the JT and surrounding rift-host lineament. The model 1 invo l ves the peeling of the lower part of continental lithosphere from crust, followed by lithospheric thinning while hot upwelling asthenospheric replace the original cold lithospheric material. Decompression in the ascending mantle leads to partial melting and bimodal magmatism (crust and mantle) take place; the second model consists of underplating of mafic material probably in a stretched crust-mantle boundary. The changing from the model 1 to model 2 seems to be a progressive process

Reavaliaçao da evoluçao tectono-magmática do Graben de Jaibaras (nordeste do Brasil)

O Graben de Jaibaras é a mais importante bacia de idade cambro-ordoviciana que ocorre em terrenos pré-cambrianos da Província Borborema e do Escudo Nigeriano. Trata-se de uma feição bastante alongada NE-SW, resultado de reativações de descontinuidades miloníticas crustais pertencentes ao Lineamento Transbrasiliano. O preenchimento da bacia, de natureza muito imatura, é geralmente caracterizado por leques aluviais de escarpas de falhas seguidos ve rtical e lateralmente por arenitos fluvio-lacustres interdigitados com extensos pacotes de folhelhos ave rmelhados. A evolução, dominada por uma forte atividade magmática, é outro aspecto fundamental desse graben. Com efeito, o Graben de Jaibaras é um excelente exemplo de uma bacia cujos preenchimento sedimentar e os eventos magmáticos são resultados de processos cogenéticos. A evolução magmática do Graben de Jaibaras compreende basicamente quatro eventos, todos separados temporal e espacialmente. O Enxame de Diques de Coreaú, de idade vendiana, constitui o estágio inicial de abertura do rifte. Antecedendo ao prenchimento do Graben, a evolução desse sistema distensional, no cambriano inferior, permitiu o alojamento do Pluton de Mucambo através de reativação oblíqua da anisotropia crustal delimitadora da borda oeste do Graben. No cambriano médio a sedimentação da bacia foi acompanhada por um volume considerável de magma essencialmente básico (a Suíte Parapuí). Em seguida, houve a intrusão passiva do Pluton de Meruoca. As interações estratigr á ficas entre os eventos magmáticos e as sucessões sedimentares no Graben podem ser perfeitamente estabelecidas a partir das relações estruturais clássicas de “corte e preenchimento” associadas ao bom controle geocronológico. A través da configuração geométrica e da interrelação dos corpos ígneos com as rochas hospedeiras obteve-se o campo de esforços durante a formação e o desenvolvimento do Graben. A partir das características físico-químicas do magmatismo, discutiu-se a resposta térmica da crosta durante a formação e alojamento dos corpos. Nesse contexto, interpreta-se que o Graben foi nucleado durante um campo de stress de direção NW-SE. Esse campo regional, aliado a uma pequena componente direcional ao longo da anisotropias crustais reativadas, persistiu durante todo o desenvolvimento do Graben, incluindo o alojamento dos plutons. Dois modelos termo-mecânicos plausíveis, em termos de geração de calor resultando em magmatismo, foram sugeridos como “motores” regionais na criação do Graben. O modelo 1 envo l ve o desacoplamento da raiz da litosfera previamente espessada, seguido de um desajuste termo-isostático provocado pelo afinamento litosférico, enquanto que material astenosférico quente preencheria o espaço anteriormente ocupado pela parte delaminada da litosfera. O segundo modelo consiste do underplating de magma básico na base da crosta. A vinculação entre esses dois modelos foi considerada como um processo progressivo.The Jaibaras Trough (GJ), located in the Northeast Brazil, represents the most important, prominent and extensive exposure of Early Phanerozoic sedimentary sequences in a wide Brasiliano-age area, including Borborema Province and West Africa (mainly Nigerian Shield). The main basin feature is delineated by major brittle normal faults, resulted from reactivation of mylonite shear zones inside the so-called Transbrasiliano Lineament. The Jaibaras rift evolution is not only partially constrained by the stratigraphic record of the basin in fill, which is characterized by basal fault-scarp-related paraconglomerates followed laterally and vertically by fluvial-lacustrine sandstones which are interbeded with reddish shale, but also by the petrological signatura rift-related magmatic activity. Magmatic evolutive aspects of GJ comprises basically four temporal and spatially separated igneous steps. The earlier phase involved the Coreaú dike swa rm, which is Vendian in age, representing the initial tectonic pulse of the rift opening. With the continued breakup, reactivation of deeper shear zones gave rise to the emplacement of Mucambo Pluton during Early Cambrian times, preceding the main rift infill. The basin sedimentation was accomppanied by huge volume of volcanism, most of it occurring as flood basalts, dikes and sills in shape. The Meruoca Pluton is the last basin-related igneous manifestation during Upper Cambrian. Sequential stratigraphic interactions between sediments and magmatic events are perfectly constrained at the expense of thermal-structural features such as contact aureoles, faulted contacts, abuting and cross-cuting. Local and regional stress-field during GJ formation were obtained by using the configuration of magmatic bodies and their interplays with host-rocks. The physical-chemical characteristics of igneous activity also allows us to discuss the simultaneous thermal crustal-mantelic response due to magmagenesis and the emplacement processes. Initially, during the GJ nucleation, a NW-SE extensional pulse is recorded by the intrusion of the Coreaú Dike Swa rm, following hydraulic fracturing model. Following the same extensional stress-field, the studied plutons were emplaced by using nort h west-trending preexisting basement structures in areas of releasing bends where their feeder dikes were intruded. We hypothesize that two distinctive thermo-mechanical models are able to produce substantial heat flow (magma as consequence) within the JT and surrounding rift-host lineament. The model 1 invo l ves the peeling of the lower part of continental lithosphere from crust, followed by lithospheric thinning while hot upwelling asthenospheric replace the original cold lithospheric material. Decompression in the ascending mantle leads to partial melting and bimodal magmatism (crust and mantle) take place; the second model consists of underplating of mafic material probably in a stretched crust-mantle boundary. The changing from the model 1 to model 2 seems to be a progressive process

Worldwide evaluation of CAMS-EGG4 CO₂ data re-analysis at the surface level

This study systematically examines the global uncertainties and biases in the carbon dioxide (CO(2)) mixing ratio provided by the Copernicus Atmosphere Monitoring Service (CAMS). The global greenhouse gas re-analysis (EGG4) data product from the European Centre for Medium-Range Weather Forecasts (ECMWF) was evaluated against ground-based in situ measurements from more than 160 of stations across the world. The evaluation shows that CO(2) re-analysis can capture the general features in the tracer distributions, including the CO(2) seasonal cycle and its strength at different latitudes, as well as the global CO(2) trend. The emissions and natural fluxes of CO(2) at the surface are evaluated on a wide range of scales, from diurnal to interannual. The results highlight re-analysis compliance, reproducing biogenic fluxes as well the observed CO(2) patterns in remote environments. CAMS consistently reproduces observations at marine and remote regions with low CO(2) fluxes and smooth variability. However, the model’s weaknesses were observed in continental areas, regions with complex sources, transport circulations and large CO(2) fluxes. A strong variation in the accuracy and bias are displayed among those stations with different flux profiles, with the largest uncertainties in the continental regions with high CO(2) anthropogenic fluxes. Displaying biased estimation and root-mean-square error (RMSE) ranging from values below one ppmv up to 70 ppmv, the results reveal a poor response from re-analysis to high CO(2) mixing ratio, showing larger uncertainty of the product in the boundaries where the CAMS system misses solving sharp flux variability. The mismatch at regions with high fluxes of anthropogenic emission indicate large uncertainties in inventories and constrained physical parameterizations in the CO(2) at boundary conditions. The current study provides a broad uncertainty assessment for the CAMS CO(2) product worldwide, suggesting deficiencies and methods that can be used in the future to overcome failures and uncertainties in regional CO(2) mixing ratio and flux estimates

Holographic Principle bounds on Primordial Black Hole abundances

The generalized Second Law of thermodynamics and the Holographic Principle are combined to obtain the maximum mass of black holes formed inside a static spherical box of size $R$ filled with radiation at initial temperature $T_{i}$. The final temperature after the formation of black holes is evaluated, and we show that a critical threshold exists for the radiation to be fully consumed by the process. We next argue that if some form of Holographic Principle holds, upper bounds to the mass density of PBHs formed in the early universe may be obtained. The limits are worked out for inflationary and non-inflationary cosmological models. This method is independent of the known limits based on the background fluxes (from cosmic rays, radiation and other forms of energy) and applies to potentially important epochs of PBH formation, resulting in quite strong constraints to $\Omega_{pbh}$.Comment: Latex file, 2 .ps figures. To appear in Classical and Quantum Gravit

Correlação entre distância genética e heterose para comprimento de panícula por cruzamento dialélico entre acessos de arroz (Oryza sativa L.) de base genética ampla.

O objetivo desse trabalho foi correlacionar os dados de distância genética de Rogers modificada por Wright e a heterose observada no caractere comprimento de panícula, um dos componentes de produtividade do arroz, dos 120 híbridos obtidos nesses cruzamentos

Incidência de percevejos em genótipos de arroz no Tocantins.

O objetivo deste trabalho foi a avaliação da intensidade de ataque de percevejos dos grãos em diferentes genótipos de arroz irrigado tropical. Espera-se com isso que não haja diferenças estatísticas entre os genótipos avaliados

Obtention of plant peroxidase and its potential for the decolorization of the reactive dye Remazol Turquoise G 133%

Peroxidases can be used in the decolorization process. There is a growing interest for new sources of this enzyme and for obtaining economically viable processes. In this work, a low-cost vegetable peroxidase extraction process is proposed; the resulting enzyme is characterized to determine its optimum pH, temperature, and stability conditions, and it is then applied in the decolorization of reactive dye Remazol Turquoise G 133%. The turnip peroxidase (TP) was utilized as an enzymatic source. This enzyme exhibited maximum activity at pH 7.0, and it was active in the temperature range of 30 to 50 °C, which favors its use in industrial processes. Acetone was the most efficient solvent to induce precipitation. The removal of Remazol Turquoise G 133% was 56.0% complete after 50 min, while 41.0% of the same dye was removed with the commercial horseradish peroxidase enzyme in 50 min. TP presents potential as a viable alternative in the decolorization of textile wastewaters

Etiologia da podridão do caule e ramos da mamoneira (Ricinus communis).

A Mamoneira também conhecida como carrapateira é uma planta oleaginosa pertencente à família Euphorbiaceae. É reconhecidamente grande importância econômica em diversos países, principalmente pelo o uso de seu óleo, amplamente utilizado na indústria como matéria prima de vários produtos, como biodiesel, fármacos, tintas e plásticos. No Brasil, a mamoneira é encontrada em diversas regiões, entretanto foi na região semiárida do Nordeste que o cultivo dessa oleaginosa teve a maior expansão. O aumento da área plantada no Brasil tem sido acompanhado da ocorrência de diversas doenças como a podridão do caule e ramos causada supostamente por Lasiodiplodia theobromae