2,823 research outputs found
Algebraically special solutions in AdS/CFT
We investigate the AdS/CFT interpretation of the class of algebraically
special solutions of Einstein gravity with a negative cosmological constant.
Such solutions describe a CFT living in a 2+1 dimensional time-dependent
geometry that, generically, has no isometries. The algebraically special
condition implies that the expectation value of the CFT energy-momentum tensor
is a local function of the boundary metric. When such a spacetime is slowly
varying, the fluid/gravity approximation is valid and one can read off the
values of certain higher order transport coefficients. To do this, we introduce
a formalism for studying conformal, relativistic fluids in 2+1 dimensions that
reduces everything to the manipulation of scalar quantities.Comment: 30 pages + appendices, 2 figures; v2: typos corrected, ref. adde
Nectaries and reproductive biology of croton sarcopetalus (euphorbiaceae)
Flower morphology, nectary structure, nectar chemical composition, breeding system, floral visitors and pollination were analysed in Croton sarcopetalus, a diclinous-monoecious shrub from Argentina. Male flowers have five receptacular nectaries, with no special vascular bundles, that consist of a uniserial epidermis with stomata subtended by a secretory parenchyma. Female flowers bear two different types of nectaries: inner (IN) and outer (ON) floral nectaries. IN, five in all, are structurally similar to the nectaries of male flowers. The five ON are vascularized, stalked, and composed of secretory, column-shaped epidermal cells without stomata subtended by secretory and ground parenchyma. In addition, ON act as post-floral nectaries secreting nectar during fruit ripening. Extrafloral nectaries (EFN) are located on petioles, stipules and leaf margins. Petiolar EFN are patelliform, stalked and anatomically similar to the ON of the female flower. Nectar sampled from all nectary types is hexose dominant, except for the ON of the female flower at the post-floral stage that is sucrose dominant. The species is self-compatible, but geitonogamous fertilization is rarely possible because male and female flowers are not usually open at the same time in the same individual, i.e. there is temporal dioecism. Flowers are visited by 22 insect species, wasps being the most important group of pollinators. No significant differences were found in fruit and seed set between natural and hand pollinated flowers. This pattern indicates that fruit production in this species is not pollen/pollinator limited and is mediated by a wide array of pollinators. © 2001 The Linnean Society of London.Fil: Freitas, Leandro. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Bernardello, Gabriel Luis Mario. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de BiologÃa Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas FÃsicas y Naturales. Instituto Multidisciplinario de BiologÃa Vegetal; ArgentinaFil: Galetto, Leonardo. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de BiologÃa Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas FÃsicas y Naturales. Instituto Multidisciplinario de BiologÃa Vegetal; ArgentinaFil: Paoli, Adelita. Universidade Estadual Paulista Julio de Mesquita Filho; Brasi
Application of compost-derivated carbon catalysts on catalytic wet peroxide oxidation of leachate waters from mechanical and biological treatment plant units for municipal solid waste
Alternatives to deal with municipal solid waste (MSW), such as mechanical
biological treatment (MBT) plants, are a trend. In these plants, the organic matter
is digested by anaerobic bacteria, generating biogas and reducing the solid mass,
generating simultaneously a solid compost and a liquid leachate as side-streams.
The leachate has a complex composition and cannot be treated by conventional
wastewater treatment methods, while the compost is mainly used as an
agriculture fertilizer, but the amount produced is higher than its demand. This
work deals with the valorization of compost to produce hydrochars and biochars,
through hydrothermal carbonization (HTC) and pyrolysis, respectively, with
suitable properties to serve as catalysts for the catalytic wet peroxide oxidation
of the landfill waters generated in MBT (TOC = 27 g L-1, COD = 60 g L-1, 38.8
mS/cm and 5 g L-1 of chloride ions). Seven catalysts were produced from compost
and characterized by several techniques. The catalysts were subjected to
screening tests of H2O2 decomposition and the best two were selected to be
further studied in the catalytic wet peroxide oxidation (CWPO) of leachate. The
experimental conditions of the process, temperature, pH, catalyst load and H2O2
addition were studied seeking optimization. The best experimental conditions
found were T = 80 ºC, pH = 3.0, 7.2 g L-1 of catalyst, 85.71 g L-1 of H2O2, added
in five batches each hour. Under these experimental conditions, the hydrochar
prepared at 230 ºC (HTC-230) achieved removal of 43 % of chemical oxygen
demand (COD) and total organic carbon (TOC), turbidity, aromaticity, phenols,
chlorides and 5-day biological oxygen demand, (BOD5) removals of 52, 95, 93,
72, 35 and 93 %, respectively. Resins were used to pre-treat the leachate, in
order to enhance the CWPO results. Using a cationic adsorption resin (TP-207),
considering again operating conditions of T = 80 ºC, pH = 3.0, 7.2 g L-1 of
catalyst, 85.71 g L-1 of H2O2, the catalyst HTC-230 achieved 62 %, 55 %, is 97
%, 95 %, 46.5 %, and 97 % for COD, TOC, turbidity, aromaticity, chlorides, and
BOD5.As unidades de tratamento mecânico e biológico (TMB) são alternativas para
lidar com os resÃduos sólidos urbanos (RSU). Essas unidades através da
digestão anaeróbia da matéria orgânica, geram biogás e reduzem a massa
sólida, porém geram um resÃduo sólido (convertido em composto) e águas
lixiviantes (ou lixiviado) como sub-produtos. O lixiviado tem uma matriz
complexa, o que inviabiliza o seu tratamento pelos métodos convencionais,
enquanto o composto é usado principalmente como fertilizante agrÃcola. Este
trabalho tem como objetivo a valorização do composto para a produção de
materiais carbonáceos, através de carbonização hidrotérmica (CHT) e pirólise,
respectivamente. Os materiais obtidos, com propriedades para atuarem como
catalisadores no processo de oxidação catalÃtica com peróxido de hidrogénio
(CWPO), são posteriormente usados no tratamento do lixiviado (TOC = 27 g L-1,
CQO = 60 g L-1, 38,8 mS / cm e 5 g L-1 de iões cloreto). Neste trabalho foram
produzidos sete catalisadores a partir de composto e caracterizados por diversas
técnicas. Após testes de screening da atividade catalÃtica na reação de
decomposição de H2O2, dois deles, o primeiro de pirólise e o segundo de CHT,
C-800 e HTC-230, foram selecionados para ensaios de CWPO do lixiviado.
Foram estudadas as condições experimentais para otimizar o processo, variando
temperatura, pH, carga de catalisador e adição de H2O2. A condição
experimental ótima encontrada foi T = 80 ºC, pH = 3,0, 7,2 g L-1 de catalisador,
85,71 g L-1 de H2O2, adicionados em cinco doses com 1 h de intervalo. Sob essas
condições experimentais, o catalisador HTC-230 permitiu remoções de 43, 52,
95, 93, 72, 35 e 93% de carência quÃmica de oxigénio (CQO), carbono orgânico
total (TOC), turbidez, aromaticidade, fenóis, cloretos e carência biológica de
oxigénio de 5 dias (CBO5), respectivamente. Afim de potencializar os resultados
de CWPO foram utilizadas resinas para pré-tratar o lixiviado. Utilizando a resina
de adsorção catiónica TP-207, em condições de T = 80 ºC, pH = 3,0, 7,2 g L-1 de
catalisador, 85,71 g L-1 de H2O2, o catalisador HTC-230 permitiu remoções de
62, 55, 97, 95, 46,5 e 97% de COD, TOC, turbidez, aromaticidade, cloretos e
CBO5
A Causalidade JurÃdica na Apuração das Consequências Danosas na Responsabilidade Civil Extracontratual
O presente trabalho trata da utilização e aplicação da causalidade jurÃdica na apuração, extensão e delimitação das consequências dos danos decorrentes da responsabilidade civil extracontratual subjetiva. A tese propõe a individualização de elementos que favoreçam uma nova leitura e abordagem da causalidade com vistas à determinação de uma zona circunscrita à reparação de danos e à criação de um modelo teórico de referência para a aplicação prática na seleção dos danos indenizáveis. Está dividido em duas partes. Na primeira, tratam da origem, da noção e do desenvolvimento conceitual da causalidade, até a assunção de uma causalidade jurÃdica e da aplicação das teorias da causalidade na solução de problemas de responsabilidade civil; a individualização de elementos integrantes da causalidade para a verificação e a aplicação na apuração de danos. Na segunda, a utilização da causalidade jurÃdica na seleção dos danos indenizáveis, a sua inserção no Código Civil brasileiro, em matéria de indenização, e a formulação de um regime de imputação; os casos difÃceis, os danos por ricochete e os de perda de oportunidades, verificado na perda de uma chance, e a prova da causalidade, incluindo os casos de presunção.This work approaches the use and application of legal causality in the calculation, extent and delimitation of the consequences of damage from subjective extra-contractual liability. The thesis proposes the individualization of elements that favor a new reading and approach of causality in view of determining a restricted zone to repair damages and the creation of a theoretical model of reference for the practical application in the selection of compensable damage. It is divided into two parts. The first deals with the origin, development and conceptual notion of causality, to the assumption of a legal causality and application of causality theories in solving liability issues; individualization of integral elements of causality for the verification and application in the calculation of damages. Second, the use of legal causality in the selection of compensable damage, its insertion into the Brazilian Civil Code, relating to compensation, and the formulation of a charging system; difficult cases, rebound damages and lost opportunity damages, found with the loss of a chance, and proof of causality, including cases of presumption.La présente recherche aborde l’utilisation et l’application de la causalité juridique dans l’analyse, l’extension et la délimitation des conséquences des dommages résultant de la responsabilité civile extracontractuelle subjective. La thèse propose l’individualisation des éléments, favorisant une lecture et approche nouvelles de la causalité pour la détermination d’une zone circonscrite à la réparation de dommages et pour la création d’un modèle théorique de référence pour l’application pratique dans la sélection des dommages indemnisables. Elle a été divisée en deux parties. La première aborde l’origine, la notion et le développement conceptuel de la causalité, jusqu’à l’avènement d’une causalité juridique et l’application des théories de la causalité dans la résolution de problèmes à responsabilité civile ; l’individualisation d’éléments intégrants de la causalité pour la vérification et l’application dans l’analyse de dommages. Dans la deuxième, il est question de l’utilisation de la causalité juridique dans la sélection des dommages indemnisables, de son insertion dans le code civil brésilien en matière d’indemnisation, et de la formulation d’un régime d’imputation ; les cas difficiles, les dommages par ricochet et ceux de pertes d’opportunités, en étant vérifiée la perte d’une opportunité, et la preuve de la causalité, y compris les cas de présomption
Residual biomass characterization and evaluation of its influence on pyrolysis processes
Biomass is extensively accepted as one of the main potential sources for sustainable and renewable generation of fuels, chemicals and other carbon-based materials. Many advantages are
reported using biomass as an energy source, such as being a non-polluting alternative and its carbon neutrality. Numerous processes can be used to convert biomass, and namely the
pyrolysis process is a renewable, economical, and efficient way to produce chemicals and/or energy. Therefore, pyrolysis is an available technology for biomass conversion into energy. It
consists of a thermal decomposition process with the absence of oxygen, converting biomass into 3 fractions: biochar (solid fraction), bio-oil (liquid fraction) and gases. Hence, pyrolysis is
a recognized industrial process for biomass energy and chemical conversion. The bio-oil and biochar can be used as a fuel and as fertilizer respectively, and the gases can be recycled back
into the process. Biomass samples were characterized by proximate analysis, determining fixed carbon, moisture, volatiles and ashes composition, and by ultimate analyses, determining
the content of C, H, N, S and O. The content of hemicellulose, lignin and cellulose was also determined. The methodologies are described elsewhere [1-3] and all characterizations were
performed on a dry basis. Pyrolysis tests were performed in a fixed-bed vertical pyrolysis oven, with a maximum temperature of 500 to 700C, variable heating rate up to 50C/min,
retention time of 0.5 h, and N2 flow of 20 mL/min. The bio-oil and biochar were qualitatively characterized using FTIR and the products distribution was analyzed in relation to the biomass
samples previous characterizationThis work is funded by the Portuguese Foundation of Science and Technology (FCT) within the
framework of the SUBe Project, ref.: PCIF/GVB/0197/2017. The authors are grateful to the
Foundation for Science and Technology (FCT, Portugal) for financial support through national
funds FCT/MCTES (PIDDAC) to CIMO (UIDB/00690/2020 and UIDP/00690/2020) and SusTEC (LA/P/0007/2021).info:eu-repo/semantics/publishedVersio
Evaluation of temperature on the pyrolysis of residual biomass
One of the greatest challenges humanity has to deal with nowadays is climate change. In this context, residual biomass is considered a
critical potential source for its mitigation, as biomass is a renewable, sustainable and nearly endless available source for the generation
of fuels, chemicals and other carbon-based materials. Due to its carbon neutrality, residual biomass is being widely studied, and one of
the main technologies for fuel and/or energy production are pyrolysis, gasification, or combustion [1].
Among technologies for biomass conversion, pyrolysis is widely used. It consists of a thermal decomposition process in an atmosphere
without oxygen, to convert biomass into biochar, bio-oil and gases, generating no waste during the process [2].
The complexity of biomass pyrolysis arises from the difference in the decomposition of the biomass components combined with the
several parameters encompassed on the pyrolysis process. The reaction mechanisms and reaction rates depend on the thermal
processing conditions and reactor designs, among those the pyrolysis temperature significantly influences the distribution and
properties of the productsThis work is funded by the Portuguese Foundation of Science and
Technology (FCT) within the framework of the SUBe Project, ref.:
PCIF/GVB/0197/2017. The authors are grateful to the Foundation for
Science and Technology (FCT, Portugal) for financial support through
national funds FCT/MCTES (PIDDAC) to CIMO (UIDB/00690/2020 and
UIDP/00690/2020) and SusTEC (LA/P/0007/2021).info:eu-repo/semantics/publishedVersio
Biomass characterization and pyrolysis towards bio-oil production
One of the greatest challenges humanity has to deal
with nowadays is climate change. An important
strategy to mitigate climate change is replacing
fossil fuels with renewable sources of energy [1].
Biomass is considered one of the world's most
promising renewable energy sources, mainly due to
its nearly endless availability. Worldwide, each year
plants convert approximately 125 gigatons of carbon
from atmosphere into biomass, which is equivalent
to almost 300 million tons of oil per day [2].
There are many advantages in using biomass as an
energy source, namely its carbon neutrality and
being a non-polluting source. In this context, the
main technologies for fuel and/or energy production
from biomass are pyrolysis, gasification, or
combustion.This work is funded by the Portuguese Foundation of
Science and Technology (FCT) within the framework
of the SUBe Project, ref.:PCIF/GVB/0197/2017.info:eu-repo/semantics/publishedVersio
Evaluation of heating rate on the pyrolysis of residual biomass for biochar production
Biochar is a carbon-rich solid product
of biomass thermal conversion, which
contains several properties for a wide
range of applications that promote the
attention of industries and
researchers. The porous structure of
char particles enables its application
as soil fertilizer, adsorbent, catalyst,
among others [1].
In this context, biomass is a critical
resource, as it can be used for biochar
production at the same time produce
renewable energy, being able to
mitigate climate change phenomena.
There are many advantages to using
biomass as an energy source, namely
its carbon neutrality and being a nonpolluting
source. In this context, the
main technologies for fuel and/or
energy production from biomass are
pyrolysis, gasification, or combustion
[2].
Among technologies for biomass
conversion, pyrolysis is widely used,
consisting of a thermal decomposition
process in absence of oxygen, to
convert biomass into biochar, bio-oil
and gases, generating no waste during
the processThis work is funded by the Portuguese
Foundation of Science and Technology
(FCT) within the framework of the SUBe
Project, ref.: PCIF/GVB/0197/2017. The
authors are grateful to the Foundation for
Science and Technology (FCT, Portugal)
for financial support through national
funds FCT/MCTES (PIDDAC) to CIMO
(UIDB/00690/2020 and UIDP/00690/2020)
and SusTEC (LA/P/0007/2021).info:eu-repo/semantics/publishedVersio
A filosofia na UDV: Imaginários do PanenteÃsmo, Hermetismo e Hermenêutica
Ayahuasca religions such as Santo Daime, Barquinha and União do Vegetal are considered legitimately Brazilian because they syncretize Christian, Spiritist and Afro-descendant elements. We intend to establish a reflection that begins with a udvist cosmology, goes through ethical, epistemological elements and arrives at a philosophy of language with panentheistic foundations of the theology of the UDV, we will try to understand the União do Vegetal as a religious and philosophical system and demonstrate how the caboclo popular wisdom is permeated by ancient hermetic and hermeneutic ideas. Although it was founded by an almost illiterate person, as was the case of Mestre Gabriel, the disciples of this master using the entheogen Ayahuasca are able to develop their memory degrees to remember details from childhood to past lives, that is, unfolding as part of a Christian conception of a form of spiritism. This knowledge is very similar to that of Pythagoras, Socrates, and even the theological presuppositions of St. Augustine. Therefore, we will try to approach an overview of the ritual aspect of the UDV, as well as a more critical view of the principles that make this society establish itself as the largest Brazilian hoasqueira religion with tens of thousands of adherents. We will use a methodology based on bibliographic reviews, as well as an analysis of an oral history of how the teachings can be preserved and faithful to the doctrine of Mestre Gabriel, which will finally be contextualized in a hermeneutic perspective of Hoasqueira religiosity.Religiões ayahuasqueiras como o Santo Daime, Barquinha e União do Vegetal são consideradas legitimamente brasileiras porque sincretizam elementos cristãos, espÃritas e afrodescendentes. Pretendemos estabelecer uma reflexão que se inicia por uma cosmologia udvista, perpassa por elementos éticos, epistemológicos e chegam a uma filosofia da linguagem com fundamentos panenteÃstas da teologia da UDV, tentaremos compreender a União do Vegetal como um sistema religioso e filosófico e demonstrar como a sabedoria popular cabocla está permeada de ideias herméticas e hermenêuticas antigas. Ainda que tenha sido fundado por uma pessoa quase analfabeta, como foi o caso do Mestre Gabriel, os discÃpulos deste mestre se utilizam do enteógeno Ayahuasca se mostram capazes de desenvolver seus graus de memória para recordar detalhes desde a infância até as vidas passadas, ou seja, desdobrando-se como parte de uma concepção cristã de uma forma de espiritismo. Estes são conhecimentos bem semelhante ao que Pitágoras, Sócrates e até mesmo dos pressupostos teológicos de Santo Agostinho. Logo, tentaremos abordar uma visão geral do aspecto ritual da UDV, bem como uma visão mais crÃtica dos princÃpios que fazem esta sociedade se estabelecer como a maior religião hoasqueira brasileira com dezenas de milhares de adeptos. Nos utilizaremos de uma metodologia baseada em revisões bibliográficas, bem como de uma análise de uma história oral de como os ensinos conseguem ser preservados e fiéis a doutrina do Mestre Gabriel que por fim, serão contextualizados numa perspectiva hermenêutica da religiosidade hoasqueira
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