Programa de Pós-Graduação em Engenharia Civil
http://repositorio.ufsm.br/handle/1/12006
2024-03-28T09:55:01ZMicroplásticos em água para consumo humano: diagnóstico e avaliação de riscos à saúde humana
http://repositorio.ufsm.br/handle/1/31626
Microplásticos em água para consumo humano: diagnóstico e avaliação de riscos à saúde humana
Goerck, Janaina
Wolff, Delmira Beatriz
Microplastics (MP) are present in various environments and are considered ubiquitous. Although
contaminant identification is increasingly common, studies related to the risks associated with human
health still challenge researchers. The aim of the present work was to investigate the presence of MP
in water intended for human consumption and assess the possible risks associated with its ingestion.
In the first step, with a methodological tool of a systematic review, an extensive literature search was
made, which revealed that MP were detected in treated water at water treatment plants (WTP), that
conventional coagulation and filtration processes were found to be effective in removing larger-sized
MP (> 10 μm), while the efficiency is limited for the removal of MP < 10 μm, resulting in the
persistence of these particles in treated water, especially in the range of 1 – 5 μm. Controlled filtration
demonstrated the potential for MP removal, while advanced treatments showed no clear trends in
behavior regarding these particles. For the standardization of MP studies in WTPs, guidelines for
conducting research were proposed, suggesting that studies be conducted using LD > 1 µm by μRaman spectroscopy. In the second phase of this study, the aim was to evaluate human exposure to
MP through the consumption of drinking water in adult males and females as well as in children. This
was achieved through a series of calculations using deterministic and probabilistic assessments. The
daily intake rate was estimated at 69 µg MP.d-1
, and proportional intakes based on body weight
resulted in 0.92, 1.15, and 3.44 µg MP/kg bw/d for males, females, and children, respectively. The
risk quotient (RQ) and sensitivity analysis were obtained through a probabilistic assessment (Monte
Carlo). The monomers acrylamide, vinyl chloride and propylene oxide resulted in RQ > 10-5
,
indicating carcinogenic effects. The RQ results for non-carcinogenic effects were below the limit of
1, both for the mean and the 95th percentile. The monomer methyl terephthalate resulted in a RQ
between 0.2 and 1 for children, warranting attention." Ultimately, the main effects of MP on human
health are related to genotoxicity. In conclusion, this study provided valuable insights into the
presence of microplastics in human drinking water, highlighting potential concerns and providing a
solid foundation for future investigations into the health impacts resulting from this exposure.
Universidade Federal de Santa Maria
Tese
2023-12-19T00:00:00ZMicroestrutura, absorção de água e resistência à penetração de cloretos em concretos com substituição de cimento Portland por altos teores de fíler calcário e cinza volante
http://repositorio.ufsm.br/handle/1/31355
Microestrutura, absorção de água e resistência à penetração de cloretos em concretos com substituição de cimento Portland por altos teores de fíler calcário e cinza volante
Silva, Silvane Santos da
Lübeck, André
The use of alternative materials such as mineral additions (AM) is being studied, evidenced and
expanded within the cement industry, and in the formulation of concrete. This demand is due to the
environmental impacts caused by the manufacture of clinker, responsible for a large part of CO2
emissions. The sector has been adapting to new requirements with the use of chemically inert or
active AM. Within this scope, the present thesis aimed to develop concretes with high levels of
replacement of Portland cement (PC), in binary mixtures of limestone filler (FC) and ternary
mixtures of FC and fly ash (CV), in contents of up to 80% by mass. Aiming to produce concretes
with reduced environmental impact, but which, at the same time, present an adequate performance,
the study of the packing of the constituent particles of the mixtures was carried out and through
these, the mechanical performance was evaluated in relation to the axial compression, at the ages
of 28 and 91 days, the microstructural properties in pastes through analyzes of XRD, TG/DTG, PIM
and SEM, at 91 days of age, still, some of the main properties referring to the durability of the
concrete were examined, such as the absorption by capillarity at 91 days of age and chloride
penetration by immersion (EPCI) at 7, 14, 28, 91, 180 and 360 days of age. Four mixtures were
developed, with FC contents of up to 70% and CV of 10% by mass, with the use of a superplasticizer
additive, which allowed the use of a water/binder (w/al) factor of 0.25, with a consistency in the
range of 100±20 mm, resulting in resistances to axial compression of the order of 52.0 to 88.5 MPa
at 91 days of age, highlighting the performance of the 70FC1 mixture 0CV, as it presented a
resistance to axial compression of 52.0 MPa, at 91 days, having only 20% CP in its composition. In
relation to the two evaluated durability properties (water absorption and chloride penetration) a
sharp increase was observed according to the replacement content. In view of the above, the
analyzes showed the possibility of making concrete with high FC levels equal to or above 50%,
provided that appropriate measures are used, such as strict production control and the means to
which it will be inserted, highlighting the indispensable use of superplasticizer additive.
Universidade Federal de Santa Maria
Tese
2023-05-29T00:00:00ZProposta de classificação acústica de habitações brasileiras baseadas na percepção dos usuários
http://repositorio.ufsm.br/handle/1/31118
Proposta de classificação acústica de habitações brasileiras baseadas na percepção dos usuários
Lourenço, Willian Magalhães de
Mohamad, Gihad
The growth and verticalization of cities have caused significant changes in construction
methods and materials that directly impact architectural acoustics. Buildings must, due to their
primary function, guarantee habitability and quality of life for users, with acoustic comfort
being one of the factors that is included in this demand. However, the acoustic performance
levels required by the regulations that regulate Brazilian civil construction do not necessarily
guarantee the acoustic quality and comfort of users of residential buildings. The present work
aims to propose an acoustic classification method for residential buildings in Brazil, based on
the acoustic performance of flooring systems, internal and external vertical seals and noise from
building and sanitary installations and equipment, based on the perception of users. . The
method developed evaluates three components: the context (the environmental integration of
the building, which influences the quality of the internal environment), the building
(architectural design issues that guarantee better acoustic conditions in spaces, common access,
circulation, among others) and housing (performance of construction systems), through a
questionnaire, applied to the Brazilian population, measuring discomfort and priorities in terms
of sound insulation from the perception of Brazilians. It was applied in three case studies, two
buildings in the city of Santa Maria, multifamily, one made of reinforced concrete, the other
made of structural masonry, and a third study based on bibliographical references (performance
through research), demonstrating that it is possible Also use the tool in design stages before
execution. Therefore, with the evaluation of the three components, a global acoustic evaluation
of each building can be drawn up, with the aim of applying the labeling of the acoustic quality
of housing units, promoting housing quality and introducing a new market valuation parameter.
Universidade Federal de Santa Maria
Tese
2023-11-07T00:00:00ZAcústica de museus: uma proposta metodológica para subsídio ao processo projetual de salas com exposições permanentes
http://repositorio.ufsm.br/handle/1/30701
Acústica de museus: uma proposta metodológica para subsídio ao processo projetual de salas com exposições permanentes
Barbo, Marselle Nunes
Carneiro, Eric Brandão
Museums are spaces for memory, appreciation, and, very importantly, the transmission
of knowledge. Due to the variability of museum typology, the study of the acoustics of
these spaces must be aligned with the needs of the exhibition model. This thesis aims
to establish acoustic and design parameters for these buildings to balance reverberation, intelligibility at short distances, and speech decay based on the acoustic characterization of permanent exhibition museums. The parameters of free-plan offices were
adopted, as was the testing methodology. Two permanent exhibition museums with
different architectural typologies were studied: the Pinacoteca of São Paulo museum,
housed in a century-old neoclassical building that originally housed a school, which
was revitalized to become a museum. It has gallery-style rooms. The São Paulo Museum of Art (MASP) was built to be a museum in the modernist style. The exhibition
method is contemporary, with works displayed on glass easels. Tests were carried out
in museums for acoustic characterization and three-dimensional modeling, which allowed the development of scenario proposals that contribute to improving the acoustic
quality of these spaces. The speech transmission index (STI) for native and non-native
speakers, distraction distance (rD), clarity (C50), reverberation time, and A-weighted
speech level (LP,A,S) were analyzed. The STI and rD parameters proved to be satisfactorily applicable to museums with permanent exhibitions. The reverberation time should
be associated with the intelligibility and distraction distance parameters and used in
the design process phase. The results for the clarity parameter (C50) were overestimated, while the LP,A,S showed little change between the receivers. The free-plan office
test methodology can be applied to museums. It is concluded that using the proposals
with the largest apparent absorption area (AT) is unnecessary since they increase intelligibility throughout the room, which is not the case for museums. As a prospect for
future work, it is possible to continue the research with subjective studies.
Universidade Federal de Santa Maria
Tese
2023-09-27T00:00:00Z