Navegando por Assunto "Seasonality"

Agora exibindo 1 - 9 de 9

Acesso aberto (Open Access)
Avaliação espacial e sazonal da precipitação no estado do Pará
(Universidade Federal do Pará, 2013-10-21) MENEZES, Franciani Pantoja; FERNANDES, Lindemberg Lima; http://lattes.cnpq.br/4641468846318922
The objective of this study was to evaluate the spatial variability and seasonal rainfall in the State of Para. Were used monthly data and annual rainfall of 66 rainfall stations available in hydrometeorological network of National Water Agency – ANA for the period 1982 - 2011. The data were organized with the help of Microsoft Excel spreadsheets. The historical series that fail, these were corrected and consisted. Para is the second largest Brazilian state holds great extent and diversity of natural resources. In terms of density, the state, as well as the seven river basin showed low density of rainfall stations do not comply with the recommendations of the WMO as the minimum density of rain gauges, are areas that require better monitoring. As for seasonality, precipitation shows two distinct seasons, a drought (winter and spring in the Southern Hemisphere), with rainfall less than 100 mm, and a rainy season (summer and autumn in the Southern Hemisphere) with rainfall exceeding 200 mm. The results obtained by the Mann - Kendall and Spearman did not detect any trend of increase or decrease in rainfall during the study period. Through cluster analysis of monthly precipitation were defined 3 Homogeneous Regions with similar climatic characteristics (R1, R2 and R3) to the state of Para.
Acesso aberto (Open Access)
Avaliação probabilística do impacto da recarga rápida de veículos elétricos nos sistemas de distribuição de energia elétrica
(Universidade Federal do Pará, 2024-11-13) HERNÁNDEZ GÓMEZ, Oscar Maurício; VIEIRA, João Paulo Abreu; http://lattes.cnpq.br/8188999223769913
The mass adoption of electric vehicles (EVs) is transforming the automotive sector, driven by environmental concerns and technological advancements. Governments and companies are investing in the expansion of charging networks, focusing on fast charging to meet the growing demand. Developing a robust infrastructure of charging stations is essential to eliminate “range anxiety” and encourage the transition to EVs. Fast charging is crucial for the success of vehicle electrification. It allows batteries to be charged much more quickly than conventional charging, increasing convenience for users and improving the overall user experience. As more fast-charging stations are installed, consumer confidence in EVs grows, paving the way for a more sustainable future. With a well-distributed fast-charging network, EVs become a practical alternative to fossil fuel-powered vehicles, accelerating the transition to greener mobility. However, fast charging of EVs can cause technical impacts on medium voltage networks. The high current demand can result in voltage drops, especially in areas with weaker distribution infrastructure. Transformers can be overloaded, reducing their lifespan and increasing the risk of failures. Excessive heating of conductors due to high current can also cause losses and damage cables. These challenges highlight the need for proper planning and investments in electrical infrastructure to support the increase in fast charging. A probabilistic analysis of the impact of fast charging on medium voltage networks is crucial. Energy demand varies throughout the year due to seasonal factors, such as the use of air conditioning in summer and heaters in winter. Fast charging adds a considerable load to the network, which can coincide with these demand peaks, exacerbating management challenges. The installation of multiple charging points can cause voltage fluctuations and overloads. Probabilistic analysis helps predict these impacts and develop mitigation strategies by simulating charging scenarios and user behaviors. This allows for more precise infrastructure planning, including network reinforcements and improvements to ensure supply reliability. This thesis proposes a probabilistic methodology to evaluate the impact of fast charging of electric vehicles on medium voltage distribution networks, considering voltage drops, network element loading, and regulator tap changes. Using the Power Factory software by DIgSILENT©, a real feeder in Brazil is simulated, analyzing different case studies. Three fast charging stations (FCS) are connected, each with six charging points of 100 kVA, totaling 600 kVA per EP. The charging profile of the EPs is programmed with stochastic variables. Finally, a Volt/Var control strategy is presented to mitigate the impact on voltage drops and regulator tap changes, allowing reactive power injection without the need for communication between charging points.
Acesso aberto (Open Access)
Biometria testicular, eletroejaculação e características seminais de caititus, Tayassu tajacu Linnaeus, 1758 (Mammalia, Artiodactyla, Tayassuidae) mantidos em cativeiro na Amazônia Oriental
(Instituto Nacional de Pesquisas da Amazônia, 2010-12) KAHWAGE, Priscila Reis; GARCIA, Alexandre Rossetto; GUIMARÃES, Diva Anelie de Araújo; OHASHI, Otávio Mitio; RAMOS, Rosemar Silva Luz; DIAS, Hilma Lúcia Tavares; ALBUQUERQUE, Natália Inagaki de; BARTHA, Mário Mansour Pinheiro
Research development in semen collection and sperm evaluation of Tayassu tajacu are necessary. The aims of this research were to evaluate testicular biometry of captive collared peccaries, test electroejaculation for semen collection and evaluate seminal characteristics during the year. Eight animals were submitted to electroejaculation and semen samples were evaluated according their physical and morphological characteristics. Left testicles measured 3.8 ± 0.4 cm X 2.6 ± 0.3 cm and presented 2.3 ± 0.2 of consistence, while right testicles were 3.8 ± 0.5 cm X 2.7 ± 0.3 cm and presented 2.3 ± 0.2 of consistence. Success rate on semen collections achieved 75.21%. Semen presented 0.81 ± 0.86 mL (volume), 137.44 ± 153 x 106 sptz mL-1 (sperm concentration), 7.92 ± 0.73 (pH), 52.66 ± 28.79% (sperm motility), 2.2 ± 0.8 (vigour), 55.84 ± 28.55% (plasmatic membrane integrity), 22.87 ± 12.93% (primary defects), 9.11 ± 5.88% (secondary defects) and 31.52 ± 13.81% (overall defects). Seminal characteristics showed no expressive variation along the year. Testicular symmetry was observed, electroejaculation was an efficient method to semen collection and slight mensal oscillations of seminal quality were not enough to characterize collared peccaries as seasonal reproductive animals.
Acesso aberto (Open Access)
Características da estabilidade estática e dinâmica da atmosfera em cultivo de palma de óleo no Leste da Amazônia
(Universidade Federal do Pará, 2020-09-30) CIRINO, Luciana dos Santos; ARAÚJO, Alessandro Carioca de; http://lattes.cnpq.br/6188087583954899; https://orcid.org/0000-0002-7361-5087
Considering the constant land use changes in the Amazon region, which determine the microclimate variability, the oil palm cultivation plays important roles in the environmental context and its interactions with the atmosphere. In this sense, this work aims to investigate the behavior of the atmospheric layer over an oil palm intercrop with interspecific hybrids (HIE) (Elaeis guineensis Jacq. x Elaeis oleifera (Kunth) Cortés) in eastern Amazonia. The study was conducted in the company Marborges Agroindústria S.A., located in Moju, Pará. The age of the plantation was 8 years (in 2014), and the average height of the top of the canopy was approximately 8 m. The data used in this work were obtained by a micrometeorological tower, and comprise the period from January to December 2014. During the daytime period, the highest potential temperatures (θ) were observed at the heights of 2.25 m and 6.75 m above the ground, indicative of static instability. Unlike the night period, where the values of θ were higher above the top of the canopy, indicative of static stability. The less rainy period presented higher wind speeds, with a difference of 1 m/s in relation to the rainy period of the region. Through air temperature and wind speed data the static and dynamic weather conditions over the crop were investigated. Atmospheric conditions of neutrality and stability predominated in both periods (-0.25 < Ri > 0.25).
Acesso aberto (Open Access)
Estudo dos riscos e benefícios associados ao consumo de três espécies de peixes da Amazônia
(Universidade Federal do Pará, 2019-09-20) GOMES, Luciana Cristina Mancio; LOURENÇO, Lúcia de Fátima Henriques; http://lattes.cnpq.br/7365554949786769
Fishing is one of the most explored activities in the amazon region, fish is an important protein source, however, it can represent one of the main vehicles of contamination due to its great capacity to bioaccumulate substances in tissues such as muscle and organs, being considered excellent bioindicators of the species. Its habitat. The aim of the present work was to study the amazonian species, curimatã (prochilodus nigricans), goby hake (macrodn ancylodon), and pyramutaba (brachyplatystoma vaillantii) by investigating the risks or benefits associated with consumption. In the muscle tissue and liver of the fish in different seasonal periods (rainy and dry season) amino acid and fatty acid profile analyzes were performed by liquid and gas chromatography. The determination of essential elements (cu, fe, mg, na and zn) was quantified by flame atomic emission spectrometry and the contaminants, lead (Pb) and mercury (Hg) by graphite furnace atomic absorption spectrometry. The validation of the methodology was performed through the addition and recovery method. The results obtained in the muscle and liver were correlated with biometric data, species feeding habits and the limits established by the national health surveillance agency for human consumption. The calculation of the tolerable weekly intake index (PTWI) was applied for the toxic elements pb and hg in different seasonal periods. According to the results, the species presented oleic (n-9), linoleic (omega-6) and arachidonic (omega-6) polyunsaturated fatty acids in the muscle, whereas in the liver the three species were c18:0, c18:1ω9, c18:2ω6, c20:4ω6, c22:6ω3. The total saturated fatty acid contents identified were higher in piramutaba, polyunsaturated in hake and monounsaturated in curimatã. Regarding the amino acid profile of the fillets, the highest predominance was histidine, alanine and serine. The species studied presented high levels of monounsaturated and polyunsaturated fatty acids. The monounsaturated ones presented higher contents in the curimatã species and the polyunsaturated ones were higher in the hake, both in the muscle and liver. Regarding minerals, calcium levels were quite significant between species in different seasonal periods, being predominant in the dry season, while Fe, Cu, Na and Zn presented higher levels in the rainy season. In the liver, during the rainy season, Mg, Zn and Cu values had average concentrations in curimatã specimens. While in the dry season the ca, mg, na and zn contents had higher predominance among the species. Regarding contaminants, pb levels were higher than the limit allowed by the legislation, showing significant behavior in relation to seasonality. The hg content in the three species was higher in the rainy season, the curimatã species reached higher levels in the muscle. In the liver, the levels of Hg in the rainy season were above the limit recommended by the legislation. In the dry season, the curimatã species contributed the most with 131.79%, exceeding the tolerable weekly limit of hg consumption, being considered inappropriate. According to the estimated weekly intake of toxic elements (PTWI) during the rainy season, acceptable limits were found among the contaminants. However, in the dry season, curimatã contributed the most with 131.79%, exceeding the tolerable weekly consumption limit. From Hg. It is concluded that the constant biomonitoring of the species commercialized in Belém-PA and surroundings that may present some contamination by toxic elements is necessary, thus avoiding possible reflexes and the compromise of human health and fish reproductive process.
Acesso aberto (Open Access)
Fatores naturais e antrópicos que interferem na qualidade da água do Rio Tocantins, trecho Baião Mocajuba (PA)
(Universidade Federal do Pará, 2024-05-27) CORDEIRO, Leonardo Corrêa; XAVIER, Diego de Arruda; http://lattes.cnpq.br/4534357826122691; https://orcid.org/0000-0003-1644-3837; SILVA, José Francisco Berredo Reis da; http://lattes.cnpq.br/1338038101910673; https://orcid.org/0000-0002-8590-2462
The water quality in hydrographic basins can be understood through studies involving physical chemical, chemical, and biological parameters, taking into account anthropic activities and associated natural processes. The aim of this study was to analyze the behavior of physical chemical and chemical parameters in different seasonal periods in the hydrographic basin of the Tocantins River, Baião-Mocajuba stretch, to discuss water quality based on the interaction of anthropic factors and natural processes. For this purpose, secondary data were collected, and samples were taken at two points (P1 and P2) during distinct seasonal periods (less rainy and rainy) and at mid-tide cycle (13h). The results were discussed in light of the theory regarding natural and anthropic factors in processes that may interfere with riverine hydrochemistry and water quality. Parameters such as temperature, pH, electrical conductivity, dissolved oxygen, and total dissolved solids were measured in situ, and samples were collected for the determination of chemical parameters (Fe, Mn, Pb, Cu, Cd, Se, Al, As, Ba, B, Co, Cr, Mo, Ni, V, Zn, Sr, Ti, BOD, COD, Cl, F, NO3, NO2, SO4, PO4, total nitrogen, SiO2, NH3, Ca, Mg, Na, K, P, Dissolved Organic Carbon, alkalinity, hardness). The data were analyzed using descriptive statistics, analysis of variance, correlation, and principal component analysis. The results indicate that seasonality is a factor influencing water quality parameter values, except for SO4, H4SiO4, Ba, and Sr. On the other hand, tidal effects are crucial in altering water quality parameters, especially during the less rainy period, but these alterations do not exceed the limits established by CONAMA 357/2005. Principal component analysis identified that Ca, Mg, Ba, Sr, Mn, and hardness accounted for 44.6% of water quality parameters during the less rainy period, while during the rainy period, Mg, K, Ba, hardness, Sr, Ca, Mn, Na, dissolved oxygen, and Al accounted for 47.67%. It is concluded that the Tocantins River hydrographic sub-basin has been impacted anthropogenically due to the construction of the dam and agricultural activities. Future studies are suggested to measure the effects of these activities on the water quality of the Tocantins River.
Acesso aberto (Open Access)
Fatores naturais e antrópicos que interferem na qualidade da água do rio Tocantins, trecho Baião-Mocajuba (PA)
(Universidade Federal do Pará, 2024-05-27) CORDEIRO, Leonardo Corrêa; XAVIER, Diego de Arruda; http://lattes.cnpq.br/4534357826122691; https://orcid.org/0000-0003-1644-3837; SILVA, José Francisco Berredo Reis da; http://lattes.cnpq.br/1338038101910673; https://orcid.org/0000-0002-8590-2462
The water quality in hydrographic basins can be understood through studies involving physicalchemical, chemical, and biological parameters, taking into account anthropic activities and associated natural processes. The aim of this study was to analyze the behavior of physicalchemical and chemical parameters in different seasonal periods in the hydrographic basin of the Tocantins River, Baião-Mocajuba stretch, to discuss water quality based on the interaction of anthropic factors and natural processes. For this purpose, secondary data were collected, and samples were taken at two points (P1 and P2) during distinct seasonal periods (less rainy and rainy) and at mid-tide cycle (13h). The results were discussed in light of the theory regarding natural and anthropic factors in processes that may interfere with riverine hydrochemistry and water quality. Parameters such as temperature, pH, electrical conductivity, dissolved oxygen, and total dissolved solids were measured in situ, and samples were collected for the determination of chemical parameters (Fe, Mn, Pb, Cu, Cd, Se, Al, As, Ba, B, Co, Cr, Mo, Ni, V, Zn, Sr, Ti, BOD, COD, Cl, F, NO3, NO2, SO4, PO4, total nitrogen, SiO2, NH3, Ca, Mg, Na, K, P, Dissolved Organic Carbon, alkalinity, hardness). The data were analyzed using descriptive statistics, analysis of variance, correlation, and principal component analysis. The results indicate that seasonality is a factor influencing water quality parameter values, except for SO4, H4SiO4, Ba, and Sr. On the other hand, tidal effects are crucial in altering water quality parameters, especially during the less rainy period, but these alterations do not exceed the limits established by CONAMA 357/2005. Principal component analysis identified that Ca, Mg, Ba, Sr, Mn, and hardness accounted for 44.6% of water quality parameters during the less rainy period, while during the rainy period, Mg, K, Ba, hardness, Sr, Ca, Mn, Na, dissolved oxygen, and Al accounted for 47.67%. It is concluded that the Tocantins River hydrographic sub-basin has been impacted anthropogenically due to the construction of the dam and agricultural activities. Future studies are suggested to measure the effects of these activities on the water quality of the Tocantins River.
Acesso aberto (Open Access)
Geoquímica das águas do médio e baixo rio Madeira e seus principais tributários - Amazonas - Brasil
(Instituto Nacional de Pesquisas da Amazônia, 2013-12) HORBE, Adriana Maria Coimbra; QUEIROZ, Maria Mireide Andrade; MOURA, Candido Augusto Veloso; GALARZA TORO, Marco Antônio
The aim of this paper was study the water of the Madeira River and its tributaries, between the city of Humaitá and its confluence in the Amazon River. There were analyzed: pH, conductivity, turbidity, major ions, trace elements and strontium isotopes during the dry and wet seasons and also, in the transition from the wet to the dry season, throughout 2009 and 2010. The white waters from the Madeira River are bicarbonated, calcic, with pH between 5 and 6 and the ions concentrations are higher than those of the tributaries. The waters of the tributaries are black, are more acidic and are chemically heterogeneous; those from the left margin are chemically similar to the waters of Madeira River, while those from the right margin are enriched in dissolved SiO2. The concentrations of cations, Cl- and NO3- are higher during the wet season due to the contribution of soils, vegetation and the rainwater composition (Cl-), while HCO3-, SO42-, Al, Br e P are concentrated in the dry season, and their higher contents may be related to the bedrock. The higher concentrations of SiO2 and rare earth elements in both dry and wet season are related to vegetation, soil and rocks. The interaction of these factors causes the chemical heterogeneity of the water. However, the chemical similarities between the water tributaries of the left margin and the water of the Madeira River, are probably, consequence of the Andean rocks be the sources of the Cenozoic sedimentary rocks percolated by these tributaries while the chemistry water of the tributaries of the right margin are in accordance with the tectonic stability, the intense weathering and the low erosion rate of the Amazon craton.
Acesso aberto (Open Access)
Seasonality of nematode larvae in Iguanodectes spilurus (Characidae) an ornamental fish from northeastern Para, Brazil
(Instituto Nacional de Pesquisas da Amazônia, 2013-12) FUJIMOTO, Rodrigo Yudi; ANJOS, Ellem Cristina Silva dos; RAMOS, Fabrício Menezes; MARTINS, Maurício Laterça
The current study presents a parasitological survey of larval nematodes from freshwater ornamental fish Iguanodectes spilurus caught in the watercourse of the Caete River, in the northeast region of the State of Para, Brazil. A total of 176 specimens, 1.36±0.75 g weight and 5.53±0.98 cm total length, were analyzed. Nematode larvae were identified as Capillaria sp., Procamallanus sp. and Anisakidae, with prevalence of 70.45% and infection intensity ranging from 1.81 to 4.70 larvae. The highest prevalence 57.38% occurred in the liver, but no seasonality was observed, indicating high infection throughout the year. Seasonality was observed in fish parasitized in the stomach, intestine and caecum, with prevalence and mean intensity of 17.61% and 2.32 parasites, 12.5% and 1.81 parasites, 10.79% and 2.21 parasites, respectively. The highest degree of infection was observed in the rainy season, probably due to increased availability of intermediate hosts or food.