Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
J Environ Manage ; 271: 110923, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32778260

RESUMO

Increase of water erosion is one of the main problems in watersheds all over the world and directly affects soil and water resources, causing economic and environmental losses. We proposed a combination of Genetic Algorithm and Erosion/Deposition modelling to allocate vegetation zones in order to reduce soil losses within watersheds. In this study, we have used Unit Stream Power Based Erosion Deposition (USPED) model to predict the spatial distribution of erosion and sediment deposition. Based on USPED estimates, Genetic Algorithm optimize site as well size of forest restoration zones in order to reduce soil losses. Proposed approach considered watershed entirely, in a cell-level optimization, to find the best possible arrangement of forest zones. For initial scenario, soil loss estimate was 2.045,55 ton. ha-1. year-1 and after optimization we achieved 52% reduction. Optimized forest zones formed connected and compacted patches, which enable field implementation. Methodology is also applicable to other watersheds around world.


Assuntos
Conservação dos Recursos Naturais , Solo , Monitoramento Ambiental , Florestas , Alocação de Recursos
2.
PLoS One ; 14(11): e0225046, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31710656

RESUMO

PURPOSE: To compare the longevity and marginal bone loss of narrow-diameter (≤3.3-mm) versus standard-diameter implants supporting single crowns. MATERIAL AND METHODS: The MEDLINE (via PubMed), Scopus, and SciELO databases were searched for relevant publications. In addition, the scientific references provided by each of the implant companies that appeared in the search were reviewed. Intervention studies comparing longevity and bone loss between narrow-diameter and standard-diameter implants were included. RESULTS: The search was limited to in vivo studies in humans. The query returned 1931 results, of which 4 met the inclusion criteria. The implant success rate ranged from 93.8% to 100% over a maximum follow-up of 3 years, with no difference between narrow- and standard-diameter implants. Meta-analysis of all included studies showed greater bone loss in narrow-diameter implants as compared with standard ones; however, when analysis was restricted to randomized trials, no such difference was present. CONCLUSION: The meta-analysis showed no difference in longevity between narrow implants and standard implants when supporting single crowns. However, narrow-diameter implants may be associated with greater marginal bone loss. These findings should be regarded cautiously due to the short follow-up duration and methodological heterogeneity of the primary studies.


Assuntos
Perda do Osso Alveolar/patologia , Coroas/efeitos adversos , Implantes Dentários/efeitos adversos , Planejamento de Prótese Dentária , Adulto , Humanos , Pessoa de Meia-Idade , Viés de Publicação , Ensaios Clínicos Controlados Aleatórios como Assunto , Risco , Adulto Jovem
3.
J Contam Hydrol ; 219: 18-27, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30342837

RESUMO

The extensive use of pesticides in agricultural practices has been associated with human health problems and environmental contamination worldwide. Brazil is the largest consumer of pesticides in the world and Espírito Santo State stands out as the second Brazilian producer of coffee. However, there is no information about environmental impact of coffee producing at Itapemirim River Basin (IRB) region, Espírito Santo State, Brazil; hence a simple and quick method using open access softwares (AGROSCRE and ARAquá Web) to estimate surface entrainment and pesticide leaching potential was carried out. AGROSCRE evaluates the contamination risk of superficial and groundwater by Active Ingredients (AIs), using GOSS Method, GUS index and US EPA criteria, while ARAquá Web estimates AI concentrations in water resources, indicating their suitability based on water quality requirements for different uses. Regarding pesticides used in coffee plantations, there is 44.7% chance of surface water and 23.7% chance of groundwater contamination. Results showed that ametryne, cyproconazole, diuron, epoxiconazole, flutriafol, triadimenol and triazophos pose contamination risk to both surface water and groundwater in the IRB region. Of these, 10.5% of the total AIs are triazoles and fall under environmental classes II and III (Product Very/Dangerous to the Environment). The AIs ametryne, thiamethoxam, iprodione, flutriafol, triazophos, endosulfan, triadimenol, cyproconazole, diuron, pendimethalin, chlorpyrifos, copper II hydroxide, etion, epoxiconazole and paraquat dichloride, were found to be potentially toxic, presenting environmental concentrations ranging from 123.40 µg L-1 to 0.14 µg L-1, which are higher than the safety standard for potable water (0.1 µg L-1). With respect to these AIs, chlorpyrifos, ethion and triazophos showed concentrations higher than EC50 values for aquatic invertebrates and ametryne and diuron for algae. Thus, local residents and environment may be at high risk of pesticide exposure, when these AIs are used in coffee plantations next to surface water or groundwater.


Assuntos
Café , Monitoramento Ambiental , Poluentes Químicos da Água , Agricultura , Brasil , Água Potável , Monitoramento Ambiental/métodos , Água Subterrânea , Humanos , Organotiofosfatos , Praguicidas/análise , Medição de Risco , Rios , Triazóis , Poluentes Químicos da Água/análise
4.
J Environ Manage ; 217: 710-717, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29654974

RESUMO

Over the past few years, many sectors such as energy generation, industry, domestic supply, and agriculture have encountered serious environmental problems due to the lack of rainfall. Thus, the purpose of this paper is to review the current methodology of royalties distribution from Itaipu hydroelectric plant. In the proposed approach, two criteria were considered to establish the division of Itaipu royalties: (1) the relative percentage of the water flow in the generation of electricity and, (2) the relative percentage of the drop in the height of water. 62 hydroelectric plants were evaluated in this study. In 52 plants the water flow was the factor that most contributed to the generation of electricity. In 2013, 346 municipalities benefited the Itaipu royalties. With the proposed methodology, 1,327 municipalities will receive the resource, what would increase the revenue of each of these municipalities by, on average, US$ 87,436.91 per year. The methodology presented herein proposes a reduction in the environmental disparity that now exists in Brazil, through improvement to Government instruments and environmental policies. The distribution of royalties throughout the watershed can provide additional resources to support payment programs for environmental services at the state and municipality levels.


Assuntos
Agricultura , Centrais Elétricas , Brasil , Indústrias
5.
Sci Total Environ ; 605-606: 946-956, 2017 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-28693109

RESUMO

The formation of an urban heat island (UHI) is one of the most common impacts of the urbanization process. To mitigate the effects of UHI, the planning of urban forests (e.g., creation of parks, forests and afforestation streets) has been the major tool applied in this context. Thus, the aim of this study is to evaluate the spatial and temporal distribution of heat islands in Vila Velha, ES, Brazil using the mono-window algorithm. The study followed these methodological steps: 1) mapping of urban green areas through a photointerpretation screen; 2) application of the mono-window algorithm to obtain the spatial and temporal patterns of land surface temperature (LST); 3) correlation between LST and the normalized difference vegetation index (NDVI) and normalized difference build-up index (NDBI); 4) application of ecological evaluation index. The results showed that the mean values of LST in urban areas were at least 2.34 to 7.19°C higher than undeveloped areas. Moreover, the positive correlation between LST and NDBI showed an amplifying effect of the developed areas for UHI, while areas with a predominance of vegetation attenuated the effect of UHI. Urban centers, clustered in some parts of the city, received the worst ecological assessment index. Finally, the adoption of measures to guide the urban forest planning within urban centers is necessary to mitigate the effect of heat islands and provide thermal comfort in urban areas.

6.
RFO UPF ; 16(3)set.-dez. 2011.
Artigo em Português | LILACS | ID: lil-621154

RESUMO

Objetivos: O objetivo deste estudo foi avaliar, in vitro, a atividade antimicrobiana da suspensão de própolis a 5 e 10% sobre Enterococcus faecalis (ATCC 29212). Métodos: O teste de difusão em ágar e a técnica do disco foram empregados para as seguintes substâncias: (n = 19) extrato seco de própolis a 5 e 10%, clorexidina (controle positivo) e propilenoglicol (controle negativo). O diâmetro dos halos de inibição bacteriana foi medido após 24 horas. Resultados: Diferenças estatisticamente significantes foram observadas através do teste Anova (1 via) e post hoc de Tukey com nível de significância de 5% (p < 0,001). O grupo da clorexidina mostrou halos de inibição de crescimento bacteriano com média de 6,631 mm, ao passo que a própolis a 5 e 10% e o propilenoglicol não apresentaram halos. Conclusão: O extrato de própolis a 5 e 10% suspenso em propilenoglicol não evidenciou atividade antimicrobiana, in vitro, em comparação com o Enterococcus faecalis.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...