bluuebunny/crossref_metadata_2025 huggingface dataset:
Moral distress: challenges for an autonomous nursing professional practice
Authors: Barlem Edison Luiz Devos , Lunardi Valéria Lerch , Tomaschewski Jamila Geri , Lunardi Guilherme Lerch , Lunardi Filho Wilson Danilo , Schwonke Camila Rose Guadalupe Barcelos
Published: June 2013

Constantly experiencing limiting situations that hinder a professional practice coherent with its principles - of autonomy and advocacy of users' interests -, and often conditioned to experience moral distress, the nursing profession plays a prominent role in the current health model because it has the characteristic of managing the care rendered to users in a perspective of social inclusion, both in the basic health network and in hospitals. Aiming at carrying out a reflection on the nursing practice and the difficulties present in its work routine, and considering its characteristics as a profession, this article sought to make a reflection between the practice of nursing and the numerous moral challenges imposed by the routine, resulting, in many cases, in a value crisis that can reverberate directly on the quality of the service rendered, and in abandonment of the ideals of advocacy for users.
An appropriate data set size for digital soil mapping in Erechim, Rio Grande do Sul, Brazil
Authors: Caten Alexandre ten , Dalmolin Ricardo Simão Diniz , Pedron Fabrício de Araújo , Ruiz Luis Fernando Chimelo , Silva Carlos Antônio da
Published: June 2013

Digital information generates the possibility of a high degree of redundancy in the data available for fitting predictive models used for Digital Soil Mapping (DSM). Among these models, the Decision Tree (DT) technique has been increasingly applied due to its capacity of dealing with large datasets. The purpose of this study was to evaluate the impact of the data volume used to generate the DT models on the quality of soil maps. An area of 889.33 km² was chosen in the Northern region of the State of Rio Grande do Sul. The soil-landscape relationship was obtained from reambulation of the studied area and the alignment of the units in the 1:50,000 scale topographic mapping. Six predictive covariates linked to the factors soil formation, relief and organisms, together with data sets of 1, 3, 5, 10, 15, 20 and 25 % of the total data volume, were used to generate the predictive DT models in the data mining program Waikato Environment for Knowledge Analysis (WEKA). In this study, sample densities below 5 % resulted in models with lower power of capturing the complexity of the spatial distribution of the soil in the study area. The relation between the data volume to be handled and the predictive capacity of the models was best for samples between 5 and 15 %. For the models based on these sample densities, the collected field data indicated an accuracy of predictive mapping close to 70 %.
Soil functioning in a toposequence under rainforest in São Paulo, Brazil
Authors: Cooper Miguel , Medeiros João Carlos , Rosa Jaqueline Dalla , Soria José Eduardo , Toma Raul Shiso
Published: June 2013

Studies of soil-water dynamics using toposequences are essential to improve the understanding of soil-water-vegetation relationships. This study assessed the hydro-physical and morphological characteristics of soils of Atlantic Rainforest in the Parque Estadual de Carlos Botelho, state of São Paulo, Brazil. The study area of 10.24 ha (320 x 320 m) was covered by dense tropical rainforest (Atlantic Rainforest). Based on soil maps and topographic maps of the area, a representative transect of the soil in this plot was chosen and five soil trenches were opened to determine morphological properties. To evaluate the soil hydro-physical functioning, soil particle size distribution, bulk density (r), particle density (r s), soil water retention curves (SWRC), field saturated hydraulic conductivity (Ks), macroporosity (macro), and microporosity (micro) and total porosity (TP) were determined. Undisturbed samples were collected for micromorphometric image analysis, to determine pore size, shape, and connectivity. The soils in the study area were predominantly Inceptisols, and secondly Entisols and Epiaquic Haplustult. In the soil hydro-physical characterization of the selected transect, a change was observed in Ks between the surface and subsurface layers, from high/intermediate to intermediate/low permeability. This variation in soil-water dynamics was also observed in the SWRC, with higher water retention in the subsurface horizons. The soil hydro-physical behavior was influenced by the morphogenetic characteristics of the soils.
Methane efflux in rice paddy field under different irrigation managements
Authors: Moterle Diovane Freire , Silva Leandro Souza da , Moro Vagner João , Bayer Cimélio , Zschornack Tiago , Avila Luis Antonio de , Bundt Ângela da Cas
Published: June 2013

Paddy rice fields may contribute to methane (CH4) emission from soil due to anaerobic conditions after flooding. Alternatives to continuous flooding irrigation in rice have been developed to mitigate CH4 efflux into the atmosphere. This study aims to investigate the effects of irrigation managements in the CH4 efflux during the rice growing season. An experiment was carried out at in Santa Maria, Rio Grande do Sul State, Brazil, during 2007/08 and 2009/10 growing seasons. The treatments were continuous flooding and intermittent irrigation in 2007/08 and continuous flooding, intermittent irrigation and flush irrigation in 2009/10. Intermittent irrigation is effective in mitigating CH4 efflux from rice fields when climatic conditions enable water absence during cultivation, but its efficiency depends on the electrochemical soil conditions during the flooding cycles.
Lead and zinc in the structure of organic and mineral soil components
Authors: Kummer Larissa , Melo Vander de Freitas , Barros Yara Jurema
Published: June 2013

In addition to the more reactive forms, metals can occur in the structure of minerals, and the sum of all these forms defines their total contents in different soil fractions. The isomorphic substitution of heavy metals for example alters the dimensions of the unit cell and mineral size. This study proposed a method of chemical fractionation of heavy metals, using more powerful extraction methods, to remove the organic and different mineral phases completely. Soil samples were taken from eight soil profiles (0-10, 10-20 and 20-40 cm) in a Pb mining and metallurgy area in Adrianópolis, Paraná, Brazil. The Pb and Zn concentrations were determined in the following fractions (complete phase removal in each sequential extraction): exchangeable; carbonates; organic matter; amorphous and crystalline Fe oxides; Al oxide, amorphous aluminosilicates and kaolinite; and residual fractions. The complete removal of organic matter and mineral phases in sequential extractions resulted in low participation of residual forms of Pb and Zn in the total concentrations of these metals in the soils: there was lower association of metals with primary and 2:1 minerals and refractory oxides. The powerful methods used here allow an identification of the complete metal-mineral associations, such as the occurrence of Pb and Zn in the structure of the minerals. The higher incidence of Zn than Pb in the structure of Fe oxides, due to isomorphic substitution, was attributed to a smaller difference between the ionic radius of Zn2+ and Fe3+.
Phosphorus fractions in sandy soils of vineyards in southern Brazil
Authors: Schmitt Djalma Eugênio , Comin Jucinei José , Gatiboni Luciano Colpo , Tiecher Tales , Lorensini Felipe , Melo George Wellington Bastos de , Girotto Eduardo , Guardini Renato , Heinzen Janaína , Brunetto Gustavo
Published: June 2013

Phosphorus (P) applications to vineyards can cause P accumulation in the soil and maximize pollution risks. This study was carried out to quantify the accumulation of P fractions in sandy soils of vineyards in southern Brazil. Soil samples (layers 0-5, 6-10 and 11-20 cm) were collected from a native grassland area and two vineyards, after 14 years (vineyard 1) and 30 years (vineyard 2) of cultivation, in Santana do Livramento, southern Brazil, and subjected to chemical fractionation of P. Phosphorus application, especially to the 30-year-old vineyard 2, increased the inorganic P content down to a depth of 20 cm, mainly in the labile fractions extracted by anion-exchange resin and NaHCO3, in the moderately labile fraction extracted by 0.1 and 0.5 mol L-1 NaOH, and in the non-labile fraction extracted by 1 mol L-1 HCl, indicating the possibility of water eutrophication. Phosphorus application and grapevine cultivation time increased the P content in the organic fraction extracted by NaHCO3 from the 0-5 cm layer, and especially in the moderately labile fraction extracted by 0.1 mol L-1 NaOH, down to a depth of 20 cm.
Interação fosfito e fosfato no crescimento e na nutrição fosfatada do feijoeiro em solução nutritiva
Authors: Araújo Josinaldo Lopes , Faquin Valdemar , Ávila Fabrício William de , Pedroso Thiago Queiroz
Published: June 2013

O uso de fosfito como fungicida ou como fonte suplementar de fósforo (P) tem se intensificado nos últimos anos; entretanto, pouco se sabe sobre seus efeitos em culturas importantes como o feijoeiro. Objetivou-se com este trabalho avaliar o efeito da interação entre fosfito e fosfato sobre o crescimento e a nutrição fosfatada do feijoeiro. Dois experimentos foram realizados, em delineamento inteiramente casualizado em solução nutritiva, em casa de vegetação, no período de janeiro a março de 2008. No primeiro, os tratamentos foram constituídos por um esquema fatorial 5 x 2, sendo cinco concentrações de P na solução nutritiva: 0,5; 10; 20; 30; e 60 mg L-1 e duas formas de P: fosfito (Phi) e fosfato (Pi), com quatro repetições. No segundo experimento, os tratamentos foram constituídos por cinco proporções de Pi:Phi em solução nutritiva: 100:0, 75:25, 50:50, 25:75 e 0:100, com cinco repetições. Os resultados evidenciaram que as plantas cultivadas com fosfito como única forma de P, ou em elevadas proporções de Phi, apresentaram redução acentuada na matéria seca da parte aérea e de raízes, refletindo em valores desprezíveis para o acúmulo de P nesses tecidos. Da mesma forma, a atividade da enzima fosfatase ácida apresentou decréscimo com o aumento das proporções de Phi, enquanto os teores de Pi solúveis diminuíram. Concluiu-se que o fosfito não é capaz de substituir o fosfato na nutrição fosfatada do feijoeiro, tendo efeito nulo sobre o feijoeiro sob adequada disponibilidade de fosfato. Na ausência ou baixa disponibilidade de fosfato, ocorre toxicidade acentuada de fosfito no feijoeiro que se apresentou muito sensível a esse ânion.
Adubação nitrogenada para milho com o uso de plantas de cobertura e modos de aplicação de calcário
Authors: Leal Aguinaldo José Freitas , Lazarini Edson , Rodrigues Leandro Rebuá , Marcandalli Luiz Henrique
Published: June 2013

O sistema plantio direto (SPD) é uma realidade na região dos Cerrados, mas alguns questionamentos persistem nesse tipo de manejo como o modo de realização da calagem e a dose de nitrogênio (N) a ser adotada em cultura comercial, em relação às culturas precedentes. Desse modo, objetivou-se avaliar modos de aplicar o calcário na implantação do SPD e o efeito de culturas de cobertura precedentes sobre a necessidade de adubação nitrogenada da cultura do milho, durante diferentes anos agrícolas. O delineamento experimental utilizado foi de blocos casualizados, em esquema fatorial 5 x 2 (modos de aplicação do calcário x culturas de cobertura) e posterior divisão em três subparcelas, referentes às doses de N (0, 90 e 180 kg ha-1). Foram avaliados quatro modos de aplicação de calcário: incorporado a 0-0,2 m, em out./2001; dose total em superfície aplicada, em out./2001; aplicação de 1/2 da dose, em out./2001, e 1/2, em ago./2002, na superfície; e aplicação de 1/3 da dose recomendada, em mar./2001, + 1/3, em out./2001, e 1/3, em ago./2002, também em superfície. Além de um tratamento testemunha (sem calcário) e duas culturas de cobertura, crotalária e milheto. Os diferentes modos de calagem não alteraram a produtividade de grãos de milho. O cultivo de milho após crotalária apresentou melhor desempenho e menor demanda de adubação nitrogenada, quando comparado ao cultivado após milheto.
Water erosion in no-tillage monoculture and intercropped systems along contour lines
Authors: Bertol Ildegardis , Ramos Roger Robert , Barbosa Fabrício Tondello , González Antonio Paz , Ramos Julio César , Bandeira Douglas Henrique
Published: June 2013

Water erosion is the major cause of soil and water losses and the main factor of degradation of agricultural areas. The objective of this work was to quantify pluvial water erosion from an untilled soil with crop rows along the contour, in 2009 and 2010, on a Humic Dystrupept, with the following treatments: a) maize monoculture; b) soybean monoculture; c) common bean monoculture; d) intercropped maize and bean, exposed to four simulated rainfall tests of on hour at controlled intensity (64 mm h-1). The first test was applied 18 days after sowing and the others; 39, 75 and 120 days after the first test. The crop type influenced soil loss through water erosion in the simulated rainfall tests 3 and 4; soybean was most effective in erosion control in test 3, however, in test 4, maize was more effective. Water loss was influenced by the crop type in test 3 only, where maize and soybean were equally effective, with less runoff than from the other crops. The soil loss rate varied during the runoff sampling period in different ways, demonstrating a positive linear relationship between soil and water loss, in the different rainfall tests.
Surgical research in the north and northeast of Brazil
Authors: Araújo Rafael Silva de , Brito Felipe Nunes , Chaves Yan , Veiga Daniela Francescato , Ferreira Lydia Masako
Published: June 2013

PURPOSE: To evaluate the scientific production from the surgical areas from the State University of Para (UEPA), Federal Universities of Para (UFPA) and of Paraiba (UFPB), Brazil. METHODS: The scientific productions of professors in the last five years were classified according to the Qualis system of CAPES-Medicine III (http://qualis.capes.gov.br/webqualis/publico/pesquisaPublicaClassificacao.seam?conversationPropagation=begin) and it was computed the number of guidance of students scientific projects. RESULTS: Seventy-four professors were included, 31 with Master and 43 with PhD degrees. UFPA presented more publications (49% out of the total), which 32% of them in Journals B1 or higher. Otorhinolaryngology presented the greatest number of publications (29% out of the total); however, 98% of them in B3 or lower. Gastroenterological Surgery, which is responsible for 23% out of the total, had 57% of its publications in B1 or higher. The most frequent type of guidance was the one about scientific work of completion of undergraduate course (63%). Gynecology and Obstetrics presented the greatest number of student's guidance (35% out of the total) and Gastroenterological Surgery the largest number of Master's degree and PhD degree supervisions. CONCLUSIONS: The specialties Gynecology and Obstetrics and Gastroenterological Surgery from the State University of Para (UEPA), Federal Universities of Para (UFPA) and of Paraiba (UFPB) presented the greatest number of professors with academic degrees. Gastroenterological Surgery presented the largest scientific productions at higher strata of WebQualis CAPES classification and also the largest number of Master and PhD directed.
Efeitos da aplicação da EPAP (Expiratory Positive Airway Pressure) sobre a tolerância ao esforço em pacientes portadores de insuficiência cardíaca
Authors: Thofehrn Claudia , Coutinho Mario Sérgio Soares de Azeredo , Daros Clarissa Borguezan , Assis Amberson Vieira de , Lima Renata Moraes de , Bonin Christiani Decker Batista , Benetti Magnus
Published: June 2013

INTRODUÇÃO: Novas abordagens terapêuticas que objetivam melhorar a sensação de dispneia e fadiga em pacientes com insuficiência cardíaca, como a aplicação de pressão positiva expiratória nas vias aéreas (EPAP), podem ser aplicadas na tentativa de melhorar a capacidade funcional e a qualidade de vida. OBJETIVO: Avaliar os efeitos da utilização da EPAP ( Expiratory Positive Airway Pressure) durante o esforço em indivíduos portadores de IC classe funcional II e III (NYHA). MÉTODOS: Dos 390 pacientes, foram selecionados 28 com FEVE < 40%. O Teste de Caminhada de seis minutos (TC6') foi realizado três vezes: o primeiro para a familiarização, um com a máscara e o outro sem a máscara de EPAP, sendo válido os dois últimos. A comparação entre os dados obtidos foi realizada por meio de teste t de Student pareado ou teste de Wilcoxon, conforme a normalidade dos dados. RESULTADOS: a percepção de esforço foi maior após a caminhada com a utilização da máscara quando comparado na ausência da máscara. Houve elevação significativa na saturação de oxigênio quando os pacientes estavam usando a máscara de EPAP. CONCLUSÃO: O uso da máscara de EPAP aumenta a percepção de esforço e o trabalho ventilatório, porém, não aumentou a distância percorrida no TC6, sendo sua aplicabilidade questionável em programas de reabilitação cardiovascular.
Exercício físico controla pressão arterial e melhora qualidade de vida
Authors: Bündchen Daiana Cristine , Schenkel Isabel de Castro , Santos Rafaella Zulianello dos , Carvalho Tales de
Published: June 2013

INTRODUÇÃO: Para o tratamento correto da hipertensão arterial, é plausível a hipótese de que diante da prática regular de exercícios físicos estes pacientes não necessitariam de fármacos anti-hipertensivos. OBJETIVO: Avaliar o efeito do tratamento exclusivo com exercício físico na pressão arterial (PA) e qualidade de vida (QV) de hipertensos. MÉTODO: Ensaio clínico com 32 hipertensos sedentários, 55±9 anos, que estavam sob tratamento farmacológico (TF) aleatoriamente alocados em Grupo Exercício (GE) e Grupo Controle (GC). No GE, 18 indivíduos (50% mulheres) após pelo menos dez dias de interrupção do TF iniciaram programa de exercício de dez semanas, 3x/semana, 30 minutos de exercício aeróbio seguidos por exercícios resistidos, enquanto 14 do GC (57% mulheres) se mantiveram sob TF. Foi verificada PA sistólica (PAS) e diastólica (PAD) no início e final do estudo pelo método auscultatório clássico e QV pelo questionário MINICHAL. Os dados foram expressos por M±DP, usou-se teste t de Student, U de Mann-Whitney e Wilcoxon, considerando-se p < 0,05 significativo. RESULTADOS: No início e final da pesquisa, não foram observadas diferenças na PA entre os grupos. Intragrupos, a PA no GE manteve-se semelhante aos valores antes da retirada dos fármacos (PAS 132,2 ± 13,3 x 134,4 ± 10 mmHg; PAD 85,0 ± 9 x 85,3 ± 10 mmHg p = ns), assim como no GC (PAS 127,2 ± 19 x 130,2 ± 16 mmHg; PAD 82,1 ± 16 x 85,3 ± 12 mmHg p = ns). Para a QV, entregrupos não foi observada diferença dos escores no início e final, intragrupos melhora significativa no aspecto emocional do GE (p = 0,02). CONCLUSÃO: A terapêutica anti-hipertensiva, exclusivamente por meio do exercício físico na comparação com tratamento farmacológico convencional, possibilitou idêntico controle da PA e melhor percepção de QV.
Taxa metabólica basal de homens residentes na cidade de Goiânia
Authors: Lustosa Arícia Motta Arantes , Bento Ana Paula Nunes , Barbosa Fernando Policarpo , Soares Eliane De Abreu , Dantas Estélio Henrique Martin , Fernandes Filho José
Published: June 2013

INTRODUÇÃO: A Taxa Metabólica Basal (TMB) é a quantidade de energia necessária para o corpo humano manter os processos fisiológicos normais e a homeostase. Atualmente, a TMB é calculada a partir de equações baseadas na população norte-americana e/ou europeia. OBJETIVO: Comparar as equações de Harris-Benedict, Food and Agriculture Organization e Institute of Medicine com a calorimetria indireta em indivíduos do sexo masculino residentes na cidade de Goiânia. MÉTODOS: A determinação da TMB foi feita pela análise direta de gases, utilizando o analisador VO2000. Foram avaliados 44 voluntários do sexo masculino, com média de idade 29,8 anos (Desvio padrão - DP = 6,21), estatura 1,79 m (DP = 0,06), peso 77,79 kg (DP = 8,49), IMC 24,30 kg/m2 (DP = 1,96), gordura corporal 15,84% (DP = 4,49), circunferência da cintura 80,48 cm (DP = 5,89). RESULTADOS: Foi observada diferença significante (p < 0,05) para os valores da TMB estimada pelas equações de Harris-Benedict (1.824,7, DP = 138,2 kcal/dia) e Food and Agriculture Organization (1.821,8, DP = 115,4 kcal/dia), quando comparado ao valor obtido pela calorimetria indireta (1.709,8, DP = 329,7 kcal/dia). Esse valor não foi significantemente diferente do obtido pela equação do Institute of Medicine (1.791, DP = 329 kcal/dia). CONCLUSÃO: As equações Harris-Benedict e Food and Agriculture Organization podem superestimar a TMB de homens jovens, sadios, com características semelhantes as do presente estudo. As equações do Institute of Medicine, por sua vez, resultam em valores estimados de TMB mais próximos aos mensurados.
Morbidade hospitalar por ingestão de esteroides anabólico-androgênicos (EAA) no Brasil
Authors: Silva Junior Sérgio Henrique Almeida da
Published: June 2013

INTRODUÇÃO: Os esteroides anabólico-androgênicos (EAA) são hormônios sexuais masculinos, promotores e mantenedores das características sexuais associadas à masculinidade e do status anabólico dos tecidos somáticos. Os efeitos físicos e mentais do uso abusivo de EAA são raros e é praticamente impossível afirmar com certeza quais os efeitos adversos que poderão tornar-se evidentes após a autoadministração, mas os mesmos constituem risco de morte para os indivíduos. OBJETIVO: O objetivo do presente estudo foi descrever as principais características da morbidade por ingestão de EAA no Brasil, no período de 2000/2010. MÉTODOS: As informações sobre as internações hospitalares foram obtidas dos bancos de dados informatizados do Ministério da Saúde. Na análise da ingestão de EAA como diagnóstico principal e secundário de hospitalização, partiu-se das causas de internação sob os códigos E28.1 (excesso de andrógenos), E34.5 (síndrome de resistência a andrógenos), T38.7 (intoxicação por andrógenos e anabolizantes congêneres) e Y42.7 (efeitos adversos de andrógenos e anabolizantes congêneres) do CID-10. RESULTADOS: As hospitalizações por EAA foram responsáveis por 0,001% do total de internações do País. Foram contabilizadas 1.319 internações (média = 119,9, DP = 99,01). A síndrome de resistência a andrógenos foi a principal causa, correspondendo a 55,8% do total de internações. Do total de internações, 1% dos pacientes evoluiu para óbito e o tempo máximo de permanência foi de 47 dias (média = 3,8 e DP = 4,7). Minas Gerais, Maranhão e Espírito Santo possuíram as maiores taxas de internações por 1.000.000 de habitantes, nos anos de 2002 a 2007. As mulheres e a faixa etária de 15-29 tiveram maiores taxas, 82,5% e 37,7%, respectivamente. CONCLUSÃO: Os resultados do presente estudo mostraram uma hospitalização por ingestão de EAA relativamente baixa, as mulheres e indivíduos na faixa etária de 15-29 anos possuíram as maiores taxas no período estudado.
Reconstruction of the Premaxilla by Segmental Distraction Osteogenesis for Maxillary Retrusion in Cleft Lip and Palate
Authors: Kim Bong Chul , Lee Sang-Hwy , Park Kyung-Ran , Jung Young-Soo , Yi Choong-Kook
Published: June 2013

We present a strategy to target one of the main areas causing retruded maxilla, the premaxillary region for patients with cleft lip and palate (CLP). Advancement of the premaxilla by distraction osteogenesis is attempted, and the retruded anterior maxilla, the collapsed dental space, and the arch shape are sufficiently improved. This strategy also prevents deterioration of the velopharyngeal incompetency function. The procedure seems to be a good option for the treatment of maxillary retrusion and malocclusion for CLP.
Design of a sand filter for highway runoff in the north of Spain
Authors: Suárez Joaquín , Jiménez Vicente , del Río Hector , Anta Jose , Jácome Alfredo , Torres Daniel , Ures Pablo , Vieito Sara
Published: June 2013

Urban and highway runoff has negative environmental and ecological effects on the waters that receive it. Highway runoff mobilises heavy metal elements and suspended solids from atmospheric deposition and traffic, as well as road degradation and maintenance. A pilot sand filter is designed to reduce metals, hydrocarbons and suspended solids from a highway reach in Fene, Spain. This unit filters a percentage of highway runoff, reducing the mobilised loads of pollutants through filtration and sorption. A monitoring programme is developed to characterise runoff pollution of the pilot catchment. Runoff is found to be heavily polluted with sediments, high chemical oxygen demand, total phosphorus, copper and zinc. Field data are also used to develop a calibrated hydraulic model of the catchment with the storm water management model. From the long-term simulations using this model, the filtration device is designed for an average spill frequency of about 20 events per year and to capture and treat approximately 90% of the average annual stormwater runoff.
Storm-water management in low-income countries
Authors: Reed Brian
Published: June 2013

Rapid urbanisation coupled with a changing climate is increasing surface run-off in many cities in low-income countries. Badly managed run-off has a disproportionate impact on the poor. In a series of ten research projects the state of storm-water management in Vietnam, Nigeria, Uganda, Kenya, Pakistan and India has been examined, including issues of management, maintenance, health impacts (such as malaria) and design standards. The findings show that institutional issues such as urban planning, financing, management responsibility and skills levels are areas that require attention if storm-water is to be controlled effectively. Integrated approaches are required, making institutional coordination critical. Technical issues also need to be addressed, with silt and solid waste being a significant design problem.
Creating a water-sensitive north-west Cambridge master plan
Authors: Morgan Celeste , Woods Ashley
Published: June 2013

An integrated approach to water management and urban design has actively been sought in the development of the master plan for a major urban extension in north-west Cambridge. A multidisciplinary team of urban designers, landscape architects, engineers, ecologists and planners have developed a water-sensitive urban design strategy for the site. From the concept stage, integrated sustainable drainage measures and extensive green corridors have been integrated into the site, to treat and store surface water above ground while also supporting urban design and place-making aspirations. A site-wide strategy for water management is also being developed to utilise opportunities to integrate the entire water cycle and progress towards water neutrality, including consideration of site-wide wastewater recycling for non-potable reuse; site-wide stormwater harvesting, using sustainable urban drainage systems features to filter water for non-potable reuse; and specifications for water efficiency in buildings and the landscape. The case study demonstrates how the consideration of water management upfront can be used to shape the spatial layout, utilities and infrastructure strategies, and the urban design vision for new development.
Coupling utility performance targets with catchment management
Authors: Ezeji Joachim Ibeziako , Smout Ian , Bosher Lee
Published: June 2013

Institutional reform of state-owned water utilities serving urban areas has often set out to turn them into effective and efficient organisations, so that they can become excellent service providers. However, the pursuit of such objectives, which are often based on commercial targets, woefully ignores efficient catchment management. In view of this, this study reviews the case of the Cross State Water Board (CRSWB) Ltd in Calabar, eastern Nigeria. It identifies the serial neglect of the local watershed as a factor responsible for its operational and maintenance costs. It therefore argues for the need to develop and integrate catchment or ecosystem indicators into overall performance indicators currently used in setting and monitoring performance by the water utility as well as other utilities elsewhere, their owners or regulators. Such socio-ecological considerations as manifest in a catchment, according to the paper, are vital in building appropriate resilience against hazard risks such as flooding, land erosion, land inundation and salt water intrusion which currently plague the CRSWB, hence offering a bold and sustainable road map towards service efficiency and effectiveness for the growing urban population under a variable climate.
A native fungal symbiont facilitates the prevalence and development of an invasive pathogen–native vector symbiosis
Authors: Zhao Lilin , Lu Min , Niu Hongtao , Fang Guofei , Zhang Shuai , Sun Jianghua
Published: June 2013

Invasive pathogen–insect symbioses have been extensively studied in many different ecological niches. Whether the damage of symbioses in different introduced regions might be influenced by other microorganisms has, however, received little attention. Eight years of field data showed that the varied levels of the nematode and beetle populations and infested trees of the invasiveBursaphelenchus xylophilus–Monochamus alternatussymbiosis were correlated with patterns in the isolation frequencies of ophiostomatoid fungi at six sites, while the laboratory experiments showed that the nematode produced greater numbers of offspring with a female‐biased sex ratio and developed faster in the presence of one native symbiotic ophiostomatoid fungus,Sporothrixsp. 1. Diacetone alcohol (DAA) from xylem inoculated withSporothrixsp. 1 inducedB. xylophilusto produce greater numbers of offspring. Its presence also significantly increased the growth and survival rate ofM. alternatus, and possibly explains the prevalence of the nematode–vector symbiosis whenSporothrixsp. 1 was dominant in the fungal communities. Studying the means by which multispecies interactions contributed to biogeographical dynamics allowed us to better understand the varied levels of damage caused by biological invasion across the invaded range.
Habitat loss alters the architecture of plant–pollinator interaction networks
Authors: Spiesman Brian J. , Inouye Brian D.
Published: June 2013

Habitat loss can have a negative effect on the number, abundance, and composition of species in plant–pollinator communities. Although we have a general understanding of the negative consequences of habitat loss for biodiversity, much less is known about the resulting effects on the pattern of interactions in mutualistic networks. Ecological networks formed by mutualistic interactions often exhibit a highly nested architecture with low modularity, especially in comparison with antagonistic networks. These patterns of interaction are thought to confer stability on mutualistic communities. With the growing threat of environmental change, it is important to expand our understanding of the factors that affect biodiversity and the stability of the communities that provide critical ecosystem functions and services. We studied the effects of habitat loss on plant–pollinator network architecture and found that regional habitat loss contributes directly to species loss and indirectly to the reorganization of interspecific interactions in a local community. Networks became more highly connected and more modular with habitat loss. Species richness and abundance were the primary drivers of variation in network architecture, though species compositi n affected modularity. Theory suggests that an increase in modularity with habitat loss will threaten community stability, which may contribute to an extinction debt in communities already affected by habitat loss.
A Chemical Inhibitor-Infused, High-Strength Proppant Additive for Reservoir Flow Assurance against Scale Deposition in Wells with High Intervention Costs
Authors: Gupta D. V. , Shen Dong , Szymczak Stephen J.
Published: June 2013

If only oil and gas wells produced problem free, then flow assurance strategies would become unnecessary. The reality is that problems such as inorganic and organic deposition in the formation, the near wellbore, and the tubulars complicate and add expense to the completion and production processes. In 2005, a technology was introduced by which chemical inhibitors were adsorbed onto a proppant-like substrate and placed in the formation during hydraulic fracture. Since then more than 15,000 wells have been fractured using this solid chemical technology. Upon production of hydrocarbon or water, the requisite inhibitor is released into the fluid stream to inhibit the deposition of contaminants such as scale, paraffin or asphaltenes. However, the strength of the solid substrate limits the amount of material added and the closure pressure applied. This paper discusses a new material that demonstrates no conductivity loss when added at up to 20% by weight to high-strength (bauxite) proppant and up to 16,000 psi closure stress. Furthermore, it maintains chemical adsorptivity similar to the earlier material. For deepwater wells, which are traditionally gravel-packed or frac-packed, the new material can provide multi-year inhibitor life to delay or eliminate future interventions. This represents a significant savings on projected expenditures as well as an ongoing flow assurance program that protects against scale deposition from the formation to the surface.
A Fracturing Driven Approach: Main Challenges and Lessons in Developing a Tight Gas Reservoir in Argentina
Authors: Schnaidler Gabriel , Medina Hernán Villada , Alric Facundo , Goiran Pierre-Olivier
Published: June 2013

Total E&P is currently operating a tight gas field in Argentina, consisting of a low permeability and heterogeneous sandstone under hydrostatic pressure regime.

The field is mainly developed with casing-cemented horizontal multi-frac wells at 1700 m TVD and 3000 m MD and vertical wells targeting the same depth.

Numerous technical drawbacks were faced at the beginning of field development, threatening the chances of producing commercial rates and eventually locking a projected campaign. As a result, innovative solutions in terms of stimulation and reservoir evaluation techniques had to be deployed in order to achieve sustained productivity.

After performing more than 200 fracture treatments in 10 multi-frac horizontals plus 50 vertical wells, several key lessons were capitalized in the field of;

Fracture design, including proppant selection and the application of ultra light weight proppants A new approach in permeability assessment allowing completion optimization of horizontal wells Horizontal drain vertical placement in a thick reservoir

One relevant step in the process was, in addition, learning to manage reservoir free water production by introducing the appropriate artificial lift techniques.

This paper summarizes the main challenges, milestones and lessons captured in the completion and productivity domain that finally enabled a cost effective field development.
A Porosity-Fill Sealant for Water and Gas Shutoff: Case Histories and Lessons Learned after more than 1,000 Well Interventions
Authors: Vasquez Julio , Curtice Richard
Published: June 2013

A wide variety of mechanical and chemical technologies have been implemented for controlling unwanted fluid production in hydrocarbon-producing wells. This paper presents the field implementation of a porosity-fill sealant (PFS) system for water and gas shutoff applications. Proper diagnostics and candidate selection process is the key to a high success ratio with this type of treatment. Case histories are presented along with lessons learned from more than 1,000 treatments highlighting the diagnostic stage.

The PFS system is based on a copolymer of acrylamide and t-butyl acrylate (PAtBA) crosslinked with polyethyleneimine (PEI). The PFS system is placed into the formation as a low-viscosity solution that eventually actives at a predicted time to form a three-dimensional (3D) gel structure. The crosslinked gel provides a total shutoff of pore spaces and channels, thus limiting undesired water or gas flow. The PFS is not a selective treatment; thus, zonal isolation might be required. The working temperature range of this system is 40 to 400°F. This system has been successfully tested to withstand a differential pressure of at least 2,600 psi and is resistant to acid, CO2, and H2S environments. The following parameters are discussed: (1) PFS performance testing, (2) design considerations, and (3) case histories.

To date, more than 1,000 treatments have been performed with the PFS system worldwide to address conformance problems, such as water coning/cresting, high-permeability streaks, gravel-pack isolation, fracture shutoff, and/or casing-leak repair. Because of the capability of the PFS system to withstand high-pressure environments, workover operations have been successfully performed in previously treated wells, including acid stimulation, sand control, and frac-pack treatments, among others. Case histories are presented for different types of water production mechanisms and different wellbore completions and reservoir conditions where the PFS system was successfully implemented.
Performance and Formation Damage Assessment of a Novel, Thermally Stable Solids-Free Fluid Loss Gel
Authors: Gamage Pubudu , Deville Jay P. , Shumway Bill
Published: June 2013

The leakage of reservoir fluids into a wellbore during perforation, workover, or other completion operations is a substantial concern, especially in high temperature wells where existing fluids utilized to mitigate reservoir fluid influx offer poor performance. To maintain the hydrostatic integrity of the wellbore during these operations, a thermally-stable, solids-free fluid loss pill has been developed.

The pill is composed of synthetic polymers and cross-linkers in monovalent high-density brine. Under ambient pressure and temperature conditions, the pill flows as a viscous liquid and remains fluid for over six months. Upon exposure to elevated temperatures (200°F to 375°F), the pill cross-links to form a robust gel that can act as an appropriately-weighted, low fluid loss pill. This pill can temporarily seal the reservoir, enabling well control during completion operations.

Gelled samples of the fluid loss pill have maintained integrity for up to three weeks under HTHP conditions in laboratory testing with minimal signs of collapse. Fluid loss tests at different temperatures were conducted to assess the fluid loss performance. Gel could be easily removed without a breaker by the formation pressure of the reservoir upon well completion due to the solids-free nature and lower lift-off pressures required for this particular gel. However, depending on the specific requirements for a formation, this gel could be readily destroyed with high temperature oxidative breaker systems. In such circumstances, the timing of gel removal could be completely controlled by the timing of the breaker addition.

The gel was also evaluated for any formation damage issues if used in a high temperature gas reservoir by using regain permeability experiments with Berea sandstone cores. Necessary precautions were taken to eliminate the permeability impairment effects caused by the change in water saturation of the tested core.

Average fluid loss in the core flooding test over 3 days at 320 °F was about 50 ml. Restoration of the Berea core permeability after the treatment exceeded 95% of the initial permeability with low lift-off pressures observed. This paper presents full laboratory data on the fluid loss performance and regain permeability of a novel thermally-stable, solids-free fluid loss gel.
Fines Migration in Fractured Wells: Integrating Modeling, Field and Laboratory Data
Authors: Marquez M. , Williams W. , Knobles M. , Bedrikovetsky P. , You Z.
Published: June 2013

Production and drawdown data from ten subsea deepwater fractured wells have been modeled using an analytical model for unsteady state flow with fines migration. The simulation results and the field data indicated a good match within five percent. A sensitivity study conducted on initial concentration of fines, flow rate, maximum fines mobilization velocity, fines distribution, formation damage and filtration coefficients confirmed that the model matching parameters are within values commonly reported in the literature. This paper describes the methodology used to integrate the modeling predictions with field and laboratory data to identify probable causes for increasing skins and declining productivity index (PI) values observed in some of the wells under investigation. It discusses the results of an experiment designed to simultaneously assess the effects of pressure depletion and compaction on fines production and permeability using a triaxial stress apparatus. This is, to the best of our knowledge, the first time an experiment of this nature is reported in the literature. The good match between the modeling and the field data, further validated with laboratory experiments, allows for discussion of long term predictions on well productivity impacting current reservoir management strategies and field development plans.
Modeling Formation Damage and Completion Geometry in an Old Well Enables Better Planning for New Wells - Gyda Development Case Study
Authors: Byrne M. , Rojas E. , Holst V. B.
Published: June 2013

Gyda is a mature oil development in the Norwegian sector of the North Sea. The first production wells were drilled more than twenty years ago. This study focuses on wells drilled in the porer reservoir quality areas of the Gyda reservoir. Some recent production wells have significantly underperformed relative to equivalent initial wells. In particular, a sidetrack to an early successful well, had very poor performance on initial start-up.

The geometry of the original well and the sidetrack were simulated, together with various assumptions and sensitivities to formation damage. In the original well an attempted hydraulic fracture had been assumed to have failed. This assumption was challenged in the model.

The model demonstrated that the original well must have included a successful hydraulic fracture in order to flow at the historical rates recorded. In addition for the sidetrack, that contained no fracture, there were indications that the perforation tunnels may not have fully cleaned up and that whilst the well performance may recover somewhat with time, a significant change in completion would be required in order to match the performance of the original well.

The model constructed included the completion geometry and formation damage and has enabled evaluation of old wells and more importantly, design of new wells in this mature reservoir development.
Residue-Free Fracturing Fluid Provides Superior Cleanup and Exceptional Proppant Transport
Authors: Schultheiss Nathan , Fontenelle Lucas , Welton Thomas
Published: June 2013

Currently, guar-based fluid systems are the preferred choice for hydraulic fracturing operations, primarily because the fluid formulations can be widely varied depending on reservoir conditions and operational needs. However, fluids prepared with guar are inherently dirty and contain water-insoluble residues, which can significantly reduce the permeability of the proppant pack when flowing back and producing the well. This can result in a possible reduction in overall hydrocarbon production. Herein, a new, residue-free, hydraulic fracturing fluid system has been developed that provides excellent performance during the fracturing process and includes superior cleanup characteristics.

The "res-free" fluid is a premium fracturing fluid with comparable, or improved, properties compared to a typical guar/borate crosslinked system. First, because the fluid does not generate insoluble residue on breaking, excellent regained conductivity and core permeability can be achieved, which has been demonstrated both in laboratory testing and in the field by measuring well productivity. Second, the fluid is robust, allowing for precise viscosity and breaker control. Third, the fluid is salt tolerant and is usable up to temperatures of 275°F. Finally, it is capable of providing excellent proppant-carrying characteristics. The proppant-transport characteristics of this fluid are comparable to other fluids in use, as measured by a slurry viscometer. This paper highlights regained conductivity and core permeability, rheological performance, and proppant-transport characteristics of the new fluid and provides comparative guar-based fluid data. This new, residue-free fluid is applicable to fracturing a wide variety of reservoirs, including unconventional reservoirs, and has been used successfully in over 180 wells (>2,250 stages/zones) at temperatures up to 300°F bottomhole static temperature (BHST). Future papers will present case studies of jobs and will provide production and well performance results.
Mitigating Borehole Instability and Formation Damage with Temporary Shielding Drilling Fluids in Low Permeability Fractured Reservoirs
Authors: You Lijun , Kang Yili , Li Xiangchen , Zhou Guangqing
Published: June 2013

Along with the increasingly deep wells and long horizontal wells, the wellbore instability and formation damage undeniably becomes the biggest concerns during well construction. Sha 3 reservoirs in faulted B Depression, a low permeability exploration target zones, are highly fractured. Most of the wells with the barefoot interval length of over 2000m or even about 3500m were drilled under underbalanced conditions to improve exploration success rate. The exploration results were disappointing. Shale sloughing and borehole enlargement frequently occurred during the process of previous drilling, followed by some troubles including serious formation damage. Different kinds of drilling fluid techniques, including the nano-emulsion drilling fluid, polymeric alcohol and potassium formate, were tried to settle these problems with mixed results. Mineral analysis, shale dispersion and swelling test, and dynamic leakoff tests show that the solid particles mismatching well with the sizes of pore throats and the width of natural fractures and the high pH value of drilling fluids are two key factors triggered the borehole instability and formation damage. Based on the temporary shielding theory, the modified drilling fluids are developed by adding fibrous bridging agents and by decreasing pH value. Dynamic leakoff tests manifest that the modified drilling fluids are able to rapidly seal the micro fractures and pore throats and the percentage of regained permeability can reach more than 85%. Two experiment wells, a vertical well and a sidetracked well, located in an area of severe shale sloughing, were drilled with the modified drill fluids under micro overbalanced conditions. The results indict that the diameters of two boreholes are near-gauge, that the coring, well logging and completion operations are conducted very successfully, and that the well construction time is cut down by 50% compared with that of previous drilled wells.