bluuebunny/crossref_metadata_2025 huggingface dataset:
Os Suplementos Saúde na Pesquisa Nacional por Amostra de Domicílios (PNAD) no Brasil
Authors: Travassos Claudia , Viacava Francisco , Laguardia Josué
Published: May 2008

As mudanças socioeconômicas, demográficas e tecnológicas e suas implicações nas políticas públicas demandam dos órgãos governamentais a produção de informações. As informações atualizadas de base populacional e de âmbito nacional são essenciais ao processo de planejamento e ao acompanhamento pela sociedade do cumprimento dos princípios constitucionais da saúde, como direito ao acesso igualitário aos serviços de saúde. A Pesquisa Nacional por Amostra de Domicílios (PNAD) é uma fonte de dados importante para o conhecimento e monitoramento de aspectos relevantes da situação de saúde da população brasileira e do acesso, utilização e financiamento de serviços de saúde. Neste artigo, faz-se um breve histórico da evolução dos objetivos, da periodicidade e da abrangência geográfica ao longo de quatro décadas da PNAD no Brasil, enfatizando-se os principais aspectos incluídos nos suplementos de saúde em 1981, 1986, 1998 e 2003. A produção de textos técnicos e acadêmicos, gerados a partir desses suplementos, tem permitido conhecer aspectos importantes da saúde da população brasileira e monitorar, em diferentes recortes geográficos e socioeconômicos, as políticas voltadas para o acesso e uso de serviços de saúde. Argumenta-se sobre a necessidade de iniciar uma discussão mais profunda sobre a continuidade da série histórica iniciada em 1998, frente à implantação, em futuro próximo, do Sistema Integrado de Pesquisas Domiciliares (SIPD) pelo IBGE.
O Mestrado do Programa de Pós-graduação em Epidemiologia da UFPel baseado em consórcio de pesquisa: uma experiência inovadora
Authors: Barros Aluísio J. D. , Menezes Ana Maria Baptista , Santos Iná S. , Assunção Maria Cecília F. , Gigante Denise , Fassa Anaclaudia Gastal , Marques Margarete , Araújo Cora , Hallal Pedro C. , Facchini Luiz Augusto
Published: May 2008

O Programa de Pós-graduação em Epidemiologia da UFPel realizou um intenso trabalho de auto-avaliação para resolver problemas identificados com seu curso de mestrado. O resultado foi a introdução de uma estrutura curricular baseada em dois pilares. De um lado, disciplinas de cunho teórico, fornecendo a base da formação do mestrando; de outro, disciplinas de cunho prático, onde os alunos trabalham coletivamente a construção de seu projeto de pesquisa, passando pela escolha de um tema, revisão da literatura, definição de objetivos e da metodologia. Esse esforço conjunto culmina na realização de um trabalho de campo único, na forma de um estudo transversal de base populacional, em que todos os mestrandos participam de maneira integral, obtendo dados para sua dissertação. Essa estratégia tem garantido a formação de mestres em epidemiologia com forte base teórica e com experiência de preparação e condução de um trabalho de campo. Além disso, tem sido possível manter um tempo de titulação abaixo de 24 meses. Cerca de 80% dos egressos têm publicado pelo menos um artigo baseado em seu mestrado. Destas publicações, quase 90% têm se dado em periódicos classificados como Internacional-A no Qualis da Capes.
Species richness and geographic distribution of the genera Chydorus and Pseudochydorus (Cladocera, Chydoridae) in São Paulo State
Authors: Santos-Wisniewski Maria José , Rocha Odete , Guntzel Adriana Maria , Matsumura-Tundisi Takako
Published: May 2008

The Chydorus and Pseudochydorus genera are widely distributed around the world. Some species of Chydorus are among the commonest anomopods and Pseudochydorus globosus, the only species of the genus, is believed cosmopolitan. This study was part of the project " Zooplanktonic biodiversity and state of degradation of continental water ecosystems in São Paulo State" , itself a part of the FAPESP/BIOTA Program - The Virtual Institute of Biodiversity (www.biotasp.org.br), the aim being to make an inventory and analyze the distribution of species of the genera Chydorus and Pseudochydorus in São Paulo State, Brazil. In total, 373 samples were collected from 223 water bodies in the Water Resources Management Units of São Paulo State, between 9/9/1999 and 8/28/2002. The sampled sites varied from small streams, rivers, ponds, lakes up to big reservoirs. Six species of the genus Chydorus and one of the genus Pseudochydorus were recorded. The most common and widely distributed species were Chydorus eurynotus and Chydorus pubescens. The species Chydorus parvireticulatus occurred only in one Water Resources Management Unit of the state, and constituted the first recorded of this species in São Paulo State.
Morfologia bucal interna dos girinos de Leptodactylus labyrinthicus Spix, 1824 (Amphibia: Anura: Leptodactylidae)
Authors: Miranda Núbia , Ferreira Adelina
Published: May 2008

A microanatomia do disco oral e da cavidade bucal da larva de Leptodactylus labyrinthicus é descrita e comparada com outras espécies do gênero pertencentes ao grupo de L. pentadactylus. Trinta e cinco girinos entre os estágios 25 e 46 foram dissecados e analisados em microscopia eletrônica de varredura. A descrição da morfologia oral foi feita utilizando larvas entre os estágios 36 e 39. A morfologia oral da larva de L. labyrinthicus é similar às descritas para outros girinos com adaptação a macrofagia, com forte queratinização das coberturas das mandíbulas, redução das estruturas bucais internas e presença de uma glote descoberta, propícias às dietas carnívoras. As larvas do grupo de L. pentadactylus compartilham essa tendência à redução das estruturas de seleção e captura de partículas, apresentando redução no número de papilas da arena do assoalho e do teto bucal, redução ou ausência das papilas anteriores às bolsas bucais, apenas duas papilas pós-nasais, pequenas papilas laterais à crista mediana e zonas glandulares restritas a estreitas faixas no bordo velar. Nos girinos do gênero Leptodactylus a morfologia larvária reflete os grupos atuais propostos para o gênero.
A novel driving method and device to reduce color breakup in color‐sequential displays
Authors: Pan Ding‐Hsiang , Chang Shun‐De , Hu Kuo‐Jui , Huang Jih‐Fon , Tsai Yu‐Sheng
Published: May 2008

Abstract— Color‐sequential displays offer a better luminous efficiency, a higher spatial resolution, and a lower cost than conventional displays. However, a common problem is that visual effects cause color edge‐blurring of a moving picture, a phenomenon called color breakup or rainbow effects. Most driving methods, such as increasing the frame rate and inserting a black/white frame or another color sub‐frame to reduce the color breakup in color sequential displays has been presented in many papers, but every method has some limitations and problems. An innovative driving method and device to reduce the color‐breakup phenomenon will be demonstrated in this paper, designed without increasing the driving frequency. Instead, the brightness is increased by one third at the very least. Our method divides the driving frequency into four sub‐frames (WRGB), which is operated at 180 Hz compared to 240 Hz for conventional driving. Our result shows that the image quality is improved. The color‐breakup simulation based on “eye trace integration” and compensated white light will also be presented in this paper.
Effects of functionalized and nonfunctionalized single-walled carbon nanotubes on root elongation of select crop species
Authors: Cañas Jaclyn E , Long Monique , Nations Shawna , Vadan Rodica , Dai Lenore , Luo Mingxiang , Ambikapathi Ramya , Lee E. Henry , Olszyk David
Published: May 2008

Single-walled carbon nanotubes have many potential beneficial uses, with additional applications constantly being investigated. Their unique properties, however, create a potential concern regarding toxicity, not only in humans and animals but also in plants. To help develop protocols to determine the effects of nanotubes on plants, we conducted a pilot study on the effects of functionalized and nonfunctionalized single-walled carbon nanotubes on root elongation of six crop species (cabbage, carrot, cucumber, lettuce, onion, and tomato) routinely used in phytotoxicity testing. Nanotubes were functionalized with poly-3-aminoben-zenesulfonic acid. Root growth was measured at 0, 24, and 48 h following exposure. Scanning-electron microscopy was used to evaluate potential uptake of carbon nanotubes and to observe the interaction of nanotubes with the root surface. In general, nonfunctionalized carbon nanotubes affected root length more than functionalized nanotubes. Nonfunctionalized nanotubes inhibited root elongation in tomato and enhanced root elongation in onion and cucumber. Functionalized nanotubes inhibited root elongation in lettuce. Cabbage and carrots were not affected by either form of nanotubes. Effects observed following exposure to carbon nanotubes tended to be more pronounced at 24 h than at 48 h. Microscopy images showed the presence of nanotube sheets on the root surfaces, but no visible uptake of nanotubes was observed.
Scale Inhibitor Solutions for High Temperature ESP Lifted Wells in California: A Case History Of Failure Followed By Success
Authors: Wylde J. J. , Fell D. A.
Published: May 2008

Calcium carbonate had been reported in many wells at this Californian asset. All these wells used electronic submersible pumps (ESP) to assist the lift of produced fluids from the reservoir. Scale deposition was causing malfunction of the ESP pumps due to deposition on the pump internals, especially the rotor tips, causing excessive friction and ultimate failure. The temperature around the motor has been measured as 10 – 24°C higher than the bulk produced water temperature of 107 – 121°C. Previously this has not been considered during the selection of scale inhibitors. The cause of scale failures on the ESP wells has been instead attributed to the adsorption of scale inhibitor onto the sometimes significant formation fines produced from the wells.

Several scale inhibitor chemicals had been used in an attempt to inhibit deposition. Whilst general scaling in the bulk fluids seems to be under control, as indicated by the lack of scale deposits elsewhere in the well, deposition still occurred on the ESP pumps themselves. This was likely to be due to a combination of a large pressure drop in the fluids resulting in localized degassing of the produced water (below the bubble point of CO2) and also localized high temperatures on the tips of the pump rotors. Incumbent chemistries used included several different type of phosphonate chemistry.

This paper details the best-in-class chemical reselection process study to determine that the root cause failure hypothesis was correct. This included compatibility testing and scale loop testing using real produced water. The paper then goes onto detail some of the incumbent chemical treatments as well as the step change in performance realized when deployment of a newly evaluated polymeric scale inhibitor.
Development of a New Polymer Inhibitor Chemistry for Downhole Squeeze Applications
Authors: Montgomerie Harry , Chen Ping , Hagen Thomas , Vikane Olav , Matheson Rozenn , Leirvik Vibeke , Frøytlog Cato , Sæten Jens Olav
Published: May 2008

Inhibitor squeeze treatments have been regularly carried out to prevent both sulphate and carbonate scale depositions in a North Sea field since 1990s. Some of the wells, in which the fluid is producing from the "clean" sandstone formation, had experienced a relatively short squeeze life when a conventional phosphonate scale inhibitor was squeezed. Through a research program, a polymer inhibitor was developed and a number of laboratory static and dynamic tests were conducted to evaluate the performances of the newly synthesized polymer inhibitor. Several field trials were also carried out with a satisfactory result.

This paper outlines the idea of how the new inhibitor chemistry was developed and how a special monomer was introduced to make the co-polymer inhibitor. The monomer was introduced to enhance the inhibitor adsorption property since it carries a special function group to have a good affinity to the reservoir rock. This special function group plays a key role for the newly developed scale inhibitor to offer a good squeeze life. The amount of the monomer had to be optimized in order to achieve a good balance to make the inhibitor to be desorbed/released from the reservoir rock. In addition, the environmental property of the polymer was also improved due to the introduction of the special monomer. A number of beaker and dynamic loop tests were carried out and the inhibitor showed an excellent efficiency in both sulphate and carbonate scale inhibition under the test conditions.

The paper also presents the detailed laboratory and field data. In addition, the treatment design strategy and deployment method of the scale inhibitor are discussed.
Experimental Study and Field Implementation of Scale Inhibitor Squeeze Treatments in ShengLi Oilfield of China
Authors: Zuo Jingluan , Ren Shaoran , Fan Zexia , Yan Fangping , Xu Liang , Hu Kaiming , Wang Xiqiang , Chen Hanwei
Published: May 2008

F41 Block is located in the southwest of ShengLi Oilfield, DongYing, East China. The field has been operated for over 20 years. Water flood started in late 1990s using water from nearby aquifers and produced water. The reservoir is characterized with multi-thin oil layers of low permeability and high clay content, and saturated with medium light oil at temperatures of 110-120 °C. Carbonate scales were discovered since 2002, which formed in perforation holes, casing surface, tubing and surface facilities, having a great impact on well production. Frequent downhole scale clean-ups using acids and solvents have been carried in the past in an interval of around 3-6 months.

To control the scale problem and improve oil well production, scale inhibitor squeeze treatment has been tested to replace acidizing since 2006. A combined acidizing and inhibitor squeeze treatment has also been tried in the field for oil wells treated by the squeeze technique in the first time, in order to improve the treatment efficiency and reduce workover time. Experimental study has been conducted for selection of scale inhibitors in terms of chemical compatibility, efficiency of scale control, and adsorption characteristics of the scale inhibitors designed for squeeze treatment. The squeeze treatments have been performed in 6 oil wells, and good performances on inhibiting scale, increasing oil production, and improving pump efficiency have been observed. The squeeze life is expected to be more than two years. This paper reports the results of the experimental study and field operations. This was the first time of applying inhibitor squeeze technique to replace the traditional acidizing to deal with carbonate scales in ShengLi Oilfield. Its success and wide application will have a big implication on safe field operation and local environment protection (by reducing waste acid disposal) in the region.
Thermodynamic Modelling of Naphthenate Formation and Related pH Change Experiments
Authors: Mohammed Murtala A. , Sorbie K. S. , Shepherd A. G.
Published: May 2008

The prediction and prevention of both sodium and calcium naphthenate "scales" is an important issue in oil production. A broad description of how these scales form has been available for some time although most experimental findings are still of a qualitative nature. In this paper, we present an equilibrium thermodynamic model for predicting naphthenate partitioning and precipitation in an oil/brine immiscible system from some chosen initial conditions (i.e. naphthenate initial concentration in oil, brine pH and [Ca2+] etc). This model has, with some assumptions, been applied to both model and real naphthenate system.

This model describes two types of naphthenate experiment, viz. (i) full naphthenate precipitation, and (ii) simpler "pH change" experiments where no precipitation occurs. In order to predict naphthenate precipitation, the theory suggest that we need to know (a) the partition coefficient of the naphthenic acid, HA, between the oil and the water phases, Kow; (b) the pKa of the naphthenic acid in water; and (c) the solubility product, KCaA2 (or other similar solubility parameter), of the naphthenate deposit. In the simpler pH change experiments, we only require the first two of these parameters, i.e. Kow and pKa. Using the naphthenate model without precipitation, we studied the effect of varying parameters on the degree of pH change predicted at equilibrium in the oil/naphthenic acid/brine system. We also applied the model to examine the sensitivities of the various parameters on the final pH. The comparison between the model predictions and experiment at a higher brine pH value is overall satisfactory.
Oil Field Data/Return Analysis: A Comparison of Scale Inhibitor Return Concentrations Obtained With a Novel Analytical Method and Current Commercial Techniques
Authors: Thompson Alan , Gangstad Audun , Kotlar Hans Kristian
Published: May 2008

A new method for detection of polymer-based scale inhibitors is presented. This method is based on traditional chromatographic technique (HPLC) combined with a novel detection system.

Real samples were obtained from several commercial squeeze programs performed on various North Sea fields. The scale inhibitor concentrations were obtained using the novel analytical method and compared to current commercial techniques. The obtained data demonstrate that the novel HPLC method can generate reliable data where the current commercial techniques fail.

This new method will have implications on the overall interpretation of the scale inhibitor return profiles, including: i)what will be the correct parameters to use for the determination of squeeze lifetime?ii)what will be the actual protected water volume above calculated MIC?iii)at what concentration should a re-squeeze be performed?iv)what are the overall economic implications of the treatment?

The HPLC technique is, however, still under development. Further work planned for the technique includes obtaining better resolution for similarly sized polymers thus opening the door to the individual analysis of scale inhibiting polymers from co-mingled well fluids and an improvement in the sample preparation techniques.
Inhibitor Selection for Iron Scale Control in MEG Regeneration Process
Authors: Guan Hua , Cole George , Clark Paul
Published: May 2008

The formation of iron-containing scale due to high dissolved iron content and increased pH (≥8.5) has been observed in a monoethylene glycol (MEG) regeneration system. The control of iron scale deposition under these harsh conditions causes recurring problems in the re-boilers, requires frequent filter change-outs and remains a challenge to the field. To investigate this problem, a modified corrosion testing apparatus was employed to replicate the iron scale formation and to evaluate the performance of selected chemicals under realistic field conditions (specifically: low pH caused by carbon dioxide dissolution; higher pH due to carbon dioxide boiling off from the re-boiler and alkali addition for corrosion control). Both pH and iron levels (including dissolved iron, ferrous iron Fe2+ and total iron) were closely monitored; additionally digital photos were taken at various stages.

There are several challenges associated with the inhibition of iron scale in systems with high iron level (≥150 ppm), high MEG content (≥60%) and high pH (≥8.5). These factors contribute to incompatibility and poor inhibition by conventional inhibitor species. A number of scale-inhibitor products, scale dissolvers and their blends were tested under aerobic or anaerobic conditions. One product was identified to have greatly reduced the rate of scale formation and at higher dosage, indefinitely delayed scale formation. This product also showed the capability to re-dissolve deposits already present in the system.

Evaluation of iron scale inhibitor is a challenge due to the debatable iron-poisoning effect and the lack of standard laboratory methodology. In this paper, the propensity of various iron deposits (e.g., iron carbonate, and insoluble iron/inhibitor complex) is discussed. Moreover, the formation of soluble iron/inhibitor complex is quantified; this could have important implications for the remediation of iron-containing scale.
Enhanced Inhibitor Treatments With the Addition of Transition Metal Ions
Authors: Kan Amy T. , Fu Gongmin , Shen Dong , Al-Saiari Hamad , Tomson Mason B.
Published: May 2008

This paper discusses the research on scale inhibition and squeeze performance in the presence of a transition metal ion, such as Zn2+. Some scale inhibitors have poor retention characteristics in conventional squeeze treatment, where less than 50% of the inhibitors are retained in the formation. In this study, it was demonstrated that over 90% of the same scale inhibitor was retained when Zn2+ was included in the squeeze formulation. Furthermore, Zn2+ showed significant synergistic effect on barite scale inhibition of certain scale inhibitors. Together with phosphonate, Zn2+ also demonstrated a synergistic effect on corrosion inhibition. Laboratory squeeze and flowback simulation and inhibitor efficiency testing under realistic oilfield condition will be discussed. The solution complexation and precipitation chemistry of common phosphonate and polymeric inhibitors with Zn2+ have also been studied. Stronger solution complexes are observed for common scale inhibitors with Zn2+ than that with alkaline earth metal ions, such as Ca2+, Mg2+, and Ba2+. This stronger solution complex formation with transition metal ions may attribute to the observed enhanced inhibition efficiency. Due to the lower solubility of the transition metal ion-scale inhibitor salts, the transition metal ions added to the inhibitor pill significantly improve the retention of some scale inhibitors during squeeze treatment. In this paper, the projected squeeze life (PSL) is defined. When Zn2+ is used in the inhibitor pill, the projected squeeze life for BHPMP is increased by a factor of 60 without significantly impact the environment and cost. Simulation indicates that the squeeze life may be improved from 110 days to 18 years at the Guerra well if this new squeeze procedure is used.
Control Placement of Scale Inhibitors in the Formation With Stable Ca-DTPMP Nanoparticle Suspension and its Transport Porous Media
Authors: Shen Dong , Zhang Ping , Kan Amy T. , Fu Gongmin , Farrell Jesse , Tomson Mason B
Published: May 2008

Diethylenetriaminepentatakis(methylene phosphonic acid) (DTPMP) is commonly used in oilfield for scale inhibition. In this study, Ca-DTPMP submicron-sized particles were prepared directly by chemical precipitation with the assistance of phosphino-polycarboxylic acid (PPCA). The influences of adsorbed PPCA, KCl concentration and sonication on the transport and deposition kinetics of Ca-DTPMP particle suspensions in calcite and sandstone matrix were investigated. Adsorption of PPCA to Ca-DTPMP particles increases their negative surface charge and decreases particles deposition in a porous media. The mobility of PPCA-coated Ca-DTPMP particles decreases with increasing KCl concentrations. Using sonication treatments the mobility of Ca-DTPMP particles at high KCl concentration in porous media increased significantly. The retention and long term flow back performance of Ca-DTPMP particles were tested in Frio sandstone columns after 18 hours shut-in time to allow deposition. The results show that enhanced retention of Ca-DTPMP particles and slow dissolution of DTPMP are highly advantageous in slowing the phosphonate release from porous media, and ensuring successful inhibitor treatments in oil fields.
Iron (II)-Calcium Carbonate: Precipitation Interaction
Authors: Al-Saiari H. A. , Yean S. , Tomson M. B. , Kan A. T.
Published: May 2008

Little attention has been paid to the reaction of mixed calcium-iron carbonate in solutions in comparison with the reaction of other solids such as calcium carbonate, calcium sulfate and barium sulfate. As a result, little information is presently available about the interaction and precipitation of iron carbonate; and mixed calcium/iron. It is known that iron carbonate precipitation kinetics is sensitive to temperature. At high temperature (65 °C), a sharp drop in iron concentration was observed during the first minutes in a solution devoid of calcium. And the drop was gradual at 55 °C. However, adding calcium to the solution under the same conditions had a great influence in reducing the drop in iron concentration. The apperant increases in the solubility of ferrous iron was proportional to the concentration of calcium present in the solution. In addition, presence of calcium in solution also reduced the effect of temperature on siderite precipitation. On the other hand, the presence of iron did not show significant impact in the solubility of calcium. The cumulative molar ratio of ferrous iron to calcium in the precipitated solid was found to be varied based on the amount of siderite that initially precipitated. The X-ray diffraction analysis showed that the presence of ferrous iron inhibited the growth of calcite but did not prevent the formation of aragonite. The crystal shape of siderite, showed by scanning electron microscope, was completely different from that of calcite and the crystal shape of the solid collected in the co-existence of ferrous iron and calcium varied based on the molar ratio of iron to calcium in the solution.
Scale Squeeze Evaluation Through Improved Sample Preservation, Inhibitor Detection and Minimum Inhibitor Concentration Monitoring
Authors: Ramstad Kari , Rohde Hans Christian , Tydal Trine , Christensen Dorthe
Published: May 2008

In North Sea oil and gas fields, seawater injection is used for reservoir pressure support. Formation water and seawater mixing may lead to sulphate scaling in the near wellbore area, tubing and process systems. Scale inhibitor squeeze treatments are applied to protect the producers and extend the field lifetime. Reducing cost and prolonging the squeeze lifetime is essential. In some StatoilHydro operated fields, squeeze lifetime has been evaluated based on inhibitor return concentration and cumulative water treated. Field experience and laboratory studies have determined the criteria for re-squeezing the wells.

One critical aspect of downhole scale management is the laboratory determined Minimum Inhibitor Concentration (MIC) of the squeeze inhibitor. If the MIC is lower than the concentration of inhibitor required to prevent scale at real conditions the well could scale up. Field examples are given where sulphate scale was observed downhole and in the tubing around the safety valve even if the inhibitor concentration was above the laboratory determined MIC. MIC varies throughout the well lifetime according to variation in brine chemistry/operating conditions and should be re-evaluated frequently.

Polymer squeeze inhibitors are difficult to measure with sufficient accuracy at low concentration. However, adequate preservation of the water samples may improve the detection. The volume of water produced before reaching MIC can be significantly increased with improved inhibitor detection methods.

Laboratory studies have been performed addressing the sensitivity of inhibitor detection as function of ion composition, inhibitor concentration, particles and preservation additive. Parallel samples have been taken offshore. MIC has been determined for a range of formation/seawater mixtures.

The paper describes laboratory analyses, sampling procedures, well monitoring, inhibitor return detection and field/well lifetime MIC determination as methods to determine a long but safe squeeze lifetime.
Radial Core Flood Placement Tests
Authors: Stalker R. , Littlehales I. J. , Graham G. M. , Oluyemi G. F.
Published: May 2008

The effective placement of chemical squeeze treatments in heterogeneous wells and long reach horizontal wells has proved a significant challenge, with various factors including heterogeneity, crossflow and pressure gradients between otherwise non-communicating zones within the well, all contributing to an uneven placement of the scale squeeze treatment into the reservoir. Current methods to circumvent these problems often rely on extremely expensive coiled tubing operations, staged diversion (temporary shut off) treatments or by designing treatments to deliberately overdose some zones in order to gain placement in other (e.g. low permeability) zones. As part of a multi-sponsor Joint Industrial Project at Scaled Solutions Ltd., a series of papers has been released in recent years describing the development of a near wellbore placement model, Place iTTM v. 3.0 designed to model properly the flow behaviour of both Newtonian and non-Newtonian injection fluids in the near wellbore region. In this paper, we describe the extension of previously reported laboratory dual linear core flood placement tests technology to the radial case, in which the flow behaviour of the injected fluids more closely resembles that in the near wellbore region. By extending the laboratory test technology in this way, we are able to examine directly aspects of fluid propagation in a manner which directly correlates to field behaviour. We will present laboratory test results comparing the placement of fluids with different properties and show how the results from these tests concur with previous findings and calculations from dual linear placement core flood tests, and we will further expand on the importance of non-conventional fluids for achieving improved chemical placement in complex wells.
Evaluation of the Performance of Different Scale Inhibitors to Sulfate Removal Unit
Authors: Santos T. N. , Gorceix Fundação , Bezerra M. C. M. , Rosa K. R. S. A. , Rocha A. A.
Published: May 2008

The Sulfate Removal Unit (SRU), a nanofiltration system, reduces seawater's Sulfate ions from approximately 2,800 mg/L for 100 mg/L or less. This technology minimizes the formation of Sulfate scales in the oil production. This process uses pressure as a driving force and it uses membranes with nanometric pores that are composed of polymeric material. Decrease in permeability is frequently observed in this nanofiltration process due to the deposition in the surface of the membrane (biofouling and inorganic deposits). The objective of this study is the evaluation of scale inhibitors for Calcium Sulfate that can be formed in the membrane as a consequence of the concentration of the seawater in the SRU. The feed, permeate and concentrate fluids of the SRU were characterized. The chemical composition of the seawater in the polarization region (fluid located in the membrane surface) was estimated considering mass transference between permeate and feed fluids of the SRU, and Fick Law. The chemical composition of the seawater in the polarization region presents higher concentration of Calcium, Magnesium and Sulfate than the one in the concentrate fluid (reject). So the polarized seawater is highly saturated regarding Calcium Sulfate. Thermodynamic model MultiScale was applied to assess the scaling tendency (saturation ratio and precipitate mass) in specific points of the SRU under temperature and pressure conditions. The performance of different chemical classes of scale inhibitors was evaluated. Chemical compatibility of these chemicals with seawater in the polarization region, as well as their inhibition efficiency to Calcium Sulfate precipitation in the conditions of the surface of the membrane were evaluated.
Scale Management in Espadarte Field
Authors: Hernandes R. , Melo V. L. A. , Santos J. A. M. , Rosário F .F. , Bezerra M. C. M. , Rosa K. R .S. A.
Published: May 2008

Espadarte is an oilfield located offshore in the Campos Basin, Brazil, in water ranging from 750 to 1,500 m depth. The first development plan took place in the beginning of 2000. This plan consisted of 8 producers and 4 injectors. The first oil was produced in Espadarte FPSO in August 2000. In 2002, the well (#1) had shown the first strong presence of Barium Sulphate deposits inside the tubing. After trying to chemically remove the scale without success, the solution was to change the entire tubing string, followed by a displacement of a scale inhibitor. As a precaution, it was decided to stop the water injection in order to reach better understanding of the problem.

The Petrobras Research Center gave the necessary support and few months later a scale treatment was designed. With this inhibitor treatment formulation, the operational procedure adopted consisted to inject the inhibitor in a remote way, using stimulation vessels, in order to by-pass the high costs associated with the use of a dedicated rig, since all the wells in Espadarte have wet completion.

A detailed plan was prepared in order to cover all the aspects involved in an operation like this, collecting samples of water produced before and after the injection of the inhibitor. Due to the availability of stimulation vessels, the first campaign took place only in 2005 and permitted the return of the water injection in the field.

This paper presents the methodologies adopted to prevent, and in some cases to remove, the BaSO4/SrSO4 scale in Espadarte wells.
A Semi-Analytical Model for the Simulation of Horizontal and Slanted Wells
Authors: Barreto W. S. , Amado L.C. N. , Priimenko V. I.
Published: May 2008

This paper presents a semi-analytical solution for the pressure drawdown of horizontal or deviated wells in an infinite reservoir considering the well as a source of infinite conductivity. The solution is obtained using the concept of Green’s functions applied to solve the diffuse equation in radial coordinates for a point in an infinite domain kept at a constant pressure. The solution is employed to generate dimensionless functions in order to investigate the behavior of horizontal or slanted wells. Others analytical solutions available in the Literature are used for validation and comparison of results. Calculation procedures are illustrated in the Appendix A and Β at the end of the paper.
Treatment Satisfaction and Quality of Life With Insulin Glargine Plus Insulin Lispro Compared With NPH Insulin Plus Unmodified Human Insulin in Individuals With Type 1 Diabetes
Authors: Ashwell Simon G. , Bradley Clare , Stephens James W. , Witthaus Elke , Home Philip D.
Published: May 2008

OBJECTIVE—The purpose of this study was to compare quality of life (QoL) and treatment satisfaction using insulin glargine plus insulin lispro with that using NPH insulin plus unmodified human insulin in adults with type 1 diabetes managed with multiple injection regimens.

RESEARCH DESIGN AND METHODS—As part of a 32-week, five-center, two-way crossover study in 56 individuals with type 1 diabetes randomized to evening insulin glargine plus mealtime insulin lispro or to NPH insulin (once or twice daily) plus mealtime unmodified human insulin, the Diabetes Treatment Satisfaction Questionnaire (DTSQ) and the Audit of Diabetes Dependent Quality of Life questionnaire were completed at baseline and at weeks 16 and 32, with additional interim DTSQ measurements.

RESULTS—For all patients combined, the mean baseline present QoL score was 1.3, reflecting “good” QoL. Present QoL improved with glargine + lispro but did not change with NPH + human insulin (1.6 ± 0.1 [mean ± SEM] vs. 1.3 ± 0.1, difference 0.3 [95% CI 0.1–0.6]; P = 0.014). Baseline mean average weighted impact score (AWI) of diabetes on QoL was −1.8, indicating a negative impact of diabetes on QoL. The AWI score at end point improved significantly with glargine + lispro but changed little with NPH + human insulin (−1.4 ± 0.1 vs. −1.7 ± 0.1, 0.3 [0.0–0.6]; P = 0.033). Treatment satisfaction (DTSQ 36-0 scale score) at end point was markedly greater with glargine plus lispro compared with that for NPH plus human insulin (32.2 ± 3.4 vs. 23.9 ± 7.2, 8.6 [6.5–10.6]; P < 0.001).

CONCLUSIONS—Insulin glargine plus insulin lispro improves treatment satisfaction, reduces the negative impact of diabetes on QoL, and improves QoL in comparison with NPH insulin plus unmodified human insulin in type 1 diabetes.
Diabetic Retinopathy: More Patients, Less Laser
Authors: Vallance James H. , Wilson Peter J. , Leese Graham P. , McAlpine Ritchie , MacEwen Caroline J. , Ellis John D.
Published: May 2008

OBJECTIVE—We aim to correlate the incidence of diabetic retinopathy and maculopathy requiring laser treatment with the control of risk factors in the diabetic population of Tayside, Scotland, for the years 2001–2006.

RESEARCH DESIGN AND METHODS—Retinal laser treatment, retinal screening, and diabetes care databases were linked for calendar years 2001–2006. Primary end points were the numbers of patients undergoing first or any laser treatment for diabetic retinopathy or maculopathy. Mean A1C and blood pressure and retinal screening rates were followed over the study period.

RESULTS—Over 6 years, the number of patients with diabetes in Tayside increased from 9,694 to 15,207 (57% increase). The number of patients receiving laser treatment decreased from 222 to 138 and first laser treatments decreased from 100 (1.03% of diabetic population) to 56 (0.37%). The number of patients with type 2 diabetes treated for maculopathy decreased from 180 in 2001 to 103 in 2006 (43% reduction, P = 0.03). Mean A1C decreased for type 1 and type 2 diabetic populations (P < 0.01) and a reduction in blood pressure was observed in type 2 diabetic patients (P < 0.01). The number of patients attending annual digital photographic retinopathy screening increased from 3,012 to 11,932.

CONCLUSIONS—Laser treatment for diabetic maculopathy in type 2 diabetic patients has decreased in Tayside over a six-year period, despite an increased prevalence of diabetes and increased screening effort. We propose that earlier identification of type 2 diabetes and improved risk factor control has reduced the incidence of maculopathy severe enough to require laser treatment.
HLA Class II Alleles Specify Phenotypes of Ketosis-Prone Diabetes
Authors: Nalini Ramaswami , Gaur Lakshmi K. , Maldonado Mario , Hampe Christiane S. , Rodriguez Lucille , Garza Gilberto , Lernmark Ake , Balasubramanyam Ashok
Published: May 2008

OBJECTIVE—Ketosis-prone diabetes (KPD) comprises four subgroups based on the presence or absence of β-cell autoantibodies (A+ or A−) and β-cell functional reserve (β+ or β−). Genetic factors could contribute to their distinctive phenotypes. Our aim was to specify the role of HLA class II alleles associated with susceptibility or resistance to autoimmune type 1 diabetes in determining KPD phenotypes.

RESEARCH DESIGN AND METHODS—A total of 185 adults presenting with diabetic ketoacidosis were followed longitudinally for a mean of 5.5 years, with measurements of autoantibodies, β-cell functional reserve, insulin sensitivity, and insulin requirement. Frequencies of susceptibility and resistance alleles at HLA DQA1, DQB1, and DRB1 loci were correlated with clinical and phenotypic features of KPD subgroups and compared with those of ethnic-specific population control subjects.

RESULTS—Susceptibility alleles were more frequent (P < 0.0001) in the two A+ than the two A− KPD subgroups; in the latter, the frequency was no greater than in population control subjects (except for DQB1*0302). Susceptibility alleles differentiated the two clinically similar β− subgroups (more frequent in A+β− than A−β− KPD; P < 0.01). Resistance alleles were more frequent in the two β+ than the two β− KPD subgroups (P < 0.01). The frequencies of certain susceptibility (e.g., DQB1*02) and resistance (DQB1*0602) alleles were higher in African-American A−β+ KPD patients than in African-American control subjects. DQB1*0302 was more frequent in all KPD subgroups compared with control subjects.

CONCLUSIONS—HLA class II alleles associated with susceptibility or resistance to autoimmune type 1 diabetes help specify the four subgroups of KPD. Inheritance of these alleles may influence long-term β-cell functional reserve.
Altered Neuroendocrine Sleep Architecture in Patients With Type 1 Diabetes
Authors: Jauch-Chara Kamila , Schmid Sebastian M. , Hallschmid Manfred , Born Jan , Schultes Bernd
Published: May 2008

OBJECTIVE—The modulatory influence of nocturnal sleep on neuroendocrine secretory activity is increasingly recognized as a factor critical to health. Disturbances of sleep may arise from and contribute to the disease process in chronically ill patients with type 1 diabetes.

RESEARCH DESIGN AND METHODS—Using standard polysomnography and repetitive blood sampling, neuroendocrine sleep architecture was assessed under well-controlled nonhypoglycemic conditions in 14 type 1 diabetic patients and 14 healthy control subjects matched for age, sex, and BMI.

RESULTS—As expected, plasma glucose (P = 0.02) and serum insulin (P < 0.001) levels were constantly higher in type 1 diabetic patients than in healthy subjects throughout the night. Beside these characteristic alterations of glucose metabolism, type 1 diabetic patients displayed higher blood levels of growth hormone (P = 0.001) and epinephrine (P = 0.02) during the entire night and higher levels of ACTH (P = 0.01) as well as a tendency toward higher cortisol levels (P = 0.072) during the first night-half, compared with healthy control subjects. Patients spent slightly less time in slow wave sleep (P = 0.09) during the first night-half (where this sleep stage predominates), and overall exhibited an increased proportion of stage 2 sleep (P = 0.01). Correspondingly, assessment of mood and symptoms after sleep revealed that subjective sleep was less restorative in type 1 diabetic patients than in healthy subjects.

CONCLUSIONS—Our data indicate distinct alterations in the neuroendocrine sleep architecture of patients with type 1 diabetes, which add to the generally adverse impact of the disease on the patients’ health.
Markedly Blunted Metabolic Effects of Fructose in Healthy Young Female Subjects Compared With Male Subjects
Authors: Couchepin Caroline , Lê Kim-Anne , Bortolotti Murielle , da Encarnaçao Joana Amarante , Oboni Jean-Baptiste , Tran Christel , Schneiter Philippe , Tappy Luc
Published: May 2008

OBJECTIVE—To compare the metabolic effects of fructose in healthy male and female subjects.

RESEARCH DESIGN AND METHODS—Fasting metabolic profile and hepatic insulin sensitivity were assessed by means of a hyperglycemic clamp in 16 healthy young male and female subjects after a 6-day fructose overfeeding.

RESULTS—Fructose overfeeding increased fasting triglyceride concentrations by 71 vs. 16% in male vs. female subjects, respectively (P < 0.05). Endogenous glucose production was increased by 12%, alanine aminotransferase concentration was increased by 38%, and fasting insulin concentrations were increased by 14% after fructose overfeeding in male subjects (all P < 0.05) but were not significantly altered in female subjects. Fasting plasma free fatty acids and lipid oxidation were inhibited by fructose in male but not in female subjects.

CONCLUSIONS—Short-term fructose overfeeding produces hypertriglyceridemia and hepatic insulin resistance in men, but these effects are markedly blunted in healthy young women.
Proliferation of Colo-357 Pancreatic Carcinoma Cells and Survival of Patients With Pancreatic Carcinoma Are Not Altered by Insulin Glargine
Authors: Erbel Saskia , Reers Christina , Eckstein Volker W. , Kleeff Jörg , Büchler Markus W. , Nawroth Peter P. , Ritzel Robert A.
Published: May 2008

OBJECTIVE—It was reported that the long-acting insulin analogue glargine induces cell proliferation in a human osteosarcoma cell line and therefore might induce or accelerate tumor growth. Induction of cell proliferation would be particularly relevant for insulin treatment of subjects with diabetes and the potential of bearing tumor cells (e.g., a history of a malignant disease).

RESEARCH DESIGN AND METHODS—Proliferation, apoptosis, and the expression levels of insulin receptor, IGF-I receptor, and insulin receptor substrate (IRS) 2 were analyzed in human pancreatic cancer cells (Colo-357) after incubation (72 h) with insulin glargine or regular human insulin at 0–100 nmol/l. A total of 125 subjects, after partial or total pancreatectomy due to pancreatic carcinoma, were analyzed over a median follow-up period of 22 months.

RESULTS—There was no significant difference between glargine and regular human insulin with respect to regulation of proliferation and apoptosis of Colo-357 cells. The expression levels of insulin receptor, IGF-I receptor, and IRS2 as a downstream molecule of both receptor signaling pathways were not altered at any concentration tested. The insulin receptor was downregulated to a similar degree by glargine and regular human insulin at high insulin concentrations (P < 0.0001 for glargine, P = 0.002 for regular human insulin). The median survival time after pancreatic surgery was 15 months. Survival analysis showed that the time-dependent proportion of patients who survived was identical in patients receiving insulin glargine versus insulin treatment without glargine and control subjects without diabetes after surgery (P = 0.4, three-sample comparison).

CONCLUSIONS—Regular human insulin and insulin glargine may be used to treat diabetes in patients with pancreatic cancer.
Glucose Intolerance and Diabetes Are Observed in the Long-Term Follow-Up of Nonpancreatectomized Patients With Persistent Hyperinsulinemic Hypoglycemia of Infancy Due to Mutations in the ABCC8 Gene
Authors: Gussinyer Miquel , Clemente María , Cebrián Rocio , Yeste Diego , Albisu Marian , Carrascosa Antonio
Published: May 2008

OBJECTIVE—To report the long-term follow-up of three nonpancreatectomized patients with persistent hyperinsulinemic hypoglycemia of infancy due to mutations in the ABCC8 gene.

RESEARCH DESIGN AND METHODS—Oral glucose tolerance test (OGTT) and venous 24-h glucose-insulin profile were performed yearly from adolescence.

RESULTS—Patient 1 (now aged 31 years) developed insulin-dependent diabetes at the age of 25 years. In patient 2 (now aged 17 years), impaired fasting glucose and a diabetic OGTT response with normal A1C values have been observed since the age of 10 years. In patient 3 (now aged 24 years), intolerant OGTT response and hyperglycemic episodes with normal A1C have been observed since the age of 16 years. All patients presented relatively low insulin levels during hyperglycemia, normal BMI, and negative autoantibodies (GAD antibody, insulinoma-associated protein 2, and islet cell antibody).

CONCLUSIONS—Development of glucose metabolism impairment ranging from glucose intolerance to insulin-dependent diabetes is observed in the evolution of these patients.