bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of Subsize Specimens for Irradiation Embrittlement Monitoring of VVER-440/213 RPV Steels
Authors: Nikolaev Yu. A. , Nikolaeva A. V.
Published: March 2008

Results of VVER-440/213 reactor pressure vessel (RPV) surveillance specimens studies showed that all surveillance impact bend specimens were irradiation with a lead factor more than 20 compared to irradiation of the pressure vessel inner surface. This is a special problem of radiation embrittlement assessment for VVER-440/213 RPV materials. Prediction of radiation embrittlement of RPV materials using surveillance specimens is efficient on the basis of accelerated irradiation compared to irradiation of the RPV inner surface. However, the lead factor, which is the ratio of neutron flux affecting surveillance specimens to neutron flux affecting the RPV inner surface in the maximum irradiated zone, should be not too high, when acceleration of steel irradiation would not cause qualitative changes in physical processes of irradiation damage. It is generally assumed that irradiation with a lead factor less than 3–6 provides adequate assessment of radiation embrittlement dependence on the damage dose. In the top part of the chains with VVER-440/213 surveillance specimens, fast neutron flux decreases ∼20 times and the top capsules are irradiated with a neutron flux range close to the flux maximum on the inner surface of the reactor pressure vessel; i.e., the lead factor there is around 1. This concerns both reactors with full core and with dummies on the periphery of the core. The gradient of the neutron flux in the top and bottom parts of chains is great enough; hence, the volume of homogeneously irradiated metal is low. However, there is an opportunity to use material from the top capsules of irradiation sets for correct evaluation of the transition temperature using subsize specimens. As surveillance specimens in the top capsules are irradiated at the same conditions as the pressure vessel, their study allows precise determination of radiation embrittlement of RPV materials. The results of studies of irradiation embrittlement of VVER-440/213 RPV steels using subsize specimens are discussed.
Assessing the Loading Rate for a Fracture Toughness Test in the Ductile-to-Brittle Transition Region
Authors: Lucon Enrico , Scibetta Marc
Published: March 2008

For fracture toughness tests in the ductile-to-brittle transition region, ASTM E1921-05 requires specimens to be loaded using a loading rate dK/dt between 0.1 and 2 MPa√m/s during the initial elastic portion. It has been proposed that the standard allow testing at higher loading rates, including precracked Charpy specimens tested on an instrumented pendulum machine (impact toughness tests). The revised standard would require test results (KJc or To) to be reported along with the relevant loading rate, and should therefore provide guidance on how to assess the value of dK/dt in a relatively simple but reliable manner. Various options for measuring the loading rate have been investigated in this paper for several fracture toughness tests performed at different loading rates (quasi-static, dynamic, and impact). For each loading rate, three different toughness levels have been considered: low, medium, and high. Three considerably different materials have been selected: two RPV steels (JRQ, JSPS) and a ferritic/martensitic 9 % chromium steel (EUROFER97). It is found that the preferable option is given by the ratio between KJc and time at the onset of cleavage, whereas the elastic value Kel/tel or the average dK/dt can be used when partial unloadings are performed.
A família vivienciando o transplante cardíaco
Authors: Brito Lise Maria Pinheiro de Mattos , Pessoa Vera Lúcia Mendes de Paula , Santos Zélia Maria de Souza Araújo
Published: March 2008

Estudo de abordagem qualitativa. O objetivo foi analisar a experiência vivida por familiares durante o processo de transplante cardíaco de seus parentes. Foi realizado na Unidade de Transplante e Insuficiência Cardíaca UTIC do Hospital de Messejana, em Fortaleza-Ceará, com sete familiares. Os discursos foram obtidos através de entrevistas gravadas, e organizados em categorias: descrevendo as mudanças ocorridas, promovendo a adaptação para a provisão do cuidado, e redescobrindo e vivenciando a solidariedade. A análise realizada sugere que o transplante cardíaco gera mudanças, crises e momentos de desestruturação, e que não só a pessoa é abalada, mas também a rede familiar que se esforça para se adaptar a nova situação.
O significado de aprender a pesquisar durante a graduação
Authors: Soubhia Zeneide , Garanhani Maria Lúcia , Dessunti Elma Mathias
Published: March 2008

O trabalho apóia-se na seguinte inquietação: Como o aluno de graduação percebe o seu processo de aprendizagem da pesquisa? O objetivo foi compreender o significado de aprender a pesquisar para o aluno. Trata-se de estudo qualitativo utilizando o referencial de Bardin. O instrumento de coleta de dados continha duas questões norteadoras aplicados a 42 alunos do Currículo de Transição e a 49 alunos do Currículo Integrado do curso de Enfermagem da UEL. A análise dos discursos dos sujeitos permitiu a construção de cinco categorias compostas por subcategorias temáticas que desvelam o significado de aprender pesquisar para esses alunos. O olhar sobre os dados permitiu perceber que a aprendizagem da pesquisa é um processo dinâmico, complexo e constante que requer tempo para o seu desenvolvimento.
Redesenho das atividades de enfermagem para redução de erros de medicação em pediatria
Authors: Yamanaka Tatiana Inglez , Pereira Daniela G. , Pedreira Mavilde L. G. , Peterlini Maria Angélica S.
Published: March 2008

Estudo quase-experimental que verificou a influência do redesenho de atividades de enfermagem para a redução de erros de medicação em três unidades de pediatria de um hospital universitário. Os tipos e freqüências de erros de medicação identificados em estudo realizado nas unidades nortearam o redesenho e exerceram função de variáveis dependentes no estudo da intervenção proposta. Foram analisadas 556 prescrições médicas nos prontuários de 77 crianças. Verificaram-se 8550 doses, em 1498 (17,5%) constataram-se erros, proporção inferior (21,1%) a do estudo controle. Globalmente a intervenção gerou pouca mudança na proporção e na tipologia dos erros de medicação, sendo efetiva para reduzir omissão da dose (p<0,0001), medicação suspensa pelo médico e não registrada como suspensa pela enfermagem (p<0,0001) e hora errada (p=0,0002).
A construção cultural da sexualidade brasileira: implicações para a enfermagem
Authors: França Inacia Sátiro Xavier de , Baptista Rosilene Santos
Published: March 2008

Estudo descritivo objetivando enfocar a construção cultural da sexualidade, influências da mídia na sexualidade humana, como o enfermeiro pode participar do processo de educação sexual. O corpus foi composto por textos da área de Humanas e da Saúde. Utilizou-se a Análise de Conteúdo para categorizar os recortes discursivos. A análise apoiou-se em multireferenciais. Concluiu-se que as relações de gênero são fundadas em categorizações que permeiam a ordem social e determinam a dominação simbólica. Os sistemas simbólicos permanecem inalterados, centrados na premissa da dominação masculina. Existem movimentos considerados "desviantes" que buscam fazer valer uma cartografia da sexualidade que subverte a idéia de identidade secularmente instituída pelo patriarcado. O enfermeiro precisa contribuir para melhorar o conhecimento da população acerca da sexualidade humana.
O Processo de Enfermagem sob a ótica das enfermeiras de uma maternidade
Authors: Freitas Maria Célia de , Queiroz Terezinha Almeida , Souza Jacy Aurélio Vieira de
Published: March 2008

O estudo objetivou conhecer o significado do processo de enfermagem para as enfermeiras obstétricas. Realizou-se em uma maternidade de referência de Fortaleza-CE. Participaram 32 enfermeiras escaladas, nos andares de atendimento obstétrico e ginecológico que responderam a um questionário. As temáticas identificadas foram: conceitos sobre o processo de enfermagem; práticas cotidianas com a utilização do processo e obstáculos para sua implementação. Conclui-se que as enfermeiras têm conhecimento sobre o processo, no entanto apontam que na prática cotidiana existem fatores dificultadores como a falta de tempo, o quantitativo de pacientes internados e a rotatividade das puérperas.
Exclusão gastroduodenal e vagotomia troncular: repercussão no peso corporal e gastrinemia- estudo experimental em ratos
Authors: Leme Pedro Luiz Squilacci , Malheiros Carlos Alberto , Rodrigues Francisco Cesar Martins , Zanqui Andréia Bonizzia , Carvalho Darcy Lisbão Moreira de , Rahal Fares
Published: March 2008

OBJETIVO: A obesidade mórbida é uma doença crônica que se acompanha de várias complicações médicas e de uma menor esperança de vida, prejudicando o aspecto físico, emocional, econômico e social. As pesquisas clínicas e experimentais são amplamente justificadas nesta doença, considerando-se que a opção de tratamento operatório é recente. As gastroplastias e as derivações gástricas são algumas das modalidades terapêuticas propostas e produzem uma grande câmara gástrica remanescente, que em algumas técnicas fica totalmente excluída do trânsito alimentar. As possíveis alterações deste segmento, transformado em apêndice do sistema digestório, representam um vasto campo para pesquisa. Tivemos como objetivo avaliar o peso e as alterações da dosagem de gastrina sérica do rato, após denervação vagal troncular subdiafragmática, com exclusão da câmara gástrica e duodeno do trânsito alimentar do animal. MÉTODO: Foi realizada vagotomia troncular e exclusão gastroduodenal em cem ratos, dos quais trinta puderam ser estudados. Eram ratos machos adultos (Rattus Norvegicus Albinus), da linhagem Wistar, com peso médio de 378,67 g. Este estudo foi complementado pela dosagem sérica de gastrina por radioimunoensaio com I125 e duplo anticorpo para gastrina. RESULTADOS: O peso de todos os ratos estudados diminuiu em média de 378,67 g para 285,83 g. Os trinta animais perderam em média 92,83 g (-24,52%). Houve diferenças significativas entre o peso inicial dos animais e o peso final (p< 0,001). A gastrina sérica também diminuiu em vinte e um dos trinta ratos operados, caindo de 59,68 pg/ml para 46,77 pg/ml em média, correspondendo a uma diminuição de 12,91 pg (-19,73%) entre as duas médias (p< 0,001). A análise estatística teve como objetivo avaliar se houve diminuição nas médias das variáveis: peso e gastrina, medidas antes e depois da operação proposta. Para avaliar as diferenças entre as médias, utilizou-se o teste estatístico do T-Student. CONCLUSÕES: Houve uma diminuição significativa do peso e da dosagem de gastrina sérica do animal.
Câncer de coto gátrico em ratos: papel da associação de Helicobacter pylori e refluxo êntero-gástrico
Authors: Mello Eduardo Linhares Riello de , Arcuri Roberto Alfonso , Bravo Neto Guilherme Pinto , Simões José Humberto
Published: March 2008

OBJETIVOS: Avaliar a relação entre o refluxo êntero-gástrico e Helicobacter pylori na gênese de neoplasias epiteliais e seus precursores, no rato submetido a gastrectomia subtotal com reconstrução a Billroth II. MÉTODO: Foram operados 20 ratos machos da raça Wistar, divididos igualmente em dois grupos: um grupo controle submetido à laparotomia exploradora e outro submetido à gastrectomia subtotal a BII. Após nove meses de operados, os animais foram mortos e seus estômagos estudados quanto à quantificação de H. pylori por glândula gástrica e à alterações epiteliais neoplásicas ou pré-neoplásicas. RESULTADOS: Os animais gastrectomizados tiveram percentual maior de colonização por H. pylori, assim como de alterações epiteliais que variaram do aumento do número de mitoses ao carcinoma invasor. CONCLUSÃO: O comprometimento glandular por H. pylori aumenta com o refluxo êntero-gástrico proporcionado pela gastectomia parcial, e está associado ao desenvolvimento de adenocarcinoma de coto gástrico em ratos.
Intervenção psicoterápica de grupo com pais e bebês: relato de um caso
Authors: Jardim Fernanda Caldas , Zavaschi Maria Lucrécia , Costa Flávia , Perrone Solanger , Zeni Cristian Patrick
Published: March 2008

OBJETIVOS: Demonstrar a eficácia de uma intervenção psicoterápica em grupo (grupo operativo de reflexão) onde pais e bebês são atendidos concomitantemente. METODOLOGIA: Através do relato de caso de uma menina com quadro de crises de agressividade, são discutidos aspectos da intervenção psicoterápica. RESULTADOS: Houve resolução dos sintomas, e aspectos saudáveis da interação mãe-bebê foram restabelecidos. DISCUSSÃO: No caso apresentado, o grupo operativo de reflexão foi fundamental para a melhora dos problemas apresentados por uma dupla mãe-bebê, auxiliando a mãe e o bebê a modificar aspectos disfuncionais na sua interação. CONCLUSÕES: Apesar dos bons resultados para essa família, mais estudos são necessários para avaliar o efeito do grupo operativo de reflexão.
Comparação entre diferentes fontes de dados sobre homicídios no município de São Paulo
Authors: Kilsztajn Samuel , Carmo Manuela Santos Nunes do , Sugahara Gustavo Toshiaki Lopes , Lopes Erika de Souza
Published: March 2008

O artigo compara dados de homicídios de residentes no município de São Paulo entre 1996 e 2000, divulgados pelo Pro-aim, Fundação Seade e Ministério da Saúde; e de homicídios por distrito de residência da vítima no município de São Paulo em 2000, divulgados pelo Pro-aim e pela Fundação Seade. Foram considerados homicídios os óbitos por agressão; intervenção legal e eventos de intenção não determinada causados por disparo de arma de fogo e por contato com objeto cortante/penetrante ou contundente. A diferença entre os números da Fundação Seade e do Ministério da Saúde é desprezível, mas a diferença entre os números do Pro-aim e da Fundação Seade para homicídios de residentes ocorridos na capital em 2000 é expressiva para muitos distritos do município de São Paulo. Além disso, o Pro-aim não registra óbitos de residentes na capital ocorridos em outro município. As análises da taxa de homicídio por distrito do município de São Paulo que utilizam dados do Pro-aim podem levar a resultados muito diferentes das que utilizam dados da Fundação Seade.
Psychobiology of childhood maltreatment: effects of allostatic load?
Authors: Grassi-Oliveira Rodrigo , Ashy Majed , Stein Lilian Milnitsky
Published: March 2008

OBJECTIVE: Facing an adverse physical or psychosocial situation, an individual is forced to adapt in order to survive. Allostasis is the term used to refer to adapting processes used to maintain the stability of an organism through active processes. When allostatic response is excessive or inefficient, the organism develops an allostatic load. The cascade of molecular and neurobiological effects associated with childhood abuse and neglect could be an example of allostatic response that could precipitate allostatic load in organism still vulnerable during its development. This article reviews the psychobiological consequences related to childhood abuse and neglect. METHOD: A selective review with a systematic procedure was performed to investigate studies showing explicit association between childhood maltreatment and psychobiological/neurobiological consequences. We searched electronic database MedLine-PubMed to identify English-language articles from 1990 to 2007. RESULTS: From 115 articles we selected 55 studies from MedLine and 30 from their reference lists, in a total of 85 articles (JCR IF range: 1-31.4; median: 5.88). Only 29 studies showed direct and explicit association between them. CONCLUSION: Structural consequences of childhood maltreatment include disruptive development of corpus callosum, left neocortex, hippocampus, and amygdale; functional consequences include increased electrical irritability in limbic areas, frontal lobe dysfunctions and reduced functional activity of the cerebellar vermis; and neurohumoral consequences include the reprogramming activity of hypothalamo-pituitary-adrenal (HPA) axis and subsequently the stress response.
The Observation/Inference Chart: Improving Students' Abilities to Make Inferences While Reading Nontraditional Texts
Authors: Nokes Jeffery D.
Published: March 2008

The Observation/Inference (OI) Chart is a strategy that can help students learn to make observations and inferences when reading nontraditional texts such as artifacts, paintings or movies. Nontraditional texts can be highly engaging and provide authentic thinking experiences for students, but they can also be difficult to comprehend. Teachers can use the OI Chart to help students think deeply about texts and to become more metacognitive. The OI Chart gives teachers a framework for providing visible strategy instruction as they teach about, model, and give opportunities for students to practice observing and using those observations to make inferences. Included are two examples of powerful history lessons that use OI Charts to help students read a painting and a movie.
The Daily Show With Jon Stewart: Part 2
Authors: Trier James
Published: March 2008

The Daily Show With Jon Stewart is one of the best critical literacy programs on television, and in this Media Literacy column the author suggests ways that teachers can use video clips from the show in their classrooms.
Phosphorylation at serines 104 and 106 by Erk1/2 MAPK is important for estrogen receptor-α activity
Authors: Thomas Ross S , Sarwar Naveed , Phoenix Fladia , Coombes R Charles , Ali Simak
Published: March 2008

Phosphorylation of estrogen receptor-α (ERα) at specific residues in transcription activation function 1 (AF-1) can stimulate ERα activity in a ligand-independent manner. This has led to the proposal that AF-1 phosphorylation and the consequent increase in ERα activity could contribute to resistance to endocrine therapies in breast cancer patients. Previous studies have shown that serine 118 (S118) in AF-1 is phosphorylated by extracellular signal-regulated kinases 1 and 2 (Erk1/2) mitogen-activated protein kinase (MAPK) in a ligand-independent manner. Here, we show that serines 104 (S104) and 106 (S106) are also phosphorylated by MAPK in vitro and upon stimulation of MAPK activity in vivo. Phosphorylation of S104 and S106 can be inhibited by the MAP-erk kinase (MEK)1/2 inhibitor U0126 and by expression of kinase-dead Raf1. Further, we show that, although S118 is important for the stimulation of ERα activity by the selective ER modulator 4-hydroxytamoxifen (OHT), S104 and S106 are also required for the agonist activity of OHT. Acidic amino acid substitution of S104 or S106 stimulates ERα activity to a greater extent than the equivalent substitution at S118, suggesting that phosphorylation at S104 and S106 is important for ERα activity. Collectively, these data indicate that the MAPK stimulation of ERα activity involves the phosphorylation not only of S118 but also of S104 and S106, and that MAPK-mediated hyperphosphorylation of ERα at these sites may contribute to resistance to tamoxifen in breast cancer.
Involvement of bone morphogenetic protein-4 in GH regulation by octreotide and bromocriptine in rat pituitary GH3 cells
Authors: Miyoshi Tomoko , Otsuka Fumio , Otani Hiroyuki , Inagaki Kenichi , Goto Junko , Yamashita Misuzu , Ogura Toshio , Iwasaki Yasumasa , Makino Hirofumi
Published: March 2008

Here we investigated roles of the pituitary bone morphogenetic protein (BMP) system in modulating GH production regulated by a somatostatin analog, octreotide (OCT) and a dopamine agonist, bromocriptine (BRC) in rat pituitary somatolactotrope tumor GH3 cells. The GH3 cells were found to express BMP ligands, including BMP-4 and BMP-6; BMP type-1 and type-2 receptors (except the type-1 receptor, activin receptor-like kinase (ALK)-6); and Smad signaling molecules. Forskolin stimulated GH production in accordance with cAMP synthesis. BRC, but not OCT, suppressed forskolin-induced cAMP synthesis by GH3 cells. Individual treatment with OCT and BRC reduced forskolin-induced GH secretion. A low concentration (0.1 μM) of OCT in combination with BRC (1–100 μM) exhibited additive effects on reducing GH and cAMP production induced by forskolin. However, a high concentration (10 μM) of OCT in combination with BRC failed to suppress GH and cAMP production. BMP-4 specifically enhanced GH secretion and cAMP production induced by forskolin in GH3 cells. BRC, but not OCT, inhibited BMP-4-induced activation of Smad1,5,8 phosphorylation and Id-1 transcription and decreased ALK-3 expression. Of note, in the presence of a high concentration of OCT, the BRC effects suppressing BMP-4-Smad1,5,8 signaling were significantly impaired. In the presence of BMP-4, a high concentration of OCT also attenuated the BRC effects suppressing forskolin-induced GH and cAMP production. Collectively, a high concentration of OCT interferes with BRC effects by reducing cAMP production and suppressing BMP-4 signaling in GH3 cells. These findings may explain the mechanism of resistance of GH reduction to a combination therapy with OCT and BRC for GH-producing pituitary adenomas.
Mechanisms of glucocorticoid-induced myopathy
Authors: Schakman O , Gilson H , Thissen J P
Published: March 2008

Glucocorticoid-induced muscle atrophy is characterized by fast-twitch or type II muscle fiber atrophy illustrated by decreased fiber cross-sectional area and reduced myofibrillar protein content. Muscle proteolysis, in particular through the ubiquitin– proteasome system (UPS), is considered to play a major role in the catabolic action of glucocorticoids. The stimulation by glucocorticoids of the UPS is mediated through the increased expression of several atrogenes (‘genes involved in atrophy’), such as atrogin-1 and MuRF-1, two ubiquitin ligases involved in the targeting of protein to be degraded by the proteasome machinery. Glucocorticoids also exert an anti-anabolic action by blunting muscle protein synthesis. These changes in protein turnover may result from changes in the production of two growth factors which control muscle mass, namely IGF-I and myostatin respectively anabolic and catabolic toward the skeletal muscle. The decreased production of IGF-I as well as the increased production of myostatin have been both demonstrated to contribute to the muscle atrophy caused by glucocorticoids. At the molecular level, IGF-I antagonizes the catabolic action of glucocorticoids by inhibiting, through the PI3-kinase/Akt pathway, the activity of the transcription factor FOXO, a major switch for the stimulation of several atrogenes. These recent progress in the understanding of the glucocorticoid-induced muscle atrophy should allow to define new therapies aiming to minimize this myopathy. Promising new therapeutic approaches for treating glucocorticoid-induced muscle atrophy are also presented in this review.
The Effect of Pressure Decline Rate and Pressure Gradient on the Behaviour of Solution Gas Drive in Heavy oil
Authors: Sheikha Hussain , Pooladi-Darvish Mehran
Published: March 2008

Heavy oil recovery under solution-gas drive is affected by several interacting factors. Among such factors are pressure decline rate and pressure gradients. It has been suggested that a high pressure decline rate (dp/dt) generates larger super- saturation and faster nucleation that leads to more dispersed gas bubbles, while a high pressure gradient (∇p) increases the viscous forces acting on the gas phase enhancing bubble break up and gas dispersion. Both effects lead to lower gas mobility affecting oil recovery; however the relative importance of each is not known. Finding this is important for development of mathematical models and to allow extrapolation of experimental results to field conditions, where the relative importance of these factors changes with time and space. Previous experimental studies were affected by a combination of the two effects.

In this paper we distinguish between the effect of pressure decline rate and pressure gradient on gas mobility and oil recovery, by varying these independently. In the experimental work reported in this paper, change in confining pressure is used to create a change in pressure decline rate, and a change in production rate is used to change the pressure gradient. Several depletion experiments at varying pressure decline rate and production rate are reported here.

At a constant pressure decline rate, the recovery factor tripled when the flow rate was increased by one order of magnitude. Similar experiments were conducted when the pressure decline rate was increased by one order of magnitude but flow rate was kept constant. In this case, the recovery factor did not change significantly. The results of this study clearly indicate that the effect of pressure gradient on gas mobility and oil recovery is much more than the effect of pressure decline rate. This paper presents the experimental results and their analysis, and the implications of these findings on modelling of solution-gas drive in heavy oils.
Well Spacing and Recovery Optimization of One of Iranian Oil Fields by Using Streamline and Reservoir Simulation
Authors: Dehdari V. , Aminshahidy B. , Tabatabaei-nejad A.
Published: March 2008

In development phase of a reservoir and drilling the production wells, it is necessary to drill these wells in appropriate points in order to have no interference in their drainage areas, or have minimum value of interference. In this case, we can produce oil/gas in high flow rate; And in the presence of favorite conditions, recovery factor of the reservoir can be increased.

The objective of this work is to develop a methodology for one of Iranian oil fields by combining the utilization of two important tools: traditional simulation (using of different property maps) and streamline simulation. The conventional simulation (based on finite difference) is used to do the main reservoir simulation by compositional modeling. All the economic analysis is made based on conventional simulations output. Computation of different property maps by this simulator are used for investigation of oil volume, permeability, porosity, reservoir thickness and finally oil saturation maps of our reservoir. The streamline simulation is a supporting tool employed to give more reliability and to bring up insights about the optimization process and speedup to the process, mainly in the identification of best locations of news wells and drainage volume. Also streamline simulation is used to study the fluid flow pattern in the field and determining the efficiency of infill wells.

In this work we use threshold for different property maps of our reservoir in order to find best location of infill wells, then streamline simulation help us to confirm and optimize these locations based on streamline tracing and drainage volume calculations. We defined several scenarios in order to maximize oil production of our reservoir. Results show that by using streamline technique we can improve recovery of reservoir respect to conventional methods.
Properties of Polymer Solution and Gel with Different Electrolytes
Authors: Lu X. G. , Wang W. , Li J. Sh.
Published: March 2008

The polymer clews and flow performance under the effect of electrolytes have been studied. Laboratory experiments were used to determine macroscopic pressure and flow resistance. Optical microscope was used to examine dimensions and shapes of polymer clews.

Experimental results showed that polymer clews and flow resistance force were influenced by the type and concentration of electrolytes. The curling of polymer clews had different optimal concentration scope for different types of electrolytes. Molecular clews became smaller when the concentration of electrolytes was higher under certain concentration scope, and became larger when the concentration of electrolytes exceeded the scope. And the effect of Ca2+ to polymer clews was bigger than Mg2+,both were bigger than that of K+ and Na+. With coagulant it was more likely to form intra-molecular cross-linked reaction when the concentration of electrolytes was higher, which provided a higher flow resistance force and helped to attain a high recovery. When the succeeding water salinity was lower, the polymer Clews would swell, and pressure and resistance force would be further enhanced.

Mechanisms of polymer clews curling and stretching under the influence of electrolyte and coagulant have been analyzed by Stern- Grahame Double-Layer Model and catching and re-catching theory in stratum through coordinating microscopic and macroscopical experiment. The polymer clews would curl and stretch because of the compression of the double layer by ion binding of electrolytes. When succeeding water was diluted, the decrease of electrolyte concentration resulted in the swelling of clews of polymer molecules, re-catching process took place, thus flow resistance in porous media increased.

The objectives of this study was to perform in-depth profile modification by changing molecular clews shape and dimensions, as well as to recycle the produced water in the oilfield for improved oil production.
Optimization of Asphaltene Deposition and Adsorption Parameter in Porous Media Search
Authors: Kariznovi M. , Nourozieh H. , Jamialahmadi M. , Shahrabadi A.
Published: March 2008

The deposition of asphaltene is considered to be one of the most difficult problems during oil production. The mechanism of Asphaltene precipitation and deposition is not fully understood until now. Asphaltene deposition in the reservoir is a complex problem and due to high depth of reservoir, it is impossible to do field experiments. Laboratory tests are expensive and time consuming. In order to study effects of asphaltene deposition, it is be necessary to rely on different models which are developed for Asphaltene adsorption and deposition. These models consist of several matching parameters. Iteration method was used to obtain an acceptable match for experimental data. Deposition equations are highly coupled therefore deposition parameters cannot be optimized independently. Due to dependency of parameters, ordinary optimization methods are not applicable for deposition.

In this paper we introduce a new model for asphaltene deposition in porous media and corresponding numerical method was developed using implicit scheme, then a procedure for matching the asphaltene deposition and adsorption parameters was described and a new optimization method was introduced .In this method genetic algorithm was applied and the result of it was used as input for direct search to obtain an acceptable match for experimental data.
Assessment of Dynamic Filtration Formation Damage for Alaskan North Slope Drilling Fluids
Authors: Kerkar Prasad B. , Patil Shirish L. , Chukwu Godwin A. , Dandekar Abhijit Y. , Khataniar Santanu
Published: March 2008

The recent drive towards open hole completions and highly deviated or horizontal wells in the Alaskan North Slope has emphasized the need for evaluating drilling or completion fluids suitability from a perspective of formation damage. A significant decrease in well productivity near the wellbore can occur due to the invasion of fine solids from drilling fluids, forming external and internal filter cake under dynamic conditions. The objective of this study was to evaluate formation damage caused by drilling fluids typically used for drilling gas hydrate zones. Alaska has vast reserves of gas hydrate, which is a source of energy with great potential for future development. Drilling through gas hydrates results in heat transfer into the formation, leading to dissociation of hydrates. Chilled drilling fluids and high circulation rates are commonly used to minimize this effect. An experimental setup for the evaluation of formation damage at in-situ conditions was designed. At the confining pressure of 1500 psi, chilled drilling fluids at 41-50°F are circulated across the Berea sandstone core for 10 hours in a dynamic filtration core holder. KCl/polymer water-based base mud, flocculated mud, flocculated mud with starch based filtration control material (Mackenzie Delta mud) and dispersed mud are tested at 30, 40, 80 sec−1 and 100/200 psi overbalance with absolute permeability measurement both before and after the drilling fluid circulation. The drilling fluid type, its flow rate, and shear rate, effective particle size, additive concentration, and the amount of static and dynamic overbalance were characterized to establish their influence on drilling mud leak-off volume and the post mud circulation permeability. The results showed that permeability impairment was strongly dependent on annular fluid velocity, amount of overbalance, mud salinity, and state of dispersion of the mud. Dynamic filtration showed significantly higher formation damage than static filtration.
EXPERIENCED STRESS, PSYCHOLOGICAL SYMPTOMS, SELF-RATED HEALTH AND ACADEMIC ACHIEVEMENT: A LONGITUDINAL STUDY OF SWEDISH UNIVERSITY STUDENTS
Authors: Vaez Marjan , Laflamme Lucie
Published: March 2008

In this study we investigated whether or not problems experienced during years at university affect academic achievement. Students enrolled full-time at a Swedish university were followed up from their year of entry in 1998/1999 through to 2000/2001 (N = 1,127) by self-administered
questionnaires. Students' sociodemographic characteristics, their experience of stressors, psychological symptoms, and mental and general health ratings were linked to their academic achievement (degree completed). The extent to which various factors or groups of factors affect academic
achievement was measured by a series of multiple logistic regression analyses. Older students, females, and those enrolled on comparatively shorter programs (3 years) tended to have higher odds of being awarded a degree. Experienced stress brought on by not coping academically and due to study
support demands was a substantial barrier to students' academic achievement.
The Relationship Between Economic Characteristics and Alternative Annual Earnings Persistence Measures
Authors: Baginski Stephen P. , Lorek Kenneth S. , Willinger G. Lee , Branson Bruce C.
Published: March 2008

Accounting researchers (and potentially others) generally select rather simple, lower-order, time-series models to develop proxies for earnings persistence. However, measures of persistence produced by such models are not related to characteristics of the firm's economic environment that are expected to influence earnings persistence. Using a sample of 162 calendar year-end New York Stock Exchange firms, we document the cross-sectional relations between a set of relatively constant, firm-specific, economic characteristics that are theoretical determinants of persistence and measures of earnings persistence derived from both lower-order and higher-order Autoregressive, Integrated, Moving-Average (ARIMA) models. When lower-order ARIMA models are used to generate measures of earnings persistence, the cross-sectional regression models measuring the association between persistence and economic determinants of persistence yield very low adjusted R2s. In sharp contrast, when differenced, higher-order ARIMA models are used to measure earnings persistence, adjusted R2s are in the 10–12 percent range. Moreover, independent variables such as capital intensity, barriers-to-entry, and product-type are all significant in the directions suggested by economic theory. Our results are consistent with Lipe and Kormendi (1994) who argue that higher-order ARIMA models do a better job of capturing the valuerelevance of current period earnings than lower-order models.
Financial Reporting and Auditing Under Alternative Damage Apportionment Rules
Authors: Hillegeist Stephen A.
Published: March 2008

This article analyzes the impacts that three alternative damage apportionment rules have on an owner's financial-reporting decision, an auditor's audit-quality choice, and investors' pricing decisions within the context of a perfectly competitive securities market and owner solvency constraints. The strategic interactions between the players' strategies are analyzed within a setting where payoffs are endogenously determined and vary with the damage apportionment rule. These comparisons speak to potential changes resulting from the Private Securities Litigation Reform Act of 1995 which replaced joint-and-several liability with a proportionate liability rule. The main finding is that the audit failure rate can decrease when there is a switch from a joint-and-several to a proportional liability rule despite the fact that audit quality has also declined. This result occurs when there are strategic interactions between the owner's reporting strategy and the auditor's quality decision.
The Explanatory Power of Earnings Levels vs. Earnings Changes in the Context of Executive Compensation
Authors: Baber William R. , Kang Sok-Hyon , Kumar Krishna R.
Published: March 2008

Studies in the capital market context indicate that earnings changes and earnings levels considered jointly provide a more comprehensive representation of unexpected earnings than either earnings changes or earnings levels considered alone. Recent studies of executive compensation demonstrate that executive compensation revisions are greater when earnings innovations are permanent, than when innovations are transitory. Together, these literatures imply that both earnings changes and earnings levels explain revisions to CEO compensation. Specifically, formal analysis implies that weights on earnings changes vary directly with the persistence of earnings innovations and that weights on earnings levels vary directly with persistence for low persistence observations and inversely with persistence for high persistence observations. Evidence for compensation to 712 executives of U.S. corporations is consistent with these expectations. Such results suggest that earnings levels, earnings changes, and earnings persistence need to be considered when investigating relations between accounting earnings and executive compensation.
Investor Sophistication and Patterns in Stock Returns after Earnings Announcements
Authors: Bartov Eli , Radhakrishnan Suresh , Krinsky Itzhak
Published: March 2008

This study tests whether the observed patterns in stock returns after quarterly earnings announcements are related to the proportion of firm shares held by institutional investors, a variable used by prior research to proxy for investor sophistication. Our findings show that the institutional holdings variable is negatively correlated with the observed post-announcement abnormal returns. Our findings also show that traditional proxies for transaction costs (i.e., trading volume, stock price) as well as firm size have little incremental power to explain post-announcement abnormal returns when institutional holdings is an explanatory variable. If institutional ownership is a valid proxy for investor sophistication, these findings suggest that the trading activity of unsophisticated investors underlies the predictability of stock returns after earnings announcements. However, tests evaluating the validity of institutional holdings as a proxy for investor sophistication yield only mixed results. This calls for caution in interpreting our findings.
Strategic Benchmarks in Earnings Announcements: The Selective Disclosure of Prior-Period Earnings Components
Authors: Schrand Catherine M. , Walther Beverly R.
Published: March 2008

This paper provides evidence that managers strategically select the prior-period earnings amount that is used as a benchmark to evaluate current-period earnings in quarterly earnings announcements. Managers are more likely to separately announce a prior-period gain from the sale of property, plant, and equipment (PPE) than a loss. This strategy provides the lowest possible benchmark for evaluating current earnings, thereby allowing the manager to highlight the most favorable change in earnings. This strategic disclosure behavior is more likely to occur when it prevents a negative earnings surprise. The observed strategic disclosure decisions are consistent with a conjecture by managers that the nonrecurring nature of the prior-period gain/loss will be forgotten unless it is separately announced. Consistent with this conjecture, there is some evidence that equity investors, one potential target of strategic reporting, use the benchmark that managers provide in earnings announcements to evaluate current earnings, even when the components of this benchmark have different persistence. However, cross-sectional analyses provide no evidence that managers ex post exploit the equity mispricing that occurs between the earnings announcement date and the release of the financial statements.
The Effects of Audit Quality and Consequence Severity on Juror Evaluations of Auditor Responsibility for Plaintiff Losses
Authors: Kadous Kathryn
Published: March 2008

This study investigates whether providing higher quality audits increases auditors' chances of avoiding legal liability. Negligence rules hold auditors responsible for plaintiff losses only when the quality of the audit provided fails to meet standards of care. The results of my experiment suggest that the ex post observed consequences of audit failure can affect the standards of care to which jurors hold auditors. Specifically, participants serving in the role of jurors assessed higher standards of care for auditors when the consequences of audit failure were more severe. Furthermore, when the consequences of audit failure were more severe, participants' evaluations of the auditor did not depend on the quality of the audit provided—auditors who provided higher quality audits were evaluated just as negatively as those who provided lower quality audits. In contrast, when audit failure led to only moderately negative consequences, auditors who provided higher quality audits received more favorable evaluations. These results suggest that providing higher quality audits will not necessarily protect auditors from legal liability when the consequences of audit failure are severe.
Audit Committee Composition and Auditor Reporting
Authors: Carcello Joseph V. , Neal Terry L.
Published: March 2008

This study examines the relation between the composition of financially distressed firms' audit committees and the likelihood of receiving going-concern reports. For firms experiencing financial distress during 1994, we find that the greater the percentage of affiliated directors on the audit committee, the lower the probability the auditor will issue a going-concern report. These results support regulators' concern about financial-reporting quality and the recent calls for more independent audit committees.
Tax Holidays and Tax Noncompliance: An Empirical Study of Corporate Tax Audits in China's Developing Economy
Authors: Chan K. Hung , Lan Mo Phyllis Lai
Published: March 2008

Many developing economies use tax holidays to attract foreign investment by providing a limited period of tax exemptions and reductions for qualified investors. This paper investigates the effect of tax holidays on foreign investors' tax noncompliance behavior in China's developing economy. We measure noncompliance in terms of tax audit adjustments the Chinese tax authorities require in response to avoidance and evasion. The results indicate that a company's tax-holiday position affects noncompliance. Companies are least compliant before entering a tax holiday, and most compliant while in a tax-exemption period. In addition, domestic market-oriented companies, service-oriented companies, and joint ventures are less compliant than export-oriented companies, manufacturing-oriented companies, and wholly foreign-owned enterprises, respectively.

Our evidence is relevant to policymakers designing tax incentives to attract foreign investors. Our evidence on noncompliance should also help tax authorities and field auditors plan more effective and efficient tax audits. In addition, the results should provide researchers an interesting perspective to study the effect of tax-rate incentives on corporate tax noncompliance.
Engagement Planning, Bid Pricing, and Client Response in the Market for Initial Attest Engagements
Authors: Johnstone Karla M. , Bedard Jean C.
Published: March 2008

This study examines how client risk factors and the provision of additional services affect engagement planning and bid pricing for a set of initial engagement proposals that a single firm submitted to its prospective clients in 1997–1998. We find little effect of risk on planned personnel hours, but show that the firm responds to fraud and error risk factors by applying engagement-planning strategies such as assigning more high-risk specialist personnel, assigning more industry expert personnel, applying more intensive testing, and/or performing additional review. Analyzing proposed fees while controlling for planned personnel hours, we find risk premia for both fraud and error risk factors. Supplemental analysis of accepted vs. rejected bids shows that the risk premia are detectable for bids accepted by clients (i.e., the engagements the firm will actually perform), implying that risk premia are not bid away in the market. We also find that for clients purchasing additional services, the firm plans more hours and uses industry experts more often. Results reveal a relatively small fee premium for additional services clients across all bids, but analysis of accepted vs. rejected bids implies that this premium is bid away in the market.
Intra-Group, Interstate Strategic Income Management for Tax, Financial Reporting, and Regulatory Purposes
Authors: Beatty Anne , Harris David G.
Published: March 2008

In this study we examine whether banks owned by interstate multibank holding companies coordinate their security gains and losses to manage their tax, earnings, and capital management objectives. Specifically, we examine whether the realization of security gains and losses is related to the objectives of the individual bank, the consolidated group, or both. We find subsidiary banks manage their gain realizations not only to reduce their own state taxes, but also strategically to reduce their consolidated groups' tax expense. Specifically, members of consolidated banking groups shift gain recognition to lower-taxed group members and away from higher-taxed group members. In addition, we find evidence suggesting that banks realize security gains and losses to manage both their own and their groups' financial statement earnings.
The Economic Dilution of Employee Stock Options: Diluted EPS for Valuation and Financial Reporting
Authors: Core John E. , Guay Wayne R. , Kothari S. P.
Published: March 2008

In this paper, we derive a measure of diluted EPS that incorporates the economic implications of the dilutive effects of employee stock options. We show that the existing FASB treasury-stock method of accounting for the dilutive effects of outstanding options systematically understates the options' dilutive effect, and thus overstates reported EPS. Using firm-wide data on 731 employee stock option plans, our proposed measure suggests that economic dilution from options is, on average, 100 percent greater than dilution in reported diluted EPS using the FASB treasury-stock method.

We examine the implications of our analysis for stock price valuation, the price-earnings relation, and the return-earnings relation. We demonstrate analytically that when firms have options outstanding, empirical applications of equity valuation models that use reported per-share earnings as an input (e.g., Ohlson 1995) yield upwardly biased estimates of the market value of common stock. We predict that when the difference between our measure of economic dilution from options and the FASB treasury-stock method dilution from options is greater, the observed return-earnings and price-earnings coefficients will be smaller, and we provide some (albeit weak) empirical support for this prediction.