bluuebunny/crossref_metadata_2025 huggingface dataset:
Traçando mapas: a teoria histórico-cultural e as contribuições para a pesquisa com crianças e suas espacialidades
Authors: Lopes Jader Janer Moreira , Mello Marisol Barenco de , Bezerra Amélia Cristina Alves
Published: April 2015

Este texto busca fazer uma reflexão sobre as pesquisas sistematizadas no campo da infância, tendo como enfoque principal as estratégias de pesquisas “com crianças”. O recorte ao qual nos dedicamos são as relações que as crianças estabelecem com o meio, tendo como foco principal as suas espacialidades. A partir das contribuições de pesquisas que se aportam em estratégias de natureza qualitativas e fundamentadas nos aportes da teoria históricas cultural, elege-se o conceito de vivência (perejivanie) como mote em torno do qual nossos trabalhos são desenvolvidos. Para isso, traça-se, inicialmente, a origem da pesquisa com base em paradigmas positivistas e evidenciam-se alguns caminhos que buscaram romper com essa perspectiva: os postulados etnográficos de Malinovky e Boas; o Interacionismo simbólico, cujo precursor é George Herbert Mead; a Etnometodologia de Harold Garfinkel; as contribuições de Marx e os princípios estabelecidos por Vigotski e seus colaboradores.
Contribuições da teoria histórico-cultural para uma educação infantil como lugar das crianças e infâncias
Authors: Aquino Ligia Maria Leão de
Published: April 2015

O artigo traz reflexões sobre contribuições da teoria histórico-cultural para pensar o papel da educação infantil na sociedade contemporânea. Identifica-se como avanço o processo de institucionalização da educação infantil com sua efetiva integração ao sistema de ensino, o que exige reconhecer as especificidades da infância para se evitar uma simples conformação dessa etapa educacional ao modelo e finalidade da educação escolar de ensino fundamental. Recorre-se à perspectiva histórico-cultural como suporte teórico para afirmar a educação infantil com finalidade de promover o desenvolvimento integral da criança, como preconiza a Lei de Diretrizes e Bases da Educação Nacional (LDB). Estudos vigotskianos sobre a importância da brincadeira para o desenvolvimento humano e sobre os processos de desenvolvimento do pensamento e sua relação com a fala fornecem elementos para se afirmar a brincadeira e as interações como eixos norteadores das propostas pedagógicas destinada a crianças de zero a seis anos.
Questioning the Neutrality of Learning Strategies: teachers' and pupils' use of background knowledge
Authors: Haugen Cecilie Rønning
Published: April 2015

This article investigates educational practices aimed at equitable trainability by looking into an American project on learning strategies that is also being used in Norwegian schools. One special feature of the project is its focus on the pupils' background knowledge. The author examines how background knowledge is interpreted and used in specific classroom contexts. The variation in interpretations from both teachers and pupils demonstrates that it may be hard to channel knowledge and pedagogy in school in specific directions using the learning-strategy project in question. Furthermore, the social background of the student may influence whether legitimate background knowledge is activated and used strategically. The author argues that the research on learning strategies can be developed by drawing on perspectives from the sociology of education.
O Papel da Mediação na Construção de Conceitos Históricos
Authors: Siman Lana Mara de Castro , Coelho Araci Rodrigues
Published: April 2015

O artigo apresenta a análise das interações discursivas ocorridas no plano coletivo de uma aula de História, realizada numa turma de 1o ano do Segundo Ciclo, no contexto de uma pesquisa-ação, que visou à construção do conceito de migração pelos alunos. Tomou-se como suposto teórico que a construção e apropriação de conhecimentos históricos pelos alunos não se processam diretamente entre o sujeito e o objeto a ser conhecido. Entre esses existe o papel mediador dos conceitos históricos e da ação mediada do professor e dos meios mediacionais, ou seja, da linguagem, de signos e ferramentas, na sua construção pelos alunos.
Caryospora bigenetica (Apicomplexa: Eimeriidae) in South America: new hosts and distribution records
Authors: Viana Lúcio André , Mecchi Kamilla Costa , Nascimento Leonardo França do , Herrera Heitor Miraglia , Santa-Rita Paula Helena , Miglionico Marcos Tobias de Santana , Esteves Rhaiza Gama , Gimenez Anibal Rafael Melgarejo , Paiva Fernando
Published: April 2015

The coccidian Caryospora bigenetica was first described in the snake Crotalus horridus (Viperidae) from United States of America. This study represents the first record of the occurrence of C. bigenetica in snakes in South America. Feces were sampled between November 2013 and May 2014 from 256 wild snakes maintained in scientific breeding facilities in the states of Mato Grosso do Sul (MS; n = 214) and Rio de Janeiro (RJ; n = 42), Brazil. Caryospora bigenetica was found in 14 (5.6%) snakes, all belonging to the family Viperidae. Ten Bothrops moojeni and two Crotalus durissus from MS were infected. The coccidian was also found in one C. durissus and in one Bothrops jararacussu from the state of RJ. The oocysts were spherical with a double wall, the exterior lightly mammillated, striations apparent in transverse view, 13.0 µm (12 – 14); polar granule fixed in the internal wall. Sporocysts oval or pyriform, 10.0 × 8.0 µm (9 – 11 × 8 – 9); Stieda body discoid; sub-Stieda body present; sporocyst residuum present, formed by a group of spheroid bodies between sporozoites. This study increases the number of viperid hosts of C. bigenetica and expands the geographical distribution to South America.
Chemical composition and insecticidal activity of Cymbopogon citratus essential oil from Cuba and Brazil against housefly
Authors: Pinto Zeneida Teixeira , Sánchez Félix Fernández , Santos Arith Ramos dos , Amaral Ana Claudia Fernandes , Ferreira José Luiz Pinto , Escalona-Arranz Julio César , Queiroz Margareth Maria de Carvalho
Published: April 2015

Essential oil of Cymbopogon citratus collected from Brazil and Cuba was tested to a chemical characterization and then was tested on the post-embryonic development of Musca domestica. The chemical composition analysis by GC-MS of the oils from Brazil/Cuba allowed the identification of 13 and 12 major constituents respectively; nine of them common to both. In the both oils, the main components were the isomers geranial and neral, which together form the compound citral. This corresponds to a total of 97.92%/Brazil and 97.69%/Cuba of the compounds identified. The monoterpene myrcene, observed only in the sample of Cuba, presented a large relative abundance (6.52%). The essential oil of C. citratus (Brazil/Cuba) was dissolved in DMSO and tested at concentrations of 5, 10, 25, 50, 75 and 100% and citral was prepared by mixing 16.8 mg with 960 µL DMSO. Both essential oils and monoterpene citral were applied topically to newly-hatched larvae (1µL/larva). The results showed a lethal concentration (LC50) of 4.25 and 3.24% for the Brazilian and Cuban essential oils, respectively. Mortalities of larval and newly-hatched larvae to adult periods were dose-dependent for the two both oils as for monoterpene citral, reaching 90%. Both essential oils and citral caused morphological changes in adult specimens.
Parasites in the mangrove oyster Crassostrea rhizophorae cultivated in the estuary of the Graciosa River in Taperoá, Bahia
Authors: Cova Aliane Watanabe , Serafim Júnior Moacyr , Boehs Guisla , Souza Jackson Moreira de
Published: April 2015

In this work, parasites associated with the mangrove oyster Crassostrea rhizophorae were studied at a cultivation unit in the estuary of the Graciosa River in Taperoá, Bahia. On a monthly basis, between April 2011 and March 2012, 20 oysters were collected, measured and fixed in 10% formaldehyde. In order to identify the parasites, routine histological techniques were used. The specimens were embedded in paraffin and sections, 7 µm thick, were cut. These were then stained with Harris hematoxylin and eosin and were examined using an optical microscope. The parameters analyzed to investigate water quality showed that the temperature ranged from 23.9 °C to 29.3 °C, water salinity from 0.4 to 24.2 Practical Salinity Units PSU and recorded rainfall from 80 mm to 406.4 mm/month. During the parasitological analyses, infestation of the polychaete Neanthes succinea was observed in 41% of the oysters. Through histological techniques, the following parasites were identified: colonies of Rickettsia-like organisms (RLOs); the protozoa Nematopsis sp. and Ancistrocoma sp.; the turbellarian Urastoma sp.; the metacestode Tylocephalum sp. and an unidentified tapeworm. The data collected showed that there was low-intensity infection with and prevalence of parasites, except for Nematopsis sp., thus attesting that these cultivated oysters were in a healthy condition.
The importance of accurate weather and climate information in civil engineering
Authors: Faragher John
Published: April 2015

Global weather is ever-changing and evidence suggests that some types of extreme weather are becoming more frequent. Given the big impact it can have on infrastructure construction and operation, civil engineers need more than ever to ensure they have the most accurate short- and long-term forecasts, says John Faragher at the UK Met Office.
CHOICE OF HEAT SOURCE FOR RESIDENTIAL BUILDINGS
Authors: VATUZOV Denis N. , PURING Svetlana M. , FILATOVA Elena B. , TYURIN Nikolay P.
Published: April 2015

The main factors of choice of thermal energy source for residential and public buildings in case of central heat supply unability are viewed. The current regulatory documents of the Russian Federation in the matt er of design of decentralized heat supply sources - independent boiling rooms and individual boilers - are analyzed. The comparative analysis of proposed fi ndings is made.
ANALYSIS OF THE PROCESS OF BIOLOGICAL WASTEWATER TREATMENT WITH NUTRIENT REMOVAL
Authors: BORISOVA Vita Yu.
Published: April 2015

The analysis of the structures of biological wastewater treatment plants with nutrient removal, basic design parameters of the processes of nitrification and denitrification are presented.
Mechanisms underlying local functional and phylogenetic beta diversity in two temperate forests
Authors: Wang Xugao , Wiegand Thorsten , Swenson Nathan G. , Wolf Amy T. , Howe Robert W. , Hao Zhanqing , Lin Fei , Ye Ji , Yuan Zuoqiang
Published: April 2015

Although trait information has been widely used to explore underlying mechanisms of forest community structure, most studies have focused on local patterns of phylogenetic or functional alpha diversity. Investigations of functional beta diversity, on the other hand, have not been conducted at local scales in a spatially explicit way. In this study, we provide a powerful methodology based on recent advances in spatial point pattern analysis using fully mapped data of large and small trees in two large temperate forest plots. This approach allowed us to assess the relative importance of different ecological processes and mechanisms for explaining patterns of local phylogenetic and functional beta diversity. For both forests and size classes, we found a clear hierarchy of scales: habitat filtering accounted for patterns of phylogenetic and functional beta diversity at larger distances (150–250 m), dispersal limitation accounted for the observed decline in beta diversity at distances below 150 m, and species interactions explained small departures from functional and phylogenetic beta diversity at the immediate plant‐neighborhood scale (below 20 m). Thus, both habitat filtering and dispersal limitation influenced the observed patterns in phylogenetic and functional beta diversity at local scales. This result contrasts with a previous study from the same forests, where dispersal limitation alone approximated the observed species beta diversity for distances up to 250 m. In addition, species interactions were relatively unimportant for predicting phylogenetic and functional beta diversity. Our analysis suggests that phylogenetic and functional beta diversity can provide insights into the mechanisms of local community assembly that are missed by studies focusing exclusively on species beta diversity.
Upregulated Leptin in Periodontitis Promotes Inflammatory Cytokine Expression in Periodontal Ligament Cells
Authors: Li Wei , Huang Baoxin , Liu Kaining , Hou Jianxia , Meng Huanxin
Published: April 2015

Background: Imbalance or disruption in the expression of inflammatory mediators contributes greatly to the breakdown of the periodontal supporting tissues. Leptin, through binding to its receptor (obesity‐related leptin and leptin receptor [OBR]), has potent effects on immunity and inflammation. However, to date, researchers only indicated a role of leptin in periodontitis. No direct or valid evidence exists about how leptin and its receptor are regulated by local inflammation, what effects they have, and the underlying mechanisms.

Methods: Experimental periodontitis was induced by ligation of mandibular second molars in beagle dogs. The expression of leptin, OBR, and interleukin (IL)‐1β was examined by immunohistochemistry. Meanwhile, recombinant human IL‐1β was used to stimulate human periodontal ligament cells (hPDLCs) in vitro, and mRNA and protein levels of leptin were measured using real‐time polymerase chain reaction (PCR) and enzyme‐linked immunosorbent assay (ELISA), respectively. Then, mRNA and protein levels of IL‐6 and IL‐8 were measured using real‐time PCR and ELISA, after stimulation with various concentrations of leptin, knocking down all or only the long form of OBR (OBRb) by small interfering RNA and incubation with multiple intracellular signaling pathway inhibitors, respectively.

Results: Leptin and OBR increased substantially in inflammatory periodontal tissues, which correlated well with the extent of inflammatory infiltration, and was a result of the upregulation in resident cells themselves. A high dose of leptin could induce the expression of mRNA and protein of IL‐6 and IL‐8 in hPDLCs through binding with OBRb and activating different intracellular signaling pathways.

Conclusion: Upregulated leptin and OBR in periodontitis stimulated proinflammatory cytokine expression in PDL cells to additionally promote local inflammation.
Improving Identification of Fall-Related Injuries in Ambulatory Care Using Statistical Text Mining
Authors: Luther Stephen L. , McCart James A. , Berndt Donald J. , Hahm Bridget , Finch Dezon , Jarman Jay , Foulis Philip R. , Lapcevic William A. , Campbell Robert R. , Shorr Ronald I. , Valencia Keryl Motta , Powell-Cope Gail
Published: April 2015

Objectives. We determined whether statistical text mining (STM) can identify fall-related injuries in electronic health record (EHR) documents and the impact on STM models of training on documents from a single or multiple facilities.

Methods. We obtained fiscal year 2007 records for Veterans Health Administration (VHA) ambulatory care clinics in the southeastern United States and Puerto Rico, resulting in a total of 26 010 documents for 1652 veterans treated for fall-related injury and 1341 matched controls. We used the results of an STM model to predict fall-related injuries at the visit and patient levels and compared them with a reference standard based on chart review.

Results. STM models based on training data from a single facility resulted in accuracy of 87.5% and 87.1%, F-measure of 87.0% and 90.9%, sensitivity of 92.1% and 94.1%, and specificity of 83.6% and 77.8% at the visit and patient levels, respectively. Results from training data from multiple facilities were almost identical.

Conclusions. STM has the potential to improve identification of fall-related injuries in the VHA, providing a model for wider application in the evolving national EHR system.
Finding the Perfect Doctor: Identifying Lesbian, Gay, Bisexual, and Transgender–Competent Physicians
Authors: Khalili Joshua , Leung Lucinda B. , Diamant Allison L.
Published: April 2015

Objectives. We assessed the existence of procedures and policies for identifying lesbian, gay, bisexual, and transgender (LGBT)–competent physicians at US academic faculty practices, and sought to identify physician training programs that enhance LGBT competency.

Methods. We invited all 138 Liaison Committee on Medical Education–accredited US academic faculty practices to participate in a survey in 2012. We systematically assessed their procedures and policies to identify LGBT-competent physicians and their LGBT-competency training. We also assessed geographic region, funding source, and an LGBT health center in the same state. We performed univariate, bivariate, and multivariate logistic regression analyses.

Results. The response rate was 50%. Few participants had existing procedures (9%) or policies (4%) to identify LGBT-competent physicians. Procedures included online directories with self-identified LGBT-competent physicians available to the public. Sixteen percent of participants reported having comprehensive LGBT-competency training, and 52% reported having no training. Of note, 80% of participants indicated interest to do more to address these issues.

Conclusions. There exist both need and interest for US academic faculty practices to develop procedures, policies, and programs that improve access to LGBT-competent physicians and to train physicians to become LGBT-competent.
Association of Participation in the Supplemental Nutrition Assistance Program and Psychological Distress
Authors: Oddo Vanessa M. , Mabli James
Published: April 2015

Objectives. We assessed whether households’ participation in the Supplemental Nutrition Assistance Program (SNAP) was associated with improvements in well-being, as indicated by lower rates of psychological distress.

Methods. We used longitudinal data for 3146 households in 30 states, collected between October 2011 and September 2012 for the SNAP Food Security survey, the largest longitudinal national survey of SNAP participants to date. Analyses compared households within days of program entry to the same households approximately 6 months later. We measured psychological distress in the past 30 days on a 6-item Kessler screening scale and used multivariable regression to estimate associations between SNAP participation and psychological distress.

Results. A smaller percentage of household heads exhibited psychological distress after 6 months of participation in SNAP than at baseline (15.3% vs 23.2%; difference = −7.9%). In adjusted models, SNAP participation was associated with a decrease in psychological distress (adjusted relative risk = 0.72; 95% confidence interval = 0.66, 0.78).

Conclusions. Continuing support for federal nutrition programs, such as SNAP, may reduce the public health burden of mental illness, thus improving well-being among vulnerable populations.
E-Cigarette Use in the Past and Quitting Behavior in the Future: A Population-Based Study
Authors: Al-Delaimy Wael K. , Myers Mark G. , Leas Eric C. , Strong David R. , Hofstetter C. Richard
Published: April 2015

Objectives. We examined whether smokers who used e-cigarettes are more likely to quit after 1 year than smokers who had never used e-cigarettes.

Methods. We surveyed California smokers (n = 1000) at 2 time points 1 year apart. We conducted logistic regression analyses to determine whether history of e-cigarette use at baseline predicted quitting behavior at follow-up, adjusting for demographics and smoking behavior at baseline. We limited analyses to smokers who reported consistent e-cigarette behavior at baseline and follow-up.

Results. Compared with smokers who never used e-cigarettes, smokers who ever used e-cigarettes were significantly less likely to decrease cigarette consumption (odds ratio [OR] = 0.51; 95% confidence interval [CI] = 0.30, 0.87), and significantly less likely to quit for 30 days or more at follow-up (OR = 0.41; 95% CI = 0.18, 0.93). Ever-users of e-cigarettes were more likely to report a quit attempt, although this was not statistically significant (OR = 1.15; 95% CI = 0.67, 1.97).

Conclusions. Smokers who have used e-cigarettes may be at increased risk for not being able to quit smoking. These findings, which need to be confirmed by longer-term cohort studies, have important policy and regulation implications regarding the use of e-cigarettes among smokers.
Work Disability Before and After Diabetes Diagnosis: A Nationwide Population-Based Register Study in Sweden
Authors: Ervasti Jenni , Virtanen Marianna , Pentti Jaana , Lallukka Tea , Tinghög Petter , Kjeldgard Linnea , Mittendorfer-Rutz Ellenor , Alexanderson Kristina
Published: April 2015

Objectives. We evaluated the risk of work disability (sick leave and disability pension) before and after diabetes diagnosis relative to individuals without diabetes during the same time period, as well as the trajectory of work disability around the diagnosis.

Methods. This Swedish population-based cohort study with register data included 14 428 individuals with incident diabetes in 2006 and 39 702 individuals without diabetes during 2003 to 2009.

Results. Work disability was substantially higher among people with diabetes (overall mean = 95 days per year over the 7 years, SD = 143) than among those without diabetes (mean = 35 days, SD = 95). The risk of work disability was slightly higher after diabetes diagnosis than before and compared with the risk of those without diabetes. The trajectory of work disability was already increasing before diagnosis, increased even more at the time of diagnosis, and leveled off after diagnosis. Individual sociodemographic characteristics and comorbid conditions contributed both to the risk and to the trajectory of work disability.

Conclusions. Although diabetes has an independent effect on work disability, sex, age, education, and comorbid conditions play a significant role.
New Advances in Mechanical Engineering Enables Pulling Forces of up to 60,000 lbs. – Experience Gained from Offshore Norway Case Stories
Authors: Buch Jørgen , Mourani Houssam , Ngo Dong
Published: April 2015

Objectives/Scope

This paper will present an improvement in engineering in the form of a hydraulic stroking tool with the ability to apply 60,000 lbs. of force. The tool has already been applied offshore Norway and lessons learned from these recent operations will also be disclosed.

Methods, Procedures, Process

In one operation, a plug was accidentally set across the christmas tree and blowout preventer (BOP), effectively eliminating the christmas tree as a well barrier element, and constituting a serious HSE risk. Conventional solutions failed to release the plug due to an insufficient pull force and then a failing jar.

In another well, the setting tool had malfunctioned resulting in a partially set plug and a stuck tool. Repeated attempts with heavy duty fishing equipment had damaged the fishing neck, further complicating the fishing operation as the setting tool had failed before it could break the stud connecting to the plug.

Results, Observations, Conclusions

The high performance of the recently developed stroking tool turned out to be the correct solution for both of these demanding operations. In the first well, it was estimated that the force required to shear the plug from the setting tool would be 43,300 lbs. The operation was completed in three runs with no misruns, which saved the operator from prolonged exposure to HSE risk including well control situation.

In the second well, the force required to shear the stud and free the setting tool was 40,000 lbs. Two release devices were combined in the toolstring, one below the hydraulic stroker and one below the cable head, in order to allow further contingencies to mitigate risk and increase safety. After four attempts the shear stud parted, thus completing the setting sequence and freeing the stuck setting tool. The operator got the well back on track, saved five days of rig time and avoided the costs of a workover rig.

Novel/Additive Information

The case stories in this paper constitute the first jobs performed with the new tool. Two important features are reduced HSE risks and increased operational efficiency, which will also be captured in the paper.
Standardizing Planning and Cooperation Across Departments and Organisations to Increase Efficiency and Decrease Repeated Mistakes
Authors: Andersen Øystein , Djomina Maria , Mathisen Petter
Published: April 2015

As technology has developed over the recent years, engineers have gained access to more and more powerful tools to solve difficult engineering tasks. All of these tools have generated enormous quantity of data that in many cases has been filed but never used again. The technological development has not changed the fundamental ways engineers and organisations work in silos, making it difficult to take advantage of historical data and learned experiences for future improvement.

This paper introduces a new online database that combines data and experience from previous operations in order to increase efficiency of planning and execution of well operations in the future. By developing a platform for recording and managing any data in one readable mode, a method for standardizing data formats and content was created. In order to extract maximum of the available data saved by different users in various organisations, a common usable log was developed to export readable data. The online software tool was developed using public data and can be futher extended by adding commercial and user related business information. With one platform to share and visualize data there will be a significant advantage for the organization making use of all data and learning from project to project.

Throughout developing a platform for reusing and sharing data and experiences it has been found that significant time can be saved planning new projects. Not only can time be saved, but by removing the manual process of searching and processing data, the quality of the data analysis increases dramatically, removing high risk elements to the project. By sharing experiences between departments and organisations and making them easily available in the planning phase, gradually changes the way the engineer have been working. The mindset to focus on best practices has changed by being open to sharing experience. Saving time on manual searches, data processing and capturing important experiences has led to better cooperation, time saving and increase of quality in planning and operation execution. By testing the database internally first, it has been proved that 1-3 weeks of work can be saved on each project normally devoted to data search and processing. This allows the engineer primarily to focus on his main tasks. Focusing on the main task and using the data and experiences for choosing the best solution has led to significant decrease of risk and cost.

As data and experiences normally belong to departments, projects or organisations, it has been found that most companies do not efficiently share these across their organisation, and even less with other companies. With a web based platform for experience and data capture and sharing, companies can for the first time be able to share data across the whole organization. This will ultimately lead to a learning organization that will improve the quality of deliveries in the longer perspective.
CFD Analysis and Model Comparison of Annular Frictional Pressure Losses While Circulating Yield Power Law Fluids
Authors: Erge Oney , Ozbayoglu Evren M. , Miska Stefan Z. , Yu Mengjiao , Takach Nicholas , Saasen Arild , May Roland
Published: April 2015

A computational fluid dynamics (CFD) analysis is conducted on the flow of Newtonian and non-Newtonian fluids in annuli including the effect of inner pipe rotation. A practical numerical model is proposed that accurately estimates the annular frictional pressure losses with and without the inner pipe rotation. Experiments are conducted at a 91 ft. long flow loop using various fluids that can be characterized as Yield Power Law (YPL). A commercial CFD software is used to validate the proposed numerical approach. A comprehensive comparison of the proposed model, CFD results, experimental results, the published experimental results and most widely used models from the literature is presented.

The experimental setup simulates horizontal wellbore applications, which are increasingly prevalent due to recent shale plays. Today, since most drilling fluids show YPL behavior, YPL fluids with a wide range of rheological properties are used as test fluids in this study. The numerical model is coupled with a stability criterion that determines the onset and offset of the transitional flow between laminar and turbulent regions. The velocity profiles of a wide range of diameter ratios, Taylor and Reynolds numbers are presented. Various degrees of eccentricity are analyzed in terms of pressure profile and flow stability with the proposed method.

The results from the experiments show significantly reduced pressure drops in fully eccentric annuli compared to concentric geometry. An increase in pressure loss is observed as the pipe is rotated while it is eccentric. The comparisons between the models indicate that the slot approximation can result in large errors especially when the diameter ratio is low. A 3D wellbore can be evaluated with grids using the proposed numerical method and the local stability criterion, which leads to accurate pressure loss estimations. Grid analysis can show the flow state profile and the pressure loss profile of a wellbore, which has potential to optimize operations in real-time or in the design phase.

This study contributes to a better understanding of flow in annuli. The results obtained from this study are useful to predict the transition and the annular frictional pressure loss profiles more accurately than existing methods. Potential applications include risk avoidance and optimized operations.
Study of Thermal Variations in Wells During CO2 Injection
Authors: Lund Halvor , Torsæter Malin , Munkejord Svend Tollak
Published: April 2015

Carbon dioxide (CO2) can be injected into the subsurface for the purpose of enhanced oil recovery (EOR), possibly with geological CO2 storage. This procedure brings about a set of unique challenges with respect to well construction, operation and remediation. As compared to normal production, CO2 injection imposes lower temperatures and stronger temperature variations on wells. This is especially prevalent if the injection is not continuous. Downhole temperature variations will result in expansion or contraction of casings and well barrier materials, which can cause them to crack or de-bond at interfaces. To avoid leakage paths through wells it is therefore important to understand within which temperature intervals it is safe to operate.

In the present paper we describe a heat-conduction model for calculating heat transfer from the well to the casing, annular seal and rock formation. These materials have dissimilar thermal properties, and will behave differently upon downhole temperature variations. The model is discretized using a finite-volume method developed especially for accurate calculation of heat conducted radially in a well. This allows us to predict temperatures and temperature variations at various locations in and around a given well during CO2 injection.

To verify the numerical model, we compare our simulation results with the time-varying temperatures measured in our laboratory. Good agreement is found between the numerical predictions and the measured data. Simulation results are presented for different combinations of formations and well barrier materials (cement and alternative types of annular sealants) to display their effect on the well temperature. It is found that by replacing cement with an annular sealant material with higher thermal conductivity, the temperature difference between the casing/seal interface and the seal/rock interface can be significantly reduced. A high-conductivity formation such as halite/rock salt can also reduce thermal gradients in the well materials.
Statfjord Implements a New Gas Lift Casing Design with 11 ¾ Liner to Open ~ 40 Slots for 13 3/8 exit
Authors: Lunkad Siddhartha F. , Haaland Sigurd , Svanes Kåre , Østensen Ståle
Published: April 2015

Statfjord Field is one of the largest and oldest fields on NCS and operates with platforms Stafjord A, B and C. In recent years, slot recovery to drill more wells has posed a big challenge to deliver wells with Gas Lift design due to extensive and time & cost consuming P&A and casing cut & pull operations. As Statfjord is operating in late life phase using artificial gas lift as a secondary recovery approach, well designs to meet NORSOK well integrity casing design requirements is a key design focus. Along with the above mentioned technical challenges, improving operational excellence has driven the concept of innovative casing design with 11 ¾″ liners. This design eliminates the time spent on extensive casing retrieval operations. In addition, reduces time and risks associated with drilling 17 ½″ section that requires changing from 13 5/8″ to 21 ¼″ BOP, higher flow rates for hole cleaning and larger volume of cutting injection, and waiting 13 3/8″ casing hangers that are crucial long lead item. Installation of 11 ¾″ liner and cementing 9 5/8″ casing in tight ECD margins were identified as high priority design goals in the early planning phase. To address aforementioned challenges and meet design goal in time and cost efficient way, innovative ideas were a fundamental necessity.

This paper discusses the background behind need for a new gas lift well design for well 33/12-B-42 B, casing design approach, challenges faced during planning and learnings from operations. Key operational highlights leading to successful well delivery were: optimization of 11 ¾″ liner depth to meet gas lift formation strength requirements; successful 11 ¾″ liner cement job with rotation to secure the secondary barrier envelop; and opening the narrow ECD window between 9 5/8″ casing and 11 ¾″ liner with to Low Rheology Oil Based Mud (LROBM) after drilling 10 5/8″ × 12 ¼″ section with Conventional Oil Based Mud (COBM). Successful cement job on 9 5/8″ casing facilitated the improved production profile by placement of production packer in 9 5/8″ casing instead of 7″ liner. The new gas lift well design has opened ~ 40 slots for 13 3/8″ exit on Statfjord and it is expected to reduce the time consuming casing retrieval and slot recovery operations
Cement Sheath Integrity During Thermal Cycling: A Novel Approach for Experimental Tests of Cement Systems
Authors: De Andrade J. , Sangesland S. , Todorovic J. , Vrålstad T.
Published: April 2015

Well cement is placed into the annulus between casing and formation to provide structural support and zonal isolation through the well lifecycle. Nevertheless, operators in the North Sea have been concerned by the ability of the cement sheath to maintain sealing integrity given to the increasing number of reported failures in mature wells. As a result, recent efforts have been undertaken to achieve enhancements in the technology and standardization of tools to assess the status of this barrier. Yet, progress seems slow due to the high complexity of performing the task downhole. Hence, a new laboratory setup is designed to permit a detailed assessment of cement sheath failure mechanisms for realistic wellbore curing and operating conditions.

The laboratory set-up is conceived to allow visualizing the development of possible leak paths throughout the cement sheath, such as de-bonded areas and cracks in the bulk of cement, when exposed to pressure- and temperature-related varying loads. It comprises downscale concentric cylinders of rock, cement and pipe attempting to resemble a cased wellbore section. Temperature and pressure inside the casing can be varied in a controlled manner. In addition, cement pore pressure and rock confining pressure can be controlled independently. Computed tomography (CT) scans of the sample before and along the cyclic loads provide geometric three-dimensional information that aids identifying how and where the cement sheath is damaged.

The first trials of the pressurized cell deal with two samples, one with sandstone and one with shale rock, with centralized pipe and Portland G cement. During the curing process temperature and pressure are kept constant. After the cement sets, pressure is kept constant while casing temperature is varied along several cycles. Initial CT analyses show that cement hydraulic pressure provides a better initial cement job than for previous cemented samples with no pressure. In that sense, it was found better cement bonding to casing and formation, as well as less volume of voids after cement cured. Moreover, the cracking failure mechanisms resulting from thermal cyclic loads were mitigated due to the reduction of tensile stresses, since cement hydrostatic stress and confining pressure around the rock exists.

With this new laboratory set-up it is possible to evaluate the capabilities of any type sealant material to withstand varying temperature and pressure loads by visualization and quantification of de-bonded areas and cracks propagation along the time. The method offers an alternative to study in detail and compare sealant materials used as annular barrier when exposed to realistic wellbore thermal loads.
Best Practices of Integrated Well Placement Technologies in Developing an Ultrathin Reservoir: A Case History from Tarim Basin West China
Authors: Li Qiang , Liu Ruiying , Kang Peng , Xia Guofeng , Zhang Xingwang , Yin Zhiping , Lin Xin , Wang Yong , Sun Qigang , Wu Bohong , Kok Jeffrey
Published: April 2015

To enhance the production of an ultrathin reservoir off a single lateral well, operators implemented a double-step profile well that threads two ultrathin layers with a displacement of 300~400 m in lateral length within each layer. The well is part of an integrated well placement approach that has significantly increased production from the ultrathin (0.4~0.8-m) reservoir of Hadexun oilfield, China. The program includes a hybrid drilling system, near-bit measurements, bed-boundary mapping, and real-time borehole images to manage risks while reducing construction costs in this complex reservoir.

At the time of publication, 15 wells had been successfully executed and plans for constructing pilot wells were eliminated, achieving an 86% net-to-gross and reducing the drilling cycle by almost one-third. Similar solutions can be applied in other ultrathin reservoir blocks to achieve repeated success.
A New Method of Predicting the Well Performance of Multi-Frac Horizontal Wells
Authors: Shen Z. , Ling K. , Yip Y.
Published: April 2015

Multi-fractured (multi-frac) horizontal wells have emerged as an advanced mean for enhancing well productivity in low permeability reservoirs, being used to advance the development of shale oil and shale gas reservoirs. Fluid transport in the fracture domain is dominated by the fracture effect. In the non-fracture domain mainly representing the area of fluid flow from reservoir boundary to the fracture domain, there exists a threshold pressure gradient. The fluid in low permeability porous media is not able to flow until the reservoir pressure gradient is greater than a minimum value. Due to the complexity of reservoir simulations for multi-frac horizontal wells in low permeability shale reservoirs, a reliable mechanistic model is needed for production engineers. The analytical solution to well performance in multi-frac horizontal wells has been studied by different researchers. None of the models considered the effect of multiple phase fluid flow. These models were further weakened by using the constant fluid properties.

This paper presents a rigorous model used to predict multi-frac horizontal well performance for low permeability reservoirs, under the effects of reservoir threshold pressure gradient and non-constant fluid properties while also considering the impact of multiphase flow through non-fracture and fracture domains. The effect of pressure dependent reservoir properties was often overlooked in multi-frac horizontal well models. In general, the significant pressure difference across the reservoir boundary and at the wellbore results in the changes of fluid viscosity, and density. The existing single phase and constant fluid property models overestimate production rates, while that predicted by the new, multi-phase model better matches the field production rate.
Study of Three Single Nucleotide Polymorphisms in the Slc6a14 Gene in Association with Male Infertility
Authors: Noveski P. , Mircevska M. , Plaseski T. , Peterlin B. , Plaseska-Karanfilska D.
Published: April 2015

Although several genetic causes of male infertility are known, the condition in around 60.0-75.0% of infertile male patients appears to be idiopathic. In some, genetic causes may be polygenic and require several low-penetrance genes to produce a phenotype outcome. In others, pleiotropy, when a gene can produce several phenotypic traits, may be involved. We have investigated whether single nucleotide polymorphisms (SNPs) in the SLC6A14 [solute carrier family 6 (amino acid transporter), member 14] gene are associated with male infertility. This gene has previously been linked with obesity and cystic fibrosis, which are associated with male infertility. It has a role in the transport of tryptophan and synthesis of serotonin that are important for normal spermatogenesis and testicular function. We have analyzed three SNPs (rs2312054, rs2071877 and rs2011162) in 370 infertile men and 241 fertile controls from two different populations (Macedonian and Slovenian). We found that the rs2011162(G) allele and rs2312054(A)- rs2071877(C)-rs2011162(G) haplotype are present at lower frequencies in the infertile rather than the fertile men (p = 0.044 and p = 0.0144, respectively). We concluded that the SLC6A14 gene may be a population-specific, low-penetrance locus which confers susceptibility to male infertility/subfertility. Additional follow-up studies of a large number of infertile men of different ethnic backgrounds are needed to confirm such a susceptibility.
Reliability Assessment of Date Transmission Systems / Szacowanie Niezawodności Systemu Przesyłu Danych
Authors: Laskowski Dariusz
Published: April 2015

The paper presents the reliability estimate of the data transmission system. In practical communication solutions this type of system is widely used. A data transfer between the sender and the receiver is a complex process taking into account the human, communication system and threats. Between these components there are many relationships and dependencies. Current methods use a selective approach to this issue. Therefore, it was decided to develop and present a comprehensive assessment of the system reliability. This method has been verified in representative conditions using commercial and open source tools
Mathematical Model and Simulator of Rotor With Vibrating Blades Model / Matematyczny I Symulator Stopnia Wirnikowego Z Drgającymi Łopatkami
Authors: Wachłaczenko Michał , Przysowa Radosław , Żokowski Mariusz
Published: April 2015

The paper presents description of rotating bladed disk mathematical model. Correctly defined mathematical model of rotor allows creation of numerical simulation model which can be used to generate tip-timing data. First of all, the model is necessary to conduct a research on blade response due to input force in form of changing rotational speed. This enables the possibility to determine turbojet engine terminal operating conditions causing its failure
Prison, Time,Kairosin Langston Hughes’sScottsboro, Limited
Authors: Ryan Katy
Published: April 2015

ABSTRACT:

Langston Hughes’s verse play Scottsboro, Limited first appeared in the November 1931 issue of New Masses. Hughes takes advantage of agit-prop’s licence to move away from the strictly factual to present a vision of social transformation. Drawing from Antonio Negri’s writing, I discuss the unclear temporal location of the first scene relative to the rest of the action, especially the final act of liberation. Critics have assumed a causal connection between the emergence of communist workers in the audience and the freedom of the Scottsboro figures, but it is the defiance of the imprisoned that strengthens the resolve of the Red Voices and dispatches the Mob. Hughes transforms a scene of private execution into a public platform of black-led revolt, remakes prison into a site of physical and spiritual resistance, and provides a kairological perspective on the U.S. carceral state.
Heat Wave Events over Georgia Since 1961: Climatology, Changes and Severity
Authors: Keggenhoff Ina , Elizbarashvili Mariam , King Lorenz
Published: April 2015

The Caucasus Region has been affected by an increasing number of heat waves during the last decades, which have had serious impacts on human health, agriculture and natural ecosystems. A dataset of 22 homogenized, daily maximum (Tmax) and minimum (Tmin) air temperature series is developed to quantify climatology and summer heat wave changes for Georgia and Tbilisi station between 1961 and 2010 using the extreme heat factor (EHF) as heat wave index. The EHF is studied with respect to eight heat wave aspects: event number, duration, participating heat wave days, peak and mean magnitude, number of heat wave days, severe and extreme heat wave days. A severity threshold for each station was determined by the climatological distribution of heat wave intensity. Moreover, heat wave series of two indices focusing on the 90th percentile of daily minimum temperature (CTN90p) and the 90th percentile of daily maximum temperature (CTX90p) were compared. The spatial distribution of heat wave characteristics over Georgia showed a concentration of high heat wave amplitudes and mean magnitudes in the Southwest. The longest and most frequently occurring heat wave events were observed in the Southeast of Georgia. Most severe heat wave events were found in both regions. Regarding the monthly distribution of heat waves, the largest proportion of severe events and highest intensities are measured during May. Trends for all Georgia-averaged heat wave aspects demonstrate significant increases in the number, intensity and duration of low- and high-intensity heat waves. However, for the heat wave mean magnitude no change was observed. Heat wave trend magnitudes for Tbilisi mainly exceed the Georgia-averages and its surrounding stations, implying urban heat island (UHI) effects and synergistic interactions between heat waves and UHIs. Comparing heat wave aspects for CTN90p and CTX90p, all trend magnitudes for CTN90p were larger, while the correlation between the annual time-series was very high among all heat wave indices analyzed. This finding reflects the importance of integrating the most suitable heat wave index into a sector-specific impact analysis.
Topical Benefits of Two Fucoidan-Rich Extracts from Marine Macroalgae
Authors: Fitton J. , Dell'Acqua Giorgio , Gardiner Vicki-Anne , Karpiniec Samuel , Stringer Damien , Davis Emma
Published: April 2015

Two concentrated and well-characterized fucoidan-rich extracts were investigated to determine their benefits in topical applications. An Undaria pinnatifida extract, containing 85% fucoidan, and a Fucus vesiculosus co-extract, containing 60% fucoidan and 30% polyphenol, were assessed in a number of in vitro assays to measure the effect of the extracts on enzyme inhibition, glycation, antioxidant activity and Sirtuin 1 (SIRT1) protein expression. Double-blind, placebo-controlled clinical studies were also conducted to measure soothing, protection, wrinkle depth, brightness and skin spot intensity. Both extracts demonstrated marked inhibitory effects on processes linked to skin aging, including the increased expression of SIRT1 in vitro. Clinical testing established the efficacy of the extracts in a range of the tested applications, relative to placebo. The Fucus vesiculosus extract with high polyphenol content demonstrated additional in vitro antioxidant activity, as well as improved efficacy in skin brightening applications, relative to placebo. The major effects of the Undaria pinnatifida extract aided skin immunity, soothing and protection, while the Fucus vesiculosus extract most significantly affected age spot reduction and increased brightness, soothing and protection.