856 resultados para Exploration and Recovery Process in Oil Fields


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This research examines the process of placemaking in LeDroit Park, a residential Washington, DC, neighborhood with a historic district at its core. Unpacking the entwined physical and social evolution of the small community within the context of the Nation’s Capital, this analysis provides insight into the role of urban design and development as well as historic designation on shaping collective identity. Initially planned and designed in 1873 as a gated suburb just beyond the formal L’Enfant-designed city boundary, LeDroit Park was intended as a retreat for middle and upper-class European Americans from the growing density and social diversity of the city. With a mixture of large romantic revival mansions and smaller frame cottages set on grassy plots evocative of an idealized rural village, the physical design was intentionally inwardly-focused. This feeling of refuge was underscored with a physical fence that surrounded the development, intended to prevent African Americans from nearby Howard University and the surrounding neighborhood, from using the community’s private streets to access the City of Washington. Within two decades of its founding, LeDroit Park was incorporated into the District of Columbia, the surrounding fence was demolished, and the neighborhood was racially integrated. Due to increasingly stringent segregation laws and customs in the city, this period of integration lasted less than twenty years, and LeDroit Park developed into an elite African American enclave, using the urban design as a bulwark against the indignities of a segregated city. Throughout the 20th century housing infill and construction increased density, yet the neighborhood never lost the feeling of security derived from the neighborhood plan. Highlighting the architecture and street design, neighbors successfully received historic district designation in 1974 in order to halt campus expansion. After a stalemate that lasted two decades, the neighborhood began another period of transformation, both racial and socio-economic, catalyzed by a multi-pronged investment program led by Howard University. Through interviews with long-term and new community members, this investigation asserts that the 140-year development history, including recent physical interventions, is integral to placemaking, shaping the material character as well as the social identity of residents.

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In refrigeration systems a small amount of compressor lubricant is entrained in the refrigerant and circulated through the system, where some is retained in each component. The suction line to the compressor has the largest potential for oil retention. This paper presents results from an experimental apparatus that has been constructed to circulate POE (polyolester) oil and R410A at a controlled mass flux, OCR (oil in circulation ratio), and apparent superheat, and to directly measure the pressure drop and mass of oil retained in horizontal and vertical suction lines. The bulk vapor velocity and overall void fraction are determined from direct mass and temperature measurements. The oil retention, pressure drop, and flow regimes near the minimum ASHRAE recommended mass flux condition are explored. It was found that oil retention begins to increase sharply even above the minimum recommended flux, so conditions near the minimum should be avoided. Two relationships were developed to predict the oil retention in the vertical and horizontal suction lines. The average error from the predictions method was 10.9% for the vertical tube, and 7.9% for the horizontal tube.

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Applications are subject of a continuous evolution process with a profound impact on their underlining data model, hence requiring frequent updates in the applications' class structure and database structure as well. This twofold problem, schema evolution and instance adaptation, usually known as database evolution, is addressed in this thesis. Additionally, we address concurrency and error recovery problems with a novel meta-model and its aspect-oriented implementation. Modern object-oriented databases provide features that help programmers deal with object persistence, as well as all related problems such as database evolution, concurrency and error handling. In most systems there are transparent mechanisms to address these problems, nonetheless the database evolution problem still requires some human intervention, which consumes much of programmers' and database administrators' work effort. Earlier research works have demonstrated that aspect-oriented programming (AOP) techniques enable the development of flexible and pluggable systems. In these earlier works, the schema evolution and the instance adaptation problems were addressed as database management concerns. However, none of this research was focused on orthogonal persistent systems. We argue that AOP techniques are well suited to address these problems in orthogonal persistent systems. Regarding the concurrency and error recovery, earlier research showed that only syntactic obliviousness between the base program and aspects is possible. Our meta-model and framework follow an aspect-oriented approach focused on the object-oriented orthogonal persistent context. The proposed meta-model is characterized by its simplicity in order to achieve efficient and transparent database evolution mechanisms. Our meta-model supports multiple versions of a class structure by applying a class versioning strategy. Thus, enabling bidirectional application compatibility among versions of each class structure. That is to say, the database structure can be updated because earlier applications continue to work, as well as later applications that have only known the updated class structure. The specific characteristics of orthogonal persistent systems, as well as a metadata enrichment strategy within the application's source code, complete the inception of the meta-model and have motivated our research work. To test the feasibility of the approach, a prototype was developed. Our prototype is a framework that mediates the interaction between applications and the database, providing them with orthogonal persistence mechanisms. These mechanisms are introduced into applications as an {\it aspect} in the aspect-oriented sense. Objects do not require the extension of any super class, the implementation of an interface nor contain a particular annotation. Parametric type classes are also correctly handled by our framework. However, classes that belong to the programming environment must not be handled as versionable due to restrictions imposed by the Java Virtual Machine. Regarding concurrency support, the framework provides the applications with a multithreaded environment which supports database transactions and error recovery. The framework keeps applications oblivious to the database evolution problem, as well as persistence. Programmers can update the applications' class structure because the framework will produce a new version for it at the database metadata layer. Using our XML based pointcut/advice constructs, the framework's instance adaptation mechanism is extended, hence keeping the framework also oblivious to this problem. The potential developing gains provided by the prototype were benchmarked. In our case study, the results confirm that mechanisms' transparency has positive repercussions on the programmer's productivity, simplifying the entire evolution process at application and database levels. The meta-model itself also was benchmarked in terms of complexity and agility. Compared with other meta-models, it requires less meta-object modifications in each schema evolution step. Other types of tests were carried out in order to validate prototype and meta-model robustness. In order to perform these tests, we used an OO7 small size database due to its data model complexity. Since the developed prototype offers some features that were not observed in other known systems, performance benchmarks were not possible. However, the developed benchmark is now available to perform future performance comparisons with equivalent systems. In order to test our approach in a real world scenario, we developed a proof-of-concept application. This application was developed without any persistence mechanisms. Using our framework and minor changes applied to the application's source code, we added these mechanisms. Furthermore, we tested the application in a schema evolution scenario. This real world experience using our framework showed that applications remains oblivious to persistence and database evolution. In this case study, our framework proved to be a useful tool for programmers and database administrators. Performance issues and the single Java Virtual Machine concurrent model are the major limitations found in the framework.

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Many maritime countries in Europe have implemented marine environmental monitoring programmes which include the measurement of chemical contaminants and related biological effects. How best to integrate data obtained in these two types of monitoring into meaningful assessments has been the subject of recent efforts by the International Council for Exploration of the Sea (ICES) Expert Groups. Work within these groups has concentrated on defining a core set of chemical and biological endpoints that can be used across maritime areas, defining confounding factors, supporting parameters and protocols for measurement. The framework comprised markers for concentrations of, exposure to and effects from, contaminants. Most importantly, assessment criteria for biological effect measurements have been set and the framework suggests how these measurements can be used in an integrated manner alongside contaminant measurements in biota, sediments and potentially water. Output from this process resulted in OSPAR Commission (www.ospar.org) guidelines that were adopted in 2012 on a trial basis for a period of 3 years. The developed assessment framework can furthermore provide a suitable approach for the assessment of Good Environmental Status (GES) for Descriptor 8 of the European Union (EU) Marine Strategy Framework Directive (MSFD).

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This thesis compares contemporary anglophone and francophone rewritings of traditional fairy tales for adults. Examining material dating from the 1990s to the present, including novels, novellas, short stories, comics, televisual and filmic adaptations, this thesis argues that while the revisions studied share similar themes and have comparable aims, the methods for inducing wonder (where wonder is defined as the effect produced by the text rather than simply its magical contents) are diametrically opposed, and it is this opposition that characterises the difference between the two types of rewriting. While they all engage with the hybridity of the fairy-tale genre, the anglophone works studied tend to question traditional narratives by keeping the fantasy setting, while francophone works debunk the tales not only in relation to questions of content, but also aesthetics. Through theoretical, historical, and cultural contextualisation, along with close readings of the texts, this thesis aims to demonstrate the existence of this francophone/anglophone divide and to explain how and why the authors in each tradition tend to adopt such different views while rewriting similar material. This division is the guiding thread of the thesis and also functions as a springboard to explore other concepts such as genre hybridity, reader-response, and feminism. The thesis is divided into two parts; the first three chapters work as an in-depth literature review: after examining, in chapters one and two, the historical and contemporary cultural field in which these works were created, chapter three examines theories of fantasy and genre hybridity. The second part of the thesis consists of textual studies and comparisons between francophone and anglophone material and is built on three different approaches. The first (chapter four) looks at selected texts in relation to questions of form, studying the process of world building and world creation enacted when authors combine and rewrite several fairy tales in a single narrative world. The second (chapter five) is a thematic approach which investigates the interactions between femininity, the monstrous, and the wondrous in contemporary tales of animal brides. Finally, chapter six compares rewritings of the tale of ‘Bluebeard’ with a comparison hinged on the representation of the forbidden room and its contents: Bluebeard’s cabinet of wonder is one that he holds sacred, one where he sublimates his wives’ corpses, and it is the catalyst of wonder, terror, and awe. The three contextual chapters and the three text-based studies work towards tracing the tangible existence of the division postulated between francophone and anglophone texts, but also the similarities that exist between the two cultural fields and their roles in the renewal of the fairy-tale genre.

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Background: Research suggests that forensic mental health services and staff can play an important role in the recognition and intervention with attachment-related behaviours to promote engagement and recovery. There is a lack of literature exploring whether the attachment needs of forensic service-users are recognised and, associations between attachment style and factors predictive of recovery. Aims: This study aimed to examine the extent to which service-users and keyworkers agree about service-users’ attachment and to identify whether attachment was associated with service attachment, working alliance, ward climate and recovery. Methods: Twenty-two service-users from low and medium secure forensic services, completed questionnaire measures of their attachment style, service attachment, working alliance, ward climate and experiences of recovery. Nineteen keyworkers completed measures of the service-users attachment style and working alliance. Results: There was strong agreement between service-users and staff for attachment anxiety (ICC=0.71) but poor agreement for attachment avoidance (ICC=0.39). Service attachment was associated with more positive perceptions of staff support (r=0.49) and avoidant attachment was associated with lower ratings of recovery (r=-0.51). Correlations between attachment style and service attachment, working alliance and ward climate were small and non-significant. Conclusions: A focus on staff training to support recognition of the nature and impact of avoidant attachment styles is indicated. The findings suggest that interventions to enhance staff - service-user relationships may be important for service attachment and indeed promotion of a recovery focused orientation amongst service-users high in avoidant attachment may improve wellbeing and outcomes.

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Background: The Analytic Hierarchy Process (AHP), developed by Saaty in the late 1970s, is one of the methods for multi-criteria decision making. The AHP disaggregates a complex decision problem into different hierarchical levels. The weight for each criterion and alternative are judged in pairwise comparisons and priorities are calculated by the Eigenvector method. The slowly increasing application of the AHP was the motivation for this study to explore the current state of its methodology in the healthcare context. Methods: A systematic literature review was conducted by searching the Pubmed and Web of Science databases for articles with the following keywords in their titles or abstracts: "Analytic Hierarchy Process," "Analytical Hierarchy Process," "multi-criteria decision analysis," "multiple criteria decision," "stated preference," and "pairwise comparison." In addition, we developed reporting criteria to indicate whether the authors reported important aspects and evaluated the resulting studies' reporting. Results: The systematic review resulted in 121 articles. The number of studies applying AHP has increased since 2005. Most studies were from Asia (almost 30 %), followed by the US (25.6 %). On average, the studies used 19.64 criteria throughout their hierarchical levels. Furthermore, we restricted a detailed analysis to those articles published within the last 5 years (n = 69). The mean of participants in these studies were 109, whereas we identified major differences in how the surveys were conducted. The evaluation of reporting showed that the mean of reported elements was about 6.75 out of 10. Thus, 12 out of 69 studies reported less than half of the criteria. Conclusion: The AHP has been applied inconsistently in healthcare research. A minority of studies described all the relevant aspects. Thus, the statements in this review may be biased, as they are restricted to the information available in the papers. Hence, further research is required to discover who should be interviewed and how, how inconsistent answers should be dealt with, and how the outcome and stability of the results should be presented. In addition, we need new insights to determine which target group can best handle the challenges of the AHP. © 2015 Schmidt et al.

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Presumed synergistic effect of combined amendment of crude oil spiked soil with oil palm bunch ash and sawdust was carried out in a laboratory experiment. Two kilogram (2 kg) of sandy soil was placed in each of five plastic vessels labeled TA, TB, TC, TD and TE. TA was left in its natural state while the others were each polluted with 6.7% v/w of crude oil. TB was not given any remediation amendment. TC and TD were each amended with 13.3% of oil palm bunch ash and sawdust respectively while TE was amended with 13.3% each of oil palm bunch ash and sawdust. The setups were replicated five times and watered twice weekly. Results showed that soil pH increased from 8.7±0.04 to 10.5±0.06, 5.3±0.01 to 8.5±0.04 and 5.6±0.18 to 11.5±0.15 for TC, TD and TE respectively. Percentage total petroleum hydrocarbon contents reduced by 65% for TC, TD and 52% for TE. Total organic carbon increased from 7.6±0.7 to 8.5±0.5%%, reduced from 4.0±0.1% to 3.7±0.3% and from 4.1±0.1% to 2.2±1.0% TC, TD and TE respectively. Total nitrogen increased from 0.66±0.1 to 0.69±0.0% for TC, remained nearly the same for TD and reduced from 0.4±0.0 to 0.2±0.0% for TE while average phosphorus increased from 0.4±0.0 to 23.0±4.2 mg/kg, 0.3±0.0 to 1.8±0.4 mg/kg and from 0.2±1.0 mg/kg to 52.6±4.6 mg/kg for TC, TD and TE respectively. Conclusively, combined amendment with oil palm bunch ash and sawdust did not induce synergism in soil total petroleum hydrocarbon content reduction.

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Despite growing concern about transgenes escaping from fields, few studies have analysed the genetic diversity of crops in an agroecosystem over several years. Accurate information about the dynamics and relationship of the genetic diversity of crops in an agroecosystem is essential for risk assessment and policies concerning the containment of genetically modified crops and their coexistence with crops grown by conventional practices. Here, we analysed the genetic diversity of oilseed rape plants from fields and feral populations over 4 years in an agricultural landscape of 41 km2. We used exact compatibility and maximum likelihood assignment methods to assign these plants to cultivars. Even pure lines and hybrid cultivar seed lots contained several genotypes. The cultivar diversity in fields reflected the conventional view of agroecosystems quite well: that is, there was a succession of cultivars, some grown for longer than others because of their good performance, some used for one year and then abandoned, and others gradually adopted. Three types of field emerged: fields sown with a single cultivar, fields sown with two cultivars, and unassigned fields (too many cultivars or unassigned plants to reliably assign the field). Field plant diversity was higher than expected, indicating the persistence of cultivars that were grown for only one year. The cultivar composition of feral populations was similar to that of field plants, with an increasing number of cultivars each year. By using genetic tools, we found a link between the cultivars of field plants in a particular year and the cultivars of feral population plants in the following year. Feral populations on road verges were more diverse than those on path verges. All of these findings are discussed in terms of their consequences in the context of coexistence with genetically modified crops.

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Purpose: To formulate the water in oil (W/O) emulsion of corn silk (CS) extract and to evaluate its stability at various storage conditions. Methods: Ethanol CS extract was prepared using maceration (cold) technique. A 4 % CS emulsion was prepared using varying concentrations of liquid paraffin, ABIL EM90 and water. The formulations were kept at 40 oC for 28 days and to screen out the less stable formulations. The remaining formulations were further stressed at 50 oC to choose the most stable formulation. The optimized formulation was evaluated for physical characteristics including phase separation, rheology and mean droplet size. The physical stability of the formulation was evaluated by monitoring these parameters over a period of 12 weeks at 8, 25, 40 and 40 oC, and 75 % RH. Results: The chosen formulation showed good resistance to phase separation on centrifugation under all storage conditions. Rheological behavior followed non-Newtonian pseudoplastic pattern at various storage conditions. Mean droplet size of freshly prepared formulation was 2.98 ± 1.32 µm and did not show significant (p < 0.05) changes at normal storage conditions (8 and 25 oC). Conclusion: The findings indicate that the developed CS extract W/O emulsion is stable and therefore may be suitable for topical use on skin as an antioxidant preparation.