201,768 research outputs found
Characterization of Crude Oils and Asphaltenes for Al-Shaheen Field
No full textAl Shaheen field is the largest oil producing field in Qatar. It is considered as an important strategic asset for the economic growth of Qatar. Hence, it is crucial for the country to explore and analyze ways that could optimize the development process in this oilfield. Scientists and scholars have not been able to completely segregate the crude oil into individual components. Also, huge variations are found in the chemical composition of crude oil from oilfield to oilfield and from region to region. Hence, there is a need of conducting a focused study for the characterization of crude oil and asphaltenes in the context of Al Shaheen field. It is not possible to use experimental data for analytical purposes due to its large volume and the complexities involved. Hence, the researchers use cubic equations of state to predict the composition and behavior of crude oils in different oilfields. Maersk Oil Qatar is operating Al Shaheen field at present under a 25 year agreement with Qatar Petroleum. The company is using Peng Robinson Equation of State for the characterization of crude oil. This study recommends expanding the match of EOS from C20 plus (currently used by Maersk Oil) to C60 plus extended oil analysis using the Peng-Robinson equation. The new approach is expected to address accuracy problems, if there are any, particularly evident for very heavy crude oils
Covers for S-acts and condition (A) for a monoid S
No full textA monoid S satisfies Condition (A) if every locally cyclic left S-act is cyclic. This condition first arose in Isbell’s work on left perfect monoids, that is, monoids such that every left S-act has a projective cover. Isbell showed that S is left perfect if and only if every cyclic left S-act has a projective cover and Condition (A) holds. Fountain built on Isbell’s work to show that S is left perfect if and only if it satisfies Condition (A) together with the descending chain condition on principal right ideals, MR. We note that a ring is left perfect (with an analogous definition) if and only if it satisfies MR. The appearance of Condition (A) in this context is therefore monoid specific.Condition (A) has a number of alternative characterisations, in particular, it is equivalent to the ascending chain condition on cyclic subacts of any left S-act. In spite of this, it remains somewhat esoteric. The first aim of this article is to investigate the preservation of Condition (A) under basic semigroup-theoretic constructions.Recently, Khosravi, Ershad and Sedaghatjoo have shown that every left S-act has a strongly flat or Condition (P) cover if and only if every cyclic left S-act has such a cover and Condition (A) holds. Here we find a range of classes of S-acts C such that every left S-act has a cover from C if and only if every cyclic left S-act does and Condition (A) holds. In doing so we find a further characterisation of Condition (A) purely in terms of the existence of covers of a certain kind.Finally, we make some observations concerning left perfect monoids and investigate a class of monoids close to being left perfect, which we name left IPa-perfect
Visual size estimates of whale sharks from Al Shaheen.
No full textVisual size estimates of whale sharks from Al Shaheen.</p
On Optimal Agendas for Multi-Issue Negotiation
No full textThis paper analyzes bilateral multi-issue negotiation where the issues are divisible, there are time constraints in the form of deadlines and discount factors, and the agents have different preferences over the issues. The issues are negotiated using the package deal procedure. The set of issues to be negotiated is a choice variable in that the agents can decide what issues to negotiate. This set is called the negotiation agenda. Since the outcome of negotiation depends on the agenda, it is important to determine what agenda maximizes an agent’s utility and is therefore its optimal agenda. To this end, this paper presents polynomial time methods for finding an agent’s optimal agenda
Eclipse (Grohon kal)
No full textIn Bangladeshi with English subtitlesProducer: Shaheen AkhtarDirectors: Shaheen Akhtar, Shameen Akhtar and Makbul ChowdhuryStories of Muslim women who have committed suicide in the wake of fatwas in Bangladesh, and the activists who strive for the prohibition of these religious ruling
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
Inter-annual re-sight rates (%) for individual sharks first identified in Al Shaheen.
No full textInter-annual re-sight rates (%) for individual sharks first identified in Al Shaheen.</p
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