| 1. |
- Abramowski, A., et al.
(författare)
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Constraints on the gamma-ray emission from the cluster-scale AGN outburst in the Hydra A galaxy cluster
- 2012
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 545, s. A103-
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Tidskriftsartikel (refereegranskat)abstract
- Context. In some galaxy clusters, powerful active galactic nuclei (AGN) have blown bubbles with cluster scale extent into the ambient medium. The main pressure support of these bubbles is not known to date, but cosmic rays are a viable possibility. For such a scenario copious gamma-ray emission is expected as a tracer of cosmic rays from these systems. Aims. Hydra A, the closest galaxy cluster hosting a cluster scale AGN outburst, located at a redshift of 0.0538, is investigated for being a gamma-ray emitter with the High Energy Stereoscopic System (H.E.S.S.) array and the Fermi Large Area Telescope (Fermi-LAT). Methods. Data obtained in 20.2 h of dedicated H. E. S. S. observations and 38 months of Fermi-LAT data, gathered by its usual all-sky scanning mode, have been analyzed to search for a gamma-ray signal. Results. No signal has been found in either data set. Upper limits on the gamma-ray flux are derived and are compared to models. These are the first limits on gamma-ray emission ever presented for galaxy clusters hosting cluster scale AGN outbursts. Conclusions. The non-detection of Hydra A in gamma-rays has important implications on the particle populations and physical conditions inside the bubbles in this system. For the case of bubbles mainly supported by hadronic cosmic rays, the most favorable scenario, which involves full mixing between cosmic rays and embedding medium, can be excluded. However, hadronic cosmic rays still remain a viable pressure support agent to sustain the bubbles against the thermal pressure of the ambient medium. The largest population of highly-energetic electrons, which are relevant for inverse-Compton gamma-ray production is found in the youngest inner lobes of Hydra A. The limit on the inverse-Compton gamma-ray flux excludes a magnetic field below half of the equipartition value of 16 mu G in the inner lobes.
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| 2. |
- Power, M. J., et al.
(författare)
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Changes in fire regimes since the Last Glacial Maximum : an assessment based on a global synthesis and analysis of charcoal data
- 2008
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Ingår i: Climate Dynamics. - : Springer Science and Business Media LLC. - 0930-7575 .- 1432-0894. ; 30:7-8, s. 887-907
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Tidskriftsartikel (refereegranskat)abstract
- Fire activity has varied globally and continuously since the last glacial maximum (LGM) in response to long-term changes in global climate and shorter-term regional changes in climate, vegetation, and human land use. We have synthesized sedimentary charcoal records of biomass burning since the LGM and present global maps showing changes in fire activity for time slices during the past 21,000 years (as differences in charcoal accumulation values compared to pre-industrial). There is strong broad-scale coherence in fire activity after the LGM, but spatial heterogeneity in the signals increases thereafter. In North America, Europe and southern South America, charcoal records indicate less-than-present fire activity during the deglacial period, from 21,000 to ∼11,000 cal yr BP. In contrast, the tropical latitudes of South America and Africa show greater-than-present fire activity from ∼19,000 to ∼17,000 cal yr BP and most sites from Indochina and Australia show greater-than-present fire activity from 16,000 to ∼13,000 cal yr BP. Many sites indicate greater-than-present or near-present activity during the Holocene with the exception of eastern North America and eastern Asia from 8,000 to ∼3,000 cal yr BP, Indonesia and Australia from 11,000 to 4,000 cal yr BP, and southern South America from 6,000 to 3,000 cal yr BP where fire activity was less than present. Regional coherence in the patterns of change in fire activity was evident throughout the post-glacial period. These complex patterns can largely be explained in terms of large-scale climate controls modulated by local changes in vegetation and fuel load.
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| 3. |
- Jabado, Rima W., et al.
(författare)
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Troubled waters : Threats and extinction risk of the sharks, rays and chimaeras of the Arabian Sea and adjacent waters
- 2018
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Ingår i: Fish and Fisheries. - : Wiley-Blackwell. - 1467-2960 .- 1467-2979. ; 19:6, s. 1043-1062
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Tidskriftsartikel (refereegranskat)abstract
- The extinction risk of sharks, rays and chimaeras is higher than that for most other vertebrates due to low intrinsic population growth rates of many species and the fishing intensity they face. The Arabian Sea and adjacent waters border some of the most important chondrichthyan fishing and trading nations globally, yet there has been no previous attempt to assess the conservation status of species occurring here. Using IUCN Red List of Threatened Species Categories and Criteria and their guidelines for application at the regional level, we present the first assessment of extinction risk for 153 species of sharks, rays and chimaeras. Results indicate that this region, home to 15% of described chondrichthyans including 30 endemic species, has some of the most threatened chondrichthyan populations in the world. Seventy-eight species (50.9%) were assessed as threatened (Critically Endangered, Endangered or Vulnerable), and 27 species (17.6%) as Near Threatened. Twenty-nine species (19%) were Data Deficient with insufficient information to assess their status. Chondrichthyan populations have significantly declined due to largely uncontrolled and unregulated fisheries combined with habitat degradation. Further, there is limited political will and national and regional capacities to assess, manage, conserve or rebuild stocks. Outside the few deepsea locations that are lightly exploited, the prognosis for the recovery of most species is poor in the near-absence of management. Concerted national and regional management measures are urgently needed to ensure extinctions are avoided, the sustainability of more productive species is secured, and to avoid the continued thinning of the regional food security portfolio.
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| 4. |
- Ilyas, Muhammad Tasaduq, et al.
(författare)
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Substantial performance of copper sulfide nanotubes at high current densities for energy storage applications
- 2024
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Ingår i: Journal of Energy Storage. - : Elsevier. - 2352-152X .- 2352-1538. ; 85
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Tidskriftsartikel (refereegranskat)abstract
- This study presents the direct growth of CuS nanotubes (NTs) on nickel foam using a facile solution synthesis route. The structural, elemental and morphological analyses of CuS NTs grown Ni foam were conducted through X-ray diffraction, energy dispersive X-ray spectroscopy, scanning electron microscope, and field emission scanning electron microscope. The electrochemical performance of the prepared electrodes was comprehensively characterized by cyclic voltammetry (CV), galvanostatic charge discharge and electrochemical impedance spectroscopy. The CuS NTs grown electrodes delivered a specific capacitance of 1539 Fg−1 at 1 mVs−1 and 1365 Fg−1 at 5 Ag−1, demonstrating a remarkable rate capability of 66 % at an extremely high current density of 25 Ag−1. Notably, the CuS NTs electrode demonstrated good cyclic stability, as evidenced by a charge retention of 75.5 % after 3000 cycles at a high current density of 20 Ag−1. The charge storage mechanism was predominantly diffusion controlled, accomplished by analyzing CV data. Overall, this work evinces that the as-synthesized CuS NTs hold a significant promise as electrode materials for high-performance electrochemical energy storage applications.
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| 5. |
- Abdulhadi, Nadia M. Noor, et al.
(författare)
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Doctors' and nurses' views on patient care for type 2 diabetes : an interview study in primary health care in Oman
- 2013
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Ingår i: Primary Health Care Research and Development. - : Cambridge University Press. - 1463-4236 .- 1477-1128. ; 14:3, s. 258-269
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Tidskriftsartikel (refereegranskat)abstract
- Aim: This study aimed at exploring the experiences of primary health-care providers of their encounters with patients with type 2 diabetes, and their preferences and suggestions for future improvement of diabetes care. Background: Barriers to good diabetes care could be related to problems from health-care providers' side, patients' side or the healthcare system of the country. Treatment of patients with type 2 diabetes has become a huge challenge in Oman, where the prevalence has increased to high levels. Method: Semi-structured interviews were conducted with 26 health-care professionals, 19 doctors and seven nurses, who worked in primary health care in Oman. Qualitative content analysis was applied. Findings: Organizational barriers and barriers related to patients and healthcare providers were identified. These included workload and lack of teamwork approach. Poor patients' management adherence and influence of culture on their attitudes towards illness were identified. From the providers' side, language barriers, providers' frustration and aggressive attitudes towards the patients were reflected. Decreasing the workload, availability of competent teams with diabetes specialist nurses and continuity of care were suggested. Furthermore, changing professional behaviours towards a more patient-centred approach and need for health education to the patients, especially on self-management, were addressed. Appropriate training for health-care providers in communication skills with emphasis on self-care education and individualization of care according to each patient's needs are important for improvement of diabetes care in Oman.
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| 6. |
- Ahmad, Waqar, et al.
(författare)
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Thermophysical Study of Binary Systems of tert-Amyl Methyl Ether with n-Hexane and m-Xylene
- 2019
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 64:2, s. 459-470
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Tidskriftsartikel (refereegranskat)abstract
- This work presents the experimentally determined density (rho), viscosity (eta), speed of sound (u), and surface tension (sigma) data for tert-amyl methyl ether (TAME) + n-hexane and TAME + m-xylene systems at several temperatures (298.15, 308.15, 318.15, 323.15, and 328.15 K). These experimentally determined thermophysical data are utilized to compute various excess/deviation parameters such as molar volume (V-E), isentropic compressibility (K-s(E)), speed of sound (u(E)), deviation in viscosity (Delta In eta), isobaric thermal expansion coefficient (alpha(E)(P)), and surface tension (sigma(E)). The inspection of parameters response may interpret the existing specific molecular interactions as well as the mixing behavior of solutions. The critical analysis of observed parametric behavior have unveiled the strong and weak molecular interactions in TAME with m-xylene and TAME with n-hexane systems, respectively.
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| 7. |
- Ahmed, Ali M., Professor, 1977-, et al.
(författare)
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Are people fuzzy about who they work with? : An experimental test of Becker’s coworker discrimination hypothesis
- 2021
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Ingår i: The Social Science Journal. - Amsterdam : Taylor & Francis. - 0362-3319 .- 1873-5355. ; 58:4, s. 477-483
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Tidskriftsartikel (refereegranskat)abstract
- We used an experiment to investigate whether people’s decisions over employment opportunities are affected by the ethnicity and sex of their potential future coworkers. University students (N = 1,406) were asked to state the lowest hourly wage rate at which they would be willing to accept a job on a campus food truck, where they would work alongside the food truck owner. The ethnicity and sex of the food truck owners were randomized across participants. Results showed no signs of coworker prejudice in terms of the probability of being interested in the job and reservation wage.
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| 8. |
- Ahmed, Ali M., 1977-
(författare)
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Can education affect pro-social behavior? : Cops, economists and humanists in social dilemmas
- 2008
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Ingår i: International Journal of Social Economics. - : Emerald Group Publishing Limited. - 0306-8293 .- 1758-6712. ; 35:4, s. 298-307
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Tidskriftsartikel (refereegranskat)abstract
- Purpose – The purpose of this paper is to examine whether education and training affect pro-social behavior. Economics students are often accused of being less pro-social. The explanations given are that less pro-social people choose to study economics or that economics studies indoctrinate students to selfish behavior. The paper experimentally tests these postulations.Design/methodology/approach – The paper uses the prisoner's dilemma game and stag hunt game to study cooperation across different groups of students.Findings – The experiment supports neither of the postulations: economics students would be indoctrinated or less pro-social people choose to study economics. However, the study shows that police cadets, who go through an education where teamwork and cooperation is promoted, become more cooperative and pro-social after their completed education.Originality/value – In contrast to earlier studies, this paper does not simply study economics students, but also examines if students in educational programs that promote loyalty and cooperation and encourage teamwork are more pro-social than other students.
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| 9. |
- Ahmed, Ali M., 1977-
(författare)
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Decisions under unpredictable losses : An examination of the restated diversification principle
- 2007
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Ingår i: Judgment and Decision Making. - : Society forJudgement and Decision Making. - 1930-2975. ; 2:5, s. 312-316
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Tidskriftsartikel (refereegranskat)abstract
- An experimental test of the descriptive adequacy of the restated diversification principle is presented. The principle postulates that risk-averse utility maximizers will pool risks for their mutual benefit, even if information is missing about the probabilities of losses. It is enough for people to assume that they face equal risks when they pool risks. The results of the experiment support the principle.
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| 10. |
- Ahmed, Ali M., Professor, 1977-, et al.
(författare)
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Diskriminerar kunder utrikes födda företagare? Resultat från ett webb-baserat experiment
- 2018
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Ingår i: Ekonomisk Debatt. - Stockholm, Sweden : Research Institute of Industrial Economics. - 0345-2646. ; 46:7, s. 25-32
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Vi presenterar resultat från ett experiment utfört på ett universitetscampus.Deltagarna fick se bilder av olika food-trucks och svara på om de tyckte det varen god idé att en food-truck etablerade sig på campusområdet samt ange sinbetalningsvilja för olika varor. Deltagarna i experimentet var mer positivatill en etablering av en food-truck ägd av en man med arabiskt namn än till enetablering av en food-truck ägd av en man med svenskt namn. Resultaten är avintresse för integrationspolitiken, då de visar att egenföretagare med ursprung iMellanöstern inte diskrimineras i en bransch där de ofta är verksamma.
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