1,903 research outputs found
Signatures for doubly-charged Higgsinos at colliders
Several supersymmetric models with extended gauge structures predict light
doubly-charged Higgsinos. Their distinctive signature at the large hadron
collider is highlighted by studying their production and decay characteristics.Comment: 3 pages, 4 figures, Latex. Submitted for SUSY 2008 proceeding
General Complementarities on Complete Partial Orders
Cataloged from PDF version of article.This paper proves the existence of a Nash equilibrium for extended (semi-) uniform g-modular games, i.e., non-cooperative games where the strategy space is a complete partially ordered set, and the best reply correspondence satisfies certain monotonicity requirements
General complementarities on complete partial orders
This paper proves the existence of a Nash equilibrium for extended (semi-) uniform g-modular games, i.e., non-cooperative games where the strategy space is a complete partially ordered set, and the best reply correspondence satisfies certain monotonicity requirements. © 2014 Keskin et al.; licensee Springer
Investigating the roughness effect of biofouling on propeller performance
As a result of the increasing pressure being placed on the marine industry to address ship emissions, regulations to govern the fuel efficiency and efficient operation of ships in the form of the Energy Efficiency Design Index (EEDI) (IMO, 2014) and Energy Efficiency Operation Index (EEOI) (IMO, 2009a) have recently come into force. These have been introduced alongside regulations concerning specific emissions requirements (UNFCCC). Attention has therefore been turned to all aspects of ship design and operation which have impact on their efficiency. In turn, this paper focuses on the effects of biofouling on propeller surfaces highlighting the benefits of reducing biofouling. This subject was the focus of a recently completed EU-Funded FP7 Project entitled FOUL-X-SPEL (2011). This paper investigates the detrimental impacts of biofouling on the performance of a real ship propeller using Computational Fluid Dynamics (CFD) simulations. Initially, the CFD approach used in this study was validated through CFD open-water tests of a propeller. A previously-developed CFD approach for approximating the surface roughness that results from biofouling has then been applied in order to predict the effects on propeller efficiency. The roughness effects of a typical coating and different fouling conditions on the propeller performance were therefore predicted for various advance coefficients Results indicated negative effects of biofouling on the propeller efficiency and the importance of the mitigation of such effects, supporting the importance of informing the industry about the impacts such that they are able to make informed decisions regarding regular propeller maintenance and cleanin
Multi-domain active sound control and noise shielding
This paper describes an active sound control methodology based on difference potentials. The main feature of this methodology is its ability to automatically preserve “wanted” sound within a domain while canceling “unwanted” noise from outside the domain. This method of preservation of the wanted sounds by active shielding control is demonstrated with various broadband and realistic sound sources such as human voice and music in multiple domains in a one-dimensional enclosure. Unlike many other conventional active control methods, the proposed approach does not require the explicit characterization of the wanted sound to be preserved. The controls are designed based on the measurements of the total field on the boundaries of the shielded domain only, which is allowed to be multiply connected. The method is tested in a variety of experimental cases. The typical attenuation of the unwanted noise is found to be about 20 dB over a large area of the shielded domain and the original wanted sound field is preserved with errors of around 1 dB and below through a broad frequency range up to 1 kHz.
© 2011 Acoustical Society of Americ
Phosphorus and humic acid application alleviate salinity stress of pepper seedling
Humic acid is a commercial product that contains many elements which improve the soil fertility and increase the availability of nutrient elements. It consequently affects plant growth and yield and ameliorates the deleterious effects of salt stress. The objective of the study was to determine the effect of humic acids and phosphorus on growth and nutrient content of pepper seedlings (cv. Demre) grown under moderate salt stress in growth chamber conditions. Applications of different levels of phosphorus [0 (P0), 50 (P1), 100 (P2) and 150 (P3) mg kg-1] and humic acid [0 (HA0), 750 (HA1) and 1500 (HA2) mg kg-1] to growing media containing moderate salt dose (8 mM NaCl treatment) were studied. The study was replicated four times with 20 plants in each replicate. Humic acid (HA) and phosphorus applications increased the growth and growth parameter of plants. In company, effects of HA and P application was more effective on growth and growth parameter than each separate effect. The optimum total yield was obtained from 69 mg kg-1 P application with HA2 doses according to regression analysis. Humic acid application significantly increased N, P, K, Ca, Mg, S, Mn and Cu contents of shoot of pepper seedling. Also, N, P, K, Ca, S, Fe, Mn, Zn and Cu contents of root were increased with humic acid application. Na contents of both shoot and root of pepper decreased with increased humic acid doses. It can be concluded that high humic acid doses has positive effects on salt tolerance based on the plant growth parameters and nutrient contents. The present study suggests that HA treatments can ameliorate the deleterious effects of salt stress on pepper plants and HA could offer an economical and simple application to reduce problems of pepper production in moderately saline soil.Keywords: Nutrient uptake, plant growth parameter, salt stress, pepperAfrican Journal of Biotechnology Vol. 9(36), pp. 5845-5851, 6 September, 201
HPC and CFD in the marine industry: past, present and future
This paper explores the use of Computational Fluid Dynamics (CFD) applications on High Performance Computing (HPC) platforms from the perspective of a user engaged in Naval Architecture research. The paper will consider the significant limitations which were imposed on research boundaries prior to present HPC capabilities, how this impacted development in the field and the implications for industry. One particular example is the costly experimental testing which, due to resource constraints, is generally restricted to model scale. It will then present an overview of the numerical simulation capabilities using current HPC performance and capability. With the increase of computational power and capacity, CFD simulations are proving to be more accurate and reliable. Being relatively cheaper and more time efficient, numerical methods are becoming the preferred choice within the industry compared to traditional experimental tests. Nevertheless, certain experimental procedures cannot be numerically replicated with the current levels of computational capacity. The future needs and challenges of research and development will be outlined and discussed, highlighting the significant impact exascale computing will have in the field
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Knowing loved ones' end-of-life health care wishes: Attachment security predicts caregivers' accuracy.
Objective: At times, caregivers make life-and-death decisions for loved ones. Yet very little is known about the factors that make caregivers more or less accurate as surrogate decision makers for their loved ones. Previous research suggests that in low stress situations, individuals with high attachment-related anxiety are attentive to their relationship partners' wishes and concerns, but get overwhelmed by stressful situations. Individuals with high attachment-related avoidance are likely to avoid intimacy and stressful situations altogether. We hypothesized that both of these insecure attachment patterns limit surrogates' ability to process distressing information and should therefore be associated with lower accuracy in the stressful task of predicting their loved ones' end-of-life health care wishes. Method: Older patients visiting a medical clinic stated their preferences toward end-of-life health care in different health contexts, and surrogate decision makers independently predicted those preferences. For comparison purposes, surrogates also predicted patients' perceptions of everyday living conditions so that surrogates' accuracy of their loved ones' perceptions in nonstressful situations could be assessed. Results: Surrogates high on either type of insecure attachment dimension were less accurate in predicting their loved ones' end-of-life health care wishes. It is interesting to note that even though surrogates' attachment-related anxiety was associated with lower accuracy of end-of-life health care wishes of their loved ones, it was associated with higher accuracy in the nonstressful task of predicting their loved ones' everyday living conditions. Conclusions: Attachment orientation plays an important role in accuracy about loved ones' end-of-life health care wishes. Interventions may target emotion regulation strategies associated with insecure attachment orientations
The Casimir Force in Randall Sundrum Models
We discuss and compare the effects of one extra dimension in the Randall
Sundrum models on the evaluation of the Casimir force between two parallel
plates. We impose the condition that the result reproduce the experimental
measurements within the known uncertainties in the force and the plate
separation, and get an upper bound kR < 20 if the curvature parameter k of
AdS_5 is equal to the Planck scale. Although the upper bound decreases as k
decreases, kR ~ 12, which is the required value for solving the hierarchy
problem, is consistent with the Casimir force measurements. For the case where
the 5th dimension is infinite, the correction to the Casimir force is very
small and negligible.Comment: 16 pages, 2 figures, references added, text improved, accepted for
publication in PR
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