3,348 research outputs found
A New Model of Quintessence Compact Stars in Rastall Theory of Gravity
In the present work, we study a new model of anisotropic compact stars in the
regime of Rastall theory. To solve the Rastall field equations we have used the
Karori and Barua (KB) ansatz along with the quintessence dark energy
characterized by a parameter with . We
present a comparative study to demonstrate the physical acceptance of our
proposed model. We compare the numerical values of physical parameters obtained
from our model with those of general relativity () model given by Bhar
\cite{1} and observe that our model is more compatible (for some chosen values
of Rastall dimensionless parameter ) with observational
data than model. For this analysis we have consider four different compact
stars, , , and
with radii , , and , respectively. In this
investigation we also present some physical aspects of the proposed model
necessary to check the validity of the model and inferred that our model is
acceptable physically and geometrically.Comment: 20 pages, 16 figures, 8 tables, Accepted for Publication in Eur.
Physical Journal
Mass transfer efficiency of a tall and low plate free area liquid pulsed sieve-plate extraction column
Acknowledgements The authors would like to acknowledge Chakwal group of industries for funding the project. Ms. Madiha, Ms. Zona, Mr. Sohaib, Mr. Abdullah, Mr. Mudassar, and Mr. Salahuddin also deserve our acknowledgements for their assistance in different ways.Peer reviewedPublisher PD
Measuring the BDARX architecture by agent oriented system a case study
Distributed systems are progressively designed as multi-agent systems that are helpful in designing high strength complex industrial software. Recently, distributed systems cooperative applications are openly access, dynamic and large scales. Nowadays, it hardly seems necessary to emphasis on the potential of decentralized software solutions. This is because the main benefit lies in the distributed nature of information, resources and action. On the other hand, the progression in multi agent systems creates new challenges to the traditional methodologies of fault-tolerance that typically relies on centralized and offline solution. Research on multi-agent systems had gained attention for designing software that operates in distributed and open environments, such as the Internet. DARX (Dynamic Agent Replication eXtension) is one of the architecture which aimed at building reliable software that would prove to be both flexible and scalable and also aimed to provide adaptive fault tolerance by using dynamic replication methodologies. Therefore, the enhancement of DARX known as BDARX can provide dynamic solution of byzantine faults for the agent based systems that embedded DARX. The BDARX architecture improves the fault tolerance ability of multi-agent systems in long run and strengthens the software to be more robust against such arbitrary faults. The BDARX provide the solution for the Byzantine fault tolerance in DARX by making replicas on the both sides of communication agents by using BFT protocol for agent systems instead of making replicas only on server end and assuming client as failure free. This paper shows that the dynamic behaviour of agents avoid us from making discrimination between server and client replicas
Nonlinear analysis of drainage systems to examine surface deformation: an example from Potwar Plateau (Northern Pakistan)
We devise a procedure in order to characterize the relative vulnerability of the Earth's surface to tectonic deformation using the geometrical characteristics of drainage systems. The present study focuses on the nonlinear analysis of drainage networks extracted from Digital Elevation Models in order to localize areas strongly influenced by tectonics. We test this approach on the Potwar Plateau in northern Pakistan. This area is regularly affected by damaging earthquakes. Conventional studies cannot pinpoint the zones at risk, as the whole region is characterized by a sparse and diffuse seismicity. Our approach is based on the fact that rivers tend to linearize under tectonic forcing. Thus, the low fractal dimensions of the Swan, Indus and Jehlum Rivers are attributed to neotectonic activity. A detailed textural analysis is carried out to investigate the linearization, heterogeneity and connectivity of the drainage patterns. These textural aspects are quantified using the fractal dimension, as well as lacunarity and succolarity analysis. These three methods are complimentary in nature, i.e. objects with similar fractal dimensions can be distinguished further with lacunarity and/or succolarity analysis. We generate maps of fractal dimensions, lacunarity and succolarity values using a sliding window of 2.5 arc minutes by 2.5 arc minutes (2.5'×2.5'). These maps are then interpreted in terms of land surface vulnerability to tectonics. This approach allowed us to localize several zones where the drainage system is highly structurally controlled on the Potwar Plateau. The region located between Muree and Muzaffarabad is found to be prone to destructive events whereas the area westward from the Indus seems relatively unaffected. We conclude that a nonlinear analysis of the drainage system is an efficient additional tool to locate areas likely to be affected by massive destructing events affecting the Earth's surface and therefore threaten human activities
The Detector Control Systems for the CMS Resistive Plate Chamber
The Resistive Plate Chamber system is composed by 912 double-gap chambers equipped with about front-end boards. The correct and safe operation of the RPC system requires a sophisticated and complex online Detector Control System, able to monitor and control 2 hardware devices distributed on an area of about 5000 m. The RPC DCS acquires, monitors and stores about parameters coming from the detector, the electronics, the power system, the gas, and cooling systems. The DCS system and the first results, obtained during the 2007 and 2008 CMS cosmic runs, will be described in this paper
Silicon-mediated mitigation of wounding stress acts by up-regulating the rice antioxidant system
Silicon (Si) is essential for normal growth and development in plants and is also beneficial for their responses to wounding. However, the mechanisms by which Si acts to mitigate the effects of wounding is not fully understood. This effect possibly occurs through a reduction in the oxidative stresses associated with wounding. Here, we tested this possibility by investigating the effects of applying different concentrations of Si (0,5 and 1,0 mM) to rice plants under wounding stress for a period of 6 and 12 h. We found that a higher uptake of Si was signifiacntly associated with an increase in leaf chlorophyll contet. In response to wounding induced oxidative stress, the extent of lipid bilayer peroxidation was reduced in a dose-dependent manner by Si application for 6 or 12 h. Activity of the catalase enzyme was initially lowered by Si treatment; however, at 1.0 mM Si, catalase activity increased significantly after 12h of wounding stress. A similar response was also observed for a peroxidase enzyme. Polyphenol oxidase showed a significant reduction in activity. We conclude that Si application does not only improve leaf chlorophyll content but can also overcome the oxidative stress due wounds or physical injuries
Building-Related Symptoms, Energy, and Thermal Control in the Workplace: Personal and Open Plan Offices
This study compared building-related symptoms in personal and open plan offices, where high and low levels of control over the thermal environment were provided, respectively. The individualized approach in Norway provided every user with a personal office, where they had control over an openable window, door, blinds, and thermostat. In contrast, the open plan case studies in the United Kingdom provided control over openable windows and blinds only for limited occupants seated around the perimeter of the building, with users seated away from the windows having no means of environmental control. Air conditioning was deployed in the Norwegian case study buildings, while displacement ventilation and natural ventilation were utilized in the British examples. Field studies of thermal comfort were applied with questionnaires, environmental measurements, and interviews. Users’ health was better in the Norwegian model (28%), while the British model was much more energy efficient (up to 10 times). The follow-up interviews confirmed the effect of lack of thermal control on users’ health. A balanced appraisal was made of energy performance and users’ health between the two buildings
A limited survey of aflatoxins and zearalenone in feed and feed ingredients from Pakistan
This work presents current information on the presence of aflatoxins (AFs) and zearalenone (ZEN) in feed and feed ingredients from Punjab, Pakistan. The 105 samples tested were concentrated feed, i.e., cotton seed meal (18 samples) and soybean meal (14), and feed ingredients, i.e., crushed corn (17), crushed wheat (15), barley (17). and poultry feed (24). Samples were analyzed using high-performance liquid chromatography equipped with a fluorescence detector. Analysis revealed that 69 of 105 samples were contaminated with AFs, and the highest mean concentrations of AFB1 (6.20 μg/kg) and total AFs (9.30 μg/kg) were found in poultry feed samples. The mean total AF concentrations ranged from the limit of quantification to 165.5 μg/kg. However, 75 of the 105 samples were positive for ZEN. The highest mean concentration (19.45 μg/kg) was found in poultry feed samples. The mean ZEN concentrations were 0.15 to 145.30 μg/kg. The prevalence of AFs and ZEN was high in feed and feed ingredients and needs urgent attention
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