Effect of high resistive barrier on earthing system

Substation earthing provides a low impedance path and carries current into ground under normal and fault conditions without adversely affecting continuity of service. Under a fault condition, the ground voltage may rise to a level that may endanger the public outside the vicinity of the substation. In such a case a high resistive barrier can be inserted around the vicinity of the substation to reduce the surface potentials immediately beyond the barrier. In this paper the effect of barrier on the overall performance of the earthing system has been investigated experimentally and computationally based on an earthing system consisted of combined grid and rods in a water tank. The effect of the position and depth of the barrier to the resistance of the earthing system and surface potentials in and around the substation have been examined

Modelling trust in semantic web applications

This paper examines some of the barriers to the adoption of car-sharing, termed carpooling in the US, and develops a framework for trusted recommendations. The framework is established on a semantic modelling approach putting forward its suitability to resolving adoption barriers while also highlighting the characteristics of trust that can be exploited. Identification is made of potential vocabularies, ontologies and public social networks which can be used as the basis for deriving direct and indirect trust values in an implementation

Semantic-driven matchmaking of web services using case-based reasoning

With the rapid proliferation of Web services as the medium of choice to securely publish application services beyond the firewall, the importance of accurate, yet flexible matchmaking of similar services gains importance both for the human user and for dynamic composition engines. In this paper, we present a novel approach that utilizes the case based reasoning methodology for modelling dynamic Web service discovery and matchmaking. Our framework considers Web services execution experiences in the decision making process and is highly adaptable to the service requester constraints. The framework also utilises OWL semantic descriptions extensively for implementing both the components of the CBR engine and the matchmaking profile of the Web services

Storyline description of Southern Hemisphere midlatitude circulation and precipitation response to greenhouse gas forcing

As evidence of climate change strengthens, knowledge of its regional implications becomes an urgent need for decision making. Current understanding of regional precipitation changes is substantially limited by our understanding of the atmospheric circulation response to climate change, which to a high degree remains uncertain. This uncertainty is reflected in the wide spread in atmospheric circulation changes projected in multimodel ensembles, which cannot be directly interpreted in a probabilistic sense. The uncertainty can instead be represented by studying a discrete set of physically plausible storylines of atmospheric circulation changes. By mining CMIP5 model output, here we take this broader perspective and develop storylines for Southern Hemisphere (SH) midlatitude circulation changes, conditioned on the degree of global-mean warming, based on the climate responses of two remote drivers: the enhanced warming of the tropical upper troposphere and the strengthening of the stratospheric polar vortex. For the three continental domains in the SH, we analyse the precipitation changes under each storyline. To allow comparison with previous studies, we also link both circulation and precipitation changes with those of the Southern Annular Mode. Our results show that the response to tropical warming leads to a strengthening of the midlatitude westerly winds, whilst the response to a delayed breakdown (for DJF) or strengthening (for JJA) of the stratospheric vortex leads to a poleward shift of the westerly winds and the storm tracks. However, the circulation response is not zonally symmetric and the regional precipitation storylines for South America, South Africa, South Australia and New Zealand exhibit quite specific dependencies on the two remote drivers, which are not well represented by changes in the Southern Annular Mode

Biochemical and Physiological Biomarkers in Aquatic Environmental Research

Biomarkers are used as tools to assess biological changes that may reveal exposure of organisms to environmental chemicals. In some cases, biomarkers are able to indicate that chemicals specifically affect metabolicpathways or physiological functions in exposed individuals. Therefore, biomarkers can be used as both diagnostic and predictive tools. More recently, the concept of “biomarkers” has gained popularity amongst environmental managers. There are many different biomarkers that occur at many different levels of organization from sub-cellular to wholeorganisms. Biomarkers at the molecular level tend to respond first, followed by responses at the cellular (biochemical and physiological), and whole-body levels. within this review, I will review the application of some biochemical and physiological biomarkers in aquatic environmental research. This review presents a synthesis of the state of the art in themethodology of biochemical and physiological biomarkers and its contribution in aquatic environmental research. The text explores the latest knowledge and thinking on this very important approach for the assessment of environmental health, management, and conservation. The primary concern of the present review is the measurement of biomarkers in aquatic organisms under field and laboratory conditions, where effects of chemicals at different levels of biological organization can be examined.Keywords: Biomarkers, aquatic organisms, biochemical biomarkers, physiological biomarker

Biochemical and Physiological Biomarkers in Aquatic Environmental Research

Biomarkers are used as tools to assess biological changes that may reveal exposure of organisms to environmental chemicals. In some cases, biomarkers are able to indicate that chemicals specifically affect metabolicpathways or physiological functions in exposed individuals. Therefore, biomarkers can be used as both diagnostic and predictive tools. More recently, the concept of “biomarkers” has gained popularity amongst environmental managers. There are many different biomarkers that occur at many different levels of organization from sub-cellular to wholeorganisms. Biomarkers at the molecular level tend to respond first, followed by responses at the cellular (biochemical and physiological), and whole-body levels. within this review, I will review the application of some biochemical and physiological biomarkers in aquatic environmental research. This review presents a synthesis of the state of the art in themethodology of biochemical and physiological biomarkers and its contribution in aquatic environmental research. The text explores the latest knowledge and thinking on this very important approach for the assessment of environmental health, management, and conservation. The primary concern of the present review is the measurement of biomarkers in aquatic organisms under field and laboratory conditions, where effects of chemicals at different levels of biological organization can be examined.Keywords: Biomarkers, aquatic organisms, biochemical biomarkers, physiological biomarker

Correlation functions of small-scale fluctuations of the interplanetary magnetic field

The Interplanetary Magnetic Field shows complex spatial and temporal variations. Single spacecraft measurements reveal only a one dimensional section of this rich four dimensional phenomenon. Multi-point measurements of the four Cluster spacecraft provide a unique tool to study the spatiotemporal structure of the field. Using Cluster data we determined three dimensional correlation functions of the fluctuations. By means of the correlation function one can describe and measure field variations. Our results can be used to verify theoretical predictions, to understand the formation and nature of solar wind turbulence. We found that the correlation length varies over almost six orders of magnitude. The IMF turbulence shows significant anisotropy with two distinct populations. In certain time intervals the ratio of the three axes of the correlation ellipse is 1/2.2/6 while in the remaining time we found extremely high correlation along one axis. We found favoured directions in the orientation of the correlation ellipsoids.Comment: accepted to Solar Physics on June 14, 2010. 10 pages, 8 figure

Quantifying the Impact of Replication on the Quality-of-Service in Cloud Databases

Cloud databases achieve high availability by automatically replicating data on multiple nodes. However, the overhead caused by the replication process can lead to an increase in the mean and variance of transaction response times, causing unforeseen impacts on the offered quality-of-service (QoS). In this paper, we propose a measurement-driven methodology to predict the impact of replication on Database-as-a-Service (DBaaS) environments. Our methodology uses operational data to parameterize a closed queueing network model of the database cluster together with a Markov model that abstracts the dynamic replication process. Experiments on Amazon RDS show that our methodology predicts response time mean and percentiles with errors of just 1% and 15% respectively, and under operational conditions that are significantly different from the ones used for model parameterization. We show that our modeling approach surpasses standard modeling methods and illustrate the applicability of our methodology for automated DBaaS provisioning

Sex distribution of offspring-parents obesity: Angel's hypothesis revisited

This study, which is based on two cross sectional surveys' data, aims to establish any effect of parental obesity sex distribution of offspring and to replicate the results that led to the hypothesis that obesity may be associated with sex-linked recessive lethal gene. A representative sample of 4,064 couples living in Renfrew/Paisley, Scotland was surveyed 1972-1976. A total of 2,338 offspring from 1,477 of the couples screened in 1972-1976, living in Paisley, were surveyed in 1996. In this study, males represented 47.7% among the total offspring of the couples screened in 1972-1976. In the first survey there was a higher male proportion of offspring (53%, p < 0.05) from parents who were both obese, yet this was not significant after adjustment for age of parents. Also, there were no other significant differences in sex distribution of offspring according to body mass index, age, or social class of parents. The conditions of the original 1949 study of Angel (1949) (which proposed a sex-linked lethal recessive gene) were simulated by selecting couples with at least one obese daughter. In this subset, (n = 409), obesity in fathers and mothers was associated with 26% of offspring being male compared with 19% of offspring from a non-obese father and obese mother. Finally we conclude that families with an obese father have a higher proportion of male offspring. These results do not support the long-established hypotheses of a sex-linked recessive lethal gene in the etiology of obesity