2,916 research outputs found
Noninvasive Embedding of Single Co Atoms in Ge(111)2x1 Surfaces
We report on a combined scanning tunneling microscopy (STM) and density
functional theory (DFT) based investigation of Co atoms on Ge(111)2x1 surfaces.
When deposited on cold surfaces, individual Co atoms have a limited diffusivity
on the atomically flat areas and apparently reside on top of the upper
pi-bonded chain rows exclusively. Voltage-dependent STM imaging reveals a
highly anisotropic electronic perturbation of the Ge surface surrounding these
Co atoms and pronounced one-dimensional confinement along the pi-bonded chains.
DFT calculations reveal that the individual Co atoms are in fact embedded in
the Ge surface, where they occupy a quasi-stationary position within the big
7-member Ge ring in between the 3rd and 4th atomic Ge layer. The energy needed
for the Co atoms to overcome the potential barrier for penetration in the Ge
surface is provided by the kinetic energy resulting from the deposition
process. DFT calculations further demonstrate that the embedded Co atoms form
four covalent Co-Ge bonds, resulting in a Co4+ valence state and a 3d5
electronic configuration. Calculated STM images are in perfect agreement with
the experimental atomic resolution STM images for the broad range of applied
tunneling voltages.Comment: 19 pages, 15 figures, 3 table
Splee:A declarative information-based language for multiagent interaction protocols
The Blindingly Simple Protocol Language (BSPL) is a novel information-based approach for specifying interaction protocols that can be enacted by agents in a fully decentralized manner via asynchronous messaging. We introduce Splee, an extension of BSPL. The extensions fall into two broad categories: multicast and roles. In Splee, a role binding is information that is dynamically generated during protocol enactment, potentially as the content (payload) of communication between two agents. Multicast communication is the idea that a message is sent to a set of agents. The two categories of extensions are interconnected via novel features such as set roles (the idea that a role binding can be a set of agents) and subroles (the idea that agents playing a role must be a subset of agents playing another role). We give the formal semantics of Splee and give small model characterizations of the safety and liveness of Splee protocols. We also introduce the pragmatic idea of query attachments for messages. Query attachments take advantage of Splee's information-orientation, and can help restrict the information (parameter bindings) communicated in a message
Bioassay evaluation of toxicity reduction in common effluent treatment plant
This paper investigates the utility and validity of bioassay toxicity testing using Daphnia magna straus as test organism for monitoring the common effluent treatment plant (CETP) receiving both industrial as well as domestic effluent. The average daphnia toxicity (Gd) at inlet, after primary settling tank (PST), secondary settling tank (SST) and tertiary treatment unit were reported as Gd-16, Gd-12, Gd-4 and Gd-1 respectively. However, a cumulative percentage removal in toxicity after PST, SST and tertiary treatment units was observed as 25%, 75% and 100%, respectively, during entire study period. It showed that a complete removal in daphnia toxicity (Gd) i.e.100% had been achieved only after tertiary treatment unit involving Dual Media Filters followed by activated carbon filters. Further attempts have been made to establish the relationship between key wastewater constituents i.e. Chemical Oxygen Demand (COD) and Suspended Solids (SS) with respects to daphnia toxicity (Gd). It was observed that COD and SS show a statistically significant correlation (r2) with daphnia toxicity (Gd) i.e. 0.89 and 0.81, respectively. Thus COD and SS can serve as a regulatory tool in lieu of an explicit toxicity standard (to check and improve the operational status of wastewatertreatment plants in time)
An Evaluation of Communication Protocol Languages for Engineering Multiagent Systems
Communication protocols are central to engineering decentralized multiagent systems. Modern protocol languages are typically formal and address aspects of decentralization, such as asynchrony. However, modern languages differ in important ways in their basic abstractions and operational assumptions. This diversity makes a comparative evaluation of protocol languages a challenging task. We contribute a rich evaluation of diverse and modern protocol languages. Among the selected languages, Scribble is based on session types; Trace-C and Trace-F on trace expressions; HAPN on hierarchical state machines, and BSPL on information causality. Our contribution is four-fold. One, we contribute important criteria for evaluating protocol languages. Two, for each criterion, we compare the languages on the basis of whether they are able to specify elementary protocols that go to the heart of the criterion. Three, for each language, we map our findings to a canonical architecture style for multiagent systems, highlighting where the languages depart from the architecture. Four, we identify design principles for protocol languages as guidance for future research
Iodization status of common salt in districts of western Uttar Pradesh
Research Problem: What is the amount of iodine in common salt samples. Objective: To estimate theamountof iodine in common salt samples. Study Design: Population based cross - sectional study. Setting: Randomly selected six districts of western U.P. Sample: Two salt samples randomly collected from house holds of each block area of the district. Sample Size: 152 salt samples. Study Variables: Iodine content in salt samples. Statistical Analysis: By chi - square test. Result: Unsatisfactory level of iodine was found in 52% of the salt samples. Crystal salt samples were more poorly iodized (70.9%) than powder salt samples (41.2%). Recommendations: Strict enforcement of ban on the sale of non-iodised salt
Protocols over Things:A Decentralized Programming Model for the Internet of Things
Current programming models for developing Internet of Things (IoT) applications are logically centralized and ill-suited for most IoT applications. We contribute Protocols over Things, a decentralized programming model that represents an IoT application via a protocol between the parties involved and provides improved performance over network-level delivery guarantees
Distribution of fatty acids during germination of soybean seeds
Gas chromatographic determination of the fatty acids in the seeds of soybean (Glycine max) showed mainly linoleic, oleic and palmitic acids with linoleic acid being the major component. Changes in the distribution of fatty acids were measured during germination in the cotyledons and roots. A decrease in palmitic and oleic acids was observed in the cotyledons from 6 to 12 days, while linoleic acid increased during the same period. In roots also, the major fatty acid was linoleic acid, while palmitic and linolenic acids were higher in roots in comparison with the cotyledons. During the 3-12 days of germination period, no major changes in the distribution pattern of fatty acids were observed in the roots. The possible significance of these changes is discussed
Hypergraphic LP Relaxations for Steiner Trees
We investigate hypergraphic LP relaxations for the Steiner tree problem,
primarily the partition LP relaxation introduced by Koenemann et al. [Math.
Programming, 2009]. Specifically, we are interested in proving upper bounds on
the integrality gap of this LP, and studying its relation to other linear
relaxations. Our results are the following. Structural results: We extend the
technique of uncrossing, usually applied to families of sets, to families of
partitions. As a consequence we show that any basic feasible solution to the
partition LP formulation has sparse support. Although the number of variables
could be exponential, the number of positive variables is at most the number of
terminals. Relations with other relaxations: We show the equivalence of the
partition LP relaxation with other known hypergraphic relaxations. We also show
that these hypergraphic relaxations are equivalent to the well studied
bidirected cut relaxation, if the instance is quasibipartite. Integrality gap
upper bounds: We show an upper bound of sqrt(3) ~ 1.729 on the integrality gap
of these hypergraph relaxations in general graphs. In the special case of
uniformly quasibipartite instances, we show an improved upper bound of 73/60 ~
1.216. By our equivalence theorem, the latter result implies an improved upper
bound for the bidirected cut relaxation as well.Comment: Revised full version; a shorter version will appear at IPCO 2010
Double intra venous cannula versus single needle technique of aspiration and methylprednisolone injection in the treatment of wrist ganglion: a comparative study
Background: Ganglion is the one of the common soft tissue swellings in the hand and wrist. Treatment options available include reassurance, nonsurgical means like aspiration with or without steroid or hyaluronidase injection and surgical or arthroscopic excision. All current treatment options produce suboptimal results. This study endeavours to compare the outcome and recurrence rate and other complications after treatment of wrist ganglion by aspiration and methylprednisolone injection by double Intravenous cannula versus single needle technique.Methods: A prospective comparative clinical study was done with a total of 72 patients. 36 patients in group 1 were treated with double intravenous cannula technique and 36 patients in group 2 were treated with single needle technique. All the patients were followed up for 6 months to look for recurrence and any complication. The patient’s age, sex and various characteristics of the ganglion cyst like side, site, size, etc. were recorded.Results: In group 1, recurrence was seen in 6 patients (15.7%) while in group 2, recurrence were seen in 14 (38.8%) patients. There was statistical significant difference between the two groups with p value of 0.04. No complication was seen in both groups due to methylprednisolone injection.Conclusions: Inspired by the results we advise to use aspiration and methylprednisolone injection by double intravenous cannula technique in the treatment of wrist ganglion before any surgical intervention. It is safe, simple, cost effective method and is less invasive and less time consuming with recurrence rate comparable to surgical and arthroscopic interventions
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Optimising Well-Being and Learning Through Participatory Processes and Practices::an International Comparative Analysis of Ten Groundwork Case-Studies in Schools
The paper presents a theory of participation in systems of learning that emerges from our evidence gathered through partnerships between schools and the academy. The theory identifies young people need to endorse common principles of participation to include and respect all. Educational leaders’ evidence informed intervention strategies can positively impact young people’s inclusive and respectful participation in the action-research. The theory of participation conceptualises young people’s need for opportunities to pursue their ambitions and interests. Leaders’ intervention strategies may develop young people’s participation in attaining target examination outcomes to achieve their ambitions. We then develop the theory of participation regarding young people pursuing independent interests and ambitions in association with the other, to enable them to be drivers of social change. To do this they need to understand their future identity as potential consumers, employees, employers, and entrepreneurs with Small and Medium Enterprises (SME) that challenge public corporations in a variety of ways. We theorise how young people are well situated to build capacity in Europe and globally using the social media networks they have already developed. Our evidence identified five participation principals of inclusion, respect, trust in the search for truth, constructive cross-cultural critique of alternative world views to arrive at a shared multicultural world view, and the generation of new knowledge to enable the re-imagining of new futures where young people are drivers of social change. From these principals we developed a theory of practice and four global standards as guidelines. First, a commitment to inclusionary partnerships and communities of practice. Second, distributed autonomy across stakeholders in the institution characterized by respect for individuals’ associated rights and responsibilities. Third, constructive cross-cultural criticism underpinned by trust in a search for truth, using different group’s constructed identity schema’s to develop a shared multicultural world view. Fourth, the generation of new knowledge through structures and mechanisms to optimize participation
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