688 research outputs found

    Growing Surface Tension of Amorphous-Amorphous Interfaces on Approaching the Colloidal Glass Transition

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    There is mounting evidence indicating that relaxation dynamics in liquids approaching their glass transition not only becomes increasingly cooperative (1,2) but the relaxing regions also become more compact in shape(3-7). While the surface tension of the interface separating neighboring relaxing regions is thought to play a crucial role in deciding both their size and morphology(8-10), owing to the amorphous nature of these regions, even identifying these interfaces has not been possible in bulk liquids. Here, by devising a scheme to identify self-induced disorder sites in bulk colloidal liquids, we directly quantified the dynamics of interfaces delineating regions of high and low configurational overlap. This procedure also helped unveil a non-monotonicity in dynamical correlations that has never been observed in bulk supercooled liquids. Using the capillary fluctuation method (11,12), we measured the surface tension of amorphous-amorphous interfaces with supercooling and find that it increases rapidly across the mode-coupling area fraction. Remarkably, a similar growth in the surface tension is also seen in the presence of a pinned amorphous wall. Our observations help prune theories of glass formation and opens up new research avenues aimed at tuning the properties of amorphous-amorphous interfaces, and hence the glass itself, in a manner analogous to grain boundary engineering in polycrystals (13)

    Analysis Of Single Server Queueing System With Batch Service Under Multiple Vacations With Loss And Feedback

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    Consider a single server queueing system with foxed batch service under multiple vacations with loss and feedback in which the arrival rate ? follows a Poisson process and the service time follows an exponential distribution with parameter ?. Assume that the system initially contain k customers when the server enters the system and starts the service in batch. The concept of feedback is incorporated in this model (i.e) after completion of the service, if this batch of customers dissatisfied then this batch may join the queue with probability q and with probability (1-q) leaves the system. This q is called a feedback probability. After completion of the service if he finds more than k customers in the queue then the first k customers will be taken for service and service will be given as a batch of size k and if he finds less than k customers in the queue then he leaves for a multiple vacation of exponential length ?. The impatient behaviour of customer is also studied in this model (i.e) the arriving customer may join the queue with probability p when the server is busy or in vacation. This probability p is called loss probability. This model is completely solved by constructing the generating function and Rouche’s theorem is applied and we have derived the closed form solutions for probability of number of customers in the queue during the server busy and in vacation. Further we are providing the analytical solution for mean number of customers and variance of the system. Numerical studies have been done for analysis of mean and variance for various values of ?, µ, ?, p, q and k and also various particular cases of this model have been discussed. Keywords : Single Server , Batch Service, Loss and Feedback,  Multiple vacations, Steady state distribution

    Head in the Clouds-Floating Locomotion in Virtual Reality

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    Navigating large virtual spaces within the confines of a small tracked volume in a seated position becomes a serious accessibility issue when users' lower seating position reduces their visibility and makes it uncomfortable to reach for items with ease. Hence, we propose a 'floating' accessibility technique, in which a seated VR user experiences the virtual environment from the perspective of a standing eye height. We conducted a user study comparing sitting, standing and floating conditions and observed that the floating technique had no detrimental effect in comparison to the standing technique and had a slight benefit over the sitting technique

    Predicting clinically signficant change in an inpatient program for people with severe mental illness

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    Objective: The first aim of this study was to assess the proportion of patients who achieved reliable and clinically significant change over the course of treatment in an inpatient psychosocial rehabilitation program. The second aim was to determine whether age, gender, length of stay, and diagnosis and co-morbid diagnosis predicted those who were classified as improved or not improved, using clinical significance criteria. Method: Three hundred and thirty-seven patients from inpatient units at Bloomfield Hospital, Orange, New South Wales, Australia were assessed at admission, 3-month reviews and discharge using the expanded Brief Psychiatric Rating Scale, the Health of the Nation Outcome Scales and the Kessler 10. Results: Reliable and clinically significant improvement was found for 32.4% of inpatients on psychiatric symptomatology, 19.5% on psychosocial functioning and 20.2% on psychological distress. Logistic regression analyses found that the predictor variables collectively predicted those who made reliable and clinically significant improvement on psychiatric symptomatology, but not on psychosocial functioning or psychological distress. Those with a primary diagnosis of schizoaffective disorder had higher rates of improvement in psychiatric symptomatology compared to those with a diagnosis of schizophrenia. Those with co-morbid substance abuse disorders showed a trend towards greater improvement. Conclusions: Inpatient treatment is associated with clinically significant improvements for some patients with a severe mental illness. Patients with schizo-affective disorders are proportionally more likely to make improvement

    Soil bacterial communities of a calcium-supplemented and a reference watershed at the Hubbard Brook Experimental Forest (HBEF), New Hampshire, USA

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    Soil Ca depletion because of acidic deposition-related soil chemistry changes has led to the decline of forest productivity and carbon sequestration in the northeastern USA. In 1999, acidic watershed (WS) 1 at the Hubbard Brook Experimental Forest (HBEF), NH, USA was amended with Ca silicate to restore soil Ca pools. In 2006, soil samples were collected from the Ca-amended (WS1) and reference watershed (WS3) for comparison of bacterial community composition between the two watersheds. The sites were about 125 m apart and were known to have similar stream chemistry and tree populations before Ca amendment. Ca-amended soil had higher Ca and P, and lower Al and acidity as compared with the reference soils. Analysis of bacterial populations by PhyloChip revealed that the bacterial community structure in the Ca-amended and the reference soils was significantly different and that the differences were more pronounced in the mineral soils. Overall, the relative abundance of 300 taxa was significantly affected. Numbers of detectable taxa in families such as Acidobacteriaceae, Comamonadaceae, and Pseudomonadaceae were lower in the Ca-amended soils, while Flavobacteriaceae and Geobacteraceae were higher. The other functionally important groups, e.g. ammonia-oxidizing Nitrosomonadaceae, had lower numbers of taxa in the Ca-amended organic soil but higher in the mineral soil

    Analysis of Single Server Fixed Batch Service Queueing System under Multiple Vacation with Catastrophe

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    Consider a single server fixed batch service queueing system under multiple vacation with a possibility of catastrophe in which the arrival rate ? follows a Poisson process and the service time follows an exponential distribution with parameter ?. Further we assume that the catastrophe occur at the rate of ? which follows a Poisson process and the length of time the server in vacation follows an exponential distribution with parameter ?.  Assume that the system initially contains k customers when the server enters in to the system and starts the service immediately in a batch of size k. After completion of a service, if he finds less than k customers in the queue, then the server goes for a multiple vacation of length ?. If there are more than k customers in the queue then the first k customers will be selected from the queue and service will be given as a batch. We are analyzing the possibility of catastrophe that is whenever a catastrophe occurs in the system, all the customers who are in the system will be completely destroyed and system becomes an empty and server goes for a multiple vacation. This model is completely solved by constructing the generating function  and we have derived the closed form solutions for probability of number of customers in the queue during the server busy and in vacation. Further we are providing the analytical solution for mean number of customers and variance of the system. Numerical studies have been done for analysis of mean and variance of number of customers in the system for various values of ?, µ, ? and k and also various particular cases of this model have been discussed. Keywords: Single server queue , Fixed batch service , Catastrophe, Multiple vacation, Steady state distributio

    Groundwater quality assessment by Water quality index (WQI) and Multivariate statistical analysis (MSA) for coastal zones of Srikakulam district, Andhra Pradesh

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    Groundwater is a vital resource for the drinking water supply to the people in the areas residing in the coastal zones. Rapid industrialization increased the human population, and anthropogenic activities led to groundwater pollution. The water quality should be continuously monitored to analyse the suitability of the water, and it is only possible by the water quality index. In the current study, we attempted to determine the groundwater quality of the Mandal headquarters of the coastal zones of the Srikakulam district, Andhra Pradesh, by using the water quality index (WQi) considering the parameters pH, Electrical conductivity, Total Dissolved Solids, Total Hardness, calcium and magnesium, potassium, and sodium, human health assessment tool, and multivariate statistical analysis. The results found that the WQi of the coastal zones ranged from 49.6 to 361.7, and in the post-monsoon season, the Etcherla Mandal station water was not advisable for drinking. Human health risk assessment showed that children in these sampling stations are more prone to the non-carcinogenic health risks associated with nitrate pollution. Proper reduction measures in the sampling areas must be taken to depreciate nitrate and seepage into the groundwater. Piper plots and correlation matrices showed the anion-cation interaction, and the principal component analyzed and showed the pollution sources. The current study concluded that anthropogenic activities continuously deteriorate groundwater quality, indirect saltwater intrusion was identified, and groundwater treatment is necessary before consumption.

    Chemotherapy of malaria. VI. Quinolylsulphones

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    Twenty-one aryquinolylsulphones described in the table have been prepared by reacting the chloroquinolines with substituted arylsulphinic acids. The 4-chloroquinolines furnish the sulphones very readily and these sulphones are easily hydrolysed to the corresponding 4-hydroxyquinolines. These compounds do not show any activity when tested for their prophylactic activity in mosquitoes againstPlasmodium gallinaceum infection

    Chemotherapy of bacterial infections. XIII. Synthesis of unsymmetrical diphenylsulphones

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