3,999 research outputs found
Dynamics of top-down factors with relation to ecological attributes of an endangered species Commiphora wightii
Present study was aimed to explore the influence of top down factors on ecological attributes of Commiphora wightii collected from seven districts of arid and semi arid parts of the Rajasthan. Ecological variables in respect of 46 accessions of this species were quantified. To assess the explanatory factors governing quantified ecological variables, soil samples were collected to analyze soil texture, soil EC, pH, available potassium, available phosphorus and total soil nitrogen. Results showed that there was a specific relationship between soil variables and occurence of C. wightii. The mid ranges of potassium (200-300 kg/ha) emerged as favourable to have better density and health of C. wightii: This is the first report on regulatory role of potassium on distribution and occurrence of C. wightii
Processing and characterization of polystyrene nanocomposites based on CoAl layered double hydroxide
AbstractThe present work deals with the development of polystyrene (PS) nanocomposites through solvent blending technique with diverse contents of modified CoAl layered double hydroxide (LDH). The prepared PS as well as PS/CoAl LDH (1–7 wt.%) nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), rheological analysis, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The XRD results suggested the formation of exfoliated structure, while TEM images clearly indicated the intercalated morphology of PS nanocomposites at higher loading. The presence of various functional groups in the CoAl LDH and PS/CoAl LDH nanocomposites was verified by FTIR analysis. TGA data confirmed that the thermal stability of PS composites was enhanced significantly as compared to pristine PS. While considering 15% weight loss as a reference point, it was found that the thermal degradation (Td) temperature increased up to 28.5 °C for PS nanocomposites prepared with 7 wt.% CoAl LDH loading over pristine PS. All the nanocomposite samples displayed superior glass transition temperature (Tg), in which PS nanocomposites containing 7 wt.% LDH showed about 5.5 °C higher Tg over pristine PS. In addition, the kinetics for thermal degradation of the composites was studied using Coats-Redfern method. The Criado method was ultimately used to evaluate the decomposition reaction mechanism of the nanocomposites. The complex viscosity and rheological muduli of nanocomposites were found to be higher than that of pristine PS when the frequency increased from 0.01 to 100 s−1
An Analysis of Farmers’ Perception and Awareness towards Crop Insurance as a Tool for Risk Management in Tamil Nadu
To insulate farmers against risks in agriculture, government has launched several schemes such as National Agricultural Insurance Scheme and weather index based crop insurance schemes. But their coverage seems to be limited among the farmers primarily due to lack of full information. This paper has reported the results of a survey of 600 farmers conducted to assess their perception about various facets of crop insurance schemes. The Probit and Tobit models have been employed to analyse the factors affecting awareness among the farmers. Crop diversification index has also been used to examine the farmers’ adjustment mechanism against risks. The survey has revealed that most farmers (65%) are aware of risk mitigation measures of the government. But, only half of the farmers have been found aware about the crop insurance schemes/products. This implies that there is need to disseminate information about insurance schemes across the target groups. Further, it has been shown that factors such as gross cropped area, income from other than agricultural sources, presence of risk in farming, number of workers in the farm family, satisfaction with the premium rate and affordability of the insurance premium amount significantly and positively influence the adoption of insurance and premium paid by the farmers. The study has clearly brought out the urgency of developing more innovative products, having minimum human interventions.Crop insurance, Risk management, Crop diversification index, Agricultural and Food Policy, Q14, Q18,
ROLE BASED SECURED ACCESS OF DATA IN CLOUDS
In mobile wireless sensor network, coverage and energyCloud computing is a type of internet-based computing that provides shared computer processing resources and data to computers and other devices on demand. It is a model for enabling ubiquitous, on-demand access to a shared pool of configurable computing resources e.g., computer networks, servers, storage, applications and services, which can be rapidly provisioned and released with minimal management effort. Attribute-based access control defines an access control paradigm whereby access rights are granted to users through the use of policies which combine attributes together. The policies can use any type of attributes such as user attributes, resource attributes, object and environment attributes etc. This model supports Boolean logic, in which rules contain "if-then" statements about who is making the request, the resource and the action. The main problem in attribute–based access control is not having user-centric approach for authorization rules. In ABAC model role hierarchy and object hierarchy is not achieved and restriction in level of expressiveness in access control rules.Secured role-based access control allows managing authorization based on rule-based approach where rules are under the control of data owner and provides enriched role-based expressiveness including role and object hierarchies. Data user without the knowledge of data owner cannot use the cloud server where privilege is provided to data user by data owner. Access control computations are delegated to the cloud service provider, being this not only unable to access the data, but also unable to release it to unauthorized parties. A identity-based proxy re-encryption scheme has been used in order to provide a comprehensive and feasible solution for data centric-approach. Semantic web technologies have been exposed for the representation and evaluation of the authorization model
- …