Performance of Recalibrated Equations for the Estimation of Daily Reference Evapotranspiration

An accurate estimation of reference evapotranspiration (ET₀) is of paramount importance for many studies such as hydrologic water balance, irrigation system design and management, crop yield simulation, and water resources planning and management. In the present study, Blaney-Criddle, Jensen-Haise and Hargreaves (temperature based), Priestley-Taylor, Radiation and Makkink (radiation based) and, Pan Evaporation and Christiansen (pan evaporation based) methods have been evaluated and recalibrated with respect to FAO-56 Penman-Monteith method for estimating daily ET₀ in the semi-arid Tirupati, Nellore, Rajahmundry, Anakapalli and Rajendranagar sites of Andhra Pradesh, India. Recalibrated Blaney-Criddle (temperature based), Radiation (Radiation based) and Christiansen (Pan evaporation based) methods showed a satisfactory performance at the sites. Further, recalibrated Blaney- Criddle method showed relatively better performance than Radiation and Christiansen methods in the daily ET₀ estimation. Recalibrated Blaney- Criddle method may therefore be adopted at the sites selected for the present study and also at the sites with similar climatic conditions for satisfactory daily ET₀ estimation.     

Basin Scale Water Resources Systems Modeling Under Cascading Uncertainties

Global change in climate and consequent large impacts on regional hydrologic systems have, in recent years, motivated significant research efforts in water resources modeling under climate change. In an integrated future hydrologic scenario, it is likely that water availability and demands will change significantly due to modifications in hydro-climatic variables such as rainfall, reservoir inflows, temperature, net radiation, wind speed and humidity. An integrated regional water resources management model should capture the likely impacts of climate change on water demands and water availability along with uncertainties associated with climate change impacts and with management goals and objectives under non-stationary conditions. Uncertainties in an integrated regional water resources management model, accumulating from various stages of decision making include climate model and scenario uncertainty in the hydro-climatic impact assessment, uncertainty due to conflicting interests of the water users and uncertainty due to inherent variability of the reservoir inflows. This paper presents an integrated regional water resources management modeling approach considering uncertainties at various stages of decision making by an integration of a hydro-climatic variable projection model, a water demand quantification model, a water quantity management model and a water quality control model. Modeling tools of canonical correlation analysis, stochastic dynamic programming and fuzzy optimization are used in an integrated framework, in the approach presented here. The proposed modeling approach is demonstrated with the case study of the Bhadra Reservoir system in Karnataka, India.     

Location-based design for secure and efficient wireless sensor networks

This paper studies a novel location-based design for secure and efficient wireless sensor networks. With this scheme, the sensing area is divided into a number of location cells and a logical group consists of four location cells. A pairwise key is established for each pair of sensor nodes in a logical group based on grid-based bivariate t-degree polynomials. An efficient en-route data authentication method is proposed to limit data authentication within a small neighboring range. In addition, a greedy location-based secure and energy-efficient data aggregation approach is integrated with the design. It further utilizes data aggregation by setting up control groups, applying pattern codes, selecting and switching control head nodes dynamically and periodically. The analysis demonstrate that our design is resilient to node compromise and decrease storage and communication overhead when compared with non location-based designs.     

Electronic spectra of VO2+ in some tutton salts

Optical absorption spectra of VO²⁺ in ammonium magnesium sulphate hexahydrate, potassium magnesium sulphate hexahydrate and potassium zinc sulphate hexahydrate single crystals have been studied. The observed bands in all three crystals have been attributed to the VO²⁺ ion in C_4v symmetry. The octahedral and tetragonal field parameters and the molecular orbital coefficients have been evaluated.     

Monitoring of particulate pollution —an inexpensive technique

Air quality monitoring has become a very important task. Conventional methods for monitoring particulate matter are tedious and require considerable effort and manpower. This paper provides the results of investigations in developing an inexpensive technique to monitor air pollution due to particulate matter. Three plants (i) Pedilanthus tithymaloides, (ii) Pedilanthus varigatum and (iii) Nephrolepis exaltata are selected for the study.

From the investigations, it is found that the inexpensive technique is very useful in developiong and under developed countries. It is also established that certain types of plants are quite effective in arresting particulate matter.     

ServBGP: BGP-inspired autonomic service routing for multi-provider collaborative architectures in the cloud

In this paper we propose the design and implementation of ServBGP, a service routing protocol for managing service collaboration among cloud providers in cloud computing. ServBGP is based on the policy-driven design of the well-known BGP Internet routing protocol to support the different service interaction models currently employed in the cloud particularly the monolithic, composite, and broker-based service models. The main contribution of this work lies in devising a system that autonomously manages the different aspects of service interaction and collaboration among service providers from service discovery and advertisement to service consumption and revocation. The ServBGP routing decision engine is designed to operate by (1) processing cost-bidding service advertisement and revocation messages from the different cloud providers and (2) extracting objective and trustworthy feedback which is maintained by certified network entities and which consists of a set of reputation scores related to quality of service, security, and pricing. The BGP-inspired design choice allows the proposed system to “stand upon the shoulders of giants” by relying on a time-tested protocol that currently supports scalable inter-domain routing services among over 120,000 IPv4 prefixes in the Internet. Moreover, reusing the decision logic of the standard BGP protocol aids in reducing the development and operational costs, hence shortening the time to market, and utilizing a large set of BGP extensions, particularly, in the security domain, that have been incorporated into BGP since its inception in 1989. These qualities are of a chief importance in the cloud community today to ensure the efficient and secure service collaboration among cloud providers and to support the evolution, scalability, and economic feasibility of the overall cloud computing infrastructure. A proof of concept implementation of the ServBGP design is realized on the NetKit network emulation and virtualization platform using the standard BGPv4 protocol. Moreover, the devised ServBGP design is developed from the ground up and deployed in a real cloud computing environment using Amazon EC2, Microsoft Azure, and Google App Engine cloud platforms.     

Preparation of BiFeO3 films by wet chemical method and their characterization

Multiferoic materials (having coupled electric, magnetic and structural order parameters that result in simultaneous ferroelectricity, ferromagnetism, and ferroelasticity) present opportunities for potential application in information storage, the emerging field of spinotronics and sensors. The perovskite BiFeO₃ is ferroelectric [Curie temperature (T_c) ∼1103 K] and antiferromagnetic [Neél temperature (T_N) ∼643 K], exhibiting weak magnetism at room temperature. Conditions for synthesizing single BiFeO₃ phase are critical since the temperature stability range of the phase is very narrow. Moreover, it is also difficult to control oxygen stoichiometry in the sample.In this work the preparation of BiFeO₃ thin films by a specific wet chemical route is discussed. Respective influence of the precursors, thermal annealing condition, the substrate and, generally speaking, the preparation process of the films is presented.Results obtained by X-ray diffraction and spectroscopic elipsometer (SE) was used to characterize the obtained films.     

An investigation on the machinability of Al-SiC metal matrix composites using pcd inserts

The paper attempts to study the machinability issues of aluminium-silicon carbide (Al-SiC) metal matrix composites (MMC) in turning using different grades of poly crystalline diamond (PCD) inserts. Al-SiC composite containing 15%wt of SiC was used as work material for turning and PCD inserts of three different grades were used as cutting tools. Experiments were conducted at various cutting speeds, feeds and depth of cuts and parameters, such as surface roughness, specific power consumed, and material removal rate were measured. The worn surface of the insert was examined by scanning electron microscope (SEM). The surface finish observed was found to be much lower than the theoretical surface roughness. The influence of cut was examined for the different grades of PCD inserts. It was observed that the 1600 grade PCD inserts performed well from the surface finish and specific power consumption points of view closely followed by the 1500 grade.