Relating Trends in Streamflow to Anthropogenic Influences: A Case Study of Himayat Sagar Catchment,India

Catchment development has been identified as a potentially major cause of streamflow change in many river basins in India. This research aims to understand changes in the Himayat Sagar catchment (HSC), India, where significant reductions in streamflow have been observed. Rainfall and streamflow trend analysis for 1980–2004 shows a decline in streamflow without significant changes in rainfall. A regression model was used to quantify changes in the rainfall-runoff relationship over the study period. We relate these streamflow trends to anthropogenic changes in land use, groundwater abstraction and watershed development that lead to increased ET (Evapotranspiration) in the catchment. Streamflow has declined at a rate of 3.6 mm/y. Various estimates of changes in evapotranspiration/irrigation water use were made. Well inventories suggested an increase of 7.2 mm/y in groundwater extractions whereas typical irrigation practices suggests applied water increased by 9.0 mm/y, while estimates of evapotranspiration using remote sensing data showed an increasing rate of 4.1 mm/y. Surface water storage capacity of various small watershed development structures increased by 2 mm over 7 years. It is concluded that the dominant hydrological process responsible for streamflow reduction is the increase in evapotranspiration associated with irrigation development, however, most of the anthropogenic changes examined are interrelated and occurred simultaneously, making separating out individual impacts very difficult.     

Numerical Investigation on Natural Convection Inside the Side Ventilated Square Enclosure with Vertical Mid-Partition

A finite volume-based computational study of steady laminar natural convection inside the square enclosure with cold partition wall centrally placed on top and bottom is presented. The fluid considered is air with Prandtl number 0.71. Except the partition walls, all other walls were assumed as hot. The heights of inlet and outlet ports are constantly fixed as 20% of height of the enclosure. The height of the opening in the partition walls were 10%, 20%, and 30% of height of enclosure. The buoyancy-driven heat transfer mechanism inside the domain is influenced by the percentage of opening in the partition, Rayleigh number, and geometrical position of inlet and outlet. The cold partition walls attract the flow that subsequently influences the thermal modifications around the partition. The fluid flow and heat transfer were investigated for 81 cases with different positions of inlet and outlet and varying height of openings for Ra = 10³, 10⁴, and 10⁵. The cross flow between the vertical walls through the opening in the central partition wall was considered in this study. The formation of vortices and their sizes depends on the configuration of inlet and outlet ports. The higher temperature gradient occurs near the inlet and outlet port of vertical walls. Local Nusselt number is maximum just below the inlet for all cases. Due to the dominance of buoyancy forces, heat transfer rate increases when Rayleigh number increases for all the cases. The hydrodynamic block effect by the openings on the partition wall has significant effect on the velocity profile than on the heat transfer.     

Extraction of cardanol and phenol from bio-oils obtained through vacuum pyrolysis of biomass using supercritical fluid extraction

The feasibility of extraction of phenol rich oil from the bio-oils obtained through pyrolysis of cashew nut shells and sugarcane bagasse is studied. The extraction rate of phenol rich oil using CO₂ as a supercritical fluid is discussed. Operating parameters are optimized for the maximum concentration of phenol and cardanol. Higher yield of oil (50% by weight) along with higher concentration of phenols and cardanol by present method is found encouraging. The experiments were conducted in the pressure range of 120-300 bar, the temperature range of 303-333 K and the mass flow rate range of 0.7-1.2 kg/h. The process parameters are optimized to maximize the yield of extracts and its contents of phenols and substituted phenols from sugarcane bagasse pyrolysis oil. The oil samples obtained at various operating parameters are analyzed by Gas Chromatograph-Mass Spectroscopy (GC-MS) and Fourier Transform Infra-Red Spectroscopy (FTIR).     

Studies on porous radiant burners for LPG (liquefied petroleum gas) cooking applications

This paper deals with the performance tests of a PRB (porous radiant burner) used for LPG (liquefied petroleum gas) domestic cooking stoves. The burner consists of a two-layer porous media. The combustion zone is made up of silicon carbide, and alumina balls forms the preheating zone. For a given burner diameter, the performances of the burner, in terms of thermal efficiency and emission characteristics, are analysed for different equivalence ratios and thermal loads (wattages). The water boiling test as prescribed in the BIS (Bureau of Indian Standard): 4246:2002 was used to calculate the thermal efficiency of both the conventional LPG cooking stoves and the PRB. The maximum thermal efficiency of the LPG cooking stoves with a PRB was found to be 68% which is 3% higher than that of the maximum thermal efficiency of the conventional domestic LPG cooking stoves. Unlike the conventional LPG stoves, for which the CO and NO_X emissions were found in the ranges 400–1050 mg/m³ and 162–216 mg/m³, respectively, for the one with PRB, the same were in the ranges of 25–350 mg/m³ and 12–25 mg/m³. The axial temperature distribution in the burner showed that the reaction zone was close to the interface of the two zones and at a higher thermal load, it shifted towards the downstream. The surface temperature of the PRB was found to be uniform.     

Ferrofluid lubrication in porous inclined slider bearing with velocity slip

The effects of slip velocity and the material constant in a porous inclined slider bearing lubricated with a ferrofluid were theoretically studied by using Jenkins model. Expressions were obtained for pressure, load capacity, friction on the slider, coefficient of friction and position of the centre of pressure. The increase in slip parameter caused decrease in load capacity as well as friction and increase in the coefficient of friction without altering the centre of pressure much. As the material constant increased, the load capacity decreased, friction and coefficient of friction increased and the position of the centre of pressure shifted slightly towards the inlet of the bearing.     

Fuzzy Logic Based Multi-criteria Intelligent Forward Routing in VANET

Wireless Personal Communications - Vehicular ad-hoc network have the capability for enhancing the road safety using intelligent transportation system by communicating with each other (V–V) as...     

Design of a Guitar Shaped UWB Antenna with Wide Band Notched Characteristics for Wireless Applications

Cloud storage is a cloud based service which delivers scalable on demand on line storage of data and eliminates the need of maintaining local data centre. Storage of data in cloud brings many advantages such as lower-cost, metered service, scalable and ubiquitous access. However, it also raises concerns to its integrity; to save the storage space cloud service provider may delete some rarely access data. Data privacy is another issue which must be addressed to increase data owner’s trust. To address above issues, many researchers have proposed public auditing schemes to validate the integrity of data using third party auditor. These schemes generate metadata using data files on the owner side and store these metadata on the cloud storage along with the file data, which helps in auditing. These schemes address many concerns which arise due to remote data storage. However, computation cost involved for metadata generation at the data owner side is not properly addressed; another issue which is not properly addressed is an iniquitous third party auditor may be the source of denial of service attack by issuing constantly large number of audit request. Our scheme solves these issues by lowering the computation cost at data owner side and controlling the number of times a third party auditor can issue an audit request to the cloud storage. Our Scheme also supports secure access of data using conditional proxy re-encryption scheme and delegation of auditing task by the authorized third party auditor to another auditor for the specified period of times in the case of unavailability of authorized third party auditor.

     

适用于高密度、低功耗应用的新型存储器

为了满足用户对手机更多服务的需求,服务提供商不断推陈出新，促使仅具通话功能的传统手机向同时具有语音和数据功能的新型手机转换。向数据通信功能的转变将直接影响手机中的硬件结构。目前，2．5G和3G手机已经能够提供更多的功能，诸如SMS(短信息服务)、MMS(多媒体信息服务)、图象传送、音频／视频流和因特网接入等。     

Modified foreground segmentation for object tracking using wavelets in a tensor framework

Subspace-based techniques have become important in behaviour analysis, appearance modelling and tracking. Various vector and tensor subspace learning techniques are already known that perform their operations in offline as well as in an online manner. In this work, we have improved upon a tensor-based subspace learning by using fourth-order decomposition and wavelets so as to have an advanced adaptive algorithm for robust and efficient background modelling and tracking in coloured video sequences. The proposed algorithm known as fourth-order incremental tensor subspace learning algorithm uses the spatio-colour-temporal information by adaptive online update of the means and the eigen basis for each unfolding matrix using tensor decomposition to fourth-order image tensors. The proposed method employs the wavelet transformation to an optimum decomposition level in order to reduce the computational complexity by working on the approximate counterpart of the original scenes and also reduces noise in the given scene. Our tracking method is an unscented particle filter that utilises appearance knowledge and estimates the new state of the intended object. Various experiments have been performed to demonstrate the promising and convincing nature of the proposed method and the method works better than existing methods.     

Test Generation for Mixed-Signal Devices Using Signal Flow Graphs

We describe a new reverse simulation approach to analog and mixed-signal circuit test generation that parallels digital test generation. We invert the analog circuit signal flow graph, reverse simulate it with good and bad machine outputs, and obtain test waveforms and component tolerances, given circuit output tolerances specified by the functional test needs of the designer. The inverted graph allows backtracing to justify analog outputs with analog input sinusoids. Mixed-signal circuits can be tested using this approach, and we present test generation results for two mixed-signal circuits and four analog circuits, one being a multiple-input, multiple-output circuit. This analog backtrace method can generate tests for second-order analog circuits and certain non-linear circuits. These cannot be handled by existing methods, which lack a fault model and a backtrace method. Our proposed method also defines the necessary tolerances on circuit structural components, in order to keep the output circuit signal within the envelope specified by the designer. This avoids the problem of overspecifying analog circuit component tolerances, and reduces cost. We prove that our parametric fault tests also detect all catastrophic faults. Unlike prior methods, ours is a structural, rather than functional, analog test generation method.