1,017 research outputs found

    A Survey of Growth and Development Issues of the Pacific Islands

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    This paper is a survey of some key variables with an international dimension and implications for growth and development policies in selected Pacific island countries. Results from a simple growth accounting exercise show that factor accumulation is the most dominant growth factor and that the contribution of total factor productivity is negligible. Therefore, increasing the investment rate to improve growth rate is a pragmatic medium-term policy option. Further, econometric analysis shows that foreign aid has a negligible effect on output and growth in Fiji, Solomon Islands and Papua New Guinea.macroeconomic analyses, economic growth, development issues, Pacific islands

    Investigation of Heavy Metals in Crystalline Aquifer Groundwater from Different Valleys of Bangalore, Karnataka

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    Fifty-one groundwater samples were collected during South-west monsoon 2009 from Challaghatta, Vrishabhavathi, Kormangala and Hebbal valleys, Bangalore, which is an unconfined/crystalline aquifer to investigate Fe, Mn, Cu, Zn, Pb, Cd, Cr, Ni concentrations and other parameters like temperature, pH, electric conductivity (EC) and total dissolved solid (TDS). The TDS and EC variation confirmed light- salty nature of groundwater found to be contaminated by Salty water intrusion, which is attributed to over-extraction. Comparison between presence, abundance and frequencies of trace elements in groundwater samples is in the order of Fe (84) > Zn (72) > Mn (68) >Pb (45) >Cu (41) >Cr (35) >Ni (33) >Cd (21), indicating that Fe in groundwater is in origin. The TDS, Pb, Fe, Mn and Cd concentrations in groundwater samples are beyond the permissible limit prescribed by World Health Organization (WHO)

    Bacteriological assessment of groundwater in Arkavathi and Vrishabhavathi basins, Bangalore, Karnataka

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    In the newly developed and old parts of Bangalore city, municipal, domestic and industrial effluents are channelized into an open sewerage system. Most of the wells situated within 2 km radius of this open sewerage networks were found to be profoundly loaded with total and facal coliform. The average counts of total and facal coliform from the lake samples were 227 and 79 CFU/100 ml, 82 and 14 CFU/100 ml from the open wells and 63 and 34 CFU/100 ml from the bore wells respectively. The level of contamination is beyond the permissible limit for indicator organisms in groundwater during winter season, which can render the consumer more vulnerable to health risks

    An Independently Tunable Tri-band Antenna Design for Concurrent Multi-band Single Chain Radio Receivers

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    In this paper, a novel tunable tri-band antenna is presented for concurrent, multi-band, single chain radio receivers. The antenna is manufactured on a 50×100 mm FR4 printed circuit board (PCB), and is able to provide three concurrent, independently tunable operating bands covering a frequency range from 600 MHz to 2.7 GHz. The antenna performance is investigated for both numerical and experimental methods when using, first, varactor diodes and, second, digitally tunable capacitors (DTCs) to tune frequencies, which shows the antenna gain can be improved by up to 2.6 dBi by using DTCs. A hardware-in-the-loop test-bed provides a system level evaluation of the proposed antenna in a direct RF digitized, concurrent, tri-band radio receiver. By measuring the receiver’s error vector magnitude, we demonstrate sufficient isolation between concurrent bands achieving 30 MHz of aggregated bandwidth as well as strong resilience to adjacent blockers next to each band. The data reported in this article are available from the ORDA digital repository (https://doi.org/10.15131/shef.data.5346295)

    Environmental isotopes investigation in groundwater of Challaghatta valley, Bangalore: A case study

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    Radiogenic isotopes (3H and 14C) and stable isotope (18O) together with TDS, EC and salinity of water were used to discriminate qualitative and quantitative groundwater age, probable recharge time, flow respectively in groundwater of Challaghatta valley, Bangalore. The variations between TDS and EC values of sewage, corporation water, bore and open wells with concomitant variations in salinity confirmed an immerse relationship with the depth of wells, Also, the source of recharge and contamination of groundwater as sewage. However, lighter À18O bearing water more commonly occurred at higher elevations and heavier at lower elevations in the entire valley presenting a clear enrichment in À18O probably due to evaporation and confirming major source of surface water as South - West monsoon. The groundwater samples in valley contained higher 3H except five samples (OW21, OW24, BW5, BW20 and BW24), suggesting recent recharge and categorized as modern age water. Further, from the results of 14C it is inferred that some groundwater samples in Challaghatta valley belongs to old water regime with pmC values ranging between 58 and 112

    Concurrent, Multi-band, Single-Chain Radio Receiver for High Data-Rate HetNets

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    A concurrent, tunable, triple-band, single chain radio receiver for 5G radio access networks is presented and its performance is evaluated in a hardware-in-the-loop test-bed. The test-bed emulates a 5G heterogeneous network supporting three independently tunable, wideband, simultaneous connections over a frequency range from 600 MHz to 2.7 GHz. The single chain receiver is able to achieve an aggregate bandwidth of 93.75 MHz, 31.25 MHz per band, and a net data rate of 187.5 Mbit/s through the use of single-carrier QPSK transmissions. The receiver demonstrate sufficient isolation between the concurrent transmissions as well as strong resilience to adjacent blockers through the use of a small guard band

    Turbulent Compressible Convection with Rotation - Penetration above a Convection Zone

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    We perform Large eddy simulations of turbulent compressible convection in stellar-type convection zones by solving the Navi\'{e}r-Stokes equations in three dimensions. We estimate the extent of penetration into the stable layer above a stellar-type convection zone by varying the rotation rate ({\boldmathΩ\rm\Omega}), the inclination of the rotation vector (Ξ\theta) and the relative stability (SS) of the upper stable layer. The computational domain is a rectangular box in an f-plane configuration and is divided into two regions of unstable and stable stratification with the stable layer placed above the convectively unstable layer. Several models have been computed and the penetration distance into the stable layer above the convection zone is estimated by determining the position where time averaged kinetic energy flux has the first zero in the upper stable layer. The vertical grid spacing in all the model is non-uniform, and is less in the upper region so that the flows are better resolved in the region of interest. We find that the penetration distance increases as the rotation rate increases for the case when the rotation vector is aligned with the vertical axis. However, with the increase in the stability of the upper stable layer, the upward penetration distance decreases. Since we are not able to afford computations with finer resolution for all the models, we compute a number of models to see the effect of increased resolution on the upward penetration. In addition, we estimate the upper limit on the upward convective penetration from stellar convective cores.Comment: Accepted for Publication in Asttrophysics & Space Scienc

    Tunable, Concurrent Multiband, Single Chain Radio Architecture for Low Energy 5G-RANs

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    This invited paper considers a key next step in the design of radio architectures aimed at supporting low energy consumption in 5G heterogeneous radio access networks. State-of-the-art mobile radios usually require one RF transceiver per standard, each working separately at any given time. Software defined radios, while spanning a wide range of standards and frequency bands, also work separately at any specific time. In 5G radio access networks, where continuous, multiband connectivity is envisaged, this conventional radio architecture results in high network power consumption. In this paper, we propose the novel concept of a concurrent multiband frequency-agile radio (CM-FARAD) architecture, which simultaneously supports multiple standards and frequency bands using a single, tunable transceiver. We discuss the subsystem radio design approaches for enabling the CM-FARAD architecture, including antennas, power amplifiers, low noise amplifiers and analogue to digital converters. A working prototype of a dual-band CM-FARAD test-bed is also presented together with measured salient performance characteristics

    Modular Synthesis of Sketches Using Models

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    One problem with the constraint-based approaches to synthesis that have become popular over the last few years is that they only scale to relatively small routines, on the order of a few dozen lines of code. This paper presents a mechanism for modular reasoning that allows us to break larger synthesis problems into small manageable pieces. The approach builds on previous work in the verification community of using high-level specifications and partially interpreted functions (we call them models) in place of more complex pieces of code in order to make the analysis modular. The main contribution of this paper is to show how to combine these techniques with the counterexample guided synthesis approaches used to efficiently solve synthesis problems. Specifically, we show two new algorithms; one to efficiently synthesize functions that use models, and another one to synthesize functions while ensuring that the behavior of the resulting function will be in the set of behaviors allowed by the model. We have implemented our approach on top of the open-source Sketch synthesis system, and we demonstrate its effectiveness on several Sketch benchmark problems.National Science Foundation (U.S.) (Grant NSF-1116362)National Science Foundation (U.S.) (Grant NSF-1139056)United States. Dept. of Energy (Grant DE-SC0005372
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