299,033 research outputs found

    Peculiar ground: the theology of Isaac Watts

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    The thesis is designed to demonstrate what was distinctive about Isaac Watts. It begins with a brief account of his life and background. There is no attempt at comprehensive coverage but rather a discussion of significant detail. Then follows a survey of Watts' work - first his poetry, then his prose. Watts' writings on the Atonement are critically analysed, followed by his views on election and predestination. The purpose here is to demonstrate that Watts had a profound commitment to traditional theology, in particular to the doctrine of substitutionary atonement. However, he displays a thoroughly humane and reasonable attitude to the difficulties posed by this doctrine, and by the doctrine of predestination. Watts could fairly be described as a follower of Baxter whom he much admired. His salient characteristics were common sense and devotion to Scripture. Against this background Watts' writings on the Trinity are considered. Here his pursuit of reason and his desire to help others and to reconcile conflicting opinions led him into much more stormy waters. His mature conviction was that God had covenanted with the pre-existent human soul of Christ in order to redeem the world. This mildly heretical doctrine, derived from Origen, served to deflect Watts from out and out Socinianism and Arianism, both of which creeds held a dangerous attraction for him. The possibility is explored that at the end of his life Watts had written tracts which were definitely Unitarian - and which were subsequently destroyed. This would account for the self-torturing anguish of the Solemn Address, Watts' desperate cry to God for help and guidance. Lastly, the 'peculiar' gifts of Isaac Watts are stressed, so that the success of his religious verse can be evaluated. The qualities which he displayed in all his writings combined to produce his 'System of Praise', his enduring legacy to the Christian church. His heresy has been forgotten. But Watts' heresy helps us to understand his hymns, and his hymns help us to understand his heresy

    “Practical Analysis of A Small Wind Turbine for Domestic Use on Latitude 7.0670N, Longitude 6.2670E”

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    This work focuses on the design and construction of a small wind turbine suitable for generating electricity in low wind speed regimeon Lat7.0670N, Long 6.2670Eat very low cost. The wind turbine was designed to generate 250 Watts of power at the rated speed of 6.5m/s. In the design process,the various components of the wind turbine were considered and all the loads liable to occur during all temporary and operating conditions were calculated theoretically and the designs were optimized to ensure that the turbine operates at full capacity.The turbine’s performance was such that generation hovered between 60 and 100 in the months of October and November while it skyrocket towards 200 watts in the month of December.From performance point of view the turbine has proved to be relatively efficient for power generation in Auchi, Edo state where this work was carried out

    Radar systems for the water resources mission. Volume 4: Appendices E-I

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    The use of a scanning antenna beam for a synthetic aperture system was examined. When the resolution required was modest, the radar did not use all the time the beam was passing a given point on the ground to build a synthetic aperture, so time was available to scan the beam to other positions and build several images at different ranges. The scanning synthetic-aperture radar (SCANSAR) could achieve swathwidths of well over 100 km with modest antenna size. Design considerations for a SCANSAR for hydrologic parameter observation are presented. Because of the high sensitivity to soil moisture at angles of incidence near vertical, a 7 to 22 deg swath was considered for that application. For snow and ice monitoring, a 22 to 37 deg scan was used. Frequencies from X-band to L-band were used in the design studies, but the proposed system operated in C-band at 4.75 GHz. It achieved an azimuth resolution of about 50 meters at all angles, with a range resolution varying from 150 meters at 7 deg to 31 meters at 37 deg. The antenna required an aperture of 3 x 4.16 meters, and the average transmitter power was under 2 watts

    Design of multihundredwatt DIPS for robotic space missions

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    Design of a dynamic isotope power system (DIPS) general purpose heat source (GPHS) and small free piston Stirling engine (FPSE) is being pursued as a potential lower cost alternative to radioisotope thermoelectric generators (RTG's). The design is targeted at the power needs of future unmanned deep space and planetary surface exploration missions ranging from scientific probes to SEI precursor missions. These are multihundredwatt missions. The incentive for any dynamic system is that it can save fuel which reduces cost and radiological hazard. However, unlike a conventional DIPS based on turbomachinery converions, the small Stirling DIPS can be advantageously scaled to multihundred watt unit size while preserving size and weight competitiveness with RTG's. Stirling conversion extends the range where dynamic systems are competitive to hundreds of watts (a power range not previously considered for dynamic systems). The challenge of course is to demonstrate reliability similar to RTG experience. Since the competative potential of FPSE as an isotope converter was first identified, work has focused on the feasibility of directly integrating GPHS with the Stirling heater head. Extensive thermal modeling of various radiatively coupled heat source/heater head geometries were performed using data furnished by the developers of FPSE and GPHS. The analysis indicates that, for the 1050 K heater head configurations considered, GPHS fuel clad temperatures remain within safe operating limits under all conditions including shutdown of one engine. Based on these results, preliminary characterizations of multihundred watt units were established

    Climatologically significant effects of space-time averaging in the North Atlantic sea - air heat flux fields

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    Differences between “classical” and “sampling” estimates of mean climatological heat fluxes and their seasonal and interannual variability are considered on the basis of individual marine observations from the Comprehensive Ocean–Atmosphere Data Set. Calculations of fluxes were done for intramonthly averaging and for 1°–5° spatial averaging. Sampling estimates give in general 10% to 60% higher values of fluxes than do classical estimates. Spatial averaging has a larger effect than temporal averaging in the Tropics and subtropics, and temporal averaging is more effective than spatial averaging in midlatitudes. The largest absolute differences between sampling and classical estimates of fluxes are observed in middle latitudes, where they are 15 to 20 W m−2 for sensible heat flux and 50 to 70 W m−2 for latent heat flux. Differences between sampling and classical estimates can change the annual cycle of sea–air fluxes. There is a secular tendency of increasing “sampling- to-classical” ratios of 1% to 5% decade−1 over the North Atlantic. Relationships between sampling-to-classical ratios and parameters of the sea–air interface, the number of observations, and the spatial arrangement of samples are considered. Climatologically significant differences between sampling and classical estimates are analyzed in terms of the contribution from different covariances between individual variables. The influence of different parameterizations of the transfer coefficients on sampling minus classical differences is considered. Parameterizations that indicate growing transfer coefficients with wind speed give the larger sampling minus classical differences in comparison with those based on either constant or decreasing with wind coefficients. Nevertheless, over the North Atlantic midlatitudes, all parameterizations indicate significant sampling minus classical differences of about several tens of watts per square meter. The importance of differences between sampling and classical estimates for the evaluation of meridional heat transport shows that differences between sampling and classical estimates can lead to 0.5–1-PW differences in meridional heat transport estimates

    Design of a Low‐Cost Permanent Synchronous Machine for Isolated Wind Conversion Systems

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    The chapter deals with the theoretical analysis of two configurations of low‐cost permanent synchronous generator (PMSG), suitable for small rating, direct driven applications, such as small‐ and microscale wind power plants. The first structure is a permanent magnet claw‐pole synchronous generator (PMCPSG) to be used in an isolated microwind power plants with installed power around few hundred Watts. A permanent magnet synchronous machine with outer rotor (PMSMOR) is the second presented structure, suitable for small wind system with installed power between 2 and 5 kW. In order to obtain the optimal value of the main geometric dimensions of the generators, an optimization procedure, based on Hooke‐Jeeves method, was implemented for all the considered structures

    Unimodular lattice triangulations as small-world and scale-free random graphs

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    Real-world networks, e.g. the social relations or world-wide-web graphs, exhibit both small-world and scale-free behaviour. We interpret lattice triangulations as planar graphs by identifying triangulation vertices with graph nodes and one-dimensional simplices with edges. Since these triangulations are ergodic with respect to a certain Pachner flip, applying different Monte-Carlo simulations enables us to calculate average properties of random triangulations, as well as canonical ensemble averages using an energy functional that is approximately the variance of the degree distribution. All considered triangulations have clustering coefficients comparable with real world graphs, for the canonical ensemble there are inverse temperatures with small shortest path length independent of system size. Tuning the inverse temperature to a quasi-critical value leads to an indication of scale-free behaviour for degrees k≄5k \geq 5. Using triangulations as a random graph model can improve the understanding of real-world networks, especially if the actual distance of the embedded nodes becomes important.Comment: 17 pages, 6 figures, will appear in New J. Phy

    Economic Small-World Behavior in Weighted Networks

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    The small-world phenomenon has been already the subject of a huge variety of papers, showing its appeareance in a variety of systems. However, some big holes still remain to be filled, as the commonly adopted mathematical formulation suffers from a variety of limitations, that make it unsuitable to provide a general tool of analysis for real networks, and not just for mathematical (topological) abstractions. In this paper we show where the major problems arise, and how there is therefore the need for a new reformulation of the small-world concept. Together with an analysis of the variables involved, we then propose a new theory of small-world networks based on two leading concepts: efficiency and cost. Efficiency measures how well information propagates over the network, and cost measures how expensive it is to build a network. The combination of these factors leads us to introduce the concept of {\em economic small worlds}, that formalizes the idea of networks that are "cheap" to build, and nevertheless efficient in propagating information, both at global and local scale. This new concept is shown to overcome all the limitations proper of the so-far commonly adopted formulation, and to provide an adequate tool to quantitatively analyze the behaviour of complex networks in the real world. Various complex systems are analyzed, ranging from the realm of neural networks, to social sciences, to communication and transportation networks. In each case, economic small worlds are found. Moreover, using the economic small-world framework, the construction principles of these networks can be quantitatively analyzed and compared, giving good insights on how efficiency and economy principles combine up to shape all these systems.Comment: 17 pages, 10 figures, 4 table
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