Energy and precious fuels requirements of fuel alcohol production. Volume 4: Appendices G and H, methanol from coal

Coal mine location, mining technology, energy consumption in mining, coal transport, and potential availability of coal are discussed. Methanol from coal is also discussed

Viscous three-dimensional analyses for nozzles for hypersonic propulsion

A Navier-Stokes computer code was validated using a number of two- and three-dimensional configurations for both laminar and turbulent flows. The validation data covers a range of freestream Mach numbers from 3 to 14, includes wall pressures, velocity profiles, and skin friction. Nozzle flow fields computed for a generic scramjet nozzle from Mach 3 to 20, wall pressures, wall skin friction values, heat transfer values, and overall performance are presented. In addition, three-dimensional solutions obtained for two asymmetric, single expansion ramp nozzles at a pressure ratio of 10 consists of the internal expansion region in the converging/diverging sections and the external supersonic exhaust in a quiescent ambient environment. The fundamental characteristics that were captured successfully include expansion fans; Mach wave reflections; mixing layers; and nonsymmetrical, multiple inviscid cell, supersonic exhausts. Comparison with experimental data for wall pressure distributions at the center planes shows good agreement

Numerical Toy-Model Calculation of the Nucleon Spin Autocorrelation Function in a Supernova Core

We develop a simple model for the evolution of a nucleon spin in a hot and dense nuclear medium. A given nucleon is limited to one-dimensional motion in a distribution of external, spin-dependent scattering potentials. We calculate the nucleon spin autocorrelation function numerically for a variety of potential densities and distributions which are meant to bracket realistic conditions in a supernova core. For all plausible configurations the width of the spin-density structure function is found to be less than the temperature. This is in contrast with a naive perturbative calculation based on the one-pion exchange potential which overestimates the width and thus suggests a large suppression of the neutrino opacities by nucleon spin fluctuations. Our results suggest that it may be justified to neglect the collisional broadening of the spin-density structure function for the purpose of estimating the neutrino opacities in the deep inner core of a supernova. On the other hand, we find no indication that processes such as axion or neutrino pair emission, which depend on nucleon spin fluctuations, are substantially suppressed beyond the multiple-scattering effect already discussed in the literature. Aside from these practical conclusions, our model reveals a number of interesting and unexpected insights. For example, the spin-relaxation rate saturates with increasing potential strength only if bound states are not allowed to form by including a repulsive core. There is no saturation with increasing density of scattering potentials until localized eigenstates of energy begin to form.Comment: 14 latex pages in two-column format, 15 postscript figures included, uses revtex.sty and epsf.sty. Submitted to Physical Review

Carrier induced ferromagnetism in concentrated and diluted local-moment systems

For modeling the magnetic properties of concentrated and diluted magnetic semiconductors, we use the Kondo-lattice model. The magnetic phase diagram is derived by inspecting the static susceptibility of itinerant band electrons, which are exchange coupled to localized magnetic moments. It turns out that rather low band occupations favour a ferromagnetic ordering of the local moment systems due to an indirect coupling mediated by a spin polarization of the itinerant charge carriers. The disorder in diluted systems is treated by adding a CPA-type concept to the theory. For almost all moment concentrations x, ferromagnetism is possible, however, only for carrier concentrations n distinctly smaller than x. The charge carrier compensation in real magnetic semiconductors (in Ga_{1-x}Mn_{x}As by e.g. antisites) seems to be a necessary condition for getting carrier induced ferromagnetism.Comment: 9 pages (REVTeX), 6 figures, to be published in Phys. Rev.

Fuzzy Logic Controller for grid connected Wind Energy Conversion System

The use of renewable power sources, like wind power, has been increased recently due to climatic changes caused by fossil fuels and fast depletion of fossil fuels. This has lead to the tremendous increase in the interconnection of wind turbines to power system grid. This interconnection on a large number in to grid causes problems such as power quality, maintaining system voltage, reactive power compensation, control of grid frequency and aspects of power system grid stability. In this proposed scheme, a fuzzy logic based controller is employed for a STATCOM to improve the power quality. The proposed control scheme supplies the required reactive power to the system and thus relieves the source, leading to Unity Power Factor (UPF) at the source and also it injects currents to reduce total harmonic distortion (THD) to satisfy IEC standard. For extracting the reference currents, an instantaneous reactive power theory based control algorithm is employed. To determine the effectiveness of the proposed fuzzy logic controller, a comparative analysis is also performed with a PI controller and the results have been presented

Study on Mangrove Ecology and Impact in Kakinada Bay

The southern fringes of the Kakinada Bay are predominantly mud-flats interrupted by creeks/rivers which traverse, at the hayw ard end , through dense forests of mangrove as mentioned by Ramasarma and Ganapathi (1968) in their study on the Bay hydrography. The larger trees are located at a height of 03 m in relation to creek river low water level but in high tide and spring tides major parts are innundated. A part of the system forms a fringe along the eroding creek/river banks with roots in the water but on the bay-ward side the trees are succeeded by vascular plants, the shrubs and grasses on the mudflats due, probably, to show encroachment and reclamation for human habitation and paddyfields. especially in Matlapalem creek (Rajyalakshmi. 1975). However, the creeks are highly saline in non-monsoonal seasons, deep with a directional flow towards the Bay

Effect of Plant Growth Regulators on Corm Production and Vase Life in Gladiolus

Influence of plant growth regulator sprays on corm production and post-harvest life of two gladiolus cultivars, Darshan and Dhiraj, was investigated for two consecutive years, 2008-09 and 2009-10. Growth regulators, viz., gibberellic acid (100 and 150ppm), tri-iodo benzoic acid (TIBA) (50 and 100ppm), 2-chloro, 4-pyridyl phenyl urea (CPPU) (2.5 and 5ppm) and brassinosteroid (BR) (5 and 10ppm) were sprayed at the 3rd and 6thleaf stage. Cv. Darshan recorded maximum number of large cormels per plant and cormel weight, while, cv. Dhiraj recorded maximum number of small cormels per plant in treatments of pre-harvest foliar sprays with plant growth regulators. Foliar sprays of BR (10ppm) and GA3 (150ppm) significantly increased number of corms produced per plant, corm size, corm weight, and propagation coefficient. Number of large cormels and total number of cormels per plant were significantly higher in BR (10ppm), followed by TIBA (100ppm). BR (10ppm) and TIBA (100ppm) produced maximum number of small cormels per plant. Weight of cormels per plant was maximum in BR (10ppm) and GA3 (150ppm). Post-harvest studies revealed that cv. Darshan recorded maximum diameter of second fully-opened floret and higher vase-life than cv. Dhiraj with pre-harvest foliar spray of plant growth regulators. Pre-harvest foliar spray of GA3 (150ppm), BR (10ppm) and CPPU (5ppm) induced earliest first-floret opening and recorded maximum value for number-of-floretsopen- at-a-time per spike, diameter of second fully-opened floret, and vase-life. Foliar spray of BR (10ppm) and GA3 (150ppm) at 3rd and 6th leaf stage can be recommended for large-scale multiplication of quality planting material and longer vase-life of flower spikes, respectively, in gladiolus

New Experimental Limit on the Electric Dipole Moment of the Electron in a Paramagnetic Insulator

We report results of an experimental search for the intrinsic Electric Dipole Moment (EDM) of the electron using a solid-state technique. The experiment employs a paramagnetic, insulating gadolinium gallium garnet (GGG) that has a large magnetic response at low temperatures. The presence of the eEDM would lead to a small but non-zero magnetization as the GGG sample is subject to a strong electric field. We search for the resulting Stark-induced magnetization with a sensitive magnetometer. Recent progress on the suppression of several sources of background allows the experiment to run free of spurious signals at the level of the statistical uncertainties. We report our first limit on the eEDM of $(-5.57 \pm 7.98 \pm 0.12)\times$10$^{-25}$e$\cdot$cm with 5 days of data averaging.Comment: 9 pages, 9 figures, Revtex 4.

Non-Compositional Term Dependence for Information Retrieval

Modelling term dependence in IR aims to identify co-occurring terms that are too heavily dependent on each other to be treated as a bag of words, and to adapt the indexing and ranking accordingly. Dependent terms are predominantly identified using lexical frequency statistics, assuming that (a) if terms co-occur often enough in some corpus, they are semantically dependent; (b) the more often they co-occur, the more semantically dependent they are. This assumption is not always correct: the frequency of co-occurring terms can be separate from the strength of their semantic dependence. E.g. "red tape" might be overall less frequent than "tape measure" in some corpus, but this does not mean that "red"+"tape" are less dependent than "tape"+"measure". This is especially the case for non-compositional phrases, i.e. phrases whose meaning cannot be composed from the individual meanings of their terms (such as the phrase "red tape" meaning bureaucracy). Motivated by this lack of distinction between the frequency and strength of term dependence in IR, we present a principled approach for handling term dependence in queries, using both lexical frequency and semantic evidence. We focus on non-compositional phrases, extending a recent unsupervised model for their detection [21] to IR. Our approach, integrated into ranking using Markov Random Fields [31], yields effectiveness gains over competitive TREC baselines, showing that there is still room for improvement in the very well-studied area of term dependence in IR

Influence of process parameters on physical dimensions of AA6063 aluminium alloy coating on mild steel in friction surfacing

AbstractAn attempt is made in the present study to obtain the relationships among process parameters and physical dimensions of AA6063 aluminium alloy coating on IS2062 mild steel obtained through friction surfacing and their impact on strength and ductility of the coating. Factorial experimental design technique was used to investigate and select the parameter combination to achieve a coating with adequate strength and ductility. Spindle speed, axial force and table traverse speed were observed to be the most significant factors on physical dimensions. It was observed that the thickness of the coating decreased as the coating width increased. In addition, the width and thickness of the coatings are higher at low and high torques. At intermediate torque values, when the force is high, the width of the coating is high, and its thickness is thin; and when the force is low, the width and thickness are low. The interaction effect between axial force (F) – table traverse speed (Vx) and spindle speed (N) – table traverse speed (Vx) produced an increasing effect on coating width and thickness, but other interactions exhibited decreasing influence. It has also been observed that sound coatings could be obtained in a narrow set of parameter range as the substrate-coating materials are metallurgically incompatible and have a propensity to form brittle intermetallics