The construction, utilization, and evaluation of a series of exercises designed to improve the oral language of second grade children

Thesis (Ed.M.)--Boston Universit

Evaluation of a prototype air-assist agricultural sprayer nozzle

Droplet spectra and lateral spray distributions from a proto type air-assist agricultural sprayer nozzle were observed and evaluated at the United States Department of Agriculture-Agricultural Research Service (USDA-ARS) in Beltsville, Maryland and at The University of Tennessee Department of Agricultural Engineering in Knoxville, Tennessee. Evaluations considered the effects of various air and liquid pressure combinations, different liquid physical properties, and other operational variables on the spray emitted by the nozzle unit. Evaluations of droplet spectra from six nozzle tips and at various positions within a given distribution were also performed. Data describing the droplet spectra were collected using a helium-neon laser spectrometer. Air pressures of 34, 52, and 69 kPa in combination with liquid pressures of 207, 276, 345, and 414 kPa were used during the evaluation. Tapwater, a hard well water, distilled water, and an oil-in-water solution were used to analyze the effects of various liquid properties on droplet spectra emitted from the nozzle. Changes in the volume-surface (Sauter) mean diameter (SMD), the volume median diameter (VMD), and the 10 and 90 percent intercepts on the cumulative volume curve (DV1 and DV9, respectively) were analyzed for all test conditions. Data characterizing the lateral spray distributions from the air-assist nozzle were collected using a patternator. The air and liquid pressures noted above were used during the evaluation. Only tapwater and the oil-in-water solution were tested for their effects on the spray pattern emitted by the nozzle. Boom heights were 43, 48, and 53 cm above the patternator surface. Coefficients of variation for the lateral spray distributions produced were used to determine the appropriate nozzle spacing along the boom. Results from the droplet spectra analyses suggest that droplet size decreases as air pressure is increased for a given liquid pressure; however, droplet size increases as liquid pressure increases for a given air pressure. The latter trend is opposite that which occurs in conventional hydraulic atomizers. These phenomena occurred for all liquids tested. Further, the evaluation indicated that little variation existed among the droplet diameters analyzed for liquid pressures of 276 kPa and 345 kPa in combination with the 52 kPa air pressure setting for the oil-in-water solution. The same trend was observed for tapwater at the same liquid pressures, but in combination with all air pressures

Probing the local dynamics of periodic orbits by the generalized alignment index (GALI) method

As originally formulated, the Generalized Alignment Index (GALI) method of chaos detection has so far been applied to distinguish quasiperiodic from chaotic motion in conservative nonlinear dynamical systems. In this paper we extend its realm of applicability by using it to investigate the local dynamics of periodic orbits. We show theoretically and verify numerically that for stable periodic orbits the GALIs tend to zero following particular power laws for Hamiltonian flows, while they fluctuate around non-zero values for symplectic maps. By comparison, the GALIs of unstable periodic orbits tend exponentially to zero, both for flows and maps. We also apply the GALIs for investigating the dynamics in the neighborhood of periodic orbits, and show that for chaotic solutions influenced by the homoclinic tangle of unstable periodic orbits, the GALIs can exhibit a remarkable oscillatory behavior during which their amplitudes change by many orders of magnitude. Finally, we use the GALI method to elucidate further the connection between the dynamics of Hamiltonian flows and symplectic maps. In particular, we show that, using for the computation of GALIs the components of deviation vectors orthogonal to the direction of motion, the indices of stable periodic orbits behave for flows as they do for maps.Comment: 17 pages, 9 figures (accepted for publication in Int. J. of Bifurcation and Chaos

Conformal Magnetic Composite RFID for Wearable RF and Bio-Monitoring Applications

©2008 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or distribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.10.1109/TMTT.2008.2006810This paper introduces for the first time a novel flexible magnetic composite material for RF identification (RFID) and wearable RF antennas. First, one conformal RFID tag working at 480 MHz is designed and fabricated as a benchmarking prototype and the miniaturization concept is verified. Then, the impact of the material is thoroughly investigated using a hybrid method involving electromagnetic and statistical tools. Two separate statistical experiments are performed, one for the analysis of the impact of the relative permittivity and permeability of the proposed material and the other for the evaluation of the impact of the dielectric and magnetic loss on the antenna performance. Finally, the effect of the bending of the antenna is investigated, both on the S-parameters and on the radiation pattern. The successful implementation of the flexible magnetic composite material enables the significant miniaturization of RF passives and antennas in UHF frequency bands, especially when conformal modules that can be easily fine-tuned are required in critical biomedical and pharmaceutical applications

Managing polyglot systems metadata with hypergraphs

A single type of data store can hardly fulfill every end-user requirements in the NoSQL world. Therefore, polyglot systems use different types of NoSQL datastores in combination. However, the heterogeneity of the data storage models makes managing the metadata a complex task in such systems, with only a handful of research carried out to address this. In this paper, we propose a hypergraph-based approach for representing the catalog of metadata in a polyglot system. Taking an existing common programming interface to NoSQL systems, we extend and formalize it as hypergraphs for managing metadata. Then, we define design constraints and query transformation rules for three representative data store types. Furthermore, we propose a simple query rewriting algorithm using the catalog itself for these data store types and provide a prototype implementation. Finally, we show the feasibility of our approach on a use case of an existing polyglot system.Peer ReviewedPostprint (author's final draft

Integrated Circuit (IC) Chip with a Self-Contained Fluid Sensor and Method of Making the Chip

An integrated circuit (IC) chip with a self-contained fluid sensor and method of making the chip. The sensor is in a conduit formed between a semiconductor substrate and a non-conductive cap with fluid entry and exit points through the cap. The conduit may be entirely in the cap, in the substrate or in both. The conduit includes encased temperature sensors at both ends and a central encased heater. The temperature sensors may each include multiple encased diodes and the heater may include multiple encased resistors

Jedno i više elementne mikrotrakaste monopolne antene Minkowskog za pokretne komunikacijske uređaje

In this paper a printed fractal Minkowski monopole is presented for use in wireless terminal devices utilizing single and multi element antenna systems. In the case of a single element system the effect of the antenna\u27s placement with respect to the ground plane is examined and a method to fine tune the system in its worst case situation is proposed. The influence of the ground plane dimensions on the system\u27s impedance and radiation characteristics is also investigated and general conclusions are drawn. Subsequently, a four element antenna system for diversity applications is investigated. The diversity performance is evaluated by means of the envelope correlation coefficient, the mean effective gain and the effective diversity gain. The impact of the mutual coupling on the system\u27s performance is also addressed.U radu je prikazana fraktalna monopolna antena Minkowskog. Ova je antena namijenjena pokretnim komunikacijskim uređajima s jednom ili više antena. U slučaju primjene jedne antene proučen je utjecaj njezinog položaja u odnosu na osnovnu vodljivu ravninu i predložen je postupak za fino ugađanje sustava u uvjetima najgoreg slučaja. Istražen je i utjecaj izmjera osnovne vodljive ravnine na ulaznu impedanciju antene i na njezine dijagrame zračenja te su izvedeni općeniti zaključci. Zatim je istražen i antenski niz od četiri takva elementa. Proučavane su karakteristike niza kada se niz koristi u uvjetima diverzitija. Karakteristike diverzitija vrednovane su pomoću korelacijskog koeficijenta anvelope, srednjeg efektivnog dobitka i efektivnog dobitka diverzitija. Razmotren je i utjecaj međusobne sprege antena na ukupne karakteristike antenskog sustava