Different effects of Ni and Co substitution on the transport properties of BaFe2As2

We report resistivity and Hall effect results on Ba(Fe1-xNix)2As2 and compare them with those in Ba(Fe1-xCox)2As2. The Hall number RH is negative for all x values from 0.01 to 0.14, which indicates that electron carriers dominate the transport both in the magnetic and paramagnetic regime. We analyse the data in the framework of a two-band model. Without any assumption on the number of carriers, we show that the electron resistivity can be estimated with good accuracy in the low temperature paramagnetic range. Although the phase diagrams of the two families are very similar with respect to the extra electrons added in the system, we find that the transport properties differ in several aspects. First, we evidence that the contribution of holes to the transport is more important for Ni doping than for Co doping. Secondly, Ni behaves as a stronger scatterer for the electrons, as the increase of the residual electron resistivity rho/x is about four times larger for Ni than for Co in the most doped samples.Comment: 8 pages, 8 figure

Geometric modeling for computer aided design

The primary goal of this grant has been the design and implementation of software to be used in the conceptual design of aerospace vehicles particularly focused on the elements of geometric design, graphical user interfaces, and the interaction of the multitude of software typically used in this engineering environment. This has resulted in the development of several analysis packages and design studies. These include two major software systems currently used in the conceptual level design of aerospace vehicles. These tools are SMART, the Solid Modeling Aerospace Research Tool, and EASIE, the Environment for Software Integration and Execution. Additional software tools were designed and implemented to address the needs of the engineer working in the conceptual design environment. SMART provides conceptual designers with a rapid prototyping capability and several engineering analysis capabilities. In addition, SMART has a carefully engineered user interface that makes it easy to learn and use. Finally, a number of specialty characteristics have been built into SMART which allow it to be used efficiently as a front end geometry processor for other analysis packages. EASIE provides a set of interactive utilities that simplify the task of building and executing computer aided design systems consisting of diverse, stand-alone, analysis codes. Resulting in a streamlining of the exchange of data between programs reducing errors and improving the efficiency. EASIE provides both a methodology and a collection of software tools to ease the task of coordinating engineering design and analysis codes

Bleeding changes after levonorgestrel 52-mg intrauterine system insertion for contraception in women with self-reported heavy menstrual bleeding.

BackgroundThe levonorgestrel 52-mg intrauterine system has proven efficacy for heavy menstrual bleeding treatment in clinical trials, but few data exist to demonstrate how rapidly the effects occur and the effects in women with self-reported heavy bleeding, as seen commonly in clinical practice.ObjectiveEvaluate changes in bleeding patterns in women with self-reported heavy menstrual bleeding before levonorgestrel 52-mg intrauterine system insertion.Study designA total of 1714 women aged 16-45 years old received a levonorgestrel 52-mg intrauterine system in a multicenter trial evaluating contraceptive efficacy and safety for up to 10 years. At screening, participants described their baseline menstrual bleeding patterns for the previous 3 months. Participants completed daily diaries with subjective evaluation of bleeding information for the first 2 years. For this analysis, we included women with at least 1 complete 28-day cycle of intrauterine system use and excluded women using a hormonal or copper intrauterine contraception in the month prior to study enrollment. We evaluated changes in menstrual bleeding and discontinuation for bleeding complaints per 28-day cycle over 26 cycles (2 years) in women who self-reported their baseline pattern as heavy. We also compared rates of amenorrhea, defined as no bleeding or spotting, within the entire study population in women with subjective heavy menstrual bleeding at baseline compared with those who did not complain of heavy menstrual bleeding.ResultsOf the 1513 women in this analysis, 150 (9.9%) reported baseline heavy menstrual bleeding. The majority of women reported no longer experiencing heavy menstrual bleeding by the end of cycle 1 (112/150, 74.7%) with even greater rates by cycle 2 (124/148, 83.8%). At the end of cycles 6, 13, and 26, 129 of 140 (92.1%; 95% confidence interval, 87.7%-96.6%), 114 of 123 (92.7%; 95% confidence interval, 88.1%-97.3%), and 100 of 103 (97.1%; 95% confidence interval, 93.8%-100%) women reported no heavy menstrual bleeding, respectively. After cycles 13 and 26, 63 of 123 (51.2%; 95% confidence interval, 42.4%-60.1%) and 66 of 103 (64.1%; 95% confidence interval, 54.8%-73.3%), respectively, reported their bleeding as amenorrhea or spotting only. A lower proportion of women with baseline self-reported heavy menstrual bleeding reported amenorrhea as compared with women in the overall study cohort without heavy menstrual bleeding at the end of 6 cycles (319 [25.5%] vs 21 [15.0%], P=.005) and 13 cycles (382 [34.4%] vs 26 [21.1%], P=.003); differences were not significant after 19 cycles (367 [37.2%] vs 36 [31.0%], P=.022) and 26 cycles (383 [43.5%] vs 38 [36.9%], P=.21). Only 4 (2.7%) women with baseline heavy menstrual bleeding discontinued for bleeding complaints (2 for heavy menstrual bleeding and 2 for irregular bleeding), all within the first year.ConclusionMost women who self-report heavy menstrual bleeding experience significant improvement quickly after levonorgestrel 52-mg intrauterine system insertion. Discontinuation for bleeding complaints among women with baseline heavy menstrual bleeding is very low

Flow Control in a Hybrid Satellite-Terrestrial Network: Analysis and Algorithm Design

The Internet is making its way into our day-to-day life. Start-up companies and industry leaders in communication networks are competing in the market place for offering new and high performance solutions to their increasing number of customers. Individuals that, due to their job characteristics have access to the Internet via their workplace desktop have quite a different experience with the cyberspace versus those that are accessing networking services from their homes. Typically, a common Internet ``surfer'' that connects from home, will be frustrated by the speed at which his/her service is working. This is due to the limits imposed by the classical dial-up connection, via an Internet Service Provider. To-date, various alternatives to this situation have been reported: access via cable television networks and access via satellite links, not to mention ISDN line solutions. The first alternative is more likely to be implemented in crowded areas where the cable infrastructure may be already in place. However there are studies that show that a large investment is necessary to cover vast areas with this kind of infrastructure. Major costs are primarily due to the effort of laying out cable. Satellite Internet on the other hand is not restricted to work in a given area. Satellites ``see'' virtually everywhere. However there are trade-offs concerning the available bandwidth and its allocation. Also, satellite Internet is primarily dedicated to persons that receive more data than they generate for output. In this thesis we pursue a study of the flow-control in a satellite-terrestrial network. An analysis study is first performed for the DirecPC Hybrid Internet service. Then different bandwidth allocation strategies are compared, with the performance criterion being the delay in interactive sessions. The best service obviously minimizes the delay. We present theoretical and analytical background on the interactive traffic modeling problem. Fractal-type traffic is fed into the network models and different performance metrics are measured and discussed. We end by concluding that in the event that a satellite-terrestrial network would exclusively be used for interactive users, the optimal policy is to first serve the connection that suffers the largest instantaneous delay

Time- and Cost-Optimal Parallel Algorithms for the Dominance and Visibility Graphs

The compaction step of integrated circuit design motivates associating several kinds of graphs with a collection of non-overlapping rectangles in the plane. These graphs are intended to capture various visibility relations amongst the rectangles in the collection. The contribution of this paper is to propose time- and cost-optimal algorithms to construct two such graphs, namely, the dominance graph (DG, for short) and the visibility graph (VG, for short). Specifically, we show that with a collection of n non-overlapping rectangles as input, both these structures can be constructed in θ (log n) time using n processors in the CREW model

Time-Optimal Tree Computations on Sparse Meshes

The main goal of this work is to fathom the suitability of the mesh with multiple broadcasting architecture (MMB) for some tree-related computations. We view our contribution at two levels: on the one hand, we exhibit time lower bounds for a number of tree-related problems on the MMB. On the other hand, we show that these lower bounds are tight by exhibiting time-optimal tree algorithms on the MMB. Specifically, we show that the task of encoding and/or decoding n-node binary and ordered trees cannot be solved faster than Ω(log n) time even if the MMB has an infinite number of processors. We then go on to show that this lower bound is tight. We also show that the task of reconstructing n-node binary trees and ordered trees from their traversais can be performed in O(1) time on the same architecture. Our algorithms rely on novel time-optimal algorithms on sequences of parentheses that we also develop

Straits and seaways: end members within the continuousspectrum of the dynamic connection between basins

Straits and seaways are fundamental connectors of oceans, seas and more rarely lakes. They areubiquitous in the modern geography and should be common in ancient landscapes. We compare their charac-teristics to improve our understanding of these features, with the aim to define better their geological use.We review geomorphological, oceanographic, geological and depositional characteristics based on well-doc-umented modern and ancient examples, with a stronger focus on the rock record.‘Strait’and‘seaway’are differentiated by their spatial and temporal scale. This influences the type and per-sistence of oceanographic circulation and sediment distribution. Straits are individual depositional systems,with predictable bedform and facies changes along the sediment transport pathway, whereas seaways are largerand longer-lived physiographic domains, composed of numerous depositional systems. Therefore, their strati-graphic signature in the rock record should be significantly different. We conclude that straits and seaways areend members of a continuum, giving rise to the occurrence of intermediate cases with transitional characteris-tics. The distinctive geological usage of the terms‘strait’and‘seaway’, even without sharp boundaries betweenend members, may be helpful for predicting their occurrence, stratigraphy, palaeogeography, biota distributionand potential distribution of reservoirs and seals for fossil resources and CO2storage

Straits and seaways: controls, processes and implications in modern and ancient systems

Straits and seaways are connections between basins, key areas for exchange and transfer of water, heat, biota and sediments, and they can influence regional and global climate. A better understanding of strait/seaway dynamics, their evolution and preserved deposits is, therefore, fundamental to reconstructing the palaeoecology, palaeogeography and stratigraphy of interconnected basins. Straits and seaways are also important for understanding climate dynamics in Earth's past, and for safely exploiting energy resources (fossil and renewable). This volume aims at improving the knowledge on this topic, and at providing a comprehensive collection of state-of-the-art works bringing together complementary disciplines. Even though studies on modern and ancient straits and seaways exist, they are not necessarily conceived towards a better geological understanding of these features as depositional systems in their own right. In this introduction, we emphasize the geological importance of straits and seaways, summarizing the content and key findings of the contributions on this topic. The articles included in this volume explore four main research themes related to straits and seaways: (1) occurrence and classification; (2) morphological features, facies and stratigraphic variability, sedimentary processes and dynamics; (3) tectonic and climatic controls, their feedback with climate changes; and (4) palaeogeographical reconstructions and preservation of associated deposits

Aharonov-Bohm interference in the presence of metallic mesoscopic cylinders

This work studies the interference of electrons in the presence of a line of magnetic flux surrounded by a normal-conducting mesoscopic cylinder at low temperature. It is found that, while there is a supplementary phase contribution from each electron of the mesoscopic cylinder, the sum of these individual supplementary phases is equal to zero, so that the presence of a normal-conducting mesoscopic ring at low temperature does not change the Aharonov-Bohm interference pattern of the incident electron. It is shown that it is not possible to ascertain by experimental observation that the shielding electrons have responded to the field of an incident electron, and at the same time to preserve the interference pattern of the incident electron. It is also shown that the measuring of the transient magnetic field in the region between the two paths of an electron interference experiment with an accuracy at least equal to the magnetic field of the incident electron generates a phase uncertainty which destroys the interference pattern.Comment: 15 pages, 5 Postscript figure