196,525 research outputs found
Computational approaches for urban environments: An editorial
No full textCities are under continuous pressure due to an increasing urbanization which will have far-reaching consequences for housing, transportation, retail, etc. To cope with these challenges, methodological advances in quantitative modeling coupled with growing amounts of spatial and spatiotemporal data can add significantly to our understanding of how cities function. Because the added value of data-driven approaches to analyze urban environments is promising but still in its infancy, the present volume aims to promote the application of advanced computational methodologies to achieve a better understanding of our cities and the underlying mechanisms
Modified Silicon Nanosheets and Their Composites – Novel 2D Material for Photonic Sensor Applications
No full textSilicon is consequently present in our every-day lives. We can find it not only as a semiconductor in electronics and photovoltaic applications, but also in silicon based products for the use in e.g., computers, textiles, household and automobiles.[1] Nevertheless, the applications variety can be increased with the downscaling of their size to two-, one- or even zero-dimensional silicon. Hence, new useful properties of the thus generated novel materials can be made accessible: a band gap starts to appear, the material can become semiconductive and additionally photoluminescence (PL) is detected.[2]
Herein we present the application of hydrogenated two-dimensional (2D) silicon. It is buckled, shows green PL and has a non-zero band gap.[3] Thus, after the successful modification of the surface for protection towards external influences[4], the first silicon nanosheets based field-effect transistor was fabricated.[5] Furthermore, we present the first use of the 2D sheets as sensitive material for a photonic sensor.[6] In spite of the already reached remarkable goals, there is still a wider range of applications, waiting to be explored and investigated.
[1] S. T. Walsh et al. Technological Forecasting and Social Change, 2005, 72, 213. [2] B. K. Teo et al. Chem Rev., 2007, 107, 1454. [3] T. Helbich et al. Chem. - A Eur. J., 2016, 10.1002/chem.201505134. [4] T. Helbich et al. Adv. Funct. Mater., 2016, 21, 6711. [5] T. Helbich*, A. Lyuleeva* et al. Adv. Funct. Mater., 2017, accepted. (6] A. Lyuleeva et al. J. Phys. D: Appl. Phys., 2017, 50, 135106
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
Modified 2D Silicon Nanosheets in Electronics: From Synthesis to Application
No full textSilicon nanosheets (SiNSs) are a fairly new class of 2D materials. But they are baring a great potential in terms of physical properties, such as band gap and conductivity control.[1], [2] Nevertheless, oxygen and UV light tend to destroy the two-dimensional material within seconds.[3], [4] To protect the surface, different covalent hydrosilylation reactions with a variety of functional molecules have been carried out to introduce stabilization of the sheets in ambient conditions. Thus, hybrid systems based on organic molecules and inorganic nanosheets were synthesized, which maintain both materials properties. The increase in lifetime is a major advantage, gained with the help of the surface chemistry.[5] This advantage can be used for the fabrication of new nanohybrid systems based electronics with faster performances. Even flexible surfaces can be used, bringing these studies closer to the so called wearables.
In this connection, we present not only the first prototype of a highly sensitive photonic sensor[6], but also solution-gated field-effect transistors, which performance is controllable via SiNSs’ surface groups.[7] Furthermore, a capacitive humidity sensor will be presented, which is currently being developed. It shows first steps towards surrounding molecules detection. Monitoring of the conditions, based on water and temperature control, can be performed. In summary, a facile integration of the herewith presented modified SiNSs into the already well-known fabrication methods could allow the manufacturing of even more various (opto)electronic devices.
[1] H. Okamoto et al. “Synthesis and modification of silicon nanosheets and other silicon nanomaterials.,” Chemi. Eur. J., vol. 17, no. 36, pp. 9864–87, Aug. 2011.
[2] C. Grazianetti et al. “Silicon Nanosheets: Crossover between Multilayer Silicene and Diamond-like Growth Regime,” ACS Nano, p. acsnano.7b00762, 2017.
[3] T. Helbich et al. “Radical-Induced Hydrosilylation Reactions for the Functionalization of Two-Dimensional Hydride Terminated Silicon Nanosheets,” Chem. - A Eur. J., p. Chem. Eur. J. 10.1002/chem.201505134, 2016.
[4] T. Helbich et al. “Diaryliodonium salts as hydrosilylation initiators for the surface functionalization of silicon nanomaterials and their collaborative effect as ring opening polymerization initiators,” Nanoscale, vol. 9, no. 23, 2017.
[5] T. Helbich et al. “One-Step Synthesis of Photoluminescent Covalent Polymeric Nanocomposites from 2D Silicon Nanosheets,” Adv. Funct. Mater., vol. 26, no. 37, pp. 6711–6718, 2016.
[6] A. Lyuleeva et al. “Polymer-silicon nanosheet composites: bridging the way to optoelectronic applications,” J. Phys. D. Appl. Phys., vol. 50, no. 13, p. 135106, 2017.
[7] T. Helbich et al. “Lewis Acid Induced Functionalization of Photoluminescent Two-Dimensional Silicon Nanosheets for the Fabrication of Functional Hybrid Films,” Adv. Funct. Mater., p. 1606764, 201
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Dr. Glendon Swarthout
No full textHosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
Introduction to OpenStreetMap in GIScience : Experiences, research, and applications
No full textRecent years have seen new ways of collecting geographic information via the crowd rather than organizations. OpenStreetMap (OSM) is a prime example of this approach and has brought free access to a wealth of geographic information—for many parts of the world, for the first time. The strong growth in the last few years made more and more people consider it as a potential alternative to commercial or authoritative data. The increasing availability of ever-richer data sets of freely available geographic information led to strong interest of researchers and practitioners in the usability of this data—both its limitations and potential. Both the unconventional way the data is being produced as well as its richness and heterogeneity have led to a range of different research questions on how we can assess, mine, enrich, or just use this data in different domains and for a wide range of applications. While this book cannot present all types of research around OpenStreetMap or even the broader category of User Generated Content (UGC) or Volunteered Geographic Information (VGI), it attempts to provide an overview of the current state of the art by presenting some typical and recent examples of work in GIScience on OSM. This chapter provides an introduction to the scholarly work on OpenStreetMap and its current state and summarizes the contributions to this book
Simulation of thermal plant optimization and hydraulic aspects of thermal distribution loops for large campuses
No full textFollowing an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied
Replication Data: Traffic noise assessment in urban Bulgaria using explainable machine learning
No full textThis data package contains the input data and analytical results of a machine learning-based traffic noise prediction model for the five largest Bulgarian cities. The model was trained based on measurement data from 232 fixed-site monitors. Noise measurements (A-weighted, in dB) were taken from 2018 to 2022 through calibrated sound level meters three times a day over two daytime periods between 07.00 and 19.00 h following ISO 1996-2 protocol norms. The noise predictions obtained through the extreme gradient boosting model and transport- and land-use-related predictors are shared as GeoTIFF files for each city on a 50 m raster. The raster layers are shipped in the projected coordinate system for Bulgaria (EPSG code: 7801). The data processing and statistical analyses are carried out in the R environment. The R scripts, the input data, and the predictions are provided in this data repository. Detailed information about the file naming and data is given in the read-me file. This dataset is accompanied by a research article (Helbich et al. 2025, Traffic noise assessment in urban Bulgaria using explainable machine learning, Sustainable Cities and Society, in press). Contact persons are Marco Helbich ([email protected]) and Angel Dzhambov ([email protected])
- …
