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- Examining Error in the Technical Communication Editing Test
- This paper discusses examining errors in technical communication. Abstract: Usage error is a popular topic for technical communicators. However, its anecdotal discussions remain the best source of information on the errors that technical communicators might value over others. In this paper, the author reports the types and frequencies of errors found in 41 editing tests administered to prospective technical writers and editors. Results indicate that misspellings and faulty/missing capitalization were the most frequent and dispersed errors. Eight of the most frequent errors related to style; however, grammar punctuation errors remain the most dispersed. A larger dataset will better determine how technical communicators prioritize specific errors. digital.library.unt.edu/ark:/67531/metadc39326/
- GSV: a web-based genome synteny viewer for customized data
- This article discusses GSV, a web-based genome synteny viewer for customized data. Abstract: Background: The analysis of genome synteny is a common practice in comparative genomics. With the advent of DNA sequencing technologies, individual biologists can rapidly produce their genomic sequences of interest. Although web-based synteny visualization tools are convenient for biologists to use, none of the existing ones allow biologists to upload their own data for analysis. Results: The authors have developed the web-based Genome Synteny Viewer (GSV) that allows users to upload two data files for synteny visualization, the mandatory synteny file for specifying genomic positions of conserved regions and the optional genome annotation file. GSV presents two selected genomes in a single integrated view while still retaining the browsing flexibility necessary for exploring individual genomes. Users can browse and filter for genomic regions of interest, change the color or shape of each annotation track as well as re-order, hide or show the tracks dynamically. Additional features include downloadable images, immediate email notification and tracking of usage history. The entire GSV package is also light-weighted which enables easy local installation. Conclusions: GSV provides a unique option for biologists to analyze genome synteny by uploading their own data set to a web-based comparative genome browser. A web server hosting GSV is provided at http://cas.bioinfo.cas.unt.edu/gsv, and the software is also freely available for local installations. digital.library.unt.edu/ark:/67531/metadc77111/
- How to Hook a Hottie: Teenage Boys, Hegemonic Masculinity, and Cosmo Girl! Magazine
- This book chapter discusses different media texts targeted at a different audience, magazines written for an audience of teenaged girls, which also work to naturalize male sexuality as aggressive and predatory. The authors study advice columns and articles in these magazines that depict teenaged boys as sexually forceful and emotionally stunted, and that encourage girl readers to expect and enable such behaviors. digital.library.unt.edu/ark:/67531/metadc139467/
- Mapping Texts: Combining Text-Mining and Geo-Visualization To Unlock The Research Potential of Historical Newspapers
- This paper discusses a grant project to develop a series of experimental models for combining possibilities of text-mining with geospatial mapping in order to unlock the research potential of large-scale collections of historical newspapers. This paper documents the experiments and their outcomes, as well as the authors' recommendations for future work. digital.library.unt.edu/ark:/67531/metadc83797/
- Pediatric functional magnetic resonance neuroimaging: tactics for encouraging task compliance
- This article discusses pediatric functional magnetic resonance neuroimaging. Background: Neuroimaging technology has afforded advances in our understanding of normal and pathological brain function and development in children and adolescents. However, noncompliance involving the inability to remain in the magnetic resonance imaging (MRI) scanner to complete tasks is one common and significant problem. Task noncompliance is an especially significant problem in pediatric functional magnetic resonance imaging (fMRI) research because increases in noncompliance produces a greater risk that a study sample will not be representative of the study population. Method: In this preliminary investigation, the authors describe the development and application of an approach for increasing the number of fMRI tasks children complete during neuroimaging. Twenty-eight healthy children ages 9-13 years participated. Generalization of the approach was examined in additional fMRI and event-related potential investigations with children at risk for depression, children with anxiety and children with depression (N = 120). Essential features of the approach include a preference assessment for identifying multiple individualized rewards, increasing reinforcement rates during imaging by pairing tasks with chosen rewards and presenting a visual 'road map' listing tasks, rewards and current progress. Results: Our results showing a higher percentage of fMRI task completion by healthy children provides proof of concept data for the recommended tactics. Additional support was provided by results showing our approach generalized to several additional fMRI and event-related potential investigations and clinical populations. Discussion: The authors propose that some forms of task noncompliance may emerge from less than optimal reward protocols. While the authors' findings may not directly support the effectiveness of the multiple reward compliance protocol increased attention to how rewards are selected and delivered may aid cooperation with completing fMRI tasks. Conclusion: The proposed approach contributes to the pediatric neuroimaging literature by providing a useful way to conceptualize and measure task noncompliance and by providing simple cost effective tactics for improving the effectiveness of common reward-based protocols. digital.library.unt.edu/ark:/67531/metadc77157/
- Peer Review and the Ex Ante Assessment of Societal Impacts
- This article discusses peer review. Funding agencies and research councils around the world rely on peer review to assess the potential impacts of proposed research. This article compares the procedures of two major public science agencies - the US National Science Foundation and the European Commission's 7th Framework Programme - for evaluating ex ante the potential societal impact of research proposals. In this paper the authors survey the state of the art and discuss some of the conceptual questions that arise in using ex ante peer review to assess the societal impact of scientific research. digital.library.unt.edu/ark:/67531/metadc38888/
- Potential Hazards of Wind Energy For Rare, Tereatened, and Endangered Birds and Batsin Texas
- This article discusses the potential hazards of wind energy for rare, tereatened, and endangered birds and Batsin, Texas. The purpose of this study was to estimate relative potential hazard index (PHI) for 31 bird and ten bat species based upon the percentage of known or observed species range area (by county) within each wind speed classification. Results demonstrate considerable range in relative hazard, with the lesser prairie chicken and ferruginous hawk among the most potentially impacted birds; and the pale Townsend's bat, western small-footed bat, and big free-tailed bat among the most potentially impacted bats. While additional data are necessary to establish actual impacts of wind developments, relative potential hazard indices may help prioritize future studies. digital.library.unt.edu/ark:/67531/metadc152434/
- [Review] Nexus of Empire: Negotiating Loyalty and Identity in the Revolutionary Borderlands
- This book review discusses 'Nexus of Empire: Negotiating Loyalty and Identity in the Revolutionary Borderlands' edited by Gene Allen Smith and Sylvia L. Hilton. The book examines the individuals who inhabited the Gulf of Mexico regions, analyzing the ways in which these people defined and redefined themselves amid a world of competing loyalties. digital.library.unt.edu/ark:/67531/metadc39329/
- Spatial Distribution of Solutes in Aquifer Outcrop Zones along the Brazos River, East-Central Texas
- This articles discusses the spatial distribution of solutes in Aquifer outcrop zones along the Brazos River in east-central, Texas. Concentrations of several solutes - nitrate, arsenic, sulfate, boron, chloride, and bromide - along with total dissolved solids (TDS) in ten counties bordering the Brazos River in east-central, Texas were compiled, mapped, and analyzed relative to regional land use and geology. Agriculture and oil/gas production are major activities and potential sources of groundwater contamination in the study area. Data were compiled from 104 water wells with a median depth of 446 ft (136 m) in the outcrop zones of six sedimentary aquifers: Carizzo-Wilcox, Queen City, Sparta, Yegua-Jackson, Gulf Coast, and Brazos Alluvium. Only two observations surpassed the 44.3 mg/L drinking water standard for nitrate, and four observations exceeded the 10 ug/L standard for arsenic. The median chloride concentration was 53 mg/L; however, the maximum level was almost three times the secondary drinking water standard of 250 mg/L. Chloride, bromide, sulfate, and boron concentrations resembled TDS patterns, with numerous samples exceeding secondary TDS drinking water standards in the Yegua-Jackson Aquifer. Most chloride/bromide ratios were between 100 and 300. Overall, results of this study suggest that natural processes exert a primary control on solute concentrations in the above aquifers, with a potential for modest anthropogenic impacts from agriculture and oil/gas production. digital.library.unt.edu/ark:/67531/metadc152433/
- A Tribute to Carlos Augusto Angel Maya
- This article offers a tribute to Carlos Augusto Angel Maya. The authors explain Maya's life and work and his legacy of infinite value for the community of environmental thought in Colombia, in Latin America, and throughout the world. digital.library.unt.edu/ark:/67531/metadc97964/
- A Two-Coordinate Nickel Imido Complex That Effects C-H Amination
- This article discusses a two-coordinate nickel imido complex that effects C-H amination. An exceptionally low coordinate nickel imido complex, (IPr*)Ni=N(dmp) (2) (dmp=2,6-dimesitylphenyl), has been prepared by the elimination of N₂ from a bulky aryl azide in its reaction with (IPr*)Ni(ɳ⁶-C₇H₈) (1). The solid-state structure of 2 features two-coordinate nickel with a linear C-Ni-N core and a short Ni-N distance, both indicative of multiple-bond character. Computational studies using density functional theory showed a Ni=N bond dominated by Ni(dπ)-N(pπ) interactions, resulting in two nearly degenerate singly occupied molecular orbitals (SOMOs) that are Ni-N π* in character. Reaction of 2 with CO resulted in nitrene-group transfer to form (dmp)NCO and (IPr*)Ni(CO)₃ (3). Net C-H insertion was observed in the reaction of 2 with ethene, forming the vinylamine (dmp)NH(CH=CH₂) (5) via an azanickelacyclobutane intermediate, (IPr*)Ni{N,C:k²-N(dmp)CH₂CH₂} (4). digital.library.unt.edu/ark:/67531/metadc107785/
- On the mechanism for plasma hydrogenation of graphene
- In this article, the authors report that hydrogenation of mono-, bi-, and trilayer graphene samples via exposure to H2 plasma occurs as a result of electron irradiation of H2O adsorbates on the samples, rather than H species in the plasma as reported by [Elias et al., Science 323, 610 (2009)]. The authors propose that the hydrogenation mechanism is electron-impact fragmentation of H2O adsorbates into H+ ions. At incident electron energies >60 eV, the authors observe hydrogenation that is significantly more stable at temperatures >200 ºC than previously reported. digital.library.unt.edu/ark:/67531/metadc84155/
- Comparative Assessment of Peer Review (CAPR): EU/US workshop on peer review: Assessing "broader impact" in research grant applications
- This is the report of a workshop focusing on the use of broader societal impacts criteria as part of the review process at the European Commission. There is both a historical account and some thinking about how 'impact' ought to be incorporated into Horizon 2020 (the funding scheme formerly known as FP8). Since the US NSF is also currently rethinking the details of its merit review process, and since there is an interesting comparison between NSF's and the EC's approaches to impact, the authors have also included a focus on NSF's Broader Impacts Criterion. The workshop was both a research opportunity (under SciSIP grant #0830387) and an effort to use that research to help inform policy for science (in terms of informing peer review models). digital.library.unt.edu/ark:/67531/metadc86179/
- Delivering Pretzels in Berlin
- Front cover of the Winter 2009 issue of The Hexagon, featuring a man in a Berlin shirt riding a bicycle laden with large pretzels. A small dog on a leash follows alongside of him. The inside cover has a table of contents, a list of staff, and an editorial. digital.library.unt.edu/ark:/67531/metadc111239/
- Rediscovery of the Elements: Courtois and Iodine
- Article describing the history of iodine, including its discovery by Bernard Courtois while during the production of saltpeter. Tourist information regarding pertinent locations is included. digital.library.unt.edu/ark:/67531/metadc111240/
- Mathematical Correlations for Describing Solute Transfer into Functionalized Alkane Solvents Containing Hydroxyl, Ether, Ester or Ketone Solvents
- This article discusses mathematical correlations for describing solute transfer into functionalized alkane solvents containing hydroxyl, ether, ester or ketone solvents. Abstract: Gas-to-liquid and water-to-liquid partition coefficients have been compiled for more than 2800 different solute-solvent combinations. Solutes considered include acyclic monofunctional alkanols, dialkyl ethers, alkyl alkanoates and alkanones, as well difunctional alkoxyalcohols. Both sets of partition coefficients were analyzed using the Abraham solvation parameter model with fragment-specific equation coefficients. The derived equations correlated the experimental gas-to-alcohol and water-to-alcohol partition coefficient data to within 0.15 and 0.16 log units, respectively. The fragment-specific equation coefficients that have been calculated for the CH3, CH2, CH, C, OH, O, C(O)O and C=O fragment groups can be combined to yield expressions capable of predicting the partition coefficients of solutes in other anhydrous alkanol, dialkyl ether, alkyl alkanolate, alkanone and alkoxyalkanol solvents. digital.library.unt.edu/ark:/67531/metadc157290/
- Characteristic Male Urine Microbiomes Associate with Asymptomatic Sexually Transmitted Infection
- This article discusses characteristic male urine microbiomes. Abstract: Background: The microbiome of the male urogenital tract is poorly described but it has been suggested that bacterial colonization of the male urethra might impact risk of sexually transmitted infection (STI). Previous cultivation-dependent studies showed that a variety of non-pathogenic bacteria colonize the urethra but did not thoroughly characterize these microbiomes or establish links between the compositions of urethral microbiomes and STI. Methodology/Findings: Here, the authors used 165 rRNA PCR and sequencing to identify bacteria in urine specimens collected from men who lacked symptoms of urethral inflammation but who differed in status for STI. All of the urine samples contained multiple bacteria genera and many contained taxa that colonize the human vagina. Uncultivated bacteria associated with female genital tract pathology were abundant in specimens from men who had STI. Conclusions: Urine microbiomes from men with STI were dominated by fastidious, anaerobic and uncultivated bacteria. The same taxa were rare in STI negative individuals. The authors' findings suggest that the composition of male urine microbiomes is related to STI. digital.library.unt.edu/ark:/67531/metadc78333/
- Control of Root Architecture and Nodulation by the LATD/NIP Transporter
- This article discusses root architecture and nodulation. Abstract: The Medicago truncatula LATD/NIP gene is essential for the development of lateral and primary root and nitrogen-fixing nodule meristems as well as for rhizobial invasion of nodules. LATD/NIP encodes a member of the NRT1(PTR1) nitrate and di-and tri-peptide transporter family, suggesting that its function is to transport one of these or another compound(s). Because latd/nip mutants can have their lateral and primary root defects rescued by ABA, ABA is a potential substrate for transport. LATD/NIP expression in the root meristem was demonstrated to be regulated by auxin, cytokinin and abscisic acid, but not by nitrate. LATD/NIP's potential function and its role in coordinating root architecture and nodule formation are discussed. digital.library.unt.edu/ark:/67531/metadc40391/
- The Media and Communication Industries: A 21st Century Perspective
- This article discusses the media and communication industry. The media and communication industries are experiencing unprecedented change and evolution in the 21st century. This article examines this process with a case study method by analyzing the traditional and new media sectors using the following criteria: the markets in which they are engaged, the leaders in each of the respective industries, the economic potential of these industries, and their continuing evolution and transforming processes. The article argues that the media and communications industries can no longer be identified in terms of core sectors such as broadcasting or newspapers, but rather to a different structure of activities involving such areas as content, distribution, and search features. Further, the paper posits that new theoretical and methodological tools are needed by scholars to better understand the massive changes and transformation occurring across the media sector. A series of propositions concludes the paper, offering a framework on which to build future research and analysis. digital.library.unt.edu/ark:/67531/metadc30854/
- Coherent control of atomic excitation using off-resonant strong few-cycle pulses
- This article discusses coherent control of atomic excitation using off-resonant strong few-cycle pulses. Abstract: We study the dynamics of a two-level system driven by an off-resonance few-cycle pulse which has a phase jump ø at t = t₀, in contrast to many-cycle pulses, under the nonrotating-wave approximation (NRWA). We give a closed form analytical solution for the evolution of the probability amplitude |Cₐ(t)| for the upper level. Using the appropriate pulse parameters like the phase jump ø, jump time t₀, pulse width Շ, frequency ν, and Rabi frequency Ώ₀ the population transfer after the pulse is gone can be optimized and, for the pulse considered here, an enhancement factor of 10⁶-10⁸ was obtained. digital.library.unt.edu/ark:/67531/metadc103266/
- Observation of picosecond superfluorescent pulses in rubidium atomic vapor pumped by 100-fs laser pulses
- In this article, the authors study the superfluorescence (SF) from a gas of rubidium atoms. The atoms of a dense vapor are excited to the 5D state from the 5S state by a two-photon process driven by 100-fx laser pulses. The atoms decay to the 6P state and then to the 5S state. The SF emission at 420 nm on the 6P-5S transition is recorded by a streak camera with picosecond time resolution. The time duration of the generated SF is tens of picoseconds, which is much shorter than the time scale of the usual relaxation processes, including spontaneous emission and atomic coherence dephasing. The dependence of the time delay between the reference input pulse and SF is measured as a function of laser power. THe experimental data are described quantitatively by a simulation based on the semiclassical atom-field interaction theory. The observed change in scaling laws for the peak intensity and delay time can be elucidated by an SF theory in which the sample length is larger than the cooperation length. digital.library.unt.edu/ark:/67531/metadc103264/
- Phase Transition Enthalpy Measurements of Organic and Organometallic Compounds. Sublimation, Vaporization and Fusion Enthalpies From 1880 to 2010
- This article discusses phase transition enthalpy measurements of organic and organometallic compounds. A compendium of phase change enthalpies published within the period 1880-2010 is reported. Phase change enthalpies including fusion, vaporization, and sublimation are included for organic, organometallic, and a few inorganic compounds. This compendium is a combination of three previous series focusing on phase change enthalpies updated to 2009. Sufficient data are presently available for some compounds to permit thermodynamic cycles to be constructed, an important manner of evaluating the reliability of the measurements. Temperature adjustments of phase change enthalpies from the temperature of measurement to the standard reference temperature, T = 298.15 K, are briefly discussed and a protocol for doing so is illustrated. digital.library.unt.edu/ark:/67531/metadc152426/
- Rediscovery of the Elements: Ruthenium
- Article describing the discovery of platinum in Russia and the history of ruthenium. Tourist information regarding sites pertinent to this history are included. digital.library.unt.edu/ark:/67531/metadc111238/
- The Statue of Copernicus
- Front cover of the Summer 2009 issue of The Hexagon, featuring a statue of Copernicus sitting on a block, wearing a flowing robe, and holding a compass up to a heliocentric model. The next page contains a table of contents, a staff list, and an editorial regarding the twentieth anniversary of the events at Tiananmen Square. digital.library.unt.edu/ark:/67531/metadc111237/
- Through-Bond Interactions in the Diradical Intermediates Formed in the Rearrangements of Bicyclo[n.m.0]alkatetraenes
- This article discusses through-bond interactions. The intermediates and transition structures in the degenerate thermal rearrangements of bicyclo[4.4.0]deca-2,4,7,9-tetraene (1c), bicyclo[5.5.0]dodeca-2,4,8,10-tetraene(11b), and bicyclo[5.4.0]undeca-2.4.8.10-tetraene (14) have been located by (U)B3LYP/6-31G(d) calculations. The singlet-triplet energy differences (∆Est) in the diradical intermediates (tricyclo[4.4.0.02,7]deca-3,8-dien-5,10-diyl (2c), tricyclo[5.5.0.05,11]dodeca-2,8-dien-4,10-diyl (12b), and tricyclo[5.4.0.05,11]undeca-2,8-dien-4,10-diyl(15)) have been computed, using both UB3LYP and (6/6)CASPT2 calculations. ∆Est in 2c, in which a four-membered ring is anti-bridged by two allylic radicals, is computed to be larger by a factor of 5 than ∆Est in 15, in which the anti-bridged ring is five-membered, and by a factor of 10 than that in 12b, in which the anti-bridged ring is six-membered. The reasons for the much larger interaction between two allylic radicals through the bonds of the four-membered ring in 2c than through the bonds of the five-membered ring in 15 or the six-membered ring in 12b are discussed, and the consequences of the large, through-bond stabilization of the singlet state of 2c are described. digital.library.unt.edu/ark:/67531/metadc71806/
- Mathematical correlations for describing enthalpies of solvation of organic vapors and gaseous solutes into ionic liquid solvents
- This article discusses the mathematical correlations for describing enthalpies of solvation of organic vapors and gaseous solutes into ionic liquid solvents. Abstract: Previously reported ion-specific equation coefficients for the Abraham general solvation model are updated using recently published enthalpy of solution data for organic solutes dissolved in room temperature ionic liquids (RTILs). Reported for the first time are equation coefficients for 1-hexyloxymethyl-3-methylimidazolium, 1,3-dihexyloxymethylimidazolium, 3-methyl-N-butylpyridinium, tris(pentafluoroethyl)trifluoro phosphate, and tetracyanoborate ions. In total 12 sets of cation-specific and 10 sets of anion-specific equation coefficients have been determined for each model. The derived correlations describe the 942 experimental enthalpies of solvation to within a standard deviation of about 1.65 kJ/mol. digital.library.unt.edu/ark:/67531/metadc155634/
- Accountable Science: The COMPETES Act Needs to Demonstrate an Accountability Attitude
- This article discusses the U.S. National Science Foundation's (NSF) Broader Impacts Merit Review Criterion in relation to the America COMPETES Reauthorization Act of 2010. digital.library.unt.edu/ark:/67531/metadc86163/
- Nikolaikirche and Apotheke zum Bären, Berlin, Germany
- Front cover of volume 100, issue 1 of The Hexagon, featuring the multistory brick and stone church, Nikolaikirche. The church's first several floors are comprised of older stone work while the upper stories use newer red brick. People and vehicles are on the street near the church, and a row of buildings can be seen in the background to the left. The magazine's logo is printed over the church's bluish roof spires. The inside cover contains a table of contents, staff credits, and an editorial. digital.library.unt.edu/ark:/67531/metadc111235/
- Rediscovery of the Elements: The Platinum Metals
- Article describing the history of the platinum metals, from its discovery in the New World and subsequent experiments in Europe. Tourist information is provided regarding areas pertinent to the history of platinum. digital.library.unt.edu/ark:/67531/metadc111236/
- Memory Effects in Fractional Brownian Motion with Hurst Exponent H<1/3
- In this article, the authors study the regression to the origin of a walker driven by dynamically generated fractional Brownian motion (FBM) and the authors prove that when the FBM scaling, i.e., the Hurst exponent H<1/3, the emerging inverse power law is characterized by a power index that is a compelling signature of the infinitely extended memory of the system. Strong memory effects leads to the relation H=θ/2 between the Hurst exponent and the persistent exponent θ, which is different from the widely used relation H=1 - θ. The latter is valid for 1/3<H<1 and is known to be compatible with the renewal assumption. digital.library.unt.edu/ark:/67531/metadc40405/
- Experimental Evidence for Heavy-Atom Tunneling in the Ring-Opening of Cyclopropylcarbinyl Radical from Intramolecular 12C/13C Kinetic Isotope Effects
- This article discusses experimental evidence for heavy-atom tunneling. Abstract: The intramolecular 13C kinetic isotope effects for the ring-opening of cyclopropylcarbinyl radical were determined over a broad temperature range. The observed isotope effects are unprecedentedly large, ranging from 1.062 at 80 °C to 1.163 at -100 °C. Semiclassical calculations employing canonical variational transition-state theory drastically underpredict the observed isotope effects, but the predicted isotope effects including tunneling by a small-curvature tunneling model match well with experiment. These results and a curvature in the Arrhenius plot of the isotope effects support the recently predicted importance of heavy-atom tunneling in cyclopropylcarbinyl ring-opening. digital.library.unt.edu/ark:/67531/metadc71805/
- Publisher's Note: Beyond the Death of Linear Response: 1/f Optimal Information Transport [Phys. Rev. Lett. 105,040601 (2010)]
- This is a Publisher's Note for the article 'Beyond the Death of Linear Response: 1/f Optimal Information Transport' [Phys. Rev. Lett. 105, 040601 (2010)]. digital.library.unt.edu/ark:/67531/metadc40406/
- Cation-specific and anion-specific Abraham model correlations for solute transfer into ionic liquid solvents
- This article discusses cation-specific and anion-specific Abraham model correlations for solute transfer into ionic liquid solvents. Abstract: Data have been assembled from the published literature on the infinite dilution activity coefficients and gas solubilities of solutes dissolved in ionic liquid (IL) solvents. In total data for more than 1790 solute-IL pairs were compiled. The published experimental data were converted to gas-to-IL and water-to-IL partition coefficients, and correlated with the ion-specific equation coefficient version of the Abraham general solvation model. Ion-specific equation coefficients describe the experimental gas-to-IL and water-to-IL partition coefficient data to within 0.114 and 0.139 log units, respectively. Reported for the first time are equation coefficients for diethylphosphate, tris(pentafluoroethyl)trifluorophosphate and tetracyanoborate anions. digital.library.unt.edu/ark:/67531/metadc152450/
- Formation and characterization of ion beam assisted nanosystems in silicon
- This article discusses formation and characterization of ion beam assisted nanosystems in silicon. Abstract: Even though silicon is optically inactive, the nanoscale particle structures (e.g. SiC) in Si or silica matrices are potential candidates for light emitting solid state device applications with higher operation temperatures. The synthesis of these nanostructures involves ion implantation and subsequent thermal annealing. The film thickness and sizes of the nanostructures can be controlled by ion energy, fluence, and annealing conditions. Particle accelerator based characterization was used at different stages of formation and analysis of these nanosystems in Si. Results will be presented using infrared spectroscopy (IR), X-ray diffraction spectroscopy (XRD), and photoluminescence (PL) spectroscopy. digital.library.unt.edu/ark:/67531/metadc139470/
- Flavin-Catalyzed Insertion of Oxygen into Rhenium-Methyl Bonds
- This article discusses flavin-catalyzed insertion of oxygen into rhenium-methyl bonds. Abstract: Flavins and related molecules catalyze organic Baeyer-Villiger reactions. Combined experimental and DFT studies indicate that these molecules also catalyze the insertion of oxygen into metal-carbon bonds through a Baeyer-Villiger-like transition state. digital.library.unt.edu/ark:/67531/metadc107791/
- Beyond the Death of Linear Response: 1/f Optimal Information Transport
- This article discusses linear response and 1/f optimal information transport. Article: Nonergodic renewal processes have recently been shown by several authors to be insensitive to periodic perturbations, thereby apparently sanctioning the death of linear response, a building block of nonequilibrium statistical physics. The authors show that it is possible to go beyond the "death of linear response" and establish a permanent correlation between an external stimulus and the response of a complex network generating nonergodic renewal processes, by taking as stimulus a similar nonergodic process. The ideal condition of 1/f noise corresponds to a singularity that is expected to be relevant in several experimental conditions. digital.library.unt.edu/ark:/67531/metadc40407/
- Computational criteria for establishing reflex from plasticity to hardwiring
- This article accompanies a poster presentation on computational criteria for establishing reflex from plasticity to hardwiring. The role of synaptic plasticity in associative learning has been explored extensively computationally. Yet, the computational mechanism for hardwiring of the neural circuit has only been addressed recently using a systems approach of whole-animal behavior based on an evolutionary process for survival. In this paper, the authors will explore the computational criteria needed to establish the hardwiring of reflex. digital.library.unt.edu/ark:/67531/metadc122150/
- Analytical solutions for a two-level system driven by a class of chirped pulses
- In this article, the authors present analytical solutions for the problem of a two-level atom driven by a class of chirped pulses. The solutions are given in terms of Heun functions. By use of the appropriate chirping parameters, an enhancement of four orders of magnitude in the population transfer is obtained. digital.library.unt.edu/ark:/67531/metadc103257/
- Media and Communication
- This book chapter discusses media and communication. Language is commonly singled out as the essence of humanity (Cassirer 1925). Human beings are co-creators, because they give names to the plants and animals. They invent symbols to represent things in their world, which allows them to share the contents of their minds with one another. Thus, as linguistic creatures, humans are also inherently social, because they inhabit a shared symbolic order made possible by their powers of representation and communication. And because of this pervasive character of communication in the development of the human species, media and communication studies have not been contained in an explicit discipline, with its own subject matter. Interdisciplinarity has been essential for understanding it. digital.library.unt.edu/ark:/67531/metadc81385/
- Temporal associative memory (TAM) by spike-timing dependent plasticity
- This article accompanies a poster presentation on temporal associative memory (TAM). Spike-timing synaptic plasticity (STDP) describes the increase and decrease in synaptic strength depending on the relative arrival time of the pre- and post-synaptic spikes. The relative timing that determines whether the synapse is strengthened by long-term potentiation (LTP), or weakened by long-term depression (LTD) was first reported experimentally and computationally. Because of the asymmetry in timing, it is also called "temporally asymmetric Hebbian plasticity" theoretically. Numerous studies on STDP had explored the biological mechanisms for induction of LTP and LTD. This paper will focus on the computational function of STDP in the formation of temporal associative memory (TAM). digital.library.unt.edu/ark:/67531/metadc122149/
- Variables governing emotion and decision-making: human objectivity underlying its subjective perception
- This article accompanies a poster presentation on the variables governing emotion and decision-making. Although decision-making is a logical reasoning process, it is often influenced by the underlying emotions at the moment of decision. The ability to recognize one's emotion and assess one's judgement in order to make a prudent decision is called "emotional intelligence." Yet, the definition and role of emotion played in these cognitive processes are often controversial in the psychological field. The authors have derived an objective model of emotion based on biological evolutionary principles and engineering principles that uses a computational approach to address the role of emotions played in animals. digital.library.unt.edu/ark:/67531/metadc122151/
- Ultradispersive adaptive prism based on a coherently prepared atomic medium
- In this article, the authors have experimentally demonstrated an ultra-dispersive optical prism made from a coherently driven Rb atomic vapor. The prism possesses spectral angular dispersion that is 6 orders of magnitude higher than that of a prism made of optical glass; such angular dispersion allows one to spatially resolve light beams with different frequencies separated by a few kilohertz. The prism operates near the resonant frequency of atomic vapor and its dispersion is optically controlled by a coherent driving field. digital.library.unt.edu/ark:/67531/metadc103269/
- Calculations Predict That Carbon Tunneling Allows the Degenerate Cope Rearrangement of Semibullvalene to Occur Rapidly at Cryogenic Temperatures
- This article discusses carbon tunneling. Abstract: Calculations on the role of tunneling in the degenerate Cope rearrangements of semibullvalene (1) and barbaralane (3) predict that, at temperatures below 40 K, tunneling from the lowest vibrational level should make the temperature-independent rate constants k = 1.43 x 10(-3) s(-1) and k = 7.28 x 10(-9) s(-1), respectively. An experiment, using semibullvalene-2(4)-d1, is proposed to test the prediction of rapid tunneling by 1 at cryogenic temperatures. digital.library.unt.edu/ark:/67531/metadc71814/
- Templated Growth of Hexagonal Nickel Carbide Nanocrystals on Vertically Aligned Carbon Nanotubes
- This article discusses hexagonal nickel carbide. Nanocrystals of hexagonal nickel carbide have been synthesized via physical vapor deposition of elemental nickel onto the surface of vertically aligned carbon nanotubes. Combining high-resolution transmission electron microscopy (HRTEM) with three-dimensional atom probe tomography (3DAP) confirmed that these nanocrystals have a hexagonal structure, are enriched in carbon, and have a composition of ~Ni-25 at. % C (Ni3C). This metastable hexagonal nickel carbide phase appears to be stabilized due to the growth of the nanocrystals on the surface of the nanotubes that act as a template and also as a source of carbon. The stability of this nickel carbide phase has also been investigated by density functional theory (DFT) calculations and compared to the experimental results. digital.library.unt.edu/ark:/67531/metadc71810/
- Femtosecond wave-packet dynamics in cesium dimers studied through controlled stimulated emission
- This article discusses femtosecond wave-packet dynamics in cesium dimers studied through controlled stimulated emission. Abstract: We study the dynamics of wave packets in cesium dimers using a femtosecond-controlled pump-probe technique. We implement configurations with one pulse (pump) or two pulses (pump to control) to produce vibrational wave packets on the electronic excited state. The transmission of an additional, variable-delay probe pulse is measured to monitor the time evolution of the wave packets. In the case of the pump-control-probe configuration, a superposition of two independent wave packets is observed. In order to elucidate the observed experimental data, we develop a theory based on the Liouville equation for the density matrix associated with the Franck-Condon factors. Both the numerical and analytical calculations are in good agreement with our experimental results. digital.library.unt.edu/ark:/67531/metadc103267/
- [Review] Computational Inorganic and Bioinorganic Chemistry
- This book review discusses 'Computational Inorganic and Bioinorganic Chemistry', edited by Edward I. Solomon from Stanford University, Robert A. Scott from the University of Georgia Athens, and R. Bruce King from the University of Georgia Athens. digital.library.unt.edu/ark:/67531/metadc107784/
- Probability flux as a method for detecting scaling
- In this article, the authors introduce a new method for detecting scaling in time series. The method uses the properties of the probability flux for stochastic self-affine processes and is called the 'probability flux analysis' (PFA). The advantages of this method are: 1) it is independent of the finiteness of the moments of the self-affine process; 2) it does not require a binning procedure for numerical evaluation of the probability density function. These properties make the method particularly efficient for heavy tailed distributions in which the variance is not finite, for example, in Lévy α-stable processes. This utility is established using a comparison with the 'diffusion entropy' (DE) method. digital.library.unt.edu/ark:/67531/metadc132978/
- Coherent excitation of a two-level atom driven by a far-off-resonant classical field: Analytical solutions
- This article discusses the coherent excitation of a two-level atom driven by a far-off-resonant classical field. Abstract: We present an analytical treatment of coherent excitation of a two-level atom driven by a far-off-resonant classical field. A class of pulse envelope is obtained for which this problem is exactly solvable. The solutions are given in terms of the Heun function, which is a generalization of the hypergeometric function. Degeneracy of the Heun to a hypergeometric equation can give all the exactly solvable pulse shapes of Gauss hypergeometric form from the generalized pulse shape obtained here. We discuss the application of the results obtained to the generation of soft x-ray and ultraviolet radiations. digital.library.unt.edu/ark:/67531/metadc103262/
- Biocultural conservation in Cape Horn: the Magellanic woodpecker as a charismatic species
- This book chapter discusses a research project to promote biocultural conservation in Cape Horn, Chile. At the southernmost tip of the Americas, the Cape Horn Biosphere Reserve (CHBR) encompasses one of the world's most pristine remaining wilderness areas and is home to the indigenous Yaghan (or Yamana) community, which featured prominently in Charles Darwin's 'Voyage of the Beagle'. Its remoteness and uniqueness, however, are threatened by the introduction of exotic species such as the North American beaver and American mink, increasing development pressures from new connectivity, resource exploitation, and the development of tourism. To implement the biosphere reserve and conserve its natural and cultural richness requires the active participation of the community, as well as linkages and integration between various disciplines and institutions. In an effort to achieve the goal of transdisciplinary integration, the authors used the strategy of identifying a charismatic species, since doing so serves to motivate people towards biodiversity conservation, to communicate ecological concepts, and to integrate both the ecological and social dimensions of sustainability. This study was developed together with the population of Puerto Williams, a town with 2200 inhabitants located on Navarino Island, and the largest human settlement within the CHBR. digital.library.unt.edu/ark:/67531/metadc97940/
- Modified embedded atom method study of the mechanical properties of carbon nanotube reinforced nickel composites
- In this article, the authors report an atomistic simulation study of the behavior of nanocomposite materials that are formed by incorporating single-walled carbon nanotubes (SWCNTs), with three different diameters, and a multiwalled carbon nanotube (MWCNT) into a single-crystal nickel matrix. The interactions between carbon and nickel atoms are described by a modified embedded atom method potential. Mechanical properties of these nanocomposite materials are predicted by atomistic calculations and compared with that of fcc nickel and pristine CNTs. The authors' simulations predict that all Ni/CNT composites studied in this work are mechanically stable. Their elastic properties depend on the volume fraction and diameter of embedded CNTs. The single-crystal Young's modulus (E₁₁) of Ni/SWCNT composites exhibit a large increase in the direction of CNTs alignment compared to that of a single-crystal nickel. However, a moderate but gradual decrease is seen for E₂₂ and E₃₃ in the transverse directions with increase in CNT diameters. As a consequence, Ni/SWCNTs show a gradual decrease for the polycrystalline Young's, bulk and shear moduli with the increasing CNT diameters and volume fractions. These reductions, although moderate, suggest that enhancement of mechanical properties for polycrystalline Ni/SWCNT nanocomposites are not achievable at any CNT volume fraction. The Ni/MWCNT composite with high CNT volume fraction shows the highest increase in E₁₁. Unlike the E₂₂ and E₃₃ for Ni/SWCNTs, there is a significant increase in the E₂₂ and the E₃₃ for Ni/MWCNT. As a result, polycrystalline Ni/MWCNT composites show slight increase in the elastic properties. This suggests that nickel nanocomposites with enhanced mechanical properties can be fabricated using large volume fractions of larger diameter MWCNTs. Depending on type, alignment and volume fraction, Ni/CNT composites show varying degrees of elastic anisotropy and Poisson's ration compared to pure Ni. Simulation predicts strong adhesion at the Ni/CNT interface and a significant interfacial stress transfer between CNT and Ni matrix. digital.library.unt.edu/ark:/67531/metadc107769/