bluuebunny/crossref_metadata_2025_split huggingface dataset:
Raman investigation of hydrogen-implanted and DC hydrogen-plasma-treated Cz Si wafers
Authors: Saad A. M. 
Published: July 2009

The general goal of this work is to demonstrate that the buried defect layer created by hydrogen implantation can serve as a gettering region for hydrogen introduced from a DC plasma and to study the efficiency of this gettering affected by the implantation regimes. Standard n-type 4.5 Ω⋅cm Cz Si wafers were implanted by hydrogen ions with an energy of 100 keV and different doses of 1 × 1014, 1 × 1015, or 5 × 1015 atoms/cm2 at temperatures of 150, 300, 400, or 500 °C. After implantation, hydrogen was introduced to the wafers from the DC plasma at 150 °C. For a comparative estimation of the hydrogen concentration in the wafers implanted in different regimes Raman spectroscopy was used. The peaks of the Raman spectra associated with molecular hydrogen (H2), vacancy-hydrogen (V–H), and silicon–hydrogen (Si–H) complexes were studied depending on the implantation conditions. It is demonstrated that peaks of Raman spectra depend significantly on the dose and temperature of implantation. This means that the concentration of hydrogen in the wafers could be determined from the concentration and type of defects formed by hydrogen implantation. Maximum peaks associated with H2, Si–H, and V–H complexes were observed for the samples implanted at a temperature of 500 °C.
Fracture network analysis of the St-Eustache quarry, Quebec, Canada, for groundwater resources management
Authors: Lemieux Jean-Michel , Kirkwood Donna , Therrien René 
Published: July 2009

A detailed structural survey has been conducted on a fractured sedimentary rock formation in the St-Eustache quarry, Quebec, Canada, to supplement a hydrogeological study. The two main types of discontinuities in the quarry are horizontal bedding planes and vertical joints. The fracture network is classified as a stratabound network that could be considered as an equivalent porous medium (EPM) for groundwater flow for a volume of rock of 25 to 100 m3. Using detailed statistical data of the fracture network, a geometric model is used to infer a range of hydraulic conductivity values for the low permeability fractures not directly measured with hydraulic tests and treated as EPM for their interpretation. This analysis shows that the vertical and horizontal fractures have about the same permeability in the rock mass, except for a few high hydraulic-conductivity bedding planes. Hydraulic conductivity of single fractures ranges between 1.7 × 10−3and 1.7 × 10−1m/s. The porosity of the bulk rock mass inferred from fracture spacing measurements was found to be between 0.03% and 0.3%. Because vertical boreholes provide limited information on vertical fractures, the interpretation of hydraulic tests at the site was greatly improved by the structural surveys.
Combined tight-binding/DFT investigation of the electronic structure of triimine-platinum(II)/TCNQ extended stacks,
Authors: Rabaâ Hassan , Cundari Thomas R. , Omary Mohammad A. 
Published: July 2009

. The [Pt(tbtrpy)(X)][TCNQ] (X = OH or SH) complexes form sandwich stacks with nitrile acceptors leading to extended-chain supramolecular assemblies, tbtrpy = 4,4′,4″-tert-Bu3-2,2′:6′,2″-terpyridine. Calculations with the extended Hückel tight-binding (EHTB) method are performed upon crystalline {[Pt (tbtrpy)(X)][TCNQ]}∞ species to analyze their electronic structure and consequent properties, TCNQ = 7,7,8,8-tetracyanoquinodimethane. The donor/acceptor extended chains in the solid state are predicted to exhibit metallic behavior with a large contribution from π and π* bands of TCNQ to the valence and conduction bands, respectively. Moreover, the valence band moves upward (i.e., to a less negative energy) for X = SH as compared to X = OH. Density functional theory (DFT) calculations suggest that this is due to large thiolate character in the HOMO of the square-planar donor complex, which also supports the experimental assignment of the electronic absorption bands and redox potentials. Calculations of infrared (νCN bands of TCNQ) and structural (CC bond lengths within TCNQ) data explain the metallic behavior of the stacks in terms of charge delocalization, leading to fractionally-charged species of the form [Pt(tbtrpy)X](1+δ)+[TCNQ](1+δ)- with δ > 0 and a greater δ value for X = SH vs OH.
Competition between mixing and segregation in bimetallic AgnRbnclusters (n= 2–10),
Authors: Fournier René , Zamiruddin Shaima , Zhang Min 
Published: July 2009

We found the minimum-energy structures of AgnRbn(n = 2–10) clusters by a combination of density functional theory (DFT) and taboo search global optimization. The global minimum geometry is mixed for n ≤ 4 and segregated, with a core-shell arrangement, for n > 4. There is a change in the nature of the bonding, from ionic to metallic, between n = 4 and n = 5. Although metallic bonding dominates at n > 4, large atomic charges (in the order of ±0.5) persist. These atomic charges (negative on the interior Ag atoms, positive on the surface Rb atoms) make AgnRbnclusters analogous to Zintl compounds and could prevent them from coalescing. This makes them intriguing potential building blocks for cluster-assembled materials. Ag4Rb4is relatively stable compared with other AgnRbnclusters; it has a nearly cubic shape, a large HOMO–LUMO gap (2 eV), and a highly ionic character with atomic charges equal to roughly ±1 au.
A time-dependent density functional theory (TDDFT) interpretation of the optical spectra of zinc phthalocyanine π-cation and π-anion radicals
Authors: Rosa Angela , Ricciardi Giampaolo 
Published: July 2009

The UV–visible and near-IR spectra of the zinc phthalocyanine π-cation and π-anion radicals, [ZnPc(–1)]•+ and [ZnPc(–3)]•–, are investigated by time-dependent density functional theory (TDDFT) calculations using the pure, asymptotically correct, statistical average of (model) orbital potentials (SAOP) functional. The nature and intensity of the main spectral features are highlighted and interpreted on the basis of the ground-state electronic structure of the complexes. Similarities and differences with previous TDDFT/B3LYP results are discussed. TDDFT/SAOP results for the π-anion radical prove to be in excellent agreement with the solution spectra and generally in line with deconvolution analyses of solution absorption and magnetic circular dichroism (MCD) spectra. On the basis of these results a novel interpretation of the Q-band system is proposed. For the π-cation radical TDDFT/SAOP calculations provide a satisfactory description of the UV region of the spectrum. However, they do not reproduce accurately the energy and intensity of the Q band observed at 825 nm. The description of the Q-band region appears to be complicated by the presence of spurious non-Gouterman transitions. Furthermore, the calculations, either in the gas phase or in solution, do not account for the broad absorption near 500 nm that has been suggested to arise from a nondegenerate, z-polarized 2A2g excited state. Theory and experiment can be reconciled if the presence of an axial ligand such as CN– is explicitly considered in the calculations. TDDFT/SAOP results for the axially ligated [ZnPc(–1)(CN)]• species indicate that the 500 nm feature is related to the axial ligation induced symmetry lowering of the π-cation radical and this band is assigned to a z-polarized transition associated with the hole in the 2a1u.
Nonlinear time-dependent density functional theory studies of the ionization of CO2 by ultrashort intense laser pulses
Authors: Fowe Emmanuel Penka , Bandrauk André Dieter 
Published: July 2009

Time-dependent density functional theory (TDDFT) studies of the ionization of CO2 by intense laser pulses (3.50 × 1014, 1.40 × 1015, 2.99 × 1015, and 1.25 × 1016 W/cm2) at 800 nm (ω = 0.0584 au) are presented in the nonlinear nonpertubative regime. Special emphasis is placed on elucidating molecular orbital orientation and various peak-intensities effects on the ionization processes. The results reveal that molecular orbital ionizations are strongly sensitive to their symmetry and the laser intensities. Most notably, we found that with a proper choice of the laser intensity (3.5 × 1014 W/cm2), the sensitivity is strong enough such that the nature and symmetry of the highest occupied molecular orbital (HOMO) can be directly probed and visualized from the angular dependence of laser-induced ionization. At higher intensities, ionization is found to occur also from inner orbitals, thus complicating the imaging of simple orbitals. A time-dependent electron-localization function (TDELF) is used to get a visual insight on the time evolution process of the electron density.
Impacts of repeated fertilization on fine roots, mycorrhizas, mesofauna, and soil chemistry under young interior spruce in central British Columbia
Authors: Berch Shannon M. , Brockley Robert P. , Battigelli Jeff , Hagerman Shannon 
Published: July 2009

We assessed soil biota and soil chemistry in a 20-year-old interior spruce ( Picea glauca × engelmannii) stand in the interior of British Columbia 10 years after initiation of annual fertilization. Treatments included an unfertilized control, ON1 (having received per hectare 800 kg nitrogen (N), 350 kg phosphorus (P), 400 kg potassium (K)), and ON2 (having received per hectare 1400 kg N, 350 kg P, 400 kg K). Micronutrients were added periodically. There was more mineralizable N and NO3-N in the forest floor and upper mineral soil of ON2 plots than in the controls or ON1. Forest floor NH4-N increased with each level of fertilizer application. Total forest floor N, total sulphur, and exchangeable magnesium were higher with both levels of fertilization than with the unfertilized control. For the forest floor, available P and exchangeable K were highest in ON1. Forest floor densities of Acari, Prostigmata, and Oribatida were greater in fertilized plots than unfertilized control plots. In mineral soil, only Oribatida increased significantly with fertilization. Fertilization increased fine root length in ON1 relative to the control and ON2, but ectomycorrhizal colonization did not differ among treatments. These results contrast with previously reported responses to similar fertilizer treatments under lodgepole pine ( Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) in which negative responses of fine roots and soil biota to repeated nutrient additions were observed.
The influence of riparian vegetation on leaf litter inputs to Boreal Shield streams: implications for partial-harvest logging in riparian reserves
Authors: Muto Elisa A. , Kreutzweiser David P. , Sibley Paul K. 
Published: July 2009

Litter inputs to headwater streams were measured to characterize and describe input patterns to the streams and to quantify the relationships between leaf litter inputs and surrounding riparian characteristics in Boreal Shield forests. Our goal was to provide information on litter inputs to streams in the Boreal Shield to determine if partial-harvest logging of commercial trees within riparian reserves has the potential to cause significant changes to litter inputs. Total leaf litter comprised 87% deciduous leaves and 13% conifer needles during the June to October periods. Commercial deciduous tree species accounted for approximately 50% of total deciduous leaf litter inputs. Distance-weighted deciduous basal area was the best predictor of overstorey deciduous litter (r2 = 0.597, P = <0.001), indicating that the size, abundance, and proximity of deciduous trees to streams are important to deciduous litter inputs. Leaf litter inputs to Boreal Shield streams are strongly influenced by surrounding riparian vegetation and can be effectively predicted by stem basal area. A linear regression model based on commercial deciduous tree basal area is presented that can be useful to determine the number of trees to retain within a riparian area to maintain leaf litter inputs at or near preharvest levels.
Variation in foliar nitrogen and aboveground net primary production in young postfire lodgepole pine
Authors: Turner Monica G. , Smithwick Erica A.H. , Tinker Daniel B. , Romme William H. 
Published: July 2009

Understanding nutrient dynamics of young postfire forests may yield important insights about how stands develop following stand-replacing wildfires. We studied 15-year-old lodgepole pine stands that regenerated naturally following the 1988 Yellowstone fires to address two questions: (1) How do foliar nitrogen (N) concentration and total foliar N vary with lodgepole pine density and aboveground net primary production? (2) Is foliar N related to litter production and to rates of gross production, consumption, and net production of soil NH4+ and NO3–? Foliar N concentration of new lodgepole pine needles averaged 1.38%; only stands at very high density (>80 000 trees·ha–1) approached moderate N limitation. Foliar N concentration in composite (all-age) needles averaged 1.08%, varied among stands (0.87%–1.39%), and declined with increasing tree density. The foliar N pool averaged 48.3 kg N·ha–1, varied among stands (3.6–218.4 kg N·ha–1), and increased with aboveground net primary production. Total foliar N was not related to laboratory estimates of net production of NH4+ or NO3– in soils. Lodgepole pine foliage is a strong N sink, and N does not appear to be limiting at this early successional state. The initial spatial patterns of postfire tree density strongly influence landscape patterns of N storage.
Site carbon storage along productivity gradients of a late-seral southern boreal forest
Authors: Kranabetter J.M. 
Published: July 2009

The quantity and distribution of carbon (C) storage in old-growth forests is a fundamental parameter needed to more accurately predict management effects on landscape C. C accounting on a regional or national level is generally based on zonal ecosystems, but total ecosystem C can vary widely with soil productive capacity within landscapes. To illustrate this, I compared old-growth forests of contrasting plant associations reflecting typical soil productivity gradients of the southern boreal forest in British Columbia, Canada. Total ecosystem C of zonal sites (medium–Huckleberry plant association) averaged 309 Mg C·ha–1, while less and more productive forest types ranged from 120 to 725 Mg C·ha–1, respectively. On average, 62% of ecosystem C was in live trees, 20% in mineral soils (0–50 cm), 9% in forest floors, and 9% in coarse woody debris and snags. Positive linear correlations between total ecosystem C and soil nitrogen availability or asymptotic stand height confirmed the strong influence of site productive capacity on C storage. The results demonstrate how ecological site classification or direct measures of stand productivity could refine estimates of the upper limits in potential C storage.
Chapter 3 Analysis Tools
Authors: Ping Rong-Gang , Mo X. H. , Fu C. D. , He K. L. , Hu J. F. , Huang B. , Qin G. , Sun S. S. , Zheng Y. H. , Liu Beijiang , Xu Min , Zhang Xueyao , Wu Ning , Zheng Hanqing , Asner David 
Published: July 2009

The following sections are included: Monte Carlo Generators Luminosity Measurements at BES-III Particle Identification Kinematic Fitting Partial Wave Analysis Dalitz-Plot Analysis Formalism
Workshop on modeling in software engineering at ICSE 2009
Authors: Baillargeon Robert , France Robert , Zschaler Steffen , Rumpe Bernhard , Völkel Steven , Georg Geri 
Published: July 2009

The Modeling in Software Engineering (MiSE) workshop series provides a forum for discussing the challenges associated with modeling software and with incorporating modeling practices into the software development process. The main goal of the series is to further promote cross-fertilization between the modeling communities (e.g., MODELS) and software-engineering communities.
In particular, the workshop provides a medium to exchange innovative technical ideas and experiences related to modeling. The 2009 MiSE workshop provided a venue for presentation and discussion of eleven papers in the five areas of model evolution, domain specific languages, verification and validation, model transformation and state-of-the-art modeling usage in software development. These papers represent a 44% acceptance rate to the workshop. Three posters were also accepted. This report summarizes the discussions and conclusions of the workshop.
MemTracker
Authors: Venkataramani Guru , Doudalis Ioannis , Solihin Yan , Prvulovic Milos 
Published: July 2009

Memory bugs are a broad class of bugs that is becoming increasingly common with increasing software complexity, and many of these bugs are also security vulnerabilities. Existing software and hardware approaches for finding and identifying memory bugs have a number of drawbacks including considerable performance overheads, target only a specific type of bug, implementation cost, and inefficient use of computational resources.
This article describes MemTracker, a new hardware support mechanism that can be configured to perform different kinds of memory access monitoring tasks. MemTracker associates each word of data in memory with a few bits of state, and uses a programmable state transition table to react to different events that can affect this state. The number of state bits per word, the events to which MemTracker reacts, and the transition table are all fully programmable. MemTracker's rich set of states, events, and transitions can be used to implement different monitoring and debugging checkers with minimal performance overheads, even when frequent state updates are needed. To evaluate MemTracker, we map three different checkers onto it, as well as a checker that combines all three. For the most demanding (combined) checker with 8 bits state per memory word, we observe performance overheads of only around 3%, on average, and 14.5% worst-case across different benchmark suites. Such low overheads allow continuous (always-on) use of MemTracker-enabled checkers, even in production runs.
An interview with John H. Holland
Authors: Booker Lashon B. 
Published: July 2009

John Holland began his academic career as a graduate student at the University of Michigan studying with Arthur Burks, a designer of early programmable computers and colleague of John von Neumann. Under Burks' supervision, in 1959 Holland received what may have been the first Ph.D. in the world in the emerging field of computer science. He was subsequently hired as one of the first professors in the new department of Computer and Communication Science at the University of Michigan.
As the inventor of genetic algorithms, John established himself as one of the early pioneers in understanding the foundations of adaptation, learning, and modeling in both natural and artificial systems. His extensions of the genetic algorithm, first to a cognitive architecture called classifier systems and later to an ecological architecture known as Echo, have increased the reach of his ideas well beyond computer science. John Holland's imaginative, interdisciplinary approach to thinking about adaptation, emergence and complexity has made him one of the world's acknowledged leaders in the field of complex adaptive systems. In addition to his many intellectual achievements, John Holland has also been a valued mentor and friend for those of us who have had the privilege to be his students.
Holland is currently a Professor of Psychology and Professor of Electrical Engineering & Computer Science at the University of Michigan. He is also a member of the Board of Trustees and an External Professor at the Santa Fe Institute. Holland was made a MacArthur Fellow in 1992 and is a Fellow of the World Economic Forum.
Analysis of the Human Cancer Glycome Identifies a Novel Group of Tumor-AssociatedN-Acetylglucosamine Glycan Antigens
Authors: Satomaa Tero , Heiskanen Annamari , Leonardsson Iréne , Ångström Jonas , Olonen Anne , Blomqvist Maria , Salovuori Noora , Haglund Caj , Teneberg Susann , Natunen Jari , Carpén Olli , Saarinen Juhani 
Published: July 2009

AbstractThe cell surface is covered by a dense layer of protein- and lipid-linked glycans. Although it has been known that distinct glycan structures are associated with cancer, the whole spectrum of cancer-associated glycans has remained undiscovered. In the present study, we analyzed the protein-linked cancer glycome by matrix-assisted laser desorption/ionization time-of-flight mass spectrometric glycan profiling of cancer patient tissue samples. In lung cancer, we detected accumulation of a novel group of tumor-associated glycans. These protein-linked glycans carried abnormal nonreducing terminal β-N-acetyl-d-glucosamine (GlcNAc) residues. A similar phenomenon was also detected in structural analyses of tumor-derived glycosphingolipids. This showed that glycan biosynthesis may dramatically change in cancer and that direct glycome analysis can detect the resulting marker glycans. Based on the structural knowledge, we further devised a covalent labeling technique for the detection of GlcNAc-expressing tumors with a specific transferase enzyme. In normal tissues, terminal GlcNAc antigens are capped by galactosylation. Similarly to common cancer-associated glycan antigens T, Tn, and sialyl-Tn, the newly discovered GlcNAc antigens result from incomplete glycosylation. In conclusion, the identified terminal GlcNAc glycans should be recognized as a novel class of tumor markers. [Cancer Res 2009;69(14):5811–9]
Expression of an Exogenous Human Oct-4 Promoter Identifies Tumor-Initiating Cells in Osteosarcoma
Authors: Levings Padraic P. , McGarry Sean V. , Currie Thomas P. , Nickerson David M. , McClellan Steven , Ghivizzani Steven C. , Steindler Dennis A. , Gibbs C. Parker 
Published: July 2009

Abstract
We explored the nature of the tumor-initiating cell in osteosarcoma, a bone malignancy that predominately occurs in children. Previously, we observed expression of Oct-4, an embryonal transcriptional regulator, in osteosarcoma cell cultures and tissues. To examine the relationship between Oct-4 and tumorigenesis, cells from an osteosarcoma biopsy (OS521) were stably transfected with a plasmid containing the human Oct-4 promoter driving a green fluorescent protein (GFP) reporter to generate the transgenic line OS521Oct-4p. In culture, only ∼24% of the OS521Oct-4p cells were capable of activating the transgenic Oct-4 promoter; yet, xenograft tumors generated in NOD/SCID mice contained ∼67% GFP+ cells, which selectively expressed the mesenchymal stem cell–associated surface antigens CD105 and ICAM-1. Comparison of the tumor-forming capacity of GFP-enriched and GFP-depleted cell fractions revealed that the GFP-enriched fractions were at least 100-fold more tumorigenic, capable of forming tumors at doses of &lt;300 cells, and formed metastases in the lung. Clonal populations derived from a single Oct-4/GFP+ cell were capable of forming tumors heterogeneous for Oct-4/GFP expression. These data are consistent with the cancer stem cell model of tumorigenesis in osteosarcoma and implicate a functional link between the capacity to activate an exogenous Oct-4 promoter and tumor formation. This osteosarcoma tumor-initiating cell appears highly prolific and constitutes a majority of the cell population in a primary xenograft tumor, which may provide a biological basis for the particular virulence of this type of cancer. [Cancer Res 2009;69(14):5648–55]