bluuebunny/crossref_metadata_2025_split huggingface dataset:
An efficient metaheuristic for integrated scheduling and staffing IT projects based on a generalized minimum cost flow network
Authors: Kolisch Rainer , Heimerl Christian 
Published: February 2012

AbstractScheduling IT projects and assigning the project work to human resources are an important and common tasks in almost any IT service company. It is particularly complex because human resources usually have multiple skills. Up to now only little work has considered IT‐specific properties of the project structure and human resources. In this article, we present an optimization model that simultaneously schedules the activities of multiple IT projects with serial network structures and assigns the project work to multiskilled internal and external human resources with different efficiencies. The goal is to minimize costs. We introduce a metaheuristic that decomposes the problem into a binary scheduling problem and a continuous staffing problem where the latter is solved efficiently by exploiting its underlying network structure. For comparison, we solve the mixed–binary linear program with a state–of–the–art commercial solver. The impacts of problem parameters on computation time and solution gaps between the metaheuristic and the solver are assessed in an experimental study. Our results show that the metaheuristic provides very favorable results in considerable less time than the solver for midsize problems. For larger problems, it shows a similar performance while the solver fails to return feasible solutions. © 2012 Wiley Periodicals, Inc. Naval Research Logistics 59: 111–127, 2012
Preparation of inner asymmetric composite microspheres
Authors: Zhang Hepeng , Zhang Qiuyu , Zhang Baoliang , Xu Hailong , Fan Xinlong 
Published: February 2012

AbstractNovel inner asymmetric composite microspheres were prepared by encapsulating surface‐modified magnetic particles via mini‐emulsion polymerization. Most of the surface‐modified magnetic particles encapsulated into the polymer matrix aggregate in one side of each microsphere, while only a few particles randomly disperse in the remaining part. The magnetic content of these novel asymmetric composite microspheres is 46.7% and the saturation magnetization is 23.8 emu g−1. Copyright © 2012 Society of Chemical Industry
Synthesis of well‐defined poly(dimethylsiloxane) telechelics having nitrobenzoxadiazole fluorescent chain‐ends via thiol‐ene coupling
Authors: Cohen Céline , Damiron Denis , Dkhil Sadok Ben , Drockenmuller Eric , Restagno Frédéric , Léger Liliane 
Published: February 2012

AbstractWell‐defined PDMS telechelics having nitrobenzoxadiazole (NBD) fluorescent probes covalently attached at both chain‐ends were prepared in two steps and a series of fractionation procedures starting from commercially available divinyl‐terminated PDMS having a broad molar mass dispersity. First, thiol‐ene coupling between 6‐mercapto‐1‐hexanol and vinyl chain‐ends allowed the formation of dihydroxy‐terminated PDMS telechelics through the formation of a thioether linkage. The resulting material was then sequentially fractionated using dichloromethane/methanol mixtures to afford several well‐defined dihydroxy‐terminated PDMS fractions having sharp distributions of molar masses (Mn = 99.5–158 kDa and Đ < 1.2). The NBD fluorescent probes were then attached at both chain‐ends by N,N′‐dicyclohexylcarbodiimide/4‐(dimethylamino)pyridine esterification coupling between the hydroxyl groups and 6‐(7‐nitrobenzofurazan‐4‐ylamino)hexanoic acid. The resulting fluorescent PDMS telechelics were characterized by SEC, 1H NMR, UV–visible, and fluorescence spectroscopies. These materials are suitable probes to investigate the dynamics of polymer chains in bulk or at interfaces by the fringe pattern fluorescent recovery after photobleaching technique. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Effects of humidity on the electrical characteristics of ZnO nanowire devices
Authors: Kim J. , Jeong H. S. , Ahn Y. H. , Lee S. , Park J.‐Y. 
Published: February 2012

AbstractChanges in the electrical characteristics of individual ZnO nanowire (NW) devices when they are exposed to wet air (80% relative humidity, RH) at room temperature are investigated. Significant roughening on the surface of ZnO NWs is observed after they are exposed to wet air for more than tens of hours. I–V characteristics taken after exposure to humidity show positive shifts of the threshold voltages in ZnO NW field effect transistors (FETs), which indicate depletion of carriers. These results have implication about the long‐term stability of such devices when they need to be in direct contact with the ambient environment for their operations. magnified image
Surface roughening on a ZnO NW due to exposure to humidity (left) and corresponding changes in transfer characteristics of the device with its exposure time to humidity (right).
Texture‐etched ZnO as a versatile base for optical back reflectors with well‐designed surface morphologies for application in thin film solar cells
Authors: Böttler W. , Smirnov V. , Hüpkes J. , Finger F. 
Published: February 2012

AbstractZnO layers with a wide range of surface morphologies were studied for applications in thin film silicon solar cells. The texture of ZnO layers, achieved by chemical etching, was measured by atomic force microscopy (AFM) and statistically analyzed in terms of the roughness, the crater depth, the crater diameter, and the crater opening angle. We present a method to independently tune the lateral and vertical dimensions of the etched crater structures by combined variations of ZnO layer thickness and etching time. The optical scattering properties of the textured ZnO layers are investigated. The effects of these morphologies on the performance of the solar cells, prepared in both p–i–n and n–i–p configurations are analyzed. For the latter cell type the roughness is introduced at the back side, thus the cell does not sense ZnO absorption and conductivity of the different morphologies. The link between the morphology, the optical properties of ZnO layers, and the solar cell performance is discussed.
Density functional theory studies on the addition and abstraction reactions of OH radicals with terephthalate dianions
Authors: Tanaka Nobuaki , Itoh Shigeo , Nishikiori Hiromasa 
Published: February 2012

AbstractThe addition and abstraction reactions of OH radicals with terephthalate dianions are investigated by density functional theory calculations that include solvent effects. Geometry optimizations of the reactants, products, and transition state species are performed for the potential reaction paths. For the addition reactions, those targeting the ipso‐ and ortho‐carbons are predicted to be exoergic. The H‐atom abstraction reaction is also predicted to be exoergic. On the basis of the rate constants calculated by means of the transition state theory, the H‐atom abstraction reaction is determined to be the thermochemically favored path. © 2012 Wiley Periodicals, Inc.
Localized Grounding, Excavation, and Dissection Using In‐Situ Probe Techniques for Focused Ion Beam and Scanning Electron Microscopy: Experiments With Rock Varnish
Authors: Ditto Jeffrey , Krinsley David , Langworthy Kurt 
Published: February 2012

SummaryWhile investigating rock varnish, we explored novel uses for an in‐situ micromanipulator, including charge collection, sample manipulation, as well as digging and dissection at the micron level. Dual‐beam focused ion beam microscopes (DB‐FIB or FIBSEM) equipped with micromanipulators have proven to be valuable tools for material science, semiconductor research, and product failure analysis. Researchers in many other disciplines utilize the DB‐FIB and micromanipulator for site‐specific transmission electron microscope (TEM) foil preparation. We have demonstrated additional applications for in‐situ micromanipulators. SCANNING 34: 279–283, 2012. © 2012 Wiley Periodicals, Inc.
The mortality problem of learning and mimetic practice in emerging industries: Dying to be legitimate
Authors: Miller Justin I. 
Published: February 2012

AbstractThis study seeks to disentangle claims of institutional and organizational learning theories and to shed light on the impact of Knightian (environmental) uncertainty in discovery opportunities. This article suggests, and finds empirical support for, the concept that emerging professional service industries retain high levels of causal ambiguity. High uncertainty interferes with institutional theory's claim of mortality reduction through isomorphism, but leads to superstitious learning, increasing organizational mortality hazard. Education and experience of entrepreneurs help them identify discovery (exogenous) opportunities for entrepreneurial rents, while high (but untheorized) levels of uncertainty interfere in their ability to successfully exploit these same opportunities. Copyright © 2012 Strategic Management Society.
Diogenes, a process for identifying unintended consequences
Authors: Bahill A. Terry 
Published: February 2012

AbstractIndividuals, companies, and even governments often create procedures, processes, or products that solve a particular problem, only to discover that their solution has created a second problem, worse than the first. These secondary problems are called unintended consequences. Searching for unintended consequences, as a part of the development process, will likely increase safety, reduce financial risk, and improve customer satisfaction. This paper contains the design for a new process, named Diogenes, that will help systems engineers identify unintended, but foreseeable, consequences of a new system that is being designed. It contains the required behavior (functions), use cases, design diagrams, the test procedure, validation, and verification for Diogenes. © 2012 Wiley Periodicals, Inc. Syst Eng
Comparison of two different sites of measurement for transabdominal uterine artery Doppler velocimetry at 11–13 weeks
Authors: Lefebvre J. , Demers S. , Bujold E. , Nicolaides K. H. , Girard M. , Brassard N. , Audibert F. 
Published: February 2012

AbstractObjectivesTo compare the feasibility of two transabdominal approaches for performing first‐trimester uterine artery (UtA) Doppler and to evaluate the correlation with pulsatility index (PI) in the second trimester.MethodsThis was a prospective longitudinal Doppler study of the uterine arteries at 11–13 and 21–22 weeks' gestation. Transabdominal ultrasound and color Doppler were used to measure the UtA‐PI of the ascending branch of the uterine artery at the level of the internal cervical os (Site A) and at the level of the apparent crossover with the external iliac artery (Site B) at 11–13 weeks, and at Site B only at 21–22 weeks. In all cases the measured left and right PI were converted to a multiple of the median (MoM) for gestational age, and the intercorrelation between the measurements at different sites and gestational ages was calculated using non‐parametric analysis (Spearman's rank correlation).ResultsSatisfactory measurements were obtained at 11–13 weeks from both uterine arteries in all 81 women at Site A and in 50 (62%; 95% CI, 50–72%) at Site B (P < 0.01). Measurements were obtained at Site B at 21–22 weeks in all cases. In the 50 cases with measurements from both sites at 11–13 weeks, the correlation of PI‐MoMs between Sites A and B at 11–13 weeks was only moderate (ρ = 0.61). The correlation between first‐trimester UtA‐PI MoMs at Site A and second‐trimester UtA‐PI MoMs was stronger than that between first‐trimester UtA‐PI MoMs at Site B and second‐trimester UtA‐PI MoMs (ρ = 0.73 vs ρ = 0.47, P < 0.01).ConclusionEvaluation of UtA‐PI at 11–13 weeks can be achieved at the level of the internal cervical os in a greater proportion of women than at the level of the apparent crossover with the external iliac vessels, and the measurements obtained correlate better with second‐trimester UtA‐PI. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Higher Tool Productivity due to New Generation of PVD Coatings
Authors: Eerden Michiel , Papa Frank , Krug Thomas , Driesenaar Désirée 
Published: February 2012

AbstractPVD coating technology has seen many new developments in the past few years. HIPIMS+ is an example of these developments with excellent results on tool productivity and lifespan. The technology combines the advantages of arc evaporation with those of magnetron sputtering and results in a dense and defect‐free coating with tuneable residual stress. The coatings have been tested successfully by international tool manufacturers. Additional developments can be seen in DLC coatings and the hydrogen‐free variety ta‐C. These coatings are suitable for low temperature deposition and machining of special materials.
Plasmabromierung von graphitischen Materialien
Authors: Friedrich Jörg , Wettmarshausen Sascha , Meyer‐Plath Asmus , Ziemann Sylvia , Hidde Gundula , Zeynalov Eldar 
Published: February 2012

AbstractDie hochselektive und ausbeutereiche plasmachemische Bromierung von Polyolefinoberflächen wurde auf graphitische Materialien übertragen. Oberflächen von graphenartigem Highly Oriented Pyrolytic Graphite (HOPG), natürlichem Graphit, mehrwandige Kohlenstoffnanoröhren (MWCNT) sowie Kohlenstoff‐Fasern wurden im Bromdampfplasma behandelt. Während die Bromierung von Polyolefinoberflächen als radikalische Wasserstoffabstraktion mit nachfolgender Addition (Rekombination) oder durch nucleophile Substitution an sp3‐hybridisierten C‐Atomen abläuft, können graphitische Strukturen sowohl an sp3‐hybridisierten Strukturdefekten als auch durch elektrophile Addition an vollständig C‐substituierte aromatische Doppelbindungen bromiert werden. Dabei werden die planaren (graphitischen) sp2‐C‐Atome in die tetraedrische sp3‐Hybridisierung umgewandelt und zu elektrisch nichtleitenden Strukturen gefaltet.Die maximalen Bromausbeuten bei Verwendung von Brom als Plasmamedium lagen je nach Substrat zwischen 10–50% Br/C, mit Bromoform deutlich darüber, was durch Kombinationen von Bromoform mit Brom oder Allylbromid mit Bromoform durch Schichtbildung auf über 70% Br/C gesteigert werden konnte.An die C‐Br‐Gruppen wurden nasschemisch verschiedene Amine nucleophil gepfropft. Die Pfropfausbeuten von 1–10 Moleküle je 100 C lagen deutlich niedriger als die erreichten Pfropfgrade von etwa 1–22 Moleküle je 100 C‐Atome an Polyolefinoberflächen. Da nach der chemischen Pfropfung nahezu alle nichtgepfropften Br‐Gruppen verschwunden waren, muss auf eine bevorzugte Rekonstruktion der planaren sp2‐Graphitschicht geschlossen werden.
Minimization of the zeroth Neumann eigenvalues with integrable potentials
Authors: Zhang Meirong 
Published: February 2012

For an integrable potential

q

on the unit interval, let

\lambda _{0}(q)

be the zeroth Neumann eigenvalue of the Sturm–Liouville operator with the potential

q

. In this paper we will solve the minimization problem

\tilde{\mathbf{L}}_{1}(r) = \mathrm{\inf }_{q}\:\lambda _{0}(q)

, where potentials

q

have mean value zero and

L^{1}

norm

r

. The final result is

\tilde{\mathbf{L}}_{1}(r) = −r^{2}/ 4

. The approach is a combination of variational method and limiting process, with the help of continuity results of solutions and eigenvalues of linear equations in potentials and in measures with weak topologies. These extremal values can yield optimal estimates on the zeroth Neumann eigenvalues.

Résumé

Soit

\lambda _{0}(q)

la zéro-ème valeur propre de Neumann de lʼopérateur de Sturm–Liouville pour un potentiel intégrable

q

de lʼintervalle

[0,1]

. Dans cet article nous résolvons le problème de minimisation

\tilde{\mathbf{L}}_{1}(r) = \mathrm{\inf }_{q}\:\lambda _{0}(q)

pour les potentiels

q

de valeur moyenne zéro et de norme

L^{1}

égale à

r

. Le résultat est

\tilde{\mathbf{L}}_{1}(r) = −r^{2}/ 4

. Lʼapproche est une combinaison de méthode variationnelle et de procédé de limite, utilisant des résultats de continuité des solutions et des valeurs propres dʼéquations linéaires en les potentiels et les mesures dans des topologies faibles. Ces valeurs extrémales peuvent donner des estimations optimales sur les zéro-èmes valeurs propres de Neumann.
Global vorticity shedding for a vanishing wing
Authors: Wibawa M. S. , Steele S. C. , Dahl J. M. , Rival D. E. , Weymouth G. D. , Triantafyllou M. S. 
Published: February 2012

AbstractIf a moving body were made to vanish within a fluid, its boundary-layer vorticity would be released into the fluid at all locations simultaneously, a phenomenon we call global vorticity shedding. We approximate this process by studying the related problem of rapid vorticity transfer from the boundary layer of a body undergoing a quick change of cross-sectional and surface area. A surface-piercing foil is first towed through water at constant speed,$U$, and constant angle of attack, then rapidly pulled out of the fluid in the spanwise direction. Viewed within a fixed plane perpendicular to the span, the cross-sectional area of the foil seemingly disappears. The rapid spanwise motion results in the nearly instantaneous shedding of the boundary layer into the surrounding fluid. Particle image velocimetry measurements show that the shed layers quickly transition from free shear layers to form two strong, unequal-strength vortices, formed within non-dimensional time${t}^{\ensuremath{\ast} } = 0. 03$, based on the foil chord and forward velocity. These vortices are connected to, and interact with, the foil’s tip vortex through additional streamwise vorticity formed during the rapid pulling of the foil. Numerical simulations show that two strong spanwise vortices form from the shed vorticity of the boundary layer. The three-dimensional effects of the foil removal process are restricted to the tip of the foil. This method of vorticity transfer may be used for quickly introducing circulation to a fluid to provide forcing for biologically inspired flow control.
Anomalous dispersion in chemically heterogeneous media induced by long-range disorder correlation
Authors: Bolster D. , Dentz M. 
Published: February 2012

AbstractWe study transport in an idealized porous medium characterized by a spatially varying retardation factor, which models linear instantaneous chemical adsorption of a solute. Using a stochastic modelling approach, we study the impact of disorder correlation on the large-scale dispersion behaviour. We consider short, long-range and intermediate-range disorder correlations, and demonstrate that (truncated) power-law correlation causes anomalous dispersion, even in the presence of weak heterogeneity. We identify different preasymptotic and asymptotic regimes of anomalous dispersion that shed new light on the disorder and local-scale transport mechanisms leading to non-Fickian behaviour. The analytical results are complemented by numerical random walk particle tracking simulations, which are found to be in good agreement with the derived dispersion behaviour. We conclude the paper by deriving an effective transport equation for this system, which can be shown to be tied to the family of continuous-time random walk models.
Genetically variant populations of Paragonimus proliferus Hsia & Chen, 1964 from central Vietnam
Authors: Doanh P.N. , Hien H.V. , Nonaka N. , Horii Y. , Nawa Y. 
Published: February 2012

AbstractAmong about 50 nominal Paragonimus species, Paragonimus proliferus is rather a rare species, found only in Yunnan province, China, until our recent discovery of this species in Lai Chau province, northern Vietnam close to Yunnan, China. Here we add Quang Binh province, central Vietnam as a new endemic area of P. proliferus. Large excysted metacercariae found in mountainous crabs, Potamiscus tannanti, were morphologically identified as P. proliferus, which was confirmed further by molecular analyses. Second internal transcribed spacer (ITS2) sequences of the P. proliferus population in Quang Binh province were completely (100%) identical with those of P. proliferus populations in Lai Chau province, northern Vietnam and Yunnan province, China. However, cytochrome oxidase subunit 1 (CO1) gene sequences of Quang Binh population were significantly different (5.6%) from that of previously reported northern Vietnam and Yunnan, China populations. A phylogenetic tree revealed that all CO1 sequences of P. proliferus Quang Binh population formed a distinct group, which was clustered with northern Vietnam and Yunnan, China populations with the bootstrap value of 75%. This is the first record of the genetically variant population of P. proliferus, distribution of which is geographically remote from the previously reported endemic areas in the border between northern Vietnam and Yunnan, China, suggesting that P. proliferus may be much more widely distributed in the Indochina peninsula (or South-East Asia) than expected.
In the Absence of Men? Gender, Migration and Domestic Labour in the Southern Ecuadorean Andes
Authors: ABBOTS EMMA-JAYNE 
Published: February 2012

AbstractFemale heads of households in the migrant-exporting community of Jima, Ecuador, are using remittances to employ domestic workers. As both workers and ‘mistresses’ originate from the samemestizopeasant class, these new labour relations do not reflect embedded class inequalities, but are rather emerging as a new mode of distinction between newly prosperous households and those for whom migration has been a less successful strategy. This lends a temporal fragility and fluidity to household relations, as worker and employer seek to define their roles and establish hierarchies. Employers negotiate these tensions not only to reduce their own burden of labour, but also because domestic workers are a symbol of social mobility and help enhance the reputation of migrant men. Thus, while men are physically absent, they continue to inform the reorganisation of the Jimeño household, and there is little to suggest that gender roles are being realigned in a structurally significant manner.
You can't tell a book by its author: A study of Muʿtazilite theology in al-Zamakhsharī's (d. 538/1144) Kashshāf
Authors: Lane Andrew J. 
Published: February 2012

AbstractThis article examines the Kashshāf, the Quran commentary of the Muʿtazilite al-Zamakhsharī (d. 538/1144). This involves: (1) the continuous reading of the commentary on two sūras; (2) the study of al-Zamakhsharī's commentary in the Kashshāf on Quranic passages used by him or his teacher Ibn al-Malāḥimī (d. 536/1141) in their theological treatises; and (3) an analysis of a report claiming that al-Zamakhsharī had begun his commentary with the blatantly Muʿtazilite statement: “Praise be to God who created the Quran”. The conclusion is that the results of the study of the commentary on the two sūras reflect the overall theological content of the Kashshāf and that to consider the Kashshāf to be a Muʿtazilite Quran commentary amounts more to looking at the theological school of its author and to accepting medieval hearsay than it does to drawing conclusions based on a detailed examination of the relevant sources.