bluuebunny/crossref_metadata_2025_split huggingface dataset:
Excited State Structural Dynamics of the Charge Transfer State of Peridinin
Authors: Van Tassle Aaron J. , Prantil Matthew A. , Hiller Roger G. , Fleming Graham R. 
Published: June 2008

AbstractWe present infrared and visible transient absorption measurements of the first excited singlet state (S1 and S1/ICT) of peridinin in methanol, isopropanol, and chloroform solution following one‐photon excitation, using 490 nm light, to excite the S2 state that populates S1 via rapid (∼50 fs in methanol) internal conversion. This technique enables the study of subsequent structural dynamics in S1 involved in the formation of the charge transfer state. The S1 lifetime of peridinin in methanol, isopropanol, and chloroform is found to be 12, 54, and 65 ps, respectively, as determined by infrared transient absorption. We observe two formation timescales in the S1 state. We attribute the shortest timescale to relaxation following internal conversion and the longer timescale to formation of the S1/ICT state.
Simulations of Extreme Ionization and Electron Dynamics in Ultraintense Laser–Cluster Interactions
Authors: Heidenreich Andreas , Last Isidore , Jortner Joshua 
Published: June 2008

AbstractWe present a molecular dynamics (MD) simulation code for the exploration of extreme multielectron ionization and attosecond–femtosecond electron dynamics in elemental and molecular clusters driven by ultraintense (peak intensity IM= 1015–1016W cm−2), ultrafast (temporal pulse widths τ = 10–100 fs), near infrared (photon frequency 0.35 fs−1) laser fields. Validity conditions are presented for the applicability of classical MD simulations to high‐energy electron dynamics, which rest on the localization of the wave packet and the distinguishability of identical particles. We also examine the cluster size domain for the applicability of the MD simulation code where the laser intensity is uniform inside the cluster.
High‐throughput enzyme kinetics using microarrays
Authors: Lu Guoxin , Yeung Edward S. 
Published: June 2008

AbstractWe report a microanalytical method to study enzyme kinetics. The technique involves immobilizing horseradish peroxidase on a poly‐L‐lysine (PLL)‐coated glass slide in a microarray format, followed by applying substrate solution onto the enzyme microarray. Enzyme molecules are immobilized on the PLL‐coated glass slide through electrostatic interactions, and no further modification of the enzyme or glass slide is needed. In situ detection of the products generated on the enzyme spots is made possible by monitoring the light intensity of each spot using a scientific‐grade charged‐coupled device (CCD). Reactions of substrate solutions of various types and concentrations can be carried out sequentially on one enzyme microarray. To account for the loss of enzyme from washing in between runs, a standard substrate solution is used for calibration. Substantially reduced amounts of substrate solution are consumed for each reaction on each enzyme spot. The Michaelis constant Km obtained by using this method is comparable to the result for homogeneous solutions. Absorbance detection allows universal monitoring, and no chemical modification of the substrate is needed. High‐throughput studies of native enzyme kinetics for multiple enzymes are therefore possible in a simple, rapid, and low‐cost manner.
Tip‐enhanced Raman spectroscopy reveals rich nanoscale adsorption chemistry of 2‐mercaptopyridine on Ag
Authors: Zhang Weihua , Schmid Thomas , Yeo Boon Slang , Zenobi Renato 
Published: June 2008

AbstractAdsorption of 2‐mercatopyridine (2MPy) on Ag surfaces was studied by tip‐enhanced Raman spectroscopy (TERS), which allows the measurement of Raman spectra with nanometer scale spatial resolution on flat surfaces that themselves do not show any surface‐enhancement Raman scattering (SERS) activity. We found that the adsorption behavior of 2MPy was affected by the parameters of the preparation for the adsorbate layers, i.e., solution concentration, solution volume, and the exposure time. Besides that, variation of the TERS spectra at randomly chosen sample positions was observed. Only some of the bands appearing in SERS experiments showed up in each TERS measurement. We propose that this is caused by different local adsorption behavior of 2MPy on the Ag surfaces. This observation perfectly demonstrates the advantage of TERS over SERS, i.e., TERS can give localized chemical information on the nanometer scale, whereas SERS can only afford average spectra with micrometer scale resolution. Finally, TERS mapping with a spatial resolution of 24 nm was demonstrated.
Aging effects in analysis of polycyclic aromatic hydrocarbon aerosols
Authors: Bulatov Valery , Gridin Vladimir V. , Fisher Michal , Sluszny Chanan , Schechter Israel 
Published: June 2008

AbstractPolycyclic aromatic hydrocarbon (PAH) aerosols undergo time‐dependent processes such as various aging effects and material loss due to sublimation. Therefore, when their analysis is delayed, the results may not properly represent the true environmental composition as sampled. Moreover, even when fast analysis is performed, one may still be interested in the initial concentration of these aerosols, at the moment of their formation. In both cases, a characterization of the time dependence of aerosol mass losses and other possible modifications is of interest. In this study we monitored these time‐dependent processes for three different PAH aerosol particulates (anthracene, perylene, and pyrene). We applied two experimental techniques: Fourier transform spectral imaging microscopy (FT‐SIM) and traditional HPLC analysis. The former provided a full fluorescence spectrum at each pixel of the particulate, as well as PAH identification and quantification. The chemical imaging information was also used for morphological characterization of the PAH aerosols, which was applied for developing of a simple mathematical model. The effect of the time‐delay upon the actual aerosol mass can thus be estimated. The original (as‐formed or as‐sampled) aerosol mass can be calculated using the proposed empirical model.
Large time‐step, fast‐switching free energy calculations with non‐symplectic integrators
Authors: Oberhofer Harald , Dellago Christoph 
Published: June 2008

AbstractIn recent work (Lechner et al.,J. Chem. Phys.124, 044113 (2006)) we have shown how to generalize Jarzynski's fast switching method for the computation of free energy differences to large time‐step trajectories. Although such trajectories mimic the true time evolution of the system only approximately, the resulting free energies are exact. The large time‐step approach, which can lead to considerable efficiency increases, is particularly simple for phase space volume conserving algorithms such as the velocity Verlet integrator. In this paper we explore the consequences of using non‐symplectic integration algorithms, which do not conserve phase space volume, in fast switching simulations. We find that if the phase space volume expansion or contraction is taken into account properly, the large time‐step approach remains valid and may yield considerable efficiency improvements. If, however, the change in phase space volume caused by the integration algorithm is simply neglected, serious inaccuracies of the free energy estimate may arise, particularly for large system sizes.
Resonance theory of electromagnetically induced transparency: The effect of structured multi‐continua
Authors: Shapiro Moshe 
Published: June 2008

AbstractWe present a comprehensive theory of Electromagnetically Induced Transparency (EIT) based on the overlapping resonances perspective and explore the consequence of the presence of structured multiple continua on the EIT effect. We show that due to the structure in the continuum (which can also be induced optically) the EIT line shapes may become highly asymmetric.
Pirouetting in chiral [2]catenanes
Authors: Kang Seogshin , Aprahamian Ivan , Stoddart J. Fraser 
Published: June 2008

AbstractOne of the best known classes of mechanically interlocked molecules is the category of [2]catenanes, which exhibit donor‐acceptor interactions between the 1,5‐dioxynaphthalene (DNP) units in a crown ether and the bipyridinium units in the tetracationic cyclophane, cyclobis(paraquat‐p‐phenylene) (CBPQT4+). In order to gain an in‐depth understanding and appreciation of the stereochemistry and dynamic behavior of these [2]catenanes, chiral analogues—having both the DNP ring, which is capable of displaying planar chirality, and the axially chiral binaphthol (BINAP) moiety (as both enantiomers and as the racemic modification), in a crown ether, in addition to the CBPQT4+ cyclophane—have been synthesized using a template‐directed protocol. Dynamic 1H NMR spectroscopy shows that (i) the presence of immutable axial chirality, arising from the BINAP moiety in the crown ether component, leads to no induction of diastereoselectivity—the chiral catenanes exist as a mixture of diastereoisomers in solution at low temperatures in the approximate ratio of 1:1, (ii) the barrier (ΔGcD̊) to the interconversion between these two diastereoisomers is 7.9 ± 0.1 kcal mol−1 at 171 K, and (iii) no induction of diastereoselectivity is observed upon the addition of a chiral solvating agent to the chrial catenanes. The pattern of behavior in the variable temperature 1H NMR spectra and the low ΔTGcD̊ value indicates that the dynamic process involving the interconversion between these two diastereoisomers is one of a pirouetting nature. Of the four possible diastereoisomers, only two, (R)‐(pR/pS) or (S)‐(pR/pS), are shown to exist in solution.
Chemical amplification in an invaded food web: Seasonality and ontogeny in a high-biomass, low-diversity ecosystem
Authors: Ng Carla A , Berg Martin B , Jude David J , Janssen John , Charlebois Patrice M , Amaral Luis A. N , Gray Kimberly A 
Published: June 2008

Abstract
The global spread of invasive species is changing the structure of aquatic food webs worldwide. The North American Great Lakes have proved particularly vulnerable to this threat. In nearshore areas, invasive benthic species such as dreissenid mussels and round gobies (Neogobius melanostomus) have gained dominance in recent years. Such species are driving the flow of energy and material from the water column to the benthic zone, with dramatic effect on nutrient and contaminant cycling. Here, we develop a stage-structured model of a benthified food web in Lake Michigan with seasonal resolution and show how its bioaccumulation patterns differ from expected ones. Our model suggests that contaminant recycling through the consumption of lipid-rich fish eggs and mussel detritus is responsible for these differences. In southern Lake Michigan's Calumet Harbor (Chicago, IL, USA), round gobies have nitrogen isotope signatures with considerable spread, with some values higher than their predators and others lower than their prey. Contrary to patterns observed in linear pelagic systems, we predict that polychlorinated biphenyl (PCB) concentrations in these fish decrease with increasing size due to the lipid- and benthos-enriched diets of smaller fish. We also present here round goby PCB concentrations measured in 2005 after an invasional succession in Calumet Harbor and demonstrate how the change from one invasive mussel species to another may have led to a decrease in round goby PCB accumulation. Our results suggest that benthic-dominated systems differ from pelagic ones chiefly due to the influence of detritus and that these effects are exacerbated in systems with low species diversity and high biomass.
Dissolved oxygen supersaturation and its impact on bubble formation in the southern Baltic Sea coastal waters
Authors: Marks R. 
Published: June 2008

The dissolved oxygen supersaturation in the surface waters was investigated as a factor influencing bubble formation in the southern Baltic Sea coastal waters in Warszów, Lubiatowo and Hel from 1995 to 2007. To quantify the changes of oxygen supersaturation, data were collected along transects using integrated dissolved oxygen and water temperature sensors, either mounted on a remotely operated platform or deployed manually.
Data revealed that an excess of solar energy in the nutrient-rich Baltic Sea coastal waters caused an immediate warming of sea bed and bottom water, which induced gaseous supersaturation and enhanced biological production of oxygen by phytoplankton. Both processes increased the degree of dissolved oxygen saturation, which became highly supersaturated, especially during the spring and summer time. Such conditions are favourable for enhanced formation of bubbles in the water, which enhanced the release of gases (mostly oxygen) into the air. Gaseous evasion is, in particular, enhanced in the presence of breaking waves and whitecaps that are typically formed over coastal ridges and at the shore line. Laboratory experiments indicated that, with the increasing degree of dissolved oxygen supersaturation, both the number of bubbles produced in the water and their sizes increase.
Benefits, limitations and uncertainty of in situ spectrometry
Authors: Winkler S. , Saracevic E. , Bertrand-Krajewski J.-L. , Torres A. 
Published: June 2008

In situ spectrometers are comparable robust instruments and can be operated long term with relatively low maintenance demand. The decisive factor for their applicability is the development of a medium and installation location specific correlation model, which estimates the concentration of the requested target parameter from the measured absorption values. In some cases it might turn out, that the development of a single site specific correlation model is not sufficient, due to frequent and substantial variations of the (waste) water composition.
In order to assess the total uncertainty of in situ spectrometry, a comprehensive lab test was carried out. It includes a detailed investigation of the uncertainty of CODreference methods (DIN and small tube tests), a precision analysis of the absorption spectra and the impact of those two factors on the total uncertainty of the CODEQ correlation model.
The development of a risk-based approach to managing the ecological impact of pollutants in highway runoff
Authors: Crabtree B. , Dempsey P. , Johnson I. , Whitehead M. 
Published: June 2008

In the UK, the Highways Agency is responsible for the strategic road network. It is recognised that current design guidance to control pollutants in highway runoff is out of date. A research programme is in progress to develop a better understanding of pollutants in highway runoff and their ecological impact. The paper summarises the outcome of a study to: (1) monitor pollutants in highway runoff under different climate and traffic conditions at 24 sites; (2) develop standards to assess potential ecological risks; and (3) develop a model to predict pollutant concentrations in highway runoff.
Data collection and analysis of the resulting data have identified a link between pollutant concentrations and traffic density. A number of pollutants routinely present in highway runoff have been identified as posing the greatest ecological risk. Ecologically based standards for acute impacts have been derived for the soluble form of these pollutants. These standards will be used in conjunction with the model to indicate where runoff treatment may be required to mitigate ecological risk. The model and standards will be used to develop improved design guidance to protect receiving waters from pollutants in highway runoff by identifying where runoff treatment is required, and to what degree.
Passive infrared detector used for detection of very slowly moving of crawling people
Authors: Kastek M. , Sosnowski T. , Piątkowski T. 
Published: June 2008

AbstractThe paper presents construction and principle of operation of passive IR detectors (PIR detectors) of a large detection range. Important virtue of these detectors is highly efficient detection of slowly moving or crawling people. The described here PIR detector detects crawling people at the distance of 140 m. To ensure high probability of detection of slowly moving objects, new method of signals analysis was applied. On the basis of the carried out real-time measurements, both probability of detection and false alarms were determined.
Intermolecular interactions in Langmuir-Blodget films of liquid crystalline perylene derivatives
Authors: Hertmanowski R. , Martyński T. , Stolarski R. , Bauman D. 
Published: June 2008

AbstractLangmuir-Blodgett (LB) films formed of some discotic liquid crystals, namely 3,4,9,10-tetra-(n-alkoxy-carbonyl)-perylenes, mixed with arachid acid have been studied. The absorption and fluorescence spectra were recorded. The results obtained have led to conclusions about formation of self-aggregates of dye molecules both in ground and excited states at the air-solid substrate interface. It was found that some fraction of J-aggregates can be created in the ground state. In the excited state, mostly excimers appear and the number of this kind of aggregates depends on the length of the alkyl chains substituted to the perylene core, as well as on the dye concentration and the number of layers in LB films.
A parametric method for evaluation of resistance of swath ships
Authors: Michalski Jan 
Published: June 2008

A parametric method for evaluation of resistance of swath ships
This paper contains formulation of a parametric method for evaluation of SWATH ship's hull resistance. The method was elaborated on the basis of numerical calculation results obtained by using structural methods based on ship hydrodynamic theory and performed for sufficiently large series of body forms with systematically changing ship form parameters. Also, results of verifying investigations dealing with features of the method in question are presented by comparing the obtained resistance characteristics with those achieved by other authors as well as with ship model experimental test results. The obtained results of the verification indicate that the elaborated method can be useful in preliminary designing the SWATH ships.
Hydrodynamic Analysis of Trimaran Vessels
Authors: Javanmardi M. , Jahanbakhsh E. , Seif M. , Sayyaadi H. 
Published: June 2008

Hydrodynamic Analysis of Trimaran Vessels
Trimaran vessels are developed for different applications and hydrodynamic behavior of such vessels is different than usual mono-hulls. In this paper hydrodynamic resistance and maneuvering of a trimaran with Wigley body form are investigated. The effects of outriggers position in four different longitudinal and two transverse locations are studied. For hydrodynamic simulations a CFD code has been developed and used. This code is capable for simulating three dimensional, time dependent, two phases, viscous flow coupled with rigid body motion. Formulation and solution algorithm are described in detail. Different case studies have been performance and numerical results have shown good agreement with experimental data. Based on resistance and maneuvering simulation of the trimaran vessels different conclusion are made. The results show that positions of outriggers have great effect on resistance and maneuverability of trimaran. The present method can be further employed to investigate other hydrodynamic qualities of trimaran vessels.
Dissipation energy in viscoelastic solids under multiaxial loads
Authors: Kolenda Janusz 
Published: June 2008

Dissipation energy in viscoelastic solids under multiaxial loads
On the basis of the three-dimensional constitutive equations for strains resulting from the Kelvin-Voigt's model and modified Hooke's law for multiaxial stress in viscoelastic solids, the formulae for the energy dissipated in a given time per unit volume have been derived. It is shown that after application or removal of triaxial static load there is no difference in the time functions governing the dissipation of strain energy of volume change and the dissipation of strain energy of distortion. Harmonic in-phase stress and harmonic out-of-phase stress as well as multiaxial periodic stress are also considered. It is demonstrated that in the process of energy dissipation due to normal and shear stress components the role of the latter is dominant.
Management of assignment of operational tasks realized in ship power plant
Authors: Kamiński Piotr , Tarełko Wiesław 
Published: June 2008

Management of assignment of operational tasks realized in ship power plant
The frequent cause of ships' detentions by port authorities are abnormalities of ship power plant functioning. Each extended ship lay time in port results in waste of ship operating time thus costs rise to shipowners. This is connected with improper ship power plant management. In order to avoid this, a ship engineer should have at his disposal computer aided system supporting him in managing of ship power plant. Such a system can be worked out on condition that mathematical formula which represents the decision - making process of an engineer has been built. The present work shows approache to the problem according to the situation in which the engineer is made to take certain decisions. In formulation of the most substantial operating states of a ship like lay time in harbour and sea voyage the ‘knapsack algorithm’ was applied. For both approaches objective function was formulated.
Statistical analysis of sea accidents and breakdowns in the Polish Navy
Authors: Korczewski Zbigniew 
Published: June 2008

Statistical analysis of sea accidents and breakdowns in the Polish Navy
This paper presents the results of systematic, statistical approach to naval accidents and breakdowns which occurred in the Polish Navy between years 1985 - 2004. Additionally, the author of this work has made an initial assessment of the human factor. Human errors, which appeared on considered warships in the examined period of time, have been analyzed in the overall number of accidents and breakdowns.
Pocklington's Theorem and Bertrand's Postulate
Authors: Riccardi Marco 
Published: June 2008

Pocklington's Theorem and Bertrand's Postulate
The first four sections of this article include some auxiliary theorems related to number and finite sequence of numbers, in particular a primality test, the Pocklington's theorem (see [19]). The last section presents the formalization of Bertrand's postulate closely following the book [1], pp. 7-9.
The Definition of Finite Sequences and Matrices of Probability, and Addition of Matrices of Real Elements
Authors: Zhang Bo , Nakamura Yatsuka 
Published: June 2008

The Definition of Finite Sequences and Matrices of Probability, and Addition of Matrices of Real Elements
In this article, we first define finite sequences of probability distribution and matrices of joint probability and conditional probability. We discuss also the concept of marginal probability. Further, we describe some theorems of matrices of real elements including quadratic form.
The Jordan-Hölder Theorem
Authors: Riccardi Marco 
Published: June 2008

The Jordan-Hölder Theorem
The goal of this article is to formalize the Jordan-Hölder theorem in the context of group with operators as in the book [5]. Accordingly, the article introduces the structure of group with operators and reformulates some theorems on a group already present in the Mizar Mathematical Library. Next, the article formalizes the Zassenhaus butterfly lemma and the Schreier refinement theorem, and defines the composition series.
Regular Expression Quantifiers — m to n Occurrences
Authors: Trybulec Michał 
Published: June 2008

Regular Expression Quantifiers —mtonOccurrencesThis article includes proofs of several facts that are supplemental to the theorems proved in [10]. Next, it builds upon that theory to extend the framework for proving facts about formal languages in general and regular expression operators in particular. In this article, two quantifiers are defined and their properties are shown:mtonoccurrences (or the union of a range of powers) and optional occurrence. Although optional occurrence is a special case of the previous operator (0 to 1 occurrences), it is often defined in regex applications as a separate operator - hence its explicit definition and properties in the article. Notation and terminology were taken from [13].