bluuebunny/crossref_metadata_2025 huggingface dataset:
Robust option replication for a Black‐Scholes model extended with nondeterministic trends
Authors: Schoenmakers John G. M. , Kloeden Peter E.
Published: March 2007

Statistical analysis on various stocks reveals long range dependence behavior of the stock prices that is not consistent with the classical Black and
Scholes model. This memory or nondeterministic trend behavior is often
seen as a reflection of market sentiments and causes that the historical volatility estimator becomes unreliable in practice. We propose an extension
of the Black and Scholes model by adding a term to the original Wiener
term involving a smoother process which accounts for these effects. The
problem of arbitrage will be discussed. Using a generalized stochastic integration theory [8], we show that it is possible to construct a self financing
replicating portfolio for a European option without any further knowledge
of the extension and that, as a consequence, the classical concept of volatility needs to be re‐interpreted.
Convergence of an iteration leading to a solution of a random operator equation
Authors: Choudhury Binayak S. , Ray M.
Published: March 2007

In the present paper, we define a random iteration scheme and consider its
convergence to a solution of a random operator equation. There is also a
related fixed point result.
Uniqueness of solutions to integrodifferential and functional integrodifferential equations
Authors: Bahuguna D. , Garey L. E.
Published: March 2007

In this paper we study a class of integrodifferential and functional integro‐differential equations with infinite delay. These problems are reformulated
as abstract integrodifferential and functional integrodifferential equations.
We use Nagumo type conditions to establish the uniqueness of solutions to
these abstract equations.
Existence, uniqueness and continuability of solutions of impulsive differential‐difference equations
Authors: Bainov D. D. , Stamova I. M.
Published: March 2007

We consider an initial value problem for impulsive differential‐difference equations, and obtain sufficient conditions for the existence, uniqueness, and continuability of solutions of such problem.
A diffusion model for two parallel queues with processor sharing: transient behavior and asymptotics
Authors: Knessl Charles
Published: March 2007

We consider two identical, parallel M/M/1 queues. Both queues are fed
by a Poisson arrival stream of rate λ and have service rates equal to μ.
When both queues are non‐empty, the two systems behave independently
of each other. However, when one of the queues becomes empty, the corresponding server helps in the other queue. This is called head-of-the-line processor sharing. We study this model in the heavy traffic limit, where
ρ = λ/μ → 1. We formulate the heavy traffic diffusion approximation and
explicitly compute the time‐dependent probability of the diffusion approximation to the joint queue length process. We then evaluate the solution
asymptotically for large values of space and/or time. This leads to simple
expressions that show how the process achieves its stead state and other
transient aspects.
Sojourn time distributions in a Markovian G‐queue with batch arrival and batch removal
Authors: Shin Yang Woo
Published: March 2007

We consider a single server Markovian queue with two types of customers;
positive and negative, where positive customers arrive in batches and arrivals of negative customers remove positive customers in batches. Only
positive customers form a queue and negative customers just reduce the
system congestion by removing positive ones upon their arrivals. We derive the LSTs of sojourn time distributions for a single server Markovian
queue with positive customers and negative customers by using the first
passage time arguments for Markov chains.
Analysis of an N/G/1 finite queue with the supplementary variable method
Authors: Lee Gyemin , Jeon Jongwoo
Published: March 2007

In this paper, we suggest a new approach to the analysis of an N/G/1 finite queue with the supplementary variable method. Compared to the conventional approach, our approach yields a simpler formula for the queue
length distribution, which in turn gives a more efficient computational
algorithm. Also, the new approach enables us to derive the joint density
of the queue length and the elapsed service time.
Aggregation of cation‐anionic and related polymethine dyes
Authors: Tatikolov A. S. , Ponterini G. , Krasnaya Zh. A.
Published: March 2007

Absorption, fluorescence, and fluorescence excitation spectra were studied for a number of
cation‐anionic and related anionic polymethine dyes in weakly polarand nonpolarsolvents, as well as
in binary mixtures of solvents of different polarity. For some dyes, aggregation is observed in toluene or
acetonitrile‐toluene mixtures with low amounts of acetonitrile, which is revealed as appearance of new absorption
bands and/or broadening of the initial bands of a monomeric dye. Solvent mixtures butyronitrilehexane
with low butyronitrile content were found to greatly stimulate the formation of dye aggregates for
most of the dyes studied. The absorption spectra of the aggregates are often blue‐shifted with respect
to the corresponding absorption spectra of parent monomeric dyes and/or represent broad continuums
located both in the blue and red regions. For one of the cation‐anionic dyes studied, which consists of
3, 3′‐diethylthiamonomethinecyanine cation and trimethinebenzoxanine anion, fluorescent aggregates were
observed; their broad fluorescence band is located in the long‐wavelength region. For this dye, gradual transition
from nonfluorescent aggregates to fluorescent ones and then to monomeric ion pairs and dissociated
ions was observed in butyronitrile‐hexane mixtures with growing butyronitrile content.
Model for the phycobilisome rod with interlocking disks based on domain‐weighted linker‐polypeptide sequencehomologies of Mastigocladus laminosus
Authors: Parbel Axel , Scheer Hugo
Published: March 2007

The 8 linker‐polypeptides from the cyanobacterium Mastigocladus laminosus were examined
by comparative amino‐acid sequence analysis for the predicted domain structure reported in the literatur
(Glauser 1991, Esteban 1993) in detail using split sequences for the rod, rod‐core and for the repeats from
the core‐membrane linker‐polypeptide (Lcm 127.6). This analysis gives two distinct domains, where domain
1 (∼ 22 kDa, identity between 31 and 70%) is present in the N‐terminal two thirds of the class II linkers
(∼ 30 kDa) and in the repeats of the Lcm 127.6, and domain 2 (∼ 10 kDa, identity between 28 and 41%) in
the C‐terminal part of the class II rod linkers (Lr31.5 and Lr32.5) and in the two capping linkers (Lc7.7 and Lr8.2). Based on these data, X‐ray structure analysis from phycobiliproteins and proteolysis experiments, an
interlocking model for the phycobilisome rod organization is proposed, with linkers protruding from one
phycobilisome disk into the neighbouring one.
pH dependence of the protein orientation in self‐assembled bacteriorhodopsin/polycation multilayer films
Authors: Jussila Tapio , Li Meiling , Tkachenko Nikolai V. , Parkkinen Sinikka , Li Baofang , Jiang Long , Lemmetyinen Helge
Published: March 2007

Bacteriorhodopsin (bR) multilayer films were successfully prepared by alternatingdepositions
of cationic poly(diallyldimethylammonium chloride) (PDAC) polyelectrolyte and purple membrane (PM). The
advantage of the method when compared to other thin film techniques is its simplicity to prepare large selfassembled
films. The orientations of the bR molecules in the films were studied by a transient photovoltage
method. The polarity of the photoresponse signals showed that in basic conditions the cytoplasmic side of PM
was adsorbed onto the polyelectrolyte layer, whereas in acidic conditions the extracellular side was adsorbed
onto the polyelectrolyte layer. The photocycle of the bR in the films was studied by usingthe conventional
flash photolysis method. The photochemical behavior of bR in dry polycationic films was similar to that in
other types of dry films and the intermediate lifetimes were almost independent of the protein orientation.

The photovoltage signals introduce opposite proton transport directions for the formation of the K intermediate
of the photocycle and for the successive relaxation to M intermediate. The charge displacement
associated to the M intermediate was several times greater than that of the K intermediate. The fittings of the
transient photovoltage signals resulted the values of 2, 15, and 70 microseconds for the time constants of
the 3‐exponential formation of the M intermediate. The kinetic data were compared to the results obtained
with the transient absorption measurements.
Photocatalytic degradation of salicylic acid on fixed TiO2 ‐ kinetic studies
Authors: Ould-Mame S. M. , Zahraa O. , Bouchy M.
Published: March 2007

The photocatalytic activity of TiO2 deposits (Degussa‐P25 and Sachtleben‐Hombikat) has been
studied using salicylic acid as a model water pollutant and an UV‐fluorescent lamp as a light source.
Both catalysts have shown very similar properties towards the photocatalytic degradation of salicylic acid.
Special attention has been given to the effect of the light flux absorption and of the pollutant adsorption.
Moderate mass‐transfer limitation has been found. Specific parameters of the phenomenon have then been
determined for the two catalysts and a simple general expression of the rate of photocatalytic degradation
has been derived.
Photolysis of dicamba (3,6‐dichloro‐2‐methoxybenzoic acid) in aqueous solution and dispersed on solid supports
Authors: Aguer Jean-Pierre , Blachère Frédéric , Boule Pierre , Garaudee Sandrine , Guillard Chantal
Published: March 2007

Dicamba (3,6‐dichloro‐2‐methoxybenzoic acid) was exposed to UV light in aqueous solution.
It was also irradiated in the solid phase without support or adsorbed on laponite (a synthetic clay) and
ferric oxide.

Two main photoproducts (1) and (2) were identified in irradiated aqueous solutions. Both involve the
substitution of chlorine by OH. The unexpected product (2) is formed through a kinetic reaction of primary
product; it results from an oxidation and it is not formed in the absence of oxygen.

A huge number of intermediate products were simultaneously formed when dicamba is irradiated in the
solid phase in presence of laponite. They correspond to methylation, decarboxylation, chlorination, dechlorination,
and hydroxylation reactions. The latter is probably due to the presence of water in clays, whereas
methylation, chlorination and decarboxylation have been attributed to the cage effect and to an energy transfer
process. Without support or with ferric oxide, no decarboxylation occurs. The nature of the inorganic
support also modify the kinetics of dicamba photolysis.
Spectroscopic and photoelectric studies of phthalocyanines in polyvinyl alcohol for application in solar energy conversion
Authors: Wróbel Danuta , Boguta Andrzej , Ion Rodica M.
Published: March 2007

Phthalocyanines are synthetic dyes which are shown to be good photoconverters which can be
applied in a photoelectrochemical cell constructed of semiconducting and metallic electrodes. By means of
spectroscopic investigation (absorption,fluorescence and photoacoustics) we have followed spectral properties
of phthalocyanines complexed with metals dissolved in polyvinyl alcohol solution in order to determine
the pathways of deactivation of their excited states. Spectroscopic investigations were accompanied with
photovoltaic/photocurrent and current‐voltage characteristics of the photoelectrochemical cell with dyes. It
has been shown that there is a correlation between dye fluorescence feature and dye ability to electric photoconversion.
The comparison of new data for metallic phthalocyanines with those obtained for porphyrins
is discussed.
Photochemical formation of oxetanes derived from aromatic ketones and substituted thiophenes and selenophenes
Authors: Vargas Franklin , Rivas Carlos
Published: March 2007

The photochemical formation of oxetanes from different heterocycles have been investigated
for many years in this laboratory. Thus far, only correlation between quenching effect of the heterocycles
and capability of forming oxetanes have been established but no attempts have been made to elucidate from
these data the different mechanistic pathways that lead from starting materials to product in various cases.
In the light of kinetic as well as ionization potential information an attempt is made in this review to establish
the mechanisms involved in these reactions. By means of the studies of the Stern‐Volmer plots, the
quenching constants of the reaction of Paternò‐Büchi between substituted thiophene and selenophene with
aromatic ketones and their relationship with the potentials of ionization of these heterocycles we can infer
in the efficient synthesis of oxetanes.
Photo‐induced processes in heterogeneous nanosystems. From photoexcitation to interfacial chemical transformations
Authors: Emeline A. , Salinaro A. , Ryabchuk V. K. , Serpone N.
Published: March 2007

This article briefly reviews some of our recent work carried out both from an experimental
point of view as well as from a theoretical perspective to gain further understanding of the events that take
place in Heterogeneous Photocatalysis. Previously, the multitude of reports from our laboratory and from
many others looked at the primary photocatalytic events as involving (a) absorption of light, (b) formation
of the free (electrons and holes) and/or trapped charge carriers (Ti3+ and •OH radicals), and (c) reaction
of pre‐adsorbed acceptor or donor molecules with the relevant trapped carrier. Our recent work notes that
this view is reasonable if the only purpose of photocatalysis is elimination of undesirable environmental
pollutants. But when we begin to query how to render a process more efficient, we need to address the
primary events following photoexcitation of the photocatalyst, which in most instances has been titanium
dioxide (in the anatase form). Owing to the nature of light absorption by TiO2 we resorted to examining other
metal oxides, most of which are dielectric insulators with very large bandgap energies, for example zirconia
(ZrO2) and scandia (Sc2O3). These dielectrics have provided added information on the photophysical events,
many of which are masked by the strong light absorption in titania. Despite some of our recent progress,
much remains to be done for a fuller understanding of the events that occur at the surface, which we have
often considered to be the greatest and most complex defect in metal oxide particulates.
Photochemical reactivity of zinc tetraphenylporphyrin induced by nonstoichiometric CdS nanoparticles in 2‐propanol
Authors: Isarov Alex V. , Chrysochoos John
Published: March 2007

The photoreactivity of zinc tetraphenylporphyrin (ZnTPP) in the presence of photoexcited CdS
nanoparticles and molecular oxygen in 2‐propanol has been revisited. The photodecomposition of ZnTPP in
2‐propanol, in the presence of CdS(e- CB/h+ VB) and molecular oxygen, is linked to isopropyl free radicals
formed by both hole transfer from CdS(h+ VB) to CHOH and the reaction of superoxide ion (O2 −) with 2‐propanol. Isopropyl free radicals react with ZnTPP, leading to the formation of ZnTPP•−. Intermediate
paramagnetic species monitored by EPR spectroscopy (g = 2.0029, ΔH = 5.7G) were characterized as superoxides
formed in the reaction of ZnTPP•− with O2. Further transformations of such EPR‐active species lead
to the formation of diamagnetic intermediate photoproducts of ZnTPP observed by absorption and emission
spectroscopy.
Solid‐state photochemistry: new approaches based on new mechanistic insights
Authors: Kaupp Gerd
Published: March 2007

The application of atomic force microscopy (AFM) to solid‐state photodimerizations revealed previously
unexpected long‐range molecular movements in the initial stages (phase rebuilding) and in the final
stages (phase transformation and disintegration) of reaction. The consequences for the new understanding
of solid‐state photochemistry are discussed. The 4.2 Å criterion of organic topochemistry lacks a real basis
and is not applicable to regular photolyses, even under tail irradiation conditions for instance of α‐cinnamic acid or in E/Z‐isomerizations in the crystal bulk. The experimental observation of molecular movements in
reacting crystals requires more elaborate use of X‐ray structural data by invoking the molecular packing. If a
crystal keeps its outer form upon photolysis this does not necessarily indicate a topotactic transformation,
and submicroscopically resolved AFM investigations are in order. The applications of molecular movements
or non‐photoreactivities due to the prevention of movements by 3D‐interlocked packing have numerous
applications. Thus, amorphous solids or inclusion compounds may enable the movements in these cases.
Hitherto puzzling E/Z‐photoisomerizations in the crystalline state can now be mechanistically understood.
In some cases even rotational mechanisms can be modelled in combination with the movements. In others
the space saving twist mechanism is the only choice. The benefits of the new solid‐state mechanisms for
crystal engineering, photochromism, mixed crystals, absolute asymmetric syntheses, and preparative photochemistry
derive from its experimental basis. Numerous presumed puzzles from the postulate of minimal
atomic and molecular movement vanish in a straightforward manner.
Preparation of the group III nitride thin films AlN, GaN, InN by direct and reactive pulsed laser ablation
Authors: Mele Aldo , Giardini Anna , Di Palma Tonia M. , Flamini Chiara , Okabe Hideo , Teghil Roberto
Published: March 2007

The methods of preparation of the group III nitrides AlN, GaN, and InN by laser ablation (i.e. laser
sputtering), is here reviewed including studies on their properties. The technique, concerns direct ablation
of nitride solid targets by laser to produce a plume which is collected on a substrate. Alternatively nitride
deposition is obtained as a result of laser ablation of the metal and subsequent reaction in an NH3 atmosphere. Optical multichannel emission spectroscopic analysis, and time of flight (TOF) mass spectrometry
have been applied for in situ identification of deposition precursors in the plume moving from the target.
Epitaxial AlN, GaN, and InN thin films on various substrates have been grown. X‐ray diffraction, scanning
electron microscopy, have been used to characterise thin films deposited by these methods.
Laser induced desorption and ablation: mechanism of metal removal from an Al‐Cu‐Fe alloy and a quasicrystal of the same composition
Authors: Satta Mauro , Liu Haichen , Mao Xianglei , Moretti Giuliano , Russo Richard E. , Giardini Anna , Mele Aldo
Published: March 2007

Quasicrystals are a special class of metallic alloys that share some of the properties of crystals.
Their structures reduce to a single repeating unit like that of the unit cell of a crystal. The quasi‐unitcell
is representative of a cluster like structure where electrons cannot move with freedom as in metals.
Quasicrystals are formed of metallicelements but they do not have metallic properties.

The diversity of the fractionation behavior induced by laser desorption and ablation of the Al70Cu20Fe10 of the intermetallicalloy and of the Al65Cu23Fe12 quasicrystal has been examined in terms of the structural
properties of the two compounds. Elemental fractionation during laser desorption and ablation sampling
was investigated by using inductively coupled plasma mass spectrometry. The experiments were carried out
in two different irradiance regimes by a Nd‐YAG laser with 266 nm wavelength and single 6 nanosecond laser
pulses. In the high irradiance regime (>0.04, 0.07GW/cm2) the effect of the laser irradiance is not discriminating.
In the low irradiance regime (<0.04, 0.07GW/cm2) large differences have been found between the
alloy and the quasicrystal. The results have been interpreted on the basis of a thermodynamic vaporization
process for the intermetallic alloy. An electronic model of localized excitation is suggested for the physical
process of surface material removal from a quasicrystal.
An interdisciplinary experience on the development of Dye‐Cell technology
Authors: Garcia Christian Graziani , Iha Neyde Yukie Murakami
Published: March 2007

Under a special program supported by the University of São Paulo (USP) for the development
of strategic fields of research, interdisciplinar discussion on the development of photovoltaics and energy
technology has been established. Several aspects concerned to solar energy and PV technology were discussed
in regular meetings along a year by professionals of different domains. As a result of the program,
a collaborative work on the deposition of TiO2 films employed in photoelectrochemical solar cells has been
established between the Laboratory of Inorganic Photochemistry and Energy Conversion at the IQ‐USP and
other research groups.

Preparation of TiO2 emulsions from distinct methods were performed and compared. Spin‐coating and
painting techniques have been employed for the deposition of TiO2 films over TCO substrates. Both techniques
resulted in transparent homogeneous TiO2 films which were successfully used as dye‐sensitized
photoanodes in solar cells. The results show that thin‐film properties, such as thickness and transparency,
can be controlled through the deposition technique and that photoelectrochemical measurements carried
out by our group have been performed under appropriate film deposition conditions.

This experience shows also that different institutions, with distinct purposes, can interact and work together
to prepare qualified professionals for many areas of modern science and technology.
Light driven isomerization of coordinated ligand andmodulation of fac‐[Re(CO)3(phen)(trans‐bpe)]PF6 photoluminescence in rigid media
Authors: Itokazu Melina Kayoko , Polo André Sarto , Iha Neyde Yukie Murakami
Published: March 2007

The excited state reactivity and photophysical properties of fac‐[Re(CO)3(phen)(     L)]PF6 (phen = 1,10‐phenanthroline, L = trans‐ or cis‐1,2‐bis(4‐pyridyl)ethylene, bpe) in PMMA (poly(methyl
methacrylate)) films have been investigated and compared with those in acetonitrile solution.

313 or 365 nm irradiation of the rhenium complex in PMMA leads to UV‐vis spectral changes due to the trans → cis isomerization of the coordinated bpe ligand. The fac‐ product presents a markedly enhanced luminescence due to a lower lying metal‐to‐ligand charge transfer (MLCT) excited state
in the cis isomer. This emitting property can be conveniently applied as a probe or sensor.

The cis is omer ratio in the photostationary state (PSS) is substantially smaller in solid films than in solution.
The photochemical behavior of the free trans‐1,2‐bis(4‐pyridyl)ethylene in PMMA is also reported to establish
comparisons with the investigation carried out in acetonitrile solution as well as with the behavior of the
coordinated ligand.
Photophysical properties of two novel tetraphenylporphyrins substituted by guanidiniocarbonyl and monocyclic guanidine groups
Authors: Kubát Pavel , Lang Kamil , Král Vladimír , Schmidtchen Franz P.
Published: March 2007

Photophysical properties of two novel guanidiniocarbonyl (I) and monocyclic guanidine (II)
tetraphenylporphyrins and their interaction with DNA were investigated by steady‐state and time‐resolved
absorption and emission spectroscopies. I stays predominantly monomeric in aqueous solutions. It produces
singlet oxygen with high quantum yield (ΦΔ = 0.67) that is typical for monomeric porphyrins. The electronic
absorption spectra of I are not influenced by interaction with DNA. This is in contrast with monomeric tetratolylporphyrins
bearing phosphonium,ammonium and pyridinium groups where the formation of stable
complexes with DNA is accompanied by a characteristic red shift of the Soret band. II extensively forms Hand
J‐aggregates,which do not produce singlet oxygen (ΦΔ < 0.01). In the presence of DNA only a small
fraction of II remains in monomeric form that is bound to DNA exterior.
Photochemical reactions of metal nitrosyl complexes. Mechanisms of NO reactions with biologically relevant metal centers
Authors: Ford Peter C.
Published: March 2007

The discoveries that nitric oxide (a.k.a. nitrogen monoxide) serves important roles in mammalian
bioregulation and immunology have stimulated intense interest in the chemistry and biochemistry of NO
and derivatives such as metal nitrosyl complexes. Also of interest are strategies to deliver NO to biological
targets on demand. One such strategy would be to employ a precursor which displays relatively low thermal
reactivity but is photochemically active to release NO. This proposition led us to investigate laser flash
and continuous photolysis kinetics of nitrosyl complexes such as the Roussin′s iron‐sulfur‐nitrosyl cluster
anions Fe2S2(NO)42− and Fe4S3(NO)7− and several ruthenium salen and porphyrin nitrosyls. These include
studies using metal‐nitrosyl photochemistry as a vehicle for delivering NO to hypoxic cell cultures in order to
sensitize γ‐radiation damage. Also studied were the rates and mechanisms of NO “on” reactions with model
water soluble heme compounds, the ferriheme protein met‐myoglobin and various ruthenium complexes
using ns laser flash photolysis techniques. An overview of these studies is presented.
Transition metal doped TiO2: physical properties and photocatalytic behaviour
Authors: Paola A. Di , Ikeda S. , Marcì G. , Ohtani B. , Palmisano L.
Published: March 2007

Two probe photocatalytic reactions, i.e. ethanoic acid and 4‐nitrophenol photooxidation, were
carried out in different experimental conditions by using suspensions of transition metal (Co, Cr, Cu, Fe,
Mo, V and W) doped polycrystalline TiO2 powders in aqueous systems. A beneficial influence of the presence
of metal species was observed only with the samples containing copper and tungsten. In particular,
the TiO2/Cu powders showed to be more photoactive of bare TiO2 for the ethanoic acid oxidation while the
TiO2/W samples were more efficient for 4‐nitrophenol degradation. A tentative interpretation is provided
on the basis of the values of the points of zero charge of the powders and of the rate constants of recombination
of photogenerated electrons and holes, determined by femtosecond pump‐probe diffuse reflectance
spectroscopy (PP‐DRS).
Photoredox reactions of environmental chromium
Authors: Mytych Piotr , Cieśla Paweł , Stasicka Zofia
Published: March 2007

The role of direct photochemical reactions of Cr(VI) and Cr(III) species in the environmental
degradation of organic matter was investigated by means of Cr(VI)/alcohol and Cr(III)/EDTA model systems
under conditions mimicking the environmental ones. Photoreduction of Cr(VI) proceeds through reductive
quenching of chromate(VI) excited within UV‐A by an alcohol molecule. Although HCrO4 − is more susceptible to the quenching than the CrO4 2− ion, and oxygen favours the reverse reaction, the reduction can be easy noticeable at air‐saturated natural waters. Photoredox behaviour of [crEDTA(L)]n- is more complex: it is initiated also by photoreduction, Cr(III) Cr(II), which at alkaline medium and a large excess of O2 over Cr(II) is followed by the Cr(II) → Cr(VI) oxidation. Both the photoreductions are accompanied by oxidation
of organic matter. Due to the substitutional lability of the [crEDTA(L)]n- complexes the conditions can be
adjusted under which the Cr(VI)/Cr(III) forms are able to mediate the O2 oxidation of organic matter in the
environmental photocatalytic cycle.
Importance of a role of (EuN3)2+ complex generated in the Eu3+/N3-/H2O2 system studied by the chemiluminescent method
Authors: Staninski K. , Kaczmarek M. , Lis S. , Elbanowski M.
Published: March 2007

Chemiluminescence has been studied in the systems containing hydrogen peroxide H2O2 and Eu3+ and ions. Ultraweak emission lasting for a few tens of hours has been observed. The dominant bands
in the spectral distribution of the chemiluminescence are those of λ = 594 and 620 nm,which proves that
excited Eu3+ ions are the only emitters in the system. As follows from measurements of chemiluminescence
intensity for different pH of the solution and concentration of F- ions,introduced as ligands competitive to
,it is in direct proportion to the concentration of the complex forming in the solution.
Photoexcitation in thin films deposited on silicon substrates by reactive pulsed laser ablation
Authors: Guidoni A. Giardini , Marotta V. , Orlando S. , Parisi G. P.
Published: March 2007

Reactive pulsed laser ablation is a very interesting method to deposit thin films of several
materials and compounds such as oxides, nitrides, semiconductors and superconductors. This technique
relies on photoablation of pure elements, or a mixture of materials, with simultaneous exposure to a reactive
atmosphere. In the case of oxides, reactions between the laser vaporized metals and oxygen lead to the
formation of intermediate complexes and finally to oxide thin films. The reactivity of the plume has been
already studied by our group in other oxides and nitrides productions and ascertained by Time of Flight
Mass Spectrometry measurements [1].

Thin films of semiconducting oxides such as In2O3, SnO2, and multilayers of these two compounds have
been deposited by Reactive Pulsed Laser Ablation, with the aim to evaluate the behaviour of such films under
variable halogen lamp illumination.

Deposition of these thin films has been carried out by a frequency doubled Nd‐YAG laser (wavelength = 532 nm) on Silicon (100) substrates. A comparison, among indium oxide, tin oxide, and multilayers of indium
and tin oxides, has been performed. The influence of physical parameters, such as substrate temperature
and oxygen pressure in the deposition chamber, has been investigated. The deposited films have been characterized
by Electric Resistance measurements.
Photochemical R2PI study of chirality and intermolecular forces in supersonic beam
Authors: Guidoni A. Giardini , Piccirillo S. , Scuderi D. , Satta M. , Di Palma T. M. , Speranza M. , Filippi A. , Paladini A.
Published: March 2007

One and two‐color, mass selected R2PI spectra of the S1 ← S0 transitions in the bare (+)-(R)-
1-phenyl-1-ethanol (ER) and its complexes with different solvent molecules (solv) (‐)‐(R)-2-butanol (BR)
or (+)-(S)-2-butanol (BS), (—)‐(R)-2-pentanol (TR) or (+)-(S)-2-pentanol (
TS) and (-)-(R)-2-butylamine (AR) or
(+)-(S)-2-butylamine (AS), have been recorded after a supersonic molecular beam expansion. The one‐color
R2PI excitation spectra of the diastereomeric complexes are characterized by significant shifts of their band
origin relative to that of bare ER. The extent and the direction of these spectral shifts are found to depend
upon the structure and the configuration of solv and are attributed to different short‐range interactions in
the ground and excited states of the complexes. In analogy with other diastereomeric complexes, the phenomenological
binding energy of the homochiral cluster is found to be greater than that of the heterochiral
one. Preliminary measurements of excitation spectrum of (+)-(R)-1-Indanol (IR) is also reported.
Spectroscopy in heterogenous media and applications for bioprocess and environmental monitoring
Authors: Schael Frank , Reich Oliver , Engelhard Sonja
Published: March 2007

Diffuse reflectance measurements and photon migration studies with near infrared (NIR) diode
lasers were employed to elucidate experimental methods for determining absorption and scattering coefficients
and species concentrations in heterogenous media. Measurements were performed at a number of
wavelengths utilizing several laser sources some of which were widely tunable. In order to establish the
applicability of simple photon migration models derived from radiation transport theory and to check the
experimental boundary conditions of our measurements, simple light scattering solutions (such as suspensions
of titanium dioxide, latex particles, and solutions of milk powder) containing dyes (such as nile blue,
isosulfan blue) were investigated. The results obtained from diffuse‐reflectance studies at different sourcedetector
distances were in accordance with predictions from simple photon diffusion theory. Applications
of reflectance measurements for monitoring of cell growth during fermentation processes and for in-situ
investigations of soils are presented.
Photoinduced reactions in zeolites: kinetic motion, environment, and charge stabilization
Authors: Thomas J. K.
Published: March 2007

Photophysical and photochemical methods are used to examine the interior surfaces of zeolite X
and Y. These methods are also used to examine the effect of co‐adsorbed solvent molecules on photo‐induced
processes in these zeolites. In particular, the effect of solvent on the diffusive motion in and between the
zeolite cages is illustrated. Finally, the unique charge trapping and charge stabilization of the zeolite is
shown.
Environmental photocatalytic processes with POM. The photodecomposition of atrazine and photoreduction of metal ions from aqueous solutions
Authors: Hiskia A. , Troupis A. , Papaconstantinou E.
Published: March 2007

Polyoxometalate anions (POM), resulting from the condensation of tungstate anions in strongly
acidified solutions, can absorb efficiently light in the UV‐near Vis region.The produced excited state is a very
powerful oxidative reagent which can, mainly via OH radical attack, oxidize and mineralize a great variety
of organic pollutants in aqueous solutions, while the photocatalytic circle is closed by reoxidation of the
reduced POM, mainly, by O2. Metal ions can also serve as oxidants and close the photocatalytic cycle. In the
process metal ions are reduced, precipitated and removed from the solution. Thus photocatalytic treatment
for decontamination of waste waters from both organic and inorganic pollutants (metal ions) can be, in
principle, achieved.

Atrazine, a widely used herbicide with s‐triazine structure, is photodecomposed to cyanuric acid in presence
of
in aqueous solutions. However, no precipitation of metal ions is obtained when atrazine is the
sole organic substrate in aqueous solutions. The low solubility of atrazine produces insufficient concentration
of reduced POM to cause precipitation.
Laser‐induced degradation of organophosphorus compounds
Authors: Trebše Polonca , Franko Mladen
Published: March 2007

The object of our research has been laser‐induced photo‐oxidation of organophosphorus compounds
in aqueous media. A XeCl excimer laser with a pulse energy of up to 150 mJ and wavelength of
308 nm has been used as a light source. The research comprised the influence of irradiation conditions on
pesticide degradation (number of laser pulses, pulse energy) and decomposition efficiency. The time between
irradiation and sample isolation ranged from 5 min to 24 hrs. Rapid decomposition has been achieved within
two hours following the irradiation for the range of concentrations limited by the solubility of pesticide
(up to 40 mgL-1). 1 mL samples required less than 120 mJ of total irradiation energy at 308 nm, which was
delivered to the sample in time intervals shorter then 1 second when catalysts, such as titanium dioxide
and hydrogen peroxide were applied. Similar degradation efficiency was also obtained without the addition
of catalysts when higher irradiation energies were used. The compounds detected in the irradiated samples
suggest that diazinon is converted directly into 2‐isopropyl‐4‐methyl‐6‐hydroxypyrimidine without the formation
of more toxic diazoxon. This transformation involves oxidation of the sulphur atom to the sulphate
anion.
Interaction of a new antiviral and antitumor photosensitizer hypericin with human serum albumin: molecular modeling study
Authors: Hritz Jozef , Ulicny Jozef , Miskovsky Pavol
Published: March 2007

Molecular modeling has been employed to study the interaction of hypericin (Hyp) with human
serum albumin (HSA). The structural model for Hyp/HSA complex is presented. Our results indicate that
Hyp is bound in II A subdomain of HSA close to the tryptophan 214 (Trp214) (distance 5.12 Å between the
centers of masses). In the presented model the carbonyl group of Hyp is hydrogen bonded to the Asn458.
Another two candidates for hydrogen bonds have been identified between the bay‐region hydroxyl group of
Hyp and the carbonyl group of the Trp214 peptidic link and between the peri‐region hydroxyl group of Hyp
and Asn458 carbonyl group.
The fluorescence analysis of laser photolysis of phenols in water
Authors: Tchaikovskaya O. , Sokolova I. , Bazyl O. , Swetlichnyi V. , Kopylova T. , Mayer G. , Sultimova N.
Published: March 2007

Photolysis of phenol and p‐chlorophenol exposed to KrCl‐ and Nd‐YAG laser light is studied
by electron spectroscopy and fluorescence and quantum chemical techniques. The decrease of the quantum
yield of phenol fluorescence with increase in the excitation energy is not related to dynamic changes in
the intramolecular photophysical processes; rather this is a result of increased photoreaction efficiency.
Chlorine substitution for para‐state of phenol is shown to strengthen the OH‐bond in excitation into the
long wavelength absorption band.
Degradation of chlorinated benzaldehydes in aqueous solutions by UV‐irradiation
Authors: Bekbölet Miray , Getoff Nikola
Published: March 2007

Photoinduced degradation of chlorinated benzaldehydes was investigated using UV light with
λ = 253.7 nm in aerated aqueous solutions. Substrate degradation rate as expressed by first order reaction
kinetics revealed rate constants, k; 7.45 × 10−3 min-1, 3.90 × 10−3 min-1 and 3.90 × 11−2 min-1 for 2‐
chlorobenzaldehyde, 3‐chlorobenzaldehyde and 4‐chlorobenzaldehyde respectively. The decomposition of
the substrates was related to the formation of chloride and formaldehyde by homolytic cleavage processes.
initial quantum yields and photochemical “ ‐values” are reported for the degradation of the substrates.
Based on the qualitative HPLC analysis, a probable reaction mechanism for the photoinduced degradation
of chlorinated benzaldehydes is also presented.
Liquid and frozen multilayers of decanol in zeolites as microreactors for direct and oxygen mediated triplet‐triplet annihilation of porphyrin
Authors: Levin Peter P. , Costa Silvia M. B.
Published: March 2007

The kinetics of triplet state decay and concomitant delayed fluorescence of tetraphenylporphyrin
(TPP) incorporated into the multilayers of n‐decanol adsorbed on the external surface of zeolites at different
temperatures were studied by the laser flash photolysis via monitoring the emission and diffuse‐reflectance.
In deoxygenated samples, the kinetics of diffusion‐controlled bimolecular triplet‐triplet annihilation (TTA)
has been used to probe the multilayers. A very large local concentration of reactants may be obtained using
small bulk amounts. A fast TTA rate constant demonstrated the triplet energy migration in TPP assemblies
formed at the liquid/solid interface. The TTA in aerated samples is mediated by molecular oxygen leading
to 1O2 feedback—induced delayed fluorescence. Singlet oxygen works as an efficient mobile energy carrier
between TPP triplets. The parameters of both TTA may be modified by multilayer, which acts as microreactor
with supramolecular organization. The freezing of n‐decanol results in dramatic apparent acceleration of
both direct and 1O2 mediated TTA due to the increase in local TPP concentration because of displacement
of TPP molecules into the residual liquid domains in polycrystalline matrix. The concentration of TPP in
those microreactors can be three orders of magnitude larger than the solubility limit in a particular neat
liquid solvent demonstrating the unique features of solid solution, which seems to be due to the presence
of crystal/liquid interfaces.
Incorporation of silver (I) ions within zeolite cavities and their photocatalytic reactivity for the decomposition of N2O into N2 and O2
Authors: Ju Woo-Sung , Matsuoka Masaya , Anpo Masakazu
Published: March 2007

Ag+/ZSM‐5 catalysts were prepared by an ion‐exchange method. UV‐irradiation of the Ag+/ZSM‐5 catalysts in the presence of N2O led to the photocatalytic decomposition of N2O into N2 and O2 at 298 K. Investigations of the effective wavelength of the irradiated UV‐light for the reaction as well as the in‐situ
characterization of the catalysts by means of UV‐Vis, photoluminescence and FT‐IR spectroscopies revealed
that the photoexcitation of the Ag+ ‐ N2O complexes formed between gaseous N2O and the isolated Ag+ ions exchanged within the zeolite cavities plays a significant role in the reaction.
Photooxidation of ethylene over Cu‐modified and unmodified silica
Authors: Ichihashi Yuichi , Matsumura Yasuyuki
Published: March 2007

Silica catalyzes photooxidation of ethylene to carbon dioxide and modification of copper on silica
results in the lower reaction rate and partial production of ethylene oxide. The reaction does not proceed
by the light irradiation through a color filter (λ > 280 nm). ESR measurement indicates that radical oxygen
species assignable T‐shape Si ‐ O3 − can be produced on silica by UV irradiation at 77 K. The same species
are also found on silica modified with copper by UV irradiation while the quantity is smaller. When silica
and silica modified with copper are UV‐irradiated in presence of oxygen and ethylene at 77 K, formation of
methyl radicals is confirmed only on silica while ethyl radicals are observed with both samples. We suggest
that copper stabilizes C2 species and prevents cleavage of C ‐ C bonding.
Photocatalytic oxidation of fuel oxygenated additives in aqueous solutions
Authors: Krichevskaya M. , Kachina A. , Malygina T. , Preis S. , Kallas J.
Published: March 2007

Experimental research of photocatalytical oxidation (PCO) of aqueous solutions of de‐icing
agents (ethylene glycol and ethylene glycol monoethyl ether) and methyl tert‐butyl ether (MTBE) was undertaken.
These chemicals are water‐soluble components of jet and motor fuels accidentally disposed to
the environment. Titanium dioxide (Degussa P25) under near‐UV irradiation was selected as a photocatalyst.
A slightly acidic medium was preferable for the process efficiency for MTBE, whereas a neutral medium
was beneficial for de‐icing agents and jet fuel aqueous extracts. TiO2 suspension fractional composition was found to be dependent on pH and the presence of organic admixtures: the minimum size of TiO2 particles at their maximum uniformity was established in an acidic medium, where the efficiency of PCO of
de‐icing agents was the poorest. On the other hand, neutral and slightly acidic media, beneficial for PCO efficiency,
were favourable for particle agglomeration, which indicates a minimal role for photocatalyst particle
size in PCO efficiency. PCO efficiency increased with increasing MTBE and icing inhibitor concentration. The
biodegradability of aqueous solutions of oxygenated additives increased as PCO proceeded. The influence
of mineral additives—sulphate, calcium, ferric and manganese ions—on the process efficiency was found to
be complex. Special attention was paid to energy‐saving PCO with a photocatalyst attached to buoyant glass
micro‐spheres and reduced intensity of stirring of the slurry.
TiO2 thin film synthesis from complex precursors by CVD, its physical and photocatalytic properties
Authors: Besserguenev V. G. , Pereira R. J.F. , Mateus M. C. , Khmelinskii I. V. , Nicula R. C. , Burkel E.
Published: March 2007

Photocatalytic TiO2 films on glass and quartz plates were obtained by the chemical vapour
deposition using Ti(dpm)2(Opri)2 complex compound (CC‐CVD method) in a standard vacuum apparatus
at 1.2–2.0 × 10‐4 mbar. The substrate temperature was stabilised in the range of 450–600 ∘C. The growth rate varied from several nanometres to several dozen of nanometres per minute. Structural information on
TiO2 thin films was obtained from synchrotron radiation experiments. High‐resolution grazing incidence
X‐ray diffraction (GIXRD) experiments were performed at the high‐resolution powder diffractometer at the
DESY/HASYLAB beamline B2 (Hamburg, Germany). Thin films deposited on either single‐crystal Si wafers
or on amorphous quartz substrates were analysed. The photocatalytic activity of the TiO2 thin films was
studied using a photocatalytic reactor. The fungicide Fenarimol was chosen as chemical indicator and its
degradation kinetics was followed by High‐Performance Liquid Chromatography (HPLC).
Photoelectrochemical properties of sol‐gel and particulate TiO2 layers
Authors: Waldner Georg , Krýsa Josef , Jirkovský Jaromír , Grabner Gottfried
Published: March 2007

Polarization curves on irradiated TiO2 layers were measured in various electrolytes, namely
sodium hydroxide, sulphuric acid, oxalic acid and potassium oxalate. Photocurrents measured in 0.1M NaOH
are very small and decrease with increasing number of Degussa P25 TiO2 layers. Photocurrents for sol‐gel
TiO2 layers in 0.1M NaOH are about five times higher than for P25 TiO2 layers and increasing with number
of layers. The same holds for Na2SO4, but in H2SO4 the difference between P25 and sol‐gel diminishes,
however the sol‐gel layers still show the higher currents. In solutions of oxidizable substrates the trend is
inversed: P25 layers show higher currents, with a steep increase with concentration of solute. The shape of
the polarization curves was interpreted in terms of response time to irradiation and photocurrent depletion.
Degradation experiments demonstrated that the effect (and advantage) of biasing the electrode depends on
adsorption properties of substance and surface area of electrode material.
Elaboration and characterization of environmental properties of TiO2 plasma sprayed coatings
Authors: Toma L. , Keller N. , Bertrand G. , Klein D. , Coddet C.
Published: March 2007

Titanium dioxide (TiO2) is an attractive material for numerous technological applications such
as photocatalytical applications. These materials can in some conditions have the ability to allow the environmental
purification of air and water by the decomposition and removal of harmful substances, such as
volatile organic compounds (VOC), benzene compounds, NOx, SO2, etc. Our work was focused on the elaboration
and the evaluation of the environmental properties of titanium dioxide coatings by plasma spray
techniques. The principle of plasma spraying consists by the injection in an enthalpic source (plasma) of the
powder of one material to be sprayed. The molten powder is transported and accelerated by the plasmaproducing
gas flow and crushed on the target substrate, where the particles of material solidify with high
speeds, thus forming the coating. The advantages of thermal spraying consist in the fact that the coating has
stability, durability, adherence and cohesion. For this study, the initial powder material was an anatase TiO2.
The photocatalyst coating was realized by a few kinds of thermal spray method: gas flame, APS (atmospheric
plasma), VPS (vacuum plasma) and HVOF (high velocity oxygen fuel). The microstructures of the deposits, as
a function of the coating process, are analysed by optical microscopy, scanning electronic microscopy, and
the X‐rays diffraction. To carry out the step of validation of these surfaces for their environmental functionalities,
we used a control test process for the photocatalytic effectiveness with respect to nitrogen oxides.
For that an original test chamber has been developed. Ultraviolet rays irradiated the coating specimens and
the efficiency of NOx elimination has been controlled using a gas analyser. We studied the photocatalytical
properties of different obtained coatings as a function of various parameters (porosity, thickness, ratio
anatase/rutile).