bluuebunny/crossref_metadata_2025 huggingface dataset:
Laboratory‐scale photomineralisation of n‐alkanes in aqueous solution, by photocatalytic membranes immobilising titanium dioxide
Authors: Bellobono Ignazio Renato , Morazzoni Franca , Bianchi Riccardo , Mangone Emilia Simona , Stanescu Rodica , Costache Cristina , Tozzi Paola Maria
Published: March 2007

Kinetics of photocatalytic oxidation of methane, ethane, n‐heptane, n‐decane, and n‐dodecane, to yield intermediates, and photomineralisation of intermediates, to yield carbon dioxide and water, was
studied in aqueous solution, by a laboratory‐scale photoreactor and photocatalytic membranes immobilizing 30 ± 3 wt.% of TiO2, in the presence of stoichiometric hydrogen peroxide as oxygen donor. The whole volume
of irradiated solution was 4.000 ± 0.005 L, the ratio between this volume and the geometrical apparent
surface of the irradiated side of the photocatalytic membrane was 3.8 ± 0.1 cm, and the absorbed power
0.30W/cm (cylindrical geometry). A kinetic model was used, by which mineralisation of substrate to CO2 was supposed to occur, by kinetic constants k1, through one single intermediate, mediating the behaviour
of all the numerous real intermediates formed in the path from the substrate to CO2 (kinetic constants of
formation of the latter being k2). A competitive Langmuirian adsorption of both substrate and “intermediate”
was also supposed to be operative, as expressed by apparent adsorption constants k1 and k2, possessing a, partly at least, kinetic significance. By Langmuir‐Hinshelwood treatment of initial rate data, starting values
of the k and K couples were obtained, from which, by a set of differential equations, the final optimised
parameters, k1 and k1, k2 and K2, were calculated, able fit the whole photomineralisation curve, and not only
its initial segment, as the Langmuirian parameters do. The parameters of present work are critically compared
with those obtained in two preceding set of studies relative to n‐alkanoic acids and to n‐alkanols. They are
interpreted on the basis of a closer behaviour of hydrocarbons to alkanols, from the photocatalytic point
of view, than to carboxylic acids are. Discussion of limiting effective quantum yields, and their comparison
with maximum, theoretical values, are also carried out.
Solar energy driven photocatalytic membrane modules for water reuse in agricultural and food industries. Pre‐industrial experience using s‐triazines as model molecules
Authors: Bellobono Ignazio Renato , Morazzoni Franca , Bianchi Riccardo , Mangone Emilia Simona , Stanescu Rodica , Costache Cristina , Tozzi Paola Maria
Published: March 2007

A membrane module, utilizing photocatalytic membranes, has been employed in a pilot plant,
in conditions of solar irradiation, to investigate photomineralisation of atrazine, propazine, terbutylazine,
symazine, prometryn, and ametryn, as model molecules of s‐triazine herbicides, at a standard concentration
(1.0 ppm) simulating those of contaminated aquifers, by using ozone as oxygen supplier. Photocatalytic
composite membranes immobilised 30 ± 3 wt.% of TiO2 and 6 wt.% of a synergic mixture of tri‐(t‐butyl)‐ and tri‐(i‐propyl)vanadate(V). Photomineralisation was followed by analysis of substrate disappearance, as such, and by total organic carbon (TOC) analysis. A four parameters kinetic model was employed, as set up in previous studies of this series, to interpret the whole photomineralisation curve. Quantum yields,
as indicative of catalytic and photocatalytic mechanisms, were evaluated satisfactorily: they are discussed,
and compared with those of previous studies on the same substrates, carried out in the same module, but
in conditions of practically monochromatic irradiation (254 nm) within the range of optical absorption of
semiconductor. Finally, in order to compare effectiveness of composite photocatalytic membranes, described
above, prepared by photografting, either in the presence or in the absence of an added photopromoter, as
well as that of metallic membranes, onto which the semiconductor without any photopromoter was present
as a 3–4 μm thick surface layer, directly produced on the nanotechnologically treated surface, with those of
other commercial materials, parallel experiments were carried out, by using commercial sheets in which the
semiconductor was immobilised, by a method based substantially on glueing by colloidal silica. All of these
comparison experiments were carried out at a laboratory scale, by using, in these experiments, dioxygen of
air, or ozone as oxygen donors.
The interaction and photostability of some xanthenes and selected azo sensitizing dyes with TiO2 nanoparticles
Authors: EL Mekkawi D. , Abdel-Mottaleb M. S. A.
Published: March 2007

We have tested simple Graetzel‐type solar cells using semiconductor thin films consisting of
TiO2 nanoparticles and some electron injecting dyes. The possibility of using xanthenes (rhodamine 101,
fluorescein and 5(6)‐carboxyfluorescein) and selected azo dyes (alizarin yellow R, alizarin yellow 2G and
carboxyaesenazo) as sensitizers has been explored. Fluorescence and electronic absorption measurements
revealed complex formation between the chosen dyes and the surface of the colloidal TiO2. The apparent association constants (Kapp) of the surface complexes have been estimated and are correlated with the dyeinduced
negative shifts of the reduction potential of colloidal TiO2 nanoparticles. Moreover, due to its utmost
importance, photostability of the organic dyes in absence and presence of colloidal TiO2 nanoparticles and the influence of the used electrolyte have been examined. The results point to a remarkable enhancement of
photostability in the presence of the electrolyte (I3 −/I −), which is attributed to fast regeneration of the neutral
dye via the redox couple of the electrolyte. Furthermore, photocurrent action spectrum of the fabricated and
tested DSC shows the origin of photoelectric output to be optical absorption of the dye used.
Long‐lived Charge‐Transfer States in 9‐Aryl‐Acridinium Ions; A Critical Reinvestigation
Authors: Verhoeven Jan W. , Ramesdonk Hendrik J. van , Zhang Hong , Groeneveld Michiel M. , Benniston Andrew C. , Harriman Anthony
Published: March 2007

In the recent literature a simple 9‐aryl‐acridinium ion was claimed to undergo an intramolecular,
photoinduced charge shift to produce an extremely long‐lived and very high energy charge‐transfer state. The
possible consequences of this observation are discussed and the tenability of the claims made is investigated
via time resolved spectroscopy of a closely related system with spectroscopic characteristics allowing more
solid identification of the actual photophysical events taking place. From the results obtained it appears
likely that the long‐lived species observed earlier in solution cannot be charge transfer in nature but must
instead be identified as the lowest triplet state of the acridinium chromophore.
Charge transfer control by substituents: Donor pyrroles and fluoro‐anilines
Authors: Neubauer Antje , Murali Sukumaran , Rettig Wolfgang
Published: March 2007

Derivatives of N‐phenyl pyrrole with a para‐donor substituent on the acceptor benzene ring are
compared. It is shown that by a suitable increase of the donor strength of the pyrrolo group, CT fluorescence
can be achieved even for donor‐donor substituted benzenes. On the other hand, introducing fluoro
substituents into the acceptor moiety strongly enhances the CT formation tendency, and several new compounds
with CT fluorescence even in alkane solvents are presented.
Effects of chromophore interaction in the spectroscopy of ketocyanine dyes with a central pyranone or pyridone fragment
Authors: Shvedova Ludmila A. , Tatikolov Alexander S. , Sklyarenko Vladimir I. , Krasnaya Zhanna A.
Published: March 2007

The study is devoted to investigation of a number of ketocyanine dyes (polyenic ω,ω′‐bisaminoketones) with a central pyranone or pyridone fragment and respective polymethine salts by UV‐VIS
absorption and NMR spectroscopies. It was found that replacement of bridging O atom with NMe group
suppresses the chromophore interaction in the cross‐conjugated ketone and corresponding tridecamethine
salt. Furthermore, incorporation of meso‐amino substituent into the polymethine chain of the salts with
the central pyrylium fragment sharply decreases the chromophore interaction. In spite of dramatic differences
between the absorption spectra of the ketocyanines containing O‐ or NMe‐ bridging fragment, 13C NMR spectra of these dyes are similar. A comparison of the differences between the chemical shifts of adjacent
polymethine carbon atoms in the 13C NMR spectra for these dyes point to stronger alternation of charges
along the polymethine chain and, consequently, stronger chromophore interaction for the dye with the central
pyrylium cycle. Flash photolysis experiments showed photoisomerization of the dyes with NMe bridging
group to form long‐lived isomeric form.
Energy transfer process in the reaction system NH2OH‐OH‐NaOH‐CU(II) − Eu(III) / thenoyltrifluoroacetone
Authors: Lis Stefan , Kaczmarek Małgorzata
Published: March 2007

Chemiluminescence (CL) in the system containing hyrdroxylamine, sodium hydroxide, copper(II)
ions and complex of europium(III) with thenoyltrifluoroacetone has been studied. A weak emission arises
from hydroxylamine in the presence of copper(II) ions in a basic aqueous solution. Addition of europium(III)
chelate to this system causes a significant increase in the chemiluminescence intensity. The dominant band
observed in the emission spectrum occurs at λ∼ 600 nm, confirming that Eu(III) ions are the only emitters in the system studied. A strong correlation between the CL intensity and the concentrations of europium(III) chelate was observed. It means that europium(III) thenoyltrifluoroacetone complex does not influence the
oxidation rate of hydroxylamine and indicates its important role in this reaction as a sensitiser. A possible
mechanism of the chemiluminescence of the NH2OH‐OH‐NaOH‐CU(II) − Eu(III) chelate system is presented.
Photophysical characterization of chosen Ln(III) macromolecular complexes
Authors: Staninski Krzysztof , Lis Stefan
Published: March 2007

Spectral characterization of N,N′‐Bis(2,4‐dihydroxobenzylidene)1,2‐diaminobenzene (DHDA)
complexes with chosen f‐ and d‐metal ions are described. Physico‐chemical properties of a series of complexes
were studied in methanol solution using UV‐VIS, IR and fluorescence spectroscopy. It was found that
the excitation and fluorescence spectra of DHDA in water and methanol after being exposed to ultraviolet
radiation, show very obvious photochromism. The formation of 1: 1 complexes between 4, 4′, 4″, 4‴‐(porphine‐5,10,15,20‐tetrayl)‐tetrakis benzoic acid, (TCPPH2) and La(III), Eu(III) and Yb(III) in methanolic solution, with the use of the spectrophotometric and spectrofluorimetric methods. The conditional stability constants of the complexes were studied by monitoring the spectral changes of energy and intensity of Q
bands of the porphyrin.
The influence of ferrous ions on the efficiency of aqueous photocatalytic oxidation of 2‐ethoxy ethanol
Authors: Klauson D. , Preis S.
Published: March 2007

The complex influence of ferrous ions on the efficiency of aqueous photocatalytic oxidation (PCO)
of 2‐ethoxyethanol (2‐EE) was examined. A drastic efficiency increase at lower concentrations of ferrous ions
was observed to change to a sharp decrease at higher concentrations. An explanation was proposed for the
observed phenomena based on the low sensitivity of the pollutant towards radical‐oxidation reactions and
the competitive adsorption of metallic ions and 2‐EE on the TiO2 surface.
Structure and spectra of photochemically obtained nanosized silver particles in presence of modified porous silica
Authors: Krylova Galina , Eremenko Anna , Smirnova Natalia , Eustis Susie
Published: March 2007

Mesoporous silica powders and films modified with organic sensitizer benzophenone were used
as photocatalysts in the reaction of silver ion reduction by isopropyl alcohol under UV‐irradiation with λ = 253.7 nm and 365 nm in presence of colloidal silica as stabilizer. Morphological changes of silver colloids
during irradiation were studied using transmission electron microscopy, and correlated to the absorption
spectra.
Light and drugs: the photochemistry of fluoroquinolone antibiotics
Authors: Fasani Elissa , Albini Angelo , Mella Mariella , Rampi Michela , Negra Federico Barberis
Published: March 2007

Light‐related adverse side‐effects of drugs are now an important source of concern. In order that the mechanism underlying to such effects is recognised, an in‐depth photochemical study must be carried out. The case of some fluoroquinolone antibiotics (norfloxacin, enoxacin, lomefloxacin) is discussed as a representative example. These drugs undergo heterolytic fragmentation of the C—F bond leading to aryl cations. Quantum yields in neutral water range from 0.001 to 0.5 depending on the charge transfer degree of the ππ* state. Lower values are obtained at both acidic and basic pH. There is indication that the excited state involved in most of this reactions is a relatively long‐lived triplet. The aryl cations undergo intra‐ or intermolecular reactions, and are presumably involved in the reported photo‐toxic effect.
Complex formation between 3;3´‐diethylthiacarbocyanine iodide and DNA and its investigation in aqueous solution
Authors: Anikovsky M. Y. , Tatikolov A. S. , Kuzmin V. A.
Published: March 2007

The binding of 3;3′‐diethylthiacarbocyanine iodide (DTCC) with molecules of DNA was investigated
by different photochemical methods. Absorption spectra were investigated under various concentration
of DNA. Isosbestic points observed in these spectra are attributable to existence of two different
complexes DTCC with DNA. Equilibrium constants of the formation of complexes I and II were determined
(K1 ≈ 106M−1, K2 ≈ 5 × 104M−1 accordingly). Differential absorption spectra of two photoisomers of DTCC
were obtained by flash photolysis method; it was found that the quantum yield of the short‐lived photoisomer
decreases and the quantum yield of the second long‐lived photoisomer builds up with the increase in
the DNA concentration. Kinetics of interaction between the triplet state of the dye and oxygen were investigated
under various concentration of DNA. The growth of the quantum yield of fluorescence and intersystem
crossing was observed with the increase in the DNA concentration.
Photooxidation of sulfide, thiol, phenols, and cyclopentadiene by artificial light and solar light irradiation
Authors: Gerdes Robert , Bartels Oliver , Schneider Gerhard , Wöhrle Dieter , Schulz-Ekloff Günter
Published: March 2007

The photooxidations of the toxic products sulfide, 2‐mercaptoethanol and phenols under partial
mineralisation in aqueous alkaline solution and the photooxidation of cyclopentadiene in ethanol in order to
produce fine chemicals is described. Because the employed photosensitizers such as metal phthalocyanines,
a tetraphenylporphyrine, rose bengal or methylene blue absorb in the visible region of light, an inexpensive
slide projector was used under laboratory conditions.

Experiments under solar radiation were carried out by concentrating the solar light with a reflective satellite
bowl. The oxygen consumption over time is measured with a gas burette. The formation of singlet oxygen
by energy transfer from the excited photosensitizer followed by oxidation of the substrates is responsible
for the photoinduced oxidations. The applicability of the experimental conditions described here for other
visible and solar light driven oxidation reactions is obvious.
Ultrasonic enhancement of photo‐catalytic oxidation of surfactant
Authors: Suzuki Yasuyuki , Waristo  , Arakawa Hiroki , Maezawa Akinori , Uchida Shigeo
Published: March 2007

Photo‐catalytic oxidation of surfactant (polyoxyethylene‐alkyl‐ether, , hereinafter
referred as SS‐70) enhanced by high power ultrasound is examined. The influences of the ultrasonic
power and the stirring speed on the degradation rate are investigated. 1000 ml of 100ppm SS‐70 is decomposed

totally in about 20 minutes in the photo‐catalytic process combined with the ultrasonic irradiation.
Without ultrasonic irradiation, the decomposition needs more than 1 hour. The optimum conditions for the
hybrid degradation process are discussed. It is found that the stirring speed largely influenced the degradation
efficiency. It is considered that the catalyst particles might be localized by ultrasonic standing wave,
and caused inhibition to the decomposition in the degradation process. However, by high stirring speed, the
inhibition could be overcome.
Magnetorheological photocatalytic systems
Authors: Shchukin D. G. , Sviridov D. V. , Kulak A. I.
Published: March 2007

Preparation and properties of a novel photocatalytic system containing magnetic cores coated
with subsequently applied silica and titania shells are discussed. The underlying idea is to impart magnetic
properties to the semiconductor particles that permits to control the rheological properties of the photocatalyst
dispersion and makes possible its separation from treated solution without invoking procedures
of filtration or centrifugation. Preparation route yielding photoactive titania coating and silica interlayer,
which prevents the undesirable doping of catalyst and parasitic charge exchange between titania shell and
magnetic core, is described in detail.
Photocatalysed oxidation of cyclohexane by W10O32−4 irradiation with natural sunlight
Authors: Giannotti Charles , Richter Christoph
Published: March 2007

Using global sun UV‐emission, dioxygen, W10 as a photocatalyst in acetonitrile solution
we have performed cyclohexane oxidation. Such photooxidation was very effective and could be applied in
a large scale. The best result was obtained using 20% acetonitrile/cyclohexane emulsion and W10O32Na4 as a catalyst.
Destruction of chlorinated pesticides in TiO2‐enhanced photochemical process
Authors: Zaleska Adriana , Hupka Jan , Silowiecki Andrzej , Wiergowski Marek , Biziuk Marek
Published: March 2007

Aqueous solutions containing 200mg/dm3 of lindane, p,p´‐DDT and methoxychlor were photodegraded
for 60 min in UV/TiO2/O2 system. Sparged air was introduced into the reactor environment.
Titanium dioxide supported on glass, hollow microsphers served as the photocatalyst. Pesticides destruction
ratio was evaluated and oxidation products were identificated by gas chromatography with thermionic
specific detector (GC‐TSD) and mass spectroscopy detector (GC‐MS). The concentration of pesticides after
reaction was determined in the liquid phase, in the solid phase (adsorbed on the photocatalyst) and in the gas
phase. The experimental data indicates that pesticide removal with the gas phase was insignificant, therefore
it was neglected in the assessment of the photodegradation efficiency. From 14% to 58% of investigated
pesticides remained adsorbed on catalyst surface after photodegradation. High content of pesticides in the
solid phase after reaction resulted from their low solubility in water and indicates significant adsorption
ability of the pesticides by TiO2.
Photocatalytic degradation of some toxic analytical reagents with TiO2
Authors: Khalil M. M. H. , Abdel-Shafi A. A. , Abdel-Mottaleb M. S. A.
Published: March 2007

Photodegradation processes of two azo dyes at TiO2/H2O interface under visible and ultraviolet
light irradiation are investigated with different experimental techniques (absorption and fluorescence
spectroscopy as well as total organic carbon analysis). Measuring their fluorescence spectra monitored the
generation of some degradation intermediates. The photodegradation rate depends on dye structure and
pH of the dispersion. The rate was found to be enhanced by increasing dissolved oxygen concentrations in
the medium. The mechanism of the photodegradation process under uv‐visible light illumination involves
an electron excitation into the conduction band of the TiO2 semiconductor leading to the generation of very
active oxygenated species that attack the dye molecules leading to photodegradation.
Characterization of large area flexible plastic solar cells based on conjugated polymer/fullerene composites
Authors: Gebeyehu Desta , Padinger F. , Brabec C. J. , Fromherz T. , Hummelen J. C. , Sariciftci N. S.
Published: March 2007

The development of solar cells based on composites of organic conjugated semi‐conducting
polymers with fullerene derivatives can provide a new method in the exploitation of solar energy. Organic
solar cells must fulfill the criteria of stability, efficiency and reduction of production costs to find new
applications. Specially, the bulk donor‐acceptor heterojunctions between conjugated polymers and fullerenes
have been successfully utilized for photovoltaic devices with high carrier collection efficiency compared
to the devices made from single components. In this work we present measurements of the photovoltaic
response of bulk donor‐acceptor heterojunction between the conjugated polymer (as a donor, D) poly(3‐
octylthiophene), P3OT and fullerenes, (as acceptor, A), deposited between indium tin oxide and aluminum
electrodes. These devices are based on ultrafast, reversible, metastable photoinduced electron transfer and
charge separation.

The quality and homogeneity of composite films as well as the choice of the substrates strongly influence
the efficiency of the solar cells. One of the most important limiting factors in the performance of
this present types of molecular solar cells based on interpenetrating networks of conjugated polymers and
fullerene derivatives is the charge carrier transport in the active layer. This transport is driven by the electrical
field provided externally by the top and bottom electrodes with different work functions. We present here
efficiency and stability studies on large area (6 cm × 6 cm) flexible plastic solar cells with monochromatic
energy conversion efficiency ηe about 1.4% and carrier collection efficiency nearly 20%.
Time‐resolved reflectivity technique: improvement and applications
Authors: EL-Kader K. M. A.
Published: March 2007

A new method for determination of the reflectivity of Si in different phase transitions during
pulsed laser irradiation is presented in this paper. This method is applied on TRR spectra of crystalline silicon
(c‐Si) in a medium of oxygen and amorphous hydrogenated silicon (a‐Si: H). Time resolved reflectivity
(TRR) measurements on silicon has been made during pulsed XeCl excimer laser irradiation (308 nm, 28nm
FWHM) in a medium of oxygen. The samples were irradiated in the energy density range 400 − 100mJ/cm2.
The reflectivity was measured with a probe He‐Ne laser (632.8 nm). Depending on the energy density of the
excimer pulse, heating, melting and resolidification of the surface were monitored by TRR spectra. From
these measurements we were able to determine the melting threshold energy density for c‐Si, depending on
the energy densities, time of melting and maximum reflectivity have been measured. TRR spectra of a sample
with 3μm thick a‐Si layer for first shot of measurements were calibrated. A series of a‐Si: H samples of the
same thickness (0.34 μm) irradiated with a constant energy density 450mJ/cm2 and the three consecutive
TRR spectra of the irradiated samples were calibrated.
Recombination mechanisms in crystalline silicon: bulk and surface contributions
Authors: Susi Enrichetta
Published: March 2007

In the present paper the most interesting results of a work on the influence of some processes
used in the fabrication of microstructures on the bulk and surface electrical activity of the Si substrate are
reported. In these studies the minority carrier lifetime and the surface recombination velocity were used as
sensors of the Si electrical activity changes. Other electrical (DLTS, C-V and I-V characteristics, EBIC) and
structural (X‐ray double crystal diffractometry, IR spectroscopy) techniques were used to gather information
about the nature and concentration of the defects induced by processing.

Two processes have been investigated: Rapid Thermal Annealing treatments (RTA), and Reactive Ion Etching
(RIE): neither of them have a large influence on the minority carrier diffusion length when the substrate is
an high quality Si wafer of the last production. On the contrary, the surface recombination velocity is largely
influenced by both processes. The rearrangement of the surface structure and the formation and growth of
hillocks is proposed as the more important mechanism responsible of the observed changes in the surface
electrical activity.
Remote interfacial electron transfer processes on nanocrystalline TiO2 sensitized with polynuclear complexes
Authors: Bignozzi C. A. , Alebbi M. , Costa E. , Kleverlaan C. J. , Argazzi R. , Meyer G. J.
Published: March 2007

The kinetic study of interfacial electron transfer in sensitized nanocrystalline semiconductor is
essential to the design of molecular devices performing specific light induced functions in a microheterogeneous
environment. A series of molecular assemblies performing direct and remote charge injection to the
semiconductor have been discussed in the context of artificial photosynthesis. A particular attention in this
article has been paid to the factors that control the interfacial electron transfer processes in nanocrystalline
TiO2 films sensitized with mononuclear and polynuclear transition metal complexes.
Electrogenerated chemiluminescence of violanthrone in dimethyl sulfoxide
Authors: Hansongnern K. , Chooto P. , Amornpitoksuk P.
Published: March 2007

Violanthrone is an anthraquinone vat dye, which is resistant to photochemical damage. Most
previous work has concentrated on its chemiluminescence properties. In this report, electrogenerated chemiluminescence (ECL) of violanthrone has been investigated in dimethyl sulfoxide with 0.1M of tetraethylammonium bromide as electrolyte. Violanthrone luminesces in the potential range between 0.0V and −4 : 0 V.
At the sweep rate 1000 mV/s, the intensity of the violanthrone ECL is about 2% of that of tris(2,2′‐bipyridine) ruthenium(II) ion under the same conditions. It was found that bromine was also produced during the ex‐
periment, leading to the conclusion that the luminescence arises from the reaction between radical anion of
violanthrone and molecular bromine. The mechanism is discussed in detail.
Optical study on relaxation of excitons and initiation of photopolymerization in diacetylene crystals at low temperatures
Authors: Itoh Chihiro
Published: March 2007

Luminescence and optical absorption induced by irradiating with a pulse of 266nm laser beam
have been measured in 5,7‐dodecadiyne‐1,12‐diol bis[phenyl carbamate] (DA‐TCDU). In addition to the recombination luminescence of the lowest triplet state, luminescence from the excited single state is identified.
Irradiation with a pulse of 266 nm laser beam having the fluence above 4.4 mJcm-2 leads to formation of
series of optical absorption bands at 3.05 eV, 2.52 eV and 2.18 eV, which are ascribed to the optical transition
due to dimer diradicals, trimer diradicals and the tetramer diradicals, respectively. The laser‐fluence dependence of the integral intensity of the recombination luminescence of the singlet and the triplet exciton and
the absorption strength of the 3.05 eV band have been measured. The nature of the triplet exciton and its
relation to the initiation of the photopolymerization are discussed.
Photoinitiated azo‐hydrazo tautomerizm of 1‐p‐ toluenesulphonylazo‐2,4,6,8‐tetrakis (tert‐butyl)phenoxazine
Authors: Ivakhnenko T. E. , Makarova N. I. , Ivakhnenko E. P. , Minkin V. I. , Knyazhansky M. I.
Published: March 2007

A novel photochromic compound with NH‐N intramolecular H‐bond (1‐p‐toluenesulphonylazo‐
2,4,6,8‐tetrakis(tert‐butyl)phenoxazine) and the corresponding model structures (1‐oxo‐2,4,6,8‐tetrakis(tertbutyl)
phenoxazine, 2,4,5,7‐tetrakis (tert‐butyl )‐1‐( veratroylazo ) phenoxazine, 2,4,5,7‐tetrakis ( tert‐butyl )‐Nacetyl‐
1‐(p‐toluenesulphonylazo)phenoxazine) have been synthesized and their spectral and photochemical
properties are studied. The photochromic transformations observed are found to be conditioned by ESIPT
(as a primary step) followed by E‐Z isomerisation about N–N‐bond.
Photophysical and photochemical properties of electronically excited fluorescent dyes: a new type of time‐resolvedlaser‐scanning spectroscopy
Authors: Heupel Ma. , Gregor I. , Becker St. , Thiel E.
Published: March 2007

The capacity of a new type of time‐resolved laser‐scanning spectroscopy is discussed. Due to
the developed modulation technique we obtain a high sensitivity in the absorption measurement as well as
a very efficient suppression of the background absorption. The new technique has been used to investigate
photophysical and photochemical properties of fluorescent dyes. All presented results are discussed in view
of potential applications like dye laser and fluorescence labelling.The possibility of intermolecular triplet state quenching by molecular oxygen and further agents is considered
in detail. The quenching process is described in terms of diffusion controlled interaction. It is shown
that under ambient conditions quenching agents can inhibit the quenching by molecular oxygen and therefore
the generation of the chemically highly reactive singlet molecular oxygen. It can be expected that the
obtained information can be used in order to increase the photostability not only of rhodamine dyes.
Magnetic field modulation of the delayed fluorescenceyield in the photoionization reaction of N, N, N′, N′‐tetramethyl‐p‐phenylenediamine in water
Authors: Ali Sameh Saad , Grampp Günter , Landgraf Stephan , Sacher Michael
Published: March 2007

External magnetic field effects on the recombination fluorescence (MARY effect) in the photoionization
reaction of N, N, N′, N′‐Tetramethyl‐p‐phenylenediamine (TMPPD) in water and DMSO/water mixture
are studied. Relatively large magnetic field effects (MFE), ∼ 2–4%, on the fluorescence yield are observed in
the extremely polar water solvent under magnetic fields as small as 3 mT. Such MFE is hardly expected in
water due to instability and very fast escape of the solvated electron from the solvent cage. Enhancement
in the signal‐to‐noise ratio and superior time resolution characterizing the technique of field modulation
allowed the detection of a very short lived radical ion pair (about 1 ns). The observed MARY spectra illustrate
that the singlet radical ion pair is more reactive than the triplet one.
Synthetic and natural organic photochromic systems for optic application
Authors: Barachevsky V. A.
Published: March 2007

Own results of the study and application of a number of organic synthetic photochromic systems
in the optical devices are presented. These results are compared with the data obtained for natural
photochromic bacteriorhodopsines. It was shown that synthetic photochromic systems are characterized by
more wide functional possibilities as compared with the natural systems based on bacteriorhodopsine for
application in the optical devices. Advances in application of synthetic and natural photochromic systems
for light modulation and recording optical information as well as nonlinear transformation of laser irradiation
are discussed.
Synthesis, absorption spectra and semiempiric calculations on the photochromism of arylmercuric dithizonate complexes
Authors: Schönherr T. , Schmid V. , Linder R. , Fouda M. F. R. , Amin R. S. , Mostafa S. A.
Published: March 2007

A series of arylmercuric dithizonate complexes have been synthesized and characterized. Optical
spectra of dissolved and pure compounds show transition energies around 480 nm which have been
rationalized by semiempiric PM3 calculations. All complexes show a pronounced photochromism. The calculations
also account for the observed blue absorption of the metastable species when an underlying geometric
arrangement according to the proposal of Meriwether′s is assumed.
A coupling technique for stochastic comparison of functions of Markov Processes
Authors: Doisy M.
Published: March 2007

The aim of this work is to obtain explicit conditions (i.e., conditions on the transition
rates) for the stochastic comparison of Markov Processes. A general coupling technique is used
to obtain necessary and sufficient conditions for the construction of a coupling Markov Process
which stays in a fixed set K for all times and with given marginal processes. The strong stochastic
comparison—or, more generally, the stochastic comparison through states functions—appears as
a particular case. An example in the Reliability Theory is developed and proves the efficiency
of the method. Systems with multiple component types and redundant units are stochastically
compared directly or through particular functions.
Robust estimation in Capital Asset Pricing Model
Authors: Wong Wing-Keung , Bian Guorui
Published: March 2007

Bian and Dickey (1996) developed a robust Bayesian estimator for the
vector of regression coefficients using a Cauchy-type g-prior. This estimator is an adaptive weighted average of the least squares
estimator and the prior location, and is of great robustness with
respect to at-tailed sample distribution. In this paper, we
introduce the robust Bayesian estimator to the estimation of the
Capital Asset Pricing Model (CAPM) in which the distribution of the
error component is well-known to be flat-tailed. To support our
proposal, we apply both the robust Bayesian estimator and the least
squares estimator in the simulation of the CAPM and in the analysis
of the CAPM for US annual and monthly stock returns. Our simulation
results show that the Bayesian estimator is robust and superior to
the least squares estimator when the CAPM is contaminated by large
normal and/or non-normal disturbances, especially by Cauchy
disturbances. In our empirical study, we find that the robust
Bayesian estimate is uniformly more efficient than the least squares
estimate in terms of the relative efficiency of one-step ahead
forecast mean square error, especially for small samples.
The capacitated newsboy problem with revenue sharing
Authors: Pasternack Barry A.
Published: March 2007

In this paper we consider a single inventory (newsboy) problem in which the vendor has a limited amount of funds to purchase items to sell. We assume that the manufacturer will either sell the items to the vendor outright or offer the items to the vendor on a revenue sharing (consignment) basis. In the latter case, that amount of money the vendor pays per unit is less than if the items are purchased from the vendor, but the vendor must share some of the revenue with the manufacturer. The purpose of our analysis is to investigate under what circumstances, it would pay for the vendor to only purchase the items from the manufacturer, only take the items on consignment from the manufacturer, or both purchase and take consignment shipments form the manufacturer.
Weak formulation of free-surface wave equations
Authors: Sneyd A. D.
Published: March 2007

An alternative method for deriving water wave dispersion relations and evolution equations is to use a weak formulation. The free-surface displacement η is written as an eigenfunction expansion, η=∑n=1∞αn(t)En where the αn(t) are time-dependent coefficients. For a tank with vertical sides the En are eigenfunctions of the eigenvalue problem, ∇2+λ2E=0,  ∇E⋅n^=0 on the tank side walls. Evolution equations for the αn(t) can be obtained by taking inner products of the linearised equation of motion, ρ∂v∂t=−1ρ∇P+F with the normal irrotational wave modes. For unforced waves each evolution equation is a simple harmonic oscillator, but the method is most useful when the body force F is something more exotic than gravity. It can always be represented by a forcing term in the SHM evolution equation, and it is not necessary to assume F irrotational. Several applications are considered: the Faraday experiment, generation of surface waves by an unsteady magnetic field, and the metal-pad instability in aluminium reduction cells.
Microwave assisted ignition to achieve combustion synthesis
Authors: Balakrishnan E. , Nelson M. I. , Chen X. D.
Published: March 2007

The use of microwave heating to initiate combustion synthesis has been increasingly investigated in recent years because of its advantages over traditional methods. A simple mathematical model is used to model these experiments. The microwave power absorption term is modelled as the product of an Arrhenius reaction term with a function that decays exponentially with distance. The former represents the temperature-dependent absorption of the microwaves whereas the latter describes the penetration of the material by the microwaves. Combustion kinetics are modelled as a first-order Arrhenius reaction.
Power of the Neyman smooth tests for the uniform distribution
Authors: Rayner Glen D. , Rayner John C. W.
Published: March 2007

This paper compares and investigates the generalised Neyman smooth test, its components, and the classical chi-squared test with a variety of equiprobable classes. Each test is evaluated in terms of its power to reject a wavelike alternative to the uniform distribution, chosen to quantify the complexity of the alternative. Results indicate that if broadly focused tests (rather than strongly directional or weakly omnibus) are sought, then smooth tests of order about four, or the chi-squared test with between five and ten classes, will perform well.
Nonparametric statistical methods and the pricing of derivative securities
Authors: Kiesel Rüdiger
Published: March 2007

In this review paper we summarise several nonparametric methods recently
applied to the pricing of financial options. After a short introduction to martingale-based
option pricing theory, we focus on two possible fields of application for nonparametric
methods: the estimation of risk-neutral probabilities and the estimation of the dynamics
of the underlying instruments in order to construct an internally consistent model.
The value of econometrics to economists in business and government: a study of the state of the discipline
Authors: Sowey Eric R.
Published: March 2007

This paper is the first ever in-depth study of the econometric practice of
quantitative economists outside academia. It goes further, to examine empirically the
often-heard proposition that academic and nonacademic economists nowadays seem to
analyse the same applied quantitative problems in markedly separate ways. Nine indicators
of separation between the approaches of ‘town’ and ‘gown’ economists are developed.
The study rests on detailed interviews with 50 nonacademic economists drawn
widely from a single area of professional activity: the Australian housing sector. These
economists' use of econometric methods, and their views on the value of these methods,
are documented and compared with the academic approach to applied econometric work,
as reported in the scholarly literature. The evidence on the nine indicators supports the
existence of a state of separation. The paper points to some undesirable consequences of
separation and concludes with practical ideas on what should be done about it. There
are lessons in the findings of this study for the future of other quantitative disciplines
that are widely practised in government, business and industry.
Analytical bootstrap methods for censored data
Authors: Hutson Alan D.
Published: March 2007

Analytic bootstrap estimators for the moments of survival quantities are
derived. By using these expressions recommendations can be made as to the appropriateness
of bootstrap estimation under censored data conditions.
A new heuristic for the quadratic assignment problem
Authors: Drezner Zvi
Published: March 2007

We propose a new heuristic for the solution of the quadratic assignment
problem. The heuristic combines ideas from tabu search and genetic algorithms. Run
times are very short compared with other heuristic procedures. The heuristic performed
very well on a set of test problems.
Goodness-of-fit tests based on sample space partitions: a unifying overview
Authors: Thas O. , Ottoy J. P.
Published: March 2007

Recently the authors have proposed tests for the one-sample and the κ-sample problem, and a test for independence. All three tests are based on sample space
partitions, but they were originally developed in different papers. Here we give an
overview of the construction of these tests, stressing the common underlying concept of “sample space partitions.”
Estimating a resource selection function with line transect sampling
Authors: Manly Bryan F. J.
Published: March 2007

A resource selection probability function is a function that gives the prob-
ability that a resource unit (e.g., a plot of land) that is described by a set of habitat
variables X1 to Xp will be used by an animal or group of animals in a certain period of
time. The estimation of a resource selection function is usually based on the comparison
of a sample of resource units used by an animal with a sample of the resource units
that were available for use, with both samples being assumed to be effectively randomly
selected from the relevant populations. In this paper the possibility of using a modified
sampling scheme is examined, with the used units obtained by line transect sampling. A
logistic regression type of model is proposed, with estimation by conditional maximum
likelihood. A simulation study indicates that the proposed method should be useful in
practice.
The effects of I(1) series on cointegration inference
Authors: Lin Yan-Xia , Mccrae Michael
Published: March 2007

Under traditional cointegration tests, some eligible I(1) time series systems Xt, that are not cointegrated over a given time period, say (0,T1], sometimes test as
cointegrated over sub-periods. That is, the system appears to have a stationary linear
structure ζ′Xt for certain vector ζ in the period 0<t≤T1. Understanding the dynamics
between cointegration test power and restricted sample size that causes this inversion
of results is a crucial issue when forecasting over extended future time periods. In this
paper, we consider non-cointegrated systems that are closely related to collinear systems.
We apply a residual based procedure to such systems and establish a criterion for making
the decision whether or not Xt can be continuously accepted as I(0) for t>T1 when Xt was accepted as I(0) fort≤T1.
The theoretical basis of heat flux sensor pen
Authors: Chen Xiao Dong , Nguang Sing Kiong
Published: March 2007

Measuring heat flux out or into a process surface is of significant practical interest. Miniaturization of the sensor and the capability of dynamic sensing are highly desirable. In this paper, the theoretical basis of a heat flux sensor ‘pen’ idea has been established, which allows for real-time measurements. Here the thin temperature measuring wires (thermocouple) are used as the heat flux sensing and heat carrier device. Such a device is shown to be feasible with the available solutions obtained using a semi-empirical approach employing Laplace transformation method combined with an intermediate curve-fitting procedure in the case of finite sensor length and exact solution already available in literature in the semi-infinite domain case.
Minimal waiting times in static traffic control
Authors: Moeschlin O. , Poppinga C.
Published: March 2007

The paper discusses the question of the optimal control of an unsymmetric bottleneck system with Poisson arrival processes having the minimization of the mean individual waiting time as objective. The setup allows the straightforward generalization to more complicated forms of traffic organization. The notion of the mean individual waiting time is based on a theorem of the Little type, which is derived by a strong law of large numbers. The proof makes use of McNeil's formula, which connects the expected total waiting time with the expected queue length.
An international project for the development of data handling skills of teachers and pupils
Authors: Davies Neville , Connor Doreen , Spencer Nancy
Published: March 2007

In this paper we provide an overview of the international CensusAtSchool project, designed, written and implemented first in the UK from October 2000 - April 2001 for pupils aged 7 -16 in primary and secondary schools. It has been adapted for similar aged school children in South Africa and Australia and was implemented in those countries in July and October 2001, respectively. We present our motivation, aims and objectives for carrying out such a project and show some results of analysis from the returns we have received from all three countries. Key outputs from the project include: worksheets that are suitable for enhancing data handling skills of pupils; a training course that wraps information and communications technology with data handling skills that is suitable to enhance the professional development of teachers; a raised awareness amongst pupils and teachers of the need to properly collect, present and analyze primary data; a contribution to improving the statistical numeracy and thinking skills of both teachers and pupils.
Electronic resources: the Ohio state university EESEE project
Authors: Graham Petra L. , Notz William I. , Pearl Dennis K. , Stasny Elizabeth A.
Published: March 2007

Electronic resources aid in the teaching and learning of statistics by providing data that may be used interactively by teachers and students. By interacting with the data students are encouraged to discover knowledge and thereby gain a deeper understanding of statistical concepts. The Electronic Encyclopedia of Statistical Examples and Exercises (EESEE) is an electronic resource that includes over 80 ‘real-world’ examples about the uses and abuses of statistics. These examples are drawn from published and printed media and the diverse range of subject-matter areas make it suitable for use in any statistics course.
Making statistics significant in a short course for graduates with widely-varying non-statistical backgrounds
Authors: Macgillivray H. L.
Published: March 2007

Abstract. With reference to a short compulsory module for MBA students, this paper discusses how, despite a range of pressures and an extraordinary range of student backgrounds, fears and motivations, it is possible to quickly facilitate understanding and confidence in handling data and basic statistics for graduates in business and associated workplaces. Links and contrasts with a variety of undergraduate teaching scenarios help to enrich teaching and learning strategies, and the strategies and materials developed through interaction with the range of MBA students are transferable to other postgraduate coursework situations. In particular, the need for understanding and confidence in handling data and its presentation, in considering categorical and simple continuous data, and in understanding correlation and association, are common across many different workplaces and applications.
Some results of ruin probability for the classical risk process
Authors: Yuanjiang He , Xucheng Li , Zhang John
Published: March 2007

The computation of ruin probability is an important problem in the collective
risk theory. It has applications in the fields of insurance, actuarial science, and
economics. Many mathematical models have been introduced to simulate business activities
and ruin probability is studied based on these models. Two of these models
are the classical risk model and the Cox model. In the classical model, the counting
process is a Poisson process and in the Cox model, the counting process is a Cox
process. Thorin (1973) studied the ruin probability based on the classical model with
the assumption that random sequence followed the Γ distribution with density function f(x)=x1β−1β1βΓ(1/β)e−xβ, x>0, where β>1. This paper studies the ruin probability of the classical model where the random sequence follows the Γ distribution with density function f(x)=αnΓ(n)xn−1e−αx, x>0, where α>0 and n≥2 is a positive integer. An intermediate general result is given and a complete solution is provided for n=2. Simulation studies for the case of n=2 is also provided.