bluuebunny/crossref_metadata_2025 huggingface dataset:
Ground deformation at Campi Flegrei, Italy: implications for hazard assessment
Authors: Bellucci Francesca , Woo Judith , Kilburn Christopher R. J. , Rolandi Giuseppe
Published: April 2008

Campi Flegrei caldera, west of Naples in southern Italy, has an exceptional documented record of ground deformation from Roman times onwards. Systematic recording began in the nineteenth century. For earlier dates, information has been obtained from archaeological studies and from contemporary descriptions of the locations of buildings, usually Roman, with respect to sea-level. Especially important have been accounts related to the Serapis, a Roman market-place built in the second century
bc
and now incorporated within the modern town of Pozzuoli. The long-term patterns of ground deformation have conventionally been investigated on the premise that Campi Flegrei naturally tends to a state of static equilibrium. This study argues that, instead, the area naturally tends to a steady rate of subsidence, at about 17 mm a
−1
. After this background rate has been removed, the data indicate that a permanent uplift of some 33 m has occurred from Roman times (up until the present day: 2005 at the time of writing), attributable to the intrusion of 1.85 km
3
of magma, of which only 1% has been erupted. Uplift has occurred in three episodes, the third of which is still in progress. The behaviour can be interpreted in terms of the intermittent ascent of magma between a reservoir of
c.
10
2
–10
3
km
3
at depths of 8–15 km or greater, to a much smaller, shallower system at depths of about 3–4 km. Should the current pattern of deformation follow previous trends, uplift is expected to continue for another 80–90 years, during which time Campi Flegrei will be characterized by an elevated possibility of eruption.
Rapid karstic bypass flow in the unsaturated zone of the Yorkshire chalk aquifer and implications for contaminant transport
Authors: Allshorn S. J. L. , Bottrell S. H. , West L. J. , Odling N. E.
Published: April 2008

Tracer tests have been performed on the unsaturated zone of the East Yorkshire chalk aquifer, UK. Rapid tracer travel times through significant thicknesses of unsaturated chalk (15–38 m) indicate that bypass flow must occur through fractures. Transport processes in the unsaturated zone of the chalk aquifer thus have similarities to those in the vadose zone of more typically karstic limestone aquifers. Modelling of tracer breakthrough curves indicates that bypass flow is sufficiently rapid to significantly inhibit diffusional loss of tracer into the porous matrix of the chalk. The presence of rapid karstic bypass flow in the unsaturated zone of the chalk will limit the potential for attenuation of groundwater contaminants in this zone.
Molecular correlates for maximal oxygen uptake and type 1 fibers
Authors: Parikh Hemang , Nilsson Emma , Ling Charlotte , Poulsen Pernille , Almgren Peter , Nittby Henrietta , Eriksson Karl-Fredrik , Vaag Allan , Groop Leif C.
Published: April 2008

Maximal oxygen uptake (V̇o2max) and the amount of type 1 fibers are interrelated, but the underlying unifying molecular mechanisms are poorly understood. To explore these mechanisms, we related gene expression profiles in skeletal muscle biopsies of 43 age-matched men from published datasets with V̇o2max and the amount of type 1 fibers and replicated some of the findings in muscle biopsies from 154 young and elderly individuals using real-time PCR. We identified 66 probe sets (genes or expressed sequence tags) positively and 83 probe sets inversely correlated with V̇o2max and 171 probe sets positively and 217 probe sets inversely correlated with percentage of type 1 fibers in human skeletal muscle. Genes involved in oxidative phosphorylation (OXPHOS) showed high expression in individuals with high V̇o2max, whereas the opposite was not the case in individuals with low V̇o2max. Instead, genes such as AHNAK and BCL6 were associated with low V̇o2max. Also, expression of the OXPHOS genes NDUFB5 and ATP5C1 increased with exercise training and decreased with aging. In contrast, expression of AHNAK in skeletal muscle decreased with exercise training and increased with aging. Eleven genes ( NDUFB4, COX5A, UQCRB, ATP5C1, ATP5G3, ETHE1, FABP3, ISCA1, MYST4, C9orf3, and PKIA) were positively correlated with both V̇o2max and the percentage of type 1 fibers. V̇o2max closely reflects expression of OXPHOS genes, particularly that of NDUFB5 and ATP5C1, in skeletal muscle, suggesting good muscle fitness. In contrast, a high expression of AHNAK was associated with a low V̇o2max and poor muscle fitness.
Exposure to inhaled particulate matter impairs cardiac function in senescent mice
Authors: Tankersley Clarke G. , Champion Hunter C. , Takimoto Eiki , Gabrielson Kathleen , Bedja Djahida , Misra Vikas , El-Haddad Hazim , Rabold Richard , Mitzner Wayne
Published: April 2008

Daily exposure to particulate matter (PM) is known to adversely affect cardiac function and is also known to be exaggerated with senescence. This study tests the hypothesis that cardiac function is uniquely altered by PM exposure in senescent mice. A mechanism for PM-induced cardiac effects is also postulated by examining the activity of nitric oxide synthase (NOS) and the generation of reactive oxygen species (ROS) in heart tissue. Echocardiography is performed in awake 18- and 28-mo-old mice at baseline and immediately following 3-h exposures to either filtered air or carbon black (CB; ∼400 μg/m3) on 4 days. At 28 mo, left ventricular diameter at end-systole and end-diastole is significantly ( P < 0.05) elevated, and fractional shortening is significantly reduced (49 ± 3% vs. 56 ± 3%) with CB exposure. In vivo hemodynamic measurements at 28 mo also demonstrate significant ( P < 0.05) reductions in ejection fraction and increases in right ventricular and pulmonary vascular pressures following CB exposure. Functional changes at 28 mo are associated with increased ROS production as suggested by enhanced luminol activity. This elevated ROS production with aging and CB exposure is attributable to NOS uncoupling. Measurements of natriuretic peptide (atrial and brain) transcription and matrix metalloproteinase (MMP2 and MMP9) activity in heart tissue are significantly ( P < 0.05) amplified with senescence and exposure to CB, pointing to increased cardiac stress and remodeling. These results demonstrate that acute PM exposure reduces cardiac contractility in senescent mice, and this decline in function is associated with increased ROS production linked to NOS uncoupling.
Blockade of NGF and trk receptors inhibits increased peripheral mechanical sensitivity accompanying cystitis in rats
Authors: Guerios Simone D. , Wang Zun-Yi , Boldon Kyle , Bushman Wade , Bjorling Dale E.
Published: April 2008

Visceral inflammation, including that arising from bladder inflammation, reduces the threshold to sensation of innocuous or noxious stimuli applied to peripheral structures (referred hyperalgesia). Cystitis may induce transient or persistent plastic changes mediated by neurotrophins, particularly nerve growth factor (NGF), which contribute to increased nociceptive input. In this study, acute or subacute cystitis was induced in female rats by one or three (at 72-h intervals) 400-μl intravesical instillations of 1 mM acrolein. Sensitivity of the hindpaws to mechanical and thermal stimuli was determined before and 4, 24, 48, 72, and 96 h after treatment. Other groups of rats were treated with intravesical or intrathecal k252a [a nonspecific antagonist of tyrosine kinase (trk) receptors, including trkA, the high-affinity receptor for NGF] before the first or third acrolein instillation. Some rats were intraperitoneally injected with specific NGF-neutralizing antiserum or normal serum before acrolein instillation. Acute and subacute cystitis induced mechanical, but not thermal, referred hyperalgesia that was attenuated by intravesical pretreatment with k252a. Systemic treatment with NGF-neutralizing antiserum before instillation of acrolein suppressed subsequent mechanical referred hyperalgesia. Expression of NGF was increased within the bladder by acute or subacute cystitis and in L6/S1 dorsal root ganglia by subacute cystitis. These results suggest that the bladder-derived NGF acting via trk receptors at least partially mediates peripheral sensitization to mechanical stimuli associated with acute and subacute acrolein-induced cystitis.
Alexander's Law Revisited
Authors: Jeffcoat Benjamin , Shelukhin Alexander , Fong Alex , Mustain William , Zhou Wu
Published: April 2008

Alexander's Law states that the slow-phase velocity of the nystagmus caused by unilateral vestibular lesion increases with gaze in the beat direction. Two studies have shown that this gaze effect is generalized to the nystagmus caused by unilateral cold water irrigation. This indicates that the gaze effect is not the result of central changes associated with a peripheral lesion but rather because of unilateral vestibular peripheral inhibition. In this study, we show that there is a similar gaze effect on the nystagmus produced by unilateral warm water ear irrigation. Furthermore, we examined the two hypotheses of Alexander's Law proposed in the two studies. One hypothesis is based on the gaze-dependent modulation of the vestibulo-ocular reflex (VOR) response to unbalanced canal input. The other hypothesis, however, is based on the leaky neural integrator caused by unilateral vestibular peripheral inhibition. These two hypotheses predict the same gaze effect on the nystagmus produced by cold water irrigation, but opposite gaze effects on the nystagmus produced by warm water irrigation. Our results support the first hypothesis and suggest that the second hypothesis needs to be modified.
Spike Timing-Dependent Long-Term Potentiation in Ventral Tegmental Area Dopamine Cells Requires PKC
Authors: Luu Percy , Malenka Robert C.
Published: April 2008

Long-term potentiation (LTP) of excitatory synapses on ventral tegmental area (VTA) dopamine (DA) cells is thought to play an important role in mediating some of the behavioral effects of drugs of abuse yet little is known about its underlying mechanisms. We find that spike timing-dependent LTP (STD LTP) in VTA DA cells is absent in slices prepared from mice previously administered cocaine, suggesting that cocaine-induced LTP and STD LTP share underlying mechanisms. This form of STD LTP is dependent on NMDA receptor (NMDAR) activation and a rise in postsynaptic calcium but surprisingly was not affected by an inhibitor of calcium/calmodulin-dependent protein kinase II (CaMKII). It was blocked by antagonists of conventional isoforms of PKC, whereas activation of protein kinase C (PKC) using a phorbol ester enhanced synaptic strength. These results suggest that NMDAR-mediated activation of PKC, but not CaMKII, is a critical trigger for LTP in VTA DA cells.
MI Neuronal Responses to Peripheral Whisker Stimulation: Relationship to Neuronal Activity in SI Barrels and Septa
Authors: Chakrabarti Shubhodeep , Zhang Mengliang , Alloway Kevin D.
Published: April 2008

The whisker region in the rodent primary motor (MI) cortex receives dense projections from neurons aligned with the layer IV septa in the whisker region of the primary somatosensory (SI) cortex. To compare whisker-induced responses in MI with respect to the SI responses in the septa and adjoining barrel regions, we used several experimental approaches in anesthetized rats. Reversible inactivation of SI and the surrounding cortex suppressed the magnitude of whisker-induced responses in the MI whisker region by 80%. Subsequent laminar analysis of MI responses to electrical or mechanical stimulation of the whisker pad revealed that the most responsive MI neurons were located ≥1.0 mm below the pia. When layer IV neurons in SI were recorded simultaneously with deep MI neurons during low-frequency (2-Hz) deflections of the whiskers, the neurons in the SI barrels responded 2–6 ms earlier than those in MI. Barrel neurons displayed similar response latencies at all stimulus frequencies, but the response latencies in MI and the SI septa increased significantly when the whiskers were deflected at frequencies of 8 Hz. Finally, cross-correlation analysis of neuronal activity in SI and MI revealed greater amounts of time-locked coordination among septa–MI neuron pairs than among barrel–MI neuron pairs. These results suggest that the somatosensory corticocortical inputs to MI cortex convey information processed by the SI septal circuits.
Thick Film Temperature Sensors Using Standard Pastes
Authors: Janoska I. , Haskard M. R.
Published: April 2008

Standard thick film resistor pastes exhibit changes in their electrical characteristics when printed on top of dielectric layers. Of particular interest is the inherent change in their temperature coefficient of resistance.
Simple temperature sensors were formed by deliberately printing thick film resistor pastes on top of larger area
dielectric layers. Temperature tests carried out on these devices have shown that by selecting the correct paste
combination and resistor aspect ratio stable, repeatable, temperature sensors with good linearity can be
manufactured. A comparison is made of these sensors to other commercially available products currently used
in the thick film industry.
Effect of V2O5 Dopant on the Electrical Conductivity of RuO2 Thick Film Resistors
Authors: Setty M. S. , Shinde R. F.
Published: April 2008

Thick film glaze resistors have been prepared using V2O5 doped RuO2 conducting phase. Different amounts of V2O5 were incorporated into RuO2lattice by solid state reaction. Sheet resistivity decreased from 235 to 10 kΩ/Sq, with the increase in the dopant concentration from 2 to 6% wt. The conductivity, ‘σ’, was found to fit
in the equation σ= KS(l‐S), where S is the probability that a given cationic site will contain an extra charge
carrier and K = 10-3 mho‐sq.
Low Frequency Noise in Tantalum Capacitors
Authors: Smith D. T.
Published: April 2008

Noise has been measured in a number of biased solid tantalum capacitors at frequencies down to 0.01 Hz. The
noise current was found to have a 1/f power spectrum, and the amplitude varied with the bias voltage with a law
in the range 1st to 4th power. There was a large difference in amplitudes between different capacitors of the
same type.
Feasibility of Using Oscillatory Catalytic Oxidation Phenomenon for Selective Carbon Monoxide Sensing
Authors: Torvela Heikki
Published: April 2008

Tin dioxide based sensors with different additives were constructed and tested in air environment containing carbon
monoxide. Conductance oscillations were observed in samples containing palladium but not in those without.
Oscillations occurred at temperatures ranging from 150℃ to 320℃. Within this temperature region the range of CO
concentrations at which oscillations appeared became higher as the test temperature increased. The lowest CO
concentration at which oscillations were observed was 200 ppm and the highest 10000 ppm.

By comparing sensor responses obtained in synthetic and ambient air it was concluded that water vapour has a
major influence on oscillations and increases the frequency. The ranges of CO concentrations in which oscillations
occurred at different temperatures, however, remained roughly the same in both environments. It was also noticed that
processing conditions had an influence on the oscillatory response characteristics of the sensors.
Thermal and Electrical Analysis of Solid Aluminium Capacitors
Authors: Dekker E. H.L.J. , Lasance C. J.M.
Published: April 2008

The thermal properties of electronic components partly determine the reliability of electronic equipment.
For electrolytic capacitors, they also set the limits for the ripple current and voltage values.

This article first discusses the voltage limits under various conditions of temperature, frequency and
polarity. Then the connection of ripple current to these parameters and to the capacitor′s resistance is
treated.

An extensive analysis is made of the influence of heat conduction in the capacitor and the printed‐circuit
board, for metal‐cased as well as for epoxy‐coated pearl types. The study pays particular attention
to solid aluminium capacitors containing a manganese dioxide semiconductor. They have some
extraordinary properties: a temperature range of at least – 80 to + 175℃, and an appreciable reverse
voltage potential.These can be fully employed to improve the ripple‐current specification.
The Growth and Assessment of GaAs Epitaxial Layers Obtained FromGa‐As‐Bi Solutions
Authors: Kozlowski J. , Panek M. , Ratuszek M. , Tlaczala M.
Published: April 2008

X‐Ray investigations of GaAs epitaxial layers obtained from Ga‐As‐Bi solutions with different amounts of
bismuth are presented. An equilibrium cooling and two phase technique for the deposition of the GaAs
epitaxial layers on semi‐insulating GaAs:Cr(100) substrates has been used.

It has been observed that independently of the growing solution composition, the epitaxial layers were
single crystal of (100) crystallographic orientation. Bismuth and chromium were not identified as impurities in
the investigated layers although this may be due to the low sensitivity (0.1 at . %) of the x‐ray microprobe used.
Stability and Performance Characterization of Thick FilmMicroresistors
Authors: Ravi Shobha C.
Published: April 2008

In recent years, interest in the performance of small dimension resistors has increased primarily due to the need
to reduce parasitic resistance in high frequency applications. This paper presents results on the characterization
of thick film microresistors, i.e. resistors of 80 × 80 mil to 10 × 10 mil dimension.

The thickness, sheet resistance and temperature coefficient of resistance were dependent on the resistor
length, whereas, thermal ageing drift and the thermal cycling drift values did not exhibit any such dependence.

With reasonable precautions and optimization of the manufacturing conditions highly stable and good
quality microresistors can be fabricated.
A Simple Distributed RGC Model of MOSFET for Pre‐Pinch Off Region
Authors: Kumar Umesh , Mirchandani Arun
Published: April 2008

The differential equation describing the small signal behavior of a MOSFET channel is
derived. Based on the analogy of the channel to distributed transmission lines, which
has been very well established in literature, an entirely new RGC line model of
MOSFET is presented. The element values of the line are determined by equivalence
to a general distributed transmission line and subsequently the model is lumped into a
single section in two possible Π and T representations. The postulated model
considerably simplifies the study of the properties and behavior of MOSFET structures
and can be suitably utilized in analysis and Computer Aided Design.
Performance Comparison of Thin and Thick Film Microstrip Rejection Filters
Authors: Mandhare M. M. , Gangal S. A. , Setty M. S. , Karekar R. N.
Published: April 2008

A performance comparison of microstripline circuits using thin and thick film
techniques has been studied, in which a Microstrip rejection filter, in the X‐band of
microwaves, is used as test circuit. A thick film technique is capable of giving good
adhesive films with comparable d.c. sheet resistivity, but other parameters such as
open area (porosity), particle size, and edge definition are inferior to thin‐film
microstrip filters. Despite this drawback, the average value of transmission,
transmission loss, reflection coefficient, resonant rejection frequency, and quality
factor for thick‐film filters indicate that screen printed Ag films are intermediate
between thin‐film1,2,9 and etched‐thick‐film9 microstrip filters in performance, making
it a feasible method for microstrip circuits.
AG‐Based Thick‐Film Front Metallization of Silicon Solar Cells
Authors: Prudenziati M. , Moro L. , Morten B. , Sirotti F. , Sardi L.
Published: April 2008

The evolution of microstructure and electrical properties of silver‐based thick‐film
metallizations of silicon solar cells prepared by infrared firing processes has been
investigated. The performance of the cells are shown to be dependent on several
dynamical and diffusive phenomena. In particular, the sintering of silver grains, silver
diffusion into the glass, and the flow of glass at the metal/silicon interface strongly
affect important characteristics of the cells such as sheet and contact resistivities and
the adhesion of fingers and bus bars. The existance of an optimum value of the peak
firing temperature is observed and explained in terms of competitive phenomena
occurring at the metal/silicon interface. Moreover it is shown that IR firing treatments
require a careful consideration of the sequence of printing and firing steps. The
features of heat treatments performed in conveyor belt furnances using Joule and
infrared sources are compared.
Thermoresistive Thin Film Flow Sensor
Authors: Berlicki T. M. , Murawski E. , Osadnik S. J. , Prociòw E. L.
Published: April 2008

Some technological aspects and basic parameters of nickel thin film gas flow sensors
are presented. Thermal conditions of sensors are described by the mechanisms of heat
transfer. Typical characteristics measured during the sensor operation are given.
Protection of Photoanodes Against Photo‐Corrosion by Surface Deposition of Oxide Films: Criteria for Choosing the Protective Coating
Authors: Campet G. , Manaud J. P. , Puprichitkun C. , Sun Z. W. , Salvador P.
Published: April 2008

Two strategies to solve the problem of instability of photoanodes against photocorrosion
have been explored. The photocorrosion of photoanodes generally occurs when
they enter the fabrication of efficient photoelectrochemical cells (i.e. showing high
values of the open circuit voltage and photocurrent density).

One of these strategies consists of protecting the photoanode against photocorrosion
by a non‐conducting oxide film deposited on its surface. The oxide must have a
cationic valence band, or valence energy states, falling either above, or at the same
level as, the top of the valence band of the anode. The significant photocurrent
observed with the n‐GaAs/Sr0.98Na0.01Ce0.01TiO3 hybridelectrode structure confirms the validity of the model.

The second possibility deals with the protection of the photoanode by a conducting
oxide film in which the carrier transport occurs, close to the Fermi level, via either a
partially filled band or a sufficiently high density of localized states. We have illustrated
this method of protection by depositing n‐SrTiO3 on n‐GaAs. The n‐SrTiO3 films have
the Fermi level pinned within the forbidden band by Ti:3d(t2g) energy states. The
corresponding electrochemical cells exhibit photoconversion efficiency as high as 18%
for an illumination of 5 mW/cm2.
Screen‐Printed Superconducting Y‐Ba‐Cu‐O Thick Films on Various Substrates
Authors: Kokkomäki T. , Uusimäki A. , Rautioaho R. , Levoska J. , Murtoniemi T. , Leppävuori S.
Published: April 2008

Superconducting thick films of the Y‐Ba‐Cu‐O system prepared by screen‐printing and
sintering on different substrates were investigated to study the effect of the substrate
material on the superconducting properties of the films. These properties were determined
by carrying out structural studies using SEM, EPMA and XRD and by
determining the electrical resistivity. The effect of diffusion barrier layers between the
film and the substrate on the superconducting properties of the film was also studied.
The onset temperature of superconductivity in YBa2Cu3O7−δ (123) superconducting
thick film was around 92 K on almost all the substrates. The substrate material had an
influence on the temperature at which zero resistance (i.e. Tc) was attained. This
varied from 85 K on yttrium stabilized zirconium oxide (YSZ) and nickel substrates
down to below 70 K on other substrates. Nickel offered promise as being a good
diffusion barrier between the substrate and the 123 superconducting thick film because
the reactions between the film and nickel occurred slowly and did not impair the
superconducting properties of the film. In the case of alumina substrates, there was a
rapid reaction which took place at high annealing temperatures. A BaAl2O4 phase was
found between the film and the alumina substrate which promoted adhesion but
resulted in poor superconducting properties of the film.
Size Effects on Thermal Properties ofThin Metal Films With Rough Surfaces
Authors: Tellier C. R.
Published: April 2008

By calculating the effects of electronic scattering at rough surfaces by means of a combined Soffer‐Cottey
model, general theoretical expressions for the size effects in thermal properties of thin metal films are proposed.
Simple analytical expressions for the thermoelectric power, Sf, and the thermal conductivity, ℒf, are given
under the assumption that the energy dependence of the electronic relaxation time in bulk material may be
written in the form τo ~ Wm
. The size effects in the thermoelectric power are found to depend on the value
of m. However, a decrease in the overall size effects is observed in all transport parameters with respect to
the predictions of classical theories based on the Fuchs‐Sondheimer or the Cottey models. A comparison with
data on the thermoelectric power of thin copper, silver and tin films from previous experiments by various
workers shows that a combined Soffer‐Cottey model is convenient to analyze size effects in thermoelectric
properties. The values of the r.m.s, surface roughness obtained from data are physically consistent.
The Transmission of Bulk Power Over Long Distances
Authors: Hamed M.
Published: April 2008

Circular, plate, radial and coaxial arrangements for phases of double circuit transmission lines are proposed.
Power transmission over long distances depends on the mutual effect between each two respective phases. A
theoretical analysis for voltage, power and current along such lines is presented. The general constants for each
configuration are evaluated, as well as the maximum power limit for long distance double circuit transmission
lines. Different voltage levels of 500 and 1000 kV are considered for a length of 1000 km. An external
impedance is suggested to be connected at various points of coaxial arrangement with separate phases. The
capacitive effect for such an external impedance is studied.
Thick Film Circuit Layout and Extraction of Parameters Using The Magic Layout Editor
Authors: Avaritsiotis J. N.
Published: April 2008

A Technology file for the Magic layout editor has been developed in order to enable thick film circuit
designers to evolve fast solutions for layout with design rule checking, and plotting of the masks of
multilayer hybrid circuits. The hybrid design system developed provides for device placement, and
automatic routing techniques, in thick film circuits. Device placement is done by recalling from the
library the pad pattern that corresponds to the device to be positioned. Automatic routing is implemented
not only in multilayered circuits but also in single‐layer technology (i.e. two possible types of metal
routed on the bare substrate) where dielectric tiles are automatically created at metal crossings, when
an electric contact is not desired.
Layout and Thermal Analysis of PowerDevices Using a PC/XC
Authors: Avaritsiotis J. N. , Eleftheriades G.
Published: April 2008

Thermal analysis during the design process is an essential step towards the achievement of high reliability
in modern high density hybrid and integrated circuits. Thermal analysis is also essential for modern,
high density PCBs. Traditionally, a solution of the thermal problem is obtained by either the method
of finite differences or the method of finite elements. Both methods, however, require a fine 3‐D
partition of the substrate, leading to large systems of linear equations the solution of which demands
substantial computing power provided by number crunching machines and/or powerful computer work‐stations.

The widespread use of personal computers, however, dictates the development of new approaches
to the thermal problems so that a design engineer can solve them in reasonable time with a PC. A new
treatment of steady‐state thermal analysis combined with a layout editor is proposed in this paper,
which makes use of the analytical solution for the temperature distribution in a single‐layer substrate
with heat sources on the surface, and having an isothermal bottom surface. In this way the mathematical
complexity of the problem is dramatically reduced allowing the thermal analysis of Multi Chip Modules
(M.C.M.s) and complex hybrid circuits with the use of a PC/XT or compatible.
Application of Silver Conducting Glasses to Solid State Batteries and Sensors
Authors: Jun Liu , Portier J. , Tanguy B. , Videau J. J. , Ait Allal M. , Morcos J. , Salardenne J.
Published: April 2008

Fast silver ion conducting glasses as electrochemical devices have been tested. A silver iodine battery
using a silver ionic conducting glass (AgPO3‐Ag2S‐AgI) has been studied. The interaction of some gases
(O2 CI2, H2S) with the electrochemical chains: Pt/Sb2S3‐AgI (glass)/Ag and Pt/AgCl (thin film)/Sb2S3‐
AgI (glass)/Ag has been investigated. Finally, the behavior of thin films of Ag2S3‐Ag2S‐CdS glasses as
sensitive membranes for Cd detection in solution has been tested on MIS structures Au/Si/SiO2/
Membrane/Cd in solution/Reference electrode.
Electrical Modelling of Multilevel On‐Chip Interconnections for High‐Speed Integrated Circuits
Authors: Dimopoulos K. Z. , Avaritsiotis J. N. , White S. J.
Published: April 2008

A method for the electrical parameters analysis and modelling of lossy‐coupled multilayer on‐chip
interconnection lines at high bit rates is presented in detail. It can be used by the VLSI designer to
analyze on‐chip interconnections with linear, as well as nonlinear/time varying terminators and to
simulate the pulse propagation characteristics in high‐speed integrated circuits. First the capacitance,
inductance, conductance and resistance matrices per unit length for the given multiconductor geometry
is computed. A multiple coupled line model consisting of uncoupled lossy transmission lines and linear
dependent current and voltage sources if finally calculated according to the capacitance, inductance,
conductance and resistance matrix values computed.
Reliability Prediction of Thick Film Hybrid Integrated Circuits
Authors: Pranchov Rumen , Athanassova Veneta , Georgiev Ruslan , Pomakov Stefan
Published: April 2008

When using the well known handbooks for reliability predicting (MIL, CNET) some problems occur
in quality assessment of components which are not produced according to the requirements of the US
military or the French standards. The results obtained from tests of Test Pattern Circuits may be used
successfully for reliability estimating during the design period of new thick film Hybrid Integrated
Circuits. Six types of Test Pattern Circuits were designed and tested and a model for estimating thick
film Hybrid Integrated Circuits failure rate is proposed. Failure rate values predicted by using the
method with Test Pattern Circuits, and the results, obtained from the tests of two kinds of Hybrid
Integrated Circuits concerned for a 90% confidence level were compared.
Highly Reversible Electrochemical Insertion of Lithium, Accompanied With a Marked Color Change, Occuring inMicrocrystalline Lithium NickelOxide Films
Authors: Campet G. , Portier J. , Morel B. , Ferry D. , Chabagno J. M. , Benotmane L. , Bourrel M.
Published: April 2008

Thin films of lithium‐nickel oxide, whose texture consists of microcrystallites with an average grain size
of 50 Å, permit highly reversible electrochemical insertion of lithium ions in Li+ conducting electrolytes.
Therefore, the corresponding materials would be of great interest for energy storage applications. In
addition, the lithium insertion/extraction reactions in the nickel‐based layers are accompanied with a
marked color change, making these films of interest for the development of electrochromic displays for
the control of light transmission in windows (“smart windows”).
Pinning in High‐Tc Superconductors
Authors: Brandt Ernst Helmut
Published: April 2008

Magnetic flux can penetrate a type‐II superconductor in the form of flux‐lines or Abrikosov vortices,
each of which carry a quantum of flux and arrange in a more or less regular triangular lattice. Under
the action of an electric current, these flux lines move and dissipate energy unless they are pinned by
material inhomogeneities. In conventional superconductors, depinning occurs when a critical current
density Jc is exceeded. In high‐Tc superconductors (HTSC), thermally activated depinning causes a finite
resistivity t9 even at current densities J ≪ Jc. At sufficiently large temperature T, linear (ohmic) resistivity
is observed down to J → 0. This indicates that the flux lines are in a "liquid state" with no shear stiffness
and with small depinning energy. At lower T, ρ(J) is highly nonlinear, since the pinning energy increases
with decreasing J. In highly anisotropic Bi‐ and Tl‐based HTSC, thermal depinning occurs at rather
low T, since short vortex segments ("pancake vortices" in the CuO layers) can depin individually with
very small activation energy.
Plasma‐Optical Effect in GaAs PIN Photodiodes
Authors: Caffaro M. A. Grado , Caffaro M. Grado
Published: April 2008

This paper is devoted to the analysis of the Plasma‐Optical Effect in GaAs PIN photodiodes operating
at the infrared range. An approximated expression for the variation of the refractive index in the
intrinsic zone of a AsGa PIN photodiode is obtained. This variation is induced by the charge of the
device. The approach developed by us is in a good agreement with experimental works. Moreover, an
application concerning high‐frequency ICs is outlined.
New Results on the Noise Figure of HEMTs
Authors: Caffaro M. A. Grado , Caffaro M. Grado
Published: April 2008

In this communication, an accurate mathematical model for the noise figure of a high electron mobility
transistor is developed. This model represents a substantial improvement of the Fukui model. In fact,
the Fukui approach can be considered as an approximation of our model under certain conditions.
The fundamental relationship that gives minimum noise figure is derived from a first‐order linear
partial differential equation, which is established by assuming reasonable statements based on experience.
The Properties of Screen Printed (Bi,Pb)‐Sr‐Ca‐Cu‐O Thick Films Based OnDecomposed Oxalate Powders
Authors: Hagberg J.
Published: April 2008

The significance of powder and paste characteristics was studied in order to improve the morphology
and structure of superconducting (Bi,Pb)‐Sr‐Ca‐Cu‐O screen printed thick films. Powder with nominal
composition of Bi1.75Pb0.4Sr1.9Ca2.1Cu3.2Oy was prepared via the oxalate route and decomposed at 430 to
795℃. The decomposed powders were characterized by X‐ray diffraction, transmission electron microscopy
and specific surface area measurements. These studies showed a variation of specific surface
area from 16.5 to 0.9 m2/g and a variation of the average particle size from 100 nm to 800 nm in the
studied temperature interval. The phase structure showed three distinct temperature areas; between
430 to 620, 620 to 715, and at 795℃.

Thick‐film pastes were made by the addition of an organic vehicle at 500, 620, 650 and 795℃ to
decompose annealed oxalate synthesized powders and, for comparison, the vehicle was also added to
sintered mixed‐oxide/carbonate‐based powder in weight ratios from 0.42 to 0.54:1. Films were screen
printed on single crystal MgO (100) substrates and melt annealed at 890 to 895℃ for 3 min and
subsequently, for prolonged diffusion, annealed at 852℃. After firing, the films were mainly composed
of the (001) textured (Bi,Pb)2Sr2Ca2Cu3Oy phase. The reference films, made from mixed oxide/carbonate powder, resembled the films based on oxalate powders decomposed at 795℃. Films based on oxalate
powders, decomposed at lower temperatures, were smoother and were able to carry noticeably higher
currents than films based on powders decomposed at higher temperatures.
Thermal Placement in Hybrid Circuits—A Heuristic Approach
Authors: Kos A. , De Mey G.
Published: April 2008

This paper deals with the placement of heat dissipating components in hybrid circuits. An optimum
placement is found when the extreme temperatures on the substrate are minimized. Whereas classical
techniques such as the gradient method require large computational efforts, a simple and very rapid
heuristic method is presented here. The heuristic approach offers the advantage that it can be easily
inserted in the design phase of the circuit.
An OTA‐Based Digital‐To‐Analog Converter
Authors: Al-Ali A. R. , Abuelma′atti M. T. , Shabra A.
Published: April 2008

A simple circuit for implementing a current‐switching digital‐to‐analog converter is presented. The
circuit uses operational transconductance amplifiers (OTAs) for switching a number of equal‐value
current sources. An R‐2R ladder attenuator is used to scale the currents in a binary form. Experimental
results show good performance.
An Approximate Analysis and Its Application to The Non‐Linear Performance of Three Mosfet Transconductance Amplifiers
Authors: Abuelma′atti Muhammad Taher
Published: April 2008

A simple procedure for approximating the input‐output characteristic of non‐linear electronic circuits
is presented. Using this procedure, closed‐form analytical expressions, in terms of the ordinary Bessel
functions, are obtained for the output spectra of a non‐linear electronic circuit resulting from a multisinusoidal
input. Using these expressions, the non‐linear performance of three basic MOSFET transconductance
amplifiers is considered in an attempt to determine the transistor parameters for best
linearity.
A Brief Note on Coherent Feedback in Semiconductor Lasers
Authors: Caffaro M. A. Grado , Caffaro M. Grado
Published: April 2008

Some aspects on coherent feedback in a laser diode are investigated. In particular, weak optical feedback
is considered in the context of the feedback‐induced frequency shift. In addition, the Lang‐Kobayashi
equations are considered.
Computer‐Based Study of MCP‐Coupled Active Filters for Structures Like FLF, SCF, CBQ, and LF
Authors: Mital Prem Bhushan , Kumar Umesh
Published: April 2008

This paper deals with the problem of the realization of low sensitivity narrow BP active filter implementing
multiple critical pole approximation methods. Coupled active filter structures are also studied.

The position of a MCP (multiple critical pole) transfer function containing multiple poles is realized
as FLF (Follow the Leader Feedback) and and remaining part as cascade. Further MCP transfer functions
are combined with CBQ (Coupled Biquads), SCF (Shifted Companion Form), and LF (Leap Frog)
structure.
Comparative Study of Statistical Distributions inElectromigration‐Induced Failures of Al/Cu Thin‐Film Interconnects
Authors: Loupis M. I. , Avaritsiotis J. N. , Tziallas G. D.
Published: April 2008

In electromigration failure studies, it is in general assumed that electromigration‐induced failures may
be adequately modelled by a log‐normal distribution. Further to this, it has been argued that a lognormal
distribution of failure times is indicative of electromigration mechanisms. We have combined
post processing of existing life‐data from Al/Cu + TiW bilayer interconnects with our own results from
Al/Cu interconnects to show that the Log Extreme Value distribution is an equally good statistical
model for electromigration failures, even in cases where grain size exceeds the linewidth. The significance
of such a modelling is particularly apparent in electromigration failure rate prediction.
Influence of Multiple Trapping Phenomena on The Applications Criteria of ZnO‐Bi2O3‐Based Varistors
Authors: Alim Mohammad A.
Published: April 2008

The performance characteristics of the ZnO‐Bi2O3‐based varistors can be assessed to meet the applications
criteria on the basis of a systematic evaluation corresponding to various experimental conditions.
This evaluation process employs the lumped parameter/complex plane analysis technique for the ac
small‐signal immittance data. An overall behavior of these devices is attributed to the microstructural
effects via controlled grain‐size and its distribution, existence of phases, carrier density in the grains,
trapping states, and their role within the electrical thickness across the grain‐boundary electrical barrier,
etc. These factors are strongly dictated by the additives to ZnO in conjunction with the processing
variables. Multiple device functions can result when a single set from a variety of processing parameters
is chosen, provided the starting chemistry or composition/formulation remain invariant. The factors
related to materials′ history, composition recipe, and combined processing methods influence or modify
relative magnitudes of the constituting elements of each trapping relaxation. Thus, these magnitudes
either increase or decrease the visibility without distorting the devices′ generic dielectric behavior. An
identical set of experiments contributes to distinguish a good varistor performance over a poor response
for surge arrester (i.e., suppressor/absorber) applications in the power systems′ transient protection.
The New Phenomenon of Lithium Electrochemical (De)Intercalation inMineral Clay Materials and Their Potential Application inRechargeable Batteries
Authors: Wen Shi-Jie , Yin Xiao-Tian , Nazar L.
Published: April 2008

A new phenomenon of Li electrochemical (de)intercalation on the pure mineral clay materials has been
evidenced for the first time. These tests are initialized by the idea of putting an electronic conducting
polymer or a multi‐valent metal oxide in the layer of the clay to modify the electronic properties and
also to modulate the charge and discharge potential of the clay during the Lithium electrochemical
(de)intercalation processing. In this paper, as the beginning of our research, we will first show the
results of Lithium electrochemical charge and discharge processes on pure clay materials.
Analytical and Practical Study of Coupled Multivibrators
Authors: Kumar Umesh , Mital P. Bhushan
Published: April 2008

This paper investigates the dynamic behavior of a system of two multivibrators. It is shown that the
characteristics of synchronization states of multivibrators are coupled in a particular manner and their
approach to synchronization can be tackled analytically without approximations. This can be regarded
as an advancement, since most of the analytical work on coupled oscillators attain results only by
resorting to an approximate mathematical method.

It has been shown that the results obtained for coupled multivibrators are similar to those of sinusiodai
oscillators.

Such systems are important in the fields of theoretical biology, communication, radar system technology,
and coupled solar cells.
Evaluation of Bonding Orbitals in Amorphous Silicon by Means ofthe Chemical Pseudopotential Method
Authors: Caffaro M. A. Grado , Caffaro M. Grado
Published: April 2008

The chemical pseudopotential method has been used by a number of workers in order to study the
valence bands of amorphous tetrahedrally bonded semiconductors. However, various problems related
to this method are unsolved. In this paper, a theoretical formulation tending to clarify some of these.
problems is presented.
This formulation concerns bonding orbitals and is valid, in principle, for amorphous silicon.
Influence of the pH Values of the Sol–Gel State on the Properties of SnO2 Powders Obtained From a Sol–Gel Route
Authors: Han S. D. , Huang S. Y. , Campet G. , Kennard M. A. , Son Y. M.
Published: April 2008

The evolution of the specific surface area and crystallite size of SnO2 powders, prepared from a sol‐gel
process, was studied as a function of the calcination temperature of the stannic hydroxyde colloid, and
for two different pH values (7.5 and 12.5) of the colloïdal state. The samples were characterized by
TGA, IR spectroscopy, BET, and XRD techniques. The crystallite size and specific surface area were
strongly affected not only by the calcination temperature, but unexpectedly, by the initial pH value of
the colloïdal state. A framework model, relating the pH dependence to the resulting properties, is
presented.
New Current‐Mode Oscillators UsingUnity‐Gain Current‐Followers
Authors: Abuelma′atti Muhammad Taher
Published: April 2008

A catalog of current‐mode oscillator circuits using negative unity‐gain current‐followers is presented.
Each circuit uses two unity‐gain current‐followers, three resistors, and three capacitors . Simulation
results obtained from two new circuits are presented.
New Universal One‐Input Five‐OutputCurrent‐Mode Filter UsingCurrent‐Conveyors
Authors: Abuelma′atti Muhammad Taher , Farooqui Aamir Alam
Published: April 2008

A new universal active current‐mode filter with single input and five outputs is presented. The
proposed filter avoids the use of feedback in any part of the circuit and uses only grounded resistors
and grounded capacitors. The proposed circuit can simultaneously realize lowpass, highpass, bandpass,
allpass, and notch biquadratic filter functions.
Economical and Accurate DigitallyProgrammable Dual‐PolarityGain Amplifier
Authors: Rathore T. S. , Jain L. C.
Published: April 2008

A digitally programmable, dual‐polarity gain amplifier is proposed. It uses total resistance less than
those presented earlier. The effect of on‐resistance of switches can be fully compensated.
Design, Fabrication, and Comparative Study of Electronically Tunable Active Filters
Authors: Kumar Umesh , Mital P. Bhushan
Published: April 2008

The Kerwin‐Huelsman Newcomb (KHN) biquad is the natural choice for use as a ‘universal’ filter building block out of the several existing 3‐amplifier biquadratic filter sections based on the two integrator loop or state variable realization of 2nd order systems. A modified version of the KHN
biquad, which is electronically tunable almost linearly over a decade range of center frequency, is
presented. For electronic tunability, instead of the direct use of a FET as a voltage variable resistance
to control the time constants of the integrators, a novel approach of using voltage‐controlled variable‐gain
amplifiers at the inputs of both the integrators and one immediately after the input signal has been
suggested. The circuit is suitable for use as a tunable universal filtering module and can be easily
digitally programmed.

Comparative treatment of general tuning methods of active filters, and some methods of electronic
tuning of active filters are discussed. A brief description of tuning algorithms of active filters is also
given.
Current‐Mode Grounded‐Capacitor Single‐Element‐Controlled Bandpass and Lowpass Filters
Authors: Abuelma′atti Muhammad Taher
Published: April 2008

New circuit configurations for realizing bandpass and iowpass current‐mode second‐order filters are
proposed. Each configuration uses a single first‐generation current conveyor, a transconductance amplifier,
three grounded capacitors, and two resistors at most. The parameters ω0 and ω0/Q0 of the
bandpass and lowpass realizations are not interdependent and, therefore, single element control of the
bandpass and lowpass characteristics is possible. Also, the feasibility of realizing a single element current‐controlled
sinusoidal oscillator is considered.
Programmable Voltage‐Mode Multifunction Filter Using Two Current Conveyors and One Operational Transconductance Amplifier
Authors: Abuelma′atti Muhammad Taher , Quddus Azhar
Published: April 2008

A new voltage‐mode active‐filter with single input and three outputs is presented. The parameters of the proposed filter are programmable and the filter uses grounded capacitors. The proposed circuit can simultaneously realize lowpass, highpass, and bandpass biquadratic filter functions and enjoys low temperature sensitivities.
New High‐Speed a‐Si/c‐Si‐ and a‐SiC/c‐Si‐Based Switches
Authors: Dimitriadis E. I. , Girginoudi D. , Georgoulas N. , Thanailakis A.
Published: April 2008

The electrical and optical characteristics of the new high‐speed Al/a‐Si/c‐Si(p)/c‐Si(n+)/Al and Al/a‐SiC/c‐Si(p)/c‐Si(n+)/Al optically controlled switches are presented in this paper. These switches exhibit the lowest ever reported values of rise and fall times, for this kind of switches, of about 3ns. They also exhibit a temperature and light reversibly controlled forward breakover voltage (VBF), together with high values of light triggering sensitivity.