bluuebunny/crossref_metadata_2025 huggingface dataset:
40
Ar/
39
Ar thermochronological constraints on the cooling and exhumation history of the South Tibetan Detachment System, Nyalam area, southern Tibet
Authors: Wang Yu , Li Qi , Qu Guosheng
Published: April 2008

The Nyalam detachment is part of the east-west striking South Tibetan Detachment System exposed in the Nyalam area, southern Tibet. Seventeen muscovite and biotite
40
Ar/
39
Ar age spectra and three K-feldspar multidiffusion domain modelling and cooling ages are presented for metamorphic rocks, leucogranite, granite and mylonite, collected from the Nyalam detachment and surrounding areas. The majority of the
40
Ar/
39
Ar results are cooling ages related to exhumation, which therefore place important constraints on formation of the Nyalam detachment and exhumation history of the region. Muscovite
40
Ar/
39
Ar ages from mylonite within the normal fault system and from the footwall of the fault are 16.1–15.2 Ma. Biotite
40
Ar/
39
Ar ages from the same samples are 15.6–14.8 Ma, slightly younger than the muscovite cooling ages. K-feldspar multidiffusion domain modelling suggests that samples collected from both mylonite on the fault surface and from footwall rocks underwent rapid cooling between 16.1 Ma and 11.7 Ma.

Ages and cooling histories in the Nyalam detachment and Greater Himalayan metamorphic sequence have similar characteristics and time constraints: the K-feldspar modelling indicates a sudden change in cooling rates for these regions during 15.5–14.0 Ma and
c.
12 Ma, respectively. Taking the regional thermal history into account, cooling could be associated with significant northward surface movement triggered by detachment normal faulting in the Nyalam area. The Nyalam detachment and Greater Himalayan metamorphic sequence experienced similar cooling and exhumation histories during
c.
17.0–11.7 Ma. Formation of the Nyalam detachment may have accompanied the southward extrusion of the Greater Himalaya zone along shear zones formed in response to underthrusting of the Indian plate beneath southern Tibet.
Crustal structure, restoration and evolution of the Greater Himalaya in Nepal-South Tibet: implications for channel flow and ductile extrusion of the middle crust
Authors: Searle M. P. , Law R. D. , Jessup M. J.
Published: April 2008

Recent suggestions that the Greater Himalayan Sequence (GHS) represents a mid-crustal channel of low viscosity, partially molten Indian plate crust extruding southward between two major ductile shear zones, the Main Central thrust (MCT) below, and the South Tibetan detachment (STD) normal fault above, are examined, with particular reference to the Everest transect across Nepal-south Tibet. The catalyst for the early kyanite ± sillimanite metamorphism (650–680°C, 7–8 kbar, 32–30 Ma) was crustal thickening and regional Barrovian metamorphism. Later sillimanite ± cordierite metamorphism (600–680°C, 4–5 kbar, 23–17 Ma) is attributed to increased heat input and partial melting of the crust. Crustal melting occurred at relatively shallow depths (15–19 km, 4–5 kbar) in the crust. The presence of highly radiogenic Proterozoic black shales (Haimanta-Cheka Groups) at this unique stratigraphic horizon promoted melting due to the high concentration of heat-producing elements, particularly U-bearing minerals. It is suggested that crustal melting triggered channel flow and ductile extrusion of the GHS, and that when the leucogranites cooled rapidly at 17–16 Ma the flow ended, as deformation propagated southward into the Lesser Himalaya. Kinematic indicators record a dominant south-vergent simple shear component across the Greater Himalaya. An important component of pure shear is also recorded in flattening and boudinage fabrics within the STD zone, and compressed metamorphic isograds along both the STD and MCT shear zones. These kinematic factors suggest that the ductile GHS channel was subjected to subvertical thinning during southward extrusion. However, dating of the shear zones along the top and base of the channel shows that the deformation propagated outward with time over the period 20–16 Ma, expanding the extruding channel. The last brittle faulting episode occurred along the southern (structurally lower) limits of the MCT shear zone and the northern (structurally higher) limits of the STD normal fault zone. Late-stage breakback thrusting occurred along the MCT and at the back of the orogenic wedge in the Tethyan zone. Our model shows that the Himalayan-south Tibetan crust is rheologically layered, and has several major low-angle detachments that separate layers of crust and upper mantle, each deforming in different ways, at different times.
Normal-sense shear zones in the core of the Higher Himalayan Crystallines (Bhutan Himalaya): evidence for extrusion?
Authors: Carosi R. , Montomoli C. , Rubatto D. , Visonà D.
Published: April 2008

Recent fieldwork in western Bhutan, dedicated to unravelling the tectonic structure of the mid-crustal rocks, indicates a complex deformation pattern in the Greater Himalayan Slab (GHS). A system of normal shear zones, striking NE-SW and steeply to moderately dipping to the SE, has been recognized within this extruding slab or wedge of crystalline rocks. The zones are characterized by well developed shear-sense indicators pointing to a top-down-to-SE sense of shear. The main Barrovian metamorphic minerals are bent and stretched by extensional shear bands and associated deformation mechanisms indicate a range of brittle-ductile deformation conditions. Normal shear zones are concentrated in the middle-upper part of the GHS and indicate a thrust-transport-parallel lengthening of the core itself. Vorticity analysis highlights a non-coaxial flow with pure and simple shear acting together during deformation (mean vorticity number bracketed between 0.63 and 0.76). These data, when compared to available data near the tectonic boundaries of the GHS, indicate an increasing component of pure shear towards the interior of the GHS. The ages of zircon overgrowths and monazites from a slightly deformed granite, 20.5 ± 0.5 Ma, and a mylonitic granite deformed into the shear zones, 17.0 ± 0.2 Ma, bracket the age of shear zone formation at close to 17 Ma. According to our data, the normal shear zones could well accommodate the pure shear component of deformation localized in the inner part of the extruding wedge/slab and is compatible with a channel flow model.
Unrest in Long Valley Caldera, California, 1978–2004
Authors: Hill David P.
Published: April 2008

Long Valley Caldera and the Mono-Inyo Domes volcanic field in eastern California lie in a left-stepping offset along the eastern escarpment of the Sierra Nevada, at the northern end of the Owens Valley and the western margin of the Basin and Range Province. Over the last 4 Ma, this volcanic field has produced multiple volcanic eruptions, including the caldera-forming eruption at 760 000 a
bp
and the recent Mono-Inyo Domes eruptions 500–660 a
bp
and 250 a
bp
. Beginning in the late 1970s, the caldera entered a sustained period of unrest that persisted through the end of the century without culminating in an eruption. The unrest has included recurring earthquake swarms; tumescence of the resurgent dome by nearly 80 cm; the onset of diffuse magmatic carbon dioxide emissions around the flanks of Mammoth Mountain on the southwest margin of the caldera; and other indicators of magma transport at mid- to upper-crustal depths. Although we have made substantial progress in understanding the processes driving this unrest, many key questions remain, including the distribution, size, and relation between magma bodies within the mid-to-upper crust beneath the caldera, Mammoth Mountain, and the Inyo Mono volcanic chain, and how these magma bodies are connected to the roots of the magmatic system in the lower crust or upper mantle.
Faults and ground uplift at active calderas
Authors: Folch A. , Gottsmann J.
Published: April 2008

Subsurface volume and pressure increases triggering surface inflation at active calderas are generally deduced by inverting ground-deformation time-series using isotropic and homogeneous half-space models (IHM). These models represent simplified mathematical analogues of the mechanical behaviour of the Earth’s crust. Using three-dimensional numerical modelling, we show that lateral discontinuities such as intracaldera- or caldera-ring-faults can significantly amplify and distort the ground deformation pattern during unrest. As a consequence, data inversions using IHMs, which do not consider lateral discontinuities, can provide erroneous results on causative source parameters. We also find that the degree of amplification and distortion in the form of abrupt changes in displacement/distance gradients in proximity to faults is dependent on source geometry. Prolate bodies represent a particularly critical geometry for which pressure increases may be overestimated by a factor of up to three. Our 3D analysis suggests that amplification effects can be much larger than predicted by earlier 2D models. We validate theoretical results by applying our model to investigate the effect of boundary faults and source geometries on the displacement field during ground uplift at the restless calderas of Campi Flegrei (Italy) and Sierra Negra (Galapagos Islands, Ecuador). Based on the discrepancy in results from IHMs and our numerical model, we argue that employing IHMs for inversion of ground displacement and gravity time-series may in some cases lead to a biased assessment of hazards associated with ground uplift.
The search for magma reservoirs in Long Valley Caldera: single versus distributed sources
Authors: Battaglia M. , Vasco D. W.
Published: April 2008

Long Valley Caldera and the Mono-Inyo Craters chain form a large volcanic complex in eastern California that has experienced persistent earthquake activity and ground uplift over the past 25 years. The central part of Long Valley Caldera (an area of more than 100 square km) has been slowly rising since 1980 at an average rate of 3 cm a
−1
. Inversion of micro-gravimetry and deformation data using a single vertical prolate ellipsoid source has helped to define the existence of a relatively shallow (5–8 km) silicic magma intrusion of 0.11–0.19 km
3
beneath the caldera’s resurgent dome. We use the information from the single-source inversion to constrain a more general three-dimensional distribution of volume changes in the subsurface. The distributed inversion identifies two main inflation areas beneath the resurgent dome: one following the regional trend of north-south faults, and another in the dome’s southern section, parallel to a strike-slip fault that is responsible for most of the seismic activity in the caldera’s south moat.
Evaluating the impact of quarrying on karst aquifers of Salento (southern Italy)
Authors: Delle Rose M. , Parise M. , Andriani G. F.
Published: April 2008

This paper describes a case study in the Salento karst (Apulia, southern Italy) in a site that has been intensively used to quarry limestones in the last 30 years. After quarrying activity had stopped, the site was transformed into legal and illegal landfills where solid and liquid wastes have been repeatedly dumped, with serious consequences for the groundwater resources. In this paper, through a geological, petrographical and hydrogeological approach, we attempt to assess the consequences of the anthropogenic activities on the local hydrogeology, with particular regard to the surficial aquifer that is contained in the Plio-Quaternary calcarenites cropping out in the area. Application of some well-known methods to assess the vulnerability of aquifer systems to contamination by human activities (DRASTIC, SINTACS, LeGrand and GOD) highlights the limits of such an approach in karst environment, and the necessity to include in the methods data strictly related to the peculiarity of karst. This is further evidenced by application of the EPIK method, specifically designed for karst areas. The final part of the paper focuses on the need of a thorough understanding of the hydrogeological setting for a better management and policy action of karst environments.
Biotic versus abiotic calcite formation on prehistoric cave paintings: the Arcy-sur-Cure ‘Grande Grotte’ (Yonne, France) case
Authors: Chalmin E. , d'Orlyé F. , Zinger L. , Charlet L. , Geremia R. A. , Orial G. , Menu M. , Baffier D. , Reiche I.
Published: April 2008

The ‘Grande Grotte’ cave at Arcy-sur-Cure (Yonne, France) with its prehistoric paintings shows important calcite concretions. Two types of calcite have been observed on the wall: translucent yellowish layers and opaque white or grey layers that completely obstruct the paintings. Other calcite types are present in the lakes of the cave (floating calcite rafts at the surface of the lake and soft calcite at the bottom of the lake).

The morphology of the different calcites was observed at different scales by optical microscopy with normal and polarized light, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The elemental composition was measured by using particle-induced X-ray emission (micro-PIXE) and the structure by X-ray diffraction (XRD), infrared (FT-IR) and Raman spectroscopy. The bacterial diversity and its role in calcite formation were assessed by culture and 16S-SSCP in order to distinguish and to assess various abiotic and biotic formation mechanisms.

The investigation of calcite characteristics enables conclusions on the formation mechanism and on a biotic or abiotic origin of the calcites. The change of calcite types on the walls reveals changes of the environmental cave parameters. In addition, interactions of calcites with the prehistoric paint layer could be evaluated.
Magnetic prospection as an efficient tool for doline detection: a case study in the central Ebro Basin (northern Spain)
Authors: Mochales T. , Pueyo E. L. , Casas A. M. , Soriano M. A.
Published: April 2008

The presence of alluvial dolines in the Ebro Basin causes problems to both agricultural and urban areas. At present, new urbanization of former farming areas requires new tools to detect karst zones and so diminish the hazard linked to collapses. In the surroundings of Zaragoza, dolines (developed mainly on Quaternary alluvial terraces covering a Tertiary gypsum substratum) are commonly filled with alluvial deposits, agricultural soils, urban debris, etc. Measurements of magnetic susceptibility show a remarkable contrast between host rocks and cavity fillings, demonstrating the value of magnetic surveying. A field test was made in a recently collapsed (September 2003) doline filled currently with urban debris. A magnetic survey was carried out following a 130 m
2
grid, with 1–10 m spacing between profiles. A proton magnetometer with gradiometer was utilized, and the total field intensity and gradient measurements were taken. The magnetic survey demonstrated a strong anomaly with a dipole defined by more than 650 nT and a gradient of about 100 nT m
−1
. The 2.5-dimensional (2.5D) modelling of the magnetic anomaly fits well with the known geometrical data. Two other dolines (that are not clearly defined at the surface) were also detected during the survey. These results validate the starting hypothesis and open a new research approach to the problem. The magnetic survey output allows the construction of realistic geological models.
Coastal karst geomorphosites at risk? A case study: the floods of 6–11 December 2004 in central-east Sardinia
Authors: Cossu A. , De Waele J. , Di Gregorio F.
Published: April 2008

Extreme rainfall causing floods and great damage occurred in many areas of central-east Sardinia in the period 6–11 December 2004. A total of approximately 700 mm of rain was measured during this extreme event, with a maximum reaching 510 mm of rainfall in 1 day at the rain gauge of Villagrande (Ogliastra). During and immediately after the event all fluviokarstic canyons were activated for at least 1 week, reaching the highest water levels in at least 50 years and reversing great quantities of sediment-loaded water onto the coast and with important geomorphical modifications. There was public fear that serious damage to the natural resources would occur, such as the famous Cala Luna beach that was almost completely destroyed by the flooding of the Codula Ilune River and by the coinciding sea storm. The river, in fact, eroded the longshore bar (beach) and destroyed the small backshore lagoon. A monitoring study has been initiated in order to analyse the natural evolution of this littoral system and to define the resilience of this interesting geomorphosite. The observations have shown that the flood, albeit impacting negatively in the moments immediately after the disaster, almost completely restored the natural equilibrium of this coastal karst geo-ecosystem within a season.
Contributory area definition for groundwater source protection and hazard mitigation in carbonate aquifers
Authors: Gunn J.
Published: April 2008

Carbonate aquifers provide important sources of potable water but are known to be particularly prone to pollution owing to rapid transfer of pollutants from the surface to springs or boreholes. Source protection zones and groundwater vulnerability maps are commonly used to mitigate against the pollution hazard but cannot be applied simplistically to carbonate aquifers, which are usually highly heterogeneous with overlapping groundwater divides that may vary with water levels. Divergent flow and disjunct contributory areas provide further complexity. Under these conditions, water-tracing experiments, repeated under different flow conditions, are the only tool capable of identifying those areas that contribute recharge to a particular source. Examples of water pollution affecting disjunct and overlapping source contributory areas are presented from the Waitomo area (New Zealand), Cuilcagh Mountain (Ireland) and the Peak District (UK). Source protection zones (SPZ), that have been defined by the Environment Agency in the Buxton area of the Peak District using equivalent porous medium models, are shown to be deficient. Further water-tracing experiments are essential if carbonate aquifers are to be adequately protected from pollution.
Treatment of Various Surfaces with Silver and its Compounds for Topical Wound Dressings, Catheter and Other Biomedical Applications
Authors: Djokic S.
Published: April 2008

The applications of surfaces treated with silver and its compounds include devices used as topical wound dressings, urinary catheters, endotracheal tubes, cardiac valves etc. Treatment of surfaces e.g. textile, polymers or metals with silver or its compounds is carried out to achieve the antimicrobial action of silver ions. Several approaches of surface treatment of medical devices for the antimicrobial purposes, such as electrodeposition, electroless deposition, physical vapor deposition, γ - radiation, etc. have been used in practice. It is clear that only silver ions are responsible for the antimicrobial activity. As confirmed experimentally, only samples containing silver compounds can deliberate silver ions in the tested media and exhibit antimicrobial activity both in vitro and in vivo. There is no evidence that elemental silver, even its so-called "nano-crystalline" state, exhibits an antimicrobial activity. Consequently, the devices coated with "nano-crystalline" silver should carefully be taken into consideration before the application.
Electrochemical Synthesis of Oxidants in Dilute Sulfate Solutions and Active Oxygen Donor Determination
Authors: Khubutiya Mogely S. , Kolesnikov Vladimir A. , Evseev Anatoly K. , Volkov Alexander G. , Abakumov Mikhail M. , Shibaev Alexander N. , Goldin Mark M.
Published: April 2008

Anodic oxidation of dilute solutions of sodium sulfate was developed to generate oxidants into aqueous solutions with a diaphragm electrolyzer, which consisted of titanium anodes covered with mixed oxides of iridium, ruthenium and tin, a titanium cathode, and Teflon cation-exchange membrane. An electronic device was created for continuous self-purification of cathode surface from hardness salt deposits. The anodic products of electrolysis were molecular oxygen and sodium persulfate. It should be noted that sodium persulfate was the only active oxidant. The synthesized anolyte was tested for its oxidizing activity towards certain metabolites and toxicants. Disinfecting properties of anolyte were detected towards gram-positive and gram-negative bacteria. The comparison of redox potentials of commercial samples of persulfate and the synthesized anolyte showed that the redox potential value for the anolyte is much higher than for solutions with the same concentration of commercial persulfate.
Coating of High Density Polyethylene (HDPE) with Silver Compounds and Their Antimicrobial Activity in vitro
Authors: Djokic Nada , Precht Rod , Djokic S.
Published: April 2008

Antimicrobial activity of HDPE coated with Ag7O8NO3, Ag2O, Ag2CO3, Ag2SO4, etc. and their antimicrobial efficacy was investigated in comparison with commercially available materials containing silver and/or silver compounds. Both cidal and static activities of HDPE treated with silver compounds was investigated in vitro. For this purpose, gram positive organisms, e.g. Staphylococcus aureus, or gram negative organisms, e.g. Pseudomonas aeruginosa, or fungi, e.g. Candida albicans, were used. Samples prepared in this work have shown a strong antimicrobial activity against tested micro-organisms. The strong antimicrobial activity of silver oxysalt coated HDPE was attributed to the presence of higher oxidation states of silver ions e.g. Ag2+ and/or Ag 3+. The results have clearly shown that the coated samples produced in the present work exhibited comparable or even better antimicrobial behaviour than commercially available samples which contained significantly higher levels of silver.
EIS Study of the Electrochemical Behavior of the Co-Cr-Mo Alloy in Borate Solutions
Authors: Montero-Ocampo Cecilia , Hidalgo Badillo Joaquín
Published: April 2008

This paper presents the results of EIS experiments performed to examine the passive state of Co-Cr-Mo alloy produced in borate buffer solutions of different pH values between 4.6 and 12.5 at rest potential. An equivalent circuit model was used for the quantification of the Co-Cr-Mo passive film properties obtained as function of solution pH. From this study, the solution pH which gives rise to the best passive protective properties was established to carry out the electropassivation of Co-Cr-Mo alloy at different potentials selected from the polarization curve. EIS experiments were implemented to evaluate the resultant passive state of Co-Cr-Mo alloy as function of the electropassivation potential. An equivalent circuit model used for measuring the Co-Cr-Mo passive film properties produced at these different electropassivation potentials shows that thicker and more resistant passive films were obtained using passivation potentials negative of the peak potential, 0.477 V presented in the anodic polarization curve.
Modification on the Electronic Structure of Organic Semiconductor by Alkali Metal
Authors: Ding Huanjun J. , Gao Yongli
Published: April 2008

The electronic structure modifications of organic semiconductors by alkali metal doping have been investigated with photoemission and inverse photoemission spectroscopy. We have found that the doping induces energy level shift that can be seen as in two different stages. The first stage is predominantly due to the Fermi level moving in the energy gap as a result of the doping of electrons from the alkaline metal to the organic, and the second stage is characterized by the significant modification of organic energy levels such as the introduction of a new gap state, new core level components. Furthermore, by adding an opposite dopant, such as Au or oxygen, the doping induced energy level shift can be partially recovered, which suggests that the doping process in organic semiconductors is mainly due to charge transfer.
Electronic Structure of Interfaces Between Hexadecafluoro-phthalocyanine and 2,5-bis(4-biphenylyl) Bithiophene
Authors: Ding Huanjun J. , Wang Haibo , Yan Donghang , Gao Yongli
Published: April 2008

The interfaces formed between copper-hexadecafluoro-phthalocyanine (F16CuPc) and 2,5-bis(4-biphenylyl) bithiophene (BP2T) were examined using photoemission and inverse photoemission spectroscopy. It is observed that in F16CuPc/BP2T the heterojunction is characterized by band bending in both materials, while in BP2T/F16CuPc the band bending is confined in BP2T only. The combination of the band bending and finite Debye lengths provides an explanation to the observed ambipolar behavior of the organic thin film transistors based on such heterojunctions.
Polymer Thin-Film Transistors with Chemically Modified Dielectric Interfaces by Atmospheric-Pressure Plasma Technology
Authors: Kow-Ming Chang , Chih-Hsiang Lin , Shi-Xuan Huang
Published: April 2008

Poly-3-hexylthiophene (P3HT) is coated on a chemically modified SiO2 gate dielectric layer as an active layer to fabricate organic thin-film transistors (OTFTs). This study uses a new atmospheric-pressure plasma (APP) approach to treat SiO2 surfaces, and investigates its effect on the electric characteristics of OTFTs. The APP process can be performed at low temperature (<100ºC) and atmospheric pressure, so it is very suitable for use on a plastic substrate. After the SiO2 surface has been modified by the APP process with hexamethyldisilazane (HMDS), it exhibits typical I-V characteristics of TFTs. Calculations reveal that its field effect mobility can reach 0.02-0.03 cm2/Vs, which is about 15 times higher than that before the modification, and the threshold voltage is below -10V. The performance is even better than that obtained following the usual surface treatment of the SiO2 surface by spin-coating or evaporation.
Improved Parylene-Packaged Pentacene Thin-Film Transistors
Authors: Lo Hsi-wen , Tai Yu-Chong
Published: April 2008

This paper presents improved parylene-packaged thin-film transistors. Several spin-cast dielectrics were investigated to improve the surface roughness of parylene. The corresponding mobility and performance of pentacene thin film transistors were also reported. The relation between pentacene grain sizes and roughness of surfaces where pentacene grows were also investigated. To further improve the mobility, micromachined shadow masks made of silicon and parylene were employed to define the source and drain contacts. The improved pentacene thin-film transistor has a mobility of 0.2 cm^2/V-s and an on/off ratio of 10000.
Low Temperature Processes of Organic Thin Film Transistor with Gate Dielectric of Silicon Dioxide Deposited by Scanning Atmospheric-Pressure Technology
Authors: Chang Kow-Ming , Huang Shih-Syuan , Lin Chih-Hsiang , Huang Song Hong , Wu Yong Mao , Pan H.C. , Hsu Ming I
Published: April 2008

We have fabricated successfully pentacene-based thin film transistor with silicon oxide as a gate dielectric deposited by scanning atmospheric-pressure plasma technology (SAPPT) at a low temperature process. The major merit of scanning atmospheric-pressure plasma technology (SAPPT) suitable for the application of flexible electrons was low-temperature deposition under an atmospheric pressure. A low operation voltage is less than -5V and the leakage current of silicon oxide dielectric is about 2.5E-8 A/cm2 at 0.5 MV/cm.
Mist Deposition of Organic Semiconductors for Light Emitting Diodes
Authors: Shanmugasundaram Karthik , Price Steven , Li Wenguang , Jiang Hua , Wang Qingwu , Ruzyllo J.
Published: April 2008

In this work the process of mist deposition is explored as a method used to deposit organic semiconductors for applications in OLEDs. The deposition kinetics of a specially formulated hole transport agent (AG I) from Agiltron were studied. The results indicate that the mist deposited film thickness varies linearly with precursor concentration, deposition time, and substrate potential. AFM characterization shows distinct stages in the film evolution process. The growth of secondary layers was observed before the formation of a complete initial film layer. A working blue OLED with the hole transport and photo emissive layers deposited by mist deposition was demonstrated.
Evolution of the Microstructure and Performance of Pd/Ag ‐ BasedThick Conductors
Authors: Prudenziati Maria , Morten Bruno , Brigatti Maria Franca
Published: April 2008

Pd/Ag‐based inks are probably the most commonly used conductors in thick‐film hybrid technology. The
evolution of the microstructure of these films was studied on samples fired with isochronal cycles at a
peak temperature in the range from 300℃ up to 850℃. The samples were investigated by means of X‐ray
diffraction, SEM and EDAX analysis techniques; the results of these analyses as well as those of
thermogravimetry (TG, DTG) and differential thermal analysis (DTA), enable one to obtain a clear
picture of the complex evolution of the microstructure of these conductors, which correlates quite strictly
with the performance of the films in terms of resistivity and adhesion.

The relevance and limitations of each analytical technique for the examination of thick‐film conductors
are emphasized.
Comment on the Dependence of R□ and Current Noise on Grain Size inThick Film Resistors (TFR′s)
Authors: Wolf M. , Müller F. , Hemschik H.
Published: April 2008

The heterogeneous structure of TFR′s results in high resistivities and high current noise. Accepting models of
conduction in TFR′s, according to which the resistivity is determined by a resistance independent of bulk‐resistivity
of a metallic‐like component, it will be shown, that R□ and (describing current noise behaviour)
increase with d and d3, respectively, when d is the grain size. On the other hand, both quantities depend on the
volume fraction of the metallic component in the same manner. This leads to the conclusion, that a general
dependence in the form = f(R□) cannot exist.
Electrical Conductivity of Thin Wires
Authors: Dimmich R. , Warkusz F.
Published: April 2008

An expression for the electrical conductivity of thin metal wires of a circular cross‐section has been
derived taking account of conduction‐electron scattering at grain boundaries and the wire surface. An
angular‐dependent specularity parameter has been introduced and possible fluctuations of the wire
diameter along its length have been taken into account. Boltzmann transport equations have been solved
for the boundary conditions proposed by Dingle.
Preparation and Properties of a New Thick Film System
Authors: Inokuma T. , Taketa Yoshiaki , Haradome Miyoshi
Published: April 2008

Work has been carried out to develop a new ruthenium oxide based thick film resistor whose resistance is
independent of the contact area of the conductor to the resistor. Such a resistor can then be combined with a
low cost silver conductor.

It has been found that such a resistor can be made by doping a ruthenium oxide based thick film resistor
with up to several percent of gold. With such a material it is possible to use silver or palladium silver
(containing only very small amounts of palladium) as an electrode material and very few interactions have
been found to occur between the resistor and electrode. Such a gold doped ruthenium oxide thick film resistor
using silver electrodes has some major advantages as follows:‐

1. The resistor size can be made much smaller than normal.

2. The design of a thick film hybrid circuit becomes easier.

3. The resistor cost can be reduced.
Thick Film Resistors on Dielectrics as Temperature Detectors
Authors: Rzasa Benedykt , Potencki Jerzy
Published: April 2008

Thick film resistors made of typical ruthenate pastes on various dielectrics change their properties. The
properties of such resistors, fabricated on the TiO2 + glass dielectric, have been evaluated in this paper. The usability of the structures of the type conductor‐dielectric‐resistor for the construction of temperature sensors has been determined. A practical solution for the temperature sensor, in the form of an RC network with
distributed parameters, together with a circuit for the conversion of temperature into frequency has been presented.
Statistical Analysis of Data From Electronic Component Lifetests (ATutorial Paper)
Authors: Møltoft J.
Published: April 2008

Methods of statistically analysing data from electronic component lifetests are discussed. Particular emphasis is given to
analysis techniques using the assumptions of constant hazard rate (Exponential distribution), the Weibull distribution
and mixed Weibull distributions. The methods used for analysing Weibull data when the data itself is non‐uniform due
to both removal of test samples during test and also the non‐continuance of surveillance of components under test are
discussed. Attention is finally given to the effect of two or more failure mechanisms which can produce S‐shaped
patterns when data is plotted on Weibull Graph paper.

Numerous examples are given, mainly from the field of analysis of CMOS circuit components.
Low Temperature Firing of Pb‐Contained Thick Film Dielectrics
Authors: Fu Shen-Li , Chen Gung-Fun
Published: April 2008

The preparation and properties of the Pb(Fe1/2Nb1/2)0.86–xTi0.14O3‐based thick film dielectrics are
described. The Calcined Pb(Fe2/3W1/3)O3 powder, instead of glass frit, is used as the flux agent to promote densification
during the firing process. Firing is conducted at temperatures below 1000℃. The dissolution of Pb(Fe2/3W1/3)O3 into
the starting material and the segregation of Pb(Fe2/3W1/3)O3 along the grain boundaries result in two peaks in the
dielectric constant vs temperature behaviour. By controlling the amount of Pb(Fe2/3W1/3)O3 appropriately, the
temperature coefficient of capacitance may be improved. The average dielectric constant of the compositions prepared
range from 783 to 1639 1 at KHz. The loss factor can be reduced by adding small amounts of MnO2, and is below 2% at 1 KHz from –25℃ to +85℃. Microscopic observation and x‐ray diffraction analysis have also been conducted to
confirm the mechanism deduced for explaining the results.
Similarity Criteria of EHF Physical Model of Long Distance Transmission Line with Plate Phases
Authors: Hamed M.
Published: April 2008

Carson′s equations for computation of frequency dependent parameters of overhead
transmission line are modified. The earth is considered to be homogenous. The
optimal required number of terms of Carson′s series for applications on computer is
determined. Accurate mathematical expressions for resistance and inductance of
overhead transmission lines are obtained.

Different arrangements of conductors for double circuit transmission lines are
studied. The mutual inductance and potential coefficient (mutual capacitance) of such
arrangements are computed. Double voltage class type double circuit transmission
lines are suggested. The plate type double circuit lines are proposed for power transmission
over long distances.

This paper presents a mathematical analysis in order to determine the coefficients
of similarity criteria of EHF physical model for the given long distance transmission
line. The integral analogue method and PI‐theorem are used. The independent
parameters of EHF physical model are formulated. The scales of four independent
parameters of the designed EHF physical model are obtained.
Coupling Between Separate Phases of Coaxial Double Circuit Transmission Lines
Authors: Hamed M.
Published: April 2008

The paper studies the so‐called coaxial overhead transmission lines. The concentric
phases are considered. The mathematical analysis for voltage and current is presented.
The telegraphic equations of the double circuit power lines with the mutual
effect between circuits are introduced. The condition for single circuit transmission
line is checked. The mutual effect between both circuits is studied on the basis of the
ratio between the two currents of both circuits. The appeared phase shift between the
two vectors of currents is inserted in the investigation. The magnetic field intensity at
an external point of a line is mathematically expressed. Its value is approximated for
the purpose of zero mutual inductance between phases of the same circuit. The
mutual inductance between the two nearest groups of phases due to the linkage flux
for the studied line is formulated. Its dependency on the distance from the phases as
well as on the ratio of currents of both circuits is analysed. Then, the effect of phase
shift on the mutual inductance is investigated. An idea for the control of the ratio
between currents of both circuits of a line is presented.
Distortion Analysis of Active Filters
Authors: Kumar Umesh , Shukla Sushil Kumar
Published: April 2008

Second order active filters using single and two operational amplifiers at high frequencies
and/or large‐signal levels are investigated for their nonlinear performance. A general
procedure using the Volterra series in presented regarding intermodulation distortion.
Computer results by implementation in a program “Distortion Analysis” demonstrate
the accuracy of the analysis technique.
Study of Thick Film Resistors By 1/f Noise Measurements
Authors: Ambrózy A. , Hahn E. , Kiss L. B. , Trefán G.
Published: April 2008

Knowledge on the conduction mechanism of thick film resistors are limited and often
contradictory.

In this paper investigations based on temperature dependent 1/f noise measurements
are reported.
The Electrical Characteristics of Long Transmission Lines With External Forcing Impedance
Authors: Hamed M.
Published: April 2008

This paper presents a new idea for the radial type transmission line with external reactive forcing impedance
at only the receiving end. The general constants of such line are deduced. The effect of both capacitive and
inductive forcing impedances on the steady‐state performance of the proposed line are studied. The maximum
received power for a 1000 km line with capacitive forcing impedance is formulated. The rating of the suggested
1 k Ohm forcing capacitor for a 1000 km line is computed.
A Thick Film Sensing Element for True RMS Meter
Authors: Hrovat Marko , Zgonik Miran , Belavič Darko
Published: April 2008

A sensing element for true RMS meter was realized in thick film technology. The temperature gradient along
a substrate was measured by thick film thermocouples, based on a combination of Pt/Ag‐Pd/Ag, Pt/Au‐Au and
Ni‐Cr. A voltage response of the element was measured as a function of the current through the heating resistor
at different ambient temperatures. The transfer function K(T) of the RMS meter was found to be relatively
independent of ambient temperature, which means that the voltage response is usably linear.
Improvement of Mosfet Characteristics
Authors: Singh Ranbir
Published: April 2008

By inclusion of a semi‐dielectric layer, a novel MOSFET Structure, the T‐MOSFET, and its integrated
circuit version are presented. Both for the enhancement mode and the depletion mode, equivalent
circuit models are developed. Also, the high frequency behaviour is explained by a model and the
behaviour of a T‐MOSFET under different conditions is given.
Optical and Electrical Properties of SnO2:F Thin Films Obtained by R.F. Sputtering With Various Targets
Authors: Geoffroy C. , Campet G. , Menil F. , Portier J. , Salardenne J. , Couturier G.
Published: April 2008

Tin oxide films were deposited on glass substrates by reactive and non reactive r.f. sputtering using
different types of targets corresponding to various Sn/F atomic ratio: hot pressed Sn–SnF2 or
SnO2–SnF2 mixtures, ceramics obtained by casting either an aqueous SnO2–SnF2 slurry or a suspension
of tin oxide in molten tin fluoride. The samples were prepared in oxygen‐argon gas mixtures in which
the oxygen concentration was varied from 0 mole % up to 30 mole% depending on the target. The
optical and electrical properties of the obtained thin films have been studied and compared to those of
the films obtained by spray technique.
Size Effects in Ruthenium‐Based Thick‐Film Resistors: Rutile vs. Pyrochlore‐Based Resistors
Authors: Prudenziati M. , Sirotti F. , Sacchi M. , Morten B. , Tombesi A. , Akomolafe T.
Published: April 2008

The size effect, namely the change of sheet resistance, Rs as a function of resistor length, has
been investigated in layers whose conductive phase evolves from Pb‐rich (Ru‐deficient pyrochlores) to
Pb2Ru2O6.5 and finally to RuO2 by increasing the firing temperature. It is found that Bi diffusion from
the terminations is responsible for lower sheet resistance values in shorter resistors whatever the conductive
phase is. On the contrary, Ag diffusion is responsible for lower sheet resistance values in shorter
resistors only in the case of ruthenate conductive grains while the reverse is observed in RuO2‐based
layers. Size effect can be suppressed with Pt/Au‐based terminations provided that no Bi is contained
and with Au‐metallorganic‐based contact provided that the peak firing temperature is not too high.
Analysis of Multi‐Pin Modular Daughterboard‐to‐BackplaneConnectors at High Bit Rate Signals
Authors: Capsalis C. N. , Chronopoulos C. P. , Tigelis J. G. , Uzunoglu N. K.
Published: April 2008

A theoretical model for the electrical characterization of multi‐pin modular daughterboard‐to‐backplane
connectors at high bit rate signals is developed. The fundamental field equations are transformed into
a linear system of equations for the currents and voltages at the edges of the pins of the connector.

Efficient formulaes for the calculation of self and mutual inductances and capacitances between the
pins which are involved in the linear system of equations are obtained. Using the previous developed
theoretical model the connector′s performance can be examined in both the frequency and the time
domain.

Numerical calculations are performed for three types of existing connectors. Furthermore, they are
compared to each other for bit‐rates in the range of 100 Mbits/sec up to 500 Mbits/sec.
Comprehensive Summary of Performance‐Affecting Factors of CCDS
Authors: Kumar Umesh , Chaddha Navin
Published: April 2008

This paper considers four factors affecting the functioning of a surface channel CCD. The factors
considered are: the interface states, feed forward due to barrier modulation, surface potential fluctuations,
and the avalanche multiplication in a CCD. A computer program has also been developed to
analyze the performance of a CCD.
Effect of the Addition of Different Metal Oxides in Lead Borosilicate Glasses on the Electrical Characteristics of SbSn Composition‐Based Thick‐Film Resistors
Authors: Cubellio E. R. , Natu G. N. , Karekar R. N. , Aiyer R. C.
Published: April 2008

The paper reports the effect of addition of metal oxides in lead borosilicate glasses on electrical characteristics of SbSn alloy‐based thick‐film resistors. The Sb and Sn powder (1: 1 by weight) is taken in two quartz tubes separately, vacuum sealed at 10–5 Torr and heated in a resistive furnace .at 430℃ and 630℃ respectively. The conventional glass [1] is modified by using different dopants like tungsten oxide, cobalt oxide, lithium oxide, titanium dioxide, venadium pentoxide, chromium oxide, nickel oxide and manganese dioxide. The resistive pastes are formulated with both powders, 5% glass and conventional organic binder. The firing temperature is optimized for eight glasses. The sheet resistivity varies from 1600 Ω/□ to 40 Ω/□ , with negative temperature co‐efficient of resistance varying from 2000 ppm/℃ to 800 ppm/℃ respectively. Material characterization is carried out using the XRD technique. Aging studies of resistors at room temperature over the period of two months indicate that these resistors stabilize within 15–20 days.
Magnetic Shielding With High‐Tc (YBa2Cu3O7-δ)1-xAgx Superconducting Tubes
Authors: Castro H. , Holguín E. , Loude J. F. , Rinderer L.
Published: April 2008

We present typical results of experiments carried out in (YBaCuO)1-xAgx tubular samples, for different values of the silver concentration x, having in mind the possible use of this material as a magnetic
shield. We measured the times governing the dynamics of magnetic flux penetration, on a microsecond
time‐scale, and tried to correlate them with d.c. measurements of the resistivity and the critical transport
current density, using a simple theoretical model based on the flux‐flow régime.
An Algebraic Model for the Recombination Rate in Semiconductors
Authors: Caffaro M. A. Grado , Caffaro M. Grado
Published: April 2008

This paper consists of a new formalism in order to interpret the electron‐hole recombination rate in
semiconductors by means of linear algebraic methods; a formulation based on tensorial concepts introduced
in a unique way. The methodology introduced here represents an interesting tool to evaluate
certain properties of semiconductors from a theoretical point of view.
Influence of Time‐Dependent Power Dissipations on the AgeingBehavior of Thick‐Film Resistors
Authors: de Mey G. , Boone E. , De Tollenare G.
Published: April 2008

Reliability experiments on hybrid circuits are usually carried out by accelerated ageing test. The circuits
or the components under test are stored at an elevated ambient temperature and the change of their
electric properties is controlled at regular times. The situation becomes entirely different if the temperature
rise is due to the power dissipation in the component under test and not caused by external
means. In electronic circuits, power dissipations are expressed by a mean value, whereas the actual
situation is generally a time‐dependent function. The temperature will then also be time dependent.
Therefore, ageing tests on thick film resistors will be presented in this contribution. Resistors are
submitted to a DC power source and a pulse shaped one. Different ageing characteristics are observed.
High‐Tc Superconducting Electronics: Implications of Reduced Dimensionality
Authors: Bozovic I. , Eckstein J. N.
Published: April 2008

First, we present experimental evidence that Bi‐Sr‐Ca‐Cu‐O superconductors are effectively quasi‐two
dimensional, in both the normal and the superconducting state. Next, we analyze how this unusual
property of the material influences the quest for active electronic components based on high‐Tc superconductors,
with focus on trilayer Josephson junctions and ferroelectric/superconductor field‐effect
devices.
High‐Temperature Superconductors and Related Compounds Studied byMössbauer Spectroscopy
Authors: Kuzmann E. , Homonnay Z. , Nagy S. , Gál M. , Vértes A.
Published: April 2008

57Fe, 119Sn, and 151Eu Mössbauer spectroscopy was used to study the chemical structure, phonon mode
changes, and low‐temperature phase transformation around the Tc as well as suppression of superconductivity
in high‐temperature superconductors and related compounds. Anomalous temperature‐dependent
changes in the total 57Fe spectral area fraction and in the Mössbauer line shift were simultaneously
found around the Tc in a EuBa2(Cu0.9957Fe0.01)3O7-d superconductor. These anomalous changes
were attributed to phonon softening and low‐temperature phase transformation occurring around
the superconducting transition. Significant differences were observed between the 57Fe Mössbauer
spectra of superconducting EuBa2(Cu0.9957Fe0.01)3O7-d and the isostructural non‐superconducting
PrBa2(Cu0.9957Fe0.01)3O7-d. The differences were interpreted in connection with the suppression of superconductivity
(by hole filling or hybridization of Pr, Cu and O states) in the Pr‐containing compound.
The unusually high isomer shift value observed in the Pr‐containing material can give evidence for the
charge transfer mechanism between the Cu(1) chains and the Cu(2) planes and for its role in the
suppression of superconductivity.