bluuebunny/crossref_metadata_2025 huggingface dataset:
THE MATHER MEASURE AND A LARGE DEVIATION PRINCIPLE FOR THE ENTROPY PENALIZED METHOD
Authors: GOMES D. A. , LOPES A. O. , MOHR J.
Published: April 2011

We present the rate function and a large deviation principle for the entropy penalized Mather problem when the Lagrangian is generic (it is known that in this case the Mather measure μ is unique and the support of μ is the Aubry set). We assume the Lagrangian L(x, v), with x in the torus 𝕋Nand v∈ℝN, satisfies certain natural hypotheses, such as superlinearity and convexity in v, as well as some technical estimates. Consider, for each value of ϵ and h, the entropy penalized Mather problem [Formula: see text] where the entropy S is given by [Formula: see text], and the minimization is performed over the space of probability densities μ(x, v) on 𝕋N×ℝNthat satisfy the discrete holonomy constraint ∫𝕋N×ℝNφ(x + hv) - φ(x) dμ = 0. It is known [17] that there exists a unique minimizing measure μϵ, hwhich converges to a Mather measure μ, as ϵ, h→0. In the case in which the Mather measure μ is unique we prove a Large Deviation Principle for the limit limϵ, h→0ϵ ln μϵ, h(A), where A ⊂ 𝕋N×ℝN. In particular, we prove that the deviation function I can be written as [Formula: see text], where ϕ0is the unique viscosity solution of the Hamilton – Jacobi equation, [Formula: see text]. We also prove a large deviation principle for the limit ϵ→ 0 with fixed h.

Finally, in the last section, we study some dynamical properties of the discrete time Aubry–Mather problem, and present a proof of the existence of a separating subaction.
ORLICZ–HARDY SPACES ASSOCIATED WITH OPERATORS SATISFYING DAVIES–GAFFNEY ESTIMATES
Authors: JIANG RENJIN , YANG DACHUN
Published: April 2011

Let [Formula: see text] be a metric space with doubling measure, L a nonnegative self-adjoint operator in [Formula: see text] satisfying the Davies–Gaffney estimate, ω a concave function on (0, ∞) of strictly lower type pω∈(0, 1] and ρ(t) = t-1/ω-1(t-1) for all t∈(0, ∞). The authors introduce the Orlicz–Hardy space [Formula: see text] via the Lusin area function associated to the heat semigroup, and the BMO-type space [Formula: see text]. The authors then establish the duality between [Formula: see text] and [Formula: see text]; as a corollary, the authors obtain the ρ-Carleson measure characterization of the space [Formula: see text]. Characterizations of [Formula: see text], including the atomic and molecular characterizations and the Lusin area function characterization associated to the Poisson semigroup, are also presented. Let [Formula: see text] and L = -Δ+V be a Schrödinger operator, where [Formula: see text] is a nonnegative potential. As applications, the authors show that the Riesz transform ∇L-1/2is bounded from Hω, L(ℝn) to L(ω). Moreover, if there exist q1, q2∈(0, ∞) such that q1<1<q2and [ω(tq2)]q1is a convex function on (0, ∞), then several characterizations of the Orlicz–Hardy space Hω, L(ℝn), in terms of the Lusin-area functions, the non-tangential maximal functions, the radial maximal functions, the atoms and the molecules, are obtained. All these results are new even when ω(t) = tpfor all t ∈ (0, ∞) and p ∈ (0, 1).
THE QUANTITATIVE ANALYSIS ON THE FUCÍK SPECTRUM AND SOLVABILITY OF JUMPING NONLINEAR PROBLEMS
Authors: LI CHONG
Published: April 2011

In this paper, we give a quantitative description of the Fucík spectrum of -Δ with several technical conditions and get some results which improve considerably [5, Theorems 2.6 and 3.3]. The isomorphism between C*(J(a, b, f), ∞) and C*(J(a, b), 0) are obtained provided (a,b) ∉ ∑, which is exploited as a tool to generalize a result given by [14] without assuming λl being simple. Two applications are discussed.
FLUID DYNAMICS ANALYSIS OF SHEAR STRESS ON NERVE ENDINGS IN DENTINAL MICROTUBULE: A QUANTITATIVE INTERPRETATION OF HYDRODYNAMIC THEORY FOR DENTAL PAIN
Authors: LIN M. , LUO Z. Y. , BAI B. F. , XU F. , LU T. J.
Published: April 2011

Noxious thermal and/or mechanical stimuli applied to dentine can cause fluid flow in dentinal microtubules (DMTs). The fluid flow induces shear stress (SS) on intradental nerve endings and may excite pulpal mechanoreceptors to generate dental pain sensation. There exist numerous studies on dental thermal pain, but few are mathematical. For this, we developed a computational fluid dynamics (CFD) model of dentinal fluid flow (DFF) in innervated DMTs. Based on this model, we systematically investigated the effects of various parameters (e.g., biological structure, DFF velocity, and fluid properties) on the SS experienced by intradental nerve endings and thus provide a quantitative interpretation to the hydrodynamic theory. The dimensions of biological structures, odontoblastic process (OP) movement, dentinal fluid velocity, and viscosity were found to have significant influences on the SS while dentinal fluid density showed negligible influence under conditions studied. The results indicate that: (i) dental pain study of animal models may not be directly applied to human being and the results may even vary from one person to another and (ii) OP movement caused by DFF changes the dimension of the space for the fluid flow, affecting thus the SS on nerve endings. The present work enables better understanding of the mechanisms underlying dental pain sensation and quantification of dental pain intensity resulted from clinical procedures such as dentine sensitivity testing and dental restorative processes.
MICRO-FINITE ELEMENT ANALYSIS OF TRABECULAR BONE YIELD BEHAVIOR — EFFECTS OF TISSUE NONLINEAR MATERIAL PROPERTIES
Authors: GONG HE , ZHANG MING , FAN YUBO
Published: April 2011

Bone tissue material nonlinearity and large deformations within the trabecular network are important for the characterization of failure behavior of trabecular bone at both the apparent and tissue levels. Micro-finite element analysis (μFEA) is a useful tool for determining the mechanical properties of trabecular bone due to certain experimental difficulties. The aim of this study was to determine the effects of bone tissue nonlinear material properties on the apparent- and tissue-level mechanical parameters of trabecular bone using μFEA. A bilinear tissue constitutive model was proposed to describe the bone tissue material nonlinearity. Two trabecular specimens with different micro-architectures were taken as examples. The effects of four parameters, i.e., tissue Young's modulus, tissue yield strain in tension, tissue yield strain in compression, and post-yield modulus on the apparent yield stress/strain, tissue von Mises stress distribution, the amount of tissue elements yielded in compression and tension under compressive and tensile loading conditions were obtained using nine cases for different values of those parameters by totally 36 nonlinear μFEA. These data may provide a reference for more sophisticated evaluations of bone strength and the related fracture risk.
ARRHYTHMIA DISEASE DIAGNOSIS USING NEURAL NETWORK, SVM, AND GENETIC ALGORITHM-OPTIMIZED k-MEANS CLUSTERING
Authors: MARTIS ROSHAN JOY , CHAKRABORTY CHANDAN
Published: April 2011

This work aims at presenting a methodology for electrocardiogram (ECG)-based arrhythmia disease detection using genetic algorithm (GA)-optimized k-means clustering. The open-source ECG data from MIT-BIH arrhythmia database and MIT-BIH normal sinus rhythm database are subjected to a sequence of steps including segmentation using R-point detection, extraction of features using principal component analysis (PCA), and pattern classification. Here, the classical classifiers viz., k-means clustering, error back propagation neural network (EBPNN), and support vector machine (SVM) have been initially attempted and subsequently m-fold (m = 3) cross validation is used to reduce the bias during training of the classifier. The average classification accuracy is computed as the average over all the three folds. It is observed that EBPNN and SVM with different order polynomial kernel provide significant accuracies in comparison with k-means one. In fact, the parameters (centroids) of k-means algorithm are locally optimized by minimizing its objective function. In order to overcome this limitation, a global optimization technique viz., GA is suggested here and implemented to find more robust parameters of k-means clustering. Finally, it is shown that GA-optimized k-means algorithm enhances its accuracy to those of other classifiers. The results are discussed and compared. It is concluded that the GA-optimized k-means algorithm is an alternate approach for classification whose accuracy will be near to that of supervised (viz., EBPNN and SVM) classifiers.
BIOMECHANICAL PROPERTIES OF EXTENSOR TENDON REPAIR USING THE SIX-STRAND SINGLE-LOOP SUTURE TECHNIQUE: A COMPARATIVE ANALYSIS WITH THREE OTHER TECHNIQUES IN CADAVERIC MODELS
Authors: LIM BENG HAI , OOI LAI HOCK , CHOU SIAW MENG , GOH KHENG LIM
Published: April 2011

A six-strand single-loop technique has been implemented for repairing extensor tendons. This paper describes an investigation to compare the biomechanical properties of extensor tendons repaired using this technique with three other commonly used techniques, namely the Kessler-Tajima (two-stand) technique, the Tsuge (two-strand) technique, and the modified (four-strand and double-loop) Tsuge technique. Epitendinous stitches were implemented on all techniques. From human cadaveric hands, extensor tendons were harvested, transected, and repaired using these techniques. Tensile test was performed on the repaired tendons to determine the force at the first gap opening, 1-mm and 2-mm gap distances and at the maximum load. We have observed that at the first gap opening, the forces generated in the tendons repaired using the six-strand, Kessler-Tajima, and modified Tsuge techniques are significantly larger than the Tsuge technique. Thereafter, the force generated at gap distances of 1 mm, 2 mm, and the maximum force depend on the number of strands and the epitendinous stitches. In this case, the maximum force (31.80 N ± 4.73 N) from the six-strand technique is significantly higher than that from the Kessler-Tajima technique. In particular, all samples from the six-strand technique failed by suture pull-out. In contrast, suture pull-out is less common for the other techniques; these samples also exhibited suture rupture. This study is important because it reveals that cadaveric tendons repaired using the Kessler-Tajima, modified Tsuge, and six-strand techniques can accommodate higher initial forces (compared to the Tsuge technique) and, thus, are more effective for resisting gap formation. Among these techniques, it is shown that the six-strand configuration is reliable because the strands, rather than breaking, results in pull-out at sufficiently high loads. Thus, the six-strand approach for anchoring the ruptured tissue results in the transfer of large forces to the suture. It is suggested that the six-strand technique may be a viable technique since it requires only a single-loop suture and this may simplify the repair procedure and tendon handling without increasing the bulk of the repaired tendon appreciably.
BIFURCATION ANALYSIS AND CONTROL OF A PLANKTON–FISH MODEL WITH A DISTRIBUTION DELAY
Authors: ZHANG XUE , ZHANG QINGLING
Published: April 2011

This paper studies a plankton–fish model with distributed delay in the context of marine plankton interaction together with predation by planktotrophic fish. The delay indicates that the growth of the zooplankton depends on the past density of phytoplankton. The positive equilibrium point and its local stability are investigated. Using the average time delay as bifurcation parameter, we obtain the conditions of the existence of Hopf bifurcation. Based on the normal form and center manifold theorem, stability, direction, and other properties of bifurcating periodic solutions are derived. Moreover, a state feedback control method, which can be implemented by adjusting the harvesting for zooplankton population, is proposed to drive the plankton–fish system to a steady state. Numerical simulations illustrate the effectiveness of results and the related biological implications are discussed.
EFFECTS OF MOBILE PHONE RADIATION ON CARDIAC HEALTH
Authors: FAUST OLIVER , ACHARYA U. RAJENDRA , NERGUI MYAGMARBAYAR , GHISTA DHANJOO N , CHATTOPADHYAY SUBHAGATA , JOSEPH PAUL , AHAMED THAJUDIN , TAY DORITHY
Published: April 2011

Mobile phones (MPs) progressed from a tool of the privileged few to a gadget for the masses. However, the physical effects, which enable wireless information transmission, did not change; MP technology still relies on pulsed high-frequency electromagnetic (EM) fields. Therefore, the health risks, associated with EM fields, remain. Studies that investigated these health risks have reported dizziness, numbness in the thigh, and heaviness in the chest. This study investigates neurological effects that are caused by EM fields radiated from MPs. The heart rate variability (HRV) can be used as a measure for these neurological effects, because the automated nervous system modulates the HRV. We measured the HRV of 14 healthy male volunteers. We used the following nonlinear parameters to quantify the MP radiation effects on HRV: approximate entropy (ApEn), capacity dimension (CaD), correlation dimension (CD), fractal dimension (FD), Hurst exponent (H), and the largest Lyapunov exponent (LLE). The results indicate that there is a measurable difference in the parameter values when the MP is kept close to the chest and when it is kept close to the head. However, these differences are very small and statistical analysis showed that they have no clinical significance. Furthermore, the result analysis does not show a consistent trend, which indicates that there is no underlying pathological effect.
HUMAN REFLEXIVE RESPONSE AND ITS OBJECTIVE FUNCTION REGARDING BALANCE RECOVERY FROM PERTURBATION DURING WALKING
Authors: YIKEMOTO YU , YU WENWEI , ACHARYA U. RAJENDRA
Published: April 2011

Balance recovery from perturbation plays a crucial role in preventing people from falling during walking. Understanding the underlying mechanism of balance recovery during walking could not only bring new insights into the motor control field, but also benefit the development of walking assist systems for daily living environment, where perturbations to walking are frequently caused by slips, uneven terrain, slopes, obstacles, etc.

It is evident that humans can cope with such perturbations, especially when the perturbations cannot be predicted or perceived in advance, by means of reflexes, which cause relatively fixed, unconscious muscular response patterns to perturbations within a short period of time ranging from several tens of ms to 200 ms. However, except for several hypotheses about the underlying neural mechanisms of the reflexes during walking, there is no widely accepted unified theory.

In our previous study, a muscular-reflexive pattern was defined using muscle activity recorded during reflexive responses to slip perturbation. This is one important step toward the understanding of the underlying mechanism, since the pattern could serve as the quantitative target in pursuit of the underlying mechanism. We can speculate that this pattern is the optimal balance recovery behavior to human muscular-skeletal system, as a result of long evolution; however, before we use this target to guide our pursuit, we should first prove its optimality, while making clear the objective functions for balance recovery and the effect of morphological factors.

Our approach includes (1) defining objective functions for balance recovery from a slip perturbation during walking; (2) using a bio-mimetic human walking simulator to perform evaluation according to the objective functions; (3) employing a genetic algorithm (GA) to search the optimal solutions, for different objective functions.

Results showed that the muscular-reflexive pattern is optimal to the balance recovery from slip perturbation during walking, in terms of a hybrid evaluation measure (HEM), which takes both static and dynamic aspects of balance recovery into consideration.
GROUP SPECIFIC BEHAVIOR OF BIARTICULAR UPPER LEG MUSCLES EXEMPLIFIED BY SLEDGE
Authors: ERTELT THOMAS , BLICKHAN REINHARD
Published: April 2011

The biarticular skeletal muscles represent a much considered topic in current research. Concerning these muscles, not only Lombard's paradox is of special interest. Some authors refer to their energy-transferring function and others have observed an increase of activity in M. biceps femoris after a special training. By means of so-called sledge jumps, we have experimentally examined the behavior of M. biceps femoris for two groups, jumpers and non-jumpers, whose task was to push the sledge with different loads and different speeds. The results clearly show a specific behavior of the muscles for each group — which seems to affect the muscle coordination and has crucial influence on the shape of the ground reaction force. Due to nearly equal kinematic conditions, Lombard's paradox could apply for both groups. However, the amount of training seems to be an essential parameter. The jumpers activate the M. biceps femoris during the entire contact phase and during the shortening as well as the stretching of the leg. Thus the force shape becomes smoother and shows fewer fluctuations. Despite positive geometrical conditions, not all subjects use this muscle from the beginning of the movement. In this context, neural pathways, inhibitions or coupling processes are decisive factors. All that indicates that the controlling of the muscle can only be achieved by an appropriate training.
THE BOLTZMANN EQUATION WITHOUT ANGULAR CUTOFF IN THE WHOLE SPACE: II, GLOBAL EXISTENCE FOR HARD POTENTIAL
Authors: ALEXANDRE R. , MORIMOTO Y. , UKAI S. , XU C.-J. , YANG T.
Published: April 2011

As a continuation of our series works on the Boltzmann equation without angular cutoff assumption, in this part, the global existence of solution to the Cauchy problem in the whole space is proved in some suitable weighted Sobolev spaces for hard potential when the solution is a small perturbation of a global equilibrium.
SIMILARITY SOLUTIONS OF THE RAYLEIGH PROBLEM FOR OSTWALD–DE WAEL ELECTRICALLY CONDUCTING FLUIDS
Authors: BEDJAOUI N. , GUEDDA M. , HAMMOUCH Z.
Published: April 2011

We investigate in the present paper the magnetic Rayleigh problem, where a semi-infinite flat plate is moving with a power-law velocity, in a non-Newtonian power-law fluid (Ostwald–de Wael model). The non-stationary flow of this electrically conducting fluid in a transverse magnetic field is then analyzed. The solutions of this problem are obtained by means of similarity techniques. The main goal, is to investigate existence, uniqueness and behavior of such solutions, according to the values of the physical parameters.
EXACT AND APPROXIMATE TRAVELING WAVES OF REACTION-DIFFUSION SYSTEMS VIA A VARIATIONAL APPROACH
Authors: RODRIGO MARIANITO R. , MIURA ROBERT M.
Published: April 2011

Reaction-diffusion systems arise in many different areas of the physical and biological sciences, and traveling wave solutions play special roles in some of these applications. In this paper, we develop a variational formulation of the existence problem for the traveling wave solution. Our main objective is to use this variational formulation to obtain exact and approximate traveling wave solutions with error estimates. As examples, we look at the Fisher equation, the Nagumo equation, and an equation with a fourth-degree nonlinearity. Also, we apply the method to the multi-component Lotka–Volterra competition-diffusion system.
Crown ether functionalized texaphyrin monomers and dimers
Authors: Preihs Christian , Magda Darren , Sessler Jonathan L.
Published: April 2011

The synthesis and characterization of two 18-crown-6 functionalized analogues of an extensively studied gadolinium texaphyrin derivative, motexafin gadolinium (1, MGd), are reported. These are the monomeric and dimeric species, compounds 2 and 3, respectively. Both crown ether functionalized species proved to be stable at physiological pH and revealed distinct shifts in the UV spectrum when treated with sodium-, potassium-, ammonium- or zinc(II)-salts. Zinc(II) is believed to play a major role regulating apoptosis mechanisms in cancerous cells. Therefore, cytotoxicity studies of 2 and 3 were carried out using the Ramos cell line in the presence and absence of zinc(II).
PREPARATION AND MICROSTRUCTURAL CHARACTERIZATION OF NANOCRYSTALLINE Mn-DOPED ZnO
Authors: ROY B. , MONDAL O. , DEB A. , SENGUPTA S. P. , CHATERJEE P. , PAL M.
Published: April 2011

Mn -doped ZnO , a dilute magnetic semiconductor (DMS), has been prepared in nanocrystalline form by using a soft chemical route. The concurrent diffusional growth of both nanocrystalline Mn -doped ZnO and secondary spinel phase ZnMn2O4 in annealed samples have been studied by using a modified Rietveld method and transmission electron microscope (TEM). Rietveld analysis reveals that both the compounds start growing when Mn concentration is lower and the volume fraction of crystalline spinel phase ZnMn2O4 decreases sharply when Mn concentration increases. TEM study indicates that average particle sizes of both the phases are in nanometer dimensions and are highly crystalline in nature. Magnetization increases initially and then almost saturates with the increase of Mn concentration. The enhanced magnetization could be a combined effect of Mn ions and surface ferromagnetism of nanoparticles.
Episodic fluvial incision of rivers and rock uplift in the Himalaya and Transhimalaya
Authors: Dortch Jason M. , Dietsch Craig , Owen Lewis A. , Caffee Marc W. , Ruppert Kelly
Published: April 2011

Seventeen strath terraces in northern India were dated using
10
Be surface exposure methods; ages range from
c
. 7 to
c
. 735 ka and provide fluvial incision rates of 0.02 ± 0.003 to 2.6 ± 1.9 mm a
−1
. On the northern side of the Ladakh Range, incision rates are
c
. 1 mm a
−1
; in the northern Zanskar Range they are ≤0.06 ± 0.005 mm a
−1
. New and published incision rates in southernmost Lahul range from 0.1 ± 0.02 to 13.2 ± 6.2 mm a
−1
; rates for ages >35 ka are ≤0.4 ± 0.2 mm a
−1
. Across the Himalaya and Transhimalaya, Holocene fluvial incision rates range from
c
. 0.02 to
c
. 26.0 mm a
−1
, whereas Pleistocene incision rates are ≤5 mm a
−1
. Many of the Holocene incision rates exceed exhumation rates, whereas Pleistocene incision rates are comparable with exhumation rates. This suggests that long-term fluvial incision is in dynamic steady state with exhumation. The temporal pattern for rates of fluvial incision is probably controlled by episodic incision linked to significant precipitation changes throughout the Quaternary, suggesting that strath terraces with ages >35 ka can be used for assessing long-term rates of rock uplift. In contrast, rates of fluvial incision based on Late Glacial and Holocene strath terraces reflect changes in monsoon intensity and deglaciation events. By determining ages for multiple samples on flights of strath terraces, it is possible to document changes in incision rate, assess whether post-abandonment transient shielding has occurred, and help elucidate tectonic v. climatic controls on their formation.

Supplementary material:

Tables (DS1–4) for previously published data and recalculated ages for strath terraces, and figures (DS1 and DS2) showing plots of incision rates against time for the Himalaya and Transhimalaya are available at
http://www.geolsoc.org.uk/SUP18454
.
Assessing the catastrophic break-up of Briksdalsbreen, Norway, associated with rapid climate change
Authors: Hart Jane K. , Rose Kathryn C. , Waller Richard I. , Vaughan-Hirsch David , Martinez Kirk
Published: April 2011

Recent research has raised concerns about the potential influence of rapid climate change on the stability of major ice sheets. The behaviour of glaciers is determined largely by the processes and conditions operating at their base. Technological advances have allowed these factors to be examined and their contribution to ice flow constrained. This study investigated the rapid disintegration of an aquatic based Norwegian glacier, through the study of boreholes, video, ground-penetrating radar, differential global positioning system, bathymetry and Glacsweb wireless probes. Briksdalsbreen retreated dramatically between 2000 and 2007, with
c
. 56 × 10
5
m
3
of ice lost from the glacier tongue, equivalent to a rate of 70 m a
−1
. This was due to the combined effect of higher summer temperatures, decreased precipitation (resulting from a negative phase of the North Atlantic Oscillation) and increased fracturing of the glacier tongue. The enlargement of a proglacial lake played a key role in Brikdalsbreen's rapid retreat, allowing calving events and promoting crevassing and fluctuating water contents at the glacier margin. We suggest that hydro-fracturing was the dominant mechanism responsible for generating more crevasses each year, which facilitated the development of an efficient englacial drainage system. This fed increasing quantities of water to the bed, where it was stored in subglacial cavities and transferred through a distributed (‘slow') drainage system. However, despite this increase in subglacial water content, ice velocities remained constant during the break-up. Comparisons are made between the processes observed at Briksdalsbreen and those associated with the acceleration and rapid retreat of Greenland's tidewater glaciers.
A refined chronology for the Cambrian succession of southern Britain
Authors: Harvey Thomas H.P. , Williams Mark , Condon Daniel J. , Wilby Philip R. , Siveter David J. , Rushton Adrian W.A. , Leng Melanie J. , Gabbott Sarah E.
Published: April 2011

Three dated (U–Pb, zircon) ash beds from biostratigraphically constrained Avalonian successions of Shropshire (England) and Pembrokeshire (Wales) delimit the traditional ‘Lower'–‘Middle' Cambrian boundary and resolve a problematic regional correlation. In Shropshire, a date of 514.45 ± 0.36 [0.81 including tracer calibration and
238
U decay constant errors] Ma from near the top of the Lower Comley Sandstone Formation provides a maximum age for the boundary between Cambrian Stages 3 and 4, and a date of 509.10 ± 0.22 [0.77 including tracer calibration and
238
U decay constant errors] Ma from the basal Quarry Ridge Grits, Upper Comley Sandstone Formation, provides a minimum age for the boundary between Cambrian Stages 4 and 5 (and thus Series 2 and 3). These dates offer a calibration of early metazoan evolution by directly constraining the age of the intervening Comley Limestones, which contain diverse small shelly fossils in addition to trilobites, and also a key early occurrence of exceptional, three-dimensionally preserved arthropods. In Pembrokeshire, an ash bed from the Caerfai Bay Shales Formation dates to 519.30 ± 0.23 [0.77 including tracer calibration and
238
U decay constant errors] Ma, equivalent to a horizon low in the Lower Comley Sandstone Formation of Shropshire, possibly around the level at which trilobites make their first local appearance.

Supplementary material:

Appendix 1, a table of isotope data, is available at
http://www.geolsoc.org.uk/SUP18444
.
Geochemistry and U–Pb dating of felsic volcanic rocks in the Riotinto–Nerva unit, Iberian Pyrite Belt, Spain: crustal thinning, progressive crustal melting and massive sulphide genesis
Authors: Valenzuela Alfonso , Donaire Teodosio , Pin Christian , Toscano Manuel , Hamilton Michael A. , Pascual Emilio
Published: April 2011

We present new geochemical, Sm–Nd and U–Pb data on the felsic volcanic rocks containing the world-class volcanic-hosted massive sulphide deposits in the Riotinto–Nerva unit, Iberian Pyrite Belt, Spain. Three new U–Pb ages from older plagioclase–quartz-phyric dacites and plagioclase-phyric rhyolites to youngest plagioclase–quartz-phyric rhyolites indicate a time span for felsic volcanism ranging from 351.5 ± 0.4 to 345.7 ± 0.6 Ma. The youngest felsic rocks exhibit lower ε
Nd
, as well as contrasting Ti, Sr, Zr, Hf and Eu/Eu* values. We interpret that in the Riotinto–Nerva unit crustal melting successively affected shallower, more evolved horizons in the crust. Progressive crustal melting is consistent with current interpretations of the Iberian Pyrite Belt in terms of a late Devonian–Early Carboniferous transtensional setting, coupled with underplating by basic magma. We suggest that low ε
Nd
, evolved crustal magmatism could be used as a proxy in studies of the genesis of these and possibly other Phanerozoic massive sulphide deposits.

Supplementary material:

Details of the analytical methods and whole-rock data for basalts are available at
http://www.geolsoc.org.uk/SUP18452
.
Submarine slope degradation and aggradation and the stratigraphic evolution of channel–levee systems
Authors: Hodgson D.M. , Di Celma C.N. , Brunt R.L. , Flint S.S.
Published: April 2011

Two seismic-scale submarine channel–levee systems exposed in the Karoo Basin, South Africa provide insights into slope conduit evolution. Component channel fills in a levee-confined channel system (Unit C) and an entrenched channel system (Unit D) follow common stacking patterns; initial horizontal stacking (lateral migration) is followed by vertical stacking (aggradation). This architecture is a response to an equilibrium profile shift from low accommodation (slope degradation, composite erosion surface formation, external levee development, sediment bypass) through at-grade conditions (horizontal stacking and widening) to high accommodation (slope aggradation, vertical stacking, internal levee development). This architecture is likely common to other channel–levee systems.

Supplementary material:

A detailed correlation panel (presented schematically in Figure
2
) is available at
www.geolsoc.org.uk/SUP18456
.
The significance of hiatal surfaces in coal seams
Authors: Jerrett R.M. , Davies R.C. , Hodgson D.M. , Flint S.S. , Chiverrell R.C.
Published: April 2011

A widespread misconception is that coals correspond to single palaeo-peat bodies, which represent continuous and time-invariant records of peat accumulation. Evidence for the occurrence of intra-seam hiatal surfaces within datasets from bituminous coals, lignites and modern peats suggests that existing depositional models for peat and coal require modification. Recognition that coals may represent a succession of stacked mires separated by hiatal surfaces has implications for palaeoenvironmental and sequence stratigraphic studies that assume a continuous record of peat accumulation, as well as for the prediction of whole-seam composition and thickness trends.
Fundamentals of III-V Semiconductor Electrochemistry and Wet Etching Processes: Br2 Etching Properties onto InP
Authors: Causier Alexandre , Gérard Isabelle , Bouttemy Muriel , Tran-Van Pierre , Etcheberry Arnaud
Published: April 2011

Etching mechanism, of HBr/Br2 solutions on InP, is studied using approaches as electrochemical characterization XPS analyses, Indium dosage by GF-AAS, SEM analysis of cross sectional shapes of etching features. As on GaAs we observed the characteristic opposition toward the dark reduction of Br2 for n&p InP. The electrochemistry supports a description of the etching similar to the GaAs one, supposing a "chemical model" governs the process. Nevertheless XPS analyses of surface after etching shows that the etching implies oxidation processes that can only considered as resulting from the etching mechanism. So side oxidation process including hole injection contribution in the Br2 reduction can be proposed opening a new element for discussion of the model that describe the etching properties of halogen oxidizing species as Br2
Controlled Formation of ZnO Fine-Pattern Transparent Electrodes by Wet-Chemical Etching
Authors: Yamamoto Naoki , Makino Hisao , Sato Yasushi , Yamamoto Tetsuya
Published: April 2011

Quality control of the chemicals used to form patterns in GZO films is very important when producing fine patterns. For example, using a TMAH (tetramethylammonium hydroxide) aqueous solution as a developer for a positive-type photoresist, precise control of its pH value in the range from 12.0 to 13.2 is essential when forming fine, dense patterns of lines and spaces a few micrometers wide in GZO films. A zinc-oxy-carbonate passivation layer was formed on the surface of GZO films by reaction with carbon dioxide absorbed from the atmosphere into the acid etchant. The passivation layer assisted the formation of a 2-μm-wide fine pattern because it reduced the etching rate of GZO in the acidic etchant
Microwave Electrochemical Characterization of the Si/Isolator Interface
Authors: Martinez Moreno Elias , Kunst Marinus
Published: April 2011

In the present work measurements, combining classic impedance potentiostatic methods with conductance measurements in the microwave frequency range, are applied to semiconductor/insulator heterojunctions in an electrochemical cell configuration. The Si/a-SiNx:H interface has been studied by these methods in different electronic regimes. Quasi-stationary and transient photo-conductance experiments in combination with photocurrent measurements have been described as function of the applied potential. Moreover, potential modulated conductance measurements in combination with impedance measurements have been performed to identify flatband and so the space charge regimes of this heterojunction. Leading to the conclusion that the fixed charge in a-SiNx:H is responsible for the Si wafer passivation but it is shown that the electronic configuration of this interface present certain instabilities.
Influence of Residual Ions and Gases at Si/SiO2 Interface in Ultra-Thin Gate Oxide
Authors: Chen Tzu-Yu , Lu Han-Wei , Hwu Jenn-Gwo
Published: April 2011

The influence of residual ions and gases at the Si/SiO2 interface in metal-oxide-semiconductor (MOS) structure was investigated in this study. A new processing step, room temperature (RT) vacuum treatment, was proposed to discuss the influence of them on the characteristics of the interface. Treatment sample was placed under low nitrogen pressure at room temperature after oxidation but before post-oxidation annealing (POA). It was found that the oxide layer becomes thinner, flat-band voltage (VFB) shifts to positive, much interface trap density (Dit), and less oxide charges effect in inversion region for the sample with the treatment.
Nanobonding for Multi-Junction Solar Cells at Room Temperature
Authors: Yu Tian , Howlader Matiar R. , Zhang Fangfang , Bakr Mohamed
Published: April 2011

Direct nanobonding of p-Si/n-GaAs wafers based on surface activation that uses an Argon (Ar)-fast atom beam at room temperature has been investigated. The bonding strength of the interface was 14.4 MPa at room temperature, and remained nearly constant after annealing up to 600 °C. An amorphous layer with a thickness of 11.5 nm was found across the interface without annealing. After annealing, the electrical current-voltage (I-V) characteristics were improved and the amorphous layer was diminished across the interface. The thermal stability of the interfacial properties of Si/GaAs indicates its potential use on the fabrication of multi-junction solar cells with Si substrate to lower the cost while improving the solar cells' efficiency. The thickness dependence of p-Si/n-Si interfacial I-V characteristics using COMSOL simulation indicates the decrease of breakdown voltage and current with the increase of the junction thickness.
Green Laser Crystallization of GeSi Thin Films and Dopant Activation
Authors: Rangarajan Balaji , Brunets Ihor , Oesterlin Peter , Kovalgin Alexey Y. , Schmitz Jurriaan
Published: April 2011

Laser-crystallization of amorphous Ge(0.85)Si(0.15) films is studied, using green laser scanning and preformed topography to steer the crystallization. Large crystals (8x2 µm^2) are formed with location-controlled grain boundaries. The obtained films were characterized using Scanning Electron Microscopy, Transmission Electron Microscopy, Atomic Force Microscopy, X-Ray Photoelectron spectroscopy, X-Ray Diffraction and Spectroscopic Ellipsometry. In addition, the activation of ion-implanted poly-Ge(0.85)Si(0.15) films is compared after furnace annealing, rapid thermal annealing and green-laser annealing.
Germanium Fin Structure Optimization for Future MugFET and FinFET Applications
Authors: Shayesteh Maryam , Duffy Ray , McCarthy Brendan , Blake Alan , White Mary , Scully Jim , Yu Ran , Djara Vladimir , Schmidt Michael , Petkov Nikolay , Kelleher Anne-Marie
Published: April 2011

(100) germanium wafers were patterned by e-beam lithography with various exposure doses, in combination with dry etch, resulting in fin structures with widths in the range of approximately 20-150 nm with a high aspect ratio, running in either the [100] or [110] direction. Fins were also subjected to various anneals in N2 to examine germanium desorption but little or no size reduction was observed for realistic thermal budgets. Other samples received a phosphorus implant (at 7°) that partially amorphized the structures. The amorphous depth was 120 nm. Subsequently a 400 °C 3 min furnace anneal in N2 recrystallized the wide fins completely, leading to the formation of various defects, including twin boundaries, small localized defects, and stacking faults. Recrystallization was retarded in narrow fins as was reported in silicon fins.
(Keynote) Progress, Opportunities and Challenges for Beyond CMOS Information Processing Technologies
Authors: Bourianoff George , Nikonov Dmitri
Published: April 2011

During the past 10 years, a great deal of worldwide research has been directed towards exploring "beyond CMOS" information processing technologies. In the US, much of that work has been focused within the Nanoelectronics Research Initiative (NRI) formed in 2005. This presentation will not summarize the research results that have come out of that effort but will draw some conclusions from that work to form some projections about future research directions.
(Invited) Single-Digit Nanofabrication Routes for Tailoring and Assembling Graphene into Functional Nanostructures and Devices
Authors: Liang Xiaogan , Olynick Deirdre L. , Cabrini Stefano , Bokor Jeffrey
Published: April 2011

We present an integrative methodology for creating orderly arranged graphene nanostructures with critical dimensions within sub-10 nm regime. The whole methodology consists of several techniques previously developed and reported by our group. Here we present a more systematic and complementary discussion and overview of these technical steps. The technology and prototype devices presented here may serve as an important basis for future graphene-based electronics.
Stress Characterization of Tungsten-Filled Through Silicon via Arrays Using Very High Resolution Multi-Wavelength Raman Spectroscopy
Authors: Gambino Jeff , Vanslette Daniel , Webb Bucknell , Luce Cameron , Ueda Takeshi , Ishigaki Toshikazu , Kang Kitaek , Yoo Woo Sik
Published: April 2011

Stress in Si adjacent to W-filled TSVs has been measured by multiwavelength Raman spectroscopy (probe depth ranging from 290 to 645 nm) and compared to finite element modeling. The stress in Si from the TSVs increases with TSV width and is almost constant at the different depths probed in this study. The Raman signal is mainly due to the sum of the Sx and Sy stress components, perpendicular and parallel to the TSV bars. The Sx component is tensile and the Sy component is compressive, with the Sy component dominant in between the TSVs. However, ~10 um from the edge of the TSV array, the two components are equal in magnitude so that the stress measured by Raman is zero, even though the individual Sx and Sy stresses are considerable. Hence, it is important to use finite element modeling in conjunction with Raman spectroscopy to characterize stresses in TSVs.
Comparison of Boron Diffusion in Silicon during the Formation of Shallow p+/n Junction with KrF and Green Laser Annealing
Authors: Aid Siti Rahmah , Matsumoto Satoru , Fuse Genshu , Sakuragi Susumu
Published: April 2011

A combination of Ge pre-amorphization implantation (Ge-PAI), low-energy B implantation and non-melt laser annealing is a promising method to form highly-activated, abrupt and ultra-shallow junctions (USJ). In this work, shallow p+/n junction was formed by annealing the implanted sample with two different laser sources, i.e. by using excimer laser, KrF (λ= 248nm, pulse duration : 37ns) and green laser (λ= 527nm, pulse duration : 110ns) in order to compare the diffusion of boron during the formation of shallow p+/n junction. Experimental results show that remarkable boron diffusion occurred during annealing of the samples subjected to KrF laser annealing with a very short annealing time. Meanwhile, boron diffusion is controlled in the samples subjected to green laser annealing. We considered that the penetration depth and the pulse duration are the important factor that may caused the difference in boron diffusion during annealing process.
(Invited) Recent Developments in Ion Implantation
Authors: Renau Anthony
Published: April 2011

The last few years have seen significant developments in ion implantation: Commercial implanters are now available with cryogenic capabilities to enable significant reductions in implant induced crystal damage; Plasma doping tools are now extensively used in fabs; Modified sources and new chemistries have been developed that allow some implants to be replaced by more exotic molecular implants to enable simultaneous co-implants and minimize end of range damage; Today's implanters give better dopant placement performance than ever before. These changes have been driven by CMOS scaling challenges, particularly at 32nm and 22nm, along with changes in thermal processing and the emergence of new implant applications. Details of some of these developments are given along with some explanation of the changes that have made them necessary.
Problems of N-type Doped Regions in Germanium, their Solutions, and How to Beat the ITRS Roadmap
Authors: Duffy Ray , Shayesteh Maryam , White Mary , Kearney John , Kelleher Anne-Marie
Published: April 2011

In this paper the authors discuss the issues surrounding the formation of ultrashallow n-type junctions in Ge. In general the n-type dopants are relatively difficult to activate and diffuse quickly, leading to high access resistances and limited capability to reduce the device dimensions, respectively. Sheet resistance (Rs) was calculated for n-type box-like profiles in Si and Ge. To achieve ITRS Roadmap targets in Si an active doping concentration of 1.5-2×1020 cm-3 is required, but due to the enhanced electron mobility it is predicted approximately 6×1019 cm-3 is sufficient in Ge.
Effect of HfO2 Crystallinity on Device Characteristics and Reliability for ReRAM
Authors: Kim Ja-Yong , Joo M. S. , Yoo J. H. , Youn T. O. , Kim S. J. , Kim W. G. , Kim J.N. , Roh J. S. , Park S. K.
Published: April 2011

It has been investigated HfO2 crystallinity depending on the crystallinity of under layer electrode material and its effect on device characteristics and reliability for ReRAM. HfO2 on TiN electrode, which has a polycrystalline structure, shows the degradation of resistive switching characteristics possibly due to the local crystallization of HfO2 on the crystallized TiN. On the contrary, HfO2 on TiAlN electrode, which has an amorphous structure, shows the excellent switching and endurance characteristics owing to control the crystallization of HfO2.
Pr3Si6N11/Si3N4 Stacked High-k Gate Dielectrics with High Quality Ultrathin Si3N4 Interfacial Layers
Authors: Ohmi Tadahiro , Wakamatsu Hidetoshi , Teramoto Akinobu
Published: April 2011

In Order to utilize the entire capability of the silicon crystal, we must fabricate LSI on any crystal orientation silicon surface using three dimensional structure MOS transistors, i.e., very high integrity gate insulator films must be formed on any crystal orientation silicon surface with the same formation speed, i.e., the radical oxidation (SiO2) and the radical nitridation (Si3N4) at low temperatures. Accumulation mode balanced CMOS fabricated on (551) surface silicon SOI substrate has been theoretically confirmed to exhibit super high speed performance over 100 GHz clock rate at 45 nm technology node where the gate insulator film to silicon interface is atomically flat and the series resistance of the source and the drain electrode is decreased by a factor of two orders of magnitude by introducing very low contact resistance new silicide materials to n+ region (ErSi2) and p+ region (Pr2Si), respectively.
Fabrication and Electrical Characterization of High-k LaGdO3 Thin Films and Field Effect Transistors
Authors: Pavunny Shojan P. , Thomas R. , Kalkur T.S. , Schubert Jurgen , Fachini E. , Katiyar Ram S.
Published: April 2011

The electrical properties of LaGdO3 (LGO) high-k dielectric thin films prepared by pulsed laser deposition (PLD) on SiOx/p-Si substrate have been studied. The equivalent oxide thickness (EOT) and gate leakage current density (Jg) were determined on metal-oxide-semiconductor (MOS) structures. Capacitance-Voltage characteristics showed negligible hysteresis, ~8 mV. The extracted dielectric constant (k) of LGO layer from the EOT-physical thickness plot was ~21.6 ± 1.7. LGO layers with EOT of 3nm had a Jg ~ 3 x 10-8 A/cm2 at accumulation (Vg=VFB-1). The estimated interfacial trap density at the flatband voltage as determined by Lehovec method was in the range 1012 eV-1cm-2. N-channel LGO metal-oxide-semiconductor field effect transistors (MOSFET) have been fabricated and electrically characterized. The threshold voltage (Vt) was ~0.3V.
Effects of Metal Layer Insertion on EOT Scaling in TiN/Metal/La2O3/Si High-k Gate Stacks
Authors: Ahmet Parhat , Kitayama Daisuke , Kaneda Tasuku , Suzuki Takuya , Koyanagi Tomotsune , Kouda Miyuki , Mamatrishat Maimaiti , Kawanago Takamasa , Kakushima Kuniyuki , Tsutsui Kazuo , Nishiyama Akira , Sugii Nobuyuki , Natori Kenji , Hattori Takeo , Iwai Hiroshi
Published: April 2011

Effects of a thin metal layer (W, Ta, or Mo) inserted at the interface between La2O3 high-k gate dielectric and TiN gate metal were studied. It was found that the inserted metal layer plays crucial role in determining the electrical characteristics of the TiN/Metal/La2O3/Si gate stack. Our results show that EOT can be scaled to 0.5nm and below by inserting a W layer with optimum thickness at the interface between La2O3 high-k gate dielectric and the TiN gate metal.
Improvement on Electrical Characteristics of HfO2 MIS Capacitor with Dual Plasma Treatment
Authors: Chang Kow-Ming , Chang Ting-Chia , Chen Hshu-Wei
Published: April 2011

There have been some researches described that nitridation processes could improve thermal stability and dielectric constant of Hf-based dielectrics. The improvement of electrical characteristics of HfO2 thin films with plasma nitridation has been examined. Moreover, CF4 plasma treatment on HfO2 thin films in order to suppress leakage current and passivate defect were also proposed. In this study, we proposed to combine two kinds of plasma treatment, CF4 pre-treatment and nitrogen post-treatment, in order to have further improvement on electrical characteristics. The capacitance-voltage (C-V) characteristics, current-voltage (J-V) characteristics, and hysteresis of the samples were preformed to estimate the improvement effect. According to this study, dual plasma treatment would be an effective technology to improve the electrical characteristic and the hysteresis of pure HfO2 thin films.