bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of shear wall structures of variable cross section
Authors: Wdowicki Jacek , Wdowicka Elżbieta
Published: March 2010

A method has been proposed for the analysis of three‐dimensional shear wall and shear core assemblies having stepwise changes in the cross section. The analysis is based on a variant of the continuous connection method. In the continuous approach, the connecting beams are replaced by equivalent continuous connections. The differential equation systems for shear wall structure segments of constant cross section are uncoupled by orthogonal eigenvectors. The solution matches the boundary conditions of the upper and lower parts of the wall at the plane of contiguity, at which an abrupt change in cross section occurs. This yields a system of linear equations, which enable the determination of the integration constants. The correctness and efficiency of the proposed method are illustrated by its application to the analysis of plane and three‐dimensional shear wall systems of variable cross section. Copyright © 2010 John Wiley & Sons, Ltd.
Seismic evaluation of a 56‐storey residential reinforced concrete high‐rise building based on nonlinear dynamic time‐history analyses
Authors: Epackachi Siamak , Mirghaderi Rasoul , Esmaili Omid , Behbahani Ali Asghar Taheri , Vahdani Shahram
Published: March 2010

In recent decades, shear walls and tube structures have been the most appropriate structural forms for the construction of high‐rise concrete buildings. Thus, recent Reinforced Concrete (RC) tall buildings have more complicated structural behaviour than before. Therefore, studying the structural systems and associated behaviour of these types of structures is very important. The main objective of this paper is to study the linear and nonlinear behaviour of one of the tallest RC buildings, a 56‐storey structure, located in a high seismic zone in Iran. In this tower, shear wall systems with irregular openings are utilized under both gravity and lateral loads and may result in some especial issues in the behaviour of structural elements such as shear walls and coupling beams. The analytical methodologies and the results obtained in the evaluation of life‐safety and collapse prevention of the building are also discussed. The weak zones of the structure based on the results are introduced, and a detailed discussion of some important structural aspects of the high‐rise shear wall system with consideration of the concrete time dependency and constructional sequence effects is also included. Copyright © 2010 John Wiley & Sons, Ltd.
Mechanical behaviours and engineering application of steel truss reinforced concrete transfer beam in tall buildings
Authors: Wu Yi , Cai Jian , Yang Chun , Zhou Yun , Zhang Chunmei
Published: March 2010

A new type of steel reinforced concrete (SRC) transfer beam, the steel truss reinforced concrete (STRC) transfer beam, is developed and applied to a 100 m tall building in Guangzhou City to solve the difficulty of two built subways being buried under the building. Experimental studies on mechanical behaviours of STRC composite transfer beams were carried out, and the structural characteristics and economic characters of the transfer beam were introduced. Experimental investigations verify that the STRC transfer beam is of high limit bearing capacity, large rigidity and good ductility. Compared with normal reinforced concrete transfer beam, the limit bearing capacity of the STRC transfer beam can be enhanced 30–40%, and the rigidity can be improved 30–50%. In the STRC transfer beam, the strut‐and‐tie force transference mode is followed, the loads are mainly transferred by compressive diagonal SRC struts from the loading point and abutments, SRC struts and horizontal ties form a self‐balance system. The cost of material, fireproof and construction can be saved; more space for commercial function and convenient construction can be achieved by adopting STRC transfer beams. Copyright © 2010 John Wiley & Sons, Ltd.
Evaluating the ductility and shear behaviour of carbon fibre reinforced polymer and glass fibre reinforced polymer reinforced concrete columns
Authors: Barghi Mostafa , Azadbakht Mohsen , Hadad Meysam
Published: March 2010

Brittle shear failure in short reinforced concrete (RC) columns has been identified as one of the most dangerous failure modes that may cause collapse of bridges, based on research findings and damage reconnaissance of past earthquakes. Using ABAQUS software, the effect of carbon fibre reinforced polymer (CFRP) and glass fibre reinforced polymer (GFRP) on retrofitting of existing circular RC columns, and also enhancing of shear strength have been studied. Five types of concrete columns were studied in the ‘as built’ condition to investigate the shear failure mode of columns. These columns were assessed again after being retrofitted by using CFRP and GFRP. Based on findings of this research, the effect of CFRP jackets on improving the shear behaviour of column is more than that of GFRP jackets, while GFRP jackets are more effective than CFRP jackets, regarding their contribution in increasing the column ductility. Therefore, these FRP composites can be utilized in different conditions, according to column demand for increasing the ductility or shear strength. Copyright © 2010 John Wiley & Sons, Ltd.
Competing risks
Authors: Klein John P.
Published: March 2010

Competing risks arise when a subject is exposed to many causes of failure. Data consist of the time the subject failed and an indicator of which risk caused the subject to fail. Examples in medicine include the analysis of cause to death data, the analysis of relapse and death in remission in cancer studies, or random right censoring. In engineering applications competing risks arise when analyzing series systems. Classical competing risks deal with the modeling of the probability of failure in the observed system (crude probabilities) or in systems with some causes of failure removed (net or partial crude probabilities). Modern competing risks theory, often based on counting process methodology, examines estimation techniques for competing risks probabilities, regression modeling for competing risks probabilities and comparing competing risks probabilities between treatment groups. Copyright © 2010 John Wiley & Sons, Inc.

This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Reliability, Survivability, and Quality Control
A Novel Metal–Ligand Iodo‐bridged Lead(II) Compound: Synthesis, Crystal Structure, Thermal Properties, and DFT Calculations of [Pb(dmp)I2]n
Authors: Shaabani Behrouz , Mirtamizdoust Babak , Viterbo Davide , Croce Gianluca , Hammud Hassan
Published: March 2010

. A novel 1D PbII coordination polymer [Pb(dmp)I2]n (1) (dmp = 2,9‐dimethyl‐1,10‐phenanthroline) containing a Pb2‐(μ‐I)2 unit was synthesized and characterized by elemental analysis, IR, 1H NMR, and 13C NMR spectroscopy and studied by thermal analysis as well as X‐ray crystallography. The single‐crystal X‐ray data show that the coordination number of PbII ions is six, i.e. PbN2I4, with “stereo‐chemically active” electron lone pairs, and the coordination sphere is asymmetrical. They also show that the chains interact with each other through π‐π stacking interactions, which create a 3D framework. The structure of the title complex has been optimized by density functional theory calculations. The calculated structural parameters and the IR spectra of the title complex are in agreement with the crystal structure.
Synthesis, Crystal Structure and Optical Properties of LaNbON2
Authors: Logvinovich Dmitry , Ebbinghaus Stefan G. , Reller Armin , Marozau Ivan , Ferri Davide , Weidenkaff Anke
Published: March 2010

LaNbON2 was synthesized by thermal ammonolysis of crystalline LaNbO4 prepared by a soft chemistry approach. LaNbON2 crystallizes in a distorted GdFeO3‐like perovskite structure with space group Pnma and a = 5.5720(2), b = 7.8656(4), c = 5.6066(3) Å and a random anionic arrangement as revealed by neutron diffraction. Elongated displacement ellipsoids found by neutron diffraction and a considerable degree of residual bond strain as revealed by the bond valence calculations suggest a local positional disorder of the niobium ions.The material exhibits good chemical stability at ambient conditions and a considerable thermal stability upon heating in synthetic air (up to T = 500 K) as well as a small optical band gap of ~1.7 eV.
Efficacy of recombinant human α‐L‐iduronidase (laronidase) on restricted range of motion of upper extremities in mucopolysaccharidosis type I patients
Authors: Tylki‐Szymanska Anna , Marucha Jolanta , Jurecka Agnieszka , Syczewska Malgorzata , Czartoryska Barbara
Published: March 2010

The aims of the study were to assess the effectiveness of enzyme replacement therapy (ERT) with laronidase on the range of motion (ROM) of upper extremities and influence on activities of daily living (ADLs) of patients with mucopolysaccharidosis type I (MPS I). The ROM of 17 patients with MPS I was followed from the first year of life until the introduction of ERT and after 52–208 weeks of treatment. In all patients (group 1, n = 10), passive ROM was assessed. In patients with Hurler/Scheie or Scheie phenotype (group 2, n = 7) both passive and active ROM, as well as daily life activities, were evaluated. Passive and active ROM was measured by a goniometer, while a health assessment questionnaire was used to assess activities of daily living. The data since the first months of life until the beginning of treatment were obtained by retrospective review of patients’ charts. Restriction in ROM of the upper extremities of patients with MPS I was observed from the first year of life. These limitations intensified and became more severe with the patients’ age, making patients’ self‐care more difficult or even impossible. Introduction of ERT led to slower progression of symptoms, especially in the passive range of motion in all patients. Additionally, patients with normal mental development, or only slightly delayed (group 2), who underwent active physical rehabilitation (including mobilisation of nerve system, passive techniques for joint mobility, active gymnastics for muscle power, as well as massage and the training of families for therapy at home) showed improvement in active movement followed by enhanced self‐care.
A One-Day Frequency-Volume Chart is Representative of a 3-Day Chart in the Assessment of Lower Urinary Tract Symptoms Suggestive of Bladder Outflow Obstruction
Authors: Rajan Prabhakar , Turner Kevin J. , Mariappan Paramananthan , Stewart Laurence H.
Published: March 2010

Introduction:

24-h frequency-volume (FV) charts are often used to assess patients with lower urinary tract symptoms suggestive of bladder outflow obstruction (LUTS/BOO). There are no clear guidelines regarding the optimum chart duration. We aimed to determine whether a one-day FV chart is representative of a 3-day equivalent.

Patients and methods:

Men presenting with LUTS (including nocturia) were prospectively recruited and completed a 3-day FV chart. Exclusion criteria were previous bladder outflow surgery and anti-cholinergic medication.

Results:

285 patients were recruited (mean age, 67 years; range 26–93 years). There were no significant inter-day differences in 24-h urine volume (24HUV) ( p = 0.10) and functional bladder capacity (FBC) ( p = 0.19). However, there were significant differences identified between days 1 and 2, and 1 and 3 for both nocturnal urine volume (NUV) ( p < 0.001) and actual nocturnal voids (ANV) ( p < 0.001) despite significant correlation of these parameters on each day with their respective 3-day means.

Conclusion:

Our data suggest that a one-day FV chart is representative of a 3-day equivalent for the assessment of 24HUV and FBC in patients with LUTS/BOO. Further studies are required to compare the repeatability and clinical utility of a one-day chart compared with 3- and 7-day charts, particularly in patients with nocturia.
The association between supra‐physiological levels of estradiol and response patterns to experimental pain
Authors: Nisenblat Vicki , Engel‐Yeger Batya , Ohel Gonen , Aronson Doron , Granot Michal
Published: March 2010

The precise mechanism by which gonadal hormones influence pain perception is still obscure. However, no studies have examined experimental pain responses at supra‐physiological hormone levels. This study explored the influence of pharmacological estradiol (E2) levels on the stability of pain perception obtained via quantitative sensory testing. A repeated measures design was used with 31 women, treated by a same In Vitro Fertilization (IVF) protocol. Patterns of experimental pain response were assessed in three different sessions (baseline, down regulation, maximal ovarian stimulation). Correlations between hormonal levels (E2, progesterone, luteinizing hormone (LH)) and pain perceptions were assessed at each session. While in the entire sample the pattern of response to pain stimulations remained unchanged regardless of hormonal manipulations, a greater pain sensitivity was associated with supra‐physiological levels of E2 during the maximal ovarian stimulation session (for 47 °C stimulation: r = .383, p = 0.044). Mixed model repeated measures ANOVA indicated that participants who over‐responded to the ovarian stimulation session (E2 > 10,500 pmol/l) showed significant enhanced pain responses under this condition (p = 0.004). No correlations between progesterone, LH and experimental pain perception were found in any of the study sessions. Although pain perceptions at different E2 levels remained constant, the enhancement of pain scoring at supra‐physiological E2 levels, underscore the possible role of sex hormones in pain modulation and experience.
A Review of Electronic Laboratory Notebooks Available in the Market Today
Authors: Rubacha Michael , Rattan Anil K. , Hosselet Stephen C.
Published: March 2010

Electronic laboratory notebooks are becoming an increasingly popular tool for research and routine laboratories as part of a way to optimize workflow and minimize cost while realizing time-saving benefits. The number and variety of available solutions are quickly increasing; making selection of the right notebook a cumbersome process. To allay some of the strain associated with an exhaustive search through notebook technologies, this paper details some key features from a pool of 35 electronic notebooks available today. This review effectively classifies these notebooks into five categories based on market audience as follows: notebooks suited for a Quality environment can be found within the Quality Assurance/Quality Control pool. Notebooks suited for specialized tasks in Biology or Chemistry can be found within the Biology or Chemistry pools, respectively. Notebooks that are suitable for general science functionalities can be found under either the Research and Development or the Multidiscipline pools. Lastly, notebooks that are designed and developed for the spectrum of stringent Quality laboratories to free-form research laboratories can be found within the Multidiscipline pool. The guidelines put forth in this paper eliminate the need to perform an exhaustive search for a suitable notebook.
An Innovative Way to Create Assay Ready Plates for Concentration Response Testing using Acoustic Technology
Authors: Turmel Manori , Itkin Zina , Liu Don , Nie Dalin
Published: March 2010

A totally integrated serial dilution assay plate preparation system that fully uses the high precision nanoliter dispensing capabilities of acoustic liquid handlers has been developed and implemented. The application uses a hybrid of a serial dilution method and a direct dilution method, achieving a wide concentration range for the dilution series, while avoiding additive errors inherent to traditional serial dilution methods. The method allows assay miniaturization, which greatly reduces reagent and consumable costs to the customers. The system is in production at AstraZeneca and has generated high-quality assay ready plates for high-throughput screening and secondary screening since 2005. Further development in recent years has expanded the flexibility of the assay ready plate creation process to meet varied screening requirements.

We will discuss the requirements for assay ready plates for concentration response testing and describe the novel plate creation method in detail with the rigorous validation procedures. Along with method validation data, some real-life screening results will be presented to compare an experiment conducted on compounds prepared using the novel hybrid method and those prepared using a more traditional serial dilution method, which endorses the application of the novel method.
Gut microbiota composition is associated with body weight, weight gain and biochemical parameters in pregnant women
Authors: Santacruz A. , Collado M. C. , García-Valdés L. , Segura M. T. , Martín-Lagos J. A. , Anjos T. , Martí-Romero M. , Lopez R. M. , Florido J. , Campoy C. , Sanz Y.
Published: March 2010

Obesity is associated with complications during pregnancy and increased health risks in the newborn. The objective of the present study was to establish possible relationships between gut microbiota, body weight, weight gain and biochemical parameters in pregnant women. Fifty pregnant women were classified according to their BMI in normal-weight (n34) and overweight (n16) groups. Gut microbiota composition was analysed by quantitative real-time PCR in faeces and biochemical parameters in plasma at 24 weeks of pregnancy. Reduced numbers ofBifidobacteriumandBacteroidesand increased numbers ofStaphylococcus,EnterobacteriaceaeandEscherichia coliwere detected in overweight compared with normal-weight pregnant women.E. colinumbers were higher in women with excessive weight gain than in women with normal weight gain during pregnancy, whileBifidobacteriumandAkkermansia muciniphilashowed an opposite trend. In the whole population, increased total bacteria andStaphylococcusnumbers were related to increased plasma cholesterol levels. IncreasedBacteroidesnumbers were related to increased HDL-cholesterol and folic acid levels, and reduced TAG levels. IncreasedBifidobacteriumnumbers were related to increased folic acid levels. IncreasedEnterobacteriaceaeandE. colinumbers were related to increased ferritin and reduced transferrin, whileBifidobacteriumlevels showed the opposite trend. Therefore, gut microbiota composition is related to body weight, weight gain and metabolic biomarkers during pregnancy, which might be of relevance to the management of the health of women and infants.
Daidzein-metabolising phenotypes in relation to serum lipids and uric acid in adults in Guangzhou, China
Authors: Guo Kaiping , Zhang Bo , Chen Chaogang , Uchiyama Shigeto , Ueno Tomomi , Chen Yuming , Su Yixiang
Published: March 2010

Previous studies have suggested that daidzein's metabolites, equol andO-desmethylangolensin (O-DMA), rather than daidzein itself may contribute to the beneficial effects of soya foods in the prevention of CVD. The present study aims to assess the proportion of equol andO-DMA producers, and to compare differences in anthropometric factors, serum lipids, glucose and uric acid between producers and non-producers in Chinese adults aged 20–69 years. For the present cross-sectional study, 202 subjects (100 women and 102 men) were recruited. Twenty-four-hour urinary daidzein and its metabolites were determined in these subjects while on their usual diet and again after a 3-d isoflavone challenge. Fasting serum lipids, glucose and uric acid were examined on their usual diet. Three days of 24 h dietary recalls were used to assess dietary intakes. Of the 202 subjects, 27 (13·4 %) and 27 (13·4 %) excreted equol andO-DMA on their usual diet, and 101 (50 %) and 94 (46·5 %) produced equol andO-DMA after a load of 80 mg/d isoflavones. Equol producers showed lower serum uric acid ( − 10·2 %,P = 0·001), TAG ( − 29·5 %,P = 0·007) and waist:hip ratio ( − 2·6 %,P = 0·032), and tended to have higher HDL cholesterol (6·3 %,P = 0·069) compared with equol non-producers. There were no significant differences in serum lipids, glucose and uric acid betweenO-DMA producers and non-producers. In conclusion, equol phenotypes might influence cardiovascular risk.
Why did Countries Adopt the Gold Standard? Lessons from Japan
Authors: Mitchener Kris James , Shizume Masato , Weidenmier Marc D.
Published: March 2010

Why did policymakers adopt the gold standard? We first examine the political economy of Japan's adoption of the gold standard in 1897 by exploring the ex ante motives of policymakers as well as how the legislative decision to adopt gold won approval. We then show that joining the gold standard did not reduce Japanese interest rates or lead to a domestic investment boom. However, we find that membership in the gold standard increased Japan's exports by lowering transactions costs. Joining gold allowed Japan to tap into its growing share of global trade that was centered on the gold standard.
The Role of Independent Invention in U.S. Technological Development, 1880–1930
Authors: Nicholas Tom
Published: March 2010

Why did independent inventors account for over half of U.S. patents by 1930 and more than three times the number granted to R&D firms? Using new data on patents and historical patent citations, I show that independents supplied high-quality innovations to a geographically broad market for ideas. Those close to large urban centers developed some of the most significant technological advances. Demand for independent inventions remained high during the growth of the corporate economy as firms continued to acquire external innovations that complemented formal R&D. Despite their relative decline, independents remained central to the process of technological development.

“The statement sometimes is made that ‘the day of the genius in the garret is done.’ Nothing could be further from the truth.”

William A. Kinnan, First Assistant Patent Commissioner,New York Times, December 18th, 1927
Testing for the Economic Impact of the U.S. Constitution: Purchasing Power Parity Across the Colonies versus Across the States, 1748–1811
Authors: Grubb Farley
Published: March 2010

The U.S. Constitution removed real and monetary trade barriers between the states. By contrast, these states when they were British colonies exercised considerable real and monetary sovereignty over their borders. Purchasing power parity is used to measure how much economic integration between the states was gained in the decades after the Constitution's adoption compared with what existed among the same locations during the late colonial period. Using this measure, the short-run effect of the Constitution on economic integration was minimal. This may have been because the Constitution did not eliminate all the institutional barriers to interstate trade before 1812.

“No idea is more firmly planted in American history than the idea that one of the most difficult problems during the Confederation was that of barriers to trade between state and state. There had been such barriers in colonial times …”

Merrill Jensen1

“The ‘secret’ of American economic growth, English legal scholar Sir Henry Maine wrote in 1886, lay in ‘the [constitutional] prohibition against levying duties on commodities passing from State to State … . It secures to the producer the command of a free market over an enormous territory of vast natural wealth …’”

Charles W. McCurdy2
The Dynamics of Relief Spending and the Private Urban Labor Market During the New Deal
Authors: Neumann Todd C. , Fishback Price V. , Kantor Shawn
Published: March 2010

We examine the dynamic relationships between relief spending and local private labor markets using a panel data set of relief, private employment, and private earnings. Positive shocks to relief during the First New Deal were followed by increased private employment and earnings, consistent with demand stimulus in that period. On the other hand, increases in work relief spending during the Second New Deal were followed by decreased employment and increased earnings, consistent with crowding out. The timing of spending is consistent with claims that the Roosevelt administration used relief spending to sway elections.
Particle dynamics in a turbulent particle–gas suspension at high Stokes number. Part 1. Velocity and acceleration distributions
Authors: GOSWAMI PARTHA S. , KUMARAN V.
Published: March 2010

The effect of fluid velocity fluctuations on the dynamics of the particles in a turbulent gas–solid suspension is analysed in the low-Reynolds-number and high Stokes number limits, where the particle relaxation time is long compared with the correlation time for the fluid velocity fluctuations, and the drag force on the particles due to the fluid can be expressed by the modified Stokes law. The direct numerical simulation procedure is used for solving the Navier–Stokes equations for the fluid, the particles are modelled as hard spheres which undergo elastic collisions and a one-way coupling algorithm is used where the force exerted by the fluid on the particles is incorporated, but not the reverse force exerted by the particles on the fluid. The particle mean and root-mean-square (RMS) fluctuating velocities, as well as the probability distribution function for the particle velocity fluctuations and the distribution of acceleration of the particles in the central region of the Couette (where the velocity profile is linear and the RMS velocities are nearly constant), are examined. It is found that the distribution of particle velocities is very different from a Gaussian, especially in the spanwise and wall-normal directions. However, the distribution of the acceleration fluctuation on the particles is found to be close to a Gaussian, though the distribution is highly anisotropic and there is a correlation between the fluctuations in the flow and gradient directions. The non-Gaussian nature of the particle velocity fluctuations is found to be due to inter-particle collisions induced by the large particle velocity fluctuations in the flow direction. It is also found that the acceleration distribution on the particles is in very good agreement with the distribution that is calculated from the velocity fluctuations in the fluid, using the Stokes drag law, indicating that there is very little correlation between the fluid velocity fluctuations and the particle velocity fluctuations in the presence of one-way coupling. All of these results indicate that the effect of the turbulent fluid velocity fluctuations can be accurately represented by an anisotropic Gaussian white noise.
Coherent structures in wave boundary layers. Part 2. Solitary motion
Authors: SUMER B. MUTLU , JENSEN PALLE M. , SØRENSEN LONE B. , FREDSØE JØRGEN , LIU PHILIP L.-F. , CARSTENSEN STEFAN
Published: March 2010

This study continues the investigation of wave boundary layers reported by Carstensen, Sumer & Fredsøe (J. Fluid Mech., 2010, part 1 of this paper). The present paper summarizes the results of an experimental investigation of turbulent solitary wave boundary layers, simulated by solitary motion in an oscillating water tunnel. Two kinds of measurements were made: bed shear stress measurements and velocity measurements. The experiments show that the solitary-motion boundary layer experiences three kinds of flow regimes as the Reynolds number is increased: (i) laminar regime; (ii) laminar regime where the boundary-layer flow experiences a regular array of vortex tubes near the bed over a short period of time during the deceleration stage; and (iii) transitional regime characterized with turbulent spots, revealed by single/multiple, or, sometimes, quite dense spikes in the bed shear stress traces. Supplementary synchronized flow visualization tests confirmed the presence of the previously mentioned flow features. Information related to flow resistance are also given in the paper.
Stochastic coherent adaptive large eddy simulation of forced isotropic turbulence
Authors: DE STEFANO G. , VASILYEV O. V.
Published: March 2010

The stochastic coherent adaptive large eddy simulation (SCALES) methodology is a novel approach to the numerical simulation of turbulence, where a dynamic grid adaptation strategy based on wavelet threshold filtering is utilized to solve for the most ‘energetic’ eddies. The effect of the less energetic unresolved motions is simulated by a model. Previous studies have demonstrated excellent predictive properties of the SCALES approach for decaying homogeneous turbulence. In this paper the applicability of the method is further explored for statistically steady turbulent flows by considering linearly forced homogeneous turbulence at moderate Reynolds number. A local dynamic subgrid-scale eddy viscosity model based on the definition of the kinetic energy associated with the unresolved motions is used as closure model. The governing equations for the wavelet filtered velocity field, along with the additional evolution equation for the subgrid-scale kinetic energy, are numerically solved by means of a dynamically adaptive wavelet collocation method. It is demonstrated that adaptive simulations closely match results from a reference pseudo-spectral fully de-aliased direct numerical simulation, by using only about 1% of the corresponding computational nodes. In contrast to classical non-adaptive large eddy simulation, the agreement with direct solution holds for the mean flow statistics as well as in terms of energy and enstrophy spectra up to the dissipative wavenumbers range.
Contact in a viscous fluid. Part 1. A falling wedge
Authors: CAWTHORN C. J. , BALMFORTH N. J.
Published: March 2010

Computations are presented of the upward force on a two-dimensional wedge descending towards a plane surface due to the Stokes flow of an intervening viscous fluid. The predictions are compared with those of lubrication theory and an approximate analytical solution; all three predict a logarithmic divergence of the force with the minimum separation. An object falling vertically under gravity will therefore make contact with an underlying plane surface in finite time if roughened by asperities with sharp corners (with smooth surfaces, contact is made only after infinite time). Contact is still made in finite time if the roughened object also moves horizontally or rotates as it falls.
Contact in a viscous fluid. Part 2. A compressible fluid and an elastic solid
Authors: BALMFORTH N. J. , CAWTHORN C. J. , CRASTER R. V.
Published: March 2010

A lubrication theory is presented for the effect of fluid compressibility and solid elasticity on the descent of a two-dimensional smooth object falling under gravity towards a plane wall through a viscous fluid. The final approach to contact, which takes infinite time in the absence of both effects, is determined by numerical and asymptotic methods. Compressibility can lead to contact in finite time either during inertially generated oscillations or if the viscosity decreases sufficiently quickly with increasing pressure. The approach to contact is invariably slowed by allowing the solids to deform elastically; specific results are presented for an underlying elastic wall modelled as a foundation, half-space, membrane or beam.
Spatial optimal growth in three-dimensional boundary layers
Authors: TEMPELMANN DAVID , HANIFI ARDESHIR , HENNINGSON DAN S.
Published: March 2010

A parabolized set of linear equations is derived, which, in combination with the proposed solution procedure, allows for the study of both non-modal and modal disturbance growth in three-dimensional boundary layers. The method is applicable to disturbance waves whose lines of constant phase are closely aligned with the external streamline. Moreover, strongly growing disturbances may fall outside the scope of application. These equations are used in conjunction with a variational approach to compute optimal disturbances in Falkner–Skan–Cooke boundary layers subject to adverse and favourable pressure gradients. The disturbances associated with maximum energy growth initially take the form of streamwise vortices which are tilted against the mean crossflow shear. While travelling downstream these vortical structures rise into an upright position and evolve into bent streaks. The physical mechanism responsible for non-modal growth in three-dimensional boundary layers is therefore identified as a combination of the lift-up effect and the Orr mechanism. Optimal disturbances smoothly evolve into crossflow modes when entering the supercritical domain of the flow. Non-modal growth is thus found to initiate modal instabilities in three-dimensional boundary layers. Optimal growth is first studied for stationary disturbances. Influences of parameters such as sweep angle, spanwise wavenumber and position of inception are studied, and the initial optimal amplification of stationary crossflow modes because of non-modal growth is investigated. Finally, general disturbances are considered, and envelopes yielding the maximum growth at each position are computed. In general, substantial growth is already found upstream of the first neutral point. The computations show that at supercritical conditions, maximum growth of optimal disturbances in accelerated boundary layers can exceed the growth predicted for modal instabilities by several orders of magnitude.
Two-dimensional flagellar synchronization in viscoelastic fluids
Authors: ELFRING GWYNN J. , PAK ON SHUN , LAUGA ERIC
Published: March 2010

Experimental studies have demonstrated that spermatozoa synchronize their flagella when swimming in close proximity. In a Newtonian fluid, it was shown theoretically that such synchronization arises passively due to hydrodynamic forces between the two swimmers if their waveforms exhibit a front–back geometrical asymmetry. Motivated by the fact that most biological fluids possess a polymeric microstructure, here we address synchronization in a viscoelastic fluid analytically. Using a two-dimensional infinite sheet model, we show that the presence of polymeric stresses removes the geometrical asymmetry constraint and therefore even symmetric swimmers synchronize. Such synchronization occurs on asymptotically faster time scales than in a Newtonian fluid, and the swimmers are seen to be driven into a stable in-phase conformation minimizing the energy dissipated in the surrounding fluid.
Intermittency in the velocity distribution of heavy particles in turbulence
Authors: BEC J. , BIFERALE L. , CENCINI M. , LANOTTE A. S. , TOSCHI F.
Published: March 2010

The statistics of velocity differences between pairs of heavy inertial point particles suspended in an incompressible turbulent flow is studied and found to be extremely intermittent. The problem is particularly relevant to the estimation of the efficiency of collisions among heavy particles in turbulence. We found that when particles are separated by distances within the dissipative subrange, the competition between regions with quiet regular velocity distributions and regions where very close particles have very different velocities (caustics) leads to a quasi bi-fractal behaviour of the particle velocity structure functions. Contrastingly, we show that for particles separated by inertial-range distances, the velocity-difference statistics can be characterized in terms of a local roughness exponent, which is a function of the scale-dependent particle Stokes number only. Results are obtained from high-resolution direct numerical simulations up to 20483 collocation points and with millions of particles for each Stokes number.
Plasma effects in electromagnetic field interaction with biological tissue
Authors: SHARMA R. P. , BATRA KARUNA , EXCELL PETER S.
Published: March 2010

Theoretical analysis is presented of the nonlinear behavior of charge carriers in biological tissue under the influence of varying low-intensity electromagnetic (EM) field. The interaction occurs because of the nonlinear force arising due to the gradient of the EM field intensity acting on free electrons in the conduction band of proteins in metabolically active biological cell membrane receptors leading to a redistribution of charge carriers. Field dependence of the resulting dielectric constant is investigated by a suitable modification to include an additional electronic contribution term to the three-term Debye model. The exogenous EM field propagating in this nonlinear cellular medium satisfies the nonlinear Schrödinger equation and can be affected significantly. Resulting field effect can be substantially augmented and effective rectification/demodulation can occur. Possible implications of this modification on biological processes in white and grey matter are discussed.
Where Science and Magic Meet: The Illusion of a “Science of Magic”
Authors: Lamont Peter , Henderson John M. , Smith Tim J.
Published: March 2010

Recent articles calling for a scientific study of magic have been the subject of widespread interest. This article considers the topic from a broader perspective and argues that to engage in a science of magic, in any meaningful sense, is misguided. It argues that those who have called for a scientific theory of magic have failed to explain either how or why such a theory might be constructed, that a shift of focus to a neuroscience of magic is simply unwarranted, and that a science of magic is itself an inherently unsound idea. It seeks to provide a more informed view of the relationship between science and magic and suggests a more appropriate way forward for scientists.
Two Flavors of Aesthetic Tasting: Rasa and Savoring a Cross-Cultural Study with Implications for Psychology of Emotion
Authors: Sundararajan Louise
Published: March 2010

A comparative analysis suggested that two indigenous theories of aesthetic emotions, the Indian rasa and the Chinese notion of savoring, share in common the two defining characteristics of emotion refinement—detachment and self-reflexivity ( Frijda & Sundararajan, 2007 ), but that these two aesthetic traditions differ in ways that correspond to the ontological/epistemological divide between the ancient Greeks (and other Indo-European languages) and the Chinese as predicted by Nisbett (2003) . Implications of this investigation for theory and research on emotions are discussed.
From Stress to Learning: Attachment Theory Meets Goal Orientation Theory
Authors: Rusk Natalie , Rothbaum Fred
Published: March 2010

Few investigators have explored connections between attachment theory and goal orientation theory. Although the theories differ in important ways, we suggest there is a striking similarity in their depiction of an adaptive pathway leading from stress to learning goals and constructive strategies, and a contrasting pathway leading from stress to self-validation goals and defensive strategies. We review evidence from two leading investigators—Mario Mikulincer in adult attachment theory and Carol Dweck in goal orientation theory—to show that, following failure and other setbacks, learning as compared to self-validation goals are more likely to lead to cognitive openness, problem-solving, support-seeking, and adaptive emotion regulation. The theories differ in their understanding of the views underlying learning and self-validation goals, and those differences have led to qualitatively different interventions. We suggest how attachment and goal orientation theory interventions can be integrated to maximize optimal functioning in stressful conditions.
The Girl-Crisis Movement: Evaluating the Foundation
Authors: Farady Michael
Published: March 2010

Psychologists played a major role behind the widely publicized and popular idea of a crisis among girls. In this paper, several topics basic to the girl-crisis movement are examined. Suggested by the works of psychologists Carol Gilligan and Mary Pipher, the topics are voice, self-esteem, and psychology's role in harming girls. Expected sex differences in voice and self-esteem were not found. The girl-crisis notion that contemporary psychology has colluded in harming girls is at odds with the arc of the profession. The wide divergence between the basic claims of the girl-crisis movement and these findings are discussed. Further critique is recommended.
Gene Terrain: Visual Exploration of Differential Gene Expression Profiles Organized in Native Biomolecular Interaction Networks
Authors: You Qian , Fang Shiaofen , Chen Jake Yue
Published: March 2010

We propose a new network visualization technique using scattered data interpolation and surface rendering, based upon a foundation layout of a scalar field. Contours of the interpolated surfaces are generated to support multi-scale visual interaction for data exploration. Our framework visualizes quantitative attributes of nodes in a network as a continuous surface by interpolating the scalar field, therefore avoiding scalability issues typical in conventional network visualizations while also maintaining the topological properties of the original network. We applied this technique to the study of a bio-molecular interaction network integrated with gene expression data for Alzheimer's Disease (AD). In this application, differential gene expression profiles obtained from the human brain are rendered for AD patients with differing degrees of severity and compared to healthy individuals. We show that this alternative visualization technique is effective in revealing several types of molecular biomarkers, which are traditionally difficult to detect due to ‘noises’ in data derived from DNA microarray experiments.
Current fluctuations in three-dimensionally stacked Si nanocrystals thin films
Authors: Zhou Xin , Uchida Ken , Oda Shunri
Published: March 2010

In this letter, we report a phenomenon of the current fluctuations by measuring lateral conduction of the three-dimensionally stacked Si nanocrystal (SiNC) thin films based on thin film transistor structures. Through measuring current-voltage (I-V) characteristics, drain-source current (Ids) exhibits fluctuations in particular gate voltage (Vg) and drain voltage (Vds) ranges. The experimental results show that the characteristics of the current fluctuations are changed with changing the charging situations of the SiNC thin films. The phenomenon of the current fluctuations can be well explained by the model that the conduction is dominated by the charging/discharging processes of those SiNCs which exist in the intersection of the several current paths.
On electrical phenomena in electroneutral superfluid systems
Authors: Shevchenko S. I. , Rukin A. S.
Published: March 2010

Keldysh’s theory of a rarefied superfluid electron-hole gas is extended to the case of possible pair polarization. It is established that the complex order parameter Φ(r1,r2), which is the wave function of a pair, satisfies a nonlinear, nonlocal, integrodifferential equation. The equation obtained is solved for the order parameter varying slowly over a distance of the order of the pair size. The dipole-moment density of the system is found from the known function Φ(r1,r2), and it is shown that the inhomogeneity of the system engenders a dipole moment proportional and oriented parallel to the gradient of the particle density. It is determined that an additional dipole moment associated with pair polarization due to the Lorentz force appears in a magnetic field.
A mixed scenario for the reconstruction of a charged helium surface
Authors: Shikin V. , Klinovaya E.
Published: March 2010

A mixed scenario for the periodic reconstruction of a charged surface of a liquid when the liquid is close to occupancy saturation by 2D charges is discussed. It is shown that the unit cell of the periodic structure arising is a modified multicharged dimple.
Detection of self-oscillations of the transport current in a doubly connected superconductor
Authors: Bondarenko S. I. , Koverya V. P. , Krevsun A. V. , Levchenko N. M. , Shablo A. A.
Published: March 2010

It has been found experimentally that when dc current is passed through a circuit consisting of two superconductors connected in parallel and reaches its critical value in one of the circuit branches the current in the branches undergoes quasi-harmonic undamped oscillations. The mechanism resulting in the appearance of the self-oscillations is discussed. The characteristics of magnetic field freezing in a circuit with self-oscillating current are examined.
Thermophysical properties of the manganites (Nd,Sm,Eu)0.55Sr0.45MnO3
Authors: Aliev A. M. , Batdalov A. B. , Gamzatov A. G.
Published: March 2010

The specific heat, thermal diffusivity, and thermal conductivity of ceramic samples of Nd0.55Sr0.45MnO3, Sm0.55Sr0.45MnO3, and Eu0.55Sr0.45MnO3 in the temperature range 20–350K have been measured. Anomalies due to magnetic phase transitions have been observed and are interpreted. The temperature dependence of the free-path length is traced. The dependence of the measured coefficients on the degree of cationic disorder due to the difference of the radii of the A cations is determined.
On the galvanomagnetic properties of α-uranium at low temperatures
Authors: Kuz’menko V. M. , Chernyaeva T. P.
Published: March 2010

The magnetoresistance of and Hall effect in polycrystalline α-U in the temperature interval 4.2–77K and transverse magnetic fields B to 4T have been investigated. It is found that below 43K the Hall coefficient RH of α-uranium depends on the magnetic field. The strong temperature dependence of the RH below 43K which is due to three charge-density-wave type transitions is confirmed. Above 43K the Hall coefficient is weakly temperature dependent and is independent of the magnetic field. The magnetoresistance is approximately parabolic and does not exhibit any indications of saturating even in strong fields. The application of the isotropic two-band model made it possible to evaluate qualitatively the dependence of the charge carrier density n and mobility μ on the magnetic field (to 4T) and on the temperature in the interval 4.2–77K. It is shown that charge-density-wave type transitions at T<43K are accompanied by a considerable change in n and μ. It is found that at 4.2K n and μ depend strongly on the magnetic field from 0 to 4T. There is no such dependence at temperatures T⩾50K.
Spin injection and giant tunnel-current blocking in ferromagnet-superconductor heterostructures
Authors: Rudenko É. M. , Korotash I. V. , Kudryavtsev Yu. V. , Krakovnyĭ A. A. , Belogolovskiĭ M. A. , Boĭlo I. V.
Published: March 2010

Giant growth of the differential resistance has been observed in a tunnel junction consisting of superconducting lead with Heusler’s ferromagnetic alloy Co2CrAl for low bias voltages. This effect is attributed to the appearance of a nonequilibrium state in the lead film as a result of spin injection into the superconductor.
Structure of the low-temperature phase of hexafluoroethane
Authors: Klimenko N. A. , Gal’tsov N. N. , Prokhvatilov A. I.
Published: March 2010

X-Ray studies of C2F6 polycrystals have been performed in the temperature interval 6–140K. The low-temperature phase is found to have a monoclinic structure with lattice parameters at 6K a=8.9725Å, b=4.9546Å, c=9.3936Å, and β=95.07deg. The unit cell contains four molecules. The x-ray data are analyzed together with previously obtained neutron diffraction data. On this basis the space symmetry group P21∕m(C2h2) is proposed for the low-temperature phase of C2F6. It is determined that the orientational structural phase transition at 103.97K of the monoclinic lattice into a cubic body-centered lattice is accompanied by a large volume jump ΔV∕V=4.01%. This explains the large overcooling and overheating observed for the phases in solid hexafluoroethane. A detailed comparative analysis is performed of the crystal structure and physical properties of the solid phases of ethane and the haloethanes C2F6, C2Cl6, and C2Br6.