bluuebunny/crossref_metadata_2025 huggingface dataset:
Trailing Edge Film
Cooling of Gas Turbine Airfoils—External Cooling Performance of Various Internal Pin Fin
Configurations
Authors: Horbach T. , Schulz A. , Bauer H.-J.
Published: April 2011

The present paper describes an experimental study on trailing edge film cooling of modern high pressure turbine blades using coolant ejection through planar slots on a pressure side cutback. The experimental test section consists of a generic scaled-up trailing edge model in an atmospheric open loop wind tunnel, which has been used in several earlier studies. An infrared thermographic measurement technique is employed, which allows for the application of engine-realistic density ratios around 1.6 by increasing the main flow temperature. The effects of different geometric configurations on the structure and performance of the cooling film are investigated in terms of film cooling effectiveness, heat transfer, and discharge behavior. Among other issues, the interaction of internal turbulators, namely, an array of pin fins, with the ejection slot lip is of major interest. Therefore, different designs of the coolant ejection lip are studied. Four different ratios of lip thickness to ejection slot height (t/H=0.2,0.5,1.0,1.5), as well as three different lip profiles representing typical manufacturing imperfections and wear, are investigated. Other geometric variations comprise elliptic pin fins with spanwise and streamwise orientations and the application of land extensions from the internal coolant cavity onto the cutback surface. The blowing ratio is varied at 0.2<M<1.25. In terms of film cooling effectiveness, the results show a strong dependency on ejection lip thickness, and minor improvements are obtained with a rounded ejection lip profile. Significant improvements are achieved using land extensions. The elliptic pin fins have a strong effect on discharge behavior as well as on film cooling effectiveness and heat transfer. Except for the elliptic pin fins, the geometric variations have only a minor influence on heat transfer.
Experimental and Numerical Cross-Over Jet Impingement in an Airfoil Trailing-Edge Cooling Channel
Authors: Taslim M. E. , Nongsaeng A.
Published: April 2011

Trailing edge cooling cavities in modern gas turbine airfoils play an important role in maintaining the trailing-edge temperature at levels consistent with airfoil design life. In this study, local and average heat transfer coefficients were measured in a test section, simulating the trailing-edge cooling cavity of a turbine airfoil using the steady-state liquid crystal technique. The test rig was made up of two adjacent channels, each with a trapezoidal cross-sectional area. The first channel, simulating the cooling cavity adjacent to the trailing-edge cavity, supplied the cooling air to the trailing-edge channel through a row of racetrack-shaped slots on the partition wall between the two channels. Eleven crossover jets issued from these slots entered the trailing-edge channel and exited from a second row of race-track shaped slots on the opposite wall in staggered or inline arrangement. Two jet angles were examined. The baseline tests were for zero angle between the jet axis and the trailing-edge channel centerline. The jets were then tilted toward one wall (pressure or suction side) of the trailing-edge channel by 5 deg. Results of the two set of tests for a range of local jet Reynolds number from 10,000 to 35,000 were compared. The numerical models contained the entire trailing-edge and supply channels with all slots to simulate exactly the tested geometries. They were meshed with all-hexa structured mesh of high near-wall concentration. A pressure-correction based, multiblock, multigrid, unstructured/adaptive commercial software was used in this investigation. Standard high Reynolds number k−ε turbulence model in conjunction with the generalized wall function for most parts was used for turbulence closure. Boundary conditions identical to those of the experiments were applied and several turbulence model results were compared. The numerical analyses also provided the share of each cross-over and each exit hole from the total flow for different geometries. The major conclusions of this study were (a) except for the first and last cross-flow jets which had different flow structures, other jets produced the same heat transfer results on their target surfaces, (b) jets tilted at an angle of 5 deg produced higher heat transfer coefficients on the target surface. The tilted jets also produced the same level of heat transfer coefficients on the wall opposite the target wall, and (c) the numerical predictions of impingement heat transfer coefficients were in good agreement with the measured values for most cases; thus, computational fluid dynamics could be considered a viable tool in airfoil cooling circuit designs.
Ad-Hoc Boundary Conditions for CFD Analyses of Turbomachinery Problems With Strong Flow Gradients at Farfield Boundaries
Authors: Campobasso M. Sergio , Baba-Ahmadi Mohammad H.
Published: April 2011

This paper reports on the improvements of flux enforcement and auxiliary state farfield boundary conditions for Euler and Navier–Stokes computational fluid dynamics (CFD) codes. The new conditions are based on 1D characteristic data and also on the introduction in the boundary conditions of certain numerical features of the numerical scheme used for the interior of the domain. In the presence of strong streamwise gradients of the flow field at the farfield boundaries, the new conditions perform significantly better than their conventional counterparts in that they (a) preserve the order of the space-discretization and (b) greatly reduce the error in estimating integral output. A coarse-grid CFD analysis of the compressible flow field in an annular duct for which an analytical solution is available yields a mass flow error of 62% or 2%, depending on whether the best or the worst farfield boundary condition (BC) implementation is used. The presented BC enhancements can be applied to structured, unstructured, cell-centered, and cell-vertex solvers.
Electronic Medical Records for Genetic Research: Results of the eMERGE Consortium
Authors: Kho Abel N. , Pacheco Jennifer A. , Peissig Peggy L. , Rasmussen Luke , Newton Katherine M. , Weston Noah , Crane Paul K. , Pathak Jyotishman , Chute Christopher G. , Bielinski Suzette J. , Kullo Iftikhar J. , Li Rongling , Manolio Teri A. , Chisholm Rex L. , Denny Joshua C.
Published: April 2011

Clinical data captured in electronic medical records accurately identify cases and controls for genome-wide association studies.
HIV-1 Vaccines and Adaptive Trial Designs
Authors: Corey Lawrence , Nabel Gary J. , Dieffenbach Carl , Gilbert Peter , Haynes Barton F. , Johnston Margaret , Kublin James , Lane H. Clifford , Pantaleo Giuseppe , Picker Louis J. , Fauci Anthony S.
Published: April 2011

Development of an HIV vaccine could be accelerated by testing candidate vaccines using adaptive clinical trial designs.
The Fate and Toxicity of Raman-Active Silica-Gold Nanoparticles in Mice
Authors: Thakor Avnesh S. , Luong Richard , Paulmurugan Ramasamy , Lin Frank I. , Kempen Paul , Zavaleta Cristina , Chu Pauline , Massoud Tarik F. , Sinclair Robert , Gambhir Sanjiv S.
Published: April 2011

Gold-core nanoparticles designed for imaging by Raman spectroscopy in patients are generally nontoxic in mice, causing only temporary liver inflammation when given intravenously.
The Power of Epistasis
Authors: Nielson Carrie M.
Published: April 2011

Mutations in human immunodeficiency virus genes work together to heighten drug resistance.
On the reliability of the corrected semiempirical quantum chemical method (PM6-DH2) for assigning the protonation states in HIV-1 protease/inhibitor complexes
Authors: Pecina Adam , Přenosil Ondřej , Fanfrlík Jindřich , Řezáč Jan , Granatier Jaroslav , Hobza Pavel , Lepšík Martin
Published: April 2011

A novel computational protocol for determining the most probable protonation states in protein/ligand complexes is presented. The method consists in treating large parts of the enzyme using the corrected semiempirical quantum chemical (QM) method – PM6-D2 for optimization and PM6-DH2 for single-point energies – while the rest is calculated using molecular mechanics (MM) within a hybrid QM/MM fashion. The surrounding solvent is approximated by an implicit model. This approach is applied to two model systems, two different carboxylate pairs in one general and one unique HIV-1 protease/inhibitor complex. The effect of the size of the movable QM part is investigated in a series of several sizes, 3-, 6-, 8- and 10-Å regions surrounding the inhibitor. For the smallest region (< 450 atoms) the computationally more costly DFT QM/MM optimizations are performed as a check of the correctness. Proton transfer (PT) phenomena occur at both the PM6-D2 and DFT levels, which underlines the requirement for a QM approach. The barriers of PT are checked in model carboxylic acid pairs using the highly accurate MP2 and CCSD(T) values. An important result of this study is the fine-tuning of the protocol which can be used in further applications; its limitations are also shown, pointing to future developments. The calculations reveal which protonation variants of the active site are the most stable. In conclusion, the presented protocol can also be utilized for defining probable isomers in biomolecular systems. It can also serve as a preparatory step for further interaction-energy and binding-score calculations.
Consensus for Dry Needling for Plantar Heel Pain (Plantar Fasciitis): A Modified Delphi Study
Authors: Cotchett Matthew P , Landorf Karl B , Munteanu Shannon E , Raspovic Anita M
Published: April 2011

Hypothesis

Plantar heel pain (plantar fasciitis) is a common and disabling condition. A variety of treatment options are available to patients with plantar heel, however the evidence for these treatments is generally weak and the best way to manage plantar heel pain remains unclear. Trigger point dry needling is increasingly used as an adjunct therapy for musculoskeletal pain. In patients with plantar heel pain this technique is thought to improve muscle activation patterns, increase joint range of motion and alleviate pain. However, there have been no randomised controlled trials that have evaluated the effectiveness of dry needling for plantar heel pain.

Methods

In order to develop a treatment protocol to evaluate the effectiveness of dry needling for plantar heel pain we conducted a three stage modified Delphi process using a web-based survey technique. Over a series of three iterations, 30 experts (participants) worldwide indicated their level of agreement on specific issues relating to the use of dry needling for plantar heel pain including their treatment rationale, needling details and treatment regimen. Consensus for a dry needling protocol for plantar heel pain was achieved when >60% of participants (IQR ≤ 1.0 category on 5-point Likert scale) agreed the protocol was adequate.

Results

The response rate was 75% (n=30), 100% (n=30) and 93% (n=28) in the first, second and third rounds respectively. Round 1 helped generate a list of 10 items that were deemed important for developing a dry needling protocol for plantar heel pain. These 10 items were subsequently presented in Round 2. Of these, 5 of the 10 items met the criteria to be included in a dry needling protocol for plantar heel pain that was presented in the final round, Round 3. Items that did not meet the criteria were either removed or amended and then presented in Round 3. In the final round, 93% of participants (IQR range = 1) agreed the proposed dry needling protocol for plantar heel pain was adequate. The protocol can now be used in future research projects designed to evaluate the effectiveness of dry needling for plantar heel pain.
Sparrows, hedgehogs and castrati: reflections on gender and enhancement
Authors: Harris John
Published: April 2011

In a number of papers, including the one published in this journal, Robert Sparrow has mounted attacks on consequentialism using principally what he takes to be an important fact, which he believes constitutes areductio ad absurdumof consequentialism in its many forms and of this author's approach to enhancement and disability in particular (see page276). This fact is the current longer life expectancy of women when compared with men. Here the author argues that Sparrow's arguments and entire approach utterly fail. In doing so the author hopes to shed further light on the role of normalcy, normal species functioning and species-typical functioning in debates about enhancement and disability.
UNIVERSALITY IN THE ELECTROPRODUCTION OF VECTOR MESONS
Authors: BALTAR V. L. , DOSCH H. G. , FERREIRA E.
Published: April 2011

We study universality in the data of the electroproduction of vector mesons, using as guideline the results of a unified nonperturbative approach which reproduces well the available experimental data. After the extraction of factors that are specific of each vector meson, we arrive at a reduced integrated elastic cross-section which is universal. Our analysis suggests a finite infrared behavior for the strong coupling constant.
A REMARK ON GROUND STATE OF BOUNDARY IZERGIN–KOREPIN MODEL
Authors: KOJIMA TAKEO
Published: April 2011

We study the ground state of the boundary Izergin–Korepin model. The boundary Izergin–Korepin model is defined by the so-called R-matrix and K-matrix for [Formula: see text] which satisfy Yang–Baxter equation and boundary Yang–Baxter equation. The ground state associated with identity K-matrix [Formula: see text] was constructed by W.-L. Yang and Y.-Z. Zhang in earlier study. We construct the free field realization of the ground state associated with nontrivial diagonal K-matrix.
HIDDEN CONFORMAL SYMMETRY OF ROTATING NS5-BRANES IN EXTREMAL LIMIT
Authors: SETARE M. R. , KAMALI V.
Published: April 2011

We show that extremal rotating NS5-branes space–times have a hidden conformal symmetry. In this regard, we consider the wave equation of a massless scalar field propagating in extremal NS5-branes space–times and find in the "near region," the wave equation in extremal limit can be written in terms of the SL (2, R) quadratic Casimir.

Moreover, we obtain the microscopic entropy of the extremal NS5-branes space–times, also we calculate the correlation function of a near-region scalar field and find perfect agreement with the dual 2D CFT.
ANOMALIES OF E8GAUGE THEORY ON STRING MANIFOLDS
Authors: SATI HISHAM
Published: April 2011

In this paper we revisit the subject of anomaly cancelation in string theory and M-theory on manifolds with string structure and give three observations. First, that on string manifolds there is no E8× E8global anomaly in heterotic string theory. Second, that the description of the anomaly in the phase of the M-theory partition function of Diaconescu–Moore–Witten extends from the spin case to the string case. Third, that the cubic refinement law of Diaconescu–Freed–Moore for the phase of the M-theory partition function extends to string manifolds. The analysis relies on extending from invariants which depend on the spin structure to invariants which instead depend on the string structure. Along the way, the one-loop term is refined via the Witten genus.
CALCULATION OF THE INTENSITY-DEPENDENT ABSORPTION SPECTRUM IN TWO-DIMENSIONAL ELECTRON SYSTEMS
Authors: PHONG TRAN CONG , LAM VO THANH , TUNG LUONG VAN
Published: April 2011

General analytic expression for the intensity-dependent absorption coefficient (IDAC) of an intense electromagnetic wave (IEMW) in two-dimensional electron systems (2DES) is obtained by using the quantum kinetic equation (QKE) for electrons in the case of electron–optical phonon scattering in a doped semiconductor superlattice (DSSL). The dependence of IDAC on the amplitude E0 and the photon energy ℏΩ of an IEMW, the energy ℏωp and the temperature for a specific n-i-p-i superlattice of GaAs : Si / GaAs : Be is achieved due to a numerical method. The computational results show that not only the dependence of IDAC on ℏΩ but also the dependence of IDAC on ℏωp can be applied to optically detect the electric subbands in a DSSL.
ABSENCE OF SPONTANEOUS MAGNETIZATION FOR THE ISING MODEL ON WEAKLY SEPARABLE GRAPHS
Authors: CAMPARI RICCARDO , CASSI DAVIDE
Published: April 2011

We present here a theorem stating sufficient topological conditions for an arbitrary graph not to exhibit spontaneous magnetization at finite temperature. Doing so, we introduce a large class of weakly separable graphs that encompasses all the known cases of lattices not displaying spontaneous magnetization, then we discuss the possibility that this class may contain all and only such graphs.
SPIN-ORBIT COUPLING IN GRAPHENE UNDER UNIAXIAL STRAIN: TIGHT-BINDING APPROACH AND FIRST-PRINCIPLES CALCULATIONS
Authors: GONG BAIHUA , ZHANG XIN-HUI , ZHANG ER-HU , ZHANG SHENG-LI
Published: April 2011

Tuning the spin-orbit coupling (SOC) in graphene is highly desired for its application in spintronics. In this paper, we calculated the band gap induced by SOC in graphene under uniaxial strain from a tight-binding model, and found that the band gap has a monotonic increasing dependence on the strain in the range of -20% to 15%. Our results suggest that strain can be used as a reversible and controllable way to tune the SOC in graphene. First-principles calculations were performed, confirming the results of tight-binding approximation.
EMERGENT SOCIAL LEARNING NETWORKS IN ORGANIZATIONS WITH HETEROGENEOUS AGENTS
Authors: CHANG MYONG-HUN
Published: April 2011

Two distinct learning mechanisms are considered for a population of agents who engage in decentralized search for the common optimum. An agent may choose to learn via innovation (individual learning) or via imitation (social learning). The agents are endowed with heterogeneous skills in engaging in the two modes of learning. When the agents choose imitation, they also choose whom to learn from. This leads to the emergence of a social learning network among agents in the population. This paper focuses on the impact the endowed learning skills have on the individual's choice of learning mechanism as well as the micro and macro structure of the evolving network. Finally, it explores the impact the degree of environmental volatility has on the structure of such networks.
OPTIMAL PAIRWISE ALIGNMENT OF FIXED PROTEIN STRUCTURES IN SUBQUADRATIC TIME
Authors: POLEKSIC ALEKSANDAR
Published: April 2011

The problem of finding an optimal structural alignment for a pair of superimposed proteins is often amenable to the Smith–Waterman dynamic programming algorithm, which runs in time proportional to the product of lengths of the sequences being aligned. While the quadratic running time is acceptable for computing a single alignment of two fixed protein structures, the time complexity becomes a bottleneck when running the Smith–Waterman routine multiple times in order to find a globally optimal superposition and alignment of the input proteins. We present a subquadratic running time algorithm capable of computing an alignment that optimizes one of the most widely used measures of protein structure similarity, defined as the number of pairs of residues in two proteins that can be superimposed under a predefined distance cutoff. The algorithm presented in this article can be used to significantly improve the speed–accuracy tradeoff in a number of popular protein structure alignment methods.
DETERMINISTIC SECURE QUANTUM COMMUNICATION WITH FOUR-QUBIT W STATES
Authors: YUAN HAO , SONG JUN , LIU XIANG-YUAN , CHENG SHAN , HOU KUI , HAN LIAN-FANG
Published: April 2011

We propose a new protocol for deterministic secure quantum communication with a four-qubit W state. In this protocol, by using four local two-particle unitary operations and Bell basis measurements, the two legitimate users can directly transmit secret messages after exchanging some additional classical information. It will be shown that our protocol has a high capacity as each W state can carry two bits of secret information, and has a high intrinsic efficiency because almost all the instances are useful. Furthermore, this protocol is feasible with present day techniques.
REALIZATION OF QUANTUM LOGIC GATES AND CLUSTER STATES WITH SUPERCONDUCTING QUANTUM-INTERFERENCE DEVICES
Authors: ZHAN ZHIMING
Published: April 2011

We propose a method for realizing quantum logic gates and cluster states with superconducting quantum-interference devices (SQUIDs) in cavity QED via Raman transition. In this proposal, quantum logic gates and cluster states are realized by using only two lower flux states of the SQUID system and the excited state would not be excited. Therefore, the effect of decoherence caused by the levels of the SQUID system is possibly minimized.
LINEAR OPTICAL IMPLEMENTATION OF DISCRETE QUANTUM FOURIER TRANSFORM WITH CONVENTIONAL PHOTON DETECTORS
Authors: WANG HONG-FU , ZHANG SHOU , YEON KYU-HWANG
Published: April 2011

We present a linear optical scheme for implementing two-bit discrete quantum Fourier transform based only on simple linear optical elements, a pair of two-photon polarization entangled states, and the conventional photon detectors that only distinguish between the presence and absence of the photons. The scheme can be implemented with a certain success probability, and the implementation of the scheme in experiment would be an important step towards more complex linear optical quantum computation.
ENTANGLEMENT DEATH AND PURITY LOSS FOREVER IN THE DISPERSIVE INTERACTION OF A TRAPPED ION AND LIGHT WITHOUT ENERGY RELAXATION
Authors: MOHAMED ABDEL-BASET A.
Published: April 2011

Death of entanglement between light and the vibrational motion of a single trapped ion in the dispersive regime with a reservoir is investigated. It is found that with phase-damped cavity, the purity of the light-motional states is lost forever, unlike the purity of the ion's internal states which have regular patterns and they do not decay. The asymptotic behavior of the states of the light, the ion-motional and the total system fall into a mixed state. The entanglement and purity have strong sensitivity to the phase damping and the ionic distribution angle. The entanglement sudden death has been treated as it arises from the effect of phase damping on mixed as well as pure states.
VIRTUAL EYE — THE BLIND CHILD NAVIGATION MODEL USING WIRELESS SENSOR NETWORK
Authors: AMUTHA B. , PONNAVAIKKO M.
Published: April 2011

The visions of context-sensitive services, ubiquitous computing, and ambient intelligence have driven several aspects of wireless sensor networks research, but perhaps none more so than localization and tracking. Location of a user is one of the most fundamental types of context, and can be applied in a vast number of environments from smart homes to improved security solutions. However, accurate localization of users is not trivial, and most of the individual systems presented suffer from coverage problems. We present a system-level approach to localize and track normal and blind users on the basis of different sources of location information. The system can be applied outdoors and indoors using GPS and Zigbee as the source of location data. The overall system architecture is modular and extendible, allowing for creation of location- and context-aware services for blind child tracking with the inclusion of additional sources of localization data. Extensive performance evaluation presented for blind child navigation shows that the system is both accurate as well as scalable.
A NOVEL APPROACH FOR IMAGE COMPRESSION USING LIFTING TECHNIQUE AND TSVQ
Authors: MUTHULAKSHMI G. , SADASIVAM V.
Published: April 2011

The objective of image compression is to reduce the redundant amount of data and to achieve low bit rate without any apparent loss of image quality. In this paper, the compression process is achieved by using wavelet transform with lifting technique for decomposition and tree-structured vector scheme for quantization. Huffman coding method is used for encoding stage. Wavelet technique provides the most promising tool for high-quality image compression. Lifting transform provides a flexible tool for the construction of sub-band decomposition and perfect reconstruction. TSVQ has its advantages over conventional vector quantization by minimizing the computational complexity. Huffman coding is used for efficient coding of images at lower bit rate with minimal loss of information. The performance of the proposed work has been assessed with parameters like bits per pixel (bpp), compression ratio (CR), peak signal to noise ratio (PSNR), codebook size (CS), and mean squared error (MSE). The experimental results show that the proposed work yields a higher compression with better quality reconstructed image than the other conventional compression methods.
A MULTIFUNCTIONAL AND PORTABLE OPTICAL SENSOR FOR QUANTITATIVE CHARACTERIZATION OF 3D SURFACE TEXTURE PROPERTIES
Authors: SHEN YANTAO , WANG YONGXIONG , XI NING
Published: April 2011

Surface characterization technologies are generally sorted into two categories: noncontact and contact-based technologies. Among these technologies, no one can stand out to simultaneously and rapidly measure both surface patterns/textures and mechanical properties such as softness, friction, and mechanical impedance. In this paper, we have addressed this problem and developed a multifunctional and portable surface texture sensor through combination of both contact and noncontact optical surface profiling mechanisms. The developed sensor relying on an optomechanical principle can be efficiently used for quantitative characterization of surface texture properties including 3D texture pattern, roughness, and even mechanical properties like softness, etc. As one of the important applications, we have used the sensor to measure and analyze texture properties of extensive automotive interior leather sample surfaces. The results demonstrate that the sensor can effectively assist the interior designer to quantify and classify essential texture features of automobile interior surfaces.
POSITIVE PERIODIC SOLUTIONS FOR A GENERALIZED IMPULSIVE N-SPECIES GILPIN–AYALA COMPETITION SYSTEM WITH CONTINUOUSLY DISTRIBUTED DELAYS ON TIME SCALES
Authors: ZHANG TIANWEI , LI YONGKUN
Published: April 2011

In this paper, we study a generalized impulsive n-species Gilpin–Ayala competition system with continuously distributed delays on time scales in periodic environment, which is more general and more realistic than the classical Lotka–Volterra competition system. By using a fixed point theorem of strict-set-contraction, some sufficient conditions are obtained for the existence of at least one positive periodic solution. Finally, we present an example to illustrate that our results are effective.
BOUNDEDNESS AND EXPONENTIAL STABILITY FOR NONAUTONOMOUS FCNNs WITH REACTION-DIFFUSION TERMS AND TINE-VARYING DELAYS
Authors: NIU SHUYUN , JIANG HAIJUN , TENG ZHIDONG
Published: April 2011

In this paper, a class of nonautonomous fuzzy cellular neural networks (FCNNs) with reaction-diffusion terms and time-varying delays are investigated. By applying the inequality analysis technique, introducing ingeniously many real parameters and constructing new auxiliary functions, a series of new and useful criteria on the boundedness and globally exponential stability of solutions are established. The results obtained in this paper extend and improve the corresponding results given in previous works. Finally, two examples are given to verify the effectiveness of the obtained results.
A BIOLOGICAL MEANING IN ASYMPTOTIC STABILITY OF THE DELAY LOGISTIC DIFFERENTIAL EQUATIONS
Authors: LI HAICHUN
Published: April 2011

In this paper, we study the asymptotic stability of solutions of the delay logistic differential equations. We obtain the important formula (N + 1)rτ < π by reducing the characteristic equations, where r is the related to the reproduction of the single species; τ is the potential period (or the propagate period) of the single species; N is the generations of the single species per year. The formula has an important biological meaning on the reproduction for single species population.
A MATHEMATICAL MODEL OF THE PHYSICAL GROWTH MECHANISM AND GEOMETRICAL CHARACTERIZATION OF GROWING FORMS
Authors: SHESTOPALOFF YURI K.
Published: April 2011

The article introduces a mathematical model of the physical growth mechanism which is based on the relationships of the physical and geometrical parameters of the growing object, in particular its surface and volume. This growth mechanism works in cooperation with the biochemical and other growth factors. We use the growth equation, which mathematically describes this mechanism, and study its adequacy to real growth phenomena. The growth model very accurately fits experimental data on growth of Amoeba, Schizosaccharomyces pombe, E.coli. Study discovered a new growth suppression mechanism created by certain geometry of the growing object. This result was proved by experimental data. The existence of the growth suppression phenomenon confirms the real workings and universality of the growth mechanism and the adequacy of its mathematical description. The introduced equation is also applicable to the growth of multicellular organisms and tumors. Another important result is that the growth equation introduces mathematical characterization of geometrical forms that can biologically grow. The material is supported by software application, which is released to public domain.
POTENTIAL OF IN VIVO LATENT-TIME ESTIMATION BY LASER AND OPTICAL TECHNIQUES IN CLINICAL AND EXPERIMENTAL DERMATOLOGY
Authors: EIKJE NATALJA SKREBOVA
Published: April 2011

The lag (latency) time (LT) is known in dermatology clinic as an asymptomatic period till the development of skin eruptions. In the laboratory, the LT might determine the interval from "zero" point until the peak(s) of changes in measured laboratory parameter during the performed test. This paper discusses methodological and technical aspects of precise measurement of the LT in the living healthy and pathological skin by laser and optical technologies through clinical and experimental applications in dermatology. Based on a dynamics approach to measure, calculate and interpret the LT in blood and in interstitial fluid compartments of the skin tissue, this method has a potential to promote deeper understanding of the role of complex dynamic processes in the skin at a level of a molecule, and/or an organ in a whole organism. The method of the LT measurement in vivo also promotes new understanding of (patho)physiological, diagnostic and pharmacological aspects of certain dynamic skin lesions and dynamic complex processes that happen in the skin. Utilized laser and optical techniques showed high reliability and objectivity in collecting data from rapidly changed skin lesions and processes, demonstrating the LT measurement as a very easy-to-use calculation procedure with high informativity, which is extremely important for the clinical and laboratory environment.
ANALYTICAL SOLUTION OF WEDGE WATER ENTRY BY USING SCHWARTZ–CHRISTOFFEL CONFORMAL MAPPING
Authors: GHADIMI PARVIZ , SAADATKHAH AMIR , DASHTIMANESH ABBAS
Published: April 2011

Water impact is one of the most critical phenomena from the viewpoint of the structural design of ships and offshore structures. The impact force can impose a large load with high local pressure on the body surface. On the other hand, determination of the maximum impact force during impact and acting point itself is very important in the design of floats.

In this paper, the water entry of a two-dimensional wedge section is considered. This study is carried out in the framework of a potential-flow assumption. In particular, water impact on a dropping wedge with a constant velocity is pursued analytically by using the Schwartz–Christoffel conformal mapping. In order to determine a position of the wedge where the instantaneous effective force is largest during the impact, a particular equation is introduced here for the first time. The pressure distribution and maximum impact force are also calculated. The obtained results are compared against other numerical and experimental works and favorable agreement is displayed.
Effect of Introducing β-FeSi2 Template Layers on Defect Density and Minority Carrier Diffusion Length in Si Region near p-β-FeSi2/n-Si Heterointerface
Authors: Kawakami Hideki , Suzuno Mitsushi , Akutsu Keiichi , Chen Jun , Jiptner Karolin , Sekiguchi Takashi , Suemasu Takashi
Published: April 2011

The electrical properties of defects in a p-β-FeSi2/n-Si heterostructures were investigated by deep level transient spectroscopy (DLTS) and the electron-beam-induced current (EBIC) technique. DLTS revealed the presence of trap levels for holes, caused by defects in the n-Si layer near the interface during the β-FeSi2 film fabrication. The defect density became small when a 20-nm-thick β-FeSi2 template layer was grown on the n-Si prior to molecular beam epitaxy (MBE) of a 700-nm-thick β-FeSi2 layer. The diffusion length of minority carriers in the n-Si was found to be approximately 15 µm by EBIC. This is much larger than the value of approximately 3 µm for the n-Si obtained when the template layer was not inserted.
Ultraviolet-Light-Induced Desorption of Oxygen from SrTiO3 Surfaces
Authors: Hara Toru , Ishiguro Takashi , Shinozaki Kazuo
Published: April 2011

We have previously reported that SrTiO3-based thin films can be used to detect trace amounts of oxygen (e.g., down to 0.001 ppt). However, the SrTiO3 surfaces are highly active against oxygen adsorption. Therefore, the slow desorption response can affect the response speed of the sensors against the sudden change in oxygen concentration. We have reported that UV light irradiation is effective for accelerating oxygen desorption, and in this paper, we will show that the increase in the irradiation intensity of UV light can be an efficient way of improving the response speed. As an example, an apparent hysteresis in the sensor resistance versus oxygen concentration curve, which is shown after the UV irradiation at a low intensity, diminishes after the UV irradiation at a high intensity, even after short-lasting treatments.
Injection-Current-Induced Blue-Shift Laser Diode: Concept of Excess Carrier Conservation
Authors: Murasawa Kengo , Hidaka Takehiko , Sato Koki
Published: April 2011

We report the blue-shift characteristics of continuous-wave oscillation wavelength induced by the current injection of a GaAs-base laser diode. Typical laser diodes show red-shift characteristics owing to the band-gap narrowing induced by a rise in the temperature of the active layer upon current injection. The cause of the blue shift in the laser diode reported here is the effect of the conserved excess-carrier-induced refractive-index reduction, which is superior to the temperature-rising effect. We try to construct a new simple model to explain such blue-shift characteristics.
Light Output Power Enhancement of GaN-Based Light Emitting Diodes with Periodic Deflector Embedded on the Wet Etch Patterned Sapphire Substrate
Authors: Kim Hyun Kyu , Kim Hyung Gu , Kim Hee Yun , Ryu Jae Hyoung , Kang Ji hye , Han Nam , Kwon Bong Jun , Uthirakumar Periyayya , Han Myung Soo , Kang Sin Ho , Hong Chang-Hee
Published: April 2011

In this work, light-emitting diodes (LEDs) are fabricated with periodic deflector embedded (PDE) on the wet etch patterned sapphire substrate (PSS). A wet etching technique is employed to form the PDE-PSS structures. The performance of the PDE and PDE-PSS LEDs were compared with the conventional LEDs. The light output power of the PDE and PDE-PSS LEDs were enhanced by the factor of 40 and 60%, respectively, compared to that obtained from conventional LEDs. The light trajectories that are guided along the epilayer in the LEDs can be extracted by the helps of periodic deflectors as well as a typical PSS structure.
A Nonpolar a-Plane GaN Grown on a Hemispherical Patterned r-Plane Sapphire Substrate
Authors: Yoo Geunho , Park Hyunsung , Lim Hyoungjin , Lee Seunga , Nam Okhyun , Moon Youngboo , Lim Chaerok , Kong Bohyun , Cho Hyungkoun
Published: April 2011

A high-quality a-plane GaN layer with a pit-free, mirror-like surface was grown on a hemispherical patterned r-plane sapphire substrate (PSS) by metal–organic chemical vapor deposition. The use of the r-plane PSS reduced the density of defects such as basal plane staking faults and threading dislocations of the a-plane GaN. The low-temperature-photoluminescence intensity of the emissions at 3.25 and 3.39 eV related with the defects increased along with the near-band-edge emission at 3.46 eV. The intensity of yellow emission at 2.2 eV on the PSS was remarkably decreased, which indicates the improvement of the crystal quality because of the defect reduction. The InGaN light emitting diode grown on the PSS showed an output power of 7.4 mW at 100 mA, which was about 7 times higher than that on the planar substrate.
Composition and Characterization of Femtosecond Optical Lattices Using Double Axicon Holographic Pattern
Authors: Hwang Sung In , Song Dong Hoon , Ko Do-Kyeong
Published: April 2011

We demonstrate a method for tailoring the light structure of a femtosecond field using a double-axicon holographic pattern without compensating for additional angular dispersion elements. Tailored light structured on the femtosecond field can be obtained by creating a pair of femtoseond Bessel beams and synthesize them. The spatial property of tailored light structure on femtosecond field investigated and compared to the CW case. We also showed the temporal characteristics of the tailored femtosecond light structure can be expressed by the interference of Bessel beams with different time shift.
Generation of Quasi-CW Deep Ultraviolet Light below 200 nm by Two Successive Cavity Enhanced Second Harmonic Generators
Authors: Zhang Yun , Watanabe Nobuyoshi , Okada-Shudo Yoshiko , Watanabe Masayoshi , Hyodo Masaharu , Wang Xiaoyang , Zhu Yong , Chen Chuangtian , Kanai Teruto , Watanabe Shuntaro
Published: April 2011

By frequency quadrupling a picosecond pulse train from a Ti: Sapphire laser with a wavelength of 798 nm and a repetition rate of 82 MHz, we generated a coherent deep ultraviolet light below 200 nm. Two frequency-doubling stages take place in resonant cavities that can increase conversion efficiency. This allows an overall efficiency of 4.3% and produces an output power of up to 60 mW. In the second stage, in which a KBe2BO3F2(KBBF) crystal was employed as a nonlinear medium, conversion efficiency is increased by about three times compared with that of the single-pass configuration. Taking into account reflective loss, conversion efficiency is improved five times.
High Rate Reactive Sputter Deposition of TiO2 Films for Photocatalyst and Dye-Sensitized Solar Cells
Authors: Sato Yasushi , Hashimoto Takahiro , Miyamura Amica , Ohno Singo , Oka Nobuto , Suzuki Koichi , Glöß Daniel , Frach Peter , Shigesato Yuzo
Published: April 2011

We fabricated dye-sensitized solar cells (DSCs) using TiO2 films deposited on various substrates by reactive magnetron sputtering with midfrequency pulsing and process control units, and evaluated their performance. Two pulse modes, i.e., unipolar pulse and pulse packet modes, were utilized to deposit TiO2. The highest conversion efficiency achieved was 3.7% when 10-µm-thick TiO2 films were deposited on glass substrates coated with fluorine-doped tin oxide (FTO) using the unipolar pulse mode in the oxide mode and postannealing in air. On the other hand, the conversion efficiency achieved was 2.7% for cells with 10-µm-thick TiO2 films deposited on glass substrates coated with FTO using the pulse packet mode without postannealing, and it dropped to 1.3% when the unipolar pulse mode was used. The relationships between the photocatalytic decomposition activity and the DSC characteristics with regard to the TiO2 films were investigated in detail. The reduction in the density of defects in the TiO2 films led to an improvement in both the photocatalytic activity and the DSC characteristics.
Crystallization Properties of Ge1-xSbx Thin Films (x = 0.58–0.88)
Authors: Kim Byeong Geun , Bae Jun-Hyun , Jeong Seong-Min , Choi Soon-Mok , Lee Hong-Lim
Published: April 2011

The binary phase-change material Ge1-x
Sb
x
films (x = 0.58–0.88) were deposited using a dc co-sputtering system to study their crystallization behaviors after heat treatment and laser irradiation. As the concentration of Sb in Ge1-x
Sb
x
thin films decreased, both the crystallization temperatures and sheet resistances of the amorphous and crystalline phases increased. The crystallization of Ge0.12Sb0.88 thin film was accompanied with Ge precipitation, which brings about a rough surface and poor optical reflectivity. The thin films around the eutectic composition showed different optical properties through their crystalline behaviors on a nanosecond scale. The Ge0.12Sb0.88 thin film represented a large change in reflectivity when treated under a weak laser power and at a very short crystallization time (25 ns).
Microstructure Affecting Magnetoresistance of a Cu75–Fe5–Ni20 Alloy
Authors: Kang Sung , Takeda Mahoto , Bae Dong-Sik , Takanashi Koki , Mizuguchi Masaki
Published: April 2011

The electromagnetic properties of a Cu75–Fe5–Ni20 alloy have been investigated upon isothermal annealing of the alloy at 873 K, using a superconducting quantum interference device (SQUID) magnetometer and a physical property measurement system (PPMS) instrument. Magnetoresistance (MR) was closely related to the magnetization value in specimens of the alloy. The most striking finding of the present work is that the as-quenched specimen with no visible precipitates attains the largest MR (∼16% at H=7 T and T=10 K), although fine precipitates with a proper size were thought to be essential in our previous studies. The present investigation also revealed that several significant effects accompanied the magnetic and magnetoresistive properties, with microstructural evolution occurring during the phase decomposition of a Cu75–Fe5–Ni20 alloy.
Research on Reaction Method of High Removal Rate Chemical Mechanical Polishing Slurry for 4H-SiC Substrate
Authors: Nitta Hiroshi , Isobe Akira , Hong Park , Hirao Takashi
Published: April 2011

In this study, the high removal rate silicon carbide (SiC) chemical mechanical polishing (CMP) slurry was researched to reduce polishing process time. At first, oxidizing reaction was researched to understand the effectiveness of oxidizer in SiC polishing mechanism and then oxidizer was optimized to increase reactivity for high SiC removal at the point of kinds and amount. Next research was to find out additives to reduce polishing time by making brittle layer at SiC surface. This brittle layer can faster be removed at polishing process than without additives. As a result, through this research, we could achieve high 4H-SiC removal CMP Slurry using optimization of oxidizer and additives.
Nonreciprocal Propagation Characteristics of 2.5 THz Submillimeter Wave in Two-Layer Parallel-Plate Waveguide Containing n-InSb Slab at Room Temperature
Authors: Yodokawa Shinichi , Fujieda Yutaka , Obunai Tetsuo
Published: April 2011

The temperature and magnetic field dependences of 2.5 THz submillimeter-wave propagation characteristics in a transversely magnetized two-layer parallel-plate waveguide containing an n-type InSb slab have been studied theoretically and experimentally at room temperature. The results show the formation of a resonant peak in the experimental transmission, which corresponds to the theoretically predicted slow surface wave resonance. Particularly at 295 K, a nonreciprocity of more than 20 dB is observed in the experimental transmission at the applied magnetic field of 0.5 T. The results also indicate the possibility of applying our waveguide configuration to terahertz-wave nonreciprocal devices operating at room temperature.
Light Controlled Piezoelectric Transformer
Authors: Kozielski Lucjan
Published: April 2011

The author designed “smart material” device allow to control an output voltage level by change of incident light intensity. New functions of piezoelectric transformer (PT) was realized by superimposing piezoelectricity with photostriction. The effect of a light influence on the PT voltage gain was proved experimentally, consequently these “smart” transformers with its new functionality can be utilized as a promising devices relevant to consumers market for adopting illumination intensity of PT supplied light sources to the surrounding conditions.
Test of Universal Rise of Hadronic Total Cross Sections Based on πp, Kp, \-pp and pp Scatterings
Authors: Ishida Muneyuki , Igi Keiji
Published: April 2011

There are several evidences of the hadronic total cross section σtot to be proportional to B log2s consistent with the Froissart unitarity bound. The COMPETE collaboration has further assumed σtot ≃ B log2(s/s0) + Z to extend its universal rise with the common value of B for all hadronic scatterings to reduce the number of adjustable parameters. The coefficient B is suggested to be universal in the arguments of color glass condensate (CGC) of QCD. There has been, however, no rigorous proof yet based only on QCD. We attempt to investigate the values of B for πxxxp, Kxxxp and p¯p, pp scatterings respectively through the search for the simultaneous best fit to the experimental σtot and ρ ratios at high energies. The σtot at the resonance and intermediate energy regions has also been exploited as a duality constraint based on the special form of finite-energy sum rule (FESR). We estimate the values of B individually for πxxxp, Kxxxp and p¯p, pp scatterings without using the universality hypothesis. It turs out that the values of B are mutually consistent within one standard deviation, and the universal rise of hadronic total cross sections is strongly suggested. It has to be stressed that we cannot obtain such a definite conclusion without the duality constraint.
Effect of Carbon Inclusion on Microstructure of Electrodeposited Au-Ni Alloy Films
Authors: Inoue Takahiro , Sato Kazuo , Yokoshima Tokihiko , Sugiyama Atsushi , Okinaka Yutaka , Osaka Tetsuya
Published: April 2011

The microstructure of electrodeposited nano-crystalline Au-Ni film was investigated by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning transmission electron microscopy (STEM). Carbon was found to be included in the deposit, and the state of bonding and dispersion of the carbon and its effect on the microstructure of Au-Ni film were studied. Nano-crystalline films were found to be composed of Au-rich crystalline phase and Ni-rich phase, and the latter consisted of crystalline and amorphous phases. The amorphous phase contained a large number of carbon particles measuring 5–20 nm. TEM and STEM examinations showed that the large carbon particles possess a graphite-like structure with some of the particles being arranged in arrays. Mechanism of the carbon inclusion was discussed based on the results of XRD and the composition analysis of Au-free Ni film electrodeposited from a cyanide-containing bath. These results showed that carbon is co-deposited with Ni as nickel carbide and also as carbon particles. It is concluded that the inclusion of carbon and the coexistence of Au and Ni are the conditions necessary for the formation of amorphous structure of the electrodeposited Au-Ni alloy film.