bluuebunny/crossref_metadata_2025 huggingface dataset:
One Explanation for Two-Times Running Speed Response Due to Misalignment in Rotors Connected by Flexible Couplings
Authors: Avendano Raul D. , Childs Dara W.
Published: May 2013

Misalignment in turbomachinery is commonly thought to produce two-times running-speed (2N) response. The source of 2N vibration response was investigated, starting with the development of finite-element models for three flexible disk-pack couplings (four-bolt, six-bolt, and eight-bolt couplings). Parallel and angular misalignments were analyzed. The resultant lateral stiffness terms had 1N, 2N, and 3N harmonic components versus the shaft rotation angle. The four-bolt coupling had large 1N stiffness components under angular and parallel misalignment. The six-bolt coupling had only a 1N reaction component under angular misalignment, while parallel misalignment showed a strong 2N reaction component, larger than either the 1N or 3N components. Under angular misalignment, the eight-bolt model produced large 1N reaction components. Under parallel misalignment, it produced 1N, 2N, and 3N components that were similar in magnitude. All the couplings behaved linearly in the range studied. Some experts attribute observed 2N response to nonlinear bearing forces produced by bearings at high unit loads. Static tests for a five-pad tilting-pad journal bearing with unit loads up to 34.5 bars produced small 2N motion components that did not grow with increasing unit load. A Jeffcott-rotor model with shaft stiffness orthotropy and a fixed-direction side load predicts that 2N response depends on three related factors: (1) the degree of orthotropy (the 1N stiffness variation magnitude), (2) the magnitude of the side load, and (3) the relative ratio of running speed to rotor first natural frequency, (ω/ωn). The 2N response magnitude is largest when ω is close to ωn/2. The side load is required to create 2N response due to shaft stiffness orthotropy. Misaligned couplings create precisely the same (very old) physical model as a two-pole turbogenerator rotor with a gravity side load (gravity critical speed). The response of a two-rotor/coupling system with parallel and angular misalignment was simulated using a time-transient code. When the frequency ratio was 0.5, the system response with the four-bolt and six-bolt coupling had a synchronous 1N component as well as a significant 2N component. Parallel misalignment at a coupling produces stiffness orthotropy and a fixed-direction side load. For ranges of running speed near ωn/2, these two elements can combine to produce 2N response.
Slow-Roll of 40-MW Condensing-Extraction Steam Turbines in a 420-MW Cogeneration Plant
Authors: Ingistov Steve , Milos Michael , Bhargava Rakesh K.
Published: May 2013

This paper describes efforts required to operate a cogeneration facility's extraction-condensing steam turbine generators with flexible rotor design on a slow-roll mode of operation (also called true stand-by). Slow-roll mode of operation became necessary due to changing steam demand from the host refinery, resulting in decreased performance of the steam turbine generators and their associated economic losses. Design modifications implemented to achieve slow-roll of steam turbine generators without affecting reliability and availability of the entire cogeneration facility are discussed in this paper. Successful implementation of the design modifications was demonstrated via extensive field testing on two steam turbine generator units during the summer of 2011. A simple life cycle economic analysis shows the payback period for the project is approximately seven months.
Nonlinear Phenomena in Thermoacoustic Systems With Premixed Flames
Authors: Kashinath Karthik , Hemchandra Santosh , Juniper Matthew P.
Published: May 2013

Nonlinear analysis of thermoacoustic instability is essential for the prediction of the frequencies, amplitudes, and stability of limit cycles. Limit cycles in thermoacoustic systems are reached when the energy input from driving processes and energy losses from damping processes balance each other over a cycle of the oscillation. In this paper, an integral relation for the rate of change of energy of a thermoacoustic system is derived. This relation is analogous to the well-known Rayleigh criterion in thermoacoustics, however, it can be used to calculate the amplitudes of limit cycles and their stability. The relation is applied to a thermoacoustic system of a ducted slot-stabilized 2-D premixed flame. The flame is modeled using a nonlinear kinematic model based on the G-equation, while the acoustics of planar waves in the tube are governed by linearized momentum and energy equations. Using open-loop forced simulations, the flame describing function (FDF) is calculated. The gain and phase information from the FDF is used with the integral relation to construct a cyclic integral rate of change of energy (CIRCE) diagram that indicates the amplitude and stability of limit cycles. This diagram is also used to identify the types of bifurcation the system exhibits and to find the minimum amplitude of excitation needed to reach a stable limit cycle from another linearly stable state for single-mode thermoacoustic systems. Furthermore, this diagram shows precisely how the choice of velocity model and the amplitude-dependence of the gain and the phase of the FDF influence the nonlinear dynamics of the system. Time domain simulations of the coupled thermoacoustic system are performed with a Galerkin discretization for acoustic pressure and velocity. Limit cycle calculations using a single mode, along with twenty modes, are compared against predictions from the CIRCE diagram. For the single mode system, the time domain calculations agree well with the frequency domain predictions. The heat release rate is highly nonlinear but, because there is only a single acoustic mode, this does not affect the limit cycle amplitude. For the twenty-mode system, however, the higher harmonics of the heat release rate and acoustic velocity interact, resulting in a larger limit cycle amplitude. Multimode simulations show that, in some situations, the contribution from higher harmonics to the nonlinear dynamics can be significant and must be considered for an accurate and comprehensive analysis of thermoacoustic systems.
Fabrication of organic interfacial layers by molecular layer deposition: Present status and future opportunities
Authors: Zhou Han , Bent Stacey F.
Published: May 2013

To keep pace with the miniaturization of next generation devices in applications such as electronics, biotechnology, and energy, their constituent polymer thin films must meet challenging requirements such as providing simultaneously ultrathin and conformal coatings. Traditional polymer deposition methods may not be suitable, and as a result, new fabrication methods are needed. Molecular layer deposition (MLD), as an analog to atomic layer deposition, provides precise control over many polymer film properties, such as thickness, composition, morphology, and conformality. Hence, MLD can be a powerful and novel method for fabrication of polymer films. This review article introduces the variety of polymer films that have been developed using MLD together with important film growth characteristics and properties. Examples of MLD polymer applications are provided as well. Finally, challenges and outlooks of the MLD technique are discussed.
Effect of lateral tip stiffness on atomic-resolution force field spectroscopy
Authors: Uluutku Berkin , Baykara Mehmet Z.
Published: May 2013

Atomic force microscopy is being increasingly used to measure atomic-resolution force fields on sample surfaces, making correct interpretation of resulting data critically important. In addition to asymmetry, elastic deformations undergone by the microscope tip are thought to affect measurements. In this study, simple analytical potentials and a model tip apex were used to theoretically analyze how lateral tip stiffness affects force spectroscopy on the surface of NaCl(001). The results suggest that lateral deformations experienced by the tip lead to certain distortions in measured force spectra, the degree of which depends on lateral tip stiffness.
Reference dosimetry at the Australian Synchrotron's imaging and medical beamline using free‐air ionization chamber measurements and theoretical predictions of air kerma rate and half value layer
Authors: Crosbie Jeffrey C. , Rogers Peter A. W. , Stevenson Andrew W. , Hall Christopher J. , Lye Jessica E. , Nordström Terese , Midgley Stewart M. , Lewis Robert A.
Published: May 2013

Purpose:

Novel, preclinical radiotherapy modalities are being developed at synchrotrons around the world, most notably stereotactic synchrotron radiation therapy and microbeam radiotherapy at the European Synchrotron Radiation Facility in Grenoble, France. The imaging and medical beamline (IMBL) at the Australian Synchrotron has recently become available for preclinical radiotherapy and imaging research with clinical trials, a distinct possibility in the coming years. The aim of this present study was to accurately characterize the synchrotron‐generated x‐ray beam for the purposes of air kerma‐based absolute dosimetry.

Methods:

The authors used a theoretical model of the energy spectrum from the wiggler source and validated this model by comparing the transmission through copper absorbers (0.1–3.0 mm) against real measurements conducted at the beamline. The authors used a low energy free air ionization chamber (LEFAC) from the Australian Radiation Protection and Nuclear Safety Agency and a commercially available free air chamber (ADC‐105) for the measurements. The dimensions of these two chambers are different from one another requiring careful consideration of correction factors.

Results:

Measured and calculated half value layer (HVL) and air kerma rates differed by less than 3% for the LEFAC when the ion chamber readings were corrected for electron energy loss and ion recombination. The agreement between measured and predicted air kerma rates was less satisfactory for the ADC‐105 chamber, however. The LEFAC and ADC measurements produced a first half value layer of 0.405 ± 0.015 and 0.412 ± 0.016 mm Cu, respectively, compared to the theoretical prediction of 0.427 ± 0.012 mm Cu. The theoretical model based upon a spectrum calculator derived a mean beam energy of 61.4 keV with a first half value layer of approximately 30 mm in water.

Conclusions:

The authors showed in this study their ability to verify the predicted air kerma rate and x‐ray attenuation curve on the IMBL using a simple experimental method, namely, HVL measurements. The HVL measurements strongly supports the x‐ray beam spectrum, which in turn has a profound effect on x‐ray dosimetry.
Using a mobile phone acceleration sensor in physics experiments on free and damped harmonic oscillations
Authors: Carlos Castro-Palacio Juan , Velázquez-Abad Luisberis , Giménez Marcos H. , Monsoriu Juan A.
Published: May 2013

We have used a mobile phone acceleration sensor, and the Accelerometer Monitor application for Android, to collect data in physics experiments on free and damped oscillations. Results for the period, frequency, spring constant, and damping constant agree very well with measurements obtained by other methods. These widely available sensors are likely to find increased use in instructional laboratories.
Photonic Rutherford scattering: A classical and quantum mechanical analogy in ray and wave optics
Authors: Selmke Markus , Cichos Frank
Published: May 2013

Using Fermat's least-optical-path principle, the family of ray trajectories through a special (but common) type of a gradient refractive index lens n(r)=n0+ΔnR/r is solved analytically. The solution gives a ray equation r(ϕ) that is closely related to Rutherford scattering trajectories; we therefore refer to this refraction process as “photonic Rutherford scattering.” It is shown that not only do the classical limits correspond but also the wave-mechanical pictures coincide—the time-independent Schrödingier equation and the Helmholtz equation permit the same mapping between the scattering of massive particles and optical scalar waves. Scattering of narrow beams of light finally recovers the classical trajectories. The analysis suggests that photothermal single-particle microscopy measures photonic Rutherford scattering in specific limits and allows for an individual single-scatterer probing. A macroscopic experiment is demonstrated to directly measure the scattering angle to impact parameter relation, which is otherwise accessible only indirectly in Rutherford-scattering experiments.
An introduction to the spectrum, symmetries, and dynamics of spin-1/2 Heisenberg chains
Authors: Joel Kira , Kollmar Davida , Santos Lea F.
Published: May 2013

Quantum spin chains are prototype quantum many-body systems that are employed in the description of various complex physical phenomena. We provide an introduction to this subject by focusing on the time evolution of a Heisenberg spin-1/2 chain and interpreting the results based on the analysis of the eigenvalues, eigenstates, and symmetries of the system. We make available online all computer codes used to obtain our data.
Optimal pacing for running 400- and 800-m track races
Authors: Reardon James
Published: May 2013

We present a toy model of anaerobic glycolysis that utilizes appropriate physiological and mathematical consideration while remaining useful to the athlete. The toy model produces an optimal pacing strategy for 400-m and 800-m races that is analytically calculated via the Euler-Lagrange equation. The calculation of the optimum v(t) is presented in detail, with an emphasis on intuitive arguments in order to serve as a bridge between the basic techniques presented in undergraduate physics textbooks and the more advanced techniques of control theory. Observed pacing strategies in 400-m and 800-m world-record races are found to be well-fit by the toy model, which allows us to draw a new physiological interpretation for the advantages of common weight-training practices.
MEASUREMENT-INDUCED NONLOCALITY OVER TWO-SIDED PROJECTIVE MEASUREMENTS
Authors: GUO YU
Published: May 2013

Measurement-induced nonlocality (MIN), introduced by Luo and Fu [Phys. Rev. Lett.106, 120401 (2011)], is a kind of quantum correlation which is different from entanglement and quantum discord (QD). MIN is defined over one-sided projective measurements. In this paper, we introduce a MIN over two-sided projective measurements. The nullity of this two-sided MIN is characterized, a formula for calculating two-sided MIN for pure states is proposed, and a lower bound of (two-sided) MIN for maximally entangled mixed states is given. In addition, we find that (two-sided) MIN is not continuous. Both finite- and infinite-dimensional cases are considered.
FRACTIONAL WINDINGS OF THE SPINOR CONDENSATES ON A RING
Authors: LIU YONG-KAI , YANG SHI-JIE
Published: May 2013

We study the uniform solutions to the one-dimensional (1D) spinor Bose–Einstein condensates on a ring. These states explicitly display the associated motion of the super-current and the spin rotation, which give rise to fractional winding numbers according to the various compositions of the hyperfine states. It simultaneously yields a fractional factor to the global phase due to the spin-gauge symmetry. All fractional windings can be denoted as nk/(m+n), with nk<m+n<2F, for arbitrary spin-F Bose–Einstein condensation (BEC). Our method can be applied to explore the fractional vortices by identifying the ring as the boundary of two-dimensional (2D) spinor condensates.
FCS OF SUPERCONDUCTING TUNNEL JUNCTIONS IN NONEQUILIBRIUM
Authors: SOLLER H.
Published: May 2013

We analyze the full counting statistics (FCS) of a superconducting junction in nonequilibrium in the limit of small interface transparency. In this limit we treat both supercurrent and multiple Andreev reflections on equal footing and show how to generalize previous results for both phenomena. Furthermore, we also allow for different gaps of both superconductors and investigate the intermediate regime which allows to make contact with previous results on normal-superconductor heterostructures. We also compare our predictions in this regime to experimental data.
GABA UPTAKE BY GAT1 MODULATES LONG-TERM OPTICAL CHANGES FOLLOWING ELECTRICAL STIMULATION OF THE PITUITARY GLAND NEUROINTERMEDIATE LOBE
Authors: KOSTERIN P. , OBAID A. L. , SALZBERG B. M.
Published: May 2013

Intrinsic optical changes that follow infundibular stalk stimulation of the neurointermediate lobe of the mouse pituitary gland exhibit three different phases that reflect three distinct physiological events. The first (E-wave) is the rapid light-scattering increase that is associated with a nerve terminal volume increase (mechanical spike), and that accompanies excitation of the neurohypophysial terminals by the invading action potential; the second (S-wave) is the slower light-scattering decrease that is tightly correlated with the secretion of the peptide hormones oxytocin and arginine vasopressin, and the third is the long-duration response (R-wave) that reflects cell volume changes in the pars intermedia. We have studied the E-wave and the S-wave in earlier publications. The R-wave, considered here, is sensitive to chloride replacement as well as to blockade of chloride channels. By blocking GABAAreceptors (which are ligand-gated chloride channels) with pharmacological agents, and by applying GABA directly into the bathing solution, or evoking its release from GABAergic inputs, we have demonstrated that this long-duration optical response is sensitive to chloride movements and reflects GABA-induced changes in the intrinsic optical properties of the pars intermedia. The full time-course of this optical response takes minutes and, therefore, has to embody some other process (or processes) related to the restoration of resting physiological chloride concentrations, following the opening and closing of GABAA-receptor channels. Here we demonstrate that the shape of the R-wave, the long-lasting light-scattering signal, is indeed affected by the activity of GAT1, one of the sodium- and chloride-dependent GABA transporters.
THE CHEMISTRY AND BIOLOGY OF GOLD NANOPARTICLE-MEDIATED PHOTOTHERMAL THERAPY: PROMISES AND CHALLENGES
Authors: CABRAL RITA M. , BAPTISTA PEDRO V.
Published: May 2013

Under laser radiation, cells labeled with gold nanoparticles (AuNPs) are believed to suffer thermal damage due to the transfer of the absorbed light from the AuNPs to the cells. This process, which involves complex mechanisms such as the rapid electron–phonon decay in the AuNPs , followed by phonon–phonon relaxation, culminates in the localized heating of both the AuNPs and the cells, setting the rational for the use of these nanostructures, under laser light, in cancer photothermal therapy (PTT). Here, we discuss the chemical and biological aspects of this promising new therapeutic approach, including the advantages over conventional cancer therapies and the challenges that scientists still need to overcome to progress toward translation research.
Severe Diltiazem Poisoning Treated with Hyperinsulinaemia-Euglycaemia and Lipid Emulsion
Authors: Monteiro Nadine , Silvestre Joana , Gonçalves-Pereira João , Tapadinhas Camila , Mendes Vitor , Póvoa Pedro
Published: May 2013

Introduction. Calcium channel blockers (CCBs) drugs are widely used in the treatment of cardiovascular diseases. CCB poisoning is associated with significant cardiovascular toxicity and is potentially fatal. Currently, there is no specific antidote and the treatment of CCB poisoning is supportive; however, this supportive therapy is often insufficient. We present a clinical case of severe diltiazem poisoning and the therapeutic approaches that were used.Case Report. A 55-year-old male was admitted to the intensive care unit (ICU) after voluntary multiple drug intake, including extended release diltiazem (7200 mg). The patient developed symptoms of refractory shock to conventional therapy and required mechanical ventilation, a temporary pacemaker, and renal replacement therapy. Approximately 17 hours after drug intake, hyperinsulinaemia-euglycaemia with lipid emulsion therapy was initiated, followed by progressive haemodynamic recovery within approximately 30 minutes. The toxicological serum analysis 12 h after drug ingestion revealed a diltiazem serum level of 4778 ng/mL (therapeutic level: 40–200 ng/mL).Conclusions. This case report supports the therapeutic efficacy of hyperinsulinaemia-euglycaemia and lipid emulsion in the treatment of severe diltiazem poisoning.
Temperature Dependence of Ascending Bubble-Driven Flow Patterns Found in Champagne Glasses as Determined through Numerical Modeling
Authors: Beaumont Fabien , Popa Catalin , Liger-Belair Gérard , Polidori Guillaume
Published: May 2013

A numerical modeling of bubble-driven flow patterns in a glass of champagne has been carried out for three champagne temperatures, by using the finite-volume method by CFD (computational fluid dynamics). In order to define source terms for flow regime and to reproduce accurately the bubble nucleation process responsible for champagne effervescence, specific subroutines for the gaseous phase have been added to the main numerical model. These subroutines allow the modeling of bubbles behavior based on semiempirical formulas relating to bubble diameter, mass transfer, velocity, and drag force. Both ascending bubble dynamics and bubble-driven flow patterns dynamics were examined, respectively, 60 s, 180 s, and 300 s after pouring champagne into the glass. Details and development of the various steps of modeling are presented in this paper, showing that the bubble-driven flow patterns velocities of the liquid phase significantly vary with the champagne temperature.
Amiodarone Hepatotoxicity with Absent Phospholipidosis and Steatosis: A Case Report and Review of Amiodarone Toxicity in Various Organs
Authors: Cimic Adela , Sirintrapun Joseph
Published: May 2013

We present the first description of amiodarone toxicity in the liver without phospholipidosis or steatosis. In doing so, we will review the various effects of amiodarone toxicity in various organs. The patient is a young adult who had cardiac reconstruction as a child for transposition of the great vessels. A needle biopsy was taken due to elevated liver enzymes. Her ALT was 188 U/L (5–50) and AST 162 U/L (5–50). Alkaline phosphatase, total bilirubin, protein, and albumin were within normal limits. A serologic panel for viral hepatitis was negative. Antinuclear antibodies were positive at 260; however, anti-smooth muscle antibody and anti-mitochondrial antibody were negative. A protein electrophoresis showed a slightly elevated beta globulin 2 level of 0.5. Quantitative immunoglobulin levels were within normal limits except for a slightly elevated IgA 409 mg/dL (60–350). Liver ultrasound was unremarkable. The clinical differential was broad and included hepatic congestion along with autoimmune hepatitis. Sections showed only ballooned hepatocytes with Mallory-Denk bodies and perisinusoidal fibrosis. Arrival to the diagnosis was possible only after careful review of the patient’s medications. After discontinuation of amiodarone, the patient’s liver enzymes returned to normal levels.
New Host Record forCamponotophilus delvarei(Hymenoptera: Eurytomidae), a Parasitoid of Microdontine Larvae (Diptera: Syrphidae), Associated with the AntCamponotussp. aff.textor
Authors: Pérez-Lachaud Gabriela , Gates Michael W. , Lachaud Jean-Paul
Published: May 2013

Microdontine syrphid flies are obligate social parasites of ants. Larvae prey on ant brood whereas adults live outside the nests. Knowledge of their interaction with their host is often scarce, as it is information about their natural enemies. Here we report the first case of parasitism of a species of microdontine fly by a myrmecophilous eurytomid wasp. This is also the first host record forCamponotophilus delvareiGates, a recently described parasitic wasp discovered in Chiapas, Mexico, within the nests of the weaver ant,Camponotussp. aff.textorForel. Eleven pupal cases of a microdontine fly were found within a single nest of this ant, five of them being parasitized. Five adultC. delvareifemales were reared from a puparium and 29 female and 2 male pupae were obtained from another one. The eurytomid is a gregarious, primary ectoparasitoid of larvae and pupae of Microdontinae, its immature stages developing within the protective puparium of the fly. The species is synovigenic. Adult females likely locate and parasitize their hosts within the ant nest. As some species of Microdontinae are considered endangered, their parasitoids are likewise threatened and in need of accurate and urgent surveys in the future.
In VitroMorphological Assessment of Apoptosis Induced by Antiproliferative Constituents from the Rhizomes ofCurcuma zedoaria
Authors: Syed Abdul Rahman Syarifah Nur , Abdul Wahab Norhanom , Abd Malek Sri Nurestri
Published: May 2013

Bioassay-guided isolation of the active hexane fractions ofCurcuma zedoarialed to the identification of five pure compounds, namely, curzerenone (1), neocurdione (2), curdione (3), alismol (4), and zederone (5) and a mixture of sterols, namely, campesterol (6), stigmasterol (7), andβ-sitosterol (8). Alismol has never been reported to be present inCurcuma zedoaria. All isolated compounds except (3) were evaluated for their cytotoxic activity against MCF-7, Ca Ski, and HCT-116 cancer cell lines and noncancer human fibroblast cell line (MRC-5) using neutral red cytotoxicity assay. Curzerenone and alismol significantly inhibited cell proliferation in human cancer cell lines MCF-7, Ca Ski, and HCT-116 in a dose-dependent manner. Cytological observations by an inverted phase contrast microscope and Hoechst 33342/PI dual-staining assay showed typical apoptotic morphology of cancer cells upon treatment with curzerenone and alismol. Both compounds induce apoptosis through the activation of caspase-3. It can thus be suggested that curzerenone and alismol are modulated by apoptosis via caspase-3 signalling pathway. The findings of the present study support the use ofCurcuma zedoariarhizomes in traditional medicine for the treatment of cancer-related diseases. Thus, two naturally occurring sesquiterpenoids, curzerenone and alismol, hold great promise for use in chemopreventive and chemotherapeutic strategies.
Distributed Cognitive Radio Spectrum Access with Imperfect Sensing Using CTMC
Authors: Muthumeenakshi K. , Radha S.
Published: May 2013

Cognitive radio (CR) has become an efficient approach for the utilization of scarce spectrum by enabling spectrum access in an opportunistic manner. With increasing wireless network service providers, users, and applications, it is indispensable to optimize usage of even parts of the spectrum that are licensed. Dynamic spectrum access (DSA) is an approach which facilitates the opportunistic use of licensed spectra, when they are idle. In this paper, a primary prioritized distributed DSA algorithm using continuous-time Markov chain (CTMC) model is proposed. In a distributed scheme, each secondary user needs to be aware of the statistics—arrival and service rates—of the other secondary users to optimize the throughput while maintaining fairness. A heuristics-based approach is formulated making use of the estimated spectrum idle probability and the interference each user experiences to iteratively update user statistics. This framework is also extended to incorporate the effects of imperfect spectrum sensing in the form of misdetection and false alarms. Simulation results show that the proposed algorithm attains an overall throughput that is better than CSMA when the primary user spectrum utilization is around 45%. The degradation in throughput caused by imperfect sensing over perfect sensing is also analyzed.
Bullying, Victimization, School Performance, and Mother-Child Relationship Quality: Direct and Transactional Associations
Authors: Fanti Kostas A. , Georgiou Stelios N.
Published: May 2013

The current investigation examines longitudinal differences between bullies, victims, and bully victims in terms of the quality of their relationship with their parents and school performance. We also investigate the transactional association between the quality of the parent-child relationship and bullying behavior, after taking into account the longitudinal association among bullying, victimization, and school performance. The sample consisted of 895 mothers and their children who participated in the NICHD Study of Early Child Care. According to the findings, children in the cooccurring bully victim group were at higher risk to experience continuous conflict with their mothers and to perform worse academically. The findings also offer support for the hypothesized transactional association between bullying and parent-child conflict and closeness. Further, a positive longitudinal transactional association between victimization and parent-child closeness was identified. Finally, school performance was positively related to victimization but was unrelated to bullying behavior.
Approximate Controllability of Fractional Integrodifferential Evolution Equations
Authors: Ganesh R. , Sakthivel R. , Mahmudov N. I. , Anthoni S. M.
Published: May 2013

This paper addresses the issue of approximate controllability for a class of control system which is represented by nonlinear fractional integrodifferential equations with nonlocal conditions. By using semigroup theory,p-mean continuity and fractional calculations, a set of sufficient conditions, are formulated and proved for the nonlinear fractional control systems. More precisely, the results are established under the assumption that the corresponding linear system is approximately controllable and functions satisfy non-Lipschitz conditions. The results generalize and improve some known results.
Fixed Point Theory of Weak Contractions in Partially Ordered Metric Spaces
Authors: Chen Chi-Ming , Lee Jin-Chirng , Chen Chao-Hung
Published: May 2013

We prove two new fixed point theorems in the framework of partially ordered metric spaces. Our results generalize and improve many recent fixed point theorems in the literature.
Effect of Cassava Flour Characteristics on Properties of Cassava-Wheat-Maize Composite Bread Types
Authors: Eduardo Maria , Svanberg Ulf , Oliveira Jorge , Ahrné Lilia
Published: May 2013

Replacement of wheat flour by other kinds of flour in bread making is economically important in South East Africa as wheat is mainly an imported commodity. Cassava is widely available in the region, but bread quality is impaired when large amounts of cassava are used in the bread formulation. Effect of differently processed cassavas (sun-dried, roasted and fermented) on composite cassava-wheat-maize bread quality containing cassava levels from 20 to 40% (w/w) was evaluated in combination with high-methylated pectin (HM-pectin) added at levels of 1 to 3% (w/w) according to a full factorial design. Addition of pectin to cassava flour made it possible to bake bread with acceptable bread quality even at concentration as high as 40%. In addition to cassava concentration, the type of cassava flour had the biggest effect on bread quality. With high level of cassava, bread with roasted cassava had a higher volume compared with sun-dried and fermented. The pectin level had a significant effect on improving the volume in high level roasted cassava bread. Crumb firmness similar to wheat bread could be obtained with sun-dried and roasted cassava flours. Roasted cassava bread was the only bread with crust colour similar to wheat bread.
The Study of Scene Classification in the Multisensor Remote Sensing Image Fusion
Authors: Li Ji , Liu Zhen
Published: May 2013

We propose a scene classification method for speeding up the multisensor remote sensing image fusion by using the singular value decomposition of quaternion matrix and the kernel principal component analysis (KPCA) to extract features. At first, images are segmented to patches by a regular grid, and for each patch, we extract color features by using quaternion singular value decomposition (QSVD) method, and the grey features are extracted by Gabor filter and then by using orientation histogram to describe the grey information. After that, we combine the color features and the orientation histogram together with the same weight to obtain the descriptor for each patch. All the patch descriptors are clustered to get visual words for each category. Then we apply KPCA to the visual words to get the subspaces of the category. The descriptors of a test image then are projected to the subspaces of all categories to get the projection length to all categories for the test image. Finally, support vector machine (SVM) with linear kernel function is used to get the scene classification performance. We experiment with three classification situations on OT8 dataset and compare our method with the typical scene classification method, probabilistic latent semantic analysis (pLSA), and the results confirm the feasibility of our method.
Preparation of Smooth Surface TiO2 Photoanode for High Energy Conversion Efficiency in Dye‐Sensitized Solar Cells
Authors: Kathirvel Sasipriya , Chen Huei-Siou , Su Chaochin , Wang Hsiue-Hsyan , Li Chung-Yen , Li Wen-Ren
Published: May 2013

Dye‐sensitized solar cells (DSSCs) based on a TiO2 photoanode have been considered as an alternative source in the field of renewable energy resources. In DSSCs, photoanode plays a key role to achieve excellent photo‐to‐electric conversion efficiency. The surface morphology, surface area, TiO2 crystal phase, and the dispersion of TiO2 nanoparticles are the most important factors influencing the properties of a photoanode. The smooth TiO2 surface morphology of the photoanode indicates closely packed arrangement of TiO2 particles which enhance the light harvesting efficiency of the cell. In this paper, a smooth TiO2 photoanode has been successfully prepared using a well‐dispersed anatase TiO2 nanosol via a simple hydrothermal process. The above TiO2 photoanode was then compared with the photoanode made from commercial TiO2 nanoparticle pastes. The morphological and structural analyses of both the aforementioned photoanodes were comprehensively characterized by scanning electron microscopy and X‐ray diffraction analysis. The DSSC fabricated by using a‐TiO2 nanosol‐based photoelectrode exhibited an overall light conversion efficiency of 7.20% and a short‐circuit current density of 13.34 mA cm−2, which was significantly higher than those of the DSSCs with the TiO2 nanoparticles‐based electrodes.
Classification of Prolapsed Mitral Valve versus Healthy Heart from Phonocardiograms by Multifractal Analysis
Authors: Gavrovska Ana , Zajić Goran , Reljin Irini , Reljin Branimir
Published: May 2013

Phonocardiography has shown a great potential for developing low-cost computer-aided diagnosis systems for cardiovascular monitoring. So far, most of the work reported regarding cardiosignal analysis using multifractals is oriented towards heartbeat dynamics. This paper represents a step towards automatic detection of one of the most common pathological syndromes, so-called mitral valve prolapse (MVP), using phonocardiograms and multifractal analysis. Subtle features characteristic for MVP in phonocardiograms may be difficult to detect. The approach for revealing such features should be locally based rather than globally based. Nevertheless, if their appearances are specific and frequent, they can affect a multifractal spectrum. This has been the case in our experiment with the click syndrome. Totally, 117 pediatric phonocardiographic recordings (PCGs), 8 seconds long each, obtained from 117 patients were used for PMV automatic detection. We propose a two-step algorithm to distinguish PCGs that belong to children with healthy hearts and children with prolapsed mitral valves (PMVs). Obtained results show high accuracy of the method. We achieved 96.91% accuracy on the dataset (97 recordings). Additionally, 90% accuracy is achieved for the evaluation dataset (20 recordings). Content of the datasets is confirmed by the echocardiographic screening.
An Efficient Biometric Authentication Protocol for Wireless Sensor Networks
Authors: Althobaiti Ohood , Al-Rodhaan Mznah , Al-Dhelaan Abdullah
Published: May 2013

Wireless sensor networks (WSNs) are spreading rapidly due to their flexibility to communicate which demands a secure environment. The most important requirements of WSN security are confidentiality, authentication, and integrity. User authentication is necessary for legitimate access control in WSNs. Sensors have limited processing power, bandwidth, memory, and limited communication abilities. Significantly, the system must produce an authentication method to confirme if the user is legal or not. In this paper, we present a solution based on biometric and adapt it for a WSN environment. The proposed protocol involves simple operations and light computations. The main advantage of the proposed protocol is using the user's iris to regenerate the user's key on-the-fly every time the user wants be authenticated which dramatically enhances security aspects in WSNs. The key used in this protocol is stronger than passwords and shorter than biometric data, which balances between security and performance. Our protocol uses much light computations and simple operations in both homogenous and heterogeneous environments; therefore, it is suitable to the WSNs.
A Linear Time Complexity of Breadth-First Search UsingPSystem with Membrane Division
Authors: Salehi Einallah , Shamsuddin Siti Mariyam , Nemati Kourosh
Published: May 2013

One of the known methods for solving the problems with exponential time complexity such as NP-complete problems is using the brute force algorithms. Recently, a new parallel computational framework called Membrane Computing is introduced which can be applied in brute force algorithms. The usual way to find a solution for the problems with exponential time complexity with Membrane Computing techniques is byPSystem with active membrane using division rule. It makes an exponential workspace and solves the problems with exponential complexity in a polynomial (even linear) time. On the other hand, searching is currently one of the most used methods for finding solution for problems in real life, that the blind search algorithms are accurate, but their time complexity is exponential such as breadth-first search (BFS) algorithm. In this paper, we proposed a new approach for implementation of BFS by usingPsystem with division rule technique for first time. The theorem shows time complexity of BSF in this framework on randomly binary trees reduced fromO(2d)toO(d).
Synergistic Effect of Lupenone and Caryophyllene Oxide againstTrypanosoma cruzi
Authors: Polanco-Hernández Glendy , Escalante-Erosa Fabiola , García-Sosa Karlina , Rosado María E. , Guzmán-Marín Eugenia , Acosta-Viana Karla Y. , Giménez-Turba Alberto , Salamanca Efraín , Peña-Rodríguez Luis M.
Published: May 2013

Thein vitrotrypanocidal activity of a 1 : 4 mixture of lupenone and caryophyllene oxide confirmed a synergistic effect of the terpenoids against epimastigotes forms ofT. cruzi(IC50=10.4 μg/mL, FIC = 0.46). In addition, testing of the terpenoid mixture for its capacity to reduce the number of amastigote nests in cardiac tissue and skeletal muscle of infected mice showed a reduction of more than 80% at a dose level of 20.8 mg·kg−1·day−1.
Conversion to Sirolimus Therapy in Kidney Transplant Recipients with New Onset Diabetes Mellitus after Transplantation
Authors: Veroux Massimiliano , Tallarita Tiziano , Corona Daniela , Sinagra Nunziata , Giaquinta Alessia , Zerbo Domenico , Guerrieri Carmela , D'Assoro Antonino , Cimino Sebastiano , Veroux Pierfrancesco
Published: May 2013

New-onset diabetes mellitus after transplantation (NODAT) may complicate 2–50% of kidney transplantation, and it is associated with reduced graft and patient survivals. In this retrospective study, we applied a conversion protocol to sirolimus in a cohort of kidney transplant recipients with NODAT. Among 344 kidney transplant recipients, 29 patients developed a NODAT (6.6%) and continued with a reduced dose of calcineurin inhibitors (CNI) (8 patients, Group A) or were converted to sirolimus (SIR) (21 patients, Group B). NODAT resolved in 37.5% and in 80% patients in Group A and Group B, respectively. In Group A, patient and graft survivals were 100% and 75%, respectively, not significantly different from Group B (83.4% and 68%, resp.,P=0.847). Graft function improved after conversion to sirolimus therapy: serum creatinine was 1.8 ± 0.7 mg/dL at the time of conversion and 1.6 ± 0.4 mg/dL five years after conversion to sirolimus therapy (P<0.05), while in the group of patients remaining with a reduced dose of CNI, serum creatinine was 1.7 ± 0.6 mg/dL at the time of conversion and 1.65 ± 0.6 mg/dL at five-year followup (P=0.732). This study demonstrated that the conversion from CNI to SIR in patients could improve significantly the metabolic parameters of patients with NODAT, without increasing the risk of acute graft rejection.
Rolling Bearing Fault Detection Based on the Teager Energy Operator and Elman Neural Network
Authors: Liu Hongmei , Wang Jing , Lu Chen
Published: May 2013

This paper presents an approach to bearing fault diagnosis based on the Teager energy operator (TEO) and Elman neural network. The TEO can estimate the total mechanical energy required to generate signals, thereby resulting in good time resolution and self-adaptability to transient signals. These attributes reflect the advantage of detecting signal impact characteristics. To detect the impact characteristics of the vibration signals of bearing faults, we used the TEO to extract the cyclical impact caused by bearing failure and applied the wavelet packet to reduce the noise of the Teager energy signal. This approach also enabled the extraction of bearing fault feature frequencies, which were identified using the fast Fourier transform of Teager energy. The feature frequencies of the inner and outer faults, as well as the ratio of resonance frequency band energy to total energy in the Teager spectrum, were extracted as feature vectors. In order to avoid a frequency leak error, the weighted Teager spectrum around the fault frequency was extracted as feature vector. These vectors were then used to train the Elman neural network and improve the robustness of the diagnostic algorithm. Experimental results indicate that the proposed approach effectively detects bearing faults under variable conditions.
Theoretical Vibration Analysis on 600 Wh Energy Storage Flywheel Rotor—Active Magnetic Bearing System
Authors: Liu Jing-na , Ren Zheng-yi , Wu Shan-wei , Tang Yin-long
Published: May 2013

This paper shows a theoretical vibration analysis regarding the controller’s parameters and the gyroscopic effect, based on a simplified rotordynamic model. Combined with 600 Wh energy storage flywheel rotor system mathematical model, the Campbell diagram of the rotor system was obtained by the calculation of the whirl frequency under different parameters of the controller in MATLAB to analyze the effect of the controller parameter on the whirl frequency and to limit the operating speed and acceleration or deceleration of the rotor. The result of the analysis can be used to set the support position of the rotor system, limit the ratio of transverse moment of inertia and the polar moment of inertia, and direct the flywheel prototype future design. The presented simplified rotordynamic model can also be applied to rotating machines.
Periodontal Management of Sturge-Weber Syndrome
Authors: Kalakonda Butchibabu , Pradeep Koppolu , Mishra Ashank , Reddy Krishnanjaneya , Muralikrishna Tupili , Lakshmi Vijaya , Challa Radhika
Published: May 2013

Sturge-Weber syndrome (SWS) is a sporadic disorder and is frequent among the neurocutaneous syndromes specifically with vascular predominance. This syndrome consists of constellation of clinical features like facial nevus, seizures, hemiparesis, intracranial calcifications, and mental retardation. It is characterized by focal port-wine stain, ocular abnormalities (glaucoma), and choroidal hemangioma and leptomeningeal angioma most often involving occipital and parietal lobes. The present paper reports three cases of SWS with oral manifestations and periodontal management, which included thorough scaling and root planing followed by gingivectomy with scalpel and laser in cases 1 and 3 consecutively to treat the gingival enlargement. However, the treatment in case 2 was deferred as the patient was not a candidate for periodontal surgery.
Methods for the Evaluation of Polyphenolic Content in “Uva Di Troia Canosina” Grape and Seeds at the Different Maceration Stages
Authors: Catalano Daria , Fontana Sergio , Roda Gabriella , Dell'Acqua Lucia , La Forgia Flavia , Mustich Giuseppe , Sorrenti Giovanni , Suriano Serafino , Visconti Giacomo Luca , Gambaro Veniero
Published: May 2013

Seeds and skins derived from the small berries of “uva di Troia canosina” grape, a Vitis vinifera variety autochthonous of Apulia region (South Italy), collected at four different stages (“Tesi” 1–4) of the fermentation process were extracted by means of a maceration. The extracts were purified and analyzed, in order to study the influence of fermentation over grape seed and skin polyphenolic content. Seed extraction was performed by a multistep maceration with two solvents: ethanol and acetone, the former giving the best results; moreover, the extracts were purified with pure ethyl acetate in order to enrich their polyphenolic content. On the other hand, skin extraction was achieved by a single-step maceration in methanol and a purification with a brominated synthetic adsorbent resin. The evaluation of the extraction yield and polyphenolic content was carried out by TLC, UV/VIS, and LC/DAD analyses. In the seed extracts, the characteristic polyphenols (catechin, epicatechin, and procyanidin B1 and B2) useful for the development of a nutraceutical product, endowed with antioxidant properties, were present, while no resveratrol was detected in “uva di Troia canosina” grape skin extracts, even in an LC/MS-MS analysis.
Log‐Cubic Method for Generation of Soil Particle Size Distribution Curve
Authors: Shang Songhao
Published: May 2013

Particle size distribution (PSD) is a fundamental physical property of soils. Traditionally, the PSD curve was generated by hand from limited data of particle size analysis, which is subjective and may lead to significant uncertainty in the freehand PSD curve and graphically estimated cumulative particle percentages. To overcome these problems, a log‐cubic method was proposed for the generation of PSD curve based on a monotone piecewise cubic interpolation method. The log‐cubic method and commonly used log‐linear and log‐spline methods were evaluated by the leave‐one‐out cross‐validation method for 394 soil samples extracted from UNSODA database. Mean error and root mean square error of the cross‐validation show that the log‐cubic method outperforms two other methods. What is more important, PSD curve generated by the log‐cubic method meets essential requirements of a PSD curve, that is, passing through all measured data and being both smooth and monotone. The proposed log‐cubic method provides an objective and reliable way to generate a PSD curve from limited soil particle analysis data. This method and the generated PSD curve can be used in the conversion of different soil texture schemes, assessment of grading pattern, and estimation of soil hydraulic parameters and erodibility factor.