bluuebunny/crossref_metadata_2025 huggingface dataset:
A Numerical Investigation of Nanofluids Thermal Behavior in Microchannels Under Laminar Flow Conditions
Authors: Koronaki I. P. , Nitsas M. T. , Vallianos Ch. A.
Published: March 2016

Due to large amounts of heat flux developed in electronic devices, it is essential to propose and investigate effective mechanisms of cooling them. Although microchannels filled with flowing coolant are a geometry often met in such devices, new techniques need to be developed in order to increase their effectiveness. Recent studies on nanofluids, i.e. mixtures of nanometer size particles well-dispersed in a base fluid, have demonstrated their potential for augmenting heat transfer.

In the present work the 2D steady state laminar flow of different nanofluids along a microchannel is examined. It is considered that the microchannel walls receive uniform and constant heat flux. The problem’s modelling has as parameters the volume fraction of nanoparticles ranging from 0 to 5% and Reynolds number varying between 50 and 500. The results of the problem’s numerical solution are used to calculate the heat transfer coefficient, the pressure drop along the microchannel and the destroyed exergy.

It is found that heat transfer is enhanced due to the presence of nanoparticles. On the contrary, pressure drops faster due to nanofluids increased viscosity leading to more pump power needed. Finally, further exergy destruction is observed when nanoparticles volume fraction increases.
Corrosion-Fatigue Structural Integrity Assessment Using a Thermodynamic Entropy Based Damage Approach
Authors: Imanian Anahita , Modarres Mohammad
Published: March 2016

Using fundamentals of irreversible thermodynamics, with specific focus on entropy generation, this paper studies the structural integrity of degraded materials. All damage mechanisms share a common feature namely energy dissipation. Dissipation, as a fundamental measure for irreversibility in a thermodynamic treatment of non-equilibrium processes, is quantified by entropy generation. Based on the theoretical relationship between entropy generation and generalized thermodynamic forces and fluxes, the entropic damage is measured during a corrosion-fatigue degradation experiment. Life estimation of components, which were subject to complex corrosion-fatigue degradation mechanism, was then estimated through a proposed entropic-based prognostic framework. The performance of predictions was evaluated and compared with previous predictions in terms of the influence of additional features on components health assessment.
Advances in Modular Design: Optimizing Mechanical Connections for Hi-Mix, Low-Volume Product Designs
Authors: Lesher Mark , Prendergast Guy , Moras Rafael
Published: March 2016

In a previous study, we analyzed the life cycle cost impacts of component location changes as applied to rolling stock products [1]. Here, we present the results of an analysis that quantifies the costs of changing heavy-duty connection locations in modular fabrication designs. Modules that are fitted together usually include multiple lines of piping, cabling, and other connections, which can be problematic when the design may change due to out-of-tolerance dimensions or design requirements that change prior to installation. Also, design changes after site delivery may require frequent location changes for components that are mounted within modules. Inflexible connections internal to the module or chassis may hinder module-to-module connections in the field, where changes are difficult, hot work is dangerous, and quality of repair is dubious. The aim of this analysis was to evaluate the costs to change various types of pipe connections between modules and the costs to change component locations within modules. In addition to allowing mounting locations to be easily changed between and within modules, adjustable connection points enhance the modularization and customization of products at the lower levels of production associated with the energy, shipbuilding and rolling stock industries.
Work/Precision Tradeoffs in Continuum Models of Biomolecular Electrostatics
Authors: Knepley Matthew G. , Bardhan Jaydeep P.
Published: March 2016

The structure and function of biological molecules are strongly influenced by the water and dissolved ions that surround them. This aqueous solution (solvent) exerts significant electrostatic forces in response to the biomolecule’s ubiquitous atomic charges and polar chemical groups. In this work, we investigate a simple approach to numerical calculation of this model using boundary-integral equation (BIE) methods and boundary-element methods (BEM). Traditional BEM discretizes the protein–solvent boundary into a set of boundary elements, or panels, and the approximate solution is defined as a weighted combination of basis functions with compact support. The resulting BEM matrix then requires integrating singular or near singular functions, which can be slow and challenging to compute. Here we investigate the accuracy and convergence of a simpler representation, namely modeling the unknown surface charge distribution as a set of discrete point charges on the surface. We find that at low resolution, point-based BEM is more accurate than panel-based methods, due to the fact that the protein surface is sampled directly, and can be of significant value for numerous important calculations that require only moderate accuracy, such as the preliminary stages of rational drug design and protein engineering.
Application of Steepest-Entropy-Ascent Quantum Thermodynamics to Predicting Heat and Mass Diffusion From the Atomistic Up to the Macroscopic Level
Authors: Li Guanchen , von Spakovsky Michael R.
Published: March 2016

Conventional first principle approaches for studying non-equilibrium or far-from-equilibrium processes all depend on the mechanics of individual particles or quantum states and as a result, require too many details of the mechanical features of the system to easily or even practically arrive at the value of a macroscopic property. In contrast, thermodynamics, which has been extremely successful in the stable equilibrium realm, provides an approach for determining a macroscopic property without going into the mechanical details. Nonetheless, such a phenomenological approach is not generally applicable to a non-equilibrium process except in the near-equilibrium realm and under the limiting local equilibrium and continuum assumptions, both of which prevent its application across all scales. To address these drawbacks, steepest-entropy-ascent quantum thermodynamics (SEAQT) can be used. It provides an ensemble-based, thermodynamics, first principles approach applicable to the entire non-equilibrium realm even that far-from-equilibrium and does so with a single kinematics and dynamics able to cross all temporal and spatial scales. Based on prior developments by the authors, this paper applies SEAQT to the study of mass and heat diffusion. Specifically, the study focuses on the thermodynamic features of far-from-equilibrium state evolution. Two kinds of size effects on the evolution trajectory, i.e., concentration and volume effects, are discussed.
Representation of Function, Behavior, Structure and Interrelationships at Different Abstract Levels of Product Information
Authors: Baysal Mehmet Murat , Roy Utpal
Published: March 2016

To foster an effective collaboration during product lifecycle activities, product information must include data on geometry and topology, assembly constraints and associations, design and product processes, the functions and behaviors of the product, and the design intent. A product has many associations among its parts in terms of assembly, function, behavior, tolerance, kinematics, etc. These associations need to be represented in a consistent way, so that they will not conflict with each other. There have been many efforts to connect function and behavior to structure, but there exists no complete, consistent method yet. It is especially critical in the conceptual development of a product, as well as during its evaluation. The work described in this paper should help people make intelligent decisions by allowing them to manage product lifecycle activities from different perspectives (i.e., function, structure, etc.) using the knowledge of how the product information is interconnected, and how artifacts affect each other.

In this study, functional and behavioral models have been developed to represent assembly-related product knowledge. These models connect functions, behaviors and structures — through the parts of artifacts using input/outputs and artifacts’ functional associations (i.e. spatial and design relations/requirements) at different abstract levels of product information. A planetary gearbox has been used as a case study to show how the functional/structural model can be implemented.
Control for Camera of a Telerobotic Human Computer Interface
Authors: Sestito Antonio G. , Frasca Tyler M. , O’Rourke Aidan , Ma Lili , Dow Douglas E.
Published: March 2016

Controlling remote robots is a difficult task for human computer interface (HCI). Control of remote robots enables accomplishment of tasks without the human controller physically present due to safety concerns or the expert cannot be physically present. This paper presents a method for using an Oculus Rift to improve HCI for telerobotic control. Using the Oculus, an operator could become immersed in the robot’s environment and could more naturally control the desired position of a remotely positioned vision system via head movements. To provide the appropriate visual feedback, a three-axis gimbal was implemented as a test platform. Through software implemented motion tracking, the response of the Oculus was compared to that of a mouse which demonstrates the efficiency of the proposed system over comparable HCI.
Turbocharging of a Heavy Duty Diesel Engine for a Specific Power and Performance Enhancement
Authors: Emara Kareem , Emara Ahmed , Abdel Razek Elsayed
Published: March 2016

Increase of the capacity of heavy duty diesel engines is of great interest in the way of power enhancement in many engine applications. Turbocharger is one of the most important ways used to increase the engine specific power. The present study aimed to develop an analytical model to simulate the performance and combustion characteristics of a direct injection diesel engine. This model depends on the basic conservation equations of continuity, momentum and energy as well as equation of state, these equations are solved together numerically by using two steps Lax-Wendroff scheme. To address this, a comprehensive computer “FORTRAN” code was developed and applied to study the performance and combustion characteristics of a six-cylinder, four stroke, direct injection, heavy duty diesel engine as a base engine and when its power upgraded by 15% using a turbocharger. This code is open source, preprocessor is user-friendly and very easy in work and will used at any time. The computed results are compared with the results obtained by applying the engine simulation DIESEL-RK software. But the DIESEL-RK solver may be run under the control of an external code. In that case the interface of the program includes input & output text files. Templates of these files are generated automatically. The developed model provides reasonable estimates and the experimental validation of the model show that an appropriate agreement between mathematical model, DIESEL-RK software, and the real measurements, in addition the capability of the model to predict satisfactorily the performance, and combustion characteristics of the direct injection diesel engine. Simulation study was also performed to compare the turbocharged engine with the naturally aspirated direct injection diesel engine. This study examined the engines for operating parameters like brake power and brake specific fuel consumption over the entire speed range and revealed that turbocharging offers higher brake power and lower brake specific fuel consumption values for most of the operating range. The results indicated that turbocharging offers marginally higher brake thermal efficiency and enhancing the engine performance.
Methods of Accident Reconstruction: Biomechanical and Human Factors Considerations
Authors: Knox Erick H. , Mathias Anne C. , Stern Amber Rath , Van Bree Michael P. , Brickman Dennis B.
Published: March 2016

Accident reconstruction involving consumer products and industrial equipment often requires biomechanical and/or human factors analyses to help determine the root cause of an accident scenario. A systematic method has been established which incorporates numerous components of the sciences of biomechanics and human factors and uses the scientific method as the framework for evaluating competing theories. Using this method, available data are gathered pertaining to the accident or incident and organized in a modified Haddon matrix, with categories for Man [person(s) involved in the accident], Product/Machine, and Environment. Information about the person(s) is separated further into injury and human factors components. The injuries are viewed as physical evidence, where each injury occurred as a result of being exposed to a specific combination of energy, force, motion/deflection, acceleration, etc. The injuries are evaluated with known injury research and categorized with a specific type, location, mechanism, and injury threshold. This injury evidence is then reconciled with the other physical evidence developed from the accident environment and product/machine categories. Human factors evaluations of body size, posture, capabilities, sensory perception, reaction time, and movements create similar information that is also reconciled with the rest of the evidence from an accidental circumstance. At the core of this method is developing scientific data or information that can be used to support or refute accident reconstruction conclusions. An accurate and complete accident reconstruction using the available data must be consistent with the laws of physics, and the physics of interaction between the man, product/machine, and environment.
Methodology for the Energy Characterization of Type-Approval and Real-World Driving Cycles for Passenger Vehicles
Authors: Martins Luis A. S. B. , Araujo Bruno J. O. , Martins Jorge J. G. , Brito Francisco C. P.
Published: March 2016

The development of electric and hybrid electric vehicles is motivated by the high prices of fossil fuels, the need for better efficiency and the minimization of pollutants and greenhouse gas emissions. There are several possible technologies for these vehicles but Plug-in Hybrid Electric Vehicles (PHEV) and Fully Electric Vehicles (FEV) are becoming popular. They both require advanced energy storage and management systems. In the design of these powertrains it is of capital importance to evaluate, not only the required traction energy, but also the energy involved in braking and that has the possibility of being regenerated, in real-world routes and traffic conditions. Type-approval driving cycles are insufficient for this purpose, as they do not include parameters that substantially affect the vehicle dynamics, such as road slope and additional friction due to road winding. This work presents a methodology for the energy characterization of driving cycles, based on the numerical integration of specific power, including new parameters such as specific traction and braking energies, cumulative uphill and downhill slopes and cornering friction energy, as well as energy-power distributions. The methodology will help in the comparison of the available type-approval driving cycles and in the definition of more realistic ones that can be used for better assessment of fuel consumption and emissions of vehicles. With input data from real routes, the procedure will be useful in the design of advanced electrical or hybridized powertrain systems, both to size the components and to define appropriate energy management strategies, with the final goal of an improved efficiency. The methodology will also be valuable in the energy classification of European roads. The paper describes the mathematical model, which allows the quantification of all the important energy flows involved in the evolution of a reference vehicle, following a route. This model was developed in the MatLab/Simulink environment and was applied to the characterization of three type-approval cycles and to three real routes. The results indicate that the type-approval cycles are too soft to adequately emulate present day aggressive traffic conditions. Driving cycles simulating significant road slopes and sinuosity should be used in the future, both for consumption and emissions certification and in the development of new powertrains.
Mesoscopic Simulation of Slip Motion for Gas Flow in Nanochannels
Authors: Madiebo Kingsley I. , Nasrabadi Hadi , Gildin Eduardo
Published: March 2016

In this paper the Lattice Boltzmann method (LBM) was used to investigate gas flow in nano-channels, the critical region beyond which indefinite slip motion occurs in this channel and its effect on the deduced permeability. We defined a parallel-bounded planar two-dimensional domain for our simulation and calculated the system velocity profile.

Numerical conformity was achieved when compared with the Hagen-Poiseuille’s equation. Good agreement was also established between the simulation and existing models reported in literature. A closer look at the region of full slip motion was also done and we observed that above a critical slip coefficient, a sudden significant increase in slip motion sets-in indefinitely with respect to the system time scale.

The results indicate that when the LBM is used in gas flow simulation in nano-channels, if the slip effect is increased there is an effective increase in the fluid velocity and this affects the deduced permeability.
Study of the Transient Behavior and Microstructure Degradation of a SOFC Cathode Using an Oxygen Reduction Model Based on Steepest-Entropy-Ascent Quantum Thermodynamics
Authors: Li Guanchen , von Spakovsky Michael R.
Published: March 2016

Oxygen reduction in a solid oxide fuel cell (SOFC) cathode involves a non-equilibrium process of coupled mass and heat diffusion and electrochemical and chemical reactions. These phenomena occur at multiple temporal and spatial scales, from the mesoscopic to the atomistic level, making the modeling, especially in the transient regime, very difficult. Nonetheless, multi-scale models are needed to improve an understanding of oxygen reduction and guide fuel cell cathode design. Existing methods are typically phenomenological or empirical in nature so their application is limited to the continuum realm and quantum effects are not captured.

Steepest-entropy-ascent quantum thermodynamics (SEAQT) can be used to model non-equilibrium processes (even those far-from equilibrium) from the atomistic to the macroscopic level. The non-equilibrium relaxation is characterized by the entropy generation, and the study of coupled heat and mass diffusion as well as electrochemical and chemical activity are unified into a single framework. This framework is used here to study the transient and steady state behavior of oxygen reduction in an SOFC cathode system. The result reveals the effects on performance of the different timescales of the varied phenomena involved and their coupling. In addition, the influence of cathode microstructure changes on performance is captured.
Anand Viscoplasticity Model for the Effect of Aging on Mechanical Behavior of SAC305 Operating at High Strain Rate and High Temperature
Authors: Lall Pradeep , Zhang Di , Suhling Jeff , Locker David
Published: March 2016

Portable products such as smartphones and tablets stay in the powered on condition for a majority of their operational life during which time the device internals are maintained at higher than ambient temperature. Thus, it would be expected for interconnects in portable products to be at a temperature high than room temperature when subjected to accidental drop or shock. Furthermore, electronics in missile-applications may be subjected to high strain rates after prolonged period of storage often at high temperature. Electronics systems including interconnects may experience high strain rates in the neighborhood of 1–100 per sec during operation at high temperature. However, the material properties of SAC305 leadfree solders at high strain rates and high operating temperatures are scarce after long-term storage. Furthermore, the solder interconnects in simulation of product drop are often modeled using elastic-plastic properties or linear elastic properties, neither of which accommodate the effect of operating temperature on the solder interconnect deformation at high operating temperature. SAC305 solders have been shown to demonstrate the significant degradation of mechanical properties including the tensile strength and the elastic modulus after exposure to high temperature storage for moderate periods of time. Previously, Anand’s viscoplastic constitutive model has been widely used to describe the inelastic deformation behavior of solders in electronic components under thermo-mechanical deformation. Uniaxial stress-strain curves have been plotted over a wide range of strain rates (ε̇ = 10, 35, 50, 75 /sec) and temperatures (T = 25, 50, 75, 100, 125°C). Anand viscoplasticity constants have been calculated by non-linear fitting procedures. In addition, the accuracy of the extracted Anand constants has been evaluated by comparing the model prediction and experimental data.
Theoretical Study of Heat Pump System Using R744/R1234yf as Refrigerant
Authors: Ju Fujun , Fan Xiaowei , Chen Yaping
Published: March 2016

In this paper, the eco-friendly zeotropic mixture, R744/R1234yf was chosen as the alternative refrigerant in the instant heat pump water heater system. The cycle performance of heat pump was analyzed theoretically under the nominal working condition of heat pump system. The prediction results show that the new mixture has significant advantages for the instant heat pump with a large heat-sink temperature lift, and there exists an optimal mass fraction of R744/R1234yf, at which the maximum COPh should be obtained. The optimal mass fraction of R744/R1234yf is 17/83 and the system COPh should be attained to 4.29.
Effects of Flow Separation on a Highly Loaded, Low-Pressure Gas Turbine Blade at Low Reynolds Numbers
Authors: Pharris Tyler M. , Hirst Olivia E. , Van Treuren Kenneth W.
Published: March 2016

Current gas turbine engines experience a loss in performance due to the low Reynolds number flow in the low-pressure turbine. This low flow speed can result in separation of the air from the blade surface, reducing the efficiency of the engine. The Baylor University Cascade wind tunnel (BUC) is being used to study this flow separation. A cascade wind tunnel contains a row of turbine vanes that simulates a turbine wheel. The BUC is capable of simulating the environment seen by the low-pressure turbine at high altitudes by producing Reynolds numbers varying from 25,000 to 400,000. The L1A blade profile is currently being tested. Coefficient of pressure (Cp) plots show a less than 1% difference between surface pressure locations when comparing the most inboard and outboard test blades. This agreement demonstrates the flow uniformity in the tunnel. Cp plots also compared favorably to the literature, validating the BUC operation and providing insight into how Reynolds numbers and free stream turbulence intensity (FSTI) affect flow separation. The literature and this study showed the size and reattachment of the separation bubble was highly dependent on the FSTI for lower Reynolds numbers (25,000 to 200,000). This comparison also showed that the size of the separation bubble and the location was not heavily impacted by FSTI for Reynolds numbers above 200,000. Tests in the future will be conducted to determine the actual FSTI of the BUC. Once completely validated, future studies with the BUC may include use of particle image velocimetry (PIV) to visualize the flow, a gold foil steady state technique using liquid crystals to measure heat transfer, and a series of deposition tests using surface roughness (sandpaper or textured sprays) to measure performance loss under these conditions. The ultimate goal of this research is to improve blade design in the low pressure turbine for all commercial and military aircraft.
Standardization of Hemagglutination Inhibition Assay for Influenza Serology Allows for High Reproducibility between Laboratories
Authors: Zacour Mary , Ward Brian J. , Brewer Angela , Tang Patrick , Boivin Guy , Li Yan , Warhuus Michelle , McNeil Shelly A. , LeBlanc Jason J. , Hatchette Todd F.
Published: March 2016

Standardization of the hemagglutination inhibition (HAI) assay for influenza serology is challenging. Poor reproducibility of HAI results from one laboratory to another is widely cited, limiting comparisons between candidate vaccines in different clinical trials and posing challenges for licensing authorities. In this study, we standardized HAI assay materials, methods, and interpretive criteria across five geographically dispersed laboratories of a multidisciplinary influenza research network and then evaluated intralaboratory and interlaboratory variations in HAI titers by repeatedly testing standardized panels of human serum samples. Duplicate precision and reproducibility from comparisons between assays within laboratories were 99.8% (99.2% to 100%) and 98.0% (93.3% to 100%), respectively. The results for 98.9% (95% to 100%) of the samples were within 2-fold of all-laboratory consensus titers, and the results for 94.3% (85% to 100%) of the samples were within 2-fold of our reference laboratory data. Low-titer samples showed the greatest variability in comparisons between assays and between sites. Classification of seroprotection (titer ≥ 40) was accurate in 93.6% or 89.5% of cases in comparison to the consensus or reference laboratory classification, respectively. This study showed that with carefully chosen standardization processes, high reproducibility of HAI results between laboratories is indeed achievable.
Giant kidney worms in a patient with renal cell carcinoma
Authors: Kuehn Jemima , Lombardo Lindsay , Janda William M , Hollowell Courtney M P
Published: March 2016

Dioctophyma renale(D. renale), or giant kidney worms, are the largest nematodes that infect mammals. Approximately 20 cases of human infection have been reported. We present a case of a 71-year-old man with a recent history of unintentional weight loss and painless haematuria, passing elongated erythematous tissue via his urethra. CT revealed a left renal mass with pulmonary nodules and hepatic lesions. On microscopy, the erythematous tissue passed was identified asD. renale.On subsequent renal biopsy, pathology was consistent with renal cell carcinoma. This is the first reported case of concomitantD. renaleinfection and renal cell carcinoma, and the second reported case ofD. renaleinfection of the left kidney alone.
Chemical weathering east and west of the emerging Caledonides in the Silurian – Early Devonian, with implications for climate
Authors: Kiipli Enli , Kiipli Tarmo , Kallaste Toivo , Märss Tiiu
Published: March 2016

The late Llandovery (Silurian) – early Lochkovian (Devonian) climate of the tropical zone is tracked considering orogenesis, global glaciation events, and cratonic drift. Mineral and chemical compositions of clay fractions of Canadian (the Franklinian Basin) and Estonian (the Baltoscandian Basin) sedimentary rocks from different sides of the emerging Caledonides were studied, using clay as an index of climatic conditions of the provenance area. Illite is the main clay mineral, with addition of orthoclase, muscovite, and chlorite in both regions. Authigenic chert is present in some Canadian sections. The similarity of clay minerals and elemental composition in the two regions suggest common chemical weathering conditions. Nevertheless, the Al/Ti ratio of the <1 μm clay fraction, the proxy for climate’s aridity–humidity and weathering intensity, reveals differences. The Franklinian Basin in Laurentia shows a shift of climate from humid to semi-humid in pace with the uplift of the Caledonides. The sub-meridional mountain chain in the east reduced the amount of rainfall and, therefore, caused drier climate than could have been expected from the low latitudinal position of the area. The material from the Baltoscandian Basin reveals semi-arid and arid climate for most of the Silurian. Although the southern part of the Fennoscandian Shield was situated in desert latitudes, the evidence from the provenance of clay suggests that the climate was not fully arid. In Baltoscandia, covariation between low Al/Ti of clay and negative shifts of δ13C of marine carbonates is recorded at some stratigraphical levels, suggesting a link between humid climatic episodes in mainland and waning of glaciers at the South Pole.
Conformal barrier for new vector bosons decay to the Higgs
Authors: Fukano Hidenori S. , Matsuzaki Shinya , Yamawaki Koichi
Published: March 2016

The ATLAS collaboration has recently reported excesses about 2.5 [Formula: see text] at mass around 2 TeV in the diboson channels, which can be identified with new vector bosons as a hint for the new physics. It is shown that spontaneously broken conformal/scale symmetry prohibits new vector bosons decay to the Higgs, which is contrasted to the popular “equivalence theorem” valid only in a special limit not necessarily relevant to the 2 TeV mass. If the decay V [Formula: see text] WH/ZH is not observed in the ongoing Run-II of the large hadron collider (LHC), then the 125 GeV Higgs can be a dilaton.
Low-frequency bandgaps of two-dimensional phononic crystal plate composed of asymmetric double-sided cylinder stubs
Authors: Song Ailing , Wang Xiaopeng , Chen Tianning , Jiang Ping , Bao Kai
Published: March 2016

In this paper, we theoretically investigate the propagation characteristics of Lamb wave in a two-dimensional (2D) asymmetric phononic crystal (PC) plate composed of cylinder stubs of different radius deposited on both sides of a thin homogeneous plate. The dispersion relations, transmission spectra and displacement fields of the eigenmodes are calculated by using the finite element method (FEM). Two complete bandgaps (BGs) can be found in low-frequency range and the transmission spectra coincide with the band structures. We investigate the evolution of dispersion relations with the decrease of the upper stub radius. The physical mechanism of the upper stub radius effect is also studied with the displacement fields of the unit cell. Numerical results show that the symmetry of the stub radius can remarkably influence the band structures and the asymmetric double-sided plate exhibits a new bandgap (BG) in lower frequency range due to the coupling between the lower stub’s resonant mode and the plate’s Lamb mode becomes weak and the adjacent bands separate. Moreover, we further investigate the effect of the stub height on the dispersion relations and find that the BGs shift to lower frequency regions with the increase of the stub height. In addition, the BGs’ sensitivity to the upper stub radius and the stub height is discussed. The low-frequency BGs in the proposed PC plate can potentially be used to control and insulate vibration in low frequency range.
Structural, morphological, and optoelectrical characterization of Bi2S3thin films grown by co-evaporation
Authors: Mesa F. , Arredondo C. A. , Vallejo W.
Published: March 2016

This work presents the results of synthesis and characterization of polycrystalline [Formula: see text]-type Bi2S3thin films. The films were grown through a chemical reaction from co-evaporation of their precursor elements in a soda-lime glass substrate. The effect of the experimental conditions on the optical, morphological structural properties, the growth rate, and the electrical conductivity [Formula: see text] was studied through spectral transmittance, X-ray diffraction (XRD), atomic force microscopy (AFM) and [Formula: see text] versus [Formula: see text] measurements, respectively. The results showed that the films grow only in the orthorhombic Bi2S3bismuthinite phase. It was also found that the Bi2S3films present an energy band gap [Formula: see text] of about 1.38 eV. In addition to these results, the electrical conductivity of the Bi2S3films was affected by both the transport of free carriers in extended states of the conduction band and for variable range hopping transport mechanisms, each one predominating in a different temperature range.
Local decomposition of solid solutions, nanostructures and optical materials with negative refractive index
Authors: Ishchuk Valeriy M. , Sobolev Vladimir
Published: March 2016

In this paper, a possibility of use of the controlled decomposition of solid solutions of oxides with perovskite structure in the state of coexisting domains of the antiferroelectric (AFE) and ferroelectric (FE) phases for manufacturing materials with the negative refractive index is demonstrated. The lead zirconate titanate-based solid solutions are considered as an example of substances suitable for creation of such materials. Manufactured composites constitute a dielectric AFE matrix with a structure of conducting interphase boundaries separating domains of the FE and AFE phases. The electric conductivity of the interphase boundaries occurs as a result of the local decomposition of the solid solutions in the vicinity of these boundaries. The decomposition process and consequently the conductivity of the interphase boundaries can be controlled by means of external influences.
Multi-band polarization independent cylindrical metamaterial absorber and sensor application
Authors: Dincer Furkan , Karaaslan Muharrem , Colak Sule , Tetik Erkan , Akgol Oguzhan , Altıntas Olcay , Sabah Cumali
Published: March 2016

A multi-band perfect metamaterial absorber (MA) based on a cylindrical waveguide with polarization independency is numerically presented and investigated in detail. The proposed absorber has a very simple configuration, and it operates at flexible frequency ranges within the microwave frequency regime by simply tuning the dimensions of the structure. The maximum absorption values are obtained as 99.9%, 97.5%, 85.8%, 68.2% and 40.2% at the frequencies of 1.34 GHz, 2.15 GHz, 3.2 GHz, 4.31 GHz and 5.41 GHz, respectively. The numerical studies verify that the proposed model can provide multi-band perfect absorptions at wide polarization and incident angles due to its rotational symmetry feature. We have also realized sensor and parametric study applications in order to show additional features of the suggested model. The suggested MA enables myriad potential applications in medical technologies, sensors and in defense industry etc.
High Speed Implementation of a SHA-3 Core on Virtex-5 and Virtex-6 FPGAs
Authors: Rao Muzaffar , Newe Thomas , Grout Ian , Mathur Avijit
Published: March 2016

This work presents a novel technique for a high-speed implementation of the newly selected cryptographic hash function, Secure Hash Algorithm-3 (SHA-3) on Xilinx’s Virtex-5 and Virtex-6 Field Programmable Gate Arrays (FPGAs). The proposed technique consists of a two-phase implementation approach. In the first phase, all steps of the SHA-3 core are logically combined, which helps to eliminate the intermediate states of core function, these states utilize more area and also slow the execution. The second phase deals with the hardware implementation of the first phase equations using Xilinx Look-Up-Table (LUT) primitives. This two phase implementation technique results in a throughput of 19.241[Formula: see text]Gbps on a Virtex-6 FPGA; this is the highest reported throughput to date for an FPGA implementation of SHA-3. This high throughput makes this technique ideally suited for the provision of Bump In The Wire (BITW) security for Internet of Things (IoT) applications.
Violations of discrete space–time symmetries in chiral effective field theory
Authors: de Vries J. , Meißner Ulf-G.
Published: March 2016

We review recent progress in the theoretical description of the violation of discrete space–time symmetries in hadronic and nuclear systems. We focus on parity-violating and time-reversal-conserving interactions which are induced by the Standard Model weak interaction, and on parity- and time-reversal-violating interactions which can be caused by a nonzero QCD [Formula: see text] term or by beyond-the-Standard Model physics. We discuss the origins of such interactions and review the development of the chiral effective field theory extension that includes discrete symmetry violations. We discuss the construction of symmetry-violating chiral Lagrangians and nucleon–nucleon potentials and their applications in few-body systems.
Uncertainty quantification of effective nuclear interactions
Authors: Pérez R. Navarro , Amaro J. E. , Arriola E. Ruiz
Published: March 2016

We give a brief review on the development of phenomenological NN interactions and the corresponding quantification of statistical uncertainties. We look into the uncertainty of effective interactions broadly used in mean field calculations through the Skyrme parameters and effective field theory counterterms by estimating both statistical and systematic uncertainties stemming from the NN interaction. We also comment on the role played by different fitting strategies on the light of recent developments.
A new renormalization procedure of the quasiparticle random phase approximation
Authors: Raduta A. A. , Raduta C. M.
Published: March 2016

The ground state of a many body Hamiltonian considered in the quasiparticle representation is redefined by accounting for the quasiparticle quadrupole pairing interaction. The residual interaction of the newly defined quasiparticles is treated by the quasiparticle random phase approximation (QRPA). Solutions of the resulting equations exhibit specific features. In particular, there is no interaction strength where the first root is vanishing. A comparison with other renormalization methods is presented. Application to a single [Formula: see text]-shell allows for the results interpretation by comparing them with those obtained by exact calculations.
Abelian groups whose nonzero endomorphisms have nonessential kernels
Authors: Alizade Rafail , Isah Surajo Ibrahim
Published: March 2016

In this paper, we describe completely the [Formula: see text]-singular subgroup of an abelian group and a [Formula: see text]-nonsingular abelian group in terms of the basic subgroups of its [Formula: see text]-components and the quotient group by the torsion part. We also prove that a pure subgroup and a quotient group by a pure subgroup of a [Formula: see text]-nonsingular abelian group are [Formula: see text]-nonsingular and give a condition under which a pure extension of a [Formula: see text]-nonsingular abelian group by a [Formula: see text]-nonsingular group is [Formula: see text]-nonsingular.
Improving Forecasting Performance by Exploiting Expert Knowledge: Evidence from Guangzhou Port
Authors: Huang Anqiang , Qiao Han , Wang Shouyang , Liu John
Published: March 2016

Expert knowledge has been proved by substantial studies to be contributory to higher forecasting performance; meanwhile, its application is criticized and opposed by some groups for biases and inconsistency inherent in experts’ subjective judgment. This paper proposes a new approach to improving forecasting performance, which takes advantage of expert knowledge by constructing a constraint equation rather than directly adjusting the predicted values by experts. For the comparison purpose, the proposed approach, together with several widely used models including ARIMA, BP-ANN and the judgment model (JM), is applied to forecasting the container throughput of Guangzhou Port, which is one of the most important ports of China. Forecasting performances of the above models are compared and the results clearly show superiority of the proposed approach over its rivals, which implies that expert knowledge will make positive contribution as long as it is used in a right way.
Pseudo-almost periodic solution for impulsive hematopoiesis model with infinite delays and linear harvesting term
Authors: Xia Zhinan , Wang Dingjiang
Published: March 2016

In this paper, a generalized impulsive model of hematopoiesis with infinite delays and linear harvesting term is investigated. The main purpose of this paper is to study the existence, uniqueness and exponential stability of the positive pseudo-almost periodic solutions, which improve and extend some known relevant results. Moreover, an example is given to illustrate the main findings.
Investigation of the Chromosphere–Corona Interface with the Upgraded Very High Angular Resolution Ultraviolet Telescope (VAULT2.0)
Authors: Vourlidas Angelos , Beltran Samuel Tun , Chintzoglou Georgios , Eisenhower Kevin , Korendyke Clarence , Feldman Ronen , Moser John , Shea John , Johnson-Rambert Mary , McMullin Don , Stenborg Guillermo , Shepler Ed , Roberts David
Published: March 2016

Very high angular resolution ultraviolet telescope (VAULT2.0) is a Lyman-alpha (Ly[Formula: see text]; 1216[Formula: see text]Å) spectroheliograph designed to observe the upper chromospheric region of the solar atmosphere with high spatial ([Formula: see text]) and temporal (8[Formula: see text]s) resolution. Besides being the brightest line in the solar spectrum, Ly[Formula: see text] emission arises at the temperature interface between coronal and chromospheric plasmas and may, hence, hold important clues about the transfer of mass and energy to the solar corona. VAULT2.0 is an upgrade of the previously flown VAULT rocket and was launched successfully on September 30, 2014 from White Sands Missile Range (WSMR). The target was AR12172 midway toward the southwestern limb. We obtained 33 images at 8[Formula: see text]s cadence at arc second resolution due to hardware problems. The science campaign was a resounding success, with all space and ground-based instruments obtaining high-resolution data at the same location within the AR. We discuss the science rationale, instrument upgrades, and performance during the first flight and present some preliminary science results.
Severe Malaria Associated with Plasmodium falciparum and P. vivax among Children in Pawe Hospital, Northwest Ethiopia
Authors: Geleta Getachew , Ketema Tsige
Published: March 2016

Despite rigorous effort made to control malaria for more than a century, it is still among the main public health problems in least developed regions of the world. Majority of deaths associated with malaria occur in sub-Sahara Africa among biologically risked groups. Thus, this study was designed to assess the incidence of severe malaria syndromes among children in Pawe Hospital, Northwest Ethiopia. Children seeking medication for malaria infection in Pawe Hospital during the study period were recruited. Sociodemographic characteristics, physical, hematological, and clinical features of complicated malaria were assessed following standard parasitological and clinical procedures. A total of 263 children were found malaria positive. Among these, 200 were infected with Plasmodium falciparum. Most of the severe malaria symptoms were observed among children infected with P. falciparum and P. vivax. The study showed that significant number of the children developed severe life threatening malaria complications. This calls for prompt early diagnosis and effective treatment of patients to reduce mortality and complications associated with malaria in the study site.
Neuroprotective Effects of Isosteviol Sodium Injection on Acute Focal Cerebral Ischemia in Rats
Authors: Hu Hui , Sun Xiao ou , Tian Fang , Zhang Hao , Liu Qing , Tan Wen
Published: March 2016

Previous report has indicated that isosteviol has neuroprotective effects. However, isosteviol was administered preventively before ischemia and the inclusion criteria were limited. In the present study, a more soluble and injectable form of isosteviol sodium (STVNA) was administered intravenously hours after transient or permanent middle cerebral artery occlusion (tMCAO or pMCAO) to investigate its neuroprotective effects in rats. The rats were assessed for neurobehavioral deficits 24 hours after ischemia and sacrificed for infarct volume quantification and histology evaluation. STVNA 10 mg·kg−1 can significantly reduce the infarct volumes compared with vehicle in animals subjected to tMCAO and is twice as potent as previously reported. Additionally, the therapeutic window study showed that STVNA could reduce the infarct volume compared with the vehicle group when administered 4 hours after reperfusion. A similar effect was also observed in animals treated 4 hours after pMCAO. Assessment of neurobehavioral deficits after 24 hours showed that STVNA treatment significantly reduced neurobehavioral impairments. The number of restored NeuN‐labeled neurons was increased and the number of TUNEL positive cells was reduced in animals that received STVNA treatment compared with vehicle group. All of these findings suggest that STVNA might provide therapeutic benefits against cerebral ischemia‐induced injury.
A Chaos Robustness Criterion for 2D Piecewise Smooth Map with Applications in Pseudorandom Number Generator and Image Encryption with Avalanche Effect
Authors: Han Dandan , Min Lequan , Hao Longjie
Published: March 2016

This study proposes a chaos robustness criterion for a kind of 2D piecewise smooth maps (2DPSMs). Using the chaos robustness criterion, one can easily determine the robust chaos parameter regions for some 2DPSMs. Combining 2DPSM with a generalized synchronization (GS) theorem, this study introduces a novel 6-dimensional discrete GS chaotic system. Based on the system, a 216-word chaotic pseudorandom number generator (CPRNG) is designed. The key space of the CPRNG is larger than 2996. Using the FIPS 140-2 test suit/generalized FIPS 140-2 test suit tests the randomness of the 1000 key streams consists of 20,000 bits generated by the CPRNG, the RC4 algorithm, and the ZUC algorithm, respectively. The numerical results show that the three algorithms do not have significant differences. The CPRNG and a stream encryption scheme with avalanche effect (SESAE) are used to encrypt an image. The results demonstrate that the CPRNG is able to generate the avalanche effects which are similar to those generated via ideal CPRNGs. The SESAE with one-time-pad scheme makes any attackers have to use brute attacks to break our cryptographic system.
Highly Isotactic Poly(N-butenyl-carbazole): Synthesis, Characterization, and Optical Properties
Authors: Botta Antonio , Venditto Vincenzo , Rubino Alfredo , Pragliola Stefania
Published: March 2016

The synthesis of isotactic poly(N-butenyl-carbazole) (i-PBK) by using homogeneous isospecific Ziegler-Natta catalytic system is reported. The achieved polymer is crystalline and shows, to DSC and X-ray analysis, two distinct crystalline phases.i-PBK FTIR spectrum and X-ray diffraction pattern are compared with those of poly(N-vinylcarbazole) (PVK). The observed differences are tentatively associated with higher flexibility of thei-PBK chains due to the alkylene group connecting the carbazole group to the main chain.i-PBK optical properties are also compared with those of PVK and isotactic poly(N-pentenyl-carbazole) (i-PPK), a higher homologue ofi-PBK recently used as emitting layer in organic light emitting diodes (OLEDs) showing white light emission. The close similarity of the fluorescence spectra ofi-PBK andi-PPK is a promising basis for optical applications of this polymer.
Limit Cycles for the Class ofD-Dimensional Polynomial Differential Systems
Authors: Diab Zouhair , Makhlouf Amar
Published: March 2016

We perturb the differential systemx˙1=-x2(1+x1),x˙2=x1(1+x1), andx˙k=0fork=3,…,dinside the class of all polynomial differential systems of degreeninRd, and we prove that at mostnd-1limit cycles can be obtained for the perturbed system using the first-order averaging theory.