bluuebunny/crossref_metadata_2025 huggingface dataset:
Energy Maneuverability and Engine Performance Requirements
Authors: Caddy Michael J. , Arnold William K.
Published: March 2015

Fighter energy maneuverability has always been a means of determining performance advantage which in turn can be used to defeat an opponent in combat. In the first part of this paper the energy maneuverability concept is defined in simplistic terms as used by Naval fighter pilots and a standard means of comparing aircraft is disclosed. In the latter part of this paper a trade-off sensitivity analysis is generated for a generic future fighter showing the relationship between engine performance requirements and fighter maneuverability.
A Turbine Wheel Design Story
Authors: Taylor Wilson R. , Wheless Keith , Gray Lee G.
Published: March 2015

A Jet Fuel Starter (JFS) is used to start the F100 main propulsion engines for the F-15 fighter aircraft. The JFS is a dual rotor machine which consists of a gas generator spool and a power turbine spool. The gas generator turbine wheel was designed to be contained within the turbine case in the event of a JFS overspeed. This is done by the inclusion of a containment ring in the turbine case. The initial power turbine wheel design was not able to be contained by its turbine case. A design decision was made to make this wheel frangible, that is, in an overspeed condition the wheel would break into small pieces which could be contained by the existing turbine case. An alternative design solution is proposed in this paper and an analytical proof-of-concept is presented.
A Method of Evaluating Life Cycle Costs of Industrial Gas Turbines
Authors: Spector R. B.
Published: March 2015

When aero-derivative gas turbines were first introduced into industrial service, the prime criterion for assessing the “relative value” of equipment was derived hy dividing the initial (or capital) cost of the equipment by the number of kilowatts produced. The use of “dollars per kilowatt” as an assessment parameter emanated from the utility sector and is still valid providing that the turbo-machinery units under consideration possess similar performance features with regard to thermal efficiency. Second generation gas turbines being produced today possess thermal efficiencies approximately forty-five percent greater than those previously available. Thus, a new criterion is required to provide the purchaser with a better “value” perspective to differentiate the various types of turbo-machinery under consideration.

This paper presents a technique of combining the initial cost of equipment with the costs of fuel consumed, applied labor and parts to arrive at an assessment parameter capable of comparing the relative merits of varying types of turbo-machinery. For simplicity, this paper limits the life cycle cost derivation and discussion to turbo-generator units; however, the principles of this type of life cycle analysis can also be applied to gas turbines in mechanical drive applications and/or combined cycles.
Battle Tanks of the Future: A Need for Turbine Power
Authors: Banthin Clifford , Deman Jochen
Published: March 2015

A battle tank propulsion system incorporating gas turbine power is reviewed. Present and future propulsion needs of the tank are discussed including integration of the engine with other tank subsystems. Virtues of the turbine are enumerated and compared to other candidate tank engines.
Performance Levels Obtainable From Steam-Gas Turbine Combined Cycles
Authors: Negri di Montenegro G. , Bettocchi R. , Cantore G. , Naldi G.
Published: March 2015

This study aims at the evaluation of the best performance obtainable from steam-gas turbine combined plants both in a new plant design and in improving existing steam plants by adding a topping gas turbine system.

A method of comparison is presented here, based on the choice of a steam-gas reference cycle which has shown to be particularly suitable for a general study.

A thermodynamic analysis has been carried out showing the influence on the combined plant overall efficiency of the parameters characterizing both the gas and steam cycles.

The reference cycle as well as those derivable from it by modifying the gas portion cycle only has been studied.

The analysis was also extended to evaluation of the gas to steam units output power ratio and of the efficiency increase when repowering a steam unit.

It has been shown that the combined cycle plants maximum overall-efficiency is achieved, whatever the steam cycle, when the gas turbine cycle operates at maximum specific work.

The result is that the best performance in combined cycle plants is achived by using multiple expansion with reheating in the gas cycle, when designing a new plant. When steam plants are to be repowered by means of existing gas turbine units, afterburning may be useful to improve performance.
Developmental Testing of a Heat Recovery Module for Industrial Cogeneration
Authors: Smith Kenneth O.
Published: March 2015

The initial developmental testing of a Heat Recovery Module (HRM) for cogeneration applications is described. The HRM is a prepackaged, pretested, skid-mounted system sized for the 500 to 1000 kW class of industrial gas turbine. Key features of the module include:

• a highly compact, once-through boiler fabricated using finned Incoloy 800 tubing

• a gas-fired supplementary burner capable of 1256 K (1800°F) refiring for greater system operating flexibility

• a “spill-over” mode of boiler operation that allows feedwater softening rather than deionization

• a fully integrated microprocessor-based control system

System design and performance data are presented.
The Use of Bezier Polynomial Patches to Define the Geometrical Shape of the Flow Channels of Compressors
Authors: Qinghuan Wang , Xiaoyan Huang
Published: March 2015

Based on the method of Casey (1), the present paper makes further development in using Bezier polynomial patches to define the geometrical shape of the flow channels of compressors. There are two advantages in this new method. First, in the geometrical construction process the blade profile and the contour of impeller’s meridional channel can be given by the same number of patches of the same degree so as to avoid more complicated repeat computations. Second, for curved surface construction there are no restrictions of linearity in the spanwise direction in order to match the distribution of flow angles at the inlet better and to fit the needs of various load models. Some examples have shown that the shapes produced by Bezier polynomial patches are general enough to be used in the design of new compressors and in approximation of the geometry of existing ones. The method is particularly suitable for incorporation into a computer-aided design procedure.
3-D Laser Anemometer Measurements in a Labyrinth Seal
Authors: Morrison G. L. , Johnson M. C. , Tatterson G. B.
Published: March 2015

The flow field inside a seven cavity labyrinth seal with a 0.00127 m clearance was measured using a 3-D laser doppler anemometer system. Through the use of this system, the mean velocity vector and the entire Reynolds stress tensor distributions were measured for the first, third, fifth, and seventh cavities of the seal. There was one large recirculation region present in the cavity for the flow condition tested, Re = 28,000 and Ta = 7,000. The axial and radial mean velocities as well as all of the Reynolds stress term became cavity independent by the third cavity. The azimuthal mean velocity varied from cavity to cavity with its magnitude increasing as the flow progressed downstream.
Linear Modeling of a Marine Gas Turbine Power Plant
Authors: Smith David L.
Published: March 2015

Aerospace gas turbine control designers have long recognized the suitability of modern control theory to deal with the severe problem of controlling multiple turbine outputs by generating multiple inputs. Marine gas turbines are equally complex and thus suggest a similar approach. Many modern methods require a state-space approach to turbine and load modeling, this paper outlines a procedure used to generate such a state-space model for a marine gas turbine plant. Simulation results for linear and non-linear plant models are compared and a modern controller development to achieve reduced fuel consumption is briefly discussed.
Application of Electron Microscopy for the Analysis of the Mechanical Behavior of Advanced Ceramics
Authors: Tennery V. J. , Allard L. F. , Nolan T. A. , Rawlins M. H.
Published: March 2015

The microstructure and fracture surfaces of two commercially available silicon nitride ceramics have been characterized using techniques of scanning and analytical transmission electron microscopy. These results have been correlated to mechanical property data (obtained from static and dynamic fatigue tests using four-point flexural test methods both at room temperature and at elevated temperature). For one of the materials, the results clarified failure mechanisms. For the other, the results showed how processing variables can affect microstructure (and thus mechanical behavior), and emphasized particularly that mechanical tests of billet-derived specimens may be unreliable in predicting the mechanical behavior of production components.
Quasi-3D Solutions for Transonic, Inviscid Flows by Adapative Triangulation
Authors: Holmes D. Graham , Lamson Scott H. , Connell Stuart D.
Published: March 2015

This paper describes an algorithm for computing two-dimensional transonic, inviscid flows. The solution procedure uses an explicit Runge-Kutta time marching, finite volume scheme. The computational grid is an irregular triangulation. The algorithm can be applied to arbitrary two-dimensional geometries. When used for analyzing flows in blade rows, terms representing the effects of changes in streamsheet thickness and radius, and the effects of rotation, are included. The solution is begun on a coarse grid, and grid points are added adaptively during the solution process, using criteria such as pressure and velocity gradients.

Advantages claimed for this approach are (a) the capability of handling arbitrary geometries (e.g., multiple, dissimilar blades), (b) the ability to resolve small-scale features (e.g., flows around leading edges, shocks) with arbitrary precision, and (c) freedom from the necessity of generating “good” grids (the algorithm generates its own grid, given an initial coarse grid).

Solutions are presented for several examples that illustrate the usefulness of the algorithm.
Industrial Gas Turbines With Subatmospheric Expansion
Authors: Georgiou D. P.
Published: March 2015

A modification is proposed to the basic Brayton cycle, by coupling the gas turbine with a jet pump. This allows subatmospheric pressure to exist at the exit of the turbine, a bigger turbine ratio and, hence, a higher efficiency. The jet pump operates with steam, produced from pressurized water heated by the exhaust gasses of the gas turbine. A simple configuration of the coupling is studied in some detail.
On the Prediction of Unsteady Forces on Gas-Turbine Blades: Part 2 — Viscous-Wake-Interaction and Axial-Gap Effects
Authors: Korakianitis Theodosios P.
Published: March 2015

This paper is a contribution to the study of the generation of unsteady forces on turbine blades due to viscous wake interaction and potential-flow interaction from upstream blade rows. A computer program is used to compute the unsteady forces on a rotor. Typical results for isolated viscous-wake interaction (no potential-flow interaction) are shown. These results indicate that the first spatial harmonic of the unsteady force may decrease for higher stator-to-rotor-pitch ratios. This trend is explained by considering the mechanisms by which the unsteady forces are generated. The mechanism by which the viscous wakes affect the flow field to generate these unsteady forces is shown to vary with the stator-to-rotor-pitch ratio and with the outlet flow angle of the stator. It is also shown that by varying the axial gap between rotor and stator one can attempt to minimize the magnitude of the unsteady part of the forces generated by the combined effects of viscous-wake interaction and potential-flow interaction.
Numerical study of the laser-tip coupling in surface plasmon assisted stacked-double-gate field emitter arrays
Authors: Oh Youngjin , Mustonen Anna , Feurer Thomas , Tsujino Soichiro
Published: March 2015

Recently, sub-wavelength-pitch stacked double-gate metal nanotip arrays have been proposed to realize high current, high brightness electron bunches for ultrabright cathodes for x-ray free-electron laser applications. With the proposed device structure, ultrafast field emission of photoexcited electrons is efficiently driven by vertical incident near infrared laser pulses, via near field coupling of the surface plasmon polariton resonance of the gate electrodes with the nanotip apex. In this work, in order to gain insight in the underlying physical processes, the authors report detailed numerical studies of the proposed device. The results indicate the importance of the interaction of the double-layer surface plasmon polariton, the position of the nanotip, as well as the incident angle of the near infrared laser pulses.
A new stationary gridline artifact suppression method based on the 2D discrete wavelet transform
Authors: Tang Hui , Tong Dan , Dong Bao Xu , Dillenseger Jean‐Louis
Published: March 2015

Purpose:

In digital x‐ray radiography, an antiscatter grid is inserted between the patient and the image receptor to reduce scattered radiation. If the antiscatter grid is used in a stationary way, gridline artifacts will appear in the final image. In most of the gridline removal image processing methods, the useful information with spatial frequencies close to that of the gridline is usually lost or degraded. In this study, a new stationary gridline suppression method is designed to preserve more of the useful information.

Methods:

The method is as follows. The input image is first recursively decomposed into several smaller subimages using a multiscale 2D discrete wavelet transform. The decomposition process stops when the gridline signal is found to be greater than a threshold in one or several of these subimages using a gridline detection module. An automatic Gaussian band‐stop filter is then applied to the detected subimages to remove the gridline signal. Finally, the restored image is achieved using the corresponding 2D inverse discrete wavelet transform.

Results:

The processed images show that the proposed method can remove the gridline signal efficiently while maintaining the image details. The spectra of a 1D Fourier transform of the processed images demonstrate that, compared with some existing gridline removal methods, the proposed method has better information preservation after the removal of the gridline artifacts. Additionally, the performance speed is relatively high.

Conclusions:

The experimental results demonstrate the efficiency of the proposed method. Compared with some existing gridline removal methods, the proposed method can preserve more information within an acceptable execution time.
Equalization of loudspeaker response using balanced model truncation
Authors: Li Xiansheng , Cai Zhibo , Zheng Chengshi , Li Xiaodong
Published: March 2015

Traditional loudspeaker equalization algorithms cannot decide the order of an equalizer before the whole equalization procedure has been completed. Designers have to try many times before they determine a proper order of the equalization filter. A method which solves this drawback is presented for loudspeaker equalization using balanced model truncation. The order of the equalizer can be easily decided using this algorithm and the error between the model and the loudspeaker can also be readily controlled. Examples are presented and the performance of the proposed method is discussed with comparative experiments.
Underwater acoustic signals induced by intense ultrashort laser pulse
Authors: Brelet Yohann , Jarnac Amélie , Carbonnel Jérôme , André Yves-Bernard , Mysyrowicz André , Houard Aurélien , Fattaccioli Dominique , Guillermin Régine , Sessarego Jean-Pierre
Published: March 2015

Acoustic signals generated in water by terawatt (TW) laser pulses undergoing filamentation are studied. The acoustic signal has a very broad spectrum, spanning from 0.1 to 10 MHz and is confined in the plane perpendicular to the laser direction. Such a source appears to be promising for the development of remote laser based acoustic applications.
Beliefs of Chinese Physical Educators on Teaching Students With Disabilities in General Physical Education Classes
Authors: Wang Lijuan , Qi Jing , Wang Lin
Published: March 2015

This study examined the behavioral beliefs of physical education (PE) teachers about teaching students with disabilities in their general PE (GPE) classes and to identify the factors that contribute to their beliefs. A total of 195 PE teachers from a region in eastern China were surveyed. Results of the Physical Educators’ Attitudes Toward Teaching Individuals With Disabilities-III survey indicate that although some teachers felt that including students with disabilities in GPE classes provides benefit for them, they were concerned about the practical difficulties of teaching students with disabilities in GPE classes, the lack of support, and the possible rejection of students with disabilities by their peers. Moreover, the behavioral beliefs of teachers vary according to the disability conditions of the students. Results show that there is no significant effect of demographic factors on the beliefs of PE teachers. Quality of experience predicts positive beliefs. The study has important implication for teacher training, provision of equipment, and support from teacher assistants.
Materials that couple sensing, actuation, computation, and communication
Authors: McEvoy M. A. , Correll N.
Published: March 2015

Adding autonomy to materials science

Shape-memory alloys can alter their shape in response to a change in temperature. This can be thought of as a simple autonomous response, albeit one that is fully programmed at the time of fabrication. It is now possible to build materials or combinations of materials that can sense and respond to their local environment, in ways that might also include simple computations and communication. McEvoy and Correll review recent developments in the creation of autonomous materials. They look at how individual abilities are added to a material and the current limitations in the further development of “robotic materials.”

Science
, this issue
10.1126/science.1261689
Woes for ‘exercise hormone’
Authors: Servick Kelly
Published: March 2015

Challenged antibody assays raise new questions about hoped-for obesity drug target.
A TRICK'n way to see the pioneer round of translation
Authors: Popp Maximilian W. , Maquat Lynne E.
Published: March 2015

Watching where and when individual messenger RNAs direct protein synthesis in live cells

[Also see Report by

Halstead
et al.

]
Substandard/Counterfeit Antimicrobial Drugs
Authors: Kelesidis Theodoros , Falagas Matthew E.
Published: March 2015

Substandard/counterfeit antimicrobial drugs are a growing global problem. The most common substandard/counterfeit antimicrobials include beta-lactams (among antibiotics) and chloroquine and artemisin derivatives (among antimalarials). The most common type of substandard/counterfeit antimicrobial drugs have a reduced amount of the active drug, and the majority of them are manufactured in Southeast Asia and Africa. Counterfeit antimicrobial drugs may cause increased mortality and morbidity and pose a danger to patients. Here we review the literature with regard to the issue of substandard/counterfeit antimicrobials and describe the prevalence of this problem, the different types of substandard/counterfeit antimicrobial drugs, and the consequences for the individuals and global public health. Local, national, and international initiatives are required to combat this very important public health issue.
Passive Immunotherapy with Dromedary Immune Serum in an Experimental Animal Model for Middle East Respiratory Syndrome Coronavirus Infection
Authors: Zhao Jincun , Perera Ranawaka A. P. M. , Kayali Ghazi , Meyerholz David , Perlman Stanley , Peiris Malik
Published: March 2015

Middle East respiratory syndrome (MERS) is a highly lethal pulmonary infection. Serum from convalescent MERS patients may provide some benefit but is not readily available. In contrast, nearly all camels in the Middle East have been infected with MERS-CoV. Here, we show that sera obtained from MERS-immune camels augment the kinetics of MERS-CoV clearance and reduce the severity of pathological changes in infected lungs, with efficacy proportional to the titer of MERS-CoV-neutralizing serum antibody.

IMPORTANCE
Middle East respiratory syndrome, caused by a coronavirus, is highly lethal, with a case fatality rate of 35 to 40%. No specific therapy is available, and care is generally supportive. One promising approach is passive administration of sera from convalescent human MERS patients or other animals to exposed or infected patients. The vast majority of, if not all, camels in the Middle East have been infected with MERS-CoV, and some contain high titers of antibody to the virus. Here, we show that this antibody is protective if delivered either prophylactically or therapeutically to mice infected with MERS-CoV, indicating that this may be a useful intervention in infected patients.
The role of mucilage in the germination of Leptocereus scopulophilus (Cactaceae) seeds from Pan de Matanzas, Cuba
Authors: Barrios Duniel , Flores Joel , González-Torres Luis R. , Palmarola Alejandro
Published: March 2015

Studies of seed mucilage in a number of species suggest that it has multiple ecological roles dependent on species and their environmental context. We evaluate whether mucilage facilitates seed germination for Leptocereus scopulophilus Areces, as well as whether light conditions influence the effect of the mucilage. Three combined treatments of light conditions: (1) shade (10% of sunlight), (2) semi-shade (30% of sunlight), and (3) full light exposure (100% of sunlight), and two seed types (with mucilage and washed) were used. Germinability was affected by light conditions but no effect of mucilage was found; higher germination occurred in shade than in semi-shade conditions. There was no germination in full light conditions. Germination rate (T50) was not affected by light conditions or by the mucilage, or the interaction of both factors. Minimal time to germination (Tmin) was affected by mucilage; seeds with mucilage germinated 2 days later than washed seeds. Thus, facilitation for imbibition of water does not occur in L. scopulophilus seeds. Perhaps the presence of mucilage in seeds of this species serves other purposes such as seed adhesion to soil or to deter predators.
Some non-equilibrium invariant states for the asymmetric exclusion QMS at level one
Authors: García Julio C. , Guerrero-Poblete Fernando
Published: March 2015

We review the Asymmetric Exclusion QMS in the light of new results, taking as a starting point the dynamics in the one particle space. We give a condition for the Asymmetric Exclusion QMS to be conservative, prove that an invariant state is necessarily diagonal and give conditions on eigenvalues of such an invariant state. We also give, a necessary condition to annul the generator of the predual semigroup; with this and the weighted detailed balance condition, we propose a method to construct some non-equilibrium invariant states.
Buckling of Graphene Embedded in Polymer Matrix Under Compression
Authors: Lin F. , Xiang Y. , Shen H.-S.
Published: March 2015

Understanding the mechanical behaviors of graphene under different stress states is crucial to their applications. Comparing with the bucking behavior of free standing graphene under compression, the monolayer graphene embedded in the polymer matrix has a higher critical buckling load and smaller atomic length scale wavelengths as well as buckling amplitudes. In this paper, the molecular dynamics (MD) method is adopted to study the buckling behaviors of embedded graphene under uniaxial compression. Two MD models are built, namely the hybrid MD/continuum nanomechanics model and the full MD model. Periodical boundary conditions are applied in the MD simulations. Graphene sheets with different aspect ratios are considered and it is observed that the critical buckling strain of graphene sheets embedded in polymer matrix is independent of their aspect ratios. The current simulation results match well with the reported experimental results. Furthermore, it is demonstrated that the current simulation method can produce clear buckling shapes, which are difficult to observe in nanoscale experiments.
Benzimidazole derivatives as anticancer drugs: A theoretical investigation
Authors: Farmanzadeh Davood , Najafi Meysam
Published: March 2015

In this study the anticancer properties of a series of benzimidazole drugs 1–9 and their interactions with DNA base pairs were investigated. The obtained theoretical results for anticancer activity of synthesized drugs 1–5 were compared to corresponding published experimental results. Based on theoretical and published experimental anticancer scales, drugs 2 and 4 have higher anticancer activity among drugs 1–5. Obtained results reveal that interactions of studied drugs with DNA base pairs are energetically favorable and solvent and electric field (EF) increase the binding energies in comparison to gas phase. The binding energies of drugs 2, 5 and 4 with DNA base pairs are more negative than corresponding values for drug 1. We propose the novel drugs 6–9 to synthesize with higher anticancer activity. Results show that binding energies of novel drugs 6–9 were more negative than drugs 1–5. Finally, results show that chemical potential, electrophilicity and global hardness can be considered as admissible theoretical anticancer indexes for studied benzimidazole drugs 1–9.
Rank-deficient spectral factorization and wavelets completion problem
Authors: Ephremidze L. , Spitkovsky I. , Lagvilava E.
Published: March 2015

A simple constructive proof of polynomial matrix spectral factorization theorem is presented in the rank-deficient case. It is then used to provide an elementary solution to the wavelets completion problem.
A dual pair for free boundary fluids
Authors: Gay-Balmaz François , Vizman Cornelia
Published: March 2015

We construct a dual pair associated to the Hamiltonian geometric formulation of perfect fluids with free boundaries. This dual pair is defined on the cotangent bundle of the space of volume preserving embeddings of a manifold with boundary into a boundaryless manifold of the same dimension. The dual pair properties are rigorously verified in the infinite-dimensional Fréchet manifold setting. It provides an example of a dual pair associated to actions that are not completely mutually orthogonal.
An Improvement on the Delsarte-Type LP-Bound with Application to MUBs
Authors: Matolcsi M. , Weiner M.
Published: March 2015

The linear programming (LP) bound of Delsarte can be applied to several problems in various branches of mathematics. We describe a general Fourier analytic method to get a slight improvement on this bound. We then apply our method to the problem of mutually unbiased bases (MUBs) to prove that the Fourier family F(a; b) in dimension 6 cannot be extended to a full system of MUBs.
Quantum Simulation of the Dirac Particle
Authors: Ostrowski Marcin
Published: March 2015

In this paper, we examine whether a quantum computer can efficiently simulate time evolution of the Dirac particle. We consider a Gaussian wave packet scattered by a step potential. We compare the results obtained from a quantum algorithm with the results of classical simulations (Cayley's method) and analytical calculations.
IN VITRO ANTI-VIRAL ACTIVITY OF ETHANOL EXTRACT FROM IXERIS CHINENSIS AGAINST INFLUENZA VIRUS
Authors: Yang Chih-Hsueh , Tan Duen-Huey , Jong Ting-Ting , Wen Chi-Luan , Hsu Shih-Lan , Chang Poa-Chun
Published: March 2015

Ixeris chinensis (Thunb.) Nakai (I. chinensis), a commonly used Taiwanese herbal medicine that exhibits various pharmacological properties, has been used to prepare a traditional Chinese medicine composition for prevention and treatment of influenza A virus infection. In this study, the in vitro anti-influenza virus activity of I. chinensis was evaluated. The result showed that the 50% ethanol extract from I. chinensis significantly increased the viability of the DF-1 cells that were infected with the H6N1 influenza virus. This extract also suppressed the synthesis of viral nucleoprotein (NP) and inhibited the growth of the H6N1 virus in DF-1 cells. Further, the 50% ethanol extract from I. chinensis inhibited the neuraminidase (NA) activity of the H6N1 virus. These findings provide important information for exploitation and utilization of I. chinensis in treatment of influenza infection.
CASE REPORT: A PRIMARY SPLENIC FIBROSARCOMA WITH HEPATIC METASTASIS IN A CAPTIVE KOALA (PHASCOLARCTOS CINEREUS)
Authors: Wang Fun-In , Yu Jane-Fang , Chen Jiun-Liang , Lai Sera Yen-Shuei , Jeng C.-R. , Liu C.-H. , Chang P.-H. , Pang Victor F.
Published: March 2015

A 11-year-old female Koala showed anorexia, lethargy and weakness. Hematology, blood chemistry and urinalysis were non-specific. Computed tomography (CT) revealed ascites and masses within the abdomen, and the volumes of some masses increased 20% during a 10-week period. At necropsy, there was 115 mL of clear ascites, and visceral lesions were located mainly in the spleen and liver. The spleen was diffusely enlarged by infiltrative white firm neoplastic tissue with irregularly protuberant nodules, of 0.2 to 5 cm, that had totally effaced the parenchyma. The liver contained multiple random scattered softer nodules, of 0.2 to 2.0 cm, some of which were protruding. One nodule of < 1 cm was noted on the mesentery. Histologically, the neoplasm was composed of a low cellularity of elongated fusiform cells distributed amongst an abundant collagenous matrix. Tumor cells were stained positive intracytoplasmically for vimentin and negative for α-smooth muscle actin. This fibrosarcoma (FS) likely originated from the spleen, with secondary metastasis to the liver, from which via transcoelomic implantation spread to the diaphragm and mesentery. This is considered a rare report of primary splenic FS in a captive koala.
Synthesis of Iron Oxide Nanoclusters with Enhanced Magnetization and Their Applications in Pulsed Magneto-Motive Ultrasound Imaging
Authors: Yoon Ki Youl , Mehrmohammadi Mohammad , Borwankar Ameya , Emelianov Stanislav Y. , Johnston Keith P.
Published: March 2015

We report here a facile synthetic approach for preparing water-soluble Fe 3 O 4 nanoparticle (NP) clusters with tunable size distribution and magnetic properties. The primary NP sizes were controlled by tuning the nucleation and growth rates with temperature and ligand concentration while the nanocluster sizes were manipulated by controlling interparticle interactions. We have investigated the size control of clusters as well as individual primary NPs via dynamic light scattering (DLS) analysis and transmission electron microscopy (TEM). Superconducting quantum interference device (SQUID) was used to measure the magnetic properties of Fe 3 O 4 NP for determining the effect of size distribution at room temperature. These water dispersible NP clusters can be utilized in various biomedical applications. In this study, we demonstrated the application of synthesized nanoclusters to enhance imaging contrast a novel ultrasound-based imaging modality, pulsed magneto-motive ultrasound (pMMUS) imaging. Our results indicated that by using the NP clusters with enhanced magnetic properties, the pMMUS signal increased significantly which is an essential requirement for further development of in vivo pMMUS imaging.
Preparation of Monodisperse ColloidalZnONanoparticles and their Optical Properties
Authors: Yang Chong , Tang Limei , Li Qingsong , Bai Ailing , Wang Yanqiu , Yu Yingmin
Published: March 2015

Monodisperse colloidal zinc oxide ( ZnO ) nanospheres with a narrow size distribution were synthesized via a developed two-stage solution method. We controlled the size of the as-synthesized ZnO nanoparticles by varying the amount of ZnO /ethanol suspension added. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) revealed that the diameter of the as-synthesized ZnO nanoparticles was in the range of 60–140 nm with a polydispersity index less than 5%. On high-resolution TEM images, we clearly observed that the ZnO nanospheres were actually composed of tiny ZnO subunits, several nanometers in size. Powder X-ray diffraction and TEM-selected area electron diffraction analysis showed that the spheres consisted of polycrystalline nanoparticles. The size of the subunits, which was confirmed by ultraviolet (UV)-visible spectroscopy, increased as the amount of ZnO /ethanol suspension added was decreased. A UV emission at about 374 nm was observed, and this emission of ZnO nanoparticles is found to depend on particle size due to the confinement effect. A red emission at about 651 nm, which has been reported for undoped ZnO , appeared due to the excess oxygen on the particles from O – H or C = O groups. The intensity of the red emission increased as the relative oxygen content increased. The formation mechanism of such ZnO nanospheres was also considered.
Using contaminated tools fuels outbreaks of BananaXanthomonas wilt: An optimal control study within plantations using Runge–Kutta fourth-order algorithms
Authors: Nannyonga B. , Luboobi L. S. , Tushemerirwe P. , Jabłońska-Sabuka M.
Published: March 2015

Optimal control theory is applied to a system of ordinary differential equations modeling banana Xanthomonas wilt within plantations. The objective is to reduce the proportion of infected plants by use of controls representing two types of preventive methods: vector and contaminated tool prevention. The optimal controls are characterized in terms of the optimality system, which is solved analytically and numerically for several scenarios.
Fuzzy comprehensive evaluation model for construction risk analysis in urban subway
Authors: Dai Chun-Quan , Zhao Zeng-Hui
Published: March 2015

On the basis of expert questionnaire and the relevant specification, multi-factors influencing weight matrix was constructed by Analytic Hierarchy Process (AHP) improved in transfer matrix algorithm, and influential factors were fuzzy classified to construct the fuzzy evaluation matrix by using trapezoidal fuzzy membership function. Fuzzy evaluation analysis was carried out through multistage fuzzy comprehensive evaluation method, and verified in combination with engineering construction condition of shallow buried tunnel with large span of Zhongshan Park Station in Qingdao Metro, and four kinds of risk control schemes were established and compared on the analysis of tunnel construction risk. Results show that the model was feasible and the improved construction scheme was very effective to reduce the construction risk.
Multiple Reflection Effect on Spin-Transfer Torque Dynamics in Spin Valves with a Single or Dual Polarizer
Authors: Zhu Weiwei , Zhang Zongzhi , Zhang Jianwei , Liu Yaowen
Published: March 2015

In this paper, spin-dependent multiple reflection effect on spin-transfer torque (STT) has been theoretically and numerically studied in a spin valve nanopillar with a single or dual spin-polarizer. By using a scattering matrix method, we formulate an analytical expression of STT that contains the multiple interfacial reflection effect. It is found that the multiple reflections could enhance the STT efficiency and reduce the critical switching current. The STT efficiency depends on the spin polarization of both the free layer and polarizer. In the nanopillars with a dual spin polarizer, the multiple reflections would cause an asymmetric frequency dependence on the applied current, albeit exactly the same parameters are used in all three ferromagnetic layers, indicating that the frequency in the negative current varies much faster than that in the positive case.
A Runtime FPGA Placement and Routing Using Low-Complexity Graph Traversal
Authors: Ferreira Ricardo , Rocha Luciana , Santos André G. , Nacif José A. M. , Wong Stephan , Carro Luigi
Published: March 2015

Dynamic Partial Reconfiguration (DPaR) enables efficient allocation of logic resources by adding new functionalities or by sharing and/or multiplexing resources over time. Placement and routing (P&R) is one of the most time-consuming steps in the DPaR flow. P&R are two independent NP-complete problems, and, even for medium size circuits, traditional P&R algorithms are not capable of placing and routing hardware modules at runtime. We propose a novel runtime P&R algorithm for Field-Programmable Gate Array (FPGA)-based designs. Our algorithm models the FPGA as an implicit graph with a direct correspondence to the target FPGA. The P&R is performed as a graph mapping problem by exploring the node locality during a depth-first traversal. We perform the P&R using a greedy heuristic that executes in polynomial time. Unlike state-of-the-art algorithms, our approach does not try similar solutions, thus allowing the P&R to execute in milliseconds. Our algorithm is also suitable for P&R in fragmented regions. We generate results for a manufacturer-independent virtual FPGA. Compared with the most popular P&R tool running the same benchmark suite, our algorithm is up to three orders of magnitude faster.
Revisiting the NaCl cotransporter regulation by with-no-lysine kinases
Authors: Bazúa-Valenti Silvana , Gamba Gerardo
Published: March 2015

The renal thiazide-sensitive Na+-Cl− cotransporter (NCC) is the salt transporter in the distal convoluted tubule. Its activity is fundamental for defining blood pressure levels. Decreased NCC activity is associated with salt-remediable arterial hypotension with hypokalemia (Gitelman disease), while increased activity results in salt-sensitive arterial hypertension with hyperkalemia (pseudohypoaldosteronism type II; PHAII). The discovery of four different genes causing PHAII revealed a complex multiprotein system that regulates the activity of NCC. Two genes encode for with-no-lysine (K) kinases WNK1 and WNK4, while two encode for kelch-like 3 (KLHL3) and cullin 3 (CUL3) proteins that form a RING type E3 ubiquitin ligase complex. Extensive research has shown that WNK1 and WNK4 are the targets for the KLHL3-CUL3 complex and that WNKs modulate the activity of NCC by means of intermediary Ste20-type kinases known as SPAK or OSR1. The understanding of the effect of WNKs on NCC is a complex issue, but recent evidence discussed in this review suggests that we could be reaching the end of the dark ages regarding this matter.
Therapeutic value of spinal cord stimulation in irritable bowel syndrome: a randomized crossover pilot study
Authors: Lind Göran , Winter Jaleh , Linderoth Bengt , Hellström Per M.
Published: March 2015

Irritable bowel syndrome (IBS) is characterized by abdominal pain and changed bowel habits. Spinal cord stimulation (SCS) has been used for treatment of chronic pain syndromes. Animal studies have shown SCS to reduce the reaction to colonic balloon distension, known to be increased in IBS patients. To elucidate the potential for SCS as treatment for IBS, a pilot study was performed. Ten IBS patients (age 26–56 yr) were recruited. A SCS system with a four-polar electrode was implanted at the T5-T8 level. After a 2-wk run-in, a randomized, crossover design SCS during 6 wk was compared with no stimulation, with an ensuing stimulation period for 12 wk; total study period 28 wk. Patients recorded pain level, pain attacks, diarrheas, and global quality of life in a diary. At end of the study patients could choose to retain their SCS system or have it removed. Nine patients completed the whole trial. During stimulation periods the median pain scores were significantly reduced from visual analogue scale (VAS) 7 (4–8) to 3 (2.5–7) and to 4 (2–6) during early and late stimulation periods, respectively ( P < 0.03–0.04). Pain attacks were numerically reduced. A few patients reported reduced number of diarrheas. After study termination, six patients chose to retain their SCS system. To conclude, SCS is a minimally invasive treatment option for pain in IBS. With SCS the pain level was reduced though with merely a trend for number of attacks and diarrheas. The efficacy of SCS in IBS pain indicates a possible usefulness in other painful bowel disorders.
Optimization of Cutter Geometric Parameters in End Milling of Titanium Alloy Using the Grey-Taguchi Method
Authors: Ren Junxue , Zhou Jinhua , Wei Jianwei
Published: March 2015

Further progress in control of manufacturing process and performance depends on the innovativeness of machine tools after cutting parameter optimization. This paper presents a multiobjective optimization of cutter geometric parameters in end milling of Ti-5Al-5Mo-5V-1Cr-1Fe titanium alloy via Taguchi method in integration with grey relational analysis. Sixteen experiments are conducted by the Taguchi method and analyzed based on the signal-to-noise ratio. Then, the multiple objectives optimization is successfully converted to a single objective optimization of the grey relational grade by the grey relational analysis. The cutter geometric parameters, namely, fluting rake angle, gash angle, helix angle, gash rake angle, and pitch angle difference, are optimized to minimize cutting force, surface roughness, and the acceleration. According to the results of Analysis of variance, the order of importance for the control factors to the multiperformance characteristics, in sequence, is helix angle, gash angle, gash rake angle, pitch angle difference, and fluting rake angle. Experimental results indicate that the multiperformance characteristics can be improved effectively with the grey-Taguchi method.
Numerical Simulation of Transient Flows around a 3D Pitching Hydrofoil
Authors: Wu Qin , Huang Biao , Wang Guoyu
Published: March 2015

The objective of this paper is to investigate the hydrodynamic characteristics of the transient flows around a 3D pitching hydrofoil via numerical studies, where the effects of tunnel wall boundary layer and gap flows are considered. Simulations are performed using an unsteady Reynolds Average Navier-Stokes solver and the k-ω SST turbulence model, coupled with a two-equation γ-Reθ transition model. Hydrodynamic forces and flow structures are compared to the results with the equivalent 2D computations. During the upward pitching stage, the transition phenomenon is accurately captured by both the 2D and 3D simulations. The slightly lower lift and suction side loading coefficients predicted by the 3D simulation are due to the pressure effects caused by the tip gap flow. During the dynamic stall stage, the 2D case exhibits a clear overshoot on the hydrodynamic force coefficients and the 3D simulation results better agree with the experimental results. During the downward pitching stage, the flow transitions back to laminar. As for the effect of gap flow and the wall boundary condition, the gap flow causes disturbances to the formation and development of the vortex structures, resulting in the complex distribution of the three-dimensional streamlines and the particle path.
Torque-Controlled Adaptive Speed Control on a CNC Marble Saw Machine
Authors: Simsir Ugur
Published: March 2015

Although CNC marble saw machines can automatically cut marble slabs to desired dimensions, saw speed and feed rate are selected by operator according to stone parameters, features of the saw, and its immersion depth. If the feed rate is selected lower than the optimal value, there will be time-loss and capacity deficiencies or if it is selected faster, cutting quality will decrease, spindle motor will draw more current, and saw blade will corrode faster. While cutting especially thick materials, saw may be stacked in the stone, cutting quality may be impaired, saw blade may be abraded earlier, precision quality may go down because of increase in measurement errors, and machine may be damaged with the increase in vibrations when improper feed rates are selected. Because of nonhomogeneity of the slabs and deterioration of the saw blade, operator cannot determine a persistent feed rate. This study is targeted to find saw speeds according to saw diameter and optimum feed rate by means of limiting vibrations and current drawn from saw motor and torque accordingly in order to increase working performance of CNC marble saw machines. Thanks to adaptive adjustment of feed rate, one can save on material as well as time, labour, and cost by making use of optimum energy.
An Improved General Motor Car-Following Model considering the Lateral Impact
Authors: Tao Pengfei , Hu Hongyu , Gao Zhenhai , Li Zhihui , Song Xianmin , Xing Yan , Wei Fulu , Duan Yuzhou
Published: March 2015

We improve the typical GM car-following model. In order to describe the impacts of the lateral offset between the vehicles in car-following state, this paper proposes time distance to measure the drivers' attention of driving environment and uses generalized expectation headway to describe the ideal driving state of the driver. Take the difference between the actual and expected headway as the important standard for driver to decide whether to speed up or slow down. Then take the drivers' attentions and the expected headway as the decision-making factors, and consider them while revising the GM car-following model. The numerical simulation shows the improved GM model conforms to the general driving behavior, enhances the function of the typical model, and strengthens the model stability.
Extracting Backbones from Weighted Complex Networks with Incomplete Information
Authors: Qian Liqiang , Bu Zhan , Lu Mei , Cao Jie , Wu Zhiang
Published: March 2015

The backbone is the natural abstraction of a complex network, which can help people understand a networked system in a more simplified form. Traditional backbone extraction methods tend to include many outliers into the backbone. What is more, they often suffer from the computational inefficiency—the exhaustive search of all nodes or edges is often prohibitively expensive. In this paper, we propose a backbone extraction heuristic with incomplete information (BEHwII) to find the backbone in a complex weighted network. First, a strict filtering rule is carefully designed to determine edges to be preserved or discarded. Second, we present a local search model to examine part of edges in an iterative way, which only relies on the local/incomplete knowledge rather than the global view of the network. Experimental results on four real-life networks demonstrate the advantage of BEHwII over the classic disparity filter method by either effectiveness or efficiency validity.
Epithelial-Mesenchymal Transition in Keratocystic Odontogenic Tumor: Possible Role in Locally Aggressive Behavior
Authors: Zhong Wen-Qun , Chen Gang , Zhang Wei , Ren Jian-Gang , Wu Zhong-Xing , Zhao Yi , Liu Bing , Zhao Yi-Fang
Published: March 2015

The aim of this study is to clarify whether epithelial-mesenchymal transition (EMT) is involved in the pathogenesis and development of keratocystic odontogenic tumor (KCOT). The expression levels of EMT-related proteins and genes in normal oral mucosa (OM), radicular cyst (RC), and KCOT were determined and compared by real-time quantitative PCR and immunohistochemistry. Our data showed that the expression of epithelial markers E-cadherin and Pan-cytokeratin was significantly downregulated in KCOT with upregulation of mesenchymal markers N-cadherin compared to OM and RC. Importantly, TGF-β, a potent EMT inducer, and Slug, a master transcription factor, were also found highly expressed in KCOT. In addition, the results from Spearman rank correlation test and clustering analysis revealed the close relationship between Slug and MMP-9, which was further evidenced by double-labeling immunofluorescence that revealed a synchronous distribution for Slug with MMP-9 in KCOT samples. All the data suggested EMT might be involved in the locally aggressive behavior of KCOT.