bluuebunny/crossref_metadata_2025 huggingface dataset:
Cold Flow Computations for the Diffuser-Combustor Section of an Industrial Gas Turbine
Authors: Zhou Dadong , Wang Ting , Ryan William R.
Published: February 2015

In the first part of a multipart project to analyze and optimize the complex three-dimensional diffuser-combustor section of a highly advanced industrial gas turbine under development, a computational fluid dynamics (CFD) analysts has been conducted. The commercial FEA code I-DEAS was used to complete the three-dimensional solid modeling and the structured grid generation. The flow calculation was conducted using the commercial CFD code PHOENICS. The multiblock method was employed to enhance computational capabilities. The mechanisms of the total pressure losses and possible ways to enhance efficiency by reducing the total pressure losses were examined. Mechanisms that contribute to the nonuniform velocity distribution of flow entering the combustor were also identified. The CFD results were informative and provided insight to the complex flow patterns in the reverse flow dump diffuser, however, the results are qualitative and are useful primarily as guidelines for optimization as opposed to firm design configuration selections.
Experimental Analysis of a Small Prototype of Peripheral Turbine for Decompression of Natural Gas
Authors: Bartolini Carlo M. , Salvi Danilo
Published: February 2015

In most cases, methane distributed through pipeline networks is decompressed in substation through the use of throttling valves.

An alternative process for decompressing natural gas consists of using turboexpanders: as the gas moves through the machine, the energy is removed from the fluid by the reduction in pressure and temperature; it’s then converted to mechanical energy by means of a rotor; the mechanical energy is transferred to the shaft and then converted to electrical energy.

This paper illustrates how a part of the energy lost through decompression can be recovered by means of peripheral turbines. These non-conventional turboexpanders can handle a range of applications, characterized by high expansion ratios and low flow rates, which traditional movers haven’t covered because their use wouldn’t be economically feasible.

Peripheral turbines offer specific advantages as prime movers whenever and wherever smaller mass flows and high expansion ratios are involved. Moreover, the presence of high pressure coefficients and low specific speeds support the choice of this mover in those cases which demand low level power at low revolutions from energy sources under high pressure. On the other hand, one negative aspect is that the level of isentropic efficiency is rather low. Nevertheless, owing to the small overall dimensions of the peripheral turbine, the mover can be usefully applied in a modular construction system, in which a number of machines can be assembled, either in series or in parallel, without an appreciable increase in price. The fact that the units are modular makes the system extraordinary versatile and adaptable.

In order to verify the technical feasibility of the project, detailed engineering was performed for a hypothetical pilot plant, based on data for a specific gas distribution network. Then a feasibility economic study was performed for the pilot plant. The evaluation of the pay back period and the NPV demonstrate the validity of the investment.
Economics of Gas Turbine Inlet Air Cooling System for Power Enhancement
Authors: Utamura Motoaki , Nishimura Yoshio , Ishikawa Akira , Ando Nobuo
Published: February 2015

A cost estimate method is presented, which enables to compare inlet air cooling system for power enhancement of combustion turbine with other power generation system. A new energy conversion index is developed which arranges system design parameters in a dimensionless form and also exhibits running cost. It is suggested that the inlet air cooling system is equivalent to simple cycle or pumped storage in view of the dimensionless running cost. Next, a cost diagram relating capital cost to power generation cost is presented also in non-dimensional form, which could provide a measure to examine investment worth for a power producer. Moreover, cooling effectiveness as function of cooled inlet air temperature is investigated using specific thermal energy. It is revealed that cooling beyond dew point requires a larger thermal energy per electric energy produced and thus less economical unless the price of electricity depends on electricity demand.
A Fully Enhanced Gas Turbine for Surface Ships
Authors: Janes Jack
Published: February 2015

Clearly, the advanced gas turbine has center stage in the world for converting fuel to work. The power and efficiency delivered by the advanced gas turbine have made it the predominant prime mover in the air, and increasingly so on land and sea. This paper explores the full potential offered for marine applications by the advanced gas turbine, a potential that is fully enhanced by use of available engineering options that are external to the gas generator. The enhancement options are: 1) intercooling 2) thermal recuperation 3) steam injection 4) reheat 5) closed loop cooling 6) catalytic partial oxidation 7) water recovary. Of the options studied reheat involves a unique approach. Reheat is postulated to be accomplished with a new simplified technique. An autoignitable hydrogen-rich fuel is injected into the air path through the cooling passages and from the trailing edge of blades and vanes of the law pressure turbine, reheating the air prior to entry into the free power turbine.
Design and Performance of Low Heating Value Fuel Gas Turbine Combustors
Authors: Battista Robert A. , Feitelberg Alan S. , Lacey Michael A.
Published: February 2015

General Electric Company is developing and testing low heating value fuel gas turbine combustors for use in integrated gasification combined cycle power generation systems. This paper presents the results of a series of combustion tests conducted at the pilot scale coal gasification and high temperature desulfurization system located at GE Corporate Research and Development in Schenectady, New York. Tests were performed in a modified GE MS6000 combustor liner operating at a pressure of 10 bar and over a wide load range (combustor exit temperatures from 760 to 1400°C).

The primary objective of these tests was to compare and contrast the performance (emissions, flame stability, and combustor liner temperatures) of six different low heating value fuel nozzle designs, representing three distinct nozzle concepts. With 2200 to 4600 ppmv NH3 in the fuel, the conversion of fuel NH3 to NOx was roughly independent of fuel nozzle type, and ranged from about 70% at low combustor exit temperatures to about 20% at high combustor exit temperatures. For all of the fuel nozzles, CO emissions were typically less than 5 ppmv (on a dry, 15% O2 basis) at combustor exit temperatures greater than 980°C. Significant differences in CO emissions were observed at lower combustor exit temperatures. Some differences in liner temperatures and flame stability were also observed with the different nozzles. In general, nozzles which produced lower CO emissions and greater flame stability had higher fuel swirl angles and resulted in higher combustor liner temperatures. The nozzle with the best overall performance (consisting of concentric axial air and fuel swirlers and an air cooled mixing cup) has been selected for use at a commercial site.
Gas Temperature Measurement in Internal Cooling Passages
Authors: Wang Z. , Ireland P. T. , Kohler S. T.
Published: February 2015

The gas temperature distribution is important in the measurement and the definition of heat transfer to various gas turbine cooling problems. This paper describes a novel technique which employs encapsulated thermochromic liquid crystals on a fine nylon mesh to give virtually instantaneous gas temperature distribution measurement. The hue value of the liquid crystal on the mesh was calibrated to the gas temperature for a broad response crystal, in the range of 22–40°C, and for a narrow band crystal from 29–31°C. Data processing issues specific to the application of liquid crystals on porous target are discussed and the results of investigations provided. Finally, applications that demonstrate the viability of the method are given.
Nonplanar Crack Growth Using the Surface Integral Method
Authors: Forth Scott C. , Keat William D.
Published: February 2015

A surface integral formulation, based on representing a crack as a distribution of force dipoles, has been developed for modeling the propagation of a three-dimensional nonplanar fracture. The minimum strain energy density, and maximum circumferential stress theories were used to determine the direction of crack growth. The extension of the fracture surface was based on the Paris Law for fatigue. Remeshing of the fracture during growth was accomplished by adding a ring of elements to the existing mesh at the conclusion of each increment of crack growth. This promoted the efficiency of the algorithm by eliminating the need to recalculate the entire coefficient matrix.

Use of the surface integral method, coupled with growth criteria, has yielded an accurate model for three-dimensional nonplanar crack growth under mixed mode loading conditions. The study of several penny-shaped precracks under mixed mode loading conditions produced the expected growth trajectory, and compared favorably to existing 2D, 3D, and experimental results found in the literature.
Reduction of NOx Formation by Water Sprays in Strained Two-Stage Flames
Authors: Li S. C. , Ilincic N. , Williams F. A.
Published: February 2015

Staged combustion can be employed to reduce the formation of CO and NOx, stabilize the flame, decrease the flame temperature and create better working conditions in gas turbine combustors. To help understand influences of partial premixing and addition of water on NOx formation, we study two-stage flames in a counterflow spray burner. This paper reports experimental and theoretical results concerning two-stage combustion in which one feed stream is composed of a fuel-rich mixture of methane and air and the other is air. Water sprays are added to the air stream. This two-phase laminar counterflow configuration exhibits a green premixed flame, a blue diffusion flame and a vaporization plane. All three are flat and parallel. The separation distances between them decrease with increasing equivalence ratio and strain rate. Flow visualization is provided through illumination by an argon ion laser sheet, velocity fields and spray structure are measured by a phase-doppler particle analyzer, concentration fields of major stable species are measured by gas chromatography of samples withdrawn from the flame, and temperature fields are measured by a thermocouple. Numerical integrations which employ a recent chemical-kinetic data base are performed to model the flame structure and NOx formation. Comparisons of experimental results with numerical predictions are made to test agreement. This work provides information on hydrocarbon combustion in both premixed flames and diffusion flames, indicates how NOx is formed in fuel-rich flames and suggests how the pollutants can be reduced.
Effects of Inlet Distortion on the Flow Field in a Transonic Compressor Rotor
Authors: Hah Chunill , Rabe Douglas C. , Sullivan Thomas J. , Wadia Aspi R.
Published: February 2015

The effects of circumferential distortions in inlet total pressure on the flow field in a low-aspect-ratio, high-speed, high-pressure-ratio, transonic compressor rotor are investigated in this paper. The flow field was studied experimentally and numerically with and without inlet total pressure distortion. Total pressure distortion was created by screens mounted upstream from the rotor inlet. Circumferential distortions of 8 periods per revolution were investigated at two different rotor speeds. The unsteady blade surface pressures were measured with miniature pressure transducers mounted in the blade. The flow fields with and without inlet total pressure distortion were analyzed numerically by solving steady and unsteady forms of the Reynolds-averaged Navier-Stokes equations. Steady three-dimensional viscous flow calculations were performed for the flow without inlet distortion while unsteady three-dimensional viscous flow calculations were used for the flow with inlet distortion. For the time-accurate calculation, circumferential and radial variations of the inlet total pressure were used as a time-dependent inflow boundary condition. A second-order implicit scheme was used for the time integration. The experimental measurements and the numerical analysis are highly complementary for this study because of the extreme complexity of the flow field. The current investigation shows that inlet flow distortions travel through the rotor blade passage and are convected into the following stator. At a high rotor speed where the flow is transonic, the passage shock was found to oscillate by as much as 20% of the blade chord, and very strong interactions between the unsteady passage shock and the blade boundary layer were observed. This interaction increases the effective blockage of the passage, resulting in an increased aerodynamic loss and a reduced stall margin. The strong interaction between the passage shock and the blade boundary layer increases the peak aerodynamic loss by about one percent.
Origin analysis of thermal neutron soft error rate at nanometer scale
Authors: Yamazaki Takashi , Kato Takashi , Uemura Taiki , Matsuyama Hideya , Tada Yoko , Yamazaki Kazutoshi , Soeda Takeshi , Miyajima Toyoo , Kataoka Yuji
Published: February 2015

Recently, thermal neutrons have been identified as a cause of soft errors in advanced electronic devices. To analyze the origin of such errors, dynamic secondary ion mass spectrometry (SIMS), time-of-flight (TOF)-SIMS, and three-dimensional atom probe (3DAP) methods have been used systematically. TOF-SIMS results showed that the existence region of 10B, the source of soft errors, has a high correlation to the existence region of W. Furthermore, 3DAP results for the sample extracted from the area near the W-plug revealed high 10B concentration at the W-plug.
Altering Shank–Rear-Foot Joint Coupling During Gait With Ankle Taping in Patients With Chronic Ankle Instability and Healthy Controls
Authors: Herb C. Collin , Chinn Lisa , Hertel Jay
Published: February 2015

Context:

Lateral ankle sprain (LAS) is one of the most common injuries in active individuals. Chronic ankle instability (CAI) is a condition that commonly occurs after LAS and is associated with long-term disability and a high risk of multiple ankle sprains. Ankle taping is a commonly used intervention for the prevention of ankle sprains.

Objective:

To analyze the ankle-joint coupling using vector coding during walking and jogging gait with the application of ankle tape and without ankle tape in young adults with and without CAI.

Design:

Observational laboratory study design. Patients walked and jogged on an instrumented treadmill while taped and not taped. Fifteen strides for each subject were collected and analyzed using a vector-coding technique to compare magnitude coupled motion, ratio of coupled motion, and the variability (VCV) within groups. Within-group means and 90% confidence intervals (CI) were compared between the taped and nontaped condition, and where the CIs did not overlap was considered significant.

Setting:

A 12-camera 3D motion-capture system with instrumented treadmill.

Patients:

12 patients with CAI and 11 healthy controls.

Main Outcome Measures:

Magnitude to coupled motion, ratio of coupled motion, and the VCV of shank–rear-foot joint coupling.

Results:

Magnitude of coupled motion and VCV were significantly lower in the taped condition than in the nontaped condition in both groups. Magnitude differences were identified near initial contact during walking and during swing phase of jogging. VCV differences were identified throughout the gait cycle at both walking and jogging. No differences were identified in theta between tape and nontaped conditions.

Conclusions:

A decrease in the magnitude of coupled motion and VCV may represent a protective mechanism of ankle taping in CAI and healthy patients during gait.
TERT
promoter mutations and telomerase reactivation in urothelial cancer
Authors: Borah Sumit , Xi Linghe , Zaug Arthur J. , Powell Natasha M. , Dancik Garrett M. , Cohen Scott B. , Costello James C. , Theodorescu Dan , Cech Thomas R.
Published: February 2015

The downstream effects of false promotion

Special DNA sequences at the ends of chromosomes, called telomeres, are replenished by a dedicated enzyme called telomerase. A subset of human tumors harbors mutations in the promoter region of the TERT gene, which codes for a subunit of telomerase. Borah
et al.
explored the downstream effects of TERT promoter mutations in cells derived from urothelial (urinary tract) cancers. The mutations were associated with aberrantly high levels of TERT mRNA, TERT protein and telomerase activity, and longer telomeres. A small study of clinical samples suggested that high levels of TERT mRNA may be a marker of more aggressive urothelial cancers.

Science
, this issue p.
1006
Glacial cycles drive variations in the production of oceanic crust
Authors: Crowley John W. , Katz Richard F. , Huybers Peter , Langmuir Charles H. , Park Sung-Hyun
Published: February 2015

Connecting orbit to the ocean floor

The amount of magma erupted at mid-ocean ridges can be modified by periodic ice ages that alter sea level. Crowley
et al.
analyzed high-resolution ocean depth data across the Australian-Antarctic ocean ridge (see the Perspective by Conrad). The results revealed 23-, 41-, and 100-thousand-year periodicity. These periods are similar to the well-known Milankovitch cycles associated with ice ages that are triggered by changes in Earth's orbit. Decreasing sea levels decrease the overlying pressure, thereby increasing the amount of erupted magma. The cyclic nature of glaciations and sea level creates a series of spaced topographic highs along the sea floor. Thus, Earth's atmosphere and mantle are coupled on a glacial time scale.

Science
, this issue p.
1237
; see also p.
1204
How climate influences sea-floor topography
Authors: Conrad Clinton P.
Published: February 2015

Sea-floor hills show the same periodicity as glacial cycles

[Also see Report by

Crowley
et al.

]
Complete Genome of Citrobacter freundii Siphophage Stevie
Authors: Shaw Justin P. , Aviles Medina Carlos A. , Chen Yi , Luna Adrian J. , Hernandez Adriana C. , Kuty Everett Gabriel F.
Published: February 2015

Citrobacter freundii
is an opportunistic pathogen responsible for many urinary tract infections acquired in hospitals and is thus a concern for public health.
C. freundii
phage Stevie might prove beneficial as a treatment against these infections. The complete genome of Stevie and its key features are described here.
Complete Genome of Salmonella enterica Serovar Typhimurium T5-Like Siphophage Stitch
Authors: Grover James M. , Luna Adrian J. , Wood Thammajun L. , Chamakura Karthik R. , Kuty Everett Gabriel F.
Published: February 2015

Salmonellosis, caused by Salmonella, is a leading cause of food poisoning worldwide. With the continuing rise of bacterial antibiotic resistance, efforts are focused on seeking new approaches for treatment of bacterial infections, namely, bacteriophage therapy. Here, we report the complete genome of S. Typhimurium siphophage Stitch.
Genome Sequencing of 10 Helicobacter pylori Pediatric Strains from Patients with Nonulcer Dyspepsia and Peptic Ulcer Disease
Authors: Nunes Alexandra , Rocha Raquel , Vale Filipa F. , Vieira Luís , Sampaio Daniel A. , Dias Ricardo , Gomes João P. , Oleastro Mónica
Published: February 2015

We present draft genome sequences of 10
Helicobacter pylori
clinical strains isolated from children. This will be important for future studies of comparative genomics in order to better understand the virulence determinants underlying peptic ulcer disease.
Complete Genome Sequence of Campylobacter jejuni YH001 from Beef Liver, Which Contains a Novel Plasmid
Authors: He Yiping , Yan Xianghe , Reed Sue , Xie Yanping , Chen Chin-Yi , Irwin Peter
Published: February 2015

Campylobacter jejuni
, commonly found in poultry and meat products, causes gastroenteritis in humans. Here, we report the complete genome sequence of a
C. jejuni
strain, YH001, isolated from retail beef liver. The genome is 1,712,361 bp and has a 30.5% G+C content and two plasmids of 46.5 kb and 4.4 kb.
Draft Genome Sequence of Streptomyces albus Strain NBRC 13014
T
, the Type Species of the Genus Streptomyces
Authors: Komaki Hisayuki , Ichikawa Natsuko , Oguchi Akio , Hamada Moriyuki , Tamura Tomohiko , Fujita Nobuyuki
Published: February 2015

Streptomyces albus
is the type species of the genus Streptomyces. Here, we report the draft genome sequence of S. albus strain NBRC 13014
T
. The genome contains at least seven orphan polyketide synthase and nonribosomal peptide synthetase gene clusters. The genome sequence will also serve as a valuable reference for Streptomyces taxonomy.
Draft Genome Sequence of Pseudomonas simiae Strain 2-36, an
In Vitro
Antagonist of Rhizoctonia solani and Gaeumannomyces graminis
Authors: Adam Zaky , Chen Qing , Xu Renlin , Diange Adolf E. , Bromfield Eden S. P. , Tambong James Tabi
Published: February 2015

Pseudomonas simiae
2-36, isolated from a field plot under long-term mineral fertilization, exhibited strong
in vitro
antagonistic activities against
Rhizoctonia solani
and
Gaeumannomyces graminis
. We report here the draft genome sequence of
Pseudomonas simiae
2-36, consisting of 6.4 Mbp with a 60.25% G+C content and 5,790 predicted protein-coding sequences.
The impact of an arts-based programme on the affective and cognitive components of empathic development
Authors: Zazulak Joyce , Halgren Camilla , Tan Megan , Grierson Lawrence E M
Published: February 2015

Medical education research demonstrates that empathic behaviour is amenable to positive change when targeted through educational programmes. This study evaluates the impact of an arts-based intervention designed to nurture learner empathy through the provision of facilitated visual literacy activities. Health Sciences students (N=19) were assigned to two learning groups: a group that participated in a visual literacy programme at the McMaster Museum of Art and a control group that participated in the normal Health Sciences curriculum. All participants completed an inter-reactivity index, which measures empathy on affective and cognitive levels, prior to and following the programme. Those individuals assigned to the visual literacy programme also completed open-ended questions concerning the programme's impact on their empathic development. The index scores were subjected to independent within-group, between-test analyses. There was no significant impact of the programme on the participants’ overall empathic response. However, sub-component analyses revealed that the programme had a significant positive effect on cognitive aspects of empathy. This finding was substantiated by the narrative reports. The study concludes that the affective focus of humanities-based education needs to be enhanced and recommends that learners are educated on the different components that comprise the overall empathic response.
Nature itself in a mirror space–time
Authors: Sharafiddinov Rasulkhozha S.
Published: February 2015

The unity of the structure of matter fields with flavor symmetry laws involves that the left-handed neutrino in the field of emission can be converted into a right-handed one and vice versa. These transitions together with classical solutions of the Dirac equation testify in favor of the unidenticality of masses, energies, and momenta of neutrinos of the different components. If we recognize such a difference in masses, energies, and momenta, accepting its ideas about that the left-handed neutrino and the right-handed antineutrino refer to long-lived leptons, and the right-handed neutrino and the left-handed antineutrino are short-lived fermions, we would follow the mathematical logic of the Dirac equation in the presence of the flavor symmetrical mass, energy, and momentum matrices. From their point of view, nature itself separates Minkowski space into left and right spaces concerning a certain middle dynamical line. Thereby, it characterizes any Dirac particle both by left and by right space–time coordinates. It is not excluded therefore that whatever the main purposes each of earlier experiments about sterile neutrinos, namely, about right-handed short-lived neutrinos may serve as the source of facts confirming the existence of a mirror Minkowski space–time.
Celastrol Induces Mitochondria-Mediated Apoptosis in Hepatocellular Carcinoma Bel-7402 Cells
Authors: Li Pei-Pei , He Wei , Yuan Ping-Fan , Song Sha-Sha , Lu Jing-Tao , Wei Wei
Published: February 2015

Celastrol is a natural terpenoid isolated from Tripterygium wilfordii, a well-known Chinese medicinal herb that presents anti-proliferative activities in several cancer cell lines. Here, we investigated whether celastrol induces apoptosis on hepatocellular carcinoma Bel-7402 cells and further explored the underlying molecular mechanisms. Celastrol caused a dose- and time-dependent growth inhibition and apoptosis of Bel-7402 cells. It increased apoptosis through the up-regulation of Bax and the down-regulation of Bcl-2 in Bel-7402 cells. Moreover, celastrol induced the release of cytochrome c and increased the activation of caspase-3 and caspase-9, suggesting that celastrol-induced apoptosis was related to the mitochondrial pathway. These results indicated that celastrol could induce apoptosis in Bel-7402 cells, which may be associated with the activation of the mitochondria-mediated pathway.
New black hole solutions of Einstein field equations and their Riemann curvature tensors
Authors: Ali Farhad
Published: February 2015

Here, we are going to discuss some new cases of cylindrically symmetric black hole solutions of Einstein field equations (EFEs). These are new solutions which we have not seen in the literature. We also listed their Riemann curvature tensors.
Degeneracy pressure of noncommutative fermions
Authors: Heydarnezhad S. , Soudmand M.
Published: February 2015

The free energy of an imperfect gas of nonrelativistic fermions in noncommutative space is calculated to 2-loop order and its zero and low temperature limits are derived. Implications on the degeneracy pressure of the system is discussed.
Dynamics of anisotropic collapsing spheres in Einstein Gauss–Bonnet gravity
Authors: Abbas G. , Zubair M.
Published: February 2015

This paper is devoted to investigate the dynamics of the self-gravitating adiabatic and anisotropic source in 5D Einstein Gauss–Bonnet gravity. To this end, the source has been taken as Tolman–Bondi model which preserve inhomogeneity in nature. The field equations, Misner–Sharp mass and dynamical equations have formulated in Einstein Gauss–Bonnet gravity in 5D. The junction conditions have been explored between the anisotropic source and vacuum solution in Gauss–Bonnet gravity in detail. The Misner and Sharp approach has been applied to define the proper time and radial derivatives. Further, these helps to formulate general dynamical equations. The equations show that the mass of the collapsing system increases with the same amount as the effective radial pressure increases. The dynamical system preserves retardation which implies that system under-consideration goes to gravitational collapse.
Neutrinoless double-beta decay: A probe of physics beyond the Standard Model
Authors: Bilenky S. M. , Giunti C.
Published: February 2015

In the Standard Model the total lepton number is conserved. Thus, neutrinoless double-β decay, in which the total lepton number is violated by two units, is a probe of physics beyond the Standard Model. In this review we consider the basic mechanism of neutrinoless double-β decay induced by light Majorana neutrino masses. After a brief summary of the present status of our knowledge of neutrino masses and mixing and an introduction to the seesaw mechanism for the generation of light Majorana neutrino masses, in this review we discuss the theory and phenomenology of neutrinoless double-β decay. We present the basic elements of the theory of neutrinoless double-β decay, our view of the present status of the challenging problem of the calculation of the nuclear matrix element of the process and a summary of the experimental results.
Quantization of emergent gravity
Authors: Yang Hyun Seok
Published: February 2015

Emergent gravity is based on a novel form of the equivalence principle known as the Darboux theorem or the Moser lemma in symplectic geometry stating that the electromagnetic force can always be eliminated by a local coordinate transformation as far as space–time admits a symplectic structure, in other words, a microscopic space–time becomes noncommutative (NC). If gravity emerges from U(1) gauge theory on NC space–time, this picture of emergent gravity suggests a completely new quantization scheme where quantum gravity is defined by quantizing space–time itself, leading to a dynamical NC space–time. Therefore the quantization of emergent gravity is radically different from the conventional approach trying to quantize a phase space of metric fields. This approach for quantum gravity allows a background-independent formulation where space–time and matter fields are equally emergent from a universal vacuum of quantum gravity.
On the Design of Social Voting Recommendation Applications
Authors: Tsapatsoulis Nicolas , Agathokleous Marilena , Djouvas Constantinos , Mendez Fernando
Published: February 2015

Voting Advice Applications (VAAs) are online tools that match the policy preferences of voters with the policy positions of political parties or candidates. Designed to enhance the political competence of citizens, VAAs have become increasingly popular and institutionally embedded in a growing number of European countries. While the traditional VAA relied on the stated position or academically coded position of parties/candidates, a recent innovation has been to introduce a social vote recommendation borrowing the basic principles of collaborative filtering. The latter takes advantage of the community of VAA users to provide a vote recommendation. This paper provides an overview of the social vote recommendation scheme and tackles three problems related to its optimal implementation in a real–world setting: (1) the number of samples required to train party models; (2) whether this number is affected by differences in characteristics between early users versus late users; and (3) whether generalizations can be derived across VAA applications in different countries. For our experiments we use three real VAA datasets based on elections in Greece 2012, Cyprus 2013 and Germany 2013. The corresponding datasets are made freely available to other researchers working in the areas of VAA and web based recommender systems.
A Novel Diversity-Based Semi-Supervised Learning Framework with Related Theoretical Analysis
Authors: Jiang Zhen , Zhan Yong-Zhao
Published: February 2015

We present a new co-training style framework and combine it with ensemble learning to further improve the generalization ability. By employing different strategies to combine co-training with ensemble learning, two learning algorithms, Sequential Ensemble Co-Learning (SECL) and Parallel Ensemble Co-Learning (PECL) are developed. Furthermore, we propose a weighted bagging method in PECL to generate an ensemble of diverse classifiers at the end of co-training. Finally, based on the voting margin, an upper bound on the generalization error of multi-classifier voting systems is given in the presence of both classification noise and distribution noise. Experimental results on six datasets show that our method performs better than other compared algorithms.
An Algorithm for Learning the Skeleton of Large Bayesian Network
Authors: Li Yanying , Yang Youlong , Wang Wensheng , Yang Wenming
Published: February 2015

It is well known that Bayesian network structure learning from data is an NP-hard problem. Learning a correct skeleton of a DAG is the foundation of dependency analysis algorithms for this problem. Considering the unreliability of the high order condition independence (CI) tests and the aim to improve the efficiency of a dependency analysis algorithm, the key steps are to use less number of CI tests and reduce the sizes of condition sets as many as possible. Based on these analyses and inspired by the algorithm HPC, we present an algorithm, named efficient hybrid parents and child (EHPC), for learning the adjacent neighbors of every variable. We proof the validity of the algorithm. Compared with state-of-the-art algorithms, the experimental results show that EHPC can handle large network and has better accuracy with fewer number of condition independence tests and smaller size of conditioning set.
An Empirical Analysis of Evolved Radial Basis Function Networks and Support Vector Machines with Mixture of Kernels
Authors: Dash Ch. Sanjeev Kumar , Sahoo Pulak , Dehuri Satchidananda , Cho Sung-Bae
Published: February 2015

Classification is one of the most fundamental and formidable tasks in many domains including biomedical. In biomedical domain, the distributions of data in most of the datasets into predefined number of classes is significantly different (i.e., the classes are distributed unevenly). Many mathematical, statistical, and machine learning approaches have been developed for classification of biomedical datasets with a varying degree of success. This paper attempts to analyze the empirical performance of two forefront machine learning algorithms particularly designed for classification problem by adding some novelty to address the problem of imbalanced dataset. The evolved radial basis function network with novel kernel and support vector machine with mixture of kernels are suitably designed for the purpose of classification of imbalanced dataset. The experimental outcome shows that both algorithms are promising compared to simple radial basis function neural networks and support vector machine, respectively. However, on an average, support vector machine with mixture kernels is better than evolved radial basis function neural networks.
A unifying description of dark energy
Authors: Gleyzes Jérôme , Langlois David , Vernizzi Filippo
Published: February 2015

We review and extend a novel approach that we recently introduced, to describe general dark energy or scalar-tensor models. Our approach relies on an Arnowitt-Deser-Misner (ADM) formulation based on the hypersurfaces where the underlying scalar field is uniform. The advantage of this approach is that it can describe in the same language and in a minimal way a vast number of existing models, such as quintessence, F(R) theories, scalar tensor theories, their Horndeski extensions and beyond. It also naturally includes Horava–Lifshitz theories. As summarized in this review, our approach provides a unified treatment of the linear cosmological perturbations about a Friedmann-Lemaître-Robertson-Walker (FLRW) universe, obtained by a systematic expansion of our general action up to quadratic order. This shows that the behavior of these linear perturbations is generically characterized by five time-dependent functions. We derive the full equations of motion in the Newtonian gauge. In the Horndeski case, we obtain the equation of state for dark energy perturbations in terms of these functions. Our unifying description thus provides the simplest and most systematic way to confront theoretical models with current and future cosmological observations.
Theoretical investigation of an atmospherically important reaction between methyl methacrylate and Cl atom: A mechanistic and kinetic approach
Authors: Biswas Partha
Published: February 2015

A theoretical investigation of the mechanism, kinetics and probable product analysis of the Cl -initiated oxidation reaction of methyl methacrylate (MMA) is presented in this paper. The major degradation pathway of MMA is the Cl -addition to the terminal carbon of the olefinic bond. Beside this, energetic and mechanism of other possible reaction pathways are discussed in detail. In addition, the mechanism for the secondary reactions in presence of O 2 and NO has also been presented. Cl -addition to the double bond takes place via formation of the pre-reactive complex as these reaction channel passes through negative activation barrier. Energetics and thermochemical analysis have been studied at the MP2=Full/6-311++g(d,p) level of theory. The rate constant of the Cl -addition reaction has been calculated using conventional transition state theory (CTST) at 1 atm pressure and 250–350 K temperature range.
Non-peripherally alkyl substituted ruthenium phthalocyanines as catalysts in the epoxidation of alkenes
Authors: Enow Charles A. , Marais Charlene , Bezuidenhoudt Barend C.B.
Published: February 2015

Non-peripherally alkyl substituted ruthenium phthalocyanines were demonstrated to be highly active epoxidation catalysts. It is compatible with pyridine N-oxides, and especially 2,6-dichloropyridine N-oxide. The catalytic activity towards a variety of alkenes was comparable to that published for other catalytic systems, but superior in the cases of 1,2-dihydronaphthalene and trans-stilbene. Linear substituents on the non-peripheral sites of the phthalocyanine were able to reduce aggregation and increase the solubility of the catalyst without compromising its activity by steric congestion as all substituted catalysts were more reactive than the unsubstituted phthalocyanine, whereas the bulky isopentyl and cyclohexyl substituted catalysts were less active than those with linear substituents. Although the epoxidation mechanism and the exact active intermediate is still ambigious, it likely involves the coordination of the N-oxide to ruthenium and subsequent transfer of the oxygen to the metal to form a high-valent oxo-ruthenium species. It is proposed that the alkene approaches this metal oxo moiety from the top and that oxygen transfer to the alkene is concerted with concomitant stereoretention.
Adsorption and photocatalytic degradation of dyes on polyacrylamide/calcium alginate/TiO2 composite film
Authors: Wei Shuxin , Zhao Kongyin , Zhang Xinxin , Fu Yifan , Li Zhihui , Xu Sai , Wei Junfu
Published: February 2015

A casting solution was prepared by dispersing titanium dioxide ( TiO 2) nanoparticles in the sodium alginate and acrylamide aqueous solution. The casting solution was spread on a glass plate by a glass rod enlaced with brass wires to control the thickness of the sticky solution. Then polyacrylamide/calcium alginate/ TiO 2 (PAM/CA/T) composite film was obtained after UV irradiation and cross-linking by CaCl 2. The PAM/CA/T film was characterized by scanning electron microscope and transmission electron microscope. The PAM/CA/T film had good strength and toughness. And they did not rupture after swelling in 5 wt.% NaCl solution and still had good mechanical properties. The adsorption properties of the PAM/CA/T film were investigated by using different dyes as the adsorbates. The photocatalytic degradation properties of these dyes on the PAM/CA/T films were also researched. The results indicated that there was no difference in the adsorption efficiency of PAM/CA film and PAM/CA/T-30 film. The adsorption rates of all the dyes were fast. The pre-adsorption of dyes had little effect on the catalytic degradation of dyes on PAM/CA/T film. The PAM/CA/T hydrogel film provided a suitable carrier for TiO 2 in the photocatalytic degradation of dyes and the degradation efficiency of PAM/CA/T-30 film for methyl orange reached 80.76%. The PAM/CA/T film had good reusability and could degrade dyes in NaCl solution.
Solid high-proton conductor tungstovanadozincic acid with transition metal as central atom: Synthesis and conductivity
Authors: Huang Tianpei , Wu Xuefei , Wu Qingyin , Cao Fahe , Yan Wenfu
Published: February 2015

A Keggin-type vanadium-substituted tungstovanadozincic heteropoly acid H 7 ZnW 11 VO 40 ⋅ 8 H 2 O , with the transition metal as central atom, was firstly synthesized and characterized. Its proton conductivity was measured by the electrochemical impedance spectrum (EIS), and the result indicates that the H 7 ZnW 11 VO 40 ⋅ 8 H 2 O is a solid high-proton conductor with conductivity of 3.26 × 10-3S ⋅ cm-1 at 58°C, 50% relative humidity. Its activation energy is 29.50 kJ ⋅ mol-1, which suggests that the mechanism of proton conduction is the Vehicle mechanism.
Renal nerve stimulation leads to the activation of the Na+/H+exchanger isoform 3 via angiotensin II type I receptor
Authors: Pontes Roberto B. , Crajoinas Renato O. , Nishi Erika E. , Oliveira-Sales Elizabeth B. , Girardi Adriana C. , Campos Ruy R. , Bergamaschi Cássia T.
Published: February 2015

Renal nerve stimulation at a low frequency (below 2 Hz) causes water and sodium reabsorption via α1-adrenoreceptor tubular activation, a process independent of changes in systemic blood pressure, renal blood flow, or glomerular filtration rate. However, the underlying mechanism of the reabsorption of sodium is not fully understood. Since the sympathetic nervous system and intrarenal ANG II appear to act synergistically to mediate the process of sodium reabsorption, we hypothesized that low-frequency acute electrical stimulation of the renal nerve (ESRN) activates NHE3-mediated sodium reabsorption via ANG II AT1receptor activation in Wistar rats. We found that ESRN significantly increased urinary angiotensinogen excretion and renal cortical ANG II content, but not the circulating angiotensinogen levels, and also decreased urinary flow and pH and sodium excretion via mechanisms independent of alterations in creatinine clearance. Urinary cAMP excretion was reduced, as was renal cortical PKA activity. ESRN significantly increased NHE3 activity and abundance in the apical microvillar domain of the proximal tubule, decreased the ratio of phosphorylated NHE3 at serine 552/total NHE3, but did not alter total cortical NHE3 abundance. All responses mediated by ESRN were completely abolished by a losartan-mediated AT1receptor blockade. Taken together, our results demonstrate that higher NHE3-mediated proximal tubular sodium reabsorption induced by ESRN occurs via intrarenal renin angiotensin system activation and triggering of the AT1receptor/inhibitory G-protein signaling pathway, which leads to inhibition of cAMP formation and reduction of PKA activity.
Anti-inflammatory role of DPP-4 inhibitors in a nondiabetic model of glomerular injury
Authors: Higashijima Yoshiki , Tanaka Tetsuhiro , Yamaguchi Junna , Tanaka Shinji , Nangaku Masaomi
Published: February 2015

Dipeptidyl peptidase (DPP)-4 is an enzyme that cleaves and inactivates incretin hormones capable of stimulating insulin secretion from pancreatic β-cells. DPP-4 inhibitors are now widely used for the treatment of type 2 diabetes. Experimental studies have suggested a renoprotective role of DPP-4 inhibitors in various models of diabetic kidney disease, which may be independent of lowering blood glucose levels. In the present study, we examined the effect of DPP-4 inhibitors in the rat Thy-1 glomerulonephritis model, a nondiabetic glomerular injury model. Rats were injected with OX-7 (1.2 mg/kg iv) and treated with the DPP-4 inhibitor alogliptin (20 mg·kg−1·day−1) or vehicle for 7 days orally by gavage. Alogliptin significantly reduced the number of CD68-positive inflammatory macrophages in the kidney, which was associated with a nonsignificant tendency to ameliorate glomerular injury and reduce proteinuria. Another DPP-4 inhibitor, anagliptin (300 mg·kg−1·day−1 mixed with food) and a glucagon-like peptide-1 receptor agonist, exendin-4 (10 mg/kg sc), similarly reduced CD68-positive macrophage infiltration to the kidney. Furthermore, ex vivo transmigration assays using peritoneal macrophages revealed that exendin-4, but not alogliptin, dose dependently reduced monocyte chemotactic protein-1-stimulated macrophage infiltration. These data suggest that DPP-4 inhibitors reduced macrophage infiltration directly via glucagon-like peptide-1-dependent signaling in the rat Thy-1 nephritis model and indicate that the control of inflammation by DPP-4 inhibitors is useful for the treatment of nondiabetic kidney disease models.
Fetal programming of chronic kidney disease: the role of maternal smoking, mitochondrial dysfunction, and epigenetic modfification
Authors: Stangenberg Stephanie , Chen Hui , Wong Muh Geot , Pollock Carol A. , Saad Sonia
Published: February 2015

The role of an adverse in utero environment in the programming of chronic kidney disease in the adult offspring is increasingly recognized. The cellular and molecular mechanisms linking the in utero environment and future disease susceptibility remain unknown. Maternal smoking is a common modifiable adverse in utero exposure, potentially associated with both mitochondrial dysfunction and epigenetic modification in the offspring. While studies are emerging that point toward a key role of mitochondrial dysfunction in acute and chronic kidney disease, it may have its origin in early development, becoming clinically apparent when secondary insults occur. Aberrant epigenetic programming may add an additional layer of complexity to orchestrate fibrogenesis in the kidney and susceptibility to chronic kidney disease in later life. In this review, we explore the evidence for mitochondrial dysfunction and epigenetic modification through aberrant DNA methylation as key mechanistic aspects of fetal programming of chronic kidney disease and discuss their potential use in diagnostics and targets for therapy.
Concurrent deficits of soleus and gastrocnemius muscle fascicles and Achilles tendon post stroke
Authors: Zhao Heng , Ren Yupeng , Roth Elliot J. , Harvey Richard L. , Zhang Li-Qun
Published: February 2015

Calf muscles and Achilles tendon play important roles in functional activities. However, it is not clear how biomechanical properties of the uniarticular soleus (SOL) and biarticular gastrocnemius muscle and Achilles tendon, including the fascicle length, pennation angle, and stiffness, change concurrently post stroke. Biomechanical properties of the medial gastrocnemius (GM) and soleus muscles were evaluated bilaterally in 10 hemiparetic stroke survivors using combined ultrasonography-biomechanical measurements. Biomechanical properties of the Achilles tendon including the length, cross-sectional area (CSA), stiffness, and Young's modulus were evaluated, together with calf muscle biomechanical properties. Gastrocnemius and SOL contributions were separated using flexed and extended knee positions. The impaired side showed decreased fascicle length (GM: 6%, P = 0.002 and SOL: 9%, P = 0.03, at full knee extension and 0° ankle dorsiflexion) and increased fascicular stiffness (GM: 64%, P = 0.005 and SOL: 19%, P = 0.012, at a common 50 N force level). In contrast, Achilles tendon on the impaired side showed changes in the opposite direction as the muscle fascicles with increased tendon length (5%, P < 0.001), decreased tendon CSA (5%, P = 0.04), decreased tendon stiffness (42%, P < 0.001) and Young's modulus (30%, P < 0.001) compared with the unimpaired side. The fascicle and tendon stiffness changes were correlated negatively to the corresponding fascicle and tendon length changes, and decrease in Achilles tendon stiffness was correlated to the increases of SOL and GM fascicular stiffness ( P < 0.05). Characterizations of calf muscle fascicles and Achilles tendon biomechanical properties help us better understand concurrent changes of fascicles and tendon as part of the calf muscle-tendon unit and facilitate development of more effective treatments.