bluuebunny/crossref_metadata_2025 huggingface dataset:
Accuracy Issues in the Prediction of Supersonic Inlet Flows
Authors: Paynter G. C. , Tjonneland E.
Published: March 2015

Numerical and modeling accuracy issues are examined for two types of inlet flow analyses through a discussion of how numerical and modeling errors can influence the predicted inlet performance. For supersonic inlets, two types of procedures are in use at Boeing. The first is a zonal method that has been in use and under development for two decades. The second is based on solution of the Reynolds averaged NS (Navier-Stokes) equations; NS methods have been applied to the prediction of supersonic inlet flows for only about the last five years. The primary advantage of the zonal procedure is that accurate performance predictions are obtained on a computer workstation for only modest computational resources. The primary advantages of the NS procedures are the almost unlimited geometries and flows that can be considered. The accuracy (or lack thereof) achievable by either type of procedure is determined by the errors introduced by both the numerical procedures and by the modeling. At present, NS analysis is at about the same level of accuracy as the more mature zonal procedure. NS analysis offers, however, a wider range of flows and geometries that can be analyzed and less reliance on a sophisticated understanding of inlet flow phenomena necessary for modeling. Continuing advances in computing technology foretell a bright future for the use of CFD (Computational Fluid Dynamics) for supersonic inlet design when accuracy issues that constrain the usefulness are addressed.
Optimization Aspects of an Ejector Type Hypersonic Thrust Nozzle
Authors: Trittler G. , Eckert E. , Göing M.
Published: March 2015

Hypersonic aircraft projects are highly dependant on efficient propulsion systems. High performance and integration within the airframe play a vital role in the overall concept. Particular attention must be paid to the exhaust system that is submitted to a wide range of operational requirements.

An optimization of the nozzle geometry for high flight Mach numbers will lead to a low performance at the transonic flight regime. The additional use of secondary ejector air flow at transonic speeds is one option to improve the thrust behaviour of the nozzle.

In the presented paper performance data of single expansion ramp ejector type nozzles are predicted using a calculation model based on a method-of-characteristics algorithm. For optimization purposes the effects of various design parameters on axial thrust coefficient and thrust vector angle are discussed. The geometric parameters investigated are the length of the lower nozzle wall and its deflection angle as well as the ejector slot location and its cross-section.
Fuel Cell Powered Electric Propulsion for HALE Aircraft
Authors: Bentz John C.
Published: March 2015

Electrical energy sources offer some interesting possibilies for aircraft propulsion. Of particular interest are electric propulsion systems developed for aircraft that are designed for high altitude, long endurance (HALE) missions. This class of aircraft would greatly benefit from an aircraft propulsion system which minimizes thermal energy rejection and environmental pollutants. Electric propulsion systems may prove viable for the HALE mission, if reliable energy sources can be developed that are both fuel and weight efficient. Fuel cells are a possible energy source. This paper discusses the thermodynamic cyclic analysis of a fuel cell powered electric propulsion system. In particular, phosphoric acid and polymer electrolyte fuel cells are evaluated as possible energy sources.
Expert Systems for the Simulation of Gas Turbine Engines
Authors: Torella G.
Published: March 2015

The paper deals with the possibility to develop effective Expert Systems for the simulation, the monitoring and the diagnostics of engines.

The work concerns with the development of suitable Knowledge Bases and Expert Systems for different activities.

The approach to the problem deals with Expert Systems for engine simulation. These Systems give the operating limits of the engine and the required control laws for reaching assigned values of performance.

Other Expert Systems have been developed for fault simulation. The matrices of influence have proved to be suitable for constructing effective Knowledge Bases.

Finally Expert Systems for engine diagnostics have been set-up.

The paper shows in full detail the methods, the techniques and several applications of the developed codes.
A Novel Approach to High Resolution Compressible Cascade Flow Analysis Using the Navier-Stokes Equations
Authors: Ng E. Y.-K. , Dawes W. N.
Published: March 2015

This paper deals with the development of a technique aimed at improving the accuracy of 2-D flow solutions of turbomachinery problems. The basic concept is to take a quasi-3D Navier-Stokes or Euler solver on a coarse mesh (the “outer code”) and couple it to a 2-D space marching parabolised Navier-Stokes solver on a finer sub-mesh (the “inner code”). The “inner-code” includes the FLARE approximation to permit reverse flow. The inner and outer codes are coupled by adopting an approach analogous to classical multigrid methods. The combination forms a cheap and fast solver to provide fine resolution solutions using only mini-computer resources. Predictions of the flow through a compressor and a turbine cascade are described and show good agreement with the experimental results.
Optimal Circumferential Placement of Cylindrical Thermocouple Probes for Reduction of Excitation Forces
Authors: Cobb Eben C. , Cheu Tsu-Chien , Hoffman Jay
Published: March 2015

This paper presents a design methodology to determine the optimal circumferential placement of cylindrical probes upstream of a turbine stage for reduced excitation forces. The potential flow forcing function generated by the probes is characterized by means of a Fourier analysis. A finite difference formulation is used to evaluate the sensitivity of the forcing function to the probe positions. An optimization scheme, based on the linear programming method, uses the sensitivity analysis results to reposition the probes such that the Fourier amplitudes of critical excitation orders are reduced. The results for an example design situation are presented.
State of the Art of Ultrasonic Liquid Flow Measurement and it’s Impact on Automated Leak Detection in Pipelines
Authors: Smulski Michael L.
Published: March 2015

The state of the art of ultrasonic liquid flow measurement has improved greatly in the past decade to where this technology exhibits accuracy equivalent to turbine meter systems, while retaining several advantages over turbine meters.

Testing of a four path non-intrusive meter used for leak detection on the Trans–Alaska Pipeline is discussed. Performance is detailed, and future applications for ultrasonic flow measurement technology are reviewed.
Turbocompressor Antisurge Control, New Solution for an Old Problem
Authors: Gaston John R.
Published: March 2015

The performance of many antisurge control systems is degraded because they do not adequately compensate for variable gas properties (primarily molecular weight). The consequences can range from inefficient operation to serious compressor damage due to surges.

To eliminate deficiencies previously experienced, a new, relatively simple (requires measuring only three process variables) system was developed for a machine which normally compresses a 24.2 molecular weight gas, but is also required to operate on other gas mixtures of approximately 40% lower molecular weight. The new method is explained and the results compared with two other widely used concepts.
TRAF6 phosphorylation inhibits inflammation
Authors: Foley John F.
Published: March 2015

Phosphorylation of the E3 ubiquitin ligase TRAF6 by the kinase MST4 inhibits inflammatory responses in macrophages.
Third-Generation-Cephalosporin-Resistant Klebsiella pneumoniae Isolates from Humans and Companion Animals in Switzerland: Spread of a DHA-Producing Sequence Type 11 Clone in a Veterinary Setting
Authors: Wohlwend Nadia , Endimiani Andrea , Francey Thierry , Perreten Vincent
Published: March 2015

Characterization of third-generation-cephalosporin-resistant
Klebsiella pneumoniae
isolates originating mainly from one human hospital (
n
= 22) and one companion animal hospital (
n
= 25) in Bern (Switzerland) revealed the absence of epidemiological links between human and animal isolates. Human infections were not associated with the spread of any specific clone, while the majority of animal infections were due to
K. pneumoniae
sequence type 11 isolates producing plasmidic DHA AmpC. This clonal dissemination within the veterinary hospital emphasizes the need for effective infection control practices.
Profiling of β-Lactam Selectivity for Penicillin-Binding Proteins in Escherichia coli Strain DC2
Authors: Kocaoglu Ozden , Carlson Erin E.
Published: March 2015

Penicillin-binding proteins (PBPs) are integral players in bacterial cell division, and their catalytic activities can be monitored with β-lactam-containing chemical probes. Compounds that target a single PBP could provide important information about the specific role(s) of each enzyme, making identification of such molecules important. We evaluated 22 commercially available β-lactams for inhibition of the PBPs in live
Escherichia coli
strain DC2. Whole cells were titrated with β-lactam antibiotics and subsequently incubated with a fluorescent penicillin derivative, Bocillin-FL (Boc-FL), to label uninhibited PBPs. Protein visualization was accomplished by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) separation and fluorescent scanning. The examined β-lactams exhibited diverse PBP selectivities, with amdinocillin (mecillinam) showing selectivity for PBP2, aztreonam, piperacillin, cefuroxime, cefotaxime, and ceftriaxone for PBP3, and amoxicillin and cephalexin for PBP4. The remaining β-lactams did not block any PBPs in the DC2 strain of
E. coli
or inhibited more than one PBP at all examined concentrations in this Gram-negative organism.
Identification and Characterization of Multidrug-Resistant Salmonella enterica Serotype Albert Isolates in the United States
Authors: Folster Jason P. , Campbell Davina , Grass Julian , Brown Allison C. , Bicknese Amelia , Tolar Beth , Joseph Lavin A. , Plumblee Jodie R. , Walker Carrie , Fedorka-Cray Paula J. , Whichard Jean M.
Published: March 2015

Salmonella enterica
is one of the most common causes of bacterial foodborne illness in the United States. Although most
Salmonella
infections are self-limiting, antimicrobial treatment of invasive salmonellosis is critical. The primary antimicrobial treatment options include fluoroquinolones or extended-spectrum cephalosporins, and resistance to these antimicrobial drugs may complicate treatment. At present,
S. enterica
is composed of more than 2,600 unique serotypes, which vary greatly in geographic prevalence, ecological niche, and the ability to cause human disease, and it is important to understand and mitigate the source of human infection, particularly when antimicrobial resistance is found. In this study, we identified and characterized 19
S. enterica
serotype Albert isolates collected from food animals, retail meat, and humans in the United States during 2005 to 2013. All five isolates from nonhuman sources were obtained from turkeys or ground turkey, and epidemiologic data suggest poultry consumption or live-poultry exposure as the probable source of infection.
S. enterica
serotype Albert also appears to be geographically localized to the midwestern United States. All 19 isolates displayed multidrug resistance, including decreased susceptibility to fluoroquinolones and resistance to extended-spectrum cephalosporins. Turkeys are a likely source of multidrug-resistant
S. enterica
serotype Albert, and circulation of resistance plasmids, as opposed to the expansion of a single resistant strain, is playing a role. More work is needed to understand why these resistance plasmids spread and how their presence and the serotype they reside in contribute to human disease.
Sequence Elements Upstream of the Core Promoter Are Necessary for Full Transcription of the Capsule Gene Operon in Streptococcus pneumoniae Strain D39
Authors: Wen Zhensong , Sertil Odeniel , Cheng Yongxin , Zhang Shanshan , Liu Xue , Wang Wen-Ching , Zhang Jing-Ren
Published: March 2015

Streptococcus pneumoniae
is a major bacterial pathogen in humans. Its polysaccharide capsule is a key virulence factor that promotes bacterial evasion of human phagocytic killing. While
S. pneumoniae
produces at least 94 antigenically different types of capsule, the genes for biosynthesis of almost all capsular types are arranged in the same locus. The transcription of the capsular polysaccharide (
cps
) locus is not well understood. This study determined the transcriptional features of the
cps
locus in the type 2 virulent strain D39. The initial analysis revealed that the
cps
genes are cotranscribed from a major transcription start site at the −25 nucleotide (G) upstream of
cps2A
, the first gene in the locus. Using unmarked chromosomal truncations and a luciferase-based transcriptional reporter, we showed that the full transcription of the
cps
genes not only depends on the core promoter immediately upstream of
cps2A
, but also requires additional elements upstream of the core promoter, particularly a 59-bp sequence immediately upstream of the core promoter. Unmarked deletions of these promoter elements in the D39 genome also led to significant reduction in CPS production and virulence in mice. Lastly, common
cps
gene (
cps2ABCD
) mutants did not show significant abnormality in
cps
transcription, although they produced significantly less CPS, indicating that the CpsABCD proteins are involved in the encapsulation of
S. pneumoniae
in a posttranscriptional manner. This study has yielded important information on the transcriptional characteristics of the
cps
locus in
S. pneumoniae
.
ThefsrQuorum-Sensing System and Cognate Gelatinase Orchestrate the Expression and Processing of Proprotein EF_1097 into the Mature Antimicrobial Peptide Enterocin O16
Authors: Dundar Halil , Brede Dag A. , La Rosa Sabina Leanti , El-Gendy Ahmed Osama , Diep Dzung B. , Nes Ingolf F.
Published: March 2015

A novel antimicrobial peptide designated enterocin O16 was purified fromEnterococcus faecalis. Mass spectrometry showed a monoisotopic mass of 7,231 Da, and N-terminal Edman degradation identified a 29-amino-acid sequence corresponding to residues 90 to 119 of the EF_1097 protein. Bioinformatic analysis showed that enterocin O16 is composed of the 68 most C-terminal residues of the EF_1097 protein. Introduction of an in-frame isogenic deletion in theef1097gene abolished the production of enterocin O16. Enterocin O16 has a narrow inhibitory spectrum, as it inhibits mostly lactobacilli. Apparently,E. faecalisis intrinsically resistant to the antimicrobial peptide, as no immunity connected to the production of enterocin O16 could be identified.ef1097has previously been identified as one of three loci regulated by thefsrquorum-sensing system. The introduction of a nonsense mutation intofsrBconsistently impaired enterocin O16 production, but externally added gelatinase biosynthesis-activating pheromone restored the antimicrobial activity. Functional genetic analysis showed that the EF_1097 proprotein is processed extracellularly into enterocin O16 by the metalloprotease GelE. Thus, it is evident that thefsrquorum-sensing system constitutes the regulatory unit that controls the expression of the EF_1097 precursor protein and the protease GelE and that the latter is required for the formation of enterocin O16. On the basis of these results, this study identified antibacterial antagonism as a novel aspect related to the function offsrand provides a rationale for whyef1097is part of thefsrregulon.

IMPORTANCEThefsrquorum-sensing system modulates important physiological functions inE. faecalisvia the activity of GelE. The present study presents a new facet offsrsignaling. The system controls the expression of three primary target operons (fsrABCD,gelE-sprE, andef1097-ef1097b). We demonstrate that the concerted expression of these operons constitutes the elements necessary for the production of a bacteriocin-type peptide and that antimicrobial antagonism is an intrinsic function offsr. The bacteriocin enterocin O16 consists of the 68 most C-terminal residues of the EF_1097 secreted proprotein. The GelE protease processes the EF_1097 proprotein into enterocin O16. In this manner,fsrsignaling enablesE. faecalispopulations to express antimicrobial activity in a cell density-dependent manner.
Evolution of Molybdenum Nitrogenase during the Transition from Anaerobic to Aerobic Metabolism
Authors: Boyd Eric S. , Costas Amaya M. Garcia , Hamilton Trinity L. , Mus Florence , Peters John W.
Published: March 2015

Molybdenum nitrogenase (Nif), which catalyzes the reduction of dinitrogen to ammonium, has modulated the availability of fixed nitrogen in the biosphere since early in Earth's history. Phylogenetic evidence indicates that oxygen (O2)-sensitive Nif emerged in an anaerobic archaeon and later diversified into an aerobic bacterium. Aerobic bacteria that fix N2have adapted a number of strategies to protect Nif from inactivation by O2, including spatial and temporal segregation of Nif from O2and respiratory consumption of O2. Here we report the complement of Nif-encoding genes in 189 diazotrophic genomes. We show that the evolution of Nif during the transition from anaerobic to aerobic metabolism was accompanied by both gene recruitment and loss, resulting in a substantial increase in the number ofnifgenes. While the observed increase in the number ofnifgenes and their phylogenetic distribution are strongly correlated with adaptation to utilize O2in metabolism, the increase is not correlated with any of the known O2protection mechanisms. Rather, gene recruitment appears to have been in response to selective pressure to optimize Nif synthesis to meet fixed N demands associated with aerobic productivity and to more efficiently regulate Nif under oxic conditions that favor protein turnover. Consistent with this hypothesis, the transition of Nif from anoxic to oxic environments is associated with a shift from posttranslational regulation in anaerobes to transcriptional regulation in obligate aerobes and facultative anaerobes. Given that fixed nitrogen typically limits ecosystem productivity, our observations further underscore the dynamic interplay between the evolution of Earth's oxygen, nitrogen, and carbon biogeochemical cycles.

IMPORTANCEMolybdenum nitrogenase (Nif), which catalyzes the reduction of dinitrogen to ammonium, has modulated the availability of fixed nitrogen in the biosphere since early in Earth's history. Nif emerged in an anaerobe and later diversified into aerobes. Here we show that the transition of Nif from anaerobic to aerobic metabolism was accompanied by both gene recruitment and gene loss, resulting in a substantial increase in the number ofnifgenes. While the observed increase in the number ofnifgenes is strongly correlated with adaptation to utilize O2in metabolism, the increase is not correlated with any of the known O2protective mechanisms. Rather, gene recruitment was likely a response to more efficiently regulate Nif under oxic conditions that favor protein turnover.
Acupuncture for Joint Symptoms Related to Aromatase Inhibitor Therapy in Postmenopausal Women with Early-Stage Breast Cancer: A Narrative Review
Authors: Halsey Elizabeth J , Xing Mei , Stockley Rachel C
Published: March 2015

Background

Aromatase inhibitor-induced musculoskeletal syndrome (AIMSS) leads to discontinuation of aromatase inhibitor therapy in a significant proportion of patients with breast cancer. Acupuncture is popular among cancer patients and has previously been shown to improve symptoms in a range of musculoskeletal complaints.

Aim

To determine the effectiveness and safety of acupuncture for the management of AIMSS in postmenopausal women with early-stage breast cancer.

Methods

A literature search was carried out for randomised controlled trials (RCTs) on acupuncture for AIMSS in postmenopausal women with early-stage breast cancer. Characteristics of trials and outcomes were extracted from the retrieved articles, which were also assessed for risk of bias and quality of reporting.

Results

Four RCTs were retrieved of sample size 32–67 (totalling 190 participants). Compliance with treatment was high and rates of adverse events were low. Of the three two-arm RCTs, two found no difference between acupuncture and sham acupuncture and one found that acupuncture was statistically superior to sham acupuncture. The fourth RCT, which incorporated three arms, found acupuncture and sham acupuncture to be statistically superior to usual care but there was no difference between true and sham acupuncture. Three trials that used non-penetrating sham as the control found no effect of acupuncture over sham, but the one trial that used superficial needle insertion found acupuncture to be superior.

Conclusions

Acupuncture is safe and results in improvement in AIMSS symptoms, but similar benefits are also elicited by non-penetrating sham acupuncture. Future research should seek to establish the durability of improvements.
Aetiology of arthritis in hospitalised children: an observational study
Authors: Aupiais Camille , Ilharreborde Brice , Doit Catherine , Blachier Audrey , Desmarest Marie , Job-Deslandre Chantal , Mazda Keyvan , Faye Albert , Bonacorsi Stéphane , Alberti Corinne , Lorrot Mathie
Published: March 2015

Background and objective

Arthritis in children has many causes and includes septic and viral arthritis, reactive arthritis and juvenile idiopathic arthritis (JIA). We aimed to describe the different types of arthritis among children hospitalised for a first episode of arthritis.

Design

Retrospective, descriptive case series study.

Setting

A French tertiary care centre.

Patients

Children under 16 years of age hospitalised for an arthritis episode between 1 January 2008 and 31 December 2009.

Main outcome measures

Demographic and clinical features were compared with χ2or Fisher's exact tests and non-parametric tests.

Results

173 children were hospitalised for a first episode of arthritis during the study period, with a male/female ratio of 1.14. The most frequent cause of hospitalisation was septic arthritis (43.4% of cases, 69.3% of which were due toKingella kingaeand 10.7% toStaphylococcus aureus). JIA was responsible for 8.1% of cases and arthritis without any definitive diagnosis for 40.4%. Median age at diagnosis was 2.7 years (IQR 0.3–14.6) and was lower in the septic arthritis group (1.5 years; 1.1–3.4) than in the JIA group (4.7 years; 2.5–10.9) (p<0.01). Septic arthritis involved a single joint in 97.3% of cases, while JIA involved four joints in 14.3% of cases and two to four joints in 28.6% of cases (p<0.01).

Conclusions

Septic arthritis was the most frequent cause of arthritis in hospitalised children. Despite the increasing application of microbiological molecular methods to synovial fluid analysis, further measures are required to improve the diagnosis of arthritis of unknown cause.
Embolisation of pheochromocytoma to stabilise and wean a patient in cardiogenic shock from emergency extracorporeal life support
Authors: Vagner Helle , Hey Thomas Morris , Elle Bo , Jensen Marianne Kjær
Published: March 2015

Pheochromocytoma is a catecholamine-secreting tumour associated with varying symptoms ranging from episodic headache, sweating, paroxysmal hypertension and tachycardia to intractable cardiogenic shock. Cardiogenic shock is rare but well-described and the timing of correct management is crucial since mortality is high. Fifty per cent of pheochromocytomas are diagnosed on autopsy. We report on a case of embolisation of the adrenal artery during ongoing extracorporeal life support (ECLS) in order to stabilise and wean the patient from ECLS as a bridge to final surgery.
Outcome of patients admitted with acute coronary syndrome on palliative treatment: insights from the nationwide AMIS Plus Registry 1997–2014
Authors: Erne Paul , Radovanovic Dragana , Seifert Burkhardt , Bertel Osmund , Urban Philip
Published: March 2015

Objective

Compliance with guidelines is increasingly used to benchmark the quality of hospital care, however, very little is known on patients admitted with acute coronary syndromes (ACS) and treated palliatively. This study aimed to evaluate the baseline characteristics and outcomes of these patients.

Design

Prospective cohort study.

Setting

Eighty-two Swiss hospitals enrolled patients from 1997 to 2014.

Participants

All patients with ACS enrolled in the AMIS Plus registry (n=45 091) were analysed according to three treatment groups: palliative treatment, defined as use of aspirin and analgesics only and no reperfusion; conservative treatment, defined as any treatment including antithrombotics or anticoagulants, heparins, P2Y12inhibitors, GPIIb/IIIa but no pharmacological or mechanical reperfusion; and reperfusion treatment (thrombolysis and/or percutaneous coronary intervention during initial hospitalisation). The primary outcome measure was in-hospital mortality and the secondary measure was 1-year mortality.

Results

Of the patients, 1485 (3.3%) were palliatively treated, 11 119 (24.7%) were conservatively treated and 32 487 (72.0%) underwent reperfusion therapy. In 1997, 6% of all patients were treated palliatively and this continuously decreased to 2% in 2013. Baseline characteristics of palliative patients differed in comparison with conservatively treated and reperfusion patients in age, gender and comorbidities (all p<0.001). These patients had more in-hospital complications such as postadmission onset of cardiogenic shock (15.6% vs 5.2%; p<0.001), stroke (1.8% vs 0.8%; p=0.001) and a higher in-hospital mortality (25.8% vs 5.6%; p<0.001).The subgroup of patients followed 1 year after discharge (n=8316) had a higher rate of reinfarction (9.2% vs 3.4%; p=0.003) and mortality (14.0% vs 3.5%; p<0.001).

Conclusions

Patients with ACS treated palliatively were older, sicker, with more heart failure at admission and very high in-hospital mortality. While refraining from more active therapy may often constitute the most humane and appropriate approach, we think it is important to also evaluate these patients and include them in registries and outcome evaluations.

Clinical trial number

ClinicalTrials.gov Identifier: NCT01 305 785.
Effect of nitrogen atom substitution in cyclic guests on properties of structure H clathrate hydrates
Authors: Imasato Kazuki , Murayama Kotaro , Takeya Satoshi , Alavi Saman , Ohmura Ryo
Published: March 2015

The effect of substituting nitrogen heteroatoms in the cyclohexane ring of methylcyclohexane on the structure and guest dynamics of structure H (sH) clathrate hydrates with methane help gases are studied through experimental synthesis, powder X-ray diffraction (PXRD) measurements, and classical molecular dynamics simulation of methylcyclohexane and 1-methylpiperidine. The PXRD measurements were performed for temperatures in the range of 138 to 183 K, and the a axis and c axis lattice constants were determined in this temperature range. The PXRD results show the different thermal expansivity of lattice constants in both sH hydrate cages. Simulations on methylcyclohexane and 1-methylpiperidine are performed, and the effects of methane cage occupancy on the lattice constants were studied by simulations with 100% and 80% of the small and medium cages occupied by methane. The sH phases do not expand isotropically, and the a and c lattice constants can vary over a range of 0.015 Å and 0.06 Å, respectively, depending on the large cage guest and methane occupancy. Hydrogen bonding between the 1-methylpiperidine nitrogen atom and cage water in the sH hydrate are not observed in the simulations, and differences in behavior of the two sH hydrates are likely related to the differences in geometry of the large guests and occupancies of methane in the small and medium sH cages.
Landau free energy and analytic tricritical point in holographic superfluid
Authors: Huang Wung-Hong
Published: March 2015

We investigate the analytical method in studying the holographic superfluid model which is described by Maxwell field minimally coupling to a charged scalar field in a fixed AdS black hole background. We propose a method that enables us to find exact value of coefficient in the solution and thus obtain higher-order expansion of the associated Landau free energy of the holographic superfluid with flow. We determine the critical value of superfluid velocity at the tricritical point of holographic superfluid and compare it with the numerical value.
Finger Vein Verification with Vein Textons
Authors: Dong Lumei , Yang Gongping , Yin Yilong , Xi Xiaoming , Yang Lu , Liu Fei
Published: March 2015

Finger vein pattern has become one of the most promising biometric identifiers. In this paper, a robust method based on Bag-of-Words (BoW) is developed for finger vein verification. Firstly, some robust and discriminative visual words are learned from local base features such as Local Binary Pattern (LBP), Mean Curvature and Webber Local Descriptor (WLD). We name these visual words as Finger Vein Textons (FVTs). Secondly, each image is mapped into a FVTs matrix. Finally, spatial pyramid matching (SPM) method is applied to maintain spatial layout information by representing each image as pyramid histogram which is performed for matching by histogram intersection function. Experimental results show that the proposed method achieves satisfactory performance both on our database and the open PolyU database. In addition, our method also has strong robustness and high accuracy on the self-built rotation and illumination databases.
DSP-Based Control of Tri-State Boost PFC Converter with High Input Power Factor for Wide Range of Load Variations
Authors: Cao Taiqiang , You Fang , Zhang Fei , Yang Ping , Luo Qian , Wang Jun
Published: March 2015

Tri-state boost power factor correction (PFC) converter operating in pseudo-continuous-conduction mode (PCCM) is analyzed in this paper. The connection of power switch in parallel with inductor makes the boost converter operate in PCCM, which provides an additional degree of control freedom by inductor current freewheeling operation mode. Compared with boost PFC converter operating in continuous conduction mode (CCM) and discontinuous conduction mode (DCM), tri-state boost PFC converter extends the load range and is therefore more suitable for wide range of load variation. However, for universal input applications, the input power factor (PF) of the tri-state boost PFC converter is relatively low when the sinusoidal reference current control strategy is used. To improve the PF over the whole input voltage range, the input current and PF expressions of the tri-state boost PFC converter is derived and the non-sinusoidal reference current control strategy is proposed. A 400 W prototype of the tri-state boost PFC converter is built by using digital signal processing (DSP) as the controller. The experimental results verify the analysis results.
Neutron density distributions analyzed in terms of relativistic impulse approximation for nickel isotopes
Authors: Kaki Kaori
Published: March 2015

Observables of proton elastic scattering from nickel isotopes (48–82 Ni ) are calculated based on relativistic impulse approximation (RIA), and nuclear density distributions are provided by relativistic mean-field (RMF) calculations. Contributions of a medium effect and multiple scattering to observables are evaluated and shown to be small at incident proton energies from 200 MeV through 500 MeV so that it is confirmed to perform a model analysis based on the fundamental RIA calculation. For 58,60,62,64 Ni isotopes, are considered proton distributions which are obtained by means of unfolding the charge form factor of proton from charge densities determined by the experiments of electron scattering. Through comparisons between results for the different proton densities, contributions of proton form factor to proton distributions and to elastic scattering observables at 300 MeV are discussed. It is shown that the neutron distribution is determined from the restricted observables, reaction cross-section and the first dip of differential cross-section, based on a model analysis of Woods–Saxon distribution in the case of 64 Ni target at 300 MeV. Contributions of tensor density and empirical proton density are shown to obtaining the neutron distribution with the model analysis. Compared with the similar studies for 40,60 Ca and 208 Pb , problems of the model analysis, which arise out of errors in observables, are discussed.
Amino-Functionalized Multi-Walled Carbon Nanotubes as Novel Adsorbents for Selective Adsorption of Anionic Dyes in Aqueous Solution
Authors: Huang Hui , Yu Jingang , Liu Wei , Jiang Xinyu
Published: March 2015

In this study, amino-functionalized multi-walled carbon nanotubes ( MWCNTs - NH2) were successfully synthesized via an improved method and used for removal of organic dyes in aqueous solution. The synthesized MWCNTs - NH2were characterized by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), scanning electron microscope (SEM), etc. The adsorption capacity and selectivity of MWCNTs - NH2for organic dyes was evaluated using rhodamine B ( RhB ), malachite green (MG), methyl orange (MO) and congo red (CR) as models. The selective adsorption toward anionic dyes was found for the MWCNTs - NH2, and MO was selected as a typical anionic dye to deeply investigate the adsorption kinetics, equilibrium isotherms and thermodynamic parameters of the adsorption process. The adsorption kinetics and equilibrium isotherms data fitted well with the pseudo-second-order kinetic equation and Langmuir isotherm model. The thermodynamics study revealed that the adsorption of MO onto MWCNTs - NH2was spontaneous, exothermic and physisorptive in nature. The results indicated that MWCNTs - NH2are promising nanomaterials for removal of anionic dyes from industrial wastewater.
Global properties of nonlinear humoral immunity viral infection models
Authors: Elaiw A. M. , AlShamrani N. H.
Published: March 2015

In this paper, we consider two nonlinear models for viral infection with humoral immunity. The first model contains four compartments; uninfected target cells, actively infected cells, free virus particles and B cells. The second model is a modification of the first one by including the latently infected cells. The incidence rate, removal rate of infected cells, production rate of viruses and the latent-to-active conversion rate are given by more general nonlinear functions. We have established a set of conditions on these general functions and determined two threshold parameters for each model which are sufficient to determine the global dynamics of the models. The global asymptotic stability of all equilibria of the models has been proven by using Lyapunov theory and applying LaSalle's invariance principle. We have performed some numerical simulations for the models with specific forms of the general functions. We have shown that, the numerical results are consistent with the theoretical results.
Study of laser beam scattering by inhomogeneous ensemble of red blood cells in a shear flow
Authors: Nikitin S. Yu. , Lugovtsov A. E. , Ustinov V. D. , Lin M. D. , Priezzhev A. V.
Published: March 2015

Laser ektacytometry is a technique widely used for measuring the deformability of red blood cells (erythrocytes) in blood samples in vitro. In ektacytometer, a flow of highly diluted suspension of erythrocytes in variable shear stress conditions is illuminated with a laser beam to obtain a diffraction pattern. The diffraction pattern provides information about the shapes (shear-induced elongations) of the cells under investigation. This paper is dedicated to developing the technique of laser ektacytometry so that it would enable one to measure the distribution of the erythrocytes in deformability. We discuss the problem of calibration of laser ektacytometer and test a novel data processing algorithm allowing to determine the parameters of the distribution of erythrocytes deformability. Experimentally, we examined 12 specimens of blood of rats under the action of 4 shear stresses. Analysis of the data shows that in conditions of a limited range of digitizing the diffraction patterns, the measurement errors for the mean deformability, deformability scatter and the skewness of erythrocytes distribution in deformability by our method are respectively 15%, 20% and 20%.
Chapter 5 Controls on sedimentation in Indian Palaeoproterozoic basins: clues from the Gwalior and Bijawar basins, central India
Authors: Chakraborty Partha Pratim , Pant Naresh Chandra , Paul Pritam P.
Published: March 2015

Overlying Archaean Bundelkhand Granite Gneiss Complex, the Gwalior and Bijawar Groups of rocks represent two Palaeoproterozoic basin successions which, despite their common sediment provenance and analogous rift-related tectonic setup, record more dissimilarity in their sedimentation pattern than similarity. Whereas early sedimentation in the Gwalior Basin is clastic, the early Bijawar sedimentation is dominantly chemogenic (limestone and chert) except for an early, restricted volcano-clastic record. Although both of the basins record syn-depositional volcanic/volcaniclastic event(s) in the form of occurrence of basaltic and basaltic–andesite sills encased within their respective basin fills, the occurrence of iron formation in the later part of Gwalior sedimentation history and its absence in the Bijawar succession is related to variable oxidation conditions in the water columns of the two basins. Rising sea-level and upwelling on the continental margins of these two rift-related basins possibly generated different water chemistries; these allowed the deposition of iron formation in the Gwalior Basin and phosphorite in the Bijawar Basin. Effects of post-depositional digenetic re-crystallization are noticed within both iron formation and phosphorite deposits present in the basin successions.
Teaching Computer Vision
Authors: Hassner Tal , Bayaz Itzik
Published: March 2015

This article concerns the design of effective computer vision programming exercises and presents a novel means of designing these assignments. We describe three recent case studies designed to evaluate the effectiveness of assigning graduate-level computer vision students with publicly available research benchmarks as competitive assignments. This was done rather than assigning more traditional exercises that require students to implement specific algorithms or applications. We allowed our students the freedom of designing or choosing their own methods, with the goal of obtaining the best performance on the benchmark chosen for each assignment. Students, therefore, competed against each other, as well as published state of the art. We detail the design, application, and results of these benchmark exercises. We show that not only are these benchmarks easily adapted for the classroom, but also that in some cases, student assignments matched published state-of-the-art performance. This observation provides strong evidence to support the effectiveness of the proposed exercise design. We conclude by discussing the benefits and drawbacks of these exercises compared to those traditionally employed in computer vision classrooms.
Z-MAP
Authors: Wei Qingsong , Chen Cheng , Xue Mingdi , Yang Jun
Published: March 2015

Existing space management and address mapping schemes for flash-based Solid-State-Drive (SSD) operate either at page or block granularity, with inevitable limitations in terms of memory requirement, performance, garbage collection, and scalability. To overcome these limitations, we proposed a novel space management and address mapping scheme for flash referred to as Z-MAP, which manages flash space at granularity of Zone. Each Zone consists of multiple numbers of flash blocks. Leveraging workload classification, Z-MAP explores Page-mapping Zone (Page Zone) to store random data and handle a large number of partial updates, and Block-mapping Zone (Block Zone) to store sequential data and lower the overall mapping table. Zones are dynamically allocated and a mapping scheme for a Zone is determined only when it is allocated. Z-MAP uses a small part of Flash memory or phase change memory as a streaming Buffer Zone to log data sequentially and migrate data into Page Zone or Block Zone based on workload classification. A two-level address mapping is designed to reduce the overall mapping table and address translation latency. Z-MAP classifies data before it is permanently stored into Flash memory so that different workloads can be isolated and garbage collection overhead can be minimized.

Z-MAP has been extensively evaluated by trace-driven simulation and a prototype implementation on OpenSSD. Our benchmark results conclusively demonstrate that Z-MAP can achieve up to 76% performance improvement, 81% mapping table reduction, and 88% garbage collection overhead reduction compared to existing Flash Translation Layer (FTL) schemes.
ATHENA
Authors: Pintus Ruggero , Yang Ying , Rushmeier Holly
Published: March 2015

Massive digital acquisition and preservation of deteriorating historical and artistic documents is of particular importance due to their value and fragile condition. The study and browsing of such digital libraries is invaluable for scholars in the Cultural Heritage field but requires automatic tools for analyzing and indexing these datasets. We present two completely automatic methods requiring no human intervention: text height estimation and text line extraction. Our proposed methods have been evaluated on a huge heterogeneous corpus of illuminated medieval manuscripts of different writing styles and with various problematic attributes, such as holes, spots, ink bleed-through, ornamentation, background noise, and overlapping text lines. Our experimental results demonstrate that these two new methods are efficient and reliable, even when applied to very noisy and damaged old handwritten manuscripts.
Gaze-Driven Video Re-Editing
Authors: Jain Eakta , Sheikh Yaser , Shamir Ariel , Hodgins Jessica
Published: March 2015

Given the current profusion of devices for viewing media, video content created at one aspect ratio is often viewed on displays with different aspect ratios. Many previous solutions address this problem by retargeting or resizing the video, but a more general solution would re-edit the video for the new display. Our method employs the three primary editing operations: pan, cut, and zoom. We let viewers implicitly reveal what is important in a video by tracking their gaze as they watch the video. We present an algorithm that optimizes the path of a cropping window based on the collected eyetracking data, finds places to cut, and computes the size of the cropping window. We present results on a variety of video clips, including close-up and distant shots, and stationary and moving cameras. We conduct two experiments to evaluate our results. First, we eyetrack viewers on the result videos generated by our algorithm, and second, we perform a subjective assessment of viewer preference. These experiments show that viewer gaze patterns are similar on our result videos and on the original video clips, and that viewers prefer our results to an optimized crop-and-warp algorithm.
Data-Driven Color Manifolds
Authors: Nguyen Chuong H. , Ritschel Tobias , Seidel Hans-Peter
Published: March 2015

Color selection is required in many computer graphics applications, but can be tedious, as 1D or 2D user interfaces are employed to navigate in a 3D color space. Until now the problem was considered a question of designing general color spaces with meaningful (e.g., perceptual) parameters. In this work, we show how color selection usability improves by applying 1D or 2D color manifolds that predict the most likely change of color in a specific context. A typical use-case is manipulating the color of a banana; instead of presenting a 2D+1D RGB, CIE Lab, or HSV widget, our approach presents a simple 1D slider that captures the most likely change for this context. Technically, for each context, we learn a lower-dimensional manifold with varying density from labeled Internet examples. We demonstrate the increase in task performance of color selection in a user study.
Layered Light Field Reconstruction for Defocus Blur
Authors: Vaidyanathan Karthik , Munkberg Jacob , Clarberg Petrik , Salvi Marco
Published: March 2015

We present a novel algorithm for reconstructing high-quality defocus blur from a sparsely sampled light field. Our algorithm builds upon recent developments in the area of sheared reconstruction filters and significantly improves reconstruction quality and performance. While previous filtering techniques can be ineffective in regions with complex occlusion, our algorithm handles such scenarios well by partitioning the input samples into depth layers. These depth layers are filtered independently and then combined together, taking into account inter-layer visibility. We also introduce a new separable formulation of sheared reconstruction filters that achieves real-time preformance on a modern GPU and is more than two orders of magnitude faster than previously published techniques.
Interactive Material Design Using Model Reduction
Authors: Xu Hongyi , Li Yijing , Chen Yong , Barbič Jernej
Published: March 2015

We demonstrate an interactive method to create heterogeneous continuous deformable materials on complex three-dimensional meshes. The user specifies displacements and internal elastic forces at a chosen set of mesh vertices. Our system then rapidly solves an optimization problem to compute a corresponding heterogeneous spatial distribution of material properties using the Finite Element Method (FEM) analysis. We apply our method to linear and nonlinear isotropic deformable materials. We demonstrate that solving the problem interactively in the full-dimensional space of individual tetrahedron material values is not practical. Instead, we propose a new model reduction method that projects the material space to a low-dimensional space of material modes. Our model reduction accelerates optimization by two orders of magnitude and makes the convergence much more robust, making it possible to interactively design material distributions on complex meshes. We apply our method to precise control of contact forces and control of pressure over large contact areas between rigid and deformable objects for ergonomics. Our tetrahedron-based dithering method can efficiently convert continuous material distributions into discrete ones and we demonstrate its precision via FEM simulation. We physically display our distributions using haptics, as well as demonstrate how haptics can aid in the material design. The produced heterogeneous material distributions can also be used in computer animation applications.