bluuebunny/crossref_metadata_2025_split huggingface dataset:
Current Accounts in the Long Run and the Intertemporal Approach: A Panel Data Investigation
Authors: Cerrato Mario , Kalyoncu Huseyin , Naqvi Naveed Hassan , Tsoukis Christopher 
Published: February 2014

AbstractThis paper is a theory‐based study of the long‐run determinants of the current account (CA). For many OECD economies after the Second World War, there has been more long‐run variation in the CA data than is emphasised by a ‘Permanent Income’ version of the intertemporal approach that is based on consumption‐smoothing and that allows only transitory CA imbalances. A theoretical model of the CA is developed, based on the ‘broader’ variant of the intertemporal approach that stresses the long‐term component of the CA. We find that some key theoretical predictions hold, while others fail, validating the approach but also pointing to its limitations.
Waste / Low Quality Heat Recovery and Utilization With Low Temperature Economizers
Authors: Preston John M. , Watson W. Reid , Jones Charles B. 
Published: February 2014

Modern combustion steam-electric plants are designed to recover as much heat as economically feasible from the combustion products. As a part of the continuing effort by utilities to increase plant efficiency, extracting low quality heat from the flue gas stream prior to discharge through the stack to the environment has become economically attractive. “Economic feasibility” is strongly dependent on the cost of the fuel as well as quality of the heat recovered. The economic feasibility of deploying low-temperature economizers to cool flue gas from coal-fired steam-electric plants to a temperature well below the sulfuric acid mist dew point is not commonly practiced but could have a number of salutary effects on unit operations including reduction in fuel use, reduction in water, reduction in fly ash resistivity upstream of cold-side electrostatic precipitators and enhanced mercury oxidation/capture.
Using a theoretical 600 MW (nominal) coal fired facility an additional 30.8 MW of electrical output is available with the installation of a Low Temperature Economizer. This represents a 1% improvement in the plant heat rate with an attractive payback period. The components required for this heat recovery sub-system are readily available and the technology has matured to a point where uncertainties are minimized.
In addition to improving the operation of the plant, Low Temperature Economizer can reduce emissions of SOx, NOx, Hg, PM and CO2. In a difficult regulatory environment reducing emissions while increasing plant performance is extremely beneficial. Furthermore Low Temperature Economizer lowers the volume of scrubber water required.
Cooling the flue gas leaving the air heater below the acid mist dew point is not commonly practiced. The corrosion potential of the condensed sulfuric acid is a major materials selection/maintenance challenge as is the potential for gas-side fouling of the heat exchange surface with fly ash.
Economic Design of Hybrid Wet-Dry Cooling Systems
Authors: Card R. W. 
Published: February 2014

A hybrid wet-dry cooling system can be designed for a large combined-cycle power plant.
A well-designed hybrid cooling system will provide reasonable net generation year-round, while using substantially less water than a conventional wet cooling tower. The optimum design for the hybrid system depends upon climate at the site, the price of power, and the price of water. These factors vary on a seasonal basis.
Two hypothetical power plants are modeled, using state-of-the-art steam turbines and hybrid cooling systems. The plants are designed for water-constrained sites incorporating typical weather data, power prices, and water prices.
The principles for economic designs of hybrid cooling systems are demonstrated.
Investigation of the Prediction Correlations for the Flow Through Rotating Orifices in the Gas Turbine Secondary Air Flow System
Authors: Prabhudharwadkar Deoras , Dweik Zain , Subramani A. , Krishnan R. Murali 
Published: February 2014

The secondary air flow system of a gas turbine cools and seals those parts of the turbine which would otherwise be exposed to the high temperatures, resulting in their life reduction or even failures. At the same time, excessive secondary air flow hinders the performance of the engine. Accurate analysis of the secondary system is therefore necessary to safeguard the reliable design of the engine and accurate life predictions. The secondary system is analyzed through the flow network analysis which comprises of chambers or cavities connected through flow passages or restrictions. There are significant number of locations where the air passes through stationary or rotating holes, e.g., the pre-swirl nozzles and the turbine blade receiver holes respectively.
The accuracy of the flow prediction depends on the accuracy of the orifice discharge coefficient. This paper provides a detailed assessment of the available discharge coefficient correlations. The discharge coefficient has been found to be dependent on the geometric parameters (viz., length, inlet radius, chamfer), and the amount of cross-flow at the orifice entrance. The cross-flow may result from the relative tangential velocity between the orifice and the air or the inclination of the inlet flow with respect to the orifice axis. In this study, it was found that the discharge coefficient correlations provide similar predictions for flows without any cross-flow. However, significant deviations are seen in the predictions for the cases involving cross-flow. To identify the most accurate correlation for secondary flow application, a thorough assessment was performed using the static and the rotating test data available in the literature. In addition to the comparison using available experimental data, a CFD study was performed to independently assess the correlations. This exercise led to the identification of the most suitable correlation for our application.
Optimization of Design and Operation of a Combined Heat and Power Plant, by Use of a 1D-Physical Model
Authors: Deneux Olivier , Péchiné Bruno , Fouquet Manon 
Published: February 2014

Many industries require heat or cold in their production plants. To meet these needs, companies usually equip their generation sites with combined heat and power plants.
The goal of the present study is to build an accurate 1D-physical model of a cogeneration plant and to use it to optimize the plant from design phase to operation phase. The study shows that using the Modelica language and a library of plant components such as ThermoSysPro are adequate for building a modular 1D-physical model. Once the model built, optimization tools were used for optimizing both design (component specification for allowing maximized profit and minimized investment) and operation (loads of turbines and engines for maximized profit).
Physical models may therefore be used for an optimization purpose. Moreover the developed tools may prove useful for engineers operating combined heat and power plants for monitoring and optimizing purposes.
Scaling Test Data to Predict Performance
Authors: Burke Jacqueline , Hunter Andrew , Nyquist Roger , Andrews Mike 
Published: February 2014

In the aerodynamic design of centrifugal compressors, it is possible to scale test data to predict the geometry (impeller diameter and tip width) necessary for a stage to meet a certain performance. There is not, however, a standard industry scaling method. The important points on the performance curve to consider in the scaling process are the scaling point, the surge point and the choke point. Choosing a scaling point is not objective and generally impellers are tested as part of a multistage machine where one stage is controlling, so the true surge and choke points are rarely known; these details make it difficult to depend on scaling alone for impeller design. Thus, impellers are often designed with one-dimensional (1-D) wheel sizing programs that rely on inexact slip and blockage models.
A method of scaling is introduced in this paper that allows a machine to be designed based solely on test data rather than a sizing program. This scaling method was verified by utilizing different sets of data to predict the geometry necessary to meet a stage performance curve; the results showed that when various data sets corresponding to different geometries were scaled to the same design point, the predicted geometries converged. The predicted geometry was also compared to the geometry generated by the 1-D wheel sizing program to verify that the method is reliable. This approach to scaling significantly improves the confidence in the predicted performance of new stages.
Structural Modification of a Power Plant’s River Water Intake to Minimize Ice Blockage
Authors: Michell Frank , Politano Marcela , Stallings Jeffrey , Wang Yushi 
Published: February 2014

Ice blockage of a power plant’s water intake is of paramount importance since it can lead to an unplanned shutdown of the intake compromising water supply and plant operation. American Electric Power’s (AEP) Conesville Power Plant historically controlled ice accumulation at the river intake by routing to the intake a portion of the warm water return from the condenser on the only operating “once-through” unit’s circulating water system. The unit operating with this once-through cooling system was retired at the end of 2012; thus, the plant lost the use of the condenser outlet/warm water return deicing flow at the river intake.
A numerical study was conducted to evaluate design alternatives to alleviate ice accumulation at the river intake. A numerical model to predict the ice transport and accumulation at the river intake was developed and used to understand the main phenomenon leading to intake blockage.
The effectiveness of mitigation measures was evaluated with the model. A mitigation plan consisting of intake modifications to be implemented during several phases is presented. In the first phase, large pipe openings are cut in the walls separating intake pump wells of previously retired units at the facility. In the second phase, a number of sediment control vanes previously placed in front of the intake are removed to facilitate downstream ice transport. A third phase, if needed to be implemented, involves removing additional sedimentation control vanes and cutting holes in the pump wells on the operating units.
The paper describes the model, discusses numerical results and presents the field experience after implementation of phase one.
Electronic transport properties of top-gated epitaxial-graphene nanoribbon field-effect transistors on SiC wafers
Authors: Hwang Wan Sik , Tahy Kristof , Zhao Pei , Nyakiti Luke O. , Wheeler Virginia D. , Myers-Ward Rachael L. , Eddy Charles R. , Kurt Gaskill D. , (Grace) Xing Huili , Seabaugh Alan , Jena Debdeep 
Published: February 2014

Top-gated epitaxial-graphene nanoribbon (GNR) field-effect transistors on SiC wafers were fabricated and characterized at room temperature. The devices exhibited extremely high current densities (∼10 000 mA/mm) due to the combined advantages of the one-dimensionality of GNRs and the SiC substrate. These advantages included good heat dissipation as well as the high optical phonon energy of the GNRs and SiC substrate. An analytical model explains the measured family of ID–VDS curves with a pronounced ‘kink’ at a high electric field. The effective carrier mobility as a function of the channel length was extracted from both the ID–VDS modeling and the maximum transconductance from the ID–VGS curve. The effective mobility decreased for small channel lengths (&lt;1 μm), exhibiting ballistic or quasiballistic transport properties.
Cardiac C‐arm computed tomography using a 3D + time ROI reconstruction method with spatial and temporal regularization
Authors: Mory Cyril , Auvray Vincent , Zhang Bo , Grass Michael , Schäfer Dirk , Chen S. James , Carroll John D. , Rit Simon , Peyrin Françoise , Douek Philippe , Boussel Loïc 
Published: February 2014

Purpose:Reconstruction of the beating heart in 3D + time in the catheter laboratory using only the available C‐arm system would improve diagnosis, guidance, device sizing, and outcome control for intracardiac interventions, e.g., electrophysiology, valvular disease treatment, structural or congenital heart disease. To obtain such a reconstruction, the patientˈs electrocardiogram (ECG) must be recorded during the acquisition and used in the reconstruction. In this paper, the authors present a 4D reconstruction method aiming to reconstruct the heart from a single sweep 10 s acquisition.Methods:The authors introduce the 4D RecOnstructiOn using Spatial and TEmporal Regularization (short 4D ROOSTER) method, which reconstructs all cardiac phases at once, as a 3D + time volume. The algorithm alternates between a reconstruction step based on conjugate gradient and four regularization steps: enforcing positivity, averaging along time outside a motion mask that contains the heart and vessels, 3D spatial total variation minimization, and 1D temporal total variation minimization.Results:4D ROOSTER recovers the different temporal representations of a moving Shepp and Logan phantom, and outperforms both ECG‐gated simultaneous algebraic reconstruction technique and prior image constrained compressed sensing on a clinical case. It generates 3D + time reconstructions with sharp edges which can be used, for example, to estimate the patientˈs left ventricular ejection fraction.Conclusions:4D ROOSTER can be applied for human cardiac C‐arm CT, and potentially in other dynamic tomography areas. It can easily be adapted to other problems as regularization is decoupled from projection and back projection.
Draft Genome Sequences of Two Cellulolytic
Paenibacillus
sp. Strains, MAEPY1 and MAEPY2, from Malaysian Landfill Leachate
Authors: Chua Patric , Yoo Hye-Seung , Gan Han Ming , Lee Sui-Mae 
Published: February 2014

ABSTRACT

We report the draft genome sequences of two
Paenibacillus
species with cellulose-degrading abilities isolated from landfill leachate. An array of genes putatively involved in cellulose degradation have been identified in both genome sequences, which can benefit various biotechnological industries.
ESwab as an Optional Collection Device for Use with the Affirm VPIII Microbial Test System
Authors: Rivers C. A. , Lee J. Y. , Sharples N. , Ledeboer N. A. , Schwebke J. R. 
Published: February 2014

ABSTRACT

The ESwab collection device was compared to the collection swab provided as part of the Affirm VPIII microbial identification test kit for testing vaginal specimens with the Affirm test system. There was excellent agreement between the two sampling devices for
Candida
spp.,
Gardnerella vaginalis
, and
Trichomonas vaginalis
.
Separate Evolution of Virulent Newcastle Disease Viruses from Mexico and Central America
Authors: Susta Leonardo , Hamal Krishna R. , Miller Patti J. , Cardenas-Garcia Stivalis , Brown Corrie C. , Pedersen Janice C. , Gongora Victor , Afonso Claudio L. 
Published: February 2014

ABSTRACTAn outbreak of Newcastle disease (ND) in poultry was reported in Belize in 2008. The characteristics of three virulent Newcastle disease virus (NDV) isolates from this outbreak (NDV-Belize-3/08, NDV-Belize-4/08, and NDV-Belize-12/08) were assessed by genomic analysis and by clinicopathological characterization in specific-pathogen-free (SPF) chickens. The results showed that all three strains belong to NDV genotype V and are virulent, as assessed by the intracerebral pathogenicity index and the polybasic amino acid sequence at the fusion protein cleavage site. In 4-week-old SPF chickens, NDV-Belize-3/08 behaved as a typical velogenic viscerotropic NDV strain, causing severe necrohemorrhagic lesions in the lymphoid organs, with systemic virus distribution. Phylogenetic analysis of multiple NDV genotype V representatives revealed that genotype V can be divided into three subgenotypes, namely, Va, Vb, and Vc, and that all tested Belizean isolates belong to subgenotype Vb. Furthermore, these isolates are nearly identical to a 2007 isolate from Honduras and appear to have evolved separately from other contemporary viruses circulating in Mexico, clustering into a new clade within NDV subgenotype Vb.
HIV Infection and Microbial Diversity in Saliva
Authors: Li Yihong , Saxena Deepak , Chen Zhou , Liu Gaoxia , Abrams Willam R. , Phelan Joan A. , Norman Robert G. , Fisch Gene S. , Corby Patricia M. , Dewhirst Floyd , Paster Bruce J. , Kokaras Alexis S. , Malamud Daniel 
Published: February 2014

ABSTRACT

Limited information is available about the effects of HIV and subsequent antiretroviral treatment on host-microbe interactions. This study aimed to determine the salivary microbial composition for 10 HIV-seropositive subjects, before and 6 months after highly active antiretroviral therapy (HAART), compared with that for 10 HIV-seronegative subjects. A conventional culture and two culture-independent analyses were used and consistently demonstrated differences in microbial composition among the three sets of samples. HIV-positive subjects had higher levels of total cultivable microbes, including oral streptococci, lactobacilli,
Streptococcus mutans
, and
Candida
, in saliva than did HIV-negative subjects. The total cultivable microbial levels were significantly correlated with CD4
+
T cell counts. Denaturing gradient gel electrophoresis (DGGE), which compared the overall microbial profiles, showed distinct fingerprinting profiles for each group. The human oral microbe identification microarray (HOMIM) assay, which compared the 16S rRNA genes, showed clear separation among the three sample groups.
Veillonella
,
Synergistetes
, and
Streptococcus
were present in all 30 saliva samples. Only minor changes or no changes in the prevalence of
Neisseria
,
Haemophilus
,
Gemella
,
Leptotrichia
,
Solobacterium
,
Parvimonas
, and
Rothia
were observed. Seven genera,
Capnocytophaga
,
Slackia
,
Porphyromonas
,
Kingella
,
Peptostreptococcaceae
,
Lactobacillus
, and
Atopobium
, were detected only in HIV-negative samples. The prevalences of
Fusobacterium
,
Campylobacter
,
Prevotella
,
Capnocytophaga
,
Selenomonas
,
Actinomyces
,
Granulicatella
, and
Atopobium
were increased after HAART. In contrast, the prevalence of
Aggregatibacter
was significantly decreased after HAART. The findings of this study suggest that HIV infection and HAART can have significant effects on salivary microbial colonization and composition.
Characterization of Ocular Methicillin-Resistant Staphylococcus epidermidis Isolates Belonging Predominantly to Clonal Complex 2 Subcluster II
Authors: Bispo Paulo J. M. , Hofling-Lima Ana Luisa , Pignatari Antonio C. C. 
Published: February 2014

ABSTRACT

Staphylococcus epidermidis
is an abundant member of the microbiota of the human skin and wet mucosa, which is commonly associated with sight-threatening infections in eyes with predisposing factors. Ocular
S. epidermidis
has become notorious because of its capability to form biofilms on different ocular devices and due to the evolving rates of antimicrobial resistance. In this study, the molecular epidemiology of 30 ocular methicillin-resistant
S. epidermidis
(MRSE) isolates was assessed using multilocus sequence typing (MLST). Antimicrobial resistance, accessory gene-regulator and staphylococcal cassette chromosome
mec
(SCC
mec
) types, biofilm formation, and the occurrence of biofilm-associated genes were correlated with MLST clonal complexes. Sequence types (STs) frequently found in the hospital setting were rarely found in our collection. Overall, 12 different STs were detected with a predominance of ST59 (30%), ST5 and ST6 (13.3% each). Most of the isolates (93.3%) belonged to the clonal complex 2 (CC2) and grouped mainly within subcluster CC2-II (92.9%). Isolates grouped within this subcluster were frequently biofilm producers (92.3%) with a higher occurrence of the
aap
(84.5%) and
bhp
(46.1%) genes compared to
ica
A (19.2%). SCC
mec
type IV (53.8%) was predominant within CC2-II strains, while 38.4% were nontypeable. In addition, CC2-II strains were frequently multidrug resistant (80.7%) and demonstrated to be particularly resistant to ciprofloxacin (80.8%), ofloxacin (77%), azithromycin (61.5%), and gentamicin (57.7%). Our findings demonstrate the predominance of a particular MRSE cluster causing ocular infections, which was associated with high rates of antimicrobial resistance and particularly the carriage of biofilm-related genes coding for proteinaceous factors implicated in biofilm accumulation.
Distribution of Strain Type and Antimicrobial Susceptibility of Escherichia coli Isolates Causing Meningitis in a Large Urban Setting in Brazil
Authors: Berman Hillary , Barberino Maria Goreth , Moreira Edson Duarte , Riley Lee , Reis Joice N. 
Published: February 2014

ABSTRACT

The clinical management of meningitis caused by
Escherichia coli
is greatly complicated when the organism becomes resistant to broad-spectrum antibiotics. We sought to characterize the antimicrobial susceptibilities, sequence types (ST), and presence of known drug resistance genes of
E. coli
isolates that caused meningitis between 1996 and 2011 in Salvador, Brazil. We then compared these findings to those for
E. coli
isolates from community-acquired urinary tract infections (UTI) that occurred during the same time period and in the same city. We found that 19% of
E. coli
isolates from cases of meningitis and less than 1% of isolates from UTI were resistant to third-generation cephalosporins. The sequence types of
E. coli
isolates from cases of meningitis included ST131, ST69, ST405, and ST62, which were also found among isolates from UTI. Additionally, among the
E. coli
isolates that were resistant to third-generation cephalosporins, we found genes that encode the extended-spectrum beta-lactamases CTX-M-2, CTX-M-14, and CTX-M-15. These observations demonstrate that compared to
E. coli
strains isolated from cases of community-acquired UTI, those isolated from cases of meningitis are more resistant to third-generation cephalosporins, even though the same sequence types are shared between the two forms of extraintestinal infections.
Vancomycin-Variable Enterococcus faecium:
In Vivo
Emergence of Vancomycin Resistance in a Vancomycin-Susceptible Isolate
Authors: Coburn Bryan , Low Donald E. , Patel Samir N. , Poutanen Susan M. , Shahinas Dea , Eshaghi Alireza , Willey Barbara M. , McGeer Allison 
Published: February 2014

ABSTRACT

We report the emergence of vancomycin resistance in a patient colonized with a
vanA
-containing,
vanRS
-negative isolate of
Enterococcus faecium
which was initially vancomycin susceptible. This is a previously undescribed mechanism of drug resistance with diagnostic and therapeutic implications.