bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comprehensive Reduction of Thermal Resistance in Air Cooled Condensers
Authors: Saleh Ahmad , Kapat Jayanta 
Published: October 2015

Restriction on water consumption is becoming an increasing problem for the power generation industry. As an alternative both to once-through cooling and to surface condenser/wet-cooling tower combination, utility companies and equipment manufacturers are considering, and even implementing, air-cooled condenser (ACC). However, the industry is quite reluctant to switch over to ACC for three important reasons: (a) lower power output, (b) higher capital cost, and (c) larger physical foot-print, all because of the same reason — it is not as efficient to transfer heat from condensing steam to air as it is to transfer to water. In other words, overall thermal resistance from condensing steam to the ambient air is significantly higher than to cooling water.
To get a clear and full understanding of the heat transfer process occur in air-cooling condenser, Detailed mathematical equations were derived to model the heat transfer process through the fined-tubes of the ACC. The total thermal resistance model was analyzed and investigated to identify the design components with highest affect in the process.
The paper proposes a viable cooling system based on novel heat pipe technology which addresses these problems. This technology employs boiling as the means to store and transfer heat energy. A detailed mathematical set of equations was derived to model the heat pipe thermal resistance. A comparison of the heat transfer performances of the ACC technology and the proposed method is presented.
The proposed cooling system suggests a solution for each of the three components of the thermal resistance, the super-hydrophobic coating of the steam ducts internal surfaces increased the condensing heat transfer rate by an order of magnitude, the proposed design of the heat pipes improved the external heat transfer, and the installation mechanism improves the fin efficiency by eliminating the contact resistance between steam duct and the heat pipe.
Post Mortem of a Feedwater Heater With Drains Cooler Failures
Authors: Svensson Eric , Halcomb D. Chad 
Published: October 2015

The Paradise Generation Station Unit 3 is a supercritical fossil plant with a 1,078 MW rated capacity. The #3B feedwater heater (FWH) is a two-zone (condensing and subcooling) horizontal FWH and is the second of four high pressure (HP) FWHs after the boiler feed pump in the “B” string, one of two HP FWH strings (See Figure A2 at the end of this paper for an outline drawing of the heater. The heater has 1447 SA-556-C2 Carbon Steel tubes, 3/4” OD × 0.085 min wall. The heater was built in late 2006/early 2007 and was installed in summer 2007.
After just a few years of operation, the #3B FWH experienced several failures at the entrance to the drain cooler (DC) zone. The #3A FWH, of identical construction and built and installed at the same time, did not show the same level of damage.
In order to determine the failure mechanisms involved, a post-mortem of the heater was performed. This paper shall discuss the post-mortem inspection conducted as well as the suspected and confirmed causes of failure in the heater.
Improvements in the Performance of a Subcooling Zone in a Feedwater Heater With Dual End Plate Design With Water Seal in Between
Authors: Nadig Ranga 
Published: October 2015

In a horizontal feedwater heater with a partial length subcooling zone the end plate located at the entrance to the subcooling zone is the only non-welded barrier that prevents the condensing zone steam from entering the subcooling zone. The end plate is usually two or three inches thick and the tube holes in the end plate are drilled to tolerances similar to that of the tubesheet. As the steam from condensing zone tries to enter the subcooling zone it condenses in the tight spaces between the active tube and the tube hole in the end plate forming a liquid barrier that prevents further ingress of steam into the subcooling zone. With usage and wear the gap between the active tube and the tube hole in the end plate increases thereby weakening the liquid barrier. The liquid barrier is completely lost when the tubes are plugged. Steam from condensing zone enters the subcooling zone and disrupts the performance of the subcooling zone, the performance of the feedwater heater and the efficiency of the power plant. This problem is faced by all horizontal feedwater heaters with subcooling zones that are in operation in power plants worldwide.
This loss of performance can be eliminated by employing the patent pending Maarky concept of “dual end plate subcooling zone with a water seal”. The “dual end plate subcooling zone with water seal” concept comprises of two end plates separated by a short distance. The gap between the two end plates is filled with condensate thereby forming a triple barrier to ingress of condensing zone steam into the subcooling zone. The performance of the subcooling zone and the longevity of the heater are preserved.
This paper discusses the design of subcooling zone in present day feedwater heaters, degradation of performance of subcooling zone and the improvements brought about by the patent pending Maarky concept of “dual end plate subcooling zone with water seal”.
Design of a 100 kW Concentrated Solar Power on Demand Volumetric Receiver With Integral Thermal Energy Storage Prototype
Authors: Gil Antoni , Codd Daniel S. , Zhou Lei , Trumper David , Campbell Ronald B. , Grange Benjamin , Calvet Nicolas , Armstrong Peter , Slocum Alexander H. 
Published: October 2015

A new concept of Thermal Energy Storage (TES) system based on current available technologies is being developed under the framework of the Masdar Institute (MI) and Massachusetts Institute of Technology (MIT) collaborative Flagship Program. The key feature of this concept lies on concentrating sun light directly on the molten salt storage tank, avoiding the necessity of pumping the salts to the top of a tower thereby avoiding thermal losses and pumping and electric tracing needs inherent in most conventional CSP plants.
This Concentrated Solar Power on Demand (CSPonD) volumetric receiver/TES unit prototype will be tested in the existing MI heliostat field and beam down tower in Abu Dhabi (UAE) which will collect and redirect solar energy to an upwards-facing final optical element (FOE). These energy will be concentrated on the aperture of the prototype designed to store 400 kWh of energy allowing 16 hours of continuous production after sunset using Solar Salt (60%NaNO3 + 40%KNO3) as storage material.
The tank is divided in two volumes: one cold in the bottom region, where Solar Salt is at 250 °C and another hot on the upper region, at 550 °C. A moving divider plate with active control separates both volumes. The plate includes mixing enhancement features to help with convection on the hot volume of salts.
It’s expected that results will demonstrate the technical feasibility and economic viability of this concept allowing its scale up at commercial size.
Aeroelastic Impact of a Circumferentially Varying Tip Gap
Authors: Canon David , Kapat Jayanta 
Published: October 2015

The tip leakage flow in axial compressors is a significant factor in engine performance and a subject of investigation over the last several decades. Many studies have already shown that the vortices generated by this tip leakage can have a negative impact on the surrounding flow field and overall performance, and lead to excitations as well. This study examines the effect of these vortices on aeroelasticity, specifically, the effect of a circumferentially varying tip gap; such as that produced by casing ovalization.
For this paper, a single passage, structured grid, CFD model of a compressor’s mid-stage rotor-stator configuration was analyzed using StarCCM+’s harmonic balance solver. This was a frequency domain calculation, which provided significant time savings relative to the more conventional time accurate approach. The vibratory results from an Abaqus model were incorporated into the CFD in order to calculate the aerodynamic work. The calculation modeled a circumferentially varying tip gap representative of what is seen in a real engine, and results were compared to solutions from models with circumferentially constant gaps. Furthermore, test data from an industrial gas turbine was utilized in order to recreate realistic levels of tip gap variation, as well as to validate the mechanical model’s vibratory results. The calculations showed that for the gap variation imposed, the work per cycle was increased by 59% relative to a case with constant gaps.
Design of a Multiphase Pump Test Laboratory Allowing to Perform Flow Visualization and Instability Analysis
Authors: Serena Alberto , Bakken Lars E. 
Published: October 2015

This paper describes the design and construction of an advanced laboratory setup allowing the study of a multiphase pump model.
The main objective is to relate the pump behaviour and instabilities to flow phenomena in the hydraulic channels, studying the machine ability to handle with multiphase flows and transient conditions and the influence of operating parameters (pump speed, flow rates, broad range of gas-liquid compositions, and suction pressure) on the machine performance and operating range, described through performance maps.
To perform this study, different analysis techniques will be employed and compared: experimental test results, analytical model predictions and numerical tool validation. The key role is played by the accurate visual investigation of the main parameters characterizing multiphase flow (bubble size and shape, liquid film thickness, etc.); gas/liquid interface, flow morphology and flow pattern transition are observed and will serve later to validate the prediction models. In addition, the measurement of dynamic pressure fluctuations helps understanding the transient nature of two-phase flow phenomena.
The test facility allows different fine adjustments, to study the effects of upstream flow conditions and clearance sizes on performance and stability.
This first paper focuses on the laboratory test facility, reporting the design process and the results of the experimental work.
Pharmacodynamics of Isavuconazole in a Dynamic
In Vitro
Model of Invasive Pulmonary Aspergillosis
Authors: Box Helen , Livermore Joanne , Johnson Adam , McEntee Laura , Felton Timothy W. , Whalley Sarah , Goodwin Joanne , Hope William W. 
Published: October 2015

ABSTRACT

Isavuconazonium sulfate is a novel triazole prodrug that has been recently approved for the treatment of invasive aspergillosis by the FDA. The active moiety (isavuconazole) has a broad spectrum of activity against many pathogenic fungi. This study utilized a dynamic
in vitro
model of the human alveolus to describe the pharmacodynamics of isavuconazole against two wild-type and two previously defined azole-resistant isolates of
Aspergillus fumigatus
. A human-like concentration-time profile for isavuconazole was generated. MICs were determined using CLSI and EUCAST methodologies. Galactomannan was used as a measure of fungal burden. Target values for the area under the concentration-time curve (AUC)/MIC were calculated using a population pharmacokinetics-pharmacodynamics (PK-PD) mathematical model. Isolates with higher MICs required higher AUCs in order to achieve maximal suppression of galactomannan. The AUC/MIC targets necessary to achieve 90% probability of galactomannan suppression of <1 were 11.40 and 11.20 for EUCAST and CLSI, respectively.
In Vivo
Synergy of Amphotericin B plus Posaconazole in Murine Aspergillosis
Authors: Martin-Vicente Adela , Capilla Javier , Guarro Josep 
Published: October 2015

ABSTRACT

Aspergillus fumigatus
is the main mold causing invasive fungal infection that shows high mortality rates. Therapeutic failure and the increase in drug resistance make it necessary to explore alternative treatments for this infection. We have evaluated the efficacy of amphotericin B at 0.8 mg/kg or 0.3 mg/kg of body weight combined with 40 mg/kg of posaconazole against three
A. fumigatus
isolates in a murine model of disseminated infection. The combination of the polyene and the azole led to a greater increase in survival and a significantly greater reduction in tissue burden than monotherapies.
Modification of the Host Cell Lipid Metabolism Induced by Hypolipidemic Drugs Targeting the Acetyl Coenzyme A Carboxylase Impairs West Nile Virus Replication
Authors: Merino-Ramos Teresa , Vázquez-Calvo Ángela , Casas Josefina , Sobrino Francisco , Saiz Juan-Carlos , Martín-Acebes Miguel A. 
Published: October 2015

ABSTRACT
West Nile virus (WNV) is a neurotropic flavivirus transmitted by the bite of mosquitoes that causes meningitis and encephalitis in humans, horses, and birds. Several studies have highlighted that flavivirus infection is highly dependent on cellular lipids for virus replication and infectious particle biogenesis. The first steps of lipid synthesis involve the carboxylation of acetyl coenzyme A (acetyl-CoA) to malonyl-CoA that is catalyzed by the acetyl-CoA carboxylase (ACC). This makes ACC a key enzyme of lipid synthesis that is currently being evaluated as a therapeutic target for different disorders, including cancers, obesity, diabetes, and viral infections. We have analyzed the effect of the ACC inhibitor 5-(tetradecyloxy)-2-furoic acid (TOFA) on infection by WNV. Lipidomic analysis of TOFA-treated cells confirmed that this drug reduced the cellular content of multiple lipids, including those directly implicated in the flavivirus life cycle (glycerophospholipids, sphingolipids, and cholesterol). Treatment with TOFA significantly inhibited the multiplication of WNV in a dose-dependent manner. Further analysis of the antiviral effect of this drug showed that the inhibitory effect was related to a reduction of viral replication. Furthermore, treatment with another ACC inhibitor, 3,3,14,14-tetramethylhexadecanedioic acid (MEDICA 16), also inhibited WNV infection. Interestingly, TOFA and MEDICA 16 also reduced the multiplication of Usutu virus (USUV), a WNV-related flavivirus. These results point to the ACC as a druggable cellular target suitable for antiviral development against WNV and other flaviviruses.
Bioassay for Determining Voriconazole Serum Levels in Patients Receiving Combination Therapy with Echinocandins
Authors: Siopi Maria , Neroutsos Efthymios , Zisaki Kalliopi , Gamaletsou Maria , Pirounaki Maria , Tsirigotis Panagiotis , Sipsas Nikolaos , Dokoumetzidis Aristides , Goussetis Evgenios , Zerva Loukia , Valsami Georgia , Meletiadis Joseph 
Published: October 2015

ABSTRACT

Voriconazole levels were determined with high-performance liquid chromatography (HPLC) and a microbiological agar diffusion assay using a
Candida parapsilosis
isolate in 103 serum samples from an HPLC-tested external quality control program (
n
= 39), 21 patients receiving voriconazole monotherapy (
n
= 39), and 7 patients receiving combination therapy (
n
= 25). The results of the bioassay were correlated with the results obtained from the external quality control program samples and with the HPLC results in sera from patients on voriconazole monotherapy and on combination therapy with an echinocandin (Spearman's rank correlation coefficient [
r
s
], > 0.93; mean ± standard error of the mean [SEM] % difference, <12% ± 3.8%).
In Vitro
Activity of Ceftaroline against Staphylococcus aureus Isolated in 2012 from Asia-Pacific Countries as Part of the AWARE Surveillance Program
Authors: Biedenbach Douglas J. , Alm Richard A. , Lahiri Sushmita D. , Reiszner Edina , Hoban Daryl J. , Sahm Daniel F. , Bouchillon Samuel K. , Ambler Jane E. 
Published: October 2015

ABSTRACT

Ceftaroline, the active metabolite of the prodrug ceftaroline-fosamil, is an advanced-generation cephalosporin with activity against methicillin-resistant
Staphylococcus aureus
(MRSA). This investigation provides
in vitro
susceptibility data for ceftaroline against 1,971
S. aureus
isolates collected in 2012 from seven countries (26 centers) in the Asia-Pacific region as part of the Assessing Worldwide Antimicrobial Resistance and Evaluation (AWARE) program. Broth microdilution as recommended by the CLSI was used to determine susceptibility. In all, 62% of the isolates studied were MRSA, and the ceftaroline MIC
90
for all
S. aureus
isolates was 2 μg/ml (interpretive criteria: susceptible, ≤1 μg/ml). The overall ceftaroline susceptibility rate for
S. aureus
was 86.9%, with 100% of methicillin-sensitive
S. aureus
isolates and 78.8% of MRSA isolates susceptible to this agent. The highest percentages of ceftaroline-nonsusceptible MRSA isolates came from China (47.6%), all of which showed intermediate susceptibility, and Thailand (37.1%), where over half (52.8%) of isolates were resistant to ceftaroline (MIC, 4 μg/ml). Thirty-eight ceftaroline-nonsusceptible isolates (MIC values of 2 to 4 μg/ml) were selected for molecular characterization. Among the isolates analyzed, sequence type 5 (ST-5) was the most common sequence type encountered; however, all isolates analyzed from Thailand were ST-228. Penicillin-binding protein 2a (PBP2a) substitution patterns varied by country, but all isolates from Thailand had the Glu
239
Lys substitution, and 12 of these also carried an additional Glu
447
Lys substitution. Ceftaroline-fosamil is a useful addition to the antimicrobial agents that can be used to treat
S. aureus
infections. However, with the capability of this species to develop resistance to new agents, it is important to recognize and monitor regional differences in trends as they emerge.
Memory B Cells Encode Neutralizing Antibody Specific for Toxin B from the Clostridium difficile Strains VPI 10463 and NAP1/BI/027 but with Superior Neutralization of VPI 10463 Toxin B
Authors: Devera T. Scott , Lang Gillian A. , Lanis Jordi M. , Rampuria Pragya , Gilmore Casey L. , James Judith A. , Ballard Jimmy D. , Lang Mark L. 
Published: October 2015

ABSTRACT

Secreted toxin B (TcdB) substantially contributes to the pathology observed during
Clostridium difficile
infection. To be successfully incorporated into a vaccine, TcdB-based immunogens must stimulate the production of neutralizing antibody (Ab)-encoding memory B cells (Bmem cells). Despite numerous investigations, a clear analysis of Bmem cellular responses following vaccination against TcdB is lacking. B6 mice were therefore used to test the ability of a nontoxigenic C-terminal domain (CTD) fragment of TcdB to induce Bmem cells that encode TcdB-neutralizing antibody. CTD was produced from the historical VPI 10463 strain (CTD1) and from the hypervirulent strain NAP1/BI/027 (CTD2). It was then demonstrated that CTD1 induced strong recall IgG antibody titers, and this led to the development of functional Bmem cells that could be adoptively transferred to naive recipients. Bmem cell-driven neutralizing Ab responses conferred protection against lethal challenge with TcdB1. Further experiments revealed that an experimental adjuvant (Imject) and a clinical adjuvant (Alhydrogel) were compatible with Bmem cell induction. Reactivity of human Bmem cells to CTD1 was also evident in human peripheral blood mononuclear cells (PBMCs), suggesting that CTD1 could be a good vaccine immunogen. However, CTD2 induced strong Bmem cell-driven antibody titers, and the CTD2 antibody was neutralizing
in vitro
, but its protection against lethal challenge with TcdB2 was limited to delaying time to death. Therefore, CTD from different
C. difficile
strains may be a good immunogen for stimulating B cell memory that encodes
in vitro
neutralizing Ab but may be limited by variable protection against intoxication
in vivo
.
Gliding Direction of Mycoplasma mobile
Authors: Morio Hanako , Kasai Taishi , Miyata Makoto 
Published: October 2015

ABSTRACT

Mycoplasma mobile
glides in the direction of its cell pole by a unique mechanism in which hundreds of legs, each protruding from its own gliding unit, catch, pull, and release sialylated oligosaccharides fixed on a solid surface. In this study, we found that 77% of cells glided to the left with a change in direction of 8.4° ± 17.6° μm
−1
displacement. The cell body did not roll around the cell axis, and elongated, thinner cells also glided while tracing a curved trajectory to the left. Under viscous conditions, the range of deviation of the gliding direction decreased. In the presence of 250 μM free sialyllactose, in which the binding of the legs (i.e., the catching of sialylated oligosaccharides) was reduced, 70% and 30% of cells glided to the left and the right, respectively, with changes in direction of ∼30° μm
−1
. The gliding ghosts, in which a cell was permeabilized by Triton X-100 and reactivated by ATP, glided more straightly. These results can be explained by the following assumptions based on the suggested gliding machinery and mechanism: (i) the units of gliding machinery may be aligned helically around the cell, (ii) the legs extend via the process of thermal fluctuation and catch the sialylated oligosaccharides, and (iii) the legs generate a propulsion force that is tilted from the cell axis to the left in 70% and to the right in 30% of cells.

IMPORTANCE
Mycoplasmas are bacteria that are generally parasitic to animals and plants. Some
Mycoplasma
species form a protrusion at a pole, bind to solid surfaces, and glide. Although these species appear to consistently glide in the direction of the protrusion, their exact gliding direction has not been examined. This study analyzed the gliding direction in detail under various conditions and, based on the results, suggested features of the machinery and the mechanism of gliding.
Relationship between cardiovascular health score and year-to-year blood pressure variability in China: a prospective cohort study
Authors: An Shasha , Bao Minghui , Wang Yang , Li Zhifang , Zhang Wenyan , Chen Shuohua , Li Junjuan , Yang Xinchun , Wu Shouling , Cai Jun 
Published: October 2015

ObjectivesOn the basis of cardiovascular health factors and behaviours, the American Heart Association proposed the Cardiovascular Health Score (CHS). It has been widely used to estimate the cardiovascular health status of individuals. The aim of this study was to investigate the relationship between CHS and year-to-year blood pressure variability (BPV).DesignProspective cohort study.SettingsWe stratified participants into two groups by gender: first group, female group; second group, male group. The relationship between CHS and year-to-year blood pressure variability were analysed.ParticipantsA total of 41 613 individuals met the inclusion criteria (no history of stroke, transient ischaemic attack, myocardial infarction, malignant tumour or atrial fibrillation) and had complete blood pressure data.ResultsThe coefficient of the variation of systolic blood pressure (SCV) was 8.33% in the total population and 8.68% and 8.22% in female and male groups, respectively (p<0.05). Multivariable linear regression analysis revealed that higher CHS was inversely associated with increasing year-to-year BPV, which persisted after adjusting for baseline systolic blood pressure and other risk factors. Each SD increase in CHS could lead to a 0.016SD decrease in SCV (p<0.05).ConclusionsIn summary, CHS was inversely related to year-to-year BPV, which suggested that a healthy lifestyle may contribute to better blood pressure management.