bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Critical Comparison of Numerical and Experimental Results for the Examination of a Cascade Consisting of NACA 65-010 1% Profiles
Authors: Baum Andreas , Berger Constantin , Landfester Christian , Böhle Martin 
Published: October 2017

Numerical and experimental investigations through different spans of the rotor are a common approach in turbo machinery design. As the aerodynamic quality of rotor blades is crucial for turbo machinery’s efficiency, mass-averaged loss coefficients ζ and turning angles Δβ are of particular interest. Using the example of commonly used NACA-65 profiles, a comparison between the results obtained by those methods should investigate whether Computational Fluid Dynamics (CFD) applying the Transition SST turbulence model delivers sufficiently accurate results regarding both 2D and 3D modeling approaches. The comparison is supplemented by the singularity method based on the potential theory as well as historical data provided by NACA.
While CFD produced a noticeable offset for some angle configurations, the 2D results of Δβ were in good agreement for singularity method, historical data and experimental investigations on the center line of the cascade supporting the validity of the measurement. Although significant deviations were also found for ζ, it can be stated that CFD reproduced the qualitative course sufficiently for both variables considered. A similar picture emerges from the 3D comparison: Despite noticeable deviations in quantitative terms, a good correspondence was found for both variables regarding local and mass-averaged values.
An Immersed Boundary Method in OpenFOAM for Arbitrarily Shaped Particles in the Shear Flow Field of Centrifugal Separators
Authors: Buerger Markus , Kumar Chethan Mohan , Janoske Uwe 
Published: October 2017

In the multiphase simulation of material handling and filtration processes the coupling between the fluid phase, which imposes aero- or hydrodynamic forces onto the particles, and the particulate matter, which in turn impose momentum into the fluid, is of major importance. Conventional simulation methods such as CFD-DEM-coupling are based upon empirical and analytical drag models. Moreover, they have the degradation of particles to point masses in common. Thus empirical modeling neglects the microscopic details that are essential to a profound understanding of micro scale processes and accurate macro scale simulation results.
A new simulation model which is built upon numerical simulation methods like CFD and the immersed boundary method is developed for OpenFOAM®. It is capable of fully discretizing the geometry of arbitrarily shaped bodies.
This work demonstrates the application of our simulation model to the multiphase flow in the near wall shear flow field of centrifugal separators. The validation of the model regarding particle drag and spin of variously shaped particles in the shear flow shows that the particle shape determines essentially the process of settling, separation and resuspension.
Study on Vortex Generators for Control of Attached Cavitation
Authors: Che Bangxiang , Wu Dazhuan 
Published: October 2017

Attached cavitation is a type of common cavitation phenomenon in fluid machinery. It is important to develop methods to control its generation. From the view of cavitation inception, the generation of attached cavitation is greatly influenced by the separated boundary layer upstream of cavitation detachment. In this research, a row of microscopic delta-shaped counter-rotating vortex generators (VGs) was applied on the leading edge of the NACA0015 hydrofoil in order to suppress the boundary layer separation and then suppress the generation of attached cavitation.
The application of VGs fixed the position of cavitation inception on hydrofoil thus the sheet cavitation became more stable and the cloud cavity shed from hydrofoil with trim trailing edge more regularly. It was found that cavitation inception always appeared adjacent to VGs due to the low pressure in the corner of streamwise vortices induced by VGs. Hydrofoil with VGs showed an entirely different cavitation morphology on the leading edge. A row of separate microscopic vortex cavitation was induced by the counter-rotating vortices firstly. With the lower the height of VGs, the longer the length of these vortex cavitation due to the weaker interaction between vortices and main flow. Following the vortex cavitation, the attached cavitation was developing, but without typical “finger” structure anymore.
Cryo-Adsorbent Hydrogen Storage Systems for Fuel Cell Vehicles
Authors: Tamburello David , Hardy Bruce , Corgnale Claudio , Sulic Martin , Anton Donald 
Published: October 2017

Numerical models for the evaluation of cryo-adsorbent based hydrogen (H2) storage systems for fuel cell vehicles were developed and validated against experimental data. These models simultaneously solve the equations for the adsorbent thermodynamics together with the conservation equations for heat, mass, and momentum. The models also use real gas thermodynamic properties for hydrogen. Model predictions were compared to data for charging and discharging both activated carbon and MOF-5™ systems. Applications of the model include detailed finite element analysis simulations and full vehicle-level system analyses. The full system models were used to compare prospective system design performance given specific options, such as the adsorbent materials, pressure vessel types, internal heat exchangers, and operating conditions. The full vehicle model, which also allows the user to compare adsorbent systems with compressed gas, metal hydride, and chemical hydrogen storage systems, is based on an 80 kW fuel cell with a 20 kW battery evaluated using standard drive cycles.
This work is part of the Hydrogen Storage Engineering Center of Excellence (HSECoE), which brings materials development and hydrogen storage technology efforts together to address onboard hydrogen storage in light duty vehicle applications. The HSECoE spans the design space of the vehicle requirements, balance of plant requirements, storage system components, and materials engineering. Theoretical, computational, and experimental efforts are combined to evaluate, design, analyze, and scale potential hydrogen storage systems and their supporting components against the Department of Energy (DOE) 2020 and Ultimate Technical Targets for Hydrogen Storage Systems for Light Duty Vehicles.
Study on the Transient Characteristics of Pump During the Starting Process With Assisted Valve
Authors: Li Qiao , Wu Peng , Wu Dazhuan 
Published: October 2017

Among the various transient operations, the startup process of a centrifugal pump brings attention to a number of practical issues. A representative application of the startup process is the underwater launch, which requires transient high pressure and high flowrate during a very short time.
Due to the rotational inertia of the pump and motor, the dynamic response of the pump is slow, so the rotational speed cannot reach the design point rapidly. To get a high response of the starting process, a throttle valve is installed in the downstream of the pump. The valve keeps closed before the rotational speed of the pump reaches a certain point. It is important to investigate the transient behavior of pump during such transient operations.
In this paper, experiment and numerical simulation are implemented to study the external transient hydrodynamic performance and the internal flow of the pump during the transient process. Different operating schemes of the pump and valve are designed to find the best coordinated modes.
The contents and conclusions of the current work can provide references for the performance prediction, design optimization and fluid control of the pump and valve during the transient process.
Design of a Dual Propeller Micro-Pump in Conjunction With Flared TCPC for Cavopulmonary Assist in Fontan Patients
Authors: Jagani Jakin , Untaroiu Alexandrina 
Published: October 2017

A single ventricular physiology of the human heart caused by a dysfunctional right ventricle is usually treated with the three-stage Fontan operation. The outcome of this operation is an extra-cardiac total cavopulmonary connection (TCPC) which supplies the deoxygenated blood from the body to the lungs by directly connecting the inferior and superior vena cava (IVC and SVC) to the left and right pulmonary arteries (LPA and RPA). However, the situation is worsened due to non-physiologic flow conditions and pressure loss inside the cavopulmonary track, which ultimately calls for a heart transplantation. A modest pressure rise of 5–6 mm Hg will help to regain the normal physiology of the patient. In order to achieve this, a conceptual design of a dual propeller pump inside a flared TCPC is developed and studied.
In order to provide a modest pressure rise, a blood pumping device was inserted inside the flared TCPC connection which consisted of two propellers, each placed in the SVC and the IVC and connected by a single shaft. The IVC and the SVC propellers were designed to rotate at the same rotational speed, having the same pressure rise but different blood inflow rate. The equal pressure rise across both the propellers was necessary at the design speed and flow rate to prevent any blood flow into the opposite vena cava. The TCPC-dual propeller conjunction was examined for the hydraulic performance and the flow pattern inside the TCPC using the 3D-CFD simulations on Ansys-CFX. The effect of axial distance between the two propellers on the blood flow interference and energy loss was also studied to select an optimal separation distance between them.
The introduction of dual propeller pump inside the flared TCPC led to a pressure rise of 2–15 mm Hg at a total flow rate of 4.5 lpm (63% from IVC and 37% from SVC) with the rotational speed ranging from 6000–12000 rpm. It was seen that an axial separation of 70 mm between the two propellers provided the best performance in terms of flow interference and energy loss.
A dual propeller pump assembled with an optimized TCPC could provide the required pressure rise for a particular age group of patients with univentricular Fontan physiology. The ability of dual micro-propeller pump to provide the required pressure rise will help to augment the cavopulmonary flow and hence help to regain the normal flow physiology as that witnessed by a human with biventricular circulation.
Dispersion of Shock Wave Transmitted Into Non-Uniform Materials
Authors: Kobayashi Susumu , Henmi Hiroki 
Published: October 2017

When a shock wave is incident on an obstacle, it is not only reflected back but also transmitted into the obstacle itself. The transmitted shock wave has not been fully investigated so far, compared with the reflected shock wave. In actual situations, the behavior and the characteristics of the transmitted shock wave are also of importance. In battlefields, human bodies are often subject to explosions and resulting shock waves. In particular, severe damage can be caused when a shock wave is transmitted into the human brain.
In the present study, we conducted experiments to investigate the behavior and intensity of a shock wave, after it is transmitted into various materials. The materials used were sintered metal, silicone, and polyethylene foam. They were fixed on a specially devised model with a cavity, by which the resulting wave after a shock wave is transmitted could be observed. In order to understand what is happening in sintered metal, a 2-D model made of straws was devised and used.
The Effect of Temperature on Water Cavitation Phenomena in Converging-Diverging Nozzle Flow
Authors: Ahmed Zayed , Beck B. Terry , Hosni Mohammad H. 
Published: October 2017

A vapor-compression refrigeration cycle typically uses standard refrigerants as the working fluid. Traditional refrigerants, however, have been associated with Ozone level Depletion Potential (ODP) and significant Global Warming Potential (GWP). An innovative cooling technology has been investigated using sonic multi-phase flow in a critical-flow nozzle to create a low-pressure and low-temperature region for heat absorption. The strength of the new technology is its potential to produce cooling using water and/or other working fluids with low ODP and GWP. While the full potential for using water as the working fluid may not be fully-realized, because of property limitations still under investigation, water still provides a very useful media for investigating the underlying cavitation phenomena for the development of the new technology.
As part of ongoing research into the potential cooling capacity of the cavitation phenomena, cavitation in a converging-diverging nozzle is being investigated using water as the working fluid. Cavitation in a fluid is the formation of the vapor phase from the liquid phase by reduction in the pressure of the fluid below its saturated vapor pressure. Due to the constricting nature of the throat of a converging-diverging nozzle, the liquid water velocity at the throat is increased and the local absolute pressure can drop to values below the saturated vapor pressure of water at a given temperature; thus, causing the fluid to cavitate.
The effect of water temperature on both the onset of the cavitation within the nozzle, and the resulting length of the cavitation region within the nozzle, are the subject of the current paper. Flow Visualization using a high speed digital camera under these different operating conditions was aimed at investigating the region of cavitation onset, which also appears to be associated with the region of boundary layer separation just downstream of the throat of the nozzle. The length of the two phase region at different operating temperatures was measured and it was observed that as the temperature of the fluid was increased, the length of two-phase region before it condensed into single-phase liquid became longer. Experimental results and analysis are presented which also show that near the onset of cavitation, the flowrate can likely go well beyond a choking condition without cavitating, and can remain in this metastable state for an extended amount of time before nucleating (cavitating) into a stable state. In particular, analysis indicates that significantly negative absolute pressures can likely be achieved within the nozzle, suggesting the presence of tension in the liquid phase just prior to cavitation.
Design of a Controllable One-Meter Scale Research Wind Turbine
Authors: Cole Samuel , Hess Gavin , Wosnik Martin 
Published: October 2017

A research wind turbine of one meter diameter was designed for the UNH Flow Physics Facility (FPF), a very large flow physics quality turbulent boundary layer wind tunnel (W 6m, H 2.7m, L 72m), which provides excellent spatial and temporal resolution, low flow blockage and allows measurements of turbine wakes far downstream due its long fetch.
The initial turbine design was carried out as an aero-servo model of the NREL 5MW reference turbine, with subsequent modifications to both the hub to accommodate blade mounting and pitch-adjustment, and increases in model blade chord to achieve sufficiently high Reynolds numbers. A trade-off study of turbine design parameters in scale space was conducted.
Several candidate airfoil profiles were evaluated numerically with the goal to reach Reynolds-number independence in turbine performance in the target operating range. The model turbine will achieve Reynolds numbers based on blade chord, an important consideration for airfoil performance and near-wake evolution, greater than 100,000, and Reynolds numbers based on turbine diameter, important for far-wake transport, on the order of 1,000,000. The blockage ratio is less than 5% based on swept area.
A motor and controller combination was implemented that allows to precisely prescribe the turbine tip-speed ratio (at maximum power coefficient for optimum blade chord), which can remain stable and absorb the generated electric power for long periods of time. The turbine nacelle was designed with a blade mounting mechanism which allows for precise manual adjustment of blade pitch angle, while allowing for future implementation of actuated pitch control.
The O(1m) turbine scale is viewed as a cost-effective compromise between size, driven by the need for sufficiently high Reynolds number, and the need for detailed measurements for significant distances downstream of the turbine under controlled conditions.
In Vitro
Activity and MIC of Sitafloxacin against Multidrug-Resistant and Extensively Drug-Resistant Mycobacterium tuberculosis Isolated in Thailand
Authors: Leechawengwongs Manoon , Prammananan Therdsak , Jaitrong Sarinya , Billamas Pamaree , Makhao Nampueng , Thamnongdee Nongnard , Thanormchat Arirat , Phurattanakornkul Arisa , Rattanarangsee Somcharn , Ratanajaraya Chate , Disratthakit Areeya , Chaiprasert Angkana 
Published: October 2017

ABSTRACT

New fluoroquinolones (FQs) have been shown to be more active against drug-resistant
Mycobacterium tuberculosis
strains than early FQs, such as ofloxacin. Sitafloxacin (STFX) is a new fluoroquinolone with
in vitro
activity against a broad range of bacteria, including
M. tuberculosis
. This study aimed to determine the
in vitro
activity of STFX against all groups of drug-resistant strains, including multidrug-resistant
M. tuberculosis
(MDR
M. tuberculosis
), MDR
M. tuberculosis
with quinolone resistance (pre-XDR), and extensively drug-resistant (XDR) strains. A total of 374 drug-resistant
M. tuberculosis
strains were tested for drug susceptibility by the conventional proportion method, and 95 strains were randomly submitted for MIC determination using the microplate alamarBlue assay (MABA). The results revealed that all the drug-resistant strains were susceptible to STFX at a critical concentration of 2 μg/ml. Determination of the MIC
90
s of the strains showed different MIC levels; MDR
M. tuberculosis
strains had a MIC
90
of 0.0625 μg/ml, whereas pre-XDR and XDR
M. tuberculosis
strains had identical MIC
90
s of 0.5 μg/ml. Common mutations within the quinolone resistance-determining region (QRDR) of
gyrA
and/or
gyrB
did not confer resistance to STFX, except that double mutations of GyrA at Ala90Val and Asp94Ala were found in strains with a MIC of 1.0 μg/ml. The results indicated that STFX had potent
in vitro
activity against all the groups of drug-resistant
M. tuberculosis
strains and should be considered a new repurposed drug for treatment of multidrug-resistant and extensively drug-resistant TB.
Methionine Ameliorates Polymyxin-Induced Nephrotoxicity by Attenuating Cellular Oxidative Stress
Authors: Azad Mohammad A. K. , Sivanesan Sivashangarie , Wang Jiping , Chen Ke , Nation Roger L. , Thompson Philip E. , Roberts Kade D. , Velkov Tony , Li Jian 
Published: October 2017

ABSTRACT

Polymyxins are a last line of defense against multidrug-resistant Gram-negative pathogens. Recent pharmacological data show that intravenous polymyxins can cause nephrotoxicity in up to 60% of patients, and the plasma concentrations of polymyxins achieved with the currently recommended dosage regimens are suboptimal in a large proportion of patients. Simply increasing the daily dose of polymyxins is not possible due to nephrotoxicity. This study aimed to examine the protective effect of methionine against polymyxin-induced nephrotoxicity. Methionine (400 mg/kg of body weight), polymyxin B (35 mg/kg), a combination of methionine (100 or 400 mg/kg) and polymyxin B, and saline were administered to mice twice daily over 3.5 days. Kidneys were collected immediately at the end of the experiment for histological examination. The effect of methionine on the pharmacokinetics of polymyxin B was investigated in rats. The attenuation of polymyxin B (0.75 mM)-induced mitochondrial superoxide production by methionine (10.0 mM) was examined in rat kidney (NRK-52E) cells. Histological results revealed that the polymyxin-induced nephrotoxicity in mice was ameliorated by methionine in a dose-dependent manner. The methionine doses were well tolerated in the mice and rats, and the pharmacokinetics of polymyxin B in rats were not affected by methionine. In the group receiving polymyxin B-methionine, the total body clearance of polymyxin B was very similar to that in the group receiving polymyxin B alone (3.71 ± 0.57 versus 3.12 ± 1.66 ml/min/kg,
P
> 0.05). A substantial attenuation of polymyxin-induced mitochondrial superoxide production in NRK-52E cells was observed following pretreatment with methionine. Our results demonstrate that coadministration of methionine significantly ameliorated polymyxin-induced nephrotoxicity and decreased mitochondrial superoxide production in renal tubular cells.
Dissemination and Characteristics of a Novel Plasmid-Encoded Carbapenem-Hydrolyzing Class D β-Lactamase, OXA-436, Found in Isolates from Four Patients at Six Different Hospitals in Denmark
Authors: Samuelsen Ørjan , Hansen Frank , Aasnæs Bettina , Hasman Henrik , Lund Bjarte Aarmo , Leiros Hanna-Kirsti S. , Lilje Berit , Janice Jessin , Jakobsen Lotte , Littauer Pia , Søes Lillian M. , Holzknecht Barbara J. , Andersen Leif P. , Stegger Marc , Andersen Paal S. , Hammerum Anette M. 
Published: October 2017

ABSTRACT

The diversity of OXA-48-like carbapenemases is continually expanding. In this study, we describe the dissemination and characteristics of a novel carbapenem-hydrolyzing class D β-lactamase (CHDL) named OXA-436. In total, six OXA-436-producing
Enterobacteriaceae
isolates, including
Enterobacter asburiae
(
n
= 3),
Citrobacter freundii
(
n
= 2), and
Klebsiella pneumoniae
(
n
= 1), were identified in four patients in the period between September 2013 and April 2015. All three species of OXA-436-producing
Enterobacteriaceae
were found in one patient. The amino acid sequence of OXA-436 showed 90.4 to 92.8% identity to the amino acid sequences of other acquired OXA-48-like variants. Expression of OXA-436 in
Escherichia coli
and kinetic analysis of purified OXA-436 revealed an activity profile similar to that of OXA-48 and OXA-181, with activity against penicillins, including temocillin; limited or no activity against extended-spectrum cephalosporins; and activity against carbapenems. The
bla
OXA-436
gene was located on a conjugative ∼314-kb IncHI2/IncHI2A plasmid belonging to plasmid multilocus sequence typing sequence type 1 in a region surrounded by chromosomal genes previously identified to be adjacent to
bla
OXA
genes in
Shewanella
spp. In conclusion, OXA-436 is a novel CHDL with functional properties similar to those of OXA-48-like CHDLs. The described geographical spread among different
Enterobacteriaceae
and the plasmid location of
bla
OXA-436
illustrate its potential for further dissemination.
In Vitro
Antibacterial Properties of Cefiderocol, a Novel Siderophore Cephalosporin, against Gram-Negative Bacteria
Authors: Ito Akinobu , Sato Takafumi , Ota Merime , Takemura Miki , Nishikawa Toru , Toba Shinsuke , Kohira Naoki , Miyagawa Satoshi , Ishibashi Naoki , Matsumoto Shuhei , Nakamura Rio , Tsuji Masakatsu , Yamano Yoshinori 
Published: October 2017

ABSTRACT

Cefiderocol (CFDC; S-649266), a novel parenteral siderophore cephalosporin conjugated with a catechol moiety, has a characteristic antibacterial spectrum with a potent activity against a broad range of aerobic Gram-negative bacterial species, including carbapenem-resistant strains of
Enterobacteriaceae
and nonfermenting bacteria such as
Pseudomonas aeruginosa
and
Acinetobacter baumannii
. Cefiderocol has affinity mainly for penicillin-binding protein 3 (PBP3) of
Enterobacteriaceae
and nonfermenting bacteria similar to that of ceftazidime. A deficiency of the iron transporter PiuA in
P. aeruginosa
or both CirA and Fiu in
Escherichia coli
caused 16-fold increases in cefiderocol MICs, suggesting that these iron transporters contribute to the permeation of cefiderocol across the outer membrane. The deficiency of OmpK35/36 in
Klebsiella pneumoniae
and the overproduction of efflux pump MexA-MexB-OprM in
P. aeruginosa
showed no significant impact on the activity of cefiderocol.