bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental Study of Aerodynamic Noise From the Trailing Edge and Leading Edge of Blades in a Coaxial-Double Shaft Fan
Authors: Madadnia Jafar , Shekeb Mustafa , Ulluwishewa Thimantha 
Published: December 2013

Proactive acoustic noise control technologies in wind turbines and blowers have in recent years been the focus of intensive research to integrate wind turbines in residential building and to address public concerns on noise pollution. However efforts to understand the mechanics has been inconclusive, mainly due to the complexity and commercial confidentiality of the topic.
The paper reports on the experimental investigation on two methods in controlling aerodynamic noise. A counter-rotating-double-row-turbine with variable gap/spacing (s) was designed, built and tested. Serrations were designed and attached on the leading edge and the trailing edge of the blades to proactively control aerodynamic noise. The model was operated in fan-mode and air velocity, shaft-revolution; electric-fan-power, acoustic noise amplitude (dB) and Centre frequency (CF in Hz) were measured for a number of spacing and serrations. Coefficients of Performance (COP), dB, CF were plotted against tip speed (TS).
It was noticed that:
• The double-shaft-fan has operated quieter than the single shaft fan especially as TS decreases. Acoustic noise (dB) dropped 20% at TS = 4m/s to less than 2% at TS = 10m/s. Efficiency and CF increased in the double-shaft fan as TS increased. Spacing variation between blade-rows had insignificant effect on the dB, Cf, and efficiency.
• Serrations on single-shaft fan have also reduced dB (up to 10%), increased efficiency and CF with more positive effects with the serrations on the leading edge than the trailing edge. Serrations are more effective at higher TS range.
• Serrations on a double-shaft fan with an optimum spacing, reduced acoustic noise (dB) only allow speeds [at TS <4m/s]. However minor improvement was noticed in efficiency or noise frequency.
Effect of Rotor-Stator Configuration in the Generation of Vortical Scales and Wake Mixing in Single Stage Axial Fans: Part II — Assessment of Vortex Sound Sources
Authors: Galdo Vega Mónica , Fernandez Oro Jesus Manuel , Argüelles Díaz Katia María , Santolaria Morros Carlos 
Published: December 2013

This second part is devoted to the identification of vortex sound sources in low-speed turbomachinery. As a starting point, the time-resolved evolution of the vortical motions associated to the wake shear layers (reported in the first part of the present study) is employed to obtain vorticity distributions in both blade-to-blade and traverse locations throughout the axial fan stage.
Following, the Powell analogy for generation of vortex sound is revisited to obtain the noise sources in the nearfield region of the fan. Both numerical and experimental databases presented previously are now post-processed to achieve a deep understanding of the aeroacoustic behavior of the vortical scales present in the flow.
A LES simulation at midspan, using a 2.5D scheme, allows an accurate description of the turn-out time of the shedding vortices, within high-density meshes in the blades and vanes passages, and a correct modeling of the dynamics of turbulence. Besides, thermal anemometry has been employed with a two-wire probe to measure the planar flow in the midspan sections of the fan. Statistical procedures and signal conditioning of velocity traces have confirmed experimentally the unsteady flow patterns devised in the numerical model.
The comparison of the rotor-stator and the stator-rotor configurations provides the influence of the wake mixing and the nucleation of turbulent spots in the distribution of the Powell source terms. Moreover, the relation between the turbomachine configuration and the generation of vortex sound can be established, including the impact of the operating conditions and the contributions of the interaction mechanisms.
Toward Direct Numerical Simulation of Aeroacoustic Field Around Airfoil Using Multi-Scale Lattice Boltzmann Method
Authors: Kusano K. , Yamada K. , Furukawa M. 
Published: December 2013

Lattice Boltzmann method (LBM) has a potential to simulate airfoil self-noise with low Mach number flow including turbulent flow and aerodynamic feedback loops. In this study, the computational techniques concerning LBM were developed toward direct numerical simulation of aeroacoustic fields with low Mach number. For applications of multi-scale phenomena such as flow and acoustic fields, multi-scale model was introduced, which enables to use locally refined grids. The grids were efficiently arranged using the Building-Cube Method (BCM) by dividing the computational domain into multiple blocks with various grid sizes. Furthermore, the zonal DNS and LES approach was adopted to suppress the numerical instability in the region of coarse grids.
The grid dependency of the results provided by the present numerical method was investigated by two-dimensional simulations of flow fields around a NACA0012 airfoil using four different grids. Furthermore, a three-dimensional simulation of flow around a NACA0018 airfoil with moderate Reynolds number was conducted. The computational results were compared and have a good agreement with the experimental ones. The present method can simulate flow around airfoil with moderate Reynolds number involving the laminar-to-turbulent transition.
Numerical Optimal Design of Impeller Back Pump-Out Vanes on Axial Thrust in Centrifugal Pumps
Authors: Hong Feng , Yuan Jianping , Heng Yanguang , Fu Yanxia , Zhou Banglun , Zong Weiwei 
Published: December 2013

Axial thrust in centrifugal pumps attracts extensive attention in order to improve the operating reliability of pumps. High axial thrust can cause rapid thrust bearing wear and subsequent pump failure or frequent overhauls. A centrifugal pump (XA65/20) was selected in this study, based on L16 (43) orthogonal array and CFD methods. The time-averaged Navier-Stokes equation was calculated for a 3D steady flow in the model pump in ANSYS CFX with the standard k-ω turbulence model and standard wall function applied. The structured meshes with different numbers were used for comparison in order to confirm that the computational results were not influenced by the mesh. Meanwhile, the effects of impeller back pump-out vane geometrical parameters, including its thickness Sk, its outlet diameter De and axial clearance δ, on the axial thrust and performances of the model centrifugal pump were analyzed. The different orthogonal schemes were obtained on the different values of Sk, De, and δ.
Finally, when the parameters of the impeller Sk, De, and δ are 5mm, 100mm, 1.5mm, respectively. The Best Efficiency Point (BEF) of 69.9% was achieved with 60.12m for the designed head and −952.133N for the minimum total axial force. The corresponding impeller with minimum total axial force was considered as the optimal scheme and manufactured for experimental test. The external characteristics by CFD have a good agreement with their experimental data, which also better verified the accuracy of the numerical method of axial thrust applied in this research.
Real-Time Multi-Color Techniques for Identification and Filtering of Burst Signals in Jet Engine Pyrometers
Authors: Wang Guanghua , Estevadeordal Jordi , Nirmalan Nirm 
Published: December 2013

A Multi-color Pyrometry (MCP) experiment was carried out on a aircraft engine to study the nature of hot particulate bursts generated from the combustor at certain engine conditions. These bursts of hot particulates lead to intermittent high-voltage signal output from the line-of-sight (LOS) pyrometer which is ultimately detected and used by the onboard Digital Engine Controller (DEC).
The investigation used a high-speed MCP system designed to detect bursts and identify their properties. Results of the radiant temperature, multi-color temperature and apparent emissivity are presented. The results indicated that the apparent emissivity calculated during the signal burst was lower than that of the blade. The root cause for the signal burst was identified as soot particles generated as by-product of combustion under certain conditions.
A digital filter technique is developed to send reliable temperature signal to DEC for robust engine control even under the engine bursting conditions. Simulink model is used to simulate the performances of the design and showed great promise for engine control.
A Nonadjuvanted Transcutaneous Tetanus Patch Is Effective in Boosting Anti-Tetanus Toxoid Immune Responses
Authors: Seid Robert C. , Reinisch Christoph , Schlegl Robert , Moehlen Michael , Meinke Andreas , Lundberg Urban 
Published: December 2013

ABSTRACTDry tetanus toxoid (TTx) patches were formulated without any adjuvant, with excipients to impart antigen stabilization and to enhance skin delivery. The booster effects of the TTx patches were assessed using a guinea pig model. The study revealed significant rises in TTx IgG titers induced by the TTx patches after a low-dose subcutaneous (s.c.) prime with TTx adsorbed to aluminum hydroxide. The TTx patch can therefore be considered an effective alternative to a subcutaneous booster.
Rapid Quantitative Serological Test for Detection of Infection with Mycobacterium leprae, the Causative Agent of Leprosy
Authors: Duthie Malcolm S. , Balagon Marivic F. , Maghanoy Armi , Orcullo Florenda M. , Cang Marjorie , Dias Ronaldo Ferreira , Collovati Marco , Reed Steven G. 
Published: December 2013

ABSTRACT
Leprosy remains an important health problem in a number of regions. Early detection of infection, followed by effective treatment, is critical to reduce disease progression. New sensitive and specific tools for early detection of infection will be a critical component of an effective leprosy elimination campaign. Diagnosis is made by recognizing clinical signs and symptoms, but few clinicians are able to confidently identify these. Simple tests to facilitate referral to leprosy experts are not widely available, and the correct diagnosis of leprosy is often delayed. In this report, we evaluate the performance of a new leprosy serological test (NDO-LID). As expected, the test readily detected clinically confirmed samples from patients with multibacillary (MB) leprosy, and the rate of positive results declined with bacterial burden. NDO-LID detected larger proportions of MB and paucibacillary (PB) leprosy than the alternative, the Standard Diagnostics leprosy test (87.0% versus 81.7% and 32.3% versus 6.5%, respectively), while also demonstrating improved specificity (97.4% versus 90.4%). Coupled with a new cell phone-based test reader platform (Smart Reader), the NDO-LID test provided consistent, objective test interpretation that could facilitate wider use in nonspecialized settings. In addition, results obtained from sera at the time of diagnosis, versus at the end of treatment, indicated that the quantifiable nature of this system can also be used to monitor treatment efficacy. Taken together, these data indicate that the NDO-LID/Smart Reader system can assist in the diagnosis and monitoring of MB leprosy and can detect a significant number of earlier-stage infections.
Comparison of Seegene Anyplex II HPV28 with the PGMY-CHUV Assay for Human Papillomavirus Genotyping
Authors: Estrade C. , Sahli R. 
Published: December 2013

ABSTRACT

The Anyplex II HPV28 (H28; Seegene) is a new semiquantitative real-time multiplex PCR assay for screening and genotyping 28 human papillomaviruses (HPV) in only 2 reaction wells. H28 was compared to the PGMY-CHUV assay (PG) with 309 archival DNA samples from cervical smears collected over 8 years in our laboratory. H28 and PG were fully concordant at the genotypic level on 228 (73.8%) out of 309 samples: 27 HPV negative and 201 HPV positive. The 201 fully concordant positive samples corresponded to single infections (
n
= 145) and to multiple infections (2 genotypes,
n
= 38; 3 to 5 genotypes,
n
= 18). The remaining 81 samples (26.2%) were either partially concordant (
n
= 64, 20.7%) or fully discordant (
n
= 17, 5.5%). While genotype-specific agreement was nearly perfect (κ = 0.877), HPV51 was significantly less well detected by H28 and the converse was observed for HPV40, -42, -54, and -68. Sequencing of PG amplicons confirmed HPV51 discordants and suggested the involvement of a possibly local HPV51 subtype. Mismatches in the PGMY09 primers to HPV68a explained most of the HPV68 discordants, confirming the specificity of H28 toward HPV68. With PG as a reference, the sensitivity and specificity of H28 were 93.4% and 99.0%, respectively. Considering H28 as a reference, the sensitivity and specificity of PG were 83.8% and 99.6%, respectively. H28 is a very sensitive and specific HPV genotyping assay suitable for research and clinical use as an adjunct to a clinically validated test. H28 semiquantitative readout ought to be evaluated for primary cervical cancer screening.
Evaluation of a Chromogenic Biplate Medium (ChromID MRSA/ChromID S. aureus) for the Simultaneous Detection of Methicillin-Resistant and Methicillin-Susceptible Staphylococcus aureus in Preoperative Screening Samples from the Anterior Nares
Authors: Mukovnikova Marina , Yusuf Erlangga , Cossey Veerle , Schuermans Annette , Saegeman Veroniek 
Published: December 2013

ABSTRACT

We evaluated the performance of the ChromID MRSA/ChromID
S. aureus
biplate for the simultaneous detection of
Staphylococcus aureus
and methicillin-resistant
S. aureus
(MRSA) in preoperative screening samples. The sensitivity and specificity were 94.2% and 93.6%, respectively, for the
S. aureus
compartment and 92.9% and 99.7% for the MRSA compartment after 48 h incubation.
Differential Responses of Disease-Resistant and Disease-Susceptible Primate Macrophages and Myeloid Dendritic Cells to Simian Hemorrhagic Fever Virus Infection
Authors: Vatter Heather A. , Brinton Margo A. 
Published: December 2013

ABSTRACT
Simian hemorrhagic fever virus (SHFV) causes a fatal hemorrhagic fever in macaques but an asymptomatic, persistent infection in baboons. To investigate factors contributing to this differential infection outcome, the targets of SHFV infection, macrophages (MΦs) and myeloid dendritic cells (mDCs), were differentiated from macaque and baboon peripheral blood monocytes and used to compare viral replication and cell responses. SHFV replicated in >90% of macaque MΦs but in only ∼10% of baboon MΦs. Although SHFV infected ∼50% of macaque and baboon mDCs, virus replication was efficient in macaque but not in baboon mDCs. Both types of macaque cultures produced higher virus yields than baboon cultures. A more efficient type I interferon response and the production of proinflammatory cytokines, including interleukin-1β (IL-1β), IL-6, IL-12/23(p40), tumor necrosis factor alpha (TNF-α), and macrophage inflammatory protein 1α (MIP-1α), in response to SHFV infection were observed in macaque but not baboon cultures, suggesting less efficient counteraction of these responses by viral proteins in macaque cells. Baboon cultures produced higher levels of IL-10 than macaque cultures both prior to and after SHFV infection. In baboon but not macaque cell cultures, SHFV infection upregulated IL-10R1, a subunit of the IL-10 receptor (IL-10R), and also SOCS3, a negative regulator of proinflammatory cytokine production. Incubation of macaque cultures with human IL-10 before and/or after SHFV infection decreased production of IL-6, IL-1β, and MIP-1α but not TNF-α, suggesting a role for IL-10 in suppressing SHFV-induced proinflammatory cytokine production in macaques.
Deletion of the Human Cytomegalovirus US17 Gene Increases the Ratio of Genomes per Infectious Unit and Alters Regulation of Immune and Endoplasmic Reticulum Stress Response Genes at Early and Late Times after Infection
Authors: Gurczynski Stephen J. , Das Subhendu , Pellett Philip E. 
Published: December 2013

ABSTRACTHuman cytomegalovirus (HCMV) employs numerous strategies to combat, subvert, or co-opt host immunity. One evolutionary strategy for this involves capture of a host gene and then its successive duplication and divergence, forming a family of genes, many of which have immunomodulatory activities. The HCMV US12 family consists of 10 tandemly arranged sequence-related genes in the unique short (US) region of the HCMV genome (US12 to US21). Each gene encodes a protein possessing seven predicted transmembrane domains, patches of sequence similarity with cellular G-protein-coupled receptors, and the Bax inhibitor 1 family of antiapoptotic proteins. We show that one member, US17, plays an important role during virion maturation. Microarray analysis of cells infected with a recombinant HCMV isolate with a US17 deletion (the ΔUS17 mutant virus) revealed blunted host innate and interferon responses at early times after infection (12 h postinfection [hpi]), a pattern opposite that previously seen in the absence of the immunomodulatory tegument protein pp65 (pUL83). Although the ΔUS17 mutant virus produced numbers of infectious particles in fibroblasts equal to the numbers produced by the parental virus, it produced >3-fold more genome-containing noninfectious viral particles and delivered increased amounts of pp65 to newly infected cells. These results suggest that US17 has evolved to control virion composition, to elicit an appropriately balanced host immune response. At later time points (96 hpi), ΔUS17 mutant-infected cells displayed aberrant expression of several host endoplasmic reticulum stress response genes and chaperones, some of which are important for the final stages of virion assembly and egress. Our results suggest that US17 modulates host pathways to enable production of virions that elicit an appropriately balanced host immune response.
Use of IRF-3 and/or IRF-7 Knockout Mice To Study Viral Pathogenesis: Lessons from a Murine Retrovirus-Induced AIDS Model
Authors: O'Connor Megan A. , Green William R. 
Published: December 2013

ABSTRACTInterferon regulatory factor (IRF) regulation of the type I interferon response has not been extensively explored in murine retroviral infections. IRF-3−/−and select IRF-3/7−/−mice were resistant to LP-BM5-induced pathogenesis. However, further analyses strongly suggested that resistance could be attributed to strain 129-specific contamination of the known retrovirus resistance geneFv1. Therefore, caution should be taken when interpreting phenotypes observed in these knockout mice, as strain 129-derived genetic polymorphisms may explain observed differences.
PB2-588I Enhances 2009 H1N1 Pandemic Influenza Virus Virulence by Increasing Viral Replication and Exacerbating PB2 Inhibition of Beta Interferon Expression
Authors: Zhao Zongzheng , Yi Chenyang , Zhao Lianzhong , Wang Shengyu , Zhou Lishan , Hu Yong , Zou Wei , Chen Huanchun , Jin Meilin 
Published: December 2013

ABSTRACT

The 2009 pandemic H1N1 influenza virus (pdm/09) is typically mildly virulent in mice. In a previous study, we identified four novel swine isolates of pdm/09 viruses that exhibited high lethality in mice. Comparing the consensus sequences of the PB2 subunit of human isolates of pdm/09 viruses with those of the four swine isolate viruses revealed one consensus mutation: T588I. In this study, we determined that 588T is an amino acid mutation conserved in pdm/09 viruses that was exceedingly rare in previous human influenza isolates. To investigate whether the PB2 with the T5581 mutation (PB2-T558I) has an effect on the increased pathogenicity, we rescued a variant containing PB2-588I (Mex_PB2-588I) in the pdm/09 virus, A/Mexico/4486/2009(H1N1), referred to as Mex_WT (where WT is wild type), and characterized the variant
in vitro
and
in vivo
. The results indicated that the mutation significantly enhanced polymerase activity in mammalian cells, and the variant exhibited increased growth properties and induced significant weight loss in a mouse model compared to the wild type. We determined that the mutation exacerbated PB2 inhibition of mitochondrial antiviral signaling protein (MAVS)-mediated beta interferon (IFN-β) expression, and PB2-588I was observed to bind to MAVS more efficiently than PB2-588T. The variant induced lower levels of host IFN-β expression than the WT strain during infection. These findings indicate that the pdm/09 influenza virus has increased pathogenicity upon the acquisition of the PB2-T588I mutation and highlight the need for the continued surveillance of the genetic variation of molecular markers in influenza viruses because of their potential effects on pathogenicity and threats to human health.
Lysis Delay and Burst Shrinkage of Coliphage T7 by Deletion of Terminator Tφ Reversed by Deletion of Early Genes
Authors: Nguyen Huong Minh , Kang Changwon 
Published: December 2013

ABSTRACT

Bacteriophage T7 terminator Tφ is a class I intrinsic terminator coding for an RNA hairpin structure immediately followed by oligo(U), which has been extensively studied in terms of its transcription termination mechanism, but little is known about its physiological or regulatory functions. In this study, using a T7 mutant phage, where a 31-bp segment of Tφ was deleted from the genome, we discovered that deletion of Tφ from T7 reduces the phage burst size but delays lysis timing, both of which are disadvantageous for the phage. The burst downsizing could directly result from Tφ deletion-caused upregulation of gene
17.5
, coding for holin, among other Tφ downstream genes, because infection of gp17.5-overproducing
Escherichia coli
by wild-type T7 phage showed similar burst downsizing. However, the lysis delay was not associated with cellular levels of holin or lysozyme or with rates of phage adsorption. Instead, when allowed to evolve spontaneously in five independent adaptation experiments, the Tφ-lacking mutant phage, after 27 or 29 passages, recovered both burst size and lysis time reproducibly by deleting early genes
0.5
,
0.6
, and
0.7
of class I, among other mutations. Deletion of genes
0.5
to
0.7
from the Tφ-lacking mutant phage decreased expression of several Tφ downstream genes to levels similar to that of the wild-type phage. Accordingly, phage T7 lysis timing is associated with cellular levels of Tφ downstream gene products. This suggests the involvement of unknown factor(s) besides the known lysis proteins, lysozyme and holin, and that Tφ plays a role of optimizing burst size and lysis time during T7 infection.

IMPORTANCE
Bacteriophages are bacterium-infecting viruses. After producing numerous progenies inside bacteria, phages lyse bacteria using their lysis protein(s) to get out and start a new infection cycle. Normally, lysis is tightly controlled to ensure phage progenies are maximally produced and released at an optimal time. Here, we have discovered that phage T7, besides employing its known lysis proteins, additionally uses its transcription terminator Tφ to guarantee the optimal lysis of the
E. coli
host. Tφ, positioned in the middle of the T7 genome, must be inactivated at least partially to allow for transcription-driven translocation of T7 DNA into hosts and expression of Tφ downstream but promoter-lacking genes. What role is played by Tφ before inactivation? Without Tφ, not only was lysis time delayed but also the number of progenies was reduced in this study. Furthermore, T7 can overcome Tφ deletion by further deleting some genes, highlighting that a phage has multiple strategies for optimizing lysis.