bluuebunny/crossref_metadata_2025 huggingface dataset:
Cancer Treatment Facilities: Using Design Thinking to Examine Anxiety and the Patient Experience
Authors: Michalec Sarah , Dickinson Joan I. , Sullivan Kathleen , Machac Kristin , Cline Holly
Published: October 2018

Worldwide, 14 million people were diagnosed with cancer, and 8.8 million victims of cancer died in 2015 (Cancer, 2017). There is no doubt that cancer is a traumatic experience. Using design–thinking strategies, the purpose of this qualitative study was to examine if the built environment in cancer care facilities influences anxiety in patients and to generate patient–driven solutions to reduce stress. Due to its human–centered and codesign emphasis, design thinking is uniquely qualified to explore cancer treatment facility design. Yet, little research using a design–thinking approach examines how the built environment influences stress among patients in an oncology unit. Eight stakeholders ( n = 8), including cancer survivors, patients, caregivers, and staff, participated in three design–thinking workshops generating ideas for oncology units. In Workshop One, participants identified issues that caused anxiety through journaling and experience diagramming, including amount of travel within the facility, small uncomfortable waiting rooms, smells, and institutional spaces. Using prioritizing strategies, participants concluded with, “How can we optimize patients’ time and movement within a facility?” This question informed subsequent workshops where participants brainstormed and prototyped ideas. The final solution addressed patient time and movement through the creation of individualized Patient Treatment Pods (PTP) that provided control, privacy, comfort, and minimal travel within oncology units. Participants clustered the PTPs around a restroom, patient lounge, nurse's station, and nutrition. Utilizing participants’ personal experiences along with design thinking led to a prototype that creates a cancer treatment facility that may better suit patient needs while potentially reducing anxiety.
How do neonatal units within the Australian and New Zealand Neonatal Network manage ex‐preterm infants with severe chronic lung disease still requiring major respiratory support at term?
Authors: Battin Malcolm R , McKinlay Christopher JD
Published: October 2018

Aim

The aim was to survey the Australian and New Zealand Neonatal Network (ANZNN) member units regarding current services and management guidelines for the ex‐premature infant with severe chronic lung disease (CLD) still requiring significant respiratory support at term.

Methods

A 16‐question survey was sent to clinical directors of all Level 3 units in Australia and New Zealand via the network. Reminder emails were sent, as required, to prompt a satisfactory response rate.

Results

Survey responses were received from 26 of the 29 (90%) ANZNN Level 3 units. At 37 weeks' corrected gestation, over 90% of the units provide ongoing respiratory support in the neonatal intensive care unit (NICU). However, by 50 weeks, ongoing care is provided in several settings, including NICU, high dependency unit (HDU)/paediatric intensive care unit or respiratory wards. The majority (76%) of units arrange transfer on an ad hoc basis, but six units (24%) have set criteria for transfer based on gestation, workload and respiratory requirement. Three units declared a maximum age in NICU (44, 46 or 48 weeks). A variety of approaches were used to identify infants who were likely to require transfer, and 78% of units had a staff member assigned to assist transition. Three units stated that they had a home ventilation programme suitable for these infants. No unit supplied a guideline on tracheostomy or specific respiratory management post‐term.

Conclusion

Despite a significant number of babies requiring ongoing support for severe CLD, the location of the service appears very variable, and there is a lack of specific written guidelines.
What is the state of complexity science in medical education research?
Authors: Cristancho Sayra , Field Emily , Lingard Lorelei
Published: October 2018

Context

‘Complexity’ is fast becoming a ‘god term’ in medical education, but little is known about how scholars in the field apply complexity science to the exploration of education phenomena. Complexity science presents both opportunities and challenges to those wishing to adopt its approaches in their research, and debates about its application in the field have emerged. However, these debates have tended towards a reductive characterisation of complexity versus simplicity. We argue that a more productive discussion centres on the multiplicity of complexity orientations, with their diverse disciplinary roots, concepts and terminologies. We discuss this multiplicity and use it to explore how medical education researchers have taken up complexity science in prominent journals in the field.

Methods

We synthesised the health sciences and medical education literature based on 46 papers published in the last 18 years (2000–2017) to describe the patterns of use of complexity science in medical education and to consider the consequences of those patterns for our ability to advance scholarly conversations about ‘complex’ phenomena in our field.

Results

We identified four patterns in the use of complexity science in medical education research. Firstly, complexity science is described in a variety of ways. Secondly, multiple approaches to complexity are used in combination in single papers. Thirdly, the type of complexity science used tends to be left implicit. Fourthly, the complexity orientation used is much more commonly located using secondary source citation rather than primary source citation.

Conclusions

The presence of these four patterns begs the question: Do medical education scholars understand that there are multiple legitimate orientations to complexity science, deriving from distinct disciplinary origins, drawing on different metaphors and serving distinct purposes? If we do not understand this, a cascade of potential consequences awaits. We may assume that complexity science is singular in that there is only one way to do it. This assumption may cause us to perceive our way as the ‘right’ way and to disregard other approaches as illegitimate. However, this perception of illegitimacy may limit our ability to enter into productive dialogue about our complexity science‐inspired research.
Factors underlying suboptimal diagnostic performance in physicians under time pressure
Authors: ALQahtani Dalal A , Rotgans Jerome I , Mamede Silvia , Mahzari Moeber M , Al‐Ghamdi Ghassan A , Schmidt Henk G
Published: October 2018

Context

Time pressure has been implicated in the suboptimal diagnostic performance of doctors and in increases in diagnostic errors. However, the reasons underlying these effects are not clear. The aim of this study was to investigate the influence of time pressure on physicians’ diagnostic accuracy and to explore the mediating effects of perceived stress (emotional pathway) and number of plausible diagnostic hypotheses (cognitive pathway) on the proposed relationship.

Methods

We conducted a randomised controlled experiment. A total of 75 senior internal medicine residents completed eight written clinical cases under conditions with (n = 40) or without (n = 35) time pressure. They were then asked to: (i) rate the overall stress experienced, and (ii) write down any alternative hypotheses they had thought of when diagnosing the cases. In a post hoc analysis, a mediation path analysis was performed to test the causal relationships between time pressure, perceived stress and number of alternative diagnoses.

Results

Participants who were under time pressure spent less time diagnosing the cases (85.54 seconds versus 181.81 seconds; p< 0.001) and had a lower mean diagnostic accuracy score (0.44 versus 0.53; p = 0.01). In addition, they reported more stress (5.80 versus 4.69; p = 0.01) and generated fewer plausible tentative hypotheses (0.37 versus 0.51; p = 0.01). Two path coefficients were found to be statistically significant; the first path coefficient referred to the relationship between time pressure and perceived stress (standardised β = 0.25, p = 0.029), and the second negative path coefficient referred to the relationship between time pressure and number of plausible alternative hypotheses (standardised β = −0.32, p< 0.01).

Conclusions

Time pressure adversely influences physicians’ diagnostic accuracy by increasing their stress response and reducing the number of plausible hypotheses as mediators.
Quantitative phosphoproteomic analysis reveals common regulatory mechanisms between effector‐ and PAMP‐triggered immunity in plants
Authors: Kadota Yasuhiro , Liebrand Thomas W. H. , Goto Yukihisa , Sklenar Jan , Derbyshire Paul , Menke Frank L. H. , Torres Miguel‐Angel , Molina Antonio , Zipfel Cyril , Coaker Gitta , Shirasu Ken
Published: October 2018

Plant immunity consists of two arms: pathogen‐associated molecular pattern (PAMP)‐triggered immunity (PTI), induced by surface‐localized receptors, and effector‐triggered immunity (ETI), induced by intracellular receptors. Despite the little structural similarity, both receptor types activate similar responses with different dynamics.

To better understand phosphorylation events during ETI, we employed a phosphoproteomic screen using an inducible expression system of the bacterial effector avrRpt2 in Arabidopsis thaliana, and identified 109 differentially phosphorylated residues of membrane‐associated proteins on activation of the intracellular RPS2 receptor.

Interestingly, several RPS2‐regulated phosphosites overlap with sites that are regulated during PTI, suggesting that these phosphosites may be convergent points of both signaling arms. Moreover, some of these sites are residues of important defense components, including the NADPH oxidase RBOHD, ABC‐transporter PEN3, calcium‐ATPase ACA8, noncanonical Gα protein XLG2 and H+‐ATPases. In particular, we found that S343 and S347 of RBOHD are common phosphorylation targets during PTI and ETI. Our mutational analyses showed that these sites are required for the production of reactive oxygen species during both PTI and ETI, and immunity against avirulent bacteria and a virulent necrotrophic fungus.

We provide, for the first time, large‐scale phosphoproteomic data of ETI, thereby suggesting crucial roles of common phosphosites in plant immunity.
Comparison of bleach, acetic acid, and other topical anti‐infective treatments in pediatric atopic dermatitis: A retrospective cohort study on antibiotic exposure
Authors: Asch Sarah , Vork Diana L. , Joseph Josiane , Major‐Elechi Brittny , Tollefson Megha M.
Published: October 2018

Background/Objectives

Skin infection is common in atopic dermatitis (AD), often necessitating treatment with systemic antibiotics. Topical adjunctive therapies such as dilute bleach baths are increasingly recommended, and topical dilute acetic acid (AA) has not been widely studied. The objective of this study was to evaluate whether various topical anti‐infective bathing recommendations were associated with decreased systemic antibiotic exposure in pediatric AD, as well as evaluate topical anti‐infective recommendations over time within our institution.

Methods

Clinical data were extracted from charts of pediatric patients from 1/1/2000 to 12/31/2005 and 1/1/2009 to 12/31/2014 who visited outpatient dermatology clinics at Mayo Clinic, Rochester, a tertiary referral center. Recommendations for topical anti‐infectives (dilute AA, dilute bleach, other, or none) at any time after patient had clinically proven or suspected AD superinfection were recorded as exposures to topical anti‐infective. Primary outcome was the number of systemic antibiotic courses in a 1‐year period.

Results

Of 1111 patients with AD, 753 met inclusion criteria (303 in 2000‐2005; 450 in 2009‐2014). Of these, 351 (46.6%) had culture‐proven or clinically suspected superinfection. Topical anti‐infective recommendations increased between the time periods (23.3% to 79.2%; P < 0.001) and number of courses of systemic antibiotics decreased (1.9 per year vs 1.5 per year, P = 0.010). Number of systemic antibiotic courses did not differ between those who received bathing recommendations and those who did not, nor between different anti‐infective groups (P = 0.398).

Conclusions

Practice behaviors have changed, and topical anti‐infectives are now commonly recommended. Neither dilute AA nor bleach baths were associated with fewer subsequent exposures to systemic antibiotics in the treatment of pediatric AD.
Detection of bacterial contamination in platelet concentrates from Brazilian donors by molecular amplification of the ribosomal 16S gene
Authors: Viana J. D. , Ferreira S. C. , Matana S. R. , Rossi F. , Patel P. , Garson J. A. , Rocha V. , Tedder R. , Mendrone‐Júnior A. , Levi J. E.
Published: October 2018

Objective

The aim of our work was to establish a semi‐automated high‐throughput DNA amplification method for the universal screening of bacteria in platelet concentrates (PCs).

Background

Among cases of transfusion transmission of infectious agents, bacterial contamination ranks first in the number of events, morbidity and mortality. Transmission occurs mainly by transfused PCs. Automated culture is adopted by some blood banks for screening of bacterial contamination, but this procedure is expensive and has a relatively long turnaround time.

Methods

PCs were spiked with suspensions of five different bacterial species in a final concentration of 1 and 10 colony‐forming units (CFU) per millilitre. After incubation, the presence of bacteria was investigated by real‐time polymerase chain reaction (PCR) and by the Enhanced Bacterial Detection System (eBDS, Pall) assay as a reference method. Real‐time PCR amplification was performed with a set of universal primers and probes targeting the 16S rRNA gene. Co‐amplification of human mitochondrial DNA served as an internal control.

Results

Using the real‐time PCR method, it was possible to detect the presence of all bacterial species tested with an initial concentration of 10 CFU mL−1 24 h after contamination, except for Staphylococcus hominis. The PCR assay also detected, at 24 h, the presence of Serratia marcescens and Enterobacter cloacae with an initial concentration of 1 CFU mL−1.

Conclusions

The real‐time PCR assay may be a reliable alternative to conventional culture methods in the screening of bacterial contamination of PCs, enabling bacterial detection even with a low initial concentration of microorganisms.
Lung lobe torsion in dogs: 52 cases (2005–2017)
Authors: Park Karen M. , Grimes Janet A. , Wallace Mandy L. , Sterman Allyson A. , Thieman Mankin Kelley M. , Campbell Bonnie G. , Flannery Erin E. , Milovancev Milan , Mathews Kyle G. , Schmiedt Chad W.
Published: October 2018

Objective

To report outcomes and risk factors for mortality in dogs that underwent surgical management of lung lobe torsion.

Study design

Retrospective case series from 5 veterinary teaching hospitals (2005–2017).

Animals

Fifty dogs with 52 instances of lung lobe torsion.

Methods

Data collected from medical records included signalment, clinical findings, results of clinicopathologic testing and diagnostic imaging, surgical treatment, lung lobe affected, intraoperative and postoperative complications, histopathologic and microbiologic findings, and outcome. Follow‐up was obtained from medical records and telephone contact with primary care veterinarians.

Results

Fifty‐two instances of lung lobe torsion were identified in 50 dogs, with a median follow‐up of 453 days (range, 0–3075). Forty‐six (92%) dogs survived to discharge. Dogs with concurrent torsion of the right cranial and middle lung lobes were less likely to survive (2/4) than those with torsion of the left cranial lung lobe (22/22). No other risk factors for mortality prior to hospital discharge were identified. Overall median survival time after hospital discharge was 1369 days. Four dogs had >1 episode of lung lobe torsion.

Conclusion

The percentage of dogs surviving to discharge after surgical treatment of lung lobe torsion was higher than previously reported. The short‐ and long‐term prognosis was excellent with surgical treatment of lung lobe torsion.

Clinical significance

Surgery should be recommended when lung lobe torsion is suspected because of the high survival to discharge rate and excellent long‐term prognosis.
Faba bean as green manure for field weed control in maize
Authors: Álvarez‐Iglesias L , Puig C G , Revilla P , Reigosa M J , Pedrol N
Published: October 2018

Field observations on crop rotations with maize in temperate areas suggest that faba bean (Vicia faba) could exert some weed control when used as a green manure. To test this hypothesis, two glasshouse pot experiments and two field experiments were conducted on the weeding effects over time of faba bean incorporated into the soil. In the pots, faba bean concentrations of 1% and 2% of soil dry weight reduced the germination, root and shoot elongation and aerial biomass of Echinochloa crus galli and Amaranthus retroflexus by ca. 70% when the seeds were sown at the time of faba bean incorporation. These inhibitory effects declined with the delay in sowing. From ca. 21 days after incorporation, fertilising effects became evident in both the maize and the two weeds. In the two field experiments, on land with a history of maize growing in which faba bean biomasses of 6700 and 12 100 kg ha−1 were soil‐incorporated, residue‐mediated reductions of the density and biomass of naturally occurring dominant dicotyledon (A. retroflexus, Chenopodium album and Solanum nigrum) and monocotyledon weeds (Digitaria sanguinalis and Cyperus rotundus) were observed. At emergence, mean differences with respect to control plots ranged from −14.8% to −69.8% for density and from −46.9 to −78.5% for biomass. Impacts were visible at the flowering time, and still statistically significant for some dicotyledons, leading to mean differences of total weed biomass up to −67.2% compared with control plots. Our results indicate that faba bean has potential as green manure for weed control in maize cropping systems.
TEMPORAL RAINFALL DISAGGREGATION BY A SIMPLE RANDOM CASCADE MODEL
Authors: Saad Siti Mariam , Jemain Abdul Aziz , Ismail Noriszura
Published: October 2018

This study evaluates the utility and suitability of a simple discrete multiplicative random cascade model for temporal rainfall disaggregation. Two of a simple random cascade model, namely log-Poisson and log-Normal  models are applied to simulate hourly rainfall from daily rainfall at seven rain gauge stations in Peninsular Malaysia. The cascade models are evaluated based on the capability to simulate data that preserve three important properties of observed rainfall: rainfall variability, intermittency and extreme events. The results show that both cascade models are able to simulate reasonably well the commonly used statistical measures for rainfall variability (e.g. mean and standard deviation) of hourly rainfall. With respect to rainfall intermittency, even though both models are underestimated, the observed dry proportion, log-Normal  model is likely to simulate number of dry spells better than log-Poisson model. In terms of rainfall extremes, it is demonstrated that log-Poisson and log-Normal  models gave a satisfactory performance for most of the studied stations herein, except for Dungun and Kuala Krai stations, which both located in the east part of Peninsula.
NOVEL PALM OIL BASED POLYOLS WITH AMINE FUNCTIONALITY SYNTHESIS VIA RING OPENING REACTION OF EPOXIDIZED PALM OIL
Authors: Soloi Sabrina , Abdul Majid Rohah , Rahmat Abdul Razak
Published: October 2018

In polymer chemistry, polyol usually used as starting materials for polyurethane (PU) production in which upon reacted with isocyanate will affect the physical and chemical properties of the obtained PU. Polyols that are mostly derived from petrochemical resources are facing issues such as depletion of petroleum sources as well as the increasing in market price. Ring opening reaction (ROR) of epoxidized palm oil (EPO) had been carried out using isopropanolamine (IPA) to impart polyol with amine functionality. The effect of reaction time on the opening of oxirane ring was investigated. FTIR spectra showed that the oxirane ring opening of EPO can occur at 6 hours reaction time, corresponding to the deacreasing intensity of  oxirane COO twin band at 824-830 cm-1. The OH value of the amine- functionalized-polyol was calculated at around 240-253 mg KOH/g. By prolonging the reaction time the OH value has slightly reduced. Mass spectroscopy analysis revealed that the polyol has a molecular weight in the range of oligo-polyols (400 – 500 Da).
BIOSYNTHESIS OF SILVER NANOPARTICLES FROM MARINE POLYCHAETE DIOPATRA CLAPAREDII GRUBE, 1878
Authors: Hussain Nur Shaheera , Harun Noor Aniza , Mohd Radzi Mohd Naim Fadhli , Idris Izwandy , Wan Ismail Wan Iryani
Published: October 2018

Silver nanoparticles (AgNPs) offer a broad range of high commercial value applications. However, current techniques to synthesize AgNPs using chemical and physical approaches are toxic to the environment and not cost-effective in the long-term. Therefore, utilization of green biological synthesis technique to produce AgNPs is one of the solutions. In this study, marine polychaete Diopatra claparedii was used to investigate its potential in synthesizing AgNPs. Specimens were collected from tidal flats adjacent to the mangrove forest in the west coast of Peninsular Malaysia and divided into two groups: freshly prepared (acclimatized in aquaria) and frozen (kept in the freezer) samples. Samples from both groups were cut, finely pulverized, filtrated, and mixed with silver nitrate (AgNO3) at room temperature. Colour changes were recorded after 24 hours, 2 weeks, and 8 weeks of incubation. Formation of AgNPs was quantified using UV-Vis spectroscopy analysis, where surface Plasmon resonance (SPR) peaks were observed in the range of 400–440 nm, confirming the formation of the AgNPs. Subsequently, the synthesized nanoparticles were validated using scanning electron microscope. AgNPs showed weak antibacterial activity because of aggregation. Further studies are required to confirm the findings.
COMPARISON BETWEEN HYBRID QUANTILE REGRESSION NEURAL NETWORK AND AUTOREGRESSIVE INTEGRATED MOVING AVERAGE WITH EXOGENOUS VARIABLE FOR FORECASTING OF CURRENCY INFLOW AND OUTFLOW IN BANK INDONESIA
Authors: Prastyo Dedy Dwi , Suhartono Suhartono , Puka Agnes Ona Bliti , Lee Muhammad Hisyam
Published: October 2018

Some problems arise in time series analysis are nonlinearity and heteroscedasticity. Methods that can be used to analyze such problems are neural network and quantile regression. There are a lot of studies and developments on both methods, but the study that focuses on the performances of combination of these two methods applied in real case are still limited. Therefore, this study performed a comparison between hybrid Quantile Regression Neural Network (QRNN) and Autoregressive Integrated Moving Average with Exogenous Variable (ARIMAX). Both methods were employed to model the currency inflow and outflow from Bank Indonesia in Nusa Tenggara Timur province. Based on the empirical result, the hybrid QRNN method provided better forecasting for currency outflow whereas the ARIMAX resulted in better forecasting for the inflow.
SYNTHESIS AND CHARACTERIZATION OF BENZOHYDROXAMIC ACID METAL COMPLEXES AND THEIR CYTOTOXICITY STUDY
Authors: Hassan Latifah Robbaniyyah , Ramasamy Kalavathy , Lim Siong Meng , Bahron Hadariah , Mohd Tajuddin Amalina
Published: October 2018

Hydroxamic acids (RCONHOH) are versatile compounds that constitute a significant biological importance. The syntheses, physico-chemical and characterization of benzohydroxamic acid (BHA) and its metal complexes (VO(IV), Cr(III) and Ni(II)) are reported herein. The metal complexes were synthesized via condensation reaction of BHA and metal salts in 2:1 molar ratio using ethanol as reaction medium. The compounds were characterized by elemental analysis, spectral (infrared, UV-Vis, 1H and 13C NMR,), TGA, magnetic susceptibility as well as molar conductance. The spectral study analysis reveals that all complexes coordinated to the metal via oxygen atoms (O,O) in bidentate manner to form octahedral for [Cr(BHA2).2H2O]H2O, tetrahedral for [Ni(BHA)2] and square pyramidal geometry for [VO(BHA)2]. The molar conductance values suggested that all complexes were non-electrolytes. A cytotoxicity study against HCT116 displayed that VO(IV) has better IC50 values than the parent ligand, BHA but not considered as potent anticancer agents.
IMPROVEMENT IN MACHINING PERFORMANCE OF INCONEL 718 WITH SOLID LUBRICANTS
Authors: Kumar Sunil , Singh Dilbag , Singh Kalsi Nirmal
Published: October 2018

From the last decade, the use of high corrosion resistance, high strength superalloys (mostly Ni- or Ti-based) at elevated temperature have significantly increased in aerospace or transport industry. Such materials are tremendously difficult to cut, develop a high temperature and deteriorate the quality of the components leading to tool wear. In place of using the cutting fluid, strict environmental limit develops new cutting methods or techniques for enhancing the tool life. This study demonstrates the performance of solid lubricants (hexagonal boron nitride and graphite) on surface quality. Tool geometry and cutting variables were selected for machining Inconel 718 with TiAlN-coated carbide inserts. The comparison has been conducted between solid lubricant assistant machining and dry machining. The studies demonstrate that the performance of solid lubricants is better than dry machining. There is 10% to 18% reduction in surface roughness with solid lubricants as compared to dry machining.
Application of Graphene in Coatings: A Survey
Authors: Guo Hongfei , Zhang Ru , Zhao Zengqi , Zou Min , Chen Xiangyue , He Zhihui , Qu Ting , Li Congdong , Huang Guoquan
Published: October 2018

Graphene has been applied and demonstrates its excellent functions in various functional coatings by virtue of its excellent thermal, mechanical and electrical properties. This paper mainly introduces the application status and effect of graphene in conductive coating, anticorrosive coating, flame retardant coating, thermal conductive coating and high-strength coating. Finally, the application prospect of graphene in the field of coating is prospected.
Low Pressure Phase Transformations During High-Speed, High-Temperature Scratching of Silicon
Authors: Alreja Chirag , Subbiah Sathyan
Published: October 2018

Higher temperature assisted processing of silicon, such as heat-assisted diamond turning, is often being considered to improve surface integrity. At higher temperatures and under mechanical loading and unloading, caused by a moving tool, silicon deforms plastically often in association with occurrence of phase transformations. This paper investigates such phase transformations in rotational scratching of single crystal (100) p-type silicon with a conical diamond tool under various furnace-controlled temperatures ranging from room temperature (RT) to 500 °C and at scratching speeds comparable to that used in the diamond turning process (1 m/s). Phase transformation study, using Raman spectroscopy, at various crystal orientations, shows differences in phases formed at various temperatures when compared to that reported in indentation. The tendency to form phases is compared between scratched and diamond turned surfaces at RT, and also with that reported at low scratching speeds in the literature. Analytical indenting-based pressure calculations show that at higher temperatures, phase transformations can happen in silicon at significantly lower pressures. Analysis of depths of the scratched groove indicates that at temperatures beyond a certain threshold, plastic deformation and significant elastic recovery may be causing shallow grooves. Abrasive wear coefficients are thus seen to decrease with the increase in temperatures. This study is expected to help tune heat-assisted diamond turning conditions to improve surface formation.
Cooling Effectiveness for a Shaped Film Cooling Hole at a Range of Compound Angles
Authors: Haydt Shane , Lynch Stephen
Published: October 2018

Shaped film cooling holes are a well-established cooling technique used in gas turbines to keep component metal temperatures in an acceptable range. One of the goals of film cooling is to reduce the driving temperature for convection at the wall, the success of which is generally represented by the film cooling adiabatic effectiveness. However, the introduction of a film cooling jet-in-crossflow, especially if it is oriented at a compound angle, can augment the convective heat transfer coefficient and dominate the flowfield. This work aims to understand the effect that a compound angle has on the flowfield and adiabatic effectiveness of a shaped film cooling hole. Five orientations of the public 7–7–7 shaped film cooling hole were tested, from a streamwise-oriented hole (0 deg compound angle) to a 60 deg compound angle hole, in increments of 15 deg. Additionally, two pitchwise spacings of P/D = 3 and 6 were tested to examine the effect of hole-to-hole interaction. All cases were tested at a density ratio of 1.2 and blowing ratios ranging from 1.0 to 4.0. The experimental results show that increasing compound angle leads to increased lateral spread of coolant and enables higher laterally averaged effectiveness at high-blowing ratios. A smaller pitchwise spacing leads to more complete coverage of the endwall and has higher laterally averaged effectiveness even when normalized by coverage ratio, suggesting that hole to hole interaction is important for compound angled holes. Steady Reynolds-averaged Navier–Stokes computational fluid dynamics (CFD) was not able to capture the exact effectiveness levels, but did predict many of the observed trends. The lateral motion of the coolant jet was also quantified, both from the experimental data and the CFD prediction, and as expected, holes with a higher compound angle and higher blowing ratio have greater lateral motion, which generally also promotes hole-to-hole interaction.
A Unified Methodology to Evaluate the Radiated Noise Due to Turbulent Boundary Layer Flows
Authors: Morilhat Sylvain , Chedevergne François , Simon Frank
Published: October 2018

For vibro-acoustic applications, a turbulent wall pressure (TWP) fluctuations model was derived. The model is based on the resolution of Poisson's equation. The pressure is characterized in time and space through its spectrum in the frequency wave-number domain. The developed model follows trends commonly observed using Corcos model in a large frequency range but also shows new behaviors for low and high frequencies. The radiated noise due to TWP fluctuations is then computed in accordance with the form of the TWP spectrum. A specific computational methodology is proposed to perform the calculation without introducing limiting hypothesis on the radiated impedance.
Gauss Map Based Curved Origami Discretization
Authors: Zhang Liping , Pang Guibing , Bai Lu , Ji Tian
Published: October 2018

This paper addresses the problem of discretizing the curved developable surfaces that are satisfying the equivalent surface curvature change discretizations. Solving basic folding units occurs in such tasks as simulating the behavior of Gauss mapping. The Gauss spherical curves of different developable surfaces are setup under the Gauss map. Gauss map is utilized to investigate the normal curvature change of the curved surface. In this way, spatial curved surfaces are mapped to spherical curves. Each point on the spherical curve represents a normal direction of a ruling line on the curved surface. This leads to the curvature discretization of curved surface being transferred to the normal direction discretization of spherical curves. These developable curved surfaces are then discretized into planar patches to acquire the geometric properties of curved folding such as fold angle, folding direction, folding shape, foldability, and geometric constraints of adjacent ruling lines. It acts as a connection of curved and straight folding knowledge. The approach is illustrated in the context of the Gauss map strategy and the utility of the technique is demonstrated with the proposed principles of Gauss spherical curves. It is applicable to any generic developable surfaces.
Ferrohydrodynamic Capillary Convection
Authors: Arias Francisco J. , De Las Heras Salvador A.
Published: October 2018

In this work, consideration is given to capillary convection on ferrofluids from the concentration gradient induced when a nonhomogeneous magnetic field is applied. It is known that mass transfer along an interface between two fluids can appear due to a gradient of the surface tension in the so-called Marangoni effect (or Gibbs–Marangoni effect). Because the surface tension is both thermal and concentration dependent, Marangoni convection can be induced by either a thermal or a concentration gradient, where in the former case, it is generally referred as thermocapillary convection. Now, it has been theoretically and experimentally demonstrated that a ferrofluid under the action of a non-homogeneous magnetic field can induce a concentration gradient of suspended magnetic nanoparticles, and also the effect of Fe3O4 nanoparticles on the surface tension has been measured. Therefore, by deductive reasoning and taking into account the above mentioned facts, it is permissible to infer ferrohydrodynamic capillary convection on magnetic fluids under the presence of a magnetic gradient field. Utilizing a simplified physical model, the phenomenon was investigated and it was found that ferrohydrodynamic-Marangoni convection could be induced with particle size in the range up to 10 nm, which is the range of magnetic fluids to escape magnetic agglomeration.
Assessment of the Tribological Contact Between Sliding Surfaces Via an Entropy Approach
Authors: Deeva Vera , Slobodyan Stepan
Published: October 2018

The interaction observed between two surfaces in contact with one another is part of a number of physical processes, such as wear. In this paper, we present a numerical study of the asperities between two surfaces in contact with each other. The real contact area between two surfaces varies due to the multiple roughness scales caused by the stochastic nature of asperities. In our research, we employ a tribological system comprising two partitions: C1 is the contact set (CS), where the two surfaces are in direct contact with each other, and C2 is the noncontact set, where the two surfaces are not in contact with each other. Here, we have developed a new numerical model to describe the CS using ε-entropy to prove the existence of a minimum value for entropy in sliding contact scenarios. In this system, the lower and upper bounds of entropy are determined through the Kolmogorov approach using the aforementioned model. Using this model, we conclude that the ε-entropy value is bound between ln 2 and 2·ln 2 for a tribological system comprising two partitions. Additionally, we conclude that a correlation between the stochastic tribological contact behavior and the rate of entropy change is the key parameter in thermal nonequilibrium scenarios.
Numerical and Experimental Investigation on an Effusion-Cooled Lean Burn Aeronautical Combustor: Aerothermal Field and Emissions
Authors: Mazzei L. , Puggelli S. , Bertini D. , Andreini A. , Facchini B. , Vitale I. , Santoriello A.
Published: October 2018

Lean burn combustion is increasing its popularity in the aeronautical framework due to its potential in reducing drastically pollutant emissions (NOx and soot in particular). Its implementation, however, involves significant issues related to the increased amount of air dedicated to the combustion process, demanding the redesign of injection and cooling systems. Also, the conditions at the combustor exit are a concern, as high turbulence, residual swirl, and the impossibility to adjust the temperature profile with dilution holes determine a harsher environment for nozzle guide vanes. This work describes the final stages of the design of an aeronautical effusion-cooled lean burn combustor. Full annular tests were carried out to measure temperature profiles and emissions (CO and NOx) at the combustor exit. Different operating conditions of the ICAO cycle were tested, considering Idle, Cruise, Approach, and Take-off. Scale-adaptive simulations with the flamelet generated manifold (FGM) combustion model were performed to extend the validation of the employed computational fluid dynamics (CFD) methodology and to reproduce the experimental data in terms of radial temperature distribution factor (RTDF)/overall temperature distribution factor (OTDF) profiles as well as emission indexes (EIs). The satisfactory agreement paved the way to an exploitation of the methodology to provide a deeper understanding of the flow physics within the combustion chamber, highlighting the impact of the different operating conditions on flame, spray evolution, and pollutant formation.
Shape Control for the Elastica Through Load Optimization
Authors: Nayak Arvind , Handral Poornakanta , Rangarajan Ramsharan
Published: October 2018

Flexible elastic beams can function as dexterous manipulators at multiple length-scales and in various niche applications. As a step toward achieving controlled manipulation with flexible structures, we introduce the problem of approximating desired quasi-static deformations of a flexible beam, modeled as an elastica, by optimizing the loads applied. We presume the loads to be concentrated, with the number and nature of their application prescribed based on design considerations and operational constraints. For each desired deformation, we pose the problem of computing the requisite set of loads to mimic the target shape as one of optimal approximations. In the process, we introduce a novel generalization of the forward problem by considering the inclinations of the loads applied to be functionals of the solution. This turns out to be especially beneficial when analyzing tendon-driven manipulators. We demonstrate the shape control realizable through load optimization using a diverse set of experiments.
An Investigation of Ultrasonic Transducer Loading on a Workpiece
Authors: Zennaro Marco , Haig Alex , O’Boy Dan J. , Walsh Stephen J.
Published: October 2018

Arrays of dry-coupled thickness-shear transducers are often employed in the guided wave sector to inspect pipelines and plate-like structure. The dry coupling permits to dismiss any coupling material between the transducer and the waveguide, but as a drawback a preload must be applied on the transducers to guarantee an effective coupling between the two surfaces. Although the influence of the preload on the natural frequencies is studied in the literature, the frequency response function of a transducer relating the input voltage to the displacement output is not present in the literature. Moreover, the distribution of force on the backing mass and the effect of the preload on the uniformity of vibration of the transducers are still missing. A natural frequency analysis and a forced analysis are then computed numerically with finite element analysis to quantify the influence of the preload on a thickness-shear transducer. Furthermore, these results are compared with experimental results obtained with a Laser Vibrometer. It is then shown how the geometrical layout of the transducer coupled with the preload influences the vibration of the transducer.
Overview of Structural-Acoustic Modal Analysis Under Random Loading
Authors: Sung Shung H. , Nefske Donald J.
Published: October 2018

Random excitations can result from various types of non-deterministic loads such as wind loads, terrain loads, and other types of white noise loads. In this paper, an overview is presented of the modal method to obtain the random response of a coupled structural-acoustic system subjected to random excitations. When the structural system is coupled with an enclosed cavity, the structural-acoustic frequency response functions (FRFs) can be obtained using the uncoupled structural modes and the uncoupled acoustic modes, with structural-acoustic coupling as well as modal damping included in the formulation. The random response of the coupled structural-acoustic system is then obtained by summation of the structural-acoustic FRFs with the applied auto- and cross-spectral random loadings at the excitation locations. The theoretical formulation of the coupled structural-acoustic system is described. An example of a rectangular cavity coupled with flexible panels exposed to external random white noise load is presented. The methodology is then applied to an automotive vehicle travelling over a randomly rough road to predict the interior sound pressure response in the vehicle.
Analyzing the Soundscape of an Urban Park: A Case of Semmozhi Poonga
Authors: Chitra Banu , Jain Minakshi , Ahmed Faiz
Published: October 2018

This paper investigates the soundscape of a designed urban park in Chennai. Acoustic measurements and subjective evaluations of the soundscape were conducted at various locations in the identified case. The park was divided into nine zones for conducting the primary survey, such as parking area, entrance court, tree court, children’s play, herbal garden, butterfly garden, open-air theatre, duck pond, and mound. Fourteen different sounds were mapped based on the pilot survey that affected the users. Totally thirty responses were collected from each zone. The observed sounds include traffic sound, honking of vehicles, screaming of people & children, chuckling of children, the chirping of birds, ringing of the mobile phone, crowd talking, rustling of leaves, wind sound, play equipment sound, splashing of water, flowing of water, and machine sound. From the subjective survey, it is found that the individual soundscape preference collected from each space have no correlation with the overall soundscape experience of the same space. Based on the measurement data, the individual and the overall experience on soundscape perception were examined.
CFD Based Lock-in Modeling of Cavity-Pipe Line Systems
Authors: Bagwell Ted G. , Cody Kristin L.
Published: October 2018

Flow over shallow cavities is a noise concern due to the possibility of flow tone lock-in with acoustic resonators. The principal aim of this work is to understand the factors that contribute to the onset of lock-in using Computational Fluid Dynamics (CFD) models.

CFD models of shallow cavity lock-in to longitudinal acoustic resonators are developed and validated against existing test data from Lehigh University. All simulations are performed using AcuSolve™. A key technical contribution is the development of admittance inflow and impedance outflow boundary conditions to model the effects of the pipe resonator. The general trends predicted by the CFD models agree with the test data. In particular, the resonator response at the strong interaction point is well represented.
Analysis of Acoustic Radiation Characteristics of an Infinitely Long Half-Filled Cylindrical Shell
Authors: Zhang Shuai , Li Tianyun , Zhu Xiang , Guo Wenjie
Published: October 2018

The acoustic radiation analysis of a fully-submerged infinitely long half-filled cylindrical shell coupling with fluid field is a typical acoustic-structure problem in the infinite domain, the solution of which is currently mainly based on numerical method. The analytic or semi-analytical method is indispensable for the numerical method and the mechanism to reveal the acoustic-structure coupling characteristics. In this paper, an analytic solution is presented that can calculate the acoustic radiation of infinitely long half-filled cylindrical shell. The displacement of the shell, the fluid load and the excitation force are expressed as the combination of trigonometric series and Fourier series, and displacements of the other two directions are removed by orthogonalizing, only the radial displacement is retained. The control equation of the fluid-structure interaction can be obtained from the relationship between the amplitude of fluid load and the amplitude of radial displacement which can be established by orthogonalizing the continuous conditions of the fluid-structure coupled contact surface and the free surface boundary condition. Solving the control equation, the vibration and acoustic radiation of the coupling system can be determined. Compared with the finite element software Comsol, the results of forced vibration and underwater radiated noise show that the presented method is accurate and reliable. A new way to solve acoustic-vibration problem with partial coupling of elastic structure and sound field is provided in this study.
Optimized reactive silencers with narrow side-branch tubes
Authors: Červenka Milan , Bednařík Michal
Published: October 2018

This paper presents a theoretical study of the sound propagation in a waveguide loaded by an array of flush-mounted narrow side-branch tubes, forming a simple low-frequency reactive silencer. The individual tube-lengths and the distances between the adjacent tubes are optimized in order to maximize the minimum transmission loss over a given frequency range. The transmission properties of the silencer are calculated using the transfer matrix method, heuristic evolutionary approach is employed for the determination of the optimal parameters. The numerical results are validated against the finite element method simulation. A comprehensive parametric study is performed to demonstrate the optimized silencer performance as a function of the number of side-branch tubes, and the frequency range. It is shown that for the given frequency range, the minimum transmission loss of the optimized silencer increases linearly with the number of the side-branch tubes.
Amentoflavone Ameliorates Streptococcus suis-Induced Infection
In Vitro
and
In Vivo
Authors: Shen Xue , Niu Xiaodi , Li Gen , Deng Xuming , Wang Jianfeng
Published: October 2018

The widespread use of antibiotics in therapy and in the prevention of
Streptococcus suis
infection in the swine industry raises concerns for the emergence of a resistant strain. The use of antivirulence agents has potential benefits, mainly because of the reduced selective pressure for the development of bacterial resistance. In this study, we found that amentoflavone is an effective agent against
S. suis
serotype 2 (SS2) infection both
in vitro
and
in vivo
. Our results demonstrated that amentoflavone is a promising anti-infective therapeutic for
S. suis
infections, due to its antivirulence and anti-inflammatory effects without antibacterial activity, with fewer side effects than conventional antibacterial agents.
Sequencing and Analysis of the Genome of the Filamentous Fungus
Penicillium verrucosum
BFE808, Which Produces the Mycotoxins Citrinin and Ochratoxin
Authors: Schmidt-Heydt Markus , Stoll Dominic , Geisen Rolf
Published: October 2018

Penicillium verrucosum
is a filamentous ascomycete that occurs worldwide. Various cereals and the products thereof are the main habitats of this fungal species, where it produces the mycotoxins ochratoxin and citrinin.
Draft Genome Sequence of Xylella fastidiosa subsp.
fastidiosa
Strain IVIA5235, Isolated from Prunus avium in Mallorca Island, Spain
Authors: Landa Blanca B. , Velasco-Amo María P. , Marco-Noales Ester , Olmo Diego , López María M. , Navarro Inmaculada , Monterde Adela , Barbé Silvia , Montes-Borrego Miguel , Román-Écija Miguel , Saponari Maria , Giampetruzzi Annalisa
Published: October 2018

We report the complete annotated genome sequence of the plant-pathogenic bacterium
Xylella fastidiosa
subsp.
fastidiosa
strain IVIA5235.