bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analytical Solution for Froude–Krylov Force of Triangulated Geometry in Linear Waves
Authors: Liu Rex Kuan-Shuo , Lin Tsung-Yueh 
Published: December 2020

Abstract
For wave exciting load on offshore structures, Froude–Kyrlov (FK) force is easier to evaluate than diffracting force. But current nonlinear FK models suffer low computational speed. Conventionally, FK force is calculated by performing Gaussian quadrature (GQ) on each surface mesh, and the choice of the mesh size is important in order to resolve wave characteristics both in the propagation and depth directions. Therefore, either by limiting the size of a surface mesh under one-tenth of the wavelength or increasing the order of GQ, numerical errors can be minimized. For the purpose of relieving the above restriction, the analytical integration of the dynamic pressure field in the time domain over a triangular mesh is derived to avoid the mesh-dependent errors and to improve computational efficiency. It will be shown that the solution of integration obtained in time domain can be cast in the frequency domain under linearized free surface conditions. Validation includes the analytical solution to a cuboid at head sea and numerical solutions to a catamaran by commercial software. The results show excellent agreement for general wave conditions and prominence at very high-frequency range. In terms of computational efficiency, we compared the execution time against GQ with different orders and showed the analytical method is significantly faster. The limitation of this method is in very long waves or for degenerated panels, which are specifically addressed by line integration.
Coupling Fractal Model for Fretting Wear on Rough Contact Surfaces
Authors: Wang Yi , Gang Liang , Liu Shuo , Cui Yi 
Published: December 2020

AbstractIn this paper, a fretting damage model based on fractal theory is proposed. The Weierstrass–Mandelbrot function of fractal theory is used to represent the rough contact surface, and a corresponding contact parameter analysis method is also established. Based on neural network algorithm, the values of fractal parameters are fitted, and the fitting accuracy has been greatly improved compared with traditional methods. According to the fractal parameters of the actual surface, the fretting wear process of the rough contact surface is analyzed based on theory of adhesive and three-body abrasive wear. A generic program for the analysis of three-dimensional fretting wear problems is also proposed. Compared with material tests, the prediction error of the fretting wear simulation model is 13.4% for wear depth and 16.7% and 3.9% for width and length of wear scar in stable wear stage. The prediction results show that the model can be applied to the prediction of the actual three-dimensional fretting wear model.
Numerical Study on the Interaction of Transverse and Longitudinal Roughness on Elastohydrodynamic Lubrication Contact Surfaces With Different Thermal Conductivities and Elastic Moduli
Authors: Kaneta Motohiro , Matsuda Kenji , Wang Jing , Cui Jinlei , Yang Peiran , Nishikawa Hiroshi , Krupka Ivan , Hart Martin 
Published: December 2020

Abstract
The interaction and surface features between point contact surfaces composed of longitudinal roughness with infinite or finite length and transverse roughness were discussed based on a transient non-Newtonian thermal elastohydrodynamic lubrication (EHL) model. Each surface shape is greatly affected by the difference in elastic moduli, thermal conductivities, and velocities of both contact surfaces. There is a large difference in pressure behavior when the transverse roughness is in contact with the longitudinal roughness with finite length and when it is in contact with the longitudinal roughness with infinite length. In the contact between surfaces with infinitely long longitudinal and transverse roughness, the friction coefficient is lower when the surface with longitudinal roughness has a low thermal conductivity than when it has a high thermal conductivity. Furthermore, the pressure fluctuation is larger when the transverse roughness surface has a high thermal conductivity than when it has a low thermal conductivity.
Windmilling Characteristics of a Contra-Rotating Fan
Authors: Manas M. P. , Karmakar Arghya , Pradeep A. M. 
Published: December 2020

Abstract
In the present experimental study, a low aspect ratio, low hub-tip ratio contra-rotating axial fan is investigated to understand its performance under windmilling conditions. Two configurations are tested; in the first configuration (event A), the front rotor of the contra-rotating fan is powered and the rear rotor is allowed to windmill; in the second configuration (event B), the rear rotor of the contra-rotating fan is powered and the front rotor is allowed to windmill. The spanwise distribution of the loading coefficient and the flow angles at different streamwise positions reveal the details of the flow development across the rotors. Though the average total pressure drops across the windmilling rotor for both the events, a small spanwise region behaves as a fan or a stirrer. Thus, a “neutral radius” on the windmilling rotor is identified for both events A and B. The neutral radius appears close to the tip for event A and it appears close to the hub for event B. Thus, the span regions close to the tip behave as a fan for event A and the span regions close to the hub behave as a stirrer for event B. It is also observed that the neutral radius shifts to a lower span location as the flow coefficient reduces. Thus, the flow coefficient is a significant parameter that decides the position of the neutral radius. Further, the unsteady pressure measurements recorded at the casing capture the fundamental phenomena during the stall inception. The paper thus relates the similarities and unveils the contrasting features of the windmilling events A and B. In summary, this paper discusses the performance, flow physics, and stall inception characteristics of a contra-rotating axial fan under windmilling conditions.
Numerical Study of Thermal Properties of a Silica Aerogel Material
Authors: Maazoun Amal , Mezghani Abderrazak , Moussa Ali Ben 
Published: December 2020

AbstractSilica Aerogel is material with a special structure consisting of interconnected solid particles of SiO2 forming the skeleton that enclose nanopores filled with confined air and occupying more than 90% of the volume. It is characterized by a thermal conductivity that can reach lower values than any other material. Our aim was to explain the causes of the super-insulation of this material with the use of a calculating method of conductive heat transfer flux in an aerogel structure and determine the equivalent thermal conductivity. For this purpose, numerical specific software was developed to generate random structure of silica aerogel with predefined concentration of solid particles and properties of both skeleton and confined air. Calculation of the conductivity at any point in the confined gas domain shows variable values as a function of the pore size and the location of the point in the pore. A new developed numerical method was used to calculate the equivalent thermal conductivity of the whole structure. Concentration of solid particles has proved not to be the only parameter in which determine the thermal conductivity of silica aerogel and the influence of tortuosity has been demonstrated. A correlation linking thermal conductivity to both concentration of solid particles and tortuosity of the material was suggested.
A Method for the Determination of Antimicrobial Properties of Treated Fabrics
Authors: Quinn Herbert 
Published: December 2020

A method has been presented for evaluating the effectiveness of fabrics treated with antimicrobial agents to resist growth of contaminating organisms. The method consists of direct inoculation of the fabric with suitable test organisms and the subsequent enumeration of growing colonies which develop when the fabric is implanted in a nutrient medium.
The method is sensitive, versatile, easy to perform, highly reproducible, and realistically evaluates the practical effectiveness of residual antimicrobial agents on fabrics.
Data are given which demonstrate the sensitivity of the method to small differences in antimicrobial concentrations. The versatility of the method is shown by the variety of antimicrobial agents and organisms which have been utilized. Both bacteriostatic and bactericidal activity can be evaluated.
Sampling Techniques for the Enumeration of Microorganisms in the Diverticulum of the Anterior Thoracic Air Sac of Chickens
Authors: Tarver F. R. , May K. N. , Boyd F. M. 
Published: December 2020

The swab, excise, flush, and agar microbial sampling techniques were applied randomly to the air sac cavities of 130 healthy broiler chickens of 56 to 70 days of age when slaughtered. Samples were obtained from both nonscalded and scalded chickens. The scalded chickens were immersed in the scald water (49 ± 0.5 C) for 120 sec immediately after severing the blood vessels from the outside at the base of the lower mandible. From these data, a selection was made of a sampling technique for the air sac cavity which would yield reproducible counts with the least amount of variation.
The flush and swab technique did not differ significantly and had less variation than did the excise and agar techniques. Even though no significant differences existed between the flush and swab techniques, the flush technique might be preferred because of the closed system present during the time in which the sample is obtained. The method of expressing microbial concentration in the air sac cavity might best be as “per air sac.”
Harvesting of Algae by Froth Flotation
Authors: Levin Gilbert V. , Clendenning John R. , Gibor Ahron , Bogar Frederick D. 
Published: December 2020

A highly efficient froth flotation procedure has been developed for harvesting algae from dilute suspensions. The method does not depend upon the addition of flotants. Harvesting is carried out in a long column containing the feed solution which is aerated from below. A stable column of foam is produced and harvested from a side arm near the top of the column.
The cell concentration of the harvest is a function of pH, aeration rate, aerator porosity, feed concentration, and height of foam in the harvesting column. The economic aspects of this process seem favorable for mass harvesting of algae for food or other purposes.
The Microflora of Frozen Passionfruit Nectar Base
Authors: Aea Raymond T. F. , Bushnell O. A. 
Published: December 2020

A considerable and varied microflora is introduced into passionfruit nectar base under present methods of production. In spite of the great acidity of the nectar base (pH range: 2.8 to 3.2), the high sucrose concentration (approximately 50%), and storage at -20 C, remnants of the microflora persist for a year or longer. During storage, however, there is a steady and gradual decrease, until after about 18 months the microflora is near to extinction. Sample regression lines show straight-line slopes for this diminution in numbers.
A battery of nine media was used to grow a representative aerobic flora. Purified cultures of isolates were identified to genera. Yeasts were the most numerous organisms in all samples, followed by molds, bacteria, and streptomycetes. The bacteria were the first group to disappear during storage. No fecal streptococci or gram-negative bacilli were found in any samples.
Modified Two-Phase System for Partition of
Bacillus macerans
Spores
Authors: Sacks L. E. 
Published: December 2020

An aqueous two-phase system made with polyethylene glycol (PEG) 1000 and potassium phosphate gives much higher recovery of
Bacillus macerans
spores in the upper phase (PEG rich) than does a similar system utilizing PEG 4000. The upper phase completely rejects vegetative cells, which collect at the interface. The system may be useful in purifying spores of other species. Scanning electron micrographs of
B. macerans
spores cleaned in this system show no obvious attached sporangial fragments. The micrographs show that the ridged coat may form polygonal structures at the poles, as previously observed in
Bacillus polymyxa
spores.
Actinomyces naeslundii
as an Agent of Human Actinomycosis
Authors: Coleman R. Marie , Georg Lucille K. , Rozzell Allen R. 
Published: December 2020

The repeated isolation of
Actinomyces naeslundii
from clinical materials associated with disease led to a comparison of isolates from the normal mouth with isolates from pathological clinical materials not from the mouth area. No important differences were observed between the isolates from these two sources. A human case of empyema of the gall bladder, apparently due to
A. naeslundii,
is described.
Rapid Diagnosis of Bacteremia
Authors: Finegold Sydney M. , White Maurice L. , Ziment Irwin , Winn William R. 
Published: December 2020

Early appropriate treatment of bacteremia is important in minimizing morbidity and mortality. Standard blood culture methods are not optimal since several days are often required for recovery and identification of organisms which may be present in the blood. The use of a membrane filter technique allows one to grow any organisms present in blood much more rapidly than by broth or pour plate culture. Furthermore, growth is in the form of typical colonies on the surface of solid media, and a series of rapid diagnostic tests may be used to provide speedy identification. Use of membrane filters also facilitates removal by washing of normal antibacterial factors and antimicrobial drugs which may be present in blood. Although the filter technique yielded the most rapid growth, broth culture and whole blood pour plates yielded more positive cultures and use of all three systems was necessary for maximal recovery of organisms in blood cultures. Data on quantitative aspects of bacteremia in the antimicrobial era are also presented. The number of low level bacteremias (10 colonies/ml or less) is surprisingly high. This is particularly true for gram-negative bacilli; antimicrobial therapy at the time of culture undoubtedly influenced these results greatly. Finally, suggestions are given for a much simpler and more efficient membrance filter blood culture technique.
Scanning Electron and Phase-Contrast Microscopy of Bacterial Spores
Authors: Bulla L. A. , Julian G. St. , Rhodes R. A. , Hesseltine C. W. 
Published: December 2020

The three-dimensional immages of free and intrasporangial spores produced by scanning electron microscopy show surface structures not visible by phase-contrast microscopy. Although fine surface detail is not elucidated by scanning electron microscopy, this technique does afford a definitive picture of the general shape of spores. Spores of
Bacillus popilliae, B. lentimorbus, B. thuringiensis, B. alvei, B. cereus,
and
Sarcina ureae
have varying patterns of surface ridge formation, whereas spores of
B. larvae, B. subtilis,
and
B. licheniformis
have relatively smooth surfaces.
Use of Mitomycin C to Distinguish
Brucella abortus
Field Strains from the Vaccinal
Brucella abortus
Strain 19
Authors: Myers Donald M. , Dobosch Dora 
Published: December 2020

Field strains of
Brucella abortus
were resistant to mitomycin C, whereas strain 19 was sensitive; therefore, the antibiotic was used to distinguish
B. abortus
strain 19 from other strains.
Time-Temperature Effects on Salmonellae and Staphylococci in Foods
Authors: Angelotti Robert , Foter Milton J. , Lewis Keith H. 
Published: December 2020

Thermal death time studies were conducted at 5 F intervals from 130 to 150 F with strains of salmonellae and enterotoxigenic staphylococci. Heat-resistant
Salmonella senftenberg
strain 775W,
Staphylococcus aureus
strains 196E and Ms149, and non-heat-resistant
Salmonella manhattan
were studied in custard, chicken à la king, and ham salad.

The
F
140
values (minutes of exposure at 140 F required to effect 100% destruction) were as follows:
S. senftenberg
775W in custard 78, and chicken à la king 81.5;
S. manhattan
in custard 19, and chicken à la king 3.1;
S. aureus
196E in custard 59, and chicken à la king 47;
S. aureus
Ms149 in custard 53, and chicken à la king 40.

The end points of survival-kill at all the test temperatures for both salmonellae and staphylococci in ham salad were considerably less than for the other foods studied.

D
140
values (minutes of exposure at 140 F required to effect a 90% reduction in numbers) were also calculated from the data and presented.

Values for

z
F

and

z
D

(slope of the thermal-death-time and decimal-reduction-time curves) are also presented and discussed in relation to type of food, organism, and temperature.

These data indicate that heating perishable foods of the type studied to 150 F and holding every particle of food at this temperature for at least 12 min reduces 10 million or less salmonellae or staphylococci per gram to nondetectable levels.
The same degree of destruction is achieved in similarly contaminated foods when held at 140 F for 78 to 83 min.
On the basis of the calculation procedures employed, it is estimated that 45-min exposure at 140 F would be necessary to reduce 1,000 organisms per gram to nondetectable levels.
Preparation of Purified Polysaccharides from
Rhizobium
Authors: Davis R. J. , Clapp C. E. 
Published: December 2020

A method is described for the preparation of purified polysaccharides from strains of
Rhizobium
in quantities large enough so that with an exhaustive purification scheme enough product is recovered for various characterization purposes. When steps in the purification process are eliminated, much larger amounts of crude gum are obtained.

Organisms were grown in liquid medium and the crude gum was precipitated along with the bacterial cells by a quaternary ammonium complexing agent. This precipitate was dissolved in salt solution, reprecipitated with ethanol or ethanol-acetone mixtures several times, followed by pressure filtration with membrane filters.
The same procedure should be applicable to commercial scale production in large fermentors if a use for the gum could be shown. The method also should be suitable for other organisms with similar growth habits.
Occurrence of Enterococci: Bud, Blossom, and Soil Studies
Authors: Mundt J. Orvin 
Published: December 2020

The occurrence of enterococci (group D streptococci) on buds and flowers of plants and in soils has been studied. They were recovered from 27.5% of the flowers of seven species of plants, and from 6.8% of the buds of the same plants. They were recovered from 34% of the flowers of nonagricultural plants, from 32.2% of the flowers of ten species of agricultural dicotyledonous plants, and from 10.4% of the flowers of five species of grasses and cereals. The enterococci were invariably present or invariably absent from all samples taken from very few species. They occurred in small numbers on enclosed tassels and silks of corn of 22 of 60 samples, and in greater numbers on 90% or more of these after their floral parts had emerged. Interposition of a mechanical barrier reduced the incidence of recovery from flowers. The occurrence in soil, generally at a low level of population, may be correlated with occurrence on the plant growing on the soil or with nearby enterococcal-bearing plants.
It is concluded that enterococci may be regarded as temporary residents on plants, capable of limited reproduction, and that they are disseminated among plants by the action of insects and wind, and spread to the ground by these agencies, gravity, and rain.
Low assets and financial stressors associated with higher depression during COVID-19 in a nationally representative sample of US adults
Authors: Ettman Catherine K , Abdalla Salma M , Cohen Gregory H , Sampson Laura , Vivier Patrick M , Galea Sandro 
Published: December 2020

BackgroundCOVID-19 and related containment policies have caused or heightened financial stressors for many in the USA. We assessed the relation between assets, financial stressors and probable depression during the COVID-19 pandemic.MethodsBetween 31 March 2020 and 13 April 2020, we surveyed a probability-based, nationally representative sample of US adults ages 18 and older using the COVID-19 and Life stressors Impact on Mental Health and Well-being survey (n=1441). We calculated the prevalence of probable depression using the Patient Health Questionnaire-9 (cut-off ≥10) and exposure to financial stressors by financial, physical and social assets categories (household income, household savings, home ownership, educational attainment and marital status). We estimated adjusted ORs and predicted probabilities of probable depression across assets categories and COVID-19 financial stressor exposure groups.ResultsWe found that (1) 40% of US adults experienced COVID-19-related financial stressors during this time period; (2) low assets (OR: 3.0, 95% CI 2.1 to 4.2) and COVID-19 financial stressor exposure (OR: 2.8, 95% CI 2.1 to 3.9) were each associated with higher odds of probable depression; and (3) among persons with low assets and high COVID-19 financial stressors, 42.7% had probable depression; and among persons with high assets and low COVID-19 financial stressors, 11.1% had probable depression. Persons with high assets and high COVID-19 financial stressors had a similar prevalence of probable depression (33.5%) as persons with low assets and low COVID-19 financial stressors (33.5%). The more assets a person had, the lower the level of probable depression.ConclusionPopulations with low assets are bearing a greater burden of mental illness during the COVID-19 pandemic.
Leading the spread and adoption of innovation at scale: an Academic Health Science Network’s perspective
Authors: Walker Andrew , Dale Catherine , Curran Natasha , Boaz Annette , Hurley Michael V 
Published: December 2020

BackgroundThere is virtually no limit to the number of innovations being developed, tested and piloted at any one time to improve the quality and safety of care. The perennial problem is spreading innovations that are proven to be effective on a smaller scale or under controlled conditions. Much of the literature on spread refers to the important role played by external agencies in supporting the spread of innovations.Academic Health Science Networks and the spread of innovationExternal agencies can provide additional capacity and capabilities to adopter organisations, such as technical expertise, resources and tools to assist with operational issues. In England, the National Health Service (NHS) established 15 Academic Health Science Networks (AHSNs) to help accelerate the spread and adoption of innovation in healthcare. However, formal clinical-academic networks (such as AHSNs) themselves will not deliver positive, tangible outcomes on the ground (ie, evidence-based innovations embedded at scale across a system). This begs the question of how do AHSNs practically go about achieving this change successfully? We provide an AHSN’s perspective on how we conceptualise and undertake our work in leading implementation of innovation at scale.An AHSN"s perspectiveOur approach is a collaborative process of widening understanding of the innovation and its implementation. At its core, the implementation and spread of innovation into practice is a collective social process. Healthcare comprises complex adaptive systems, where contexts need to be negotiated for implementation to be successful. As AHSNs, we aim to lead this negotiation through facilitating knowledge exchange and production across the system to mobilise the resources and collective action necessary for achieving spread.