Extensive SEM work was carried out on deep etched specimens to reveal the evolution of graphite shape in Fe–C–Si alloys of industrial composition during early solidification and at room temperature. ...The samples had various magnesium and titanium levels designed to produce graphite morphologies ranging from coarse lamellar to interdendritic lamellar to mixed compacted – spheroidal. The present findings were then integrated in previous knowledge to produce an understanding of the crystallization of lamellar, compacted and spheroidal graphite.
It was demonstrated that most forms of graphite grow radially from a common center, most of the time as foliated dendrites (see Figure). The basic building blocks of the graphite aggregates are hexagonal faceted graphite platelets with nanometer height and micrometer width. During solidification, thickening of the platelets occurs through growth of additional graphene layers nucleated at the ledges of the graphite prism. In the magnesium-free irons that graphite platelets assemble into foliated crystals and dendrites, forming graphite plates that grow along the a-axis. In the magnesium-modified melts the graphite platelets stack along the c-axis, producing clusters with random orientation. The clusters are then assembled into quasi-cylindrical shapes connected to more or less curved walls to form tadpole graphite, compacted graphite, or chunky graphite. If enough magnesium is added, conical sectors made of platelets stacked in the c-direction grow from the same nucleus. The conical sectors may occupy the whole volume of the sphere forming a graphite spheroid, or only part of it like in chunky graphite. The large number of cavities observed between the platelets is consistent with growth of foliated dendrites.
Display omitted
During their recycling, cellulosic fibres suffer irreversible damage caused by repeated wetting and drying cycles, beating stages and bleaching reactions. This damage decreases the mechanical ...properties of the paper prepared from recycled pulp. Soft beating of the pulp is a simple way to partially recover the original mechanical properties, but it is limited by the high degradation of fibres, fines generation and decrease in drainage rate that recycled fibres already present. The present research studies the use of nanofibrillated cellulose (CNF) as an alternative to mechanical beating to improve the strength properties of paper produced from a deinked recycled pulp obtained by disintegration and flotation of a mixture of old newspapers and magazines. Different percentages of CNF were added to this mixture with a retention aid. A fraction of the same pulp without CNF was also beaten at different intensities in a PFI mill. Morphological properties of both beaten and CNF-reinforced pulp suspensions, as well as structural and mechanical properties of handsheets made thereof, were analysed and their results compared. Paper containing 1.5 % of CNF presented a higher tensile strength and stiffness than paper from beaten pulp with similar freeness and water retention values. A higher amount of CNF further improved the mechanical properties, up to double the tensile index, which opens new possibilities of use for recycled paper.
Abstract
We employ the corrected Gaia Early Data Release 3 photometric data and spectroscopic data from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) DR7 to assemble a sample ...of approximately 0.25 million FGK dwarf photometric standard stars for the 12 J-PLUS filters using the stellar color regression (SCR) method. We then independently validate the J-PLUS DR3 photometry and uncover significant systematic errors: up to 15 mmag in the results from the stellar locus method and up to 10 mmag primarily caused by magnitude-, color-, and extinction-dependent errors of the Gaia XP spectra as revealed by the Gaia BP/RP (XP) synthetic photometry (XPSP) method. We have also further developed the XPSP method using the corrected Gaia XP spectra by B. Huang et al. and applied it to the J-PLUS DR3 photometry. This resulted in an agreement of 1–5 mmag with the SCR method and a twofold improvement in the J-PLUS zero-point precision. Finally, the zero-point calibration for around 91% of the tiles within the LAMOST observation footprint is determined through the SCR method, with the remaining approximately 9% of the tiles outside this footprint relying on the improved XPSP method. The recalibrated J-PLUS DR3 photometric data establish a solid data foundation for conducting research that depends on high-precision photometric calibration.
Summary
Digitaria sanguinalis is a troublesome annual weed that causes important yield losses in different crops. Despite this, there is scarce information about different aspects of its biology ...under field conditions. New knowledge about the establishment process of this species will be of paramount importance in order to maximise the effectiveness of weed management. The aims of this paper were to evaluate the effect of stubble found on the surface on seed dormancy levels through the season, the effects of stubble and soyabean crop canopy on seedling emergence and to determine the field emergence pattern as a consequence of seed dormancy level at dispersal time. Seeds on the soil surface, which showed a high dormancy level at the beginning of autumn, were released from dormancy by low winter temperatures and germinated during spring as temperatures rose, showing a transient surface seedbank. Seeds covered by stubbles had delayed the emergence in the field due to lower alternating temperatures perceived by the surface seedbank. On the other hand, the presence of a soyabean crop and stubble together reduced the number of seedlings. Seeds with a high dormancy level at dispersal time showed a delayed emergence in the next season when compared with seeds with a lower dormancy level. However, the final number of seedlings was similar. Both stubble on surface and crop canopy are useful factors to lessen and delay the seedling emergence allowing the design of weed management strategies in order to diminish the population levels of this species.
Nurses in primary health care (PHC) have multiple responsibilities but must often work with limited resources. The study's aim was to estimate burnout levels among PHC nurses. A Quantitative, ...observational, cross-sectional, multicentre study of 338 nurses working in PHC in the Andalusian Public Health Service (Spain) is presented. A total of 40.24% of the nurses studied had high levels of burnout. The dimensions of emotional exhaustion and depersonalisation were significantly associated with anxiety, depression, neuroticism, on-call duty and seniority-profession and inversely related to agreeableness. In addition, depersonalisation was significantly associated with gender, and emotional exhaustion correlated inversely with age. Personal achievement was inversely associated with anxiety and depression and positively correlated with agreeableness, extraversion and responsibility. There is a high prevalence of burnout among nurses in PHC. Those most likely to suffer burnout syndrome are relatively young, suffer from anxiety and depression and present high scores for neuroticism and low ones for agreeableness, responsibility and extraversion.
This paper describes the implementation and evaluation of an accessory designed and manufactured to be adapted to a 3D printer to allow the in situ and continuous mixing of powder and liquid feeds. ...In particular, the capacity of this accessory to correctly mix a dysphagia-oriented commercial powder thickener with several conventional fluids (i.e. water, juice, and milk) was studied. Target thickener concentrations were defined in order to achieve mixtures with viscosities corresponding to the textures established by the National Dysphagia Diet Task Force (NDD)—nectar-like, honey-like, and spoon-thick—for thickened fluids. Both the accuracy of the solid content and the rheological response of the obtained mixtures were evaluated. Although fluctuations were observed in the concentrations of the mixtures obtained by continuous mixing with respect to the target values, the viscosities obtained were within the limits established for each of the desired textures. The thickened fluids processed using the 3D printing mixing accessory showed viscosities very similar to their hand-mixed counterparts and a higher degree of structuration, especially when printed at low mass flow rates, as well as a lower amount of entrapped air. This method of preparation allows the production of thickened fluids with more appealing shapes and colours for the long-term dysphagia management, improving the quality of life of patients with dysphagia, and promoting treatment compliance.
Display omitted
•Development of a solid/liquid mixing device (MIX3D) for 3D printers.•MIX3D was applied to the preparation of dysphagia-oriented thickened fluids.•Thickener content was set to obtain nectar-like, honey-like and spoon-thick textures.•Rheological properties of mixtures are comparable to those of hand-prepared fluids.•Water, orange juice and skimmed milk have been successfully thickened with MIX3D.
We study the behaviour of the dynamical and stellar mass inside the effective radius (r
e) of early-type galaxies (ETGs). We use several samples of ETGs – ranging from 19 000 to 98 000 objects – from ...the ninth data release of the Sloan Digital Sky Survey. We consider Newtonian dynamics, different light profiles and different initial mass functions (IMF) to calculate the dynamical and stellar mass. We assume that any difference between these two masses is due to dark matter and/or a non-universal IMF. The main results for galaxies in the redshift range 0.0024 < z < 0.3500 and in the dynamical mass range 9.5 < log(M) < 12.5 are: (i) a significant part of the intrinsic dispersion of the distribution of dynamical versus stellar mass is due to redshift; (ii) the difference between dynamical and stellar mass increases as a function of dynamical mass and decreases as a function of redshift; (iii) the difference between dynamical and stellar mass goes from approximately 0 to 70 per cent of the dynamical mass depending on mass and redshift; (iv) these differences could be due to dark matter or a non-universal IMF or a combination of both; (v) the amount of dark matter inside ETGs would be equal to or less than the difference between dynamical and stellar mass depending on the impact of the IMF on the stellar mass estimation; (vi) the previous results go in the same direction of some results of the Fundamental Plane (FP) found in the literature in the sense that they could be interpreted as an increase of dark matter along the FP and a dependence of the FP on redshift.
In the last years, there has been an interest in development of simulators to reproduce the mechanical properties of the human digestive system. Particularly, there have been some approaches in the ...development of esophagus simulators. Such simulators intend to replicate the peristaltic wave conditions, but the reported experiments are related to indirect measurements in which the use of a fluid is not reported. In this work, an X-ray technique for visualizing the flow of bolus through an artificial esophageal simulator (AES) is proposed. For that purpose, particles of barium sulfate were thoroughly mixed with baby food, in order to create a suspension used as bolus. Barium sulfate particles used in the present work are insoluble in water with non-regular forms, a size distribution from 20 to 80 nm, and a specific surface area ranging from 10 to 50 m
2
/g. The advantage of using barium sulfate is its high absorption of X-rays, which allows obtaining a good contrast in radiographies, so that the transport of the bolus along the esophagus simulator can be easily tracked. The results revealed the appearance of secondary flows on the wave sides, which displace as the wave contracts. This was verified with the flow fields, in which it was observed that the bolus flows mainly along the central part of the wave and a small volume tends to retract. This confirms that the flow is extensional as the bolus is stretched and compressed during the peristalsis.
Graphical abstract
PDF
![[Translated article] Use of...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0001-7310/small "[Translated article] Use of Antihistamines During Omalizumab Therapy in Chronic Urticaria in the Routine Clinical Practice. A 48-Patient Observational Trial")
