533 research outputs found
Psychological possibilities and functions of modern information technologies as the means for students’ self-realization in university training
The objective of this study was to define the leading functions of information and communication technologies that stimulate the manifestation of various forms of students’ self-realization in the educational process of the university. The socio-cultural approach that enables to reveal the role of information technologies as means for transferring the experience of culture and realizing students’ essential forces is the leading approach to study this issu
Synthesis and characterisation of nanocrystalline ZrN PVD coatings on AISI 430 stainless steel
The nanocrystalline films of zirconium nitride have been synthesized using ion-plasma vacuum-arc deposition technique in combination with high-frequency discharge (RF) on AISI 430 stainless steel at 150oC. Structure examinations X-ray fluorescent analysis (XRF), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) with microanalysis (EDS), and transmission electron microscopy (TEM), nanoidentation method – were performed to study phase and chemical composition, surface morphology, microstructure and nanohardness of coatings. The developed technology provided low-temperature coatings synthesis, minimized discharge breakdown decreasing formation of macroparticles (MPs) and allowed to deposit ZrN coatings with hardness variation 26.6…31.5 GPa. It was revealed that ZrN single-phase coatings of cubic modification with finecrystalline grains of 20 nm in size were formed
Some improvement opportunities of regenerative processes of rabbit cornea after experimental alkaline burns
Department of Anatomy, I. Ya. Gorbachevskiy State Medical University of Ternopol, UkraineBackground: Nowadays peptide bioregulators, stimulating repair processes, accelerating the substitution of necrotizing tissue with fibrous tissue and
facilitating active access of young low-differentiated cellular elements between the corneal plates, reprezent a promising way of treating damaged cornea
including its chemical burns. A well-known fact is that biological tissues exhibit a similar activity not only due to alive cells but also homogenates and
extracts from them.
Material and methods: The experiments have been performed on 24 rabbits. Each animal has been subject to a corneal burn with alkali (10%
NaOH). Time of exposition for alkali was 10 seconds. To a half of the animals corneal burn correction was done with the help of cryophilic pig skin
extract. Beginning with the first day of the experiment the extract of cryophilic pig skin was applied into the conjunctiva sac 1 drop after every 2 hours,
during three days. Other 12 rabbits didn’t benefit from the extract correction.
Results: The results obtained proved that using cryophilic pig skin extract allowed to improve significantly regeneration processes in cornea tissues
after alkali burn. Epithelialization of a damaged area is fulfilled faster and better. It is demonstrated by the increase in the number of epithelial cells and
their earlier differentiation as well as the increase of regulation of connective-tissue fibers leading to a more effective improvement of the optical features
of the damaged area.
Conclusions: It is assumed that this correction method enables the surface epithelium to regenerate due to division and migration of cornea basement
epithelial cells as well as transformation and centre-oriented movement of limbus cambial (stem) cells that has already been mentioned in previous
publications
Anti-corrosion ceramic coatings on the surface of Nd-Fe-B repelling magnets
The results of vacuum-arc deposition of thin ZrO₂coatings to protect the surface of Nd-Fe-B permanent magnets used as repelling devices in orthodontics are presented. The structure, phase composition and mechanical properties of zirconium dioxide films have been investigated by means of SEM, XRD, EDX, XRF and nanoindentation method. It was revealed the formation of polycrystalline ZrO₂ films of monoclinic modification with average grain size 25 nm. The influence of the ZrO₂ coating in terms of its barrier properties for corrosion in quasi-physiological 0.9 NaCl solution has been studied. Electrochemical measurements indicated good barrier properties of the coating on specimens in the physiological solution environment
Multivariate evaluation by quality indicators of no-tillage system in Argiudolls of rolling pampa (Argentina)
Abstract The purpose of this study was to develop operationally important soil quality indicators to evaluate longterm sustainability, at the farm scale, for no-tillage systems in Argiudolls of rolling pampa (Argentina). The soil was classified as series Arroyo Dulce (Typic Argiudoll), a fertile dark, deep and well-drained soil of the hills. Three situations were considered: pristine soil with grass vegetation, grassland soil (also considered as a reference situation); and 15 years no-tillage soils from four production plots. Physical, physico-chemical, chemical and biochemical indicators were considered. Data were analyzed by principal components analysis (PCA) with canonical discriminant analysis (CDA). The first three components explained 90% of the overall variation. For pristine undisturbed soil, the main variables selected by PCA were particulate C, pH, respiration and total organic C, and in the case of grassland they were C stock (mass of C in the 0-10 cm soil horizon), water-soluble C, and % silt. The no-tillage area was separated in different plots according to the degree of erosion with different depths of the A horizon. Clay content and bulk density were the main variables in the less degraded no tillage plots. Cluster analysis was applied to construct an average linkage distance dendrogram
Investigation of the quasifission process by theoretical analysis of experimental data of fissionlike reaction products
The fusion excitation function is the important quantity in planning
experiments for the synthesis of superheavy elements. Its values seem to be
determined by the experimental study of the hindrance to complete fusion by the
observation of mass, angular and energy distributions of the fissionlike
fragments. There is ambiguity in establishment of the reaction mechanism
leading to the observed binary fissionlike fragments. The fissionlike fragments
can be produced in the quasifission, fast fission, and fusion-fission processes
which have overlapping in the mass (angular, kinetic energy) distributions of
fragments. The branching ratio between quasifission and complete fusion
strongly depends on the characteristics of the entrance channel. In this paper
we consider a wide set of reactions (with different mass asymmetry and mass
symmetry parameters) with the aim to explain the role played by many quantities
on the reaction mechanisms. We also present the results of study of the
Ca+Bk reaction used to synthesize superheavy nuclei with Z = 117
by the determination of the evaporation residue cross sections and the
effective fission barriers of excited nuclei formed along the
de-excitation cascade of the compound nucleus.Comment: 21 pages, 15 figures, 2 table
Combined visual and biochemical analyses confirm depositor and diet for Neolithic coprolites from Skara Brae
Coprolites (fossilized faeces) can provide valuable insights into species’ diet and related habits. In archaeozoological contexts, they are a potential source of information on human-animal interactions as well as human and animal subsistence. However, despite a broad discussion on coprolites in archaeology, such finds are rarely subject to detailed examination by researchers, perhaps due to the destructive nature of traditional analytical methods. Here, we have examined coprolitic remains from the Neolithic (third millennium BCE) settlement at Skara Brae, Orkney, using a range of modern methods: X-ray computed tomography, scanning electron microscopy, lipid and protein analysis (shotgun proteomics of the coprolite matrix as well as collagen peptide mass fingerprinting of isolated bone fragments). This combined approach minimised destructiveness of sampling, leaving sufficient material for subsequent study, while providing more information than traditional morphological examination alone. Based on gross visual examination, coprolites were predominantly attributed to domestic dogs (Canis familiaris), with morphologically identified bone inclusions derived from domestic sheep (Ovis aries) and common voles (Microtus arvalis). Partial dissection of a coprolite provided bone samples containing protein markers akin to those of domestic sheep. Considering the predominance of vertebral and distal limb bone fragments, Skara Brae dogs were probably consuming human butchery or meal refuse, either routinely fed to them or scavenged. The presumably opportunistic consumption of rodents may also have played a role in pest control
Effects of Sure Start local programmes on children and families: early findings
Objective To evaluate the effects of Sure Start local programmes (SSLPs) on children and their families. To assess whether variations in the effectiveness of SSLPs are due to differences in implementation.
Design Quasi-experimental cross sectional study using interviews with mothers and cognitive assessment of children aged 36 months who speak English.
Setting Socially deprived communities in England: 150 communities with ongoing SSLPs and 50 comparison communities.
Participants Mothers of 12 575 children aged 9 months and 3927 children aged 36 months in SSLP areas; mothers of 1509 children aged 9 months and 1101 children aged 36 months in comparison communities.
Outcome measures Mothers' reports of community services and local area, family functioning and parenting skills, child health and development, and verbal ability at 36 months.
Results Differences between SSLP areas and comparison areas were limited, small, and varied by degree of social deprivation. SSLPs had beneficial effects on non-teenage mothers (better parenting, better social functioning in children) and adverse effects on children of teenage mothers (poorer social functioning) and children of single parents or parents who did not work (lower verbal ability). SSLPs led by health services were slightly more effective than other SSLPs.
Conclusion SSLPs seem to benefit relatively less socially deprived parents (who have greater personal resources) and their children but seem to have an adverse effect on the most disadvantaged children. Programmes led by health services seem to be more effective than programmes led by other agencies
The student patient alliance: development and formative evaluation of an initiative to support collaborations between patient and public involvement partners and doctoral students
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