A study of spinal deformities in third and fourth grade students

Spinal deformities are an increasingly common problem in the adolescent population. They are caused by improper posture when walking, sitting, standing or by a pathological agent. We distinguish scoliosis, lordosis, and kyphosis, which can be observed in all three planes. Even spinal deformities can be structural and functional. Spinal deformities are increasing progressively nowadays, and poor posture has become an integral part of the daily lives of children and adults. The project „Healthy and active“ aims to educate children from the 132 SS „Vanya Voynova“ on correct motor habits. The children were examined and diagnosed for deviations from the correct posture and distortions in the area of the spine. After the study, a kinesitherapeutic complex was developed to combine corrective gymnastics with games. In this way, all of the children‘s attention is engaged during the lessons. The project is finalized with an anonymous survey of children. The obtained results show that 91.3% of the respondents give a positive assessment of and feedback on the event

Factors influencing the crystallization, phase and oxygen vacancy concentration in zirconia

In order to achieve a better understanding of the processes that occur during formation and sintering of zirconia, various chemical and physical techniques were used. Along with Perturbation Angular Correlation spectroscopy, that allowed us to investigate microscopic properties inside the nanometer-size zirconia grains, such techniques as Scanning Electron Microscopy and X-ray diffraction were used for determining the size of particles before and after sintering, and Neutron Activation Analysis was employed for measuring the impurity levels in zirconia powders. By controlling the initial conditions and heat treatment of the powders, we investigated the dependence of formation of the charged defects on the existing molecular structure and morphology of zirconia particles. During the study, it was discovered that at low temperature the PAC frequencies of tetragonal zirconia behave very similarly for all materials that were used in this study. If stabilization is achieved by heavy doping, there are shifts and line-broadening due to the presence of dopants but no obvious differences in the essential physics. One material included in this group is Nb-doped zirconia that has no oxygen vacancies. It was concluded that there are no detectable oxygen vacancies in our pure or lightly doped tetragonal zirconia powders before they are heated into the temperature region where sintering occurs. Vacancies are incorporated as the samples are heated above 1050°C, the temperature at which sintering becomes important. The oxygen vacancies in samples that have been heated to 1200°C remain when cooled. We see no vacancy concentration dependence on the atmosphere for samples not doped with +5 valent elements in order to reduce the vacancy density at 1200°C. In several instances, samples that had been heated to a maximum temperature of 1050°C or 1100°C contained a vacancy density that was small (<100 ppm) but measurable. A reduced oxygen pressure increased the oxygen vacancy density by a measurable amount in these samples. Samples that are tetragonal at 800°C are well-sintered after being heated to 1200°C. Samples that are monoclinic below 1170°C are very poorly sintered at 1200°C and contain few vacancies. Flowing Cl in the system as the samples are sintering retards the densification of the grains. These samples had the smallest density of oxygen vacancies

“Я–образ” младших школьников как фактор социально-психологической адаптации детей в коллективе художественной самодеятельности

У статті наводяться дані емпіричного дослідження щодо впливу “Я–Образу” на рівень соціально-психологічної адаптації дітей молодого шкільного віку у колективі художньої самодіяльності.The paper presents results of the empirical research on impact of ‘Self-image’ on psychological adaptation of primary school students in the amateur talent groups.В статье приводятся данные эмпирического исследования о влиянии «Я-образа» на уровень психологической адаптации детей младшего школьного возраста в коллективе художественной самодеятельности

Absence of long-range chemical ordering in equimolar FeCoCrNi

Equimolar FeCoCrNi alloys have been the topic of recent research as "high-entropy alloys," where the name is derived from the high configurational entropy of mixing for a random solid solution. Despite their name, no systematic study of ordering in this alloy system has been performed to date. Here, we present results from anomalous x-ray scattering and neutron scattering on quenched and annealed samples. An alloy of FeNi_3 was prepared in the same manner to act as a control. Evidence of long-range chemical ordering is clearly observed in the annealed FeNi_3 sample from both experimental techniques. The FeCoCrNi sample given the same heat treatment lacks long-range chemical order

Control of octahedral rotations in (LaNiO3_3)n_{n}/(SrMnO3_3)m_m superlattices

Oxygen octahedral rotations have been measured in short-period (LaNiO$_3$)$_n$/(SrMnO$_3$)$_m$ superlattices using synchrotron diffraction. The in-plane and out-of-plane bond angles and lengths are found to systematically vary with superlattice composition. Rotations are suppressed in structures with $m>n$, producing a nearly cubic form of LaNiO$_3$. Large rotations are present in structures with $m<n$, leading to reduced bond angles in SrMnO$_3$. The metal-oxygen-metal bond lengths decrease as rotations are reduced, in contrast to behavior previously observed in strained, single layer films. This result demonstrates that superlattice structures can be used to stabilize non-equilibrium octahedral behavior in a manner distinct from epitaxial strain, providing a novel means to engineer the electronic and ferroic properties of oxide heterostructures.Comment: 4 pages, 4 figures, submitted to PR

First Direct Observation of Nanometer size Hydride Precipitations on Superconducting Niobium

Superconducting niobium serves as a key enabling material for superconducting radio frequency (SRF) technology as well as quantum computing devices. At room temperature, hydrogen commonly occupies tetragonal sites in the Nb lattice as metal (M)-gas (H) phase. When the temperature is decreased, however, solid solution of Nb-H starts to be precipitated. In this study, we show the first identified topographical features associated with nanometer-size hydride phase (Nb1-xHx) precipitates on metallic superconducting niobium using cryogenic-atomic force microscopy (AFM). Further, high energy grazing incidence X-ray diffraction reveals information regarding the structure and stoichiometry that these precipitates exhibit. Finally, through time-of-flight secondary ion mass spectroscopy (ToF-SIMS), we are able to locate atomic hydrogen sources near the top surface. This systematic study further explains localized degradation of RF superconductivity by the proximity effect due to hydrogen clusters

The Effects of Small Metal Additions (Co,Cu,Ga,Mn,Al,Bi,Sn) on the Magnetocaloric Properties of the Gd5Ge2Si2 Alloy

The structural and magnetic properties of arc-melted and homogenized (1300 °C, 1 h) alloys of Gd5Ge1.9Si2X0.1 (X = Cu, Co, Ga, Mn, Al, Bi, or Sn) were investigated by powder x-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and magnetometry. The addition of Cu, Ga, Mn, and Al completely eliminated the large hysteresis losses present in the undoped Gd5Ge2Si2 alloy between 270 and 330 K, broadened the magnetic entropy change ΔSm peak, and shifted its peak value from 275 to 305 K similar to that observed earlier for Gd5Ge1.9Si2Fe0.1. The addition of Bi or Sn had a negligible effect on either the alloy hysteresis losses or the characteristics of the ΔSm vs T peak. The microstructure of the alloy doped with Cu, Co, Ga, Mn, or Al consisted of a majority phase (depleted of silicon) and a minor intergranular phase (rich in silicon and of the corresponding metal additive). For Bi or Sn doping, the microstructure consisted of only the Gd5Ge2Si2 phase. Low temperature x-ray diffraction data on an Fe-doped sample showed the same spectra at 245 and 300 K, consistent with the majority phase possessing an orthorhombic structure. Refrigeration capacity calculations show that Gd5Ge1.9Si2X0.1 (X = Fe,Cu,Co,Ga,Mn, or Al) alloys are superior magnetic refrigerants compared to the undoped Gd5Ge2Si2 alloy