Supply Of Vacancies Research Articles

HISTÓRIA RECENTE DA EXPANSÃO DO ENSINO SUPERIOR NO BRASIL: 1990 A 2020

Brazilian higher education has its origins in an ingrained elitist tendency, serving a public from the highest social strata and with a tradition in higher education. However, there was a significant demand for progression in studies, putting pressure on the government to correct the gap between the supply of vacancies and the demand for higher education. Thus, several policies were aimed at democratizing this level of expansion. The present study seeks to carry out a survey and discussion about public policies aimed at the expansion of higher education implemented in the recent history of the country, since 1990. In order to obtain an understanding of how the current university structure in the country was conceived, and how its audience was characterized. This analysis was carried out through official documents available in the Official Gazette of the Union, as well as published by the responsible public entities. Also included are budgetary data from public transparency and statistical synopses from higher education educational censuses. It appears that the country's social inequalities are reflected in educational inequalities. In this way, public policies implemented aimed at mitigating such inequalities stand out. Faced with the difficulties of structuring the public system to absorb all high school graduates, private HEIs took better advantage of the public policies of that period and continued to expand.

РАБОЧИЕ МЕСТА ДЛЯ ЛЮДЕЙ С ОГРАНИЧЕННЫМИ ВОЗМОЖНОСТЯМИ: ПРОБЛЕМЫ И ПЕРСПЕКТИВЫ РАЗВИТИЯ В УСЛОВИЯХ ЦИФРОВИЗАЦИИ ЭКОНОМИКИ

Today, the creation of jobs for people with disabilities is an urgent topic. The issue stems from the fact that companies do not have an incentive to hire such workers. That is caused by the fact that Russia does not have an effective economic policy for the employment of citizens with disabilities. As a result, the country loses part of the labor force and slows down economic growth. At the same time, the state does not provide an appropriate social support system for disabled people, without providing them with the opportunity to move from the passive role of a recipient of benefits to an active and full-fledged life. Among other things, it is worth paying attention to the social aspect of the mentioned challenge. Unfortunately, in Russia, people with disabilities are discriminated against by the whole society, including employers. That is due to the shortcomings of state laws and the lack of coverage of the topic. Paying attention to that issue, the state plans to develop the labor market and increase the number of working people with disabilities from 13% of all employed to 50% or more. To solve the task, it is necessary to improve the state laws regulating the situation. In addition, there is a prospect of rapid development in employment of people with disabilities. As a result of the last pandemic, there has been a change in the labor market – the supply of vacancies on a remote basis has increased. With the help of a remote type of work, it will become more accessible to develop an employment environment for citizens with disabilities. However, the implementation of such a plan requires the participation of the state.

Ринок праці України в сучасних умовах: проблеми та напрями їх вирішення

The purpose of the article is to identify problems in the labor market of Ukraine in the difficult conditions of today, to find effective directions for their solution and conditions for optimizing the supply and demand of labor. To solve the set tasks, general scientific and special research methods were used, i. e.: generalization, analysis and synthesis, comparison and systematization, observation. The article considers the factors that influenced the emergence of disproportions in the labor market before the war, and expands the list of factors due to those added to the indicated ones after the onset of the full-scale invasion of the Russian Federation and negatively affect the labor market of Ukraine. A number of functions that the labor market performs during its formation and functioning are listed. The problems that have arisen in the situation with work and internship among the population of Ukraine since the onset of the full-scale war have been identified. The difficulties faced by the respondents when looking for a new job are considered; the priority of actions for the possibility of further employment is specified. Uneven indicators of demand and supply of vacancies in the labor market are indicated. The performance indicators of the State Employment Service after the onset of the war are analyzed and compared with the indicators of the previous period. The article substantiates the importance of a quick reaction on the part of the State, employers and the population to uncontrolled environmental factors. Directions for solving problems to reduce unemployment, achieve a balance between demand and supply of vacancies, and adjust the employment system are proposed.

Ограниченный спрос в модели рынка труда Российской Федерации на примере молодых специалистов

A study by scientists of the Russian State Social University, which examines the problems of limited demand in the labor market in the Russian Federation. The subject of the study is the labor market, and the object of the study is the supply of vacancies on the labor market by young job seekers. The study is based on previous studies of the essence of the labor market phenomenon within the framework of the postulates of the institutional school of economic theory.

Minding the gap between schools and universities

During the 2000s decade, governments in South America reallocated per-student public expenditures from tertiary to basic education, potentially alleviating the economic gap between students in public schools and public universities. To investigate the welfare and macroeconomic effects of such types of policies, we build and calibrate a general equilibrium model using Brazilian data from the beginning of the 2000s. We find that the optimal utilitarian policy allocates per-student public expenditures equally across education stages, benefits almost the entirety of households, delivers significant welfare gains to the poorest families, and cuts back income inequality. We also use our framework to investigate economic differences between Brazil and the United States, and find that differences in the supply of vacancies in public universities is the education policy aspect that, alone, has the highest explanatory power over aggregate earnings and college attendance differences between the two countries.

Diffusion properties of n-type dopants diffused from spin on glass into Ge

Solid phase diffusion properties of three typical n-type dopants (P, As, and Sb) in Ge have been studied through experimental depth profiles of dopants diffused from spin on glass (SOG) films. Numerical calculations of dopant profiles in Ge are performed to extract the diffusion constant through comparison with the experimental profiles. It is pointed out that experimental results of diffusion at low temperature are important to correctly examine the influence of negative charge states of a vacancy on dopant diffusion. It is found that vacancies with the charge states of −2 mediate the diffusion of P and As without implantation-induced defects. The diffusion constants of P and As, obtained in this study, are larger than those for intrinsic diffusion, while that of Sb is almost the same as that for intrinsic diffusion. The present larger diffusion constants of P and As can be explained by the supply of vacancies from Ge surfaces via E-centers during diffusion from SOG.

Reorganização da agenda e do modelo de acesso em Unidade de Saúde da Família 24 horas

Problema: As longas filas e a dificuldade de atendimento nas Unidades de Saúde da Família (USF) são uma realidade conhecida no Brasil. O acesso avançado representa uma nova proposta de acolhimento e gestão da oferta de vagas para consultas. Neste contexto de dificuldade de acesso, foi inaugurada em março de 2016 em Recife, uma nova Unidade de Saúde da Família 24 horas. Após 6 meses de atendimento neste serviço, a equipe Alfa, nome fictício, sentia-se desmotivada pelas reclamações relativas à dificuldade de acesso. Mobilizada pela insatisfação da população foi proposta uma intervenção para reorganização da oferta de vagas para consultas e do modelo de agendamento com base no acesso avançado. O objetivo deste trabalho é relatar a experiência de reorganização da agenda e da oferta de vagas para consultas; as mudanças do número e do tipo dos atendimentos da equipe após implantação deste novo modelo de acesso; e a percepção dos integrantes da equipe quanto à experiência. Métodos: A primeira etapa da iniciativa incluiu a identificação da viabilidade da intervenção a partir do cálculo da demanda diária de atendimentos. Em seguida, foi criado um novo modelo de agenda desenvolvido fora do e-SUS e que utilizava o Google® Drive e disponibilizados três tempos para as consultas: 5 minutos, 10 minutos e 20 minutos, denominadas respectivamente de rápida, intermediária e estendida. Resultados: No terceiro mês após a mudança foi observado o desaparecimento dos atendimentos classificados como urgência pelo antigo modelo, a ampliação de 65% no número de atendimentos da equipe Alfa com transformação do perfil de atendimento de 70% de consultas agendadas para 70% de consultas do dia. Conclusão: A experiência mostrou ser possível uma ampliação no acesso através do incremento no número de atendimentos a partir da reorganização da agenda baseada no modelo de acesso avançado.

Engineering self-organising helium bubble lattices in tungsten

The self-organisation of void and gas bubbles in solids into superlattices is an intriguing nanoscale phenomenon. Despite the discovery of these lattices 45 years ago, the atomistics behind the ordering mechanisms responsible for the formation of these nanostructures are yet to be fully elucidated. Here we report on the direct observation via transmission electron microscopy of the formation of bubble lattices under He ion bombardment. By careful control of the irradiation conditions, it has been possible to engineer the bubble size and spacing of the superlattice leading to important conclusions about the significance of vacancy supply in determining the physical characteristics of the system. Furthermore, no bubble lattice alignment was observed in the <111> directions pointing to a key driving mechanism for the formation of these ordered nanostructures being the two-dimensional diffusion of self-interstitial atoms.

Relação entre condição socioeconômica e rendimento acadêmico.

Os cursos técnicos no Brasil tiveram um grande aumento na oferta de vagas a partir de 2002, quando o Governo Federal passou a investir nesse seguimento educacional. Para ampliar as vagas, utilizou-se da estrutura existente nos antigos Centros Federais de Educação Técnica – CEFET’s. Esses Centros foram transformados em Institutos Federais de Ciência e Tecnologia, possibilitando a criação de uma nova estrutura, mais dinâmica e abrangente. Dentro dessa proposta, no ano de 2008, o CEFET-Nilópolis foi transformado em Instituto Federal de Educação, Ciência e Tecnologia do Estado do Rio de Janeiro – IFRJ. Atualmente conta com 11 campi, distribuídos pelo Estado do Rio de Janeiro. O Campus IFRJ – Arraial do Cabo foi implantado em 2006 e conta com cursos Técnicos em Meio Ambiente e Informática. O Técnico em Informática Integrado ao Ensino Médio foi implantado no ano de 2011. Desde sua implantação – mesmo tomando várias medidas que contribuíam para o desempenho acadêmico –, esse curso vem apresentando números elevados de reprovação/retenção. Diante dessa realidade, surgiu a necessidade de investigar a relação existente entre situação socioeconômica e rendimento acadêmico. Para realizar este estudo, utilizaram-se dados coletados através de entrevista semiestruturada com alunos e levantamento documental do Registro Escolar. A análise constata que, quanto maior a inserção econômica e social, melhor será o rendimento acadêmico. Assim, aponta-se a necessidade de investimentos em políticas sociais e pedagógicas que reconheçam as especificidades socioeconômicas destes alunos, respeitando limitações e possibilidades identificadas.

Helium bubble formation in ultrafine and nanocrystalline tungsten under different extreme conditions

We have investigated the effects of helium ion irradiation energy and sample temperature on the performance of grain boundaries as helium sinks in ultrafine grained and nanocrystalline tungsten. Irradiations were performed at displacement and non-displacement energies and at temperatures above and below that required for vacancy migration. Microstructural investigations were performed using Transmission Electron Microscopy (TEM) combined with either in-situ or ex-situ ion irradiation. Under helium irradiation at an energy which does not cause atomic displacements in tungsten (70eV), regardless of temperature and thus vacancy migration conditions, bubbles were uniformly distributed with no preferential bubble formation on grain boundaries. At energies that can cause displacements, bubbles were observed to be preferentially formed on the grain boundaries only at high temperatures where vacancy migration occurs. Under these conditions, the decoration of grain boundaries with large facetted bubbles occurred on nanocrystalline grains with dimensions less than 60nm. We discuss the importance of vacancy supply and the formation and migration of radiation-induced defects on the performance of grain boundaries as helium sinks and the resulting irradiation tolerance of ultrafine grained and nanocrystalline tungsten to bubble formation.

Kerfless layer-transfer of thin epitaxial silicon foils using novel multiple layer porous silicon stacks with near 100% detachment yield and large minority carrier diffusion lengths

Two important aspects for the success of the porous silicon-based layer transfer method in producing kerfless thin (<50µm) silicon foils for future silicon solar modules are addressed in this work: achieving high detachment yield and high minority carrier diffusion lengths. The detachment characteristics of the porous silicon-based lift-off process is studied using finite element modeling as well as experiments. It is shown that for easy detachment and high detachment yield, a low density of thin silicon pillars must be attained in the high porosity detachment layer (HP-DL) after high temperature sintering. This is elegantly achieved by increasing the thickness of the low porosity template layer (LP-TL) which acts as the vacancy supply to increase the post-anneal porosity of the HP-DL. In this way, near 100% detachment yield has been achieved. However, a thicker LP-TL results in a poorer quality epitaxial growth surface. To circumvent this trade-off, novel triple and quadruple layer porous silicon stacks are introduced which decouple the function of the LP-TL that acts as both the template for epitaxy and as the vacancy supply for the HP-DL. In these new stacks, a surface zone of very low void size and density (nearly void-free) is created which allows high quality epitaxy on easily-detachable porous silicon stacks. Minority carrier lifetime measurements on epitaxial foils grown on such a triple layer stack has resulted in an effective lifetime of ~350µs at the injection level of 1015cm−3 which corresponds to a minimum minority carrier diffusion length of ~670µm (> 16 times the silicon thickness). With such high quality epitaxial foils combined with high detachment yield, very high efficiency solar devices on thin silicon substrates would be a reality in the near future.

Forming-free Resistance Random Access Memory Using Ta2O5/TaOx Bi-layer Prepared by Magnetron Sputtering Method

ABSTRACTThis paper describes proposal of ReRAM switching mechanism, development of production tool for ReRAM sputtering and improvement in TaOx-ReRAM switching characteristics. We propose that a ReRAM-cell has stack a structure in which an oxygen vacancy supply layer (TaOx) and an oxygen accumulation layer (Ta2O5) sandwiched by the top and bottom electrodes. Resistance change of the ReRAM-cell is caused by the oxygen vacancies migrating between the TaOx and the Ta2O5 layers by applied voltage. This prediction corresponded to the experimental facts. The thickness of Ta2O5 film sputtered by a mass production tool had good uniformity (±1.0%) and excellent stability (±1.0%). Also the sheet resistance uniformity (1σ) of TaOx film had 3.6%. By examining the sputtering conditions, the ReRAM-cell having a Ta2O5/TaOx bi-layer operated in less than 100μA with a forming-free and had excellent endurance property to 1010 cycles at 50nsec.

Phase-field modeling of gas bubbles and thermal conductivity evolution in nuclear fuels

A phase-field model was developed to simulate the accumulation and transport of fission products and the evolution of gas bubble microstructures in nuclear fuels. The model takes into account the generation of gas atoms and vacancies, and the elastic interaction between diffusive species and defects as well as the inhomogeneity of elasticity and diffusivity. The simulations show that gas bubble nucleation is much easier at grain boundaries than inside grains due to the trapping of gas atoms and the high mobility of vacancies and gas atoms in grain boundaries. Helium bubble formation at unstable vacancy clusters generated by irradiation depends on the mobilities of the vacancies and He, and the continuing supply of vacancies and He. The formation volume of the vacancy and He has a strong effect on the gas bubble nucleation at dislocations. The effective thermal conductivity strongly depends on the bubble volume fraction, but weakly on the morphology of the bubbles.

Positron annihilation study of vacancy-type defects in stoichiometric and non-stoichiometric Al–Cu–Fe quasicrystalline alloys

Vacancy-type defects in a non-stoichiometric quasicrystalline phase of Al–Cu–Fe coatings obtained by electron beam deposition have been studied using positron annihilation measurements. It is shown that quasicrystalline phase of non-stoichiometric composition in the coating contains more of vacancy-type defects than the stoichoimetric one in bulk specimen. Decomposition of the quasicrystalline phase during the annealing of the coatings is accompanied by the formation of microvoids, as a consequence of supply of vacancies from the icosahedral structure. The presence of vacancies which maintains the average electron concentration per unit cell at the appropriate value, may be reason of the extended compositional range of icosahedral phase in the coatings.

Microstructural Change during FeSi2 (.BETA.-phase) Formation and the Cause for Acceleration of the Formation Rate by Addition of Pd in Mn-doped Fe-66.7at%Si Alloy.

The microstructural change during the formation of semiconductive FeSi2 (β-phase) from FeSi (e-phase) and Fe2Si5 (α-phase) two metallic compounds by isothermal heating at 1123 K in Mn-doped Fe-66.7at%Si alloys which were prepared by both melting-solidification and sintering processes was firstly investigated, paying attention to the following peculiar phenomenon; some e-phase particles were covered with β-phase layer and the others were not in solidified alloy. Secondly, the cause for the acceleration of β-phase formation rate by the addition of Pd was investigated. It was found that there were two kinds of α-phases; the one (α ?? ) decomposed to β- and Si phases by the eutectoid reaction and the other (αs) did not by the heating for up to 180 ks. The formations of two kinds of band-shaped regions which were caused by both these two kinds of α-phases and the eutectic reaction of the liquid were judged to be the causes for the peculiar phenomenon. The acceleration of β-phase formation rate by addition of Pd was attributed to both the increase of the α, -phase amount ratio and the acceleration of the eutectoid reaction of a, phase. In the consideration on non-shrinkage of α-phase particles inside test piece, a new hypothesis of extinction in the core of core-rim structure which stops the vacancy supply to the core/rim interface or the reaction at the core/rim interface was proposed.

Nucleation of recrystallization in boron doped Ni 3Al

The microstructural changes and the early stages of recrystallization were investigated during annealing of cold rolled boron doped Ni 3Al. Hot stage TEM experiments allowed the in-situ observation of the microstructure development during annealing. Samples from bulk annealed material were examined for comparison. No cell formation took place in the grain interior during deformation, but subgrains appeared at the high angle grain boundaries of the deformed matrix during annealing, often followed by grain boundary bulging. Nucleation occurred preferentially at prior grain boundaries for low to intermediate degrees of rolling, but at shear bands after large deformation. Twinning and the formation of twin chains were observed even at incipient stages of recrystallization. It is proposed to attribute the accelerated recovery at grain boundaries to an enhanced vacancy supply in the vicinity of the grain boundaries. A simple dislocation model is introduced to account for subgrain and bulge formation at grain boundaries.

Electromigration failure in a finite conductor with a single blocking boundary

The (one-dimensional) electromigration boundary-value problem is considered for the case of a single blocking boundary with a constant vacancy supply at the other boundary. Using the drift/diffusion model expressed by the Fokker–Planck equation, we find that the saturation time (tsat) increases exponentially with current density (j) and not as j−2, as has been suggested. However, it is not the saturation time which determines the lifetime (tbd); it is the time to reach some critical vacancy concentration (c*). In agreement with experimental results and numerical calculations, we find that tbd∼j−2. We also find that tbd∼c*.

Positron study of defects in as-grown and plastically deformed GaAs:Te.

Point defects were studied by positron-lifetime spectroscopy in highly Te-doped GaAs, in the as-grown state, and after plastic deformation. In as-grown GaAs:Te, positron trapping to vacancylike defects, supposed to be the compensating centers ${\mathrm{Te}}_{\mathrm{As}}$${\mathit{V}}_{\mathrm{Ga}}^{\mathrm{\ensuremath{-}}}$, was observed. At low temperatures (T200 K), additional trapping is caused by shallow positron traps, probably by ${\mathrm{Ga}}_{\mathrm{As}}^{\mathrm{\ensuremath{-}}}$ antisite defects. In two differently deformed samples, additional defects were identified as microvoids, consisting of not less than ten vacancies. The dominating vacancy supply mechanism for vacancy agglomeration is the dragging of jogs on screw dislocations. The microvoids almost completely anneal after thermal treatment at 1075 K. The density of shallow traps increased after deformation by about one order of magnitude as a result of dislocation climb. These shallow traps additionally formed during plastic deformation exhibit the same positron binding energy, ${\mathit{E}}_{\mathit{b}}$=43 meV, as found in as-grown material. This part could be annealed at 1000 K, whereas the part of shallow traps originally present is determined by the nonstoichiometry and is therefore thermally stable. The density of the compensating centers remains almost unchanged after deformation. They are thermally stable up to 1075 K.

Formation and growth of intragranular fission gas bubbles in UO 2 fuels with burnup of 6–83 GWd/t

The detailed characteristics of intragranular fission gas bubbles in UO 2 fuel pellets (burnup: 6–83 GWd/t) before and after postirradiation annealing at 1600 and 1800°C have been examined by TEM and SEM fractography. In the base-irradiated fuels, a high density of small bubbles of about 2 nm in diameter precipitated uniformly in the matrix. When increasing burnup above 44 GWd/t, larger bubbles of 10–20 nm newly appeared in addition to the small bubbles. On heating at high temperatures, bubble growth was saturated within a few minutes. Enhanced coarsening of bubbles was found preferentially near the grain boundaries in the middle burnup fuels of 16–28 GWd/t and throughout the grains in the high burnup fuels of 44 and 83 GWd/t. The bubble growth during annealing was associated with a remarkable decrease of the bubble number density, and the relationship between bubble density N b and mean diameter d b was expressed as N b α d b −2.6. The coarsening was attributed to coalescence via bubble migration for moderately large bubbles of up to 50–60 nm, and to Ostwald ripening accompanied by a sufficient vacancy supply from external vacancy sources such as free surfaces, grain boundaries or irradiation-induced sub-grain boundaries for huge bubbles above 100 nm.

Rapid thermal diffusion of zinc into GaAs

Rapid thermal diffusion of zinc into semi-insulating GaAs from spin-on Zn doped silica film was performed. Spin-on films act both as Zn diffusion sources and GaAs surface encapsulant layer against decomposition during the rapid thermal diffusion. The very shallowp + layers were obtained at a diffusion temperature of 900° C for 5 sec. Non-alloyed ohmic contacts to thesep + layers were achieved with an average contact resistivity of 2.4 × 10−6 Ω cm2. The interface is very smooth. The zinc diffusion coefficient for rapid thermal diffusion with effective diffusion time of 6 sec at 900° C was numerically calculated from SIMS profiles. In contrast to the common Longini-Weisberg-Blanc model, the rapid thermal diffusion is under nonequilibrium condition. Complications due to interstitial-substitutional nonequilibrium, vacancy supply resulted from the interface stress field, and zinc precipitation are briefly discussed.