2,294 research outputs found
Plasmon channels in the electronic relaxation of diamond under high-order harmonics femtosecond irradiation
We used high order harmonics of a femtosecond titanium-doped sapphire system
(pulse duration 25 fs) to realise Ultraviolet Photoelectron Spectroscopy (UPS)
measurements on diamond. The UPS spectra were measured for harmonics in the
range 13 to 27. We also made ab initio calculations of the electronic lifetime
of conduction electrons in the energy range produced in the UPS experiment.
Such calculations show that the lifetime suddenly diminishes when the
conduction electron energy reaches the plasmon energy, whereas the UPS spectra
show evidence in this range of a strong relaxation mechanism with an increased
production of low energy secondary electrons. We propose that in this case the
electronic relaxation proceeds in two steps : excitation of a plasmon by the
high energy electron, the latter decaying into individual electron-hole pairs,
as in the case of metals. This process is observed for the first time in an
insulator and, on account of its high efficiency, should be introduced in the
models of laser breakdown under high intensity
Evo-devo of human adolescence: beyond disease models of early puberty
Despite substantial heritability in pubertal development, much variation remains to be explained, leaving room for the influence of environmental factors to adjust its phenotypic trajectory in the service of fitness goals. Utilizing evolutionary development biology (evo-devo), we examine adolescence as an evolutionary life-history stage in its developmental context. We show that the transition from the preceding stage of juvenility entails adaptive plasticity in response to energy resources, other environmental cues, social needs of adolescence and maturation toward youth and adulthood. Using the evolutionary theory of socialization, we show that familial psychosocial stress fosters a fast life history and reproductive strategy rather than early maturation being just a risk factor for aggression and delinquency. Here we explore implications of an evolutionary-developmental-endocrinological-anthropological framework for theory building, while illuminating new directions for research
External-environmental and internal-health early-life predictors of adolescent development
External-environmental and internal-health early-life predictors of adolescent development
Authors' preprin
Critical Housing Finance Challenges for Policy Makers
Examines barriers for mortgage lending to underserved groups and in distressed neighborhoods, such as risk assessment; financing for multifamily rental markets, such as affordability; and financing for sustainable housing, such as transactional costs
Применение гибридных накопителей электроэнергии для выравнивания графика нагрузки предприятий
In this article, the authors consider the possibility of using a hybrid energy storage system to even out the load profile of the enterprise. Solving the problem of rational use of energy storage taking into account the initial variable load schedule will significantly reduce not only the cost of electricity consumption by the enterprise, but also the costs of its production. Detailed characteristics of batteries with various types of electrolytes and supercapacitors are given. A model of the active scheme of a hybrid electric energy storage system consisting of a lithium-ion battery and a supercapacitor unit with the corresponding characteristics is presented. The model was carried out by using the SimPowerSystems software in MatLab. During the simulation, the temperature and the aging effects and of the batteries were not taken into account. The selfdischarge parameter of the battery was also not presented. As a result of the simulation, discharge characteristics of supercapacitors and batteries were obtained based upon which the expediency of their combined use for leveling load profiles of various types was substantiated. The paper presents the results of the simulation of operating modes of a hybrid energy storage device, combining the advantages of two types of energy storage devices, as well as a diagram of delivered power to the network, corresponding to the specified parameters. The paper provides a mathematical description of the increasing power by hybrid storage system resulting from the combined use of supercapacitors and batteries. The paper presents the dependence of the power increase ratio on the frequency and the pulse current duty ratio, which proves that the maximum possible output power of the hybrid storage system can be several times greater than the power of a single battery having the same parameters
Investigation of the effect of combined thermomechanical processing on the brass microstructure evolution and the microhardness change
The article investigates the effect of combined thermomechanical processing, including pre-heat treatment and radial-shear rolling on the brass microstructure evolution and the microhardness change. The microstructure analysis of heat-treated samples according to various modes showed that the most optimal heat treatment before radialshear rolling for L63 brass is annealing at a temperature of 500 °C. As a result of combined thermomechanical processing, a gradient structure was obtained, so in the resulting rods with a diameter of 16 mm in the surface layer, a structure with an average grain size of 9 μm was obtained. In rods with a diameter of 12 mm, a fine–grained, equalgrained structure of 3 μm was obtained in the surface layer
Credit scores, cardiovascular disease risk, and human capital.
Credit scores are the most widely used instruments to assess whether or not a person is a financial risk. Credit scoring has been so successful that it has expanded beyond lending and into our everyday lives, even to inform how insurers evaluate our health. The pervasive application of credit scoring has outpaced knowledge about why credit scores are such useful indicators of individual behavior. Here we test if the same factors that lead to poor credit scores also lead to poor health. Following the Dunedin (New Zealand) Longitudinal Study cohort of 1,037 study members, we examined the association between credit scores and cardiovascular disease risk and the underlying factors that account for this association. We find that credit scores are negatively correlated with cardiovascular disease risk. Variation in household income was not sufficient to account for this association. Rather, individual differences in human capital factors—educational attainment, cognitive ability, and self-control—predicted both credit scores and cardiovascular disease risk and accounted for ∼45% of the correlation between credit scores and cardiovascular disease risk. Tracing human capital factors back to their childhood antecedents revealed that the characteristic attitudes, behaviors, and competencies children develop in their first decade of life account for a significant portion (∼22%) of the link between credit scores and cardiovascular disease risk at midlife. We discuss the implications of these findings for policy debates about data privacy, financial literacy, and early childhood interventions
Early family adversity, stability and consistency of institutional care and infant cognitive, language and motor development across the first six months of institutionalization
This study extends research on the effects of institutionalization—by examining the trajectories of cognitive, language and motor development of 64 Portuguese infants and toddlers across the first six months of institutionalization, while determining whether pre-institutional adversities and the stability and consistency of institutional care predict children’s development. At time of enrollment, 23.4%, 32.8% and 31.3% of the children were moderately to severely delayed, respectively, in their cognitive, linguistic and motor functioning. Developmental problems persisted after six months of institutionalization. The accumulation of early pre-institutional adversities predicted cognitive and motor limitations at admission to the institutions, but not variation in subsequent development. The stability and consistency of institutional care also failed to predict developmental growth and change. Children who had never lived with their families of origin showed a better language development at enrollment than their counterparts who had lived with their families of origin before institutionalization. Such advantage was followed by a deceleration in language growth after six months of institutional placement. Results are discussed in terms of short- vs. longer-term effects of institutionalization.info:eu-repo/semantics/acceptedVersio
Using practice development methodology to develop children’s centre teams: Ideas for the future
The Children’s Centre Programme is a recent development in the UK and brings together
multi-agency teams to work with disadvantaged families. Practice development methods
enable teams to work together in new ways. Although the term practice development
remains relatively poorly defined, its key properties suggest that it embraces engagement,
empowerment, evaluation and evolution. This paper introduces the Children’s Centre
Programme and practice development methods and aims to discuss the relevance of using
this method to develop teams in children’s centres through considering the findings from an
evaluation of a two-year project to develop inter-agency public health teams.
The evaluation showed that practice development methods can enable successful team
development and showed that through effective facilitation, teams can change their practice to
focus on areas of local need. The team came up with their own process to develop a strategy
for their locality
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