Оборудование для испытания листовых конструкционных материалов при двухосном растяжении. Сообщение 2. Испытания двухосным нагружением в плоскости листа

Рассмотрены конструктивные особенности оборудования для механических испытаний листовых конструкционных материалов в условиях двухосного статического, циклического и динамического нагружения. Предложены оригинальные решения проблем, связанных с проведением усталостных испытаний крестообразных образцов без применения сложных гидравлических систем и динамических испытаний с использованием простейших испытательных машин на одноосное растяжение-сжатие.Розглянуто конструктивні особливості устаткування для механічних випробувань листових конструкційних матеріалів в умовах двовісного статичного, циклічного та динамічного навантаження. Запропоновано оригінальні розв’язки ряду проблем, що пов’язані з використанням хрестоподібних зразків для випробувань на втому без застосування складних гідравлічних систем та для динамічних випробувань за допомогою найпростіших випробувальних машин на одновісний розтяг-стиск.Original methods of mechanical testing of sheet materials under conditions of biaxial static, cyclic, and dynamic loading are described. Solutions were suggested for a number of problems related to the use of cruciform specimens in fatigue tests without employment of complex hydraulic systems and in dynamic tests in uniaxial tension-compression using mechanical testing machines

Green school outdoor environments, greater equity? Assessing environmental justice in green spaces around Dutch primary schools

Green spaces around schools contribute to children's health and wellbeing. However, only a few studies have examined whether green space provision around schools in urban and rural areas are equally available across socioeconomic groups. We assessed whether and to what extent the green space provision of public primary schoolyards differs cross-sectionally across demographic and socioeconomic neighborhood profiles in the Netherlands. A fine-grained measure of green space (e.g., lawns, hedges, and trees) was applied to 5,773 school locations centering buffers at 50 m, 100 m, and 500 m. Fitting spatial lag regression models to the data, our results showed robust and inverse associations between available green school outdoor environments and low-income and less-educated neighborhoods. The percentage of non-Western migrants was positively associated. No evidence showed greenness around schools differing across levels of urbanization; however, schools with subsidy schemes supporting schoolyard greening tended to be greener. Our overall findings highlight socioeconomic disparities in green school outdoor environments across the Netherlands. To bridge this gap in environmental justice, we advocate for each child to have the ability to benefit equally from schoolyard green spaces by enabling more comprehensive greening subsidy schemes

Longitudinal associations between the neighborhood social, natural, and built environment and mental health: A systematic review with meta-analyses

This review aimed to assess the longitudinal associations between neighborhood social, natural, and built environments, and multiple mental health outcomes (i.e., depression, anxiety, common mental disorder, and pooled mental disorders). Of 6,785 records retrieved, 30 studies fulfilled the inclusion criteria. Meta-analytical results primarily obtained from developed country studies showed that composite neighborhood socioeconomic status was negatively associated with depression (p = 0.007) and pooled mental disorders (p = 0.002), while neighborhood urbanicity was positively associated with depression (p = 0.012) and pooled mental disorders (p = 0.005). Future longitudinal studies with similar designs and standardized exposure assessments are warranted

Second-order symmetric duality with cone constraints

AbstractWolfe and Mond–Weir type second-order symmetric duals are formulated and appropriate duality theorems are established under η-bonvexity/η-pseudobonvexity assumptions. This formulation removes several omissions in an earlier second-order primal dual pair introduced by Devi [Symmetric duality for nonlinear programming problems involving η-bonvex functions, European J. Oper. Res. 104 (1998) 615–621]

Об устойчивости движения математического маятника, взаимодействующего со струной

В линейной и нелинейной постановках решена задача об устойчивости стационарных движений однозвенного маятника в гибридной модели механической системы, состоящей из горизонтально закрепленной струны, нагруженной колеблющейся сосредоточенной массой.У лінійній і нелінійній постановках розв'язано задачу про стійкість стаціонарних рухів одноланкового маятника в гібридній моделі механічної системи, яка складається з горизонтально розміщеної струни, навантаженої коливною зосередженою масою.The problem of stability of the stationary motions of a single-mass pendulum in the hybrid model of one mechanical system is solved in the linear and nonlinear statements. The mechanical system consists of a string which is horizontally disposed and loaded by an oscillating localized mass

Neighborhood social and physical environment and general practitioner assessed morbidity

The aim of our study was to investigate the association between health enhancing and threatening, and social and physical aspects of the neighbourhood environment and general practitioner (GP) assessed morbidity of the people living there, in order to find out whether the effects of environmental characteristics add up or modify each other. We combined GP electronic health records with environmental data on neighbourhoods in the Netherlands. Cross-classified logistic multilevel models show the importance of taking into account several environmental characteristics and confounders, as social capital effects on the prevalence of morbidity disappear when other area characteristics are taken into account. Stratification by area socio-economic status, shows that the association between environmental characteristics and the prevalence of morbidity is stronger for people living in low SES areas. In low SES areas, green space seems to alleviate effects of air pollution on the prevalence of high blood pressure and diabetes, while the effects of green space and social capital reinforce each other

Inter- and intra-observer agreement of BI-RADS-based subjective visual estimation of amount of fibroglandular breast tissue with magnetic resonance imaging: comparison to automated quantitative assessment.

PURPOSE: To evaluate the inter-/intra-observer agreement of BI-RADS-based subjective visual estimation of the amount of fibroglandular tissue (FGT) with magnetic resonance imaging (MRI), and to investigate whether FGT assessment benefits from an automated, observer-independent, quantitative MRI measurement by comparing both approaches. MATERIALS AND METHODS: Eighty women with no imaging abnormalities (BI-RADS 1 and 2) were included in this institutional review board (IRB)-approved prospective study. All women underwent un-enhanced breast MRI. Four radiologists independently assessed FGT with MRI by subjective visual estimation according to BI-RADS. Automated observer-independent quantitative measurement of FGT with MRI was performed using a previously described measurement system. Inter-/intra-observer agreements of qualitative and quantitative FGT measurements were assessed using Cohen's kappa (k). RESULTS: Inexperienced readers achieved moderate inter-/intra-observer agreement and experienced readers a substantial inter- and perfect intra-observer agreement for subjective visual estimation of FGT. Practice and experience reduced observer-dependency. Automated observer-independent quantitative measurement of FGT was successfully performed and revealed only fair to moderate agreement (k = 0.209-0.497) with subjective visual estimations of FGT. CONCLUSION: Subjective visual estimation of FGT with MRI shows moderate intra-/inter-observer agreement, which can be improved by practice and experience. Automated observer-independent quantitative measurements of FGT are necessary to allow a standardized risk evaluation. KEY POINTS: • Subjective FGT estimation with MRI shows moderate intra-/inter-observer agreement in inexperienced readers. • Inter-observer agreement can be improved by practice and experience. • Automated observer-independent quantitative measurements can provide reliable and standardized assessment of FGT with MRI

Measurement of the Luminosity in the ZEUS Experiment at HERA II

The luminosity in the ZEUS detector was measured using photons from electron bremsstrahlung. In 2001 the HERA collider was upgraded for operation at higher luminosity. At the same time the luminosity-measuring system of the ZEUS experiment was modified to tackle the expected higher photon rate and synchrotron radiation. The existing lead-scintillator calorimeter was equipped with radiation hard scintillator tiles and shielded against synchrotron radiation. In addition, a magnetic spectrometer was installed to measure the luminosity independently using photons converted in the beam-pipe exit window. The redundancy provided a reliable and robust luminosity determination with a systematic uncertainty of 1.7%. The experimental setup, the techniques used for luminosity determination and the estimate of the systematic uncertainty are reported.Comment: 25 pages, 11 figure