A case study of senior students\u27 perceptions of factors that shape aspirations in one low-income rural Iowa high school

Rural Iowa high school graduates from districts enrolling fewer than 600 students are more likely than their more urban peers to be economically disadvantaged as measured by eligibility for free and reduced cost meals. They are also less likely to aspire to high levels of educational attainment. Over the last decade, the percentage of graduates from small, rural schools intending to pursue any postsecondary education or training has approached or exceeded the percentage in more urban districts. However, among rural graduates with postsecondary intentions, the ranks of those students planning to pursue a four-year degree or higher remain disproportionately thin. This case study of seniors in one predominantly low-income rural Iowa district employed focus groups to gather seniors\u27 perceptions regarding factors that influence their aspirations. Group and individual interviews conducted with parents and school personnel provided additional insights. The results illuminate the important role of rural culture and context in shaping students\u27 sense of possibility and their plans for the future as well as ways in which rural values of place and connectedness collide with the national agenda of developing a competitive workforce ready for a global marketplace. The findings suggest that participants: (a) value hard work, independence, responsibility, and relationships; (b) view education primarily as a means to becoming credentialed; (c) feel little pressure to pursue four year college degrees but believe their parents are supportive of at least some postsecondary education; (d) are not knowledgeable about choosing, gaining entrance to, and paying for a postsecondary option suited to their needs and interests; (e) rely heavily on college admissions counselors as the most important source for information about college selection and financial aid; (f) find their parents to be the most important source of support in considering their postsecondary options; and (g) have been offered few planned experiences at school designed to help them explore postsecondary options and understand the processes related to college selection, admissions, and financial aid. Recommendations for additional research include comparative case studies of seniors in urban and rural settings and studies that would follow rural students throughout their senior year exploring how their perceptions change over time

We Must Provide a Family, Not Rebuild Orphanages: The Consequences of Russias Invasion of Ukraine for Children in Ukrainian Residential Institutions

This report documents risks to children from institutions in areas directly affected by the conflict as well as those evacuated to other areas of Ukraine or to European countries. According to government figures, Ukraine had more than 105,000 children in institutions before Russia's full-scale invasion in February 2022, the largest number in Europe. Nearly half were children with disabilities, according to UNICEF. Russia bears responsibility for the crisis facing these children, but the war adds to the urgency for Ukraine, with support from foreign governments and humanitarian agencies, to stop institutionalizing children and expand family- and community-based care

Control vector parameterization with sensitivity based refinement applied to baking optimization

In bakery production, product quality attributes as crispness, brownness, crumb and water content are developed by the transformations that occur during baking and which are initiated by heating. A quality driven procedure requires process optimization to improve bakery production and to find operational procedures for new products. Control vector parameterization (CVP) is an effective method for the optimization procedure. However, for accurate optimization with a large number of parameters CVP optimization takes a long computation time. In this work, an improved method for direct dynamic optimization using CVP is presented. The method uses a sensitivity based step size refinement for the selection of control input parameters. The optimization starts with a coarse discretization level for the control input in time. In successive iterations the step size was refined for the parameters for which the performance index has a sensitivity value above a threshold value.With this selection, optimization is continued for a selected group of input parameters while the other nonsensitive parameters (below threshold) are kept constant. Increasing the threshold value lowers the computation time, however the obtained performance index becomes less. A threshold value in the range of 10–20% of the mean sensitivity satisfies well. The method gives a better solution for a lower computation effort than single run optimization with a large number of parameters or refinement procedures without selection

The Use of Deconstructed Tires as Elastic Elements in Railway Tracks

Elastic elements such as rail pads, under sleeper pads and under ballast mats are railway components that allow for a reduction in track deterioration and vibrations. And they are furthermore commonly used to obtain an optimal vertical stiffness of the infrastructure. However, the use of elastomeric materials can increase construction costs and the consumption of raw materials. Thus, the utilization of used tire layers offers an alternative to reuse an abundant waste reducing the cost of elastic elements. In addition, an innovator technique allows deconstructing tire layers without grinding up the material, reducing production costs at the same time that tire properties are remained. This research is focused on the study of the viability of developing elastic components from used tire layers by evaluating the influence of thickness, the resistance capacity of the elements and their behavior in a ballast box. Results indicate the ability of tire pads to manufacture elastic elements (rail pads, under sleeper pads and under ballast mats) to be used in railway tracks.Authors want to thank to the Ministry of Economy and Competitiveness of Spain for the support received to develop the project entitled ―Design of used tire pads to be utilized as anti-vibration systems in railway tracks‖, IPT-2011-1963-310000

Shakedown for slab track substructures with stiffness variation

In this paper, shakedown analyses are carried out to predict the long-term response of slab track substructures under repeated moving train loads. The train loads are converted into a distributed moving load on the substructure surface by using a simplified track analysis. Based on Melan’s static shakedown theorem, a well-established shakedown analysis method is extended to determine shakedown limits of the slab track substructures. The influence of a linearly increasing stiffness modulus on the shakedown limits is considered by conducting finite- element analysis with a user-defined material. It is found that a rise in stiffness modulus or stiffness variation ratio can either increase or decrease the shakedown limit, depending on the competitive effects of the two mechanisms. Furthermore, the subgrade thickness determines the dominant mechanism

Toughness of Railroad Concrete Crossties with Holes and Web Openings

Prestressed concrete sleepers (or railroad ties) are principally designed in order to carry wheel loads from the rails to the ground of railway tracks, as well as to secure rail gauge for safe train travels. Their design takes into account static and dynamic loading conditions. In spite of prestressed concrete crossties being most commonly used in railway tracks, there have always been many demands from rail engineers to improve the serviceability and functionality of concrete crossties. For example, signaling, fiber optic, equipment cables are often damaged either by ballast corners or by the tamping machine. There has been a need to re-design concrete crossties to incorporate cables internally so that they would not experience detrimental or harsh environments. Also, many concrete crossties need a retrofit for an automatic train control device and similar signaling equipment. In contrast, the effects of holes and web openings on the structural capacity of concrete crossties have not been thoroughly investigated. This paper accordingly highlights the experimental investigations into the effect of holes and web openings on the toughness and ductility of concrete crossties. The key outcome of this research is to enable a better decision making process for retrofitting prestressed concrete crossties with holes and web openings in practice

Analysis of the influence of under sleeper pads on the railway vehicle/track dynamic interaction in transition zones

[EN] Sharp changes in the vertical stiffness levels of a track can increase train and infrastructure deterioration to the point where there is a serious risk of a derailment. Major overloading and unloading forces are created between the different track and vehicle components. This phenomenon has grown in importance as the operational speeds of trains have increased with the expansion of high-speed lines. In order to solve this problem a method has to be found to smooth the changes in vertical stiffness levels along the track. In the present paper, the combination of transition regions and under- sleeper pads (USPs) has been studied. The research has been performed by means of a dynamic vehicle-track interaction model created by synthesizing a series of sub-models of individual effects. The analysed variables allow various track configurations, train travelling speeds and the stiffness of the USPs to be investigated. The obtained results show that combining transition zones with USPs pads allows more homogeneous vertical stiffness levels to be achieved along the tracks which results in improved dynamic behaviour of the vehicle-track system. © IMechE 2011.This work was supported by Ineco-Tifsa.Insa Franco, R.; Salvador Zuriaga, P.; Inarejos Mesa, J.; Roda Buch, A. (2012). Analysis of the influence of under sleeper pads on the railway vehicle/track dynamic interaction in transition zones. Proceedings of the Institution of Mechanical Engineers Part F Journal of Rail and Rapid Transit. 226(4):409-420. doi:10.1177/0954409711430174S409420226

Effectiveness of resilient wheels in reducing noise and vibrations

This study focuses on the effectiveness of resilient wheels in reducing railway noise and vibrations, and compares the effectiveness of three types of wheels. The finite elements method has been used to characterise the vibratory behaviour of these wheels. The model has been excited with a realistic spectrum of vertical track irregularities, and a spectral analysis has been carried out. Results have been post-processed in order to estimate the sound power emitted. These calculations have been used to assess the effectiveness of the resilient wheel designs in reducing noise emitted to the environment and in propagating structural vibrations

Evaluation of Scenarios for Improving the Collection System for a Milk Factory in Ethiopia

The milk for a factory in Sululta (Ethiopia) is currently collected at ambient temperature. To increase milk production, the sourcing must be extended. This requires the collection of not only the morning milk but also the evening milk from smallholder farms. To accomplish this, the collection of milk from small farmers has to be improved, whereby the milk quality has to be assured with reasonable cost and environmental impact. A model predicting milk rejection was developed based on initial contamination and time and temperature profiles. With this model, different cooling scenarios we reevaluated regarding the expected effectiveness of reducing the rejection rate during collection. Second, cost estimations were made to implement the scenarios to collect morning and evening milk from smallholder farms. A third criterion was greenhouse gas (GHG) emissions per litre of collected milk. Finally, the feasibility of the scenarios was assessed in terms of technical, practical, and economic aspects. Including both quality and economics, the best scenario can be expected from a cooling centre where farmers bring their milk twice a day, except there are signals that the farmers would not be willing to deliver the evening milk to the centre at night. In that case, an additional collecting system would be needed to increase the milk supply. This would result in higher collection costs and an increased risk of milk rejection at the factory gate. Furthermore, this would reduce the value of the chilling centre, as in that case it would be better to deliver the milk directly to the factory. Both scenarios would increase GHG emissions compared with the current situation. Only the use of an off-grid solar power-driven cooling system at the farms would reduce the GHG emissions. However, this solution is less feasible economically. The applied combination of a simple model, economic analysis and the effect on GHG emissions gives valuable information on the effectiveness and limitations of different cooling scenarios for the milk factory. It can help to successfully apply a scenario for increasing the milk supply