A review of the bandwidth and environmental discourses of future energy scenarios:Shades of green and gray

Energy scenarios are often used to investigate various possible energy futures and reduce the uncertainty that surrounds energy transition. However, scenario construction lacks consistent and adequate methodological standards, resulting in limited insight into the actual bandwidth covered by current energy scenarios and whether various perspectives on future energy development pathways are all adequately represented. Our research deployed a non-mathematical clustering approach to identify general trends in future energy scenarios and assess the role of Cornucopian and Malthusian oriented world views therein. We found that the futures communicated in quantified future energy scenarios overlap to a large extent and represent only a narrow bandwidth of moderate world views. We argue that the underrepresentation of extreme representations of world views and environmental discourses in energy scenarios skews the overall outlook on possible energy futures. This implies that scenario-informed policy design and decision-making risks bias towards the status-quo. (C) 2016 Elsevier Ltd. All rights reserved

Ethnomathematical and Mathematical Connections Activated by a Teacher in Mathematical Problems Posing and Solving

Background: Connections are essential for understanding concepts, but difficulties have been evidenced in connecting representations and meanings of concepts and creating contextualised mathematical problems by teachers and students. Objective: Therefore, ethnomathematical and mathematical connections were analysed in a teacher's mathematical activity when posing and solving mathematical problems. Design: The methodology was qualitative-ethnographic, developed in a workshop done in stages. Setting and participants: An indigenous Mokaná teacher from Sibarco was selected. Data collection and analysis: Semi-structured interviews were conducted in the workshop, and the data were analysed based on the connections; the workshop was initially designed considering previous literature on the issue, and the researchers were familiarised with the teacher. Results: For the analysis of the mathematics used by the teacher in the classroom, we considered his sociocultural context, where he set problems about the area and perimeter of lots of land and enclosures. Then, the researchers presented the ethnomathematical connections that emerged in the elaboration and commercialisation of the pigeon peas sancocho, which was the basis for the teacher to pose and solve problems involving conversions between units of measurement, volume of the totumas (ellipsoid), etc. Simultaneously, mathematical connections of different representations, procedural, meaning, and modelling were identified. Finally, the researchers gave feedback by assessing the Acta Sci. (Canoas), 25(1), 86-121, Jan./Fev. 2023 87 potential of the mathematics known and explained by the teacher. Conclusion: This research provides input for teachers to pose and solve problems contextualised through connections

Balancing responsibilities:Effects of growth of variable renewable energy, storage, and undue grid interaction

Electrical energy storage is often proposed as a solution for the mismatch between supply patterns of variable renewable electricity sources and electricity demand patterns. However, effectiveness and usefulness of storage may vary under different circumstances. This study provides an abstract perspective on the merits of electrical energy storage integrated with decentralized supply systems consisting of solar PV and wind power in a mesolevel, residential sector context. We used a balancing model to couple demand and supply patterns based on Dutch weather data and assess the resultant loads given various scenarios. Our model results highlight differences in storage effectiveness for solar PV and wind power, and strong diminishing-returns effects. Small storage capacities can be functional in reducing surpluses in overdimensioned supply systems and shortages in under-dimensioned supply systems. However, full elimination of imbalance requires substantial storage capacities. The overall potential of storage to mitigate imbalance of variable renewable energy is limited. Integration of storage in local supply systems may have self-sufficiency and cost-effectiveness benefits for prosumers but may have additional peak load disadvantages for grid operators. Adequate policy measures beyond current curtailment strategies are required to ensure proper distribution of benefits and responsibilities associated with variable renewable energy and storage

Controlling crystal cleavage in Focused Ion Beam shaped specimens for surface spectroscopy

Our understanding of quantum materials is commonly based on precise determinations of their electronic spectrum by spectroscopic means, most notably angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy (STM). Both require atomically clean and flat crystal surfaces which traditionally are prepared by in-situ mechanical cleaving in ultrahigh vacuum chambers. We present a new approach that addresses three main issues of the current state-of-the-art methods: 1) Cleaving is a highly stochastic and thus inefficient process; 2) Fracture processes are governed by the bonds in a bulk crystal, and many materials and surfaces simply do not cleave; 3) The location of the cleave is random, preventing data collection at specified regions of interest. Our new workflow is based on Focused Ion Beam (FIB) machining of micro-stress lenses in which shape (rather than crystalline) anisotropy dictates the plane of cleavage, which can be placed at a specific target layer. As proof-of-principle we show ARPES results from micro-cleaves of Sr$_2$RuO$_4$ along the ac plane and from two surface orientations of SrTiO$_3$, a notoriously difficult to cleave cubic perovskite

The Incidence of Trilateral Retinoblastoma : A Systematic Review and Meta-Analysis

PURPOSE: To estimate the incidence of trilateral retinoblastoma in patients with retinoblastoma. " DESIGN: Systematic review and meta-analysis. METHODS: We searched Medline and Embase for scientific literature published between January 1966 and July 2015 that assessed trilateral retinoblastoma incidence. We used a random-effects model for the statistical analyses. " RESULTS: We included 23 retinoblastoma cohorts from 26 studies. For patients with bilateral retinoblastoma the unadjusted chance of developing trilateral retinoblastoma across all cohorts was 5.3% (95% confidence interval [CI]: 3.3%-7.7%); the chance of pineal trilateral retinoblastoma was 4.2% (95% CI: 2.6%-6.2%) and the chance of nonpineal trilateral retinoblastoma was 0.8% (95% CI: 0.4%-1.3%). In patients with hereditary retinoblastoma (all bilateral cases, and the unilateral cases with a family history or germline RB1 mutation) we found a trilateral retinoblastoma incidence of 4.1% (95% CI: 1.9%-7.1%) and a pineal trilateral retinoblastoma incidence of 3.7% (95% CI: 1.8%-6.2%). To reduce the risk of overestimation bias we restricted analysis to retinoblastoma cohorts with a minimum size of 100 patients, resulting in adjusted incidences of 3.8% (95% CI: 2.4%-5.4%), 2.9% (95% CI: 1.9%-4.2%), and 0.7% (95% CI: 0.3%-1.2%) for any, pineal, and nonpineal trilateral retinoblastoma, respectively, among patients with bilateral retinoblastoma. Among hereditary retinoblastoma we found an adjusted trilateral retinoblastoma incidence of 3.5% (95% CI: 1.2%-6.7%) and a pineal trilateral retinoblastoma incidence of 3.2% (95% CI: 1.4%-5.6%). CONCLUSION: The estimated incidence of trilateral retinoblastoma is lower than what is reported in previous literature, especially after exclusion of small cohorts that were subject to overestimation bias in this context. (C) 2015 by Elsevier Inc. All rights reserved.)Peer reviewe

Is there an association between wheezing and constipation in preschool children? Explanations from a longitudinal birth cohort

Objective: To assess whether wheezing and atopic dermatitis were associated with constipation in preschool children and to what extent shared risk factors contribute to this relationship. Methods: A population-based sample of 4651 preschool children was used. At the age of 24, 36 and 48 months, a parental report of functional constipation was available according to the Rome II criteria, and data on atopic dermatitis and wheezing were available using age-adapted questionnaires from the International Study of Asthma and Allergie