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The suitability of fermenter liquor from MSW as an electron donor for hypersaline sulfate reduction
Full text linkLiquor from the fermentation of the organic fraction of municipal solid waste (OFMSW) was tested as a carbon source for sulfate reducing organisms under saline to hypersaline conditions for treating acid mine drainage in arid climates. Two 1.4 L reactors were operated continuously, one as a control maintained at a salinity of 20 g NaCl/L, the other (the test reactor) operated at salinities up to 50 g NaCl/L. Both reactors were first fed a synthetic mix of VFAs (acetate, propionate, butyrate, and valerate) at a COD ratio of 2:1:3:0.5 and at an organic loading rate of 1.56 gCOD/L/d with sulfate supplied in excess as Na2SO4. The sulfate reduction rate (SRR) was unaffected by the salinity up to 35 g NaCl/L, but was adversely affected in hypersaline (>35 g NaCl/L) conditions. The stabilized SRR at 50 g NaCl/L was 0.43 ± 0.01 g SO4-S/L/d compared to 0.66 ± 0.01 g SO4-S/L/d in the control reactor. Upon replacing the VFA mixture in both reactors with fermenter liquor (a mixture of alcohols, VFAs, lactate and succinate and 29 ± 4 % of unidentified COD), at the same COD loading rate, the SRR recovered in the test reactor (50 g NaCl/L) to 0.56 ± 0.01 g SO4-S/L/d with full utilisation of acetate by completely oxidizing sulfate reducers, no methane production and over 65 % utilisation of the un-identified COD fraction.</p
Direct connection between secondary relaxation mode and fracture toughness in alkali-aluminosilicate glasses
No full textOxide glasses are intrinsically brittle, lacking sufficient atomic-scale mechanisms that can relax mechanical stresses in the vicinity of a propagating crack. As a result, fracture is typically well-captured by considering local bond rupture at the crack tip. Here we demonstrate that barrier energies related to the low-temperature γ-relaxation mode in alkali-aluminosilicate glasses are inversely related to the fracture toughness measured via standardized three-point bending fracture experiments. This holds true for both a series with varying cations (Li, Na, K) and one with varying Li concentration. The structural rationale for this finding is gained via Raman spectroscopy. The findings suggest that a fundamental structural relaxation mode measured on bulk specimens can serve as an effective guideline for fracture toughness of oxide glasses. Data for additional silicate glasses support this conclusion.</p
Zombie or cyborg?:Exploring how communities can improve the interplay between agile and hierarchical organizing
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Harness First-Principles Thinking in Problem-Based Learning for Chemical Education
No full textIn philosophy and science, a first principle is a basic proposition or assumption that cannot be deduced from any other proposition or assumption. Ancient Greek philosophy Aristotle defined the first principle as “the first basis from which a thing is known.” First-principles thinking (or reasoning from first-principles) is a way of thinking and problem-solving that breaks down a complex problem into its most basic assumptions, facts, concepts, or ideas and then reassembles them from the bottom-up. In this paper, we reported our attempts to harness first-principles thinking into problem-based learning (PBL) in chemistry education. Two PBL projects were elaborately designed for two student groups. By utilizing the inquiry-based technique and jigsaw technique, understanding of the fundamental principles of chemistry was employed to guide the student research activity and strengthen the learning of chemistry. We also observed signs of increased creativity during the process. This communication indicated that first-principles thinking could be harnessed to increase studentlearning depth and promote creativity in chemical education.</p
How local is decentral politics? Variations in the supply of municipal policies
No full textLocal democracy is theoretically based on political parties offering different policies across and within sub-national geographical units. However, local democracy is embedded within a multilevel party and institutional structure that may compromise this endeavour. This study develops three expectations of policy variation: within party variation in political positions across geographical units; differences in policy positions across parties within geographical units; and that parties adjust their supply of policy over time possibly based on structural, social, or party features. It is argued that the presence of these variations is important for local democracy considering multilevel party institutions and their existence is tested using 1,002 Danish municipal party election manifestos from the local elections in 2013 and 2017, covering all 98 Danish municipalities. The first two types of variation are clearly present, the third is only present between parties, and this suggests that local politics is at least somewhat local.</p
A review on optimization of district energy systems
No full textThe scientific state-of-the-art indicates that solutions for integrating renewable energy in the energy sector have primarily been sought within the limits of individual energy sub-sectors, focusing on concepts such as 'Smart Grid', 'Zero Energy Buildings', and 'Power-to-Heat', while the heating and cooling sectors have largely been overlooked so far. The heating and cooling sector should undergo a transformation in response to sustainability concerns and greenhouse gas emissions. District energy systems (DES) are expected to play an essential role in the development of climate-neutral societies. However, due to its large scale and its potential integration to a number of other energy systems, DES introduces complexity in design and operation, necessitating optimization studies to achieve key objectives such as reducing operational and infrastructure costs, minimizing emissions, and enhancing efficiency. This review addresses a gap in current research on DES optimization by exploring the technical aspects behind DES optimization and their practical applications. The review begins by outlining the state-of-the-art of DES and their evolution. Following this, the review examines the technical foundations of DES optimization studies in the literature. Moreover, the review outlines the critical components of DES optimization, including problem formulation and algorithms used to find efficient solutions. Additionally, key areas for future research and development in DES optimization are identified.</p
Eavesdropping Across the Atlantic
No full textThis article discusses theoretical concerns related to consuming and studying U.S. American texts in a European setting. Connecting ideas from intellectual historian Quentin Skinner and literary scholar Rita Felski, the article explores how research on and the teaching of American narrative texts like literature, film, and television series are deeply affected by how much re-searchers or teachers emphasize their American otherness. The article argues that the metaphor of eavesdropping can be an appropriate way of understanding how Europeans and people from other parts of the world may (choose to) be affected and inspired by the texts from the U.S. (spatial otherness) or the past (temporal otherness) even though we were never intended to tune in on these spatially or temporally foreign conversations they were a part of. The article connects this line of inquiry to how American studies teaching (and the teaching of American topics in English programs) can adopt specific notions of contextualization in order to ruminate on how texts from foreign cultures can affect us even though they are always originally embedded in contexts that are not our own.This article discusses theoretical concerns related to consuming and study-ing American texts in a European setting. Connecting ideas from intellectu-al historian Quentin Skinner and literary scholar Rita Felski, the article ex-plores how research on and the teaching of American narrative texts like literature, film, and television series is deeply affected by how much we as teachers emphasize their American otherness. The article argues that the metaphor of eavesdropping can be an appropriate way of understanding how Europeans and people from other parts of the world may (choose to) be affected and inspired by the texts from the U.S. (spatial otherness) or the past (temporal otherness) even though we were never intended to tune in on these spatially or temporally foreign conversations they were a part of. The article connects this line of inquiry to how American Studies teaching (and the teaching of American topics in English programs) can adopt specific no-tions of contextualization in order to ruminate on how texts from foreign cultures can affect us even though they are always originally embedded in contexts that are not our own
Using artificial neural networks for anomaly detection in infrared thermography images for rapid diagnosis in an emergency care unit
Full text linkInfrared thermography (IRT) has emerged as an affordable, rapid and noninvasive complement to widely adopted yet resource-demanding medical imaging techniques such as MRI, CT scans and X-rays, offering diverse applications in the medical field. While IRT hardware is well established and capable of providing high-quality thermographic images, the analysis of such images often requires well-trained experts. Current state-of-the art methods for computer-aided IRT analysis rely on statistical tests of temperature gradients between control points, which are suboptimal because they do not fully exploit the available information regarding spatial temperature distributions. This paper addresses this issue by incorporating artificial neural networks (ANN) into the IRT analysis workflow. We focused on a particular case in which the IRT was utilized in the emergency department (ED) for predicting 30-day mortality, thereby contributing to improved diagnosis and patient care in emergency medicine. In total, the IRT images of 214 patients were analyzed. Various ANN-based approaches were considered in this study, and the best results were obtained using an anomaly detection model based on a variational autoencoder (VAE), which achieved promising results for detecting abnormal images. This paper comprehensively presents all the analysis details as well as recommendations regarding image preprocessing, augmentation, and potential enhancements of the models