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"Fuchs, U"
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Carnot and the Archetype of Waterfalls
2024
Carnot treats Heat as a Force of Nature, with its typical fundamental characteristics of intensity and thermal tension (temperature and temperature difference), extension (amount of heat, i.e., caloric), and power. To suggest how the three aspects are related, he applies the imagery of waterfalls to causative thermal processes: heat powers motion in a heat engine just as falling water does when activating rotation in a water wheel. We understand Carnot’s waterfall imagery as an archetype of human reasoning—as an embodiment of how we experience and understand causative (agentive) phenomena. We project it onto the macroscopic phenomena identified in physical science and so unlock the power of analogical structure mapping between theories of fluids, electricity and magnetism, heat, substances, gravity, and linear and rotational motion. In particular, the notion of (motive) power of a waterfall lets us create imaginative explanations of the interactions of Forces of Nature and helps us construct a generalized energy principle. Two-hundred years after Carnot made us aware of it, his Waterfall Analogy is a powerful example of theory construction with roots deep in how we experience phenomena as caused by natural agents.
Journal Article
Entropy and the Experience of Heat
by
Fuchs, Hans
,
D’Anna, Michele
,
Corni, Federico
in
conceptualization
,
early history of thermal physics
,
Electric rates
2022
We discuss how to construct a direct and experientially natural path to entropy as a extensive quantity of a macroscopic theory of thermal systems and processes. The scientific aspects of this approach are based upon continuum thermodynamics. We ask what the roots of an experientially natural approach might be—to this end we investigate and describe in some detail (a) how humans experience and conceptualize an extensive thermal quantity (i.e., an amount of heat), and (b) how this concept evolved during the early development of the science of thermal phenomena (beginning with the Experimenters of the Accademia del Cimento and ending with Sadi Carnot). We show that a direct approach to entropy, as the extensive quantity of models of thermal systems and processes, is possible and how it can be applied to the teaching of thermodynamics for various audiences.
Journal Article
A Direct Entropic Approach to the Thermal Balance of Spontaneous Chemical Reactions
by
Corni, Federico
,
Fuchs, Hans U.
,
D’Anna, Michele
in
Chemical potential
,
Chemical reactions
,
Comparative analysis
2024
When working with, and learning about, the thermal balance of a chemical reaction, we need to consider two overlapping but conceptually distinct aspects: one relates to the process of reallocating entropy between reactants and products (because of different specific entropies of the new substances compared to those of the old), and the other to dissipative processes. Together, they determine how much entropy is exchanged between the chemicals and their environment (i.e., in heating and cooling). By making explicit use of (a) the two conjugate pairs chemical amount (i.e., amount of substance) and chemical potential, and entropy and temperature, respectively, (b) the laws of balance of amount of substance on the one hand and entropy on the other, and (c) a generalized approach to the energy principle, it is possible to create both imaginative and formal conceptual tools for modeling thermal balances associated with chemical transformations in general and exothermic and endothermic reactions in particular. In this paper, we outline the concepts and relations needed for a direct approach to chemical and thermal dynamics, create a model of exothermic and endothermic reactions, including numerical examples, and discuss how to relate the direct entropic approach to traditional models of these phenomena.
Journal Article
Young Children’s Ideas about Heat Transfer Phenomena
by
Pahl, Angelika
,
Corni, Federico
,
Fuchs, Hans U.
in
children
,
Cold
,
Elementary School Teachers
2022
In this article, we present kindergarten children’s ideas about thermal phenomena before any educational intervention took place. In order to capture and account for the heterogeneity of the kindergarten group in this study, first teachers observed children’s exploration behavior, task orientation, science interest, and language comprehension in everyday kindergarten life using a structured observation form. Then, 24 children aged between 3.8 and 6.0 years were interviewed individually about three situations focusing upon water temperature and its changes. The results show that interest in science and language comprehension are significantly related to children’s understanding of thermal phenomena, while task orientation and exploratory behavior are not. In general, the kindergarten children did not yet use the word “heat” in their descriptions and explanations but were more or less able to describe the water temperature and its changes in a differentiated way.
Journal Article
Embodied Simulations of Forces of Nature and the Role of Energy in Physical Systems
by
Pahl, Angelika
,
Corni, Federico
,
Fuchs, Hans U.
in
Chemistry
,
Cognitive Structures
,
Concept Formation
2021
We experience (perceive, act upon and react to, and conceptualize) dynamical processes in nature as agentive. Expressed differently, we experience events as resulting from activities and interactions of Forces of Nature (such as wind, light, heat, fluids, electricity, substances, and motion) that are conceived of as powerful agents acting and interacting in physical environments. An example would be sunlight creating heat in the Earth’s surface layers, and this heat using the atmosphere as a heat engine whose output are the winds on our planet. In the physics of dynamical systems, these forces are characterized in terms of intensive and extensive quantities (i.e., electric potential and electric charge in the case of electricity). The aspect of power is formalized with the help of a generalized energy principle and the rules relating power/energy to intensive and extensive physical quantities. Concrete processes depend upon properties of physical materials (in and through which forces are active) such as (thermal, electrical, etc.) capacity or conductivity. In this paper, we demonstrate how we can create Embodied Simulations and Forces-of-Nature Theater performances, where children act as forces such as water, heat, electricity, and motion. The embodied logic of the physical play teaches children about the logic of our explanations of physical processes.
Journal Article
Vitamin D supplementation and bone turnover in advanced heart failure: the EVITA trial
2018
SummaryLow vitamin D status is common in patients with heart failure and may influence bone health. A daily vitamin D dose of 4000 IU (moderately high dose) for 3 years had however no effect on parameters of bone metabolism, even in patients with very low vitamin D status.IntroductionLow vitamin D status is common in patients with heart failure (HF) and has been related to disturbed bone turnover. The present study investigated the effect of a daily vitamin D3 dose of 4000 IU on bone turnover markers (BTMs) in patients with advanced HF and 25-hydroxyvitamin D (25OHD) concentrations < 75 nmol/L.MethodsIn this pre-specified secondary analysis of a randomized controlled trial, we assessed in 158 male HF patients (vitamin D group: n = 80; placebo group: n = 78) between-group differences in calciotropic hormones (25OHD, 1,25-dihydroxyvitamin D [1,25(OH)2D], intact parathyroid hormone [iPTH]), and BTMs (cross-linked C-telopeptide of type I collagen, bone-specific alkaline phosphatase, undercarboxylated osteocalcin). Comparisons were performed at the end of a 3-year vitamin D supplementation period with adjustments for baseline values.ResultsCompared with placebo, vitamin D increased 25OHD on average by 54.3 nmol/L. At study termination, 25OHD and 1,25(OH)2D were significantly higher (P < 0.001 and P = 0.007, respectively), whereas iPTH tended to be lower in the vitamin D group than in the placebo group (P = 0.083). BTMs were initially within their reference ranges and did not differ significantly between groups at study termination, neither in the entire study cohort nor when data analysis was restricted to the subgroup of patients with initial 25OHD concentrations < 30 nmol/L (n = 54) or to patients with initial hyperparathyroidism (n = 65) (all P values > 0.05).ConclusionsA daily vitamin D3 dose of 4000 IU did not influence BTMs. Data indicate that vitamin D supplementation will not lower bone turnover in male patients with heart failure.
Journal Article
Randomized supplementation of 4000 IU vitamin D3 daily vs placebo on the prevalence of anemia in advanced heart failure: the EVITA trial
2017
Background
Low 25-hydroxyvitamin D (25OHD) levels (< 75 nmol/l) are inversely associated with anemia prevalence. Since anemia and low 25OHD levels are common in patients with heart failure (HF), we aimed to investigate whether vitamin D supplementation can reduce anemia prevalence in advanced HF.
Methods
EVITA (Effect of Vitamin D on Mortality in Heart Failure) is a randomized, placebo-controlled clinical trial in patients with initial 25OHD levels < 75 nmol/l. Participants received either 4000 IU vitamin D
3
daily or a matching placebo for 36 months. A total of 172 patients (vitamin D group:
n
= 85; placebo group:
n
= 87) were investigated in this pre-specified secondary data analysis. Hemoglobin (Hb) and other hematological parameters were measured at baseline and study termination. Assessment of between-group differences in anemia prevalence and Hb concentrations was performed at study termination, while adjusting for baseline differences.
Results
In the vitamin D and placebo group, baseline proportions of patients with anemia (Hb < 12.0 g/dL in females and < 13.0 g/dL in males) were 17.2% and 10.6%, respectively (
P
= 0.19). At study termination, the proportion of patients with anemia in the vitamin D and placebo groups was 32.2% and 31.8%, respectively (
P
> 0.99). There was no between-group difference in change in the Hb concentrations (− 0.04 g/dL [95%CI:-0.53 to 0.45 g/dL];
P
= 0.87). Results regarding anemia risk and Hb concentrations were similar in the subgroup of patients with chronic kidney disease (vitamin D group:
n
= 26; placebo group:
n
= 23). Moreover, results did not differ substantially when data analysis was restricted to patients with deficient baseline 25OHD levels.
Conclusions
A daily vitamin D supplement of 4000 IU did not reduce anemia prevalence in patients with advanced HF. Data challenge the clinical relevance of vitamin D supplementation to increase Hb levels.
Trial registration
The study was registered at EudraCT (No. 2010–020793-42) and
clinicaltrials.gov
(
NCT01326650
).
Journal Article
Interaction of Physical and Narrative Experiencing of Heat Transfer Phenomena by Kindergarten Children
2025
We investigate the interaction of physical and narrative forms of experiencing in the construction of concepts by young children in their early encounters with thermal phenomena. 24 children, aged between 4.6 and 6.6 years, were involved in both types of experience: first the physical one, consisting in heating of water by immersion of hot stones, then the narrative one, the listening of an illustrated story told by the teacher. We will present the outcomes of a qualitative investigation aimed at observing the conceptual development of the children by analysing their language in individual interviews performed before and after the intervention. The results in the post-test show that the children improved in their ability to describe the thermal phenomena they observed and developed a better understanding of the processes involved compared to the pre-test.
Journal Article
Daily Supplementation with 4000 IU Vitamin D3 for Three Years Does Not Modify Cardiovascular Risk Markers in Patients with Advanced Heart Failure
by
Prokop, Sylvana
,
Fuchs, Uwe
,
Ernst, Jana B.
in
25-Hydroxyvitamin D
,
alpha-2-HS-Glycoprotein - analysis
,
Anticholesteremic agents
2019
Background/Aims: We aimed to investigate the effect of a moderately high vitamin D dose on lipid parameters and biochemical markers of vascular calcification (VC) in patients with established cardiovascular disease. Methods: We included in this pre-specified secondary analysis of a randomized controlled trial 161 patients with advanced heart failure and 25-hydroxyvitamin D (25OHD) concentrations < 75 nmol/L (vitamin D group: n = 80; placebo group: n = 81), who received a daily vitamin D 3 supplement of 4,000 IU for 3 years. We assessed between-group differences of the lipid parameters total-cholesterol, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, and triglycerides, and the VC markers fetuin-A and non-phosphorylated undercarboxylated matrix gla protein (MGP) at study termination, with adjustment for baseline values. Results: Lipid parameters, the percentage of patients with dyslipoproteinemia, and VC markers did not differ significantly between groups at study termination (p values: 0.395–0.939). Likewise, vitamin D achieved no significant treatment effect on these markers in subgroup analyses in patients with 25OHD concentrations < 30 nmol/L, nonusers of lipid-lowering drugs, or diabetic patients (p values: 0.245–0.998). Conclusion: Our data indicate that vitamin D does not improve the lipid profile and does not influence the calcification inhibitors fetuin-A and non-phosphorylated undercarboxylated MGP in patients with advanced heart failure.
Journal Article
Primary Physical Science for Student Teachers at Kindergarten and Primary School Levels: Part I—Foundations of an Imaginative Approach to Physical Science
2020
This is a theoretical paper in which we describe the motivation for and the design of a novel primary physics course for student teachers at kindergarten and primary school levels that uses cognitive tools such as metaphor, analogy, and narrative. The course has been taught in the master’s program in teacher education at three Universities over the last 5 years. It is based upon a model of the experience of forces of nature that draws upon four existing frameworks in physics, narratology, cognitive linguistics, and a theory of the development of cognitive tools. In short, the course is created upon the foundations of an imaginative, metaphoric and narrative, approach to physical science in general and to forces of nature in particular. Student teachers who learn science based upon this model can more directly relate to how children themselves experience nature and become confident narrators of stories of forces of nature. We describe the notion of Force of Nature (“The Gestalt of Force of Nature”) and explain what we mean by cognitive tools (“Cognitive Tools: Tools of Imagination”) before showing in what sense modern macroscopic physics is both metaphoric and narrative at its core (“An Imaginative Approach to Physical Science”). In “A Systemic Imaginative Approach to Primary Physics”, we give an outline of what is needed in order to apply the approach to a course for primary physics for student teachers. In the final section, we will discuss some questions and challenges raised by this approach and show that it is a viable avenue to bringing together science and the humanities, both for research and for teaching.
Journal Article