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9. A Moduli Space of the Quaternionic Hopf Surface Encodes Standard Model Physics

Author

Hunter, Colin B.

Subjects
Mathematical Physics
Abstract

The quaternionic Hopf surface, HL, is associated with a non-compact moduli space, ML, of stable holomorphic SL(2,C) bundles. ML is open in MLc, the corresponding compact moduli space of holomorphic SL(2,C) bundles, and naturally fibers over an open set of the quaternionic projective line HP^1. We pull back to ML natural locally conformal kaehler and hyperkaehler structures from MLc, and lift natural sub-pseudoriemannian and optical structures from HP^1. Unexpectedly, the holomorphic maps connecting these structures solve the the classical Dirac-Higgs equations of the unbroken Standard Model. These equations include: all observed fermionic and bosonic fields of all three generations with the correct color, weak isospin, and hypercharge values; a Higgs field coupling left and right fermion fields; and a pp-wave gravitational metric. We hypothesize that physics is essentially the geometry of ML, both algebraic (quantum) and differential (classical). We further show that the Yang-Mills equations with fermionic currents also naturally emerge, along with an induced action on the ML structure sheaf equivalent to the time-evolution operator of the associated quantum field theory., Comment: 47 pages .pdf

Published
2012

29. The effect of axial–torsion coupling on the compressive collapse behavior of Kresling tubes.

Author

D'Mello, Royan, Hunter, Colin, Vijayachandran, Avinkrishnan Ambika, and Waas, Anthony

Subjects
*UNIT cell, *TORSIONAL load, *TUBES, *GEOMETRIC series, *ROTATIONAL motion, *FINITE element method, *PEAK load
Abstract

The coupled axial compressive and torsional response of thin-walled tubes, having Kresling geometric units in series, with hollow hexagonal cross-sections of similar wall thickness, is studied. The tubes are fabricated using multi-jet fusion technology with Polyamide-12 (PA12) material. Each tube is compressed under displacement-controlled quasi-static loading with roller boundary conditions to eliminate any reaction torque being induced in the tube. The tube's deformation response is characterized by an initial load rise followed by a drop in the load past a load maximum. This load drop is caused by localized collapse within a single Kresling unit. The collapse mechanism is accompanied by relative rotation between the ends of the Kresling unit, indicating the presence of compression-twist coupling. After local densification in the collapsed Kresling unit is attained, the load rises and attains a peak followed by a second load drop causing the other Kresling unit to collapse. Finite Element (FE) simulations show that the nonlinearity of the material response influences the onset of the collapse of the Kresling unit. Results from the present study will be helpful in tailoring the geometry of the Kresling unit cells to attain desired energy absorption or to "tune" the end-displacement vs. rotation response of the structure. • Thin-walled Kresling tubes studied under axial compression. • Axial–torsion coupling under compression depends on the Kresling unit geometry. • Past the linear region, the response has two regimes: load peaks and plateaus. • Finite element modeling explains salient features seen in the experiment. [ABSTRACT FROM AUTHOR]

Published
2024
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38. Home comfort and “peak household”:implications for energy demand

Author

Ellsworth-Krebs, Katherine, Reid, Louise, Hunter, Colin J., Ellsworth-Krebs, Katherine, Reid, Louise, and Hunter, Colin J.

Abstract

This paper draws on a study of Scottish householders living in “zero-carbon” homes. It explores how broader understandings of home comfort may explain changes that result in home life becoming increasingly energy demanding, despite householders’ intentions to save or decarbonize energy. The paper argues that domestic energy research must engage with the dreams, aspirations, and images of home that ultimately drive consumption and impact investment in housing and home energy improvements. This is done by examining the interrelationship between energy retrofitting and installing microgeneration technologies alongside discussing meanings of home comfort and visions of ideal homes with householders. The study argues that an important aspect of home improvements is due to accommodating the “needs” of the peak household. The paper concludes by discussing how a wider range of people and interventions could be pursued to reduce domestic energy demand such as promoting downsizing or working with home or lifestyle companies.

Published
2021

42. Phytotoxicity of surface water of the São Paulo Metropolitan Region using bioassay with Sinapis alba

Author

Kohatsu, Marcio Yukihiro, Jesus, Tatiane Araújo, Coelho, Lucia Helena Gomes, Peixoto, Damáris Cristina, Poccia, Geovana Tognella, and Hunter, Colin

Subjects
lcsh:GE1-350, lcsh:QH540-549.5, lcsh:Ecology, lcsh:Environmental sciences
Abstract

This research aimed to evaluate the phytotoxicity of surface waters of the São Paulo metropolitan region using bioassays based on Sinapis alba L. (mustard). Three sampling campaigns were carried out during the dry season of 2017 (minimum dilution of pollutants) and samples were collected in triplicate at two locations (Reference and Ribeirão Pires stream). The assays were performed in triplicate to increase the degree of reliability of the information obtained. The observed responses were: root growth of S. alba, relative percentage of germination, relative percentage of root growth, Germination Index (GI). Electrical conductivity and total dissolved solids were also measured in situ using a multiparametric probe. The reference samples were classified as non-phytotoxic (IG = 93.55 ± 0.17%), while Ribeirão Pires stream samples showed moderate phytotoxicity (IG = 70.88 ± 0.25%). Thus the discharge from the Ribeirão Pires stream into the billings dam poses a risk to the water quality of the dam, especially where this stream drains. Esta pesquisa teve por objetivo avaliar a fitotoxicidade de águas superficiais da Região Metropolitana de São Paulo utilizando bioensaios com Sinapis alba (sementes de mostarda), bem como a sua relação com a condutividade elétrica e sólidos dissolvidos totais. Foram realizadas 3 coletas no período de seca de 2017 (menor diluição de poluentes). As coletas foram realizadas em triplicata, em duas estações de amostragem (Referência e Córrego Ribeirão Pires). As variáveis respostas observadas foram: o crescimento radicular da S. alba, a porcentagem relativa de germinação, a porcentagem relativa de crescimento radicular, o Índice de Germinação (IG), além da aferição in locu da condutividade elétrica e dos sólidos dissolvidos totais, utilizando sonda multiparamétrica. As amostras da estação Referência foram classificadas como não fitotóxicas (IG = 93,55 ± 0,17%), enquanto as amostras do Córrego Ribeirão Pires apresentaram fitotoxicidade moderada (IG = 70,88 ± 0,25%). Desse modo, o despejo de águas residuárias no Córrego Ribeirão Pires oferece risco à manutenção da qualidade da água da Represa Billings, onde esse córrego deságua.

Published
2018

44. The measurement and prediction of conditions within indoor microenvironments

Author

Baker, Paul H., Galbraith, Graham H., McLean, R. Craig, Hunter, Colin, and Sanders, Chris H.

Subjects
Pollutants -- Research, Humidity -- Research, Construction and materials industries, Health, Research
Abstract

Abstract Biocontaminants, such as dust mites and microfungi, can live in building habitats with a spatial scale of only few millimetres. With the recent development of very small size microchip-based [...]

Published
2006

47. FoodFoto

Author

Regan, Mary, primary, Chung, Seon-Yoon, additional, Sofoluke, Tonia, additional, Rahmaty, Zahra, additional, Zhang, G. Man, additional, Zvenyach, Tracy, additional, Ryan, Alice S., additional, Storr, Carla L., additional, Johantgen, Mary, additional, and Hunter, Colin, additional

Published
2020
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