Quantum Kagome antiferromagnet ZnCu3(OH)6Cl2

The frustration of antiferromagnetic interactions on the loosely connected kagome lattice associated to the enhancement of quantum fluctuations for S=1/2 spins was acknowledged long ago as a keypoint to stabilize novel ground states of magnetic matter. Only very recently, the model compound Herbersmithite, ZnCu3(OH)6Cl2, a structurally perfect kagome antiferromagnet, could be synthesized and enables a close comparison to theories. We review and classify various experimental results obtained over the past years and underline some of the pending issues.Comment: 23 pages, 16 figures, invited paper in J. Phys. Soc. Jpn, special topics issue on "Novel States of Matter Induced by Frustration", to be published in Jan. 201

Practising person-centred care. Selected abstracts from the virtual 26th WONCA Europe conference, 6-10 July 2021

BACKGROUND: From 6 to 10 July 2021, WONCA Europe and the Dutch College of General Practitioners as host organiser welcomed 1,266 family physicians/general practitioners, teachers, researchers, and students from 66 countries interested in sharing knowledge, experience and innovations in primary healthcare. METHODS: In cohesive sets of plenary presentations, round table sessions, and research masterclasses, aspects of patient care, research, and education around Practicing Person-Centred Care were presented and discussed. Actual topics in primary care such as covid-19, e-health and professional health, were covered in oral presentation sessions, one slide 5-minutes presentations, case presentations by young doctors and the e-poster gallery. All sessions were recorded and available on-demand for registrants until three months after the conference. All accepted abstracts have been published in the abstract book [https://www.woncaeurope.org/page/past-conference-abstract-books]. For this Journal, we selected the top 20 abstracts based on reviewers scores (mean of 3.5 or higher on a scale of 4) and consensus among members of the Scientific Committee. RESULTS: The selected abstracts are divided into the following themes: (1) clinical topics often encountered in primary care, such as acute chest pain, urinary tract infections, dementia, and covid-19 (N = 5); (2) personalised care and related issues such as addressing multimorbidity (N = 2); shared decision making and patient empowerment (N = 4); (3) overdiagnosis and overtreatment, focusing on deprescribing (N = 2); (4) health promotion and prevention, including mental health (N = 2); (5) quality and safety (N = 2); (6) professional development and education (N = 1); (7) research and innovation, including teleconsultation (N = 2)

Scanning SQUID Susceptometry of a paramagnetic superconductor

Scanning SQUID susceptometry images the local magnetization and susceptibility of a sample. By accurately modeling the SQUID signal we can determine the physical properties such as the penetration depth and permeability of superconducting samples. We calculate the scanning SQUID susceptometry signal for a superconducting slab of arbitrary thickness with isotropic London penetration depth, on a non-superconducting substrate, where both slab and substrate can have a paramagnetic response that is linear in the applied field. We derive analytical approximations to our general expression in a number of limits. Using our results, we fit experimental susceptibility data as a function of the sample-sensor spacing for three samples: 1) delta-doped SrTiO3, which has a predominantly diamagnetic response, 2) a thin film of LaNiO3, which has a predominantly paramagnetic response, and 3) a two-dimensional electron layer (2-DEL) at a SrTiO3/AlAlO3 interface, which exhibits both types of response. These formulas will allow the determination of the concentrations of paramagnetic spins and superconducting carriers from fits to scanning SQUID susceptibility measurements.Comment: 11 pages, 13 figure

Hexagons become second if symmetry is broken

Pattern formation on the free surface of a magnetic fluid subjected to a magnetic field is investigated experimentally. By tilting the magnetic field the symmetry can be broken in a controllable manner. When increasing the amplitude of the tilted field, the flat surface gives way to liquid ridges. A further increase results in a hysteretic transition to a pattern of stretched hexagons. The instabilities are detected by means of a linear array of magnetic hall sensors and compared with theoretical predictions.Comment: accepted for publication by Physical Review E/Rapid Communicatio

Chiral magnetoresistance in Pt/Co/Pt zigzag wires

The Rashba effect leads to a chiral precession of the spins of moving electrons while the Dzyaloshinskii-Moriya interaction (DMI) generates preference towards a chiral profile of local spins. We predict that the exchange interaction between these two spin systems results in a 'chiral' magnetoresistance depending on the chirality of the local spin texture. We observe this magnetoresistance by measuring the domain wall (DW) resistance in a uniquely designed Pt/Co/Pt zigzag wire, and by changing the chirality of the DW with applying an in-plane magnetic field. A chirality-dependent DW resistance is found, and a quantitative analysis shows a good agreement with a theory based on the Rashba model. Moreover, the DW resistance measurement allows us to independently determine the strength of the Rashba effect and the DMI simultaneously, and the result implies a possible correlation between the Rashba effect, the DMI, and the symmetric Heisenberg exchange

Urban physics simulation for climate change adaptation of buildings and urban areas

This chapter discusses the simulation of urban thermal microclimate with a focus on heat waves in urban areas, the simulation of overheating of buildings and the effects of adaptation measures to limit temperatures in buildings and urban areas during heat waves. The spatial scales are the meteorological microscale (neighborhood scale) and the building scale; the methods are computational fluid dynamics and building energy simulation. Adaptation measures investigated at the neighborhood scale are avenue trees, green facades and green roofs; adaptation measures at the building scale are increased thermal resistance, increased thermal mass, increased short-wave reflectivity of facades and roofs, peak ventilation, vegetated roofs and exterior solar shading

Charge distribution and electroluminescence in cross-linked polyethylene under dc field

The intent of this paper is to cross-correlate the information obtained by space charge distribution analysis and electroluminescence (EL) detection in cross-linked polyethylene samples submitted to dc fields, with the objective to make a link between space charge phenomena and energy release as revealed by the detection of visible photons. Space charge measurements carried out at different field levels by the pulsed electro-acoustic method show the presence of a low-field threshold, close to 15-20 kV mm-1, above which considerable space charge begins to accumulate in the insulation. Charges are seen to cross the insulation thickness through a packet-like behaviour at higher fields, starting at about 60-70 kV mm-1. EL measurements show the existence of two distinct thresholds, one related to the continuous excitation of EL under voltage, the other being transient EL detected upon specimen short circuit. The former occurs at values of field corresponding to charge packet formation and the latter to the onset of space charge accumulation. The correspondence between pertinent values of the electric field obtained through space charge and EL analyses provides support for the existence of degradation thresholds in insulating materials. Special emphasis is given to the relationship between charge packet formation and propagation, and EL. Although the two phenomena are observed in the same field range, it is found that the onset of continuous EL follows the formation at the electrodes of positive and negative space charge regions that extend into the bulk prior to the propagation of charge packets. Charge recombination appears to be the excitation process of EL since oppositely charged domains meet in the material bulk. To gain an insight into specific light-excitation processes associated with charge packet propagation, EL has been recorded for several hours under fields at which charge packet dynamics were evidenced. It is shown that current and luminescence oscillations are detected during charge packet propagation, and that they are in phase. The mechanisms underlying EL and charge packets are further considered on the basis of these results

Design and Evaluation of English Oral Communication Course at Kansai University

Educators, linguists, and anthropologists recognize that language reflects societalvalues, culture, and attitudes of the country where the language is spoken. The use of　technology provides numerous　activities where students can learn about the values, culture, and lifestyles of people living in other countries while practicing their English communication skills. This paper examines the use of videoconferencing between students at Kansai University and the University of Hawaii to develop language skills and increaseintercultural understanding. The authors describe learning activities to prepare students for the videoconferences, examine learning styles related to the use of technology, provide observations about technology use, and discuss changes in students’ intercultural sensitivity over one semester