Ferroelectricity in the Magnetic E-Phase of Orthorhombic Perovskites

We show that the symmetry of the spin zigzag chain E phase of the orthorhombic perovskite manganites and nickelates allows for the existence of a finite ferroelectric polarization. The proposed microscopic mechanism is independent of spin-orbit coupling. We predict that the polarization induced by the E-type magnetic order can potentially be enhanced by up to two orders of magnitude with respect to that in the spiral magnetic phases of TbMnO3 and similar multiferroic compounds.Comment: 4 pages, 2 figures, somewhat changed emphases, accepted to PR

Persuasive technology for overcoming food cravings and improving snack choices

This research is partially supported by EPSRC Grant EP/G004560

Elastik Konsol Kirişlerin Büyük Deformasyon Analizi

Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2015Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2015Bu çalışma kapsamında elastik konsol bir kirişin statik analizi Euler-Bernoulli eşitlikleri kullanılarak yinelemeli bir yöntemle yapılmıştır. Bu amaçla kiriş eşit uzunlukta parçalara bölünmüş ve ötelenmelerin hesabında, bu parçalar üzerindeki dönmelerin doğrusal değiştiği kabulü yapılmıştır. Başlangıçta kirişe verilen yükün kirişte oluşturduğu şekil değiştirmeler belirlenmiş, şekil değiştirmiş kirişe tekrar aynı yükler etki ettirilerek şekil değiştirmeler doğrusal olmayan şekilde tekrar belirlenmiştir. Bu işlem şekil değiştirme sonuçları yeteri kadar birbirine yaklaştığında bitirilerek kirişin gerçek şekil değiştirmesi bulunmuştur. Yineleme işlemi Ms Excel programlarında yapılmıştır.In the context of this study, structural analysis of an elastic cantilever has been conducted using an iterative method based on Euler-Bernouilli equations. For this purpose, the beam has been considered to be divided into elements of equal length and the rotational angles have been assumed to be linearly changing over these elements in computing the elastic curve. At the beginning, the deformations caused by the loads acting on the structure is determined, and then by application of the loads on the deformed system, the new deflections are re-calculated. This procedure is repeated until stabilization of deflections and rotations. The iterative process has been conducted using MS Excel

Dönmeye Karşı Kontrol Altına Alınmış Basit Mesnetli Çubukların Stoke Dönüşümü Yardımıyla Burkulma Analizi

Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2015Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2015Bu çalışmada eksenel yüklenmiş basit mesnetli bir kirişin burkulma yüklerinin tespiti için yerel bir analitik yöntem geliştirilmiştir. Ayrıca kiriş uçlarından dönmeye karşı engelleyici yaylar ile sabitlenmiştir. Çalışmada Euler-Bernoulli kiriş teorisi kullanılmıştır. İlk olarak literatürde çok iyi bilinen Euler-Bernoulli kiriş teorisinin denklemi eksenel yükler altında verilmiştir. Analitik genel çözümlerin elde edilmesi için yer değiştirme fonksiyonu Fourier sinüs serisi seçilmiştir. Fourier sinüs serisinin seçilmesinin kirişin basit mesnetli olması ile bir ilgisi bulunmamaktadır. Literatürdeki çalışmalarda basit mesnetli kirişlerin sınır koşullarını sağladığı için genellikle Fourier sinus serileri kullanılmaktadır. Mesnetlerde dönmeye karşı yaylar kullanıldığı için; sınır koşullarında serbestlik sağlaması bakımından Stoke dönüşümü uygulanmıştır. Bu dönüşümün yapılmasının temel amacı yay sabitlerine verilecek değerlerde esneklik sağlamasıdır.This paper presents an analytical method for buckling analysis of simply supported beam with rotational restraints at both ends. Euler Bernoulli theory is used. The lateral displacement function is sellected by a Fourier sine series. Stokes’ transformation is applied to boundary conditions in order to construct the coefficient matrix. This application gives more flexibility for buckling analysis of beams with different boundary conditions. Comparisons are performed to validate present analytical method

Monolithic on-chip nonreciprocal photonics based on magneto-optical thin films

Monolithic integration of nonreciprocal optical devices on semiconductor substrates has been a long-sought goal of the photonics community. One promising route to achieve this goal is to deposit high quality magneto-optical (MO) oxide thin films directly on a semiconductor substrate. In this article, we will review our ongoing progress in material development and device engineering towards enabling a monolithically integrated, high-performance magneto-optical nonreciprocal photonics platform. In particular, we will discuss our recent work which has led to a new pulsed laser deposition (PLD) technique of Ce or Bi substituted yttrium iron garnet (YIG) thin films with reduced thermal budget, simplified growth protocols and improved magneto-optical characteristics. These materials were incorporated in monolithic resonator and interferometer based isolator devices to demonstrate on-chip optical isolation with improved device figure of merit. Challenges and opportunities for monolithic magneto-optical devices will be discussed in the context of our latest material and device performance metrics

Recommendations for the management of MPS IVA: systematic evidence- and consensus-based guidance.

IntroductionMucopolysaccharidosis (MPS) IVA or Morquio A syndrome is an autosomal recessive lysosomal storage disorder (LSD) caused by deficiency of the N-acetylgalactosamine-6-sulfatase (GALNS) enzyme, which impairs lysosomal degradation of keratan sulphate and chondroitin-6-sulphate. The multiple clinical manifestations of MPS IVA present numerous challenges for management and necessitate the need for individualised treatment. Although treatment guidelines are available, the methodology used to develop this guidance has come under increased scrutiny. This programme was conducted to provide evidence-based, expert-agreed recommendations to optimise management of MPS IVA.MethodsTwenty six international healthcare professionals across multiple disciplines, with expertise in managing MPS IVA, and three patient advocates formed the Steering Committee (SC) and contributed to the development of this guidance. Representatives from six Patient Advocacy Groups (PAGs) were interviewed to gain insights on patient perspectives. A modified-Delphi methodology was used to demonstrate consensus among a wider group of healthcare professionals with experience managing patients with MPS IVA and the manuscript was evaluated against the validated Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument by three independent reviewers.ResultsA total of 87 guidance statements were developed covering five domains: (1) general management principles; (2) recommended routine monitoring and assessments; (3) disease-modifying interventions (enzyme replacement therapy [ERT] and haematopoietic stem cell transplantation [HSCT]); (4) interventions to support respiratory and sleep disorders; (5) anaesthetics and surgical interventions (including spinal, limb, ophthalmic, cardio-thoracic and ear-nose-throat [ENT] surgeries). Consensus was reached on all statements after two rounds of voting. The overall guideline AGREE II assessment score obtained for the development of the guidance was 5.3/7 (where 1 represents the lowest quality and 7 represents the highest quality of guidance).ConclusionThis manuscript provides evidence- and consensus-based recommendations for the management of patients with MPS IVA and is for use by healthcare professionals that manage the holistic care of patients with the intention to improve clinical- and patient-reported outcomes and enhance patient quality of life. It is recognised that the guidance provided represents a point in time and further research is required to address current knowledge and evidence gaps

The state of the art development of AHP (1979-2017): A literature review with a social network analysis

Although many papers describe the evolution of the analytic hierarchy process (AHP), most adopt a subjective approach. This paper examines the pattern of development of the AHP research field using social network analysis and scientometrics, and identifies its intellectual structure. The objectives are: (i) to trace the pattern of development of AHP research; (ii) to identify the patterns of collaboration among authors; (iii) to identify the most important papers underpinning the development of AHP; and (iv) to discover recent areas of interest. We analyse two types of networks: social networks, that is, co-authorship networks, and cognitive mapping or the network of disciplines affected by AHP. Our analyses are based on 8441 papers published between 1979 and 2017, retrieved from the ISI Web of Science database. To provide a longitudinal perspective on the pattern of evolution of AHP, we analyse these two types of networks during the three periods 1979?1990, 1991?2001 and 2002?2017. We provide some basic statistics on AHP journals and researchers, review the main topics and applications of integrated AHPs and provide direction for future research by highlighting some open questions

Optical and magneto-optical behavior of Cerium Yttrium Iron Garnet thin films at wavelengths of 200–1770 nm

Magneto-optical cerium-substituted yttrium iron garnet (Ce:YIG) thin films display Faraday and Kerr rotation (rotation of light polarisation upon transmission and reflection, respectively) as well as a nonreciprocal phase shift due to their non-zero off-diagonal permittivity tensor elements, and also possess low optical absorption in the near-infrared. These properties make Ce:YIG useful in providing nonreciprocal light propagation in integrated photonic circuits, which is essential for accomplishing energy-efficient photonic computation and data transport architectures. In this study, 80 nm-thick Ce:YIG films were grown on Gadolinium Gallium Garnet substrates with (100), (110) and (111) orientations using pulsed laser deposition. The films had bulk-like structural and magnetic quality. Faraday and Kerr spectroscopies along with spectroscopic ellipsometry were used to deduce the complete permittivity tensor of the films in the ultraviolet, visible and near-infrared spectral region, and the magneto-optical figure of merit as a function of wavelength was determined. The samples showed the highest IR Faraday rotation reported for thin films of Ce:YIG, which indicates the importance of this material in development of nonreciprocal photonic devices.National Science Foundation (U.S.)Semiconductor Research Corporation. Function Accelerated nanoMaterial Engineerin

Dynamics of the chiral phase transition from AdS/CFT duality

We use Lorentzian signature AdS/CFT duality to study a first order phase transition in strongly coupled gauge theories which is akin to the chiral phase transition in QCD. We discuss the relation between the latent heat and the energy (suitably defined) of the component of a D-brane which lies behind the horizon at the critical temperature. A numerical simulation of a dynamical phase transition in an expanding, cooling Quark-Gluon plasma produced in a relativistic collision is carried out.Comment: 30 pages, 5 figure

Length Scale of the Spin Seebeck Effect

We investigate the origin of the spin Seebeck effect in yttrium iron garnet (YIG) samples for film thicknesses from 20 nm to 50  μm at room temperature and 50 K. Our results reveal a characteristic increase of the longitudinal spin Seebeck effect amplitude with the thickness of the insulating ferrimagnetic YIG, which levels off at a critical thickness that increases with decreasing temperature. The observed behavior cannot be explained as an interface effect or by variations of the material parameters. Comparison to numerical simulations of thermal magnonic spin currents yields qualitative agreement for the thickness dependence resulting from the finite magnon propagation length. This allows us to trace the origin of the observed signals to genuine bulk magnonic spin currents due to the spin Seebeck effect ruling out an interface origin and allowing us to gauge the reach of thermally excited magnons in this system for different temperatures. At low temperature, even quantitative agreement with the simulations is found.United States. Dept. of Energy. Office of Science (Solid-State Solar-Thermal Energy Conversion Center Grant DE-SC0001299)National Science Foundation (U.S.) (Award ECCS1231392