Reduction of Dilute Ising Spin Glasses

The recently proposed reduction method for diluted spin glasses is investigated in depth. In particular, the Edwards-Anderson model with \pm J and Gaussian bond disorder on hyper-cubic lattices in d=2, 3, and 4 is studied for a range of bond dilutions. The results demonstrate the effectiveness of using bond dilution to elucidate low-temperature properties of Ising spin glasses, and provide a starting point to enhance the methods used in reduction. Based on that, a greedy heuristic call ``Dominant Bond Reduction'' is introduced and explored.Comment: 10 pages, revtex, final version, find related material at http://www.physics.emory.edu/faculty/boettcher

Relaxational behavior of the infinite-range Ising spin-glass in a transverse field

We study the zero-temperature behavior of the infinite-ranged Ising spin glass in a transverse field. Using spin summation techniques and Monte Carlo methods we characterize the zero-temperature quantum transition. Our results are well compatible with a value $\nu=\frac{1}{4}$ for the correlation length exponent, $z=4$ for the dynamical exponent and an algebraic decay $t^{-1}$ for the imaginary-time correlation function. The zero-temperature relaxation of the energy in the presence of the transverse field shows that the system monotonically reaches the ground state energy due to tunneling processes and displays strong glassy effects.Comment: 15 pages + 5 Figures, Revte

A new quark-hadron hybrid equation of state for astrophysics - I. High-mass twin compact stars

Aims: We present a new microscopic hadron-quark hybrid equation of state model for astrophysical applications, from which compact hybrid star configurations are constructed. These are composed of a quark core and a hadronic shell with a first-order phase transition at their interface. The resulting mass-radius relations are in accordance with the latest astrophysical constraints. Methods: The quark matter description is based on a quantum chromodynamics (QCD) motivated chiral approach with higher-order quark interactions in the Dirac scalar and vector coupling channels. For hadronic matter we select a relativistic mean-field equation of state with density-dependent couplings. Since the nucleons are treated in the quasi-particle framework, an excluded volume correction has been included for the nuclear equation of state at suprasaturation density which takes into account the finite size of the nucleons. Results: These novel aspects, excluded volume in the hadronic phase and the higher-order repulsive interactions in the quark phase, lead to a strong first-order phase transition with large latent heat, i.e. the energy-density jump at the phase transition, which fulfils a criterion for a disconnected third-family branch of compact stars in the mass-radius relationship. These twin stars appear at high masses ($\sim$ 2 M$_\odot$) that are relevant for current observations of high-mass pulsars. Conclusions: This analysis offers a unique possibility by radius observations of compact stars to probe the QCD phase diagram at zero temperature and large chemical potential and even to support the existence of a critical point in the QCD phase diagram.Comment: Accepted for publication in Astron. & Astrophy

Appraising Forgeability and Surface Cracking in New Generation Cast and Wrought Superalloys

Surface cracking poses a major problem in industrial forging, but the scientific understanding of the phenomenon is hampered by the difficulty of replicating it in a laboratory setting. In this work, a novel laboratory-scale experimental method is presented to investigate forgeability in new generation cast and wrought superalloys. This new approach makes possible appraising the prevalence and severity of surface cracking by mimicking the die chilling effects characteristic of hot die forging. Two high γ′-reinforced alloys are used to explore this methodology. A Gleeble thermo-mechanical simulator is used to conduct hot compression tests following a non-isothermal cycle, with the aim to simulate the cooling of the near-surface regions during the forging process. FEA simulations, sample geometry design, and heat-treatments are used to ensure the correspondence between laboratory and real-scale forging. A wide range of surface cracking results are obtained for different forging temperatures and cooling rates—proving the soundness of the method. Surprisingly, samples heated up to higher initial temperatures typically show more extensive surface cracking. These findings indicate that—along with the local mechanical conditions of the forging—die-chilling effects and forging temperatures are paramount in controlling surface cracking, as they dictate the key variables governing the distribution and kinetics of γ′ formation

The Lippmann–Schwinger Formula and One Dimensional Models with Dirac Delta Interactions

We show how a proper use of the Lippmann–Schwinger equation simplifies the calculations to obtain scattering states for one dimensional systems perturbed by N Dirac delta equations. Here, we consider two situations. In the former, attractive Dirac deltas perturbed the free one dimensional Schrödinger Hamiltonian. We obtain explicit expressions for scattering and Gamow states. For completeness, we show that the method to obtain bound states use comparable formulas, although not based on the Lippmann–Schwinger equation. Then, the attractive N deltas perturbed the one dimensional Salpeter equation. We also obtain explicit expressions for the scattering wave functions. Here, we need regularisation techniques that we implement via heat kernel regularisation

The societal cost of treatment-seeking patients with borderline personality disorder in Germany

According to previous research, borderline personality disorder (BPD) is associated with high cost-of-illness. However, there is still a shortage of cost-of-illness-studies assessing costs from a broad societal perspective, including direct and indirect costs. Further, there are considerable differences in the results among the existing studies. In the present study, 167 German men and women seeking specialized outpatient treatment for BPD were included. We assessed societal cost-of-illness bottom-up through structured face-to-face interviews and encompassed a wide range of cost components. All costs were calculated for the 2015 price level. Cost-of-illness amounted to € 31,130 per patient and year preceding disorder-specific outpatient treatment. € 17,044 (54.8%) were direct costs that were mostly related to hospital treatment. Indirect costs amounted to € 14,086 (45.2%). Within indirect costs, costs related to work disability were the most crucial cost driver. The present study underlines the tremendous economic burden of BPD. According to the present study, both the direct and indirect costs are of significant importance for the societal costs associated with BPD. Besides the need for more disorder-specific treatment facilities for men and women with BPD, we assume that education and employment are topics that should be specifically targeted and individually supported at an early stage of treatment. Trial Registration: German Clinical Trial Registration, DRKS00011534, Date of Registration: 11/01/2017, retrospectively registered

Aspectos de la fisiología y el cultivo del lulo (Solanum quitoense LAM.) en Colombia: una revisión

Contextualization: lulo is a promising fruit of high demand in the markets due to its excellent organoleptic properties, as well as an important source of vitamins and minerals.  Knowledge gap: in the last ten years, multiple investigations have been carried out about  the ecophysiology of the lulo plant, without  a previous literature review of this.  Purpose: collect general aspects of the lulo crop, including the main agronomic requirements and ecophysiological aspects for sustainable production.  Methodology: the research was based on a methodical and orderly review of the most relevant studies published in different databases.  Results and conclusions: lulo plants grows between 1,900 and 2,200 m. a. s. l. in Colombia with temperatures of 15 to 24 °C. It requires between 1,500 to 2,500 mm of precipitation per year. It appears like a short-day plant, which exhibits its best development in shady places with relative humidity close to 80 %. The most efficient pollination method is carried out by bumblebees (Bombus terrestris and Bombus sp.) through vibrations. The net photosynthesis of the lulo plants varies from 5.52 to 34.03 μmol CO2 m-2 s-1 at 398 and 460 days after transplanting, while the maximum efficiency of photosystem II (FV/Fm) in the lulo crop oscillates between 0.55 and 0.65 for plants without and with foliar nitrogen application. The values ​​of a, b, and total chlorophyll, for lulo plants, are higher in plants in the transplant stage than in production, due to the reduced photosynthetic area. High concentrations of nitrogen (N) (greater than 110 mg L-1) lead to better yield and a larger leaf area. The lulo plant begins its production between eight and 12 months after being transplanted and average yields of 8.5 t ha-1  have been reported. The development and growth of lulo fruits have a simple sigmoid logistic model. The lulo fruits  in harvest time can reach up to 209 g, with firmness of 58 N and values ​​of 13,6 °Brix and 56.2, 10.8 and 46.8 for the luminosity (L*), chroma a* and chorma b* color parameters, respectively.Contextualización: el lulo es un fruto promisorio de alta demanda en los mercados, debido a sus excelentes propiedades organolépticas, además de ser fuente importante de vitaminas y minerales.  Vacío de conocimiento: en los últimos diez años se han desarrollado múltiples investigaciones sobre la ecofisiología de la planta de lulo, sin que exista una  revisión de literatura de este.  Propósito del estudio: recopilar aspectos generales del cultivo, incluyendo los principales requerimientos agronómicos y aspectos ecofisiológicos para una producción sustentable.  Metodología: la investigación se basó en una revisión metódica y ordenada de los estudios más relevantes publicados en diferentes bases de datos.  Resultados y conclusiones: el cultivo de lulo se cultiva entre los 1900 y 2200 msnm en Colombia, con temperaturas de 15 a 24 °C. Requiere entre 1.500 a 2.500 mm de precipitación al año. Se asemeja a una planta de días cortos, que exhibe su mejor desarrollo en sitios sombreados con humedades relativas cercanas al 80 %. El método más eficiente de polinización es el realizado por abejorros (Bombus terrestris y Bombus sp.) por medio de vibraciones. La fotosíntesis neta del cultivo de lulo varia de 5,52 a 34,03 μmol CO2 m-2 s-1 a los 398 y 460 días después de transplante; mientras que la eficiencia máxima del fotosistema II (Fv/Fm) en el cultivo oscila entre 0,55 y 0,65, para plantas sin y con aplicación de nitrógeno foliar.  Los valores de clorofila (a, b y total) para plantas de lulo son mayores en plantas en etapa de trasplante que en producción, debido a la reducida área fotosintética. Las concentraciones de nitrógeno mayores a 110 mg L-1 generan mejor rendimiento y mayor área foliar. La planta de lulo comienza la producción entre los ocho y 12 meses después ser trasplantada y produce rendimientos promedio de 8,5 t ha-1. El desarrollo y crecimiento de los frutos de lulo tiene un comportamiento que se ajusta a un modelo logístico sigmoide simple. Los frutos de lulo en la cosecha pueden llegar a alcanzar hasta 209 g con una firmeza de 58 N y valores de 13.6 °Brix y 56,2, 10,8 y 46,8 para los parámetros de color luminosidad (L*), cromaticidad a* y cromaticidad b*, respectivamente.O Lulo é uma fruta de grande procura nos mercados devido às suas excelentes propriedades organolépticas, para além de ser uma importante fonte de vitaminas e minerais. É cultivada entre 1.900 e 2.200 m a.s.l. na Colômbia, em uma faixa de temperatura entre 15 e 24 ° C, com uma temperatura base de 9,6 ° C para o crescimento do comprimento do caule. Requer entre 1.500 a 2.500 mm de precipitação por ano. Apresenta-se como uma planta de dia curto, que apresenta seu melhor desenvolvimento em locais sombreados com umidade relativa próxima a 80%. O método de polinização mais eficiente é realizado por abelhas (Bombus terrestris) por meio de vibrações. A fotossíntese líquida da cultura do lulo varia de 5,52 a 34,03 mmol CO2 m-2 s-1 aos 398 e 460 dias após o transplante, enquanto a eficiência fotossintética do fotossistema II na cultura do lulo oscila entre 0, 55 e 0,65 para as plantas sem e com aplicação foliar de nitrogênio. Os valores de clorofila a, clorofila be clorofila total para plantas de lulo são maiores nas plantas em fase de transplante do que em produção, o que é atribuído ao fato de as plantas na fase de transplante apresentarem área fotossintética reduzida com altas concentrações de clorofila. Altas concentrações de N (maiores que 110 mg L-1) proporcionam melhor produtividade e maior área foliar. A planta de lulo inicia a produção entre oito e 12 meses após o transplantio e apresenta rendimentos médios de 8,5 t ha-1. O desenvolvimento e crescimento dos frutos de lulo tem um comportamento que obedece a um modelo logístico sigmóide simples. Os frutos lulo na colheita podem atingir até 209 g com firmeza de 58 N e valores de 13,6 ° Brix e 56,2, 10,8 e 46,8 para os parâmetros de cor L *, a * eb *, respectivamente

Performance of the ‘Anna’ apple (Malus domestica Borkh.) in Tropical Highlands: A review

The 'Anna' apple is a variety of low requirements of winter chill (250 to 300 chilling hours ≤7.2°C). This apple has essential health benefits and remarkable adaptive potential in tropical and subtropical areas affected by climate change. Thus, this review presents the significance of the 'Anna' apple cultivation, the phenological and eco-physiological modifications, and the current state of agronomic management when continuous crops are managed in tropical highlands. The production of this apple in tropical highlands has outstanding potential to obtain cyclical or continuous harvests (two harvests per year) in certain areas with specific environmental conditions, implementing a particular management system. In plantations, it is crucial to carry out some agronomic practices during the reproductive phenology so that the apple tree does not enter into an endodormancy. These are water stress - defoliation – tie-down branches, and the application of dormancy-breaking agents (flower-inducing compounds). In Colombia, ‘Anna’ variety was introduced in 1985 and is grown in areas with temperatures between 14 and 20°C, altitudes between 1700 and 2800 meters above sea level (m a.s.l.), with bimodal and monomodal rain regimes, and solar brightness between 800 and 2000 hours a year. The harvest is between 100 to 120 days after anthesis, with firmness values of 38.38N, a soluble solids content of 8.58°Brix, and total titratable acidity of 0.7% of the fruit. This documentation indicates a good production with great potential in terms of growth and development, earliness, and quality of the 'Anna' apple tree in Colombian highlands

Model-independent measurement of the top quark polarisation

We introduce a new asymmetry in the decay t -> W b -> l nu b, which is shown to be directly proportional to the polarisation of the top quark along a chosen axis, times a sum of W helicity fractions. The latter have already been precisely measured at the Tevatron and the Large Hadron Collider. Therefore, this new asymmetry can be used to obtain a model-independent measurement of the polarisation of top quarks produced in any process at hadron or lepton colliders.Comment: LaTeX 12 pages. Discussion expanded with a new plot, references added. Final version to appear in PL