Solid State Analog for He-McKellar-Wilkens Quantum Phase

In this letter we investigate the quantum dynamics of a quasiparticle in the presence of a charged screw dislocation submitted to a uniform magnetic field. Analysing the quantum scattering for this quasiparticle we observed the appearance of a topological quantum phase in the solution and demonstrate that this phenomenon is the solid state analog of the He-McKeller-Wilkens effect.Comment: 7 pages, epl styl

The Time for Parenteral Nutrition is Now: 12 Months Caring for Patients with Severe COVID-19

The coronavirus disease 2019 (COVID-19) pandemic has brought new challenges to adequate nutrition, especially in critically ill patients. Physicians caring for these patients face great difficulties, including a different pathophysiology compared with other diseases, inadequately trained personnel, pressure from the media and family members, logistical and economic obstacles, and lack of robust medical evidence. Although the literature on COVID-19 is still limited, evidence demonstrates the need to reevaluate the use of effective nutritional support in this unprecedented, challenging clinical context. Supplemental parenteral nutrition must be considered due to the energy expenditure from COVID-19, the difficulty in achieving protein and energy goals in patients under enteral nutrition in prone position, and the worsened gastroparesis related to high doses of sedative/neuromuscular blocking agents

Comportamento da conversão de glicose, galactose e lactose em ácido lático por grãos de kefir

Few studies have been reported on lactic acid production by kefir grains. Kefir has been widely associated with probiotic use due to its cell growth in food matrices such as milks, juices and sugary solutions. However, from industrial scale there are no reports of its use in lactic acid production. In this work, we carried out experiments to test and understand how glucose, galactose and lactose, during lactic-acid fermentation, were converted in lactic acid by kefir grains. Given the microbial complexity in coexistence in kefir grains, it is likely that kinetic studies are not the most appropriate for the positive or negative definition of the kefir use as a starter in the lactic acid fermentative production on an industrial scale. It was concluded that, although with a higher Lag phase, lactose was the substrate that best presented a product and cell conversion rate, although glucose and galactose can also be used as a substrate in the production of this carboxylic acid.Poucos estudos foram relatados sobre a produção de ácido lático pelos grãos de kefir. O kefir tem sido amplamente associado ao uso de probióticos devido ao seu crescimento celular em matrizes alimentares como leites, sucos e soluções açucaradas. Entretanto, em escala industrial não há relatos de sua utilização na produção de ácido lático. Neste trabalho, realizamos experimentos para testar e entender como a glicose, galactose e lactose, durante a fermentação láctica, são convertidas em ácido lático pelos grãos de kefir. Dada a complexidade microbiana em coexistência nos grãos de kefir, é provável que os estudos cinéticos não sejam os mais adequados para a definição positiva ou negativa do uso do kefir como starter na produção fermentativa de ácido lático em escala industrial. Concluiu-se que, embora com maior fase Lag, a lactose foi o substrato que melhor apresentou produto e taxa de conversão celular, embora glicose e galactose também possam ser utilizadas como substrato na produção desse ácido carboxílico

Structure-property relationships in high barrier multilayer film/foam systems

Thermoplastic foams nowadays are widely used in a variety of applications, such as packaging, construction, and the automotive industry because of their wide range of properties such as lightweight, excellent strength/weight ratio, insulation properties, energy absorption performance, and material cost. However, there are still issues on the gas barrier and mechanical properties in use because of the cellular structure. This work targeted to unveil the processing-structure-property relationships of three film/foam multilayer polymeric systems with diverse transport properties. The first part of the thesis (Chapter 2) focuses on the understanding of the effect of the number of layers and composition on mechanical properties and barrier properties of multilayer film/foam material with alternating ethylene-vinyl alcohol copolymer (EVOH) film layers and low-density polyethylene (LDPE) foam layers. Tensile properties of the film/foams at elevated temperatures were used to optimize thermoforming conditions. Uniaxial orientation was discovered as an efficient approach to evaluate the potential for thermoforming. Oxygen transmission showed a strong correlation with the thickness reduction which could be used as an indicator for barrier properties of the packaging materials. Film/foam materials with 32 layers demonstrated optimum performance with low oxygen transmission along with high drawing capability. In the third chapter, the previous system (Chapter 2) was innovated with high-density polyethylene (HDPE) skin layer. High oxygen and water vapor barrier film/foam system had been developed using multilayer co-extrusion technology. The film/foams contained alternating low-density polyethylene (LDPE) foam layers and ethylene–vinyl alcohol (EVOH) copolymer film layers with HDPE skin layer. The lightweight film/foams showed oxygen and water vapor transmission rate are correlated with the EVOH film layer and HDPE skin layer composition. The layered film/foam was successfully thermoformed at 80 °C with low oxygen transmission along with high drawing capability. The fourth chapter introduces a novel approach, to produce PLA/PLA multilayer film/foams structures having 16, 32, and 64 alternating layers. The lightweight multilayered PLA/PLA film/foam has a unique solid/porous alternating horizontal architecture, in which the film layers can effectively control the growth of the cells and suppress the premature rupture of cells during coextrusion process. Tensile properties at elevated temperatures of the PLA film were used to optimize thermoforming conditions. The effects of annealing temperature and time on the crystallinity and oxygen permeability of PLA/PLA multilayer film/foams were investigated. Oxygen transmission showed a strong correlation with the crystallinity of PLA/PLA multilayer film/foam. The material demonstrated high performance with low oxygen transmission which could be used as high barrier material

Programming with Quantum Mechanics

Quantum computing is an emerging paradigm that opens a new era for exponential computational speedup. Still, quantum computers have yet to be ready for commercial use. However, it is essential to train and qualify today the workforce that will develop quantum acceleration solutions to get the quantum advantage in the future. This tutorial gives a broad view of quantum computing, abstracting most of the mathematical formalism and proposing a hands-on with the quantum programming language Ket. The target audience is undergraduate and graduate students starting in quantum computing -- no prerequisites for following this tutorial