Abstract

Abstract
The polyester for bone tissue engineering is produced using different concentrations of hydroxyapatite. Poly(butylene adipate-co-terephthalate) (PBAT) solutions containing different concentrations of nano-hydroxyapatite (nHAp) (1, 2, 3, 4, 5 and 6% wt) were evaluated to assess their potential to produce scaffolds via electrospinning. The characteristics of these solutions were evaluated using surface tension analysis. Different solutions were electrospun and characterized using scanning electron microscopy, X-ray diffractometry (XRD), infrared spectroscopy (FTIR), and differential scanning calorimetry analysis. In vitro and in vivo experiments were performed using MG-63 osteoblast cells and male Wistar rats. The MTT assay was used to evaluate the cytotoxicity of scaffolds. Microtomography and a three-point bend test were used to analyze parameters of bone neoformation 4 weeks after implantation. We observed a requirement for solutions containing nHAp to reach chemical stability to produce ultrathin fibers. FTIR and XRD data demonstrated the presence of carbonate and phosphate groups, and thermal analysis showed a reduction in crystallinity of the nanocomposites when the concentration of nHAp was increased. None of the scaffolds analyzed demonstrated cytotoxicity when compared to controls. All of the PBAT/nHAp scaffolds analyzed promoted bone repair; however, a solution of PBAT with 3% nHAp improved bone volume, force, and stiffness when compared to controls.

Abstract
Light interaction with biological materials depends on the material’s optical properties. From those properties, the absorption and scattering coefficients are the most important, since they quantify how much of a light beam is attenuated when traveling inside a tissue. The scattering coefficient is known to be significantly higher than the absorption coefficient in biological materials, meaning that most of the light is scattered, turning optical methods in clinical practice limited. Such difference between the scattering and absorption coefficients is mainly due to a refractive index mismatch between tissue components and fluids. We explain this concept in the present chapter before introducing the technique that efficiently minimizes this effect in the following chapters. © 2019, The Author(s), under exclusive license to Springer Nature Switzerland AG.

Abstract
The current energy scenario requires actions towards the reduction of energy consumption and the use of renewable resources. In this context, a microgrid is a self-sustained network that can operate connected to the smart grid or in isolation. The long-term scheduling of on/off cycles of devices is a critical problem that has been commonly addressed by centralized approaches. In this work, we propose a novel agent-based method to solve the long-term scheduling problem as a distributed constraint optimization problem (DCOP) by modelling future system configurations rather than reacting to changes. Moreover, with respect to approaches based on decentralised reinforcement learning, we can directly encode system-wide hard constraints (such as for example the Kirchhoff law) which are not easy to represent in a factored representation of the problem. We compare different multi-agent DCOP algorithms showing that the proposed method can find optimal/near-optimal solutions for a specific case study.

Abstract
We report on the direct intensity modulation characteristics of a high-speed resonant tunneling diode-photodetector (RTD-PD) with an oscillation frequency of 79 GHz. This work demonstrates both electrical and optical modulation and shows that RTD-PD oscillators can be utilized as versatile optoelectronic/radio interfaces. This is the first demonstration of optical modulation of an RF carrier using integrated RTD-PD oscillators at microwave frequencies. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement.

Abstract
Students born in a digital era require adjusted teaching and learning methodologies incorporating new technologies. A common difficulty found by students is how to test their controller designs in a real system. Thus, the development of affordable, portable and easy to use feedback control kits is highly desirable. The idea is that both lecturers and students can perform simple practical experiments anytime and anywhere. The APMonitor temperature control lab is an Arduino based control kit which fulfils these requirements. Proportional, integrative and derivative control is in operation in the vast majority of industrial process control loops. Thus, it is a mandatory topic in most undergraduate introductory feedback control courses. A teaching/learning PID control experiment for undergraduate Biomedical Engineering student's based on the temperature control lab is reported here. Results received from students are presented.