Fast model predictive control for hydrogen outflow regulation in ethanol steam reformers

© 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.In the recent years, the presence of alternative power sources, such as solar panels, wind farms, hydropumps and hydrogen-based devices, has significantly increased. The reasons of this trend are clear: contributing to a reduction of gas emissions and dependency on fossil fuels. Hydrogen-based devices are of particular interest due to their significant efficiency and reliability. Reforming technologies are among the most economic and efficient ways of producing hydrogen. In this paper we consider the regulation of hydrogen outflow in an ethanol steam reformer (ESR). In particular, a fast model predictive control approach based on a finite step response model of the process is proposed. Simulations performed using a more realistic non-linear model show the effectiveness of the proposed approach in driving the ESR to different operating conditions while fulfilling input and output constraints.Peer ReviewedPostprint (author's final draft

Probability-guaranteed set-membership state estimation for polynomially uncertain linear time-invariant systems

2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksConventional deterministic set-membership (SM) estimation is limited to unknown-but-bounded uncertainties. In order to exploit distributional information of probabilistic uncertainties, a probability-guaranteed SM state estimation approach is proposed for uncertain linear time-invariant systems. This approach takes into account polynomial dependence on probabilistic uncertain parameters as well as additive stochastic noises. The purpose is to compute, at each time instant, a bounded set that contains the actual state with a guaranteed probability. The proposed approach relies on the extended form of an observer representation over a sliding window. For the offline observer synthesis, a polynomial-chaos-based method is proposed to minimize the averaged H2 estimation performance with respect to probabilistic uncertain parameters. It explicitly accounts for the polynomial uncertainty structure, whilst most literature relies on conservative affine or polytopic overbounding. Online state estimation restructures the extended observer form, and constructs a Gaussian mixture model to approximate the state distribution. This enables computationally efficient ellipsoidal calculus to derive SM estimates with a predefined confidence level. The proposed approach preserves time invariance of the uncertain parameters and fully exploits the polynomial uncertainty structure, to achieve tighter SM bounds. This improvement is illustrated by a numerical example with a comparison to a deterministic zonotopic method.Peer ReviewedPostprint (author's final draft

Cladistic analysis of the pennatulacean genus \u3ci\u3eRenilla\u3c/i\u3e Lamarck, 1816 (Coelenterata, Octocorallia)

The genus Renilla is an interesting taxon for phylogenetic studies, which includes six species endemic to America with an anphiamerican distribution (Pacific–Atlantic Ocean). A cladistic analysis of Renilla Lamarck, 1816 using eight characters from external morphology produced one cladogram (length 14, CI = 0.92, RI = 0.87), and the characters were polarized using Echinoptilum macintoshii Hubrecht, 1885 as an outgroup. In the cladogram the following phylogenetic sequence results: ((R. koellikeri (R. muelleri, R. musaica)) (R. octodentata (R. reniformis, R. tentaculata)))

Alterations in prefrontal-limbic functional activation and connectivity in chronic stress-induced visceral hyperalgesia.

Repeated water avoidance stress (WAS) induces sustained visceral hyperalgesia (VH) in rats measured as enhanced visceromotor response to colorectal distension (CRD). This model incorporates two characteristic features of human irritable bowel syndrome (IBS), VH and a prominent role of stress in the onset and exacerbation of IBS symptoms. Little is known regarding central mechanisms underlying the stress-induced VH. Here, we applied an autoradiographic perfusion method to map regional and network-level neural correlates of VH. Adult male rats were exposed to WAS or sham treatment for 1 hour/day for 10 days. The visceromotor response was measured before and after the treatment. Cerebral blood flow (CBF) mapping was performed by intravenous injection of radiotracer ([(14)C]-iodoantipyrine) while the rat was receiving a 60-mmHg CRD or no distension. Regional CBF-related tissue radioactivity was quantified in autoradiographic images of brain slices and analyzed in 3-dimensionally reconstructed brains with statistical parametric mapping. Compared to sham rats, stressed rats showed VH in association with greater CRD-evoked activation in the insular cortex, amygdala, and hypothalamus, but reduced activation in the prelimbic area (PrL) of prefrontal cortex. We constrained results of seed correlation analysis by known structural connectivity of the PrL to generate structurally linked functional connectivity (SLFC) of the PrL. Dramatic differences in the SLFC of PrL were noted between stressed and sham rats under distension. In particular, sham rats showed negative correlation between the PrL and amygdala, which was absent in stressed rats. The altered pattern of functional brain activation is in general agreement with that observed in IBS patients in human brain imaging studies, providing further support for the face and construct validity of the WAS model for IBS. The absence of prefrontal cortex-amygdala anticorrelation in stressed rats is consistent with the notion that impaired corticolimbic modulation acts as a central mechanism underlying stress-induced VH

COVID-19 Pandemic’s Effect on Occupational Therapy Students’ Time-Use and Occupational Engagement On Returning to In-Person Learning

The COVID-19 pandemic emotionally and physically impacted students in occupational therapy and occupational therapy assistant programs. College students lost autonomy and access to meaningful occupations and environments. As students returned to campus, they struggled to navigate and adapt to in-person occupations and how they use their time. This study uses a mixed method descriptive research design to understand how the pandemic affected occupational therapy students\u27 time-use and occupational engagement during the transition to in-person learning. Seventy-three students completed an online survey, while 12 of those students additionally participated in a follow-up time-use diary and interview. Eighty-three percent of the participants agreed or strongly agreed they learned more effectively in-person compared to online, while 65% agreed or strongly agreed to make time to participate in satisfying occupations. Three themes emerged after the thematic analysis of the qualitative data: time compression, lessons from adapting, and autonomy and choice. The findings provide perspectives on occupational therapy students\u27 ability to adapt and manage their time during this transition and offer insight into other transitions in their programs

Control-oriented thermal modeling methodology for water-cooled PEM fuel-cell-based systems

In this paper, a new control-oriented modeling methodology for the thermal dynamics of water-cooled Proton Exchange Membrane Fuel Cells (PEMFCs) is presented and validated. This methodology is not only useful for control applications, but also can be used for predicting the temperature variation across the stack, allowing to monitor its operation. The methodology has been validated in a real 600-W, 20-cells, water cooled PEMFC, with encouraging results for both the stationary and the transient states. Results show that the proposed methodology is accurate and suitable for control purposes.Peer Reviewe

Control-oriented thermal modeling methodology for water-cooled PEM fuel-cell-based systems

In this paper, a new control-oriented modeling methodology for the thermal dynamics of water-cooled Proton Exchange Membrane Fuel Cells (PEMFCs) is presented and validated. This methodology is not only useful for control applications, but also can be used for predicting the temperature variation across the stack, allowing to monitor its operation. The methodology has been validated in a real 600-W, 20-cells, water cooled PEMFC, with encouraging results for both the stationary and the transient states. Results show that the proposed methodology is accurate and suitable for control purposes.Peer Reviewe

El diagnóstico por imagen de las hernias de la pared abdominal

Abdominal wall hernias in their different modalities form a group of commonly encountered surgical conditions. They vary in their presentation from asymptomatic to life threatening emergencies. Clinical history and physical examination are the primary methods for diagnosis, however in a significant percentage of patients, a normal physical examination can be found. Due to this, diagnostic imaging has been gaining attention in recent years, which in addition to identifying the cases of abdominal hernias with normal physical examination, provide additional relevant data. In this article we review available literature regarding the usefulness of diagnostic imaging such as herniography, ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) for the diagnosis of abdominal wall hernias. CT and ultrasound are the main modalities used for the diagnosis and characterization of the hernia defect. CT is recommended when there is uncertainty in the diagnosis after the physical examination or initial ultrasound, or as a first option if complications are suspected. Evaluation using imaging is important both as a diagnostic tool and for an adequate anatomical characterization in patients with suspected abdominal wall hernias. © 2019 Sociedad Hispanoamericana de Hernia. Publicado por Arán Ediciones, S.L. Todos los derechos reservados

Interface layer to improve polystyrene attachment on a quartz crystal resonator

Se describe el empleo de técnicas de formación de películas tendientes a mejorar el funcionamiento de un resonador de cristal de cuarzo (QCR); dichas tecnologías fueron, por ejemplo, preparaciones de recubrimiento mediante los métodos de spin y Langmuir-Blodgett (LB). La uniformidad y homogeneidad de la película sobre el cristal de cuarzo es fundamental para las aplicaciones que tiene un resonador como sensor químico y biológico. Se formaron películas de poliestireno (PS) y de cloruro de polivinilo (PVC) en solventes como ciclohexanona, tetrahidrofurano (THF), dimetilformamida y cloroformo a diferentes concentraciones, usando el procedimiento de cubrimiento por spin en soportes corrugados tipo wafer. La calidad de las películas fue determinada usando microscopía óptica, elipsometría y perfilometría. Además, se prepararon películas en soportes corrugados y en QRC con superficie de oro por irrigación de la mencionada sustancia en una subfase acuosa y transfiriéndola por impregnación de la superficie de subfase en el soporte. Para la preparación de la película LB se empleó ácido araquídico y partículas de PS. Las preparaciones de películas de monocapa y multicapa de estas sustancias en soportes corrugados o en superficies de cuarzo doradas se controlaron adicionalmente por espectrometría IR. El comportamiento resonante del QCR antes y después del recubrimiento de su superficie se midió con un analizador de red. En combinación con una interfaz gráfica los datos se pudieron fácilmente grabar y observar.Technologies for thin film deposition have been used to improve the functionalization of quartz crystal resonators (QCR); such technologies, for example, are spin coating and Langmuir-Blodgett (LB) film preparation. These experiments are required because the film uniformity and homogeneity over the quartz crystal resonator are fundamental for its applications as chemical and biological sensors. Film deposition of polystyrene (PS) particles, as well as polyvinyl chloride (PVC), was performed in solvents such as cyclohexanone, tetrahydrofuran (THF), dimethylformamide and chloroform at different concentrations using the spin coating procedure on wafer targets. The film quality was determined by optical microscopy, ellipsometry, and profilometry. Additionally, films on wafers or QCR with gold surface have been prepared by spreading the mentioned substances on an aqueous subphase and transferring it by dipping from the subphase surface onto the target. For LB film preparation arachidic acid and PS particles have been used. Prepared mono- or multilayered films of these substances on wafer or gold quartzes have been controlled additionally by IR-spectrometry. The resonant behavior of QCR before and after surface coating has been measured with a network analyzer. In combination with a graphical user interface the data could be easily recorded and visualized

Vector boson fusion topology and simplified models for dark matter searches at colliders

In this paper we study the possible searches at colliders using Vector Boson Fusion topology in the context of Simplified Models signatures. We examine the possible physics reach of these searches with regard to monojet-type searches, and determine how these two signatures are complementary