Solid-state Redox Synthesis of Layered birnessite-type Manganese Dioxide (δ-MnO2) as Aqueous Supercapacitor Electrodes

Nanostructured manganese dioxides are attractive cathode materials in aqueous supercapacitors due to their low cost, environmental benign nature, high theoretical gravimetric capacitance, and power in neutral aqueous electrolytes. In this work, a layered birnessite-type manganese dioxide (δ-MnO2) is synthesized utilizing solid-state redox method with superoxide. The effects of temperature and oxidant amount on the physicochemical properties of δ-MnO2 are characterized using Elemental Dispersion X-ray (EDX) spectroscopy, X-ray diffraction (XRD), N2-sorption, and Scanning Electron Microscope (SEM). The physiochemical properties that are specifically analyzed by varying synthesis conditions pertain to the chemical composition, morphology, and surface area of various δ-MnO2 materials. Through EDX spectroscopy, a link between potassium content and temperature is found with potassium content in the material rising to a maximum of 10.24% with the synthesis temperature at 160°C. The electrochemical performance of δ-MnO2 was evaluated utilizing 3-electrode beaker cells with 1.0 M Na2SO4 as the aqueous electrolyte. The 3-electrode beaker cell consisted of a stainless-steel gauze working electrode, a graphite counter electrode, and an Ag/AgCl reference electrode. Electrochemical tests (cyclic voltammetry) were performed with the synthesized variants of δ-MnO2 and demonstrated high capacitance with values such as 162 F/g at a scan rate of 2mV/s and 106.5 F/g at a scan rate of 20 mV/s

Stakeholder Involvement in Evaluation: Three Decades of the American Journal of Evaluation

Background: Stakeholder involvement in various phases of evaluation has received increasing attention over the past three decades. Indeed, the American Journal of Evaluation (AJE) has reflected this overall philosophy and strategy through a number of publications about several theoretical frameworks and practical applications. Those AJE articles outline the primary assumptions of the stakeholder approaches to evaluation, their practical applications, constraints, and benefits for providing a new direction in evaluation.   Purpose: What lessons are there for our field concerning the way that stakeholder involvement has been conceptualized and applied in AJE? This article focuses on the ways in which AJE authors have approached the notion of stakeholder involvement over the past three decades, drawing on key articles from scholarship on this topic. Setting: Not applicable.   Intervention: Not applicable.   Research Design: Not applicable.   Data Collection and Analysis: Desk review.   Findings: This review shows how AJE has enhanced our understanding of the evolution of these approaches to evaluation, from a global perspective to differentiated approaches with a shared theme.   Keywords: collaborative evaluation; participatory evaluation; empowerment evaluation; stakeholder approaches to evaluation; stakeholder involvemen

Personal Skills, Job Satisfaction, And Productivity In Members Of High Performance Teams

The intention of the study is to identify the development of personal skills, as well as the increase of job satisfaction and productivity of the employee, as a result of their participation in high performance teams. Volunteered in the study 139 members of self-managed teams belonging to the Production Area, 39 of Operational Administrative teams, 19 members of Cross-Functional teams and 6 of 6-Sigma Projects, all of them belonging to a company of the Maquiladora Industry in Tijuana, B.C., Mico. The study indicates that 100% of the members of the Production Area teams and the Operational Administrative teams developed some personal skills or increased their satisfaction or productivity as a result of their participation in some kind of self-managed team. In Cross-Functional teams members, the changes took place in the 94.3% of the cases and in the 97% of the 6-Sigma teams members. There was also a significant difference found between the results of the four types of self-managed teams studied. This paper provides information to CEOs regarding the importance of the design and the implementation of working programs for self-managed teams; these not only will strengthen the employee achievement of a greater satisfaction and productivity, but will also allow them to develop personal skills

Role of serotonergic neurons in the Drosophila larval response to light

<p>Abstract</p> <p>Background</p> <p><it>Drosophila </it>larval locomotion consists of forward peristalsis interrupted by episodes of pausing, turning and exploratory behavior (head swinging). This behavior can be regulated by visual input as seen by light-induced increase in pausing, head swinging and direction change as well as reduction of linear speed that characterizes the larval photophobic response. During 3^rdinstar stage, <it>Drosophila </it>larvae gradually cease to be repelled by light and are photoneutral by the time they wander in search for a place to undergo metamorphosis. Thus, <it>Drosophila </it>larval photobehavior can be used to study control of locomotion.</p> <p>Results</p> <p>We used targeted neuronal silencing to assess the role of candidate neurons in the regulation of larval photobehavior. Inactivation of DOPA decarboxylase (Ddc) neurons increases the response to light throughout larval development, including during the later stages of the 3^rdinstar characterized by photoneutral response. Increased response to light is characterized by increase in light-induced direction change and associated pause, and reduction of linear movement. Amongst Ddc neurons, suppression of the activity of corazonergic and serotonergic but not dopaminergic neurons increases the photophobic response observed during 3^rdinstar stage. Silencing of serotonergic neurons does not disrupt larval locomotion or the response to mechanical stimuli. Reduced serotonin (5-hydroxytryptamine, 5-HT) signaling within serotonergic neurons recapitulates the results obtained with targeted neuronal silencing. Ablation of serotonergic cells in the ventral nerve cord (VNC) does not affect the larval response to light. Similarly, disruption of serotonergic projections that contact the photoreceptor termini in the brain hemispheres does not impact the larval response to light. Finally, pan-neural over-expression of 5-HT1A_Droreceptors, but not of any other 5-HT receptor subtype, causes a significant decrease in the response to light of 3^rdinstar larvae.</p> <p>Conclusion</p> <p>Our data demonstrate that activity of serotonergic and corazonergic neurons contribute to the control of larval locomotion by light. We conclude that this control is carried out by 5-HT neurons located in the brain hemispheres, but does not appear to occur at the photoreceptor level and may be mediated by 5-HT1A_Droreceptors. These findings provide new insights into the function of 5-HT neurons in <it>Drosophila </it>larval behavior as well as into the mechanisms underlying regulation of larval response to light.</p

Older adults and sport and physical activity professionals in Spain

Presence of monitors in physical activities and sports practiced by adults older than 64 years of age in Spain is analyzed in this research. The objective of this study is to determine the existence of monitors in relation to the sociodemographic features of older adults, the size of municipalities, the activities practiced, and the organizations where they are performed. The methodology used included a cross-sectional survey applied to a sample of older adults in Spain. The most relevant conclusions are that the presence of monitors in physical activities and sports practiced by older adults is dominant (63.8%), hence, their importance, and that the presence of monitors is higher for women (81.3%) than for men (37.5%). In addition, it is concluded that the bigger the municipality the higher the tendency to have more instructors. Regarding the type of activity, wide diversification is obtained; finally, there is a larger presence of monitors in sports entities (87.5%) and nursing homes (79.5%)

Modeling and Simulation of Task Allocation with Colored Petri Nets

The task allocation problem is a key element in the solution of several applications from different engineering fields. With the explosion of the amount of information produced by the today Internet-connected solutions, scheduling techniques for the allocation of tasks relying on grids, clusters of computers, or in the cloud computing, is at the core of efficient solutions. The task allocation is an important problem within some branch of the computer sciences and operations research, where it is usually modeled as an optimization of a combinatorial problem with the inconvenience of a state explosion problem. This chapter proposes the modeling of the task allocation problem by the use of Colored Petri nets. The proposed methodology allows the construction of compact models for task scheduling problems. Moreover, a simulation process is possible within the constructed model, which allows the study of some performance aspects of the task allocation problem before any implementation stage

Simulation of Discrete‐Event Systems in MATLAB

The discrete‐event systems (DES) are systems guided by asynchronous events rather than by the passage of the time as in traditional systems. There exists a wide set of systems that could be considered within this class, such as communication protocols, computer and microcontroller operating systems, flexible manufacturing systems, communication drivers for embedded applications and logistic systems, among others. Their proper study is a requirement for a suitable implementation of embedded hardware and software, for example. The aim of this chapter is to approach the simulation of this class of systems within the MATLAB/SIMULINK framework. A suitable simulation process, allowing the injection of input signals to the system and observing its output response, is a first step in the analysis of this class of systems, which may lead to more elaborated analysis such as reachability and deadlock avoidance. The advantage of the approach and techniques proposed in this chapter is the application of the set of tools, algorithms and visualization instruments present in the MATLAB/SIMULINK to the simulation of Discrete‐Event Systems, which allows a simple integration of various DES by utilizing the matrices that define them. The concluding section of the chapter provides a link for downloading all the code for the examples developed here

Alopecia androgenica de inicio precoz como factor asociado a síndrome metabólico

El presente estudio determinó si la alopecia androgénica de inicio precoz es un factor asociado a síndrome metabólico, en los pacientes atendidos en el hospital Victor Lazarte Echegaray en el periodo 2016-2017 MATERIAL Y MÉTODOS: Se realizó un estudio epidemiológico, observacional, analítico, en el hospital Víctor Lazarte Echegaray en pacientes que ha pasado consulta por el servicio de dermatología y que además presentan otras patología. En el estudio los sujetos se seleccionaron en función de que tengan síndrome metabólico(casos=64) o no tengan síndrome metabólico (controles=128), una vez seleccionados los individuos en cada grupo, se buscó identificar y describir la asociación entre el síndrome metabólico y la alopecia androgénica de inicio precoz.Dado que el estudio corresponde a un diseño de casos y controles, se obtuvo el OR para el correspondiente factor de riesgo en cuanto a su asociación entre alopecia androgénica de inicio precoz y síndrome metabólico. Se calculó el intervalo de confianza al 95% del estadígrafo correspondiente. RESULTADOS: Se pudo determinar los resultados del estudio que no existe asociación significativa entre la alopecia androgénica de inicio precoz y el síndrome metabólico, pero si se encontró relación con algunos de los componentes diagnóstico de dicho síndrome; en primer lugar con la hipertensión arterial y en menor proporción con la diabetes y el perímetro abdominal. CONCLUSIONES: Se concluye aunque en el estudio no se demostró asociación entre alopecia androgénica de inicio precoz y síndrome metabólico, se pudo demostrar asociación de alopecia androgénica con algunos de los componentes diagnósticos de síndrome metabólico como los son en primer lugar hipertensión arterial y en la DM II en menor proporción, lo cual nos ayudaría a prevenir futuras complicaciones cardiovasculares, o ligadas a enfermedades coronarias que según los estudios revisados es a lo que se asocia frecuentemente.The present study determined if the alopecia androgenica of precocious start is a factor associated to metabolic syndrome, in the patients attended in the hospital Victor Lazarte Echegaray in the period 2016-2017. MATERIALS AND METHODS: An epidemiological, observational, analytical study was carried out in the Victor Lazarte Echegaray Hospital in patients who have been consulted by the dermatology service and who also have other pathologies. In the study the subjects were selected according to whether they have metabolic syndrome (cases = 64) or do not have metabolic syndrome (controls = 128), once the individuals in each group were selected, we sought to identify and describe the association between the metabolic syndrome And early-onset androgenic alopecia. Because the study corresponds to a case-control design, the OR was obtained for the corresponding risk factor for its association between early-onset androgenic alopecia and metabolic syndrome. The 95% confidence interval of the corresponding statistician was calculated. RESULTS: It was possible to determine the results of the study that there is no significant association between early-onset androgenic alopecia and metabolic syndrome, but if it was found to be related to some of the diagnostic components of this syndrome; In the first place with the arterial hypertension and in smaller proportion with the diabetes and the abdominal perimeter. CONCLUSIONS: Although the association between early-onset androgenic alopecia and metabolic syndrome was not demonstrated in the study, it was possible to demonstrate an association of androgenic alopecia with some of the diagnostic components of metabolic syndrome, such as hypertension and DM II in Lower proportion, which would help us to prevent future cardiovascular complications, or linked to coronary diseases that according to the studies reviewed is what is frequently associated

Influence of Current Pulse Shape on Directly Modulated Systems Performance in Metro Area Optical Networks

Due to the fact that a metro network market is very cost sensitive, direct modulated schemes appear attractive. In this paper a CWDM (Coarse Wavelength Division Multiplexing) system is studied in detail by means of an Optical Communication System Design Software; a detailed study of the modulated current shape (exponential, sine and gaussian) for 2.5 Gb/s CWDM Metropolitan Area Networks is performed to evaluate its tolerance to linear impairments such as signal-to-noise-ratio degradation and dispersion. Point-to-point links are investigated and optimum design parameters are obtained. Through extensive sets of simulation results, it is shown that some of these shape pulses are more tolerant to dispersion when compared with conventional gaussian shape pulses. In order to achieve a low Bit Error Rate (BER), different types of optical transmitters are considered including strongly adiabatic and transient chirp dominated Directly Modulated Lasers (DMLs). We have used fibers with different dispersion characteristics, showing that the system performance depends, strongly, on the chosen DML?fiber couple