Solar Power Generation Profile Estimation for Lunar Surface Solar PV Systems

As NASA prepares to carry out its Artemis lunar missions, the design and planning of robust power systems tailored to the lunar environment become necessary and urgent. Solar photovoltaic (PV) systems are among the most suitable power generators for lunar applications given the abundant solar irradiance the lunar surface receives as a result of the lack of an atmosphere. However, the vastly different environmental conditions of the moon compared to those on Earth call for special reconsiderations to the traditional PV power output models used for terrestrial applications. The substantially wider range of temperatures on the moon combined with the absence of atmosphere implies the PV will operate at very different thermal conditions. Therefore, this paper proposes a PV power output model that determines PV cell temperature on the lunar surface based on lunar ambient temperature as well as solar irradiance, while also capturing these special lunar conditions. The model is based on thermal exchange via the three main heat transfer paths: heat radiation, absorption, and convection. Moreover, four different array configurations are presented and compared to determine the most suitable choice based on energy generation and complexity for different locations around the moon

Resilient Operational Planning for Microgrids Against Extreme Events

This paper proposes a novel resilience index, a microgrid survivability rate (SR) under extreme events, and then proposes a novel Resilient Operational Planning (ROP) algorithm to maximize the proposed resilience index SR. The proposed ROP algorithm can incorporate predetermined inverter failure probabilities and generate multiple scenarios accordingly to optimize resilient operations during an extreme event. The implemented ROP algorithm consists of two main steps: (i) optimization of resilient operational planning, and (ii) preventive resilience enhancement if minimum SR is not met per the analysis in step 1. A typical microgrid (MG) is studied to compare the proposed ROP algorithm against a traditional microgrid energy management (MEM) model. Results indicate that an enhanced resilience operation is achieved by the ROP algorithm, which is demonstrated by the quantification of resilience via the SR. Moreover, the proposed ROP algorithm is able to obtain a greater SR overall compared to that achieved by the traditional MEM, and this benefit of using the proposed ROP increases as the inverter failure probabilities increase

Greenhouse gases emissions and electric power generation in Latin American countries in the period 2006–2013

The objective of this study is to classify the group of countries that contributes to the emissions of GHG gases in relation to their electric power generation. The data used for this classification are those reported by OLADE during the period from 2006 to 2013. The results show that they were organized in four (4) clusters, dividing them into efficient and inefficient levels. In the highest efficient level is Brazil, while in the lowest efficient level are Colombia, Costa Rica, El Salvador, Panama, Paraguay, Peru, Uruguay, and Venezuela. Argentina and Mexico are in the highest inefficient level, while the rest of the Latin American countries are in the lowest inefficient level. The countries located at the efficient and inefficient levels were labeled as most emitting countries and least emitting countries

Customer relationship management CRM y gestión de clientes en una entidad financiera, Carabayllo, 2022

El presente trabajo de investigación plantea su objetivo general determinar el nivel de relación entre el CRM y la gestión de clientes en una entidad financiera, Carabayllo, 2022. La investigación es de tipo aplicada, descriptiva correlacional, con un diseño no experimental de corte transversal. En lo relacionado a la población y muestra estuvo caracterizada por un total de Ochenta (80) colaboradores, a los cuales se les aplicó una encuesta con escala de Likert, el instrumento que se utilizó fue un cuestionario con veinte (20) ítems, el cual constituye un conjunto de interrogantes relacionadas con las variables. De igual manera, se utilizó el aplicativo estadístico SPSS Versión 26, para procesar la información y comprender las variables y establecer su correlación e implicancia. La investigación permite llegar a la siguiente conclusión: se determinó que existe una relación correlación positiva baja entre las variables CRM y gestión de clientes en la entidad financiera, Carabayllo, el cual quedó demostrada por el coeficiente Rho de Spearman, R=0,342 teniendo un Sig. Bilateral (0,002<0.05

Competencias digitales y su influencia en el desempeño docente del colegio José Carlos Mariategui, Jayanca 2021

El presente trabajo titulado Competencias Digitales y su influencia en el Desempeño Docente del colegio José Carlos Mariátegui, Jayanca 2021, tuvo como objetivo Determinar la influencia de las competencias digitales en el desempeño docente del colegio José Carlos Mariátegui, Jayanca 2021. Esta investigación es de tipo descriptiva, cuantitativa, correlacional y diseño no experimental, utilizandose una población – muestra de 18 docentes de la institución educativa Carlos Mariátegui, tanto de nivel primario como secundario. Para la obtención de datos, se utilizó como técnica la encuesta, y como instrumento un cuestionario, basado en la escala de Likert, que contuvo 10 ítems que corresponden a la variable Competencias Digitales y 10 ítems que corresponden a la variable Desempeño. Se obtuvo como resultados que los docentes están en un nivel regular con un 44% en competencias digitales, y además están en un nivel regular en cuanto a su desempeño en la institución con un 50%. Se concluyó que las dimensiones que más influyen en el desempeño docente, es la comunicación y colaboración, creación de contenidos y resolución de problemas, y al obtener p=0,00, se demostró y se verificó que las competencias digitales influyen en el desempeño docente del colegio José Carlos Mariátegui, Jayanca 2021.TesisGestión empresarial y emprendimient

Differential effects of tau stage, Lewy body pathology, and substantia nigra degeneration on FDG-PET patterns in clinical AD

PURPOSE: Comorbid Lewy body (LB) pathology is common in AD. The effect of LB co-pathology on FDG-PET patterns in AD is yet to be studied. We analysed associations of neuropathologically-assessed tau pathology, LB pathology, and substantia nigra neuron loss (SNnl) with ante-mortem FDG-PET hypometabolism in patients with a clinical AD presentation. METHODS: Twenty-one patients with autopsy-confirmed AD (‘pure-AD’), 24 with AD and LB co-pathology (‘AD-LB’), and 7 with LB but no or low evidence of AD pathology (‘pure-LB’) were studied. Pathologic groups were compared on regional and voxel-wise FDG-PET patterns, the cingulate island sign ratio (CISr), and neuropathological ratings of SNnl. Additional analyses assessed continuous associations of Braak tangle stage and SNnl with FDG-PET patterns. RESULTS: Pure-AD and AD-LB showed highly similar patterns of AD-typical temporo-parietal hypometabolism and did not differ in CISr, regional FDG SUVR, or SNnl. By contrast, pure-LB showed the expected DLB-like pattern, accompanied by pronounced occipital hypometabolism and elevated CISr and SNnl compared to the AD groups. In continuous analyses, Braak tangle stage was significantly correlated with more AD-like, and SNnl with more DLB-like, FDG-PET patterns. CONCLUSIONS: In autopsy-confirmed AD dementia patients, comorbid LB pathology did not have a notable effect on the regional FDG-PET pattern. A more DLB-like FDG-PET pattern was observed in relation to SNnl, but advanced SNnl was mostly limited to relatively pure LB cases. AD pathology may have a dominant effect over LB pathology in determining the regional neurodegeneration phenotype

PLANEACIÓN DIDÁCTICA GENERAL DE LA ASIGNATURA: FILOSOFÍA

GUÍA DIDÁCTICA / PLANEACIÓN DIDÁCTICA (NMS

PLANEACIÓN DIDÁCTICA GENERAL DE LA ASIGNATURA: LÓGICA

GUÍA DIDÁCTICA / PLANEACIÓN DIDÁCTICA (NMS

Effect of Boriding on the Mechanical Properties of AISI 1045 Steel

Efecto en las propiedades mecánicas de un acero borurado 1045.Some mechanical properties of AISI 1045 borided steels were estimated in the present work. The boriding process was carried out by the powder pack method at 950°C with 8 h of treatment. The fatigue strength on borided notched specimens was evaluated with rotating bending tests (R=1) considering a stress concentration factor (Kt) of 2.53. Likewise, the presence of residual stresses in boride layers was established by the XRD technique. The Daimler-Benz Rockwell C test was used, also, to estimate the strength adhesion of the coated system. The results show a decrease in the fatigue strength of AISI borided steels due to the presence of high porosity in the layers. Finally, the Rockwell-C adhesion test showed no coating failure for the boride layer

Measures of concentration and stability: two pedagogical tools for industrial organization courses

This document describes two pedagogical tools developed for teaching applied microeconomics, specifically the issues related to concentration, dominance, stability and asymmetry of firms. The tools make a compilation of several concentration and stability indexes used in the literature since 1945. Among the benefits of the applications are the ease and agility to perform comparative analyzes of intersectorial and/or intertemporal type in a simple and agile way; and the use of unconventional concentration and stability measures