Three-Body Dynamics and Self-Powering of an Electrodynamic Tether in a Plasmasphere

The dynamics of an electrodynamic tether in a three-body gravitational environment are investigated. In the classical two-body scenario the extraction of power is at the expense of orbital kinetic energy. As a result of power extraction, an electrodynamic tether satellite system loses altitude and deorbits. This concept has been proposed and well investigated in the past, for example for orbital debris mitigation and spent stages reentry. On the other hand, in the three-body scenario an electrodynamic tether can be placed in an equilibrium position fixed with respect to the two primary bodies without deorbiting, and at the same time generate power for onboard use. The appearance of new equilibrium positions in the perturbed three-body problem allow this to happen as the electrical power is extracted at the expenses of the plasma corotating with the primary body. Fundamental differences between the classical twobody dynamics and the new phenomena appearing in the circular restricted three-body problem perturbed by the electrodynamic force of the electrodynamic tether are shown in the paper. An interesting application of an electrodynamic tether placed in the Jupiter plasma torus is then considered, in which the electrodynamic tether generates useful electrical power of about 1 kW with a 20-km-long electrodynamic tether from the environmental plasma without losing orbital energy

The Effect of Store Brand Image and Service Quality Towards Customer Loyalty at Freshmart Superstore Manado

Customer loyalty has been recognized as the dominant factor in a superstores success. The customer loyalty subject has become of increased interest to most superstore in the competitive situation over the last few years. Store brand image and service quality describes what customers are looking for that is likely to be advantageous to the Superstore. The objectives of this research are to analyze the effect of store brand image, and service quality towards consumer loyalty, simultaneously and partially. Data was analyzed quantitatively and through use of statistical package for social scientists (SPSS). The research method that used in this research is multiple linear regression analysis with the sample of the respondents is 100 samples that were obtained from all the customers who shopping in Freshmart Superstore Manado. The result from this research shown that the store brand image and service quality have a significant effects simultaneously on customer loyalty. Whereas store brand image does have positive effect but not significant partially to customer loyalty. This study reveals that store brand image and service quality in a superstore has a strong effect to bring customer satisfaction, trust, and commitment to being loyal customer. It can improve more by should keep and maintain the worker inside the store, especially in terms make an interesting services at Freshmart Superstore. Keywords: store brand image, service quality, customer loyalt

Energy Analysis of Bare Electrodynamic Tethers

The design of an electrodynamic tether is a complex task that involves the control of dynamic instabilities, optimization of the generated power (or the descent time in deorbiting missions), and minimization of the tether mass. The electrodynamic forces on an electrodynamic tether are responsible for variations in the mechanical energy of the tethered system and can also drive the system to dynamic instability. Energy sources and sinks in this system include the following: 1) ionospheric impedance, 2) the potential drop at the cathodic contactor, 3) ohmic losses in the tether, 4) the corotational plasma electric field, and 5) generated power and/or 6) input power. The analysis of each of these energy components, or bricks, establishes parameters that are useful tools for tether design. In this study, the nondimensional parameters that govern the orbital energy variation, dynamic instability, and power generation were characterized, and their mutual interdependence was established. A space-debris mitigation mission was taken as an example of this approach for the assessment of tether performance. Numerical simulations using a dumbbell model for tether dynamics, the International Geomagnetic Reference Field for the geomagnetic field, and the International Reference Ionosphere for the ionosphere were performed to test the analytical approach. The results obtained herein stress the close relationships that exist among the velocity of descent, dynamic stability, and generated power. An optimal tether design requires a detailed tradeoff among these performances in a real-world scenario

Early cataloguing of fragments from break-up events

Break-up events represent the dominant source of objects in space catalogues, surpassing half of the overall population. These not so uncommon events include explosions, collisions or anomalous events resulting in fragmentations and their number is estimated to be higher than 630. The early cataloguing of the fragments generated during these events poses a complex challenge for space objects catalogue build-up and maintenance processes. The provision of Space Surveillance and Tracking products and services during the few first days after a break-up event can be crucial to avoid collisions between the fragments and other space objects, particularly in highly congested regimes, such as Low Earth Orbit. In this regard, reducing the time required to accurately estimate the trajectories of the fragments may enable the execution of collision avoidance manoeuvres, in the case of operational space objects with manoeuvre capabilities, and analyse potential collision cascade events, which may endanger the space environment. This paper studies the whole cataloguing process after a break-up event, starting from a catalogue with no fragments from the fragmentation under-analysis, and until a well-established orbit is obtained for all fragments, using a ground-based sensor network. First, the observations enter a multi-sensor multi-target track-to-track association algorithm in charge of grouping observations belonging to the same objects. To resolve the ambiguity, particularly shortly after the event, hypotheses about tracks belonging to the same fragment are generated, scored, pruned, and promoted, only when there is enough confidence, leading to the initialisation of new objects in the catalogue. As soon as the catalogue is populated, a track-to-orbit correlation algorithm is responsible for the correlation of observations and already catalogued orbits. This alleviates the track-to-track association and enables the update of the orbital estimates, required for maintaining the catalogue.This work was conducted during the research stay of A. Pastor in the ESA Space Debris Office at ESOC in Darmstadt. The corresponding author greatly appreciates the warm welcome, interest and support of the whole team. This project has received funding from the ”Comunidad de Madrid” under ”Ayudas destinadas a la realización de doctorados industriales” program (project IND2017/TIC7700).Publicad

Students Perceptions About Online Learning During the Covid 19 Padem at the Faculty of Social and Political Sciences Sam Ratulangi University

Through the process of sensing, organizing, and interpreting the learning process itself, the application of online learning creates perceptions in students in viewing, interpreting, interpreting, concluding, and reacting to the learning process and results received. Online learning creates these perceptions in students through the process of sensing, organizing, and interpreting the learning process itself. There are three components that contribute to one's perception. Among them are: Perceiver; the individual who delivers the perception. The thing or person that is the focus of attention; the person or thing that is the object of perception. The circumstance; the condition at which the perception is carried out. It is intended that the Faculty of Social and Political Sciences at Sam Ratulang University would be able to assist government initiatives for the Implementation of the SPADA Program and remain at home, study from home, and work from home programs via the use of online learning. Students are also expected to develop into Human Resources that are prepared to participate in the workforce since they are able to grasp not just science but also technology and are ready to join the 4.0 age. This is part of the expectation that they will be ready to compete in the workforce

Comparison of the efficiency of the nebulization of salbutamol, epinephrine and normal saline on treatment of bronchiolitis

Background: Bronchiolitis is a frequent cause of hospitalization. Despite the frequency of this pathology, there is not a single, widely practiced evidence-driven treatment especially using of nebulization. Present purpose was to compare which is efficient: nebulized salbutamol, epinephrine or normal saline.Methods: We have preceded to a prospective study from January 1st 2011 to March 31st 2012 including children between 29 days old and 2 years old.Results: We have included 90 patients divided in three groups and received nebulized salbutamol, epinephrine or normal saline. There was no real difference in the variables of the groups: clinical score, oxygen saturation, heart rate, temperature and weight but the hospitalization duration was shorter in the group who have been cured by normal salineConclusions: This study shows that salbutamol, epinephrine and normal saline can be used in the same situation but the normal saline has more advantages because of his low coast and the absence of risk of side effects

Valorization of kiwi agricultural waste and industry by-products by recovering bioactive compounds and applications as food additives: a circular economy model

Currently, agricultural production generates large amounts of organic waste, both from the maintenance of farms and crops (agricultural wastes) and from the industrialization of the product (food industry waste). In the case of Actinidia cultivation, agricultural waste groups together leaves, flowers, stems and roots while food industry by-products are represented by discarded fruits, skin and seeds. All these matrices are now underexploited and so, they can be revalued as a natural source of ingredients to be applied in food, cosmetic or pharmaceutical industries. Kiwifruit composition (phenolic compounds, volatile compounds, vitamins, minerals, dietary fiber, etc.) is an outstanding basis, especially for its high content in vitamin C and phenolic compounds. These compounds possess antioxidant, anti-inflammatory or antimicrobial activities, among other beneficial properties for health, but stand out for their digestive enhancement and prebiotic role. Although the biological properties of kiwi fruit have been analyzed, few studies show the high content of compounds with biological functions present in these by-products. Therefore, agricultural and food industry wastes derived from processing kiwi are regarded as useful matrices for the development of innovative applications in the food (pectins, softeners, milk coagulants, and colorants), cosmetic (ecological pigments) and pharmaceutical industry (fortified, functional, nutraceutical, or prebiotic foods). This strategy will provide economic and environmental benefits, turning this industry into a sustainable and environmentally friendly production system, promoting a circular and sustainable economy.The research leading to these results was supported by MICINN supporting the Ramón y Cajal grant for M.A. Prieto (RYC-2017-22891); by Xunta de Galicia for supporting the program EXCELENCIA-ED431F 2020/12, the post-doctoral grant of M. Fraga-Corral (ED481B-2019/096), the pre-doctoral grant of M. Carpena (ED481A 2021/313), the program BENEFICIOS DO CONSUMO DAS ESPECIES TINTORERA-(CO-0019-2021) that supports the work of F. Chamorro and by the program Grupos de Referencia Competitiva (GRUPO AA1-GRC 2018) that supports the work of J. Echave. Authors are grateful to Ibero-American Program on Science and Technology (CYTED—AQUA-CIBUS, P317RT0003), to the Bio Based Industries Joint Undertaking (JU) under grant agreement No 888003 UP4HEALTH Project (H2020-BBI-JTI-2019). The JU receives support from the European Union’s Horizon 2020 research and innovation program and the Bio Based Industries Consortium. The project SYSTEMIC Knowledge hub on Nutrition and Food Security, has received funding from national research funding parties in Belgium (FWO), France (INRA), Germany (BLE), Italy (MIPAAF), Latvia (IZM), Norway (RCN), Portugal (FCT), and Spain (AEI) in a joint action of JPI HDHL, JPI-OCEANS and FACCE-JPI launched in 2019 under the ERA-NET ERA-HDHL (n° 696295). Funding for open access charge: Universidade de Vigo/CISUG.info:eu-repo/semantics/publishedVersio

Protection from pulmonary ischemia-reperfusion injury by adenosine A2A receptor activation

<p>Abstract</p> <p>Background</p> <p>Lung ischemia-reperfusion (IR) injury leads to significant morbidity and mortality which remains a major obstacle after lung transplantation. However, the role of various subset(s) of lung cell populations in the pathogenesis of lung IR injury and the mechanisms of cellular protection remain to be elucidated. In the present study, we investigated the effects of adenosine A_2Areceptor (A_2AAR) activation on resident lung cells after IR injury using an isolated, buffer-perfused murine lung model.</p> <p>Methods</p> <p>To assess the protective effects of A_2AAR activation, three groups of C57BL/6J mice were studied: a sham group (perfused for 2 hr with no ischemia), an IR group (1 hr ischemia + 1 hr reperfusion) and an IR+ATL313 group where ATL313, a specific A_2AAR agonist, was included in the reperfusion buffer after ischemia. Lung injury parameters and pulmonary function studies were also performed after IR injury in A_2AAR knockout mice, with or without ATL313 pretreatment. Lung function was assessed using a buffer-perfused isolated lung system. Lung injury was measured by assessing lung edema, vascular permeability, cytokine/chemokine activation and myeloperoxidase levels in the bronchoalveolar fluid.</p> <p>Results</p> <p>After IR, lungs from C57BL/6J wild-type mice displayed significant dysfunction (increased airway resistance, pulmonary artery pressure and decreased pulmonary compliance) and significant injury (increased vascular permeability and edema). Lung injury and dysfunction after IR were significantly attenuated by ATL313 treatment. Significant induction of TNF-α, KC (CXCL1), MIP-2 (CXCL2) and RANTES (CCL5) occurred after IR which was also attenuated by ATL313 treatment. Lungs from A_2AAR knockout mice also displayed significant dysfunction, injury and cytokine/chemokine production after IR, but ATL313 had no effect in these mice.</p> <p>Conclusion</p> <p>Specific activation of A_2AARs provides potent protection against lung IR injury via attenuation of inflammation. This protection occurs in the absence of circulating blood thereby indicating a protective role of A_2AAR activation on resident lung cells such as alveolar macrophages. Specific A_2AAR activation may be a promising therapeutic target for the prevention or treatment of pulmonary graft dysfunction in transplant patients.</p