scholarly journals On the Dominant Lunisolar Perturbations for Long-Term Eccentricity Variation: The Case of Molniya Satellite Orbits

Universe ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 482
Author(s):  
Tiziana Talu ◽  
Elisa Maria Alessi ◽  
Giacomo Tommei
Keyword(s):  
Situational Awareness ◽  
Point Of View ◽  
Elliptical Orbit ◽  
Life Strategy ◽  
Satellite Orbits ◽  
Orbital Eccentricity ◽  
Dominant Term ◽  
Lunisolar Perturbations ◽  
Averaged Model

The aim of this work is to investigate the main dominant terms of lunisolar perturbations that affect the orbital eccentricity of a Molniya satellite in the long term. From a practical point of view, these variations are important in the context of space situational awareness—for instance, to model the long-term evolution of artificial debris in a highly elliptical orbit or to design a reentry end-of-life strategy for a satellite in a highly elliptical orbit. The study assumes a doubly averaged model including the Earth’s oblateness effect and the lunisolar perturbations up to the third-order expansion. The work presents three important novelties with respect to the literature. First, the perturbing terms are ranked according to their amplitudes and periods. Second, the perturbing bodies are not assumed to move on circular orbits. Third, the lunisolar effect on the precession of the argument of pericenter is analyzed and discussed. As an example of theoretical a application, we depict the phase space description associated with each dominant term, taken as isolated, and we show which terms can apply to the relevant dynamics in the same region.

scholarly journals Semianalytic Integration of High-Altitude Orbits under Lunisolar Effects

2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
Martin Lara ◽  
Juan F. San Juan ◽  
Luis M. López
Keyword(s):  
High Altitude ◽  
Disturbing Function ◽  
Orbital Eccentricity ◽  
Lunisolar Perturbations ◽  
Long Term Effect ◽  
Orbit Eccentricity ◽  
Double Averaging ◽  
Earth’S Oblateness ◽  
Truncation Order

The long-term effect of lunisolar perturbations on high-altitude orbits is studied after a double averaging procedure that removes both the mean anomaly of the satellite and that of the moon. Lunisolar effects acting on high-altitude orbits are comparable in magnitude to the Earth’s oblateness perturbation. Hence, their accurate modeling does not allow for the usual truncation of the expansion of the third-body disturbing function up to the second degree. Using canonical perturbation theory, the averaging is carried out up to the order where second-order terms in the Earth oblateness coefficient are apparent. This truncation order forces to take into account up to the fifth degree in the expansion of the lunar disturbing function. The small values of the moon’s orbital eccentricity and inclination with respect to the ecliptic allow for some simplification. Nevertheless, as far as the averaging is carried out in closed form of the satellite’s orbit eccentricity, it is not restricted to low-eccentricity orbits.

Selective statistical estimates of multi-year monthly concentrations of biogenous pollution of small rivers of the Northwest zone of the Russian Federation

2020 ◽  
pp. 9-13
Author(s):  
Sergey Kovalenko
Keyword(s):  
Statistical Processing ◽  
Point Of View ◽  
Small Rivers ◽  
Statistical Parameters ◽  
Monthly Data ◽  
Statistical Estimates ◽  
Scientific Task ◽  
The Russian Federation ◽  
Agricultural Areas

The management of surface watercourses is an urgent scientific task. The article presents the results of statistical processing of long-term monthly data of field observations of hydrological and hydrochemical parameters along the Upper Yerga small river in the Vologda region. Sampling estimates of statistical parameters are obtained, autocorrelation and correlation analyzes are performed. The limiting periods from the point of view of pollution for water receivers receiving wastewater from drained agricultural areas are identified.

Masonry: the brittle or plastic material?

2019 ◽  
pp. 22-28
Keyword(s):  
Plastic Material ◽  
Experimental Studies ◽  
Point Of View ◽  
Plastic Properties ◽  
Plastic Deformations ◽  
Base Materials ◽  
Stress States ◽  
Creep Deformations ◽  
Structural Point

The results of experimental studies of masonry on the action of dynamic and static (short-term and long-term) loads are presented. The possibility of plastic deformations in the masonry is analyzed for different types of force effects. The falsity of the proposed approach to the estimation of the coefficient of plasticity of masonry, taking into account the ratio of elastic and total deformations of the masonry is noted. The study of the works of Soviet scientists revealed that the masonry under the action of seismic loads refers to brittle materials in the complete absence of plastic properties in it in the process of instantaneous application of forces. For the cases of uniaxial and plane stress states of the masonry, data on the coefficient of plasticity obtained from the experiment are presented. On the basis of experimental studies the influence of the strength of the so-called base materials (brick, mortar) on the bearing capacity of the masonry, regardless of the nature of the application of forces and the type of its stress state, is noted. The analysis of works of prof. S. V. Polyakov makes it possible to draw a conclusion that at the long application of the load, characteristic for the masonry are not plastic deformations, but creep deformations. It is shown that the proposals of some authors on the need to reduce the level of adhesion of the mortar to the brick for the masonry erected in earthquake-prone regions in order to improve its plastic properties are erroneous both from the structural point of view and from the point of view of ensuring the seismic resistance of structures. It is noted that the proposal to assess the plasticity of the masonry of ceramic brick walls and large-format ceramic stone with a voidness of more than 20% is incorrect, and does not meet the work of the masonry of hollow material. On the basis of the analysis of a large number of research works it is concluded about the fragile work of masonry.

Integrating Focusing and Differentiation: A Therapeutic Path for Couples in Intimate Relationships

2018 ◽  
Vol 3 ◽  
Author(s):  
Evi Zohar
Keyword(s):  
Couples Therapy ◽  
Therapeutic Potential ◽  
Well Being ◽  
Point Of View ◽  
The Body ◽  
Self Awareness ◽  
Emotional Healing ◽  
Felt Sense ◽  
Inner World

Continuing the workshop I've given in the WPC Paris (2017), this article elaborates my discussion of the way I interlace Focusing with Differentiation Based Couples Therapy (Megged, 2017) under the systemic view, in order to facilitate processes of change and healing in working with intimate couples. This article presents the theory and rationale of integrating Differentiation (Bowen, 1978; Schnarch, 2009; Megged, 2017) and Focusing (Gendlin, 1981) approaches, and its therapeutic potential in couple's therapy. It is written from the point of view of a practicing professional in order to illustrate the experiential nature and dynamics of the suggested therapeutic path. Differentiation is a key to mutuality. It offers a solution to the central struggle of any long term intimate relationship: balancing two basic life forces - the drive for individuality and the drive for togetherness (Schnarch, 2009). Focusing is a body-oriented process of self-awareness and emotional healing, in which one learns to pay attention to the body and the ‘Felt Sense’, in order to unfold the implicit, keep it in motion at the precise pace it needs for carrying the next step forward (Gendlin, 1996). Combining Focusing and Differentiation perspectives can cultivate the kind of relationship where a conflict can be constructively and successfully held in the inner world of each partner, while taking into consideration the others' well-being. This creates the possibility for two people to build a mutual emotional field, open to changes, permeable and resilient.

Configurations to Superior Environmental Innovation Strategy: A Both–And Approach

2021 ◽  
pp. 108602662110316
Author(s):  
Tiziana Russo-Spena ◽  
Nadia Di Paola ◽  
Aidan O’Driscoll
Keyword(s):  
Climate Change ◽  
Value Chain ◽  
Critical Role ◽  
Well Being ◽  
Point Of View ◽  
Future Generations ◽  
Innovation Strategy ◽  
Environmental Innovation ◽  
Data Set

An effective climate change action involves the critical role that companies must play in assuring the long-term human and social well-being of future generations. In our study, we offer a more holistic, inclusive, both–and approach to the challenge of environmental innovation (EI) that uses a novel methodology to identify relevant configurations for firms engaging in a superior EI strategy. A conceptual framework is proposed that identifies six sets of driving characteristics of EI and two sets of beneficial outcomes, all inherently tensional. Our analysis utilizes a complementary rather than an oppositional point of view. A data set of 65 companies in the ICT value chain is analyzed via fuzzy-set comparative analysis (fsQCA) and a post-QCA procedure. The results reveal that achieving a superior EI strategy is possible in several scenarios. Specifically, after close examination, two main configuration groups emerge, referred to as technological environmental innovators and organizational environmental innovators.

scholarly journals Influence of the socio-economic environment on the entrepreneurs behavior. Cases of cuba and ecuador

2021 ◽  
Vol 13 ◽  
pp. 184797902199450
Author(s):  
Reyner Pérez-Campdesuñer ◽  
Gelmar García-Vidal ◽  
Alexander Sánchez-Rodríguez ◽  
Rodobaldo Martínez-Vivar ◽  
Margarita de Miguel-Guzmán ◽  
...  
Keyword(s):  
Comparative Study ◽  
Point Of View ◽  
Personality Characteristics ◽  
Social Model ◽  
Historical Evolution ◽  
Government Regulations ◽  
Failure Risk ◽  
Short And Long Term ◽  
Financial Environment

Entrepreneurship is an important part of any economy today regardless of its level of development. However, not in all contexts do entrepreneurs operate in the same way, nor are they motivated by the same factors. This research seeks to identify possible coincidence factors and differences between entrepreneurs that operate in different contexts from the point of view of their historical evolution, the duration of these and the economic and social model applied in the countries. Specifically, a comparative study is carried out between entrepreneurs from the republics of Ecuador and Cuba considering various variables such as: personality characteristics (attitude to failure, risk, perseverance and innovation), use of the available time fund for work in entrepreneurship; Impact of the environment in relation to: government regulations, taxes, level of competition and availability of suppliers, as well as the structure of personal expenses projected in the short and long term that entrepreneurs assume as a stimulus for their actions. For the development of the study, a description of the behavior of the variables was initially made and later, by hypothesis testing, to verify differences and similarities between both populations. The study allowed us to identify common and divergent aspects between both populations analyzed. Similarly, it showed how differences in the administrative and financial environment in which entrepreneurs operate generate changes in their priorities and projections.

scholarly journals Sustaining Rice Production through Biofertilization with N2-Fixing Cyanobacteria

2021 ◽  
Vol 11 (10) ◽  
pp. 4628
Author(s):  
Macarena Iniesta-Pallarés ◽  
Consolación Álvarez ◽  
Francisco M. Gordillo-Cantón ◽  
Carmen Ramírez-Moncayo ◽  
Pilar Alves-Martínez ◽  
...  
Keyword(s):  
Agricultural Practices ◽  
Vital Role ◽  
Rice Production ◽  
Point Of View ◽  
Paddy Fields ◽  
Nitrogen Fertilizers ◽  
Trophic Chain ◽  
Agricultural Practice ◽  
Biotechnological Potential

Current agricultural productivity depends on an exogenous nutrient supply to crops. This is of special relevance in cereal production, a fundamental part of the trophic chain that plays a vital role in the human diet. However, our agricultural practices entail highly detrimental side-effects from an environmental point of view. Long-term nitrogen fertilization in croplands results in degradation of soil, water, and air quality, producing eutrophication and subsequently contributing to global warming. In accordance with this, there is a biotechnological interest in using nitrogen-fixing microorganisms to enhance crop growth without adding chemically synthesized nitrogen fertilizers. This is particularly beneficial in paddy fields, where about 60% of the synthetic fertilizer that has been applied is dissolved in the water and washed away. In these agricultural systems, N2-fixing cyanobacteria show a promising biotechnological potential as biofertilizers, improving soil fertility while reducing the environmental impact of the agricultural practice. In the current study, Andalusian paddy fields have been explored to isolate N2-fixing cyanobacteria. These endogenous microorganisms have been subsequently re-introduced in a field trial in order to enhance rice production. Our results provide valuable insights regarding the use of an alternative natural source of nitrogen for rice production.

Dilatation of Vascular Prostheses in Ascending Aortic Position: A Long-Term Follow-Up Computed Tomography Study with Comparison of Different Measurement Methods

2016 ◽  
Vol 66 (03) ◽  
pp. 206-214
Author(s):  
Matthias Endlich ◽  
Christian Krämer ◽  
Chris Probst ◽  
Armin Welz ◽  
Kai Wilhelm ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Measurement Methods ◽  
Point Of View ◽  
Cross Sectional ◽  
Vascular Prostheses ◽  
Aortic Replacement ◽  
Ascending Aortic Replacement ◽  
Long Term Follow Up ◽  
Methods Of Measurement

Background The aim of this study was to evaluate long-term dilatation of Hemashield Gold and Hemashield Platinum vascular prostheses in ascending aortic position using different measurement methods to obtain precise results. Methods Between 1999 and 2007, 73 patients with Stanford type A dissection received ascending aortic replacement with Hemashield Gold and Hemashield Platinum prostheses. Measurements were performed using multiplanar reconstruction mode of electrocardiogram (ECG)-gated, multislice spiral computed tomography (MSCT) in strictly orthogonal cross-sectional planes. Different methods of measurement were compared and maximum dilatation was estimated for different time spans. Results Diameters calculated from the measured circumference showed a significant (p = 0.037) but clinically not relevant difference (0.1 mm) to the mean between the largest and the shortest cross-sectional diameter of the prosthesis. Dilatation after 24.2 ± 10.2 months was 8.5 ± 4.5%. Long-term dilatation after 91.8 ± 34 months amounted to 11.8 ± 4.2%. Conclusion Based on ECG-gated MSCT images, the presented methods of measurement provided reliable results. Long-term analysis shows low dilatation rates for Hemashield prostheses, which therefore can be considered as safe from this point of view. Nevertheless, a maximal dilatation of 20% could be relevant in valve sparing root replacement. It remains unclear if a dilatation like this contributes to the formation of suture aneurysms.

scholarly journals Dog Tethering in Slovakia: Legal, Ethical and Behavioral Aspects and Dog Welfare Implications

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 594
Author(s):  
Daniela Takáčová ◽  
Lenka Skurková ◽  
Lýdia Mesarčová ◽  
Lenka Lešková ◽  
Lucia Kottferová ◽  
...  
Keyword(s):  
Public Safety ◽  
Basic Needs ◽  
Point Of View ◽  
Animal Protection ◽  
Legal Rules ◽  
Behavioral Aspects ◽  
Welfare Implications ◽  
Individual Features ◽  
Physical Comfort

Long-term tethering of dogs, or their keeping under unsuitable conditions can result in issues related to changes in their behavior as they may not satisfy their basic needs of life. These needs are discussed in this paper, along with cases when dogs unnecessarily have to endure cruelty and pain. The unavoidable tethering of a dog must not cause trauma and must be arranged in a way that it guarantees physical comfort. Failure to meet the basic needs of an animal may result in manifestation of fear and subsequent aggressiveness. Owners of animals are responsible for their life and health, and their obligations include eliminating the possibility of them hurting themselves or other beings. The relevant adopted legislative provisions should provide protection to animals and be enforceable, which currently appears rather difficult. Controlling and observation of the legislative provisions related to the tethering of dogs raises some difficulties for animal protection inspectors. It is necessary to focus on the specificities of keeping conditions of various dog breeds and on their individual features. Based on research and the relevant Slovak legislative provisions, this paper discusses various views on the practice of tethering dogs from the point of view of public safety and the ethical consequences of permanent dog tethering. Data on dog tethering in Slovakia were evaluated based on a survey and Slovak legal rules governing this issue were analyzed along with various views of public safety and the ethical consequences of permanent dog tethering.

scholarly journals Assessment of Long-Term Fermentability of PHA-Based Materials from Pure and Mixed Microbial Cultures for Potential Environmental Applications

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 897
Author(s):  
Neda Amanat ◽  
Bruna Matturro ◽  
Marta Maria Rossi ◽  
Francesco Valentino ◽  
Marianna Villano ◽  
...  
Keyword(s):  
Environmental Remediation ◽  
Volatile Fatty Acids ◽  
Rapid Onset ◽  
Pilot Scale ◽  
Point Of View ◽  
Microbial Cultures ◽  
Extraction And Purification ◽  
Fermentation Pattern ◽  
Mixed Microbial Cultures

The use of polyhydroxyalkanoates (PHA) as slow-release electron donors for environmental remediation represents a novel and appealing application that is attracting considerable attention in the scientific community. In this context, here, the fermentation pattern of different types of PHA-based materials has been investigated in batch and continuous-flow experiments. Along with commercially available materials, produced from axenic microbial cultures, PHA produced at pilot scale by mixed microbial cultures (MMC) using waste feedstock have been also tested. As a main finding, a rapid onset of volatile fatty acids (VFA) production was observed with a low-purity MMC-deriving material, consisting of microbial cells containing 56% (on weight basis) of intracellular PHA. Indeed, with this material a sustained, long-term production of organic acids (i.e., acetic, propionic, and butyric acids) was observed. In addition, the obtained yield of conversion into acids (up to 70% gVFA/gPHA) was higher than that obtained with the other tested materials, made of extracted and purified PHA. These results clearly suggest the possibility to directly use the PHA-rich cells deriving from the MMC production process, with no need of extraction and purification procedures, as a sustainable and effective carbon source bringing remarkable advantages from an economic and environmental point of view.

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