scholarly journals The Sustainability Issue; What Meaning for the Economic and Human Activity?

2020 ◽  
Vol 7 (3) ◽  
pp. 1
Author(s):  
Giovanni Antonio COSSIGA

The sustainability issue, understood as a good relationship between humankind and nature, can offer the opportunity to analyze certain aspects of the economic theory. If we admit that the stability in economy is a natural condition for linear growth and instead the conjuncture is a trouble for growth due to the loss of natural balance, some consequences will follow. The long fight against instability has not been won, always struggling between inflation and deflation. It follows that the fight against inflation first and then deflation couldn’t counter the real malaise of the global economy: the instability. That is the deviation of economic systems from the natural path of balance with nature. Therefore, the results obtained struggling with monetary alterations, although significant, would be temporary and unable to solve the core of the matter. It follows that the economic support policies have essentially addressed the formal aspect, I would say just indicative of the imbalance, without obtaining stable results in the natural balance recovery. From this point of view, the interventions of fiscal policy, despite some good tests obtained by trying to reduce the strength of the 2008-2010 financial crisis, have not solved however the poisonous aftermath of deflation. Moreover, during the last decade, the health of global economic systems has always required, to be maintained, a defense in the form of supporting policies through neo-Keynesian interventions. And not only that. Because the monetary policy used all its weapons, even unconventional ones, to defeat deflation: nonetheless, it didn’t achieve anything but just a mitigation of phenomena. Always provided, anyway, that the wave of new liquidity continues, as requested by the markets. The point is therefore which is the exit strategy from this situation, considering that the progressive exhaustion of the resources of fiscal and monetary policies sets the expectation of a potential progressive recession on a global basis. Well, according to the sustainability theory the recession is not a bad thing in itself, but it’s rather a cure whose impact we must learn to measure, having the view to mitigate the most negative social effects.

2021 ◽  
Vol 13 (2) ◽  
pp. 97
Author(s):  
Giovanni Antonio COSSIGA

To be implemented and analyzed, according to the good rules of relationship with nature, sustainability must be equipped with a theoretical scheme able of helping to understand the dynamics of this relationship together with the opportunities offered to improve the development of the economic system. Essentially, it’s about acknowledging that, just like physics, also the economy is subject to some general and abstract laws. This is the case of the core inflation value, defined by Central Banks as a value close to 2%. So, if the economy moves along the track indicated by this value, we have confirmation that growth is regularly developing. This core inflation value is implicitly defined without a clear specification. We can therefore admit that it’s an ideal value like the great universal constants, which reports about an economic system that develops according to the rules of natural compatibility. According to this point of view, the core inflation close to 2% is essentially a utopia, because it can only be achieved if the global economic growth moves in full accordance with the nature around us. It follows that even if we can verify on field the realization of a base value close to 2%, actually we are not in the best conditions, especially if the global economy is suffering from deflation as today. The deflation, that is the tendency of prices to fall, is part of the complex messages sent by the nature and economic systems to signal that the economy is not doing well and has become unstable. Both inflation and deflation are messages that never contribute to the economic development course, but they are born and evolving in parallel with the appearance of the economic cycle in daily activity. In summary, a mechanism that has the responsibility, by imposing pauses on the system, to reduce the instability of the systems and to facilitate the return to the natural development condition. A correction system based on the economic conjuncture that obviously distinguishes the stability by the way that the economy grows and develops in a linear and constant inclination depending on differentials.


Author(s):  
R. R. Palmer

In 1792, the French Revolution became a thing in itself, an uncontrollable force that might eventually spend itself but which no one could direct or guide. The governments set up in Paris in the following years all faced the problem of holding together against forces more revolutionary than themselves. This chapter distinguishes two such forces for analytical purposes. There was a popular upheaval, an upsurge from below, sans-culottisme, which occurred only in France. Second, there was the “international” revolutionary agitation, which was not international in any strict sense, but only concurrent within the boundaries of various states as then organized. From the French point of view these were the “foreign” revolutionaries or sympathizers. The most radical of the “foreign” revolutionaries were seldom more than advanced political democrats. Repeatedly, however, from 1792 to 1799, these two forces tended to converge into one force in opposition to the French government of the moment.


Mathematics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1434 ◽  
Author(s):  
Wonhee Kim ◽  
Sangmin Suh

For several decades, disturbance observers (DOs) have been widely utilized to enhance tracking performance by reducing external disturbances in different industrial applications. However, although a DO is a verified control structure, a conventional DO does not guarantee stability. This paper proposes a stability-guaranteed design method, while maintaining the DO structure. The proposed design method uses a linear matrix inequality (LMI)-based H∞ control because the LMI-based control guarantees the stability of closed loop systems. However, applying the DO design to the LMI framework is not trivial because there are two control targets, whereas the standard LMI stabilizes a single control target. In this study, the problem is first resolved by building a single fictitious model because the two models are serial and can be considered as a single model from the Q-filter point of view. Using the proposed design framework, all-stabilizing Q filters are calculated. In addition, for the stability and robustness of the DO, two metrics are proposed to quantify the stability and robustness and combined into a single unified index to satisfy both metrics. Based on an application example, it is verified that the proposed method is effective, with a performance improvement of 10.8%.


Data ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 4
Author(s):  
Evgeny Mikhailov ◽  
Daniela Boneva ◽  
Maria Pashentseva

A wide range of astrophysical objects, such as the Sun, galaxies, stars, planets, accretion discs etc., have large-scale magnetic fields. Their generation is often based on the dynamo mechanism, which is connected with joint action of the alpha-effect and differential rotation. They compete with the turbulent diffusion. If the dynamo is intensive enough, the magnetic field grows, else it decays. The magnetic field evolution is described by Steenbeck—Krause—Raedler equations, which are quite difficult to be solved. So, for different objects, specific two-dimensional models are used. As for thin discs (this shape corresponds to galaxies and accretion discs), usually, no-z approximation is used. Some of the partial derivatives are changed by the algebraic expressions, and the solenoidality condition is taken into account as well. The field generation is restricted by the equipartition value and saturates if the field becomes comparable with it. From the point of view of mathematical physics, they can be characterized as stable points of the equations. The field can come to these values monotonously or have oscillations. It depends on the type of the stability of these points, whether it is a node or focus. Here, we study the stability of such points and give examples for astrophysical applications.


Inorganics ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 20
Author(s):  
Antonio A. García-Valdivia ◽  
Estitxu Echenique-Errandonea ◽  
Gloria B. Ramírez-Rodríguez ◽  
José M. Delgado-López ◽  
Belén Fernández ◽  
...  

Two new coordination polymers (CPs) based on Zn(II) and Cd(II) and 1H-indazole-6-carboxylic acid (H2L) of general formulae [Zn(L)(H2O)]n (1) and [Cd2(HL)4]n (2) have been synthesized and fully characterized by elemental analyses, Fourier transformed infrared spectroscopy and single crystal X-ray diffraction. The results indicate that compound 1 possesses double chains in its structure whereas 2 exhibits a 3D network. The intermolecular interactions, including hydrogen bonds, C–H···π and π···π stacking interactions, stabilize both crystal structures. Photoluminescence (PL) properties have shown that compounds 1 and 2 present similar emission spectra compared to the free-ligand. The emission spectra are also studied from the theoretical point of view by means of time-dependent density-functional theory (TD-DFT) calculations to confirm that ligand-centred π-π* electronic transitions govern emission of compound 1 and 2. Finally, the PL properties are also studied in aqueous solution to explore the stability and emission capacity of the compounds.


2021 ◽  
pp. 5-20
Author(s):  
M. V. Ershov

The global economy continues to grow, albeit mainly due to large-scale support measures from governments and regulators. Moreover, the latter are not sure about the prospects for such development, since the economies do not demonstrate the potential for independent growth. As a result, in order to stimulate it, regulators are forced to expand the range of their tools, mechanisms, approaches, otherwise the risks to the stability of the global financial and economic system increase. All this is happening against the background of negative rates, which have become virtually ubiquitous and persist for a long time. New growth records are being set in the stock markets, and their gap from the real economy is growing. A number of sectors are beginning to dominate, forming distortions and bubbles in the markets. In such conditions, the importance of digital money, ecosystems, etc. increases. Moreover, the faster and more efficiently regulators can integrate into these formats, the more successful business, the population, and the economy as a whole will be.


Author(s):  
Л.А. МАРЧЕНКО ◽  
Т.Н. БОКОВИКОВА ◽  
Е.В. ЛИСОВАЯ ◽  
С.А. ИЛЬИНОВА ◽  
Е.П. ВИКТОРОВА

Исследована возможность применения яблочной кислоты (ЯК) в качестве гидратирующего агента для перевода негидратируемых форм фосфолипидов в гидратируемые. Выбор ЯК обусловлен ее стоимостью, которая в 1,5 раза меньше стоимости янтарной кислоты, широко применяемой в качестве гидратирующего агента, а также большей доступностью с точки зрения промышленного производства. Исследование процесса комплексообразования и определение состава комплексных соединений ЯК с ионами кальция и магния осуществляли методом потенциометрического титрования. Установлено, что внесение в раствор ЯК ионов кальция и магния приводит к снижению значений рН, что свидетельствует о наличии комплексообразования в указанных системах. Наиболее устойчивыми являются комплексы ионов кальция и магния с непротонированным лигандом при соотношении Ме2 : лиганд 1 : 1. В процессе комплексообразования ионы Ca2 и Mg2 вытесняют протоны только карбоксильных групп ЯК, которая с ионами кальция образует более устойчивые комплексы, чем с ионами магния. Показано, что устойчивость комплексов ЯК с ионами кальция и магния значительно выше, чем устойчивость комплексов фосфатидилсеринов и фосфатидных кислот с указанными ионами. Использование водных растворов ЯК в качестве гидратирующего агента позволит повысить эффективность процесса гидратации и увеличить выход фосфолипидов и, следовательно, готового продукта лецитина. The possibility of using malic acid (MA) as a hydrating agent for converting non-hydrated forms of phospholipids into hydrated ones has been investigated. The choice of MA is due to its cost, which is 1,5 times less than the cost of succinic acid, as well as greater availability from the point of view of industrial production. The study of the complexation process and determination of the composition of complex compounds of MA with calcium and magnesium ions was carried out by the method of potentiometric titration. It was found that the introduction of calcium and magnesium ions into the MA solution leads to a decrease in pH values, which indicates the presence of complexation in these systems. Complexes of calcium and magnesium ions with an unprotected ligand at a ratio of ME2 : ligand 1 : 1 are the most stable. In the process of complexing, Ca2 and Mg2 ions displace protons only of the carboxyl groups of MA, which forms more stable complexes with calcium ions than with magnesium ions. It is shown that the stability of MA complexes with calcium and magnesium ions is significantly higher than the stability of phosphatidylserine and phosphatidic acid complexes with these ions. Using water solutions of MA as a hydrating agent will increase the efficiency of the hydration process and increase the yield of phospholipids and, consequently, the finished product lecithin.


2013 ◽  
Vol 427-429 ◽  
pp. 257-261
Author(s):  
Li Xia Sun ◽  
Jian Wei Yao ◽  
Fu Guo Hou ◽  
Xin Zhao

In order to investigate self-excited vibration mechanism of wheel-rail lateral contact system, a two DOF elasticity position wheelset lateral vibration model is established which considers the dry friction; the mechanism of the wheelset lateral self-excited vibration is investigated from the energy point of view. It shows that: the bifurcation diagram of this wheel-rail lateral contact system has a supercritical Hopf bifurcation. The energy of self-excited vibration derives from a part of traction energy; the creep rate in the wheel-rail system act as a feedback mechanism in the wheelset lateral self-excited vibration system. The stability of the wheelset self-excited vibration system depends mainly on the total energy removed from and imported into the system.


2007 ◽  
Vol 3 (S249) ◽  
pp. 511-516 ◽  
Author(s):  
Julie Gayon ◽  
Eric Bois

AbstractMulti-planet systems detected until now are in most cases characterized by hot-Jupiters close to their central star as well as high eccentricities. As a consequence, from a dynamical point of view, compact multi-planetary systems form a variety of the general N-body problem (with N ≥ 3), whose solutions are not necessarily known. Extrasolar planets are up to now found in prograde (i.e. direct) orbital motions about their host star and often in mean-motion resonances (MMR). In the present paper, we investigate a theoretical alternative suitable for the stability of compact multi-planetary systems. When the outer planet moves on a retrograde orbit in MMR with respect to the inner planet, we find that the so-called retrograde resonances present fine and characteristic structures particularly relevant for dynamical stability. We show that retrograde resonances and their resources open a family of stabilizing mechanisms involving specific behaviors of apsidal precessions. We also point up that for particular orbital data, retrograde MMRs may provide more robust stability compared to the corresponding prograde MMRs.


2021 ◽  
Vol 295 ◽  
pp. 01029
Author(s):  
Alina Ibragimova ◽  
Yan Wang ◽  
Michail Ivanov

The purpose of this work is to provide information on the development of the infrastructure of the African economy. The study provides statistics on African regions and industries. This article focuses on the forms of economic and social infrastructure, and directs to determine the share development infrastructural in Africa. The Africa has entered an era of devastating change this study shows that with the unfolding economic downturn in the northern economies that have traditionally dominated the global economy. The article provides empirical evidence on how the industrial sectors developed from an economic point of view. The authors believe that infrastructure affects output and productivity directly as a contribution to the production function of other sectors and as part of GDP formation. The article discusses the development of infrastructure for the period 1999-2019 without more detailed dynamics. It also does not explain the main topics developed by the authors. The work provides knowledge on how investments are developing in Africa, how industries have developed, and what is the role of each infrastructure sector in this development. It also shows how different areas of infrastructure work with different successes in creating new paths in the African economy.


Sign in / Sign up

Export Citation Format

Share Document