The Effect of the COVID-19 Pandemic on International Stock Exchanges

It is possible to define the concept of risk in various ways. Risk is the deviation possibility of the realized value from the expected value. It has two components, nonsystematic risk and systematic risk. Despite this, pandemics are risk factors that cannot be anticipated. They have deeply affected economies and financial markets under every condition. The importance of the detection of the COVID-19 pandemic comes from the selection of monetary and fiscal policies to be applied by governments during the rehabilitation process of economies. Equity share markets provide important information regarding the future of a company or economy. The reason for this is that the current value of an equity share is dependent on the deducted calculation of the cash flows of the equity share to be provided in the future. The actual price of the equity share is determined according to supply and demand under market conditions.

Digitalization as a driver for supporting PV deployment and cost reduction

Digitalization is providing advantages to all sectors around the world and it can be of relevance also for the photovoltaic (PV) sector. As an example, the current value chain of the European PV sector is often characterized by analogue and fragmented processes that should be overcame to support greater PV deployment. The adoption of a more open and collaborative digital-based approach characterized by data-sharing among different stakeholders and more integrated information thread from the design till O&M can provide direct benefits in optimizing the PV process, increasing performances, and reducing of costs. Therefore, a novel PV Information Management (PIM) approach has been drawn within the European H2020 project “SuperPV”. In accordance with PIM objectives, a workflow for seamlessly transferring data along main PV work-stages has been developed, as well as new digital features to specifically address collaborative approach in the PV sector such as: (i) advanced functionalities introduced in the existing BIMSolar® software for improving the simultaneous design, performance simulation and cost assessment of medium and large PV systems, (ii) a proof-of-concept for aggregating all relevant information into a Digital Twin platform aimed at setting the ground for post-construction management and lifecycle assessment of the whole PV system.

Conceptualization of the Penology System under Islamic Criminal Law

Islam propounds a culture where everybody follows the rules. Islam aims to preserve peace and tranquillity within the society and thus takes all required legal action to ensure the community against disruptive elements. The notion of retribution in Islam is not the primary law of Islam. They are only imposed as a requirement or series and a vindication of the primary structure of Islamic society. Criminal activity within the revered Islamic order of society is not condoned. Islam aims to change the world by changing its human adherents. Shariah law is focused on the individual rights of persons, but those rights only exist within a framework that stresses the rights of other people. Islam is not against the relative culpability of offenders and how circumstances regulate illegal conduct. Islam is the only religion where its laws and regulations are enforced according to a particular set of laws and regulations. Islam uses a system of proportional punishment. Islamic punishments are entirely justified because Islam takes complete steps to deter crime and inculcates offenders' moral conduct. The Islamic Criminal law has accepted several crimes by offering deterrence, reformative, retaliate and other kinds of punishments to uphold harmony in the community and rehabilitate the offenders. This paper focuses on the Islamic penology and the concept of crime and their punishment and explores its social, historical, and current value

Determination of meridian position by a two-step ground gyrocompass in eesthetical rotor positioning

Contradiction between accuracy and time of definition of a plane of a geographical meridian has significantly weakened with appearance of automatic gyrocompasses and algorithmic methods of processing of the information from them. These methods allow us to expand the range of possible modes of gyrocompasses, including non-traditional. The article considers an automatic two-stage ground gyro compass operating in the mode of natural stopping of the rotor after its pulse acceleration by non-electrical means (squib , compressed air, etc.). The specified mode is attractive because it allows to identify uncontrolled harmful moment around the axis of suspension in one start and significantly reduce the measurement time. In order to further improve the device, it is proposed to abandon the measurement of the current value of the kinetic moment, and to identify the decay coefficient of the exponential function by observing the azimuthal motion of the sensitive element of the device. Moreover, the paper shows that it is possible not to measure the initial value of the kinetic momentum, replacing the measurement with identification of this parameter by observing the same azimuthal motion of the sensitive element. In this case there is no need to have on the sensitive element any nodes associated with the transmission of power and electrical signals, the sensitive element can be made as a purely mechanical element, carrying on itself a rotating rotor. For all considered variants of measurement (or identification) of parameters the machine simulation was carried out, which confirmed the performance of the proposed methodology.

Retrieval of High Added Value Natural Bioactive Coumarins from Mandarin Juice-Making Industrial Byproduct

Cold pressed essential oil (CPEO) of mandarin (Citrus reticulata Blanco), a by-product of the juice-making industrial process known to contain large amounts of polymethoxyflavones, was exploited for its content in high added value natural coumarins. The study herein afforded a method referring to the evaporation of CPEO volatile fraction under mild conditions (reduced pressure and temperature below 35 °C) as azeotrope with isopropanol. This allowed the isolation of high added value coumarins from the non-volatile fragment using preparative High Performance Liquid Chromatography (HPLC). Pilot-scale application of this procedure afforded for each kg of CPEO processed the following natural bioactive coumarins in chemically pure forms: heraclenol (38–55 mg), 8-gerayloxypsoralen (35–51 mg), auraptene (22–33 mg), and bergamottin (14–19 mg). The structures of coumarins were verified by Nuclear Magnetic Resonance (NMR) spectroscopy and HPLC co-injection with authentic standards. Thus, the low market value mandarin CPEO with current value of 17 to 22 EUR/kg can be valorized through the production of four highly bioactive natural compounds worth 3479 to 5057 EUR/kg, indicating the great potentials of this methodology in the terms of the circular economy.

METHOD OF CONTROLLING PRESENCE OF FOREIGN SUBSTANCES AND OBJECTS IN THE BORE OF THE BARREL USING MONOCHROME LIGHT

In the article, the authors propose a method for controlling the presence of foreign substances and objects inside the barrel. The problem of surface cleanliness control remains relevant in many areas, ranging from sanitary cleaning to nanoelectronics. In the military sphere, this becomes particularly important during the cleaning of cannon barrels. Both powder combustion products and cartridge cap and bullet shell particles are deposited in the barrel during firing from guns. Under the impact of high temperatures, the bullet particles are partially oxidized and cover the barrel channel with a thin layer of deposit of oxides, which are difficult to dissolve. As a result, the density of the bullet abuting the walls changes. This affects the characteristics of its motion inside the barrel. The accuracy of the shot is reduced, and subsequently the precision and accuracy of shooting in general decreases. The essence of the proposed method consists in the fact that a light source is placed in the bore of the barrel on one side, and an optical device is placed on the other side, with the help of which the presence of foreign substances and objects is monitored. Unlike the known methods, this method is characterized in that several monochrome light sources in addition are placed in turn in the bore of the barrel from the breech part, and in the bore of the barrel from the muzzle part there is equipment for receiving (detecting) monochrome light. Then, obtained monochrome light is analyzed, current value of its defined parameters is determined. At the next stage, parameter values of monochrome light fixed during control are compared with parameter values of reference signatures, which had been obtained before the barrel was put in service. These values are stored in equipment memory. If the values of at least one of the parameters from at least one of the monochrome light sources are found to be inconsistent with the parameters of the reference signatures, the equipment for receiving and analyzing monochrome light gives a signal about the presence of foreign substances and objects in the bore of the barrel.

Dynamic Modeling of a Proton-Exchange Membrane Fuel Cell Using a Gaussian Approach

This paper proposes a Gaussian approach for the proton-exchange membrane fuel cell (PEMFC) model that estimates its voltage behavior from the operating current value. A multi-parametric Gaussian model and an unconstrained optimization formulation based on a conventional non-linear least squares optimizer is mainly considered. The model is tested using experimental data from the Ballard Nexa 1.2 kW fuel cell (FC). This methodology offers a promising approach for static and current-voltage, characteristic of the three regions of operation. A statistical study is developed to evaluate the effectiveness and superiority of the proposed FC Gaussian model compared with the Diffusive Global model and the Evolution Strategy. In addition, an approximation to the exponential function for a Gaussian model simplification can be used in systems that require real-time emulators or complex long-time simulations.

Computing the Atom Graph of a Graph and the Union Join Graph of a Hypergraph

The atom graph of a graph is a graph whose vertices are the atoms obtained by clique minimal separator decomposition of this graph, and whose edges are the edges of all possible atom trees of this graph. We provide two efficient algorithms for computing this atom graph, with a complexity in O(min(nωlogn,nm,n(n+m¯)) time, where n is the number of vertices of G, m is the number of its edges, m¯ is the number of edges of the complement of G, and ω, also denoted by α in the literature, is a real number, such that O(nω) is the best known time complexity for matrix multiplication, whose current value is 2,3728596. This time complexity is no more than the time complexity of computing the atoms in the general case. We extend our results to α-acyclic hypergraphs, which are hypergraphs having at least one join tree, a join tree of an hypergraph being defined by its hyperedges in the same way as an atom tree of a graph is defined by its atoms. We introduce the notion of union join graph, which is the union of all possible join trees; we apply our algorithms for atom graphs to efficiently compute union join graphs.

On the Thermal Dynamics of Metallic and Superconducting Wires. Bifurcations, Quench, the Destruction of Bistability and Temperature Blowup

In the present study, a numerical bifurcation analysis is carried out in order to investigate the multiplicity and the thermal runaway features of metallic and superconducting wires in a unified framework. The analysis reveals that the electrical resistance, combined with the boiling curve, are the dominant factors shaping the conditions of bistability—which result in a quenching process—and the conditions of multistability—which may lead to a temperature blowup in the wire. An interesting finding of the theoretical analysis is that, for the case of multistability, there are two ways that a thermal runaway may be triggered. One is associated with a high current value (“normal” runaway) whereas the other one is associated with a lower current value (“premature” runaway), as has been experimentally observed with certain types of superconducting magnets. Moreover, the results of the bifurcation analysis suggest that a static criterion of a warm or a cold thermal wave propagation may be established based on the limit points obtained.