Maritime Climate in the Canary Islands and its Implications for the Construction of Coastal Infrastructures

Islands are isolated systems that depend on maritime trade for their subsistence. Efficient, durable and structurally reliable port infrastructures are essential for the economic and social development of islands. However, not all port infrastructures are designed in the same way. They can vary, depending on whether they are built on continental land, built on non-volcanic islands or built on volcanic oceanic islands (such as the Canary Islands, Spain). The latter islands are the subject of this study due to their specific features, construction difficulties and the importance of sound maritime infrastructures. The maritime climate of an area consists of the wave and storm regimes that affect it and, from these, the coastal dynamics and coastal formations of that area can be studied. For this reason, historical data were collated on significant directional wave heights from 1958 to 2015 from several WANA-SIMAR points in the virtual buoy network of State Ports of Spain located near the Canary Islands. These data have been studied to obtain the maximum directional wave heights (Hs) at each point. With this analysis, we have obtained useful summary tables to calculate wave height by a graphic method that transforms the distribution function into a line drawn on probabilistic paper, using reduced variables. This enables adjustments to be made by linear regression and minimum square methods to facilitate planning and design of maritime infrastructures in a reliable way. Doi: 10.28991/CEJ-2022-08-01-02 Full Text: PDF

Valuation of Distributed Wind in an Isolated System

Remote communities are increasingly adopting renewable energy, such as wind, as they transition away from diesel energy generation. It is important to understand the benefits and costs of wind energy to isolated systems so that decision-makers can optimize their choices in these communities. There are few examples of valuation of wind energy as a distributed resource and numerous differences in valuation approaches, especially in the inclusion of environmental and economic impacts. We apply a distributed wind valuation framework to calculate the benefits and costs of wind in St. Mary’s, Alaska, to the local electric cooperative and to society, finding that the project does not have a favorable benefit-to-cost ratio unless societal benefits are included, in which case the benefit-to-cost ratio is nearly double. Government funding is important to reducing the initial capital expenditures of this wind project and will likely be the case for projects with similar characteristics. Additional fuel savings benefits are potentially possible for this project through technological additions such as energy storage and advanced controls.

Understanding entropy

A new way of understanding entropy as a macroscopic property is presented. This is based on the fact that heat flows from a hot body to a cold one even when the hot one is smaller and has less energy. A quantity that determines the direction of flow is shown to be the increment of heat gained (q) divided by the absolute temperature (T). The same quantity is shown to determine the direction of other processes taking place in isolated systems provided that q is determined by the state (s) of the system. Entropy emerges as the potent energy of a system [Σ(qs/T)], the potency being determined by 1/T. This is shown to tie in with the statistical mechanical interpretation of entropy. The treatment is shorter than the traditional one based on heat engines.

Multipartite entanglement of billions of motional atoms heralded by single photon

Quantum theory does not prevent entanglement from being created and observed in macroscopic physical systems, in reality however, the accessible scale of entanglement is still very limited due to decoherence effects. Recently, entanglement has been observed among atoms from thousands to millions levels in extremely low-temperature and well isolated systems. Here, we create multipartite entanglement of billions of motional atoms in a quantum memory at room temperature and certify the genuine entanglement via M-separability witness associated with photon statistics. The information contained in a single photon is found strongly correlated with the excitation shared by the motional atoms, which intrinsically address the large system and therefore stimulate the multipartite entanglement. Remarkably, our heralded and quantum memory built-in entanglement generation allows us to directly observe the dynamic evolution of entanglement depth and further to reveal the effects of decoherence. Our results verify the existence of genuine multipartite entanglement among billions of motional atoms at ambient conditions, significantly extending the boundary of the accessible scale of entanglement.

Compact Galvanically Isolated Architectures for Low-Power DC-DC Converters with Data Transmission

This paper reviews state-of-the-art architectures for galvanically isolated DC–DC converters with data transmission for low-power applications. Such applications do not have stringent requirements, in terms of power efficiency, but ask for very compact, highly integrated implementations. To this aim, architecture simplicity is crucial, especially when data transmission and/or output power regulation are required. Since the bottleneck of galvanically isolated systems is the isolation device (i.e., typically a stacked thick oxide or polyimide transformer), the reduction of the number of isolated links, while preserving both power and data functionalities, is the more effective strategy to increase the level of integration, reduce the form factor, and have a lower cost per channel. Specifically, this review compares the pros and cons of different architectures that address this challenge differently from traditional solutions.

On center of mass and foliations by constant spacetime mean curvature surfaces for isolated systems in General Relativity

We propose a new foliation of asymptotically Euclidean initial data sets by 2-spheres of constant spacetime mean curvature (STCMC). The leaves of the foliation have the STCMC-property regardless of the initial data set in which the foliation is constructed which asserts that there is a plethora of STCMC 2-spheres in a neighborhood of spatial infinity of any asymptotically flat spacetime. The STCMC-foliation can be understood as a equivariant relativistic generalization of the CMC-foliation suggested by Huisken and Yau (Invent Math 124:281–311, 1996). We show that a unique STCMC-foliation exists near infinity of any asymptotically Euclidean initial data set with non-vanishing energy which allows for the definition of a new notion of total center of mass for isolated systems. This STCMC-center of mass transforms equivariantly under the asymptotic Poincaré group of the ambient spacetime and in particular evolves under the Einstein evolution equations like a point particle in Special Relativity. The new definition also remedies subtle deficiencies in the CMC-approach to defining the total center of mass suggested by Huisken and Yau (Invent Math 124:281–311, 1996) which were described by Cederbaum and Nerz (Ann Henri Poincaré 16:1609–1631, 2015).

ENVIRONMENTAL SAFETY AND SUSTAINABLE DEVELOPMENT

The article is devoted to the actual problem of our time-the legislative provision of environmental safety in the framework of achieving sustainable development. The very essence of the concept of environmental security is to create a collective, universal security system that unites all the states of the planet. This means that it is unacceptable to strengthen the security of some States at the expense of others, and it is not advisable to create isolated systems of environmental security. Environmental security, as well as political security, is equal and indivisible for all subjects of international law.

Organization of land use in a market economy

The influence of the forms of ownership of land and organizational and legal forms of management on the system of on-farm organization of land use is considered. The unified and isolated systems of land use organization and its influence on the solution of individual land management problems are substantiated. The content of the stages of land management is shown depending on the organization of the land and property complex in agricultural organizations.