Efficient management of industrial electric vehicles by means of static and dynamic wireless power transfer systems

Industrial companies are moving toward the electrification of equipment and processes, in line with the broader energy transition taking place across the economy. Particularly, the energy efficiency and, consequently, the reduction of environmental pollution of intralogistics activities have become a competitive element and are now an actual research and development objective. A wireless power transfer is a contactless electrical energy transmission technology based on the magnetic coupling between coils installable under the ground level and a coil mounted under the vehicle floor, and it represents an excellent solution to decrease the demand for batteries by reducing vehicle downtimes during the recharge. This work aims to define a methodology to determine the optimal positioning of wireless charging units across the warehouse, both for static and dynamic recharging. To this aim, firstly, a mathematical model of the warehouse is proposed to describe transfers and storage/retrieval operations executed by the forklifts. Then, an integer linear programming problem is applied to find the best possible layout of the charging infrastructures. The optimal solution respects the energetic requirements given by the customer and minimizes the overall system cost. The proposed approach was applied to optimize the installation in a real-size warehouse of a tire manufacturing company. Several scenarios were computer generated through discrete event simulation in order to test the optimizer in different warehouse conditions. The obtained results show that integrated dynamic and static WPT systems ensure a constant state of charge of the electric vehicles during their operations

Conway games, algebraically and coalgebraically

Using coalgebraic methods, we extend Conway's theory of games to possibly non-terminating, i.e. non-wellfounded games (hypergames). We take the view that a play which goes on forever is a draw, and hence rather than focussing on winning strategies, we focus on non-losing strategies. Hypergames are a fruitful metaphor for non-terminating processes, Conway's sum being similar to shuffling. We develop a theory of hypergames, which extends in a non-trivial way Conway's theory; in particular, we generalize Conway's results on game determinacy and characterization of strategies. Hypergames have a rather interesting theory, already in the case of impartial hypergames, for which we give a compositional semantics, in terms of a generalized Grundy-Sprague function and a system of generalized Nim games. Equivalences and congruences on games and hypergames are discussed. We indicate a number of intriguing directions for future work. We briefly compare hypergames with other notions of games used in computer science.Comment: 30 page

The importance of anisotropic Coulomb interaction in LaMnO3

In low-temperature anti-ferromagnetic LaMnO3, strong and localized electronic interactions among Mn 3d electrons prevent a satisfactory description from standard local density and generalized gradient approximations in density functional theory calculations. Here we show that the strong on-site electronic interactions are described well only by using direct and exchange corrections to the intra-orbital Coulomb potential. Only DFT+U calculations with explicit exchange corrections produce a balanced picture of electronic, magnetic and structural observables in agreement with experiment. To understand the reason, a rewriting of the functional form of the +U corrections is presented that leads to a more physical and transparent understanding of the effect of these correction terms. The approach highlights the importance of Hund’s coupling (intra-orbital exchange) in providing anisotropy across the occupation and energy eigenvalues of the Mn d states. This intra-orbital exchange is the key to fully activating the Jahn-Teller distortion, reproducing the experimental band gap and stabilizing the correct magnetic ground state in LaMnO3. The best parameter values for LaMnO3 within the DFT(PBEsol)+U framework are determined to be U = 8 eV and J = 1.9 eV

The Category of Node-and-Choice Forms, with Subcategories for Choice-Sequence Forms and Choice-Set Forms

The literature specifies extensive-form games in many styles, and eventually I hope to formally translate games across those styles. Toward that end, this paper defines $\mathbf{NCF}$, the category of node-and-choice forms. The category's objects are extensive forms in essentially any style, and the category's isomorphisms are made to accord with the literature's small handful of ad hoc style equivalences. Further, this paper develops two full subcategories: $\mathbf{CsqF}$ for forms whose nodes are choice-sequences, and $\mathbf{CsetF}$ for forms whose nodes are choice-sets. I show that $\mathbf{NCF}$ is "isomorphically enclosed" in $\mathbf{CsqF}$ in the sense that each $\mathbf{NCF}$ form is isomorphic to a $\mathbf{CsqF}$ form. Similarly, I show that $\mathbf{CsqF_{\tilde a}}$ is isomorphically enclosed in $\mathbf{CsetF}$ in the sense that each $\mathbf{CsqF}$ form with no-absentmindedness is isomorphic to a $\mathbf{CsetF}$ form. The converses are found to be almost immediate, and the resulting equivalences unify and simplify two ad hoc style equivalences in Kline and Luckraz 2016 and Streufert 2019. Aside from the larger agenda, this paper already makes three practical contributions. Style equivalences are made easier to derive by [1] a natural concept of isomorphic invariance and [2] the composability of isomorphic enclosures. In addition, [3] some new consequences of equivalence are systematically deduced.Comment: 43 pages, 9 figure

Spatio-Temporal Distribution of Ichthyoplankton in Manila Bay in Relation to Oceanographic Conditions

Manila Bay faces serious problems today such as pollution, coastal area reclamation and infrastructure, overfishing, and other activities that worsen the present condition of the bay. It is considered as one of the major fishing grounds in the Philippines. Fish eggs and larvae collection was carried out to determine their distribution, abundance, and composition in the bay. Eight established sampling stations were placed throughout the bay with an average distance of 5-6 nautical miles apart and sampled every other month on a monsoonal basis. Bongo net (360 microns mesh size, 1.5 meters in length, and a diameter of 50-centimeter mouth opening) with attached calibrated flowmeter was used in collecting fish larvae. Physical (salinity, temperature,), chemical (nitrite, nitrate, phosphate, silicate, dissolved oxygen), and biological (phytoplankton, zooplankton) parameters were also carefully studied to be able to explain such uncommon event within the bay. In spite of the current status and worsening condition of water quality of the bay, high abundances of fish eggs and larvae were consistently observed during the northeast monsoon surveys (March) from 2012 to 2015. A total of 3,008 individuals were identified belonging to 34 fish families. The highest fish egg density was observed during March 2013 with 1,550 ind./100m3, followed by March 2012 and 2015 with 1,484 ind./100m3 and 1,182 ind./100m3, respectively. An abundance of fish larvae was observed during March 2015 with 414 ind./100m3, followed by March 2012 (329 ind./100m3), and March 2014 (311 ind./100m3). The lowest density observed was in September 2012 with a density of 132 ind/100m3 fish eggs and 46 ind/100m3 fish larvae. The results were consistent that most fish eggs aggregate in the middle part of the bay especially in Stations 4 and 2 from 2012-2015. For fish larvae, they were consistently found in the eastern part of the bay (stations 6, 8, and 7) throughout the duration of the study, it was also the areas where high concentrations of phytoplankton, zooplankton, and nutrients were observed. A high abundance of fish eggs and fish larvae was observed during northeast monsoon than southwest monsoon. In addition, fish larvae family was dominated by small pelagic fish such as sardines, slipmouths, and mullets. The most dominant fish families found were Clupeidae, followed Leiognathidae, and Nemipteridae. Sillaginidae and Mugilidae were also included in the top five abundant families that occur during every sampling period were

Profile of Salinity, Temperature, Heavy Metal (Pb, Cd, Hg) and Sediment Hydrogen Sulfide Concentration of Manila Bay, Philippines from 2012 to 2015

The physical parameters of seawater are important determinants of water quality. Heavy metals are components that are naturally present in a considerable amount in the ocean but are observed to be rising above the allowable level due to pollution outputs of industrialization. Heavy metal contamination is among the environmental pollution problems that the world faces. Additionally, hydrogen sulfide (H2S) is also a toxic compound that accumulates in the ocean floor posing threat to the marine organisms when present in high concentrations. The objective of this study is to document the distribution of temperature and salinity in the water column, heavy metals (Pb, Cd, Hg) and sediment H2S in Manila Bay from 2012 to 2015. Stratification in the bay was generally a factor of salinity and less of temperature. Stratification due to salinity was consistently observed in September with the halocline occurring around 10 m to 15 m. Most of the time, the bay had evenly distributed temperatures, but the slightly higher temperatures were usually recorded near the coast. Inverse trends were observed for the salinity and temperature of the bay. Pb, Cd, and Hg concentrations in the bay occasionally exceeded the permissible limits especially the lead concentration in January 2013 (ave: 809.81 µg/L), March 2013 (ave: 1102.88 µg/L) and November 2015 (1507.50 µg/L). Cd and Hg concentrations were generally below the permissible limit and the reported limit of analysis. H2S concentration ranged from < 4 mg/kg to 9.99 mg/kg for all the survey months. Distribution was higher in the northwestern part and southeastern areas of the bay

Spatio-Temporal Variability of Hypoxia and Eutrophication in Manila Bay During the Northeast and Southwest Monsoons from 2012 to 2015

Manila Bay is a major source of livelihood for the fishermen living around the area. The occurrence of hypoxia, a state where dissolved oxygen (DO) is not enough to support marine life, poses a serious threat to the bay and consequently to its fisheries sector. This study documents the variation of hypoxia throughout the bay for a sampling period of four years, from January 2012 to November 2015, with a monthly interval each survey. A total of 24 field surveys on 16 designated sampling stations, at varying depths, were conducted. Results show that hypoxia was present all year round but was more severe during the wet season (July, September, November) compared to the dry season. The averages of bay-wide DO concentration ranged from 3.42 to 7.63mg/l during the 4-year survey. Low DO concentrations were associated with high concentrations of nutrients, particularly nitrate. Nitrate spiked to a 44.6 µM concentration while bay-wide DO concentration dropped to as low as 0.01 mg/l in the wet season. An occurrence of hypoxia along the coasts, transitioning from western, northern and eastern areas, was observed as a common trend for all surveys. However, DO concentrations in areas near the coast, in depths around 5m to 15m, and in the deeper areas near the mouth of the bay, from around 10m to 35m depths were noted to be lower. In conclusion, hypoxia has been occurring year-round in Manila Bay with varying intensity but more prominent during the wet season

Variable Curvature Slab Molecular Dynamics as a Method to Determine Surface Stress

A thin plate or slab, prepared so that opposite faces have different surface stresses, will bend as a result of the stress difference. We have developed a classical molecular dynamics (MD) formulation where (similar in spirit to constant-pressure MD) the curvature of the slab enters as an additional dynamical degree of freedom. The equations of motion of the atoms have been modified according to a variable metric, and an additional equation of motion for the curvature is introduced. We demonstrate the method to Au surfaces, both clean and covered with Pb adsorbates, using many-body glue potentials. Applications to stepped surfaces, deconstruction and other surface phenomena are under study.Comment: 16 pages, 8 figures, REVTeX, submitted to Physical Review

Amphoteric dissolution of two-dimensional polytriazine imide carbon nitrides in water

Crystalline two-dimensional carbon nitrides with polytriazine imide (PTI) structure are shown to act amphoterically, buffering both HCl and NaOH aqueous solutions, resulting in charged PTI layers that dissolve spontaneously in their aqueous media, particularly for the alkaline solutions. This provides a low energy, green route to their scalable solution processing. Protonation in acid is shown to occur at pyridinic nitrogens, stabilized by adjacent triazines, whereas deprotonation in base occurs primarily at basal plane NH bridges, although NH 2 edge deprotonation is competitive. We conclude that mildly acidic or basic pHs are necessary to provide sufficient net charge on the nanosheets to promote dissolution, while avoiding high ion concentrations which screen the repulsion of like-charged PTI sheets in solution. This article is part of the theme issue 'Exploring the length scales, timescales and chemistry of challenging materials (Part 2)'