Polygon vertex extremality and decomposition of polygons

AbstractIn this paper, we show that if we decompose a polygon into two smaller polygons, then by comparing the number of extremal vertices in the original polygon versus the sum of the two smaller polygons, we can gain at most two globally extremal vertices in the smaller polygons, as well as at most two locally extremal vertices. We then will derive two discrete Four-Vertex Theorems from our results

Waste Management Behaviour of Households: A Case Study of a Strike in Saskatchewan

Environmental Economics and Policy,

Time-Domain Finite Elements for Virtual Testing of Electromagnetic Compatibility

The paper presents a time-domain finite-element solver developed for simulations related to solving electromagnetic compatibility issues. The software is applied as a module integrated into a computational framework developed within a FP7 European project High Intensity Radiated Field – Synthetic Environment (HIRF SE) able to simulate a large class of problems. In the paper, the mathematical formulation is briefly presented, and special emphasis is put on the user point of view on the simulation tool-chain. The functionality is demonstrated on the computation of shielding effectiveness of two composite materials. Results are validated through experimental measurements and agreement is confirmed by automatic feature selective algorithms

Winter in a Svalbard Fiord Ecosystem

Data pertaining to the characteristics of an arctic fiord in winter were collected at the Polish Arctic Station situated in Hornsund at 77 degrees N, 15 degrees E on Svalbard. Winter in the fiord was defined in terms of climate (November-May), hydrology (January-March) and biology (November-March). The characteristic phenomena of winter in the fiord include a winter drop in the yearly biomass maximum to 0.1% for phytoplankton and 10% for zooplankton; a slowing of the growth rate among pelagic dominants such as Pseudocalanus elongatus and Calanus finmarchicus, as well as among the hyperbenthic dominants Onisimus littoralis and Mysis oculata; and heterotrophy or maintenance of metabolism among living phytoplankton cells found in the middle of the polar night in densities of 10-50 cells/L. Since the life cycles of invertebrates are highly seasonal, no winter breeders were observed and 90% of the examined species were breeding according to a K strategy. Migration takes place among all seabirds in the area, but about 1% of the eiders, fulmars and kittiwakes overwinter, feeding in the open water of polynyas and crevices in the fast ice.Key words: Arctic, winter ecology, fiord ecosystem, Svalbard, Hornsund fiordMots clés: Arctique, écologie de l’hiver, écosystème de fjord, Svalbard, fjord Hornsun

Charge Localization in Defective BiVO4

We study the native defects in bismuth vanadate using hybrid density functional theory. We pay special attention to where excess charges localize by considering different polaronic distortions and find that charge localization has a profound effect on the local chemical environment around certain defects. In particular, oxygen dimerization may occur in the presence of acceptor defects. On the basis of Fermi level pinning due to compensation between donors and acceptors we additionally find that intrinsic p-type conductivity is difficult to achieve in BiVO4, in good agreement with experimental observations. Our results give new insights into the defect chemistry of bismuth vanadate and act as a guide for future studies on defects in complex metal oxides

Enantiomerically pure β-phenylalanine analogues from α–β-phenylalanine mixtures in a single reactive extraction step

An efficient and selective method for the extraction of α-amino acids in preference over their β-isomers using PdCl2(PPh3)2 was discovered, which enables the separation of product mixtures obtained in the enantioselective enzymatic formation of β-amino acids.