Search results for "complex"

Macrobiotus naginae sp. nov., a New Xerophilous Tardigrade Species from Rokua Sand Dunes (Finland)

2022

Animals that colonize soil show specific adaptations to soil. Compared to closely related species living on the surface, the limbs of soil-dwelling animals are often shortened, reduced, or absent to allow a less restricted passage through cavities between soil particles. This pattern of limb reduction has also been observed in tardigrades, where multiple lineages that colonized the below-ground habitat show independent reduction and/or loss of legs and claws. In the tardigrade superfamily Macrobiotoidea, leg and claw reductions are a common trait found in the Macrobiotus pseudohufelandi complex. This rarely found species complex currently contains four nominal taxa. Here we describe, with t…

INVESTIGATION, REALIZATION, AND ENTANGLEMENT CHARACTERIZATION OF COMPLEX OPTICAL QUANTUM STATES

2020

Lignin recovery from spent alkaline pulping liquors using acidification, membrane separation, and related processing steps: A Review

2019

The separation of lignin from the black liquor generated during alkaline pulping is reviewed in this article with an emphasis on chemistry. Based on published accounts, the precipitation of lignin from spent pulping liquor by addition of acids can be understood based on dissociation equilibria of weak acid groups, which affects the solubility behavior of lignin-related chemical species. Solubility issues also govern lignin separation technologies based on ultrafiltration membranes; reduction in membrane permeability is often affected by conditions leading to decreased solubility of lignin decomposition products and the presence of colloidal matter. Advances in understanding of such phenomen…

Comment on “Crystallographic Snapshot of an Arrested Intermediate in the Biomimetic Activation of CO2”

2015

Out of focus: A recent Communication published in this journal describes the synthesis of [nBu4 N]HCO3 . The authors performed a single-crystal X-ray study that revealed a putative species described as an incipient hydroxide ion engaging in a long, and presumably weak, interaction with CO2 . Our recent exploration of the coordination chemistry of CO2 with small ions leads us to believe that such an exceptional bonding situation is unlikely. Instead, we argue that the crystal structure is that of [nBu4 N]O2 CCH3 and therefore not representative of the bulk powder from the synthesis.

Side‐on Coordination in Isostructural Nitrous Oxide and Carbon Dioxide Complexes of Nickel

2021

Abstract A nickel complex incorporating an N2O ligand with a rare η2‐N,N′‐coordination mode was isolated and characterized by X‐ray crystallography, as well as by IR and solid‐state NMR spectroscopy augmented by 15N‐labeling experiments. The isoelectronic nickel CO2 complex reported for comparison features a very similar solid‐state structure. Computational studies revealed that η2‐N2O binds to nickel slightly stronger than η2‐CO2 in this case, and comparably to or slightly stronger than η2‐CO2 to transition metals in general. Comparable transition‐state energies for the formation of isomeric η2‐N,N′‐ and η2‐N,O‐complexes, and a negligible activation barrier for the decomposition of the lat…

Structurally simple complexes of CO2

2015

The ability to bind CO2 through the formation of low-energy, easily-broken, bonds could prove invaluable in a variety of chemical contexts. For example, weak bonds to CO2 would greatly decrease the cost of the energy-intensive sorbent-regeneration step common to most carbon capture technologies. Furthermore, exploration of this field could lead to the discovery of novel CO2 chemistry. Reduction of complexed carbon dioxide might generate chemical feedstocks for the preparation of value-added products, particularly transportation fuels or fuel precursors. Implementation on a large scale could help to drastically reduce CO2 concentrations in the atmosphere. However, literature examples of weak…

Придворные королевские церемонии и их рецепция в праздничной жизни Речи Посполитой

2020

The author traces the transition of the royal court of the Polish-Lithuanian Commonwealth to the Western European model of court ceremonies, which lasted for almost two centuries, from the sixteenth to the eighteenth centuries. Initially, they followed the ceremonial models of the House of Habsburg and, starting in the 1640s, the French ceremonial, refined at the Versailles of Louis XIV. Meant to extol the monarch in the eyes of subjects, such ceremonies became widespread under kings of the House of Vasa, Michał Korybut Wiśniowiecki, Jan III Sobieski, and the House of Wettin. Many etiquette elements and ceremonial patterns were borrowed and adapted to the needs of the wealthy Polish and Lit…

Świadczenia diabetologiczne w województwie śląskim w latach 2009–2012

2014

Wstęp. Ze względu na swoje rozpowszechnienie cukrzyca i jej powikłania stanowią istotny problem zdrowotny, społeczny, a także ekonomiczny. Jako choroba przewleka, postępująca oraz powszechna cukrzyca wymusza odpowiednie i długofalowe rozwiązania ze strony systemu opieki zdrowotnej. Celem pracy jest analiza specjalistycznej opieki diabetologicznej w województwie śląskim w latach 2009–2012. Materiał i metody. Dane dotyczące populacji województwa śląskiego pozyskano z Głównego Urzędu Statystycznego. Surowe dane dotyczące liczby pacjentów, porad oraz ich kosztów — z podziałem na grupy wiekowe oraz poszczególne lata — uzyskano z bazy danych Śląskiego Oddziału Wojewódzkiego Narodowego Funduszu Zd…

Physical-chemical properties and possible applications of clay minerals and humic acid composite materials

2019

Article Pollution caused by pharmaceuticals has become an increasingly serious issue, therefore innovative and cost – effective methods of pharmaceutical’s removal must be studied. Clay – humic acid composite materials can be considered as prospective and low cost sorbents for contaminants. The aim of this study is to develop clay mineral and humic acid composite materials and to characterise their possible applications. For this research, three types of clay minerals (montmorillonite, kaolinite and bentonite) were modified with three types of humic substances: technical humic acid from lignite, humic substances extracted from raised bog peat and technical K humate from lignite. The sorptio…

Biomass Waste Processing into Artificial Humic Substances

2021

Abstract To address the biomass waste processing problem and transform it into refractory forms of carbon, recently suggested hydrothermal carbonization (HTC) of biomass in alkaline environment can be considered as a prospective and climate neutral approach. Biomass HTC provides possibilities to obtain form of biochar (hydrochar) and artificial humic substances, however the conditions of the HTC have not been much studied. Optimization by Response Surface Methodology of the HTC using microwave treatment with three experimental variables (treatment temperature, length of microwave treatment, amount of biomass per volume) provides the possibility to significantly increase the yield of humic s…