Proton NMR relaxometry as a useful tool to evaluate swelling processes in peat soils

Dramatic physical and physico-chemical changes in soil properties may arise due to temperature and moisture variations as well as swelling of soil organic matter (SOM) under constant conditions. Soil property variations may influence sorption/desorption and transport processes of environmental contaminants and nutrients in natural-organic-matterrich soils. Notwithstanding the studies reported in literature, a mechanistic model for SOM swelling is unavailable yet. The objective of the present study was the evaluation of the swelling of peat soils, considered as SOM models, by 1H NMR relaxometry and differential scanning calorimetry (DSC). Namely, information on the processes governing physical and physicochemical changes of peat during re-hydration were collected. The basic hypothesis of the present study was that the changes are slow and may affect water state as well as amounts of different water types into the peats. For this reason, such changes can be evidenced through the variations of mobility and thermal behaviour of the involved H2O molecules by using 1H NMR relaxometry and DSC. According to the experimental results, a mechanistic model, describing the fundamental processes of peat swelling, was obtained. Two different peats re-wetted at three temperatures were used. The swelling process was monitored by measuring spin-spin relaxation time (T2) over a hydration time of several months. Moreover, DSC, T1 – T2 and T2 – D correlation measurements were done at the beginning and at the end of the hydration. Supplementary investigations were also done in order to discriminate between the swelling effects and the contributions from soil solution, internal magnetic field gradients and/or soil microorganisms to proton relaxation. All the results revealed peat swelling. It was evidenced by pore size distribution changes, volumetric expansion and redistribution of water, increasing amounts of nonfreezable and loosely bound water, as well as formation of gel phases and reduction of the translational and rotational mobility of H2O molecules. All the findings implied that changes of the physical and physicochemical properties of peats were obtained. In particular, three different processes having activation energies comprised in the interval 5 – 50 kJ mol-1 were revealed. The mechanistic model which was, then, developed included water reorientation in bound water phases, water diffusion into the peat matrix and reorientation of SOM chains as fundamental processes governing SOM swelling. This study is of environmental significance in terms of re-naturation and re-watering of commercially applied peatlands and of sorption/desorption and transport processes of pollutants and nutrients in natural organic matter rich soil

Hexakis(dimethylformamide)bis(hexaphenylcyclohexasiloxanehexaolato)hexacopper(II) Dimethylformamide Solvate

The sandwich-like title complex, hexakis(dimethylformamide)-1O,2O,3O,4O,5O,6O-bis[2,4,6,8,10,12-hexaphenylsiloxane-2,4,6,8,10,12-hexaolato(6-)-1:22O1,2:32O2,3:42O3,- 4:52O4,5:62O5,1:62O6]hexacopper(II) tetrakis(dimethylformamide) solvate, [Cu6(C3H7NO)6{(C6H5)6O12Si6}2].4C3H7NO, is comprised of two regular crown-shaped macrocyclic hexadentate organosiloxanolate ligands chelating a flat Cu6 hexagon, as in the ethanol-solvated analogue investigated previously. The title complex has a more distorted shape than the trigonal ethanol-solvated analogue, being slightly side-oblated, but still contains a large empty inner channel accessible by small molecules (the diameter of the free cross-section being about 2.5 Å). Each CuII ion has square-pyramidal coordination with four basal siloxanolate O atoms and an apical dimethylformamide (DMFA) molecule (coordinated through its carbonyl group). The average bond lengths are: Cu-O(Si) 1.964 (11) Å and Cu-O(DMFA) 2.215 (10) Å. The structure contains four additional DMFA molecules per complex unit, linked by weak C-HO hydrogen bonds. Unexpectedly, the C=O bond length is longer [1.248 (10) and 1.255 (9) Å] in the uncoordinated DMFA molecules than in the coordinated [1.214-1.227 (7) Å]

Features of the Concept FAMILIE Represented in the Biographical Discourse of Russian Germans

This paper describes a study conducted within the framework of modern German studies in accordance with the anthropocentric orientation of scientific paradigm. The study investigates the concept FAMILIE in the linguistic image of the world of Russian Germans living in Siberia. The contextual analysis of biographical stories of the representatives of the German ethnic community has helped us discover that the concept FAMILIE enters into complex hierarchical relationships with related concepts. Building a taxonomic model of this concept revealed its base, super- and subordinate levels and their linguistic realization

Creating an Interactive Module for the Promotion of the Specialty “Document Management”

В исследовании рассматриваются некоторые теоретические и практические вопросы документоведения — актуальной науки о носителях информации. Особое внимание уделено особенностям подготовки современных специалистов-документоведов, проанализирована информация о возможностях их трудоустройства и уже состоявшихся карьерах. Авторы обнаруживают необходимость создания интерактивных условий, повышающих престижность образовательной программы в области документоведения в период работы приемной комиссии и набора абитуриентов на эту специальность.The article deals with some theoretical and practical issues of document management’s popularization as a specialty of higher education. Special attention is paid to the peculiarities of modern documentary specialists’ training, analyzed information about the possibilities of their employment. The authors argue that it is necessary to create an interactive environment that increases the prestige of the educational program in the field of documentation during the work of the admission committee and the recruitment of students for this specialty

Benetzungseigenschaften als Funktion des Kationenbelags

Mit H+, Na+, Ca2+ und Al3+ belegte, mit H2O ausgewaschene und anschliessend fraktionierte (<2000µm, 2000-63µm, <63µm) Proben eines sandigen Gleypodsols wurden auf ihre Benetzungs-eigenschaften (bestimmt als Kontakt-winkel CA) untersucht. Der CA variierte (unsystematisch) als Funktion der Zeit (Auswertung der CA nach 33ms, 1000ms, 5000ms) mit der Art der Belegung

Military Component of American Historical Memory: “the Justice” of the Vietnam War

Historical memory can be divided into three main levels: collective (national), mass and individual. The ratio between them can be different: the same, overlap or contradicting each other. So when forming the collective historical memory should be made of the three main factors: political order, their own interests’ agents, the desire not to offend or not to initiate an active disagreement from those who have personal experience that has formed an opinion on this period, or event. Memory is expressed in signs and symbols, affecting both the mind and the subconscious mind; it constantly recharges sense of national identity, loyalty lifestyle and righteous actions. The history of society during war clearly identifies basic principles of nature as an individual and society as a whole. The military component is one of the most accurate tests of justice and legality, correctness of life as individuals, social groups and the whole society. Therefore, the study of the formation of national memory, using military experience, allows high accuracy to determine the major features of mentality. For the history of formation of the memory of the American society, exactly the Vietnam War can be called the most striking example of the use of memory about it to prove its creditability