DISSIPATION TEST EVALUATION WITH A POINT-SYMMETRICAL CONSOLIDATION MODEL

A point-symmetrical linear coupled consolidation model with constant displacement boundary condition is tested against measured dissipation test data. Results show that - similarly to the previously tested cylindrical model - very short data jets can successfully be evaluated if the sensor is well above the tip

Quantifying Particle Breakage and Its Evolution Using Breakage Indices and Grading Entropy Coordinates

Particle breakage in soils is a well-recognised behaviour. Conventional methods for quantifying the breakage process rely on calculating the area between the particle size distribution (PSD) curves produced before and after crushing. A key aspect of breakage is understanding the process across the different size/sieve fractions. Grading entropy coordinates allow for the representation of any PSD to be shown as a single point on a Cartesian plane and are able to track grading evolution with relative ease. In this study, grading entropy coordinates are compared to three commonly used breakage indices (Br, Br* and IG). It is shown that grading entropy coordinates are advantageous over the traditional indices in quantifying subtle changes in the PSD evolution and directly provide further insight with regards to the individual fraction sizes. It is also discussed that conventional breakage indices rely on relative measures and are dependent on assumptions of an initial and/or final PSD. In contrast, grading entropy coordinates depend only on the characteristics of the (current) PSD curve. It was also observed that the breakage evolution captured by the entropy coordinates is able to determine the rate at which differently sized particles break as differently sized particles take on stress. Moreover, it is suggested that entropy coordinates may also stress path dependency, a feature not present in conventional indices

Integrated stratigraphy of the Gusterita clay pit: a key section for the early Pannonian (late Miocene) of the Transylvanian Basin (Romania)

The Neogene Transylvanian Basin (TB), enclosed between the eastern and southern Carpathians and the Apuseni Mountains in Romania, is a significant natural gas province with a long production history. In order to improve the (bio) stratigraphic resolution, correlations and dating in the several 100-m-thick upper Miocene (Pannonian) succession of the basin, the largest and most fossiliferous outcrop at Gusterita (northeastern part of Sibiu) was investigated and set as a reference section for the Congeria banatica zone in the entire TB. Grey, laminated and massive silty marl, deposited in the deep-water environment of Lake Pannon, was exposed in the similar to 55-m-high outcrop. The uppermost 25 m of the section was sampled in high resolution (sampling per metres) for macro- and microfossils, including palynology; for authigenic Be-10/Be-9 dating and for magnetostratigraphy; in addition, macrofossils and samples for authigenic Be-10/Be-9 isotopic measurements were collected from the lower part of the section as well. The studied sedimentary record belongs to the profundal C banatica mollusc assemblage zone. The upper 25 m can be correlated to the Hemicytheria tenuistriata and Propontoniella candeo ostracod biozones, the uppermost part of the Spiniferites oblongus, the entire Pontiadinium pecsvaradense and the lowermost part of the Spiniferites hennersdorfensis organic-walled microplankton zones. All samples contained endemic Pannonian calcareous nannofossils, representing the Noelaerhabdus bozinovicae zone. Nine samples were analysed for authigenic Be-10/Be-9 isotopic measurements. The calculated age data of six samples provided a weighted mean value of 10.42 +/- 0.39 Ma. However, three samples within the section exhibited higher isotopic ratios and yielded younger apparent ages. A nearly twofold change in the initial Be-10/Be-9 ratio is a possible reason for the higher measured isotopic ratios of these samples. Magnetostratigraphic samples showed normal polarity for the entire upper part of the outcrop and can be correlated with the C5n.2n polarity chron (11.056-9.984 Ma, ATNTS2012), which is in agreement with the biostratigraphic data. Based on these newly obtained data and correlation of the biozones with other parts of the Pannonian Basin System, the Guterita section represents the similar to 11.0-10.5 Ma interval, and it is a key section for correlation of mollusc, ostracod, dinoflagellate and calcareous nannoplankton biostratigraphic records within this time interval

Béta-amiloid peptidek aggregációja és kölcsönhatása fehérjékkel; új neuroprotektív vegyületek alkalmazása az Alzheimer-kór megelőzésére = Beta-amyloid aggregation and interaction with proteins; novel neuroprotective compounds for prevention of Alzheimer's disease

Új, standardizálható módszert dolgoztunk ki toxikus �béta-amiloid (Abéta) 1-42 peptid oligomerek előállítására, a preparált oligomereket fiziko-kémiai módszerekkel jellemeztük. Két új neuroprotektív peptidmimetikum vegyületcsaládot találtunk, ezek az anyagok megvédik a neuronokat az Alzheimer-kór (AK) állatmodelljében az Abéta neurotoxikus hatásától. Mindkét vegyületcsoportot szabadalmilag védjük, mint az AK potenciális gyógyszerjelölt vegyületeit. Új ex vivo módszert dolgoztunk ki az Abéta peptidek toxicitásának mérésére (patkány hippocampus szelet, MTT-teszt), a módszer alkalmas az új neuroprotektív vegyületeink aktivitásmérésére is. Az ex vivo hippocampus szeleteket sikerrel alkalmaztuk a neuronális plaszticitás (LTP) mérésére, az Abéta-toxicitás meghatározására, multielektród array (MEA) technikával. In vivo, egysejt-elvezetéses elektrofiziológiai mérésekkel bizonyítottuk az új peptidmimetikumaink neuroprotektív hatását. Proteomikai módszerekkel azonosítottuk az Abéta peptidekkel kölcsönhatásba lépő fehérjéket, ezek elsősorban plazmamembrán, ill. intraneuronális fehérjék (mitokondrium, endoplazmás reticulum, mikrotubuláris rendszer). Az intraneuronális fehérjék és az Abéta peptidek kölcsönhatásai kulcsszerepet játszhatnak az AK patogenezisében. Igazoltuk, hogy a Zn2+ ionok toxikus Abéta-aggregátumok képződését indukálják. Az AK transzgén állatmodelljén bizonyítottuk, hogy a Zn-kelátorok (pl. Perindopril) neuroprotektív hatásúak. Új AK-állatmodellt dolgoztunk ki az Abéta oligomerek icv bevitelével. | A new method was introduced for the preparation of toxic beta-amyloid (Abeta) 1-42 oligomers, these assemblies were characterized with physicochemical methods. Two families of novel neuroprotective peptidomimetics were found, these substances protect neurons against the toxic effect of Abeta in tg mouse models of Alzheimer’s disease (AD). Both groups of the novel substances will be patented as putative drug candidates for AD treatment. A new ex vivo method was introduced for toxicity measurement of Abeta peptides (rat hippocampal slices, MTT-assay); this method proved to be suitable for activity measurement of the novel neuroprotective substances. Hippocampal slices were successfully used for measurement of neuronal plasticity (LTP) for demonstrating neurotoxicity of Abeta aggregates, applying multielectrode array (MEA) technique. The neuroprotective effect of our novel peptidomimetics was demonstrated also in vivo, using one-cell electrophysiology. Proteomic methods were used for identification of proteins interacting with Abeta peptides; these are mainly plasma membrane and intraneuronal (mitochondrial, endoplasmatic reticular and microtubular) proteins. Interaction of intracellular proteins with Abeta may play key role in AD pathogenesis. The role of Zn2+ ions in formation of toxic Abeta-aggregates was demonstrated. Zn2+-chelators (e.g. Perindopril) were neuroprotective in a tg-mouse model of AD. A new AD rat model was introduced using icv administration of synthetic Abeta oligomers

The significance of relative density for particle damage in loaded and sheared gravels

For granular assemblages of strong particles, an increase in the relative density usually leads to a significant increase in shear strength, which is evident as a peak strength, accompanied by significant dilation as the peak strength is attained. This paper describes an experimental study of shearing in assemblages of weak particles, where particle breakage offsets dilation for all but the lowest of confining stresses. In such materials, prone to particle breakage, the shear strengths of loose and dense assemblages rapidly converge to similar values as confining stress increases, and any benefit of greater relative density is lost. This is attributed to the densification effect associated with the loading under a high stress prior to shearing, which is characterised by widespread particle breakage and the formation of smaller particles to occupy space between coarser ones. Interestingly, under both low and high stresses, there was a tendency for greater particle breakage in the loose samples, as a result of both shearing and compression. This result suggests that, despite the denser assemblage having its particles more rigidly constrained and less able to rearrange to avoid direct loading, the influence of greater load-spreading capacity afforded by an increased number of particle contacts in a denser sample, is more dominant in controlling breakage