Search results for "OTU"

Halloysite Nanotubes: Smart Nanomaterials in Catalysis

2022

The use of clay minerals as catalyst is renowned since ancient times. Among the different clays used for catalytic purposes, halloysite nanotubes (HNTs) represent valuable resources for industrial applications. This special tubular clay possesses high stability and biocompatibility, resistance against organic solvents, and most importantly be available in large amounts at a low cost. Therefore, HNTs can be efficiently used as catalysts themselves or supports for metal nanoparticles in several catalytic processes. This review reports a comprehensive overview of the relevant advances in the use of halloysite in catalysis, focusing the attention on the last five years.

Orientation of charged clay nanotubes in evaporating droplet meniscus.

2015

© 2014 Elsevier Inc. During drying, an aqueous suspension of strongly charged halloysite clay nanotubes concentrates at the edge of the droplet ("coffee-ring" effect) which provides alignment of the tubes along the liquid-substrate contact line. First, the surface charge of the nanotubes was enhanced by polyanion adsorption inside of the lumen to compensate for the internal positive charges. This increased the magnitude of the ξ-potential of the tubes from -36 to -81mV and stabilized the colloids. Then, colloidal halloysite was dropped onto the substrate, dried at 65°C and after a concentration of ~0.05mgmL-1 was reached, the alignment of nanotubes occurred starting from the droplet edges. …

MODELING OF SPIRAL HALLOYSITE NANOTUBES

2013

Protonation Constants of Halloysite Clay Nanotubes

2015

Halloysite is one of the most interesting nano-structured clay materials. It is similar to kaolin but has a hollow tubular structure that can be attributable to particular crystallization conditions. Typically, halloysite nanotubes (HNTs) are formed by 15 – 20 aluminosilicate layers, has a length of 1 ± 0.5 μm and inner and outer diameters of 1 - 30 and 30 - 50 nm, respectively [1,2]. In each layer the SiOH and the AlOH groups are disposed on the external and the internal surfaces, respectively. The particular structure of HNTs makes this kind of material very useful for different purposes in several fields. Among the various applications, worth of mention are: i) their use as additive for …

Binge administration of 3,4-methylenedioxymethamphetamine ("ecstasy") impairs the survival of neural precursors in adult rat dentate gyrus.

2006

3,4-Methylenedioxymethamphetamine (MDMA) is a potent stimulant and hallucinogenic drug whose ability to regulate neurogenesis in the adult has not been previously investigated. We used 5'-bromo-2-deoxyuridine (BrdU) and Ki-67 as mitotic markers, and doublecortin (DCX) as a marker of immature neurons, to study proliferation, survival and maturation of adult-generated cells in the dentate gyrus (DG) of the hippocampus following binge administration of MDMA (8 injections of 5 mg/kg at 6 h intervals). The results showed that MDMA treatment did not affect cytogenesis in the DG, but significantly decreased the survival rate of cells incorporated after 2 weeks to the granular layer of the DG by ca…

Status indicators in software engineering group projects

2023

A segment of studies on group structure and performance in software engineering (SE) project-based learning (PjBL) have focused on roles, including studies that use Belbin team roles and studies that address problematic roles such as social loafing. The present study focuses on the status, which is basically missing in SE PjBL studies, although relating to roles. The study investigates the aspects that students identified as indicators of rising or declining status in their project groups. The status theory was utilized as the framework that motivated the research and on which the results were reflected. An inductive qualitative content analysis was applied to learning reports in which stud…

Sea urchin coelomocytes as a novel cellular biosensor of environmental stress: a field study in the Tremiti Island Marine Protected Area, Southern Ad…

2007

The aim of the present study was to investigate on the suitability of the sea urchin as a sentinel organism for the assessment of the macro-zoobenthos health state in bio-monitoring programmes. A field study was carried out during two oceanographic campaigns using immuno-competent cells, the coelomocytes, from sea urchins living in a marine protected area. In particular, coelomocytes subpopulations ratio and heat shock protein 70 (HSC70) levels were measured in specimens of Paracentrotus lividus (Lamark, 1816) collected in two sampling sites, namely Pianosa and Caprara Islands, both belonging to the Tremiti Island Marine Protected Area (MPA) in the Southern Adriatic Sea, Italy. By density g…

"Hyvien perheiden pojat murhasivat kylmästi - Miksi?" : syylliset ja syyttömät Heinojen surmaa seuranneen moraalisen myrskyn pyörteissä kolmessa sano…

2004

New record of Actinonotus pulcher (Herrich-Schaeffer, 1835) (Hemiptera: Heteroptera: Miridae) in Poland

2016

A new record of Actinonotus pulcher (Herrich-Schaeffer, 1835) from Poland is reported. Male genitalia drawings of Actinonotus pulcher are also provided.

Perdere il senno e darsi la morte. Due casi singolari di punizione divina nelle Storie di Erodoto (V 85; VI, 75)

2016

Scopo di questo paper è l’analisi dei temi della follia e del suicidio nella struttura narrativa di Erodoto. I due episodi esaminati sono: a) il racconto della pazzia che colpì gli Ateniesi, che avevano tentato invano di sottrarre agli Egineti le sacre statue di Damia e Auxesia; b) la storia dei disaccordi tra i due re spartani Demarato e Cleomene e il loro tragico esito. Questi due episodi sono profondamente interconnessi: attraverso i rimandi interni, suggeriti dalle scelte linguistiche dello storico, noi vogliamo infine riflettere sul modello causale erodoteo. The aim of this paper is the analysis of the themes of madness and suicide in the narrative structure of Herodotus. Two episodes …