Transformation of free-standing ZnO nanorods upon Er doping

2021 ◽  
pp. 150217
Author(s):  
M. Buryi ◽  
Z. Remeš ◽  
V. Babin ◽  
A. Artemenko ◽  
V. Vaněček ◽  
...  
Keyword(s):  
2008 ◽  
Vol 8 (9) ◽  
pp. 4688-4691 ◽  
Author(s):  
Dae-Hee Kim ◽  
Sam-Dong Lee ◽  
Kyoung-Kook Kim ◽  
Gyeong-Su Park ◽  
Ji-Myon Lee ◽  
...  

Large quantity of free-standing ZnO nanorods and nanowalls were synthesized at low temperature of below 100 °C using zinc acetate, zinc nitrate hexahydrate, and hexamethylenetetramine by using a simple aqueous solution method. The general morphology of the grown ZnO nanostructures which include nanorods and nanowalls was strongly influenced by growth conditions. It was found that the grown ZnO nanorods are of a single-crystalline hexagonal structure and preferred c-axis growth orientation. ZnO nanorods were of better crystallinity than ZnO nanowalls, due to the higher growth temperature used to grow ZnO nanorods. Strong free exciton emission bands with relatively weak deep level emission were clearly observed from ZnO nanorods and nanowalls, indicating their good optical properties.


2019 ◽  
Vol 373 ◽  
pp. 179-191 ◽  
Author(s):  
Yizhen Zhang ◽  
Lifen Liu ◽  
Bart Van der Bruggen ◽  
Michael K.H. Leung ◽  
Fenglin Yang

2019 ◽  
Vol 42 (3-4) ◽  
pp. 147-155 ◽  
Author(s):  
M. Hadiyan ◽  
A. Salehi ◽  
A. Koohi-Saadi

Author(s):  
Paulina Hebisz ◽  
Rafal Hebisz ◽  
Marek Zaton

AbstractBackground: The purpose of this study was to compare body balance in road and off-road cyclists, immediately before and after the racing season.Material/Methods: Twenty individuals participated in the study and they were divided into two groups: specialists in road-cycling (n = 10) and in off-road cycling (n = 10). Immediately before and after the five-month racing season stabilographic trials were carried out (at rest and after progressive exercise). In assessing body balance the distance and velocity of the centre shifts (in the anterior-posterior and left-right direction) were analysed. The tests were performed with the cyclists’ eyes open, eyes closed, and in feedback.Results: After the racing season, in the off-road cyclists’ group, distance and velocity of the centre of pressure shifts increased after a progressive exercise.Conclusions: In the off-road cyclists’ group the balance of the body in the sagittal plane deteriorated after the racing season. Moreover, after the racing season off-road cyclists were characterized by a worse balance of the body, compared to road cyclists


2020 ◽  
Author(s):  
Michelina Soccio ◽  
Nadia Lotti ◽  
Andrea Munari ◽  
Esther Rebollar ◽  
Daniel E Martínez-Tong

<p>Nanostructured wrinkles were developed on fully bio-based poly(trimethylene furanoate) (PTF) films by using the technique of Laser Induced Periodic Surface Structures (LIPSS). We investigated the effect of irradiation time on wrinkle formation using an UV pulsed laser source, at a fluence of 8 mJ/cm2. It was found that the pulse range between 600 and 4800 pulses allowed formation of periodic nanometric ripples. The nanostructured surface was studied using a combined macro- and nanoscale approach. We evaluated possible physicochemical changes taking place on the polymer surface after irradiation by infrared spectroscopy, contact angle measurements and atomic force microscopy. The macroscopic physicochemical properties of PTF showed almost no changes after nanostructure formation, differently from the results previously found for the terephthalic counterparts, as poly(ethyleneterephthalate), PET, and poly(trimethyleneterephthalate), PTT. The surface mechanical properties of the nanostructured PTF were found to be improved, as evidenced by nanomechanical force spectroscopy measurements. In particular, an increased Young’s modulus and higher stiffness for the nanostructured sample were measured. <br></p>


2019 ◽  
Author(s):  
Amalia Rapakousiou ◽  
Alejandro López-moreno ◽  
Belén Nieto-Ortega ◽  
M. Mar Bernal ◽  
Miguel A. Monclús ◽  
...  

We introduce poly(1,6-pyrene terephthalamide) polymer (PPyrTA) as an aromatic polyamide analogue of poly(p-phenylene terephthalamide) (PPTA), also known as Kevlar®. This work shows that the incorporation of polycyclic aromatic pyrene moieties improves drastically the mechanical properties of the polymeric structure, increasing elastic nanoindentation-determined modulus and hardness by factors of 1.9 and 4.3, respectively. Liquid deprotonated dispersions of PPyrTA nanofibers were used as nanoscale building block for producing large-surface, free-standing polymer macroscopic nanofilms. This 2D assembly leads to further significant improvements in reduced modulus and hardness (more than twice) compared to the starting polymer macroscale fibres, due to a better re-organizational arrangement of the PPyrTA nanofibers in the nanofilms, formed under 2D spatial confinement.


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